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Nutrition & Cultivation of Prokaryotes. Hugh B. Fackrell Filename: nutrient.ppt. Presentation Outline. Essential Minerals Essential Nutritional Elements Energy Sources phototrophs vs chemotrophs Carbon Sources autotrophs vs heterotrophs Vitamins Culture Media. Essential Metal Ions.
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Nutrition & Cultivation of Prokaryotes Hugh B. Fackrell Filename: nutrient.ppt
Presentation Outline • Essential Minerals • Essential Nutritional Elements • Energy Sources • phototrophs vs chemotrophs • Carbon Sources • autotrophs vs heterotrophs • Vitamins • Culture Media
Essential Metal Ions ++ • Mg • Fe • K • Mn • Zn • Cu • Co • Ca ++ + ++ ++ ++ ++ ++
Functions of Metal Ions • Chlorophyll: magnesium • Cytochromes: iron • electron transport systems • Enzyme activators • many different metals
Nutritionally Essential Elements • C carbon • H hydrogen • O oxygen • N nitrogen • P phosphorus • PO of HPO • S sulfur _ _ _ 3 4
Nutrients • Used to produce new energy • Used as building blocks for cellular material
Carbon Sources • Autotroph • also called lithotroph • use inorganic carbon • carbon dioxide, bicarbonate, carbonate • Heterotroph • also called organotrophs • use organic carbon • carbohydrates, amino acids, orgainc acids etc
Energy Sources • Phototroph • energy from light • Chemotroph • energy from chemical oxidation Oxidation release of electrons which are “captured” and used for energy
Energy + Carbon Source • Photo Auto troph • photolithotroph • Photo Hetero troph • photoorganotroph • Chemo Auto troph • chemolithotroph • Chemo Hetero troph • Chemoorganotroph
Oxidation • Inorganic • Hydrogen sulfide >>> sulfate • (H S >>> SO ) • Organic • Glucose >>> CO + H 0 • Acetic acid >>> _ _ 2 4 2 2
Electron Transport Systems • Proteins found in the membrane • “Capture” the electrons in electron acceptors + - 2H + 2 e + 1/2 0 = H O 2 2
Food Sources for Essential Elements • Hydrogen • water, hydrogen gas • Oxygen • inorganic salts or organic molecules • Nitrogen • N , NO , NO , NH , NH • Sulfur • SO , HSO , S , SH (in organic compounds) 2 2 3 3 4 _ _ _ 3 4
Protein digests contain polypeptides and amino acids Digests excellent natural sources of CHONPS
Vitamins • Essential organic growth factors which microbe CANNOT synthesize • e.g. Water soluble B vitamins • Thiamine, B1 • Riboflavin, B2 • Niacin (nicotinic acid) • Pyridoxine, B6 • Cyanocobolamine, B12 • Pantothenic acid, biotin, folic acid
Many microbes synthesize their own vitamins Therefore many do not require vitamin supplements
Function of Vitamins • Co enzymes • co factors for enzymes • Prosthetic groups
Saprophytes • free living, simple nutritional needs • ammonia, phosphate, sulphate, metals • Autotrophs, carbon dioxide • Heterotrophs :glucose
Commensals/ Parasites/Predators • Complex nutritional needs • Glucose • Amino acids • Sulfate or SH • phosphate, • trace metals • B vitamins • Special nutrients Blood serum live bacteria alga • Biopolymers
Common Organic Nutrients • Amino Acids • Carbohydrates • Monosaccharides • Disaccharides • Lipids • Fatty acids + glycerol • Nucleotides • Pentose sugar + phosphate
Common Organic Polymers • Proteins (MW 10,000-1,000,000] • polymers of amino acids • enzymes, structural components • Nucleic acids • polymers of nucleotides • information storage & retrieval • Polysaccharides( 10,000- 1,000,000,000,000] • polymers of monosaccharides • structural, energy reserves
Compound Macromolecules • Glycoproteins • Lipoproteins • Lipopolysaccharides • Nucleoproteins • aggregates • chromatin DNA + proteins • Glucoslyated nucleic acids
Types of Culture Media • Undefined • Chemically defined • Complex • Anaerobic growth • Special purpose • selective (enrichment) • differential
Undefined Medium • General purpose • Nutrient Broth • protein digest • e.g. tryrpticase soy =>trypsin digested soybean proteins • amino acids, peptides ammonium sulfate, salt, phosphate buffer pH 7.4 • Nutrient Agar • 0.5-1.5% agar (seaweed polysaccharide] • melting point
Chemically Defined Medium • Known pure reagents • organic or inorganic • Exact duplication of experiments • biochemistry • enzymes • toxins • some vaccines
“Complex” Medium • Broth or agar • Undefined + supplements • Nutrient + blood • Loeffler’s • Chocolate agar
Anaerobic Growth Medium • Undefined media + “Reducing compounds” • Oxygen removed from the media • Thioglycolic acid • Cooked meat - SH groups
Selective or Enrichment Media • Contains substances that inhibit many microbes and allow a limited number of species to grow • Easier to isolate microbes that may be few in number eg Salmonella & Shigella • Phenethyl alcohol agar inhibits growth of Gram negative • Desoxycholate Agar inhibits Gram positive • Lactose fermentors turn indicator red
Differential Media • Supports growth of wide range of microbes • Emphasizes variable characteristics • Blood agar> hemolysis • “Sugars” • Carbohydrate + nutrient + pH indicator • Acid > base Purple> yellow = fermentation • DNAse agar