Pediococcus stilesii sp. nov., isolated from maize grains

Metagenomics and metagenome-assembled genomes mining of health benefits in jalebi batter, a naturally fermented cereal-based food of India

Jalebi is one of the oldest Indian traditional fermented wheat-based confectioneries. Since jalebi is prepared by natural fermentation, diverse microbial community is expected to play bio-functional activities. Due to limited studies, information on microbial community structure in jalebi is unknown. Hence, the present study is aimed to profile the microbial community in jalebi by shotgun metagenomics and also to predict putative probiotic and functional genes by metagenome-assembled genome (MAG). Bacteria were the most abundant domain (91.91%) under which Bacillota was the most abundant phylum (82%). The most abundant species was Lapidilactobacillus dextrinicus followed by several species of lactic acid bacteria, acetic acid bacteria including few yeasts. Lap. dextrinicus was also significantly abundant in jalebi when compared to similar fermented wheat-based sourdough. Additionally, Lap. bayanensis, Pediococcus stilesii, and yeast- Candida glabrata, Gluconobacter japonicus, Pichia kudriavzevii, Wickerhamomyces anomalus were only detected in jalebi, which are not detected in sourdough. Few viruses and archaea were detected with < 1 % abundance. In silico screening of genes from the abundant species was mined using both KEGG and EggNOG database for putative health beneficial attributes. Circular genomes of five high-quality MAGs, identified as Lapidilactobacillus dextrinicus, Enterococcus hirae, Pediococcus stilesii, Acetobacter indonesiensis and Acetobacter cibinongensis, were constructed separately and putative genes were mapped and annotated. The CRISPR/Cas gene clusters in the genomes of four MAGs except Acetobacter cibinongensis were detected. MAGs also showed several secondary metabolites. Since, the identified MAGs have different putative genes for bio-functional properties, this may pave the way to selectively culture the uncultivated putative microbes for jalebi production. We believe this is the first report on metagenomic and MAGs of jalebi.

β-Glucan Production by Levilactobacillus brevis and Pediococcus claussenii for In Situ Enriched Rye and Wheat Sourdough Breads

Sourdough fermentation is a common practice spread across the globe due to quality and shelf life improvement of baked goods. Above the widely studied exopolysaccharide (EPS) formation, which is exploited for structural improvements of foods including baked goods, β-glucan formation, by using lactic acid bacteria (LAB), offers additional values. Through renunciation of sucrose addition for bacterial β-d-glucan formation, which is required for the production of other homopolysaccharides, residual sweetness of baked goods can be avoided, and predicted prebiotic properties can be exploited. As promising starter cultures Levilactobacillus (L.) brevis TMW (Technische Mikrobiologie Weihenstephan) 1.2112 and Pediococcus (P.) claussenii TMW 2.340 produce O2-substituted (1,3)-β-d-glucan upon fermenting wheat and rye doughs. In this study, we have evaluated methods for bacterial β-glucan quantification, identified parameters influencing the β-glucan yield in fermented sourdoughs, and evaluated the sourdough breads by an untrained sensory panel. An immunological method for the specific detection of β-glucan proved to be suitable for its quantification, and changes in the fermentation temperature were related to higher β-glucan yields in sourdoughs. The sensory analysis resulted in an overall acceptance of the wheat and rye sourdough breads fermented by L.brevis and P.claussenii with a preference of the L. brevis fermented wheat sourdough bread and tart-flavored rye sourdough bread.

Endophytic microbes: biodiversity, plant growth-promoting mechanisms and potential applications for agricultural sustainability

