An endophytic Streptomyces sp. strain DHV3-2 from diseased root as a potential biocontrol agent against Verticillium dahliae and growth elicitor in tomato (Solanum lycopersicum).

PubMed

Cao, Peng; Liu, Chongxi; Sun, Pengyu; Fu, Xuepeng; Wang, Shaoxian; Wu, Fengzhi; Wang, Xiangjing

2016-12-01

Plant endophytes play important roles in biocontrol of plant diseases. Actinomycetes are used for biocontrol of fungal diseases caused by Verticillium dahliae. Many studies have focused on the endophytic actinomycetes isolated from the roots of healthy plants, but few on those from the roots of diseased plants. In the present research, actinomycetes were isolated from the roots of diseased and healthy tomato plants, respectively. The results showed that, in total, 86 endophytic actinomycetes were isolated for screening of their antimicrobial activities, 8 of which showed antagonism to V. dahliae in vitro. Among the 8 antagonistic strains, 5 (out of 36) were from the roots of diseased plants, with inhibition diameter zones ranging from 11.2 to 18.2 mm, whereas 3 (out of 50) were from the roots of healthy plants, with inhibition diameter zones ranging from 11.5 to 15.5 mm. Endophytic strain DHV3-2 was isolated from the root of a diseased plant and demonstrated a potent effect against V. dahliae and other pathogenic fungi by showing the largest inhibition diameter zones among all the eight antagonistic strains. Thus, strain DHV3-2 was chosen to investigate its biological control efficacies in vivo. Further study showed that the disease incidence and disease severity indices of tomato Verticillium wilt decreased significantly (P < 0.05). We also found that the plant shoot fresh weight and height increased greatly (P < 0.05) upon treatment with strain DHV3-2 compared to the plants uninoculated in greenhouse conditions. Root colonization showed that strain DHV3-2 had the higher root-colonizing capacity in the roots of infected plants compared with the roots of healthy plants. This isolate was identified as Streptomyces sp. based on morphological characteristics and 16S rRNA gene analysis. In conclusion, the roots of diseased tomato plants are a potential reservoir of biological control actinomycetes, and Streptomyces sp. strain DHV3-2 is a potential biocontrol

Rare actinomycetes Nocardia caishijiensis and Pseudonocardia carboxydivorans as endophytes, their bioactivity and metabolites evaluation.

PubMed

Tanvir, Rabia; Sajid, Imran; Hasnain, Shahida; Kulik, Andreas; Grond, Stephanie

2016-04-01

Two strains identified as Nocardia caishijiensis (SORS 64b) and Pseudonocardia carboxydivorans (AGLS 2) were isolated as endophytes from Sonchus oleraceus and Ageratum conyzoides respectively. The analysis of their extracts revealed them to be strongly bioactive. The N. caishijiensis extract gave an LC50 of 570 μg/ml(-1) in the brine shrimp cytotoxicity assay and an EC50 of 0.552 μg/ml(-1) in the DPPH antioxidant assay. Antimicrobial activity was observed against Methicillin resistant Staphlococcus aureus (MRSA) and Escherichia coli ATCC 25922 (14 mm), Klebsiella pneumoniae ATCC 706003 (13 mm), S. aureus ATCC 25923 (11 mm) and Candida tropicalis (20 mm). For the extract of P. carboxydivorans the EC50 was 0.670 μg/ml(-1) and it was observed to be more bioactive against Bacillus subtilis DSM 10 ATCC 6051 (21 mm), C. tropicalis (20 mm), S. aureus ATCC 25923 (17 mm), MRSA (17 mm), E. coli K12 (W1130) (16 mm) and Chlorella vulgaris (10 mm). The genotoxicity testing revealed a 20 mm zone of inhibition against the polA mutant strain E. coli K-12 AB 3027 suggesting damage to the DNA and polA genes. The TLC and bioautography screening revealed a diversity of active bands of medium polar and nonpolar compounds. Metabolite analysis by HPLC-DAD via UV/vis spectral screening suggested the possibility of stenothricin and bagremycin A in the mycelium extract of N. caishijiensis respectively. In the broth and mycelium extract of P. carboxydivorans borrelidin was suggested along with α-pyrone. The HPLC-MS revealed bioactive long chained amide derivatives such as 7-Octadecenamide, 9, 12 octadecandienamide. This study reports the rare actinomycetes N. caishijiensis and P. carboxydivorans as endophytes and evaluates their bioactive metabolites. Copyright © 2016 Elsevier GmbH. All rights reserved.

[Isolation and antimicrobial activities of actinomycetes from vermicompost].

PubMed

Wang, Xue-jun; Yan, Shuang-lin; Min, Chang-li; Yang, Yan

2015-02-01

In this paper, actinomycetes were isolated from vermicompost by tablet coating method. Antimicrobial activities of actinomycetes were measured by the agar block method. Strains with high activity were identified based on morphology and biochemical characteristics, as well as 16S rDNA gene sequence analysis. The results showed that 26 strains of actinomycetes were isolated, 16 of them had antimicrobial activities to the test strains which accounts for 61.54% of all strains. Among the 16 strains, the strain QYF12 and QYF22 had higher antimicrobial activity to Micrococcus luteus, with a formed inhibition zone of 27 mm and 31 mm, respectively. While the strain QYF26 had higher antimicrobial activity to Bacillus subtilis, and the inhibition zone diameter was 21 mm. Based on the identification of strains with high activity, the strain QYF12 was identified as Streptomyces chartreusis, the strain QYF22 was S. ossamyceticus and the strain QYF26 was S. gancidicus. This study provided a theoretical basis for further separate antibacterial product used for biological control.

Isolation, Phylogenetic Analysis and Anti-infective Activity Screening of Marine Sponge-Associated Actinomycetes

PubMed Central

Abdelmohsen, Usama Ramadan; Pimentel-Elardo, Sheila M.; Hanora, Amro; Radwan, Mona; Abou-El-Ela, Soad H.; Ahmed, Safwat; Hentschel, Ute

2010-01-01

Terrestrial actinomycetes are noteworthy producers of a multitude of antibiotics, however the marine representatives are much less studied in this regard. In this study, 90 actinomycetes were isolated from 11 different species of marine sponges that had been collected from offshore Ras Mohamed (Egypt) and from Rovinj (Croatia). Phylogenetic characterization of the isolates based on 16S rRNA gene sequencing supported their assignment to 18 different actinomycete genera representing seven different suborders. Fourteen putatively novel species were identified based on sequence similarity values below 98.2% to other strains in the NCBI database. A putative new genus related to Rubrobacter was isolated on M1 agar that had been amended with sponge extract, thus highlighting the need for innovative cultivation protocols. Testing for anti-infective activities was performed against clinically relevant, Gram-positive (Enterococcus faecalis, Staphylococcus aureus) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria, fungi (Candida albicans) and human parasites (Leishmania major, Trypanosoma brucei). Bioactivities against these pathogens were documented for 10 actinomycete isolates. These results show a high diversity of actinomycetes associated with marine sponges as well as highlight their potential to produce anti-infective agents. PMID:20411105

[Isolation and physiological characteristics of endophytic actinobacteria from medicinal plants].

PubMed

Du, Huijing; Su, Jing; Yu, Liyan; Zhang, Yuqin

2013-01-04

To isolate, incubate and characterize cultivable endophytic antinobacteria from medicinal plants, and analyze the diversity of the endophytic antinobacteria, then explore the novel microbial resources. Ten media were used to isolate endophytic antinobacteria from 37 fresh medicinal plant tissue samples. The optimal cultivation conditions for endophytic antinobacteria were determined by comparison. Based on the morphology of the colonies and cells of the new isolates, we chose 174 isolates to analyze their 16S rRNA gene sequences and the diversity of the medicinal plant endophytic antinobacteria. The physiological characteristics of 27 representative strains were studied using Biolog GEN III MicroPlates, API 50CH and API ZYM kits. In total 940 endophytics affiliated to 47 genera of 30 families were isolated, among which more than 600 actinobacteria belonged to 34 genera and 7 unknown taxa. Good growth of the endophytic antinobacteria on PYG (peptone-yeast-glycerol) medium with pH 7.2 at 28-32 degrees C was observed. Physiological characteristics differences of these isolates related to their phylogenetic relationships. Greater differences were shown among the strains from the same host plants than those from differ,ent plants grown in the same area. There are great diverse endophytic actinobacteria inside the medicinal plants. No direct relationship of the endophytic actinobacteria from medicinal plants with the host plants in the sole carbon source utilization, fermentation of carbon sources to produce acid and the enzyme activities was found, while it seemed that the physiological characteristics of the isolates related to the geographical distribution of their host.

Studies on L-asparaginase enzyme of actinomycetes isolated from estuarine fishes.

PubMed

Sahu, Maloy Kumar; Sivakumar, K; Poorani, E; Thangaradjou, T; Kannan, L

2007-04-01

Actinomycetes were isolated from different organs viz. skin, gills and gut contents of three species of fishes viz. Mugil cephalus (Linnaeus, 1758), Chanos chanos (Forskal, 1775) and Etroplus suratensis (Bloch, 1780) using three different media from the Vellar estuary, situated along the southeast coast of India. Among the three fishes, M. cephalus harboured highest number of actinomycetes population in all the three body parts examined followed by C. chanos and E. suratensis. Out of the three body parts of all fishes, gut contents had highest actinomycetes population followed by gills and skin. Among the three media used for isolation of actinomycetes, Kuster's agar medium was found to be suitable than the starch casein agar and glucose asparagine agar media. Out of the 40 strains isolated, only six strains (LA-2, LA-8, LA-15, LA-20, LA-29 and LA-35) showed significant L-asparagianse activity and were taken up for further studies. Impact of various physical and chemical factors such as pH, temperature, sodium chloride concentration, carbon sources and amino acids on the growth of actinomycetes and L-asparaginase activity was also studied. Optimum growth and enzyme activity was noticed under pH 7 to 8, temperature 37 degrees C, 1-2% sodium chloride concentration, sucrose as carbon source and without any amino acids. Analysis of the cell components of the isolated strains has revealed the wall type-I (the wall type-I is typical for the genus Streptomyces) and the strains were micromorphologically similar to the genus Streptomyces. Hence, the morphological, physiological and biochemical along with the micromorphological results obtained for the L-asparaginase producing strains were compared and the strains were tentatively identified as Streptomyces aureofasciculus (LA-2), S. chattanoogenesis (LA-8), S. hawaiiensis (LA-15), S. orientalis (LA-20), S. canus (LA-29) and S. olivoviridis (LA-35).

Antitumour and antimicrobial activities of endophytic streptomycetes from pharmaceutical plants in rainforest.

PubMed

Li, J; Zhao, G-Z; Chen, H-H; Wang, H-B; Qin, S; Zhu, W-Y; Xu, L-H; Jiang, C-L; Li, W-J

2008-12-01

The aim of this study was to screen antitumour and antimicrobial activities of endophytic actinomycetes isolated from pharmaceutical plants in rainforest in Yunnan province, China. Antitumour activity was studied by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and antimicrobial activity was determined by agar well diffusion method. The high bioactive endophytic isolates were identified and further investigated for the presence of polyketide synthases (PKS-I, PKS-II) and nonribosomal peptide synthetases (NRPS) sequences by specific amplification. The molecular identification confirmed that the 41 isolates showed significant activities were members of the genus Streptomyces. Among them, 31.7% of endophytic streptomycete cultures were cytotoxic against A549 cells, 29.3% against HL-60 cells, 85.4% against BEL-7404 cells, 90.2% against P388D1 cells, 65.9% were active against Escherichia coli, 24.4% against Staphylococcus aureus, 31.7% against Staphylococcus epidermidis, 12.2% against Candida albicans and no strain displayed antagonistic activity against Klebsiella pneumoniae. High frequencies of positive PCR amplification were obtained for PKS-I (34.1%), PKS-II (63.4%) and NRPS (61.0%) biosynthetic systems. Many endophytic streptomycetes isolated from pharmaceutical plants in rainforest possess remarkable and diverse antitumour and antimicrobial bioactivities. These endophytic streptomycetes are precious resources obtained from rainforests, and they could be a promising source for bioactive agents.

Isolation and functional characterization of bacterial endophytes from Carica papaya fruits.

PubMed

Krishnan, P; Bhat, R; Kush, A; Ravikumar, P

2012-08-01

To isolate and characterize the endophytes from papaya fruits and to determine the fermentative potential of the strains. Endophytes provide potential sources for novel natural products for the use in agriculture and nutrition. There is very limited information on isolation and characterization of bacterial endophytes from papaya. We describe isolation and characterization of eighteen endophytes of papaya fruit from four economically important papaya varieties viz 'Red lady', 'Solo', 'Coorg Honey' and 'Bangalore'. The phylogenetic analysis based on the 16S rRNA sequence revealed that isolated endophytes are genetically distinct and cluster as discrete clades in the dendrogram. The Bacillus species is a predominant bacterial endophyte across papaya varieties. The seeds and the endocarp of papaya fruits harbour Kocuria, Acinetobacter and Enterobacter species. The Staphylococcus species were detected in the fruit mesocarp of two papaya varieties used in the study. The endophytes isolated from papaya fruits were capable of producing extracellular enzymes like amylase, cellulase, pectinase and xylanase. Three isolates, Bacillus (PE-LR-1 and PE-LR-3) and Kocuria (PE-LR-2), were selected for fruit fermentation, and antioxidant potential of the fermented product was evaluated. PE-LR-3 fermented product has the free radical scavenging activity of 61·2% and a microbial cocktail of PE-LR-3 with Saccharomyces cerevisiae MTCC 2918 enhances the antioxidant potential to 75·7%. These findings suggest that different parts of papaya fruits harbour an array of bacterial endophytes that could be important agents in attributing the high nutritive status to the fruit and can serve as potent microbial cocktails for developing value-added fermented products of this important fruit. This study describes isolation of a bacterial endophyte from papaya fruit that is capable of improving the antioxidant potential of raw papaya after fermentation. No claim to Indian Government works Journal

Transformation of 2,4,6-trinitrotoluene (TNT) by actinomycetes isolated from TNT-contaminated and uncontaminated environments.

PubMed Central

Pasti-Grigsby, M B; Lewis, T A; Crawford, D L; Crawford, R L

1996-01-01

Actinomycete strains isolated from 2,4,6-trinitrotoluene (TNT)-contaminated and uncontaminated environments were compared for TNT tolerance and abilities to transform TNT. Regardless of previous TNT exposure history, no significant differences in TNT tolerance were seen among strains. Selected strains did not significantly mineralize [14C]TNT. The actinomycetes did, however, transform TNT into reduced intermediates. The data indicate that, in actinomycete-rich aerobic environments like composts, actinomycetes will transform TNT into intermediates which are known to form recalcitrant polymers. PMID:8975606

[Isolation and diversity analyses of endophytic fungi from Paris polyphylla var. yunnanensis].

PubMed

Wang, Qian; Shen, Shi-Kang; Zhang, Ai-Li; Wu, Chun-Yan; Wu, Fu-Qin; Zhang, Xin-Jun; Wang, Yue-Hua

2013-11-01

The paper is aimed at studying the diversity of endophytic fungi community from Paris polyphylla var. yunnanensis, and to provide a scientific basis for the utilization value of the endophytic fungi as bioactive material resources. In the present study, endophytic fungi were isolated from roots, rhizomes and leaves of wild P. polyphylla var. yunnanensis collected from Baoshan, Heqing county and Songming city of Yunnan province, and identified and classified by morphological methods together with its ITS sequence analysis. Seven and forty-nine strains of endophytic fungi were isolated from P. polyphylla var. yunnanensis. They were identified belonging to 41 genus. In these 41 genus, 3 genus exist in root only, 12 genus only exist in rhizome and 8 genus only exist in leaf. There was difference in endophytic fungi isolated from different sample sites. Endophytic fungi diversity from rhizomes of Heqing site was the highest. Endophytic fungi similarity coefficient was low among different sites and tissues. Based on these results, it is reasonable to propose that endophytic fungi of P. polyphylla var. yannanensis from different tissue and different sample sites has a certain difference which is possibly relate to their different habitats, different structure and composition of each tissue.

A novel method to scale up fungal endophyte isolations

USDA-ARS?s Scientific Manuscript database

Estimations of species diversity are influenced by sampling intensity which in turn is influenced by methodology. For fungal endophyte diversity studies, the methodology includes surface-sterilization prior to isolation of endophytes. Surface-sterilization is an essential component of fungal endophy...

Isolation and identification of actinomycetes for production of novel extracellular glutaminase free L-asparaginase.

PubMed

Saxena, Akansha; Upadhyay, Ramraj; Kango, Naveen

2015-12-01

Over the recent years glutaminase free L-asparaginase has gained more importance due to better therapeutic properties for treatment of acute lymphoblastic leukemia. Actinomycetes are known for L-asparaginase activity. In the current study, 80 actinomycetes were isolated from various soil habitats by serial dilution technique. Presence of L-asparaginase was investigated in a total of 240 actinomycetes by tubed agar method using modified M-9 medium. A total of 165 actinomycetes were found positive for L-asparaginase activity. Among these, 57 actinomycetes producing larger zones of L-asparagine hydrolysis were further screened for their capacity to produce glutaminase-free L-asparaginase. Four L-glutaminase-free actinomycetes were found to be potential L-asparaginase producers. These actinomycetes were identified as Streptomyces cyaneus (SAP 1287, CFS 1560), S. exfoliates (CFS 1557) and S. phaeochromogenes (GS 1573) on the basis of morphological and biochemical identification studies. Maximum L-asparaginase activity (19.2 Uml(-1)) was observed in culture filtrate of S. phaeochromogenes under submerged fermentation. Results indicate that S. phaeochromogenes could be a potential source of glutaminase free L-asparaginase for commercial purpose. To the best of our knowledge, this is the first report on production of glutaminase free L-asparaginase from S. cyaneus, S. exfoliatus and S. phaeochromogenes.

Eliciting antibiotics active against the ESKAPE pathogens in a collection of actinomycetes isolated from mountain soils.

PubMed

Zhu, Hua; Swierstra, Jasper; Wu, Changsheng; Girard, Geneviève; Choi, Young Hae; van Wamel, Willem; Sandiford, Stephanie K; van Wezel, Gilles P

2014-08-01

The rapid emergence of multidrug-resistant (MDR) bacterial pathogens poses a major threat for human health. In recent years, genome sequencing has unveiled many poorly expressed antibiotic clusters in actinomycetes. Here, we report a well-defined ecological collection of >800 actinomycetes obtained from sites in the Himalaya and Qinling mountains, and we used these in a concept study to see how efficiently antibiotics can be elicited against MDR pathogens isolated recently from the clinic. Using 40 different growth conditions, 96 actinomycetes were identified - predominantly Streptomyces - that produced antibiotics with efficacy against the MDR clinical isolates referred to as ESKAPE pathogens: Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and/or Enterobacter cloacae. Antimicrobial activities that fluctuated strongly with growth conditions were correlated with specific compounds, including borrelidin, resistomycin, carbomethoxy-phenazine, and 6,7,8- and 5,6,8-trimethoxy-3-methylisocoumarin, of which the latter was not described previously. Our work provided insights into the potential of actinomycetes as producers of drugs with efficacy against clinical isolates that have emerged recently and also underlined the importance of targeting a specific pathogen. © 2014 The Authors.

Micromonospora taraxaci sp. nov., a novel endophytic actinomycete isolated from dandelion root (Taraxacum mongolicum Hand.-Mazz.).

PubMed

Zhao, Junwei; Guo, Lifeng; He, Hairong; Liu, Chongxi; Zhang, Yuejing; Li, Chuang; Wang, Xiangjing; Xiang, Wensheng

2014-10-01

A novel actinomycete, designated strain NEAU-P5(T), was isolated from dandelion root (Taraxacum mongolicum Hand.-Mazz.). Strain NEAU-P5(T) showed closest 16S rRNA gene sequence similarity to Micromonospora chokoriensis 2-19/6(T) (99.5%), and phylogenetically clustered with Micromonospora violae NEAU-zh8(T) (99.3%), M. saelicesensis Lupac 09(T) (99.0%), M. lupini Lupac 14N(T) (98.8%), M. zeae NEAU-gq9(T) (98.4%), M. jinlongensis NEAU-GRX11(T) (98.3%) and M. zamorensis CR38(T) (97.9%). Phylogenetic analysis based on the gyrB gene sequence also indicated that the isolate clustered with the above type strains except M. violae NEAU-zh8(T). The cell-wall peptidoglycan consisted of meso-diaminopimelic acid and glycine. The major menaquinones were MK-9(H8), MK-9(H6) and MK-10(H2). The phospholipid profile contained diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol. The major fatty acids were C(16:0), iso-C(15:0) and C(17:0). Furthermore, some physiological and biochemical properties and low DNA-DNA relatedness values enabled the strain to be differentiated from members of closely related species. Therefore, it is proposed that strain NEAU-P5(T) represents a novel species of the genus Micromonospora, for which the name Micromonospora taraxaci sp. nov. is proposed. The type strain is NEAU-P5(T) (=CGMCC 4.7098(T) = DSM 45885(T)).

Isolation and identification of bacterial endophytes from grasses along the Oregon coast

USDA-ARS?s Scientific Manuscript database

Bacterial endophytes have been shown to improve abiotic and biotic stress responses in plants. Grasses growing along the Oregon coast are exposed to harsh conditions and may harbor endophytes that enable them to survive and grow under these conditions. Bacterial endophytes were isolated from thirty-...

Endophytic Nocardiopsis sp. from Zingiber officinale with both antiphytopathogenic mechanisms and antibiofilm activity against clinical isolates.

PubMed

Sabu, Rohini; Soumya, K R; Radhakrishnan, E K

2017-06-01

Novel and potential antimicrobial compounds are essential to tackle the frequently emerging multidrug-resistant pathogens and also to develop environment friendly agricultural practices. In the current study, endophytic actinomycetes from rhizome of Zingiber officinale were explored in terms of its diversity and bioactive properties. Fourteen different organisms were isolated, identified and screened for activity against Pythium myriotylum and human clinical pathogens. Among these, Nocardiopsis sp. ZoA1 was found to have highest inhibition with excellent antibacterial effects compared to standard antibiotics. Remarkable antibiofilm property was also shown by the extract of ZoA1. Its antifungal activity against Pythium and other common phytopathogens was also found to be promising as confirmed by scanning electron microscopic analysis. By PCR-based sequence analysis of phz E gene, the organism was confirmed for the genetic basis of phenazine biosynthesis. Further GC-MS analysis of Nocardiopsis sp. revealed the presence of various compounds including Phenol, 2,4-bis (1,1-dimethylethyl) and trans cinnamic acid which can have significant role in the observed result. The current study is the first report on endophytic Nocardiopsis sp. from ginger with promising applications. In vivo treatment of Nocardiopsis sp. on ginger rhizome has revealed its inhibition towards the colonization of P. myriotylum which makes the study to have promises to manage the severe diseases in ginger like rhizome rot.

Isolation and in vitro selection of actinomycetes strains as potential probiotics for aquaculture

PubMed Central

Bernal, Milagro García; Campa-Córdova, Ángel Isidro; Saucedo, Pedro Enrique; González, Marlen Casanova; Marrero, Ricardo Medina; Mazón-Suástegui, José Manuel

2015-01-01

Aim: This study was designed to describe a series of in vitro tests that may aid the discovery of probiotic strains from actinomycetes. Materials and Methods: Actinomycetes were isolated from marine sediments using four different isolation media, followed by antimicrobial activity and toxicity assessment by the agar diffusion method and the hemolysis of human blood cells, respectively. Extracellular enzymatic production was monitored by the hydrolysis of proteins, lipids and carbohydrates. Tolerance to different pH values and salt concentrations was also determined, followed by hydrophobicity analysis and genetic identification of the most promising strains. Results: Five out of 31 isolated strains showed antimicrobial activity against three Vibrio species. Three non-hemolytic strains (N7, RL8 and V4) among these active isolates yielded positive results in hydrophobicity tests and exhibited good growth at salt concentrations ranging from 0% to 10%, except strain RL8, which required a salt concentration >0.6%. Although these strains did not grow at pH<3, they showed different enzymatic activities. Phylogenetic analysis revealed that strains N7 and V4 have more than 99% identity with several Streptomyces species, whereas the closest matches to strain RL8 are Streptomyces panacagri and Streptomyces flocculus, with 98% and 98.2% similarity, respectively. Conclusion: Three actinomycetes strains showing probiotic-like properties were discovered using several in vitro tests that can be easily implemented in different institutions around the world. PMID:27047067

In vitro interaction of actinomycetes isolates with Aspergillus flavus: impact on aflatoxins B1 and B2 production.

PubMed

Verheecke, C; Liboz, T; Darriet, M; Sabaou, N; Mathieu, F

2014-06-01

This work aimed to study the interaction between Actinomycetal isolates and Aspergillus flavus to promote mutual antagonism in contact. Thirty-seven soilborn Streptomyces spp. isolates were chosen as potential candidates. After a 10-day in vitro co-incubation period, 27 isolates respond to the criteria, that is, mutual antagonism in contact. Further aflatoxins B1 and B2 analysis revealed that those 27 isolates reduced aflatoxin B1 residual concentration from 38·6 to 4·4%, depending on the isolate. We selected 12 isolates and tested their capacity to reduce AFB1 in pure culture to start identifying the mechanisms involved in its reduction. AFB1 was reduced by eight isolates. The remaining AFB1 concentration varied between 82·2 and 15·6%. These findings led us to suggest that these eight isolates could be used as biocontrol agents against AFB1 and B2 with low risk of impacting the natural microbial equilibrium. Interaction between Aspergillus flavus and Actinomycetes isolates was conducted in vitro. Actinomycetes isolates having a mutual antagonism in contact with A. flavus were chosen for further aflatoxins production study. This is a new approach based to develop biocontrol against aflatoxins accumulation in maize while respecting natural microbial equilibrium. © 2014 The Society for Applied Microbiology.

Comparison of methods for isolation and enumeration of thermophilic actinomycetes from dust.

PubMed Central

Treuhaft, M W; Arden Jones, M P

1982-01-01

Thermophilic actinomycetes are the primary sensitizing agents in farmer's lung disease. We compared dilution pour-plate and spread-plate methods for their usefulness in enumerating thermophilic actinomycetes in moldy silage dust and evaluated the ability of a nonquantitative gravity settling technique to recover thermophilic actinomycetes from moldy silage. Spread plates and pour plates yielded similar estimates of total thermophiles. Higher counts were observed on spread plates (P less than 0.05) for Thermoactinomyces candidus, Micropolyspora faeni, and Saccharomonospora viridis. M. faeni and S. viridis were less efficient than T. candidus in breaking through the agar of pour plates to form colonies which could be identified. Coefficients of variability were less than 10% for the two methods. The relative proportion of organisms recovered by the settling method correlated well with that recovered on spread plates for M. faeni (r = 0.79), S. viridis (r = 0.88), and Thermomonospora spp. (r = 0.79), but not well for T. candidus (r = 0.28). When sophisticated air-sampling equipment is not available, dilution spread plates of dust washings provide a reproducible method for enumerating a broad range of thermophilic actinomycetes of interest. The gravity settling method is a simple, rapid alternative when isolation is all that is required. PMID:6761363

Micromonospora zeae sp. nov., a novel endophytic actinomycete isolated from corn root (Zea mays L.).

PubMed

Shen, Yue; Zhang, Yuejing; Liu, Chongxi; Wang, Xiangjing; Zhao, Junwei; Jia, Feiyu; Yang, Lingyu; Yang, Deguang; Xiang, Wensheng

2014-11-01

A novel actinomycete, designated strain NEAU-gq9(T), was isolated from corn root (Zea mays L.) and characterized using a polyphasic approach. The organism was found to have morphological and chemotaxonomic characteristics typical of the genus Micromonospora. On the basis of 16S rRNA gene sequence similarity studies, strain NEAU-gq9(T) was most closely related to Micromonospora zamorensis CR38(T) (99.3%), Micromonospora jinlongensis NEAU-GRX11(T) (99.2%), Micromonospora saelicesensis Lupac 09(T) (99.2%), Micromonospora chokoriensis 2-19(6)(T) (98.9%), Micromonospora coxensis 2-30-b(28)(T) (98.6%) and Micromonospora lupini Lupac 14N(T) (98.5%). Phylogenetic analysis based on the 16S rRNA gene and gyrB gene demonstrated that strain NEAU-gq9(T) is a member of the genus Micromonospora and supported the closest phylogenetic relationship to M. zamorensis CR38(T), M. jinlongensis NEAU-GRX11(T), M. saelicesensis Lupac 09(T), M. chokoriensis 2-19(6)(T) and M. lupini Lupac 14N(T). A combination of DNA-DNA hybridization, morphological and physiological characteristics indicated that the novel strain could be readily distinguished from the closest phylogenetic relatives. Therefore, it is proposed that strain NEAU-gq9(T) represents a novel species of the genus Micromonospora, for which the name Micromonospora zeae sp. nov. is proposed. The type strain is NEAU-gq9(T) (=CGMCC 4.7092(T)=DSM 45882(T)).

Enzyme inhibitory metabolites from endophytic Penicillium citrinum isolated from Boswellia sacra.

PubMed

Ali, Sajid; Khan, Abdul Latif; Ali, Liaqat; Rizvi, Tania Shamim; Khan, Sumera Afzal; Hussain, Javid; Hamayun, Muhammad; Al-Harrasi, Ahmed

2017-07-01

Fungal endophytes establish an important niche within the host plant through the secretion of chemical constituents. Isolation of bioactive metabolites could be a vital source for inhibiting the function of enzymes such as α-glucosidase and urease. The present study aimed to elucidate the potential of endophytes associated with Boswellia sacra through bioassay-guided isolation and identification of secondary metabolites with enzyme inhibitory ability. Endophytic fungal strains viz. Penicillium citrinum, P. spinulosum, Fusarium oxysporum, Alternaria alternata and Aspergillus caespitosus were identified through genomic DNA extraction, PCR amplification, sequencing and phylogenetic analysis. The enzymes inhibition analysis of the ethyl acetate extract from pure cultures suggested that P. citrinum possess significantly higher enzyme inhibitory activities compared to other strains. The active strain was subjected to chromatographic isolation and nuclear magnetic resonance methods to identify bioactive compounds. The bioactive extracts resulted in the isolation of 11-oxoursonic acid benzyl ester (1), n-nonane (2), 3-decene-1-ol (3), 2-Hydroxyphenyl acetic acid (4), and Glochidacuminosides A (5). Among pure compound, 11-oxoursonic acid benzyl ester (1) showed significantly higher enzyme inhibition activity compared to other metabolites. Our results suggest that the endophytic microorganism associated with the arid-land tree can offer a rich source of biologically active chemical constituents that could help discover lead drugs for enzyme inhibition.

Glucanase and Chitinase from Some Isolates of Endophytic Fungus Trichoderma spp.

NASA Astrophysics Data System (ADS)

Prasetyawan, Sasangka; Sulistyowati, Lilik; Aulanni'am

2018-01-01

Endophytic fungi are those fungi that are able to grow in plant tissue without causing symptoms of disease. It is thought that these fungi may confer on the host plants degree of resistance to parasitic invasion. Endophytic fungi have been isolated from stem tissue and these fungi are known to be antagonistic to pathogenic fungi. These endophytes produce chitinase and β-1,3-glucanase enzymes. Based on the fact that chitin and β-1,3-glucan are the main skeletal polysaccharides of the cell walls of fungal patogen. The aim of this research is to do potential test on some of isolates of Trichoderma’s endophytic (L-1, L-2, Is-1, Is-2 and Is-7) in the chitinase and β-1,3-glucanase activity in effort to determine endophytic which be chossen to be gene resource for the next research. The gene will be transformed to citrus plant japanese citroen in effort to make citrus plant transgenic resistance to phytopatogenic invasion. The result of this research is endofit namely L-1 is the most potential endophytic fungi with chitinase activities is 4,8 10-2 Unit and glucanase 24,2. 1012 Unit. The addition of chitin and cell wall of phytophtora causes chitinase activity significantly increase, and also addition of laminarin and cell wall of phytophtora makes glucanase activity increase.

[Isolation, identification and characterization of ACC deaminase-containing endophytic bacteria from halophyte Suaeda salsa].

PubMed

Teng, Songshan; Liu, Yanping; Zhao, Lei

2010-11-01

We Isolated and characterized 1-aminocyclopropane-1-carboxylate (ACC) deaminase-containing endophytic bacteria from halophyte Suaeda salsa to understand the interactions between endophytes and halophyte. ACC deaminase-containing endophytic bacteria were isolated from root, stalk and leaf of Suaeda salsa and were identified based on morphological, physiological-biochemical properties, API and 16S rRNA sequence analysis. Isolates were evaluated for their ACC deaminase, antifungal, protease activity, siderophores and phytohormones, such as indole-3-acetic acid, gibberellic acid and abscisic acid production, as well as atmospheric nitrogen fixation and phosphate solubilization. Four ACC deaminase-containing endophytic bacteria strains named as LP11, SS12, TW1 and TW2 were isolated and identified as Pseudomonas oryzihabitans, Pseudomonas sp., Pantoea agglomerans and Pseudomonas putida respectively. All the strains possessed the phosphate-solubilizing ability and could produce siderophores and phytohormones more or less. None of them could fix atmospheric nitrogen or produce protease. Only strain SS12 showed antagonism against two phytopathogenic fungi viz Fusarium oxysporum f. sp. conglutinans and F. oxysporum f. sp. cucumerinum. ACC deaminase-containing endophytic bacteria of Pseudomonas sp. and Pantoea sp. isolated from halophyte Suaeda salsa have abundant biological characteristics related to plant growth promotion, stress homeostasis regulation and biocontrol activity.

Characterization of five fungal endophytes producing Cajaninstilbene acid isolated from pigeon pea [Cajanus cajan (L.) Millsp].

PubMed

Gao, Yuan; Zhao, Jin Tong; Zu, Yuan Gang; Fu, Yu Jie; Wang, Wei; Luo, Meng; Efferth, Thomas

2011-01-01

Five fungal endophytes (K4, K5, K6, K9, K14) producing Cajaninstilbene acid (CSA, 3-hydroxy-4-prenyl-5-methoxystilbene-2-carboxylic acid) were isolated from the roots of pigeon pea [Cajanus cajan (L.) Millsp.]. CSA is responsible for the prominent pharmacological activities in pigeon pea. The amount of CSA in culture solution varied among the five fungal endophytes. K4 produced the highest levels of CSA (1037.13 µg/L) among the endophytes tested after incubation for five days. Both morphological characteristics and molecular methods were used for species identification of fungal endophytes. The five endophytic isolates were characterized by analyzing the internal transcribed spacer (ITS) rRNA and β-tubulin genes. The K4, K5, K9 and K14 strains isolated from pigeon pea roots were found to be closely related to the species Fusarium oxysporum. K6 was identified as Neonectria macrodidym. The present study is the first report on the isolation and identification of fungal endophytes producing CSA in pigeon pea. The study also provides a scientific base for large scale production of CSA.

Heavy metal resistant endophytic fungi isolated from Nypa fruticans in Kuching Wetland National Park

NASA Astrophysics Data System (ADS)

Choo, Jenny; Sabri, Nuraini Binti Mohd; Tan, Daniel; Mujahid, Aazani; Müller, Moritz

2015-06-01

Heavy metal pollution is an environmental issue globally and the aim of this study was to isolate endophytic fungi from mangrove wetlands of Sarawak to assess and test their ability to grow in the presence of various heavy metals (copper (Cu), zinc (Zn), lead (Pb), and chromium (Cr)). Samples of Nypa fruticans were collected from Kuching Wetland National Park (KWNP) for subsequent endophyte isolation. Ninety-three (93) isolates were obtained and assessed and the most resistant isolates (growing at concentrations up to 1000 ppm) were identified using fungal primers ITS 1 and ITS 4. All of the endophytic fungi were identified to be closely related to Pestalotiopsis sp. and this is to our knowledge the first study reporting the ability of Pestalotiopsis sp. to grow at high concentrations of copper, lead, zinc and chromium. Our results highlight the potential of using endophytic fungi for the treatment of heavy metal pollution, for example as biosorbents.

Distribution and Identification of Endophytic Streptomyces Species from Schima wallichii as Potential Biocontrol Agents against Fungal Plant Pathogens.

PubMed

Passari, Ajit K; Mishra, Vineet K; Gupta, Vijai K; Saikia, Ratul; Singh, Bhim P

2016-08-26

The prospective of endophytic microorganisms allied with medicinal plants is disproportionally large compared to those in other biomes. The use of antagonistic microorganisms to control devastating fungal pathogens is an attractive and eco-friendly substitute for chemical pesticides. Many species of actinomycetes, especially the genus Streptomyces, are well known as biocontrol agents. We investigated the culturable community composition and biological control ability of endophytic Streptomyces sp. associated with an ethanobotanical plant Schima wallichi. A total of 22 actinobacterial strains were isolated from different organs of selected medicinal plants and screened for their biocontrol ability against seven fungal phytopathogens. Seven isolates showed significant inhibition activity against most of the selected pathogens. Their identification based on 16S rRNA gene sequence analysis, strongly indicated that all strains belonged to the genus Streptomyces. An endophytic strain BPSAC70 isolated from root tissues showed highest percentage of inhibition (98.3 %) against Fusarium culmorum with significant activity against other tested fungal pathogens. Phylogenetic analysis based on 16S rRNA gene sequences revealed that all seven strains shared 100 % similarity with the genus Streptomyces. In addition, the isolates were subjected to the amplification of antimicrobial genes encoding polyketide synthase type I (PKS-I) and nonribosomal peptide synthetase (NRPS) and found to be present in most of the potent strains. Our results identified some potential endophytic Streptomyces species having antagonistic activity against multiple fungal phytopathogens that could be used as an effective biocontrol agent against pathogenic fungi.

Isolation and characterization of endophytic huperzine A-producing fungi from Huperzia serrata.

PubMed

Wang, Ya; Zeng, Qing Gui; Zhang, Zhi Bin; Yan, Ri Ming; Wang, Ling Yun; Zhu, Du

2011-09-01

Huperzia serrata is a producer of huperzine A (HupA), a cholinesterase inhibitor (ChEI). Over 120 endophytic fungi were recovered from this plant and screened for Hup-A and nine were found. These nine represented seven different fungal genera with the most significant producer being Shiraia sp. A total of 127 endophytic fungi isolates obtained from the root, stem, and leaf segments of H. serrata were grouped into 19 genera based on their morphological traits and sequence analysis of the internal transcribed spacers (ITS1-5.8S-ITS2), indicating endophytic fungi in H. serrata are diverse and abundant. Aspergillus, Podospora, Penicillium, Colletotrichum, and Acremonium were the frequent genera, whereas the remaining genera were infrequent groups. Overall, 39 endophytic fungi isolates showed acetylcholinesterase (AChE) inhibition in vitro. Nine endophytic fungi isolates from seven distinct genera were capable of producing HupA verified by thin-layer chromatography and reverse-phase high-performance liquid chromatography (RP-HPLC). Among the HupA-producing fungi, the yield of HupA produced by the Shiraia sp. Slf14 was 327.8 μg/l in potato dextrose broth, and the fungal HupA was further validated by mass spectrometry (ESI-MS). The present study demonstrated that H. serrata was a fascinating fungal reservoir for producing HupA and other ChEIs.

Morphological, Physiological, and Taxonomic Characterization of Actinobacterial Isolates Living as Endophytes of Cacao Pods and Cacao Seeds

PubMed Central

Tchinda, Romaric Armel Mouafo; Boudjeko, Thaddée; Simao-Beaunoir, Anne-Marie; Lerat, Sylvain; Tsala, Éric; Monga, Ernest; Beaulieu, Carole

2016-01-01

Vascular plants are commonly colonized by endophytic actinobacteria. However, very little is known about the relationship between these microorganisms and cacao fruits. In order to determine the physiological and taxonomic relationships between the members of this community, actinobacteria were isolated from cacao fruits and seeds. Among the 49 isolates recovered, 11 morphologically distinct isolates were selected for further characterization. Sequencing of the 16S rRNA gene allowed the partition of the selected isolates into three phylogenetic clades. Most of the selected endophytic isolates belonged to the Streptomyces violaceusniger clade. Physiological characterization was carried out and a similarity index was used to cluster the isolates. However, clustering based on physiological properties did not match phylogenetic lineages. Isolates were also characterized for traits commonly associated with plant growth-promoting bacteria, including antibiosis and auxin biosynthesis. All isolates exhibited resistance to geldanamycin, whereas only two isolates were shown to produce this antibiotic. Endophytes were inoculated on radish seedlings and most isolates were found to possess plant growth-promoting abilities. These endophytic actinobacteria inhibited the growth of various plant pathogenic fungi and/or bacteria. The present study showed that S. violaceusniger clade members represent a significant part of the actinobacterial community living as endophytes in cacao fruits and seeds. While several members of this clade are known to be geldanamycin producers and efficient biocontrol agents of plant diseases, we herein established the endophytic lifestyle of some of these microorganisms, demonstrating their potential as plant health agents. PMID:26947442

Morphological, Physiological, and Taxonomic Characterization of Actinobacterial Isolates Living as Endophytes of Cacao Pods and Cacao Seeds.

PubMed

Tchinda, Romaric Armel Mouafo; Boudjeko, Thaddée; Simao-Beaunoir, Anne-Marie; Lerat, Sylvain; Tsala, Éric; Monga, Ernest; Beaulieu, Carole

2016-01-01

Vascular plants are commonly colonized by endophytic actinobacteria. However, very little is known about the relationship between these microorganisms and cacao fruits. In order to determine the physiological and taxonomic relationships between the members of this community, actinobacteria were isolated from cacao fruits and seeds. Among the 49 isolates recovered, 11 morphologically distinct isolates were selected for further characterization. Sequencing of the 16S rRNA gene allowed the partition of the selected isolates into three phylogenetic clades. Most of the selected endophytic isolates belonged to the Streptomyces violaceusniger clade. Physiological characterization was carried out and a similarity index was used to cluster the isolates. However, clustering based on physiological properties did not match phylogenetic lineages. Isolates were also characterized for traits commonly associated with plant growth-promoting bacteria, including antibiosis and auxin biosynthesis. All isolates exhibited resistance to geldanamycin, whereas only two isolates were shown to produce this antibiotic. Endophytes were inoculated on radish seedlings and most isolates were found to possess plant growth-promoting abilities. These endophytic actinobacteria inhibited the growth of various plant pathogenic fungi and/or bacteria. The present study showed that S. violaceusniger clade members represent a significant part of the actinobacterial community living as endophytes in cacao fruits and seeds. While several members of this clade are known to be geldanamycin producers and efficient biocontrol agents of plant diseases, we herein established the endophytic lifestyle of some of these microorganisms, demonstrating their potential as plant health agents.

Characterization of Five Fungal Endophytes Producing Cajaninstilbene Acid Isolated from Pigeon Pea [Cajanus cajan (L.) Millsp.

PubMed Central

Zu, Yuan Gang; Fu, Yu Jie; Wang, Wei; Luo, Meng; Efferth, Thomas

2011-01-01

Five fungal endophytes (K4, K5, K6, K9, K14) producing Cajaninstilbene acid (CSA, 3-hydroxy-4-prenyl-5-methoxystilbene-2-carboxylic acid) were isolated from the roots of pigeon pea [Cajanus cajan (L.) Millsp.]. CSA is responsible for the prominent pharmacological activities in pigeon pea. The amount of CSA in culture solution varied among the five fungal endophytes. K4 produced the highest levels of CSA (1037.13 µg/L) among the endophytes tested after incubation for five days. Both morphological characteristics and molecular methods were used for species identification of fungal endophytes. The five endophytic isolates were characterized by analyzing the internal transcribed spacer (ITS) rRNA and β-tubulin genes. The K4, K5, K9 and K14 strains isolated from pigeon pea roots were found to be closely related to the species Fusarium oxysporum. K6 was identified as Neonectria macrodidym. The present study is the first report on the isolation and identification of fungal endophytes producing CSA in pigeon pea. The study also provides a scientific base for large scale production of CSA. PMID:22102911

Antimicrobial activities of endophytic fungi obtained from the arid zone invasive plant Opuntia dillenii and the isolation of equisetin, from endophytic Fusarium sp.

PubMed

Ratnaweera, Pamoda B; de Silva, E Dilip; Williams, David E; Andersen, Raymond J

2015-07-10

Opuntia dillenii is an invasive plant well established in the harsh South-Eastern arid zone of Sri Lanka. Evidence suggests it is likely that the endophytic fungal populations of O. dillenii assist the host in overcoming biotic and abiotic stress by producing biologically active metabolites. With this in mind there is potential to discover novel natural products with useful biological activities from this hitherto poorly investigated source. Consequently, an investigation of the antimicrobial activities of the endophytes of O. dillenii, that occupies a unique ecological niche, may well provide useful leads in the discovery of new pharmaceuticals. Endophytic fungi were isolated from the surface sterilized cladodes and flowers of O. dillenii using several nutrient media and the antimicrobial activities were evaluated against three Gram-positive and two Gram-negative bacteria and Candida albicans. The two most bioactive fungi were identified by colony morphology and DNA sequencing. The secondary metabolite of the endophyte Fusarium sp. exhibiting the best activity was isolated via bioassay guided chromatography. The chemical structure was elucidated from the ESIMS and NMR spectroscopic data obtained for the active metabolite. The minimum inhibitory concentrations (MICs) of the active compound were determined. Eight endophytic fungi were isolated from O. dillenii and all except one showed antibacterial activities against at least one of the test bacteria. All extracts were inactive against C. albicans. The most bioactive fungus was identified as Fusarium sp. and the second most active as Aspergillus niger. The structure of the major antibacterial compound of the Fusarium sp. was shown to be the tetramic acid derivative, equisetin. The MIC's for equisetin were 8 μg mL(-1) against Bacillus subtilis, 16 μg mL(-1) against Staphylococcus aureus and Methicillin Resistant Staphylococcus aureus (MRSA). O. dillenii, harbors several endophytic fungi capable of producing

[Isolation of endophytic fungi from medicinal plant Brucea javanica and their microbial inhibition activity].

PubMed

Liang, Zi-Ning; Zhu, Hua; Lai, Kai-Ping; Chen, Long

2014-04-01

To isolate and identify endophytic fungi from Brucea javanica, and to detect the antimicrobial activity of these strains. Endophytic fungi were isolated by tissue inoculation culture and identified by conventional morphological characteristic method. Seven kinds of pathogenic fungi and three kinds of bacteria were used as targeting microbes to test microbial inhibition activities by agar plate antagonistic action and modified agar gel diffusion methods, respectively. A total of 83 endophytic fungi strains were isolated from the root, stem, leaf and fruit of Brucea javanica. 34 strains were obtained from the stem, 32 strains were obtained from the leaf, 15 strains were isolated from the root and 2 strains came from the fruit. These 73 strains which had been identified attribute to 5 orders, 6 families and 12 genera. For the isolated strains, 14 strains had antifungal activities against at least one pathogenic fungi, 9 strains showed antibacterial activities against one or more bacteria. Especially, the strain YJ-17 which belonged to Phomopsis genus showed the best inhibitory effect on the targeting microbes. The endophytic fungi from Brucea javanica show diversity and microbial inhibition activity, and are worthy for further study on plant disease controlling.

Isolation and identification of local bacteria endophyte and screening of its antimicrobial property against pathogenic bacteria and fungi

NASA Astrophysics Data System (ADS)

Fikri, Ahmad Syairazie Ibrahim; Rahman, Irman Abdul; Nor, Norefrina Shafinaz Md; Hamzah, Ainon

2018-04-01

Endophytes are organisms, often fungi and bacteria that live in living plant cells. These organisms reside in the living tissues of the host plant in a variety of relationships, ranging from symbiotic to slightly pathogenic. The endophytes may produce a plethora of substances that have potential to be used in modern medicine, agriculture and industry. The aims of this study are to isolate, identify and screening antimicrobial activity of bacterial endophytes. The endophytes were isolated using nutrient agar, incubated at 37°C for 48 hours. Identification of the isolates were done based on morphological characteristics, biochemical tests and 16S rDNA molecular analysis. Disk diffusion method was used to screen for antimicrobial activity of metabolites from endophytes against pathogenic bacteria. Screening for antifungal activity of selected endophytes was done using dual culture method againts pathogenic fungi followed by Kirby-Bauer method. Results showed endophytes designated as B2c and B7b have positive antimicrobial activity. The metabolites from isolate B2c showed antimicrobial activity against pathogenic bacteria methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus aureus and Staphylococcus epidermis, while isolate B7b have positive activities againts MRSA, S. aureus and Pseudomonas aeruginosa. Isolates B2c displayed antifungal activity against Fusarium oxysporum, Fusarium solani, Phytophthora palmivora and Colletotrichum gloeosporioides. Identification using biochemical tests and 16S rDNA sequences identified isolate B2c as Pseudomonas resinovorans with 97% homology and isolate B7b as Bacillus subtilis with 98% homology.

Characterization of cellulases of fungal endophytes isolated from Espeletia spp.

PubMed

Cabezas, Luisa; Calderon, Carolina; Medina, Luis Miguel; Bahamon, Isabela; Cardenas, Martha; Bernal, Adriana Jimena; Gonzalez, Andrés; Restrepo, Silvia

2012-12-01

Endophytes are microorganisms that asymptomatically invade plant tissues. They can stimulate plant growth and/or provide defense against pathogen attacks through the production of secondary metabolites. Most endophyte species are still unknown, and because they may have several applications, the study of their metabolic capabilities is essential. We characterized 100 endophytes isolated from Espeletia spp., a genus unique to the paramo ecosystem, an extreme environment in the Andean mountain range. We evaluated the cellulolytic potential of these endophytes on the saccharification of the oil palm empty fruit bunch (OPEFB). The total cellulolytic activity was measured for each endophyte on filter paper (FPA). In addition, the specific carboxymethyl cellulase (CMCase), exoglucanase, and β-glucosidase activities were determined. We found four fungi positive for cellulases. Of these fungi, Penicillium glabrum had the highest cellulolytic activity after partial purification, with maximal CMCase, exoglucanase and β-glucosidase enzyme activities of 44.5, 48.3, and 0.45 U/ml, respectively. Our data showed that the bioprospection of fungi and the characterization of their enzymes may facilitate the process of biofuel production.

Isolation and enzyme bioprospection of endophytic bacteria associated with plants of Brazilian mangrove ecosystem.

PubMed

Castro, Renata A; Quecine, Maria Carolina; Lacava, Paulo T; Batista, Bruna D; Luvizotto, Danice M; Marcon, Joelma; Ferreira, Anderson; Melo, Itamar S; Azevedo, João L

2014-01-01

The mangrove ecosystem is a coastal tropical biome located in the transition zone between land and sea that is characterized by periodic flooding, which confers unique and specific environmental conditions on this biome. In these ecosystems, the vegetation is dominated by a particular group of plant species that provide a unique environment harboring diverse groups of microorganisms, including the endophytic microorganisms that are the focus of this study. Because of their intimate association with plants, endophytic microorganisms could be explored for biotechnologically significant products, such as enzymes, proteins, antibiotics and others. Here, we isolated endophytic microorganisms from two mangrove species, Rhizophora mangle and Avicennia nitida, that are found in streams in two mangrove systems in Bertioga and Cananéia, Brazil. Bacillus was the most frequently isolated genus, comprising 42% of the species isolated from Cananéia and 28% of the species from Bertioga. However, other common endophytic genera such as Pantoea, Curtobacterium and Enterobacter were also found. After identifying the isolates, the bacterial communities were evaluated for enzyme production. Protease activity was observed in 75% of the isolates, while endoglucanase activity occurred in 62% of the isolates. Bacillus showed the highest activity rates for amylase and esterase and endoglucanase. To our knowledge, this is the first reported diversity analysis performed on endophytic bacteria obtained from the branches of mangrove trees and the first overview of the specific enzymes produced by different bacterial genera. This work contributes to our knowledge of the microorganisms and enzymes present in mangrove ecosystems.

Extracellular enzymatic profiles and taxonomic identification of endophytic fungi isolated from four plant species.

PubMed

Alberto, R N; Costa, A T; Polonio, J C; Santos, M S; Rhoden, S A; Azevedo, J L; Pamphile, J A

2016-11-03

Plants of medicinal and economic importance have been studied to investigate the presence of enzyme-producing endophytic fungi. The characterization of isolates with distinct enzyme production potential may identify suitable alternatives for specialized industry. At Universidade Estadual de Maringá Laboratory of Microbial Biotechnology, approximately 500 isolates of endophytic fungi have been studied over the last decade from various host plants, including medicinally and economically important species, such as Luehea divaricata (Martius et Zuccarini), Trichilia elegans A. Juss, Sapindus saponaria L., Piper hispidum Swartz, and Saccharum spp. However, only a fraction of these endophytes have been identified and evaluated for their biotechnological application, having been initially grouped by morphological characteristics, with at least one representative of each morphogroup tested. In the current study, several fungal strains from four plants (L. divaricata, T. elegans, S. saponaria, and Saccharum spp) were identified by ribosomal DNA typing and evaluated semi-quantitatively for their enzymatic properties, including amylase, cellulase, pectinase, and protease activity. Phylogenetic analysis revealed the presence of four genera of endophytic fungi (Diaporthe, Saccharicola, Bipolaris, and Phoma) in the plants examined. According to enzymatic tests, 62% of the isolates exhibited amylase, approximately 93% cellulase, 50% pectinase, and 64% protease activity. Our results verified that the composition and abundance of endophytic fungi differed between the plants tested, and that these endophytes are a potential enzyme production resource of commercial and biotechnological value.

Culturable bacterial endophytes isolated from Mangrove tree (Rhizophora apiculata Blume) enhance seedling growth in Rice.

PubMed

Deivanai, Subramanian; Bindusara, Amitraghata Santhanam; Prabhakaran, Guruswamy; Bhore, Subhash Janardhan

2014-07-01

Endophytic bacteria do have several potential applications in medicine and in other various sectors of biotechnology including agriculture. Bacterial endophytes need to be explored for their potential applications in agricultural biotechnology. One of the potential applications of bacterial endophytes in agricultural is to enhance the growth of the agricultural crops. Hence, this study was undertaken to explore the plant growth promoting potential application of bacterial endophytes. The objective of this study was to examine the effect of endophytic bacteria from mangrove tree (Rhizophora apiculata Blume) for their efficacy in promoting seedling growth in rice. Eight endophytic bacterial isolates (EBIs) isolated from twig and petiole tissues of the mangrove were identified based on their 16S ribosomal ribonucleic acid (rRNA) gene sequence homology. Separately, surface sterilized paddy seeds were treated with cell-free broth and cell suspension of the EBIs. Rice seedlings were analyzed by various bioassays and data was recorded. The gene sequences of the isolates were closely related to two genera namely, Bacillus and Pantoea. Inoculation of EBIs from R. apiculata with rice seeds resulted in accelerated root and shoot growth with significant increase in chlorophyll content. Among the isolates, Pantoea ananatis (1MSE1) and Bacillus amyloliquefaciens (3MPE1) had shown predominance of activity. Endophytic invasion was recognized by the non-host by rapid accumulation of reactive oxygen species (ROS) and was counteracted by the production of hydrogen peroxide (H2O2) and lipid peroxide. The results demonstrated that EBIs from mangrove tree can increase the fitness of the rice seedlings under controlled conditions. These research findings could be useful to enhance the seedling growth and could serve as foundation in further research on enhancing the growth of the rice crop using endophytic bacteria.

Actinomycetes in Karstic caves of northern Spain (Altamira and Tito Bustillo).

PubMed

Groth, I; Vettermann, R; Schuetze, B; Schumann, P; Saiz-Jimenez, C

1999-05-01

A variety of isolation procedures were carried out to study the involvement of bacteria in the colonisation and biodeterioration of Spanish caves with paleolithic rock art (Altamira and Tito Bustillo). The applied techniques mainly aimed to isolate heterotrophic bacteria such as streptomycetes, nocardioform and coryneform actinomycetes, and other gram-positive and gram-negative bacteria. The results demonstrated that actinomycetes were the most abundant gram-positive bacteria in the caves. Actinomycetes revealed a great taxonomic diversity with the predominant isolates belonging to the genus Streptomyces. Members of the genera Nocardia, Rhodococcus, Nocardioides, Amycolatopsis, Saccharothrix, Brevibacterium, Microbacterium, and coccoid actinomycetes (family Micrococcaceae) were also found.

Isolation and characterization of potential antibiotic producing actinomycetes from water and sediments of Lake Tana, Ethiopia

PubMed Central

Gebreyohannes, Gebreselema; Moges, Feleke; Sahile, Samuel; Raja, Nagappan

2013-01-01

Objective To isolate, evaluate and characterize potential antibiotic producing actinomycetes from water and sediments of Lake Tana, Ethiopia. Methods A total of 31 strains of actinomycetes were isolated and tested against Gram positive and Gram negative bacterial strains by primary screening. In the primary screening, 11 promising isolates were identified and subjected to solid state and submerged state fermentation methods to produce crude extracts. The fermented biomass was extracted by organic solvent extraction method and tested against bacterial strains by disc and agar well diffusion methods. The isolates were characterized by using morphological, physiological and biochemical methods. Results The result obtained from agar well diffusion method was better than disc diffusion method. The crude extract showed higher inhibition zone against Gram positive bacteria than Gram negative bacteria. One-way analysis of variance confirmed most of the crude extracts were statistically significant at 95% confidence interval. The minimum inhibitory concentration and minimum bactericidal concentration of crude extracts were 1.65 mg/mL and 3.30 mg/mL against Staphylococcus aureus, and 1.84 mg/mL and 3.80 mg/mL against Escherichia coli respectively. The growth of aerial and substrate mycelium varied in different culture media used. Most of the isolates were able to hydrolysis starch and urea; able to survive at 5% concentration of sodium chloride; optimum temperature for their growth was 30 °C. Conclusions The results of the present study revealed that freshwater actinomycetes of Lake Tana appear to have immense potential as a source of antibacterial compounds. PMID:23730554

Isolation, morphological identification and in vitro antibacterial activity of endophytic bacteria isolated from Azadirachta indica (neem) leaves

PubMed Central

Singh, Ankit Kumar; Sharma, Rajesh Kumar; Sharma, Varsha; Singh, Tanmay; Kumar, Rajesh; Kumari, Dimple

2017-01-01

Aim: The objective of this study was to isolate endophytic bacteria from Azadirachta indica (neem) leaves, their identification and investigate their antibacterial activity against three Gram-positive bacteria, Staphylococcus aureus, Streptococcus pyogenes and Bacillus cereus and Gram-negative bacteria Escherichia coli, Salmonella Typhimurium and Klebsiella pneumoniae. Materials and Methods: Fresh leaves of A. indica (neem) was procured from the Department of Botany, JNKVV, Jabalpur. Five samples were taken, and each sample was divided into five subsamples and separated for further isolation of endophytic bacteria. For sterilization leaves were treated with double distilled water, 0.1% sodium hypochlorite, 0.01% bavistin, 0.05% and 70% ethanol. Sterilized leaves of the plants were embedded in Kings B (KB) petri plates and incubated at 37°C for 24 h. Characterization of the bacteria was done according to its morphology and by Gram-staining. After that, a single colony was transferred into brain heart infusion (BHI) broth and incubated at 37°C for 24 h. The antibacterial effect was studied by the disk diffusion method with known antibiotic ciprofloxacin (Ci) as standard. Results: A total of 25 bacterial isolates from A. indica (neem) were obtained and identified morphologically. Most of the samples on KB media depicted irregular shape, flat elevation, undulated, rough, opaque, and white in color. Most of the samples on blood agar showed irregular, raise elevation, undulated, smooth, opaque and all the isolates were nonhemolytic and nonchromogenic. The growth of endophytic bacteria in BHI broth were all isolates showed turbidity. The microscopic examination revealed that maximum isolates were Gram-positive and rod shaped. Good antibacterial activity was observed against S. aureus, Streptococcus pyogenes, E. coli, Salmonella Typhimurium, and K. pneumoniae. Conclusions: Endophytic bacteria are present in leaves of A. indica (neem) and it possesses antibacterial

Cytotoxic and antimicrobial activities of endophytic fungi isolated from Bacopa monnieri (L.) Pennell (Scrophulariaceae).

PubMed

Katoch, Meenu; Singh, Gurpreet; Sharma, Sadhna; Gupta, Nidhi; Sangwan, Payare Lal; Saxena, Ajit Kumar

2014-02-11

Endophytes, which reside in plant tissues, have the potential to produce novel metabolites with immense benefits for health industry. Cytotoxic and antimicrobial activities of endophytic fungi isolated from Bacopa monnieri (L.) Pennell were investigated. Endophytic fungi were isolated from the Bacopa monnieri. Extracts from liquid cultures were tested for cytotoxicity against a number of cancer cell lines using the MTT assay. Antimicrobial activity was determined using the micro dilution method. 22% of the examined extracts showed potent (IC50 of <20 μg/ml) cytotoxic activity against HCT-116 cell line. 5.5%, 11%, 11% of the extracts were found to be cytotoxic for MCF-7, PC-3, and A-549 cell lines respectively. 33% extracts displayed antimicrobial activity against at least one test organism with MIC value 10-100 μg/ml. The isolate B9_Pink showed the most potent cytotoxic activity for all the cell lines examined and maximum antimicrobial activity against the four pathogens examined which was followed by B19. Results indicated the potential for production of bioactive agents from endophytes of Bacopa monnieri.

Richness of endophytic fungi isolated from Opuntia ficus-indica Mill. (Cactaceae) and preliminary screening for enzyme production.

PubMed

Bezerra, J D P; Santos, M G S; Svedese, V M; Lima, D M M; Fernandes, M J S; Paiva, L M; Souza-Motta, C M

2012-05-01

Opuntia ficus-indica Mill. (forage cactus) is farmed with relative success in the semi-arid region of the Brazilian northeast for commercial purposes, particularly as forage and food. Endophytic microorganisms are those that can be isolated inside plant tissues and can be a new source to production of enzymes with different potentialities. The objective of this study was to describe the richness of endophytic fungi from O. ficus-indica and to detect the capacity of these species to produce extracellular hydrolytic enzymes. Forty-four endophytic fungi species were isolated. Among them, the most commonly found were Cladosporium cladosporioides (20.43%) and C. sphaerospermum (15.99%). Acremonium terricola, Monodictys castaneae, Penicillium glandicola, Phoma tropica and Tetraploa aristata are being reported for the first time as endophytic fungi for Brazil. The majority of isolated fungi exhibited enzymatic potential. Aspergillus japonicus and P. glandicola presented pectinolytic activity. Xylaria sp. was the most important among the other 14 species with positive cellulase activity. All 24 isolates analysed were xylanase-positive. Protease was best produced by isolate PF103. The results indicate that there is a significant richness of endophytic fungi in O. ficus-indica, and that these isolates indicate promising potential for deployment in biotechnological processes involving production of pectinases, cellulases, xylanases and proteases.

Sphaerisporangium dianthi sp. nov., an endophytic actinomycete isolated from a root of Dianthus chinensis L.

PubMed

Xing, Jia; Liu, Chongxi; Zhang, Yuejing; He, Hairong; Zhou, Ying; Li, Lianjie; Zhao, Junwei; Liu, Shuanghe; Wang, Xiangjing; Xiang, Wensheng

2015-01-01

A novel actinomycete, designated strain NEAU-CY18(T), was isolated from the root of a Chinese medicinal plant Dianthus chinensis L and subjected to a polyphasic taxonomic study. The novel strain was found to develop spherical sporangia with non-motile spores on aerial mycelium. The cell-wall peptidoglycan was found to contain meso-diaminopimelic acid. The whole-cell sugars were identified as madurose, mannose, ribose, galactose and glucose. The phospholipid profile was found to contain diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, hydroxy-phosphatidylmethylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannosides and an unidentified phospholipid. The predominant menaquinones were identified as MK-9(H4), MK-9(H2) and MK-9(H6). The major fatty acids were identified as C17:0 10-methyl, iso-C16:0 and C16:0. EzTaxon-e analysis of the 16S rRNA gene sequence indicated that the strain belongs to the genus Sphaerisporangium and was most closely related to Sphaerisporangium cinnabarinum JCM 3291(T) (98.9 %) and Sphaerisporangium melleum JCM 13064(T) (98.3 %). Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain NEAU-CY18(T) forms a monophyletic clade with S. cinnabarinum JCM 3291(T), an association that was supported by a bootstrap value of 97 % in the neighbour-joining tree and also recovered with the maximum-likelihood algorithm. Comparisons of some phenotypic properties and low DNA-DNA relatedness values enabled the strain to be differentiated from S. cinnabarinum JCM 3291(T) and S. melleum JCM 13064(T). Therefore, it is concluded that strain NEAU-CY18(T) represents a novel Sphaerisporangium species, for which the name Sphaerisporangium dianthi sp. nov. is proposed. The type strain is NEAU-CY18(T) ( = CGMCC 4.7132(T) = DSM 46736(T)).

Fungal endophytes of Vanilla planifolia across Réunion Island: isolation, distribution and biotransformation.

PubMed

Khoyratty, Shahnoo; Dupont, Joëlle; Lacoste, Sandrine; Palama, Tony Lionel; Choi, Young Hae; Kim, Hye Kyong; Payet, Bertrand; Grisoni, Michel; Fouillaud, Mireille; Verpoorte, Robert; Kodja, Hippolyte

2015-06-14

The objective of the work was to characterize fungal endophytes from aerial parts of Vanilla planifolia. Also, to establish their biotransformation abilities of flavor-related metabolites. This was done in order to find a potential role of endophytes on vanilla flavors. Twenty three MOTUs were obtained, representing 6 fungal classes. Fungi from green pods were cultured on mature green pod based media for 30 days followed by (1)H NMR and HPLC-DAD analysis. All fungi from pods consumed metabolized vanilla flavor phenolics. Though Fusarium proliferatum was recovered more often (37.6% of the isolates), it is Pestalotiopsis microspora (3.0%) that increased the absolute amounts (quantified by (1)H NMR in μmol/g DW green pods) of vanillin (37.0 × 10(-3)), vanillyl alcohol (100.0 × 10(-3)), vanillic acid (9.2 × 10(-3)) and p-hydroxybenzoic acid (87.9 × 10(-3)) by significant amounts. All plants studied contained endophytic fungi and the isolation of the endophytes was conducted from plant organs at nine sites in Réunion Island including under shade house and undergrowth conditions. Endophytic variation occured between cultivation practices and the type of organ. Given the physical proximity of fungi inside pods, endophytic biotransformation may contribute to the complexity of vanilla flavors.

Combined genetic and bioactivity-based prioritization leads to the isolation of an endophyte-derived antimycobacterial compound.

PubMed

Alvin, A; Kalaitzis, J A; Sasia, B; Neilan, B A

2016-05-01

To initiate a genetic and bioactivity-based screening programme of culturable endophytes to identify micro-organisms capable of producing bioactive polyketides and peptides. Fungal endophytes were isolated from flowers, leaves and roots of Rhoeo spathacea, revealing a community consisting of Colletotrichum sp., Fusarium sp., Guignardia sp., Phomopsis sp., Phoma sp. and Microdochium sp. Genetic screening showed that all isolates had polyketide synthase (PKS) genes and most had nonribosomal peptide synthetase (NRPS) genes. Ethyl acetate extracts of the fungal isolates exhibited antiproliferative activity against at least one of the seven bacterial and mycobacterial test strains. Nuclear Magnetic Resonance -guided fractionation of the crude extract from a Fusarium sp. strain which exhibited strong antiproliferative activity against Mycobacterium tuberculosis resulted in the isolation of the polyketide javanicin. This compound was active against Myco. tuberculosis (MIC = 25 μg ml(-1)) and Mycobacterium phlei (MIC = 50 μg ml(-1)). The medicinal plant R. spathacea hosts a variety of fungal endophytes capable of producing antibacterial and antimycobacterial compounds. There is a positive correlation between the presence of PKS and/or NRPS encoding genes in endophytes and the bioactivity of their respective organic extracts. This is the first report on the fungal endophytic diversity of R. spathacea, and the isolation of an antimycobacterial compound from the plant which has been traditionally used for the treatment of tuberculosis symptoms. © 2016 The Society for Applied Microbiology.

Marine actinomycetes: an ongoing source of novel bioactive metabolites.

