Characterization of thermophilic fungal communities during the thermophilic stage of composting

PT. Great Giant Pineapple is one of the companies operating in the food industry. During its production process, the company generates a significant amount of waste, including fruit peels, pineapple cores, livestock manure, and other parts not used in the final product. Efforts to address this issue involve processing the waste into compost through a decomposition process involving microorganisms, including thermophilic fungi. Thermophilic fungi possess thermostable properties and play a crucial role in accelerating chemical reaction rates by releasing extracellular enzymes, thereby speeding up the composting process. This study aims to isolate and characterize thermophilic fungi in deep compost during the composting process at PT. Great Giant Pineapple. The methods used include sampling, homogenization, and serial dilution, isolation, purification, macroscopic, microscopic, and physiological characterization, and determination of enzymatic indices. The results of this study yielded four isolates indicated as thermophilic fungi. Macroscopic isolates Bio DK 1, Bio DK 2, and Bio DK 3 showed green colonies with white to grayish-white edges, smooth and thick in texture. Meanwhile, the Bio DK 4 isolate appears different with white-colored colonies and a thin, smooth, fibrous texture. Microscopic all isolates have hyphae, with Bio DK 1, 2, and 3 isolates having conidia, while the Bio DK 4 isolate has sporangia. In the enzyme activity test, Bio DK 1 showed the highest ability to produce cellulose enzymes with an enzymatic index of 7.52, while Bio DK 4 had the highest enzymatic index for protease enzymes at 3.05. In the ligninase enzyme activity test, all isolates were unable to degrade lignin.