Rapid generation of recombinant Pseudomonas putida secondary metabolite producers using yTREX.

PubMed

Domröse, Andreas; Weihmann, Robin; Thies, Stephan; Jaeger, Karl-Erich; Drepper, Thomas; Loeschcke, Anita

2017-12-01

Microbial secondary metabolites represent a rich source of valuable compounds with a variety of applications in medicine or agriculture. Effective exploitation of this wealth of chemicals requires the functional expression of the respective biosynthetic genes in amenable heterologous hosts. We have previously established the TREX system which facilitates the transfer, integration and expression of biosynthetic gene clusters in various bacterial hosts. Here, we describe the yTREX system, a new tool adapted for one-step yeast recombinational cloning of gene clusters. We show that with yTREX, Pseudomonas putida secondary metabolite production strains can rapidly be constructed by random targeting of chromosomal promoters by Tn5 transposition. Feasibility of this approach was corroborated by prodigiosin production after yTREX cloning, transfer and expression of the respective biosynthesis genes from Serratia marcescens . Furthermore, the applicability of the system for effective pathway rerouting by gene cluster adaptation was demonstrated using the violacein biosynthesis gene cluster from Chromobacterium violaceum , producing pathway metabolites violacein, deoxyviolacein, prodeoxyviolacein, and deoxychromoviridans. Clones producing both prodigiosin and violaceins could be readily identified among clones obtained after random chromosomal integration by their strong color-phenotype. Finally, the addition of a promoter-less reporter gene enabled facile detection also of phenazine-producing clones after transfer of the respective phenazine-1-carboxylic acid biosynthesis genes from Pseudomonas aeruginosa . All compounds accumulated to substantial titers in the mg range. We thus corroborate here the suitability of P. putida for the biosynthesis of diverse natural products, and demonstrate that the yTREX system effectively enables the rapid generation of secondary metabolite producing bacteria by activation of heterologous gene clusters, applicable for natural compound discovery and combinatorial biosynthesis.

Labdane-type diterpenoids from hairy root cultures of Coleus forskohlii, possible intermediates in the biosynthesis of forskolin.

PubMed

Asada, Yoshihisa; Li, Wei; Terada, Tomohiro; Kuang, Xinzhu; Li, Qin; Yoshikawa, Takafumi; Hamaguchi, Shogo; Namekata, Iyuki; Tanaka, Hikaru; Koike, Kazuo

2012-07-01

Significant attention has been devoted to studying hairy root cultures as a promising strategy for production of various valuable secondary metabolites. These offer many advantages, such as high growth rate, genetic stability and being hormone-free. In this study, a detailed phytochemical investigation of the secondary metabolites of Coleus forskohlii hairy root cultures was undertaken and which resulted in the isolation of 22 compounds, including four forskolin derivatives and a monoterpene. Their structures were elucidated by extensive spectroscopic analyses. These compounds could be classified into four groups viz.: labdane-type diterpenes, monoterpenes, triterpenes and phenylpropanoid dimers. Apart from one compound, all labdane type diterpenes are oxygenated at C-11 as in forskolin and a scheme showing their biosynthetic relationships is proposed. Copyright © 2012 Elsevier Ltd. All rights reserved.

Microalgae for high-value compounds and biofuels production: a review with focus on cultivation under stress conditions.

PubMed

Markou, Giorgos; Nerantzis, Elias

2013-12-01

Microalgal biomass as feedstock for biofuel production is an attracting alternative to terrestrial plant utilization for biofuels production. However, today the microalgal cultivation systems for energy production purposes seem not yet to be economically feasible. Microalgae, though cultivated under stress conditions, such as nutrient starvation, high salinity, high temperature etc. accumulate considerable amounts (up to 60-65% of dry weight) of lipids or carbohydrates along with several secondary metabolites. Especially some of the latter are valuable compounds with an enormous range of industrial applications. The simultaneous production of lipids or carbohydrates for biofuel production and of secondary metabolites in a biorefinery concept might allow the microalgal production to be economically feasible. This paper aims to provide a review on the available literature about the cultivation of microalgae for the accumulation of high-value compounds along with lipids or carbohydrates focusing on stress cultivation conditions. © 2013.

Genome-guided Investigation of Antibiotic Substances produced by Allosalinactinospora lopnorensis CA15-2T from Lop Nor region, China

PubMed Central

Huang, Chen; Leung, Ross Ka-Kit; Guo, Min; Tuo, Li; Guo, Lin; Yew, Wing Wai; Lou, Inchio; Lee, Simon Ming Yuen; Sun, Chenghang

2016-01-01

Microbial secondary metabolites are valuable resources for novel drug discovery. In particular, actinomycetes expressed a range of antibiotics against a spectrum of bacteria. In genus level, strain Allosalinactinospora lopnorensis CA15-2T is the first new actinomycete isolated from the Lop Nor region, China. Antimicrobial assays revealed that the strain could inhibit the growth of certain types of bacteria, including Acinetobacter baumannii and Staphylococcus aureus, highlighting its clinical significance. Here we report the 5,894,259 base pairs genome of the strain, containing 5,662 predicted genes, and 832 of them cannot be detected by sequence similarity-based methods, suggesting the new species may carry a novel gene pool. Furthermore, our genome-mining investigation reveals that A. lopnorensis CA15-2T contains 17 gene clusters coding for known or novel secondary metabolites. Meanwhile, at least six secondary metabolites were disclosed from ethyl acetate (EA) extract of the fermentation broth of the strain by high-resolution UPLC-MS. Compared with reported clusters of other species, many new genes were found in clusters, and the physical chromosomal location and order of genes in the clusters are distinct. This study presents evidence in support of A. lopnorensis CA15-2T as a potent natural products source for drug discovery. PMID:26864220

Plant cell cultures: bioreactors for industrial production.

PubMed

Ruffoni, Barbara; Pistelli, Laura; Bertoli, Alessandra; Pistelli, Luisa

2010-01-01

The recent biotechnology boom has triggered increased interest in plant cell cultures, since a number of firms and academic institutions investigated intensively to rise the production of very promising bioactive compounds. In alternative to wild collection or plant cultivation, the production of useful and valuable secondary metabolites in large bioreactors is an attractive proposal; it should contribute significantly to future attempts to preserve global biodiversity and alleviate associated ecological problems. The advantages of such processes include the controlled production according to demand and a reduced man work requirement. Plant cells have been grown in different shape bioreactors, however, there are a variety of problems to be solved before this technology can be adopted on a wide scale for the production of useful plant secondary metabolites. There are different factors affecting the culture growth and secondary metabolite production in bioreactors: the gaseous atmosphere, oxygen supply and CO2 exchange, pH, minerals, carbohydrates, growth regulators, the liquid medium rheology and cell density. Moreover agitation systems and sterilization conditions may negatively influence the whole process. Many types ofbioreactors have been successfully used for cultivating transformed root cultures, depending on both different aeration system and nutrient supply. Several examples of medicinal and aromatic plant cultures were here summarized for the scale up cultivation in bioreactors.

Addressing Challenges to Enhance the Bioactives of Withania somnifera through Organ, Tissue, and Cell Culture Based Approaches

PubMed Central

Singh, Pritika; Guleri, Rupam; Angurala, Amrita; Kaur, Kuldeep; Kaur, Kulwinder; Kaul, Sunil C.; Wadhwa, Renu

2017-01-01

Withania somnifera is a highly valued medicinal plant in traditional home medicine and is known for a wide range of bioactivities. Its commercial cultivation is adversely affected by poor seed viability and germination. Infestation by various pests and pathogens, survival under unfavourable environmental conditions, narrow genetic base, and meager information regarding biosynthesis of secondary metabolites are some of the other existing challenges in the crop. Biotechnological interventions through organ, tissue, and cell culture provide promising options for addressing some of these issues. In vitro propagation facilitates conservation and sustainable utilization of the existing germplasms and broadening the genetic base. It would also provide means for efficient and rapid mass propagation of elite chemotypes and generating uniform plant material round the year for experimentation and industrial applications. The potential of in vitro cell/organ cultures for the production of therapeutically valuable compounds and their large-scale production in bioreactors has received significant attention in recent years. In vitro culture system further provides distinct advantage for studying various cellular and molecular processes leading to secondary metabolite accumulation and their regulation. Engineering plants through genetic transformation and development of hairy root culture system are powerful strategies for modulation of secondary metabolites. The present review highlights the developments and sketches current scenario in this field. PMID:28299323

Uncovering the repertoire of fungal secondary metabolites: From Fleming's laboratory to the International Space Station.

PubMed

Boruta, Tomasz

2018-01-01

Fungi produce a variety of secondary metabolites (SMs), low-molecular weight compounds associated with many potentially useful biologic activities. The examples of biotechnologically relevant fungal metabolites include penicillin, a β-lactam antibiotic, and lovastatin, a cholesterol-lowering drug. The discovery of pharmaceutical lead compounds within the microbial metabolic pools relies on the selection and biochemical characterization of promising strains. Not all SMs are produced under standard cultivation conditions, hence the uncovering of chemical potential of investigated strains often requires the use of induction strategies to awake the associated biosynthetic genes. Triggering the secondary metabolic pathways can be achieved through the variation of cultivation conditions and growth media composition. The alternative strategy is to use genetic engineering to activate the respective genomic segments, e.g. by the manipulation of regulators or chromatin-modifying enzymes. Recently, whole-genome sequencing of several fungi isolated from the Chernobyl accident area was reported by Singh et al. (Genome Announc 2017; 5:e01602-16). These strains were selected for exposure to microgravity at the International Space Station. Biochemical characterization of fungi cultivated under extreme conditions is likely to provide valuable insights into the adaptation mechanism associated with metabolism and, possibly, a catalog of novel molecules of potential pharmaceutical importance.

Metabolic Engineering of the Shikimate Pathway for Production of Aromatics and Derived Compounds—Present and Future Strain Construction Strategies

PubMed Central

Averesch, Nils J. H.; Krömer, Jens O.

2018-01-01

The aromatic nature of shikimate pathway intermediates gives rise to a wealth of potential bio-replacements for commonly fossil fuel-derived aromatics, as well as naturally produced secondary metabolites. Through metabolic engineering, the abundance of certain intermediates may be increased, while draining flux from other branches off the pathway. Often targets for genetic engineering lie beyond the shikimate pathway, altering flux deep in central metabolism. This has been extensively used to develop microbial production systems for a variety of compounds valuable in chemical industry, including aromatic and non-aromatic acids like muconic acid, para-hydroxybenzoic acid, and para-coumaric acid, as well as aminobenzoic acids and aromatic α-amino acids. Further, many natural products and secondary metabolites that are valuable in food- and pharma-industry are formed outgoing from shikimate pathway intermediates. (Re)construction of such routes has been shown by de novo production of resveratrol, reticuline, opioids, and vanillin. In this review, strain construction strategies are compared across organisms and put into perspective with requirements by industry for commercial viability. Focus is put on enhancing flux to and through shikimate pathway, and engineering strategies are assessed in order to provide a guideline for future optimizations. PMID:29632862

Influence of organic supplements on production of shoot and callus biomass and accumulation of bacoside in Bacopa monniera (L.) Pennell.

PubMed

Parale, Anuradha; Barmukh, Rajkumar; Nikam, Tukaram

2010-04-01

Production of valuable secondary metabolites through plant cell or organ culture is the best suited alternative to extraction of whole plant material and to increase production of secondary metabolites in in-vitro systems, feeding precursor or intermediate metabolites is an obvious and popular approach. The present investigation was aimed to study the influence of feeding of organic supplements, glycine (0-125 μM), ferulic acid (0-200 μM), phenylalanine (0-200 μM), α-ketoglutaric acid (0-200 μM) and pyruvic acid (0-200 μM) on production of bacoside-A (a triterpenoid type secondary metabolite responsible for cognition effects) in shoot and callus biomass of Bacopa monniera (L.) Pennell. The shoots were raised in liquid Murashige and Skoog's (MS) medium fortified with 5 μM 6-benzyladenine (BA) and callus biomass on agar solidified MS medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4 -D) in conjunction with 5 μM 1-napthaleneacetic acid (NAA). Among the organic supplements used, 100 μM pyruvic acid effectively enhanced the production of bacoside-A in shoot as well as callus biomass. The bacoside-A content in in-vitro raised shoot biomass was 4.0 and 1.2 times higher as compared to control and shoot biomass of naturally grown plants respectively. Inclusion of pyruvic acid in MS medium for in-vitro shoot cultures of B. monniera, can be adapted for enhanced production of bacoside-A.

Sodium dithionite-enhanced quality of radix scutellariae through modification of secondary metabolism

PubMed Central

Huimin, Guo; Xiaoying, Fu; Hongwei, Du; Wei, Cong; Xiangcai, Meng

2016-01-01

Introduction: The quality of radix scutellariae is particularly associated with environmental stresses, but detailed mechanisms remained unclear. Plant under unfavorable situation generates redundant reactive oxygen species (ROS), and ROS can modify the secondary metabolism. The varied quality of radix scutellariae could be explained by ROS. Materials and Methods: .004, 0.4, and 40 μmol/L of sodium dithionite (Na2S2O4), a material producing ROS, were applied to Scutellaria baicalensis to mimic unfavorable situation. The relationship between ROS, antioxidant enzymes activity, and secondary metabolite was investigated. Results: ROS level fails to rise due to both the antioxidase and the secondary metabolites. The activities of both superoxide dismutase and catalase in the roots of S. baicalensis showed a moderately improvement, meanwhile the phenylalanine ammonia lyase was strongly expressed, and the biosynthesis of flavonoids was heavily elevated. Although the glycosides such as baicalin and wogonoside changed little, the aglycones with the highest effective, such as baicalein and wogonin, were increased by approximately 50%-100%. Conclusion: This is very valuable in insight into the stress physiology and provides a strong tool to enhance the quality of radix scutellariae. PMID:28123992

Steps towards the synthetic biology of polyketide biosynthesis.

PubMed

Cummings, Matthew; Breitling, Rainer; Takano, Eriko

2014-02-01

Nature is providing a bountiful pool of valuable secondary metabolites, many of which possess therapeutic properties. However, the discovery of new bioactive secondary metabolites is slowing down, at a time when the rise of multidrug-resistant pathogens and the realization of acute and long-term side effects of widely used drugs lead to an urgent need for new therapeutic agents. Approaches such as synthetic biology are promising to deliver a much-needed boost to secondary metabolite drug development through plug-and-play optimized hosts and refactoring novel or cryptic bacterial gene clusters. Here, we discuss this prospect focusing on one comprehensively studied class of clinically relevant bioactive molecules, the polyketides. Extensive efforts towards optimization and derivatization of compounds via combinatorial biosynthesis and classical engineering have elucidated the modularity, flexibility and promiscuity of polyketide biosynthetic enzymes. Hence, a synthetic biology approach can build upon a solid basis of guidelines and principles, while providing a new perspective towards the discovery and generation of novel and new-to-nature compounds. We discuss the lessons learned from the classical engineering of polyketide synthases and indicate their importance when attempting to engineer biosynthetic pathways using synthetic biology approaches for the introduction of novelty and overexpression of products in a controllable manner. © 2013 The Authors FEMS Microbiology Letters published by John Wiley & Sons Ltd on behalf of Federation of European Microbiological Societies.

Fungal Resistance to Plant Antibiotics as a Mechanism of Pathogenesis

PubMed Central

Morrissey, John P.; Osbourn, Anne E.

1999-01-01

Many plants produce low-molecular-weight compounds which inhibit the growth of phytopathogenic fungi in vitro. These compounds may be preformed inhibitors that are present constitutively in healthy plants (also known as phytoanticipins), or they may be synthesized in response to pathogen attack (phytoalexins). Successful pathogens must be able to circumvent or overcome these antifungal defenses, and this review focuses on the significance of fungal resistance to plant antibiotics as a mechanism of pathogenesis. There is increasing evidence that resistance of fungal pathogens to plant antibiotics can be important for pathogenicity, at least for some fungus-plant interactions. This evidence has emerged largely from studies of fungal degradative enzymes and also from experiments in which plants with altered levels of antifungal secondary metabolites were generated. Whereas the emphasis to date has been on degradative mechanisms of resistance of phytopathogenic fungi to antifungal secondary metabolites, in the future we are likely to see a rapid expansion in our knowledge of alternative mechanisms of resistance. These may include membrane efflux systems of the kind associated with multidrug resistance and innate resistance due to insensitivity of the target site. The manipulation of plant biosynthetic pathways to give altered antibiotic profiles will also be valuable in telling us more about the significance of antifungal secondary metabolites for plant defense and clearly has great potential for enhancing disease resistance for commercial purposes. PMID:10477313

FMM: a web server for metabolic pathway reconstruction and comparative analysis.

PubMed

Chou, Chih-Hung; Chang, Wen-Chi; Chiu, Chih-Min; Huang, Chih-Chang; Huang, Hsien-Da

2009-07-01

Synthetic Biology, a multidisciplinary field, is growing rapidly. Improving the understanding of biological systems through mimicry and producing bio-orthogonal systems with new functions are two complementary pursuits in this field. A web server called FMM (From Metabolite to Metabolite) was developed for this purpose. FMM can reconstruct metabolic pathways form one metabolite to another metabolite among different species, based mainly on the Kyoto Encyclopedia of Genes and Genomes (KEGG) database and other integrated biological databases. Novel presentation for connecting different KEGG maps is newly provided. Both local and global graphical views of the metabolic pathways are designed. FMM has many applications in Synthetic Biology and Metabolic Engineering. For example, the reconstruction of metabolic pathways to produce valuable metabolites or secondary metabolites in bacteria or yeast is a promising strategy for drug production. FMM provides a highly effective way to elucidate the genes from which species should be cloned into those microorganisms based on FMM pathway comparative analysis. Consequently, FMM is an effective tool for applications in synthetic biology to produce both drugs and biofuels. This novel and innovative resource is now freely available at http://FMM.mbc.nctu.edu.tw/.

Activities of Tannins--From In Vitro Studies to Clinical Trials.

PubMed

Sieniawska, Elwira

2015-11-01

Tannins are considered as valuable plant secondary metabolites providing many benefits for human health. In this review information was gathered about bioactivity in vitro and in vivo, as well as about conducted clinical trials. The literature research was based on ScienceDirect, Scopus, and Cochrane databases and presents a wide range of tested activities of tannins. The described clinical trials verify laboratory tests and show the effective health benefits taken from supplementation with tannins.

Methyl jasmonate mediates upregulation of bacoside A production in shoot cultures of Bacopa monnieri.

PubMed

Sharma, Poojadevi; Yadav, Sheetal; Srivastava, Anshu; Shrivastava, Neeta

2013-07-01

Methyl jasmonate (MJ) enhances the production of a range of secondary metabolites including triterpenoid saponins in a variety of plant species. Here, it enhanced production of bacoside A, a valuable triterpenoid saponin having nootropic therapeutic activity in in vitro shoot cultures of Bacopa monnieri, the only known source of bacoside A. The highest yield was with 50 μM MJ giving 4.4 mg bacoside A/g dry wt; an 1.8-fold increase (compared to control) after 1 week.

[Molecular regulation of microbial secondary metabolites--a review].

PubMed

Wang, Linqi; Tan, Huarong

2009-04-01

Microbial secondary metabolites play an important role in the field of industry, agriculture, medicine and human health. The molecular regulation of secondary metabolites is gradually becoming noticeable and intriguing. In recent years, many researches have demonstrated that secondary metabolite biosynthesis is tightly linked to the physiological and developmental status in its producer. It is suggested that the biosynthesis of secondary metabolites involves in complex process concerning multi-level regulation. Here we reviewed the recent research progress on the molecular regulation of secondary metabolites in microorganisms. In known about ten thousand kinds of natural secondary metabolites, most of them (about 60%) were produced by Streptomycete. Therefore, the regulation of secondary metabolites in Streptomyces is chosen as the mainline in this review. Additionally, several well-studied antibiotics as the representative members were targeted. Finally, some suggestions, in response to the issues at present, have been presented in this paper.

Comprehensive annotation of secondary metabolite biosynthetic genes and gene clusters of Aspergillus nidulans, A. fumigatus, A. niger and A. oryzae

PubMed Central

2013-01-01

Background Secondary metabolite production, a hallmark of filamentous fungi, is an expanding area of research for the Aspergilli. These compounds are potent chemicals, ranging from deadly toxins to therapeutic antibiotics to potential anti-cancer drugs. The genome sequences for multiple Aspergilli have been determined, and provide a wealth of predictive information about secondary metabolite production. Sequence analysis and gene overexpression strategies have enabled the discovery of novel secondary metabolites and the genes involved in their biosynthesis. The Aspergillus Genome Database (AspGD) provides a central repository for gene annotation and protein information for Aspergillus species. These annotations include Gene Ontology (GO) terms, phenotype data, gene names and descriptions and they are crucial for interpreting both small- and large-scale data and for aiding in the design of new experiments that further Aspergillus research. Results We have manually curated Biological Process GO annotations for all genes in AspGD with recorded functions in secondary metabolite production, adding new GO terms that specifically describe each secondary metabolite. We then leveraged these new annotations to predict roles in secondary metabolism for genes lacking experimental characterization. As a starting point for manually annotating Aspergillus secondary metabolite gene clusters, we used antiSMASH (antibiotics and Secondary Metabolite Analysis SHell) and SMURF (Secondary Metabolite Unknown Regions Finder) algorithms to identify potential clusters in A. nidulans, A. fumigatus, A. niger and A. oryzae, which we subsequently refined through manual curation. Conclusions This set of 266 manually curated secondary metabolite gene clusters will facilitate the investigation of novel Aspergillus secondary metabolites. PMID:23617571

Output ordering and prioritisation system (OOPS): ranking biosynthetic gene clusters to enhance bioactive metabolite discovery.

PubMed

Peña, Alejandro; Del Carratore, Francesco; Cummings, Matthew; Takano, Eriko; Breitling, Rainer

2017-12-18

The rapid increase of publicly available microbial genome sequences has highlighted the presence of hundreds of thousands of biosynthetic gene clusters (BGCs) encoding valuable secondary metabolites. The experimental characterization of new BGCs is extremely laborious and struggles to keep pace with the in silico identification of potential BGCs. Therefore, the prioritisation of promising candidates among computationally predicted BGCs represents a pressing need. Here, we propose an output ordering and prioritisation system (OOPS) which helps sorting identified BGCs by a wide variety of custom-weighted biological and biochemical criteria in a flexible and user-friendly interface. OOPS facilitates a judicious prioritisation of BGCs using G+C content, coding sequence length, gene number, cluster self-similarity and codon bias parameters, as well as enabling the user to rank BGCs based upon BGC type, novelty, and taxonomic distribution. Effective prioritisation of BGCs will help to reduce experimental attrition rates and improve the breadth of bioactive metabolites characterized.

Differentiation of oral bacteria in in vitro cultures and human saliva by secondary electrospray ionization - mass spectrometry

NASA Astrophysics Data System (ADS)

Bregy, Lukas; Müggler, Annick R.; Martinez-Lozano Sinues, Pablo; García-Gómez, Diego; Suter, Yannick; Belibasakis, Georgios N.; Kohler, Malcolm; Schmidlin, Patrick R.; Zenobi, Renato

2015-10-01

The detection of bacterial-specific volatile metabolites may be a valuable tool to predict infection. Here we applied a real-time mass spectrometric technique to investigate differences in volatile metabolic profiles of oral bacteria that cause periodontitis. We coupled a secondary electrospray ionization (SESI) source to a commercial high-resolution mass spectrometer to interrogate the headspace from bacterial cultures and human saliva. We identified 120 potential markers characteristic for periodontal pathogens Aggregatibacter actinomycetemcomitans (n = 13), Porphyromonas gingivalis (n = 70), Tanerella forsythia (n = 30) and Treponema denticola (n = 7) in in vitro cultures. In a second proof-of-principle phase, we found 18 (P. gingivalis, T. forsythia and T. denticola) of the 120 in vitro compounds in the saliva from a periodontitis patient with confirmed infection with P. gingivalis, T. forsythia and T. denticola with enhanced ion intensity compared to two healthy controls. In conclusion, this method has the ability to identify individual metabolites of microbial pathogens in a complex medium such as saliva.

Tools of pathway reconstruction and production of economically relevant plant secondary metabolites in recombinant microorganisms.

PubMed

Dziggel, Clarissa; Schäfer, Holger; Wink, Michael

2017-01-01

Plant secondary metabolites exhibit a variety of biological activities and therefore serve as valuable therapeutics or flavoring compounds. However, the small amounts isolated from plants often cannot meet market demands. This led to the exploration of other, more profitable methods for their production, including plant cell culture systems, chemical synthesis and biotechnological production in microbial hosts. The biotechnological production can be pursued by reconstructing metabolic pathways in selected microbial systems. But due to their complexity, most of these pathways are not completely understood and require the expression of a multitude of genes in a foreign organism. Recently, next generation sequencing data and advances in gene silencing in plants allowed the elucidation of some biosynthetic pathways in more detail. Thus, the de novo production of some natural products, including morphine, strictosidine, artemisinin, taxol ® and resveratrol, in extensively engineered microbial hosts has become feasible. This review highlights the reconstruction of these pathways, missing pieces and novel techniques employed. Copyright © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Transformation of Althaea officinalis L. by Agrobacterium rhizogenes for the production of transgenic roots expressing the anti-HIV microbicide cyanovirin-N.

PubMed

Drake, Pascal M W; de Moraes Madeira, Luisa; Szeto, Tim H; Ma, Julian K-C

2013-12-01

The marshmallow plant (Althaea officinalis L.) has been used for centuries in medicine and other applications. Valuable secondary metabolites have previously been identified in Agrobacterium rhizogenes-generated transgenic 'hairy' roots in this species. In the present study, transgenic roots were produced in A. officinalis using A. rhizogenes. In addition to wild-type lines, roots expressing the anti-human immunodeficiency virus microbicide candidate, cyanovirin-N (CV-N), were generated. Wild-type and CV-N root lines were transferred to liquid culture and increased in mass by 49 and 19 % respectively over a 7 day culture period. In the latter, the concentration of CV-N present in the root tissue was 2.4 μg/g fresh weight, with an average secretion rate into the growth medium of 0.02 μg/ml/24 h. A. officinalis transgenic roots may therefore in the future be used not only as a source of therapeutic secondary metabolites, but also as an expression system for the production of recombinant pharmaceuticals.

Influence of abiotic stress signals on secondary metabolites in plants

PubMed Central

Ramakrishna, Akula; Ravishankar, Gokare Aswathanarayana

2011-01-01

Plant secondary metabolites are unique sources for pharmaceuticals, food additives, flavors, and industrially important biochemicals. Accumulation of such metabolites often occurs in plants subjected to stresses including various elicitors or signal molecules. Secondary metabolites play a major role in the adaptation of plants to the environment and in overcoming stress conditions. Environmental factors viz. temperature, humidity, light intensity, the supply of water, minerals, and CO2 influence the growth of a plant and secondary metabolite production. Drought, high salinity, and freezing temperatures are environmental conditions that cause adverse effects on the growth of plants and the productivity of crops. Plant cell culture technologies have been effective tools for both studying and producing plant secondary metabolites under in vitro conditions and for plant improvement. This brief review summarizes the influence of different abiotic factors include salt, drought, light, heavy metals, frost etc. on secondary metabolites in plants. The focus of the present review is the influence of abiotic factors on secondary metabolite production and some of important plant pharmaceuticals. Also, we describe the results of in vitro cultures and production of some important secondary metabolites obtained in our laboratory. PMID:22041989

Side Streams of Plant Food Processing As a Source of Valuable Compounds: Selected Examples.

PubMed

Schieber, Andreas

2017-02-28

Industrial processing of plant-derived raw materials generates enormous amounts of by-products. On one hand, these by-products constitute a serious disposal issue because they often emerge seasonally and are prone to microbial decay. On the other hand, they are an abundant source of valuable compounds, in particular secondary plant metabolites and cell wall materials, which may be recovered and used to functionalize foods and replace synthetic additives with ingredients of natural origin. This review covers 150 references and presents select studies performed between 2001 and 2016 on the recovery, characterization, and application of valuable constituents from grape pomace, apple pomace, potato peels, tomato pomace, carrot pomace, onion peels, by-products of citrus, mango, banana, and pineapple processing, side streams of olive oil production, and cereal by-products. The criteria used were economic importance, amounts generated, relevance of side streams as a source of valuable compounds, and reviews already published. Despite a plethora of studies carried out on the utilization of side streams, relatively few processes have yet found industrial application.

Blue light decreases tanshinone IIA content in Salvia miltiorrhiza hairy roots via genes regulation.

PubMed

Chen, Ing-Gin J; Lee, Meng-Shiou; Lin, Ming-Kuem; Ko, Chia-Yun; Chang, Wen-Te

2018-06-01

The effect of light-emitting diodes (LEDs) on the production of secondary metabolites in medicinal plants and hairy roots is receiving much attention. The roots and rhizomes of the traditional Chinese medicinal plant Salvia miltiorrhiza Bunge are widely used for treating cardiovascular and cerebrovascular diseases. The main components are liposoluble tanshinones and hydrophilic phenolic acids. Moreover, hairy root culture of S. miltiorrhiza has been used in research of valuable plant-derived secondary metabolites. In this study, we examined the effect of LEDs with different combinations of wavelengths on the content of the main components in hairy roots of S. miltiorrhiza. Tanshinone IIA (TSIIA) content in hairy roots was significantly decreased with all light treatments containing blue light by >60% and was 9 times lower with LED treatment duration changed from 1 week to 3 weeks. HMGR, DXS2, DXR, GGPPS, CPS and CYP76AH1 genes involved in the tanshinone biosynthesis pathway were downregulated by blue light. Furthermore, light quality treatments have different effect on the accumulation of phenolic acids in hairy roots of S. miltiorrhiza. The light treatments 6R3B, 6B3IR, 7RGB and 2R6BUV for 3 weeks could increase rosmarinic acid (RA) content slightly but not salvianolic acid B (SAB) content. Different secondary metabolite contents could be regulated by different wavelength combinations of LEDs. Blue light could reduce TSIIA content in hairy roots of S. miltiorrhiza via gene regulation. Copyright © 2018. Published by Elsevier B.V.

Synergy and contingency as driving forces for the evolution of multiple secondary metabolite production by Streptomyces species.

PubMed

Challis, Gregory L; Hopwood, David A

2003-11-25

In this article we briefly review theories about the ecological roles of microbial secondary metabolites and discuss the prevalence of multiple secondary metabolite production by strains of Streptomyces, highlighting results from analysis of the recently sequenced Streptomyces coelicolor and Streptomyces avermitilis genomes. We address this question: Why is multiple secondary metabolite production in Streptomyces species so commonplace? We argue that synergy or contingency in the action of individual metabolites against biological competitors may, in some cases, be a powerful driving force for the evolution of multiple secondary metabolite production. This argument is illustrated with examples of the coproduction of synergistically acting antibiotics and contingently acting siderophores: two well-known classes of secondary metabolite. We focus, in particular, on the coproduction of beta-lactam antibiotics and beta-lactamase inhibitors, the coproduction of type A and type B streptogramins, and the coregulated production and independent uptake of structurally distinct siderophores by species of Streptomyces. Possible mechanisms for the evolution of multiple synergistic and contingent metabolite production in Streptomyces species are discussed. It is concluded that the production by Streptomyces species of two or more secondary metabolites that act synergistically or contingently against biological competitors may be far more common than has previously been recognized, and that synergy and contingency may be common driving forces for the evolution of multiple secondary metabolite production by these sessile saprophytes.

Synergy and contingency as driving forces for the evolution of multiple secondary metabolite production by Streptomyces species

PubMed Central

Challis, Gregory L.; Hopwood, David A.

2003-01-01

In this article we briefly review theories about the ecological roles of microbial secondary metabolites and discuss the prevalence of multiple secondary metabolite production by strains of Streptomyces, highlighting results from analysis of the recently sequenced Streptomyces coelicolor and Streptomyces avermitilis genomes. We address this question: Why is multiple secondary metabolite production in Streptomyces species so commonplace? We argue that synergy or contingency in the action of individual metabolites against biological competitors may, in some cases, be a powerful driving force for the evolution of multiple secondary metabolite production. This argument is illustrated with examples of the coproduction of synergistically acting antibiotics and contingently acting siderophores: two well-known classes of secondary metabolite. We focus, in particular, on the coproduction of β-lactam antibiotics and β-lactamase inhibitors, the coproduction of type A and type B streptogramins, and the coregulated production and independent uptake of structurally distinct siderophores by species of Streptomyces. Possible mechanisms for the evolution of multiple synergistic and contingent metabolite production in Streptomyces species are discussed. It is concluded that the production by Streptomyces species of two or more secondary metabolites that act synergistically or contingently against biological competitors may be far more common than has previously been recognized, and that synergy and contingency may be common driving forces for the evolution of multiple secondary metabolite production by these sessile saprophytes. PMID:12970466

The use of secondary metabolite profiling in chemotaxonomy of filamentous fungi.

PubMed

Frisvad, Jens C; Andersen, Birgitte; Thrane, Ulf

2008-02-01

A secondary metabolite is a chemical compound produced by a limited number of fungal species in a genus, an order, or even phylum. A profile of secondary metabolites consists of all the different compounds a fungus can produce on a given substratum and includes toxins, antibiotics and other outward-directed compounds. Chemotaxonomy is traditionally restricted to comprise fatty acids, proteins, carbohydrates, or secondary metabolites, but has sometimes been defined so broadly that it also includes DNA sequences. It is not yet possible to use secondary metabolites in phylogeny, because of the inconsistent distribution throughout the fungal kingdom. However, this is the very quality that makes secondary metabolites so useful in classification and identification. Four groups of organisms are particularly good producers of secondary metabolites: plants, fungi, lichen fungi, and actinomycetes, whereas yeasts, protozoa, and animals are less efficient producers. Therefore, secondary metabolites have mostly been used in plant and fungal taxonomy, whereas chemotaxonomy has been neglected in bacteriology. Lichen chemotaxonomy has been based on few biosynthetic families (chemosyndromes), whereas filamentous fungi have been analysed for a wide array of terpenes, polyketides, non-ribosomal peptides, and combinations of these. Fungal chemotaxonomy based on secondary metabolites has been used successfully in large ascomycete genera such as Alternaria, Aspergillus, Fusarium, Hypoxylon, Penicillium, Stachybotrys, Xylaria and in few basidiomycete genera, but not in Zygomycota and Chytridiomycota.

[Secondary Metabolites from Marine Microorganisms. I. Secondary Metabolites from Marine Actinomycetes].

PubMed

Orlova, T I; Bulgakova, V G; Polin, A N

2015-01-01

Review represents data on new active metabolites isolated from marine actinomycetes published in 2007 to 2014. Marine actinomycetes are an unlimited source of novel secondary metabolites with various biological activities. Among them there are antibiotics, anticancer compounds, inhibitors of biochemical processes.

Regulatory cross talk and microbial induction of fungal secondary metabolite gene clusters.

PubMed

Nützmann, Hans-Wilhelm; Schroeckh, Volker; Brakhage, Axel A

2012-01-01

Filamentous fungi are well-known producers of a wealth of secondary metabolites with various biological activities. Many of these compounds such as penicillin, cyclosporine, or lovastatin are of great importance for human health. Genome sequences of filamentous fungi revealed that the encoded potential to produce secondary metabolites is much higher than the actual number of compounds produced during cultivation in the laboratory. This finding encouraged research groups to develop new methods to exploit the silent reservoir of secondary metabolites. In this chapter, we present three successful strategies to induce the expression of secondary metabolite gene clusters. They are based on the manipulation of the molecular processes controlling the biosynthesis of secondary metabolites and the simulation of stimulating environmental conditions leading to altered metabolic profiles. The presented methods were successfully applied to identify novel metabolites. They can be also used to significantly increase product yields. Copyright © 2012 Elsevier Inc. All rights reserved.

Genomics of Secondary Metabolism in Populus: Interactions with Biotic and Abiotic Environments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, F.; Liu, C.; Tschaplinski, T. J.

2009-09-01

Populus trees face constant challenges from the environment during their life cycle. To ensure their survival and reproduction, Populus trees deploy various types of defenses, one of which is the production of a myriad of secondary metabolites. Compounds derived from the shikimate-phenylpropanoid pathway are the most abundant class of secondary metabolites synthesized in Populus. Among other major classes of secondary metabolites in Populus are terpenoids and fatty acid-derivatives. Some of the secondary metabolites made by Populus trees have been functionally characterized. Some others have been associated with certain biological/ecological processes, such as defense against insects and microbial pathogens or acclimationmore » or adaptation to abiotic stresses. Functions of many Populus secondary metabolites remain unclear. The advent of various novel genomic tools will enable us to explore in greater detail the complexity of secondary metabolism in Populus. Detailed data mining of the Populus genome sequence can unveil candidate genes of secondary metabolism. Metabolomic analysis will continue to identify new metabolites synthesized in Populus. Integrated genomics that combines various 'omics' tools will prove to be the most powerful approach in revealing the molecular and biochemical basis underlying the biosynthesis of secondary metabolites in Populus. Characterization of the biological/ecological functions of secondary metabolites as well as their biosynthesis will provide knowledge and tools for genetically engineering the production of seconday metabolites that can lead to the generation of novel, improved Populus varieties.« less

Exploring the Metabolic Stability of Engineered Hairy Roots after 16 Years Maintenance.

PubMed

Häkkinen, Suvi T; Moyano, Elisabeth; Cusidó, Rosa M; Oksman-Caldentey, Kirsi-Marja

2016-01-01

Plants remain a major source of new drugs, leads and fine chemicals. Cell cultures deriving from plants offer a fascinating tool to study plant metabolic pathways and offer large scale production systems for valuable compounds - commercial examples include compounds such as paclitaxel. The major constraint with undifferentiated cell cultures is that they are generally considered to be genetically unstable and cultured cells tend to produce low yields of secondary metabolites especially over time. Hairy roots, a tumor tissue caused by infection of Agrobacterium rhizogenes is a relevant alternative for plant secondary metabolite production for being fast growing, able to grow without phytohormones, and displaying higher stability than undifferentiated cells. Although genetic and metabolic stability has often been connected to transgenic hairy roots, there are only few reports on how a very long-term subculturing effects on the production capacity of hairy roots. In this study, hairy roots producing high tropane alkaloid levels were subjected to 16-year follow-up in relation to genetic and metabolic stability. Cryopreservation method for hairy roots of Hyoscyamus muticus was developed to replace laborious subculturing, and although the post-thaw recovery rates remained low, the expression of transgene remained unaltered in cryopreserved roots. It was shown that although displaying some fluctuation in the metabolite yields, even an exceedingly long-term subculturing was successfully applied without significant loss of metabolic activity.

Metabolomics for secondary metabolite research.

PubMed

Breitling, Rainer; Ceniceros, Ana; Jankevics, Andris; Takano, Eriko

2013-11-11

Metabolomics, the global characterization of metabolite profiles, is becoming an increasingly powerful tool for research on secondary metabolite discovery and production. In this review we discuss examples of recent technological advances and biological applications of metabolomics in the search for chemical novelty and the engineered production of bioactive secondary metabolites.

Discovering the secondary metabolite potential encoded within Entomopathogenic Fungi

USDA-ARS?s Scientific Manuscript database

This article discusses the secondary metabolite potential of the insect pathogens Metarhizium and Beauveria, including a bioinformatics analysis of secondary metabolite genes for which no products are yet identified....

Elevated CO2 affects secondary metabolites in Robinia pseudoacacia L. seedlings in Cd- and Pb-contaminated soils.

PubMed

Jia, Xia; Zhao, Yonghua; Liu, Tuo; Huang, Shuping

2016-10-01

Secondary metabolites play important roles in plant interactions with the environment. The co-occurrence of heavy metal contamination of soils and rising atmospheric CO2 has important effects on plant. It is important to explore the ways in which production of plant secondary metabolites is affected by heavy metals under elevated atmospheric CO2. We examined the effects of elevated CO2 on secondary metabolite contents in Robinia pseudoacacia seedlings grown in Cd- and lead (Pb)-contaminated soils. The increase in secondary metabolites was greater under Cd + Pb exposure than under exposure to individual metals regardless of elevated CO2 with the exception of condensed tannins in leaves and total alkaloids in stems. Except for phenolic compounds and condensed tannins, elevated CO2 was associated with increased secondary metabolite contents in leaves and stems of plants exposed to Cd, Pb, and Cd + Pb compared to plants exposed to ambient CO2 + metals. Changes in saponins in leaves and alkaloids in stems were greater than changes in the other secondary metabolites. Significant interactive effects of CO2, Cd, and Pb on secondary metabolites were observed. Saponins in leaves and alkaloids in stems were more sensitive than other secondary metabolites to elevated CO2 + Cd + Pb. Elevated CO2 could modulate plant protection and defense mechanisms in R. pseudoacacia seedlings exposed to heavy metals by altering the production of secondary metabolites. The increased Cd and Pb uptake under elevated CO2 suggested that R. pseudoacacia may be used in the phytoremediation of heavy metal-contaminated soils under global environmental scenarios. Copyright © 2016 Elsevier Ltd. All rights reserved.

Metabolic engineering with systems biology tools to optimize production of prokaryotic secondary metabolites.

PubMed

Kim, Hyun Uk; Charusanti, Pep; Lee, Sang Yup; Weber, Tilmann

2016-08-27

Covering: 2012 to 2016Metabolic engineering using systems biology tools is increasingly applied to overproduce secondary metabolites for their potential industrial production. In this Highlight, recent relevant metabolic engineering studies are analyzed with emphasis on host selection and engineering approaches for the optimal production of various prokaryotic secondary metabolites: native versus heterologous hosts (e.g., Escherichia coli) and rational versus random approaches. This comparative analysis is followed by discussions on systems biology tools deployed in optimizing the production of secondary metabolites. The potential contributions of additional systems biology tools are also discussed in the context of current challenges encountered during optimization of secondary metabolite production.

Secondary Metabolites from Higher Fungi: Discovery, Bioactivity, and Bioproduction

NASA Astrophysics Data System (ADS)

Zhong, Jian-Jiang; Xiao, Jian-Hui

Medicinal higher fungi such as Cordyceps sinensis and Ganoderma lucidum have been used as an alternative medicine remedy to promote health and longevity for people in China and other regions of the world since ancient times. Nowadays there is an increasing public interest in the secondary metabolites of those higher fungi for discovering new drugs or lead compounds. Current research in drug discovery from medicinal higher fungi involves a multifaceted approach combining mycological, biochemical, pharmacological, metabolic, biosynthetic and molecular techniques. In recent years, many new secondary metabolites from higher fungi have been isolated and are more likely to provide lead compounds for new drug discovery, which may include chemopreventive agents possessing the bioactivity of immunomodulatory, anticancer, etc. However, numerous challenges of secondary metabolites from higher fungi are encountered including bioseparation, identification, biosynthetic metabolism, and screening model issues, etc. Commercial production of secondary metabolites from medicinal mushrooms is still limited mainly due to less information about secondary metabolism and its regulation. Strategies for enhancing secondary metabolite production by medicinal mushroom fermentation include two-stage cultivation combining liquid fermentation and static culture, two-stage dissolved oxygen control, etc. Purification of bioactive secondary metabolites, such as ganoderic acids from G. lucidum, is also very important to pharmacological study and future pharmaceutical application. This review outlines typical examples of the discovery, bioactivity, and bioproduction of secondary metabolites of higher fungi origin.

Isolation and characterization of cyclo-(tryptophanyl-prolyl) and chloramphenicol from Streptomyces sp. SUK 25 with antimethicillin-resistant Staphylococcus aureus activity

PubMed Central

Alshaibani, Muhanna M; Jalil, Juriyati; Sidik, Nik M; Edrada-Ebel, Ruangelie; Zin, Noraziah M

2016-01-01

Background Zingiber spectabile, commonly known as Beehive Ginger, is used as an ethnobotanical plant in many countries as an appetizer or to treat stomachache, toothache, muscle sprain, and as a cure for swelling, sores and cuts. This is the first report of isolation of Streptomyces strain from the root of this plant. Strain Universiti Kebangsaan 25 (SUK 25) has a very high activity to produce secondary metabolites against methicillin-resistant Staphylococcus aureus (MRSA), which is associated with high morbidity and mortality rates due to acquired multidrug resistance genes and causes medication failure in some clinical cases worldwide. Phylogenetic analysis based on the 16S ribosomal RNA gene sequence exhibited that the most closely related strain was Streptomyces omiyaensis NBRC 13449T (99.0% similarity). Aim This study was conducted to carry out the extraction, identification, and biological evaluation of active metabolites isolated from SUK 25 against three MRSA strains, namely, MRSA ATCC 43300, MRSA ATCC 33591, and MRSA ATCC 49476. Materials and methods The production of secondary metabolites by this strain was optimized through Thronton’s media. Isolation, purification, and identification of the bioactive compounds were carried out using reversed-phase high-performance liquid chromatography, high-resolution mass spectrometry, Fourier transform infrared, and one-dimensional and two-dimensional nuclear magnetic resonance. Results During screening procedure, SUK 25 exhibited good antimicrobial potential against several strains of MRSA. The best biological activity was shown from fraction number VII and its subfractions F2 and F3 with minimum inhibitory concentration values at 16 µg/mL and 8 µg/mL, respectively. These two subfractions were identified as diketopiperazine cyclo-(tryptophanyl-prolyl) and chloramphenicol. Conclusion On the basis of obtained results, SUK 25 isolated from Z. spectabile can be regarded as a new valuable source to produce secondary metabolites against bacteria, especially MRSA. PMID:27330275

LC-MS/MS profiling-based secondary metabolite screening of Myxococcus xanthus.

PubMed

Kim, Jiyoung; Choi, Jung Nam; Kim, Pil; Sok, Dai-Eun; Nam, Soo-Wan; Lee, Choong Hwan

2009-01-01

Myxobacteria, Gram-negative soil bacteria, are a well-known producer of bioactive secondary metabolites. Therefore, this study presents a methodological approach for the high-throughput screening of secondary metabolites from 4 wild-type Myxococcus xanthus strains. First, electrospray ionization mass spectrometry (ESI-MS) was performed using extracellular crude extracts. As a result, 22 metabolite peaks were detected, and the metabolite profiling was then conducted using the m/z value, retention time, and MS/MS fragmentation pattern analyses. Among the peaks, one unknown compound peak was identified as analogous to the myxalamid A, B, and C series. An analysis of the tandem mass spectrometric fragmentation patterns and HR-MS identified myxalamid K as a new compound derived from M. xanthus. In conclusion, LC-MS/MS-based chemical screening of diverse secondary metabolites would appear to be an effective approach for discovering unknown microbial secondary metabolites.

Carbon nanotubes as carriers of Panax ginseng metabolites and enhancers of ginsenosides Rb1 and Rg1 anti-cancer activity

NASA Astrophysics Data System (ADS)

Lahiani, Mohamed H.; Eassa, Souzan; Parnell, Charlette; Nima, Zeid; Ghosh, Anindya; Biris, Alexandru S.; Khodakovskaya, Mariya V.

2017-01-01

A major benefit to nanomaterial based-medicine is the ability to provide nanosized vehicles for sporadic metabolites. Here, we describe how the conjugation of valuable ginseng secondary metabolites (ginsenoside Rb1 or Rg1) with carbon nanotubes (CNT) can enhance their anti-proliferative and anti-cancer effects. Ginsenoside-CNT conjugate (Rb-CNT or Rg-CNT) permitted the ginsenosides to be used at a low dose, yet achieve a higher incidence of cancer killing. We were able to demonstrate that the ginsenoside-CNT conjugate can decrease cell viability up to 62% in breast cancer cells (MCF-7) and enhance antiproliferation of drug-resistant pancreatic cancer cells (PANC-1) by 61%. The interaction of the ginsenoside-CNT conjugate with breast cancer cells was studied using Raman Spectroscopy mapping. Total transcriptome profiling (Affymetrix platform) of MCF-7 cells treated with the ginsenoside-CNT conjugate shows that a number of cellular, apoptotic and response to stimulus processes were affected. Therefore, our data confirmed the potential use of CNT as a drug delivery system.

Complete genome sequence of Serratia sp. YD25 (KCTC 42987) presenting strong antagonistic activities to various pathogenic fungi and bacteria.

PubMed

Su, Chun; Liu, Yibo; Sun, Yan; Li, Zhi

2017-03-10

Serratia sp. YD25 (KCTC 42987) was originally isolated from rhizosphere soil in a continuous cropping tobacco-planting farm. Here, we show that its metabolites efficiently suppress the growth of various important pathogenic fungi and bacteria, causing infection in both plants and humans. In addition, Serratia sp. YD25 has a special trait of simultaneous production of both serrawettin W2 and prodigiosin, two important bioactive secondary metabolites produced by Serratia strains. Such co-production has not been reported in other Serratia strains. The complete genome sequence of Serratia sp. YD25 is presented, which is valuable for further exploration of its biotechnological applications in agriculture and medicine. The genome sequence reported here is also useful for understanding the unique regulatory mechanisms underlying biosynthesis of active compounds. Copyright © 2017 Elsevier B.V. All rights reserved.

NMR-based metabolomic analysis of spatial variation in soft corals.

PubMed

He, Qing; Sun, Ruiqi; Liu, Huijuan; Geng, Zhufeng; Chen, Dawei; Li, Yinping; Han, Jiao; Lin, Wenhan; Du, Shushan; Deng, Zhiwei

2014-03-28

Soft corals are common marine organisms that inhabit tropical and subtropical oceans. They are shown to be rich source of secondary metabolites with biological activities. In this work, soft corals from two geographical locations were investigated using ¹H-NMR spectroscopy coupled with multivariate statistical analysis at the metabolic level. A partial least-squares discriminant analysis showed clear separation among extracts of soft corals grown in Sanya Bay and Weizhou Island. The specific markers that contributed to discrimination between soft corals in two origins belonged to terpenes, sterols and N-containing compounds. The satisfied precision of classification obtained indicates this approach using combined ¹H-NMR and chemometrics is effective to discriminate soft corals collected in different geographical locations. The results revealed that metabolites of soft corals evidently depended on living environmental condition, which would provide valuable information for further relevant coastal marine environment evaluation.

Changing trends in biotechnology of secondary metabolism in medicinal and aromatic plants.

PubMed

Gandhi, Sumit G; Mahajan, Vidushi; Bedi, Yashbir S

2015-02-01

Medicinal and aromatic plants are known to produce secondary metabolites that find uses as flavoring agents, fragrances, insecticides, dyes and drugs. Biotechnology offers several choices through which secondary metabolism in medicinal plants can be altered in innovative ways, to overproduce phytochemicals of interest, to reduce the content of toxic compounds or even to produce novel chemicals. Detailed investigation of chromatin organization and microRNAs affecting biosynthesis of secondary metabolites as well as exploring cryptic biosynthetic clusters and synthetic biology options, may provide additional ways to harness this resource. Plant secondary metabolites are a fascinating class of phytochemicals exhibiting immense chemical diversity. Considerable enigma regarding their natural biological functions and the vast array of pharmacological activities, amongst other uses, make secondary metabolites interesting and important candidates for research. Here, we present an update on changing trends in the biotechnological approaches that are used to understand and exploit the secondary metabolism in medicinal and aromatic plants. Bioprocessing in the form of suspension culture, organ culture or transformed hairy roots has been successful in scaling up secondary metabolite production in many cases. Pathway elucidation and metabolic engineering have been useful to get enhanced yield of the metabolite of interest; or, for producing novel metabolites. Heterologous expression of putative plant secondary metabolite biosynthesis genes in a microbe is useful to validate their functions, and in some cases, also, to produce plant metabolites in microbes. Endophytes, the microbes that normally colonize plant tissues, may also produce the phytochemicals produced by the host plant. The review also provides perspectives on future research in the field.

Response Mechanisms in Serratia marcescens IBBPo15 During Organic Solvents Exposure.

PubMed

Stancu, Mihaela Marilena

2016-12-01

Serratia marcescens strain IBB Po15 (KT315653) which possesses serratiopeptidase (ser) gene (KT894207) exhibited good solvent tolerance. During the exposure of S. marcescens IBB Po15 cells to 5 % organic solvents, n-decane was less toxic for this bacterium, compared with n-hexane, cyclohexane, ethylbenzene, toluene, and styrene. The exposure of the S. marcescens IBB Po15 cells to n-hexane, cyclohexane, ethylbenzene, toluene, and styrene induced the formation of large clusters, while in control and n-decane-exposed cells, only organization into small clusters was observed. The data obtained suggested that S. marcescens IBB Po15 cells produced some secondary metabolites (i.e., surfactant serrawettin, red pigment prodigiosin) which are well known as valuable molecules due to their large applications. The exposure of the bacterial cells to organic solvents induced secondary metabolites profile modifications. However, S. marcescens IBB Po15 possesses only alkB1, todM, rhlAB, pswP, mpr, and ser genes, the unspecific amplification of other fragments being acquired also when the primers for alkM1, xylM, ndoM, and C23DO genes were used. Modifications of DNA patterns were not depicted in S. marcescens IBB Po15 cells exposed to organic solvents.

[Synthetic biology toward microbial secondary metabolites and pharmaceuticals].

PubMed

Wu, Lin-Zhuan; Hong, Bin

2013-02-01

Microbial secondary metabolites are one of the major sources of anti-bacterial, anti-fungal, antitumor, anti-virus and immunosuppressive agents for clinical use. Present challenges in microbial pharmaceutical development are the discovery of novel secondary metabolites with significant biological activities, improving the fermentation titers of industrial microbial strains, and production of natural product drugs by re-establishing their biosynthetic pathways in suitable microbial hosts. Synthetic biology, which is developed from systematic biology and metabolic engineering, provides a significant driving force for microbial pharmaceutical development. The review describes the major applications of synthetic biology in novel microbial secondary metabolite discovery, improved production of known secondary metabolites and the production of some natural drugs in genetically modified or reconstructed model microorganisms.

Jasmonate-responsive transcription factors regulating plant secondary metabolism.

PubMed

Zhou, Meiliang; Memelink, Johan

2016-01-01

Plants produce a large variety of secondary metabolites including alkaloids, glucosinolates, terpenoids and phenylpropanoids. These compounds play key roles in plant-environment interactions and many of them have pharmacological activity in humans. Jasmonates (JAs) are plant hormones which induce biosynthesis of many secondary metabolites. JAs-responsive transcription factors (TFs) that regulate the JAs-induced accumulation of secondary metabolites belong to different families including AP2/ERF, bHLH, MYB and WRKY. Here, we give an overview of the types and functions of TFs that have been identified in JAs-induced secondary metabolite biosynthesis, and highlight their similarities and differences in regulating various biosynthetic pathways. We review major recent developments regarding JAs-responsive TFs mediating secondary metabolite biosynthesis, and provide suggestions for further studies. Copyright © 2016 Elsevier Inc. All rights reserved.

Induction of phenolic metabolites and physiological changes in chamomile plants in relation to nitrogen nutrition.

PubMed

Kováčik, Jozef; Klejdus, Bořivoj

2014-01-01

Alternative tools, such as the manipulation of mineral nutrition, may affect secondary metabolite production and thus the nutritional value of food/medicinal plants. We studied the impact of nitrogen (N) nutrition (nitrate/NO3(-) or ammonium/NH4(+) nitrogen) and subsequent nitrogen deficit on phenolic metabolites and physiology in Matricaria chamomilla plants. NH4(+)-fed plants revealed a strong induction of selected phenolic metabolites but, at the same time, growth, Fv/Fm, tissue water content and soluble protein depletion occurred in comparison with NO3(-)-fed ones. On the other hand, NO3(-)-deficient plants also revealed an increase in phenolic metabolites but growth depression was not observed after the given exposure period. Free amino acids were more accumulated in NH4(+)-fed shoots (strong increase in arginine and proline mainly), while the pattern of roots' accumulation was independent of N form. Among phenolic acids, NH4(+) strongly elevated mainly the accumulation of chlorogenic acid. Within flavonoids, flavonols decreased while flavones strongly increased in response to N deficiency. Coumarin-related metabolites revealed a similar increase in herniarin glucosidic precursor in response to N deficiency, while herniarin was more accumulated in NO3(-)- and umbelliferone in NH4(+)-cultured plants. These data indicate a negative impact of NH4(+) as the only source of N on physiology, but also a higher stimulation of some valuable phenols. Nitrogen-induced changes in comparison with other food/crop plants are discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.

Biologically Active Secondary Metabolites from the Fungi.

PubMed

Bills, Gerald F; Gloer, James B

2016-11-01

Many Fungi have a well-developed secondary metabolism. The diversity of fungal species and the diversification of biosynthetic gene clusters underscores a nearly limitless potential for metabolic variation and an untapped resource for drug discovery and synthetic biology. Much of the ecological success of the filamentous fungi in colonizing the planet is owed to their ability to deploy their secondary metabolites in concert with their penetrative and absorptive mode of life. Fungal secondary metabolites exhibit biological activities that have been developed into life-saving medicines and agrochemicals. Toxic metabolites, known as mycotoxins, contaminate human and livestock food and indoor environments. Secondary metabolites are determinants of fungal diseases of humans, animals, and plants. Secondary metabolites exhibit a staggering variation in chemical structures and biological activities, yet their biosynthetic pathways share a number of key characteristics. The genes encoding cooperative steps of a biosynthetic pathway tend to be located contiguously on the chromosome in coregulated gene clusters. Advances in genome sequencing, computational tools, and analytical chemistry are enabling the rapid connection of gene clusters with their metabolic products. At least three fungal drug precursors, penicillin K and V, mycophenolic acid, and pleuromutilin, have been produced by synthetic reconstruction and expression of respective gene clusters in heterologous hosts. This review summarizes general aspects of fungal secondary metabolism and recent developments in our understanding of how and why fungi make secondary metabolites, how these molecules are produced, and how their biosynthetic genes are distributed across the Fungi. The breadth of fungal secondary metabolite diversity is highlighted by recent information on the biosynthesis of important fungus-derived metabolites that have contributed to human health and agriculture and that have negatively impacted crops, food distribution, and human environments.

Aspergillus flavus secondary metabolites: more than just aflatoxins

USDA-ARS?s Scientific Manuscript database

Aspergillus flavus is best known for producing the family of potent carcinogenic secondary metabolites known as aflatoxins. However, this opportunistic plant and animal pathogen also produces numerous other secondary metabolites, many of which have also been shown to be toxic. While about forty of t...

Secondary metabolites in fungus-plant interactions

PubMed Central

Pusztahelyi, Tünde; Holb, Imre J.; Pócsi, István

2015-01-01

Fungi and plants are rich sources of thousands of secondary metabolites. The genetically coded possibilities for secondary metabolite production, the stimuli of the production, and the special phytotoxins basically determine the microscopic fungi-host plant interactions and the pathogenic lifestyle of fungi. The review introduces plant secondary metabolites usually with antifungal effect as well as the importance of signaling molecules in induced systemic resistance and systemic acquired resistance processes. The review also concerns the mimicking of plant effector molecules like auxins, gibberellins and abscisic acid by fungal secondary metabolites that modulate plant growth or even can subvert the plant defense responses such as programmed cell death to gain nutrients for fungal growth and colonization. It also looks through the special secondary metabolite production and host selective toxins of some significant fungal pathogens and the plant response in form of phytoalexin production. New results coming from genome and transcriptional analyses in context of selected fungal pathogens and their hosts are also discussed. PMID:26300892

Microbial secondary metabolites and their impacts on insect symbioses.

PubMed

Klassen, Jonathan L

2014-10-01

All insects host communities of microbes that interact both with the insect and each other. Secondary metabolites are understood to mediate many of these interactions, although examples having robust genetic, chemical and/or ecological evidence are relatively rare. Here, I review secondary metabolites mediating community interactions in the beewolf, entomopathogenic nematode and fungus-growing ant symbioses, using the logic of Koch's postulates to emphasize well-validated symbiotic functions mediated by these metabolites. I especially highlight how these interaction networks are structured by both ecological and evolutionary processes, and how selection acting on secondary metabolite production can be multidimensional. Copyright © 2014 Elsevier Inc. All rights reserved.

Bioactive Secondary Metabolites from a Thai Collection of Soil and Marine-Derived Fungi of the Genera Neosartorya and Aspergillus.

PubMed

Zin, War War May; Prompanya, Chadaporn; Buttachon, Suradet; Kijjoa, Anake

2016-01-01

Fungi are microorganisms which can produce interesting secondary metabolites with structural diversity. Although terrestrial fungi have been extensively investigated for their bioactive secondary metabolites such as antibiotics, marine-derived fungi have only recently attracted attention of Natural Products chemists. Our group has been working on the secondary metabolites produced by the cultures of the fungi of the genera Neosartorya and Aspergillus, collected from soil and marine environments from the tropical region for the purpose of finding new leads for anticancer and antibacterial drugs. This review covers only the secondary metabolites of four soil and six marine-derived species of Neosarorya as well as a new species of marine-derived Aspergillus, investigated by our group. In total, we have isolated fifty three secondary metabolites which can be categorized as polyketides (two), isocoumarins (six), terpenoids (two), meroterpenes (fourteen), alkaloids (twenty eight) and cyclic peptide (one). The anticancer and antibacterial activities of these fungal metabolites are also discussed. Among fifty three secondary metabolites isolated, only the alkaloid eurochevalierine and the cadinene sesquiterpene, isolated from the soil fungus N. pseudofisheri, showed relevant in vitro cytostatic activity against glioblastoma (U373) and non-small cell lung cancer (A549) cell lines while the meroditerpene aszonapyrone A exhibited strong antibacterial activity against multidrug-resistant Gram-positive bacteria and also strong antibiofilm activity in these isolates.

Dereplicating and spatial mapping of secondary metabolites from fungal cultures in situ

DOE PAGES

Kertesz, Vilmos; Van Berkel, Gary J.; Sica, Vincent P.; ...

2015-07-30

Ambient ionization techniques coupled to mass spectrometry have recently become prevalent in natural product research due to their ability to examine secondary metabolites in situ. Identifying, mapping, and monitoring secondary metabolites directly on an organism provides invaluable spatial and temporal details that are lost through traditional extraction processes. Most ambient ionization techniques do not collect mutually supportive data, such as chromatographic retention times and/or UV/VIS spectra, and this can limit the ability to identify certain metabolites, such as differentiating isomers. To overcome this, the droplet liquid microjunction surface sampling probe (droplet LMJ SSP) was coupled with UPLC PDA HRMS MS/MS,more » thus providing separation, retention times, and UV/VIS data used in traditional dereplication protocols. By capturing these mutually supportive data, the identity of secondary metabolites could be confidently and rapidly assigned in situ. Using the droplet LMJ SSP, a protocol was constructed to analyze the secondary metabolite profile of fungal cultures directly without any sample preparation. The results demonstrate that fungal cultures can be dereplicated from the Petri dish, thus identifying secondary metabolites, including isomers, and confirming them against reference standards. As a result, heat maps, similar to mass spectrometry imaging, can be used to ascertain the location and relative concentration of secondary metabolites directly on the surface and/or surroundings of a fungal culture.« less

Species-level assessment of secondary metabolite diversity among Hamigera species and a taxonomic note on the genus

USDA-ARS?s Scientific Manuscript database

Secondary metabolite phenotypes in nine species of the Hamigera clade were analysed to assess their correlations to a multi-gene species-level phylogeny. High-pressure-liquid-chromatography-based chemical analysis revealed three distinctive patterns of secondary metabolite production: (1) the nine s...

Lipopolysaccharide (LPS) stimulation of fungal secondary metabolism

PubMed Central

Khalil, Zeinab G.; Kalansuriya, Pabasara; Capon, Robert J.

2014-01-01

We report on a preliminary investigation of the use the Gram-negative bacterial cell wall constituent lipopolysaccharide (LPS) as a natural chemical cue to stimulate and alter the expression of fungal secondary metabolism. Integrated high-throughput micro-cultivation and micro-analysis methods determined that 6 of 40 (15%) of fungi tested responded to an optimal exposure to LPS (0.6 ng/mL) by activating, enhancing or accelerating secondary metabolite production. To explore the possible mechanisms behind this effect, we employed light and fluorescent microscopy in conjunction with a nitric oxide (NO)-sensitive fluorescent dye and an NO scavenger to provide evidence that LPS stimulation of fungal secondary metabolism coincided with LPS activation of NO. Several case studies demonstrated that LPS stimulation can be scaled from single microplate well (1.5 mL) to preparative (>400 mL) scale cultures. For example, LPS treatment of Penicillium sp. (ACM-4616) enhanced pseurotin A and activated pseurotin A1 and pseurotin A2 biosynthesis, whereas LPS treatment of Aspergillus sp. (CMB-M81F) substantially accelerated and enhanced the biosynthesis of shornephine A and a series of biosynthetically related ardeemins and activated production of neoasterriquinone. As an indication of broader potential, we provide evidence that cultures of Penicillium sp. (CMB-TF0411), Aspergillus niger (ACM-4993F), Rhizopus oryzae (ACM-165F) and Thanatephorus cucumeris (ACM-194F) were responsive to LPS stimulation, the latter two examples being particular noteworthy as neither are known to produce secondary metabolites. Our results encourage the view that LPS stimulation can be used as a valuable tool to expand the molecular discovery potential of fungal strains that either have been exhaustively studied by or are unresponsive to traditional culture methodology. PMID:25379339

Chemical screening method for the rapid identification of microbial sources of marine invertebrate-associated metabolites.

PubMed

Berrue, Fabrice; Withers, Sydnor T; Haltli, Brad; Withers, Jo; Kerr, Russell G

2011-03-21

Marine invertebrates have proven to be a rich source of secondary metabolites. The growing recognition that marine microorganisms associated with invertebrate hosts are involved in the biosynthesis of secondary metabolites offers new alternatives for the discovery and development of marine natural products. However, the discovery of microorganisms producing secondary metabolites previously attributed to an invertebrate host poses a significant challenge. This study describes an efficient chemical screening method utilizing a 96-well plate-based bacterial cultivation strategy to identify and isolate microbial producers of marine invertebrate-associated metabolites.

The secret to a successful relationship: lasting chemistry between ascidians and their symbiotic bacteria

PubMed Central

Schmidt, Eric W.

2014-01-01

Bioactive secondary metabolites are common components of marine animals. In many cases, symbiotic bacteria, and not the animals themselves, synthesize the compounds. Among marine animals, ascidians are good models for understanding these symbioses. Ascidians often contain potently bioactive secondary metabolites as their major extractable components. Strong evidence shows that ~8% of the known secondary metabolites from ascidians are made by symbiotic bacteria, and indirect evidence implicates bacteria in the synthesis of many more. Far from being “secondary” to the animals, secondary metabolites are essential components of the interaction between host animals and their symbiotic bacteria. These interactions have complex underlying biology, but the chemistry is clearly ascidian-species specific. The chemical interactions are ancient in at least some cases, and they are widespread among ascidians. Ascidians maintain secondary metabolic symbioses with bacteria that are phylogenetically diverse, indicating a convergent solution to obtaining secondary metabolites and reinforcing the importance of secondary metabolism in animal survival. PMID:25937788

Production of Secondary Metabolites in Extreme Environments: Food- and Airborne Wallemia spp. Produce Toxic Metabolites at Hypersaline Conditions

PubMed Central

Frisvad, Jens C.; Kocev, Dragi; Džeroski, Sašo; Gunde-Cimerman, Nina

2016-01-01

The food- and airborne fungal genus Wallemia comprises seven xerophilic and halophilic species: W. sebi, W. mellicola, W. canadensis, W. tropicalis, W. muriae, W. hederae and W. ichthyophaga. All listed species are adapted to low water activity and can contaminate food preserved with high amounts of salt or sugar. In relation to food safety, the effect of high salt and sugar concentrations on the production of secondary metabolites by this toxigenic fungus was investigated. The secondary metabolite profiles of 30 strains of the listed species were examined using general growth media, known to support the production of secondary metabolites, supplemented with different concentrations of NaCl, glucose and MgCl2. In more than two hundred extracts approximately one hundred different compounds were detected using high-performance liquid chromatography-diode array detection (HPLC-DAD). Although the genome data analysis of W. mellicola (previously W. sebi sensu lato) and W. ichthyophaga revealed a low number of secondary metabolites clusters, a substantial number of secondary metabolites were detected at different conditions. Machine learning analysis of the obtained dataset showed that NaCl has higher influence on the production of secondary metabolites than other tested solutes. Mass spectrometric analysis of selected extracts revealed that NaCl in the medium affects the production of some compounds with substantial biological activities (wallimidione, walleminol, walleminone, UCA 1064-A and UCA 1064-B). In particular an increase in NaCl concentration from 5% to 15% in the growth media increased the production of the toxic metabolites wallimidione, walleminol and walleminone. PMID:28036382

Chemical-biogeographic survey of secondary metabolism in soil.

PubMed

Charlop-Powers, Zachary; Owen, Jeremy G; Reddy, Boojala Vijay B; Ternei, Melinda A; Brady, Sean F

2014-03-11

In this study, we compare biosynthetic gene richness and diversity of 96 soil microbiomes from diverse environments found throughout the southwestern and northeastern regions of the United States. The 454-pyroseqencing of nonribosomal peptide adenylation (AD) and polyketide ketosynthase (KS) domain fragments amplified from these microbiomes provide a means to evaluate the variation of secondary metabolite biosynthetic diversity in different soil environments. Through soil composition and AD- and KS-amplicon richness analysis, we identify soil types with elevated biosynthetic potential. In general, arid soils show the richest observed biosynthetic diversity, whereas brackish sediments and pine forest soils show the least. By mapping individual environmental amplicon sequences to sequences derived from functionally characterized biosynthetic gene clusters, we identified conserved soil type-specific secondary metabolome enrichment patterns despite significant sample-to-sample sequence variation. These data are used to create chemical biogeographic distribution maps for biomedically valuable families of natural products in the environment that should prove useful for directing the discovery of bioactive natural products in the future.

Microbial secondary metabolites ameliorate growth, in planta contents and lignification in Withania somnifera (L.) Dunal.

PubMed

Singh, Akanksha; Gupta, Rupali; Srivastava, Madhumita; Gupta, M M; Pandey, Rakesh

2016-04-01

In the present investigation, metabolites of Streptomyces sp. MTN14 and Trichoderma harzianum ThU significantly enhanced biomass yield (3.58 and 3.48 fold respectively) in comparison to the control plants. The secondary metabolites treatments also showed significant augmentation (0.75-2.25 fold) in withanolide A, a plant secondary metabolite. Lignin deposition, total phenolic and flavonoid content in W. somnifera were maximally induced in treatment having T. harzianum metabolites. Also, Trichoderma and Streptomyces metabolites were found much better in invoking in planta contents and antioxidants compared with their live culture treatments. Therefore, identification of new molecular effectors from metabolites of efficient microbes may be used as biopesticide and biofertilizer for commercial production of W. somnifera globally.

Regulation and Role of Fungal Secondary Metabolites.

PubMed

Macheleidt, Juliane; Mattern, Derek J; Fischer, Juliane; Netzker, Tina; Weber, Jakob; Schroeckh, Volker; Valiante, Vito; Brakhage, Axel A

2016-11-23

Fungi have the capability to produce a tremendous number of so-called secondary metabolites, which possess a multitude of functions, e.g., communication signals during coexistence with other microorganisms, virulence factors during pathogenic interactions with plants and animals, and in medical applications. Therefore, research on this topic has intensified significantly during the past 10 years and thus knowledge of regulatory mechanisms and the understanding of the role of secondary metabolites have drastically increased. This review aims to depict the complexity of all the regulatory elements involved in controlling the expression of secondary metabolite gene clusters, ranging from epigenetic control and signal transduction pathways to global and specific transcriptional regulators. Furthermore, we give a short overview on the role of secondary metabolites, focusing on the interaction with other microorganisms in the environment as well as on pathogenic relationships.

Antifungal activity of microbial secondary metabolites.

PubMed

Coleman, Jeffrey J; Ghosh, Suman; Okoli, Ikechukwu; Mylonakis, Eleftherios

2011-01-01

Secondary metabolites are well known for their ability to impede other microorganisms. Reanalysis of a screen of natural products using the Caenorhabditis elegans-Candida albicans infection model identified twelve microbial secondary metabolites capable of conferring an increase in survival to infected nematodes. In this screen, the two compound treatments conferring the highest survival rates were members of the epipolythiodioxopiperazine (ETP) family of fungal secondary metabolites, acetylgliotoxin and a derivative of hyalodendrin. The abundance of fungal secondary metabolites indentified in this screen prompted further studies investigating the interaction between opportunistic pathogenic fungi and Aspergillus fumigatus, because of the ability of the fungus to produce a plethora of secondary metabolites, including the well studied ETP gliotoxin. We found that cell-free supernatant of A. fumigatus was able to inhibit the growth of Candida albicans through the production of a secreted product. Comparative studies between a wild-type and an A. fumigatus ΔgliP strain unable to synthesize gliotoxin demonstrate that this secondary metabolite is the major factor responsible for the inhibition. Although toxic to organisms, gliotoxin conferred an increase in survival to C. albicans-infected C. elegans in a dose dependent manner. As A. fumigatus produces gliotoxin in vivo, we propose that in addition to being a virulence factor, gliotoxin may also provide an advantage to A. fumigatus when infecting a host that harbors other opportunistic fungi.

Antifungal Activity of Microbial Secondary Metabolites

PubMed Central

Okoli, Ikechukwu; Mylonakis, Eleftherios

2011-01-01

Secondary metabolites are well known for their ability to impede other microorganisms. Reanalysis of a screen of natural products using the Caenorhabditis elegans-Candida albicans infection model identified twelve microbial secondary metabolites capable of conferring an increase in survival to infected nematodes. In this screen, the two compound treatments conferring the highest survival rates were members of the epipolythiodioxopiperazine (ETP) family of fungal secondary metabolites, acetylgliotoxin and a derivative of hyalodendrin. The abundance of fungal secondary metabolites indentified in this screen prompted further studies investigating the interaction between opportunistic pathogenic fungi and Aspergillus fumigatus, because of the ability of the fungus to produce a plethora of secondary metabolites, including the well studied ETP gliotoxin. We found that cell-free supernatant of A. fumigatus was able to inhibit the growth of Candida albicans through the production of a secreted product. Comparative studies between a wild-type and an A. fumigatus ΔgliP strain unable to synthesize gliotoxin demonstrate that this secondary metabolite is the major factor responsible for the inhibition. Although toxic to organisms, gliotoxin conferred an increase in survival to C. albicans-infected C. elegans in a dose dependent manner. As A. fumigatus produces gliotoxin in vivo, we propose that in addition to being a virulence factor, gliotoxin may also provide an advantage to A. fumigatus when infecting a host that harbors other opportunistic fungi. PMID:21966496

Halogenated compounds from marine algae.

PubMed

Cabrita, Maria Teresa; Vale, Carlos; Rauter, Amélia Pilar

2010-08-09

Marine algae produce a cocktail of halogenated metabolites with potential commercial value. Structures exhibited by these compounds go from acyclic entities with a linear chain to complex polycyclic molecules. Their medical and pharmaceutical application has been investigated for a few decades, however other properties, such as antifouling, are not to be discarded. Many compounds were discovered in the last years, although the need for new drugs keeps this field open as many algal species are poorly screened. The ecological role of marine algal halogenated metabolites has somehow been overlooked. This new research field will provide valuable and novel insight into the marine ecosystem dynamics as well as a new approach to comprehending biodiversity. Furthermore, understanding interactions between halogenated compound production by algae and the environment, including anthropogenic or global climate changes, is a challenging target for the coming years. Research of halogenated metabolites has been more focused on macroalgae than on phytoplankton. However, phytoplankton could be a very promising material since it is the base of the marine food chain with quick adaptation to environmental changes, which undoubtedly has consequences on secondary metabolism. This paper reviews recent progress on this field and presents trends on the role of marine algae as producers of halogenated compounds.

