Microbial biofilms and mitigation of loss of agro-biodiversity in degraded soils

Abstract

Modern agriculture has been one of the causes for biodiversity degradation. Conservation of the remaining biodiversity is of utmost importance and novel approaches and concepts should be tested to achieve this end. As a recent development in microbiology, fungal surface-attached bacterial communities or fungal-bacterial biofilms (FBBs) are being studied for various biotechnological applications with consequences in ecosystem functioning and biodiversity. The present study was conducted to investigate the effect of the introduced FBBs on restoration of reduced biodiversity in the soil of a degraded tea land. The soil was treated with a developed biofilm, its monocultures, the nutrient solution used for culturing the microbes, and sterilised distilled water in a pot experiment. After three months, the soils were evaluated for plant and culturable microbial species richness, microfaunal count, nitrogenase activity, and selected soil parameters. It was observed that the biofilm application resulted in a significantly higher plant species richness than the respective monocultures (p < 0.05). Further, culturable bacterial and fungal species richnesses, soil nitrogenase activity, organic carbon, and available ammonium and nitrate increased significantly with the biofilm application, compared with the application of the nutrient solution and distilled water (p < 0.05). Results of the present study indicated that inoculation of the developed microbial biofilms influences microbial and plant diversity and soil quality parameters positively. These observations indicate that the microbial biofilms developed in this study may have the potential to be developed as a novel biotechnological tool to mitigate biodiversity loss in agroecosystems and perhaps in natural ecosystems.