Examination of thermophilic methane-producing digesters by analysis of bacterial lipids

Journal Article · Sun Dec 01 04:00:00 EST 1985 · Appl. Environ. Microbiol.; (United States)

OSTI ID:5366652

Henson, J M; Smith, P H; White, D C

Thermophilic methane-producing digesters were examined by the analysis of lipids to determine the microbial biomass, community structure, and nutritional status of the microbes within the digesters. The digesters received a daily feedstock of cattle feed and Bermuda grass, with some digesters receiving additional supplements of propionate, butyrate, or nitrate. Microbial biomass, measured as total extractable lipid phosphate, was decreased in slurries from digesters receiving continuous addition of the fermentation intermediates propionate or butyrate as compared with slurries from control digesters receiving the feedstock alone. In slurries from digesters that received continuous addition of nitrate, the microbial biomass was higher than in the slurries from control digesters. The control digesters had ca.2.5X10/sup 11/ bacteria per g (dry weight) as determined from total extractable lipid phosphate. Shifts in microbial community structure were observed by analysis of ester-linked phospholipid fatty acids. Statistical analysis of the patterns of phospholipid fatty acids indicated that the digesters receiving different supplements could be distinguished from the control digester and from each other. Poly-..beta..-hydroxybutyric acid, an indicator of metabolic stress, was detected in slurries from all the digesters. Slurries from the nitrate-amended digester had the highest concentration of poly-..beta..-hydroxybutyric acid, whereas slurries from the propionate-amended digester had the lowest concentration. These chemical analyses offer a quantitative means to correlate shifts in microbial biomass, community structure, and nutritional status in complex fermentation systems to the production of a specific end product.

• Research Organization: Univ. of Florida, Monticello; Florida State Univ., Tallahasse; Univ. of Florida, Gainesville
• OSTI ID: 5366652
• Journal Information: Appl. Environ. Microbiol.; (United States), Journal Name: Appl. Environ. Microbiol.; (United States) Vol. 50:6; ISSN AEMID
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
090122* -- Hydrocarbon Fuels-- Preparation from Wastes or Biomass-- (1976-1989)
140504 -- Solar Energy Conversion-- Biomass Production & Conversion-- (-1989)
ALKANES
BACTERIA
BIOMASS
BIOREACTORS
CHEMICAL ANALYSIS
CONTROL
ENERGY SOURCES
GAS ANALYSIS
HYDROCARBONS
LIPIDS
MATHEMATICS
METHANE
MICROORGANISMS
NUTRIENTS
ORGANIC COMPOUNDS
PROCESS CONTROL
PRODUCTION
RENEWABLE ENERGY SOURCES
STATISTICS
THERMOPHILIC CONDITIONS