产菊粉酶菌株的筛选及产酶条件优化

Screening of inulinase production strain and optimization of fermentation condition

摘要: 从盐碱地菊芋根际土壤中筛选出112株产菊粉酶菌株,并从中得到一株酶活较高的真菌A-6,经菌落观察以及采用真菌通用引物ITS1和ITS4 PCR扩增RNA基因序列,测序鉴定结果为烟曲霉Aspergillus fumigatus。对其产酶条件进行单因素分析结果显示,真菌A-6的pH耐受范围较广,且具有一定的耐盐性。经正交实验进行产酶条件优化,确定了A-6的最佳产酶条件为菊芋提取液（EJA）100g/L,酵母膏（YE）25g/L,NaCl为5g/L,NH4H2PO45g/L,pH为5,30℃,170r/min下振荡培养3d,酶活最高为13.29U/mL。

Abstract: 112 strains producing inulinase were isolated from rhizosphere soil of Jerusalem artichoke in the salt -affected land. Strain A-6 was obtained and identified as Aspergillus fumigatus through observing its shape of individual bacterial colony and amplified the rRNA gene sequence using fungal universal primers ITS1 and ITS4. The effect of different factors on its enzyme production shown A-6 had a wide pH range and it could tolerate the high concentration of NaCl. After analysis of orthogonal design, the optimum condition for higher inulinase production of A-6 was determined:EJA 100g/L, YE 25g/L, NaCl 5g/L, NH4H2PO4 5g/L, pH5, 3d of growth under 30℃ and 170r/min in shake cultures. Maximal inulinase activity of A-6 was 13.29U/mL.