The Function of β-1,4-Glucuronosyltransferase WelK in the Sphingan WL Gum Biosynthesis Process in Marine Sphingomonas sp. WG
The Function of β-1,4-Glucuronosyltransferase WelK in the Sphingan WL Gum Biosynthesis Process in Marine Sphingomonas sp. WG
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β-1,4-葡萄糖醛酸基转移酶 WelK 在海洋鞘氨醇鞘氨醇 WL 胶生物合成过程中的功能。
DOI：
10.1007/s10126-020-09998-9
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发表时间：
2020-09-26
影响因子：
3
通讯作者：
Zhu, Hu
中科院分区：
文献类型：
--
作者：
Li, Hui;Li, Kehui;Zhu, Hu
对鞘氨醇单胞菌产的海洋多糖WL胶进行了研究。WG在油墨、食品和石油工业中显示出商业实用潜力。预测β-1，4-葡糖醛酸基转移酶WelK在WL胶生物合成过程中催化葡糖醛酸从UDP-葡糖醛酸转移到葡糖基-α-焦磷酸基聚戊烯醇中间体。通过生物信息学分析、基因敲除和过表达策略来评估其功能。与野生型菌株相比，突变株welK在培养48 h时，WL产胶量和肉汤粘度分别降低了71.5%和99.2%。基因破坏导致产品制备失败。在天然生物中同源表达welK可有效提高WL胶产量。当葡萄糖浓度为6.7%时，welK过表达菌株培养60 h和84 h时WL胶产量分别为野生菌的32.65和43.13 g/L，分别为野生菌的134.1%和114%。多糖组成和qRT-PCR分析表明，葡萄糖醛酸含量与welK的表达水平密切相关，因此，welK在WL胶合成中起着关键作用，有望成为代谢工程的一个有吸引力的靶点。本实验为鞘氨醇单胞菌基因的功能鉴定提供了一种遗传操作方法。WG.
The marine-derived polysaccharide WL gum produced bySphingomonassp. WG showed commercial utility potential in ink, food, and oil industries. A beta-1,4-glucuronosyltransferase WelK was predicted to catalyze the transfer of glucuronic acid from UDP-glucuronic acid to glucosyl-alpha-pyrophosphorylpolyprenol intermediate in the WL gum biosynthesis process. Its function was evaluated by bioinformatical analysis, gene knocking out, and overexpressing strategies. Compared to the wild strain, the WL gum production and broth viscosity of the mutant increment welK were decreased by 71.5% and 99.2% when cultured for 48 h. The gene disruption led to the failure of product preparation. Homologous expression ofwelKin the native organism can effectively improve WL gum production. When glucose concentration was 6.7%, the WL gum production by the welK-overexpressing strain cultured for 60 h and 84 h reached 32.65 and 43.13 g/L, 134.1%, and 114% of the wild strain. The polysaccharide composition and qRT-PCR analysis showed that the glucuronic acid content was closely related to the expression level ofwelK.Thus, WelK was proved to play a critical role in the WL gum synthesis and will be an attractive target for metabolic engineering. Our experiment provided a genetic manipulation method for the functional characterization of genes inSphingomonassp. WG.