Production and optimization of process conditions of lipase using bacteria isolated from meat

Abstract

The production of commercial enzymes, including lipase from bacteria has always been the industrial choice due to its economic and commercial feasibility. This study investigated the potential of Bacillus sp. strain AT-b3 and Acinetobacter baumani strain SL 100 for lipase production using meat. A number of seven (7) lipase producing bacterial isolates were identified from Four (4) samples collected from different meat sellers in Sokoto Modern Abattoir. The bacterial isolates from meat were screened for lipase production on a sterile olive oil with phenol red agar. The heterotrophic plate count (CFU/g) revealed that Sample C had the highest bacterial population. Microscopic examination of the isolates shows that the samples consist of both gram positive and gram negative bacteria. Based on morphology, the isolates are Rod shape (Bacilli), Cocci and intermediate Cocco-bacilli. The isolates include: Bacillus sp., Streptococcus sp., Acinetobacter sp., Klebsiella sp., Lactobacillus sp., etc. Out of seven (7) bacteria isolated and screened, three (3) were positive for lipase production by showing visible precipitates as a result of degradation of fatty acids. Molecular identification through 16S rRNA sequencing confirmed Bacillus sp. strain AT-b3 and Acinetobacter baumani strain SL 100 as the most potent isolates for lipase production. Optimization studies were conducted using the One-Factor-at-a-Time (OFAT) method to determine the ideal fermentation conditions. The results showed that the optimal temperature for lipase production was 40°C for Bacillus sp. strain AT-b3 and 50°C for Acinetobacter baumani strain SL 100. pH optimization revealed that pH 8 was ideal for maximizing lipase production for both isolates, with Acinetobacter baumani strain SL 100 outperforming Bacillus sp. strain AT-b3 at this pH. Substrate concentration studies indicated that 2.0% of substrate was optimal for lipase production, and incubation time optimization identified 48 hours as the optimal period for maximum yield. The results of the titrimetric assay showed an average of 13.93U/ml of lipase activity after 24 hrs of incubation at 37 °C with highest activity recorded from Sample A (Bacillus sp. strain AT-b3), lipase as 25.00 U/ml. This study concludes that Bacillus sp. strain AT-b3 and Acinetobacter baumani strain SL 100 showed capabilities in lipase production, and that lipase enzymes could be promising biocatalyzing agents in industries. Further research is recommended to explore pilot-scale production, alternative substrates, and comprehensive safety assessments.