Lactic acid bacteria of meat and meat products.

PubMed

Egan, A F

1983-09-01

When the growth of aerobic spoilage bacteria is inhibited, lactic acid bacteria may become the dominant component of the microbial flora of meats. This occurs with cured meats and with meats packaged in films of low gas permeability. The presence of a flora of psychrotrophic lactic acid bacteria on vacuum-packaged fresh chilled meats usually ensures that shelf-life is maximal. When these organisms spoil meats it is generally by causing souring, however other specific types of spoilage do occur. Some strains cause slime formation and greening of cured meats, and others may produce hydrogen sulphide during growth on vacuum-packaged beef. The safety and stability of fermented sausages depends upon fermentation caused by lactic acid bacteria. Overall the presence on meats of lactic acid bacteria is more desirable than that of the types of bacteria they have replaced.

Comparative genomics of the lactic acid bacteria

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

Makarova, K.; Slesarev, A.; Wolf, Y.

Lactic acid-producing bacteria are associated with various plant and animal niches and play a key role in the production of fermented foods and beverages. We report nine genome sequences representing the phylogenetic and functional diversity of these bacteria. The small genomes of lactic acid bacteria encode a broad repertoire of transporters for efficient carbon and nitrogen acquisition from the nutritionally rich environments they inhabit and reflect a limited range of biosynthetic capabilities that indicate both prototrophic and auxotrophic strains. Phylogenetic analyses, comparison of gene content across the group, and reconstruction of ancestral gene sets indicate a combination of extensive genemore » loss and key gene acquisitions via horizontal gene transfer during the coevolution of lactic acid bacteria with their habitats.« less

Strain typing of acetic acid bacteria responsible for vinegar production by the submerged elaboration method.

PubMed

Fernández-Pérez, Rocío; Torres, Carmen; Sanz, Susana; Ruiz-Larrea, Fernanda

2010-12-01

Strain typing of 103 acetic acid bacteria isolates from vinegars elaborated by the submerged method from ciders, wines and spirit ethanol, was carried on in this study. Two different molecular methods were utilised: pulsed field gel electrophoresis (PFGE) of total DNA digests with a number of restriction enzymes, and enterobacterial repetitive intergenic consensus (ERIC) - PCR analysis. The comparative study of both methods showed that restriction fragment PFGE of SpeI digests of total DNA was a suitable method for strain typing and for determining which strains were present in vinegar fermentations. Results showed that strains of the species Gluconacetobacter europaeus were the most frequent leader strains of fermentations by the submerged method in the studied vinegars, and among them strain R1 was the predominant one. Results showed as well that mixed populations (at least two different strains) occurred in vinegars from cider and wine, whereas unique strains were found in spirit vinegars, which offered the most stressing conditions for bacterial growth. Copyright © 2010 Elsevier Ltd. All rights reserved.

Lactic acid bacteria: promising supplements for enhancing the biological activities of kombucha.

PubMed

Nguyen, Nguyen Khoi; Dong, Ngan Thi Ngoc; Nguyen, Huong Thuy; Le, Phu Hong

2015-01-01

Kombucha is sweetened black tea that is fermented by a symbiosis of bacteria and yeast embedded within a cellulose membrane. It is considered a health drink in many countries because it is a rich source of vitamins and may have other health benefits. It has previously been reported that adding lactic acid bacteria (Lactobacillus) strains to kombucha can enhance its biological functions, but in that study only lactic acid bacteria isolated from kefir grains were tested. There are many other natural sources of lactic acid bacteria. In this study, we examined the effects of lactic acid bacteria from various fermented Vietnamese food sources (pickled cabbage, kefir and kombucha) on kombucha's three main biological functions: glucuronic acid production, antibacterial activity and antioxidant ability. Glucuronic acid production was determined by high-performance liquid chromatography-mass spectrometry, antibacterial activity was assessed by the agar-well diffusion method and antioxidant ability was evaluated by determining the 2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity. Four strains of food-borne pathogenic bacteria were used in our antibacterial experiments: Listeria monocytogenes ATCC 19111, Escherichia coli ATCC 8739, Salmonella typhimurium ATCC 14028 and Bacillus cereus ATCC 11778. Our findings showed that lactic acid bacteria strains isolated from kefir are superior to those from other sources for improving glucuronic acid production and enhancing the antibacterial and antioxidant activities of kombucha. This study illustrates the potential of Lactobacillus casei and Lactobacillus plantarum isolated from kefir as biosupplements for enhancing the bioactivities of kombucha.

Discrimination of wine lactic acid bacteria by Raman spectroscopy.

PubMed

Rodriguez, Susan B; Thornton, Mark A; Thornton, Roy J

2017-08-01

Species of Lactobacillus, Pediococcus, Oenococcus, and Leuconostoc play an important role in winemaking, as either inoculants or contaminants. The metabolic products of these lactic acid bacteria have considerable effects on the flavor, aroma, and texture of a wine. However, analysis of a wine's microflora, especially the bacteria, is rarely done unless spoilage becomes evident, and identification at the species or strain level is uncommon as the methods required are technically difficult and expensive. In this work, we used Raman spectral fingerprints to discriminate 19 strains of Lactobacillus, Pediococcus, and Oenococcus. Species of Lactobacillus and Pediococcus and strains of O. oeni and P. damnosus were classified with high sensitivity: 86-90 and 84-85%, respectively. Our results demonstrate that a simple, inexpensive method utilizing Raman spectroscopy can be used to accurately identify lactic acid bacteria isolated from wine.

Characterization and application of lactic acid bacteria for tropical silage preparation.

PubMed

Pholsen, Suradej; Khota, Waroon; Pang, Huili; Higgs, David; Cai, Yimin

2016-10-01

Strains TH 14, TH 21 and TH 64 were isolated from tropical silages, namely corn stover, sugar cane top and rice straw, respectively, prepared in Thailand. These strains were selected by low pH growth range and high lactic acid-producing ability, similar to some commercial inoculants. Based on the analysis of 16S ribosomal RNA gene sequence and DNA-DNA relatedness, strain TH 14 was identified as Lactobacillus casei, and strains TH 21 and TH 64 were identified as L. plantarum. Strains TH 14, TH 21, TH 64 and two commercial inoculants, CH (L. plantarum) and SN (L. rhamnosus), were used as additives to fresh and wilted purple Guinea and sorghum silages prepared using a small-scale fermentation method. The number of epiphytic lactic acid bacteria (LAB) in the forages before ensilage was relatively low but the numbers of coliform and aerobic bacteria were higher. Sorghum silages at 30 days of fermentation were all well preserved with low pH (3.56) and high lactic acid production (72.86 g/kg dry matter). Purple Guinea silage inoculated with LAB exhibited reduced count levels of aerobic and coliform bacteria, lower pH, butyric acid and ammonia nitrogen and increased lactic acid concentration, compared with the control. Strain TH 14 more effectively improved lactic acid production compared with inoculants and other strains. © 2016 Japanese Society of Animal Science. © 2016 Japanese Society of Animal Science.

Lactic acid bacteria from raw milk as potentially beneficial strains to prevent bovine mastitis.

PubMed

Espeche, M Carolina; Pellegrino, Matías; Frola, Ignacio; Larriestra, Alejandro; Bogni, Cristina; Nader-Macías, M E Fátima

2012-02-01

Bovine mastitis produces a wide variety of problems in the dairy farm. The treatment of this disease is based on the use of antibiotics which are not always effective. These drugs are also responsible for the presence of residues in the milk and the increase of antibiotic-resistant strains. Probiotic products were proposed as a valid alternative to antibiotic therapies and are also useful for the prevention of infectious syndromes. With the aim of designing a probiotic product to prevent bovine mastitis, lactic acid bacteria (LAB) were isolated from foremilk samples from different dairy farms in Córdoba-Argentina. One hundred and seventeen LAB were isolated and their beneficial characteristics such as the production of inhibitory substances, surface properties and production of exopolysaccharides (EPS) were assessed. Most of them displayed low degree of hydrophobicity, autoaggregation, EPS negative phenotype and were identified as Enterococcus hirae and Pediococcus pentosaceus. Nine LAB strains inhibited three indicator bacteria. Some isolates were pre-selected and genetically identified according to the results obtained. Antibiotic resistance and virulence factors were studied for the assessment of the safety of the strains. The results obtained were compared to those reported previously from samples obtained in the North-western area of the country and some differences were found. Copyright © 2012 Elsevier Ltd. All rights reserved.

Acetic acid production from food wastes using yeast and acetic acid bacteria micro-aerobic fermentation.

PubMed

Li, Yang; He, Dongwei; Niu, Dongjie; Zhao, Youcai

2015-05-01

In this study, yeast and acetic acid bacteria strains were adopted to enhance the ethanol-type fermentation resulting to a volatile fatty acids yield of 30.22 g/L, and improve acetic acid production to 25.88 g/L, with food wastes as substrate. In contrast, only 12.81 g/L acetic acid can be obtained in the absence of strains. The parameters such as pH, oxidation reduction potential and volatile fatty acids were tested and the microbial diversity of different strains and activity of hydrolytic ferment were investigated to reveal the mechanism. The optimum pH and oxidation reduction potential for the acetic acid production were determined to be at 3.0-3.5 and -500 mV, respectively. Yeast can convert organic matters into ethanol, which is used by acetic acid bacteria to convert the organic wastes into acetic acid. The acetic acid thus obtained from food wastes micro-aerobic fermentation liquid could be extracted by distillation to get high-pure acetic acid.

Diversity of predominant lactic acid bacteria associated with cocoa fermentation in Nigeria.

PubMed

Kostinek, Melanie; Ban-Koffi, Louis; Ottah-Atikpo, Margaret; Teniola, David; Schillinger, Ulrich; Holzapfel, Wilhelm H; Franz, Charles M A P

2008-04-01

The fermentation of cocoa relies on a complex succession of bacteria and filamentous fungi, all of which can have an impact on cocoa flavor. So far, few investigations have focused on the diversity of lactic acid bacteria involved in cocoa fermentation, and many earlier investigations did not rely on polyphasic taxonomical approaches, which take both phenotypic and genotypic characterization techniques into account. In our study, we characterized predominant lactic acid bacteria from cocoa fermentations in Nigeria, using a combination of phenotypic tests, repetitive extragenic palindromic PCR, and sequencing of the 16S rRNA gene of representative strains for accurate species identification. Thus, of a total of 193 lactic acid bacteria (LAB) strains isolated from common media used to cultivate LAB, 40 (20.7%) were heterofermentative and consisted of either L. brevis or L. fermentum strains. The majority of the isolates were homofermentative rods (110 strains; 57% of isolates) which were characterized as L. plantarum strains. The homofermentative cocci consisted predominantly of 35 (18.1% of isolates) Pediococcus acidilactici strains. Thus, the LAB populations derived from these media in this study were accurately described. This can contribute to the further assessment of the effect of common LAB strains on the flavor characteristics of fermenting cocoa in further studies.

Effect of chosen lactic acid bacteria strains on Staphylococcus aureus in vitro as well as in meat and raw sausages.

PubMed

Gomółka-Pawlicka, M; Uradziński, J; Wiszniewska, A

2004-01-01

The present study was aimed at determining the influence of 15 strains of lactic acid bacteria on the growth of 2 Staphylococcus aureus strains in vitro as well as in meat and raw sausages. The investigations were performed within the framework of three alternate stages which differed in respect to the products studied, the number of Lactobacillus sp. strains and, partly, methodological approach. The study also considered water activity (a(w)) and pH of the products investigated. The results obtained are demonstrated in 5 diagrams. It was found that among 15 strains of Lactobacillus aureus investigated only one strain, Lactobacillus helveticus T 78, showed antagonistic effect on studied strains of Staphylococcus aureus both in vitro as well as in meat and raw sausages. Five other strains of Lactobacillus spp. displayed the antagonistic effect in vitro only. The temperature and incubation time of sausages, but also the type of sausage stuffing were found to have a distinct or slight influence, respectively, on the antagonistic interaction between the bacteria. However, this phenomenon was affected by neither a(w) nor pH.

Lactic acid bacteria in the quality improvement and depreciation of wine.

PubMed

Lonvaud-Funel, A

1999-01-01

The winemaking process includes two main steps: lactic acid bacteria are responsible for the malolactic fermentation which follows the alcoholic fermentation by yeasts. Both types of microorganisms are present on grapes and on cellar equipment. Yeasts are better adapted to growth in grape must than lactic acid bacteria, so the alcoholic fermentation starts quickly. In must, up to ten lactic acid bacteria species can be identified. They belong to the Lactobacillus, Pediococcus, Leuconostoc and Oenococcus genera. Throughout alcoholic fermentation, a natural selection occurs and finally the dominant species is O. oeni, due to interactions between yeasts and bacteria and between bacteria themselves. After bacterial growth, when the population is over 10(6) CFU/ml, malolactic transformation is the obvious change in wine composition. However, many other substrates can be metabolized. Some like remaining sugars and citric acid are always assimilated by lactic acid bacteria, thus providing them with energy and carbon. Other substrates such as some amino acids may be used following pathways restricted to strains carrying the adequate enzymes. Some strains can also produce exopolysaccharides. All these transformations greatly influence the sensory and hygienic quality of wine. Malic acid transformation is encouraged because it induces deacidification. Diacetyl produced from citric acid is also helpful to some extent. Sensory analyses show that many other reactions change the aromas and make malolactic fermentation beneficial, but they are as yet unknown. On the contrary, an excess of acetic acid, the synthesis of glucane, biogenic amines and precursors of ethylcarbamate are undesirable. Fortunately, lactic acid bacteria normally multiply in dry wines; moreover some of these activities are not widespread. Moreover, the most striking trait of wine lactic acid bacteria is their capacity to adapt to a hostile environment. The mechanisms for this are not yet completely elucidated

Precision genome engineering in lactic acid bacteria

PubMed Central

2014-01-01

Innovative new genome engineering technologies for manipulating chromosomes have appeared in the last decade. One of these technologies, recombination mediated genetic engineering (recombineering) allows for precision DNA engineering of chromosomes and plasmids in Escherichia coli. Single-stranded DNA recombineering (SSDR) allows for the generation of subtle mutations without the need for selection and without leaving behind any foreign DNA. In this review we discuss the application of SSDR technology in lactic acid bacteria, with an emphasis on key factors that were critical to move this technology from E. coli into Lactobacillus reuteri and Lactococcus lactis. We also provide a blueprint for how to proceed if one is attempting to establish SSDR technology in a lactic acid bacterium. The emergence of CRISPR-Cas technology in genome engineering and its potential application to enhancing SSDR in lactic acid bacteria is discussed. The ability to perform precision genome engineering in medically and industrially important lactic acid bacteria will allow for the genetic improvement of strains without compromising safety. PMID:25185700

Acrylic acid removal by acrylic acid utilizing bacteria from acrylonitrile-butadiene-styrene resin manufactured wastewater treatment system.

PubMed

Wang, C C; Lee, C M

2006-01-01

The aim of this study is to isolate the acrylic acid utilizing bacteria from the ABS resin manufactured wastewater treatment system. The bacteria should have the ability to remove acrylic acid and tolerate the acrylonitrile and acrylamide toxicity. The aim is also to understand the performance of isolated pure strain for treating different initial acrylic acid concentrations from synthetic wastewater. The results are: twenty strains were isolated from the ABS resin manufactured wastewater treatment system and twelve of them could utilize 600 mg/l acrylic acid for growth. Seven of twelve strains could tolerate the acrylonitrile and acrylamide toxicity, when the concentration was below 300 mg/l. Bacillus thuringiensis was one of the seven strains and the optimum growth temperature was 32 degrees C. Bacillus thuringiensis could utilize acrylic acid for growth, when the initial acrylic acid concentration was below 1,690.4 mg/l. Besides this, when the initial acrylic acid concentration was below 606.8 mg/l, the acrylic acid removal efficiency exceeded 96.3%. Bacillus thuringiensis could tolerate 295.7 mg/l acrylamide and 198.4 mg/l acrylonitrile toxicity but could not tolerate 297.3 mg/l epsilon-caprolactam.

Overview on mechanisms of acetic acid resistance in acetic acid bacteria.

PubMed

Wang, Bin; Shao, Yanchun; Chen, Fusheng

2015-02-01

Acetic acid bacteria (AAB) are a group of gram-negative or gram-variable bacteria which possess an obligate aerobic property with oxygen as the terminal electron acceptor, meanwhile transform ethanol and sugar to corresponding aldehydes, ketones and organic acids. Since the first genus Acetobacter of AAB was established in 1898, 16 AAB genera have been recorded so far. As the main producer of a world-wide condiment, vinegar, AAB have evolved an elegant adaptive system that enables them to survive and produce a high concentration of acetic acid. Some researches and reviews focused on mechanisms of acid resistance in enteric bacteria and made the mechanisms thoroughly understood, while a few investigations did in AAB. As the related technologies with proteome, transcriptome and genome were rapidly developed and applied to AAB research, some plausible mechanisms conferring acetic acid resistance in some AAB strains have been published. In this review, the related mechanisms of AAB against acetic acid with acetic acid assimilation, transportation systems, cell morphology and membrane compositions, adaptation response, and fermentation conditions will be described. Finally, a framework for future research for anti-acid AAB will be provided.

Use of an acidophilic yeast strain to enable the growth of leaching bacteria on solid media.

PubMed

Ngom, Baba; Liang, Yili; Liu, Yi; Yin, Huaqun; Liu, Xueduan

2015-03-01

In this study, a Candida digboiensis strain was isolated from a heap leaching plant in Zambia and used in double-layer agar plate to efficiently isolate and purify leaching bacteria. Unlike Acidiphilium sp., the yeast strain was tetrathionate tolerant and could metabolize a great range of organic compounds including organic acids. These properties allowed the yeast strain to enable and fasten the growth of iron and sulfur oxidizers on double-layer agar plate. The isolates were identified as Acidithiobacillus ferrooxidans FOX1, Leptospirillun ferriphilum BN, and Acidithiobacillus thiooxidans ZMB. These three leaching bacteria were inhibited by organic acids such as acetic and propionic acids; however, their activities were enhanced by Candida digboiensis NB under dissolved organic matter stress.

Screening and Characterization of Lactic Acid Bacteria Strains with Anti-inflammatory Activities through in vitro and Caenorhabditis elegans Model Testing

PubMed Central

Park, Mi Ri; Kim, Younghoon; Lee, Myung-Ki

2015-01-01

The present study was conducted to screen candidate probiotic strains for anti-inflammatory activity. Initially, a nitric oxide (NO) assay was used to test selected candidate probiotic strains for anti-inflammatory activity in cultures of the murine macrophage cell line, RAW 264.7. Then, the in vitro probiotic properties of the strains, including bile tolerance, acid resistance, and growth in skim milk media, were investigated. We also performed an in vitro hydrophobicity test and an intestinal adhesion assay using Caenorhabditis elegans as a surrogate in vivo model. From our screening, we obtained 4 probiotic candidate lactic acid bacteria (LAB) strains based on their anti-inflammatory activity in lipopolysaccharide (LPS)-stimulated RAW 264.7 cell cultures and the results of the in vitro and in vivo probiotic property assessments. Molecular characterization using 16S rDNA sequencing analysis identified the 4 LAB strains as Lactobacillus plantarum. The selected L. plantarum strains (CAU1054, CAU1055, CAU1064, and CAU1106) were found to possess desirable in vitro and in vivo probiotic properties, and these strains are good candidates for further investigations in animal models and human clinical studies to elucidate the mechanisms underlying their anti-inflammatory activities. PMID:26761805

Dynamics and Biodiversity of Populations of Lactic Acid Bacteria and Acetic Acid Bacteria Involved in Spontaneous Heap Fermentation of Cocoa Beans in Ghana▿

PubMed Central

Camu, Nicholas; De Winter, Tom; Verbrugghe, Kristof; Cleenwerck, Ilse; Vandamme, Peter; Takrama, Jemmy S.; Vancanneyt, Marc; De Vuyst, Luc

2007-01-01

The Ghanaian cocoa bean heap fermentation process was studied through a multiphasic approach, encompassing both microbiological and metabolite target analyses. A culture-dependent (plating and incubation, followed by repetitive-sequence-based PCR analyses of picked-up colonies) and culture-independent (denaturing gradient gel electrophoresis [DGGE] of 16S rRNA gene amplicons, PCR-DGGE) approach revealed a limited biodiversity and targeted population dynamics of both lactic acid bacteria (LAB) and acetic acid bacteria (AAB) during fermentation. Four main clusters were identified among the LAB isolated: Lactobacillus plantarum, Lactobacillus fermentum, Leuconostoc pseudomesenteroides, and Enterococcus casseliflavus. Other taxa encompassed, for instance, Weissella. Only four clusters were found among the AAB identified: Acetobacter pasteurianus, Acetobacter syzygii-like bacteria, and two small clusters of Acetobacter tropicalis-like bacteria. Particular strains of L. plantarum, L. fermentum, and A. pasteurianus, originating from the environment, were well adapted to the environmental conditions prevailing during Ghanaian cocoa bean heap fermentation and apparently played a significant role in the cocoa bean fermentation process. Yeasts produced ethanol from sugars, and LAB produced lactic acid, acetic acid, ethanol, and mannitol from sugars and/or citrate. Whereas L. plantarum strains were abundant in the beginning of the fermentation, L. fermentum strains converted fructose into mannitol upon prolonged fermentation. A. pasteurianus grew on ethanol, mannitol, and lactate and converted ethanol into acetic acid. A newly proposed Weissella sp., referred to as “Weissella ghanaensis,” was detected through PCR-DGGE analysis in some of the fermentations and was only occasionally picked up through culture-based isolation. Two new species of Acetobacter were found as well, namely, the species tentatively named “Acetobacter senegalensis” (A. tropicalis-like) and �

Lipoquinones of some spore-forming rods, lactic-acid bacteria and actinomycetes.

PubMed

Hess, A; Holländer, R; Mannheim, W

1979-11-01

The respiratory quinones of 73 strains of Gram-positive bacteria including spore-forming rods, lactic-acid bacteria and actinomyctes were examined. Menaquinones with seven isoprenoid units (MK-7) were the main quinone type found in representatives of the genus Bacillus and in Sporolactobacillus inulinus. However, a strain of B. thuringiensis produced MK-8 in addition to MK-7, and strains of B. lentus and B. pantothenticus appeared to produce MK-9 and MK-8, respectively, with no MK-7. In the clostridia and lactic-acid bacteria, no quinones were found, except in Pediococcus cerevisiae NCTC 8066 and Lactobacillus casei subsp. rhamnosus ATCC 7469, which contained menaquinones, and Streptococcus faecalis NCTC 775 and HIM 478-1, which contained demethylmenaquinones, in relatively low concentrations. Menaquinones were also found in the actinomycetes (except Actinomyces odontolyticus and Bifidobacterium bifidum which did not produce any quinones) and in Protaminobacter alboflavus ATCC 8458, the so-called Actinobacillus actinoides ATCC 15900 and Noguchia granulosis NCTC 10559.

Functional genomics of lactic acid bacteria: from food to health

PubMed Central

2014-01-01

Genome analysis using next generation sequencing technologies has revolutionized the characterization of lactic acid bacteria and complete genomes of all major groups are now available. Comparative genomics has provided new insights into the natural and laboratory evolution of lactic acid bacteria and their environmental interactions. Moreover, functional genomics approaches have been used to understand the response of lactic acid bacteria to their environment. The results have been instrumental in understanding the adaptation of lactic acid bacteria in artisanal and industrial food fermentations as well as their interactions with the human host. Collectively, this has led to a detailed analysis of genes involved in colonization, persistence, interaction and signaling towards to the human host and its health. Finally, massive parallel genome re-sequencing has provided new opportunities in applied genomics, specifically in the characterization of novel non-GMO strains that have potential to be used in the food industry. Here, we provide an overview of the state of the art of these functional genomics approaches and their impact in understanding, applying and designing lactic acid bacteria for food and health. PMID:25186768

Functional genomics of lactic acid bacteria: from food to health.

PubMed

Douillard, François P; de Vos, Willem M

2014-08-29

Genome analysis using next generation sequencing technologies has revolutionized the characterization of lactic acid bacteria and complete genomes of all major groups are now available. Comparative genomics has provided new insights into the natural and laboratory evolution of lactic acid bacteria and their environmental interactions. Moreover, functional genomics approaches have been used to understand the response of lactic acid bacteria to their environment. The results have been instrumental in understanding the adaptation of lactic acid bacteria in artisanal and industrial food fermentations as well as their interactions with the human host. Collectively, this has led to a detailed analysis of genes involved in colonization, persistence, interaction and signaling towards to the human host and its health. Finally, massive parallel genome re-sequencing has provided new opportunities in applied genomics, specifically in the characterization of novel non-GMO strains that have potential to be used in the food industry. Here, we provide an overview of the state of the art of these functional genomics approaches and their impact in understanding, applying and designing lactic acid bacteria for food and health.

Amino acid catabolism and generation of volatiles by lactic acid bacteria.

PubMed

Tavaria, F K; Dahl, S; Carballo, F J; Malcata, F X

2002-10-01

Twelve isolates of lactic acid bacteria, belonging to the Lactobacillus, Lactococcus, Leuconostoc, and Enterococcus genera, were previously isolated from 180-d-old Serra da Estrela cheese, a traditional Portuguese cheese manufactured from raw milk and coagulated with a plant rennet. These isolates were subsequently tested for their ability to catabolize free amino acids, when incubated independently with each amino acid in free form or with a mixture thereof. Attempts were made in both situations to correlate the rates of free amino acid uptake with the numbers of viable cells. When incubated individually, leucine, valine, glycine, aspartic acid, serine, threonine, lysine, glutamic acid, and alanine were degraded by all strains considered; arginine tended to build up, probably because of transamination of other amino acids. When incubated together, the degradation of free amino acids by each strain was dependent on pH (with an optimum pH around 6.0). The volatiles detected in ripened Serra da Estrela cheese originated mainly from leucine, phenylalanine, alanine, and valine, whereas in vitro they originated mainly from valine, phenylalanine, serine, leucine, alanine, and threonine. The wild strains tested offer a great potential for flavor generation, which might justify their inclusion in a tentative starter/nonstarter culture for that and similar cheeses.

Heterologous expression of enterocin AS-48 in several strains of lactic acid bacteria.

PubMed

Fernández, M; Martínez-Bueno, M; Martín, M C; Valdivia, E; Maqueda, M

2007-05-01

Enterococcus faecalis produces a cationic and circular enterocin, AS-48, of 7149 Da, the genetic determinants of which are located within the pMB2 plasmid. We have compared enterocin AS-48 production by different enterococci species with that of other 'safe' lactic acid bacteris (LAB) (GRAS status) and looked into the subsequent application of this enterocin in food production. In an effort to exploit this system for the heterologous expression of enterocin AS-48, a number of vectors containing the as-48 cluster were constructed and used to transform several LAB strains (genera Enterococcus, Lactococcus and Lactobacillus) Heterologous production of enterocin AS-48 failed when bacteria other than those belonging to the genus Enterococcus were used as hosts, although expression of a partial level of resistance against AS-48 were always detected, ruling out the possibility of a lack of recognition of the enterococcal promoters. Our results reveal the special capacity of species from the genus Enterococcus to produce AS-48, an enterocin that requires a post-transcriptional modification to generate a circular peptide with a wide range of inhibitory activity against pathogenic and spoilage bacteria. Preliminary experiments in foodstuffs using nonvirulent enterococci with interesting functional properties reveal the possibility of a biotechnological application of these transformants.

Metabolomic study of Chilean biomining bacteria Acidithiobacillus ferrooxidans strain Wenelen and Acidithiobacillus thiooxidans strain Licanantay.

PubMed

Martínez, Patricio; Gálvez, Sebastián; Ohtsuka, Norimasa; Budinich, Marko; Cortés, María Paz; Serpell, Cristián; Nakahigashi, Kenji; Hirayama, Akiyoshi; Tomita, Masaru; Soga, Tomoyoshi; Martínez, Servet; Maass, Alejandro; Parada, Pilar

2013-02-01

In this study, we present the first metabolic profiles for two bioleaching bacteria using capillary electrophoresis coupled with mass spectrometry. The bacteria, Acidithiobacillus ferrooxidans strain Wenelen (DSM 16786) and Acidithiobacillus thiooxidans strain Licanantay (DSM 17318), were sampled at different growth phases and on different substrates: the former was grown with iron and sulfur, and the latter with sulfur and chalcopyrite. Metabolic profiles were scored from planktonic and sessile states. Spermidine was detected in intra- and extracellular samples for both strains, suggesting it has an important role in biofilm formation in the presence of solid substrate. The canonical pathway for spermidine synthesis seems absent as its upstream precursor, putrescine, was not present in samples. Glutathione, a catalytic activator of elemental sulfur, was identified as one of the most abundant metabolites in the intracellular space in A. thiooxidans strain Licanantay, confirming its participation in the sulfur oxidation pathway. Amino acid profiles varied according to the growth conditions and bioleaching species. Glutamic and aspartic acid were highly abundant in intra- and extracellular extracts. Both are constituents of the extracellular matrix, and have a probable role in cell detoxification. This novel metabolomic information validates previous knowledge from in silico metabolic reconstructions based on genomic sequences, and reveals important biomining functions such as biofilm formation, energy management and stress responses. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11306-012-0443-3) contains supplementary material, which is available to authorized users.

Identification and Characterization of Lactic Acid Bacteria in a Commercial Probiotic Culture

PubMed Central

MENCONI, Anita; KALLAPURA, Gopala; LATORRE, Juan D.; MORGAN, Marion J.; PUMFORD, Neil R.; HARGIS, Billy M.; TELLEZ, Guillermo

2014-01-01

The aim of the present study was to describe the identification and characterization (physiological properties) of two strains of lactic acid bacteria (LAB 18 and 48) present in a commercial probiotic culture, FloraMax®-B11. Isolates were characterized morphologically, and identified biochemically. In addition, the MIDI System ID, the Biolog ID System, and 16S rRNA sequence analyses for identification of LAB 18 and LAB 48 strains were used to compare the identification results. Tolerance and resistance to acidic pH, high osmotic concentration of NaCl, and bile salts were tested in broth medium. In vitro assessment of antimicrobial activity against enteropathogenic bacteria and susceptibility to antibiotics were also tested. The results obtained in this study showed tolerance of LAB 18 and LAB 48 to pH 3.0, 6.5% NaCl and a high bile salt concentration (0.6%). Both strains evaluated showed in vitro antibacterial activity against Salmonella enterica serovar Enteritidis, Escherichia coli (O157:H7), and Campylobacter jejuni. These are important characteristics of lactic acid bacteria that should be evaluated when selecting strains to be used as probiotics. Antimicrobial activity of these effective isolates may contribute to efficacy, possibly by direct antimicrobial activity in vivo. PMID:24936379

Antigenotoxic properties of lactic acid bacteria in the S. typhimurium mutagenicity assay.

PubMed

Pool-Zobel, B L; Münzner, R; Holzapfel, W H

1993-01-01

A high percentage of human tumors is reported to be related to dietary habits. One way to improve the nutritional impact is to increase the intake of protective factors, such as inhibitors of DNA damage and other types of anticarcinogens. Specific strains of lactic acid bacteria used to ferment milk are promising candidates that may be antimutagenic and anticarcinogenic. We have studied the antimutagenicity of 10 isolated strains of beneficial lactic acid bacteria. Four types of fermented milk products were also studied for their protective properties. The effect of these bacteria on the yield of revertants induced by nitrosated beef extract was investigated in the Salmonella typhimurium mutagenicity assay. Eight of 10 isolated Lactobacillus strains reduced the yield of his+ revertants almost back to the levels of the untreated controls. Different fermented fresh yogurts containing viable bacteria (probably Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus or Lactobacillus acidophilus and Bifidobacteria) showed protective effects as well. The degree of suppressing revertants was independent of the yogurt's fat content. In contrast, yogurt products that had been heat treated were not inhibitory. The other fresh fermented milk products (e.g., buttermilk, kefir, and "Dickmilch") were not antimutagenic in this study. The results imply that some bacteria used in milk processing have an antimutagenic potential and that this property is specific for the bacterial strain.

BASE COMPOSITION OF THE DEOXYRIBONUCLEIC ACID OF SULFATE-REDUCING BACTERIA

PubMed Central

Sigal, Nicole; Senez, Jacques C.; Le Gall, Jean; Sebald, Madeleine

1963-01-01

Sigal, Nicole (Laboratoire de Chimie Bactérienne du CNRS, Marseille, France), Jacques C. Senez, Jean Le Gall, and Madeleine Sebald. Base composition of the deoxyribonucleic acid of sulfate-reducing bacteria. J. Bacteriol. 85:1315–1318. 1963—The deoxyribonucleic acid constitution of several strains of sulfate-reducing bacteria has been analytically determined. The results of these studies show that this group of microorganisms includes at least four subgroups characterized by significantly different values of the adenine plus thymine to guanine plus cytosine ratio. The nonsporulated forms with polar flagellation, containing both cytochrome c3 and desulfoviridin, are divided into two subgroups. One includes the fresh-water, nonhalophilic strains with base ratio from 0.54 to 0.59, and the other includes the halophilic or halotolerant strains with base ratio from 0.74 to 0.77. The sporulated, peritrichous strains without cytochrome and desulfoviridin (“nigrificans” and “orientis”) are distinct from the above two types and differ from each other, having base ratios of 1.20 and 1.43, respectively. PMID:14047223

BASE COMPOSITION OF THE DEOXYRIBONUCLEIC ACID OF SULFATE-REDUCING BACTERIA.

PubMed

SIGAL, N; SENEZ, J C; LEGALL, J; SEBALD, M

1963-06-01

Sigal, Nicole (Laboratoire de Chimie Bactérienne du CNRS, Marseille, France), Jacques C. Senez, Jean Le Gall, and Madeleine Sebald. Base composition of the deoxyribonucleic acid of sulfate-reducing bacteria. J. Bacteriol. 85:1315-1318. 1963-The deoxyribonucleic acid constitution of several strains of sulfate-reducing bacteria has been analytically determined. The results of these studies show that this group of microorganisms includes at least four subgroups characterized by significantly different values of the adenine plus thymine to guanine plus cytosine ratio. The nonsporulated forms with polar flagellation, containing both cytochrome c(3) and desulfoviridin, are divided into two subgroups. One includes the fresh-water, nonhalophilic strains with base ratio from 0.54 to 0.59, and the other includes the halophilic or halotolerant strains with base ratio from 0.74 to 0.77. The sporulated, peritrichous strains without cytochrome and desulfoviridin ("nigrificans" and "orientis") are distinct from the above two types and differ from each other, having base ratios of 1.20 and 1.43, respectively.

Isolation of Soil Bacteria Adapted To Degrade Humic Acid-Sorbed Phenanthrene

PubMed Central

Vacca, D. J.; Bleam, W. F.; Hickey, W. J.

2005-01-01

The goal of these studies was to determine how sorption by humic acids affected the bioavailability of polynuclear aromatic hydrocarbons (PAHs) to PAH-degrading microbes. Micellar solutions of humic acid were used as sorbents, and phenanthrene was used as a model PAH. Enrichments from PAH-contaminated soils established with nonsorbed phenanthrene yielded a total of 25 different isolates representing a diversity of bacterial phylotypes. In contrast, only three strains of Burkholderia spp. and one strain each of Delftia sp. and Sphingomonas sp. were isolated from enrichments with humic acid-sorbed phenanthrene (HASP). Using [14C]phenanthrene as a radiotracer, we verified that only HASP isolates were capable of mineralizing HASP, a phenotype hence termed “competence.” Competence was an all-or-nothing phenotype: noncompetent strains showed no detectable phenanthrene mineralization in HASP cultures, but levels of phenanthrene mineralization effected by competent strains in HASP and NSP cultures were not significantly different. Levels and rates of phenanthrene mineralization exceeded those predicted to be supported solely by the metabolism of phenanthrene in the aqueous phase of HASP cultures. Thus, competent strains were able to directly access phenanthrene sorbed by the humic acids and did not rely on desorption for substrate uptake. To the best of our knowledge, this is the first report of (i) a selective interaction between aerobic bacteria and humic acid molecules and (ii) differential bioavailability to bacteria of PAHs sorbed to a natural biogeopolymer. PMID:16000791

Isolation and characterization of new strains of cholesterol-reducing bacteria from baboons.

PubMed

Brinkley, A W; Gottesman, A R; Mott, G E

1982-01-01

We isolated and characterized nine new strains of cholesterol-reducing bacteria from feces and intestinal contents of baboons. Cholesterol-brain agar was used for the primary isolation, and subsequent biochemical tests were done in a lecithin-cholesterol broth containing plasmenylethanolamine and various substrates. All strains had similar colony and cell morphology, hydrolyzed the beta-glucosides esculin and amygdalin, metabolized pyruvate, and produced acetate and acetoin. Unlike previously reported strains, the nine new strains did not require cholesterol and an alkenyl ether lipid (e.g., plasmalogen) for growth; however, only two strains reduced cholesterol in the absence of the plasmalogen. These two strains also produced succinate as an end product. Carbohydrate fermentation was variable; some strains produced weak acid (pH 5.5 to 6.0) from only a few carbohydrates, whereas other strains produced strong acid reactions (pH less than or equal to 5.5) from a wide variety of carbohydrates.

Biohydrogenation of C20 polyunsaturated fatty acids by anaerobic bacteria.

PubMed

Sakurama, Haruko; Kishino, Shigenobu; Mihara, Kousuke; Ando, Akinori; Kita, Keiko; Takahashi, Satomi; Shimizu, Sakayu; Ogawa, Jun

2014-09-01

The PUFAs include many bioactive lipids. The microbial metabolism of C18 PUFAs is known to produce their bioactive isomers, such as conjugated FAs and hydroxy FAs, but there is little information on that of C20 PUFAs. In this study, we aimed to obtain anaerobic bacteria with the ability to produce novel PUFAs from C20 PUFAs. Through the screening of ∼100 strains of anaerobic bacteria, Clostridium bifermentans JCM 1386 was selected as a strain with the ability to saturate PUFAs during anaerobic cultivation. This strain converted arachidonic acid (cis-5,cis-8,cis-11,cis-14-eicosatetraenoic acid) and EPA (cis-5,cis-8,cis-11,cis-14,cis-17-EPA) into cis-5,cis-8,trans-13-eicosatrienoic acid and cis-5,cis-8,trans-13,cis-17-eicosatetraenoic acid, giving yields of 57% and 67% against the added PUFAs, respectively. This is the first report of the isolation of a bacterium transforming C20 PUFAs into corresponding non-methylene-interrupted FAs. We further investigated the substrate specificity of the biohydrogenation by this strain and revealed that it can convert two cis double bonds at the ω6 and ω9 positions in various C18 and C20 PUFAs into a trans double bond at the ω7 position. This study should serve to open up the development of novel potentially bioactive PUFAs. Copyright © 2014 by the American Society for Biochemistry and Molecular Biology, Inc.

Prevention by lactic acid bacteria of the oxidation of human LDL.

PubMed

Terahara, M; Kurama, S; Takemoto, N

2001-08-01

Ether extracts of lactic acid bacteria were analyzed for prevention of the oxidation of erythrocyte membrane and human low-density lipoprotein in vivo. Streptococcus thermophilus 1131 and Lactobacillus delbrueckii subsp. bulgaricus 2038, yogurt starters, were chosen as test-strains, and ether extracts of these cultures were used as samples. Both strain 1131 and strain 2038 produced radical scavengers and inhibited oxidation of erythrocyte membranes and low-density lipoproteins. The antioxidative activity of strain 2038 was higher than that of strain 1131.

[Comparative genomics and evolutionary analysis of CRISPR loci in acetic acid bacteria].

PubMed

Xia, Kai; Liang, Xin-le; Li, Yu-dong

2015-12-01

The clustered regularly interspaced short palindromic repeat (CRISPR) is a widespread adaptive immunity system that exists in most archaea and many bacteria against foreign DNA, such as phages, viruses and plasmids. In general, CRISPR system consists of direct repeat, leader, spacer and CRISPR-associated sequences. Acetic acid bacteria (AAB) play an important role in industrial fermentation of vinegar and bioelectrochemistry. To investigate the polymorphism and evolution pattern of CRISPR loci in acetic acid bacteria, bioinformatic analyses were performed on 48 species from three main genera (Acetobacter, Gluconacetobacter and Gluconobacter) with whole genome sequences available from the NCBI database. The results showed that the CRISPR system existed in 32 species of the 48 strains studied. Most of the CRISPR-Cas system in AAB belonged to type I CRISPR-Cas system (subtype E and C), but type II CRISPR-Cas system which contain cas9 gene was only found in the genus Acetobacter and Gluconacetobacter. The repeat sequences of some CRISPR were highly conserved among species from different genera, and the leader sequences of some CRISPR possessed conservative motif, which was associated with regulated promoters. Moreover, phylogenetic analysis of cas1 demonstrated that they were suitable for classification of species. The conservation of cas1 genes was associated with that of repeat sequences among different strains, suggesting they were subjected to similar functional constraints. Moreover, the number of spacer was positively correlated with the number of prophages and insertion sequences, indicating the acetic acid bacteria were continually invaded by new foreign DNA. The comparative analysis of CRISR loci in acetic acid bacteria provided the basis for investigating the molecular mechanism of different acetic acid tolerance and genome stability in acetic acid bacteria.

Metabolism of the 18O-methoxy substituent of 3-methoxybenzoic acid and other unlabeled methoxybenzoic acids by anaerobic bacteria.

PubMed Central

DeWeerd, K A; Saxena, A; Nagle, D P; Suflita, J M

1988-01-01

O-methyl substituents of aromatic compounds can provide C1 growth substrates for facultative and strict anaerobic bacteria isolated from diverse environments. The mechanism of the bioconversion of methoxylated benzoic acids to the hydroxylated derivatives was investigated with a model substrate and cultures of one anaerobic consortium, eight strict anaerobic bacteria, and one facultative anaerobic microorganism. Using high-pressure liquid chromatography and gas chromatography-mass spectral analysis, we found that a haloaromatic dehalogenating consortium, a dehalogenating isolate from that consortium, Eubacterium limosum, and a strain of Acetobacterium woodii metabolized 3-[methoxy-18O]methoxybenzoic acid (3-anisic acid) to 3-[hydroxy-18O]hydroxybenzoic acid stoichiometrically at rates of 1.5, 3.2, 52.4, and 36.7 nmol/min per mg of protein, respectively. A different strain of Acetobacterium and strains of Syntrophococcus, Clostridium, Desulfotomaculum, Enterobacter, and an anaerobic bacterium, strain TH-001, were unable to transform this compound. The O-demethylating ability of E. limosum was induced only with appropriate methoxylated benzoates but not with D-glucose, lactate, isoleucine, or methanol. Cross-acclimation and growth experiments with E. limosum showed a rate of metabolism that was an order of magnitude slower and showed no growth with either 4-methoxysalicylic acid (2-hydroxy-4-methoxybenzoic acid) or 4-anisic acid (4-methoxybenzoic acid) when adapted to 3-anisic acid. However, A. woodii NZva-16 showed slower rates and no growth with 3- or 4-methoxysalicylic acid when adapted to 3-anisic acid in similar experiments. The results clearly indicate a methyl rather than methoxy group removal mechanism for such reactions. PMID:3389815

Preliminary Analysis of Lipids and Fatty Acids of Green Bacteria and Chloroflexus aurantiacus

PubMed Central

Kenyon, Christine N.; Gray, Alane M.

1974-01-01

The complex lipids and fatty acids of the seven type species of green bacteria and three strains of Chloroflexus aurantiacus were analyzed. The green bacteria contained lipids that behaved as cardiolipin and phosphatidylglycerol on thin-layer chromatography. They did not contain phosphatidylethanolamine or phosphatidylserine. Similarly, Chloroflexus contained lipids that behaved as phosphatidylglycerol and phosphatidylinositol on thin-layer chromatography and did not contain phosphatidylethanolamine or phosphatidylserine. The green bacteria contained glycolipids I and II of Constantopoulos and Bloch (monogalactosyldiglyceride and a galactose- and rhamnose-containing diglyceride). Chloroflexus exhibited galactose-containing glycolipids that behaved identically with the mono- and digalactosyldiglycerides of spinach on thin-layer chromatography, and each contained galactose as well as at least one other sugar. The fatty acids of both groups of bacteria consisted entirely of saturated and monounsaturated fatty acids. In the green bacteria, myristic, palmitic, and hexadecenoic acids predominated. In Chloroflexus, palmitic, stearic, and oleic acids predominated. The positions of the double bonds in the monounsaturated fatty acids of Chloroflexus indicated synthesis by the anaerobic pathway. The lipid analyses suggest a close relationship between the green bacteria and Chloroflexus and further suggest that these groups of photosynthetic bacteria are more closely related to the blue-green algae than are the purple bacteria. Images PMID:4421249

Bactericidal activities of GM flax seedcake extract on pathogenic bacteria clinical strains.

PubMed

Zuk, Magdalena; Dorotkiewicz-Jach, Agata; Drulis-Kawa, Zuzanna; Arendt, Malgorzata; Kulma, Anna; Szopa, Jan

2014-07-29

The antibiotic resistance of pathogenic microorganisms is a worldwide problem. Each year several million people across the world acquire infections with bacteria that are antibiotic-resistant, which is costly in terms of human health. New antibiotics are extremely needed to overcome the current resistance problem. Transgenic flax plants overproducing compounds from phenylpropanoid pathway accumulate phenolic derivatives of potential antioxidative, and thus, antimicrobial activity. Alkali hydrolyzed seedcake extract containing coumaric acid, ferulic acid, caffeic acid, and lignan in high quantities was used as an assayed against pathogenic bacteria (commonly used model organisms and clinical strains). It was shown that the extract components had antibacterial activity, which might be useful as a prophylactic against bacterial infection. Bacteria topoisomerase II (gyrase) inhibition and genomic DNA disintegration are suggested to be the main reason for rendering antibacterial action. The data obtained strongly suggest that the seedcake extract preparation is a suitable candidate for antimicrobial action with a broad spectrum and partial selectivity. Such preparation can be applied in cases where there is a risk of multibacterial infection and excellent answer on global increase in multidrug resistance in pathogenic bacteria.

Exopolysaccharide-producing lactic acid bacteria strains from traditional Thai fermented foods: isolation, identification and exopolysaccharide characterization.

PubMed

Smitinont, T; Tansakul, C; Tanasupawat, S; Keeratipibul, S; Navarini, L; Bosco, M; Cescutti, P

1999-10-15

Lactic Acid Bacteria (LAB) isolated from various traditional Thai fermented foods were screened for exopolysaccharides (EPS) production. From 104 isolates, two rod-shaped and five coccal-shaped LAB were able to produce EPS from sucrose on solid media. However, only the cocci were capable of producing EPS in liquid media and these were identified as Pediococcus pentosaceus. Pediococcus pentosaceus strains AP-1 and AP-3 produced EPS in high yield. In liquid media containing sucrose as carbon source, the amount of EPS produced by AP-1 and AP-3 strains was 6.0 and 2.5 g/L, respectively. The isolated and purified EPSs were chemically characterized. On the basis of sugar composition, methylation analysis and nuclear magnetic resonance spectroscopy, both the EPSs were shown to belong to the same dextran class. In particular, both EPSs differed from linear dextran by branching through 3,6-di-Osubstituted alpha-D-glucopyranosyl residues. The EPS from P. pentosaceus AP-3 was characterized by a relatively higher degree of branching and by a higher molecular weight than that from P. pentosaceus AP-1.

Selection of new lactic acid bacteria strains bearing probiotic features from mucosal microbiota of healthy calves: Looking for immunobiotics through in vitro and in vivo approaches for immunoprophylaxis applications.

PubMed

Sandes, Sávio; Alvim, Luige; Silva, Bruno; Acurcio, Leonardo; Santos, Cinara; Campos, Márcia; Santos, Camila; Nicoli, Jacques; Neumann, Elisabeth; Nunes, Álvaro

2017-07-01

From the birth, since their mucosal microbiota and immune system are not fully developed, newborn calves are susceptible to several mucosal pathogenic microorganisms. Operating through humoral and non-humoral mechanisms in the host, several lactic acid bacteria strains bearing probiotic features are often employed in livestock as food supplement, improving animal production performance, promoting health and reducing the severity of mucosal infections. Accordingly, we isolated, species-level identified and screened for their probiotic potentials seventy lactic acid bacteria strains from upper airway, vaginal and intestinal mucosa of healthy calves. Based on in vitro approaches, we selected three strains: Lactobacillus fermentum V3B-08 isolated from upper airway mucosa, Weissella hellenica V1V-30 isolated from vaginal mucosa and Lactobacillus farciminis B4F-06 isolated from intestinal mucosa were used to mono-colonize germ-free mice in the same site in which these strains were isolated, aiming to characterize their immunomodulatory features. These strains were able to colonize germ-free mice mucosa and trigger sIgA synthesis at a local level, in addition to stimulating, in different ways, adaptive immune responses at a systemic level. Copyright © 2017 Elsevier GmbH. All rights reserved.

The use of lactic acid bacteria to reduce mercury bioaccessibility.

PubMed

Jadán-Piedra, C; Alcántara, C; Monedero, V; Zúñiga, M; Vélez, D; Devesa, V

2017-08-01

Mercury in food is present in either inorganic [Hg(II)] or methylmercury (CH 3 Hg) form. Intestinal absorption of mercury is influenced by interactions with other food components. The use of dietary components to reduce mercury bioavailability has been previously proposed. The aim of this work is to explore the use of lactic acid bacteria to reduce the amount of mercury solubilized after gastrointestinal digestion and available for absorption (bioaccessibility). Ten strains were tested by addition to aqueous solutions containing Hg(II) or CH 3 Hg, or to food samples, and submission of the mixtures to gastrointestinal digestion. All of the strains assayed reduce the soluble fraction from standards of mercury species under gastrointestinal digestion conditions (72-98%). However their effectiveness is lower in food, and reductions in bioaccessibility are only observed with mushrooms (⩽68%). It is hypothesized that bioaccessible mercury in seafood forms part of complexes that do not interact with lactic acid bacteria. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biochemical characterisation of the esterase activities of wine lactic acid bacteria.

PubMed

Matthews, Angela; Grbin, Paul R; Jiranek, Vladimir

2007-11-01

Esters are an important group of volatile compounds that can contribute to wine flavour. Wine lactic acid bacteria (LAB) have been shown to produce esterases capable of hydrolysing ester substrates. This study aims to characterise the esterase activities of nine LAB strains under important wine conditions, namely, acidic conditions, low temperature (to 10 degrees C) and in the presence of ethanol (2-18% v/v). Esterase substrate specificity was also examined using seven different ester substrates. The bacteria were generally found to have a broad pH activity range, with the majority of strains showing maximum activity close to pH 6.0. Exceptions included an Oenococcus oeni strain that retained most activity even down to a pH of 4.0. Most strains exhibited highest activity across the range 30-40 degrees C. Increasing ethanol concentration stimulated activity in some of the strains. In particular, O. oeni showed an increase in activity up to a maximum ethanol concentration of around 16%. Generally, strains were found to have greater activity towards short-chained esters (C2-C8) compared to long-chained esters (C10-C18). Even though the optimal physicochemical conditions for enzyme activity differed from those found in wine, these findings are of potential importance to oenology because significant activities remained under wine-like conditions.

[Design of primers to DNA of lactic acid bacteria].

PubMed

Lashchevskiĭ, V V; Kovalenko, N K

2003-01-01

Primers LP1-LP2 to the gene 16S rRNA have been developed, which permit to differentiate lactic acid bacteria: Lactobacillus plantarum, L. delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus. The strain-specific and species-specific differentiations are possible under different annealing temperature. Additional fragments, which are synthesized outside the framework of gene 16S rRNA reading, provide for the strain-specific type of differentiation, and the fragment F864 read in the gene 16S rRNA permits identifying L. plantarum.

Isolating and evaluating lactic acid bacteria strains for effectiveness on silage quality at low temperatures on the Tibetan Plateau.

PubMed

Wang, Siran; Yuan, Xianjun; Dong, Zhihao; Li, Junfeng; Shao, Tao

2017-11-01

Four lactic acid bacteria (LAB) strains isolated from straw silages on the Tibetan Plateau were characterized, and their effects on the fermentation quality of Italian ryegrass (Lolium multiflorum Lam.) at different temperatures (10°C, 15°C and 25°C) were studied. These LAB isolates were evaluated using the acids production ability test, morphological observation, Gram staining, physiological, biochemical and acid tolerance tests. All the isolates (M1, LM8, LO7 and LOG9) could grow at 5-20°C, pH 3.5-7.0 and NaCl (3.0%, 6.5%). Strains M1, LM8, LO7 and LOG9 were identified as Lactobacillus plantarum, L. coryniformis, Pediococcus pentosaceus and P. acidilactici, respectively, by sequencing 16S ribosomal DNA. The four isolates were added to Italian ryegrass for ensiling for 30 days at various temperatures. Compared with the corresponding control, inoculating with isolates M1, LM8 and LO7 could improve the silage quality of Italian ryegrass at low temperatures, indicated by significantly (P < 0.05) higher lactic acid (LA) contents and ratios of lactic acid/acetic acid (LA/AA), and significantly (P < 0.05) lower pH and ammonia nitrogen/total nitrogen (AN/TN). Compared with other isolates, LM8 performed better at 10°C and 15°C, indicated by the higher (P < 0.05) LA content and ratio of LA/AA, and the lower (P < 0.05) pH and AN/TN. © 2017 Japanese Society of Animal Science.

In vitro testing of commercial and potential probiotic lactic acid bacteria.

PubMed

Jensen, Hanne; Grimmer, Stine; Naterstad, Kristine; Axelsson, Lars

2012-02-01

Probiotics are defined as live microorganisms which when administered in adequate amounts confer a health benefit on the host. The objective of this study was to investigate the diversity of selected commercial and potential probiotic lactic acid bacteria using common in vitro screening assays such as transit tolerance in the upper human gastrointestinal tract, adhesion capacity to human intestinal cell lines and effect on epithelial barrier function. The selected bacteria include strains of Lactobacillus plantarum, Lactobacillus pentosus, Lactobacillus farciminis, Lactobacillus sakei, Lactobacillus gasseri, Lactobacillus rhamnosus, Lactobacillus reuteri and Pediococcus pentosaceus. Viable counts after simulated gastric transit tolerance showed that L. reuteri strains and P. pentosaceus tolerate gastric juice well, with no reduction of viability, whereas L. pentosus, L. farciminis and L. sakei strains lost viability over 180min. All strains tested tolerate the simulated small intestinal juice well. The bacterial adhesion capacity to human intestinal cells revealed major species and strain differences. Overall, L. plantarum MF1298 and three L. reuteri strains had a significant higher adhesion capacity compared to the other strains tested. All strains, both living and UV-inactivated, had little effect on the epithelial barrier function. However, living L. reuteri strains revealed a tendency to increase the transepithelial electrical resistance (TER) from 6 to 24h. This work demonstrates the diversity of 18 potential probiotic bacteria, with major species and strain specific effects in the in vitro screening assays applied. Overall, L. reuteri strains reveal some interesting characteristics compared to the other strains investigated. Copyright © 2011 Elsevier B.V. All rights reserved.

In Vitro Characterization of Lactic Acid Bacteria Isolated from Bovine Milk as Potential Probiotic Strains to Prevent Bovine Mastitis.

PubMed

Pellegrino, Matías S; Frola, Ignacio D; Natanael, Berardo; Gobelli, Dino; Nader-Macias, María E F; Bogni, Cristina I

2018-01-02

Bovine mastitis causes economic losses on dairy farms worldwide. Lactic acid bacteria (LAB) in animal health are an alternative tool to avoid antibiotic therapy on the prevention of bovine mastitis. In previous studies, 12 LAB isolated from bovine milk were selected taking into account some of the following characteristics: hydrophobicity, auto aggregative capability, inhibition of indicator pathogens, hydrogen peroxide, and capsular polysaccharide production. These LAB were considered because of their beneficial properties. In this work, we also analyzed the antimicrobial activity and the co-aggregation against mastitis causing bacteria, auto-inhibition, adhesion to bovine teat canal epithelial cells (BTCEC), and growth kinetic curves for the 12 LAB. Two of them, Lactococcus lactis subsp. lactis CRL 1655 and Lactobacillus perolens CRL 1724, were selected because they had an interesting pattern of adhesion to BTEC, the inhibition of pathogens and the co-aggregation with the 100% of the assayed pathogens. They showed a predictable difference in the PFGE genomic pattern bands. The kinetic growth of these two strains was similar between them and with the rest of the assayed LAB. The strains selected in the present study showed indispensable characteristics for their inclusion in a probiotic formulation to be used at dry-off period for the prevention of bovine mastitis.

Metabolism of Oxo-Bile Acids and Characterization of Recombinant 12α-Hydroxysteroid Dehydrogenases from Bile Acid 7α-Dehydroxylating Human Gut Bacteria.

PubMed

Doden, Heidi; Sallam, Lina A; Devendran, Saravanan; Ly, Lindsey; Doden, Greta; Daniel, Steven L; Alves, João M P; Ridlon, Jason M

2018-05-15

Bile acids are important cholesterol-derived nutrient signaling hormones, synthesized in the liver, that act as detergents to solubilize dietary lipids. Bile acid 7α-dehydroxylating gut bacteria generate the toxic bile acids deoxycholic acid and lithocholic acid from host bile acids. The ability of these bacteria to remove the 7-hydroxyl group is partially dependent on 7α-hydroxysteroid dehydrogenase (HSDH) activity, which reduces 7-oxo-bile acids generated by other gut bacteria. 3α-HSDH has an important enzymatic activity in the bile acid 7α-dehydroxylation pathway. 12α-HSDH activity has been reported for the low-activity bile acid 7α-dehydroxylating bacterium Clostridium leptum ; however, this activity has not been reported for high-activity bile acid 7α-dehydroxylating bacteria, such as Clostridium scindens , Clostridium hylemonae , and Clostridium hiranonis Here, we demonstrate that these strains express bile acid 12α-HSDH. The recombinant enzymes were characterized from each species and shown to preferentially reduce 12-oxolithocholic acid to deoxycholic acid, with low activity against 12-oxochenodeoxycholic acid and reduced activity when bile acids were conjugated to taurine or glycine. Phylogenetic analysis suggests that 12α-HSDH is widespread among Firmicutes , Actinobacteria in the Coriobacteriaceae family, and human gut Archaea IMPORTANCE 12α-HSDH activity has been established in the medically important bile acid 7α-dehydroxylating bacteria C. scindens , C. hiranonis , and C. hylemonae Experiments with recombinant 12α-HSDHs from these strains are consistent with culture-based experiments that show a robust preference for 12-oxolithocholic acid over 12-oxochenodeoxycholic acid. Phylogenetic analysis identified novel members of the gut microbiome encoding 12α-HSDH. Future reengineering of 12α-HSDH enzymes to preferentially oxidize cholic acid may provide a means to industrially produce the therapeutic bile acid ursodeoxycholic acid. In

Comparative Studies of Class IIa Bacteriocins of Lactic Acid Bacteria

PubMed Central

Eijsink, Vincent G. H.; Skeie, Marianne; Middelhoven, P. Hans; Brurberg, May Bente; Nes, Ingolf F.

