Biological treatment of chicken feather waste for improved biogas production  

作　　者：Gergely Forgcs Saeid Alinezhad Amir Mirabdollah Elisabeth Feuk-Lagerstedt Ilona Srvri Horvth 

机构地区：[1]School of Engineering,University of Bors,501 90 Bors,Sweden [2]Department of Chemical and Biological Engineering,Chalmers University of Technology,412 96 Gteborg,Sweden [3]School of Engineering,University of Boras,501 90 Bors,Sweden

出　　处：《Journal of Environmental Sciences》2011年第10期1747-1753,共7页环境科学学报（英文版）

基　　金：supported by the Swedish Excellence Center Waste Refinery

摘　　要：A two-stage system was developed which combines the biological degradation of keratin-rich waste with the production of biogas. Chicken feather waste was treated biologically with a recombinant Bacillus megaterium strain showing keratinase activity prior to biogas production. Chopped, autoclaved chicken feathers （4%, W/V） were completely degraded, resulting in a yellowish fermentation broth with a level of 0.51 mg/mL soluble proteins after 8 days of cultivation of the recombinant strain. During the subsequent anaerobic batch digestion experiments, methane production of 0.35 Nm3/kg dry feathers （i.e., 0.4 Nm3/kg volatile solids of feathers）, corresponding to 80% of the theoretical value on proteins, was achieved from the feather hydrolyzates, independently of the pre- hydrolysis time period of 1, 2 or 8 days. Cultivation with a native keratinase producing strain, Bacillus licheniformis resulted in only 0.25 mg/mL soluble proteins in the feather hydrolyzate, which then was digested achieving a maximum accumulated methane production of 0.31 Nm3/kg dry feathers. Feather hydrolyzates treated with the wild type B. megaterium produced 0.21 Nm3 CH4/kg dry feathers as maximum yield.A two-stage system was developed which combines the biological degradation of keratin-rich waste with the production of biogas. Chicken feather waste was treated biologically with a recombinant Bacillus megaterium strain showing keratinase activity prior to biogas production. Chopped, autoclaved chicken feathers （4%, W/V） were completely degraded, resulting in a yellowish fermentation broth with a level of 0.51 mg/mL soluble proteins after 8 days of cultivation of the recombinant strain. During the subsequent anaerobic batch digestion experiments, methane production of 0.35 Nm3/kg dry feathers （i.e., 0.4 Nm3/kg volatile solids of feathers）, corresponding to 80% of the theoretical value on proteins, was achieved from the feather hydrolyzates, independently of the pre- hydrolysis time period of 1, 2 or 8 days. Cultivation with a native keratinase producing strain, Bacillus licheniformis resulted in only 0.25 mg/mL soluble proteins in the feather hydrolyzate, which then was digested achieving a maximum accumulated methane production of 0.31 Nm3/kg dry feathers. Feather hydrolyzates treated with the wild type B. megaterium produced 0.21 Nm3 CH4/kg dry feathers as maximum yield.

关 键 词：anaerobic digestion feather waste keratinase  Bacillus licheniformis Bacillus megaterium gene expression 

分 类 号：X705[环境科学与工程—环境工程]