Degradation of cellulosic biomass and its subsequent utilization for the production of chemical feedstocks. Progress report, June 1, 1977--August 31, 1977

Technical Report · Thu Sep 01 00:00:00 EDT 1977

DOI:https://doi.org/10.2172/5266770· OSTI ID:5266770

Wang, D. I.C.; Cooney, C. L.; Demain, A. L.; Gomez, R. F.; Sinskey, A. J.

Studies on the microbial degradation of cellulose biomass continues to be centered around Clostridium thermocellum. The effect of surfactants on growth and cellulase production by C. thermocellum was investigated. The effect of pH on growth and reducing sugar accumulation rate of Clostridium thermocellum on solka floc was evaluated. Activity of extracellular cellulase of Clostridium thermocellum ATCC 27405 was examined using TNP--CMC and Avicel as substrates. The pH optima are 5 and 4.5, respectively. Hydrolysis of either substrate is not inhibited by cellobiose, xylose, or glucose. The enzyme appears to be quite stable under reaction conditions at 60/sup 0/C. Thus far, regulation studies indicate that CMCase formation is not repressed by cellobiose. The search for plasmids in C. thermocellum was continued. The presence of plasmids was confirmed by cesium chloride ethidium bromide gradient centrifugation and electron microscopy. Two plasmids were detected, one with an approximate molecular weight of 1 x 10/sup 6/ daltons. Studies on the fermentation of lactic acid to propionic acid showed the pathway in C. propionicum to be simpler than in M. elsdenii and hence more amenable to manipulation for acrylate production. Using Lactobacillius delbrueckii, it was possible to convert glucose, cellobiose, and cellulose hydrolysates to lactic acid rapidly and quantitatively. Fermentations of C. acetobutylicum growing in soluble media were performed. Detailed studies of Clostridium thermoaceticum have shown that pH is the primary limiting factor in the production of acetic acid. pH-controlled fermentations indicated accumulations of over 30 gm/l of acetic acid.

• Research Organization: Massachusetts Inst. of Tech., Cambridge (USA). Dept. of Nutrition and Food Science
• DOE Contract Number: EG-77-S-02-4198
• OSTI ID: 5266770
• Report Number(s): COO/4198-3
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
ACETIC ACID
BIOSYNTHESIS
ACETONE
BUTANOLS
CELLULOSE
BIODEGRADATION
ENZYMATIC HYDROLYSIS
FERMENTATION
CHEMICAL FEEDSTOCKS
PRODUCTION
LACTIC ACID
PROPIONIC ACID
OXIDATION
SACCHARIDES
ACRYLIC ACID
AEROBIC DIGESTION
ANAEROBIC DIGESTION
BACTERIA
CELLOBIOSE
CELLULASES
CENTRIFUGATION
CLOSTRIDIUM
GLUCOSE
PH VALUE
PLASMIDS
RESEARCH PROGRAMS
SURFACTANTS
XYLOSE
ALCOHOLS
ALDEHYDES
BIOCONVERSION
CARBOHYDRATES
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CHEMICAL REACTIONS
DECOMPOSITION
DIGESTION
DISACCHARIDES
ENZYMES
HEXOSES
HYDROLASES
HYDROLYSIS
HYDROXY ACIDS
HYDROXY COMPOUNDS
KETONES
LYSIS
MANAGEMENT
MICROORGANISMS
MONOCARBOXYLIC ACIDS
MONOSACCHARIDES
OLIGOSACCHARIDES
ORGANIC ACIDS
ORGANIC COMPOUNDS
PENTOSES
POLYSACCHARIDES
PROCESSING
SEPARATION PROCESSES
SOLVOLYSIS
SYNTHESIS
WASTE MANAGEMENT
WASTE PROCESSING
140504* - Solar Energy Conversion- Biomass Production & Conversion- (-1989)