1998-01-01

Four class IIa bacteriocins (pediocin PA-1, enterocin A, sakacin P, and curvacin A) were purified to homogeneity and tested for activity toward a variety of indicator strains. Pediocin PA-1 and enterocin A inhibited more strains and had generally lower MICs than sakacin P and curvacin A. The antagonistic activity of pediocin-PA1 and enterocin A was much more sensitive to reduction of disulfide bonds than the antagonistic activity of sakacin P and curvacin A, suggesting that an extra disulfide bond that is present in the former two may contribute to their high levels of activity. The food pathogen Listeria monocytogenes was among the most sensitive indicator strains for all four bacteriocins. Enterocin A was most effective in inhibiting Listeria, having MICs in the range of 0.1 to 1 ng/ml. Sakacin P had the interesting property of being very active toward Listeria but not having concomitant high levels of activity toward lactic acid bacteria. Strains producing class IIa bacteriocins displayed various degrees of resistance toward noncognate class IIa bacteriocins; for the sakacin P producer, it was shown that this resistance is correlated with the expression of immunity genes. It is hypothesized that variation in the presence and/or expression of such immunity genes accounts in part for the remarkably large variation in bacteriocin sensitivity displayed by lactic acid bacteria. PMID:9726871

[Characteristics of natural strains of naphthalene-utilizing bacteria of the genus Pseudomonas].

PubMed

Levchuk, A A; Vasilenko, S L; Bulyga, I M; Titok, M A; Thomas, K M

2005-01-01

Sixty-three strains of bacteria capable of utilizing naphthalene as the sole source of carbon and energy were isolated from 137 samples of soil taken in different sites in Belarus. All isolated bacteria contained extrachromosomal genetic elements of 45 to 150 kb in length. It was found that bacteria of 31 strains contained the IncP-9 incompatibility group plasmids, bacteria of one strain carried a plasmid containing replicons IncP-9 and IncP-7, and bacteria of 31 strains contained unidentified plasmids. Primary identification showed that the hosts of plasmids of naphthalene biodegradation are fluorescent bacteria of the genus Pseudomonas (P. putida and P. aeruginosa; a total of 47 strains) and unidentified nonfluorescent microorganisms (a total of 16 strains). In addition to the ability to utilize naphthalene, some strains exhibited the ability to stimulate the growth and development of the root system of Secale cereale.

Investigating on the fermentation behavior of six lactic acid bacteria strains in barley malt wort reveals limitation in key amino acids and buffer capacity.

PubMed

Nsogning, Sorelle Dongmo; Fischer, Susann; Becker, Thomas

2018-08-01

Understanding lactic acid bacteria (LAB) fermentation behavior in malt wort is a milestone towards flavor improvement of lactic acid fermented malt beverages. Therefore, this study aims to outline deficiencies that may exist in malt wort fermentation. First, based on six LAB strains, cell viability and vitality were evaluated. Second, sugars, organic acids, amino acids, pH value and buffering capacity (BC) were monitored. Finally, the implication of key amino acids, fructose and wort BC on LAB growth was determined. Short growth phase coupled with prompt cell death and a decrease in metabolic activity was observed. Low wort BC caused rapid pH drop with lactic acid accumulation, which conversely increased the BC leading to less pH change at late-stage fermentation. Lactic acid content (≤3.9 g/L) was higher than the reported inhibitory concentration (1.8 g/L). Furthermore, sugars were still available but fructose and key amino acids lysine, arginine and glutamic acid were considerably exhausted (≤98%). Wort supplementations improved cell growth and viability leading to conclude that key amino acid depletion coupled with low BC limits LAB growth in malt wort. Then, a further increase in organic acid reduces LAB viability. This knowledge opens doors for LAB fermentation process optimization in malt wort. Copyright © 2018 Elsevier Ltd. All rights reserved.

Interactions of organic acids with Salmonella strains from feedlot water-sprinkled cattle

USDA-ARS?s Scientific Manuscript database

Organic acids are commonly used as a carcass wash to remove bacteria during food production. In this study, the interactions of four organic acids with 145 Salmonella strains comprised of six different serovars from feedlot water-sprinkled cattle were studied. The pH was determined at the molar MI...

Comparative Genomics of Syntrophic Branched-Chain Fatty Acid Degrading Bacteria

PubMed Central

Narihiro, Takashi; Nobu, Masaru K.; Tamaki, Hideyuki; Kamagata, Yoichi; Sekiguchi, Yuji; Liu, Wen-Tso

2016-01-01

The syntrophic degradation of branched-chain fatty acids (BCFAs) such as 2-methylbutyrate and isobutyrate is an essential step in the production of methane from proteins/amino acids in anaerobic ecosystems. While a few syntrophic BCFA-degrading bacteria have been isolated, their metabolic pathways in BCFA and short-chain fatty acid (SCFA) degradation as well as energy conservation systems remain unclear. In an attempt to identify these pathways, we herein performed comparative genomics of three syntrophic bacteria: 2-methylbutyrate-degrading “Syntrophomonas wolfei subsp. methylbutyratica” strain JCM 14075T (=4J5T), isobutyrate-degrading Syntrophothermus lipocalidus strain TGB-C1T, and non-BCFA-metabolizing S. wolfei subsp. wolfei strain GöttingenT. We demonstrated that 4J5 and TGB-C1 both encode multiple genes/gene clusters involved in β-oxidation, as observed in the Göttingen genome, which has multiple copies of genes associated with butyrate degradation. The 4J5 genome possesses phylogenetically distinct β-oxidation genes, which may be involved in 2-methylbutyrate degradation. In addition, these Syntrophomonadaceae strains harbor various hydrogen/formate generation systems (i.e., electron-bifurcating hydrogenase, formate dehydrogenase, and membrane-bound hydrogenase) and energy-conserving electron transport systems, including electron transfer flavoprotein (ETF)-linked acyl-CoA dehydrogenase, ETF-linked iron-sulfur binding reductase, ETF dehydrogenase (FixABCX), and flavin oxidoreductase-heterodisulfide reductase (Flox-Hdr). Unexpectedly, the TGB-C1 genome encodes a nitrogenase complex, which may function as an alternative H2 generation mechanism. These results suggest that the BCFA-degrading syntrophic strains 4J5 and TGB-C1 possess specific β-oxidation-related enzymes for BCFA oxidation as well as appropriate energy conservation systems to perform thermodynamically unfavorable syntrophic metabolism. PMID:27431485

Enological Qualities and Interactions Between Native Yeast and Lactic Acid Bacteria from Queretaro, Mexico.

PubMed

Miranda-Castilleja, Dalia E; Martínez-Peniche, Ramón Á; Nadal Roquet-Jalmar, Montserrat; Aldrete-Tapia, J Alejandro; Arvizu-Medrano, Sofía M

2018-06-15

Despite the importance of strain compatibility, most of the enological strain selection studies are carried out separately on yeasts and lactic acid bacteria (LAB). In this study, the enological traits and interactions between native yeasts and LAB were studied. The H 2 S and acetic acid production, growth rates at 8 °C, killer phenotypes, flocculation, and tolerance to must and wine inhibitors were determined for 25 Saccharomyces yeasts. The ability to grow under two wine-like conditions was also determined in 37 LAB (Oenococcus oeni and Lactobacillus plantarum). The yeast-LAB compatibility of selected strains was tested in a sequential scheme. Finally, microvinification trials were performed using two strains from each group to determine the efficiencies and quality parameters. The phenotypic characterization by the K-means and hierarchical clusters indicated a correlation between flocculation and optical density increase in simulated must and wine medium (r = -0.415) and grouped the prominent yeasts SR19, SR26, and N05 as moderately flocculent, killer, acid producing, and highly tolerant strains. Among the LAB, L. plantarum FU39 grew 230% more than the rest. With regard to interactions, LAB growth stimulation (14-fold on average) due to the previous action of yeasts, particularly of SR19, was observed. The final quality of all wines was similar, but yeast SR19 performed a faster and more efficient fermentation than did N05, Also L. plantarum FU39 fermented faster than did O. oeni VC32. The use of quantitative data, and multivariate analyses allowed an integrative approach to the selection of a compatible and efficient pair of enological yeast-LAB strains. An alternative scheme is proposed for the joint selection of yeast and lactic acid bacteria strains, which allows us to foresee the interactions that may occur between them during winemaking. The kinetic parameters, turbidimetrically measured and analyzed by multivariate methods, simplify the detection of

Lactic acid bacteria isolated from apples are able to catabolise arginine.

PubMed

Savino, María J; Sánchez, Leandro A; Saguir, Fabiana M; de Nadra, María C Manca

2012-03-01

We investigated the potentiality of lactic acid bacteria (LAB) isolated from two apples variety to utilize arginine at different initial pH values. Apples surface contained average levels of bacteria ranging from log 2.49 ± 0.53 to log 3.73 ± 0.48 cfu/ml for Red Delicious and Golden Delicious varieties, respectively. Thirty-one strains able to develop in presence of arginine at low pH were phenotypically and genotipically identified as belonging to Lactobacillus, Pediococcus and Leuconostoc genera. In general, they did not produce ammonia from arginine when cultivated in basal medium with arginine (BMA) at pH 4.5 or 5.2. When this metabolite was quantified only six strains belonging to Leuconostoc dextranicum, Lactobacillus brevis and Lactobacillus plantarum species formed higher ammonia amounts in BMA as compared to control. This was correlated with arginine utilization and it was more pronounced at pH 4.5 than 5.2. Analysis of citrulline production confirmed the arginine utilization in these bacteria by the arginine deiminase (ADI) pathway. Maxima citrulline production was observed for Lactobacillus brevis M15 at the two pH values. In this strain ammonia was formed at higher rate than citrulline, which was detected in concentration lower than 1 mM. Thus, main LAB species found on apple surfaces with abilities to degrade arginine by the ADI pathway under different conditions were reported here at the first time. The results suggested that the ADI pathway in apples LAB might not be mainly relevant for their survival in the acid natural environmental, despite leading to the ammonia formation, which may contribute to the increase in pH, coping the acid stress.

Unravelling the contribution of lactic acid bacteria and acetic acid bacteria to cocoa fermentation using inoculated organisms.

PubMed

Ho, Van Thi Thuy; Fleet, Graham H; Zhao, Jian

2018-08-20

Cocoa beans (Theobroma cacao L.) are the raw material for chocolate production. Fermentation of the bean pulp by microorganisms is essential for developing the precursors of chocolate flavour. Currently, the cocoa fermentation is still conducted by an uncontrolled traditional process via a consortium of indigenous species of yeasts, lactic acid bacteria and acetic acid bacteria. Although the essential contribution of yeasts to the production of good quality beans and, typical chocolate character is generally agreed, the roles of lactic acid bacteria and acetic acid bacteria are less certain. The objective of this study was to investigate the contribution of LAB and AAB in cocoa bean fermentation by conducting small scale laboratory fermentations under aseptic conditions, inoculated with different groups of microorganisms previously isolated from spontaneous cocoa fermentations. The inoculation protocols were: (1) four yeasts Hanseniaspora guilliermondii, Pichia kudriavzevii, Kluyveromyces marxianus and Saccharomyces cerevisiae; (2) four yeasts plus the lactic acid bacteria Lactobacillus plantarum and Lactobacillus fermentum; (3) four yeasts plus the acetic acid bacteria Acetobacter pasteurianus and Gluconobacter frateuri and (4) four yeasts plus two lactic acid bacteria and two acetic acid bacteria. Only the inoculated species were detected in the microbiota of their respective fermentations. Beans from the inoculated fermentations showed no significant differences in colour, shell weights and concentrations of residual sugars, alcohols and esters (p>0.05), but they were slightly different in contents of lactic acid and acetic acid (p<0.05). All beans were fully brown and free of mould. Residual sugar levels were less than 2.6 mg/g while the shell contents and ethanol were in the range of 11-13.4% and 4.8-7 mg/g, respectively. Beans fermented in the presence of LAB contained higher levels of lactic acid (0.6-1.2 mg/g) whereas higher concentrations of acetic acid

Identification and characterization of thermotolerant acetic acid bacteria strains isolated from coconut water vinegar in Sri Lanka.

PubMed

Perumpuli, P A B N; Watanabe, Taisuke; Toyama, Hirohide

2014-01-01

From the pellicle formed on top of brewing coconut water vinegar in Sri Lanka, three Acetobacter strains (SL13E-2, SL13E-3, and SL13E-4) that grow at 42 °C and four Gluconobacter strains (SL13-5, SL13-6, SL13-7, and SL13-8) grow at 37 °C were identified as Acetobacter pasteurianus and Gluconobacter frateurii, respectively. Acetic acid production by the isolated Acetobacter strains was examined. All three strains gave 4% acetic acid from 6% initial ethanol at 37 °C, and 2.5% acetic acid from 4% initial ethanol at 40 °C. Compared with the two other strains, SL13E-4 showed both slower growth and slower acetic acid production. As well as the thermotolerant SKU1108 strain, the activities of the alcohol dehydrogenase and the aldehyde dehydrogenase of SL13E-2 and SL13E-4 were more stable than those of the mesophilic strain. The isolated strains were used to produce coconut water vinegar at higher temperatures than typically used for vinegar production.

Acetic acid bacteria in traditional balsamic vinegar: phenotypic traits relevant for starter cultures selection.

PubMed

Gullo, Maria; Giudici, Paolo

2008-06-30

This review focuses on acetic acid bacteria in traditional balsamic vinegar process. Although several studies are available on acetic acid bacteria ecology, metabolism and nutritional requirements, their activity as well as their technological traits in homemade vinegars as traditional balsamic vinegar is not well known. The basic technology to oxidise cooked grape must to produce traditional balsamic vinegar is performed by the so called "seed-vinegar" that is a microbiologically undefined starter culture obtained from spontaneous acetification of previous raw material. Selected starter cultures are the main technological improvement in order to innovate traditional balsamic vinegar production but until now they are rarely applied. To develop acetic acid bacteria starter cultures, selection criteria have to take in account composition of raw material, acetic acid bacteria metabolic activities, applied technology and desired characteristics of the final product. For traditional balsamic vinegar, significative phenotypical traits of acetic acid bacteria have been highlighted. Basic traits are: ethanol preferred and efficient oxidation, fast rate of acetic acid production, tolerance to high concentration of acetic acid, no overoxidation and low pH resistance. Specific traits are tolerance to high sugar concentration and to a wide temperature range. Gluconacetobacter europaeus and Acetobacter malorum strains can be evaluated to develop selected starter cultures since they show one or more suitable characters.

Enrichment of conjugated linoleic acid (CLA) in hen eggs and broiler chickens meat by lactic acid bacteria.

PubMed

Herzallah, Saqer

2013-01-01

1. The aim of this work was to compare conjugated linoleic acid (CLA) concentrations in chickens supplemented with 4 American Tissue Culture Collection (ATCC) bacterial strains, Lactobacillus plantarum, Lactobacillus lactis, Lactobacillus casei and Lactobacillus fermentum, and 4 isolates of Lactobacillus reuteri from camel, cattle, sheep and goat rumen extracts. 2. Micro-organisms were grown anaerobically in MRS broth, and 10(6) CFU/ml of bacteria were administered orally to mixed-sex, 1-d-old broiler chickens weekly for 4 weeks and to 23-week-old layer hens weekly for 6 weeks. 3. The 4 strains were evaluated for their effects on synthesis of CLA in hen eggs and broiler meat cuts. 4. Administration of pure Lactobacillus and isolated L. reuteri strains from camel, cattle, goat and sheep led to significantly increased CLA concentrations of 0.2-1.2 mg/g of fat in eggs and 0.3-1.88 mg/g of fat in broiler chicken flesh homogenates of leg, thigh and breast. 5. These data demonstrate that lactic acid bacteria of animal origin (L. reuteri) significantly enhanced CLA synthesis in both eggs and broiler meat cuts.

Lactic Acid Bateria - Friend or Foe? Lactic Acid Bacteria in the Production of Polysaccharides and Fuel Ethanol

USDA-ARS?s Scientific Manuscript database

Lactic acid bacteria (LAB) have been widely used in the production of fermented foods and as probiotics. Alternan is a glucan with a distinctive backbone structure of alternating alpha-(1,6) and alpha-(1,3) linkages produced by the LAB Leuconostoc mesenteroides. In recent years, improved strains f...

Identification of Lactic Acid Bacteria in Fruit Pulp Processing Byproducts and Potential Probiotic Properties of Selected Lactobacillus Strains

PubMed Central

Garcia, Estefânia F.; Luciano, Winnie A.; Xavier, Danilo E.; da Costa, Whyara C. A.; de Sousa Oliveira, Kleber; Franco, Octávio L.; de Morais Júnior, Marcos A.; Lucena, Brígida T. L.; Picão, Renata C.; Magnani, Marciane; Saarela, Maria; de Souza, Evandro L.

2016-01-01

This study aimed to identify lactic acid bacteria (LAB) in byproducts of fruit (Malpighia glabra L., Mangifera indica L., Annona muricata L., and Fragaria vesca L.) pulp processing. Fifty strains of LAB were identified using matrix-assisted laser desorption/ionization–time of flight mass spectrometry (MALDI-TOF MS) and 16S rRNA gene sequence (16S rRNA) analysis. Species belonging to Lactobacillus genus were the predominant LAB in all fruit pulp processing byproducts. The average congruency between the MALDI-TOF MS and 16S rRNA in LAB species identification reached 86%. Isolates of L. plantarum, L. brevis, L. pentosus, L. lactis and L. mesenteroides were identified with 100% congruency. MALDI-TOF MS and 16S rRNA analysis presented 86 and 100% efficiency of LAB species identification, respectively. Further, five selected Lactobacillus strains (L. brevis 59, L. pentosus 129, L. paracasei 108, L. plantarum 49, and L. fermentum 111) were evaluated for desirable probiotic-related properties and growth behavior on two different cultivation media. The exposure to pH 2.0 sharply decreased the counts of the different Lactobacillus strains after a 1 or 2 h incubation, while varied decreases were noted after 3 h of exposure to pH 3.0. Overall, the exposure to pH 5.0 and to bile salts (0.15, 0.30, and 1.00%) did not decrease the counts of the Lactobacillus strains. All tested Lactobacillus strains presented inhibitory activity against Staphylococcus aureus, Salmonella Typhimurium, Salmonella Enteritidis, Listeria monocytogenes and Escherichia coli, and presented variable susceptibility to different antibiotics. The selected Lactobacillus strains presented satisfactory and reproducible growth behavior. In conclusion, MALDI-TOF MS and 16S rRNA analysis revealed high efficiency and congruency for LAB species identification, and the selected Lactobacillus strains may be candidates for further investigation of novel probiotic strains. PMID:27625647

Dominant lactic acid bacteria and their technological properties isolated from the Himalayan ethnic fermented milk products.

PubMed

Dewan, Sailendra; Tamang, Jyoti Prakash

2007-10-01

Ethnic people of the Himalayan regions of India, Nepal, Bhutan and China consume a variety of indigenous fermented milk products made from cows milk as well as yaks milk. These lesser-known ethnic fermented foods are dahi, mohi, chhurpi, somar, philu and shyow. The population of lactic acid bacteria (LAB) ranged from 10(7) to 10(8) cfu/g in these Himalayan milk products. A total of 128 isolates of LAB were isolated from 58 samples of ethnic fermented milk products collected from different places of India, Nepal and Bhutan. Based on phenotypic characterization including API sugar test, the dominant lactic acid bacteria were identified as Lactobacillus bifermentans, Lactobacillus paracasei subsp. pseudoplantarum, Lactobacillus kefir, Lactobacillus hilgardii, Lactobacillus alimentarius, Lactobacillus paracasei subsp. paracasei, Lactobacillus plantarum, Lactococcus lactis subsp. lactis, Lactococcus lactis subsp. cremoris and Enterococcus faecium. LAB produced a wide spectrum of enzymes and showed high galactosidase, leucine-arylamidase and phosphatase activities. They showed antagonistic properties against selected Gram-negative bacteria. None of the strains produced bacteriocin and biogenic amines under the test conditions used. Most strains of LAB coagulated skim milk with a moderate drop in pH. Some strains of LAB showed a high degree of hydrophobicity, suggesting these strains may have useful adhesive potential. This paper is the first report on functional lactic acid bacterial composition in some lesser-known ethnic fermented milk products of the Himalayas.

Enhanced fatty acid production in engineered chemolithoautotrophic bacteria using reduced sulfur compounds as energy sources

DOE PAGES

Beller, Harry R.; Zhou, Peng; Jewell, Talia N. M.; ...

2016-07-05

Chemolithoautotrophic bacteria that oxidize reduced sulfur compounds, such as H 2 S, while fixing CO 2 are an untapped source of renewable bioproducts from sulfide-laden waste, such as municipal wastewater. In this study, we report engineering of the chemolithoautotrophic bacterium Thiobacillus denitrificans to produce up to 52-fold more fatty acids than the wild-type strain when grown with thiosulfate and CO 2 . A modified thioesterase gene from E. coli ('tesA) was integrated into the T. denitrificans chromosome under the control of P kan or one of two native T. denitrificans promoters. The relative strength of the two native promoters asmore » assessed by fatty acid production in engineered strains was very similar to that assessed by expression of the cognate genes in the wild-type strain. This proof-of-principle study suggests that engineering sulfide-oxidizing chemolithoautotrophic bacteria to overproduce fatty acid-derived products merits consideration as a technology that could simultaneously produce renewable fuels/chemicals as well as cost-effectively remediate sulfide-contaminated wastewater.« less

Exploring the Microbiota of Faba Bean: Functional Characterization of Lactic Acid Bacteria.

PubMed

Verni, Michela; Wang, Changyin; Montemurro, Marco; De Angelis, Maria; Katina, Kati; Rizzello, Carlo G; Coda, Rossana

2017-01-01

This study investigated the metabolic traits of 27 lactic acid bacteria (LAB) strains belonging to different species, previously isolated from faba bean. The activities assayed, related to technological and nutritional improvement of fermented faba bean, included peptidases, β-glucosidase, phytase, as well as exopolysaccharides synthesis and antimicrobial properties. In addition, the bacteria performance as starter cultures during faba bean fermentation on proteolysis, antioxidant potential, and degradation of condensed tannins were assessed. Fermentative profiling showed that only 7 out of 27 strains were able to metabolize D-raffinose, particularly Leuc. mesenteroides I01 and I57. All strains of Pediococcus pentosaceus exerted high PepN activity and exhibited β-glucosidase activity higher than the median value of 0.015 U, while phytase activity was largely distributed among the different strains. All the weissellas, and in lower amount leuconostocs, showed ability to produce EPS from sucrose. None of the strains did not survive the simulated gastrointestinal tract with the exception of P. pentosaceus I56, I76, 147, I214, having a viability of 8-9 log CFU/ml at the end of the treatment. None of the strains showed antimicrobial activity toward Staphylococcus aureus , while eight strains of P. pentosaceus exhibited a strong inhibitory activity toward Escherichia coli and Listeria monocytogenes . Generally, the doughs fermented with pediococci exhibited high amount of total free amino acids, antioxidant activity, and condensed tannins degradation. These results allowed the identification of LAB biotypes as potential starter cultures for faba bean bioprocessing, aiming at the enhancement of faba bean use in novel food applications.

Exploring the Microbiota of Faba Bean: Functional Characterization of Lactic Acid Bacteria

PubMed Central

Verni, Michela; Wang, Changyin; Montemurro, Marco; De Angelis, Maria; Katina, Kati; Rizzello, Carlo G.; Coda, Rossana

2017-01-01

This study investigated the metabolic traits of 27 lactic acid bacteria (LAB) strains belonging to different species, previously isolated from faba bean. The activities assayed, related to technological and nutritional improvement of fermented faba bean, included peptidases, β-glucosidase, phytase, as well as exopolysaccharides synthesis and antimicrobial properties. In addition, the bacteria performance as starter cultures during faba bean fermentation on proteolysis, antioxidant potential, and degradation of condensed tannins were assessed. Fermentative profiling showed that only 7 out of 27 strains were able to metabolize D-raffinose, particularly Leuc. mesenteroides I01 and I57. All strains of Pediococcus pentosaceus exerted high PepN activity and exhibited β-glucosidase activity higher than the median value of 0.015 U, while phytase activity was largely distributed among the different strains. All the weissellas, and in lower amount leuconostocs, showed ability to produce EPS from sucrose. None of the strains did not survive the simulated gastrointestinal tract with the exception of P. pentosaceus I56, I76, 147, I214, having a viability of 8–9 log CFU/ml at the end of the treatment. None of the strains showed antimicrobial activity toward Staphylococcus aureus, while eight strains of P. pentosaceus exhibited a strong inhibitory activity toward Escherichia coli and Listeria monocytogenes. Generally, the doughs fermented with pediococci exhibited high amount of total free amino acids, antioxidant activity, and condensed tannins degradation. These results allowed the identification of LAB biotypes as potential starter cultures for faba bean bioprocessing, aiming at the enhancement of faba bean use in novel food applications. PMID:29312174

Isolation of lactic acid bacteria from swine milk and characterization of potential probiotic strains with antagonistic effects against swine-associated gastrointestinal pathogens.

PubMed

Quilodrán-Vega, Sandra Rayén; Villena, Julio; Valdebenito, José; Salas, María José; Parra, Cristian; Ruiz, Alvaro; Kitazawa, Haruki; García, Apolinaria

2016-06-01

Probiotics are usually isolated from the gastrointestinal tract of humans and animals. The search of probiotics in human milk is a recent field of research, as the existence of the human milk microbiome was discovered only about a decade ago. To our knowledge, no reports regarding the potential probiotic effect of bacteria from swine milk have been published. In this work, we isolated several lactic acid bacteria from swine milk and evaluated them for them potential as probiotics. Among the isolated strains, Lactobacillus curvatus TUCO-5E showed antagonistic effects against swine-associated gastrointestinal pathogens. TUCO-5E was able to reduce the growth of enterotoxigenic and enterohemorrhagic Escherichia coli strains as well as pathogenic salmonella. In vitro exclusion and displacement assays in intestinal epithelial cells showed a remarkable antagonistic effect for L. curvatus TUCO-5E against Salmonella sp. strain TUCO-I7 and Salmonella enterica ATCC 13096. Moreover, by using a mouse model of Salmonella infection, we were able to demonstrate that preventative administration of L. curvatus TUCO-5E for 5 consecutive days was capable of decreasing the number of Salmonella enterica serovar Typhimurium in the liver and spleen of treated mice, compared with the controls, and prevented dissemination of the pathogen to the blood stream. Therefore, we have demonstrated here that swine milk is an interesting source of beneficial bacteria. In addition, the results of this work suggest that L. curvatus TUCO-5E is a good candidate to study in vivo the protective effect of probiotics against intestinal infection and damage induced by Salmonella infection in the porcine host.

Simultaneous production of acetic and gluconic acids by a thermotolerant Acetobacter strain during acetous fermentation in a bioreactor.

PubMed

Mounir, Majid; Shafiei, Rasoul; Zarmehrkhorshid, Raziyeh; Hamouda, Allal; Ismaili Alaoui, Mustapha; Thonart, Philippe

2016-02-01

The activity of bacterial strains significantly influences the quality and the taste of vinegar. Previous studies of acetic acid bacteria have primarily focused on the ability of bacterial strains to produce high amounts of acetic acid. However, few studies have examined the production of gluconic acid during acetous fermentation at high temperatures. The production of vinegar at high temperatures by two strains of acetic acid bacteria isolated from apple and cactus fruits, namely AF01 and CV01, respectively, was evaluated in this study. The simultaneous production of gluconic and acetic acids was also examined in this study. Biochemical and molecular identification based on a 16s rDNA sequence analysis confirmed that these strains can be classified as Acetobacter pasteurianus. To assess the ability of the isolated strains to grow and produce acetic acid and gluconic acid at high temperatures, a semi-continuous fermentation was performed in a 20-L bioreactor. The two strains abundantly grew at a high temperature (41°C). At the end of the fermentation, the AF01 and CV01 strains yielded acetic acid concentrations of 7.64% (w/v) and 10.08% (w/v), respectively. Interestingly, CV01 was able to simultaneously produce acetic and gluconic acids during acetic fermentation, whereas AF01 mainly produced acetic acid. In addition, CV01 was less sensitive to ethanol depletion during semi-continuous fermentation. Finally, the enzymatic study showed that the two strains exhibited high ADH and ALDH enzyme activity at 38°C compared with the mesophilic reference strain LMG 1632, which was significantly susceptible to thermal inactivation. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

[Analysis on the antimicrobial resistance of lactic acid bacteria isolated from the yogurt sold in China].

PubMed

Fan, Qin; Liu, Shuliang; Li, Juan; Huang, Tingting

2012-05-01

To analyze the antimicrobial susceptibility of lactic acid bacteria (LAB) from yogurt, and to provide references for evaluating the safety of LAB and screening safe strains. The sensitivity of 43 LAB strains, including 14 strains of Streptococcus thermophilus, 12 strains of Lactobacillus acidophilus, 9 strains of Lactobacillus bulgaricus and 8 strains of Bifidobacterium, to 22 antibiotics were tested by agar plate dilution method. All 43 LAB strains were resistant to trimethoprim, nalidixic acid, ciprofloxacin, lomefloxacin, danofloxacin and polymyxin E. Their resistances to kanamycin, tetracycline, clindamycin, doxycycline and cephalothin were varied. The sensitivity to other antibiotics were sensitive or moderate. All isolates were multidrug-resistant. The antimicrobial resistance of tested LAB strains was comparatively serious, and continuously monitoring their antimicrobial resistance and evaluating their safety should be strengthened.

(GTG)5-PCR reference framework for acetic acid bacteria.

PubMed

Papalexandratou, Zoi; Cleenwerck, Ilse; De Vos, Paul; De Vuyst, Luc

2009-11-01

One hundred and fifty-eight strains of acetic acid bacteria (AAB) were subjected to (GTG)(5)-PCR fingerprinting to construct a reference framework for their rapid classification and identification. Most of them clustered according to their respective taxonomic designation; others had to be reclassified based on polyphasic data. This study shows the usefulness of the method to determine the taxonomic and phylogenetic relationships among AAB and to study the AAB diversity of complex ecosystems.

Influence of levan-producing acetic acid bacteria on buckwheat-sourdough breads.

PubMed

Ua-Arak, Tharalinee; Jakob, Frank; Vogel, Rudi F

2017-08-01

Buckwheat sourdoughs supplemented with molasses as natural sucrose source were fermented with levan-producing Gluconobacter (G.) albidus TMW 2.1191 and Kozakia (K.) baliensis NBRC 16680. Cell growth, concomitant levan and low-molecular-weight metabolite production were monitored. Sourdough breads were prepared with different sourdoughs from both strains (24, 30 and 48 h fermentation, respectively) and analyzed with respect to bread volume, crumb hardness and sensory characteristics. During fermentation, levan, acetic and gluconic acids were increasingly produced, while spontaneously co-growing lactic acid bacteria additionally formed acetic and lactic acids. Sourdoughs from both strains obtained upon 24 h of fermentation significantly improved the bread sensory and quality, including higher specific volume as well as lower crumb hardness. Buckwheat doughs containing isolated levan, with similar molecular size and mass compared to in situ produced levan in the sourdough at 48 h, verified the positive effect of levan on bread quality. However, the positive effects of levan were masked to a certain extent by the impact from the natural acidification during fermentations. While levan-producing acetic acid bacteria are a promising alternative for the development of clean-label gluten-free breads without the need of additives, an appropriate balance between acidification and levan production (amount and structure) must be reached. Copyright © 2017 Elsevier Ltd. All rights reserved.

Phenotypic and genotypic characterization of lactic acid bacteria isolated from raw goat milk and effect of farming practices on the dominant species of lactic acid bacteria.

PubMed

Tormo, Hélène; Ali Haimoud Lekhal, Djamila; Roques, C

2015-10-01

Lactic acid bacteria, in particular Lactococcus lactis, play a decisive role in the cheese making process and more particularly in lactic cheeses which are primarily produced on goat dairy farms. The objective of this study was therefore to identify the main lactic acid bacteria found in raw goats' milk from three different regions in France and evaluate if certain farming practices have an effect on the distribution of species of lactic acid bacteria in the various milk samples. Identification at genus or species level was carried out using phenotypic tests and genotypic methods including repetitive element REP-PCR, species-specific PCR and 16S rRNA gene sequencing. The distribution of the main bacterial species in the milk samples varied depending on farms and their characteristics. Out of the 146 strains identified, L. lactis was the dominant species (60% of strains), followed by Enterococcus (38%) of which Enterococcus faecalis and Enterococcus faecium. Within the species L. lactis, L. lactis subsp lactis was detected more frequently than L. lactis subsp cremoris (74% vs. 26%). The predominance of L. lactis subsp cremoris was linked to geographical area studied. It appears that the animals' environment plays a role in the balance between the dominance of L. lactis and enterococci in raw goats' milk. The separation between the milking parlor and the goat shed (vs no separation) and only straw in the bedding (vs straw and hay) seems to promote L. lactis in the milk (vs enterococci). Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of rare sugar D-allulose on acid production and probiotic activities of dairy lactic acid bacteria.

PubMed

Kimoto-Nira, H; Moriya, N; Hayakawa, S; Kuramasu, K; Ohmori, H; Yamasaki, S; Ogawa, M

2017-07-01

It has recently been reported that the rare sugar d-allulose has beneficial effects, including the suppression of postprandial blood glucose elevation in humans, and can be substituted for sucrose as a low-calorie food ingredient. To examine the applications of d-allulose in the dairy industry, we investigated the effects of d-allulose on the acid production of 8 strains of yogurt starter (Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus) and 4 strains of lactococci, including potential probiotic candidates derived from dairy products. Acid production by 2 L. delbrueckii ssp. bulgaricus yogurt starter strains in milk was suppressed by d-allulose, but this phenomenon was also observed in some strains with another sugar (xylose), a sugar alcohol (sorbitol), or both. In contrast, among the dairy probiotic candidates, Lactococcus lactis H61, which has beneficial effects for human skin when drunk as part of fermented milk, was the only strain that showed suppression of acid production in the presence of d-allulose. Strain H61 did not metabolize d-allulose. We did not observe suppression of acid production by strain H61 with the addition of xylose or sorbitol, and xylose and sorbitol were not metabolized by strain H61. The acid production of strain H61 after culture in a constituted medium (tryptone-yeast extract-glucose broth) was also suppressed with the addition of d-allulose, but growth efficiency and sugar fermentation style were not altered. Probiotic activities-such as the angiotensin-converting enzyme inhibitory activity of H61-fermented milk and the superoxide dismutase activity of H61 cells grown in tryptone-yeast extract-glucose broth-were not affected by d-allulose. d-Allulose may suppress acid production in certain lactic acid bacteria without altering their probiotic activity. It may be useful for developing new probiotic dairy products from probiotic strains such as Lactococcus lactis H61. Copyright © 2017 American Dairy Science

Exogenous fatty acid metabolism in bacteria.

PubMed

Yao, Jiangwei; Rock, Charles O

2017-10-01

Bacterial type II fatty acid synthesis (FASII) is a target for novel antibiotic development. All bacteria encode for mechanisms to incorporate exogenous fatty acids, and some bacteria can use exogenous fatty acids to bypass FASII inhibition. Bacteria encode three different mechanisms for activating exogenous fatty acids for incorporation into phospholipid synthesis. Exogenous fatty acids are converted into acyl-CoA in Gammaproteobacteria such as E. coli. Acyl-CoA molecules constitute a separate pool from endogenously synthesized acyl-ACP. Acyl-CoA can be used for phospholipid synthesis or broken down by β-oxidation, but cannot be used for lipopolysaccharide synthesis. Exogenous fatty acids are converted into acyl-ACP in some Gram-negative bacteria. The resulting acyl-ACP undergoes the same fates as endogenously synthesized acyl-ACP. Exogenous fatty acids are converted into acyl-phosphates in Gram-positive bacteria, and can be used for phospholipid synthesis or become acyl-ACP. Only the order Lactobacillales can use exogenous fatty acids to bypass FASII inhibition. FASII shuts down completely in presence of exogenous fatty acids in Lactobacillales, allowing Lactobacillales to synthesize phospholipids entirely from exogenous fatty acids. Inhibition of FASII cannot be bypassed in other bacteria because FASII is only partially down-regulated in presence of exogenous fatty acid or FASII is required to synthesize essential metabolites such as β-hydroxyacyl-ACP. Certain selective pressures such as FASII inhibition or growth in biofilms can select for naturally occurring one step mutations that attenuate endogenous fatty acid synthesis. Although attempts have been made to estimate the natural prevalence of these mutants, culture-independent metagenomic methods would provide a better estimate. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

Engineering lactic acid bacteria for increased industrial functionality.

PubMed

Bron, Peter A; Kleerebezem, Michiel

2011-01-01

Based on their spoilage-preventing and flavor-contributing characteristics, lactic acid bacteria (LAB) are employed as starter cultures for the fermentation of foods and feeds. In addition, several specific LAB strains are marketed on basis of their beneficial effects on the consumer's health, representing an explosively growing market for the products containing these so-called probiotics. Due to this extensive industrial use there is a strong interest in unraveling the molecular mechanisms involved in industrial robustness, cognate stress resistance, and health-promoting phenotypes of these LAB that may vary drastically between different starter and probiotic strains currently marketed. This review describes some of the post-genomic tools developed, as well as their employment for the identification of bacterial effector molecules involved in the aforementioned industrially relevant phenotypes. Furthermore, it addresses possible strategies to exploit such knowledge into the rational design of LAB strains with increased industrial functionality.

Towards lactic acid bacteria-based biorefineries.

PubMed

Mazzoli, Roberto; Bosco, Francesca; Mizrahi, Itzhak; Bayer, Edward A; Pessione, Enrica

2014-11-15

Lactic acid bacteria (LAB) have long been used in industrial applications mainly as starters for food fermentation or as biocontrol agents or as probiotics. However, LAB possess several characteristics that render them among the most promising candidates for use in future biorefineries in converting plant-derived biomass-either from dedicated crops or from municipal/industrial solid wastes-into biofuels and high value-added products. Lactic acid, their main fermentation product, is an attractive building block extensively used by the chemical industry, owing to the potential for production of polylactides as biodegradable and biocompatible plastic alternative to polymers derived from petrochemicals. LA is but one of many high-value compounds which can be produced by LAB fermentation, which also include biofuels such as ethanol and butanol, biodegradable plastic polymers, exopolysaccharides, antimicrobial agents, health-promoting substances and nutraceuticals. Furthermore, several LAB strains have ascertained probiotic properties, and their biomass can be considered a high-value product. The present contribution aims to provide an extensive overview of the main industrial applications of LAB and future perspectives concerning their utilization in biorefineries. Strategies will be described in detail for developing LAB strains with broader substrate metabolic capacity for fermentation of cheaper biomass. Copyright © 2014 Elsevier Inc. All rights reserved.

Characterization of probiotic bacteria involved in fermented milk processing enriched with folic acid.

PubMed

Wu, Zhen; Wu, Jing; Cao, Pei; Jin, Yifeng; Pan, Daodong; Zeng, Xiaoqun; Guo, Yuxing

2017-06-01

Yogurt products fermented with probiotic bacteria are a consumer trend and a challenge for functional food development. So far, limited research has focused on the behavior of the various probiotic strains used in milk fermentation. In the present study, we characterized folic acid production and the sensory and textural characteristics of yogurt products fermented with probiotic bacteria. Yogurt fermented with Lactobacillus plantarum had improved nutrient content and sensory and textural characteristics, but the presence of L. plantarum significantly impaired the growth and survival of Lactobacillus delbrueckii ssp. bulgaricus during refrigerated storage. Overall, L. plantarum was a good candidate for probiotic yogurt fermentation; further studies are needed to understand the major metabolite path of lactic acid bacteria in complex fermentation. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Influence of different yeast/lactic acid bacteria combinations on the aromatic profile of red Bordeaux wine.

PubMed

Gammacurta, Marine; Marchand, Stéphanie; Moine, Virginie; de Revel, Gilles

2017-09-01

The typical fruity aroma of red Bordeaux wines depends on the grape variety but also on microbiological processes, such as alcoholic and malolactic fermentations. These transformations involve respectively the yeast Saccharomyces cerevisiae and the lactic acid bacterium Oenococcus oeni. Both species play a central role in red winemaking but their quantitative and qualitative contribution to the revelation of the organoleptic qualities of wine has not yet been fully described. The aim of this study was to elucidate the influence of sequential inoculation of different yeast and bacteria strains on the aromatic profile of red Bordeaux wine. All microorganisms completed fermentations and no significant difference was observed between tanks regarding the main oenological parameters until 3 months' aging. Regardless of the yeast strain, B28 bacteria required the shortest period to completely degrade the malic acid, compared to the other strain. Quantification of 73 major components highlighted a specific volatile profile corresponding to each microorganism combination. However, the yeast strain appeared to have a predominant effect on aromatic compound levels, as well as on fruity aroma perception. Yeasts had a greater impact on wine quality and have more influence on the aromatic style of red wine than bacteria. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Antifungal sourdough lactic acid bacteria as biopreservation tool in quinoa and rice bread.

PubMed

Axel, Claudia; Brosnan, Brid; Zannini, Emanuele; Furey, Ambrose; Coffey, Aidan; Arendt, Elke K

2016-12-19

The use of sourdough fermented with specific strains of antifungal lactic acid bacteria can reduce chemical preservatives in bakery products. The main objective of this study was to investigate the production of antifungal carboxylic acids after sourdough fermentation of quinoa and rice flour using the antifungal strains Lactobacillus reuteri R29 and Lactobacillus brevis R2Δ as bioprotective cultures and the non-antifungal L. brevis L1105 as a negative control strain. The impact of the fermentation substrate was evaluated in terms of metabolic activity, acidification pattern and quantity of antifungal carboxylic acids. These in situ produced compounds (n=20) were extracted from the sourdough using a QuEChERS method and detected by a new UHPLC-MS/MS chromatography. Furthermore, the sourdough was applied in situ using durability tests against environmental moulds to investigate the biopreservative potential to prolong the shelf life of bread. Organic acid production and TTA values were lowest in rice sourdough. The sourdough fermentation of the different flour substrates generated a complex and significantly different profile of carboxylic acids. Extracted quinoa sourdough detected the greatest number of carboxylic acids (n=11) at a much higher concentration than what was detected from rice sourdough (n=9). Comparing the lactic acid bacteria strains, L. reuteri R29 fermented sourdoughs contained generally higher concentrations of acetic and lactic acid but also the carboxylic acids. Among them, 3-phenyllactic acid and 2-hydroxyisocaproic acid were present at a significant concentration. This was correlated with the superior protein content of quinoa flour and its high protease activity. With the addition of L. reuteri R29 inoculated sourdough, the shelf life was extended by 2 days for quinoa (+100%) and rice bread (+67%) when compared to the non-acidified controls. The L. brevis R2Δ fermented sourdough bread reached a shelf life of 4 days for quinoa (+100%) and

Global insights into acetic acid resistance mechanisms and genetic stability of Acetobacter pasteurianus strains by comparative genomics

NASA Astrophysics Data System (ADS)

Wang, Bin; Shao, Yanchun; Chen, Tao; Chen, Wanping; Chen, Fusheng

2015-12-01

Acetobacter pasteurianus (Ap) CICC 20001 and CGMCC 1.41 are two acetic acid bacteria strains that, because of their strong abilities to produce and tolerate high concentrations of acetic acid, have been widely used to brew vinegar in China. To globally understand the fermentation characteristics, acid-tolerant mechanisms and genetic stabilities, their genomes were sequenced. Genomic comparisons with 9 other sequenced Ap strains revealed that their chromosomes were evolutionarily conserved, whereas the plasmids were unique compared with other Ap strains. Analysis of the acid-tolerant metabolic pathway at the genomic level indicated that the metabolism of some amino acids and the known mechanisms of acetic acid tolerance, might collaboratively contribute to acetic acid resistance in Ap strains. The balance of instability factors and stability factors in the genomes of Ap CICC 20001 and CGMCC 1.41 strains might be the basis for their genetic stability, consistent with their stable industrial performances. These observations provide important insights into the acid resistance mechanism and the genetic stability of Ap strains and lay a foundation for future genetic manipulation and engineering of these two strains.

Global insights into acetic acid resistance mechanisms and genetic stability of Acetobacter pasteurianus strains by comparative genomics.

PubMed

Wang, Bin; Shao, Yanchun; Chen, Tao; Chen, Wanping; Chen, Fusheng

2015-12-22

Acetobacter pasteurianus (Ap) CICC 20001 and CGMCC 1.41 are two acetic acid bacteria strains that, because of their strong abilities to produce and tolerate high concentrations of acetic acid, have been widely used to brew vinegar in China. To globally understand the fermentation characteristics, acid-tolerant mechanisms and genetic stabilities, their genomes were sequenced. Genomic comparisons with 9 other sequenced Ap strains revealed that their chromosomes were evolutionarily conserved, whereas the plasmids were unique compared with other Ap strains. Analysis of the acid-tolerant metabolic pathway at the genomic level indicated that the metabolism of some amino acids and the known mechanisms of acetic acid tolerance, might collaboratively contribute to acetic acid resistance in Ap strains. The balance of instability factors and stability factors in the genomes of Ap CICC 20001 and CGMCC 1.41 strains might be the basis for their genetic stability, consistent with their stable industrial performances. These observations provide important insights into the acid resistance mechanism and the genetic stability of Ap strains and lay a foundation for future genetic manipulation and engineering of these two strains.

Probiotic potential of noni juice fermented with lactic acid bacteria and bifidobacteria.

PubMed

Wang, Chung-Yi; Ng, Chang-Chai; Su, Hsuan; Tzeng, Wen-Sheng; Shyu, Yuan-Tay

2009-01-01

The present study assesses the feasibility of noni as a raw substrate for the production of probiotic noni juice by lactic acid bacteria (Lactobacilluscasei and Lactobacillus plantarum) and bifidobacteria (Bifidobacteriumlongum). Changes in pH, acidity, sugar content, cell survival and antioxidant properties during fermentation were monitored. All tested strains grew well on noni juice, reaching nearly 10⁹ colony-forming units/ml after 48 h fermentation. L.casei produced less lactic acid than B.longum and L. plantarum. After 4 weeks of cold storage at 4°C, B.longum and L. plantarum survived under low-pH conditions in fermented noni juice. In contrast, L.casei exhibited no cell viability after 3 weeks. Moreover, noni juice fermented with B.longum had a high antioxidant capacity that did not differ significantly (P <0.05) from that of lactic acid bacteria. Finally, we found that B.longum and L. plantarum are optimal probiotics for fermentation with noni juice.

Isolation of lactic acid bacteria from Malaysian foods and assessment of the isolates for industrial potential.

PubMed

Mohd Adnan, Ahmad Faris; Tan, Irene K P

2007-05-01

Two traditional fermented food 'tapai' (fermented tapioca) and 'tempoyak' (fermented durian flesh), chilli puree and fresh goat's milk were used as sources for the isolation of lactic acid bacteria (LAB). A total of 126 isolates were obtained and by sequential screening for catalase activity and Gram-staining, 55 were determined to be LAB out of which 16 were established to be homofermentative by the gel plug test. Seven isolates were identified by use of the API 50CHL kit and two lactobacilli strains and one lactococci strain were selected to study their growth and lactic acid production profiles in a time course experiment. The lactobacilli strains, both isolated from 'tapai', produced higher amounts of cells and lactic acid from glucose as compared to the lactococci strain isolated from fresh goat's milk.

Biochemical and molecular characterization of potential phosphate-solubilizing bacteria in acid sulfate soils and their beneficial effects on rice growth.

PubMed

Panhwar, Qurban Ali; Naher, Umme Aminun; Shamshuddin, Jusop; Jusop, Shamshuddin; Othman, Radziah; Latif, Md Abdul; Ismail, Mohd Razi

2014-01-01

A study was conducted to determine the total microbial population, the occurrence of growth promoting bacteria and their beneficial traits in acid sulfate soils. The mechanisms by which the bacteria enhance rice seedlings grown under high Al and low pH stress were investigated. Soils and rice root samples were randomly collected from four sites in the study area (Kelantan, Malaysia). The topsoil pH and exchangeable Al ranged from 3.3 to 4.7 and 1.24 to 4.25 cmol(c) kg(-1), respectively, which are considered unsuitable for rice production. Total bacterial and actinomycetes population in the acidic soils were found to be higher than fungal populations. A total of 21 phosphate-solubilizing bacteria (PSB) including 19 N2-fixing strains were isolated from the acid sulfate soil. Using 16S rRNA gene sequence analysis, three potential PSB strains based on their beneficial characteristics were identified (Burkholderia thailandensis, Sphingomonas pituitosa and Burkholderia seminalis). The isolated strains were capable of producing indoleacetic acid (IAA) and organic acids that were able to reduce Al availability via a chelation process. These PSB isolates solubilized P (43.65%) existing in the growth media within 72 hours of incubation. Seedling of rice variety, MR 219, grown at pH 4, and with different concentrations of Al (0, 50 and 100 µM) was inoculated with these PSB strains. Results showed that the bacteria increased the pH with a concomitant reduction in Al concentration, which translated into better rice growth. The improved root volume and seedling dry weight of the inoculated plants indicated the potential of these isolates to be used in a bio-fertilizer formulation for rice cultivation on acid sulfate soils.

Biochemical and Molecular Characterization of Potential Phosphate-Solubilizing Bacteria in Acid Sulfate Soils and Their Beneficial Effects on Rice Growth

PubMed Central

Panhwar, Qurban Ali; Naher, Umme Aminun; Jusop, Shamshuddin; Othman, Radziah; Latif, Md Abdul; Ismail, Mohd Razi

2014-01-01

A study was conducted to determine the total microbial population, the occurrence of growth promoting bacteria and their beneficial traits in acid sulfate soils. The mechanisms by which the bacteria enhance rice seedlings grown under high Al and low pH stress were investigated. Soils and rice root samples were randomly collected from four sites in the study area (Kelantan, Malaysia). The topsoil pH and exchangeable Al ranged from 3.3 to 4.7 and 1.24 to 4.25 cmolc kg−1, respectively, which are considered unsuitable for rice production. Total bacterial and actinomycetes population in the acidic soils were found to be higher than fungal populations. A total of 21 phosphate-solubilizing bacteria (PSB) including 19 N2-fixing strains were isolated from the acid sulfate soil. Using 16S rRNA gene sequence analysis, three potential PSB strains based on their beneficial characteristics were identified (Burkholderia thailandensis, Sphingomonas pituitosa and Burkholderia seminalis). The isolated strains were capable of producing indoleacetic acid (IAA) and organic acids that were able to reduce Al availability via a chelation process. These PSB isolates solubilized P (43.65%) existing in the growth media within 72 hours of incubation. Seedling of rice variety, MR 219, grown at pH 4, and with different concentrations of Al (0, 50 and 100 µM) was inoculated with these PSB strains. Results showed that the bacteria increased the pH with a concomitant reduction in Al concentration, which translated into better rice growth. The improved root volume and seedling dry weight of the inoculated plants indicated the potential of these isolates to be used in a bio-fertilizer formulation for rice cultivation on acid sulfate soils. PMID:25285745

Lactic acid bacteria in Hamei and Marcha of North East India.

PubMed

Tamang, J P; Dewan, S; Tamang, B; Rai, A; Schillinger, U; Holzapfel, W H

2007-06-01

Hamei and Marcha are mixed dough inocula used as starters for preparation of various indigenous alcoholic beverages in Manipur and Sikkim in India, respectively. These starters are traditionally prepared from rice with wild herbs and spices. Samples of Hamei and Marcha, collected from Manipur and Sikkim, respectively, were analysed for lactic acid bacterial composition. The population of lactic acid bacteria (LAB) was 6.9 and 7.1 Log cfu/g in Hamei and Marcha, respectively. On the basis of phenotypic and genotypic characters, LAB strains isolated from Hamei and Marcha were identified as Pediococcus pentosaceus, Lactobacillus plantarum and Lactobacillus brevis. Technological properties of LAB such as antimicrobial properties, effect on acidification, ability to produce biogenic amines and ethanol, degree of hydrophobicity and enzymatic activities were also performed. Pediococcus pentosaceus HS: B1, isolated from Hamei, was found to produce bacteriocin. None of the strains produced biogenic amines. LAB strains showed a strong acidifying ability and they also produced a wide spectrum of enzymes.

Survival and Growth of Probiotic Lactic Acid Bacteria in Refrigerated Pickle Products.

PubMed

Fan, Sicun; Breidt, Fred; Price, Robert; Pérez-Díaz, Ilenys

2017-01-01

We examined 10 lactic acid bacteria that have been previously characterized for commercial use as probiotic cultures, mostly for dairy products, including 1 Pediococcus and 9 Lactobacilli. Our objectives were to develop a rapid procedure for determining the long-term survivability of these cultures in acidified vegetable products and to identify suitable cultures for probiotic brined vegetable products. We therefore developed assays to measure acid resistance of these cultures to lactic and acetic acids, which are present in pickled vegetable products. We used relatively high acid concentrations (compared to commercial products) of 360 mM lactic acid and 420 mM acetic acid to determine acid resistance with a 1 h treatment. Growth rates were measured in a cucumber juice medium at pH 5.3, 4.2, and 3.8, at 30 °C and 0% to 2% NaCl. Significant differences in acid resistance and growth rates were found among the 10 cultures. In general, the acid resistant strains had slower growth rates than the acid sensitive strains. Based on the acid resistance data, selected cultures were tested for long-term survival in a simulated acidified refrigerated cucumber product. We found that one of the most acid resistant strains (Lactobacillus casei) could survive for up to 63 d at 4 °C without significant loss of viability at 10 8 CFU/mL. These data may aid in the development of commercial probiotic refrigerated pickle products. © 2016 Institute of Food Technologists®.

Cholesterol-Lowering Potentials of Lactic Acid Bacteria Based on Bile-Salt Hydrolase Activity and Effect of Potent Strains on Cholesterol Metabolism In Vitro and In Vivo

PubMed Central

Lin, Pei-Pei; Hsieh, You-Miin; Zhang, Zi-yi; Wu, Hui-Ching; Huang, Chun-Chih

2014-01-01

This study collected different probiotic isolates from animal and plant sources to evaluate the bile-salt hydrolase activity of probiotics in vitro. The deconjugation potential of bile acid was determined using high-performance liquid chromatography. HepG2 cells were cultured with probiotic strains with high BSH activity. The triglyceride (TG) and apolipoprotein B (apo B) secretion by HepG2 cells were evaluated. Our results show that the BSH activity and bile-acid deconjugation abilities of Pediococcus acidilactici NBHK002, Bifidobacterium adolescentis NBHK006, Lactobacillus rhamnosus NBHK007, and Lactobacillus acidophilus NBHK008 were higher than those of the other probiotic strains. The cholesterol concentration in cholesterol micelles was reduced within 24 h. NBHK007 reduced the TG secretion by 100% after 48 h of incubation. NBHK002, NBHK006, and NBHK007 could reduce apo B secretion by 33%, 38%, and 39%, respectively, after 24 h of incubation. The product PROBIO S-23 produced a greater decrease in the total concentration of cholesterol, low-density lipoprotein, TG, and thiobarbituric acid reactive substance in the serum or livers of hamsters with hypercholesterolemia compared with that of hamsters fed with a high-fat and high-cholesterol diet. These results show that the three probiotic strains of lactic acid bacteria are better candidates for reducing the risk of cardiovascular disease. PMID:25538960

Tyramine and phenylethylamine production among lactic acid bacteria isolated from wine.

PubMed

Landete, José María; Pardo, Isabel; Ferrer, Sergi

2007-04-20

The ability of wine lactic acid bacteria to produce tyramine and phenylethylamine was investigated by biochemical and genetic methods. An easy and accurate plate medium was developed to detect tyramine-producer strains, and a specific PCR assay that detects the presence of tdc gene was employed. All strains possessing the tdc gene were shown to produce tyramine and phenylethylamine. Wines containing high quantities of tyramine and phenylethylamine were found to contain Lactobacillus brevis or Lactobacillus hilgardii. The main tyramine producer was L. brevis. The ability to produce tyramine was absent or infrequent in the rest of the analysed wine species.

The depletion of sodium nitrite by lactic acid bacteria isolated from kimchi.

PubMed

Oh, Chang-Kyung; Oh, Myung-Chul; Kim, Soo-Hyun

2004-01-01

Nitrites, whether added or naturally occurring in foods, are potential carcinogens, and controlling their concentrations is important for maintaining a safe food supply. In this study we investigated the depletion of sodium nitrite (150 microg/mL) during the fermentation in Lactobacilli MRS broth at 5, 10, 15, 20, 25, 30, and 36 degrees C by lactic acid bacteria (LAB-A, -B, -C, and -D) isolated from kimchi and Leuconostoc mesenteroides strain KCTC3100. The four species of lactic acid bacteria isolated from kimchi were identified as L. mesenteroides, and all produced depletion of less than 20% of sodium nitrite after 10 days of incubation at 5 degrees C. There was less than 40% depletion after 9 days at 10 degrees C, 86.4-92.8% after 7 days at 15 degrees C, 81.4-87.8% after 4 days and more than 90.0% after 5 days at 20 degrees C, 76.3-85.7% after 3 days and more than 90.0% after 5 days at 25 degrees C, and more than 90.0% after 2 days at 30 and 36 degrees C. The depletion by LAB isolates was similar or higher than that by L. mesenteroides strain KCTC3100, and in particular, the LAB-D strain showed the highest depletion effect of all the strains tested, up to 15 degrees C. From these results, the strains isolated from kimchi were very effective for the depletion of sodium nitrite at high temperature, and all sodium nitrite was depleted at the initial period of incubation (1-2 days) at 30 and 36 degrees C. But as the temperature was lowered, the depletion effect of sodium nitrite was decreased in all the strains tested from kimchi. This illustrates that the depletion of nitrite by each strain is subject to the influence of temperatures.

Mannitol production by lactic acid bacteria grown in supplemented carob syrup.

