Bacterial diversity and metabolite profiles of curd prepared by natural fermentation of raw milk and back sloping of boiled milk.

Preparation of curd vary worldwide due to which its taste, texture and impact on human health also differ. In Assam, curd prepared from raw milk (RMC) is preferred over curd prepared from boiled milk (BMC), a tradition believed to have originated from the Mongoloid customs. Microbial diversity of raw milk (RM), boiled milk (BM), RMC and BMC collected from three farms were investigated by culture dependent and independent techniques. Additionally, metabolite profiles of RMC and BMC were studied by gas chromatography and mass spectroscopy. A total of 59 bacterial isolates were identified from the four different dairy products. In RM, lactic acid bacteria such as Lactococcus, Enterococcus, Lactobacillus and Leuconostoc were obtained along with the environmental bacteria like Bacillus, Staphylococcus, Acetobacter, Chryseobacterium, Streptococcus, Acinetobacter, Kocuria, Klebsiella and Macrococcus. Additionally, Prevotella, Oscillospira, Phascolarctobacterium and Akkermansia were also detected in BM by culture independent technique. In RMC and BMC, Lactococcus, Leuconostoc and Lactobacillus were prevalent. RM and RMC shared Enterococcus, Lactococcus, Streptococcus and Acinetobacter as common bacterial genera. However, no bacterial genus was common in BM and BMC. The correlation analysis revealed that Lactobacillus was negatively correlated to other bacterial genera. Oligotyping analysis revealed that Lactobacillus brevis and L.fermentum were abundant in RMC and BMC, respectively. In metabolomic study, ascorbic acid, dodecanoic acid and hexadecanoic acid were found to be significantly higher in RMC. Presence of different types of probiotics in these curds samples opens a new avenue to understand their effects on human health.

Multi-Omics Analysis Demonstrates the Critical Role of Non-Ethanolic Components of Alcoholic Beverages in the Host Microbiome and Metabolome: A Human- and Animal-Based Study.

It is known that alcoholic beverages alter the human gut microbiome. This study focused on the potential impact of non-ethanolic ingredients in whisky on the gut bacteriome. A pilot study was carried out on 15 whisky drinkers, 5 rice beer drinkers, and 9 non-drinkers to determine the effect of alcoholic beverages on the host microbiome and metabolome. Additionally, a mouse model was used to assess the differential impact of three whisky brands (each with an equal ethanol concentration). The results indicate that the non-ethanolic components have an impact on the gut microbiome, as well as on the metabolites in blood and feces. The amount of Prevotella copri, a typical core Indian gut bacterium, decreased in both the human and mouse groups of whisky type 1, but an increase in abundance of Helicobacteriaceae (p = 0.01) was noticed in both groups. Additionally, the alcohol-treated cohorts had lower levels of short-chain fatty acids (SCFAs), specifically butyric acid, and higher amounts of lipids and stress marker IL1-ß than the untreated groups (p = 0.04-0.01). Furthermore, two compounds, ethanal/acetaldehyde (found in all the whisky samples) and arabitol (unique to whisky type 1), were tested in the mice. Similar to the human subjects, the whisky type 1 treated mouse cohort and the arabitol-treated group showed decreased levels of Prevotella copri (p = 0.01) in their gut. The results showed that non-ethanolic compounds have a significant impact on host gut bacterial diversity and metabolite composition, which has a further vital impact on host health. Our work further emphasizes the need to study the impact of non-ethanolic ingredients of alcoholic beverages on host health.

Ethnicity-Influenced Microbiota: A Future Healthcare Perspective.

Global research is focused on understanding the factors affecting human gut microbiota vis-à-vis health. Brooks et al. [PLoS Biol. (2018) 16, e2006842] has reported a group of microbial taxa that vary across ethnicity in the USA (AGP and HMP data sets). Ethnicity-specific microbial signatures will aid in developing therapeutics for targeted microbiota modulation.

Chemometric analysis reveals links in the formation of fragrant bio-molecules during agarwood (Aquilaria malaccensis) and fungal interactions.

Fragrant agarwood, arguably the costliest wood in the world, is formed by plant-fungal interactions in Aquilaria spp. However, very little is known about this fragrant outcome of interaction. Therefore, mimicking the ancient traditions of agarwood production in Assam (Northeast India), a chemometric assessment of the agarwood-fungus interaction was made by chemical profiling (GC-MS) coupled with statistical analysis (principal component, correlation network analysis) across three platforms, viz. callus, juvenile plants and resinous wood-chips with an associated Fusarium. In the study of callus-fungus interaction, increased accumulation of key aroma compounds such as pentatriacontane {fold change (log2FC) = 3.47)}, 17-pentatriacontene (log2FC = 2.95), tetradecane, 2-methyl- (log2FC = 1.10) over callus and activation of pathways related to defense and secondary metabolism indicated links to aroma production. Study on fungal interactions in juvenile plants and resinous wood-chips indicated formation of terpenoid precursors (e.g. farnesol, geranylgeraniol acetate) and agarwood sesquiterpenes (e.g. agarospirol, γ-eudesmol). Correlation network analysis revealed the possible regulation of sesquiterpene biosynthesis involving squalene. Also a direct role of fungus in aroma (e.g. dodecane, 4-methyl-, tetracosane) was highlighted. Appearance of fragrant molecules unknown to agarwood during interaction featured as a new possibility for future research.

Gut bacterial diversity of the tribes of India and comparison with the worldwide data.

The gut bacteria exert phenotypic traits to the host but the factors which determine the gut bacterial profile (GBP) is poorly understood. This study aimed to understand the effect of ethnicity and geography on GBP of Mongoloid and Proto-Australoid tribes of India. Fecal bacterial diversity was studied in fifteen tribal populations representing four geographic regions (Assam, Telangana, Manipur and Sikkim) by DGGE followed by NGS analysis on Illumina MiSeq platform. Geography and diet had significant effect on GBP of the Indian tribes which was dominated by Prevotella. The effects were more prominent with lower taxonomic levels, indicating probable functional redundancy of the core GBP. A comparison with the worldwide data revealed that GBP of the Indian population was similar to the Mongolian population (Mongolia). The bacterial genera Faecalibacterium, Eubacterium, Clostridium, Blautia, Ruminococcus and Roseburia were found to be core genera in the representative populations of the world.

Immobilization of trypsin on plasma prepared Ag/PPAni nanocomposite film for efficient digestion of protein.

This work demonstrates the efficacy of a support matrix prepared by plasma process for trypsin immobilization without any surface activator. Plasma polymerization cum sputtering process is used to prepare the nanocomposite support matrix. Plasma sputtered silver nanoparticles (AgNPs) are uniformly embedded into plasma polymerized aniline (PPAni) film. Various characterization tools are employed to study the surface morphology, microstructure and chemical composition of the support matrices. Trypsin is immobilized onto the support matrix via the formation of covalent bond between them. Plasma generated free radicals on composite films activate the support matrix and make it efficient for increasing the tertiary enzyme stability via multipoint covalent attachment. Trypsin immobilized onto Ag/PPAni matrix has more hydrolyzing capacity of bovine serum albumin (BSA) than free trypsin as well as trypsin immobilized onto PPAni films.