中温碱性脂肪酶的研究 Ⅰ.高产菌株——扩展青霉PF868的选育

Studies on Alkaline-Mesophile Lipase I. Breeding of High Producing Strain from Penicillium expansun

以扩展青霉(Penicillium expansum)uN-503作为出发菌株,经UV,DES和NTG多代诱变,选育成功产酶水平高达1200u/ml的优良变株——扩展青霉PF868,其酶活力较出发菌株提高了111%;连续传代10次PF868变株的产酶性能并没有衰退,是一个稳定的变株;PF868变株产酶的最适碳氮源和pH与出发菌株有显著的差异;其酶学特性与出发菌株相比也得到显著改善,最适作用温度由42℃降至32℃,更加适合于洗涤剂和工业脱脂用酶的要求.

Penicillium expansum PF868, a high producing strain of alkaline lipase, was obtained through mutation breeding by UV., DES and NTG from the original strain penicillium expansum UN-503. The lipase activity of strain PF868 reached 1200u/ml, which was 2.1 times as much as that of the original strain UN -503 The mutant strain PF868 was still stable in producing lipase through incu-bating continually ten generations. The results showed that there were differences between the mutant and the original strain in conditions for lipase production and lipase properties. The optimal temperature for lipase activity from the mutant PF868 was 32℃, while the original strain was 42℃. This suggested that the lipase from the mutant PF868 be more suitable than that of the original for the use of detergent and leather degreasing.