The biologically-mediated breakdown of chemicals specifically designed to resist biologically-mediated breakdown is an obvious challenge. Quaternary ammonium compounds (QACs) have a number of common uses such as wood preservatives, antistatic agents, corrosion inhibitors, and textile softeners. Widespread use is leading to increasing contamination of water and soils. Gliocladium roseum is a fungus capable of secreting enzymes that cleave QACs resulting in by-products that are readily broken down by common enzymes. Laboratory tests have confirmed G. roseum's ability to grow on QAC-treated wood blocks and decompose the toxic preservative.
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"Quaternary ammonium compounds (QACs) are…widely applied as disinfectants, wood preservatives, antistatic agents, corrosion inhibitors and textile softeners…[and] has resulted in increased presence of these compounds in waste water, waterways, lakes, sludges and soils. These compounds are toxic to aquatic plant and animal organisms." (Zabielska-Matejuk and Czaczyk 2006:461)
"All synthesized mono- and bis-QACs were degraded by mould fungi to a higher degree than DDAC (5a) and didecylmethylpoli(oxy- ethyl)ammonium propionate (5b). These compounds were more easily leached from wood than DDAC and Bardap 26 PRO." (Zabielska-Matejuk and Czaczyk 2006:467)
"[D]egradation of these compounds caused by mould fungi does not involve shortening of alkyl chain, but decomposition of the bond between the nitrogen atoms—carbon atom of alkyl chain, which leads to a loss of surface properties." (Zabielska-Matejuk and Czaczyk 2006:469)
"The changes in copper content in treated wood exposed in moist soil depend on the chemical structure of copper(II) complexes in the anion. Mould fungi, in particular the applied G. [Gliocladium] roseum strains No. 62726, caused 15.5–48.7% degradation." (Zabielska-Matejuk and Czaczyk 2006:474)Journal article
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"All synthesized mono- and bis-QACs were degraded by mould fungi to a higher degree than DDAC (5a) and didecylmethylpoli(oxy- ethyl)ammonium propionate (5b). These compounds were more easily leached from wood than DDAC and Bardap 26 PRO." (Zabielska-Matejuk and Czaczyk 2006:467)
"[D]egradation of these compounds caused by mould fungi does not involve shortening of alkyl chain, but decomposition of the bond between the nitrogen atoms—carbon atom of alkyl chain, which leads to a loss of surface properties." (Zabielska-Matejuk and Czaczyk 2006:469)
"The changes in copper content in treated wood exposed in moist soil depend on the chemical structure of copper(II) complexes in the anion. Mould fungi, in particular the applied G. [Gliocladium] roseum strains No. 62726, caused 15.5–48.7% degradation." (Zabielska-Matejuk and Czaczyk 2006:474)
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