Culture optimizations and application for Bacillus amyloliquefaciens Z16 to produce neutral protease

The enzyme- producing conditions of Bacillus amyloliquefaciens Z16 and the technological conditions of aqueous enzymatic extraction of camphor tree seed kernel oil were optimized by using single- factor experiment and orthogonal experiment,meanwhile,compared with the Bacillus subtilis AS1.398.The best fermentation medium composition of Bacillus amyloliquefaciens Z16 was corn meal 4.5%,wheat bran 2.5%,soya bean meal 4.0%,Ca Cl₂0.2%,KH₂PO₄ 0.03%,Na₂HPO₄· 12H₂ O 0.4%,p H7.5,and the best fermentation conditions of Bacillus amyloliquefaciens Z16 were inoculation amount 2%,temperature 37 ℃,rate 220 r / min,shake flask culture 44 h.Under the best enzyme- producing technological conditions,the activity of neutral protease produced by Bacillus amyloliquefaciens Z16 was 6984.3 U / m L,which was raised by 54.0% after the optimization.The optimum conditions of of Bacillus amyloliquefaciens Z16 aqueous enzymatic extraction of camphor tree seed kernel oil were enzyme adding proportion 20%( v / v),enzymolysis time 4 h. The corresponding camphor tree seed kernel oil yield was91.1%,and its acid value only rose by 0.3 mg KOH / m L. The effect of Bacillus amyloliquefaciens Z16 on aqueous enzymatic extraction of camphor tree seed kernel oil was obviously superior to Bacillus subtilis AS1.398 commonlyused to produce neutral protease.