一株产脂肪酶菌株的筛选、鉴定及酶性质的研究

Isolation, identification and the enzyme properties research of a lipase producing strain

本文对从土样中筛选出具有产脂肪酶的菌株Yz12进行显微镜检及分子鉴定，探索不同因素对菌株YZ12产酶条件的影响以及菌株Yz12酶学性质。结果表明，菌株Yz12最适温度为30℃；最适pH为8．0；碳源为橄榄油与蔗糖（3：1）；氮源为（NH4）2SO4与牛肉膏（1：2）以及最佳发酵时间为72h。Yz12脂肪酶最适温度为30℃；最适pH为7．0；Ca2＋能促进Yz12脂肪酶的活力。经镜检及分子鉴定后，确定菌株Yz12为米曲霉Aspergillus oryzae。

To isolate and screen a strain Yz12 with high efficiency lipase from the soil sample, the isolation of Yz12 was carried out by microscopic examination and molecular identification. The influence of different factors on the production of Yz12 was studied, and the properties of Yz12 were determined. The most suitable temperature was 30. The optimal pH was 8. Carbon source was good for olive oil and sucrose （3：1）, nitrogen source for ammonium sulfate and beef extract （1：2）. The optimal fermentation time was 72h. Yzl2 lipase activity was the most suitable temperature of 30. The best pH was 7. Ca2＋ can promote the activity of Yzl2 lipase. After microscopic examination and molecular identification, the strain Yzl2 was identified as Aspergillus oryzae.