PubMed

Subramani, Ramesh; Aalbersberg, William

2012-12-20

Actinomycetes are virtually unlimited sources of novel compounds with many therapeutic applications and hold a prominent position due to their diversity and proven ability to produce novel bioactive compounds. There are more than 22,000 known microbial secondary metabolites, 70% of which are produced by actinomycetes, 20% from fungi, 7% from Bacillus spp. and 1-2% by other bacteria. Among the actinomycetes, streptomycetes group are considered economically important because out of the approximately more than 10,000 known antibiotics, 50-55% are produced by this genus. The ecological role of actinomycetes in the marine ecosystem is largely neglected and various assumptions meant there was little incentive to isolate marine strains for search and discovery of new drugs. The search for and discovery of rare and new actinomycetes is of significant interest to drug discovery due to a growing need for the development of new and potent therapeutic agents. Modern molecular technologies are adding strength to the target-directed search for detection and isolation of bioactive actinomycetes, and continued development of improved cultivation methods and molecular technologies for accessing the marine environment promises to provide access to this significant new source of chemical diversity with novel/rare actinomycetes including new species of previously reported actinomycetes. Copyright © 2012 Elsevier GmbH. All rights reserved.

Cytotoxic and antimicrobial activities of endophytic fungi isolated from Bacopa monnieri (L.) Pennell (Scrophulariaceae)

PubMed Central

2014-01-01

Background Endophytes, which reside in plant tissues, have the potential to produce novel metabolites with immense benefits for health industry. Cytotoxic and antimicrobial activities of endophytic fungi isolated from Bacopa monnieri (L.) Pennell were investigated. Methods Endophytic fungi were isolated from the Bacopa monnieri. Extracts from liquid cultures were tested for cytotoxicity against a number of cancer cell lines using the MTT assay. Antimicrobial activity was determined using the micro dilution method. Results 22% of the examined extracts showed potent (IC50 of <20 μg/ml) cytotoxic activity against HCT-116 cell line. 5.5%, 11%, 11% of the extracts were found to be cytotoxic for MCF-7, PC-3, and A-549 cell lines respectively. 33% extracts displayed antimicrobial activity against at least one test organism with MIC value 10–100 μg/ml. The isolate B9_Pink showed the most potent cytotoxic activity for all the cell lines examined and maximum antimicrobial activity against the four pathogens examined which was followed by B19. Conclusions Results indicated the potential for production of bioactive agents from endophytes of Bacopa monnieri. PMID:24512530

An endophytic fungus isolated from finger millet (Eleusine coracana) produces anti-fungal natural products

PubMed Central

Mousa, Walaa K.; Schwan, Adrian; Davidson, Jeffrey; Strange, Philip; Liu, Huaizhi; Zhou, Ting; Auzanneau, France-Isabelle; Raizada, Manish N.

2015-01-01

Finger millet is an ancient African cereal crop, domesticated 7000 years ago in Ethiopia, reaching India at 3000 BC. Finger millet is reported to be resistant to various fungal pathogens including Fusarium sp. We hypothesized that finger millet may host beneficial endophytes (plant-colonizing microbes) that contribute to the antifungal activity. Here we report the first isolation of endophyte(s) from finger millet. Five distinct fungal species were isolated from roots and predicted taxonomically based on 18S rDNA sequencing. Extracts from three putative endophytes inhibited growth of F. graminearum and three other pathogenic Fusarium species. The most potent anti-Fusarium strain (WF4, predicted to be a Phoma sp.) was confirmed to behave as an endophyte using pathogenicity and confocal microscopy experiments. Bioassay-guided fractionation of the WF4 extract identified four anti-fungal compounds, viridicatol, tenuazonic acid, alternariol, and alternariol monomethyl ether. All the purified compounds caused dramatic breakage of F. graminearum hyphae in vitro. These compounds have not previously been reported to have anti-Fusarium activity. None of the compounds, except for tenuazonic acid, have previously been reported to be produced by Phoma. We conclude that the ancient, disease-tolerant crop, finger millet, is a novel source of endophytic anti-fungal natural products. This paper suggests the value of the crops grown by subsistence farmers as sources of endophytes and their natural products. Application of these natural chemicals to solve real world problems will require further validation. PMID:26539183

An endophytic fungus isolated from finger millet (Eleusine coracana) produces anti-fungal natural products.

PubMed

Mousa, Walaa K; Schwan, Adrian; Davidson, Jeffrey; Strange, Philip; Liu, Huaizhi; Zhou, Ting; Auzanneau, France-Isabelle; Raizada, Manish N

2015-01-01

Finger millet is an ancient African cereal crop, domesticated 7000 years ago in Ethiopia, reaching India at 3000 BC. Finger millet is reported to be resistant to various fungal pathogens including Fusarium sp. We hypothesized that finger millet may host beneficial endophytes (plant-colonizing microbes) that contribute to the antifungal activity. Here we report the first isolation of endophyte(s) from finger millet. Five distinct fungal species were isolated from roots and predicted taxonomically based on 18S rDNA sequencing. Extracts from three putative endophytes inhibited growth of F. graminearum and three other pathogenic Fusarium species. The most potent anti-Fusarium strain (WF4, predicted to be a Phoma sp.) was confirmed to behave as an endophyte using pathogenicity and confocal microscopy experiments. Bioassay-guided fractionation of the WF4 extract identified four anti-fungal compounds, viridicatol, tenuazonic acid, alternariol, and alternariol monomethyl ether. All the purified compounds caused dramatic breakage of F. graminearum hyphae in vitro. These compounds have not previously been reported to have anti-Fusarium activity. None of the compounds, except for tenuazonic acid, have previously been reported to be produced by Phoma. We conclude that the ancient, disease-tolerant crop, finger millet, is a novel source of endophytic anti-fungal natural products. This paper suggests the value of the crops grown by subsistence farmers as sources of endophytes and their natural products. Application of these natural chemicals to solve real world problems will require further validation.

Bioprospecting of Novel and Bioactive Compounds from Marine Actinomycetes Isolated from South China Sea Sediments.

PubMed

Yang, Na; Song, Fuhang

2018-02-01

Marine actinomycetes are less investigated compared to terrestrial strains as potential sources of natural products. To date, few investigations have been performed on culturable actinomycetes associated with South China Sea sediments. In the present study, twenty-eight actinomycetes were recovered from South China Sea sediments after dereplication by traditional culture-dependent method. The 16S rRNA gene sequences analyses revealed that these strains related to five families and seven genera. Twelve representative strains possessed at least one of the biosynthetic genes coding for polyketide synthase I, II, and nonribosomal peptide synthetase. Four strains had anti-Mycobacterium phlei activities and five strains had activities against methicillin-resistant Staphylococcus aureus. 10 L-scale fermentation of strains Salinispora sp. NHF45, Nocardiopsis sp. NHF48, and Streptomyces sp. NHF86 were carried out for novel and bioactive compounds discovery. Finally, we obtained a novel α-pyrone compound from marine Nocardiopsis sp. NHF48, an analogue of paulomenol from marine Streptomyces sp. NHF86 and a new source of rifamycin B, produced by Salinispora sp. NHF45. The present study concluded that marine actinomycetes, which we isolated from South China Sea sediments, will be a suitable source for the development of novel and bioactive compounds.

Indentification of huperzine A-producing endophytic fungi isolated from Huperzia serrata.

PubMed

Dong, Li-Hui; Fan, San-Wei; Ling, Qing-Zhi; Huang, Bei-Bei; Wei, Zhao-Jun

2014-03-01

This present study was designed to investigate the production of huperzine A (HupA), an acetylcholine inhibitor, which was produced by an endophytic fungi isolated from Huperzia serrata. Screening of 94 endophytic fungal isolates obtained from plant H. serrata was carried out for the production of HupA. Their morphological characteristics were studied and rDNA sequence analysis was carried out. The cultures were grown in liquid culture medium and the extracted metabolites were analyzed by thin layer chromatography and high performance liquid chromatograph for the presence of HupA. The DPPH scavenging ratio and inhibition ratio of acetylcholinesterase (AchE) of the same were determined. 3 out of 94 strains i.e. S29, L44 and S94 showed significant AchE-inhibitory activity and antioxidant activity. Strain L44 which exhibited maximum yield of HupA (37.63 μg/g on dry weight basis) was identified as Trichoderma species by ITS sequence analysis. In conclusion, endophytic fungi from H. serrata can be used as a new resource of HupA.

Actinomadura barringtoniae sp. nov., an endophytic actinomycete isolated from the roots of Barringtonia acutangula (L.) Gaertn.

PubMed

Rachniyom, Hathairat; Matsumoto, Atsuko; Inahashi, Yuki; Take, Akira; Takahashi, Yoko; Thamchaipenet, Arinthip

2018-05-01

A novel actinomycete strain, designated GKU 128 T , isolated from the roots of an Indian oak tree [Barringtonia acutangula (L.) Gaertn.] at Khao Khitchakut district, Chantaburi province, Thailand, was characterized by using a polyphasic approach. The strain formed a branched substrate and aerial mycelia which differentiated into straight to flexuous chains of smooth-ornamented spores. Analysis of the cell wall revealed the presence of meso-diaminopimelic acid and N-acetylmuramic acid in the peptidoglycan. The whole-cell sugars were glucose, madurose, mannose, rhamnose and ribose. Mycolic acids were absent. The major phospholipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositolmannoside. The predominant menaquinones were MK-9(H6), MK-9(H8), MK-9(H0) and MK-9(H4). The major fatty acids were C16 : 0, C18 : 1ω9c and 10-methyl C18 : 0 (tuberculostearic acid). The genomic DNA G+C content was 70.5 mol%. Based on 16S rRNA gene sequence analysis, strain GKU 128 T was closely related to the type strains of Actinomadura nitritigenes NBRC 15918 T (99.2 % sequence similarity) and Actinomadura fibrosa JCM 9371 T (98.7 %). The levels of DNA-DNA relatedness between strain GKU 128 T and the closely related type species were less than 19 %. On the basis of phenotypic and genotypic characteristics, strain GKU 128 T could be distinguished from its closely related type strains and represents a novel species of the genus Actinomadura, for which the name Actinomadura barringtoniae sp. nov. (=TBRC 7225 T =NBRC 113074 T ) is proposed.

Lethality of cytochalasin B and other compounds isolated from fungus Aspergillus sp. (Trichocomaceae) endophyte of Bauhinia guianensis (Fabaceae).

PubMed

Feitosa, André de O; Dias, Amanda Cristina S; Ramos, Gisele da C; Bitencourt, Heriberto R; Siqueira, José Edson S; Marinho, Patrícia Santana B; Barison, Andersson; Ocampos, Fernanda M M; Marinho, Andrey Moacir do R

Endophytic fungi are fungi that colonize internal tissues of plants; several biologically active compounds have been isolated from these fungi. There are few studies of compounds isolated from endophytic fungi of Amazon plants. Thus, this study aimed the isolation and structural identification of ergosterol (1), ergosterol peroxide (2), mevalonolactone (3), cytochalasin B (4) and cytochalasin H (5) from Aspergillus sp. EJC 04, an endophytic fungus from Bauhinia guianensis. The cytochalasin B (4) and the diacetate derivative of cytochalasin B (4a) showed high lethality in the brine shrimp assay. This is the first occurrence of cytochalasins in Amazonian endophytic fungi from B. guianensis. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

[Study of marine actinomycetes isolated from the central coast of Peru and their antibacterial activity against methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecalis].

PubMed

León, Jorge; Aponte, Juan José; Rojas, Rosario; Cuadra, D'Lourdes; Ayala, Nathaly; Tomás, Gloria; Guerrero, Marco

2011-06-01

To determine the antimicrobial potential of marine actinomycetes against drug-resistant pathogens represented by strains of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecalis (VRE). Strains of actinomycetes (29) isolated from marine sediment were evaluated by their characteristics in two culture media and by testing their inhibitory capacity by in vitro antagonism against multi-drug resistant (MDR) pathogenic bacteria for MRSA and VRE. Organic extracts of 3 selected actinomicetes were processed to determine the minimum inhibitory concentration (MIC) of the active compound. Most isolated actinomycetes belong to a homogeneous group of write-gray actinomycetes with a good growth in Marine Agar. The inhibitory rates of the isolates were above 85% for both pathogens with inhibition zones greater than 69 and 78 mm in diameter for MRSA and VRE respectively. Dichloromethane extracts of 3 isolates (I-400A, B1-T61, M10-77) showed strong inhibitory activity of both pathogens, M10-77 being the highest actinomycete strain with antibiotic activity against methicillin-resistant S. aureus ATCC 43300 and vancomycin-resistant E. faecalis ATCC 51299 with a minimum inhibitory concentrations (MIC) of 7.9 and 31.7 μg/ml respectively. Phylogenetic analysis of M10-77 strain showed 99% similarity with the marine species Streptomyces erythrogriseus. Marine sediments of the central coast of Peru, are a source of actinomycetes strains showing high capacity to produce bioactive compounds able to inhibit pathogens classified as multi-drug-resistant such as methicillin-resistant S. aureus and vancomycin-resistant E. faecalis.

Indentification of vincamine indole alkaloids producing endophytic fungi isolated from Nerium indicum, Apocynaceae.

PubMed

Na, Ren; Jiajia, Liu; Dongliang, Yang; Yingzi, Peng; Juan, Hong; Xiong, Liu; Nana, Zhao; Jing, Zhou; Yitian, Luo

2016-11-01

Vincamine, a monoterpenoid indole alkaloid which had been marketed as nootropic drugs for the treatment of cerebral insufficiencies, is widely found in plants of the Apocynaceae family. Nerium indicum is a plant belonging to the Apocynaceae family. So, the purpose of this research was designed to investigate the vincamine alkaloids producing endophytic fungi from Nerium indicum, Apocynaceae. 11 strains of endophytic fungi, isolated from the stems and roots of the plant, were grouped into 5 genera on the basis of morphological characteristics. All fungal isolates were fermented and their extracts were preliminary screened by Dragendorff's reagent and thin layer chromatography (TLC). One isolated strain CH1, isolated from the stems of Nerium indicum, had the same Rf value (about 0.56) as authentic vincamine. The extracts of strain CH1 were further analyzed by high performance liquid chromatography (HPLC) and liquid chromatograph-mass spectrometry (LC-MS), and the results showed that the strain CH1 could produce vincamine and vincamine analogues. The acetylcholinesterase (AchE) inhibitory activity assays using Ellman's method revealed that the metabolites of strain CH1 had significant AchE inhibitory activity with an IC50 value of 5.16μg/mL. The isolate CH1 was identified as Geomyces sp. based on morphological and molecular identification, and has been deposited in the China Center for Type Culture Collection (CCTCCM 2014676). This study first reported the natural compounds tabersonine and ethyl-vincamine from endophytic fungi CH1, Geomyces sp. In conclusion, the fungal endophytes from Nerium indicum can be used as alternative source for the production of vincamine and vincamine analogues. Copyright © 2016 Elsevier GmbH. All rights reserved.

Hypocrea lixii, novel endophytic fungi producing anticancer agent cajanol, isolated from pigeon pea (Cajanus cajan [L.] Millsp.).

PubMed

Zhao, J; Li, C; Wang, W; Zhao, C; Luo, M; Mu, F; Fu, Y; Zu, Y; Yao, M

2013-07-01

The aim was to isolate, identify and characterize endophytes from pigeon pea (Cajanus cajan [L.] Millsp.), as novel producer of cajanol and its in vitro cytotoxicity assay. Isolation, identification and characterization of novel endophytes producing cajanol from the roots of pigeon pea were investigated. The endophytes were identified as Hypocrea lixii by morphological and molecular methods. Cajanol produced by endophytes were quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). R-18 produced the highest levels of cajanol (322·4 ± 10·6 μg l(-1) or 102·8 ± 6·9 μg g(-1) dry weight of mycelium) after incubation for 7 days. The cytotoxicity towards human lung carcinoma cells (A549) of fungal cajanol was investigated in vitro. First, a novel endophyte Hypocrea lixii, producing anticancer agent cajanol, was isolated from the host pigeon pea (Cajanus cajan [L.] Millsp.). Fungal cajanol possessed stronger cytotoxicity activity towards A549 cells in time- and dose-dependent manners. This endophyte is a potential handle for scientific and commercial exploitation, and it could provide a promising alterative approach for large-scale production of cajanol to satisfy new anticancer drug development. Journal of Applied Microbiology © 2013 The Society for Applied Microbiology.

Diversity and seasonal variation of endophytic fungi isolated from three conifers in mt. Taehwa, Korea.

PubMed

Kim, Chang-Kyun; Eo, Ju-Kyeong; Eom, Ahn-Heum

2013-06-01

The needled leaves of three conifer species were collected in Mt. Taehwa during different seasons of the year. Total 59 isolates and 19 species of endophytic fungi were isolated from the leaves and identified using morphological and molecular characteristics. As a result, Shannon index was different in its host plant; Larix kaempferi had a highest value of species diversity. According to the sampling season, 9 species of 19 species were isolated during fall season. The results suggest that the existing of host plant and sampling season are major factors of distribution of endophytic fungi.

Characterization of Antifungal Natural Products Isolated from Endophytic Fungi of Finger Millet (Eleusine coracana).

PubMed

Mousa, Walaa Kamel; Schwan, Adrian L; Raizada, Manish N

2016-09-03

Finger millet is an ancient African-Indian crop that is resistant to many pathogens including the fungus, Fusarium graminearum. We previously reported the first isolation of putative fungal endophytes from finger millet and showed that the crude extracts of four strains had anti-Fusarium activity. However, active compounds were isolated from only one strain. The objectives of this study were to confirm the endophytic lifestyle of the three remaining anti-Fusarium isolates, to identify the major underlying antifungal compounds, and to initially characterize the mode(s) of action of each compound. Results of confocal microscopy and a plant disease assay were consistent with the three fungal strains behaving as endophytes. Using bio-assay guided fractionation and spectroscopic structural elucidation, three anti-Fusarium secondary metabolites were purified and characterized. These molecules were not previously reported to derive from fungi nor have antifungal activity. The purified antifungal compounds were: 5-hydroxy 2(3H)-benzofuranone, dehydrocostus lactone (guaianolide sesquiterpene lactone), and harpagoside (an iridoide glycoside). Light microscopy and vitality staining were used to visualize the in vitro interactions between each compound and Fusarium; the results suggested a mixed fungicidal/fungistatic mode of action. We conclude that finger millet possesses fungal endophytes that can synthesize anti-fungal compounds not previously reported as bio-fungicides against F. graminearum.

Lignin-solubilizing ability of actinomycetes isolated from termite (Termitidae) gut.

PubMed Central

Pasti, M B; Pometto, A L; Nuti, M P; Crawford, D L

1990-01-01

The lignocellulose-degrading abilities of 11 novel actinomycete strains isolated from termite gut were determined and compared with that of the well-characterized actinomycete, Streptomyces viridosporus T7A. Lignocellulose bioconversion was followed by (i) monitoring the degradation of [14C]lignin- and [14C]cellulose-labeled phloem of Abies concolor to 14CO2 and 14C-labeled water-soluble products, (ii) determining lignocellulose, lignin, and carbohydrate losses resulting from growth on a lignocellulose substrate prepared from corn stalks (Zea mays), and (iii) quantifying production of a water-soluble lignin degradation intermediate (acid-precipitable polymeric lignin). The actinomycetes were all Streptomyces strains and could be placed into three groups, including a group of five strains that appear superior to S. viridosporus T7A in lignocellulose-degrading ability, three strains of approximately equal ability, and three strains of lesser ability. Strain A2 was clearly the superior and most effective lignocellulose decomposer of those tested. Of the assays used, total lignocellulose weight loss was most useful in determining overall bioconversion ability but not in identifying the best lignin-solubilizing strains. A screening procedure based on 14CO2 evolution from [14C-lignin]lignocellulose combined with measurement of acid-precipitable polymeric lignin yield was the most effective in identifying lignin-solubilizing strains. For the termite gut strains, the pH of the medium showed no increase after 3 weeks of growth on lignocellulose. This is markedly different from the pattern observed with S. viridosporus T7A, which raises the medium pH considerably. Production of extracellular peroxidases by the 11 strains and S. viridosporus T7A was followed for 5 days in liquid cultures.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2167628

Gymnemagenin-producing endophytic fungus isolated from a medicinal plant Gymnema sylvestre R.Br.

PubMed

Parthasarathy, Ramalingam; Sathiyabama, Muthukrishnan

2014-03-01

Gymnema sylvestre is a plant containing the triterpenoid gymnemagenin, which is used in the pharmaceutical industry as an antidiabetic agent. The objective of this study was to determine whether endophytic fungi, isolated from G. sylvestre, produce gymnemagenin. We isolated an endophytic fungal strain from the leaves of G. sylvestre which produces gymnemagenin in the medium. The fungus was identified as Penicillium oxalicum based on morphological and molecular methods. The strain had a component with the same TLC Rf value and HPLC retention time as authentic gymnemagenin. The presence of gymnemagenin was further confirmed by FTIR, UV, and (1)H NMR analyses.

Transformation of 2,4,6-trinitrotoluene (TNT) by actinomycetes isolated from TNT-contaminated and uncontaminated environments

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

Pasti-Grigsby, M.B.; Lewis, T.A.; Crawford, D.L.

1996-03-01

Biotransformation of TNT has been reported under both aerobic and anaerobic conditions. Actinomycetes are important decomposers in composts. This study examines the tolerance of acitomycete cultures, isolated from both TNT-contaminated and uncontaminated environments for different concentrations to TNT, determined how selected isolates transform TNT, and examined whether such TNT transformations were constitutive or induced by exposure to TNT. 33 refs., 1 figs., 1 tab.

Endophytic fungi isolated from oil-seed crop Jatropha curcas produces oil and exhibit antifungal activity.

PubMed

Kumar, Susheel; Kaushik, Nutan

2013-01-01

Jatropha curcas L., a perennial plant grown in tropics and subtropics is popularly known for its potential as biofuel. The plant is reported to survive under varying environmental conditions having tolerance to stress and an ability to manage pest and diseases. The plant was explored for its endophytic fungi for use in crop protection. Endophytic fungi were isolated from leaf of Jatropha curcas, collected from New Delhi, India. Four isolates were identified as Colletotrichum truncatum, and other isolates were identified as Nigrospora oryzae, Fusarium proliferatum, Guignardia cammillae, Alternaria destruens, and Chaetomium sp. Dual plate culture bioassays and bioactivity assays of solvent extracts of fungal mycelia showed that isolates of Colletotrichum truncatum were effective against plant pathogenic fungi Fusarium oxysporum and Sclerotinia sclerotiorum. Isolate EF13 had highest activity against S. sclerotiorum. Extracts of active endophytic fungi were prepared and tested against S. sclerotiorum. Ethyl acetate and methanol extract of C. truncatum EF10 showed 71.7% and 70% growth inhibition, respectively. Hexane extracts of C. truncatum isolates EF9, EF10, and EF13 yielded oil and the oil from EF10 was similar to oil of the host plant, i.e., J. curcas.

Endophytic Fungi Isolated from Oil-Seed Crop Jatropha curcas Produces Oil and Exhibit Antifungal Activity

PubMed Central

Kumar, Susheel; Kaushik, Nutan

2013-01-01

Jatropha curcas L., a perennial plant grown in tropics and subtropics is popularly known for its potential as biofuel. The plant is reported to survive under varying environmental conditions having tolerance to stress and an ability to manage pest and diseases. The plant was explored for its endophytic fungi for use in crop protection. Endophytic fungi were isolated from leaf of Jatropha curcas, collected from New Delhi, India. Four isolates were identified as Colletotrichum truncatum, and other isolates were identified as Nigrospora oryzae, Fusarium proliferatum, Guignardia cammillae, Alternaria destruens, and Chaetomium sp. Dual plate culture bioassays and bioactivity assays of solvent extracts of fungal mycelia showed that isolates of Colletotrichum truncatum were effective against plant pathogenic fungi Fusarium oxysporum and Sclerotinia sclerotiorum. Isolate EF13 had highest activity against S. sclerotiorum. Extracts of active endophytic fungi were prepared and tested against S. sclerotiorum. Ethyl acetate and methanol extract of C. truncatum EF10 showed 71.7% and 70% growth inhibition, respectively. Hexane extracts of C. truncatum isolates EF9, EF10, and EF13 yielded oil and the oil from EF10 was similar to oil of the host plant, i.e., J. curcas. PMID:23409154

Screening of endophytic bacteria isolated from two kinds of antarctic plant antagonistic konjac soft rot disease

NASA Astrophysics Data System (ADS)

Gong, Mingfu; Lin, Tianxing; Huang, Jiao; Zeng, Bo

2018-04-01

Konjac soft rot has a serious impact on the production of konjac, the use of endophytic bacteria to inhibit konjac soft rot bacteria have many advantages. Twenty-three endophytic bacteria isolated from the medicinal plants were used to determine the antagonistic effects of endophytic bacteria on konjac soft rot in the Oxford cups. Of the strain. The results showed that 23 strains of endophytic bacteria had different antagonistic activities against konjac soft rot, 8 strains had very significant antibacterial effect, and YC06 and YC09 had strong antibacterial ability of two endophytic bacteria. Konjac soft rot fungi also have a strong antibacterial capacity.

Actinomycetes inhibit filamentous fungi from the cuticle of Acromyrmex leafcutter ants.

PubMed

Dângelo, Rômulo Augusto Cotta; de Souza, Danival José; Mendes, Thais Demarchi; Couceiro, Joel da Cruz; Lucia, Terezinha Maria Castro Della

2016-03-01

Actinomycetes bacteria associated with leafcutter ants produce secondary metabolites with antimicrobial properties against Escovopsis, a fungus specialized in attacking the gardens of fungus-growing ants, which denies the ants their food source. Because previous studies have used fungi isolated from fungus gardens but not from ant integument, the aims of the present study were to isolate actinomycetes associated with the cuticle of the Acromyrmex spp. and to quantify their inhibition abilities against the filamentous fungal species carried by these ants. The results demonstrated that actinomycetes had varied strain-dependent effects on several filamentous fungal species in addition to antagonistic activity against Escovopsis. The strain isolated from Acromyrmex balzani was identified as a Streptomyces species, whereas the remaining isolates were identified as different strains belonging to the genus Pseudonocardia. These findings corroborate the hypothesis that actinomycetes do not act specifically against Escovopsis mycoparasites and may have the ability to inhibit other species of pathogenic fungi. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Indoleacetic acid production and plant growth promoting potential of bacterial endophytes isolated from rice (Oryza sativa L.) seeds.

PubMed

Shahzad, Raheem; Waqas, Muhammad; Khan, Abdul Latif; Al-Hosni, Khadija; Kang, Sang-Mo; Seo, Chang-Woo; Lee, In-Jung

2017-06-01

Bacterial endophytes from the phyllosphere and rhizosphere have been used to produce bioactive metabolites and to promote plant growth. However, little is known about the endophytes residing in seeds. This study aimed to isolate and identify seed-borne bacterial endophytes from rice and elucidate their potential for phytohormone production and growth enhancement. The isolated endophytes included Micrococcus yunnanensis RWL-2, Micrococcus luteus RWL-3, Enterobacter soli RWL-4, Leclercia adecarboxylata RWL-5, Pantoea dispersa RWL-6, and Staphylococcus epidermidis RWL-7, which were identified using 16S rRNA sequencing and phylogenetic analysis. These strains were analyzed for indoleacetic acid (IAA) production by using GC-MS and IAA was found in the range of 11.50 ± 0.77 μg ml -1 to 38.80 ± 1.35 μg ml -1 . We also assessed the strains for plant growth promoting potential because these isolates were able to produce IAA in pure culture. Most of the growth attributes of rice plants (shoot and root length, fresh and dry biomass, and chlorophyll content) were significantly increased by bacterial endophytes compared to the controls. These results show that IAA producing bacterial endophytes can improve hostplant growth traits and can be used as bio-fertilizers.

Moderately haloalkaliphilic actinomycetes in salt-affected soils

NASA Astrophysics Data System (ADS)

Zvyagintsev, D. G.; Zenova, G. M.; Oborotov, G. V.

2009-12-01

It was found that the population density of actinomycetes in solonchaks and saline desert soils varied from hundreds to tens of thousands of colony-forming units (CFUs) per 1 g of soil depending on soil type and was by 1-3 orders of magnitude lower than the number of mycelial bacteria in main soil types. Actinomycetes grow actively in saline soils, and the length of their mycelium reaches 140 m per 1 g of soil. Domination of moderately halophilic, alkaliphilic, and haloalkaliphilic actinomycetes, which grow well under 5% NaCl and pH 8-9, is a specific feature of actinomycetal complexes in saline soils. Representatives of Streptomyces and Micromonospora genera were found among the haloalkaliphilic actinomycetes. Micromonospores demonstrated lower (than streptomycetes) adaptability to high salt concentrations. Investigation of the phylogenetic position of isolated dominant haloalkaliphilic strains of streptomycetes performed on the basis of sequencing of the gene 16S rRNA enabled identifying these strains as Streptomyces pluricolorescens and S. prunicolor.

Phylogenetic and chemical diversity of fungal endophytes isolated from Silybum marianum (L) Gaertn. (milk thistle)

PubMed Central

Raja, Huzefa A.; Kaur, Amninder; El-Elimat, Tamam; Figueroa, Mario; Kumar, Rahul; Deep, Gagan; Agarwal, Rajesh; Faeth, Stanley H.; Cech, Nadja B.; Oberlies, Nicholas H.

2015-01-01

Use of the herb milk thistle (Silybum marianum) is widespread, and its chemistry has been studied for over 50 years. However, milk thistle endophytes have not been studied previously for their fungal and chemical diversity. We examined the fungal endophytes inhabiting this medicinal herb to determine: (1) species composition and phylogenetic diversity of fungal endophytes; (2) chemical diversity of secondary metabolites produced by these organisms; and (3) cytotoxicity of the pure compounds against the human prostate carcinoma (PC-3) cell line. Forty-one fungal isolates were identified from milk thistle comprising 25 operational taxonomic units based on BLAST search via GenBank using published authentic sequences from nuclear ribosomal internal transcribed spacer sequence data. Maximum likelihood analyses of partial 28S rRNA gene showed that these endophytes had phylogenetic affinities to four major classes of Ascomycota, the Dothideomycetes, Sordariomycetes, Eurotiomycetes, and Leotiomycetes. Chemical studies of solid–substrate fermentation cultures led to the isolation of four new natural products. In addition, 58 known secondary metabolites, representing diverse biosynthetic classes, were isolated and characterized using a suite of nuclear magnetic resonance and mass spectrometry techniques. Selected pure compounds were tested against the PC-3 cell line, where six compounds displayed cytotoxicity. PMID:26000195

Phylogenetic and chemical diversity of fungal endophytes isolated from Silybum marianum (L) Gaertn. (milk thistle).

PubMed

Raja, Huzefa A; Kaur, Amninder; El-Elimat, Tamam; Figueroa, Mario; Kumar, Rahul; Deep, Gagan; Agarwal, Rajesh; Faeth, Stanley H; Cech, Nadja B; Oberlies, Nicholas H

2015-01-02

Use of the herb milk thistle ( Silybum marianum ) is widespread, and its chemistry has been studied for over 50 years. However, milk thistle endophytes have not been studied previously for their fungal and chemical diversity. We examined the fungal endophytes inhabiting this medicinal herb to determine: (1) species composition and phylogenetic diversity of fungal endophytes; (2) chemical diversity of secondary metabolites produced by these organisms; and (3) cytotoxicity of the pure compounds against the human prostate carcinoma (PC-3) cell line. Forty-one fungal isolates were identified from milk thistle comprising 25 operational taxonomic units based on BLAST search via GenBank using published authentic sequences from nuclear ribosomal internal transcribed spacer sequence data. Maximum likelihood analyses of partial 28S rRNA gene showed that these endophytes had phylogenetic affinities to four major classes of Ascomycota, the Dothideomycetes, Sordariomycetes, Eurotiomycetes, and Leotiomycetes. Chemical studies of solid-substrate fermentation cultures led to the isolation of four new natural products. In addition, 58 known secondary metabolites, representing diverse biosynthetic classes, were isolated and characterized using a suite of nuclear magnetic resonance and mass spectrometry techniques. Selected pure compounds were tested against the PC-3 cell line, where six compounds displayed cytotoxicity.

Actinomycetal complex of light sierozem on the Kopet-Dag piedmont plain

NASA Astrophysics Data System (ADS)

Zenova, G. M.; Zvyagintsev, D. G.; Manucharova, N. A.; Stepanova, O. A.; Chernov, I. Yu.

2016-10-01

The population density of actinomycetes in the samples of light sierozem from the Kopet Dag piedmont plain (75 km from Ashkhabad, Turkmenistan) reaches hundreds of thousand CFU/g soil. The actinomycetal complex is represented by two genera: Streptomyces and Micromonospora. Representatives of the Streptomyces genus predominate and comprise 73 to 87% of the actinomycetal complex. In one sample, representatives of the Micromonospora genus predominated in the complex (75%). The Streptomyces genus in the studied soil samples is represented by the species from several sections and series: the species of section Helvolo-Flavus series Helvolus represent the dominant component of the streptomycetal complex; their portion is up to 77% of all isolated actinomycetes. The species of other sections and series are much less abundant. Thus, the percentage of the Cinereus Achromogenes section in the actinomycetal complex does not exceed 28%; representatives of the Albus section Albus series, Roseus section Lavendulae-Roseus series, and Imperfectus section belong to rare species; they have been isolated not from all the studied samples of light sierozem, and their portion does not exceed 10% of the actinomycetal complex.

Diversity and bioprospecting of culturable actinomycetes from marine sediment of the Yellow Sea, China.

PubMed

Xiong, Zhi-Qiang; Liu, Qiao-Xia; Pan, Zhao-Long; Zhao, Na; Feng, Zhi-Xiang; Wang, Yong

2015-03-01

Marine actinomycetes are a potential source of a wide variety of bioactive natural products. In this work, seven pretreatments, three selective isolation media, and five artificial seawater concentrations were used to isolate actinomycetes from the sediments collected from Yellow Sea, China. Statistical analysis showed that only the isolation medium strongly affected the total and bioactive numbers of actinomycete isolates. A total of 613 actinobacterial strains were isolated and screened for antimicrobial activities; 154 isolates showed activity against at least one of nine test drug-resistant microorganisms. Eighty-nine representatives with strong antimicrobial activity were identified phylogenetically based on 16S rRNA gene sequencing, which were assigned to five different actinomycete genera Streptomyces, Kocuria, Saccharomonospora, Micromonospora, and Nocardiopsis. Using PCR-based screening for six biosynthetic genes of secondary metabolites, all 45 isolates with acute activity have at least one biosynthetic gene, 28.8 % of which possess more than three biosynthetic genes. As a case, strain SMA-1 was selected for antimicrobial natural product discovery. Three diketopiperazine dimers including a new compound iso-naseseazine B (1) and two known compounds naseseazine B (2) and aspergilazine A (3) were isolated by bioassay-guided separation. These results suggested that actinomycetes from marine sediments are a potential resource of novel secondary metabolites and drugs.

A novel endophytic Huperzine A-producing fungus, Shiraia sp. Slf14, isolated from Huperzia serrata.

PubMed

Zhu, D; Wang, J; Zeng, Q; Zhang, Z; Yan, R

2010-10-01

To characterize and identify a novel Huperzine A (HupA)-producing fungal strain Slf14 isolated from Huperzia serrata (Thunb. ex Murray) Trev. in China. The isolation, identification and characterization of a novel endophytic fungus producing HupA specifically and consistently from the leaves of H. serrata were investigated. The fungus was identified as Shiraia sp. Slf14 by molecular and morphological methods. The HupA produced by this endophytic fungus was shown to be identical to authentic HupA analysed by thin layer chromatographic, High-performance liquid chromatography (HPLC), LC-MS, (1) H NMR and acetylcholinesterase (AChE) inhibition activity in vitro. The amount of HupA produced by Shiraia sp. Slf14 was quantified to be 327.8 μg l(-1) by HPLC, which was far higher than that of the reported endophytic fungi, Acremonium sp., Blastomyces sp. and Botrytis sp. The production of HupA by endophyte Shiraia sp. Slf14 is an enigmatic observation. It would be interesting to further study the HupA production and regulation by the cultured endophyte in H. serrata and in axenic cultures. Although the current accumulation of HupA by the endophyte is not very high, it could provide a promising alterative approach for large-scale production of HupA. However, further strain improvement and the fermentation process optimization are required to result in the consistent and dependable production. © 2010 The Authors. Journal compilation © 2010 The Society for Applied Microbiology.

Petroleum degradation by endophytic Streptomyces spp. isolated from plants grown in contaminated soil of southern Algeria.

PubMed

Baoune, Hafida; Ould El Hadj-Khelil, Aminata; Pucci, Graciela; Sineli, Pedro; Loucif, Lotfi; Polti, Marta Alejandra

2018-01-01

Petroleum hydrocarbons are well known by their high toxicity and recalcitrant properties. Their increasing utilization around worldwide led to environmental contamination. Phytoremediation using plant-associated microbe is an interesting approach for petroleum degradation and actinobacteria have a great potential for that. For this purpose, our study aimed to isolate, characterize, and assess the ability of endophytic actinobacteria to degrade crude petroleum, as well as to produce plant growth promoting traits. Seventeen endophytic actinobacteria were isolated from roots of plants grown naturally in sandy contaminated soil. Among them, six isolates were selected on the basis of their tolerance to petroleum on solid minimal medium and characterized by 16S rDNA gene sequencing. All petroleum-tolerant isolates belonged to the Streptomyces genus. Determination by crude oil degradation by gas chromatorgraph-flame ionization detector revealed that five strains could use petroleum as sole carbon and energy source and the petroleum removal achieved up to 98% after 7 days of incubation. These isolates displayed an important role in the degradation of the n-alkanes (C 6 -C 30 ), aromatic and polycyclic aromatic hydrocarbons. All strains showed a wide range of plant growth promoting features such as siderophores, phosphate solubilization, 1-aminocyclopropane-1-carboxylate deaminase, nitrogen fixation and indole-3-acetic acid production as well as biosurfactant production. This is the first study highlighting the petroleum degradation ability and plant growth promoting attributes of endophytic Streptomyces. The finding suggests that the endophytic actinobacteria isolated are promising candidates for improving phytoremediation efficiency of petroleum contaminated soil. Copyright © 2017 Elsevier Inc. All rights reserved.

Isolation, Characterization, and Insecticidal Activity of an Endophyte of Drunken Horse Grass, Achnatherum inebrians

PubMed Central

Shi, YingWu; Zhang, Xuebing; Lou, Kai

2013-01-01

Endophytic microorganisms reside within plant tissues and have often been found to promote plant growth. In this study, endophytic microorganisms were isolated from the roots, stems, leaves, and seeds of healthy drunken horse grass, Achnatherum inebrians (Hance) Keng (Poales: Poaceae), through the use of a grinding separation method and identified by a dual approach of morphological and physiological observation and 16S rRNA gene-based (for bacteria) and internal transcribed sequence-based (for fungi) molecular identification. The endophytes were then inoculated into liquid media for fermentation, and their crude extracts were employed for insecticidal activity tests using slide disc immersion and nebulization methods. A total of 89 bacteria species, which were classified into eight genera, Bacillus, Pseudomonas, Actinomyces, Corynebacterium, Acinetobacter, Sphingomonas, Paenibacillus, and Phyllobacterium, and two fungi, Claviceps and Chaetomium, were isolated. Of these species, isolates Streptomyces albus (Rossi-Doria) Waksman and Henrici (Actinomycetales: Streptomycetaceae) (GA) and Claviceps purpurea (Fr.) Tul. (Hypocreales: Clavicipitaceae) (PF-2) were shown to produce mortality rates of more than 90% in the cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae), after first and second screenings. The isolates PF-2 and GA associated with A. inebrians had significant insecticidal activities towards A. gossypii Glover (Hemiptera: Aphididae) and may provide a new biological resource for exploring a new microbial insecticide. PMID:24784492

Soil actinomycetes in the National Forest Park in northeastern China

NASA Astrophysics Data System (ADS)

Shirokikh, I. G.; Shirokikh, A. A.

2017-01-01

The taxonomic and functional structure of actinomycete complexes in the litters and upper horizons of the soils under an artificial coniferous-broad-leaved forest located around the town of Chanchun (Tszilin province, PRC). The complex of actinomycetes included representatives of the Streptomyces, Micromonospora, Streptosporangium, and Streptoverticillium genera and oligosporous forms. In the actinomycete complexes, streptomycetes prevailed in the abundance (61-95%) and frequency of occurrence (100%). In the parcels of Korean pine ( Pinus koraiensis) and Mongolian oak ( Quercus mongolica), streptomycetes of 19 species from 8 series and 4 sections were isolated. The most representative, as in European forest biomes, was the Cinereus Achromogenes series. A distinguishing feature of the streptomycete complex in the biomes studied was the high participation of species from the Imperfectus series. The verification of the functional activity of natural isolates made it possible to reveal strains with high antagonistic and cellulolytic abilities. A high similarity of actinomycete complexes was found in Eurasian forest ecosystems remote from each other, probably due to the similarity of plant polymers decomposable by actinomycetes.

Comparative analysis of prodigiosin isolated from endophyte Serratia marcescens.

PubMed

Khanam, B; Chandra, R

2018-03-01

Extraction of pigments from endophytes is an uphill task. Up till now, there are no efficient methods available to extract the maximum amount of prodigiosin from Serratia marcescens. This is one of the important endophytes of Beta vulgaris L. The present work was carried out for the comparative study of six different extraction methods such as homogenization, ultrasonication, freezing and thawing, heat treatment, organic solvents and inorganic acids to evaluate the efficiency of prodigiosin yield. Our results demonstrated that highest extraction was observed in ultrasonication (98·1 ± 1·7%) while the lowest extraction by freezing and thawing (31·8 ± 3·8%) methods. However, thin layer chromatography, high-performance liquid chromatography and Fourier transform infrared data suggest that bioactive pigment in the extract was prodigiosin. To the best of our knowledge, this is the first comprehensive study of extraction methods and identification and purification of prodigiosin from cell biomass of Ser. marcescens isolated from Beta vulgaris L. The prodigiosin family is a potent drug with anticancer, antimalarial, antibacterial, antifungal, antiproliferative and immunosuppressive activities. Moreover, it has immense potential in pharmaceutical, food and textile industries. For the industrial perspective, it is essential to achieve purified, high yield and cost-effective extraction of prodigiosin. To the best of our knowledge, this is the first comprehensive study on prodigiosin extraction and also the first report on endophyte Serratia marcescens isolated from Beta vulgaris L. The significance of our results is to extract high amount and good quality prodigiosin for commercial application. © 2017 The Society for Applied Microbiology.

Optimization of isolation and cultivation of bacterial endophytes through addition of plant extract to nutrient media

PubMed Central

Eevers, N; Gielen, M; Sánchez-López, A; Jaspers, S; White, J C; Vangronsveld, J; Weyens, N

2015-01-01

Many endophytes have beneficial effects on plants and can be exploited in biotechnological applications. Studies hypothesize that only 0.001–1% of all plant-associated bacteria are cultivable. Moreover, even after successful isolations, many endophytic bacteria often show reduced regrowth capacity. This research aimed to optimize isolation processes and culturing these bacteria afterwards. We compared several minimal and complex media in a screening. Beside the media themselves, two gelling agents and adding plant extract to media were investigated to enhance the number and diversity of endophytes as well as the growth capacity when regrown after isolation. In this work, 869 medium delivered the highest numbers of cultivable bacteria, as well as the highest diversity. When comparing gelling agents, no differences were observed in the numbers of bacteria. Adding plant extract to the media lead to a slight increase in diversity. However, when adding plant extract to improve the regrowth capacity, sharp increases of viable bacteria occurred in both rich and minimal media. PMID:25997013

Grass fungal endophytes and uses thereof

DOEpatents

Craven, Kelly

2015-03-10

The invention provides isolated fungal endophytes and synthetic combinations thereof with host grass plants. Methods for inoculating grass plant with the endophytes, for propagating the grass-endophyte combinations, and for producing feeds and biofuels from grass-endophyte combinations are also provided.

Piperine production by endophytic fungus Colletotrichum gloeosporioides isolated from Piper nigrum.

PubMed

Chithra, S; Jasim, B; Sachidanandan, P; Jyothis, M; Radhakrishnan, E K

2014-03-15

Many endophytic fungi have been reported with the biosynthetic potential to produce same or similar metabolites present in host plants. The adaptations that might have acquired by these fungi as a result of the long-term association with their host plants can be the possible basis of their biosynthetic potential. The bioactive compounds originated from endophytes are currently explored for their potential applications in pharmaceutical, agriculture and food industries. Piper nigrum, a plant of the Piperaceae is very remarkable because of the presence of the alkaloid piperine. Piperine has been reported to have broad bioactive properties ranging from antimicrobial, antidepressant, anti-inflammatory, antioxidative to anticancer activities. Interestingly, piperine also plays a vital role in increasing the bioavailability of many drugs which again is a promising property. The current study was carried out to identify piperine producing endophytic fungus from Piper nigrum L. By screening various endophytic fungi, the isolate which was identified as member of Colletotrichum gloeosporioides was found to have the ability to form piperine and was confirmed by HPLC and LCMS. Considering the broad bioactive potential of piperine, the piperine producing fungi identified in the study can expect to have much industrial potential. Copyright © 2013 Elsevier GmbH. All rights reserved.

Natural Products from Mangrove Actinomycetes

PubMed Central

Xu, Dong-Bo; Ye, Wan-Wan; Han, Ying; Deng, Zi-Xin; Hong, Kui

2014-01-01

Mangroves are woody plants located in tropical and subtropical intertidal coastal regions. The mangrove ecosystem is becoming a hot spot for natural product discovery and bioactivity survey. Diverse mangrove actinomycetes as promising and productive sources are worth being explored and uncovered. At the time of writing, we report 73 novel compounds and 49 known compounds isolated from mangrove actinomycetes including alkaloids, benzene derivatives, cyclopentenone derivatives, dilactones, macrolides, 2-pyranones and sesquiterpenes. Attractive structures such as salinosporamides, xiamycins and novel indolocarbazoles are highlighted. Many exciting compounds have been proven as potential new antibiotics, antitumor and antiviral agents, anti-fibrotic agents and antioxidants. Furthermore, some of their biosynthetic pathways have also been revealed. This review is an attempt to consolidate and summarize the past and the latest studies on mangrove actinomycetes natural product discovery and to draw attention to their immense potential as novel and bioactive compounds for marine drugs discovery. PMID:24798926

α-Amylase inhibitor activity of endophytic bacteria isolated from Annona muricata L

NASA Astrophysics Data System (ADS)

Pujiyanto, Sri; Resdiani, Merysa; Raharja, Budi; Siti Ferniah, Rejeki

2018-05-01

α-amylase (α-1,4-glucan-4-glucohydrolase, EC 3.2.1.1) is an enzyme that catalyzes the degradation of starch into its monomers. Most people use medicinal plants for keeping normal level of blood glucose, for example, the Annona muricata. The objectives of this study are to obtain endophytic bacteria from the plant, knowing the activity of the α-amylase inhibitor of selected isolates. Endophytic bacteria are isolated from the roots, stems, and leaves of the plant have been sterilized surface and grown in NA medium. A total of 11 isolates were found to produce α-amylase inhibitor compounds. The isolates obtained were tested for their α-amylase inhibitor activity, and isolates with the highest activity tested further. Isolate DS21 show the best activity with 72,22% inhibition. The experimental design used in this research is Completely Randomized Design (RAL). The best isolates treated by a variety of carbon sources, and the best carbon source treated with various pH. The data obtained were analyzed usingAnalysis of Variance (ANOVA). The results of statistical tests show the treatment of starch and lactose has a significant effect on the production of α-amylase inhibitors (P <0.05) and the pH 5 and 6,0 significantly affected the production of α-amylase inhibitors (P <0.05).

Bioprospecting marine actinomycetes for multidrug-resistant pathogen control from Rameswaram coastal area, Tamil Nadu, India.

PubMed

Wahaab, Femina; Subramaniam, Kalidass

2018-01-01

A potent Streptomyces bacillaris strain RAM25C4 was isolated for controlling methicillin-resistant Staphylococcus aureus and multidrug-resistant bacteria such as Staphylococcus aureus, Acinetobacter baumannii, and Pseudomonas aeruginosa. A total of 131 actinomycetes were isolated from the Rameswaram coastal region, Tamil Nadu, India. Among 131 actinomycetes, maximum number of actinomycetes (55%) isolated at the distance of 3-6 m from seashore. Out of 131 actinomycetes, 85% of the actinomycetes exhibited different degree of antagonistic activity against test pathogens. The antagonistic activity evaluated using actinomycetes direct culture filtrate and culture filtrate extracts. Among these culture filtrate, extracts had supreme antagonistic activity against multidrug-resistant bacteria and the solvent ethyl acetate was the best for extracting secondary metabolites from actinomycetes. In HPTLC analysis, the presence of macrolides, terpenoids, and quinolones was identified in RAM25C4 extract. In GC-MS analysis, various potent compounds such as phenolic compound-2,6-di-tert-butylphenol, alkaloid compound-1H, 5H, pyrrolo (1' 2':3, 4) imidazo, and quinolone compound-1,4-benzenediol, 2,5-bis(1,1-dimethylethyl) were identified in the ethyl acetate extract of RAM25C4. The phylogenetic analysis of 16S rRNA gene sequence of RAM25C4 isolate was deposited in NCBI with name Streptomyces bacillaris strain RAM25C4 and accession number KM513543.

[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.

Evaluation of endophytic colonization of Citrus sinensis and Catharanthus roseus seedlings by endophytic bacteria.

PubMed

Lacava, Paulo Teixeira; Araújo, Welington Luiz; Azevedo, João Lúcio

2007-02-01

Over the last few years, the endophytic bacterial community associated with citrus has been studied as an important component interacting with Xylella fastidiosa, the causal agent of citrus variegated chlorosis (CVC). This bacterium may also colonize some model plants, such as Catharanthus roseus and Nicotiana clevelandii. In the present study, we compared the endophytic colonization of Citrus sinensis and Catharanthus roseus using the endophytic bacteria Klebsiella pneumoniae. We chose an appropriate strain, K. pneumoniae 342 (Kp342), labeled with the GFP gene. This strain was inoculated onto seedlings of C. sinensis and C. roseus. The isolation frequency was determined one week after the inoculation and the endophytic colonization of K. pneumoniae was observed using fluorescence microscopy. Although the endophytic bacterium was more frequently isolated from C. roseus than from C. sinensis, the colonization profiles for both host plants were similar, suggesting that C. roseus could be used as a model plant to study the interaction between endophytic bacteria and X. fastidiosa.

Detoxification of Atrazine by Endophytic Streptomyces sp. Isolated from Sugarcane and Detection of Nontoxic Metabolite.

PubMed

Mesquini, Josiane A; Sawaya, Alexandra C H F; López, Begonã G C; Oliveira, Valéria M; Miyasaka, Natalia R S

2015-12-01

Atrazine is still one of the most used agricultural pesticides worldwide and it has been recognized as a major contaminant of surface and ground water. The aims of this research were to isolate an endophytic microorganism from leaves of sugarcane, evaluate its ability to degrade atrazine, and investigate the formation of metabolites. By sequencing of the 16S rRNA gene, the endophytic isolate atz2 was identified as Streptomyces sp. The reduction in atrazine concentration by Streptomyces sp. atz2 was 98 % and UHPLC-MS/MS analyses showed the appearance of an unknown metabolite observed as m/z 311. Ecotoxicity tests with an aquatic organism, Daphnia similis, confirmed that this metabolite was nontoxic. This mechanism of detoxification of atrazine is different from the ones of other free-living microorganisms that inhabit the soil or rhizosphere. The results show new aspects of atrazine detoxification, highlighting a new role of endophytic bacteria in plants.

Production and characterization of a thermostable alpha-amylase from Nocardiopsis sp. endophyte of yam bean.

PubMed

Stamford, T L; Stamford, N P; Coelho, L C; Araújo, J M

2001-01-01

Thermostable amylolytic enzymes have been currently investigated to improve industrial processes of starch degradation. Studies on production of alpha-amylase by Nocardiopsis sp., an endophytic actinomycete isolated from yam bean (Pachyrhizus erosus L. Urban), showed that higher enzyme levels were obtained at the end of the logarithmic growth phase after incubation for 72 h at pH 8.6. Maximum activity of alpha-amylase was obtained at pH 5.0 and 70 degrees C. The isolated enzyme exhibited thermostable properties as indicated by retention of 100% of residual activity at 70 degrees C, and 50% of residual activity at 90 degrees C for 10 min. Extracellular enzyme from Nocardiopsis sp. was purified by fractional precipitation with ammonium sulphate. After 60% saturation produced 1130 U mg-1 protein and yield was 28% with purification 2.7-fold. The enzyme produced by Nocardiopsis sp. has potential for industrial applications.

Fungal endophytes isolated from Protium heptaphyllum and Trattinnickia rhoifolia as antagonists of Fusarium oxysporum.

PubMed

Fierro-Cruz, Juan E; Jiménez, Pedro; Coy-Barrera, Ericsson

Control of fungal pathogens is mainly addressed by the use of chemically synthesized fungicides which result in environmental pollution, developing resistance after prolonged use. In this context, endophytes have been recognized as potential biocontrollers, and also as a promising source of antifungal metabolites. Therefore, as part of our research on phytopathogen controllers, 355 fungal endophytes were isolated from Protium heptaphyllum and Trattinnickia rhoifolia (Burseraceae), both ethnobotanically important tree species that produce secondary metabolites of agronomic and industrial interest. Endophytes were tested by in vitro dual culture against Fusarium oxysporum, a phytopathogen of agronomic importance. Five endophytes exerted at least 40% inhibition on F. oxysporum growth. Ethyl acetate (EtOAc) extracts were obtained from the most active antagonistic fungi, after growing them in three different liquid media. The extracts were tested against a conidial suspension of F. oxysporum by direct bioautography. Two extracts derived from fungi identified as Chaetomium globosum, F211_UMNG and Meyerozima sp. F281_UMNG showed inhibition of pathogen growth. Isolate C. globosum, F211_UMNG was selected for a chemical analysis by RP-HPLC-DAD-ESI-MS and antifungal molecules such as cladosporin, chaetoatrosin A and chaetoviridin A were annotated and identified based on their MS data. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Endophytic fungi isolated from wheat (Triticum durum Desf.): evaluation of their antimicrobial activity, antioxidant activity and host growth promotion.

PubMed

Harzallah, Daoud; Sadrati, Nouari; Zerroug, Amina; Dahamna, Saliha; Bouharati, Saddek

2012-01-01

The emergence of antibiotic-resistant micro-organisms calls for inventive research and development strategies. The screening for antimicrobial compounds from endophytes is a promising way to meet the increasing threat of drug-resistant strains of human and plant pathogens. Endophytes may be defined as "microbes that colonize living, internal tissues of plants without causing any immediate, overt negative effects". Endophytes are relatively unstudied as potential sources of novel natural products for exploitation in medicine, agriculture, and industry. The purpose of this study was to evaluate several isolated fungi from wheat (Triticum durum Desf.) Mohamed Ben Bachir variety and to select endophytic fungi for further evaluation of its antimicrobial, antioxidant activities and host growth promotion. A total of 20 endophytic fungi have been isolated. Antimicrobial activity was evaluated for crude ethyl acetate extracts using an agar diffusion assay. All extracts showed inhibitory activity on at least one or more pathogenic microorganism, with an average zone of inhibition varied between 7 mm to 25 mm, a large zone of 23 and 25mm against candida albicans and Escherichia coli respectively. The antioxidant capacity of the extracts was evaluated by beta-carotene/linoleic acid assay. Results showed that 70% of these extracts have antioxidant activity, exhibiting 50, 57% to 78, 96% inhibitions. While 30% from them, their inhibitory activity for oxidation of linoleic acid Were less than 50%. Growth promotion ability of these endophytes was tested on seed germination among ten isolates tested, two isolates showed significant growth promotion effects on wheat seeds. From the present work we can conclude that these microorganisms could be promising source of bioactive compounds, growth promotion and warrant further study.

Isolation, Purification and Characterization of Vinblastine and Vincristine from Endophytic Fungus Fusarium oxysporum Isolated from Catharanthus roseus

PubMed Central

Kumar, Ashutosh; Patil, Deepak; Rajamohanan, Pattuparambil Ramanpillai; Ahmad, Absar

2013-01-01

Endophytic fungi reside in a symbiotic fashion inside their host plants, mimic their chemistry and interestingly, produce the same natural products as their hosts and are thus being screened for the production of valuable compounds like taxol, camptothecin, podophyllotoxin, etc. Vinblastine and vincristine are excellent anti-cancer drugs but their current production using plants is non-abundant and expensive. In order to make these drugs readily available to the patients at affordable prices, we isolated the endophytic fungi from Catharanthus roseus plant and found a fungus AA-CRL-6 which produces vinblastine and vincristine in appreciable amounts. These drugs were purified by TLC and HPLC and characterized using UV-Vis spectroscopy, ESI-MS, MS/MS and 1H NMR. One liter of culture filtrate yielded 76 µg and 67 µg of vinblastine and vincristine respectively. This endophytic fungal strain was identified as Fusarium oxysporum based upon its cultural and morphological characteristics and internal transcribed spacer (ITS) sequence analysis. PMID:24066024

Isolation and characterization of endophytic taxol-producing fungi from Taxus chinensis.

PubMed

Liu, Kaihui; Ding, Xiaowei; Deng, Baiwan; Chen, Wenqiang

2009-09-01

This study investigated the endophytic fungi diversity of Taxus chinensis and screened the taxol-producing fungi in the host. A total of 115 endophytic fungi isolates obtained from bark segments of T. chinensis were grouped into 23 genera based on the morphological traits and sequence analysis of the internal transcribed spacers (ITS1-5.8S-ITS2), indicating endophytic fungi in T. chinensis are diverse and abundant. Diaporthe, Phomopsis (anamorph of Diaporthe), Acremonium, and Pezicula were the dominant genera, whereas the remaining genera were infrequent groups. The 13 representative species of the distinct genera were capable of producing taxol verified by reverse-phase high performance liquid chromatography (HPLC). Among the taxol-producing fungi, the yield of taxol produced by the Metarhizium anisopliae, H-27 was 846.1 microg l(-1) in reformative potato dextrose liquid medium, and the fungal taxol was further validated by mass spectrometry (MS). The taxol-producing fungi (92.3%) were infrequent communities, suggesting that infrequent fungi associated with T. chinensis might be a fascinating reservoir of taxol-generating fungi.

Evaluation of bioactive secondary metabolites from endophytic fungus Pestalotiopsis neglecta BAB-5510 isolated from leaves of Cupressus torulosa D.Don.

PubMed

Sharma, Deeksha; Pramanik, Avijit; Agrawal, Pavan Kumar

2016-12-01

Six endophytic fungi were isolated from Cupressus torulosa D.Don and identified phenotypically and genotypically. The fungal cultures were further grown and the culture was extracted by two organic solvents methanol and ethyl acetate. The screening was carried out using the agar well diffusion method against human pathogen such as Escherichia coli, Salmonella typhimurium, Bacillus subtilis and Staphylococcus aureus. Isolated strain of Pestalotiopsis sp. was showing prominent antibacterial activity. The crude methanol and ethyl acetate extract of Pestalotiopsis sp. showed MIC of 6.25 mg/mL for S. typhimurium and S. aureus which showed its efficacy as a potent antimicrobial. The phytochemical screening revealed the existence of a diverse group of secondary metabolites in the crude extracts of the endophytic fungi that resembled those in the host plant extracts. On the basis of phenotypic characteristics and rDNA sequencing of the ITS region of the endophyte was identified as P. neglecta which turned out to be a promising source of bioactive compounds. There is little known about endophytes from C. torulosa D.Don. In this paper we studied in detail the identification of isolated endophytic fungi P. neglecta from C. torulosa D.Don and characterization of its active metabolite compounds. The partially purified second fraction (PPF) extracted from the fungal culture supernatant was subjected to gas chromatography followed by mass spectrometry which revealed the presence of many phytochemicals. These results indicate that endophytic fungi P. neglecta isolated from medicinal plants could be a potential source for bioactive compounds and may find potential use in pharmaceutical industry.

Endophytic Fungi in Species of Artemisia.

PubMed

Cosoveanu, Andreea; Cabrera, Raimundo

2018-05-01

The genus Artemisia , a collection of ~400 hardy herbaceous plant and shrub species, is an important resource contributing to chemistry, medicine, agriculture, industry, and ecology. Its communities of endophytic fungi have only recently begun to be explored. Summarized from studies conducted on the fungal endophytes in Artemisia species, both fungal phylogenetic diversity and the associated bioactivity was examined. Isolations from 14 species of Artemisia have led to 51 genera of fungal endophytes, 28 families, and 18 orders. Endophytes belonged mainly to Ascomycota , except for two taxa of Cantharellales and Sporidiobolales , one taxon of Mucoromycota , and one species of Oomycota . The mostly common families were Pleosporaceae , Trichocomaceae , Leptosphaeriaceae , and Botryosphaeriaceae (relative abundance = 14.89, 8.51, 7.14 and 6.38, respectively). In the search for bioactive metabolites, 27 novel compounds were characterized and 22 metabolites were isolated between 2006 and 2017. The first study on endophytic fungi isolated from species of Artemisia was published but 18 years ago. This summary of recently acquired data illustrates the considerable diversity of biological purposes addressed by fungal endophytes of Artemisia spp.

Endophytes as sources of antibiotics.

PubMed

Martinez-Klimova, Elena; Rodríguez-Peña, Karol; Sánchez, Sergio

2017-06-15

Until a viable alternative can be accessible, the emergence of resistance to antimicrobials requires the constant development of new antibiotics. Recent scientific efforts have been aimed at the bioprospecting of microorganisms' secondary metabolites, with special emphasis on the search for antimicrobial natural products derived from endophytes. Endophytes are microorganisms that inhabit the internal tissues of plants without causing apparent harm to the plant. The present review article compiles recent (2006-2016) literature to provide an update on endophyte research aimed at finding metabolites with antibiotic activities. We have included exclusively information on endophytes that produce metabolites capable of inhibiting the growth of bacterial, fungal and protozoan pathogens of humans, animals and plants. Where available, the identified metabolites have been listed. In this review, we have also compiled a list of the bacterial and fungal phyla that have been isolated as endophytes as well as the plant families from which the endophytes were isolated. The majority of endophytes that produce antibiotic metabolites belong to either phylum Ascomycota (kingdom Fungi) or to phylum Actinobacteria (superkingdom Bacteria). Endophytes that produce antibiotic metabolites were predominant, but certainly not exclusively, from the plant families Fabaceae, Lamiaceae, Asteraceae and Araceae, suggesting that endophytes that produce antimicrobial metabolites are not restricted to a reduced number of plant families. The locations where plants (and inhabiting endophytes) were collected from, according to the literature, have been mapped, showing that endophytes that produce bioactive compounds have been collected globally. Copyright © 2016 Elsevier Inc. All rights reserved.

Metabolites from the endophytic fungus Sporormiella minimoides isolated from Hintonia latiflora

USDA-ARS?s Scientific Manuscript database

An extract of the solid cultures of Sporormiella minimoides (Sporormiaceae) isolated as an endophytic fungus from Hintonia latiflora (Rubiaceae), yielded three polyketides, 3,6-dimethoxy-8-methyl-1H,6H-benzo[de]isochromene-1,9-dione, 3-hydroxy-1,6,10-trimethoxy-8-methyl-1H,3H-benzo[de]isochromen-9-o...

Characterizing endophytic competence and plant growth promotion of bacterial endophytes inhabiting the seed endosphere of Rice.

PubMed

Walitang, Denver I; Kim, Kiyoon; Madhaiyan, Munusamy; Kim, Young Kee; Kang, Yeongyeong; Sa, Tongmin

2017-10-26

Rice (Oryza sativa L. ssp. indica) seeds as plant microbiome present both an opportunity and a challenge to colonizing bacterial community living in close association with plants. Nevertheless, the roles and activities of bacterial endophytes remain largely unexplored and insights into plant-microbe interaction are compounded by its complexity. In this study, putative functions or physiological properties associated with bacterial endophytic nature were assessed. Also, endophytic roles in plant growth and germination that may allow them to be selectively chosen by plants were also studied. The cultivable seed endophytes were dominated by Proteobacteria particularly class Gammaproteobacteria. Highly identical type strains were isolated from the seed endosphere regardless of the rice host's physiological tolerance to salinity. Among the type strains, Flavobacterium sp., Microbacterium sp. and Xanthomonas sp. were isolated from the salt-sensitive and salt-tolerant cultivars. PCA-Biplot ordination also showed that specific type strains isolated from different rice cultivars have distinguishing similar characteristics. Flavobacterium sp. strains are phosphate solubilizers and indole-3-acetic acid producers with high tolerance to salinity and osmotic stress. Pseudomonas strains are characterized as high siderophore producers while Microbacterium sp. and Xanthomonas sp. strains have very high pectinase and cellulase activity. Among the physiological traits of the seed endophytes, bacterial pectinase and cellulase activity are positively correlated as well as salt and osmotic tolerance. Overall characterization shows that majority of the isolates could survive in 4-8% salt concentration as well as in 0.6 M and 1.2 M sucrose solution. The activities of catalase, pectinase and cellulase were also observed in almost all of the isolates indicating the importance of these characteristics for survival and colonization into the seed endosphere. Seed bacterial endophytes also

Impact of Endophytic Microorganisms on Plants, Environment and Humans

PubMed Central

Nair, Dhanya N.; Padmavathy, S.

2014-01-01

Endophytes are microorganisms (bacteria or fungi or actinomycetes) that dwell within robust plant tissues by having a symbiotic association. They are ubiquitously associated with almost all plants studied till date. Some commonly found endophytes are those belonging to the genera Enterobacter sp., Colletotrichum sp., Phomopsis sp., Phyllosticta sp., Cladosporium sp., and so forth. Endophytic population is greatly affected by climatic conditions and location where the host plant grows. They produce a wide range of compounds useful for plants for their growth, protection to environmental conditions, and sustainability, in favour of a good dwelling place within the hosts. They protect plants from herbivory by producing certain compounds which will prevent animals from further grazing on the same plant and sometimes act as biocontrol agents. A large amount of bioactive compounds produced by them not only are useful for plants but also are of economical importance to humans. They serve as antibiotics, drugs or medicines, or the compounds of high relevance in research or as compounds useful to food industry. They are also found to have some important role in nutrient cycling, biodegradation, and bioremediation. In this review, we have tried to comprehend different roles of endophytes in plants and their significance and impacts on man and environment. PMID:24587715

Isolation and molecular identification of endophytic diazotrophs from seeds and stems of three cereal crops.

PubMed

Liu, Huawei; Zhang, Lei; Meng, Aihua; Zhang, Junbiao; Xie, Miaomiao; Qin, Yaohong; Faulk, Dylan Chase; Zhang, Baohong; Yang, Shushen; Qiu, Li

2017-01-01

Ten strains of endophytic diazotroph were isolated and identified from the plants collected from three different agricultural crop species, wheat, rice and maize, using the nitrogen-free selective isolation conditions. The nitrogen-fixing ability of endophytic diazotroph was verified by the nifH-PCR assay that showed positive nitrogen fixation ability. These identified strains were classified by 879F-RAPD and 16S rRNA sequence analysis. RAPD analyses revealed that the 10 strains were clustered into seven 879F-RAPD groups, suggesting a clonal origin. 16S rRNA sequencing analyses allowed the assignment of the 10 strains to known groups of nitrogen-fixing bacteria, including organisms from the genera Paenibacillus, Enterobacter, Klebsiella and Pantoea. These representative genus are not endophytic diazotrophs in the conventional sense. They may have obtained nitrogen fixation ability through lateral gene transfer, however, the evolutionary forces of lateral gene transfer are not well known. Molecular identification results from 16S rRNA analyses were also confirmed by morphological and biochemical data. The test strains SH6A and MZB showed positive effect on the growth of plants.

Isolation and Characterization of Saponin-Producing Fungal Endophytes from Aralia elata in Northeast China

PubMed Central

Wu, Hao; Yang, Hongyan; You, Xiangling; Li, Yuhua

2012-01-01

The purpose of this study was to investigate the diversity of endophytic fungi of Aralia elata distributed in Northeast China as well as their capacity to produce saponins. Ninety-six strains of endophytic fungi were isolated, and polymerase chain reaction (PCR) and sequencing were employed to identify the isolates. The saponin concentrations of the culture filtrates of representative strains were measured. The agar diffusion method was used to test antimicrobial activity, while high-performance liquid chromatography (HPLC) was employed to identify the saponins produced by representative strains. Alternaria, Botryosphaeria, Camarosporium, Cryptosporiopsis, Diaporthe, Dictyochaeta, Penicillium, Fusarium, Nectria, Peniophora, Schizophyllum, Cladosporium and Trichoderma species were isolated in this study. Overall, 25% of the isolates belonged to Diaporthe (Diaporthe eres), and 12.5% belonged to Alternaria. The highest concentration of saponins was produced by G22 (2.049 mg/mL). According to the results of the phylogenetic analysis, G22 belonged to the genus Penicillium. The culture filtrate of G22 exhibited antibacterial activity against Staphylococcus aureus, and ginsenosides Re and Rb2 were detected in G22 culture filtrates by HPLC. PMID:23203194

Isolation and characterization of plant growth promoting endophytic diazotrophic bacteria from Korean rice cultivars.