Halogenated Compounds from Marine Algae

PubMed Central

Cabrita, Maria Teresa; Vale, Carlos; Rauter, Amélia Pilar

2010-01-01

Marine algae produce a cocktail of halogenated metabolites with potential commercial value. Structures exhibited by these compounds go from acyclic entities with a linear chain to complex polycyclic molecules. Their medical and pharmaceutical application has been investigated for a few decades, however other properties, such as antifouling, are not to be discarded. Many compounds were discovered in the last years, although the need for new drugs keeps this field open as many algal species are poorly screened. The ecological role of marine algal halogenated metabolites has somehow been overlooked. This new research field will provide valuable and novel insight into the marine ecosystem dynamics as well as a new approach to comprehending biodiversity. Furthermore, understanding interactions between halogenated compound production by algae and the environment, including anthropogenic or global climate changes, is a challenging target for the coming years. Research of halogenated metabolites has been more focused on macroalgae than on phytoplankton. However, phytoplankton could be a very promising material since it is the base of the marine food chain with quick adaptation to environmental changes, which undoubtedly has consequences on secondary metabolism. This paper reviews recent progress on this field and presents trends on the role of marine algae as producers of halogenated compounds. PMID:20948909

Dereplicating and Spatial Mapping of Secondary Metabolites from Fungal Cultures in Situ.

PubMed

Sica, Vincent P; Raja, Huzefa A; El-Elimat, Tamam; Kertesz, Vilmos; Van Berkel, Gary J; Pearce, Cedric J; Oberlies, Nicholas H

2015-08-28

Ambient ionization mass spectrometry techniques have recently become prevalent in natural product research due to their ability to examine secondary metabolites in situ. These techniques retain invaluable spatial and temporal details that are lost through traditional extraction processes. However, most ambient ionization techniques do not collect mutually supportive data, such as chromatographic retention times and/or UV/vis spectra, and this can limit the ability to identify certain metabolites, such as differentiating isomers. To overcome this, the droplet-liquid microjunction-surface sampling probe (droplet-LMJ-SSP) was coupled with UPLC-PDA-HRMS-MS/MS, thus providing separation, retention times, MS data, and UV/vis data used in traditional dereplication protocols. By capturing these mutually supportive data, the identity of secondary metabolites can be confidently and rapidly assigned in situ. Using the droplet-LMJ-SSP, a protocol was constructed to analyze the secondary metabolite profile of fungal cultures without any sample preparation. The results demonstrate that fungal cultures can be dereplicated from the Petri dish, thus identifying secondary metabolites, including isomers, and confirming them against reference standards. Furthermore, heat maps, similar to mass spectrometry imaging, can be used to ascertain the location and relative concentration of secondary metabolites directly on the surface and/or surroundings of a fungal culture.

Physiological and biochemical effect of neem and other Meliaceae plants secondary metabolites against Lepidopteran insects

PubMed Central

Senthil-Nathan, Sengottayan

2013-01-01

This review described the physiological and biochemical effects of various secondary metabolites from Meliaceae against major Lepidopteran insect pest including, Noctuidae and Pyralidae. The biochemical effect of major Meliaceae secondary metabolites were discussed more in this review. Several enzymes based on food materials have critical roles in nutritional indices (food utilization) of the insect pest population. Several research work has been referred and the effect of Meliaceae secondary metabolites on feeding parameters of insects by demonstrating food consumption, approximate digestibility of consumed food, efficiency of converting the ingested food to body substance, efficiency of converting digested food to body substance and consumption index was reviewed in detail. Further how the digestive enzymes including a-Amylases, α and β-glucosidases (EC 3.2.1.1), lipases (EC 3.1.1) Proteases, serine, cysteine, and aspartic proteinases affected by the Meliaceae secondary metabolites was reviewed. Further effect of Meliaceae secondary metabolites on detoxifying enzymes have been found to react against botanical insecticides including general esterases (EST), glutathione S-transferase (GST) and phosphatases was reviewed. Alkaline phosphatase (ALP, E.C.3.1.3.1) and acid phosphatase (ACP, E.C.3.1.3.2) are hydrolytic enzymes, which hydrolyze phosphomonoesters under alkaline or acid conditions, respectively. These enzymes were affected by the secondary metabolites treatment. The detailed mechanism of action was further explained in this review. Acethylcholine esterase (AChE) is a key enzyme that terminates nerve impulses by catalyzing the hydrolysis of neurotransmitter, acetylcholine, in the nervous system of various organisms. How the AChE activity was altered by the Meliaceae secondary metabolites reviewed in detail. PMID:24391591

New natural products identified by combined genomics-metabolomics profiling of marine Streptomyces sp. MP131-18.

PubMed

Paulus, Constanze; Rebets, Yuriy; Tokovenko, Bogdan; Nadmid, Suvd; Terekhova, Larisa P; Myronovskyi, Maksym; Zotchev, Sergey B; Rückert, Christian; Braig, Simone; Zahler, Stefan; Kalinowski, Jörn; Luzhetskyy, Andriy

2017-02-10

Marine actinobacteria are drawing more and more attention as a promising source of new natural products. Here we report isolation, genome sequencing and metabolic profiling of new strain Streptomyces sp. MP131-18 isolated from marine sediment sample collected in the Trondheim Fjord, Norway. The 16S rRNA and multilocus phylogenetic analysis showed that MP131-18 belongs to the genus Streptomyces. The genome of MP131-18 isolate was sequenced, and 36 gene clusters involved in the biosynthesis of 18 different types of secondary metabolites were predicted using antiSMASH analysis. The combined genomics-metabolics profiling of the strain led to the identification of several new biologically active compounds. As a result, the family of bisindole pyrroles spiroindimicins was extended with two new members, spiroindimicins E and F. Furthermore, prediction of the biosynthetic pathway for unusual α-pyrone lagunapyrone isolated from MP131-18 resulted in foresight and identification of two new compounds of this family - lagunapyrones D and E. The diversity of identified and predicted compounds from Streptomyces sp. MP131-18 demonstrates that marine-derived actinomycetes are not only a promising source of new natural products, but also represent a valuable pool of genes for combinatorial biosynthesis of secondary metabolites.

New natural products identified by combined genomics-metabolomics profiling of marine Streptomyces sp. MP131-18

PubMed Central

Paulus, Constanze; Rebets, Yuriy; Tokovenko, Bogdan; Nadmid, Suvd; Terekhova, Larisa P.; Myronovskyi, Maksym; Zotchev, Sergey B.; Rückert, Christian; Braig, Simone; Zahler, Stefan; Kalinowski, Jörn; Luzhetskyy, Andriy

2017-01-01

Marine actinobacteria are drawing more and more attention as a promising source of new natural products. Here we report isolation, genome sequencing and metabolic profiling of new strain Streptomyces sp. MP131-18 isolated from marine sediment sample collected in the Trondheim Fjord, Norway. The 16S rRNA and multilocus phylogenetic analysis showed that MP131-18 belongs to the genus Streptomyces. The genome of MP131-18 isolate was sequenced, and 36 gene clusters involved in the biosynthesis of 18 different types of secondary metabolites were predicted using antiSMASH analysis. The combined genomics-metabolics profiling of the strain led to the identification of several new biologically active compounds. As a result, the family of bisindole pyrroles spiroindimicins was extended with two new members, spiroindimicins E and F. Furthermore, prediction of the biosynthetic pathway for unusual α-pyrone lagunapyrone isolated from MP131-18 resulted in foresight and identification of two new compounds of this family – lagunapyrones D and E. The diversity of identified and predicted compounds from Streptomyces sp. MP131-18 demonstrates that marine-derived actinomycetes are not only a promising source of new natural products, but also represent a valuable pool of genes for combinatorial biosynthesis of secondary metabolites. PMID:28186197

Antiproliferative, Antibacterial and Antifungal Activity of the Lichen Xanthoria parietina and Its Secondary Metabolite Parietin

PubMed Central

Basile, Adriana; Rigano, Daniela; Loppi, Stefano; Di Santi, Annalisa; Nebbioso, Angela; Sorbo, Sergio; Conte, Barbara; Paoli, Luca; De Ruberto, Francesca; Molinari, Anna Maria; Altucci, Lucia; Bontempo, Paola

2015-01-01

Lichens are valuable natural resources used for centuries throughout the world as medicine, food, fodder, perfume, spices and dyes, as well as for other miscellaneous purposes. This study investigates the antiproliferative, antibacterial and antifungal activity of the acetone extract of the lichen Xanthoria parietina (Linnaeus) Theodor Fries and its major secondary metabolite, parietin. The extract and parietin were tested for antimicrobial activity against nine American Type Culture Collection standard and clinically isolated bacterial strains, and three fungal strains. Both showed strong antibacterial activity against all bacterial strains and matched clinical isolates, particularly against Staphylococcus aureus from standard and clinical sources. Among the fungi tested, Rhizoctonia solani was the most sensitive. The antiproliferative effects of the extract and parietin were also investigated in human breast cancer cells. The extract inhibited proliferation and induced apoptosis, both effects being accompanied by modulation of expression of cell cycle regulating genes such as p16, p27, cyclin D1 and cyclin A. It also mediated apoptosis by activating extrinsic and intrinsic cell death pathways, modulating Tumor Necrosis Factor-related apoptosis-inducing ligand (TRAIL) and B-cell lymphoma 2 (Bcl-2), and inducing Bcl-2-associated agonist of cell death (BAD) phosphorylation. Our results indicate that Xanthoria parietina is a major potential source of antimicrobial and anticancer substances. PMID:25860944

Two new pyrrolo-2-aminoimidazoles from a Myanmarese marine sponge, Clathria prolifera.

PubMed

Woo, So-Yeun; Win, Nwet Nwet; Wong, Chin Piow; Ito, Takuya; Hoshino, Shotaro; Ngwe, Hla; Aye, Aung Aung; Han, Nang Mya; Zhang, Huiping; Hayashi, Fumiaki; Abe, Ikuro; Morita, Hiroyuki

2018-06-01

Marine organisms such as marine sponges and soft corals are valuable sources of pharmacologically active secondary metabolites. In our ongoing research on the discovery of new secondary metabolites from marine organisms, two new pyrrolo-2-aminoimidazoles, clathriroles A (1) and B (2), were isolated from the water-soluble portion prepared from the methanol and acetone (2:1) extract of the marine sponge, Clathria prolifera, collected in Myanmar. The chemical structures of the isolated compounds were determined using extensive spectroscopic techniques, including NMR, HRESIMS, IR, and optical rotation, and comparisons with the reported literature. The spectroscopic analyses of 1 and 2 suggested that 1 is an enantiomer of antifungal N-methylmanzacidin C isolated from the marine sponge Axinella brevistyla, whereas 2 is a diastereomer of manzacidin D at C-11 isolated from the marine sponge Astrosclera willeyana. To the best of our knowledge, this is the first report of the isolation of the pyrrolo-2-aminoimidazole compounds from C. prolifera. Furthermore, in contrast to the potency of N-methylmanzacidin C against Saccharomyces cerevisiae, the antifungal assay revealed that 1 and 2 lack any activity against this strain. Thus, these observations may suggest that the absolute configurations at both C-9 and C-11 play an important role in controlling the antifungal activity of this type of compound.

Extraction and applications of cyanotoxins and other cyanobacterial secondary metabolites.

PubMed

Haque, Fatima; Banayan, Sara; Yee, Josephine; Chiang, Yi Wai

2017-09-01

The rapid proliferation of cyanobacteria in bodies of water has caused cyanobacterial blooms, which have become an increasing cause of concern, largely due to the presence of toxic secondary metabolites (or cyanotoxins). Cyanotoxins are the toxins produced by cyanobacteria that may be harmful to surrounding wildlife. They include hepatotoxins, neurotoxins and dermatotoxins, and are classified based on the organs they affect. There are also non-toxic secondary metabolites that include chelators and UV-absorbing compounds. This paper summarizes the optimal techniques for secondary metabolite extraction and the possible useful products that can be obtained from cyanobacteria, with additional focus given to products derived from secondary metabolites. It becomes evident that the potential for their use as biocides, chelators, biofuels, biofertilizers, pharmaceuticals, food and feed, and cosmetics has not yet been comprehensively studied or extensively implemented. Copyright © 2017 Elsevier Ltd. All rights reserved.

Microbial secondary metabolites in homes in association with moisture damage and asthma.

PubMed

Kirjavainen, P V; Täubel, M; Karvonen, A M; Sulyok, M; Tiittanen, P; Krska, R; Hyvärinen, A; Pekkanen, J

2016-06-01

We aimed to characterize the presence of microbial secondary metabolites in homes and their association with moisture damage, mold, and asthma development. Living room floor dust was analyzed by LC-MS/MS for 333 secondary metabolites from 93 homes of 1-year-old children. Moisture damage was present in 15 living rooms. At 6 years, 8 children had active and 15 lifetime doctor-diagnosed asthma. The median number of different metabolites per house was 17 (range 8-29) and median sum load 65 (4-865) ng/m(2) . Overall 42 different metabolites were detected. The number of metabolites present tended to be higher in homes with mold odor or moisture damage. The higher sum loads and number of metabolites with loads over 10 ng/m(2) were associated with lower prevalence of active asthma at 6 years (aOR 0.06 (95% CI <0.001-0.96) and 0.05 (<0.001-0.56), respectively). None of the individual metabolites, which presence tended (P < 0.2) to be increased by moisture damage or mold, were associated with increased risk of asthma. Microbial secondary metabolites are ubiquitously present in home floor dust. Moisture damage and mold tend to increase their numbers and amount. There was no evidence indicating that the secondary metabolites determined would explain the association between moisture damage, mold, and the development of asthma. © 2015 The Authors. Indoor Air published by John Wiley & Sons Ltd.

Marine natural product peptides with therapeutic potential: Chemistry, biosynthesis, and pharmacology.

PubMed

Gogineni, Vedanjali; Hamann, Mark T

2018-01-01

The oceans are a uniquely rich source of bioactive metabolites, of which sponges have been shown to be among the most prolific producers of diverse bioactive secondary metabolites with valuable therapeutic potential. Much attention has been focused on marine bioactive peptides due to their novel chemistry and diverse biological properties. As summarized in this review, marine peptides are known to exhibit various biological activities such as antiviral, anti-proliferative, antioxidant, anti-coagulant, anti-hypertensive, anti-cancer, antidiabetic, antiobesity, and calcium-binding activities. This review focuses on the chemistry and biology of peptides isolated from sponges, bacteria, cyanobacteria, fungi, ascidians, and other marine sources. The role of marine invertebrate microbiomes in natural products biosynthesis is discussed in this review along with the biosynthesis of modified peptides from different marine sources. The status of peptides in various phases of clinical trials is presented, as well as the development of modified peptides including optimization of PK and bioavailability. Copyright © 2017 Elsevier B.V. All rights reserved.

Novel anti-infective compounds from marine bacteria.

PubMed

Rahman, Hafizur; Austin, Brian; Mitchell, Wilfrid J; Morris, Peter C; Jamieson, Derek J; Adams, David R; Spragg, Andrew Mearns; Schweizer, Michael

2010-03-05

As a result of the continuous evolution of microbial pathogens towards antibiotic-resistance, there have been demands for the development of new and effective antimicrobial compounds. Since the 1960s, the scientific literature has accumulated many publications about novel pharmaceutical compounds produced by a diverse range of marine bacteria. Indeed, marine micro-organisms continue to be a productive and successful focus for natural products research, with many newly isolated compounds possessing potentially valuable pharmacological activities. In this regard, the marine environment will undoubtedly prove to be an increasingly important source of novel antimicrobial metabolites, and selective or targeted approaches are already enabling the recovery of a significant number of antibiotic-producing micro-organisms. The aim of this review is to consider advances made in the discovery of new secondary metabolites derived from marine bacteria, and in particular those effective against the so called "superbugs", including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin resistant enterococci (VRE), which are largely responsible for the increase in numbers of hospital acquired, i.e., nosocomial, infections.

Activation of the Silent Secondary Metabolite Production by Introducing Neomycin-Resistance in a Marine-Derived Penicillium purpurogenum G59

PubMed Central

Wu, Chang-Jing; Yi, Le; Cui, Cheng-Bin; Li, Chang-Wei; Wang, Nan; Han, Xiao

2015-01-01

Introduction of neomycin-resistance into a marine-derived, wild-type Penicillium purpurogenum G59 resulted in activation of silent biosynthetic pathways for the secondary metabolite production. Upon treatment of G59 spores with neomycin and dimethyl sulfoxide (DMSO), a total of 56 mutants were obtained by single colony isolation. The acquired resistance of mutants to neomycin was testified by the resistance test. In contrast to the G59 strain, the EtOAc extracts of 28 mutants inhibited the human cancer K562 cells, indicating that the 28 mutants have acquired the capability to produce bioactive metabolites. HPLC-photodiode array detector (PDAD)-UV and HPLC-electron spray ionization (ESI)-MS analyses further indicated that diverse secondary metabolites have been newly produced in the bioactive mutant extracts. Followed isolation and characterization demonstrated that five bioactive secondary metabolites, curvularin (1), citrinin (2), penicitrinone A (3), erythro-23-O-methylneocyclocitrinol (4) and 22E-7α-methoxy-5α,6α-epoxyergosta-8(14),22-dien-3β-ol (5), were newly produced by a mutant, 4-30, compared to the G59 strain. All 1–5 were also not yet found in the secondary metabolites of other wild type P. purpurogenum strains. Compounds 1–5 inhibited human cancer K562, HL-60, HeLa and BGC-823 cells to varying extents. Both present bioassays and chemical investigations demonstrated that the introduction of neomycin-resistance into the marine-derived fungal G59 strain could activate silent secondary metabolite production. The present work not only extended the previous DMSO-mediated method for introducing drug-resistance in fungi both in DMSO concentrations and antibiotics, but also additionally exemplified effectiveness of this method for activating silent fungal secondary metabolites. This method could be applied to other fungal isolates to elicit their metabolic potentials to investigate secondary metabolites from silent biosynthetic pathways. PMID:25913704

Activation of the silent secondary metabolite production by introducing neomycin-resistance in a marine-derived Penicillium purpurogenum G59.

PubMed

Wu, Chang-Jing; Yi, Le; Cui, Cheng-Bin; Li, Chang-Wei; Wang, Nan; Han, Xiao

2015-04-22

Introduction of neomycin-resistance into a marine-derived, wild-type Penicillium purpurogenum G59 resulted in activation of silent biosynthetic pathways for the secondary metabolite production. Upon treatment of G59 spores with neomycin and dimethyl sulfoxide (DMSO), a total of 56 mutants were obtained by single colony isolation. The acquired resistance of mutants to neomycin was testified by the resistance test. In contrast to the G59 strain, the EtOAc extracts of 28 mutants inhibited the human cancer K562 cells, indicating that the 28 mutants have acquired the capability to produce bioactive metabolites. HPLC-photodiode array detector (PDAD)-UV and HPLC-electron spray ionization (ESI)-MS analyses further indicated that diverse secondary metabolites have been newly produced in the bioactive mutant extracts. Followed isolation and characterization demonstrated that five bioactive secondary metabolites, curvularin (1), citrinin (2), penicitrinone A (3), erythro-23-O-methylneocyclocitrinol (4) and 22E-7α-methoxy-5α, 6α-epoxyergosta-8(14),22-dien-3β-ol (5), were newly produced by a mutant, 4-30, compared to the G59 strain. All 1-5 were also not yet found in the secondary metabolites of other wild type P. purpurogenum strains. Compounds 1-5 inhibited human cancer K562, HL-60, HeLa and BGC-823 cells to varying extents. Both present bioassays and chemical investigations demonstrated that the introduction of neomycin-resistance into the marine-derived fungal G59 strain could activate silent secondary metabolite production. The present work not only extended the previous DMSO-mediated method for introducing drug-resistance in fungi both in DMSO concentrations and antibiotics, but also additionally exemplified effectiveness of this method for activating silent fungal secondary metabolites. This method could be applied to other fungal isolates to elicit their metabolic potentials to investigate secondary metabolites from silent biosynthetic pathways.

Recent advances in reconstructing microbial secondary metabolites biosynthesis in Aspergillus spp.

PubMed

He, Yi; Wang, Bin; Chen, Wanping; Cox, Russell J; He, Jingren; Chen, Fusheng

High throughput genome sequencing has revealed a multitude of potential secondary metabolites biosynthetic pathways that remain cryptic. Pathway reconstruction coupled with genetic engineering via heterologous expression enables discovery of novel compounds, elucidation of biosynthetic pathways, and optimization of product yields. Apart from Escherichia coli and yeast, fungi, especially Aspergillus spp., are well known and efficient heterologous hosts. This review summarizes recent advances in heterologous expression of microbial secondary metabolite biosynthesis in Aspergillus spp. We also discuss the technological challenges and successes in regard to heterologous host selection and DNA assembly behind the reconstruction of microbial secondary metabolite biosynthesis. Copyright © 2018 Elsevier Inc. All rights reserved.

Current approaches toward production of secondary plant metabolites

PubMed Central

Hussain, Md. Sarfaraj; Fareed, Sheeba; Ansari, Saba; Rahman, Md. Akhlaquer; Ahmad, Iffat Zareen; Saeed, Mohd.

2012-01-01

Plants are the tremendous source for the discovery of new products with medicinal importance in drug development. Today several distinct chemicals derived from plants are important drugs, which are currently used in one or more countries in the world. Secondary metabolites are economically important as drugs, flavor and fragrances, dye and pigments, pesticides, and food additives. Many of the drugs sold today are simple synthetic modifications or copies of the naturally obtained substances. The evolving commercial importance of secondary metabolites has in recent years resulted in a great interest in secondary metabolism, particularly in the possibility of altering the production of bioactive plant metabolites by means of tissue culture technology. Plant cell and tissue culture technologies can be established routinely under sterile conditions from explants, such as plant leaves, stems, roots, and meristems for both the ways for multiplication and extraction of secondary metabolites. In vitro production of secondary metabolite in plant cell suspension cultures has been reported from various medicinal plants, and bioreactors are the key step for their commercial production. Based on this lime light, the present review is aimed to cover phytotherapeutic application and recent advancement for the production of some important plant pharmaceuticals. PMID:22368394

[Determination of the profiles of secondary metabolites characteristic of Alternaria strains isolated from tomato].

PubMed

Benavidez Rozo, Martha Elizabeth; Patriarca, Andrea; Cabrera, Gabriela; Fernández Pinto, Virginia E

2014-01-01

Many Alternaria species have been studied for their ability to produce bioactive secondary metabolites, such as tentoxin (TEN), some of which have toxic properties. The main food contaminant toxins are tenuazonic acid, alternariol (AOH), alternariol monomethyl ether (AME), altenuene, and altertoxins i, ii and iii. To determine the profiles of secondary metabolites characteristic of Alternaria strains isolated from tomato for their chemotaxonomic classification. The profiles of secondary metabolites were determined by HPLC MS. The Alternaria isolates obtained from spoiled tomatoes belong, according to their morphological characteristics, to the species groups Alternaria alternata, Alternaria tenuissima and Alternaria arborescens, with A. tenuissima being the most frequent. The most frequent profiles of secondary metabolites belonging to the species groups A. alternata (AOH, AME, TEN), A. tenuissima (AOH, AME, TEN, tenuazonic acid) and A. arborescens (AOH, AME, TEN, tenuazonic acid) were determined, with some isolates of the latter being able to synthesize AAL toxins. Secondary metabolite profiles are a useful tool for the differentiation of small spored Alternaria isolates not easily identifiable by their morphological characteristics. Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

Secondary metabolites in floral nectar reduce parasite infections in bumblebees.

PubMed

Richardson, Leif L; Adler, Lynn S; Leonard, Anne S; Andicoechea, Jonathan; Regan, Karly H; Anthony, Winston E; Manson, Jessamyn S; Irwin, Rebecca E

2015-03-22

The synthesis of secondary metabolites is a hallmark of plant defence against herbivores. These compounds may be detrimental to consumers, but can also protect herbivores against parasites. Floral nectar commonly contains secondary metabolites, but little is known about the impacts of nectar chemistry on pollinators, including bees. We hypothesized that nectar secondary metabolites could reduce bee parasite infection. We inoculated individual bumblebees with Crithidia bombi, an intestinal parasite, and tested effects of eight naturally occurring nectar chemicals on parasite population growth. Secondary metabolites strongly reduced parasite load, with significant effects of alkaloids, terpenoids and iridoid glycosides ranging from 61 to 81%. Using microcolonies, we also investigated costs and benefits of consuming anabasine, the compound with the strongest effect on parasites, in infected and uninfected bees. Anabasine increased time to egg laying, and Crithidia reduced bee survival. However, anabasine consumption did not mitigate the negative effects of Crithidia, and Crithidia infection did not alter anabasine consumption. Our novel results highlight that although secondary metabolites may not rescue survival in infected bees, they may play a vital role in mediating Crithidia transmission within and between colonies by reducing Crithidia infection intensities. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Secondary metabolites in floral nectar reduce parasite infections in bumblebees

PubMed Central

Richardson, Leif L.; Adler, Lynn S.; Leonard, Anne S.; Andicoechea, Jonathan; Regan, Karly H.; Anthony, Winston E.; Manson, Jessamyn S.; Irwin, Rebecca E.

2015-01-01

The synthesis of secondary metabolites is a hallmark of plant defence against herbivores. These compounds may be detrimental to consumers, but can also protect herbivores against parasites. Floral nectar commonly contains secondary metabolites, but little is known about the impacts of nectar chemistry on pollinators, including bees. We hypothesized that nectar secondary metabolites could reduce bee parasite infection. We inoculated individual bumblebees with Crithidia bombi, an intestinal parasite, and tested effects of eight naturally occurring nectar chemicals on parasite population growth. Secondary metabolites strongly reduced parasite load, with significant effects of alkaloids, terpenoids and iridoid glycosides ranging from 61 to 81%. Using microcolonies, we also investigated costs and benefits of consuming anabasine, the compound with the strongest effect on parasites, in infected and uninfected bees. Anabasine increased time to egg laying, and Crithidia reduced bee survival. However, anabasine consumption did not mitigate the negative effects of Crithidia, and Crithidia infection did not alter anabasine consumption. Our novel results highlight that although secondary metabolites may not rescue survival in infected bees, they may play a vital role in mediating Crithidia transmission within and between colonies by reducing Crithidia infection intensities. PMID:25694627

Role of growth media and chemical enhancers in secondary metabolites production from Aspergillus carbonarius (NRL-369) and their pharmaceutical potentials.

PubMed

Khan, Abid Ali; Bacha, Nafess; Ahmad, Bashir; Cox, R J; Bakht, Jehan

2016-07-01

The present study investigates the effect of different growth media and chemical enhancer on silent genes in Aspergillus carbonarius (NRL-369) for secondary metabolites production and its in vitro biological activities. Results revealed that Aspergillus carbonarius (NRL-369) grown in Czapeak yeast extract broth medium produced more metabolites compared with other media. Chemical epigenetic modifiers (suberoyl-anilide hydroxamic acid (SAHA) and 5-azacytidine (5-AZA) at concentration of 15mM were effective for the expression of silent genes resulting in increased secondary metabolites production. Secondary metabolites extracted in ethyl acetate and fractionized in n-Hexane showed variable degree of growth inhibitions of the tested microorganisms. Similarly, these samples were also active against brine shrimps and Lemna.

Lichen secondary metabolites affect growth of Physcomitrella patens by allelopathy.

PubMed

Goga, Michal; Antreich, Sebastian J; Bačkor, Martin; Weckwerth, Wolfram; Lang, Ingeborg

2017-05-01

Lichen secondary metabolites can function as allelochemicals and affect the development and growth of neighboring bryophytes, fungi, vascular plants, microorganisms, and even other lichens. Lichen overgrowth on bryophytes is frequently observed in nature even though mosses grow faster than lichens, but there is still little information on the interactions between lichens and bryophytes.In the present study, we used extracts from six lichen thalli containing secondary metabolites like usnic acid, protocetraric acid, atranorin, lecanoric acid, nortistic acid, and thamnolic acid. To observe the influence of these metabolites on bryophytes, the moss Physcomitrella patens was cultivated for 5 weeks under laboratory conditions and treated with lichen extracts. Toxicity of natural mixtures of secondary metabolites was tested at three selected doses (0.001, 0.01, and 0.1 %). When the mixture contained substantial amounts of usnic acid, we observed growth inhibition of protonemata and reduced development of gametophores. Significant differences in cell lengths and widths were also noticed. Furthermore, usnic acid had a strong effect on cell division in protonemata suggesting a strong impact on the early stages of bryophyte development by allelochemicals contained in the lichen secondary metabolites.Biological activities of lichen secondary metabolites were confirmed in several studies such as antiviral, antibacterial, antitumor, antiherbivore, antioxidant, antipyretic, and analgetic action or photoprotection. This work aimed to expand the knowledge on allelopathic effects on bryophyte growth.

Amino Acid and Secondary Metabolite Production in Embryogenic and Non-Embryogenic Callus of Fingerroot Ginger (Boesenbergia rotunda).

PubMed

Ng, Theresa Lee Mei; Karim, Rezaul; Tan, Yew Seong; Teh, Huey Fang; Danial, Asma Dazni; Ho, Li Sim; Khalid, Norzulaani; Appleton, David Ross; Harikrishna, Jennifer Ann

2016-01-01

Interest in the medicinal properties of secondary metabolites of Boesenbergia rotunda (fingerroot ginger) has led to investigations into tissue culture of this plant. In this study, we profiled its primary and secondary metabolites, as well as hormones of embryogenic and non-embryogenic (dry and watery) callus and shoot base, Ultra Performance Liquid Chromatography-Mass Spectrometry together with histological characterization. Metabolite profiling showed relatively higher levels of glutamine, arginine and lysine in embryogenic callus than in dry and watery calli, while shoot base tissue showed an intermediate level of primary metabolites. For the five secondary metabolites analyzed (ie. panduratin, pinocembrin, pinostrobin, cardamonin and alpinetin), shoot base had the highest concentrations, followed by watery, dry and embryogenic calli. Furthermore, intracellular auxin levels were found to decrease from dry to watery calli, followed by shoot base and finally embryogenic calli. Our morphological observations showed the presence of fibrils on the cell surface of embryogenic callus while diphenylboric acid 2-aminoethylester staining indicated the presence of flavonoids in both dry and embryogenic calli. Periodic acid-Schiff staining showed that shoot base and dry and embryogenic calli contained starch reserves while none were found in watery callus. This study identified several primary metabolites that could be used as markers of embryogenic cells in B. rotunda, while secondary metabolite analysis indicated that biosynthesis pathways of these important metabolites may not be active in callus and embryogenic tissue.

The Application of Ultra-High-Performance Liquid Chromatography Coupled with a LTQ-Orbitrap Mass Technique to Reveal the Dynamic Accumulation of Secondary Metabolites in Licorice under ABA Stress.

PubMed

Li, Da; Xu, Guojie; Ren, Guangxi; Sun, Yufeng; Huang, Ying; Liu, Chunsheng

2017-10-20

The traditional medicine licorice is the most widely consumed herbal product in the world. Although much research work on studying the changes in the active compounds of licorice has been reported, there are still many areas, such as the dynamic accumulation of secondary metabolites in licorice, that need to be further studied. In this study, the secondary metabolites from licorice under two different methods of stress were investigated by ultra-high-performance liquid chromatography coupled with hybrid linear ion trap-Orbitrap mass spectrometry (UHPLC-LTQ-Orbitrap-MS). A complex continuous coordination of flavonoids and triterpenoids in a network was modulated by different methods of stress during growth. The results showed that a total of 51 secondary metabolites were identified in licorice under ABA stress. The partial least squares-discriminate analysis (PLS-DA) revealed the distinction of obvious compounds among stress-specific districts relative to ABA stress. The targeted results showed that there were significant differences in the accumulation patterns of the deeply targeted 41 flavonoids and 10 triterpenoids compounds by PCA and PLS-DA analyses. To survey the effects of flavonoid and triterpenoid metabolism under ABA stress, we inspected the stress-specific metabolic changes. Our study testified that the majority of flavonoids and triterpenoids were elevated in licorice under ABA stress, while the signature metabolite affecting the dynamic accumulation of secondary metabolites was detected. Taken together, our results suggest that ABA-specific metabolite profiling dynamically changed in terms of the biosynthesis of flavonoids and triterpenoids, which may offer new trains of thought on the regular pattern of dynamic accumulation of secondary metabolites in licorice at the metabolite level. Our results also provide a reference for clinical applications and directional planting and licorice breeding.

Penicillium spp.: prolific producer for harnessing cytotoxic secondary metabolites.

PubMed

Koul, Mytre; Singh, Shashank

2017-01-01

Secondary metabolites from fungal endophytes have become an interesting, attractive, and alternative source for novel pharmaceuticals. Several novel compounds with diversified chemical structures have been isolated from endophytic fungi. The genus Penicillium has been exploited worldwide for its biosynthetic potential for producing highly versatile cytotoxic secondary metabolites. Many of the compounds isolated from various species of the genus Penicillium have shown promising in-vitro as well as in-vivo growth-inhibitory properties against different human cancers. Thus, in relation to this genus, Penicillium represents the most dependable source of cytotoxic compounds with potential applications as leads for anticancer drugs. This review outlines endophytic secondary metabolites from the genus Penicillium with a relevant role as cytotoxic agents.

In Vivo and Real-time Monitoring of Secondary Metabolites of Living Organisms by Mass Spectrometry

NASA Astrophysics Data System (ADS)

Hu, Bin; Wang, Lei; Ye, Wen-Cai; Yao, Zhong-Ping

2013-07-01

Secondary metabolites are compounds that are important for the survival and propagation of animals and plants. Our current understanding on the roles and secretion mechanism of secondary metabolites is limited by the existing techniques that typically cannot provide transient and dynamic information about the metabolic processes. In this manuscript, by detecting venoms secreted by living scorpion and toad upon attack and variation of alkaloids in living Catharanthus roseus upon stimulation, which represent three different sampling methods for living organisms, we demonstrated that in vivo and real-time monitoring of secondary metabolites released from living animals and plants could be readily achieved by using field-induced direct ionization mass spectrometry.

Cellular compartmentalization of secondary metabolism

PubMed Central

Kistler, H. Corby; Broz, Karen

2015-01-01

Fungal secondary metabolism is often considered apart from the essential housekeeping functions of the cell. However, there are clear links between fundamental cellular metabolism and the biochemical pathways leading to secondary metabolite synthesis. Besides utilizing key biochemical precursors shared with the most essential processes of the cell (e.g., amino acids, acetyl CoA, NADPH), enzymes for secondary metabolite synthesis are compartmentalized at conserved subcellular sites that position pathway enzymes to use these common biochemical precursors. Co-compartmentalization of secondary metabolism pathway enzymes also may function to channel precursors, promote pathway efficiency and sequester pathway intermediates and products from the rest of the cell. In this review we discuss the compartmentalization of three well-studied fungal secondary metabolite biosynthetic pathways for penicillin G, aflatoxin and deoxynivalenol, and summarize evidence used to infer subcellular localization. We also discuss how these metabolites potentially are trafficked within the cell and may be exported. PMID:25709603

A comparative study of conventional and supercritical fluid extraction methods for the recovery of secondary metabolites from Syzygium campanulatum Korth.

PubMed

Memon, Abdul Hakeem; Hamil, Mohammad Shahrul Ridzuan; Laghari, Madeeha; Rithwan, Fahim; Zhari, Salman; Saeed, Mohammed Ali Ahmed; Ismail, Zhari; Majid, Amin Malik Shah Abdul

2016-09-01

Syzygium campanulatum Korth is a plant, which is a rich source of secondary metabolites (especially flavanones, chalcone, and triterpenoids). In our present study, three conventional solvent extraction (CSE) techniques and supercritical fluid extraction (SFE) techniques were performed to achieve a maximum recovery of two flavanones, chalcone, and two triterpenoids from S. campanulatum leaves. Furthermore, a Box-Behnken design was constructed for the SFE technique using pressure, temperature, and particle size as independent variables, and yields of crude extract, individual and total secondary metabolites as the dependent variables. In the CSE procedure, twenty extracts were produced using ten different solvents and three techniques (maceration, soxhletion, and reflux). An enriched extract of five secondary metabolites was collected using n-hexane:methanol (1:1) soxhletion. Using food-grade ethanol as a modifier, the SFE methods produced a higher recovery (25.5%‒84.9%) of selected secondary metabolites as compared to the CSE techniques (0.92%‒66.00%).

A comparative study of conventional and supercritical fluid extraction methods for the recovery of secondary metabolites from Syzygium campanulatum Korth#

PubMed Central

Memon, Abdul Hakeem; Hamil, Mohammad Shahrul Ridzuan; Laghari, Madeeha; Rithwan, Fahim; Zhari, Salman; Saeed, Mohammed Ali Ahmed; Ismail, Zhari; Majid, Amin Malik Shah Abdul

2016-01-01

Syzygium campanulatum Korth is a plant, which is a rich source of secondary metabolites (especially flavanones, chalcone, and triterpenoids). In our present study, three conventional solvent extraction (CSE) techniques and supercritical fluid extraction (SFE) techniques were performed to achieve a maximum recovery of two flavanones, chalcone, and two triterpenoids from S. campanulatum leaves. Furthermore, a Box-Behnken design was constructed for the SFE technique using pressure, temperature, and particle size as independent variables, and yields of crude extract, individual and total secondary metabolites as the dependent variables. In the CSE procedure, twenty extracts were produced using ten different solvents and three techniques (maceration, soxhletion, and reflux). An enriched extract of five secondary metabolites was collected using n-hexane:methanol (1:1) soxhletion. Using food-grade ethanol as a modifier, the SFE methods produced a higher recovery (25.5%‒84.9%) of selected secondary metabolites as compared to the CSE techniques (0.92%‒66.00%). PMID:27604860

Diversity and Antimicrobial Activities of Actinobacteria Isolated from Tropical Mangrove Sediments in Malaysia

PubMed Central

Lee, Learn-Han; Zainal, Nurullhudda; Azman, Adzzie-Shazleen; Eng, Shu-Kee; Goh, Bey-Hing; Yin, Wai-Fong; Ab Mutalib, Nurul-Syakima; Chan, Kok-Gan

2014-01-01

The aim of this study was to isolate and identify Actinobacteria from Malaysia mangrove forest and screen them for production of antimicrobial secondary metabolites. Eighty-seven isolates were isolated from soil samples collected at 4 different sites. This is the first report to describe the isolation of Streptomyces, Mycobacterium, Leifsonia, Microbacterium, Sinomonas, Nocardia, Terrabacter, Streptacidiphilus, Micromonospora, Gordonia, and Nocardioides from mangrove in east coast of Malaysia. Of 87 isolates, at least 5 isolates are considered as putative novel taxa. Nine Streptomyces sp. isolates were producing potent antimicrobial secondary metabolites, indicating that Streptomyces isolates are providing high quality metabolites for drug discovery purposes. The discovery of a novel species, Streptomyces pluripotens sp. nov. MUSC 135T that produced potent secondary metabolites inhibiting the growth of MRSA, had provided promising metabolites for drug discovery research. The biosynthetic potential of 87 isolates was investigated by the detection of polyketide synthetase (PKS) and nonribosomal polyketide synthetase (NRPS) genes, the hallmarks of secondary metabolites production. Results showed that many isolates were positive for PKS-I (19.5%), PKS-II (42.5%), and NRPS (5.7%) genes, indicating that mangrove Actinobacteria have significant biosynthetic potential. Our results highlighted that mangrove environment represented a rich reservoir for isolation of Actinobacteria, which are potential sources for discovery of antimicrobial secondary metabolites. PMID:25162061

Diversity and antimicrobial activities of actinobacteria isolated from tropical mangrove sediments in Malaysia.

PubMed

Lee, Learn-Han; Zainal, Nurullhudda; Azman, Adzzie-Shazleen; Eng, Shu-Kee; Goh, Bey-Hing; Yin, Wai-Fong; Ab Mutalib, Nurul-Syakima; Chan, Kok-Gan

2014-01-01

The aim of this study was to isolate and identify Actinobacteria from Malaysia mangrove forest and screen them for production of antimicrobial secondary metabolites. Eighty-seven isolates were isolated from soil samples collected at 4 different sites. This is the first report to describe the isolation of Streptomyces, Mycobacterium, Leifsonia, Microbacterium, Sinomonas, Nocardia, Terrabacter, Streptacidiphilus, Micromonospora, Gordonia, and Nocardioides from mangrove in east coast of Malaysia. Of 87 isolates, at least 5 isolates are considered as putative novel taxa. Nine Streptomyces sp. isolates were producing potent antimicrobial secondary metabolites, indicating that Streptomyces isolates are providing high quality metabolites for drug discovery purposes. The discovery of a novel species, Streptomyces pluripotens sp. nov. MUSC 135(T) that produced potent secondary metabolites inhibiting the growth of MRSA, had provided promising metabolites for drug discovery research. The biosynthetic potential of 87 isolates was investigated by the detection of polyketide synthetase (PKS) and nonribosomal polyketide synthetase (NRPS) genes, the hallmarks of secondary metabolites production. Results showed that many isolates were positive for PKS-I (19.5%), PKS-II (42.5%), and NRPS (5.7%) genes, indicating that mangrove Actinobacteria have significant biosynthetic potential. Our results highlighted that mangrove environment represented a rich reservoir for isolation of Actinobacteria, which are potential sources for discovery of antimicrobial secondary metabolites.

Synergetic effects of 5-aminolevulinic acid and Ascophyllum nodosum seaweed extracts on Asparagus phenolics and stress related genes under saline irrigation.

PubMed

Al-Ghamdi, Abdullah A; Elansary, Hosam O

2018-06-09

Salinity is one of the major agricultural problems that may threat food security and limit the agricultural lands expansion worldwide. Exploring novel tools controlling saline conditions and increase valuable secondary metabolites in the horticultural crops might have outstanding results that serve humanity in the current century. The current study explores the effects of weekly seaweed extracts (7 mL   L -1 ) and/or 5-aminolevulinic acid (3, 5 and 10 ppm) sprays on Asparagus aethiopicus plants subjected to saline stress conditions (2000 and 4000 ppm) for 6 weeks in two consecutive seasons of 2016 and 2017. Under saline conditions, there were stimulatory synergetic effects of seaweed extracts (SWE) and 5-aminolevulinic acid (ALA) on branch length and number of treated plants. Similar increases were also found in fresh and the dry weight of treated plants compared to control. These morphological improvements associated with increased accumulation of specific phenols (robinin, rutin, apigein, chlorogenic acid and caffeic acid) as revealed by High-Performance Liquid Chromatography with Diode-Array Detection (HPLC-DAD). There were increases in the antioxidant activities of leaf extracts, chlorophyll content and sugars and proline accumulation. The transpiration and photosynthetic rates as well as the stomatal conductance were enhanced. The morphological and physiological improvements associated with increased expression of several genes responsible for water management (ANN1, ANN2 and PIP1), secondary metabolite production (P5CS1 and CHS) and antioxidants accumulation (APX1 and GPX3) in plants. Our findings indicate that SWE + ALA had stimulatory synergetic effects on the growth and secondary metabolites of A. aethiopicus subjected to saline conditions. Several mechanisms are involved in such effects including gas exchange control, sugar buildup, increasing non-enzymatic and enzymatic antioxidants control of reactive oxygen species accumulation as well as transcriptional and metabolic regulation of environmental stress. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Microbial secondary metabolites in school buildings inspected for moisture damage in Finland, The Netherlands and Spain.

PubMed

Peitzsch, Mirko; Sulyok, Michael; Täubel, Martin; Vishwanath, Vinay; Krop, Esmeralda; Borràs-Santos, Alicia; Hyvärinen, Anne; Nevalainen, Aino; Krska, Rudolf; Larsson, Lennart

2012-08-01

Secondary metabolites produced by fungi and bacteria are among the potential agents that contribute to adverse health effects observed in occupants of buildings affected by moisture damage, dampness and associated microbial growth. However, few attempts have been made to assess the occurrence of these compounds in relation to moisture damage and dampness in buildings. This study conducted in the context of the HITEA project (Health Effects of Indoor Pollutants: Integrating microbial, toxicological and epidemiological approaches) aimed at providing systematic information on the prevalence of microbial secondary metabolites in a large number of school buildings in three European countries, considering both buildings with and without moisture damage and/or dampness observations. In order to address the multitude and diversity of secondary metabolites a large number of more than 180 analytes was targeted in settled dust and surface swab samples using liquid chromatography/mass spectrometry (LC/MS) based methodology. While 42%, 58% and 44% of all samples collected in Spanish, Dutch and Finnish schools, respectively, were positive for at least one of the metabolites analyzed, frequency of detection for the individual microbial secondary metabolites - with the exceptions of emodin, certain enniatins and physcion - was low, typically in the range of and below 10% of positive samples. In total, 30 different fungal and bacterial secondary metabolites were found in the samples. Some differences in the metabolite profiles were observed between countries and between index and reference school buildings. A major finding in this study was that settled dust derived from moisture damaged, damp schools contained larger numbers of microbial secondary metabolites at higher levels compared to respective dust samples from schools not affected by moisture damage and dampness. This observation was true for schools in each of the three countries, but became statistically significant only when combining schools from all countries and thus increasing the sample number in the statistical analyses.

Advances in engineered microorganisms for improving metabolic conversion via microgravity effects.

PubMed

Huangfu, Jie; Zhang, Genlin; Li, Jun; Li, Chun

2015-01-01

As an extreme and unique environment, microgravity has significant effects on microbial cellular processes, such as cell growth, gene expression, natural pathways and biotechnological products. Application of microgravity effects to identify the regulatory elements in reengineering microbial hosts will draw much more attention in further research. In this commentary, we discuss the microgravity effects in engineered microorganisms for improving metabolic conversion, including cell growth kinetics, antimicrobial susceptibility, resistance to stresses, secondary metabolites production, recombinant protein production and enzyme activity, as well as gene expression changes. Application of microgravity effects in engineered microorganisms could provide valuable platform for innovative approaches in bioprocessing technology to largely improve the metabolic conversion efficacy of biopharmaceutical products.

Identification and functional analysis of the aspergillic acid gene cluster in Aspergillus flavus

USDA-ARS?s Scientific Manuscript database

Aspergillus flavus can colonize important food staples and produces aflatoxins, toxic and carcinogenic secondary metabolites. In silico analysis of the A. flavus genome revealed 56 gene clusters encoding for secondary metabolites. How these many of these metabolites affect fungal development, surviv...

Secretion systems for secondary metabolites: how producer cells send out messages of intercellular communication.

PubMed

Martín, Juan F; Casqueiro, Javier; Liras, Paloma

2005-06-01

Many secondary metabolites (e.g. antibiotics and mycotoxins) are toxic to the microorganisms that produce them. The clusters of genes that are responsible for the biosynthesis of secondary metabolites frequently contain genes for resistance to these toxic metabolites, such as different types of multiple drug resistance systems, to avoid suicide of the producer strains. Recently there has been research into the efflux systems of secondary metabolites in bacteria and in filamentous fungi, such as the large number of ATP-binding cassette transporters found in antibiotic-producing Streptomyces species and that are involved in penicillin secretion in Penicillium chrysogenum. A different group of efflux systems, the major facilitator superfamily exporters, occur very frequently in a variety of bacteria that produce pigments or antibiotics (e.g. the cephamycin and thienamycin producers) and in filamentous fungi that produce mycotoxins. Such efflux systems include the CefT exporters that mediate cephalosporin secretion in Acremonium chrysogenum. The evolutionary origin of these efflux systems and their relationship with current resistance determinants in pathogenic bacteria has been analyzed. Genetic improvement of the secretion systems of secondary metabolites in the producer strain has important industrial applications.

Yield improvement strategies for the production of secondary metabolites in plant tissue culture: silymarin from Silybum marianum tissue culture.

PubMed

AbouZid, S

2014-01-01

Plant cell culture can be a potential source for the production of important secondary metabolites. This technology bears many advantages over conventional agricultural methods. The main problem to arrive at a cost-effective process is the low productivity. This is mainly due to lack of differentiation in the cultured cells. Many approaches have been used to maximise the yield of secondary metabolites produced by cultured plant cells. Among these approaches: choosing a plant with a high biosynthetic capacity, obtaining efficient cell line for growth and production of metabolite of interest, manipulating culture conditions, elicitation, metabolic engineering and organ culture. This article gives an overview of the various approaches used to maximise the production of pharmaceutically important secondary metabolites in plant cell cultures. Examples of using these different approaches are shown for the production of silymarin from Silybum marianum tissue culture.

Complete genome sequence of Streptomyces venezuelae ATCC 15439, a promising cell factory for production of secondary metabolites.

PubMed

Song, Ju Yeon; Yoo, Young Ji; Lim, Si-Kyu; Cha, Sun Ho; Kim, Ji-Eun; Roe, Jung-Hye; Kim, Jihyun F; Yoon, Yeo Joon

2016-02-10

Streptomyces venezuelae ATCC 15439, which produces 12- and 14-membered ring macrolide antibiotics, is a platform strain for heterologous expression of secondary metabolites. Its 9.05-Mb genome sequence revealed an abundance of genes involved in the biosynthesis of secondary metabolites and their precursors, which should be useful for the production of bioactive compounds. Copyright © 2015 Elsevier B.V. All rights reserved.

Microbial production of isoquinoline alkaloids as plant secondary metabolites based on metabolic engineering research.

PubMed

Sato, Fumihiko; Kumagai, Hidehiko

2013-01-01

Plants produce a variety of secondary metabolites that possess strong physiological activities. Unfortunately, however, their production can suffer from a variety of serious problems, including low levels of productivity and heterogeneous quality, as well as difficulty in raw material supply. In contrast, microorganisms can be used to produce their primary and some of their secondary metabolites in a controlled environment, thus assuring high levels of efficiency and uniform quality. In an attempt to overcome the problems associated with secondary metabolite production in plants, we developed a microbial platform for the production of plant isoquinoline alkaloids involving the unification of the microbial and plant metabolic pathways into a single system. The potential applications of this system have also been discussed.

Microbial production of isoquinoline alkaloids as plant secondary metabolites based on metabolic engineering research

PubMed Central

SATO, Fumihiko; KUMAGAI, Hidehiko

2013-01-01

Plants produce a variety of secondary metabolites that possess strong physiological activities. Unfortunately, however, their production can suffer from a variety of serious problems, including low levels of productivity and heterogeneous quality, as well as difficulty in raw material supply. In contrast, microorganisms can be used to produce their primary and some of their secondary metabolites in a controlled environment, thus assuring high levels of efficiency and uniform quality. In an attempt to overcome the problems associated with secondary metabolite production in plants, we developed a microbial platform for the production of plant isoquinoline alkaloids involving the unification of the microbial and plant metabolic pathways into a single system. The potential applications of this system have also been discussed. PMID:23666088

Identification, quantification, spatiotemporal distribution and genetic variation of major latex secondary metabolites in the common dandelion (Taraxacum officinale agg.).

PubMed

Huber, Meret; Triebwasser-Freese, Daniella; Reichelt, Michael; Heiling, Sven; Paetz, Christian; Chandran, Jima N; Bartram, Stefan; Schneider, Bernd; Gershenzon, Jonathan; Erb, Matthias

2015-07-01

The secondary metabolites in the roots, leaves and flowers of the common dandelion (Taraxacum officinale agg.) have been studied in detail. However, little is known about the specific constituents of the plant's highly specialized laticifer cells. Using a combination of liquid and gas chromatography, mass spectrometry and nuclear magnetic resonance spectrometry, we identified and quantified the major secondary metabolites in the latex of different organs across different growth stages in three genotypes, and tested the activity of the metabolites against the generalist root herbivore Diabrotica balteata. We found that common dandelion latex is dominated by three classes of secondary metabolites: phenolic inositol esters (PIEs), triterpene acetates (TritAc) and the sesquiterpene lactone taraxinic acid β-D-glucopyranosyl ester (TA-G). Purification and absolute quantification revealed concentrations in the upper mgg(-1) range for all compound classes with up to 6% PIEs, 5% TritAc and 7% TA-G per gram latex fresh weight. Contrary to typical secondary metabolite patterns, concentrations of all three classes increased with plant age. The highest concentrations were measured in the main root. PIE profiles differed both quantitatively and qualitatively between plant genotypes, whereas TritAc and TA-G differed only quantitatively. Metabolite concentrations were positively correlated within and between the different compound classes, indicating tight biosynthetic co-regulation. Latex metabolite extracts strongly repelled D. balteata larvae, suggesting that the latex constituents are biologically active. Copyright © 2015 Elsevier Ltd. All rights reserved.

Dose-dependent effects of nectar alkaloids in a montane plant-pollinator community

USDA-ARS?s Scientific Manuscript database

Although secondary metabolites are prevalent in floral nectar, the ecological consequences for pollinators and pollination remain relatively unexplored. While often deterrent to pollinators at high concentrations, secondary metabolite concentrations in nectar tend to be much lower than secondary met...

Using Molecular Networking for Microbial Secondary Metabolite Bioprospecting.

PubMed

Purves, Kevin; Macintyre, Lynsey; Brennan, Debra; Hreggviðsson, Guðmundur Ó; Kuttner, Eva; Ásgeirsdóttir, Margrét E; Young, Louise C; Green, David H; Edrada-Ebel, Ruangelie; Duncan, Katherine R

2016-01-08

The oceans represent an understudied resource for the isolation of bacteria with the potential to produce novel secondary metabolites. In particular, actinomyces are well known to produce chemically diverse metabolites with a wide range of biological activities. This study characterised spore-forming bacteria from both Scottish and Antarctic sediments to assess the influence of isolation location on secondary metabolite production. Due to the selective isolation method used, all 85 isolates belonged to the phyla Firmicutes and Actinobacteria, with the majority of isolates belonging to the genera Bacillus and Streptomyces. Based on morphology, thirty-eight isolates were chosen for chemical investigation. Molecular networking based on chemical profiles (HR-MS/MS) of fermentation extracts was used to compare complex metabolite extracts. The results revealed 40% and 42% of parent ions were produced by Antarctic and Scottish isolated bacteria, respectively, and only 8% of networked metabolites were shared between these locations, implying a high degree of biogeographic influence upon secondary metabolite production. The resulting molecular network contained over 3500 parent ions with a mass range of m/z 149-2558 illustrating the wealth of metabolites produced. Furthermore, seven fermentation extracts showed bioactivity against epithelial colon adenocarcinoma cells, demonstrating the potential for the discovery of novel bioactive compounds from these understudied locations.

Using Molecular Networking for Microbial Secondary Metabolite Bioprospecting

PubMed Central

Purves, Kevin; Macintyre, Lynsey; Brennan, Debra; Hreggviðsson, Guðmundur Ó.; Kuttner, Eva; Ásgeirsdóttir, Margrét E.; Young, Louise C.; Green, David H.; Edrada-Ebel, Ruangelie; Duncan, Katherine R.

2016-01-01

The oceans represent an understudied resource for the isolation of bacteria with the potential to produce novel secondary metabolites. In particular, actinomyces are well known to produce chemically diverse metabolites with a wide range of biological activities. This study characterised spore-forming bacteria from both Scottish and Antarctic sediments to assess the influence of isolation location on secondary metabolite production. Due to the selective isolation method used, all 85 isolates belonged to the phyla Firmicutes and Actinobacteria, with the majority of isolates belonging to the genera Bacillus and Streptomyces. Based on morphology, thirty-eight isolates were chosen for chemical investigation. Molecular networking based on chemical profiles (HR-MS/MS) of fermentation extracts was used to compare complex metabolite extracts. The results revealed 40% and 42% of parent ions were produced by Antarctic and Scottish isolated bacteria, respectively, and only 8% of networked metabolites were shared between these locations, implying a high degree of biogeographic influence upon secondary metabolite production. The resulting molecular network contained over 3500 parent ions with a mass range of m/z 149–2558 illustrating the wealth of metabolites produced. Furthermore, seven fermentation extracts showed bioactivity against epithelial colon adenocarcinoma cells, demonstrating the potential for the discovery of novel bioactive compounds from these understudied locations. PMID:26761036

antiSMASH: rapid identification, annotation and analysis of secondary metabolite biosynthesis gene clusters in bacterial and fungal genome sequences.

PubMed

Medema, Marnix H; Blin, Kai; Cimermancic, Peter; de Jager, Victor; Zakrzewski, Piotr; Fischbach, Michael A; Weber, Tilmann; Takano, Eriko; Breitling, Rainer

2011-07-01

Bacterial and fungal secondary metabolism is a rich source of novel bioactive compounds with potential pharmaceutical applications as antibiotics, anti-tumor drugs or cholesterol-lowering drugs. To find new drug candidates, microbiologists are increasingly relying on sequencing genomes of a wide variety of microbes. However, rapidly and reliably pinpointing all the potential gene clusters for secondary metabolites in dozens of newly sequenced genomes has been extremely challenging, due to their biochemical heterogeneity, the presence of unknown enzymes and the dispersed nature of the necessary specialized bioinformatics tools and resources. Here, we present antiSMASH (antibiotics & Secondary Metabolite Analysis Shell), the first comprehensive pipeline capable of identifying biosynthetic loci covering the whole range of known secondary metabolite compound classes (polyketides, non-ribosomal peptides, terpenes, aminoglycosides, aminocoumarins, indolocarbazoles, lantibiotics, bacteriocins, nucleosides, beta-lactams, butyrolactones, siderophores, melanins and others). It aligns the identified regions at the gene cluster level to their nearest relatives from a database containing all other known gene clusters, and integrates or cross-links all previously available secondary-metabolite specific gene analysis methods in one interactive view. antiSMASH is available at http://antismash.secondarymetabolites.org.

Secondary metabolites from Ganoderma.

PubMed

Baby, Sabulal; Johnson, Anil John; Govindan, Balaji

2015-06-01

Ganoderma is a genus of medicinal mushrooms. This review deals with secondary metabolites isolated from Ganoderma and their biological significance. Phytochemical studies over the last 40years led to the isolation of 431 secondary metabolites from various Ganoderma species. The major secondary compounds isolated are (a) C30 lanostanes (ganoderic acids), (b) C30 lanostanes (aldehydes, alcohols, esters, glycosides, lactones, ketones), (c) C27 lanostanes (lucidenic acids), (d) C27 lanostanes (alcohols, lactones, esters), (e) C24, C25 lanostanes (f) C30 pentacyclic triterpenes, (g) meroterpenoids, (h) farnesyl hydroquinones (meroterpenoids), (i) C15 sesquiterpenoids, (j) steroids, (k) alkaloids, (l) prenyl hydroquinone (m) benzofurans, (n) benzopyran-4-one derivatives and (o) benzenoid derivatives. Ganoderma lucidum is the species extensively studied for its secondary metabolites and biological activities. Ganoderma applanatum, Ganoderma colossum, Ganoderma sinense, Ganoderma cochlear, Ganoderma tsugae, Ganoderma amboinense, Ganoderma orbiforme, Ganoderma resinaceum, Ganoderma hainanense, Ganoderma concinna, Ganoderma pfeifferi, Ganoderma neo-japonicum, Ganoderma tropicum, Ganoderma australe, Ganoderma carnosum, Ganoderma fornicatum, Ganoderma lipsiense (synonym G. applanatum), Ganoderma mastoporum, Ganoderma theaecolum, Ganoderma boninense, Ganoderma capense and Ganoderma annulare are the other Ganoderma species subjected to phytochemical studies. Further phytochemical studies on Ganoderma could lead to the discovery of hitherto unknown biologically active secondary metabolites. Copyright © 2015 Elsevier Ltd. All rights reserved.

An Invasive Plant Promotes Its Arbuscular Mycorrhizal Symbioses and Competitiveness through Its Secondary Metabolites: Indirect Evidence from Activated Carbon

PubMed Central

Yuan, Yongge; Tang, Jianjun; Leng, Dong; Hu, Shuijin; Yong, Jean W. H.; Chen, Xin

2014-01-01

Secondary metabolites released by invasive plants can increase their competitive ability by affecting native plants, herbivores, and pathogens at the invaded land. Whether these secondary metabolites affect the invasive plant itself, directly or indirectly through microorganisms, however, has not been well documented. Here we tested whether activated carbon (AC), a well-known absorbent for secondary metabolites, affect arbuscular mycorrhizal (AM) symbioses and competitive ability in an invasive plant. We conducted three experiments (experiments 1–3) with the invasive forb Solidago canadensis and the native Kummerowia striata. Experiment 1 determined whether AC altered soil properties, levels of the main secondary metabolites in the soil, plant growth, and AMF communities associated with S. canadensis and K. striata. Experiment 2 determined whether AC affected colonization of S. canadensis by five AMF, which were added to sterilized soil. Experiment 3 determined the competitive ability of S. canadensis in the presence and absence of AMF and AC. In experiment 1, AC greatly decreased the concentrations of the main secondary metabolites in soil, and the changes in concentrations were closely related with the changes of AMF in S. canadensis roots. In experiment 2, AC inhibited the AMF Glomus versiforme and G. geosporum but promoted G. mosseae and G. diaphanum in the soil and also in S. canadensis roots. In experiment 3, AC reduced S. canadensis competitive ability in the presence but not in the absence of AMF. Our results provided indirect evidence that the secondary metabolites (which can be absorbed by AC) of the invasive plant S. canadensis may promote S. canadensis competitiveness by enhancing its own AMF symbionts. PMID:24817325

An invasive plant promotes its arbuscular mycorrhizal symbioses and competitiveness through its secondary metabolites: indirect evidence from activated carbon.

PubMed

Yuan, Yongge; Tang, Jianjun; Leng, Dong; Hu, Shuijin; Yong, Jean W H; Chen, Xin

2014-01-01

Secondary metabolites released by invasive plants can increase their competitive ability by affecting native plants, herbivores, and pathogens at the invaded land. Whether these secondary metabolites affect the invasive plant itself, directly or indirectly through microorganisms, however, has not been well documented. Here we tested whether activated carbon (AC), a well-known absorbent for secondary metabolites, affect arbuscular mycorrhizal (AM) symbioses and competitive ability in an invasive plant. We conducted three experiments (experiments 1-3) with the invasive forb Solidago canadensis and the native Kummerowia striata. Experiment 1 determined whether AC altered soil properties, levels of the main secondary metabolites in the soil, plant growth, and AMF communities associated with S. canadensis and K. striata. Experiment 2 determined whether AC affected colonization of S. canadensis by five AMF, which were added to sterilized soil. Experiment 3 determined the competitive ability of S. canadensis in the presence and absence of AMF and AC. In experiment 1, AC greatly decreased the concentrations of the main secondary metabolites in soil, and the changes in concentrations were closely related with the changes of AMF in S. canadensis roots. In experiment 2, AC inhibited the AMF Glomus versiforme and G. geosporum but promoted G. mosseae and G. diaphanum in the soil and also in S. canadensis roots. In experiment 3, AC reduced S. canadensis competitive ability in the presence but not in the absence of AMF. Our results provided indirect evidence that the secondary metabolites (which can be absorbed by AC) of the invasive plant S. canadensis may promote S. canadensis competitiveness by enhancing its own AMF symbionts.

Genome sequence of an industrial microorganism Streptomyces avermitilis: deducing the ability of producing secondary metabolites.

PubMed

Omura, S; Ikeda, H; Ishikawa, J; Hanamoto, A; Takahashi, C; Shinose, M; Takahashi, Y; Horikawa, H; Nakazawa, H; Osonoe, T; Kikuchi, H; Shiba, T; Sakaki, Y; Hattori, M

2001-10-09

Streptomyces avermitilis is a soil bacterium that carries out not only a complex morphological differentiation but also the production of secondary metabolites, one of which, avermectin, is commercially important in human and veterinary medicine. The major interest in this genus Streptomyces is the diversity of its production of secondary metabolites as an industrial microorganism. A major factor in its prominence as a producer of the variety of secondary metabolites is its possession of several metabolic pathways for biosynthesis. Here we report sequence analysis of S. avermitilis, covering 99% of its genome. At least 8.7 million base pairs exist in the linear chromosome; this is the largest bacterial genome sequence, and it provides insights into the intrinsic diversity of the production of the secondary metabolites of Streptomyces. Twenty-five kinds of secondary metabolite gene clusters were found in the genome of S. avermitilis. Four of them are concerned with the biosyntheses of melanin pigments, in which two clusters encode tyrosinase and its cofactor, another two encode an ochronotic pigment derived from homogentiginic acid, and another polyketide-derived melanin. The gene clusters for carotenoid and siderophore biosyntheses are composed of seven and five genes, respectively. There are eight kinds of gene clusters for type-I polyketide compound biosyntheses, and two clusters are involved in the biosyntheses of type-II polyketide-derived compounds. Furthermore, a polyketide synthase that resembles phloroglucinol synthase was detected. Eight clusters are involved in the biosyntheses of peptide compounds that are synthesized by nonribosomal peptide synthetases. These secondary metabolite clusters are widely located in the genome but half of them are near both ends of the genome. The total length of these clusters occupies about 6.4% of the genome.

Species specificity of symbiosis and secondary metabolism in ascidians.

PubMed

Tianero, Ma Diarey B; Kwan, Jason C; Wyche, Thomas P; Presson, Angela P; Koch, Michael; Barrows, Louis R; Bugni, Tim S; Schmidt, Eric W

2015-03-01

Ascidians contain abundant, diverse secondary metabolites, which are thought to serve a defensive role and which have been applied to drug discovery. It is known that bacteria in symbiosis with ascidians produce several of these metabolites, but very little is known about factors governing these 'chemical symbioses'. To examine this phenomenon across a wide geographical and species scale, we performed bacterial and chemical analyses of 32 different ascidians, mostly from the didemnid family from Florida, Southern California and a broad expanse of the tropical Pacific Ocean. Bacterial diversity analysis showed that ascidian microbiomes are highly diverse, and this diversity does not correlate with geographical location or latitude. Within a subset of species, ascidian microbiomes are also stable over time (R=-0.037, P-value=0.499). Ascidian microbiomes and metabolomes contain species-specific and location-specific components. Location-specific bacteria are found in low abundance in the ascidians and mostly represent strains that are widespread. Location-specific metabolites consist largely of lipids, which may reflect differences in water temperature. By contrast, species-specific bacteria are mostly abundant sequenced components of the microbiomes and include secondary metabolite producers as major components. Species-specific chemicals are dominated by secondary metabolites. Together with previous analyses that focused on single ascidian species or symbiont type, these results reveal fundamental properties of secondary metabolic symbiosis. Different ascidian species have established associations with many different bacterial symbionts, including those known to produce toxic chemicals. This implies a strong selection for this property and the independent origin of secondary metabolite-based associations in different ascidian species. The analysis here streamlines the connection of secondary metabolite to producing bacterium, enabling further biological and biotechnological studies.

Sequential Metabolism of Secondary Alkyl Amines to Metabolic-Intermediate Complexes: Opposing Roles for the Secondary Hydroxylamine and Primary Amine Metabolites of Desipramine, (S)-Fluoxetine, and N-Desmethyldiltiazem

PubMed Central

Hanson, Kelsey L.; VandenBrink, Brooke M.; Babu, Kantipudi N.; Allen, Kyle E.; Nelson, Wendel L.

2010-01-01

Three secondary amines desipramine (DES), (S)-fluoxetine [(S)-FLX], and N-desmethyldiltiazem (MA) undergo N-hydroxylation to the corresponding secondary hydroxylamines [N-hydroxydesipramine, (S)-N-hydroxyfluoxetine, and N-hydroxy-N-desmethyldiltiazem] by cytochromes P450 2C11, 2C19, and 3A4, respectively. The expected primary amine products, N-desmethyldesipramine, (S)-norfluoxetine, and N,N-didesmethyldiltiazem, are also observed. The formation of metabolic-intermediate (MI) complexes from these substrates and metabolites was examined. In each example, the initial rates of MI complex accumulation followed the order secondary hydroxylamine > secondary amine ≫ primary amine, suggesting that the primary amine metabolites do not contribute to formation of MI complexes from these secondary amines. Furthermore, the primary amine metabolites, which accumulate in incubations of the secondary amines, inhibit MI complex formation. Mass balance studies provided estimates of the product ratios of N-dealkylation to N-hydroxylation. The ratios were 2.9 (DES-CYP2C11), 3.6 [(S)-FLX-CYP2C19], and 0.8 (MA-CYP3A4), indicating that secondary hydroxylamines are significant metabolites of the P450-mediated metabolism of secondary alkyl amines. Parallel studies with N-methyl-d3-desipramine and CYP2C11 demonstrated significant isotopically sensitive switching from N-demethylation to N-hydroxylation. These findings demonstrate that the major pathway to MI complex formation from these secondary amines arises from N-hydroxylation rather than N-dealkylation and that the primary amines are significant competitive inhibitors of MI complex formation. PMID:20200233

Sequential metabolism of secondary alkyl amines to metabolic-intermediate complexes: opposing roles for the secondary hydroxylamine and primary amine metabolites of desipramine, (s)-fluoxetine, and N-desmethyldiltiazem.

PubMed

Hanson, Kelsey L; VandenBrink, Brooke M; Babu, Kantipudi N; Allen, Kyle E; Nelson, Wendel L; Kunze, Kent L

2010-06-01

Three secondary amines desipramine (DES), (S)-fluoxetine [(S)-FLX], and N-desmethyldiltiazem (MA) undergo N-hydroxylation to the corresponding secondary hydroxylamines [N-hydroxydesipramine, (S)-N-hydroxyfluoxetine, and N-hydroxy-N-desmethyldiltiazem] by cytochromes P450 2C11, 2C19, and 3A4, respectively. The expected primary amine products, N-desmethyldesipramine, (S)-norfluoxetine, and N,N-didesmethyldiltiazem, are also observed. The formation of metabolic-intermediate (MI) complexes from these substrates and metabolites was examined. In each example, the initial rates of MI complex accumulation followed the order secondary hydroxylamine > secondary amine > primary amine, suggesting that the primary amine metabolites do not contribute to formation of MI complexes from these secondary amines. Furthermore, the primary amine metabolites, which accumulate in incubations of the secondary amines, inhibit MI complex formation. Mass balance studies provided estimates of the product ratios of N-dealkylation to N-hydroxylation. The ratios were 2.9 (DES-CYP2C11), 3.6 [(S)-FLX-CYP2C19], and 0.8 (MA-CYP3A4), indicating that secondary hydroxylamines are significant metabolites of the P450-mediated metabolism of secondary alkyl amines. Parallel studies with N-methyl-d(3)-desipramine and CYP2C11 demonstrated significant isotopically sensitive switching from N-demethylation to N-hydroxylation. These findings demonstrate that the major pathway to MI complex formation from these secondary amines arises from N-hydroxylation rather than N-dealkylation and that the primary amines are significant competitive inhibitors of MI complex formation.

Pharmaceutically active secondary metabolites of marine actinobacteria.

PubMed

Manivasagan, Panchanathan; Venkatesan, Jayachandran; Sivakumar, Kannan; Kim, Se-Kwon

2014-04-01

Marine actinobacteria are one of the most efficient groups of secondary metabolite producers and are very important from an industrial point of view. Many representatives of the order Actinomycetales are prolific producers of thousands of biologically active secondary metabolites. Actinobacteria from terrestrial sources have been studied and screened since the 1950s, for many important antibiotics, anticancer, antitumor and immunosuppressive agents. However, frequent rediscovery of the same compounds from the terrestrial actinobacteria has made them less attractive for screening programs in the recent years. At the same time, actinobacteria isolated from the marine environment have currently received considerable attention due to the structural diversity and unique biological activities of their secondary metabolites. They are efficient producers of new secondary metabolites that show a range of biological activities including antibacterial, antifungal, anticancer, antitumor, cytotoxic, cytostatic, anti-inflammatory, anti-parasitic, anti-malaria, antiviral, antioxidant, anti-angiogenesis, etc. In this review, an evaluation is made on the current status of research on marine actinobacteria yielding pharmaceutically active secondary metabolites. Bioactive compounds from marine actinobacteria possess distinct chemical structures that may form the basis for synthesis of new drugs that could be used to combat resistant pathogens. With the increasing advancement in science and technology, there would be a greater demand for new bioactive compounds synthesized by actinobacteria from various marine sources in future. Copyright © 2013 Elsevier GmbH. All rights reserved.

Marine sediment-derived Streptomyces bacteria from British Columbia, Canada are a promising microbiota resource for the discovery of antimicrobial natural products.

PubMed

Dalisay, Doralyn S; Williams, David E; Wang, Xiao Ling; Centko, Ryan; Chen, Jessie; Andersen, Raymond J

2013-01-01

Representatives of the genus Streptomyces from terrestrial sources have been the focus of intensive research for the last four decades because of their prolific production of chemically diverse and biologically important compounds. However, metabolite research from this ecological niche had declined significantly in the past years because of the rediscovery of the same bioactive compounds and redundancy of the sample strains. More recently, a new picture has begun to emerge in which marine-derived Streptomyces bacteria have become the latest hot spot as new source for unique and biologically active compounds. Here, we investigated the marine sediments collected in the temperate cold waters from British Columbia, Canada as a valuable source for new groups of marine-derived Streptomyces with antimicrobial activities. We performed culture dependent isolation from 49 marine sediments samples and obtained 186 Streptomyces isolates, 47 of which exhibited antimicrobial activities. Phylogenetic analyses of the active isolates resulted in the identification of four different clusters of bioactive Streptomyces including a cluster with isolates that appear to represent novel species. Moreover, we explored whether these marine-derived Streptomyces produce new secondary metabolites with antimicrobial properties. Chemical analyses revealed structurally diverse secondary metabolites, including four new antibacterial novobiocin analogues. We conducted structure-activity relationships (SAR) studies of these novobiocin analogues against methicillin-resistant Staphylococcus aureus (MRSA). In this study, we revealed the importance of carbamoyl and OMe moieties at positions 3" and 4" of novobiose as well as the hydrogen substituent at position 5 of hydroxybenzoate ring for the anti-MRSA activity. Changes in the substituents at these positions dramatically impede or completely eliminate the inhibitory activity of novobiocins against MRSA.

Transgenic hairy roots. recent trends and applications.

PubMed

Giri, A; Narasu, M L

2000-03-01

Agrobacterium rhizogenes causes hairy root disease in plants. The neoplastic roots produced by A. rhizogenes infection is characterized by high growth rate and genetic stability. These genetically transformed root cultures can produce higher levels of secondary metabolites or amounts comparable to that of intact plants. Hairy root cultures offer promise for production of valuable secondary metabolites in many plants. The main constraint for commercial exploitation of hairy root cultures is their scaling up, as there is a need for developing a specially designed bioreactor that permits the growth of interconnected tissues unevenly distributed throughout the vessel. Rheological characteristics of heterogeneous system should also be taken into consideration during mass scale culturing of hairy roots. Development of bioreactor models for hairy root cultures is still a recent phenomenon. It is also necessary to develop computer-aided models for different parameters such as oxygen consumption and excretion of product to the medium. Further, transformed roots are able to regenerate genetically stable plants as transgenics or clones. This property of rapid growth and high plantlet regeneration frequency allows clonal propagation of elite plants. In addition, the altered phenotype of hairy root regenerants (hairy root syndrome) is useful in plant breeding programs with plants of ornamental interest. In vitro transformation and regeneration from hairy roots facilitates application of biotechnology to tree species. The ability to manipulate trees at a cellular and molecular level shows great potential for clonal propagation and genetic improvement. Transgenic root system offers tremendous potential for introducing additional genes along with the Ri T-DNA genes for alteration of metabolic pathways and production of useful metabolites or compounds of interest. This article discusses various applications and perspectives of hairy root cultures and the recent progress achieved with respect to transformation of plants using A. rhizogenes.

Effect of viroid infection on the dynamics of phenolic metabolites in the apoplast of tomato

USDA-ARS?s Scientific Manuscript database

Plants are capable of producing a wide array of secondary metabolites which serve many functions, due to their bioactive, redox or structural properties. Subtle changes in the external or internal environment can cause significant changes in the array of secondary metabolites presented in the tissu...

Prototype of an intertwined secondary-metabolite supercluster

Treesearch

Phillipp Wiemann; Chun-Jun. Guo; Jonathan M. Palmer; Relebohile Sekonyela; Clay C.C. Wang; Nancy P. Keller

2013-01-01

The hallmark trait of fungal secondary-metabolite gene clusters is well established, consisting of contiguous enzymatic and often regulatory gene(s) devoted to the production of a metabolite of a specific chemical class. Unexpectedly, we have found a deviation from this motif in a subtelomeric region of Aspergillus fumigatus. This region, under the...

Effects of the microbial secondary metabolite benzothiazole on the nutritional physiology and enzyme activities of Bradysia odoriphaga (Diptera: Sciaridae).

