Department of Microbiology, Federal University of Viçosa, Viçosa, Brazil.
Appl Environ Microbiol. 2013 Aug;79(16):4906-13. doi: 10.1128/AEM.01487-13. Epub 2013 Jun 14.
The simultaneous release of various chemical elements with inhibitory potential for phosphate solubilization from rock phosphate (RP) was studied in this work. Al, B, Ba, Ca, F, Fe, Mn, Mo, Na, Ni, Pb, Rb, Si, Sr, V, Zn, and Zr were released concomitantly with P during the solubilization of Araxá RP (Brazil), but only F showed inhibitory effects on the process at the concentrations detected in the growth medium. Besides P solubilization, fluoride decreased fungal growth, citric acid production, and medium acidification by Aspergillus niger. At the maximum concentration found during Araxá RP solubilization (22.9 mg F(-) per liter), fluoride decreased P solubilization by 55%. These findings show that fluoride negatively affects RP solubilization by A. niger through its inhibitory action on the fungal metabolism. Given that fluoride is a common component of RPs, the data presented here suggest that most of the microbial RP solubilization systems studied so far were probably operated under suboptimal conditions.
本工作研究了从磷矿（RP）中同时释放具有溶磷抑制潜力的各种化学元素。在阿拉萨亚 RP（巴西）的溶解过程中，除了 P 之外，Al、B、Ba、Ca、F、Fe、Mn、Mo、Na、Ni、Pb、Rb、Si、Sr、V、Zn 和 Zr 也与 P 同时释放，但只有 F 在生长培养基中检测到的浓度下对该过程表现出抑制作用。除了 P 的溶解，氟化物还降低了黑曲霉的真菌生长、柠檬酸产量和培养基酸化。在阿拉萨亚 RP 溶解过程中发现的最大浓度（每升 22.9 毫克 F(-)）下，氟化物使 P 的溶解减少了 55%。这些发现表明，氟化物通过抑制真菌代谢对 A. niger 的 RP 溶解产生负面影响。鉴于氟化物是 RP 的常见成分，这里提出的资料表明，迄今为止研究的大多数微生物 RP 溶解系统可能是在次优条件下运行的。
