Abstract

The effect of humic acids on the formation of multispecies biofilms on the surface of high-pressure polyethylene and on the initial stages of its biocorrosion has been studied. The ability to form biofilms on the polyethylene surface and the initial stages of its biodegradation have been analyzed for two bacterial communities (binary and multispecies) isolated from the surface of polyethylene incubated in the topsoil (0–5-cm layer) in Myanmar during 180 days. Polyethylene samples were transported under sterile conditions to a laboratory (Moscow) and placed in vials with liquid medium (LB diluted 50 times by mineral medium M9 and with 0.1% C₁₁–C₁₆ paraffin solution added as an additional carbon source). Cultures were then disseminated to obtain individual colonies. Humic acids were extracted by alkaline extraction from the upper horizons of ferrallitic soil, in which the polyethylene sample was incubated (Myanmar), and from typical chernozem sampled in Lipetsk oblast (Orthic Acrisol and Haplic Chernozem according to the World Reference Base for Soil Resources, 2014). Humic acids were extracted from humate fertilizer Fleksom based on lowland peat. We assessed the formation of biofilms on the polyethylene surface by staining with crystal violet and changes in the polyethylene surface after the removal of biofilms by densitometric method. The stimulating effect of humic acids of a wide concentration range on the biofilm growth on the polyethylene surface and at the initial stage of its biodegradation has been revealed for the first time. The methodological approaches and the results obtained supplement the information on polyethylene biodegradation and can be applied in biotechnologies.

中文翻译：

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腐殖酸对聚乙烯表面生物膜形成及其土壤细菌降解的影响

摘要

研究了腐殖酸对高压聚乙烯表面形成多物种生物膜及其生物腐蚀初期的影响。对在 180 年期间在缅甸表土（0-5 厘米层）中培养的聚乙烯表面分离的两个细菌群落（二元和多菌种）在聚乙烯表面形成生物膜的能力及其生物降解的初始阶段进行了分析天。聚乙烯样品在无菌条件下运送到实验室（莫斯科），并放入装有液体培养基（LB 用矿物培养基 M9 稀释 50 倍，含 0.1% C ₁₁ –C _{16 ）的小瓶中}作为附加碳源添加的石蜡溶液）。然后传播培养物以获得单个菌落。腐殖酸是通过碱性萃取法从铁质土壤的上层土壤中提取的，聚乙烯样品在该土壤中进行了培养（缅甸），以及从利佩茨克州采样的典型黑钙土（根据世界土壤资源参考基地的 Orthic Acrisol 和 Haplic Chernozem， 2014）。腐植酸是从基于低地泥炭的腐植酸盐肥料 Fleksom 中提取的。我们通过用结晶紫染色评估了聚乙烯表面上生物膜的形成，以及通过光密度法去除生物膜后聚乙烯表面的变化。首次揭示了宽浓度范围的腐植酸对聚乙烯表面生物膜生长及其生物降解初期的刺激作用。方法学方法和获得的结果补充了聚乙烯生物降解的信息，可应用于生物技术。