Enhanced production of thermostable lipase from Bacillus cereus ASSCRC-P1 in waste frying oil based medium using statistical experimental design

Ghada Awad,Hanan Mostafa,Enas Danial,Hassan Awad,Nayera Abdelwahed

doi:10.7324/japs.2015.50902

Abstract

This study aim to isolate, identify and optimize lipase producing strains using frying oil waste. Nine strains were isolated from an Egyptian soil samples. Among the isolates, a potent bacterial candidate ASSCRC-P1 was found to be the most potent lipase producer strain at 60 °C. Genotypic identification of ASSCRC-P1 showed 94% similarity with Bacillus sp. strains. Phylogenetic tree confirmed that ASSCRC-P1 was nearly similar to Bacillus cereus. Therefore, it was given the name Bacillus cereus ASSCRC-P1 and its 16S rRNA nucleotide has been deposited in the GenBank Data Library under the accession number: KJ531440. A sequential optimization strategy, based on statistical experimental designs, was employed to enhance the lipase production by this strain. A 2-level Plackett–Burman design was applied to differentiate between the bioprocess parameters that significantly influence lipase production followed by Box-Behnken design to optimize the amounts of variables which have the highest positive significant effect on lipase production. Overall more than 2.15-fold improvement in lipase production was achieved due to optimization compared to that obtained using the basal medium.

Highlights

Lipases are widely distributed among microorganisms, animals and plants and they catalyze the hydrolysis of esters of long chain aliphatic acids from glycerol at lipid and water interfaces (Jensen 1983)
These results were more than that obtained from several researchers as Guzman and Virginia (2008) who detected lypolytic activity of 0.079 U/ml by Bacillus pumilus LV01 isolated from water samples and maximum lipase production of 12 U/ml by Pseudomonas gessardii selected from a soil sample (Veerapagu et al, 2013)
These results were in accordance to Boonmahome and Mongkolthanaruk (2013) who found that Pseudomonas aeruginosa isolate NA37 selected from soil contaminated with oil in Khon Kaen region showed high lipase activity (190 mU/ml) detecting with p-nitrophenyl palmitate as a substrate

Summary

Introduction

Lipases (triacylglycerol acylhydrolases; EC 3.1.1.3) are widely distributed among microorganisms, animals and plants and they catalyze the hydrolysis of esters of long chain aliphatic acids from glycerol at lipid and water interfaces (Jensen 1983). Lipases are produced by several microorganisms, viz., bacteria, fungi, yeast, actinomycetes, archea, eucarya, etc. Microbial genera involved in the commercial production of lipases include: Candida, Mucor, Rhizopus, Aspergillus, Penicillium, Geotrichum, Rhizomucor, Bacillus, Pseudomonas and Staphylococcus (Aravindan et al, 2007). Microorganisms with potentials for producing lipases can be found in different habitats, including wastes of vegetable oils and dairy industries, soils contaminated with oils, seeds, and deteriorated food (Sharma et al, 2001). These oils can be considered a high-energy food source, till used/discharged for animal feed, but they may be considered as high-energy source for microbial growth and transformation into high-value products (Haba et al, 2000).

Objectives

Methods

Results

Conclusion