Investigating the Role of Compost Microbiota for Improving Plant Health and Resistance to Stress

The necessity to feed an ever-growing global population has driven intensive agricultural practices over the past half-century, leading to significant soil deterioration and biodiversity loss. This environmental degradation poses serious threats to crop cultivation. Sustainable approaches are essential for preserving soil health and microbial communities in the soil. Certain bacteria form symbiotic relationships with plant roots, improving nutrient uptake, productivity, and resilience to stresses. Soil rich in microorganisms is more fertile due to these beneficial biochemical activities. Modern agricultural practices endanger soil biodiversity, influencing soil structure and plant productivity. Biofertilizers, like compost, offer a potential remedy. Compost, a product of controlled aerobic decomposition of organic materials, is rich in organic matter and nutrients. Its potential as a microbial inoculum for enriching the soil and fostering plant health needs further investigation. This work is part of a larger project aimed at understanding the role of compost microbiota in plant health. For this purpose, several approaches were used, including the isolation of potentially growth-promoting microorganisms from compost. In this work, growth kinetics was investigated to characterize the growth of these bacteria. In parallel, some of these were genetically transformed with fluorescent protein genes. In order to understand the effect of compost on plant stress response, a water stress experiment was also done with Solanum lycopersicum L. var. Micro-Tom plants, which provided insights into how the compost microbiota might help the plant cope with water stress, as the data collected might indicate. This tells us that compost and its microbiota have the potential to help plants because it contains microorganisms that can interact with them.