Phosphate-solubilizing bacteria (PSB) have been reported to increase phosphate (P) content and plant growth. Their application in agricultural systems is an eco-friendly alternative strategy for limiting negative environmental impact of chemical fertilizers and increasing costs. Therefore, the aim of this study was to isolate and characterize new putative PSB to use as inoculum to enhance plant growth and increase P bioavailability in soil. Sixteen bacteria were isolated from Moroccan oat rhizosphere and were screened for their putative P-solubilization by semi-quantitative agar spot method. The two strains MS1B15 and MS1B13, identified as Streptomyces roseocinereus and Streptomyces natalensis, respectively, showed the maximum phosphate solubilization index (PSI = 1.75 and PSI = 1.63). After quantitative assay to determine phosphate solubilization activity, S. roseocinereus MS1B15 was selected for evaluating its putative plant growth promotion activities including production of siderophores, indole-3-acetic acid (IAA) and amino-cyclopropane-1-carboxylate (ACC) deaminase, nitrogen fixation and antimicrobial activity against soil-borne plant pathogens. Under greenhouse condition, barley plants inoculated with S. roseocinereus MS1B15 significantly increased shoot and ear length as well as available phosphorus in ears and leaves and P and N contents in the soil. Overall results showed that the selected strain S. roseocinereus MS1B15 could represent a potential candidate as biofertilizer to increase plant growth as well as P uptake.

据报道，解磷细菌（PSB）可以增加磷酸盐（P）含量并促进植物生长。它们在农业系统中的应用是一种生态友好的替代策略，可限制化肥对环境的负面影响和增加成本。因此，本研究的目的是分离和表征新的假定 PSB，将其用作接种物以促进植物生长并增加土壤中磷的生物利用度。从摩洛哥燕麦根际分离出 16 种细菌，并通过半定量琼脂斑点法筛选其推定的 P-增溶作用。两个菌株 MS1B15 和 MS1B13，鉴定为玫瑰红链霉菌和纳塔链霉菌分别显示最大磷酸盐溶解指数（PSI = 1.75 和 PSI = 1.63）。经过定量测定以确定磷酸盐溶解活性后，玫瑰红链霉菌选择 MS1B15 来评估其假定的植物生长促进活性，包括产生铁载体、吲哚-3-乙酸 (IAA) 和氨基环丙烷-1-羧酸酯 (ACC) 脱氨酶、固氮和针对土传植物病原体的抗菌活性。在温室条件下，大麦植株接种玫瑰红链霉菌MS1B15显着增加了芽和穗的长度以及穗和叶中的有效磷以及土壤中的P和N含量。总体结果表明，所选菌株玫瑰红链霉菌MS1B15 可以作为生物肥料的潜在候选者，以促进植物生长和磷吸收。