초록
<P><B>Abstract</B></P> <P>Nowadays, finding a talented lipase with high potency in biodiesel production has been attracted to researchers. In this study, an extracellular salt tolerant, cold-active and organic solvent-stable lipase producing bacterium was isolated from oil-contaminated environments located in Kerman province (Iran) and identified as <I>Bacillus licheniformis</I> KM12. Lipase was purified by 36.0% recovery and molecular weight was estimated about 33 kDa by SDS–PAGE. The optimal pH and temperature for lipase activity were found to be 8.0 and 35 °C, respectively. Lipase activity was remarkably increased about 37% after 20 min incubation at 20 °C. <I>K</I>m value of KM12 lipase was 0.53 mM for p-nitrophenyl palmitate (p-NPP) and maximum activity was detected for pNP-decanoate and glyceryl-decanoate substrates. KM12 lipase displayed significant stability in different organic solvents after 7 and 21 days of incubation, especially in polar organic solvents. Biodiesel production with 78% yields was achieved with the one-step addition of methanol at around 18 h by using <I>Myrtus</I> oil (as a non-edible oils feedstocks). These unique properties of KM12 lipase make it talented as a potential biocatalyst for biodiesel production.</P> <P><B>Highlights</B></P> <P> <UL> <LI> KM12 is a novel cold-active lipase from <I>B. licheniformis</I>. </LI> <LI> It is an organic solvent-tolerant lipase. </LI> <LI> Purified lipase showed the favorite on medium- and long-chain esters. </LI> <LI> High stability of purified KM12 observed at different ions and detergents. </LI> <LI> Myrtus oil is a non-edible oils feedstocks for biodiesel production. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>