Chromium Adsorption by Three Yeast Strains Isolated from Sediments in Morocco

Biosorption of Heavy Metals by Candida albicans

“…It was found that a higher removal, which is proportional to the biosorption, occurs at 2 days and at a pH of 1.0. It was reported a time of 24 h Cyberlindnera fabianii, Wickerhamomyces anomalus, and Candida tropicalis, at a pH range between 2 and 4 for the three species [27]; the removal of Cr(VI) (100%) by Cyberlindnera fabianii at 48 h [28]; Candida tropicalis isolated from chromium-contaminated site removal 50 mg/L of the metal at 48 h [29]; and Candida intermedia in the biosorption of Cr(III) and Cr(VI) were reported [30]. Permeability and porosity of the cell wall can affect the incubation time of each Advances in Bioremediation and Phytoremediation microorganism, giving greater or lesser exposure of the functional groups in the cell wall of the biomass analyzed [31].…”

“…The maximum removal was observed at pH 5.5 and 7.0 (52 and 53% after 7 days of incubation at 28°C and 100 rpm). The ability to remove by living yeast biomass were found were found at pH 4.0 for C. fabianii HE650139 and W. anomalus HE648168; at pH 3.0 for C. tropicalis HE650140, with a percentage removal of 100%, by all living microorganisms [27]; at pH of 5.0-6.5 for the Hg(II) bioremoval by Yarrowia strains [38]; at an optimum pH for the strains P. jadinii M9 and P. anomala M10 of 7.0 and 3.0, respectively, for Cr(VI) reduction [33]; and a pH between 1 and 2 for the removal of Cr(VI) by Candida utilis [44]. The decrease of pH causes protonation of the adsorbent surface by attracting ions of Cr(VI) in the solution, so it increases the acidity of the solution, and the biosorption is favored for some microorganisms.…”

“…At 60°C, we observed a removal of 100% at 8 days with 200 mg/L, and only 48% with 1 g/L of the metal Advances in Bioremediation and Phytoremediation (Figure 7b), which may be due to sorption happening at low concentrations, but at higher concentrations, possibly when positive positions were saturated, precipitation occurs (which is a slower process) [36]. Some yeasts are not affected by the concentration of the metal, like the three yeast strains isolated from sediments in Morocco [27], and in other yeasts, the removal of metal increases in direct proportion to the increase of the concentration of Cr(VI) in the solution like Rhodotorula mucilaginosa isolated from the effluent of Chittaranjan locomotive workshop effluent samples [25], for Pichia jadinii M9 and Pichia anomala M10 [33], metal-resistant yeast, Candida tropicalis [26]. C. neoformans showed a higher biosorption capacity at low concentrations of metal ions (0.2 mg/L) [18], Rhodotorula mucilaginosa for the removal of copper [37], and Yarrowia strains isolated from sediments of mercury-polluted estuarine water [38].…”

Bioaugmentation of chromium-polluted soil microcosms withCandida tropicalisdiminishes phytoavailable chromium

“…Strain of Candida tropicalis HE650140 used in the present work has been isolated from chromium-contaminated site located in Oued Sebou, Fez (Morocco) (Bahafid et al 2013). The yeast was able to tolerate high concentrations of Cr(VI) in YPG solid medium and also exhibits multiple metal (Ni, Zn, Hg, Pb, Co, Cu and Hg) tolerance.…”

Reviews of Environmental Contamination and Toxicology Volume 233

“…In chromate-resistant strains of Candida maltosa, NAD-dependent chromate-reducing activity was discovered to take place mainly in the soluble protein fraction, with the membrane fraction being less active (Ramírez-Ramírez et al 2004 Bahafid et al (2011) found that Cr(VI) removal by P. anomala initially involves adsorption on functional groups (e.g., carboxyl group, amide I, amide II, amide III, polysaccharides and sulfonate) of cell surfaces, followed by intracellular accumulation and reduction of Cr(VI) to Cr(III). Bahafid et al (2013) also discovered that three yeasts (viz., Cyberlindnera fabianii, Wickerhamomyces anomalus and Candida tropicalis) could be used to effectively remove Cr(VI) via adsorption from contaminated sites. Ksheminska et al (2008) suggested that Cr(VI) gains entrance into yeast cells in an oxy-anionic form in bacteria, i.e., via sulfate-specific transport systems.…”