POTENTIAL OF MICROALGAE AS AN ALTERNATIVE FOR PREVENTION OF VIBRIOSIS

Ince Ayu K.Kadriah*, Sahabuddin and Nurbaya
Research Institute for Coastal Aquaculture
Jl. Makmur Dg. Sitakka No. 129.Maros 90511, South Sulawesi
E-mail: inceayu@gmail.com
 

Aquaculture is a rapidly growing food sector in the world. However, infectious disease caused by pathogens either viruses or bacteria dramatically reduces the productivity of aquaculture and has obstructed economic development in many countries. Pathogenicity of microorganisms that infect in aquaculture system is closely related to the release of factors regulated by quorum sensing (QS). Vibrio bacteria use an Acyl Homoserine Lactone (AHL) compound for quorum sensing signal. QS inhibition is a potential therapeutic target, where the inhibition of bacterial cell communication could be a promising strategy to suppress bacterial virulence.

This study was aimed to determine the potential of coastal and marine microalgae as an alternative material for the prevention of vibriosis through the method of inhibition of quorum sensing signal. This research was conducted in the Laboratory of Fish Health and Environment,  Research Institute for Coastal Aquaculture (BPPBAP, Balai Penelitian dan Pengembangan Budidaya Air Payau). In this study, 10 types of microalgae obtained from P2O LIPI, BBAP Situbondo and BBPPBL Gondol were used. Furthermore, we succeeded in performing isolation of 3 types of microalgae from Losari Coastal Area, Lae-Lae Island and Coastal Area of Barru Regency. Screening of microalgae producing metabolites of Anti Quorum Sensing (AQS) was conducted in several stages, started from the isolation of supernatant through centrifugation method which was followed by metabolites extraction using Ethyl Acetate solvent. Later, evaporation was performed to evaporate the solvent. The extract was dissolved again with sterile aquades. Once the microalgae extract was obtained, bioassay test with disc diffusion method using biosensor of Chromobacterium violaceum bacteria as a marker of anti QS on LB media was performed. QS inhibition was detected by the presence of a clear ring around disc paper by microalgae which produce AQS degrading AHL.

Based on the result of bioassay test, five types of microalgae which were positive to have the ability to inhibit Quorum sensing signal were found, namely: Melosira, Porpyridium, Vulgaris, Phaeodactylum and Nannochloropsis. Keywords: Quorum Sensing, Microalgae, Vibriosis, Acyl Homoserine Lactone