PubMed

Ji, Sang Hye; Gururani, Mayank Anand; Chun, Se-Chul

2014-01-20

We have isolated 576 endophytic bacteria from the leaves, stems, and roots of 10 rice cultivars and identified 12 of them as diazotrophic bacteria using a specific primer set of nif gene. Through 16S rDNA sequence analysis, nifH genes were confirmed in the two species of Penibacillus, three species of Microbacterium, three Bacillus species, and four species of Klebsiella. Rice seeds treated with these plant growth-promoting bacteria (PGPB) showed improved plant growth, increased height and dry weight and antagonistic effects against fungal pathogens. In addition, auxin and siderophore producing ability, and phosphate solubilizing activity were studied for the possible mechanisms of plant growth promotion. Among 12 isolates tested, 10 strains have shown higher auxin producing activity, 6 isolates were confirmed as strains with high siderophore producing activity while 4 isolates turned out to have high phosphate-solubilizing activity. These results strongly suggest that the endophytic diazotrophic bacteria characterized in this study could be successfully used to promote plant growth and inducing fungal resistance in plants. Copyright © 2013 Elsevier GmbH. All rights reserved.

Seaweed temporal distribution in southeast coast of Peninsular Malaysia and isolation of endophytic fungi

NASA Astrophysics Data System (ADS)

Zainee, Nur Farah Ain; Ismail, Ahmad; Ibrahim, Nazlina; Ismail, Asmida

2018-04-01

Temporal study of seaweeds was carried out between on February 2015 and November 2015 at Kampung Jawa Darat and Kampung Sungai Buntu at Pengerang, Johor, Malaysia. The research objectives were to study the diversity of seaweed and to determine the presence of fungal endophyte in the seaweed. The diversity of seaweed in the sampling site was calculated by using quadrat with 25 meter line transect by 3 replication for each site. The specimen were identified and processed in laboratory and kept for reference in the Algae Herbarium, Universiti Kebangsaan Malaysia. The specimen for fungal endophyte isolation was collected randomly by choosing the complete thallus, transferred into sterile zip-lock plastic bag and kept in freezer until used. From this study, a total of 29 species have been successfully identified including 12 species of Chlorophyta, 2 species of Phaeophyta and 14 species of Rhodophyta. From February to November 2015, the number of species highly varied and a significant change in community structure was noted. Kampung Sungai Buntu shows the highest diversity throughout the study compared to Kampung Jawa Darat. Eighteen seaweed species were screened for the presence of fungal endophyte, Sargassum polycystum shows the highest number of fungal endophyte. This study documented the seaweed diversity in two sites at Pengerang, Johor that accommodates fungal endophytes.

An endophytic Basidiomycete, Grammothele lineata, isolated from Corchorus olitorius, produces paclitaxel that shows cytotoxicity

PubMed Central

Das, Avizit; Rahman, Mohammad Imtiazur; Ferdous, Ahlan Sabah; Amin, Al-; Rahman, Mohammad Mahbubur; Nahar, Nilufar; Uddin, Md. Aftab; Islam, Mohammad Riazul; Khan, Haseena

2017-01-01

Grammothele lineata, an endophyte isolated in our laboratory from jute (Corchorus olitorius acc. 2015) was found to be a substantial paclitaxel producer. Taxol and its related compounds, produced by this endophyte were extracted by growing the fungus in simple nutrient media (potato dextrose broth, PDB). Taxol was identified and characterized by different analytical techniques (TLC, HPLC, FTIR, LC-ESI-MS/MS) following its extraction by ethyl acetate. In PDB media, this fungus was found to produce 382.2 μgL-1 of taxol which is about 7.6 x103 fold higher than the first reported endophytic fungi, Taxomyces andreanae. The extracted taxol exhibited cytotoxic activity in an in vitro culture of HeLa cancer cell line. The fungal extract also exhibited antifungal and antibacterial activities against different pathogenic strains. This is the first report of a jute endophytic fungus harboring the capacity to produce taxol and also the first reported taxol producing species that belongs to the Basidiomycota phylum, so far unknown to be a taxol producer. These findings suggest that the fungal endophyte, Grammothele lineata can be an excellent source of taxol and can also serve as a potential species for chemical and genetic engineering to enhance further the production of taxol. PMID:28636663

An endophytic Basidiomycete, Grammothele lineata, isolated from Corchorus olitorius, produces paclitaxel that shows cytotoxicity.

PubMed

Das, Avizit; Rahman, Mohammad Imtiazur; Ferdous, Ahlan Sabah; Amin, Al-; Rahman, Mohammad Mahbubur; Nahar, Nilufar; Uddin, Md Aftab; Islam, Mohammad Riazul; Khan, Haseena

2017-01-01

Grammothele lineata, an endophyte isolated in our laboratory from jute (Corchorus olitorius acc. 2015) was found to be a substantial paclitaxel producer. Taxol and its related compounds, produced by this endophyte were extracted by growing the fungus in simple nutrient media (potato dextrose broth, PDB). Taxol was identified and characterized by different analytical techniques (TLC, HPLC, FTIR, LC-ESI-MS/MS) following its extraction by ethyl acetate. In PDB media, this fungus was found to produce 382.2 μgL-1 of taxol which is about 7.6 x103 fold higher than the first reported endophytic fungi, Taxomyces andreanae. The extracted taxol exhibited cytotoxic activity in an in vitro culture of HeLa cancer cell line. The fungal extract also exhibited antifungal and antibacterial activities against different pathogenic strains. This is the first report of a jute endophytic fungus harboring the capacity to produce taxol and also the first reported taxol producing species that belongs to the Basidiomycota phylum, so far unknown to be a taxol producer. These findings suggest that the fungal endophyte, Grammothele lineata can be an excellent source of taxol and can also serve as a potential species for chemical and genetic engineering to enhance further the production of taxol.

Interspecies variation of Kitasatospora recifensis endophytic from yam bean producing thermostable amylases in alternative media.

PubMed

Stamford, Tania Lucia Montenegro; Stamford, Thayza Christina Montenegro; Stamford, Newton Pereira; Santos, Carolina Etienne Rosália Silva; de Lyra, Maria do Carmo Catanho Pereira; Ha-Park, Yong; Bae, Jin-Won; Araújo, Janete Magali

2007-12-01

An endophytic actinomycete isolated from tubers of yam beam (Pachyrhizus erosus L. Urban) was classified as a novel species nominated Kitasatospora recifensis based in phenotypic and genotypic analysis (16S rDNA gene sequence). Monosporic culture using specific ISP2 media revealed three interspecies, which were identified by DNA southern hybridization (Wild strain 13817 W, Aerial Mycelium strain 13817 AM and Vegetative Mycelium strain 13817 VM). The strains were tested for the production of amylolitic enzymes in alternative media. Maximum yields for both enzymes were observed in starch-casein. Higher α-amylase was obtained with strain 13817 W in starch-urea, and amyloglucosidase with strain 13817 AM in starch-ammonium that are economic sources and may be important for industrial purposes. Type strain (DAUFPE 13817(T) = KCTC 9972(T )= DSM 44943(T)).

Acremonium camptosporum isolated as an endophyte of Bursera simaruba from Yucatan Peninsula, Mexico

USDA-ARS?s Scientific Manuscript database

This paper draws on morphological and molecular analyses to determinate the systematic position of an interesting endophytic fungus isolated from the leaves of Bursera simaruba, a tree of semideciduous dry tropical forest at El Eden Ecological Reserve. The cultured strain develops the characteristic...

The Madeira Archipelago As a Significant Source of Marine-Derived Actinomycete Diversity with Anticancer and Antimicrobial Potential

PubMed Central

Prieto-Davó, Alejandra; Dias, Tiago; Gomes, Sofia E.; Rodrigues, Sara; Parera-Valadez, Yessica; Borralho, Pedro M.; Pereira, Florbela; Rodrigues, Cecilia M. P.; Santos-Sanches, Ilda; Gaudêncio, Susana P.

2016-01-01

Marine-derived actinomycetes have demonstrated an ability to produce novel compounds with medically relevant biological activity. Studying the diversity and biogeographical patterns of marine actinomycetes offers an opportunity to identify genera that are under environmental pressures, which may drive adaptations that yield specific biosynthetic capabilities. The present study describes research efforts to explore regions of the Atlantic Ocean, specifically around the Madeira Archipelago, where knowledge of the indigenous actinomycete diversity is scarce. A total of 400 actinomycetes were isolated, sequenced, and screened for antimicrobial and anticancer activities. The three most abundant genera identified were Streptomyces, Actinomadura, and Micromonospora. Phylogenetic analyses of the marine OTUs isolated indicated that the Madeira Archipelago is a new source of actinomycetes adapted to life in the ocean. Phylogenetic differences between offshore (>100 m from shore) and nearshore (< 100 m from shore) populations illustrates the importance of sampling offshore in order to isolate new and diverse bacterial strains. Novel phylotypes from chemically rich marine actinomycete groups like MAR4 and the genus Salinispora were isolated. Anticancer and antimicrobial assays identified Streptomyces, Micromonospora, and Salinispora as the most biologically active genera. This study illustrates the importance of bioprospecting efforts at unexplored regions of the ocean to recover bacterial strains with the potential to produce novel and interesting chemistry. PMID:27774089

Exploring plant growth-promotion actinomycetes from vermicompost and rhizosphere soil for yield enhancement in chickpea

PubMed Central

Sreevidya, M.; Gopalakrishnan, S.; Kudapa, H.; Varshney, R.K.

2016-01-01

The main objective of the present study was to isolate and characterize actinomycetes for their plant growth-promotion in chickpea. A total of 89 actinomycetes were screened for their antagonism against fungal pathogens of chickpea by dual culture and metabolite production assays. Four most promising actinomycetes were evaluated for their physiological and plant growth-promotion properties under in vitro and in vivo conditions. All the isolates exhibited good growth at temperatures from 20 °C to 40 °C, pH range of 7–11 and NaCl concentrations up to 8%. These were also found highly tolerant to Bavistin, slightly tolerant to Thiram and Captan (except VAI-7 and VAI-40) but susceptible to Benlate and Ridomil at field application levels and were found to produce siderophore, cellulase, lipase, protease, chitinase (except VAI-40), hydrocyanic acid (except VAI-7 and VAI-40), indole acetic acid and β-1,3-glucanase. When the four actinomycetes were evaluated for their plant growth-promotion properties under field conditions on chickpea, all exhibited increase in nodule number, shoot weight and yield. The actinomycetes treated plots enhanced total N, available P and organic C over the un-inoculated control. The scanning electron microscope studies exhibited extensive colonization by actinomycetes on the root surface of chickpea. The expression profiles for indole acetic acid, siderophore and β-1,3-glucanase genes exhibited up-regulation for all three traits and in all four isolates. The actinomycetes were identified as Streptomyces but different species in the 16S rDNA analysis. It was concluded that the selected actinomycetes have good plant growth-promotion and biocontrol potentials on chickpea. PMID:26887230

Cellulase and Xylanase Production from Three Isolates of Indigenous Endophytic Fungi

NASA Astrophysics Data System (ADS)

Yopi; Tasia, W.; Melliawati, R.

2017-12-01

Cellulases and hemicellulases have good potential to be used in energy production, in pulp, paper, textile industries, as well as in animal feed industries. Moreover, its utilization in food industries also cannot be ignored, among others, cellulase and xylanase roles in bakery, wine, and fruit and vegetables juice production. One of the potential enzyme source is endophytic fungi. Object of this study is to explore the potency of endophytic fungi isolated from medicinal plants as source of cellulolytic and xylanolytic enzymes. HL.47F.216 is endophytic fungi isolated from traditional medicinal plants ironwood tree was determined as xylanase producer. HL.51F.235 from pin-flower tree is cellulase producer, while CBN.6F.29 which produces both xylanase and cellulase is originated from Madagascar periwinkle. HL.47F.216 showed 2.5 cm in clear zone diameter and its xylanase activity was 0.262 U/mL with optimum condition pH 7 at 50°C. HL.51F.235 showed 2.4 cm clear zone diameter and 0.239 U/mL of cellulase activity at pH 5 and 70°C. CBN.6F.29 showed 2.8 cm and 0.394 U/mL (pH 5, 40°C) for its cellulase activity, while 2.3 cm and 0.439 U/mL (pH 8, 70°C) for its xylanase activity. Xylanase from HL.47F.216 and CBN.6F.29 showed low molecular masses of 20 kDa and 37-50 kDa, respectively. Molecular masses for cellulases from HL.51F.235 and CBN.6F.29 were 25 and 50 kDa for HL.51F.235 and 100 kDa for CBN.6F.29. Based on macroscopic and microscopic identification, fungal isolate CBN.6F.29 is a member of Class Coelomycetes, while HL.47F.216 was Acremonium sp. and HL.51F.235 was Aspergillus nigri.

Enumerating actinomycetes in compost bioaerosols at source—Use of soil compost agar to address plate 'masking'

NASA Astrophysics Data System (ADS)

Taha, M. P. M.; Drew, G. H.; Tamer Vestlund, A.; Aldred, D.; Longhurst, P. J.; Pollard, S. J. T.

Actinomycetes are the dominant bacteria isolated from bioaerosols sampled at composting facilities. Here, a novel method for the isolation of actinomycetes is reported, overcoming masking of conventional agar plates, as well as reducing analysis time and costs. Repeatable and reliable actinomycetes growth was best achieved using a soil compost media at an incubation temperature of 44 °C and 7 days' incubation. The results are of particular value to waste management operators and their advisors undertaking regulatory risk assessments that support environmental approvals for compost facilities.

Antibacterial activity of alkaloids produced by endophytic fungus Aspergillus sp. EJC08 isolated from medical plant Bauhinia guianensis.

PubMed

Pinheiro, Eduardo Antonio A; Carvalho, Josiwander Miranda; dos Santos, Diellem Cristina P; Feitosa, André de Oliveira; Marinho, Patrícia Santana B; Guilhon, Giselle Maria Skelding Pinheiro; de Souza, Afonso Duarte L; da Silva, Felipe Moura A; Marinho, Andrey Moacir do R

2013-01-01

Bauhinia guianensis is a typical plant in the Amazon region belonging to the family Leguminosea, used by local populations for the treatment of infectious and renal diseases. Previous work on the plant B. guianensis led to the isolation of substances with anti-inflammatory and analgesic activities. Thus, compounds isolated from B. guianensis with antimicrobial activities had not been identified. Given that there is a possibility of biological activity reported for a given plant being found in the endophytic fungi, we decided to isolate endophytic fungi from B. guianensis and test their antimicrobial activities. The alkaloids known as fumigaclavine C and pseurotin A were isolated by column chromatography and identified by 1D and 2D NMR techniques and mass spectrometry. The alkaloids are first reported as broad-spectrum antibacterial agents with good activity.

Molecular Characterisation of Endophytic Fungi from Roots of Wild Banana (Musa acuminata)

PubMed Central

Zakaria, Latiffah; Jamil, Muhamad Izham Muhamad; Anuar, Intan Sakinah Mohd

2016-01-01

Endophytic fungi inhabit apparently healthy plant tissues and are prevalent in terrestrial plants, especially root tissues, which harbour a wide assemblage of fungal endophytes. Therefore, this study focused on the isolation and characterisation of endophytic fungi from the roots of wild banana (Musa acuminata). A total of 31 isolates of endophytic fungi were isolated from 80 root fragments. The endophytic fungi were initially sorted according to morphological characteristics and identified using the sequences of the translation elongation factor-1α (TEF-1α) gene of Fusarium spp. and the Internal Transcribed Spacer (ITS) regions of other fungi. The most common fungal isolates were species of the genus Fusarium, which were identified as F. proliferatum, Fusarium sp., F. solani species complex, and F. oxysporum. Other isolated endophytic fungi included Curvularia lunata, Trichoderma atroviride, Calonectria gracilis, Rhizoctonia solani, Bionectria ochroleuca, and Stromatoneurospora phoenix (Xylariceae). Several of the fungal genera, such as Fusarium, Trichoderma, Rhizoctonia, and Xylariceae, are among the common fungal endophytes reported in plants. This study showed that the roots of wild banana harbour a diverse group of endophytic fungi. PMID:27019688

Red Soils Harbor Diverse Culturable Actinomycetes That Are Promising Sources of Novel Secondary Metabolites

PubMed Central

Guo, Xiaoxuan; Liu, Ning; Li, Xiaomin; Ding, Yun; Shang, Fei; Gao, Yongsheng; Ruan, Jisheng

2015-01-01

Red soils, which are widely distributed in tropical and subtropical regions of southern China, are characterized by low organic carbon, high content of iron oxides, and acidity and, hence, are likely to be ideal habitats for acidophilic actinomycetes. However, the diversity and biosynthetic potential of actinomycetes in such habitats are underexplored. Here, a total of 600 actinomycete strains were isolated from red soils collected in Jiangxi Province in southeast China. 16S rRNA gene sequence analysis revealed a high diversity of the isolates, which were distributed into 26 genera, 10 families, and 7 orders within the class Actinobacteria; these taxa contained at least 49 phylotypes that are likely to represent new species within 15 genera. The isolates showed good physiological potentials for biosynthesis and biocontrol. Chemical screening of 107 semirandomly selected isolates spanning 20 genera revealed the presence of at least 193 secondary metabolites from 52 isolates, of which 125 compounds from 39 isolates of 12 genera were putatively novel. Macrolides, polyethers, diketopiperazines, and siderophores accounted for most of the known compounds. The structures of six novel compounds were elucidated, two of which had a unique skeleton and represented characteristic secondary metabolites of a putative novel Streptomyces phylotype. These results demonstrate that red soils are rich reservoirs for diverse culturable actinomycetes, notably members of the families Streptomycetaceae, Pseudonocardiaceae, and Streptosporangiaceae, with the capacity to synthesize novel bioactive compounds. PMID:25724963

Anti-phytopathogen potential of endophytic actinobacteria isolated from tomato plants (Lycopersicon esculentum) in southern Brazil, and characterization of Streptomyces sp. R18(6), a potential biocontrol agent.

PubMed

de Oliveira, Margaroni Fialho; da Silva, Mariana Germano; Van Der Sand, Sueli T

2010-09-01

Tomato plants (Lycopersicon esculentum) are highly susceptible to phytopathogen attack. The resulting intensive application of pesticides on tomato crops can affect the environment and health of humans and animals. The objective of this study was to select potential biocontrol agents among actinobacteria from tomato plants, in a search for alternative phytopathogen control. We evaluated 70 endophytic actinobacteria isolated from tomato plants in southern Brazil, testing their antimicrobial activity, siderophore production, indoleacetic acid production, and phosphate solubility. The actinomycete isolate with the highest antimicrobial potential was selected using the agar-well diffusion method, in order to optimize conditions for the production of compounds with antimicrobial activity. For this study, six growth media (starch casein-SC, ISP2, Bennett's, Sahin, Czapek-Dox, and TSB), three temperatures (25 degrees C, 30 degrees C, and 35 degrees C) and different pH were tested. Of the actinobacteria tested, 88.6% showed antimicrobial activity against at least one phytopathogen, 72.1% showed a positive reaction for indoleacetic acid production, 86.8% produced siderophores and 16.2% showed a positive reaction for phosphate solubility. Isolate R18(6) was selected due to its antagonistic activity against all phytopathogenic microorganisms tested in this study. The best conditions for production were observed in the SC medium, at 30 degrees C and pH 7.0. The isolate R18(6) showed close biochemical and genetic similarity to Streptomyces pluricolorescens. Copyright 2010 Elsevier Masson SAS. All rights reserved.

Endophytic bacterial flora in root and stem tissues of black pepper (Piper nigrum L.) genotype: isolation, identification and evaluation against Phytophthora capsici.

PubMed

Aravind, R; Kumar, A; Eapen, S J; Ramana, K V

2009-01-01

To isolate and identify black pepper (Piper nigrum L) associated endophytic bacteria antagonistic to Phytophthora capsici causing foot rot disease. Endophytic bacteria (74) were isolated, characterized and evaluated against P. capsici. Six genera belong to Pseudomonas spp (20 strains), Serratia (1 strain), Bacillus spp. (22 strains), Arthrobacter spp. (15 strains), Micrococcus spp. (7 strains), Curtobacterium sp. (1 strain) and eight unidentified strains were isolated from internal tissues of root and stem. Three isolates, IISRBP 35, IISRBP 25 and IISRBP 17 were found effective for Phytophthora suppression in multilevel screening assays which recorded over 70% disease suppression in greenhouse trials. A species closest match (99% similarity) of IISRBP 35 was established as Pseudomonas aeruginosa (Pseudomonas EF568931), IISRBP 25 as P. putida (Pseudomonas EF568932), and IISRBP 17 as Bacillus megaterium (B. megaterium EU071712) based on 16S rDNA sequencing. Black pepper associated P. aeruginosa, P. putida and B. megaterium were identified as effective antagonistic endophytes for biological control of Phytophthora foot rot in black pepper. This work provides the first evidence for endophytic bacterial diversity in black pepper stem and roots, with biocontrol potential against P. capsici infection.

Biotransformation of ginsenoside Rb1 to ginsenoside C-K by endophytic fungus Arthrinium sp. GE 17-18 isolated from Panax ginseng.

PubMed

Fu, Y; Yin, Z-H; Wu, L-P; Yin, C-R

2016-09-01

This research aimed to isolate β-glycosidase-producing endophytic fungus in Panax ginseng to achieve biotransformation of ginsenoside Rb1 to ginsenoside C-K. Of these 15 β-glucosidase-producing endophytic fungus isolated from ginseng roots, a β-glucosidase-producing endophytic fungi GE 17-18 could hydrolyse major ginsenosides Rb1 to minor ginsenoside C-K with metabolic pathways: ginsenoside Rb1→ginsenoside Rd→ginsenoside F2→ginsenoside C-K. Phylogenetic analysis of ITS gene sequences indicated that the strain GE 17-18 belongs to the genus Arthrinium and is most closely related to Arthrinium sp. HQ832803.1. This is the first study to provide information of cultivable β-glycosidase-producing Endophytic fungus in Panax ginseng. The strain GE 17-18 has potential to be applied on the preparation for minor ginsenoside C-K in pharmaceutical industry. © 2016 The Society for Applied Microbiology.

Anticancer property of sediment actinomycetes against MCF-7 and MDA-MB-231 cell lines.

PubMed

Ravikumar, S; Fredimoses, M; Gnanadesigan, M

2012-02-01

To investigate the anticancer property of marine sediment actinomycetes against two different breast cancer cell lines. In vitro anticancer activity was carried out against breast (MCF-7 and MDA-MB-231) cancer cell lines. Partial sequences of the 16s rRNA gene, phylogenetic tree construction, multiple sequence analysis and secondary structure analysis were also carried out with the actinomycetes isolates. Of the selected five actinomycete isolates, ACT01 and ACT02 showed the IC50 value with (10.13±0.92) and (22.34±5.82) µg/mL concentrations, respectively for MCF-7 cell line at 48 h, but ACT01 showed the minimum (18.54±2.49 µg/mL) level of IC50 value with MDA-MB-231 cell line. Further, the 16s rRNA partial sequences of ACT01, ACT02, ACT03, ACT04 and ACT05 isolates were also deposited in NCBI data bank with the accession numbers of GQ478246, GQ478247, GQ478248, GQ478249 and GQ478250, respectively. The phylogenetic tree analysis showed that, the isolates of ACT02 and ACT03 were represented in group I and III, respectively, but ACT01 and ACT02 were represented in group II. The multiple sequence alignment of the actinomycete isolates showed that, the maximum identical conserved regions were identified with the nucleotide regions of 125 to 221st base pairs, 65 to 119th base pairs and 55, 48 and 31st base pairs. Secondary structure prediction of the 16s rRNA showed that, the maximum free energy was consumed with ACT03 isolate (-45.4 kkal/mol) and the minimum free energy was consumed with ACT04 isolate (-57.6 kkal/mol). The actinomycete isolates of ACT01 and ACT02 (GQ478246 and GQ478247) which are isolated from sediment sample can be further used as anticancer agents against breast cancer cell lines.

Metabolism of carbamazepine in plant roots and endophytic rhizobacteria isolated from Phragmites australis.

PubMed

Sauvêtre, Andrés; May, Robert; Harpaintner, Rudolf; Poschenrieder, Charlotte; Schröder, Peter

2018-01-15

Carbamazepine (CBZ) is a pharmaceutical frequently categorized as a recalcitrant pollutant in the aquatic environment. Endophytic bacteria previously isolated from reed plants have shown the ability to promote growth of their host and to contribute to CBZ metabolism. In this work, a horseradish (Armoracia rusticana) hairy root (HR) culture has been used as a plant model to study the interactions between roots and endophytic bacteria in response to CBZ exposure. HRs could remove up to 5% of the initial CBZ concentration when they were grown in spiked Murashige and Skoog (MS) medium. Higher removal rates were observed when HRs were inoculated with the endophytic bacteria Rhizobium radiobacter (21%) and Diaphorobacter nitroreducens (10%). Transformation products resulting from CBZ degradation were identified using liquid chromatography-ultra high-resolution quadrupole time of flight mass spectrometry (LC-UHR-QTOF-MS). CBZ metabolism could be divided in four pathways. Metabolites involving GSH conjugation and 2,3-dihydroxylation, as well as acridine related compounds are described in plants for the first time. This study presents strong evidence that xenobiotic metabolism and degradation pathways in plants can be modulated by the interaction with their endophytic community. Hence it points to plausible applications for the elimination of recalcitrant compounds such as CBZ from wastewater in CWs. Copyright © 2017 Elsevier B.V. All rights reserved.

Diversity and Antimicrobial Activity of Culturable Endophytic Fungi Isolated from Moso Bamboo Seeds

PubMed Central

Cai, Chun-Ju; Fan, Li; Gao, Jian; Hou, Cheng-Lin

2014-01-01

Bamboos, regarded as therapeutic agents in ethnomedicine, have been used to inhibit inflammation and enhance natural immunity for a long time in Asia, and there are many bamboo associated fungi with medical and edible value. In the present study, a total of 350 fungal strains were isolated from the uncommon moso bamboo (Phyllostachys edulis) seeds for the first time. The molecular diversity of these endophytic fungi was investigated and bioactive compound producers were screened for the first time. All the fungal endophytes were categorized into 69 morphotypes according to culturable characteristics and their internal transcriber spacer (ITS) regions were analyzed by BLAST search with the NCBI database. The fungal isolates showed high diversity and were divided in Ascomycota (98.0%) and Basidiomycota (2.0%), including at least 19 genera in nine orders. Four particular genera were considered to be newly recorded bambusicolous fungi, including Leptosphaerulina, Simplicillium, Sebacina and an unknown genus in Basidiomycetes. Furthermore, inhibitory effects against clinical pathogens and phytopathogens were screened preliminarily and strains B09 (Cladosporium sp.), B34 (Curvularia sp.), B35 (undefined genus 1), B38 (Penicillium sp.) and zzz816 (Shiraia sp.) displayed broad-spectrum activity against clinical bacteria and yeasts by the agar diffusion method. The crude extracts of isolates B09, B34, B35, B38 and zzz816 under submerged fermentation, also demonstrated various levels of bioactivities against bambusicolous pathogenic fungi. This study is the first report on the antimicrobial activity of endophytic fungi associated with moso bamboo seeds, and the results show that they could be exploited as a potential source of bioactive compounds and plant defense activators. In addition, it is the first time that strains of Shiraia sp. have been isolated and cultured from moso bamboo seeds, and one of them (zzz816) could produce hypocrellin A at high yield, which is

Complete Genome Sequence of Micromonospora Strain L5, a Potential Plant-Growth-Regulating Actinomycete, Originally Isolated from Casuarina equisetifolia Root Nodules

DOE PAGES

Hirsch, Ann M.; Alvarado, Johana; Bruce, David; ...

2013-09-26

Micromonospora species live in diverse environments and exhibit a broad range of functions, including antibiotic production, biocontrol, and degradation of complex polysaccharides. To learn more about these versatile actinomycetes, we sequenced the genome of strain L5, originally isolated from root nodules of an actinorhizal plant growing in Mexico.

Isolation, taxonomic analysis, and phenotypic characterization of bacterial endophytes present in alfalfa (Medicago sativa) seeds.

PubMed

López, José Luis; Alvarez, Florencia; Príncipe, Analía; Salas, María Eugenia; Lozano, Mauricio Javier; Draghi, Walter Omar; Jofré, Edgardo; Lagares, Antonio

2018-02-10

A growing body of evidence has reinforced the central role of microbiomes in the life of sound multicellular eukaryotes, thus more properly described as true holobionts. Though soil was considered a main source of plant microbiomes, seeds have been shown to be endophytically colonized by microorganisms thus representing natural carriers of a selected microbial inoculum to the young seedlings. In this work we have investigated the type of culturable endophytic bacteria that are carried within surface-sterilized alfalfa seeds. MALDI-TOF analysis revealed the presence of bacteria that belonged to 40 separate genera, distributed within four taxa (Proteobacteria, Actinobacteria, Firmicutes, and Bacteroidetes). Nonsymbiotic members of the Rhizobiaceae family were also found. The evaluation of nine different in-vitro biochemical activities demonstrated isolates with complex combinations of traits that, upon a Principal-Component-Analysis, could be classified into four phenotypic groups. That isolates from nearly half of the genera identified had been able to colonize alfalfa plants grown under axenic conditions was remarkable. Further analyses should be addressed to investigating the colonization mechanisms of the alfalfa seeds, the evolutionary significance of the alfalfa-seed endophytes, and also how after germination the seed microbiome competes with spermospheric and rhizospheric soil bacteria to colonize newly emerging seedlings. Copyright © 2018 Elsevier B.V. All rights reserved.

Isolation of Antagonistic Endophytes from Banana Roots against Meloidogyne javanica and Their Effects on Soil Nematode Community

PubMed Central

Su, Lanxi; Shen, Zongzhuan; Ruan, Yunze; Tao, Chengyuan; Chao, Yifan; Li, Rong; Shen, Qirong

2017-01-01

Banana production is seriously hindered by Meloidogyne spp. all over the world. Endophytes are ideal candidates compared to pesticides as an environmentally benign agent. In the present study, endophytes isolated from banana roots infected by Meloidogyne spp. with different disease levels were tested in vitro, and in sterile and nature banana monoculture soils against Meloidogyne javanica. The proportion of antagonistic endophytes were higher in the roots of middle and high disease levels. Among those, bacteria were dominant, and Pseudomonas spp., Bacillus spp. and Streptomyces spp. showed more abundant populations. One strain, named as SA, with definite root inner-colonization ability was isolated and identified as Streptomyces sp. This strain showed an inhibiting rate of >50% in vitro and biocontrol efficiency of 70.7% in sterile soil against Meloidogyne javanica, compared to the control. Greenhouse experiment results showed that the strain SA exhibits excellent biological control ability for plant-parasites both in roots and in root-knot nematode infested soil. SA treatment showed a higher number of bacterivores, especially Mesorhabditis and Cephalobus. The maturity index was significantly lower, while enrichment index (EI) was significantly higher in the SA treatment. In conclusion, this study presents an important potential application of the endophytic strain Streptomyces sp. for the control of plant-parasitic nematodes, especially Meloidogyne javanica, and presents the effects on the associated variation of the nematode community. PMID:29123509

Metabolomic-Guided Isolation of Bioactive Natural Products from Curvularia sp., an Endophytic Fungus of Terminalia laxiflora.

PubMed

Tawfike, Ahmed F; Abbott, Grainne; Young, Louise; Edrada-Ebel, RuAngelie

2018-02-01

Endophytic fungi associated with medicinal plants are a potential source of novel chemistry and biology. Metabolomic tools were successfully employed to compare the metabolite fingerprints of solid and liquid culture extracts of endophyte Curvularia sp. isolated from the leaves of Terminalia laxiflora . Natural product databases were used to dereplicate metabolites in order to determine known compounds and the presence of new natural products. Multivariate analysis highlighted the putative metabolites responsible for the bioactivity of the fungal extract and its fractions on NF- κ B and the myelogenous leukemia cell line K562. Metabolomic tools and dereplication studies using high-resolution electrospray ionization mass spectrometry directed the fractionation and isolation of the bioactive components from the fungal extracts. This resulted in the isolation of N -acetylphenylalanine (1: ) and two linear peptide congeners of 1: : dipeptide N -acetylphenylalanyl-L-phenylalanine (2: ) and tripeptide N -acetylphenylalanyl-L-phenylalanyl-L-leucine (3: ). Georg Thieme Verlag KG Stuttgart · New York.

The detection of diverse aminoglycoside phosphotransferases within natural populations of actinomycetes.

PubMed

Anderson, A S; Clark, D J; Gibbons, P H; Sigmund, J M

2002-08-01

The conserved nature of the genes that code for actinomycete secondary metabolite biosynthetic pathways suggests a common evolutionary ancestor and incidences of lateral gene transfer. Resistance genes associated with these biosynthetic pathways also display a high degree of similarity. Actinomycete aminoglycoside phosphotransferase antibiotic resistance enzymes (APH) are coded for by such genes and are therefore good targets for evaluating the bioactive potential of actinomycetes. A set of universal PCR primers for APH encoding genes was used to probe genomic DNA from three collections of actinomycetes to determine the utility of molecular screening. An additional monitoring of populations for the predominance of specific classes of enzymes to predict the potential of environmental sites for providing isolates with interesting metabolic profiles. Approximately one-fifth of all isolates screened gave a positive result by PCR. The PCR products obtained were sequenced and compared to existing APH family members. Sequence analysis resolved the family into nine groups of which six had recognizable phenotypes: 6'-phosphotransferase (APH(6)), 3'-phosphotransferase (APH(3)), hydroxyurea phosphotransferase (HUR), peptide phosphotransferase, hygromycin B phosphotransferase (APH(7")) and oxidoreductase. The actinomycetes screened fell into seven groups, including three novel groups with unknown phenotypes. The strains clustered according to the environmental site from where they were obtained, providing evidence for the movement of these genes within populations. The value of this as a method for obtaining novel compounds and the significance to the ecology of antibiotic biosynthesis are discussed.

Biocontrol of verticillium wilt and colonization of cotton plants by an endophytic bacterial isolate.

PubMed

Li, C-H; Shi, L; Han, Q; Hu, H-L; Zhao, M-W; Tang, C-M; Li, S-P

2012-09-01

To explore biocontrol potential of 39 DAEB isolates (doubly antagonistic towards both Verticillium dahliae Kleb and Fusarium oxysporum) against verticillium wilt of cotton and to elucidate colonization and category characteristics of an endophytic bacterium with significant biocontrol activity. Thirty-nine antagonistic endophytic bacteria strains were tested for their ability to control verticillium wilt in cotton plants caused by a defoliating pathotype of V. dahliae 107 in cotton under controlled conditions. The biocontrol trial revealed that an endophytic bacterium, designated HA02, showed a significant biocontrol activity to V. dahliae 107. After cotton seedlings were inoculated with a gfp gene-tagged HA02 (HA02-gfp), HA02-gfp populations were higher in the root than in the stem; in addition, the HA02-gfp was distributed in the maturation zone of cotton root. Furthermore, HA02-gfp also colonized seedlings of maize, rape and soybean after the bacteria inoculation. Phylogenetic trees based on 16S rDNA sequences combined with morphological, physiological and identification showed that the bacterium belongs to the Enterobacter genus. Our results showed that only 1 of 39 DAEB isolates demonstrated more efficient biocontrol potential towards V. dahliae 107 in greenhouse and field trials. HA02-gfp mainly colonized cotton in roots. In addition, we quantitatively observed HA02 colonization in other hosts. HA02 belongs to the Enterobacter genus. This is the first study on biocontrol to defoliating pathotype of V. dahliae Kleb by endophytic bacteria. The HA02 showed effective biocontrol to V. dahliae 107 in greenhouse and field trials. Furthermore, we assessed the quantitative and qualitative colonization of HA02 in cotton seedlings. Our study provides basic information to further explore managing strategies to control this critical disease. © 2012 The Authors Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

Nocardiopsis arabia sp. nov., a halotolerant actinomycete isolated from a sand-dune soil.

PubMed

Hozzein, Wael N; Goodfellow, Michael

2008-11-01

The taxonomic status of an unknown actinomycete isolated from a sand-dune soil was established using a polyphasic approach. Isolate S186(T) had chemotaxonomic and morphological properties consistent with its classification in the genus Nocardiopsis, grew on agar plates at NaCl concentrations of up to 15 % (w/v) and formed a distinct phyletic line in the Nocardiopsis 16S rRNA gene sequence tree. Its closest phylogenetic neighbours were Nocardiopsis chromatogenes, Nocardiopsis composta, Nocardiopsis gilva and Nocardiopsis trehalosi, with sequence similarity to the various type strains of 96.9 %, but it was readily distinguished from the type strains of these and related species using a range of phenotypic properties. It is apparent from the genotypic and phenotypic data that strain S186(T) belongs to a novel species of the genus Nocardiopsis, for which the name Nocardiopsis arabia sp. nov. is proposed. The type strain is S186(T) (=CGMCC 4.2057(T) =DSM 45083(T)).

Diversity of fungal endophytes in non-native Phragmites australis in the Great Lakes

USGS Publications Warehouse

Clay, Keith; Shearin, Zachery; Bourke, Kimberly; Bickford, Wesley A.; Kowalski, Kurt P.

2016-01-01

Plant–microbial interactions may play a key role in plant invasions. One common microbial interaction takes place between plants and fungal endophytes when fungi asymptomatically colonize host plant tissues. The objectives of this study were to isolate and sequence fungal endophytes colonizing non-native Phragmites australis in the Great Lakes region to evaluate variation in endophyte community composition among three host tissue types and three geographical regions. We collected entire ramets from multiple clones and populations, surface sterilized plant tissues, and plated replicate tissue samples from leaves, stems, and rhizomes on corn meal agar plates to culture and isolate fungal endophytes. Isolates were then subjected to Sanger sequencing of the ITS region of the nuclear ribosomal DNA. Sequences were compared to fungal databases to define operational taxonomic units (OTUs) that were analyzed statistically for community composition. In total, we obtained 173 endophyte isolates corresponding to 55 OTUs, 39 of which were isolated only a single time. The most common OTU corresponded most closely to Sarocladium strictum and comprised 25 % of all fungal isolates. More OTUs were found in stem tissues, but endophyte diversity was greatest in rhizome tissues. PERMANOVA analyses indicated significant differences in endophyte communities among tissue types, geographical regions, and the interaction between those factors, but no differences among individual ramets were detected. The functional role of the isolated endophytes is not yet known, but one genus isolated here (Stagonospora) has been reported to enhance Phragmites growth. Understanding the diversity and functions of Phragmites endophytes may provide targets for control measures based on disrupting host plant/endophyte interactions.

Complete Genome Sequence of Micromonospora Strain L5, a Potential Plant-Growth-Regulating Actinomycete, Originally Isolated from Casuarina equisetifolia Root Nodules

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

Hirsch, A. M.; Alvarado, J.; Bruce, D.

2013-08-29

Micromonospora species live in diverse environments and exhibit a broad range of functions including antibiotic production, biocontrol, and ability to degrade complex polysaccharides. To learn more about these versatile actinomycetes, we sequenced the genome of strain L5, originally isolated from root nodules of an actinorhizal plant growing in Mexico.

[Diversity of endophytic fungi associated with Ferula sinkiangensis K. M. Shen].

PubMed

Sun, Li; Zhu, Jun; Li, Xiaojin; Shi, Shubing; Guo, Shunxing

2014-08-04

We studied the diversity of endophytic fungi associated with Ferula sinkiangensis K. M. Shen. Endophytic fungi from different years (1-2 years, 3-4 years and > 5 years) and different parts (root, stemand leaf) of Ferula sinkiangensis K. M. Shen were isolated by tissue expand method. Strains were classified by morphology and similarity of internal transcribed spacer (ITS) sequence by Clustal X method. Composition, diversity and preference of endophytic fungal community were analyzed by the isolation rate (IR), isolation frequency (IF), Shannon-Wiener biodiversity index (H'), Margalef Richness index (R). In total 140 endophytic fungi were isolated from F. sinkiangensis K. M. Shen and classified into 18 genera. Among the 140 isolates, Aureobasidium (25.7%), Alternaria (16.4%) and Phyllosticta (15.7%) were the dominant genera. The isolation results show that there were some notable differences between distribution and composition of the endophytic fungi isolated from different years and different parts of Ferula sinkiangensis K. M. Shen. Meanwhile, a certain degree of years and tissue preference were also obvious. The results obtained in this study will be helpful to exploit the endophytic fungal resources of Ferula sinkiangensis K. M. Shen, which can also provide a new way for the realization of the artificial breeding of Ferula sinkiangensis K. M. Shen.

Fungal endophytes characterization from four species of Diplazium Swartz

NASA Astrophysics Data System (ADS)

Affina-Eliya, A. A.; Noraini, T.; Nazlina, I.; Ruzi, A. R.

2014-09-01

Four species on genus Diplazium namely Diplazium tomentosum, D. sorzogonense, D. asperum and D. accedens of Peninsular Malaysia were studied for presence of fungal endophyte. The objective of this study is to characterize fungal endophytes in the rhizome of four Diplazium species. The rhizome was surface sterilized and incubated to isolate fungal endophytes. Characterization of the colonies was performed by macroscopic morphological, microscopic identification, types of hyphae and mycelium, and spore structure. For isolation that produces spores, the structure of conidiophores and conidia were identified. From this study, four fungal have been isolated and determined as Aspergillus sp. (isolates AE 1), Aspergillus fumigatus (isolates AE 2), Aspergillus versicolor (isolates AE 3) and Verticillium sp. (isolates AE 4). The fungal isolates from this study were classified from the same family Moniliaceae.

Actinomycetes: still a source of novel antibiotics.

PubMed

Genilloud, Olga

2017-10-18

Covering: 2006 to 2017Actinomycetes have been, for decades, one of the most important sources for the discovery of new antibiotics with an important number of drugs and analogs successfully introduced in the market and still used today in clinical practice. The intensive antibacterial discovery effort that generated the large number of highly potent broad-spectrum antibiotics, has seen a dramatic decline in the large pharma industry in the last two decades resulting in a lack of new classes of antibiotics with novel mechanisms of action reaching the clinic. Whereas the decline in the number of new chemical scaffolds and the rediscovery problem of old known molecules has become a hurdle for industrial natural products discovery programs, new actinomycetes compounds and leads have continued to be discovered and developed to the preclinical stages. Actinomycetes are still one of the most important sources of chemical diversity and a reservoir to mine for novel structures that is requiring the integration of diverse disciplines. These can range from novel strategies to isolate species previously not cultivated, innovative whole cell screening approaches and on-site analytical detection and dereplication tools for novel compounds, to in silico biosynthetic predictions from whole gene sequences and novel engineered heterologous expression, that have inspired the isolation of new NPs and shown their potential application in the discovery of novel antibiotics. This review will address the discovery of antibiotics from actinomycetes from two different perspectives including: (1) an update of the most important antibiotics that have only reached the clinical development in the recent years despite their early discovery, and (2) an overview of the most recent classes of antibiotics described from 2006 to 2017 in the framework of the different strategies employed to untap novel compounds previously overlooked with traditional approaches.

Glycomyces tarimensis sp. nov., an actinomycete isolated from a saline-alkali habitat.

PubMed

Lv, Ling-Ling; Zhang, Yue-Feng; Zhang, Li-Li

2015-05-01

A novel actinomycete strain, designated TRM 45387(T), was isolated from a saline-alkali soil in Xinjiang Province (40° 22' N 79° 08' E), north-west China. The isolate was characterized using a polyphasic approach. 16S rRNA gene sequence analysis indicated that strain TRM 45387(T) belonged to the genus Glycomyces and was closely related to Glycomyces arizonensis DSM 44726(T) (96.59% 16S rRNA gene sequence similarity). The G+C content of the DNA was 71.26 mol%. The isolate contained meso-diaminopimelic acid as the diagnostic diamino acid, and xylose, glucose, galactose, arabinose and ribose as the major whole-cell sugars. The diagnostic phospholipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositolmannosides. The predominant menaquinone was MK-10(H6). The major fatty acids were iso-C16 : 0, anteiso-C17 : 0 and anteiso-C15 : 0. On the basis of the evidence from this polyphasic study, a novel species, Glycomyces tarimensis sp. nov., is proposed. The type strain of Glycomyces tarimensis is TRM 45387(T) ( =CCTCC AA 2014007(T) =JCM 30184(T)). © 2015 Xinjiang Production & Construction Corps Key Laborartory of Protection and Utilization of Biological Resources in Tarim Basin.

Molecular and phenotypic characterization of endophytic bacteria isolated from sulla nodules.

PubMed

Beghalem, Hamida; Aliliche, Khadidja; Chriki, Ali; Landoulsi, Ahmed

2017-10-01

In the current study, bacterial diversity was investigated in root nodules of Sulla pallida and Sulla capitata. The isolates were analyzed on the basis of their phenotypic and molecular characteristics. The phylogenetic analysis based on 16S rRNA and housekeeping genes (recA and atpD) showed that the isolated bacteria related to Sinorhizobium, Neorhizobium, Phyllobacterium, Arthrobacter, Variovorax and Pseudomonas genera. This is the first report of Neorhizobium genus associated with Hedysarum genus. Phenotypically, all strains tolerate the elevated temperature of 40 °C, and salt stress at a concentration of 2%. In addition, the isolates failed to induce nodulation on their original host; and the symbiotic genes could not be amplified, suggesting that these strains are endophytic bacteria. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Isolation, idetification and anti-HIV-1 integrase activity of culturable endophytic fungi from Tibetan medicinal plant Phlomis younghusbandii Mukerjee].

PubMed

Zhang, Da-Wei; Zhao, Ming-Ming; Chen, Juan; Li, Chao; Guo, Shun-Xing

2013-05-01

A total of 52 endophytic fungi were isolated from roots and stems of Tibetan medicinal plant Phlomis younghusbandii Mukerjee. These fungal isolates were molecularly identified based on ITS sequnces and 28S sequences distributed to 12 genera, including Phoma, Chaetosphaeronema, Fusarium and Leptosphaeria, etc. Among them, the dominant genus was Phoma. Extracts of all strains were evaluated for anti-HIV-1 integrase activity by using soluable integrase expressed in E. coli BL21 (DE3). The results showed that seven samples from five fungal endophytes PHY-24, PHY-38, PHY-40, PHY-51, PHY-53, which belonged to genus Chaetosphaeronema, inhibited strand transfer reaction catalyzed by HIV-1 integrase with IC50 values, of 6.60, 5.20, 2.86, 7.86, 4.47, 4.56 and 3.23 microg x mL(-1) respectively. In conclusion, the endophytic fungi of Phlomis younghusbandii Mukerjee are valuable for further screening anti-HIV-1 integrase agents.

Studies on the Thermophilic Actinomycetes1

PubMed Central

Tendler, M. D.; Burkholder, P. R.

1961-01-01

A total of 1,000 isolates of thermophilic actinomycetes representing two genera, Streptomyces and Thermoactinomyces, were studied. Media for cultivation and for physiological studies were designed. Differences between the two genera are noted and taxonomic criteria for the genus Thermoactinomyces are suggested. The importance of the nutritional environment to the thermophilic habit is noted. PMID:13775873

Isolation and Characterization of an Endophytic Fungal Strain with Potent Antimicrobial and Termiticidal Activities From Port-Orford-Cedar.

PubMed

Sun, Liqing; Hse, Chung-Yun; Shupe, Todd; Sun, Mingjing; Wang, Xiaohua; Zhao, Kai

2015-06-01

Termites are responsible for an estimated US$1 billion annually in property damage, repairs, pest control, and prevention. There is an urgent need of finding a better alternative way to control and prevent termites. Port-Orford-Cedar (POC) has been known to have significant levels of natural durability and termiticidal activities due to its extractive contents. In this study, 25 endophytes including 22 fungal and 3 bacterial strains were isolated from the POC. Four strains, namely, HDZK-BYF21, HDZK-BYF1, HDZK-BYF2, and HDZK-BYB11, were chosen to test their termiticidal activities. The fermentation broth of strain HDZK-BYF21 displayed the potent antimicrobial and termiticidal activities. Morphological examination and 18 S rDNA sequence analysis demonstrated that strain HDZK-BYF21 belonged to the genus Aspergillus. This finding indicates the existence of an interesting chemical symbiosis between an endophytic fungus and its host. This is also the first report on endophytes isolated from the POC that may have potential termiticidal activities. Endophytes with termiticidal activities can be grown in bioreactor to provide an inexhaustible supply of bioactive compounds and thus can be exploited commercially. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Diversity of endophytic fungi in Glycine max.

PubMed

Fernandes, Elio Gomes; Pereira, Olinto Liparini; da Silva, Cynthia Cânedo; Bento, Claudia Braga Pereira; de Queiroz, Marisa Vieira

2015-12-01

Endophytic fungi are microorganisms that live within plant tissues without causing disease during part of their life cycle. With the isolation and identification of these fungi, new species are being discovered, and ecological relationships with their hosts have also been studied. In Glycine max, limited studies have investigated the isolation and distribution of endophytic fungi throughout leaves and roots. The distribution of these fungi in various plant organs differs in diversity and abundance, even when analyzed using molecular techniques that can evaluate fungal communities in different parts of the plants, such as denaturing gradient gel electrophoresis (DGGE). Our results show there is greater species richness of culturable endophytic filamentous fungi in the leaves G. max as compared to roots. Additionally, the leaves had high values for diversity indices, i.e. Simpsons, Shannon and Equitability. Conversely, dominance index was higher in roots as compared to leaves. The fungi Ampelomyces sp., Cladosporium cladosporioides, Colletotrichum gloeosporioides, Diaporthe helianthi, Guignardia mangiferae and Phoma sp. were more frequently isolated from the leaves, whereas the fungi Fusarium oxysporum, Fusarium solani and Fusarium sp. were prevalent in the roots. However, by evaluating the two communities by DGGE, we concluded that the species richness was higher in the roots than in the leaves. UPGMA analysis showed consistent clustering of isolates; however, the fungus Leptospora rubella, which belongs to the order Dothideales, was grouped among species of the order Pleosporales. The presence of endophytic Fusarium species in G. max roots is unsurprising, since Fusarium spp. isolates have been previously described as endophyte in other reports. However, it remains to be determined whether the G. max Fusarium endophytes are latent pathogens or non-pathogenic forms that benefit the plant. This study provides a broader knowledge of the distribution of the fungal

Endophytic Ability of Different Isolates of Entomopathogenic Fungi Beauveria bassiana (Balsamo) Vuillemin in Stem and Leaf Tissues of Maize (Zea mays L.).

PubMed

Renuka, S; Ramanujam, B; Poornesha, B

2016-06-01

The present study was conducted to examine the ability of six promising indigenous isolates of Beauveria bassiana (NBAII-Bb-5a, 7, 14, 19, 23 and 45) as an endophyte in maize stem and leaf tissues. Maize seedlings (var. Nithyashree) were inoculated with conidial suspensions and were examined for endophytic establishment in leaf and stems at different intervals during 15-90 days after treatment. All six isolates showed colonization in stem and leaf tissues with varying abilities of colonization and persistence. The mean percent colonization ranged from 7.41 to 20.37 % in older stem tissues and 3.70 to 21.29 % in young stem tissues and in leaf, it ranged from 6.46 to 27.78 % in older leaf tissues and 11.11 to 26.85 % in young leaf tissues. Among six isolates tested, Bb-23 isolate recorded the maximum mean colonization in older stem (20.37 %), older leaf (27.78 %) and in young stem (21.29 %). Bb-5a isolate showed maximum mean colonization in young leaf tissues (26.85 %). Persistence of inoculated fungal isolates decreased with increase in age of the plant. No physical symptoms of damage were observed in any of the B. bassiana treated plants. No colonization of B. bassiana was observed in the untreated control maize plants. The results obtained in plating and PCR techniques were similar with regard to the confirmation of endophytic establishment of B. bassiana. This study indicated the possibility of using B. bassiana as an endophyte in maize for management of maize stem borer, Chilo partellus.

Actinomycetes of Orthosipon stamineus rhizosphere as producer of antibacterial compound against multidrug resistant bacteria

NASA Astrophysics Data System (ADS)

Rante, H.; Yulianty, R.; Usmar; Djide, N.; Subehan; Burhamzah, R.; Prasad, M. B.

2017-11-01

The increasing case of antibiotic resistence has become an important problem to be faced in treating the infection diseases. The diversities of microbia, especially actinomycetes bacteria which originated from rizosphere soil of medicinal plant, has opened a chance for discovering the metabolites which can be used in solving the antibiotic resistant pathogenic bacteria problems. The aim of this research was to isolate the actinobacteria originated from medicinal plant rizosphere of Orthosipon stamineus as the producer of anti-multidrug resistances bacteria compounds. Three isolates of actinomycetes has been isolated from Orthosipon stamineus rhizosphere named KC3-1, KC3-2 and KC3-3. One isolate (KC3-3) showed big activity in inhibiting the test microbes by antagonistic test of actinomycetes isolates against Staphylococcus aureus and Eschericia coli antibiotic resistant bacteria. Furthermore, the KC3-3 isolate was fermented in Starch Nitrate Broth (SNB) medium for 14 days. The supernatant and the biomass of the fermentation yield were separated. The supernatant were extracted using ethyl acetate as the solvent and the biomass were extracted using methanol. The antibacterial activity test of ethyl acetate and methanol extract revealed that the extracts can inhibit the bacteria test up to 5% concentration. The ethyl acetate and methanol extracts can inhibit the bacteria test up to 5% concentration.

Endophytic Trichoderma isolates from tropical environments delay disease onset and induce resistance against Phytophthora capsici in hot pepper using multiple mechanisms

USDA-ARS?s Scientific Manuscript database

Isolates of several Trichoderma spp., were collected from tropical environments as potential biocontrol agents for cacao (Theobroma cacao) diseases. The diversity of isolates collected, including new species, and there endophytic nature on their host plants, led us to consider if these isolates have...

Antibacterial Activities of Endophytic Bacteria Isolated from Taxus brevifolia Against Foodborne Pathogenic Bacteria.

PubMed

Islam, Nurul; Choi, Jaehyuk; Baek, Kwang-Hyun

2018-05-01

Endophytes are a potential source of novel bioactive compounds with medicinal properties. In this study, 41 endophytic bacteria (EB) were isolated from tissues of a medicinally important plant Taxus brevifolia (Pacific yew). The objective was to screen all the EB isolates for their antibacterial effects against five foodborne pathogenic bacteria: Bacillus cereus ATCC10876, Staphylococcus aureus ATCC12600, Listeria monocytogenes ATCC19115, Escherichia coli ATCC43890, and Salmonella Typhimurium ATCC19585. Among the EB isolates, T. brevifolia seed (TbS)-8, T. brevifolia fleshy part of fruit (TbFl)-10, T. brevifolia leaf (TbL)-22, TbS-29, and TbL-34 exerted significant antibacterial activity against the tested foodborne pathogens. Especially TbFl-10 showed the highest antibacterial activity against all the tested bacteria and was identified as Paenibacillus kribbensis (Pk). Furthermore, an ethyl acetate extract of Pk-TbFl-10 possessed antibacterial activities against the tested five foodborne pathogenic bacteria, with zones of inhibition from 15.71 ± 2.85 to 13.01 ± 2.12 mm. Scanning electron microscopy analysis revealed ruptured, lysed, shrunk, and swollen cells of all the tested foodborne pathogens treated with the ethyl acetate extract of Pk-TbFl-10, suggesting that a metabolite(s) of Pk-TbFl-10 penetrates the cell membrane and causes cell lysis leading to cell death. Our results indicate that Pk-TbFl-10 isolated from T. brevifolia can serve as a novel source of natural antibacterial agents against foodborne pathogenic bacteria, with potential applications in the pharmaceutical industry.

Field studies on two rock phosphate solubilizing actinomycete isolates as biofertilizer sources

NASA Astrophysics Data System (ADS)

Mba, Caroline C.

1994-03-01

Recently biotechnology is focusing attention on utilization of biological resources to solve a number of environmental problems such as soil fertility management. Results of microbial studies on earthworm compost in the University of Nigeria farm identified a number of rock phosphate solubilizing actinomycetes. Two of these, isclates 02 and 13, were found to be efficient rock phosphate (RP) solubilizers and fast-growing cellulolytic microbes producing extracellular hydrolase enzymes. In this preliminary field study the two microbial isolates were investigated with respect to their effects on the growth of soybean and egusi as well as their effect on the incidence of toxicity of poultry droppings. Application of these isolates in poultry manure-treated field plots, as microbial fertilizers, brought about yield increases of 43% and 17% with soybeans and 19% and 33% with egusi, respectively. Soil properties were also improved. With isolates 02 and 13, the soil available phosphorus increased at the five-leaf stage, while N-fixation in the soil increased by 45% or 11% relative to control. It was further observed that air-dried poultry manure after four days of incubation was still toxic to soybean. The toxic effect of the applied poultry manure was reduced or eliminated with microbial fertilizers 02 or 13, respectively. The beneficial effects of the microbial organic fertilizer are discussed. Justification for more intensive research on rock phosphate organic fertilizer is highlighted.

Biodiversity, Phylogeny, and Antifungal Functions of Endophytic Fungi Associated with Zanthoxylum bungeanum.

PubMed

Li, Peiqin; Wu, Zhou; Liu, Tao; Wang, Yanan

2016-09-13

This study investigated the biodiversity, phylogeny, and antifungal activity of endophytic fungi isolated from Zanthoxylum bungeanum. A total of 940 isolates obtained were grouped into 93 morphotypes, 43 species, and 23 genera, which were authenticated by molecular identification based on rDNA internal transcribed spacer (ITS) sequence analysis. A high diversity of endophytic fungi from Z. bungeanum are observed with high species richness S (43), Margalef index D' (6.1351), Shannon-Wiener index H' (3.2743), Simpson diversity index Ds (0.9476), PIE index (0.9486), and evenness Pielou index J (0.8705) but a low dominant index λ (0.0524). Significant tissue specificity of the endophytic fungi was observed in Z. bungeanum, and the highest species richness and diversity indexes were obtained in the stem. Phylogenetic analyses of the 93 endophytic isolates were carried out by the neighbor-joining (NJ) method to demonstrate their evolutionary processes. Antifungal activities of endophytic fungi were assayed and eight endophytic isolates showed strong and long-lasting inhibition against host pathogenic fungi Fusarium sambucinum and Pseudocercospora zanthoxyli. Here, for the first time, we systematically demonstrate the biodiversity, phylogeny, and antifungal activity of endophytic fungi associated with Z. bungeanum and reveal the value of sampling different tissues of a given plant to obtain the greatest endophyte species diversity, which might offer a framework for further investigation and utilization of endophytic fungi as aunique source of interesting and useful bioactive compounds.

Biodiversity, Phylogeny, and Antifungal Functions of Endophytic Fungi Associated with Zanthoxylum bungeanum

PubMed Central

Li, Peiqin; Wu, Zhou; Liu, Tao; Wang, Yanan

2016-01-01

This study investigated the biodiversity, phylogeny, and antifungal activity of endophytic fungi isolated from Zanthoxylum bungeanum. A total of 940 isolates obtained were grouped into 93 morphotypes, 43 species, and 23 genera, which were authenticated by molecular identification based on rDNA internal transcribed spacer (ITS) sequence analysis. A high diversity of endophytic fungi from Z. bungeanum are observed with high species richness S (43), Margalef index D′ (6.1351), Shannon–Wiener index H′ (3.2743), Simpson diversity index Ds (0.9476), PIE index (0.9486), and evenness Pielou index J (0.8705) but a low dominant index λ (0.0524). Significant tissue specificity of the endophytic fungi was observed in Z. bungeanum, and the highest species richness and diversity indexes were obtained in the stem. Phylogenetic analyses of the 93 endophytic isolates were carried out by the neighbor-joining (NJ) method to demonstrate their evolutionary processes. Antifungal activities of endophytic fungi were assayed and eight endophytic isolates showed strong and long-lasting inhibition against host pathogenic fungi Fusarium sambucinum and Pseudocercospora zanthoxyli. Here, for the first time, we systematically demonstrate the biodiversity, phylogeny, and antifungal activity of endophytic fungi associated with Z. bungeanum and reveal the value of sampling different tissues of a given plant to obtain the greatest endophyte species diversity, which might offer a framework for further investigation and utilization of endophytic fungi as aunique source of interesting and useful bioactive compounds. PMID:27649145

Studies on the factors modulating indole-3-acetic acid production in endophytic bacterial isolates from Piper nigrum and molecular analysis of ipdc gene.

PubMed

Jasim, B; Jimtha John, C; Shimil, V; Jyothis, M; Radhakrishnan, E K

2014-09-01

The study mainly aimed quantitative analysis of IAA produced by endophytic bacteria under various conditions including the presence of extract from Piper nigrum. Analysis of genetic basis of IAA production was also conducted by studying the presence and diversity of the ipdc gene among the selected isolates. Five endophytic bacteria isolated previously from P. nigrum were used for the study. The effect of temperature, pH, agitation, tryptophan concentration and plant extract on modulating IAA production of selected isolates was analysed by colorimetric method. Comparative and quantitative analysis of IAA production by colorimetric isolates under optimal culture condition was analysed by HPTLC method. Presence of ipdc gene and thereby biosynthetic basis of IAA production among the selected isolates were studied by PCR-based amplification and subsequent insilico analysis of sequence obtained. Among the selected bacterial isolates from P. nigrum, isolate PnB 8 (Klebsiella pneumoniae) was found to have the maximum yield of IAA under various conditions optimized and was confirmed by colorimetric, HPLC and HPTLC analysis. Very interestingly, the study showed stimulating effect of phytochemicals from P. nigrum on IAA production by endophytic bacteria isolated from same plant. This study is unique because of the selection of endophytes from same source for comparative and quantitative analysis of IAA production under various conditions. Study on stimulatory effect of phytochemicals on bacterial IAA production as explained in the study is a novel approach. Studies on molecular basis of IAA production which was confirmed by sequence analysis of ipdc gene make the study scientifically attractive. Even though microbial production of IAA is well known, current report on detailed optimization, effect of plant extract and molecular confirmation of IAA biosynthesis is comparatively novel in its approach. © 2014 The Society for Applied Microbiology.

Endophytic Fungal Flora from Roots and Fruits of an Indian Neem Plant Azadirachta indica A. Juss., and Impact of Culture Media on their Isolation.

PubMed

Verma, Vijay C; Gond, Surendra K; Kumar, Anuj; Kharwar, Ravindra N; Boulanger, Lori-Ann; Strobel, Gary A

2011-10-01

Azadirachta indica A. Juss. (neem), native to India, is well known worldwide for its insecticidal and ethanopharmacological properties. Although endophytic microbes are known from this plant as only leaves and stems were the subjects of past reports. Now, a variety of procedures and a number of different media were used to isolate the maximum number of endophytic fungi from unripe fruits and roots. A total of 272 isolates of 29 filamentous fungal taxa were isolated at rate of 68.0% from 400 samples of three different individual trees (at locations-Az1, Az2, Az3). Mycological agar (MCA) medium yielded the highest number of isolates (95, with a 14.50% isolation rate) with the greatest species richness. Mycelia Sterilia (1, 2, 3) accounted for 11.06%, Coelomycetes 7.25%, while Hyphomycetes showed the maximum number of representative isolates (81.69%). Mycelia-Sterilia (1, 2, 3), based on their 5.8S ITS 1, ITS2 and partial 18S and 28S rDNA sequences were identified as Fusarium solani (99%), Chaetomium globosum (93%) and Chaetomium globosum (93%) respectively. Humicola, Drechslera, Colletotrichum, and Scytalidium sp. were some of the peculiar fungal endophytes recovered from this plant.

A primary assessment of the endophytic bacterial community in a xerophilous moss (Grimmia montana) using molecular method and cultivated isolates

PubMed Central

Liu, Xiao Lei; Liu, Su Lin; Liu, Min; Kong, Bi He; Liu, Lei; Li, Yan Hong

2014-01-01

Investigating the endophytic bacterial community in special moss species is fundamental to understanding the microbial-plant interactions and discovering the bacteria with stresses tolerance. Thus, the community structure of endophytic bacteria in the xerophilous moss Grimmia montana were estimated using a 16S rDNA library and traditional cultivation methods. In total, 212 sequences derived from the 16S rDNA library were used to assess the bacterial diversity. Sequence alignment showed that the endophytes were assigned to 54 genera in 4 phyla (Proteobacteria, Firmicutes, Actinobacteria and Cytophaga/Flexibacter/Bacteroids). Of them, the dominant phyla were Proteobacteria (45.9%) and Firmicutes (27.6%), the most abundant genera included Acinetobacter, Aeromonas, Enterobacter, Leclercia, Microvirga, Pseudomonas, Rhizobium, Planococcus, Paenisporosarcina and Planomicrobium. In addition, a total of 14 species belonging to 8 genera in 3 phyla (Proteobacteria, Firmicutes, Actinobacteria) were isolated, Curtobacterium, Massilia, Pseudomonas and Sphingomonas were the dominant genera. Although some of the genera isolated were inconsistent with those detected by molecular method, both of two methods proved that many different endophytic bacteria coexist in G. montana. According to the potential functional analyses of these bacteria, some species are known to have possible beneficial effects on hosts, but whether this is the case in G. montana needs to be confirmed. PMID:24948927

Broad-spectrum inhibition of Phytophthora infestans by fungal endophytes

PubMed Central

von Dahlen, Janina K; Schnake, Anika; Ginschel, Sarah; Schulz, Barbara; Rose, Laura E

2018-01-01

ABSTRACT Phytophthora infestans is a devastating pathogen of tomato and potato. It readily overcomes resistance genes and applied agrochemicals and hence even today causes large yield losses. Fungal endophytes provide a largely unexplored avenue of control of Phy. infestans. Not only do endophytes produce a wide array of bioactive metabolites, they may also directly compete with and defeat pathogens in planta. Here, we tested 12 fungal endophytes isolated from different plant species in vitro for their production of metabolites with anti- Phytophthora activity. Four well-performing isolates were evaluated for their ability to suppress nine isolates of Phy. infestans on agar medium and in planta. Two endophytes reliably inhibited all Phy. infestans isolates on agar medium, of which Phoma eupatorii isolate 8082 was the most promising. It nearly abolished infection by Phy. infestans in planta. Our data indicate a role for the production of anti-Phytophthora compounds by the fungus and/or an enhanced plant defense response, as evident by an enhanced anthocyanin production. Here, we present a potential biocontrol agent, which can inhibit a broad-spectrum of Phy. infestans isolates. Such broadly acting inhibition is ideal, because it allows for effective control of genetically diverse isolates and may slow the adaptation of Phy. infestans. PMID:29528408

Streptomyces gamaensis sp. nov., a novel actinomycete with antifungal activity isolated from soil in Gama, Chad.

PubMed

Zhao, Shanshan; Ye, Lan; Liu, Chongxi; Abagana, Adam Yacoub; Zheng, Weiwei; Sun, Pengyu; Li, Jiansong; Xiang, Wensheng; Wang, Xiangjing

2017-04-01

During an investigation exploring potential sources of novel species and natural products, a novel actinomycete with antifungal activity, designated strain NEAU-Gz11 T , was isolated from a soil sample, which was collected from Gama, Chad. The isolate was found to have morphological and chemotaxonomic characteristics typical of members of the genus Streptomyces. 16S rRNA gene sequence similarity studies showed that strain NEAU-Gz11 T belongs to the genus Streptomyces with high sequence similarity to Streptomyces hiroshimensis JCM 4098 T (98.0 %). Similarities to other type strains of the genus Streptomyces were lower than 98.0 %. However, the physiological and biochemical characteristics and low levels of DNA-DNA relatedness could differentiate the isolate genotypically and phenotypically from S. hiroshimensis JCM 4098 T . Therefore, the strain is concluded to represent a novel species of the genus Streptomyces, for which the name Streptomyces gamaensis sp. nov. is proposed. The type strain is NEAU-Gz11 T (=CGMCC 4.7304 T =DSM 101531 T ).

Bioactive endophytes warrant intensified exploration and conservation.

