SCREENING FOR ANTIMICROBIAL POTENCY IN AQUATIC BACTERIA (Labrenzia aggregata, Bacillus siamensis, dan Halomonas alkaliphila)

• Main Author: Hidayah Priyanto, Nurul
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/42896
• Institution: Institut Teknologi Bandung

Aquaculture is a sector that give contribution to aquatic animal production for domestic consumption and for export comodity. One of many problems faced by aquaculture farmers are infection deseases affecting aquatic animals caused by pathogens such as Vibrio spp., Staphylococcus aureus, Pseudomonas spp., Shewanella spp. etc. that result in mortality of adult animal, larve, or juvenile and resulting in field decrease. Upon the spread of infectious desease there need to be alternatives to solves the problems. Several aquatic bacteria such as Labrenzia agregata, Bacillus siamensis, and Halomonas alkaliphila could be used to conduct environmental control by using those bacteria as probiotic and control agent with their antimicrobial activity. First, preliminary test conducted using Kirby Bauer for antimicrobial filtrate from Labrenzia agregata, Bacillus siamensis, and Halomonas alkaliphila (innitial innoculum 108 CFU/mL) in 37ºC in 48 hours against gram negative bacteria (Vibrio alginolyticus, Pseudomonas aeruginosa, dan Shewanella amazonensis) and gram positive bacteria (Bacillus subtilis and staphylococcus aureus). After preliminary test, MIC (minimum inhibitory concentration) was conducted to bacteria that had antimicrobial potency using microdulution broth method with innitial innoculum is 5% (104 CFU/mL) then compared to 10 ?g/?L streptomycin. Next test conducted to bacteria which had microbial potency from age of 4 hours to 48 hours using the same method as preliminary test. Based on preliminary result, Labrenzia agregata has higher potency than other bacteria shown by clear zone on media surface against gram negative (S. amazonensis) and gram positive bacteria (B. subtilis) with diameter respectedly 0,8 dan 0,825 cm long. MIC test to gram negative bacteria V. alginolyticus shows that MIC endpoint is in two-fold dilution of filtrate with microbial activity is equal to streptomycin 0,04 ?g/?L meanwhile the filtrate microbial activity is equal to streptomycin 5,028 ?g/?L. MIC test to P. aeruginosa and S. amazonensis shows that microbial activity is equal to streptomycin 1,53 ?g/?L and 2,31 ?g/?L respectively. Result from diffusion test Kirby Bauer from 4-48 hours incubated bacteria shows that highest antimicrobial activity was from 48 hours incubated bacteria tested against S. amazonensis dan B. subtilis with average of diameter is 0,9 cm and 0,92 cm respectively and no result shown from test against P. aeruginosa dan V. alginolyticus. Based on result from the tests, L. Aggregata have potency as a probiotic as this bacteria can produce antimicrobial compound and has antiicrobial potency against some microbes.