Nxumalo Celiwe Innocentia, Ngidi Londeka Sibusisiwe, Shandu Jabulani Siyabonga Emmanuel, Maliehe Tsolanku Sidney
Faculty of Science and Agriculture, Department of Biochemistry and Microbiology, University of Zululand, Private Bag X1001, KwaDlangezwa, KwaZulu Natal Province, 3886, South Africa.
BMC Complement Med Ther. 2020 Oct 7;20(1):300. doi: 10.1186/s12906-020-03095-z.
Endophytes, especially those that are found from ethnopharmacologically noteworthy medicinal plants have attracted attention due to their diverse bioactive metabolites of pharmacological importance.
This study aimed at isolating endophytic bacterium from the leaves of Anredera cordifolia CIX1 for its bioactive metabolites. The endophytic isolates were identified by 16S rRNA sequence and investigated for antibiotic sensitivity using different antibiotics. The secondary metabolites were evaluated for antibacterial activity against four bacterial strains. The 2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2'-azinobis (3- ethylbenzothiazoline-6-sulfonic acid) (ABTS) methods were used to assess their scavenging activities. The chemical components were analysed by gas chromatography-mass spectrometry (GC-MS).
Out of 13 isolates, Isolate 1 was identified as Pseudomonas aeruginosa CP043328.1. It was resistant to clindamycin, ertapenem, penicillin G, amoxicillin, cephalothin and kanamycin but sensitive to imipenem, meropenem, and gentamycin. Its extract demonstrated antibacterial activity with minimum inhibitory concentration value of 0.098 against Bacillus cereus (ATCC 10102) and Staphylococcus aureus (ATCC 25925) and 0.391 mg/ml against Escherichia coli (ATCC 25922) and Proteus mirabilis (ATCC 25933). The extract revealed DPPH and ABTS scavenging activities with half maximal inhibitory concentration value of 0.650 mg/ml and 0.15 mg/ml, respectively. The GC-MS revealed a total of 15 compounds with diisooctyl phthalate (50.51%) and [1, 2, 4] oxadiazole, 5-benzyl-3 (10.44%) as major components.
P. aeruginosa CP043328.1 produced secondary metabolites with antibacterial and antioxidant activities.
内生菌，尤其是那些从具有民族药理学意义的药用植物中发现的内生菌，因其具有多种具有药理学重要性的生物活性代谢产物而受到关注。
本研究旨在从落葵薯CIX1的叶片中分离内生细菌以获取其生物活性代谢产物。通过16S rRNA序列鉴定内生分离株，并使用不同抗生素研究其抗生素敏感性。评估次生代谢产物对四种细菌菌株的抗菌活性。采用2-二苯基-1-苦基肼（DPPH）和2,2'-偶氮二（3-乙基苯并噻唑啉-6-磺酸）（ABTS）方法评估其清除活性。通过气相色谱-质谱联用（GC-MS）分析化学成分。
在13株分离株中，分离株1被鉴定为铜绿假单胞菌CP043328.1。它对克林霉素、厄他培南、青霉素G、阿莫西林、头孢噻吩和卡那霉素耐药，但对亚胺培南、美罗培南和庆大霉素敏感。其提取物表现出抗菌活性，对蜡样芽孢杆菌（ATCC 10102）和金黄色葡萄球菌（ATCC 25925）的最低抑菌浓度值为0.098，对大肠杆菌（ATCC 25922）和奇异变形杆菌（ATCC 25933）的最低抑菌浓度值为0.391mg/ml。提取物显示出DPPH和ABTS清除活性，半数最大抑制浓度值分别为0.650mg/ml和0.15mg/ml。GC-MS共鉴定出15种化合物，其中邻苯二甲酸二异辛酯（50.51%）和5-苄基-3-[1,2,4]恶二唑（10.44%）为主要成分。
铜绿假单胞菌CP043328.1产生具有抗菌和抗氧化活性的次生代谢产物。
