Nehad M. Abd El Moneam1, Samy A. Al-Assar2,
Mohamed A. Sheradahand Asmaa Nabil-Adam3*

1Biochemistry Department, Faculty of Science, Alexandria University, Alexandria, Egypt.
2Botany and Microbiology Department, Faculty of Science, Alexandria University, Alexandria, Egypt.
3Marine Biotechnology and Natural products Lab (MBNP). National Institute of Oceanography & Fisheries (NIOF) ,Alexandria, Egypt.


Marine coastal areas of the Red sea in Egypt have great biodiversity of sponges which harbors a huge number of endosymbiotic bacteria which are the source of many potential bioactive metabolites and consider as an excellent source. The study focuses on the isolation of Pseudomonas sp associated with marine sponge Hyrtios aff. Erectus from the Red Sea in pure culture, phylogenetically identified and screening of their metabolic pathways polyketide synthases and Nonribosomal peptides (PSK and NRPs). Characterization of the bacterial produced bioactive metabolite was done through antioxidant and cytotoxicity assays using DPPH and cell line. The 16S rRNA gene sequencing of bacterial isolate revealed that the bacterial strain was closely related to Pseudomonas sp., and the active metabolic pathways genes in the Pseudomonas sp was PSK II. The antioxidants and cytotoxicity bioactivity of Pseudomonas sp as is most probably related to the presence of associated bioactive metabolic pathways genes related to polyketides family type II. Furthermore, the antioxidant activity of Pesudomance sp extract, performed by quantification of total phenolic content (TPC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity antioxidant activities, were evaluated. The highest antioxidant activity was exhibited at different concentrations (50 mg-6.25 mg) which showed a potent antioxidant capacity by 100% at 50mg, 25 mg and 12.25 mg. From the cytotoxicity, antioxidant and bioactive metabolic screening pathways this bacterial strain was revealed to be an excellent source of natural antioxidant and cytotoxicity compounds against free radical and cancerous cell line.

Keywords: Pseudomonas sp., Metabolic Pathways NRPs and PKS, Hyrtios aff. Erectus Sponge extract.