Yeasts with potential to be used as microbial inoculants for sustainable agriculture in future.

Sustainability in agricultural production has emerged as one of the most significant concerns in the 21st Century, which recommends use of less chemical inputs having adverse effects on soil health and environment. The sustainability in the crop production system can be achieved by using beneficial soil microorganisms as microbial inoculants. A large number of studies have been carried out on bacteria and multicellular fungi which are used currently as microbial inoculants in sustainable agriculture. Yeasts, which are unicellular fungi are traditionally used for producing beverages and foods like wine, bread, beer, and fermented foods. Recent studies brought out that yeasts promote plant growth, suggesting their emerging role as bioinoculants in sustainable agriculture. They can directly improve plant growth by increasing the supply of macro and micro nutrients and also producing phytohormones. Some yeasts also suppress the activity of plant pathogens and insect pests, and degrade pesticides in soil. A few studies have also reported that yeast inoculation improved physical (aggregation, aeration and moisture retention), chemical (pH, soil organic carbon, soil labile carbon, soil protein index) and biological (microbial biomass carbon, dehydrogenase activity) properties of soil. The literature on the potential of using yeast as microbial inoculants under field conditions is limited. More investigations are needed so that yeasts can emerge as microbial inoculants for improving crop productivity in the coming years. In this review we have proposed a few perspectives and action points to be taken in future to harness the potential of yeasts in sustainable agriculture.