PubMed

Zhao, Yunhe; Xu, Chunmei; Wang, Qiuhong; Wei, Yan; Liu, Feng; Xu, Shuangyu; Zhang, Zhengqun; Mu, Wei

2016-05-01

Bradysia odoriphaga (Diptera: Sciaridae) is the major pest that damages Chinese chive production. As a volatile compound derived from microbial secondary metabolites, benzothiazole has been determined to possess fumigant activity against B. odoriphaga. However, the mechanism of action of benzothiazole is not well understood. In the present study, fourth-instar larvae of B. odoriphaga were exposed to LC10 and LC30 of benzothiazole. Sublethal concentrations (LC10 and LC30) of benzothiazole significantly reduced the food consumption of the larvae on the second day after treatment (2 DAT). However, there were no significant changes in pupal weight among the different treatments. We also measured the protein, lipid, carbohydrate, and trehalose contents and the digestive enzyme activities of the larvae, and the results suggest that benzothiazole reduced the nutrient accumulation and decreased the digestive enzyme activities of B. odoriphaga. In addition, the activity of glutathione S-transferase was significantly decreased at 6h after treatment with benzothiazole, whereas general esterase activities were significantly increased at 6 and 24h after treatment. The results of this study indicate that benzothiazole interferes in the normal food consumption and digestion process by decreasing the activities of digestive enzymes. These results provide valuable information for understanding the toxicity of benzothiazole and for exploring volatile compound for the control of this pest. Copyright © 2015. Published by Elsevier Inc.

Aspergillus oryzae-based cell factory for direct kojic acid production from cellulose.

PubMed

Yamada, Ryosuke; Yoshie, Toshihide; Wakai, Satoshi; Asai-Nakashima, Nanami; Okazaki, Fumiyoshi; Ogino, Chiaki; Hisada, Hiromoto; Tsutsumi, Hiroko; Hata, Yoji; Kondo, Akihiko

2014-05-18

Kojic acid (5-Hydroxy-2-(hydroxymethyl)-4-pyrone) is one of the major secondary metabolites in Aspergillus oryzae. It is widely used in food, pharmaceuticals, and cosmetics. The production cost, however, is too high for its use in many applications. Thus, an efficient and cost-effective kojic acid production process would be valuable. However, little is known about the complete set of genes for kojic acid production. Currently, kojic acid is produced from glucose. The efficient production of kojic acid using cellulose as an inexpensive substrate would help establish cost-effective kojic acid production. A kojic acid transcription factor gene over-expressing the A. oryzae strain was constructed. Three genes related to kojic acid production in this strain were transcribed in higher amounts than those found in the wild-type strain. This strain produced 26.4 g/L kojic acid from 80 g/L glucose. Furthermore, this strain was transformed with plasmid harboring 3 cellulase genes. The resultant A. oryzae strain successfully produced 0.18 g/L of kojic acid in 6 days of fermentation from the phosphoric acid swollen cellulose. Kojic acid was produced directly from cellulose material using genetically engineered A. oryzae. Because A. oryzae has efficient protein secretion ability and secondary metabolite productivity, an A. oryzae-based cell factory could be a platform for the production of various kinds of bio-based chemicals.

Aspergillus oryzae-based cell factory for direct kojic acid production from cellulose

PubMed Central

2014-01-01

Background Kojic acid (5-Hydroxy-2-(hydroxymethyl)-4-pyrone) is one of the major secondary metabolites in Aspergillus oryzae. It is widely used in food, pharmaceuticals, and cosmetics. The production cost, however, is too high for its use in many applications. Thus, an efficient and cost-effective kojic acid production process would be valuable. However, little is known about the complete set of genes for kojic acid production. Currently, kojic acid is produced from glucose. The efficient production of kojic acid using cellulose as an inexpensive substrate would help establish cost-effective kojic acid production. Results A kojic acid transcription factor gene over-expressing the A. oryzae strain was constructed. Three genes related to kojic acid production in this strain were transcribed in higher amounts than those found in the wild-type strain. This strain produced 26.4 g/L kojic acid from 80 g/L glucose. Furthermore, this strain was transformed with plasmid harboring 3 cellulase genes. The resultant A. oryzae strain successfully produced 0.18 g/L of kojic acid in 6 days of fermentation from the phosphoric acid swollen cellulose. Conclusions Kojic acid was produced directly from cellulose material using genetically engineered A. oryzae. Because A. oryzae has efficient protein secretion ability and secondary metabolite productivity, an A. oryzae-based cell factory could be a platform for the production of various kinds of bio-based chemicals. PMID:24885968

Chemical and bioactive diversities of the genus Chaetomium secondary metabolites.

PubMed

Zhang, Q; Li, H-Q; Zong, S-C; Gao, J-M; Zhang, A-L

2012-02-01

The genus Chaetomium fungi are considered to be a rich source of novel and bioactive secondary metabolites of great importance. Up till now, a variety of more than 200 secondary metabolites belonging to diverse structural types of chaetoglobosins, epipolythiodioxopiperazines, azaphilones, xanthones, anthraquinones, chromones, depsidones, terpenoids, and steroids have been discovered. Most of these fungal metabolites exhibited antitumor, cytotoxic, antimalarial, enzyme inhibitory, antibiotic, and other activities. This review covers the extraction, structure elucidation, structural diversity, and biological activities of natural products isolated from about 30 fungi associated with marine- and terrestrial- origins, and highlights some bioactive compounds as well as their mechanisms of action and structure-activity relationships.

Assembly and features of secondary metabolite biosynthetic gene clusters in Streptomyces ansochromogenes.

PubMed

Zhong, Xingyu; Tian, Yuqing; Niu, Guoqing; Tan, Huarong

2013-07-01

A draft genome sequence of Streptomyces ansochromogenes 7100 was generated using 454 sequencing technology. In combination with local BLAST searches and gap filling techniques, a comprehensive antiSMASH-based method was adopted to assemble the secondary metabolite biosynthetic gene clusters in the draft genome of S. ansochromogenes. A total of at least 35 putative gene clusters were identified and assembled. Transcriptional analysis showed that 20 of the 35 gene clusters were expressed in either or all of the three different media tested, whereas the other 15 gene clusters were silent in all three different media. This study provides a comprehensive method to identify and assemble secondary metabolite biosynthetic gene clusters in draft genomes of Streptomyces, and will significantly promote functional studies of these secondary metabolite biosynthetic gene clusters.

Cellular Immune Reactions of the Sunn Pest, Eurygaster integriceps, to the Entomopathogenic Fungus, Beauveria bassiana and Its Secondary Metabolites

PubMed Central

Zibaee, Arash; Bandani, Ali Reza; Talaei-Hassanlouei, Reza; Malagoli, Davide

2011-01-01

In this study, five morphological types of circulating hemocytes were recognized in the hemolymph of the adult sunn pest, Eurygaster integriceps Puton (Hemiptera: Scutelleridae), namely prohemocytes, plasmatocytes, granulocytes, adipohemocytes, and oenocytoids. The effects of the secondary metabolites of the entomopathogenic fungus Beauveria bassiana on cellular immune defenses of Eurygaster integriceps were investigated. The results showed that the fungal secondary metabolites inhibited phagocytic activity of E. integriceps hemocytes and hampered nodule formation. A reduction of phenoloxidase activity was also observed. The data suggest that B. bassiana produce secondary metabolites that disable several immune mechanisms allowing the fungus to overcome and then kill its host. This characteristic makes B. bassiana a promising model for biological control of insect pests such as E. integriceps. PMID:22233481

Activation of the dormant secondary metabolite production by introducing gentamicin-resistance in a marine-derived Penicillium purpurogenum G59.

PubMed

Chai, Yun-Jing; Cui, Cheng-Bin; Li, Chang-Wei; Wu, Chang-Jing; Tian, Cong-Kui; Hua, Wei

2012-03-01

A new approach to activate silent gene clusters for dormant secondary metabolite production has been developed by introducing gentamicin-resistance to an originally inactive, marine-derived fungal strain Penicillium purpurogenum G59. Upon treatment of the G59 spores with a high concentration of gentamicin in aqueous DMSO, a total of 181 mutants were obtained by single colony isolation. In contrast to the strain G59, the EtOAc extracts of nine mutant cultures showed inhibitory effects on K562 cells, indicating that the nine mutants had acquired capability to produce antitumor metabolites. This was evidenced by TLC and HPLC analysis of EtOAc extracts of G59 and the nine mutants. Further isolation and characterization demonstrated that four antitumor secondary metabolites, janthinone (1), fructigenine A (2), aspterric acid methyl ester (3) and citrinin (4), were newly produced by mutant 5-1-4 compared to the parent strain G59, and which were also not found in the secondary metabolites of other Penicillium purpurogenum strains. However, Compounds 1-4 inhibited the proliferation of K562 cells with inhibition rates of 34.6% (1), 60.8% (2), 31.7% (3) and 67.1% (4) at 100 μg/mL, respectively. The present study demonstrated the effectiveness of a simple, yet practical approach to activate the production of dormant fungal secondary metabolites by introducing acquired resistance to aminoglycoside antibiotics, which could be applied to the studies for eliciting dormant metabolic potential of fungi to obtain cryptic secondary metabolites.

Activation of the Dormant Secondary Metabolite Production by Introducing Gentamicin-Resistance in a Marine-Derived Penicillium purpurogenum G59

PubMed Central

Chai, Yun-Jing; Cui, Cheng-Bin; Li, Chang-Wei; Wu, Chang-Jing; Tian, Cong-Kui; Hua, Wei

2012-01-01

A new approach to activate silent gene clusters for dormant secondary metabolite production has been developed by introducing gentamicin-resistance to an originally inactive, marine-derived fungal strain Penicillium purpurogenum G59. Upon treatment of the G59 spores with a high concentration of gentamicin in aqueous DMSO, a total of 181 mutants were obtained by single colony isolation. In contrast to the strain G59, the EtOAc extracts of nine mutant cultures showed inhibitory effects on K562 cells, indicating that the nine mutants had acquired capability to produce antitumor metabolites. This was evidenced by TLC and HPLC analysis of EtOAc extracts of G59 and the nine mutants. Further isolation and characterization demonstrated that four antitumor secondary metabolites, janthinone (1), fructigenine A (2), aspterric acid methyl ester (3) and citrinin (4), were newly produced by mutant 5-1-4 compared to the parent strain G59, and which were also not found in the secondary metabolites of other Penicillium purpurogenum strains. However, Compounds 1–4 inhibited the proliferation of K562 cells with inhibition rates of 34.6% (1), 60.8% (2), 31.7% (3) and 67.1% (4) at 100 μg/mL, respectively. The present study demonstrated the effectiveness of a simple, yet practical approach to activate the production of dormant fungal secondary metabolites by introducing acquired resistance to aminoglycoside antibiotics, which could be applied to the studies for eliciting dormant metabolic potential of fungi to obtain cryptic secondary metabolites. PMID:22611354

Combined mass spectrometry-based metabolite profiling of different pigmented rice (Oryza sativa L.) seeds and correlation with antioxidant activities.

PubMed

Kim, Ga Ryun; Jung, Eun Sung; Lee, Sarah; Lim, Sun-Hyung; Ha, Sun-Hwa; Lee, Choong Hwan

2014-09-29

Nine varieties of pigmented rice (Oryza sativa L.) seeds that were black, red, or white were used to perform metabolite profiling by using ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF-MS) and gas chromatography (GC) TOF-MS, to measure antioxidant activities. Clear grouping patterns determined by the color of the rice seeds were identified in principle component analysis (PCA) derived from UPLC-Q-TOF-MS. Cyanidin-3-glucoside, peonidin-3-glucoside, proanthocyanidin dimer, proanthocyanidin trimer, apigenin-6-C-glugosyl-8-C-arabiboside, tricin-O-rhamnoside-O-hexoside, and lipids were identified as significantly different secondary metabolites. In PCA score plots derived from GC-TOF-MS, Jakwangdo (JKD) and Ilpoom (IP) species were discriminated from the other rice seeds by PC1 and PC2. Valine, phenylalanine, adenosine, pyruvate, nicotinic acid, succinic acid, maleic acid, malonic acid, gluconic acid, xylose, fructose, glucose, maltose, and myo-inositol were significantly different primary metabolites in JKD species, while GABA, asparagine, xylitol, and sucrose were significantly distributed in IP species. Analysis of antioxidant activities revealed that black and red rice seeds had higher activity than white rice seeds. Cyanidin-3-glucoside, peonidin-3-glucoside, proanthocyanidin dimers, proanthocyanidin trimers, and catechin were highly correlated with antioxidant activities, and were more plentiful in black and red rice seeds. These results are expected to provide valuable information that could help improve and develop rice-breeding techniques.

Antimicrobial properties and the influence of temperature on secondary metabolite production in cold environment soil fungi

NASA Astrophysics Data System (ADS)

Yogabaanu, U.; Weber, Jean-Frederic Faizal; Convey, Peter; Rizman-Idid, Mohammed; Alias, Siti Aisyah

2017-12-01

The Arctic and Antarctic share environmental extremes. To survive in such environments, microbes such as soil fungi need to compete with or protect themselves effectively from other soil microbiota and to obtain the often scarce nutrients available, and many use secondary metabolites to facilitate this. We therefore (i) screened for antimicrobial properties of cold-environment Arctic and Antarctic soil fungi, and (ii) identified changes in the secreted secondary metabolite profiles of a subset of these strains in response to temperature variation. A total of 40 polar soil fungal strains from King George Island, maritime Antarctic and Hornsund, Svalbard, High Arctic, were obtained from the Malaysian National Antarctic Research Centre culture collections. The plug assay technique was used to screen for antimicrobial potential against Gram-positive and Gram-negative human pathogenic bacteria (Bacillus subtilis, B. cereus, Pseudomonas aeruginosa, Enterococcus faecalis and Escherichia coli). About 45% of the tested fungal strains showed antimicrobial activity against at least one tested microorganism. Three fungal isolates showed good bioactivity and were subjected to secondary metabolite profiling at different temperatures (4, 10, 15 and 28 °C). We observed a range of responses in fungal metabolite production when incubated at varying temperatures, confirming an influence of environmental conditions such as temperature on the production of secondary metabolites.

Comparison of expression of secondary metabolite biosynthesis cluster genes in Aspergillus flavus, A. parasiticus, and A. oryzae.

PubMed

Ehrlich, Kenneth C; Mack, Brian M

2014-06-23

Fifty six secondary metabolite biosynthesis gene clusters are predicted to be in the Aspergillus flavus genome. In spite of this, the biosyntheses of only seven metabolites, including the aflatoxins, kojic acid, cyclopiazonic acid and aflatrem, have been assigned to a particular gene cluster. We used RNA-seq to compare expression of secondary metabolite genes in gene clusters for the closely related fungi A. parasiticus, A. oryzae, and A. flavus S and L sclerotial morphotypes. The data help to refine the identification of probable functional gene clusters within these species. Our results suggest that A. flavus, a prevalent contaminant of maize, cottonseed, peanuts and tree nuts, is capable of producing metabolites which, besides aflatoxin, could be an underappreciated contributor to its toxicity.

Comparison of Expression of Secondary Metabolite Biosynthesis Cluster Genes in Aspergillus flavus, A. parasiticus, and A. oryzae

PubMed Central

Ehrlich, Kenneth C.; Mack, Brian M.

2014-01-01

Fifty six secondary metabolite biosynthesis gene clusters are predicted to be in the Aspergillus flavus genome. In spite of this, the biosyntheses of only seven metabolites, including the aflatoxins, kojic acid, cyclopiazonic acid and aflatrem, have been assigned to a particular gene cluster. We used RNA-seq to compare expression of secondary metabolite genes in gene clusters for the closely related fungi A. parasiticus, A. oryzae, and A. flavus S and L sclerotial morphotypes. The data help to refine the identification of probable functional gene clusters within these species. Our results suggest that A. flavus, a prevalent contaminant of maize, cottonseed, peanuts and tree nuts, is capable of producing metabolites which, besides aflatoxin, could be an underappreciated contributor to its toxicity. PMID:24960201

An IgaA/UmoB Family Protein from Serratia marcescens Regulates Motility, Capsular Polysaccharide Biosynthesis, and Secondary Metabolite Production.

PubMed

Stella, Nicholas A; Brothers, Kimberly M; Callaghan, Jake D; Passerini, Angelina M; Sigindere, Cihad; Hill, Preston J; Liu, Xinyu; Wozniak, Daniel J; Shanks, Robert M Q

2018-03-15

Secondary metabolites are an important source of pharmaceuticals and key modulators of microbe-microbe interactions. The bacterium Serratia marcescens is part of the Enterobacteriaceae family of eubacteria and produces a number of biologically active secondary metabolites. In this study, we screened for novel regulators of secondary metabolites synthesized by a clinical isolate of S. marcescens and found mutations in a gene for an uncharacterized UmoB/IgaA family member here named gumB Mutation of gumB conferred a severe loss of the secondary metabolites prodigiosin and serratamolide. The gumB mutation conferred pleiotropic phenotypes, including altered biofilm formation, highly increased capsular polysaccharide production, and loss of swimming and swarming motility. These phenotypes corresponded to transcriptional changes in fimA , wecA , and flhD Unlike other UmoB/IgaA family members, gumB was found to be not essential for growth in S. marcescens , yet igaA from Salmonella enterica , yrfF from Escherichia coli , and an uncharacterized predicted ortholog from Klebsiella pneumoniae complemented the gumB mutant secondary metabolite defects, suggesting highly conserved function. These data support the idea that UmoB/IgaA family proteins are functionally conserved and extend the known regulatory influence of UmoB/IgaA family proteins to the control of competition-associated secondary metabolites and biofilm formation. IMPORTANCE IgaA/UmoB family proteins are found in members of the Enterobacteriaceae family of bacteria, which are of environmental and public health importance. IgaA/UmoB family proteins are thought to be inner membrane proteins that report extracellular stresses to intracellular signaling pathways that respond to environmental challenge. This study introduces a new member of the IgaA/UmoB family and demonstrates a high degree of functional similarity between IgaA/UmoB family proteins. Moreover, this study extends the phenomena controlled by IgaA/UmoB family proteins to include the biosynthesis of antimicrobial secondary metabolites. Copyright © 2018 American Society for Microbiology.

A High-Resolution LC-MS-Based Secondary Metabolite Fingerprint Database of Marine Bacteria

PubMed Central

Lu, Liang; Wang, Jijie; Xu, Ying; Wang, Kailing; Hu, Yingwei; Tian, Renmao; Yang, Bo; Lai, Qiliang; Li, Yongxin; Zhang, Weipeng; Shao, Zongze; Lam, Henry; Qian, Pei-Yuan

2014-01-01

Marine bacteria are the most widely distributed organisms in the ocean environment and produce a wide variety of secondary metabolites. However, traditional screening for bioactive natural compounds is greatly hindered by the lack of a systematic way of cataloguing the chemical profiles of bacterial strains found in nature. Here we present a chemical fingerprint database of marine bacteria based on their secondary metabolite profiles, acquired by high-resolution LC-MS. Till now, 1,430 bacterial strains spanning 168 known species collected from different marine environments were cultured and profiled. Using this database, we demonstrated that secondary metabolite profile similarity is approximately, but not always, correlated with taxonomical similarity. We also validated the ability of this database to find species-specific metabolites, as well as to discover known bioactive compounds from previously unknown sources. An online interface to this database, as well as the accompanying software, is provided freely for the community to use. PMID:25298017

The Ecological Role of Volatile and Soluble Secondary Metabolites Produced by Soil Bacteria.

PubMed

Tyc, Olaf; Song, Chunxu; Dickschat, Jeroen S; Vos, Michiel; Garbeva, Paolina

2017-04-01

The rich diversity of secondary metabolites produced by soil bacteria has been appreciated for over a century, and advances in chemical analysis and genome sequencing continue to greatly advance our understanding of this biochemical complexity. However, we are just at the beginning of understanding the physicochemical properties of bacterial metabolites, the factors that govern their production and ecological roles. Interspecific interactions and competitor sensing are among the main biotic factors affecting the production of bacterial secondary metabolites. Many soil bacteria produce both volatile and soluble compounds. In contrast to soluble compounds, volatile organic compounds can diffuse easily through air- and gas-filled pores in the soil and likely play an important role in long-distance microbial interactions. In this review we provide an overview of the most important soluble and volatile classes of secondary metabolites produced by soil bacteria, their ecological roles, and their possible synergistic effects. Copyright © 2016 Elsevier Ltd. All rights reserved.

Isolation, structure elucidation and anticancer activity from Brevibacillus brevis EGS 9 that combats Multi Drug Resistant actinobacteria.

PubMed

Arumugam, T; Senthil Kumar, P; Hemavathy, R V; Swetha, V; Karishma Sri, R

2018-02-01

Actinobacteria is the most widely distributed organism in the mangrove environment and produce a large amount of secondary metabolites. A new environmental actinobacterial stain exhibited strong antimicrobial activity against vancomycin and methicillin resistant actinobacteria. The active producer strain was found to be as Brevibacillus brevis EGS9, which was confirmed by its morphological, biochemical characteristics and 16S rRNA gene sequencing. It was deposited in NCBI GeneBank database and received with an accession number of KX388147. Brevibacillus brevis EGS9 was cultivated by submerged fermentation to produce antimicrobial compounds. The anti-proliferative agent was extracted from Brevibacillus brevis EGS9 with ethyl acetate. The bioactive metabolites of mangrove actinobacteria was identified by Liquid chromatography with mass spectrometry analysis. The result of the present investigation revealed that actinobacteria isolated from mangroves are potent source of anticancer activity. The strain of Brevibacillus brevis EGS9 exhibited a potential in vitro anticancer activity. The present research concluded that the actinobacteria isolated from mangrove soil sediment are valuable in discovery of novel species. Copyright © 2017. Published by Elsevier Ltd.

Whole-plant C allocation priorities: do secondary metabolites and VOCs matter?

NASA Astrophysics Data System (ADS)

Hartmann, Henrik; Huang, Jianbei; Forkelova, Lenka; Behrendt, Thomas; Reichelt, Michael; Hammerbacher, Almuth

2017-04-01

Whole-plant carbon (C) allocation is a critical issue for understanding plant functioning and has been studied for many decades. Plants fix CO2 from the atmosphere and partition the resulting photosynthetic products (carbohydrates) among several functional pools including growth of structural and reproductive biomass, metabolic processes like respiration but also for the synthesis of secondary metabolites promoting defense and communication. Allocation to secondary metabolites is conceptually viewed as a trade-off between growth and defense. Plants either invest carbohydrates to produce biomass which may be lost - at least partially -to herbivory or they increase allocation to secondary metabolites to deter herbivores from consuming existing biomass. While conceptually intuitive, trade-off hypotheses all suffer from one important shortcoming: the whole-plant carbon balance, critical for determining trade-off relationships, is usually unknown. In the research group on Plant Allocation, we manipulate and measure the whole-plant carbon balance in different species and use tracers to investigate carbon fluxes through the plant and into functional allocation pools. Inducing carbon limitation by reducing atmospheric [CO2] allows us to infer allocation priorities. In this presentation I will show several examples of studies on whole-plant carbon allocation patterns in different plant species. These investigations include assessments of different functional pools like growth, storage, secondary metabolites and volatile emissions as well as the underlying phytohormonal patterns and show that allocation to secondary metabolites and volatiles has a high priority in the whole-plant carbon balance.

Allocation of secondary metabolites, photosynthetic capacity, and antioxidant activity of Kacip Fatimah (Labisia pumila Benth) in response to CO2 and light intensity.

PubMed

Ibrahim, Mohd Hafiz; Jaafar, Hawa Z E; Karimi, Ehsan; Ghasemzadeh, Ali

2014-01-01

A split plot 3 by 4 experiment was designed to investigate and distinguish the relationships among production of secondary metabolites, soluble sugar, phenylalanine ammonia lyase (PAL; EC 4.3.1.5) activity, leaf gas exchange, chlorophyll content, antioxidant activity (DPPH), and lipid peroxidation under three levels of CO2 (400, 800, and 1200 μ mol/mol) and four levels of light intensity (225, 500, 625, and 900 μ mol/m(2)/s) over 15 weeks in Labisia pumila. The production of plant secondary metabolites, sugar, chlorophyll content, antioxidant activity, and malondialdehyde content was influenced by the interactions between CO2 and irradiance. The highest accumulation of secondary metabolites, sugar, maliondialdehyde, and DPPH activity was observed under CO2 at 1200 μ mol/mol + light intensity at 225 μ mol/m(2)/s. Meanwhile, at 400 μ mol/mol CO2 + 900 μ mol/m(2)/s light intensity the production of chlorophyll and maliondialdehyde content was the highest. As CO2 levels increased from 400 to 1200 μ mol/mol the photosynthesis, stomatal conductance, f v /f m (maximum efficiency of photosystem II), and PAL activity were enhanced. The production of secondary metabolites displayed a significant negative relationship with maliondialdehyde indicating lowered oxidative stress under high CO2 and low irradiance improved the production of plant secondary metabolites that simultaneously enhanced the antioxidant activity (DPPH), thus improving the medicinal value of Labisia pumila under this condition.

Fruit wastes fermentation for phenolic antioxidants production and their application in manufacture of edible coatings and films.

PubMed

Martinez-Avila, G C G; Aguilera, A F; Saucedo, S; Rojas, R; Rodriguez, R; Aguilar, C N

2014-01-01

Agro-industrial by-products are important sources of potent bioactive phenolic compounds. These compounds are of extreme relevance for food and pharmacological industries due to their great variety of biological activities. Fermentation represents an environmentally clean technology for production and extraction of these bioactive compounds, providing high quality and high activity extracts, which can be incorporated in foods using coatings/films wax-based in order to avoid alterations in their quality. In this document is presented an overview about importance and benefits of solid-state fermentation, pointing out this bioprocess as an alternative technology for use agro-industrial by-products as substrates to produce valuable secondary metabolites and their applications as food quality conservatives.

Recombinant organisms for production of industrial products

PubMed Central

Adrio, Jose-Luis

2010-01-01

A revolution in industrial microbiology was sparked by the discoveries of ther double-stranded structure of DNA and the development of recombinant DNA technology. Traditional industrial microbiology was merged with molecular biology to yield improved recombinant processes for the industrial production of primary and secondary metabolites, protein biopharmaceuticals and industrial enzymes. Novel genetic techniques such as metabolic engineering, combinatorial biosynthesis and molecular breeding techniques and their modifications are contributing greatly to the development of improved industrial processes. In addition, functional genomics, proteomics and metabolomics are being exploited for the discovery of novel valuable small molecules for medicine as well as enzymes for catalysis. The sequencing of industrial microbal genomes is being carried out which bodes well for future process improvement and discovery of new industrial products. PMID:21326937

The development of microalgal biotechnology in the Czech Republic.

PubMed

Masojídek, Jiří; Prášil, Ondřej

2010-12-01

Microscopic algae and cyanobacteria are excellent sources of numerous compounds, from raw biomass rich in proteins, oils, and antioxidants to valuable secondary metabolites with potential medical use. In the former Czechoslovakia, microalgal biotechnology developed rapidly in the 1960s with the main aim of providing industrial, high-yield sources of algal biomass. Unique cultivation techniques that are still in use were successfully developed and tested. Gradually, the focus changed from bulk production to more sophisticated use of microalgae, including production of bioactive compounds. Along the way, better understanding of the physiology and cell biology of productive microalgal strains was achieved. Currently, microalgae are in the focus again, mostly as possible sources of bioactive compounds and next-generation biofuels for the 21st century.

Spatial regulation of a common precursor from two distinct genes generates metabolite diversity

DOE PAGES

Guo, Chun -Jun; Sun, Wei -Wen; Bruno, Kenneth S.; ...

2015-07-13

In secondary metabolite biosynthesis, core synthetic genes such as polyketide synthase genes usually encode proteins that generate various backbone precursors. These precursors are modified by other tailoring enzymes to yield a large variety of different secondary metabolites. The number of core synthesis genes in a given species correlates, therefore, with the number of types of secondary metabolites the organism can produce. In our study, heterologous expression of all the A. terreus NRPSlike genes showed that two NRPS-like proteins, encoded by atmelA and apvA, release the same natural product, aspulvinone E. In hyphae this compound is converted to aspulvinones whereas inmore » conidia it is converted to melanin. The genes are expressed in different tissues and this spatial control is probably regulated by their own specific promoters. Comparative genomics indicates that atmelA and apvA might share a same ancestral gene and the gene apvA is located in a highly conserved region in Aspergillus species that contains genes coding for life-essential proteins. Our data reveal the first case in secondary metabolite biosynthesis in which the tissue specific production of a single compound directs it into two separate pathways, producing distinct compounds with different functions. Our data also reveal that a single trans-prenyltransferase, AbpB, prenylates two substrates, aspulvinones and butyrolactones, revealing that genes outside of contiguous secondary metabolism gene clusters can modify more than one compound thereby expanding metabolite diversity. Our study raises the possibility of incorporation of spatial, cell-type specificity in expression of secondary metabolites of biological interest and provides new insight into designing and reconstituting their biosynthetic pathways.« less

[The biosynthesis of low-molecular-weight nitrogen-containing secondary metabolite-alkaloids by the resident strains of Penicillium chrysogenum and Penicillium expansum isolated on the board of the Mir space station ].

PubMed

Kozlovskiĭ, A G; Zhelifonova, V P; Adanin, V M; Antipova, T V; Shnyreva, A V; Viktorov, A N

2002-01-01

The analysis of the absorption spectra of the low-molecular-weight nitrogen-containing secondary metabolites--alkaloids--of 4 Penicillium chrysogenum strains and 6 Penicillium expansum strains isolated on board the Mir space station showed that all these strains synthesize metabolites of alkaloid origin (roquefortine, 3,12-dihydroroquefortine, meleagrin, viridicatin, viridicatol, isorugulosuvin, rugulosuvin B, N-acetyl-tryptamine, and a "yellow metabolite" containing the benzoquinone chromophore).

Secondary metabolites in plant innate immunity: conserved function of divergent chemicals.

PubMed

Piasecka, Anna; Jedrzejczak-Rey, Nicolas; Bednarek, Paweł

2015-05-01

Plant secondary metabolites carry out numerous functions in interactions between plants and a broad range of other organisms. Experimental evidence strongly supports the indispensable contribution of many constitutive and pathogen-inducible phytochemicals to plant innate immunity. Extensive studies on model plant species, particularly Arabidopsis thaliana, have brought significant advances in our understanding of the molecular mechanisms underpinning pathogen-triggered biosynthesis and activation of defensive secondary metabolites. However, despite the proven significance of secondary metabolites in plant response to pathogenic microorganisms, little is known about the precise mechanisms underlying their contribution to plant immunity. This insufficiency concerns information on the dynamics of cellular and subcellular localization of defensive phytochemicals during the encounters with microbial pathogens and precise knowledge on their mode of action. As many secondary metabolites are characterized by their in vitro antimicrobial activity, these compounds were commonly considered to function in plant defense as in planta antibiotics. Strikingly, recent experimental evidence suggests that at least some of these compounds alternatively may be involved in controlling several immune responses that are evolutionarily conserved in the plant kingdom, including callose deposition and programmed cell death. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

[Effects of environmental stress on secondary metabolites of Aspergillus ochraceus LCJ11-102 associated with the coral Dichotella gemmacea].

PubMed

Zhou, Yalin; Wang, Yi; Liu, Peipei; Wang, Zhiying; Zhu, Weiming

2010-08-01

To explore the secondary metabolites of fungus Aspergillus ochraceus LCJ11-102 associated with the coral Dichotella gemmacea under environmental stress and to obtain characteristic compounds with biological activities. A nutrient-deprived culture medium (biomimetic culture) and a high salt culture medium were used for fermentation. Fingerprints of HPLC of the fermentation broth were used to investigate the diversity of secondary metabolites. Compounds were isolated by column chromatography on silica gel, Sephadex LH-20, and preparative HPLC. Their structures were identified by spectroscopic analyses and the modified Mosher's method. Different secondary metabolites were produced by A. ochraceus LCJ11-102 under two different culture conditions. (R)-mellein (1), (5,6-trans, 8,9-threo-) -9-chloro-8-hydroxy-8, 9-deoxyaspyrone (2), (5,6-erythro-, 8,9-threo-) -9-chloro-8-hydroxy-8, 9-deoxyasperlactone (3), and (5S, 6R, 9S)-dihydroaspyrone (4) were identified from the biomimetic cultures, and R (+) -semi-vioxanthin (5) was identified from the high salt cultures, respectively. Environmental stress obviously induces microbes to produce different secondary metabolites. And biomimetic culture is an effective approach to obtain active chloro compounds from marine microorganisms.

Secondary Metabolites from Marine Microorganisms. II. Marine Fungi and Their Habitats.

PubMed

Orlova, T I; Bulgakova, V G; Polin, A N

Marine-derived fungi are of great interest as a new promising source of biologically active products such as anticancer compounds, antibiotics, inhibitors of biochemical processes. Since marine organisms inhabit biologically competitive environment with unique conditions, the chemical diversity of the secondary metabolites from marine fungi is considerably high. Recent genomic studies demonstrated that fungi can carry gene clasters encoding production of previously unknown secondary metabolites. Activation of the attenuated or silent genes would be useful either for improving activities of the known compounds or for discovery of new products.

Chemical ecology of insect-plant interactions: ecological significance of plant secondary metabolites.

PubMed

Nishida, Ritsuo

2014-01-01

Plants produce a diverse array of secondary metabolites as chemical barriers against herbivores. Many phytophagous insects are highly adapted to these allelochemicals and use such unique substances as the specific host-finding cues, defensive substances of their own, and even as sex pheromones or their precursors by selectively sensing, incorporating, and/or processing these phytochemicals. Insects also serve as pollinators often effectively guided by specific floral fragrances. This review demonstrates the ecological significance of such plant secondary metabolites in the highly diverse interactions between insects and plants.

Effects of Secondary Metabolites of Permafrost Bacillus sp. on Cytokine Synthesis by Human Peripheral Blood Mononuclear Cells.

PubMed

Kalenova, L F; Kolyvanova, S S; Bazhin, A S; Besedin, I M; Mel'nikov, V P

2017-06-01

We studied the effects of secondary metabolites of Bacillus sp. isolated from late Neogene permafrost on secretion of proinflammatory (TNF-α, IL-1β, IL-8, IL-2, and IFNγ) and antiinflammatory (IL-4 and IL-10) cytokines by human peripheral blood mononuclear cells. It was found that metabolites of Bacillus sp. produced more potent effect on cytokine secretion than mitogen phytohemagglutinin and metabolites of Bacillus cereus, medicinal strain IP5832. Activity of metabolites depended on the temperature of bacteria incubation. "Cold" metabolites of Bacillus sp. (isolated at -5°C) primarily induced Th1-mediated secretion of IFNγ, while "warm" metabolites (obtained at 37°C) induced Th2-mediated secretion of IL-4. The results suggest that Bacillus sp. metabolites are promising material for the development of immunomodulating drugs.

[Influence of incubation time on metabolites in mycelia of Paecilomyces militaris].

PubMed

Zhang, Delong; Li, Shulin; Lu, Ruili; Li, Kangle; Luo, Feifei; Peng, Fan; Hu, Fenglin

2012-12-04

To determine the secondary metabolites production in mycelia of Paecilomyces militaris. Mycelia were cultured in plates with sabouraud dextrose agar yeast medium at 25 degrees C for 9 days. Sampling was done every day from the second to the ninth day. The secondary metabolites in the mycelia of Paecilomyces militaris were extracted with either methanol or ethyl acetate. The extracts were blended and analyzed by liquid chromatography-mass spectrometry (LC-MS). LC-MS data were collected and analyzed by MetaboAnalyst software. Principal component analysis indicates different secondary metabolites accumulation with incubation times. Hierarchical clustering analysis shows that the metabolic process of cationic compounds such as alkaloids, peptides and nucleosides can be divided into three stages, and that the metabolic process of anionic compounds such as organic acids and saccharides can be divided into two stages. Metabolites difference and heat map analysis show that: (1) The number of metabolites with significant increased contents was raised significantly in mycelia of Paecilomyces militaris on the second and third incubation days. The main species with increased contents were esters and their hydrolized products, destruxin B, variotin and some unidentified nitrogin contained compounds. (2) The number of metabolites with significant raised contents was decreased significantly on the fourth and fifth incubation days. The main species with increased contents were ophiocordin and destruxin A. (3) Apart from peptide antibiotics such as several beauverolides, the content increased metabolites included also several organic acids, amino acids, rhamnose, trehalose, cerebroside and riboflavine during the sixth to ninth incubation days. The secondary metabolites in mycelia of Paecilomyces militaris were related significantly to the incubation time.

Secondary metabolites of cyanobacteria Nostoc sp.

NASA Astrophysics Data System (ADS)

Kobayashi, Akio; Kajiyama, Shin-Ichiro

1998-03-01

Cyanobacteria attracted much attention recently because of their secondary metabolites with potent biological activities and unusual structures. This paper reviews some recent studies on the isolation, structural, elucidation and biological activities of the bioactive compounds from cyanobacteria Nostoc species.

Bioactive secondary metabolites from marine microbes for drug discovery.

PubMed

Nikapitiya, Chamilani

2012-01-01

The isolation and extraction of novel bioactive secondary metabolites from marine microorganisms have a biomedical potential for future drug discovery as the oceans cover 70% of the planet's surface and life on earth originates from sea. Wide range of novel bioactive secondary metabolites exhibiting pharmacodynamic properties has been isolated from marine microorganisms and many to be discovered. The compounds isolated from marine organisms (macro and micro) are important in their natural form and also as templates for synthetic modifications for the treatments for variety of deadly to minor diseases. Many technical issues are yet to overcome before wide-scale bioprospecting of marine microorganisms becomes a reality. This chapter focuses on some novel secondary metabolites having antitumor, antivirus, enzyme inhibitor, and other bioactive properties identified and isolated from marine microorganisms including bacteria, actinomycetes, fungi, and cyanobacteria, which could serve as potentials for drug discovery after their clinical trials. Copyright © 2012 Elsevier Inc. All rights reserved.

Chemosensation of Bacterial Secondary Metabolites Modulates Neuroendocrine Signaling and Behavior of C. elegans

PubMed Central

Meisel, Joshua D.; Panda, Oishika; Mahanti, Parag; Schroeder, Frank C.; Kim, Dennis H.

2014-01-01

Summary Discrimination among pathogenic and beneficial microbes is essential for host organism immunity and homeostasis. Here, we show that chemosensory detection of two secondary metabolites produced by Pseudomonas aeruginosa modulates a neuroendocrine signaling pathway that promotes avoidance behavior in the simple animal host Caenorhabditis elegans. Secondary metabolites phenazine-1-carboxamide and pyochelin activate a G protein-signaling pathway in the ASJ chemosensory neuron pair that induces expression of the neuromodulator DAF-7/TGF-β. DAF-7, in turn, activates a canonical TGF-β signaling pathway in adjacent interneurons to modulate aerotaxis behavior and promote avoidance of pathogenic P. aeruginosa. Our data provide a chemical, genetic, and neuronal basis for how the behavior and physiology of a simple animal host can be modified by the microbial environment, and suggest that secondary metabolites produced by microbes may provide environmental cues that contribute to pathogen recognition and host survival. PMID:25303524

Dynamic changes in plant secondary metabolites during UV acclimation in Arabidopsis thaliana.

PubMed

Hectors, Kathleen; Van Oevelen, Sandra; Geuns, Jan; Guisez, Yves; Jansen, Marcel A K; Prinsen, Els

2014-10-01

Plants respond to environmental stress by synthesizing a range of secondary metabolites for defense purposes. Here we report on the effect of chronic ultraviolet (UV) radiation on the accumulation of plant secondary metabolites in Arabidopsis thaliana leaves. In the natural environment, UV is a highly dynamic environmental parameter and therefore we hypothesized that plants are continuously readjusting levels of secondary metabolites. Our data show distinct kinetic profiles for accumulation of tocopherols, polyamines and flavonoids upon UV acclimation. The lipid-soluble antioxidant α-tocopherol accumulated fast and remained elevated. Polyamines accumulated fast and transiently. This fast response implies a role for α-tocopherol and polyamines in short-term UV response. In contrast, an additional sustained accumulation of flavonols took place. The distinct accumulation patterns of these secondary metabolites confirm that the UV acclimation process is a dynamic process, and indicates that commonly used single time-point analyses do not reveal the full extent of UV acclimation. We demonstrate that UV stimulates the accumulation of specific flavonol glycosides, i.e. kaempferol and (to a lesser extent) quercetin di- and triglycosides, all specifically rhamnosylated at position seven. All metabolites were identified by Ultra Performance Liquid Chromatography (UPLC)-coupled tandem mass spectrometry. Some of these flavonol glycosides reached steady-state levels in 3-4 days, while concentrations of others are still increasing after 12  days of UV exposure. A biochemical pathway for these glycosides is postulated involving 7-O-rhamnosylation for the synthesis of all eight metabolites identified. We postulate that this 7-O-rhamnosylation has an important function in UV acclimation. © 2014 Scandinavian Plant Physiology Society.

Analysis of uncultured extremophilic snow algae by non-invasive single cell Raman spectroscopy

NASA Astrophysics Data System (ADS)

Beer, Thomas; Tanaka, Zuki; Netzter, Nathan; Rothschild, Lynn J.; Chen, Bin

2011-10-01

The study of life in extreme environments is a critical component of Astrobiology. But many of the so-called "extremophiles" are not readily cultivatable and therefore difficult to study under laboratory conditions. An example of such an extremophile is the snow alga Chlamydomonas cd. nivalis which expresses still unstudied secondary metabolites within its life cycle. In this paper, we present the first time the non-invasive single cell Raman spectroscopy of the life cycle dependent metabolite composition of C. nivalis. These secondary metabolites are likely related to the adaptation of C. nivalis to various stress factors. Normalized carotenoid Raman spectra intensities reveal characteristic ratio differences that allow identification of life cycle stages and putative secondary metabolites.

Strategies to enhance biologically active-secondary metabolites in cell cultures of Artemisia - current trends.

PubMed

Ali, Mohammad; Abbasi, Bilal Haider; Ahmad, Nisar; Khan, Haji; Ali, Gul Shad

2017-11-01

The genus Artemisia has been utilized worldwide due to its immense potential for protection against various diseases, especially malaria. Artemisia absinthium, previously renowned for its utilization in the popular beverage absinthe, is gaining resurgence due to its extensive pharmacological activities. Like A. annua, this species exhibits strong biological activities like antimalarial, anticancer and antioxidant. Although artemisinin was found to be the major metabolite for its antimalarial effects, several flavonoids and terpenoids are considered to possess biological activities when used alone and also to synergistically boost the bioavailability of artemisinin. However, due to the limited quantities of these metabolites in wild plants, in vitro cultures were established and strategies have been adopted to enhance medicinally important secondary metabolites in these cultures. This review elaborates on the traditional medicinal uses of Artemisia species and explains current trends to establish cell cultures of A. annua and A. absinthium for enhanced production of medicinally important secondary metabolites.

Chemical perturbation of secondary metabolism demonstrates important links to primary metabolism.

PubMed

Craney, Arryn; Ozimok, Cory; Pimentel-Elardo, Sheila Marie; Capretta, Alfredo; Nodwell, Justin R

2012-08-24

Bacterially produced secondary metabolites are used as antibiotics, anticancer drugs, and for many other medicinal applications. The mechanisms that limit the production of these molecules in the laboratory are not well understood, and this has impeded the discovery of many important compounds. We have identified small molecules that remodel the yields of secondary metabolites in many actinomycetes and show that one set of these molecules does so by inhibiting fatty acid biosynthesis. This demonstrates a particularly intimate relationship between this primary metabolic pathway and secondary metabolism and suggests an approach to enhance the yields of metabolites for discovery and biochemical characterization. Copyright © 2012 Elsevier Ltd. All rights reserved.

Allocation of Secondary Metabolites, Photosynthetic Capacity, and Antioxidant Activity of Kacip Fatimah (Labisia pumila Benth) in Response to CO2 and Light Intensity

PubMed Central

Jaafar, Hawa Z. E.; Karimi, Ehsan; Ghasemzadeh, Ali

2014-01-01

A split plot 3 by 4 experiment was designed to investigate and distinguish the relationships among production of secondary metabolites, soluble sugar, phenylalanine ammonia lyase (PAL; EC 4.3.1.5) activity, leaf gas exchange, chlorophyll content, antioxidant activity (DPPH), and lipid peroxidation under three levels of CO2 (400, 800, and 1200 μmol/mol) and four levels of light intensity (225, 500, 625, and 900 μmol/m2/s) over 15 weeks in Labisia pumila. The production of plant secondary metabolites, sugar, chlorophyll content, antioxidant activity, and malondialdehyde content was influenced by the interactions between CO2 and irradiance. The highest accumulation of secondary metabolites, sugar, maliondialdehyde, and DPPH activity was observed under CO2 at 1200 μmol/mol + light intensity at 225 μmol/m2/s. Meanwhile, at 400 μmol/mol CO2 + 900 μmol/m2/s light intensity the production of chlorophyll and maliondialdehyde content was the highest. As CO2 levels increased from 400 to 1200 μmol/mol the photosynthesis, stomatal conductance, f v/f m (maximum efficiency of photosystem II), and PAL activity were enhanced. The production of secondary metabolites displayed a significant negative relationship with maliondialdehyde indicating lowered oxidative stress under high CO2 and low irradiance improved the production of plant secondary metabolites that simultaneously enhanced the antioxidant activity (DPPH), thus improving the medicinal value of Labisia pumila under this condition. PMID:24683336

Crop-ecology and nutritional variability influence growth and secondary metabolites of Stevia rebaudiana Bertoni.

PubMed

Pal, Probir Kumar; Kumar, Rajender; Guleria, Vipan; Mahajan, Mitali; Prasad, Ramdeen; Pathania, Vijaylata; Gill, Baljinder Singh; Singh, Devinder; Chand, Gopi; Singh, Bikram; Singh, Rakesh Deosharan; Ahuja, Paramvir Singh

2015-02-27

Plant nutrition and climatic conditions play important roles on the growth and secondary metabolites of stevia (Stevia rebaudiana Bertoni); however, the nutritional dose is strongly governed by the soil properties and climatic conditions of the growing region. In northern India, the interactive effects of crop ecology and plant nutrition on yield and secondary metabolites of stevia are not yet properly understood. Thus, a field experiment comprising three levels of nitrogen, two levels of phosphorus and three levels of potassium was conducted at three locations to ascertain whether the spatial and nutritional variability would dominate the leaf yield and secondary metabolites profile of stevia. Principal component analysis (PCA) indicates that the applications of 90 kg N, 40 kg P2O5 and 40 kg K2O ha-1 are the best nutritional conditions in terms of dry leaf yield for CSIR-IHBT (Council of Scientific and Industrial Research- Institute Himalayan Bioresource Technology) and RHRS (Regional Horticultural Research Station) conditions. The spatial variability also exerted considerable effect on the leaf yield and stevioside content in leaves. Among the three locations, CSIR-IHBT was found most suitable in case of dry leaf yield and secondary metabolites accumulation in leaves. The results suggest that dry leaf yield and accumulation of stevioside are controlled by the environmental factors and agronomic management; however, the accumulation of rebaudioside-A (Reb-A) is not much influenced by these two factors. Thus, leaf yield and secondary metabolite profiles of stevia can be improved through the selection of appropriate growing locations and proper nutrient management.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guo, Chun -Jun; Sun, Wei -Wen; Bruno, Kenneth S.

In secondary metabolite biosynthesis, core synthetic genes such as polyketide synthase genes usually encode proteins that generate various backbone precursors. These precursors are modified by other tailoring enzymes to yield a large variety of different secondary metabolites. The number of core synthesis genes in a given species correlates, therefore, with the number of types of secondary metabolites the organism can produce. In our study, heterologous expression of all the A. terreus NRPSlike genes showed that two NRPS-like proteins, encoded by atmelA and apvA, release the same natural product, aspulvinone E. In hyphae this compound is converted to aspulvinones whereas inmore » conidia it is converted to melanin. The genes are expressed in different tissues and this spatial control is probably regulated by their own specific promoters. Comparative genomics indicates that atmelA and apvA might share a same ancestral gene and the gene apvA is located in a highly conserved region in Aspergillus species that contains genes coding for life-essential proteins. Our data reveal the first case in secondary metabolite biosynthesis in which the tissue specific production of a single compound directs it into two separate pathways, producing distinct compounds with different functions. Our data also reveal that a single trans-prenyltransferase, AbpB, prenylates two substrates, aspulvinones and butyrolactones, revealing that genes outside of contiguous secondary metabolism gene clusters can modify more than one compound thereby expanding metabolite diversity. Our study raises the possibility of incorporation of spatial, cell-type specificity in expression of secondary metabolites of biological interest and provides new insight into designing and reconstituting their biosynthetic pathways.« less

Applications of flow cytometry to toxicological mycotoxin effects in cultured mammalian cells: a review.

PubMed

Juan-García, Ana; Manyes, Lara; Ruiz, María-José; Font, Guillermina

2013-06-01

This review gives an overview of flow cytometry applications to toxicological studies of several physiological target sites of mycotoxins on different mammalian cell lines. Mycotoxins are secondary metabolites of fungi that may be present in food, feed, air and water. The increasing presence of mycotoxins in crops, their wide distribution in the food chain, and their potential for toxicity demonstrate the need for further knowledge. Flow cytometry has become a valuable tool in mycotoxin studies in recent years for the rapid analysis of single cells in a mixture. In toxicology, the power of these methods lies in the possibility of determining a wide range of cell parameters, providing valuable information to elucidate cell growth and viability, metabolic activity, mitochondrial membrane potential and membrane integrity mechanisms. There are studies using flow cytometry technique on Alternaria, Aspergillus, Fusarium and Penicillium mycotoxins including information about cell type, assay conditions and functional parameters. Most of the studies collected in the literature are on deoxynivalenol and zearalenone mycotoxins. Cell cycle analysis and apoptosis are the processes more widely investigated. Copyright © 2013 Elsevier Ltd. All rights reserved.

Strain-Level Diversity of Secondary Metabolism in Streptomyces albus

PubMed Central

Seipke, Ryan F.

2015-01-01

Streptomyces spp. are robust producers of medicinally-, industrially- and agriculturally-important small molecules. Increased resistance to antibacterial agents and the lack of new antibiotics in the pipeline have led to a renaissance in natural product discovery. This endeavor has benefited from inexpensive high quality DNA sequencing technology, which has generated more than 140 genome sequences for taxonomic type strains and environmental Streptomyces spp. isolates. Many of the sequenced streptomycetes belong to the same species. For instance, Streptomyces albus has been isolated from diverse environmental niches and seven strains have been sequenced, consequently this species has been sequenced more than any other streptomycete, allowing valuable analyses of strain-level diversity in secondary metabolism. Bioinformatics analyses identified a total of 48 unique biosynthetic gene clusters harboured by Streptomyces albus strains. Eighteen of these gene clusters specify the core secondary metabolome of the species. Fourteen of the gene clusters are contained by one or more strain and are considered auxiliary, while 16 of the gene clusters encode the production of putative strain-specific secondary metabolites. Analysis of Streptomyces albus strains suggests that each strain of a Streptomyces species likely harbours at least one strain-specific biosynthetic gene cluster. Importantly, this implies that deep sequencing of a species will not exhaust gene cluster diversity and will continue to yield novelty. PMID:25635820

Primary expectations of secondary metabolites

USDA-ARS?s Scientific Manuscript database

Plant secondary metabolites (e.g., phenolics) are important for human health, in addition to the organoleptic properties they impart to fresh and processed foods. Consumer expectations such as appearance, taste, or texture influence their purchasing decisions. Thorough identification of phenolic com...

Primary expectations of secondary metabolites

USDA-ARS?s Scientific Manuscript database

My program examines the plant secondary metabolites (i.e. phenolics) important for human health, and which impart the organoleptic properties that are quality indicators for fresh and processed foods. Consumer expectations such as appearance, taste, or texture influence their purchasing decisions; a...

Association of fungal secondary metabolism and sclerotial biology

PubMed Central

Calvo, Ana M.; Cary, Jeffrey W.

2015-01-01

Fungal secondary metabolism and morphological development have been shown to be intimately associated at the genetic level. Much of the literature has focused on the co-regulation of secondary metabolite production (e.g., sterigmatocystin and aflatoxin in Aspergillus nidulans and Aspergillus flavus, respectively) with conidiation or formation of sexual fruiting bodies. However, many of these genetic links also control sclerotial production. Sclerotia are resistant structures produced by a number of fungal genera. They also represent the principal source of primary inoculum for some phytopathogenic fungi. In nature, higher plants often concentrate secondary metabolites in reproductive structures as a means of defense against herbivores and insects. By analogy, fungi also sequester a number of secondary metabolites in sclerotia that act as a chemical defense system against fungivorous predators. These include antiinsectant compounds such as tetramic acids, indole diterpenoids, pyridones, and diketopiperazines. This chapter will focus on the molecular mechanisms governing production of secondary metabolites and the role they play in sclerotial development and fungal ecology, with particular emphasis on Aspergillus species. The global regulatory proteins VeA and LaeA, components of the velvet nuclear protein complex, serve as virulence factors and control both development and secondary metabolite production in many Aspergillus species. We will discuss a number of VeA- and LaeA-regulated secondary metabolic gene clusters in A. flavus that are postulated to be involved in sclerotial morphogenesis and chemical defense. The presence of multiple regulatory factors that control secondary metabolism and sclerotial formation suggests that fungi have evolved these complex regulatory mechanisms as a means to rapidly adapt chemical responses to protect sclerotia from predators, competitors and other environmental stressors. PMID:25762985

Genetic and metabolite diversity of Sardinian populations of Helichrysum italicum.

PubMed

Melito, Sara; Sias, Angela; Petretto, Giacomo L; Chessa, Mario; Pintore, Giorgio; Porceddu, Andrea

2013-01-01

Helichrysum italicum (Asteraceae) is a small shrub endemic to the Mediterranean Basin, growing in fragmented and diverse habitats. The species has attracted attention due to its secondary metabolite content, but little effort has as yet been dedicated to assessing the genetic and metabolite diversity present in these populations. Here, we describe the diversity of 50 H. italicum populations collected from a range of habitats in Sardinia. H. italicum plants were AFLP fingerprinted and the composition of their leaf essential oil characterized by GC-MS. The relationships between the genetic structure of the populations, soil, habitat and climatic variables and the essential oil chemotypes present were evaluated using Bayesian clustering, contingency analyses and AMOVA. The Sardinian germplasm could be partitioned into two AFLP-based clades. Populations collected from the southwestern region constituted a homogeneous group which remained virtually intact even at high levels of K. The second, much larger clade was more diverse. A positive correlation between genetic diversity and elevation suggested the action of natural purifying selection. Four main classes of compounds were identified among the essential oils, namely monoterpenes, oxygenated monoterpenes, sesquiterpenes and oxygenated sesquiterpenes. Oxygenated monoterpene levels were significantly correlated with the AFLP-based clade structure, suggesting a correspondence between gene pool and chemical diversity. The results suggest an association between chemotype, genetic diversity and collection location which is relevant for the planning of future collections aimed at identifying valuable sources of essential oil.

[Application and prospect of fungi elicitors in fermentation industry].

PubMed

Gu, Shaobin; Gong, Hui; Yang, Bin; Bu, Meiling

2013-11-01

Fungal elicitors are a group of chemicals that can stimulate the secondary metabolite production in plants and microbial cells. After being recognized, it could enhance the expression of related genes through the signal-transduction pathway; regulate the activity of the enzyme involved in the biosynthesis of secondary metabolites. In recent years, the inducible mechanism of fungal elicitors has been studied deeply worldwide. Meanwhile, it has acquired wide concern in the area of biological industry, especially in the fermentation industry. This paper addresses the application and prospect of fungal elicitors in the secondary metabolites of plant and microbial cells.

Increasing carbon availability stimulates growth and secondary metabolites via modulation of phytohormones in winter wheat

PubMed Central

Reichelt, Michael; Chowdhury, Somak; Hammerbacher, Almuth; Hartmann, Henrik

2017-01-01

Abstract Phytohormones play important roles in plant acclimation to changes in environmental conditions. However, their role in whole-plant regulation of growth and secondary metabolite production under increasing atmospheric CO2 concentrations ([CO2]) is uncertain but crucially important for understanding plant responses to abiotic stresses. We grew winter wheat (Triticum aestivum) under three [CO2] (170, 390, and 680 ppm) over 10 weeks, and measured gas exchange, relative growth rate (RGR), soluble sugars, secondary metabolites, and phytohormones including abscisic acid (ABA), auxin (IAA), jasmonic acid (JA), and salicylic acid (SA) at the whole-plant level. Our results show that, at the whole-plant level, RGR positively correlated with IAA but not ABA, and secondary metabolites positively correlated with JA and JA-Ile but not SA. Moreover, soluble sugars positively correlated with IAA and JA but not ABA and SA. We conclude that increasing carbon availability stimulates growth and production of secondary metabolites via up-regulation of auxin and jasmonate levels, probably in response to sugar-mediated signalling. Future low [CO2] studies should address the role of reactive oxygen species (ROS) in leaf ABA and SA biosynthesis, and at the transcriptional level should focus on biosynthetic and, in particular, on responsive genes involved in [CO2]-induced hormonal signalling pathways. PMID:28159987

Antifeedant Activity of Ginkgo biloba Secondary Metabolites against Hyphantria cunea Larvae: Mechanisms and Applications

PubMed Central

Ren, Lili; Chen, Fang; Feng, Yuqian

2016-01-01

Ginkgo biloba is a typical relic plant that rarely suffers from pest hazards. This study analyzed the pattern of G. biloba pest hazards in Beijing; tested the antifeedant activity of G. biloba extracts, including ginkgo flavonoids, ginkgolide, and bilobalide, against Hyphantria cunea larvae; determined the activities of glutathione transferase (GSTs), acetylcholinesterase (AChE), carboxylesterase (CarE) and mixed-functional oxidase (MFO), in larvae after feeding on these G. biloba secondary metabolites; and screened for effective botanical antifeedants in the field. In this study, no indicators of insect infestation were found for any of the examined leaves of G. biloba; all tested secondary metabolites showed significant antifeedant activity and affected the activity of the four larval detoxifying enzymes. Ginkgolide had the highest antifeedant activity and the most significant effect on the detoxifying enzymes (P<0.05). Spraying leaves with G. biloba extracts or ginkgolide both significantly repelled H. cunea larvae in the field (P<0.05), although the former is more economical and practical. This study investigated the antifeedant activity of G. biloba secondary metabolites against H. cunea larvae, and the results provide new insights into the mechanism of G. biloba pest resistance. This study also developed new applications of G. biloba secondary metabolites for effective pest control. PMID:27214257

Antifeedant Activity of Ginkgo biloba Secondary Metabolites against Hyphantria cunea Larvae: Mechanisms and Applications.

PubMed

Pan, Long; Ren, Lili; Chen, Fang; Feng, Yuqian; Luo, Youqing

2016-01-01

Ginkgo biloba is a typical relic plant that rarely suffers from pest hazards. This study analyzed the pattern of G. biloba pest hazards in Beijing; tested the antifeedant activity of G. biloba extracts, including ginkgo flavonoids, ginkgolide, and bilobalide, against Hyphantria cunea larvae; determined the activities of glutathione transferase (GSTs), acetylcholinesterase (AChE), carboxylesterase (CarE) and mixed-functional oxidase (MFO), in larvae after feeding on these G. biloba secondary metabolites; and screened for effective botanical antifeedants in the field. In this study, no indicators of insect infestation were found for any of the examined leaves of G. biloba; all tested secondary metabolites showed significant antifeedant activity and affected the activity of the four larval detoxifying enzymes. Ginkgolide had the highest antifeedant activity and the most significant effect on the detoxifying enzymes (P<0.05). Spraying leaves with G. biloba extracts or ginkgolide both significantly repelled H. cunea larvae in the field (P<0.05), although the former is more economical and practical. This study investigated the antifeedant activity of G. biloba secondary metabolites against H. cunea larvae, and the results provide new insights into the mechanism of G. biloba pest resistance. This study also developed new applications of G. biloba secondary metabolites for effective pest control.

The diversity of anti-microbial secondary metabolites produced by fungal endophytes: an interdisciplinary perspective.

PubMed

Mousa, Walaa Kamel; Raizada, Manish N

2013-01-01

Endophytes are microbes that inhabit host plants without causing disease and are reported to be reservoirs of metabolites that combat microbes and other pathogens. Here we review diverse classes of secondary metabolites, focusing on anti-microbial compounds, synthesized by fungal endophytes including terpenoids, alkaloids, phenylpropanoids, aliphatic compounds, polyketides, and peptides from the interdisciplinary perspectives of biochemistry, genetics, fungal biology, host plant biology, human and plant pathology. Several trends were apparent. First, host plants are often investigated for endophytes when there is prior indigenous knowledge concerning human medicinal uses (e.g., Chinese herbs). However, within their native ecosystems, and where investigated, endophytes were shown to produce compounds that target pathogens of the host plant. In a few examples, both fungal endophytes and their hosts were reported to produce the same compounds. Terpenoids and polyketides are the most purified anti-microbial secondary metabolites from endophytes, while flavonoids and lignans are rare. Examples are provided where fungal genes encoding anti-microbial compounds are clustered on chromosomes. As different genera of fungi can produce the same metabolite, genetic clustering may facilitate sharing of anti-microbial secondary metabolites between fungi. We discuss gaps in the literature and how more interdisciplinary research may lead to new opportunities to develop bio-based commercial products to combat global crop and human pathogens.

The Diversity of Anti-Microbial Secondary Metabolites Produced by Fungal Endophytes: An Interdisciplinary Perspective

PubMed Central

Mousa, Walaa Kamel; Raizada, Manish N.

2013-01-01

Endophytes are microbes that inhabit host plants without causing disease and are reported to be reservoirs of metabolites that combat microbes and other pathogens. Here we review diverse classes of secondary metabolites, focusing on anti-microbial compounds, synthesized by fungal endophytes including terpenoids, alkaloids, phenylpropanoids, aliphatic compounds, polyketides, and peptides from the interdisciplinary perspectives of biochemistry, genetics, fungal biology, host plant biology, human and plant pathology. Several trends were apparent. First, host plants are often investigated for endophytes when there is prior indigenous knowledge concerning human medicinal uses (e.g., Chinese herbs). However, within their native ecosystems, and where investigated, endophytes were shown to produce compounds that target pathogens of the host plant. In a few examples, both fungal endophytes and their hosts were reported to produce the same compounds. Terpenoids and polyketides are the most purified anti-microbial secondary metabolites from endophytes, while flavonoids and lignans are rare. Examples are provided where fungal genes encoding anti-microbial compounds are clustered on chromosomes. As different genera of fungi can produce the same metabolite, genetic clustering may facilitate sharing of anti-microbial secondary metabolites between fungi. We discuss gaps in the literature and how more interdisciplinary research may lead to new opportunities to develop bio-based commercial products to combat global crop and human pathogens. PMID:23543048

Tiny Microbes with a Big Impact: The Role of Cyanobacteria and Their Metabolites in Shaping Our Future

PubMed Central

Mazard, Sophie; Penesyan, Anahit; Ostrowski, Martin; Paulsen, Ian T.; Egan, Suhelen

2016-01-01

Cyanobacteria are among the first microorganisms to have inhabited the Earth. Throughout the last few billion years, they have played a major role in shaping the Earth as the planet we live in, and they continue to play a significant role in our everyday lives. Besides being an essential source of atmospheric oxygen, marine cyanobacteria are prolific secondary metabolite producers, often despite the exceptionally small genomes. Secondary metabolites produced by these organisms are diverse and complex; these include compounds, such as pigments and fluorescent dyes, as well as biologically-active compounds with a particular interest for the pharmaceutical industry. Cyanobacteria are currently regarded as an important source of nutrients and biofuels and form an integral part of novel innovative energy-efficient designs. Being autotrophic organisms, cyanobacteria are well suited for large-scale biotechnological applications due to the low requirements for organic nutrients. Recent advances in molecular biology techniques have considerably enhanced the potential for industries to optimize the production of cyanobacteria secondary metabolites with desired functions. This manuscript reviews the environmental role of marine cyanobacteria with a particular focus on their secondary metabolites and discusses current and future developments in both the production of desired cyanobacterial metabolites and their potential uses in future innovative projects. PMID:27196915

Tiny Microbes with a Big Impact: The Role of Cyanobacteria and Their Metabolites in Shaping Our Future.

PubMed

Mazard, Sophie; Penesyan, Anahit; Ostrowski, Martin; Paulsen, Ian T; Egan, Suhelen

2016-05-17

Cyanobacteria are among the first microorganisms to have inhabited the Earth. Throughout the last few billion years, they have played a major role in shaping the Earth as the planet we live in, and they continue to play a significant role in our everyday lives. Besides being an essential source of atmospheric oxygen, marine cyanobacteria are prolific secondary metabolite producers, often despite the exceptionally small genomes. Secondary metabolites produced by these organisms are diverse and complex; these include compounds, such as pigments and fluorescent dyes, as well as biologically-active compounds with a particular interest for the pharmaceutical industry. Cyanobacteria are currently regarded as an important source of nutrients and biofuels and form an integral part of novel innovative energy-efficient designs. Being autotrophic organisms, cyanobacteria are well suited for large-scale biotechnological applications due to the low requirements for organic nutrients. Recent advances in molecular biology techniques have considerably enhanced the potential for industries to optimize the production of cyanobacteria secondary metabolites with desired functions. This manuscript reviews the environmental role of marine cyanobacteria with a particular focus on their secondary metabolites and discusses current and future developments in both the production of desired cyanobacterial metabolites and their potential uses in future innovative projects.

Redundant synthesis of a conidial polyketide by two distinct secondary metabolite clusters in Aspergillus fumigatus

PubMed Central

Throckmorton, Kurt; Lim, Fang Yun; Kontoyiannis, Dimitrios P.; Zheng, Weifa; Keller, Nancy P.

2016-01-01

Summary Filamentous fungi are renowned for the production of bioactive secondary metabolites. Typically, one distinct metabolite is generated from a specific secondary metabolite cluster. Here, we characterize the newly described trypacidin (tpc) cluster in the opportunistic human pathogen Aspergillus fumigatus. We find that this cluster as well as the previously characterized endocrocin (enc) cluster both contribute to the production of the spore metabolite endocrocin. Whereas trypacidin is eliminated when only tpc cluster genes are deleted, endocrocin production is only eliminated when both the tpc and enc non-reducing polyketide synthase-encoding genes, tpcC and encA, respectively, are deleted. EncC, an anthrone oxidase, converts the product released from EncA to endocrocin as a final product. In contrast, endocrocin synthesis by the tpc cluster likely results from incomplete catalysis by TpcK (a putative decarboxylase), as its deletion results in a nearly 10-fold increase in endocrocin production. We suggest endocrocin is likely a shunt product in all related non-reducing polyketide synthase clusters containing homologues of TpcK and TpcL (a putative anthrone oxidase), e.g. geodin and monodictyphenone. This finding represents an unusual example of two physically discrete secondary metabolite clusters generating the same natural product in one fungal species by distinct routes. PMID:26242966

Influence of colour type and previous cultivation on secondary metabolites in hypocotyls and leaves of maca (Lepidium meyenii Walpers).

PubMed

Clément, Céline; Diaz Grados, Diego A; Avula, Bharathi; Khan, Ihklas A; Mayer, Andrea C; Ponce Aguirre, Dante D; Manrique, Ivan; Kreuzer, Michael

2010-04-15

Maca is an Andean crop of the Brassicaceae family which is mainly known for its fertility-enhancing properties following consumption. The hypocotyls display various colours ranging from white to black. Each colour has different biological effects. The aim of this study was to analyse the concentrations of major secondary metabolites in hypocotyls and leaves of maca in a controlled planting experiment in the Peruvian Andes at 4130 m above sea level. The effects of colour type and of previous cultivation of the field were examined. In the hypocotyls, the colour type effect was significant for most secondary metabolites; exceptions were beta-sitosterol and campesterol. The lead-coloured, yellow and violet maca hypocotyls were rich in glucosinolates, macaene and macamides, respectively. Previous cultivation affected macaene, campesterol and indole glucosinolate concentrations. Effects on metabolite concentrations in the leaves were minor. Hypocotyls were richer in macaene, macamides and glucosinolates than were leaves, and were poorer in beta-sitosterol and total phenols. Colour type has to be considered in maca production, as colour associates with variations in concentrations of distinct bioactive metabolites. Leaves may be interesting for animal nutrition purposes as they contain essentially the same secondary metabolites as the hypocotyls but in clearly lower concentrations. (c) 2010 Society of Chemical Industry.

Natural Products from Marine Fungi—Still an Underrepresented Resource

PubMed Central

Imhoff, Johannes F.

2016-01-01

Marine fungi represent a huge potential for new natural products and an increased number of new metabolites have become known over the past years, while much of the hidden potential still needs to be uncovered. Representative examples of biodiversity studies of marine fungi and of natural products from a diverse selection of marine fungi from the author’s lab are highlighting important aspects of this research. If one considers the huge phylogenetic diversity of marine fungi and their almost ubiquitous distribution, and realizes that most of the published work on secondary metabolites of marine fungi has focused on just a few genera, strictly speaking Penicillium, Aspergillus and maybe also Fusarium and Cladosporium, the diversity of marine fungi is not adequately represented in investigations on their secondary metabolites and the less studied species deserve special attention. In addition to results on recently discovered new secondary metabolites of Penicillium species, the diversity of fungi in selected marine habitats is highlighted and examples of groups of secondary metabolites produced by representatives of a variety of different genera and their bioactivities are presented. Special focus is given to the production of groups of derivatives of metabolites by the fungi and to significant differences in biological activities due to small structural changes. PMID:26784209

Secondary metabolism in the lichen symbiosis.

PubMed

Calcott, Mark J; Ackerley, David F; Knight, Allison; Keyzers, Robert A; Owen, Jeremy G

2018-03-05

Lichens, which are defined by a core symbiosis between a mycobiont (fungal partner) and a photobiont (photoautotrophic partner), are in fact complex assemblages of microorganisms that constitute a largely untapped source of bioactive secondary metabolites. Historically, compounds isolated from lichens have predominantly been those produced by the dominant fungal partner, and these continue to be of great interest for their unique chemistry and biotechnological potential. In recent years it has become apparent that many photobionts and lichen-associated bacteria also produce a range of potentially valuable molecules. There is evidence to suggest that the unique nature of the symbiosis has played a substantial role in shaping many aspects of lichen chemistry, for example driving bacteria to produce metabolites that do not bring them direct benefit but are useful to the lichen as a whole. This is most evident in studies of cyanobacterial photobionts, which produce compounds that differ from free living cyanobacteria and are unique to symbiotic organisms. The roles that these and other lichen-derived molecules may play in communication and maintaining the symbiosis are poorly understood at present. Nonetheless, advances in genomics, mass spectrometry and other analytical technologies are continuing to illuminate the wealth of biological and chemical diversity present within the lichen holobiome. Implementation of novel biodiscovery strategies such as metagenomic screening, coupled with synthetic biology approaches to reconstitute, re-engineer and heterologously express lichen-derived biosynthetic gene clusters in a cultivable host, offer a promising means for tapping into this hitherto inaccessible wealth of natural products.

Accumulation of flavonoids and related compounds in birch induced by UV-B irradiance.

PubMed

Lavola, Anu

1998-01-01

A growth chamber experiment was conducted to examine the effects of UV-B exposure (4.9 kJ m(-2) day(-1) of biologically effective UV-B, 280-320 nm) on shoot growth and secondary metabolite production in Betula pendula (Roth) and B. resinifera (Britt.) seedlings originating from environments in Finland, Germany and Alaska differing in solar UV-B radiation and climate. Neither shoot growth nor the composition of secondary metabolites was affected by UV-B irradiance, but the treatment induced significant changes in the amounts of individual secondary metabolites in leaves. Leaves of seedlings exposed to UV-B radiation contained higher concentrations of several flavonoids, condensed tannins and some hydroxycinnamic acids than leaves of control seedlings that received no UV-B radiation. At the population level, there was considerable variation in secondary metabolite responses to UV-B radiation: among populations, the induced response was most prominent in Alaskan populations, which were adapted to the lowest ambient UV-B radiation environment. I conclude that solar UV-B radiation plays an important role in the formation of secondary chemical characteristics in birch trees.

Phytochemical characterization and biological activity of secondary metabolites from three Limonium species

USDA-ARS?s Scientific Manuscript database

Plant tissues typically contain a diverse complement of secondary metabolites that provide protection against various biotic and abiotic hazards. Chemical similarities are commonly used to interpret phylogenetic relationships among plant taxa. The comparative phytochemical constituents of three Limo...

Comparative genomic analysis of secondary metabolite biosynthetic gene clusters in 207 isolates of Fusarium

USDA-ARS?s Scientific Manuscript database

Fusarium species are known for their ability to produce secondary metabolites (SMs), including plant hormones, pigments, mycotoxins, and other compounds with potential agricultural, pharmaceutical, and biotechnological impact. Understanding the distribution of SM biosynthetic gene clusters across th...

Development and Testing of Secondary Metabolism Mutants of Pseudomonas fluorescens PF-5

USDA-ARS?s Scientific Manuscript database

Pseudomonas fluorescens Pf-5, a biological control agent of soil-borne plant diseases, produces at least ten secondary metabolites. Several of these metabolites, including hydrogen cyanide, pyrrolnitrin, pyoluteorin and 2,4-diacetylphloroglucinol have well-characterized roles in biological control. ...

Molecular genetics of secondary chemistry in Metarhizium fungi

USDA-ARS?s Scientific Manuscript database

As with many microbes, entomopathogenic fungi from the genus Metarhizium produce a plethora of small molecule metabolites, often referred to as secondary metabolites. Although these intriguing compounds are a conspicuous feature of the biology of the producing fungi, their roles in pathogenicity and...

Role of secondary metabolites/antioxidants in vitro

USDA-ARS?s Scientific Manuscript database

In literature, secondary metabolites are described as natural products, waste, phytopharmaceuticals, bioactive constituents or by-products of the primary metabolism. They occur in many plant genera and microorganisms in vivo and in vitro, and have complex chemical structures specific to the plants w...

Production and characterization of bioactive metabolites from piezotolerant deep sea fungus Nigrospora sp. in submerged fermentation.

PubMed

Arumugam, G K; Srinivasan, S K; Joshi, G; Gopal, D; Ramalingam, K

2015-01-01

To produce and characterize bioactive metabolites from piezotolerant marine fungus Nigrospora sp. in submerged fermentation. A distinct marine strain, Nigrospora sp. NIOT has been isolated from a depth of 800 m at the Arabian Sea. The 18S rRNA and internal transcribed spacers (ITS) analysis demonstrates its close association with the genus Nigrospora. Effect of pH, temperature, salinity, carbon source and amino acids was studied to optimize the fermentation conditions. Optimal mycelia growth and secondary metabolites production were observed at 6·0-8·0 pH, 20-30°C temperature, 7·5% salinity, sucrose as carbon source and tryptophan as amino acid source. The extracellular secondary metabolites exhibited high antimicrobial activities against both gram-positive and gram-negative pathogenic bacteria with minimal inhibitory concentration (MIC) values higher than 30 μg ml(-1). Strongest cytotoxicity was observed in all cell lines tested, GI50 (growth inhibition by 50%) was calculated to be 1·35, 3·2, 0·13 and 0·35 μg ml(-1) against U937, MCF-7, A673 and Jurkat, respectively. Fourier transform infrared spectroscopy (FTIR) and gas chromatography-mass spectrometry (GC-MS) analyses of secondary metabolites confirmed the production of antimicrobial and anticancer substances. A piezotolerant fungus Nigrospora sp. NIOT isolated from deep sea environment was successfully cultured under submerged fermentation. The secondary metabolites produced from this organism showed potent antimicrobial and anticancer activities with immediate application to cosmetics and pharmaceutical industries. This is the first study exploring Nigrospora sp. from 800 m in marine environment. This deep sea fungus under optimized culture conditions effectively produced bioactive secondary metabolites such as griseofulvin, spirobenzofuran and pyrone derivatives at higher concentrations. © 2014 The Society for Applied Microbiology.

