Metabolism, autotrophic

Erostl JM, Seifritz C, Drake HL. 1996. Effect of nitrate on the autotrophic metabolism of the acetogens Clostridium thermoautotrophicum and Clostridium thermoaceticum. J Bacteriol 178 4597-603. 

The theory is based on the autotrophic metabolism of low-molecular-weight constituents in an environment of iron sulfide and hot vents. Figure 2.4 gives an illustration of one reaction pathway. It is worthwhile to consider that the metabolism is a surface metabolism, namely with a two-dimensional order, based on negatively charged constituents on a positively charged mineral surface. Actually Wachtershauser sees this as an interesting part of a broader philosophical view (Huber and Wachtershauser, 1997). 

Nitrosomonas europaea Autotroph Metabolic labeling Metabolic pathway analysis (197)... 

Figure 1 The distribution of autotrophic metabolic pathways among taxa within the three major domains of life (as inferred from ribosomal RNA sequences (Pace, 1997)). Specific metabolic pathways are indicated.

Theoretical studies [21, 22] have postulated that emergence of autotrophic metabolic pathways, such as reductive citric acid cycle (RCC) may have occurred under high P-T hydrothermal conditions analogous to deep marine hydrothermal vents. Earlier experimental work established that citric acid decomposition under hydrothermal conditions leads to the... 

Volume 29. Comparative biochemistry, molecular evolution I. Comparative biochemistry, (a) Basic concepts, (b) Autotrophic metabolism, (c) Chemical needs in heterotrophs. (rf) Biochemical cycles in the biosphere, (e) Biochemistry and taxonomy. II. Molecular evolution, (a) Molecular adaptations to the physical environment, (b) Molecular adaptations to the biological environment, (c) Heteromor-phic aspects of molecular evolution, (d) Evolution of biochemical systems, physiological radiations, (e) Biosynthesis and phylogeny. (/) Paleobiochemistry. (g) Chemical evolution and prebiological evolution. Subject index. 

Synthesis of the amino acids in the body of the vertebrates is limited to those that are not essential in the diet. The essential amino acids are the products of organisms with a more autotrophic metabolism, such as various plants and microorganisms. 

A less-common type of autotrophic metabolism, called chemosynthe-sis, is found in microbes living around deep-sea hydrothermal vents. These organisms obtain nutrients in the absence of sunlight by metabolizing nitrogen and sulfur compounds produced by geothermal activity beneath the oceans. 

Microalgae are able to get energy from different metabolisms (Richmond and Qian 2004). In autotrophic metabolism, in the presence of light, organisms are able to convert CO2 and water into biomass. Already heterotrophic systems are a different approach to microalgal biomass production with elimination of light requirement and CO2 absorption. 

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