PubMed

Carvalheiro, Florbela; Moniz, Patrícia; Duarte, Luís C; Esteves, M Paula; Gírio, Francisco M

2011-01-01

Detailed kinetic and physiological characterisation of eight mannitol-producing lactic acid bacteria, Leuconostoc citreum ATCC 49370, L. mesenteroides subsp. cremoris ATCC19254, L. mesenteroides subsp. dextranicum ATCC 19255, L. ficulneum NRRL B-23447, L. fructosum NRRL B-2041, L. lactis ATCC 19256, Lactobacillus intermedius NRRL 3692 and Lb. reuteri DSM 20016, was performed using a carob-based culture medium, to evaluate their different metabolic capabilities. Cultures were thoroughly followed for 30 h to evaluate consumption of sugars, as well as production of biomass and metabolites. All strains produced mannitol at high yields (>0.70 g mannitol/g fructose) and volumetric productivities (>1.31 g/l h), and consumed fructose and glucose simultaneously, but fructose assimilation rate was always higher. The results obtained enable the studied strains to be divided mainly into two groups: one for which glucose assimilation rates were below 0.78 g/l h (strains ATCC 49370, ATCC 19256 and ATCC 19254) and the other for which they ranged between 1.41 and 1.89 g/l h (strains NRRL B-3692, NRRL B-2041, NRRL B-23447 and DSM 20016). These groups also exhibited different mannitol production rates and yields, being higher for the strains with faster glucose assimilation. Besides mannitol, all strains also produced lactic acid and acetic acid. The best performance was obtained for L. fructosum NRRL B-2041, with maximum volumetric productivity of 2.36 g/l h and the highest yield, stoichiometric conversion of fructose to mannitol.

Identification of lactic acid bacteria from chili bo, a Malaysian food ingredient.

PubMed

Leisner, J J; Pot, B; Christensen, H; Rusul, G; Olsen, J E; Wee, B W; Muhamad, K; Ghazali, H M

1999-02-01

Ninety-two strains of lactic acid bacteria (LAB) were isolated from a Malaysian food ingredient, chili bo, stored for up to 25 days at 28 degreesC with no benzoic acid (product A) or with 7,000 mg of benzoic acid kg-1 (product B). The strains were divided into eight groups by traditional phenotypic tests. A total of 43 strains were selected for comparison of their sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) whole-cell protein patterns with a SDS-PAGE database of LAB. Isolates from product A were identified as Lactobacillus plantarum, Lactobacillus fermentum, Lactobacillus farciminis, Pediococcus acidilactici, Enterococcus faecalis, and Weissella confusa. Five strains belonging to clusters which could not be allocated to existing species by SDS-PAGE were further identified by 16S rRNA sequence comparison. One strain was distantly related to the Lactobacillus casei/Pediococcus group. Two strains were related to Weissella at the genus or species level. Two other strains did not belong to any previously described 16S rRNA group of LAB and occupied an intermediate position between the L. casei/Pediococcus group and the Weissella group and species of Carnobacterium. The latter two strains belong to the cluster of LAB that predominated in product B. The incidence of new species and subspecies of LAB in chili bo indicate the high probability of isolation of new LAB from certain Southeast Asian foods. None of the isolates exhibited bacteriocin activity against L. plantarum ATCC 14917 and LMG 17682.

Characterization of Lactic Acid Bacteria (LAB) isolated from Indonesian shrimp paste (terasi)

NASA Astrophysics Data System (ADS)

Amalia, U.; Sumardianto; Agustini, T. W.

2018-02-01

Shrimp paste was one of fermented products, popular as a taste enhancer in many dishes. The processing of shrimp paste was natural fermentation, depends on shrimp it self and the presence of salt. The salt inhibits the growth of undesirable microorganism and allows the salt-tolerant lactic acid bacteria (LAB) to ferment the protein source to lactic acids. The objectives of this study were to characterize LAB isolated from Indonesian shrimp paste or "Terasi" with different times of fermentation (30, 60 and 90 days). Vitech analysis showed that there were four strains of the microorganism referred to as lactic acid bacteria (named: LABS1, LABS2, LABS3 and LABS4) with 95% sequence similarity. On the basis of biochemical, four isolates represented Lactobacillus, which the name Lactobacillus plantarum is proposed. L.plantarum was play role in resulting secondary metabolites, which gave umami flavor in shrimp paste.

In Situ Production of Exopolysaccharides during Sourdough Fermentation by Cereal and Intestinal Isolates of Lactic Acid Bacteria

PubMed Central

Tieking, Markus; Korakli, Maher; Ehrmann, Matthias A.; Gänzle, Michael G.; Vogel, Rudi F.

2003-01-01

EPS formed by lactobacilli in situ during sourdough fermentation may replace hydrocolloids currently used as texturizing, antistaling, or prebiotic additives in bread production. In this study, a screening of >100 strains of cereal-associated and intestinal lactic acid bacteria was performed for the production of exopolysaccharides (EPS) from sucrose. Fifteen strains produced fructan, and four strains produced glucan. It was remarkable that formation of glucan and fructan was most frequently found in intestinal isolates and strains of the species Lactobacillus reuteri, Lactobacillus pontis, and Lactobacillus frumenti from type II sourdoughs. By the use of PCR primers derived from conserved amino acid sequences of bacterial levansucrase genes, it was shown that 6 of the 15 fructan-producing lactobacilli and none of 20 glucan producers or EPS-negative strains carried a levansucrase gene. In sourdough fermentations, it was determined whether those strains producing EPS in MRS medium modified as described by Stolz et al. (37) and containing 100 g of sucrose liter−1 as the sole source of carbon also produce the same EPS from sucrose during sourdough fermentation in the presence of 12% sucrose. For all six EPS-producing strains evaluated in sourdough fermentations, in situ production of EPS at levels ranging from 0.5 to 2 g/kg of flour was demonstrated. Production of EPS from sucrose is a metabolic activity that is widespread among sourdough lactic acid bacteria. Thus, the use of these organisms in bread production may allow the replacement of additives. PMID:12571016

Tannic acid degradation by Klebsiella strains isolated from goat feces

PubMed Central

Tahmourespour, Arezoo; Tabatabaee, Nooroldin; Khalkhali, Hossein; Amini, Imane

2016-01-01

Background and Objectives: Tannins are toxic polyphenols that either bind and precipitate or condense proteins. The high tannin content of some plants is the preliminary limitation of using them as a ruminant feed. So, the aim of this study was the isolation and characterization of tannic acid degrading bacterial strains from goat feces before and after feeding on Pistachio-Soft Hulls as tannin rich diet (TRD). Materials and Methods: Bacterial strains capable of utilizing tannic acid as sole carbon and energy source were isolated and characterized from goat feces before and after feeding on TRD. Tannase activity, maximum tolerable concentration and biodegradation potential were assessed. Results: Four tannase positive isolates were identified as Klebsiella pneumoniae. Isolated strains showed the maximum tolerable concentration of 64g/L of tannin. The tannic acid degradation percentage at a concentration of 15.0 g/L reached a maximum of 68% after 24 h incubation, and more than 98% after 72 h incubation. The pH of the medium also decreased along with tannic acid utilization. Conclusions: It is obvious that TRD induced adaptive responses. Thus, while the bacteria were able to degrade and detoxify the tannic acids, they had to adapt in the presence of high concentrations of tannic acid. So, these isolates have an amazing potential for application in bioremediation, waste water treatment, also reduction of tannins antinutritional effects in animal feeds. PMID:27092220

Global insights into acetic acid resistance mechanisms and genetic stability of Acetobacter pasteurianus strains by comparative genomics

PubMed Central

Wang, Bin; Shao, Yanchun; Chen, Tao; Chen, Wanping; Chen, Fusheng

2015-01-01

Acetobacter pasteurianus (Ap) CICC 20001 and CGMCC 1.41 are two acetic acid bacteria strains that, because of their strong abilities to produce and tolerate high concentrations of acetic acid, have been widely used to brew vinegar in China. To globally understand the fermentation characteristics, acid-tolerant mechanisms and genetic stabilities, their genomes were sequenced. Genomic comparisons with 9 other sequenced Ap strains revealed that their chromosomes were evolutionarily conserved, whereas the plasmids were unique compared with other Ap strains. Analysis of the acid-tolerant metabolic pathway at the genomic level indicated that the metabolism of some amino acids and the known mechanisms of acetic acid tolerance, might collaboratively contribute to acetic acid resistance in Ap strains. The balance of instability factors and stability factors in the genomes of Ap CICC 20001 and CGMCC 1.41 strains might be the basis for their genetic stability, consistent with their stable industrial performances. These observations provide important insights into the acid resistance mechanism and the genetic stability of Ap strains and lay a foundation for future genetic manipulation and engineering of these two strains. PMID:26691589

Use of hydrolysates from Atlantic cod (Gadus morhua L.) viscera as a complex nitrogen source for lactic acid bacteria.

PubMed

Aspmo, Stein Ivar; Horn, Svein Jarle; Eijsink, Vincent G H

2005-07-01

Hydrolysates of cod viscera were tested as an alternative to commonly used complex nitrogen sources (peptones and/or extracts) for the type strains of the lactic acid bacteria Lactococcus lactis, Lactobacillus acidophilus, Lactobacillus helveticus, Lactobacillus casei, Lactobacillus sakei and Pediococcus pentosaceus. Comparative studies with MRS-like media containing different nitrogen sources showed that all the fish hydrolysates performed equally well or better than commercial extracts/peptones for all selected lactic acid bacteria.

Production of Succinic Acid from Citric Acid and Related Acids by Lactobacillus Strains

PubMed Central

Kaneuchi, Choji; Seki, Masako; Komagata, Kazuo

1988-01-01

A number of Lactobacillus strains produced succinic acid in de Man-Rogosa-Sharpe broth to various extents. Among 86 fresh isolates from fermented cane molasses in Thailand, 30 strains (35%) produced succinic acid; namely, 23 of 39 Lactobacillus reuteri strains, 6 of 18 L. cellobiosus strains, and 1 of 6 unidentified strains. All of 10 L. casei subsp. casei strains, 5 L. casei subsp. rhamnosus strains, 6 L. mali strains, and 2 L. buchneri strains did not produce succinic acid. Among 58 known strains including 48 type strains of different Lactobacillus species, the strains of L. acidophilus, L. crispatus, L. jensenii, and L. parvus produced succinic acid to the same extent as the most active fresh isolates, and those of L. alimentarius, L. collinoides, L. farciminis, L. fructivorans (1 of 2 strains tested), L. malefermentans, and L. reuteri were also positive, to lesser extents. Diammonium citrate in de Man-Rogosa-Sharpe broth was determined as a precursor of the succinic acid produced. Production rates were about 70% on a molar basis with two fresh strains tested. Succinic acid was also produced from fumaric and malic acids but not from dl-isocitric, α-ketoglutaric, and pyruvic acids. The present study is considered to provide the first evidence on the production of succinic acid, an important flavoring substance in dairy products and fermented beverages, from citrate by lactobacilli. PMID:16347795

Production of succinic Acid from citric Acid and related acids by lactobacillus strains.

PubMed

Kaneuchi, C; Seki, M; Komagata, K

1988-12-01

A number of Lactobacillus strains produced succinic acid in de Man-Rogosa-Sharpe broth to various extents. Among 86 fresh isolates from fermented cane molasses in Thailand, 30 strains (35%) produced succinic acid; namely, 23 of 39 Lactobacillus reuteri strains, 6 of 18 L. cellobiosus strains, and 1 of 6 unidentified strains. All of 10 L. casei subsp. casei strains, 5 L. casei subsp. rhamnosus strains, 6 L. mali strains, and 2 L. buchneri strains did not produce succinic acid. Among 58 known strains including 48 type strains of different Lactobacillus species, the strains of L. acidophilus, L. crispatus, L. jensenii, and L. parvus produced succinic acid to the same extent as the most active fresh isolates, and those of L. alimentarius, L. collinoides, L. farciminis, L. fructivorans (1 of 2 strains tested), L. malefermentans, and L. reuteri were also positive, to lesser extents. Diammonium citrate in de Man-Rogosa-Sharpe broth was determined as a precursor of the succinic acid produced. Production rates were about 70% on a molar basis with two fresh strains tested. Succinic acid was also produced from fumaric and malic acids but not from dl-isocitric, alpha-ketoglutaric, and pyruvic acids. The present study is considered to provide the first evidence on the production of succinic acid, an important flavoring substance in dairy products and fermented beverages, from citrate by lactobacilli.

Antifungal activity of strains of lactic acid bacteria isolated from a semolina ecosystem against Penicillium roqueforti, Aspergillus niger and Endomyces fibuliger contaminating bakery products.

PubMed

Valerio, Francesca; Favilla, Mara; De Bellis, Palmira; Sisto, Angelo; de Candia, Silvia; Lavermicocca, Paola

2009-09-01

Thirty samples of Italian durum wheat semolina and whole durum wheat semolina, generally used for the production of Southern Italy's traditional breads, were subjected to microbiological analysis in order to explore their lactic acid bacteria (LAB) diversity and to find strains with antifungal activity. A total of 125 presumptive LAB isolates (Gram-positive and catalase-negative) were characterized by repetitive extragenic palindromic-PCR (REP-PCR) and sequence analysis of the 16S rRNA gene, leading to the identification of the following species: Weissella confusa, Weissella cibaria, Leuconostoc citreum, Leuconostoc mesenteroides, Lactococcus lactis, Lactobacillus rossiae and Lactobacillus plantarum. The REP-PCR results delineated 17 different patterns whose cluster analysis clearly differentiated W. cibaria from W. confusa isolates. Seventeen strains, each characterized by a different REP-PCR pattern, were screened for their antifungal properties. They were grown in a flour-based medium, comparable to a real food system, and the resulting fermentation products (FPs) were tested against fungal species generally contaminating bakery products, Aspergillus niger, Penicillium roqueforti and Endomyces fibuliger. The results of the study indicated a strong inhibitory activity - comparable to that obtained with the common preservative calcium propionate (0.3% w/v) - of ten LAB strains against the most widespread contaminant of bakery products, P. roqueforti. The screening also highlighted the unexplored antifungal activity of L. citreum, L. rossiae and W. cibaria (1 strain), which inhibited all fungal strains to the same or a higher extent compared with calcium propionate. The fermentation products of these three strains were characterized by low pH values, and a high content of lactic and acetic acids.

Identification of TLR2/TLR6 signalling lactic acid bacteria for supporting immune regulation.

PubMed

Ren, Chengcheng; Zhang, Qiuxiang; de Haan, Bart J; Zhang, Hao; Faas, Marijke M; de Vos, Paul

2016-10-06

Although many lactic acid bacteria (LAB) influence the consumer's immune status it is not completely understood how this is established. Bacteria-host interactions between bacterial cell-wall components and toll-like receptors (TLRs) have been suggested to play an essential role. Here we investigated the interaction between LABs with reported health effects and TLRs. By using cell-lines expressing single or combination of TLRs, we show that LABs can signal via TLR-dependent and independent pathways. The strains only stimulated and did not inhibit TLRs. We found that several strains such as L. plantarum CCFM634, L. plantarum CCFM734, L. fermentum CCFM381, L. acidophilus CCFM137, and S. thermophilus CCFM218 stimulated TLR2/TLR6. TLR2/TLR6 is essential in immune regulatory processes and of interest for prevention of diseases. Specificity of the TLR2/TLR6 stimulation was confirmed with blocking antibodies. Immunomodulatory properties of LABs were also studied by assessing IL-10 and IL-6 secretion patterns in bacteria-stimulated THP1-derived macrophages, which confirmed species and strain specific effects of the LABs. With this study we provide novel insight in LAB specific host-microbe interactions. Our data demonstrates that interactions between pattern recognition receptors such as TLRs is species and strain specific and underpins the importance of selecting specific strains for promoting specific health effects.

Identification of Lactic Acid Bacteria from Chili Bo, a Malaysian Food Ingredient

PubMed Central

Leisner, Jørgen J.; Pot, Bruno; Christensen, Henrik; Rusul, Gulam; Olsen, John E.; Wee, Bee Wah; Muhamad, Kharidah; Ghazali, Hasanah M.

1999-01-01

Ninety-two strains of lactic acid bacteria (LAB) were isolated from a Malaysian food ingredient, chili bo, stored for up to 25 days at 28°C with no benzoic acid (product A) or with 7,000 mg of benzoic acid kg−1 (product B). The strains were divided into eight groups by traditional phenotypic tests. A total of 43 strains were selected for comparison of their sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) whole-cell protein patterns with a SDS-PAGE database of LAB. Isolates from product A were identified as Lactobacillus plantarum, Lactobacillus fermentum, Lactobacillus farciminis, Pediococcus acidilactici, Enterococcus faecalis, and Weissella confusa. Five strains belonging to clusters which could not be allocated to existing species by SDS-PAGE were further identified by 16S rRNA sequence comparison. One strain was distantly related to the Lactobacillus casei/Pediococcus group. Two strains were related to Weissella at the genus or species level. Two other strains did not belong to any previously described 16S rRNA group of LAB and occupied an intermediate position between the L. casei/Pediococcus group and the Weissella group and species of Carnobacterium. The latter two strains belong to the cluster of LAB that predominated in product B. The incidence of new species and subspecies of LAB in chili bo indicate the high probability of isolation of new LAB from certain Southeast Asian foods. None of the isolates exhibited bacteriocin activity against L. plantarum ATCC 14917 and LMG 17682. PMID:9925588

Selection of enhanced antimicrobial activity posing lactic acid bacteria characterised by (GTG)5-PCR fingerprinting.

PubMed

Šalomskienė, Joana; Abraitienė, Asta; Jonkuvienė, Dovilė; Mačionienė, Irena; Repečkienė, Jūratė

2015-07-01

The aim of the study was a detail evaluation of genetic diversity among the lactic acid bacteria (LAB) strains having an advantage of a starter culture in order to select genotypically diverse strains with enhanced antimicrobial effect on some harmfull and pathogenic microorganisms. Antimicrobial activity of LAB was performed by the agar well diffusion method and was examined against the reference strains and foodborne isolates of Bacillus cereus, Listeria monocytogenes, Escherichia coli, Staphylococcus aureus and Salmonella Typhimurium. Antifungal activity was tested against the foodborne isolates of Candida parapsilosis, Debaromyces hansenii, Kluyveromyces marxianus, Pichia guilliermondii, Yarowia lipolytica, Aspergillus brasiliensis, Aspergillus versicolor, Cladosporium herbarum, Penicillium chrysogenum and Scopulariopsis brevicaulis. A total 40 LAB strains representing Lactobacillus (23 strains), Lactococcus (13 strains) and Streptococcus spp. (4 strains) were characterised by repetitive sequence based polymerase chain reaction fingerprinting which generated highly discriminatory profiles, confirmed the identity and revealed high genotypic heterogeneity among the strains. Many of tested LAB demonstrated strong antimicrobial activity specialised against one or few indicator strains. Twelve LAB strains were superior in suppressing growth of the whole complex of pathogenic bacteria and fungi. These results demonstrated that separate taxonomic units offered different possibilities of selection for novel LAB strains could be used as starter cultures enhancing food preservation.

Human antigen-presenting cells respond differently to gut-derived probiotic bacteria but mediate similar strain-dependent NK and T cell activation.

PubMed

Fink, Lisbeth N; Zeuthen, Louise H; Ferlazzo, Guido; Frøkiaer, Hanne

2007-12-01

The intestinal microbiota is essential for homeostasis of the local and systemic immune system, and particularly strains of lactic acid bacteria and Escherichia coli have been shown to have balancing effects on inflammatory conditions such as allergy and inflammatory bowel disease. However, in vitro assessment of the immunomodulatory effects of distinct strains may depend strongly on the cell type used as a model. To select the most appropriate model for screening of beneficial bacteria in human cells, the response to strains of intestinal bacteria of three types of antigen-presenting cells (APC) was compared; blood myeloid dendritic cells (DC), monocyte-derived DC and monocytes, and the effector response of natural killer cells and naïve T cells was characterized. Maturation induced by gut-derived bacteria differed between APC, with blood DC and monocytes responding with the production of IL-6 and tumour necrosis factor-alpha to bacteria, which elicited mainly IL-10 in monocyte-derived DC. In contrast, comparable IFN-gamma production patterns were found in both natural killer cells and T cells induced by all bacteria-matured APC. An inhibitory effect of certain strains on this IFN-gamma production was also mediated by all types of APC. The most potent responses were induced by monocyte-derived DC, which thus constitute a sensitive screening model.

The effect of lactic acid bacteria on cocoa bean fermentation.

PubMed

Ho, Van Thi Thuy; Zhao, Jian; Fleet, Graham

2015-07-16

Cocoa beans (Theobroma cacao L.) are the raw material for chocolate production. Fermentation of cocoa pulp by microorganisms is crucial for developing chocolate flavor precursors. Yeasts conduct an alcoholic fermentation within the bean pulp that is essential for the production of good quality beans, giving typical chocolate characters. However, the roles of bacteria such as lactic acid bacteria and acetic acid bacteria in contributing to the quality of cocoa bean and chocolate are not fully understood. Using controlled laboratory fermentations, this study investigated the contribution of lactic acid bacteria to cocoa bean fermentation. Cocoa beans were fermented under conditions where the growth of lactic acid bacteria was restricted by the use of nisin and lysozyme. The resultant microbial ecology, chemistry and chocolate quality of beans from these fermentations were compared with those of indigenous (control) fermentations. The yeasts Hanseniaspora guilliermondii, Pichia kudriavzevii, Kluyveromyces marxianus and Saccharomyces cerevisiae, the lactic acid bacteria Lactobacillus plantarum, Lactobacillus pentosus and Lactobacillus fermentum and the acetic acid bacteria Acetobacter pasteurianus and Gluconobacter frateurii were the major species found in control fermentations. In fermentations with the presence of nisin and lysozyme, the same species of yeasts and acetic acid bacteria grew but the growth of lactic acid bacteria was prevented or restricted. These beans underwent characteristic alcoholic fermentation where the utilization of sugars and the production of ethanol, organic acids and volatile compounds in the bean pulp and nibs were similar for beans fermented in the presence of lactic acid bacteria. Lactic acid was produced during both fermentations but more so when lactic acid bacteria grew. Beans fermented in the presence or absence of lactic acid bacteria were fully fermented, had similar shell weights and gave acceptable chocolates with no differences

Antibacterial Activity of Lactic Acid Bacteria Isolated from Gastrointestinal Tract of “Ayam Kampung” Chicken Against Food Pathogens

NASA Astrophysics Data System (ADS)

Nur Jannah, Siti; Rini Saraswati, Tyas; Handayani, Dwi; Pujiyanto, Sri

2018-05-01

Food borne disease results from ingestion of water and wide variety of food contaminated with pathogenic organisms. The main causes of food borne diseases are bacteria, such as Escherichia coli and Staphylococcus aureus. The objective of this study was to determine antimicrobial activity of lactic acid bacteria (LAB) isolated from local chicken gastrointestinal tract with an emphasis on their probiotic properties. The colonies of bacteria that producing clear zone on MRSA plus 0.5% CaCO3, Gram-positive and catalase-negative were isolated as lactic acid bacteria. Some of the strains (10 isolates) were tested for their ability to inhibit growth of Escherichia coli and Staphylococcus aureus, and for acid pH and bile salt tolerance. The results showed that the all selected isolates producing antimicrobial compounds inhibits the growth of Escherichia coli and Staphylococcus aureus, both in the supernatant and supernatant plus 2M NaOH, and still growing in medium condition with pH 2.0 and 0.1% bile salt. It revealing the potential use of the lactic acid bacteria from chicken gastrointestinal tract for probiotics in food.

Phage-Encoded Colanic Acid-Degrading Enzyme Permits Lytic Phage Infection of a Capsule-Forming Resistant Mutant Escherichia coli Strain

PubMed Central

Kim, Min Soo; Kim, Young Deuk; Hong, Sung Sik; Park, Kwangseo; Ko, Kwan Soo

2014-01-01

In this study, we isolated a bacteriophage T7-resistant mutant strain of Escherichia coli (named S3) and then proceeded to characterize it. The mutant bacterial colonies appeared to be mucoid. Microarray analysis revealed that genes related to colanic acid production were upregulated in the mutant. Increases in colanic acid production by the mutant bacteria were observed when l-fucose was measured biochemically, and protective capsule formation was observed under an electron microscope. We found a point mutation in the lon gene promoter in S3, the mutant bacterium. Overproduction of colanic acid was observed in some phage-resistant mutant bacteria after infection with other bacteriophages, T4 and lambda. Colanic acid overproduction was also observed in clinical isolates of E. coli upon phage infection. The overproduction of colanic acid resulted in the inhibition of bacteriophage adsorption to the host. Biofilm formation initially decreased shortly after infection but eventually increased after 48 h of incubation due to the emergence of the mutant bacteria. Bacteriophage PBECO4 was shown to infect the colanic acid-overproducing mutant strains of E. coli. We confirmed that the gene product of open reading frame 547 (ORF547) of PBECO4 harbored colanic acid-degrading enzymatic (CAE) activity. Treatment of the T7-resistant bacteria with both T7 and PBECO4 or its purified enzyme (CAE) led to successful T7 infection. Biofilm formation decreased with the mixed infection, too. This procedure, using a phage cocktail different from those exploiting solely receptor differences, represents a novel strategy for overcoming phage resistance in mutant bacteria. PMID:25416767

Rope-producing strains of Bacillus spp. from wheat bread and strategy for their control by lactic acid bacteria.

PubMed

Pepe, Olimpia; Blaiotta, Giuseppe; Moschetti, Giancarlo; Greco, Teresa; Villani, Francesco

2003-04-01

Two types of white wheat bread (high- and low-type loaves) were investigated for rope spoilage. Thirty of the 56 breads tested developed rope spoilage within 5 days; the high-type loaves were affected by rope spoilage more than the low-type loaves. Sixty-one Bacillus strains were isolated from ropy breads and were characterized on the basis of their phenotypic and genotypic traits. All of the isolates were identified as Bacillus subtilis by biochemical tests, but molecular assays (randomly amplified polymorphic DNA PCR assay, denaturing gradient gel electrophoresis analysis, and sequencing of the V3 region of 16S ribosomal DNA) revealed greater Bacillus species variety in ropy breads. In fact, besides strains of B. subtilis, Bacillus licheniformis, Bacillus cereus, and isolates of Bacillus clausii and Bacillus firmus were also identified. All of the ropy Bacillus isolates exhibited amylase activity, whereas only 32.4% of these isolates were able to produce ropiness in bread slices after treatment at 96 degrees C for 10 min. Strains of lactic acid bacteria previously isolated from sourdough were first selected for antirope activity on bread slices and then used as starters for bread-making experiments. Prevention of growth of approximately 10(4) rope-producing B. subtilis G1 spores per cm(2) on bread slices for more than 15 days was observed when heat-treated cultures of Lactobacillus plantarum E5 and Leuconostoc mesenteroides A27 were added. Growth of B. subtilis G1 occurred after 7 days in breads started with Saccharomyces cerevisiae T22, L. plantarum E5, and L. mesenteroides A27.

Survival of lactic acid bacteria from fermented milks in an in vitro digestion model exploiting sequential incubation in human gastric and duodenum juice.

PubMed

Faye, T; Tamburello, A; Vegarud, G E; Skeie, S

2012-02-01

In the present study, the survival of 9 lactic acid bacteria (5 Lactococcus strains, 3 Lactobacillus strains, and 1 strain of Enterococcus hirae), was investigated in vitro under conditions similar to human digestion using human gastric and duodenal juices. The tolerance of the bacteria was also tested with traditional methods using acidic conditions and bile salts. The strains were subjected to a model digestive system comprising sequential incubation in human gastric and duodenal juices, in a 2-step digestion assay at 37°C, simulating the human upper gastrointestinal tract with human gastric juices at pH 2.5 and human duodenal juices at pH 7. The bacterial strains were tested either as washed cells from culture media or in fermented milk. The initial in vitro testing in acid and bile salts showed that Lactobacillus strains and the E. hirae strain displayed a significantly higher acid tolerance than the lactococci. The lactobacilli and the Enterococcus numbers increased, whereas the lactococci decreased at least 1 log during the bile salt treatment. The Lactobacillus strains showed the highest survival rate in the model digestive system when washed bacterial cultures were used with a minor log reduction, whereas the lactococci numbers were reduced by at least log 4. However, when using fermented milks in the model digestion system it was demonstrated that the Enterococcus strain and 2 strains of Lactococcus lactis ssp. cremoris benefited significantly from the presence of the fermented milk as food matrix, with log numbers >log 7 and 5, respectively, after digestion of the fermented milk. The analyses reported comprise a comprehensive in vitro testing regimen suitable for evaluation of the survival of candidate probiotic bacteria in human digestion as an initial prescreen to clinical trials. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Characterisation of lactic acid bacteria isolated from naturally fermented Greek dry salami.

PubMed

Samelis, J; Maurogenakis, F; Metaxopoulos, J

1994-10-01

A total of 348 lactic acid bacteria isolated from five batches of naturally fermented dry salami at various stages of ripening were characterised. The majority of the strains were assigned to two main phylogenetic groups of species: (i) the psychrotrophic, formerly called atypical, meat streptobacteria (169 strains) and (ii) a new genus Weissella (120), which was recently proposed (Collins et al., 1993) to include Leuconostoc paramesenteroides and some other closely related species. Meat streptobacteria were identified as Lactobacillus curvatus (88 strains) and L. sake (76), whereas 5 strains were indistinguishable and, thus designated L. sake/curvatus. Non-psychrotrophic streptobacteria were also isolated and identified as L. plantarum (34 strains), L. farciminis (10), L. coryniformis (1) and L. casei subsp. pseudoplantarum (1). The majority of the Weissella strains (86) were leuconostoc-like bacteria; four of them were identified as W. viridescens, 11 belonged to the newly described W. hellenica (Collins et al., 1993), another 11 resembled W. paramesenteroides, whereas 60 isolates were not classified to any species. The latter group comprised strains that produced D(L)-lactate. The remaining Weissella were gas-forming, arginine-positive rods assigned to W. minor (31) and W. halotolerans (3). Other species identified were Enterococcus faecium (10), Leuconostoc mesenteroides (1), L. brevis (1) and Pediococcus sp. (1). The main criteria used to distinguish between above species as well as their distribution on the five salami batches in relation to their succession with time and suitability as starters were discussed.

Characterisation and biochemical properties of predominant lactic acid bacteria from fermenting cassava for selection as starter cultures.

PubMed

Kostinek, M; Specht, I; Edward, V A; Pinto, C; Egounlety, M; Sossa, C; Mbugua, S; Dortu, C; Thonart, P; Taljaard, L; Mengu, M; Franz, C M A P; Holzapfel, W H

2007-03-20

A total of 375 lactic acid bacteria were isolated from fermenting cassava in South Africa, Benin, Kenya and Germany, and were characterised by phenotypic and genotypic tests. These could be divided into five main groups comprising strains of facultatively heterofermentative rods, obligately heterofermentative rods, heterofermentative cocci, homofermentative cocci and obligately homofermentative rods, in decreasing order of predominance. Most of the facultatively heterofermentative rods were identified by phenotypic tests as presumptive Lactobacillus plantarum-group strains, which also comprised the most predominant bacteria (54.4% of strains) isolated in the study. The next predominant group of lactic acid bacteria (14.1% of total isolates) consisted of obligately heterofermentative rods belonging either to the genus Lactobacillus or Weissella, followed by the heterofermentative cocci (13.9% of isolates) belonging to the genera Weissella or Leuconostoc. Homofermentative cocci were also isolated (13.3% of isolates). Biochemical properties such as production of alpha-amylase, beta-glucosidase, tannase, antimicrobials (presumptive bacteriocin and H(2)O(2)-production), acidification and fermentation of the indigestible sugars raffinose and stachyose, were evaluated in vitro for selection of potential starter strains. A total of 32 strains with one or more desirable biochemical properties were pre-selected and identified using rep-PCR fingerprinting in combination with 16S rRNA sequencing of representative rep-PCR cluster isolates. Of these strains, 18 were identified as L. plantarum, four as Lactobacillus pentosus, two each as Leuconostoc fallax, Weissella paramesenteroides and Lactobacillus fermentum, one each as Leuconostoc mesenteroides subsp. mesenteroides and Weissella cibaria, while two remained unidentified but could be assigned to the L. plantarum-group. These strains were further investigated for clonal relationships, using RAPD-PCR with three primers, and of

2,4-Dichlorophenoxyacetic acid-degrading bacteria contain mosaics of catabolic genes.

PubMed Central

Fulthorpe, R R; McGowan, C; Maltseva, O V; Holben, W E; Tiedje, J M

1995-01-01

DNA from 32 2,4-dichlorophenoxyacetic acid (2,4-D)-degrading bacteria from diverse locations was probed with the first three genes of the well-known 2,4-D degradation pathway found in Alcaligenes eutrophus JMP134(pJP4). The majority of strains did not show high levels of homology to the first three genes of the 2,4-D degradation pathway, tfdA, -B, and -C. Most strains showed combinations of tfdA-, B-, and C-like elements that exhibited various degrees of homology to the gene probes. Strains having the same genomic fingerprints (as determined by repetitive extragenic palindromic PCR) exhibited the same hybridization pattern regardless of the geographic origin of the strain, with the exception of a strain isolated from Puerto Rico. This strain had the same genomic fingerprint as that of numerous other strains in the collection but differed in its hybridization against the tfdA gene probe. Members of the beta subdivision of the Proteobacteria class, specifically Alcaligenes, Burkholderia, and Rhodoferax species, carried DNA fragments with 60% or more sequence similarity to tfdA of pJP4, and most carried fragments showing at least 60% homology to tfdB. However, many strains did not hybridize with tfdC, although they exhibited chlorocatechol dioxygenase activity. Members of the alpha subdivision of the Proteobacteria class, mostly of the genus Sphingomonas, did not hybridize to either tfdA or tfdC, but some hybridized at low stringency to tfdB. The data suggest that extensive interspecies transfer of a variety of homologous degradative genes has been involved in the evolution of 2,4-D-degrading bacteria. PMID:7574638

Hydrolytic breakdown of lactoferricin by lactic acid bacteria.

PubMed

Paul, Moushumi; Somkuti, George A

2010-02-01

Lactoferricin is a 25-amino acid antimicrobial peptide fragment that is liberated by pepsin digestion of lactoferrin present in bovine milk. Along with its antibacterial properties, lactoferricin has also been reported to have immunostimulatory, antiviral, and anticarcinogenic effects. These attributes provide lactoferricin and other natural bioactive peptides with the potential to be functional food ingredients that can be used by the food industry in a variety of applications. At present, commercial uses of these types of compounds are limited by the scarcity of information on their ability to survive food processing environments. We have monitored the degradation of lactoferricin during its incubation with two types of lactic acid bacteria used in the yogurt-making industry, Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus, with the aim of assessing the stability of this milk protein-derived peptide under simulated yogurt-making conditions. Analysis of the hydrolysis products isolated from these experiments indicates degradation of this peptide near neutral pH by lactic acid bacteria-associated peptidases, the extent of which was influenced by the bacterial strain used. However, the data also showed that compared to other milk-derived bioactive peptides that undergo complete degradation under these conditions, the 25-amino acid lactoferricin is apparently more resistant, with approximately 50% of the starting material remaining after 4 h of incubation. These findings imply that lactoferricin, as a natural milk protein-derived peptide, has potential applications in the commercial production of yogurt-like fermented dairy products as a multi-functional food ingredient.

Differential staining of bacteria: acid fast stain.

PubMed

Reynolds, Jackie; Moyes, Rita B; Breakwell, Donald P

2009-11-01

Acid-fastness is an uncommon characteristic shared by the genera Mycobacterium (Section 10A) and Nocardia. Because of this feature, this stain is extremely helpful in identification of these bacteria. Although Gram positive, acid-fast bacteria do not take the crystal violet into the wall well, appearing very light purple rather than the deep purple of normal Gram-positive bacteria. (c) 2009 by John Wiley & Sons, Inc.

Animal Rennets as Sources of Dairy Lactic Acid Bacteria

PubMed Central

Cruciata, Margherita; Sannino, Ciro; Ercolini, Danilo; Scatassa, Maria L.; De Filippis, Francesca; Mancuso, Isabella; La Storia, Antonietta; Moschetti, Giancarlo

2014-01-01

The microbial composition of artisan and industrial animal rennet pastes was studied by using both culture-dependent and -independent approaches. Pyrosequencing targeting the 16S rRNA gene allowed to identify 361 operational taxonomic units (OTUs) to the genus/species level. Among lactic acid bacteria (LAB), Streptococcus thermophilus and some lactobacilli, mainly Lactobacillus crispatus and Lactobacillus reuteri, were the most abundant species, with differences among the samples. Twelve groups of microorganisms were targeted by viable plate counts revealing a dominance of mesophilic cocci. All rennets were able to acidify ultrahigh-temperature-processed (UHT) milk as shown by pH and total titratable acidity (TTA). Presumptive LAB isolated at the highest dilutions of acidified milks were phenotypically characterized, grouped, differentiated at the strain level by randomly amplified polymorphic DNA (RAPD)-PCR analysis, and subjected to 16S rRNA gene sequencing. Only 18 strains were clearly identified at the species level, as Enterococcus casseliflavus, Enterococcus faecium, Enterococcus faecalis, Enterococcus lactis, Lactobacillus delbrueckii, and Streptococcus thermophilus, while the other strains, all belonging to the genus Enterococcus, could not be allotted into any previously described species. The phylogenetic analysis showed that these strains might represent different unknown species. All strains were evaluated for their dairy technological performances. All isolates produced diacetyl, and 10 of them produced a rapid pH drop in milk, but only 3 isolates were also autolytic. This work showed that animal rennet pastes can be sources of LAB, mainly enterococci, that might contribute to the microbial diversity associated with dairy productions. PMID:24441167

[Cloning and gene expression in lactic acid bacteria].

PubMed

Bondarenko, V M; Beliavskaia, V A

2000-01-01

The possibility of using the genera Lactobacillus and Lactococcus as vector representatives is widely discussed at present. The prospects of the construction of recombinant bacteria are closely connected with the solution of a number of problems: the level of the transcription of cloned genes, the effectiveness of the translation of heterologous mRNA, the stability of protein with respect to bacterial intracellular proteases, the method by protein molecules leave the cell (by secretion or as the result of lysis). To prevent segregation instability, the construction of vector molecules on the basis of stable cryptic plasmids found in wild strains of lactic acid bacteria was proposed. High copying plasmids with low molecular weight were detected in L. plantarum and L. pentosus strains. Several plasmids with molecular weights of 1.7, 1.8 and 2.3 kb were isolated from bacterial cells to be used as the basis for the construction of vector molecules. Genes of chloramphenicol- and erythromycin-resistance from Staphylococcus aureus plasmids were used as marker genes ensuring cell transformation. The vector plasmids thus constructed exhibited high transformation activity in the electroporation of different strains, including L. casei, L. plantarum, L. acidophilus, L. fermentum and L. brevis which could be classified with the replicons of a wide circle of hosts. But the use of these plasmids was limited due to the risk of the uncontrolled dissemination of recombinant plasmids. L. acidophilus were also found to have strictly specific plasmids with good prospects of being used as the basis for the creation of vectors, incapable of dissemination. In addition to the search of strain-specific plasmids, incapable of uncontrolled gene transmission, the use of chromosome-integrated heterologous genes is recommended in cloning to ensure the maximum safety.

Characterization of some bacteriocins produced by lactic acid bacteria isolated from fermented foods.

PubMed

Grosu-Tudor, Silvia-Simona; Stancu, Mihaela-Marilena; Pelinescu, Diana; Zamfir, Medana

2014-09-01

Lactic acid bacteria (LAB) isolated from different sources (dairy products, fruits, fresh and fermented vegetables, fermented cereals) were screened for antimicrobial activity against other bacteria, including potential pathogens and food spoiling bacteria. Six strains have been shown to produce bacteriocins: Lactococcus lactis 19.3, Lactobacillus plantarum 26.1, Enterococcus durans 41.2, isolated from dairy products and Lactobacillus amylolyticus P40 and P50, and Lactobacillus oris P49, isolated from bors. Among the six bacteriocins, there were both heat stable, low molecular mass polypeptides, with a broad inhibitory spectrum, probably belonging to class II bacteriocins, and heat labile, high molecular mass proteins, with a very narrow inhibitory spectrum, most probably belonging to class III bacteriocins. A synergistic effect of some bacteriocins mixtures was observed. We can conclude that fermented foods are still important sources of new functional LAB. Among the six characterized bacteriocins, there might be some novel compounds with interesting features. Moreover, the bacteriocin-producing strains isolated in our study may find applications as protective cultures.

Molecular taxonomy and phylogenetic position of lactic acid bacteria.

PubMed

Stackebrandt, E; Teuber, M

1988-03-01

Lactic acid bacteria, important in food technology, are Gram-positive organisms exhibiting a DNA G + C content of less than 50 mol%. Phylogenetically they are members of the Clostridium-Bacillus subdivision of Gram-positive eubacteria. Lactobacillus and streptococci together with related facultatively anaerobic taxa evolved as individual lines of descent about 1.5-2 billion years ago when the earth passed from an anaerobic to an aerobic environment. In contrast to the traditional, morphology-based classification, the genus Lactobacillus is intermixed with strains of Pediococcus and Leuconostoc. Similarly, the physiology-based clustering of lactobacilli into Thermo-, Strepto- and Betabacterium does not agree with their phylogenetic relationships. On the other hand, the phenotypically defined genus Streptococcus is not a phylogenetic coherent genus but its members fall into at least 3 moderately related genera, i.e. Streptococcus, Lactococcus and Enterococcus. The genus Bifidobacterium, frequently grouped with the lactobacilli, is the most ancient group of the second, the Actinomycetes subdivision of the Gram-positive eubacteria. In addition, propionibacteria, microbacteria and brevibacteria belong to this subdivision but the latter organisms appear as offshoots of non-lactic acid bacteria.

Natural exopolysaccharides enhance survival of lactic acid bacteria in frozen dairy desserts.

PubMed

Hong, S H; Marshall, R T

2001-06-01

Viable lactic acid-producing bacteria in frozen dairy desserts can be a source of beta-galactosidase for persons who absorb lactose insufficiently. However, freezing kills many of the cells, causing loss of enzymatic activity. Cultures selected for high beta-galactosidase activities and high survival rates in the presence of bile were examined for survivability during freezing in reduced-fat ice cream. Encapsulated S. thermophilus strains survived better than their nonencapsulated mutants in reduced-fat ice cream after freezing and frozen storage at -29 degrees C for 16 d (28 vs. 19%). However, a small nonencapsulated strain of Lactobacillus delbrueckii sp. bulgaricus survived better than the large encapsulated strain in reduced-fat ice cream. Factors that improved survival of encapsulated S. thermophilus 1068 in ice cream were 1) harvest of cells in the late-log phase of growth at 37 degrees C rather than at 40, 42.5, or 45 degrees C; 2) overrun at 50% rather than 100%; and 3) storage at -17 degrees C rather than -23 or -29 degrees C. Survival of strain ST1068 was unaffected by 1) neutralization of acid during growth or 2) substitution of nitrogen for air in building overrun.

A new laboratory cultivation of Paramecium bursaria using non-pathogenic bacteria strains.

PubMed

Bator, Tomasz

2010-01-01

In most studies dealing with the laboratory cultivation of paramecia (Paramecium bursaria), Klebsiella pneumoniae bacteria are used to inoculate the medium. However, Klebsiella pneumoniae is a typical pathogen, and its use is always associated with a risk of infection. The aim of the present research was to examine non-pathogenic bacteria strains as components of the medium for Paramecium bursaria. The paramecia were incubated on lettuce infusions bacterized with different bacteria strains: Bacillus subtilis DSM 10, Bacillus megaterium DSM 32, Escherichia coli DSM 498, Micrococcus luteus DSM 348. A strain derived from the natural habitat of Paramecium bursaria was used as the control one. Experiments were conducted under constant light and in the dark. Paramecia cells were counted under a stereomicroscope on consecutive days of incubation. The obtained results show that the most intensive growth of Paramecium bursaria occurs in the presence of Escherichia coli DSM 498. The use of this strain as a component of the medium allows one to obtain a high number of ciliates regardless of the light conditions. It can be concluded that the Paramecium bursaria cultivation procedure can be modified by using the non-pathogenic bacteria strain Escherichia coli DSM 498 instead of Klebsiella pneumoniae.

Bioconversion Using Lactic Acid Bacteria: Ginsenosides, GABA, and Phenolic Compounds.

PubMed

Lee, Na-Kyoung; Paik, Hyun-Dong

2017-05-28

Lactic acid bacteria (LAB) are used as fermentation starters in vegetable and dairy products and influence the pH and flavors of foods. For many centuries, LAB have been used to manufacture fermented foods; therefore, they are generally regarded as safe. LAB produce various substances, such as lactic acid, β-glucosidase, and β-galactosidase, making them useful as fermentation starters. Existing functional substances have been assessed as fermentation substrates for better component bioavailability or other functions. Representative materials that were bioconverted using LAB have been reported and include minor ginsenosides, γ-aminobutyric acid, equol, aglycones, bioactive isoflavones, genistein, and daidzein, among others. Fermentation mainly involves polyphenol and polysaccharide substrates and is conducted using bacterial strains such as Streptococcus thermophilus, Lactobacillus plantarum, and Bifidobacterium sp. In this review, we summarize recent studies of bioconversion using LAB and discuss future directions for this field.

Characteristics of lactic acid bacteria isolates and their effect on silage fermentation of fruit residues.

PubMed

Yang, Jinsong; Tan, Haisheng; Cai, Yimin

2016-07-01

The natural lactic acid bacteria (LAB) population, chemical composition, and silage fermentation of fruit residues were studied. Eighty-two strains of LAB were isolated from fruit residues such as banana leaf and stem, pineapple peel, and papaya peel. All strains were gram-positive and catalase-negative bacteria, and they were divided into 7 groups (A-G) according to morphological and biochemical characters. Strains in groups A to F were rods, and group G was cocci. Group F produced gas from glucose; other groups did not. Groups A to C and F formed dl-lactic acid, whereas groups D, E, and G formed l-lactic acid. Based on the 16S rRNA gene sequence and DNA-DNA hybridization analysis, groups A to G strains were identified as Lactobacillus plantarum (54.9% of the total isolates), Lactobacillus paraplantarum (3.6%), Lactobacillus nagelii (8.5%), Lactobacillus perolens (4.9%), Lactobacillus casei (11.0%), Lactobacillus fermentum (9.8%), and Enterococcus gallinarum (7.3%), respectively. Lactobacillus plantarum and Lactobacillus casei are the most frequently isolated from fruit residues as a dominant species, and they could grow at a lower pH conditions and produce more lactic acid than other isolates. Pineapple and papaya peels contained higher crude protein (11.5-13.8%) and water-soluble carbohydrate (16.8-22.4%), but lower acid detergent fiber contents (21.2 to 26.4%) than banana stems and leaves (8.2% crude protein, 42.8% acid detergent fiber, and 5.1% water-soluble carbohydrate). Compared with banana stem and leaf silages, the pineapple and papaya peel silages were well preserved with a lower pH and higher lactate content. The study suggests that the fruit residues contain excellent LAB species and abundant feed nutrients, and that they can be preserved as silage to be potential food resources for livestock. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Simultaneous and successive inoculations of yeasts and lactic acid bacteria on the fermentation of an unsulfited Tannat grape must

PubMed Central

Muñoz, Viviana; Beccaria, Bruno; Abreo, Eduardo

2014-01-01

Interactions between yeasts and lactic acid bacteria are strain specific, and their outcome is expected to change in simultaneous alcoholic - malolactic fermentations from the pattern observed in successive fermentations. One Oenococcus oeni strain Lalvin VP41™ was inoculated with two Saccharomyces cerevisiae strains either simultaneously, three days after the yeast inoculation, or when alcoholic fermentation was close to finish. Early bacterial inoculations with each yeast strain allowed for the growth of the bacterial populations, and the length of malolactic fermentation was reduced to six days. Alcoholic fermentation by Lalvin ICV D80® yeast strain left the highest residual sugar, suggesting a negative effect of the bacterial growth and malolactic activity on its performance. In sequential inoculations the bacterial populations did not show actual growth with either yeast strain. In this strategy, both yeast strains finished the alcoholic fermentations, and malolactic fermentations took longer to finish. Lalvin ICV D80® allowed for higher viability and activity of the bacterial strain than Fermicru UY4® under the three inoculation strategies. This was beneficial for the sequential completion of both fermentations, but negatively affected the completion of alcoholic fermentation by Lalvin ICV D80® in the early bacteria additions. Conversely, Fermicru UY4®, which was rather inhibitory towards the bacteria, favored the timely completion of both fermentations simultaneously. As bacteria in early inoculations with low or no SO2 addition can be expected to multiply and interact with fermenting yeasts, not only are the yeast-bacterium strains combination and time point of the inoculation to be considered, but also the amount of bacteria inoculated. PMID:24948914

Molecular identification and physiological characterization of yeasts, lactic acid bacteria and acetic acid bacteria isolated from heap and box cocoa bean fermentations in West Africa.

PubMed

Visintin, Simonetta; Alessandria, Valentina; Valente, Antonio; Dolci, Paola; Cocolin, Luca

2016-01-04

Yeast, lactic acid bacteria (LAB) and acetic acid bacteria (AAB) populations, isolated from cocoa bean heap and box fermentations in West Africa, have been investigated. The fermentation dynamicswere determined by viable counts, and 106 yeasts, 105 LAB and 82 AAB isolateswere identified by means of rep-PCR grouping and sequencing of the rRNA genes. During the box fermentations, the most abundant species were Saccharomyces cerevisiae, Candida ethanolica, Lactobacillus fermentum, Lactobacillus plantarum, Acetobacter pasteurianus and Acetobacter syzygii, while S. cerevisiae, Schizosaccharomyces pombe, Hanseniaspora guilliermondii, Pichia manshurica, C. ethanolica, Hanseniaspora uvarum, Lb. fermentum, Lb. plantarum, A. pasteurianus and Acetobacter lovaniensis were identified in the heap fermentations. Furthermore, the most abundant species were molecularly characterized by analyzing the rep-PCR profiles. Strains grouped according to the type of fermentations and their progression during the transformation process were also highlighted. The yeast, LAB and AAB isolates were physiologically characterized to determine their ability to grow at different temperatures, as well as at different pH, and ethanol concentrations, tolerance to osmotic stress, and lactic acid and acetic acid inhibition. Temperatures of 45 °C, a pH of 2.5 to 3.5, 12% (v/v) ethanol and high concentrations of lactic and acetic acid have a significant influence on the growth of yeasts, LAB and AAB. Finally, the yeastswere screened for enzymatic activity, and the S. cerevisiae, H. guilliermondii, H. uvarumand C. ethanolica species were shown to possess several enzymes that may impact the quality of the final product.

Metabolic strategies of beer spoilage lactic acid bacteria in beer.

PubMed

Geissler, Andreas J; Behr, Jürgen; von Kamp, Kristina; Vogel, Rudi F

2016-01-04

Beer contains only limited amounts of readily fermentable carbohydrates and amino acids. Beer spoilage lactic acid bacteria (LAB) have to come up with metabolic strategies in order to deal with selective nutrient content, high energy demand of hop tolerance mechanisms and a low pH. The metabolism of 26 LAB strains of 6 species and varying spoilage potentialwas investigated in order to define and compare their metabolic capabilities using multivariate statistics and outline possible metabolic strategies. Metabolic capabilities of beer spoilage LAB regarding carbohydrate and amino acids did not correlate with spoilage potential, but with fermentation type (heterofermentative/homofermentative) and species. A shift to mixed acid fermentation by homofermentative (hof) Pediococcus claussenii and Lactobacillus backii was observed as a specific feature of their growth in beer. For heterofermentative (hef) LAB a mostly versatile carbohydrate metabolism could be demonstrated, supplementing the known relevance of organic acids for their growth in beer. For hef LAB a distinct amino acid metabolism, resulting in biogenic amine production, was observed, presumably contributing to energy supply and pH homeostasis.

Intraspecies cellular fatty acids heterogeneity of Lactobacillus plantarum strains isolated from fermented foods in Ukraine.

PubMed

Garmasheva, I; Vasyliuk, O; Kovalenko, N; Ostapchuk, A; Oleschenko, L

2015-09-01

The intraspecies heterogeneity of cellular fatty acids composition of Lactobacillus plantarum strains isolated from Ukrainian traditional fermented foods was examined. Seven cellular fatty acids were identified. All Lact. plantarum strains investigated contained C16:0 (from 7·54 to 49·83% of total fatty acids), cC18:1 (3·23-38·67% of total fatty acids) and cycC19:0 acids (9·03-67·68% of total fatty acids) as the major fatty acids. The tC18:1 acid made up 1·47-22·0% of the total fatty acids. The C14:0 and C16:1 acids were present in small amounts (0·22-6·96% and 0·66-7·42% respectively) in most Lact. plantarum strains. Differences in relative contents of some fatty acids between Lact. plantarum strains depending on the source isolation were found. Isolates of dairy origin contained slightly greater levels of the C16:0 and tC18:1 fatty acids and lower levels of the cC18:1 than strains obtained from fermented vegetables. The origin of Lact. plantarum strains affects their fatty acids composition, which in turn, appears to be related to their ability to growth under stress factors. Cellular fatty acids composition is an important chemotaxonomic characteristic of bacterial cells. At the same time cellular fatty acids play a key role in maintaining the viability of micro-organisms in different environmental conditions. In this study, intraspecies heterogeneity of cellular fatty acids composition of Lactobacillus plantarum strains was examined. This work provides novel and important information about a relationship between cellular fatty acids composition of Lact. plantarum strains and source of isolation or stress resistance profile. Our results showed that cellular fatty acids composition is quite diverse among Lact. plantarum strains derived from different sources and may reflect previous cell's history. Our findings should be considered in chemotaxonomic studies of lactic acid bacteria and its ecology. © 2015 The Society for Applied Microbiology.

Functional properties of lactic acid bacteria isolated from ethnic fermented vegetables of the Himalayas.

PubMed

Tamang, Jyoti Prakash; Tamang, Buddhiman; Schillinger, Ulrich; Guigas, Claudia; Holzapfel, Wilhelm H

2009-09-30

A total of 94 strains of Lactic acid bacteria (LAB), previously isolated from ethnic fermented vegetables and tender bamboo shoots of the Himalayas, were screened for functional properties such as acidification capacity, enzymatic activities, degradation of antinutritive factors and oligosaccharides, production of biogenic amines, hydrophobicity and adherence to mucus secreting HT29 MTX cells. Strong acidification and coagulation activities of LAB strains were recorded. Most of the LAB strains showed antimicrobial activities against the used indicator strains; however, only Lb. plantarum IB2 (BFE 948) isolated from inziangsang, a fermented leafy vegetable product, produced a bacteriocin against Staphylococcus aureus S1. LAB strains showed enzymatic activities and also degraded oligosaccharides. Almost all the strains of LAB were non-producers of biogenic amines except few strains. Some strains of Lb. plantarum showed more than 70% hydrophobicity. Adherence to the mucus secreting HT29 MTX cells was also shown by seven strains indicating their probiotic nature.

[Mitigating the repress of cinnamic acid to cucumber growth by microbial strain].

PubMed

Yu, Guo-hui; Xie, Yin-hua; Chen, Yan-hong; Chen, Yuan-feng; Cheng, Ping

2006-12-01

Cucumber is one of the most important vegetable species. Its continuous planting has become a common practice demand in many areas of China, but an obstacle from continuous planting made sustainable production of this crop to be prohibited. The self-toxic effect was considered as an important negative factor to continuous cropping cucumber. And cinnamic acid was found to be the main substance to cause self-toxic. Strain Ha8, which isolated from waste water estuary in Zhuhai city and has been authenticated as Cellulosimicrobium cellulans, was found to be able to degrade cinnamic acid, benzoic acid, paraaminobenzoic acid and phenol. Its biologic degrading rate to cinnamic acid was 64.1% and its total degrading rate to cinnamic acid was 79.32% . Therefore, strain Ha8 was used to mitigate the growth stress of cucumber caused by cinnamic acid in the research. In the experiment by hydroponic culturing method, it was found that the stem length, root length, stem weight, leaf weight, root weight, numbers of flower and harvest weight of cucumbers were lower than those untreated ones when added 2micromol/L or 10micromol/L cinnamic acid in culturing solution. But when added 10(7)cfu/L of strain Ha8 and 2micromol/L or 10micromol/L cinnamic acid in same culturing solution, these parameters were higher than those treated only by 2mircomol/L or 10micromol/L cinnamic acid. The result shown that strain Ha8 could mitigate the self-toxic effect caused by cinnamic acid. In edaphic culturing experiments, it was found that organic fertilizer mixed with strain Ha8 could mitigate the growth stress of cucumber caused by 100mg/kg cinnamic acid. When added 3mg/kg sterilized organic fertilizer with strain Ha8 (> or = 10(6)cfu/g dry organic fertilizer) in the culturing soil, the result was satisfied. This treatment could not only improve the growth of cucumber, enhance their root dehydrogenase activity and output, promote their nutrition absorption rate, but also adjust the microbial groups in

Quantitative analyses of the bacterial microbiota of rearing environment, tilapia and common carp cultured in earthen ponds and inhibitory activity of its lactic acid bacteria on fish spoilage and pathogenic bacteria.

PubMed

Kaktcham, Pierre Marie; Temgoua, Jules-Bocamdé; Ngoufack Zambou, François; Diaz-Ruiz, Gloria; Wacher, Carmen; Pérez-Chabela, María de Lourdes

2017-02-01

The present study aimed to evaluate the bacterial load of water, Nile Tilapia and common Carp intestines from earthen ponds, isolate lactic acid bacteria (LAB) and assess their antimicrobial activity against fish spoilage and pathogenic bacteria. Following enumeration and isolation of microorganisms the antimicrobial activity of the LAB isolates was evaluated. Taxonomic identification of selected antagonistic LAB strains was assessed, followed by partial characterisation of their antimicrobial metabolites. Results showed that high counts (>4 log c.f.u ml -1 or 8 log c.f.u g -1 ) of total aerobic bacteria were recorded in pond waters and fish intestines. The microbiota were also found to be dominated by Salmonella spp., Vibrio spp., Staphylococcus spp. and Escherichia coli. LAB isolates (5.60%) exhibited potent direct and extracellular antimicrobial activity against the host-derived and non host-derived spoilage and pathogenic bacteria. These antagonistic isolates were identified and Lactococcus lactis subsp. lactis was found as the predominant (42.85%) specie. The strains displayed the ability to produce lactic, acetic, butyric, propionic and valeric acids. Bacteriocin-like inhibitory substances with activity against Gram-positive and Gram-negative (Vibrio spp. and Pseudomonas aeruginosa) bacteria were produced by three L. lactis subsp. lactis strains. In this study, the LAB from the microbiota of fish and pond water showed potent antimicrobial activity against fish spoilage or pathogenic bacteria from the same host or ecological niche. The studied Cameroonian aquatic niche is an ideal source of antagonistic LAB that could be appropriate as new fish biopreservatives or disease control agents in aquaculture under tropical conditions in particular or worldwide in general.

Demonstrating Effectiveness of Antibiotics Against Known Bacteria Strains

ERIC Educational Resources Information Center

Keefe, Lois M.

