Nature has well knit system of biodiversity. Microbes that thrive on dead organic matter and decompose it to its elements are a sort of sanitary inspectors of nature. Dead animals, plants, organic food remains are acted upon by such microbes. Due to their differential activity on organic food they have also been tamed to undertake selective degradation, up gradation modification of food items turning them into cheese, vinegar, alcohol etc. Other microbes are helpful in nitrogen fixation, phosphorus solubilization, and mineralization of elements. Nitrogen fixing bacteria in symbiotic and non symbiotic mode are important for agriculture. Pathogenic bacteria like Agrobacterium spp have been tamed for genetic engineering studies. Strangely the plant pathogenic bacteria are mostly gram negative and don’t infect the humans ( exceptions apart) and most of the human pathogens are gram positive . I am not microbiologist but point I want to make is microbes make large part of biodiversity or a support system for different cycles which allow the recycling process in nature. I doubt if all the microbes are identified and documented globally. Recently some microbes from tropical climate have been identified to provide salinity resistance to the plants. Unlike plants which derive their energy from light source, the bacteria (leave aside photosynthetic bacteria) derive their energy from chemical degradation process. Instead of Oxygen as in plants the terminal electron acceptor is a compound of organic nature i.e. a process leading to fermentation, or inorganic compound like sulphur leading to anaerobic respiration,. The reducing agents in photosynthetic organisms are derived from photochemical process of carbon reduction but bacteria generate them by process of reduction of organic or inorganic substances. Do you find it interesting? It’s very complex biochemistry but worth following . Plants have elaborate root system which is dynamic rhizosphere and rhizoplane concept as roots go deeper and deeper in soil the microclimate and micro flora keep on changing to mutual benefit. Live and let live is the motto of plants and microbes. When will the humans follow it globally?