One bacterial strain was isolated from soil as alkaline lipase producing microoganism.
Isolated strain was identified as Pseudomonas pseudoalcaligenes.
When this strain was cultivated in medium containing soybean meal extract and olive oil, this secreted a large amount of alkaline lipase. This strain showed maximum lipase production at 32℃ and at pH 10.0 in 3days. Sodium acetate and sodium citrate was effective carbon source for lipase production, whereas glycerol decreased the lipase production remarkably. Soybean meal extract as nitrogen source was more effective than any others used. The lipase was inducibly produced in the presence of oil.
The extracellular lipase was purified treating ammonium sulfateprecipitation and applying the chromatography on Sephadex G-150 and DEAE-Sephacel column. The lipase was purified from culture broth 3.6 fold giving a yield of 15.6% and purified enzyme was homogeneous on SDS-polyacrylamide gel electrophoresis. The molecular weight to the lipase was estimated to be 80,000-85,000 under reducing conditions.
The purified enzyme was most active at pH 10.5 and 50℃. The lipase was stable between pH 8 and 11, while more than 70% of enzyme activity remained after incubation 65℃ for 30min. The activity was inhibited by iron ions. It was affected by bile salt.
내알카리성 리파제를 생산하는 균주를 자연계로부터 순수분리하여 동정하였다. 이 균주는 Pseudomonas pseudoalcaligenes와 유사하였으며 대두박, 올리브유를 포함하는 배지에서 다량의 리파제를 생성했다. 기초배지에서 여러 영양원을 변화시켜 리파제 생산성을 조사하였으며 생산된 리파제를 분리, 정제하였다. 정제 완료후 15.6%의 수율을 갖는 3.6배의 정제된 효소를 얻었으며 SDS-PAGE를 이용해 순수함을 확인하였다. 이효소는 pH 10.5에서 가장높은 역가를 보였으며 pH 8-11 사이에서 높은 안정성을 나타냈다. 온도 50℃ 에서 최적활성을 보였으며 55℃ 까지는 안정하였다. 철 이온은 효소역가를 감소시켰으며, 담즙산은 농도가 낮을때는 효소의 역가를 증진시키나 높을때는 감소시켰다.
