产有机相催化酯合成活性的脂肪酶菌株的筛选

Screening of Lipase-producing Strain for Catalytic Synthesis of Ester in Organic Media

摘要:

通过添加10g/L的甲苯作为唯一碳源进行预培养,然后以透明圈平板筛选法从土壤样品中成功地筛选到了一株耐有机溶剂的产脂肪酶的酵母菌A213,初步鉴定为耶罗威亚酵母(Yarrowia sp．)。摇瓶实验表明,A213适宜的产酶培养基为(g/L):酵母膏40g,橄榄油10g,MgSO₄·7H₂O 1g,KH₂PO₄5g,最佳培养条件为27℃、初始pH 6．5。脂肪酶活力最高可达67．8 IU/mL;该酶最适作用温度为40℃,最适作用pH为6．5,在70℃以下, pH 5．5～8．5范围内稳定,能直接在叔戊醇溶剂中催化合成L-抗坏血酸棕榈酸酯。

Abstract:

An organic solvent tolerant isolate A213 originating from soil samples were successfully isolated via direct plating method using 10g/L of toluene as the sole carbon source and transparent cycle plate assay method.It was identified as Yarrowia based on its characteris- tics.The results in shake flask cultivation showed that the suitable tipase producing media were(g/L):yeast extract 40,vegetable oil 10, MgSO₄·7H₂O1,KH₂PO₄ 5.Under optimal culture conditions (27℃and pH 6.5 ),the maximal lipase activity could reach 67.8 IU/mL.The optimal pH and temperature for the hydrolysis of p-nitrophenyl acetate by crude lipase were pH6.5 and 40℃. The enzyme was sta-ble under 70℃ and pH5.5～8.5. Then isolate A213 was found to produce the lipase which can synthesize L-ascorbyl palmitate in tert-amyl alcohol validaed by the thin-layer chromatography.