Hierarchy of Carbon Source Utilization in Soil Bacteria: Hegemonic Preference for Benzoate in Complex Aromatic Compound Mixtures Degraded by Cupriavidus pinatubonensis Strain JMP134
Hierarchy of Carbon Source Utilization in Soil Bacteria: Hegemonic Preference for Benzoate in Complex Aromatic Compound Mixtures Degraded by Cupriavidus pinatubonensis Strain JMP134
复制标题
DOI：
10.1128/aem.04207-14
复制
发表时间：
2015-06-01
影响因子：
4.4
通讯作者：
Gonzalez, Bernardo
中科院分区：
文献类型：
--
作者：
Perez-Pantoja, Danilo;Leiva-Novoa, Pablo;Gonzalez, Bernardo
与许多其他环境细菌一样，Pinatubonensis JMP 134使用一系列芳香族化合物作为碳源。以前的报道表明，当这种细菌在由这种芳香族化合物和4-羟基苯甲酸酯或苯酚组成的二元混合物上生长时，它对苯甲酸酯有偏好。然而，这一观察尚未扩展到其他类似于更典型背景的芳香混合物。本文系统地研究了C. pinatubonensis JMP 134生长在代表性的芳香族化合物上，这些芳香族化合物通过好氧细菌中描述的不同分解代谢途径被引导。生长测试的几乎整个设置的二元组合和混合物组成的5或6个芳香族组分表明，苯甲酸酯和苯酚总是首选和推迟的生长底物，分别。动力学分析支持这种模式，表明芳香族化合物混合物中苯甲酸酯的起始消耗时间较短。通过实时逆转录-PCR（RT-PCR）的基因表达分析表明，在所有的混合物中，苯甲酸酯对其他分解代谢途径的抑制主要在转录水平上发挥作用。此外，抑制苯甲酸催化剂表明，其多种抑制作用不是由单一的机制介导的，如在不同的芳香族化合物混合物中有效抑制苯甲酸降解的不同要求所表明的。对苯甲酸盐超过多种芳族碳源的霸权偏好不能基于每个单一基质上的生长速率和/或生物质产率或通过这些芳族化合物的明显化学或代谢性质来解释。
Cupriavidus pinatubonensis JMP134, like many other environmental bacteria, uses a range of aromatic compounds as carbon sources. Previous reports have shown a preference for benzoate when this bacterium grows on binary mixtures composed of this aromatic compound and 4-hydroxybenzoate or phenol. However, this observation has not been extended to other aromatic mixtures resembling a more archetypal context. We carried out a systematic study on the substrate preference of C. pinatubonensis JMP134 growing on representative aromatic compounds channeled through different catabolic pathways described in aerobic bacteria. Growth tests of nearly the entire set of binary combinations and in mixtures composed of 5 or 6 aromatic components showed that benzoate and phenol were always the preferred and deferred growth substrates, respectively. This pattern was supported by kinetic analyses that showed shorter times to initiate consumption of benzoate in aromatic compound mixtures. Gene expression analysis by real-time reverse transcription-PCR (RT-PCR) showed that, in all mixtures, the repression by benzoate over other catabolic pathways was exerted mainly at the transcriptional level. Additionally, inhibition of benzoate catabolism suggests that its multiple repressive actions are not mediated by a sole mechanism, as suggested by dissimilar requirements of benzoate degradation for effective repression in different aromatic compound mixtures. The hegemonic preference for benzoate over multiple aromatic carbon sources is not explained on the basis of growth rate and/or biomass yield on each single substrate or by obvious chemical or metabolic properties of these aromatic compounds.