Affiliation:
1. University of Forestry, Faculty of Forestry, Department of Silviculture
Abstract
The present study aimed to track the changes in microbial communities during home composting of biodegradable plastic products (PLA). 6 waste mixtures and controls were prepared, with C:N about 30, placed in containers. The amount of PLA compared to the compostable mixture is 1%. Different depositing methods were used - active composting and placing part of the material in biodegradable bags. Temperature, humidity, pH, C:N ratio were measured. The amounts of bacteria, actinomycetes, micromycetes were recorded during the individual phases of composting, including the initial mixing of the materials. The microbiological analyzes were performed using the counting plate method. The reading is done in colony forming units. Total microbial number (TMN) was calculated. The ratio of the microbial populations in the studied samples with PLA was compared with the dynamics of development of the microbial populations in the control samples. Samples with added PLA have a higher TMN. For samples placed in a biodegradable bag, the thermophilic phase occurs faster and the amounts of microorganisms are higher. In all tested variants, the controls gave lower values of TMN. Some of the biodegradable materials (cutlery) are still discernible at the end stage of the composting process. Standard dynamics were observed in changing the percentage participation of individual microbial groups during the different phases of composting, regardless of added PLA. PLAs stimulate the composting process.