This study was aimed at studying the effect of heavy metals and arsenic on the survival and biofilm formation of some saprotrophic microorganisms: Bacillus megaterium var. phosphaticum, Bacillus mucilaginosus, Pectobacterium carotovorum, and Escherichia coli. As a source of heavy metals and arsenic, we used aqueous solutions of NaAsO₂, Cd(CH₃COO)₂, and Pb(NO₃)₂ (2.5, 25, 250 mg L⁻¹). The cultures in the liquid medium had different resistance to the toxicants under study: B. megaterium > B. mucilaginosus > P. carotovorum > E. coli. The toxicity of the tested solutions of heavy metals and arsenic for microorganisms can be arranged (decreasing toxicity) as follows: cadmium acetate > lead nitrate > sodium metaarsenite. These experiments revealed some regularities related to the mechanisms of toxic effect of As, Pb, and Cd solutions on the formation of biofilms of soil bacteria, changes in bacterial cellular forms, and their survival. Bacillus megaterium strain was the most resistant to high As concentrations and was able to influence the formation of highly structured colonies of bacterial cells with the honeycomb-like structure. The immobilization of heavy metals can be achieved due to their binding into strong compounds with the matrix substances of biofilms and polymeric organic compounds formed during the sporulation of rhizobacteria. It can increase the resistance of bacteria to high concentrations of heavy metals and arsenic. The results obtained can be of great practical importance in the development of biotechnologies related to soil bioremediation, in the field of nanotechnology, crop production, and medicine.

本研究旨在研究重金属和砷对一些腐生微生物的存活和生物膜形成的影响：巨大芽孢杆菌变种。磷酸盐、粘液芽孢杆菌、食果肉杆菌和大肠杆菌。作为重金属和砷的来源，我们使用了 NaAsO ₂、Cd(CH ₃ COO) ₂和 Pb(NO ₃ ) ₂（2.5、25、250 mg L ^-1）的水溶液。液体培养基中的培养物对所研究的毒物具有不同的抵抗力：巨大芽孢杆菌 >  B. mucilaginosus >  P. carotovorum  > 大肠杆菌。被测重金属和砷溶液对微生物的毒性排列（毒性递减）为：醋酸镉>硝酸铅>偏亚砷酸钠。这些实验揭示了与 As、Pb 和 Cd 溶液对土壤细菌生物膜形成、细菌细胞形态变化及其存活的毒性作用机制相关的一些规律。巨大芽孢杆菌菌株对高砷浓度的抵抗力最强，并且能够影响具有蜂窝状结构的细菌细胞高度结构化菌落的形成。由于它们与生物膜的基质物质和在根际细菌孢子形成过程中形成的聚合有机化合物结合成强化合物，因此可以实现重金属的固定化。它可以增加细菌对高浓度重金属和砷的抵抗力。所获得的结果对于开发与土壤生物修复相关的生物技术、纳米技术、作物生产和医学领域具有重要的实际意义。