Enzymatic and metabolic activities of four anaerobic sludges and their impact on methane production from ensiled sorghum forage.
Biochemical methane potential (BMP) tests were run on ensiled sorghum forage using four inocula (urban, agricultural, mixture of agricultural and urban, granular) and differences on their metabolic and enzymatic activities were also discussed. Results indicate that no significant differences were observed in terms of BMP values (258±14NmLCH4g(-1)VS) with a slightly higher value when agricultural sludge was used as inoculum. Significant differences can be observed among different inocula, in terms of methane production rate. In particular the fastest biomethanization occurred when using the urban sludge (hydrolytic kinetic constant kh=0.146d(-1)) while the slowest one was obtained from the agricultural sludge (kh=0.049d(-1)). Interestingly, positive correlations between the overall enzymatic activities and methane production rates were observed for all sludges, showing that a high enzymatic activity may favour the hydrolysis of complex substrate and accelerate the methanization process of sorghum.
Politecnico di Milano, DICA, Environmental Section, Piazza L. da Vinci, 32, 20133 Milano, Italy. Electronic address: cecilia.sambusiti@mail.polimi.it.
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Sambusiti
Università degli Studi di Milano, DEFENS, Section of Food Microbiology and Bioprocessing, via G. Celoria 2, 20133 Milano, Italy. Electronic address: manuela.rollini@unimi.it.
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Rollini
Politecnico di Milano, DICA, Environmental Section, Piazza L. da Vinci, 32, 20133 Milano, Italy. Electronic address: elena.ficara@polimi.it.
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Ficara
Università degli Studi di Milano, DEFENS, Section of Food Microbiology and Bioprocessing, via G. Celoria 2, 20133 Milano, Italy. Electronic address: alida.musatti@unimi.it.
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Musatti
Università degli Studi di Milano, DEFENS, Section of Food Microbiology and Bioprocessing, via G. Celoria 2, 20133 Milano, Italy. Electronic address: matilde.manzoni@unimi.it.
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Manzoni
Politecnico di Milano, DICA, Environmental Section, Piazza L. da Vinci, 32, 20133 Milano, Italy. Electronic address: francesca.malpei@polimi.it.
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Malpei
D056804:Biofuels; D019149:Bioreactors; D002851:Chromatography, High Pressure Liquid; D007700:Kinetics; D008031:Lignin / Q000032:analysis / Q000378:metabolism*; D008697:Methane / Q000096:biosynthesis*; D008954:Models, Biological; D012722:Sewage / Q000382:microbiology*; D045868:Sorghum / Q000378:metabolism*; D014995:Xylosidases / Q000378:metabolism*
D056804:Biofuels; D012722:Sewage; C036909:lignocellulose; D008031:Lignin; D014995:Xylosidases; D008697:Methane
Enzymes; Lignocellulosic biomass; Metabolic activity; Methane; Sludge