Extracellular polymeric substances (EPS) are present externally to the microorganisms and play an important role in attachment and biofilm formation. These polymers possess antibacterial and antifouling activities. In this study, the antifouling activity of EPS produced by an epibiotic bacterium associated with macroalga Ulva lactuca was assessed against fouling bacteria and barnacle larvae. Results indicate that the EPS isolated from the epibiotic bacterium inhibits the biofilm formation of the bacteria without much antibacterial activity. Also, the EPS reduced the settlement of barnacle larvae on the hard substrate under laboratory conditions. The epibiotic bacterium was identified as Kocuria flava based on 16S rRNA gene sequencing. The EPS was further analysed using Fourier transform infrared (FT-IR), nuclear magnetic resonance (NMR) and X-ray diffraction (XRD) to understand the biochemical composition. NMR analysis revealed the presence of polysaccharides, proteins, acetyl amine and succinyl groups. Scanning electron microscope analysis indicated that the EPS consisted of aggregated and irregular sphere-shaped particles.

细胞外聚合物 (EPS) 存在于微生物的外部，在附着和生物膜形成中起重要作用。这些聚合物具有抗菌和防污活性。在这项研究中，评估了由与巨藻Ulva lactuca相关的附生细菌产生的 EPS对污垢细菌和藤壶幼虫的防污活性。结果表明，从附生细菌中分离的 EPS 抑制了细菌的生物膜形成，但没有太多的抗菌活性。此外，EPS 减少了藤壶幼虫在实验室条件下在硬质基质上的沉降。附生细菌被鉴定为Kocuria flava基于 16S rRNA 基因测序。使用傅里叶变换红外 (FT-IR)、核磁共振 (NMR) 和 X 射线衍射 (XRD) 进一步分析 EPS，以了解生化成分。核磁共振分析表明存在多糖、蛋白质、乙酰胺和琥珀酰基。扫描电镜分析表明EPS由聚集的不规则球形颗粒组成。