Flavonoids: biosynthesis, biological functions, and biotechnological applications

PubMed Central

Falcone Ferreyra, María L.; Rius, Sebastián P.; Casati, Paula

2012-01-01

Flavonoids are widely distributed secondary metabolites with different metabolic functions in plants. The elucidation of the biosynthetic pathways, as well as their regulation by MYB, basic helix-loop-helix (bHLH), and WD40-type transcription factors, has allowed metabolic engineering of plants through the manipulation of the different final products with valuable applications. The present review describes the regulation of flavonoid biosynthesis, as well as the biological functions of flavonoids in plants, such as in defense against UV-B radiation and pathogen infection, nodulation, and pollen fertility. In addition, we discuss different strategies and achievements through the genetic engineering of flavonoid biosynthesis with implication in the industry and the combinatorial biosynthesis in microorganisms by the reconstruction of the pathway to obtain high amounts of specific compounds. PMID:23060891

Recombinant organisms for production of industrial products.

PubMed

Adrio, Jose-Luis; Demain, Arnold L

2010-01-01

A revolution in industrial microbiology was sparked by the discoveries of ther double-stranded structure of DNA and the development of recombinant DNA technology. Traditional industrial microbiology was merged with molecular biology to yield improved recombinant processes for the industrial production of primary and secondary metabolites, protein biopharmaceuticals and industrial enzymes. Novel genetic techniques such as metabolic engineering, combinatorial biosynthesis and molecular breeding techniques and their modifications are contributing greatly to the development of improved industrial processes. In addition, functional genomics, proteomics and metabolomics are being exploited for the discovery of novel valuable small molecules for medicine as well as enzymes for catalysis. The sequencing of industrial microbal genomes is being carried out which bodes well for future process improvement and discovery of new industrial products. © 2010 Landes Bioscience

Current Trends and Potential Applications of Microbial Interactions for Human Welfare

PubMed Central

Tshikantwa, Tiroyaone Shimane; Ullah, Muhammad Wajid; He, Feng; Yang, Guang

2018-01-01

For a long time, it was considered that interactions between microbes are only inhibitory in nature. However, latest developments in research have demonstrated that within our environment, several classes of microbes exist which produce different products upon interaction and thus embrace a wider scope of useful and potentially valuable aspects beyond simple antibiosis. Therefore, the current review explores different types of microbial interactions and describes the role of various physical, chemical, biological, and genetic factors regulating such interactions. It further explains the mechanism of action of biofilm formation and role of secondary metabolites regulating bacteria-fungi interaction. Special emphasis and focus is placed on microbial interactions which are important in medicine, food industry, agriculture, and environment. In short, this review reveals the recent contributions of microbial interaction for the benefit of mankind.

Sub-lethal levels of electric current elicit the biosynthesis of plant secondary metabolites.

PubMed

Kaimoyo, Evans; Farag, Mohamed A; Sumner, Lloyd W; Wasmann, Catherine; Cuello, Joel L; VanEtten, Hans

2008-01-01

Many secondary metabolites that are normally undetectable or in low amounts in healthy plant tissue are synthesized in high amounts in response to microbial infection. Various abiotic and biotic agents have been shown to mimic microorganisms and act as elicitors of the synthesis of these plant compounds. In the present study, sub-lethal levels of electric current are shown to elicit the biosynthesis of secondary metabolites in transgenic and non-transgenic plant tissue. The production of the phytoalexin (+)-pisatin by pea was used as the main model system. Non-transgenic pea hairy roots treated with 30-100 mA of electric current produced 13 times higher amounts of (+)-pisatin than did the non-elicited controls. Electrically elicited transgenic pea hairy root cultures blocked at various enzymatic steps in the (+)-pisatin biosynthetic pathway also accumulated intermediates preceding the blocked enzymatic step. Secondary metabolites not usually produced by pea accumulated in some of the transgenic root cultures after electric elicitation due to the diversion of the intermediates into new pathways. The amount of pisatin in the medium bathing the roots of electro-elicited roots of hydroponically cultivated pea plants was 10 times higher 24 h after elicitation than in the medium surrounding the roots of non-elicited control plants, showing not only that the electric current elicited (+)-pisatin biosynthesis but also that the (+)-pisatin was released from the roots. Seedlings, intact roots or cell suspension cultures of fenugreek (Trigonella foenum-graecum), barrel medic, (Medicago truncatula), Arabidopsis thaliana, red clover (Trifolium pratense) and chickpea (Cicer arietinum) also produced increased levels of secondary metabolites in response to electro-elicitation. On the basis of our results, electric current would appear to be a general elicitor of plant secondary metabolites and to have potential for application in both basic and commercial research.

Intrapopulation Genotypic Variation of Foliar Secondary Chemistry during Leaf Senescence and Litter Decomposition in Silver Birch (Betula pendula)

PubMed Central

Paaso, Ulla; Keski-Saari, Sarita; Keinänen, Markku; Karvinen, Heini; Silfver, Tarja; Rousi, Matti; Mikola, Juha

2017-01-01

Abundant secondary metabolites, such as condensed tannins, and their interpopulation genotypic variation can remain through plant leaf senescence and affect litter decomposition. Whether the intrapopulation genotypic variation of a more diverse assortment of secondary metabolites equally persists through leaf senescence and litter decomposition is not well understood. We analyzed concentrations of intracellular phenolics, epicuticular flavonoid aglycones, epicuticular triterpenoids, condensed tannins, and lignin in green leaves, senescent leaves and partly decomposed litter of silver birch, Betula pendula. Broad-sense heritability (H2) and coefficient of genotypic variation (CVG) were estimated for metabolites in senescent leaves and litter using 19 genotypes selected from a B. pendula population in southern Finland. We found that most of the secondary metabolites remained through senescence and decomposition and that their persistence was related to their chemical properties. Intrapopulation H2 and CVG for intracellular phenolics, epicuticular flavonoid aglycones and condensed tannins were high and remarkably, increased from senescent leaves to decomposed litter. The rank of genotypes in metabolite concentrations was persistent through litter decomposition. Lignin was an exception, however, with a diminishing genotypic variation during decomposition, and the concentrations of lignin and condensed tannins had a negative genotypic correlation in the senescent leaves. Our results show that secondary metabolites and their intrapopulation genotypic variation can for the most part remain through leaf senescence and early decomposition, which is a prerequisite for initial litter quality to predict variation in litter decomposition rates. Persistent genotypic variation also opens an avenue for selection to impact litter decomposition in B. pendula populations through acting on their green foliage secondary chemistry. The negative genotypic correlations and diminishing heritability of lignin concentrations may, however, counteract this process. PMID:28694813

Intrapopulation Genotypic Variation of Foliar Secondary Chemistry during Leaf Senescence and Litter Decomposition in Silver Birch (Betula pendula).

PubMed

Paaso, Ulla; Keski-Saari, Sarita; Keinänen, Markku; Karvinen, Heini; Silfver, Tarja; Rousi, Matti; Mikola, Juha

2017-01-01

Abundant secondary metabolites, such as condensed tannins, and their interpopulation genotypic variation can remain through plant leaf senescence and affect litter decomposition. Whether the intrapopulation genotypic variation of a more diverse assortment of secondary metabolites equally persists through leaf senescence and litter decomposition is not well understood. We analyzed concentrations of intracellular phenolics, epicuticular flavonoid aglycones, epicuticular triterpenoids, condensed tannins, and lignin in green leaves, senescent leaves and partly decomposed litter of silver birch, Betula pendula . Broad-sense heritability ( H 2 ) and coefficient of genotypic variation ( CV G ) were estimated for metabolites in senescent leaves and litter using 19 genotypes selected from a B. pendula population in southern Finland. We found that most of the secondary metabolites remained through senescence and decomposition and that their persistence was related to their chemical properties. Intrapopulation H 2 and CV G for intracellular phenolics, epicuticular flavonoid aglycones and condensed tannins were high and remarkably, increased from senescent leaves to decomposed litter. The rank of genotypes in metabolite concentrations was persistent through litter decomposition. Lignin was an exception, however, with a diminishing genotypic variation during decomposition, and the concentrations of lignin and condensed tannins had a negative genotypic correlation in the senescent leaves. Our results show that secondary metabolites and their intrapopulation genotypic variation can for the most part remain through leaf senescence and early decomposition, which is a prerequisite for initial litter quality to predict variation in litter decomposition rates. Persistent genotypic variation also opens an avenue for selection to impact litter decomposition in B. pendula populations through acting on their green foliage secondary chemistry. The negative genotypic correlations and diminishing heritability of lignin concentrations may, however, counteract this process.

Characterization of fungi in office dust: Comparing results of microbial secondary metabolites, fungal internal transcribed spacer region sequencing, viable culture and other microbial indices.

PubMed

Park, J-H; Sulyok, M; Lemons, A R; Green, B J; Cox-Ganser, J M

2018-05-04

Recent developments in molecular and chemical methods have enabled the analysis of fungal DNA and secondary metabolites, often produced during fungal growth, in environmental samples. We compared 3 fungal analytical methods by analysing floor dust samples collected from an office building for fungi using viable culture, internal transcribed spacer (ITS) sequencing and secondary metabolites using liquid chromatography-tandem mass spectrometry. Of the 32 metabolites identified, 29 had a potential link to fungi with levels ranging from 0.04 (minimum for alternariol monomethylether) to 5700 ng/g (maximum for neoechinulin A). The number of fungal metabolites quantified per sample ranged from 8 to 16 (average = 13/sample). We identified 216 fungal operational taxonomic units (OTUs) with the number per sample ranging from 6 to 29 (average = 18/sample). We identified 37 fungal species using culture, and the number per sample ranged from 2 to 13 (average = 8/sample). Agreement in identification between ITS sequencing and culturing was weak (kappa = -0.12 to 0.27). The number of cultured fungal species poorly correlated with OTUs, which did not correlate with the number of metabolites. These suggest that using multiple measurement methods may provide an improved understanding of fungal exposures in indoor environments and that secondary metabolites may be considered as an additional source of exposure. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

ABA and GA3 regulate the synthesis of primary and secondary metabolites related to alleviation from biotic and abiotic stresses in grapevine.

PubMed

Murcia, Germán; Fontana, Ariel; Pontin, Mariela; Baraldi, Rita; Bertazza, Gianpaolo; Piccoli, Patricia N

2017-03-01

Plants are able to synthesize a large number of organic compounds. Among them, primary metabolites are known to participate in plant growth and development, whereas secondary metabolites are mostly involved in defense and other facultative processes. In grapevine, one of the major fruit crops in the world, secondary metabolites, mainly polyphenols, are of great interest for the wine industry. Even though there is an extensive literature on the content and profile of those compounds in berries, scarce or no information is available regarding polyphenols in other organs. In addition, little is known about the effect of plant growth regulators (PGRs), ABA and GA 3 (extensively used in table grapes) on the synthesis of primary and secondary metabolites in wine grapes. In table grapes, cultural practices include the use of GA 3 sprays shortly before veraison, to increase berry and bunch size, and sugar content in fruits. Meanwhile, ABA applications to the berries on pre-veraison improve the skin coloring and sugar accumulation, anticipating the onset of veraison. Accordingly, the aim of this study was to assess and characterize primary and secondary metabolites in leaves, berries and roots of grapevine plants cv. Malbec at veraison, and changes in compositions after ABA and GA 3 aerial sprayings. Metabolic profiling was conducted using GC-MS, GC-FID and HPLC-MWD. A large set of metabolites was identified: sugars, alditols, organic acids, amino acids, polyphenols (flavonoids and non-flavonoids) and terpenes (mono-, sesqui-, di- and triterpenes). The obtained results showed that ABA applications elicited synthesis of mono- and sesquiterpenes in all assessed tissues, as well as L-proline, acidic amino acids and anthocyanins in leaves. Additionally, applications with GA 3 elicited synthesis of L-proline in berries, and mono- and sesquiterpenes in all the tissues. However, treatment with GA 3 seemed to block polyphenol synthesis, mainly in berries. In conclusion, ABA and GA 3 applications to grapevine plants cv. Malbec influenced the synthesis of primary and secondary metabolites known to be essential for coping with biotic and abiotic stresses. Copyright © 2016 Elsevier Ltd. All rights reserved.

Distribution of secondary metabolite biosynthetic gene clusters in 343 Fusarium genomes

USDA-ARS?s Scientific Manuscript database

Fusarium consists of over 200 phylogenetically distinct species, many of which cause important crop diseases and/or produce mycotoxins and other secondary metabolites (SMs). Some fusaria also cause opportunistic infections in humans and other animals. To investigate the distribution of biosynthetic ...

Regulation of cytochrome P450 mRNA expression in primary porcine hepatocytes by selected secondary plant metabolites from chicory (Cichorium intybus L.).

PubMed

Rasmussen, Martin Krøyer; Klausen, Christina Lindgaard; Ekstrand, Bo

2014-03-01

Chicory (Cichorium intybus) has been shown to induce enzymes of pharmacokinetic relevance (cytochrome P450; CYP). The aim of this study was to investigate the effects of selected secondary plant metabolites with a global extract of chicory root, on the expression of hepatic CYP mRNA (1A2, 2A19, 2C33, 2D25, 2E1 and 3A29), using primary porcine hepatocytes. Of the tested secondary plant metabolites, artemisinin, scoparone, lactucin and esculetin all induced increased expression of specific CYPs, while esculin showed no effect. In contrast, a global extract of chicory root decreased the expression of CYP1A2, 2C33, 2D25 and 3A29 at high concentrations. The results suggest that purified secondary metabolites from chicory affect CYP expression and thereby might affect detoxification in general, and that global extracts of plants can have effects different from individual components. Copyright © 2013 Elsevier Ltd. All rights reserved.

Small-molecule elicitation of microbial secondary metabolites.

PubMed

Pettit, Robin K

2011-07-01

Microbial natural products continue to be an unparalleled resource for pharmaceutical lead discovery, but the rediscovery rate is high. Bacterial and fungal sequencing studies indicate that the biosynthetic potential of many strains is much greater than that observed by fermentation. Prodding the expression of such silent (cryptic) pathways will allow us to maximize the chemical diversity available from microorganisms. Cryptic metabolic pathways can be accessed in the laboratory using molecular or cultivation-based approaches. A targeted approach related to cultivation-based methods is the application of small-molecule elicitors to specifically affect transcription of secondary metabolite gene clusters. With the isolation of the novel secondary metabolites lunalides A and B, oxylipins, cladochromes F and G, nygerone A, chaetoglobosin-542, -540 and -510, sphaerolone, dihydrosphaerolone, mutolide and pestalone, and the enhanced production of known secondary metabolites like penicillin and bacitracin, chemical elicitation is proving to be an effective way to augment natural product libraries. © 2010 The Authors. Journal compilation © 2010 Society for Applied Microbiology and Blackwell Publishing Ltd.

Comparative mass spectrometry-based metabolomics strategies for the investigation of microbial secondary metabolites.

PubMed

Covington, Brett C; McLean, John A; Bachmann, Brian O

2017-01-04

Covering: 2000 to 2016The labor-intensive process of microbial natural product discovery is contingent upon identifying discrete secondary metabolites of interest within complex biological extracts, which contain inventories of all extractable small molecules produced by an organism or consortium. Historically, compound isolation prioritization has been driven by observed biological activity and/or relative metabolite abundance and followed by dereplication via accurate mass analysis. Decades of discovery using variants of these methods has generated the natural pharmacopeia but also contributes to recent high rediscovery rates. However, genomic sequencing reveals substantial untapped potential in previously mined organisms, and can provide useful prescience of potentially new secondary metabolites that ultimately enables isolation. Recently, advances in comparative metabolomics analyses have been coupled to secondary metabolic predictions to accelerate bioactivity and abundance-independent discovery work flows. In this review we will discuss the various analytical and computational techniques that enable MS-based metabolomic applications to natural product discovery and discuss the future prospects for comparative metabolomics in natural product discovery.

Recent advances in genes involved in secondary metabolite synthesis, hyphal development, energy metabolism and pathogenicity in Fusarium graminearum (teleomorph Gibberella zeae).

PubMed

Geng, Zongyi; Zhu, Wei; Su, Hao; Zhao, Yong; Zhang, Ke-Qin; Yang, Jinkui

2014-01-01

The ascomycete fungus, Fusarium graminearum (teleomorph Gibberella zeae), is the most common causal agent of Fusarium head blight (FHB), a devastating disease for cereal crops worldwide. F. graminearum produces ascospores (sexual spores) and conidia (asexual spores), which can serve as disease inocula of FHB. Meanwhile, Fusarium-infected grains are often contaminated with mycotoxins such as trichothecenes (TRIs), fumonisins, and zearalenones, among which TRIs are related to the pathogenicity of F. graminearum, and these toxins are hazardous to humans and livestock. In recent years, with the complete genome sequencing of F. graminearum, an increasing number of functional genes involved in the production of secondary metabolites, hyphal differentiation, sexual and asexual reproduction, virulence and pathogenicity have been identified from F. graminearum. In this review, the secondary metabolite synthesis, hyphal development and pathogenicity related genes in F. graminearum were thoroughly summarized, and the genes associated with secondary metabolites, sexual reproduction, energy metabolism, and pathogenicity were highlighted. Copyright © 2013 Elsevier Inc. All rights reserved.

Enhancer binding proteins act as hetero-oligomers and link secondary metabolite production to myxococcal development, motility, and predation.

PubMed

Volz, Carsten; Kegler, Carsten; Müller, Rolf

2012-11-21

Motile predatory Myxobacteria are producers of multiple secondary metabolites and, on starvation, undergo concerted cellular differentiation to form multicellular fruiting bodies. These abilities demand myxobacterial genomes to encode sophisticated regulatory networks that are not satisfactorily understood. Here, we present two bacterial enhancer binding proteins (bEBPs) encoded in Myxococcus xanthus acting as direct regulators of secondary metabolites intriguingly exhibiting activating and inhibitory effects. Elucidation of a regulon for each bEBP enabled us to unravel their role in myxococcal development, predation, and motility. Interestingly, both bEBPs are able to interact by forming a hetero-oligomeric complex. Our findings represent an alternative mode of operation of bEBPs, which are currently thought to enhance promoter activity by acting as homo-oligomers. Furthermore, a direct link between secondary metabolite gene expression and predation, motility, and cellular development could be shown for the first time. Copyright © 2012 Elsevier Ltd. All rights reserved.

Ecotype variability in growth and secondary metabolite profile in Moringa oleifera: impact of sulfur and water availability.

PubMed

Förster, Nadja; Ulrichs, Christian; Schreiner, Monika; Arndt, Nick; Schmidt, Reinhard; Mewis, Inga

2015-03-25

Moringa oleifera is widely cultivated in plantations in the tropics and subtropics. Previous cultivation studies with M. oleifera focused primarily only on leaf yield. In the present study, the content of potentially health-promoting secondary metabolites (glucosinolates, phenolic acids, and flavonoids) were also investigated. Six different ecotypes were grown under similar environmental conditions to identify phenotypic differences that can be traced back to the genotype. The ecotypes TOT4880 (origin USA) and TOT7267 (origin India) were identified as having the best growth performance and highest secondary metabolite production, making them an ideal health-promoting food crop. Furthermore, optimal cultivation conditions-exemplarily on sulfur fertilization and water availability-for achieving high leaf and secondary metabolite yields were investigated for M. oleifera. In general, plant biomass and height decreased under water deficiency compared to normal cultivation conditions, whereas the glucosinolate content increased. The effects depended to a great extent on the ecotype.

Secondary metabolites profiles and antioxidant activities of germinated brown and red rice

NASA Astrophysics Data System (ADS)

Nurnaistia, Y.; Aisyah, S.; Munawaroh, H. S. H.; Zackiyah

2018-05-01

The research aims to investigate the effect of germination on the secondary metabolite profiles and antioxidant activity of brown and red rice. The germination was performed by using a simple laboratory-scale machine that was designed and optimized to provide conditions that support the germination process. The germination was carried out for 2 days in dark conditions at 26°C and 99% humidity. Analysis of the secondary metabolite profile of ungerminated and germinated rice was performed using LC-MS. The antioxidant activities of ungerminated and germinated rice were done by using DPPH method. The results showed that the profiles of secondary metabolites of brown and red rice changed after germination. Some peaks were found to be induced in the germinated rice. However, some peaks were also loss during germination. The antioxidant activity of brown rice was slightly increased due to the germination, from 11.2% to 22.5%. Meanwhile the antioxidant activity of red rice was decreased after germination, from 73.8% to 60.0%.

Major secondary metabolites produced by two commercial Trichoderma strains active against different phytopathogens.

PubMed

Vinale, F; Marra, R; Scala, F; Ghisalberti, E L; Lorito, M; Sivasithamparam, K

2006-08-01

Trichoderma harzianum strains T22 and T39 are two micro-organisms used as active agents in a variety of commercial biopesticides and biofertilizers and widely applied amongst field and greenhouse crops. The production, isolation, biological and chemical characterization of the main secondary metabolites produced by these strains are investigated. Of the three major compounds produced by strain T22, one is a new azaphilone that shows marked in vitro inhibition of Rhizoctonia solani, Pythium ultimum and Gaeumannomyces graminis var. tritici. In turn, filtrates from strain T39 were demonstrated to contain two compounds previously isolated from other T. harzianum strains and a new butenolide. The production of the isolated metabolites was also monitored by liquid chromatography/mass spectrometry during in vitro interaction with R. solani. This paper reports the isolation and characterization of the main secondary metabolites obtained from culture filtrates of two T. harzianum strains and their production during antagonistic interaction with the pathogen R. solani. This is the first work on secondary metabolites produced by the commercially applied strains T22 and T39. Our results provide a better understanding of the metabolism of these fungi, which are both widely used as biopesticides and/or biofertilizers in biocontrol.

Novel Approach to Classify Plants Based on Metabolite-Content Similarity.

PubMed

Liu, Kang; Abdullah, Azian Azamimi; Huang, Ming; Nishioka, Takaaki; Altaf-Ul-Amin, Md; Kanaya, Shigehiko

2017-01-01

Secondary metabolites are bioactive substances with diverse chemical structures. Depending on the ecological environment within which they are living, higher plants use different combinations of secondary metabolites for adaptation (e.g., defense against attacks by herbivores or pathogenic microbes). This suggests that the similarity in metabolite content is applicable to assess phylogenic similarity of higher plants. However, such a chemical taxonomic approach has limitations of incomplete metabolomics data. We propose an approach for successfully classifying 216 plants based on their known incomplete metabolite content. Structurally similar metabolites have been clustered using the network clustering algorithm DPClus. Plants have been represented as binary vectors, implying relations with structurally similar metabolite groups, and classified using Ward's method of hierarchical clustering. Despite incomplete data, the resulting plant clusters are consistent with the known evolutional relations of plants. This finding reveals the significance of metabolite content as a taxonomic marker. We also discuss the predictive power of metabolite content in exploring nutritional and medicinal properties in plants. As a byproduct of our analysis, we could predict some currently unknown species-metabolite relations.

Novel Approach to Classify Plants Based on Metabolite-Content Similarity

PubMed Central

Abdullah, Azian Azamimi; Huang, Ming; Nishioka, Takaaki

2017-01-01

Secondary metabolites are bioactive substances with diverse chemical structures. Depending on the ecological environment within which they are living, higher plants use different combinations of secondary metabolites for adaptation (e.g., defense against attacks by herbivores or pathogenic microbes). This suggests that the similarity in metabolite content is applicable to assess phylogenic similarity of higher plants. However, such a chemical taxonomic approach has limitations of incomplete metabolomics data. We propose an approach for successfully classifying 216 plants based on their known incomplete metabolite content. Structurally similar metabolites have been clustered using the network clustering algorithm DPClus. Plants have been represented as binary vectors, implying relations with structurally similar metabolite groups, and classified using Ward's method of hierarchical clustering. Despite incomplete data, the resulting plant clusters are consistent with the known evolutional relations of plants. This finding reveals the significance of metabolite content as a taxonomic marker. We also discuss the predictive power of metabolite content in exploring nutritional and medicinal properties in plants. As a byproduct of our analysis, we could predict some currently unknown species-metabolite relations. PMID:28164123

Chemical ecology of endophytic fungi: origins of secondary metabolites.

PubMed

Kusari, Souvik; Hertweck, Christian; Spiteller, Michael

2012-07-27

Endophytes constitute a remarkably multifarious group of microorganisms ubiquitous in plants and maintain an imperceptible association with their hosts for at least a part of their life cycle. Their enormous biological diversity coupled with their capability to biosynthesize bioactive secondary metabolites has provided the impetus for a number of investigations on endophytes. Here, we highlight the possible current and future strategies of understanding the chemical communication of endophytic fungi with other endophytes (fungi and bacteria) and with their host plants, which might not only allow the discovery and sustainable production of desirable natural products but also other mostly overlooked bioactive secondary metabolites. Copyright © 2012 Elsevier Ltd. All rights reserved.

Diversity of Secondary Metabolites from Marine Bacillus Species: Chemistry and Biological Activity

PubMed Central

Mondol, Muhammad Abdul Mojid; Shin, Hee Jae; Islam, Mohammad Tofazzal

2013-01-01

Marine Bacillus species produce versatile secondary metabolites including lipopeptides, polypeptides, macrolactones, fatty acids, polyketides, and isocoumarins. These structurally diverse compounds exhibit a wide range of biological activities, such as antimicrobial, anticancer, and antialgal activities. Some marine Bacillus strains can detoxify heavy metals through reduction processes and have the ability to produce carotenoids. The present article reviews the chemistry and biological activities of secondary metabolites from marine isolates. Side by side, the potential for application of these novel natural products from marine Bacillus strains as drugs, pesticides, carotenoids, and tools for the bioremediation of heavy metal toxicity are also discussed. PMID:23941823

Antagonistic roles of solanapyrone A during sporulation of the chickpea Ascochyta rabiei

USDA-ARS?s Scientific Manuscript database

Fungi are noted for production of a diverse array of secondary metabolites, many of which are of pharmacological importance. However, the biological roles of these molecules during the fungal life cycle in nature remain elusive. Solanapyrones are polyketide-derived secondary metabolites produced by ...

Evolutionary mechanisms involved in development of fungal secondary metabolite gene clusters

USDA-ARS?s Scientific Manuscript database

There is extensive adaptability and diversity in fungi, even among closely related species, that enable them to occupy various ecological niches. Of particular importance for niche adaptation is the production of fungal secondary metabolites (SM) because they can offer a distinct selective advantage...

Chemical transformations of characteristic hop secondary metabolites in relation to beer properties and the brewing process: a review.

PubMed

Steenackers, Bart; De Cooman, Luc; De Vos, Dirk

2015-04-01

The annual production of hops (Humulus lupulus L.) exceeds 100,000 mt and is almost exclusively consumed by the brewing industry. The value of hops is attributed to their characteristic secondary metabolites; these metabolites are precursors which are transformed during the brewing process into important bittering, aromatising and preservative components with rather low efficiency. By selectively transforming these components off-line, both their utilisation efficiency and functionality can be significantly improved. Therefore, the chemical transformations of these secondary metabolites will be considered with special attention to recent advances in the field. The considered components are the hop alpha-acids, hop beta-acids and xanthohumol, which are components unique to hops, and alpha-humulene and beta-caryophyllene, sesquiterpenes which are highly characteristic of hops. Copyright © 2014 Elsevier Ltd. All rights reserved.

Efflux systems in bacteria and their metabolic engineering applications.

PubMed

Jones, Christopher M; Hernández Lozada, Néstor J; Pfleger, Brian F

2015-11-01

The production of valuable chemicals from metabolically engineered microbes can be limited by excretion from the cell. Efflux is often overlooked as a bottleneck in metabolic pathways, despite its impact on alleviating feedback inhibition and product toxicity. In the past, it has been assumed that endogenous efflux pumps and membrane porins can accommodate product efflux rates; however, there are an increasing number of examples wherein overexpressing efflux systems is required to improve metabolite production. In this review, we highlight specific examples from the literature where metabolite export has been studied to identify unknown transporters, increase tolerance to metabolites, and improve the production capabilities of engineered bacteria. The review focuses on the export of a broad spectrum of valuable chemicals including amino acids, sugars, flavins, biofuels, and solvents. The combined set of examples supports the hypothesis that efflux systems can be identified and engineered to confer export capabilities on industrially relevant microbes.

Identification of the compositional changes in Orthosiphon stamineus leaves triggered by different drying techniques using 1 H NMR metabolomics.

PubMed

Pariyani, Raghunath; Ismail, Intan Safinar; Ahmad Azam, Amalina; Abas, Faridah; Shaari, Khozirah

2017-09-01

Java tea is a well-known herbal infusion prepared from the leaves of Orthosiphon stamineus (OS). The biological properties of tea are in direct correlation with the primary and secondary metabolite composition, which in turn largely depends on the choice of drying method. Herein, the impact of three commonly used drying methods, i.e. shade, microwave and freeze drying, on the metabolite composition and antioxidant activity of OS leaves was investigated using proton nuclear magnetic resonance ( 1 H NMR) spectroscopy combined with multivariate classification and regression analysis tools. A total of 31 constituents comprising primary and secondary metabolites belonging to the chemical classes of fatty acids, amino acids, sugars, terpenoids and phenolic compounds were identified. Shade-dried leaves were identified to possess the highest concentrations of bioactive secondary metabolites such as chlorogenic acid, caffeic acid, luteolin, orthosiphol and apigenin, followed by microwave-dried samples. Freeze-dried leaves had higher concentrations of choline, amino acids leucine, alanine and glutamine and sugars such as fructose and α-glucose, but contained the lowest levels of secondary metabolites. Metabolite profiling coupled with multivariate analysis identified shade drying as the best method to prepare OS leaves as Java tea or to include in traditional medicine preparation. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Establishing the Secondary Metabolite Profile of the Marine Fungus: Tolypocladium geodes sp. MF458 and Subsequent Optimisation of Bioactive Secondary Metabolite Production

PubMed Central

Kebede, Bethlehem; Wrigley, Stephen K.; Prashar, Anjali; Rahlff, Janina; Wolf, Markus; Reinshagen, Jeanette; Gribbon, Philip; Imhoff, Johannes F.; Silber, Johanna; Labes, Antje; Ellinger, Bernhard

2017-01-01

As part of an international research project, the marine fungal strain collection of the Helmholtz Centre for Ocean Research (GEOMAR) research centre was analysed for secondary metabolite profiles associated with anticancer activity. Strain MF458 was identified as Tolypocladium geodes, by internal transcribed spacer region (ITS) sequence similarity and its natural product production profile. By using five different media in two conditions and two time points, we were able to identify eight natural products produced by MF458. As well as cyclosporin A (1), efrapeptin D (2), pyridoxatin (3), terricolin A (4), malettinins B and E (5 and 6), and tolypocladenols A1/A2 (8), we identified a new secondary metabolite which we termed tolypocladenol C (7). All compounds were analysed for their anticancer potential using a selection of the NCI60 cancer cell line panel, with malettinins B and E (5 and 6) being the most promising candidates. In order to obtain sufficient quantities of these compounds to start preclinical development, their production was transferred from a static flask culture to a stirred tank reactor, and fermentation medium development resulted in a nearly eight-fold increase in compound production. The strain MF458 is therefore a producer of a number of interesting and new secondary metabolites and their production levels can be readily improved to achieve higher yields. PMID:28333084

Increasing carbon availability stimulates growth and secondary metabolites via modulation of phytohormones in winter wheat.

PubMed

Huang, Jianbei; Reichelt, Michael; Chowdhury, Somak; Hammerbacher, Almuth; Hartmann, Henrik

2017-02-01

Phytohormones play important roles in plant acclimation to changes in environmental conditions. However, their role in whole-plant regulation of growth and secondary metabolite production under increasing atmospheric CO2 concentrations ([CO2]) is uncertain but crucially important for understanding plant responses to abiotic stresses. We grew winter wheat (Triticum aestivum) under three [CO2] (170, 390, and 680 ppm) over 10 weeks, and measured gas exchange, relative growth rate (RGR), soluble sugars, secondary metabolites, and phytohormones including abscisic acid (ABA), auxin (IAA), jasmonic acid (JA), and salicylic acid (SA) at the whole-plant level. Our results show that, at the whole-plant level, RGR positively correlated with IAA but not ABA, and secondary metabolites positively correlated with JA and JA-Ile but not SA. Moreover, soluble sugars positively correlated with IAA and JA but not ABA and SA. We conclude that increasing carbon availability stimulates growth and production of secondary metabolites via up-regulation of auxin and jasmonate levels, probably in response to sugar-mediated signalling. Future low [CO2] studies should address the role of reactive oxygen species (ROS) in leaf ABA and SA biosynthesis, and at the transcriptional level should focus on biosynthetic and, in particular, on responsive genes involved in [CO2]-induced hormonal signalling pathways. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Impact of metal stress on the production of secondary metabolites in Pteris vittata L. and associated rhizosphere bacterial communities.

PubMed

Pham, Hoang Nam; Michalet, Serge; Bodillis, Josselin; Nguyen, Tien Dat; Nguyen, Thi Kieu Oanh; Le, Thi Phuong Quynh; Haddad, Mohamed; Nazaret, Sylvie; Dijoux-Franca, Marie-Geneviève

2017-07-01

Plants adapt to metal stress by modifying their metabolism including the production of secondary metabolites in plant tissues. Such changes may impact the diversity and functions of plant associated microbial communities. Our study aimed to evaluate the influence of metals on the secondary metabolism of plants and the indirect impact on rhizosphere bacterial communities. We then compared the secondary metabolites of the hyperaccumulator Pteris vittata L. collected from a contaminated mining site to a non-contaminated site in Vietnam and identified the discriminant metabolites. Our data showed a significant increase in chlorogenic acid derivatives and A-type procyanidin in plant roots at the contaminated site. We hypothesized that the intensive production of these compounds could be part of the antioxidant defense mechanism in response to metals. In parallel, the structure and diversity of bulk soil and rhizosphere communities was studied using high-throughput sequencing. The results showed strong differences in bacterial composition, characterized by the dominance of Proteobacteria and Nitrospira in the contaminated bulk soil, and the enrichment of some potential human pathogens, i.e., Acinetobacter, Mycobacterium, and Cupriavidus in P. vittata's rhizosphere at the mining site. Overall, metal pollution modified the production of P. vittata secondary metabolites and altered the diversity and structure of bacterial communities. Further investigations are needed to understand whether the plant recruits specific bacteria to adapt to metal stress.

Comparative genomics uncovers the prolific and distinctive metabolic potential of the cyanobacterial genus Moorea

PubMed Central

Leao, Tiago; Castelão, Guilherme; Monroe, Emily A.; Podell, Sheila; Glukhov, Evgenia; Allen, Eric E.; Gerwick, William H.; Gerwick, Lena

2017-01-01

Cyanobacteria are major sources of oxygen, nitrogen, and carbon in nature. In addition to the importance of their primary metabolism, some cyanobacteria are prolific producers of unique and bioactive secondary metabolites. Chemical investigations of the cyanobacterial genus Moorea have resulted in the isolation of over 190 compounds in the last two decades. However, preliminary genomic analysis has suggested that genome-guided approaches can enable the discovery of novel compounds from even well-studied Moorea strains, highlighting the importance of obtaining complete genomes. We report a complete genome of a filamentous tropical marine cyanobacterium, Moorea producens PAL, which reveals that about one-fifth of its genome is devoted to production of secondary metabolites, an impressive four times the cyanobacterial average. Moreover, possession of the complete PAL genome has allowed improvement to the assembly of three other Moorea draft genomes. Comparative genomics revealed that they are remarkably similar to one another, despite their differences in geography, morphology, and secondary metabolite profiles. Gene cluster networking highlights that this genus is distinctive among cyanobacteria, not only in the number of secondary metabolite pathways but also in the content of many pathways, which are potentially distinct from all other bacterial gene clusters to date. These findings portend that future genome-guided secondary metabolite discovery and isolation efforts should be highly productive. PMID:28265051

Secondary metabolite profiling of Alternaria dauci, A. porri, A. solani, and A. tomatophila.

PubMed

Andersen, Birgitte; Dongo, Anita; Pryor, Barry M

2008-02-01

Chemotaxonomy (secondary metabolite profiling) has been shown to be of great value in the classification and differentiation in Ascomycota. However, few studies have investigated the use of metabolite production for classification and identification purposes of plant pathogenic Alternaria species. The purpose of the present study was to describe the methodology behind metabolite profiling in chemotaxonomy using A. dauci, A. porri, A. solani, and A. tomatophila strains as examples of the group. The results confirmed that A. dauci, A. solani, and A. tomatophila are three distinct species each with their own specific metabolite profiles, and that A. solani and A. tomatophila both produce altersolanol A, altertoxin I, and macrosporin. By using automated chemical image analysis and other multivariate statistic analyses, three sets of species-specific metabolites could be selected, one each for A. dauci, A. solani, and A. tomatophila.

Plant secondary metabolites in alfalfa, birdsfoot trefoil, reed canarygrass, and tall fescue unaffected by two different nitrogen sources

USDA-ARS?s Scientific Manuscript database

Plant secondary metabolites (PSM) may increase the sustainability of agriculture systems by reducing inputs, as PSM protect plants against herbivores and pathogens, act as pesticides, insecticides, and anthelmintics, while also attracting pollinators and seed dispersers. Therefore, it is important t...

Discovery of secondary metabolites from Bacillus spp. biocontrol strains using genome mining and mass spectroscopy

USDA-ARS?s Scientific Manuscript database

Genome sequencing, data mining and mass spectrometry were used to identify secondary metabolites produced by several Bacillus spp. biocontrol strains. These biocontrol strains have shown promise in managing Fusarium head blight in wheat. Draft genomes were produced and screened in silico using genom...

Phenolic composition of basil plants is differentially altered by plant nutrient status and inoculation with mycorrhizal fungi

USDA-ARS?s Scientific Manuscript database

Quality of basil plants (Ocimum basilicum) used in certain fresh and dry products is a function of its production of secondary metabolites, including phenolic compounds. Nutrient availability, particularly phosphorus (P), can alter plant production of secondary metabolites, and root infection by arb...

Importance of accurate measurements in nutrition research: dietary flavonoids as a case study

USDA-ARS?s Scientific Manuscript database

Accurate measurements of the secondary metabolites in natural products and plant foods are critical to establishing diet/health relationships. There are as many as 50,000 secondary metabolites which may influence human health. Their structural and chemical diversity present a challenge to analytic...

Hops (Humulus lupulus) ß-acid as an inhibitor of caprine rumen hyper-ammonia-producing bacteria in vitro

USDA-ARS?s Scientific Manuscript database

Antimicrobial plant secondary metabolites increase rumen efficiency and decrease waste products (i.e. ammonia, methane) in some cases. A promising source of bioactive secondary metabolites is the hops plant (Humulus lupulus L.), which produces '-acid, a suite of structurally similar, potent antibact...

The use of genomics and chemistry to screen for secondary metabolites in bacillus spp. biocontrol organisms

USDA-ARS?s Scientific Manuscript database

Recent advances in DNA sequencing technologies have revolutionized the way we study bacterial biological control strains. These advances have provided the ability to rapidily characterize the secondary metabolite potential of these bacterial strains. A variety of bioinformatics tools have been devel...

Transcriptome analysis of Petunia axillaris flowers reveals genes involved in morphological differentiation and metabolite transport

PubMed Central

Amano, Ikuko; Kitajima, Sakihito; Suzuki, Hideyuki; Koeduka, Takao

2018-01-01

The biosynthesis of plant secondary metabolites is associated with morphological and metabolic differentiation. As a consequence, gene expression profiles can change drastically, and primary and secondary metabolites, including intermediate and end-products, move dynamically within and between cells. However, little is known about the molecular mechanisms underlying differentiation and transport mechanisms. In this study, we performed a transcriptome analysis of Petunia axillaris subsp. parodii, which produces various volatiles in its corolla limbs and emits metabolites to attract pollinators. RNA-sequencing from leaves, buds, and limbs identified 53,243 unigenes. Analysis of differentially expressed genes, combined with gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses, showed that many biological processes were highly enriched in limbs. These included catabolic processes and signaling pathways of hormones, such as gibberellins, and metabolic pathways, including phenylpropanoids and fatty acids. Moreover, we identified five transporter genes that showed high expression in limbs, and we performed spatiotemporal expression analyses and homology searches to infer their putative functions. Our systematic analysis provides comprehensive transcriptomic information regarding morphological differentiation and metabolite transport in the Petunia flower and lays the foundation for establishing the specific mechanisms that control secondary metabolite biosynthesis in plants. PMID:29902274

Does Osmotic Stress Affect Natural Product Expression in Fungi?

PubMed

Overy, David; Correa, Hebelin; Roullier, Catherine; Chi, Wei-Chiung; Pang, Ka-Lai; Rateb, Mostafa; Ebel, Rainer; Shang, Zhuo; Capon, Rob; Bills, Gerald; Kerr, Russell

2017-08-13

The discovery of new natural products from fungi isolated from the marine environment has increased dramatically over the last few decades, leading to the identification of over 1000 new metabolites. However, most of the reported marine-derived species appear to be terrestrial in origin yet at the same time, facultatively halo- or osmotolerant. An unanswered question regarding the apparent chemical productivity of marine-derived fungi is whether the common practice of fermenting strains in seawater contributes to enhanced secondary metabolism? To answer this question, a terrestrial isolate of Aspergillus aculeatus was fermented in osmotic and saline stress conditions in parallel across multiple sites. The ex-type strain of A. aculeatus was obtained from three different culture collections. Site-to-site variations in metabolite expression were observed, suggesting that subculturing of the same strain and subtle variations in experimental protocols can have pronounced effects upon metabolite expression. Replicated experiments at individual sites indicated that secondary metabolite production was divergent between osmotic and saline treatments. Titers of some metabolites increased or decreased in response to increasing osmolite (salt or glycerol) concentrations. Furthermore, in some cases, the expression of some secondary metabolites in relation to osmotic and saline stress was attributed to specific sources of the ex-type strains.

Solid-Phase Enrichment and Analysis of Azide-Labeled Natural Products: Fishing Downstream of Biochemical Pathways.

PubMed

Pérez, Alexander J; Wesche, Frank; Adihou, Hélène; Bode, Helge B

2016-01-11

Many methods have been devised over the decades to trace precursors of specific molecules in cellular environments as, for example, in biosynthesis studies. The advent of click chemistry has facilitated the powerful combination of tracing and at the same time sieving the highly complex metabolome for compounds derived from simple or complex starting materials, especially when the click reaction takes place on a solid support. While the principle of solid-phase click reactions has already been successfully applied for selective protein and peptide enrichment, the successful enrichment of much smaller primary and secondary metabolites, showing great structural diversity and undergoing many different biosynthetic steps, has seen only little development. For bacterial secondary metabolism, a far broader tolerance for "clickable" precursors was observed than in ribosomal proteinogenesis, thus making this method a surprisingly valuable tool for the tracking and discovery of compounds within the cellular biochemical network. The implementation of this method has led to the identification of several new compounds from the bacterial genera Photorhabdus and Xenorhabdus, clearly proving its power. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Multiplexed, quantitative, and targeted metabolite profiling by LC-MS/MRM.

PubMed

Wei, Ru; Li, Guodong; Seymour, Albert B

2014-01-01

Targeted metabolomics, which focuses on a subset of known metabolites representative of biologically relevant metabolic pathways, is a valuable tool to discover biomarkers and link disease phenotypes to underlying mechanisms or therapeutic modes of action. A key advantage of targeted metabolomics, compared to discovery metabolomics, is its immediate readiness for extracting biological information derived from known metabolites and quantitative measurements. However, simultaneously analyzing hundreds of endogenous metabolites presents a challenge due to their diverse chemical structures and properties. Here we report a method which combines different chromatographic separation conditions, optimal ionization polarities, and the most sensitive triple-quadrupole MS-based data acquisition mode, multiple reaction monitoring (MRM), to quantitatively profile 205 endogenous metabolites in 10 min.

Metabolome-genome-wide association study dissects genetic architecture for generating natural variation in rice secondary metabolism

PubMed Central

Matsuda, Fumio; Nakabayashi, Ryo; Yang, Zhigang; Okazaki, Yozo; Yonemaru, Jun-ichi; Ebana, Kaworu; Yano, Masahiro; Saito, Kazuki

2015-01-01

Plants produce structurally diverse secondary (specialized) metabolites to increase their fitness for survival under adverse environments. Several bioactive compounds for new drugs have been identified through screening of plant extracts. In this study, genome-wide association studies (GWAS) were conducted to investigate the genetic architecture behind the natural variation of rice secondary metabolites. GWAS using the metabolome data of 175 rice accessions successfully identified 323 associations among 143 single nucleotide polymorphisms (SNPs) and 89 metabolites. The data analysis highlighted that levels of many metabolites are tightly associated with a small number of strong quantitative trait loci (QTLs). The tight association may be a mechanism generating strains with distinct metabolic composition through the crossing of two different strains. The results indicate that one plant species produces more diverse phytochemicals than previously expected, and plants still contain many useful compounds for human applications. PMID:25267402

Secondary Metabolite Accumulation Associates with Ecological Succession of Endophytic Fungi in Cynomorium songaricum Rupr.

PubMed

Cui, Jin-Long; Zhang, Yan-Yan; Vijayakumar, Vinod; Zhang, Gang; Wang, Meng-Liang; Wang, Jun-Hong

2018-06-06

Cynomorium songaricum Rupr. is a rare root-parasitic plant distributed in the desert ecosystem. Little is known about the role of endophytes in accumulation of metabolites in C. songaricum. Here, the correlations between the seven active components (total sugars, flavonoids, protocatechuic acid, catechins, tannins, gallic acid, and ursolic acid) and the endophytic fungi of C. songaricum were investigated, and their causal relationships are discussed further. The results showed that the accumulation of these components and the assembly of endophytic fungi changed with different plant developmental stages. Diverse relationships including positive and negative correlation were found among chemicals and endophytic fungal operational taxonomic units based on correlation coefficient matrices, which demonstrated that the accumulation of secondary metabolites in C. songaricum is closely related to the endophytic fungal community composition. These results present new opportunities to deeply understand plant-fungal symbioses and secondary metabolite productions.

Deep Sea Actinomycetes and Their Secondary Metabolites

PubMed Central

Kamjam, Manita; Sivalingam, Periyasamy; Deng, Zinxin; Hong, Kui

2017-01-01

Deep sea is a unique and extreme environment. It is a hot spot for hunting marine actinomycetes resources and secondary metabolites. The novel deep sea actinomycete species reported from 2006 to 2016 including 21 species under 13 genera with the maximum number from Microbacterium, followed by Dermacoccus, Streptomyces and Verrucosispora, and one novel species for the other 9 genera. Eight genera of actinomycetes were reported to produce secondary metabolites, among which Streptomyces is the richest producer. Most of the compounds produced by the deep sea actinomycetes presented antimicrobial and anti-cancer cell activities. Gene clusters related to biosynthesis of desotamide, heronamide, and lobophorin have been identified from the deep sea derived Streptomyces. PMID:28507537

System-Level and Granger Network Analysis of Integrated Proteomic and Metabolomic Dynamics Identifies Key Points of Grape Berry Development at the Interface of Primary and Secondary Metabolism.

PubMed

Wang, Lei; Sun, Xiaoliang; Weiszmann, Jakob; Weckwerth, Wolfram

2017-01-01

Grapevine is a fruit crop with worldwide economic importance. The grape berry undergoes complex biochemical changes from fruit set until ripening. This ripening process and production processes define the wine quality. Thus, a thorough understanding of berry ripening is crucial for the prediction of wine quality. For a systemic analysis of grape berry development we applied mass spectrometry based platforms to analyse the metabolome and proteome of Early Campbell at 12 stages covering major developmental phases. Primary metabolites involved in central carbon metabolism, such as sugars, organic acids and amino acids together with various bioactive secondary metabolites like flavonols, flavan-3-ols and anthocyanins were annotated and quantified. At the same time, the proteomic analysis revealed the protein dynamics of the developing grape berries. Multivariate statistical analysis of the integrated metabolomic and proteomic dataset revealed the growth trajectory and corresponding metabolites and proteins contributing most to the specific developmental process. K-means clustering analysis revealed 12 highly specific clusters of co-regulated metabolites and proteins. Granger causality network analysis allowed for the identification of time-shift correlations between metabolite-metabolite, protein- protein and protein-metabolite pairs which is especially interesting for the understanding of developmental processes. The integration of metabolite and protein dynamics with their corresponding biochemical pathways revealed an energy-linked metabolism before veraison with high abundances of amino acids and accumulation of organic acids, followed by protein and secondary metabolite synthesis. Anthocyanins were strongly accumulated after veraison whereas other flavonoids were in higher abundance at early developmental stages and decreased during the grape berry developmental processes. A comparison of the anthocyanin profile of Early Campbell to other cultivars revealed similarities to Concord grape and indicates the strong effect of genetic background on metabolic partitioning in primary and secondary metabolism.

System-Level and Granger Network Analysis of Integrated Proteomic and Metabolomic Dynamics Identifies Key Points of Grape Berry Development at the Interface of Primary and Secondary Metabolism

PubMed Central

Wang, Lei; Sun, Xiaoliang; Weiszmann, Jakob; Weckwerth, Wolfram

2017-01-01

Grapevine is a fruit crop with worldwide economic importance. The grape berry undergoes complex biochemical changes from fruit set until ripening. This ripening process and production processes define the wine quality. Thus, a thorough understanding of berry ripening is crucial for the prediction of wine quality. For a systemic analysis of grape berry development we applied mass spectrometry based platforms to analyse the metabolome and proteome of Early Campbell at 12 stages covering major developmental phases. Primary metabolites involved in central carbon metabolism, such as sugars, organic acids and amino acids together with various bioactive secondary metabolites like flavonols, flavan-3-ols and anthocyanins were annotated and quantified. At the same time, the proteomic analysis revealed the protein dynamics of the developing grape berries. Multivariate statistical analysis of the integrated metabolomic and proteomic dataset revealed the growth trajectory and corresponding metabolites and proteins contributing most to the specific developmental process. K-means clustering analysis revealed 12 highly specific clusters of co-regulated metabolites and proteins. Granger causality network analysis allowed for the identification of time-shift correlations between metabolite-metabolite, protein- protein and protein-metabolite pairs which is especially interesting for the understanding of developmental processes. The integration of metabolite and protein dynamics with their corresponding biochemical pathways revealed an energy-linked metabolism before veraison with high abundances of amino acids and accumulation of organic acids, followed by protein and secondary metabolite synthesis. Anthocyanins were strongly accumulated after veraison whereas other flavonoids were in higher abundance at early developmental stages and decreased during the grape berry developmental processes. A comparison of the anthocyanin profile of Early Campbell to other cultivars revealed similarities to Concord grape and indicates the strong effect of genetic background on metabolic partitioning in primary and secondary metabolism. PMID:28713396

Dung-inhabiting fungi: a potential reservoir of novel secondary metabolites for the control of plant pathogens.

PubMed

Sarrocco, Sabrina

2016-04-01

Coprophilous fungi are a large group of saprotrophic fungi mostly found in herbivore dung. The number of these fungi undergoing investigation is continually increasing, and new species and genera continue to be described. Dung-inhabiting fungi play an important ecological role in decomposing and recycling nutrients from animal dung. They produce a large array of bioactive secondary metabolites and have a potent enzymatic arsenal able to utilise even complex molecules. Bioactive secondary metabolites are actively involved in interaction with and defence against other organisms whose growth can be inhibited, resulting in an enhanced ecological fitness of producer strains. Currently, these antibiotics and bioactive secondary metabolites are of interest in medicine in particular, while very little information is available concerning their potential use in agriculture. This review introduces the ecology of dung-inhabiting fungi, with particular emphasis on the production of antibiotic compounds as a means to compete with other microorganisms. Owing to the fast pace of technological progress, new approaches to predicting the biosynthesis of bioactive metabolites are proposed. Coprophilous fungi should be considered as elite candidate organisms for the discovery of novel antifungal compounds, above all in view of their exploitation for crop protection. © 2015 Society of Chemical Industry.

Heterochromatin influences the secondary metabolite profile in the plant pathogen Fusarium graminearum

PubMed Central

Reyes-Dominguez, Yazmid; Boedi, Stefan; Sulyok, Michael; Wiesenberger, Gerlinde; Stoppacher, Norbert; Krska, Rudolf; Strauss, Joseph

2012-01-01

Chromatin modifications and heterochromatic marks have been shown to be involved in the regulation of secondary metabolism gene clusters in the fungal model system Aspergillus nidulans. We examine here the role of HEP1, the heterochromatin protein homolog of Fusarium graminearum, for the production of secondary metabolites. Deletion of Hep1 in a PH-1 background strongly influences expression of genes required for the production of aurofusarin and the main tricothecene metabolite DON. In the Hep1 deletion strains AUR genes are highly up-regulated and aurofusarin production is greatly enhanced suggesting a repressive role for heterochromatin on gene expression of this cluster. Unexpectedly, gene expression and metabolites are lower for the trichothecene cluster suggesting a positive function of Hep1 for DON biosynthesis. However, analysis of histone modifications in chromatin of AUR and DON gene promoters reveals that in both gene clusters the H3K9me3 heterochromatic mark is strongly reduced in the Hep1 deletion strain. This, and the finding that a DON-cluster flanking gene is up-regulated, suggests that the DON biosynthetic cluster is repressed by HEP1 directly and indirectly. Results from this study point to a conserved mode of secondary metabolite (SM) biosynthesis regulation in fungi by chromatin modifications and the formation of facultative heterochromatin. PMID:22100541

Multi-Omics of Tomato Glandular Trichomes Reveals Distinct Features of Central Carbon Metabolism Supporting High Productivity of Specialized Metabolites[OPEN

PubMed Central

Bennewitz, Stefan; Bergau, Nick; Athmer, Benedikt; Henning, Anja; Majovsky, Petra; Jiménez-Gómez, José M.

2017-01-01

Glandular trichomes are metabolic cell factories with the capacity to produce large quantities of secondary metabolites. Little is known about the connection between central carbon metabolism and metabolic productivity for secondary metabolites in glandular trichomes. To address this gap in our knowledge, we performed comparative metabolomics, transcriptomics, proteomics, and 13C-labeling of type VI glandular trichomes and leaves from a cultivated (Solanum lycopersicum LA4024) and a wild (Solanum habrochaites LA1777) tomato accession. Specific features of glandular trichomes that drive the formation of secondary metabolites could be identified. Tomato type VI trichomes are photosynthetic but acquire their carbon essentially from leaf sucrose. The energy and reducing power from photosynthesis are used to support the biosynthesis of secondary metabolites, while the comparatively reduced Calvin-Benson-Bassham cycle activity may be involved in recycling metabolic CO2. Glandular trichomes cope with oxidative stress by producing high levels of polyunsaturated fatty acids, oxylipins, and glutathione. Finally, distinct mechanisms are present in glandular trichomes to increase the supply of precursors for the isoprenoid pathways. Particularly, the citrate-malate shuttle supplies cytosolic acetyl-CoA and plastidic glycolysis and malic enzyme support the formation of plastidic pyruvate. A model is proposed on how glandular trichomes achieve high metabolic productivity. PMID:28408661

Transgenic mimicry of pathogen attack stimulates growth and secondary metabolite accumulation.

PubMed

Chaudhuri, Kuntal; Das, Sudripta; Bandyopadhyay, Moumita; Zalar, Andreja; Kollmann, Albert; Jha, Sumita; Tepfer, David

2009-02-01

Plant secondary metabolites, including pharmaceuticals, flavorings and aromas, are often produced in response to stress. We used chemical inducers of the pathogen defense response (jasmonic acid, salicylate, killed fungi, oligosaccharides and the fungal elicitor protein, cryptogein) to increase metabolite and biomass production in transformed root cultures of the medicinal plant, Withania somnifera, and the weed, Convolvulus sepium. In an effort to genetically mimic the observed effects of cryptogein, we employed Agrobacterium rhizogenes to insert a synthetic gene encoding cryptogein into the roots of C. sepium, W. somnifera and Tylophora tanakae. This genetic transformation was associated with stimulation in both secondary metabolite production and growth in the first two species, and in growth in the third. In whole plants of Convolvulus arvensis and Arabidopsis thaliana, transformation with the cryptogein gene led, respectively, to increases in the calystegines and certain flavonoids. A similar transgenic mimicry of pathogen attack was previously employed to stimulate resistance to the pathogen and abiotic stress. In the present study of biochemical phenotype, we show that transgenic mimicry is correlated with increased secondary metabolite production in transformed root cultures and whole plants. We propose that natural transformation with genes encoding the production of microbial elicitors could influence interactions between plants and other organisms.

Cultivation of Marine Sponges.

PubMed

Osinga; Tramper; Wijffels

1999-11-01

There is increasing interest in biotechnological production of marine sponge biomass owing to the discovery of many commercially important secondary metabolites in this group of animals. In this article, different approaches to producing sponge biomass are reviewed, and several factors that possibly influence culture success are evaluated. In situ sponge aquacultures, based on old methods for producing commercial bath sponges, are still the easiest and least expensive way to obtain sponge biomass in bulk. However, success of cultivation with this method strongly depends on the unpredictable and often suboptimal natural environment. Hence, a better-defined production system would be desirable. Some progress has been made with culturing sponges in semicontrolled systems, but these still use unfiltered natural seawater. Cultivation of sponges under completely controlled conditions has remained a problem. When designing an in vitro cultivation method, it is important to determine both qualitatively and quantitatively the nutritional demands of the species that is to be cultured. An adequate supply of food seems to be the key to successful sponge culture. Recently, some progress has been made with sponge cell cultures. The advantage of cell cultures is that they are completely controlled and can easily be manipulated for optimal production of the target metabolites. However, this technique is still in its infancy: a continuous cell line has yet to be established. Axenic cultures of sponge aggregates (primmorphs) may provide an alternative to cell culture. Some sponge metabolites are, in fact, produced by endosymbiotic bacteria or algae that live in the sponge tissue. Only a few of these endosymbionts have been cultivated so far. The biotechnology for the production of sponge metabolites needs further development. Research efforts should be continued to enable commercial exploitation of this valuable natural resource in the near future.

Insights into the mechanisms of Promysalin, a secondary metabolite with genus-specific antibacterial activity against Pseudomonas

USDA-ARS?s Scientific Manuscript database

Promysalin, a secondary metabolite produced by Pseudomonas putida RW10S1, has antibacterial activity against a wide variety of Pseudomonas sp., including both human and plant pathogens. Promysalin induces swarming and biofilm formation in the producing species, and inhibits growth of susceptible sp...

Plant protein and secondary metabolites influence diet selection in a mammalian specialist herbivore

Treesearch

Amy C. Ulappa; Rick G. Kelsey; Graham G. Frye; Janet L. Rachlow; LIsa A. Shipley; Laura Bond; Xinzhu Pu; Jennifer Sorensen Forbey

2014-01-01

For herbivores, nutrient intake is limited by the relatively low nutritional quality of plants and high concentrations of potentially toxic defensive compounds (plant secondary metabolites [PSMs]) produced by many plants. In response to phytochemical challenges, some herbivores selectively forage on plants with higher nutrient and lower PSM concentrations relative to...

Secondary metabolites from the unique bamboo, Melocanna baccifera.

PubMed

Govindan, Balaji; Johnson, Anil John; Viswanathan, Gayathri; Ramaswamy, Venkataraman; Koshy, Konnath Chacko; Baby, Sabulal

2018-02-15

Phytochemistry of fruits and leaves of the unique bamboo Melocanna baccifera resulted in the isolation of 27 secondary metabolites, including 4-Oxabicyclo[3.2.2]nona-1(7),5,8-triene and Verbacine. Biological activity studies of Verbacine revealed it as an inhibitor of acetylcholinesterase and as cytotoxic against C6 cancer cells.

[Microbial secondary metabolites as potential reserve of pharmaceuticals].

PubMed

Orlova, T I; Bulgakova, V G; Polin, A N

2014-01-01

The major characteristics of new bioactive microbial secondary metabolites are summarized in the review. A wide range of new molecular targets are implicated in discovery of new nonantibiotic compounds with some other pharmacological activities (noninfectious diseases). Microorganisms represent fascinating resources due to their production of novel products with broad spectra of bioactivities.

Secondary metabolite profiles of leaves of healthy and huanglongbing-infected orange (Citrus sinensis L.) seedlings measured by HPLC-fluorescence detection

USDA-ARS?s Scientific Manuscript database

Leaves of greenhouse-grown ‘Hamlin’ and ‘Valencia’ orange (Citrus sinensis L.) seedlings were analyzed by high performance liquid chromatography in a study of the progression of changes in secondary metabolite profiles resulting from infection by Candidatus Liberibacter asiaticus (CLas), the Huanglo...

Analysis of the Aspergillus flavus transcriptome reveals a key role of secondary metabolite production in isolate oxidative stress responses

USDA-ARS?s Scientific Manuscript database

The purpose of the production of secondary metabolites in fungi are various and include stress responses, competitive antimicrobial activity, and the elimination of toxic compounds. However, the purpose of the production of aflatoxin, a carcinogenic mycotoxin, by Aspergillus flavus, is unknown. Prev...

Transcriptome of Aspergillus flavus aswA (AFLA_085170) deletion strain related to sclerotial development and production of secondary metabolites

USDA-ARS?s Scientific Manuscript database

Aspergillus flavus produces many secondary metabolites including aflatoxins. Besides conidia, the fungus uses sclerotia as another type of propagule. We obtained transcriptomes from four growth conditions of the aswA mutant, a strain impaired in sclerotial development and production of sclerotium-sp...

Genomic analysis of Ascochyta rabiei identifies dynamic genome environments of solanapyrone biosynthesis gene cluster and a novel type of pathway-specific regulator

USDA-ARS?s Scientific Manuscript database

Secondary metabolite genes are often clustered together and situated in particular genomic regions such as the subtelomere, which can facilitate niche adaptation in fungi. Solanapyrones are toxic secondary metabolites produced by fungi occupying different ecological niches. Full genome sequencing of...

Spearmint R2R3-MYB transcription factor MsMYB negatively regulates monoterpene production and suppresses the expression of geranyl diphosphate synthase large subunit (MsGPPS.LSU).

PubMed

Reddy, Vaishnavi Amarr; Wang, Qian; Dhar, Niha; Kumar, Nadimuthu; Venkatesh, Prasanna Nori; Rajan, Chakravarthy; Panicker, Deepa; Sridhar, Vishweshwaran; Mao, Hui-Zhu; Sarojam, Rajani

2017-09-01

Many aromatic plants, such as spearmint, produce valuable essential oils in specialized structures called peltate glandular trichomes (PGTs). Understanding the regulatory mechanisms behind the production of these important secondary metabolites will help design new approaches to engineer them. Here, we identified a PGT-specific R2R3-MYB gene, MsMYB, from comparative RNA-Seq data of spearmint and functionally characterized it. Analysis of MsMYB-RNAi transgenic lines showed increased levels of monoterpenes, and MsMYB-overexpressing lines exhibited decreased levels of monoterpenes. These results suggest that MsMYB is a novel negative regulator of monoterpene biosynthesis. Ectopic expression of MsMYB, in sweet basil and tobacco, perturbed sesquiterpene- and diterpene-derived metabolite production. In addition, we found that MsMYB binds to cis-elements of MsGPPS.LSU and suppresses its expression. Phylogenetic analysis placed MsMYB in subgroup 7 of R2R3-MYBs whose members govern phenylpropanoid pathway and are regulated by miR858. Analysis of transgenic lines showed that MsMYB is more specific to terpene biosynthesis as it did not affect metabolites derived from phenylpropanoid pathway. Further, our results indicate that MsMYB is probably not regulated by miR858, like other members of subgroup 7. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

Genetic and Metabolite Diversity of Sardinian Populations of Helichrysum italicum

PubMed Central

Melito, Sara; Sias, Angela; Petretto, Giacomo L.; Chessa, Mario; Pintore, Giorgio; Porceddu, Andrea

2013-01-01

Background Helichrysum italicum (Asteraceae) is a small shrub endemic to the Mediterranean Basin, growing in fragmented and diverse habitats. The species has attracted attention due to its secondary metabolite content, but little effort has as yet been dedicated to assessing the genetic and metabolite diversity present in these populations. Here, we describe the diversity of 50 H. italicum populations collected from a range of habitats in Sardinia. Methods H. italicum plants were AFLP fingerprinted and the composition of their leaf essential oil characterized by GC-MS. The relationships between the genetic structure of the populations, soil, habitat and climatic variables and the essential oil chemotypes present were evaluated using Bayesian clustering, contingency analyses and AMOVA. Key results The Sardinian germplasm could be partitioned into two AFLP-based clades. Populations collected from the southwestern region constituted a homogeneous group which remained virtually intact even at high levels of K. The second, much larger clade was more diverse. A positive correlation between genetic diversity and elevation suggested the action of natural purifying selection. Four main classes of compounds were identified among the essential oils, namely monoterpenes, oxygenated monoterpenes, sesquiterpenes and oxygenated sesquiterpenes. Oxygenated monoterpene levels were significantly correlated with the AFLP-based clade structure, suggesting a correspondence between gene pool and chemical diversity. Conclusions The results suggest an association between chemotype, genetic diversity and collection location which is relevant for the planning of future collections aimed at identifying valuable sources of essential oil. PMID:24260149

Bioactive Metabolites from Pathogenic and Endophytic Fungi of Forest Trees.

PubMed

Masi, Marco; Maddau, Lucia; Linaldeddu, Benedetto Teodoro; Scanu, Bruno; Evidente, Antonio; Cimmino, Alessio

2018-01-01

Fungi play an important role in terrestrial ecosystems interacting positively or negatively with plants. These interactions are complex and the outcomes are different depending on the fungal lifestyles, saprotrophic, mutualistic or pathogenic. Furthermore, fungi are well known for producing secondary metabolites, originating from different biosynthetic pathways, which possess biological properties of considerable biotechnological interest. Among the terrestrial ecosystems, temperate forests represent an enormous reservoir of fungal diversity. This review will highlight the goldmine of secondary metabolites produced by pathogenic and endophytic fungi of forest trees with focus on their biological activities. A structured search of bibliographic databases for peer-reviewed research literature was undertaken using a research discovery application providing access to a large and authoritative source of references. The papers selected were examined and the main results were reported and discussed. Two hundred forthy-one papers were included in the review, outlined a large number of secondary metabolites produced by pathogenic and endophiltic fungi and their biological activities, including phytotoxic, antifungal, antioomycetes, antibacterial, brine shrimp lethality, mosquito biting deterrence and larvicidal, cytotoxic, antiproliferative and many other bioactivities. The findings of this review confirm the importance of secondary metabolites produced by pathogenic and endophytic fungi from forest plants growing in temperate regions as an excellent prospects to discover compounds with new bioactivities and mode of actions. In addition, the potential of some metabolites as a source of new drugs and biopesticides is underlined. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Use of Direct-Infusion Electrospray Mass Spectrometry To Guide Empirical Development of Improved Conditions for Expression of Secondary Metabolites from Actinomycetes

PubMed Central

Zahn, James A.; Higgs, Richard E.; Hilton, Matthew D.

2001-01-01

A major barrier in the discovery of new secondary metabolites from microorganisms is the difficulty of distinguishing the minor fraction of productive cultures from the majority of unproductive cultures and growth conditions. In this study, a rapid, direct-infusion electrospray mass spectrometry (ES-MS) technique was used to identify chemical differences that occurred in the expression of secondary metabolites by 44 actinomycetes cultivated under six different fermentation conditions. Samples from actinomycete fermentations were prepared by solid-phase extraction, analyzed by ES-MS, and ranked according to a chemical productivity index based on the total number and relative intensity of ions present in each sample. The actinomycete cultures were tested for chemical productivity following treatments that included nutritional manipulations, autoregulator additions, and different agitation speeds and incubation temperatures. Evaluation of the ES-MS data from submerged and solid-state fermentations by paired t test analyses showed that solid-state growth significantly altered the chemical profiles of extracts from 75% of the actinomycetes evaluated. Parallel analysis of the same extracts by high-performance liquid chromatography–ES-MS–evaporative light scattering showed that the chemical differences detected by the ES-MS method were associated with growth condition-dependent changes in the yield of secondary metabolites. Our results indicate that the high-throughput ES-MS method is useful for identification of fermentation conditions that enhance expression of secondary metabolites from actinomycetes. PMID:11133469

Unraveling the efficient applications of secondary metabolites of various Trichoderma spp.

PubMed

Keswani, Chetan; Mishra, Sandhya; Sarma, Birinchi Kumar; Singh, Surya Pratap; Singh, Harikesh Bahadur

2014-01-01

Recent shift in trends of agricultural practices from application of synthetic fertilizers and pesticides to organic farming has brought into focus the use of microorganisms that carryout analogous function. Trichoderma spp. is one of the most popular genera of fungi commercially available as a plant growth promoting fungus (PGPF) and biological control agent. Exploitation of the diverse nature of secondary metabolites produced by different species of Trichoderma augments their extensive utility in agriculture and related industries. As a result, Trichoderma has achieved significant success as a powerful biocontrol agent at global level. The endorsement of Trichoderma spp. by scientific community is based on the understanding of its mechanisms of action against a large set of fungal, bacterial and in certain cases viral infections. However, it is still an agnostic view that there could be any single major mode of operation, although it is argued that all mechanisms operate simultaneously in a synchronized fashion. The central idea behind this review article is to emphasize the potentiality of applications of target specific secondary metabolites of Trichoderma for controlling phytopathogens as a substitute of commercially available whole organism formulations. With the aim to this point, we have compiled an inclusive list of secondary metabolites produced by different species of Trichoderma and their applications in diverse areas with the major emphasis on agriculture. Outlining the importance and diverse activities of secondary metabolites of Trichoderma besides its relevance to agriculture would generate greater understanding of their other important and beneficial applications apart from target specific biopesticides.

Transcriptome Analysis of Aspergillus flavus Reveals veA-Dependent Regulation of Secondary Metabolite Gene Clusters, Including the Novel Aflavarin Cluster

PubMed Central

Cary, J. W.; Han, Z.; Yin, Y.; Lohmar, J. M.; Shantappa, S.; Harris-Coward, P. Y.; Mack, B.; Ehrlich, K. C.; Wei, Q.; Arroyo-Manzanares, N.; Uka, V.; Vanhaecke, L.; Bhatnagar, D.; Yu, J.; Nierman, W. C.; Johns, M. A.; Sorensen, D.; Shen, H.; De Saeger, S.; Diana Di Mavungu, J.

2015-01-01

The global regulatory veA gene governs development and secondary metabolism in numerous fungal species, including Aspergillus flavus. This is especially relevant since A. flavus infects crops of agricultural importance worldwide, contaminating them with potent mycotoxins. The most well-known are aflatoxins, which are cytotoxic and carcinogenic polyketide compounds. The production of aflatoxins and the expression of genes implicated in the production of these mycotoxins are veA dependent. The genes responsible for the synthesis of aflatoxins are clustered, a signature common for genes involved in fungal secondary metabolism. Studies of the A. flavus genome revealed many gene clusters possibly connected to the synthesis of secondary metabolites. Many of these metabolites are still unknown, or the association between a known metabolite and a particular gene cluster has not yet been established. In the present transcriptome study, we show that veA is necessary for the expression of a large number of genes. Twenty-eight out of the predicted 56 secondary metabolite gene clusters include at least one gene that is differentially expressed depending on presence or absence of veA. One of the clusters under the influence of veA is cluster 39. The absence of veA results in a downregulation of the five genes found within this cluster. Interestingly, our results indicate that the cluster is expressed mainly in sclerotia. Chemical analysis of sclerotial extracts revealed that cluster 39 is responsible for the production of aflavarin. PMID:26209694

Use of direct-infusion electrospray mass spectrometry to guide empirical development of improved conditions for expression of secondary metabolites from actinomycetes.

PubMed

Zahn, J A; Higgs, R E; Hilton, M D

2001-01-01

A major barrier in the discovery of new secondary metabolites from microorganisms is the difficulty of distinguishing the minor fraction of productive cultures from the majority of unproductive cultures and growth conditions. In this study, a rapid, direct-infusion electrospray mass spectrometry (ES-MS) technique was used to identify chemical differences that occurred in the expression of secondary metabolites by 44 actinomycetes cultivated under six different fermentation conditions. Samples from actinomycete fermentations were prepared by solid-phase extraction, analyzed by ES-MS, and ranked according to a chemical productivity index based on the total number and relative intensity of ions present in each sample. The actinomycete cultures were tested for chemical productivity following treatments that included nutritional manipulations, autoregulator additions, and different agitation speeds and incubation temperatures. Evaluation of the ES-MS data from submerged and solid-state fermentations by paired t test analyses showed that solid-state growth significantly altered the chemical profiles of extracts from 75% of the actinomycetes evaluated. Parallel analysis of the same extracts by high-performance liquid chromatography-ES-MS-evaporative light scattering showed that the chemical differences detected by the ES-MS method were associated with growth condition-dependent changes in the yield of secondary metabolites. Our results indicate that the high-throughput ES-MS method is useful for identification of fermentation conditions that enhance expression of secondary metabolites from actinomycetes.

The past, present and future of secondary metabolite research in the Dothideomycetes.

PubMed

Muria-Gonzalez, Mariano Jordi; Chooi, Yit-Heng; Breen, Susan; Solomon, Peter S

2015-01-01

The Dothideomycetes represents a large and diverse array of fungi in which prominent plant pathogens are over-represented. Species within the Cochliobolus, Alternaria, Pyrenophora and Mycosphaerella (amongst others) all cause diseases that threaten food security in many parts of the world. Significant progress has been made over the past decade in understanding how some of these pathogens cause disease at a molecular level. It is reasonable to suggest that much of this progress can be attributed to the increased availability of genome sequences. However, together with revealing mechanisms of pathogenicity, these genome sequences have also highlighted the capacity of the Dothideomycetes to produce an extensive array of secondary metabolites, far greater than originally thought. Indeed, it is now clear that we appear to have only scratched the surface to date in terms of the identification of secondary metabolites produced by these fungi. In the first half of this review, we examine the current status of secondary metabolite research in the Dothideomycetes and highlight the diversity of the molecules discovered thus far, in terms of both structure and biological activity. In the second part of this review, we survey the emerging techniques and technologies that will be required to shed light on the vast array of secondary metabolite potential that is encoded within these genomes. Experimental design, analytical chemistry and synthetic biology are all discussed in the context of how they will contribute to this field. © 2014 BSPP AND JOHN WILEY & SONS LTD.

Saponins from sea cucumber and their biological activities.

PubMed

Zhao, Yingcai; Xue, Changhu; Zhang, Tiantian; Wang, YuMing

2018-06-22

Sea cucumbers, belonging to the phylum Echinodermata, have been valued for centuries as a nutritious and functional food with various bioactivities. Sea cucumbers can produce highly active substances, notably saponins, the main secondary metabolites, which are the basis of their chemical defense. The saponins are mostly triterpene glycosides with triterpenes or steroid in aglycone, which possess multiple biological properties including anti-tumor, hypolipidemic activity, improvement of nonalcoholic fatty liver, inhibition of fat accumulation, anti-hyperuricemia, promotion of bone marrow hematopoiesis, anti-hypertension, etc. Sea cucumber saponins have received attention due to their rich sources, low toxicity, high efficiency, and few side effects. This review summarizes current research on the structure and activities of sea cucumber saponins based on the physiological and pharmacological activities from source, experimental models, efficacy and mechanisms, which may provide a valuable reference for the development of sea cucumber saponins.

Comparative Chemistry of Aspergillus oryzae (RIB40) and A. flavus (NRRL 3357)

PubMed Central

Rank, Christian; Klejnstrup, Marie Louise; Petersen, Lene Maj; Kildgaard, Sara; Frisvad, Jens Christian; Gotfredsen, Charlotte Held; Larsen, Thomas Ostenfeld

2012-01-01

Aspergillus oryzae and A. flavus are important species in industrial biotechnology and food safety and have been some of the first aspergilli to be fully genome sequenced. Bioinformatic analysis has revealed 99.5% gene homology between the two species pointing towards a large coherence in the secondary metabolite production. In this study we report on the first comparison of secondary metabolite production between the full genome sequenced strains of A. oryzae (RIB40) and A. flavus (NRRL 3357). Surprisingly, the overall chemical profiles of the two strains were mostly very different across 15 growth conditions. Contrary to previous studies we found the aflatrem precursor 13-desoxypaxilline to be a major metabolite from A. oryzae under certain growth conditions. For the first time, we additionally report A. oryzae to produce parasiticolide A and two new analogues hereof, along with four new alkaloids related to the A. flavus metabolites ditryptophenalines and miyakamides. Generally the secondary metabolite capability of A. oryzae presents several novel end products likely to result from the domestication process from A. flavus. PMID:24957367

Metabolomics by Proton High-Resolution Magic-Angle-Spinning Nuclear Magnetic Resonance of Tomato Plants Treated with Two Secondary Metabolites Isolated from Trichoderma.

