Phosphonate degradation by Spirulina strains: Cyanobacterial biofilters for the removal of anticorrosive polyphosphonates from wastewater

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• 作者：Giuseppe Forlani^a ; ^flg@unife.it ; Valentina Prearo^a ; Dorota Wieczorek^b ; Paweł ; Kafarski^b ; ^c ; Jacek Lipok^b
• 关键词：Polyphosphonate ; Xenobiotic biodegradation ; ³¹P NMR ; Spirulina spp. ; Wastewater treatment ; Bioremediation
• 刊名：Enzyme and Microbial Technology
• 出版年：2011
• 出版时间：7 March 2011
• 年：2011
• 卷：48
• 期：3
• 页码：299-305
• 全文大小：864 K

文摘

The ability of Spirulina spp. to metabolize the recalcitrant xenobiotic Dequest 2054^® [hexamethylenediamine-N,N,N′,N′-tetrakis(methylphosphonic acid)], a CaSO₄ inhibitor used for boiler treatment and reverse osmosis desalination, was investigated. The compound served as sole source of phosphorus, but not of nitrogen, for cyanobacterial growth. In vivo utilization was followed by ³¹P NMR analysis. The disappearance of the polyphosphonate proceeded only with actively dividing cells, and no release of inorganic phosphate was evident. However, no difference was found between P-starved and P-fed cultures. Maximal utilization reached 1.0 ± 0.2 mmol l⁻¹, corresponding to 0.56 ± 0.11 mmol g⁻¹ dry biomass, thus residual amounts were still present in the exhausted medium when the compound was supplied at higher initial concentrations. At low substrate levels metabolism rates were lower, suggesting that a concentration-driven uptake may represent a limiting step during the biodegradation process. The compound was not retained by biocolumns made with immobilized cyanobacterial cells, either alive or dead. A lab-scale pilot plant, consisting of a series of sequentially connected vessels containing an actively proliferating algal culture, was built and tested for wastewater treatment. Results showed 50 % removal of the polyphosphonate added to an initial concentration of 2.5 mM. Although further optimization will be required, data strengthen the possibility of using cyanobacterial strains for bioremediation purposes.