A neutral lipase applicable in biodiesel production from a newly isolated Streptomyces sp. CS326.

In an attempt to isolate a biocatalyst able to catalyze biodiesel production from microbial source, Streptomyces sp. CS326 was screened from hundreds of soil isolates collected from various parts of Korea. In 16S rRNA sequence analysis, the strain showed high degree of similarity with Streptomyces xanthocidicus (99.79%); therefore, it is classified as Streptomyces sp. CS326. An extracellular lipase produced by the strain (LP326) was purified using a single step gel permeation chromatography on Sepharose CL-6B. Molecular weight of LP326 was estimated to be 17,000 Da by SDS-PAGE. The activity was optimum at 40 °C and pH 7.0 and was stable at pH 5.0-8.0 and below 50 °C. It preferred p-nitrophenyl palmitate (C16), a long chain substrate; and K (m) and V (max) for the substrate were determined to be 0.24 mM and 4.6 mM/min mg, respectively. First 10 N-terminal amino acid sequences were APDLVALQSE, which are different from so far reported lipases. LP326 catalyzed biodiesel production using methanol and various oils; therefore, the enzyme can be applicable in the field of biofuel.