Composting of food waste subjected to hydrothermal pretreatment and inoculated with Paecilomyces sp. FA13

• Hydrothermal pretreatment was applied to food waste.
• Furan compounds were produced through hydrothermal pretreatment.
• Furan compounds inhibited microbial activities of composting.
• Isolated Paecilomyces sp. FA13 can degrade furan compounds.
• The FA13 used as an inoculum accelerated the composting by activating bacteria.

Food waste collected from restaurants, convenience stores, and food-processing factories was mixed with sawdust and subjected to hydrothermal pretreatment at 180 °C for 30 min to prepare compost raw material. Furan compounds such as 5-HMF (5-hydroxymethyl furfural) and furfural were produced at concentration levels of approximately 8 and 0.5 mg/g-ds, respectively, through hydrothermal pretreatment. The furan compounds inhibited the activity of composting microorganisms, thus delaying the start of organic matter degradation during composting. A newly identified fungus, Paecilomyces sp. FA13, which possesses the ability to degrade furan compounds, was isolated and used as an inoculum for the composting of the raw material prepared by hydrothermal pretreatment. By inoculating the FA13 into the compost raw material at 105 CFU/g-ds, the degradation of furan compounds was accelerated. As a result, bacterial activity, which contributed to composting, was enhanced, significantly promoting the start of vigorous degradation of organic materials.