Bacterial culture is a perfect way to study the growth rate. This method is not specified for a matter, it is a necessary part of microbiological studies. The growth of bacterial cells is affected by different factors such as temperature, waste, pH and nutrients resources. Since the study is related to numbers and amount of substances, mathematical methods are needed to know the quantity of bacteria in the experiment hence, exponential. In addition, growth rate is proportional to the number of cells. As the nutrients supplies increase the amount of bacteria increase. However, when the nutrients are less than the normal state, the cell division will decrease hence, the bacterial cell might be negligible, as the rate of the death will exceed the rate of growth cells. According to Henrici, the size of the cells is different in the growth phases that bacteria goes throw it, log phase, lag phase, stationary and death. Also Monod has study about growth rate that depend on nutrients.

INTRODUCTION:
In 1674 there was a scientist who is called Anton Van Leeuwnhoek, he was the first human who discovered microscopic living organisms called bacteria. This is the beginning of bacteria culture in which experiments are done on it. There are some factors effects on bacteria growing like temperature, PH, wastes, nutrients resources. In this report we will study the dependence of growth rates on nutrients. Bacteria growth is finite and it is known as the increment of size and cell mass. A