不同培养条件下两株溶磷真菌溶磷能力的比较

Phosphate-solubilizing capacity of two fungal strains under different culture conditions

【目的】探讨无机磷固、液体培养基及各种基本培养基、磷源等对两株溶磷真菌(FC和H3)溶磷能力的影响,以获得最适合这些菌株发挥溶磷潜力的培养条件。【方法】采用钼蓝比色法测定菌株在无机磷和有机磷液体培养基、简单培养基(SP)、NBRIY、NBRIP和NBRIYP培养基及含不同磷源(磷酸三钙、磷酸铁、磷酸铝、磷酸氢钙和有机磷)、不同浓度磷酸三钙(0.3%、0.5%、0.7%、0.9%和1.1%)培养基的溶磷能力。【结果】FC和H3菌株菌丝在PDA培养基上的最适培养时间为5d。分别在无机磷及有机磷液体培养基、简单培养基(SP)、NBRIY、NBRIP和NBRIYP培养基中培养7d后,FC菌株的溶磷量大小依次为NBRIY>无机磷>NBRIP>SP>有机磷>NBRIYP,H3菌株的溶磷量大小依次为无机磷>NBRIP>SP>NBRIY>有机磷>NBRIYP。以4种不同磷酸盐为磷源,FC菌株对磷酸盐的溶解能力依次为磷酸氢钙>磷酸铝>磷酸铁>磷酸三钙,H3菌株溶解磷酸氢钙的能力较强,其次为磷酸三钙。在含不同浓度磷酸三钙的液体培养基中,两株菌株均能生长并具有溶磷能力,当磷酸三钙浓度为0.5%时,菌株溶磷能力最强。【结论】FC菌株的最适培养基为NBRIY,H3菌株的最适培养基为无机磷培养基。FC和H3菌株对难溶磷酸盐均有溶磷能力,而对磷酸氢钙的溶解能力较强;H3菌株对磷酸三钙的溶解能力较强。

[Objective]The present experiment was aimed to study the effects of different inorganic solid and liquid media and phosphorus sources on phosphate-solubilizing capacity of two fungal strains to find out the best culture conditions for obtaining high potential of phosphate-solubilizing capacity. [Method]The molybdenum blue colorimetry was used to determine the phosphate-solubilizing capacity of two fungal strains （FC and H3） in various culture media （inorganic or organic phosphorus liquid medium, SP, NBRIY, NBRIP and NBRIYP）. Different types of phosphorus sources （tricalcium phosphate, iron phosphate, aluminum phosphate, dicalcium phosphate and organic phosphorus）, and different concentrations of tricalcium phosphate （0.3, 0.5, 0.7, 0.9 and 1.1%） were used. [Result]Both the strains were found suitable for culturing 5 days in the PDA medium. After culturing for 7 days in different media, FC strains showed the strongest phosphate-solubilizing capacity in NBRIY, followed by inorganic phosphorus medium, NBRIP, organic phosphorus medium and NBRIYP, while H3 strain had the highest phosphate-solubilizing capacity in inorganic phosphorus medium, followed by NBRIP, SP, NBRIY, organic phosphorus medium and NBRIYP. Out of different phosphorus sources, both the FC and H3 strain were found to have strongest phosphate-solubilizing capacity with dicalcium phosphate. Both the strains were found to grow and show phosphate-solubilizing capacity in liquid medium with different concentrations of tricalcium phosphate, which was the highest with 0.5% tricalcium phosphate. [Conclusion]The best culture medium for FC and H3 were identified as NBRIY and inorganic phosphate medium, respectively. Both the 2 strains were able to solublize the insoluble phosphate, however, the strain H3 had higher phosphate-solubilizing capacity.