Fachbereich Biologie, Mikrobielle Ökologie, Universität Konstanz, Konstanz, Germany.
FEMS Microbiol Lett. 2012 Jan;326(1):69-75. doi: 10.1111/j.1574-6968.2011.02435.x. Epub 2011 Nov 3.
In this study, interactions between bacteria possessing either released or cell-associated enzymes for polymer degradation were investigated. For this, a co-culture of Aeromonas hydrophila strain AH-1N as an enzyme-releasing bacterium and of Flavobacterium sp. strain 4D9 as a bacterium with cell-associated enzymes was set up with chitin embedded into agarose beads to account for natural conditions, under which polymers are usually embedded in organic aggregates. In single cultures, strain AH-1N grew with embedded chitin, while strain 4D9 did not. In co-cultures, strain 4D9 grew and outcompeted strain AH-1N in the biofilm fraction. Experiments with cell-free culture supernatants containing the chitinolytic enzymes of strain AH-1N revealed that growth of strain 4D9 in the co-culture was based on intercepting N-acetylglucosamine from chitin degradation. For this, strain 4D9 had to actively integrate into the biofilm of strain AH-1N. This study shows that bacteria using different chitin degradation mechanisms can coexist by formation of a mixed-species biofilm.
在这项研究中，研究了具有释放酶或细胞相关酶的细菌之间的相互作用，用于聚合物降解。为此，将气单胞菌 AH-1N 菌株作为释放酶的细菌和黄杆菌 4D9 菌株作为具有细胞相关酶的细菌与嵌入琼脂糖珠中的几丁质进行共培养，以模拟聚合物通常嵌入有机聚集体的自然条件。在单一培养物中，菌株 AH-1N 可以在嵌入的几丁质上生长，而菌株 4D9 则不能。在共培养物中，菌株 4D9 在生物膜部分生长并竞争过菌株 AH-1N。使用含有菌株 AH-1N 的几丁质酶的无细胞培养上清液进行的实验表明，菌株 4D9 在共培养物中的生长是基于从几丁质降解中拦截 N-乙酰葡萄糖胺。为此，菌株 4D9 必须主动整合到菌株 AH-1N 的生物膜中。本研究表明，使用不同几丁质降解机制的细菌可以通过形成混合物种生物膜而共存。
