| dc.description.abstract | The escalating concern over antibiotic resistance and its profound impact on public health have
underscored the urgent need to explore alternative reservoirs of antimicrobial agents. In this regard,
Actinomycetes have emerged as a compelling area of investigation due to their remarkable capacity
to produce bioactive compounds. Therefore, this study sought to investigate the influence of pH and
various carbon and nitrogen sources on the antibacterial activity of Actinomycetes isolates collected
from Lake Elementaita and River Tana. By examining the effects of these factors, we aimed to gain
insights into the optimization of growth conditions and nutrient availability to enhance the production
of bioactive compounds with potent antibacterial properties. The Actinomycetes isolates used in this study were from Lake Elementaita and River Tana, known for their diverse ecological characteristics
and potential as sources of bioactive compounds. The isolates were subjected to morphological,
biochemical, and molecular techniques to ensure accurate identification. To assess the antibacterial
activity of the Actinomycetes isolates, they were tested against E. coli using the agar well diffusion
method. The independent variables examined in this study were pH levels (4, 7, and 9) as well as
different carbon sources (fructose and sucrose) and nitrogen sources (urea and sodium nitrate). The
diameter of the inhibition zones served as the dependent variable. The data collected on the effects
of pH and nutrients on the inhibition zones of Actinomycetes isolates were subjected to statistical
analysis. One-way ANOVA was performed to assess significant differences in antibacterial activity
among the isolates under different carbon and nitrogen preference. Mean values were compared
using the LSD test at a significance level (α) of 0.05. Furthermore, the Kruskal-Wallis test was
utilized to analyze the pH preferences of the Actinomycetes isolates at a significance level (α) of
0.05. The results showed that pH significantly influenced the bioactivity of the Actinomycetes
isolates, with pH 7 exhibiting the highest inhibition zones against E. coli. The isolates displayed
varied antibacterial activities depending on the carbon and nitrogen sources provided. Sucrose was
the most preferred carbon source, followed by fructose, while urea was the preferred nitrogen
source, followed by sodium nitrate. The study concluded that pH and nutrient availability play crucial
roles in determining the antibacterial activity of Actinomycetes isolates. Other than contributing to
our in-depth understanding of the factors influencing the antimicrobial potential of Actinomycetes,
the results of this study highlight the importance of optimizing growth conditions and nutrient
availability to enhance the production of bioactive compounds with potent antibacterial
properties. Further investigations and exploration of Actinomycetes from diverse
environments are recommended to discover new bioactive molecules for combating antibiotic
resistance. | en_US |
