RESUMEN
The investigation of the degradation of thiodiglycol (the major product of mustard gas hydrolysis) by Alcaligenes xylosoxydans subsp. denitrificans strain TD2 showed that thiodiglycol is metabolized through the oxidation of its primary alcohol groups and the subsequent cleavage of C-S bonds in the intermediate products, thiodiglycolic and thioglycolic acids. The end products of these reactions are SO4(2-) ions and acetate, the latter being involved in the central metabolism of strain TD2. The oxidation of the sulfur atom gives rise to diglycolsulfoxide, which is recalcitrant to further microbial degradation. Based on the data obtained, a metabolic pathway of thiodiglycol transformation by A. xylosoxydans subsp. denitrificans strain TD2 is proposed.
Asunto(s)
Alcaligenes/metabolismo , Compuestos de Sulfhidrilo/metabolismo , Alcaligenes/crecimiento & desarrollo , Oxidación-Reducción , Compuestos de Sulfhidrilo/química , Tioglicolatos/análisis , Tioglicolatos/metabolismoRESUMEN
The Alcaligenes xylosoxydans subsp. denitrificans strain TD1 capable of degrading thiodiglycol (TDG), a breakdown product of mustard gas, was isolated from soil contaminated with breakdown products of this chemical warfare agent. The selected stable variant of TD1 (strain TD2) can grow on TDG with a lag phase of 4-8 h and a specific growth rate of 0.04-0.045 h-1. Optimal conditions for the biodegradation of TDG (pH, the concentration of TDG in the medium, and its relative content with respect to the bacterial biomass) were determined. TDG was found to be degraded with the formation of diglycolsulfoxide and thiodiglycolic acid. The data obtained can be used to develop approaches to the bioremediation of mustard gas-contaminated soils.
Asunto(s)
Alcaligenes/metabolismo , Contaminantes Ambientales/metabolismo , Gas Mostaza/metabolismo , Microbiología del Suelo , Compuestos de Sulfhidrilo/metabolismo , Alcaligenes/crecimiento & desarrollo , Alcaligenes/aislamiento & purificación , Biodegradación Ambiental , Medios de Cultivo , Concentración de Iones de Hidrógeno , Sulfóxidos/metabolismo , Tioglicolatos/metabolismoRESUMEN
Using a synthetic medium supplemented with biphenyl (a polycyclic aromatic hydrocarbon), a new bacterial strain of Citrobacter freundii was isolated from enrichment cultures containing soil and industrial wastewater samples of the Serpukhov Condenser Factory. This strain was found to be capable of degrading biphenyl under anaerobic conditions in the course of nitrate reduction. When the initial concentration of biphenyl in culture medium equaled 150 mg/l, the culture with a titer of 10(9) cells/ml degraded up to 26-28% of biphenyl in 3 days (28 degrees C). At 250 mg/l, the culture with a titer of 10(7) cells/ml degraded 15% of biphenyl in 21 days. Approximately 10% of the substrate consumed was utilized completely, whereas the remainder underwent transformation.
Asunto(s)
Compuestos de Bifenilo/metabolismo , Citrobacter freundii/metabolismo , Microbiología del Suelo , Anaerobiosis , Biodegradación Ambiental , Citrobacter freundii/aislamiento & purificación , Medios de Cultivo , Residuos Industriales , Federación de Rusia , Temperatura , Factores de TiempoRESUMEN
Five naphthalene- and salicylate-utilizing Pseudomonas putida strains cultivated for a long time on phenanthrene produced mutants capable of growing on this substrate and 1-hydroxy-2-naphthoate as the sole sources of carbon and energy. The mutants catabolize phenanthrene with the formation of 1-hydroxy-2-naphthoate, 2-hydroxy-1-naphthoate, salicylate, and catechol. The latter products are further metabolized by the meta- and ortho-cleavage pathways. In all five mutants, naphthalene and phenanthrene are utilized with the involvement of plasmid-borne genes. The acquired ability of naphthalene-degrading strains to grow on phenanthrene is explained by the fact that the inducible character of the synthesis of naphthalene dioxygenase, the key enzyme of naphthalene and phenanthrene degradation, becomes constitutive.
Asunto(s)
Mutación , Naftalenos/metabolismo , Fenantrenos/metabolismo , Pseudomonas putida/metabolismo , Biodegradación Ambiental , Medios de Cultivo , Hidrólisis , Pseudomonas putida/genéticaRESUMEN
The effect of sodium salicylate on the population dynamics of the rhizobacterium Pseudomonas aureofaciens BS1393 and its variant bearing the naphthalene biodegradation plasmid pBS216 was studied in the wheat rhizoplane and adjacent soil. Optimum salicylate concentration for the maintenance of the plasmid-bearing strain and for the normal growth of wheat was found to be 250 micrograms/g soil. When the soil was supplemented with salicylate, the population of P. aureofaciens BS1393(pBS216) in the wheat rhizoplane and adjacent soil was, respectively, 4- and 20-fold higher than that of the parent strain lacking the plasmid.
Asunto(s)
Pseudomonas/aislamiento & purificación , Salicilato de Sodio/farmacología , Microbiología del Suelo , Triticum/microbiología , Cromatografía Líquida de Alta Presión , Raíces de Plantas/microbiología , Pseudomonas/crecimiento & desarrollo , Especificidad de la EspecieAsunto(s)
Adamantano/farmacocinética , Pseudomonas putida/metabolismo , Rhodotorula/metabolismo , Adamantano/análogos & derivados , Biotransformación , Alcanfor 5-Monooxigenasa , Cromatografía de Gases , Sistema Enzimático del Citocromo P-450/metabolismo , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Oxigenasas de Función Mixta/metabolismo , Pseudomonas putida/enzimología , Rhodotorula/enzimologíaRESUMEN
Pseudomonas strains harboring plasmids pBS3, pBS4, NAH7 were shown to carry out initial transformation of dibenzofurane to 4-[2'-(3'-hydroxy)-benzofuranyl]-2-keto-3-butenic acid due to broad substrate specificity of the enzymes of naphthalene catabolism nahA, nahB, nahC and nahD. These strains did not grow on dibenzofurane because of the inability of the enzyme nahE to split pyruvate of 4-[2'-(3' hydroxy)-benzofuranyl]-2-keto-3-butenic acid, which leads to accumulation of the latter. The strains harboring plasmids pBS2 and NPL-1 are not capable of any transformation of dibenzofurane.