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

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

We bred a microbial community capable of degrading rice straw with high efficiency. The microbial community degraded more than 60% of rice straw within 4 days at 50 °C. The high stability of the community's degradation ability was demonstrated by its tolerance of being subcultured several times in medium with/without cellulosic material, being heated to 95 °C, and freezing at –80 °C. The community degraded both nonsterilized and sterilized substrate; and its degradation ability was not affected by pH changes in the medium (initial pH 5–9). PCR-denaturing gradient gel electrophoresis (DGGE) analyses based on 16S rDNA fragments showed that the community structure remained constant after multiple subcultures extending over 2 years. DNA sequence analyses of DGGE bands indicated the coexistence of both aerobic and anaerobic bacteria in the community.

Construction of a stable microbial community with high cellulose-degradation ability

Succession of bacterial and fungal communities during a traditional pot fermentation of rice vinegar assessed by PCR-mediated denaturing gradient gel electrophoresis.

Molecular analysis of bacterial community succession during prolonged compost curing

PCR-DGGE analysis followed by sequencing of 16S rDNA was applied to reveal the succession and the phylogenetic composition of the bacterial communities responsible for the composting process of rice straw (RS). RS under the composting process exhibited more complex DGGE band patterns with more numerous bands and more diversification in intensity than the initial RS materials. The DGGE patterns of the bacterial communities in the initial RS materials and RS under the composting process were statistically divided into four groups, namely those characterizing the communities associated with the pre-composting stage, and thermophilic, middle, and curing stages of the compost, which corresponded exactly to the same grouping obtained from the PLFA pattern analysis for the same samples (Cahyani et al. 2002: Soil Sci. Plant Nutr., 48, 735-743). Different bacterial members characterized the respective stages as follows: a-Proteobacteria for the initial RS materials, thermophilic Bacillus spp. and actinomy...

https://www.tandfonline.com/doi/pdf/10.1080/00380768.2003.10410052

Masaru Hazaka

Papers

Denaturing gradient gel electrophoresis analyses of microbial community from field-scale composter.

Isolation and characterization of predominant microorganisms during decomposition of waste materials in a field-scale composter