Gina-Ager Comprehensive Secondary School, North Shewa Zone Amhara National Regional State, Ethiopia.
Department of Plant Science, College of Agriculture and Natural Resource Science, Debre Berhan University, Debre Berhan, Ethiopia.
PLoS One. 2024 Nov 15;19(11):e0308915. doi: 10.1371/journal.pone.0308915. eCollection 2024.
Phosphorus plays a crucial role in regulating many of the plant's metabolic activities by enhancing physiological functions and stimulating biological activities such as nodulation, nitrogen fixation, and nutrient uptake in the soil rhizosphere environment. Inoculants of phosphorus solubilizing bacteria serve as an eco-friendly alternative technology that positively influences both soil sustainability and plant growth. The majority of North Shewa highland areas are characterized by low available phosphorus, primarily acidic, and exhibit strong phosphorus absorption. The objective of this study was to isolate and identify phosphorus solubilizing bacteria from the rhizosphere of lentils and characterize their phosphate solubilizing activity. The cultural, biochemical, physiological microbial analysis was conducted in the microbiology laboratory, department of biology. Pikovskaya's medium was utilized for the isolation, screening, and maintenance of phosphate solubilizing bacteria. Phosphate Solubilizing Bacteria were isolated using tri-calcium phosphate as the sole source of phosphorus in indicator plates. Fifteen phosphate solubilizing bacteria were isolated from lentil rhizosphere soil samples, among which six were the most efficient phosphate solubilizers designated as PSBYE, PSBYR, PSBYM, PSBYL, PSBW, and PSBSW. All isolates notably solubilized tri-calcium phosphate compared to the uninoculated control. The highest phosphorous solubilization was observed from the isolate PSBYL, with a value of 10.61mg/50ml, followed by PSBW with a value of 9.08 mg/50ml. The decrease in pH value correlated with the levels of tri-phosphate solubilization in the PVK broth by the PSB isolates. The pH dropped to 4.64 from the initial pH of 7.2 when grown in the broth, which suggests that the production of organic acids is likely the primary mechanism for phosphate solubilization.
磷通过增强生理功能和刺激生物活性（如根际环境中的结瘤、固氮和养分吸收），在调节植物的许多代谢活动中起着至关重要的作用。解磷细菌接种剂是一种环保的替代技术，它对土壤的可持续性和植物的生长都有积极的影响。北舍瓦高原地区的大部分地区都存在有效磷含量低、主要呈酸性和磷吸收能力强的特点。本研究的目的是从兵豆根际中分离和鉴定解磷细菌，并对其溶磷活性进行表征。文化、生化、生理微生物分析在生物学系的微生物实验室进行。利用 Pikovskaya 培养基进行解磷细菌的分离、筛选和保存。利用磷酸三钙作为指示平板中的唯一磷源来分离和筛选溶磷细菌。从兵豆根际土壤样品中分离出 15 株溶磷细菌，其中 6 株为溶磷效率最高的菌，分别命名为 PSBYE、PSBYR、PSBYM、PSBYL、PSBW 和 PSBSW。与未接种对照相比，所有分离株均能显著溶解磷酸三钙。溶磷效果最好的是 PSBYL 菌株，其溶磷值为 10.61mg/50ml，其次是 PSBW 菌株，其溶磷值为 9.08mg/50ml。PSB 分离株在 PVK 肉汤中对三磷酸盐的溶解与 pH 值的降低呈正相关。当在培养液中生长时，pH 值从初始的 7.2 降至 4.64，这表明有机酸的产生可能是溶磷的主要机制。
