Myxococcus xanthus biomass as biosorbent for lead

Abstract

This paper deals with lead biosorption by Myxococcus xanthus biomass in which dry biomass, accumulating up to 1·28 mmol of lead g−1, is demonstrated to be a more efficient biosorbent than wet biomass. Dry biomass biosorption was found to be very rapid, reaching equilibrium after 5–10 min. Culture age, the initial lead concentration and pH affected this process, but temperature did not. Furthermore, by using sodium citrate as a desorbent agent, 92·17% of the biosorbed lead could be recovered. It was also established that the biosorbed lead is located on the cellular wall and within the characteristic extracellular polysaccharide of this micro‐organism.

Interactions of microorganisms with rare earth ions and their utilization for separation and environmental technology

“…EPS provide an extensive surface area per unit volume for adsorption of heavy metal ions, such as Pb (Rudd et al 1984). This suggests 6 that the EPS could protect the bacterium in its habitat because these substances facilitate heavy metal fixation surrounding the cell rather than inside the cells (Merroun et al 1998). Merroun et al (2003) reported that Myxococcus xanthus, a soil bacterium of the myxobacteria group, could accumulate 0.6 mmol of La / g of wet biomass and/or 0.99 mmol / g of dry biomass, and a substantial amount of La was fixed in the EPS and in the cell wall.…”

Silver Sorption to Myxococcus xanthus Biomass

“…Considering previous works from our laboratory which have indicated that dry biomass of M. xanthus removed more ef ciently heavy metals than wet biomass Ben Omar et al 1997;Merroun et al 1998), we decided to use dry biomass in these studies. Also, the age of cultures was chosen in agreement with our previous data.…”

“…In the course of our study on the recovery of heavy metals by M. xanthus it was found that dry biomass of this microorganism has the capacity to accumulate uranium and lead extremely well Merroun et al 1998). The similar behavior as was observed for the uptake of these two heavy metals was demonstrated here for silver: dry biomass of M. xanthus accumulates silver ions well.…”

“…This bacterium has previously been shown, in our laboratory, to have good metal binding characteristics, ef ciently accumulating heavy metals, such as UO 2 2C and Pb 2C Merroun et al 1998). M. xanthus is characterized by an abundant production of extracellular polysaccharide (EPS), often referred to as slime.…”

A novel adsorbent for heavy metal remediation in aqueous environments

“…Chromium and cadmium have been selected in this study because of their inherent toxicity to most organisms (Merroun et al,1998;Wan Ngah and Hanafiah, 2008). These metals are major pollutants in South Africa's water resources due to their use in many industries, such as metal plating, mining operations and tanneries.…”