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Antimicrobial resistance (AR) is a global problem with serious implications for public health. AR genes are frequently detected on animal farms, but little is known about their origin and distribution patterns. We hypothesized that AR genes can transfer from animal feces to the environment through manure, and to this end, we characterized and compared the resistomes (collections of AR genes) of animal feces, manure, and soil samples collected from five dairy farms using a metagenomics approach. Resistomes constituted only up to 1% of the total gene content, but were variable by sector and also farm. Broadly, the identified AR genes were associated with 18 antibiotic resistances classes across all samples; however, the most abundant genes were classified under multidrug transporters (44.75%), followed by resistance to vancomycin (12.48%), tetracycline (10.52%), bacitracin (10.43%), beta-lactam resistance (7.12%), and MLS efflux pump (6.86%) antimicrobials. The AR gene profiles were variable between farms. Farm 09 was categorized as a high risk farm, as a greater proportion of AR genes were common to at least three sectors, suggesting possible horizontal transfer of AR genes. Taxonomic characterization of AR genes revealed that a majority of AR genes were associated with the phylum Proteobacteria. Nonetheless, there were several members of Bacteroidetes, particularly Bacteroides genus and several lineages from Firmicutes that carried similar AR genes in different sectors, suggesting a strong potential for horizontal transfer of AR genes between unrelated bacterial hosts in different sectors of the farms. Further studies are required to affirm the horizontal gene transfer mechanisms between microbiomes of different sectors in animal agroecosystems.

Corn cob is an abundant organic source with significant potential in sustainable energy development. For the effective conversion of the feedstocks to valued commodities, effective biocatalysts are highly desired. The present study aims at optimizing the critical parameters required for xylanase production by Penicillium purpurogenum isolated from rotten wood sample using the Taguchi orthogonal array layout of L25 (5 ∧ 6). The optimized conditions like temperature 40 • C, pH 3, size of inoculum 1.2 × 10 8 spores/ml, moisture 70%, peptone 0.8%, and 5 days of incubation resulted in 1,097 ± 6.76 U/gram dry substrate (gds) xylanase which was 65.72% more when compared to un-optimized production of xylanase. The xylanase thus produced, effectively carried out pretreated corn cob saccharification and the reaction was further improved with ultrasound assistance which has increased the saccharification yield to 12.02% along with significant reduction in reaction time. The saccharification efficiency of pretreated corn cob was found to be 80.29% more compared to the raw corn cob, reflecting its recalcitrance to digestion. Indeed, xylan being the second most abundant polymer in lignocellulosic biomass, considerable attention is being paid for its effective conversion to valued products.

The purpose of this study is to evaluate the probiotic characteristics of 15 yeast strains isolated from nectar of toddy palm. Initially, the collected samples were inoculated on yeast extract peptone dextrose agar plates and the colonies so obtained were culturally and morphologically characterized. Commercial probiotic yeast, Saccharomyces boulardii served as the control in these experiments. Of the 15 yeast strains, the isolates that were resistant to antibiotics and worked synergistically with other cultures were considered for further evaluation. Selected isolates were evaluated in vitro for tolerance to simulated gastrointestinal conditions such as temperature, pH, bile and gastric juice. Further the yeast isolates were evaluated for their pathogenicity and adherence to intestinal epithelial cells. The 2 yeast isolates with efficient probiotic properties were finally characterized by sequencing their 5.8 S rRNA and partial sequences of internal transcribed spacer 1 and 2. The sequences were BLAST searched in the National Center for Biotechnology Information, nucleic acid database for sequence similarity of organisms and phylogenetic evolutionary analysis was carried out. Based on maximum similarity of basic local alignment search tool results, organisms were characterized as Pichia kudriavzevii OBS1 (100%) and Saccharomyces cerevisiae OBS2 (96%) and sequences were finally deposited in the GenBank data library. Among these two isolates, S. cerevisiae OBS2 displayed slight/moderate antioxidant and anticancer property. Hence, strain OBS2 can be utilized and explored as a potential probiotic for therapeutic applications.

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