Abstract:
There is still unexplored reservoir of microorganisms from sediments and water within Lakes Olbolosat
and Oloiden using culture dependent technique. The current study compares bacterial diversity within
Lake Olbolosat a freshwater lake and Lake Oloiden a saline alkaline lake. Out of 60 isolates obtained
from sediments and water samples, 35 were from Lake Olbolosat and 25 from Lake Oloiden. Microbial
count ranged between 0-1.75× 10
5
cfu/ml from both lakes. There was a significant difference between
bacterial density and sampling points (p<0.001, F=6.667), 58 were Gram-positive and 2 Gram-negative.
Fifty-five isolates that were rod-shaped, 3 were cocci and 2 filamentous. There was excellent growth of
isolates at an optimum growth pH range of 6-10, a temperature range of 25-30°C and a salinity range of
0-5%. There was significant difference at p<0.001 for bacterial growth within physiological parameters.
The isolates utilized skimmed milk, starch, olive oil, cellulose powder and xylan, hence the production
of extracellular enzymes. There was antimicrobial activity against Pseudomonas aeruginosa, Bacillus
subtilis, Escherichia coli, Staphylococcus aureus and Candida albicans by bacterial isolates. BLAST
analysis of partial sequences showed there were 4 different phyla. Firmicutes scored 77% closely
affiliated with 20 strains, Actinobacteria scored 15% closely affiliated with 4 strains, Proteobacteria and
Bacteroidetes scored 4% affiliated with 1 strain each. Novel bacteria from this study could provide
insights into their diversity and biotechnological applications.
