Nutritional types of bacteria [photo 1 ithotrophic, chemotrophic, phtoorganotrophic, chemoorganotrophic], entry of nuitrients, passive and active transport, bacterial growth, growth curv , factors affecting growth.
All microorganisms requires source of energy to carry out cellular activity, source of electron to carry out various metabolism and source of carbon to synthesize various cellular components. the microorganisms are also furthur classified into various types on the basics of their nutritional type such as; phototrophs, chemotrophs, autotrophs and heterotrophs. These groups of bacteria are also separated into different types of sub-groups.
In higher grade of animals growth means increase in size and volume of body but in case of bacteria growth refers to the increases in number of bacteria. if bacterial population is measured at different interval of time and the log of population is plotted against time in a graph then it gives a growth curve.There are four growth cycles in bacteria they are lag phase, log phase, stationery phase and death phase.
There are various physical factors and biological factors that affect the growth of microorganisms. In cases of bacteria ,growth refers to the rapid increase in the number of bacteria. Some physicals requirements for proper growth of bacteria are temperature, gaseous environment. The chemical factors such as acidity alkalinity of teh culture medium also affects the growth of microorganisms.