PubMed

Mazzei, Pierluigi; Vinale, Francesco; Woo, Sheridan Lois; Pascale, Alberto; Lorito, Matteo; Piccolo, Alessandro

2016-05-11

Trichoderma fungi release 6-pentyl-2H-pyran-2-one (1) and harzianic acid (2) secondary metabolites to improve plant growth and health protection. We isolated metabolites 1 and 2 from Trichoderma strains, whose different concentrations were used to treat seeds of Solanum lycopersicum. The metabolic profile in the resulting 15 day old tomato leaves was studied by high-resolution magic-angle-spinning nuclear magnetic resonance (HRMAS NMR) spectroscopy directly on the whole samples without any preliminary extraction. Principal component analysis (PCA) of HRMAS NMR showed significantly enhanced acetylcholine and γ-aminobutyric acid (GABA) content accompanied by variable amount of amino acids in samples treated with both Trichoderma secondary metabolites. Seed germination rates, seedling fresh weight, and the metabolome of tomato leaves were also dependent upon doses of metabolites 1 and 2 treatments. HRMAS NMR spectroscopy was proven to represent a rapid and reliable technique for evaluating specific changes in the metabolome of plant leaves and calibrating the best concentration of bioactive compounds required to stimulate plant growth.

IMG-ABC: A Knowledge Base To Fuel Discovery of Biosynthetic Gene Clusters and Novel Secondary Metabolites.

PubMed

Hadjithomas, Michalis; Chen, I-Min Amy; Chu, Ken; Ratner, Anna; Palaniappan, Krishna; Szeto, Ernest; Huang, Jinghua; Reddy, T B K; Cimermančič, Peter; Fischbach, Michael A; Ivanova, Natalia N; Markowitz, Victor M; Kyrpides, Nikos C; Pati, Amrita

2015-07-14

In the discovery of secondary metabolites, analysis of sequence data is a promising exploration path that remains largely underutilized due to the lack of computational platforms that enable such a systematic approach on a large scale. In this work, we present IMG-ABC (https://img.jgi.doe.gov/abc), an atlas of biosynthetic gene clusters within the Integrated Microbial Genomes (IMG) system, which is aimed at harnessing the power of "big" genomic data for discovering small molecules. IMG-ABC relies on IMG's comprehensive integrated structural and functional genomic data for the analysis of biosynthetic gene clusters (BCs) and associated secondary metabolites (SMs). SMs and BCs serve as the two main classes of objects in IMG-ABC, each with a rich collection of attributes. A unique feature of IMG-ABC is the incorporation of both experimentally validated and computationally predicted BCs in genomes as well as metagenomes, thus identifying BCs in uncultured populations and rare taxa. We demonstrate the strength of IMG-ABC's focused integrated analysis tools in enabling the exploration of microbial secondary metabolism on a global scale, through the discovery of phenazine-producing clusters for the first time in Alphaproteobacteria. IMG-ABC strives to fill the long-existent void of resources for computational exploration of the secondary metabolism universe; its underlying scalable framework enables traversal of uncovered phylogenetic and chemical structure space, serving as a doorway to a new era in the discovery of novel molecules. IMG-ABC is the largest publicly available database of predicted and experimental biosynthetic gene clusters and the secondary metabolites they produce. The system also includes powerful search and analysis tools that are integrated with IMG's extensive genomic/metagenomic data and analysis tool kits. As new research on biosynthetic gene clusters and secondary metabolites is published and more genomes are sequenced, IMG-ABC will continue to expand, with the goal of becoming an essential component of any bioinformatic exploration of the secondary metabolism world. Copyright © 2015 Hadjithomas et al.

Identification of potential herbal inhibitor of acetylcholinesterase associated Alzheimer's disorders using molecular docking and molecular dynamics simulation.

PubMed

Seniya, Chandrabhan; Khan, Ghulam Jilani; Uchadia, Kuldeep

2014-01-01

Cholinesterase inhibitors (ChE-Is) are the standard for the therapy of AD associated disorders and are the only class of approved drugs by the Food and Drug Administration (FDA). Additionally, acetylcholinesterase (AChE) is the target for many Alzheimer's dementia drugs which block the function of AChE but have some side effects. Therefore, in this paper, an attempt was made to elucidate cholinesterase inhibition potential of secondary metabolite from Cannabis plant which has negligible or no side effect. Molecular docking of 500 herbal compounds, against AChE, was performed using Autodock 4.2 as per the standard protocols. Molecular dynamics simulations have also been carried out to check stability of binding complex in water for 1000 ps. Our molecular docking and simulation have predicted high binding affinity of secondary metabolite (C28H34N2O6) to AChE. Further, molecular dynamics simulations for 1000 ps suggest that ligand interaction with the residues Asp72, Tyr70-121-334, and Phe288 of AChE, all of which fall under active site/subsite or binding pocket, might be critical for the inhibitory activity of AChE. This approach might be helpful to understand the selectivity of the given drug molecule in the treatment of Alzheimer's disease. The study provides evidence for consideration of C28H34N2O6 as a valuable small ligand molecule in treatment and prevention of AD associated disorders and further in vitro and in vivo investigations may prove its therapeutic potential.

Identification of Potential Herbal Inhibitor of Acetylcholinesterase Associated Alzheimer's Disorders Using Molecular Docking and Molecular Dynamics Simulation

PubMed Central

Seniya, Chandrabhan; Khan, Ghulam Jilani; Uchadia, Kuldeep

2014-01-01

Cholinesterase inhibitors (ChE-Is) are the standard for the therapy of AD associated disorders and are the only class of approved drugs by the Food and Drug Administration (FDA). Additionally, acetylcholinesterase (AChE) is the target for many Alzheimer's dementia drugs which block the function of AChE but have some side effects. Therefore, in this paper, an attempt was made to elucidate cholinesterase inhibition potential of secondary metabolite from Cannabis plant which has negligible or no side effect. Molecular docking of 500 herbal compounds, against AChE, was performed using Autodock 4.2 as per the standard protocols. Molecular dynamics simulations have also been carried out to check stability of binding complex in water for 1000 ps. Our molecular docking and simulation have predicted high binding affinity of secondary metabolite (C28H34N2O6) to AChE. Further, molecular dynamics simulations for 1000 ps suggest that ligand interaction with the residues Asp72, Tyr70-121-334, and Phe288 of AChE, all of which fall under active site/subsite or binding pocket, might be critical for the inhibitory activity of AChE. This approach might be helpful to understand the selectivity of the given drug molecule in the treatment of Alzheimer's disease. The study provides evidence for consideration of C28H34N2O6 as a valuable small ligand molecule in treatment and prevention of AD associated disorders and further in vitro and in vivo investigations may prove its therapeutic potential. PMID:25054066

Exploring plant tissue culture in Withania somnifera (L.) Dunal: in vitro propagation and secondary metabolite production.

PubMed

Shasmita; Rai, Manoj K; Naik, Soumendra K

2017-12-26

Withania somnifera (L.) Dunal (family: Solanaceae), commonly known as "Indian Ginseng", is a medicinally and industrially important plant of the Indian subcontinent and other warmer parts of the world. The plant has multi-use medicinal potential and has been listed among 36 important cultivated medicinal plants of India that are in high demand for trade due to its pharmaceutical uses. The medicinal importance of this plant is mainly due to the presence of different types of steroidal lactones- withanolides in the roots and leaves. Owing to low seed viability and poor germination, the conventional propagation of W. somnifera falls short to cater its commercial demands particularly for secondary metabolite production. Therefore, there is a great need to develop different biotechnological approaches through tissue and organ culture for seasonal independent production of plants in large scale which will provide sufficient raw materials of uniform quality for pharmaceutical purposes. During past years, a number of in vitro plant regeneration protocols via organogenesis and somatic embryogenesis and in vitro conservation through synthetic seed based encapsulation technology have been developed for W. somnifera. Several attempts have also been made to standardize the protocol of secondary metabolite production via tissue/organ cultures, cell suspension cultures, and Agrobacterium rhizogenes-mediated transformed hairy root cultures. Employment of plant tissue culture based techniques would provide means for rapid propagation and conservation of this plant species and also provide scope for enhanced production of different bioactive secondary metabolites. The present review provides a comprehensive report on research activities conducted in the area of tissue culture and secondary metabolite production in W. somnifera during the past years. It also discusses the unexplored areas which might be taken into consideration for future research so that the medicinal properties and the secondary metabolites produced by this plant can be exploited further for the benefit of human health in a sustainable way.

Effects of Increasing Doses of UV-B on Main Phenolic Acids Content, Antioxidant Activity and Estimated Biomass in Lavandin (Lavandula x intermedia).

PubMed

Usano-Alemany, Jaime; Panjai, Lachinee

2015-07-01

Lavandin is a well-known aromatic plant cultivated mainly for its valuable essential oil. Nonetheless, little attention has been paid so far to the quantification of other natural products such as polyphenols. Accordingly, we examined the effect of increasing doses of UV-B radiation on the main phenolic content, antioxidant activity and estimated biomass of one year old lavandin pots compared with pots grown outdoors. Significantly higher total phenolic content and concentration of main polyphenols have been found in outdoor plants. Rosmarinic acid has been described as the major phenolic compound in methanolic extracts (max. 25.9 ± 9.7 mg/g(-1) DW). Furthermore, we found that increasing doses of UV-B promote the plant growth of this species as well as the accumulation of phenolic compounds although with less antioxidant capacity in scavenging DPPH radicals. On the other hand, our results showed a remarkable variability among individual plants regarding the content of major phenolic acids. The application of UV-B doses during plant growth could be a method to promote biomass in this species along with the promotion of higher content of valuable secondary metabolites.

Key role of LaeA and velvet complex proteins on expression of β-lactam and PR-toxin genes in Penicillium chrysogenum: cross-talk regulation of secondary metabolite pathways.

PubMed

Martín, Juan F

2017-05-01

Penicillium chrysogenum is an excellent model fungus to study the molecular mechanisms of control of expression of secondary metabolite genes. A key global regulator of the biosynthesis of secondary metabolites is the LaeA protein that interacts with other components of the velvet complex (VelA, VelB, VelC, VosA). These components interact with LaeA and regulate expression of penicillin and PR-toxin biosynthetic genes in P. chrysogenum. Both LaeA and VelA are positive regulators of the penicillin and PR-toxin biosynthesis, whereas VelB acts as antagonist of the effect of LaeA and VelA. Silencing or deletion of the laeA gene has a strong negative effect on penicillin biosynthesis and overexpression of laeA increases penicillin production. Expression of the laeA gene is enhanced by the P. chrysogenum autoinducers 1,3 diaminopropane and spermidine. The PR-toxin gene cluster is very poorly expressed in P. chrysogenum under penicillin-production conditions (i.e. it is a near-silent gene cluster). Interestingly, the downregulation of expression of the PR-toxin gene cluster in the high producing strain P. chrysogenum DS17690 was associated with mutations in both the laeA and velA genes. Analysis of the laeA and velA encoding genes in this high penicillin producing strain revealed that both laeA and velA acquired important mutations during the strain improvement programs thus altering the ratio of different secondary metabolites (e.g. pigments, PR-toxin) synthesized in the high penicillin producing mutants when compared to the parental wild type strain. Cross-talk of different secondary metabolite pathways has also been found in various Penicillium spp.: P. chrysogenum mutants lacking the penicillin gene cluster produce increasing amounts of PR-toxin, and mutants of P. roqueforti silenced in the PR-toxin genes produce large amounts of mycophenolic acid. The LaeA-velvet complex mediated regulation and the pathway cross-talk phenomenon has great relevance for improving the production of novel secondary metabolites, particularly of those secondary metabolites which are produced in trace amounts encoded by silent or near-silent gene clusters.

Secondary Metabolites, Glandular Trichomes and Biological Activity of Sideritis montana L. subsp. montana from Central Italy.

PubMed

Venditti, Alessandro; Bianco, Armandodoriano; Frezza, Claudio; Serafini, Mauro; Giacomello, Ginevra; Giuliani, Claudia; Bramucci, Massimo; Quassinti, Luana; Lupidi, Giulio; Lucarini, Domenico; Papa, Fabrizio; Maggi, Filippo

2016-10-01

Sideritis montana subsp. montana is a small annual herb occurring in countries bordering the Mediterranean and Balkan regions. The secondary metabolism of this plant has not been fully explored so far. The aim of the present study was to understand the complex mixture of secondary metabolites and the type of secretory structures. The polar constituents were isolated by column chromatography from the ethanolic extract, and their structure was elucidated by NMR and MS. The essential oil was isolated by hydrodistillation and analysed by GC/MS. The plant indumentum was studied by light and scanning electron microscopy. To complete the work, the essential oil antioxidant activity and cytotoxicity on tumor cells were evaluated by DPPH, ABTS, FRAP, and MTT methods. Four different classes of secondary metabolites were isolated, namely flavonoids, caffeoylquinic derivatives, glycosidic hydroquinones and iridoids. The essential oil was mainly characterized by sesquiterpenene hydrocarbons. Peltate and long-capitate hairs were the main sites where terpenes and polar constituents are produced. The secondary metabolites found in S. montana subsp. montana are of chemotaxonomic interest, some of them being typical of the genus Sideritis. The trichomes types observed partially differ from those described in other members of the genus Sideritis. The essential oil showed noteworthy inhibition on tumor cells. © 2016 Wiley-VHCA AG, Zürich.

Uptake of Seeds Secondary Metabolites by Virola surinamensis Seedlings

PubMed Central

Kato, Massuo Jorge; Yoshida, Massayoshi; Lopes, Norberto Peporine; da Silva, Denise Brentan; Cavalheiro, Alberto José

2012-01-01

The major secondary metabolites and fatty acids occurring in the seeds of Virola surinamensis were monitored by GC-MS during germination and seedling development. The role as carbon source for seedling development was indicated considering that both classes of compounds were similarly consumed in the seeds and that no selective consumption of compounds could be detected. PMID:22505921

Deciphering the cryptic genome: Genome-wide analyses of the rice pathogen Fusarium fujikuroi reveal complex regulation of secondary metabolism and novel metabolites

USDA-ARS?s Scientific Manuscript database

The fungus Fusarium fujikuroi is agriculturally important because it produces the phytohormones gibberellic acids (GAs) and causes bakanae (“foolish seedling”) disease of rice. The fungus also produces multiple other secondary metabolites, including pigments and mycotoxins. Here, we present a high-q...

Effect of different ecological conditions on secondary metabolite production and gene expression in two mycotoxigenic plant pathogen Fusarium species: F. verticillioides and F. equiseti

USDA-ARS?s Scientific Manuscript database

The genus Fusarium includes many species that are plant pathogens and many produce harmful secondary metabolites including fumonisins and trichothecenes. These mycotoxins can cause disease in animals and have been associated with cancers and birth defects in humans. Many factors influence the produc...

Aeroplysinin-1, a Sponge-Derived Multi-Targeted Bioactive Marine Drug

PubMed Central

García-Vilas, Javier A.; Martínez-Poveda, Beatriz; Quesada, Ana R.; Medina, Miguel Ángel

2015-01-01

Organisms lacking external defense mechanisms have developed chemical defense strategies, particularly through the production of secondary metabolites with antibiotic or repellent effects. Secondary metabolites from marine organisms have proven to be an exceptionally rich source of small molecules with pharmacological activities potentially beneficial to human health. (+)-Aeroplysinin-1 is a secondary metabolite isolated from marine sponges with a wide spectrum of bio-activities. (+)-Aeroplysinin-1 has potent antibiotic effects on Gram-positive bacteria and several dinoflagellate microalgae causing toxic blooms. In preclinical studies, (+)-aeroplysinin-1 has been shown to have promising anti-inflammatory, anti-angiogenic and anti-tumor effects. Due to its versatility, (+)-aeroplysinin-1 might have a pharmaceutical interest for the treatment of different pathologies. PMID:26703630

Does Osmotic Stress Affect Natural Product Expression in Fungi?

PubMed Central

Overy, David; Chi, Wei-Chiung; Pang, Ka-Lai; Rateb, Mostafa; Shang, Zhuo; Capon, Rob; Bills, Gerald; Kerr, Russell

2017-01-01

The discovery of new natural products from fungi isolated from the marine environment has increased dramatically over the last few decades, leading to the identification of over 1000 new metabolites. However, most of the reported marine-derived species appear to be terrestrial in origin yet at the same time, facultatively halo- or osmotolerant. An unanswered question regarding the apparent chemical productivity of marine-derived fungi is whether the common practice of fermenting strains in seawater contributes to enhanced secondary metabolism? To answer this question, a terrestrial isolate of Aspergillus aculeatus was fermented in osmotic and saline stress conditions in parallel across multiple sites. The ex-type strain of A. aculeatus was obtained from three different culture collections. Site-to-site variations in metabolite expression were observed, suggesting that subculturing of the same strain and subtle variations in experimental protocols can have pronounced effects upon metabolite expression. Replicated experiments at individual sites indicated that secondary metabolite production was divergent between osmotic and saline treatments. Titers of some metabolites increased or decreased in response to increasing osmolite (salt or glycerol) concentrations. Furthermore, in some cases, the expression of some secondary metabolites in relation to osmotic and saline stress was attributed to specific sources of the ex-type strains. PMID:28805714

Whole-genome sequencing of Aspergillus tubingensis G131 and overview of its secondary metabolism potential.

PubMed

Choque, Elodie; Klopp, Christophe; Valiere, Sophie; Raynal, José; Mathieu, Florence

2018-03-15

Black Aspergilli represent one of the most important fungal resources of primary and secondary metabolites for biotechnological industry. Having several black Aspergilli sequenced genomes should allow targeting the production of certain metabolites with bioactive properties. In this study, we report the draft genome of a black Aspergilli, A. tubingensis G131, isolated from a French Mediterranean vineyard. This 35 Mb genome includes 10,994 predicted genes. A genomic-based discovery identifies 80 secondary metabolites biosynthetic gene clusters. Genomic sequences of these clusters were blasted on 3 chosen black Aspergilli genomes: A. tubingensis CBS 134.48, A. niger CBS 513.88 and A. kawachii IFO 4308. This comparison highlights different levels of clusters conservation between the four strains. It also allows identifying seven unique clusters in A. tubingensis G131. Moreover, the putative secondary metabolites clusters for asperazine and naphtho-gamma-pyrones production were proposed based on this genomic analysis. Key biosynthetic genes required for the production of 2 mycotoxins, ochratoxin A and fumonisin, are absent from this draft genome. Even if intergenic sequences of these mycotoxins biosynthetic pathways are present, this could not lead to the production of those mycotoxins by A. tubingensis G131. Functional and bioinformatics analyses of A. tubingensis G131 genome highlight its potential for metabolites production in particular for TAN-1612, asperazine and naphtho-gamma-pyrones presenting antioxidant, anticancer or antibiotic properties.

Serratia marcescens Cyclic AMP Receptor Protein Controls Transcription of EepR, a Novel Regulator of Antimicrobial Secondary Metabolites.

PubMed

Stella, Nicholas A; Lahr, Roni M; Brothers, Kimberly M; Kalivoda, Eric J; Hunt, Kristin M; Kwak, Daniel H; Liu, Xinyu; Shanks, Robert M Q

2015-08-01

Serratia marcescens generates secondary metabolites and secreted enzymes, and it causes hospital infections and community-acquired ocular infections. Previous studies identified cyclic AMP (cAMP) receptor protein (CRP) as an indirect inhibitor of antimicrobial secondary metabolites. Here, we identified a putative two-component regulator that suppressed crp mutant phenotypes. Evidence supports that the putative response regulator eepR was directly transcriptionally inhibited by cAMP-CRP. EepR and the putative sensor kinase EepS were necessary for the biosynthesis of secondary metabolites, including prodigiosin- and serratamolide-dependent phenotypes, swarming motility, and hemolysis. Recombinant EepR bound to the prodigiosin and serratamolide promoters in vitro. Together, these data introduce a novel regulator of secondary metabolites that directly connects the broadly conserved metabolism regulator CRP with biosynthetic genes that may contribute to competition with other microbes. This study identifies a new transcription factor that is directly controlled by a broadly conserved transcription factor, CRP. CRP is well studied in its role to help bacteria respond to the amount of nutrients in their environment. The new transcription factor EepR is essential for the bacterium Serratia marcescens to produce two biologically active compounds, prodigiosin and serratamolide. These two compounds are antimicrobial and may allow S. marcescens to compete for limited nutrients with other microorganisms. Results from this study tie together the CRP environmental nutrient sensor with a new regulator of antimicrobial compounds. Beyond microbial ecology, prodigiosin and serratamolide have therapeutic potential; therefore, understanding their regulation is important for both applied and basic science. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Pseudohypericin and hyperforin in Hypericum perforatum from Northern Turkey: variation among populations, plant parts and phenological stages.

PubMed

Cirak, Cüneyt; Radusiene, Jolita; Janulis, Valdimaras; Ivanauskas, Liudas

2008-05-01

Hypericum perforatum is a perennial medicinal plant known as "St. John's wort" in Western Europe and has been used in the treatment of several diseases for centuries. In the present study, morphologic, phenologic and population variability in pseudohypericin and hyperforin concentrations among H. perforatum populations from Northern Turkey was investigated for the first time. The aerial parts of H. perforatum plants representing a total of 30 individuals were collected at full flowering from 10 sites of Northern Turkey to search the regional variation in the secondary metabolite concentrations. For morphologic and phenologic sampling, plants from one site were gathered in five phenological stages: vegetative, floral budding, full flowering, fresh fruiting and mature fruiting. The plant materials were air-dried at room temperature and subsequently assayed for chemical concentrations by high performance liquid chromatography. Secondary metabolite concentrations ranged from traces to 2.94 mg/g dry weight (DW) for pseudohypericin and traces -6.29 mg/g DW for hyperforin. The differences in the secondary metabolite concentrations among populations of H. perforatum were found to be significant. The populations varied greatly in hyperforin concentrations, whereas they produced a similar amount of pseudohypericin. Concentrations of both secondary metabolites in all tissues increased with advancing of plant development and higher accumulation levels were reached at flowering. Among different tissues, full opened flowers were found to be superior to stems, leaves and the other reproductive parts with regard to pseudohypericin and hyperforin accumulations. The present findings might be useful to optimize the processing methodology of wild-harvested plant material and obtain increased concentrations of these secondary metabolites.

High Triterpenic Acids Production in Callus Cultures from Fruit Pulp of Two Apple Varieties.

PubMed

Verardo, Giancarlo; Gorassini, Andrea; Ricci, Donata; Fraternale, Daniele

2017-01-01

Very rarely fruit pulp has been used in in vitro culture to produce secondary metabolites useful in promoting health. The aims of this work were the study of the best conditions to obtain the callus cultures from the pulp of two varieties of apples, Golden Delicious (GD) and "Mela Rosa Marchigiana" (MRM), and the quali-quantitative analysis of secondary metabolites produced by the two in vitro callus cultures. Callus was induced on both Murashige and Skoog and Gamborg B5 media containing various combinations of supplements. To achieve the maximum recovery of secondary metabolites produced, preliminary extraction tests were carried out on GD apple culture using two different organic solvents (MeOH and EtOAc). The quali-quantitative analysis of the methanolic extract of both cultures was carried out by ESI-MS n and GC-MS techniques. The GC-MS analysis revealed the presence of triterpenic acids, in particular, oleanolic, ursolic, maslinic, pomolic, tormentic, corosolic and annurcoic acid along with a phytosterol, β-sitosterol. In addition, GD callus culture produced phloridzin, absent in the MRM culture. In this last culture, however, the total amount of secondary metabolites was markedly higher. The in vivo production of these bioactive compounds were also quantified in the GD and MRM apple pulps. Apple pulps produced higher amounts of triterpenic acids in vitro than in vivo. The present work can be considered a method to amplify the production of important secondary metabolites which exert beneficial effects on human health. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Cytoplasmic Acidification and Secondary Metabolite Production in Different Plant Cell Suspensions (A Comparative Study).

PubMed Central

Hagendoorn, MJM.; Wagner, A. M.; Segers, G.; Van Der Plas, LHW.; Oostdam, A.; Van Walraven, H. S.

1994-01-01

In this study, a correlation is described between low cytoplasmic pH, measured with the fluorescent probes 2[prime],7[prime]-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (acetoxymethyl ester) and bis- [3-propyl-5-oxoisoxazol-4-yl]pentamethine oxonol, and the production of secondary metabolites for several plant cell-suspension systems. Anthraquinone production in Morinda citrifolia suspensions is negligible in the presence of 2,4-dichlorophenoxyacetic acid (2,4-D), whereas with naphthalene acetic acid (NAA) a significant accumulation is realized. NAA-grown cells showed a lower cytoplasmic pH than did 2,4-D-grown cells. Addition of 2,4-D or parachlorophenoxy acetic acid to NAA-grown cells resulted in an inhibition of anthraquinone production and an increase of the cytoplasmic pH, whereas addition of parachlorophenyl acetic acid had no effect on either parameter. Lignin production in Petunia hybrida cells could be induced by subculturing them in a medium without iron. These cells showed a lower cytoplasmic pH than control cells. Addition of Fe3+ led to a decreased lignin content and an increased cytoplasmic pH. Two cell lines of Linum flavum showed a different level of coniferin and lignin concentration in their cells. Cells that accumulated coniferin and lignin had a lower cytoplasmic pH than cells that did not accumulate these secondary metabolites. Apparently, in different species and after different kinds of treatment there is a correlation between acidification of the cytoplasm and the production of different secondary metabolites. The possible role of this acidification in secondary metabolite production is discussed. PMID:12232364

Cytoplasmic Acidification and Secondary Metabolite Production in Different Plant Cell Suspensions (A Comparative Study).

PubMed

Hagendoorn, MJM.; Wagner, A. M.; Segers, G.; Van Der Plas, LHW.; Oostdam, A.; Van Walraven, H. S.

1994-10-01

In this study, a correlation is described between low cytoplasmic pH, measured with the fluorescent probes 2[prime],7[prime]-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (acetoxymethyl ester) and bis- [3-propyl-5-oxoisoxazol-4-yl]pentamethine oxonol, and the production of secondary metabolites for several plant cell-suspension systems. Anthraquinone production in Morinda citrifolia suspensions is negligible in the presence of 2,4-dichlorophenoxyacetic acid (2,4-D), whereas with naphthalene acetic acid (NAA) a significant accumulation is realized. NAA-grown cells showed a lower cytoplasmic pH than did 2,4-D-grown cells. Addition of 2,4-D or parachlorophenoxy acetic acid to NAA-grown cells resulted in an inhibition of anthraquinone production and an increase of the cytoplasmic pH, whereas addition of parachlorophenyl acetic acid had no effect on either parameter. Lignin production in Petunia hybrida cells could be induced by subculturing them in a medium without iron. These cells showed a lower cytoplasmic pH than control cells. Addition of Fe3+ led to a decreased lignin content and an increased cytoplasmic pH. Two cell lines of Linum flavum showed a different level of coniferin and lignin concentration in their cells. Cells that accumulated coniferin and lignin had a lower cytoplasmic pH than cells that did not accumulate these secondary metabolites. Apparently, in different species and after different kinds of treatment there is a correlation between acidification of the cytoplasm and the production of different secondary metabolites. The possible role of this acidification in secondary metabolite production is discussed.

Effects of high salt stress on secondary metabolite production in the marine-derived fungus Spicaria elegans.

PubMed

Wang, Yi; Lu, Zhenyu; Sun, Kunlai; Zhu, Weiming

2011-01-01

To obtain structurally novel and bioactive natural compounds from marine-derived microorganisms, the effect of high salt stress on secondary metabolite production in the marine-derived fungal strain, Spicaria elegans KLA-03, was investigated. The organism, which was isolated from marine sediment, produced different secondary metabolites when cultured in 3% and 10% saline conditions. Four characteristic metabolites, only produced in the 10% salinity culture, were isolated, and their structures were identified as (2E,2'Z)-3,3'-(6,6'-dihydroxybiphenyl-3,3'-diyl)diacrylic acid (1), aspulvinone E (2), aspochalasin E (3) and trichodermamide B (6), according to their 1D and 2D NMR spectra. Compound 1 is a new compound. High salt stress may therefore be a promising means to induce the production of new and chlorinated compounds in halotolerant fungi. Compound 1 showed moderate antibacterial activity against Pseudomonas aeruginosa and Escherichia coli with minimum inhibitory concentration (MIC) values of 0.038 and 0.767 mM, respectively.

Comprehensive MS and Solid-State NMR Metabolomic Profiling Reveals Molecular Variations in Native Periderms from Four Solanum tuberosum Potato Cultivars.

PubMed

Huang, Wenlin; Serra, Olga; Dastmalchi, Keyvan; Jin, Liqing; Yang, Lijia; Stark, Ruth E

2017-03-15

The potato (Solanum tuberosum L.) ranks third in worldwide consumption among food crops. Whereas disposal of potato peels poses significant challenges for the food industry, secondary metabolites in these tissues are also bioactive and essential to crop development. The diverse primary and secondary metabolites reported in whole tubers and wound-healing tissues prompted a comprehensive profiling study of native periderms from four cultivars with distinctive skin morphologies and commercial food uses. Polar and nonpolar soluble metabolites were extracted concurrently, analyzed chromatographically, and characterized with mass spectrometry; the corresponding solid interfacial polymeric residue was examined by solid-state 13 C NMR. In total, 112 secondary metabolites were found in the phellem tissues; multivariate analysis identified 10 polar and 30 nonpolar potential biomarkers that distinguish a single cultivar among Norkotah Russet, Atlantic, Chipeta, and Yukon Gold cultivars which have contrasting russeting features. Compositional trends are interpreted in the context of periderm protective function.

Species-level assessment of secondary metabolite diversity among Hamigera species and a taxonomic note on the genus

PubMed Central

Igarashi, Yasuhiro; Hanafusa, Tomoaki; Gohda, Fumiya; Peterson, Stephen; Bills, Gerald

2014-01-01

Secondary metabolite phenotypes in nine species of the Hamigera clade were analysed to assess their correlations to a multi-gene species-level phylogeny. High-pressure-liquid-chromatography-based chemical analysis revealed three distinctive patterns of secondary metabolite production: (1) the nine species could be divided into two groups on the basis of production of the sesquiterpene tricinonoic acid; (2) the tricinonoic acid-producing group produced two cyclic peptides avellanins A and B; (3) the tricinonoic acid-non-producing group could be further divided into two groups according to the production of avellanins A and B. The chemical phenotype was consistent with the phylogeny of the species, although metabolite patterns were not diagnostic at the species level. In addition, the taxonomy of the Hamigera clade was updated with the new combination Hamigera ingelheimensis proposed for Merimbla ingelheimensis, so that all species in the clade are now in the same genus. PMID:25379334

Antioxidant activities of phenolic compounds isolated from the leaves of Macaranga allorobinsonii Whitmore

NASA Astrophysics Data System (ADS)

Darmawan, Akhmad; Fajriah, Sofa; Megawati, Dewijanti, Indah D.; Banjarnahor, Sofna; Yuliani, Tri; Hartati, Sri; Mozef, Tjandrawati; Effendi, Ruslan; Swandiny, Greesty F.

2017-01-01

Two secondary metabolites compounds, gallic acid (1) and methyl gallate (2) have been isolated from the ethyl acetate fraction of the methanol extract of the leaves of Macaranga allorobinsonii Whitmore. Isolation and purification of the secondary metabolite compounds conducted using chromatography methods, and structure elucidation determined based on NMR, mass spectroscopic data and compared with appropriate references.

Taxonomic Characterization and Secondary Metabolite Profiling of Aspergillus Section Aspergillus Contaminating Feeds and Feedstuffs.

PubMed

Greco, Mariana; Kemppainen, Minna; Pose, Graciela; Pardo, Alejandro

2015-09-02

Xerophilic fungal species of the genus Aspergillus are economically highly relevant due to their ability to grow on low water activity substrates causing spoilage of stored goods and animal feeds. These fungi can synthesize a variety of secondary metabolites, many of which show animal toxicity, creating a health risk for food production animals and to humans as final consumers, respectively. Animal feeds used for rabbit, chinchilla and rainbow trout production in Argentina were analysed for the presence of xerophilic Aspergillus section Aspergillus species. High isolation frequencies (>60%) were detected in all the studied rabbit and chinchilla feeds, while the rainbow trout feeds showed lower fungal charge (25%). These section Aspergillus contaminations comprised predominantly five taxa. Twenty isolates were subjected to taxonomic characterization using both ascospore SEM micromorphology and two independent DNA loci sequencing. The secondary metabolite profiles of the isolates were determined qualitatively by HPLC-MS. All the isolates produced neoechinulin A, 17 isolates were positive for cladosporin and echinulin, and 18 were positive for neoechinulin B. Physcion and preechinulin were detected in a minor proportion of the isolates. This is the first report describing the detailed species composition and the secondary metabolite profiles of Aspergillus section Aspergillus contaminating animal feeds.

Chemical epigenetics alters the secondary metabolite composition of guttate excreted by an atlantic-forest-soil-derived Penicillium citreonigrum.

PubMed

Wang, Xiaoru; Sena Filho, José G; Hoover, Ashley R; King, Jarrod B; Ellis, Trevor K; Powell, Douglas R; Cichewicz, Robert H

2010-05-28

Chemical epigenetic manipulation of Penicillium citreonigrum led to profound changes in the secondary metabolite profile of its guttate. While guttate from control cultures exhibited a relatively simple assemblage of secondary metabolites, the guttate collected from cultures treated with 50 muM 5-azacytidine (a DNA methyltransferase inhibitor) was highly enriched in compounds representing at least three distinct biosynthetic families. The metabolites obtained from the fungus included six azaphilones (sclerotiorin (1), sclerotioramine (6), ochrephilone (2), dechloroisochromophilone III (3), dechloroisochromophilone IV (4), and 6-((3E,5E)-5,7-dimethyl-2-methylenenona-3,5-dienyl)-2,4-dihydroxy-3-methylbenzaldehyde (5)), pencolide (7), and two new meroterpenes (atlantinones A and B (9 and 10, respectively)). While pencolide was detected in the exudates of both control and 5-azacytidine-treated cultures, all of the other natural products were found exclusively in the guttates of the epigenetically modified fungus. All of the metabolites from the P. citreonigrum guttate were tested for antimicrobial activity in a disk diffusion assay. Both sclerotiorin and sclerotioramine caused modest inhibition of Staphylococcus epidermidis growth; however, only sclerotioramine was active against a panel of Candida strains.

Secondary Metabolites Produced by an Endophytic Fungus Pestalotiopsis sydowiana and Their 20S Proteasome Inhibitory Activities.

PubMed

Xia, Xuekui; Kim, Soonok; Liu, Changheng; Shim, Sang Hee

2016-07-20

Fungal endophytes have attracted attention due to their functional diversity. Secondary metabolites produced by Pestalotiopsis sydowiana from a halophyte, Phragmites communis Trinus, were investigated. Eleven compounds, including four penicillide derivatives (1-4) and seven α-pyrone analogues (5-10) were isolated from cultures of P. sydowiana. The compounds were identified based on spectroscopic data. The inhibitory activities against the 20S proteasome were evaluated. Compounds 1-3, 5, and 9-10 showed modest proteasome inhibition activities, while compound 8 showed strong activity with an IC50 of 1.2 ± 0.3 μM. This is the first study on the secondary metabolites produced by P. sydowiana and their proteasome inhibitory activities. The endophytic fungus P. sydowiana might be a good resource for proteasome inhibitors.

[Cytotoxicity of the secondary metabolites of Marine Mangrove Fungus Paecilomyces sp. tree 1-7 on human hepatoma cell line HepG2].

PubMed

Cai, Xiao-Ling; Gao, Jun-Ping; Li, Qing; Wen, Lu; She, Zhi-Gang; Lin, Yong-Cheng

2008-06-01

To study the cytotoxicity of the secondary metabolites of Marine Mangrove Fungus Paecilomyces sp. Tree 1-7 on human hepatoma cell line HepG2 cultured in vitro. Three groups were divided: compounds group, 5-Fu group and control group. The cytotoxicity was measured by MTT method when HepG2 cells were treated by different concentration of the secondary metabolites of Paecilomyces sp. Tree 1-7. Secalonic acid A, tenellic acid A and alternin inhibited the growth of human hepatoma cell line HepG2, the IC50 separately were 2.0, 62.1 and 7.0 microg/ml. Secalonic acid A and alternin have strong cytotoxicity on HepG2 cultured in vitro.

Activation and products of the cryptic secondary metabolite biosynthetic gene clusters by rifampin resistance (rpoB) mutations in actinomycetes.

PubMed

Tanaka, Yukinori; Kasahara, Ken; Hirose, Yutaka; Murakami, Kiriko; Kugimiya, Rie; Ochi, Kozo

2013-07-01

A subset of rifampin resistance (rpoB) mutations result in the overproduction of antibiotics in various actinomycetes, including Streptomyces, Saccharopolyspora, and Amycolatopsis, with H437Y and H437R rpoB mutations effective most frequently. Moreover, the rpoB mutations markedly activate (up to 70-fold at the transcriptional level) the cryptic/silent secondary metabolite biosynthetic gene clusters of these actinomycetes, which are not activated under general stressful conditions, with the exception of treatment with rare earth elements. Analysis of the metabolite profile demonstrated that the rpoB mutants produced many metabolites, which were not detected in the wild-type strains. This approach utilizing rifampin resistance mutations is characterized by its feasibility and potential scalability to high-throughput studies and would be useful to activate and to enhance the yields of metabolites for discovery and biochemical characterization.

Epigenetic modifiers alter the secondary metabolite composition of a plant endophytic fungus, Pestalotiopsis crassiuscula obtained from the leaves of Fragaria chiloensis.

PubMed

Yang, Xiao-Long; Huang, Le; Ruan, Xiao-Li

2014-01-01

The addition of the DNA methyltransferase inhibitor 500 μM 5-azacytidine to the culture medium of a plant endophytic fungus, Pestalotiopsis crassiuscula, obtained from the leaves of Fragaria chiloensis, dramatically altered the profiles of its metabolites and resulted in the isolation of one new coumarin (1), along with six known compounds (2-7). HPLC profiles revealed that only compounds 3, 4, and 7 belonged to the new induced secondary metabolites. The structures of all isolated compounds were elucidated on the basis of extensive analysis of NMR spectra.

Optimization of nonribosomal peptides production by a psychrotrophic fungus: Trichoderma velutinum ACR-P1.

PubMed

Sharma, Richa; Singh, Varun P; Singh, Deepika; Yusuf, Farnaz; Kumar, Anil; Vishwakarma, Ram A; Chaubey, Asha

2016-11-01

Trichoderma is an anamorphic filamentous fungal genus with immense potential for production of small valuable secondary metabolites with indispensable biological activities. Microbial dynamics of a psychrotrophic strain Trichoderma velutinum ACR-P1, isolated from unexplored niches of the Shiwalik region, bestowed with rich biodiversity of microflora, was investigated for production of nonribosomal peptides (NRPs) by metabolite profiling by intact-cell mass spectrometry (ICMS) employing matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometer. Being the first report on NRPs production by T. velutinum, studies on optimization of growth conditions by Response Surface Methodology (RSM) for production of NRPs by ACR-P1 was carried out strategically. Multifold enhancement in the yield of NRPs belonging to subfamily SF4 with medium chain of amino acid residues having m/z 1437.9, 1453.9, and 1452.0 at pH 5.9 at 20 °C and of subfamily SF1 with long-chain amino acid residues having m/z 1770.2, 1784.2, 1800.1, 1802.1, and 1815.1 was achieved at pH 7.0 at 25 °C. Complexities of natural mixtures were thus considerably reduced under respective optimized culture conditions accelerating the production of novel microbial natural products by saving time and resources.

Genome-Wide Identification, Characterization and Expression Analysis of the Chalcone Synthase Family in Maize

PubMed Central

Han, Yahui; Ding, Ting; Su, Bo; Jiang, Haiyang

2016-01-01

Members of the chalcone synthase (CHS) family participate in the synthesis of a series of secondary metabolites in plants, fungi and bacteria. The metabolites play important roles in protecting land plants against various environmental stresses during the evolutionary process. Our research was conducted on comprehensive investigation of CHS genes in maize (Zea mays L.), including their phylogenetic relationships, gene structures, chromosomal locations and expression analysis. Fourteen CHS genes (ZmCHS01–14) were identified in the genome of maize, representing one of the largest numbers of CHS family members identified in one organism to date. The gene family was classified into four major classes (classes I–IV) based on their phylogenetic relationships. Most of them contained two exons and one intron. The 14 genes were unevenly located on six chromosomes. Two segmental duplication events were identified, which might contribute to the expansion of the maize CHS gene family to some extent. In addition, quantitative real-time PCR and microarray data analyses suggested that ZmCHS genes exhibited various expression patterns, indicating functional diversification of the ZmCHS genes. Our results will contribute to future studies of the complexity of the CHS gene family in maize and provide valuable information for the systematic analysis of the functions of the CHS gene family. PMID:26828478

Screening of novel actinobacteria and characterization of the potential isolates from mangrove sediment of south coastal India.

PubMed

Arumugam, T; Senthil Kumar, P; Kameshwar, R; Prapanchana, K

2017-06-01

The importance of the current research is to investigate the different types of samples from the various mangrove sediments; as source of actinobacteria from the mangrove wet soil. Potential isolate screening by antimicrobial activity and identified actinobacteria was characterized based on cultural morphology, physiological and biochemical characteristics. Three different types of media were used to isolate actinobacteria from various geographical region of mangrove soil sediment and the genotype locus was recognized by 16S rDNA. Totally 144 actinobacteria isolates were recovered from 10 samples using three media. The most active culture media in the isolation of actinobacteria were ISP2 and Glycerol Yeast Extract Agar. Among 144 isolates, 38 isolates (26.38%) exhibited antimicrobial activity. Out of 38 isolates, potentially active 2 cultures were further supported for morphological and biochemical characterization analysis. Most of the isolates were produced pharmaceutically important enzymes such as protease, amylase, lipase, cellulose and also revealed antimicrobial activity against tested microorganism. The enriched salt, pH and temperature tolerance of the actinobacteria isolates to discharge commercially valuable primary and secondary bioactive metabolites. The present results functionally characterize novel mangrove actinobacteria and their metabolites for commercial interest in pharmaceutical industry. Copyright © 2017 Elsevier Ltd. All rights reserved.

Bioengineering of plant (tri)terpenoids: from metabolic engineering of plants to synthetic biology in vivo and in vitro.

PubMed

Moses, Tessa; Pollier, Jacob; Thevelein, Johan M; Goossens, Alain

2013-10-01

Terpenoids constitute a large and diverse class of natural products that serve many functions in nature. Most of the tens of thousands of the discovered terpenoids are synthesized by plants, where they function as primary metabolites involved in growth and development, or as secondary metabolites that optimize the interaction between the plant and its environment. Several plant terpenoids are economically important molecules that serve many applications as pharmaceuticals, pesticides, etc. Major challenges for the commercialization of plant-derived terpenoids include their low production levels in planta and the continuous demand of industry for novel molecules with new or superior biological activities. Here, we highlight several synthetic biology methods to enhance and diversify the production of plant terpenoids, with a foresight towards triterpenoid engineering, the least engineered class of bioactive terpenoids. Increased or cheaper production of valuable triterpenoids may be obtained by 'classic' metabolic engineering of plants or by heterologous production of the compounds in other plants or microbes. Novel triterpenoid structures can be generated through combinatorial biosynthesis or directed enzyme evolution approaches. In its ultimate form, synthetic biology may lead to the production of large amounts of plant triterpenoids in in vitro systems or custom-designed artificial biological systems. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Complementing in vitro screening assays with in silico ...

EPA Pesticide Factsheets

High-throughput in vitro assays offer a rapid, cost-efficient means to screen thousands of chemicals across hundreds of pathway-based toxicity endpoints. However, one main concern involved with the use of in vitro assays is the erroneous omission of chemicals that are inactive under assay conditions but that can generate active metabolites under in vivo conditions. To address this potential issue, a case study will be presented to demonstrate the use of in silico tools to identify inactive parents with the ability to generate active metabolites. This case study used the results from an orthogonal assay designed to improve confidence in the identification of active chemicals tested across eighteen estrogen receptor (ER)-related in vitro assays by accounting for technological limitations inherent within each individual assay. From the 1,812 chemicals tested within the orthogonal assay, 1,398 were considered inactive. These inactive chemicals were analyzed using Chemaxon Metabolizer software to predict the first and second generation metabolites. From the nearly 1,400 inactive chemicals, over 2,200 first-generation (i.e., primary) metabolites and over 5,500 second-generation (i.e., secondary) metabolites were predicted. Nearly 70% of primary metabolites were immediately detoxified or converted to other metabolites, while over 70% of secondary metabolites remained stable. Among these predicted metabolites, those that are most likely to be produced and remain

Effects of Actinomycete Secondary Metabolites on Sediment Microbial Communities.

PubMed

Patin, Nastassia V; Schorn, Michelle; Aguinaldo, Kristen; Lincecum, Tommie; Moore, Bradley S; Jensen, Paul R

2017-02-15

Marine sediments harbor complex microbial communities that remain poorly studied relative to other biomes such as seawater. Moreover, bacteria in these communities produce antibiotics and other bioactive secondary metabolites, yet little is known about how these compounds affect microbial community structure. In this study, we used next-generation amplicon sequencing to assess native microbial community composition in shallow tropical marine sediments. The results revealed complex communities comprised of largely uncultured taxa, with considerable spatial heterogeneity and known antibiotic producers comprising only a small fraction of the total diversity. Organic extracts from cultured strains of the sediment-dwelling actinomycete genus Salinispora were then used in mesocosm studies to address how secondary metabolites shape sediment community composition. We identified predatory bacteria and other taxa that were consistently reduced in the extract-treated mesocosms, suggesting that they may be the targets of allelopathic interactions. We tested related taxa for extract sensitivity and found general agreement with the culture-independent results. Conversely, several taxa were enriched in the extract-treated mesocosms, suggesting that some bacteria benefited from the interactions. The results provide evidence that bacterial secondary metabolites can have complex and significant effects on sediment microbial communities. Ocean sediments represent one of Earth's largest and most poorly studied biomes. These habitats are characterized by complex microbial communities where competition for space and nutrients can be intense. This study addressed the hypothesis that secondary metabolites produced by the sediment-inhabiting actinomycete Salinispora arenicola affect community composition and thus mediate interactions among competing microbes. Next-generation amplicon sequencing of mesocosm experiments revealed complex communities that shifted following exposure to S. arenicola extracts. The results reveal that certain predatory bacteria were consistently less abundant following exposure to extracts, suggesting that microbial metabolites mediate competitive interactions. Other taxa increased in relative abundance, suggesting a benefit from the extracts themselves or the resulting changes in the community. This study takes a first step toward assessing the impacts of bacterial metabolites on sediment microbial communities. The results provide insight into how low-abundance organisms may help structure microbial communities in ocean sediments. Copyright © 2017 American Society for Microbiology.

Micropropagation of Iris sp.

PubMed

Jevremović, Slađana; Jeknić, Zoran; Subotić, Angelina

2013-01-01

Irises are perennial plants widely used as ornamental garden plants or cut flowers. Some species accumulate secondary metabolites, making them highly valuable to the pharmaceutical and perfume industries. Micropropagation of irises has successfully been accomplished by culturing zygotic embryos, different flower parts, and leaf base tissues as starting explants. Plantlets are regenerated via somatic embryogenesis, organogenesis, or both processes at the same time depending on media composition and plant species. A large number of uniform plants are produced by somatic embryogenesis, however, some species have decreased morphogenetic potential overtime. Shoot cultures obtained by organogenesis can be multiplied for many years. Somatic embryogenic tissue can be reestablished from leaf bases of in vitro-grown shoots. The highest number of plants can be obtained by cell suspension cultures. This chapter describes effective in vitro plant regeneration protocols for Iris species from different types of explants by somatic embryogenesis and/or organogenesis suitable for the mass propagation of ornamental and pharmaceutical irises.

Alliinase and cysteine synthase transcription in developing garlic (Allium sativum L.) over time.

PubMed

Mitrová, Katarina; Svoboda, Pavel; Milella, Luigi; Ovesná, Jaroslava

2018-06-15

Garlic is a valuable source of healthy compounds, including secondary metabolites rich in sulphur such as cysteine sulphoxides (CSOs). Here, we present new qRT-PCR assays analysing the transcription of two genes encoding key enzymes in CSO biosynthetic pathways (cysteine synthase and alliinase) in developing garlic. We also identified a set of genes (ACT I, GAPDH, and TUB) to use as transcription normalisation controls. We showed that the (normalised) transcription of both enzymes was highest during sprouting and decreased significantly in fully developed leaves, which are the major CSO-producing organs. Transcriptional activity further declined at the end of the growing season. Different cultivars show similar sulphur metabolism gene expression when European garlics were compared to Chinese and American genotypes. The qRT-PCR assays presented are also suitable for investigating the effects of agricultural practices on CSO formation in garlic to satisfy consumer demands. Copyright © 2017. Published by Elsevier Ltd.

Marine Peptides and Their Anti-Infective Activities

PubMed Central

Kang, Hee Kyoung; Seo, Chang Ho; Park, Yoonkyung

2015-01-01

Marine bioresources are a valuable source of bioactive compounds with industrial and nutraceutical potential. Numerous clinical trials evaluating novel chemotherapeutic agents derived from marine sources have revealed novel mechanisms of action. Recently, marine-derived bioactive peptides have attracted attention owing to their numerous beneficial effects. Moreover, several studies have reported that marine peptides exhibit various anti-infective activities, such as antimicrobial, antifungal, antimalarial, antiprotozoal, anti-tuberculosis, and antiviral activities. In the last several decades, studies of marine plants, animals, and microbes have revealed tremendous number of structurally diverse and bioactive secondary metabolites. However, the treatments available for many infectious diseases caused by bacteria, fungi, and viruses are limited. Thus, the identification of novel antimicrobial peptides should be continued, and all possible strategies should be explored. In this review, we will present the structures and anti-infective activity of peptides isolated from marine sources (sponges, algae, bacteria, fungi and fish) from 2006 to the present. PMID:25603351

Monoterpenoid biosynthesis in Saccharomyces cerevisiae.

PubMed

Oswald, Marilyne; Fischer, Marc; Dirninger, Nicole; Karst, Francis

2007-05-01

Plant monoterpenoids belong to a large family of plant secondary metabolites with valuable applications in cosmetics and medicine. Their usual low levels and difficult purification justify the need for alternative fermentative processes for large-scale production. Geranyl diphosphate is the universal precursor of monoterpenoids. In yeast it occurs exclusively as an intermediate of farnesyl diphosphate synthesis. In the present study we investigated the potential use of Saccharomyces cerevisiae as an alternative engineering tool. The expression of geraniol synthase of Ocimum basilicum in yeast allowed a strong and specific excretion of geraniol to the growth medium, in contrast to mutants defective in farnesyl diphosphate synthase which excreted geraniol and linalool in similar amounts. A further increase of geraniol synthesis was obtained using yeast mutants defective in farnesyl diphosphate synthase. We also showed that geraniol synthase expression affects the general ergosterol pathway, but in a manner dependent on the genetic background of the strain.

Profiling the Phenolic Compounds of the Four Major Seed Coat Types and Their Relation to Color Genes in Lentil.

PubMed

Mirali, Mahla; Purves, Randy W; Vandenberg, Albert

2017-05-26

Phenolic compounds can provide antioxidant health benefits for humans, and foods such as lentils can be valuable dietary sources of different subclasses of these secondary metabolites. This study used LC-MS analyses to compare the phenolic profiles of lentil genotypes with four seed coat background colors (green, gray, tan, and brown) and two cotyledon colors (red and yellow) grown at two locations. The mean area ratio per mg sample (MARS) values of various phenolic compounds in lentil seeds varied with the different seed coat colors conferred by specific genotypes. Seed coats of lentil genotypes with the homozygous recessive tgc allele (green and gray seed coats) had higher MARS values of flavan-3-ols, proanthocyanidins, and some flavonols. This suggests lentils featuring green and gray seed coats might be more promising as health-promoting foods.

[Morphology, anatomy, ontogeny and chemical composition of inflorescences volatile secondary metabolites of Lippia alba (Verbenaceae) at three stages of development].

PubMed

Parra-Garcés, María Isabel; Caroprese-Araque, José Fernando; Arrieta-Prieto, Dagoberto; Stashenko, Elena

2010-12-01

There is an increased interest to know and scientifically validate traditional knowledge of medicinal plants. Lippia alba belongs to Verbenaceae family and has been of interest, not only because of its worldwide extensive distribution, but also for its variable use as antiviral, bactericide, citostatic, analgesic and sedative. To study this, the morphology and ontogeny of Lippia alba inflorescences and the chemical composition of its volatile secondary metabolites were analyzed during three different stages of development. Plants were collected at the experimental crop field in CENIVAM, Bucaramanga, Colombia. The inflorescence's morphology and ontogeny, and the chemical composition of volatile secondary metabolites were analyzed using a stereoscopic microscope and chromatographic and spectroscopic techniques. Fresh material corresponding to each stage was fixed in F.A.A (formol, acetic acid and alcohol), included in paraffin and cutted in transversal and longitudinal sections. Sections were stained with safranine-fastgreen, photographed and decribed. The chemical composition of volatile secondary metabolites at each ontogenic stage, was extracted by solid phase micro-extraction in the headspace mode and analyzed by gas chromatography coupled to mass spectrometry. Stage I showed a meristematic mass of cells in vegetative apex and bracts, with an outline of floral whorls. In Stage III. the stamens were adnate, epipetals and didynamous, bicarpelar and syncarpic gynoecium, with superior ovary and decurrent stigma. The main secondary metabolites detected were the bicyclosesquiphellandrene followed by carvone, limonene and trans-beta-farnesene, that constituted the 78% of the total relative amounts of compounds. Other metabolites such as beta-copaene, gamma-amorphene and cis-beta-guaiene, were reported for the first time in this study. When compared to other studies, morphological differences reported in this study are possibly related to adaptation to environmental conditions or pollinators, which let us suggest that there is no specific ontogenic pattern. Similarly, the qualitative and quantitative variations in the detected compounds could be explained because one or more of them are used as precursors of others.

IMG-ABC. A knowledge base to fuel discovery of biosynthetic gene clusters and novel secondary metabolites

DOE PAGES

Hadjithomas, Michalis; Chen, I-Min Amy; Chu, Ken; ...

2015-07-14

In the discovery of secondary metabolites, analysis of sequence data is a promising exploration path that remains largely underutilized due to the lack of computational platforms that enable such a systematic approach on a large scale. In this work, we present IMG-ABC (https://img.jgi.doe.gov/abc), an atlas of biosynthetic gene clusters within the Integrated Microbial Genomes (IMG) system, which is aimed at harnessing the power of “big” genomic data for discovering small molecules. IMG-ABC relies on IMG’s comprehensive integrated structural and functional genomic data for the analysis of biosynthetic gene clusters (BCs) and associated secondary metabolites (SMs). SMs and BCs serve asmore » the two main classes of objects in IMG-ABC, each with a rich collection of attributes. A unique feature of IMG-ABC is the incorporation of both experimentally validated and computationally predicted BCs in genomes as well as metagenomes, thus identifying BCs in uncultured populations and rare taxa. We demonstrate the strength of IMG-ABC’s focused integrated analysis tools in enabling the exploration of microbial secondary metabolism on a global scale, through the discovery of phenazine-producing clusters for the first time in lphaproteobacteria. IMG-ABC strives to fill the long-existent void of resources for computational exploration of the secondary metabolism universe; its underlying scalable framework enables traversal of uncovered phylogenetic and chemical structure space, serving as a doorway to a new era in the discovery of novel molecules. IMG-ABC is the largest publicly available database of predicted and experimental biosynthetic gene clusters and the secondary metabolites they produce. The system also includes powerful search and analysis tools that are integrated with IMG’s extensive genomic/metagenomic data and analysis tool kits. As new research on biosynthetic gene clusters and secondary metabolites is published and more genomes are sequenced, IMG-ABC will continue to expand, with the goal of becoming an essential component of any bioinformatic exploration of the secondary metabolism world.« less

Secondary metabolites from marine-derived microorganisms.

PubMed

Chen, Gang; Wang, Hai-Feng; Pei, Yue-Hu

2014-01-01

In the search for novel and bioactive molecules for drug discovery, marine-derived natural resources, especially marine microorganisms are becoming an important and interesting research area. This study covers the literature published after 2008 on secondary metabolites of marine-derived microorganisms. The emphasis was on new compounds with the relevant biological activities, strain information, and country of origin. New compounds without biological activity were not included.

Fungal community, Fusarium head blight complex and secondary metabolites associated with malting barley grains harvested in Umbria, central Italy.

PubMed

Beccari, Giovanni; Senatore, Maria Teresa; Tini, Francesco; Sulyok, Michael; Covarelli, Lorenzo

2018-05-20

In recent years, due to the negative impact of toxigenic mycobiota and of the accumulation of their secondary metabolites in malting barley grains, monitoring the evolution of fungal communities in a certain cultivation area as well as detecting the different mycotoxins present in the raw material prior to malting and brewing processes have become increasingly important. In this study, a survey was carried out on malting barley samples collected after their harvest in the Umbria region (central Italy). Samples were analyzed to determine the composition of the fungal community, to identify the isolated Fusarium species, to quantify fungal secondary metabolites in the grains and to characterize the in vitro mycotoxigenic profile of a subset of the isolated Fusarium strains. The fungal community of barley grains was mainly composed of microorganisms belonging to the genus Alternaria (77%), followed by those belonging to the genus Fusarium (27%). The Fusarium head blight (FHB) complex was represented by nine species with the predominance of Fusarium poae (37%), followed by Fusarium avenaceum (23%), Fusarium graminearum (22%) and Fusarium tricinctum (7%). Secondary metabolites biosynthesized by Alternaria and Fusarium species were present in the analyzed grains. Among those biosynthesized by Fusarium species, nivalenol and enniatins were the most prevalent ones. Type A trichothecenes (T-2 and HT-2 toxins) as well as beauvericin were also present with a high incidence. Conversely, the number of samples contaminated with deoxynivalenol was low. Conjugated forms, such as deoxynivalenol-3-glucoside and HT-2-glucoside, were detected for the first time in malting barley grains cultivated in the surveyed area. In addition, strains of F. avenaceum and F. tricinctum showed the ability to biosynthesize in vitro high concentrations of enniatins. The analysis of fungal secondary metabolites, both in the grains and in vitro, revealed also the presence of other compounds, for which further investigations will be required. The combination of microbiological analyses, of molecular biology assays and of multi-mycotoxin screening shed light on the complexity of the fungal community and its secondary metabolites released in malting barley. Copyright © 2018 Elsevier B.V. All rights reserved.

Identification of signatory secondary metabolites during mycoparasitism of Rhizoctonia solani by Stachybotrys elegans

PubMed Central

Chamoun, Rony; Aliferis, Konstantinos A.; Jabaji, Suha

2015-01-01

Stachybotrys elegans is able to parasitize the fungal plant pathogen Rhizoctonia solani AG-3 following a complex and intimate interaction, which, among others, includes the production of cell wall-degrading enzymes, intracellular colonization, and expression of pathogenic process encoding genes. However, information on the metabolome level is non-existent during mycoparasitism. Here, we performed a direct-infusion mass spectrometry (DIMS) metabolomics analysis using an LTQ Orbitrap analyzer in order to detect changes in the profiles of induced secondary metabolites of both partners during this mycoparasitic interaction 4 and 5 days following its establishment. The diketopiperazine(s) (DKPs) cyclo(S-Pro-S-Leu)/cyclo(S-Pro-S-Ile), ethyl 2-phenylacetate, and 3-nitro-4-hydroxybenzoic acid were detected as the primary response of Rhizoctonia 4 days following dual-culturing with Stachybotrys, whereas only the latter metabolite was up-regulated 1 day later. On the other hand, trichothecenes and atranones were mycoparasite-derived metabolites identified during mycoparasitism 4 and 5 days following dual-culturing. All the above secondary metabolites are known to exhibit bioactivity, including fungitoxicity, and represent key elements that determine the outcome of the interaction being studied. Results could be further exploited in programs for the evaluation of the bioactivity of these metabolites per se or their chemical analogs, and/or genetic engineering programs to obtain more efficient mycoparasite strains with improved efficacy and toxicological profiles. PMID:25972848

Differential Network Analysis Reveals Evolutionary Complexity in Secondary Metabolism of Rauvolfia serpentina over Catharanthus roseus

PubMed Central

Pathania, Shivalika; Bagler, Ganesh; Ahuja, Paramvir S.

2016-01-01

Comparative co-expression analysis of multiple species using high-throughput data is an integrative approach to determine the uniformity as well as diversification in biological processes. Rauvolfia serpentina and Catharanthus roseus, both members of Apocyanacae family, are reported to have remedial properties against multiple diseases. Despite of sharing upstream of terpenoid indole alkaloid pathway, there is significant diversity in tissue-specific synthesis and accumulation of specialized metabolites in these plants. This led us to implement comparative co-expression network analysis to investigate the modules and genes responsible for differential tissue-specific expression as well as species-specific synthesis of metabolites. Toward these goals differential network analysis was implemented to identify candidate genes responsible for diversification of metabolites profile. Three genes were identified with significant difference in connectivity leading to differential regulatory behavior between these plants. These genes may be responsible for diversification of secondary metabolism, and thereby for species-specific metabolite synthesis. The network robustness of R. serpentina, determined based on topological properties, was also complemented by comparison of gene-metabolite networks of both plants, and may have evolved to have complex metabolic mechanisms as compared to C. roseus under the influence of various stimuli. This study reveals evolution of complexity in secondary metabolism of R. serpentina, and key genes that contribute toward diversification of specific metabolites. PMID:27588023

Differential Network Analysis Reveals Evolutionary Complexity in Secondary Metabolism of Rauvolfia serpentina over Catharanthus roseus.

PubMed

Pathania, Shivalika; Bagler, Ganesh; Ahuja, Paramvir S

2016-01-01

Comparative co-expression analysis of multiple species using high-throughput data is an integrative approach to determine the uniformity as well as diversification in biological processes. Rauvolfia serpentina and Catharanthus roseus, both members of Apocyanacae family, are reported to have remedial properties against multiple diseases. Despite of sharing upstream of terpenoid indole alkaloid pathway, there is significant diversity in tissue-specific synthesis and accumulation of specialized metabolites in these plants. This led us to implement comparative co-expression network analysis to investigate the modules and genes responsible for differential tissue-specific expression as well as species-specific synthesis of metabolites. Toward these goals differential network analysis was implemented to identify candidate genes responsible for diversification of metabolites profile. Three genes were identified with significant difference in connectivity leading to differential regulatory behavior between these plants. These genes may be responsible for diversification of secondary metabolism, and thereby for species-specific metabolite synthesis. The network robustness of R. serpentina, determined based on topological properties, was also complemented by comparison of gene-metabolite networks of both plants, and may have evolved to have complex metabolic mechanisms as compared to C. roseus under the influence of various stimuli. This study reveals evolution of complexity in secondary metabolism of R. serpentina, and key genes that contribute toward diversification of specific metabolites.

Insecticidal Potential of Defense Metabolites from Ocimum kilimandscharicum against Helicoverpa armigera

PubMed Central

Thulasiram, Hirekodathakallu V.; Kulkarni, Mahesh J.; Giri, Ashok P.

2014-01-01

Genus Ocimum contains a reservoir of diverse secondary metabolites, which are known for their defense and medicinal value. However, the defense-related metabolites from this genus have not been studied in depth. To gain deeper insight into inducible defense metabolites, we examined the overall biochemical and metabolic changes in Ocimum kilimandscharicum that occurred in response to the feeding of Helicoverpa armigera larvae. Metabolic analysis revealed that the primary and secondary metabolism of local and systemic tissues in O. kilimandscharicum was severely affected following larval infestation. Moreover, levels of specific secondary metabolites like camphor, limonene and β-caryophyllene (known to be involved in defense) significantly increased in leaves upon insect attack. Choice assays conducted by exposing H. armigera larvae on O. kilimandscharicum and tomato leaves, demonstrated that O. kilimandscharicum significantly deters larval feeding. Further, when larvae were fed on O. kilimandscharicum leaves, average body weight decreased and mortality of the larvae increased. Larvae fed on artificial diet supplemented with O. kilimandscharicum leaf extract, camphor, limonene and β-caryophyllene showed growth retardation, increased mortality rates and pupal deformities. Digestive enzymes of H. armigera - namely, amylase, protease and lipase- showed variable patterns after feeding on O. kilimandscharicum, which implies striving of the larvae to attain required nutrition for growth, development and metamorphosis. Evidently, selected metabolites from O. kilimandscharicum possess significant insecticidal activity. PMID:25098951

GC-MS based metabolite profiling of rice Koji fermentation by various fungi.

PubMed

Kim, Ah Jin; Choi, Jung Nam; Kim, Jiyoung; Park, Sait Byul; Yeo, Soo Hwan; Choi, Ji Ho; Lee, Choong Hwan

2010-01-01

In this study, Aspergillus kawachii, Aspergillus oryzae, and Rhizopus sp., were utilized for rice Koji fermentation, and the metabolites were analyzed in a time-dependent manner by gas chromatography-mass spectrometry. On Principal Component Analysis, the metabolite patterns were clearly distinguished based on the fungi species. This approach revealed that the quantities of glucose, galactose, and glycerol gradually increased as a function of fermentation time in all trials rice Koji fermentation. The time-dependent changes of these metabolites showed significant increases in glucose in the A. oryzae-treated rice, and in glycerol and galactose in the A. kawachii-treated rice. In addition, glycolysis-related enzyme activities were correlated with the changes in these metabolites. The results indicate that time-dependent metabolite production has the potential to be a valuable tool in selecting inoculant fungi and the optimal fermentation time for rice koji.

Thermo-stability, dose effects and shelf-life of antifungal metabolite-containing supernatants produced by Xenorhabdus szentirmai

USDA-ARS?s Scientific Manuscript database

Xenorhabdus spp. produce secondary metabolites that are antifungal to protect nematode-infected cadavers from fungal colonization. In previous work, the concentrated, or cell-free metabolites of X. szentirmaii exhibited high toxicity against various fungal plant pathogens and showed great potential ...

Spatial variability in secondary metabolites of the indo-pacific sponge Stylissa massa.

PubMed

Rohde, Sven; Gochfeld, Deborah J; Ankisetty, Sridevi; Avula, Bharathi; Schupp, Peter J; Slattery, Marc

2012-05-01

Chemical diversity represents a measure of selective pressures acting on genotypic variability. In order to understand patterns of chemical ecology and biodiversity in the environment, it is necessary to enhance our knowledge of chemical diversity within and among species. Many sponges produce variable levels of secondary metabolites in response to diverse biotic and abiotic environmental factors. This study evaluated intra-specific variability in secondary metabolites in the common Indo-Pacific sponge Stylissa massa over various geographic scales, from local to ocean basin. Several major metabolites were quantified in extracts from sponges collected in American Samoa, Pohnpei, Saipan, and at several sites and depths in Guam. Concentrations of several of these metabolites varied geographically across the Pacific basin, with American Samoa and Pohnpei exhibiting the greatest differences, and Guam and Saipan more similar to each other. There were also significant differences in concentrations among different sites and depths within Guam. The crude extract of S. massa exhibited feeding deterrence against the omnivorous pufferfish Canthigaster solandri at natural concentrations, however, none of the isolated compounds was deterrent at the maximum natural concentrations observed, nor were mixtures of these compounds, thus emphasizing the need for bioassay-guided isolation to characterize specific chemical defenses. Antibacterial activity against a panel of ecologically relevant pathogens was minimal. Depth transplants, predator exclusion, and UV protection experiments were performed, but although temporal variability in compound concentrations was observed, there was no evidence that secondary metabolite concentration in S. massa was induced by any of these factors. Although the reasons behind the variability observed in the chemical constituents of S. massa are still in question, all sponges are not created equal from a chemical standpoint, and these studies provide further insights into patterns of chemical diversity within S. massa.

UPLC-QTOF analysis reveals metabolomic changes in the flag leaf of wheat (Triticum aestivum L.) under low-nitrogen stress.

PubMed

Zhang, Yang; Ma, Xin-Ming; Wang, Xiao-Chun; Liu, Ji-Hong; Huang, Bing-Yan; Guo, Xiao-Yang; Xiong, Shu-Ping; La, Gui-Xiao

2017-02-01

Wheat is one of the most important grain crop plants worldwide. Nitrogen (N) is an essential macronutrient for the growth and development of wheat and exerts a marked influence on its metabolites. To investigate the influence of low nitrogen stress on various metabolites of the flag leaf of wheat (Triticum aestivum L.), a metabolomic analysis of two wheat cultivars under different induced nitrogen levels was conducted during two important growth periods based on large-scale untargeted metabolomic analysis using ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF). Multivariate analyses-such as principle components analysis (PCA) and orthogonal partial least square discriminant analysis (OPLS-DA)-were used for data analysis. PCA yielded distinctive clustering information among the samples, classifying the wheat flag samples into two categories: those under normal N treatment and low N treatment. By processing OPLS-DA, eleven secondary metabolites were shown to be responsible for classifying the two groups. The secondary metabolites may be considered potential biomarkers of low nitrogen stress. Chemical analyses showed that most of the identified secondary metabolites were flavonoids and their related derivatives, such as iso-vitexin, iso-orientin and methylisoorientin-2″-O-rhamnoside, etc. This study confirmed the effect of low nitrogen stress on the metabolism of wheat, and revealed that the accumulation of secondary metabolites is a response to abiotic stresses. Meanwhile, we aimed to identify markers which could be used to monitor the nitrogen status of wheat crops, presumably to guide appropriate fertilization regimens. Furthermore, the UPLC-QTOF metabolic platform technology can be used to study metabolomic variations of wheat under abiotic stresses. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

De Novo Transcriptome Assembly and Characterization of Lithospermum officinale to Discover Putative Genes Involved in Specialized Metabolites Biosynthesis.

PubMed

Rai, Amit; Nakaya, Taiki; Shimizu, Yohei; Rai, Megha; Nakamura, Michimi; Suzuki, Hideyuki; Saito, Kazuki; Yamazaki, Mami

2018-05-29

Lithospermum officinale is a valuable source of bioactive metabolites with medicinal and industrial values. However, little is known about genes involved in the biosynthesis of these metabolites, primarily due to the lack of genome or transcriptome resources. This study presents the first effort to establish and characterize de novo transcriptome assembly resource for L. officinale and expression analysis for three of its tissues, namely leaf, stem, and root. Using over 4Gbps of RNA-sequencing datasets, we obtained de novo transcriptome assembly of L. officinale , consisting of 77,047 unigenes with assembly N50 value as 1524 bps. Based on transcriptome annotation and functional classification, 52,766 unigenes were assigned with putative genes functions, gene ontology terms, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. KEGG pathway and gene ontology enrichment analysis using highly expressed unigenes across three tissues and targeted metabolome analysis showed active secondary metabolic processes enriched specifically in the root of L. officinale . Using co-expression analysis, we also identified 20 and 48 unigenes representing different enzymes of lithospermic/chlorogenic acid and shikonin biosynthesis pathways, respectively. We further identified 15 candidate unigenes annotated as cytochrome P450 with the highest expression in the root of L. officinale as novel genes with a role in key biochemical reactions toward shikonin biosynthesis. Thus, through this study, we not only generated a high-quality genomic resource for L. officinale but also propose candidate genes to be involved in shikonin biosynthesis pathways for further functional characterization. Georg Thieme Verlag KG Stuttgart · New York.

Identification and Metabolite Profiling of Chemical Activators of Lipid Accumulation in Green Algae1[OPEN

PubMed Central

2017-01-01

Microalgae are proposed as feedstock organisms useful for producing biofuels and coproducts. However, several limitations must be overcome before algae-based production is economically feasible. Among these is the ability to induce lipid accumulation and storage without affecting biomass yield. To overcome this barrier, a chemical genetics approach was employed in which 43,783 compounds were screened against Chlamydomonas reinhardtii, and 243 compounds were identified that increase triacylglyceride (TAG) accumulation without terminating growth. Identified compounds were classified by structural similarity, and 15 were selected for secondary analyses addressing impacts on growth fitness, photosynthetic pigments, and total cellular protein and starch concentrations. TAG accumulation was verified using gas chromatography-mass spectrometry quantification of total fatty acids, and targeted TAG and galactolipid measurements were performed using liquid chromatography-multiple reaction monitoring/mass spectrometry. These results demonstrated that TAG accumulation does not necessarily proceed at the expense of galactolipid. Untargeted metabolite profiling provided important insights into pathway shifts due to five different compound treatments and verified the anabolic state of the cells with regard to the oxidative pentose phosphate pathway, Calvin cycle, tricarboxylic acid cycle, and amino acid biosynthetic pathways. Metabolite patterns were distinct from nitrogen starvation and other abiotic stresses commonly used to induce oil accumulation in algae. The efficacy of these compounds also was demonstrated in three other algal species. These lipid-inducing compounds offer a valuable set of tools for delving into the biochemical mechanisms of lipid accumulation in algae and a direct means to improve algal oil content independent of the severe growth limitations associated with nutrient deprivation. PMID:28652262

Alkaloid (Meleagrine and Chrysogine) from endophytic fungi (Penicillium sp.) of Annona squamosa L.

PubMed

Yunianto, Prasetyawan; Rusman, Yudi; Saepudin, Endang; Suwarso, Wahyudi Priyono; Sumaryono, Wahono

2014-05-01

Several endophytic fungal strains from Srikaya plants (Annona squamosa L.) have been isolated and one of them was identified as Penicillium sp. Penicillium has been proven as an established source for a wide array of unique bioactive secondary metabolites that exhibit a variety of biological activities. The aim of this study is isolation of secondary metabolite from Penicillium, an endophytic of A. squamosa L. Penicillium sp. from endophytic of A. squamosa L. was fermented in Wicherham media. The whole extract from both liquid media and mycelium was partitioned by ethyl acetate and evaporated to obtain crude ethyl acetate extract. The ethyl acetate extract was then brokedown using column chromatography with silica as stationary phase and mixture of ethyl acetate/methanol (98%:2%) as mobile phase and then was separated by sephadex column. Structure elucidation of isolated compounds were mainly done by analysis of one and two dimensional NMR (Nuclear Magnetic Resonance) data and supported by HPLC (High performance Liquid Chromatography) and MS-TOF (Mass Spectrometer-Time of Flight). Isolated secondary metabolites were tested using in vitro assays for anticancer and antimicrobial activity. For anticancer activity, the metabolites were tested against breast cancer cells (MCF-7) using MTT assay, while for antimicrobial activity was performed using disk diffusion assays. From these physical, chemical and spectral evidences that the secondary metabolites were confirmed as Chrysogine and Meleagrine. Chrysogine and Meleagrine have no activity as anticancer and antimicrobial.

Patulin and secondary metabolite production by marine-derived Penicillium strains.

PubMed

Vansteelandt, Marieke; Kerzaon, Isabelle; Blanchet, Elodie; Fossi Tankoua, Olivia; Robiou Du Pont, Thibaut; Joubert, Yolaine; Monteau, Fabrice; Le Bizec, Bruno; Frisvad, Jens C; Pouchus, Yves François; Grovel, Olivier

2012-09-01

Genus Penicillium represents an important fungal group regarding to its mycotoxin production. Secondary metabolomes of eight marine-derived strains belonging to subgenera Furcatum and Penicillium were investigated using dereplication by liquid chromatography (LC)-Diode Array Detector (DAD)-mass spectrometry (MS)/MS. Each strain was grown on six different culture media to enhance the number of observable metabolites. Thirty-two secondary metabolites were detected in crude extracts with twenty first observations for studied species. Patulin, a major mycotoxin, was classically detected in extracts of Penicillium expansum, and was also isolated from Penicillium antarcticum cultures, whose secondary metabolome is still to be done. These detections constituted the first descriptions of patulin in marine strains of Penicillium, highlighting the risk for shellfish and their consumers due to the presence of these fungi in shellfish farming areas. Patulin induced acute neurotoxicity on Diptera larvae, indicating the interest of this bioassay as an additional tool for detection of this major mycotoxin in crude extracts. Copyright © 2012 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Chemical ecology of marine angiosperms: opportunities at the interface of marine and terrestrial systems.

