Bacterial degradation of arsenobetaine via dimethylarsinoylacetate

• Published in: Archives of microbiology Vol. 180; no. 2; pp. 142 - 150
• Main Authors: JENKINS, Richard O, RITCHIE, Alisdair W, EDMONDS, John S, GOESSLER, Walter, MOLENAT, Nathalie, KUEHNELT, Doris, HARRINGTON, Christopher F, SUTTON, Peter G
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.08.2003; Berlin Springer Nature B.V
• Subjects: Acetates - metabolism; Aeromonas - isolation & purification; Animals; Arsenic; Arsenicals - metabolism; arsenobetaine; Bacteria; Bacteria - growth & development; Bacteria - isolation & purification; Bacteria - metabolism; Bacteriology; Biodegradation; Biodegradation, Environmental; Biological and medical sciences; Bivalvia - microbiology; Cacodylic Acid - metabolism; Carbon; Chromatography, High Pressure Liquid; dimethylarsinoylacetate; Fundamental and applied biological sciences. Psychology; Liquid chromatography; Marine; Mass Spectrometry; Metabolism. Enzymes; Microbiology; Microorganisms; Mytilus edulis; Paenibacillus; Pseudomonas; Pseudomonas - isolation & purification; Pseudomonas - metabolism; Pseudomonadales; Paenibacillus; Mytilus edulis; HPLC chromatography; Pseudomonas; Arsenites; Enzymatic activity; Bivalvia; Biotransformation; Arsenic acid; Bacteria; Pseudomonadaceae; Invertebrata; Mollusca; Degradation product
• ISSN: 0302-8933; 1432-072X
• DOI: 10.1007/s00203-003-0569-9

Microorganisms from Mytilus edulis (marine mussel) degraded arsenobetaine, with the formation of trimethylarsine oxide, dimethylarsinate and methylarsonate. Four bacterial isolates from these mixed-cultures were shown by HPLC/hydride generation-atomic fluorescence spectroscopy (HPLC/HG-AFS) analysis to degrade arsenobetaine to dimethylarsinate in pure culture; there was no evidence of trimethylarsine oxide formation. Two of the isolates ( Paenibacillussp. strain 13943 and Pseudomonas sp. strain 13944) were shown by HPLC/inductively coupled plasma-mass spectrometry (HPLC/ICPMS) analysis to degrade arsenobetaine by initial cleavage of a methyl-arsenic bond to form dimethylarsinoylacetate, with subsequent cleavage of the carboxymethyl-arsenic bond to yield dimethylarsinate. Arsenobetaine biodegradation by pure cultures was biphasic, with dimethylarsinoylacetate accumulating in culture supernatants during the culture growth phase and its removal accompanying dimethylarsinate formation during a carbon-limited stationary phase. The Paenibacillus sp. also converted exogenously supplied dimethylarsinoylacetate to dimethylarsinate only under carbon-limited conditions. Lysed-cell extracts of the Paenibacillus sp. showed constitutive expression of enzyme(s) capable of arsenobetaine degradation through methyl-arsenic and carboxymethyl-arsenic bond cleavage. The work establishes the capability of particular bacteria to cleave both types of arsenic-carbon bonds of arsenobetaine and demonstrates that mixed-community functioning is not an obligate requirement for arsenobetaine biodegradation.