| The phosphorus-dissolving microorganisms have been paid more attention to by scientists in the study of endogenous pollution in eutrophicated lake, since phosphorus-dissolving microorganisms can translate insoluble phosphate into the soluble forms.The identification and capability of phosphate-solubilization of three kinds of microorganisms, labeled H, Z1 and Z2, isolated from Lake Taihu and Lake Erhai were investigated in this study. In this experiment, we discovered that the environmental factors including temperature, concentration of calcium phosphate, incubation time and pH value had great influence on the growth of the three kinds of phosphorus-dissolving microorganisms. The co-cultivation experiments of microbe-H, Z1 and Z2 with two kinds of algae were conducted in order to find the effect of three kinds of phosphorus-dissolving microorganisms on the growth of Microcystis and Anabeana.The main results are showed as follows:(1) According to genetic identification of ITS, these phosphorus-dissolving microorganisms were Rhodotorule sp., Mucor sp. and Trichoderma sp., respectively. The capacity of these three kinds of phosphorus-dissolving microorganisms was in this order:Z2>Z1>H.(2) The suitable pH value of the phosphorus-dissolving microorganisms was 5.5-7.5 and in this range, a negative correlation could be found between the capability of phosphate-solubilization of these microorganisms and the pH of the media. With the temperature ranged from 15℃to 40℃, the dissolving capacity increased with increasing temperature; the isolates Z1 and Z2 showed higher phosphorus solubilization under the concentration of Ca3(PO4)2 ranged from 2-5 g/L; the capability of phosphate-solubilization of these microorganisms increased with culture time in 7 days.(3) From co-cultivation experiments of microbe-H, Z1 and Z2 with two kinds of algae, the result could be found that three kinds of phosphorus-dissolving microorganisms played an important role in promoting growth of Microcystis and Anabeana by providing soluble phosphate ions; these two kinds of algae had no obvious effect on the capacity of phosphate-solubilization of microbe-Z1 and Z2 except microbe-H. |