Endophytic microbes are known to live asymptomatically inside their host throughout different stages of their life cycle and play crucial roles in the growth, development, fitness, and diversification of plants. The plant-endophyte association ranges from mutualism to pathogenicity. These microbes help the host to combat a diverse array of biotic and abiotic stressful conditions. Endophytic microbes play a major role in the growth promotion of their host by solubilizing of macronutrients such as phosphorous, potassium, and zinc; fixing of atmospheric nitrogen, synthesizing of phytohormones, siderophores, hydrogen cyanide, ammonia, and act as a biocontrol agent against wide array of phytopathogens. Endophytic microbes are beneficial to plants by directly promoting their growth or indirectly by inhibiting the growth of phytopathogens. Over a long period of co-evolution, endophytic microbes have attained the mechanism of synthesis of various hydrolytic enzymes such as pectinase, xylanases, cellulase, and proteinase which help in the penetration of endophytic microbes into tissues of plants. The effective usage of endophytic microbes in the form of bioinoculants reduce the usage of chemical fertilizers. Endophytic microbes belong to different phyla such as Actinobacteria, Acidobacteria, Bacteroidetes, Deinococcus-thermus, Firmicutes, Proteobacteria, and Verrucomicrobia. The most predominant and studied endophytic bacteria belonged to Proteobacteria followed by Firmicutes and then by Actinobacteria. The most dominant among reported genera in most of the leguminous and non-leguminous plants are Bacillus, Pseudomonas, Fusarium, Burkholderia, Rhizobium, and Klebsiella. In future, endophytic microbes have a wide range of potential for maintaining health of plant as well as environmental conditions for agricultural sustainability. The present review is focused on endophytic microbes, their diversity in leguminous as well as non-leguminous crops, biotechnological applications, and ability to promote the growth of plant for agro-environmental sustainability.

A Genomic View of Lactobacilli and Pediococci Demonstrates that Phylogeny Matches Ecology and Physiology

Lactobacilli are used widely in food, feed, and health applications. The taxonomy of the genus Lactobacillus, however, is confounded by the apparent lack of physiological markers for phylogenetic groups of lactobacilli and the unclear relationships between the diverse phylogenetic groups. This study used the core and pan-genomes of 174 type strains of Lactobacillus and Pediococcus to establish phylogenetic relationships and to identify metabolic properties differentiating phylogenetic groups. The core genome phylogenetic tree separated homofermentative lactobacilli and pediococci from heterofermentative lactobacilli. Aldolase and phosphofructokinase were generally present in homofermentative but not in heterofermentative lactobacilli; a two-domain alcohol dehydrogenase and mannitol dehydrogenase were present in most heterofermentative lactobacilli but absent in most homofermentative organisms. Other genes were predominantly present in homofermentative lactobacilli (pyruvate formate lyase) or heterofermentative lactobacilli (lactaldehyde dehydrogenase and glycerol dehydratase). Cluster analysis of the phylogenomic tree and the average nucleotide identity grouped the genus Lactobacillus sensu lato into 24 phylogenetic groups, including pediococci, with stable intra- and intergroup relationships. Individual groups may be differentiated by characteristic metabolic properties. The link between phylogeny and physiology that is proposed in this study facilitates future studies on the ecology, physiology, and industrial applications of lactobacilli.

Recommended minimal standards for description of new taxa of the genera Bifidobacterium, Lactobacillus and related genera

Minimal standards for the description of new cultivable strains that represent novel genera and species belonging to the genera Bifidobacterium , Lactobacillus and related genera are proposed in accordance with Recommendation 30b of the Bacteriological Code (1990 Revision): the description of novel species should be based on phenotypic, genotypic and ecological characteristics to ensure a rich polyphasic characterization. Concerning genotypic characterization, in addition to DNA G+C content (mol%) data, the description should be based on DNA–DNA hybridization (DDH), 16S rRNA gene sequence similarities and at least two housekeeping gene (e.g. hsp60 and recA) sequence similarities. DDH might not be needed if the 16S rRNA gene sequence similarity to the closest known species is lower than 97 %. This proposal has been endorsed by members of the Subcommittee on the Taxonomy of Bifidobacterium , Lactobacillus and related organisms of the International Committee on the Systematics of Prokaryotes.

Potential of marine lactic acid bacteria to ferment Sargassum sp. for enhanced anticoagulant and antioxidant properties

AIM

To evaluate the suitability of marine lactic acid bacteria (LAB) as starter cultures for Sargassum sp. fermentation to enhance its antioxidant and anticoagulation activity.

