Tai Vera, Paulsen Ian T, Phillippy Katherine, Johnson D Aaron, Palenik Brian
Marine Biology Research Division, Scripps Institution of Oceanography, University of California - San Diego, La Jolla, CA 92093-0202, USA.
Environ Microbiol. 2009 Oct;11(10):2698-709. doi: 10.1111/j.1462-2920.2009.01997.x. Epub 2009 Jul 30.
Microbes live in diverse communities yet their physiologies are typically studied in axenic culture. To begin to address this dichotomy, whole-genome microarray analyses were used and revealed that several major metabolic pathways were affected in Synechococcus sp. WH8102, a model phototroph, when grown with Vibrio parahaemolyticus, a model heterotroph. In co-cultures with V. parahaemolyticus, although phosphate was not depleted, Synechococcus sp. WH8102 may have experienced phosphate stress since the expression of phosphate acquisition genes increased and alkaline phosphatase activity was higher than in monocultures. Expression of cell wall synthesis genes and the components of a zinc transporter were also upregulated. In contrast, a ferric uptake regulation (Fur) family gene was downregulated as were genes that encode proteins rich in iron or involved in detoxifying oxygen radicals. Nitrogen use may also have been affected in co-cultures as the gene expression changes share similarities with ammonia-grown Synechococcus. This study demonstrates the multiple impacts that interspecific microbial interactions can have on the physiology of a major primary producer and the importance of investigating microbial physiology from a community perspective.
微生物生活在多样的群落中，但其生理学研究通常是在无菌培养条件下进行的。为了开始解决这一矛盾，研究人员使用了全基因组微阵列分析，结果显示，当模式光合生物聚球藻属（Synechococcus sp.）WH8102与模式异养生物副溶血性弧菌（Vibrio parahaemolyticus）共同培养时，其几个主要代谢途径受到了影响。在与副溶血性弧菌的共培养中，尽管磷酸盐没有耗尽，但聚球藻属WH8102可能经历了磷酸盐胁迫，因为磷酸盐获取基因的表达增加，且碱性磷酸酶活性高于单培养。细胞壁合成基因和锌转运蛋白组分的表达也上调了。相反，铁摄取调节（Fur）家族基因以及编码富含铁的蛋白质或参与清除氧自由基的蛋白质的基因表达下调。共培养中的氮利用也可能受到了影响，因为基因表达变化与氨培养的聚球藻有相似之处。这项研究证明了种间微生物相互作用对主要初级生产者生理学可能产生的多重影响，以及从群落角度研究微生物生理学的重要性。