PubMed

Sieg, R Drew; Kubanek, Julia

2013-06-01

This review examines the state of the field for chemically mediated interactions involving marine angiosperms (seagrasses, mangroves, and salt marsh angiosperms). Small-scale interactions among these plants and their herbivores, pathogens, fouling organisms, and competitors are explored, as are community-level effects of plant secondary metabolites. At larger spatial scales, secondary metabolites from marine angiosperms function as reliable cues for larval settlement, molting, or habitat selection by fish and invertebrates, and can influence community structure and ecosystem function. Several recent studies illustrate the importance of chemical defenses from these plants that deter feeding by herbivores and infection by pathogens, but the extent to which allelopathic compounds kill or inhibit the growth of competitors is less clear. While some phenolic compounds such as ferulic acid and caffeic acid act as critical defenses against herbivores and pathogens, we find that a high total concentration of phenolic compounds within bulk plant tissues is not a strong predictor of defense. Residual chemical defenses prevent shredding or degradation of plant detritus by detritivores and microbes, delaying the time before plant matter can enter the microbial loop. Mangroves, marsh plants, and seagrasses remain plentiful sources of new natural products, but ecological functions are known for only a small proportion of these compounds. As new analytical techniques are incorporated into ecological studies, opportunities are emerging for chemical ecologists to test how subtle environmental cues affect the production and release of marine angiosperm chemical defenses or signaling molecules. Throughout this review, we point to areas for future study, highlighting opportunities for new directions in chemical ecology that will advance our understanding of ecological interactions in these valuable ecosystems.

Quantification of 4'-geranyloxyferulic acid, a new natural colon cancer chemopreventive agent, by HPLC-DAD in grapefruit skin extract.

PubMed

Genovese, S; Epifano, F; Carlucci, G; Marcotullio, M C; Curini, M; Locatelli, M

2010-10-10

Oxyprenylated natural products (isopentenyloxy-, geranyloxy- and the less spread farnesyloxy-compounds and their biosynthetic derivatives) represent a family of secondary metabolites that have been consider for years merely as biosynthetic intermediates of the most abundant C-prenylated derivatives. Many of the isolated oxyprenylated natural products were shown to exert in vitro and in vivo remarkable anti-cancer and anti-inflammatory effects. 4'-Geranyloxyferulic acid [3-(4'-geranyloxy-3'-methoxyphenyl)-2-trans-propenoic] has been discovered as a valuable chemopreventive agent of several types of cancer. After development of a high yield and "eco-friendly" synthetic scheme of this secondary metabolite, starting from cheap and non-toxic reagents and substrates, we developed a new HPLC-DAD method for its quantification in grapefruit skin extract. A preliminary study on C18 column showed the separation between GOFA and boropinic acid (having the same core but with an isopentenyloxy side chain), used as internal standard. The tested column were thermostated at 28+/-1 degrees C and the separation was achieved in gradient condition at a flow rate of 1 mL/min with a starting mobile phase of H(2)O:methanol (40:60, v/v, 1% formic acid). The limit of detection (LOD, S/N=3) was 0.5 microg/mL and the limit of quantification (LOQ, S/N=10) was 1 microg/mL. Matrix-matched standard curves showed linearity up to 75 microg/mL. In the analytical range the precision (RSD%) values were

The influence of L-phenylalanine, methyl jasmonate and sucrose concentration on the accumulation of phenolic acids in Exacum affine Balf. f. ex Regel shoot culture.

PubMed

Skrzypczak-Pietraszek, Ewa; Słota, Joanna; Pietraszek, Jacek

2014-01-01

Phenolic acids are an important group of plant secondary metabolites with various, valuable therapeutic properties. Apart from plants growing in the open air, tissue cultures can be an alternative source of the secondary metabolites. The yield of their accumulation in in vitro cultures can be increased by different methods, including culture medium supplementation with precursors, elicitors and changing the standard amounts of the medium components. The purpose of this study was to investigate the influence of the precursor (L-phenylalanine), the elicitor (methyl jasmonate) and a higher sucrose concentration on the phenolic acids accumulation in the agitated shoot cultures of Exacum affine Balf. f. ex Regel (Gentianaceae). Qualitative and quantitative analyses of the phenolic acids in methanolic extracts from the biomass were conducted by applying the HPLC method. Fourteen phenolic acids and cinnamic acid were found in all samples. The total content of free phenolic acids increased from approximately 0.242% to 0.635% (2.6-fold) and the total content of the whole phenolic acids (free and bound) - from 0.712% to 1.160% (1.6-fold). The studies show that the best variant for the accumulation of most of the identified phenolic acids contained 6% of sucrose (double the standard amount), L-phenylalanine 1.6 gL(-1) of medium and methyl jasmonate 100 μM. The analysis of the results in the experiment presented here showed that it is possible to increase the accumulation of the phenolic acids in Exacum affine shoot cultures - by adding the precursor (L-phenylalanine), the elicitor (methyl jasmonate) and by increasing the sucrose concentration.

Media and growth conditions for induction of secondary metabolite production.

PubMed

Frisvad, Jens C

2012-01-01

Growth media and incubation conditions have a very strong influence of secondary metabolite production. There is no consensus on which media are the optimal for metabolite production, but a series of useful and effective media and incubation conditions have been listed here. Chemically well-defined media are suited for biochemical studies, but in order to get chemical diversity expressed in filamentous fungi, sources rich in amino acids, vitamins, and trace metals have to be added, such as yeast extract and oatmeal. A battery of solid agar media is recommended for exploration of chemical diversity as agar plug samples are easily analyzed to get an optimal representation of the qualitative secondary metabolome. Standard incubation for a week at 25°C in darkness is recommended, but optimal conditions have to be modified depending on the ecology and physiology of different filamentous fungi.

Comparison of two DNA extraction protocols from leave samples of Cotinus coggygria, Citrus sinensis and Genus juglans.

PubMed

Fallah, F; Minaei Chenar, H; Amiri, H; Omodipour, S; Shirbande Ghods, F; Kahrizi, D; Sohrabi, M; Ghorbani, T; Kazemi, E

2017-02-28

High quality DNA is essential for molecular research. Secondary metabolites can affect the quantity and quality DNA. In current research two DNA isolation methods including CTAB and Delaporta (protocols 1 & 2 respectively) were applied in three leave samples from Cotinus coggygria, Citrus sinensis and Genus juglans that their leaves are rich of secondary metabolites. We successfully isolated DNA from C. coggygria, C. sinensis and Genus Juglans using the two protocols described above. Good quality DNA was isolated from C. coggygria, C. sinensis and Genus Juglans using protocol 1, while protocol 2 failed to produce usable DNA from these sources. The highest amount of DNA (1.3-1.6) was obtained from them using protocol 1. As we discovered, procedure 1 may work better for plants with secondary metabolites.

Involvement of secondary metabolites in the pathogenesis of the American foulbrood of honey bees caused by Paenibacillus larvae.

PubMed

Müller, Sebastian; Garcia-Gonzalez, Eva; Genersch, Elke; Süssmuth, Roderich D

2015-06-01

The Gram-positive, spore-forming bacterium Paenibacillus larvae (P. larvae) is the causative agent of the epizootic American Foulbrood (AFB), a fatal brood disease of the western honey bee (Apis mellifera). AFB is one of the most destructive honey bee diseases since it is not only lethal for infected larvae but also for the diseased colonies. Due to the high impact of honey bees on ecology and economy this epizootic is a severe and pressing problem. Knowledge about virulence mechanisms and the underlying molecular mechanisms remain largely elusive. Recent genome sequencing of P. larvae revealed its potential to produce unknown secondary metabolites, like nonribosomal peptides and peptide-polyketide hybrids. This article highlights recent findings on secondary metabolites synthesized by P. larvae and discusses their role in virulence and pathogenicity towards the bee larvae.

Bioactive alkaloids produced by fungi. I. Updates on alkaloids from the species of the genera Boletus, Fusarium and psilocybe.

PubMed

Mahmood, Zafar Alam; Ahmed, Syed Waseemuddin; Azhar, Iqbal; Sualeh, Mohammad; Baig, Mirza Tasawer; Zoha, Sms

2010-07-01

Fungi, in particular, are able in common with the higher plants and bacteria, to produce metabolites, including alkaloids. Alkaloids, along with other metabolites are the most important fungal metabolites from pharmaceutical and industrial point of view. Based on this observation, the authors of this review article have tried to provide an information on the alkaloids produced by the species of genera: Boletus, Fusarium and Psilocybef from 1981-2009. Thus the review would be helpful and provides valuable information for the researchers of the same field.

Qualitative and quantitative mass spectrometry imaging of drugs and metabolites in tissue at therapeutic levels.

PubMed

Sun, Na; Walch, Axel

2013-08-01

Mass spectrometry imaging (MSI) is a rapidly evolving technology that yields qualitative and quantitative distribution maps of small pharmaceutical-active molecules and their metabolites in tissue sections in situ. The simplicity, high sensitivity and ability to provide comprehensive spatial distribution maps of different classes of biomolecules make MSI a valuable tool to complement histopathology for diagnostics and biomarker discovery. In this review, qualitative and quantitative MSI of drugs and metabolites in tissue at therapeutic levels are discussed and the impact of this technique in drug discovery and clinical research is highlighted.

Illuminating a plant’s tissue-specific metabolic diversity using computational metabolomics and information theory

PubMed Central

Li, Dapeng; Heiling, Sven; Baldwin, Ian T.

2016-01-01

Secondary metabolite diversity is considered an important fitness determinant for plants’ biotic and abiotic interactions in nature. This diversity can be examined in two dimensions. The first one considers metabolite diversity across plant species. A second way of looking at this diversity is by considering the tissue-specific localization of pathways underlying secondary metabolism within a plant. Although these cross-tissue metabolite variations are increasingly regarded as important readouts of tissue-level gene function and regulatory processes, they have rarely been comprehensively explored by nontargeted metabolomics. As such, important questions have remained superficially addressed. For instance, which tissues exhibit prevalent signatures of metabolic specialization? Reciprocally, which metabolites contribute most to this tissue specialization in contrast to those metabolites exhibiting housekeeping characteristics? Here, we explore tissue-level metabolic specialization in Nicotiana attenuata, an ecological model with rich secondary metabolism, by combining tissue-wide nontargeted mass spectral data acquisition, information theory analysis, and tandem MS (MS/MS) molecular networks. This analysis was conducted for two different methanolic extracts of 14 tissues and deconvoluted 895 nonredundant MS/MS spectra. Using information theory analysis, anthers were found to harbor the most specialized metabolome, and most unique metabolites of anthers and other tissues were annotated through MS/MS molecular networks. Tissue–metabolite association maps were used to predict tissue-specific gene functions. Predictions for the function of two UDP-glycosyltransferases in flavonoid metabolism were confirmed by virus-induced gene silencing. The present workflow allows biologists to amortize the vast amount of data produced by modern MS instrumentation in their quest to understand gene function. PMID:27821729

The influence of arbuscular mycorrhizal fungi inoculation on yam (Dioscorea spp.) tuber weights and secondary metabolite content.

PubMed

Lu, Fun-Chi; Lee, Chen-Yu; Wang, Chun-Li

2015-01-01

Arbuscular mycorrhizal fungi (AMF) are widely distributed in nature. They live in the roots of higher plants, in a symbiotic relationship. In this study, five commercial species of yams (Dioscorea spp.) were inoculated with six species of AMF, Glomus clarum, G. etunicatum, G. fasciculatum, Gigaspora sp., G. mosseae, and Acaulospora sp., in field cultivation conditions to investigate the influence of AMF inoculation on tuber weights and secondary metabolite content in yam tubers. The results showed that mycorrhizae formation rates ranged from 63.33% to 90%. G. etunicatum inoculation treatment increased the tube weights of the five species of yam tubers by 39%, 35%, 20%, 56%, and 40% for Tainung 1, Tainung 2, Ercih, Zihyuxieshu, and Tainung 5, respectively. The content of secondary metabolites, such as polyphenols, flavonoids, and anthocyanin, was significantly increased by the AMF treatment in tuber flesh and peel of all the tested yam species. Specifically, the maximums exchange of secondary metabolite contents increased to 40%, 42%, and 106% for polyphenols, flavonoids, and anthocyanin, respectively, in the tuber fresh. This study revealed that different species of yam had varying degrees of affinity with various AMF species; selecting effective AMF species is necessary to facilitate yam growth and improve the quality and quantity of yam tubers.

Lysobacter enzymogenes uses two distinct cell-cell signaling systems for differential regulation of secondary-metabolite biosynthesis and colony morphology.

PubMed

Qian, Guoliang; Wang, Yulan; Liu, Yiru; Xu, Feifei; He, Ya-Wen; Du, Liangcheng; Venturi, Vittorio; Fan, Jiaqin; Hu, Baishi; Liu, Fengquan

2013-11-01

Lysobacter enzymogenes is a ubiquitous environmental bacterium that is emerging as a potentially novel biological control agent and a new source of bioactive secondary metabolites, such as the heat-stable antifungal factor (HSAF) and photoprotective polyene pigments. Thus far, the regulatory mechanism(s) for biosynthesis of these bioactive secondary metabolites remains largely unknown in L. enzymogenes. In the present study, the diffusible signal factor (DSF) and diffusible factor (DF)-mediated cell-cell signaling systems were identified for the first time from L. enzymogenes. The results show that both Rpf/DSF and DF signaling systems played critical roles in modulating HSAF biosynthesis in L. enzymogenes. Rpf/DSF signaling and DF signaling played negative and positive effects in polyene pigment production, respectively, with DF playing a more important role in regulating this phenotype. Interestingly, only Rpf/DSF, but not the DF signaling system, regulated colony morphology of L. enzymgenes. Both Rpf/DSF and DF signaling systems were involved in the modulation of expression of genes with diverse functions in L. enzymogenes, and their own regulons exhibited only a few loci that were regulated by both systems. These findings unveil for the first time new roles of the Rpf/DSF and DF signaling systems in secondary metabolite biosynthesis of L. enzymogenes.

Impact of organic and inorganic fertilizers application on the phytochemical and antioxidant activity of Kacip Fatimah (Labisia pumila Benth).

PubMed

Ibrahim, Mohd Hafiz; Jaafar, Hawa Z E; Karimi, Ehsan; Ghasemzadeh, Ali

2013-09-05

A study was conducted to compare secondary metabolites and antioxidant activity of Labisia pumila Benth (Kacip Fatimah) in response to two sources of fertilizer [i.e., organic (chicken dung; 10% N:10% P₂O₅:10% K₂O) and inorganic fertilizer (NPK green; 15% N, 15% P₂O₅, 15% K₂O)] under different N rates of 0, 90, 180 and 270 kg N/ha. The experiment was arranged in a randomized complete block design replicated three times. At the end of 15 weeks, it was observed that the application of organic fertilizer enhanced the production of total phenolics, flavonoids, ascorbic acid, saponin and gluthathione content in L. pumila, compared to the use of inorganic fertilizer. The nitrate content was also reduced under organic fertilization. The application of nitrogen at 90 kg N/ha improved the production of secondary metabolites in Labisia pumila. Higher rates in excess of 90 kg N/ha reduced the level of secondary metabolites and antioxidant activity of this herb. The DPPH and FRAP activity was also highest at 90 kg N/ha. The results indicated that the use of chicken dung can enhance the production of secondary metabolites and improve antioxidant activity of this herb.

Taxonomic Characterization and Secondary Metabolite Profiling of Aspergillus Section Aspergillus Contaminating Feeds and Feedstuffs

PubMed Central

Greco, Mariana; Kemppainen, Minna; Pose, Graciela; Pardo, Alejandro

2015-01-01

Xerophilic fungal species of the genus Aspergillus are economically highly relevant due to their ability to grow on low water activity substrates causing spoilage of stored goods and animal feeds. These fungi can synthesize a variety of secondary metabolites, many of which show animal toxicity, creating a health risk for food production animals and to humans as final consumers, respectively. Animal feeds used for rabbit, chinchilla and rainbow trout production in Argentina were analysed for the presence of xerophilic Aspergillus section Aspergillus species. High isolation frequencies (>60%) were detected in all the studied rabbit and chinchilla feeds, while the rainbow trout feeds showed lower fungal charge (25%). These section Aspergillus contaminations comprised predominantly five taxa. Twenty isolates were subjected to taxonomic characterization using both ascospore SEM micromorphology and two independent DNA loci sequencing. The secondary metabolite profiles of the isolates were determined qualitatively by HPLC-MS. All the isolates produced neoechinulin A, 17 isolates were positive for cladosporin and echinulin, and 18 were positive for neoechinulin B. Physcion and preechinulin were detected in a minor proportion of the isolates. This is the first report describing the detailed species composition and the secondary metabolite profiles of Aspergillus section Aspergillus contaminating animal feeds. PMID:26364643

Antifungal activity of secondary plant metabolites from potatoes (Solanum tuberosum L.): Glycoalkaloids and phenolic acids show synergistic effects.

PubMed

Sánchez-Maldonado, A F; Schieber, A; Gänzle, M G

2016-04-01

To study the antifungal effects of the potato secondary metabolites α-solanine, α-chaconine, solanidine and caffeic acid, alone or combined. Resistance to glycoalkaloids varied among the fungal species tested, as derived from minimum inhibitory concentrations assays. Synergistic antifungal activity between glycoalkaloids and phenolic compounds was found. Changes in the fluidity of fungal membranes caused by potato secondary plant metabolites were determined by calculation of the generalized polarization values. The results partially explained the synergistic effect between caffeic acid and α-chaconine and supported findings on membrane disruption mechanisms from previous studies on artificial membranes. LC/MS analysis was used to determine variability and relative amounts of sterols in the different fungal species. Results suggested that the sterol pattern of fungi is related to their resistance to potato glycoalkaloids and to their taxonomy. Fungal resistance to α-chaconine and possibly other glycoalkaloids is species dependent. α-Chaconine and caffeic acid show synergistic antifungal activity. The taxonomic classification and the sterol pattern play a role in fungal resistance to glycoalkaloids. Results improve the understanding of the antifungal mode of action of potato secondary metabolites, which is essential for their potential utilization as antifungal agents in nonfood systems. © 2016 The Society for Applied Microbiology.

Supplementing Blends of Sugars, Amino Acids, and Secondary Metabolites to the Diet of Termites (Reticulitermes flavipes) Drive Distinct Gut Bacterial Communities.

PubMed

Huang, Xing-Feng; Chaparro, Jacqueline M; Reardon, Kenneth F; Judd, Timothy M; Vivanco, Jorge M

2016-10-01

Although it is well known that diet is one of the major modulators of the gut microbiome, how the major components of diet shape the gut microbial community is not well understood. Here, we developed a simple system that allows the investigation of the impact of given compounds as supplements of the diet on the termite gut microbiome. The 16S rRNA pyrosequencing analysis revealed that feeding termites different blends of sugars and amino acids did not majorly impact gut community composition; however, ingestion of blends of secondary metabolites caused shifts in gut bacterial community composition. The supplementation of sugars and amino acids reduced the richness significantly, and sugars alone increased the evenness of the gut bacterial community significantly. Secondary metabolites created the most dramatic effects on the microbial community, potentially overriding the effect of other types of compounds. Furthermore, some microbial groups were stimulated specifically by particular groups of compounds. For instance, termites fed with secondary metabolites contained more Firmicutes and Spirochaetes compared to the other treatments. In conclusion, our results suggest that the termite (Reticulitermes flavipes) can be used as a simple and effective system to test the effects of particular chemical compounds in modulating the gut microbiome.

Lysobacter enzymogenes Uses Two Distinct Cell-Cell Signaling Systems for Differential Regulation of Secondary-Metabolite Biosynthesis and Colony Morphology

PubMed Central

Qian, Guoliang; Wang, Yulan; Liu, Yiru; Xu, Feifei; He, Ya-Wen; Du, Liangcheng; Venturi, Vittorio; Fan, Jiaqin; Hu, Baishi

2013-01-01

Lysobacter enzymogenes is a ubiquitous environmental bacterium that is emerging as a potentially novel biological control agent and a new source of bioactive secondary metabolites, such as the heat-stable antifungal factor (HSAF) and photoprotective polyene pigments. Thus far, the regulatory mechanism(s) for biosynthesis of these bioactive secondary metabolites remains largely unknown in L. enzymogenes. In the present study, the diffusible signal factor (DSF) and diffusible factor (DF)-mediated cell-cell signaling systems were identified for the first time from L. enzymogenes. The results show that both Rpf/DSF and DF signaling systems played critical roles in modulating HSAF biosynthesis in L. enzymogenes. Rpf/DSF signaling and DF signaling played negative and positive effects in polyene pigment production, respectively, with DF playing a more important role in regulating this phenotype. Interestingly, only Rpf/DSF, but not the DF signaling system, regulated colony morphology of L. enzymgenes. Both Rpf/DSF and DF signaling systems were involved in the modulation of expression of genes with diverse functions in L. enzymogenes, and their own regulons exhibited only a few loci that were regulated by both systems. These findings unveil for the first time new roles of the Rpf/DSF and DF signaling systems in secondary metabolite biosynthesis of L. enzymogenes. PMID:23974132

Effects of ecological factors on secondary metabolites and inorganic elements of Scutellaria baicalensis and analysis of geoherblism.

PubMed

Guo, Lanping; Wang, Sheng; Zhang, Ji; Yang, Guang; Zhao, Manxi; Ma, Weifeng; Zhang, Xiaobo; Li, Xuan; Han, Bangxing; Chen, Naifu; Huang, Luqi

2013-11-01

This study analyzed the effects of ecological factors on secondary metabolites of Scutellaria baicalensis using two sources: 92 individual roots of S. baicalensis from all over China, and secondary metabolites, medicinal materials and inorganic element contents obtained from the testing of 92 S. baicalensis rhizosphere soil samples. The study used environmental data from the Genuine Medicinal Material Spatial Analysis Database. Most of the chemical constituents of S. baicalensis were negatively correlated to latitude and positively correlated to temperature; generally, the contents of 21 chemical constituents were higher at low latitudes than that at high latitudes. By gradual regression analysis, it was found that the content of baicalin in S. baicalensis was negatively correlated to latitude and generally the content of inorganic elements in soil was excessively high (excluding Mg and Ca), which has a negative effect on the accumulation of chemical constituents in S. baicalensis. Based on the cluster analysis of 21 constituents, S. baicalensis from different places of origin was divided into two groups, and S. baicalensis was not genuine only in a specific small region. Within the zone from Chifeng, Inner Mongolia to Taibai, Shaanxi is suitable for accumulation of secondary metabolites of S. baicalensis and such a zone represents a suitable distribution and potential genuine producing area.

Non-targeted metabolite profiling highlights the potential of strawberry leaves as a resource for specific bioactive compounds.

PubMed

Kårlund, Anna; Hanhineva, Kati; Lehtonen, Marko; McDougall, Gordon J; Stewart, Derek; Karjalainen, Reijo O

2017-05-01

The non-edible parts of horticultural crops, such as leaves, contain substantial amounts of valuable bioactive compounds which are currently only little exploited. For example, strawberry (Fragaria × ananassa) leaves may be a promising bioresource for diverse health-related applications. However, product standardization sets a real challenge, especially when the leaf material comes from varying cultivars. The first step towards better quality control of berry fruit leaf-based ingredients and supplements is to understand metabolites present and their stability in different plant cultivars, so this study surveyed the distribution of potentially bioactive strawberry leaf metabolites in six different strawberry cultivars. Non-targeted metabolite profiling analysis using LC/qTOF-ESI-MS with data processing via principal component analysis and k-means clustering analysis was utilized to examine differences and commonalities between the leaf metabolite profiles. Quercetin and kaempferol derivatives were the dominant flavonol groups in strawberry leaves. Previously described and novel caffeic and chlorogenic acid derivatives were among the major phenolic acids. In addition, ellagitannins were one of the distinguishing compound classes in strawberry leaves. In general, strawberry leaves also contained high levels of octadecatrienoic acid derivatives, precursors of valuable odour compounds. The specific bioactive compounds found in the leaves of different strawberry cultivars offer the potential for the selection of optimized leaf materials for added-value food and non-food applications. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

[Influence of diethyl sulfate (DES) mutagenesis on growth properties and pigment secondary metabolites of Phellinus igniarius].

PubMed

Wang, Jing; Wu, Xin-yuan; Ma, Wei; Chen, Jing; Liu, Cheng; Wu, Xiu-li

2015-06-01

The diethyl sulfate (DES) mutagenesis was chosen for the mutagenic treatment to Phellinus igniarius, and the relationship of mutagenesis time and death rate was investigated with 0.5% DES. The differences of mycelial growth speed, liquid fermentation mycelia biomass, morphology and pigment classes of secondary metabolites production speed and antioxidant activities of metabolite products were discussed. The study displayed that DES mutagenesis could change mycelial morphology without obvious effect on mycelium growth, and the DES mutagenesis improved antioxidant activities of the active ingredients of P. igniarius and had more antioxidant activity of hypoxia/sugar PC12 nerve cells than that of P. igniarius.

Analysis of Particulate and Dissolved Metabolite Pools at Station ALOHA

NASA Astrophysics Data System (ADS)

Boysen, A.; Carlson, L.; Hmelo, L.; Ingalls, A. E.

2016-02-01

Metabolomic studies focus on identifying and quantifying the small organic molecules that are the currency by which an organism lives and dies. Metabolite profiles of microorganisms have the potential to elucidate mechanisms of chemically mediated interactions that influence the success of microbial groups living in a complex environment. However, the chemical diversity of metabolites makes resolving a wide range of compounds analytically challenging. As such, metabolomics has lagged behind other genomic analyses. Here we conduct targeted analysis of over 200 primary and secondary metabolites present in the intracellular and extracellular metabolite pools at Station ALOHA using both reverse phase and hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry. We selected the metabolites in our method due to their known importance in primary metabolism, secondary metabolism, and interactions between marine microorganisms such as nutrient exchange, growth promotion, and cell signaling. Through these analyses we obtain a snapshot of microbial community status that, blended with other forms of genomic data, can further our understanding of microbial dynamics. We hypothesize that monitoring a large suite of important metabolites across environmental gradients and diurnal cycles can elucidate factors controlling the distribution and activity of important microbial groups.

Clustering of 3D-Structure Similarity Based Network of Secondary Metabolites Reveals Their Relationships with Biological Activities.

PubMed

Ohtana, Yuki; Abdullah, Azian Azamimi; Altaf-Ul-Amin, Md; Huang, Ming; Ono, Naoaki; Sato, Tetsuo; Sugiura, Tadao; Horai, Hisayuki; Nakamura, Yukiko; Morita Hirai, Aki; Lange, Klaus W; Kibinge, Nelson K; Katsuragi, Tetsuo; Shirai, Tsuyoshi; Kanaya, Shigehiko

2014-12-01

Developing database systems connecting diverse species based on omics is the most important theme in big data biology. To attain this purpose, we have developed KNApSAcK Family Databases, which are utilized in a number of researches in metabolomics. In the present study, we have developed a network-based approach to analyze relationships between 3D structure and biological activity of metabolites consisting of four steps as follows: construction of a network of metabolites based on structural similarity (Step 1), classification of metabolites into structure groups (Step 2), assessment of statistically significant relations between structure groups and biological activities (Step 3), and 2-dimensional clustering of the constructed data matrix based on statistically significant relations between structure groups and biological activities (Step 4). Applying this method to a data set consisting of 2072 secondary metabolites and 140 biological activities reported in KNApSAcK Metabolite Activity DB, we obtained 983 statistically significant structure group-biological activity pairs. As a whole, we systematically analyzed the relationship between 3D-chemical structures of metabolites and biological activities. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Protection by fungal starters against growth and secondary metabolite production of fungal spoilers of cheese.

PubMed

Nielsen, M S; Frisvad, J C; Nielsen, P V

1998-06-30

The influence of fungal starter cultures on growth and secondary metabolite production of fungal contaminants associated with cheese was studied on laboratory media and Camembert cheese. Isolates of the species Penicillium nalgiovense, P. camemberti, P. roqueforti and Geotrichum candidum were used as fungal starters. The species P. commune, P. caseifulvum, P. verrucosum, P. discolor, P. solitum, P. coprophilum and Aspergillus versicolor were selected as contaminants. The fungal starters showed different competitive ability on laboratory media and Camembert cheese. The presence of the Penicillium species, especially P. nalgiovense, showed an inhibitory effect on the growth of the fungal contaminants on laboratory media. G. candidum caused a significant inhibition of the fungal contaminants on Camembert cheese. The results indicate that G. candidum plays an important role in competition with undesirable microorganisms in mould fermented cheeses. Among the starters, P. nalgiovense caused the largest reduction in secondary metabolite production of the fungal contaminants on the laboratory medium. On Camembert cheese no significant changes in metabolite production of the fungal contaminants was observed in the presence of the starters.

Biotechnological and industrial significance of cyanobacterial secondary metabolites.

PubMed

Rastogi, Rajesh P; Sinha, Rajeshwar P

2009-01-01

Cyanobacteria are considered to be a rich source of novel metabolites of a great importance from a biotechnological and industrial point of view. Some cyanobacterial secondary metabolites (CSMs), exhibit toxic effects on living organisms. A diverse range of these cyanotoxins may have ecological roles as allelochemicals, and could be employed for the commercial development of compounds with applications such as algaecides, herbicides and insecticides. Recently, cyanobacteria have become an attractive source of innovative classes of pharmacologically active compounds showing interesting and exciting biological activities ranging from antibiotics, immunosuppressant, and anticancer, antiviral, antiinflammatory to proteinase-inhibiting agents. A different but not less interesting property of these microorganisms is their capacity of overcoming the toxicity of ultraviolet radiation (UVR) by means of UV-absorbing/screening compounds, such as mycosporine-like amino acids (MAAs) and scytonemin. These last two compounds are true 'multipurpose' secondary metabolites and considered to be natural photoprotectants. In this sense, they may be biotechnologically exploited by the cosmetic industry. Overall CSMs are striking targets in biotechnology and biomedical research, because of their potential applications in agriculture, industry, and especially in pharmaceuticals.

Carbon catabolite regulation in Streptomyces: new insights and lessons learned.

PubMed

Romero-Rodríguez, Alba; Rocha, Diana; Ruiz-Villafán, Beatriz; Guzmán-Trampe, Silvia; Maldonado-Carmona, Nidia; Vázquez-Hernández, Melissa; Zelarayán, Augusto; Rodríguez-Sanoja, Romina; Sánchez, Sergio

2017-09-01

One of the most significant control mechanisms of the physiological processes in the genus Streptomyces is carbon catabolite repression (CCR). This mechanism controls the expression of genes involved in the uptake and utilization of alternative carbon sources in Streptomyces and is mostly independent of the phosphoenolpyruvate phosphotransferase system (PTS). CCR also affects morphological differentiation and the synthesis of secondary metabolites, although not all secondary metabolite genes are equally sensitive to the control by the carbon source. Even when the outcome effect of CCR in bacteria is the same, their essential mechanisms can be rather different. Although usually, glucose elicits this phenomenon, other rapidly metabolized carbon sources can also cause CCR. Multiple efforts have been put through to the understanding of the mechanism of CCR in this genus. However, a reasonable mechanism to explain the nature of this process in Streptomyces does not yet exist. Several examples of primary and secondary metabolites subject to CCR will be examined in this review. Additionally, recent advances in the metabolites and protein factors involved in the Streptomyces CCR, as well as their mechanisms will be described and discussed in this review.

Untargeted metabolomic profiling plasma samples of patients with lung cancer for searching significant metabolites by HPLC-MS method

NASA Astrophysics Data System (ADS)

Dementeva, N.; Ivanova, K.; Kokova, D.; Kurzina, I.; Ponomaryova, A.; Kzhyshkowska, J.

2017-09-01

Lung cancer is one of the most common types of cancer leading to death. Consequently, the search and the identification of the metabolites associated with the risk of developing cancer are very valuable. For the purpose, untargeted metabolic profiling of the plasma samples collected from the patients with lung cancer (n = 100) and the control group (n = 100) was conducted. After sample preparation, the plasma samples were analyzed using LC-MS method. Biostatistics methods were applied to pre-process the data for elicitation of dominating metabolites which responded to the difference between the case and the control groups. At least seven significant metabolites were evaluated and annotated. The most part of identified metabolites are connected with lipid metabolism and their combination could be useful for follow-up studies of lung cancer pathogenesis.

Integrated analysis of rice transcriptomic and metabolomic responses to elevated night temperatures identifies sensitivity- and tolerance-related profiles.

PubMed

Glaubitz, Ulrike; Li, Xia; Schaedel, Sandra; Erban, Alexander; Sulpice, Ronan; Kopka, Joachim; Hincha, Dirk K; Zuther, Ellen

2017-01-01

Transcript and metabolite profiling were performed on leaves from six rice cultivars under high night temperature (HNT) condition. Six genes were identified as central for HNT response encoding proteins involved in transcription regulation, signal transduction, protein-protein interactions, jasmonate response and the biosynthesis of secondary metabolites. Sensitive cultivars showed specific changes in transcript abundance including abiotic stress responses, changes of cell wall-related genes, of ABA signaling and secondary metabolism. Additionally, metabolite profiles revealed a highly activated TCA cycle under HNT and concomitantly increased levels in pathways branching off that could be corroborated by enzyme activity measurements. Integrated data analysis using clustering based on one-dimensional self-organizing maps identified two profiles highly correlated with HNT sensitivity. The sensitivity profile included genes of the functional bins abiotic stress, hormone metabolism, cell wall, signaling, redox state, transcription factors, secondary metabolites and defence genes. In the tolerance profile, similar bins were affected with slight differences in hormone metabolism and transcription factor responses. Metabolites of the two profiles revealed involvement of GABA signaling, thus providing a link to the TCA cycle status in sensitive cultivars and of myo-inositol as precursor for inositol phosphates linking jasmonate signaling to the HNT response specifically in tolerant cultivars. © 2016 John Wiley & Sons Ltd.

Secondary metabolites from three Florida sponges with antidepressant activity.

PubMed

Kochanowska, Anna J; Rao, Karumanchi V; Childress, Suzanne; El-Alfy, Abir; Matsumoto, Rae R; Kelly, Michelle; Stewart, Gina S; Sufka, Kenneth J; Hamann, Mark T

2008-02-01

Brominated indole alkaloids are a common class of metabolites reported from sponges of the order Verongida. Herein we report the isolation, structure determination, and activity of metabolites from three Florida sponges, namely, Verongula rigida (order Verongida, family Aplysinidae), Smenospongia aurea, and S. cerebriformis (order Dictyoceratida, family Thorectidae). All three species were investigated chemically, revealing similarities in secondary metabolites. Brominated compounds, as well as sesquiterpene quinones and hydroquinones, were identified from both V. rigida and S. aurea despite their apparent taxonomic differences at the ordinal level. Similar metabolites found in these distinct sponge species of two different genera provide evidence for a microbial origin of the metabolites. Isolated compounds were evaluated in the Porsolt forced swim test (FST) and the chick anxiety-depression continuum model. Among the isolated compounds, 5,6-dibromo- N,N-dimethyltryptamine ( 1) exhibited significant antidepressant-like action in the rodent FST model, while 5-bromo- N,N-dimethyltryptamine ( 2) caused significant reduction of locomotor activity indicative of a potential sedative action. The current study provides ample evidence that marine natural products with the diversity of brominated marine alkaloids will provide potential leads for antidepressant and anxiolytic drugs.

Laboratory course on Streptomyces genetics and secondary metabolism.

PubMed

Siitonen, Vilja; Räty, Kaj; Metsä-Ketelä, Mikko

2016-09-10

The "Streptomyces genetics and secondary metabolism" laboratory course gives an introduction to the versatile soil dwelling Gram-positive bacteria Streptomyces and their secondary metabolism. The course combines genetic modification of Streptomyces; growing of the strain and protoplast preparation, plasmid isolation by alkaline lysis and phenol precipitation, digestions, and ligations prior to protoplast transformation, as well as investigating the secondary metabolites produced by the strains. Thus, the course is a combination of microbiology, molecular biology, and chemistry. After the course the students should understand the relationship between genes, proteins, and the produced metabolites. © 2016 by The International Union of Biochemistry and Molecular Biology, 44(5):492-499, 2016. © 2016 The International Union of Biochemistry and Molecular Biology.

Biological and therapeutic properties of bee pollen: a review.

PubMed

Denisow, Bożena; Denisow-Pietrzyk, Marta

2016-10-01

Natural products, including bee products, are particularly appreciated by consumers and are used for therapeutic purposes as alternative drugs. However, it is not known whether treatments with bee products are safe and how to minimise the health risks of such products. Among others, bee pollen is a natural honeybee product promoted as a valuable source of nourishing substances and energy. The health-enhancing value of bee pollen is expected due to the wide range of secondary plant metabolites (tocopherol, niacin, thiamine, biotin and folic acid, polyphenols, carotenoid pigments, phytosterols), besides enzymes and co-enzymes, contained in bee pollen. The promising reports on the antioxidant, anti-inflammatory, anticariogenic antibacterial, antifungicidal, hepatoprotective, anti-atherosclerotic, immune enhancing potential require long-term and large cohort clinical studies. The main difficulty in the application of bee pollen in modern phytomedicine is related to the wide species-specific variation in its composition. Therefore, the variations may differently contribute to bee-pollen properties and biological activity and thus in therapeutic effects. In principle, we can unequivocally recommend bee pollen as a valuable dietary supplement. Although the bee-pollen components have potential bioactive and therapeutic properties, extensive research is required before bee pollen can be used in therapy. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Transcriptomics-based strain optimization tool for designing secondary metabolite overproducing strains of Streptomyces coelicolor.

PubMed

Kim, Minsuk; Yi, Jeong Sang; Lakshmanan, Meiyappan; Lee, Dong-Yup; Kim, Byung-Gee

2016-03-01

In silico model-driven analysis using genome-scale model of metabolism (GEM) has been recognized as a promising method for microbial strain improvement. However, most of the current GEM-based strain design algorithms based on flux balance analysis (FBA) heavily rely on the steady-state and optimality assumptions without considering any regulatory information. Thus, their practical usage is quite limited, especially in its application to secondary metabolites overproduction. In this study, we developed a transcriptomics-based strain optimization tool (tSOT) in order to overcome such limitations by integrating transcriptomic data into GEM. Initially, we evaluated existing algorithms for integrating transcriptomic data into GEM using Streptomyces coelicolor dataset, and identified iMAT algorithm as the only and the best algorithm for characterizing the secondary metabolism of S. coelicolor. Subsequently, we developed tSOT platform where iMAT is adopted to predict the reaction states, and successfully demonstrated its applicability to secondary metabolites overproduction by designing actinorhodin (ACT), a polyketide antibiotic, overproducing strain of S. coelicolor. Mutants overexpressing tSOT targets such as ribulose 5-phosphate 3-epimerase and NADP-dependent malic enzyme showed 2 and 1.8-fold increase in ACT production, thereby validating the tSOT prediction. It is expected that tSOT can be used for solving other metabolic engineering problems which could not be addressed by current strain design algorithms, especially for the secondary metabolite overproductions. © 2015 Wiley Periodicals, Inc.

Phylogenomic analysis of UDP glycosyltransferase 1 multigene family in Linum usitatissimum identified genes with varied expression patterns.

PubMed

Barvkar, Vitthal T; Pardeshi, Varsha C; Kale, Sandip M; Kadoo, Narendra Y; Gupta, Vidya S

2012-05-08

The glycosylation process, catalyzed by ubiquitous glycosyltransferase (GT) family enzymes, is a prevalent modification of plant secondary metabolites that regulates various functions such as hormone homeostasis, detoxification of xenobiotics and biosynthesis and storage of secondary metabolites. Flax (Linum usitatissimum L.) is a commercially grown oilseed crop, important because of its essential fatty acids and health promoting lignans. Identification and characterization of UDP glycosyltransferase (UGT) genes from flax could provide valuable basic information about this important gene family and help to explain the seed specific glycosylated metabolite accumulation and other processes in plants. Plant genome sequencing projects are useful to discover complexity within this gene family and also pave way for the development of functional genomics approaches. Taking advantage of the newly assembled draft genome sequence of flax, we identified 137 UDP glycosyltransferase (UGT) genes from flax using a conserved signature motif. Phylogenetic analysis of these protein sequences clustered them into 14 major groups (A-N). Expression patterns of these genes were investigated using publicly available expressed sequence tag (EST), microarray data and reverse transcription quantitative real time PCR (RT-qPCR). Seventy-three per cent of these genes (100 out of 137) showed expression evidence in 15 tissues examined and indicated varied expression profiles. The RT-qPCR results of 10 selected genes were also coherent with the digital expression analysis. Interestingly, five duplicated UGT genes were identified, which showed differential expression in various tissues. Of the seven intron loss/gain positions detected, two intron positions were conserved among most of the UGTs, although a clear relationship about the evolution of these genes could not be established. Comparison of the flax UGTs with orthologs from four other sequenced dicot genomes indicated that seven UGTs were flax diverged. Flax has a large number of UGT genes including few flax diverged ones. Phylogenetic analysis and expression profiles of these genes identified tissue and condition specific repertoire of UGT genes from this crop. This study would facilitate precise selection of candidate genes and their further characterization of substrate specificities and in planta functions.

Phylogenomic analysis of UDP glycosyltransferase 1 multigene family in Linum usitatissimum identified genes with varied expression patterns

PubMed Central

2012-01-01

Background The glycosylation process, catalyzed by ubiquitous glycosyltransferase (GT) family enzymes, is a prevalent modification of plant secondary metabolites that regulates various functions such as hormone homeostasis, detoxification of xenobiotics and biosynthesis and storage of secondary metabolites. Flax (Linum usitatissimum L.) is a commercially grown oilseed crop, important because of its essential fatty acids and health promoting lignans. Identification and characterization of UDP glycosyltransferase (UGT) genes from flax could provide valuable basic information about this important gene family and help to explain the seed specific glycosylated metabolite accumulation and other processes in plants. Plant genome sequencing projects are useful to discover complexity within this gene family and also pave way for the development of functional genomics approaches. Results Taking advantage of the newly assembled draft genome sequence of flax, we identified 137 UDP glycosyltransferase (UGT) genes from flax using a conserved signature motif. Phylogenetic analysis of these protein sequences clustered them into 14 major groups (A-N). Expression patterns of these genes were investigated using publicly available expressed sequence tag (EST), microarray data and reverse transcription quantitative real time PCR (RT-qPCR). Seventy-three per cent of these genes (100 out of 137) showed expression evidence in 15 tissues examined and indicated varied expression profiles. The RT-qPCR results of 10 selected genes were also coherent with the digital expression analysis. Interestingly, five duplicated UGT genes were identified, which showed differential expression in various tissues. Of the seven intron loss/gain positions detected, two intron positions were conserved among most of the UGTs, although a clear relationship about the evolution of these genes could not be established. Comparison of the flax UGTs with orthologs from four other sequenced dicot genomes indicated that seven UGTs were flax diverged. Conclusions Flax has a large number of UGT genes including few flax diverged ones. Phylogenetic analysis and expression profiles of these genes identified tissue and condition specific repertoire of UGT genes from this crop. This study would facilitate precise selection of candidate genes and their further characterization of substrate specificities and in planta functions. PMID:22568875

Systems biology and biotechnology of Streptomyces species for the production of secondary metabolites.

PubMed

Hwang, Kyu-Sang; Kim, Hyun Uk; Charusanti, Pep; Palsson, Bernhard Ø; Lee, Sang Yup

2014-01-01

Streptomyces species continue to attract attention as a source of novel medicinal compounds. Despite a long history of studies on these microorganisms, they still have many biochemical mysteries to be elucidated. Investigations of novel secondary metabolites and their biosynthetic gene clusters have been more systematized with high-throughput techniques through inspections of correlations among components of the primary and secondary metabolisms at the genome scale. Moreover, up-to-date information on the genome of Streptomyces species with emphasis on their secondary metabolism has been collected in the form of databases and knowledgebases, providing predictive information and enabling one to explore experimentally unrecognized biological spaces of secondary metabolism. Herein, we review recent trends in the systems biology and biotechnology of Streptomyces species. © 2013.

Epigenetic Manipulation of a Filamentous Fungus by the Proteasome-Inhibitor Bortezomib Induces the Production of an Additional Secondary Metabolite.

PubMed

VanderMolen, Karen M; Darveaux, Blaise A; Chen, Wei-Lun; Swanson, Steven M; Pearce, Cedric J; Oberlies, Nicholas H

2014-01-01

The use of epigenetic modifiers, such as histone deacetylase inhibitors and DNA methyltransferase inhibitors, has been explored increasingly as a technique to induce the production of additional microbial secondary metabolites. The application of such molecules to microbial cultures has been shown to upregulate otherwise suppressed genes, and in several cases has led to the production of new molecular structures. In this study, the proteasome inhibitor bortezomib was used to induce the production of an additional metabolite from a filamentous fungus (Pleosporales). The induced metabolite was previously isolated from a plant, but the configuration was not assigned until now; in addition, an analogue was isolated from a degraded sample, yielding a new compound. Proteasome inhibitors have not previously been used in this application and offer an additional tool for microbial genome mining.

Activation of cryptic metabolite production through gene disruption: Dimethyl furan-2,4-dicarboxylate produced by Streptomyces sahachiroi.

PubMed

Simkhada, Dinesh; Zhang, Huitu; Mori, Shogo; Williams, Howard; Watanabe, Coran M H

2013-01-01

At least 65% of all small molecule drugs on the market today are natural products, however, re-isolation of previously identified and characterized compounds has become a serious impediment to the discovery of new bioactive natural products. Here, genetic knockout of an unusual non-ribosomal peptide synthetase (NRPS) C-PCP-C module, aziA2, is performed resulting in the accumulation of the secondary metabolite, dimethyl furan-2,4-dicarboxylate. The cryptic metabolite represents the first non-azinomycin related compound to be isolated and characterized from the soil bacterium, S. sahachiroi. The results from this study suggest that abolishing production of otherwise predominant natural products through genetic knockout may constitute a means to "activate" the production of novel secondary metabolites that would otherwise lay dormant within microbial genome sequences.

Biotransformation of plant secondary metabolite decursin by Mycobacterium sp. PYR1001.

PubMed

Kim, Ki-Yeon; Lee, Sanghyun; Cha, Chang-Jun

2010-03-10

Decursin and its structural isomer decursinol angelate are major secondary metabolites in the root of Angelica gigas Nakai which possess several chemotherapeutic properties. We isolated bacteria capable of transforming decursin and determined metabolites and biotransformation kinetics. Decursinol angelate was not metabolized to any significant extent. Resting cells of Mycobacterium sp. PYR1001 were able to transform decursin. After 24 h incubation, 5 mM of decursin was completely transformed to a metabolite, the structure of which was determined by NMR and mass spectral analyses to be decursinol. This conversion was shown to be catalyzed by an esterase activity, and the activity was found to be specific for decursin. These results suggest that strain PYR1001 can be successfully used to transform decursin for the production of decursinol, a compound known to have cancer chemopreventive activity.

Trichoderma secondary metabolites that affect plant metabolism.

PubMed

Vinale, Francesco; Sivasithamparam, Krishnapillai; Ghisalberti, Emilio L; Ruocco, Michelina; Wood, Sheridan; Lorito, Matteo

2012-11-01

Recently, there have been many exciting new developments relating to the use of Trichoderma spp. as agents for biocontrol of pathogens and as plant growth promoters. Several mechanisms have been proposed to explain the positive effects of these microorganisms on the plant host. One factor that contributes to their beneficial biological activities is related to the wide variety of metabolites that they produce. These metabolites have been found not only to directly inhibit the growth and pathogenic activities of the parasites, but also to increase disease resistance by triggering the system of defence in the plant host. In addition, these metabolites are also capable of enhancing plant growth, which enables the plant to counteract the disease with compensatory vegetative growth by the augmented production of root and shoot systems. This review takes into account the Trichoderma secondary metabolites that affect plant metabolism and that may play an important role in the complex interactions of this biocontrol agent with the plant and pathogens.

The Metabolism of CIS - and Trans - Decalin in Fischer 344 Rats.

DTIC Science & Technology

1985-12-09

I. SUBJECT Teams lCeameu Onl MWMeE Affcary and Identify Joy blotib loumb. I FIELD GROUP *s. Ga. Decalin metabolism~, renal toxicity ruine metabolites...the metabolites of high-boiling cyclic hydrocarbons may provide valuable information regarding the renal toxicity mechanism. It was proposed that the...metabolism of other cyclic hydrocarbons be examined to see if a comonality of metabolism yielded similar toxic effects. The first chemical to be

Bioactive natural compounds from the plant endophytic fungi Pestalotiopsis spp.

PubMed

Wang, Kuiwu; Lei, Jinxiu; Wei, Jiguang; Yao, Nan

2012-11-01

The plant-endophytic strains of the fungus Pestalotiopsis (Amphisphaeriaceae) are distributed throughout the world. Previous chemical investigation of members of the genus resulted in the discovery of various bioactive secondary metabolites including chromones, cytosporones, polyketides, terpenoids and coumarins with diverse structural features. The present report reviews the papers, which have appeared in the literature till now, concerning the isolation, structural elucidation, and biological activities of the secondary metabolites from Pestalotiopsis species.

Aerobic Denitrification as an Innovative Method for In-Situ Biological Remediation of Contaminated Subsurface Sites

DTIC Science & Technology

1989-01-01

presumed subsurface conditon; * more rapid mineralization of organics and secondary metabolites ; * decrease in the biochemical oxygen demand and the...additon of nitrate would result in the more rapid mineralization of organic carbon and secondary metabolites . This was illustrated in this study with...and water. The list is far from complete. Many denitrifying species, such as those from the genera Moraxella and Achromobacter , are commonly found in

A below-ground herbivore shapes root defensive chemistry in natural plant populations

PubMed Central

Huber, Meret; Bont, Zoe; Fricke, Julia; Brillatz, Théo; Aziz, Zohra; Gershenzon, Jonathan; Erb, Matthias

2016-01-01

Plants display extensive intraspecific variation in secondary metabolites. However, the selective forces shaping this diversity remain often unknown, especially below ground. Using Taraxacum officinale and its major native insect root herbivore Melolontha melolontha, we tested whether below-ground herbivores drive intraspecific variation in root secondary metabolites. We found that high M. melolontha infestation levels over recent decades are associated with high concentrations of major root latex secondary metabolites across 21 central European T. officinale field populations. By cultivating offspring of these populations, we show that both heritable variation and phenotypic plasticity contribute to the observed differences. Furthermore, we demonstrate that the production of the sesquiterpene lactone taraxinic acid β-d-glucopyranosyl ester (TA-G) is costly in the absence, but beneficial in the presence of M. melolontha, resulting in divergent selection of TA-G. Our results highlight the role of soil-dwelling insects for the evolution of plant defences in nature. PMID:27009228

[Effect of different fertilization treatments on yield and secondary metabolites of Codonopsis pilosula].

PubMed

Hu, Jia-Dong; Mao, Ge; Zhang, Zhi-Wei; Ma, Cun-de; Liang, Zong-Suo; Xia, Guang-Dong; Dong, Juan-E

2017-08-01

The research studies the effect of different fertilization treatments on yield and accumulation of secondary metabolites of Codonopsis pilosula by using single factor randomized block design, in order to ensure reasonable harvesting time and fertilization ratio, and provide the basis for standardized cultivation of C. pilosula. According to the clustering results, the nitrogen fertilizer benefitted for the improvement of root diameter and biomass of C. pilosula. The phosphate fertilizer could promote the content of C. pilosula polysaccharide. The organic fertilizers could increase the content of lobetyolin. With the time going on, C. pilosula's yield, polysaccharide and ehanol-soluble extracts increased while the content of lobetyolin decreased. According to various factors, October is a more reasonable harvest period. Organic fertilizers are more helpful to the yield and accumulation of secondary metabolites of C. pilosula. Copyright© by the Chinese Pharmaceutical Association.

[Isolation, identification and structural characterization of secondary metabolites from amarine sponge-derived rare actinobacterium Dermacoccus sp. X4].

PubMed

Zhang, Yanfeng; Xu, Yong; Chen, Lei; Hu, Jun; Zhang, Xuecheng; Fang, Wei; Fang, Zemin; Xiao, Yazhong

2016-05-25

We isolated and identified the symbiotic and adnascent microorganisms from an unidentified sponge collected from 10-meter-deep seawater of the Paracel Islands in China. A total of 16 strains were obtained and identified. Through bacteriostatic activity assay, one of the strains, Dermacoccus sp. X4, was found to effectively inhibit the growth of Staphylococcus aureus. Subsequently, its secondary metabolites were purified by silica gel partition, octadecylsilane (ODS) reverse phase, Sephadex™LH-20 size exclusion, and C18 reverse phase chromatography. Using liquid chromatography, mass spectrometry, and nuclear magnetic resonance, three of the purified compounds were structurally characterized to be one 3-(4-hydroxybenzyl) hexahydropyrrolo [1,2-a]pyrazine-1,4-dione and two indole acid glycerides. This is the first report about indole acid glyceride isolated from microbial secondary metabolites, enriching marine drug candidate resources.

Emerging biopharmaceuticals from marine actinobacteria.

PubMed

Hassan, Syed Shams Ul; Anjum, Komal; Abbas, Syed Qamar; Akhter, Najeeb; Shagufta, Bibi Ibtesam; Shah, Sayed Asmat Ali; Tasneem, Umber

2017-01-01

Actinobacteria are quotidian microorganisms in the marine world, playing a crucial ecological role in the recycling of refractory biomaterials and producing novel secondary metabolites with pharmaceutical applications. Actinobacteria have been isolated from the huge area of marine organisms including sponges, tunicates, corals, mollusks, crabs, mangroves and seaweeds. Natural products investigation of the marine actinobacteria revealed that they can synthesize numerous natural products including alkaloids, polyketides, peptides, isoprenoids, phenazines, sterols, and others. These natural products have a potential to provide future drugs against crucial diseases like cancer, HIV, microbial and protozoal infections and severe inflammations. Therefore, marine actinobacteria portray as a pivotal resource for marine drugs. It is an upcoming field of research to probe a novel and pharmaceutically important secondary metabolites from marine actinobacteria. In this review, we attempt to summarize the present knowledge on the diversity, chemistry and mechanism of action of marine actinobacteria-derived secondary metabolites from 2007 to 2016. Copyright © 2016 Elsevier B.V. All rights reserved.

Chromatographic methods for metabolite profiling of virus- and phytoplasma-infected plants of Echinacea purpurea.

PubMed

Pellati, Federica; Epifano, Francesco; Contaldo, Nicoletta; Orlandini, Giulia; Cavicchi, Lisa; Genovese, Salvatore; Bertelli, Davide; Benvenuti, Stefania; Curini, Massimo; Bertaccini, Assunta; Bellardi, Maria Grazia

2011-10-12

This study was focused on the effects of virus and phytoplasma infections on the production of Echinacea purpurea (L.) Moench secondary metabolites, such as caffeic acid derivatives, alkamides, and essential oil. The identification of caffeic acid derivatives and alkamides was carried out by means of high-performance liquid chromatography-diode array detection (HPLC-DAD), HPLC-electrospray ionization-mass spectrometry (ESI-MS), and MS(2). Quantitative analysis of these compounds was carried out using HPLC-DAD. The results indicated that the presence of the two pathogens significantly decreases (P < 0.05) the content of cichoric acid, the main caffeic acid derivative. Regarding the main alkamide, dodeca-2E,4E,8Z,10E/Z-tetraenoic acid isobutylamide, a significant decrease (P < 0.05) in the content of this secondary metabolite was observed in virus-infected plants in comparison with healthy plants, while in the phytoplasma-infected sample the variation of this secondary metabolite was not appreciable. The % relative area of the E/Z isomers of this alkamide was also found to change in infected samples. The gas chromatography (GC) and GC-MS analysis of E. purpurea essential oil enabled the identification of 30 compounds. The main significant differences (P < 0.05) in the semiquantitative composition were observed for three components: limonene, cis-verbenol, and verbenone. The results indicate that the presence of virus and phytoplasma has an appreciable influence on the content of E. purpurea secondary metabolites, which is an important issue in defining the commercial quality, market value, and therapeutic efficacy of this herbal drug.

Cellular compartmentalization of secondary metabolism

USDA-ARS?s Scientific Manuscript database

Fungal secondary metabolism is often considered apart from the essential housekeeping functions of the cell. However, there are clear links between fundamental cellular metabolism and the biochemical pathways leading to secondary metabolite synthesis. Besides utilizing key biochemical precursors sh...

Production of secondary metabolites by some terverticillate penicillia on carbohydrate-rich and meat substrates.

PubMed

Núñez, Félix; Westphal, Carmen D; Bermúdez, Elena; Asensio, Miguel A

2007-12-01

Most terverticillate penicillia isolated from dry-cured meat products are toxigenic, but their ability to produce hazardous metabolites on meat-based substrates is not well known. The production of extrolites by selected terverticillate penicillia isolated from dry-cured ham has been studied on carbohydrate-rich media (malt extract agar, Czapek yeast autolysate agar, rice extract agar, and rice), meat extract triolein salt agar, and ham slices. Chloroform extracts from the selected strains grown on malt extract agar were toxic for the brine shrimp (Artemia salina) larvae and VERO cells at a concentration of 2 mg/ml, but 0.02 mg/ml produced no toxic effect. Analysis by high-pressure liquid chromatography (HPLC) coupled with photodiode array detection (DAD) or with mass spectrometry (MS) and an atmospheric pressure chemical ionization (APCI) source revealed different biologically active metabolites: cyclopiazonic acid and rugulovasine A from Penicillium commune; verrucosidin, anacine, puberuline, verrucofortine, and viridicatols from Penicillium polonicum; arisugacin and viridicatols from Penicillium echinulatum; and compactin and viridicatols from Penicillium solitum. Most of these metabolites, including the amino acid-derived compounds, were produced in the media containing high levels of carbohydrates. High concentrations of nitrogen compounds in the medium does not imply a greater production of the metabolites studied, not even those derived from the amino acids. However, molds growing on dry-cured ham are able to synthesize limited amounts of some secondary metabolites, a fact not previously reported. The combination of HPLC coupled with DAD and MS-APCI was useful for identification of closely related terverticillate Penicillium species from dry-cured ham. These techniques could be used to characterize the risk associated with the potential production of secondary metabolites in cured meats.

Antihepatotoxic Effect and Metabolite Profiling of Panicum turgidum Extract via UPLC-qTOF-MS.

PubMed

Farag, Mohamed A; El Fishawy, Ahlam M; El-Toumy, Sayed A; Amer, Khadiga F; Mansour, Ahmed M; Taha, Hala E

2016-07-01

Panicum turgidum , desert grass, has not reported any detailed phytochemical or biological study as yet. To establish P. turgidum secondary metabolite profile and to assess its antihepatotoxic effect. Ultra-performance liquid chromatography (UPLC) coupled to quadrupole high-resolution time of flight mass spectrometry (qTOF-MS) was used for large-scale secondary metabolites profiling in P. turgidum extract, alongside assessing median lethal dose (LD 50 ) and hepatoprotective effect against carbon tetrachloride (CCl 4 ) intoxication. A total of 39 metabolites were identified with flavonoids as the major class present as O/C -glycosides of luteolin, apigenin, isorhamnetin and naringenin, most of which are first time to be reported in Panicum sp. Antihepatotoxic effect of P. turgidum crude extract was revealed via improving several biochemical marker levels and mitigation against oxidative stress in the serum and liver tissues, compared with CCl4 intoxicated group and further confirmed by histopathological examination. This study reveals that P. turgidum , enriched in C -flavonoids, presents a novel source of safe antihepatotoxic agents and further demonstrates the efficacy of UPLC-MS metabolomics in the field of natural products drug discovery. UPLC coupled to qTOF-MS was used for large scale secondary metabolites profiling in P. turgidum .A total of 39 metabolites were identified with flavonoids amounting as the major metabolite class.Anti-hepatotoxic effect of P. turgidum extract was revealed via several biochemical markers and histopathological examination.This study reveals that P. turgidum , enriched in C -flavonoids, present a novel source of antihepatotoxic agents. Abbreviations used: UPLC: Ultra-performance liquid chromatography (UPLC), LD50: median lethal dose, MDA: malondialdehyde, GSH: glutathione reductase, CAT: catalase, SOD: superoxide dismutase, ALT: alanine aminotransferase, AST: aspartate aminotransferase, ALP: alkaline phosphatase, TG: triglycerides.

Antihepatotoxic Effect and Metabolite Profiling of Panicum turgidum Extract via UPLC-qTOF-MS

PubMed Central

Farag, Mohamed A.; El Fishawy, Ahlam M.; El-Toumy, Sayed A.; Amer, Khadiga F.; Mansour, Ahmed M.; Taha, Hala E.

2016-01-01

Background: Panicum turgidum, desert grass, has not reported any detailed phytochemical or biological study as yet Objective: To establish P. turgidum secondary metabolite profile and to assess its antihepatotoxic effect Materials and Methods: Ultra-performance liquid chromatography (UPLC) coupled to quadrupole high-resolution time of flight mass spectrometry (qTOF-MS) was used for large-scale secondary metabolites profiling in P. turgidum extract, alongside assessing median lethal dose (LD50) and hepatoprotective effect against carbon tetrachloride (CCl4) intoxication Results: A total of 39 metabolites were identified with flavonoids as the major class present as O/C-glycosides of luteolin, apigenin, isorhamnetin and naringenin, most of which are first time to be reported in Panicum sp. Antihepatotoxic effect of P. turgidum crude extract was revealed via improving several biochemical marker levels and mitigation against oxidative stress in the serum and liver tissues, compared with CCl4 intoxicated group and further confirmed by histopathological examination. Conclusion: This study reveals that P. turgidum, enriched in C-flavonoids, presents a novel source of safe antihepatotoxic agents and further demonstrates the efficacy of UPLC-MS metabolomics in the field of natural products drug discovery. SUMMARY UPLC coupled to qTOF-MS was used for large scale secondary metabolites profiling in P. turgidum.A total of 39 metabolites were identified with flavonoids amounting as the major metabolite class.Anti-hepatotoxic effect of P. turgidum extract was revealed via several biochemical markers and histopathological examination.This study reveals that P. turgidum, enriched in C-flavonoids, present a novel source of antihepatotoxic agents. Abbreviations used: UPLC: Ultra-performance liquid chromatography (UPLC), LD50: median lethal dose, MDA: malondialdehyde, GSH: glutathione reductase, CAT: catalase, SOD: superoxide dismutase, ALT: alanine aminotransferase, AST: aspartate aminotransferase, ALP: alkaline phosphatase, TG: triglycerides. PMID:27761073

The effects of cadmium chloride on secondary metabolite production in Vitis vinifera cv. cell suspension cultures.

PubMed

Cetin, Emine Sema; Babalik, Zehra; Hallac-Turk, Filiz; Gokturk-Baydar, Nilgun

2014-09-23

Plant secondary metabolites are possess several biological activities such as anti-mutagenic, anti-carcinogenic, anti-aging, etc. Cell suspension culture is one of the most effective systems to produce secondary metabolites. It is possible to increase the phenolic compounds and tocopherols by using cell suspensions. Studies on tocopherols production by cell suspension cultures are seldom and generally focused on seed oil plants. Although fresh grape, grape seed, pomace and grape seed oil had tocopherols, with our best knowledge, there is no research on tocopherol accumulation in the grape cell suspension cultures. In this study, it was aimed to determine the effects of cadmium chloride treatments on secondary metabolite production in cell suspension cultures of grapevine. Cell suspensions initiated from callus belonging to petiole tissue was used as a plant material. Cadmium chloride was applied to cell suspension cultures in different concentration (1.0 mM and 1.5 mM) to enhance secondary metabolite (total phenolics, total flavanols, total flavonols, trans-resveratrol, and α-, β-, γ- δ-tocopherols) production. Cells were harvested at two days intervals until the 6th day of cultures. Amounts of total phenolics, total flavanols and total flavonols; trans-resveratrol and tocopherols (α-, β-, γ- and δ-tocopherols) and dry cell weights were determined in the harvested cells. Phenolic contents were significantly affected by the sampling time and cadmium concentrations. The highest values of total phenolic (168.82 mg/100 g), total flavanol (15.94 mg/100 g), total flavonol (14.73 mg/100 g) and trans-resveratrol (490.76 μg/100 g) were found in cells treated with 1.0 mM CdCl2 and harvested at day 2. Contents of tocopherols in the cells cultured in the presence of 1.0 mM CdCl2 gradually increased during the culture period and the highest values of α, β and γ tocopherols (145.61, 25.52 and 18.56 μg/100 g) were detected in the cell cultures collected at day 6. As a conclusion, secondary metabolite contents were increased by cadmium chloride application and sampling time, while dry cell weights was reduced by cadmium chloride treatments.

Iron and its complexation by phenolic cellular metabolites

PubMed Central

Chobot, Vladimir

2010-01-01

Iron is a transition metal that forms chelates and complexes with various organic compounds, also with phenolic plant secondary metabolites. The ligands of iron affect the redox potential of iron. Electrons may be transferred either to hydroxyl radicals, hydrogen peroxide or molecular oxygen. In the first case, oxidative stress is decreased, in the latter two cases, oxidative stress is increased. This milieu-dependent mode of action may explain the non-linear mode of action of juglone and other secondary metabolites. Attention to this phenomenon may help to explain idiosyncratic and often nonlinear effects that result in biological assays. Current chemical assays are discussed that help to explore these aspects of redox chemistry. PMID:20592800

Secondary metabolites from Penicillium pinophilum SD-272, a marine sediment-derived fungus.

PubMed

Wang, Ming-Hui; Li, Xiao-Ming; Li, Chun-Shun; Ji, Nai-Yun; Wang, Bin-Gui

2013-06-21

Two new secondary metabolites, namely, pinodiketopiperazine A (1) and 6,7-dihydroxy-3-methoxy-3-methylphthalide (2), along with alternariol 2,4-dimethyl ether (3) and L-5-oxoproline methyl ester (4), which were isolated from a natural source for the first time but have been previously synthesized, were characterized from the marine sediment-derived fungus Penicillium pinophilum SD-272. In addition, six known metabolites (5-10) were also identified. Their structures were elucidated by analysis of the NMR and mass spectroscopic data. The absolute configuration of compound 1 was determined by experimental and calculated ECD spectra. Compound 2 displayed potent brine shrimp (Artemia salina) lethality with LD₅₀ 11.2 μM.

Influence of carbohydrates on secondary metabolism in Fusarium avenaceum.

PubMed

Sørensen, Jens Laurids; Giese, Henriette

2013-09-24

Fusarium avenaceum is a widespread pathogen of important crops in the temperate climate zones that can produce many bioactive secondary metabolites, including moniliformin, fusarin C, antibiotic Y, 2-amino-14,16-dimethyloctadecan-3-ol (2-AOD-3-ol), chlamydosporol, aurofusarin and enniatins. Here, we examine the production of these secondary metabolites in response to cultivation on different carbon sources in order to gain insight into the regulation and production of secondary metabolites in F. avenaceum. Seven monosaccharides (arabinose, xylose, fructose, sorbose, galactose, mannose, glucose), five disaccharides (cellobiose, lactose, maltose, sucrose and trehalose) and three polysaccharides (dextrin, inulin and xylan) were used as substrates. Three F. avenaceum strains were used in the experiments. These were all able to grow and produce aurofusarin on the tested carbon sources. Moniliformin and enniatins were produced on all carbon types, except on lactose, which suggest a common conserved regulation mechanism. Differences in the strains was observed for production of fusarin C, 2-AOD-3-ol, chlamydosporol and antibiotic Y, which suggests that carbon source plays a role in the regulation of their biosynthesis.

The regulatory mechanism of fungal elicitor-induced secondary metabolite biosynthesis in medical plants.

PubMed

Zhai, Xin; Jia, Min; Chen, Ling; Zheng, Cheng-Jian; Rahman, Khalid; Han, Ting; Qin, Lu-Ping

2017-03-01

A wide range of external stress stimuli trigger plant cells to undergo complex network of reactions that ultimately lead to the synthesis and accumulation of secondary metabolites. Accumulation of such metabolites often occurs in plants subjected to stresses including various elicitors or signal molecules. Throughout evolution, endophytic fungi, an important constituent in the environment of medicinal plants, have known to form long-term stable and mutually beneficial symbiosis with medicinal plants. The endophytic fungal elicitor can rapidly and specifically induce the expression of specific genes in medicinal plants which can result in the activation of a series of specific secondary metabolic pathways resulting in the significant accumulation of active ingredients. Here we summarize the progress made on the mechanisms of fungal elicitor including elicitor signal recognition, signal transduction, gene expression and activation of the key enzymes and its application. This review provides guidance on studies which may be conducted to promote the efficient synthesis and accumulation of active ingredients by the endogenous fungal elicitor in medicinal plant cells, and provides new ideas and methods of studying the regulation of secondary metabolism in medicinal plants.

The Laurencia Paradox: An Endless Source of Chemodiversity.

PubMed

Harizani, Maria; Ioannou, Efstathia; Roussis, Vassilios

Nature, the most prolific source of biological and chemical diversity, has provided mankind with treatments for health problems since ancient times and continues to be the most promising reservoir of bioactive chemicals for the development of modern drugs. In addition to the terrestrial organisms that still remain a promising source of new bioactive metabolites, the marine environment, covering approximately 70% of the Earth's surface and containing a largely unexplored biodiversity, offers an enormous resource for the discovery of novel compounds. According to the MarinLit database, more than 27,000 metabolites from marine macro- and microorganisms have been isolated to date providing material and key structures for the development of new products in the pharmaceutical, food, cosmeceutical, chemical, and agrochemical sectors. Algae, which thrive in the euphotic zone, were among the first marine organisms that were investigated as sources of food, nutritional supplements, soil fertilizers, and bioactive metabolites.Red algae of the genus Laurencia are accepted unanimously as one of the richest sources of new secondary metabolites. Their cosmopolitan distribution, along with the chemical variation influenced to a significant degree by environmental and genetic factors, have resulted in an endless parade of metabolites, often featuring multiple halogenation sites.The present contribution, covering the literature until August 2015, offers a comprehensive view of the chemical wealth and the taxonomic problems currently impeding chemical and biological investigations of the genus Laurencia. Since mollusks feeding on Laurencia are, in many cases, bioaccumulating, and utilize algal metabolites as chemical weaponry against natural enemies, metabolites of postulated dietary origin of sea hares that feed on Laurencia species are also included in the present review. Altogether, 1047 secondary metabolites, often featuring new carbocyclic skeletons, have been included.The chapter addresses: (1) the "Laurencia complex", the botanical description and the growth and population dynamics of the genus, as well as its chemical diversity and ecological relations; (2) the secondary metabolites, which are organized according to their chemical structures and are classified into sesquiterpenes, diterpenes, triterpenes, acetogenins, indoles, aromatic compounds, steroids, and miscellaneous compounds, as well as their sources of isolation which are depicted in tabulated form, and (3) the biological activity organized according to the biological target and the ecological functions of Laurencia metabolites.

Exploring traditional aus-type rice for metabolites conferring drought tolerance.

PubMed

Casartelli, Alberto; Riewe, David; Hubberten, Hans Michael; Altmann, Thomas; Hoefgen, Rainer; Heuer, Sigrid

2018-01-25

Traditional varieties and landraces belonging to the aus-type group of rice (Oryza sativa L.) are known to be highly tolerant to environmental stresses, such as drought and heat, and are therefore recognized as a valuable genetic resource for crop improvement. Using two aus-type (Dular, N22) and two drought intolerant irrigated varieties (IR64, IR74) an untargeted metabolomics analysis was conducted to identify drought-responsive metabolites associated with tolerance. The superior drought tolerance of Dular and N22 compared with the irrigated varieties was confirmed by phenotyping plants grown to maturity after imposing severe drought stress in a dry-down treatment. Dular and N22 did not show a significant reduction in grain yield compared to well-watered control plants, whereas the intolerant varieties showed a significant reduction in both, total spikelet number and grain yield. The metabolomics analysis was conducted with shoot and root samples of plants at the tillering stage at the end of the dry-down treatment. The data revealed an overall higher accumulation of N-rich metabolites (amino acids and nucleotide-related metabolites allantoin and uridine) in shoots of the tolerant varieties. In roots, the aus-type varieties were characterised by a higher reduction of metabolites representative of glycolysis and the TCA cycle, such as malate, glyceric acid and glyceric acid-3-phosphate. On the other hand, the oligosaccharide raffinose showed a higher fold increase in both, shoots and roots of the sensitive genotypes. The data further showed that, for certain drought-responsive metabolites, differences between the contrasting rice varieties were already evident under well-watered control conditions. The drought tolerance-related metabolites identified in the aus-type varieties provide a valuable set of protective compounds and an entry point for assessing genetic diversity in the underlying pathways for developing drought tolerant rice and other crops.

Secondary metabolites and other small molecules as intercellular pathogenic signals.

PubMed

Dufour, Nicholas; Rao, Reeta Prusty

2011-01-01

Microorganisms often use small chemicals or secondary metabolites as informational cues to regulate gene expression. It is hypothesized that microorganisms exploit these signals to gain a competitive advantage. Here, we present examples of pathogens that use this strategy to exclude other microorganisms from the site of infection. An emerging theme is that inhibiting these systems presents a novel approach to antimicrobial therapies. © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

[Secondary metabolites accumulating and geoherbs formation under enviromental stress].

PubMed

Huang, Lu-Qi; Guo, Lan-Ping

2007-02-01

This paper analyzed how habitat affected the formation of geoherbs after summarizing the influences of environmental stress on plants growth, especially on theirs secondary metabolites accumulating, and introducing 4 kinds hypothesis about environmental stress affects plants. It was then pointed out that environmental stress may have advantage on the formation of geoherbs. The stress effect hypothesis on forming geoherbs was brought forward, and the ways and methods on study the geoherbs under environmental stress was discussed.

Application of an Efficient Gene Targeting System Linking Secondary Metabolites to their Biosynthetic Genes in Aspergillus terreus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guo, Chun-Jun; Knox, Benjamin P.; Sanchez, James F.

2013-07-19

Nonribosomal peptides (NRPs) are natural products biosynthesized by NRP synthetases. A kusA-, pyrG- mutant strain of Aspergillusterreus NIH 2624 was developed that greatly facilitated the gene targeting efficiency in this organism. Application of this tool allowed us to link four major types of NRP related secondary metabolites to their responsible genes in A. terreus. In addition, an NRP related melanin synthetase was also identified in this species.

Spectroscopic determination of ecologically relevant plant secondary metabolites

DOE PAGES

Couture, John J.; Singh, Aditya; Rubert-Nason, Kennedy F.; ...

2016-07-23

Spectroscopy has recently emerged as an effective method to accurately characterize leaf biochemistry in living tissue through the application of chemometric approaches to foliar optical data, but this approach has not been widely used for plant secondary metabolites. Here in this paper, we examine the ability of reflectance spectroscopy to quantify specific phenolic compounds in trembling aspen (Populus tremuloides) and paper birch (Betula papyrifera) that play influential roles in ecosystem functioning related to trophic-level interactions and nutrient cycling.

antiSMASH 2.0--a versatile platform for genome mining of secondary metabolite producers.