METHODS AND RESULTS

LAB isolated from marine source were characterized for their ability to utilize seaweed as a sole carbon source and applied to Sargassum fermentation. Fermentation period was optimized by monitoring the fermented sample at regular interval for a period of 18 days. Results revealed that a fermentation period of 12 days was effective with maximum culture viability and other desirable characteristics such as pH, total titratable acidity, total and reducing sugars. Under optimum fermentation period, the sample fermented with P1-2CB-w1 (Enterococcus faecium) exhibited maximum anticoagulation activity and antioxidant activity.

CONCLUSIONS

The study reveals a novel well-defined starter culture from marine origin intended for seaweed fermentation for recovery of bioactive molecules.

SIGNIFICANCE AND IMPACT OF THE STUDY

The study provides information for the enhancement of bioactive molecules in an eco-friendly manner and also paves a way towards the development of wide range of seaweed functional foods.

Pediococcus lolii DSM 19927T and JCM 15055T are strains of Pediococcus acidilactici

Strain NGRI 0510QT, isolated from ryegrass silage, was recently classified as a representative of a novel Pediococcus species, Pediococcus lolii Doi et al. 2009. It was deposited in the DSMZ and JCM culture collections as DSM 19927T and JCM 15055T, respectively. A polyphasic taxonomic study, including matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, pheS and 16S rRNA gene sequence analysis, fluorescent amplified fragment length polymorphism and DNA–DNA hybridization, was used to prove that both subcultures of the type, and only, strain of this species are strains of Pediococcus acidilactici .

Weissella fabaria sp. nov., from a Ghanaian cocoa fermentation

Two lactic acid bacteria, strains 257T and 252, were isolated from traditional heap fermentations of Ghanaian cocoa beans. 16S rRNA gene sequence analysis of these strains allocated them to the genus Weissella, showing 99.5 % 16S rRNA gene sequence similarity towards Weissella ghanensis LMG 24286T. Whole-cell protein electrophoresis, fluorescent amplified fragment length polymorphism fingerprinting of whole genomes and biochemical tests confirmed their unique taxonomic position. DNA–DNA hybridization experiments towards their nearest phylogenetic neighbour demonstrated that the two strains represent a novel species, for which we propose the name Weissella fabaria sp. nov., with strain 257T (=LMG 24289T =DSM 21416T) as the type strain. Additional sequence analysis using pheS gene sequences proved useful for identification of all Weissella–Leuconostoc–Oenococcus species and for the recognition of the novel species.

Pantoea gaviniae sp. nov. and Pantoea calida sp. nov., isolated from infant formula and an infant formula production environment

Five Gram-negative, facultatively anaerobic, non-spore-forming, coccoid rod-shaped bacterial isolates were obtained from infant formula and an infant formula production environment and were investigated by use of a polyphasic taxonomic study. Biochemical tests and partial rpoB gene sequence analysis of the five isolates revealed that they formed two distinct groups in the family Enterobacteriaceae, closely related to several species of the genera Pantoea and Erwinia, which indicated a phylogenetic position within the genus Pantoea or the genus Erwinia. Multilocus sequence analysis of concatenated partial atpD, gyrB, infB and rpoB gene sequences of two of the isolates suggested that they represented two novel species of the genus Pantoea, phylogenetically related most closely to Pantoea septica. The five isolates had general characteristics consistent with those of the genus Pantoea, and DNA-DNA hybridizations between two representatives and the type strains of their phylogenetically closest relatives based on comparative 16S rRNA gene sequence analysis showed that the isolates represented two novel genospecies. These two genospecies could be differentiated from each other based on fermentation of galacturonate, sorbitol and potassium 5-ketogluconate. They could be differentiated from phylogenetically related Pantoea species based on their ability to ferment lactose and to utilize β-gentiobiose and raffinose, their inability to ferment or utilize d-arabitol, and their inability to produce indole. On the basis of the results obtained, the five isolates are considered to represent two novel species of the genus Pantoea, for which the names Pantoea gaviniae sp. nov. (type strain A18/07(T) =LMG 25382(T) =DSM 22758(T)) and Pantoea calida sp. nov. (type strain 1400/07(T) =LMG 25383(T) =DSM 22759(T)) are proposed.

