Efficient production of polymalic acid from xylose mother liquor, an environmental waste from the xylitol industry, by a T-DNA-based mutant of Aureobasidium pullulans
Efficient production of polymalic acid from xylose mother liquor, an environmental waste from the xylitol industry, by a T-DNA-based mutant of Aureobasidium pullulans
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利用基于 T-DNA 的出芽短梗霉突变体，从木糖母液（木糖醇工业产生的环境废物）中高效生产聚苹果酸
DOI：
10.1007/s00253-019-09974-x
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发表时间：
2019-08-01
影响因子：
5
通讯作者：
Zou, Xiang
中科院分区：
文献类型：
--
作者：
Feng, Jun;Li, Tianfu;Zou, Xiang
聚苹果酸（PMA）是由出芽短梗霉（Aureobasidiumpullulans）产生的一种可生物降解的高分子化合物，在环境领域具有潜在的应用价值。在这项工作中，从基于T-DNA的突变体库中筛选出PMA高产突变体FJ-D2，其PMA滴度增加12.9%，这归因于糖基转移酶基因（celA）的表达降低，导致纤维素生物合成减少39.5%。木糖醇工业产生的环境废弃物木糖母液（WXML）未经处理，可直接用作PMA生产的经济底物。FJ-D2菌株在5L发酵罐中分批发酵，其PMA效价为57.1 ± 0.02g/L，最高MA产量为0.77g/g混合糖。此外，与乙二胺四乙酸（EDTA）相比，PMA具有相当的镉（Cd）去除效率（EDTA为88.7%，PMA为86.0%），这是没有发现在L-苹果酸（MA）单体的单体。这些结果表明，PMA是一种环境友好和可生物降解的土壤修复螯合剂。此外，我们的研究结果提供了一个经济上有竞争力的过程PMA生产可再生的环境废物。
Polymalic acid (PMA) is a biodegradable polymer produced by the polyextremotolerant fungiAureobasidium pullulansand has been shown to have potential applications in environmental fields. In this work, a high PMA yield mutant FJ-D2 was screened from T-DNA-based mutant libraries and showed a 12.9% increase in PMA titers, which was attributed to decreased the expression of a glycosyltransferase gene (celA), resulting in a 39.5% reduction in cellulose biosynthesis. Untreated waste xylose mother liquor (WXML), an environmental waste generated from the xylitol industry, can be directly used as an economical substrate for PMA production. Using batch-fermentation of FJ-D2, the PMA titer of 57.1 ± 0.02 g/L was produced in a 5-L fermentor, with the highest MA yield of 0.77 g/g mixed sugar. Furthermore, compared with ethylenediaminetetraacetic acid (EDTA), PMA had a comparable cadmium (Cd) removal efficiency (88.7% for EDTA versus 86.0% for PMA), which was not found in the monomer of L-malic acid (MA) monomers. These findings indicated that PMA was an environmentally friendly and biodegradable chelator for soil remediation. Moreover, our results provided an economically competitive process for PMA production from renewable environmental wastes.