RESUMEN
In order to investigate the microbe-mineral interaction in the micro scale, spatial distribution and speciation of Cu and S in Halothiobacillus HT1 biofilm formed on a CuS surface was examined using synchrotron-based X-ray techniques. Confocal laser scanning microscope (CLSM) results indicated that Halothiobacillus HT1 biofilm formation gave rise to distinct chemical and redox gradients, leading to diverse niches in the biofilm. Live cells were distributed at the air-biofilm and membrane-biofilm interface. CuS was oxidized by Halothiobacillus HT1 biofilm, and copper penetrated into the biofilm. Sulfide was oxidized to cysteine (77.3%), sulfite (3.8%) and sulfonate (18.9%). Cu-cysteine-like species were involved in the copper homeostasis. These results significantly improve our understanding of the interfacial properties of the biofilm-mineral interface.
Asunto(s)
Biopelículas/efectos de los fármacos , Cobre/farmacología , Halothiobacillus/citología , Halothiobacillus/fisiología , Sincrotrones , Halothiobacillus/efectos de los fármacos , Viabilidad Microbiana/efectos de los fármacos , Microscopía Fluorescente , Azufre/aislamiento & purificación , Espectroscopía de Absorción de Rayos X , Rayos XRESUMEN
Amino acid analysis of pure murein isolated from cells of T. neapolitanus revealed the typical constituents of most mureins form Gram-negative bacteria. i.e. glutamic acid, alanine and diaminopimelic acid, but the molecular ratio ot these was unusual, being approximately 1: 1: 1. The reduced amount of alanine was explained by the absence of monomers containing tetrapeptide side chains, as revealed by h. p. 1. c. analysis, [(3)H]glutamic acid, [(3)H]diaminopimelic acid and [(3)H]N-acetylglucosamine were incorporated into the murein and allowed to determine the degree of its crosslinkage (28%) and the occurrence of turnover.