[Study on low-temperature alkaline lipase from Bohaisea-9145].

Lipase-overproducing marine yeast Bohaisea-9145 isolated from the Bohai sea region was identified as psychrotrophlic Yarrowia lipolytica. The optimum composition of culture medium was ground soybean 4%, rice bran 4%, peanut power 4%, crude peanut oil 0.5%, MgSO 4 0.05%,KH 2PO 4 0.2%. The optimum temperature and pH were 26±1℃、pH5.0, the time of fermentation cycle was 23h. The lipase activity was improved to 258.67U/mL through optimization, four-fold more than that of initial strain. The lipase displayed maximum activity at pH 8.5, 35℃ and was stable within the range of pH 4.0～9.0 at low temperature. It had high thermosensitivity, good compatibility with familiar metal ions and chemical reagents. It was antioxidant and had strong resistance to high salinity. As a novel marine low-temperature lipase, it has promising prospect in many fields, especially as an additive of detergent.