초록
<P>Thermostable lipases are potential enzymes for biocatalytic application. In this study, the lipase production of Geobacillus sp. CF03 (WT) was improved by genome shuffling. After two rounds of genome shuffling, one fusant strain (FB1) achieved increase lipase activity from the populations generated by ultraviolet irradiation and ethyl methylsulfonate (EMS) mutagenesis. The growth rate and lipase production of FB1 increased highest by 150 and 238?%, respectively, in comparison to the wild type. The fusant enzyme had a significant change in substrate specificity but still prefers the long-chain length substrates. It had an optimum activity at 60?C, pH at 7.0-8.0, with p-nitrophenyl palmitate (C16) as a substrate and retained about 50?% of their activity after 15?min at 70?C, pH 8.0. Furthermore, the fusant lipase showed the preference of sesame oil, waste palm oil, and canola oil. Therefore, the genome shuffling strategy has been successful to strain improvement and selecting strain with multiple desirable characteristics.</P>