Mutations in genes encoding antibiotic substances increase the synthesis of poly-γ-glutamic acid in Bacillus amyloliquefaciens LL3.
Mutations in genes encoding antibiotic substances increase the synthesis of poly-γ-glutamic acid in Bacillus amyloliquefaciens LL3.
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编码抗生素物质的基因突变增加了解淀粉芽孢杆菌 LL3 中聚-γ-谷氨酸的合成
DOI：
10.1002/mbo3.398
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发表时间：
2017-02
期刊：
影响因子：
3.4
通讯作者：
Yang C
中科院分区：
文献类型：
--
作者：
Gao W;Liu F;Zhang W;Quan Y;Dang Y;Feng J;Gu Y;Wang S;Song C;Yang C
聚γ-谷氨酸（γ-PGA）是一种重要的天然生物高分子，广泛应用于食品、医药、化妆品、农业等领域。构建了几种解淀粉B. amyloliquefaciens LL 3突变体，以通过编码抗生素物质的四个基因簇（itu、txD、srf和fen）的单个或多个无标记框内缺失来改善γ-PGA合成。Δsrf突变株的γ-PGA合成（4.1 g/L）与野生型菌株（3.3 g/L）相比略有增加。ΔituΔsrf突变体的γ-PGA产量从3.3 g/L增加到4.5 g/L，增加了36.4%。ΔituΔsrfΔfen和ΔituΔsrfΔfenΔ fen突变体的γ-PGA产率未显示进一步增加。研究了这四个基因簇在蜂群运动和生物膜形成中的作用。Δsrf和Δ srf突变株在群集运动中均存在显著缺陷，表明芽孢杆菌素和表面活性素参与解淀粉B. amyloliquefaciens LL 3的群集运动。此外，Δsrf和Δitu突变株在生物膜形成方面存在明显缺陷，因此iturin和surfitin在解淀粉B. amyloliquefaciens LL 3生物膜形成中起重要作用。
Poly‐γ‐glutamic acid (γ‐PGA) is an important natural biopolymer that is used widely in fields of foods, medicine, cosmetics, and agriculture. Several B. amyloliquefaciens LL3 mutants were constructed to improve γ‐PGA synthesis via single or multiple marker‐less in‐frame deletions of four gene clusters (itu, bae, srf, and fen) encoding antibiotic substances. γ‐PGA synthesis by the Δsrf mutant showed a slight increase (4.1 g/L) compared with that of the wild‐type strain (3.3 g/L). The ΔituΔsrf mutant showed increased γ‐PGA yield from 3.3 to 4.5 g/L, with an increase of 36.4%. The γ‐PGA yield of the ΔituΔsrfΔfen and ΔituΔsrfΔfenΔbae mutants did not show a further increase. The four gene clusters’ roles in swarming motility and biofilm formation were also studied. The Δsrf and Δbae mutant strains were both significantly defective in swarming, indicating that bacillaene and surfactin are involved in swarming motility of B. amyloliquefaciens LL3. Furthermore, Δsrf and Δitu mutant strains were obviously defective in biofilm formation; therefore, iturin and surfactin must play important roles in biofilm formation in B. amyloliquefaciens LL3.