产纤溶酶菌株的筛选鉴定及其生长条件研究

Screening and Identification of Strain Producing Plasmin and its Growth Conditions

从酱醅、豆豉原料中筛选高产纤溶酶的菌株,并对其进行鉴定和生长条件的研究。通过酪蛋白平板法初筛和液态发酵复筛,从酱醅、豆豉原料中筛选出1株纤溶酶活力达1 960 U/mL的高产菌株M64。通过个体形态、菌落特征及生理生化特征将其鉴定为枯草芽孢杆菌纳豆亚种。通过研究液体培养条件对菌株生长的影响,确定菌种液体培养的条件为接种量1.5%,初始pH值7,转速160 r/min,培养温度37℃,培养时间10 h。

To screen the strain with high yield of plasmin from soy sause mash and Douchi,and its growth conditions is studied.The strain M64 with 1 960 U/mL of plasmin activity is screened from soy sause mash and Douchi by Casein plate primirily selecting and lipid state fermentation second screening.By individual form,colony characteristic and physiological and biochemical property,the strain is identified as Bacillus subtilis natto.By researching the effect of conditons on growth,the growth conditons of inoculum concentration 1.5%,initial pH 7.0,rotating speed 160 r/min,cultivating at 37 ℃ for 10 h is determined.