Influence of Surface Active Agents on Detergent Tolerance of Lipases

Abstract

Although it has already been reported that anionic detergents (AD) strongly inhibited the activity of lipase, scarce data is available on their influence in the presence of surface active agents (PSA). This report deals the influence of PSA on detergent tolerance of lipases. Three microbial lipases of Achromobacter sp., Candida sp. and Mucor sp., and an animal lipase of hog pancreas were used. Anionic detergents included sodium dodecyl benzene sulfonate (DBS), sodium dodecyl sulfonate (SDS) and sodium stearate (SOAP). 12 kinds of surface active agents selected from cationic, nonionic and amphoteric surface active agents were tested for their protection of lipases. The influence of PSA were examined by assaying the residual lipase activity according to modified Dole's method after the contact of lipase solution with the mixture of AD and PSA. Results obtained were as follows : 1. The inhibition of microbial lipase activity by DBS and SDS was protected by the addition of nonionic PSA such as Tween and Emulgen (polyoxyethylene nonylphenylether), but in case of animal lipase, Ameate was the only PSA which was found to be effective to protect the activity. On the contrary, the inhibition of microbial lipase activity by SOAP was not protected by any PSA but most of the nonionic PSA protected animal lipase.2. This protective effect of PSA, with some exception, increased as concentration of lipase and PSA increased and decreased along the increse of the concentration of AD. The temperature and the time at the contract reversely affected to their protective effect.3. Lipases of Candida sp. and Mucor sp. were unstable in the presence of salts which are usually used as bilders, whereas lipases of hog pancreas and Achromobacter sp. were comparatively stable. Tolerance of lipase activity in commercial detergents also increased by the addition of PSA.