Weissella beninensis sp. nov., a motile lactic acid bacterium from submerged cassava fermentations, and emended description of the genus Weissella

Four Gram-positive, catalase-negative, short rod-shaped or coccoid, heterofermentative lactic acid bacterial strains (2L24P13(T), 1L48P15, 1L24P31 and 1L24P34) with unusual phenotypic and genotypic properties were isolated from submerged fermenting cassava on MRS agar. All strains were motile, grew at 15 degrees C, produced dl-lactic acid from glucose with gas formation and produced ammonia from arginine. Acid was produced from d-fructose, d-galactose, d-glucose, lactose, maltose, d-mannose, melibiose, d-raffinose, sucrose, N-acetylglucosamine and d-mannitol, but not from d-arabinose or xylose. 16S rRNA gene sequence analysis revealed that the strains belonged to the genus Weissella and were most closely related to Weissella ghanensis LMG 24286(T). Low DNA-DNA reassociation values were obtained between the isolates and W. ghanensis DSM 19935(T). Based on the genetic and phenotypic results, the strains are considered to represent a novel species, for which the name Weissella beninensis sp. nov. is proposed. The type strain is 2L24P13(T) (=DSM 22752(T)=LMG 25373(T)).

Pediococcus lolii sp. nov., isolated from ryegrass silage

A Gram-positive, coccus-shaped, lactic acid bacterium, strain NGRI 0510Q(T), was isolated from ryegrass silage produced in Okinawa Prefecture, Japan. The cell is non-spore-forming, non-motile, and occurs in pairs or tetrads. The strain is homofermentative and produces d- and l-lactic acid from glucose. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain NGRI 0510Q(T) belongs to the genus Pediococcus and clusters within the Pediococcus acidilactici and Pediococcus pentosaceus group, with 98.2 and 96.9 % sequence identity, respectively. DNA-DNA relatedness between strain NGRI 0510Q(T) and P. acidilactici JCM 8797(T) and P. pentosaceus JCM 5890(T) was 19.3 and 17.3 %, respectively. Based on its phenotypic characteristics, phylogenetic relationship and DNA-DNA relatedness, NGRI 0510Q(T) (=JCM 15055(T)=DSM 19927(T)) represents the type strain of a novel species, for which the name Pediococcus lolii sp. nov. is proposed.

Differentiation of species of the family Acetobacteraceae by AFLP DNA fingerprinting: Gluconacetobacter kombuchae is a later heterotypic synonym of Gluconacetobacter hansenii

Amplified fragment length polymorphism (AFLP) DNA fingerprinting was investigated as a tool for fast and accurate identification of acetic acid bacteria (AAB) to the species level. One hundred and thirty five reference strains and 15 additional strains, representing 50 recognized species of the family Acetobacteraceae, were subjected to AFLP analysis using the restriction enzyme combination ApaI/TaqI and the primer combination A03/T03. The reference strains had been previously subjected to either DNA-DNA hybridization or 16S-23S rRNA spacer region gene sequence analysis and were regarded as being accurately classified at the species level. The present study revealed that six of these strains should be reclassified, namely Gluconacetobacter europaeus LMG 1518 and Gluconacetobacter xylinus LMG 1510 as Gluconacetobacter xylinus and Gluconacetobacter europaeus, respectively; Gluconacetobacter kombuchae LMG 23726(T) as Gluconacetobacter hansenii; and Acetobacter orleanensis strains LMG 1545, LMG 1592 and LMG 1608 as Acetobacter cerevisiae. Cluster analysis of the AFLP DNA fingerprints of the reference strains revealed one cluster for each species, showing a linkage level below 50 % with other clusters, except for Acetobacter pasteurianus, Acetobacter indonesiensis and Acetobacter cerevisiae. These three species were separated into two, two, and three clusters, respectively. At present, confusion exists regarding the taxonomic status of Gluconacetobacter oboediens and Gluconacetobacter intermedius; the AFLP data from this study supported their classification as separate taxa. The 15 additional strains could all be identified at the species level. AFLP analysis further revealed that some species harboured genetically diverse strains, whereas other species consisted of strains showing similar banding patterns, indicating a more limited genetic diversity. It can be concluded that AFLP DNA fingerprinting is suitable for accurate identification and classification of a broad range of AAB, as well as for the determination of intraspecific genetic diversity.

