Waste frying oil hydrolysis and lipase production by cold-adapted Pseudomonas yamanorum LP2 under non-sterile culture conditions

Use of waste frying oil and coconut pulp for the production, isolation, and characterization of a new lipase from Moesziomyces aphidis

Lipases comprise the third most commercialized group of enzymes worldwide and those of microbial origin are sought for their multiple advantages. Agro-industrial waste can be an alternative culture medium for producing lipases, reducing production costs and the improper disposal of waste frying oil (WFO). This study aimed to produce yeast lipases through submerged fermentation (SF) using domestic edible oil waste as inducer and alternative culture medium. The optimal culture conditions, most effective inducer, and purification method for a new lipase from Moesziomyces aphidis BRT57 were identified. Yeast was cultured in medium containing green coconut pulp and WFO waste for 72 h. The maximum production of lipases in SF occurred in a culture medium containing WFO and yeast extract at 48 and 72 h of incubation, with enzyme activities of 8.88 and 11.39 U mL-1, respectively. The lipase was isolated through ultrafiltration followed by size exclusion chromatography, achieving a 50.46 % recovery rate. To the best of our knowledge, this is the first study to report the production and purification of lipases from M. aphidis, demonstrating the value of frying oil as inducer and alternative medium for SF, contributing to the production of fatty acids for biodiesel from food waste.

Multi-substrate sequential optimization, characterization and immobilization of lipase produced by Pseudomonas plecoglossicida S7

Lipases are important biocatalysts having the third largest global demand after amylases and proteases. In the present study, we have screened 56 potential lipolytic Pseudomonas strains for their lipolytic activity. Pseudomonas plecoglossicida S7 showed highest lipase production with specific activity of 70 U/mg. Statistical optimizations using Plackett Burman design and response surface methodology evaluated fourteen different media supplements including various oilcakes, carbon sources, nitrogen sources, and metal ions which led to a 2.23-fold (156.23 U/mg) increase in lipase activity. Further, inoculum size optimization increased the overall lipase activity by 2.81-folds. The lipase was active over a range of 30-50° C with a pH range (7-10). The enzyme was tolerant to various solvents like chloroform, methanol, 1-butanol, acetonitrile, and dichloromethane and retained 60% of its activity in the presence of sodium dodecyl sulfate (0.5% w/v). The enzyme was immobilized onto Ca-alginate beads which increased thermal (20-60 °C) and pH stability (5-10). The purified enzyme could successfully remove sesame oil stains and degraded upto 25.2% of diesel contaminated soil. These properties of the lipase will help in its applicability in detergent formulations, wastewater treatments, and biodegradation of oil in the environment.

Statistical Optimization for Cost-Effective Production of Yeast-Bacterium Cell-Bound Lipases Using Blended Oily Wastes and Their Potential Applications in Biodiesel Synthesis and Wastewater Bioremediation

Oily wastes have been widely used to produce lipases, but there is insufficient knowledge on their use to efficiently produce cell-bound lipases (CBLs). This research aimed to optimize yeast–bacterium CBLs production using blended oily wastes by statistical optimization and their potential applications in biodiesel production and wastewater bioremediation. The co-culture of Magnusiomyces spicifer AW2 and Staphylococcus hominis AUP19 produced CBLs as high as 4709 U/L with cell biomass of 23.4 g/L in a two-fold diluted palm oil mill effluent (POME) added by 2.08% (v/v) waste frying oil, 1.72.0% (w/v) ammonium sulfate, 0.1% (w/v) Gum Arabic as an emulsifier (initial pH at 7.0) within 24 h. The CBLs were successfully applied as whole-cell biocatalysts to produce biodiesel through esterification and transesterification with 76% and 87% yields, respectively. Direct application of CBLs for bioremediation of heat-treated various POME concentrations achieved 73.3% oil and grease removal and 73.6% COD removal within 3 days. This study has shown that the blended oily wastes medium was suitable for low-cost production of yeast–bacterium CBLs and their potential applications in solvent-free biodiesel production and wastewater bioremediation. These strategies may greatly contribute to economical green biofuel production and waste biotreatment.

Extracellular production of azurin from Pseudomonas aeruginosa in the presence of Triton X-100 or Tween 80

Azurin which is a bacterial secondary metabolite has attracted much attention as potential anticancer agent in recent years. This copper-containing periplasmic redox protein supresses the tumor growth selectively. High-level secretion of proteins into the culture medium offers a significant advantage over periplasmic or cytoplasmic expression. The aim of this study was to investigate the effect of nonionic surfactants on the expression of the Pseudomonas aeruginosa azurin. Different concentrations of Triton X-100 and Tween 80 were used as supplements in growth media and extracellular azurin production was stimulated by both surfactants. According to western blot analysis results, in the presence of Triton X-100, maximum azurin expression level was achieved with 96 h of incubation at 1% concentration, and 48 h at 2% concentration. On the other hand, maximum azurin expression level was achieved in the presence of 1% Tween 80 at 72 h incubation. This study suggested for the first time a high level of azurin secretion from P. aeruginosa in the presence of Triton X-100 or Tween 80, which would be advantageous for the purification procedure.