PubMed

Smith, Stephen A; Tank, David C; Boulanger, Lori-Ann; Bascom-Slack, Carol A; Eisenman, Kaury; Kingery, David; Babbs, Beatrice; Fenn, Kathleen; Greene, Joshua S; Hann, Bradley D; Keehner, Jocelyn; Kelley-Swift, Elizabeth G; Kembaiyan, Vivek; Lee, Sun Jin; Li, Puyao; Light, David Y; Lin, Emily H; Ma, Cong; Moore, Emily; Schorn, Michelle A; Vekhter, Daniel; Nunez, Percy V; Strobel, Gary A; Donoghue, Michael J; Strobel, Scott A

2008-08-25

A key argument in favor of conserving biodiversity is that as yet undiscovered biodiversity will yield products of great use to humans. However, the link between undiscovered biodiversity and useful products is largely conjectural. Here we provide direct evidence from bioassays of endophytes isolated from tropical plants and bioinformatic analyses that novel biology will indeed yield novel chemistry of potential value. We isolated and cultured 135 endophytic fungi and bacteria from plants collected in Peru. nrDNAs were compared to samples deposited in GenBank to ascertain the genetic novelty of cultured specimens. Ten endophytes were found to be as much as 15-30% different than any sequence in GenBank. Phylogenetic trees, using the most similar sequences in GenBank, were constructed for each endophyte to measure phylogenetic distance. Assays were also conducted on each cultured endophyte to record bioactivity, of which 65 were found to be bioactive. The novelty of our contribution is that we have combined bioinformatic analyses that document the diversity found in environmental samples with culturing and bioassays. These results highlight the hidden hyperdiversity of endophytic fungi and the urgent need to explore and conserve hidden microbial diversity. This study also showcases how undergraduate students can obtain data of great scientific significance.

Molecular profiling and bioactive potential of an endophytic fungus Aspergillus sulphureus isolated from Sida acuta: a medicinal plant.

PubMed

Murali, M; Mahendra, C; Hema, P; Rajashekar, N; Nataraju, A; Sudarshana, M S; Amruthesh, K N

2017-12-01

Sida acuta Burm.f. (Malvaceae) extracts are reported to have applications against malaria, diuretic, antipyretic, nervous and urinary diseases. No fungal endophytes of S. acuta are reported. Isolation, identification and evaluation of antibacterial, antioxidant, anticancer and haemolytic potential of fungal endophytes from the ethnomedcinal plant S. acuta. Sida acuta stem segments were placed on PDA medium to isolate endophytic fungi. The fungus was identified by genomic DNA analysis and phylogenetic tree was constructed using ITS sequences (GenBank) to confirm species. The antibacterial efficacy of Aspergillus sulphureus MME12 ethyl acetate extract was tested against Gram-positive and Gram-negative pathogenic bacteria. DPPH free radical scavenging activity, anticancer and DNA fragmentation against EAC cells, and direct haemolytic activity (100-500 μg/mL) using human erythrocytes were determined. The ethyl acetate extract of A. sulphureus (Fresen.) Wehmer (Trichocomaceae) demonstrated significant antibacterial potential against Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Salmonella typhi compared to streptomycin. MIC against test pathogens was in the range of 15.6-62.5 μg/mL. The antioxidant results revealed significant RSA from 12.43% to 62.02% (IC 50  = 350.4 μg/mL, p ≤ 0.05). MME12 offered considerable inhibition of EAC proliferation (23% to 84%, IC 50  = 216.7 μg/mL, p ≤ 0.05) supported by DNA fragmentation studies. The extract also offered insignificant haemolysis (5.6%) compared to Triton X-100. A single endophytic fungus, A. sulphureus MME12 was isolated and identified using molecular profiling. The above-mentioned findings support the pharmacological application of A. sulphureus MME12 extract and demand for purification of the active principle(s).

Endophytic Fusarium spp. from Roots of Lawn Grass (Axonopus compressus)

PubMed Central

Zakaria, Latiffah; Ning, Chua Harn

2013-01-01

Fungal endophytes are found inside host plants but do not produce any noticeable disease symptoms in their host. In the present study, endophytic Fusarium species were isolated from roots of lawn grass (Axonopus compressus). A total of 51 isolates were recovered from 100 root segments. Two Fusarium species, F. oxysporum (53%) and F. solani (47%), were identified based on macroconidia and conidiogenous cell morphology. The detection of endophytic F. oxysporum and F. solani in the roots of lawn grass contributes to the knowledge of both the distribution of the two Fusarium species and the importance of roots as endophytic niches for Fusarium species. PMID:24575251

A Comparative biochemical study on two marine endophytes, Bacterium SRCnm and Bacillus sp. JS, Isolated from red sea algae.

PubMed

Ahmed, Eman Fadl; Hassan, Hossam Mokhtar; Rateb, Mostafa Ezzat; Abdel-Wahab, Noha; Sameer, Somayah; Aly Taie, Hanan Anwar; Abdel-Hameed, Mohammed Sayed; Hammouda, Ola

2016-01-01

Two marine endophytic bacteria were isolated from the Red Sea algae; a red alga; Acanthophora dendroides and the brown alga Sargassum sabrepandum. The isolates were identified based on their 16SrRNA sequences as Bacterium SRCnm and Bacillus sp. JS. The objective of this study was to investigate the potential anti-microbial and antioxidant activities of the extracts of the isolated bacteria grown in different nutrient conditions. Compared to amoxicillin (25μg/disk) and erythromycin (15μg/disk), the extracts of Bacterium SRCn min media II, III, IV and V were potent inhibitors of the gram-positive bacterium Sarcina maxima even at low concentrations. Also, the multidrug resistant Staphylococcus aureus(MRSA) was more sensitive to the metabolites produced in medium (II) of the same endophyte than erythromycin (15μg/disk). A moderate activity of the Bacillus sp. JS extracts of media I and II was obtained against the same pathogen. The total compounds (500ug/ml) of both isolated endophytes showed moderate antioxidant activities (48.9% and 46.1%, respectively). LC/MS analysis of the bacterial extracts was carried out to investigate the likely natural products produced. Cyclo(D-cis-Hyp-L-Leu), dihydrosphingosine and 2-Amino-1,3-hexadecanediol were identified in the fermentation medium of Bacterium SRCnm, whereas cyclo (D-Pro-L-Tyr) and cyclo (L-Leu-L-Pro) were the suggested compounds of Bacillus sp. JS.

Diversity and antimicrobial activity of endophytic fungi associated with the alpine plant Saussurea involucrata.

PubMed

Lv, Ya-li; Zhang, Fu-sheng; Chen, Juan; Cui, Jin-long; Xing, Yong-mei; Li, Xiang-dong; Guo, Shun-xing

2010-01-01

Endophytic fungi are rich in species diversity and may play an important role in the fitness of their host plants. This study investigated the diversity and antimicrobial potential of endophytic fungi obtained from Saussurea involucrata KAR. et KIR. A total of 49 endophytic fungi were isolated from S. involucrata and identified using morphological and molecular techniques. Extracts of fermentation broth from the 49 fungi were tested for antimicrobial activity against pathogenic microorganisms using the agar diffusion method. Forty-eight out of the 49 endophytic fungi were identified and grouped into 14 taxa. Cylindrocarpon sp. was the dominant species isolated from S. involucrata, followed by Phoma sp. and Fusarium sp. Among the 49 endophytic fungi, 9 root isolates having darkly pigmented, septate hyphae were identified as dark septate endophytic (DSE) fungus, and 12 fungi inhibited at least one test microorganism. Moreover, 5 strains showed a broader spectrum of antimicrobial activity and 4 strains displayed strong inhibition (+++) against pathogenic fungi. The results indicate that endophytic fungi isolated from S. involucrata are diverse in species and a potential source of antimicrobial agents.

Endophytic fungus strain 28 isolated from Houttuynia cordata possesses wide-spectrum antifungal activity.

PubMed

Pan, Feng; Liu, Zheng-Qiong; Chen, Que; Xu, Ying-Wen; Hou, Kai; Wu, Wei

2016-01-01

The aim of this paper is to identify and investigate an endophytic fungus (strain 28) that was isolated from Houttuynia cordata Thunb, a famous and widely-used Traditional Chinese Medicine. Based on morphological methods and a phylogenetic analysis of ITS sequences, this strain was identified as Chaetomium globosum. An antifungal activity bioassay demonstrated that the crude ethyl acetate (EtOAc) extracts of strain 28 had a wide antifungal spectrum and strong antimicrobial activity, particularly against Exserohilum turcicum (Pass.) Leonard et Suggs, Botrytis cinerea persoon and Botrytis cinerea Pers. ex Fr. Furthermore, the fermentation conditions, extraction method and the heat stability of antifungal substances from strain 28 were also studied. The results showed that optimal antifungal activity can be obtained with the following parameters: using potato dextrose broth (PDB) as the base culture medium, fermentation for 4-8d (initial pH: 7.5), followed by extraction with EtOAc. The extract was stable at temperatures up to 80°C. This is the first report on the isolation of endophytic C. globosum from H. cordata to identify potential alternative biocontrol agents that could provide new opportunities for practical applications involving H. cordata. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Population densities and genetic diversity of actinomycetes associated to the rhizosphere of Theobroma cacao

PubMed Central

Barreto, Tâmara R.; da Silva, Augusto C.M.; Soares, Ana Cristina F.; de Souza, Jorge T.

2008-01-01

In spite of the acknowledged importance of growth-promoting bacteria, only a reduced number of studies were conducted with these microorganisms on Theobroma cacao. The objectives of this work were to study the population densities and genetic diversity of actinomycetes associated with the rhizosphere of cacao as a first step in their application in plant growth promotion and biological control. The populations densities of actinomycetes in soil and cacao roots were similar, with mean values of 1,0 x 106 CFU/g and 9,6 x 105 CFU/g, respectively. All isolates selected and used in this study were identified through sequencing analyses of a fragment of the rpoB gene that encodes the β-subunit of the RNA polymerase as species of the genus Streptomyces. In vitro cellulolytic, xilanolytic and chitinolytic activity, indolacetic acid production and phosphate solubilization activities were observed in most of the isolates tested. The data obtained in this study demonstrate that actinomycetes account for a higher percentage of the total population of culturable bacteria in soil than on cacao roots. Additionally, actinomycetes from the cacao rhizosphere are genetically diverse and have potential applications as agents of growth promotion. PMID:24031247

Variation in endophytic fungi from roots and leaves of Lepanthes (Orchidaceae)

Treesearch

PAUL BAYMAN; LIGIA L. LEBRO; RAYMOND L. TREMBLAY; JEAN D. LODGE

1997-01-01

Little is known about non-mycorrhizal endophytic fungi in tropical orchids; still less is known about how endophytes vary within and between individual orchid plants. Fungal endophytes were isolated from roots and leaves of epiphytic and lithophytic orchids in the genus Lepanthes; seven species, from rainforests in Puerto Rico, were sampled. The endophytes observed...

Comparative Transcriptomics of Bacillus mycoides Strains in Response to Potato-Root Exudates Reveals Different Genetic Adaptation of Endophytic and Soil Isolates.

PubMed

Yi, Yanglei; de Jong, Anne; Frenzel, Elrike; Kuipers, Oscar P

2017-01-01

Plant root secreted compounds alter the gene expression of associated microorganisms by acting as signal molecules that either stimulate or repel the interaction with beneficial or harmful species, respectively. However, it is still unclear whether two distinct groups of beneficial bacteria, non-plant-associated (soil) strains and plant-associated (endophytic) strains, respond uniformly or variably to the exposure with root exudates. Therefore, Bacillus mycoides , a potential biocontrol agent and plant growth-promoting bacterium, was isolated from the endosphere of potatoes and from soil of the same geographical region. Confocal fluorescence microscopy of plants inoculated with GFP-tagged B. mycoides strains showed that the endosphere isolate EC18 had a stronger plant colonization ability and competed more successfully for the colonization sites than the soil isolate SB8. To dissect these phenotypic differences, the genomes of the two strains were sequenced and the transcriptome response to potato root exudates was compared. The global transcriptome profiles evidenced that the endophytic isolate responded more pronounced than the soil-derived isolate and a higher number of significant differentially expressed genes were detected. Both isolates responded with the alteration of expression of an overlapping set of genes, which had previously been reported to be involved in plant-microbe interactions; including organic substance metabolism, oxidative reduction, and transmembrane transport. Notably, several genes were specifically upregulated in the endosphere isolate EC18, while being oppositely downregulated in the soil isolate SB8. These genes mainly encoded membrane proteins, transcriptional regulators or were involved in amino acid metabolism and biosynthesis. By contrast, several genes upregulated in the soil isolate SB8 and downregulated in the endosphere isolate EC18 were related to sugar transport, which might coincide with the different nutrient availability

Two Endophytic Diaporthe Species Isolated from the Leaves of Astragalus membranaceus in Korea

PubMed Central

Kim, Jin-Hee; Kim, Dong-Yeo; Park, Hyeok

2017-01-01

We characterized two endophyte fungi from the leaves of Astragalus membranaceus in Korea. The isolated strains were identified on the basis of the morphological characters and sequences analysis of the internal transcribed spacer and large subunit regions of the rDNA and β-tubulin gene. To the best of our knowledge, this is the first report of Diaporthe oncostoma and Diaporthe infecunda in Korea, and we have provided descriptions and figures. PMID:29371813

Bacterial endophyte communities in the foliage of coast redwood and giant sequoia.

PubMed

Carrell, Alyssa A; Frank, Anna C

2015-01-01

The endophytic bacterial microbiome, with an emerging role in plant nutrient acquisition and stress tolerance, is much less studied in natural plant populations than in agricultural crops. In a previous study, we found consistent associations between trees in the pine family and acetic acid bacteria (AAB) occurring at high relative abundance inside their needles. Our objective here was to determine if that pattern may be general to conifers, or alternatively, is more likely restricted to pines or conifers growing in nutrient limited and exposed environments. We used 16S rRNA pyrosequencing to characterize the foliar endophyte communities of two conifers in the Cupressaceae family: Two coast redwood (CR; Sequoia sempervirens) populations and one giant sequoia (GS; Sequoiadendron giganteum) population were sampled. Similar to the pines, the endophyte communities of the giant trees were dominated by Proteobacteria, Firmicutes, Acidobacteria, and Actinobacteria. However, although some major operational taxonomic units (OTUs) occurred at a high relative abundance of 10-40% in multiple samples, no specific group of bacteria dominated the endophyte community to the extent previously observed in high-elevation pines. Several of the dominating bacterial groups in the CR and GS foliage (e.g., Bacillus, Burkholderia, Actinomycetes) are known for disease- and pest suppression, raising the possibility that the endophytic microbiome protects the giant trees against biotic stress. Many of the most common and abundant OTUs in our dataset were most similar to 16S rRNA sequences from bacteria found in lichens or arctic plants. For example, an OTU belonging to the uncultured Rhizobiales LAR1 lineage, which is commonly associated with lichens, was observed at high relative abundance in many of the CR samples. The taxa shared between the giant trees, arctic plants, and lichens may be part of a broadly defined endophyte microbiome common to temperate, boreal, and tundra ecosystems.

Bacterial endophyte communities in the foliage of coast redwood and giant sequoia

PubMed Central

Carrell, Alyssa A.; Frank, Anna C.

2015-01-01

The endophytic bacterial microbiome, with an emerging role in plant nutrient acquisition and stress tolerance, is much less studied in natural plant populations than in agricultural crops. In a previous study, we found consistent associations between trees in the pine family and acetic acid bacteria (AAB) occurring at high relative abundance inside their needles. Our objective here was to determine if that pattern may be general to conifers, or alternatively, is more likely restricted to pines or conifers growing in nutrient limited and exposed environments. We used 16S rRNA pyrosequencing to characterize the foliar endophyte communities of two conifers in the Cupressaceae family: Two coast redwood (CR; Sequoia sempervirens) populations and one giant sequoia (GS; Sequoiadendron giganteum) population were sampled. Similar to the pines, the endophyte communities of the giant trees were dominated by Proteobacteria, Firmicutes, Acidobacteria, and Actinobacteria. However, although some major operational taxonomic units (OTUs) occurred at a high relative abundance of 10–40% in multiple samples, no specific group of bacteria dominated the endophyte community to the extent previously observed in high-elevation pines. Several of the dominating bacterial groups in the CR and GS foliage (e.g., Bacillus, Burkholderia, Actinomycetes) are known for disease- and pest suppression, raising the possibility that the endophytic microbiome protects the giant trees against biotic stress. Many of the most common and abundant OTUs in our dataset were most similar to 16S rRNA sequences from bacteria found in lichens or arctic plants. For example, an OTU belonging to the uncultured Rhizobiales LAR1 lineage, which is commonly associated with lichens, was observed at high relative abundance in many of the CR samples. The taxa shared between the giant trees, arctic plants, and lichens may be part of a broadly defined endophyte microbiome common to temperate, boreal, and tundra ecosystems

Bacterial endophyte communities in the foliage of coast redwood and giant sequoia

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

Carrell, Alyssa A.; Frank, Anna C.

The endophytic bacterial microbiome, with an emerging role in plant nutrient acquisition and stress tolerance, is much less studied in natural plant populations than in agricultural crops. In a previous study, we found consistent associations between trees in the pine family and acetic acid bacteria (AAB) occurring at high relative abundance inside their needles. Our objective here was to determine if that pattern may be general to conifers, or alternatively, is more likely restricted to pines or conifers growing in nutrient limited and exposed environments. We used 16S rRNA pyrosequencing to characterize the foliar endophyte communities of two conifers inmore » the Cupressaceae family: Two coast redwood (CR; Sequoia sempervirens) populations and one giant sequoia (GS; Sequoiadendron giganteum) population were sampled. Similar to the pines, the endophyte communities of the giant trees were dominated by Proteobacteria, Firmicutes, Acidobacteria, and Actinobacteria. However, although some major operational taxonomic units (OTUs) occurred at a high relative abundance of 10–40% in multiple samples, no specific group of bacteria dominated the endophyte community to the extent previously observed in high-elevation pines. Several of the dominating bacterial groups in the CR and GS foliage (e.g., Bacillus, Burkholderia, Actinomycetes) are known for disease- and pest suppression, raising the possibility that the endophytic microbiome protects the giant trees against biotic stress. Many of the most common and abundant OTUs in our dataset were most similar to 16S rRNA sequences from bacteria found in lichens or arctic plants. For example, an OTU belonging to the uncultured Rhizobiales LAR1 lineage, which is commonly associated with lichens, was observed at high relative abundance in many of the CR samples. Lastly, the taxa shared between the giant trees, arctic plants, and lichens may be part of a broadly defined endophyte microbiome common to temperate, boreal, and

Bacterial endophyte communities in the foliage of coast redwood and giant sequoia

DOE PAGES

Carrell, Alyssa A.; Frank, Anna C.

2015-09-22

The endophytic bacterial microbiome, with an emerging role in plant nutrient acquisition and stress tolerance, is much less studied in natural plant populations than in agricultural crops. In a previous study, we found consistent associations between trees in the pine family and acetic acid bacteria (AAB) occurring at high relative abundance inside their needles. Our objective here was to determine if that pattern may be general to conifers, or alternatively, is more likely restricted to pines or conifers growing in nutrient limited and exposed environments. We used 16S rRNA pyrosequencing to characterize the foliar endophyte communities of two conifers inmore » the Cupressaceae family: Two coast redwood (CR; Sequoia sempervirens) populations and one giant sequoia (GS; Sequoiadendron giganteum) population were sampled. Similar to the pines, the endophyte communities of the giant trees were dominated by Proteobacteria, Firmicutes, Acidobacteria, and Actinobacteria. However, although some major operational taxonomic units (OTUs) occurred at a high relative abundance of 10–40% in multiple samples, no specific group of bacteria dominated the endophyte community to the extent previously observed in high-elevation pines. Several of the dominating bacterial groups in the CR and GS foliage (e.g., Bacillus, Burkholderia, Actinomycetes) are known for disease- and pest suppression, raising the possibility that the endophytic microbiome protects the giant trees against biotic stress. Many of the most common and abundant OTUs in our dataset were most similar to 16S rRNA sequences from bacteria found in lichens or arctic plants. For example, an OTU belonging to the uncultured Rhizobiales LAR1 lineage, which is commonly associated with lichens, was observed at high relative abundance in many of the CR samples. Lastly, the taxa shared between the giant trees, arctic plants, and lichens may be part of a broadly defined endophyte microbiome common to temperate, boreal, and

Endophytic Actinobacteria Associated with Dracaena cochinchinensis Lour.: Isolation, Diversity, and Their Cytotoxic Activities.

PubMed

Salam, Nimaichand; Khieu, Thi-Nhan; Liu, Min-Jiao; Vu, Thu-Trang; Chu-Ky, Son; Quach, Ngoc-Tung; Phi, Quyet-Tien; Narsing Rao, Manik Prabhu; Fontana, Angélique; Sarter, Samira; Li, Wen-Jun

2017-01-01

Dracaena cochinchinensis Lour. is an ethnomedicinally important plant used in traditional Chinese medicine known as dragon's blood. Excessive utilization of the plant for extraction of dragon's blood had resulted in the destruction of the important niche. During a study to provide a sustainable way of utilizing the resources, the endophytic Actinobacteria associated with the plant were explored for potential utilization of their medicinal properties. Three hundred and four endophytic Actinobacteria belonging to the genera Streptomyces , Nocardiopsis , Brevibacterium , Microbacterium , Tsukamurella , Arthrobacter , Brachybacterium , Nocardia , Rhodococcus , Kocuria , Nocardioides , and Pseudonocardia were isolated from different tissues of D. cochinchinensis Lour. Of these, 17 strains having antimicrobial and anthracyclines-producing activities were further selected for screening of antifungal and cytotoxic activities against two human cancer cell lines, MCF-7 and Hep G2. Ten of these selected endophytic Actinobacteria showed antifungal activities against at least one of the fungal pathogens, of which three strains exhibited cytotoxic activities with IC 50 -values ranging between 3 and 33  μ g·mL -1 . Frequencies for the presence of biosynthetic genes, polyketide synthase- (PKS-) I, PKS-II, and nonribosomal peptide synthetase (NRPS) among these 17 selected bioactive Actinobacteria were 29.4%, 70.6%, and 23.5%, respectively. The results indicated that the medicinal plant D. cochinchinensis Lour. is a good niche of biologically important metabolites-producing Actinobacteria.

Endophytic Actinobacteria Associated with Dracaena cochinchinensis Lour.: Isolation, Diversity, and Their Cytotoxic Activities

PubMed Central

Salam, Nimaichand; Khieu, Thi-Nhan; Liu, Min-Jiao; Vu, Thu-Trang; Quach, Ngoc-Tung; Phi, Quyet-Tien; Fontana, Angélique; Sarter, Samira

2017-01-01

Dracaena cochinchinensis Lour. is an ethnomedicinally important plant used in traditional Chinese medicine known as dragon's blood. Excessive utilization of the plant for extraction of dragon's blood had resulted in the destruction of the important niche. During a study to provide a sustainable way of utilizing the resources, the endophytic Actinobacteria associated with the plant were explored for potential utilization of their medicinal properties. Three hundred and four endophytic Actinobacteria belonging to the genera Streptomyces, Nocardiopsis, Brevibacterium, Microbacterium, Tsukamurella, Arthrobacter, Brachybacterium, Nocardia, Rhodococcus, Kocuria, Nocardioides, and Pseudonocardia were isolated from different tissues of D. cochinchinensis Lour. Of these, 17 strains having antimicrobial and anthracyclines-producing activities were further selected for screening of antifungal and cytotoxic activities against two human cancer cell lines, MCF-7 and Hep G2. Ten of these selected endophytic Actinobacteria showed antifungal activities against at least one of the fungal pathogens, of which three strains exhibited cytotoxic activities with IC50-values ranging between 3 and 33 μg·mL−1. Frequencies for the presence of biosynthetic genes, polyketide synthase- (PKS-) I, PKS-II, and nonribosomal peptide synthetase (NRPS) among these 17 selected bioactive Actinobacteria were 29.4%, 70.6%, and 23.5%, respectively. The results indicated that the medicinal plant D. cochinchinensis Lour. is a good niche of biologically important metabolites-producing Actinobacteria. PMID:28484706

Chemical constituents of Aspergillus sp EJC08 isolated as endophyte from Bauhinia guianensis and their antimicrobial activity.

PubMed

Pinheiro, Eduardo A A; Carvalho, Josiwander M; Santos, Diellem C P dos; Feitosa, André O; Marinho, Patrícia S B; Guilhon, Giselle Maria S P; Santos, Lourivaldo S; Souza, Afonso L D de; Marinho, Andrey M R

2013-01-01

The present work reports the isolation of five compounds from Aspergillus sp EJC08 isolated as endophytic from Bauhinia guianensis, a tipical plant of the Amazon. The compounds ergosterol (1), ergosterol peroxide (2), mevalolactone (3), monomethylsulochrin (4) and trypacidin A (5) were isolated by chromatographic procedures and identified by spectral methods of 1D and 2D NMR and MS. Compounds 3, 4 and 5 were tested against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus and showed good activity.

Isolation, Purification, and Characterization of Five Active Diketopiperazine Derivatives from Endophytic Streptomyces SUK 25 with Antimicrobial and Cytotoxic Activities.

PubMed

Alshaibani, Muhanna; Zin, Noraziah; Jalil, Juriyati; Sidik, Nik; Ahmad, Siti Junaidah; Kamal, Nurkhalida; Edrada-Ebel, Ruangelie

2017-07-28

In our search for new sources of bioactive secondary metabolites from Streptomyces sp., the ethyl acetate extracts from endophytic Streptomyces SUK 25 afforded five active diketopiperazine (DKP) compounds. The aim of this study was to characterize the bioactive compounds isolated from endophytic Streptomyces SUK 25 and evaluate their bioactivity against multiple drug resistance (MDR) bacteria such as Enterococcus raffinosus, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumanii, Pseudomonas aeruginosa, and Enterobacter spp., and their cytotoxic activities against the human hepatoma (HepaRG) cell line. The production of secondary metabolites by this strain was optimized through Thornton's medium. Isolation, purification, and identification of the bioactive compounds were carried out using high-performance liquid chromatography, high-resolution mass liquid chromatography-mass spectrometry, Fourier transform infrared spectroscopy, and nuclear magnetic resonance, and cryopreserved HepaRG cells were selected to test the cytotoxicity. The results showed that endophytic Streptomyces SUK 25 produces four active DKP compounds and an acetamide derivative, which were elucidated as cyclo -( L -Val- L -Pro), cyclo -( L -Leu- L -Pro), cyclo -( L -Phe- L -Pro), cyclo -( L -Val- L -Phe), and N -(7-hydroxy-6-methyl-octyl)-acetamide. These active compounds exhibited activity against methicillin-resistant S. aureus ATCC 43300 and Enterococcus raffinosus , with low toxicity against human hepatoma HepaRG cells. Endophytic Streptomyces SUK 25 has the ability to produce DKP derivatives biologically active against some MDR bacteria with relatively low toxicity against HepaRG cells line.

Anti-mycobacterial activity of polyketides from Penicillium sp. endophyte isolated from Garcinia nobilis against Mycobacteriumsmegmatis.

PubMed

Jouda, Jean Bosco; Mawabo, Isabelle Kamga; Notedji, Augustin; Mbazoa, Céline Djama; Nkenfou, Jean; Wandji, Jean; Nkenfou, Céline Nguefeu

2016-06-01

According to estimates by the World Health Organization, there were 9.6 million new tuberculosis (TB) cases in 2014: 5.4 million among men, 3.2 million among women, and 1.0 million among children. There were also 1.5 million TB deaths. Although there are potent anti-TB molecules, the misuse of these drugs in addition to inconsistent or partial treatment have led to the development of multidrug-resistant TB and extensively drug-resistant TB. It is established that plants harbor microorganisms, collectively known as endophytes, which also produce metabolites. Exploring the as-yet untapped natural products from the endophytes increases the chances of finding novel and active compounds. The present study was aimed to investigate the antimycobacterial activity of the crude extract and compounds isolated from Penicillium sp. endophyte associated with Garcinia nobilis against Mycobacterium smegmatis. Liquid culture obtained from the fermentation of Penicillium sp. was extracted using ethylacetate and the liquid chromatography-mass spectrometry monitored fractionation of crude extracts yielded six compounds. Their structures were elucidated with spectroscopic analyses including two-dimensional nuclear magnetic resonance, high resolution mass spectrometry by dereplication using Antibase, and by comparison to literature data. All compounds and the crude extract from the liquid medium were evaluated for their antimycobacterial activity against M. smegmatis. In this study, the activity of penialidins A-C (1-3), citromycetin (4), p-hydroxy phenyl glyoxalaldoxime (5), and Brefeldin A (6) were tested against nonpathogenic M. smegmatis. Penialidin C was the most active compound with a minimum inhibitory concentration of 15.6μg/mL. Isolated compounds from Penicillium sp. harbored in G. nobilis exhibited promising antimycobacterial activity against M. smegmatis thus supporting the immensity of the potential of antimycobacterial drug discovery from endophytes from medicinal plants

Infection of Helicoverpa armigera by endophytic Beauveria bassiana colonizing tomato plants

USDA-ARS?s Scientific Manuscript database

A novel endophytic strain of Beauveria bassiana was isolated from leaf tissue of a wild tomato plant. This strain and two B. bassiana strains previously isolated from soil were evaluated for their ability to endophytically colonize tomatoes and subsequent in planta efficacy against Helicoverpa armig...

Huperzine A production by Paecilomyces tenuis YS-13, an endophytic fungus isolated from Huperzia serrata.

PubMed

Su, Jingqian; Yang, Minhe

2015-01-01

Huperzine A (HupA), a naturally occurring alkaloid in the plant family Huperziaceae, has drawn great interest for its potential application in Alzheimer disease therapy. Our primary objective was to identify alkaloid- and HupA-producing fungi from the Chinese folk herb, Huperzia serrata. We established a rapid and efficient model for screening HupA-producing endophytic fungal strains. The presence of HupA in Paecilomyces tenuis YS-13 was analysed by thin-layer chromatography, high-performance liquid chromatography and mass spectrometry. The fermentation yield of HupA was 21.0 μg/L, and the IC50 of the crude extract of YS-13 fermentation broth was 1.27 ± 0.04 mg/mL. This is the first report of P. tenuis as a HupA-producing endophyte isolated from Huperziaceae.

Optimum conditions for L-glutaminase production by actinomycete strain isolated from estuarine fish, Chanos chanos (Forskal, 1775).

PubMed

Sivakumar, K; Sahu, Maloy Kumar; Manivel, P R; Kannan, L

2006-03-01

Actinomycetes were isolated from skin, gills and gut contents of estuarine fish. Chanos chanos using Kuster's agar medium. Out of 20 strains tested, the strain LG-10 which was tentatively identified as Streptomyces rimosus showed L-glutaminase activity. Optimum production of L-glutaminase enzyme (17.51 IU/ml) was observed after 96 h of incubation at 27 degrees C, pH 9 and glucose and malt extract as carbon and nitrogen sources, respectively. The present study indicated scope for the use of S. rimosus as an ideal organism for the industrial production of extracellular L-glutaminase.

Effects of endophytic entomopathogenic fungi on soybean aphid and identification of Metarhizium isolates from agricultural fields.

PubMed

Clifton, Eric H; Jaronski, Stefan T; Coates, Brad S; Hodgson, Erin W; Gassmann, Aaron J

2018-01-01

Terrestrial plants can harbor endophytic fungi that may induce changes in plant physiology that in turn affect interactions with herbivorous insects. We evaluated whether the application of entomopathogenic fungi Beauveria bassiana and Metarhizium brunneum to soybean seeds could become endophytic and affect interactions with soybean aphid (Aphis glycines Matsumura). It was found that A. glycines population sizes increased on plants with M. brunneum (strain F52) seed inoculum, but no significant effects were shown with analogous treatments with B. bassiana (strain GHA). Fungi recovered from soybean plant tissues indicate that endophytism was established, and that B. bassiana was more prevalent. Metarhizium brunneum was only recovered from stems, but B. bassiana was recovered from stems and leaves. This work confirms that some entomopathogenic fungi can be endophytic in soybean, however, some of these fungi may have a negative effect on the plants by increasing susceptibility of soybean to A. glycines. We also used DNA sequence data to identify species of Metarhizium obtained from agricultural fields in Iowa. Phylogenetic analyses, based on DNA sequence data, found that all isolates were Metarhizium robertsii, which is consistent with past studies indicating a cosmopolitan distribution and wide host range for this species. These results are important for understanding the dynamics of implementing environmentally sustainable measures for the control of pest insects.

Endophytic fungi associated with roots of date palm (Phoenix dactylifera) in coastal dunes.

PubMed

Mohamed Mahmoud, Fadila; Krimi, Zoulikha; Maciá-Vicente, Jose G; Brahim Errahmani, Mohamed; Lopez-Llorca, Luis V

Symbiotic interactions with fungal endophytes are argued to be responsible for the tolerance of plants to some stresses and for their adaptation to natural conditions. In this study we aimed to examine the endophytic fungal diversity associated with roots of date palms growing in coastal dune systems, and to screen this collection of endophytes for potential use as biocontrol agents, for antagonistic activity and mycoparasitism, and as producers of antifungal compounds with potential efficacy against root diseases of date palm. Roots of nine individual date palms growing in three coastal locations in the South-East of Spain (Guardamar, El Carabassí, and San Juan) were selected to isolate endophytic fungi. Isolates were identified on the basis of morphological and/or molecular characters. Five hundred and fifty two endophytic fungi were isolated and assigned to thirty morphological taxa or molecular operational taxonomic units. Most isolates belonged to Ascomycota, and the dominant order was Hypocreales. Fusarium and Clonostachys were the most frequently isolated genera and were present at all sampling sites. Comparisons of the endophytic diversity with previous studies, and their importance in the management of the date palm crops are discussed. This is the first study on the diversity of endophytic fungi associated with roots of date palm. The isolates obtained might constitute a source of biological control agents and biofertilizers for use in crops of this plant. Copyright © 2016 Asociación Española de Micología. Publicado por Elsevier España, S.L.U. All rights reserved.

Antimicrobial activity and biodiversity of endophytic fungi in Dendrobium devonianum and Dendrobium thyrsiflorum from Vietnam.

PubMed

Xing, Yong-Mei; Chen, Juan; Cui, Jin-Long; Chen, Xiao-Mei; Guo, Shun-Xing

2011-04-01

Endophytic fungi are rich in orchids and have great impacts on their host plants. 53 endophytes (30 isolates from Dendrobium devonianum and 23 endophytic fungi from D. thyrsiflorum) were isolated, respectively, from roots and stems of Dendrobium species. All the fungi were identified by way of morphological and/or molecular biological methods. 30 endophytic fungi in D. devonianum were categorized into 11 taxa and 23 fungal endophytes in D. thyrsiflorum were grouped into 11 genera, respectively. Fusarium was the dominant species of the two Dendrobium species in common. Antimicrobial activity of ethanol extract of fermentation broth of these fungi was explored using agar diffusion test. 10 endophytic fungi in D. devonianum and 11 in D. thyrsiflorum exhibited antimicrobial activity against at least one pathogenic bacterium or fungus among 6 pathogenic microbes (Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus). Out of the fungal endophytes isolated from D. devonianum and D. thyrsiflorum, Phoma displayed strong inhibitory activity (inhibition zones in diameter >20 mm) against pathogens. Epicoccum nigrum from D. thyrsiflorum exhibited antibacterial activity even stronger than ampicillin sodium. Fusarium isolated from the two Dendrobium species was effective against the pathogenic bacterial as well as fungal pathogens. The study reinforced the assumption that endophytic fungi isolated from different Dendrobium species could be of potential antibacterial or antifungal resource.

Broad-spectrum antimicrobial epiphytic and endophytic fungi from marine organisms: isolation, bioassay and taxonomy.

PubMed

Zhang, Yi; Mu, Jun; Feng, Yan; Kang, Yue; Zhang, Jia; Gu, Peng-Juan; Wang, Yu; Ma, Li-Fang; Zhu, Yan-Hua

2009-04-17

In the search for new marine derived antibiotics, 43 epi- and endophytic fungal strains were isolated from the surface or the inner tissue of different marine plants and invertebrates. Through preliminary and secondary screening, 10 of them were found to be able to produce broad-spectrum antimicrobial metabolites. By morphological and molecular biological methods, three active strains were characterized to be Penicillium glabrum, Fusarium oxysporum, and Alternaria alternata.

Genetic screening strategy for rapid access to polyether ionophore producers and products in actinomycetes.

PubMed

Wang, Hao; Liu, Ning; Xi, Lijun; Rong, Xiaoying; Ruan, Jisheng; Huang, Ying

2011-05-01

Polyether ionophores are a unique class of polyketides with broad-spectrum activity and outstanding potency for the control of drug-resistant bacteria and parasites, and they are produced exclusively by actinomycetes. A special epoxidase gene encoding a critical tailoring enzyme involved in the biosynthesis of these compounds has been found in all five of the complete gene clusters of polyether ionophores published so far. To detect potential producer strains of these antibiotics, a pair of degenerate primers was designed according to the conserved regions of the five known polyether epoxidases. A total of 44 putative polyether epoxidase gene-positive strains were obtained by the PCR-based screening of 1,068 actinomycetes isolated from eight different habitats and 236 reference strains encompassing eight major families of Actinomycetales. The isolates spanned a wide taxonomic diversity based on 16S rRNA gene analysis, and actinomycetes isolated from acidic soils seemed to be a promising source of polyether ionophores. Four genera were detected to contain putative polyether epoxidases, including Micromonospora, which has not previously been reported to produce polyether ionophores. The designed primers also detected putative epoxidase genes from diverse known producer strains that produce polyether ionophores unrelated to the five published gene clusters. Moreover, phylogenetic and chemical analyses showed a strong correlation between the sequence of polyether epoxidases and the structure of encoded polyethers. Thirteen positive isolates were proven to be polyether ionophore producers as expected, and two new analogues were found. These results demonstrate the feasibility of using this epoxidase gene screening strategy to aid the rapid identification of known products and the discovery of unknown polyethers in actinomycetes.

Unexpected diversity of basidiomycetous endophytes in sapwood and leaves of Hevea.

PubMed

Martin, Rachael; Gazis, Romina; Skaltsas, Demetra; Chaverri, Priscila; Hibbett, David

2015-01-01

Research on fungal endophytes has expanded dramatically in recent years, but little is known about the diversity and ecological roles of endophytic basidiomycetes. Here we report the analysis of 310 basidiomycetous endophytes isolated from wild and planted populations of the rubber tree genus, Hevea. Species accumulation curves were nonasymptotic, as in the majority of endophyte surveys, indicating that more sampling is needed to recover the true diversity of the community. One hundred eighteen OTUs were delimited, representing nine orders of Basidiomycota (Agaricales, Atheliales, Auriculariales, Cantharellales, Hymenochaetales, Polyporales, Russulales, Septobasidiales, Tremellales). The diversity of basidiomycetous endophytes found inhabiting wild populations of Hevea was comparable to that present in plantations. However, when samples were segregated by tissue type, sapwood of wild populations was found to contain a higher number of species than sapwood of planted trees. Seventy-five percent of isolates were members of the Polyporales, the majority in the phlebioid clade. Most of the species belong to clades known to cause a white-rot type of wood decay. Two species in the insect-associated genus Septobasidium were isolated. The most frequently isolated genera included Bjerkandera, Ceriporia, Phanerochaete, Phlebia, Rigidoporus, Tinctoporellus, Trametes (Polyporales), Peniophora, Stereum (Russulales) and Coprinellus (Agaricales), all of which have been reported as endophytes from a variety of hosts, across wide geographic locations. Literature records on the geographic distribution and host association of these genera revealed that their distribution and substrate affinity could be extended if the endophytic niche was investigated as part of fungal biodiversity surveys. © 2015 by The Mycological Society of America.

Bioremediation of heavy metals using an endophytic bacterium Paenibacillus sp. RM isolated from the roots of Tridax procumbens.

PubMed

Govarthanan, M; Mythili, R; Selvankumar, T; Kamala-Kannan, S; Rajasekar, A; Chang, Young-Cheol

2016-12-01

The aim of the present study was to assess the bioremediation potential of endophytic bacteria isolated from roots of Tridax procumbens plant. Five bacterial endophytes were isolated and subsequently tested for minimal inhibitory concentration (MIC) against different heavy metals. Amongst the five isolates, strain RM exhibited the highest resistance to copper (750 mg/l), followed by zinc (500 mg/l), lead (450 mg/l), and arsenic (400 mg/l). Phylogenetic analysis of the 16S rDNA sequence suggested that strain RM was a member of genus Paneibacillus. Strain RM also had the capacity to produce secondary metabolites, indole acetic acid, siderophores, 1-aminocyclopropane-1-carboxylate (ACC) deaminase, and biosurfactant and solubilize phosphate. The growth kinetics of strain RM was altered slightly in the presence of metal stress. Temperature and pH influenced the metal removal rate. The results suggest that strain RM can survive under the high concentration of heavy metals and has been identified as a potential candidate for application in bioremediation of heavy metals in contaminated environments.

L-Asparaginase Activity of Fungal Endophytes from Tabernaemontana heyneana Wall. (Apocynaceae), Endemic to the Western Ghats (India)

PubMed Central

Manasa, Chandramouli; Nalini, Monnanda Somaiah

2014-01-01

“Endophytes,” the microbes residing within the plant tissues, are important sources of secondary metabolites. Tabernaemontana heyneana Wall., a medicinal tree, endemic to the Western Ghats with rich ethnobotanical history and unique chemical diversity, was selected to study fungal endophytes and evaluate them for L-asparaginase activity. Healthy plant parts were selected for the isolation of endophytes following standard isolation protocols. A total of 727 isolates belonging to 20 taxa were obtained. The isolates comprised of bark (11%), twig (22%), leaf (43%), fruit (12.0%), and seeds (12%). Endophytes such as Colletotrichum, Curvularia, Fusarium, Phomopsis, Verticillium, and Volutella colonized T. heyneana plant parts. Fusarium sp., Phomopsis spp., isolate Thlf01, and Fusarium solani were the dominant genera of bark, twig, leaf, fruits, and seed samples, respectively. The endophytes were screened for their ability to utilize L-asparagine by plate assay method. Fusarium spp. exhibited a high level of activity among the nine endophytes tested positive for L-asparaginase activity. Studies underline the potentials of endophyte-derived fungal L-asparaginases as sources of chemotherapeutic agents. PMID:27382605

Streptomyces atlanticus sp. nov., a novel actinomycete isolated from marine sponge Aplysina fulva (Pallas, 1766).

PubMed

Silva, Fábio Sérgio Paulino; Souza, Danilo Tosta; Zucchi, Tiago Domingues; Pansa, Camila Cristiane; de Figueiredo Vasconcellos, Rafael Leandro; Crevelin, Eduardo José; de Moraes, Luiz Alberto Beraldo; Melo, Itamar Soares

2016-11-01

The taxonomic position of a novel marine actinomycete isolated from a marine sponge, Aplysina fulva, which had been collected in the Archipelago of Saint Peter and Saint Paul (Equatorial Atlantic Ocean), was determined by using a polyphasic approach. The organism showed a combination of morphological and chemotaxonomic characteristics consistent with its classification in the genus Streptomyces and forms a distinct branch within the Streptomyces somaliensis 16S rRNA gene tree subclade. It is closely related to Streptomyces violascens ISP 5183 T (97.27 % 16S rRNA gene sequence similarity) and Streptomyces hydrogenans NBRC 13475 T (97.15 % 16S rRNA gene sequence similarity). The 16S rRNA gene similarities between the isolate and the remaining members of the subclade are lower than 96.77 %. The organism can be distinguished readily from other members of the S. violacens subclade using a combination of phenotypic properties. On the basis of these results, it is proposed that isolate 103 T (=NRRL B-65309 T  = CMAA 1378 T ) merits recognition as the type strain of a new Streptomyces species, namely Streptomyces atlanticus sp. nov.

Janthinolide A-B, two new 2,5-piperazinedione derivatives from the endophytic Penicillium janthinellum isolated from the soft coral Dendronephthya sp.

PubMed

Xue, Chunmei; Li, Tian; Deng, Zhiwei; Fu, Hongzheng; Lin, Wenhan

2006-12-01

Two new 2,5-piperazinedione derivatives, janthinolide A and B (1-2), along with deoxymycelianamide, griseofulvin and dechlorogriseofulvin were isolated from the fermentation broths of the endophytic fungus Penicillium janthinellum isolated from a soft coral, Dendronephthya sp. Their structures were established by extensive spectroscopic data analysis.

Dark septate endophyte decreases stress on rice plants.

PubMed

Santos, Silvana Gomes Dos; Silva, Paula Renata Alves da; Garcia, Andres Calderin; Zilli, Jerri Édson; Berbara, Ricardo Luis Louro

Abiotic stress is one of the major limiting factors for plant development and productivity, which makes it important to identify microorganisms capable of increasing plant tolerance to stress. Dark septate endophytes can be symbionts of plants. In the present study, we evaluated the ability of dark septate endophytes isolates to reduce the effects of water stress in the rice varieties Nipponbare and Piauí. The experiments were performed under gnotobiotic conditions, and the water stress was induced with PEG. Four dark septate endophytes were isolated from the roots of wild rice (Oryza glumaepatula) collected from the Brazilian Amazon. Plant height as well as shoot and root fresh and dry matter were measured. Leaf protein concentrations and antioxidant enzyme activity were also estimated. The dark septate endophytes were grown in vitro in Petri dishes containing culture medium; they exhibited different levels of tolerance to salinity and water stress. The two rice varieties tested responded differently to inoculation with dark septate endophytes. Endophytes promoted rice plant growth both in the presence and in the absence of a water deficit. Decreased oxidative stress in plants in response to inoculation was observed in nearly all inoculated treatments, as indicated by the decrease in antioxidant enzyme activity. Dark septate endophytes fungi were shown to increase the tolerance of rice plants to stress caused by water deficiency. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Bacterial Microbiota of Rice Roots: 16S-Based Taxonomic Profiling of Endophytic and Rhizospheric Diversity, Endophytes Isolation and Simplified Endophytic Community.

PubMed

Moronta-Barrios, Felix; Gionechetti, Fabrizia; Pallavicini, Alberto; Marys, Edgloris; Venturi, Vittorio

2018-02-11

Rice is currently the most important food crop in the world and we are only just beginning to study the bacterial associated microbiome. It is of importance to perform screenings of the core rice microbiota and also to develop new plant-microbe models and simplified communities for increasing our understanding about the formation and function of its microbiome. In order to begin to address this aspect, we have performed a 16S rDNA taxonomic bacterial profiling of the rhizosphere and endorhizosphere of two high-yield rice cultivars-Pionero 2010 FL and DANAC SD20A-extensively grown in Venezuela in 2014. Fifteen putative bacterial endophytes were then isolated from surface-sterilized roots and further studied in vitro and in planta . We have then performed inoculation of rice seedlings with a simplified community composed by 10 of the isolates and we have tracked them in the course of 30 days in greenhouse cultivation. The results obtained suggest that a set was able to significantly colonize together the rice endorhizospheres, indicating possible cooperation and the ability to form a stable multispecies community. This approach can be useful in the development of microbial solutions for a more sustainable rice production.

Gancidin W, a potential low-toxicity antimalarial agent isolated from an endophytic Streptomyces SUK10

PubMed Central

Zin, Noraziah Mohamad; Baba, Mohd Shukri; Zainal-Abidin, Abu Hassan; Latip, Jalifah; Mazlan, Noor Wini; Edrada-Ebel, RuAngelie

2017-01-01

Endophytic Streptomyces strains are potential sources for novel bioactive molecules. In this study, the diketopiperazine gancidin W (GW) was isolated from the endophytic actinobacterial genus Streptomyces, SUK10, obtained from the bark of Shorea ovalis tree, and it was tested in vivo against Plasmodium berghei PZZ1/100. GW exhibited an inhibition rate of nearly 80% at 6.25 and 3.125 μg kg−1 body weight on day four using the 4-day suppression test method on male ICR strain mice. Comparing GW at both concentrations with quinine hydrochloride and normal saline as positive and negative controls, respectively, 50% of the mice treated with 3.125 μg kg−1 body weight managed to survive for more than 11 months after infection, which almost reached the life span of normal mice. Biochemical tests of selected enzymes and proteins in blood samples of mice treated with GW were also within normal levels; in addition, no abnormalities or injuries were found on internal vital organs. These findings indicated that this isolated bioactive compound from Streptomyces SUK10 exhibits very low toxicity and is a good candidate for potential use as an antimalarial agent in an animal model. PMID:28223778

An Endophytic Fungus, Talaromyces radicus, Isolated from Catharanthus roseus, Produces Vincristine and Vinblastine, Which Induce Apoptotic Cell Death.

PubMed

Palem, Padmini P C; Kuriakose, Gini C; Jayabaskaran, Chelliah

2015-01-01

Endophytic fungi isolated from Catharanthus roseus were screened for the production of vincristine and vinblastine. Twenty-two endophytic fungi isolated from various tissues of C. roseus were characterized taxonomically by sequence analysis of the internal transcribed spacer (ITS) region of rDNA and grouped into 10 genera: Alternaria, Aspergillus, Chaetomium, Colletotrichum, Dothideomycetes, Eutypella, Eutypa, Flavodon, Fusarium and Talaromyces. The antiproliferative activity of these fungi was assayed in HeLa cells using the MTT assay. The fungal isolates Eutypella sp--CrP14, obtained from stem tissues, and Talaromyces radicus--CrP20, obtained from leaf tissues, showed the strongest antiproliferative activity, with IC50 values of 13.5 μg/ml and 20 μg/ml, respectively. All 22 endophytic fungi were screened for the presence of the gene encoding tryptophan decarboxylase (TDC), the key enzyme in the terpenoid indole alkaloid biosynthetic pathway, though this gene could only be amplified from T. radicus--CrP20 (NCBI GenBank accession number KC920846). The production of vincristine and vinblastine by T. radicus--CrP20 was confirmed and optimized in nine different liquid media. Good yields of vincristine (670 μg/l) in modified M2 medium and of vinblastine (70 μg/l) in potato dextrose broth medium were obtained. The cytotoxic activity of partially purified fungal vincristine was evaluated in different human cancer cell lines, with HeLa cells showing maximum susceptibility. The apoptosis-inducing activity of vincristine derived from this fungus was established through cell cycle analysis, loss of mitochondrial membrane potential and DNA fragmentation patterns.

Fungal endophytes in germinated seeds of the common bean, Phaseolus vulgaris

PubMed Central

Parsa, Soroush; García-Lemos, Adriana M.; Castillo, Katherine; Ortiz, Viviana; López-Lavalle, Luis Augusto Becerra; Braun, Jerome; Vega, Fernando E.

2016-01-01

We conducted a survey of fungal endophytes in 582 germinated seeds belonging to 11 Colombian cultivars of the common bean (Phaseolus vulgaris). The survey yielded 394 endophytic isolates belonging to 42 taxa, as identified by sequence analysis of the ribosomal DNA internal transcribed spacer (ITS) region. Aureobasidium pullulans was the dominant endophyte, isolated from 46.7 % of the samples. Also common were Fusarium oxysporum, Xylaria sp., and Cladosporium cladosporioides, but found in only 13.4 %, 11.7 %, and 7.6 % of seedlings, respectively. Endophytic colonization differed significantly among common bean cultivars and seedling parts, with the highest colonization occurring in the first true leaves of the seedlings. PMID:27109374

Streptomyces canalis sp. nov., an actinomycete isolated from an alkali-removing canal.

PubMed

Xie, Yu-Xuan; Han, Xiao-Xue; Luo, Xiao-Xia; Xia, Zhan-Feng; Wan, Chuan-Xing; Zhang, Li-Li

2016-08-01

A novel actinomycete strain, designated TRM 46794-61T, was isolated from an alkali-removing canal in 14th Farms of Xinjiang Production and Construction Corps, north-west China. The isolate contained ll-diaminopimelic acid as the diagnostic diamino acid. The whole-cell sugar patterns of the isolate contained ribose, mannose and glucose. The polar lipids were diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, phosphatidylcholine, phosphatidylinositol, phosphatidylinositol mannoside and two unidentified phospholipids. The predominant menaquinones were MK-9(H2), MK-9(H4), MK-9(H6) and MK-9(H8). The major fatty acids were iso-C16 : 0, anteiso-C17 : 0 and anteiso-C15 : 0. The G+C content of the DNA was 70.4 mol%. Phylogenetic analysis showed that strain TRM 46794-61T had a 16S rRNA gene sequence similarity of 97.6 % with the most closely related species with a validly published name, Streptomyces aidingensis TRM 46012T, and it could be distinguished from all species in the genus Streptomyces based on data from this polyphasic taxonomic study. However, DNA-DNA hybridization studies between strain TRM 46794-61T and S.aidingensis TRM 46012T showed only 45.4 % relatedness. On the basis of these data, strain TRM 46794-61T should be designated as a representative of a novel species of the genus Streptomyces, for which the name Streptomyces canalis sp. nov. is proposed. The type strain is TRM 46794-61T (=CCTCC AA 2015006T=KCTC 39568T).

Screening of Marine Actinomycetes from Segara Anakan for Natural Pigment and Hydrolytic Activities

NASA Astrophysics Data System (ADS)

Asnani, A.; Ryandini, D.; Suwandri

2016-02-01

Marine actinomycetes have become sources of great interest to natural product chemistry due to their new chemical entities and bioactive metabolites. Since April 2010, we have screened actinobacteria from five sites that represent different ecosystems of Segara Anakan lagoon. In this present study we focus on specific isolates, K-2C which covers 1) actinomycetes identification based on morphology observation and 16S rRNA gene; 2) fermentation and isolation of pigment; 3) structure determination of pigment; and 4) hydrolytic enzymes characterization; Methodologies relevant to the studies were implemented accordingly. The results indicated that K-2C was likely Streptomyces fradiae strain RSU15, and the best fermentation medium should contain starch and casein with 21 days of incubation. The isolate has extracellular as well as intracellular pigments. Isolated pigments gave purple color with λmax of 529.00 nm. The pigment was structurally characterized. Interestingly, Streptomyces K-2C was able to produce potential hydrolytic enzymes such as amylase, cellulase, protease, lipase, urease, and nitrate reductase.

Diversity of endophytic fungi of Myricaria laxiflora grown under pre- and post-flooding conditions.

PubMed

Tian, W; Bi, Y H; Zeng, W; Jiang, W; Xue, Y H; Wang, G X; Liu, S P

2015-09-09

Myricaria laxiflora is distributed along the riverbanks of the Yangtze River valley. The Three Gorges Dam has dramatically changed the habitat of M. laxiflora, which has evolved to develop increased resistance to flooding stress. In order to elucidate the relationship between plant endophytic fungi and flooding stress, we isolated and taxonomically characterized the endophytic fungi of M. laxiflora. One hundred and sixty-three fungi were isolated from healthy stems, leaves and roots of M. laxiflora grown under pre- and post-flooding conditions. Culture and isolation were carried out under aerobic and anaerobic conditions. Based on internal transcribed spacer sequence analysis and morphological characteristics, the isolates exhibited abundant biodiversity; they were classified into 5 subphyla, 7 classes, 12 orders, 17 families, and 26 genera. Dominant endophytes varied between pre- and post-flooding plants, among different plant tissues, and between aerobic and anaerobic culture conditions. Aspergillus and Alternaria accounted for more than 55% of all isolates. Although the number of isolates from post-flooding plants was greater, endophytes from pre-flooding plants were more diverse and abundant. Endophytes were distributed preferentially in particular tissues; this affinity was constrained by both the host habitat and the oxygen availability of the host.

Antimicrobial Activity of Medicinal Plants Correlates with the Proportion of Antagonistic Endophytes

PubMed Central

Egamberdieva, Dilfuza; Wirth, Stephan; Behrendt, Undine; Ahmad, Parvaiz; Berg, Gabriele

2017-01-01

Medicinal plants are known to harbor potential endophytic microbes, due to their bioactive compounds. In a first study of ongoing research, endophytic bacteria were isolated from two medicinal plants, Hypericum perforatum and Ziziphora capitata with contrasting antimicrobial activities from the Chatkal Biosphere Reserve of Uzbekistan, and their plant-specific traits involved in biocontrol and plant growth promotion were evaluated. Plant extracts of H. perforatum exhibited a remarkable activity against bacterial and fungal pathogens, whereas extracts of Z. capitata did not exhibit any potential antimicrobial activity. Matrix-assisted laser desorption ionization (MALDI) time-of-flight (TOF) mass spectrometry (MS) was used to identify plant associated culturable endophytic bacteria. The isolated culturable endophytes associated with H. perforatum belong to eight genera (Arthrobacter, Achromobacter, Bacillus, Enterobacter, Erwinia, Pseudomonas, Pantoea, Serratia, and Stenotrophomonas). The endophytic isolates from Z. capitata also contain those genera except Arthrobacter, Serratia, and Stenotrophomonas. H. perforatum with antibacterial activity supported more bacteria with antagonistic activity, as compared to Z. capitata. The antagonistic isolates were able to control tomato root rot caused by Fusarium oxysporum and stimulated plant growth under greenhouse conditions and could thus be a cost-effective source for agro-based biological control agents. PMID:28232827

Arcopilus aureus, a Resveratrol-Producing Endophyte from Vitis vinifera.

PubMed

Dwibedi, Vagish; Saxena, Sanjai

2018-04-14

Resveratrol is extensively being used as a therapeutic moiety, as well as a pharmacophore for development of new drugs due to its multifarious beneficial effects. The objective of the present study was to isolate and screen the resveratrol-producing endophytic fungi from different varieties of Vitis vinifera. A total of 53 endophytic fungi belonging to different fungal genera were isolated from the stem and leaf tissues of Vitis vinifera (merlot, wild, pinot noir, Shiraz, muscat) from different grape-producing locations of India. Only 29 endophytic fungal isolates exhibited a positive test for phenolics by phytochemical methods. The resveratrol obtained after ethyl acetate extraction was confirmed using standard molecule on thin layer chromatography (TLC) with a retention factor (R f ) of 0.69. The purified and standard resveratrol were visualized under UV light as a violet-colored spot. In HPLC analysis of the ethyl acetate extract of culture broth of 11 endophytic isolates, the highest resveratrol content was found in #12VVLPM (89.1 μg/ml) followed by #18VVLPM (37.3 μg/ml) and 193VVSTPM (25.2 μg/ml) exhibiting a retention time of 3.36 min which corresponded to the standard resveratrol. The resveratrol-producing isolates belong to seven genera viz. Aspergillus, Botryosphaeria, Penicillium, Fusarium, Alternaria, Arcopilus, and Lasiodiplodia, and using morphological and molecular methods, #12VVLPM was identified as Arcopilus aureus.

Expression of Russian Wheat Aphid (Homoptera: Aphididae) Resistance in Genotypes of Tall Fescue Harboring Different Isolates of Acremonium Endophyte

Treesearch

S.L. Clement; D.G. Lester; A. Dan Wilson; R.C. Johnson; J.H. Bouton

1996-01-01

Experiments were conducted to compare the expression of Russian wheat aphid, Diurnphis noxia (Mordvilko), resistance in 2 genotypes of tall fescue grass, Festucn arundinacea Schreb., harboring different isolates of the endophytic fungus Acremonium coenophialum Morgan-Jones & cams. Aphids did not select...

Melanogenic actinomycetes from rhizosphere soil-antagonistic activity against Xanthomonas oryzae and plant-growth-promoting traits.

PubMed

Muangham, Supattra; Pathom-Aree, Wasu; Duangmal, Kannika

2015-02-01

A total of 210 melanogenic actinomycetes were isolated from 75 rhizospheric soils using ISP6 and ISP7 agar supplemented with antifungal and antibacterial agents. Their morphological characteristics and the presence of ll-diaminopimelic acid in whole-cell hydrolyzates revealed that all isolates belonged to the genus Streptomyces. Their ability to inhibit the growth of 2 pathogenic rice bacteria, Xanthomonas oryzae pv. oryzae and Xanthomonas oryzae pv. oryzicola, was observed using the agar overlay method. The results indicated that 61.9% of the isolates could inhibit at least one of the tested rice pathogens. Among these, isolate TY68-3 showed the highest antibacterial activity and siderophore production. The 16S rRNA gene sequence analysis of 46 representative isolates revealed that isolates with high similarity to Streptomyces bungoensis were frequently found. The present study indicated the potential of melanogenic actinomycetes for use as biocontrol agents against X. oryzae as well as their diversity in rhizospheric soils.

Fungal Endophyte Diversity in Sarracenia

PubMed Central

Glenn, Anthony; Bodri, Michael S.

2012-01-01

Fungal endophytes were isolated from 4 species of the carnivorous pitcher plant genus Sarracenia: S. minor, S. oreophila, S. purpurea, and S. psittacina. Twelve taxa of fungi, 8 within the Ascomycota and 4 within the Basidiomycota, were identified based on PCR amplification and sequencing of the internal transcribed spacer sequences of nuclear ribosomal DNA (ITS rDNA) with taxonomic identity assigned using the NCBI nucleotide megablast search tool. Endophytes are known to produce a large number of metabolites, some of which may contribute to the protection and survival of the host. We speculate that endophyte-infected Sarracenia may benefit from their fungal associates by their influence on nutrient availability from within pitchers and, possibly, by directly influencing the biota within pitchers. PMID:22427921

Fungal endophyte diversity in Sarracenia.

PubMed

Glenn, Anthony; Bodri, Michael S

2012-01-01

Fungal endophytes were isolated from 4 species of the carnivorous pitcher plant genus Sarracenia: S. minor, S. oreophila, S. purpurea, and S. psittacina. Twelve taxa of fungi, 8 within the Ascomycota and 4 within the Basidiomycota, were identified based on PCR amplification and sequencing of the internal transcribed spacer sequences of nuclear ribosomal DNA (ITS rDNA) with taxonomic identity assigned using the NCBI nucleotide megablast search tool. Endophytes are known to produce a large number of metabolites, some of which may contribute to the protection and survival of the host. We speculate that endophyte-infected Sarracenia may benefit from their fungal associates by their influence on nutrient availability from within pitchers and, possibly, by directly influencing the biota within pitchers.

Fungal endophyte assemblages from ethnopharmaceutically important medicinal trees.

PubMed

Tejesvi, Mysore V; Mahesh, Basavanna; Nalini, Monnanda S; Prakash, Harishchandra S; Kini, Kukkundoor R; Subbiah, Ven; Shetty, Hunthrike S

2006-05-01

Endophytic fungi represent an interesting group of microorganisms associated with the healthy tissues of terrestrial plants. They represent a large reservoir of genetic diversity. Fungal endophytes were isolated from the inner bark segments of ethnopharmaceutically important medicinal tree species, namely Terminalia arjuna, Crataeva magna, Azadirachta indica, Holarrhena antidysenterica, Terminalia chebula, and Butea monosperma (11 individual trees), growing in different regions of southern India. Forty-eight fungal species were recovered from 2200 bark segments. Mitosporic fungi represented a major group (61%), with ascomycetes (21%) and sterile mycelia (18%) the next major groups. Species of Fusarium, Pestalotiopsis, Myrothecium, Trichoderma, Verticillium, and Chaetomium were frequently isolated. Exclusive fungal taxa were recovered from five of the six plant species considered for the study of endophytic fungi. Rarefaction indices for species richness indicated the highest expected number of species for bark segments were isolated from T. arjuna and A. indica (20 species each) and from C. magna (18 species).

Fungal endophytes of aquatic macrophytes: diverse host-generalists characterized by tissue preferences and geographic structure

PubMed Central

Sandberg, Dustin C.; Battista, Lorna J.; Arnold, A. Elizabeth

2014-01-01

Most studies of endophytic symbionts have focused on terrestrial plants, neglecting the ecologically and economically important plants present in aquatic ecosystems. We evaluated the diversity, composition, host- and tissue affiliations, and geographic structure of fungal endophytes associated with common aquatic plants in northern Arizona, USA. Endophytes were isolated in culture from roots and photosynthetic tissues during two growing seasons. A total of 226 isolates representing 60 putative species was recovered from 9,600 plant tissue segments. Although isolation frequency was low, endophytes were phylogenetically diverse and species-rich. Comparisons among the most thoroughly sampled species and reservoirs revealed that isolation frequency and diversity did not differ significantly between collection periods, among species, among reservoirs, or as a function of depth. However, community structure differed significantly among reservoirs and tissue types. Phylogenetic analyses of a focal genus (Penicillium) corroborated estimates of species boundaries and informed community analyses, highlighting clade- and genotype-level affiliations of aquatic endophytes with both sediment- and waterborne fungi, and endophytes of proximate terrestrial plants. Together these analyses provide a first quantitative examination of endophytic associations in roots and foliage of aquatic plants and can be used to optimize survey strategies for efficiently capturing fungal biodiversity at local and regional scales. PMID:24402358

Evaluation of the plant-growth-promoting abilities of endophytic bacteria from the psammophyte Ammodendron bifolium.

PubMed

Zhu, Yanlei; She, Xiaoping

2018-04-01

The objective of this study was to assess the plant-growth-promoting abilities of 45 endophytic bacterial isolates from Ammodendron bifolium through physiological characteristics detection and endophytic bacteria-plant interaction. Each of these isolates exhibited 1 or more plant-growth-promoting traits, but only 11 isolates belonging to the genera Bacillus, Staphylococcus, and Kocuria were capable of promoting seed germination and radicle growth. These results together with the results of the correlation analysis revealed that the completion of seed germination may not be due to IAA production, phosphate solubilization, pellicle formation, and ACC deaminase, protease and lipase production by endophytic bacteria, but may be closely related to amylase and cellulase production. Further, endophytic bacterial isolates with plant-growth-promoting traits may also provide beneficial effects to host plants at different growth stages. Thus, these results are of value for understanding the ecological roles of endophytic bacteria in host plant habitats and can serve as a foundation for further studies of their potential in plant regeneration.

Distribution and antimicrobial potential of endophytic fungi associated with ethnomedicinal plant Melastoma malabathricum L.

PubMed

Mishra, Vineet Kumar; Singh, Garima; Passari, Ajit Kumar; Yadav, Mukesh Kumar; Gupta, Vijai Kumar; Singh, Bhim Pratap

2016-03-01

Distributions of endophytic fungi associated with ethnomedicinal plant Melastoma malabathricum L. was studied and 91 isolates belonging to 18 genera were recovered. The isolates were distributed to sordariomycetes (62.63%), dothideomycetes (19.78%), eurotiomycetes (7.69%), zygomycetes (4.19%), agaricomycetes (1.09%), and mycelia sterilia (4.39%). Based on colony morphology and examination of spores, the isolates were classified into 18 taxa, of which Colletotrichum, Phomopsis and Phoma were dominant, their relative frequencies were 23.07%, 17.58% and 12.08% respectively. The colonization rate of endophytic fungi was determined and found to be significantly higher in leaf segments (50.76%), followed by root (41.53%) and stem tissues (27.69%). All the isolates were screened for antimicrobial activity and revealed that 26.37% endophytic fungi were active against one or more pathogens. Twenty four isolates showing significant antimicrobial activity were identified by sequencing the ITS1-5.8S-ITS2 region of rRNA gene. Results indicated that endophytic fungi associated with leaf were functionally versatile as they showed antimicrobial activity against most of the tested pathogens. The endophytic fungi Diaporthe phaseolorum var. meridionalis (KF193982) inhibited all the tested bacterial pathogens, whereas, Penicillium chermesinum (KM405640) displayed most significant antifungal activity. This seems to be the first hand report to understand the distribution and antimicrobial ability of endophytic fungi from ethno-medicinal plant M. malabathricum.

Biotransformation of ginsenoside Rb1 to ginsenoside Rg3 by endophytic bacterium Burkholderia sp. GE 17-7 isolated from Panax ginseng.

PubMed

Fu, Y; Yin, Z-H; Yin, C-Y

2017-06-01

To isolate a novel endophytic bacterium from Panax ginseng that could have excellent properties in converting ginsenoside Rb1 to ginsenoside Rg3. Based on a 16S rDNA gene sequence, the strain named GE 17-7 was identified as Burkholderia sp. This strain has shown the highest activity in converting ginsenoside Rb1 to 20(S)-ginsenoside Rg3. During the biotransformation of ginsenoside Rb1, the final metabolite was identified by nuclear magnetic resonance analysis and the transformation pathway of ginsenoside Rb1 was also identified by thin-layer chromatography and high performance liquid chromatography analysis in this study. We have successfully isolated a β-glucosidase-producing endophytic bacterium GE 17-7 from P. ginseng. Ginsenoside Rg3 was produced by strain GE 17-7 from ginsenoside Rb1 via ginsenoside Rd. This is the first report of the conversion of major ginsenoside Rb1 into minor ginsenoside Rg3 by fermentation with Burkholderia sp. endophytic bacteria in P. ginseng. These results suggest a new preparation method for ginsenoside Rg3 using strain GE 17-7 in the pharmaceutical industry. © 2017 The Society for Applied Microbiology.

