【摘要】 对仿刺参Apostichopus japonicus消化道内容物进行富集培养,以琼胶为惟一碳源进行平板初筛,摇瓶复筛,得到一株琼胶酶活性较高的菌株HF3。对该菌株进行紫外线诱变,获得突变菌株HF3-04,酶活力从43.0 U/mL增加到48.9 U/mL,提高了13.7%。通过正交试验,确定培养基的最佳组成为:琼胶3 g/L,硝酸铵1 g/L,磷酸氢二钠0.5 mmol/L,pH值8.0;最佳培养条件为:接种量为1%,250 mL三角瓶中发酵培养基的装液量为110 mL,摇床转速为150 r/m in,培养温度为25℃,培养时间为48 h。将培养基组成及培养条件优化后,菌株酶活力达到80.7 U/mL,比优化前提高了65.0%。更多还原

【Abstract】 A bacterial agarase-producing strain HF3 was isolated from digestive tracts in sea cucumber Apostichopus japonicus by enrichment culture,first-screened by agar plate containing agar as main carbon source and second-screened by shaking culture.The strain HF3 was treated with UV for screening of high agarase-producing mutant.The mutant HF3-04 had an increase activity of agarase from 43.0 U/mL to 48.9 U/mL,13.7% higher than the control,and the higher production of the agarase was continued thereafter for five generations.The optimal culture media for HF3-04 strain producing agarase was determined by single factor test and orthogonal test and was found as the following: agar 3 g/L,NH4NO3 1 g/L,Na2HPO4 ·12H2O 0.5 mmol/L,and pH 8.0.The optimal fermentation conditions were observed as the following: inoculum volume 1%,110 mL medium in 250 mL Erlenmeyer flask,shaking speed 150 r/min,culture temperature 25 ℃ and culture period 48 h.The HF3-04 had agarase activity of 80.7 U/mL,65.0% higher when it was incubated in optimal fermentation conditions.更多还原