Organic-solvent and surfactant tolerant thermostable lipase, isolated from a thermophilic bacterium, geobacillus thermodenitrificans IBRL-nra

Abstract

Lipases (triacylglycerol acylhydrolase, EC 3.1.1.3), catalyze the hydrolysis of long-chain triglycerides with the formation of diacylglyceride, monoglyceride, glycerol and fatty acids. Lipases are actively used in various industries which include food and diary, pharmaceuticals, organic synthesis and detergent and cosmetics. Thermostable lipases are commercially significant for their potential use in industries as it is stable and active in organic solvents and resistance to high temperature and chemical denaturation. The production of thermostable lipase from Geobacillus thermodenitrificans IBRL-nra was carried out in a shake-flasks system at 65 ºC in cultivation medium containing (%; w/v or v/v): glucose 1.0; yeast extract 1.25; NaCl 0.45 and olive oil 0.1 with agitation of 200 rpm for 24 hours. The extracted extracellular crude thermostable lipase was purified to homogeneity by using ultrafiltration, Heparin-affinity chromatography and Sephadex G-100 gel-filtration chromatography by 34 folds with a final yield of 9%. The molecular weight of the purified enzyme was estimated to be 30 kDa after SDS-PAGE analysis. Purified thermostable lipase exhibited highest stability in the presence of acetone, ethanol and acetonitrile after 1h and 24h of incubation periods. Thermostable lipase showed elevated activity (220%) when pre-treated with Triton X-100 and could withstand 100% of its activity in the presence of protease up to 4 hours and could retain 70% of its initial activity after 24 hours of incubation.

Medium-based optimization of an organic solvent-tolerant extracellular lipase from the isolated halophilic Alkalibacillus salilacus

“…In addition, Na 2 HPO 4 at lower level was used at optimized medium. These results agreed somewhat with the previous researches (Balan et al 2013;Burkert et al 2004;Cheng et al 2011;Ebrahimpour et al 2008;Gupta et al 2007;Mahanta et al 2008;Mehta et al 2012). The reason for the difference between various reports is probably due to the characteristic of the each strain.…”

“…Generally, biomass and lipase production is enhanced by sources containing nitrogen especially organic nitrogen sources, which supply powerful source of nitrogen for the growth of bacteria and increases their yields of proteins. These findings confirm relevant data reported in similar studies (Balan et al 2013;Burkert et al 2004;Cheng et al 2011;Ebrahimpour et al 2008;Mahanta et al 2008;Mehta et al 2012;Zaliha et al 2006).…”

“…This result was also followed by sunflower and sesame oils. High levels of lipase production were reported from various microorganisms in the presence of olive oil as carbon source (Ahmed et al 2010;Balan et al 2013;Burkert et al 2004;Gupta et al 2007;Mehta et al 2012;Zaliha et al 2006). Most published experimental data have shown that lipid carbon sources especially natural oils stimulate lipase production, whereas carbon sources that are easily broken down and used by bacteria, have an inhibitory effect and contradict the results obtained by many studies (Burkert et al 2004;Gupta et al 2007;Volpato et al 2008;Zaliha et al 2006).…”

Use of Yarrowia lipolytica Lipase Immobilized in Cell Debris for the Production of Lipolyzed Milk Fat (LMF)

“…Polar solvents having LogP value less than 2 cause enzyme inactivation because they compete with the enzyme for water molecules. Therefore, water is removed from the enzyme causing protein unfolding, making it unstable [31]. Y. lipolytica is known to have 16 different putative lipase genes, out of which YLIP2 is the main extracellular lipase and most studied one.…”

Cloning, Expression, and Biochemical Characterization of an Enantioselective Lipase, YLIP9, from Yarrowia lipolytica MSR80

“…In most of the cases, it has been reported that solvents having LogP value less than 2 result in enzyme inactivation. The polar solvents compete with the enzyme for water molecules and thus strip off water from the enzyme leading it to unfold and making it unstable [24]. Interestingly, a very different property was observed for ZZ-YLIP9 in that it was more stable as well as its activity was highly enhanced in the presence of solvents with logP less than 0.05, i.e., very hydrophilic solvents (2-propanol, ethanol, acetone, 1,4-dioxane).…”