Active and phenolic compounds in Spirogyra sp. PDNA1 is an antibiotic for some bacteria and fungi

Green algae are a biological source rich in phenolic compounds and potentially inhibit the growth of microorganisms. Spirogyra sp. PDNA1 is one of the most types of green algae found in freshwater. Because of the increasing resistance of most bacteria and fungi to available antibiotics, a continuous search is required for the most effective, economical, and environmentally friendly alternatives. There are 30 compounds were identified, including alkaloids, phenols, and esters, and the highest percentage was oleic acid, with a retention time of 21.949 min and a concentration of 32.89%. The highest percentage of inhibition showed on the bacteria for the methanolic algal extract was against Salmonella typhi (22.5 mm), while the lowest percentage of it was against Bacillus cereus (10 mm). The hexane extract had the highest inhibition percentage against Salmonella typhi (19.5 mm) and the lowest inhibition percentage against Klebsiella pneumoniae (11 mm). It was also noted that the effect of the methanolic extract was highest against Trichoderma asperallum (22 mm) and the lowest percentage of inhibition against Candida albicans (7 mm), while the hexane extract recorded the highest percentage of inhibition against Candida albicans (15 mm) and the lowest percentage of inhibition was against the fungus Aspergillus Niger with inhibition diameter (8 mm). Phenols were identified by HPLC technology. The phenolic compounds included Rutin, Gallic acid, Tannic acid, Quercetin, and Kaempferol, where the highest percentage of Rutin was in the phenolic methanolic extract (240.99) ppm, Kaempferol (7.2124) ppm, while the phenolic hexane extract had the highest percentage of Rutin (19.606) ppm, Kaempferol (10.997) ppm. The phenols showed the highest inhibition rate of the phenolic-methanolic extract against (Klebsiella pneumoniae) (30) mm and the least inhibition against (Escherichia. coli) (11) mm while the phenolic hexane extract has the highest inhibition to (Salmonella typhi) (27) mm and the lowest effect was against (Escherichia coli) (10) mm. The antifungal effect of the phenolic methanolic extract recorded the highest percentage against (Candida albicans) (30) mm and had the lowest effect on Mucor racemosus (18) mm, while the phenolic hexane extract had the highest effect with Candida albicans (22.5) mm, and the least inhibition percentage was in Mucor racemosus with (11) mm. Therefore, the study aimed to isolate and identify the effective compounds of the methanolic and hexanoic extract of this algae, and active phenolic compounds were detected using GC-MS and HPLC technology.