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

Fatty Acid Biosynthesis from a New Isolate Meyerella sp. N4: Molecular Characterization, Nutrient Starvation, and Fatty Acid Profiling for Lipid Enhancement

Microalgae are considered as potential feedstock for biodiesel production. In this study, a new green microalga was isolated from a freshwater pond in India and identified as Meyerella sp. N4. Nutrient starvation strategy was employed in this strain to understand the enhancement of the lipid accumulation. The increase in accumulated lipid was further confirmed by Nile red staining, followed by confocal laser scanning microscopic observation. Nitrogen (NaNO₃) starvation increased the lipid accumulation up to 60.4 ± 3.7% of dry cell weight at 314 ± 13 mg of total lipid/L in 23 days, when compared to the other conditions tested. Quantification of total fatty acid content by gas chromatography–mass spectrometry showed the presence of two major fatty acids, C16 at 34 ± 4.8 wt %, and C18:1 at 26 ± 3.6 wt %. Biodiesel quality parameters, such as cetane number at 57.7 ± 0.3, iodine value at 77.7 ± 1.1 g of I₂ 100 g^–1 of oil, saponification value at 190.5 ± 1.8 mg of KOH g^–1 of oil, and the cold filter plugging point at −1.5 ± 1.0 °C, are in good agreement with the international standards, American standard ASTM D6751 and European standard EN 14214, of biodiesel, thus making Meyerella sp. N4 a potential candidate for biodiesel production

Enhanced Extracellular Polysaccharide Production and Self-Sustainable Electricity Generation for PAMFCs by <i>Scenedesmus</i> sp. SB1

In this study, a freshwater microalga, <i>Scenedesmus</i> sp. SB1, was isolated, purified, and identified by its internal transcribed spacer region (ITS1-5.8S-ITS2). Media optimization through the Plackett–Burman Design and response surface methodology (RSM) showed a maximum exopolysaccharide (EPS) production of 48 mg/L (1.8-fold higher than that for unoptimized media). Characterization using gas chromatography–mass spectrometry, Fourier transform infrared, X-ray diffraction, and thermogravimetric analysis reveals that the EPS is a sulfated pectin polysaccharide with a crystallinity index of 15.2% and prompt thermal stability. Furthermore, the photoelectrogenic activity of <i>Scenedesmus</i> sp. SB1 inoculated in BG-11 and RSM-optimized BG-11 (ROBG-11) media was tested by cyclic voltammogram studies, revealing the potential of the inoculated strain in ROBG-11 toward photosynthetic algal microbial fuel cells over normal BG-11. To the best of our knowledge, functional group characterization, physical and thermal property and media optimization for EPS production by RSM and electrogenic activity studies are reported for the first time in <i>Scenedesmus</i> sp. SB1

Fatty Acid Biosynthesis from a New Isolate Meyerella sp. N4: Molecular Characterization, Nutrient Starvation, and Fatty Acid Profiling for Lipid Enhancement

Microalgae are considered as potential feedstock for biodiesel production. In this study, a new green microalga was isolated from a freshwater pond in India and identified as Meyerella sp. N4. Nutrient starvation strategy was employed in this strain to understand the enhancement of the lipid accumulation. The increase in accumulated lipid was further confirmed by Nile red staining, followed by confocal laser scanning microscopic observation. Nitrogen (NaNO₃) starvation increased the lipid accumulation up to 60.4 ± 3.7% of dry cell weight at 314 ± 13 mg of total lipid/L in 23 days, when compared to the other conditions tested. Quantification of total fatty acid content by gas chromatography–mass spectrometry showed the presence of two major fatty acids, C16 at 34 ± 4.8 wt %, and C18:1 at 26 ± 3.6 wt %. Biodiesel quality parameters, such as cetane number at 57.7 ± 0.3, iodine value at 77.7 ± 1.1 g of I₂ 100 g^–1 of oil, saponification value at 190.5 ± 1.8 mg of KOH g^–1 of oil, and the cold filter plugging point at −1.5 ± 1.0 °C, are in good agreement with the international standards, American standard ASTM D6751 and European standard EN 14214, of biodiesel, thus making Meyerella sp. N4 a potential candidate for biodiesel production