Hossain Md Saddam, Sharna Afroza Aktar, Sharmin Sumaiya, Tusty Tahrima Arman, Hashem Abu, Sarker Palash Kumar
Microbial Biotechnology Division, National Institute of Biotechnology (NIB), Ganakbari, Ashulia, Savar, Dhaka 1349, Bangladesh.
Microbial Biotechnology Division, National Institute of Biotechnology (NIB), Ganakbari, Ashulia, Savar, Dhaka 1349, Bangladesh.
J Genet Eng Biotechnol. 2025 Sep;23(3):100508. doi: 10.1016/j.jgeb.2025.100508. Epub 2025 May 17.
Microorganisms are a significant source of antimicrobial agents, accounting for over half of the antibiotics used in healthcare today. This study focused on isolating and screening antibacterial microorganisms from soil samples, followed by a genome-based analysis of the most potent isolates. A total of 231 bacterial isolates were obtained from 63 soil samples collected across Dhaka, Sylhet, and Cox's Bazar in Bangladesh. Among these, 51 isolates showed antibacterial activity in primary screening using the perpendicular streak method, while 28 exhibited activity in secondary screening via the agar well diffusion method against Escherichia coli ATCC35218, Staphylococcus aureus ATCC6538, Bacillus pumilus ATCC14884, Klebsiella aerogenes ATCC13048, Salmonella typhimurium ATCC13311, Pseudomonas aeruginosa ATCC9027, Micrococcus luteus ATCC10240, B. cereus ATCC10876, Proteus vulgaris ATCC8427, and B. subtilis ATCC6633. All primary screening positive isolates were identified via 16S rRNA analysis, revealing eight genera: Streptomyces (5), Sinomonas (1), Nocardiopsis (3), Arthrobacter (1), Micrococcus (1), Pseudomonas (27), Microbacterium (1) and Bacillus (6). The top five most promising isolates were identified as Pseudomonas aeruginosa, exhibiting strong antagonistic activity, and underwent whole-genome sequencing. Genome mining revealed multiple biosynthetic gene clusters (BGCs), indicating the production of known and unknown antimicrobial compounds, including Pf-5 pyoverdine, Azotobactin D, Pyochelin, and Pyoverdine SMX-1. This study is the first to combine whole-genome analysis with antibacterial activity assessment, highlighting Pseudomonas aeruginosa as a prolific source of bioactive secondary metabolites.
微生物是抗菌剂的重要来源，占当今医疗保健中使用的抗生素的一半以上。本研究重点从土壤样本中分离和筛选抗菌微生物，随后对最有效的分离株进行基于基因组的分析。从孟加拉国达卡、锡尔赫特和科克斯巴扎尔采集的63份土壤样本中总共获得了231株细菌分离株。其中，51株分离株在使用垂直划线法的初步筛选中表现出抗菌活性，而28株在通过琼脂扩散法对大肠杆菌ATCC35218、金黄色葡萄球菌ATCC6538、短小芽孢杆菌ATCC14884、产气克雷伯菌ATCC13048、鼠伤寒沙门氏菌ATCC13311、铜绿假单胞菌ATCC9027、藤黄微球菌ATCC10240、蜡样芽孢杆菌ATCC10876、普通变形杆菌ATCC8427和枯草芽孢杆菌ATCC6633的二次筛选中表现出活性。所有初步筛选阳性的分离株通过16S rRNA分析进行鉴定，揭示了八个属：链霉菌属（5株）、中华单胞菌属（1株）、诺卡氏菌属（3株）、节杆菌属（1株）、微球菌属（1株）、假单胞菌属（27株）、微杆菌属（1株）和芽孢杆菌属（6株）。最有前景的前五株分离株被鉴定为具有强拮抗活性的铜绿假单胞菌，并进行了全基因组测序。基因组挖掘揭示了多个生物合成基因簇（BGC），表明产生了已知和未知的抗菌化合物，包括Pf-5绿脓菌素、固氮菌素D、绿脓杆菌素和绿脓菌素SMX-1。本研究首次将全基因组分析与抗菌活性评估相结合，突出了铜绿假单胞菌作为生物活性次级代谢产物的丰富来源。
