title: A Comparative biochemical study on two marine endophytes, Bacterium SRCnm and Bacillus sp. JS, Isolated from red sea algae.
abstract: Two marine endophytic bacteria were isolated from the Red Sea algae; a red alga; Acanthophora dendroides and the brown alga Sargassum sabrepandum. The isolates were identified based on their 16SrRNA sequences as Bacterium SRCnm and Bacillus sp. JS. The objective of this study was to investigate the potential anti-microbial and antioxidant activities of the extracts of the isolated bacteria grown in different nutrient conditions. Compared to amoxicillin (25μg/disk) and erythromycin (15μg/disk), the extracts of Bacterium SRCn min media II, III, IV and V were potent inhibitors of the gram-positive bacterium Sarcina maxima even at low concentrations. Also, the multidrug resistant Staphylococcus aureus(MRSA) was more sensitive to the metabolites produced in medium (II) of the same endophyte than erythromycin (15μg/disk). A moderate activity of the Bacillus sp. JS extracts of media I and II was obtained against the same pathogen. The total compounds (500ug/ml) of both isolated endophytes showed moderate antioxidant activities (48.9% and 46.1%, respectively). LC/MS analysis of the bacterial extracts was carried out to investigate the likely natural products produced. Cyclo(D-cis-Hyp-L-Leu), dihydrosphingosine and 2-Amino-1,3-hexadecanediol were identified in the fermentation medium of Bacterium SRCnm, whereas cyclo (D-Pro-L-Tyr) and cyclo (L-Leu-L-Pro) were the suggested compounds of Bacillus sp. JS.
authors.affiliation: Department of Chemistry of Natural and Microbial Products, National Research Centre, Dokki, Cairo, Egypt.
authors.forename: Eman Fadl
authors.initials: EF
authors.lastname: Ahmed
authors.affiliation: Department of Pharmacognosy, College of Pharmacy, Beni-Suief University, Egypt.
authors.forename: Hossam Mokhtar
authors.initials: HM
authors.lastname: Hassan
authors.affiliation: Department of Pharmacognosy, College of Pharmacy, Beni-Suief University, Egypt / Marine Biodiscovery Centre, University of Aberdeen, AB24 3UE Scotland, UK.
authors.forename: Mostafa Ezzat
authors.initials: ME
authors.lastname: Rateb
authors.affiliation: Department of Botany, faculty of Science, Beni-Suief University, Egypt.
authors.forename: Noha
authors.initials: N
authors.lastname: Abdel-Wahab
authors.affiliation: Marine Biodiscovery Centre, University of Aberdeen, AB24 3UE Scotland, UK.
authors.forename: Somayah
authors.initials: S
authors.lastname: Sameer
authors.affiliation: Department of Plant Biochemistry-National Research Centre, Dokki, Cairo, Egypt.
authors.forename: Hanan Anwar
authors.initials: HA
authors.lastname: Aly Taie
authors.affiliation: Department of Botany, faculty of Science, Beni-Suief University, Egypt.
authors.forename: Mohammed Sayed
authors.initials: MS
authors.lastname: Abdel-Hameed
authors.affiliation: Department of Botany, faculty of Science, Beni-Suief University, Egypt.
authors.forename: Ola
authors.initials: O
authors.lastname: Hammouda
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology; D001407:Bacillus / Q000254:growth & development / Q000378:metabolism*; D060026:Endophytes / Q000254:growth & development / Q000378:metabolism*; D005285:Fermentation; D000461:Rhodophyta / Q000382:microbiology*; D013696:Temperature; D014871:Water Microbiology
chemical_list: D000890:Anti-Infective Agents; D000975:Antioxidants