Streptomyces tritici sp. nov., a novel actinomycete isolated from rhizosphere soil of wheat (Triticum aestivum L.).

PubMed

Zhao, Junwei; Shi, Linlin; Li, Wenchao; Wang, Jiabin; Wang, Han; Tian, Yuanyuan; Xiang, Wensheng; Wang, Xiangjing

2018-02-01

Two novel actinomycete isolates, designated strains NEAU-A4 T and NEAU-A3, were isolated from rhizosphere soil of wheat (Triticumaestivum L.) and characterized using a polyphasic approach. Morphological and chemotaxonomic characteristics of the two strains coincided with those of the genus Streptomyces. The 16S rRNA gene sequence analysis showed that the two isolates exhibited 99.6 % 16S rRNA gene sequence similarity with each other and that they were most closely related to Streptomyces violaceorectus DSM 40279 T (98.8, 99.0 %). Phylogenetic analysis based on 16S rRNA gene sequences indicated that the two strains clustered together and formed a separate subclade. Furthermore, a combination of DNA-DNA hybridization results and some physiological and biochemical properties demonstrated that the two strains could be distinguished from its closest relative. Therefore, it is proposed that strains NEAU-A4 T and NEAU-A3 should be classified as representatives of a novel species of the genus Streptomyces, for which the name Streptomycestritici sp. nov. is proposed. The type strain is NEAU-A4 T (=CGMCC 4.7393 T =DSM 104540 T ).

Endophytic fungi associated with Macrosolen tricolor and its host Camellia oleifera.

PubMed

Sheng-Liang, Zhou; Shu-Zhen, Yan; Zhen-Ying, Wu; Shuang-Lin, Chen

2014-06-01

Endophytic fungi play an important role in terrestrial ecosystem, while little is known about those in hemi-parasitic plants, a group of special plants which absorb nutrients from its hosts by haustoria. The relationship of the endophytes in the two parts of the bipartite systems (hemiparasites together with their hosts) is also poorly understood. Endophytic fungi of a hemi-parasitic plant Macrosolen tricolor, and its host plant Camellia oleifera were investigated and compared in this study. M. tricolor contained rich and diversified endophytic fungi (H' = 2.829), which consisted mainly of ascomycetes, distributed in more than ten orders of four classes (Sordariomycetes, Dothideomycetes, Leotiomycetes and Eurotiomycetes) besides Incertae sedis strains (23.2 % of total). In addition, 2.2 % of isolates were identified to be Basidiomycota, all of which belonged to Agaricomycetes. Obvious differences were observed between the endophytic fungal assembles in the leaves and those in the branches of M. tricolor. The endophytic fungi isolated from C. oleifera distributed in nearly same orders of the four classes of Ascomycota and one class (Agaricomycetes) of Basidiomycota as those from M. tricolor with similar proportion. For both M. tricolor and C. oleifera, Valsa sp. was the dominant endophyte species in the leaves, Torula sp. 1 and Fusarium sp. 1 were the dominant endophytic fungi in the branches. The similarity coefficient of the endophyte assembles in the two host was 64.4 %. Canonical correspondence analysis showed that the endophyte assembles of M. tricolor and C. oleifera were significantly different (p < 0.01).

Photosynthetic Bradyrhizobia Are Natural Endophytes of the African Wild Rice Oryza breviligulata

PubMed Central

Chaintreuil, Clémence; Giraud, Eric; Prin, Yves; Lorquin, Jean; Bâ, Amadou; Gillis, Monique; de Lajudie, Philippe; Dreyfus, Bernard

2000-01-01

We investigated the presence of endophytic rhizobia within the roots of the wetland wild rice Oryza breviligulata, which is the ancestor of the African cultivated rice Oryza glaberrima. This primitive rice species grows in the same wetland sites as Aeschynomene sensitiva, an aquatic stem-nodulated legume associated with photosynthetic strains of Bradyrhizobium. Twenty endophytic and aquatic isolates were obtained at three different sites in West Africa (Senegal and Guinea) from nodal roots of O. breviligulata and surrounding water by using A. sensitiva as a trap legume. Most endophytic and aquatic isolates were photosynthetic and belonged to the same phylogenetic Bradyrhizobium/Blastobacter subgroup as the typical photosynthetic Bradyrhizobium strains previously isolated from Aeschynomene stem nodules. Nitrogen-fixing activity, measured by acetylene reduction, was detected in rice plants inoculated with endophytic isolates. A 20% increase in the shoot growth and grain yield of O. breviligulata grown in a greenhouse was also observed upon inoculation with one endophytic strain and one Aeschynomene photosynthetic strain. The photosynthetic Bradyrhizobium sp. strain ORS278 extensively colonized the root surface, followed by intercellular, and rarely intracellular, bacterial invasion of the rice roots, which was determined with a lacZ-tagged mutant of ORS278. The discovery that photosynthetic Bradyrhizobium strains, which are usually known to induce nitrogen-fixing nodules on stems of the legume Aeschynomene, are also natural true endophytes of the primitive rice O. breviligulata could significantly enhance cultivated rice production. PMID:11097925

A Bilobalide-Producing Endophytic Fungus, Pestalotiopsis uvicola from Medicinal Plant Ginkgo biloba.

PubMed

Qian, Yi-Xin; Kang, Ji-Chuan; Luo, Yi-Kai; Zhao, Jun-Jie; He, Jun; Geng, Kun

2016-08-01

For screening bilobalide (BB)-producing endophytic fungi from medicinal plant Ginkgo biloba, a total of 57 fungal isolates were isolated from the internal stem, root, leaf, and bark of the plant G. biloba. Fermentation processes using BB-producing fungi other than G. biloba may become a novel way to produce BB, which is a terpene trilactones exhibiting neuroprotective effects. In this study, a BB-producing endophytic fungal strain GZUYX13 was isolated from the leaves of G. biloba grown in the campus of Guizhou University, Guiyang city, Guizhou province, China. The strain produced BB when grown in potato dextrose liquid medium. The amount of BB produced by this endophytic fungus was quantified to be 106 μg/L via high-performance liquid chromatography (HPLC), substantially lower than that produced by the host tissue. The fungal BB which was analyzed by thin layer chromatography (TLC) and HPLC was proven to be identical to authentic BB. The strain GZUYX13 was identified as Pestalotiopsis uvicola via morphology and ITS rDNA phylogeny. To the best of our knowledge, this is the first report concerning the isolation and identification of endophytic BB-producing Pestalotiopsis spp. from the host plant, which further proved that endophytic fungi have the potential to produce bioactive compounds.

The defensive role of foliar endophytic fungi for a South American tree

PubMed Central

González-Teuber, Marcia

2016-01-01

Fungal endophytes colonize living internal plant tissues without causing any visible symptoms of disease. Endophytic fungi associated with healthy leaves may play an important role in the protection of hosts against herbivores and pathogens. In this study, the diversity of foliar endophytic fungi (FEF) of the southern temperate tree Embothrium coccineum (Proteaceae), as well as their role in plant protection in nature was determined. Fungal endophytes were isolated from 40 asymptomatic leaves by the culture method for molecular identification of the 18S rRNA gene. A relationship between FEF frequency and plant protection was evaluated in juveniles of E. coccineum. Fungal endophyte frequency was estimated using real-time PCR analyses to determine endophyte DNA content per plant. A total of 178 fungal isolates were identified, with sequence data revealing 34 different operational taxonomic units (OTUs). A few common taxa dominated the fungal endophyte community, whereas most taxa qualified as rare. A significant positive correlation between plant protection (evaluated in terms of percentage of leaf damage) and FEF frequency was found. Furthermore, in vitro confrontation assays indicated that FEF were able to inhibit the growth of fungal pathogens. The data showed a relatively high diversity of fungal endophytes associated with leaves of E. coccineum, and suggest a positive relationship between fungal endophyte frequencies in leaves and host protection in nature. PMID:27339046

Taxol-producing [corrected] fungal endophyte, Pestalotiopsis species isolated from Taxus cuspidata.

PubMed

Kumaran, Rangarajulu Senthil; Kim, Hyung Joo; Hur, Byung-Ki

2010-11-01

The endophytic fungi, Pestalotiopsis versicolor and Pestalotiopsis neglecta, were isolated from the healthy leaves and bark of the Japanese Yew tree, Taxus cuspidata. The fungal species were identified by their characteristic culture morphology and molecular analysis. For the first time, the test fungi were screened for the production of taxol in modified liquid medium. The presence of taxol was confirmed by HPLC, (1)H NMR, and LC-MS methods of analysis. The maximum amount of taxol production in P. versicolor was recorded as 478 μg/l. The production rate was increased to 9560-fold than that found in the culture broth of earlier reported fungus, Taxomyces andreanae. The extracted fungal taxol showed a strong cytotoxic activity in the in vitro culture of tested human cancer cells by apoptotic assay indicating that the increase in taxol concentration induces increased cell death. A PCR-based screening for ts, a unique gene in the formation of the taxane skeleton, confirmed the molecular blueprint for taxol biosynthesis. The results designate that the fungal endophyte, P. versicolor, is an excellent candidate for an alternate source of taxol supply and can also serve as a potential species for genetic engineering to enhance the production of taxol to a higher level. Copyright © 2010 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Genetic Screening Strategy for Rapid Access to Polyether Ionophore Producers and Products in Actinomycetes ▿ †

PubMed Central

Wang, Hao; Liu, Ning; Xi, Lijun; Rong, Xiaoying; Ruan, Jisheng; Huang, Ying

2011-01-01

Polyether ionophores are a unique class of polyketides with broad-spectrum activity and outstanding potency for the control of drug-resistant bacteria and parasites, and they are produced exclusively by actinomycetes. A special epoxidase gene encoding a critical tailoring enzyme involved in the biosynthesis of these compounds has been found in all five of the complete gene clusters of polyether ionophores published so far. To detect potential producer strains of these antibiotics, a pair of degenerate primers was designed according to the conserved regions of the five known polyether epoxidases. A total of 44 putative polyether epoxidase gene-positive strains were obtained by the PCR-based screening of 1,068 actinomycetes isolated from eight different habitats and 236 reference strains encompassing eight major families of Actinomycetales. The isolates spanned a wide taxonomic diversity based on 16S rRNA gene analysis, and actinomycetes isolated from acidic soils seemed to be a promising source of polyether ionophores. Four genera were detected to contain putative polyether epoxidases, including Micromonospora, which has not previously been reported to produce polyether ionophores. The designed primers also detected putative epoxidase genes from diverse known producer strains that produce polyether ionophores unrelated to the five published gene clusters. Moreover, phylogenetic and chemical analyses showed a strong correlation between the sequence of polyether epoxidases and the structure of encoded polyethers. Thirteen positive isolates were proven to be polyether ionophore producers as expected, and two new analogues were found. These results demonstrate the feasibility of using this epoxidase gene screening strategy to aid the rapid identification of known products and the discovery of unknown polyethers in actinomycetes. PMID:21421776

Diversity of endophytic yeasts from sweet orange and their localization by scanning electron microscopy.

PubMed

Gai, Cláudia Santos; Lacava, Paulo Teixeira; Maccheroni, Walter; Glienke, Chirlei; Araújo, Welington Luiz; Miller, Thomas Albert; Azevedo, João Lúcio

2009-10-01

Endophytes are microorganisms that colonize plant tissues internally without causing harm to the host. Despite the increasing number of studies on sweet orange pathogens and endophytes, yeast has not been described as a sweet orange endophyte. In the present study, endophytic yeasts were isolated from sweet orange plants and identified by sequencing of internal transcribed spacer (ITS) rRNA. Plants sampled from four different sites in the state of São Paulo, Brazil exhibited different levels of CVC (citrus variegated chlorosis) development. Three citrus endophytic yeasts (CEYs), chosen as representative examples of the isolates observed, were identified as Rhodotorula mucilaginosa, Pichia guilliermondii and Cryptococcus flavescens. These strains were inoculated into axenic Citrus sinensis seedlings. After 45 days, endophytes were re-isolated in populations ranging from 10(6) to 10(9) CFU/g of plant tissue, but, in spite of the high concentrations of yeast cells, no disease symptoms were observed. Colonized plant material was examined by scanning electron microscopy (SEM), and yeast cells were found mainly in the stomata and xylem of plants, reinforcing their endophytic nature. P. guilliermondii was isolated primarily from plants colonized by the causal agent of CVC, Xylella fastidiosa. The supernatant from a culture of P. guilliermondii increased the in vitro growth of X. fastidiosa, suggesting that the yeast could assist in the establishment of this pathogen in its host plant and, therefore, contribute to the development of disease symptoms. Copyright 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Endophytic Colonization and In Planta Nitrogen Fixation by a Herbaspirillum sp. Isolated from Wild Rice Species

PubMed Central

Elbeltagy, Adel; Nishioka, Kiyo; Sato, Tadashi; Suzuki, Hisa; Ye, Bin; Hamada, Toru; Isawa, Tsuyoshi; Mitsui, Hisayuki; Minamisawa, Kiwamu

2001-01-01

Nitrogen-fixing bacteria were isolated from the stems of wild and cultivated rice on a modified Rennie medium. Based on 16S ribosomal DNA (rDNA) sequences, the diazotrophic isolates were phylogenetically close to four genera: Herbaspirillum, Ideonella, Enterobacter, and Azospirillum. Phenotypic properties and signature sequences of 16S rDNA indicated that three isolates (B65, B501, and B512) belong to the Herbaspirillum genus. To examine whether Herbaspirillum sp. strain B501 isolated from wild rice, Oryza officinalis, endophytically colonizes rice plants, the gfp gene encoding green fluorescent protein (GFP) was introduced into the bacteria. Observations by fluorescence stereomicroscopy showed that the GFP-tagged bacteria colonized shoots and seeds of aseptically grown seedlings of the original wild rice after inoculation of the seeds. Conversely, for cultivated rice Oryza sativa, no GFP fluorescence was observed for shoots and only weak signals were observed for seeds. Observations by fluorescence and electron microscopy revealed that Herbaspirillum sp. strain B501 colonized mainly intercellular spaces in the leaves of wild rice. Colony counts of surface-sterilized rice seedlings inoculated with the GFP-tagged bacteria indicated significantly more bacterial populations inside the original wild rice than in cultivated rice varieties. Moreover, after bacterial inoculation, in planta nitrogen fixation in young seedlings of wild rice, O. officinalis, was detected by the acetylene reduction and 15N2 gas incorporation assays. Therefore, we conclude that Herbaspirillum sp. strain B501 is a diazotrophic endophyte compatible with wild rice, particularly O. officinalis. PMID:11679357

Fungal endophytes from seeds of invasive, non-native Phragmites australis and their potential role in germination and seedling growth

USGS Publications Warehouse

Shearin, Zackery R. C.; Filipek, Matthew; Desai, Rushvi; Bickford, Wesley A.; Kowalski, Kurt P.; Clay, Keith

2018-01-01

Background and aimsWe characterized fungal endophytes of seeds of invasive, non-native Phragmites from three sites in the Great Lakes region to determine if fungal symbiosis could contribute to invasiveness through their effects on seed germination and seedling growth.MethodsField-collected seeds were surface sterilized and plated on agar to culture endophytes for ITS sequencing. Prevalence of specific endophytes from germinated and non-germinated seeds, and from seedlings, was compared.ResultsOne-third of 740 seeds yielded endophyte isolates. Fifteen taxa were identified with Alternaria sp. representing 54% of all isolates followed by Phoma sp. (21%) and Penicillium corylophilum (12%). Overall germination of seeds producing an isolate (36%) was significantly higher than seeds not producing an isolate (20%). Penicillium in particular was strongly associated with increased germination of seeds from one site. Sixty-three isolates and 11 taxa were also obtained from 30 seedlings where Phoma, Penicillium and Alternaria respectively were most prevalent. There was a significant effect of isolating an endophyte from the seed on seedling growth.ConclusionsThese results suggest that many endophyte taxa are transmitted in seeds and can increase seed germination and seedling growth of invasive Phragmites. The role of fungal endophytes in host establishment, growth and invasiveness in nature requires further research.

Isolation and Identification of Endophytic Bacteria with Plant Growth Promoting Activity and Biocontrol Potential from Wild Pistachio Trees.

PubMed

Etminani, Faegheh; Harighi, Behrouz

2018-06-01

In this study, samples were collected from the leaves and stems of healthy wild Pistachio trees ( Pistacia atlantica L.) from various locations of Baneh and Marivan regions, Iran. In total, 61 endophytic bacteria were isolated and grouped according to phenotypic properties. Ten selected isolates from each group were further identified by partial sequencing of the 16S rRNA gene. Based on the results, isolates were identified as bacteria belonging to Pseudomonas , Stenotrophomonas , Bacillus , Pantoea and Serratia genus. The ability of these isolates was evaluated to phytohormone production such as auxin and gibberellin, siderophore production, phosphate solubilization, atmospheric nitrogen fixation, protease and hydrogen cyanide production. All strains were able to produce the plant growth hormone auxin and gibberellin in different amounts. The majority of strains were able to solubilize phosphate. The results of atmospheric nitrogen fixation ability, protease and siderophore production were varied among strains. Only Ba66 could produce a low amount of hydrogen cyanide. The results of biocontrol assay showed that Pb78 and Sp15 strains had the highest and lowest inhibition effects on bacterial plant pathogens, Pseudomonas syringae pv. syringae Pss20 and Pseudomonas tolaasii Pt18 under in vitro condition. Pb3, Pb24 and Pb71 strains significantly promote root formation on carrot slices. To our knowledge this is the first report of the isolation of endophytic bacterial strains belonging to Pantoea , Bacillus , Pseudomonas , Serratia and Stenotrophomonas genus from wild pistachio trees with plant growth promoting potential and biocontrol activity.

The isolation and identification of endophytic bacteria from mangrove (Sonneratia alba) that produces gelatinase

NASA Astrophysics Data System (ADS)

Nursyam, H.; Prihanto, A. A.; Warasari, N. I.; Saadah, M.; Masrifa, R. E.; Nabila, N. A.; Istiqfarin, N.; Siddiq, I. J.

2018-04-01

Gelatinase is an enzyme that hydrolyze gelatin into gelatin hydrolyzate. The purpose of this study was to isolate and to identify endophytic bacteria from Sonneratia alba mangrove which able to produce gelatinase enzyme. Sonneratia alba mangroves was obtained from Bajul Mati Beach, Malang Regency. The samples in this study were, stems, and leaves. Pure cultured bacteria were investigated for its capability for producing gelatinase enzyme by using gelatin media. Best producer would further be analyzed its species using microbact system. Screening process resulted in 3 positive isolates, namely code isolate of R, B, and L. R which was isolate from root of S. alba was the best producer for gelatinase. Identification process with morphology and microbact system revelaed that A. SBM is a Gram-negative bacterium that has a basil cell shape, with a diameter colony of 2.19 mm. Based on the microbact system test carried out, the bacteria is Pseudomonas aeruginosa.

Some fungal endophytes from vegetable crops and their anti-oomycete activities against tomato late blight.

PubMed

Kim, H-Y; Choi, G J; Lee, H B; Lee, S-W; Lim, H K; Jang, K S; Son, S W; Lee, S O; Cho, K Y; Sung, N D; Kim, J-C

2007-03-01

To isolate endophytic fungi from vegetable plants and examine their in vivo anti-oomycete activity against Phytophthora infestans in tomato plants. Endophytic fungi were isolated from surface-sterilized plant tissues and anti-oomycete activity was measured by in vivo assay using tomato seedlings. Endophytic fungi showing potent anti-oomycete activity were identified by morphological characteristics and nuclear ribosomal ITS1-5.8S-ITS2 sequence analysis. A total of 152 isolates were obtained from 66 healthy tissue samples of cucumber, red pepper, tomato, pumpkin and Chinese cabbage and the fermentation broths of 23 isolates showed potent in vivo anti-oomycete activity against tomato late blight with control values over 90%. The Fusarium oxysporum strain EF119, which was isolated from roots of red pepper, showed the most potent disease control efficacy against tomato late blight. In dual-culture tests, it inhibited the growth of Pythium ultimum, P. infestans and Phytophthora capsici. Among endophytic fungi isolated from healthy tissues of vegetable plants, F. oxysporum EF119 showed the most potent in vivo anti-oomycete activity against tomato late blight and in vitro anti-oomycete activity against several oomycete pathogens. Endophytic fungi showing anti-oomycete activity in vitro and in vivo may be used as biocontrol agents particularly of tomato late blight.

Endophytic fungi from mangrove inhibit lung cancer cell growth and angiogenesis in vitro.

PubMed

Liu, Xin; Wu, Xin; Ma, Yuefan; Zhang, Wenzhang; Hu, Liang; Feng, Xiaowei; Li, Xiangyong; Tang, Xudong

2017-03-01

The secondary metabolites of mangrove-derived endophytic fungi contain multiple substances with novel structures and biological activities. In the present study, three types of mangrove plants, namely Kandelia candel, Rhizophora stylosa and Rhizophoraceae from Zhanjiang region including the leaves, roots and stems were collected, and endophytic fungi were isolated, purified and identified from these mangrove plants. MTT assay was used to observe the effects of the isolated endophytic fungi on the growth of A549 and NCI-H460 lung cancer cells. The effect of the endophytic fungi on lung cancer angiogenesis in vitro induced by the HPV-16 E7 oncoprotein was observed. Our results showed that 28 strains of endophytic fungi were isolated, purified and identified from the three types of mangrove plants. Ten strains of endophytic fungi significantly suppressed the growth of A549 and NCI-H460 cells. The average inhibitory rates in the A549 cells were 64.4, 59.5, 81.9, 43.9, 58.3, 56.2, 48.3, 42.4, 93.0 and 49.7%, respectively. The average inhibitory rates in the NCI-H460 cells were 41.2, 49.3, 82.7, 40.7, 53.9, 52.6, 56.8, 64.3, 91.0 and 45.6%, respectively. Particularly, three strains of endophytic fungi markedly inhibited HPV-16 E7 oncoprotein‑induced lung cancer angiogenesis in vitro. These findings contribute to the further screening of potential chemotherapeutic agents from mangrove-derived endophytic fungi.

A community of unknown, endophytic fungi in western white pine.

PubMed

Ganley, Rebecca J; Brunsfeld, Steven J; Newcombe, George

2004-07-06

The endophytic fungi of woody plants may be diverse as often claimed, and likewise, they may be functionally novel as demonstrated in a few studies. However, the endophyte taxa that are most frequently reported tend to belong to fungal groups composed of morphologically similar endophytes and parasites. Thus, it is plausible that endophytes are known (i.e., described) parasites in a latent phase within the host. If this null hypothesis were true, endophytes would represent neither additional fungal diversity distinct from parasite diversity nor a symbiont community likely to be novel ecologically. To be synonymous with parasites of the host, endophytes should at least be most closely related to those same parasites. Here we report that seven distinct parasites of Pinus monticola do not occur as endophytes. The majority of endophytes of P. monticola (90% of 2,019 cultures) belonged to one fungal family, the Rhytismataceae. However, not a single rhytismataceous endophyte was found to be most closely related by sequence homology to the three known rhytismataceous parasites of P. monticola. Similarly, neither endophytic Mycosphaerella nor endophytic Rhizosphaera isolates were most closely related to known parasites of P. monticola. Morphologically, the endophytes of P. monticola can be confounded with the parasites of the same host. However, they are actually most closely related to, but distinct from, parasites of other species of Pinus. If endophytes are generally unknown species, then estimates of 1 million endophytes (i.e., approximately 1 in 14 of all species of life) seem reasonable.

Systematic and biotechnological aspects of halophilic and halotolerant actinomycetes.

PubMed

Hamedi, Javad; Mohammadipanah, Fatemeh; Ventosa, Antonio

2013-01-01

More than 70 species of halotolerant and halophilic actinomycetes belonging to at least 24 genera have been validly described. Halophilic actinomycetes are a less explored source of actinomycetes for discovery of novel bioactive secondary metabolites. Degradation of aliphatic and aromatic organic compounds, detoxification of pollutants, production of new enzymes and other metabolites such as antibiotics, compatible solutes and polymers are other potential industrial applications of halophilic and halotolerant actinomycetes. Especially new bioactive secondary metabolites that are derived from only a small fraction of the investigated halophilic actinomycetes, mainly from marine habitats, have revealed the huge capacity of this physiological group in production of new bioactive chemical entities. Combined high metabolic capacities of actinomycetes and unique features related to extremophilic nature of the halophilic actinomycetes have conferred on them an influential role for future biotechnological applications.

Halophilic and halotolerant actinomycetes from a marine saltern of Goa, India producing anti-bacterial metabolites.

PubMed

Ballav, Shuvankar; Kerkar, Savita; Thomas, Sabu; Augustine, Nimmy

2015-03-01

Marine salterns are estuarine ecosystems in Goa, receiving inputs from riverine and marine waters. The Salinity fluctuates between 0 and 300 psu which makes it a conducive niche for salt tolerant and salt loving Actinomycetales. Halotolerant and halophilic Actinomycetales producing anti-bacterial metabolites were studied from crystallizer pond sediments of Ribandar saltern, Goa. Three media viz. Starch casein, R2A and Inorganic salt starch agar at four different salinities (35, 50, 75 and 100 psu) were used for isolation. R2A agar at 35 psu was the most preferred by hypersaline actinomycetes. The dominant group was halotolerant Streptomyces spp. others being rare actinomycetes viz. Nocardiopsis, Micromonospora and Kocuria spp. More than 50% of the isolates showed anti-bacterial activity against one or more of the fifteen human pathogens tested. Eight strains from 4 genera showed consistent anti-bacterial activity and studied in detail. Most halotolerant isolates grew from 0 to 75 psu, with optimum antibiotic production at 35 psu whereas halophiles grew at 20 to 100 psu with optimum antibiotic production at 35 psu. Four Streptomyces strains showed multiple inhibition against test organisms while four rare actinomycetes were specific in their inhibitory activity. This is the first report of a halophilic Kocuria sp., Nocardiopsis sp., and halotolerant Micromonospora sp. producing anti-bacterial compound(s) against Staphylococcus aureus, Staphylococcus citreus, and Vibrio cholerae, respectively. Sequential extraction with varying polarity of organic solvents showed that the extracts inhibited different test pathogens. These results suggest that halophilic and halotolerant actinomycetes from marine salterns are a potential source of anti-bacterial compounds. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Enhanced resistance to Spodoptera litura in endophyte infected cauliflower plants.

PubMed

Thakur, Abhinay; Kaur, Sanehdeep; Kaur, Amarjeet; Singh, Varinder

2013-04-01

Endophytic fungi, which live within host plant tissues without causing any visible symptom of disease, are important mediators of plant-herbivore interactions. These endophytes enhance resistance of host plant against insect herbivores mainly by productions of various alkaloid based defensive compounds in the plant tissue or through alterations of plant nutritional quality. Two endophytic fungi, i.e., Nigrospora sp. and Cladosporium sp., were isolated from Tinospora cordifolia (Thunb.) Miers, a traditional indian medicinal plant. Cauliflower (Brassica oleracea L.) plants were inoculated with these two endophytic fungi. The effect of endophyte infected and uninfected cauliflower plants were measured on the survival and development of Spodoptera litura (Fab.), a polyphagous pest. Endophyte infected cauliflower plants showed resistance to S. litura in the form of significant increase in larval and pupal mortality in both the fungi. Inhibitory effects of endophytic fungi also were observed on adult emergence, longevity, reproductive potential, as well as hatchability of eggs. Thus, it is concluded that antibiosis to S. litura could be imparted by artificial inoculation of endophytes and this could be used to develop alternative ecologically safe control strategies.

Powdered Chitin Agar as a Selective Medium for Enumeration of Actinomycetes in Water and Soil1

PubMed Central

Hsu, S. C.; Lockwood, J. L.

1975-01-01

Agar media made with 0.4% colloidal chitin plus mineral salts and adjusted to pH 8.0 was superior to four other commonly used media for the isolation and enumeration of actinomycetes from water samples. More actinomycetes developed on chitin agar, and the development of bacteria and fungi was suppressed. Frozen and vacuum-dried chitin from aqueous colloidal suspensions was finely divided and gave results comparable to those obtained with media prepared from colloidal suspensions. Images PMID:234719

Draft Genome Sequences of Endophytic Isolates of Klebsiella variicola and Klebsiella pneumoniae Obtained from the Same Sugarcane Plant

PubMed Central

2018-01-01

ABSTRACT Endophytic Klebsiella variicola KvMx2 and Klebsiella pneumoniae KpMx1 isolates obtained from the same sugarcane stem were used for whole-genome sequencing. The genomes revealed clear differences in essential genes for plant growth, development, and detoxification, as well as nitrogen fixation, catalases, cellulases, and shared virulence factors described in the K. pneumoniae pathogen. PMID:29567733

Linking Bacterial Endophytic Communities to Essential Oils: Clues from Lavandula angustifolia Mill

PubMed Central

Emiliani, Giovanni; Maida, Isabel; Perrin, Elena; Chiellini, Carolina; Fondi, Marco; Gallo, Eugenia; Gori, Luigi; Maggini, Valentina; Vannacci, Alfredo; Biffi, Sauro; Firenzuoli, Fabio; Fani, Renato

2014-01-01

Endophytic bacteria play a crucial role in plant life and are also drawing much attention for their capacity to produce bioactive compounds of relevant biotechnological interest. Here we present the characterisation of the cultivable endophytic bacteria of Lavandula angustifolia Mill.—a species used since antiquity for its therapeutic properties—since the production of bioactive metabolites from medical plants may reside also in the activity of bacterial endophytes through their direct production, PGPR activity on host, and/or elicitation of plant metabolism. Lavender tissues are inhabited by a tissue specific endophytic community dominated by Proteobacteria, highlighting also their difference from the rhizosphere environment where Actinobacteria and Firmicutes are also found. Leaves' endophytic community resulted as the most diverse from the other ecological niches. Overall, the findings reported here suggest: (i) the existence of different entry points for the endophytic community, (ii) its differentiation on the basis of the ecological niche variability, and (iii) a two-step colonization process for roots endophytes. Lastly, many isolates showed a strong inhibition potential against human pathogens and the molecular characterization demonstrated also the presence of not previously described isolates that may constitute a reservoir of bioactive compounds relevant in the field of pathogen control, phytoremediation, and human health. PMID:24971151

Culturable endophytic bacterial communities associated with field-grown soybean.

PubMed

de Almeida Lopes, K B; Carpentieri-Pipolo, V; Oro, T H; Stefani Pagliosa, E; Degrassi, G

2016-03-01

Assess the diversity of the culturable endophytic bacterial population associated with transgenic and nontransgenic soybean grown in field trial sites in Brazil and characterize them phenotypically and genotypically focusing on characteristics related to plant growth promotion. Endophytic bacteria were isolated from roots, stems and leaves of soybean cultivars (nontransgenic (C) and glyphosate-resistant (GR) transgenic soybean), including the isogenic BRS133 and BRS245RR. Significant differences were observed in bacterial densities in relation to genotype and tissue from which the isolates were obtained. The highest number of bacteria was observed in roots and in GR soybean. Based on characteristics related to plant growth promotion, 54 strains were identified by partial 16S rRNA sequence analysis, with most of the isolates belonging to the species Enterobacter ludwigii and Variovorax paradoxus. Among the isolates, 44·4% were able to either produce indoleacetic acid (IAA) or solubilize phosphates, and 9·2% (all from GR soybean) presented both plant growth-promoting activities. The results from this study indicate that the abundance of endophytic bacterial communities of soybean differs between cultivars and in general it was higher in the transgenic cultivars than in nontransgenic cultivars. BRS 245 RR exhibited no significant difference in abundance compared to nontransgenic BRS133. This suggests that the impact of the management used in the GR soybean fields was comparable with the impacts of some enviromental factors. However, the bacterial endophytes associated to GR and nontransgenic soybean were different. The soybean-associated bacteria showing characteristics related to plant growth promotion were identified as belonging to the species Pantoea agglomerans and Variovorax paradoxus. Our study demonstrated differences concerning compostion of culturable endophytic bacterial population in nontransgenic and transgenic soybean. © 2016 The Society for Applied

[Screening endophytic bacteria against plant-parasitic nematodes].

PubMed

Peng, Shuang; Yan, Shuzhen; Chen, Shuanglin

2011-03-01

Plant-parasite nematode is one of the most important pathogens in plant. Our objective is to screen endophytic bacteria against plant-parasitic nematodes from plant. Endophytic bacteria were isolated and screened by testing their metabolite against Bursaphelenchus xylophilus in vitro. Those strains inhibiting B. xylophilus were selected to culture in liquid medium and fermentation conditions were optimized by orthogonal test. The stability of the antinematode substances was evaluated by various. In addition, four strains were identified by 16SrDNA sequence analysis. In total 13 strains of endophytic bacteria secreting antinematode metabolite were isolated from 6 species of plant. The supernatant of the fermentation broth of these endophytic bacteria gave 100% mortality of nematodes after treated as the follows: 1 ml each was mixed with 0.2 ml of the suspension of nematodes (2000 nematodes/ml) then incubated at 250C for 24 h, some of which could led to leakage or dissolution of nematodes. Among them, four strains, BCM2, SZ5, CCM7 and DP1, showed stronger activity than others. The supernatants diluted three times also gave not less than 95% mortality after 24 h treatment, and those from DP1 and SZ5 even gave 100% mortality. The fermentation conditions of the four strains were optimized and the antinematode activity grew up four times after optimization. The antinematode substances of these strains were found stable when treated with protease or heating or stored at 4 degrees C after 100 days, while instable when treated with acid or alkali. DP1 and CCM7 were identified to be Bacillus subtilis, while SZ5 and BCM2 to be Bacillus cereus. Endophytic bacteria secreting antinematode metabolite were found in economic crops. The metabolite of some strains showed strong and stable antinematode activity. Our results indicate the real potential of biocontrol by endophytic bacteria.

Effects of Water Stress on the Endophytic Fungal Communities of Pinus koraiensis Needles Infected by Cenangium ferruginosum

PubMed Central

Lee, Sun Keun; Lee, Seung Kyu; Bae, Hanhong; Seo, Sang-Tae

2014-01-01

To examine the effects of water stress and Cenangium ferruginosum (CF) on the fungal endophytic community of needles of Pinus koraiensis (PK), fungal endophytes isolated from the needles of 5-year-old PK seedlings were compared before and after exposure to water stress conditions and artificial inoculation with CF ascospores. Artificial CF inoculation was successfully confirmed using PCR with CF-specific primers (CfF and CfR). For comparison of the degree of water deficit in water-stressed and control groups of PK seedlings infected with CF, the water saturation deficit and water potential were measured. Lower water potential estimates were found in the water-stressed seedlings than in the control group. The fungal endophytes isolated from the second-year needles of non-water-stressed seedlings before and after CF inoculation revealed that primary saprobes were approximately 30% and 71.7%, respectively, and the remaining endophytes were rot fungi or pathogens. Sixty days after CF inoculation, diverse fungal endophytes in the first-year needles were isolated from the water-stressed seedlings. However, some fungal endophytes isolated from the non-water-stressed seedlings were also identified. Fungal endophytes in the second-year needles of the water-stressed and non-water-stressed seedlings were approximately 8% and 71.7% of saprobes, respectively, and the remaining endophytes were rot fungi or pathogens. On the basis of the results, we conclude that water deficit and CF can have an effect on fungal endophytic communities in the needles of PK seedlings. PMID:25606004

Endophytic Colletrotrichum spp. from Cinchona calisaya wedd. and it's potential quinine production as antibacterial and antimalaria

NASA Astrophysics Data System (ADS)

Radiastuti, Nani; Mutea, Dalli; Sumarlin, La Ode

2017-02-01

An endophytic fungus is microorganisms that live inside plant tissues without harming its host and is capable of producing the same secondary metabolites as its host plant. The endophytic fungus is very diverse and important group of microorganisms. The objectives of the study are to identify endophyte Colletotrichum spp. using ITS rDNA analyze, alkaloid cinchona and antibacterial characteristics. Phylogenetic analysis of ITS rDNA regions and morphology are used to identify the species. The Chloroform extracts of filtrate were analyzed using the High Pressure Liquid Chromatography (HPLC) to determine the production of quinine. There were 13 isolates of Colletotrichum spp as endophytes with associated with Cinchona calisaya Wedd. from fruit (6 isolates), leaf (5 isolates), twig (1 isolate) and root (1 isolate). This is the first report as endophytes are associated with C. calisaya. Based on ITS phylogenetic analysis are introduced of 7 strains Colletotrichum sp, 1 strain closely with C. aegnigma, 2 strains closely C. cordylinicola, 1 strains C arxii, 2 strains nested C. karstii. The Colletotrichum sp. M1 (leaf), M3 (bark), M8 (fruit) and C. karstii M5 (fruit) are potential alkaloid quinine. Five strains of Colletotrichum spp. have antibacterial activity are selected against Staphylococcus aureus and nine Colletotrichum spp. against Escherichia coli. The endophyte identification of Colletotrichum species needs another gene other than ITS rDNA.

[Separation and identification of endophytic fungi from desert plant Cynanchum komarovii].

PubMed

Duan, Hai-Jing; Han, Ting; Wu, Xiu-Li; Li, Na; Chen, Jing; Qin, Lu-Ping

2013-02-01

The research aimed to investigate the entophytic fungal community of Cynanchum Komarrovii, including the biodiversity in different organs and the correlations with ecological environment. Endophytic fungi with patent bioactivity were also rapidly screened. PDA medium was used to isolate and purify the endophytic fungi from C. komarovii living in Shaanxi and Ningxia district, respectively. The strains were identified based on the morphological characteristics of the fungi and similarity of 5.8S gene and internal transcribed spacer (ITS) sequence. Pyriculaia oryzae model was applied to preliminarily screen the active fungi. Ninety-four strains of endophytic fungi were isolated and identified to 9 species, 13 genera, 9 families and 6 orders, among them, 47 strains were from the plants living in Ningxia. And then, 5 of them were isolated from roots, 14 from branches, and 28 from leaves. They were identified belonging to 8 species, 9 genera, 5 families and 4 orders. Additionally, 47 strains were from the plants living in Shaanxi. 16 were isolated from the roots, 18 from branches, 13 from leaves. They were identified belonging to 5 species, 8 genera, 6 families and 4 orders. By preliminary screening, 18 strains of endophytes completely inhibited the germination of conidium, which showed a potential bioactivity for these fungi. Both N4 and S17 strains had stronger growth inhibition effect. Endophytic fungi from desert plant C. komarovii have the feature of diversity. Different geographical environment and type of organizations lead to the significant difference on the quantity and the species composition. Most of fungi in Ningxia C. komarovii distribute in leaves. However, most of those in Shaanxi C. komarovii distribute in stems and leaves. It also indicated that endophytes from C. komarovii had a strong antifungal activity.

Isolation and Identification of Endophytic Bacteria with Plant Growth Promoting Activity and Biocontrol Potential from Wild Pistachio Trees

PubMed Central

Etminani, Faegheh; Harighi, Behrouz

2018-01-01

In this study, samples were collected from the leaves and stems of healthy wild Pistachio trees (Pistacia atlantica L.) from various locations of Baneh and Marivan regions, Iran. In total, 61 endophytic bacteria were isolated and grouped according to phenotypic properties. Ten selected isolates from each group were further identified by partial sequencing of the 16S rRNA gene. Based on the results, isolates were identified as bacteria belonging to Pseudomonas, Stenotrophomonas, Bacillus, Pantoea and Serratia genus. The ability of these isolates was evaluated to phytohormone production such as auxin and gibberellin, siderophore production, phosphate solubilization, atmospheric nitrogen fixation, protease and hydrogen cyanide production. All strains were able to produce the plant growth hormone auxin and gibberellin in different amounts. The majority of strains were able to solubilize phosphate. The results of atmospheric nitrogen fixation ability, protease and siderophore production were varied among strains. Only Ba66 could produce a low amount of hydrogen cyanide. The results of biocontrol assay showed that Pb78 and Sp15 strains had the highest and lowest inhibition effects on bacterial plant pathogens, Pseudomonas syringae pv. syringae Pss20 and Pseudomonas tolaasii Pt18 under in vitro condition. Pb3, Pb24 and Pb71 strains significantly promote root formation on carrot slices. To our knowledge this is the first report of the isolation of endophytic bacterial strains belonging to Pantoea, Bacillus, Pseudomonas, Serratia and Stenotrophomonas genus from wild pistachio trees with plant growth promoting potential and biocontrol activity. PMID:29887777

[Biodiversity of phosphate-dissolving and plant growth--promoting endophytic bacteria of two crops].

PubMed

Huang, Jing; Sheng, Xiafang; He, Linyan

2010-06-01

We isolated and characterized phosphate-dissolving endophytic bacteria from two commonly cultivated crops. Phosphate-dissolving endophytic bacteria were isolated by plating and screening from interior tissues of rape and maize plants on NBRIP medium with tricalcium phosphate as sole phosphate source. Bacteria were characterized regarding characteristics that may be relevant for a beneficial plant-microbe interaction-indoleacetic acid, siderophore and 1-aminocyclopropane-1-carboxylic acid deaminase production,and further classified by restriction analysis of 16S rDNA. Eleven typical strains were identified by 16S rDNA sequence analysis. Thirty-two phosphate-dissolving endophytic bacteria were isolated from maize and rape plants and classified by restriction analysis of 16S rDNA in 8 different taxonomic groups at the similarity level of 76%. All the isolates could release phosphate from tricalcium phosphate and decrease the pH of the medium. The maximum phosphate content (537.6 mg/L) in the solution was obtained with strain M1L5. Thirteen isolates isolated from rape produced indoleacetic acid and siderophore, 68.4% and 63.2% of the strains isolated from maize produced indoleacetic acid and siderophore,respectively. 63.2% of the strains isolated from maize were able to grow on 1-aminocyclopropane-1-carboxylic acid as the sole nitrogen source. The eleven strains belonged to five different genera including Pantoea, Pseudomonas, Burkholderia, Acinetobacter and Ralstonia. Phosphate-dissolving endophytic bacteria isolated from rape and maize plants have abundant characteristics relative to promoting plant growth and genetic diversity.

Fungal endophytes of South China blueberry (Vaccinium dunalianum var. urophyllum).

PubMed

Li, Z-J; Shen, X-Y; Hou, C-L

2016-12-01

A total of 374 fungal endophyte strains were isolated from of Vaccinium dunalianum var. urophyllum (Ericaceae), a well-known cultivated blueberry in southern China. These fungal endophytes could be categorized into 25 morphotypes according to culture characteristics and molecular identification based on the internal transcribed spacer region. All of these isolates belonged to Ascomycota. Jaccard's (Jc) and Sorenson's similarity indices indicated that the species communities from the fruits and branches were closer to each other than to those from leaves. The leaves appeared to host the highest fungal biodiversity, and the fruits displayed the lowest diversity. This study is the first on endophytic fungi isolated from fruits, branches and leaves of blueberry plants. The results contribute to the body of knowledge on the biocontrol of pathogens associated with blueberry and develop the improvement of plant growth. By comparing with the different fungal communities, the leaves appeared to host the highest biodiversity. © 2016 The Society for Applied Microbiology.

Draft Genome Sequences of Endophytic Isolates of Klebsiella variicola and Klebsiella pneumoniae Obtained from the Same Sugarcane Plant.

PubMed

Reyna-Flores, Fernando; Barrios-Camacho, Humberto; Dantán-González, Edgar; Ramírez-Trujillo, José Augusto; Lozano Aguirre Beltrán, Luis Fernando; Rodríguez-Medina, Nadia; Garza-Ramos, Ulises; Suárez-Rodríguez, Ramón

2018-03-22

Endophytic Klebsiella variicola KvMx2 and Klebsiella pneumoniae KpMx1 isolates obtained from the same sugarcane stem were used for whole-genome sequencing. The genomes revealed clear differences in essential genes for plant growth, development, and detoxification, as well as nitrogen fixation, catalases, cellulases, and shared virulence factors described in the K. pneumoniae pathogen. Copyright © 2018 Reyna-Flores et al.

Isolation of endophytic fungi from Dioscorea zingiberensis C. H. Wright and application for diosgenin production by solid-state fermentation.

PubMed

Xiang, Haibo; Zhang, Tao; Pang, Xu; Wei, Yuzhen; Liu, Hongyu; Zhang, Yuqin; Ma, Baiping; Yu, Liyan

2018-05-03

In this study, endophytic fungi were isolated from Dioscorea zingiberensis C.H. Wright (DZW), and a novel clean process to prepare diosgenin from DZW was developed. A total of 123 strains of endophytic fungi were isolated from different plant tissues of DZW. Among them, the strain Fusarium sp. (CPCC 400709) showed the best activity of hydrolyzing steroidal saponins in DZW into diosgenin. Thus, this strain was used to prepare diosgenin from DZW by solid-state fermentation. The fermentation parameters were optimized using response surface methodology, and a high yield of diosgenin (2.16%) was obtained at 14.5% ammonium sulfate, an inoculum size of 12.3%, and 22 days of fermentation. Furthermore, the highest diosgenin yield (2.79%) was obtained by co-fermentation with Fusarium sp. (CPCC 400709) and Curvularia lunata (CPCC 400737), which was 98.9% of that obtained by β-glucosidase pretreated acid hydrolysis (2.82%). This process is acid-free and wastewater-free, and shows promise as an effective and clean way to prepare diosgenin for use in industrial applications from DZW.

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

Optimization of Antimicrobial Production by a Marine Actinomycete Streptomyces afghaniensis VPTS3-1 Isolated from Palk Strait, East Coast of India.

PubMed

Vijayakumar, R; Panneerselvam, K; Muthukumar, C; Thajuddin, N; Panneerselvam, A; Saravanamuthu, R

2012-06-01

Totally 25 marine soil samples were collected from the region of Palk Strait of Bay of Bengal, Tamil Nadu, and were subjected to the isolation of actinomycetes. Sixty-eight morphologically distinct isolates were obtained and 37% (25) of them had antimicrobial activity. The potential producer was named as Streptomyces sp. VPTS3-1 and the phylogenetic evaluation on the basis of 16S rDNA sequence further categorized the organism as Streptomyces afghaniensis VPTS3-1. Further, the antimicrobial compound was extracted from the isolate using various solvents and the antimicrobial efficacies were tested against bacterial and fungal pathogens. In addition, in vitro optimization of parameters for the antimicrobial compound production revealed that the suitable pH as 7-8, the period of incubation as 9 days, temperature (30°C), salinity (2%), and starch and KNO3 as the suitable carbon and nitrogen sources respectively in starch-casein medium.

Streptomyces salilacus sp. nov., an actinomycete isolated from a salt lake.

PubMed

Luo, Xiao-Xia; Gao, Guang-Bin; Xia, Zhan-Feng; Chen, Zheng-Jun; Wan, Chuan-Xing; Zhang, Li-Li

2018-05-01

The taxonomic position of a novel actinomycete, strain TRM 41337 T , isolated from sediment of a salt lake, Xiaoerkule Lake, Xinjiang, China, was determined by a polyphasic approach. Strain TRM 41337 T grew optimally at 28 °C and in the presence of 1 % (w/v) NaCl. It grew at up to pH 12. The whole-cell sugars of strain TRM 41337 T were ribose and xylose. The diagnostic diamino acid contained ll-diaminopimelic acid. The polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositolmannoside and two other unidentified phospholipids. The predominant menaquinones were MK-9(H8), MK-9, MK-9(H4) and MK-9(H6). The major fatty acids were iso-C16 : 0, anteiso-C15 : 0, anteiso-C17 : 0 and iso-C16 : 1 H. Based on morphological and chemotaxonomic characteristics, the isolate was determined to belong to the genus Streptomyces. The phylogenetic tree based on its nearly complete 16S rRNA gene sequence (1498 nt) with representative strains showed that the strain consistently falls into a distinct phyletic lineage together with Streptomyces barkulensis DSM 42082 T (97.48 % similarity) and a subclade consisting of Streptomyces fenghuangensis GIMN 4.003 T (97.20 %), Streptomyces macrosporus NBRC 14748 T (97.14 %) and Streptomyces radiopugnans R97 T (97.01 %). On the basis of these data, strain TRM 41337 T should be designated as a representative of a novel species of the genus Streptomyces, for which the name Streptomyces salilacus sp. nov. is proposed. The type strain is TRM 41337 T (=CCTCC AA 2015030 T =KCTC 39726 T ).

Chemical ecology of antibiotic production by actinomycetes.

PubMed

van der Meij, Anne; Worsley, Sarah F; Hutchings, Matthew I; van Wezel, Gilles P

2017-05-01

Actinomycetes are a diverse family of filamentous bacteria that produce a plethora of natural products relevant for agriculture, biotechnology and medicine, including the majority of the antibiotics we use in the clinic. Rather than as free-living bacteria, many actinomycetes have evolved to live in symbiosis with among others plants, fungi, insects and sponges. As a common theme, these organisms profit from the natural products and enzymes produced by the actinomycetes, for example, for protection against pathogenic microbes, for growth promotion or for the degradation of complex natural polymers such as lignocellulose. At the same time, the actinomycetes benefit from the resources of the hosts they interact with. Evidence is accumulating that these interactions control the expression of biosynthetic gene clusters and have played a major role in the evolution of the high chemical diversity of actinomycete-produced secondary metabolites. Many of the biosynthetic gene clusters for antibiotics are poorly expressed under laboratory conditions, but they are likely expressed in response to host-specific demands. Here, we review the environmental triggers and cues that control natural product formation by actinomycetes and provide pointers as to how these insights may be harnessed for drug discovery. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Interaction between endophytic bacteria from citrus plants and the phytopathogenic bacteria Xylella fastidiosa, causal agent of citrus-variegated chlorosis.

PubMed

Lacava, P T; Araújo, W L; Marcon, J; Maccheroni, W; Azevedo, J L

2004-01-01

To isolate endophytic bacteria and Xylella fastidiosa and also to evaluate whether the bacterial endophyte community contributes to citrus-variegated chlorosis (CVC) status in sweet orange (Citrus sinensis [L.] Osbeck cv. Pera). The presence of Xylella fastidiosa and the population diversity of culturable endophytic bacteria in the leaves and branches of healthy, CVC-asymptomatic and CVC-symptomatic sweet orange plants and in tangerine (Citrus reticulata cv. Blanco) plants were assessed, and the in vitro interaction between endophytic bacteria and X. fastidiosa was investigated. There were significant differences in endophyte incidence between leaves and branches, and among healthy, CVC-asymptomatic and CVC-symptomatic plants. Bacteria identified as belonging to the genus Methylobacterium were isolated only from branches, mainly from those sampled from healthy and diseased plants, from which were also isolated X. fastidiosa. The in vitro interaction experiments indicated that the growth of X. fastidiosa was stimulated by endophytic Methylobacterium extorquens and inhibited by endophytic Curtobacterium flaccumfaciens. This work provides the first evidence of an interaction between citrus endophytic bacteria and X. fastidiosa and suggests a promising approach that can be used to better understand CVC disease.

Extremophilic and extremotolerant actinomycetes in different soil types

NASA Astrophysics Data System (ADS)

Zenova, G. M.; Manucharova, N. A.; Zvyagintsev, D. G.

2011-04-01

Problems on the resistance of soil actinomycetes to various environmental factors (pH, salinity, temperature, and moisture) are discussed. Actinomycetes as a special group of prokaryotes were revealed to have a greater range of tolerance to these factors than was thought earlier. The regularities of the distribution of extremophilic and extremotolerant actinomycetes developing in unusual for mycelial bacteria conditions, their structural-functional characteristics, and their taxonomic composition were determined. The predominance of acidophilic representatives of the Micromonospora genus in acid soils (typical peat, soddy-podzolic, and taiga podzol) and the haloalkaliphilic Streptomyces pluricilirescens and S. prunicolor species in desert saline soils are shown. The specific features of the actinomycete complexes on thermal fields of the weakly developed stratified volcanic soils are described. In these complexes, the thermophilic forms were represented only by species of the Micromonospora genus; and the mesophilic forms, by Microbispora species. In the periodically heated desert soils, among the thermophilic actinomycetes, representatives of rare Actinomadura, Saccharopolyspora and Streptosporangium genera along with Streptomyces species were indicated. The mechanisms of the resistance of the actinomycetes to the extreme environmental conditions are discussed.

Fungal endophyte diversity in Sarracenia

USDA-ARS?s Scientific Manuscript database

Fungal endophytes were isolated from four species of the carnivorous pitcher plant genus Sarracenia: S. minor, S. oreophila, S. purpurea, and S. psittacina. Twelve taxa of fungi, eight within the Ascomycota and four within the Basidiomycota, were identified based on PCR amplification and sequencing ...

Endophytic Paraconiothyrium sp. from Zingiber officinale Rosc. Displays Broad-Spectrum Antimicrobial Activity by Production of Danthron.

PubMed

Anisha, C; Sachidanandan, P; Radhakrishnan, E K

2018-03-01

The bioactivity spectrum of fungal endophytes isolated from Zingiber officinale was analyzed against clinical pathogens and against the phytopathogen Pythium myriotylum, which causes Pythium rot in ginger. One of the isolates GFM13 showed broad bioactivity against various pathogens tested including P. myriotylum. The spore suspension as well as the culture filtrate of the endophytic fungal isolate was found to effectively protect ginger rhizomes from Pythium rot. By molecular identification, the fungal endophyte was identified as Paraconiothyrium sp. The bioactive compound produced by the isolate was separated by bioactivity-guided fractionation and was identified by GC-MS as danthron, an anthraquinone derivative. PCR amplification showed the presence of non-reducing polyketide synthase gene (NR-PKS) in the endophyte GFM13, which is reported to be responsible for the synthesis of anthraquinones in fungi. This is the first report of danthron being produced as the biologically active component of Paraconiothyrium sp. Danthron is reported to have wide pharmaceutical and agronomic applications which include its use as a fungicide in agriculture. The broad-spectrum antimicrobial activity of danthron and the endophytic origin of Paraconiothyrium sp. offer immense applications of the study.

Cytotoxic and Antifungal Constituents Isolated from the Metabolites of Endophytic Fungus DO14 from Dendrobium officinale.

PubMed

Wu, Ling-Shang; Jia, Min; Chen, Ling; Zhu, Bo; Dong, Hong-Xiu; Si, Jin-Ping; Peng, Wei; Han, Ting

2015-12-22

Two novel cytotoxic and antifungal constituents, (4S,6S)-6-[(1S,2R)-1, 2-dihydroxybutyl]-4-hydroxy-4-methoxytetrahydro-2H-pyran-2-one (1), (6S,2E)-6-hydroxy-3-methoxy-5-oxodec-2-enoic acid (2), together with three known compounds, LL-P880γ (3), LL-P880α (4), and Ergosta-5,7,22-trien-3b-ol (5) were isolated from the metabolites of endophytic fungi from Dendrobium officinale. The chemical structures were determined based on spectroscopic methods. All the isolated compounds 1-5 were evaluated by cytotoxicity and antifungal effects. Our present results indicated that compounds 1-4 showed notable anti-fungal activities (minimal inhibitory concentration (MIC) ≤ 50 μg/mL) for all the tested pathogens including Candida albicans, Cryptococcus neoformans, Trichophyton rubrum, Aspergillus fumigatus. In addition, compounds 1-4 possessed notable cytotoxcities against human cancer cell lines of HL-60 cells with the IC50 values of below 100 μM. Besides, compounds 1, 2, 4 and 5 showed strong cytotoxities on the LOVO cell line with the IC50 values were lower than 100 μM. In conclusion, our study suggested that endophytic fungi of D. officinale are great potential resources to discover novel agents for preventing or treating pathogens and tumors.

Seasonal variation of bacterial endophytes in urban trees

PubMed Central

Shen, Shu Yi; Fulthorpe, Roberta

2015-01-01

Bacterial endophytes, non-pathogenic bacteria residing within plants, contribute to the growth and development of plants and their ability to adapt to adverse conditions. In order to fully exploit the capabilities of these bacteria, it is necessary to understand the extent to which endophytic communities vary between species and over time. The endophytes of Acer negundo, Ulmus pumila, and Ulmus parvifolia were sampled over three seasons and analyzed using culture dependent and independent methods (culture on two media, terminal restriction fragment length polymorphism, and tagged pyrosequencing of 16S ribosomal amplicons). The majority of culturable endophytes isolated were Actinobacteria, and all the samples harbored Bacillus, Curtobacterium, Frigoribacterium, Methylobacterium, Paenibacilllus, and Sphingomonas species. Regardless of culture medium used, only the culturable communities obtained in the winter for A. negundo could be distinguished from those of Ulmus spp. In contrast, the nonculturable communities were dominated by Proteobacteria and Actinobacteria, particularly Erwinia, Ralstonia, and Sanguibacter spp. The presence and abundance of various bacterial classes and phyla changed with the changing seasons. Multivariate analysis on the culture independent data revealed significant community differences between the endophytic communities of A. negundo and Ulmus spp., but overall season was the main determinant of endophytic community structure. This study suggests studies on endophytic populations of urban trees should expect to find significant seasonal and species-specific community differences and sampling should proceed accordingly. PMID:26042095

Highly Diverse Endophytic and Soil Fusarium oxysporum Populations Associated with Field-Grown Tomato Plants

PubMed Central

Demers, Jill E.; Gugino, Beth K.

2014-01-01

The diversity and genetic differentiation of populations of Fusarium oxysporum associated with tomato fields, both endophytes obtained from tomato plants and isolates obtained from soil surrounding the sampled plants, were investigated. A total of 609 isolates of F. oxysporum were obtained, 295 isolates from a total of 32 asymptomatic tomato plants in two fields and 314 isolates from eight soil cores sampled from the area surrounding the plants. Included in this total were 112 isolates from the stems of all 32 plants, a niche that has not been previously included in F. oxysporum population genetics studies. Isolates were characterized using the DNA sequence of the translation elongation factor 1α gene. A diverse population of 26 sequence types was found, although two sequence types represented nearly two-thirds of the isolates studied. The sequence types were placed in different phylogenetic clades within F. oxysporum, and endophytic isolates were not monophyletic. Multiple sequence types were found in all plants, with an average of 4.2 per plant. The population compositions differed between the two fields but not between soil samples within each field. A certain degree of differentiation was observed between populations associated with different tomato cultivars, suggesting that the host genotype may affect the composition of plant-associated F. oxysporum populations. No clear patterns of genetic differentiation were observed between endophyte populations and soil populations, suggesting a lack of specialization of endophytic isolates. PMID:25304514

A glimpse of the endophytic bacterial diversity in roots of blackberry plants (Rubus fruticosus).

PubMed

Contreras, M; Loeza, P D; Villegas, J; Farias, R; Santoyo, G

2016-09-16

The aim of this study was to explore the diversity of culturable bacterial communities residing in blackberry plants (Rubus fruticosus). Bacterial endophytes were isolated from plant roots, and their 16S rDNA sequences were amplified and sequenced. Our results show that the roots of R. fruticosus exhibit low colony forming units of bacterial endophytes per gram of fresh tissue (6 x 10 2 ± 0.5 x 10 2 ). We identified 41 endophytic bacterial species in R. fruticosus by BLAST homology search and a subsequent phylogenetic analysis, belonging to the classes Actinobacteria, Bacilli, Alfaproteobacteria, Betaproteobacteria, and Gammaproteobacteria. Predominantly, genera belonging the Proteobacteria (Burkholderia, 29.4%; Herbaspirillum, 10.7%; Pseudomonas, 4.9%; and Dyella, 3.9%), Firmicutes (Bacillus, 42.1%), and Actinobacteria (two isolates showing high identity with the Streptomyces genus, 1.9%) divisions were identified. Fifty percent of the bacterial endophytes produced the phytohormone indole-acetic acid (IAA), eleven of which exhibited higher IAA production (>5.8 mg/mL) compared to the plant growth-promoting strain, Pseudomonas fluorescens UM270. Additionally, the endophytic isolates exhibited protease activity (22%), produced siderophores (26.4%), and demonstrated antagonistic action (>50% inhibition of mycelial growth) against the grey mold phytopathogen Botrytis cinerea (3.9%). These results suggested that field-grown R. fruticosus plants contain bacterial endophytes within their tissues with the potential to promote plant growth and display antagonism towards plant pathogens.

Plant volatile organic compounds associated with fungal endophyte seed treatment of cotton

USDA-ARS?s Scientific Manuscript database

Fungal endophytes are asymptomatic endosymbionts of plants that can confer benefits to the host plant such as drought tolerance and herbivore resistance. We isolated naturally occurring fungal endophytes from field-grown cotton, cultured them in lab, and used their prepared biomass in seed treatmen...

Biology of Frankia strains, actinomycete symbionts of actinorhizal plants.

PubMed Central

Benson, D R; Silvester, W B

1993-01-01

Frankia strains are N2-fixing actinomycetes whose isolation and cultivation were first reported in 1978. They induce N2-fixing root nodules on diverse nonleguminous (actinorhizal) plants that are important in ecological successions and in land reclamation and remediation. The genus Frankia encompasses a diverse group of soil actinomycetes that have in common the formation of multilocular sporangia, filamentous growth, and nitrogenase-containing vesicles enveloped in multilaminated lipid envelopes. The relatively constant morphology of vesicles in culture is modified by plant interactions in symbiosis to give a diverse array of vesicles shapes. Recent studies of the genetics and molecular genetics of these organisms have begun to provide new insights into higher-plant-bacterium interactions that lead to productive N2-fixing symbioses. Sufficient information about the relationship of Frankia strains to other bacteria, and to each other, is now available to warrant the creation of some species based on phenotypic and genetic criteria. Images PMID:8336669

Isolation and Characterization of “Terrein” an Antimicrobial and Antitumor Compound from Endophytic Fungus Aspergillus terreus (JAS-2) Associated from Achyranthus aspera Varanasi, India

PubMed Central

Goutam, Jyoti; Sharma, Gunjan; Tiwari, Vinod K.; Mishra, Amrita; Kharwar, Ravindra N.; Ramaraj, Vijayakumar; Koch, Biplob

2017-01-01

The present study aimed at characterizing biological potentials of endophyte Aspergillus terreus JAS-2 isolated from Achyranthus aspera. Crude extracted from endophytic fungus JAS-2 was purified and chemically characterized by chromatographic and spectroscopic studies respectively. Spectral assignment of NMR (nuclear magnetic resonance) data, 1H proton and 13C carbon analysis along with FTIR data elucidated the structure of compound as 4,5-Dihydroxy-3-(1-propenyl)-2-cyclopenten-1-one. After purification and identification a set of experiment was conducted to explore efficacy of compound. Results revealed that on accessing the antifungal activity of compound, growth diameter of tested phytopathogenic fungi was reduced to 50% at higher concentration taken (10 μgμl−1). Compound exhibited in-vitro bacterial cell inhibition at 20 μgml−1 concentration along with moderate antioxidant behavior. Evaluation of anticancer activity against human lung cancer cell line (A-549) exhibited its IC50 value to be 121.9 ± 4.821 μgml−1. Further cell cycle phase distribution were analyzed on the basis of DNA content and evaluated by FACS (Fluorescence Activated Cell Sorting) and it was revealed that at 150 μgml−1 of compound maximum cells were found in sub G1 phase which represents apoptotic dead cells. Terrein (4, 5-Dihydroxy-3-(1-propenyl)-2-cyclopenten-1-one) a multi-potential was isolated from endophytic fungus JAS-2, from well recognized medicinal herb A. aspera. To best of our knowledge, this is the first report of “Terrein” from endophytic derived fungus. This compound had also exhibited anticancer and antifungal activity against human lung cancer cell line A-549 and Bipolaris sorokiniana respectively which is causal organism of many plants disease. Hence endophytes are serving as alternative sources of drug molecules. PMID:28790982

Fungal endophytes of turmeric (Curcuma longa L.) and their biocontrol potential against pathogens Pythium aphanidermatum and Rhizoctonia solani.

PubMed

Vinayarani, G; Prakash, H S

2018-03-14

Endophytic fungi have been isolated from the healthy turmeric (Curcuma longa L.) rhizomes from South India. Thirty-one endophytes were identified based on morphological and ITS-rDNA sequence analysis. The isolated endophytes were screened for antagonistic activity against Pythium aphanidermatum (Edson) Fitzp., and Rhizoctonia solani Kuhn., causing rhizome rot and leaf blight diseases in turmeric respectively. Results revealed that only six endophytes showed > 70% suppression of test pathogens in antagonistic dual culture assays. The endophyte T. harzianum TharDOB-31 showed significant in vitro mycelial growth inhibition of P. aphanidermatum (76.0%) and R. solani (76.9%) when tested by dual culture method. The SEM studies of interaction zone showed morphological abnormalities like parasitism, shriveling, breakage and lysis of hyphae of the pathogens by endophyte TharDOB-31. Selected endophytic isolates recorded multiple plant growth promoting traits in in vitro studies. The rhizome bacterization followed by soil application of endophyte TharDOB-31 showed lowest Percent Disease Incidence of rhizome rot and leaf blight, 13.8 and 11.6% respectively. The treatment of TharDOB-31 exhibited significant increase in plant height (85 cm) and fresh rhizome yield/plant (425 g) in comparison with untreated control under greenhouse condition. The confocal microscopy validates the colonization of the TharDOB-31 in turmeric rhizomes. The secondary metabolites in ethyl acetate extract of TharDOB-31 were found to contain higher number of antifungal compounds by high resolution liquid chromatograph mass spectrometer analysis. Thereby, endophyte T. harzianum isolate can be exploited as a potential biocontrol agent for suppressing rhizome rot and leaf blight diseases in turmeric.

Endophytic fungal communities of Polygonum acuminatum and Aeschynomene fluminensis are influenced by soil mercury contamination

PubMed Central

Mello, Ivani Souza; Vendruscullo, Suzana Junges; da Silva, Gilvan Ferreira; da Cunha, Cátia Nunes; White, James Francis

2017-01-01

The endophytic fungal communities of Polygonum acuminatum and Aeschynomene fluminensis were examined with respect to soil mercury (Hg) contamination. Plants were collected in places with and without Hg+2 for isolation and identification of their endophytic root fungi. We evaluated frequency of colonization, number of isolates and richness, indices of diversity and similarity, functional traits (hydrolytic enzymes, siderophores, indoleacetic acid, antibiosis and metal tolerance) and growth promotion of Aeschynomene fluminensis inoculated with endophytic fungi on soil with mercury. The frequency of colonization, structure and community function, as well as the abundant distribution of taxa of endophytic fungi were influenced by mercury contamination, with higher endophytic fungi in hosts in soil with mercury. The presence or absence of mercury in the soil changes the profile of the functional characteristics of the endophytic fungal community. On the other hand, tolerance of lineages to multiple metals is not associated with contamination. A. fluminensis depends on its endophytic fungi, since plants free of endophytic fungi grew less than expected due to mercury toxicity. In contrast plants containing certain endophytic fungi showed good growth in soil containing mercury, even exceeding growth of plants cultivated in soil without mercury. The data obtained confirm the hypothesis that soil contamination by mercury alters community structure of root endophytic fungi in terms of composition, abundance and species richness. The inoculation of A. fluminensis with certain strains of stress tolerant endophytic fungi contribute to colonization and establishment of the host and may be used in processes that aim to improve phytoremediation of soils with toxic concentrations of mercury. PMID:28742846

Endophytic fungal communities of Polygonum acuminatum and Aeschynomene fluminensis are influenced by soil mercury contamination.

PubMed

Pietro-Souza, William; Mello, Ivani Souza; Vendruscullo, Suzana Junges; Silva, Gilvan Ferreira da; Cunha, Cátia Nunes da; White, James Francis; Soares, Marcos Antônio

2017-01-01

The endophytic fungal communities of Polygonum acuminatum and Aeschynomene fluminensis were examined with respect to soil mercury (Hg) contamination. Plants were collected in places with and without Hg+2 for isolation and identification of their endophytic root fungi. We evaluated frequency of colonization, number of isolates and richness, indices of diversity and similarity, functional traits (hydrolytic enzymes, siderophores, indoleacetic acid, antibiosis and metal tolerance) and growth promotion of Aeschynomene fluminensis inoculated with endophytic fungi on soil with mercury. The frequency of colonization, structure and community function, as well as the abundant distribution of taxa of endophytic fungi were influenced by mercury contamination, with higher endophytic fungi in hosts in soil with mercury. The presence or absence of mercury in the soil changes the profile of the functional characteristics of the endophytic fungal community. On the other hand, tolerance of lineages to multiple metals is not associated with contamination. A. fluminensis depends on its endophytic fungi, since plants free of endophytic fungi grew less than expected due to mercury toxicity. In contrast plants containing certain endophytic fungi showed good growth in soil containing mercury, even exceeding growth of plants cultivated in soil without mercury. The data obtained confirm the hypothesis that soil contamination by mercury alters community structure of root endophytic fungi in terms of composition, abundance and species richness. The inoculation of A. fluminensis with certain strains of stress tolerant endophytic fungi contribute to colonization and establishment of the host and may be used in processes that aim to improve phytoremediation of soils with toxic concentrations of mercury.

