Salah El-Din Mohamed Walaa, Zaki Dina Fouad Ahmed
Microbiology Department, Central Laboratory for Environmental Quality Monitoring (CLEQM), National Water Research Center (NWRC), Cairo, Egypt E-mail:
Organic Chemistry Department, Central Laboratory for Environmental Quality Monitoring (CLEQM), National Water Research Center (NWRC), Cairo, Egypt.
Water Sci Technol. 2019 Jun;79(12):2310-2317. doi: 10.2166/wst.2019.231.
In wastewater treatment plants the antagonistic activities of actinomycetes could be contributing significantly in microbe-removing mechanisms, which are a combination of different factors. For this purpose, out of 58 actinomycetes isolates from a wastewater treatment plant in Al-Fayoum Governorate, Egypt, only 36 different morphological isolates were selected for further studies. Although 35 isolates (97.23%) were active against one or more of tested bacteria, WD5 isolate had broad-spectrum antagonistic activity against both Gram-negative and Gram-positive tested bacteria. WD5 ethyl acetate extract recorded the highest antibacterial activity against Staphylococcus aureus MTCC 96 (23 mm) and the lowest antibacterial activity against Pseudomonas aeruginosa MTCC 2453 (11 mm). Gas chromatography-mass spectrometry analysis of extract using available NIST (National Institute of Standards and Technology) library data identified seven bioactive compounds: 2-methylbutyl acetate, 3',5'-dinitrobenzoic acid, 1-octadecene, tetradecane, dodecane, docosane, and methylamine,N,N-bis(N.-decyl). Many earlier studies mentioned the antibacterial activity of all above seven compounds. The 16S rRNA sequence of WD5 was recorded in GenBank under the accession number MK491056 and confirmed by comparing it with the known 16S rRNA sequences in GenBank as Streptomyces sp. These results indicated antagonistic activity of actinomycetes in the removal of wastewater-associated bacteria.
在污水处理厂中，放线菌的拮抗活性可能在微生物去除机制中发挥重要作用，而微生物去除机制是多种不同因素的组合。为此，从埃及法尤姆省一家污水处理厂分离出的58株放线菌中，仅选择了36株形态不同的菌株进行进一步研究。虽然35株菌株（97.23%）对一种或多种受试细菌有活性，但WD5菌株对受试的革兰氏阴性菌和革兰氏阳性菌均具有广谱拮抗活性。WD5乙酸乙酯提取物对金黄色葡萄球菌MTCC 96的抗菌活性最高（23毫米），对铜绿假单胞菌MTCC 2453的抗菌活性最低（11毫米）。利用美国国家标准与技术研究院（NIST）的现有库数据对提取物进行气相色谱-质谱分析，鉴定出七种生物活性化合物：乙酸2-甲基丁酯、3',5'-二硝基苯甲酸、1-十八碳烯、十四烷、十二烷、二十二烷和N,N-双（N-癸基）甲胺。许多早期研究都提到了上述七种化合物的抗菌活性。WD5的16S rRNA序列已在GenBank中登录，登录号为MK491056，并通过与GenBank中已知的链霉菌属16S rRNA序列进行比较得到确认。这些结果表明放线菌在去除与废水相关细菌方面具有拮抗活性。
