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Factors affecting the production and molecular weight of levan in enzymatic synthesis by recombinant Bacillus subtilis levansucrase SacB‐T305A
Polymer International ( IF 2.9 ) Pub Date : 2020-08-31 , DOI: 10.1002/pi.6112
Yuanyuan Hou 1, 2, 3 , Fei Huang 1, 2 , Hui Yang 1, 2 , Hao Cong 1, 2 , Xi Zhang 1, 2 , Xiaoxu Xie 1 , Haibo Yang 1 , Qiuping Tong 1, 2 , Ning Luo 1, 2 , Ping Zhu 1 , Jianzong Meng 1
Affiliation  

Levansucrase (EC 2.4.1.10) catalyzes both levan polymerization and sucrose hydrolysis. Levan production by recombinant Bacillus subtilis levansucrase SacB‐T305A was investigated. The maximum conversion yield (33.09%) of sucrose to levan and levan yield (115.8 g L–1) were obtained as 30% (wt/vol) and 40% (wt/vol) initial sucrose, respectively. Under highly acidic conditions (pH 3.5 and below), the polymerization not only shifted distinctly to high molecular weight levan but also enlarged the size of low molecular weight levan. In particular, the proportion of high molecular weight levan to total products increased to 9‐fold at pH 3.5. The presence of Fe2+, Mg2+, Mn2+ and Zn2+ ions at common ion strength (5 mmol L–1) increased only the size of low molecular weight levan from about 20 kDa to about 35 kDa. Our findings provide a supplementary view about the mechanism of levan molecular weight distribution in enzymatic synthesis and offer a possibility for producing levan of different molecular weights by modulating enzymatic reaction conditions. © 2020 Society of Industrial Chemistry

中文翻译:

重组枯草芽孢杆菌Levansucrase SacB-T305A酶促合成中Levan产量和分子量的影响因素

Levansucrase(EC 2.4.1.10)催化levan聚合和蔗糖水解。研究了重组枯草芽孢杆菌Levansucrase SacB-T305A产生的Levan 。蔗糖最大转化率(33.09%)转化为左蔗糖和左聚糖产率(115.8 g L –1)分别为初始蔗糖的30%(wt / vol)和40%(wt / vol)。在高酸性条件下(pH 3.5及以下),聚合反应不仅明显转移到高分子量左聚糖上,而且扩大了低分子量左芬的大小。特别是在pH 3.5时,高分子量levan在总产品中所占的比例增加到9倍。Fe 2 +,Mg 2 +,Mn 2+和Zn 2+的存在普通离子强度(5 mmol L –1)的离子仅将低分子量levan的大小从约20 kDa增加到约35 kDa。我们的发现提供了关于在酶促合成中莱万分子量分布机理的补充观点,并提供了通过调节酶促反应条件来产生不同分子量的莱万的可能性。©2020工业化学学会
更新日期:2020-08-31
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