The contribution of endophytic bacteria to Albizia lebbeck-mediated phytoremediation of tannery effluent contaminated soil.

PubMed

Manikandan, Muthu; Kannan, Vijayaraghavan; Mendoza, Ordetta Hannah; Kanimozhi, Mahalingam; Chun, Sechul; Pašić, Lejla

2016-01-01

Toxicity of chromium often impairs the remediation capacity of plants used in phytoremediation of polluted soils. In this study, we have identified Albizia lebbeck as a prospective chromium hyperaccumulator and examined cultivable diversity of endophytes present in chromium-treated and control saplings. High numbers (22-100%) of endophytic bacteria, isolated from root, stem, and leaf tissues, could tolerate elevated (1-3 mM) concentrations of K2CrO7. 16S rRNA gene sequence-based phylogenetic analysis showed that the 118 isolates obtained comprised of 17 operational taxonomic units affiliated with the proteobacterial genera Rhizobium (18%), Marinomonas (1%), Pseudomonas (16%), and Xanthomonas (7%) but also with members of Firmicutes genera, such as Bacillus (35%) and Salinococcus (3%). The novel isolates belonging to Salinococcus and Bacillus could tolerate high K2CrO7 concentrations (3 mM) and also showed elevated activity of chromate reductase. In addition, majority (%) of the endophytic isolates also showed production of indole-3-acetic acid. Taken together, our results indicate that the innate endophytic bacterial community assists plants in reducing heavy metal toxicity.

Evidence of heat-resistant microorganisms with a special emphasis on filamentous Actinomycetes in hyper-arid soils of Gandom Beryan area, Lut Desert, Iran.

PubMed

Mazkour, Somaye; Hosseinzadeh, Saeid; Shekarforoush, Seyed Shahram

2017-12-01

In the present study, the Lut Desert, Iran was chosen as one of the hottest places in the world (with the recorded temperature of 70.7°C during 2003-2009) to find out whether any heat-resistant microorganisms were present in the soil. The samples were collected from surface and depth of three identified places of Gandom Beryan in the Lut Desert. Chemical analysis and enumeration of the total bacteria, yeasts and molds were performed. Four selective culture media were employed to isolate the filamentous actinomycetes. The suspected colonies were further confirmed using PCR assay. Then the culture cell-free-supernatants (CFS) of isolates were used to investigate their antimicrobial activity against Staphylococcus aureus, Bacillus cereus, Salmonella Typhimurium and Escherichia coli . Chemical analysis of the samples included moisture (0.2-0.9%), ash (85-91%), organic materials (8.3-14.4%), pH (7.59-9.40) and electrical conductivity (380-2000 μS/cm). The number of isolated bacteria and molds varied from 0-20 to 0-40 CFU/g, respectively. Number of Actinomycetes isolated from the soil samples were between 0-12.2 CFU/g. Nine isolated colonies were identified as filamentous Actinomycetes. To determine the possibility of antimicrobial peptides, the CFS (cell-free supernatant) was firstly neutralized by NaOH and catalase. The results showed that none of the CFS of the isolates was effective against E. coli, S. Typhimurium and S. aureus , while the maximum inhibitory effect was investigated on B. cereus , which was 33.1%±1.19% (mean ± SD). The results of the current study imply the presence of rare heat-resistant microorganisms in the soil of Gandom Beryan which may be further used to find out more about the function of natural bioactive compounds. Actinomycetes, as extremophile microorganisms, have shown the greatest genomic and metabolic diversity, as such the discovery of the novel Actinomycetes as a source of secondary metabolites is essential.

Widespread and Persistent Populations of a Major New Marine Actinomycete Taxon in Ocean Sediments

PubMed Central

Mincer, Tracy J.; Jensen, Paul R.; Kauffman, Christopher A.; Fenical, William

2002-01-01

A major taxon of obligate marine bacteria within the order Actinomycetales has been discovered from ocean sediments. Populations of these bacteria (designated MAR 1) are persistent and widespread, spanning at least three distinct ocean systems. In this study, 212 actinomycete isolates possessing MAR 1 morphologies were examined and all but two displayed an obligate requirement of seawater for growth. Forty-five of these isolates, representing all observed seawater-requiring morphotypes, were partially sequenced and found to share characteristic small-subunit rRNA signature nucleotides between positions 207 and 468 (Escherichia coli numbering). Phylogenetic characterization of seven representative isolates based on almost complete sequences of genes encoding 16S rRNA (16S ribosomal DNA) yielded a monophyletic clade within the family Micromonosporaceae and suggests novelty at the genus level. This is the first evidence for the existence of widespread populations of obligate marine actinomycetes. Organic extracts from cultured members of this new group exhibit remarkable biological activity, suggesting that they represent a prolific resource for biotechnological applications. PMID:12324350

[Isolation and identification of berberine from endophytic fungi HL-Y-3].

PubMed

Zhang, Feng-Hua; Xiang, Jian-Hui; Cui, Wen-Xia; Yu, Jiang; Wang, Yan; Li, Qin-Fan

2016-08-01

The endophytic fungi HL-Y-3, which was isolated from the healthy leaves of Coptis chinensis, produced berberine when grown in the PDA culture medium. The presence of berberine was confirmed by the chromatographic and spectroscopic analyses. The yield of berberine was recorded as 9.313 μg•g⁻¹ by HPLC. The strain HL-Y-3 was identified as Alternaria sp.by morphological observation and 5.8S rDNA-ITS sequence analysis.The separation and purification of constituents were performed by PTLC. The mass spectrometry (MS) of the analyte was shown to be identical with authentic berberine.Further analysis with nuclear magnetic resonance (NMR) spectroscopy to showed that the chemical structure of the fungal berberine was identical with authentic berberine. The research provided new resources for the utilization of berberine. Copyright© by the Chinese Pharmaceutical Association.

Sexual and asexual states of some endophytic Phialocephala species of Picea.

PubMed

Tanney, Joey B; Douglas, Brian; Seifert, Keith A

2016-01-01

Unidentified DNA sequences in isolation-based or culture-free studies of conifer endophytes are a persistent problem that requires a field approach to resolve. An investigation of foliar endophytes of Picea glauca, P. mariana, P. rubens and Pinus strobus in eastern Canada, using a combined field, morphological, cultural and DNA sequencing approach, resulted in the frequent isolation of Phialocephala spp. and the first verified discovery of their mollisia-like sexual states in the field. Phialocephala scopiformis and Ph. piceae were the most frequent species isolated as endophytes from healthy conifer needles. Corresponding Mollisia or mollisioid sexual states for Ph. scopiformis, Ph. piceae and several undescribed species in a clade containing Ph. dimorphospora were collected in the sampling area and characterized by analysis of the nuc internal transcribed spacer rDNA (ITS) and gene for the largest subunit of RNA polymerase II (RPB1) loci. Four novel species and one new combination in a clade containing Ph. dimorphospora, the type of Phialocephala, are presented, accompanied by descriptions of apothecia and previously undocumented synanamorphs. An epitype culture and corresponding reference sequences for Phialocephala dimorphospora are proposed. The resulting ITS barcodes linked with robust taxonomic species concepts are an important resource for future research on forest ecosystems and endophytes. © 2016 by The Mycological Society of America.

Leishmanicidal Metabolites from Cochliobolus sp., an Endophytic Fungus Isolated from Piptadenia adiantoides (Fabaceae)

PubMed Central

Campos, Fernanda Fraga; Rosa, Luiz Henrique; Cota, Betania Barros; Caligiorne, Rachel Basques; Teles Rabello, Ana Lúcia; Alves, Tânia Maria Almeida; Rosa, Carlos Augusto; Zani, Carlos Leomar

2008-01-01

Protozoan parasites belonging to genera Leishmania and Trypanosoma are the etiological agents of severe neglected tropical diseases (NTDs) that cause enormous social and economic impact in many countries of tropical and sub-tropical areas of the world. In our screening program for new drug leads from natural sources, we found that the crude extract of the endophytic fungus Cochliobolus sp. (UFMGCB-555) could kill 90% of the amastigote-like forms of Leishmania amazonensis and inhibit by 100% Ellman's reagent reduction in the trypanothione reductase (TryR) assay, when tested at 20 µg mL−1. UFMGCB-555 was isolated from the plant Piptadenia adiantoides J.F. Macbr (Fabaceae) and identified based on the sequence of the internally transcribed spacer (ITS) regions of its ribosomal DNA. The chromatographic fractionation of the extract was guided by the TryR assay and resulted in the isolation of cochlioquinone A and isocochlioquinone A. Both compounds were active in the assay with L. amazonensis, disclosing EC50 values (effective concentrations required to kill 50% of the parasite) of 1.7 µM (95% confidence interval = 1.6 to 1.9 µM) and 4.1 µM (95% confidence interval = 3.6 to 4.7 µM), respectively. These compounds were not active against three human cancer cell lines (MCF-7, TK-10, and UACC-62), indicating some degree of selectivity towards the parasites. These results suggest that cochlioquinones are attractive lead compounds that deserve further investigation aiming at developing new drugs to treat leishmaniasis. The findings also reinforce the role of endophytic fungi as an important source of compounds with potential to enter the pipeline for drug development against NTDs. PMID:19079599

Preferential Association of Endophytic Bradyrhizobia with Different Rice Cultivars and Its Implications for Rice Endophyte Evolution

PubMed Central

Piromyou, Pongdet; Greetatorn, Teerana; Teamtisong, Kamonluck; Okubo, Takashi; Shinoda, Ryo; Nuntakij, Achara; Tittabutr, Panlada; Boonkerd, Nantakorn

2015-01-01

Plant colonization by bradyrhizobia is found not only in leguminous plants but also in nonleguminous species such as rice. To understand the evolution of the endophytic symbiosis of bradyrhizobia, the effect of the ecosystems of rice plantations on their associations was investigated. Samples were collected from various rice (Oryza sativa) tissues and crop rotational systems. The rice endophytic bradyrhizobia were isolated on the basis of oligotrophic properties, selective medium, and nodulation on siratro (Macroptilium atropurpureum). Six bradyrhizobial strains were obtained exclusively from rice grown in a crop rotational system. The isolates were separated into photosynthetic bradyrhizobia (PB) and nonphotosynthetic bradyrhizobia (non-PB). Thai bradyrhizobial strains promoted rice growth of Thai rice cultivars better than the Japanese bradyrhizobial strains. This implies that the rice cultivars possess characteristics that govern rice-bacterium associations. To examine whether leguminous plants in a rice plantation system support the persistence of rice endophytic bradyrhizobia, isolates were tested for legume nodulation. All PB strains formed symbioses with Aeschynomene indica and Aeschynomene evenia. On the other hand, non-PB strains were able to nodulate Aeschynomene americana, Vigna radiata, and M. atropurpureum but unable to nodulate either A. indica or A. evenia. Interestingly, the nodABC genes of all of these bradyrhizobial strains seem to exhibit low levels of similarity to those of Bradyrhizobium diazoefficiens USDA110 and Bradyrhizobium sp. strain ORS285. From these results, we discuss the evolution of the plant-bradyrhizobium association, including nonlegumes, in terms of photosynthetic lifestyle and nod-independent interactions. PMID:25710371

Alfalfa endophytes as novel sources of antimicrobial compounds that inhibit the growth of human and plant pathogens

USDA-ARS?s Scientific Manuscript database

Fungal endophytes may contribute to plant health and disease protection, yet little is known about their various roles in alfalfa. Also, endophytes from several plant species produce novel antimicrobial compounds that may be useful clinically. We isolated endophytic fungi from over 50 samples from s...

Genetic characterization of uncultured fungal endophytes from Bouteloua eriopoda and Atriplex canescens

Treesearch

Mary E. Lucero; Jerry R. Barrow; Ruth Sedillo; Pedro Osuna-Avila; Isaac Reyes-Vera

2008-01-01

Obligate fungal endophytes form cryptic communities in vascular plants that can defy detection and isolation by microscopic examination of reproductive structures. Molecular detection by PCR amplification of fungal DNA sequences alone is insufficient, since target endophyte sequences are unknown and difficult to distinguish from sequences already characterized as plant...

Arsenic transformation and plant growth promotion characteristics of As-resistant endophytic bacteria from As-hyperaccumulator Pteris vittata.

PubMed

Xu, Jia-Yi; Han, Yong-He; Chen, Yanshan; Zhu, Ling-Jia; Ma, Lena Q

2016-02-01

The ability of As-resistant endophytic bacteria in As transformation and plant growth promotion was determined. The endophytes were isolated from As-hyperaccumulator Pteris vittata (PV) after growing for 60 d in a soil containing 200 mg kg(-1) arsenate (AsV). They were isolated in presence of 10 mM AsV from PV roots, stems, and leaflets, representing 4 phyla and 17 genera. All endophytes showed at least one plant growth promoting characteristics including IAA synthesis, siderophore production and P solubilization. The root endophytes had higher P solubilization ability than the leaflet (60.0 vs. 18.3 mg L(-1)). In presence of 10 mM AsV, 6 endophytes had greater growth than the control, suggesting As-stimulated growth. Furthermore, root endophytes were more resistant to AsV while the leaflet endophytes were more tolerant to arsenite (AsIII), which corresponded to the dominant As species in PV tissues. Bacterial As resistance was positively correlated to their ability in AsV reduction but not AsIII oxidation. The roles of those endophytes in promoting plant growth and As resistance in P. vittata warrant further investigation. Published by Elsevier Ltd.

Biological Evaluation of Endophytic Fungus Chaetomium sp. NF15 of Justicia adhatoda L.: A Potential Candidate for Drug Discovery

PubMed Central

Fatima, Nighat; Mukhtar, Usman; Ihsan-Ul-Haq; Ahmed Qazi, Muneer; Jadoon, Muniba; Ahmed, Safia

2016-01-01

Background The endophytes of medicinal plants, such as Justicia adhatoda L., represent a promising and largely underexplored domain that is considered as a repository of biologically active compounds. Objectives The aim of present study was isolation, identification, and biological evaluation of endophytic fungi associated with the J. adhatoda L. plant for the production of antimicrobial, antioxidant, and cytotoxic compounds Materials and Methods Endophytic fungi associated with the J. adhatoda L. plant were isolated from healthy plant parts and taxonomically characterized through morphological, microscopic, and 18S rDNA sequencing methods. The screening for bioactive metabolite production was achieved using ethyl acetate extracts, followed by the optimization of different parameters for maximum production of bioactive metabolites. Crude and partially purified extracts were used to determine the antimicrobial, antioxidant, and cytotoxic potential Results Out of six endophytic fungal isolates, Chaetomium sp. NF15 showed the most promising biological activity and was selected for detailed study. The crude ethyl acetate extract of NF15 isolate after cultivation under optimized culture conditions showed promising antimicrobial activity, with significant inhibition of the clinical isolates of Staphylococcus aureus (87%, n=42), Pseudomonas aeruginosa (> 85%, n = 41), and Candida albicans (62%, n = 24). Conclusions The present study confirms the notion of selecting endophytic fungi of medicinal plant Justicia for the bioassay-guided isolation of its bioactive compounds, and demonstrates that endophytic fungus Chaetomium sp. NF15 could be a potential source of bioactive metabolites PMID:27635208

Endophytic fungi associated with Sudanese medicinal plants show cytotoxic and antibiotic potential.

PubMed

Khiralla, Afra; Mohamed, Ietidal E; Tzanova, Tzvetomira; Schohn, Hervé; Slezack-Deschaumes, Sophie; Hehn, Alain; André, Philippe; Carre, Gaëlle; Spina, Rosella; Lobstein, Annelise; Yagi, Sakina; Laurain-Mattar, Dominique

2016-06-01

In this study, we isolated 15 endophytic fungi from five Sudanese medicinal plants. Each fungal endophytic strain was identified by sequencing of internal transcribed spacer (ITS) regions of rDNA. Ethyl acetate extracts were prepared from each endophyte cultivated in vitro and tested for their respective antibacterial activities and antiproliferative activities against human cancer cells. Antibacterial screening was carried out against two bacterial strains: Gram-negative Escherichia coli and Gram-positive methicillin-resistant Staphylococcus aureus, by the broth dilution method. Cell viability was evaluated by the MTT procedure after exposure of MCF7 breast cancer cells and HT29 or HCT116 human colon adenocarcinoma cells to each endophytic extract. Of interest, Byssochlamys spectabilis isolated from Euphorbia prostata showed cytotoxicity (IC50 = 1.51 ± 0.2 μg mL(-1)) against MCF7 cells, but had a low effect against HT29 or HCT116 cells (IC50 > 20 μg mL(-1)). Cladosporium cladosporioides 2, isolated from Vernonia amygdalina leaves, showed antiproliferative activities against MCF7 cells (IC50 = 10.5 ± 1.5 μg mL(-1)) only. On the other hand, B. spectabilis and Alternaria sp. extract had antibacterial activities against the S. aureus strain. The findings of this work revealed that endophytic fungi associated with medicinal plants from Sudan could be considered as an attractive source of new therapeutic compounds. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Endophytic bacteria from Piper tuberculatum Jacq.: isolation, molecular characterization, and in vitro screening for the control of Fusarium solani f. sp piperis, the causal agent of root rot disease in black pepper (Piper nigrum L.).

PubMed

Nascimento, S B; Lima, A M; Borges, B N; de Souza, C R B

2015-07-06

Endophytic bacteria have been found to colonize internal tissues in many different plants, where they can have several beneficial effects, including defense against pathogens. In this study, we aimed to identify endophytic bacteria associated with roots of the tropical piperaceae Piper tuberculatum, which is known for its resistance to infection by Fusarium solani f. sp piperis, the causal agent of black pepper (Piper nigrum) root rot disease in the Amazon region. Based on 16S rRNA gene sequence analysis, we isolated endophytes belonging to 13 genera: Bacillus, Paenibacillus, Pseudomonas, Enterobacter, Rhizobium, Sinorhizobium, Agrobacterium, Ralstonia, Serratia, Cupriavidus, Mitsuaria, Pantoea, and Staphylococcus. The results showed that 56.52% of isolates were associated with the phylum Proteobacteria, which comprised α, β, and γ classes. Other bacteria were related to the phylum Firmicutes, including Bacillus, which was the most abundant genus among all isolates. Antagonistic assays revealed that Pt12 and Pt13 isolates, identified as Pseudomonas putida and Pseudomonas sp, respectively, were able to inhibit F. solani f. sp piperis growth in vitro. We describe, for the first time, the molecular identification of 23 endophytic bacteria from P. tuberculatum, among which two Pseudomonas species have the potential to control the pathogen responsible for root rot disease in black pepper in the Amazon region.

Isolation of a rice endophytic bacterium, Pantoea sp. Sd-1, with ligninolytic activity and characterization of its rice straw degradation ability.

PubMed

Xiong, X Q; Liao, H D; Ma, J S; Liu, X M; Zhang, L Y; Shi, X W; Yang, X L; Lu, X N; Zhu, Y H

2014-02-01

This study focused on an endophytic bacterial strain, Pantoea sp. Sd-1, which can be used to degrade lignin and rice straw. This strain was isolated from rice seeds by an optimized surface sterilization method. Pantoea sp. Sd-1 showed exceptional ability to degrade rice straw and lignin. In rice straw or kraft lignin-containing medium supplemented with 1% glucose and 0.5% peptone, Pantoea sp. Sd-1 effectively reduced the rice straw mass weight by 54.5% after 6 days of treatment. The strain was also capable of reducing the lignin colour (52.4%) and content (69.1%) after 4 days of incubation. The findings suggested that the rice endophytic bacterium Pantoea sp. Sd-1 could be applied for the degradation of lignocellulose biomass, such as rice straw. Rice straw, an abundant agricultural by-product in China, is very difficult to degrade because of its high lignin content. Due to the immense environmental adaptability and biochemical versatility of bacteria, endophytic bacteria are useful resources for biodegradation. In this study, we screened for endophytic bacteria capable of biodegrading rice straw and lignin and obtained one strain, Pantoea sp. Sd-1, with suitable characteristics. Sd-1 could be used for degradation of rice straw and lignin, and may play an important role in biodegradation of this agricultural by-product. © 2013 The Society for Applied Microbiology.

Molecular Characterization and Analysis of Antimicrobial Activity of Endophytic Fungi From Medicinal Plants in Saudi Arabia

PubMed Central

Gashgari, Rukaia; Gherbawy, Youssuf; Ameen, Fuad; Alsharari, Salam

2016-01-01

Background: Endophytic fungi, which have been reported in numerous plant species, are important components of the forest community and contribute significantly to the diversity of natural ecosystems. Objectives: The current study aimed to evaluate and characterize, at the molecular level, the diversity and antimicrobial activities of endophytic fungi from medicinal plants in Saudi Arabia. Materials and Methods: Fungi growing on plant segments were isolated and identified based on morphological and molecular characteristics. The isolates were grouped into 35 distinct operational taxonomic units, based on the sequence of the internal transcribed spacer regions in the rRNA gene. The colonization frequency and the dominant fungi percentage of these endophytic fungi were calculated. A dual culture technique was adopted to investigate the antifungal activity of these endophytes. Results: Tamarix nilotica showed the highest endophytic diversity with a relative frequency of 27.27%, followed by Cressa cretica with a relative frequency of 19.27%. The most frequently isolated species was Penicillium chrysogenum with an overall colonization rate of 98.57%. Seven out of 35 endophytic fungi exhibited strong antifungal activity to all plant fungal pathogens tested. P. chrysogenum, Fusarium oxysporum, and F. nygamai exhibited the highest inhibition against the human pathogenic bacteria Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae. Aspergillus sydowii, P. chrysogenum, and Eupenicillium crustaceum showed strong antimicrobial activity against Enterococcus faecalis. Conclusions: The antimicrobial activity of these endophytic microorganisms could be exploited in biotechnology, medicine, and agriculture. PMID:27099679

Endophytes from medicinal plants and their potential for producing indole acetic acid, improving seed germination and mitigating oxidative stress* #

PubMed Central

Khan, Abdul Latif; Gilani, Syed Abdullah; Waqas, Muhammad; Al-Hosni, Khadija; Al-Khiziri, Salima; Kim, Yoon-Ha; Ali, Liaqat; Kang, Sang-Mo; Asaf, Sajjad; Shahzad, Raheem; Hussain, Javid; Lee, In-Jung; Al-Harrasi, Ahmed

2017-01-01

Medicinal plants have been used by marginal communities to treat various ailments. However, the potential of endophytes within these bio-prospective medicinal plants remains unknown. The present study elucidates the endophytic diversity of medicinal plants (Caralluma acutangula, Rhazya stricta, and Moringa peregrina) and the endophyte role in seed growth and oxidative stress. Various organs of medicinal plants yielded ten endophytes, which were identified as Phoma sp. (6 isolates), Alternaria sp. (2), Bipolaris sp. (1), and Cladosporium sp. (1) based on 18S rDNA sequencing and phylogenetic analysis. The culture filtrates (CFs; 25%, 50%, and 100% concentrations) from these endophytes were tested against the growth of normal and dwarf mutant rice lines. Endophytic CF exhibited dose-dependent growth stimulation and suppression effects. CF (100%) of Phoma sp. significantly increased rice seed germination and growth compared to controls and other endophytes. This growth-promoting effect was due to the presence of indole acetic acid in endophytic CF. The gas chromatography/mass spectrometry (GC/MS) analysis showed the highest indole acetic acid content ((54.31±0.21) µmol/L) in Bipolaris sp. In addition, the isolate of Bipolaris sp. exhibited significantly higher radical scavenging and anti-lipid peroxidation activity than the other isolates. Bipolaris sp. and Phoma sp. also exhibited significantly higher flavonoid and phenolic contents. The medicinal plants exhibited the presence of bio-prospective endophytic strains, which could be used for the improvement of crop growth and the mitigation of oxidative stresses. PMID:28124841

Endophytes from medicinal plants and their potential for producing indole acetic acid, improving seed germination and mitigating oxidative stress.

PubMed

Khan, Abdul Latif; Gilani, Syed Abdullah; Waqas, Muhammad; Al-Hosni, Khadija; Al-Khiziri, Salima; Kim, Yoon-Ha; Ali, Liaqat; Kang, Sang-Mo; Asaf, Sajjad; Shahzad, Raheem; Hussain, Javid; Lee, In-Jung; Al-Harrasi, Ahmed

Medicinal plants have been used by marginal communities to treat various ailments. However, the potential of endophytes within these bio-prospective medicinal plants remains unknown. The present study elucidates the endophytic diversity of medicinal plants (Caralluma acutangula, Rhazya stricta, and Moringa peregrina) and the endophyte role in seed growth and oxidative stress. Various organs of medicinal plants yielded ten endophytes, which were identified as Phoma sp. (6 isolates), Alternaria sp. (2), Bipolaris sp. (1), and Cladosporium sp. (1) based on 18S rDNA sequencing and phylogenetic analysis. The culture filtrates (CFs; 25%, 50%, and 100% concentrations) from these endophytes were tested against the growth of normal and dwarf mutant rice lines. Endophytic CF exhibited dose-dependent growth stimulation and suppression effects. CF (100%) of Phoma sp. significantly increased rice seed germination and growth compared to controls and other endophytes. This growth-promoting effect was due to the presence of indole acetic acid in endophytic CF. The gas chromatography/mass spectrometry (GC/MS) analysis showed the highest indole acetic acid content ((54.31±0.21) µmol/L) in Bipolaris sp. In addition, the isolate of Bipolaris sp. exhibited significantly higher radical scavenging and anti-lipid peroxidation activity than the other isolates. Bipolaris sp. and Phoma sp. also exhibited significantly higher flavonoid and phenolic contents. The medicinal plants exhibited the presence of bio-prospective endophytic strains, which could be used for the improvement of crop growth and the mitigation of oxidative stresses.

Burkholderia vietnamiensis isolated from root tissues of Nipa Palm (Nypa fruticans) in Sarawak, Malaysia, proved to be its major endophytic nitrogen-fixing bacterium.

PubMed

Tang, Sui-Yan; Hara, Shintaro; Melling, Lulie; Goh, Kah-Joo; Hashidoko, Yasuyuki

2010-01-01

Root-associating bacteria of the nipa palm (Nypa fruticans), preferring brackish-water affected mud in Sarawak, Malaysia, were investigated. In a comparison of rhizobacterial microbiota between the nipa and the sago (Metroxylon sagu) palm, it was found that the nipa palm possessed a group of Burkholderia vietnamiensis as its main active nitrogen-fixing endophytic bacterium. Acetylene reduction by the various isolates of B. vietnamiensis was constant (44 to 68 nmol h(-1) in ethylene production rate) in soft gel medium containing 0.2% sucrose as sole carbon source, and the bacterium also showed motility and biofilm-forming capacity. This is the first report of endophytic nitrogen-fixing bacteria from nipa palm.

Streptomyces euryhalinus sp. nov., a new actinomycete isolated from a mangrove forest.

PubMed

Biswas, Kaushik; Choudhury, Jayanta D; Mahansaria, Riddhi; Saha, Malay; Mukherjee, Joydeep

2017-06-01

A Gram-positive, aerobic, non-motile actinomycete (strain MS 3/20 T ) was isolated from the sediment of the Sundarbans mangrove forest in India. On International Streptomyces Project (ISP) medium 2, the isolate produced yellowish brown to red aerial hyphae that carried spiny-surfaced spores in a retinaculum-apertum arrangement. Whole-cell hydrolysate of the strain contained LL-diaminopimelic acid and galactose. Predominant menaquinones were MK-9(H 8 ) and MK-9(H 6 ). Diagnostic polar lipids were glycolipid, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, unidentified phospholipid and unidentified amino lipid. The major fatty acids were anteiso-C 15:0 (17.53%), iso-C 16:0 (23.89%) and anteiso-C 17:0 (10.29%). The strain showed 100% 16S ribosomal RNA (rRNA) gene sequence similarity with Streptomyces variabilis NBRC 12825 T , Streptomyces erythrogriseus LMG 19406 T , Streptomyces griseoincarnatus LMG 19316 T and Streptomyces labedae NBRC 15864 T . However, strain MS 3/20 T could be distinguished from these and seven other closely related species based on low levels of DNA-DNA relatedness (27.2-53.8%), supported by the unique banding pattern obtained from random amplified polymorphic DNA-PCR amplification and the distinctive matrix-assisted laser desorption/ionization-time-of-flight/mass spectrometry (MALDI-TOF/MS) profile of whole-cell proteins acquired for strain MS 3/20 T in comparison with its phylogenetic relatives. Disparate morphological, physiological and chemotaxonomic features, principally growth in NaCl, further corroborated the distinction of strain MS 3/20 T from other phylogenetic relatives. Strain MS 3/20 T is therefore suggested to be a novel species of the genus Streptomyces, for which the name Streptomyces euryhalinus sp. nov. is proposed. The type strain is MS 3/20 T (=CICC 11032 T =DSM 103378 T ).

Streptomyces kronopolitis sp. nov., an actinomycete that produces phoslactomycins isolated from a millipede (Kronopolites svenhedind Verhoeff).

PubMed

Liu, Chongxi; Ye, Lan; Li, Yao; Jiang, Shanwen; Liu, Hui; Yan, Kai; Xiang, Wensheng; Wang, Xiangjing

2016-12-01

A phoslactomycin-producing actinomycete, designated strain NEAU-ML8T, was isolated from a millipede (Kronopolites svenhedind Verhoeff) and characterized using a polyphasic approach. 16S rRNA gene sequence analysis showed that strain NEAU-ML8T belongs to the genus Streptomyces with the highest sequence similarities to Streptomyces lydicus NBRC 13058T (99.39 %) and Streptomyces chattanoogensis DSM 40002T (99.25 %). The maximum-likelihood phylogenetic tree based on 16S rRNA gene sequences showed that the isolate formed a distinct phyletic line with NBRC 13058T and S. chattanoogensis DSM 40002T. This branching pattern was also supported by the tree rconstructed with the neighbour-joining method. A combination of DNA-DNA hybridization experiments and phenotypic tests were carried out between strain NEAU-ML8T and its phylogenetically closely related strains, which further clarified their relatedness and demonstrated that NEAU-ML8T could be distinguished from NBRC 13058T and S. chattanoogensis DSM 40002T. Therefore, it is concluded that strain NEAU-ML8T can be classified as representing a novel species of the genus Streptomyces, for which the name Streptomyces kronopolitis sp. nov. is proposed. The type strain is NEAU-ML8T (=DSM 101986T=CGMCC 4.7323T).

Algicidal effects of a novel marine actinomycete on the toxic dinoflagellate Alexandrium tamarense.

PubMed

Bai, Shijie J; Huang, Liping P; Su, Jianqiang Q; Tian, Yun; Zheng, Tianling L

2011-06-01

A marine actinomycete strain BS01 with algicidal activity to the toxic dinoflagellate, Alexandrium tamarense, was isolated from Xiamen Bay, China. Sequence analysis of 16S rDNA demonstrates that BS01 is closely related to the genus Brevibacterium of Actinomycetales. BS01 exhibited algicidal activity in an indirect manner. Additional organic nutrients, but not algal-derived dissolved organic matter, were necessary for the synthesis of yet unidentified algicidal compounds (molecular weight less than 100), which were heat tolerant, a stable in acidic or alkali conditions, and exhibited a wide range of algicidal activity. This is the first report of an actinomycete algicide to the toxic dinoflagellate A. tamarense. Our results indicate that BS01 could be a potential bio-agent for controlling harmful algal blooms.

Establishing fungal entomopathogens as endophytes: towards endophytic biological control

USDA-ARS?s Scientific Manuscript database

Beauveria basssiana is a fungal entomopathogen with the ability to colonize plants endophytically. As an endophyte, B. bassiana may play a role in protecting plants from herbivory and disease. This protocol demonstrates two inoculation methods to establish B. bassiana endophytically in the common be...

The endophytic bacterium Serratia sp. PW7 degrades pyrene in wheat.

PubMed

Zhu, Xuezhu; Wang, Wanqing; Crowley, David E; Sun, Kai; Hao, Shupeng; Waigi, Michael Gatheru; Gao, Yanzheng

2017-03-01

This research was conducted to isolate polycyclic aromatic hydrocarbon-degrading (PAH-degrading) endophytic bacteria and investigate their potential in protecting plants against PAH contamination. Pyrene-degrading endophytic bacteria were isolated from plants grown in PAH-contaminated soil. Among these endophytic bacteria, strain PW7 (Serratia sp.) isolated from Plantago asiatica was selected to investigate the suppression of pyrene accumulation in Triticum aestivum L. In the in vitro tests, strain PW7 degraded 51.2% of the pyrene in the media within 14 days. The optimal biodegradation conditions were pH 7.0, 30 °C, and MS medium supplemented with additional glucose, maltose, sucrose, and peptones. In the in vivo tests, strain PW7 successfully colonized the roots and shoots of inoculated (E + ) wheat plants, and its colonization decreased pyrene accumulation and pyrene transportation from roots to shoots. Remarkably, the concentration of pyrene in shoots decreased much more than that in roots, suggesting that strain PW7 has the potential for protecting wheat against pyrene contamination and mitigating the threat of pyrene to human health via food consumption.

Bacterial endophytes enhance competition by invasive plants.

PubMed

Rout, Marnie E; Chrzanowski, Thomas H; Westlie, Tara K; DeLuca, Thomas H; Callaway, Ragan M; Holben, William E

2013-09-01

Invasive plants can alter soil microbial communities and profoundly alter ecosystem processes. In the invasive grass Sorghum halepense, these disruptions are consequences of rhizome-associated bacterial endophytes. We describe the effects of N2-fixing bacterial strains from S. halepense (Rout and Chrzanowski, 2009) on plant growth and show that bacteria interact with the plant to alter soil nutrient cycles, enabling persistence of the invasive. • We assessed fluxes in soil nutrients for ∼4 yr across a site invaded by S. halepense. We assayed the N2-fixing bacteria in vitro for phosphate solubilization, iron chelation, and production of the plant-growth hormone indole-3-acetic acid (IAA). We assessed the plant's ability to recruit bacterial partners from substrates and vertically transmit endophytes to seeds and used an antibiotic approach to inhibit bacterial activity in planta and assess microbial contributions to plant growth. • We found persistent alterations to eight biogeochemical cycles (including nitrogen, phosphorus, and iron) in soils invaded by S. halepense. In this context, three bacterial isolates solubilized phosphate, and all produced iron siderophores and IAA in vitro. In growth chamber experiments, bacteria were transmitted vertically, and molecular analysis of bacterial community fingerprints from rhizomes indicated that endophytes are also horizontally recruited. Inhibiting bacterial activity with antibiotics resulted in significant declines in plant growth rate and biomass, with pronounced rhizome reductions. • This work suggests a major role of endophytes on growth and resource allocation of an invasive plant. Indeed, bacterial isolate physiology is correlated with invader effects on biogeochemical cycles of nitrogen, phosphate, and iron.

Production of Gentisyl Alcohol from Phoma herbarum Endophytic in Curcuma longa L. and Its Antagonistic Activity Towards Leaf Spot Pathogen Colletotrichum gloeosporioides.

PubMed

Gupta, Suruchi; Kaul, Sanjana; Singh, Baljinder; Vishwakarma, Ram A; Dhar, Manoj K

2016-11-01

Endophytes from medicinal plants represent a potential source of bioactive compounds. During the present investigation, fungal endophytes were isolated from turmeric (Curcuma longa), an important medicinal plant. A total of 207 endophytic fungal isolates were obtained from the rhizome of C. longa L. They were grouped into seven genera based on morphological and molecular data. The fungal endophytes of C. longa were evaluated for antifungal activity against Colletotrichum gloeosporioides, the causal organism of leaf spot of turmeric. The disease is a major cause for economic loss in turmeric cultivation. Endophytic Phoma herbarum showed significant activity against C. gloeosporioides and was therefore selected for further studies. A compound gentisyl alcohol was isolated from P. herbarum which showed effective antagonism against C. gloeosporioides. The organism could therefore be used as a biocontrol agent against C. gloeosporioides.

Streptomyces castaneus sp. nov., a novel actinomycete isolated from the rhizosphere of Peucedanum praeruptorum Dunn.

PubMed

Zhou, Shuyu; Li, Zhilei; Bai, Lu; Yan, Kai; Zhao, Junwei; Lu, Chang; Liu, Chongxi; Wang, Xiangjing; Xiang, Wensheng

2017-01-01

During an investigation of microbial diversity in medicinal herbs, a novel actinomycete, strain NEAU-QHHV11 T was isolated from the rhizosphere of Peucedanum praeruptorum Dunn collected from Xianglu Mountain in Heilongjiang Province, northeast China and characterized using a polyphasic approach. The organism was found to have typical characteristics of the genus Streptomyces. Phylogenetic analysis based on 16S rRNA gene sequence also indicated that strain NEAU-QHHV11 T belongs to the genus Streptomyces and was most closely related to Streptomyces graminilatus NBRC 108882 T (98.7 % sequence similarity) and Streptomyces turgidiscabies NBRC 16080 T (98.7 % sequence similarity). The results of DNA-DNA hybridization and some phenotypic characteristics indicated that strain NEAU-QHHV11 T could be distinguished from its close phylogenetic relatives. Thus, strain NEAU-QHHV11 T represents a novel species of the genus Streptomyces, for which the name Streptomyces castaneus sp. nov. is proposed. The type strain is NEAU-QHHV11 T (=CGMCC 4.7235 T  = DSM 100520 T ).

Pervasive Effects of Wildfire on Foliar Endophyte Communities in Montane Forest Trees.

PubMed

Huang, Yu-Ling; Devan, M M Nandi; U'Ren, Jana M; Furr, Susan H; Arnold, A Elizabeth

2016-02-01

Plants in all terrestrial ecosystems form symbioses with endophytic fungi that inhabit their healthy tissues. How these foliar endophytes respond to wildfires has not been studied previously, but is important given the increasing frequency and intensity of severe wildfires in many ecosystems, and because endophytes can influence plant growth and responses to stress. The goal of this study was to examine effects of severe wildfires on endophyte communities in forest trees, with a focus on traditionally fire-dominated, montane ecosystems in the southwestern USA. We evaluated the abundance, diversity, and composition of endophytes in foliage of Juniperus deppeana (Cupressaceae) and Quercus spp. (Fagaceae) collected contemporaneously from areas affected by recent wildfire and paired areas not affected by recent fire. Study sites spanned four mountain ranges in central and southern Arizona. Our results revealed significant effects of fires on endophyte communities, including decreases in isolation frequency, increases in diversity, and shifts in community structure and taxonomic composition among endophytes of trees affected by recent fires. Responses to fire were similar in endophytes of each host in these fire-dominated ecosystems and reflect regional fire-return intervals, with endophytes after fire representing subsets of the regional mycoflora. Together, these findings contribute to an emerging perspective on the responses of diverse communities to severe fire, and highlight the importance of considering fire history when estimating endophyte diversity and community structure for focal biomes.

Fungal endophytes in aboveground tissues of desert plants: infrequent in culture, but highly diverse and distinctive symbionts.

PubMed

Massimo, Nicholas C; Nandi Devan, M M; Arendt, Kayla R; Wilch, Margaret H; Riddle, Jakob M; Furr, Susan H; Steen, Cole; U'Ren, Jana M; Sandberg, Dustin C; Arnold, A Elizabeth

2015-07-01

In hot deserts, plants cope with aridity, high temperatures, and nutrient-poor soils with morphological and biochemical adaptations that encompass intimate microbial symbioses. Whereas the root microbiomes of arid-land plants have received increasing attention, factors influencing assemblages of symbionts in aboveground tissues have not been evaluated for many woody plants that flourish in desert environments. We evaluated the diversity, host affiliations, and distributions of endophytic fungi associated with photosynthetic tissues of desert trees and shrubs, focusing on nonsucculent woody plants in the species-rich Sonoran Desert. To inform our strength of inference, we evaluated the effects of two different nutrient media, incubation temperatures, and collection seasons on the apparent structure of endophyte assemblages. Analysis of >22,000 tissue segments revealed that endophytes were isolated four times more frequently from photosynthetic stems than leaves. Isolation frequency was lower than expected given the latitude of the study region and varied among species a function of sampling site and abiotic factors. However, endophytes were very species-rich and phylogenetically diverse, consistent with less arid sites of a similar latitudinal position. Community composition differed among host species, but not as a function of tissue type, sampling site, sampling month, or exposure. Estimates of abundance, diversity, and composition were not influenced by isolation medium or incubation temperature. Phylogenetic analyses of the most commonly isolated genus (Preussia) revealed multiple evolutionary origins of desert-plant endophytism and little phylogenetic structure with regard to seasonality, tissue preference, or optimal temperatures and nutrients for growth in vitro. Together, these results provide insight into endophytic symbioses in desert-plant communities and can be used to optimize strategies for capturing endophyte biodiversity at regional scales.

The local environment determines the assembly of root endophytic fungi at a continental scale.

PubMed

Glynou, Kyriaki; Ali, Tahir; Buch, Ann-Katrin; Haghi Kia, Sevda; Ploch, Sebastian; Xia, Xiaojuan; Çelik, Ali; Thines, Marco; Maciá-Vicente, Jose G

2016-09-01

Root endophytic fungi are found in a great variety of plants and ecosystems, but the ecological drivers of their biogeographic distribution are poorly understood. Here, we investigate the occurrence of root endophytes in the non-mycorrhizal plant genus Microthlaspi, and the effect of environmental factors and geographic distance in structuring their communities at a continental scale. We sampled 52 plant populations across the northern Mediterranean and central Europe and used a cultivation approach to study their endophytic communities. Cultivation of roots yielded 2601 isolates, which were grouped into 296 operational taxonomic units (OTUs) by internal transcribed spacer sequencing of 1998 representative colonies. Climatic and spatial factors were the best descriptors of the structure of endophytic communities, outweighing soil characteristics, host genotype and geographical distance. OTU richness was negatively affected by precipitation, and the composition of communities followed latitudinal gradients of precipitation and temperature. Only six widespread OTUs belonging to the orders Pleosporales, Hypocreales and Helotiales represented about 50% of all isolates. Assessments of their individual distribution revealed particular ecological preferences or a cosmopolitan occurrence. Our findings support a strong influence of the local environment in determining root endophytic communities, and show a different niche occupancy by individual endophytes. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

Diversity of cultivable fungal endophytes in Paullinia cupana (Mart.) Ducke and bioactivity of their secondary metabolites.

PubMed

Silva, Fábio de Azevedo; Liotti, Rhavena Graziela; Boleti, Ana Paula de Araújo; Reis, Érica de Melo; Passos, Marilene Borges Silva; Dos Santos, Edson Lucas; Sampaio, Olivia Moreira; Januário, Ana Helena; Branco, Carmen Lucia Bassi; Silva, Gilvan Ferreira da; Mendonça, Elisabeth Aparecida Furtado de; Soares, Marcos Antônio

2018-01-01

Paullinia cupana is associated with a diverse community of pathogenic and endophytic microorganisms. We isolated and identified endophytic fungal communities from the roots and seeds of P. cupana genotypes susceptible and tolerant to anthracnose that grow in two sites of the Brazilian Amazonia forest. We assessed the antibacterial, antitumor and genotoxic activity in vitro of compounds isolated from the strains Trichoderma asperellum (1BDA) and Diaporthe phaseolorum (8S). In concert, we identified eight fungal species not previously reported as endophytes; some fungal species capable of inhibiting pathogen growth; and the production of antibiotics and compounds with bacteriostatic activity against Pseudomonas aeruginosa in both susceptible and multiresistant host strains. The plant genotype, geographic location and specially the organ influenced the composition of P. cupana endophytic fungal community. Together, our findings identify important functional roles of endophytic species found within the microbiome of P. cupana. This hypothesis requires experimental validation to propose management of this microbiome with the objective of promoting plant growth and protection.

Diversity of cultivable fungal endophytes in Paullinia cupana (Mart.) Ducke and bioactivity of their secondary metabolites

PubMed Central

Liotti, Rhavena Graziela; Boleti, Ana Paula de Araújo; Reis, Érica de Melo; Passos, Marilene Borges Silva; dos Santos, Edson Lucas; Sampaio, Olivia Moreira; Januário, Ana Helena; Branco, Carmen Lucia Bassi; da Silva, Gilvan Ferreira; de Mendonça, Elisabeth Aparecida Furtado

2018-01-01

Paullinia cupana is associated with a diverse community of pathogenic and endophytic microorganisms. We isolated and identified endophytic fungal communities from the roots and seeds of P. cupana genotypes susceptible and tolerant to anthracnose that grow in two sites of the Brazilian Amazonia forest. We assessed the antibacterial, antitumor and genotoxic activity in vitro of compounds isolated from the strains Trichoderma asperellum (1BDA) and Diaporthe phaseolorum (8S). In concert, we identified eight fungal species not previously reported as endophytes; some fungal species capable of inhibiting pathogen growth; and the production of antibiotics and compounds with bacteriostatic activity against Pseudomonas aeruginosa in both susceptible and multiresistant host strains. The plant genotype, geographic location and specially the organ influenced the composition of P. cupana endophytic fungal community. Together, our findings identify important functional roles of endophytic species found within the microbiome of P. cupana. This hypothesis requires experimental validation to propose management of this microbiome with the objective of promoting plant growth and protection. PMID:29649297

Melanised endophytic fungi may increase stores of organic carbon in soil

NASA Astrophysics Data System (ADS)

McGee, Peter; Mukasa Mugerwa, Tendo

2013-04-01

The processes underlying the carbon cycle in soil, especially sequestration of organic carbon (OC), are poorly understood. Hydrolysis and oxidation reduce organic matter. Hydrolysis degrades linear organic molecules in aerobic and anaerobic conditions, though it is slower in anaerobic conditions. Aromatic compounds are only degraded by oxidation. Oxygen is by far the most common electron acceptor in soil. Anaerobic conditions preclude oxidation in soil and will result in the preservation of aromatic compounds so long as the conditions remain anaerobic. We experimentally tested this model using melanised endophytic fungi. Melanin is a polyaromatic compound that can be readily visualised, though is difficult to quantify. An endophytic association provides the fungus with an ongoing source of energy. Fungal hyphae elongate considerable distances in soil where they may colonise aggregates, the core of which may be anaerobic. The hypothesis we tested is that melanised endophytic fungi increase OC in soil. Seedlings of subterranean clover inoculated with single isolates were grown in split pots where the impact of the fungus could be quantified in the hyphal chamber, separated from the roots by a steel mesh. We found that melanised endophytic fungi significantly increased OC and aromatic carbon in a well-aggregated carbon-rich soil. OC increased by up to 17% within 14 weeks. Twenty out of 24 isolates statistically significantly increased and none decreased OC. Increases differed between fungal isolates. Increases in the hyphal chamber were independent of any change in OC associated with the roots of the host plant. The storage of OC in field soils is being explored. Inoculation of plant roots with melanised endophytic fungi offers one means whereby OC may be increased in field soils.

Bioactive Constituents from an Endophytic Fungus, Penicillium polonicum NFW9, Associated with Taxus fauna.

PubMed

Fatima, Nighat; Sripisut, Tawanun; Youn, Ui J; Ahmed, Safia; Ul-Haq, Ihsan; Munoz-Acuna, Ulyana; Simmons, Charles J; Qazi, Muneer A; Jadoon, Muniba; Tan, Ghee T; de Blanco, Esperanza J C; Chang, Leng C

2017-01-01

Endophytic fungi are being recognized as vital and untapped sources of a variety of structurally novel and unique bioactive secondary metabolites in the field of natural products drug discovery. Herein, this study reports the isolation and characterization of secondary metabolites from an endophytic fungus Penicillium polonicum (NFW9) associated with Taxus fuana. The extracts of the endophytic fungus cultured on potato dextrose agar were purified using several chromatographic techniques. Biological evaluation was performed based on their abilities to inhibit tumor necrosis factor-alpha (TNF-α)-induced nuclear factor-kappa B (NF-κB) and cytotoxicity assays. Bioactivity-directed fractionation of the ethyl acetate extract of a fermentation culture of an endophytic fungus, Penicillium polonicum led to the isolation of a dimeric anthraquinone, (R)- 1,1',3,3',5,5'-hexahydroxy-7,7'-dimethyl[2,2'-bianthracene]-9,9',10,10'-tetraone (1), a steroidal furanoid (-)-wortmannolone (2), along with three other compounds (3-4). Moreover, this is the first report on the isolation of compound 1 from an endophytic fungus. All purified metabolites were characterized by NMR and MS data analyses. The stereo structure of compound 1 was determined by the measurement of specific optical rotation and CD spectrum. The relative stereochemistry of 2 was confirmed by single-crystal X-ray diffraction. Compounds 2-3 showed inhibitory activities in the TNF-α-induced NF-κB assay with IC50 values in the range of 0.47-2.11 µM. Compounds 1, 4 and 5 showed moderate inhibition against NF-κB and cancer cell lines. The endophytic fungus Penicillium polonicum of Taxus fuana is capable of producing biologically active natural compounds. Our results provide a scientific rationale for further chemical investigations into endophyte-producing natural products, drug discovery and development. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Endophytic l-asparaginase-producing fungi from plants associated with anticancer properties.

PubMed

Chow, YiingYng; Ting, Adeline S Y

2015-11-01

Endophytes are novel sources of natural bioactive compounds. This study seeks endophytes that produce the anticancer enzyme l-asparaginase, to harness their potential for mass production. Four plants with anticancer properties; Cymbopogon citratus, Murraya koenigii, Oldenlandia diffusa and Pereskia bleo, were selected as host plants. l-Asparaginase-producing endophytes were detected by the formation of pink zones on agar, a result of hydrolyzes of asparagine into aspartic acid and ammonia that converts the phenol red dye indicator from yellow (acidic condition) to pink (alkaline condition). The anticancer enzyme asparaginase was further quantified via Nesslerization. Results revealed that a total of 89 morphotypes were isolated; mostly from P. bleo (40), followed by O. diffusa (25), C. citratus (14) and M. koenigii (10). Only 25 of these morphotypes produced l-asparaginase, mostly from P. bleo and their asparaginase activities were between 0.0069 and 0.025 μM mL(-1) min(-1). l-Asparaginase producing isolates were identified as probable species of the genus Colletotrichum, Fusarium, Phoma and Penicillium. Studies here revealed that endophytes are good alternative sources for l-asparaginase production and they can be sourced from anticancer plants, particularly P. bleo.

Endophytic l-asparaginase-producing fungi from plants associated with anticancer properties

PubMed Central

Chow, YiingYng; Ting, Adeline S.Y.

2014-01-01

Endophytes are novel sources of natural bioactive compounds. This study seeks endophytes that produce the anticancer enzyme l-asparaginase, to harness their potential for mass production. Four plants with anticancer properties; Cymbopogon citratus, Murraya koenigii, Oldenlandia diffusa and Pereskia bleo, were selected as host plants. l-Asparaginase-producing endophytes were detected by the formation of pink zones on agar, a result of hydrolyzes of asparagine into aspartic acid and ammonia that converts the phenol red dye indicator from yellow (acidic condition) to pink (alkaline condition). The anticancer enzyme asparaginase was further quantified via Nesslerization. Results revealed that a total of 89 morphotypes were isolated; mostly from P. bleo (40), followed by O. diffusa (25), C. citratus (14) and M. koenigii (10). Only 25 of these morphotypes produced l-asparaginase, mostly from P. bleo and their asparaginase activities were between 0.0069 and 0.025 μM mL−1 min−1. l-Asparaginase producing isolates were identified as probable species of the genus Colletotrichum, Fusarium, Phoma and Penicillium. Studies here revealed that endophytes are good alternative sources for l-asparaginase production and they can be sourced from anticancer plants, particularly P. bleo. PMID:26644924

Colonization of onions by endophytic fungi and their impacts on the biology of Thrips tabaci.

PubMed

Muvea, Alexander M; Meyhöfer, Rainer; Subramanian, Sevgan; Poehling, Hans-Michael; Ekesi, Sunday; Maniania, Nguya K

2014-01-01

Endophytic fungi, which live within host plant tissues without causing any visible symptom of infection, are important mutualists that mediate plant-herbivore interactions. Thrips tabaci (Lindeman) is one of the key pests of onion, Allium cepa L., an economically important agricultural crop cultivated worldwide. However, information on endophyte colonization of onions, and their impacts on the biology of thrips feeding on them, is lacking. We tested the colonization of onion plants by selected fungal endophyte isolates using two inoculation methods. The effects of inoculated endophytes on T. tabaci infesting onion were also examined. Seven fungal endophytes used in our study were able to colonize onion plants either by the seed or seedling inoculation methods. Seed inoculation resulted in 1.47 times higher mean percentage post-inoculation recovery of all the endophytes tested as compared to seedling inoculation. Fewer thrips were observed on plants inoculated with Clonostachys rosea ICIPE 707, Trichoderma asperellum M2RT4, Trichoderma atroviride ICIPE 710, Trichoderma harzianum 709, Hypocrea lixii F3ST1 and Fusarium sp. ICIPE 712 isolates as compared to those inoculated with Fusarium sp. ICIPE 717 and the control treatments. Onion plants colonized by C. rosea ICIPE 707, T. asperellum M2RT4, T. atroviride ICIPE 710 and H. lixii F3ST1 had significantly lower feeding punctures as compared to the other treatments. Among the isolates tested, the lowest numbers of eggs were laid by T. tabaci on H. lixii F3ST1 and C. rosea ICIPE 707 inoculated plants. These results extend the knowledge on colonization of onions by fungal endophytes and their effects on Thrips tabaci.

Colonization of Onions by Endophytic Fungi and Their Impacts on the Biology of Thrips tabaci

PubMed Central

Muvea, Alexander M.; Meyhöfer, Rainer; Subramanian, Sevgan; Poehling, Hans-Michael; Ekesi, Sunday; Maniania, Nguya K.

2014-01-01

Endophytic fungi, which live within host plant tissues without causing any visible symptom of infection, are important mutualists that mediate plant–herbivore interactions. Thrips tabaci (Lindeman) is one of the key pests of onion, Allium cepa L., an economically important agricultural crop cultivated worldwide. However, information on endophyte colonization of onions, and their impacts on the biology of thrips feeding on them, is lacking. We tested the colonization of onion plants by selected fungal endophyte isolates using two inoculation methods. The effects of inoculated endophytes on T. tabaci infesting onion were also examined. Seven fungal endophytes used in our study were able to colonize onion plants either by the seed or seedling inoculation methods. Seed inoculation resulted in 1.47 times higher mean percentage post-inoculation recovery of all the endophytes tested as compared to seedling inoculation. Fewer thrips were observed on plants inoculated with Clonostachys rosea ICIPE 707, Trichoderma asperellum M2RT4, Trichoderma atroviride ICIPE 710, Trichoderma harzianum 709, Hypocrea lixii F3ST1 and Fusarium sp. ICIPE 712 isolates as compared to those inoculated with Fusarium sp. ICIPE 717 and the control treatments. Onion plants colonized by C. rosea ICIPE 707, T. asperellum M2RT4, T. atroviride ICIPE 710 and H. lixii F3ST1 had significantly lower feeding punctures as compared to the other treatments. Among the isolates tested, the lowest numbers of eggs were laid by T. tabaci on H. lixii F3ST1 and C. rosea ICIPE 707 inoculated plants. These results extend the knowledge on colonization of onions by fungal endophytes and their effects on Thrips tabaci. PMID:25254657

A Marine Actinomycete Rescues Caenorhabditis elegans from Pseudomonas aeruginosa Infection through Restitution of Lysozyme 7

PubMed Central

Fatin, Siti N.; Boon-Khai, Tan; Shu-Chien, Alexander Chong; Khairuddean, Melati; Al-Ashraf Abdullah, Amirul

2017-01-01

The resistance of Pseudomonas aeruginosa to conventional antimicrobial treatment is a major scourge in healthcare. Therefore, it is crucial that novel potent anti-infectives are discovered. The aim of the present study is to screen marine actinomycetes for chemical entities capable of overcoming P. aeruginosa infection through mechanisms involving anti-virulence or host immunity activities. A total of 18 actinomycetes isolates were sampled from marine sediment of Songsong Island, Kedah, Malaysia. Upon confirming that the methanolic crude extract of these isolates do not display direct bactericidal activities, they were tested for capacity to rescue Caenorhabditis elegans infected with P. aeruginosa strain PA14. A hexane partition of the extract from one isolate, designated as Streptomyces sp. CCB-PSK207, could promote the survival of PA14 infected worms by more than 60%. Partial 16S sequence analysis on this isolate showed identity of 99.79% with Streptomyces sundarbansensis. This partition did not impair feeding behavior of C. elegans worms. Tested on PA14, the partition also did not affect bacterial growth or its ability to colonize host gut. The production of biofilm, protease, and pyocyanin in PA14 were uninterrupted, although there was an increase in elastase production. In lys-7::GFP worms, this partition was shown to induce the expression of lysozyme 7, an important innate immunity defense molecule that was repressed during PA14 infection. GC-MS analysis of the bioactive fraction of Streptomyces sp. CCB-PSK207 revealed the presence of methyl esters of branched saturated fatty acids. In conclusion, this is the first report of a marine actinomycete producing metabolites capable of rescuing C. elegans from PA14 through a lys-7 mediated activity. PMID:29201023

Actinoplanes rhizophilus sp. nov., an actinomycete isolated from the rhizosphere of Sansevieria trifasciata Prain.

PubMed

He, Hairong; Xing, Jia; Liu, Chongxi; Li, Chuang; Ma, Zhaoxu; Li, Jiansong; Xiang, Wensheng; Wang, Xiangjing

2015-12-01

A novel actinomycete, designated strain NEAU-A-2T, was isolated from the rhizosphere soil of Sansevieria trifasciata Prain collected from Heilongjiang province, north-east China. The taxonomic status of this organism was established using a polyphasic approach. The isolate formed irregular sporangia containing motile spores on the substrate mycelium. The whole-cell sugars were xylose and galactose. The predominant menaquinones were MK-9(H10), MK-9(H2), MK-10(H2) and MK-10(H4). The major fatty acids were iso-C15 : 0, iso-C16 : 0 and anteiso-C15 : 0. The polar lipids were diphosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, phosphatidylinositol, three unidentified phospholipids and an unidentified glycolipid. 16S rRNA gene sequence similarity studies showed that strain NEAU-A-2T belongs to the genus Actinoplanes with the highest sequence similarities to Actinoplanes globisporus NBRC 13912T (97.7 % 16S rRNA gene sequence similarity), Actinoplanes ferrugineus IMSNU 22125T (97.5 %), Actinoplanes toevensis MN07-A0368T (97.2 %) and Actinoplanes rishiriensis NBRC 108556T (97.2 %); similarities to type strains of other species of this genus were < 97 %. Two tree-making algorithms showed that strain NEAU-A-2T formed a distinct clade with A. globisporus NBRC 13912T and A. rishiriensis NBRC 108556T. However, low DNA-DNA relatedness values allowed the isolate to be differentiated from the above-mentioned two species of the genus Actinoplanes. Moreover, strain NEAU-A-2T could also be distinguished from the most closely related species by morphological and physiological characteristics. Therefore, in conclusion, isolate NEAU-A-2T represents a novel species of the genus Actinoplanes, for which the name Actinoplanes rhizophilus sp. nov. is proposed. The type strain is NEAU-A-2T ( = CGMCC 4.7133T = DSM 46672T).

Molecular phylogenetics and anti-Pythium activity of endophytes from rhizomes of wild ginger congener, Zingiber zerumbet Smith.

PubMed

Keerthi, D; Aswati Nair, R; Prasath, D

2016-03-01

Zingiber zerumbet, a perennial rhizomatous herb exhibits remarkable disease resistance as well as a wide range of pharmacological activities. Towards characterizing the endophytic population of Z. zerumbet rhizomes, experiments were carried out during two different growing seasons viz., early-June of 2013 and late-July of 2014. A total of 34 endophytes were isolated and categorized into 11 morphologically distinct groups. Fungi were observed to predominate bacterial species with colonization frequency values ranging from 12.5 to 50%. Among the 11 endophyte groups isolated, molecular analyses based on ITS/16S rRNA gene sequences identified seven isolate groups as Fusarium solani, two as F. oxysporum and one as the bacterium Rhizobium spp. Phylogenetic tree clustered the ITS sequences from Z. zerumbet endophytes into distinct clades consistent with morphological and sequence analysis. Dual culture assays were carried out to determine antagonistic activity of the isolated endophytes against Pythium myriotylum, an economically significant soil-borne phytopathogen of cultivated ginger. Experiments revealed significant P. myriotylum growth inhibition by F. solani and F. oxysporum isolates with percentage of inhibition (PoI) ranging from 45.17 ± 0.29 to 62.2 ± 2.58 with F. oxysporum exhibiting higher PoI values against P. myriotylum. Using ZzEF8 metabolite extract, concentration-dependent P. myriotylum hyphal growth inhibition was observed following radial diffusion assays. These observations were confirmed by scanning electron microscopy analysis wherein exposure to ZzEF8 metabolite extract induced hyphal deformities. Results indicate Z. zerumbet endophytes as promising resources for biologically active compounds and as biocontrol agents for soft rot disease management caused by Pythium spp.

Enrichment culture and identification of endophytic methanotrophs isolated from peatland plants.

PubMed

Stępniewska, Zofia; Goraj, Weronika; Kuźniar, Agnieszka; Łopacka, Natalia; Małysza, Magdalena

2017-09-01

Aerobic methane-oxidizing bacteria (MOB) are an environmentally significant group of microorganisms due to their role in the global carbon cycle. Research conducted over the past few decades has increased the interest in discovering novel genera of methane-degrading bacteria, which efficiently utilize methane and decrease the global warming effect. Moreover, methanotrophs have more promising applications in environmental bioengineering, biotechnology, and pharmacy. The investigations were undertaken to recognize the variety of endophytic methanotrophic bacteria associated with Carex nigra, Vaccinium oxycoccus, and Eriophorum vaginatum originating from Moszne peatland (East Poland). Methanotrophic bacteria were isolated from plants by adding sterile fragments of different parts of plants (roots and stems) to agar mineral medium (nitrate mineral salts (NMS)) and incubated at different methane values (1-20% CH4). Single colonies were streaked on new NMS agar media and, after incubation, transferred to liquid NMS medium. Bacterial growth dynamics in the culture solution was studied by optical density-OD600 and methane consumption. Changes in the methane concentration during incubation were controlled by the gas chromatography technique. Characterization of methanotrophs was made by fluorescence in situ hybridization (FISH) with Mg705 and Mg84 for type I methanotrophs and Ma450 for type II methanotrophs. Identification of endophytes was performed after 16S ribosomal RNA (rRNA) and mmoX gene amplification. Our study confirmed the presence of both types of methanotrophic bacteria (types I and II) with the predominance of type I methanotrophs. Among cultivable methanotrophs, there were different strains of the genus Methylomonas and Methylosinus. Furthermore, we determined the potential of the examined bacteria for methane oxidation, which ranged from 0.463 ± 0.067 to 5.928 ± 0.169 μmol/L CH4/mL/day.

Diversity and taxonomy of endophytic xylariaceous fungi from medicinal plants of Dendrobium (Orchidaceae).

PubMed

Chen, Juan; Zhang, Li-Chun; Xing, Yong-Mei; Wang, Yun-Qiang; Xing, Xiao-Ke; Zhang, Da-Wei; Liang, Han-Qiao; Guo, Shun-Xing

2013-01-01

Dendrobium spp. are traditional Chinese medicinal plants, and the main effective ingredients (polysaccharides and alkaloids) have pharmacologic effects on gastritis infection, cancer, and anti-aging. Previously, we confirmed endophytic xylariaceous fungi as the dominant fungi in several Dendrobium species of tropical regions from China. In the present study, the diversity, taxonomy, and distribution of culturable endophytic xylariaceous fungi associated with seven medicinal species of Dendrobium (Orchidaceae) were investigated. Among the 961 endophytes newly isolated, 217 xylariaceous fungi (morphotaxa) were identified using morphological and molecular methods. The phylogenetic tree constructed using nuclear ribosomal internal transcribed spacer (ITS), large subunit of ribosomal DNA (LSU), and beta-tubulin sequences divided these anamorphic xylariaceous isolates into at least 18 operational taxonomic units (OTUs). The diversity of the endophytic xylariaceous fungi in these seven Dendrobium species was estimated using Shannon and evenness indices, with the results indicating that the dominant Xylariaceae taxa in each Dendrobium species were greatly different, though common xylariaceous fungi were found in several Dendrobium species. These findings implied that different host plants in the same habitats exhibit a preference and selectivity for their fungal partners. Using culture-dependent approaches, these xylariaceous isolates may be important sources for the future screening of new natural products and drug discovery.

Diversity and Taxonomy of Endophytic Xylariaceous Fungi from Medicinal Plants of Dendrobium (Orchidaceae)

PubMed Central

Chen, Juan; Zhang, Li-Chun; Xing, Yong-Mei; Wang, Yun-Qiang; Xing, Xiao-Ke; Zhang, Da-Wei; Liang, Han-Qiao; Guo, Shun-Xing

2013-01-01

Dendrobium spp. are traditional Chinese medicinal plants, and the main effective ingredients (polysaccharides and alkaloids) have pharmacologic effects on gastritis infection, cancer, and anti-aging. Previously, we confirmed endophytic xylariaceous fungi as the dominant fungi in several Dendrobium species of tropical regions from China. In the present study, the diversity, taxonomy, and distribution of culturable endophytic xylariaceous fungi associated with seven medicinal species of Dendrobium (Orchidaceae) were investigated. Among the 961 endophytes newly isolated, 217 xylariaceous fungi (morphotaxa) were identified using morphological and molecular methods. The phylogenetic tree constructed using nuclear ribosomal internal transcribed spacer (ITS), large subunit of ribosomal DNA (LSU), and beta-tubulin sequences divided these anamorphic xylariaceous isolates into at least 18 operational taxonomic units (OTUs). The diversity of the endophytic xylariaceous fungi in these seven Dendrobium species was estimated using Shannon and evenness indices, with the results indicating that the dominant Xylariaceae taxa in each Dendrobium species were greatly different, though common xylariaceous fungi were found in several Dendrobium species. These findings implied that different host plants in the same habitats exhibit a preference and selectivity for their fungal partners. Using culture-dependent approaches, these xylariaceous isolates may be important sources for the future screening of new natural products and drug discovery. PMID:23472167

Fungal endophytes in above-ground tissues of desert plants: infrequent in culture, but highly diverse and distinctive symbionts

PubMed Central

Massimo, Nicholas C.; Nandi Devan, MM; Arendt, Kayla R.; Wilch, Margaret H.; Riddle, Jakob M.; Furr, Susan H.; Steen, Cole; U'Ren, Jana M.; Sandberg, Dustin C.; Arnold, A. Elizabeth

2015-01-01

In hot deserts, plants cope with aridity, high temperatures, and nutrient-poor soils with morphological and biochemical adaptations that encompass intimate microbial symbioses. Whereas the root microbiomes of arid-land plants have received increasing attention, factors influencing assemblages of symbionts in above-ground tissues have not been evaluated for many woody plants that flourish in desert environments. We evaluated the diversity, host affiliations, and distributions of endophytic fungi associated with photosynthetic tissues of desert trees and shrubs, focusing on non-succulent woody plants in the species-rich Sonoran Desert. To inform our strength of inference, we evaluated the effects of two different nutrient media, incubation temperatures, and collection seasons on the apparent structure of endophyte assemblages. Analysis of >22,000 tissue segments revealed that endophytes were isolated four times more frequently from photosynthetic stems than leaves. Isolation frequency was lower than expected given the latitude of the study region, and varied among species a function of sampling site and abiotic factors. However, endophytes were very species-rich and phylogenetically diverse, consistent with less-arid sites of a similar latitudinal position. Community composition differed among host species, but not as a function of tissue type, sampling site, sampling month, or exposure. Estimates of abundance, diversity and composition were not influenced by isolation medium or incubation temperature. Phylogenetic analyses of the most commonly isolated genus (Preussia) revealed multiple evolutionary origins of desert-plant endophytism and little phylogenetic structure with regard to seasonality, tissue preference, or optimal temperatures and nutrients for growth in vitro. Together, these results provide insight into endophytic symbioses in desert plant communities, and can be used to optimize strategies for capturing endophyte biodiversity at regional scales. PMID

Pervasive effects of wildfire on foliar endophyte communities in montane forest trees

PubMed Central

Huang, Yu-Ling; Devan, MM Nandi; U'Ren, Jana M.; Furr, Susan H.; Arnold, A. Elizabeth

2015-01-01

Plants in all terrestrial ecosystems form symbioses with endophytic fungi that inhabit their healthy tissues. How these foliar endophytes respond to wildfires has not been studied previously, but is important given the increasing frequency and intensity of severe wildfires in many ecosystems, and because endophytes can influence plant growth and responses to stress. The goal of this study was to examine effects of severe wildfires on endophyte communities in forest trees, with a focus on traditionally fire-dominated, montane ecosystems in the southwestern USA. We evaluated the abundance, diversity, and composition of endophytes in foliage of Juniperus deppeana (Cupressaceae) and Quercus spp. (Fagaceae) collected contemporaneously from areas affected by recent wildfire and paired areas not affected by recent fire. Study sites spanned four mountain ranges in central and southern Arizona. Our results revealed significant effects of fires on endophyte communities, including decreases in isolation frequency, increases in diversity, and shifts in community structure and taxonomic composition among endophytes of trees affected by recent fires. Responses to fire were similar in endophytes of each host in these fire-dominated ecosystems and reflect regional fire-return intervals, with endophytes after fire representing subsets of the regional mycoflora. Together these findings contribute to an emerging perspective on the responses of diverse communities to severe fire, and highlight the importance of considering fire history when estimating endophyte diversity and community structure for focal biomes. PMID:26370111

The Biological Diversity and Production of Volatile Organic Compounds by Stem-Inhabiting Endophytic Fungi of Ecuador

PubMed Central

Rundell, Susan M.; Spakowicz, Daniel J.; Narváez-Trujillo, Alexandra; Strobel, Scott A.

