Formation of multi-species biofilms in paddy soils developed from two parent materials mediated by soil minerals
[Objective]To explore the formation process of multi-species biofilms in paddy soils developed from different parent materials mediated by soil minerals,thus providing a scientific basis for revealing the interaction mechanisms between soil components and multi-species biofilms.[Methods]The multi-species biofilms were extracted from reddish clayey soil and acidic purple soil,and kaolinite and goethite were used as the mineral media.Modern biological microscopy,high-throughput sequencing,and infrared spectroscopy were employed to study the mineral-mediated formation process,structural changes,and bacterial community structure of the biofilm.[Results]Based on the high-throughput sequencing technology of 16S rRNA gene,the flora in the multi-species biofilms in the paddy soils developed from the two parent materials was dominated by Chloroflexi,Acidobacteria,Proteobacteria,Nitrospirae,and Desulfobacterota.Compared with the control without mineral addition,goethite and kaolinite significantly inhibited the formation of the multi-species biofilm dominated by Chloroflexi in the acidic purple soil,decreasing the biofilm biomass by 18.38%and 17.30%,respectively.In the reddish clayey soil dominated by Acidobacteria,goethite and kaolinite promoted the multi-species biofilm formation to varying degrees.Kaolinite demonstrated more significant promotion effect,increasing the biofilm thickness,the secretion of polysaccharides in the biofilm by 7.69%,and the biofilm biomass by 18.99%.[Conclusion]Kaolinite stimulated bacterial production of extracellular substances,promoted the multi-species biofilm formation in reddish clayey soil,and inhibited the multi-species biofilm formation in acidic purple soil.Goethite inhibited the multi-species biofilm formation in acidic purple soil.Compared with kaolinite,goethite is likely to cause cell inactivation.This study further revealed the interaction mechanism between soil components and multi-species biofilms,and the results provided a scientific theoretical basis for promoting the sustainable development of soil health.
soil mineralsmulti-species biofilmbacterial communitysoilparent material