PubMed

Blin, Kai; Medema, Marnix H; Kazempour, Daniyal; Fischbach, Michael A; Breitling, Rainer; Takano, Eriko; Weber, Tilmann

2013-07-01

Microbial secondary metabolites are a potent source of antibiotics and other pharmaceuticals. Genome mining of their biosynthetic gene clusters has become a key method to accelerate their identification and characterization. In 2011, we developed antiSMASH, a web-based analysis platform that automates this process. Here, we present the highly improved antiSMASH 2.0 release, available at http://antismash.secondarymetabolites.org/. For the new version, antiSMASH was entirely re-designed using a plug-and-play concept that allows easy integration of novel predictor or output modules. antiSMASH 2.0 now supports input of multiple related sequences simultaneously (multi-FASTA/GenBank/EMBL), which allows the analysis of draft genomes comprising multiple contigs. Moreover, direct analysis of protein sequences is now possible. antiSMASH 2.0 has also been equipped with the capacity to detect additional classes of secondary metabolites, including oligosaccharide antibiotics, phenazines, thiopeptides, homo-serine lactones, phosphonates and furans. The algorithm for predicting the core structure of the cluster end product is now also covering lantipeptides, in addition to polyketides and non-ribosomal peptides. The antiSMASH ClusterBlast functionality has been extended to identify sub-clusters involved in the biosynthesis of specific chemical building blocks. The new features currently make antiSMASH 2.0 the most comprehensive resource for identifying and analyzing novel secondary metabolite biosynthetic pathways in microorganisms.

Online identification of chlorogenic acids, sesquiterpene lactones, and flavonoids in the Brazilian arnica Lychnophora ericoides Mart. (Asteraceae) leaves by HPLC-DAD-MS and HPLC-DAD-MS/MS and a validated HPLC-DAD method for their simultaneous analysis.

PubMed

Gobbo-Neto, Leonardo; Lopes, Norberto P

2008-02-27

Lychnophora ericoides Mart. (Asteraceae, Vernonieae) is a plant, endemic to Brazil, with occurrence restricted to the "cerrado" biome. Traditional medicine employs alcoholic and aqueous-alcoholic preparations of leaves from this species for the treatment of wounds, inflammation, and pain. Furthermore, leaves of L. ericoides are also widely used as flavorings for the Brazilian traditional spirit "cachaça". A method has been developed for the extraction and HPLC-DAD analysis of the secondary metabolites of L. ericoides leaves. This analytical method was validated with 11 secondary metabolites chosen to represent the different classes and polarities of secondary metabolites occurring in L. ericoides leaves, and good responses were obtained for each validation parameter analyzed. The same HPLC analytical method was also employed for online secondary metabolite identification by HPLC-DAD-MS and HPLC-DAD-MS/MS, leading to the identification of di- C-glucosylflavones, coumaroylglucosylflavonols, flavone, flavanones, flavonols, chalcones, goyazensolide, and eremantholide-type sesquiterpene lactones and positional isomeric series of chlorogenic acids possessing caffeic and/or ferulic moieties. Among the 52 chromatographic peaks observed, 36 were fully identified and 8 were attributed to compounds belonging to series of caffeoylferuloylquinic and diferuloylquinic acids that could not be individualized from each other.

Disruption of rimP-SC, encoding a ribosome assembly cofactor, markedly enhances the production of several antibiotics in Streptomyces coelicolor

PubMed Central

2013-01-01

Background Ribosome assembly cofactor RimP is one of the auxiliary proteins required for maturation of the 30S subunit in Escherichia coli. Although RimP in protein synthesis is important, its role in secondary metabolites biosynthesis has not been reported so far. Considering the close relationship between protein synthesis and the production of secondary metabolites, the function of ribosome assembly cofactor RimP on antibiotics production was studied in Streptomyces coelicolor and Streptomyces venezuelae. Results In this study, the rimP homologue rimP-SC was identified and cloned from Streptomyces coelicolor. Disruption of rimP-SC led to enhanced production of actinorhodin and calcium-dependent antibiotics by promoting the transcription of actII-ORF4 and cdaR. Further experiments demonstrated that MetK was one of the reasons for the increment of antibiotics production. In addition, rimP-SC disruption mutant could be used as a host to produce more peptidyl nucleoside antibiotics (polyoxin or nikkomycin) than the wild-type strain. Likewise, disruption of rimP-SV of Streptomyces venezuelae also significantly stimulated jadomycin production, suggesting that enhanced antibiotics production might be widespread in many other Streptomyces species. Conclusion These results established an important relationship between ribosome assembly cofactor and secondary metabolites biosynthesis and provided an approach for yield improvement of secondary metabolites in Streptomyces. PMID:23815792

[Research of mechanism of secondary metabolites of phenolic acids in Salvia miltiorrhiza hairy root induced by jasmonate].

PubMed

Li, Wenyuan; Gao, Wei; Zhao, Jing; Cui, Guanghong; Shao, Aijuan; Huang, Luqi

2012-01-01

To study the mechanism of secondary metabolites of some phenolic acids in the hairy roots of Salvia miltiorrhiza induced by methyl jasmonate. The hairy roots of S. miltiorrhiza were induced with methyl jasmonate (100 micromol x L(-1)) and collected at 0, 12, 24, 36 h after treatment. Real-time quantitative PCR was used for detecting the mRNA expression level of the key enzyme genes on the secondary metabolites pathway of rosmarinic acid, while a LC-MS method was developed to determine the content of rosmarinic acid, caffeic acid and salvianolic acid B. The concentration of phenolic acids grew up and accumulated quickly in the hairy roots with exogenous signal molecule MJ induced, and it was showed that the content of CA and RA reached the maximum after 24 h and the content of LAB reached the maximum in 36 h by MJ induced. The induction mechanism may be activated with different levels of RA synthesis in PAL, 4CL, C4H genes on the key enzyme phenylalanine pathway and TAT, HPPR genes on tyrosine pathway. The time of gene expression was different, among them, 4CL and PAL genes were more important. In a word, the result can provide some basis data about the mechanism of secondary metabolites of phenolic acids for further research.

Grapevine Plasticity in Response to an Altered Microclimate: Sauvignon Blanc Modulates Specific Metabolites in Response to Increased Berry Exposure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Young, Philip R.; Eyeghe-Bickong, Hans A.; du Plessis, Kari

In this paper, the metabolic and physiological impacts of an altered microclimate on quality-associated primary and secondary metabolites in grape (Vitis vinifera) ‘Sauvignon Blanc’ berries was determined in a high-altitude vineyard. The leaf and lateral shoot removal in the bunch zones altered the microclimate by increasing the exposure of the berries. The physical parameters (berry diameter and weight), primary metabolites (sugars and organic acids), as well as bunch temperature and leaf water potential were predominantly not affected by the treatment. The increased exposure led to higher levels of specific carotenoids and volatile terpenoids in the exposed berries, with earlier berrymore » stages reacting distinctly from the later developmental stages. Plastic/nonplastic metabolite responses could be further classified to identify metabolites that were developmentally controlled and/or responded to the treatment in a predictable fashion (assessed over two consecutive vintages). The study demonstrates that grapevine berries exhibit a degree of plasticity within their secondary metabolites and respond physiologically to the increased exposure by increasing metabolites with potential antioxidant activity. Finally, taken together, the data provide evidence that the underlying physiological responses relate to the maintenance of stress pathways by modulating antioxidant molecules in the berries.« less

Grapevine Plasticity in Response to an Altered Microclimate: Sauvignon Blanc Modulates Specific Metabolites in Response to Increased Berry Exposure

DOE PAGES

Young, Philip R.; Eyeghe-Bickong, Hans A.; du Plessis, Kari; ...

2015-12-01

In this paper, the metabolic and physiological impacts of an altered microclimate on quality-associated primary and secondary metabolites in grape (Vitis vinifera) ‘Sauvignon Blanc’ berries was determined in a high-altitude vineyard. The leaf and lateral shoot removal in the bunch zones altered the microclimate by increasing the exposure of the berries. The physical parameters (berry diameter and weight), primary metabolites (sugars and organic acids), as well as bunch temperature and leaf water potential were predominantly not affected by the treatment. The increased exposure led to higher levels of specific carotenoids and volatile terpenoids in the exposed berries, with earlier berrymore » stages reacting distinctly from the later developmental stages. Plastic/nonplastic metabolite responses could be further classified to identify metabolites that were developmentally controlled and/or responded to the treatment in a predictable fashion (assessed over two consecutive vintages). The study demonstrates that grapevine berries exhibit a degree of plasticity within their secondary metabolites and respond physiologically to the increased exposure by increasing metabolites with potential antioxidant activity. Finally, taken together, the data provide evidence that the underlying physiological responses relate to the maintenance of stress pathways by modulating antioxidant molecules in the berries.« less

Grapevine Plasticity in Response to an Altered Microclimate: Sauvignon Blanc Modulates Specific Metabolites in Response to Increased Berry Exposure.

PubMed

Young, Philip R; Eyeghe-Bickong, Hans A; du Plessis, Kari; Alexandersson, Erik; Jacobson, Dan A; Coetzee, Zelmari; Deloire, Alain; Vivier, Melané A

2016-03-01

In this study, the metabolic and physiological impacts of an altered microclimate on quality-associated primary and secondary metabolites in grape (Vitis vinifera) 'Sauvignon Blanc' berries was determined in a high-altitude vineyard. The leaf and lateral shoot removal in the bunch zones altered the microclimate by increasing the exposure of the berries. The physical parameters (berry diameter and weight), primary metabolites (sugars and organic acids), as well as bunch temperature and leaf water potential were predominantly not affected by the treatment. The increased exposure led to higher levels of specific carotenoids and volatile terpenoids in the exposed berries, with earlier berry stages reacting distinctly from the later developmental stages. Plastic/nonplastic metabolite responses could be further classified to identify metabolites that were developmentally controlled and/or responded to the treatment in a predictable fashion (assessed over two consecutive vintages). The study demonstrates that grapevine berries exhibit a degree of plasticity within their secondary metabolites and respond physiologically to the increased exposure by increasing metabolites with potential antioxidant activity. Taken together, the data provide evidence that the underlying physiological responses relate to the maintenance of stress pathways by modulating antioxidant molecules in the berries. © 2016 American Society of Plant Biologists. All Rights Reserved.

Grapevine Plasticity in Response to an Altered Microclimate: Sauvignon Blanc Modulates Specific Metabolites in Response to Increased Berry Exposure1

PubMed Central

du Plessis, Kari; Jacobson, Dan A.

2016-01-01

In this study, the metabolic and physiological impacts of an altered microclimate on quality-associated primary and secondary metabolites in grape (Vitis vinifera) ‘Sauvignon Blanc’ berries was determined in a high-altitude vineyard. The leaf and lateral shoot removal in the bunch zones altered the microclimate by increasing the exposure of the berries. The physical parameters (berry diameter and weight), primary metabolites (sugars and organic acids), as well as bunch temperature and leaf water potential were predominantly not affected by the treatment. The increased exposure led to higher levels of specific carotenoids and volatile terpenoids in the exposed berries, with earlier berry stages reacting distinctly from the later developmental stages. Plastic/nonplastic metabolite responses could be further classified to identify metabolites that were developmentally controlled and/or responded to the treatment in a predictable fashion (assessed over two consecutive vintages). The study demonstrates that grapevine berries exhibit a degree of plasticity within their secondary metabolites and respond physiologically to the increased exposure by increasing metabolites with potential antioxidant activity. Taken together, the data provide evidence that the underlying physiological responses relate to the maintenance of stress pathways by modulating antioxidant molecules in the berries. PMID:26628747

Industrial Microorganisms.

ERIC Educational Resources Information Center

Phaff, Herman J.

1981-01-01

Describes industrially important yeasts, molds, bacteria, and actinomycetes. Discussed in detail are microbial products, such as primary metabolites, secondary metabolites, enzymes, and capsular polysaccharides. Traces the historical background of human cell culture, mentioning recombinant DNA research and hybridization of normal mammalian cells…

Endocidal Regulation of Secondary Metabolites in the Producing Organisms

PubMed Central

Li, Shiyou; Wang, Ping; Yuan, Wei; Su, Zushang; Bullard, Steven H.

2016-01-01

Secondary metabolites are defined as organic compounds that are not directly involved in the normal growth, development, and reproduction of an organism. They are widely believed to be responsible for interactions between the producing organism and its environment, with the producer avoiding their toxicities. In our experiments, however, none of the randomly selected 44 species representing different groups of plants and insects can avoid autotoxicity by its endogenous metabolites once made available. We coined the term endocides (endogenous biocides) to describe such metabolites that can poison or inhibit the parent via induced biosynthesis or external applications. Dosage-dependent endocides can selectively induce morphological mutations in the parent organism (e.g., shrubbiness/dwarfism, pleiocotyly, abnormal leaf morphogenesis, disturbed phyllotaxis, fasciated stems, and variegation in plants), inhibit its growth, development, and reproduction and cause death than non-closely related species. The propagule, as well as the organism itself contains or produces adequate endocides to kill itself. PMID:27389069

Sample preparation for an optimized extraction of localized metabolites in lichens: Application to Pseudevernia furfuracea.

PubMed

Komaty, Sarah; Letertre, Marine; Dang, Huyen Duong; Jungnickel, Harald; Laux, Peter; Luch, Andreas; Carrié, Daniel; Merdrignac-Conanec, Odile; Bazureau, Jean-Pierre; Gauffre, Fabienne; Tomasi, Sophie; Paquin, Ludovic

2016-04-01

Lichens are symbiotic organisms known for producing unique secondary metabolites with attractive cosmetic and pharmacological properties. In this paper, we investigated three standard methods of preparation of Pseudevernia furfuracea (blender grinding, ball milling, pestle and mortar). The materials obtained were characterized by electronic microscopy, nitrogen adsorption and compared from the point of view of extraction. Their microscopic structure is related to extraction efficiency. In addition, it is shown using thalline reactions and mass spectrometry mapping (TOF-SIMS) that these metabolites are not evenly distributed throughout the organism. Particularly, atranorin (a secondary metabolite of interest) is mainly present in the cortex of P. furfuracea. Finally, using microwave assisted extraction (MAE) we obtained evidence that an appropriate preparation can increase the extraction efficiency of atranorin by a factor of five. Copyright © 2016 Elsevier B.V. All rights reserved.

Secondary metabolites produced by the marine bacterium Halobacillus salinus that inhibit quorum sensing-controlled phenotypes in gram-negative bacteria.

PubMed

Teasdale, Margaret E; Liu, Jiayuan; Wallace, Joselynn; Akhlaghi, Fatemeh; Rowley, David C

2009-02-01

Certain bacteria use cell-to-cell chemical communication to coordinate community-wide phenotypic expression, including swarming motility, antibiotic biosynthesis, and biofilm production. Here we present a marine gram-positive bacterium that secretes secondary metabolites capable of quenching quorum sensing-controlled behaviors in several gram-negative reporter strains. Isolate C42, a Halobacillus salinus strain obtained from a sea grass sample, inhibits bioluminescence production by Vibrio harveyi in cocultivation experiments. With the use of bioassay-guided fractionation, two phenethylamide metabolites were identified as the active agents. The compounds additionally inhibit quorum sensing-regulated violacein biosynthesis by Chromobacterium violaceum CV026 and green fluorescent protein production by Escherichia coli JB525. Bacterial growth was unaffected at concentrations below 200 microg/ml. Evidence is presented that these nontoxic metabolites may act as antagonists of bacterial quorum sensing by competing with N-acyl homoserine lactones for receptor binding.

Towards eco-friendly crop protection: natural deep eutectic solvents and defensive secondary metabolites.

PubMed

Mouden, Sanae; Klinkhamer, Peter G L; Choi, Young Hae; Leiss, Kirsten A

2017-01-01

With mounting concerns over health and environmental effects of pesticides, the search for environmentally acceptable substitutes has amplified. Plant secondary metabolites appear in the horizon as an attractive solution for green crop protection. This paper reviews the need for changes in the techniques and compounds that, until recently, have been the mainstay for dealing with pest insects. Here we describe and discuss main strategies for selecting plant-derived metabolites as candidates for sustainable agriculture. The second part surveys ten important insecticidal compounds, with special emphasis on those involved in human health. Many of these insecticidal metabolites, however, are crystalline solids with limited solubility which might potentially hamper commercial formulation. As such, we introduce the concept of natural deep eutectic solvents for enhancing solubility and stability of such compounds. The concept, principles and examples of green pest control discussed here offer a new suite of environmental-friendly tools designed to promote and adopt sustainable agriculture.

A Comparative Proteomic Analysis of the Buds and the Young Expanding Leaves of the Tea Plant (Camellia sinensis L.)

PubMed Central

Li, Qin; Li, Juan; Liu, Shuoqian; Huang, Jianan; Lin, Haiyan; Wang, Kunbo; Cheng, Xiaomei; Liu, Zhonghua

2015-01-01

Tea (Camellia sinensis L.) is a perennial woody plant that is widely cultivated to produce a popular non-alcoholic beverage; this beverage has received much attention due to its pleasant flavor and bioactive ingredients, particularly several important secondary metabolites. Due to the significant changes in the metabolite contents of the buds and the young expanding leaves of tea plants, high-performance liquid chromatography (HPLC) analysis and isobaric tags for relative and absolute quantitation (iTRAQ) analysis were performed. A total of 233 differentially expressed proteins were identified. Among these, 116 proteins were up-regulated and 117 proteins were down-regulated in the young expanding leaves compared with the buds. A large array of diverse functions was revealed, including roles in energy and carbohydrate metabolism, secondary metabolite metabolism, nucleic acid and protein metabolism, and photosynthesis- and defense-related processes. These results suggest that polyphenol biosynthesis- and photosynthesis-related proteins regulate the secondary metabolite content of tea plants. The energy and antioxidant metabolism-related proteins may promote tea leaf development. However, reverse transcription quantitative real-time PCR (RT-qPCR) showed that the protein expression levels were not well correlated with the gene expression levels. These findings improve our understanding of the molecular mechanism of the changes in the metabolite content of the buds and the young expanding leaves of tea plants. PMID:26096006

Fungal Anticancer Metabolites: Synthesis Towards Drug Discovery.

PubMed

Barbero, Margherita; Artuso, Emma; Prandi, Cristina

2018-01-01

Fungi are a well-known and valuable source of compounds of therapeutic relevance, in particular of novel anticancer compounds. Although seldom obtainable through isolation from the natural source, the total organic synthesis still remains one of the most efficient alternatives to resupply them. Furthermore, natural product total synthesis is a valuable tool not only for discovery of new complex biologically active compounds but also for the development of innovative methodologies in enantioselective organic synthesis. We undertook an in-depth literature searching by using chemical bibliographic databases (SciFinder, Reaxys) in order to have a comprehensive insight into the wide research field. The literature has been then screened, refining the obtained results by subject terms focused on both biological activity and innovative synthetic procedures. The literature on fungal metabolites has been recently reviewed and these publications have been used as a base from which we consider the synthetic feasibility of the most promising compounds, in terms of anticancer properties and drug development. In this paper, compounds are classified according to their chemical structure. This review summarizes the anticancer potential of fungal metabolites, highlighting the role of total synthesis outlining the feasibility of innovative synthetic procedures that facilitate the development of fungal metabolites into drugs that may become a real future perspective. To our knowledge, this review is the first effort to deal with the total synthesis of these active fungi metabolites and demonstrates that total chemical synthesis is a fruitful means of yielding fungal derivatives as aided by recent technological and innovative advancements. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Effects of enhanced UV-B radiation on secondary metabolites in forage plants and potential consequences for multiple trophic responses involving mammalian herbivores

NASA Astrophysics Data System (ADS)

Thines, Nicole J.; Bassman, John H.; Shipley, Lisa A.; Slusser, James R.

2004-10-01

Herbivores represent the interface between primary production and higher trophic levels. The effects of enhanced UV-B radiation on microbes, invertebrate herbivores, and detritivores has received limited study in both terrestrial and aquatic ecosystems. However, although direct effects (e.g. melanoma, cataracts) on mammals have been documented, indirect effects (e.g., resulting from changes in plant chemistry) of enhanced UV-B on mammalian herbivores have not been evaluated. Although the diet of mammalian herbivores has little effect on nutritional quality for their associated predators, to the extent changes in plant chemistry affect aspects of population dynamics (e.g., growth, fecundity, densities), higher trophic levels can be affected. In this study, different forage species of varying inherent levels of key secondary metabolites are being grown in the field under either ambient or ambient plus supplemental UV-B radiation simulating a 15% stratospheric ozone depletion for Pullman, Washington. At various time intervals, foliage is being sampled and analyzed for changes in secondary metabolites and other attributes. Using controlled feeding trials, changes in plant secondary metabolites are being related to preference and digestibility in specialist and generalist mammalian hindgut herbivores, digestion in ruminants and non-ruminants, and to selected aspects of population dynamics in mammalian herbivores. Results suggest how UV-B-induced changes in plant secondary chemistry affect animal nutrition, and thus animal productivity in a range of mammalian herbivores. Reductions in palatability and digestibility of plant material along with reductions in fecundity and other aspects of population dynamics could have significant economic ramifications for farmers, ranchers and wildlife biologists.

Identification of a signal that mediates the crosstalk between biosynthetic gene clusters for the antibiotics 2,4-diacetylphloroglucinol and pyoluteorin in Pseudomonas protegens Pf-5

USDA-ARS?s Scientific Manuscript database

Pseudomonas protegens Pf-5 produces at least seven secondary metabolites with anti-microbial activity. The production of two of these metabolites, 2,4-diacetylphloroglucinol (2,4-DAPG) and pyoluteorin, is coordinately regulated. Each of the two metabolites functions as an intercellular signal, ind...

Simultaneous production of rhamnolipids, 2-alkyl-4-hydroxyquinolines, and phenazines by clinical isolates of Pseudomonas aeruginosa.

PubMed Central

Smeal, B C; Bender, L; Jungkind, D L; Hastie, A T

1987-01-01

Of 72 clinical isolates of Pseudomonas aeruginosa examined for simultaneous production of secondary metabolites, 86% produced 2-alkyl-4-hydroxyquinolines, 75% produced rhamnolipids, and 58% produced phenazines, including pyocyanin. Whereas isolates producing two or one constituted smaller groups, 39% released all three metabolites. Metabolite production did not appear to influence site of infection. PMID:3112182

Secondary Metabolites from Three Florida Sponges with Antidepressant Activity

PubMed Central

Kochanowska, Anna J.; Rao, Karumanchi V.; Childress, Suzanne; El-Alfy, Abir; Matsumoto, Rae R.; Kelly, Michelle; Stewart, Gina S.; Sufka, Kenneth J.; Hamann, Mark T.

2016-01-01

Brominated indole alkaloids are a common class of metabolites reported from sponges of the order Verongida. Herein we report the isolation, structure determination, and activity of metabolites from three Florida sponges, namely, Verongula rigida (order Verongida, family Aplysinidae), Smenospongia aurea, and S. cerebriformis (order Dictyoceratida, family Thorectidae). All three species were investigated chemically, revealing similarities in secondary metabolites. Brominated compounds, as well as sesquiterpene quinones and hydroquinones, were identified from both V. rigida and S. aurea despite their apparent taxonomic differences at the ordinal level. Similar metabolites found in these distinct sponge species of two different genera provide evidence for a microbial origin of the metabolites. Isolated compounds were evaluated in the Porsolt forced swim test (FST) and the chick anxiety–depression continuum model. Among the isolated compounds, 5,6-dibromo-N,N-dimethyltryptamine (1) exhibited significant antidepressant-like action in the rodent FST model, while 5-bromo-N,N-dimethyltryptamine (2) caused significant reduction of locomotor activity indicative of a potential sedative action. The current study provides ample evidence that marine natural products with the diversity of brominated marine alkaloids will provide potential leads for antidepressant and anxiolytic drugs. PMID:18217716

Identification and Metabolite Profiling of Chemical Activators of Lipid Accumulation in Green Algae.

PubMed

Wase, Nishikant; Tu, Boqiang; Allen, James W; Black, Paul N; DiRusso, Concetta C

2017-08-01

Microalgae are proposed as feedstock organisms useful for producing biofuels and coproducts. However, several limitations must be overcome before algae-based production is economically feasible. Among these is the ability to induce lipid accumulation and storage without affecting biomass yield. To overcome this barrier, a chemical genetics approach was employed in which 43,783 compounds were screened against Chlamydomonas reinhardtii , and 243 compounds were identified that increase triacylglyceride (TAG) accumulation without terminating growth. Identified compounds were classified by structural similarity, and 15 were selected for secondary analyses addressing impacts on growth fitness, photosynthetic pigments, and total cellular protein and starch concentrations. TAG accumulation was verified using gas chromatography-mass spectrometry quantification of total fatty acids, and targeted TAG and galactolipid measurements were performed using liquid chromatography-multiple reaction monitoring/mass spectrometry. These results demonstrated that TAG accumulation does not necessarily proceed at the expense of galactolipid. Untargeted metabolite profiling provided important insights into pathway shifts due to five different compound treatments and verified the anabolic state of the cells with regard to the oxidative pentose phosphate pathway, Calvin cycle, tricarboxylic acid cycle, and amino acid biosynthetic pathways. Metabolite patterns were distinct from nitrogen starvation and other abiotic stresses commonly used to induce oil accumulation in algae. The efficacy of these compounds also was demonstrated in three other algal species. These lipid-inducing compounds offer a valuable set of tools for delving into the biochemical mechanisms of lipid accumulation in algae and a direct means to improve algal oil content independent of the severe growth limitations associated with nutrient deprivation. © 2017 American Society of Plant Biologists. All Rights Reserved.

Nectar chemistry mediates the behavior of parasitized bees: consequences for plant fitness.

PubMed

Richardson, Leif L; Bowers, M Deane; Irwin, Rebecca E

2016-02-01

Plants produce an array of secondary metabolites that play important ecological roles as anti-herbivore and anti-pathogen defenses. Many herbivores experience physiological costs when they consume secondary metabolites, yet some also benefit, for example when these chemicals confer resistance to parasites and predators. Secondary metabolites are often present in nectar and pollen, which is paradoxical given that floral rewards are important in the attraction of mutualists rather than deterrence of antagonists. Motivated by studies of interactions among plants, herbivores, and parasites, as well as research showing that secondary metabolites can reduce bee disease, we characterized the occurrence of two iridoid glycosides, aucubin and catalpol, in floral rewards and other tissues of the bee pollinated plant, Chelone glabra. We then experimentally investigated effects of nectar iridoid glycoside concentrations on the foraging behavior of bumble bee pollinators naturally afflicted by a parasitoid fly and a protozoan intestinal parasite, and subsequent effects on an estimate of plant reproduction. We found that floral nectar had lower iridoid glycoside concentrations than leaves, pollen, and corollas, and that, compared to those plant parts, the relative ratio of the two primary iridoid glycosides, aucubin and catalpol, was reversed in nectar. Whether bees carried parasitoid fly larvae did not affect their response to nectar chemistry; however, there was a significant interaction between protozoan parasite infection and nectar treatment, with infected bees foraging longer at flowers with high compared to low nectar iridoid glycoside concentrations. Parasitized bees were also more likely to return to inflorescences with high iridoid glycoside nectar. Consequently, flowers in the high iridoid glycoside nectar treatment donated significantly more pollen to conspecific stigmas than did flowers in the low iridoid glycoside treatment, suggesting an increase in male plant fitness. Taken together, these results demonstrate that nectar secondary metabolites can mediate the behavior of pollinators with subsequent benefits for estimates of plant reproduction.

Different accumulation profiles of multiple components between pericarp and seed of Alpinia oxyphylla capsular fruit as determined by UFLC-MS/MS.

PubMed

Chen, Feng; Li, Hai-Long; Tan, Yin-Feng; Guan, Wei-Wei; Zhang, Jun-Qing; Li, Yong-Hui; Zhao, Yuan-Sheng; Qin, Zhen-Miao

2014-04-10

Plant secondary metabolites are known to not only play a key role in the adaptation of plants to their environment, but also represent an important source of active pharmaceuticals. Alpinia oxyphylla capsular fruits, made up of seeds and pericarps, are commonly used in traditional East Asian medicines. In clinical utilization of these capsular fruits, inconsistent processing approaches (i.e., hulling pericarps or not) are employed, with the potential of leading to differential pharmacological effects. Therefore, an important question arises whether the content levels of pharmacologically active chemicals between the seeds and pericarps of A. oxyphylla are comparable. Nine secondary metabolites present in A. oxyphylla capsular fruits, including flavonoids (e.g., tectochrysin, izalpinin, chrysin, apigenin-4',7-dimethylether and kaempferide), diarylheptanoids (e.g., yakuchinone A and B and oxyphyllacinol) and sesquiterpenes (e.g., nootkatone), were regarded as representative constituents with putative pharmacological activities. This work aimed to investigate the abundance of the nine constituents in the seeds and pericarps of A. oxyphylla. Thirteen batches of A. oxyphylla capsular fruits were gathered from different production regions. Accordingly, an ultra-fast high performance liquid chromatography/quadrupole tandem mass spectrometry (UFLC-MS/MS) method was developed and validated. We found that: (1) the nine secondary metabolites were differentially concentrated in seeds and fruit capsules; (2) nootkatone is predominantly distributed in the seeds; in contrast, the flavonoids and diarylheptanoids are mainly deposited in the capsules; and (3) the content levels of the nine secondary metabolites occurring in the capsules varied greatly among different production regions, although the nootkatone levels in the seeds were comparable among production regions. These results are helpful to evaluating and elucidating pharmacological activities of A. oxyphylla capsular fruits. Additionally, it may be of interest to elucidate the mechanisms involved in the distinct accumulation profiles of these secondary metabolites between seeds and pericarps.

Cellular Apoptosis of Hemocytes from Dendrolimus tabulaeformis Tsai et Liu Larvae Induced with the Secondary Metabolites of Beauveria brongniartii (Sacc.) Petch

PubMed Central

Fan, Jinhua; Xie, Yingping; Xue, Jiaoliang; Zhang, Yingling; Yang, Qian

2013-01-01

To investigate the effect of the secondary metabolites of entomopathogenic fungus on the hemocyte immunity of host insect, the secondary metabolite complex (SMC) of Beauveria brongniartii was used in three concentrations (5.5, 55, and 550 µg/mL), and the 4th instar larvae of the pine caterpillar Dendrolimus tabulaeformis were employed as host insects. The larvae were inoculated with the SMC solutions by injection in bioassays. Apoptosis of the larval hemocytes was observed using fluorescence microscopy (FM), transmission electron microscopy (TEM), and flow cytometry (FCM). The FM results showed that in the treated groups, larval hemocytes exhibited symptoms of early apoptosis at 6 h post-treatment by radiating a non-uniform kelly fluorescence and exhibited symptoms of late apoptosis at 12 h post-treatment by radiating a non-uniform orange fluorescence. Under TEM, the following ultra-structural changes associated with apoptosis of the larval hemocytes were observed in the treated groups: the nuclei were hypertrophied, slight folds were on the nuclear envelope, the chromatin became concentrated, the mitochondrial cristae disappeared or were disorderly, most cells developed blebs, and fibrillar aggregation appeared and accumulated in the cytoplasm. Apoptosis of the larval hemocytes was detected by FCM at 6 h post-treatment; the percentage of early apoptotic cells in the SMC 5.5, 55, and 550 µg/mL treatment groups were 11.93%, 13.10%, and 18.42%, respectively. Late apoptosis first occurred at 12 h post-treatment; the highest rate of apoptosis was 36.54 ± 4.37% at 24 h post-treatment in the SMC 55 µg/mL treatment group. In general, the cellular apoptosis rate was positively correlated with the SMC concentration and the time post-treatment. These results indicate that secondary metabolites of B . brongniartii are able to attack the hemocytes of D . tabulaeformis larvae and induce cellular apoptosis, thereby providing new evidence that secondary metabolites of mycopathogens can act on host immune systems. PMID:23940771

Upregulation and Identification of Antibiotic Activity of a Marine-Derived Streptomyces sp. via Co-Cultures with Human Pathogens.

PubMed

Sung, Anne A; Gromek, Samantha M; Balunas, Marcy J

2017-08-11

Marine natural product drug discovery has begun to play an important role in the treatment of disease, with several recently approved drugs. In addition, numerous microbial natural products have been discovered from members of the order Actinomycetales, particularly in the genus Streptomyces , due to their metabolic diversity for production of biologically active secondary metabolites. However, many secondary metabolites cannot be produced under laboratory conditions because growth conditions in flask culture differ from conditions in the natural environment. Various experimental conditions (e.g., mixed fermentation) have been attempted to increase yields of previously described metabolites, cause production of previously undetected metabolites, and increase antibiotic activity. Adult ascidians-also known as tunicates-are sessile marine invertebrates, making them vulnerable to predation and therefore are hypothesized to use host-associated bacteria that produce biologically active secondary metabolites for chemical defense. A marine-derived Streptomyces sp. strain PTY087I2 was isolated from a Panamanian tunicate and subsequently co-cultured with human pathogens including Bacillus subtilis , methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant Staphylococcus aureus (MRSA), and Pseudomonas aeruginosa , followed by extraction. Co-culture of Streptomyces sp. PTY087I2 with each of these human pathogens resulted in increased production of three antibiotics: granaticin, granatomycin D, and dihydrogranaticin B, as well as several analogues seen via molecular networking. In addition, co-cultures resulted in strongly enhanced biological activity against the Gram positive human pathogens used in these experiments. Expanded utilization of co-culture experiments to allow for competitive interactions may enhance metabolite production and further our understanding of these microbial interactions.

Anti-dermatophytic activity of marine sponge, Sigmadocia carnosa (Dendy) on clinically isolated fungi.

PubMed

Dhayanithi, N B; Kumar, T T Ajith; Kalaiselvam, M; Balasubramanian, T; Sivakumar, N

2012-08-01

To screen the anti-fungal effects and find out the active metabolites from sponge, Sigmadocia carnosa (S. carnosa) against four dermatophytic fungi. The methanol, ethyl acetate and acetone extract of marine sponge, S. carnosa was examined against Trichophyton mentagrophytes (T. mentagrophytes), Trichophyton rubrum (T. rubrum), Epidermophyton floccosum (E. floccosum) and Microsporum gypseum (M. gypseum) and qualitative analysed to find out the active molecules. The methanol extract of sponge was expressed significant activity than ethyl acetate and acetone. The minimum inhibitory concentration (MIC) of methanol extract of sponge that resulted in complete growth inhibition of T. mentagrophytes, T. rubrum, E. floccosum and M. gypseum were found to 125, 250, 250 and 250 µg/mL respectively. But, 100 % inhibition of fungal spore germination was observed in T. mentagrophytes at 500 µg/mL concentration followed by T. rubrum, E. floccosum and M. gypseum at 1 000 µg/mL concentration. Other two extracts showed weak anti spore germination activity against the tested dermatophytic fungi. Methanol extracts showed presence of terpenoids, steroids, alkaloids, saponins and glycosides. Based on the literature, this is the first study which has conducted to inhibit the growth and spore germination of dermatophytic fungi with S. carnosa. Further research also needs to purify and characterize the secondary metabolites from the sponge, S. carnosa for the valuable source of novel substances for future drug discovery.

Anti-dermatophytic activity of marine sponge, Sigmadocia carnosa (Dendy) on clinically isolated fungi

PubMed Central

Dhayanithi, NB; Kumar, TT Ajith; Kalaiselvam, M; Balasubramanian, T; Sivakumar, N

2012-01-01

Objective To screen the anti-fungal effects and find out the active metabolites from sponge, Sigmadocia carnosa (S. carnosa) against four dermatophytic fungi. Methods The methanol, ethyl acetate and acetone extract of marine sponge, S. carnosa was examined against Trichophyton mentagrophytes (T. mentagrophytes), Trichophyton rubrum (T. rubrum), Epidermophyton floccosum (E. floccosum) and Microsporum gypseum (M. gypseum) and qualitative analysed to find out the active molecules. Results The methanol extract of sponge was expressed significant activity than ethyl acetate and acetone. The minimum inhibitory concentration (MIC) of methanol extract of sponge that resulted in complete growth inhibition of T. mentagrophytes, T. rubrum, E. floccosum and M. gypseum were found to 125, 250, 250 and 250 µg/mL respectively. But, 100 % inhibition of fungal spore germination was observed in T. mentagrophytes at 500 µg/mL concentration followed by T. rubrum, E. floccosum and M. gypseum at 1 000 µg/mL concentration. Other two extracts showed weak anti spore germination activity against the tested dermatophytic fungi. Methanol extracts showed presence of terpenoids, steroids, alkaloids, saponins and glycosides. Conclusion Based on the literature, this is the first study which has conducted to inhibit the growth and spore germination of dermatophytic fungi with S. carnosa. Further research also needs to purify and characterize the secondary metabolites from the sponge, S. carnosa for the valuable source of novel substances for future drug discovery. PMID:23569985

Activation of dormant secondary metabolite production by introducing neomycin resistance into the deep-sea fungus, Aspergillus versicolor ZBY-3.

PubMed

Dong, Yuan; Cui, Cheng-Bin; Li, Chang-Wei; Hua, Wei; Wu, Chang-Jing; Zhu, Tian-Jiao; Gu, Qian-Qun

2014-07-29

A new ultrasound-mediated approach has been developed to introduce neomycin-resistance to activate silent pathways for secondary metabolite production in a bio-inactive, deep-sea fungus, Aspergillus versicolor ZBY-3. Upon treatment of the ZBY-3 spores with a high concentration of neomycin by proper ultrasound irradiation, a total of 30 mutants were obtained by single colony isolation. The acquired resistance of the mutants to neomycin was confirmed by a resistance test. In contrast to the ZBY-3 strain, the EtOAc extracts of 22 of the 30 mutants inhibited the human cancer K562 cells, indicating that these mutants acquired a capability to produce antitumor metabolites. HPLC-photodiode array detector (PDAD)-UV and HPLC-electron spray ionization (ESI)-MS analyses of the EtOAc extracts of seven bioactive mutants and the ZBY-3 strain indicated that diverse secondary metabolites have been newly produced in the mutant extracts in contrast to the ZBY-3 extract. The followed isolation and characterization demonstrated that six metabolites, cyclo(D-Pro-D-Phe) (1), cyclo(D-Tyr-D-Pro) (2), phenethyl 5-oxo-L-prolinate (3), cyclo(L-Ile-L-Pro) (4), cyclo(L-Leu-L-Pro) (5) and 3β,5α,9α-trihydroxy-(22E,24R)-ergosta-7,22-dien-6-one (6), were newly produced by the mutant u2n2h3-3 compared to the parent ZBY-3 strain. Compound 3 was a new compound; 2 was isolated from a natural source for the first time, and all of these compounds were also not yet found in the metabolites of other A. versicolor strains. Compounds 1-6 inhibited the K562 cells, with inhibition rates of 54.6% (1), 72.9% (2), 23.5% (3), 29.6% (4), 30.9% (5) and 51.1% (6) at 100 μg/mL, and inhibited also other human cancer HL-60, BGC-823 and HeLa cells, to some extent. The present study demonstrated the effectiveness of the ultrasound-mediated approach to activate silent metabolite production in fungi by introducing acquired resistance to aminoglycosides and its potential for discovering new compounds from silent fungal metabolic pathways. This approach could be applied to elicit the metabolic potentials of other fungal isolates to discover new compounds from cryptic secondary metabolites.

A Latex Metabolite Benefits Plant Fitness under Root Herbivore Attack.

PubMed

Huber, Meret; Epping, Janina; Schulze Gronover, Christian; Fricke, Julia; Aziz, Zohra; Brillatz, Théo; Swyers, Michael; Köllner, Tobias G; Vogel, Heiko; Hammerbacher, Almuth; Triebwasser-Freese, Daniella; Robert, Christelle A M; Verhoeven, Koen; Preite, Veronica; Gershenzon, Jonathan; Erb, Matthias

2016-01-01

Plants produce large amounts of secondary metabolites in their shoots and roots and store them in specialized secretory structures. Although secondary metabolites and their secretory structures are commonly assumed to have a defensive function, evidence that they benefit plant fitness under herbivore attack is scarce, especially below ground. Here, we tested whether latex secondary metabolites produced by the common dandelion (Taraxacum officinale agg.) decrease the performance of its major native insect root herbivore, the larvae of the common cockchafer (Melolontha melolontha), and benefit plant vegetative and reproductive fitness under M. melolontha attack. Across 17 T. officinale genotypes screened by gas and liquid chromatography, latex concentrations of the sesquiterpene lactone taraxinic acid β-D-glucopyranosyl ester (TA-G) were negatively associated with M. melolontha larval growth. Adding purified TA-G to artificial diet at ecologically relevant concentrations reduced larval feeding. Silencing the germacrene A synthase ToGAS1, an enzyme that was identified to catalyze the first committed step of TA-G biosynthesis, resulted in a 90% reduction of TA-G levels and a pronounced increase in M. melolontha feeding. Transgenic, TA-G-deficient lines were preferred by M. melolontha and suffered three times more root biomass reduction than control lines. In a common garden experiment involving over 2,000 T. officinale individuals belonging to 17 different genotypes, high TA-G concentrations were associated with the maintenance of high vegetative and reproductive fitness under M. melolontha attack. Taken together, our study demonstrates that a latex secondary metabolite benefits plants under herbivore attack, a result that provides a mechanistic framework for root herbivore driven natural selection and evolution of plant defenses below ground.

Antioxidant Enzyme Activities and Secondary Metabolite Profiling of Oil Palm Seedlings Treated with Combination of NPK Fertilizers Infected with Ganoderma boninense.

PubMed

Sahebi, Mahbod; Hanafi, Mohamed M; Mohidin, Hasmah; Rafii, M Y; Azizi, Parisa; Idris, Abu Seman; Fariz, A; Abiri, Rambod; Taheri, Sima; Moradpoor, Mehdi

2018-01-01

Oil palm ( Elaeis guineensis Jacq) is one of the major sources of edible oil. Reducing the effect of Ganoderma, main cause of basal stem rot (BSR) on oil palm, is the main propose of this study. Understanding the oil palm defense mechanism against Ganoderma infection through monitoring changes in the secondary metabolite compounds levels before/after infection by Ganoderma under different fertilizing treatment is required. Oil palm requires macro- and microelements for growth and yield. Manipulating the nutrient for oil palm is a method to control the disease. The 3-4-month-old oil palm seedlings were given different macronutrient treatments to evaluate induction of defense related enzymes and production of secondary metabolite compounds in response to G. boninense inoculation. The observed trend of changes in the infected and uninfected seedlings was a slightly higher activity for β -1,3-glucanases, chitinase, peroxidase, and phenylalanine ammonia-lyase during the process of pathogenesis. It was found that PR proteins gave positive response to the interaction between oil palm seedlings and Ganoderma infection. Although the responses were activated systematically, they were short-lasting as the changes in enzymes activities appeared before the occurrence of visible symptoms. Effect of different nutrients doses was obviously observed among the results of the secondary metabolite compounds. Many identified/unidentified metabolite compounds were presented, of which some were involved in plant cell defense mechanism against pathogens, mostly belonging to alkaloids with bitter-tasting nitrogenous-compounds, and some had the potential to be used as new markers to detect basal stem rot at the initial step of disease.

Accumulation of secondary metabolites in healthy and diseased barley, grown under future climate levels of CO2, ozone and temperature.

PubMed

Mikkelsen, B L; Olsen, C E; Lyngkjær, M F

2015-10-01

Plants produce secondary metabolites promoting adaptation to changes in the environment and challenges by pathogenic microorganisms. A future climate with increased temperature and CO2 and ozone levels will likely alter the chemical composition of plants and thereby plant-pathogen interactions. To investigate this, barley was grown at elevated CO2, temperature and ozone levels as single factors or in combination resembling future climatic conditions. Increased basal resistance to the powdery mildew fungus was observed when barley was grown under elevated CO2, temperature and ozone as single factors. However, this effect was neutralized in the combination treatments. Twenty-five secondary metabolites were putatively identified in healthy and diseased barley leaves, including phenylpropanoids, phenolamides and hydroxynitrile glucosides. Accumulation of the compounds was affected by the climatic growth conditions. Especially elevated temperature, but also ozone, showed a strong impact on accumulation of many compounds, suggesting that these metabolites play a role in adaptation to unfavorable growth conditions. Many compounds were found to increase in powdery mildew diseased leaves, in correlation with a strong and specific influence of the climatic growth conditions. The observed disease phenotypes could not be explained by accumulation of single compounds. However, decreased accumulation of the powdery mildew associated defense compound p-coumaroylhydroxyagmatine could be implicated in the increased disease susceptibility observed when barley was grown under combination of elevated CO2, temperature and ozone. The accumulation pattern of the compounds in both healthy and diseased leaves from barley grown in the combination treatments could not be deduced from the individual single factor treatments. This highlights the complex role and regulation of secondary metabolites in plants' adaptation to unfavorable growth conditions. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Latex Metabolite Benefits Plant Fitness under Root Herbivore Attack

PubMed Central

Huber, Meret; Epping, Janina; Schulze Gronover, Christian; Fricke, Julia; Aziz, Zohra; Brillatz, Théo; Swyers, Michael; Köllner, Tobias G.; Vogel, Heiko; Hammerbacher, Almuth; Triebwasser-Freese, Daniella; Robert, Christelle A. M.; Verhoeven, Koen; Preite, Veronica; Gershenzon, Jonathan; Erb, Matthias

2016-01-01

Plants produce large amounts of secondary metabolites in their shoots and roots and store them in specialized secretory structures. Although secondary metabolites and their secretory structures are commonly assumed to have a defensive function, evidence that they benefit plant fitness under herbivore attack is scarce, especially below ground. Here, we tested whether latex secondary metabolites produced by the common dandelion (Taraxacum officinale agg.) decrease the performance of its major native insect root herbivore, the larvae of the common cockchafer (Melolontha melolontha), and benefit plant vegetative and reproductive fitness under M. melolontha attack. Across 17 T. officinale genotypes screened by gas and liquid chromatography, latex concentrations of the sesquiterpene lactone taraxinic acid β-D-glucopyranosyl ester (TA-G) were negatively associated with M. melolontha larval growth. Adding purified TA-G to artificial diet at ecologically relevant concentrations reduced larval feeding. Silencing the germacrene A synthase ToGAS1, an enzyme that was identified to catalyze the first committed step of TA-G biosynthesis, resulted in a 90% reduction of TA-G levels and a pronounced increase in M. melolontha feeding. Transgenic, TA-G-deficient lines were preferred by M. melolontha and suffered three times more root biomass reduction than control lines. In a common garden experiment involving over 2,000 T. officinale individuals belonging to 17 different genotypes, high TA-G concentrations were associated with the maintenance of high vegetative and reproductive fitness under M. melolontha attack. Taken together, our study demonstrates that a latex secondary metabolite benefits plants under herbivore attack, a result that provides a mechanistic framework for root herbivore driven natural selection and evolution of plant defenses below ground. PMID:26731567

The Genome of Tolypocladium inflatum: Evolution, Organization, and Expression of the Cyclosporin Biosynthetic Gene Cluster

PubMed Central

Bushley, Kathryn E.; Raja, Rajani; Jaiswal, Pankaj; Cumbie, Jason S.; Nonogaki, Mariko; Boyd, Alexander E.; Owensby, C. Alisha; Knaus, Brian J.; Elser, Justin; Miller, Daniel; Di, Yanming; McPhail, Kerry L.; Spatafora, Joseph W.

2013-01-01

The ascomycete fungus Tolypocladium inflatum, a pathogen of beetle larvae, is best known as the producer of the immunosuppressant drug cyclosporin. The draft genome of T. inflatum strain NRRL 8044 (ATCC 34921), the isolate from which cyclosporin was first isolated, is presented along with comparative analyses of the biosynthesis of cyclosporin and other secondary metabolites in T. inflatum and related taxa. Phylogenomic analyses reveal previously undetected and complex patterns of homology between the nonribosomal peptide synthetase (NRPS) that encodes for cyclosporin synthetase (simA) and those of other secondary metabolites with activities against insects (e.g., beauvericin, destruxins, etc.), and demonstrate the roles of module duplication and gene fusion in diversification of NRPSs. The secondary metabolite gene cluster responsible for cyclosporin biosynthesis is described. In addition to genes necessary for cyclosporin biosynthesis, it harbors a gene for a cyclophilin, which is a member of a family of immunophilins known to bind cyclosporin. Comparative analyses support a lineage specific origin of the cyclosporin gene cluster rather than horizontal gene transfer from bacteria or other fungi. RNA-Seq transcriptome analyses in a cyclosporin-inducing medium delineate the boundaries of the cyclosporin cluster and reveal high levels of expression of the gene cluster cyclophilin. In medium containing insect hemolymph, weaker but significant upregulation of several genes within the cyclosporin cluster, including the highly expressed cyclophilin gene, was observed. T. inflatum also represents the first reference draft genome of Ophiocordycipitaceae, a third family of insect pathogenic fungi within the fungal order Hypocreales, and supports parallel and qualitatively distinct radiations of insect pathogens. The T. inflatum genome provides additional insight into the evolution and biosynthesis of cyclosporin and lays a foundation for further investigations of the role of secondary metabolite gene clusters and their metabolites in fungal biology. PMID:23818858

Antioxidant Enzyme Activities and Secondary Metabolite Profiling of Oil Palm Seedlings Treated with Combination of NPK Fertilizers Infected with Ganoderma boninense

PubMed Central

Mohidin, Hasmah; Idris, Abu Seman; Fariz, A.; Abiri, Rambod; Taheri, Sima; Moradpoor, Mehdi

2018-01-01

Oil palm (Elaeis guineensis Jacq) is one of the major sources of edible oil. Reducing the effect of Ganoderma, main cause of basal stem rot (BSR) on oil palm, is the main propose of this study. Understanding the oil palm defense mechanism against Ganoderma infection through monitoring changes in the secondary metabolite compounds levels before/after infection by Ganoderma under different fertilizing treatment is required. Oil palm requires macro- and microelements for growth and yield. Manipulating the nutrient for oil palm is a method to control the disease. The 3-4-month-old oil palm seedlings were given different macronutrient treatments to evaluate induction of defense related enzymes and production of secondary metabolite compounds in response to G. boninense inoculation. The observed trend of changes in the infected and uninfected seedlings was a slightly higher activity for β-1,3-glucanases, chitinase, peroxidase, and phenylalanine ammonia-lyase during the process of pathogenesis. It was found that PR proteins gave positive response to the interaction between oil palm seedlings and Ganoderma infection. Although the responses were activated systematically, they were short-lasting as the changes in enzymes activities appeared before the occurrence of visible symptoms. Effect of different nutrients doses was obviously observed among the results of the secondary metabolite compounds. Many identified/unidentified metabolite compounds were presented, of which some were involved in plant cell defense mechanism against pathogens, mostly belonging to alkaloids with bitter-tasting nitrogenous-compounds, and some had the potential to be used as new markers to detect basal stem rot at the initial step of disease. PMID:29721500

Broad spectrum antibiotic compounds and use thereof

DOEpatents

Koglin, Alexander; Strieker, Matthias

2016-07-05

The discovery of a non-ribosomal peptide synthetase (NRPS) gene cluster in the genome of Clostridium thermocellum that produces a secondary metabolite that is assembled outside of the host membrane is described. Also described is the identification of homologous NRPS gene clusters from several additional microorganisms. The secondary metabolites produced by the NRPS gene clusters exhibit broad spectrum antibiotic activity. Thus, antibiotic compounds produced by the NRPS gene clusters, and analogs thereof, their use for inhibiting bacterial growth, and methods of making the antibiotic compounds are described.

Distribution and Catabolic Diversity of 3-Chlorobenzoic Acid Degrading Bacteria Isolated from Geographically-Separated Pristine Soils

DTIC Science & Technology

1994-08-01

influence on the structure of 3-CBA degrading populations. This suggests that if substrate exposure is important, secondary metabolites produced during the...enrichments were treated with 50 gIg 3-CBAgodry-soil- 1 and secondary enrichments were performed with 50 p.g 3-CBA ml-1 d•tfined medium. Isolates were...not attempt to determine metabolites or if transformations were biologically mediated. As a result, it was not clear whether disappearance of a

Cytotoxicity of trichothecenes and fusarochromanone produced by Fusarium equiseti strains isolated from Norwegian cereals.

PubMed

Morrison, Ellen; Rundberget, Thomas; Kosiak, Barbara; Aastveit, Are H; Bernhoft, Aksel

2002-01-01

The cytotoxicity and secondary metabolites of 28 Norwegian strains of Fusarium equiseti have been characterized. Trichothecenes and fusarochromanone (FUCH) in rice culture extracts of the strains were analysed by gas chromatography-mass spectrometry (GC-MS) and high performance liquid chromatography (HPLC). The following metabolites were found in all isolates: FUCH, nivalenol (NIV), scirpentriol (SCIRP), 4-acetylnivalenol (4-ac-NIV, also called fusarenon-X), 15-acetyl-nivalenol (15-ac-NIV), and diacetoxyscirpenol (DAS). 4,15-diacetyl-nivalenol (diacetyl-NIV) was found in 5 isolates. Porcine kidney epithelial cells (PK15. American Type Culture Collection) were exposed to rice culture extracts to study cytotoxicity. Descriptive statistics and factor analysis of the identified secondary metabolites show that their main metabolites were FUCH, NIV, SCIRP, DAS and 15-ac-NIV, consecutively. The individual trichothecenes were highly intercorrelated, whereas the production of acetylated NIV and DAS was slightly less. Stepwise multiple regression analysis of cytotoxicity and metabolite profiles of rice culture extracts ascribed the toxicity mainly to a combination of FUCH and 15-ac-NIV, though SCIRP or DAS are agents in the combined toxicity as well.

Advances in the understanding and use of the genomic base of microbial secondary metabolite biosynthesis for the discovery of new natural products.

PubMed

McAlpine, James B

2009-03-27

Over the past decade major changes have occurred in the access to genome sequences that encode the enzymes responsible for the biosynthesis of secondary metabolites, knowledge of how those sequences translate into the final structure of the metabolite, and the ability to alter the sequence to obtain predicted products via both homologous and heterologous expression. Novel genera have been discovered leading to new chemotypes, but more surprisingly several instances have been uncovered where the apparently general rules of modular translation have not applied. Several new biosynthetic pathways have been unearthed, and our general knowledge grows rapidly. This review aims to highlight some of the more striking discoveries and advances of the decade.

Multi-Capillary Column-Ion Mobility Spectrometry of Volatile Metabolites Emitted by Saccharomyces Cerevisiae

PubMed Central

Halbfeld, Christoph; Ebert, Birgitta E.; Blank, Lars M.

2014-01-01

Volatile organic compounds (VOCs) produced during microbial fermentations determine the flavor of fermented food and are of interest for the production of fragrances or food additives. However, the microbial synthesis of these compounds from simple carbon sources has not been well investigated so far. Here, we analyzed the headspace over glucose minimal salt medium cultures of Saccharomyces cerevisiae using multi-capillary column-ion mobility spectrometry (MCC-IMS). The high sensitivity and fast data acquisition of the MCC-IMS enabled online analysis of the fermentation off-gas and 19 specific signals were determined. To four of these volatile compounds, we could assign the metabolites ethanol, 2-pentanone, isobutyric acid, and 2,3-hexanedione by MCC-IMS measurements of pure standards and cross validation with thermal desorption–gas chromatography-mass spectrometry measurements. Despite the huge biochemical knowledge of the biochemistry of the model organism S. cerevisiae, only the biosynthetic pathways for ethanol and isobutyric acid are fully understood, demonstrating the considerable lack of research of volatile metabolites. As monitoring of VOCs produced during microbial fermentations can give valuable insight into the metabolic state of the organism, fast and non-invasive MCC-IMS analyses provide valuable data for process control. PMID:25197771

Exploiting members of the BAHD acyltransferase family to synthesize multiple hydroxycinnamate and benzoate conjugates in yeast

DOE PAGES

Eudes, Aymerick; Mouille, Maxence; Robinson, David S.; ...

2016-11-21

BAHD acyltransferases, named after the first four biochemically characterized enzymes of the group, are plant-specific enzymes that catalyze the transfer of coenzyme A-activated donors onto various acceptor molecules. They are responsible for the synthesis in plants of a myriad of secondary metabolites, some of which are beneficial for humans either as therapeutics or as specialty chemicals such as flavors and fragrances. The production of pharmaceutical, nutraceutical and commodity chemicals using engineered microbes is an alternative, green route to energy-intensive chemical syntheses that consume petroleum-based precursors. However, identification of appropriate enzymes and validation of their functional expression in heterologous hosts ismore » a prerequisite for the design and implementation of metabolic pathways in microbes for the synthesis of such target chemicals. As a result, for the synthesis of valuable metabolites in the yeast Saccharomyces cerevisiae, we selected BAHD acyltransferases based on their preferred donor and acceptor substrates. In particular, BAHDs that use hydroxycinnamoyl-CoAs and/or benzoyl-CoA as donors were targeted because a large number of molecules beneficial to humans belong to this family of hydroxycinnamate and benzoate conjugates. The selected BAHD coding sequences were synthesized and cloned individually on a vector containing the Arabidopsis gene At4CL5, which encodes a promiscuous 4-coumarate:CoA ligase active on hydroxycinnamates and benzoates. The various S. cerevisiae strains obtained for co-expression of At4CL5 with the different BAHDs effectively produced a wide array of valuable hydroxycinnamate and benzoate conjugates upon addition of adequate combinations of donors and acceptor molecules. In particular, we report here for the first time the production in yeast of rosmarinic acid and its derivatives, quinate hydroxycinnamate esters such as chlorogenic acid, and glycerol hydroxycinnamate esters. Similarly, we achieved for the first time the microbial production of polyamine hydroxycinnamate amides; monolignol, malate and fatty alcohol hydroxycinnamate esters; tropane alkaloids; and benzoate/caffeate alcohol esters. In some instances, the additional expression of Flavobacterium johnsoniae tyrosine ammonia-lyase (FjTAL) allowed the synthesis of p-coumarate conjugates and eliminated the need to supplement the culture media with 4-hydroxycinnamate. In conclusion, we demonstrate in this study the effectiveness of expressing members of the plant BAHD acyltransferase family in yeast for the synthesis of numerous valuable hydroxycinnamate and benzoate conjugates.« less

Exploiting members of the BAHD acyltransferase family to synthesize multiple hydroxycinnamate and benzoate conjugates in yeast

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eudes, Aymerick; Mouille, Maxence; Robinson, David S.

BAHD acyltransferases, named after the first four biochemically characterized enzymes of the group, are plant-specific enzymes that catalyze the transfer of coenzyme A-activated donors onto various acceptor molecules. They are responsible for the synthesis in plants of a myriad of secondary metabolites, some of which are beneficial for humans either as therapeutics or as specialty chemicals such as flavors and fragrances. The production of pharmaceutical, nutraceutical and commodity chemicals using engineered microbes is an alternative, green route to energy-intensive chemical syntheses that consume petroleum-based precursors. However, identification of appropriate enzymes and validation of their functional expression in heterologous hosts ismore » a prerequisite for the design and implementation of metabolic pathways in microbes for the synthesis of such target chemicals. As a result, for the synthesis of valuable metabolites in the yeast Saccharomyces cerevisiae, we selected BAHD acyltransferases based on their preferred donor and acceptor substrates. In particular, BAHDs that use hydroxycinnamoyl-CoAs and/or benzoyl-CoA as donors were targeted because a large number of molecules beneficial to humans belong to this family of hydroxycinnamate and benzoate conjugates. The selected BAHD coding sequences were synthesized and cloned individually on a vector containing the Arabidopsis gene At4CL5, which encodes a promiscuous 4-coumarate:CoA ligase active on hydroxycinnamates and benzoates. The various S. cerevisiae strains obtained for co-expression of At4CL5 with the different BAHDs effectively produced a wide array of valuable hydroxycinnamate and benzoate conjugates upon addition of adequate combinations of donors and acceptor molecules. In particular, we report here for the first time the production in yeast of rosmarinic acid and its derivatives, quinate hydroxycinnamate esters such as chlorogenic acid, and glycerol hydroxycinnamate esters. Similarly, we achieved for the first time the microbial production of polyamine hydroxycinnamate amides; monolignol, malate and fatty alcohol hydroxycinnamate esters; tropane alkaloids; and benzoate/caffeate alcohol esters. In some instances, the additional expression of Flavobacterium johnsoniae tyrosine ammonia-lyase (FjTAL) allowed the synthesis of p-coumarate conjugates and eliminated the need to supplement the culture media with 4-hydroxycinnamate. In conclusion, we demonstrate in this study the effectiveness of expressing members of the plant BAHD acyltransferase family in yeast for the synthesis of numerous valuable hydroxycinnamate and benzoate conjugates.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eudes, Aymerick; Mouille, Maxence; Robinson, David S.

BAHD acyltransferases, named after the first four biochemically characterized enzymes of the group, are plant-specific enzymes that catalyze the transfer of coenzyme A-activated donors onto various acceptor molecules. They are responsible for the synthesis in plants of a myriad of secondary metabolites, some of which are beneficial for humans either as therapeutics or as specialty chemicals such as flavors and fragrances. The production of pharmaceutical, nutraceutical and commodity chemicals using engineered microbes is an alternative, green route to energy-intensive chemical syntheses that consume petroleum-based precursors. However, identification of appropriate enzymes and validation of their functional expression in heterologous hosts ismore » a prerequisite for the design and implementation of metabolic pathways in microbes for the synthesis of such target chemicals. As a result, for the synthesis of valuable metabolites in the yeast Saccharomyces cerevisiae, we selected BAHD acyltransferases based on their preferred donor and acceptor substrates. In particular, BAHDs that use hydroxycinnamoyl-CoAs and/or benzoyl-CoA as donors were targeted because a large number of molecules beneficial to humans belong to this family of hydroxycinnamate and benzoate conjugates. The selected BAHD coding sequences were synthesized and cloned individually on a vector containing the Arabidopsis gene At4CL5, which encodes a promiscuous 4-coumarate:CoA ligase active on hydroxycinnamates and benzoates. The various S. cerevisiae strains obtained for co-expression of At4CL5 with the different BAHDs effectively produced a wide array of valuable hydroxycinnamate and benzoate conjugates upon addition of adequate combinations of donors and acceptor molecules. In particular, we report here for the first time the production in yeast of rosmarinic acid and its derivatives, quinate hydroxycinnamate esters such as chlorogenic acid, and glycerol hydroxycinnamate esters. Similarly, we achieved for the first time the microbial production of polyamine hydroxycinnamate amides; monolignol, malate and fatty alcohol hydroxycinnamate esters; tropane alkaloids; and benzoate/caffeate alcohol esters. In some instances, the additional expression of Flavobacterium johnsoniae tyrosine ammonia-lyase (FjTAL) allowed the synthesis of p-coumarate conjugates and eliminated the need to supplement the culture media with 4-hydroxycinnamate. In conclusion, we demonstrate in this study the effectiveness of expressing members of the plant BAHD acyltransferase family in yeast for the synthesis of numerous valuable hydroxycinnamate and benzoate conjugates.« less

Partitioning of 14C-labeled photosynthate to allelochemicals and primary metabolites in source and sink leaves of aspen: evidence for secondary metabolite turnover

Treesearch

Karl W. Kleiner; Kenneth F. Raffa; Richard E. Dickson

1999-01-01

Theories on allelochemical concentrations in plants are often based upon the relative carbon costs and benefits of multiple metabolic fractions. Tests of these theories often rely on measuring metabolite concentrations, but frequently overlook priorities in carbon partitioning. We conducted a pulse-labeling experiment to follow the partitioning of 14...

Expression of a maize Myb transcription factor driven by a putative silk-specific promoter significantly enhances resistance to Helicoverpa zea in transgenic maize.

PubMed

Johnson, Eric T; Berhow, Mark A; Dowd, Patrick F

2007-04-18

Hi II maize (Zea mays) plants were engineered to express maize p1 cDNA, a Myb transcription factor, controlled by a putative silk specific promoter, for secondary metabolite production and corn earworm resistance. Transgene expression did not enhance silk color, but about half of the transformed plant silks displayed browning when cut, which indicated the presence of p1-produced secondary metabolites. Levels of maysin, a secondary metabolite with insect toxicity, were highest in newly emerged browning silks. The insect resistance of transgenic silks was also highest at emergence, regardless of maysin levels, which suggests that other unidentified p1-induced molecules likely contributed to larval mortality. Mean survivor weights of corn earworm larvae fed mature browning transgenic silks were significantly lower than weights of those fed mature nonbrowning transgenic silks. Some transgenic pericarps browned with drying and contained similar molecules found in pericarps expressing a dominant p1 allele, suggesting that the promoter may not be silk-specific.

A below-ground herbivore shapes root defensive chemistry in natural plant populations.

PubMed

Huber, Meret; Bont, Zoe; Fricke, Julia; Brillatz, Théo; Aziz, Zohra; Gershenzon, Jonathan; Erb, Matthias

2016-03-30

Plants display extensive intraspecific variation in secondary metabolites. However, the selective forces shaping this diversity remain often unknown, especially below ground. Using Taraxacum officinale and its major native insect root herbivore Melolontha melolontha, we tested whether below-ground herbivores drive intraspecific variation in root secondary metabolites. We found that high M. melolontha infestation levels over recent decades are associated with high concentrations of major root latex secondary metabolites across 21 central European T. officinale field populations. By cultivating offspring of these populations, we show that both heritable variation and phenotypic plasticity contribute to the observed differences. Furthermore, we demonstrate that the production of the sesquiterpene lactone taraxinic acid β-D-glucopyranosyl ester (TA-G) is costly in the absence, but beneficial in the presence of M. melolontha, resulting in divergent selection of TA-G. Our results highlight the role of soil-dwelling insects for the evolution of plant defences in nature. © 2016 The Author(s).

Co-cultivation of Sorangium cellulosum strains affects cellular growth and biosynthesis of secondary metabolite epothilones.

PubMed

Li, Peng-fei; Li, Shu-guang; Li, Zhi-feng; Zhao, Lin; Wang, Ting; Pan, Hong-wei; Liu, Hong; Wu, Zhi-hong; Li, Yue-zhong

2013-08-01

Sorangium cellulosum, a cellulolytic myxobacterium, is capable of producing a variety of bioactive secondary metabolites. Epothilones are anti-eukaryotic secondary metabolites produced by some S. cellulosum strains. In this study, we analyzed interactions between 12 strains of S. cellulosum consisting of epothilone-producers and non-epothilone producers isolated from two distinct soil habitats. Co-cultivation on filter papers showed that different Sorangium strains inhibited one another's growth, whereas epothilone production by the producing strains changed markedly for most (73%) pairwise mixtures. Using a quantitative polymerase chain reaction, we demonstrated that the expression of epothilone biosynthetic genes in the epothilone producers typically changed significantly when these bacteria were mixed with non-producing strains. The results indicated that intraspecies interactions between different S. cellulosum strains not only inhibited the growth of partners, but also could change epothilone production. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Function and application of a non-ester-hydrolyzing carboxylesterase discovered in tulip.

PubMed

Nomura, Taiji

2017-01-01

Plants have evolved secondary metabolite biosynthetic pathways of immense rich diversity. The genes encoding enzymes for secondary metabolite biosynthesis have evolved through gene duplication followed by neofunctionalization, thereby generating functional diversity. Emerging evidence demonstrates that some of those enzymes catalyze reactions entirely different from those usually catalyzed by other members of the same family; e.g. transacylation catalyzed by an enzyme similar to a hydrolytic enzyme. Tuliposide-converting enzyme (TCE), which we recently discovered from tulip, catalyzes the conversion of major defensive secondary metabolites, tuliposides, to antimicrobial tulipalins. The TCEs belong to the carboxylesterase family in the α/β-hydrolase fold superfamily, and specifically catalyze intramolecular transesterification, but not hydrolysis. This non-ester-hydrolyzing carboxylesterase is an example of an enzyme showing catalytic properties that are unpredictable from its primary structure. This review describes the biochemical and physiological aspects of tulipalin biogenesis, and the diverse functions of plant carboxylesterases in the α/β-hydrolase fold superfamily.

Production of microbial secondary metabolites: regulation by the carbon source.

PubMed

Ruiz, Beatriz; Chávez, Adán; Forero, Angela; García-Huante, Yolanda; Romero, Alba; Sánchez, Mauricio; Rocha, Diana; Sánchez, Brenda; Rodríguez-Sanoja, Romina; Sánchez, Sergio; Langley, Elizabeth

2010-05-01

Microbial secondary metabolites are low molecular mass products, not essential for growth of the producing cultures, but very important for human health. They include antibiotics, antitumor agents, cholesterol-lowering drugs, and others. They have unusual structures and are usually formed during the late growth phase of the producing microorganisms. Its synthesis can be influenced greatly by manipulating the type and concentration of the nutrients formulating the culture media. Among these nutrients, the effect of the carbon sources has been the subject of continuous studies for both, industry and research groups. Different mechanisms have been described in bacteria and fungi to explain the negative carbon catabolite effects on secondary metabolite production. Their knowledge and manipulation have been useful either for setting fermentation conditions or for strain improvement. During the last years, important advances have been reported on these mechanisms at the biochemical and molecular levels. The aim of the present review is to describe these advances, giving special emphasis to those reported for the genus Streptomyces.

Uncultured microorganisms as a source of secondary metabolites.

PubMed

Lewis, Kim; Epstein, Slava; D'Onofrio, Anthony; Ling, Losee L

2010-08-01

The vast majority of microbial species are 'uncultured' and do not grow under laboratory conditions. This has led to the development of a number of methods to culture these organisms in a simulated natural environment. Approaches include placing cells in chambers that allow diffusion of compounds from the natural environment, traps enclosed with porous membranes that specifically capture organisms forming hyphae--actinobacteria and microfungi, and growth in the presence of cultivable helper species. Repeated cultivation in situ produces domesticated variants that can grow on regular media in vitro, and can be scaled up for secondary metabolite production. The co-culture approach has led to the identification of the first class of growth factors for uncultured bacteria, iron-chelating siderophores. It appears that many uncultured organisms from diverse taxonomical groups have lost the ability to produce siderophores, and depend on neighboring species for growth. The new cultivation approaches allow for the exploitation of the secondary metabolite potential of the previously inaccessible microorganisms.

Microbial expression of alkaloid biosynthetic enzymes for characterization of their properties.

PubMed

Minami, Hiromichi; Ikezawa, Nobuhiro; Sato, Fumihiko

2010-01-01

A wide variety of secondary metabolites are produced in higher plants. These metabolites are synthesized in specific organs/cells at certain developmental stages and/or under specific environmental conditions. Since these biosynthetic activities are rather restricted and difficult to detect, the biochemical characterization of biosynthetic enzymes involved in secondary metabolism has been limited compared to those involved in primary metabolism. Recently, however, progress in tissue culture and molecular biology has made it easier to study biosynthetic enzymes. Here we describe protocols for expressing some biosynthetic enzymes in Escherichia coli expression systems, since this system is both efficient and cost-effective. First, we describe a standard system for expressing biosynthetic enzymes as a soluble protein under the T7 promoter of the pET expression system in E. coli. In addition, the successful expression of cytochrome P450 in E. coli in an active soluble form with N-terminal modification is discussed, since P450 is the critical enzyme in secondary metabolite biosynthesis.

Plant Phenols as Antibiotic Boosters: In Vitro Interaction of Olive Leaf Phenols with Ampicillin.

PubMed

Lim, Anxy; Subhan, Nusrat; Jazayeri, Jalal A; John, George; Vanniasinkam, Thiru; Obied, Hassan K

2016-03-01

The antimicrobial properties of olive leaf extract (OLE) have been well recognized in the Mediterranean traditional medicine. Few studies have investigated the antimicrobial properties of OLE. In this preliminary study, commercial OLE and its major phenolic secondary metabolites were evaluated in vitro for their antimicrobial activities against Escherichia coli and Staphylococcus aureus, both individually and in combination with ampicillin. Besides luteolin 7-O-glucoside, OLE and its major phenolic secondary metabolites were effective against both bacteria, with more activity on S. aureus. In combination with ampicillin, OLE, caffeic acid, verbascoside and oleuropein showed additive effects. Synergistic interaction was observed between ampicillin and hydroxytyrosol. The phenolic composition of OLE and the stability of olive phenols in assay medium were also investigated. While OLE and its phenolic secondary metabolites may not be potent enough as stand-alone antimicrobials, their abilities to boost the activity of co-administered antibiotics constitute an imperative future research area. Copyright © 2016 John Wiley & Sons, Ltd.

[Isolation and structural elucidation of secondary metabolites from marine Streptomyces sp. SCSIO 1934].

PubMed

Niu, Siwen; Li, Sumei; Tian, Xinpeng; Hu, Tao; Ju, Jianhua; Ynag, Xiaohong; Zhang, Si; Zhang, Changsheng

2011-07-01

Marine Actinobacteria are emerging as new resources for bioactive natural products with promise in novel drug discovery. In recent years, the richness and diversity of marine Actinobacteria from the South China Sea and their ability in producing bioactive products have been investigated. The objective of this work is to isolate and identify bioactive secondary metabolites from a marine actinobacterium SCSIO 1934 derived from sediments of South China Sea. The strain was identified as a Streptomyces spieces by analyzing its 16S rDNA sequence. Streptomyces sp. SCSIO 1934 was fermented under optimized conditions and seven bioactive secondary metabolites were isolated and purified by chromatographic methods including colum chromatography over silica gel and Sephadex LH-20. Their structures were elucidated as 17-O-demethylgeldanamycin (1), lebstatin (2), 17-O-demethyllebstatin (3), nigericin (4), nigericin sodium salt (5), abierixin (6), respectively, by detailed NMR spectroscopic data (1H, 13C, COSY, HSQC and HMBC). This work provided a new marine actinobacterium Streptomyces sp. SCSIO 1934, capable of producing diverse bioactive natural products.

Chemical diversity and pharmacological significance of the secondary metabolites of nutmeg (Myristica fragrans Houtt.)

PubMed Central

Abourashed, Ehab A.; El-Alfy, Abir T.

2016-01-01

Nutmeg is a valued kitchen spice that has been used for centuries all over the world. In addition to its use in flavoring foods and beverages, nutmeg has been used in traditional remedies for stomach and kidney disorders. The antioxidant, antimicrobial and central nervous system effects of nutmeg have also been reported in literature. Nutmeg is a rich source of fixed and essential oil, triterpenes, and various types of phenolic compounds. Many of the secondary metabolites of nutmeg exhibit biological activities that may support its use in traditional medicine. This article provides an overview of the chemistry of secondary metabolites isolated from nutmeg kernel and mace including common methods for analysis of extracts and pure compounds as well as recent approaches towards total synthesis of some of the major constituents. A summary of the most significant pharmacological investigations of potential drug leads isolated from nutmeg and reported in the last decade is also included. PMID:28082856

Medicinal plants: a source of anti-parasitic secondary metabolites.

PubMed

Wink, Michael

2012-10-31

This review summarizes human infections caused by endoparasites, including protozoa, nematodes, trematodes, and cestodes, which affect more than 30% of the human population, and medicinal plants of potential use in their treatment. Because vaccinations do not work in most instances and the parasites have sometimes become resistant to the available synthetic therapeutics, it is important to search for alternative sources of anti-parasitic drugs. Plants produce a high diversity of secondary metabolites with interesting biological activities, such as cytotoxic, anti-parasitic and anti-microbial properties. These drugs often interfere with central targets in parasites, such as DNA (intercalation, alkylation), membrane integrity, microtubules and neuronal signal transduction. Plant extracts and isolated secondary metabolites which can inhibit protozoan parasites, such as Plasmodium, Trypanosoma, Leishmania, Trichomonas and intestinal worms are discussed. The identified plants and compounds offer a chance to develop new drugs against parasitic diseases. Most of them need to be tested in more detail, especially in animal models and if successful, in clinical trials.

Comprehensive separation of secondary metabolites in natural products by high-speed counter-current chromatography using a three-phase solvent system.

PubMed

Yanagida, Akio; Yamakawa, Yutaka; Noji, Ryoko; Oda, Ako; Shindo, Heisaburo; Ito, Yoichiro; Shibusawa, Yoichi

2007-06-01

High-speed counter-current chromatography (HSCCC) using the three-phase solvent system n-hexane-methyl acetate-acetonitrile-water at a volume ratio of 4:4:3:4 was applied to the comprehensive separation of secondary metabolites in several natural product extracts. A wide variety of secondary metabolites in each natural product was effectively extracted with the three-phase solvent system, and the filtered extract was directly submitted to the HSCCC separation using the same three-phase system. In the HSCCC profiles of crude natural drugs listed in the Japanese Pharmacopoeia, several physiologically active compounds were clearly separated from other components in the extracts. The HSCCC profiles of several tea products, each manufactured by a different process, clearly showed their compositional difference in main compounds such as catechins, caffeine, and pigments. These HSCCC profiles also provide useful information about hydrophobic diversity of whole components present in each natural product.

