Isolation of Haematococcus lacustris as source of novel anti-multi-antibiotic resistant microbes agents; fractionation and identification of bioactive compounds

In this work, freshwater microalga, Haematococcus lacustris was isolated from the River Nile, identified and deposited in genebank under name of H. lacustris isolate REH10 with accession number OK336515. N-hexane extract was produced high inhibition effects against multi-antibiotic resistant pathogens. The n-Hexane extract was fractionated and 2 fractions (F3 & F4) exhibited high antibacterial activity (15 – 20 mm) compared with other fractions. Thus, they sub-fractionated and 2 sub-fractions produced from the F3 had high inhibition activity against all tested pathogens (18–20 mm). To identify the main compounds responsible for inhibition growth of multi-drug resistance bacteria, GC–MS chromatogram analyses was applied on the F3 and its sub-fractions 2 and 3. Five compounds detected in the 2 sub-fractions. Palmitic acid was identified as the first report antibacterial agent. The antioxidant activity of SF3–3 was reached to 86 and 80.5% for DPPH and ABTS.(+) tests, respectively.