Volatile Compounds, Fatty Acids Constituents, and Antimicrobial Activity of Cultured Spirulina () Isolated from Lake Mariout in Egypt.

In this study, previously isolated from Lake Mariout (Alexandria, Egypt) was cultivated in the laboratory using a medium for pharmaceutical grade , named as Amara and Steinbüchel medium. Hot water extract of the Egyptian was prepared by autoclaving dried biomass in distilled water at 121°C for 15 min. This algal water extract was analyzed by GC-MS to evaluate its volatile compounds and fatty acids composition. The antimicrobial activity of phycobiliprotein extract from using phosphate buffer was evaluated against thirteen microbial strains (two Gram-positive bacteria, eight Gram-negative bacteria, one yeast, and two filamentous fungi). The major components of fatty acids in the hot extract of Egyptian were hexadecanoic acid (palmitic acid, 55.19%) and octadecanoic acid (stearic acid, 27.14%). The main constituents of its volatile compounds were acetic acid (43.33%) and oxalic acid (47.98%). The most potent antimicrobial effect of phycobiliprotein extract was obtained against two Gram-negative bacteria and , filamentous fungus , and the pathogenic yeast (all of which showed MIC values of 58.1 g/ml). and come second in their susceptibility to the phycobiliprotein extract from and and are the least in susceptibility, with MIC values of 116.2 and 232.5 g/ml, respectively, while phycobiliprotein extract has no antibacterial effect on methicillin-resistant as well as susceptible , , , and . These findings confirmed the nutritional value of Egyptian isolated from Lake Mariout and suggest the potential use of this strain as an ingredient in the cooking of some foods to increase the level of stearic acid and palmitic acid. Moreover, its effective antibacterial activities against some important and highly resistant to antibiotics bacterial pathogens in addition to its antifungal effects recommend the therapeutic use of its biomass.