Wood Thammajun L, Gong Ting, Zhu Lei, Miller James, Miller Daniel S, Yin Bei, Wood Thomas K
1Department of Chemical Engineering, Pennsylvania State University, University Park, PA 16802 USA.
2Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802 USA.
NPJ Biofilms Microbiomes. 2018 Oct 3;4:22. doi: 10.1038/s41522-018-0066-1. eCollection 2018.
Biofilm formation is an important problem for many industries. is the representative sulfate-reducing bacterium (SRB) which causes metal corrosion in oil wells and drilling equipment, and the corrosion is related to its biofilm formation. Biofilms are extremely difficult to remove since the cells are cemented in a polymer matrix. In an effort to eliminate SRB biofilms, we examined the ability of supernatants from PA14 to disperse SRB biofilms. We found that the . supernatants dispersed more than 98% of the biofilm. To determine the biochemical basis of this SRB biofilm dispersal, we examined a series of . mutants and found that mutants , , , and , defective in rhamnolipids production, had significantly reduced levels of SRB biofilm dispersal. Corroborating these results, purified rhamnolipids dispersed SRB biofilms, and rhamnolipids were detected in the . supernatants. Hence, . supernatants disperse SRB biofilms via rhamnolipids. To determine the genetic basis of how the . supernatants disperse SRB biofilms, a whole transcriptomic analysis was conducted (RNA-seq); based on this analysis, we identified four proteins (DVUA0018, DVUA0034, DVUA0066, and DVUA0084) of the . megaplasmid that influence biofilm formation, with production of DVUA0066 (a putative phospholipase) reducing biofilm formation 5.6-fold. In addition, the supernatants of . dispersed the SRB biofilms more readily than protease in M9 glucose minimum medium and were also effective against biofilms of and .
生物膜形成是许多行业面临的一个重要问题。[具体细菌名称]是导致油井和钻井设备金属腐蚀的代表性硫酸盐还原菌（SRB），其腐蚀与生物膜形成有关。由于细胞被固定在聚合物基质中，生物膜极难去除。为了消除SRB生物膜，我们检测了[具体细菌名称]PA14的上清液分散SRB生物膜的能力。我们发现，[具体细菌名称]PA14的上清液能分散超过98%的生物膜。为了确定这种SRB生物膜分散的生化基础，我们检测了一系列[具体细菌名称]突变体，发现鼠李糖脂产生缺陷的突变体[具体编号1]、[具体编号2]、[具体编号3]和[具体编号4]的SRB生物膜分散水平显著降低。这些结果得到了证实，纯化的鼠李糖脂能分散SRB生物膜，并且在[具体细菌名称]PA14的上清液中检测到了鼠李糖脂。因此，[具体细菌名称]PA14的上清液通过鼠李糖脂分散SRB生物膜。为了确定[具体细菌名称]PA14的上清液如何分散SRB生物膜的遗传基础，我们进行了全转录组分析（RNA测序）；基于此分析，我们在[具体细菌名称]的大质粒上鉴定出四种影响生物膜形成的蛋白质（DVUA0018、DVUA0034、DVUA0066和DVUA0084），其中DVUA0066（一种假定的磷脂酶）的产生使生物膜形成减少了5.6倍。此外，在M9葡萄糖基本培养基中，[具体细菌名称]PA14的上清液比蛋白酶更易于分散SRB生物膜，并且对[其他细菌名称1]和[其他细菌名称2]的生物膜也有效。
