土壤矿物介导下2种母质发育水稻土中多物种生物膜的形成

Formation of multi-species biofilms in paddy soils developed from two parent materials mediated by soil minerals

摘要:

【目的】探究土壤矿物介导下，不同母质发育的水稻土中多物种生物膜的形成过程，旨在为揭示土壤组分与多物种生物膜之间的互作机制提供科学依据。【方法】分别提取红黄泥田和酸紫泥田中的多物种生物膜作为研究对象，选取高岭石和针铁矿作为矿物相介质，借助现代生物显微技术、高通量测序技术和红外光谱等仪器，对矿物介导下的生物膜形成过程、结构变化以及膜内细菌群落结构的组成等进行深入研究。【结果】基于16S rRNA基因的高通量测序结果显示，2种母质发育水稻土中多物种生物膜内的菌群主要由绿弯菌门(Chloroflexi)、酸杆菌门(Acidobacteria)、变形菌门(Proteobacteria)、硝化螺旋菌门(Nitrospirae)和脱硫菌门(Desulfobacterota)构成。与未添加矿物体系(对照)相比，针铁矿和高岭石均显著抑制了以绿弯菌门为主导的酸紫泥田水稻土中多物种生物膜的形成，其生物膜生物量分别下降了18.38%和17.30%；而在以酸杆菌门占主导的红黄泥田体系中，针铁矿和高岭石从不同程度上促进了多物种生物膜的形成，且以高岭石体系促进效果更为显著，其生物膜厚度明显增加，膜内多糖分泌提高了7.69%，生物膜生物量同比增加18.99%。【结论】高岭石刺激细菌分泌产生了更多的胞外物质，并促进了红黄泥田中多物种生物膜的形成，而对酸紫泥田中多物种生物膜的形成具有抑制作用。针铁矿对酸紫泥田多物种生物膜的形成则表现出显著的抑制效应；相比高岭石体系，针铁矿的加入也更易导致细胞失活。本研究进一步揭示了土壤组分与多物种生物膜的互作机制，为推动土壤健康的可持续发展提供了科学的理论依据。

Abstract:

[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.