1977-01-01

Procedures are described for showing the effectiveness of antibiotics (penicillin, ampicillin, and tetracycline) against a nonpathogenic bacteria strain (Bacillus cereus). Methods are outlined for preparing nutrient agar, sterilizing tubes, pouring agar plates, preparing antibiotic discs, and transferring antibiotic discs to agar plates. (CS)

High γ-aminobutyric acid production from lactic acid bacteria: Emphasis on Lactobacillus brevis as a functional dairy starter.

PubMed

Wu, Qinglong; Shah, Nagendra P

2017-11-22

γ-Aminobutyric acid (GABA) and GABA-rich foods have shown anti-hypertensive and anti-depressant activities as the major functions in humans and animals. Hence, high GABA-producing lactic acid bacteria (LAB) could be used as functional starters for manufacturing novel fermented dairy foods. Glutamic acid decarboxylases (GADs) from LAB are highly conserved at the species level based on the phylogenetic tree of GADs from LAB. Moreover, two functionally distinct GADs and one intact gad operon were observed in all the completely sequenced Lactobacillus brevis strains suggesting its common capability to synthesize GABA. Difficulties and strategies for the manufacture of GABA-rich fermented dairy foods have been discussed and proposed, respectively. In addition, a genetic survey on the sequenced LAB strains demonstrated the absence of cell envelope proteinases in the majority of LAB including Lb. brevis, which diminishes their cell viabilities in milk environments due to their non-proteolytic nature. Thus, several strategies have been proposed to overcome the non-proteolytic nature of Lb. brevis in order to produce GABA-rich dairy foods.

Production of bioactive substances by intestinal bacteria as a basis for explaining probiotic mechanisms: bacteriocins and conjugated linoleic acid.

PubMed

O'Shea, Eileen F; Cotter, Paul D; Stanton, Catherine; Ross, R Paul; Hill, Colin

2012-01-16

The mechanisms by which intestinal bacteria achieve their associated health benefits can be complex and multifaceted. In this respect, the diverse microbial composition of the human gastrointestinal tract (GIT) provides an almost unlimited potential source of bioactive substances (pharmabiotics) which can directly or indirectly affect human health. Bacteriocins and fatty acids are just two examples of pharmabiotic substances which may contribute to probiotic functionality within the mammalian GIT. Bacteriocin production is believed to confer producing strains with a competitive advantage within complex microbial environments as a consequence of their associated antimicrobial activity. This has the potential to enable the establishment and prevalence of producing strains as well as directly inhibiting pathogens within the GIT. Consequently, these antimicrobial peptides and the associated intestinal producing strains may be exploited to beneficially influence microbial populations. Intestinal bacteria are also known to produce a diverse array of health-promoting fatty acids. Indeed, certain strains of intestinal bifidobacteria have been shown to produce conjugated linoleic acid (CLA), a fatty acid which has been associated with a variety of systemic health-promoting effects. Recently, the ability to modulate the fatty acid composition of the liver and adipose tissue of the host upon oral administration of CLA-producing bifidobacteria and lactobacilli was demonstrated in a murine model. Importantly, this implies a potential therapeutic role for probiotics in the treatment of certain metabolic and immunoinflammatory disorders. Such examples serve to highlight the potential contribution of pharmabiotic production to probiotic functionality in relation to human health maintenance. Copyright © 2011 Elsevier B.V. All rights reserved.

Growth and fatty acid characterization of microalgae isolated from municipal waste-treatment systems and the potential role of algal-associated bacteria in feedstock production

PubMed Central

Stemmler, Kevin; Massimi, Rebecca

2016-01-01

Much research has focused on growing microalgae for biofuel feedstock, yet there remain concerns about the feasibility of freshwater feedstock systems. To reduce cost and improve environmental sustainability, an ideal microalgal feedstock system would be fed by municipal, agricultural or industrial wastewater as a main source of water and nutrients. Nonetheless, the microalgae must also be tolerant of fluctuating wastewater quality, while still producing adequate biomass and lipid yields. To address this problem, our study focused on isolating and characterizing microalgal strains from three municipal wastewater treatment systems (two activated sludge and one aerated-stabilization basin systems) for their potential use in biofuel feedstock production. Most of the 19 isolates from wastewater grew faster than two culture collection strains under mixotrophic conditions, particularly with glucose. The fastest growing wastewater strains included the genera Chlorella and Dictyochloris. The fastest growing microalgal strains were not necessarily the best lipid producers. Under photoautotrophic and mixotrophic growth conditions, single strains of Chlorella and Scenedesmus each produced the highest lipid yields, including those most relevant to biodiesel production. A comparison of axenic and non-axenic versions of wastewater strains showed a notable effect of commensal bacteria on fatty acid composition. Strains grown with bacteria tended to produce relatively equal proportions of saturated and unsaturated fatty acids, which is an ideal lipid blend for biodiesel production. These results not only show the potential for using microalgae isolated from wastewater for growth in wastewater-fed feedstock systems, but also the important role that commensal bacteria may have in impacting the fatty acid profiles of microalgal feedstock. PMID:26989618

Some current applications, limitations and future perspectives of lactic acid bacteria as probiotics

PubMed Central

Evivie, Smith Etareri; Huo, Gui-Cheng; Igene, John Oamen; Bian, Xin

2017-01-01

ABSTRACT Several mechanism and non-mechanism-based studies supporting the claim that lactic acid bacteria (LAB) strains confer health benefits and play immune-modulatory roles were examined in this review. Probiotic applications of LAB on global burdens such as obesity and type-2 diabetes were discussed as well as the use of yoghurt and ice cream as important vehicles to convey several beneficial LAB strains. Probiotic and symbiotic dairy products may be used in the nearest future to treat a variety of health disorders. Current studies suggest that lactic acid bacteria possess anti-obesity and anti-diabetic propensities on their hosts and thus can play a crucial role in human health care. Research in the rheological and physicochemical properties of ice cream as well as its applications are also on the increase. These applications face certain hurdles including technological (for less developed countries), consumer acceptability of new functional foods may be influenced by culture, ethics or religion. There is need for more studies on the genetic basis for probiotic properties which will give further understanding regarding novel manipulation skills and applicability in nutrition and health sectors. More studies confirming the direct effects of probiotic LABs in lowering the spread of food-borne and other pathogens are also anticipated. PMID:28659729

MONITORING OF SYNERGISTIC ENHANCEMENT OF CAFFEIC ACID ON ESCHERICHIA COLI K-12 RECA::GFP STRAIN TREATED WITH DACARBAZINE.

PubMed

Matejczyk, Marzena; Swislocka, Renata; Kalinowska, Monika; Swidersk, Grzegorz; Lewandowsk, Wlodzimierz; Jablonska-Trypuo, Agata

2017-05-01

Caffeic acid and its derivatives because of its biological activities, including antioxidants, antithrombosis, antihypertensive, antifibrosis, antiviral, and anti-tumor properties are good candidates as adjuvants in anticancer therapy. The aim of this study was the examination of cyto- and genotoxic effect of caffeic acid on Escherichia coli K-12 recA::gfp strain treated with dacarbazine. Obtained results indicate that dacarbazine and caffeic acid influenced the reactivity of recA promoter and modulate the level of gfp expression in genetic construct rrcA::gfpmut2 in E. coli K-12. Simultaneuos administration of dacarbazine with caffeic acid caused the stronger inhibition of the bacteria growth than the dacarbazine and caffeic acid separated administration to bacteria cells. The simultaneous effect of the both tested chemicals - dacarbazine and caffeic acid indicated (cytostatic effect) anticancer activity in relation to bacteria cells. It suggests, that combination of known anticancer drug - dacarbazine w ith caffeic acid exerted synergistic cytotoxic and genotoxic effects toward E. coli K- 12 cells and indicated the possibility of usefulness of caffeic acid as a natural adjuvant in anticancer therapy.

Sulfate-reducing bacteria mediate thionation of diphenylarsinic acid under anaerobic conditions.

PubMed

Guan, Ling; Shiiya, Ayaka; Hisatomi, Shihoko; Fujii, Kunihiko; Nonaka, Masanori; Harada, Naoki

2015-02-01

Diphenylarsinic acid (DPAA) is often found as a toxic intermediate metabolite of diphenylchloroarsine or diphenylcyanoarsine that were produced as chemical warfare agents and were buried in soil after the World Wars. In our previous study Guan et al. (J Hazard Mater 241-242:355-362, 2012), after application of sulfate and carbon sources, anaerobic transformation of DPAA in soil was enhanced with the production of diphenylthioarsinic acid (DPTAA) as a main metabolite. This study aimed to isolate and characterize anaerobic soil microorganisms responsible for the metabolism of DPAA. First, we obtained four microbial consortia capable of transforming DPAA to DPTAA at a high transformation rate of more than 80% after 4 weeks of incubation. Sequencing for the bacterial 16S rRNA gene clone libraries constructed from the consortia revealed that all the positive consortia contained Desulfotomaculum acetoxidans species. In contrast, the absence of dissimilatory sulfite reductase gene (dsrAB) which is unique to sulfate-reducing bacteria was confirmed in the negative consortia showing no DPAA reduction. Finally, strain DEA14 showing transformation of DPAA to DPTAA was isolated from one of the positive consortia. The isolate was assigned to D. acetoxidans based on the partial 16S rDNA sequence analysis. Thionation of DPAA was also carried out in a pure culture of a known sulfate-reducing bacterial strain, Desulfovibrio aerotolerans JCM 12613(T). These facts indicate that sulfate-reducing bacteria are microorganisms responsible for the transformation of DPAA to DPTAA under anaerobic conditions.

Bile resistance in Lactococcus lactis strains varies with cellular fatty acid composition: analysis by using different growth media.

PubMed

Kimoto-Nira, Hiromi; Kobayashi, Miho; Nomura, Masaru; Sasaki, Keisuke; Suzuki, Chise

2009-05-31

Bile resistance is one of the basic characteristics of probiotic bacteria. The aim of this study was to investigate the characteristics of bile resistance in lactococci by studying the relationship between bile resistance and cellular fatty acid composition in lactococcci grown on different media. We determined the bile resistance of 14 strains in lactose-free M17 medium supplemented with either glucose only (GM17) or lactose only (LM17). Gas chromatographic analyses of free lipids extracted from the tested strains were used for determining their fatty acid composition. A correlation analysis of all strains grown in both media revealed significant positive correlations between bile resistance and relative contents of hexadecanoic acid and octadecenoic acid, and negative correlations between bile resistance and relative contents of hexadecenoic acid and C-19 cyclopropane fatty acid. It is also a fact that the fatty acids associated with bile resistance depended on species, strain, and/or growth medium. In L. lactis subsp. cremoris strains grown in GM17 medium, the bile-resistant strains had significantly more octadecenoic acid than the bile-sensitive strains. In LM17 medium, bile-resistant strains had significantly more octadecenoic acid and significantly less C-19 cyclopropane fatty acid than the bile-sensitive strains. In L. lactis subsp. lactis strains, bile resistances of some of the tested strains were altered by growth medium. Some strains were resistant to bile in GM17 medium but sensitive to bile in LM17 medium. Some strains were resistant in both media tested. The strains grown in GM17 medium had significantly more hexadecanoic acid and octadecenoic acid, and significantly less tetradecanoic acid, octadecadienoic acid and C-19 cyclopropane fatty acid than the strains grown in LM17 medium. In conclusion, the fatty acid compositions of the bile-resistant lactococci differed from those of the bile-sensitive ones. More importantly, our data suggest that

Evaluation of Petrifilm Lactic Acid Bacteria Plates for Counting Lactic Acid Bacteria in Food.

PubMed

Kanagawa, Satomi; Ohshima, Chihiro; Takahashi, Hajime; Burenqiqige; Kikuchi, Misato; Sato, Fumina; Nakamura, Ayaka; Mohamed, Shimaa M; Kuda, Takashi; Kimura, Bon

2018-06-01

Although lactic acid bacteria (LAB) are used widely as starter cultures in the production of fermented foods, they are also responsible for food decay and deterioration. The undesirable growth of LAB in food causes spoilage, discoloration, and slime formation. Because of these adverse effects, food companies test for the presence of LAB in production areas and processed foods and consistently monitor the behavior of these bacteria. The 3M Petrifilm LAB Count Plates have recently been launched as a time-saving and simple-to-use plate designed for detecting and quantifying LAB. This study compares the abilities of Petrifilm LAB Count Plates and the de Man Rogosa Sharpe (MRS) agar medium to determine the LAB count in a variety of foods and swab samples collected from a food production area. Bacterial strains isolated from Petrifilm LAB Count Plates were identified by 16S rDNA sequence analysis to confirm the specificity of these plates for LAB. The results showed no significant difference in bacterial counts measured by using Petrifilm LAB Count Plates and MRS medium. Furthermore, all colonies growing on Petrifilm LAB Count Plates were confirmed to be LAB, while yeast colonies also formed in MRS medium. Petrifilm LAB Count Plates eliminated the plate preparation and plate inoculation steps, and the cultures could be started as soon as a diluted food sample was available. Food companies are required to establish quality controls and perform tests to check the quality of food products; the use of Petrifilm LAB Count Plates can simplify this testing process for food companies.

[Clinical application of testing methods on acid-fast bacteria].

PubMed

Ichiyama, Satoshi; Suzuki, Katsuhiro

2005-02-01

Clinical bacteriology pertaining to acid-fast bacteria has made marked advances over the past decade, initiated by the development of a DNA probe kit for identification of acid-fast bacteria. Wide-spread use of nucleic acid amplification for rapid detection of tubercle bacillus contributed more greatly than any other factor to such advances in this field. At present, 90% of all kits used for nucleic acid amplification in the world are consumed in Japan. Unfortunately, not a few clinicians in Japan have a false idea that the smear method and nucleic acid amplification are necessary but culture is not. In any event nucleic acid amplification has exerted significant impacts on the routine works at bacteriology laboratories. Among others, collecting bacteria by pretreatment with NALC-NaOH has simplified the introduction of the collective mode smear method and liquid media. Furthermore, as clinicians have become increasingly more experienced with various methods of molecular biology, it now seems possible to apply these techniques for detection of genes encoding drug resistance and for utilization of molecular epidemiology in routine laboratory works. Meanwhile, attempts to diagnose acid-fast bacteriosis by checking blood for antibody have also been made, primarily in Japan. At present, two kits for detecting antibodies to glycolipids (LAM, TDM, etc.) are covered by national health insurance in Japan. We have an impression that in Japan clinicians do not have adequate knowledge and skill to make full use of these new testing methods clinically. We, as the chairmen of this symposium, hope that this symposium will help clinicians increase their skill related to new testing methods, eventually leading to stimulation of advances in clinical practices related to acid-fast bacteria in Japan. 1. Smear microscopy by concentration method and broth culture system: Kazunari TSUYUGUCHI (Clinical Research Center, National Hospital Organization Kinki-chuo Chest Medical Center) Smear

Analysis of 16S rRNA gene lactic acid bacteria (LAB) isolate from Markisa fruit (Passiflora sp.) as a producer of protease enzyme and probiotics

NASA Astrophysics Data System (ADS)

Hidayat, Habibi

2017-03-01

16S rRNA gene analysis of bacteria lactic acid (LAB) isolate from Markisa Kuning Fruit (Passiflora edulis var. flavicarpa) as a producer of protease enzyme and probiotics has been done. The aim of the study is to determine the protease enzyme activity and 16S rRNA gene amplification using PCR. The calculation procedure was done to M4 isolate bacteria lactic acid (LAB) Isolate which has been resistant to acids with pH 2.0 in the manner of screening protease enzyme activity test result 6.5 to clear zone is 13 mm againts colony diametre is 2 mm. The results of study enzyme activity used spectrophotometer UV-Vis obtainable the regression equation Y=0.02983+0.001312X, with levels of protein M4 isolate is 0.6594 mg/mL and enzyme activity of obtainable is 0.8626 unit/ml while the spesific enzyme activity produced is 1.308 unit/mg. Then, 16S rRNA gene amplificatiom and DNA sequencing has been done. The results of study showed that the bacteria species contained from M4 bacteria lactic acid (LAB) isolate is Weisella cibiria strain II-I-59. Weisella cibiria strain II-I-59 is one of bacteria could be utilized in the digestive tract.

Phenotypic and genotypic characterization of lactic acid bacteria from traditional cheese in Khorramabad city of Iran with probiotic potential.

PubMed

Ghahremani, Enayat; Mardani, Mahnaz; Rezapour, Sadegh

2015-03-01

Lactic acid bacteria (LAB) with proteolitic activity are used as aromatic and antibacterial substances, cholesterol reduces, bile salt hydrolyses, and probiotic. The aims of this project were to isolate and identify natural LAB flora involved in traditional fermentation in cheeses of Khoramabad city and also to survey their probiotic potential. In order to achieve this goal, LAB were isolated and characterized using phenotypic and genotypic methods (PCR-sequencing); in the next stage, they were analyzed lowering cholesterol medium, hydrolysis of the bile, resistance to bile-resistant PH acidic stomach. At the end of the study, 88 cocci and 3 bacill were found: 58 Enterococcus faecium, 16 Enterococcus hirae, 5 Lactococcus lactis, 3 Lactobacillus plantarum, and 9 undetermined. The probiotic results of the bacteria had effects on the reduction of cholesterol, resistance to stomach acid, had relative antibacterial effects, and some strains had effects on hydrolyzing the bile. For further identification, the PCR method and the application of 16s-DNA-ITS genes and its sequencing were found useful. This study showed that lactic acid bacteria in the traditional cheese of the Khorramabad city have relative probiotic effect and that these lactic acid bacteria in fermented milk are suitable.

Incidence of Bacteriocins Produced by Food-Related Lactic Acid Bacteria Active towards Oral Pathogens

PubMed Central

Zoumpopoulou, Georgia; Pepelassi, Eudoxie; Papaioannou, William; Georgalaki, Marina; Maragkoudakis, Petros A.; Tarantilis, Petros A.; Polissiou, Moschos; Tsakalidou, Effie; Papadimitriou, Konstantinos

2013-01-01

In the present study we investigated the incidence of bacteriocins produced by 236 lactic acid bacteria (LAB) food isolates against pathogenic or opportunistic pathogenic oral bacteria. This set of LAB contained several strains (≥17%) producing bacteriocins active against food-related bacteria. Interestingly only Streptococcus macedonicus ACA-DC 198 was able to inhibit the growth of Streptococcus oralis, Streptococcus sanguinis and Streptococcus gordonii, while Lactobacillus fermentum ACA-DC 179 and Lactobacillus plantarun ACA-DC 269 produced bacteriocins solely against Streptococcus oralis. Thus, the percentage of strains that were found to produce bacteriocins against oral bacteria was ~1.3%. The rarity of bacteriocins active against oral LAB pathogens produced by food-related LAB was unexpected given their close phylogenetic relationship. Nevertheless, when tested in inhibition assays, the potency of the bacteriocin(s) of S. macedonicus ACA-DC 198 against the three oral streptococci was high. Fourier-transform infrared spectroscopy combined with principal component analysis revealed that exposure of the target cells to the antimicrobial compounds caused major alterations of key cellular constituents. Our findings indicate that bacteriocins produced by food-related LAB against oral LAB may be rare, but deserve further investigation since, when discovered, they can be effective antimicrobials. PMID:23443163

Biodiversity of lactic acid bacteria in Moroccan soft white cheese (Jben).

PubMed

Ouadghiri, Mouna; Amar, Mohamed; Vancanneyt, Marc; Swings, Jean

2005-10-15

The bacterial diversity occurring in traditional Moroccan soft white cheese, produced in eight different regions in Morocco, was studied. A total of 164 lactic acid bacteria were isolated, purified and identified by whole-cell protein fingerprinting and rep-PCR genomic fingerprinting. The majority of the strains belonged to the genera Lactobacillus, Lactococcus, Leuconostoc and Enterococcus. Sixteen species were identified: Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacillus paracasei, Lactobacillus brevis, Lactobacillus buchneri, Lactococcus lactis, Lactococcus garvieae, Lactococcus raffinolactis, Leuconostoc pseudomesenteroides, Leuconostoc mesenteroides, Leuconostoc citreum, Eterococcus durans, Enterococcus faecalis, Enterococcus faecium, Enterococcus saccharominimus and Streptococcus sp.

Iso-branched 2- and 3-hydroxy fatty acids as characteristic lipid constituents of some gliding bacteria.

PubMed Central

Fautz, E; Rosenfelder, G; Grotjahn, L

1979-01-01

The fatty acids present in the total hydrolysates of several gliding bacteria (Myxococcus fulvus, Stigmatella aurantiaca, Cytophaga johnsonae, Cytophaga sp. strain samoa and Flexibacter elegans) were analyzed by combined gas-liquid chromatography and mass spectrometry. In addition to 13-methyl-tetradecanoic acid, 15-methyl-hexadecanoic acid, hexadecanoic acid, and hexadecenoic acid, 2- and 3-hydroxy fatty acids comprised up to 50% of the total fatty acids. The majority was odd-numbered and iso-branched. Small amounts of even-numbered and unbranched fatty acids were also present. Whereas 2-hydroxy-15-methyl hexadecanoic acid was characteristic for myxobacteria, 2-hydroxy-13-methyl-tetradecanoic acid, 3-hydroxy-13-methyl-tetradecanoic acid, and 3-hydroxy-15-methyl-hexadecanoic acid were dominant in the Cytophaga-Flexibacter group. PMID:118159

Rapid identification of acetic acid bacteria using MALDI-TOF mass spectrometry fingerprinting.

PubMed

Andrés-Barrao, Cristina; Benagli, Cinzia; Chappuis, Malou; Ortega Pérez, Ruben; Tonolla, Mauro; Barja, François

2013-03-01

Acetic acid bacteria (AAB) are widespread microorganisms characterized by their ability to transform alcohols and sugar-alcohols into their corresponding organic acids. The suitability of matrix-assisted laser desorption-time of flight mass spectrometry (MALDI-TOF MS) for the identification of cultured AAB involved in the industrial production of vinegar was evaluated on 64 reference strains from the genera Acetobacter, Gluconacetobacter and Gluconobacter. Analysis of MS spectra obtained from single colonies of these strains confirmed their basic classification based on comparative 16S rRNA gene sequence analysis. MALDI-TOF analyses of isolates from vinegar cross-checked by comparative sequence analysis of 16S rRNA gene fragments allowed AAB to be identified, and it was possible to differentiate them from mixed cultures and non-AAB. The results showed that MALDI-TOF MS analysis was a rapid and reliable method for the clustering and identification of AAB species. Copyright © 2012 Elsevier GmbH. All rights reserved.

Characterization of lactic acid bacteria isolated from infant faeces as potential probiotic starter cultures for fermented sausages.

PubMed

Rubio, Raquel; Jofré, Anna; Martín, Belén; Aymerich, Teresa; Garriga, Margarita

2014-04-01

A total of 109 lactic acid bacteria isolated from infant faeces were identified by partial 16S rRNA, cpn60 and/or pheS sequencing. Lactobacillus was the most prevalent genus, representing 48% of the isolates followed by Enterococcus (38%). Lactobacillus gasseri (21%) and Enterococcus faecalis (38%) were the main species detected. A further selection of potential probiotic starter cultures for fermented sausages focused on Lactobacillus as the most technologically relevant genus in this type of product. Lactobacilli strains were evaluated for their ability to grow in vitro in the processing conditions of fermented sausages and for their functional and safety properties, including antagonistic activity against foodborne pathogens, survival from gastrointestinal tract conditions (acidity, bile and pancreatin), tyramine production, antibiotic susceptibility and aggregation capacity. The best strains according to the results obtained were Lactobacillus casei/paracasei CTC1677, L. casei/paracasei CTC1678, Lactobacillus rhamnosus CTC1679, L. gasseri CTC1700, L. gasseri CTC1704, Lactobacillus fermentum CTC1693. Those strains were further assayed as starter cultures in model sausages. L. casei/paracasei CTC1677, L. casei/paracasei CTC1678 and L. rhamnosus CTC1679 were able to lead the fermentation and dominate (levels ca. 10(8) CFU/g) the endogenous lactic acid bacteria, confirming their suitability as probiotic starter cultures. Copyright © 2013 Elsevier Ltd. All rights reserved.

Freeze-drying of lactic acid bacteria.

PubMed

Fonseca, Fernanda; Cenard, Stéphanie; Passot, Stéphanie

2015-01-01

Lactic acid bacteria are of great importance for the food and biotechnology industry. They are widely used as starters for manufacturing food (e.g., yogurt, cheese, fermented meats, and vegetables) and probiotic products, as well as for green chemistry applications. Freeze-drying or lyophilization is a convenient method for preservation of bacteria. By reducing water activity to values below 0.2, it allows long-term storage and low-cost distribution at suprazero temperatures, while minimizing losses in viability and functionality. Stabilization of bacteria via freeze-drying starts with the addition of a protectant solution to the bacterial suspension. Freeze-drying includes three steps, namely, (1) freezing of the concentrated and protected cell suspension, (2) primary drying to remove ice by sublimation, and (3) secondary drying to remove unfrozen water by desorption. In this chapter we describe a method for freeze-drying of lactic acid bacteria at a pilot scale, thus allowing control of the process parameters for maximal survival and functionality recovery.

Impact of gluconic fermentation of strawberry using acetic acid bacteria on amino acids and biogenic amines profile.

PubMed

Ordóñez, J L; Sainz, F; Callejón, R M; Troncoso, A M; Torija, M J; García-Parrilla, M C

2015-07-01

This paper studies the amino acid profile of beverages obtained through the fermentation of strawberry purée by a surface culture using three strains belonging to different acetic acid bacteria species (one of Gluconobacter japonicus, one of Gluconobacter oxydans and one of Acetobacter malorum). An HPLC-UV method involving diethyl ethoxymethylenemalonate (DEEMM) was adapted and validated. From the entire set of 21 amino acids, multiple linear regressions showed that glutamine, alanine, arginine, tryptophan, GABA and proline were significantly related to the fermentation process. Furthermore, linear discriminant analysis classified 100% of the samples correctly in accordance with the microorganism involved. G. japonicus consumed glucose most quickly and achieved the greatest decrease in amino acid concentration. None of the 8 biogenic amines were detected in the final products, which could serve as a safety guarantee for these strawberry gluconic fermentation beverages, in this regard. Copyright © 2015 Elsevier Ltd. All rights reserved.

Characterization of Acetic Acid Bacteria in Traditional Acetic Acid Fermentation of Rice Vinegar (Komesu) and Unpolished Rice Vinegar (Kurosu) Produced in Japan

PubMed Central

Nanda, Kumiko; Taniguchi, Mariko; Ujike, Satoshi; Ishihara, Nobuhiro; Mori, Hirotaka; Ono, Hisayo; Murooka, Yoshikatsu

2001-01-01

Bacterial strains were isolated from samples of Japanese rice vinegar (komesu) and unpolished rice vinegar (kurosu) fermented by the traditional static method. Fermentations have never been inoculated with a pure culture since they were started in 1907. A total of 178 isolates were divided into groups A and B on the basis of enterobacterial repetitive intergenic consensus-PCR and random amplified polymorphic DNA fingerprinting analyses. The 16S ribosomal DNA sequences of strains belonging to each group showed similarities of more than 99% with Acetobacter pasteurianus. Group A strains overwhelmingly dominated all stages of fermentation of both types of vinegar. Our results indicate that appropriate strains of acetic acid bacteria have spontaneously established almost pure cultures during nearly a century of komesu and kurosu fermentation. PMID:11157275

Synergism between hydrogen peroxide and seventeen acids against five agri-food-borne fungi and one yeast strain.

PubMed

Martin, H; Maris, P

2012-12-01

The objective of this study was to evaluate fungicidal efficacy of hydrogen peroxide administered in combination with 17 mineral and organic acids authorized for use in the food industry. The assays were performed on a 96-well microplate using a microdilution technique based on the checkerboard titration method. The six selected strains (one yeast and five fungi) were reference strains and strains representative of contaminating fungi found in the food industry. Each synergistic hydrogen peroxide/acid combination found after fifteen minutes contact time at 20 °C in distilled water was then tested in conditions simulating four different use conditions. Twelve combinations were synergistic in distilled water, eleven of these remained synergistic with one or more of the four mineral and organic interfering substances selected. Hydrogen peroxide/formic acid combination remained effective against four strains and was never antagonistic against the other two fungi. Combinations with propionic acid and acetic acid stayed synergistic against two strains. Those with oxalic acid and lactic acid kept their synergism only against Candida albicans. No synergism was detected against Penicillium cyclopium. Synergistic combinations of disinfectants were revealed, among them the promising hydrogen peroxide/formic acid combination. A rapid screening method developed in our laboratory for bacteria was adapted to fungi and used to reveal the synergistic potential of disinfectants and/or sanitizers combinations. © 2012 The Society for Applied Microbiology.

Digestion of rice straw and oil palm fronds by microflora from rumen and termite bacteria, in vitro.

PubMed

Ramin, M; Alimon, A R; Panandam, J M; Sijam, K; Javanmard, A; Abdullah, N

2008-02-15

The digestion and Volatile Fatty Acid (VFA) production from rice straw and oil palm fronds by cellulolytic bacteria isolated from the termite Coptotermes curvignathus were investigated. The bacteria were Acinetobacter strain Raminalimon, Enterobacter aerogenes strain Razmin C, Enterobacter cloacae strain Razmin B, Bacillus cereus strain Razmin A and Chryseobacterium kwangyangense strain Cb. Acinetobacter strain Raminalimon is an aerobic bacterium, while the other species are facultative anaerobes. There were significant differences (p<0.05) among the bacteria for Dry Matter (DM) lost and acetic acid production from rice straw and Acinetobacter strain Raminalimon showed the highest activity. The facultative bacteria C. kwangyangense strain Cb (cfu mL(-1) 231 x 10(-6), OD: 0.5), E. cloacae (cfu mL(-1) 68 x 10(-7), OD: 0.5) and E. aerogenes (cfu mL(-1) 33 x 10(-7), OD: 0.5) were used for digestion study with the rumen fluid microflora. The in vitro gas production technique was applied for the comparative study and the parameters measured were pH, gas (volume), dry matter lost, acetic acid, propionic acid and butyric acid concentrations. pH was not significantly (p<0.05) different among the five treatments. The bacterium C. kwangyangense strain Cb showed the highest activity (p<0.05) for DM lost, acetic acid, propionic acid and butyric acid production from rice straw when compared to the other bacterial activities. There was no significance (p<0.05) difference between the three bacteria for the dry matter lost of oil palm fronds but the production of Volatile Fatty Acids (VFA) was significantly (p<0.05) high in the treatment which was inoculated with C. kwangyangense strain Cb. The Gen Bank NCBI/EMBL accession numbers for the bacterial strains are EU332791, EU305608, EU305609, EU294508 and EU169201.

Phenotypic and Genotypic Characterization of Some Lactic Acid Bacteria Isolated from Bee Pollen: A Preliminary Study

PubMed Central

BELHADJ, Hani; HARZALLAH, Daoud; BOUAMRA, Dalila; KHENNOUF, Seddik; Dahamna, Saliha; GHADBANE, Mouloud

2014-01-01

In the present work, five hundred and sixty-seven isolates of lactic acid bacteria were recovered from raw bee pollen grains. All isolates were screened for their antagonistic activity against both Gram-positive and Gram-negative pathogenic bacteria. Neutralized supernatants of 54 lactic acid bacteria (LAB) cultures from 216 active isolates inhibited the growth of indicator bacteria. They were phenotypically characterized, based on the fermentation of 39 carbohydrates. Using the simple matching coefficient and unweighted pair group algorithm with arithmetic averages (UPGMA), seven clusters with other two members were defined at the 79% similarity level. The following species were characterized: Lactobacillus plantarum, Lactobacillus fermentum, Lactococcus lactis, Pediococcus acidilactici, Pediococcus pentosaceus, and unidentified lactobacilli. Phenotypic characteristics of major and minor clusters were also identified. Partial sequencing of the 16S rRNA gene of representative isolates from each cluster was performed, and ten strains were assigned to seven species: Lactobacillus plantarum, Lactobacillus fermentum, Lactococcus lactis, Lactobacillus ingluviei, Pediococcus pentosaceus, Lactobacillus acidipiscis and Weissella cibaria. The molecular method used failed to determine the exact taxonomic status of BH0900 and AH3133. PMID:24936378

Phenotypic and genotypic characterization of some lactic Acid bacteria isolated from bee pollen: a preliminary study.

PubMed

Belhadj, Hani; Harzallah, Daoud; Bouamra, Dalila; Khennouf, Seddik; Dahamna, Saliha; Ghadbane, Mouloud

2014-01-01

In the present work, five hundred and sixty-seven isolates of lactic acid bacteria were recovered from raw bee pollen grains. All isolates were screened for their antagonistic activity against both Gram-positive and Gram-negative pathogenic bacteria. Neutralized supernatants of 54 lactic acid bacteria (LAB) cultures from 216 active isolates inhibited the growth of indicator bacteria. They were phenotypically characterized, based on the fermentation of 39 carbohydrates. Using the simple matching coefficient and unweighted pair group algorithm with arithmetic averages (UPGMA), seven clusters with other two members were defined at the 79% similarity level. The following species were characterized: Lactobacillus plantarum, Lactobacillus fermentum, Lactococcus lactis, Pediococcus acidilactici, Pediococcus pentosaceus, and unidentified lactobacilli. Phenotypic characteristics of major and minor clusters were also identified. Partial sequencing of the 16S rRNA gene of representative isolates from each cluster was performed, and ten strains were assigned to seven species: Lactobacillus plantarum, Lactobacillus fermentum, Lactococcus lactis, Lactobacillus ingluviei, Pediococcus pentosaceus, Lactobacillus acidipiscis and Weissella cibaria. The molecular method used failed to determine the exact taxonomic status of BH0900 and AH3133.

Assessment of probiotic properties of lactic acid bacteria isolated from Indonesian naturally fermented milk

NASA Astrophysics Data System (ADS)

Jatmiko, Yoga Dwi; Howarth, Gordon S.; Barton, Mary D.

2017-11-01

This study aimed to characterize the probiotic properties of lactic acid bacteria from the naturally fermented milk of Indonesia, namely dangke and dadih. Fifty-one representative lactic acid bacteria belonging to the species Lactobacillus Plantarum, Lactococcus lactis subsp. lactis and Enterococcus faecium were evaluated in vitro for potential probiotic properties based on their bile salt resistance, low pH tolerance, antimicrobial activity, antibiotic susceptibility and adherence to Caco-2 colon cancer cells. In addition, bacteriocin related gene (plantaricin A), bile salt hydrolase (bsh) and mannose-specific adhesin (msa) genes in the genome of lactobacilli were also examined. None of the dangke isolates, which belonged to the species L. lactis subsp. lactis tolerated low pH. However, eight of the isolates were able to grow in the presence of bile salts. It was observed that L. plantarum strain S1.30 and SL2.7 from dadih tolerated low pH, survived bile salt concentrations and were resistant to vancomycin. Furthermore, these strains also contained bacteriocin regulating gene (plantaricin A) and msa and bsh genes in their genome. However, only the strain S1.30 exhibited optimal antimicrobial activity against the selected pathogens and was able to adhere to Caco-2 cells by up to 82.24±0.14%. Antagonistic activity of L. lactis subsp. lactis from dadih and dangke was not detected. However, 73.94±1.26% adherence to Caco-2 cells was demonstrated by L. lactis subsp. lactis strain SL3.34 sourced from dangke. These results suggest that Lactobacillus plantarum strain S1.30 associated with dadih fulfilled the in vitro probiotic criteria and could be exploited for further in vivo evaluation. In addition, dadih was an effective probiotic carrier compared to dangke.

Virulence of plant pathogenic bacteria attenuated by degradation of fatty acid cell-to-cell signaling factors.

PubMed

Newman, Karyn L; Chatterjee, Subhadeep; Ho, Kimberly A; Lindow, Steven E

2008-03-01

Diffusible signal factor (DSF) is a fatty acid signal molecule involved in regulation of virulence in several Xanthomonas species as well as Xylella fastidiosa. In this study, we identified a variety of bacteria that could disrupt DSF-mediated induction of virulence factors in Xanthomonas campestris pv. campestris. While many bacteria had the ability to degrade DSF, several bacterial strains belonging to genera Bacillus, Paenibacillus, Microbacterium, Staphylococcus, and Pseudomonas were identified that were capable of particularly rapid degradation of DSF. The molecular determinants for rapid degradation of DSF in Pseudomonas spp. strain G were elucidated. Random transposon mutants of strain G lacking the ability to degrade DSF were isolated. Cloning and characterization of disrupted genes in these strains revealed that carAB, required for the synthesis of carbamoylphosphate, a precursor for pyrimidine and arginine biosynthesis is required for rapid degradation of DSF in strain G. Complementation of carAB mutants restored both pyrimidine prototrophy and DSF degradation ability of the strain G mutant. An Escherichia coli strain harboring carAB of Pseudomonas spp. strain G degrades DSF more rapidly than the parental strain, and overexpression of carAB in trans increased the ability of Pseudomonas spp. strain G to degrade as compared with the parental strain. Coinoculation of X. campestris pv. campestris with DSF-degrading bacteria into mustard and cabbage leaves reduced disease severity up to twofold compared with plants inoculated only with the pathogen. Likewise, disease incidence and severity in grape stems coinoculated with Xylella fastidiosa and DSF-degrading strains were significantly reduced compared with plants inoculated with the pathogen alone. Coinoculation of grape plants with a carAB mutant of Pseudomonas spp. strain G complemented with carAB in trans reduced disease severity as well or better than the parental strain. These results indicate that

Cd(II) Sorption on Montmorillonite-Humic acid-Bacteria Composites

PubMed Central

Du, Huihui; Chen, Wenli; Cai, Peng; Rong, Xingmin; Dai, Ke; Peacock, Caroline L.; Huang, Qiaoyun

2016-01-01

Soil components (e.g., clays, bacteria and humic substances) are known to produce mineral-organic composites in natural systems. Herein, batch sorption isotherms, isothermal titration calorimetry (ITC), and Cd K-edge EXAFS spectroscopy were applied to investigate the binding characteristics of Cd on montmorillonite(Mont)-humic acid(HA)-bacteria composites. Additive sorption and non-additive Cd(II) sorption behaviour is observed for the binary Mont-bacteria and ternary Mont-HA-bacteria composite, respectively. Specifically, in the ternary composite, the coexistence of HA and bacteria inhibits Cd adsorption, suggesting a “blocking effect” between humic acid and bacterial cells. Large positive entropies (68.1 ~ 114.4 J/mol/K), and linear combination fitting of the EXAFS spectra for Cd adsorbed onto Mont-bacteria and Mont-HA-bacteria composites, demonstrate that Cd is mostly bound to bacterial surface functional groups by forming inner-sphere complexes. All our results together support the assertion that there is a degree of site masking in the ternary clay mineral-humic acid-bacteria composite. Because of this, in the ternary composite, Cd preferentially binds to the higher affinity components-i.e., the bacteria. PMID:26792640

Lactobacillus micheneri sp. nov., Lactobacillus timberlakei sp. nov. and Lactobacillus quenuiae sp. nov., lactic acid bacteria isolated from wild bees and flowers.

PubMed

McFrederick, Quinn S; Vuong, Hoang Q; Rothman, Jason A

2018-06-01

Gram-stain-positive, rod-shaped, non-spore forming bacteria have been isolated from flowers and the guts of adult wild bees in the families Megachilidae and Halictidae. Phylogenetic analysis of the 16S rRNA gene indicated that these bacteria belong to the genus Lactobacillus, and are most closely related to the honey-bee associated bacteria Lactobacillus kunkeei (97.0 % sequence similarity) and Lactobacillus apinorum (97.0 % sequence similarity). Phylogenetic analyses of 16S rRNA genes and six single-copy protein coding genes, in situ and in silico DNA-DNA hybridization, and fatty-acid profiling differentiates the newly isolated bacteria as three novel Lactobacillus species: Lactobacillus micheneri sp. nov. with the type strain Hlig3 T (=DSM 104126 T ,=NRRL B-65473 T ), Lactobacillus timberlakei with the type strain HV_12 T (=DSM 104128 T ,=NRRL B-65472 T ), and Lactobacillus quenuiae sp. nov. with the type strain HV_6 T (=DSM 104127 T ,=NRRL B-65474 T ).

Mycobacterium avium subsp. paratuberculosis (Map) Fatty Acids Profile Is Strain-Dependent and Changes Upon Host Macrophages Infection

PubMed Central

Alonso-Hearn, Marta; Abendaño, Naiara; Ruvira, Maria A.; Aznar, Rosa; Landin, Mariana; Juste, Ramon A.

2017-01-01

Johne's disease is a chronic granulomatous enteritis of ruminants caused by the intracellular bacterium Mycobacterium avium subsp. paratuberculosis (Map). We previously demonstrated that Map isolates from sheep persisted within host macrophages in lower CFUs than cattle isolates after 7 days of infection. In the current study, we hypothesize that these phenotypic differences between Map isolates may be driven be the fatty acids (FAs) present on the phosphadidyl-1-myo-inositol mannosides of the Map cell wall that mediate recognition by the mannose receptors of host macrophages. FAs modifications may influence Map's envelope fluidity ultimately affecting pathogenicity. To test this hypothesis, we investigated the responses of two Map isolates from cattle (K10 isolate) and sheep (2349/06-1) to the bovine and ovine macrophage environment by measuring the FAs content of extracellular and intracellular bacteria. For this purpose, macrophages cell lines of bovine (BOMAC) and ovine (MOCL-4) origin were infected with the two isolates of Map for 4 days at 37°C. The relative FAs composition of the two isolates recovered from infected BOMAC and MOCL-4 cells was determined by gas chromatography and compared with that of extracellular bacteria and that of bacteria grown in Middlebrook 7H9 medium. Using this approach, we demonstrated that the FAs composition of extracellular and 7H9-grown bacteria was highly conserved within each Map isolate, and statistically different from that of intracellular bacteria. Analysis of FAs composition from extracellular bacteria enabled the distinction of the two Map strains based on the presence of the tuberculostearic acid (18:0 10Me) exclusively in the K10 strain of Map. In addition, significant differences in the content of Palmitic acid and cis-7 Palmitoleic acid between both isolates harvested from the extracellular environment were observed. Once the infection established itself in BOMAC and MOCL-4 cells, the FAs profiles of both Map

Dual-coated lactic acid bacteria: an emerging innovative technology in the field of probiotics.

PubMed

Alvarez-Calatayud, Guillermo; Margolles, Abelardo

2016-01-01

Probiotics are living micro-organisms that do not naturally have shelf life, and normally are weakly protected against the digestive action of the GI tract. A new dual coating technology has been developed in an effort to maximize survival, that is, to be able to reach the intestine alive and in sufficient numbers to confer the beneficial health effects on the host. Dual-coating of lactic acid bacteria (LAB) is the result of fourth-generation coating technology for the protection of these bacteria at least 100-fold or greater than the uncoated LAB. This innovative technique involves a first pH-dependent protein layer that protects bacteria from gastric acid and bile salt, and a second polysaccharide matrix that protects bacteria from external factors, such as humidity, temperature and pressure, as well as the digestive action during the passage through the GI tract. Dual-coated probiotic formulation is applicable to different therapeutic areas, including irritable bowel syndrome, atopic dermatitis, acute diarrhea, chronic constipation, Helicobacter pylori eradication, and prevention of antibiotic-associated diarrhea. An updated review of the efficacy of doubly coated probiotic strains for improving bacterial survival in the intestinal tract and its consequent clinical benefits in humans is here presented.

Quantitative analysis of the lactic acid and acetaldehyde produced by Streptococcus thermophilus and Lactobacillus bulgaricus strains isolated from traditional Turkish yogurts using HPLC.

PubMed

Gezginc, Y; Topcal, F; Comertpay, S; Akyol, I

2015-03-01

The present study was conducted to evaluate the lactic acid- and acetaldehyde-producing abilities of lactic acid bacterial species isolated from traditionally manufactured Turkish yogurts using HPLC. The lactic acid bacterial species purified from the yogurts were the 2 most widely used species in industrial yogurt production: Streptococcus thermophilus and Lactobacillus bulgaricus. These bacteria have the ability to ferment hexose sugars homofermentatively to generate lactic acid and some carbonyl compounds, such as acetaldehyde through pyruvate metabolism. The levels of the compounds produced during fermentation influence the texture and the flavor of the yogurt and are themselves influenced by the chemical composition of the milk, processing conditions, and the metabolic activity of the starter culture. In the study, morphological, biochemical, and molecular characteristics were employed to identify the bacteria obtained from homemade yogurts produced in different regions of Turkey. A collection of 91 Strep. thermophilus and 35 L. bulgaricus strains were investigated for their lactic acid- and acetaldehyde-formation capabilities in various media such as cow milk, LM17 agar, and aerobic-anaerobic SM17 agar or de Man, Rogosa, and Sharpe agar. The amounts of the metabolites generated by each strain in all conditions were quantified by HPLC. The levels were found to vary depending on the species, the strain, and the growth conditions used. Whereas lactic acid production ranged between 0 and 77.9 mg/kg for Strep. thermophilus strains, it ranged from 0 to 103.5 mg/kg for L. bulgaricus. Correspondingly, the ability to generate acetaldehyde ranged from 0 to 105.9 mg/kg in Strep. thermophilus and from 0 to 126.9 mg/kg in L. bulgaricus. Our study constitutes the first attempt to determine characteristics of the wild strains isolated from traditional Turkish yogurts, and the approach presented here, which reveals the differences in metabolite production abilities of the

[The antagonistic properties of microaerophilic bacteria isolated from the human and mink digestive tracts].

PubMed

Sudenko, V I; Groma, L I; Podgorskiĭ, V S

1996-01-01

Study of antagonistic properties of microaerophilic bacteria isolated from human and mink gastroenteric tract have helped to establish differences in species composition, quantity and level of antagonistic activity of the studied microorganisms in respect to pathogenic microflora. It is shown that lactic acid bacteria identified as Lactobacillus fermentum and L. reuteri prevail among the strains isolated from the stomach and thin intestine of minks kept in the 30-km zone of Chernobyl NPP. Species composition of microaerophilic bacteria isolated from the digestive tract of the control minks is more variable. Antagonistically active bifidobacteria prevail in large intestine of experimental and control animals. Strains of lactic acid bacteria with the expressed antagonistic activity belonging to L. bavaricus, L. reuteri, L. coryniformis and L. maltaromicus have been found parallel with such known producers of antibiotic-like substances as L. fermentum. L. acidophilum. Streptococcus faecalis and bifidobacteria. L. maltaromicus most frequently occurred among antagonistically active strains revealed in feces of people which stayed in the zone of liquidation of the Chernobyl accident. Microaerophilic strains of bacteria (lactic acid, bifidobacteria and enterococci) manifest the expressed antagonistic activity connected with the capacity to not only acid formation but also to accumulation of antibiotic products of unknown nature. A strain of lactic acid bacteria L. fermentum 91 has been isolated from the contents of human gastroenteric tract. These bacteria are distinguished by most expressed and stable antagonism and characterized by the lack of pathogenicity in respect of albino mice that may be used to raise the microorganism resistance to gastric diseases.

Effect of cerulenin on fatty acid composition and gene expression pattern of DHA-producing strain Colwellia psychrerythraea strain 34H.

PubMed

Wan, Xia; Peng, Yun-Feng; Zhou, Xue-Rong; Gong, Yang-Min; Huang, Feng-Hong; Moncalián, Gabriel

2016-02-06

Colwellia psychrerythraea 34H is a psychrophilic bacterium able to produce docosahexaenoic acid (DHA). Polyketide synthase pathway is assumed to be responsible for DHA production in marine bacteria. Five pfa genes from strain 34H were confirmed to be responsible for DHA formation by heterogeneous expression in Escherichia coli. The complexity of fatty acid profile of this strain was revealed by GC and GC-MS. Treatment of cells with cerulenin resulted in significantly reduced level of C16 monounsaturated fatty acid (C16:1(Δ9t), C16:1(Δ7)). In contrast, the amount of saturated fatty acids (C10:0, C12:0, C14:0), hydroxyl fatty acids (3-OH C10:0 and 3-OH C12:0), as well as C20:4ω3, C20:5ω3 and C22:6ω3 were increased. RNA sequencing (RNA-Seq) revealed the altered gene expression pattern when C. psychrerythraea cells were treated with cerulenin. Genes involved in polyketide synthase pathway and fatty acid biosynthesis pathway were not obviously affected by cerulenin treatment. In contrast, several genes involved in fatty acid degradation or β-oxidation pathway were dramatically reduced at the transcriptional level. Genes responsible for DHA formation in C. psychrerythraea was first cloned and characterized. We revealed the complexity of fatty acid profile in this DHA-producing strain. Cerulenin could substantially change the fatty acid composition by affecting the fatty acid degradation at transcriptional level. Acyl-CoA dehydrogenase gene family involved in the first step of β-oxidation pathway may be important to the selectivity of degraded fatty acids. In addition, inhibition of FabB protein by cerulenin may lead to the accumulation of malonyl-CoA, which is the substrate for DHA formation.

Metabolism of the /sup 18/O-methoxy substituent of 3-methoxybenzoic acid and other unlabeled methoxybenzoic acids by anaerobic bacteria. [Eubacterium limosum; Acetobacterium woodil; Syntrophococcus; Clostridium; Desulfotomaculum; Enterobacter

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

DeWeerd, J.A.; Saxena, A.; Nagle, D.P. Jr.

1988-05-01

The mechanism of the bioconversion of methoxylated benzoic acids to the hydroxylated derivatives was investigated with a model substrate and cultures of one anaerobic consortium, eight strict anaerobic bacteria, and one facultative anaerobic microorganism. We found that a haloaromatic dehalogenating consortium, a dehalogenating isolate from that consortium, Eubacterium, limosum, and a strain of Acetobacterium woodii metabolized 3-(methoxy-/sup 18/O)methoxybenzoic acid (3-anisic acid) to 3-(hydroxy-/sup 18/O)hydroxybenzoic acid stoichiometrically at rates of 1.5, 3.2, 52.4, and 36.7 nmol/min per mg of protein, respectively. A different strain of Acetobacterium and strains of Syntrophococcus, Clostridium Desulfotomaculum, Enterobacter, and an anaerobic bacterium, strain TH-001, were unablemore » to transform this compound. The O-demethylating ability of E. limosum was induced only with appropriate methoxylated benzoates but not with D-glucose, lactate, isoleucine, or methanol. Cross-acclimation and growth experiments with E. limosum showed a rate of metabolism that was an order of magnitude slower and showed no growth with either 4-methoxysalicylic acid (2-hydroxy-4-methoxybenzoic acid) or 4-anisic acid (4-methoxybenzoic acid) when adapted to 3-anisic acid. However, A. woodii NZva-16 showed slower rates and no growth with 3- or 4-methoxysalicylic acid when adapted to 3-anisic acid in similar experiments.« less

Lactic acid bacteria as oral delivery systems for biomolecules.

PubMed

Berlec, A; Ravnikar, M; Strukelj, B

2012-11-01

Lactic acid bacteria (LAB) have become increasingly studied over the last two decades as potential delivery systems for various biological molecules to the gastrointestinal tract. This article presents an overview of characteristics of LAB as delivery systems and of the applications which have already been developed. The majority of LAB strains are able to survive the intestinal passage and some are also able to persist and colonize the intestine. Several strains were in fact described as members of the human commensal flora. They can interact with their host and are able to deliver large molecular weight biomolecules across the epithelium via M-cells or dendritic cells. The most widely applied LAB species has been Lactococcus lactis; however species from genus Lactobacillus are gaining popularity and the first examples from genus Bifidobacterium are starting to emerge. Bacteria are mostly applied live and enable continuous delivery of the biomolecules. However, killed bacteria (e.g. gram-positive enhancer matrix), with bound biomolecules or as adjuvants, are also being developed. The techniques for genetic modification of LAB are well known. This review focuses on the delivery of recombinant proteins and DNA, which can cause either local or systemic effects. We divide recombinant proteins into antigens and therapeutic proteins. Delivery of antigens for the purpose of vaccination represents the most abundant application with numerous successful demonstrations of the efficacy on the animal model. Therapeutic proteins have mostly been developed for the treatment of the inflammatory bowel disease, by the delivery of anti-inflammatory cytokines, or downregulation of proinflammatory cytokines. Delivery of allergens for the modulation of allergic disorders represents the second most popular application of therapeutic proteins. The delivery of DNA by LAB was demonstrated and offers exciting opportunities, especially as a vaccine. New discoveries may eventually lead to the

The investigation of probiotic potential of lactic acid bacteria isolated from traditional Mongolian dairy products.

PubMed

Takeda, Shiro; Yamasaki, Keiko; Takeshita, Masahiko; Kikuchi, Yukiharu; Tsend-Ayush, Chuluunbat; Dashnyam, Bumbein; Ahhmed, Abdulatef M; Kawahara, Satoshi; Muguruma, Michio

2011-08-01

The aims of this study were to investigate the diversity of lactic acid bacteria (LAB) isolated from traditional Mongolian dairy products, and to estimate the probiotic potential of the isolated strains. We collected 66 samples of the traditional Mongolian dairy products tarag (n = 45), airag (n = 7), aaruul (n = 8), byasulag (n = 1) and eezgii (n = 5), from which 543 LAB strains were isolated and identified based on 16S ribosomal DNA sequence. The predominant species of those products were Lactobacillus (L.) delbrueckii ssp. bulgaricus, L. helveticus, L. fermentum, L. delbrueckii ssp. lactis and Lactococcus lactis ssp. lactis. However, we could not detect any LAB strains from eezgii. All LAB isolates were screened for tolerance to low pH and to bile acid, gas production from glucose, and adherence to Caco-2 cells. In vitro, we found 10 strains possess probiotic properties, and almost identified them as L. plantarum or L. paracasei subspecies, based on 16S ribosomal DNA and carbohydrate fermentation pattern. These strains were differentiated from each other individually by randomly amplified polymorphic DNA analysis. Additionally, it was notable that 6/10 strains were isolated from camel milk tarag from the Dornogovi province. 2011 The Authors. Animal Science Journal © 2011 Japanese Society of Animal Science.

Evidence of Two Functionally Distinct Ornithine Decarboxylation Systems in Lactic Acid Bacteria

PubMed Central

Romano, Andrea; Trip, Hein; Lonvaud-Funel, Aline; Lolkema, Juke S.

2012-01-01

Biogenic amines are low-molecular-weight organic bases whose presence in food can result in health problems. The biosynthesis of biogenic amines in fermented foods mostly proceeds through amino acid decarboxylation carried out by lactic acid bacteria (LAB), but not all systems leading to biogenic amine production by LAB have been thoroughly characterized. Here, putative ornithine decarboxylation pathways consisting of a putative ornithine decarboxylase and an amino acid transporter were identified in LAB by strain collection screening and database searches. The decarboxylases were produced in heterologous hosts and purified and characterized in vitro, whereas transporters were heterologously expressed in Lactococcus lactis and functionally characterized in vivo. Amino acid decarboxylation by whole cells of the original hosts was determined as well. We concluded that two distinct types of ornithine decarboxylation systems exist in LAB. One is composed of an ornithine decarboxylase coupled to an ornithine/putrescine transmembrane exchanger. Their combined activities results in the extracellular release of putrescine. This typical amino acid decarboxylation system is present in only a few LAB strains and may contribute to metabolic energy production and/or pH homeostasis. The second system is widespread among LAB. It is composed of a decarboxylase active on ornithine and l-2,4-diaminobutyric acid (DABA) and a transporter that mediates unidirectional transport of ornithine into the cytoplasm. Diamines that result from this second system are retained within the cytosol. PMID:22247134

In vaginal fluid, bacteria associated with bacterial vaginosis can be suppressed with lactic acid but not hydrogen peroxide

PubMed Central

2011-01-01

Background Hydrogen peroxide (H2O2) produced by vaginal lactobacilli is generally believed to protect against bacteria associated with bacterial vaginosis (BV), and strains of lactobacilli that can produce H2O2 are being developed as vaginal probiotics. However, evidence that led to this belief was based in part on non-physiological conditions, antioxidant-free aerobic conditions selected to maximize both production and microbicidal activity of H2O2. Here we used conditions more like those in vivo to compare the effects of physiologically plausible concentrations of H2O2 and lactic acid on a broad range of BV-associated bacteria and vaginal lactobacilli. Methods Anaerobic cultures of seventeen species of BV-associated bacteria and four species of vaginal lactobacilli were exposed to H2O2, lactic acid, or acetic acid at pH 7.0 and pH 4.5. After two hours, the remaining viable bacteria were enumerated by growth on agar media plates. The effect of vaginal fluid (VF) on the microbicidal activities of H2O2 and lactic acid was also measured. Results Physiological concentrations of H2O2 (< 100 μM) failed to inactivate any of the BV-associated bacteria tested, even in the presence of human myeloperoxidase (MPO) that increases the microbicidal activity of H2O2. At 10 mM, H2O2 inactivated all four species of vaginal lactobacilli but only one of seventeen species of BV-associated bacteria. Moreover, the addition of just 1% vaginal fluid (VF) blocked the microbicidal activity of 1 M H2O2. In contrast, lactic acid at physiological concentrations (55-111 mM) and pH (4.5) inactivated all the BV-associated bacteria tested, and had no detectable effect on the vaginal lactobacilli. Also, the addition of 10% VF did not block the microbicidal activity of lactic acid. Conclusions Under optimal, anaerobic growth conditions, physiological concentrations of lactic acid inactivated BV-associated bacteria without affecting vaginal lactobacilli, whereas physiological concentrations of H2O2

Effect of ammonium and amino acids on the growth of selected strains of Gluconobacter and Acetobacter.

PubMed

Sainz, F; Mas, A; Torija, M J

2017-02-02

Acetic acid bacteria (AAB) are a group of microorganisms highly used in the food industry. However, its use can be limited by the insufficient information known about the nutritional requirements of AAB for optimal growth. The aim of this work was to study the effects of different concentrations and sources of nitrogen on the growth of selected AAB strains and to establish which nitrogen source best encouraged their growth. Two strains of three species of AAB, Gluconobacter japonicus, Gluconobacter oxydans and Acetobacter malorum, were grown in three different media with diverse nitrogen concentrations (25, 50, 100, and 300mgN/L and 1gN/L) as a complete solution of amino acids and ammonium. With this experiment, the most favourable medium and the lowest nitrogen concentration beneficial for the growth of each strain was selected. Subsequently, under these conditions, single amino acids or ammonium were added to media individually to determine the best nitrogen sources for each AAB strain. The results showed that nitrogen requirements are highly dependent on the nitrogen source, the medium and the AAB strain. Gluconobacter strains were able to grow in the lowest nitrogen concentration tested (25mgN/L); however, one of the G. oxydans strains and both A. malorum strains required a higher concentration of nitrogen (100-300mgN/L) for optimal growth. In general, single nitrogen sources were not able to support the growth of these AAB strains as well as the complete solution of amino acids and ammonium. Copyright © 2016 Elsevier B.V. All rights reserved.

[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.

