Several Acinetobacter species have been reported to be able to grow on sites polluted by crude oil (oil spills, oil tankers) due to the production of specific catabolic enzymes able to degrade aliphatic and/or aromatic molecules. Sometimes these substrates are used as the sole carbon and energy source while otherwise they can be degraded by co-metabolism. The finding of specific catabolic enzymes can supply information about the degradation pathway. Functional proteomics is a useful tool to investigate bacterial responses to environmental stimuli. During aromatic exposure A. radioresistens S13, a fast phenol-degrading strain isolated in our lab for bioremediation purposes, biosynthesizes specific enzymes, absent in acetate cultures, previously detected by both proteomic and transcript analyses. Besides enzymes for either phenol or benzoate catabolism, we found, in aromatic stimulated conditions, de novo production or over-expression of some “satellite” proteins located both in the cytosol and in the (inner and outer) membranes. The 2-DE gels were performed in both the acidic and the alkaline pH ranges and proteins have been identified by the ESI Ion trap MS, due to the lack of a known genome in this Acinetobacter species. Proteins and glycoproteins detected when phenol (P) or benzoate (B) were the only carbon source can be divided in 6 functional groups: a) biosurfactants; b) proteins involved in the modification of Acinetobacter surface properties; c) stress proteins; d) transport systems; e) pH homeostasis and phosphate metabolism; f) lipid metabolism. Some of them proved to be abundant in certain growth phases. Even if B and P cultures share the majority of protein, nevertheless some proteins (or protein isozymes) are specifically induced by B or P. The present investigation allows a better understanding of A. radioresistens S13 physiological responses to aromatics, demonstrating that the adaptive responses to polluted environments, include a sequence of strategies to ameliorate substrate availability and tolerance.
AUXILIARY PROTEINS FOR AROMATIC TOLERANCE AND PROCESSING, DETECTED IN A. RADIORESISTENS S13 PROTEOME.
PESSIONE, Enrica;MAZZOLI, Roberto;FATTORI, Paolo;LAMBERTI, Cristina;GIUNTA, Carlo
2006-01-01
Abstract
Several Acinetobacter species have been reported to be able to grow on sites polluted by crude oil (oil spills, oil tankers) due to the production of specific catabolic enzymes able to degrade aliphatic and/or aromatic molecules. Sometimes these substrates are used as the sole carbon and energy source while otherwise they can be degraded by co-metabolism. The finding of specific catabolic enzymes can supply information about the degradation pathway. Functional proteomics is a useful tool to investigate bacterial responses to environmental stimuli. During aromatic exposure A. radioresistens S13, a fast phenol-degrading strain isolated in our lab for bioremediation purposes, biosynthesizes specific enzymes, absent in acetate cultures, previously detected by both proteomic and transcript analyses. Besides enzymes for either phenol or benzoate catabolism, we found, in aromatic stimulated conditions, de novo production or over-expression of some “satellite” proteins located both in the cytosol and in the (inner and outer) membranes. The 2-DE gels were performed in both the acidic and the alkaline pH ranges and proteins have been identified by the ESI Ion trap MS, due to the lack of a known genome in this Acinetobacter species. Proteins and glycoproteins detected when phenol (P) or benzoate (B) were the only carbon source can be divided in 6 functional groups: a) biosurfactants; b) proteins involved in the modification of Acinetobacter surface properties; c) stress proteins; d) transport systems; e) pH homeostasis and phosphate metabolism; f) lipid metabolism. Some of them proved to be abundant in certain growth phases. Even if B and P cultures share the majority of protein, nevertheless some proteins (or protein isozymes) are specifically induced by B or P. The present investigation allows a better understanding of A. radioresistens S13 physiological responses to aromatics, demonstrating that the adaptive responses to polluted environments, include a sequence of strategies to ameliorate substrate availability and tolerance.
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