Explanation

Log/exponential phase. In the exponential phase of growth (S-shaped), there is a rapid increase in size, cell number and mass of an organism, due to the rapid consumption of nutrients. Due to rapid consumption of nutrient, the growth rate is highest at this phase. Exponential or log phase can not sustain for long period because the nutrients and space are limited and there is competition as well. Microorganism, when nutrients get exhausted, secrete toxic chemicals which inhibit the growth of other organisms