MICROBIAL COMMUNITY DYNAMICS OF COMPOST MIXTURES AFTER APPLICATION OF MICROBIOLOGICAL ADDITIVE

The present study aimed to analyze the dynamics of the microbial community of compost mixtures after application of a microbiological additive. Three series of compost mixtures are available with two variants each: one control and one with a microbiological additive. Quadruple sampling was performed. Main groups of aerobic microorganisms were analyzed: non-spore-forming and spore-forming bacteria, actinomycetes and molds. The total microflora of aerobic and anaerobic microorganisms was determined, and a predominance of aerobes was reported. Temperature, pH and humidity were analyzed. All variants showed an initial slight increase in microbial abundance on day 8 and a subsequent smooth steady decline as the composting process progressed. Non-sporing bacteria predominated in all mixtures. Spore-forming bacteria are least involved. Only one variant with the supplement had higher biogenicity than the control. There is no evidence that the applied supplement has a major positive effect on the microbial biota. Microbial community structures were not affected by the introduction of the microbiological additive. We consider the influence of input material and the optimal C: N ratio as the main determinant of microbial abundance.