Nandhagopal Manivannan, Chandrasekaran Ramprasath, Narayanasamy Mathivanan
Centre for Advanced Studies in Botany, University of Madras, Guindy Campus, Chennai 600025, India.
Department of Microbiology, Saveetha Medical College & Hospital, Saveetha Institute of Medical and Technical Sciences (SIMATS), Thandalam, Chennai 602105, India.
J Appl Microbiol. 2023 Dec 1;134(12). doi: 10.1093/jambio/lxad286.
The present study aims to determine the antimicrobial potential of Virgibacillus salairus (MML1918) against human pathogens and its in-vitro and in-silico properties.
In this present study, totally 63 halophilic bacterial cultures were obtained and cultivated in nutrient broth medium containing 8% NaCl and the metabolites, were extracted using ethyl acetate and screened for their antimicrobial property by cell viability assay against 12 pathogenic bacteria and fungi, among 63 halophilic bacteria the Vir. salaries (MML1918) found to be the best producer for secondary metabolites production against clinical pathogens. The optimization of growth for important physiochemical parameters was characterized and applied for different production media and based on its highest activity as 17.5 ± .07 mm zone of inhibition (ZOI) for Bacillus cereus followed by 17.5 ± 00 mm ZOI for Staphylococcus aureus, the production medium ATCC1097 was chosen for mass production. The mass production of secondary metabolites from Vir. salaries MML1918 was carried out in a fermenter under controlled conditions and crude metabolites was extracted and condensed. The antimicrobial activity of crude metabolites showed B. cereus (19.3 ± 0.5 mm ZOI), Staph. aureus, and Candida albicans (18.3 ± 0.5 mm ZOI) as the highest ZOI in production media for halophilic bacteria ATCC1097. Further, the gas chromatography-mass spectrometry analysis showed 24 compounds present in crude metabolites. Among the 24 compounds, four molecules were found to be important based on molecule percentage in crude and structural similarity. The molecular docking studies show that the selected four molecules effectively bind with the active region DNA gyrase B.
Virgibacillus salarius (MML1918) effectively showed antimicrobial activity against several pathogenic organisms and can be employed as a suitable candidate for producing novel antimicrobial agents.
本研究旨在确定盐沼维尔吉芽孢杆菌（MML1918）对人类病原体的抗菌潜力及其体外和计算机模拟特性。
在本研究中，共获得63株嗜盐细菌培养物，并在含有8%氯化钠的营养肉汤培养基中培养，其代谢产物用乙酸乙酯提取，并通过针对12种病原菌和真菌的细胞活力测定法筛选其抗菌性能。在63株嗜盐细菌中，盐沼维尔吉芽孢杆菌（MML1918）被发现是针对临床病原体产生次级代谢产物的最佳菌株。对重要理化参数的生长优化进行了表征，并应用于不同的生产培养基，基于其对蜡样芽孢杆菌的最高活性为17.5±0.07毫米抑菌圈（ZOI），其次对金黄色葡萄球菌的抑菌圈为17.5±0.00毫米，选择ATCC1097生产培养基进行大规模生产。在可控条件下，在发酵罐中对盐沼维尔吉芽孢杆菌MML1918的次级代谢产物进行大规模生产，并提取和浓缩粗代谢产物。粗代谢产物的抗菌活性显示，在嗜盐细菌ATCC1097的生产培养基中，蜡样芽孢杆菌（抑菌圈为19.3±0.5毫米）、金黄色葡萄球菌和白色念珠菌（抑菌圈为18.3±0.5毫米）的抑菌圈最大。此外，气相色谱-质谱分析显示粗代谢产物中存在24种化合物。在这24种化合物中，基于其在粗产物中的分子百分比和结构相似性，发现有4种分子很重要。分子对接研究表明，所选的4种分子能有效地与活性区域DNA促旋酶B结合。
盐沼维尔吉芽孢杆菌（MML1918）对多种致病生物有效显示出抗菌活性，可作为生产新型抗菌剂的合适候选菌株。
