title: Kinetics of biomethanation of solid tannery waste and the concept of interactive metabolic control.
abstract: Anaerobic digestion of calf skin collagenous waste was optimized for a batch process based on accelerated maximal methane yield per gram of input volatile solid. A kinetic analysis with respect to changes in the levels of volatile solid, collagen, amino sugars, amino acids, hydroxyproline, ammonium ions, and volatile fatty acid were followed for a period of 80 d. Distinct metabolic phases included an initial high rate collagenolysis for 4d, with 50% degradation and was followed by an acidogenic phase between 4-12 d with volatile fatty acids levels increasing to 215 mmol/L. Subsequently methanogenesis ensued and was maximal between 12-24 d when volatile fatty acids attained steady state levels. During the period of 80 d, the overall decrease in volatile solid level was 65%, whereas the collagen level declined by 85% with 0.45 L of methane yield/g of volatile solid degraded. Based on the levels of various metabolites detected, the concept of interactive metabolic control earlier proposed has been validated.
authors.affiliation: Department of Chemistry, Indian Institute of Technology, Madras.
authors.forename: K
authors.initials: K
authors.lastname: Lalitha
authors.forename: K R
authors.initials: KR
authors.lastname: Swaminathan
authors.forename: R P
authors.initials: RP
authors.lastname: Bai
mesh_terms: D000693:Anaerobiosis; D000818:Animals; D001673:Biodegradation, Environmental; D002417:Cattle; D003094:Collagen / Q000378:metabolism; D004787:Environmental Pollution / Q000517:prevention & control; D007887:Fabaceae / Q000378:metabolism; D007220:Industrial Waste; D007700:Kinetics; D008697:Methane / Q000378:metabolism*; D010946:Plants, Medicinal; D012867:Skin / Q000378:metabolism; D013633:Tanning
chemical_list: D007220:Industrial Waste; D003094:Collagen; D008697:Methane