抄録
In order to improve the quality of sewage sludge compost products, hair-decomposing bacteria were isolated and investigate their function on composting process, because much human hair remaining in sewage sludge compost causes deterioration in quality. The isolated strains on the agar plates served in hair and keratin liquid medium for measuring the generated amino acid concentration and observing the situation of hair decomposition microscopically. Three strains, including Bacillus sp.(No.5) and two actinomycetes (No.9 and No.10) were obtained as promising bacteria and their characteristics were examined through four experiments. From the results of time course experiments, No.10 got the highest rate of amino acid production of 1.834 (g/L·Eday) from keratin. The temperature experiments showed that in the hair liquid medium the peak of the rate of amino acid production was at 25°C and the minimum was at 50°C. The falling rate of No.5 by the effect of rising temperature was smaller than other two. The coefficient dependent on temperature which was analogous to the activation energy in Arrhenius equation was introduced to evaluate the effect of temperature. In addition, the results of the mixture of experiments and the pretreatment experiments were discussed.
