Now showing 1 - 2 of 2
  • Publication
    Simultaneous removal of malachite green and hexavalent chromium by Cunninghamella elegans biofilm in a semi-continuous system
    The present study was conducted to evaluate the potential of the fungus Cunninghamella elegans for simultaneous decolourisation of a triphenylmethane dye malachite green (MG) and hexavalent chromium [Cr(VI)] in the same media. This fungus can degrade MG through its reduction into leucomalachite green and then demethylation followed by oxidative cleavage. Along with MG degradation, C. elegans biofilm could effectively and repeatedly remove Cr(VI) from the liquid cultures even in the presence of high concentrations (40 g L−1) of NaCl and various other metal ions. C. elegans biofilm was also found to adsorb different dyes (reactive black-5, acid orange 7, direct red 81 and brilliant blue G) concurrently with Cr(VI). Based on its potential for simultaneous removal of dyes and Cr(VI) as well as reusability, C. elegans biofilm is envisaged as an efficient bioresource to devise strategies for treatment of wastewaters loaded with multiple pollutants.
      58Scopus© Citations 39
  • Publication
    Biodegradation of pentafluorosulfanyl-substituted aminophenol in Pseudomonas spp.
    The pentafluorosulfanyl (SF5–) substituent conveys properties that are beneficial to drugs and agrochemicals. As synthetic methodologies improve the number of compounds containing this group will expand and these chemicals may be viewed as emerging pollutants. As many microorganisms can degrade aromatic xenobiotics, we investigated the catabolism of SF5-substituted aminophenols by bacteria and found that some Pseudomonas spp. can utilise these compounds as sole carbon and energy sources. GC–MS analysis of the culture supernatants from cultures grown in 5-(pentafluorosulfanyl) 2-aminophenol demonstrated the presence of the N-acetylated derivative of the starting substrate and 4-(pentafluorosulfanyl)catechol. Biotransformation experiments with re-suspended cells were also conducted and fluorine-19 NMR analyses of the organic extract and aqueous fraction from suspended cell experiments revealed new resonances of SF5-substituted intermediates. Supplementation of suspended cell cultures with yeast extract dramatically improved the degradation of the substrate as well as the release of fluoride ion. 4-(Pentafluorosulfanyl)catechol was shown to be a shunt metabolite and toxic to some of the bacteria. This is the first study to demonstrate that microorganisms can biodegrade SF5-substituted aromatic compounds releasing fluoride ion, and biotransform them generating a toxic metabolite.
    Scopus© Citations 16  355