title: Isolation, identification and screening of antimicrobial thermophilic Streptomyces sp. Al-Dhabi-1 isolated from Tharban hot spring, Saudi Arabia.
abstract: The strain Streptomyces sp. Al-Dhabi-1 was isolated from soil sediments collected from Tharban hot spring in the southern west of Saudi Arabia using actinomycetes isolation agar and starch casein agar at 55 °C. Identification of the isolate was done according to morphological, physiological and biochemical characteristics and 16S rRNA sequence similarity as well. 16S rRNA sequence and blast analyses confirmed that the isolate belonging to the genus Streptomyces. The sequence was submitted to GenBank with accession number (KF815080). Ethyl acetate extract of Streptomyces sp. Al-Dhabi-1 showed good antimicrobial activities against tested pathogenic microbes. Minimum inhibitory concentration results showed that the best values were observed against S. agalactiae (<0.039 mg/ml) and Klebsiella pneumonia (0.125 mg/ml). Minimum inhibitory concentration of Al-Dhabi-1 against fungi; Cryptococcus neoformans (0.078 mg/ml), C. albicans (0.156 mg/ml), A. niger (0.625 mg/ml), and T. mentagrophytes (0.156 mg/ml). GC-MS analysis was used for the chemical profile of ethyl acetate extract. Benzeneacetic acid (16.02 %) and acetic acid 2-phenylethyl ester (10.35 %) were the major compounds among 31 substances found the ethyl acetate extract. According to the results of antimicrobial activity against pathogenic microbes, it is clear that the actinomycetes from hot springs with extreme environments are promising source for antimicrobial compounds.
authors.affiliation: Department of Botany and Microbiology, Addiriyah Chair for Environmental Studies, College of Science, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia. naldhabi@ksu.edu.sa.
authors.forename: Naif Abdullah
authors.initials: NA
authors.lastname: Al-Dhabi
authors.affiliation: Department of Botany and Microbiology, Addiriyah Chair for Environmental Studies, College of Science, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia.
authors.forename: Galal Ali
authors.initials: GA
authors.lastname: Esmail
authors.affiliation: Department of Botany and Microbiology, Addiriyah Chair for Environmental Studies, College of Science, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia. avdpandiyan@yahoo.co.in.
authors.forename: Veeramuthu
authors.initials: V
authors.lastname: Duraipandiyan
authors.affiliation: Department of Botany and Microbiology, Addiriyah Chair for Environmental Studies, College of Science, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia.
authors.forename: Mariadhas
authors.initials: M
authors.lastname: Valan Arasu
authors.affiliation: Department of Pharmaceutics, Kayyali Chair for Pharmaceutical Industries, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh, 11451, Saudi Arabia. mbekhet@ksu.edu.sa.
authors.forename: Mounir M
authors.initials: MM
authors.lastname: Salem-Bekhit
mesh_terms: D000898:Antibiosis; D001483:Base Sequence; D002176:Candida albicans / Q000502:physiology; D003455:Cryptococcus neoformans / Q000502:physiology; D016680:Genome, Bacterial; D045482:Hot Springs / Q000382:microbiology*; D064307:Microbiota; D008969:Molecular Sequence Data; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013302:Streptomyces / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism / Q000502:physiology
chemical_list: D012336:RNA, Ribosomal, 16S
keywords: Antimicrobial; GC–MS; Hot springs; Streptomyces sp.; Thermophilic