L-asparaginase and L-glutaminase activities in submerged rice soil amended with municipal solid waste compost and decomposed cow manure

Taxonomic diversity of bacteria from mangrove sediments of Goa: metagenomic and functional analysis

The present study compared the taxonomic diversity and evaluated the functional attributes of the bacterial species from Mandovi and Zuari mangrove sediments, Goa, using paired-end amplicon sequencing of 16S rDNA and culture-based analyses, respectively. 16S rDNA sequencing revealed Proteobacteria, Firmicutes, and Actinobacteria as the dominant phyla in both the sediments. However, the abundance of these phyla significantly differed between the samples. Bacteroidetes from Mandovi sediment, and Acidobacteria and Gemmatimonadetes from Zuari sediment were the other exclusive major phyla. Chloroflexi, Cyanobacteria, Nitrospirae, Planctomycetes, Verrucomicrobia, and WS3 were the minor phyla observed in both. However, a significant difference in the distribution of minor phyla and lower bacterial taxa under each phylum was noted between the sediments, indicating that the resident microbial flora completely differed between them. This was further validated by high values from distance matrix analyses between the samples. In addition, the pathogenic Vibrio sp. was recorded exclusively in Mandovi sediment, while higher abundance of ecologically important bacterial classes including Gammaproteobacteria, Alphaproteobacteria, Deltaproteobacteria, and Bacilli was observed in Zuari sediment. Taken together, the data indicated that Zuari sediment was taxonomically richer than Mandovi sediment, while a greater incidence of anthropogenic activities occurred in the latter. This observation was further validated by non-parametric richness estimators which were found to be higher for Zuari sediment. The cultured bacterial isolates, all identified as Firmicutes, were tested for activities related to biofertilization and production of enzymes to be used for bioremediation and chemotherapeutic applications. Higher number of bacterial isolates from Mandovi was found to produce indole-acetic-acid, tannase, xylanase, and glutaminase enzymes, and could solubilize phosphate. In contrast, higher proportion of bacterial isolates from Zuari sediment were capable of producing amylase, cellulase, gelatinase, laccase, lipase, protease, and asparaginase enzymes, emphasizing the fact that the Zuari mangrove sediment is a rich reservoir for economically and biotechnologically important bacterial species.

Agro Waste Utilization for Cost-Effective Production of l-Asparaginase by Pseudomonas plecoglossicida RS1 with Anticancer and Acrylamide Mitigation Potential

Agricultural wastes such as the peels of onion and garlic were used as a supplement along with l-asparagine for the very first time to produce increased yield of l-asparaginase by Pseudomonas plecoglossicida RS1. Statistical optimization strategies such as response surface methodology were used to generate a medium composition containing extracts of 0.9 (v/v) of garlic peel waste and 0.5% (v/v) onion peel waste along with 0.2% (w/w) l-asparagine, which yielded a twofold increase in the enzyme activity compared to the unsupplemented minimal (M-9) medium. The presence of l-asparagine content in the peel extract was confirmed by high-performance liquid chromatography. Further, l-asparaginase was purified to homogeneity, and identity was confirmed by matrix-assisted laser desorption ionization time-of-flight analysis. The application of the purified l-asparaginase as a therapeutic was studied in HeLa cells which showed a p53-mediated G₂ cell cycle arrest. Moreover, the purified l-asparaginase showed effective acrylamide mitigation in vitro, at 6 IU, and its effective degradation was also demonstrated by the effect on chemotactic index of Caenorhabditis elegans and the restoration of the cognitive abilities of C. elegans which was coexposed to acrylamide and l-asparaginase compared to that exposed to acrylamide alone. Thus, l-asparaginase, with multipotent applications, was produced by effective waste utilization for economical commercial production.