Cloning and characterization of newly isolated lipase from Enterobacter sp. Bn12

Abstract

A mesophilic Enterobacter sp. Bn12 producing an alkaline thermostable lipase was isolated from soil in Tehran, Iran. The lipase gene (ELBn12) was identified from a genomic library. Sequence analysis of the DNA fragment revealed an open reading frame of 879 bp encoding a lipase with a molecular mass of 31.3 kDa. The deduced amino acid sequence showed 96% identity with a lipase of Enterobacter sp. Ag1 and the identity of their DNA sequences was 88.9%. ELBn12 belongs to the lipase subfamily I.1 and its catalytic triad consists of Ser82, Asp237 and His259. The lipase was expressed in Escherichia coli (BL21) pLysS and partially purified by anion exchange chromatography. The maximum activity of ELBn12 was obtained at temperature of 60 °C and pH 8.0 towards tricaprylin (C8) and its specific activity was around 2900 U/mg. ELBn12 was stable within a broad pH range from 6.0 to 11.0. The enzyme showed high stability in both polar and nonpolar organic solvents at 50% (v/v). The lipase activity was enhanced in the presence of 10 mM of Ca2+, Mg2+ and K+, while heavy metals (Fe3+ and Zn2+) had strong inhibitory effect. ELBn12 showed high activity in the presence of 1% (w/v) nonionic surfactants, however ionic surfactants inhibited the lipolytic activity. ELBn12 characteristics show that it has a potential to be used in various industrial processes.

Realm of Thermoalkaline Lipases in Bioprocess Commodities

“…(i.e., strain AU07, BK44), Pseudomonas sp., and Enterobacter sp. Bn12 [ 21 , 27 , 61 ]. On the other hand, fungus strains producing TA lipases such as Talaromyces thermophilus , Trichoderma atroviride 676, Curvularia sp.…”

“…In SFC, the production of TA lipase from C. freundii IIT-BT L139 was optimized via OFAT [ 34 ]. A very high TA lipase IIT-BT L139 activity (8.8 U/ml) can be obtained at optimal temperature, pH, carbon, and nitrogen sources of 40°C, 9.0, starch, and peptone-urea, respectively, as evaluated via OFAT [ 34 , 61 ]. When TA lipase IIT-BT L139 was produced via 1 L and 10 L STB (without pH and DOT controlled during fermentation), the activity was found to increase by 36% (12 U/ml) as compared to SFC [ 34 ].…”

Role of Q177A and K173A/Q177A substitutions in thermostability and activity of the ELBn12 lipase

“…Generally, in the case of surfactants, the activity of the Q177A lipase increased in the presence of nonionic surfactants (1% w/v) and decreased in the ionic ones (Table ), similar to the native and K173A lipases . The K173A/Q177A lipase also showed the same activity pattern, whereas Triton X‐100 had no significant effect on its activity.…”

Production of thermostable multiple enzymes from Bacillus amyloliquefaciens KUB29

“…Os cinco isolados lipolíticos apresentaram atividade enzimática ideal em toda a faixa de temperatura avaliada (10-80 °C), mostrando versatilidade de atuação tanto em temperaturas altas quanto baixas. Noormohamadi R e colaboradores 2013 (Farrokh P, Yakhchali B, Karkhane AA, 2014).…”