The coexisting mechanism of a synthetic bacterial community (SBC) was investigated to better understand how to manage microbial communities. The SBC was constructed with three kinds of phenol-utilizing bacteria, Pseudomonas sp. LAB-08, Comamonas testosteroni R2, and Cupriavidus sp. P-10, under chemostat conditions supplied with phenol as a sole carbon and energy source. Population densities of all strains were monitored by real-time quantitative PCR (qPCR) targeting the gene encoding the large subunit of phenol hydroxylase. Although the supply of phenol was stopped to allow perturbation in the SBC, all of the strains coexisted and the degradation of phenol was maintained for more than 800 days. The qPCR analyses showed that strains LAB-08 and R2 became dominant simultaneously, whereas strain P-10 was a minor population. This phenomenon was observed before and after the phenol-supply stoppage. The kinetic parameters for phenol of the SBC changed before and after the phenol-supply stoppage, which suggests a change in functional roles of strains in the SBC. Transcriptional levels of phenol hydroxylase and catechol dioxygenases of three strains were monitored by reverse-transcription qPCR (RT-qPCR). The RT-qPCR analyses revealed that all strains shared phenol and survived independently before the phenol-supply stoppage. After the stoppage, strain P-10 would incur the cost for degradation of phenol and catechol, whereas strains LAB-08 and R2 seemed to be cheaters using metabolites, indicating the development of the metabolic network. These results indicated that it is important for the management and redesign of microbial communities to understand the metabolism of bacterial communities.

为了更好地了解如何管理微生物群落，对合成细菌群落（SBC）的共存机制进行了研究。SBC由三种利用酚的细菌Pseudomonas sp。构建。LAB-08，Comamonas testosteroni R2和Cupriavidussp。P-10，在化学稳定状态下，苯酚作为唯一碳和能源提供。通过实时定量PCR（qPCR）监测所有菌株的种群密度，该实时定量PCR靶向编码苯酚羟化酶大亚基的基因。尽管停止了苯酚的供应以允许SBC发生干扰，但所有菌株共存，苯酚的降解保持了800天以上。qPCR分析表明，菌株LAB-08和R2同时占优势，而菌株P-10则为少数。在苯酚供应停止之前和之后都观察到了这种现象。SBC苯酚的动力学参数在苯酚供应停止之前和之后发生了变化，这表明菌株在SBC中的功能作用发生了变化。通过逆转录qPCR（RT-qPCR）监测三个菌株的苯酚羟化酶和儿茶酚双加氧酶的转录水平。RT-qPCR分析显示，所有菌株均共享苯酚，并在苯酚供应停止之前独立存活。停药后，菌株P-10将招致苯酚和邻苯二酚降解的费用，而菌株LAB-08和R2似乎是利用代谢产物的作弊剂，表明了代谢网络的发展。这些结果表明，了解微生物群落的代谢对于微生物群落的管理和重新设计很重要。P-10菌株将招致苯酚和邻苯二酚降解的费用，而LAB-08和R2菌株似乎是利用代谢产物的作弊剂，表明了代谢网络的发展。这些结果表明，了解微生物群落的代谢对于微生物群落的管理和重新设计很重要。P-10菌株将招致苯酚和邻苯二酚降解的费用，而LAB-08和R2菌株似乎是利用代谢产物的作弊剂，表明了代谢网络的发展。这些结果表明，了解微生物群落的代谢对于微生物群落的管理和重新设计很重要。