Hydrogen metabolism and energy conservation in methanogenic bacteria

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:7171070

Woo, S B

The investigation deals with the effect of pyrophosphate on methanogenesis, function of pyruvate, orthophosphate dikinase, purification and characterization of the two types of hydrogenase and finally localization of hydrogenases in methanogenic bacteria. Pyrophosphate was found to stimulate methanogenesis of enrichment cultures in medium of fresh water mud as well as some pure methanogenic cultures. Pyruvate, orthophosphate dikinase was purified and characterized from Methanosarcina MST-Al. It reversibly converts phosphoenolpyruvate, AMP, and pyrophosphate into pyruvate, ATP and orthophosphate. In the presence of PP{sub i} this enzyme functions as an apparent ATP generating system in cell free extracts of Methanosarcina barkeri (DSM 800). Hydrogenase of methanogenic bacteria can be distinguished into three types according to their metal content, deuterium-proton exchange reaction, amino terminal amino acid sequence, inhibition by CO, NO and sodium nitrite, immunological cross-reactivity, and EPR properties. A 660-KDa a hydrogenase was purified from Methanococcus voltae (DSM 1537). The enzyme consists of three non-identical subunits and catalyzes the oxidation of H{sub 2} with cofactor F{sub 420} as well as the artificial electron carriers methylviologen and benzyl viologen. It is a (NiFeSe) hydrogenase. On the other hand, two hydrogenases were purified from Methanosarcina MST-Al (DSM 2905), a thermophilic methylotrophic methanogen. A 750 KDa (NiFe) hydrogenase with three non-identical subunits was F{sub 420}-reducing, while a 173 KDa Ni-containing hydrogenase with two unequal subunits was MV-reducing.

• Research Organization: Georgia Univ., Athens, GA (USA)
• OSTI ID: 7171070
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
090900* -- Biomass Fuels-- Processing-- (1990-)
550700 -- Microbiology
59 BASIC BIOLOGICAL SCIENCES
ALKALI METAL COMPOUNDS
BACTERIA
BIOCHEMICAL REACTION KINETICS
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CARBOXYLIC ACIDS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTIONS
CLASSIFICATION
ELECTRON SPIN RESONANCE
ELEMENTS
ENERGY CONSERVATION
ENZYMES
ESTERS
GROWTH
HYDROGEN
HYDROGENASES
INHIBITION
KETO ACIDS
KINETICS
MAGNETIC RESONANCE
MEASURING METHODS
METABOLISM
METHANOGENIC BACTERIA
MICROORGANISMS
NITRIC OXIDE
NITRITES
NITROGEN COMPOUNDS
NITROGEN OXIDES
NONMETALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXIDATION
OXIDES
OXIDOREDUCTASES
OXYGEN COMPOUNDS
PHOSPHORUS COMPOUNDS
PYROPHOSPHATES
PYRUVIC ACID
REACTION KINETICS
RESONANCE
SODIUM COMPOUNDS