Nutrisi pertumbuhan englsh 2 new again.pptx
- 1. Elements of Microbial Nutrition, Ecology and Growth
- 2. 2 Microbial nutrition • Macronutrients – required in large quantities; play principal roles in cell structure & metabolism – proteins, carbohydrates • Micronutrients or trace elements – required in small amounts; involved in enzyme function & maintenance of protein structure – manganese, zinc, nickel
- 3. 3 Nutrients • Inorganic nutrients– atom or molecule that contains a combination of atoms other than carbon and hydrogen – metals and their salts (magnesium sulfate, ferric nitrate, sodium phosphate), gases (oxygen, carbon dioxide) and water • Organic nutrients- contain carbon and hydrogen atoms and are usually the products of living things – methane (CH4), carbohydrates, lipids, proteins, and nucleic acids
- 4. 4 Chemical composition of cytoplasm • 70% water • proteins • 96% of cell is composed of 6 elements – Carbon – Hydrogen – Oxygen – Phosphorous – Sulfur
- 5. 5 Obtaining Carbon • Heterotroph – an organism that must obtain carbon in an organic form made by other living organisms such as proteins, carbohydrates, lipids and nucleic acids • Autotroph - an organism that uses CO2, an inorganic gas as its carbon source – not dependent on other living things
- 6. 6 Nitrogen • Main reservoir is nitrogen gas (N2) • 79% of earth’s atmosphere is N2 • Nitrogen is part of the structure of proteins, DNA, RNA & ATP – these are the primary source of N for heterotrophs • Some bacteria & algae use inorganic N nutrients (NO3 - , NO2 - , or NH3) • Some bacteria can fix N2 • Regardless of how N enters the cell, it must be converted to NH3, the only form that can be combined with carbon to synthesis amino acids, etc.
- 7. 7 Oxygen • major component of carbohydrates, lipids and proteins • plays an important role in structural & enzymatic functions of cell • component of inorganic salts (sulfates, phosphates, nitrates) & water • O2 makes up 20% of atmosphere • essential to metabolism of many organisms
- 8. 8 Hydrogen • major element in all organic compounds & several inorganic ones (water, salts & gases) • gases are produced & used by microbes • roles of hydrogen – maintaining pH – forming H bonds between molecules – serving as the source of free energy in oxidation- reduction reactions of respiration
- 9. 9 Phosphorous • main inorganic source is phosphate (PO4 -3 ) derived from phosphoric acid (H3PO4) found in rocks & oceanic mineral deposits • key component of nucleic acids, essential to genetics • serves in energy transfers (ATP)
- 10. 10 Sulfur • widely distributed in environment, rocks, sediments contain sulfate, sulfides, hydrogen sulfide gas and sulfur • essential component of some vitamins and the amino acids: methionine & cysteine • contributes to stability of proteins by forming disulfide bonds
- 11. 11 Important mineral ions • Potassium • Sodium • Calcium • Magnesium • Iron
- 12. 12 Growth factors • organic compounds that cannot be synthesized by an organism & must be provided as a nutrient – essential amino acids, vitamins
- 13. 13 Carbon source Energy source photoautotrophs CO2 sunlight chemoautotrophs CO2 Simple inorganic chemicals photoheterotrophs organic sunlight chemoheterotrophs organic Metabolizing organic cpds
- 14. 14 • Saprobes – decompose dead organisms, recycle elements, release enzymes to digest materials • Parasites – utilize tissues and fluids of a living host and cause harm
- 15. 15 saprobes
- 16. 16 Transport mechanisms • Passive transport –do not require energy, substances exist in a gradient and move from areas of higher concentration towards areas of lower concentration – Diffusion – Osmosis - water – Facilitated diffusion – requires a carrier • Active transport – require energy and carrier proteins, gradient independent – Carrier-mediated active transport – Group translocation – transported molecule chemically altered – Bulk transport – endocytosis, exocytosis, pinocytosis
- 17. 17 diffusion
- 18. 18 osmosis
- 19. 19
- 23. 23 Environmental influences on microbial growth • temperature • oxygen requirements • pH • electromagnetic radiation • barometric pressure
- 24. 24 3 cardinal temperatures • Minimum temperature – lowest temperature that permits a microbe’s growth and metabolism • Maximum temperature – highest temperature that permits a microbe’s growth and metabolism • Optimum temperature – promotes the fastest rate of growth and metabolism
- 25. 25 3 temperature adaptation groups 1. Psychrophiles – optimum temperature below 15o C, capable of growth at 0o C 2. Mesophiles – optimum temperature 20o - 40o C, most human pathogens 3. Thermophiles – optimum temperature greater than 45o C
- 26. 26 3 temperature adaptation groups
- 28. 28
- 29. 29 Microbial associations • Symbiotic – organisms live in close nutritional relationships; required by one or both members – Mutualism – obligatory, dependent; both members benefit – Commensalism – commensal member benefits, other member not harmed – Parasitism – parasite is dependent and benefits; host is harmed
- 30. 30 Microbial associations • Non-symbiotic – organisms are free-living; relationships not required for survival – Synergism – members cooperate and share nutrients – Antagonism – some member are inhibited or destroyed by others
- 33. 33 Growth curve
- 34. 34 Growth curve 1. Lag phase – “flat” period of adjustment, enlargement; little growth 2. Exponential growth phase – a period of maximum growth will continue as long as cells have adequate nutrients & a favorable environment 3. Stationary phase – rate of cell growth equals rate of cell death cause by depleted nutrients & O2, excretion of organic acids & pollutants 4. Death phase – as limiting factors intensify, cells die exponentially in their own wastes
- 35. 35 Turbidity