Screening of lactic acid bacteria from vacuum packaged beef for antimicrobial activity

PubMed Central

Oliveira, Roseane B. P.; de L. Oliveira, Afonso; Glória, M. Beatriz A.

2008-01-01

The objective of this study was to isolate lactic acid bacteria (LAB) from vacuum packaged beef and to investigate their antagonist activity. LAB mean counts of 5.19 log cfu/cm2 were obtained from five samples of vacuum packaged beef. Two hundred isolates were selected and screened for the inhibitory effect on five ATCC reference Lactobacillus strains. Thirty six isolates showed activity in the agar spot test against at least two of the indicator strains. However, only six cell free supernatants (CFS) from these isolates exhibited activity against the indicator strains using the well-diffusion test and conditions that eliminated the effects of organic acids and hydrogen peroxide. L. acidophilus was the most sensitive indicator tested, whereas L. plantarum and L. fermentum were the most resistant ones. Identification by MIDI system indicated that these LAB isolates were Lactococcus lactis subsp. cremoris, Pediococcus acidilactici, Lactobacillus delbrueckii subsp. bulgaricus and Lactobacillus casei GC subgroup A. The antagonistic factors produced by most of these LAB against L. acidophilus were resistant to heat treatment (100°C for 10 min) and stable over a wide pH range (4.0 to 9.0). These data suggest that these isolates could be used as promising hurdles aiming increased safety and extended shelf life of meat products. PMID:24031232

Formation of Guaiacol by Spoilage Bacteria from Vanillic Acid, a Product of Rice Koji Cultivation, in Japanese Sake Brewing.

PubMed

Ito, Toshihiko; Konno, Mahito; Shimura, Yoichiro; Watanabe, Seiei; Takahashi, Hitoshi; Hashizume, Katsumi

2016-06-08

The formation of guaiacol, a potent phenolic off-odor compound in the Japanese sake brewing process, was investigated. Eight rice koji samples were analyzed, and one contained guaiacol and 4-vinylguaiacol (4-VG) at extraordinarily high levels: 374 and 2433 μg/kg dry mass koji, respectively. All samples contained ferulic and vanillic acids at concentrations of mg/kg dry mass koji. Guaiacol forming microorganisms were isolated from four rice koji samples. They were identified as Bacillus subtilis, B. amyloliquefaciens/subtilis, and Staphylococcus gallinarum using 16S rRNA gene sequence. These spoilage bacteria convert vanillic acid to guaiacol and ferulic acid to 4-VG. However, they convert very little ferulic acid or 4-VG to guaiacol. Nine strains of koji fungi tested produced vanillic acid at the mg/kg dry mass koji level after cultivation. These results indicated that spoilage bacteria form guaiacol from vanillic acid, which is a product of koji cultivation in the sake brewing process.

Enhanced degradation of chlorpyrifos in rice (Oryza sativa L.) by five strains of endophytic bacteria and their plant growth promotional ability.

PubMed

Feng, Fayun; Ge, Jing; Li, Yisong; He, Shuang; Zhong, Jianfeng; Liu, Xianjing; Yu, Xiangyang

2017-10-01

Endophytic bacteria reside in plant tissues, such as roots, stems, leaves and seeds. Most of them can stimulate plant growth or alleviate phytotoxicity of pollutants. There are handful species with dual functions stimulating plant growth and degrading pollutants have been reported. Five endophytic bacteria were isolated from chlorpyrifos (CP) treated rice plants and identified as Pseudomonas aeruginosa strain RRA, Bacillus megaterium strain RRB, Sphingobacterium siyangensis strain RSA, Stenotrophomonas pavanii strain RSB and Curtobacterium plantarum strain RSC according to morphological characteristics, physiological and biochemical tests, and 16S rDNA phylogeny. All of them possessed some plant growth promotional traits, including indole acetic acid and siderophore production, secretion of phosphate solubilization and 1-aminocyclopropane-1-carboxylate deaminase. The bacteria were marked with the green fluorescent protein (gfp) gene and successfully colonized into rice plants. All isolates were able to degrade CP in vitro and in vivo. The five isolates degraded more than 90% of CP in 24 h when the initial concentration was lower than 5 mg/L. CP degradation was significantly enhanced in the infested rice plants and rice grains. The final CP residual was reduced up to 80% in the infested rice grains compared to the controls. The results indicate that these isolates are promising bio-inoculants for the removal or detoxification of CP residues in rice plants and grains. Copyright © 2017 Elsevier Ltd. All rights reserved.

Coaggregation between probiotic bacteria and caries-associated strains: an in vitro study.

PubMed

Twetman, Lisa; Larsen, Ulla; Fiehn, Nils-Erik; Stecksén-Blicks, Christina; Twetman, Svante

2009-01-01

To evaluate the in vitro abilities of probiotic bacteria derived from consumer products to coaggregate with caries-associated mutans streptococci. Six lactobacillus strains (L. acidophilus (CCUG 5917), L. plantarum 299v, L. rhamnosus GG and LB21, L. paracasei F19, L. reuteri PTA5289) were cultivated under anaerobic conditions at 37°C in Man Rogosa Sharpe (MSB) broth for 24 h. Four strains of human streptococci (S. mutans Ingbritt, S. mutans (ATCC 25175), S. mutans GS-5, S. sobrinus (ATCC 33478) were similarly grown in Brain Heart Infusion (BHI) broth. A gastrointestinal pathogen (Escherichia coli) was aerobically cultivated on BHI broth as a positive control. After incubation, the bacteria were aerobically harvested, washed, and suspended in 10 mmol/l phosphate-buffered saline (pH 7.2). The probiotic strains were characterized with the API 50 CH system to confirm their identity. Coaggregation was determined by spectrophotometry in mixtures and bacterial suspensions alone after 1, 2, 4, and 24 h and expressed as the aggregation ratio (%). All probiotic strains showed coaggregation abilities with the oral pathogens and the results were strain specific and dependent on time. S. mutans GS-5 exhibited a significantly higher ability to coaggregate with all the probiotic strains than the other mutans streptococci and E. coli. The differences among the probiotic strains were modest with L. acidophilus being the most prone and L. rhamnosus LB21 the least prone to coaggregate with the oral streptococci. The results demonstrated different abilities of lactobacilli-derived probiotic bacteria to coaggregate with selected oral streptococci. Aggregation assays may be a useful complement for screening of probiotic candidates with possible anti-caries properties.

Fermentation by amylolytic lactic acid bacteria and consequences for starch digestibility of plantain, breadfruit, and sweet potato flours.

PubMed

Haydersah, Julien; Chevallier, Isabelle; Rochette, Isabelle; Mouquet-Rivier, Claire; Picq, Christian; Marianne-Pépin, Thérèse; Icard-Vernière, Christèle; Guyot, Jean-Pierre

2012-08-01

The potential of tropical starchy plants such as plantain (Musa paradisiaca), breadfruit (Artocarpus communis), and sweet potato (Ipomoea batatas) for the development of new fermented foods was investigated by exploiting the capacity of some lactic acid bacteria to hydrolyze starch. The amylolytic lactic acid bacteria (ALAB) Lactobacillus plantarum A6 and Lactobacillus fermentum Ogi E1 were able to change the consistency of thick sticky gelatinized slurries of these starchy fruits and tubers into semiliquid to liquid products. Consequently, a decrease in apparent viscosity and an increase in Bostwick flow were observed. These changes and the production of maltooligosaccharides confirmed starch hydrolysis. Sucrose in sweet potato was not fermented by strain A6 and poorly fermented by strain Ogi E1, suggesting possible inhibition of sucrose fermentation. In all 3 starchy plants, rapidly digestible starch (RDS) was higher than slowly digestible starch (SDS) and resistant starch (RS) represented between 17% and 30% dry matter (DM). The digestibility of plantain was not affected by fermentation, whereas the RDS content of breadfruit and sweet potato decreased and the RS content increased after fermentation. The characteristics resulting from different combinations of gluten free starchy plants (plantain, breadfruit, sweet potato) and amylolytic lactic acid bacteria (ALAB) offer opportunities to develop new functional fermented beverages, mainly for breadfruit and sweet potato, after further investigation of their formulation, sensory attributes, nutritional, and prebiotic characteristics. Journal of Food Science © 2012 Institute of Food Technologists® No claim to original US government works.

Released products of pathogenic bacteria stimulate biofilm formation by Escherichia coli K-12 strains.

PubMed

Vacheva, Anna; Ivanova, Radka; Paunova-Krasteva, Tsvetelina; Stoitsova, Stoyanka

2012-06-01

It has recently been shown that pathogens with a limited capacity for sessile growth (like some Escherichia coli O157 strains) can benefit from the presence of other bacteria and form mixed biofilms with companion strains. This study addresses the question whether pathogens may influence attached growth of E. coli non-pathogenic strains via secreted factors. We compared the biofilm-modulating effects of sterile stationary-phase culture media of a biofilm non-producing strain of E. coli O157:H, a laboratory biofilm-producing E. coli K-12 strain and a biofilm-forming strain of the pathogen Yersina enterocolitica O:3. Sessile growth was monitored as biomass (crystal violet assay), exopolysaccharide (ELLA) and morphology (scanning electron and confocal laser microscopy). With two of the E. coli K-12 strains stimulation of biofilm formation by all supernatants was achieved, but only the pathogens' secreted products induced biomass increase in some 'biofilm-deficient' K-12 strains. Lectin-peroxidase labeling indicated changes in colanic acid and poly-N-acetylglucosamine amounts in extracellular matrices. The contribution of indole, protein and polysaccharide to the biofilm-modulating activities of the supernatants was compared. Indole, in concentrations equal to those established in the supernatants, suppressed sessile growth in one K-12 strain. Proteinase K significantly reduced the stimulatory effects of all supernatants, indicating a prominent role of protein/peptide factor(s) in biofilm promotion. The amount of released polysaccharides (rPS) in the supernatants was quantitated then comparable quantities of isolated rPS were applied during biofilm growth. The three rPS had notable strain-specific effects with regard to both the strain-source of the rPS and the E. coli K-12 target strain.

Genomics of lactic acid bacteria: Current status and potential applications.

PubMed

Wu, Chongde; Huang, Jun; Zhou, Rongqing

2017-08-01

Lactic acid bacteria (LAB) are widely used for the production of a variety of foods and feed raw materials where they contribute to flavor and texture of the fermented products. In addition, specific LAB strains are considered as probiotic due to their health-promoting effects in consumers. Recently, the genome sequencing of LAB is booming and the increased amount of published genomics data brings unprecedented opportunity for us to reveal the important traits of LAB. This review describes the recent progress on LAB genomics and special emphasis is placed on understanding the industry-related physiological features based on genomics analysis. Moreover, strategies to engineer metabolic capacity and stress tolerance of LAB with improved industrial performance are also discussed.

Importance of lactic acid bacteria in Asian fermented foods

PubMed Central

2011-01-01

Lactic acid bacteria play important roles in various fermented foods in Asia. Besides being the main component in kimchi and other fermented foods, they are used to preserve edible food materials through fermentation of other raw-materials such as rice wine/beer, rice cakes, and fish by producing organic acids to control putrefactive microorganisms and pathogens. These bacteria also provide a selective environment favoring fermentative microorganisms and produce desirable flavors in various fermented foods. This paper discusses the role of lactic acid bacteria in various non-dairy fermented food products in Asia and their nutritional and physiological functions in the Asian diet. PMID:21995342

Phenotypic and genetic evaluations of biogenic amine production by lactic acid bacteria isolated from fish and fish products.

PubMed

Muñoz-Atienza, Estefanía; Landeta, Gerardo; de las Rivas, Blanca; Gómez-Sala, Beatriz; Muñoz, Rosario; Hernández, Pablo E; Cintas, Luis M; Herranz, Carmen

2011-03-30

In this work, biogenic amine production (histamine, tyramine and putrescine) by a collection of 74 lactic acid bacteria of aquatic origin has been investigated by means of amino acid decarboxylation by growth on decarboxylase differential medium, biogenic amine detection by thin-layer chromatography (TLC) and decarboxylase gene detection by PCR. None of the evaluated strains showed neither production of histamine and putrescine, nor presence of the genetic determinants encoding the corresponding decarboxylase activities. However, the tyrosine decarboxylase gene (tdc) was present in all the enterococcal strains, and tyramine production was detected by TLC in all of them but Enterococcus faecium BCS59 and MV5. Analysis of the tyrosine decarboxylase operon of these strains revealed the presence of an insertion sequence upstream tdc that could be responsible for their lack of tyrosine decarboxylase activity. Copyright © 2011 Elsevier B.V. All rights reserved.

Lactobacillus kefiri shows inter-strain variations in the amino acid sequence of the S-layer proteins.

PubMed

Malamud, Mariano; Carasi, Paula; Bronsoms, Sílvia; Trejo, Sebastián A; Serradell, María de Los Angeles

2017-04-01

The S-layer is a proteinaceous envelope constituted by subunits that self-assemble to form a two-dimensional lattice that covers the surface of different species of Bacteria and Archaea, and it could be involved in cell recognition of microbes among other several distinct functions. In this work, both proteomic and genomic approaches were used to gain knowledge about the sequences of the S-layer protein (SLPs) encoding genes expressed by six aggregative and sixteen non-aggregative strains of potentially probiotic Lactobacillus kefiri. Peptide mass fingerprint (PMF) analysis confirmed the identity of SLPs extracted from L. kefiri, and based on the homology with phylogenetically related species, primers located outside and inside the SLP-genes were employed to amplify genomic DNA. The O-glycosylation site SASSAS was found in all L. kefiri SLPs. Ten strains were selected for sequencing of the complete genes. The total length of the mature proteins varies from 492 to 576 amino acids, and all SLPs have a calculated pI between 9.37 and 9.60. The N-terminal region is relatively conserved and shows a high percentage of positively charged amino acids. Major differences among strains are found in the C-terminal region. Different groups could be distinguished regarding the mature SLPs and the similarities observed in the PMF spectra. Interestingly, SLPs of the aggregative strains are 100% homologous, although these strains were isolated from different kefir grains. This knowledge provides relevant data for better understanding of the mechanisms involved in SLPs functionality and could contribute to the development of products of biotechnological interest from potentially probiotic bacteria.

Novel bacteriocins from lactic acid bacteria (LAB): various structures and applications

PubMed Central

2014-01-01

Bacteriocins are heat-stable ribosomally synthesized antimicrobial peptides produced by various bacteria, including food-grade lactic acid bacteria (LAB). These antimicrobial peptides have huge potential as both food preservatives, and as next-generation antibiotics targeting the multiple-drug resistant pathogens. The increasing number of reports of new bacteriocins with unique properties indicates that there is still a lot to learn about this family of peptide antibiotics. In this review, we highlight our system of fast tracking the discovery of novel bacteriocins, belonging to different classes, and isolated from various sources. This system employs molecular mass analysis of supernatant from the candidate strain, coupled with a statistical analysis of their antimicrobial spectra that can even discriminate novel variants of known bacteriocins. This review also discusses current updates regarding the structural characterization, mode of antimicrobial action, and biosynthetic mechanisms of various novel bacteriocins. Future perspectives and potential applications of these novel bacteriocins are also discussed. PMID:25186038

Novel bacteriocins from lactic acid bacteria (LAB): various structures and applications.

PubMed

Perez, Rodney H; Zendo, Takeshi; Sonomoto, Kenji

2014-08-29

Bacteriocins are heat-stable ribosomally synthesized antimicrobial peptides produced by various bacteria, including food-grade lactic acid bacteria (LAB). These antimicrobial peptides have huge potential as both food preservatives, and as next-generation antibiotics targeting the multiple-drug resistant pathogens. The increasing number of reports of new bacteriocins with unique properties indicates that there is still a lot to learn about this family of peptide antibiotics. In this review, we highlight our system of fast tracking the discovery of novel bacteriocins, belonging to different classes, and isolated from various sources. This system employs molecular mass analysis of supernatant from the candidate strain, coupled with a statistical analysis of their antimicrobial spectra that can even discriminate novel variants of known bacteriocins. This review also discusses current updates regarding the structural characterization, mode of antimicrobial action, and biosynthetic mechanisms of various novel bacteriocins. Future perspectives and potential applications of these novel bacteriocins are also discussed.

Antigenotoxic activity of lactic acid bacteria, prebiotics, and products of their fermentation against selected mutagens.

PubMed

Nowak, Adriana; Śliżewska, Katarzyna; Otlewska, Anna

2015-12-01

Dietary components such as lactic acid bacteria (LAB) and prebiotics can modulate the intestinal microbiota and are thought to be involved in the reduction of colorectal cancer risk. The presented study measured, using the comet assay, the antigenotoxic activity of both probiotic and non-probiotic LAB, as well as some prebiotics and the end-products of their fermentation, against fecal water (FW). The production of short chain fatty acids by the bacteria was quantified using HPLC. Seven out of the ten tested viable strains significantly decreased DNA damage induced by FW. The most effective of them were Lactobacillus mucosae 0988 and Bifidobacterium animalis ssp. lactis Bb-12, leading to a 76% and 80% decrease in genotoxicity, respectively. The end-products of fermentation of seven prebiotics by Lactobacillus casei DN 114-001 exhibited the strongest antigenotoxic activity against FW, with fermented inulin reducing genotoxicity by 75%. Among the tested bacteria, this strain produced the highest amounts of butyrate in the process of prebiotic fermentation, and especially from resistant dextrin (4.09 μM/mL). Fermented resistant dextrin improved DNA repair by 78% in cells pre-treated with 6.8 μM methylnitronitrosoguanidine (MNNG). Fermented inulin induced stronger DNA repair in cells pre-treated with mutagens (FW, 25 μM hydrogen peroxide, or MNNG) than non-fermented inulin, and the efficiency of DNA repair after 120 min of incubation decreased by 71%, 50% and 70%, respectively. The different degrees of genotoxicity inhibition observed for the various combinations of bacteria and prebiotics suggest that this effect may be attributable to carbohydrate type, SCFA yield, and the ratio of the end-products of prebiotic fermentation. Copyright © 2015 Elsevier Inc. All rights reserved.

Unifying bacteria from decaying wood with various ubiquitous Gibbsiella species as G. acetica sp. nov. based on nucleotide sequence similarities and their acetic acid secretion.

PubMed

Geider, Klaus; Gernold, Marina; Jock, Susanne; Wensing, Annette; Völksch, Beate; Gross, Jürgen; Spiteller, Dieter

2015-12-01

Bacteria were isolated from necrotic apple and pear tree tissue and from dead wood in Germany and Austria as well as from pear tree exudate in China. They were selected for growth at 37 °C, screened for levan production and then characterized as Gram-negative, facultatively anaerobic rods. Nucleotide sequences from 16S rRNA genes, the housekeeping genes dnaJ, gyrB, recA and rpoB alignments, BLAST searches and phenotypic data confirmed by MALDI-TOF analysis showed that these bacteria belong to the genus Gibbsiella and resembled strains isolated from diseased oaks in Britain and Spain. Gibbsiella-specific PCR primers were designed from the proline isomerase and the levansucrase genes. Acid secretion was investigated by screening for halo formation on calcium carbonate agar and the compound identified by NMR as acetic acid. Its production by Gibbsiella spp. strains was also determined in culture supernatants by GC/MS analysis after derivatization with pentafluorobenzyl bromide. Some strains were differentiated by the PFGE patterns of SpeI digests and by sequence analyses of the lsc and the ppiD genes, and the Chinese Gibbsiella strain was most divergent. The newly investigated bacteria as well as Gibbsiella querinecans, Gibbsiella dentisursi and Gibbsiella papilionis, isolated in Britain, Spain, Korea and Japan, are taxonomically related Enterobacteriaceae, tolerate and secrete acetic acid. We therefore propose to unify them in the species Gibbsiella acetica sp. nov. Copyright © 2015. Published by Elsevier GmbH.

Humic Acid Reduction by Propionibacterium freudenreichii and Other Fermenting Bacteria

PubMed Central

Benz, Marcus; Schink, Bernhard; Brune, Andreas

1998-01-01

Iron-reducing bacteria have been reported to reduce humic acids and low-molecular-weight quinones with electrons from acetate or hydrogen oxidation. Due to the rapid chemical reaction of amorphous ferric iron with the reduced reaction products, humic acids and low-molecular-weight redox mediators may play an important role in biological iron reduction. Since many anaerobic bacteria that are not able to reduce amorphous ferric iron directly are known to transfer electrons to other external acceptors, such as ferricyanide, 2,6-anthraquinone disulfonate (AQDS), or molecular oxygen, we tested several physiologically different species of fermenting bacteria to determine their abilities to reduce humic acids. Propionibacterium freudenreichii, Lactococcus lactis, and Enterococcus cecorum all shifted their fermentation patterns towards more oxidized products when humic acids were present; P. freudenreichii even oxidized propionate to acetate under these conditions. When amorphous ferric iron was added to reoxidize the electron acceptor, humic acids were found to be equally effective when they were added in substoichiometric amounts. These findings indicate that in addition to iron-reducing bacteria, fermenting bacteria are also capable of channeling electrons from anaerobic oxidations via humic acids towards iron reduction. This information needs to be considered in future studies of electron flow in soils and sediments. PMID:9797315

Synergistic Antibacterial Effects of Chitosan-Caffeic Acid Conjugate against Antibiotic-Resistant Acne-Related Bacteria.

PubMed

Kim, Ji-Hoon; Yu, Daeung; Eom, Sung-Hwan; Kim, Song-Hee; Oh, Junghwan; Jung, Won-Kyo; Kim, Young-Mog

2017-06-08

The object of this study was to discover an alternative therapeutic agent with fewer side effects against acne vulgaris, one of the most common skin diseases. Acne vulgaris is often associated with acne-related bacteria such as Propionibacterium acnes , Staphylococcus epidermidis , Staphylococcus aureus , and Pseudomonas aeruginosa . Some of these bacteria exhibit a resistance against commercial antibiotics that have been used in the treatment of acne vulgaris (tetracycline, erythromycin, and lincomycin). In the current study, we tested in vitro antibacterial effect of chitosan-phytochemical conjugates on acne-related bacteria. Three chitosan-phytochemical conjugates used in this study exhibited stronger antibacterial activity than that of chitosan (unmodified control). Chitosan-caffeic acid conjugate (CCA) showed the highest antibacterial effect on acne-related bacteria along with minimum inhibitory concentration (MIC; 8 to 256 μg/mL). Additionally, the MIC values of antibiotics against antibiotic-resistant P. acnes and P. aeruginosa strains were dramatically reduced in combination with CCA, suggesting that CCA would restore the antibacterial activity of the antibiotics. The analysis of fractional inhibitory concentration (FIC) indices clearly revealed a synergistic antibacterial effect of CCA with antibiotics. Thus, the median sum of FIC (∑FIC) values against the antibiotic-resistant bacterial strains ranged from 0.375 to 0.533 in the combination mode of CCA and antibiotics. The results of the present study suggested a potential possibility of chitosan-phytochemical conjugates in the control of infections related to acne vulgaris.

Sourdough lactic acid bacteria: exploration of non-wheat cereal-based fermentation.

PubMed

Coda, Rossana; Cagno, Raffaella Di; Gobbetti, Marco; Rizzello, Carlo Giuseppe

2014-02-01

Cereal-based foods represent a very important source of biological as well as of cultural diversity, as testified by the wide range of derived fermented products. A trend that is increasingly attracting bakery industries as well as consumers is the use of non-conventional flours for the production of novel products, characterised by peculiar flavour and better nutritional value. Lactic acid bacteria microbiota of several non-wheat cereals and pseudo-cereals has been recently deeply investigated with the aim of studying the biodiversity and finding starter cultures for sourdough fermentation. Currently, the use of ancient or ethnic grains is mainly limited to traditional typical foods and the bread making process is not well standardised with consequent negative effects on the final properties. The challenge in fermenting such grains is represented by the necessity to combine good technology and sensory properties with nutritional/health benefits. The choice of the starter cultures has a critical impact on the final quality of cereal-based products, and strains that dominate and outcompete contaminants should be applied for specific sourdough fermentations. In this sense, screening and characterisation of the lactic acid bacteria microbiota is very useful in the improvement of a peculiar flour, from both a nutritional and technological point of view. Copyright © 2013 Elsevier Ltd. All rights reserved.

Production of biogenic amines by lactic acid bacteria and enterobacteria isolated from fresh pork sausages packaged in different atmospheres and kept under refrigeration.

PubMed

Curiel, J A; Ruiz-Capillas, C; de Las Rivas, B; Carrascosa, A V; Jiménez-Colmenero, F; Muñoz, R

2011-07-01

The occurrence of in vitro amino acid activity in bacterial strains associated with fresh pork sausages packaged in different atmospheres and kept in refrigeration was studied. The presence of biogenic amines in decarboxylase broth was confirmed by ion-exchange chromatography and by the presence of the corresponding decarboxylase genes by PCR. From the 93 lactic acid bacteria and 100 enterobacteria strains analysed, the decarboxylase medium underestimates the number of biogenic amine-producer strains. 28% of the lactic acid bacteria produced tyramine and presented the tdc gene. All the tyramine-producer strains were molecularly identified as Carnobacterium divergens. Differences on the relative abundance of C. divergens were observed among the different packaging atmospheres assayed. After 28 days of storage, the presence of argon seems to inhibit C. divergens growth, while packing under vacuum seems to favour it. Among enterobacteria, putrescine was the amine more frequently produced (87%), followed by cadaverine (85%); agmatine and tyramine were only produced by 13 and 1%, respectively, of the strains analysed. Packing under vacuum or in an atmosphere containing nitrogen seems to inhibit the growth of enterobacteria which produce simultaneously putrescine, cadaverine, and agmatine. Contrarily, over-wrapping or packing in an atmosphere containing argon seems to favour the growth of agmatine producer-enterobacteria. The production of putrescine and cadaverine was associated with the presence of the corresponding amino acid decarboxylase genes. The biogenic amine-producer strains were included in a wide range of enterobacterial species, including Kluyvera intermedia, Enterobacter aerogenes, Yersinia kristensenii, Serratia grimesii, Serratia ficaria, Yersinia rodhei, Providencia vermicola and Obesumbacterium proteus. Copyright © 2011 Elsevier Ltd. All rights reserved.

Codominance of Lactobacillus plantarum and obligate heterofermentative lactic acid bacteria during sourdough fermentation.

PubMed

Ventimiglia, Giusi; Alfonzo, Antonio; Galluzzo, Paola; Corona, Onofrio; Francesca, Nicola; Caracappa, Santo; Moschetti, Giancarlo; Settanni, Luca

2015-10-01

Fifteen sourdoughs produced in western Sicily (southern Italy) were analysed by classical methods for their chemico-physical characteristics and the levels of lactic acid bacteria (LAB). pH and total titratable acidity (TTA) were mostly in the range commonly reported for similar products produced in Italy, but the fermentation quotient (FQ) of the majority of samples was above 4.0, due to the low concentration of acetic acid estimated by high performance liquid chromatography (HPLC). Specific counts of LAB showed levels higher than 10(8) CFU g(-1) for many samples. The colonies representing various morphologies were isolated and, after the differentiation based on phenotypic characteristics, divided into 10 groups. The most numerous group was composed of facultative heterofermentative isolates, indicating a relevance of this bacterial group during fermentation. The genetic analysis by randomly amplified polymorphic DNA (RAPD)-PCR, 16S rRNA gene sequencing and species-specific PCRs identified 33 strains as Lactobacillus plantarum, Lactobacillus curvatus and Lactobacillus graminis. Due to the consistent presence of L. plantarum, it was concluded that this species codominates with obligate heterofermentative LAB in sourdough production in this geographical area. In order to evaluate the performances at the basis of their fitness, the 29 L. plantarum strains were investigated for several technological traits. Twelve cultures showed good acidifying abilities in vitro and L. plantarum PON100148 produced the highest concentrations of organic acids. Eleven strains were positive for extracellular protease activity. Bacteriocin-like inhibitory substances (BLIS) production and antifungal activity was scored positive for several strains, included L. plantarum PON100148 which was selected as starter for experimental sourdough production. The characteristics of the sourdoughs and the resulting breads indicated that the best productions were obtained in presence of L

[Composition diversity of lactic acid bacteria (LAB) community Al2 used for alfalfa silage].

PubMed

Wang, Xiao-Fen; Gao, Li-Juan; Yang, Hong-Yan; Wang, Wei-Dong; Cui, Zong-Jun

2006-10-01

Alfalfa is the most important forage grass that is difficult to ensile for good quality. Using silage inoculants are the important way for preservation of alfalfa silage. Through continuous restricted subcultivation, a lactic acid bacteria (LAB) community Al2 was selected from well-fermented alfalfa silage. Plate isolation and Denaturing Gradient Gel Electrophoresis (DGGE), construction of 16S rDNA clone library were used to identify the composition diversity of Al2 community, with 7 strains detected, and they were all belonged to Lactobacillus. The composition ratios of the 7 strains were 55.21%, 19.79%, 14.58%, 3.13%, 3.13%, 3.13%, 1.03% according to 16S rDNA clone library. Al2-1i, Al2-2i, Al2-3i, corresponding to L. plantarum (99.9%), L. kimchii (99.4%), L. farciminis (100%) were detected by plate isolation. Among 3 isolates, Al2-1i had the highest ability of dropping pH and producing lactic acid, and the amount of lactic acid was reach to 18g/L at 24h cultivated in MRS media. The ability of dropping pH and producing lactic acid of Al2-3i was the lowest. From DGGE profiles, the dominant strains in Al2 community were L. plantarum and L. kimchii. L. plantarum was detected during the whole process, and L. kimchii was detected in the later phase.

Exploitation of grape marc as functional substrate for lactic acid bacteria and bifidobacteria growth and enhanced antioxidant activity.

PubMed

Campanella, Daniela; Rizzello, Carlo Giuseppe; Fasciano, Cristina; Gambacorta, Giuseppe; Pinto, Daniela; Marzani, Barbara; Scarano, Nicola; De Angelis, Maria; Gobbetti, Marco

2017-08-01

This study aimed at using grape marc for the growth of lactic acid bacteria and bifidobacteria with the perspective of producing a functional ingredient having antioxidant activity. Lactobacillus plantarum 12A and PU1, Lactobacillus paracasei 14A, and Bifidobacterium breve 15A showed the ability to grow on grape marc (GM) based media. The highest bacterial cell density (>9.0 CFU/g) was found in GM added of 1% of glucose (GMG). Compared to un-inoculated and incubated control fermented GMG showed a decrease of carbohydrates and citric acid together with an increase of lactic acid. The content of several free amino acids and phenol compounds differed between samples. Based on the survival under simulated gastro-intestinal conditions, GMG was a suitable carrier of lactic acid bacteria and bifidobacteria strains. Compared to the control, cell-free supernatant (CFS) of fermented GMG exhibited a marked antioxidant activity in vitro. The increased antioxidant activity was confirmed using Caco-2 cell line after inducing oxidative stress, and determining cell viability and radical scavenging activity through MTT and DCFH-DA assays, respectively. Supporting these founding, the SOD-2 gene expression of Caco-2 cells also showed a lowest pro-oxidant effect induced by the four CFS of GMG fermented by lactic acid bacteria and bifidobacteria. Copyright © 2017 Elsevier Ltd. All rights reserved.

Bee Venom (Apis Mellifera) an Effective Potential Alternative to Gentamicin for Specific Bacteria Strains: Bee Venom an Effective Potential for Bacteria.

PubMed

Zolfagharian, Hossein; Mohajeri, Mohammad; Babaie, Mahdi

2016-09-01

Mellitine, a major component of bee venom (BV, Apis mellifera ), is more active against gram positive than gram negative bacteria. Moreover, BV has been reported to have multiple effects, including antibacterial, antivirus, and anti-inflammation effects, in various types of cells. In addition, wasp venom has been reported to have antibacterial properties. The aim of this study was to evaluate the antibacterial activity of BV against selected gram positive and gram negative bacterial strains of medical importance. This investigation was set up to evaluate the antibacterial activity of BV against six grams positive and gram negative bacteria, including Staphylococcus aureus ( S. aureus ), Salmonella typhimurium , Escherichia coli ( E. coli ) O157:H7, Pseudomonas aeruginosa , Burkholderia mallei and Burkholderia pseudomallei. Three concentrations of crude BV and standard antibiotic (gentamicin) disks as positive controls were tested by using the disc diffusion method. BV was found to have a significant antibacterial effect against E. coli , S. aureus , and Salmonella typhyimurium in all three concentrations tested. However, BV had no noticeable effect on other tested bacteria for any of the three doses tested. The results of the current study indicate that BV inhibits the growth and survival of bacterial strains and that BV can be used as a complementary antimicrobial agent against pathogenic bacteria. BV lacked the effective proteins necessary for it to exhibit antibacterial activity for some specific strains while being very effective against other specific strains. Thus, one may conclude, that Apis mellifera venom may have a specific mechanism that allows it to have an antibacterial effect on certain susceptible bacteria, but that mechanism is not well understood.

Review - Lactic acid bacteria in traditional fermented Asian foods.

PubMed

Azam, Mariya; Mohsin, Mashkoor; Ijaz, Hira; Tulain, Ume Ruqia; Ashraf, Muhammad Adnan; Fayyaz, Ahad; Abadeen, Zainul; Kamran, Qindeel

2017-09-01

Lactic acid bacteria play vital roles in various fermented foods in Asia. This paper reviews many types of the world's lactic acid fermented foods and discusses the beneficial effects of lactic acid fermentation of food. The lactic acid bacteria associated with foods now include species of the genera Carnobacterium, Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Oenococcus, Pediococcus, Streptococcus, Tetragenococcus, Vagococcus and Weissella. Lactic acid bacteria (LAB) are involved in many fermentation processes of Asian traditional foods, demonstrating their profound effects on improving food quality and food safety. During the past few decades' interest has arisen in the use of the varied antagonistic activities of LAB to extent the shelf-life of protein-rich products such as meats and fish. This review article outlines the main types of LAB fermentation as well as their typical fermented foods such as idli, kishk, sauerkraut, koumiss, Suan-tsai, stinky tofu, Chinese sausage and kefir. The roles of LAB and the reasons for their common presence are also discussed.

Identification and partial characterization of lactic acid bacteria isolated from traditional dairy products produced by herders in the western Tianshan Mountains of China.

PubMed

Zuo, F L; Feng, X J; Chen, L L; Chen, S W

2014-11-01

Thirty strains of lactic acid bacteria (LAB) were isolated from herders' traditional dairy products collected from Xinjiang, China. The species Lactobacillus, Lactococcus, Enterococcus, Pediococcus and Leuconostoc were identified by 16S ribosomal RNA gene sequencing analysis and conventional observation. The strains' fermentation characteristics, including milk acidification, proteolysis, autolysis, antimicrobial activity and diacetyl production, were assayed and compared. Strains NL24 and NL31 showed the highest proteolytic activity-2·75 and 2·08 mmol Phe l(-1) milk, respectively. Strains C, NL41, SW2, Z3-11, NL42 and Z2-91 had high autolytic activity. In addition, most of the wild strains produced diacetyl, half of them to high levels. This study provides a clue to LAB biodiversity in traditional dairy foods produced by herders in the western Tianshan Mountains. High-performing strains should be further evaluated for practical application in value-added fermented dairy products. Our results reveal a certain variety of lactic acid bacteria (LAB) in traditional dairy products from Xinjiang. Some of the LAB strains, such as Lactobacillus rhamnosus NL24 and Lactobacillus paracasei SW2, possess excellent functional properties and have the potential for application in indigenous fermented dairy products. Performance of the newly isolated strains in cheese or yogurt manufacturing was further evaluated. Application of the high-performing strains to enrich the flavour of fermented dairy products is highly desirable and holds great commercial potential. © 2014 The Society for Applied Microbiology.

The anti-allergic effects of lactic acid bacteria are strain dependent and mediated by effects on both Th1/Th2 cytokine expression and balance.

PubMed

Fujiwara, Daisuke; Inoue, Sayo; Wakabayashi, Hideyuki; Fujii, Toshio

2004-11-01

There is growing interest in the immune-stimulating effect and in particular, the anti-allergic effect, of lactic acid bacteria (LAB). However, no comprehensive studies have been done that compare the immune-stimulating potential of LAB strains. The in vitro immune-stimulating effects on Th1/Th2 balance of more than 100 LAB strains were compared in splenocytes from ovalbumin-sensitized Th2-polarized mice. The in vivo anti-allergic ability of strain KW3110 was studied in the Th2-polarized model by detecting serum IgE concentration, Th1/Th2 cytokine secretion from splenocytes, and the expression of co-stimulatory molecules on macrophages. In vitro studies from Th2-polarized splenocytes, using IL-12 as a Th1 parameter and IL-4 secretion as a Th2 parameter revealed a wide variety of IL-12-inducing and IL-4-repressing activities, depending on the strain of LAB, not depending on the species. However, evaluation of individual strains in vivo revealed that after exposure to Lactobacillus paracasei KW3110 strain, the serum IgE elevation elicited by repeated OVA injection of mice was strongly inhibited. Cytokine secretion from splenocytes 20 weeks after KW3110 administration showed increased IL-12 and decreased IL-4 expression. Both CD40 and B7-1 expression on macrophages was upregulated by administration of KW3110. Improving the consequences of the Th1/Th2 imbalance by administration of LAB was dependent upon the LAB strain rather than the LAB species. Oral KW3110 administration in the mouse allergy model directed the Th1/Th2 balance toward Th1 through the maturation of APCs and inhibition of serum IgE elevation.

Fermentation of aqueous plant seed extracts by lactic acid bacteria

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

Schafner, D.W.; Beuchat, R.L.

1986-05-01

The effects of lactic acid bacterial fermentation on chemical and physical changes in aqueous extracts of cowpea (Vigna unguiculata), peanut (Arachis hypogea), soybean (Glycine max), and sorghum (Sorghum vulgare) were studied. The bacteria investigated were Lactobacillus helveticus, L. delbrueckii, L. casei, L. bulgaricus, L. acidophilus, and Streptococcus thermophilus. Organisms were inoculated individually into all of the seed extracts; L. bulgaricus and S. thermophilus were also evaluated together as inocula for fermenting the legume extracts. During fermentation, bacterial population and changes in titratable acidity, pH, viscosity, and color were measured over a 72 h period at 37 degrees C. Maximum bacterialmore » populations, titratable acidity, pH, and viscosity varied depending upon the type of extract and bacterial strain. The maximum population of each organism was influenced by fermentable carbohydrates, which, in turn, influenced acid production and change in pH. Change in viscosity was correlated with the amount of protein and titratable acidity of products. Color was affected by pasteurization treatment and fermentation as well as the source of extract. In the extracts inoculated simultaneously with L. bulgaricus and S. thermophilus, a synergistic effect resulted in increased bacterial populations, titratable acidity, and viscosity, and decreased pH in all the legume extracts when compared to the extracts fermented with either of these organisms individually. Fermented extracts offer potential as substitutes for cultured dairy products. 24 references.« less

Biodegradation of the xenobiotic organic disulphide 4,4'-dithiodibutyric acid by Rhodococcus erythropolis strain MI2 and comparison with the microbial utilization of 3,3'-dithiodipropionic acid and 3,3'-thiodipropionic acid.

PubMed

Wübbeler, Jan Hendrik; Bruland, Nadine; Wozniczka, Milena; Steinbüchel, Alexander

2010-04-01

Application of the non-toxic 3,3'-thiodipropionic acid (TDP) and 3,3'-dithiodipropionic acid (DTDP) as precursors for the microbial production of polythioesters (PTEs), a class of biologically persistent biopolymers containing sulphur in the backbone, was successfully established previously. However, synthesis of PTEs containing 4-mercaptobutyrate (4MB) as building blocks could not be achieved. The very harmful 4MB is not used as a PTE precursor or as the carbon source for growth by any known strain. As a promising alternative, the harmless oxidized disulfide of two molecules of 4MB, 4,4'-dithiodibutyric acid (DTDB), was employed for enrichments of bacterial strains capable of biodegradation. Investigation of novel precursor substrates for PTEs and comparison of respective strains growing on TDP, DTDP and DTDB as sole carbon source was accomplished. A broad variety of bacteria capable of using one of these organic sulphur compounds were isolated and compared. TDP and DTDP were degraded by several strains belonging to different genera, whereas all DTDB-utilizing strains were affiliated to the species Rhodococcus erythropolis. Transposon mutagenesis of R. erythropolis strain MI2 and screening of 7500 resulting mutants yielded three mutants exhibiting impaired growth on DTDB. Physiological studies revealed production of volatile hydrogen sulphide and accumulation of significant amounts of 4MB, 4-oxo-4-sulphanylbutanoic acid and succinic acid in the culture supernatants. Based on this knowledge, a putative pathway for degradation of DTDB was proposed: DTDB could be cleaved into two molecules of 4MB, followed by an oxidation yielding 4-oxo-4-sulphanylbutanoic acid. A putative desulphydrase probably catalyses the abstraction of sulphur, thereby generating succinic acid and hydrogen sulphide.

Use of Selected Lactic Acid Bacteria and Quinoa Flour for Manufacturing Novel Yogurt-Like Beverages.

PubMed

Lorusso, Anna; Coda, Rossana; Montemurro, Marco; Rizzello, Carlo Giuseppe

2018-04-01

This study aimed at investigating the suitability of quinoa for making yogurt-like beverages. After the selection of the adequate technological parameters, the fermentation was carried out by using different lactic acid bacteria strains: a probiotic ( Lactobacillus rhamnosus SP1), an exopolysaccharides (EPS)-producing ( Weissella confusa DSM 20194), and one isolated from quinoa ( Lactobacillus plantarum T6B10). During the 20 h of fermentation, W. confusa caused the highest viscosity increase. All the strains had improved concentration of free amino acids and γ-Aminobutyric acid (GABA), polyphenols availability, antioxidant activity (up to 54%), and protein digestibility. The nutritional index (NI) was the highest when L. rhamnosus SP1 was used. The starch hydrolysis index in vitro ranged from 52 to 60. During storage at 4 °C, viscosity and water holding capacity decreased with the exception of the beverage fermented with W. confusa , while all the nutritional characteristics remained stable or slightly increased. Sensory analyses showed that beverages had good textural and organoleptic profiles. Besides the well-known positive properties of the raw matrix, fermentation allowed the obtainment of beverages with different features. Due to the nutritional and functional characteristics conferred to the quinoa beverages, the use of the probiotic and EPS-producing strains showed adequate potential for the industrial application.

Use of Selected Lactic Acid Bacteria and Quinoa Flour for Manufacturing Novel Yogurt-Like Beverages

PubMed Central

Lorusso, Anna; Montemurro, Marco; Rizzello, Carlo Giuseppe

2018-01-01

This study aimed at investigating the suitability of quinoa for making yogurt-like beverages. After the selection of the adequate technological parameters, the fermentation was carried out by using different lactic acid bacteria strains: a probiotic (Lactobacillus rhamnosus SP1), an exopolysaccharides (EPS)-producing (Weissella confusa DSM 20194), and one isolated from quinoa (Lactobacillus plantarum T6B10). During the 20 h of fermentation, W. confusa caused the highest viscosity increase. All the strains had improved concentration of free amino acids and γ-Aminobutyric acid (GABA), polyphenols availability, antioxidant activity (up to 54%), and protein digestibility. The nutritional index (NI) was the highest when L. rhamnosus SP1 was used. The starch hydrolysis index in vitro ranged from 52 to 60. During storage at 4 °C, viscosity and water holding capacity decreased with the exception of the beverage fermented with W. confusa, while all the nutritional characteristics remained stable or slightly increased. Sensory analyses showed that beverages had good textural and organoleptic profiles. Besides the well-known positive properties of the raw matrix, fermentation allowed the obtainment of beverages with different features. Due to the nutritional and functional characteristics conferred to the quinoa beverages, the use of the probiotic and EPS-producing strains showed adequate potential for the industrial application. PMID:29614769

Inhibition of Staphylococcus aureus by crude and fractionated extract from lactic acid bacteria.

PubMed

Wong, C-B; Khoo, B-Y; Sasidharan, S; Piyawattanametha, W; Kim, S H; Khemthongcharoen, N; Ang, M-Y; Chuah, L-O; Liong, M-T

2015-03-01

Increasing levels of antibiotic resistance by Staphylococcus aureus have posed a need to search for non-antibiotic alternatives. This study aimed to assess the inhibitory effects of crude and fractionated cell-free supernatants (CFS) of locally isolated lactic acid bacteria (LAB) against a clinical strain of S. aureus. A total of 42 LAB strains were isolated and identified from fresh vegetables, fresh fruits and fermented products prior to evaluation of inhibitory activities. CFS of LAB strains exhibiting a stronger inhibitive effect against S. aureus were fractionated into crude protein, polysaccharide and lipid fractions. Crude protein fractions showed greater inhibition against S. aureus compared to polysaccharide and lipid fractions, with a more prevalent effect from Lactobacillus plantarum 8513 and L. plantarum BT8513. Crude protein, polysaccharide and lipid fractions were also characterised with glycine, mannose and oleic acid being detected as the major component of each fraction, respectively. Scanning electron microscopy revealed roughed and wrinkled membrane morphology of S. aureus upon treatment with crude protein fractions of LAB, suggesting an inhibitory effect via the destruction of cellular membrane. This research illustrated the potential application of fractionated extracts from LAB to inhibit S. aureus for use in the food and health industry.

Genetic and technological characterisation of vineyard- and winery-associated lactic acid bacteria.

PubMed

Nisiotou, Aspasia A; Dourou, Dimitra; Filippousi, Maria-Evangelia; Diamantea, Ellie; Fragkoulis, Petros; Tassou, Chryssoula; Banilas, Georgios

2015-01-01

Vineyard- and winery-associated lactic acid bacteria (LAB) from two major PDO regions in Greece, Peza and Nemea, were surveyed. LAB were isolated from grapes, fermenting musts, and winery tanks performing spontaneous malolactic fermentations (MLF). Higher population density and species richness were detected in Nemea than in Peza vineyards and on grapes than in fermenting musts. Pediococcus pentosaceus and Lactobacillus graminis were the most abundant LAB on grapes, while Lactobacillus plantarum dominated in fermenting musts from both regions. No particular structure of Lactobacillus plantarum populations according to the region of origin was observed, and strain distribution seems random. LAB species diversity in winery tanks differed significantly from that in vineyard samples, consisting principally of Oenococcus oeni. Different strains were analysed as per their enological characteristics and the ability to produce biogenic amines (BAs). Winery-associated species showed higher resistance to low pH, ethanol, SO2, and CuSO4 than vineyard-associated isolates. The frequency of BA-producing strains was relatively low but not negligible, considering that certain winery-associated Lactobacillus hilgardii strains were able to produce BAs. Present results show the necessity of controlling the MLF by selected starters in order to avoid BA accumulation in wine.

Characterization of lactic acid bacteria from local cow´s milk kefir

NASA Astrophysics Data System (ADS)

Ismail, YS; Yulvizar, C.; Mazhitov, B.

2018-03-01

One of products from milk fermentation is kefir. It is made by adding kefir grains which are composed of lactic acid bacteria and yeast into milk. The lactic acid bacteria are a group of bacteria that produce antimicrobial substances and able to inhibit the growth of pathogenic bacteria. In this research, the lactic acid bacteria were isolated from Aceh local cow`s milk kefir to determine the genus of the isolates. The methods used in the characterization of lactic acid bacteria are colony morphology, cell morphology, and biochemical tests which includes a catalase test; 5%, 6.5%, and 10% salt endurance tests; 37°C and 14°C temperature endurance tests, SIM test, TSIA test, MR-VP test, and O/F test. Of the four isolates found from the cow’s milk kefir, two isolates were confirmed as lactic acid bacteria (isolates SK-1 and SK-4). Both isolates are Gram positive bacteria, and have negative catalase activity. From the observations of colony morphology, cell morphology, and biochemical tests, it was found that the genus of SK-1 is Lactobacillus and the genus of SK-4 is Enterococcus.

Characterization, identification and application of lactic Acid bacteria isolated from forage paddy rice silage.

PubMed

Ni, Kuikui; Wang, Yanping; Li, Dongxia; Cai, Yimin; Pang, Huili

2015-01-01

There has been growing interest to develop forage rice as a new feed resource for livestock. This study was to characterize the natural population of lactic acid bacteria (LAB) and select potentially excellent strains for paddy rice silage preparation in China. One hundred and twenty-six strains were isolated and screened from paddy rice silage prepared using a small-scale fermentation system, and ninety-nine of these isolates were considered to be LAB based on their Gram-positive and catalase-negative morphology and the production of most of their metabolic products as lactic acid. These isolates were divided into eight groups (A-H) on the basis of their morphological and biochemical characteristics. The Group A to H strains were identified as Lactobacillus (L.) plantarum subsp. plantarum (species ratio: 8.1%), L. casei (5.1%), Leuconostoc (Ln.) pseudomesenteroides (11.1%), Pediococcus (P.) pentosaceus (24.2%), Enterococcus (E.) mundtii (12.1%), Lactococcus (Lc.) garvieae (15.2%), E. faecium (9.1%) and Lc. lactis subsp. lactis (15.2%) based on sequence analyses of their 16S rRNA and recA genes. P. pentosaceus was the most abundant member of the LAB population in the paddy rice silage. A selected strain, namely L. casei R 465, was found to be able to grow under low pH conditions and to improve the silage quality with low pH and a relatively high content of lactic acid. This study demonstrated that forage paddy rice silage contains abundant LAB species and its silage can be well preserved by inoculation with LAB, and that strain R 465 can be a potentially excellent inoculant for paddy rice silage.

Characterization, Identification and Application of Lactic Acid Bacteria Isolated from Forage Paddy Rice Silage

PubMed Central

Ni, Kuikui; Wang, Yanping; Li, Dongxia; Cai, Yimin; Pang, Huili

2015-01-01

There has been growing interest to develop forage rice as a new feed resource for livestock. This study was to characterize the natural population of lactic acid bacteria (LAB) and select potentially excellent strains for paddy rice silage preparation in China. One hundred and twenty-six strains were isolated and screened from paddy rice silage prepared using a small-scale fermentation system, and ninety-nine of these isolates were considered to be LAB based on their Gram-positive and catalase-negative morphology and the production of most of their metabolic products as lactic acid. These isolates were divided into eight groups (A-H) on the basis of their morphological and biochemical characteristics. The Group A to H strains were identified as Lactobacillus (L.) plantarum subsp. plantarum (species ratio: 8.1%), L. casei (5.1%), Leuconostoc (Ln.) pseudomesenteroides (11.1%), Pediococcus (P.) pentosaceus (24.2%), Enterococcus (E.) mundtii (12.1%), Lactococcus (Lc.) garvieae (15.2%), E. faecium (9.1%) and Lc. lactis subsp. lactis (15.2%) based on sequence analyses of their 16S rRNA and recA genes. P. pentosaceus was the most abundant member of the LAB population in the paddy rice silage. A selected strain, namely L. casei R 465, was found to be able to grow under low pH conditions and to improve the silage quality with low pH and a relatively high content of lactic acid. This study demonstrated that forage paddy rice silage contains abundant LAB species and its silage can be well preserved by inoculation with LAB, and that strain R 465 can be a potentially excellent inoculant for paddy rice silage. PMID:25803578

Beer spoilage bacteria and hop resistance.

PubMed

Sakamoto, Kanta; Konings, Wil N

2003-12-31

For brewing industry, beer spoilage bacteria have been problematic for centuries. They include some lactic acid bacteria such as Lactobacillus brevis, Lactobacillus lindneri and Pediococcus damnosus, and some Gram-negative bacteria such as Pectinatus cerevisiiphilus, Pectinatus frisingensis and Megasphaera cerevisiae. They can spoil beer by turbidity, acidity and the production of unfavorable smell such as diacetyl or hydrogen sulfide. For the microbiological control, many advanced biotechnological techniques such as immunoassay and polymerase chain reaction (PCR) have been applied in place of the conventional and time-consuming method of incubation on culture media. Subsequently, a method is needed to determine whether the detected bacterium is capable of growing in beer or not. In lactic acid bacteria, hop resistance is crucial for their ability to grow in beer. Hop compounds, mainly iso-alpha-acids in beer, have antibacterial activity against Gram-positive bacteria. They act as ionophores which dissipate the pH gradient across the cytoplasmic membrane and reduce the proton motive force (pmf). Consequently, the pmf-dependent nutrient uptake is hampered, resulting in cell death. The hop-resistance mechanisms in lactic acid bacteria have been investigated. HorA was found to excrete hop compounds in an ATP-dependent manner from the cell membrane to outer medium. Additionally, increased proton pumping by the membrane bound H(+)-ATPase contributes to hop resistance. To energize such ATP-dependent transporters hop-resistant cells contain larger ATP pools than hop-sensitive cells. Furthermore, a pmf-dependent hop transporter was recently presented. Understanding the hop-resistance mechanisms has enabled the development of rapid methods to discriminate beer spoilage strains from nonspoilers. The horA-PCR method has been applied for bacterial control in breweries. Also, a discrimination method was developed based on ATP pool measurement in lactobacillus cells. However

Enhancement in ex vivo phagocytic capacity of peritoneal leukocytes in mice by oral delivery of various lactic-acid-producing bacteria.

PubMed

Lee, Yeonhee; Lee, Taik-Soo

2005-01-01

Lactic-acid-producing bacteria (LABs) are known to have immunomodulating activity. In the current study, various LABs were tested for their immunity-enhancing activity, especially the phagocytic activity of leukocytes. Viable but not heat-killed cells of Weissella kimchii strain PL9001, Lactobacillus fermentum strain PL9005, and L. plantarum strain PL9011 significantly increased the ex vivo phagocytic capacity of mouse peritoneal leukocytes to ingest fluorescein isothiocyanate (FITC)-labeled Escherichia coli in a strain-dependent manner. Results of this and previous studies suggest these LABs as candidates for new probiotics. This is the first report of the enhancement of peritoneal leukocyte activity of these species.

The Biodiversity of Lactic Acid Bacteria in Greek Traditional Wheat Sourdoughs Is Reflected in Both Composition and Metabolite Formation

PubMed Central

De Vuyst, Luc; Schrijvers, Vincent; Paramithiotis, Spiros; Hoste, Bart; Vancanneyt, Marc; Swings, Jean; Kalantzopoulos, George; Tsakalidou, Effie; Messens, Winy

2002-01-01

Lactic acid bacteria (LAB) were isolated from Greek traditional wheat sourdoughs manufactured without the addition of baker's yeast. Application of sodium dodecyl sulfate-polyacrylamide gel electrophoresis of total cell protein, randomly amplified polymorphic DNA-PCR, DNA-DNA hybridization, and 16S ribosomal DNA sequence analysis, in combination with physiological traits such as fructose fermentation and mannitol production, allowed us to classify the isolated bacteria into the species Lactobacillus sanfranciscensis, Lactobacillus brevis, Lactobacillus paralimentarius, and Weissella cibaria. This consortium seems to be unique for the Greek traditional wheat sourdoughs studied. Strains of the species W. cibaria have not been isolated from sourdoughs previously. No Lactobacillus pontis or Lactobacillus panis strains were found. An L. brevis-like isolate (ACA-DC 3411 t1) could not be identified properly and might be a new sourdough LAB species. In addition, fermentation capabilities associated with the LAB detected have been studied. During laboratory fermentations, all heterofermentative sourdough LAB strains produced lactic acid, acetic acid, and ethanol. Mannitol was produced from fructose that served as an additional electron acceptor. In addition to glucose, almost all of the LAB isolates fermented maltose, while fructose as the sole carbohydrate source was fermented by all sourdough LAB tested except L. sanfranciscensis. Two of the L. paralimentarius isolates tested did not ferment maltose; all strains were homofermentative. In the presence of both maltose and fructose in the medium, induction of hexokinase activity occurred in all sourdough LAB species mentioned above, explaining why no glucose accumulation was found extracellularly. No maltose phosphorylase activity was found either. These data produced a variable fermentation coefficient and a unique sourdough metabolite composition. PMID:12450829

The biodiversity of lactic acid bacteria in Greek traditional wheat sourdoughs is reflected in both composition and metabolite formation.

PubMed

De Vuyst, Luc; Schrijvers, Vincent; Paramithiotis, Spiros; Hoste, Bart; Vancanneyt, Marc; Swings, Jean; Kalantzopoulos, George; Tsakalidou, Effie; Messens, Winy

2002-12-01

Lactic acid bacteria (LAB) were isolated from Greek traditional wheat sourdoughs manufactured without the addition of baker's yeast. Application of sodium dodecyl sulfate-polyacrylamide gel electrophoresis of total cell protein, randomly amplified polymorphic DNA-PCR, DNA-DNA hybridization, and 16S ribosomal DNA sequence analysis, in combination with physiological traits such as fructose fermentation and mannitol production, allowed us to classify the isolated bacteria into the species Lactobacillus sanfranciscensis, Lactobacillus brevis, Lactobacillus paralimentarius, and Weissella cibaria. This consortium seems to be unique for the Greek traditional wheat sourdoughs studied. Strains of the species W. cibaria have not been isolated from sourdoughs previously. No Lactobacillus pontis or Lactobacillus panis strains were found. An L. brevis-like isolate (ACA-DC 3411 t1) could not be identified properly and might be a new sourdough LAB species. In addition, fermentation capabilities associated with the LAB detected have been studied. During laboratory fermentations, all heterofermentative sourdough LAB strains produced lactic acid, acetic acid, and ethanol. Mannitol was produced from fructose that served as an additional electron acceptor. In addition to glucose, almost all of the LAB isolates fermented maltose, while fructose as the sole carbohydrate source was fermented by all sourdough LAB tested except L. sanfranciscensis. Two of the L. paralimentarius isolates tested did not ferment maltose; all strains were homofermentative. In the presence of both maltose and fructose in the medium, induction of hexokinase activity occurred in all sourdough LAB species mentioned above, explaining why no glucose accumulation was found extracellularly. No maltose phosphorylase activity was found either. These data produced a variable fermentation coefficient and a unique sourdough metabolite composition.

Biodiversity and technological-functional potential of lactic acid bacteria isolated from spontaneously fermented quinoa sourdoughs.

PubMed

Ruiz Rodríguez, L; Vera Pingitore, E; Rollan, G; Cocconcelli, P S; Fontana, C; Saavedra, L; Vignolo, G; Hebert, E M

2016-05-01

To analyse lactic acid bacteria (LAB) diversity and technological-functional and safety properties of strains present during spontaneous fermented quinoa sourdoughs. Fermentation was performed by daily backslopping at 30°C for 10 days. Autochthonous LAB microbiota was monitored by a biphasic approach combining random amplified polymorphic DNA (RAPD)-PCR and rRNA gene sequencing with PCR-denaturing gradient gel electrophoresis (DGGE) analysis. Identification and intraspecies differentiation allowed to group isolates within nine LAB species belonging to four genera. A succession of LAB species occurred during 10-days backslopping; Lactobacillus plantarum and Lactobacillus brevis were detected as dominant species in the consortium. The characterization of 15 representative LAB strains was performed based on the acidifying capacity, starch and protein hydrolysis, γ-aminobutyric acid and exopolysaccharides production, antimicrobial activity and antibiotic resistance. Strains characterization led to the selection of Lact. plantarum CRL1905 and Leuconostoc mesenteroides CRL1907 as candidates to be assayed as functional starter culture for the gluten-free (GF) quinoa fermented products. Results on native LAB microbiota present during quinoa sourdough fermentation will allow the selection of strains with appropriate technological properties to be used as a novel functional starter culture for GF-fermented products. © 2016 The Society for Applied Microbiology.

