Biological Pretreatment of Chicken Feather and Biogas Production from Total Broth

• Published in: Applied biochemistry and biotechnology 2016-12, Vol.180 (7), p.1401-1415
• Main Authors: Patinvoh, Regina J., Feuk-Lagerstedt, Elisabeth, Lundin, Magnus, Sárvári Horváth, Ilona, Taherzadeh, Mohammad J.
• Format: Article
• Language: English
• Subjects: Anaerobic digestion; Anaerobiosis; Analysis of Variance; Animal feathers; Animals; Bacillus; bacillus substilis strain; Bacteria; bacteria granules; Biochemistry; Biodegradation, Environmental; Biofuels - supply & distribution; Biogas; biogas production; Biotechnology; Biotechnology - methods; Chemistry; Chemistry and Materials Science; chicken feather; Chickens; Feathers - metabolism; hydrolysate; Hydrolysis; keratinase; mesophilic; Methane; Methane - biosynthesis; Peptide Hydrolases - metabolism; pretreatment; Raw materials; Resource Recovery; Resursåtervinning; Sludge; Solubility; Substrate Specificity; total broth
• ISSN: 0273-2289; 1559-0291; 1559-0291
• DOI: 10.1007/s12010-016-2175-8

Chicken feathers are available in large quantities around the world causing environmental challenges. The feathers are composed of keratin that is a recalcitrant protein and is hard to degrade. In this work, chicken feathers were aerobically pretreated for 2–8 days at total solid concentrations of 5, 10, and 20 % by Bacillus sp. C 4 , a bacterium that produces both α- and β-keratinases. Then, the liquid fraction (feather hydrolysate) as well as the total broth (liquid and solid fraction of pretreated feathers) was used as substrates for biogas production using anaerobic sludge or bacteria granules as inoculum. The biological pretreatment of feather waste was productive; about 75 % of feather was converted to soluble crude protein after 8 days of degradation at initial feather concentration of 5 %. Bacteria granules performed better during anaerobic digestion of untreated feathers, resulting in approximately two times more methane yield (i.e., 199 mlCH 4 /gVS compared to 105 mlCH 4 /gVS when sludge was used). Pretreatment improved methane yield by 292 and 105 % when sludge and granules were used on the hydrolysate. Bacteria granules worked effectively on the total broth, yielded 445 mlCH 4 /gVS methane, which is 124 % more than that obtained with the same type of inoculum from untreated feather.