Abstract
Human hair remaining in sewage sludge compost leads to a deterioration in the quality of the compost. We isolated and characterized the thermophilic microorganisms that decomposed human hair to improve the quality of sewage sludge compost products. The strains were isolated on agar plates after the enrichment culture in hair liquid medium at 50℃ for more than 30 days. The concentrations of amino acids released from keratin or hair were measured to determine the ability to decompose keratin or hair and the extent of hair damage was observed microscopically. We obtained twelve strains which had more efficient hair-decomposing activities at 50℃ than the reported ones. Strain K35 had the highest rate of amino acid production from hair of 77.4mg/L/day. In addition, the effects of strain mixtures and hair disruption on bacterial decomposition are discussed.