Human milk is a source of lactic acid bacteria for the infant gut.

PubMed

Martín, Rocío; Langa, Susana; Reviriego, Carlota; Jimínez, Esther; Marín, María L; Xaus, Jordi; Fernández, Leonides; Rodríguez, Juan M

2003-12-01

To investigate whether human breast milk contains potentially probiotic lactic acid bacteria, and therefore, whether it can be considered a synbiotic food. Study design Lactic acid bacteria were isolated from milk, mammary areola, and breast skin of eight healthy mothers and oral swabs and feces of their respective breast-fed infants. Some isolates (178 from each mother and newborn pair) were randomly selected and submitted to randomly amplified polymorphic DNA (RAPD) polymerase chain reaction analysis, and those that displayed identical RAPD patterns were identified by 16S rDNA sequencing. Within each mother and newborn pair, some rod-shaped lactic acid bacteria isolated from mammary areola, breast milk, and infant oral swabs and feces displayed identical RAPD profiles. All of them, independently from the mother and child pair, were identified as Lactobacillus gasseri. Similarly, among coccoid lactic acid bacteria from these different sources, some shared an identical RAPD pattern and were identified as Enterococcus faecium. In contrast, none of the lactic acid bacteria isolated from breast skin shared RAPD profiles with lactic acid bacteria of the other sources. Breast-feeding can be a significant source of lactic acid bacteria to the infant gut. Lactic acid bacteria present in milk may have an endogenous origin and may not be the result of contamination from the surrounding breast skin.

Biotechnological production of polyamines by bacteria: recent achievements and future perspectives.

PubMed

Schneider, Jens; Wendisch, Volker F

2011-07-01

In Bacteria, the pathways of polyamine biosynthesis start with the amino acids L-lysine, L-ornithine, L-arginine, or L-aspartic acid. Some of these polyamines are of special interest due to their use in the production of engineering plastics (e.g., polyamides) or as curing agents in polymer applications. At present, the polyamines for industrial use are mainly synthesized on chemical routes. However, since a commercial market for polyamines as well as an industry for the fermentative production of amino acid exist, and since bacterial strains overproducing the polyamine precursors L-lysine, L-ornithine, and L-arginine are known, it was envisioned to engineer these amino acid-producing strains for polyamine production. Only recently, researchers have investigated the potential of amino acid-producing strains of Corynebacterium glutamicum and Escherichia coli for polyamine production. This mini-review illustrates the current knowledge of polyamine metabolism in Bacteria, including anabolism, catabolism, uptake, and excretion. The recent advances in engineering the industrial model bacteria C. glutamicum and E. coli for efficient production of the most promising polyamines, putrescine (1,4-diaminobutane), and cadaverine (1,5-diaminopentane), are discussed in more detail.

Biodiversity of yeasts, lactic acid bacteria and acetic acid bacteria in the fermentation of "Shanxi aged vinegar", a traditional Chinese vinegar.

PubMed

Wu, Jia Jia; Ma, Ying Kun; Zhang, Fen Fen; Chen, Fu Sheng

2012-05-01

Shanxi aged vinegar is a famous traditional Chinese vinegar made from several kinds of cereal by spontaneous solid-state fermentation techniques. In order to get a comprehensive understanding of culturable microorganism's diversity present in its fermentation, the indigenous microorganisms including 47 yeast isolates, 28 lactic acid bacteria isolates and 58 acetic acid bacteria isolates were recovered in different fermenting time and characterized based on a combination of phenotypic and genotypic approaches including inter-delta/PCR, PCR-RFLP, ERIC/PCR analysis, as well as 16S rRNA and 26S rRNA partial gene sequencing. In the alcoholic fermentation, the dominant yeast species Saccharomyces (S.) cerevisiae (96%) exhibited low phenotypic and genotypic diversity among the isolates, while Lactobacillus (Lb.) fermentum together with Lb. plantarum, Lb. buchneri, Lb. casei, Pediococcus (P.) acidilactici, P. pentosaceus and Weissella confusa were predominated in the bacterial population at the same stage. Acetobacter (A.) pasteurianus showing great variety both in genotypic and phenotypic tests was the dominant species (76%) in the acetic acid fermentation stage, while the other acetic acid bacteria species including A. senegalensis, A. indonesiensis, A. malorum and A. orientalis, as well as Gluconobacter (G.) oxydans were detected at initial point of alcoholic and acetic acid fermentation stage respectively. Copyright © 2011 Elsevier Ltd. All rights reserved.

Carrot Juice Fermentations as Man-Made Microbial Ecosystems Dominated by Lactic Acid Bacteria.

PubMed

Wuyts, Sander; Van Beeck, Wannes; Oerlemans, Eline F M; Wittouck, Stijn; Claes, Ingmar J J; De Boeck, Ilke; Weckx, Stefan; Lievens, Bart; De Vuyst, Luc; Lebeer, Sarah

2018-06-15

Spontaneous vegetable fermentations, with their rich flavors and postulated health benefits, are regaining popularity. However, their microbiology is still poorly understood, therefore raising concerns about food safety. In addition, such spontaneous fermentations form interesting cases of man-made microbial ecosystems. Here, samples from 38 carrot juice fermentations were collected through a citizen science initiative, in addition to three laboratory fermentations. Culturing showed that Enterobacteriaceae were outcompeted by lactic acid bacteria (LAB) between 3 and 13 days of fermentation. Metabolite-target analysis showed that lactic acid and mannitol were highly produced, as well as the biogenic amine cadaverine. High-throughput 16S rRNA gene sequencing revealed that mainly species of Leuconostoc and Lactobacillus (as identified by 8 and 20 amplicon sequence variants [ASVs], respectively) mediated the fermentations in subsequent order. The analyses at the DNA level still detected a high number of Enterobacteriaceae , but their relative abundance was low when RNA-based sequencing was performed to detect presumptive metabolically active bacterial cells. In addition, this method greatly reduced host read contamination. Phylogenetic placement indicated a high LAB diversity, with ASVs from nine different phylogenetic groups of the Lactobacillus genus complex. However, fermentation experiments with isolates showed that only strains belonging to the most prevalent phylogenetic groups preserved the fermentation dynamics. The carrot juice fermentation thus forms a robust man-made microbial ecosystem suitable for studies on LAB diversity and niche specificity. IMPORTANCE The usage of fermented food products by professional chefs is steadily growing worldwide. Meanwhile, this interest has also increased at the household level. However, many of these artisanal food products remain understudied. Here, an extensive microbial analysis was performed of spontaneous fermented

Stress Physiology of Lactic Acid Bacteria

PubMed Central

Papadimitriou, Konstantinos; Alegría, Ángel; Bron, Peter A.; de Angelis, Maria; Gobbetti, Marco; Kleerebezem, Michiel; Lemos, José A.; Linares, Daniel M.; Ross, Paul; Stanton, Catherine; Turroni, Francesca; van Sinderen, Douwe; Varmanen, Pekka; Ventura, Marco; Zúñiga, Manuel; Tsakalidou, Effie

2016-01-01

SUMMARY Lactic acid bacteria (LAB) are important starter, commensal, or pathogenic microorganisms. The stress physiology of LAB has been studied in depth for over 2 decades, fueled mostly by the technological implications of LAB robustness in the food industry. Survival of probiotic LAB in the host and the potential relatedness of LAB virulence to their stress resilience have intensified interest in the field. Thus, a wealth of information concerning stress responses exists today for strains as diverse as starter (e.g., Lactococcus lactis), probiotic (e.g., several Lactobacillus spp.), and pathogenic (e.g., Enterococcus and Streptococcus spp.) LAB. Here we present the state of the art for LAB stress behavior. We describe the multitude of stresses that LAB are confronted with, and we present the experimental context used to study the stress responses of LAB, focusing on adaptation, habituation, and cross-protection as well as on self-induced multistress resistance in stationary phase, biofilms, and dormancy. We also consider stress responses at the population and single-cell levels. Subsequently, we concentrate on the stress defense mechanisms that have been reported to date, grouping them according to their direct participation in preserving cell energy, defending macromolecules, and protecting the cell envelope. Stress-induced responses of probiotic LAB and commensal/pathogenic LAB are highlighted separately due to the complexity of the peculiar multistress conditions to which these bacteria are subjected in their hosts. Induction of prophages under environmental stresses is then discussed. Finally, we present systems-based strategies to characterize the “stressome” of LAB and to engineer new food-related and probiotic LAB with improved stress tolerance. PMID:27466284

Stress Physiology of Lactic Acid Bacteria.

PubMed

Papadimitriou, Konstantinos; Alegría, Ángel; Bron, Peter A; de Angelis, Maria; Gobbetti, Marco; Kleerebezem, Michiel; Lemos, José A; Linares, Daniel M; Ross, Paul; Stanton, Catherine; Turroni, Francesca; van Sinderen, Douwe; Varmanen, Pekka; Ventura, Marco; Zúñiga, Manuel; Tsakalidou, Effie; Kok, Jan

2016-09-01

Lactic acid bacteria (LAB) are important starter, commensal, or pathogenic microorganisms. The stress physiology of LAB has been studied in depth for over 2 decades, fueled mostly by the technological implications of LAB robustness in the food industry. Survival of probiotic LAB in the host and the potential relatedness of LAB virulence to their stress resilience have intensified interest in the field. Thus, a wealth of information concerning stress responses exists today for strains as diverse as starter (e.g., Lactococcus lactis), probiotic (e.g., several Lactobacillus spp.), and pathogenic (e.g., Enterococcus and Streptococcus spp.) LAB. Here we present the state of the art for LAB stress behavior. We describe the multitude of stresses that LAB are confronted with, and we present the experimental context used to study the stress responses of LAB, focusing on adaptation, habituation, and cross-protection as well as on self-induced multistress resistance in stationary phase, biofilms, and dormancy. We also consider stress responses at the population and single-cell levels. Subsequently, we concentrate on the stress defense mechanisms that have been reported to date, grouping them according to their direct participation in preserving cell energy, defending macromolecules, and protecting the cell envelope. Stress-induced responses of probiotic LAB and commensal/pathogenic LAB are highlighted separately due to the complexity of the peculiar multistress conditions to which these bacteria are subjected in their hosts. Induction of prophages under environmental stresses is then discussed. Finally, we present systems-based strategies to characterize the "stressome" of LAB and to engineer new food-related and probiotic LAB with improved stress tolerance. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Core Fluxome and Metafluxome of Lactic Acid Bacteria under Simulated Cocoa Pulp Fermentation Conditions

PubMed Central

Adler, Philipp; Bolten, Christoph Josef; Dohnt, Katrin; Hansen, Carl Erik

2013-01-01

In the present work, simulated cocoa fermentation was investigated at the level of metabolic pathway fluxes (fluxome) of lactic acid bacteria (LAB), which are typically found in the microbial consortium known to convert nutrients from the cocoa pulp into organic acids. A comprehensive 13C labeling approach allowed to quantify carbon fluxes during simulated cocoa fermentation by (i) parallel 13C studies with [13C6]glucose, [1,2-13C2]glucose, and [13C6]fructose, respectively, (ii) gas chromatography-mass spectrometry (GC/MS) analysis of secreted acetate and lactate, (iii) stoichiometric profiling, and (iv) isotopomer modeling for flux calculation. The study of several strains of L. fermentum and L. plantarum revealed major differences in their fluxes. The L. fermentum strains channeled only a small amount (4 to 6%) of fructose into central metabolism, i.e., the phosphoketolase pathway, whereas only L. fermentum NCC 575 used fructose to form mannitol. In contrast, L. plantarum strains exhibited a high glycolytic flux. All strains differed in acetate flux, which originated from fractions of citrate (25 to 80%) and corresponding amounts of glucose and fructose. Subsequent, metafluxome studies with consortia of different L. fermentum and L. plantarum strains indicated a dominant (96%) contribution of L. fermentum NCC 575 to the overall flux in the microbial community, a scenario that was not observed for the other strains. This highlights the idea that individual LAB strains vary in their metabolic contribution to the overall fermentation process and opens up new routes toward streamlined starter cultures. L. fermentum NCC 575 might be one candidate due to its superior performance in flux activity. PMID:23851099

Biotechnological applications of acetic acid bacteria.

PubMed

Raspor, Peter; Goranovic, Dusan

2008-01-01

The acetic acid bacteria (AAB) have important roles in food and beverage production, as well as in the bioproduction of industrial chemicals. In recent years, there have been major advances in understanding their taxonomy, molecular biology, and physiology, and in methods for their isolation and identification. AAB are obligate aerobes that oxidize sugars, sugar alcohols, and ethanol with the production of acetic acid as the major end product. This special type of metabolism differentiates them from all other bacteria. Recently, the AAB taxonomy has been strongly rearranged as new techniques using 16S rRNA sequence analysis have been introduced. Currently, the AAB are classified in ten genera in the family Acetobacteriaceae. AAB can not only play a positive role in the production of selected foods and beverages, but they can also spoil other foods and beverages. AAB occur in sugar- and alcohol-enriched environments. The difficulty of cultivation of AAB on semisolid media in the past resulted in poor knowledge of the species present in industrial processes. The first step of acetic acid production is the conversion of ethanol from a carbohydrate carried out by yeasts, and the second step is the oxidation of ethanol to acetic acid carried out by AAB. Vinegar is traditionally the product of acetous fermentation of natural alcoholic substrates. Depending on the substrate, vinegars can be classified as fruit, starch, or spirit substrate vinegars. Although a variety of bacteria can produce acetic acid, mostly members of Acetobacter, Gluconacetobacter, and Gluconobacter are used commercially. Industrial vinegar manufacturing processes fall into three main categories: slow processes, quick processes, and submerged processes. AAB also play an important role in cocoa production, which represents a significant means of income for some countries. Microbial cellulose, produced by AAB, possesses some excellent physical properties and has potential for many applications. Other

[Screening, identification and phosphate-solubilizing characteristics of phosphate-solubilizing bacteria strain D2 (Pantoea sp.)in rhizosphere of Pinus tabuliformis in iron tailings yard.

PubMed

Wang, Jun Juan; Yan, Ai Hua; Wang, Wei; Li, Ji Quan; Li, Yu Ling

2016-11-18

Two strains of phosphate-solubilizing bacteria were isolated from the rhizosphere of Pinus tabuliformis in iron tailings vegetation restoration areas in Malan Town, Qianan City, Hebei Pro-vince. The bacterial strain D2 with strong phosphate-solubilizing capacity was obtained via screening with plate and shake flask. Based on the morphology, physiology and biochemistry, and the sequence analysis of 16S rDNA, the D2 was identified as a member of Pantoea sp. A fermentation experiment was conducted to investigate the effect of carbon and nitrogen sources on the phosphate-solubilizing capacity of the strain D2; under different nitrogen sources, the organic acids in liquid culture, as well as their types and contents were determined by high performance liquid chromatography. The results showed that the strain D2 was capable of efficiently solubilizing tricalcium phosphate, and the highest value of available phosphorus was up to 392.13 mg·L -1 in liquid culture. The strain D2 displayed the strongest phosphate-solubilizing capability when glucose and ammonium sulfate were used as carbon and nitrogen sources in the culture media, respectively. Under varied nitrogen sources, the resulting organic acids and their types and contents were different. When the nitrogen source in culture media was ammonium sulfate, ammonium chloride, potassium nitrate, sodium nitrate or ammonium nitrate, all four organic acids, including oxalic acid, formic acid, acetic acid and citric acid, were produced. In addition, malic acid was uniquely produced when ammonium sulfate, ammonium chloride or ammonium nitrate was used as the nitrogen source. By Pearson's correlation analysis, a significant positive correlation between the acetic acid content and the available phosphorus content was found (r=0.886, P<0.05), suggesting that acetic acid produced by strain D2 played an important role in promoting inorganic phosphorus dissolution, which was most likely to be one of the important phosphate

Adding Value to Goat Meat: Biochemical and Technological Characterization of Autochthonous Lactic Acid Bacteria to Achieve High-Quality Fermented Sausages

PubMed Central

Nediani, Miriam T.; García, Luis; Saavedra, Lucila; Martínez, Sandra; López Alzogaray, Soledad; Fadda, Silvina

2017-01-01

Quality and safety are important challenges in traditional fermented sausage technology. Consequently, the development of a tailored starter culture based on indigenous microbiota constitutes an interesting alternative. In the present study, spontaneously fermented goat meat sausages were created and analyzed using a physicochemical and microbiological approach. Thereafter 170 lactic acid bacteria (LAB) strains were isolated and preliminary characterized by phenotypic assays. The hygienic and technological properties, and growth and fermentative potential of isolates using a goat-meat-based culture medium were evaluated. All strains proved to have bioprotective features due to their acidogenic metabolism. Almost all grew optimally in meat environments. LAB isolates presented proteolytic activity against meat proteins and enriched amino acid contents of the goat-meat-based model. The most efficient strains were four different Lactobacillus sakei isolates, as identified by genotyping and RAPD analysis. L. sakei strains are proposed as optimal candidates to improve the production of fermented goat meat sausages, creating a new added-value fermented product. PMID:28513575

Adding Value to Goat Meat: Biochemical and Technological Characterization of Autochthonous Lactic Acid Bacteria to Achieve High-Quality Fermented Sausages.

PubMed

Nediani, Miriam T; García, Luis; Saavedra, Lucila; Martínez, Sandra; López Alzogaray, Soledad; Fadda, Silvina

2017-05-17

Quality and safety are important challenges in traditional fermented sausage technology. Consequently, the development of a tailored starter culture based on indigenous microbiota constitutes an interesting alternative. In the present study, spontaneously fermented goat meat sausages were created and analyzed using a physicochemical and microbiological approach. Thereafter 170 lactic acid bacteria (LAB) strains were isolated and preliminary characterized by phenotypic assays. The hygienic and technological properties, and growth and fermentative potential of isolates using a goat-meat-based culture medium were evaluated. All strains proved to have bioprotective features due to their acidogenic metabolism. Almost all grew optimally in meat environments. LAB isolates presented proteolytic activity against meat proteins and enriched amino acid contents of the goat-meat-based model. The most efficient strains were four different Lactobacillus sakei isolates, as identified by genotyping and RAPD analysis. L. sakei strains are proposed as optimal candidates to improve the production of fermented goat meat sausages, creating a new added-value fermented product.

[Effect of Gram-negative bacteria on fatty acids].

PubMed

Vuillemin, N; Dupeyron, C; Leluan, G; Bory, J

1981-01-01

The gram-negative bacteria investigated exert various effects on fatty acids. P. aeruginosa and A. calcoaceticus catabolize any of the fatty acids tested. S. marcescens is effective upon all fatty acids excepting butyric acid. The long chain fatty acids only are degraded by E. coli, meanwhile the other fatty acids present a bacteriostatic or bactericidal activity on it. The authors propose a simple and original method for testing the capability of degradation of fatty acids by some bacterial species.

Dietary hyperoxaluria is not reduced by treatment with lactic acid bacteria

PubMed Central

2013-01-01

Background Secondary hyperoxaluria either based on increased intestinal absorption of oxalate (enteric), or high oxalate intake (dietary), is a major risk factor of calcium oxalate urolithiasis. Oxalate-degrading bacteria might have beneficial effects on urinary oxalate excretion resulting from decreased intestinal oxalate concentration and absorption. Methods Twenty healthy subjects were studied initially while consuming a diet normal in oxalate. Study participants were then placed on a controlled oxalate-rich diet for a period of 6 weeks. Starting with week 2 of the oxalate-rich diet, participants received 2.6 g/day of a lactic acid bacteria preparation for 5 weeks. Finally, subjects were examined 4 weeks after treatment while consuming again a normal-oxalate diet. Participants provided weekly 24-hour urine specimens. Analyses of blood samples were performed before and at the end of treatment. Results Urinary oxalate excretion increased significantly from 0.354 ± 0.097 at baseline to 0.542 ± 0.163 mmol/24 h under the oxalate-rich diet and remained elevated until the end of treatment, as did relative supersaturation of calcium oxalate. Plasma oxalate concentration was significantly higher after 5 weeks of treatment compared to baseline. Four weeks after treatment, urinary oxalate excretion and relative supersaturation of calcium oxalate fell to reach initial values. Conclusions Persistent dietary hyperoxaluria and increased plasma oxalate concentration can already be induced in healthy subjects without disorders of oxalate metabolism. The study preparation neither reduced urinary oxalate excretion nor plasma oxalate concentration. The preparation may be altered to select for lactic acid bacteria strains with the highest oxalate-degrading activity. PMID:24330782

Fermented probiotic beverages based on acid whey.

PubMed

Skryplonek, Katarzyna; Jasińska, Małgorzata

2015-01-01

Production of fermented probiotic beverages can be a good method for acid whey usage. The obtained products combine a high nutritional value of whey with health benefits claimed for probiotic bacteria. The aim of the study was to define quality properties of beverages based on fresh acid whey and milk with addition of buttermilk powder or sweet whey powder. Samples were inoculated with two strains of commercial probiotic cultures: Lactobacillus acidophilus La-5 or Bifidobacterium animalis Bb-12. After fermentation, samples were stored at refrigerated conditions. After 1, 4, 7, 14 and 21 days sensory characteristics, hardness, acetaldehyde content, titratable acidity, pH acidity and count of bacteria cells were evaluated. Throughout all storage period, the number of bacteria was higher than 8 log cfu/ml in the all samples. Beverages with La-5 strain had higher hardness and acidity, whilst samples with Bb-12 contained more acetaldehyde. Samples with buttermilk powder had better sensory properties than with sweet whey powder. Obtained products made of acid whey combined with milk and fortified with buttermilk powder or sweet whey powder, are good medium for growth and survival of examined probiotic bacteria strains. The level of bacteria was sufficient to provide health benefits to consumers.

Recommendations for improved use of the murine TNBS-induced colitis model in evaluating anti-inflammatory properties of lactic acid bacteria: technical and microbiological aspects.

PubMed

Foligné, Benoit; Nutten, Sophie; Steidler, Lothar; Dennin, Véronique; Goudercourt, Denise; Mercenier, Annick; Pot, Bruno

2006-02-01

Probiotic bacteria have been shown to exert promising beneficial effects in different types of intestinal disorders, including chronic inflammation. In this context, animal models of inflammatory bowel disease are useful in studying the possible prophylactic role of candidate probiotic strains. This study aimed at evaluating the critical technological and microbiological parameters as well as the robustness of the murine trinitrobenzene sulfonic acid (TNBS)-induced model of colitis, after intragastric administration of lactic acid bacteria (LAB) preparations. A standardized methodology was applied to assess the protective effect achieved by various bacterial concentrations and culture conditions of the reference strain Lactobacillus plantarum NCIMB 8826. Not only was protection found to vary in function in different levels of colitis, but also repeated experiments showed a clear bacterial dose-dependent attenuation of colitis. The physiological stage of bacteria was shown to impact as well, with substantial, mild, or reduced improvement of inflammatory scores for exponentially growing, stationary-phase, or killed bacteria, respectively. A recombinant strain, secreting murine interleukin-10 (IL-10) and previously reported to successfully treat colitis in two different models of murine colitis (dextran sulfate sodium [DSS] and IL-10-deficient mice), was used to validate the final experimental conditions. In conclusion, we identified and optimized some of the key parameters that need to be controlled in order to ensure reliable comparison of results generated over a long period of time or independent experiments. The recommendations for an improved model presented here will prove to be helpful for reproducible, independent comparison of the anti-inflammatory potential of wild-type or recombinant candidate probiotic strains, whether administered as pure cultures or as blends.

Production of pyroglutamic acid by thermophilic lactic acid bacteria in hard-cooked mini-cheeses.

PubMed

Mucchetti, G; Locci, F; Massara, P; Vitale, R; Neviani, E

2002-10-01

Pyroglutamic acid is present in high amounts (0.5g/ 100g) in many cheese varieties-and particularly in extensively ripened Italian cheeses such as Grana Padano and Parmigiano Reggiano. An in vivo model system for cooked mini-cheese production and ripening acceleration was set up to demonstrate the ability of thermophilic lactic acid bacteria, used as a starter, to produce pyroglutamic acid (pGlu). In mini-cheeses stored at 38 and 30 degrees C for up to 45 d, all starters tested produced different amounts of pGlu. In descending order of pGlu production, the bacteria analyzed were: Lactobacillus helveticus, Lactobacillus delbrueckii subsp. bulgaricus, Streptococcus thermophilus, and Lactobacillus delbrueckii subsp. lactis. Evidence for the presence of glutamine to pGlu cyclase activity in lactic acid bacteria was provided. Cell lysates obtained from cultures of L. helveticus, L. delbrueckii subsp. bulgaricus, L. delbrueckii subsp. lactis, and S. thermophilus showed the ability to cyclize glutamine to pGlu, resulting in processing yields from 1.4 to 30.3%, depending on the subspecies. Formation of pGlu from free glutamine appeared to be similar to that observed using a glutamine-glutamine dipeptide substrate. Under the experimental conditions applied, pGlu aminopeptidase activity was only detected in L. helveticus. Thus, pGlu formation in long-ripened cooked cheese may depend on the activity of thermophilic lactic acid bacteria.

Heme and menaquinone induced electron transport in lactic acid bacteria

PubMed Central

Brooijmans, Rob; Smit, Bart; Santos, Filipe; van Riel, Jan; de Vos, Willem M; Hugenholtz, Jeroen

2009-01-01

Background For some lactic acid bacteria higher biomass production as a result of aerobic respiration has been reported upon supplementation with heme and menaquinone. In this report, we have studied a large number of species among lactic acid bacteria for the existence of this trait. Results Heme- (and menaquinone) stimulated aerobic growth was observed for several species and genera of lactic acid bacteria. These include Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacilllus brevis, Lactobacillus paralimentarius, Streptococcus entericus and Lactococcus garviae. The increased biomass production without further acidification, which are respiration associated traits, are suitable for high-throughput screening as demonstrated by the screening of 8000 Lactococcus lactis insertion mutants. Respiration-negative insertion-mutants were found with noxA, bd-type cytochrome and menaquinol biosynthesis gene-disruptions. Phenotypic screening and in silico genome analysis suggest that respiration can be considered characteristic for certain species. Conclusion We propose that the cyd-genes were present in the common ancestor of lactic acid bacteria, and that multiple gene-loss events best explains the observed distribution of these genes among the species. PMID:19480672

Heme and menaquinone induced electron transport in lactic acid bacteria.

PubMed

Brooijmans, Rob; Smit, Bart; Santos, Filipe; van Riel, Jan; de Vos, Willem M; Hugenholtz, Jeroen

2009-05-29

For some lactic acid bacteria higher biomass production as a result of aerobic respiration has been reported upon supplementation with heme and menaquinone. In this report, we have studied a large number of species among lactic acid bacteria for the existence of this trait. Heme- (and menaquinone) stimulated aerobic growth was observed for several species and genera of lactic acid bacteria. These include Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacilllus brevis, Lactobacillus paralimentarius, Streptococcus entericus and Lactococcus garviae. The increased biomass production without further acidification, which are respiration associated traits, are suitable for high-throughput screening as demonstrated by the screening of 8000 Lactococcus lactis insertion mutants. Respiration-negative insertion-mutants were found with noxA, bd-type cytochrome and menaquinol biosynthesis gene-disruptions. Phenotypic screening and in silico genome analysis suggest that respiration can be considered characteristic for certain species. We propose that the cyd-genes were present in the common ancestor of lactic acid bacteria, and that multiple gene-loss events best explains the observed distribution of these genes among the species.

Linking wine lactic acid bacteria diversity with wine aroma and flavour.

PubMed

Cappello, Maria Stella; Zapparoli, Giacomo; Logrieco, Antonio; Bartowsky, Eveline J

2017-02-21

In the last two decades knowledge on lactic acid bacteria (LAB) associated with wine has increased considerably. Investigations on genetic and biochemistry of species involved in malolactic fermentation, such as Oenococcus oeni and of Lactobacillus have enabled a better understand of their role in aroma modification and microbial stability of wine. In particular, the use of molecular techniques has provided evidence on the high diversity at species and strain level, thus improving the knowledge on wine LAB taxonomy and ecology. These tools demonstrated to also be useful to detect strains with potential desirable or undesirable traits for winemaking purposes. At the same time, advances on the enzymatic properties of wine LAB responsible for the development of wine aroma molecules have been undertaken. Interestingly, it has highlighted the high intraspecific variability of enzymatic activities such as glucosidase, esterase, proteases and those related to citrate metabolism within the wine LAB species. This genetic and biochemistry diversity that characterizes wine LAB populations can generate a wide spectrum of wine sensory outcomes. This review examines some of these interesting aspects as a way to elucidate the link between LAB diversity with wine aroma and flavour. In particular, the correlation between inter- and intra-species diversity and bacterial metabolic traits that affect the organoleptic properties of wines is highlighted with emphasis on the importance of enzymatic potential of bacteria for the selection of starter cultures to control MLF and to enhance wine aroma. Copyright © 2016 Elsevier B.V. All rights reserved.

Sugar fatty acid esters inhibit biofilm formation by food-borne pathogenic bacteria

PubMed Central

Furukawa, Soichi; Akiyoshi, Yuko; O’Toole, George A.; Ogihara, Hirokazu; Morinaga, Yasushi

2010-01-01

Effects of food additives on biofilm formation by food-borne pathogenic bacteria were investigated. Thirty-three potential food additives and 3 related compounds were added to the culture medium at concentrations from 0.001 to 0.1% (w/w), followed by inoculation and cultivation of five biofilm-forming bacterial strains for the evaluation of biofilm formation. Among the tested food additives, 21 showed inhibitory effects of biofilm formation by Staphylococcus aureus and Escherichia coli, and in particular, sugar fatty acid esters showed significant anti-biofilm activity. Sugar fatty acid esters with long chain fatty acid residues (C14-16) exerted their inhibitory effect at the concentration of 0.001%(w/w), but bacterial growth was not affected at this low concentration. Activities of the sugar fatty acid esters positively correlated with the increase of the chain length of the fatty acid residues. Sugar fatty acid esters inhibited the initial attachment of the Staphylococcus aureus cells to the abiotic surface. Sugar fatty acid esters with long chain fatty acid residues (C14-16) also inhibited biofilm formation by Streptococcus mutans and Listeria monocytogenes at 0.01%(w/w), while the inhibition of biofilm formation by Pseudomonas aeruginosa required the addition of a far higher concentration (0.1%(w/w)) of the sugar fatty acid esters. PMID:20089325

Analysis of competition in soil among 2,4-dichlorophenoxyacetic acid-degrading bacteria.

PubMed Central

Ka, J O; Holben, W E; Tiedje, J M

1994-01-01

Competition among indigenous and inoculated 2,4-dichlorophenoxyacetic acid (2,4-D)-degrading bacteria was studied in a native Kansas prairie soil following 2,4-D additions. The soil was inoculated with four different 2,4-D-degrading strains at densities of 10(3) cells per g of soil; the organisms used were Pseudomonas cepacia DBO1(pJP4) and three Michigan soil isolates, strain 745, Sphingomonas paucimobilis 1443, and Pseudomonas pickettii 712. Following 2,4-D additions, total soil DNA was extracted and analyzed on Southern blots by using a tfdA gene probe which detected three of the strains and another probe that detected the fourth strain, S. paucimobilis 1443, which belongs to a different class of 2,4-D degraders. P. cepacia DBO1(pJP4), a constructed strain, outcompeted the other added strains and the indigenous 2,4-D-degrading populations. The S. paucimobilis population was the secondary dominant population, and strain 745 and P. pickettii were not detected. Relative fitness coefficients determined in axenic broth cultures predicted the outcome of competition in soil for some but not all strains. Lag time was shown to be a principal determinant of competitiveness among the strains, but the lag times were significantly reduced in mixed broth cultures, which changed the competitive outcome. Plasmids containing the genes for the 2,4-D pathway were important determinants of competitiveness since plasmid pKA4 in P. cepacia DBO1 resulted in the slower growth characteristic of its original host, P. pickettii, rather than the rapid growth observed when this strain harbors pJP4. Images PMID:8017909

Bacteriocins from lactic acid bacteria: production, purification, and food applications.

PubMed

De Vuyst, Luc; Leroy, Frédéric

2007-01-01

In fermented foods, lactic acid bacteria (LAB) display numerous antimicrobial activities. This is mainly due to the production of organic acids, but also of other compounds, such as bacteriocins and antifungal peptides. Several bacteriocins with industrial potential have been purified and characterized. The kinetics of bacteriocin production by LAB in relation to process factors have been studied in detail through mathematical modeling and positive predictive microbiology. Application of bacteriocin-producing starter cultures in sourdough (to increase competitiveness), in fermented sausage (anti-listerial effect), and in cheese (anti-listerial and anti-clostridial effects), have been studied during in vitro laboratory fermentations as well as on pilot-scale level. The highly promising results of these studies underline the important role that functional, bacteriocinogenic LAB strains may play in the food industry as starter cultures, co-cultures, or bioprotective cultures, to improve food quality and safety. In addition, antimicrobial production by probiotic LAB might play a role during in vivo interactions occurring in the human gastrointestinal tract, hence contributing to gut health.

Genetic and Technological Characterisation of Vineyard- and Winery-Associated Lactic Acid Bacteria

PubMed Central

Nisiotou, Aspasia A.; Filippousi, Maria-Evangelia; Fragkoulis, Petros; Tassou, Chryssoula; Banilas, Georgios

2015-01-01

Vineyard- and winery-associated lactic acid bacteria (LAB) from two major PDO regions in Greece, Peza and Nemea, were surveyed. LAB were isolated from grapes, fermenting musts, and winery tanks performing spontaneous malolactic fermentations (MLF). Higher population density and species richness were detected in Nemea than in Peza vineyards and on grapes than in fermenting musts. Pediococcus pentosaceus and Lactobacillus graminis were the most abundant LAB on grapes, while Lactobacillus plantarum dominated in fermenting musts from both regions. No particular structure of Lactobacillus plantarum populations according to the region of origin was observed, and strain distribution seems random. LAB species diversity in winery tanks differed significantly from that in vineyard samples, consisting principally of Oenococcus oeni. Different strains were analysed as per their enological characteristics and the ability to produce biogenic amines (BAs). Winery-associated species showed higher resistance to low pH, ethanol, SO2, and CuSO4 than vineyard-associated isolates. The frequency of BA-producing strains was relatively low but not negligible, considering that certain winery-associated Lactobacillus hilgardii strains were able to produce BAs. Present results show the necessity of controlling the MLF by selected starters in order to avoid BA accumulation in wine. PMID:25866789

Phenotypic and genomic survey on organic acid utilization profile of Pseudomonas mendocina strain S5.2, a vineyard soil isolate.

PubMed

Chong, Teik Min; Chen, Jian-Woon; See-Too, Wah-Seng; Yu, Choo-Yee; Ang, Geik-Yong; Lim, Yan Lue; Yin, Wai-Fong; Grandclément, Catherine; Faure, Denis; Dessaux, Yves; Chan, Kok-Gan

2017-12-01

Root exudates are chemical compounds that are released from living plant roots and provide significant energy, carbon, nitrogen and phosphorus sources for microbes inhabiting the rhizosphere. The exudates shape the microflora associated with the plant, as well as influences the plant health and productivity. Therefore, a better understanding of the trophic link that is established between the plant and the associated bacteria is necessary. In this study, a comprehensive survey on the utilization of grapevine and rootstock related organic acids were conducted on a vineyard soil isolate which is Pseudomonas mendocina strain S5.2. Phenotype microarray analysis has demonstrated that this strain can utilize several organic acids including lactic acid, succinic acid, malic acid, citric acid and fumaric acid as sole growth substrates. Complete genome analysis using single molecule real-time technology revealed that the genome consists of a 5,120,146 bp circular chromosome and a 252,328 bp megaplasmid. A series of genetic determinants associated with the carbon utilization signature of the strain were subsequently identified in the chromosome. Of note, the coexistence of genes encoding several iron-sulfur cluster independent isoenzymes in the genome indicated the importance of these enzymes in the events of iron deficiency. Synteny and comparative analysis have also unraveled the unique features of D-lactate dehydrogenase of strain S5.2 in the study. Collective information of this work has provided insights on the metabolic role of this strain in vineyard soil rhizosphere.

In vitro screening of probiotic lactic acid bacteria and prebiotic glucooligosaccharides to select effective synbiotics.

PubMed

Grimoud, Julien; Durand, Henri; Courtin, Céline; Monsan, Pierre; Ouarné, Françoise; Theodorou, Vassilia; Roques, Christine

2010-10-01

Probiotics and prebiotics have been demonstrated to positively modulate the intestinal microflora and could promote host health. Although some studies have been performed on combinations of probiotics and prebiotics, constituting synbiotics, results on the synergistic effects tend to be discordant in the published works. The first aim of our study was to screen some lactic acid bacteria on the basis of probiotic characteristics (resistance to intestinal conditions, inhibition of pathogenic strains). Bifidobacterium was the most resistant genus whereas Lactobacillus farciminis was strongly inhibited. The inhibitory effect on pathogen growth was strain dependent but lactobacilli were the most effective, especially L. farciminis. The second aim of the work was to select glucooligosaccharides for their ability to support the growth of the probiotics tested. We demonstrated the selective fermentability of oligodextran and oligoalternan by probiotic bacteria, especially the bifidobacteria, for shorter degrees of polymerisation and absence of metabolism by pathogenic bacteria. Thus, the observed characteristics confer potential prebiotic properties on these glucooligosaccharides, to be further confirmed in vivo, and suggest some possible applications in synbiotic combinations with the selected probiotics. Furthermore, the distinctive patterns of the different genera suggest a combination of lactobacilli and bifidobacteria with complementary probiotic effects in addition to the prebiotic ones. These associations should be further evaluated for their synbiotic effects through in vitro and in vivo models. Copyright © 2010 Elsevier Ltd. All rights reserved.

Extracellular protease derived from lactic acid bacteria stimulates the fermentative lactic acid production from the by-products of rice as a biomass refinery function.

PubMed

Watanabe, Masanori; Techapun, Charin; Kuntiya, Ampin; Leksawasdi, Noppol; Seesuriyachan, Phisit; Chaiyaso, Thanongsak; Takenaka, Shinji; Maeda, Isamu; Koyama, Masahiro; Nakamura, Kozo

2017-02-01

A lactic acid producing bacterium, Lactobacillus rhamnosus M-23, newly isolated from a rice washing drainage storage tank was found to produce l-(+)-lactic acid from a non-sterilized mixture of rice washing drainage and rice bran without any additions of nutrients under the simultaneous saccharification and fermentation (SSF) process. This strain has the ability to utilize the non-sterilized rice washing drainage and rice bran as a source of carbohydrate, saccharifying enzymes and nutrients for lactic acid production. Observation of extracellular protease activity in SSF culture broth showed that a higher protease activity was present in strain M-23 than in other isolated lactic acid producing bacteria (LABs). To investigate the structural changes of solid particles of rice washing drainage throughout LAB cultivation, scanning electron microscopic (SEM) observation and Fourier transform infrared-spectroscopy (FT-IR) analysis were performed. The results of the SEM observation showed that the surface material could be removed from solid particles of rice washing drainage treated by culture broth (supernatant) of strain M-23, thus exposing the crystal structure of the starch particle surface. The results of the FT-IR analysis revealed that the specific transmittance decrease of the CC and CO stretching and OH group of the solid particles of the rice washing drainage were highly correlated with the produced lactic acid concentration and extracellular protease activity, respectively. These results demonstrate the high lactic acid producing ability of strain M-23 from a non-sterilized mixture of rice washing drainage and rice bran under the SSF condition due to the removal of proteinaceous material and exposure of the starch particle surface by extracellular protease. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Adaptability of lactic acid bacteria and yeasts to sourdoughs prepared from cereals, pseudocereals and cassava and use of competitive strains as starters.

PubMed

Vogelmann, Stephanie A; Seitter, Michael; Singer, Ulrike; Brandt, Markus J; Hertel, Christian

2009-04-15

The adaptability of lactic acid bacteria (LAB) and yeasts to sourdoughs prepared from cereals, pseudocereals and cassava was investigated using PCR-DGGE and bacteriological culture combined with rRNA gene sequence analysis. Sourdoughs were prepared either from flours of the cereals wheat, rye, oat, barley, rice, maize, and millet, or from the pseudocereals amaranth, quinoa, and buckwheat, or from cassava, using a starter consisting of various species of LAB and yeasts. Doughs were propagated until a stable microbiota was established. The dominant LAB and yeast species were Lactobacillus fermentum, Lactobacillus helveticus, Lactobacillus paralimentarius, Lactobacillus plantarum, Lactobacillus pontis, Lactobacillus spicheri, Issatchenkia orientalis and Saccharomyces cerevisiae. The proportion of the species within the microbiota varied. L. paralimentarius dominated in the pseudocereal sourdoughs, L. fermentum, L. plantarum and L. spicheri in the cassava sourdough, and L. fermentum, L. helveticus and L. pontis in the cereal sourdoughs. S. cerevisiae constituted the dominating yeast, except for quinoa sourdough, where I. orientalis also reached similar counts, and buckwheat and oat sourdoughs, where no yeasts could be detected. To assess the usefulness of competitive LAB and yeasts as starters, the fermentations were repeated using flours from rice, maize, millet and the pseudocereals, and by starting the dough fermentation with selected dominant strains. At the end of fermentation, most of starter strains belonged to the dominating microbiota. For the rice, millet and quinoa sourdoughs the species composition was similar to that of the prior fermentation, whereas in the other sourdoughs, the composition differed.

The inhibitory effects of wine phenolics on lysozyme activity against lactic acid bacteria.

PubMed

Guzzo, F; Cappello, M S; Azzolini, M; Tosi, E; Zapparoli, G

2011-08-15

The lysozyme of hen's egg white is used in winemaking to control spontaneous lactic acid bacteria (LAB). A total of eight LAB strains, isolated from grape must and wine, were used to assess the inhibitory effects of wine phenolics on lysozyme activity. The presence of phenolics, extracted from grape pomace, in growth medium reduced the mortality rate due to the lysozyme activity. This effect was especially clear in the case of strains belonging to Lactobacillus uvarum, Pediococcus parvulus and Oenococccus oeni, which are more sensitive to lysozyme than L. plantarum and L. hilgardii strains. Cell lysis assays carried out on four strains sensitive to lysozyme and Micrococcus lysodeikticus ATCC 4698, used as a reference strain, confirmed the inhibition of grape pomace phenolics on the muramidase. There was no interference from non-flavonoids, flavanols and flavonol compounds, when they were tested individually, on the lysozyme activity against the strains. Anthocyanins extracted from grape skins slightly inhibited the activity only against M. lysodeikticus. However, proanthocyanidins extracted from seed berries, strongly inhibited the lysozyme. In this extract, dimers were the predominant oligomers of flavan-3-ol. The study demonstrated that the effectiveness of lysozyme against LAB in red winemaking is related to the amount of low molecular weight proanthocyanidins that are released when the grapes are macerating. Copyright © 2011 Elsevier B.V. All rights reserved.

Production of Value-added Products by Lactic Acid Bacteria

USDA-ARS?s Scientific Manuscript database

Lactic acid bacteria (LAB) are a group of facultative anaerobic, catalase negative, nonmotile and nonsporeforming–Gram positive bacteria. Most LAB utilize high energy C sources including monomer sugars to produce energy to maintain cellular structure and function. This anaerobic fermentation proce...

Biopolymers from lactic acid bacteria. Novel applications in foods and beverages

PubMed Central

Torino, María I.; Font de Valdez, Graciela; Mozzi, Fernanda

2015-01-01

Lactic acid bacteria (LAB) are microorganisms widely used in the fermented food industry worldwide. Certain LAB are able to produce exopolysaccharides (EPS) either attached to the cell wall (capsular EPS) or released to the extracellular environment (EPS). According to their composition, LAB may synthesize heteropolysaccharides or homopolysaccharides. A wide diversity of EPS are produced by LAB concerning their monomer composition, molecular mass, and structure. Although EPS-producing LAB strains have been traditionally applied in the manufacture of dairy products such as fermented milks and yogurts, their use in the elaboration of low-fat cheeses, diverse type of sourdough breads, and certain beverages are some of the novel applications of these polymers. This work aims to collect the most relevant issues of the former reviews concerning the monomer composition, structure, and yields and biosynthetic enzymes of EPS from LAB; to describe the recently characterized EPS and to present the application of both EPS-producing strains and their polymers in the fermented (specifically beverages and cereal-based) food industry. PMID:26441845

[Isolation and Identification of Petroleum Degradation Bacteria and Interspecific Interactions Among Four Bacillus Strains].

PubMed

Wang, Jia-nan; Shi, Yan-yun; Zheng, Li-yan; Wang, Zhe; Cai, Zhang; Liu, Jie

2015-06-01

Six petroleum-degrading strains were isolated from oil-contaminated soil at Dagang oil field and oil sewage on Bohai offshore drilling platform in Tianjin using enrichment culture and isolation method. The physiological biochemical test together with 16S rDNA sequencing analysis indicated that they belonged to Bacillus (S1, S2, S3, S4), Pseudomonas (W1) and Ochrobactrum (W2), respectively. The strain S3 had the maximum degradation rate of alkane (41.3%) and aromatic hydrocarbon (30.9%) among all isolated strains showing the better degradation efficiency by endogenous bacteria when compared to that by the exogenous bacteria. The four Bacillus strains were used to construct microbiome, thereafter subjected to petroleum degradation efficiency test and analyzed. The results showed that microbiome F3 consisting of S1 and S4 had the maximum degradation rates of alkane (50.5%) and aromatic hydrocarbon (54.0%), which were 69.9% and 156.1% higher than those by single bacterium, respectively. Furthermore, they were 22.1% and 74.6% respectively higher than those by the most optimal degradation bacterium S3. Microbiome F4 consisting of S2 and S3 had the minimum degradation rates of alkane (18.5%) and aromatic hydrocarbon (18.9%) which were 55.3% and 39.0% lower than the degradation rates of single bacterium, respectively. The results also demonstrated that there were both microbial synergy promotion and antagonism inhibition among bacteria of the same genus in the petroleum degradation period. Bacteria with close affinity in Bacillus genus displayed mainly promoted petroleum degradation effect.

Industrial application of selected lactic acid bacteria isolated from local semolinas for typical sourdough bread production.

PubMed

Corona, Onofrio; Alfonzo, Antonio; Ventimiglia, Giusi; Nasca, Anna; Francesca, Nicola; Martorana, Alessandra; Moschetti, Giancarlo; Settanni, Luca

2016-10-01

Four obligate heterofermentative lactic acid bacteria (LAB) strains (Weissella cibaria PON10030 and PON10032 and Leuconostoc citreum PON 10079 and PON10080) were tested as single strain starters, mono-species dual strain starters, and multiple strain starter for the preparation and propagation of sourdoughs for the production of a typical bread at industrial level. The kinetics of pH and TTA during the daily sourdough refreshments indicated a correct acidification process for all trials. The concentration of lactic and acetic acid increased consistently during fermentation. The resulting molar ratios between these two organic acids in the experimental trials were lower than those observed in the control trial. The microbiological investigation showed levels of approximately 10(9) CFU/mL in almost all sourdoughs and the comparison of the genetic polymorphisms of the dominating LAB with those of the pure cultures evidenced the persistence of the added strains over time. The resulting breads were evaluated for several quality parameters. The breads with the greatest height were obtained with the quadruple combination of leuconostocs and weissellas. The highest softness was registered for the breads obtained from fermentations performed by W. cibaria PON10032 alone and in combination. The different inocula influenced also the color, the void fraction, the cell density and the mean cell area of the breads. Different levels of acids, alcohols, aldehydes, esters, hydrocarbons, ketones, terpenes, furans and phenol were emitted by the breads. The sensory tests indicated the breads from the sourdoughs fermented with the seven LAB inocula as sweeter and less acidic than control breads and the breads from the trials with the highest complexity of LAB inoculums were those more appreciated by tasters. A multivariate approach found strong differences among the trials. In particular, control breads and the breads obtained with different starter LAB were quite distant and a more

Lipid composition in a strain of Bacillus subtilis, a producer of iturin A lipopeptides that are active against uropathogenic bacteria.

PubMed

Bernat, Przemysław; Paraszkiewicz, Katarzyna; Siewiera, Paulina; Moryl, Magdalena; Płaza, Grażyna; Chojniak, Joanna

2016-10-01

Urinary tract infections are a common disease in humans. Therefore, new methods are needed to destroy biofilms that are formed by uropathogens. Iturin A lipopeptides (LPs) C14 and C15 are potent biosurfactants synthetized by the Bacillus subtilis I'1a strain. The biological activity of extracted LPs was confirmed by examining extracts from I'1a cultures against uropathogenic bacteria that had been isolated from biofilms on urinary catheters. Compared with cultures of DSM 3257, which produce surfactin at a relatively low level, the extract obtained from strain I'1a exhibited a greater inhibitory effect against both planktonic and sessile forms of Escherichia coli, Serratia marcescens, Enterobacter cloacae, Proteus mirabilis, Citrobacter freundii and Enterococcus faecalis. Moreover, cyclic LP biosurfactants may disturb the integrity of cytoplasmic membranes; therefore, we investigated the effects of synthetized LPs on fatty acids and phospholipids of B. subtilis. LPs and lipids were analyzed using GC-MS, LC-MS/MS and MALDI-TOF/TOF techniques. Compared with B. subtilis DSM 3257, membranes of the I'1a strain were characterized by an increased amount of anteiso fatty acids and a ten-fold higher ratio of phosphatidylglycerol (PG)-to-phosphatidylethanolamine (PE). Interestingly, in cultures of B. subtilis DSM 3257 supplemented with LP extracts of the I'1a strain, the PG-to-PE ratio was fourfold higher, and the amount of anteiso fatty acids was also increased.

Systems solutions by lactic acid bacteria: from paradigms to practice

PubMed Central

2011-01-01

Lactic acid bacteria are among the powerhouses of the food industry, colonize the surfaces of plants and animals, and contribute to our health and well-being. The genomic characterization of LAB has rocketed and presently over 100 complete or nearly complete genomes are available, many of which serve as scientific paradigms. Moreover, functional and comparative metagenomic studies are taking off and provide a wealth of insight in the activity of lactic acid bacteria used in a variety of applications, ranging from starters in complex fermentations to their marketing as probiotics. In this new era of high throughput analysis, biology has become big science. Hence, there is a need to systematically store the generated information, apply this in an intelligent way, and provide modalities for constructing self-learning systems that can be used for future improvements. This review addresses these systems solutions with a state of the art overview of the present paradigms that relate to the use of lactic acid bacteria in industrial applications. Moreover, an outlook is presented of the future developments that include the transition into practice as well as the use of lactic acid bacteria in synthetic biology and other next generation applications. PMID:21995776

Composition of lactic acid bacteria during spontaneous curly kale (Brassica oleracea var. sabellica) fermentation.

PubMed

Michalak, Magdalena; Gustaw, Klaudia; Waśko, Adam; Polak-Berecka, Magdalena

2018-01-01

The present work is the first report on spontaneous fermentation of curly kale and characteristics of autochthonous lactic acid bacteria (LAB). Our results indicate that curly kale fermentation is the new possibility of the technological use of this vegetable. Bacteria representing ten different species were isolated from three phases of curly kale fermentation and identified by MALDI-TOF mass spectrometry and 16S rRNA gene sequencing. Among them, four species were identified as Lactobacillus spp. (Lb. plantarum 332, Lb. paraplantarum G2114, Lb. brevis R413, Lb. curvatus 154), two as Weissella spp. (W. hellenica 152, W. cibaria G44), two as Pediococcus spp. (P. pentosaceus 45AN, P. acidilactici 2211), one as Leuconostoc mesenteroides 153, and one as Lactococcus lactis 37BN. The functional properties of isolates, i.e. acid, NaCl and bile salt tolerance, enzyme activities, adhesion to hydrocarbons, and antibiotic resistance, were examined. Among the tested strains, Lb. plantarum 332, Lb. paraplantarum G2114, P. pentosaceus 2211, and Lb. brevis R413 exhibited the best hydrophobicity value and high tolerance to bile salts, NaCl, and low pH. Copyright © 2017 Elsevier GmbH. All rights reserved.

Effect of milk fermentation by kefir grains and selected single strains of lactic acid bacteria on the survival of Mycobacterium bovis BCG.

PubMed

Macuamule, C L S; Wiid, I J; van Helden, P D; Tanner, M; Witthuhn, R C

2016-01-18

Mycobacterium bovis that causes Bovine tuberculosis (BTB) can be transmitted to humans thought consumption of raw and raw fermented milk products from diseased animals. Lactic acid bacteria (LAB) used in popular traditional milk products in Africa produce anti-microbial compounds that inhibit some pathogenic and spoilage bacteria. M. bovis BCG is an attenuated non-pathogenic vaccine strain of M. bovis and the aim of the study was to determine the effect of the fermentation process on the survival of M. bovis BCG in milk. M. bovis BCG at concentrations of 6 log CFU/ml was added to products of kefir fermentation. The survival of M. bovis BCG was monitored at 12-h intervals for 72 h by enumerating viable cells on Middlebrook 7H10 agar plates enriched with 2% BD BACTEC PANTA™. M. bovis BCG was increasingly reduced in sterile kefir that was fermented for a period of 24h and longer. In the milk fermented with kefir grains, Lactobacillus paracasei subsp. paracasei or Lactobacillus casei, the viability of M. bovis BCG was reduced by 0.4 logs after 24h and by 2 logs after 48 h of fermentation. No viable M. bovis BCG was detected after 60 h of fermentation. Results from this study show that long term fermentation under certain conditions may have the potential to inactivate M. bovis BCG present in the milk. However, to ensure safety of fermented milk in Africa, fermentation should be combined with other hurdle technologies such as boiling and milk pasteurisation. Copyright © 2015 Elsevier B.V. All rights reserved.

Screening of Lactobacillus strains for their ability to produce conjugated linoleic acid in milk and to adhere to the intestinal tract.

PubMed

Sosa-Castañeda, J; Hernández-Mendoza, A; Astiazarán-García, H; Garcia, H S; Estrada-Montoya, M C; González-Córdova, A F; Vallejo-Cordoba, B

2015-10-01

Conjugated linoleic acid (CLA) has been shown to provide beneficial effects on health; however, the amount consumed in food is far from that required for the desired effects. Thus, increasing the CLA content in dairy foods through milk fermentation with specific lactic acid bacteria (LAB) offers an interesting alternative. Moreover, some LAB may be able to adhere to the intestinal mucosa and produce CLA through endogenous synthesis. Therefore, the objective of this study was to screen LAB isolates for their ability to produce CLA in skim milk and in simulated gastrointestinal conditions. Additionally, the ability of selected CLA-producing LAB to adhere to the intestinal mucosa in a murine model was assessed. Results showed that of 13 strains of Lactobacillus tested, only 4 were able to produce CLA in skim milk supplemented with linoleic acid (13.44 ± 0.78 to 50.9 ± 0.26 µg/mL). Furthermore, these 4 Lactobacillus strains were able to survive and produce CLA in simulated gastrointestinal conditions and to adhere to the intestinal mucosa of Wistar rats after 7 d of oral inoculation with fluorescently labeled bacteria. Accordingly, these 4 Lactobacillus strains may be used to manufacture fermented dairy foods to increase CLA content, and consumption of these fermented milks may result in CLA produced endogenously by these LAB. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Solid state fermentation with lactic acid bacteria to improve the nutritional quality of lupin and soya bean.

PubMed

Bartkiene, Elena; Krungleviciute, Vita; Juodeikiene, Grazina; Vidmantiene, Daiva; Maknickiene, Zita

2015-04-01

The ability of bacteriocin-like inhibitory substance (BLIS)-producing lactic acid bacteria (LAB) to degrade biogenic amines as well as to produce L(+) and D(-)-lactic acid during solid state fermentation (SSF) of lupin and soya bean was investigated. In addition, the protein digestibility and formation of organic acids during SSF of legume were investigated. Protein digestibility of fermented lupin and soya bean was found higher on average by 18.3% and 15.9%, respectively, compared to untreated samples. Tested LAB produced mainly L-lactic acid in soya bean and lupin (D/L ratio 0.38-0.42 and 0.35-0.54, respectively), while spontaneous fermentation gave almost equal amounts of both lactic acid isomers (D/L ratio 0.82-0.98 and 0.92, respectively). Tested LAB strains were able to degrade phenylethylamine, spermine and spermidine, whereas they were able to produce putrescine, histamine and tyramine. SSF improved lupin and soya bean protein digestibility. BLIS-producing LAB in lupin and soya bean medium produced a mixture of D- and L-lactic acid with a major excess of the latter isomer. Most toxic histamine and tyramine in fermented lupin and soya bean were found at levels lower those causing adverse health effects. Selection of biogenic amines non-producing bacteria is essential in the food industry to avoid the risk of amine formation. © 2014 Society of Chemical Industry.

Stimulation of Lactic Acid Bacteria by a Micrococcus Isolate: Evidence for Multiple Effects

PubMed Central

Nath, K. R.; Wagner, B. J.

1973-01-01

Growth of, and rate of acid production by, six cultures of lactic acid bacteria were increased in the presence of Micrococcus isolate F4 or a preparation of its capsular material. Concentrations of hydrogen peroxide found in pure cultures of the lactic acid bacteria were not detectable, or were greatly reduced, in mixed culture with Micrococcus isolate F4. The capsular material was not as effective as whole cells in preventing accumulation of H2O2. Catalase stimulated growth of, and the rate of acid production by, the lactic acid bacteria, but not to the same extent as Micrococcus isolate F4 in some cultures. The existence of two mechanisms for micrococcal stimulation of the lactic acid bacteria is postulated. One mechanism involves removal of H2O2; the other has not been characterized. PMID:4199337

Biodegradation of chlorpyrifos by lactic acid bacteria during kimchi fermentation.

PubMed

Cho, Kye Man; Math, Reukaradhya K; Islam, Shah Md Asraful; Lim, Woo Jin; Hong, Su Young; Kim, Jong Min; Yun, Myoung Geun; Cho, Ji Joong; Yun, Han Dae

2009-03-11

We examined the role of microorganisms in the degradation of the organophosphorus (OP) insecticide chlorpyrifos (CP) during kimchi fermentation. During the fermentation of kimchi, 30 mg L(-1) of CP was added and its stability assayed during fermentation. CP was degraded rapidly until day 3 (83.3%) and degraded completely by day 9. Four CP-degrading lactic acid bacteria (LAB) were isolated from kimchi fermentation in the presence of 200 mg L(-1) CP and were identified as Leuconostoc mesenteroides WCP907, Lactobacillus brevis WCP902, Lactobacillus plantarum WCP931, and Lactobacillus sakei WCP904. CP could be utilized by these four strains as the sole source of carbon and phosphorus. Coumaphos (CM), diazinon (DZ), parathion (PT), and methylparathion (MPT) were also degraded by WCP907, WCP902, WCP931, and WCP904 when provided as sole sources of carbon and phosphorus.

