Isolation and characterization of some exopolysaccharide producing bacteria from cassava peel heaps

Abstract

Eighty (80) bacterial isolates from cassava peel heap samples were tested for their ability to produce biofilm using a modified crystal violet method and the total carbohydrate content of EPSs produced by thirteen (13) strong and medium biofilm formers were determined by the phenol-sulphuric acid method. A significant difference was observed in the carbohydrate values of the EPS produced by the different isolates as compared to the positive control (Staphylococcus epidermidis), which produced 0.67 g/L glucose equivalent of EPS; isolate J47 produced the highest (12.76 g/L) EPS, followed by isolates J1 (10.95 g/L), J18 (10.52 g/L) and isolate J2 (10.37 g/L); the lowest EPS quantity was produced by isolate J30 (0.13 g/L). This disparity in the EPS producing ability of these isolate may be dependent on the strains of bacteria in question, as well as the growth environment. Three of the bacterial isolates obtained belong to the genus Bacillus, one was identified as Lactobacillus plantarum and four of the isolates were Klebsiella pneumoniae. Four isolates produced good EPS quantity, with most of the EPS producers being of the Bacillus genus.