摘要
Fructansucrase and fructan produced from Lactobacillus fermentum AKJ15 were isolated from seeds of Kodo ko jaanr, a fermented mild-alcoholic beverage prepared in North East India. The strain was identified by 16S rRNA gene sequence analysis and biochemical characterization. The strain displayed maximum fructansucrase activity of 4.3 U/ml (1.02 U/mg) at 28°C at 180 rpm. The enzyme purified by polyethylene glycol-400 gave specific activity of 5 U/mg and showed 90 kDa band on non-denaturing Sodium Dodecyl Sulphate-Poly Acrylamide Gel Electrophoresis (SDS-PAGE). The purified enzyme confirmed the presence of fructan by periodic acid Schiff's staining which showed magenta colour bands with both sucrose and raffinose. The strain produced 10.2 mg/ml fructan in broth under optimized culture conditions. The purified fructansucrase displayed Vmax of 5.42 U/mg and Km of 16.65 mM. The enzyme showed maximum activity at 30°C and at pH 5. The structure of fructan was analysed by 1H and 13C NMR spectra confirming β-(2-1) and β-(2-6) linkages.
摘要译文
由发酵乳酸杆菌AKJ15产生的果糖蔗糖和果聚糖是从印度东北部制备的发酵的低度酒精饮料Kodo ko jaanr的种子中分离出来的。通过16S rRNA基因序列分析和生物化学表征鉴定菌株。该菌株在28℃，180rpm下显示最大的果糖蔗糖酶活性为4.3U / ml（1.02U / mg）。通过聚乙二醇-400纯化的酶在非变性十二烷基磺酸钠 - 聚丙烯酰胺凝胶电泳（SDS-PAGE）上具有5U / mg的比活性和90kDa的条带。纯化的酶通过过碘酸Schiff''''s染色确认果聚糖的存在，其显示品红色带有蔗糖和棉子糖。产生的菌株10。2mg / ml果聚糖在优化的培养条件下发酵液中。纯化的果糖蔗糖酶显示出V max为5.42U / mg，K m为16.65mM。该酶在30℃和pH 5下显示出最大活性。通过1 H和13 C NMR谱分析确认β-（2-1）和β-（2-6）连接的果聚糖的结构。
Arijita Dutta[1];Deeplina Das[1];Arun Goyal[2]. Purification and characterization of fructan and fructansucrase from Lactobacillus fermentum AKJ15 isolated from Kodo ko jaanr, a fermented beverage from north-eastern Himalayas[J]. International Journal of Food Sciences and Nutrition, 2012,63(2): 216-224