Alcoholic and lactic acid fermentation_lesson 2.pptx

lactic acid and alcoholic fermentation

1. Alcoholic and lactic acid fermentation Zahra Rafi Lecturer Microbiology, UCP

2. Glycolysis Glycolysis produces 2 ATP and 2 NADH when glucose is split into 2 pyruvate (pyruvic acid) Fermentation will break down pyruvic acid further without oxygen, producing a small amount of ATP.

3.  Fermentation consists of glycolysis plus reactions that regenerate NAD+ , which can be reused by glycolysis Two common types are alcohol fermentation and lactic acid fermentation Alcohol is produced by plant cells and Lactic acid is produced by animal cells

4. Fermentation in animal cells produces lactic acid Without O2 present in animal cells, pyruvate will be broken down to form lactate (lactic acid). This is the substance that makes muscles burn during intense exercise. Humans can break down the lactic acid further to produce a little more ATP when O2 is scarce.

5. Lactic acid fermentation in some yeast and bacteria some yeasts and bacteria also produce lactic acid from fermentation. Lactic acid from these sources produces yogurt and cheese.

6. Comparing fermentation and aerobic cellular respiration Both processes break down glucose to release energy. Fermentation produces 2 ATP per glucose, Aerobic Cellular Respiration produces 38 ATP Electrons from glucose go to either lactic acid or alcohol in fermentation Electrons from glucose go to Oxygen in Cellular Respiration.

7. Obligate anaerobes Vs. facultative anaerobes Obligate anaerobes carry out fermentation or anaerobic respiration and cannot survive in the presence of O2 Yeast and many bacteria are facultative anaerobes, meaning that they can survive using either fermentation or cellular respiration In a facultative anaerobe, pyruvate is a fork in the metabolic road that leads to two alternative catabolic routes, Obligate Anaerobes Vs. Facultative Anaerobes:

8. Alcoholic fermentation  Alcohol fermentation is done by yeast and some kinds of bacteria. These microorganisms convert sugars in ethyl alcohol and carbon dioxide. Alcoholic fermentation begins after glucose enters the cell. The glucose is broken down into pyruvic acid. This pyruvic acid is then converted to CO2, ethanol, and energy for the cell. Humans have long taken advantage of this process in making bread, beer, and wine. In these three products the same microorganism is used: the common yeast or Saccharomyces Cerevisae . Hence we used different classification of sugars in this experiment to verify its feasibility and distinction in their reaction. Moreover as this experiment aimed to degrade sugars into its glucose units, the resultant precipitate will be forming rapidly when we used the glucose as sugar. The rate of production in getting more Ba (Co3)2 will depend on the sugar component of the sample used, as long as it can be degraded into glucose the more the reaction will be possibly occur.

9. Introduction ALCOHOL FERMENTATION- is done by yeast (Saccharomyces Cerevisae ) and some kinds of bacteria. Baker’s yeast- commonly used as a leavening in baking bread and bakery products. -a single-celled microorganism found on and around the human body. In the process, these microorganisms convert sugars in ethyl alcohol and carbon dioxide. Alcoholic fermentation begins after glucose enters the cell. The glucose is broken down into pyruvic acid. This pyruvic acid is then converted to CO2, ethanol, and energy for the cell.

10. Conversion reaction

11. Species used Bacteria: Zymomonas mobilis Clostridium acetobutylicum Klebsiella pneumoniae Yeast Saccharomyces cerevisiae Saccharomyces carlsbergenesiae Saccharomyces saki Saccharomyces oviformis Candida utilis Mucur sp.

12. Zymomonas Saccharomyces carlsbergenesiae

13. Fermentation substrates SUGARY MATERIALS: Molasses Suger cane Sugar beet Sweet potato Sulfide waste Weet sorgum Whey glucose , Succrose , Lactose

14. STARCHY MATERIALS cereals: wheat, maize, barley, sorgum , corn, rice Roots: potato, tropica Mild products: wheat flour, corn feed CELLULOSIC MAT ERIALS: Wood ,Paper waste, Agricultural waste

15. Conditions for fermentation Carbon sources: pure sugar or crude sugars/molasses (10-18%). Nitrogen sources: Mostly available in the form of ammonium sulphate. Growth factors: can be provided in the form of molasses. pH: 4.8-5.0. Temperature: 70-80°F. Temp. can be controlled by cooling jacket. Time : Depends on yeast strain. Usual time is between 30 to 72hrs. Yield: 0.4 gallon of ethyl alcohol per one gallon of molasses. 90% carbohydrates can be converted in to alcohol.

16. Inoculum size  In range of 3% to 10% with an average about 4% Media: 10 -18%. Concentrations greater than 20% are not employed as they cold be detrimental to yeast.

17. Product recovery Distillation is a separation process for a mixture of liquids or oils. It relies on differences in the boiling points of the component liquids to be separated. Alcohol can be obtained by distillation and column is known as rectified column. Can also be recovered by fractional distillation. Distillate contains 95.6% ethyl alcohol and 4.4% water.

18. By-products Three byproducts generated 1.Carbon dioxide- used for production of dry ice and pure form used for preparation of soft drinks. 2.Yeast biomass- used for animal fodder because it contains high protein, vitamins etc. 3.Distillery effluents- used as a fertilizer and animal feed.

19. Uses Fuels ; Some alcohols, mainly ethanol and methanol can be used as an alcohol fuel Preservative Solvents Alcohols have applications in industry and science as reagents or solvents ethanol can be used as a solvent in medical drugs, perfumes and vegetable essences such as vanilla  Alcoholic beverages Antifreeze Antiseptics Ethanol can be used as an antiseptic to disinfect the skin.