ABSTRACT: Bacterial biofilms play an important role in marine biofouling. The formation of a biofilm starts when marine bacterial cells transition from a planktonic to an attached state. However, the molecular mechanisms involved in this transition are poorly understood. Here, 51 strains of marine bacteria were isolated from natural biofilms growing on submerged artificial surfaces (glass slides, epoxy panels, and bridge pillars) and evaluated for their biofilm-forming capacity. Eleven strains formed relatively strong biofilms and 16S rRNA gene sequence analysis indicated that they belonged to the genera Leisingera, Roseobacter, Pseudoalteromonas, Alteromonas, Tenacibaculum, Vibrio, Chryseobacterium, Aquimarina, and Acinetobacter. Strain Pseudoalteromonas sp. W-7 showed efficient and rapid attachment and was therefore chosen for further study. An iTRAQ-based comparative proteomic analysis of planktonic and attached strain W-7 cells was carried out. A total of 3468 proteins were identified, of which 163 showed significant differential expression (120 down-regulated and 43 up-regulated in attached cells relative to planktonic cells). KEGG (Kyoto encyclopedia of genes and genomes) analysis indicated that pyruvate metabolism, carbon fixation, and carbon metabolism were significantly affected in attached cells. Up-regulated proteins such as UTP-glucose-1-phosphate uridylyltransferase, acetyltransferase component of pyruvate dehydrogenase complex, OmpA-like protein, and acetyl-coenzyme A synthetase may be important during initial adhesion. Our findings provide a deeper understanding of the planktonic to sessile transition of marine fouling bacteria.

中文翻译：

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使用比较蛋白质组学分析洞察海洋生物膜形成假拟变单胞菌分离物中的浮游向无柄过渡

摘要：细菌生物膜在海洋生物污染中起着重要作用。当海洋细菌细胞从浮游状态转变为附着状态时，便开始形成生物膜。但是，这种转变涉及的分子机制了解甚少。在这里，从水下生物膜（玻璃片，环氧树脂板和桥柱）上生长的天然生物膜中分离出51种海洋细菌菌株，并对其生物膜形成能力进行了评估。11株形成相对强的生物膜和16S rRNA基因序列分析表明，它们属于下列属Leisingera，Roseobacter，假交替单胞，互生单胞，黏着，弧菌，金黄，Aquimarina，和不动杆菌。伪假单胞菌菌株sp。W-7表现出高效，快速的依附性，因此被选作进一步研究。进行了基于iTRAQ的浮游细胞和附着的W-7细胞株的比较蛋白质组学分析。鉴定出总共3468种蛋白质，其中163种蛋白质显示出显着的差异表达（相对于浮游细胞，在附着细胞中有120种下调，有43种上调）。KEGG（基因和基因组京都百科全书）分析表明，丙酮酸代谢，碳固定和碳代谢在附着细胞中受到显着影响。上调的蛋白，例如UTP-葡萄糖-1-磷酸尿酸基转移酶，丙酮酸脱氢酶复合物的乙酰基转移酶组分，OmpA样蛋白和乙酰辅酶A合成酶在最初黏附过程中可能很重要。