Establishment of the first international repository for transfusion-relevant bacteria reference strains: ISBT working party transfusion-transmitted infectious diseases (WP-TTID), subgroup on bacteria.

PubMed

Störmer, M; Arroyo, A; Brachert, J; Carrero, H; Devine, D; Epstein, J S; Gabriel, C; Gelber, C; Goodrich, R; Hanschmann, K-M; Heath, D G; Jacobs, M R; Keil, S; de Korte, D; Lambrecht, B; Lee, C-K; Marcelis, J; Marschner, S; McDonald, C; McGuane, S; McKee, M; Müller, T H; Muthivhi, T; Pettersson, A; Radziwon, P; Ramirez-Arcos, S; Reesink, H W; Rojo, J; Rood, I; Schmidt, M; Schneider, C K; Seifried, E; Sicker, U; Wendel, S; Wood, E M; Yomtovian, R A; Montag, T

2012-01-01

Bacterial contamination of platelet concentrates (PCs) still remains a significant problem in transfusion with potential important clinical consequences, including death. The International Society of Blood Transfusion Working Party on Transfusion-Transmitted Infectious Diseases, Subgroup on Bacteria, organised an international study on Transfusion-Relevant Bacteria References to be used as a tool for development, validation and comparison of both bacterial screening and pathogen reduction methods. Four Bacteria References (Staphylococcus epidermidis PEI-B-06, Streptococcus pyogenes PEI-B-20, Klebsiella pneumoniae PEI-B-08 and Escherichia coli PEI-B-19) were selected regarding their ability to proliferate to high counts in PCs and distributed anonymised to 14 laboratories in 10 countries for identification, enumeration and bacterial proliferation in PCs after low spiking (0·3 and 0·03 CFU/ml), to simulate contamination occurring during blood donation. Bacteria References were correctly identified in 98% of all 52 identifications. S. pyogenes and E. coli grew in PCs in 11 out of 12 laboratories, and K. pneumoniae and S. epidermidis replicated in all participating laboratories. The results of bacterial counts were very consistent between laboratories: the 95% confidence intervals were for S. epidermidis: 1·19-1·32 × 10(7) CFU/ml, S. pyogenes: 0·58-0·69 × 10(7) CFU/ml, K. pneumoniae: 18·71-20·26 × 10(7) CFU/ml and E. coli: 1·78-2·10 × 10(7) CFU/ml. The study was undertaken as a proof of principle with the aim to demonstrate (i) the quality, stability and suitability of the bacterial strains for low-titre spiking of blood components, (ii) the property of donor-independent proliferation in PCs, and (iii) their suitability for worldwide shipping of deep frozen, blinded pathogenic bacteria. These aims were successfully fulfilled. The WHO Expert Committee Biological Standardisation has approved the adoption of these four bacteria strains as the first

Detection of arc genes related with the ethyl carbamate precursors in wine lactic acid bacteria.

PubMed

Araque, Isabel; Gil, Joana; Carreté, Ramon; Bordons, Albert; Reguant, Cristina

2009-03-11

Trace amounts of the carcinogen ethyl carbamate can appear in wine by the reaction of ethanol with compounds such as citrulline and carbamyl phosphate, which are produced from arginine degradation by some wine lactic acid bacteria (LAB). In this work, the presence of arc genes for the arginine-deiminase pathway was studied in several strains of different species of LAB. Their ability to degrade arginine was also studied. To detect the presence of arc genes, degenerate primers were designed from the alignment of protein sequences in already sequenced LAB. The usefulness of these degenerate primers has been proven by sequencing some of the amplified PCR fragments and searching for homologies with published sequences of the same species and related ones. Correlation was found between the presence of genes and the ability to degrade arginine. Degrading strains included all heterofermentative lactobacilli, Oenococcus oeni , Pediococcus pentosaceus , and some strains of Leuconostoc mesenteroides and Lactobacillus plantarum .

Deoxyribonucleic acid-deficient strains of Candida albicans.

PubMed

Olaiya, A F; Steed, J R; Sogin, S J

1980-03-01

We analyzed a series of germ tube-negative variants isolated from Candida albicans 3153A for deoxyribonucleic acid content. As analyzed by flow microfluorometry, the deoxyribonucleic acid level in these variant strains was 50% of that of the parental strain and equivalent to that of haploid Saccharomyces cerevisiae. This finding was confirmed by comparison of survival rates when exposed to the mutagens ultraviolet light, ethyl methane sulfonate, and methyl methane sulfonate. The diameter of the variant cells as compared to the diameter of the parental 3153A strain showed a relationship similar to that of the diameters of haploid versus diploid S. cerevisiae. These results indicate that those strains may be representative of the imperfect stage of C. albicans.

Thermotolerance of meat spoilage lactic acid bacteria and their inactivation in vacuum-packaged vienna sausages.

PubMed

Franz, C M; von Holy, A

1996-02-01

Heat resistance of three meat spoilage lactic acid bacteria was determined in vitro. D-values at 57, 60 and 63 degrees C were 52.9, 39.3 and 32.5 s for Lactobacillus sake, 34.9, 31.3 and 20.2 s for Leuconostoc mesenteroides and 22.5, 15.6 and 14.4 s for Lactobacillus curvatus, respectively. The three lactic acid bacteria were heat sensitive, as one log reductions in numbers were achieved at 57 degrees C in less than 60 s. Z-values could not be accurately determined as D-values did not change by a factor of 10 over the temperature range studied. In-package pasteurization processes were calculated using the highest in vitro D-value and applied to vacuum-packaged vienna sausages. Microbiological shelf life (time for lactic acid bacteria count to reach 5 x 10(6) CFU/g) increased from 7 days for non-pasteurized samples to 67, 99 and 119 days for samples of the three pasteurization treatments at 8 degrees C storage. Enterobacteriaceae were detected at levels of log 4.0 CFU/g in non-pasteurized samples, but were reduced to < log 1.0 CFU/g in pasteurized samples. The incidence of listeriae in non-pasteurized samples was low as only one Listeria innocua strain was isolated. No Listeria spp. were isolated from pasteurized samples. Numbers of Clostridium isolates increased from one in non-pasteurized samples to 25 in pasteurized samples. Increasing incidences of clostridia, and the presence of C. perfringens in pasteurized samples indicated that in-package pasteurization could compromise product safety.

Improving survival of probiotic bacteria using bacterial poly-γ-glutamic acid.

PubMed

Bhat, A R; Irorere, V U; Bartlett, T; Hill, D; Kedia, G; Charalampopoulos, D; Nualkaekul, S; Radecka, I

2015-03-02

A major hurdle in producing a useful probiotic food product is bacterial survival during storage and ingestion. The aim of this study was to test the effect of γ-PGA immobilisation on the survival of probiotic bacteria when stored in acidic fruit juice. Fruit juices provide an alternative means of probiotic delivery, especially to lactose intolerant individuals. In addition, the survival of γ-PGA-immobilised cells in simulated gastric juice was also assessed. Bifidobacteria strains (Bifidobacteria longum, Bifidobacteria breve), immobilised on 2.5% γ-PGA, survived significantly better (P<0.05) in orange and pomegranate juice for 39 and 11 days respectively, compared to free cells. However, cells survived significantly better (P<0.05) when stored in orange juice compared to pomegranate juice. Moreover, both strains, when protected with 2.5% γ-PGA, survived in simulated gastric juice (pH2.0) with a marginal reduction (<0.47 log CFU/ml) or no significant reduction in viable cells after 4h, whereas free cells died within 2h. In conclusion, this research indicates that γ-PGA can be used to protect Bifidobacteria cells in fruit juice, and could also help improve the survival of cells as they pass through the harsh conditions of the gastrointestinal tract (GIT). Following our previous report on the use of γ-PGA as a cryoprotectant for probiotic bacteria, this research further suggests that γ-PGA could be used to improve probiotic survival during the various stages of preparation, storage and ingestion of probiotic cells. Copyright © 2014 Elsevier B.V. All rights reserved.

Biodiversity and γ-Aminobutyric Acid Production by Lactic Acid Bacteria Isolated from Traditional Alpine Raw Cow's Milk Cheeses

PubMed Central

Nardin, Tiziana; Schiavon, Silvia; Cavazza, Agostino; Larcher, Roberto; Tuohy, Kieran M.

2015-01-01

“Nostrano-cheeses” are traditional alpine cheeses made from raw cow's milk in Trentino-Alto Adige, Italy. This study identified lactic acid bacteria (LAB) developing during maturation of “Nostrano-cheeses” and evaluated their potential to produce γ-aminobutyric acid (GABA), an immunologically active compound and neurotransmitter. Cheese samples were collected on six cheese-making days, in three dairy factories located in different areas of Trentino and at different stages of cheese ripening (24 h, 15 days, and 1, 2, 3, 6, and 8 months). A total of 1,059 LAB isolates were screened using Random Amplified Polymorphic DNA-PCR (RAPD-PCR) and differentiated into 583 clusters. LAB strains from dominant clusters (n = 97) were genetically identified to species level by partial 16S rRNA gene sequencing. LAB species most frequently isolated were Lactobacillus paracasei, Streptococcus thermophilus, and Leuconostoc mesenteroides. The 97 dominant clusters were also characterized for their ability in producing GABA by high-performance liquid chromatography (HPLC). About 71% of the dominant bacteria clusters evolving during cheeses ripening were able to produce GABA. Most GABA producers were Lactobacillus paracasei but other GABA producing species included Lactococcus lactis, Lactobacillus plantarum, Lactobacillus rhamnosus, Pediococcus pentosaceus, and Streptococcus thermophilus. No Enterococcus faecalis or Sc. macedonicus isolates produced GABA. The isolate producing the highest amount of GABA (80.0±2.7 mg/kg) was a Sc. thermophilus. PMID:25802859

Biodiversity and γ-aminobutyric acid production by lactic acid bacteria isolated from traditional alpine raw cow's milk cheeses.

PubMed

Franciosi, Elena; Carafa, Ilaria; Nardin, Tiziana; Schiavon, Silvia; Poznanski, Elisa; Cavazza, Agostino; Larcher, Roberto; Tuohy, Kieran M

2015-01-01

"Nostrano-cheeses" are traditional alpine cheeses made from raw cow's milk in Trentino-Alto Adige, Italy. This study identified lactic acid bacteria (LAB) developing during maturation of "Nostrano-cheeses" and evaluated their potential to produce γ-aminobutyric acid (GABA), an immunologically active compound and neurotransmitter. Cheese samples were collected on six cheese-making days, in three dairy factories located in different areas of Trentino and at different stages of cheese ripening (24 h, 15 days, and 1, 2, 3, 6, and 8 months). A total of 1,059 LAB isolates were screened using Random Amplified Polymorphic DNA-PCR (RAPD-PCR) and differentiated into 583 clusters. LAB strains from dominant clusters (n = 97) were genetically identified to species level by partial 16S rRNA gene sequencing. LAB species most frequently isolated were Lactobacillus paracasei, Streptococcus thermophilus, and Leuconostoc mesenteroides. The 97 dominant clusters were also characterized for their ability in producing GABA by high-performance liquid chromatography (HPLC). About 71% of the dominant bacteria clusters evolving during cheeses ripening were able to produce GABA. Most GABA producers were Lactobacillus paracasei but other GABA producing species included Lactococcus lactis, Lactobacillus plantarum, Lactobacillus rhamnosus, Pediococcus pentosaceus, and Streptococcus thermophilus. No Enterococcus faecalis or Sc. macedonicus isolates produced GABA. The isolate producing the highest amount of GABA (80.0±2.7 mg/kg) was a Sc. thermophilus.

Generation of volatile fatty acids by axillary bacteria.

PubMed

James, A G; Hyliands, D; Johnston, H

2004-06-01

It is generally accepted that short-chain (C(2)-C(5)) volatile fatty acids (VFAs) are among the causal molecules of axillary malodour. It is also widely acknowledged that malodour generation is attributable to the biotransformation of odourless natural secretions, into volatile odorous products, by axillary bacteria. However, little information is available on the biochemical origins of VFAs on axillary skin. In these studies, assay systems were developed to investigate the generation of VFAs from substrates readily available to the bacteria resident on axillary skin. Propionibacteria and staphylococci were shown to ferment glycerol and lactic acid to the short-chain (C(2)-C(3)) VFAs, acetic and propionic acid. Furthermore, staphylococci are capable of converting branched aliphatic amino acids, such as leucine, to highly odorous short-chain (C(4)-C(5)) methyl-branched VFAs, such as isovaleric acid, which are traditionally associated with the acidic note of axillary malodour. However, in vitro kinetic data indicates that these pathways contribute less to axillary VFA levels, than fatty acid biotransformations by a recently defined sub-group of the Corynebacterium genus, corynebacteria (A). The results of these studies provide new understanding on the biochemical origins of VFA-based axillary malodour which, in turn, should lead to the development of novel deodorant systems.

Isolation of lactic acid bacteria with potential protective culture characteristics from fruits

NASA Astrophysics Data System (ADS)

Hashim, Nurul Huda; Sani, Norrakiah Abdullah

2015-09-01

Lactic acid bacteria are also known as beneficial microorganisms abundantly found in fermented food products. In this study, lactic acid bacteria were isolated from fresh cut fruits obtained from local markets. Throughout the isolation process from 11 samples of fruits, 225 presumptive lactic acid bacteria were isolated on MRS agar medium. After catalase and oxidase tests, 149 resulted to fit the characteristics of lactic acid bacteria. Further identification using Gram staining was conducted to identify the Gram positive bacteria. After this confirmation, the fermentation characteristics of these isolates were identified. It was found that 87 (58.4%) isolates were heterofermentative, while the rest of 62 (41.6%) are homofermentative lactic acid bacteria. Later, all these isolates were investigated for the ability to inhibit growth of Staphylococcus aureus using agar spot assay method. Seven (4.7%) isolates showed strong antagonistic capacity, while 127 (85.2%) and 8 (5.4%) isolates have medium and weak antagonistic capacity, respectively. The other 7 (4.7%) isolates indicated to have no antagonistic effect on S. aureus. Results support the potential of LAB isolated in this study which showed strong antagonistic activity against S. aureus may be manipulated to become protective cultures in food products. While the homofermentative or heterofermentative LAB can be utilized in fermentation of food and non-food products depending on the by-products required during the fermentation.

In vitro study of beneficial properties and safety of lactic acid bacteria isolated from Portuguese fermented meat products.

PubMed

Todorov, S D; Franco, B D G M; Wiid, I J

2014-09-01

Many lactic acid bacteria produce bacteriocins with a rather broad spectrum of inhibition, which could offer potential applications in food preservation. Bacteriocin production by starter cultures may bring advantage to these strains in competitive interactions with pathogenic bacteria from the food matrix. The objective of this study was to determine the safety of beneficial strains (Lactobacillus plantarum ST202Ch and ST216Ch, Enterococcus faecium ST211Ch, and Lactobacillus sakei ST22Ch, ST153Ch and ST154Ch) previously isolated from fermented meat products and characterised as bacteriocin producers. Auto-aggregation was strain-specific, and values of 28.97, 27.86 and 28.56% were recorded for L. sakei ST22Ch, ST153Ch and ST154Ch, respectively, 16.95 and 14.58% for L. plantarum ST202Ch and ST216Ch, respectively, and 12.77% for E. faecium ST211Ch. Various degrees of co-aggregation between 28.85 and 44.76% for Listeria monocytogenes 211 and 409, and between 23.60 to 34.96% for E. faecium ATCC 19443 were observed. According to the results of the diffusion method, the studied strains demonstrated susceptibility to penicillin G, ampicillin, amoxicillin, amoxicillin/clavulonic acid, imipenem, linezolid, and tetracycline. In addition, the susceptibility of the six strains to various non-antibiotic commercial drugs was examined. Production of β-galactosidase by L. sakei ST22Ch, ST153Ch and ST154Ch, L. plantarum ST202Ch and ST216Ch, and E. faecium ST211Ch was confirmed by employing sterile filter paper discs impregnated with o-nitrophenyl-β-D-galactopyranose. A statistically significant (P<0.001) inhibition of Mycobacterium tuberculosis growth by bacteriocins produced by L. plantarum ST202Ch (38.3%) and ST216Ch (48.6%), L. sakei ST153Ch (16.2%) and ST154Ch (16.1%), and E. faecium ST211Ch (21.7%) was observed. As determined by the polymerase chain reaction, the tested strains showed a low virulence gene profile.

Purification of bacteriocins produced by lactic acid bacteria.

PubMed

Saavedra, Lucila; Castellano, Patricia; Sesma, Fernando

2004-01-01

Bacteriocins are antibacterial substances of a proteinaceous nature that are produced by different bacterial species. Lactic acid bacteria (LAB) produce biologically active peptides or protein complexes that display a bactericidal mode of action almost exclusively toward Gram-positive bacteria and particularly toward closely related species. Generally they are active against food spoilage and foodborne pathogenic microorganisms including Bacillus cereus, Clostridium perfringens, Staphylococcus aureus, and Listeria monocytogenes. There is an increased tendency to use natural occurring metabolites to prevent the growth of undesirable flora in foodstuffs. These metabolites could replace the use of chemical additives such as sorbic acid, sulfur dioxide, nitrite, nitrate, and others. For instance, bacteriocins produced by LAB may be promising for use as bio-preservaties. Bacteriocins of lactic acid bacteria are typically cationic, hydrophobic peptides and differ widely in many characteristics including molecular weight, presence of particular groups of amino acids, pI, net positive charge, and post-translational modifications of certain amino acids. This heterogeneity within the LAB bacteriocins may explain the different procedures for isolation and purification developed so far. The methods most frequently used for isolation, concentration, and purification involve salt precipitation of bacteriocins from culture supernatants, followed by various combinations of gel filtration, ion-exchange chromatography, and reverse-phase high-performance liquid chromatography (RP-HPLC). In this chapter, a protocol is described that combines several methods used in our laboratory for the purification of two cationic bacteriocins, Lactocin 705AL and Enterocin CRL10, produced by Lactobacillus casei CRL705 and Enterococcus mundtii CRL10, respectively.

Isolation and partial characterization of halotolerant lactic acid bacteria from two Mexican cheeses.

PubMed

Morales, Fredy; Morales, Jesús I; Hernández, César H; Hernández-Sánchez, Humberto

2011-07-01

Isolated strains of halotolerant or halophilic lactic acid bacteria (HALAB) from Cotija and doble crema cheeses were identified and partially characterized by phenotypic and genotypic methods, and their technological abilities were studied in order to test their potential use as dairy starter components. Humidity, a(w), pH, and salt concentration of cheeses were determined. Genotypic diversity was evaluated by randomly amplified polymorphic DNA-polymerase chain reaction. Molecular identification and phylogenetic reconstructions based on 16S rRNA gene sequences were performed. Additional technological abilities such as salt tolerance, acidifying, and proteolytic and lipolytic activities were also investigated. The differences among strains reflected the biodiversity of HALAB in both types of cheeses. Lactobacillus acidipiscis, Tetragenococcus halophilus, Weissella thailandensis, and Lactobacillus pentosus from Cotija cheese, and L. acidipiscis, Enterococcus faecium, Lactobacillus plantarum, Lactobacillus farciminis, and Lactobacillus rhamnosus from doble crema cheese were identified based on 16S rRNA. Quantitative and qualitative assessments showed strains of T. halophilus and L. plantarum to be proteolytic, along with E. faecium, L. farciminis, and L. pentosus to a lesser extent. Lipolytic activity could be demonstrated in strains of E. faecium, L. pentosus, L. plantarum, and T. halophilus. Strains belonging to the species L. pentosus, L. plantarum, and E. faecium were able to acidify the milk media. This study evidences the presence of HALAB that may play a role in the ripening of cheeses.

Isolation of Endotoxin Eliminating Lactic Acid Bacteria and a Property of Endotoxin Eliminating Protein.

PubMed

Kondo, Ayaka; Asami, Kyoko; Suda, Yoshihito; Shimoyamada, Makoto; Kanauchi, Makoto

2016-06-01

Recently, many scholars have reported lactic acid bacteria (LAB) functions, such as anticancer activity and anti-inflammatory activity for intestines. To decrease inflammatory substances such as endotoxins, LAB consumed safely with meals were isolated from food and food ingredients. First, LAB were isolated as 168 strains of bacillus LAB (49 strain) and coccus LAB (119 strains) from food ingredients and fermented foods such as rice, rice bran, malt, grains, miso soy paste, and some pickles. Their LAB (168 strains) were cultivated in medium containing endotoxin from Escherichia coli O18 LPS at 15 and 30 °C for 64 h to identify endotoxin-eliminating LAB. Consequently, the AK-23 strain was screened as an endotoxin-eliminating LAB strain. The strain decreased endotoxin in YP medium without sugar at 30 °C for 64 h until 9% of endotoxin. The strain was identified as Pediococcus pentosaceus according to morphological characteristics such as its cell shape, physiological characteristics related to its fermentation type, assimilation of sugars, pH tolerance, optimum growth temperature, and molecular biological characteristics as its homology to 16S rRNA. To investigate the location of the endotoxin-eliminating substance, 4 fractions were separated from AK-23 cells as extracellular, cell wall digestion, cytoplasm, and cell membrane fractions. The endotoxin-decreasing substance, located on a cell wall, was identified as a 217 kDa protein. © 2016 Institute of Food Technologists®

New potentially antihypertensive peptides liberated in milk during fermentation with selected lactic acid bacteria and kombucha cultures.

PubMed

Elkhtab, Ebrahim; El-Alfy, Mohamed; Shenana, Mohamed; Mohamed, Abdelaty; Yousef, Ahmed E

2017-12-01

Compounds with the ability to inhibit angiotensin-converting enzyme (ACE) are used medically to treat human hypertension. The presence of such compounds naturally in food is potentially useful for treating the disease state. The goal of this study was to screen lactic acid bacteria, including species commonly used as dairy starter cultures, for the ability to produce new potent ACE-inhibiting peptides during milk fermentation. Strains of Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus delbrueckii ssp. bulgaricus, Lactobacillus helveticus, Lactobacillus paracasei, Lactococcus lactis, Leuconostoc mesenteroides, and Pediococcus acidilactici were tested in this study. Additionally, a symbiotic consortium of yeast and bacteria, used commercially to produce kombucha tea, was tested. Commercially sterile milk was inoculated with lactic acid bacteria strains and kombucha culture and incubated at 37°C for up to 72 h, and the liberation of ACE-inhibiting compounds during fermentation was monitored. Fermented milk was centrifuged and the supernatant (crude extract) was subjected to ultrafiltration using 3- and 10-kDa cut-off filters. Crude and ultrafiltered extracts were tested for ACE-inhibitory activity. The 10-kDa filtrate resulting from L. casei ATCC 7469 and kombucha culture fermentations (72 h) showed the highest ACE-inhibitory activity. Two-step purification of these filtrates was done using HPLC equipped with a reverse-phase column. Analysis of HPLC-purified fractions by liquid chromatography-mass spectrometry/mass spectrometry identified several new peptides with potent ACE-inhibitory activities. Some of these peptides were synthesized, and their ACE-inhibitory activities were confirmed. Use of organisms producing these unique peptides in food fermentations could contribute positively to human health. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Microbial Degradation of Chlorogenic Acid by a Sphingomonas sp. Strain.

PubMed

Ma, Yuping; Wang, Xiaoyu; Nie, Xueling; Zhang, Zhan; Yang, Zongcan; Nie, Cong; Tang, Hongzhi

2016-08-01

In order to elucidate the metabolism of chlorogenic acid by environmental microbes, a strain of Sphingomonas sp. isolated from tobacco leaves was cultured under various conditions, and chlorogenic acid degradation and its metabolites were investigated. The strain converting chlorogenic acid was newly isolated and identified as a Sphingomonas sp. strain by 16S rRNA sequencing. The optimal conditions for growth and chlorogenic acid degradation were 37 °C and pH 7.0 with supplementation of 1.5 g/l (NH4)2SO4 as the nitrogen source and 2 g/l chlorogenic acid as the sole carbon source. The maximum chlorogenic acid tolerating capability for the strain was 5 g/l. The main metabolites were identified as caffeic acid, shikimic acid, and 3,4-dihydroxybenzoic acid based on gas chromatography-mass spectrometry analysis. The analysis reveals the biotransformation mechanism of chlorogenic acid in microbial cells isolated from the environment.

Acid-tolerant microaerophilic Fe(II)-oxidizing bacteria promote Fe(III)-accumulation in a fen.

PubMed

Lüdecke, Claudia; Reiche, Marco; Eusterhues, Karin; Nietzsche, Sandor; Küsel, Kirsten

2010-10-01

The ecological importance of Fe(II)-oxidizing bacteria (FeOB) at circumneutral pH is often masked in the presence of O(2) where rapid chemical oxidation of Fe(II) predominates. This study addresses the abundance, diversity and activity of microaerophilic FeOB in an acidic fen (pH ∼ 5) located in northern Bavaria, Germany. Mean O(2) penetration depth reached 16 cm where the highest dissolved Fe(II) concentrations (up to 140 µM) were present in soil water. Acid-tolerant FeOB cultivated in gradient tubes were most abundant (10(6) cells g(-1) peat) at the 10-20 cm depth interval. A stable enrichment culture was active at up to 29% O(2) saturation and Fe(III) accumulated 1.6 times faster than in abiotic controls. An acid-tolerant, microaerophilic isolate (strain CL21) was obtained which was closely related to the neutrophilic, lithoautotrophic FeOB Sideroxydans lithotrophicus strain LD-1. CL21 oxidized Fe(II) between pH 4 and 6.0, and produced nanoscale-goethites with a clearly lower mean coherence length (7 nm) perpendicular to the (110) plane than those formed abiotically (10 nm). Our results suggest that an acid-tolerant population of FeOB is thriving at redox interfaces formed by diffusion-limited O(2) transport in acidic peatlands. Furthermore, this well-adapted population is successfully competing with chemical oxidation and thereby playing an important role in the microbial iron cycle. © 2010 Society for Applied Microbiology and Blackwell Publishing Ltd.

[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.

Genomic and Transcriptomic Analysis of Escherichia coli Strains Associated with Persistent and Transient Bovine Mastitis and the Role of Colanic Acid.

PubMed

Lippolis, John D; Holman, Devin B; Brunelle, Brian W; Thacker, Tyler C; Bearson, Bradley L; Reinhardt, Timothy A; Sacco, Randy E; Casey, Thomas A

2018-01-01

Escherichia coli is a leading cause of bacterial mastitis in dairy cattle. It is most often transient in nature, causing an infection that lasts 2 to 3 days. However, E. coli has been shown to cause a persistent infection in a minority of cases. Mechanisms that allow for a persistent E. coli infection are not fully understood. The goal of this work was to determine differences between E. coli strains originally isolated from dairy cattle with transient and persistent mastitis. Using RNA sequencing, we show gene expression differences in nearly 200 genes when bacteria from the two clinical phenotypes are compared. We sequenced the genomes of the E. coli strains and report genes unique to the two phenotypes. Differences in the wca operon, which encodes colanic acid, were identified by DNA as well as RNA sequencing and differentiated the two phenotypes. Previous work demonstrated that E. coli strains that cause persistent infections were more motile than those that cause transient infections. Deletion of genes in the wca operon from a persistent-infection strain resulted in a reduction of motility as measured in swimming and swarming assays. Furthermore, colanic acid has been shown to protect bacteria from complement-mediated killing. We show that transient-infection E. coli strains were more sensitive to complement-mediated killing. The deletion of genes from the wca operon caused a persistent-infection E. coli strain to become sensitive to complement-mediated killing. This work identifies important differences between E. coli strains that cause persistent and transient mammary infections in dairy cattle. This is a work of the U.S. Government and is not subject to copyright protection in the United States. Foreign copyrights may apply.

Novel 2,4-Dichlorophenoxyacetic Acid Degradation Genes from Oligotrophic Bradyrhizobium sp. Strain HW13 Isolated from a Pristine Environment

PubMed Central

Kitagawa, Wataru; Takami, Sachiko; Miyauchi, Keisuke; Masai, Eiji; Kamagata, Yoichi; Tiedje, James M.; Fukuda, Masao

2002-01-01

The tfd genes of Ralstonia eutropha JMP134 are the only well-characterized set of genes responsible for 2,4-dichlorophenoxyacetic acid (2,4-D) degradation among 2,4-D-degrading bacteria. A new family of 2,4-D degradation genes, cadRABKC, was cloned and characterized from Bradyrhizobium sp. strain HW13, a strain that was isolated from a buried Hawaiian soil that has never experienced anthropogenic chemicals. The cadR gene was inferred to encode an AraC/XylS type of transcriptional regulator from its deduced amino acid sequence. The cadABC genes were predicted to encode 2,4-D oxygenase subunits from their deduced amino acid sequences that showed 46, 44, and 37% identities with the TftA and TftB subunits of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) oxygenase of Burkholderia cepacia AC1100 and with a putative ferredoxin, ThcC, of Rhodococcus erythropolis NI86/21, respectively. They are thoroughly different from the 2,4-D dioxygenase gene, tfdA, of R. eutropha JMP134. The cadK gene was presumed to encode a 2,4-D transport protein from its deduced amino acid sequence that showed 60% identity with the 2,4-D transporter, TfdK, of strain JMP134. Sinorhizobium meliloti Rm1021 cells containing cadRABKC transformed several phenoxyacetic acids, including 2,4-D and 2,4,5-T, to corresponding phenol derivatives. Frameshift mutations indicated that each of the cadRABC genes was essential for 2,4-D conversion in strain Rm1021 but that cadK was not. Five 2,4-D degraders, including Bradyrhizobium and Sphingomonas strains, were found to have cadA gene homologs, suggesting that these 2,4-D degraders share 2,4-D degradation genes similar to those of strain HW13 cadABC. PMID:11751829

Interactions between Cooccurring Lactic Acid Bacteria in Honey Bee Hives

PubMed Central

Rokop, Z. P.; Horton, M. A.

2015-01-01

In contrast to the honey bee gut, which is colonized by a few characteristic bacterial clades, the hive of the honey bee is home to a diverse array of microbes, including many lactic acid bacteria (LAB). In this study, we used culture, combined with sequencing, to sample the LAB communities found across hive environments. Specifically, we sought to use network analysis to identify microbial hubs sharing nearly identical operational taxonomic units, evidence which may indicate cooccurrence of bacteria between environments. In the process, we identified interactions between noncore bacterial members (Fructobacillus and Lactobacillaceae) and honey bee-specific “core” members. Both Fructobacillus and Lactobacillaceae colonize brood cells, bee bread, and nectar and may serve the role of pioneering species, establishing an environment conducive to the inoculation by honey bee core bacteria. Coculture assays showed that these noncore bacterial members promote the growth of honey bee-specific bacterial species. Specifically, Fructobacillus by-products in spent medium supported the growth of the Firm-5 honey bee-specific clade in vitro. Metabolic characterization of Fructobacillus using carbohydrate utilization assays revealed that this strain is capable of utilizing the simple sugars fructose and glucose, as well as the complex plant carbohydrate lignin. We tested Fructobacillus for antibiotic sensitivity and found that this bacterium, which may be important for establishment of the microbiome, is sensitive to the commonly used antibiotic tetracycline. Our results point to the possible significance of “noncore” and environmental microbial community members in the modulation of honey bee microbiome dynamics and suggest that tetracycline use by beekeepers should be limited. PMID:26253685

Identification and characterization of the dominant lactic acid bacteria isolated from traditional fermented milk in Mongolia.

PubMed

Sun, Z H; Liu, W J; Zhang, J C; Yu, J; Gao, W; Jiri, M; Menghe, B; Sun, T S; Zhang, H P

2010-05-01

Five samples of Airag and 20 of Tarag (both in Mongolia) were collected from scattered households. One hundred strains of lactic acid bacteria (LAB) were isolated and identified from these samples according to phenotypic characterization and 16S rRNA gene sequence analysis. Eighty-five isolates belonged to the genus Lactobacillus, 15 being classified as coccoid LAB. All isolates belonged to 5 genera and 11 to different species and subspecies. Lactobacillus (Lb.) helveticus was predominant population in Airag samples, Lb. fermentum and Lb. helveticus were the major LAB microflora in Tarag.

Resolving bacterial contamination of fuel ethanol fermentations with beneficial bacteria - An alternative to antibiotic treatment.

PubMed

Rich, Joseph O; Bischoff, Kenneth M; Leathers, Timothy D; Anderson, Amber M; Liu, Siqing; Skory, Christopher D

2018-01-01

Fuel ethanol fermentations are not performed under aseptic conditions and microbial contamination reduces yields and can lead to costly "stuck fermentations". Antibiotics are commonly used to combat contaminants, but these may persist in the distillers grains co-product. Among contaminants, it is known that certain strains of lactic acid bacteria are capable of causing stuck fermentations, while other strains appear to be harmless. However, it was not previously known whether or how these strains interact one with another. In this study, more than 500 harmless strains of lactic acid bacteria were tested in a model system in combination with strains that cause stuck fermentations. Among these harmless strains, a group of beneficial strains was identified that restored ethanol production to near normal levels. Such beneficial strains may serve as an alternative approach to the use of antibiotics in fuel ethanol production. Published by Elsevier Ltd.

Lactic acid bacteria inhibit TH2 cytokine production by mononuclear cells from allergic patients.

PubMed

Pochard, Pierre; Gosset, Philippe; Grangette, Corinne; Andre, Claude; Tonnel, André-Bernard; Pestel, Joël; Mercenier, Annick

2002-10-01

Among factors potentially involved in the increased prevalence of allergic diseases, modification of the intestinal bacteria flora or lack of bacterial stimulation during childhood has been proposed. Lactic acid bacteria (LAB) present in fermented foods or belonging to the natural intestinal microflora were shown to exert beneficial effects on human health. Recent reports have indicated their capacity to reduce allergic symptoms. The purpose of this investigation was to determine the effect of LAB on the production of type 2 cytokines, which characterize allergic diseases. PBMCs from patients allergic to house dust mite versus those from healthy donors were stimulated for 48 hours with the related Dermatophagoides pteronyssinus allergen or with a staphylococcal superantigen. The effect of LAB preincubation was assessed by measuring the type 2 cytokine production by means of specific ELISA. The tested gram-positive LAB were shown to inhibit the secretion of T(H)2 cytokines (IL-4 and IL-5). This effect was dose dependent and was observed irrespective of the LAB strain used. No significant inhibition was induced by the control, gram-negative Escherichia coli TG1. Interestingly, LAB reduced the T(H)2 cytokine production from allergic PBMCs specifically restimulated with the related allergen. The inhibition mechanism was shown to be dependent on antigen-presenting cells (ie, monocytes) and on the involvement of IL-12 and IFN-gamma. The tested LAB strains were demonstrated to exhibit an anti-T(H)2 activity, and thus different strains of this family might be useful in the prevention of allergic diseases.

Diversity of lactic acid bacteria associated with traditional fermented dairy products in Mongolia.

PubMed

Yu, J; Wang, W H; Menghe, B L G; Jiri, M T; Wang, H M; Liu, W J; Bao, Q H; Lu, Q; Zhang, J C; Wang, F; Xu, H Y; Sun, T S; Zhang, H P

2011-07-01

Spontaneous milk fermentation has a long history in Mongolia, and beneficial microorganisms have been handed down from one generation to the next for use in fermented dairy products. The objective of this study was to investigate the diversity of lactic acid bacteria (LAB) communities in fermented yak, mare, goat, and cow milk products by analyzing 189 samples collected from 13 different regions in Mongolia. The LAB counts in these samples varied from 3.41 to 9.03 log cfu/mL. Fermented yak and mare milks had almost identical mean numbers of LAB, which were significantly higher than those in fermented goat milk but slightly lower than those in fermented cow milk. In total, 668 isolates were obtained from these samples using de Man, Rogosa, and Sharpe agar and M17 agar. Each isolate was considered to be presumptive LAB based on gram-positive and catalase-negative properties, and was identified at the species level by 16S rRNA gene sequencing, multiplex PCR assay, and restriction fragment length polymorphism analysis. All isolates from Mongolian dairy products were accurately identified as Enterococcus faecalis (1 strain), Enterococcus durans (3 strains), Lactobacillus brevis (3 strains), Lactobacillus buchneri (2 strains), Lactobacillus casei (16 strains), Lactobacillus delbrueckii ssp. bulgaricus (142 strains), Lactobacillus diolivorans (17 strains), Lactobacillus fermentum (42 strains), Lactobacillus helveticus (183 strains), Lactobacillus kefiri (6 strains), Lactobacillus plantarum ssp. plantarum (7 strains), Lactococcus lactis ssp. lactis (7 strains), Leuconostoc lactis (22 strains), Leuconostoc mesenteroides (21 strains), Streptococcus thermophilus (195 strains), and Weissella cibaria (1 strain). The predominant LAB were Strep. thermophilus and Lb. helveticus, which were isolated from all sampling sites. The results demonstrate that traditional fermented dairy products from different regions of Mongolia have complex compositions of LAB species. Such diversity of

10-oxo-12(Z)-octadecenoic acid, a linoleic acid metabolite produced by gut lactic acid bacteria, potently activates PPARγ and stimulates adipogenesis

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

Goto, Tsuyoshi, E-mail: tgoto@kais.kyoto-u.ac.jp; Research Unit for Physiological Chemistry, The Center for the Promotion of Interdisciplinary Education and Research, Kyoto University; Kim, Young-Il

2015-04-17

Our previous study has shown that gut lactic acid bacteria generate various kinds of fatty acids from polyunsaturated fatty acids such as linoleic acid (LA). In this study, we investigated the effects of LA and LA-derived fatty acids on the activation of peroxisome proliferator-activated receptors (PPARs) which regulate whole-body energy metabolism. None of the fatty acids activated PPARδ, whereas almost all activated PPARα in luciferase assays. Two fatty acids potently activated PPARγ, a master regulator of adipocyte differentiation, with 10-oxo-12(Z)-octadecenoic acid (KetoA) having the most potency. In 3T3-L1 cells, KetoA induced adipocyte differentiation via the activation of PPARγ, and increasedmore » adiponectin production and insulin-stimulated glucose uptake. These findings suggest that fatty acids, including KetoA, generated in gut by lactic acid bacteria may be involved in the regulation of host energy metabolism. - Highlights: • Most LA-derived fatty acids from gut lactic acid bacteria potently activated PPARα. • Among tested fatty acids, KetoA and KetoC significantly activated PPARγ. • KetoA induced adipocyte differentiation via the activation of PPARγ. • KetoA enhanced adiponectin production and glucose uptake during adipogenesis.« less

Comparison of Lactobacillus crispatus isolates from Lactobacillus-dominated vaginal microbiomes with isolates from microbiomes containing bacterial vaginosis-associated bacteria

PubMed Central

Abdelmaksoud, Abdallah A.; Koparde, Vishal N.; Sheth, Nihar U.; Serrano, Myrna G.; Glascock, Abigail L.; Fettweis, Jennifer M.; Strauss, Jerome F.; Buck, Gregory A.

2016-01-01

Vaginal lactobacilli can inhibit colonization by and growth of other bacteria, thereby preventing development of bacterial vaginosis (BV). Amongst the lactobacilli, Lactobacillus crispatus appears to be particularly effective at inhibiting growth of BV-associated bacteria. Nonetheless, some women who are colonized with this species can still develop clinical BV. Therefore, we sought to determine whether strains of L. crispatus that colonize women with lactobacilli-dominated vaginal microbiomes are distinct from strains that colonize women who develop BV. The genomes of L. crispatus isolates from four women with lactobacilli-dominated vaginal microbiomes ( < 1 % 16S rRNA reads above threshold from genera other than Lactobacillus) and four women with microbiomes containing BV-associated bacteria (>12 % 16S rRNA reads from bacterial taxa associated with BV) were sequenced and compared. Lactic acid production by the different strains was quantified. Phage induction in the strains was also analysed. There was considerable genetic diversity between strains, and several genes were exclusive to either the strains from Lactobacillus-dominated microbiomes or those containing BV-associated bacteria. Overall, strains from microbiomes dominated by lactobacilli did not differ from strains from microbiomes containing BV-associated bacteria with respect to lactic acid production. All of the strains contained multiple phage, but there was no clear distinction between the presence or absence of BV-associated bacteria with respect to phage-induced lysis. Genes found to be exclusive to the Lactobacillus-dominated versus BV-associated bacteria-containing microbiomes could play a role in the maintenance of vaginal health and the development of BV, respectively. PMID:26747455

Comparison of Lactobacillus crispatus isolates from Lactobacillus-dominated vaginal microbiomes with isolates from microbiomes containing bacterial vaginosis-associated bacteria.

PubMed

Abdelmaksoud, Abdallah A; Koparde, Vishal N; Sheth, Nihar U; Serrano, Myrna G; Glascock, Abigail L; Fettweis, Jennifer M; Strauss, Jerome F; Buck, Gregory A; Jefferson, Kimberly K

2016-03-01

Vaginal lactobacilli can inhibit colonization by and growth of other bacteria, thereby preventing development of bacterial vaginosis (BV). Amongst the lactobacilli, Lactobacillus crispatus appears to be particularly effective at inhibiting growth of BV-associated bacteria. Nonetheless, some women who are colonized with this species can still develop clinical BV. Therefore, we sought to determine whether strains of L. crispatus that colonize women with lactobacilli-dominated vaginal microbiomes are distinct from strains that colonize women who develop BV. The genomes of L. crispatus isolates from four women with lactobacilli-dominated vaginal microbiomes ( <1% 16S rRNA reads above threshold from genera other than Lactobacillus) and four women with microbiomes containing BV-associated bacteria (>12% 16S rRNA reads from bacterial taxa associated with BV) were sequenced and compared. Lactic acid production by the different strains was quantified. Phage induction in the strains was also analysed. There was considerable genetic diversity between strains, and several genes were exclusive to either the strains from Lactobacillus-dominated microbiomes or those containing BV-associated bacteria. Overall, strains from microbiomes dominated by lactobacilli did not differ from strains from microbiomes containing BV-associated bacteria with respect to lactic acid production. All of the strains contained multiple phage, but there was no clear distinction between the presence or absence of BV-associated bacteria with respect to phage-induced lysis. Genes found to be exclusive to the Lactobacillus-dominated versus BV-associated bacteria-containing microbiomes could play a role in the maintenance of vaginal health and the development of BV, respectively.

Characterization and evaluation of lactic acid bacteria candidates for intestinal epithelial permeability and Salmonella Typhimurium colonization in neonatal turkey poults.

PubMed

Yang, Y; Latorre, J D; Khatri, B; Kwon, Y M; Kong, B W; Teague, K D; Graham, L E; Wolfenden, A D; Mahaffey, B D; Baxter, M; Hernandez-Velasco, X; Merino-Guzman, R; Hargis, B M; Tellez, G

2018-02-01

The present study evaluated the microbiological properties of three probiotic candidate strains of lactic acid bacteria (LAB) (128; 131; CE11_2), their effect on intestinal epithelial permeability, and their ability to reduce intestinal colonization of Salmonella Typhimurium (ST) individually or as a batch culture in neonatal turkey poults. Isolates were characterized morphologically and identified using 16S rRNA sequence analyses. Each isolate was evaluated for tolerance and resistance to acidic pH, high osmotic NaCl concentrations, and bile salts in broth medium. In vitro assessment of antimicrobial activity against different enteropathogenic bacteria was determined using an overlay technique. In vitro intestinal permeability was evaluated using a stressed Caco-2 cell culture assay treated with/without the probiotic candidates. The in vivo effect of the selected LAB strains on ST cecal colonization was determined in two independent trials with neonatal turkey poults. The results obtained in this study demonstrate the tolerance of LAB candidates to pH 3, a NaCl concentration of 6.5%, and high bile salts (0.6%). All strains evaluated exhibited in vitro antibacterial activity against Salmonella Enteritidis, ST, and Campylobacter jejuni. Candidates 128 and 131 exhibited a coccus morphology and were identified as Enterococcus faecium, and bacterial strain CE11_2 exhibited clusters of cocci-shaped cells and was identified as Pediococcus parvulus. All three candidate probiotics significantly (P < 0.05) increased transepithelial electrical resistance (TEER) in Caco-2 cells following a 3-h incubation period with hydrogen peroxide compared to control and blank groups. The combination of all three candidates as a batch culture exhibited significant efficacy in controlling intestinal colonization of ST in neonatal turkey poults. Evaluation of the combination of these selected LAB strains according to performance and intestinal health parameters of chickens and turkeys are

Lactic Acid Bacteria – Friend or Foe? Lactic Acid Bacteria in the Production of Polysaccharides and Fuel Ethanol

USDA-ARS?s Scientific Manuscript database

Lactic acid bacteria (LAB) have been widely used in the production of fermented foods and as probiotics. Alternan is a glucan with a distinctive backbone structure of alternating a-(1,6) and a-(1,3) linkages produced by the LAB Leuconostoc mesenteroides. In recent years, we have developed improved...

Production of class II bacteriocins by lactic acid bacteria; an example of biological warfare and communication.

PubMed

Eijsink, Vincent G H; Axelsson, Lars; Diep, Dzung B; Håvarstein, Leiv S; Holo, Helge; Nes, Ingolf F

2002-08-01

Lactic acid bacteria (LAB) fight competing Gram-positive microorganisms by secreting anti-microbial peptides called bacteriocins. Peptide bacteriocins are usually divided into lantibiotics (class I) and non-lantibiotics (class II), the latter being the main topic of this review. During the past decade many of these bacteriocins have been isolated and characterized, and elements of the genetic mechanisms behind bacteriocin production have been unravelled. Bacteriocins often have a narrow inhibitory spectrum, and are normally most active towards closely related bacteria likely to occur in the same ecological niche. Lactic acid bacteria seem to compensate for these narrow inhibitory spectra by producing several bacteriocins belonging to different classes and having different inhibitory spectra. The latter may also help in counteracting the possible development of resistance mechanisms in target organisms. In many strains, bacteriocin production is controlled in a cell-density dependent manner, using a secreted peptide-pheromone for quorum-sensing. The sensing of its own growth, which is likely to be comparable to that of related species, enables the producing organism to switch on bacteriocin production at times when competition for nutrients is likely to become more severe. Although today a lot is known about LAB bacteriocins and the regulation of their production, several fundamental questions remain to be solved. These include questions regarding mechanisms of immunity and resistance, as well as the molecular basis of target-cell specificity.

Behavior of variable V3 region from 16S rDNA of lactic acid bacteria in denaturing gradient gel electrophoresis.

PubMed

Ercolini, D; Moschetti, G; Blaiotta, G; Coppola, S

2001-03-01

Separation of amplified V3 region from 16S rDNA by denaturing gradient gel electrophoresis (DGGE) was tested as a tool for differentiation of lactic acid bacteria commonly isolated from food. Variable V3 regions of 21 reference strains and 34 wild strains referred to species belonging to the genera Pediococcus, Enterococcus, Lactococcus, Lactobacillus, Leuconostoc, Weissella, and Streptococcus were analyzed. DGGE profiles obtained were species-specific for most of the cultures tested. Moreover, it was possible to group the remaining LAB reference strains according to the migration of their 16S V3 region in the denaturing gel. The results are discussed with reference to their potential in the analysis of LAB communities in food, besides shedding light on taxonomic aspects.

Draft genome sequences of bacteria isolated from the Deschampsia antarctica phyllosphere.

PubMed

Cid, Fernanda P; Maruyama, Fumito; Murase, Kazunori; Graether, Steffen P; Larama, Giovanni; Bravo, Leon A; Jorquera, Milko A

2018-05-01

Genome analyses are being used to characterize plant growth-promoting (PGP) bacteria living in different plant compartiments. In this context, we have recently isolated bacteria from the phyllosphere of an Antarctic plant (Deschampsia antarctica) showing ice recrystallization inhibition (IRI), an activity related to the presence of antifreeze proteins (AFPs). In this study, the draft genomes of six phyllospheric bacteria showing IRI activity were sequenced and annotated according to their functional gene categories. Genome sizes ranged from 5.6 to 6.3 Mbp, and based on sequence analysis of the 16S rRNA genes, five strains were identified as Pseudomonas and one as Janthinobacterium. Interestingly, most strains showed genes associated with PGP traits, such as nutrient uptake (ammonia assimilation, nitrogen fixing, phosphatases, and organic acid production), bioactive metabolites (indole acetic acid and 1-aminocyclopropane-1-carboxylate deaminase), and antimicrobial compounds (hydrogen cyanide and pyoverdine). In relation with IRI activity, a search of putative AFPs using current bioinformatic tools was also carried out. Despite that genes associated with reported AFPs were not found in these genomes, genes connected to ice-nucleation proteins (InaA) were found in all Pseudomonas strains, but not in the Janthinobacterium strain.

Rapid identification of dairy lactic acid bacteria by M13-generated, RAPD-PCR fingerprint databases.

PubMed

Rossetti, Lia; Giraffa, Giorgio

2005-11-01

About a thousand lactic acid bacteria (LAB) isolated from dairy products, especially cheeses, were identified and typed by species-specific PCR and RAPD-PCR, respectively. RAPD-PCR profiles, which were obtained by using the M13 sequence as a primer, allowed us to implement a large database of different fingerprints, which were analysed by BioNumerics software. Cluster analysis of the combined RAPD-PCR fingerprinting profiles enabled us to implement a library, which is a collection of library units, which in turn is a selection of representative database entries. A library unit, in this case, can be considered to be a definable taxon. The strains belonged to 11 main RAPD-PCR fingerprinting library units identified as Lactobacillus casei/paracasei, Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacillus helveticus, Lactobacillus delbrueckii, Lactobacillus fermentum, Lactobacillus brevis, Enterococcus faecium, Enterococcus faecalis, Streptococcus thermophilus and Lactococcus lactis. The possibility to routinely identify newly typed, bacterial isolates by consulting the library of the software was valued. The proposed method could be suggested to refine previous strain identifications, eliminate redundancy and dispose of a technologically useful LAB strain collection. The same approach could also be applied to identify LAB strains isolated from other food ecosystems.

Antagonistic lactic acid bacteria isolated from goat milk and identification of a novel nisin variant Lactococcus lactis

PubMed Central

2014-01-01

Background The raw goat milk microbiota is considered a good source of novel bacteriocinogenic lactic acid bacteria (LAB) strains that can be exploited as an alternative for use as biopreservatives in foods. The constant demand for such alternative tools justifies studies that investigate the antimicrobial potential of such strains. Results The obtained data identified a predominance of Lactococcus and Enterococcus strains in raw goat milk microbiota with antimicrobial activity against Listeria monocytogenes ATCC 7644. Enzymatic assays confirmed the bacteriocinogenic nature of the antimicrobial substances produced by the isolated strains, and PCR reactions detected a variety of bacteriocin-related genes in their genomes. Rep-PCR identified broad genetic variability among the Enterococcus isolates, and close relations between the Lactococcus strains. The sequencing of PCR products from nis-positive Lactococcus allowed the identification of a predicted nisin variant not previously described and possessing a wide inhibitory spectrum. Conclusions Raw goat milk was confirmed as a good source of novel bacteriocinogenic LAB strains, having identified Lactococcus isolates possessing variations in their genomes that suggest the production of a nisin variant not yet described and with potential for use as biopreservatives in food due to its broad spectrum of action. PMID:24521354

Phytase activity of lactic acid bacteria and their impact on the solubility of minerals from wholemeal wheat bread.

PubMed

Cizeikiene, Dalia; Juodeikiene, Grazina; Bartkiene, Elena; Damasius, Jonas; Paskevicius, Algimantas

2015-01-01

The objective of this study was to determinate phytase activity of bacteriocins producing lactic acid bacteria previously isolated from spontaneous rye sourdough. The results show that the highest extracellular phytase activity produces Pediococcus pentosaceus KTU05-8 and KTU05-9 strains with a volumetric phytase activity of 32 and 54 U/ml, respectively, under conditions similar to leavening of bread dough (pH 5.5 and 30 °C). In vitro studies in simulated gastrointestinal tract media pH provide that bioproducts prepared with P. pentosaceus strains used in wholemeal wheat bread preparation increase solubility of iron, zinc, manganese, calcium and phosphorus average 30%. Therefore, P. pentosaceus KTU05-9 and KTU05-8 strains could be recommended to use as a starter for sourdough preparation for increasing of mineral bioavailability from wholemeal wheat bread.

In vitro activity of ceftaroline against 623 diverse strains of anaerobic bacteria.

PubMed

Citron, D M; Tyrrell, K L; Merriam, C V; Goldstein, E J C

2010-04-01

The in vitro activities of ceftaroline, a novel, parenteral, broad-spectrum cephalosporin, and four comparator antimicrobials were determined against anaerobic bacteria. Against Gram-positive strains, the activity of ceftaroline was similar to that of amoxicillin-clavulanate and four to eight times greater than that of ceftriaxone. Against Gram-negative organisms, ceftaroline showed good activity against beta-lactamase-negative strains but not against the members of the Bacteroides fragilis group. Ceftaroline showed potent activity against a broad spectrum of anaerobes encountered in respiratory, skin, and soft tissue infections.

Ecology of Indigenous Lactic Acid Bacteria along Different Winemaking Processes of Tempranillo Red Wine from La Rioja (Spain)

PubMed Central

González-Arenzana, Lucía; Santamaría, Pilar; López, Rosa; Tenorio, Carmen; López-Alfaro, Isabel

2012-01-01

Ecology of the lactic acid bacteria (LAB) during alcoholic fermentation (AF) and spontaneous malolactic fermentation (MLF) of Tempranillo wines from four wineries of La Rioja has been studied analyzing the influence of the winemaking method, processing conditions, and geographical origin. Five different LAB species were isolated during AF, while, during MLF, only Oenococcus oeni was detected. Although the clonal diversity of O. oeni strains was moderate, mixed populations were observed, becoming at least one strain with distinct PFGE profile the main responsible for MLF. Neither the winemaking method nor the cellar situation was correlated with the LAB diversity. However, processing conditions influenced the total number of isolates and the percentage of each isolated species and strains. The winemaking method could cause that genotypes found in semicarbonic maceration did not appear in other wineries. Four genotypes of O. oeni were isolated in more than one of the rest wineries. These four together with other dominant strains might be included in a future selection process. PMID:22489202

Non-sterilized fermentation of high optically pure D-lactic acid by a genetically modified thermophilic Bacillus coagulans strain.

PubMed

Zhang, Caili; Zhou, Cheng; Assavasirijinda, Nilnate; Yu, Bo; Wang, Limin; Ma, Yanhe

2017-11-25

Optically pure D-lactic acid (≥ 99%) is an important precursor of polylactic acid. However, there are relatively few studies on D-lactic acid fermentation compared with the extensive investigation of L-lactic acid production. Most lactic acid producers are mesophilic organisms. Optically pure D-lactic acid produced at high temperature not only could reduce the costs of sterilization but also could inhibit the growth of other bacteria, such as L-lactic acid producers. Thermophilic Bacillus coagulans is an excellent producer of L-lactic acid with capable of growing at 50 °C. In our previous study, the roles of two L-lactic acid dehydrogenases have been demonstrated in B. coagulans DSM1. In this study, the function of another annotated possible L-lactate dehydrogenase gene (ldhL3) was verified to be leucine dehydrogenase with an activity of 0.16 units (μmol/min) per mg protein. Furthermore, the activity of native D-lactate dehydrogenase was too low to support efficient D-lactic acid production, even under the control of strong promoter. Finally, an engineered B. coagulans D-DSM1 strain with the capacity for efficient production of D-lactic acid was constructed by deletion of two L-lactate dehydrogenases genes (ldhL1 and ldhL2) and insertion of the D-lactate dehydrogenase gene (LdldhD) from Lactobacillus delbrueckii subsp. bulgaricus DSM 20081 at the position of ldhL1. This genetically engineered strain produced only D-lactic acid under non-sterilized condition, and finally 145 g/L of D-lactic acid was produced with an optical purity of 99.9% and a high yield of 0.98 g/g. This is the highest optically pure D-lactic acid titer produced by a thermophilic strain.

Genetic Approach for the Fast Discovery of Phenazine Producing Bacteria

PubMed Central

Schneemann, Imke; Wiese, Jutta; Kunz, Anna Lena; Imhoff, Johannes F.

2011-01-01

A fast and efficient approach was established to identify bacteria possessing the potential to biosynthesize phenazines, which are of special interest regarding their antimicrobial activities. Sequences of phzE genes, which are part of the phenazine biosynthetic pathway, were used to design one universal primer system and to analyze the ability of bacteria to produce phenazine. Diverse bacteria from different marine habitats and belonging to six major phylogenetic lines were investigated. Bacteria exhibiting phzE gene fragments affiliated to Firmicutes, Alpha- and Gammaproteobacteria, and Actinobacteria. Thus, these are the first primers for amplifying gene fragments from Firmicutes and Alphaproteobacteria. The genetic potential for phenazine production was shown for four type strains belonging to the genera Streptomyces and Pseudomonas as well as for 13 environmental isolates from marine habitats. For the first time, the genetic ability of phenazine biosynthesis was verified by analyzing the metabolite pattern of all PCR-positive strains via HPLC-UV/MS. Phenazine production was demonstrated for the type strains known to produce endophenazines, 2-hydroxy-phenazine, phenazine-1-carboxylic acid, phenazine-1,6-dicarboxylic acid, and chlororaphin as well as for members of marine Actinobacteria. Interestingly, a number of unidentified phenazines possibly represent new phenazine structures. PMID:21673888

Identification of lactic acid bacteria isolated from wine using real-time PCR.

PubMed

Kántor, Attila; Kluz, Maciej; Puchalski, Czeslaw; Terentjeva, Margarita; Kačániová, Miroslava

2016-01-01

Different lactic acid bacteria strains have been shown to cause wine spoilage, including the generation of substances undesirable for the health of wine consumers. The aim of this study was to investigate the occurrence of selected species of heterofermentative lactobacilli, specifically Lactobacillus brevis, Lactobacillus hilgardii, and Lactobacillus plantarum in six different Slovak red wines following the fermentation process. In order to identify the dominant Lactobacillus strain using quantitative (real time) polymerized chain reaction (qPCR) method, pure lyophilized bacterial cultures from the Czech Collection of Microorganisms were used. Six different red wine samples following malolactic fermentation were obtained from selected wineries. After collection, the samples were subjected to a classic plate dilution method for enumeration of lactobacilli cells. Real-time PCR was performed after DNA extraction from pure bacterial strains and wine samples. We used SYBR® Green master mix reagents for measuring the fluorescence in qPCR. The number of lactobacilli ranged from 3.60 to 5.02 log CFU mL(-1). Specific lactobacilli strains were confirmed by qPCR in all wine samples. The number of lactobacilli ranged from 10(3) to 10(6) CFU mL(-1). A melting curve with different melting temperatures (T(m)) of DNA amplicons was obtained after PCR for the comparison of T(m) of control and experimental portions, revealing that the most common species in wine samples was Lactobacillus plantarum with a T(m) of 84.64°C.

