A survey of bacteria and fungi occurring during composting and self-heating processes

Abstract- Composting is a controlled self-heating, aerobic solid phase biodegradative process of organic materials. The process comprises mesophilic and thermophilic phases involving numerous microorganisms. In several successive steps, microbial communities degrade organic substrates into more stable, humified forms and inorganic products, gener-ating heat as a metabolic waste product. Due to the complexity of substrates and intermedi-ate products, microbial diversity and the succession of populations is a prerequisite to ensure complete biodegradation. Due to the dynamic process, both in time and space (microhabi-tats), which is reflected by constantly changing pH, humidity, oxygen partial pressure and temperature it is extremely difficult to detect, albeit isolate, all the microorganisms involved. Research on composts is also so difficult because the process can hardly be simulated in the laboratory since all major gas and temperature fluxes are to a large extent determined by the physical extension of the system. In this comprehensive survey of literature an inventory of the mesophilic and thermophilic bacteria, actinomycetes and fungi isolated during several phases of composting (including also self-heating organic materials) is presented.