Alternative pathways for hydrogen sink originated from the ruminal fermentation of carbohydrates: Which microorganisms are involved in lowering methane emission?

Agriculture is responsible for a great share of the anthropogenic sources of greenhouse gases that, by warming the earth, threaten its biodiversity. Among greenhouse gas emissions, enteric CH4 from livestock is an important target to slow down climate changes. The CH4 is originated from rumen fermentation and its concentration is affected by several factors, including genetics and nutrition. Ruminants have an extraordinary symbiosis with microorganisms (bacteria, fungi, and protozoa) that ferment otherwise indigestible carbohydrates, from which they obtain energy to grow and continue actively producing, among other products, volatile fatty acids, CO2 and H2. Detrimental ruminal accumulation of H2 is avoided by methanogenesis carried out by Archaea methanogens. Importantly, methanogenesis is not the only H2 sink pathway. In fact, other bacteria can reduce substrates using metabolic hydrogen formed during carbohydrate fermentation, namely propionate production and reductive acetogenesis, thus lowering the CH4 produced. Although the complexity of rumen poses challenges to mitigate CH4 production, the emergence of sequencing techniques that allow the study of microbial communities, gene expression, and metabolome are largely contributing to unravel pathways and key players in the rumen. Indeed, it is now recognized that in vivo emissions of CH4 are correlated to microbial communities, and particularly with the abundance of methanogens, several bacterial groups, and their genes. The goal of CH4 mitigation is to work in favor of the natural processes, without compromising rumen function, animal health, and productivity. Notwithstanding, the major challenge continues to be the feasibility and affordability of the proposed solutions.

Isolation and Identification of Pigment Producing Actinomycete Saccharomonospora azurea SJCJABS01

Given the rising demand for biological pigments, especially of microbial origin – the present study was conducted so as to report a potential source for the extraction of microbial pigment. The main objective was to isolate and identify a pigment–producing actinomycete because pigment production is prevelant in this group. A powdery, greenish–blue colony with a chalky azure aerial mass was isolated from one of the many rhizosphere soil samples. Upon preliminary investigation, viz. colony characterization and grams staining, the suspected colony was observed to have a filamentous margin with a slightly raised elevation and gram–positive filamentous hyphae.Biochemical analyses of the organism revealed positive results for carbohydrate fermentation and Triple Sugar Iron (TSI) test with no signs of gas production during the former but gas & H­2­S production during the latter. The identity of the isolate was established via 16S rDNA and phylogeny analysis, which strongly suggested it was Saccharomonospora azurea. Limited research pertaining to morphology, physiology, genomics and secondary metabolite production with no reports on the physicochemical properties of the pigment produced by S. azureaadequately suggests that it is relatively novel. Hence, further studies related to the same could be beneficial to the scientific community.

The Carbohydrate Metabolism of Lactiplantibacillus plantarum

Lactiplantibacillus plantarum has a strong carbohydrate utilization ability. This characteristic plays an important role in its gastrointestinal tract colonization and probiotic effects. L. plantarum LP-F1 presents a high carbohydrate utilization capacity. The genome analysis of 165 L. plantarum strains indicated the species has a plenty of carbohydrate metabolism genes, presenting a strain specificity. Furthermore, two-component systems (TCSs) analysis revealed that the species has more TCSs than other lactic acid bacteria, and the distribution of TCS also shows the strain specificity. In order to clarify the sugar metabolism mechanism under different carbohydrate fermentation conditions, the expressions of 27 carbohydrate metabolism genes, catabolite control protein A (CcpA) gene ccpA, and TCSs genes were analyzed by quantitative real-time PCR technology. The correlation analysis between the expressions of regulatory genes and sugar metabolism genes showed that some regulatory genes were correlated with most of the sugar metabolism genes, suggesting that some TCSs might be involved in the regulation of sugar metabolism.

Metabolic potentials of Liquorilactobacillus nagelii AGA58 isolated from Shalgam based on genomic and functional analysis

The aim of present study was to perform functional and genomic characterization of a novel Liquorilactobacillus nagelii AGA58 isolated from Shalgam to understand its metabolic potentials. AGA58 is gram-positive,catalase-negative and appears as short-rods under light-microscope. The AGA58 chromosome composed of a single linear chromosome of 2,294,535 bp that is predicted to carry 2151 coding sequences, including 45 tRNA genes, 4 rRNA operons. Genome has a GC content of 36.9% includes 45 pseudogenes, 32 transposases and one intact-prophage. AGA58 is micro-anaerobic owing to shorter doubling time and faster growth rate achieved compared microaerofilic condition. It carries flagellar biosynthesis protein-encoding genes predicting motile behavior. AGA58 is an obligatory homofermentative where hexose sugars such as galactose, glucose, fructose, sucrose, mannose, N-acetyl glucosamine, maltose, trehalose are fermented to lactate thru glycolysis and no acid production from pentose sugars achieved due to lack of key enzyme namely phosphoketolase in pentose phosphate pathway. Carbohydrate fermentation tests showed AGA58 cannot ferment pentoses which was also confirmed in silico. Putative pyruvate metabolism revealed formate, malate, oxaloacetate, acetate, acetaldehyde, acetoin and lactate forms from pyruvate. AGA58 predicted to carry bacteriocin genes for type A2 lantipeptide, Blp family class II bacteriocins showing antimicrobial potential of this bacterium which can be linked to antagonism tests that AGA58 can inhibit E. coli O157:H7, S. Typhimurium ATCC14028, and K. pneumonia ATCC13883. Moreoever, AGA58 is tolerant to acid and bile concentrations simulating the human gastrointestinal conditions. L. nagelii AGA58 depicting the probiotic potential of AGA58 as a first report in literature within same species.

