Multiple metal tolerance and biosorption of cadmium by Candida tropicalis isolated from industrial effluents: glutathione as detoxifying agent

Abstract

The ability of cadmium uptake by metal-resistant yeast, Candida tropicalis, from the liquid medium and wastewater was evaluated. The minimum inhibitory concentration of Cd(2+) against C. tropicalis was 2,500 mg L(-1). The yeast also showed tolerance toward Zn(2+) (1,400 mg L(-1)), Ni(2+) (1,000 mg L(-1)), Hg(2+) (1,400 mg L(-1)), Cu(2+) (1,000 mg L(-1)), Cr(6+) (1,200 mg L(-1)), and Pb(2+) (1,000 mg L(-1)). The yeast isolate showed typical growth curves, but lag and log phases extended in the presence of cadmium. The yeast isolate showed optimum growth at 30°C and pH 8. The metal processing ability of the isolate was determined in a medium containing 100 mg L(-1) of Cd(2+). C. tropicalis could decline Cd(2+) 70%, 85%, and 92% from the medium after 48, 96, and 144 h, respectively. C. tropicalis was also able to remove Cd(2+) 40% and 78% from the wastewater after 6 and 12 days, respectively. Cd produced an increase in glutathione (GSH) and nonprotein thiol levels by 135% and 134% at 100-mg L(-1) concentration, respectively. An increase in the synthesis of GSH is involved in metal tolerance, and the presence of increasing GSH concentrations may be a marker for high metal stress in C. tropicalis. C. tropicalis, which is resistant to heavy metal ions and is adaptable to the local environmental conditions, may be employed for metal detoxification operations.

Redox Proteomics Changes in the Fungal Pathogen Trichosporon asahii on Arsenic Exposure: Identification of Protein Responses to Metal-Induced Oxidative Stress in an Environmentally-Sampled Isolate

“…Whilst screening for pollutant-resistant environmental fungi, a metal-resistant yeast was serendipitously isolated from wastewater of a textile plant in Lahore, Pakistan, [56], [57]. Nucleotide sequences were determined at the Center of Excellence in Molecular Biology, Lahore, Pakistan and identity with T. asahii confirmed using the basic local alignment search tool ().…”

Cadmium resistance mechanism in Escherichia coli P4 and its potential use to bioremediate environmental cadmium

“…It is reported as a free radical scavenger as it has high affinity for metal ions due to its cysteine residues. Thus, it helps to protect the cell from the negative effects caused by heavy metal ions including Cd +2 (Meister and Anderson 1983;Rehman and Anjum 2011). It occurs in GSH as well as in GSSG, but the ratio of GSH to GSSG is kept constant.…”

Selected enzyme activities of urban heavy metal-polluted soils in the presence and absence of an oligochaete, Lampito mauritii (Kinberg)

“…Heavy metals are known microbial growth inhibitors [8,[24][25][26][27]. The inverse relationships between soil enzyme activities and heavy metals have already been reported by several studies [10,28].…”