Due to insufficient amount of soluble phosphate and poor persistence of traditional chemical phosphate fertilizers in agricultural soils, the eco-friendly and sustainable phosphorus sources for crops are urgently required. The efficient phosphate-releasing fungal strain designated y2 was isolated and identified by the internal transcribed spacer of rDNA as Penicillium oxalicum y2. When lecithin, Ca₃(PO₄)₂, or ground phosphate rock were separately used as sole phosphorus source, different phosphate-releasing modes were observed. The strain y2 was able to release as high as 2090 mg/L soluble phosphate within 12 days of incubation with Ca₃(PO₄)₂ as sole phosphorus source. In the culture solution, high concentration of oxalic, citric, and malic acids and high phosphatase activity were detected. The organic acids contributed to solubilizing inorganic phosphate sources, while phosphatase was in charge of the mineralization of organic phosphorus lecithin. Afterwards, the fungus culture was applied to the soil with rape growing. During 50 days of incubation, the soil’s available phosphate concentration increased by three times compared with the control, the dry weight of rape increased by 78.73%, and the root length increased by 38.79%. The results illustrated that P. oxalicum y2 possessed both abilities of solubilizing inorganic phosphorus and mineralizing organic phosphorus, which have great potential application in providing biofertilizer for modern agriculture.

由于传统化学磷肥在农业土壤中可溶性磷含量不足和持久性差，迫切需要生态友好、可持续的作物磷源。高效释放磷酸盐的真菌菌株命名为 y2 被分离并通过 rDNA 的内部转录间隔区鉴定为草酸青霉y2。当分别使用卵磷脂、Ca ₃ (PO ₄ ) ₂或粉状磷矿作为唯一磷源时，观察到不同的磷释放模式。菌株 y2 能够在与 Ca ₃ (PO ₄ ) ₂孵育的 12 天内释放高达 2090 mg/L 的可溶性磷酸盐作为唯一的磷源。在培养液中，检测到高浓度的草酸、柠檬酸和苹果酸以及高磷酸酶活性。有机酸有助于溶解无机磷酸盐源，而磷酸酶负责有机磷卵磷脂的矿化。之后，将真菌培养物施用于油菜生长的土壤。培养50天，土壤有效磷浓度比对照增加3倍，油菜干重增加78.73%，根长增加38.79%。结果表明P . 草酸 y2兼具溶解无机磷和矿化有机磷的能力，在为现代农业提供生物肥料方面具有很大的应用潜力。