STUDIES ON THE UTILIZATION OF SOME MICROORGANISMS AS DIETARY ADJUNCTS UNDER LOCAL CONDITIONS

Abstract

Utilization of probiotic microorganisms as dietru y1 adjuncts is now receiving a worldwide attention . Therefore, the pre1 nt study focused on investigation and optimisation of a process forV preparation of a similar combination from locally isolated and identified microbial candidates that have probiotic characteristics. So that, several topics were studied, t.e, isolation and identification of Lactobacillus

acidophilus,

Bifidobacterium b(fidum, B. infantis and Enterococcus

faeCium from local

sources; selection for the best probiotic strains;

utilization • of

permeate based medium for production of probiotic

cultures;

optimization of a laboratory scale process for biomass

production of the yoghurt using

selected strains and manufacturing of probiotic

Depending on the collected samples which have been taken from local sources, i.e. goat milk, infant faeces, and Ras cheese, the obtained results indicated that twelve thetmobacterium strains could be isolated from goat milk, 7 (58.3%) were identified as Lactobacillus acidophilus,

3 (25%) as L.

bulgaricus and 2 (16.6%) as L. fermentium. As for

Bifidobacterium isolates, out of 101 isolates, 63 (62%) were identified as B. anima/is, 17 (16.8%) as B. longum, 15 (14.8%) as B. breve, 3 (3%) as B. infantis and 3 (3%) as• B. bifidum. Finally, Six (11%) and 49 (89%)

out of 55 isolates

were identified as Enterococcus feacalis and Ent.

feacium, respectively.

When growth performance of the isolated strains was studied, growth rate and doubling time of the selected strains were calculated. According to these parameters, the tested microorganisms could be

classified into two

major groups, i.e. strains with the highest growth

rate ( 0.156 to 0.460 h -J ) and the shmtest doubling time (1.50 to 4.12

h),.and those with the lowest growth rate (0.109 to 0.187 h"1

and the

•longest doubling time( 3.70 to 5.87 h) . The fast growing strains that