Biosorption of Heavy Metals by Candida albicans

Abstract

The objective of this work was to study the resistance and removal capacity of heavy metals by the yeast Candida albicans. The resistance of some heavy metals was analyzed: the yeast grows in 2000 ppm of chromium, zinc, lead, and copper, 1500 ppm of arsenic (III), 500 ppm of silver, and little bit in cobalt (300 ppm) and mercury and cadmium (200 ppm). Analyzing its potential to remove heavy metals, it can efficiently remove is as follows: Cr(VI) (76%), lead (57%), silver (51%), cadmium (46%), fairly arsenic(III) (40% with the modified biomass), cobalt (37%), mercury (36%), copper (31%), little bit zinc (22%), and fluoride (10%). We determine the optimal characteristics for chromium(VI) removal in living cells and death biomass. The ideal conditions for the removal of 50 mg/L of Cr(VI) in living cells were 28°C, pH 7.0, and 10 × 10 6 yeast/mL, with glycerol-like carbon source. In dead yeast biomass, the ideal conditions for removal of metal are 200 mg/L of Cr(VI), 60°C, pH 1.0, 20 h, and 5 g of biomass.

Bioremoval of Cobalt(II) from Aqueous Solution by Three Different and Resistant Fungal Biomasses

“…The cells of the analyzed strains grew on LMM supplemented with different concentrations of Co(II) we obtained for the growth of three fungi at 500 mg/L: 33, 24, and 37 mg of dry weight, for Aspergillus niger , Paecilomyces sp., and Penicillium sp., respectively. It is suggested that the fungi growing at concentrations up to 500 mg/L are tolerant and/or resistant to the metal, which is similar to that reported by Acosta-Rodríguez et al [10]; it is similar for Candida albicans , which grew at 300 mg/L of Co(II), for eight species of Penicillium isolated from Brazilian soil (tolerance between 50 and 500 µ g/mL); for Pichia guilliermondii isolated from acidic mine water in Peru, with a resistance to 400–600 mM of Co(II) [23]; and for the bacterium Pseudomonas aeruginosa SPB-1 (2.5 mM) [16], similar to the environmental-contaminant fungus Penicillium sp. IA-01 and which grew at a concentration of 500 ppm of Cr(VI) in an area near the Faculty of Chemical Sciences in San Luis Potosi, México, under the same conditions [24].…”

“…In this context, biotechnology is bringing about solutions more aligned with the modern ecological demand for green processes [7]. Fungi show a capacity to absorb a great diversity of contaminants such as hydrocarbons [8], industrial wastewater [9], and metals [10] on environmentally friendly processes. Microorganisms from different genera can be promptly isolated from the environment, are fast growing, and have been showing ready adaptation to a series of challenging environmental conditions, generating many possibilities for bioremediation of cobalt, like different species of fungi: Penicillium sp.…”

Bioremoval of Different Heavy Metals by the Resistant Fungal StrainAspergillus niger

“…In addition to the above, this fungus was conditioned for years under conditions of biological stress and was inoculated in culture media containing between 0 and 500 ppm of different heavy metals such as chromium, lead, cadmium, arsenic, etc. For the isolation, growth, and pH calibration, we carried out the methodology of Acosta-Rodríguez et al [ 21 ] as follows: on Petri dishes containing modified Lee's minimal medium (LMM) (with 0.25% KH 2 PO 4 , 0.20% MgSO 4 , 0.50% (NH 4 ) 2 SO 4 , 0.50% NaCl, 0.25% glucose, and 2% agar) supplemented with 500 mg/L of K 2 CrO 4 . The pH of the medium was adjusted with a pH meter Corning Pinnacle 540 and maintained at 5.3 with 100 mmol/L of citrate phosphate buffer.…”

“…For the resistance test, we followed the methods of Acosta-Rodríguez et al [ 21 ], where Petri dishes were prepared with Sabouraud Dextrose Agar, added with different heavy metals salts. The prepared plates were inoculated with 1 × 10 6 spores/mL, uniformly spread throughout the dishes, and incubated at 28°C for 7 days, and the growth of the plates was compared with a control.…”

“…For their propagation, 1000 mL Erlenmeyer flasks containing 600 mL of thioglycolate broth (8 g/L) were used. The prepared flasks were inoculated with 1 × 10 6 spores/mL and were incubated at 28°C, with constant stirring (100 rpm) [ 21 ]. After 5 days of incubation, the cells were filtered in Whatman paper No.…”