Papers by Author: Renata Matlakowska

Abstract: Indigenous microorganisms isolated from organic-rich copper-bearing black shale from the Fore-Sudetic Monocline were able to transform naturally occurring metalloporphyrins in laboratory cultures. It was also demonstrated that these bacteria can utilize synthetic metalloporphyrins as the sole energy and carbon source. The first step in metalloporphyrin biotransformation was identified as the highly effective bioaccumulation of these compounds in bacterial cells. The ability of both living and dead cells to biosorb metalloporphyrins was also confirmed. Besides contributing to the important biogeochemical role of these microorganisms in the environment, their biotransformation activities are of potential use in the bioremediation of copper tailings as well as in the recovery of metals from organic-rich black shale ore, which is not possible using traditional hydrometallurgical procedures.

Abstract: The aim of this review report was to summarize knowledge about arsenic-metabolizing bacteria isolated from Zloty Stok (SW Poland) gold mine and determine their potential role in mobilization of arsenic. Three physiologically different groups of arsenic metabolizing microorganisms (arsenite oxidizers, dissmiliatory arsenate reducers and arsenic resistant microbes) were isolated from the deepest section of Gertruda Adit in Zloty Stok (SW Poland) gold mine. Twenty two strains were isolated from the rock biofilms and seven from arsenic-rich bottom sediments. Analysis of the 16S rRNA gene sequence of isolated bacteria revealed them to be members of the genera: Aeromonas, Arthrobacter, Bacillus, Brevundimonas, Chryseobacterium, Desemzia, Microbacterium, Micrococcus, Paracoccus, Pseudomonas, Rhodococcus, Serratia, Shewanella, Sinorhizobium, Sphingomonas, Stenotrophomonas and Streptomyces. All of the isolated bacteria were resistant to both inorganic arsenic species: arsenate [As(V)] and arsenite [As(III)]. One of the bottom sediments isolates (Sinorhizobium sp. M14) was able to grow on minimal salt medium using arsenite as a source of energy, and was able to release arsenic from arsenopyrite. Two strains (Shewanella sp. O23S and Aeromonas sp. O23A) isolated from bottom sediments were able to grow in the absence of oxygen, by As (V) respiration coupled with lactate oxidation. Based on arsenic metabolic activity of isolated bacteria two different mechanisms of arsenic mobilization from natural minerals (arsenopyrite FeAsS) and secondary ferrous arsenate minerals (scorodite FeAsO4) were proposed.