Enhancement of Thermostable Lipase Production by a Genotypically Identified Extremophilic <i>Bacillus subtilis</i> NS 8 in a Continuous Bioreactor

Abstract

Bacillus strain NS 8, a lipase-producing bacterium isolated from a Malaysian hot spring, is able to tolerate a broad range of temperature and pH, which makes it beneficial for this study. It generated PCR products with molecular weight of 1,532 bp, and the 16S rRNA sequence analysis identified it as Bacillus subtilis with accession number AB110598. It showed a 71% similarity index with B. subtilis using Biolog Microstation System. Its lipase production was optimized using a shake flask system by changing the physical (agitation speed, pH and temperature) and nutritional (nitrogen, carbon and minerals) factors. The most suitable combination of the basal medium for lipase production was 2.5% olive oil (carbon), 1.5% peptone (nitrogen), 0.1% MgSO₄ (mineral) at an optimum temperature of 50°C, pH 7.5 and 150 rpm agitation, giving an enzyme yield of 4.23 U/ml. Statistical optimization using response surface methodology was carried out. An optimum lipase production of 5.67 U/ml was achieved when olive oil concentration of 3%, peptone 2%, MgSO₄·7H₂O 0.2% and an agitation rate of 200 rpm were combined. Lipase production was further carried out inside a 2-liter bioreactor, which yielded an enzyme activity of 14.5 U/ml after 15 h of incubation.

Effects of probiotics, oligosaccharides, and berberine combinationson growth performance of pigs

“…This study showed that combinations of probiotics, oligosaccharides, and/or berberine could significantly increase fecal lipase, protease, and amylase activity to some extent. The reason may be that the probiotics can produce these enzymes or stimulate endogenic excretion (21). It was reported that diets supplemented with probiotics could significantly improve carbohydrate digestibility in the small intestine (22).…”

Delipidation of Chicken Feathers by Lipolytic Bacillus Species Isolated from River-Borne Sediments

“…An increased agitation speed beyond the optimum could create shear forces that negatively impact the cell biomass integrity, which therefore affects the enzyme productivity [54]. Likewise, other studies have shown that lipase production by Bacillus licheniformis [55] and B. subtilis [56] was optimum at 140 rpm and 150 rpm, respectively. The size of the starter culture influences enzyme production by bacterial strains; overpopulation of the culture medium at the inception of fermentation could be a limiting factor in terms of the optimal enzyme yield, as this might result in the quick depletion of nutrients and dissolved oxygen [47].…”