Studying some of the optimal conditionals for the best bacterial isolates from soil and its effects on their growth rates

Abstract

The current study aimed to use some bacterial isolates from the local soil of Baghdad city by study the effects of temperature, pH and incubation period on the growth rates of isolated bacteria and choose the optimal conditions for their diversity and for understanding bacterial growth and their requirements for survival and proliferation. This information can be applied to obtain their high growth rate for use in various fields such as agriculture, medicine and environmental sciences in the future. And it used to assess the degree of variation in across bacteria species in pH, temperature and incubation period. A number of local bacterial isolates as Enterobacter cloacae, Aeromonas hydrophila, Pantoea spp., Pseudomonas mendocina and Serratia fonticola identified in this study. The growth rate of the bacterial isolates was tested by growing each bacterial isolate in a different range of pH (4, 7 and 10) and under the influence of several temperatures (52, 35 and 50) and within different incubation periods (24, 48 and 72) hours The optimal conditions were determined by measuring the optical density (absorbance) at a wavelength of 600 nm, which represents bacterial growth. The optimal conditions for E. cloacae were determined to be a pH of 10 and a temperature of 35°C after a 72hour incubation period. Similarly, A. hydrophila exhibited optimal growth at a pH of 7 and a temperature of 35°C after a 72hour incubation period. Pantoea spp. demonstrated optimal growth at a pH of 7 and a temperature of 25°C after a 24hour incubation period. P. mendocina displayed optimal growth at a pH of 7 and a temperature of 25°C after a 72hour incubation period. Lastly, S. fonticola exhibited optimal growth at a pH of 7 and a temperature of 50°C after a 72hour incubation period.