2015-01-01

Fungal endophytes colonize every major lineage of land plants without causing apparent harm to their hosts. Despite their production of interesting and potentially novel compounds, endophytes—particularly those inhabiting stem tissues—are still a vastly underexplored component of microbial diversity. In this study, we explored the diversity of over 1500 fungal endophyte isolates collected from three Ecuadorian ecosystems: lowland tropical forest, cloud forest, and coastal dry forest. We sought to determine whether Ecuador’s fungal endophytes are hyperdiverse, and whether that biological diversity is reflected in the endophytes’ chemical diversity. To assess this chemical diversity, we analyzed a subset of isolates for their production of volatile organic compounds (VOCs), a representative class of natural products. This study yielded a total of 1526 fungal ITS sequences comprising some 315 operational taxonomic units (OTUs), resulting in a non-asymptotic OTU accumulation curve and characterized by a Fisher’s α of 120 and a Shannon Diversity score of 7.56. These figures suggest that the Ecuadorian endophytes are hyperdiverse. Furthermore, the 113 isolates screened for VOCs produced more than 140 unique compounds. These results present a mere snapshot of the remarkable biological and chemical diversity of stem-inhabiting endophytic fungi from a single neotropical country. PMID:29376917

[Effect on calcium carbonate morphology by a strain of rock actinomycete].

PubMed

Chu, Yue; Cao, Chengliang; Lian, Bin

2016-07-04

Microbes-induced mineralization is one of the hottest issues in the field of geomicrobiology. Strain DHS C013T isolated from the surfaces of rocks in the Karst region was used to investigate microbial influence on the formation of carbonate and its morphology in the metallogenic system consisting NaHCO3 and Ca(NO3)2·4H2O. Strain DHS C013T was inoculated into malt extract-glucose-yeast extract peptone (MGYP) liquid medium. After cultivation we put the fermented solution, supernatant, hypha pellets, sterile MGYP liquid medium and ultrapure water into the metallogenic system separately. Scanning electronic microscope was applied to observe the crystals at the bottom of the petri dishes. In the metallogenic system with ultrapure water, only standard calcite of rhombohedron was found. However, special morphology of CaCO3, such as dumbbelllike, spherulite and scaly cylindrical shapes, were found in the metallogenic system with actinomycetes, hyphae fragment and their cell metabolism products. These calcium carbonates of special morphology might be resulted from their nucleation on smaller hypha pellets, hyphae fragment or extracellular secretion. Actinomycetes can induce the formation of CaCO3, and the mycelium and metabolites have important effects on regulating and influencing CaCO3 morphology. Our data provide new evidence for further understanding of the biological mineralization mediated by actinomycete and its metabolic products.

Salicaceae Endophytes Modulate Stomatal Behavior and Increase Water Use Efficiency in Rice

PubMed Central

Rho, Hyungmin; Van Epps, Victor; Wegley, Nicholas; Doty, Sharon L.; Kim, Soo-Hyung

2018-01-01

Bacterial and yeast endophytes isolated from the Salicaceae family have been shown to promote growth and alleviate stress in plants from different taxa. To determine the physiological pathways through which endophytes affect plant water relations, we investigated leaf water potential, whole-plant water use, and stomatal responses of rice plants to Salicaceae endophyte inoculation under CO2 enrichment and water deficit. Daytime stomatal conductance and stomatal density were lower in inoculated plants compared to controls. Leaf ABA concentrations increased with endophyte inoculation. As a result, transpirational water use decreased significantly with endophyte inoculation while biomass did not change or slightly increased. This response led to a significant increase in cumulative water use efficiency at harvest. Different endophyte strains produced the same results in host plant water relations and stomatal responses. These stomatal responses were also observed under elevated CO2 conditions, and the increase in water use efficiency was more pronounced under water deficit conditions. The effect on water use efficiency was positively correlated with daily light integrals across different experiments. Our results provide insights on the physiological mechanisms of plant-endophyte interactions involving plant water relations and stomatal functions. PMID:29552021

Endophyte-mediated interactions between cauliflower, the herbivore Spodoptera litura, and the ectoparasitoid Bracon hebetor.

PubMed

Kaur, Tamanreet; Singh, Bahaderjeet; Kaur, Amarjeet; Kaur, Sanehdeep

2015-10-01

Fungal endosymbionts in plants may influence interactions among plants, herbivores and their parasitoids through the production of secondary metabolites. We used a lepidopteran pest and its generalist parasitoid to test the effect of endophyte-infected plants on a third trophic level. Endophytic fungi, Aspergillus flavus and Aspergillus niger, isolated from Acacia arabica, were used to infect cauliflower plants. We found that the presence of the endophyte in the plants significantly extended the development period of Spodoptera litura (Fab.) larvae. Feeding of the host on endophyte-infected plants further adversely affected the development and performance of its parasitoid, Bracon hebetor (Say). A negative impact was also recorded for longevity and fecundity of endophyte-naive parasitoid females due to the parasitization of host larvae fed on endophyte-infected plants. The presence of endophytes in the diet of the host larvae significantly prolonged the development of the parasitoid. A strong detrimental effect was also recorded for larval survival and emergence of parasitoid adults. The longevity and parasitism rate of female wasps were reduced significantly due to the ingestion of endophyte-infected cauliflower plants by S. litura larvae. Overall, we found that both endophytic fungi had a negative impact on the parasitoid.

Endophytic fungi from medicinal plant Bauhinia forficata : Diversity and biotechnological potential

PubMed Central

Bezerra, Jadson D.P.; Nascimento, Carlos C.F.; Barbosa, Renan do N.; da Silva, Dianny C.V.; Svedese, Virgínia M.; Silva-Nogueira, Eliane B.; Gomes, Bruno S.; Paiva, Laura M.; Souza-Motta, Cristina M.

2015-01-01

Bauhinia forficata is native to South America and used with relative success in the folk medicine in Brazil. The diversity, antibacterial activity, and extracellular hydrolytic enzymes of endophytic fungi associated with this plant were studied. Plant samples, which included leaves, sepals, stems, and seeds, were used. Ninety-five endophytic fungal were isolated (18 from leaves, 22 from sepals, 46 from stems, and nine from seeds), comprising 28 species. The most frequently isolated species were Acremonium curvulum (9.5%), Aspergillus ochraceus (7.37%), Gibberella fujikuroi (10.53%), Myrothecium verrucaria (10.53%) and Trichoderma piluliferum (7.37%). Diversity and species richness were higher in stem tissues, and Sorensen’s index of similarity between the tissues was low. Eleven fungi showed antibacterial activity. Aspergillus ochraceus , Gibberella baccata , Penicillium commune , and P. glabrum were those with the greatest antibacterial activity against Staphylococcus aureus and/or Streptococcus pyogenes . Thirteen species showed proteolytic activity, particularly Phoma putaminum . Fourteen species were cellulase positive, particularly the Penicillium species and Myrmecridium schulzeri . All isolates tested were xylanase positive and 10 showed lipolytic activity, especially Penicillium glabrum . It is clear that the endophytic fungi from B. forficata have potential for the production of bioactive compounds and may be a source of new therapeutic agents for the effective treatment of diseases in humans, other animals, and plants. To our knowledge, this is the first study of endophytic fungi from different tissues of B. forficata and their biotechnological potential. PMID:26221088

Endophytic fungi from medicinal plant Bauhinia forficata: Diversity and biotechnological potential.

PubMed

Bezerra, Jadson D P; Nascimento, Carlos C F; Barbosa, Renan do N; da Silva, Dianny C V; Svedese, Virgínia M; Silva-Nogueira, Eliane B; Gomes, Bruno S; Paiva, Laura M; Souza-Motta, Cristina M

2015-03-01

Bauhinia forficata is native to South America and used with relative success in the folk medicine in Brazil. The diversity, antibacterial activity, and extracellular hydrolytic enzymes of endophytic fungi associated with this plant were studied. Plant samples, which included leaves, sepals, stems, and seeds, were used. Ninety-five endophytic fungal were isolated (18 from leaves, 22 from sepals, 46 from stems, and nine from seeds), comprising 28 species. The most frequently isolated species were Acremonium curvulum (9.5%), Aspergillus ochraceus (7.37%), Gibberella fujikuroi (10.53%), Myrothecium verrucaria (10.53%) and Trichoderma piluliferum (7.37%). Diversity and species richness were higher in stem tissues, and Sorensen's index of similarity between the tissues was low. Eleven fungi showed antibacterial activity. Aspergillus ochraceus , Gibberella baccata , Penicillium commune , and P. glabrum were those with the greatest antibacterial activity against Staphylococcus aureus and/or Streptococcus pyogenes . Thirteen species showed proteolytic activity, particularly Phoma putaminum . Fourteen species were cellulase positive, particularly the Penicillium species and Myrmecridium schulzeri . All isolates tested were xylanase positive and 10 showed lipolytic activity, especially Penicillium glabrum . It is clear that the endophytic fungi from B. forficata have potential for the production of bioactive compounds and may be a source of new therapeutic agents for the effective treatment of diseases in humans, other animals, and plants. To our knowledge, this is the first study of endophytic fungi from different tissues of B. forficata and their biotechnological potential.

Bacillus subtilis and Enterobacter cloacae endophytes from healthy Theobroma cacao L. trees can systemically colonize seedlings and promote growth.

PubMed

Leite, Hianna Almeida Câmara; Silva, Anderson Barbosa; Gomes, Fábio Pinto; Gramacho, Karina Peres; Faria, José Cláudio; de Souza, Jorge Teodoro; Loguercio, Leandro Lopes

2013-03-01

Clonal genotypes resistant to fungal diseases are an important component of the cocoa production system in southeastern Bahia state (Brazil), so that technologies for faster production of stronger and healthier plantlets are highly desirable. In this study, the effects of inoculated bacterial endophytes isolated from healthy adult cacao plants on seedlings, and aspects related to inoculation methods, colonization patterns, and photosynthesis were investigated. Sequencing of 16S rRNA, hsp-60, and rpo-B genes placed the wild-type isolates within the species Enterobacter cloacae (isolates 341 and 344) and Bacillus subtilis (isolate 629). Spontaneous rifampicin-resistant (rif(R)) variants for 344 were also produced and tested. Endophytic application was either by immersion of surface sterilized seeds in bacterial suspensions or direct inoculation into soil, 20 days after planting non-inoculated seeds into pots. Results from in vitro recovery of inoculated isolates showed that the wild-type endophytes and rif(R) variants systemically colonized the entire cacao seedlings in 15-20 days, regardless of the inoculation method. Some endophytic treatments showed significant increases in seedlings' height, number of leaves, and dry matter. Inoculation methods affected the combined application of endophytes, which maintained the growth-promotion effects, but not in the same manner as in single applications. Interestingly, the 344-3.2 rif(R) variant showed improved performance in relation to both the wild type and another related variant. Photosynthetic rates and stomatal conductance increased significantly for some endophytic treatments, being partially associated with effects on growth and affected by the inoculation method. The results suggest that E. cloacae and B. subtilis endophytes from healthy adult plants (not transmitted by seeds) were able to promote vegetative growth on cacao seedlings. The development of products for large-scale use in seedlings

Phylogenetic Diversity and Antifungal Activity of Endophytic Fungi Associated with Tephrosia purpurea

PubMed Central

Luo, Ze-Ping; Lin, Hai-Yan; Ding, Wen-Bing; He, Hua-Liang

2015-01-01

Sixty-one endophytic fungus strains with different colony morphologies were isolated from the leaves, stems and roots of Tephrosia purpurea with colonization rates of 66.95%, 37.50%, and 26.92%, respectively. Based on internal transcribed spacer sequence analysis, 61 isolates were classified into 16 genera belonging to 3 classes under the phylum Ascomycota. Of the 61 isolates, 6 (9.84%) exhibited antifungal activity against one or more indicator plant pathogenic fungi according to the dual culture test. Isolate TPL25 had the broadest antifungal spectrum of activity, and isolate TPL35 was active against 5 plant pathogenic fungi. Furthermore, culture filtrates of TPL25 and TPL35 exhibited greater than 80% growth inhibition against Sclerotinia sclerotiorum. We conclude that the endophytic fungal strains TPL25 and TPL35 are promising sources of bioactive compounds. PMID:26839503

Antimicrobial activity of saponins produced by two novel endophytic fungi from Panax notoginseng.

PubMed

Jin, Zhaoxia; Gao, Lin; Zhang, Lin; Liu, Tianyi; Yu, Fang; Zhang, Zongshen; Guo, Qiong; Wang, Biying

2017-11-01

Endophytes in plants may be co-producer of the bioactive compounds of their hosts. We conducted a study to bioprospect for saponin-producing endophytic fungi from Panax notoginseng and evaluate the antimicrobial activity of saponins. Two novel fungal endophytes, Fusarium sp. PN8 and Aspergillus sp. PN17, were isolated from traditional Chinese medicinal herb P. notoginseng. After eight days of fermentation, the total saponins produced in the culture broth of PN8 and PN17 were 1.061 and 0.583 mg mL -1 , respectively. The saponin extracts exhibited moderate to high (inhibition zone diameter 15.7-28.4 mm, MIC 1.6-12.5 mg mL -1 ) antimicrobial activity against pathogens tested. Further analysis showed that triterpenoid saponins produced by Fusarium PN8 were Rb 1 , Rd and 20(S)-Rg 3 , while Aspergillus PN17 had the ability to synthesise ginsenoside Re, Rd and 20(S)-Rg 3 . The isolated endophytes may be used as potential sources for microbial production of plant secondary metabolites and for antimicrobial agents.

Actinopolyspora biskrensis sp. nov., a novel halophilic actinomycete isolated from Northern Sahara.

PubMed

Saker, Rafika; Bouras, Noureddine; Meklat, Atika; Zitouni, Abdelghani; Schumann, Peter; Spröer, Cathrin; Klenk, Hans-Peter; Sabaou, Nasserdine

2015-03-01

A novel halophilic, filamentous actinomycete, designated H254(T), was isolated from a Saharan soil sample collected from Biskra (Northern Sahara), and subjected to a polyphasic taxonomic characterization. The strain is Gram-positive, aerobic, and halophilic, and the optimum NaCl concentration for growth is 15-20 % (w/v). The cell-wall hydrolysate contained meso-diaminopimelic acid, and the diagnostic whole-cell sugars were arabinose and galactose. The diagnostic phospholipid detected was phosphatidylcholine, and MK-9(H4) was the predominant menaquinone. The major fatty acid profiles were anteiso-C17:0 (32.8 %), C15:0 (28 %), and iso-C17:0 (12.3 %). Comparative analysis of the 16S rRNA gene sequences revealed that the strain H254(T) formed a well-separated sub-branch within the radiation of the genus Actinopolyspora, and the microorganism was most closely related to Actinopolyspora saharensis DSM 45459(T) (99.2 %), Actinopolyspora halophila DSM 43834(T) (99.1 %), and Actinopolyspora algeriensis DSM 45476(T) (99.0 %). Nevertheless, the strain had relatively lower mean values for DNA-DNA relatedness with the above strains (57.2, 68.4, and 45.6 %, respectively). Based on phenotypic features and phylogenetic position, we propose that strain H254(T) represents a novel species of the genus Actinopolyspora, for which the name Actinopolyspora biskrensis sp. nov. is proposed. The type strain of A. biskrensis is strain H254(T) (=DSM 46684(T) =CECT 8576(T)).

Inhibition of norsolorinic acid accumulation to Aspergillus parasiticus by marine actinomycetes

NASA Astrophysics Data System (ADS)

Yan, Peisheng; Shi, Cuijuan; Shen, Jihong; Wang, Kai; Gao, Xiujun; Li, Ping

2014-11-01

Thirty-six strains of marine actinomycetes were isolated from a sample of marine sediment collected from the Yellow Sea and evaluated in terms of their inhibitory activity on the growth of Aspergillus parasiticus and the production of norsolorinic acid using dual culture plate assay and agar diffusion methods. Among them, three strains showed strong antifungal activity and were subsequently identified as Streptomyces sp. by 16S rRNA gene sequencing analysis. The supernatant from the fermentation of the MA01 strain was extracted sequentially with chloroform and ethyl acetate, and the activities of the extracts were determined by tip culture assay. The assay results show that both extracts inhibited mycelium growth and toxin production, and the inhibitory activities of the extracts increased as their concentrations increased. The results of this study suggest that marine actinomycetes are biologically important for the control of mycotoxins, and that these bacteria could be used as novel biopesticides against mycotoxins.

[Diversity of Bacillus species inhabiting on the surface and endophyte of lichens collected from Wuyi Mountain].

PubMed

Ge, Cibin; Liu, Bo; Che, Jianmei; Chen, Meichun; Liu, Guohong; Wei, Jiangchun

2015-05-04

The present work reported the isolation, identification and diversity of Bacillus species colonizing on the surface and endophyte in lichens collected from Wuyi Mountain. Nine lichen samples of Evernia, Stereocaulon, Menegazzia and other 6 genera belonging to 7 families were collected from Wuyi mountain nature reserve. The bacillus-like species colonizing on the surface and endophyte in these lichens were isolated and identified by 16S rRNA gene sequence analysis. There was no bacillus-like species isolated from Evernia, Ramalina and Lecarona. A total of 34 bacillus-like bacteria were isolated from another 6 lichen samples. These bacteria were identified as 24 species and were classified into Bacillus, Paenibacillus, Brevibacillus, Lysinibacillus and Viridiibacillus. Paenibacillus and Bacillus are the dominant genera, and accounting for 41. 2% and 35. 3% of all isolated bacteria respectively. Brevibacillus, Lysinibacillus and Viridiibacillu were first reported being isolated from lichens. There were different species and quantity of bacillus colonizing on the surface and endophyte in different lichens. The quantity of bacillus colonizing on the surface of Physcia was more than 3.85 x 10(6) cfu/g and was the largest in the isolated bacteria, while the species of bacillus colonizing on the surface and endophyte in Stereocaulon was the most abundant. Most of the isolated bacteria were colonizing on (in) one lichen genera, but Paenibacillus taichungensis, Paenibacillus odorifer, Brevibacillus agri, Lysinibacillus xylanilyticus was respectively colonizing on (in) 2-3 lichen genera and Bacillus mycoides was colonizing on (in) Menegazzia, Cladonia Physcia, and Stereocaulon. There are species and quantity diversity of bacillus colonizing on (in) lichens.

Actinomycetes from Eucalyptus and their biological activities for controlling Eucalyptus leaf and shoot blight.

PubMed

Himaman, Winanda; Thamchaipenet, Arinthip; Pathom-Aree, Wasu; Duangmal, Kannika

2016-01-01

In Thailand, Eucalyptus plantations rapidly expand across the country. Leaf and shoot blight caused by Cryptosporiopsis eucalypti, Cylindrocladium sp. and Teratosphaeria destructans is a serious disease in Eucalyptus plantations. In this study, a total of 477 actinomycete strains were successfully isolated from roots and rhizosphere soil of Eucalyptus. Four hundred and thirty nine isolates were classified as streptomycetes and 38 isolates were non-streptomycetes. Among these isolates, 272 (57.0%), 118 (24.7%) and 241 (50.5%) isolates were antagonistic to Cryptosporiopsis eucalypti, Cylindrocladium sp. and Teratosphaeria destructans, respectively. All isolates were tested for their abilities to produce siderophores, indole acetic acid (IAA) and solubilise phosphate. Most isolates (464, 97.3%) produced siderophores. The majority of isolates (345, 72.3%) solubilised phosphate. In addition, almost half of these isolates (237, 49.7%) produced indole acetic acid. Strain EUSKR2S82 which showed the strongest inhibitory effect against all tested fungi with plant growth promoting ability was selected to test with Eucalyptus. This strain could colonize plant roots and increase Eucalyptus roots length. In a detached leaves bioassay, the disease severity of EUSKR2S82-inoculated Eucalyptus leaves was only 30% compared to 95% in the control treatment. The 16S rRNA gene sequence analysis revealed that the strain EUSKR2S82 was related to Streptomyces ramulosus NRRL-B 2714(T) (99.44% similarity). Identification of non-streptomycete isolates using 16S rRNA gene sequences classified them into 9 genera: Actinoallomurus, Actinomadura, Amycolatopsis, Cryptosporangium, Microbispora, Micromonospora, Nocardia, Nonomuraea and Pseudonocardia. It is evident that Eucalyptus tree harbored several genera of actinomycetes. The selected isolate, EUSKR2S82 showed potential as a candidate for biocontrol agent of leaf and shoot blight of Eucalyptus and to promote growth. Copyright © 2016 Elsevier Gmb

Endohyphal Bacterium Enhances Production of Indole-3-Acetic Acid by a Foliar Fungal Endophyte

PubMed Central

Hoffman, Michele T.; Gunatilaka, Malkanthi K.; Wijeratne, Kithsiri; Gunatilaka, Leslie; Arnold, A. Elizabeth

2013-01-01

Numerous plant pathogens, rhizosphere symbionts, and endophytic bacteria and yeasts produce the important phytohormone indole-3-acetic acid (IAA), often with profound effects on host plants. However, to date IAA production has not been documented among foliar endophytes -- the diverse guild of primarily filamentous Ascomycota that live within healthy, above-ground tissues of all plant species studied thus far. Recently bacteria that live within hyphae of endophytes (endohyphal bacteria) have been detected, but their effects have not been studied previously. Here we show not only that IAA is produced in vitro by a foliar endophyte (here identified as Pestalotiopsis aff. neglecta, Xylariales), but that IAA production is enhanced significantly when the endophyte hosts an endohyphal bacterium (here identified as Luteibacter sp., Xanthomonadales). Both the endophyte and the endophyte/bacterium complex appear to rely on an L-tryptophan dependent pathway for IAA synthesis. The bacterium can be isolated from the fungus when the symbiotic complex is cultivated at 36°C. In pure culture the bacterium does not produce IAA. Culture filtrate from the endophyte-bacterium complex significantly enhances growth of tomato in vitro relative to controls and to filtrate from the endophyte alone. Together these results speak to a facultative symbiosis between an endophyte and endohyphal bacterium that strongly influences IAA production, providing a new framework in which to explore endophyte-plant interactions. PMID:24086270

A comparison of fungal endophytic community diversity in tree leaves of rural and urban temperate forests of Kanto district, eastern Japan.

PubMed

Matsumura, Emi; Fukuda, Kenji

2013-03-01

To clarify the effects of forest fragmentation and a change in tree species composition following urbanization on endophytic fungal communities, we isolated fungal endophytes from the foliage of nine tree species in suburban (Kashiwa City, Chiba) and rural (Mt. Wagakuni, Ibaraki; Mt. Takao, Tokyo) forests and compared the fungal communities between sites and host tree species. Host specificity was evaluated using the index of host specificity (Si), and the number of isolated species, total isolation frequency, and the diversity index were calculated. From just one to several host-specific species were recognized in all host tree species at all sites. The total isolation frequency of all fungal species on Quercus myrsinaefolia, Quercus serrata, and Chamaecyparis obtusa and the total isolation frequency of host-specific species on Q. myrsinaefolia, Q. serrata, and Eurya japonica were significantly lower in Kashiwa than in the rural forests. The similarity indices (nonmetric multidimensional scaling (NMS) and CMH) of endophytic communities among different tree species were higher in Kashiwa, as many tree species shared the same fungal species in the suburban forest. Endophytic fungi with a broad host range were grouped into four clusters suggesting their preference for conifer/broadleaves and evergreen/deciduous trees. Forest fragmentation and isolation by urbanization have been shown to cause the decline of host-specific fungal species and a decrease in β diversity of endophytic communities, i.e., endophytic communities associated with tree leaves in suburban forests were found to be depauperate. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Quorum quenching activity in cell-free lysate of endophytic bacteria isolated from Pterocarpus santalinus Linn., and its effect on quorum sensing regulated biofilm in Pseudomonas aeruginosa PAO1.

PubMed

Rajesh, P S; Ravishankar Rai, V

2014-01-01

Quorum sensing mechanism allows the microorganisms to resist the antibiotic treatment by forming biofilms. Quorum quenching is one of the mechanisms to control the development of drug resistance in microbes. Endophyte bacteria are beneficial to plant growth as they support the immune system against the pathogen attack. The endophytic bacteria present in Pterocarpus santalinus were screened for the presence of N-acyl homoserine lactones (AHLs) degrading bacteria using biosensor strains and further confirmed by quantifying the violacein production. Cell-free lysate of endophytic bacteria, Bacillus firmus PT18 and Enterobacter asburiae PT39 exhibited potent AHL degrading ability by inhibiting about 80% violacein production in biosensor strain. Furthermore, when the cell-free lysate was applied to Pseudomonas aeruginosa PAO1 and PAO1-JP2 biofilm it resulted in significant (p<0.01) inhibition of biofilm formation. The biofilm inhibition was confirmed by visualization of biofilm slides under fluorescence microscopy, which showed decrease in total biomass formation in treated slides. Isolation and amplification of the gene (aiiA) indicated that the presence of AHL lactonase in cell-free lysate and sequence alignment indicated that AiiA contains a "HXHXDH" zinc-binding motif that is being conserved in several groups of metallohydrolases. Therefore, the study shows the potential of AHLs degradation by AHL lactonase present in cell-free lysate of isolated endophytic bacteria and inhibition of quorum sensing regulated biofilm formation in P. aeruginosa PAO1. Copyright © 2013 Elsevier GmbH. All rights reserved.

Isolation and Identification of the Antimicrobial Agent Beauvericin from the Endophytic Fusarium oxysporum 5-19 with NMR and ESI-MS/MS

PubMed Central

Ruan, Chuanfen; Bai, Xuelian; Zhang, Miao; Zhu, Shuangshuang; Jiang, Yingying

2016-01-01

Endophytic microbe has been proved to be one of rich sources of bioactive natural products with potential application for new drug and pesticide discovery. One cyclodepsipeptide, beauvericin, was firstly isolated from the fermentation broth of Fusarium oxysporum 5-19 endophytic on Edgeworthia chrysantha Linn. Its chemical structure was unambiguously identified by a combination of spectroscopic methods, such as HRESI-MS and 1H and 13C NMR. ESI-MS/MS was successfully used to elucidate the splitting decomposition route of the positive molecule ion of beauvericin. Antimicrobial results showed that this cyclodepsipeptide had inhibitory effect on three human pathogenic microbes, Candida albicans, Escherichia coli, and Staphylococcus aureus. In particular, beauvericin exhibited the strongest antimicrobial activity against S. aureus with MIC values of 3.91 μM, which had similar effect with that of the positive control amoxicillin. PMID:27413733

Actinomadura gamaensis sp. nov., a novel actinomycete isolated from soil in Gama, Chad.

PubMed

Abagana, Adam Yacoub; Sun, Pengyu; Liu, Chongxi; Cao, Tingting; Zheng, Weiwei; Zhao, Shanshan; Xiang, Wensheng; Wang, Xiangjing

2016-06-01

A novel single spore-producing actinomycete, designated strain NEAU-Gz5(T), was isolated from a soil sample from Gama, Chad. A polyphasic taxonomic study was carried out to establish the status of this strain. The diamino acid present in the cell wall is meso-diaminopimelic acid. Glucose, mannose and madurose occur in whole cell hydrolysates. The polar lipids were found to consist of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol mannoside and an unidentified glycolipid. The predominant menaquinones were identified as MK-9(H8) and MK-9(H6). The predominant cellular fatty acids were found to be C16:0, iso-C15:0, iso-C16:0 and C18:0 10-methyl. Phylogenetic analysis based on the 16S rRNA gene showed that strain NEAU-Gz5(T) belongs to the genus Actinomadura and is closely related to Actinomadura oligospora JCM 10648(T) (ATCC 43269(T); 98.3 % similarity). However, the low level of DNA-DNA relatedness and some different phenotypic characteristics allowed the strain to be distinguished from its close relatives. Therefore, it is concluded that strain NEAU-Gz5(T) represents a novel species of the genus of Actinomadura, for which the name Actinomadura gamaensis sp. nov. is proposed. The type strain is NEAU-Gz5(T) (= CGMCC 4.7301(T) = DSM 100815(T)).

Quantifying the associations between fungal endophytes and biocontrol-induced herbivory of invasive purple loosestrife (Lythrum salicaria L.).

PubMed

David, Aaron S; Quiram, Gina L; Sirota, Jennie I; Seabloom, Eric W

2016-01-01

Fungal endophytes are one of several groups of heterotrophic organisms that associate with living plants. The net effects of these groups of organisms on each other and ultimately on their host plants depend in part on how they facilitate or antagonize one another. In this study we quantified the associations between endophyte communities and herbivory induced by a biological control in the invasive Lythrum salicaria at various spatial scales using a culture-based approach. We found positive associations between herbivory damage and endophyte isolation frequency and richness at the site level and weak, positive associations at the leaf level. Herbivory damage was more strongly influenced by processes at the site level than were endophyte isolation frequency and community structure, which were influenced by processes at the plant and leaf levels. Furthermore, endophytic taxa found in low herbivory sites were nested subsets of those taxa found at high herbivory sites. Our findings suggest that endophyte communities of L. salicaria are associated with, and potentially facilitated by, biocontrol-induced herbivory. Quantifying the associations between heterotrophic groups ultimately may lead to a clearer understanding of their complex interactions with plants. © 2016 by The Mycological Society of America.

Identification of actinomycetes from plant rhizospheric soils with inhibitory activity against Colletotrichum spp., the causative agent of anthracnose disease.

PubMed

Intra, Bungonsiri; Mungsuntisuk, Isada; Nihira, Takuya; Igarashi, Yasuhiro; Panbangred, Watanalai

2011-04-01

Colletotrichum is one of the most widespread and important genus of plant pathogenic fungi worldwide. Various species of Colletotrichum are the causative agents of anthracnose disease in plants, which is a severe problem to agricultural crops particularly in Thailand. These phytopathogens are usually controlled using chemicals; however, the use of these agents can lead to environmental pollution. Potential non-chemical control strategies for anthracnose disease include the use of bacteria capable of producing anti-fungal compounds such as actinomycetes spp., that comprise a large group of filamentous, Gram positive bacteria from soil. The aim of this study was to isolate actinomycetes capable of inhibiting the growth of Colletotrichum spp, and to analyze the diversity of actinomycetes from plant rhizospheric soil. A total of 304 actinomycetes were isolated and tested for their inhibitory activity against Colletotrichum gloeosporioides strains DoA d0762 and DoA c1060 and Colletotrichum capsici strain DoA c1511 which cause anthracnose disease as well as the non-pathogenic Saccharomyces cerevisiae strain IFO 10217. Most isolates (222 out of 304, 73.0%) were active against at least one indicator fungus or yeast. Fifty four (17.8%) were active against three anthracnose fungi and 17 (5.6%) could inhibit the growth of all three fungi and S. cerevisiae used in the test. Detailed analysis on 30 selected isolates from an orchard at Chanthaburi using the comparison of 16S rRNA gene sequences revealed that most of the isolates (87%) belong to the genus Streptomyces sp., while one each belongs to Saccharopolyspora (strain SB-2) and Nocardiopsis (strain CM-2) and two to Nocardia (strains BP-3 and LK-1). Strains LC-1, LC-4, JF-1, SC-1 and MG-1 exerted high inhibitory activity against all three anthracnose fungi and yeast. In addition, the organic solvent extracts prepared from these five strains inhibited conidial growth of the three indicator fungi. Preliminary analysis of crude

Identification of actinomycetes from plant rhizospheric soils with inhibitory activity against Colletotrichum spp., the causative agent of anthracnose disease

PubMed Central

2011-01-01

Background Colletotrichum is one of the most widespread and important genus of plant pathogenic fungi worldwide. Various species of Colletotrichum are the causative agents of anthracnose disease in plants, which is a severe problem to agricultural crops particularly in Thailand. These phytopathogens are usually controlled using chemicals; however, the use of these agents can lead to environmental pollution. Potential non-chemical control strategies for anthracnose disease include the use of bacteria capable of producing anti-fungal compounds such as actinomycetes spp., that comprise a large group of filamentous, Gram positive bacteria from soil. The aim of this study was to isolate actinomycetes capable of inhibiting the growth of Colletotrichum spp, and to analyze the diversity of actinomycetes from plant rhizospheric soil. Results A total of 304 actinomycetes were isolated and tested for their inhibitory activity against Colletotrichum gloeosporioides strains DoA d0762 and DoA c1060 and Colletotrichum capsici strain DoA c1511 which cause anthracnose disease as well as the non-pathogenic Saccharomyces cerevisiae strain IFO 10217. Most isolates (222 out of 304, 73.0%) were active against at least one indicator fungus or yeast. Fifty four (17.8%) were active against three anthracnose fungi and 17 (5.6%) could inhibit the growth of all three fungi and S. cerevisiae used in the test. Detailed analysis on 30 selected isolates from an orchard at Chanthaburi using the comparison of 16S rRNA gene sequences revealed that most of the isolates (87%) belong to the genus Streptomyces sp., while one each belongs to Saccharopolyspora (strain SB-2) and Nocardiopsis (strain CM-2) and two to Nocardia (strains BP-3 and LK-1). Strains LC-1, LC-4, JF-1, SC-1 and MG-1 exerted high inhibitory activity against all three anthracnose fungi and yeast. In addition, the organic solvent extracts prepared from these five strains inhibited conidial growth of the three indicator fungi

Xylanase and feruloyl esterase from actinomycetes cultures could enhance sugarcane bagasse hydrolysis in the production of fermentable sugars.

PubMed

Rahmani, Nanik; Kahar, Prihardi; Lisdiyanti, Puspita; Hermiati, Euis; Lee, Jaemin; Yopi; Prasetya, Bambang; Ogino, Chiaki; Kondo, Akihiko

2018-02-23

The addition of enzymes that are capable of degrading hemicellulose has a potential to reduce the need for commercial enzymes during biomass hydrolysis in the production of fermentable sugars. In this study, a high xylanase producing actinomycete strain (Kitasatospora sp. ID06-480) and the first ethyl ferulate producing actinomycete strain (Nonomuraea sp. ID06-094) were selected from 797 rare actinomycetes, respectively, which were isolated in Indonesia. The addition (30%, v/v) of a crude enzyme supernatant from the selected strains in sugarcane bagasse hydrolysis with low-level loading (1 FPU/g-biomass) of Cellic® CTec2 enhanced both the released amount of glucose and reducing sugars. When the reaction with Ctec2 was combined with crude enzymes containing either xylanase or feruloyl esterase, high conversion yield of glucose from cellulose at 60.5% could be achieved after 72 h-saccharification.

[Diversity and community structure of endophytic fungi from Taxus chinensis var. mairei].

PubMed

2014-07-01

A total of 628 endophytic fungi were isolated from 480 tissue segments of needles and branches of Taxus chinensis var. mairei. According to morphological characteristics and ITS sequences, they represented 43 taxa in 28 genera, of which 10 Hyphomycetes, 20 Coelomycetes, 12 Ascomycetes and 1 unknown fungus. Phomopsis mali was confirmed as the dominant species. In accordance with relative frequency, Alternaria alternata, Aureobasidium pullulans, Colletotrichum boninense, C. gloeosporioides, Epicoccum nigrum , Fungal sp., Fusarium lateritium, Glomerella cingulata, Magnaporthales sp. , Nigrospora oryzae, Pestalotiopsis maculiformans, P. microspora, Peyronellaea glomerata and Xylaria sp. 1 were more common in T. chinensis var. mairei. T. chinensis var. mairei were severely infected by endophytic fungi. Endophytic fungi were found in 81 percent of plant tissues with a high diversity. Distribution ranges of endophytic fungi were influenced by tissue properties. The colonization rate, richness, diversity of endophytic fungi in needles were obviously lower than in branches, and kinds of endophytic fungi between branches were more similar than those in needles, thus endophytic fungi had tissue preference. In addition, tissue age influenced the community structure of endophytic fungi. The elder branch tissues were, the higher colonization rate, richness, diversity of endophytic fungi were. Systematic studying the diversity and community structure of endophytic fungi in T. chinensis var. mairei and clarifying their distribution regularity in plant tissues would offer basic data and scientific basis for their development and utilization. Discussing the presence of fungal pathogens in healthy plant tissues would be of positive significance for source protection of T. chinensis var. mairei.

Biodegradation of Mixed PAHs by PAH-Degrading Endophytic Bacteria.

PubMed

Zhu, Xuezhu; Ni, Xue; Waigi, Michael Gatheru; Liu, Juan; Sun, Kai; Gao, Yanzheng

2016-08-09

Endophytic bacteria can promote plant growth, induce plant defence mechanisms, and increase plant resistance to organic contaminants. The aims of the present study were to isolate highly PAH-degrading endophytic bacteria from plants growing at PAH-contaminated sites and to evaluate the capabilities of these bacteria to degrade polycyclic aromatic hydrocarbons (PAHs) in vitro, which will be beneficial for re-colonizing target plants and reducing plant PAH residues through the inoculation of plants with endophytic bacteria. Two endophytic bacterial strains P₁ (Stenotrophomonas sp.) and P₃ (Pseudomonas sp.), which degraded more than 90% of phenanthrene (PHE) within 7 days, were isolated from Conyza canadensis and Trifolium pretense L., respectively. Both strains could use naphthalene (NAP), PHE, fluorene (FLR), pyrene (PYR), and benzo(a)pyrene (B(a)P) as the sole sources of carbon and energy. Moreover, these bacteria reduced the contamination of mixed PAHs at high levels after inoculation for 7 days; strain P₁ degraded 98.0% NAP, 83.1% FLR, 87.8% PHE, 14.4% PYR, and 1.6% B(a)P, and strain P₃ degraded 95.3% NAP, 87.9% FLR, 90.4% PHE, 6.9% PYR, and negligible B(a)P. Notably, the biodegradation of PAHs could be promoted through additional carbon and nitrogen nutrients; therein, beef extract was suggested as the optimal co-substrate for the degradation of PAHs by these two strains (99.1% PHE was degraded within 7 days). Compared with strain P₁, strain P₃ has more potential for the use in the removal of PAHs from plant tissues. These results provide a novel perspective in the reduction of plant PAH residues in PAH-contaminated sites through inoculating plants with highly PAH-degrading endophytic bacteria.

Endophytic Bacteria Associated with Hieracium piloselloides: Their Potential for Hydrocarbon-Utilizing and Plant Growth-Promotion.

PubMed

Pawlik, Małgorzata; Piotrowska-Seget, Zofia

2015-01-01

The aim of this study was to assess the potential of 18 crude-oil-degrading endophytic bacteria for removal of hydrocarbons and promotion of plant growth. Strains were isolated from Hieracium piloselloides (tall hawkweed), which grows in soil heavily polluted with petroleum hydrocarbons. Bacteria from the genus Pseudomonas were abundant among the isolates. The potential for hydrocarbon degradation was evaluated by polymerase chain reaction (PCR) analyses of the genes alkB, alkH, C23O, P450, and pah. It was found that 88.89% of the endophytic bacteria contained gene-encoding polycyclic aromatic hydrocarbon (PAH) initial dioxygenase, 61% possessed the 2,3-catechol dioxygenase gene, and 39% of strains that were tested had the cytochrome P-450 hydroxylase gene. All isolates were capable of producing indole-3-acetic acid (1.8-76.4 μg/ml). Only 17% of them were able to produce siderophores, excrete cellulase, and solubilize phosphate. Hydrogen cyanide synthesis occurred in 33% of endophytic bacteria. The 1-aminocyclopropane-1-carboxylate deaminase activity in isolates that were screened was in the range of 2.6 to 74.1 μmol α-ketobutyrate/mg/h. This feature of the bacteria indicated that isolates may enhance the phytoremediation process. Data suggest that crude-oil-degrading endophytic bacteria possess potential to be promising candidates for enhancement of phytoremediation of hydrocarbon-contaminated soil. Further evaluation of these bacteria is needed in order to assess the role played in the degradation of petroleum hydrocarbons.

Nocardiopsis akesuensis sp. nov., an actinomycete isolated from a salt water beach.

PubMed

Gao, Guang-Bin; Luo, Xiao-Xia; Xia, Zhan-Feng; Zhang, Yao; Wan, Chuan-Xing; Zhang, Li-Li

2016-12-01

The taxonomic position of a novel actinomycete, strain TRM 46250T, isolated from the sediment of a salt water beach at Baicheng, Xinjiang, China, was determined by a polyphasic approach. Strain TRM 46250T grew optimally in the presence of 2 % (w/v) NaCl and an optimum temperature range for growth of 28-37 °C. The whole-cell sugars of strain TRM 46250T were ribose, xylose, mannose and galactose. The diagnostic diamino acid was meso-diaminopimelic acid. The polar lipids were phosphatidylinositol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylmethyl ethanolamine and six unidentified phospholipids. The predominant menaquinones were MK-10, MK-10(H6) and MK-10(H8). The major fatty acids were 10-methyl C18 : 0, iso-C16 : 0, C16 : 0, iso-G C16 : 1 and C18 : 1ω9c. Based on morphological and chemotaxonomic characteristics the isolate was determined to belong to the genus Nocardiopsis. The phylogenetic tree based on its nearly complete 16S rRNA gene sequence (1493 nt) with those of representative strains showed that the strain consistently falls into a distinct phyletic line together with Nocardiopsis gilva YIM 90087T (97.68 % similarity) and a subclade consisting of Nocardiopsis composta KS9T (97.52 %), Nocardiopsis rosea YIM 90094T (97.44 %) and Nocardiopsis rhodophaea YIM 90096T (97.16 %). However, DNA-DNA hybridization studies between strain TRM 46250T and N. gilva YIM 90087T showed only 36.94 % relatedness. On the basis of these data, strain TRM 46250T should be designated as a representative of a novel species of the genus Nocardiopsis, for which the name Nocardiopsis akesuensis sp. nov. is proposed. The type strain is TRM 46250T (=CCTCC AA 2015027T=KCTC 39725T).

Surfactin, Iturin, and Fengycin Biosynthesis by Endophytic Bacillus sp. from Bacopa monnieri.

PubMed

Jasim, B; Sreelakshmi, K S; Mathew, Jyothis; Radhakrishnan, E K

2016-07-01

Endophytic microorganisms which are ubiquitously present in plants may colonize intracellularly or intercellularly without causing any diseases. By living within the unique chemical environment of a host plant, they produce a vast array of compounds with a wide range of biological activities. Because of this, natural products of endophytic origin have been exploited for antimicrobial, antiviral, anticancer, and antioxidant properties. Also, they can be considered to function as an efficient microbial barrier to protect plants from various pathogens. In the present study, endophytic bacterium BmB 9 with antifungal and antibacterial activity isolated from the stem tissue of Bacopa monnieri was studied for the molecular and chemical basis of its activity. PCR-based genome mining for various biosynthetic gene clusters proved the presence of surfactin, iturin, and type I polyketide synthase (PKS) genes in the isolate. The LC-MS/MS based analysis of the extract further confirmed the production of surfactin derivatives (M + H(+)-1008.6602, 1022.6755), iturin (M + H(+)-1043.5697), and fengycin (M + H(+)-1491.8195, 1477.8055) by the selected bacterial isolate. The 16S rDNA sequence similarity based analysis identified the isolate BmB 9 as Bacillus sp. with 100 % identity to Bacillus sp. LCF1 (KP257289).

The genus Nonomuraea: A review of a rare actinomycete taxon for novel metabolites.

PubMed

Sungthong, Rungroch; Nakaew, Nareeluk

2015-05-01

The genus Nonomuraea is a rare actinomycete taxon with a long taxonomic history, while its generic description was recently emended. The genus is less known among the rare actinomycete genera as its taxonomic position was revised several times. It can be found in diverse ecological niches, while most of its member species were isolated from soil samples. However, new trends to discover the genus in other habitats are increasing. Generic abundance of the genus was found to be dependent on geographical changes. Novel sources together with selective and invented isolation techniques might increase a chance to explore the genus and its novel candidates. Interestingly, some of its members have been revealed as a valuable source of novel metabolites for medical and industrial purposes. Broad-range of potent bioactive compounds including antimicrobial, anticancer, and antipsychotic substances, broad-spectrum antibiotics and biocatalysts can be synthesized by the genus. In order to investigate biosynthetic pathways of the bioactive compounds and self-resistant mechanisms to these compounds, the links from genes to metabolites have yet been needed for further discovery and biotechnological development of the genus Nonomuraea. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Isolation, plant colonization potential, and phenanthrene degradation performance of the endophytic bacterium Pseudomonas sp. Ph6-gfp

PubMed Central

Sun, Kai; Liu, Juan; Gao, Yanzheng; Jin, Li; Gu, Yujun; Wang, Wanqing

2014-01-01

This investigation provides a novel method of endophyte-aided removal of polycyclic aromatic hydrocarbons (PAHs) from plant bodies. A phenanthrene-degrading endophytic bacterium Pseudomonas sp. Ph6 was isolated from clover (Trifolium pratense L.) grown in a PAH-contaminated site. After being marked with the GFP gene, the colonization and distribution of strain Ph6-gfp was directly visualized in plant roots, stems, and leaves for the first time. After ryegrass (Lolium multiflorum Lam.) roots inoculation, strain Ph6-gfp actively and internally colonized plant roots and transferred vertically to the shoots. Ph6-gfp had a natural capacity to cope with phenanthrene in vitro and in planta. Ph6-gfp degraded 81.1% of phenanthrene (50 mg·L−1) in a culture solution within 15 days. The inoculation of plants with Ph6-gfp reduced the risks associated with plant phenanthrene contamination based on observations of decreased concentration, accumulation, and translocation factors of phenanthrene in ryegrass. Our results will have important ramifications in the assessment of the environmental risks of PAHs and in finding ways to circumvent plant PAH contamination. PMID:24964867

Analysis of endophytic fungi in roots of Santalum album Linn. and its host plant Kuhnia rosmarinifolia Vent.*

PubMed Central

Sun, Si-sheng; Chen, Xiao-mei; Guo, Shun-xing

2014-01-01

Santalum album Linn. is an evergreen and hemi-parasitic tree, the heartwood-sandalwood of which was used during a long history in traditional Chinese medicine. Kuhnia rosmarinifolia Vent. is a good host for 1- or 2-year-old growing S. album. The interaction between S. album and K. rosmarinifolia is still little known. Many studies have been carried out on a number of plants for identification and diversity of endophytes. In this study, in total 25 taxa of endophytic fungi were isolated from the roots of S. album and the roots of K. rosmarinifolia. The most frequently isolated genera were Penicillium sp. 1 and Fusarium sp. 1 in the roots of S. album and K. rosmarinifolia, respectively. S. album is a root parasite of K. rosmarinifolia. The interesting result is that they apparently do not share the same endophytic fungi isolates. This study for the first time explored the content of endophytic fungi from S. album and K. rosmarinifolia, which provides important information for further studies. PMID:24510703

Endophytic colonization and in planta nitrogen fixation by a diazotrophic Serratia sp. in rice.

PubMed

Sandhiya, G S; Sugitha, T C K; Balachandar, D; Kumar, K

2005-09-01

Nitrogen fixing endophytic Serratia sp. was isolated from rice and characterized. Re-colonization ability of Serratia sp. in the rice seedlings as endophyte was studied under laboratory condition. For detecting the re-colonization potential in the rice seedlings, Serratia sp. was marked with reporter genes (egfp and Kmr) using transposon mutagenesis. The conjugants were screened for re-colonization ability and presence of nif genes using PCR. Further, the influence of flavonoids and growth hormones on the endophytic colonization and in planta nitrogen fixation of Serratia was also investigated. The flavonoids, quercetin (3 microg/ml) and diadzein (2 microg/ml) significantly increased the re-colonization ability of the endophytic Serratia, whereas the growth hormones like IAA and NAA (5 microg/ml) reduced the endophytic colonization ability of Serratia sp. Similarly, the in planta nitrogen fixation by Serratia sp. in rice was significantly increased due to flavonoids. The inoculation of endophytic diazotrophs increased the plant biomass and biochemical constituents.

Exploring Arabidopsis thaliana Root Endophytes via Single-Cell Genomics

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

Lundberg, Derek; Woyke, Tanja; Tringe, Susannah

2014-03-19

Land plants grow in association with microbial communities both on their surfaces and inside the plant (endophytes). The relationships between microbes and their host can vary from pathogenic to mutualistic. Colonization of the endophyte compartment occurs in the presence of a sophisticated plant immune system, implying finely tuned discrimination of pathogens from mutualists and commensals. Despite the importance of the microbiome to the plant, relatively little is known about the specific interactions between plants and microbes, especially in the case of endophytes. The vast majority of microbes have not been grown in the lab, and thus one of the fewmore » ways of studying them is by examining their DNA. Although metagenomics is a powerful tool for examining microbial communities, its application to endophyte samples is technically difficult due to the presence of large amounts of host plant DNA in the sample. One method to address these difficulties is single-cell genomics where a single microbial cell is isolated from a sample, lysed, and its genome amplified by multiple displacement amplification (MDA) to produce enough DNA for genome sequencing. This produces a single-cell amplified genome (SAG). We have applied this technology to study the endophytic microbes in Arabidopsis thaliana roots. Extensive 16S gene profiling of the microbial communities in the roots of multiple inbred A. thaliana strains has identified 164 OTUs as being significantly enriched in all the root endophyte samples compared to their presence in bulk soil.« less

Synthetic polyester-hydrolyzing enzymes from thermophilic actinomycetes.

PubMed

Wei, Ren; Oeser, Thorsten; Zimmermann, Wolfgang

2014-01-01

Thermophilic actinomycetes produce enzymes capable of hydrolyzing synthetic polyesters such as polyethylene terephthalate (PET). In addition to carboxylesterases, which have hydrolytic activity predominantly against PET oligomers, esterases related to cutinases also hydrolyze synthetic polymers. The production of these enzymes by actinomycetes as well as their recombinant expression in heterologous hosts is described and their catalytic activity against polyester substrates is compared. Assays to analyze the enzymatic hydrolysis of synthetic polyesters are evaluated, and a kinetic model describing the enzymatic heterogeneous hydrolysis process is discussed. Structure-function and structure-stability relationships of actinomycete polyester hydrolases are compared based on molecular dynamics simulations and recently solved protein structures. In addition, recent progress in enhancing their activity and thermal stability by random or site-directed mutagenesis is presented. © 2014 Elsevier Inc. All rights reserved.

Bioactive steroids and sorbicillinoids isolated from the endophytic fungus Trichoderma sp. Xy24.

PubMed

Zhao, Jin-Lian; Zhang, Min; Liu, Ji-Mei; Tan, Zhen; Chen, Ri-Dao; Xie, Ke-Bo; Dai, Jun-Gui

2017-10-01

A new steroid glucoside (1), along with nine known steroids (2-10) and four known sorbicillinoids (11-14), were isolated from the endophytic fungus Trichoderma sp. Xy24. Their structures were elucidated on the basis of spectroscopic data analyses and by comparison with reported data. Compounds 3, 5-7, 9, 10, and 13 exhibited significant inhibitory effects on HIV-1 virus with IC 50 values ranging 1.9-9.3 μM; compounds 10, 13, and 14 showed potent inhibitory activity on LPS-induced NO production in BV2 microglia cells with inhibitory rates of 108.2, 100, and 75.1% at 10 μM, respectively. In addition, compound 10 displayed moderate cytotoxicity against BCG823 and HePG2 cell lines with IC 50 values of 11.1 and 17.7 μM, respectively.

Occurrence of Bacillus amyloliquefaciens as a systemic endophyte of vanilla orchids.

PubMed

White, James F; Torres, Mónica S; Sullivan, Raymond F; Jabbour, Rabih E; Chen, Qiang; Tadych, Mariusz; Irizarry, Ivelisse; Bergen, Marshall S; Havkin-Frenkel, Daphna; Belanger, Faith C

2014-11-01

We report the occurrence of Bacillus amyloliquefaciens in vanilla orchids (Vanilla phaeantha) and cultivated hybrid vanilla (V. planifolia × V. pompona) as a systemic bacterial endophyte. We determined with light microscopy and isolations that tissues of V. phaeantha and the cultivated hybrid were infected by a bacterial endophyte and that shoot meristems and stomatal areas of stems and leaves were densely colonized. We identified the endophyte as B. amyloliquefaciens using DNA sequence data. Since additional endophyte-free plants and seed of this orchid were not available, additional studies were performed on surrogate hosts Amaranthus caudatus, Ipomoea tricolor, and I. purpurea. Plants of A. caudatus inoculated with B. amyloliquefaciens demonstrated intracellular colonization of guard cells and other epidermal cells, confirming the pattern observed in the orchids. Isolations and histological studies suggest that the bacterium may penetrate deeply into developing plant tissues in shoot meristems, forming endospores in maturing tissues. B. amyloliquefaciens produced fungal inhibitors in culture. In controlled experiments using morning glory seedlings we showed that the bacterium promoted seedling growth and reduced seedling necrosis due to pathogens. We detected the gene for phosphopantetheinyl transferase (sfp), an enzyme in the pathway for production of antifungal lipopeptides, and purified the lipopeptide "surfactin" from cultures of the bacterium. We hypothesize that B. amyloliquefaciens is a robust endophyte and defensive mutualist of vanilla orchids. Whether the symbiosis between this bacterium and its hosts can be managed to protect vanilla crops from diseases is a question that should be evaluated in future research. © 2014 Wiley Periodicals, Inc.

Nonomuraea glycinis sp. nov., a novel actinomycete isolated from the root of black soya bean [Glycine max (L.) Merr].

PubMed

Li, Zhilei; Song, Wei; Zhao, Junwei; Zhuang, Xiaoxin; Zhao, Yue; Wang, Xiangjing; Xiang, Wensheng

2017-12-01

A novel actinomycete, designated strain NEAU-BB2C19 T , was isolated from the root of black soya bean [Glycine max (L.) Merr] collected from Harbin, Heilongjiang Province, China, and characterized using a polyphasic approach. The strain was an aerobic, Gram-stain-positive actinomycete that formed extensively branched substrate mycelium and aerial hyphae. The predominant menaquinones were MK-9(H2) and MK-9(H0). The major cellular fatty acid profile consisted of iso-C16 : 0, 10-methyl C17 : 0 and 10-methyl C18 : 0. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, hydroxy-phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside, phosphatidylglycerol and glycolipid. The DNA G+C content was 68.2±0.4 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NEAU-BB2C19 T should be assigned to the genus Nonomuraea and formed a distinct branch with its closest neighbour Nonomuraea guangzhouensis NEAU-ZJ3 T (98.75 % 16S rRNA gene sequence similarity). The morphological and chemotaxonomic properties of the strain were also consistent with those of members of the genus Nonomuraea. A combination of DNA-DNA hybridization results and some phenotypic characteristics indicated that strain NEAU-BB2C19 T could be clearly differentiated from its closest phylogenetic relative. Thus, the strain is concluded to represent a novel species of the genus Nonomuraea, for which the name Nonomuraea glycinis sp. nov. is proposed. The type strain is NEAU-BB2C19 T (=CGMCC 4.7430 T =DSM 104838 T ).

Biosynthetic potential of actinomycetes in brown forest soil on the eastern coast of the aegean sea

NASA Astrophysics Data System (ADS)

Shirokikh, I. G.; Shirokikh, A. A.

2017-11-01

The taxonomic and functional structures of the actinomycetal complex in the litter and upper horizon of the brown forest soil was studied in a Pinus brutia var. pendulifolia forest on the eastern coast of the Aegean Sea. The complex of actinomycetes included representatives of the Streptomyces and Micromonospora genera and oligosporus forms. Streptomycetes predominated (73.8%) in the soil, and micromonospores (66.7%) were dominants in the litter. Thirty isolates of ten Streptomyces species from five series and three sections prevailed. In the upper soil horizon, species of the Helvolo-Flavus Helvolus section predominated (48%); the S. felleus species occurred most frequently. Among the isolated cultures, the S. globisporus and S. sindenensis species capable to produce antitumor antibiotics were found. The testing of the antimicrobial activity of the natural isolates showed that five strains inhibit the growth of pathogenic Fusarium sp., Alternaria sp., Acremonium sp., and Bipolaris sorokiniana fungi. When testing the effect of streptomycetes on the production of cellulases, a high-efficient strain belonging to the S. noboritoensis species was revealed. All the streptomycetes isolated from the brown forest soil produced auxins at the rate of 7.8 to 19.7 μg of indole acetic acid/mL of the liquid medium in the presence of 200 mg/L of tryptophan. Twelve isolates of streptomycetes were transferred to the collection of biotechnologically promising cultures for studying their properties.

Diversity of endophytic Pseudomonas in Halimione portulacoides from metal(loid)-polluted salt marshes.

PubMed

Rocha, Jaqueline; Tacão, Marta; Fidalgo, Cátia; Alves, Artur; Henriques, Isabel

2016-07-01

Phytoremediation assisted by bacteria is seen as a promising alternative to reduce metal contamination in the environment. The main goal of this study was to characterize endophytic Pseudomonas isolated from Halimione portulacoides, a metal-accumulator plant, in salt marshes contaminated with metal(loid)s. Phylogenetic analysis based on 16S rRNA and gyrB genes showed that isolates affiliated with P. sabulinigri (n = 16), P. koreensis (n = 10), P. simiae (n = 5), P. seleniipraecipitans (n = 2), P. guineae (n = 2), P. migulae (n = 1), P. fragi (n = 1), P. xanthomarina (n = 1), and Pseudomonas sp. (n = 1). Most of these species have never been described as endophytic. The majority of the isolates were resistant to three or more metal(loid)s. Antibiotic resistance was frequent among the isolates but most likely related to species-intrinsic features. Common acquired antibiotic resistance genes and integrons were not detected. Plasmids were detected in 43.6 % of the isolates. Isolates that affiliated with different species shared the same plasmid profile but attempts to transfer metal resistance to receptor strains were not successful. Phosphate solubilization and IAA production were the most prevalent plant growth promoting traits, and 20 % of the isolates showed activity against phytopathogenic bacteria. Most isolates produced four or more extracellular enzymes. Preliminary results showed that two selected isolates promote Arabidopsis thaliana root elongation. Results highlight the diversity of endophytic Pseudomonas in H. portulacoides from contaminated sites and their potential to assist phytoremediation by acting as plant growth promoters and as environmental detoxifiers.

Fungal endophytes of Catharanthus roseus enhance vindoline content by modulating structural and regulatory genes related to terpenoid indole alkaloid biosynthesis

PubMed Central

Pandey, Shiv S.; Singh, Sucheta; Babu, C. S. Vivek; Shanker, Karuna; Srivastava, N. K.; Shukla, Ashutosh K.; Kalra, Alok

2016-01-01

Not much is known about the mechanism of endophyte-mediated induction of secondary metabolite production in Catharanthus roseus. In the present study two fungal endophytes, Curvularia sp. CATDLF5 and Choanephora infundibulifera CATDLF6 were isolated from the leaves of the plant that were found to enhance vindoline content by 229–403%. The isolated endophytes did not affect the primary metabolism of the plant as the maximum quantum efficiency of PSII, net CO2 assimilation, plant biomass and starch content of endophyte-inoculated plants was similar to endophyte-free control plants. Expression of terpenoid indole alkaloid (TIA) pathway genes, geraniol 10-hydroxylase (G10H), tryptophan decarboxylase (TDC), strictosidine synthase (STR), 16-hydoxytabersonine-O-methyltransferase (16OMT), desacetoxyvindoline-4-hydroxylase (D4H), deacetylvindoline-4-O-acetyltransferase (DAT) were upregulated in endophyte-inoculated plants. Endophyte inoculation upregulated the expression of the gene for transcriptional activator octadecanoid-responsive Catharanthus AP2-domain protein (ORCA3) and downregulated the expression of Cys2/His2-type zinc finger protein family transcriptional repressors (ZCTs). The gene for the vacuolar class III peroxidase (PRX1), responsible for coupling vindoline and catharanthine, was upregulated in endophyte-inoculated plants. These endophytes may enhance vindoline production by modulating the expression of key structural and regulatory genes of vindoline biosynthesis without affecting the primary metabolism of the host plant. PMID:27220774

Cultivable endophytic bacteria from leaf bases of Agave tequilana and their role as plant growth promoters

PubMed Central

Martínez-Rodríguez, Julia del C.; la Mora-Amutio, Marcela De; Plascencia-Correa, Luis A.; Audelo-Regalado, Esmeralda; Guardado, Francisco R.; Hernández-Sánchez, Elías; Peña-Ramírez, Yuri J.; Escalante, Adelfo; Beltrán-García, Miguel J.; Ogura, Tetsuya

2014-01-01

Agave tequilana Weber var. ‘Azul’ is grown for the production of tequila, inulin and syrup. Diverse bacteria inhabit plant tissues and play a crucial role for plant health and growth. In this study culturable endophytic bacteria were extracted from leaf bases of 100 healthy Agave tequilana plants. In plant tissue bacteria occurred at mean population densities of 3 million CFU/g of fresh plant tissue. Three hundred endophytic strains were isolated and 16s rDNA sequences grouped the bacteria into eight different taxa that shared high homology with other known sequences. Bacterial endophytes were identified as Acinectobacter sp., A. baumanii, A. bereziniae, Cronobacter sakazakii, Enterobacter hormaechei, Bacillus sp. Klebsiella oxytoca, Pseudomonas sp., Enterococcus casseliflavus, Leuconostoc mesenteroides subsp. mesenteroides and Gluconobacter oxydans. Isolates were confirmed to be plant growth promoting bacteria (PGPB) by their capacities for nitrogen fixation, auxin production, phosphate solubilization, or antagonism against Fusarium oxysporum AC132. E. casseliflavus JM47 and K. oxytoca JM26 secreted the highest concentrations of IAA. The endophyte Acinectobacter sp. JM58 exhibited the maximum values for nitrogen fixation and phosphate solubilization index (PSI). Inhibition of fungi was found in Pseudomonas sp. JM9p and K. oxytoca JM26. Bacterial endophytes show promise for use as bio-inoculants for agave cultivation. Use of endophytes to enhance cultivation of agave may be particularly important for plants produced by micropropagation techniques, where native endophytes may have been lost. PMID:25763038

Cultivable endophytic bacteria from leaf bases of Agave tequilana and their role as plant growth promoters.

PubMed

Martínez-Rodríguez, Julia del C; De la Mora-Amutio, Marcela; Plascencia-Correa, Luis A; Audelo-Regalado, Esmeralda; Guardado, Francisco R; Hernández-Sánchez, Elías; Peña-Ramírez, Yuri J; Escalante, Adelfo; Beltrán-García, Miguel J; Ogura, Tetsuya

2014-01-01

Agave tequilana Weber var. 'Azul' is grown for the production of tequila, inulin and syrup. Diverse bacteria inhabit plant tissues and play a crucial role for plant health and growth. In this study culturable endophytic bacteria were extracted from leaf bases of 100 healthy Agave tequilana plants. In plant tissue bacteria occurred at mean population densities of 3 million CFU/g of fresh plant tissue. Three hundred endophytic strains were isolated and 16s rDNA sequences grouped the bacteria into eight different taxa that shared high homology with other known sequences. Bacterial endophytes were identified as Acinectobacter sp., A. baumanii, A. bereziniae, Cronobacter sakazakii, Enterobacter hormaechei, Bacillus sp. Klebsiella oxytoca, Pseudomonas sp., Enterococcus casseliflavus, Leuconostoc mesenteroides subsp. mesenteroides and Gluconobacter oxydans. Isolates were confirmed to be plant growth promoting bacteria (PGPB) by their capacities for nitrogen fixation, auxin production, phosphate solubilization, or antagonism against Fusarium oxysporum AC132. E. casseliflavus JM47 and K. oxytoca JM26 secreted the highest concentrations of IAA. The endophyte Acinectobacter sp. JM58 exhibited the maximum values for nitrogen fixation and phosphate solubilization index (PSI). Inhibition of fungi was found in Pseudomonas sp. JM9p and K. oxytoca JM26. Bacterial endophytes show promise for use as bio-inoculants for agave cultivation. Use of endophytes to enhance cultivation of agave may be particularly important for plants produced by micropropagation techniques, where native endophytes may have been lost.

Investigation of Endophytic Bacterial Community in Supposedly Axenic Cultures of Pineapple and Orchids with Evidence on Abundant Intracellular Bacteria.

PubMed

Esposito-Polesi, Natalia Pimentel; de Abreu-Tarazi, Monita Fiori; de Almeida, Cristina Vieira; Tsai, Siu Mui; de Almeida, Marcílio

2017-01-01

Asepsis, defined as the absence of microbial contamination, is one of the most important requirements of plant micropropagation. In long-term micropropagated cultures, there may occasionally occur scattered microorganism growth in the culture medium. These microorganisms are common plant components and are known as latent endophytes. Thus, the aim of this research was to investigate the presence of endophytic bacteria in asymptomatic pineapple and orchid microplants, which were cultivated in three laboratories for 1 year. Isolation and characterization of bacterial isolates, PCR-DGGE from total genomic DNA of microplants and ultrastructural analysis of leaves were performed. In the culture-dependent technique, it was only possible to obtain bacterial isolates from pineapple microplants. In this case, the bacteria genera identified in the isolation technique were Bacillus, Acinetobacter, and Methylobacterium. The scanning electron microscopy and transmission electron microscopy (SEM and TEM) analyses revealed the presence of endophytic bacteria in intracellular spaces in the leaves of pineapple and orchid microplants, independent of the laboratory or cultivation protocol. Our results strongly indicate that there are endophytic bacterial communities inhabiting the microplants before initiation of the in vitro culture and that some of these endophytes persist in their latent form and can also grow in the culture medium even after long-term micropropagation, thus discarding the concept of "truly axenic plants."

Hydrocarbon degradation potential and plant growth-promoting activity of culturable endophytic bacteria of Lotus corniculatus and Oenothera biennis from a long-term polluted site.

PubMed

Pawlik, Małgorzata; Cania, Barbara; Thijs, Sofie; Vangronsveld, Jaco; Piotrowska-Seget, Zofia

2017-08-01

Many endophytic bacteria exert beneficial effects on their host, but still little is known about the bacteria associated with plants growing in areas heavily polluted by hydrocarbons. The aim of the study was characterization of culturable hydrocarbon-degrading endophytic bacteria associated with Lotus corniculatus L. and Oenothera biennis L. collected in long-term petroleum hydrocarbon-polluted site using culture-dependent and molecular approaches. A total of 26 hydrocarbon-degrading endophytes from these plants were isolated. Phylogenetic analyses classified the isolates into the phyla Proteobacteria and Actinobacteria. The majority of strains belonged to the genera Rhizobium, Pseudomonas, Stenotrophomonas, and Rhodococcus. More than 90% of the isolates could grow on medium with diesel oil, approximately 20% could use n-hexadecane as a sole carbon and energy source. PCR analysis revealed that 40% of the isolates possessed the P450 gene encoding for cytochrome P450-type alkane hydroxylase (CYP153). In in vitro tests, all endophytic strains demonstrated a wide range of plant growth-promoting traits such as production of indole-3-acetic acid, hydrogen cyanide, siderophores, and phosphate solubilization. More than 40% of the bacteria carried the gene encoding for the 1-aminocyclopropane-1-carboxylic acid deaminase (acdS). Our study shows that the diversity of endophytic bacterial communities in tested plants was different. The results revealed also that the investigated plants were colonized by endophytic bacteria possessing plant growth-promoting features and a clear potential to degrade hydrocarbons. The properties of isolated endophytes indicate that they have the high potential to improve phytoremediation of petroleum hydrocarbon-polluted soils.

