Microorganisms, Fungi, and Higher Plants

Biomining processes are used successfully on a commercial scale for the recovery of gold and other metals, and are based on the activity of obligate chemoautolithotrophic bacteria that use iron or sulfur as their energy source 

Plectonema terebrans, a species of filamentous marine cyanobacteria, accumulates gold in its sheath from an aqueous solution of AuCls. Sheaths are among the few stmctures likely to be preserved in some form in microfossils of ancient bacteria. In marine media, it is expected that AuCls (2.0 g Au/L) will formAuCl4, AuOJ, andAuClJ Biosorption of Au+, as AUCI4, by dried Pseudomonas strains of bacteria was inhibited by palladium, as Pd+, and possibly other metal ions. 

Metabolically active fungal cells of Aspergillus fumigatus and A. niger removed gold from cyanide leach liquor of a Brazilian gold extraction plant more efficiently than 

Except for crab exoskeletons, gold recovery from the medium by various species of living molluscs, crustaceans, and fishes is negligible. The maximum concentration of stable gold measured in tissues of living marine organisms was 38.0 xg/kg FW. 

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Most microorganisms, fungi and higher plants synthesise biotin from pimelic acid and alanine. Pimelic acid is a product of oxidative cleavage of higher fatty acids. The primary product of the biosynthesis is dethiobiotin (5-85), which reacts with methionine and gives biotin. Biotin is found as a prosthetic group... 

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