Effects of green algae, Chlorella Vulgaris, extracts and its bioactive substances on the biofilm-producing microorganism

Abstract

The current study aims at the in-vitro use of 2 types of extracts of Chlorella Vulgaris, one of the most widely known green algae species in the world, to evaluate their effects on biofilm-producing bacteria. In this study, 7 species of algae were isolated from different environments and then diagnosed according to the sources of green algae and greenish algae. Some of these isolates  were  proliferated under constant laboratory conditions at 25±2 ̊C, 200μm/m2/sec, and 8:16 hours of light: dark using fixed farms. Then, these species were subjected to 2 types of polycarbonate-based solvents (hexane and chloroform). These extracts were tested on E.Coli, Klebsiella, Acinetobacter, Serratia mesccens, St epidermis, S. aureus, Candida albicans, and Aspergills niger. Using different methods of measuring turbidity of the red agar, micrometer plate, spreading Balacar, the effects of these extracts were examined on these microorganisms. Then, the algae were subjected to vertical chromatography to separate active substances. The hexane-based extract was more effective against E. coli, Acinetobacter, St. aureus. On the other hand, the chloroform-based extract showed slight effects on Acinetobacter and C. albicans. The best inhibitory activities were 30mm for Staphylococcus aureus and Serratia and 25mm for E. coli. The lowest inhibition activity was 15mm for Klebsiella and C. albicans. For the chloroform-based extract, the highest rate of inhibition was 20mm for Klebsiella and S. aureus. The lowest inhibition was 10mm for Acinetobacter and C. albicans. Separation method targeted the hexane-based extraction yielded hxan, gasoline group III ethyl estate, gasoline, group IV ethyl ester, methanol group, and methanol. The hexane + 25 ml of benzene and the fourth group of ethyl ester 25 + methanol showed higher inhibition activities against microbes than that using the other three groups. The hexane-based extracts and the related hexane + 25 ml of benzene and the fourth group of ethyl ester 25 + methanol of C. vulgaris were better than the chloroform-based extracts in their effectiveness against the studied microbes using the turbidity measurement method.