Morphological Characteristics and Proteolytic Ability of Peatland Bacteria in Inhibiting Salmonella Typhi and Escherichia Coli

Abstract

This study aims to determine the characteristics of proteolytic bacteria isolates from peatlands from the Meranti Panam Garden area, Labuhanbatu, North Sumatra and their potential in inhibiting Salmonella typhi and Escherichia coli. The method used is an experimental method on a laboratory scale. The results of the casein hydrolysis test on Skim Milk Agar media were continued with the inhibition test for the growth of Salmonella typhi and Escherichia coli bacteria. The results showed that the proteolytic bacteria isolates of peatlands had colony morphological characteristics of round, irregular, and wavy shape, white and cream colony colors, with Gram test results including Gram positive and Gram negative with stem and coccus shapes. There were 6 proteolytic bacteria in peatlands which were able to produce clear zones in the growth of E. coli bacteria with the largest clear zone found in PSp10 isolate, namely 14.88 mm and the lowest clear zone found in PSp9 isolate, namely 10.1 mm. S.typhi shows that not all bacteria are able to produce clear zones. PSp9 isolate produced the largest clear zone diameter, namely 10.25 mm and PSp8 isolate produced the lowest clear zone, namely 8.50 mm. PSp7 and PSp8 isolates did not have clear zones.