VMC 211: General Veterinary Microbiology (1+1)

NUTRIENTS REQUIRED

• Nitrogen is required by all organisms. Bacteria are versatile in this respect. Some bacteria can use atmospheric nitrogen. Others use inorganic nitrogen compounds such as nitrates, nitrites and ammonium salts. Some can use nitrogen from organic compounds like amino acids.
• Water is required by all organisms. All nutrients must be in aqueous solution before they can enter the cells. Water is a highly polar compound and efficient in dissolving and dispersing cellur components and to provide suitable conditions for metabolic reactions. High specific heat of water provides resistance to sudden transient temperature changes in the environment. It is also required for many hydrolytic reactions in the cell.

• Oxygen can be obtained from  water, atoms in various nutrients or molecular oxygen.
• Sulphur is needed for synthesis of amino acids cysteine,cystine and methionine. Some bacteria require organic sulfur compounds. Some can use inorganic sulfur compounds. Some can even use elemental sulfur.
• Phosphorus is a component of nucleotides, nucleic acids, phospholipids, teichoic acids and other compounds. It is usually supplied as phosphate.
• All organisms require metal ions like potassium, calcium, magnesium and iron. Zinc, copper, manganese, nickel and cobalt are needed at very low concentrations. They are often called as trace elements. Iron, magnesium, zinc, manganese and cobalt are cofactors for different enzyme systems.
• Vitamins and vitamin like compounds function as coenzymes or as building blocks for coenzymes. Some bacteria can synthesize vitamins from other compounds in the medium. Others need the vitamins and will not grow without the required vitamins.