Hefnawy M A, Razak A A
Botany Department, Faculty of Science, Menoufia Unviersity, Shebin El-Kom, Egypt.
Folia Microbiol (Praha). 1998;43(5):453-8. doi: 10.1007/BF02820790.
A strain of Fusarium oxysporum tolerated copper in the growth medium at concentrations up to 600 mg/L. The optimum growth was obtained at 200 mg Cu/L. The mycelium acquired a blue color in the presence of copper. The copper content of isolated cell walls obtained from mycelium grown in the presence of 600 mg Cu/L was 1.5 times higher than that of cell walls obtained from mycelium grown at 200 mg Cu/L and it contained 2.2 and 3.3% copper at 200 and 600 mg Cu/L, respectively. The amount of protein and total sugars increased in both the mycelium and its isolated cell walls in the presence of copper in the growth medium, chitin was also increased in the cell wall, reaching its maximum amount at 200 mg Cu/L--about 2.4 times higher than without copper. Most of amino acid concentrations in the cell wall were increased in the presence of 200 mg Cu/L and decreased above this concentration. Isoleucine, leucine, tyrosine, phenylalanine, and arginine showed the highest increase at this concentration. The altered cell walls obtained from mycelium grown at 200 and 400 mg Cu/L could rebind individual metals more than the control cell walls could. Rebinding of individual metals was in the order Zn > Fe > Ni > Cu > Co. Rebinding of copper by isolated cell walls depended on pH and temperature.
一种尖孢镰刀菌菌株能够耐受生长培养基中浓度高达600毫克/升的铜。在200毫克/升铜的条件下可获得最佳生长状态。在有铜存在的情况下，菌丝体呈现蓝色。从在600毫克/升铜环境中生长的菌丝体分离得到的细胞壁中的铜含量，比在200毫克/升铜环境中生长的菌丝体分离得到的细胞壁中的铜含量高1.5倍，且在200毫克/升和600毫克/升铜浓度下，其铜含量分别为2.2%和3.3%。在生长培养基中有铜存在时，菌丝体及其分离得到的细胞壁中的蛋白质和总糖含量均增加，细胞壁中的几丁质也增加，在200毫克/升铜时达到最大值——比无铜时高约2.4倍。在200毫克/升铜存在时，细胞壁中的大多数氨基酸浓度增加，高于此浓度则降低。异亮氨酸、亮氨酸、酪氨酸、苯丙氨酸和精氨酸在此浓度下增加幅度最大。从在200毫克/升和400毫克/升铜环境中生长的菌丝体获得的改变后的细胞壁，比对照细胞壁能更多地重新结合单一金属。单一金属的重新结合顺序为锌>铁>镍>铜>钴。分离得到的细胞壁对铜的重新结合取决于pH值和温度。