Pediococcus argentinicus sp. nov. from Argentinean fermented wheat flour and identification of Pediococcus species by pheS, rpoA and atpA sequence analysis

A Gram-positive, small coccus-shaped lactic acid bacterium, strain LMG 23999(T), was isolated from Argentinean wheat flour. 16S rRNA gene sequence analysis revealed that the phylogenetic position of the novel strain was within the genus Pediococcus, with Pediococcus stilesii, Pediococcus pentosaceus and Pediococcus acidilactici as its closest relatives (97.7, 97.3 and 96.9 % gene sequence similarity, respectively). Fluorescent amplified fragment length polymorphism fingerprinting of whole genomes and whole-cell protein electrophoresis confirmed the unique taxonomic status of the novel strain. DNA-DNA hybridizations, DNA G+C content determination, comparative sequence analysis of the pheS, rpoA and atpA genes and physiological and biochemical characterization demonstrated that strain LMG 23999(T) (=CCUG 54535(T)=CRL 776(T)) represents a novel species for which the name Pediococcus argentinicus sp. nov. is proposed. Multi-locus sequence analysis based on pheS, rpoA and atpA genes was found to be a suitable method for the identification of species of the genus Pediococcus.

Weissella ghanensis sp. nov., isolated from a Ghanaian cocoa fermentation

During a study on lactic acid bacteria (and their species diversity) in spontaneous heap fermentations of Ghanaian cocoa beans, two strains, designated 215(T) and 194B, were isolated. A phylogenetic analysis based on 16S rRNA gene sequences demonstrated that these strains represented a distinct lineage close to the genus Weissella and showing only 92.1 % 16S rRNA gene sequence similarity with respect to their closest neighbour, Weissella soli LMG 20113(T). Whole-cell protein electrophoresis, fluorescent amplified fragment length polymorphism fingerprinting of whole genomes and physiological and biochemical tests confirmed the unique taxonomic position of the two novel isolates. On the basis of the results of the morphological and biochemical tests and 16S rRNA gene sequence analysis, strains 215(T) and 194B represent the most peripheral lineage of the genus Weissella, for which we propose the name Weissella ghanensis sp. nov. The type strain is 215(T) (=LMG 24286(T)=DSM 19935(T)).

Acetobacter fabarum sp. nov., an acetic acid bacterium from a Ghanaian cocoa bean heap fermentation

Six acetic acid bacterial isolates, obtained during a study of the microbial diversity of spontaneous fermentations of Ghanaian cocoa beans, were subjected to a polyphasic taxonomic study. (GTG)(5)-PCR fingerprinting grouped the isolates together, but they could not be identified using this method. Phylogenetic analysis based on 16S rRNA gene sequences allocated the isolates to the genus Acetobacter and revealed Acetobacter lovaniensis, Acetobacter ghanensis and Acetobacter syzygii to be nearest neighbours. DNA-DNA hybridizations demonstrated that the isolates belonged to a single novel genospecies that could be differentiated from its phylogenetically nearest neighbours by the following phenotypic characteristics: no production of 2-keto-D-gluconic acid from D-glucose; growth on methanol and D-xylose, but not on maltose, as sole carbon sources; no growth on yeast extract with 30% D-glucose; and weak growth at 37 degrees C. The DNA G+C contents of four selected strains were 56.8-58.0 mol%. The results obtained prove that the isolates should be classified as representatives of a novel Acetobacter species, for which the name Acetobacter fabarum sp. nov. is proposed. The type strain is strain 985(T) (=R-36330(T) =LMG 24244(T) =DSM 19596(T)).

