Exploration of potential jarosite biomineralization mechanism based on extracellular polymer substances of Purpureocillium lilacinum Y3
2020
Xia, Mingchen | Bao, Peng | Peng, Tangjian | Liu, Ajuan | Shen, Li | Yu, Runlan | Liu, Yuandong | Li, Jiaokun | Wu, Xueling | Huang, Caoming | Chen, Miao | Qiu, Guanzhou | Zeng, Weimin
In the present study, the mechanism of jarosite biosynthesis mediated by extracellular polymer substances (EPSs) of Purpureocillium lilacinum strain Y3 at gene level was investigated. Yellow-ocher jarosite minerals covered mycelia pellets entirely within 72h, corresponding to a reduction of Fe³⁺ of 70.9% in the biomineralization process induced by P. lilacinum Y3. The maximum biomass accumulation reached to 12.9 g/L in pure culture, 2.8 g/L with only 0.02M Fe³⁺ addition, and 6.4 g/L with both 0.02M Fe³⁺ and 0.1M K⁺ addition, respectively, indicating that jarosite biosynthesis largely alleviated the inhibition of Fe³⁺ to the fungal strain. Thereafter, the analysis of EPSs compositions suggested that protein content was affected more evidently than polysaccharides in the biomineralization system. Furthermore, real time quantitative PCR assays revealed that signal transduction genes and abundance of membrane transporters were activated quickly in responding to the stimulation of Fe³⁺ and fungus-mineral interactions. Then, the expression of adhesive proteins and extracellular proteins was highly up-regulated to facilitate the formation of jarosite minerals on the cell surface. Finally, X-ray photoelectron spectroscopy analysis supported that amine, carboxyl, phosphate groups present on the mycelia provided Fe³⁺ and K⁺ binding sites for biosynthesis of jarosite.
显示更多 [+] 显示较少 [-]