Lactic Acid Bacteria as A Bio Preservative: Importance and Production

Biopreservation is the method of employing natural microflora and their antimicrobial compounds to extend the storage life and improve the safety of foods. Streptococcus lactis was the first pure strain of lactic acid bacteria which was isolated from milk by Liszt. He named it bacterium lactis. Lactic acid bacteria are gram-positive, acid-tolerant, have low Guanine-Cytosine content and are generally non-sporulating, non-respiring, either spherical cocci or rod-shaped bacilli bacteria that share most of them their metabolic and physiological characteristics. These bacteria are mostly present in decomposing plants and milk products. They have an increased tolerance to acidity. Most species are incapable of respiration and therefore media used for lactic acid bacteria include a carbohydrate source. At the end of carbohydrate fermentation, these bacteria give out lactic acid as a major end product. The review focuses on the process of lactic acid production by lactic acid bacteria and its expanding importance in a variety of disciplines. Keywords: Lactic acid bacteria, bio preservative, food, microflora

Co-cultivation is a powerful approach to produce a robust functionally designed synthetic consortium as a live biotherapeutic product (LBP)

The successes of fecal microbiota transplants (FMT) have provided the necessary proof-of-concept for microbiome therapeutics. Because of the many risks and uncertainties associated with feces-based therapies, defined microbial consortia that modify the microbiome in a targeted manner have emerged as a promising safer alternative to FMT. The development of such live biotherapeutic products has important challenges, including the selection of appropriate strains and the production of the consortia at scale. Here, we report on an ecology and biotechnology-based approach to microbial consortium design that overcomes these issues. We designed a nine-strain consortium that emulates the central metabolic pathways of carbohydrate fermentation in the healthy human gut microbiota. We show that continuous co-culturing the bacteria produce a stable consortium whose activity is distinct from an equivalent mix of individually cultured strains. Further, we showed that our function-based consortium is as effective as FMT in counteracting dysbiosis in a dextran sodium sulfate mouse model of acute colitis. We propose that combining a bottom-up functional design with continuous co-cultivation is a powerful strategy to produce robust, functionally designed synthetic consortia for therapeutic use.

“Masato de Yuca” and “Chicha de Siete Semillas” Two Traditional Vegetable Fermented Beverages from Peru as Source for the Isolation of Potential Probiotic Bacteria

In this work, two Peruvian beverages “Masato de Yuca,” typical of the Amazonian communities made from cassava (Manihot esculenta), and “Chicha de Siete Semillas,” made from different cereal, pseudo-cereal, and legume flours, were explored for the isolation of lactic acid bacteria after obtaining the permission of local authorities following Nagoya protocol. From an initial number of 33 isolates, 16 strains with different RAPD- and REP-PCR genetic profiles were obtained. In Chicha, all strains were Lactiplantibacillus plantarum (formerly Lactobacillus plantarum), whereas in Masato, in addition to this species, Limosilactobacillus fermentum (formerly Lactobacillus fermentum), Pediococcus acidilactici, and Weissella confusa were also identified. Correlation analysis carried out with their carbohydrate fermentation patterns and enzymatic profiles allowed a clustering of the lactobacilli separated from the other genera. Finally, the 16 strains were submitted to a static in vitro digestion (INFOGEST model) that simulated the gastrointestinal transit. Besides, their ability to adhere to the human epithelial intestinal cell line HT29 was also determined. Following both procedures, the best probiotic candidate was Lac. plantarum Ch13, a robust strain able to better face the challenging conditions of the gastrointestinal tract and showing higher adhesion ability to the intestinal epithelium in comparison with the commercial probiotic strain 299v. In order to characterize its benefit for human health, this Ch13 strain will be deeply studied in further works.

Ruminococcus bovis sp. nov., a novel species of amylolytic Ruminococcus isolated from the rumen of a dairy cow

This study describes JE7A12T (=ATCC TSD-225T=NCTC 14479T), an isolate from the ruminal content of a dairy cow. Phenotypic and genotypic traits of the isolate were explored. JE7A12T was found to be a strictly anaerobic, catalase-negative, oxidase-negative, coccoid bacterium that grows in chains. The API 50 CH carbon source assay detected fermentation of d-glucose, d-fructose, d-galactose, glycogen and starch. HPLC showed acetate to be the major fermentation product as a result of carbohydrate fermentation. Phylogenetic analysis of JE7A12T based on 16S rRNA nucleotide sequence and amino acid sequences from the whole genome indicated a divergent lineage from the closest neighbours in the genus Ruminococcus . The results of 16S rRNA sequence comparison, whole genome average nucleotide identity (ANI) and DNA G+C content data indicate that JE7A12T represents a novel species which we propose the name Ruminococcus bovis with JE7A12T as the type strain.