This study was designed to screen and identify cadmium-resistant fungi and characterize its cadmium adsorption.A cadmium-resistant strain(HD228)was isolated from cadmium-polluted paddy soil by using the Cd^2+concentra...This study was designed to screen and identify cadmium-resistant fungi and characterize its cadmium adsorption.A cadmium-resistant strain(HD228)was isolated from cadmium-polluted paddy soil by using the Cd^2+concentration gradient pressure domestication method.According to the morphological characteristics and the analysis of internal transcribed spacers(ITS)region gene sequence phylogenesis,the strain was identified as Trichoderma asperellum.This strain was resistant to Cd at 22 mmol/L with a Cd adsorption rate of up to 79.88%,and it was also resistant to other heavy metals such as Pb,Zn and Cu.The colony diameter decreased as the heavy metal concentration increased,and the colony was out-of-shape when the Cd^2+concentration was 20 mmol/L.The strain HD228 was found to grow well at pH 4 to 8 and a temperature between 20 and 35℃.The optimal growth conditions were established to be pH 5 and temperature of 30℃.Fermented liquid of the strain is neither disease-causing nor inhibitory to rice seedling emergence,and indeed it improves rice seedling and root growth and enhances rice’s detoxification ability under Cd stress.Thus,the Cd-resistant fungus HD228 has the potential for the treatment of Cd-polluted rice paddies.展开更多
基金Supported by Mutant Library Construction and Cloning of the Agrobacterium Tumefaciens-mediated Penicillium CN35’s Cd-resistant Gene(2017JC73,2018JJ3288)~~
文摘This study was designed to screen and identify cadmium-resistant fungi and characterize its cadmium adsorption.A cadmium-resistant strain(HD228)was isolated from cadmium-polluted paddy soil by using the Cd^2+concentration gradient pressure domestication method.According to the morphological characteristics and the analysis of internal transcribed spacers(ITS)region gene sequence phylogenesis,the strain was identified as Trichoderma asperellum.This strain was resistant to Cd at 22 mmol/L with a Cd adsorption rate of up to 79.88%,and it was also resistant to other heavy metals such as Pb,Zn and Cu.The colony diameter decreased as the heavy metal concentration increased,and the colony was out-of-shape when the Cd^2+concentration was 20 mmol/L.The strain HD228 was found to grow well at pH 4 to 8 and a temperature between 20 and 35℃.The optimal growth conditions were established to be pH 5 and temperature of 30℃.Fermented liquid of the strain is neither disease-causing nor inhibitory to rice seedling emergence,and indeed it improves rice seedling and root growth and enhances rice’s detoxification ability under Cd stress.Thus,the Cd-resistant fungus HD228 has the potential for the treatment of Cd-polluted rice paddies.
