Prosthecate Bacterium Asticcacaulis sp. VKM B-2400 from Ochreous Creek Deposits and Its Growth upon a High Iron Content

Abstract

This paper reports the isolation and identification of the stalked prosthecate bacterium Asticcacaulis sp. VKM B-2400 culture from the ochreous deposits of a creek with predominating iron-oxidizing bacteria. Molecular genetic analysis has demonstrated that, according to the nucleotide sequence of the 1368 bp 16S rRNA gene fragment, the isolated strain is most closely related (99% identity) to the A. taihuensis species previously described based on a single strain. A description of the Asticcacaulis sp. strain VKM B-2400 is provided. It has been demonstrated that the isolated bacteria, the inhabitants of ochreous deposits, neither convert nor accumulate Fe³⁺ compounds and transform their metabolism at high dissolved iron concentrations (0.5 mM). The indicators of the change in metabolism were biomass peptide composition and the accumulation of storage organic compounds in the bacterial cells. The data obtained in the present article is the first report of the effects of high concentrations of dissolved iron (Fe³⁺) on the metabolism of bacteria not belonging to iron-oxidizing bacteria.