Secondary metabolism and interspecific competition affect accumulation of spontaneous mutants in the GacS-GacA regulatory system in Pseudomonas protegens

USDA-ARS?s Scientific Manuscript database

Secondary metabolites are synthesized by many microorganisms and provide a fitness benefit in the presence of competitors and predators. Secondary metabolism also can be costly, as it shunts energy and intermediates from primary metabolism. In Pseudomonas spp., secondary metabolism is controlled by ...

Genomic and transcriptomic analysis of the endophytic fungus Pestalotiopsis fici reveals its lifestyle and high potential for synthesis of natural products.

PubMed

Wang, Xiuna; Zhang, Xiaoling; Liu, Ling; Xiang, Meichun; Wang, Wenzhao; Sun, Xiang; Che, Yongsheng; Guo, Liangdong; Liu, Gang; Guo, Liyun; Wang, Chengshu; Yin, Wen-Bing; Stadler, Marc; Zhang, Xinyu; Liu, Xingzhong

2015-01-27

In recent years, the genus Pestalotiopsis is receiving increasing attention, not only because of its economic impact as a plant pathogen but also as a commonly isolated endophyte which is an important source of bioactive natural products. Pestalotiopsis fici Steyaert W106-1/CGMCC3.15140 as an endophyte of tea produces numerous novel secondary metabolites, including chloropupukeananin, a derivative of chlorinated pupukeanane that is first discovered in fungi. Some of them might be important as the drug leads for future pharmaceutics. Here, we report the genome sequence of the endophytic fungus of tea Pestalotiopsis fici W106-1/CGMCC3.15140. The abundant carbohydrate-active enzymes especially significantly expanding pectinases allow the fungus to utilize the limited intercellular nutrients within the host plants, suggesting adaptation of the fungus to endophytic lifestyle. The P. fici genome encodes a rich set of secondary metabolite synthesis genes, including 27 polyketide synthases (PKSs), 12 non-ribosomal peptide synthases (NRPSs), five dimethylallyl tryptophan synthases, four putative PKS-like enzymes, 15 putative NRPS-like enzymes, 15 terpenoid synthases, seven terpenoid cyclases, seven fatty-acid synthases, and five hybrids of PKS-NRPS. The majority of these core enzymes distributed into 74 secondary metabolite clusters. The putative Diels-Alderase genes have undergone expansion. The significant expansion of pectinase encoding genes provides essential insight in the life strategy of endophytes, and richness of gene clusters for secondary metabolites reveals high potential of natural products of endophytic fungi.

Structure and Absolute Configuration of Jurassic Polyketide-Derived Spiroborate Pigments Obtained from Microgram Quantities.

PubMed

Wolkenstein, Klaus; Sun, Han; Falk, Heinz; Griesinger, Christian

2015-10-28

Complete structural elucidation of natural products is often challenging due to structural complexity and limited availability. This is true for present-day secondary metabolites, but even more for exceptionally preserved secondary metabolites of ancient organisms that potentially provide insights into the evolutionary history of natural products. Here, we report the full structure and absolute configuration of the borolithochromes, enigmatic boron-containing pigments from a Jurassic putative red alga, from samples of less than 50 μg using microcryoprobe NMR, circular dichroism spectroscopy, and density functional theory calculations and reveal their polyketide origin. The pigments are identified as spiroborates with two pentacyclic sec-butyl-trihydroxy-methyl-benzo[gh]tetraphen-one ligands and less-substituted derivatives. The configuration of the sec-butyl group is found to be (S). Because the exceptional benzo[gh]tetraphene scaffold is otherwise only observed in the recently discovered polyketide clostrubin from a present-day Clostridium bacterium, the Jurassic borolithochromes now can be unambiguously linked to the modern polyketide, providing evidence that the fossil pigments are almost originally preserved secondary metabolites and suggesting that the pigments in fact may have been produced by an ancient bacterium. The borolithochromes differ fundamentally from previously described boronated polyketides and represent the first boronated aromatic polyketides found so far. Our results demonstrate the potential of microcryoprobe NMR in the analysis of previously little-explored secondary metabolites from ancient organisms and reveal the evolutionary significance of clostrubin-type polyketides.

Qualitative and quantitative characterization of secondary metabolites and carbohydrates in Bai-Hu-Tang using ultraperformance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry and ultraperformance liquid chromatography coupled with photodiode array detector.

PubMed

Zhong, Wei-Fang; Tong, Wing-Sum; Zhou, Shan-Shan; Yip, Ka-Man; Li, Song-Lin; Zhao, Zhong-Zhen; Xu, Jun; Chen, Hu-Biao

2017-10-01

Bai-Hu-Tang (BHT), a classic traditional Chinese medicine (TCM) formula used for clearing heat and promoting body fluid, consists of four traditional Chinese medicines, i.e., Gypsum Fibrosum (Shigao), Anemarrhenae Rhizoma (Zhimu), Glycyrrhizae Radix et Rhizoma Praeparata cum Melle (Zhigancao), and nonglutinous rice (Jingmi). The chemical composition of BHT still remains largely elusive thus far. To qualitatively and quantitatively characterize secondary metabolites and carbohydrates in BHT, here a combination of analytical approaches using ultraperformance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry and ultraperformance liquid chromatography coupled with photodiode array detector was developed and validated. A total of 42 secondary metabolites in BHT were tentatively or definitely identified, of which 10 major chemicals were quantified by the extracting ion mode of quadrupole time-of-flight mass spectrometry. Meanwhile, polysaccharides, oligosaccharides, and monosaccharides in BHT were also characterized via sample pretreatment followed by sugar composition analysis. The quantitative results indicated that the determined chemicals accounted for 35.76% of the total extract of BHT, which demonstrated that the study could be instrumental in chemical dissection and quality control of BHT. The research deliverables not only laid the root for further chemical and biological evaluation of BHT, but also provided a comprehensive analytical strategy for chemical characterization of secondary metabolites and carbohydrates in traditional Chinese medicine formulas. Copyright © 2017. Published by Elsevier B.V.

Predicting cyanobacterial abundance, microcystin, and geosmin in a eutrophic drinking-water reservoir using a 14-year dataset

USGS Publications Warehouse

Harris, Ted D.; Graham, Jennifer L.

2017-01-01

Cyanobacterial blooms degrade water quality in drinking water supply reservoirs by producing toxic and taste-and-odor causing secondary metabolites, which ultimately cause public health concerns and lead to increased treatment costs for water utilities. There have been numerous attempts to create models that predict cyanobacteria and their secondary metabolites, most using linear models; however, linear models are limited by assumptions about the data and have had limited success as predictive tools. Thus, lake and reservoir managers need improved modeling techniques that can accurately predict large bloom events that have the highest impact on recreational activities and drinking-water treatment processes. In this study, we compared 12 unique linear and nonlinear regression modeling techniques to predict cyanobacterial abundance and the cyanobacterial secondary metabolites microcystin and geosmin using 14 years of physiochemical water quality data collected from Cheney Reservoir, Kansas. Support vector machine (SVM), random forest (RF), boosted tree (BT), and Cubist modeling techniques were the most predictive of the compared modeling approaches. SVM, RF, and BT modeling techniques were able to successfully predict cyanobacterial abundance, microcystin, and geosmin concentrations <60,000 cells/mL, 2.5 µg/L, and 20 ng/L, respectively. Only Cubist modeling predicted maxima concentrations of cyanobacteria and geosmin; no modeling technique was able to predict maxima microcystin concentrations. Because maxima concentrations are a primary concern for lake and reservoir managers, Cubist modeling may help predict the largest and most noxious concentrations of cyanobacteria and their secondary metabolites.

Consumption of a nectar alkaloid reduces pathogen load in bumble bees.

PubMed

Manson, Jessamyn S; Otterstatter, Michael C; Thomson, James D

2010-01-01

Diet has a significant effect on pathogen infections in animals and the consumption of secondary metabolites can either enhance or mitigate infection intensity. Secondary metabolites, which are commonly associated with herbivore defense, are also frequently found in floral nectar. One hypothesized function of this so-called toxic nectar is that it has antimicrobial properties, which may benefit insect pollinators by reducing the intensity of pathogen infections. We tested whether gelsemine, a nectar alkaloid of the bee-pollinated plant Gelsemium sempervirens, could reduce pathogen loads in bumble bees infected with the gut protozoan Crithidia bombi. In our first laboratory experiment, artificially infected bees consumed a daily diet of gelsemine post-infection to simulate continuous ingestion of alkaloid-rich nectar. In the second experiment, bees were inoculated with C. bombi cells that were pre-exposed to gelsemine, simulating the direct effects of nectar alkaloids on pathogen cells that are transmitted at flowers. Gelsemine significantly reduced the fecal intensity of C. bombi 7 days after infection when it was consumed continuously by infected bees, whereas direct exposure of the pathogen to gelsemine showed a non-significant trend toward reduced infection. Lighter pathogen loads may relieve bees from the behavioral impairments associated with the infection, thereby improving their foraging efficiency. If the collection of nectar secondary metabolites by pollinators is done as a means of self-medication, pollinators may selectively maintain secondary metabolites in the nectar of plants in natural populations.

UPLC-Q-TOF-HDMS analysis of constituents in the root of two kinds of Aconitum using a metabolomics approach.

PubMed

Sun, Hui; Wang, Mo; Zhang, Aihua; Ni, Bei; Dong, Hui; Wang, Xijun

2013-01-01

Metabolomics is an 'omics' approach that aims to comprehensively analyse all metabolites in a biological sample, and has great potential for directly elucidating plant metabolic processes. Increasing evidence supports the view that plants produce a broad range of low-molecular-weight secondary metabolites responsible for variation from species to species, thus enabling the use of secondary metabolite profiling in the chemotaxonomy. To gain deeper insights into the metabolites to increasing plant diversity, we performed systematic untargeted metabolite profiling to exploit the different parts and species of Aconitum as a case study. Application of ultraperformance liquid chromatography-quadrupole time-of-flight-high-definition mass spectrometry (UPLC-QTOF-HDMS) equipped with electrospray ionisation and coupled with pattern recognition analyses to study constituents in the root of two kinds of Aconitum species. Twenty-two metabolites between the mother root of Aconitum carmichaelii Debx (CHW) and lateral root of Aconitum carmichaelii Debx (SFZ) and 13 metabolites between the CHW and root of Aconitum kusnezoffii Reichb (CW) have been identified. Of note, songorine, carmichaeline and isotalatizidine did not exist in CW, whereas they are present in the SFZ and CHW. Metabolomics based UPLC-QTOF-HDMS with multivariate statistical models was effective for analysis of constituents in the root of two kinds of Aconitum species. Copyright © 2012 John Wiley & Sons, Ltd.

Improvement of hairy root cultures and plants by changing biosynthetic pathways leading to pharmaceutical metabolites: strategies and applications.

PubMed

Ludwig-Müller, Jutta; Jahn, Linda; Lippert, Annemarie; Püschel, Joachim; Walter, Antje

2014-11-01

A plethora of bioactive plant metabolites has been explored for pharmaceutical, food chemistry and agricultural applications. The chemical synthesis of these structures is often difficult, so plants are favorably used as producers. While whole plants can serve as a source for secondary metabolites and can be also improved by metabolic engineering, more often cell or organ cultures of relevant plant species are of interest. It should be noted that only in few cases the production for commercial application in such cultures has been achieved. Their genetic manipulation is sometimes faster and the production of a specific metabolite is more reliable, because of less environmental influences. In addition, upscaling in bioreactors is nowadays possible for many of these cultures, so some are already used in industry. There are approaches to alter the profile of metabolites not only by using plant genes, but also by using bacterial genes encoding modifying enzymes. Also, strategies to cope with unwanted or even toxic compounds are available. The need for metabolic engineering of plant secondary metabolite pathways is increasing with the rising demand for (novel) compounds with new bioactive properties. Here, we give some examples of recent developments for the metabolic engineering of plants and organ cultures, which can be used in the production of metabolites with interesting properties. Copyright © 2014 Elsevier Inc. All rights reserved.

The urinary metabolites of DINCH® have an impact on the activities of the human nuclear receptors ERα, ERβ, AR, PPARα and PPARγ.

PubMed

Engel, Anika; Buhrke, Thorsten; Kasper, Stefanie; Behr, Anne-Cathrin; Braeuning, Albert; Jessel, Sönke; Seidel, Albrecht; Völkel, Wolfgang; Lampen, Alfonso

2018-05-01

DINCH ® (di-isononyl cyclohexane-1,2-dicarboxylate) is a non-phthalate plasticizer that has been developed to replace phthalate plasticizers such as DEHP (di-2-ethylhexyl phthalate) or DINP (di-isononyl phthalate). DINCH ® is metabolized to its corresponding monoester and subsequently to oxidized monoester derivatives. These are conjugated to glucuronic acid and subject to urinary excretion. In contrast to DINCH ® , there are almost no toxicological data available regarding its primary and secondary metabolites. The present study aimed at the characterization of potential endocrine properties of DINCH ® and five DINCH ® metabolites by using reporter gene assays to monitor the activity of the human nuclear receptors ERα, ERβ, AR, PPARα and PPARγ in vitro. DINCH ® itself did not have any effect on the activity of these receptors whereas DINCH ® metabolites were shown to activate all these receptors. In the case of AR, DINCH ® metabolites predominantly enhanced dihydrotestosterone-stimulated AR activity. In the H295R steroidogenesis assay, neither DINCH ® nor any of its metabolites affected estradiol or testosterone synthesis. In conclusion, primary and secondary DINCH ® metabolites exert different effects at the molecular level compared to DINCH ® itself. All these in vitro effects of DINCH ® metabolites, however, were only observed at high concentrations such as 10 μM or above which is about three orders of magnitude above reported DINCH ® metabolite concentrations in human urine. Thus, the in vitro data do not support the notion that DINCH ® or any of the investigated metabolites may exert considerable endocrine effects in vivo at relevant human exposure levels. Copyright © 2018 Elsevier B.V. All rights reserved.

Mycotoxins: A Fungal Genomics Perspective

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, Daren W.; Baker, Scott E.

The chemical and enzymatic diversity in the fungal kingdom is staggering. Large-scale fungal genome sequencing projects are generating a massive catalog of secondary metabolite biosynthetic genes and pathways. Fungal natural products are a boon and bane to man as valuable pharmaceuticals and harmful toxins. Understanding how these chemicals are synthesized will aid the development of new strategies to limit mycotoxin contamination of food and feeds as well as expand drug discovery programs. A survey of work focused on the fumonisin family of mycotoxins highlights technological advances and provides a blueprint for future studies of other fungal natural products. Expressed sequencemore » tags led to the discovery of new fumonisin genes (FUM) and hinted at a role for alternatively spliced transcripts in regulation. Phylogenetic studies of FUM genes uncovered a complex evolutionary history of the FUM cluster, as well as fungi with the potential to synthesize fumonisin or fumonisin-like chemicals. The application of new technologies (e.g., CRISPR) could substantially impact future efforts to harness fungal resources.« less

Fluorescent techniques for discovery and characterization of phosphopantetheinyl transferase inhibitors

PubMed Central

Kosa, Nicolas M.; Foley, Timothy L.; Burkart, Michael D.

2016-01-01

Phosphopantetheinyl transferase (E.C. 2.7.8.-) activates biosynthetic pathways that synthesize both primary and secondary metabolites in bacteria. Inhibitors of these enzymes have the potential to serve as antibiotic compounds that function through a unique mode of action and possess clinical utility. Here we report a direct and continuous assay for this enzyme class based upon monitoring polarization of a fluorescent phosphopantetheine analog as it is transferred from a low molecular weight coenzyme A substrate to higher molecular weight protein acceptor. We demonstrate the utility of this method for the biochemical characterization of phosphopantetheinyl transferase Sfp, a canonical representative from this class. We also establish the portability of this technique to other homologs by adapting the assay to function with the human phosphopantetheinyl transferase, a target for which a microplate detection method does not currently exist. Comparison of these targets provides a basis to predict therapeutic index of inhibitor candidates and offers a valuable characterization of enzyme activity. PMID:24192555

Dual HIV-1 reverse transcriptase and integrase inhibitors from Limonium morisianum Arrigoni, an endemic species of Sardinia (Italy).

PubMed

Sanna, Cinzia; Rigano, Daniela; Corona, Angela; Piano, Dario; Formisano, Carmen; Farci, Domenica; Franzini, Genni; Ballero, Mauro; Chianese, Giuseppina; Tramontano, Enzo; Taglialatela-Scafati, Orazio; Esposito, Francesca

2018-02-04

During our search for potential templates of HIV-1 reverse transcriptase (RT) and integrase (IN) dual inhibitors, the methanolic extract obtained from aerial parts of Limonium morisianum was investigated. Repeated bioassay-guided chromatographic purifications led to the isolation of the following secondary metabolites: myricetin, myricetin 3-O-rutinoside, myricetin-3-O-(6″-O-galloyl)-β-d-galactopyranoside, (-)-epigallocatechin 3-O-gallate, tryptamine, ferulic and phloretic acids. The isolated compounds were tested on both HIV-1 RT-associated RNase H and IN activities. Interestingly, (-)-epigallocatechin-3-O-gallate and myricetin-3-O-(6″-O-galloyl)-β-d-galactopyranoside potently inhibited both enzyme activities with IC 50 values ranging from 0.21 to 10.9 μM. Differently, tryptamine and ferulic acid exhibited a significant inhibition only on the IN strand transfer reaction, showing a selectivity for this viral enzyme. Taken together these results strongly support the potential of this plant as a valuable anti HIV-1 drugs source worthy of further investigations.

Metabolic Changes during Storage of Brassica napus Seeds under Moist Conditions and the Consequences for the Sensory Quality of the Resulting Virgin Oil.

PubMed

Bonte, Anja; Schweiger, Rabea; Pons, Caroline; Wagner, Claudia; Brühl, Ludger; Matthäus, Bertrand; Müller, Caroline

2017-12-20

Virgin rapeseed (Brassica napus) oil is a valuable niche product, if delivered with a high quality. In this study, the effects of moist storage of B. napus seeds for 1 to 4 days on the seed metabolome and the chemo-sensory properties of the produced oils were determined. The concentrations of several primary metabolites, including monosaccharides and amino acids, rapidly increased in the seeds, probably indicating the breakdown of storage compounds to support seed germination. Seed concentrations of indole glucosinolates increased with a slight time offset suggesting that amino acids may be used to modify secondary metabolism. The volatile profiles of the oils were pronouncedly influenced by moist seed storage, with the sensory quality of the oils decreasing. This study provides a direct time-resolved link between seed metabolism under moist conditions and the quality of the resulting oils, thereby emphasizing the crucial role of dry seed storage in ensuring high oil quality.

An extended model of heartwood secondary metabolism informed by functional genomics.

PubMed

Celedon, Jose M; Bohlmann, Jörg

2018-03-01

The development of heartwood (HW) and the associated accumulation of secondary metabolites, which are also known as 'specialized metabolites' or 'extractives', is an important feature of tree biology. Heartwood development can affect tree health with broader implications for forest health. Heartwood development also defines a variety of wood quality traits that are important in the forest industry such as durability and colour of wood products. In the bioproducts industry, HW provides a source of high-value small molecules such as fragrances and antimicrobials. The HW properties of decay resistance in living trees, durability and colour of wood products, and small molecule bioproducts are largely defined by secondary metabolites, the biosynthesis of which appears to be activated during the onset of HW formation. Traditionally, it is thought that HW formation involves a spike in the activity of secondary metabolism in parenchyma cells in a transition zone between sapwood and HW, followed by programmed cell-death. The resulting HW tissue is thought to consist entirely of dead cells. Here, we discuss a variation of existing models of HW formation, based on the recent discovery of HW-specific transcriptome signatures of terpenoid biosynthesis in sandalwood (Santalum album L.) that invokes the activity of living cells in HW.

Toward Systems Metabolic Engineering of Streptomycetes for Secondary Metabolites Production.

PubMed

Robertsen, Helene Lunde; Weber, Tilmann; Kim, Hyun Uk; Lee, Sang Yup

2018-01-01

Streptomycetes are known for their inherent ability to produce pharmaceutically relevant secondary metabolites. Discovery of medically useful, yet novel compounds has become a great challenge due to frequent rediscovery of known compounds and a consequent decline in the number of relevant clinical trials in the last decades. A paradigm shift took place when the first whole genome sequences of streptomycetes became available, from which silent or "cryptic" biosynthetic gene clusters (BGCs) were discovered. Cryptic BGCs reveal a so far untapped potential of the microorganisms for the production of novel compounds, which has spurred new efforts in understanding the complex regulation between primary and secondary metabolism. This new trend has been accompanied with development of new computational resources (genome and compound mining tools), generation of various high-quality omics data, establishment of molecular tools, and other strain engineering strategies. They all come together to enable systems metabolic engineering of streptomycetes, allowing more systematic and efficient strain development. In this review, the authors present recent progresses within systems metabolic engineering of streptomycetes for uncovering their hidden potential to produce novel compounds and for the improved production of secondary metabolites. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

On the Developmental and Environmental Regulation of Secondary Metabolism in Vaccinium spp. Berries

PubMed Central

Karppinen, Katja; Zoratti, Laura; Nguyenquynh, Nga; Häggman, Hely; Jaakola, Laura

2016-01-01

Secondary metabolites have important defense and signaling roles, and they contribute to the overall quality of developing and ripening fruits. Blueberries, bilberries, cranberries, and other Vaccinium berries are fleshy berry fruits recognized for the high levels of bioactive compounds, especially anthocyanin pigments. Besides anthocyanins and other products of the phenylpropanoid and flavonoid pathways, these berries also contain other metabolites of interest, such as carotenoid derivatives, vitamins and flavor compounds. Recently, new information has been achieved on the mechanisms related with developmental, environmental, and genetic factors involved in the regulation of secondary metabolism in Vaccinium fruits. Especially light conditions and temperature are demonstrated to have a prominent role on the composition of phenolic compounds. The present review focuses on the studies on mechanisms associated with the regulation of key secondary metabolites, mainly phenolic compounds, in Vaccinium berries. The advances in the research concerning biosynthesis of phenolic compounds in Vaccinium species, including specific studies with mutant genotypes in addition to controlled and field experiments on the genotype × environment (G×E) interaction, are discussed. The recently published Vaccinium transcriptome and genome databases provide new tools for the studies on the metabolic routes. PMID:27242856

Endophytic actinobacteria: Diversity, secondary metabolism and mechanisms to unsilence biosynthetic gene clusters.

PubMed

Dinesh, Raghavan; Srinivasan, Veeraraghavan; T E, Sheeja; Anandaraj, Muthuswamy; Srambikkal, Hamza

2017-09-01

Endophytic actinobacteria, which reside in the inner tissues of host plants, are gaining serious attention due to their capacity to produce a plethora of secondary metabolites (e.g. antibiotics) possessing a wide variety of biological activity with diverse functions. This review encompasses the recent reports on endophytic actinobacterial species diversity, in planta habitats and mechanisms underlying their mode of entry into plants. Besides, their metabolic potential, novel bioactive compounds they produce and mechanisms to unravel their hidden metabolic repertoire by activation of cryptic or silent biosynthetic gene clusters (BGCs) for eliciting novel secondary metabolite production are discussed. The study also reviews the classical conservative techniques (chemical/biological/physical elicitation, co-culturing) as well as modern microbiology tools (e.g. next generation sequencing) that are being gainfully employed to uncover the vast hidden scaffolds for novel secondary metabolites produced by these endophytes, which would subsequently herald a revolution in drug engineering. The potential role of these endophytes in the agro-environment as promising biological candidates for inhibition of phytopathogens and the way forward to thoroughly exploit this unique microbial community by inducing expression of cryptic BGCs for encoding unseen products with novel therapeutic properties are also discussed.

Natural products: Hunting microbial metabolites

NASA Astrophysics Data System (ADS)

Schmidt, Eric W.

2015-05-01

Symbiotic bacteria synthesize many specialized small molecules; however, establishing the role these chemicals play in human health and disease has been difficult. Now, the chemical structure and mechanism of the Escherichia coli product colibactin provides insight into the link between this secondary metabolite and colorectal cancer.

Blackberry fruit quality components, composition, and potential health benefits

USDA-ARS?s Scientific Manuscript database

Blackberries have long been a popular small fruit. Their chemical composition data was assembled for this invited book chapter. Briefly, primary and secondary metabolites important to blackberry fruit quality were summarized. Metabolites are involved in many critical aspects of fruit quality includi...

The AMP-Activated Protein Kinase Homolog Snf1 Concerts Carbon Utilization, Conidia Production and the Biosynthesis of Secondary Metabolites in the Taxol-Producer Pestalotiopsis microspora.

PubMed

Wang, Dan; Li, Yingying; Wang, Haichuan; Wei, Dongsheng; Akhberdi, Oren; Liu, Yanjie; Xiang, Biyun; Hao, Xiaoran; Zhu, Xudong

2018-01-24

Highly conserved, the Snf1/AMPK is a central regulator of carbon metabolism and energy production in the eukaryotes. However, its function in filamentous fungi has not been well established. In this study, we reported functional characterization of Snf1/AMPK in the growth, development and secondary metabolism in the filamentous fungus Pestalotiopsis microspora . By deletion of the yeast SNF1 homolog, we found that it regulated the utilization of carbon sources, e.g., sucrose, demonstrating a conserved function of this kinase in filamentous fungus. Importantly, several novel functions of SNF1 were unraveled. For instance, the deletion strain displayed remarkable retardation in vegetative growth and pigmentation and produced a diminished number of conidia, even in the presence of the primary carbon source glucose. Deletion of the gene caused damages in the cell wall as shown by its hypersensitivities to Calcofluor white and Congo red, suggesting a critical role of Snf1 in maintaining cell wall integrity. Furthermore, the mutant strain Δ snf1 was hypersensitive to stress, e.g., osmotic pressure (1 M sorbitol), drug G418 and heat shock, though the mechanism remains to be illustrated. Significantly, disruption of the gene altered the production of secondary metabolites. By high-performance liquid chromatography (HPLC) profiling, we found that Δ snf1 barely produced secondary metabolites, e.g., the known product pestalotiollide B. This study suggests that Snf1 is a key regulator in filamentous fungus Pestalotiopsis microspora concerting carbon metabolism and the filamentous growth, conidiation, cell wall integrity, stress tolerance and the biosynthesis of secondary metabolites.

The AMP-Activated Protein Kinase Homolog Snf1 Concerts Carbon Utilization, Conidia Production and the Biosynthesis of Secondary Metabolites in the Taxol-Producer Pestalotiopsis microspora

PubMed Central

Wang, Dan; Li, Yingying; Wang, Haichuan; Wei, Dongsheng; Akhberdi, Oren; Liu, Yanjie; Xiang, Biyun; Hao, Xiaoran; Zhu, Xudong

2018-01-01

Highly conserved, the Snf1/AMPK is a central regulator of carbon metabolism and energy production in the eukaryotes. However, its function in filamentous fungi has not been well established. In this study, we reported functional characterization of Snf1/AMPK in the growth, development and secondary metabolism in the filamentous fungus Pestalotiopsis microspora. By deletion of the yeast SNF1 homolog, we found that it regulated the utilization of carbon sources, e.g., sucrose, demonstrating a conserved function of this kinase in filamentous fungus. Importantly, several novel functions of SNF1 were unraveled. For instance, the deletion strain displayed remarkable retardation in vegetative growth and pigmentation and produced a diminished number of conidia, even in the presence of the primary carbon source glucose. Deletion of the gene caused damages in the cell wall as shown by its hypersensitivities to Calcofluor white and Congo red, suggesting a critical role of Snf1 in maintaining cell wall integrity. Furthermore, the mutant strain Δsnf1 was hypersensitive to stress, e.g., osmotic pressure (1 M sorbitol), drug G418 and heat shock, though the mechanism remains to be illustrated. Significantly, disruption of the gene altered the production of secondary metabolites. By high-performance liquid chromatography (HPLC) profiling, we found that Δsnf1 barely produced secondary metabolites, e.g., the known product pestalotiollide B. This study suggests that Snf1 is a key regulator in filamentous fungus Pestalotiopsis microspora concerting carbon metabolism and the filamentous growth, conidiation, cell wall integrity, stress tolerance and the biosynthesis of secondary metabolites. PMID:29364863

Marine Microbial Secondary Metabolites: Pathways, Evolution and Physiological Roles.

PubMed

Giordano, Daniela; Coppola, Daniela; Russo, Roberta; Denaro, Renata; Giuliano, Laura; Lauro, Federico M; di Prisco, Guido; Verde, Cinzia

2015-01-01

Microbes produce a huge array of secondary metabolites endowed with important ecological functions. These molecules, which can be catalogued as natural products, have long been exploited in medical fields as antibiotics, anticancer and anti-infective agents. Recent years have seen considerable advances in elucidating natural-product biosynthesis and many drugs used today are natural products or natural-product derivatives. The major contribution to recent knowledge came from application of genomics to secondary metabolism and was facilitated by all relevant genes being organised in a contiguous DNA segment known as gene cluster. Clustering of genes regulating biosynthesis in bacteria is virtually universal. Modular gene clusters can be mixed and matched during evolution to generate structural diversity in natural products. Biosynthesis of many natural products requires the participation of complex molecular machines known as polyketide synthases and non-ribosomal peptide synthetases. Discovery of new evolutionary links between the polyketide synthase and fatty acid synthase pathways may help to understand the selective advantages that led to evolution of secondary-metabolite biosynthesis within bacteria. Secondary metabolites confer selective advantages, either as antibiotics or by providing a chemical language that allows communication among species, with other organisms and their environment. Herewith, we discuss these aspects focusing on the most clinically relevant bioactive molecules, the thiotemplated modular systems that include polyketide synthases, non-ribosomal peptide synthetases and fatty acid synthases. We begin by describing the evolutionary and physiological role of marine natural products, their structural/functional features, mechanisms of action and biosynthesis, then turn to genomic and metagenomic approaches, highlighting how the growing body of information on microbial natural products can be used to address fundamental problems in environmental evolution and biotechnology. © 2015 Elsevier Ltd. All rights reserved.

Sucrose-enhanced biosynthesis of medicinally important antioxidant secondary metabolites in cell suspension cultures of Artemisia absinthium L.

PubMed

Ali, Mohammad; Abbasi, Bilal Haider; Ahmad, Nisar; Ali, Syed Shujait; Ali, Shahid; Ali, Gul Shad

2016-12-01

Natural products are gaining tremendous importance in pharmaceutical industry and attention has been focused on the applications of in vitro technologies to enhance yield and productivity of such products. In this study, we investigated the accumulation of biomass and antioxidant secondary metabolites in response to different carbohydrate sources (sucrose, maltose, fructose and glucose) and sucrose concentrations (1, 3, 5, 7 and 9 %). Moreover, the effects of 3 % repeated sucrose feeding (day-12, -18 and -24) were also investigated. The results showed the superiority of disaccharides over monosaccharides for maximum biomass and secondary metabolites accumulation. Comparable profiles for maximum biomass were observed in response to sucrose and maltose and initial sucrose concentrations of 3 and 5 %. Maximum total phenolic and total flavonoid contents were displayed by cultures treated with sucrose and maltose; however, initial sucrose concentrations of 5 and 7 % were optimum for both classes of metabolites, respectively. Following 3 % extra sucrose feeding, cultures fed on day-24 (late-log phase) showed higher biomass, total phenolic and total flavonoid contents as compared to control cultures. Highest antioxidant activity was exhibited by maltose-treated cultures. Moreover, sucrose-treated cultures displayed positive correlation of antioxidant activity with total phenolics and total flavonoids production. This work describes the stimulatory role of disaccharides and sucrose feeding strategy for higher accumulation of phenolics and flavonoids, which could be potentially scaled up to bioreactor level for the bulk production of these metabolites in suspension cultures of A. absinthium.

Secondary metabolite profiles and antifungal drug susceptibility of Aspergillus fumigatus and closely related species, Aspergillus lentulus, Aspergillus udagawae, and Aspergillus viridinutans.

PubMed

Tamiya, Hiroyuki; Ochiai, Eri; Kikuchi, Kazuyo; Yahiro, Maki; Toyotome, Takahito; Watanabe, Akira; Yaguchi, Takashi; Kamei, Katsuhiko

2015-05-01

The incidence of Aspergillus infection has been increasing in the past few years. Also, new Aspergillus fumigatus-related species, namely Aspergillus lentulus, Aspergillus udagawae, and Aspergillus viridinutans, were shown to infect humans. These fungi exhibit marked morphological similarities to A. fumigatus, albeit with different clinical courses and antifungal drug susceptibilities. The present study used liquid chromatography/time-of-flight mass spectrometry to identify the secondary metabolites secreted as virulence factors by these Aspergillus species and compared their antifungal susceptibility. The metabolite profiles varied widely among A. fumigatus, A. lentulus, A. udagawae, and A. viridinutans, producing 27, 13, 8, and 11 substances, respectively. Among the mycotoxins, fumifungin, fumiquinazoline A/B and D, fumitremorgin B, gliotoxin, sphingofungins, pseurotins, and verruculogen were only found in A. fumigatus, whereas auranthine was only found in A. lentulus. The amount of gliotoxin, one of the most abundant mycotoxins in A. fumigatus, was negligible in these related species. In addition, they had decreased susceptibility to antifungal agents such as itraconazole and voriconazole, even though metabolites that were shared in the isolates showing higher minimum inhibitory concentrations than epidemiological cutoff values were not detected. These strikingly different secondary metabolite profiles may lead to the development of more discriminative identification protocols for such closely related Aspergillus species as well as improved treatment outcomes. Copyright © 2015 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Harzianolide, a novel plant growth regulator and systemic resistance elicitor from Trichoderma harzianum.

PubMed

Cai, Feng; Yu, Guanghui; Wang, Ping; Wei, Zhong; Fu, Lin; Shen, Qirong; Chen, Wei

2013-12-01

A detailed understanding of the effect of natural products on plant growth and protection will underpin new product development for plant production. The isolation and characterization of a known secondary metabolite named harzianolide from Trichoderma harzianum strain SQR-T037 were described, and the bioactivity of the purified compound as well as the crude metabolite extract in plant growth promotion and systemic resistance induction was investigated in this study. The results showed that harzianolide significantly promoted tomato seedling growth by up to 2.5-fold (dry weight) at a concentration of 0.1 ppm compared with the control. The result of root scan suggested that Trichoderma secondary metabolites may influence the early stages of plant growth through better root development for the enhancement of root length and tips. Both of the purified harzianolide and crude metabolite extract increased the activity of some defense-related enzymes to response to oxidative stress. Examination of six defense-related gene expression by real-time reverse transcription-PCR analysis revealed that harzianolide induces the expression of genes involved in the salicylic acid (PR1 and GLU) and jasmonate/ethylene (JERF3) signaling pathways while crude metabolite extract inhibited some gene expression (CHI-II and PGIP) related to basal defense in tomato plants. Further experiment showed that a subsequent challenge of harzianolide-pretreated plants with the pathogen Sclerotinia sclerotiorum resulted in higher systemic resistance by the reduction of lesion size. These results indicate that secondary metabolites of Trichoderma spp., like harzianolide, may play a novel role in both plant growth regulation and plant defense responses. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Extracellular Microbial Metabolomics: The State of the Art

PubMed Central

Villas-Boas, Silas G.

2017-01-01

Microorganisms produce and secrete many primary and secondary metabolites to the surrounding environment during their growth. Therefore, extracellular metabolites provide important information about the changes in microbial metabolism due to different environmental cues. The determination of these metabolites is also comparatively easier than the extraction and analysis of intracellular metabolites as there is no need for cell rupture. Many analytical methods are already available and have been used for the analysis of extracellular metabolites from microorganisms over the last two decades. Here, we review the applications and benefits of extracellular metabolite analysis. We also discuss different sample preparation protocols available in the literature for both types (e.g., metabolites in solution and in gas) of extracellular microbial metabolites. Lastly, we evaluate the authenticity of using extracellular metabolomics data in the metabolic modelling of different industrially important microorganisms. PMID:28829385

Extracellular Microbial Metabolomics: The State of the Art.

PubMed

Pinu, Farhana R; Villas-Boas, Silas G

2017-08-22

Microorganisms produce and secrete many primary and secondary metabolites to the surrounding environment during their growth. Therefore, extracellular metabolites provide important information about the changes in microbial metabolism due to different environmental cues. The determination of these metabolites is also comparatively easier than the extraction and analysis of intracellular metabolites as there is no need for cell rupture. Many analytical methods are already available and have been used for the analysis of extracellular metabolites from microorganisms over the last two decades. Here, we review the applications and benefits of extracellular metabolite analysis. We also discuss different sample preparation protocols available in the literature for both types (e.g., metabolites in solution and in gas) of extracellular microbial metabolites. Lastly, we evaluate the authenticity of using extracellular metabolomics data in the metabolic modelling of different industrially important microorganisms.

The TolC-like protein HgdD of the cyanobacterium Anabaena sp. PCC 7120 is involved in secondary metabolite export and antibiotic resistance.

PubMed

Hahn, Alexander; Stevanovic, Mara; Mirus, Oliver; Schleiff, Enrico

2012-11-30

The role of TolC has largely been explored in proteobacteria, where it functions as a metabolite and protein exporter. In contrast, little research has been carried out on the function of cyanobacterial homologues, and as a consequence, not much is known about the mechanism of cyanobacterial antibiotic uptake and metabolite secretion in general. It has been suggested that the TolC-like homologue of the filamentous, heterocyst-forming cyanobacterium Anabaena sp. PCC 7120, termed heterocyst glycolipid deposition protein D (HgdD), is involved in both protein and lipid secretion. To describe its function in secondary metabolite secretion, we established a system to measure the uptake of antibiotics based on the fluorescent molecule ethidium bromide. We analyzed the rate of porin-dependent metabolite uptake and confirmed the functional relation between detoxification and the action of HgdD. Moreover, we identified two major facilitator superfamily proteins that are involved in this process. It appears that anaOmp85 (Alr2269) is not required for insertion or assembly of HgdD, because an alr2269 mutant does not exhibit a phenotype similar to the hgdD mutant. Thus, we could assign components of the metabolite efflux system and describe parameters of detoxification by Anabaena sp. PCC 7120.

Metabolomic profiling of the phytomedicinal constituents of Carica papaya L. leaves and seeds by 1H NMR spectroscopy and multivariate statistical analysis.

PubMed

Gogna, Navdeep; Hamid, Neda; Dorai, Kavita

2015-11-10

Extracts from the Carica papaya L. plant are widely reported to contain metabolites with antibacterial, antioxidant and anticancer activity. This study aims to analyze the metabolic profiles of papaya leaves and seeds in order to gain insights into their phytomedicinal constituents. We performed metabolite fingerprinting using 1D and 2D 1H NMR experiments and used multivariate statistical analysis to identify those plant parts that contain the most concentrations of metabolites of phytomedicinal value. Secondary metabolites such as phenyl propanoids, including flavonoids, were found in greater concentrations in the leaves as compared to the seeds. UPLC-ESI-MS verified the presence of significant metabolites in the papaya extracts suggested by the NMR analysis. Interestingly, the concentration of eleven secondary metabolites namely caffeic, cinnamic, chlorogenic, quinic, coumaric, vanillic, and protocatechuic acids, naringenin, hesperidin, rutin, and kaempferol, were higher in young as compared to old papaya leaves. The results of the NMR analysis were corroborated by estimating the total phenolic and flavonoid content of the extracts. Estimation of antioxidant activity in leaves and seed extracts by DPPH and ABTS in-vitro assays and antioxidant capacity in C2C12 cell line also showed that papaya extracts exhibit high antioxidant activity. Copyright © 2015 Elsevier B.V. All rights reserved.

Secondary metabolite profiling of Curcuma species grown at different locations using GC/TOF and UPLC/Q-TOF MS.

PubMed

Lee, Jueun; Jung, Youngae; Shin, Jeoung-Hwa; Kim, Ho Kyoung; Moon, Byeong Cheol; Ryu, Do Hyun; Hwang, Geum-Sook

2014-07-04

Curcuma, a genus of rhizomatous herbaceous species, has been used as a spice, traditional medicine, and natural dye. In this study, the metabolite profile of Curcuma extracts was determined using gas chromatography-time of flight mass spectrometry (GC/TOF MS) and ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF MS) to characterize differences between Curcuma aromatica and Curcuma longa grown on the Jeju-do or Jin-do islands, South Korea. Previous studies have performed primary metabolite profiling of Curcuma species grown in different regions using NMR-based metabolomics. This study focused on profiling of secondary metabolites from the hexane extract of Curcuma species. Principal component analysis (PCA) and partial least-squares discriminant analysis (PLS-DA) plots showed significant differences between the C. aromatica and C. longa metabolite profiles, whereas geographical location had little effect. A t-test was performed to identify statistically significant metabolites, such as terpenoids. Additionally, targeted profiling using UPLC/Q-TOF MS showed that the concentration of curcuminoids differed depending on the plant origin. Based on these results, a combination of GC- and LC-MS allowed us to analyze curcuminoids and terpenoids, the typical bioactive compounds of Curcuma, which can be used to discriminate Curcuma samples according to species or geographical origin.

Nostopeptolide plays a governing role during cellular differentiation of the symbiotic cyanobacterium Nostoc punctiforme.

PubMed

Liaimer, Anton; Helfrich, Eric J N; Hinrichs, Katrin; Guljamow, Arthur; Ishida, Keishi; Hertweck, Christian; Dittmann, Elke

2015-02-10

Nostoc punctiforme is a versatile cyanobacterium that can live either independently or in symbiosis with plants from distinct taxa. Chemical cues from plants and N. punctiforme were shown to stimulate or repress, respectively, the differentiation of infectious motile filaments known as hormogonia. We have used a polyketide synthase mutant that accumulates an elevated amount of hormogonia as a tool to understand the effect of secondary metabolites on cellular differentiation of N. punctiforme. Applying MALDI imaging to illustrate the reprogramming of the secondary metabolome, nostopeptolides were identified as the predominant difference in the pks2(-) mutant secretome. Subsequent differentiation assays and visualization of cell-type-specific expression of nostopeptolides via a transcriptional reporter strain provided evidence for a multifaceted role of nostopeptolides, either as an autogenic hormogonium-repressing factor or as a chemoattractant, depending on its extracellular concentration. Although nostopeptolide is constitutively expressed in the free-living state, secreted levels dynamically change before, during, and after the hormogonium differentiation phase. The metabolite was found to be strictly down-regulated in symbiosis with Gunnera manicata and Blasia pusilla, whereas other metabolites are up-regulated, as demonstrated via MALDI imaging, suggesting plants modulate the fine-balanced cross-talk network of secondary metabolites within N. punctiforme.

Nostopeptolide plays a governing role during cellular differentiation of the symbiotic cyanobacterium Nostoc punctiforme

PubMed Central

Liaimer, Anton; Helfrich, Eric J. N.; Hinrichs, Katrin; Guljamow, Arthur; Ishida, Keishi; Hertweck, Christian; Dittmann, Elke

2015-01-01

Nostoc punctiforme is a versatile cyanobacterium that can live either independently or in symbiosis with plants from distinct taxa. Chemical cues from plants and N. punctiforme were shown to stimulate or repress, respectively, the differentiation of infectious motile filaments known as hormogonia. We have used a polyketide synthase mutant that accumulates an elevated amount of hormogonia as a tool to understand the effect of secondary metabolites on cellular differentiation of N. punctiforme. Applying MALDI imaging to illustrate the reprogramming of the secondary metabolome, nostopeptolides were identified as the predominant difference in the pks2− mutant secretome. Subsequent differentiation assays and visualization of cell-type-specific expression of nostopeptolides via a transcriptional reporter strain provided evidence for a multifaceted role of nostopeptolides, either as an autogenic hormogonium-repressing factor or as a chemoattractant, depending on its extracellular concentration. Although nostopeptolide is constitutively expressed in the free-living state, secreted levels dynamically change before, during, and after the hormogonium differentiation phase. The metabolite was found to be strictly down-regulated in symbiosis with Gunnera manicata and Blasia pusilla, whereas other metabolites are up-regulated, as demonstrated via MALDI imaging, suggesting plants modulate the fine-balanced cross-talk network of secondary metabolites within N. punctiforme. PMID:25624477

Penicillium arizonense, a new, genome sequenced fungal species, reveals a high chemical diversity in secreted metabolites.

PubMed

Grijseels, Sietske; Nielsen, Jens Christian; Randelovic, Milica; Nielsen, Jens; Nielsen, Kristian Fog; Workman, Mhairi; Frisvad, Jens Christian

2016-10-14

A new soil-borne species belonging to the Penicillium section Canescentia is described, Penicillium arizonense sp. nov. (type strain CBS 141311 T  = IBT 12289 T ). The genome was sequenced and assembled into 33.7 Mb containing 12,502 predicted genes. A phylogenetic assessment based on marker genes confirmed the grouping of P. arizonense within section Canescentia. Compared to related species, P. arizonense proved to encode a high number of proteins involved in carbohydrate metabolism, in particular hemicellulases. Mining the genome for genes involved in secondary metabolite biosynthesis resulted in the identification of 62 putative biosynthetic gene clusters. Extracts of P. arizonense were analysed for secondary metabolites and austalides, pyripyropenes, tryptoquivalines, fumagillin, pseurotin A, curvulinic acid and xanthoepocin were detected. A comparative analysis against known pathways enabled the proposal of biosynthetic gene clusters in P. arizonense responsible for the synthesis of all detected compounds except curvulinic acid. The capacity to produce biomass degrading enzymes and the identification of a high chemical diversity in secreted bioactive secondary metabolites, offers a broad range of potential industrial applications for the new species P. arizonense. The description and availability of the genome sequence of P. arizonense, further provides the basis for biotechnological exploitation of this species.

Penicillium arizonense, a new, genome sequenced fungal species, reveals a high chemical diversity in secreted metabolites

PubMed Central

Grijseels, Sietske; Nielsen, Jens Christian; Randelovic, Milica; Nielsen, Jens; Nielsen, Kristian Fog; Workman, Mhairi; Frisvad, Jens Christian

2016-01-01

A new soil-borne species belonging to the Penicillium section Canescentia is described, Penicillium arizonense sp. nov. (type strain CBS 141311T = IBT 12289T). The genome was sequenced and assembled into 33.7 Mb containing 12,502 predicted genes. A phylogenetic assessment based on marker genes confirmed the grouping of P. arizonense within section Canescentia. Compared to related species, P. arizonense proved to encode a high number of proteins involved in carbohydrate metabolism, in particular hemicellulases. Mining the genome for genes involved in secondary metabolite biosynthesis resulted in the identification of 62 putative biosynthetic gene clusters. Extracts of P. arizonense were analysed for secondary metabolites and austalides, pyripyropenes, tryptoquivalines, fumagillin, pseurotin A, curvulinic acid and xanthoepocin were detected. A comparative analysis against known pathways enabled the proposal of biosynthetic gene clusters in P. arizonense responsible for the synthesis of all detected compounds except curvulinic acid. The capacity to produce biomass degrading enzymes and the identification of a high chemical diversity in secreted bioactive secondary metabolites, offers a broad range of potential industrial applications for the new species P. arizonense. The description and availability of the genome sequence of P. arizonense, further provides the basis for biotechnological exploitation of this species. PMID:27739446

STUDIES OF METABOLITE-PROTEIN INTERACTIONS: A REVIEW

PubMed Central

Matsuda, Ryan; Bi, Cong; Anguizola, Jeanethe; Sobansky, Matthew; Rodriquez, Elliot; Badilla, John Vargas; Zheng, Xiwei; Hage, Benjamin; Hage, David S.

2014-01-01

The study of metabolomics can provide valuable information about biochemical pathways and processes at the molecular level. There have been many reports that have examined the structure, identity and concentrations of metabolites in biological systems. However, the binding of metabolites with proteins is also of growing interest. This review examines past reports that have looked at the binding of various types of metabolites with proteins. An overview of the techniques that have been used to characterize and study metabolite-protein binding is first provided. This is followed by examples of studies that have investigated the binding of hormones, fatty acids, drugs or other xenobiotics, and their metabolites with transport proteins and receptors. These examples include reports that have considered the structure of the resulting solute-protein complexes, the nature of the binding sites, the strength of these interactions, the variations in these interactions with solute structure, and the kinetics of these reactions. The possible effects of metabolic diseases on these processes, including the impact of alterations in the structure and function of proteins, are also considered. PMID:24321277

Mining Genomes of Biological Control Strains of Pseudomonas spp.: Unexpected Gems and Tailings

USDA-ARS?s Scientific Manuscript database

The biocontrol bacterium Pseudomonas fluorescens Pf-5 suppresses numerous soilborne plant diseases and produces an array of structurally-characterized secondary metabolites that are toxic to plant pathogenic bacteria, fungi and Oomycetes. Biosynthetic gene clusters for these metabolites compose nea...

Plant defense activators as elicitors of oat avenanthramide biosynthesis

USDA-ARS?s Scientific Manuscript database

Oats produce a group of phenolic secondary metabolites termed “avenanthramides”. Among food crops these metabolites are unique to oat. In addition to their biological role as phytoalexins, the avenanthramides are potent antioxidants in vitro and have potential as nutraceuticals. In cellular assays ...

Improved Growth and Metabolite Accumulation in Codonopsis pilosula (Franch.) Nannf. by Inoculation of Bacillus amyloliquefaciens GB03.

PubMed

Zhao, Qi; Wu, Yong-Na; Fan, Qin; Han, Qing-Qing; Paré, Paul W; Xu, Rui; Wang, Yin-Quan; Wang, Suo-Min; Zhang, Jin-Lin

2016-11-02

Codonopsis pilosula (Franch.) Nannf. is a traditional Chinese herbal medicinal plant and a low-cost succedaneum for Panax ginseng and contains various bioactivity components. In this work, we first evaluated the effects of the inoculation of the plant growth-promoting rhizobacteria Bacillus amyloliquefaciens strain GB03 on growth and metabolite accumulation of C. pilosula. The results demonstrated that application of B. amyloliquefaciens GB03 significantly improved the growth of C. pilosula compared to DH5α, Luria broth medium, and water treatment, respectively. On the other hand, we observed that the content of lobetyolin, one of the most important secondary metabolites in C. pilosula, was obviously improved by inoculation of GB03 and almost reached twice that compared to the other three treatments. In addition, some amino acids of roots were elevated by GB03, although not significantly. In conclusion, B. amyloliquefaciens GB03 could induce positive effects on the growth and further stimulate accumulation of secondary metabolites in C. pilosula.

Metabolomics Reveal Optimal Grain Preprocessing (Milling) toward Rice Koji Fermentation.

PubMed

Lee, Sunmin; Lee, Da Eun; Singh, Digar; Lee, Choong Hwan

2018-03-21

A time-correlated mass spectrometry (MS)-based metabolic profiling was performed for rice koji made using the substrates with varying degrees of milling (DOM). Overall, 67 primary and secondary metabolites were observed as significantly discriminant among different samples. Notably, a higher abundance of carbohydrate (sugars, sugar alcohols, organic acids, and phenolic acids) and lipid (fatty acids and lysophospholipids) derived metabolites with enhanced hydrolytic enzyme activities were observed for koji made with DOM of 5-7 substrates at 36 h. The antioxidant secondary metabolites (flavonoids and phenolic acid) were relatively higher in koji with DOM of 0 substrates, followed by DOM of 5 > DOM of 7 > DOM of 9 and 11 at 96 h. Hence, we conjecture that the rice substrate preprocessing between DOM of 5 and 7 was potentially optimal toward koji fermentation, with the end product being rich in distinctive organoleptic, nutritional, and functional metabolites. The study rationalizes the substrate preprocessing steps vital for commercial koji making.

Penicillium roqueforti: a multifunctional cell factory of high value-added molecules.

PubMed

Mioso, R; Toledo Marante, F J; Herrera Bravo de Laguna, I

2015-04-01

This is a comprehensive review, with 114 references, of the chemical diversity found in the fungus Penicillium roqueforti. Secondary metabolites of an alkaloidal nature are described, for example, ergot alkaloids such as festuclavine, isofumigaclavines A and B, and diketopiperazine alkaloids such as roquefortines A-D, which are derived from imidazole. Other metabolites are marcfortines A-C, PR-toxin, eremofortines A-E, mycophenolic and penicillic acids, and some γ-lactones. Also, recent developments related to the structural characteristics of botryodiplodin and andrastin are studied-the latter has anticancer properties. Finally, we discuss the enzymes of P. roqueforti, which can participate in the biotechnological production of high value-added molecules, as well as the use of secondary metabolite profiles for taxonomic purposes. © 2014 The Society for Applied Microbiology.

A new species of Trichoderma hypoxylon harbours abundant secondary metabolites.

PubMed

Sun, Jingzu; Pei, Yunfei; Li, Erwei; Li, Wei; Hyde, Kevin D; Yin, Wen-Bing; Liu, Xingzhong

2016-11-21

Some species of Trichoderma are fungicolous on fungi and have been extensively studied and commercialized as biocontrol agents. Multigene analyses coupled with morphology, resulted in the discovery of T. hypoxylon sp. nov., which was isolated from surface of the stroma of Hypoxylon anthochroum. The new taxon produces Trichoderma- to Verticillium-like conidiophores and hyaline conidia. Phylogenetic analyses based on combined ITS, TEF1-α and RPB2 sequence data indicated that T. hypoxylon is a well-distinguished species with strong bootstrap support in the polysporum group. Chemical assessment of this species reveals a richness of secondary metabolites with trichothecenes and epipolythiodiketopiperazines as the major compounds. The fungicolous life style of T. hypoxylon and the production of abundant metabolites are indicative of the important ecological roles of this species in nature.

Quantitative determination of secoiridoid and gamma-pyrone compounds in Gentiana lutea cultured in vitro.

PubMed

Menković, N; Savikin-Fodulović, K; Momcilović, I; Grubisić, D

2000-02-01

The production of secondary metabolites was studied in shoots, roots, and hairy roots of Gentiana lutea obtained in vitro. In shoots, both secoiridoid and gamma-pyrone compounds were detected in amounts similar to those found in aerial parts of plants collected from nature. The most abundant secoiridoid was gentiopicrin while mangiferin was the main compound among the gamma-pyrones. The adventitious roots obtained in vitro showed a poor biosynthetic capacity. Upon infection with Agrobacterium rhizogenes, nine hairy root clones were established which differed in the amount of secondary metabolites.

Omics and multi-omics approaches to study the biosynthesis of secondary metabolites in microorganisms.

PubMed

Palazzotto, Emilia; Weber, Tilmann

2018-04-12

Natural products produced by microorganisms represent the main source of bioactive molecules. The development of high-throughput (omics) techniques have importantly contributed to the renaissance of new antibiotic discovery increasing our understanding of complex mechanisms controlling the expression of biosynthetic gene clusters (BGCs) encoding secondary metabolites. In this context this review highlights recent progress in the use and integration of 'omics' approaches with focuses on genomics, transcriptomics, proteomics metabolomics meta-omics and combined omics as powerful strategy to discover new antibiotics. Copyright © 2018 Elsevier Ltd. All rights reserved.

Antimicrobial activity of secondary metabolites from Streptomyces sp. K15, an endophyte in Houttuynia cordata Thunb.

PubMed

Chen, Huabao; Yang, Chunping; Ke, Tao; Zhou, Miaomiao; Li, Zhaojun; Zhang, Min; Gong, Guoshu; Hou, Taiping

2015-01-01

We isolated Streptomyces sp. K15 from the root tissue of Houttuynia cordata Thunb and found that some of its secondary metabolites exhibited significant antimicrobial activity against Botrytis cinerea. Moreover, we separated, purified and identified the major active ingredient to be 2-pyrrol formic acid by using silica gel column chromatography, high-performance liquid chromatography and NMR analysis of the spectral data. 2-Pyrrol formic acid critically inhibited the growth of some phytopathogenic bacteria. Therefore, it has potential value in agricultural applications.

Bioactive Secondary Metabolites Produced by the Fungal Endophytes of Conifers.

PubMed

Stierle, Andrea A; Stierle, Donald B

2015-10-01

This is a review of bioactive secondary metabolites isolated from conifer-associated endophytic fungi from 1990-2014. This includes compounds with antimicrobial, anti-inflammatory, anti-proliferative and cytotoxic activity towards human cancer cell lines, and activity against either plant pathogens or plant insect pests. Compounds that were originally reported without associated activity were included if other studies ascribed activity to these compounds. Compounds were not included if they were exclusively phytotoxic or if they were isolated from active extracts but were not determined to be the active component of that extract.

Genomic mutational analysis of the impact of the classical strain improvement program on β-lactam producing Penicillium chrysogenum.

PubMed

Salo, Oleksandr V; Ries, Marco; Medema, Marnix H; Lankhorst, Peter P; Vreeken, Rob J; Bovenberg, Roel A L; Driessen, Arnold J M

2015-11-14

Penicillium chrysogenum is a filamentous fungus that is employed as an industrial producer of β-lactams. The high β-lactam titers of current strains is the result of a classical strain improvement program (CSI) starting with a wild-type like strain more than six decades ago. This involved extensive mutagenesis and strain selection for improved β-lactam titers and growth characteristics. However, the impact of the CSI on the secondary metabolism in general remains unknown. To examine the impact of CSI on secondary metabolism, a comparative genomic analysis of β-lactam producing strains was carried out by genome sequencing of three P. chrysogenum strains that are part of a lineage of the CSI, i.e., strains NRRL1951, Wisconsin 54-1255, DS17690, and the derived penicillin biosynthesis cluster free strain DS68530. CSI has resulted in a wide spread of mutations, that statistically did not result in an over- or underrepresentation of specific gene classes. However, in this set of mutations, 8 out of 31 secondary metabolite genes (20 polyketide synthases and 11 non-ribosomal peptide synthetases) were targeted with a corresponding and progressive loss in the production of a range of secondary metabolites unrelated to β-lactam production. Additionally, key Velvet complex proteins (LeaA and VelA) involved in global regulation of secondary metabolism have been repeatedly targeted for mutagenesis during CSI. Using comparative metabolic profiling, the polyketide synthetase gene cluster was identified that is responsible for sorbicillinoid biosynthesis, a group of yellow-colored metabolites that are abundantly produced by early production strains of P. chrysogenum. The classical industrial strain improvement of P. chrysogenum has had a broad mutagenic impact on metabolism and has resulted in silencing of specific secondary metabolite genes with the concomitant diversion of metabolism towards the production of β-lactams.

Microbial biosurfactants with their high-value functional properties

USDA-ARS?s Scientific Manuscript database

Microbial world is a rich source for finding valuable industrial chemicals and ingredients. Specifically, many microbial metabolites are surface-active compounds that can be developed into bio-based surfactants, detergents, and emulsifiers. Techno-economic analyses for the production of bio-based ...

Genome, transcriptome, and functional analyses of Penicillium expansum provide new insights into secondary metabolism and pathogenicity

USDA-ARS?s Scientific Manuscript database

The relationship between secondary metabolism and infection in pathogenic fungi has remained largely elusive. Penicillium comprises a group of plant pathogens with varying host specificities and with the ability to produce a wide array of secondary metabolites. The genomes of three Penicillium exp...

A novel fungal metabolite with beneficial properties for agricultural applications.

PubMed

Vinale, Francesco; Manganiello, Gelsomina; Nigro, Marco; Mazzei, Pierluigi; Piccolo, Alessandro; Pascale, Alberto; Ruocco, Michelina; Marra, Roberta; Lombardi, Nadia; Lanzuise, Stefania; Varlese, Rosaria; Cavallo, Pierpaolo; Lorito, Matteo; Woo, Sheridan L

2014-07-08

Trichoderma are ubiquitous soil fungi that include species widely used as biocontrol agents in agriculture. Many isolates are known to secrete several secondary metabolites with different biological activities towards plants and other microbes. Harzianic acid (HA) is a T. harzianum metabolite able to promote plant growth and strongly bind iron. In this work, we isolated from the culture filtrate of a T. harzianum strain a new metabolite, named isoharzianic acid (iso-HA), a stereoisomer of HA. The structure and absolute configuration of this compound has been determined by spectroscopic methods, including UV-Vis, MS, 1D and 2D NMR analyses. In vitro applications of iso-HA inhibited the mycelium radial growth of Sclerotinia sclerotiorum and Rhizoctonia solani. Moreover, iso HA improved the germination of tomato seeds and induced disease resistance. HPLC-DAD experiments showed that the production of HA and iso HA was affected by the presence of plant tissue in the liquid medium. In particular, tomato tissue elicited the production of HA but negatively modulated the biosynthesis of its analogue iso-HA, suggesting that different forms of the same Trichoderma secondary metabolite have specific roles in the molecular mechanism regulating the Trichoderma plant interaction.

A search for antiplasmodial metabolites among fungal endophytes of terrestrial and marine plants of southern India.

PubMed

Kaushik, Naveen Kumar; Murali, Thokur Sreepathy; Sahal, Dinkar; Suryanarayanan, T S

2014-10-01

Eighty four different fungal endophytes isolated from sea grasses (5), marine algae (36) and leaves or barks of forest trees (43) were grown in vitro and the secondary metabolites secreted by them were harvested by immobilizing them on XAD beads. These metabolites were eluted with methanol and screened using SYBR Green I assay for their antiplasmodial activity against blood stage Plasmodium falciparum in human red blood cell culture. Our results revealed that fungal endophytes belonging to diverse genera elaborate antiplasmodial metabolites. A Fusarium sp. (580, IC50: 1.94 μg ml(-1)) endophytic in a marine alga and a Nigrospora sp. (151, IC50: 2.88 μg ml(-1)) endophytic in a tree species were subjected to antiplasmodial activity-guided reversed phase high performance liquid chromatography separation. Purification led to potentiation as reflected in IC50 values of 0.12 μg ml(-1) and 0.15 μg ml(-1) for two of the fractions obtained from 580. Our study adds further credence to the notion that fungal endophytes are a potential storehouse for a variety of novel secondary metabolites vested with different bioactivities including some that can stall the growth of the malaria parasite.

Posaconazole (Noxafil, SCH 56592), a new azole antifungal drug, was a discovery based on the isolation and mass spectral characterization of a circulating metabolite of an earlier lead (SCH 51048).

PubMed

Nomeir, Amin A; Pramanik, Birendra N; Heimark, Larry; Bennett, Frank; Veals, John; Bartner, Peter; Hilbert, Maryjane; Saksena, Anil; McNamara, Paul; Girijavallabhan, Viyyoor; Ganguly, Ashit K; Lovey, Raymond; Pike, Russell; Wang, Haiyan; Liu, Yi-Tsung; Kumari, Pramila; Korfmacher, Walter; Lin, Chin-Chung; Cacciapuoti, Anthony; Loebenberg, David; Hare, Roberta; Miller, George; Pickett, Cecil

2008-04-01

Posaconazole (SCH 56592) is a novel triazole antifungal drug that is marketed in Europe and the United States under the trade name 'Noxafil' for prophylaxis against invasive fungal infections. SCH 56592 was discovered as a possible active metabolite of SCH 51048, an earlier lead. Initial studies have shown that serum concentrations determined by a microbiological assay were higher than those determined by HPLC from animals dosed with SCH 51048. Subsequently, several animals species were dosed with (3)H-SCH 51048 and the serum was analyzed for total radioactivity, SCH 51048 concentration and antifungal activity. The antifungal activity was higher than that expected based on SCH 51048 serum concentrations, confirming the presence of active metabolite(s). Metabolite profiling of serum samples at selected time intervals pinpointed the peak that was suspected to be the active metabolite. Consequently, (3)H-SCH 51048 was administered to a large group of mice, the serum was harvested and the metabolite was isolated by extraction and semipreparative HPLC. LC-MS/MS analysis suggested that the active metabolite is a secondary alcohol with the hydroxyl group in the aliphatic side chain of SCH 51048. All corresponding monohydroxylated diastereomeric mixtures were synthesized and characterized. The HPLC retention time and LC-MS/MS spectra of the diastereomeric secondary alcohols of SCH 51048 were similar to those of the isolated active metabolite. Finally, all corresponding individual monohydroxylated diasteriomers were synthesized and evaluated for in vitro and in vivo antifungal potencies, as well as pharmacokinetics. SCH 56592 emerged as the candidate with the best overall profile.

Secondary metabolites extracted from marine sponge associated Comamonas testosteroni and Citrobacter freundii as potential antimicrobials against MDR pathogens and hypothetical leads for VP40 matrix protein of Ebola virus: an in vitro and in silico investigation.

PubMed

Skariyachan, Sinosh; Acharya, Archana B; Subramaniyan, Saumya; Babu, Sumangala; Kulkarni, Shruthi; Narayanappa, Rajeswari

2016-09-01

The current study explores therapeutic potential of metabolites extracted from marine sponge (Cliona sp.)-associated bacteria against MDR pathogens and predicts the binding prospective of probable lead molecules against VP40 target of Ebola virus. The metabolite-producing bacteria were characterized by agar overlay assay and as per the protocols in Bergey's manual of determinative bacteriology. The antibacterial activities of extracted metabolites were tested against clinical pathogens by well-diffusion assay. The selected metabolite producers were characterized by 16S rDNA sequencing. Chemical screening and Fourier Transform Infrared (FTIR) analysis for selected compounds were performed. The probable lead molecules present in the metabolites were hypothesized based on proximate analysis, FTIR data, and literature survey. The drug-like properties and binding potential of lead molecules against VP40 target of Ebola virus were hypothesized by computational virtual screening and molecular docking. The current study demonstrated that clear zones around bacterial colonies in agar overlay assay. Antibiotic sensitivity profiling demonstrated that the clinical isolates were multi-drug resistant, however; most of them showed sensitivity to secondary metabolites (MIC-15 μl/well). The proximate and FTIR analysis suggested that probable metabolites belonged to alkaloids with O-H, C-H, C=O, and N-H groups. 16S rDNA characterization of selected metabolite producers demonstrated that 96% and 99% sequence identity to Comamonas testosteroni and Citrobacter freundii, respectively. The docking studies suggested that molecules such as Gymnastatin, Sorbicillactone, Marizomib, and Daryamide can designed as probable lead candidates against VP40 target of Ebola virus.

Non-targeted metabolite profiling of citrus juices as a tool for variety discrimination and metabolite flow analysis.

PubMed

Arbona, Vicent; Iglesias, Domingo J; Gómez-Cadenas, Aurelio

2015-02-05

Genetic diversity of citrus includes intrageneric hybrids, cultivars arising from cross-pollination and/or somatic mutations with particular biochemical compounds such as sugar, acids and secondary metabolite composition. Secondary metabolite profiles of juices from 12 commercial varieties grouped into blonde and navel types, mandarins, lemons and grapefruits were analyzed by LC/ESI-QTOF-MS. HCA on metabolite profiling data revealed the existence of natural groups demarcating fruit types and varieties associated to specific composition patterns. The unbiased classification provided by HCA was used for PLS-DA to find the potential variables (mass chromatographic features) responsible for the classification. Abscisic acid and derivatives, several flavonoids and limonoids were identified by analysis of mass spectra. To facilitate interpretation, metabolites were represented as flow charts depicting biosynthetic pathways. Mandarins 'Fortune' and 'Hernandina' along with oranges showed higher ABA contents and ABA degradation products were present as glycosylated forms in oranges and certain mandarins. All orange and grapefruit varieties showed high limonin contents and its glycosylated form, that was only absent in lemons. The rest of identified limonoids were highly abundant in oranges. Particularly, Sucrenya cultivar showed a specific accumulation of obacunone and limonoate A-ring lactone. Polymethoxylated flavanones (tangeritin and isomers) were absolutely absent from lemons and grapefruits whereas kaempferol deoxyhexose hexose isomer #2, naringin and neohesperidin were only present in these cultivars. Analysis of relative metabolite build-up in closely-related genotypes allowed the efficient demarcation of cultivars and suggested the existence of genotype-specific regulatory mechanisms underlying the differential metabolite accumulation.

Cyclic Lipopeptides of Bacillus amyloliquefaciens subsp. plantarum Colonizing the Lettuce Rhizosphere Enhance Plant Defense Responses Toward the Bottom Rot Pathogen Rhizoctonia solani.

PubMed

Chowdhury, Soumitra Paul; Uhl, Jenny; Grosch, Rita; Alquéres, Sylvia; Pittroff, Sabrina; Dietel, Kristin; Schmitt-Kopplin, Philippe; Borriss, Rainer; Hartmann, Anton

2015-09-01

The commercially available inoculant Bacillus amyloliquefaciens FZB42 is able to considerably reduce lettuce bottom rot caused by Rhizoctonia solani. To understand the interaction between FZB42 and R. solani in the rhizosphere of lettuce, we used an axenic system with lettuce bacterized with FZB42 and inoculated with R. solani. Confocal laser scanning microscopy showed that FZB42 could delay the initial establishment of R. solani on the plants. To show which secondary metabolites of FZB42 are produced under these in-situ conditions, we developed an ultra-high performance liquid chromatography coupled to time of flight mass spectrometry-based method and identified surfactin, fengycin, and bacillomycin D in the lettuce rhizosphere. We hypothesized that lipopeptides and polyketides play a role in enhancing the plant defense responses in addition to the direct antagonistic effect toward R. solani and used a quantitative real-time polymerase chain reaction-based assay for marker genes involved in defense signaling pathways in lettuce. A significant higher expression of PDF 1.2 observed in the bacterized plants in response to subsequent pathogen challenge showed that FZB42 could enhance the lettuce defense response toward the fungal pathogen. To identify if surfactin or other nonribosomally synthesized secondary metabolites could elicit the observed enhanced defense gene expression, we examined two mutants of FZB42 deficient in production of surfactin and the lipopetides and polyketides, by expression analysis and pot experiments. In the absence of surfactin and other nonribosomally synthesized secondary metabolites, there was no enhanced PDF 1.2-mediated response to the pathogen challenge. Pot experiment results showed that the mutants failed to reduce disease incidence in lettuce as compared with the FZB42 wild type, indicating, that surfactin as well as other nonribosomally synthesized secondary metabolites play a role in the actual disease suppression and on lettuce health. In conclusion, our study showed that nonribosomally synthesized secondary metabolites of FZB42 are actually produced in the lettuce rhizosphere and contribute to the disease suppression by mediating plant defense gene expression toward the pathogen R. solani.

Clearing the skies over modular polyketide synthases.

PubMed

Sherman, David H; Smith, Janet L

2006-09-19

Modular polyketide synthases (PKSs) are large multifunctional proteins that synthesize complex polyketide metabolites in microbial cells. A series of recent studies confirm the close protein structural relationship between catalytic domains in the type I mammalian fatty acid synthase (FAS) and the basic synthase unit of the modular PKS. They also establish a remarkable similarity in the overall organization of the type I FAS and the PKS module. This information provides important new conclusions about catalytic domain architecture, function, and molecular recognition that are essential for future efforts to engineer useful polyketide metabolites with valuable biological activities.

Utilization of a deuterated derivatization agent to synthesize internal standards for gas chromatography-tandem mass spectrometry quantification of silylated metabolites.

PubMed

Lien, Stina K; Kvitvang, Hans Fredrik Nyvold; Bruheim, Per

2012-07-20

GC-MS analysis of silylated metabolites is a sensitive method that covers important metabolite groups such as sugars, amino acids and non-amino organic acids, and it has become one of the most important analytical methods for exploring the metabolome. Absolute quantitative GC-MS analysis of silylated metabolites poses a challenge as different metabolites have different derivatization kinetics and as their silyl-derivates have varying stability. This report describes the development of a targeted GC-MS/MS method for quantification of metabolites. Internal standards for each individual metabolite were obtained by derivatization of a mixture of standards with deuterated N-methyl-N-trimethylsilyltrifluoroacetamide (d9-MSTFA), and spiking this solution into MSTFA derivatized samples prior to GC-MS/MS analysis. The derivatization and spiking protocol needed optimization to ensure that the behaviour of labelled compound responses in the spiked sample correctly reflected the behaviour of unlabelled compound responses. Using labelled and unlabelled MSTFA in this way enabled normalization of metabolite responses by the response of their deuterated counterpart (i.e. individual correction). Such individual correction of metabolite responses reproducibly resulted in significantly higher precision than traditional data correction strategies when tested on samples both with and without serum and urine matrices. The developed method is thus a valuable contribution to the field of absolute quantitative metabolomics. Copyright © 2012 Elsevier B.V. All rights reserved.

Rhizophagus irregularis as an elicitor of rosmarinic acid and antioxidant production by transformed roots of Ocimum basilicum in an in vitro co-culture system.

PubMed

Srivastava, Shivani; Conlan, Xavier A; Cahill, David M; Adholeya, Alok

2016-11-01

Arbuscular mycorrhiza is a symbiotic association formed between plant roots and soil borne fungi that alter and at times improve the production of secondary metabolites. Detailed information is available on mycorrhizal development and its influence on plants grown under various edapho-climatic conditions, however, very little is known about their influence on transformed roots that are rich reserves of secondary metabolites. This raises the question of how mycorrhizal colonization progresses in transformed roots grown in vitro and whether the mycorrhizal fungus presence influences the production of secondary metabolites. To fully understand mycorrhizal ontogenesis and its effect on root morphology, root biomass, total phenolics, rosmarinic acid, caffeic acid and antioxidant production under in vitro conditions, a co-culture was developed between three Agrobacterium rhizogenes-derived, elite-transformed root lines of Ocimum basilicum and Rhizophagus irregularis. We found that mycorrhizal ontogenesis in transformed roots was similar to mycorrhizal roots obtained from an in planta system. Mycorrhizal establishment was also found to be transformed root line-specific. Colonization of transformed roots increased the concentration of rosmarinic acid, caffeic acid and antioxidant production while no effect was observed on root morphological traits and biomass. Enhancement of total phenolics and rosmarinic acid in the three mycorrhizal transformed root lines was found to be transformed root line-specific and age dependent. We reveal the potential of R. irregularis as a biotic elicitor in vitro and propose its incorporation into commercial in vitro secondary metabolite production via transformed roots.

Geographic variation in feeding preference of a generalist herbivore: the importance of seaweed chemical defenses.

PubMed

McCarty, Amanda T; Sotka, Erik E

2013-08-01

The ecological impacts of generalist herbivores depend on feeding preferences, which can vary across and within herbivore species. Among mesoherbivores, geographic variation in host use can occur because host plants have a more restricted geographic distribution than does the herbivore, or there is local evolution in host preference, or both. We tested the role of local evolution using the marine amphipod Ampithoe longimana by rearing multiple amphipod populations from three regions (subtropical Florida, warm-temperate North Carolina and cold-temperate New England) and assaying their feeding preferences toward ten seaweeds that occur in some but not all regions. Six of the ten seaweeds produce anti-herbivore secondary metabolites, and we detected geographic variation in feeding preference toward five (Dictyota menstrualis, Dictyota ciliolata, Fucus distichus, Chondrus crispus and Padina gymnospora, but not Caulerpa sertularioides). Amphipod populations that co-occur with a chemically-rich seaweed tended to have stronger feeding preferences for that seaweed, relative to populations that do not co-occur with the seaweed. A direct test indicated that geographic variation in feeding preference toward one seaweed (D. ciliolata) is mediated by feeding tolerance for lipophilic secondary metabolites. Among the four seaweeds that produce no known secondary metabolites (Acanthophora, Ectocarpus, Gracilaria and Hincksia/Feldmannia spp.), we detected no geographic variation in feeding preference. Thus, populations are more likely to evolve greater feeding preferences for local hosts when those hosts produce secondary metabolites. Microevolution of feeding behaviors of generalist marine consumers likely depends on the availability and identity of local hosts and the strength of their chemical defenses.

RATE AND CAPACITY OF HEPATIC MICROSOMAL RING HYDROXYLATION OF PHENOL TO HYDROQUINONE AND CATECHOL IN RAINBOW TROUT

EPA Science Inventory

Rainbow trout (Oncorhynchus mykiss) liver microsomes were used to study the rate of ring-hydroxylation of phenol PH) by directly measuring the production of hydroquinone (HQ), the primary metabolite, and catechol (CAT), a secondary metabolite. An HPLC method with integrated ultra...