New Lipase for Biodiesel Production: Partial Purification and Characterization of LipSB 25-4.
The lipolytic activities of 300 Streptomyces isolates were determined in Tributyrin and Rhodamine-B Agar. Lipase activities were also measured with p-nitrophenyl palmitate (p-NPP) as a substrate. The strain of Streptomyces bambergiensis OC 25-4 used in this study was selected among 300 strains of Streptomyces from MUCC as the best lipase producer. The incubation conditions were optimized and the inoculum amount, incubation period, effect of carbon and nitrogen sources, and rates of MgSO4 and CaCO3 were investigated. LipSB 25-4 (the lipase produced by S. bambergiensis OC 25-4 strain) was partially purified with ammonium sulphate precipitation, dialysis, and gel filtration chromatography 2.73-fold and with 92.12 U/mg specific activity. The optimal pH and temperature for LipSB 25-4 were determined as 8.0 and 50°C, respectively. The lipase has high stability in all pH and temperature values used in this study. While LipSB 25-4 was slightly activated in the presence of β-mercaptoethanol, it was slightly reduced by PMSF. The enzyme conserved approximately 75% of its activity at the end of 60 h, in the presence of methanol and ethanol. Since LipSB 25-4 displays high activity in the thermophilic conditions and stability in the presence of organic solvents, this lipase can catalyse the biodiesel production from olive oil by the transesterification reactions.
Section of Medical Microbiology, Department of Basic Sciences, Faculty of Dentistry, Gazi University, TR06510 Ankara, Turkey.
Aysel
0000-0002-5188-1106
A
Ugur
Department of Biology, Faculty of Sciences, Mugla Sıtkı Kocman University, TR48000 Mugla, Turkey.
Nurdan
0000-0001-7676-542X
N
Sarac
Medical Laboratory Program, Vocational School of Health Service, Aksaray University, TR68000 Aksaray, Turkey.
Rukiye
0000-0003-2395-2445
R
Boran
Department of Biology, Faculty of Sciences, Mugla Sıtkı Kocman University, TR48000 Mugla, Turkey.
Berk
B
Ayaz
Apiculture Program, Vocational School of Ula Ali Kocman, Mugla Sıtkı Koçman University, TR48640 Mugla, Turkey.
Ozgur
O
Ceylan
Department of Biology, Faculty of Sciences, Mugla Sıtkı Kocman University, TR48000 Mugla, Turkey.
Gulten
G
Okmen