Endophytic fungi from selected varieties of soybean (Glycine max L. Merr.) and corn (Zea mays L.) grown in an agricultural area of Argentina.

PubMed

Russo, María L; Pelizza, Sebastián A; Cabello, Marta N; Stenglein, Sebastián A; Vianna, María F; Scorsetti, Ana C

2016-01-01

Endophytic fungi are ubiquitous and live within host plants without causing any noticeable symptoms of disease. Little is known about the diversity and function of fungal endophytes in plants, particularly in economically important species. The aim of this study was to determine the identity and diversity of endophytic fungi in leaves, stems and roots of soybean and corn plants and to determine their infection frequencies. Plants were collected in six areas of the provinces of Buenos Aires and Entre Ríos (Argentina) two areas were selected for sampling corn and four for soybean. Leaf, stem and root samples were surface-sterilized, cut into 1cm(2) pieces using a sterile scalpel and aseptically transferred to plates containing potato dextrose agar plus antibiotics. The species were identified using both morphological and molecular data. Fungal endophyte colonization in soybean plants was influenced by tissue type and varieties whereas in corn plants only by tissue type. A greater number of endophytes were isolated from stem tissues than from leaves and root tissues in both species of plants. The most frequently isolated species in all soybean cultivars was Fusarium graminearum and the least isolated one was Scopulariopsis brevicaulis. Furthermore, the most frequently isolated species in corn plants was Aspergillus terreus whereas the least isolated one was Aspergillus flavus. These results could be relevant in the search for endophytic fungi isolates that could be of interest in the control of agricultural pests. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

The genome of the endophytic bacterium H. frisingense GSF30(T) identifies diverse strategies in the Herbaspirillum genus to interact with plants.

PubMed

Straub, Daniel; Rothballer, Michael; Hartmann, Anton; Ludewig, Uwe

2013-01-01

The diazotrophic, bacterial endophyte Herbaspirillum frisingense GSF30(T) has been identified in biomass grasses grown in temperate climate, including the highly nitrogen-efficient grass Miscanthus. Its genome was annotated and compared with related Herbaspirillum species from diverse habitats, including H. seropedicae, and further well-characterized endophytes. The analysis revealed that Herbaspirillum frisingense lacks a type III secretion system that is present in some related Herbaspirillum grass endophytes. Together with the lack of components of the type II secretion system, the genomic inventory indicates distinct interaction scenarios of endophytic Herbaspirillum strains with plants. Differences in respiration, carbon, nitrogen and cell wall metabolism among Herbaspirillum isolates partially correlate with their different habitats. Herbaspirillum frisingense is closely related to strains isolated from the rhizosphere of phragmites and from well water, but these lack nitrogen fixation and metabolism genes. Within grass endophytes, the high diversity in their genomic inventory suggests that even individual plant species provide distinct, highly diverse metabolic niches for successful endophyte-plant associations.

The genome of the endophytic bacterium H. frisingense GSF30T identifies diverse strategies in the Herbaspirillum genus to interact with plants

PubMed Central

Straub, Daniel; Rothballer, Michael; Hartmann, Anton; Ludewig, Uwe

2013-01-01

The diazotrophic, bacterial endophyte Herbaspirillum frisingense GSF30T has been identified in biomass grasses grown in temperate climate, including the highly nitrogen-efficient grass Miscanthus. Its genome was annotated and compared with related Herbaspirillum species from diverse habitats, including H. seropedicae, and further well-characterized endophytes. The analysis revealed that Herbaspirillum frisingense lacks a type III secretion system that is present in some related Herbaspirillum grass endophytes. Together with the lack of components of the type II secretion system, the genomic inventory indicates distinct interaction scenarios of endophytic Herbaspirillum strains with plants. Differences in respiration, carbon, nitrogen and cell wall metabolism among Herbaspirillum isolates partially correlate with their different habitats. Herbaspirillum frisingense is closely related to strains isolated from the rhizosphere of phragmites and from well water, but these lack nitrogen fixation and metabolism genes. Within grass endophytes, the high diversity in their genomic inventory suggests that even individual plant species provide distinct, highly diverse metabolic niches for successful endophyte-plant associations. PMID:23825472

Biodegradation of Trichloroethylene by an Endophyte of Hybrid Poplar

PubMed Central

Kang, Jun Won; Khan, Zareen

2012-01-01

We isolated and characterized a novel endophyte from hybrid poplar. This unique endophyte, identified as Enterobacter sp. strain PDN3, showed high tolerance to trichloroethylene (TCE). Without the addition of inducers, such as toluene or phenol, PDN3 rapidly reduced TCE levels in medium from 72.4 μM to 30.1 μM in 24 h with a concurrent release of 127 μM chloride ion, and nearly 80% of TCE (55.3 μM) was dechlorinated by PDN3 in 5 days with 166 μM chloride ion production, suggesting TCE degradation. PMID:22367087

Nodulation-dependent communities of culturable bacterial endophytes from stems of field-grown soybeans.

PubMed

Okubo, Takashi; Ikeda, Seishi; Kaneko, Takakazu; Eda, Shima; Mitsui, Hisayuki; Sato, Shusei; Tabata, Satoshi; Minamisawa, Kiwamu

2009-01-01

Endophytic bacteria (247 isolates) were randomly isolated from surface-sterilized stems of non-nodulated (Nod(-)), wild-type nodulated (Nod(+)), and hypernodulated (Nod(++)) soybeans (Glycine max [L.] Merr) on three agar media (R2A, nutrient agar, and potato dextrose agar). Their diversity was compared on the basis of 16S rRNA gene sequences. The phylogenetic composition depended on the soybean nodulation phenotype, although diversity indexes were not correlated with nodulation phenotype. The most abundant phylum throughout soybean lines tested was Proteobacteria (58-79%). Gammaproteobacteria was the dominant class (21-72%) with a group of Pseudomonas sp. significantly abundant in Nod(+) soybeans. A high abundance of Alphaproteobacteria was observed in Nod(-) soybeans, which was explained by the increase in bacterial isolates of the families Rhizobiaceae and Sphingomonadaceae. A far greater abundance of Firmicutes was observed in Nod(-) and Nod(++) mutant soybeans than in Nod(+) soybeans. An impact of culture media on the diversity of isolated endophytic bacteria was also observed: The highest diversity indexes were obtained on the R2A medium, which enabled us to access Alphaproteobacteria and other phyla more frequently. The above results indicated that the extent of nodulation changes the phylogenetic composition of culturable bacterial endophytes in soybean stems.

Cholinesterase inhibitor (Altenuene) from an endophytic fungus Alternaria alternata: optimization, purification and characterization.

PubMed

Bhagat, J; Kaur, A; Kaur, R; Yadav, A K; Sharma, V; Chadha, B S

2016-10-01

The aim of this study was to screen endophytic fungi isolated from Vinca rosea for their potential to produce acetylcholinesterase (AChE) inhibitors. Endophytic fungi isolated from V. rosea (Catharanthus roseus), were screened for AChE inhibitor production using Ellman's method. Maximum inhibition against AChE (78%) was observed in an isolate VS-10, identified to be Alternaria alternata on morphological and molecular basis. The isolate also inhibited butyrylcholinesterase (73%). Significant increase (1·3 fold) was achieved after optimization of process parameters using one variable at time approach. The inhibitor was purified using chromatographic techniques. The structure elucidation of the inhibitor was carried out using spectroscopic techniques and was identified to be 'altenuene'. The purified inhibitor possessed antioxidant potential as revealed by dot blot assay. The insecticidal potential of purified inhibitor was evaluated by feeding Spodoptora litura on diet amended with inhibitor. It evinced significant larval mortality. Endophytic A. alternata can serve as a source of dual cholinesterase inhibitor 'altenuene' with significant antioxidant and insecticidal activity. This is the first report on acetylcholinestearse inhibitory activity of altenuene. Alternaria alternata has the potential to produce a dual ChE inhibitor with antioxidant activity useful in the treatment of neurodegenerative disorders and in agriculture as biocontrol agent. © 2016 The Society for Applied Microbiology.

Aspergillus oryzae NRRL 35191 from coffee, a non-toxigenic endophyte with the ability to synthesize kojic acid

USDA-ARS?s Scientific Manuscript database

Aspergillus oryzae was isolated as an endophyte from coffee leaves and found to produce kojic acid in culture. When inoculated in cacao seedlings (Theobroma cacao L.), A. oryzae grew endophytically and synthesize kojic acid in planta. Cacao seedlings inoculated with A. oryzae produced higher levels...

Endophytic fungi associated with Monarda citriodora, an aromatic and medicinal plant and their biocontrol potential.

PubMed

Katoch, Meenu; Pull, Shipra

2017-12-01

The Food and Agriculture Organization has estimated that every year considerable losses of the food crops occur due to plant diseases. Although fungicides are extensively used for management of plant diseases, they are expensive and hazardous to the environment and human health. Alternatively, biological control is the safe way to overcome the effects of plant diseases and to sustain agriculture. Since Monarda citriodora Cerv. ex Lag. (Lamiaceae/Labiatae) is known for its antifungal properties, it was chosen for the study. The isolation of endophytic fungi from M. citriodora and assessing their biocontrol potential. The isolated endophytes were characterized using ITS-5.8 S rDNA sequencing. Their biocontrol potential was assessed using different antagonistic assays against major plant pathogens. Twenty-eight endophytes representing 11 genera were isolated, of which, around 82% endophytes showed biocontrol potential against plant pathogens. MC-2 L (Fusarium oxysporum), MC-14 F (F. oxysporum), MC-22 F (F. oxysporum) and MC-25 F (F. redolens) displayed significant antagonistic activity against all the tested pathogens. Interestingly, MC-10 L (Muscodor yucatanensis) completely inhibited the growth of Sclerotinia sp., Colletotrichum capsici, Aspergillus flavus and A. fumigatus in dual culture assay, whereas MC-8 L (A. oryzae) and MC-9 L (Penicillium commune) completely inhibited the growth of the Sclerotinia sp. in fumigation assay. Endophytes MC-2 L, MC-14 F, MC-22 F and MC-25 F could effectively be used to control broad range of phytopathogens, while MC-10 L, MC-8 L and MC-9 L could be used to control specific pathogens. Secondly, endophytes showing varying degrees of antagonism in different assays represented the chemo-diversity not only as promising biocontrol agents but also as a resource of defensive and bioactive metabolites.

Genome sequencing reveals complex secondary metabolome in themarine actinomycete Salinispora tropica

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

Udwary, Daniel W.; Zeigler, Lisa; Asolkar, Ratnakar

2007-05-01

Recent fermentation studies have identified actinomycetes ofthe marine-dwelling genus Salinispora as prolific natural productproducers. To further evaluate their biosynthetic potential, we analyzedall identifiable secondary natural product gene clusters from therecently sequenced 5,184,724 bp S. tropica CNB-440 circular genome. Ouranalysis shows that biosynthetic potential meets or exceeds that shown byprevious Streptomyces genome sequences as well as other naturalproduct-producing actinomycetes. The S. tropica genome features ninepolyketide synthase systems of every known formally classified family,non-ribosomal peptide synthetases and several hybrid clusters. While afew clusters appear to encode molecules previously identified inStreptomyces species,the majority of the 15 biosynthetic loci are novel.Specific chemical information aboutmore » putative and observed natural productmolecules is presented and discussed. In addition, our bioinformaticanalysis was critical for the structure elucidation of the novelpolyenemacrolactam salinilactam A. This study demonstrates the potentialfor genomic analysis to complement and strengthen traditional naturalproduct isolation studies and firmly establishes the genus Salinispora asa rich source of novel drug-like molecules.« less

Fungal Endophyte Diversity and Bioactivity in the Indian Medicinal Plant Ocimum sanctum Linn

PubMed Central

Chowdhary, Kanika; Kaushik, Nutan

2015-01-01

Endophytic mycopopulation isolated from India’s Queen of herbs Tulsi (Ocimum sanctum) were explored and investigated for their diversity and antiphytopathogenic activity against widespread plant pathogens Botrytis cinerea, Sclerotinia sclerotiorum, Rhizoctonia solani and Fusarium oxysporum. 90 fungal isolates, representing 17 genera were recovered from 313 disease-free and surface sterilised plant segments (leaf and stem tissues) from three different geographic locations (Delhi, Hyderabad and Mukteshwar) during distinct sampling times in consequent years 2010 and 2011 in India. Fungal endophytes were subjected to molecular identification based on rDNA ITS sequence analysis. Plant pathogens such as F. verticillioides, B. maydis, C. coarctatum, R. bataticola, Hypoxylon sp., Diaporthe phaseolorum, Alternaria tenuissima and A. alternata have occurred as endophyte only during second sampling (second sampling in 2011) in the present study. Bi-plot generated by principal component analysis suggested tissue specificity of certain fungal endophytes. Dendrogram revealed species abundance as a function of mean temperature of the location at the time of sampling. Shannon diversity in the first collection is highest in Hyderabad leaf tissues (H' = 1.907) whereas in second collection it was highest from leaf tissues of Delhi (H' = 1.846). Mukteshwar (altitude: 7500 feet) reported least isolation rate in second collection. Nearly 23% of the total fungal isolates were considered as potent biocontrol agent. Hexane extract of M. phaseolina recovered from Hyderabad in first collection demonstrated highest activity against S. sclerotiorum with IC50 value of 0.38 mg/ml. Additionally, its components 2H-pyran-2-one, 5,6-dihydro-6-pentyl and palmitic acid, methyl ester as reported by GC-MS Chromatogram upon evaluation for their antiphytopathogenic activity exhibited IC50 value of 1.002 and 0.662 against respectively S. sclerotiorum indicating their significant role in

VIT-CMJ2: Endophyte of Agaricus bisporus in Production of Bioactive Compounds.

PubMed

Gautam, Chandan Kumar; Madhav, Mukund; Sinha, Astha; Jabez Osborne, William

2016-06-01

Agaricus bisporus is an edible basidiomycete fungus. Both the body and the mycelium contain compounds comprising a wide range of antimicrobial molecules, contributing in improvement of immunity and tumor-retardation. The presence of endophytes capable of producing bioactive compounds was investigated in Agaricus bisporus . Endophytes from Agaricus bisporus was isolated on LB agar. The obtained isolates were characterized morphologically and biochemically. Further 16S rRNA sequencing was implemented for molecular analysis of isolates. The isolate was mass produced and the bioactive compounds were extracted using ethyl acetate, chloroform and hexane. Agar well diffusion method was carried out to seek the potential of any antimicrobial activity of the crude bioactive compounds against known pathogens. GC-MS and FT-IR analysis were performed for the identification of bioactive compounds. VIT-CMJ2 was identified as Enterobacter sp. as revealed by 16S rRNA sequencing. Chloroform extract of VIT-CMJ2 showed a maximum zone of inhibition of 19 mm against Salmonella typhi followed by hexane and ethyl acetate extracts. The GC-MS analysis revealed the presence of several bioactive compounds having effective antimicrobial activity like butyl ester, Behenicalcohol, S , S-dioxide derivatives and some others which were later confirmed by FT-IR spectral stretches. The present study shows the insight on the way endophytes interact with Agaricus bisporus ; thereby improving the nutritional profile.

Methods for isolation of marine-derived endophytic fungi and their bioactive secondary products.

PubMed

Kjer, Julia; Debbab, Abdessamad; Aly, Amal H; Proksch, Peter

2010-03-01

Marine-derived fungi have been shown in recent years to produce a plethora of new bioactive secondary metabolites, some of them featuring new carbon frameworks hitherto unprecedented in nature. These compounds are of interest as new lead structures for medicine as well as for plant protection. The aim of this protocol is to give a detailed description of methods useful for the isolation and cultivation of fungi associated with various marine organisms (sponges, algae and mangrove plants) for the extraction, characterization and structure elucidation of biologically active secondary metabolites produced by these marine-derived endophytic fungi, and for the preliminary evaluation of their pharmacological properties based on rapid 'in house' screening systems. Some results exemplifying the positive outcomes of the protocol are given at the end. From sampling in marine environment to completion of the structure elucidation and bioactivity screening, a period of at least 3 months has to be scheduled.

Diversity of endophytic fungal and bacterial communities in Ilex paraguariensis grown under field conditions.

PubMed

Pérez, María Laura; Collavino, Mónica Mariana; Sansberro, Pedro Alfonso; Mroginski, Luis Amado; Galdeano, Ernestina

2016-04-01

The composition and diversity of the endophytic community associated with yerba mate (Ilex paraguariensis) was investigated using culture-depending methods. Fungi were identified based on their micromorphological characteristics and internal transcribed spacer rDNA sequence analysis; for bacteria 16S rDNA sequence analysis was used. Fungal and bacterial diversity did not show significant differences between organ age. The highest fungal diversity was registered during fall season and the lowest in winter. Bacterial diversity was higher in stems and increased from summer to winter, in contrast with leaves, which decreased. The most frequently isolated fungus was Fusarium, followed by Colletotrichum; they were both present in all the sampling seasons and organ types assayed. Actinobacteria represented 57.5 % of all bacterial isolates. The most dominant bacterial taxa were Curtobacterium and Microbacterium. Other bacteria frequently found were Methylobacterium, Sphingomonas, Herbiconiux and Bacillus. Nitrogen fixation and phosphate solubilization activity, ACC deaminase production and antagonism against plant fungal pathogens were assayed in endophytic bacterial strains. In the case of fungi, strains of Trichoderma, Penicillium and Aspergillus were assayed for antagonism against pathogenic Fusarium sp. All microbial isolates assayed showed at least one growth promoting activity. Strains of Bacillus, Pantoea, Curtobacterium, Methylobacterium, Brevundimonas and Paenibacillus had at least two growth-promoting activities, and Bacillus, Paenibacillus and the three endophytic fungi showed high antagonistic activity against Fusarium sp. In this work we have made a wide study of the culturable endophytic community within yerba mate plants and found that several microbial isolates could be considered as potential inoculants useful for improving yerba mate production.

Characterization of community structure of culturable endophytic fungi in sweet cherry composite trees and their growth-retarding effect against pathogens.

PubMed

Haddadderafshi, Neda; Pósa, Tímea Borbála; Péter, Gábor; Gáspár, László; Ladányi, Márta; Hrotkó, Károly; Lukács, Noémi; Halász, Krisztián

2016-09-01

Endophytic fungi have the potential to protect their host plants in stress situations. Characterizing the ecology and complex interaction between these endophytes and their host plants is therefore of great practical importance, particularly in horticultural plants. Among horticultural plants, fruit trees form a special category because of their longevity and because they are composites of rootstock and scion, which often belong to different plant species. Here we present the first characterization of culturable endophytic fungal community of sweet cherry. Samples from the Hungarian cultivar 'Petrus' grafted on 11 different rootstocks were collected in autumn and in spring in a bearing orchard and the dependence of colonization rate and endophyte diversity on rootstock, organ and season was analysed. On the basis of their ITS sequences 26 fungal operational taxonomic units were identified at least down to the genus level. The dominant genus, comprising more than 50% of all isolates, was Alternaria, followed by different Fusarium and Epicoccum species. We observed some organ-specificity amongst endophytes, and organs showed more sizeable differences in colonization rates and endophyte diversity than rootstocks. Most dynamic endophyte populations, strongly influenced by environmental conditions and crop management, were observed in leaves. The potential of selected endophytes to confer protection against Monilinia laxa was also analysed and 7 isolates were found to inhibit the growth of this pathogen in vitro.

Antileukemic alpha-pyrone derivatives from the endophytic fungus Alternaria phragmospora

USDA-ARS?s Scientific Manuscript database

Four new (1–4) and two known (5 and 6)a-pyrone derivatives have been isolated from Alternaria phragmospora, an endophytic fungus from Vinca rosea, leaves. The isolated compounds were chemically identi'ed to be 5-butyl-4-methoxy-6-methyl-2H-pyran-2-one (2) 5-butyl-6-(hydroxymethyl)-4-methoxy-2H-py...

Potential of Endophytic Bacterium Paenibacillus sp. PHE-3 Isolated from Plantago asiatica L. for Reduction of PAH Contamination in Plant Tissues

PubMed Central

Zhu, Xuezhu; Jin, Li; Sun, Kai; Li, Shuang; Ling, Wanting; Li, Xuelin

2016-01-01

Endophytes are ubiquitous in plants, and they may have a natural capacity to biodegrade polycyclic aromatic hydrocarbons (PAHs). In our study, a phenanthrene-degrading endophytic Paenibacillus sp. PHE-3 was isolated from P. asiatica L. grown in a PAH-contaminated site. The effects of environmental variables on phenanthrene biodegradation by strain PHE-3 were studied, and the ability of strain PHE-3 to use high molecular weight PAH (HMW-PAH) as a sole carbon source was also evaluated. Our results indicated that pH value of 4.0–8.0, temperature of 30 °C–42 °C, initial phenanthrene concentration less than 100 mg·L−1, and some additional nutrients are favorable for the biodegradation of phenanthrene by strain PHE-3. The maximum biodegradation efficiency of phenanthrene was achieved at 99.9% after 84 h cultivation with additional glutamate. Moreover, the phenanthrene biodegradation by strain PHE-3 was positively correlated with the catechol 2,3-dioxygenase activity (ρ = 0.981, p < 0.05), suggesting that strain PHE-3 had the capability of degrading HMW-PAHs. In the presence of other 2-, 3-ringed PAHs, strain PHE-3 effectively degraded HMW-PAHs through co-metabolism. The results of this study are beneficial in that the re-colonization potential and PAH degradation performance of endophytic Paenibacillus sp. PHE-3 may be applied towards reducing PAH contamination in plants. PMID:27347988

Deciphering endophyte behaviour: the link between endophyte biology and efficacious biological control agents.

PubMed

Card, Stuart; Johnson, Linda; Teasdale, Suliana; Caradus, John

2016-08-01

Endophytes associate with the majority of plant species found in natural and managed ecosystems. They are regarded as extremely important plant partners that provide improved stress tolerance to the host compared with plants that lack this symbiosis. Fossil records of endophytes date back more than 400 million years, implicating these microorganisms in host plant adaptation to habitat transitions. However, it is only recently that endophytes, and their bioactive products, have received meaningful attention from the scientific community. The benefits some endophytes can confer on their hosts include plant growth promotion and survival through the inhibition of pathogenic microorganisms and invertebrate pests, the removal of soil contaminants, improved tolerance of low fertility soils, and increased tolerance of extreme temperatures and low water availability. Endophytes are extremely diverse and can exhibit many different biological behaviours. Not all endophyte technologies have been successfully commercialised. Of interest in the development of the next generation of plant protection products is how much of this is due to the biology of the particular endophytic microorganism. In this review, we highlight selected case studies of endophytes and discuss their lifestyles and behavioural traits, and discuss how these factors contribute towards their effectiveness as biological control agents. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Molecular phylogeny, diversity and bioprospecting of endophytic fungi associated with wild ethnomedicinal North American plant Echinacea purpurea (Asteraceae)

USDA-ARS?s Scientific Manuscript database

The endophytic fungal community associated with the wild ethnomedicinal North American plant Echinacea purpurea was investigated as well as its potential for providing antifungal compounds against plant pathogenic fungi. A total of 233 endophytic fungal isolates were obtained and classified into 42 ...

Biodegradation of Polyester Polyurethane by Endophytic Fungi▿

PubMed Central

Russell, Jonathan R.; Huang, Jeffrey; Anand, Pria; Kucera, Kaury; Sandoval, Amanda G.; Dantzler, Kathleen W.; Hickman, DaShawn; Jee, Justin; Kimovec, Farrah M.; Koppstein, David; Marks, Daniel H.; Mittermiller, Paul A.; Núñez, Salvador Joel; Santiago, Marina; Townes, Maria A.; Vishnevetsky, Michael; Williams, Neely E.; Vargas, Mario Percy Núñez; Boulanger, Lori-Ann; Bascom-Slack, Carol; Strobel, Scott A.

2011-01-01

Bioremediation is an important approach to waste reduction that relies on biological processes to break down a variety of pollutants. This is made possible by the vast metabolic diversity of the microbial world. To explore this diversity for the breakdown of plastic, we screened several dozen endophytic fungi for their ability to degrade the synthetic polymer polyester polyurethane (PUR). Several organisms demonstrated the ability to efficiently degrade PUR in both solid and liquid suspensions. Particularly robust activity was observed among several isolates in the genus Pestalotiopsis, although it was not a universal feature of this genus. Two Pestalotiopsis microspora isolates were uniquely able to grow on PUR as the sole carbon source under both aerobic and anaerobic conditions. Molecular characterization of this activity suggests that a serine hydrolase is responsible for degradation of PUR. The broad distribution of activity observed and the unprecedented case of anaerobic growth using PUR as the sole carbon source suggest that endophytes are a promising source of biodiversity from which to screen for metabolic properties useful for bioremediation. PMID:21764951

Biodegradation of polyester polyurethane by endophytic fungi.

PubMed

Russell, Jonathan R; Huang, Jeffrey; Anand, Pria; Kucera, Kaury; Sandoval, Amanda G; Dantzler, Kathleen W; Hickman, DaShawn; Jee, Justin; Kimovec, Farrah M; Koppstein, David; Marks, Daniel H; Mittermiller, Paul A; Núñez, Salvador Joel; Santiago, Marina; Townes, Maria A; Vishnevetsky, Michael; Williams, Neely E; Vargas, Mario Percy Núñez; Boulanger, Lori-Ann; Bascom-Slack, Carol; Strobel, Scott A

2011-09-01

Bioremediation is an important approach to waste reduction that relies on biological processes to break down a variety of pollutants. This is made possible by the vast metabolic diversity of the microbial world. To explore this diversity for the breakdown of plastic, we screened several dozen endophytic fungi for their ability to degrade the synthetic polymer polyester polyurethane (PUR). Several organisms demonstrated the ability to efficiently degrade PUR in both solid and liquid suspensions. Particularly robust activity was observed among several isolates in the genus Pestalotiopsis, although it was not a universal feature of this genus. Two Pestalotiopsis microspora isolates were uniquely able to grow on PUR as the sole carbon source under both aerobic and anaerobic conditions. Molecular characterization of this activity suggests that a serine hydrolase is responsible for degradation of PUR. The broad distribution of activity observed and the unprecedented case of anaerobic growth using PUR as the sole carbon source suggest that endophytes are a promising source of biodiversity from which to screen for metabolic properties useful for bioremediation.

Induction of apoptosis against cancer cell lines by four ascomycetes (endophytes) from Malaysian rainforest.

PubMed

Hazalin, Nurul Aqmar Mohamad Nor; Ramasamy, Kalavathy; Lim, Siong Meng; Cole, Anthony L J; Majeed, Abu Bakar Abdul

2012-05-15

Endophytic fungi have been shown to be a promising source of biologically active natural products. In the present study, extracts of four endophytic fungi isolated from plants of the National Park, Pahang were evaluated for their cytotoxic activity and the nature of their active compounds determined. Those extracts exhibiting activity with IC(50) values less than 17 μg/ml against HCT116, MCF-7 and K562 cell lines were shown to induce apoptosis in these cell lines. Molecular analysis, based on sequences of the rDNA internal transcribed spacers ITS1 and ITS4, revealed all four endophytic fungi to be ascomycetes: three sordariomycetes and a dothideomycete. Six known compounds, cytochalasin J, dechlorogriseofulvin, demethylharzianic-acid, griseofulvin, harzianic acid and 2-hexylidene-3-methyl-succinic acid were identified from a rapid dereplication technique for fungal metabolites using an in-house UV library. The results from the present study suggest the potential of endophytic fungi as cytotoxic agents, and there is an indication that the isolates contain bioactive compounds that mainly kill cancer cells by apoptosis. Copyright © 2012 Elsevier GmbH. All rights reserved.

Endophytic fungal diversity in Theobroma cacao (cacao) and T. grandiflorum (cupuaçu) trees and their potential for growth promotion and biocontrol of black-pod disease.

PubMed

Hanada, Rogério Eiji; Pomella, Alan William V; Costa, Heron Salazar; Bezerra, José Luiz; Loguercio, Leandro L; Pereira, José O

2010-01-01

The endophytic niches of plants are a rich source of microbes that can directly and indirectly promote plant protection, growth and development. The diversity of culturable endophytic fungi from stems and branches of Theobroma cacao (cacao) and Theobroma grandiflorum (cupuaçu) trees growing in the Amazon region of Brazil was assessed. The collection of fungal endophytic isolates obtained was applied in field experiments to evaluate their potential as biocontrol agents against Phytophthora palmivora, the causal agent of the black-pod rot disease of cacao, one of the most important pathogens in cocoa-producing regions worldwide. The isolated endophytic fungi from 60 traditional, farmer-planted, healthy cacao and 10 cupuaçu plants were cultured in PDA under conditions inducing sporulation. Isolates were classified based upon the morphological characteristics of their cultures and reproductive structures. Spore suspensions from a total of 103 isolates that could be classified at least up to genus level were tested against P. palmivora in pods attached to cacao trees in the field. Results indicated that ∼70% of isolates showed biocontrol effects to a certain extent, suggesting that culturable endophytic fungal biodiversity in this system is of a mostly mutualistic type of interaction with the host. Eight isolates from genera Trichoderma (reference isolate), Pestalotiopsis, Curvularia, Tolypocladium and Fusarium showed the highest level of activity against the pathogen, and were further characterized. All demonstrated their endophytic nature by colonizing axenic cacao plantlets, and confirmed their biocontrol activity on attached pods trials by showing significant decrease in disease severity in relation to the positive control. None, however, showed detectable growth-promotion effects. Aspects related to endophytic biodiversity and host-pathogen-endophyte interactions in the environment of this study were discussed on the context of developing sustainable strategies

Secondary metabolites from fungal endophytes of Solanum nigrum.

PubMed

El-Hawary, Seham S; Sayed, Ahmed M; Rateb, Mostafa E; Bakeer, Walid; AbouZid, Sameh F; Mohammed, Rabab

2017-11-01

Three endophytic fungi, Aspergillus sp. (SNFSt), Aspergillus sp. (SNFL) and Lasiodiplodia theobromae (SNFF) were isolated from stems, leaves and fruits of Solanum nigrum L, respectively. The static fermentation of the three fungal strains led to the characterization of nine known metabolites (1-9) using HRESIMS and NMR analyses.

Antimicrobial Potential of Endophytic Fungi Derived from Three Seagrass Species: Cymodocea serrulata, Halophila ovalis and Thalassia hemprichii

PubMed Central

Supaphon, Preuttiporn; Phongpaichit, Souwalak; Rukachaisirikul, Vatcharin; Sakayaroj, Jariya

2013-01-01

Endophytic fungi from three commonly found seagrasses in southern Thailand were explored for their ability to produce antimicrobial metabolites. One hundred and sixty endophytic fungi derived from Cymodocea serrulata (Family Cymodoceaceae), Halophila ovalis and Thalassia hemprichii (Family Hydrocharitaceae) were screened for production of antimicrobial compounds by a colorimetric broth microdilution test against ten human pathogenic microorganisms including Staphylococcus aureus ATCC 25923, a clinical isolate of methicillin-resistant S. aureus, Escherichia coli ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Candida albicans ATCC 90028 and NCPF 3153, Cryptococcus neoformans ATCC 90112 and ATCC 90113 and clinical isolates of Microsporum gypseum and Penicillium marneffei . Sixty-nine percent of the isolates exhibited antimicrobial activity against at least one test strain. Antifungal activity was more pronounced than antibacterial activity. Among the active fungi, seven isolates including Hypocreales sp. PSU-ES26 from C . serrulata , Trichoderma spp. PSU-ES8 and PSU-ES38 from H . ovalis , and Penicillium sp. PSU-ES43, Fusarium sp. PSU-ES73, Stephanonectria sp. PSU-ES172 and an unidentified endophyte PSU-ES190 from T . hemprichii exhibited strong antimicrobial activity against human pathogens with minimum inhibitory concentrations (MIC) of less than 10 µg/ml. The inhibitory extracts at concentrations of 4 times their MIC destroyed the targeted cells as observed by scanning electron microscopy. These results showed the antimicrobial potential of extracts from endophytic fungi from seagrasses. PMID:23977310

Antimicrobial potential of endophytic fungi derived from three seagrass species: Cymodocea serrulata, Halophila ovalis and Thalassia hemprichii.

PubMed

Supaphon, Preuttiporn; Phongpaichit, Souwalak; Rukachaisirikul, Vatcharin; Sakayaroj, Jariya

2013-01-01

Endophytic fungi from three commonly found seagrasses in southern Thailand were explored for their ability to produce antimicrobial metabolites. One hundred and sixty endophytic fungi derived from Cymodoceaserrulata (Family Cymodoceaceae), Halophilaovalis and Thalassiahemprichii (Family Hydrocharitaceae) were screened for production of antimicrobial compounds by a colorimetric broth microdilution test against ten human pathogenic microorganisms including Staphylococcus aureus ATCC 25923, a clinical isolate of methicillin-resistant S. aureus, Escherichia coli ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Candida albicans ATCC 90028 and NCPF 3153, Cryptococcus neoformans ATCC 90112 and ATCC 90113 and clinical isolates of Microsporumgypseum and Penicilliummarneffei. Sixty-nine percent of the isolates exhibited antimicrobial activity against at least one test strain. Antifungal activity was more pronounced than antibacterial activity. Among the active fungi, seven isolates including Hypocreales sp. PSU-ES26 from C. serrulata, Trichoderma spp. PSU-ES8 and PSU-ES38 from H. ovalis, and Penicillium sp. PSU-ES43, Fusarium sp. PSU-ES73, Stephanonectria sp. PSU-ES172 and an unidentified endophyte PSU-ES190 from T. hemprichii exhibited strong antimicrobial activity against human pathogens with minimum inhibitory concentrations (MIC) of less than 10 µg/ml. The inhibitory extracts at concentrations of 4 times their MIC destroyed the targeted cells as observed by scanning electron microscopy. These results showed the antimicrobial potential of extracts from endophytic fungi from seagrasses.

Conservation and Diversity of Seed Associated Endophytes in Zea across Boundaries of Evolution, Ethnography and Ecology

PubMed Central

Johnston-Monje, David; Raizada, Manish N.

2011-01-01

Endophytes are non-pathogenic microbes living inside plants. We asked whether endophytic species were conserved in the agriculturally important plant genus Zea as it became domesticated from its wild ancestors (teosinte) to modern maize (corn) and moved from Mexico to Canada. Kernels from populations of four different teosintes and 10 different maize varieties were screened for endophytic bacteria by culturing, cloning and DNA fingerprinting using terminal restriction fragment length polymorphism (TRFLP) of 16S rDNA. Principle component analysis of TRFLP data showed that seed endophyte community composition varied in relation to plant host phylogeny. However, there was a core microbiota of endophytes that was conserved in Zea seeds across boundaries of evolution, ethnography and ecology. The majority of seed endophytes in the wild ancestor persist today in domesticated maize, though ancient selection against the hard fruitcase surrounding seeds may have altered the abundance of endophytes. Four TRFLP signals including two predicted to represent Clostridium and Paenibacillus species were conserved across all Zea genotypes, while culturing showed that Enterobacter, Methylobacteria, Pantoea and Pseudomonas species were widespread, with γ-proteobacteria being the prevalent class. Twenty-six different genera were cultured, and these were evaluated for their ability to stimulate plant growth, grow on nitrogen-free media, solubilize phosphate, sequester iron, secrete RNAse, antagonize pathogens, catabolize the precursor of ethylene, produce auxin and acetoin/butanediol. Of these traits, phosphate solubilization and production of acetoin/butanediol were the most commonly observed. An isolate from the giant Mexican landrace Mixteco, with 100% identity to Burkholderia phytofirmans, significantly promoted shoot potato biomass. GFP tagging and maize stem injection confirmed that several seed endophytes could spread systemically through the plant. One seed isolate

Conservation and diversity of seed associated endophytes in Zea across boundaries of evolution, ethnography and ecology.

PubMed

Johnston-Monje, David; Raizada, Manish N

2011-01-01

Endophytes are non-pathogenic microbes living inside plants. We asked whether endophytic species were conserved in the agriculturally important plant genus Zea as it became domesticated from its wild ancestors (teosinte) to modern maize (corn) and moved from Mexico to Canada. Kernels from populations of four different teosintes and 10 different maize varieties were screened for endophytic bacteria by culturing, cloning and DNA fingerprinting using terminal restriction fragment length polymorphism (TRFLP) of 16S rDNA. Principle component analysis of TRFLP data showed that seed endophyte community composition varied in relation to plant host phylogeny. However, there was a core microbiota of endophytes that was conserved in Zea seeds across boundaries of evolution, ethnography and ecology. The majority of seed endophytes in the wild ancestor persist today in domesticated maize, though ancient selection against the hard fruitcase surrounding seeds may have altered the abundance of endophytes. Four TRFLP signals including two predicted to represent Clostridium and Paenibacillus species were conserved across all Zea genotypes, while culturing showed that Enterobacter, Methylobacteria, Pantoea and Pseudomonas species were widespread, with γ-proteobacteria being the prevalent class. Twenty-six different genera were cultured, and these were evaluated for their ability to stimulate plant growth, grow on nitrogen-free media, solubilize phosphate, sequester iron, secrete RNAse, antagonize pathogens, catabolize the precursor of ethylene, produce auxin and acetoin/butanediol. Of these traits, phosphate solubilization and production of acetoin/butanediol were the most commonly observed. An isolate from the giant Mexican landrace Mixteco, with 100% identity to Burkholderia phytofirmans, significantly promoted shoot potato biomass. GFP tagging and maize stem injection confirmed that several seed endophytes could spread systemically through the plant. One seed isolate

Diversity of fungal endophytes in recent and ancient wheat ancestors Triticum dicoccoides and Aegilops sharonensis.

PubMed

Ofek-Lalzar, Maya; Gur, Yonatan; Ben-Moshe, Sapir; Sharon, Or; Kosman, Evsey; Mochli, Elad; Sharon, Amir

2016-10-01

Endophytes have profound impacts on plants, including beneficial effects on agriculturally important traits. We hypothesized that endophytes in wild plants include beneficial endophytes that are absent or underrepresented in domesticated crops. In this work, we studied the structure of endophyte communities in wheat-related grasses, Triticum dicoccoides and Aegilops sharonensis, and compared it to an endophyte community from wheat (T. aeastivum). Endophytes were isolated by cultivation and by cultivation-independent methods. In total, 514 intergenic spacer region sequences from single cultures were analyzed. Categorization at 97% sequence similarity resulted in 67 operational taxonomic units (OTUs) that were evenly distributed between the different plant species. A narrow core community of Alternaria spp. was found in all samples, but each plant species also contained a significant portion of unique endophytes. The cultivation-independent analysis identified a larger number of OTUs than the cultivation method, half of which were singletons or doubletons. For OTUs with a relative abundance >0.5%, similar numbers were obtained by both methods. Collectively, our data show that wild grass relatives of wheat contain a wealth of taxonomically diverse fungal endophytes that are not found in modern wheat, some of which belong to taxa with known beneficial effects. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Endophytic fungi occurring in fennel, lettuce, chicory, and celery--commercial crops in southern Italy.

PubMed

D'Amico, Margherita; Frisullo, Salvatore; Cirulli, Matteo

2008-01-01

The occurrence of endophytic fungi in fennel, lettuce, chicory, and celery crops was investigated in southern Italy. A total of 186 symptomless plants was randomly collected and sampled at the stage of commercial ripeness. Fungal species of Acremonium, Alternaria, Fusarium, and Plectosporium were detected in all four crops; Plectosporium tabacinum was the most common in all crop species and surveyed sites. The effect of eight endophytic isolates (five belonging to Plectosporium tabacinum and three to three species of Acremonium) inoculated on lettuce plants grown in gnotobiosis was assessed by recording plant height, root length and dry weight, collar diameter, root necrosis, and leaf yellowing. P. tabacinum and three species of Acremonium, inoculated on gnotobiotically grown lettuce plants, showed pathogenic activity that varied with the fungal isolate. Lettuce plants inoculated with the isolates Ak of Acremonium kiliense, Ac of Acremonium cucurbitacearum, and P35 of P. tabacinum showed an increased root growth, compared to the non-inoculated control. The high frequency of P. tabacinum isolation recorded in lettuce plants collected in Bari and Metaponto, and in fennel plants from Foggia agricultural districts, suggests a relationship not only between a crop species and P. tabacinum, but also between the occurrence of the endophyte and the crop rotation history of the soil.

Metabolomic Tools to Assess the Chemistry and Bioactivity of Endophytic Aspergillus Strain.

PubMed

Tawfike, Ahmed F; Tate, Rothwelle; Abbott, Gráinne; Young, Louise; Viegelmann, Christina; Schumacher, Marc; Diederich, Marc; Edrada-Ebel, RuAngelie

2017-10-01

Endophytic fungi associated with medicinal plants are a potential source of novel chemistry and biology that may find applications as pharmaceutical and agrochemical drugs. In this study, a combination of metabolomics and bioactivity-guided approaches were employed to isolate secondary metabolites with cytotoxicity against cancer cells from an endophytic Aspergillus aculeatus. The endophyte was isolated from the Egyptian medicinal plant Terminalia laxiflora and identified using molecular biological methods. Metabolomics and dereplication studies were accomplished by utilizing the MZmine software coupled with the universal Dictionary of Natural Products database. Metabolic profiling, with aid of multivariate data analysis, was performed at different stages of the growth curve to choose the optimized method suitable for up-scaling. The optimized culture method yielded a crude extract abundant with biologically-active secondary metabolites. Crude extracts were fractionated using different high-throughput chromatographic techniques. Purified compounds were identified by HR-ESI-MS, 1D- and 2D-NMR. This study introduced a new method of dereplication utilizing both high-resolution mass spectrometry and NMR spectroscopy. The metabolites were putatively identified by applying a chemotaxonomic filter. We also present a short review on the diverse chemistry of terrestrial endophytic strains of Aspergillus, which has become a part of our dereplication work and this will be of wide interest to those working in this field. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

Diversity of endophytic fungi associated with the foliar tissue of a hemi-parasitic plant Macrosolen cochinchinensis.

PubMed

Zhou, Sheng-Liang; Yan, Shu-Zhen; Liu, Qi-Sha; Chen, Shuang-Lin

2015-01-01

Foliar fungal endophytes are an important plant-associated fungal group. However, little is known about these fungi in hemi-parasitic plants, a unique plant group which derive nutrients from living plants of its hosts by haustoria while are photosynthetic to some degree. In this paper, the endophytic fungi in the leaves of a species of hemi-parasitic plant, Macrosolen cochinchinensis, were studied by both culture-dependent and culture-independent methods. By culture-dependent method, a total of 511 isolates were recovered from 452 of 600 leaf fragments (colonization rate = 75.3 %) and were identified to be 51 taxa. Valsa sp. was the most abundant (relative abundance = 38.4 %), followed by Cladosporium sp. 1 (13.5 %), Ulocladium sp. (4.3 %), Phomopsis sp. 2 (3.7 %), Hendersonia sp. (3.5 %), and Diaporthe sp. 4 (3.5 %). The Shannon index (H') of the isolated endophytic fungi was 2.628, indicating a moderate diversity. By culture-independent method, Aspergillus spp., Cladosporium sp., Mycosphaerella sp., Acremonium strictum, and Tremella sp. were detected. To our knowledge, the Tremella species have never been detected as endophytes so far. In addition, a cloned sequence was not similar with any current sequence in the Genbank, which may represent a novel species. Altogether, this study documented endophytic fungal assemble in the leaves of M. cochinchinensis which was worthy of our attention, and may expand our knowledge about endophytic fungi within the photosynthetic tissues of plants.

Endophytic Fungi—Alternative Sources of Cytotoxic Compounds: A Review

PubMed Central

Uzma, Fazilath; Mohan, Chakrabhavi D.; Hashem, Abeer; Konappa, Narasimha M.; Rangappa, Shobith; Kamath, Praveen V.; Singh, Bhim P.; Mudili, Venkataramana; Gupta, Vijai K.; Siddaiah, Chandra N.; Chowdappa, Srinivas; Alqarawi, Abdulaziz A.; Abd_Allah, Elsayed F.

2018-01-01

Cancer is a major cause of death worldwide, with an increasing number of cases being reported annually. The elevated rate of mortality necessitates a global challenge to explore newer sources of anticancer drugs. Recent advancements in cancer treatment involve the discovery and development of new and improved chemotherapeutics derived from natural or synthetic sources. Natural sources offer the potential of finding new structural classes with unique bioactivities for cancer therapy. Endophytic fungi represent a rich source of bioactive metabolites that can be manipulated to produce desirable novel analogs for chemotherapy. This review offers a current and integrative account of clinically used anticancer drugs such as taxol, podophyllotoxin, camptothecin, and vinca alkaloids in terms of their mechanism of action, isolation from endophytic fungi and their characterization, yield obtained, and fungal strain improvement strategies. It also covers recent literature on endophytic fungal metabolites from terrestrial, mangrove, and marine sources as potential anticancer agents and emphasizes the findings for cytotoxic bioactive compounds tested against specific cancer cell lines. PMID:29755344

Plant growth-promoting bacterial endophytes.

PubMed

Santoyo, Gustavo; Moreno-Hagelsieb, Gabriel; Orozco-Mosqueda, Ma del Carmen; Glick, Bernard R

2016-02-01

Bacterial endophytes ubiquitously colonize the internal tissues of plants, being found in nearly every plant worldwide. Some endophytes are able to promote the growth of plants. For those strains the mechanisms of plant growth-promotion known to be employed by bacterial endophytes are similar to the mechanisms used by rhizospheric bacteria, e.g., the acquisition of resources needed for plant growth and modulation of plant growth and development. Similar to rhizospheric plant growth-promoting bacteria, endophytic plant growth-promoting bacteria can act to facilitate plant growth in agriculture, horticulture and silviculture as well as in strategies for environmental cleanup (i.e., phytoremediation). Genome comparisons between bacterial endophytes and the genomes of rhizospheric plant growth-promoting bacteria are starting to unveil potential genetic factors involved in an endophytic lifestyle, which should facilitate a better understanding of the functioning of bacterial endophytes. Copyright © 2015 Elsevier GmbH. All rights reserved.

A novel experimental system using the liverwort Marchantia polymorpha and its fungal endophytes reveals diverse and context-dependent effects.

PubMed

Nelson, Jessica M; Hauser, Duncan A; Hinson, Rosemary; Shaw, A Jonathan

2018-05-01

Fungal symbioses are ubiquitous in plants, but their effects have mostly been studied in seed plants. This study aimed to assess the diversity of fungal endophyte effects in a bryophyte and identify factors contributing to the variability of outcomes in these interactions. Fungal endophyte cultures and axenic liverwort clones were isolated from wild populations of the liverwort, Marchantia polymorpha. These collections were combined in a gnotobiotic system to test the effects of fungal isolates on the growth rates of hosts under laboratory conditions. Under the experimental conditions, fungi isolated from M. polymorpha ranged from aggressively pathogenic to strongly growth-promoting, but the majority of isolates caused no detectable change in host growth. Growth promotion by selected fungi depended on nutrient concentrations and was inhibited by coinoculation with multiple fungi. The M. polymorpha endophyte system expands the resources for this model liverwort. The experiments presented here demonstrate a wealth of diversity in fungal interactions even in a host reported to lack standard mycorrhizal symbiosis. In addition, they show that some known pathogens of vascular plants live in M. polymorpha and can confer benefits to this nonvascular host. This highlights the importance of studying endophyte effects across the plant tree of life. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

Antitumor and antimicrobial activities of endophytic fungi from medicinal parts of Aquilaria sinensis.

PubMed

Cui, Jin-long; Guo, Shun-xing; Xiao, Pei-gen

2011-05-01

The purpose of this study was to isolate and characterize endophytic fungi from the stem tissue which can produce fragrant ingredients in Aquilaria sinensis (also called agarwood) to determine their antitumor and antimicrobial activities. Twenty-eight fungal endophytes were isolated from agarwood by strict sterile sample preparation and were classified into 14 genera and 4 taxonomic classes (Sordariomycetes, Dothideomycetes, Saccharomycetes, and Zygomycetes) based on molecular identification. Of the 28 isolates, 13 (46.4%) showed antimicrobial activity against at least one of the test strains by the agar well diffusion method, and 23 isolates (82.1%) displayed antitumor activity against at least one of five cancer cell lines by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The diameters of inhibition zones of YNAS07, YNAS14, HNAS04, HNAS05, HNAS08, and HNAS11 were equal to or higher than 14.0 mm against Staphylococcus aureus, Escherichia coli, Bacillus subtilis, B. subtilis, Aspergillus fumigatus, and B. subtilis, respectively. The inhibition rates of YNAS06, YNAS08, and HNAS06 were not less than 60% to 293-T, 293-T, and SKVO3 cells, respectively. These results suggest that the endophytic fungi associated with agarwood will provide us with not only useful micro-ecological information, but also potential antimicrobial and antitumor agents.

Investigation of the Biosynthetic Potential of Endophytes in Traditional Chinese Anticancer Herbs

PubMed Central

Miller, Kristin I.; Qing, Chen; Sze, Daniel Man Yuen; Neilan, Brett A.

2012-01-01

Traditional Chinese medicine encompasses a rich empirical knowledge of the use of plants for the treatment of disease. In addition, the microorganisms associated with medicinal plants are also of interest as the producers of the compounds responsible for the observed plant bioactivity. The present study has pioneered the use of genetic screening to assess the potential of endophytes to synthesize bioactive compounds, as indicated by the presence of non-ribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) genes. The total DNA extracts of 30 traditional Chinese herbs, were screened for functional genes involved in the biosynthesis of bioactive compounds. The four PCR screens were successful in targeting four bacterial PKS, six bacterial NRPS, ten fungal PKS and three fungal NRPS gene fragments. Analysis of the detected endophyte gene fragments afforded consideration of the possible bioactivity of the natural products produced by endophytes in medicinal herbs. This investigation describes a rapid method for the initial screening of medicinal herbs and has highlighted a subset of those plants that host endophytes with biosynthetic potential. These selected plants can be the focus of more comprehensive endophyte isolation and natural product studies. PMID:22629306

In Vitro Morphogenesis of Arabidopsis to Search for Novel Endophytic Fungi Modulating Plant Growth.

PubMed

Dovana, Francesco; Mucciarelli, Marco; Mascarello, Maurizio; Fusconi, Anna

2015-01-01

Fungal endophytes have shown to affect plant growth and to confer stress tolerance to the host; however, effects of endophytes isolated from water plants have been poorly investigated. In this study, fungi isolated from stems (stem-E) and roots (root-E) of Mentha aquatica L. (water mint) were identified, and their morphogenetic properties analysed on in vitro cultured Arabidopsis (L.) Heynh., 14 and 21 days after inoculation (DAI). Nineteen fungi were analysed and, based on ITS analysis, 17 isolates showed to be genetically distinct. The overall effect of water mint endophytes on Arabidopsis fresh (FW) and dry weight (DW) was neutral and positive, respectively, and the increased DW, mainly occurring 14 DAI, was possibly related to plant defence mechanism. Only three fungi increased both FW and DW of Arabidopsis at 14 and 21 DAI, thus behaving as plant growth promoting (PGP) fungi. E-treatment caused a reduction of root depth and primary root length in most cases and inhibition-to-promotion of root area and lateral root length, from 14 DAI. Only Phoma macrostoma, among the water mint PGP fungi, increased both root area and depth, 21 DAI. Root depth and area 14 DAI were shown to influence DWs, indicating that the extension of the root system, and thus nutrient uptake, was an important determinant of plant dry biomass. Reduction of Arabidopsis root depth occurred to a great extent when plants where treated with stem-E while root area decreased or increased under the effects of stem-E and root-E, respectively, pointing to an influence of the endophyte origin on root extension. M. aquatica and many other perennial hydrophytes have growing worldwide application in water pollution remediation. The present study provided a model for directed screening of endophytes able to modulate plant growth in the perspective of future field applications of these fungi.

Endophytic Diaporthe sp. LG23 Produces a Potent Antibacterial Tetracyclic Triterpenoid.

PubMed

Li, Gang; Kusari, Souvik; Kusari, Parijat; Kayser, Oliver; Spiteller, Michael

2015-08-28

A new lanostanoid, 19-nor-lanosta-5(10),6,8,24-tetraene-1α,3β,12β,22S-tetraol (1), characterized by the presence of an aromatic B ring and hydroxylated at C-1, C-3, C-12, and C-22, was isolated from an endophytic fungus, Diaporthe sp. LG23, inhabiting leaves of the Chinese medicinal plant Mahonia fortunei. Six biosynthetically related known steroids were also isolated in parallel. Their structures were confirmed on the basis of detailed spectroscopic analysis in conjunction with the published data. Compound 1, an unusual fungus-derived 19-nor-lanostane tetracyclic triterpenoid with an aromatic B-ring system, exhibited pronounced antibacterial efficacy against both Gram-positive and -negative bacteria, especially the clinical isolates of Streptococcus pyogenes and Pseudomonas aeruginosa as well as a human pathogenic strain of Staphylococcus aureus. Our results reveal the potential of endophytes not only in conferring host fitness but also in contributing toward traditional host plant medicines.

Synergistic plant-microbe interactions between endophytic bacterial communities and the medicinal plant Glycyrrhiza uralensis F.

PubMed

Li, Li; Mohamad, Osama Abdalla Abdelshafy; Ma, Jinbiao; Friel, Ariel D; Su, Yangui; Wang, Yun; Musa, Zulpiya; Liu, Yonghong; Hedlund, Brian P; Li, Wenjun

2018-03-07

Little is known about the composition, diversity, and geographical distribution of bacterial communities associated with medicinal plants in arid lands. To address this, a collection of 116 endophytic bacteria were isolated from wild populations of the herb Glycyrrhiza uralensis Fisch (licorice) in Xinyuan, Gongliu, and Tekesi of Xinjiang Province, China, and identified based on their 16S rRNA gene sequences. The endophytes were highly diverse, including 20 genera and 35 species. The number of distinct bacterial genera obtained from root tissues was higher (n = 14) compared to stem (n = 9) and leaf (n = 6) tissue. Geographically, the diversity of culturable endophytic genera was higher at the Tekesi (n = 14) and Xinyuan (n = 12) sites than the Gongliu site (n = 4), reflecting the extremely low organic carbon content, high salinity, and low nutrient status of Gongliu soils. The endophytic bacteria exhibited a number of plant growth-promoting activities ex situ, including diazotrophy, phosphate and potassium solubilization, siderophore production, auxin synthesis, and production of hydrolytic enzymes. Twelve endophytes were selected based on their ex situ plant growth-promoting activities for growth chamber assays to test for their ability to promote growth of G. uralensis F. and Triticum aestivum (wheat) plants. Several strains belonging to the genera Bacillus (n = 6) and Achromobacter (n = 1) stimulated total biomass production in both G. uralensis and T. aestivum under low-nutrient conditions. This work is the first report on the isolation and characterization of endophytes associated with G. uralensis F. in arid lands. The results demonstrate the broad diversity of endophytes associated with wild licorice and suggest that some Bacillus strains may be promising candidates for biofertilizers to promote enhanced survival and growth of licorice and other valuable crops in arid environments.

VIT-CMJ2: Endophyte of Agaricus bisporus in Production of Bioactive Compounds

PubMed Central

Gautam, Chandan Kumar; Madhav, Mukund; Sinha, Astha; Jabez Osborne, William

2016-01-01

Background Agaricus bisporus is an edible basidiomycete fungus. Both the body and the mycelium contain compounds comprising a wide range of antimicrobial molecules, contributing in improvement of immunity and tumor-retardation. Objectives The presence of endophytes capable of producing bioactive compounds was investigated in Agaricus bisporus. Materials and Methods Endophytes from Agaricus bisporus was isolated on LB agar. The obtained isolates were characterized morphologically and biochemically. Further 16S rRNA sequencing was implemented for molecular analysis of isolates. The isolate was mass produced and the bioactive compounds were extracted using ethyl acetate, chloroform and hexane. Agar well diffusion method was carried out to seek the potential of any antimicrobial activity of the crude bioactive compounds against known pathogens. GC-MS and FT-IR analysis were performed for the identification of bioactive compounds. Results VIT-CMJ2 was identified as Enterobacter sp. as revealed by 16S rRNA sequencing. Chloroform extract of VIT-CMJ2 showed a maximum zone of inhibition of 19 mm against Salmonella typhi followed by hexane and ethyl acetate extracts. The GC-MS analysis revealed the presence of several bioactive compounds having effective antimicrobial activity like butyl ester, Behenicalcohol, S , S-dioxide derivatives and some others which were later confirmed by FT-IR spectral stretches. Conclusions The present study shows the insight on the way endophytes interact with Agaricus bisporus; thereby improving the nutritional profile. PMID:28959322

The medically important aerobic actinomycetes: epidemiology and microbiology.

PubMed Central

McNeil, M M; Brown, J M

1994-01-01

The aerobic actinomycetes are soil-inhabiting microorganisms that occur worldwide. In 1888, Nocard first recognized the pathogenic potential of this group of microorganisms. Since then, several aerobic actinomycetes have been a major source of interest for the commercial drug industry and have proved to be extremely useful microorganisms for producing novel antimicrobial agents. They have also been well known as potential veterinary pathogens affecting many different animal species. The medically important aerobic actinomycetes may cause significant morbidity and mortality, in particular in highly susceptible severely immunocompromised patients, including transplant recipients and patients infected with human immunodeficiency virus. However, the diagnosis of these infections may be difficult, and effective antimicrobial therapy may be complicated by antimicrobial resistance. The taxonomy of these microorganisms has been problematic. In recent revisions of their classification, new pathogenic species have been recognized. The development of additional and more reliable diagnostic tests and of a standardized method for antimicrobial susceptibility testing and the application of molecular techniques for the diagnosis and subtyping of these microorganisms are needed to better diagnose and treat infected patients and to identify effective control measures for these unusual pathogens. We review the epidemiology and microbiology of the major medically important aerobic actinomycetes. Images PMID:7923055

Wheat seeds harbour bacterial endophytes with potential as plant growth promoters and biocontrol agents of Fusarium graminearum.

PubMed

Díaz Herrera, Silvana; Grossi, Cecilia; Zawoznik, Myriam; Groppa, María Daniela

2016-01-01

The role of endophytic communities of seeds is still poorly characterised. The purpose of this work was to survey the presence of bacterial endophytes in the seeds of a commercial wheat cultivar widely sown in Argentina and to look for plant growth promotion features and biocontrol abilities against Fusarium graminearum among them. Six isolates were obtained from wheat seeds following a culture-dependent protocol. Four isolates were assignated to Paenibacillus genus according to their 16S rRNA sequencing. The only gammaproteobacteria isolated, presumably an Enterobactereaceae of Pantoea genus, was particularly active as IAA and siderophore producer, and also solubilised phosphate and was the only one that grew on N-free medium. Several of these isolates demonstrated ability to restrain F. graminearum growth on dual culture and in a bioassay using barley and wheat kernels. An outstanding ability to form biofilm on an inert surface was corroborated for those Paenibacillus which displayed greater biocontrol of F. graminearum, and the inoculation with one of these isolates in combination with the Pantoea isolate resulted in greater chlorophyll content in barley seedlings. Our results show a significant ecological potential of some components of the wheat seed endophytic community. Copyright © 2016 Elsevier GmbH. All rights reserved.

An endophytic Coniochaeta velutina producing broad spectrum antimycotics.

PubMed

Xie, Jie; Strobel, Gary A; Feng, Tao; Ren, Huishuang; Mends, Morgan T; Zhou, Zeyang; Geary, Brad

2015-06-01

An endophyte (PC27-5) was isolated from stem tissue of Western hemlock (Tsuga heterophylla) in a Pacific Northwest temperate rainforest. Phylogenetic analyses, based on ITS-5.8S rDNA and 18S rDNA sequence data, combined with cultural and morphological analysis showed that endophyte PC27-5 exhibited all characteristics of a fungus identical to Coniochaeta velutina. Furthermore, wide spectrum antimycotics were produced by this endophyte that were active against such plant pathogens as Sclerotinia sclerotiorum, Pythium ultimum, and Verticillium dahliae and lethal to Phythophthora cinnamomi, Pythium ultimum, and Phytophthora palmivora in plate tests. The bioactive components were purified through organic solvent extraction, followed by silica column chromatography, and finally preparative HPLC. The minimum inhibitory concentration of the active fraction to Pythium ultimum, which was gained from preparative HPLC, was 11 μg/ml. UPLC-HRMS analysis showed there were two similar components in the antimycotic fraction. Their molecular formulae were established as C30H22O11 (compound I) and C30H22O10 (compound II) respectively, and preliminary spectral results indicate that they are anthroquinone glycosides. Other non-biologically active compounds were identified in culture fluids of this fungus by spectral means as emodin and chrysophanol--anthroquinone derivatives. This is the first report that Coniochaeta velutina as an endophyte produces bioactive antifungal components.

The culturable endophytic fungal communities of switchgrass grown on a coal-mining site and their effects on plant growth

PubMed Central

Amna, Amna; Opiyo, Stephen Obol

2018-01-01

Plants have a diverse endophytic microbiome that is functionally important for their growth, development, and health. In this study, the diversity and specificity of culturable endophytic fungal communities were explored in one of the most important biofuel crops, switchgrass plants (Panicum virgatum L.), which have been cultivated on a reclaimed coal-mining site for more than 20 years. The endophytic fungi were isolated from the surface-sterilized shoot (leaf and stem), root, and seed tissues of switchgrass plants and then cultured for identification. A total of 1339 fungal isolates were found and 22 operational taxonomic units (OTUs) were sequence identified by internal transcribed spacer (ITS) primers and grouped into 7 orders and 4 classes. Although a diverse range of endophytic fungi associated with switchgrass were documented, the most abundant class, order, and species were Sordariomycetes, Hypocreales, and Fusarium spp. respectively. About 86% of the isolated endophytic fungi were able to enhance the heights of the shoots; 69% could increase the shoot fresh weights; and 62% could improve the shoot dry weights after being reintroduced back into the switchgrass plants, which illustrated their functional importance. Through the Shannon Diversity Index analysis, we observed a gradation of species diversity, with shoots and roots having the similar values and seeds having a lesser value. It was observed that the switchgrass plants showing better growth performance displayed higher endophytic fungal species diversity and abundance. It was also discovered that the rhizosphere soil organic matter content was positively correlated with the fungal species diversity. All these data demonstrate the functional association of these beneficial endophytic fungi with switchgrass and their great potential in improving the switchgrass growth and biomass to benefit the biofuel industry by reducing chemical inputs and burden to the environment. PMID:29902231

The culturable endophytic fungal communities of switchgrass grown on a coal-mining site and their effects on plant growth.

PubMed

Xia, Ye; Amna, Amna; Opiyo, Stephen Obol

2018-01-01

Plants have a diverse endophytic microbiome that is functionally important for their growth, development, and health. In this study, the diversity and specificity of culturable endophytic fungal communities were explored in one of the most important biofuel crops, switchgrass plants (Panicum virgatum L.), which have been cultivated on a reclaimed coal-mining site for more than 20 years. The endophytic fungi were isolated from the surface-sterilized shoot (leaf and stem), root, and seed tissues of switchgrass plants and then cultured for identification. A total of 1339 fungal isolates were found and 22 operational taxonomic units (OTUs) were sequence identified by internal transcribed spacer (ITS) primers and grouped into 7 orders and 4 classes. Although a diverse range of endophytic fungi associated with switchgrass were documented, the most abundant class, order, and species were Sordariomycetes, Hypocreales, and Fusarium spp. respectively. About 86% of the isolated endophytic fungi were able to enhance the heights of the shoots; 69% could increase the shoot fresh weights; and 62% could improve the shoot dry weights after being reintroduced back into the switchgrass plants, which illustrated their functional importance. Through the Shannon Diversity Index analysis, we observed a gradation of species diversity, with shoots and roots having the similar values and seeds having a lesser value. It was observed that the switchgrass plants showing better growth performance displayed higher endophytic fungal species diversity and abundance. It was also discovered that the rhizosphere soil organic matter content was positively correlated with the fungal species diversity. All these data demonstrate the functional association of these beneficial endophytic fungi with switchgrass and their great potential in improving the switchgrass growth and biomass to benefit the biofuel industry by reducing chemical inputs and burden to the environment.

Use of Endophytic and Rhizosphere Actinobacteria from Grapevine Plants To Reduce Nursery Fungal Graft Infections That Lead to Young Grapevine Decline

PubMed Central

Álvarez-Pérez, José Manuel; González-García, Sandra; Cobos, Rebeca; Olego, Miguel Ángel; Ibañez, Ana; Díez-Galán, Alba; Garzón-Jimeno, Enrique

2017-01-01

ABSTRACT Endophytic and rhizosphere actinobacteria isolated from the root system of 1-year-old grafted Vitis vinifera plants were evaluated for their activities against fungi that cause grapevine trunk diseases. A total of 58 endophytic and 94 rhizosphere isolates were tested. Based on an in vitro bioassay, 15.5% of the endophytic isolates and 30.8% of the rhizosphere isolates exhibited antifungal activity against the fungal pathogen Diplodia seriata, whereas 13.8% of the endophytic isolates and 16.0% of the rhizosphere isolates showed antifungal activity against Dactylonectria macrodidyma (formerly Ilyonectria macrodidyma). The strains which showed the greatest in vitro efficacy against both pathogens were further analyzed for their ability to inhibit the growth of Phaeomoniella chlamydospora and Phaeoacremonium minimum (formerly Phaeoacremonium aleophilum). Based on their antifungal activity, three rhizosphere isolates and three endophytic isolates were applied on grafts in an open-root field nursery in a 3-year trial. The field trial led to the identification of one endophytic strain, Streptomyces sp. VV/E1, and two rhizosphere isolates, Streptomyces sp. VV/R1 and Streptomyces sp. VV/R4, which significantly reduced the infection rates produced by the fungal pathogens Dactylonectria sp., Ilyonectria sp., P. chlamydospora, and P. minimum, all of which cause young grapevine decline. The VV/R1 and VV/R4 isolates also significantly reduced the mortality level of grafted plants in the nursery. This study shows that certain actinobacteria could represent a promising new tool for controlling fungal trunk pathogens that infect grapevine plants through the root system in nurseries. IMPORTANCE Grapevine trunk diseases are a major threat to the wine and grape industry worldwide. They cause a significant reduction in yields as well as in grape quality, and they can even cause plant death. Trunk diseases are caused by fungal pathogens that enter through pruning wounds and

Use of Endophytic and Rhizosphere Actinobacteria from Grapevine Plants To Reduce Nursery Fungal Graft Infections That Lead to Young Grapevine Decline.

PubMed

Álvarez-Pérez, José Manuel; González-García, Sandra; Cobos, Rebeca; Olego, Miguel Ángel; Ibañez, Ana; Díez-Galán, Alba; Garzón-Jimeno, Enrique; Coque, Juan José R

2017-12-15

Endophytic and rhizosphere actinobacteria isolated from the root system of 1-year-old grafted Vitis vinifera plants were evaluated for their activities against fungi that cause grapevine trunk diseases. A total of 58 endophytic and 94 rhizosphere isolates were tested. Based on an in vitro bioassay, 15.5% of the endophytic isolates and 30.8% of the rhizosphere isolates exhibited antifungal activity against the fungal pathogen Diplodia seriata , whereas 13.8% of the endophytic isolates and 16.0% of the rhizosphere isolates showed antifungal activity against Dactylonectria macrodidyma (formerly Ilyonectria macrodidyma ). The strains which showed the greatest in vitro efficacy against both pathogens were further analyzed for their ability to inhibit the growth of Phaeomoniella chlamydospora and Phaeoacremonium minimum (formerly Phaeoacremonium aleophilum ). Based on their antifungal activity, three rhizosphere isolates and three endophytic isolates were applied on grafts in an open-root field nursery in a 3-year trial. The field trial led to the identification of one endophytic strain, Streptomyces sp. VV/E1, and two rhizosphere isolates, Streptomyces sp. VV/R1 and Streptomyces sp. VV/R4, which significantly reduced the infection rates produced by the fungal pathogens Dactylonectria sp., Ilyonectria sp., P. chlamydospora , and P. minimum , all of which cause young grapevine decline. The VV/R1 and VV/R4 isolates also significantly reduced the mortality level of grafted plants in the nursery. This study shows that certain actinobacteria could represent a promising new tool for controlling fungal trunk pathogens that infect grapevine plants through the root system in nurseries. IMPORTANCE Grapevine trunk diseases are a major threat to the wine and grape industry worldwide. They cause a significant reduction in yields as well as in grape quality, and they can even cause plant death. Trunk diseases are caused by fungal pathogens that enter through pruning wounds and/or the