Studies on the extremo-lipase produced by the halotolerant Oceanobacillus iheyensis strain QCS

Noura Sh A Hagaggi

doi:10.21608/nrmj.2020.107542

Abstract

In the current work, different studies were carried out on the lipase enzyme produced by the halotolerant Oceanobacillus iheyensis strain QCS, with an expectation to be an important candidate in the industrial applications. Lipase of strain QCS was halo-alkali-thermo-detergent-solvent stable. Maximum production of lipase was obtained after 72 h of incubation, at 40oC and pH 8 and 9 in a medium containing 25 % (w/v) NaCl and 1% (v/v) olive oil as a lipid substrate. This lipase was partially purified, highest lipase activity was obtained in 80% ammonium sulfate saturation, and in fraction eight of the Sephadex G-200 gel filtration chromatography. Lipase displayed wide spectrum of activity within a broad range of conditions including salinity, temperature and pH, it was optimally active at 25% (w/v) NaCl, 40°C and pH 8 and 9, respectively. The effect of many metal ions, detergents and organic solvents on the activity of lipase was evaluated. Interestingly, lipase was able to retain the majority of its activity in the presence of Ni2+, Mg2+, Oxi and Fairy detergents, ethyl acetate, dimethyl formamide and toluene, respectively. Overall, as the lipase from O. iheyensis strain QCS has a number of interesting properties especially its stability at extreme conditions; it could be used as a potential promising candidate for detergents industry, and as a biocatalyst in low water enzymatic processes.

Highlights

Among the most important widely distributed extremophilic microorganisms are the halophilic bacteria that can survive in hypersaline environments (Aljohny, 2015; Mohammadipanah et al, 2015)
According to Oren, (2010), the halophilic bacteria are recognized as producers of polysaccharides, polyhydroxyalkanoate, carotenoid pigments, Hagaggi, 2020 compatible solutes and hydrolytic enzymes of great industrial importance
The objectives of the present study were to optimize, purify and describe the extracellular lipase produced by the extremely halotolerant Oceanobacillus iheyensis strain QCS, with the expectation that such lipase will be an important candidate in the industrial applications

Summary

Introduction

Among the most important widely distributed extremophilic microorganisms are the halophilic bacteria that can survive in hypersaline environments (Aljohny, 2015; Mohammadipanah et al, 2015). De Lourdes Moreno et al, (2013) added that the diversity of halophilic bacteria could produce several hydrolytic enzymes including; protease, lipase, amylase, cellulase, xylanase and DNase that have many applications in the different fields of industry These enzymes are stable at high salt concentrations and can efficiently function under extreme conditions (Kumar et al, 2012). A recent study conducted by Karray et al, (2018) added that the capacity of the halophilic bacteria to make cost-effective fermentation with minimum sterile precautions through their hydrolytic enzymes; is an interesting research topic Due to their stability, high activity in presence of organic solvents and their broad substrate range, the lipases produced by halophilic bacteria are used in various biotechnological applications including; waste treatment, textile, food as well as detergents industries (De Lourdes Moreno et al, 2013; Schreck and Grunden 2014). The objectives of the present study were to optimize, purify and describe the extracellular lipase produced by the extremely halotolerant Oceanobacillus iheyensis strain QCS, with the expectation that such lipase will be an important candidate in the industrial applications

Objectives

Methods

Results