Zhang Limin, Song Ziwei, Guo Jingyuan, Liu Wenjia, Li Jie, Meng Qingxin, Mo Jixian
College of Life Science and Agriculture and Forestry, Qiqihar University, Qiqihar, 161006, China.
Appl Biochem Biotechnol. 2025 Apr;197(4):2417-2436. doi: 10.1007/s12010-024-05154-4. Epub 2025 Jan 2.
Phosphorus in soil mostly exists in complex compounds such as phytic acid, which reduces the effectiveness of phosphorus and limits agricultural production. Phytase has the activity of hydrolyzing phytate into phosphate. The mineralization of phytate in soil by phytase secreted by microorganisms is an effective way to improve the utilization rate of phytate. This study isolated a high-yield phytase strain, identified as Pseudomonas by 16S rDNA and named Pseudomonas sp. S3-10. The fermentation medium composition and conditions were optimized using the single-factor method, Plackett-Burman design (PBD), and response surface methodology (RSM). The results showed that cane molasses, MgCl, and temperature significantly affected the fermentation biomass of the bacterium. The optimal fermentation conditions were cane molasses and MgCl concentrations of 61.80 g/L and 5.94 g/L, respectively, at 34.4 °C. Compared with the unoptimized fermentation conditions, the maximum biomass increased by 160.17 ± 6.26% under the optimized fermentation conditions, reaching 9.13 ± 0.09 × 10 CFU/mL. The pot experiment results showed that Pseudomonas sp. S3-10 has a significant promoting effect on soybean growth. The strain increased the fresh weight and length of soybean seedlings by 112.92 ± 28.41% and 74.02 ± 3.24%, respectively, and increased the phytase activity in the soil and available phosphorus concentration in the plant rhizosphere by 388.15 ± 24.24% and 365.05 ± 91.96%, respectively. This study provided a high-yield phytase strain and its optimal fermentation conditions. The bacterium has significant plant growth-promoting effects and can be used as a new type of biological fertilizer, which is of great significance for reducing phosphorus fertilizer usage, improving phosphorus utilization efficiency, and protecting the ecological environment in agricultural production.
土壤中的磷大多以植酸等复合化合物的形式存在，这降低了磷的有效性并限制了农业生产。植酸酶具有将植酸水解为磷酸盐的活性。微生物分泌的植酸酶使土壤中的植酸矿化是提高植酸利用率的有效途径。本研究分离出一株高产植酸酶菌株，通过16S rDNA鉴定为假单胞菌属，并命名为假单胞菌S3-10。采用单因素法、Plackett-Burman设计（PBD）和响应面法（RSM）对发酵培养基组成和条件进行了优化。结果表明，甘蔗糖蜜、MgCl和温度对该菌的发酵生物量有显著影响。最佳发酵条件为甘蔗糖蜜和MgCl浓度分别为61.80 g/L和5.94 g/L，温度为34.4℃。与未优化的发酵条件相比，优化后的发酵条件下最大生物量增加了160.17±6.26%，达到9.13±0.09×10 CFU/mL。盆栽试验结果表明，假单胞菌S3-10对大豆生长有显著促进作用。该菌株使大豆幼苗鲜重和长度分别增加了112.92±28.41%和74.02±3.24%，使土壤中的植酸酶活性和植物根际有效磷浓度分别增加了388.15±24.24%和365.05±91.96%。本研究提供了一株高产植酸酶菌株及其最佳发酵条件。该菌具有显著的促植物生长作用，可作为新型生物肥料，对减少磷肥使用、提高磷利用效率和保护农业生产中的生态环境具有重要意义。
