Biofilm forming and heavy metal resistant marine bacterial strain Pseudomonas chengduensis PPSS-4 was isolated from the contaminated marine sediment of Paradip Port, Odisha, India. The strain showed biofilm formation up to 100 mg/L of multi-metal [Pb(II), Cr(VI), and Cd(II)] supplementation in the culture medium. Scanning electron microscopy (SEM) showed aggregation of rod-shaped cells in the extracellular polymeric substance (EPS) matrix of biofilm. Confocal laser scanning microscopy (CLSM) exhibited a higher nucleic acid to the α-polysaccharide ratio in the biofilm, and the observed thickness was ~21 µm. The metal uptake potential of biofilm culture was higher than planktonic culture both in single and multi-metal solutions. FESEM-EDS analysis revealed the sequestration of multi-metals by bacterial cells and biofilm-EPS. FTIR analysis of bacterial EPS further ensured the interaction of functional groups such as –OH, –NH, and P=O with the metal ions. The maximum removal of Pb, Cr, and Cd by the bacterial biomass was observed at 37°C within 4 h of contact time at pH 6, and 4% salinity for Pb and Cr, and 6% salinity for Cd. The present study revealed that the marine bacterium P. chengduensis PPSS-4 can remove multi-metals, and this bacterium could be efficiently utilized for the remediation of heavy metals in the contaminated environment.

从印度奥里萨邦帕拉迪普港受污染的海洋沉积物中分离出生物膜形成和重金属抗性海洋细菌菌株Pseudomonas chengduensis PPSS-4。该菌株在培养基中显示出高达 100 mg/L 的多金属 [Pb(II)、Cr(VI) 和 Cd(II)] 补充剂的生物膜形成。扫描电子显微镜 (SEM) 显示杆状细胞在生物膜的细胞外聚合物 (EPS) 基质中聚集。共聚焦激光扫描显微镜 (CLSM) 显示出比α更高的核酸-生物膜中的多糖比率，观察到的厚度为~21 µm。在单金属和多金属溶液中，生物膜培养的金属吸收潜力均高于浮游培养。FESEM-EDS 分析揭示了细菌细胞和生物膜-EPS 对多金属的螯合。细菌 EPS 的 FTIR 分析进一步确保了 -OH、-NH 和 P=O 等官能团与金属离子的相互作用。在 37°C 下，接触时间为 4 小时，pH 值为 6，铅和铬的盐度为 4%，镉的盐度为 6%，细菌生物质对 Pb、Cr 和 Cd 的最大去除率。目前的研究表明，海洋细菌P. chengduensis PPSS-4可以去除多种金属，这种细菌可以有效地用于污染环境中重金属的修复。