Screening and identification of strains for aqueous enzymatic extraction of medium-chain triglycerides

Strains which had ability of higher neutral protease and lower lipase production,resistance to mediumchain fatty acids,was the key to improve yield and quality of camphor tree seed kernel oil by aqueous enzymatic extraction technology. Strain Z16 was isolated from waste residue in camphor tree seed kernel oil by screening methods(camphor tree seed kernel plate for enrichment,skim milk and oil medium plate for primary screening,Folin phenol and camphor tree seed kernel oil medium shaking for re-screening). The results showed that neutral protease and lipase production capability of Z16 were 4536.5 U/m L and 0.088 U/m L, respectively.Z16 was identified as Bacillus amyloliquefaciens by morphological, physiological and 16 S r DNA. Bacillus amyloliquefaciens had maximum neutral protease activity at 50 ℃,and was activated by Mn2 +. The optimum temperature and p H for neutral protease were 40~45 ℃ and 7.0,respectively.