Thu Le Thi My, Xuan Ly Ngoc Thanh, Nhan Tran Chi, Quang Le Thanh, Trong Nguyen Duc, Thuan Vo Minh, Nguyen Tran Trong Khoi, Nguyen Phan Chi, Thuc Le Vinh, Khuong Nguyen Quoc
Faculty of Crop Science, College of Agriculture, Can Tho University, Can Tho City 900000, Vietnam.
Experiment and Practice Section, An Giang University, Vietnam National University Ho Chi Minh City, Long Xuyen City 880000, Vietnam.
Life (Basel). 2024 Nov 12;14(11):1461. doi: 10.3390/life14111461.
Potassium (K) is immobilized within the clay minerals, making it unavailable for plant use. Therefore, the current study aimed to (i) select isolates of purple nonsulfur bacteria that can dissolve K (K-PNSB) and (ii) evaluate the production of plant-growth-promoting substances by the K-PNSB isolates. The results revealed that from in-dyked alluvial soils in hybrid maize fields, 61 K-PNSB isolates were obtained under the pH 5.50 conditions. The total dissolved K content (K) by the 61 K-PNSB isolates fluctuated from 56.2 to 98.6 mg L. Therein, three isolates, including M-Sl-09, M-So-11, and M-So-14 had K of 48.1-48.8 mg L under aerobic dark condition (ADC) and 47.6-49.7 mg L under microaerobic light condition (MLC). Moreover, these three isolates can also fix nitrogen (19.1-21.5 mg L and 2.64-7.24 mg L), solubilize Ca-P (44.3-46.8 mg L and 0.737-6.965 mg L), produce indole-3-acetic acid (5.34-7.13 and 2.40-3.23 mg L), 5-aminolevulinic acid (1.85-2.39 and 1.53-2.47 mg L), siderophores (1.06-1.52 and 0.92-1.26 mg L), and exopolymeric substances (18.1-18.8 and 52.0-56.0%), respectively, under ADC and MLC. The bacteria were identified according to their 16S rDNA as M-Sl-09, M-So-11, and M-So-14. These potential bacteria should be further investigated as a plant-growth-promoting biofertilizer.
钾（K）被固定在粘土矿物中，无法被植物利用。因此，本研究旨在：（i）筛选能够溶解钾的紫色非硫细菌分离株（K-PNSB）；（ii）评估K-PNSB分离株促进植物生长物质的产生。结果表明，在杂交玉米田的堤坝冲积土中，在pH 5.50条件下获得了61株K-PNSB分离株。61株K-PNSB分离株溶解的钾总量（K）在56.2至98.6 mg/L之间波动。其中，包括M-Sl-09、M-So-11和M-So-14在内的三株分离株，在好氧黑暗条件（ADC）下的钾含量为48.1-48.8 mg/L，在微氧光照条件（MLC）下为47.6-49.7 mg/L。此外，这三株分离株还能固氮（分别为19.1-21.5 mg/L和2.64-7.24 mg/L）、溶解钙磷（分别为44.3-46.8 mg/L和0.737-6.965 mg/L）、产生吲哚-3-乙酸（分别为5.34-7.13和2.40-3.23 mg/L）、5-氨基乙酰丙酸（分别为1.85-2.39和1.53-2.47 mg/L）、铁载体（分别为1.06-1.52和0.92-1.26 mg/L）以及胞外聚合物（分别为18.1-18.8%和52.0-56.0%），分别在ADC和MLC条件下。根据其16S rDNA将这些细菌鉴定为M-Sl-09、M-So-11和M-So-14。这些有潜力的细菌应作为促进植物生长的生物肥料进行进一步研究。
