Słaba Mirosława, Szewczyk Rafał, Bernat Przemysław, Długoński Jerzy
Department of Industrial Microbiology and Biotechnology, University of Łódź, Banacha 12/16, Łódź, Poland.
Sci Total Environ. 2009 Jun 15;407(13):4127-33. doi: 10.1016/j.scitotenv.2009.03.023. Epub 2009 Apr 25.
Microbial ability vary when pollutants exist together in the environment in comparison to the presence of single toxic compound. The influence of alachlor and zinc on the growth of the filamentous fungus Paecilomyces marquandii and its ability to eliminate alachlor and zinc has been studied. Their simultaneous presence in the polluted environment is very probable. In liquid cultures the pesticide (50 mg/l) was removed with the efficiency of 85% within 7 days. Beginning from the third day of culturing two derivatives of alachlor were found: N-(2',6'-diethylphenyl)-N-metoxymethyl-acetamide and unstable 2-chloro-N-(2',6'-diethylphenyl)-N-hydroxymethyl-acetamide, the first time detected as product of alachlor metabolisation by filamentous fungus. The herbicide elimination was not inhibited by zinc up to 1.0 mM of the metal content in the culture medium, 5.0-7.5 mM of the metal limited alachlor depletion by 30-50%, whereas a higher zinc concentration stopped this process. Zinc content in P. marquandii mycelium during the incubation in growth medium reached 10-20 mg/g of dry weight and was increased up to 99 mg/g by alachlor, however due to its presence a strong inhibitory effect on growth was observed. It was postulated that the increase in zinc binding by the growing mycelium of P. marquandii in the presence of the pesticide was connected with the changes in the wall and membrane composition induced by simultaneous toxic interaction of zinc and alachlor. Only 15-20% of bound zinc was detected in the cell wall of the fungus, whereas the amount of zinc loaded in the wall of mycelium originating from the cultures incubated in the alachlor presence increased to 60%. Additionally, changes in the profile of fatty acids of cultures with pesticide and metal addition were observed. P. marquandii strain seems to be promising for a potential industrial application. It can both effectively bind zinc and remove alachlor from the mixture of pollutants.
与单一有毒化合物存在的情况相比，当污染物在环境中同时存在时，微生物的能力会有所不同。研究了甲草胺和锌对丝状真菌马尔克拟青霉生长及其去除甲草胺和锌能力的影响。它们在污染环境中同时存在的可能性很大。在液体培养中，农药（50毫克/升）在7天内的去除效率为85%。从培养第三天开始，发现了甲草胺的两种衍生物：N-（2'，6'-二乙基苯基）-N-甲氧基甲基-乙酰胺和不稳定的2-氯-N-（2'，6'-二乙基苯基）-N-羟甲基-乙酰胺，这是首次检测到丝状真菌将甲草胺代谢为该产物。在培养基中金属含量高达1.0毫摩尔时，锌不会抑制除草剂的去除，5.0 - 7.5毫摩尔的金属会使甲草胺的消耗减少30 - 50%，而更高的锌浓度则会阻止这一过程。在生长培养基中培养期间，马尔克拟青霉菌丝体中的锌含量达到10 - 20毫克/克干重，甲草胺存在时会增加到99毫克/克，但由于其存在，观察到对生长有强烈的抑制作用。据推测，在农药存在的情况下，马尔克拟青霉生长菌丝体对锌结合的增加与锌和甲草胺同时产生的毒性相互作用所诱导的细胞壁和膜组成变化有关。在真菌细胞壁中仅检测到15 - 20%的结合锌，而在甲草胺存在下培养的菌丝体壁中加载的锌量增加到60%。此外，观察到添加农药和金属的培养物脂肪酸谱的变化。马尔克拟青霉菌株似乎具有潜在的工业应用前景。它既能有效结合锌，又能从污染物混合物中去除甲草胺。