Acetobacter ghanensis sp. nov., a novel acetic acid bacterium isolated from traditional heap fermentations of Ghanaian cocoa beans

Twenty-three acetic acid bacteria, isolated from traditional heap fermentations of Ghanaian cocoa beans, were subjected to a polyphasic taxonomic study. The isolates were catalase-positive, oxidase-negative, Gram-negative rods. They oxidized ethanol to acetic acid and were unable to produce 2-ketogluconic acid, 5-ketogluconic acid and 2,5-diketogluconic acid from glucose; therefore, they were tentatively identified as Acetobacter species. 16S rRNA gene sequencing and phylogenetic analysis confirmed their position in the genus Acetobacter, with Acetobacter syzygii and Acetobacter lovaniensis as their closest phylogenetic neighbours. (GTG)(5)-PCR fingerprinting grouped the strains in a cluster that did not contain any type strains of members of the genus Acetobacter. DNA-DNA hybridization with the type strains of all recognized Acetobacter species revealed DNA-DNA relatedness values below the species level. The DNA G+C contents of three selected strains were 56.9-57.3 mol%. The novel strains had phenotypic characteristics that enabled them to be differentiated from phylogenetically related Acetobacter species, i.e. they were motile, did not produce 2-ketogluconic acid or 5-ketogluconic acid from glucose, were catalase-positive and oxidase-negative, grew on yeast extract with 30 % glucose, grew on glycerol (although weakly) but not on maltose or methanol as carbon sources, and did not grow with ammonium as sole nitrogen source and ethanol as carbon source. Based on the genotypic and phenotypic data, the isolates represent a novel species of the genus Acetobacter for which the name Acetobacter ghanensis sp. nov. is proposed. The type strain is R-29337(T) (=430A(T)=LMG 23848(T)=DSM 18895(T)).

Lactobacillus ghanensis sp. nov., a motile lactic acid bacterium isolated from Ghanaian cocoa fermentations

Three Gram-positive, catalase-negative, motile, rod-shaped strains, designated L486, L489T and L499, were isolated from fermenting cocoa. These organisms produced dl-lactic acid from glucose without gas formation. Ammonia was not produced from arginine. Acid was produced from amygdalin, d-cellobiose, aesculin, d-fructose, d-glucose, d-galactose, d-mannitol, d-mannose, N-acetylglucosamine, l-rhamnose, sucrose, salicin and d-trehalose. The cell walls contained peptidoglycan of the d-meso-diaminopimelic acid type. A 16S rRNA gene sequence analysis revealed that the isolates belong phylogenetically to the genus Lactobacillus and are closely related to Lactobacillus nagelii, Lactobacillus vini and Lactobacillus satsumensis. Low DNA–DNA reassociation values were obtained between the isolates and the phylogenetically closest neighbours. On the basis of the genetic and phenotypic results, the isolates are considered to represent a novel species, for which the name Lactobacillus ghanensis is proposed. The type strain is L489T (=DSM 18630T=CCUG 53453T).

Pediococcus ethanolidurans sp. nov., isolated from the walls of a distilled-spirit-fermenting cellar

Two novel Pediococcus strains, Z-9T and Z-17, were isolated from a distilled-spirit-fermenting cellar in Hebei Province, China. The cells were Gram-positive, non-spore-forming, non-motile cocci and occurred in pairs or tetrads. The strains were facultatively anaerobic and produced only lactic acid [d(−) and l(+) isomers in the ratio 50 : 50] from glucose fermentation. Catalase activity was not present. Both strains were able to grow in 6.5 % ethanol and at pH 3.5, but not in 4 % NaCl. The mean genomic G+C content of the two strains was 39.5±0.5 mol% (39 mol% for the type strain, Z-9T). The levels of 16S rRNA gene sequence similarity between the two novel strains and related species of the genus Pediococcus ranged from 98.3 to 98.7 %. The levels of DNA–DNA relatedness between strain Z-9T and the phylogenetically closely related pediococci Pediococcus damnosus LMG 11484T, Pediococcus inopinatus LMG 11409T, Pediococcus parvulus LMG 11486T and Pediococcus cellicola LMG 22956T were 14.6, 33, 28.7 and 16.8 %, respectively. On the basis of phenotypic, genotypic and phylogenetic analyses, a novel species, Pediococcus ethanolidurans sp. nov., is proposed, with strain Z-9T (=AS 1.3889T=LMG 23354T) as the type strain.