Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan.
Appl Environ Microbiol. 2013 Aug;79(16):4845-52. doi: 10.1128/AEM.01209-13. Epub 2013 Jun 7.
Burkholderia unamae CK43B, a member of the Betaproteobacteria that was isolated from the rhizosphere of a Shorea balangeran sapling in a tropical peat swamp forest, produces neither indole nor extracellular polymeric substances associated with biofilm formation. When cultured in a modified Winogradsky's medium supplemented with up to 1.7 mM indole, B. unamae CK43B maintains its planktonic state by cell swelling and effectively degrades exogenous indole. However, in medium supplemented with 1.7 mM exogenous indole and 1.0 mM gallic acid, B. unamae CK43B produced extracellular polymeric substances and formed a biofilm. The concentration indicated above of gallic acid alone had no effect on either the growth or the differentiation of B. unamae CK43B cells above a certain concentration threshold, whereas it inhibited indole degradation by B. unamae CK43B to 3-hydroxyindoxyl. In addition, coculture of B. unamae CK43B with indole-producing Escherichia coli in nutrient-rich Luria-Bertani medium supplemented with 1.0 mM gallic acid led to the formation of mixed cell aggregates. The viability and active growth of B. unamae CK43B cells in a coculture system with Escherichia coli were evidenced by fluorescence in situ hybridization. Our data thus suggest that indole facilitates intergenus communication between indole-producing gammaproteobacteria and some indole-degrading bacteria, particularly in gallic acid-rich environments.
伯克霍尔德氏菌属（Burkholderia）unamae CK43B，β变形菌的一个成员，它从热带泥炭沼泽森林中一种 Shorea balangeran 树苗的根际中分离出来，既不产生吲哚，也不产生与生物膜形成有关的细胞外聚合物。当在补充有高达 1.7 mM 吲哚的改良 Winogradsky 培养基中培养时，B. unamae CK43B 通过细胞肿胀保持其浮游状态，并有效地降解外源性吲哚。然而，在补充有 1.7 mM 外源性吲哚和 1.0 mM 没食子酸的培养基中，B. unamae CK43B 产生细胞外聚合物并形成生物膜。上述浓度的没食子酸单独使用时，在超过一定浓度阈值后，对 B. unamae CK43B 细胞的生长或分化均没有影响，而它会抑制 B. unamae CK43B 将吲哚降解为 3-羟基吲哚。此外，在补充有 1.0 mM 没食子酸的营养丰富的 Luria-Bertani 培养基中，将 B. unamae CK43B 与产吲哚的大肠杆菌共培养会导致混合细胞聚集体的形成。通过荧光原位杂交证实了 B. unamae CK43B 细胞在与大肠杆菌的共培养系统中的活力和活性生长。我们的数据表明，吲哚促进了产吲哚的γ变形菌和一些吲哚降解菌之间的属间通讯，特别是在富含没食子酸的环境中。
