Antimicrobial Activity of Callyspongia sp From Culasi, Antique Against Ice-Ice Promoting Bacteria, Bacillus cereus, Brevundimonas diminuta, and Vibrio alginolyticus

Marc Angelico Elizalde1, Nove Kris Herida1, Marcel Jaudian1 and Harold Mediodia1
1Philippine Science High School Western Visayas Campus – Bito-on, Jaro, Iloilo City 5000, Department of Science and Technology, Philippines


Abstract
Seaweeds are one of the Philippines’ major exports. However, seaweed farms are often damaged by ice-ice, a disease condition that turns the branches of the seaweeds into white, fragile branches that easily come off. Previous studies have shown that Bacillus cereus, Brevundimonas diminuta, and Vibrio alginolyticus are known to be associated with and causes ice-ice disease. Methods known to use other organisms to control or inhibit the bacteria that cause the disease are polyculture cultivation and bioprotection. Callyspongia sp. was concluded to have potential as bioprotector in seaweed cultivation; however, other studies suggest that sponges at different locations may result to different antimicrobial activity due to the different symbionts present in different environments, which are responsible to the production of many chemical compounds. This study tested the antibacterial activity of Callyspongia sp. from Mararison Island, Culasi, Antique against Bacillus cereus, Brevundimonas diminuta, and Vibrio alginolyticus. Callyspongia sp. crude extract was extracted using 200 mL of methanol for every 25 g of Callyspongia sp. Broth dilution test was used and serial dilution was performed to produce an eight-fold concentration. Each bacterium was inoculated into the treated test tubes containing the crude extract and three replicates were used. Data was collected using a spectrophotometer and was analyzed using ANOVA. Results showed that the crude extract had significant effects in the growth of Bacillus cereus and Vibrio alginolyticus especially in 4.8×10-3 g/mL and 4.8×10-4 g/mL concentrations and for Brevundimonas diminuta, extract concentration 4.8×10-3 g/mL significantly inhibited its growth. Results show that Callyspongia sp. has the ability to inhibit the growth of bacteria associated with and causing ice-ice disease and has the potential to be used as a bioprotector in seaweed cultivation.