Bano Naushin, Siddiqui Saba, Amir Mohammad, Zia Qamar, Banawas Saeed, Iqbal Danish
Department of Bioengineering, Integral University, Lucknow 226026, India.
Integral Institute of Agricultural Science and Technology, Integral University, Lucknow 226026, India.
Saudi J Biol Sci. 2022 Mar;29(3):1858-1868. doi: 10.1016/j.sjbs.2021.10.038. Epub 2021 Oct 22.
The study aimed to assess the proficiency of secondary metabolites (SMs) synthesized by actinobacteria isolated from the rhizospheric soil of for its antimicrobial and anti-biofilm activity. After morphological and biochemical identification of actinobacteria, primary and secondary screening was done for specific metabolite production. The secondary metabolites were then tested for their antioxidant, antibacterial, and antibiofilm potential. Out of 29 bacterial colonies isolated, only one emerged as a novel isolate, LA2(R). Partial 16S rRNA gene sequence of the isolate LA2(R) was deposited in NCBI GenBank with accession number MN560041. The highest antioxidant capacity of the methanolic extract the novel isolate was found to be 474.183 µL AAE/mL and 319.037 µL AAE/mL by DPPH assay and ABTS assay respectively; three folds higher than the control. These results were further supported by the high total phenolic (194.95 gallic acid equivalents/mL) and flavonoid contents (332.79 µL quercetin equivalents/mL) of the methanolic extract. GC-MS analysis revealed the abundance of antibacterial compounds; where, n-Hexadecanoic acid was found to be the major compound present with a peak of 14 min retention time (RT) and 95% similarity index. MIC value of the metabolite was noted to be around 132.28 ± 84.48 μg/mL. The IC value was found to be 74.37, 71.33, 66.28 and 84.48 μg/mL against , , , and , respectively. Treatment with IC of the extract decreased the biofilm formation up to 70%-80% against pathogenic strains viz. , , and . These significant activities of sp. LA2(R) suggests that it could be utilized for antibiotic production for human welfare and in various important industrial applications.
本研究旨在评估从[植物名称]根际土壤中分离出的放线菌合成的次生代谢产物（SMs）的抗菌和抗生物膜活性。在对放线菌进行形态学和生化鉴定后，针对特定代谢产物的产生进行了初筛和复筛。然后对次生代谢产物的抗氧化、抗菌和抗生物膜潜力进行了测试。在分离出的29个细菌菌落中，只有一个被鉴定为新型菌株LA2(R)。该菌株LA2(R)的部分16S rRNA基因序列已存入NCBI基因库，登录号为MN560041。通过DPPH法和ABTS法分别测定，该新型菌株甲醇提取物的最高抗氧化能力分别为474.183 μL AAE/mL和319.037 μL AAE/mL，比对照高三倍。甲醇提取物中高含量的总酚（194.95没食子酸当量/mL）和黄酮类化合物（332.79 μL槲皮素当量/mL）进一步支持了这些结果。气相色谱-质谱联用（GC-MS）分析显示存在大量抗菌化合物；其中，正十六烷酸被发现是主要化合物，保留时间（RT）为14分钟，相似度指数为95%。该代谢产物的最低抑菌浓度（MIC）值约为132.28±84.48 μg/mL。发现其对[细菌名称1]、[细菌名称2]、[细菌名称3]和[细菌名称4]的半数抑制浓度（IC）值分别为74.37、71.33、66.28和84.48 μg/mL。用提取物的IC处理可使针对致病菌株[细菌名称1]、[细菌名称2]、[细菌名称3]和[细菌名称4]的生物膜形成减少70%-80%。LA2(R)菌株的这些显著活性表明，它可用于生产造福人类的抗生素以及各种重要的工业应用。
