Bioaccumulation and biosorption of copper(II) and chromium(III) from aqueous solutions by Pichia stipitis yeast

- Biodegradability of Oily Wastewater Using Rotating Biological Contactor Combined with an External Membrane

“…At higher pH levels (pH 5), more ligands with negative charges would be exposed, with the subsequent increase in attraction sites to positively charged metal ion [25]. Some researchers have also investigated the effect of pH on the biosorption of toxic metals and found similar results [26,27,28,29]. The maximum removal of copper was observed at 30uC for the two types of biomass ( Figure 1C, p,0.0001 in both cases).…”

“…The maximum removal of copper was observed at 30uC for the two types of biomass ( Figure 1C, p,0.0001 in both cases). The influence of temperature on the sorption of metals has also been reported for the yeast Pichia stipitis [28] and Rhodotorula sp. Y11 [29], for the bacterium Morganella pyschrotolerans [30] and for the plant Cymbopogon flexuosus [31] and others.…”

Bioaccumulation of heavy metals on adapted Aspergillus foetidus

“…The lag phase represents the period required by the A. foetidus to adapt to a new environment until the formation of growth enzymes and intermediates accumulate sufficiently to allow growth. The longer adaptation period reflected the rise in toxic effects of increasing concentrations heavy metals (Yilmazer and Saracoglu 2009). In a similar manner, the rate of the initial growth phase and maximum tolerance index under the stationary growth phase were also reduced as metal concentrations increased.…”

“…Recent studies on the use of heavy metal tolerant organisms have had some success in efficient bioaccumulation of high concentrations of heavy metals. These have been developed by adaptation in laboratories (de Siloniz et al 2002;Kocberber and Donmez 2007;Yilmazer and Saracoglu 2009), isolated from polluted environments (Kocberber and Donmez 2007) and by genetic engineering (Deng and Wilson 2001). Current studies on the efficacy of these organisms, however, have focused on the bioaccumulation of single metals.…”

“…The effectiveness of the micro-organisms in these processes, however is disadvantaged by the abiotic stress or toxicity of the pollutants that are being accumulated. Toxic metal ions form complexes with cellular membrane, which causes the loss of organisms integrity and impairs their function (Yilmazer and Saracoglu 2009). High concentrations of heavy metals are therefore deemed difficult or impossible to treat by bioaccumulation.…”