Nickel and various heavy metals are known for their toxic effects on human health and the environment. A number of conventional technologies (such as ion exchange, chemical precipitation, chemical oxidation) have been developed for metal removal and detoxification from wastewater. However, these processes have been shown to be expensive and inefficient. For these reasons, biological process has been considered as an attractive alternative to physico-chemical methods leading to the clean up of metal-contaminated environments. Heavy metals resistant microorganisms involved in this biological process are able to uptake both soluble and particulate forms of metals either through bioaccumulation (living cells) and biosorption (dead cells). In our study, a collection of 90 bacterial strains assigned to diverse species of Bacillus, Proteobacteria and Actinobacteria, was screened for multi-heavy metals resistance and accumulation capability. Taking in account the affinity of exopolysaccharide for metals binding, our collection has been also screened for exopolysaccharide production. Moreover the active nickel removal ability was investigated by ICP-MS and the amplification of specific metal-resistance genes nccA, cnr3 and nrbE encoding for nickel-cobalt-cadmium resistance, was performed. Our results revealed that strains affiliated to Actinobacteria and Proteobacteria were able to resist to high nickel concentrations ranged from 0.5 to 1 mM. One strain identified as Microbacterium foliorum was found to have the highest tolerance to Ni2+ (2 mM). A weak nickel accumulation has been detected in selected bacteria. Preliminary results showed that there was no implication of microbial exopolysaccharide production in nickel accumulation. Further experiments are currently in progress in order to improve the efficiency of nickel removal process.
|Titolo:||Screening of nickel tolerant bacteria and assessing for genes encoding for nickel resistance|
ANDREONI, VINCENZINA (Penultimo)
|Data di pubblicazione:||set-2013|
|Settore Scientifico Disciplinare:||Settore AGR/16 - Microbiologia Agraria|
|Enti collegati al convegno:||Società Italiana di Microbiologia Generale e Biotecnologie Microbiche|
|Citazione:||Screening of nickel tolerant bacteria and assessing for genes encoding for nickel resistance / B. Ettoumi, M. Colombo, A. Corsini, V. Andreoni, L. Cavalca. ((Intervento presentato al 30. convegno MICROBIOLOGY 2013 : Meeting of the Società Italiana di Microbiologia Generale e Biotecnologie Microbiche (SIMGBM) tenutosi a Ischia nel 2013.|
|Appare nelle tipologie:||14 - Intervento a convegno non pubblicato|