Partial purification, characterization and immobilization of a novel lipase from a native isolate of Lactobacillus fermentum

Abstract

Background and Objectives: Due to the widespread use of lipase enzymes in various industries, finding native lipase pro- ducing microorganisms is of great value and importance. In this study, screening of lipase-producing lactobacilli from native dairy products was performed.
 Materials and Methods: Qualitative evaluation of lipolytic activity of lipase-producing lactobacilli was performed in differ- ent media containing olive oil. A clear zone observation around the colonies indicated the lipolytic activity. The strain with the highest enzymatic activity was identified. Determination of optimal pH and temperature of lipase activity was measured by spectrophotometry using p-nitrophenyl acetate (ρ-NPA) substrate. Partial purification of lipase enzyme was performed using 20-90% saturation ammonium sulfate. Eventually, lipase was immobilized by physical adsorption on chitosan beads.
 Results: Among screened lipolytic bacterial strains, one sample (5c isolate) which showed the highest enzymatic activity (5329.18 U/ml) was close to Lactobacillus fermentum. During characterization, the enzyme showed maximum activity in Tris-HCl buffer with pH 7, while remaining active over a temperature range of 5°C to 40°C. The results of the quantitative assay demonstrated that the fraction precipitated in ammonium sulfate at 20% saturation has the highest amount of lipolytic activity, with a specific activity of 22.0425 ± 3.6 U/mg. Purification folds and yields were calculated as 8.73 and 44%, respec- tively. Eventually, the enzyme was immobilized by physical adsorption on chitosan beads with a yield of 56.21%.
 Conclusion: The high efficiency of enzyme immobilization on chitosan beads indicates the suitability of this method for long-term storage of new lipase from native 5c isolate.

Bacillus subtilis Produces Amino Acids to Stimulate Protein Synthesis in Ruminal Tissue Explants via the Phosphatidylinositol-4,5-Bisphosphate 3-Kinase Catalytic Subunit Beta–Serine/Threonine Kinase–Mammalian Target of Rapamycin Complex 1 Pathway

“…In the present study, the addition of fetal bovine serum was found to be more favorable for the increase in explant activity, which was confirmed by Alan et al who concluded that the addition of fetal bovine serum was beneficial in delaying the loss of explant activity (40). Furthermore, the results of the rumen explant activity assay showed that the optimal incubation time for rumen explants in dairy cows was 12 h, which is lower than the 24 h reported in other studies (38). This may be the result of differences between sheep and cow species, as sheep rumen epithelial cells can continuously and stably pass through generations.…”

“…Thus, this model was deemed suitable to address the objectives of the present study. Furthermore, the results of the rumen explant activity assay showed that the optimal incubation time for rumen explants in dairy cows was 12 h, which is lower than the 24 h reported in other studies (38). This may be the result of differences between sheep and cow species, as sheep rumen epithelial cells can continuously and stably pass through generations.…”