Phosphatidic Acid Synthesis in Bacteria

PubMed Central

Yao, Jiangwei; Rock, Charles O.

2012-01-01

Membrane phospholipid synthesis is a vital facet of bacterial physiology. Although the spectrum of phospholipid headgroup structures produced by bacteria is large, the key precursor to all of these molecules is phosphatidic acid (PtdOH). Glycerol-3-phosphate derived from the glycolysis via glycerol-phosphate synthase is the universal source for the glycerol backbone of PtdOH. There are two distinct families of enzymes responsible for the acylation of the 1-position of glycerol-3-phosphate. The PlsB acyltransferase was discovered in Escherichia coli, and homologs are present in many eukaryotes. This protein family primarily uses acyl-acyl carrier protein (ACP) endproducts of fatty acid synthesis as acyl donors, but may also use acyl-CoA derived from exogenous fatty acids. The second protein family, PlsY, is more widely distributed in bacteria and utilizes the unique acyl donor, acyl-phosphate, which is produced from acyl-ACP by the enzyme PlsX. The acylation of the 2-position is carried out by members of the PlsC protein family. All PlsCs use acyl-ACP as the acyl donor, although the PlsCs of the γ-proteobacteria also may use acyl-CoA. Phospholipid headgroups are precursors in the biosynthesis of other membrane-associated molecules and the diacylglycerol product of these reactions is converted to PtdOH by one of two distinct families of lipid kinases. The central importance of the de novo and recycling pathways to PtdOH in cell physiology suggest these enzymes are suitable targets for the development of antibacterial therapeutics in Gram-positive pathogens. This article is part of a Special Issue entitled Phospholipids and Phospholipid Metabolism. PMID:22981714

The effect of lactic acid bacteria isolates on the urinary tract pathogens to infants in vitro.

PubMed

Lim, In Seok; Lee, Ho Seok; Kim, Won Yong

2009-01-01

Urinary tract infections are common clinical problems in children, even though lots of treatment strategies have been tried. Many studies of the application of probiotics for urinary tract infection in female adults exist, but there is a lack of studies in children. The aims of this study were to screen probiotic strains for inhibiting the uropathogens in vitro, to find candidates for in vivo study. Nine strains of E. coli were isolated from children with urinary tract infection and six uropathogens were obtained from Korean Collection for Type Cultures and American Type Culture Collection. Also 135 lactic acid bacteria (LAB) strains were isolated from healthy children, and were identified through physiologic, biochemical methods, 16S rDNA PCR, and data analysis. And with agar disk diffusion assay technique the antimicrobial activities of these LAB strains against those uropathogens were examined. Three strains of separated LAB strains demonstrated major antimicrobial activity against all the uropathogens. In the agar disk diffusion assay technique, antimicrobial activities increased most in the 4th day culture broth with separated Lactobacillus. In summary, some LAB can be used as candidates to develop the probiotic microorganisms that inhibit uropathogens in children, and are expected to be applied to treatment and prevention of pediatric urinary tract infection.

Genetics of Lactic Acid Bacteria

NASA Astrophysics Data System (ADS)

Zagorec, Monique; Anba-Mondoloni, Jamila; Coq, Anne-Marie Crutz-Le; Champomier-Vergès, Marie-Christine

Many meat (or fish) products, obtained by the fermentation of meat originating from various animals by the flora that naturally contaminates it, are part of the human diet since millenaries. Historically, the use of bacteria as starters for the fermentation of meat, to produce dry sausages, was thus performed empirically through the endogenous micro-biota, then, by a volunteer addition of starters, often performed by back-slopping, without knowing precisely the microbial species involved. It is only since about 50 years that well defined bacterial cultures have been used as starters for the fermentation of dry sausages. Nowadays, the indigenous micro-biota of fermented meat products is well identified, and the literature is rich of reports on the identification of lactic acid bacteria (LAB) present in many traditional fermented products from various geographical origin, obtained without the addition of commercial starters (See Talon, Leroy, & Lebert, 2007, and references therein).

The use of lactic acid-producing, malic acid-producing, or malic acid-degrading yeast strains for acidity adjustment in the wine industry.

PubMed

Su, Jing; Wang, Tao; Wang, Yun; Li, Ying-Ying; Li, Hua

2014-03-01

In an era of economic globalization, the competition among wine businesses is likely to get tougher. Biotechnological innovation permeates the entire world and intensifies the severity of the competition of the wine industry. Moreover, modern consumers preferred individualized, tailored, and healthy and top quality wine products. Consequently, these two facts induce large gaps between wine production and wine consumption. Market-orientated yeast strains are presently being selected or developed for enhancing the core competitiveness of wine enterprises. Reasonable biological acidity is critical to warrant a high-quality wine. Many wild-type acidity adjustment yeast strains have been selected all over the world. Moreover, mutation breeding, metabolic engineering, genetic engineering, and protoplast fusion methods are used to construct new acidity adjustment yeast strains to meet the demands of the market. In this paper, strategies and concepts for strain selection or improvement methods were discussed, and many examples based upon selected studies involving acidity adjustment yeast strains were reviewed. Furthermore, the development of acidity adjustment yeast strains with minimized resource inputs, improved fermentation, and enological capabilities for an environmentally friendly production of healthy, top quality wine is presented.

Enhanced mucosal delivery of antigen with cell wall mutants of lactic acid bacteria.

PubMed

Grangette, Corinne; Müller-Alouf, Heide; Hols, Pascal; Goudercourt, Denise; Delcour, Jean; Turneer, Mireille; Mercenier, Annick

2004-05-01

The potential of recombinant lactic acid bacteria (LAB) to deliver heterologous antigens to the immune system and to induce protective immunity has been best demonstrated by using the C subunit of tetanus toxin (TTFC) as a model antigen. Two types of LAB carriers have mainly been used, Lactobacillus plantarum and Lactococcus lactis, which differ substantially in their abilities to resist passage through the stomach and to persist in the mouse gastrointestinal tract. Here we analyzed the effect of a deficiency in alanine racemase, an enzyme that participates in cell wall synthesis, in each of these bacterial carriers. Recombinant wild-type and mutant strains of L. plantarum NCIMB8826 and L. lactis MG1363 producing TTFC intracellularly were constructed and used in mouse immunization experiments. Remarkably, we observed that the two cell wall mutant strains were far more immunogenic than their wild-type counterparts when the intragastric route was used. However, intestinal TTFC-specific immunoglobulin A was induced only after immunization with the recombinant L. plantarum mutant strain. Moreover, the alanine racemase mutant of either LAB strain allowed induction of a much stronger serum TTFC-specific immune response after immunization via the vagina, which is a quite different ecosystem than the gastrointestinal tract. The design and use of these mutants thus resulted in a major improvement in the mucosal delivery of antigens exhibiting vaccine properties.

Remediation of Acid Mine Drainage with Sulfate Reducing Bacteria

ERIC Educational Resources Information Center

Hauri, James F.; Schaider, Laurel A.

2009-01-01

Sulfate reducing bacteria have been shown to be effective at treating acid mine drainage through sulfide production and subsequent precipitation of metal sulfides. In this laboratory experiment for undergraduate environmental chemistry courses, students design and implement a set of bioreactors to remediate acid mine drainage and explain observed…

Phenotypic and Genotypic Characterization of Non-Starter Lactic Acid Bacteria in Mature Cheddar Cheese

PubMed Central

Fitzsimons, N. A.; Cogan, T. M.; Condon, S.; Beresford, T.

1999-01-01

Non-starter lactic acid bacteria were isolated from 14 premium-quality and 3 sensorially defective mature Irish Cheddar cheeses, obtained from six manufacturers. From countable plates of Lactobacillus-selective agar, 20 single isolated colonies were randomly picked per cheese. All 331 viable isolates were biochemically characterized as mesophilic (i.e., group II) Lactobacillus spp. Phenotypically, the isolates comprised 96.4% L. paracasei, 2.1% L. plantarum, 0.3% L. curvatus, 0.3% L. brevis, and 0.9% unidentified species. Randomly amplified polymorphic DNA (RAPD) analysis was used to rapidly identify the dominant strain groups in nine cheeses from three of the factories, and through clustering by the unweighted pair group method with arithmetic averages, an average of seven strains were found per cheese. In general, strains isolated from cheese produced at the same factory clustered together. The majority of isolates associated with premium-quality cheese grouped together and apart from clusters of strains from defective-quality cheese. No correlation was found between the isomer of lactate produced and RAPD profiles, although isolates which did not ferment ribose clustered together. The phenotypic and genotypic methods employed were validated with a selection of 31 type and reference strains of mesophilic Lactobacillus spp. commonly found in Cheddar cheese. RAPD analysis was found to be a useful and rapid method for identifying isolates to the species level. The low homology exhibited between RAPD banding profiles for cheese isolates and collection strains demonstrated the heterogeneity of the L. paracasei complex. PMID:10427029

Lactic Acid Bacteria from Kefir Increase Cytotoxicity of Natural Killer Cells to Tumor Cells.

PubMed

Yamane, Takuya; Sakamoto, Tatsuji; Nakagaki, Takenori; Nakano, Yoshihisa

2018-03-27

The Japanese fermented beverage, homemade kefir, contains six lactic acid bacteria: Lactococcus. lactis subsp. Lactis , Lactococcus . lactis subsp. Cremoris , Lactococcus. Lactis subsp. Lactis biovar diacetylactis , Lactobacillus plantarum , Leuconostoc meseuteroides subsp. Cremoris and Lactobacillus casei . In this study, we found that a mixture of the six lactic acid bacteria from kefir increased the cytotoxicity of human natural killer KHYG-1 cells to human chronic myelogenous leukemia K562 cells and colorectal tumor HCT116 cells. Furthermore, levels of mRNA expression and secretion of IFN-γ (interferon gamma) increased in KHYG-1 cells that had been treated with the six lactic acid bacteria mixture from kefir. The results suggest that the six lactic acid bacteria mixture from kefir has strong effects on natural immunity and tumor cell cytotoxicity.

Assessment of Antibiotic Susceptibility within Lactic Acid Bacteria and Coagulase-Negative Staphylococci Isolated from Hunan Smoked Pork, a Naturally Fermented Meat Product in China.

PubMed

Wang, Jing; Wei, Xinyuan; Fan, Mingtao

2018-06-01

The aim of this study was to evaluate the antibiotic susceptibility of lactic acid bacteria (LAB) and coagulase-negative staphylococci (CNS) strains isolated from naturally fermented smoked pork produced in Hunan, China. A total of 48 strains were isolated by selective medium and identified at the species level by 16S rRNA gene sequencing as follows: Staphylococcus carnosus (23), Lactobacillus plantarum (12), Lactobacillus brevis (10), Lactobacillus sakei (1), Weissella confusa (1), and Weissella cibaria (1). All strains were typed by RAPD-PCR, and their susceptibility to 15 antibiotics was determined and expressed as the minimum inhibitory concentration (MIC) using agar dilution method. High resistance to penicillin G, streptomycin, gentamycin, vancomycin, chloramphenicol, norfloxacin, ciprofloxacin, kanamycin, and neomycin was found among the isolates. All the strains were sensitive to ampicillin, while the susceptibility to tetracycline, oxytetracycline, erythromycin, lincomycin, and roxithromycin varied. The presence of relevant resistance genes was investigated by PCR and sequencing, with the following genes detected: str(A), str(B), tet(O), tet(M), ere(A), and catA. Eleven strains, including 3 S. carnosus, 6 L. plantarum, and 2 L. brevis, harbored more than 3 antibiotic resistance genes. Overall, multiple antibiotic resistance patterns were widely observed in LAB and S. carnosus strains isolated from Hunan smoked pork. Risk assessment should be carried out with regard to the safe use of LAB and CNS in food production. We evaluated the antibiotic resistance of lactic acid bacteria and coagulase-negative staphylococci strains isolated from Chinese naturally fermented smoked pork. Our results may provide important data on establishing breakpoint standards for LAB and CNS and evaluating the safety risk of these strains for commercial use. © 2018 Institute of Food Technologists®.

Interactions between Cooccurring Lactic Acid Bacteria in Honey Bee Hives.

PubMed

Rokop, Z P; Horton, M A; Newton, I L G

2015-10-01

In contrast to the honey bee gut, which is colonized by a few characteristic bacterial clades, the hive of the honey bee is home to a diverse array of microbes, including many lactic acid bacteria (LAB). In this study, we used culture, combined with sequencing, to sample the LAB communities found across hive environments. Specifically, we sought to use network analysis to identify microbial hubs sharing nearly identical operational taxonomic units, evidence which may indicate cooccurrence of bacteria between environments. In the process, we identified interactions between noncore bacterial members (Fructobacillus and Lactobacillaceae) and honey bee-specific "core" members. Both Fructobacillus and Lactobacillaceae colonize brood cells, bee bread, and nectar and may serve the role of pioneering species, establishing an environment conducive to the inoculation by honey bee core bacteria. Coculture assays showed that these noncore bacterial members promote the growth of honey bee-specific bacterial species. Specifically, Fructobacillus by-products in spent medium supported the growth of the Firm-5 honey bee-specific clade in vitro. Metabolic characterization of Fructobacillus using carbohydrate utilization assays revealed that this strain is capable of utilizing the simple sugars fructose and glucose, as well as the complex plant carbohydrate lignin. We tested Fructobacillus for antibiotic sensitivity and found that this bacterium, which may be important for establishment of the microbiome, is sensitive to the commonly used antibiotic tetracycline. Our results point to the possible significance of "noncore" and environmental microbial community members in the modulation of honey bee microbiome dynamics and suggest that tetracycline use by beekeepers should be limited. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Isolation and Characterization of Anaerobic Bacteria for Symbiotic Recycling of Uric Acid Nitrogen in the Gut of Various Termites

PubMed Central

Thong-On, Arunee; Suzuki, Katsuyuki; Noda, Satoko; Inoue, Jun-ichi; Kajiwara, Susumu; Ohkuma, Moriya

2012-01-01

Recycling of the nitrogenous waste uric acid (UA) of wood-feeding termites by their gut bacteria is one of the significant aspects of symbiosis for the conservation of nitrogen sources. Diverse anaerobic UA-degrading bacteria comprising 16 species were isolated from the gut of eight termite species, and were assigned to Clostridia, Enterobacteriaceae, and low G+C Gram-positive cocci. UA-degrading Clostridia had never been isolated from termite guts. UA-degrading ability was sporadically distributed among phylogenetically various culturable anaerobic bacteria from termite guts. A strain of Clostridium sp., which was commonly isolated from three termite species and represented a probable new species in cluster XIVa of clostridia, utilized UA as a nitrogen source but not as a sole carbon and energy source. This feature is in clear contrast to that of well-studied purinolytic clostridia or previously isolated UA degraders from termite guts, which also utilize UA as a sole carbon and energy source. Ammonia is the major nitrogenous product of UA degradation. Various purines stimulated the growth of this strain when added to an otherwise growth-limiting, nitrogen poor medium. The bacterial species involved the recycling of UA nitrogen in the gut microbial community of termites are more diverse in terms of both taxonomy and nutritional physiology than previously recognized. PMID:22791052

[FATTY ACID COMPOSITION ALTEROMONAS-LIKE BACTERIA ISOLATED FROM THE BLACK SEA WATER].

PubMed

Klochko, V V; Avdeeva, L V

2015-01-01

Alteromonas macleodii strains isolated from the Black sea water were similar in their fatty acids composition with the type strain of this species. Analysis of lipid composition of 10 A. macleodii strains isolated from the deep and surface water layers in different World ocean regions including the Black sea water has shown that the deep and surface isolates of this species formed two groups different in their fatty acids profiles. The Black sea isolates of Pseudoalteromonas haloplanktis, P. citrea, P. flavipulchra conformed to these species type strains in their fatty acids composition. On the basis of the fatty acids spectra similarity of three Pseudoalteromonas species strains with Plipolytica described in 2010 has been established. Presence of three isomers C16:1ψ7, C 16:1ψ9 and C16:1ψ6--components of hexadecenic acid in the Black sea isolates of Shewanella baltica has been shown.

Evaluation of the intestinal colonization by microencapsulated probiotic bacteria in comparison with the same uncoated strains.

PubMed

Del Piano, Mario; Carmagnola, Stefania; Andorno, Silvano; Pagliarulo, Michela; Tari, Roberto; Mogna, Luca; Strozzi, Gian Paolo; Sforza, Filomena; Capurso, Lucio

2010-09-01

Beneficial findings concerning probiotics are increasing day by day. However, one of the most important parameter which affects the probiotic activity of a microorganism is its survival during the gastroduodenal transit. Some microencapsulation techniques could be applied to bacterial cells to improve this parameter. A comparison between the intestinal colonization by microencapsulated bacteria and the same not microencapsulated strains has been conducted in a double blind, randomized, cross-over study. The study (April to July 2005) involved 44 healthy volunteers. In particular, participants were divided into 2 groups: group A (21 participants) received a mix of probiotic strains Lactobacillus plantarum LP01 (LMG P-21021) and Bifidobacterium breve BR03 (DSM 16604) in an uncoated form, group B (23 participants) was given the same strains microencapsulated with a gastroresistant material. The not microencapsulated strains were administered at 5 x 10(9) colony forming units/strain/d for 21 days, whereas the microencapsulated bacteria were given at 1 x 10(9) colony forming units/strain/d for 21 days. At the end of the first period of treatment with probiotics a 3 weeks washout phase has been included in the study protocol. At the end of the washout period the groups were crossed: in detail, group A had the microencapsulated and group B the uncoated bacteria. The administered amounts of each strain were the same as the first treatment. The quantitative evaluation of intestinal colonization by strains microencapsulated or not microencapsulated was made by fecal samples examination at the beginning of the clinical trial, after 10 and 21 days of each treatment period. In particular, fecal heterofermentative Lactobacilli and Bifidobacteria have been counted. A statistically significant increase in the fecal amounts of Lactobacilli and Bifidobacteria was recorded in both groups at the end of each treatment compared with d0 or d42 (P<0.0001 and P<0.0001 at d21, P<0.0001 and

Assessing the exoproteome of marine bacteria, lesson from a RTX-toxin abundantly secreted by Phaeobacter strain DSM 17395.

PubMed

Durighello, Emie; Christie-Oleza, Joseph Alexander; Armengaud, Jean

2014-01-01

Bacteria from the Roseobacter clade are abundant in surface marine ecosystems as over 10% of bacterial cells in the open ocean and 20% in coastal waters belong to this group. In order to document how these marine bacteria interact with their environment, we analyzed the exoproteome of Phaeobacter strain DSM 17395. We grew the strain in marine medium, collected the exoproteome and catalogued its content with high-throughput nanoLC-MS/MS shotgun proteomics. The major component represented 60% of the total protein content but was refractory to either classical proteomic identification or proteogenomics. We de novo sequenced this abundant protein with high-resolution tandem mass spectra which turned out being the 53 kDa RTX-toxin ZP_02147451. It comprised a peptidase M10 serralysin domain. We explained its recalcitrance to trypsin proteolysis and proteomic identification by its unusual low number of basic residues. We found this is a conserved trait in RTX-toxins from Roseobacter strains which probably explains their persistence in the harsh conditions around bacteria. Comprehensive analysis of exoproteomes from environmental bacteria should take into account this proteolytic recalcitrance.

[Application of anaerobic bacteria detection in oral and maxillofacial infection].

PubMed

Bao, Zhen-ying; Lin, Qin; Meng, Yan-hong; He, Chun; Su, Jia-zeng; Peng, Xin

2016-02-18

To investigate the distribution and drug resistance of anaerobic bacteria in the patients with oral and maxillofacial infection. Aerobic and anaerobic bacteria cultures from 61 specimens of pus from the patients with oral and maxillofacial infection in the Department of Oral and Maxillofacial Surgery, Peking University School of Stomatology were identified. The culture type was evaluated by API 20A kit and drug resistance test was performed by Etest method. The clinical data and antibacterial agents for the treatment of the 61 cases were collected, and the final outcomes were recorded. The bacteria cultures were isolated from all the specimens, with aerobic bacteria only in 6 cases (9.8%), anaerobic bacteria only in 7 cases (11.5%), and both aerobic and anaerobic bacteria in 48 cases (78.7%). There were 55 infected cases (90.2%) with anaerobic bacteria, and 81 anaerobic bacteria stains were isolated. The highest bacteria isolation rate of Gram positive anaerobic bacteria could be found in Peptostreptococcus, Bifidobacterium and Pemphigus propionibacterium. No cefoxitin, amoxicillin/carat acid resistant strain was detected in the above three Gram positive anaerobic bacteria. The highest bacteria isolation rate of Gram negative anaerobic bacteria could be detected in Porphyromonas and Prevotella. No metronidazole, cefoxitin, amoxicillin/carat acid resistant strain was found in the two Gram negative anaerobic bacteria. In the study, 48 patients with oral and maxillofacial infection were treated according to the results of drug resistance testing, and the clinical cure rate was 81.3%. Mixed aerobic and anaerobic bacteria cultures are very common in most oral and maxillofacial infection patients. Anaerobic bacteria culture and drug resistance testing play an important role in clinical treatment.

Individual and co-operative roles of lactic acid and hydrogen peroxide in the killing activity of enteric strain Lactobacillus johnsonii NCC933 and vaginal strain Lactobacillus gasseri KS120.1 against enteric, uropathogenic and vaginosis-associated pathogens.

PubMed

Atassi, Fabrice; Servin, Alain L

2010-03-01

The mechanism underlying the killing activity of Lactobacillus strains against bacterial pathogens appears to be multifactorial. Here, we investigate the respective contributions of hydrogen peroxide and lactic acid in killing bacterial pathogens associated with the human vagina, urinary tract or intestine by two hydrogen peroxide-producing strains. In co-culture, the human intestinal strain Lactobacillus johnsonii NCC933 and human vaginal strain Lactobacillus gasseri KS120.1 strains killed enteric Salmonella enterica serovar Typhimurium SL1344, vaginal Gardnerella vaginalis DSM 4944 and urinary tract Escherichia coli CFT073 pathogens. The cell-free culture supernatants (CFCSs) produced the same reduction in SL1344, DSM 4944 and CFT073 viability, whereas isolated bacteria had no effect. The killing activity of CFCSs was heat-stable. In the presence of Dulbecco's modified Eagle's minimum essential medium inhibiting the lactic acid-dependent killing activity, CFCSs were less effective at killing of the pathogens. Catalase-treated CFCSs displayed a strong decreased activity. Tested alone, hydrogen peroxide triggered a concentration-dependent killing activity against all three pathogens. Lactic acid alone developed a killing activity only at concentrations higher than that present in CFCSs. In the presence of lactic acid at a concentration present in Lactobacillus CFCSs, hydrogen peroxide displayed enhanced killing activity. Collectively, these results demonstrate that for hydrogen peroxide-producing Lactobacillus strains, the main metabolites of Lactobacillus, lactic acid and hydrogen peroxide, act co-operatively to kill enteric, vaginosis-associated and uropathogenic pathogens.

Magnesium enriched lactic acid bacteria as a carrier for probiotic ice cream production.

PubMed

Góral, Małgorzata; Kozłowicz, Katarzyna; Pankiewicz, Urszula; Góral, Dariusz

2018-01-15

The following strains of bacteria: Lactobacillus rhamnosus B 442, Lactobacillus rhamnosus 1937, and Lactococcus lactis JBB 500 were enriched with magnesium ions using Pulsed Electric Fields. The potentially probiotic strains were added to the mixture in the DVS process and applied for the production of ice cream which were then analyzed physicochemically and microbiologically. Results showed that addition of bacteria enriched with magnesium did not change chemical parameters of the ice cream and did not affect the freezing process, meltability, and hardness. No significant differences were noted in colour of the samples. The ice cream with addition of bacteria enriched with magnesium had higher adhesiveness. The results of viability determination showed that the total number of microorganisms in the ice cream was higher than in the starter cultures. Viability of the bacteria enriched with magnesium in the obtained ice cream was lower in comparison to the control samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

Assessment of the in vitro bioactive properties of lactic acid bacteria isolated from native ecological niches of Ecuador.

PubMed

Benavides, Ana B; Ulcuango, Mario; Yépez, Lucía; Tenea, Gabriela N

Lactic acid bacteria are known for their biotechnological potential. In various regions of Ecuador numerous indigenous biological resources are largely undocumented. In this study, we evaluated the potential probiotic characteristics and antagonistic in vitro properties of some lactic acid bacteria from native niches of the subtropical rain forests of Ecuador. These isolates were identified according to their morphological properties, standard API50CH fermentation profile and RAPD-DNA polymorphism pattern. The selected isolates were further evaluated for their probiotic potential. The isolates grew at 15°C and 45°C, survived at a pH ranging from 2.5 to 4.5 in the presence of 0.3% bile (>90%) and grew under sodium chloride conditions. All selected isolates were sensitive to ampicillin, amoxicillin and cefuroxime and some showed resistance to gentamicin, kanamycin and tetracycline. Moreover, the agar well diffusion assay showed that the supernatant of each strain at pH 3.0 and pH 4.0, but not at pH 7.0 exhibited increased antimicrobial activity (inhibition zone >15mm) against two foodborne pathogens, Escherichia coli and Salmonella spp. To our knowledge, this is the first report describing the antagonistic activity against two foodborne pathogens and the probiotic in vitro potential of lactic acid bacteria isolated from native biota of Ecuador. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Extractive Fermentation of Lactic Acid in Lactic Acid Bacteria Cultivation: A Review.

PubMed

Othman, Majdiah; Ariff, Arbakariya B; Rios-Solis, Leonardo; Halim, Murni

2017-01-01

Lactic acid bacteria are industrially important microorganisms recognized for their fermentative ability mostly in their probiotic benefits as well as lactic acid production for various applications. Nevertheless, lactic acid fermentation often suffers end-product inhibition which decreases the cell growth rate. The inhibition of lactic acid is due to the solubility of the undissociated lactic acid within the cytoplasmic membrane and insolubility of dissociated lactate, which causes acidification of cytoplasm and failure of proton motive forces. This phenomenon influences the transmembrane pH gradient and decreases the amount of energy available for cell growth. In general, the restriction imposed by lactic acid on its fermentation can be avoided by extractive fermentation techniques, which can also be exploited for product recovery.

Extractive Fermentation of Lactic Acid in Lactic Acid Bacteria Cultivation: A Review

PubMed Central

Othman, Majdiah; Ariff, Arbakariya B.; Rios-Solis, Leonardo; Halim, Murni

2017-01-01

Lactic acid bacteria are industrially important microorganisms recognized for their fermentative ability mostly in their probiotic benefits as well as lactic acid production for various applications. Nevertheless, lactic acid fermentation often suffers end-product inhibition which decreases the cell growth rate. The inhibition of lactic acid is due to the solubility of the undissociated lactic acid within the cytoplasmic membrane and insolubility of dissociated lactate, which causes acidification of cytoplasm and failure of proton motive forces. This phenomenon influences the transmembrane pH gradient and decreases the amount of energy available for cell growth. In general, the restriction imposed by lactic acid on its fermentation can be avoided by extractive fermentation techniques, which can also be exploited for product recovery. PMID:29209295

Mutant E. coli strain with increased succinic acid production

DOEpatents

Donnelly, Mark; Millard, Cynthia S.; Stols, Lucy

1998-01-01

A method for isolating succinic acid producing bacteria is provided comprising increasing the biomass of an organism which lacks the ability to catabolize pyruvate, and then subjecting the biomass to glucose-rich medium in an anaerobic environment to enable pyruvate-catabolizing mutants to grow. The invention also provides for a mutant that produces high amounts of succinic acid, which as been derived from a parent which lacked the genes for pyruvate formate lyase and lactate dehydrogenase, and which belongs to the E.coli Group of Bacteria.

Mutant E. coli strain with increased succinic acid production

DOEpatents

Donnelly, Mark; Millard, Cynthia S.; Stols, Lucy

2001-09-25

A method for isolating succinic acid producing bacteria is provided comprising increasing the biomass of an organism which lacks the ability to catabolize pyruvate, and then subjecting the biomass to glucose-rich medium in an anaerobic environment to enable pyruvate-catabolizing mutants to grow. The invention also provides for a mutant that produces high amounts of succinic acid, which has been derived from a parent which lacked the genes for pyruvate formate lyase and lactate dehydrogenase, and which belongs to the E.coli Group of Bacteria.

Mutant E. coli strain with increased succinic acid production

DOEpatents

Donnelly, Mark; Millard, Cynthia S.; Stols, Lucy

2002-01-01

A method for isolating succinic acid producing bacteria is provided comprising increasing the biomass of an organism which lacks the ability to catabolize pyruvate, and then subjecting the biomass to glucose-rich medium in an anaerobic environment to enable pyruvate-catabolizing mutants to grow. The invention also provides for a mutant that produces high amounts of succinic acid, which has been derived from a parent which lacked the genes for pyruvate formate lyase and lactate dehydrogenase, and which belongs to the E.coli Group of Bacteria.

[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.

Antibacterial characteristics of newly developed amphiphilic lipids and DNA-lipid complexes against bacteria.

PubMed

Inoue, Y; Fukushima, T; Hayakawa, T; Takeuchi, H; Kaminishi, H; Miyazaki, K; Okahata, Y

2003-05-01

The purpose of this study was to investigate the antibacterial activity of newly developed amphiphilic lipids and DNA/lipid complexes against two types of oral bacteria and two types of hospital infection bacteria. Nine amphiphilic lipids were quantitatively prepared from the reaction of n-alkyl alcohol, alpha-amino acids, and p-toluenesulfonic acid. Nine DNA-lipid complexes were prepared by the simple mixing of DNA and amphiphilic lipids. The DNA-lipid complexes were insoluble in water. The antibacterial activity of lipids and DNA-lipid complexes against Porphyromonas gingivalis, Streptococcus mutans, Staphylococcus aureus, and Pseudomonas aeruginosa were evaluated by the disk-diffusion method. Seven artificial lipids showed antibacterial behavior; in particular, the lipids prepared from n-decyl alcohol and glycine and from n-decyl alcohol and L-alanine showed antibacterial activity against the four bacterial strains used in this study. On the other hand, the lipids of glutamic acid derivatives did not show any antibacterial activity against the four bacteria strains except for the lipid with an n-octyl group. Five DNA-lipid complexes also had an antibacterial effect. The complex prepared from DNA and glycine decyl ester p-toluenesulfonic acid salt exhibited antibacterial activity against the four types of bacteria strains. In this study it was found that lipids and DNA-lipid complexes with a mono-decyl group or a mono-dodecyl group have more favorable antibacterial activity. Copyright 2003 Wiley Periodicals, Inc.

Lactic Acid Bacteria from Kefir Increase Cytotoxicity of Natural Killer Cells to Tumor Cells

PubMed Central

Yamane, Takuya; Sakamoto, Tatsuji; Nakagaki, Takenori; Nakano, Yoshihisa

2018-01-01

The Japanese fermented beverage, homemade kefir, contains six lactic acid bacteria: Lactococcus. lactis subsp. Lactis, Lactococcus. lactis subsp. Cremoris, Lactococcus. Lactis subsp. Lactis biovar diacetylactis, Lactobacillus plantarum, Leuconostoc meseuteroides subsp. Cremoris and Lactobacillus casei. In this study, we found that a mixture of the six lactic acid bacteria from kefir increased the cytotoxicity of human natural killer KHYG-1 cells to human chronic myelogenous leukemia K562 cells and colorectal tumor HCT116 cells. Furthermore, levels of mRNA expression and secretion of IFN-γ (interferon gamma) increased in KHYG-1 cells that had been treated with the six lactic acid bacteria mixture from kefir. The results suggest that the six lactic acid bacteria mixture from kefir has strong effects on natural immunity and tumor cell cytotoxicity. PMID:29584690

Growth inhibition of Cronobacter spp. strains in reconstituted powdered infant formula acidified with organic acids supported by natural stomach acidity.

PubMed

Zhu, S; Schnell, S; Fischer, M

2013-09-01

Cronobacter is associated with outbreaks of rare, but life-threatening cases of meningitis, necrotizing enterocolitis, and sepsis in newborns. This study was conducted to determine the effect of organic acids on growth of Cronobacter in laboratory medium and reconstituted powdered infant formula (PIF) as well as the bacteriostatic effect of slightly acidified infant formula when combined with neonatal gastric acidity. Inhibitory effect of seven organic acids on four acid sensitive Cronobacter strains was determined in laboratory medium with broth dilution method at pH 5.0, 5.5 and 6.0. Acetic, butyric and propionic acids were most inhibitive against Cronobacter in the laboratory medium. The killing effect of these three acids was partially buffered in reconstituted PIF. Under neonatal gastric acid condition of pH 5.0, the slightly acidified formula which did not exert inhibition effect solely reduced significantly the Cronobacter populations. A synergistic effect of formula moderately acidified with organic acid combined with the physiological infant gastric acid was visible in preventing the rapid growth of Cronobacter in neonatal stomach. The study contributed to a better understanding of the inhibitory effect of organic acids on Cronobacter growth in different matrixes and provided new ideas in terms of controlling bacteria colonization and translocation by acidified formula. Copyright © 2013 Elsevier Ltd. All rights reserved.

Preservation of acidified cucumbers with a natural preservative combination of fumaric acid and allyl isothiocyanate that target lactic acid bacteria and yeasts

USDA-ARS?s Scientific Manuscript database

Without the addition of preservative compounds cucumbers acidified with 150 mM acetic acid with pH adjusted to 3.5 typically undergo fermentation by lactic acid bacteria. Fumaric acid (20 mM) inhibited growth of Lactobacillus plantarum and the lactic acid bacteria present on fresh cucumbers, but sp...

Rapid discrimination of strain-dependent fermentation characteristics among Lactobacillus strains by NMR-based metabolomics of fermented vegetable juice

PubMed Central

Nakamura, Toshihide; Sekiyama, Yasuyo; Kikuchi, Jun

2017-01-01

In this study, we investigated the applicability of NMR-based metabolomics to discriminate strain-dependent fermentation characteristics of lactic acid bacteria (LAB), which are important microorganisms for fermented food production. To evaluate the discrimination capability, six type strains of Lactobacillus species and six additional L. brevis strains were used focusing on i) the difference between homo- and hetero-lactic fermentative species and ii) strain-dependent characteristics within L. brevis. Based on the differences in the metabolite profiles of fermented vegetable juices, non-targeted principal component analysis (PCA) clearly separated the samples into those inoculated with homo- and hetero-lactic fermentative species. The separation was primarily explained by the different levels of dominant metabolites (lactic acid, acetic acid, ethanol, and mannitol). Orthogonal partial least squares discrimination analysis, based on a regions-of-interest (ROIs) approach, revealed the contribution of low-abundance metabolites: acetoin, phenyllactic acid, p-hydroxyphenyllactic acid, glycerophosphocholine, and succinic acid for homolactic fermentation; and ornithine, tyramine, and γ-aminobutyric acid (GABA) for heterolactic fermentation. Furthermore, ROIs-based PCA of seven L. brevis strains separated their strain-dependent fermentation characteristics primarily based on their ability to utilize sucrose and citric acid, and convert glutamic acid and tyrosine into GABA and tyramine, respectively. In conclusion, NMR metabolomics successfully discriminated the fermentation characteristics of the tested strains and provided further information on metabolites responsible for these characteristics, which may impact the taste, aroma, and functional properties of fermented foods. PMID:28759594

Amino Acid and Vitamin Requirements of Several Bacteroides Strains

PubMed Central

Quinto, Grace

1966-01-01

Nutritional studies were performed on nine Bacteroides strains, by use of the methodology and media of anaerobic rumen microbiology. Ristella perfoetens CCI required l-arginine hydrochloride, l-tryptophan, l-leucine, l-histidine hydrochloride, l-cysteine hydrochloride, dl-valine, dl-tyrosine, and the vitamin calcium-d-pantothenate, since scant turbidity developed in media without these nutrients. R. perfoetens was stimulated by glycine, dl-lysine hydrochloride, dl-isoleucine, l-proline, l-glutamic acid, dl-alanine, dl-phenylalanine, dl-methionine, and the vitamins nicotinamide and p-aminobenzoic acid, since maximal turbidity developed more slowly in media without these nutrients than in complete medium. Medium A-23, which was devised for R. perfoetens, contained salts, 0.0002% nicotinamide and calcium d-pantothenate, 0.00001% p-aminobenzoic acid, 0.044% l-tryptophan, 0.09% l-glutamic acid, and 0.1% of the other 13 amino acids listed above. Zuberella clostridiformis and seven strains of R. pseudoinsolita did not require vitamins, and showed no absolute requirement for any one amino acid. Various strains produced maximal turbidity more slowly in media deficient in l-proline, glycine, l-glutamic acid, dl-serine, l-histidine hydrochloride, dl-alanine, or l-cysteine hydrochloride, than in complete medium. These eight strains grew optimally in medium A-23 plus 0.1% dl-serine but without vitamins. PMID:16349673

Proteolytic and antimicrobial activity of lactic acid bacteria grown in goat milk.

PubMed

Atanasova, Jivka; Moncheva, Penka; Ivanova, Iskra

2014-11-02

We examined 62 strains and 21 trade starter cultures from the collection of LB Bulgaricum PLC for proteolytic and antimicrobial activity of lactic acid bacteria (LAB) grown in goat milk. The aim of this study was to investigate the fermentation of caseins, α-lactalbumin and β-lactoglobulin by LAB, using the o -phthaldialdehyde (OPA) spectrophotometric assay and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The proteolysis targeted mainly caseins, especially β-casein. Whey proteins were proteolyzed, essentially β-lactoglobulin. The proteolytic activity of Lactococcus lactis l598, Streptococcus thermophilus t3D1, Dt1, Lactobacillus lactis 1043 and L. delbrueckii subsp. bulgaricus b38, b122 and b24 was notably high. The proteolysis process gave rise to medium-sized peptide populations. Most of the examined strains showed antimicrobial activity against some food pathogens, such as Escherichia coli , Staphylococcus aureus , Salmonella cholere enteridis , Listeria monocytogenes , Listeria innocua and Enterobacter aerogenes . The most active producers of antimicrobial-active peptides were strains of L. delbrueckii subsp. bulgaricus and S. thermophilus , which are of practical importance. The starter cultures containing the examined species showed high proteolytic and antimicrobial activity in skimmed goat milk. The greatest antimicrobial activity of the cultures was detected against E. aerogenes . The obtained results demonstrated the significant proteolytic potential of the examined strains in goat milk and their potential for application in the production of dairy products from goat's milk. The present results could be considered as the first data on the proteolytic capacity of strains and starter cultures in goat milk for the purposes of trade interest of LB Bulgaricum PLC.

Processed milk waste recycling via thermal pretreatment and lactic acid bacteria fermentation.

PubMed

Kasmi, Mariam; Hamdi, Moktar; Trabelsi, Ismail

2017-05-01

Processed milk waste (MW) presents a serious problem within the dairy industries due to its high polluting load. Its chemical oxygen demand (COD) can reach values as high as 80,000 mg O 2  L -1 . This study proposes to reduce the organic load of those wastes using thermal coagulation and recover residual valuable components via fermentation. Thermal process results showed that the COD removal rates exceeded 40% when samples were treated at temperature above 60 °C to reach 72% at 100 °C. Clarified supernatants resulting from thermal treatment of the samples at the temperatures of 60 (MW 60 ), 80 (MW 80 ), and 100 °C (MW 100 ) were fermented using lactic acid bacteria strains without pH control. Lactic strains recorded important final cell yields (5-7 g L -1 ). Growth mediums prepared using the thermally treated MW produced 73% of the bacterial biomass recorded with a conventional culture medium. At the end of fermentation, mediums were found exhausted from several valuable components. Industrial scale implementation of the proposed process for the recycling of industrial MWs is described and discussed.

Mutant E. coli strain with increased succinic acid production

DOEpatents

Donnelly, M.; Millard, C.S.; Stols, L.

1998-06-23

A method for isolating succinic acid producing bacteria is provided comprising increasing the biomass of an organism which lacks the ability to catabolize pyruvate, and then subjecting the biomass to glucose-rich medium in an anaerobic environment to enable pyruvate-catabolizing mutants to grow. The invention also provides for a mutant that produces high amounts of succinic acid, which as been derived from a parent which lacked the genes for pyruvate formate lyase and lactate dehydrogenase, and which belongs to the E.coli Group of Bacteria. 2 figs.

Phylogenetic group- and species-specific oligonucleotide probes for single-cell detection of lactic acid bacteria in oral biofilms

PubMed Central

2011-01-01

Background The purpose of this study was to design and evaluate fluorescent in situ hybridization (FISH) probes for the single-cell detection and enumeration of lactic acid bacteria, in particular organisms belonging to the major phylogenetic groups and species of oral lactobacilli and to Abiotrophia/Granulicatella. Results As lactobacilli are known for notorious resistance to probe penetration, probe-specific assay protocols were experimentally developed to provide maximum cell wall permeability, probe accessibility, hybridization stringency, and fluorescence intensity. The new assays were then applied in a pilot study to three biofilm samples harvested from variably demineralized bovine enamel discs that had been carried in situ for 10 days by different volunteers. Best probe penetration and fluorescent labeling of reference strains were obtained after combined lysozyme and achromopeptidase treatment followed by exposure to lipase. Hybridization stringency had to be established strictly for each probe. Thereafter all probes showed the expected specificity with reference strains and labeled the anticipated morphotypes in dental plaques. Applied to in situ grown biofilms the set of probes detected only Lactobacillus fermentum and bacteria of the Lactobacillus casei group. The most cariogenic biofilm contained two orders of magnitude higher L. fermentum cell numbers than the other biofilms. Abiotrophia/Granulicatella and streptococci from the mitis group were found in all samples at high levels, whereas Streptococcus mutans was detected in only one sample in very low numbers. Conclusions Application of these new group- and species-specific FISH probes to oral biofilm-forming lactic acid bacteria will allow a clearer understanding of the supragingival biome, its spatial architecture and of structure-function relationships implicated during plaque homeostasis and caries development. The probes should prove of value far beyond the field of oral microbiology, as many of

Fermentation performance of lactic acid bacteria in different lupin substrates-influence and degradation ability of antinutritives and secondary plant metabolites.

PubMed

Fritsch, C; Vogel, R F; Toelstede, S

2015-10-01

The main objectives were to determine the influence of secondary plant metabolites and antinutritives in lupin seeds on the fermentation performance of lactic acid bacteria and to study their ability to degrade these substances. The suitability of lupin raw materials as fermentation substrates was examined. To evaluate the fermentation performance, microbial growth, metabolite formation and substrate uptake in three different lupin substrates was monitored. On the one hand, a lupin protein isolate, which contained only trace amounts of phytochemicals was used in the study. On the other hand, the flour of Lupinus angustifolius cv. Boregine and the flour of the alkaloid rich lupin Lupinus angustifolius cv. Azuro were inoculated with Bifidobacterium animalis subsp. lactis, Pediococcus pentosaceus, Lactobacillus plantarum and Lactococcus lactis subsp. lactis. The micro-organisms showed no significant differences in the fermentation performance on the different lupin flours. Similarly, the growth of most strains on lupin protein isolate was comparable to that on the lupin flours. The fermentation with Bifidobacterium animalis subsp. lactis led to a significant decrease in flatulence causing oligosaccharides. During fermentation with Lactobacillus plantarum the phytic acid content was partially degraded. Neither the secondary plant metabolites nor the antinutritives of lupin flour inhibited the growth or metabolic activity of the tested micro-organisms. Therefore, lupin flour is suitable for lactic fermentation. Some strains showed the ability to degrade oligosaccharides or phytic acid. This work contributes to the fundamental knowledge of the metabolism of lactic acid bacteria during fermentation of lupin substrates. Fermentation of lupin raw materials could be used to improve the nutritional value of the substrates due to the reduction of antinutritives. © 2015 The Society for Applied Microbiology.

Diversity of Lactic Acid Bacteria Associated with Banana Fruits in Taiwan.

PubMed

Chen, Yi-Sheng; Liao, Yu-Jou; Lan, Yi-Shan; Wu, Hui-Chung; Yanagida, Fujitoshi

2017-04-01

Banana is a popular fruit worldwide. The lactic acid bacteria (LAB) microflora in banana fruits has not been studied in detail. A total of 164 LAB were isolated from banana fruits in Taiwan. These isolates were initially divided into nine groups (r1 to r9) using restriction fragment length polymorphism analysis and 16S ribosomal DNA sequencing. Isolates belonging to Lactobacillus plantarum group were further divided into three additional groups using multiplex PCR assay targeting the recA gene. The most common bacterial genera found in banana fruits were Lactobacillus and Weissella. The distribution of LAB indicated that, in most cases, neighboring regions shared common strains, but there were still some differences between regions. On the basis of phylogenetic analysis of 16S rRNA, rpoA, and pheS gene sequences, two strains included in the genera Lactobacillus were identified as potential novel species or subspecies. In addition, a total 36 isolates were found to have bacteriocin-producing abilities. These results suggest that various LAB are associated with banana fruits in Taiwan. This is the first report describing the distribution and varieties of LAB associated with banana fruits. In addition, one potential novel LAB species was also found in this study.

Lactic Acid Bacteria Isolated from Bovine Mammary Microbiota: Potential Allies against Bovine Mastitis.

PubMed

Bouchard, Damien S; Seridan, Bianca; Saraoui, Taous; Rault, Lucie; Germon, Pierre; Gonzalez-Moreno, Candelaria; Nader-Macias, Fatima M E; Baud, Damien; François, Patrice; Chuat, Victoria; Chain, Florian; Langella, Philippe; Nicoli, Jacques; Le Loir, Yves; Even, Sergine

2015-01-01

Bovine mastitis is a costly disease in dairy cattle worldwide. As of yet, the control of bovine mastitis is mostly based on prevention by thorough hygienic procedures during milking. Additional strategies include vaccination and utilization of antibiotics. Despite these measures, mastitis is not fully under control, thus prompting the need for alternative strategies. The goal of this study was to isolate autochthonous lactic acid bacteria (LAB) from bovine mammary microbiota that exhibit beneficial properties that could be used for mastitis prevention and/or treatment. Sampling of the teat canal led to the isolation of 165 isolates, among which a selection of ten non-redundant LAB strains belonging to the genera Lactobacillus and Lactococcus were further characterized with regard to several properties: surface properties (hydrophobicity, autoaggregation); inhibition potential of three main mastitis pathogens, Staphylococcus aureus, Escherichia coli and Streptococcus uberis; colonization capacities of bovine mammary epithelial cells (bMEC); and immunomodulation properties. Three strains, Lactobacillus brevis 1595 and 1597 and Lactobacillus plantarum 1610, showed high colonization capacities and a medium surface hydrophobicity. These strains are good candidates to compete with pathogens for mammary gland colonization. Moreover, nine strains exhibited anti-inflammatory properties, as illustrated by the lower IL-8 secretion by E. coli-stimulated bMEC in the presence of these LAB. Full genome sequencing of five candidate strains allowed to check for undesirable genetic elements such as antibiotic resistance genes and to identify potential bacterial determinants involved in the beneficial properties. This large screening of beneficial properties while checking for undesirable genetic markers allowed the selection of promising candidate LAB strains from bovine mammary microbiota for the prevention and/or treatment of bovine mastitis.

Technological properties of bacteriocin-producing lactic acid bacteria isolated from Pico cheese an artisanal cow's milk cheese.

PubMed

Ribeiro, S C; Coelho, M C; Todorov, S D; Franco, B D G M; Dapkevicius, M L E; Silva, C C G

2014-03-01

Evaluate technologically relevant properties from bacteriocin-producing strains to use as starter/adjunct cultures in cheese making. Eight isolates obtained from Pico cheese produced in Azores (Portugal) were found to produce bacteriocins against Listeria monocytogenes and three isolates against Clostridium perfringens. They were identified as Lactococcus lactis and Enterococcus faecalis and submitted to technological tests: growth at different conditions of temperature and salt, acid production, proteolysis, lipolysis, coexistence, enzymatic profile and autolytic capacity. Safety evaluation was performed by evaluating haemolytic, gelatinase and DNase activity, resistance to antibiotics and the presence of virulence genes. Some isolates presented good technological features such as high autolytic activity, acid and diacetyl production. Lactococcus lactis was negative for all virulence genes tested and inhibit the growth of all Lactic acid bacteria (LAB) isolates. Enterococci were positive for the presence of some virulence genes, but none of the isolates were classified as resistant to important antibiotics. The bacteriocin-producing Lc. lactis present good potential for application in food as adjunct culture in cheese production. The study also reveals good technological features for some Enterococcus isolates. Bacteriocin-producing strains presented important technological properties to be exploited as new adjunct culture for the dairy industry, influencing flavour development and improve safety. © 2013 The Society for Applied Microbiology.

Screening for glycosidase activities of lactic acid bacteria as a biotechnological tool in oenology.

PubMed

Pérez-Martín, Fátima; Seseña, Susana; Izquierdo, Pedro Miguel; Martín, Raúl; Palop, María Llanos

2012-04-01

The aim of this study was to evaluate the ability from a number of lactic acid bacteria isolated from different sources to produce glycosidase enzymes. Representative isolates (225) from clusters obtained after genotyping, using randomly amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) analysis, of 1,464 isolates, were screened for β-D-glucosidase activity. Thirty-five of them were selected for subsequent analysis. These strains were able to hydrolyze α-D-glucopyranoside, β-D-xylopyranoside and α-L-arabinofuranoside although β-D-glucosidase activity was the predominant activity for 22 of the selected strains. Only some of them did so with α-L-rhamnopyranoside. All of these were from wine samples and were identified as belonging to the Oenococcus oeni species using Amplification and Restriction Analysis of 16S-rRNA gene (16S-ARDRA). When the influence of pH, temperature and ethanol or sugars content on β-D-glucosidase activity was assayed, a strain-dependent response was observed. The β-D-glucosidase activity occurred in both whole and sonicated cells but not in the supernatants from cultures or obtained after cell sonication. Strains 10, 17, 21, and 23 retained the most β-D-glucosidase activity when they were assayed at the conditions of temperature, pH, ethanol and sugar content used in winemaking. These results suggest that these strains could be used as a source of glycosidase enzymes for use in winemaking.

In Vitro Activity of TD-1792, a Multivalent Glycopeptide-Cephalosporin Antibiotic, against 377 Strains of Anaerobic Bacteria and 34 Strains of Corynebacterium Species

PubMed Central

Citron, Diane M.; Warren, Yumi A.; Goldstein, Ellie J. C.

2012-01-01

TD-1792 is a multivalent glycopeptide-cephalosporin heterodimer antibiotic with potent activity against Gram-positive bacteria. We tested TD-1792 against 377 anaerobes and 34 strains of Corynebacterium species. Against nearly all Gram-positive strains, TD-1792 had an MIC90 of 0.25 μg/ml and was typically 3 to 7 dilutions more active than vancomycin and daptomycin. PMID:22290981

Kinetics and Strain Specificity of Rhizosphere and Endophytic Colonization by Enteric Bacteria on Seedlings of Medicago sativa and Medicago truncatula

PubMed Central

Dong, Yuemei; Iniguez, A. Leonardo; Ahmer, Brian M. M.; Triplett, Eric W.

2003-01-01

The presence of human-pathogenic, enteric bacteria on the surface and in the interior of raw produce is a significant health concern. Several aspects of the biology of the interaction between these bacteria and alfalfa (Medicago sativa) seedlings are addressed here. A collection of enteric bacteria associated with alfalfa sprout contaminations, along with Escherichia coli K-12, Salmonella enterica serotype Typhimurium strain ATCC 14028, and an endophyte of maize, Klebsiella pneumoniae 342, were labeled with green fluorescent protein, and their abilities to colonize the rhizosphere and the interior of the plant were compared. These strains differed widely in their endophytic colonization abilities, with K. pneumoniae 342 and E. coli K-12 being the best and worst colonizers, respectively. The abilities of the pathogens were between those of K. pneumoniae 342 and E. coli K-12. All Salmonella bacteria colonized the interiors of the seedlings in high numbers with an inoculum of 102 CFU, although infection characteristics were different for each strain. For most strains, a strong correlation between endophytic colonization and rhizosphere colonization was observed. These results show significant strain specificity for plant entry by these strains. Significant colonization of lateral root cracks was observed, suggesting that this may be the site of entry into the plant for these bacteria. At low inoculum levels, a symbiosis mutant of Medicago truncatula, dmi1, was colonized in higher numbers on the rhizosphere and in the interior by a Salmonella endophyte than was the wild-type host. Endophytic entry of M. truncatula appears to occur by a mechanism independent of the symbiotic infections by Sinorhizobium meliloti or mycorrhizal fungi. PMID:12620870

Identification of Key Factors Involved in the Biosorption of Patulin by Inactivated Lactic Acid Bacteria (LAB) Cells.

PubMed

Wang, Ling; Wang, Zhouli; Yuan, Yahong; Cai, Rui; Niu, Chen; Yue, Tianli

2015-01-01

The purpose of this study was to identify the key factors involved in patulin adsorption by heat-inactivated lactic acid bacteria (LAB) cells. For preventing bacterial contamination, a sterilization process was involved in the adsorption process. The effects of various physical, chemical, and enzymatic pre-treatments, simultaneous treatments, and post-treatments on the patulin adsorption performances of six LAB strains were evaluated. The pre-treated cells were characterized by scanning electron microscopy (SEM). Results showed that the removal of patulin by viable cells was mainly based on adsorption or degradation, depending on the specific strain. The adsorption abilities were widely increased by NaOH and esterification pre-treatments, and reduced by trypsin, lipase, iodate, and periodate pre-treatments. Additionally, the adsorption abilities were almost maintained at pH 2.2-4.0, and enhanced significantly at pH 4.0-6.0. The effects of sodium and magnesium ions on the adsorption abilities at pH 4 were slight and strain-specific. A lower proportion of patulin was released from the strain with higher adsorption ability. Analyses revealed that the physical structure of peptidoglycan was not a principal factor. Vicinal OH and carboxyl groups were not involved in patulin adsorption, while alkaline amino acids, thiol and ester compounds were important for patulin adsorption. Additionally, besides hydrophobic interaction, electrostatic interaction also participated in patulin adsorption, which was enhanced with the increase in pH (4.0-6.0).

Characteristics of lactic acid bacteria isolates and their effect on the fermentation quality of Napier grass silage at three high temperatures.

PubMed

Gulfam, Ali; Guo, Gang; Tajebe, Seare; Chen, Lei; Liu, Qinhua; Yuan, Xianjun; Bai, Yunfeng; Saho, Tao

2017-04-01

The poor fermentation quality of silage is an important issue for silage production during the high temperatures of summer. Pediococcus acidilactici GG13 (GG13) and Lactobacillus rhamnosus GG26 (GG26) isolated from Italian ryegrass (Lolium multiflorum Lam.) silage were characterised by morphological and physiological tests and 16S rRNA sequencing analysis, and their effects, along with those of a commercial lactic acid bacteria (LAB) inoculant (CB), on the fermentation quality of facultative halophyte Napier grass (Pennisetum purpureum Schumach) ensiled at 30 °C, 40 °C and 50 °C were studied, respectively. The strains GG13 and GG26 grew well at 50 °C and pH 3.5, and were tolerant to 6.5% NaCl. After ensiling for 50 days, the strains GG13 and GG26 and the CB decreased (P < 0.001) the pH and acetic acid and ammonia-N contents and increased (P < 0.001) the lactic acid contents at 30 °C, and decreased (P < 0.001) the ammonia-N contents at 40 °C in Napier grass. CB did not affect the fermentation quality at 50 °C, whereas both isolated strains improved the fermentation quality of Napier grass silage as indicated by the lower (P < 0.001) pH, butyric acid and ammonia-N contents and higher (P < 0.001) lactic acid contents. The strain GG13 is better than GG26 with regard to improvement in fermentation quality of Napier grass silage. The results of this study suggested that strain GG13 is a good LAB inoculant for producing well-fermented silages during the high temperatures of summer times. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Assessing the Exoproteome of Marine Bacteria, Lesson from a RTX-Toxin Abundantly Secreted by Phaeobacter Strain DSM 17395

PubMed Central

Durighello, Emie; Christie-Oleza, Joseph Alexander; Armengaud, Jean

2014-01-01

Bacteria from the Roseobacter clade are abundant in surface marine ecosystems as over 10% of bacterial cells in the open ocean and 20% in coastal waters belong to this group. In order to document how these marine bacteria interact with their environment, we analyzed the exoproteome of Phaeobacter strain DSM 17395. We grew the strain in marine medium, collected the exoproteome and catalogued its content with high-throughput nanoLC-MS/MS shotgun proteomics. The major component represented 60% of the total protein content but was refractory to either classical proteomic identification or proteogenomics. We de novo sequenced this abundant protein with high-resolution tandem mass spectra which turned out being the 53 kDa RTX-toxin ZP_02147451. It comprised a peptidase M10 serralysin domain. We explained its recalcitrance to trypsin proteolysis and proteomic identification by its unusual low number of basic residues. We found this is a conserved trait in RTX-toxins from Roseobacter strains which probably explains their persistence in the harsh conditions around bacteria. Comprehensive analysis of exoproteomes from environmental bacteria should take into account this proteolytic recalcitrance. PMID:24586966

A natural odor attraction between lactic acid bacteria and the nematode Caenorhabditis elegans.

PubMed

Choi, Jae Im; Yoon, Kyoung-Hye; Subbammal Kalichamy, Saraswathi; Yoon, Sung-Sik; Il Lee, Jin

2016-03-01

Animal predators can track prey using their keen sense of smell. The bacteriovorous nematode Caenorhabditis elegans employs sensitive olfactory sensory neurons that express vertebrate-like odor receptors to locate bacteria. C. elegans displays odor-related behaviors such as attraction, aversion and adaptation, but the ecological significance of these behaviors is not known. Using a combination of food microbiology and genetics, we elucidate a possible predator-prey relationship between C. elegans and lactic acid bacteria (LAB) in rotting citrus fruit. LAB produces the volatile odor diacetyl as an oxidized by-product of fermentation in the presence of citrate. We show that C. elegans is attracted to LAB when grown on citrate media or Citrus medica L, commonly known as yuzu, a citrus fruit native to East Asia, and this attraction is mediated by the diacetyl odor receptor, ODR-10. We isolated a wild LAB strain and a wild C. elegans-related nematode from rotten yuzu, and demonstrate that the wild nematode was attracted to the diacetyl produced by LAB. These results not only identify an ecological function for a C. elegans olfactory behavior, but contribute to the growing understanding of ecological relationships between the microbial and metazoan worlds.