[Music] microbial nutrition is the supply of monomers needed for anabolism and growth and some nutrients called macronutrients are required in large amounts for example carbon that's required for for example amino acids and sugars the next most abundant element in the cell is nitrogen remember carbon and nitrogen send the depletion of those send a cell if it's capable into sporulation to make an endospore nitrogen is important in proteins nucleic acids and several other cell constituents nitrogen is available in an inorganic form as we've mentioned previously as ammonia or a nitrite or nitrogen gas which some organisms can use other macron nutrients typically needed in lesser amounts include phosphorus which is required for the syntheses of nucleic acids and phospholipids and sulfur which is required for amino acids also present in several vitamins and in co-enzyme a micronutrients are required as the name implies in small amounts or what we call Trace Amounts and typically these elements are called called Trace elements a great example is iron that we see here iron if you remember played a significant role in cellular respiration growth of most microorganisms occurs by the process of binary fision in this process cells first begin by duplicating their DNA so DNA replication which we'll talk about in an upcoming chapter the DNA as it replicates remains attached to the cytoplasmic membrane during that process and we'll show you how that occurs I'll go through that in an upcoming chapter the cells then elongate to approximately twice their original size and form a partition called the septum that we also came across during spalation process and this is a result of the inward growth of the cytoplasmic membrane and the cell wall and another cell envelope structures from opposing Direction so we've got growth happening here and growth happening here until these two remaining cells hinge off and the septum formation will also separate the DNA molecules so we'll have a DNA molecule in either cell as this process concludes now the interval for the formation of two cells from one is called a generation you'll also see it referred to as doubling time so doubling time is another phrase that you might come across and that doubling time or generation time differs depending on access to certain types of nutritional factors and genetic factors Etc eoli which we've come across quite frequently ecoli will replicate in about 20 minutes other bacteria will take much longer and a few will complete their replication rounds in a shorter amount of time