Pengaruh Optimasi Waktu Fermentasi dan Kontrol pH pada Aktivitas Antimikroba Actinomycetes terhadap Salmonella typhi

Abstract

Actinomycetes are Gram positive bacteria, long rod-shaped, and can be used as antimicrobials because they can produce secondary metabolite compounds. Factors affecting the production of such compounds are fermentation time and pH. Salmonella typhi is a pathogenic bacterium that causes typhoid fever. This study aims to determine the duration of optimization of fermentation of Actinomycetes isolates with pH control on the growth of Salmonella typhi bacteria in Vitro. The types and research designs used are true experimental studies and Complete Randomized Design (RAL). Starch Casein Agar (SCA) media was used to culture Actinomycetes isolates and then fermented on media containing mannitol 2%, peptone 2%, and glucose 1% and incubated for 1, 2 and 3 days. The antimicrobial activity test method uses the well method on Nutrient Agar (NA) media. Actinomycetes bacteria with fermentation duration of 1, 2 and 3 days accompanied by pH control were able to inhibit the growth of Salmonella typhi bacteria with an average inhibitory zone formed of 13.70 mm; 15.41 mm and 15.09 mm. Wallis's Kruskal test showed significant differences in inhibitory zones in each treatment group. The 2nd day fermentation group had the greatest antimicrobial effectiveness with an average inhibition zone value of 15.41 mm