Physiology of dark fermentative growth of Rhodopseudomonas capsulata

Journal Article · Sun Jun 01 00:00:00 EDT 1980 · J. Bacteriol.; (United States)

OSTI ID:5464530

Madigan, M T; Cox, J C; Gest, H

The photosynthetic bacterium Rhodopseudomonas capsulata can grow under anaerobic conditions with light as the energy source or, alternatively, in darkness with D-fructose or certain other sugars as the sole source of carbon and energy. Growth in the latter mode requires an ''accessory oxidant'' such as trimethylamine-N-oxide, and the resulting cells contain the photosynthetic pigments characteristic of R. capsulata (associated with intracytoplasmic membranes) and substantial deposits of poly-beta-hydroxybutyrate. In dark anaerobic batch cultures in fructose plus trimethylamine-N-oxide medium, trimethylamine formatin parallels growth, and typical fermentation products accumulate, namely, CO2 and formic, acetic, and lactic acids. These products are also found in dark anaerobic continuous cultures of R. capsulata; acetic acid and CO2 predominate when fructose is limiting, whereas formic and lactic acids are observed at elevated concentrations when trimethylamine-N-oxide is the limiting nutrient. Evidence is presented to support the conclusions that ATP generation during anaerobic dark growth of R. capsulata on fructose plus trimethylamine-N-oxide occurs by substrate level phosphorylations associated with classical glycolysis and pyruvate dissimilation, and that the required accessory oxidant functions as an electron sink to permit the management of fermentative redox balance, rather than as a terminal electron acceptor necessary for electron transport-driven phosphorylation.

• Research Organization: Indiana Univ., Bloomington
• OSTI ID: 5464530
• Journal Information: J. Bacteriol.; (United States), Vol. 142:3
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
59 BASIC BIOLOGICAL SCIENCES
METHYLAMINE
METABOLISM
NITROGEN OXIDES
PHOTOSYNTHETIC BACTERIA
GROWTH
BIOMIMETIC PROCESSES
CARBON DIOXIDE
CELL CULTURES
FERMENTATION
FRUCTOSE
OXIDIZERS
REDOX REACTIONS
RESPONSE MODIFYING FACTORS
AMINES
BIOCONVERSION
CARBOHYDRATES
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
HEXOSES
KETONES
MONOSACCHARIDES
NITROGEN COMPOUNDS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
SACCHARIDES
140505* - Solar Energy Conversion- Photochemical
Photobiological
& Thermochemical Conversion- (1980-)
550500 - Metabolism