Chapter 27 Applied and Industrial Microbiology Copyright The
Chapter 27 Applied and Industrial Microbiology Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display.
Applied Microbiology and Biotechnology • Applied microbiology – microbes are used to treat wastewater and bioremediate damaged environments • Industrial microbiology – use of microbes in making food, medical, manufacturing, and agricultural products • Biotechnology – uses microbes for practical applications • Fermentation – controlled culture of microbes to produce desired organic compounds 2
Water and Wastewater Treatment Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Water purification • In most cities, water is treated in a stepwise process before it is supplied to consumers • Impoundment in large, protected reservoir – storage and sedimentation; treated to prevent overgrowth of cyanobacteria • Pumped to holding tanks for further settling, aeration, and filtration; chemical treatment with a chlorine, ozone, or peroxide disinfectant Catch basin of water Aeration, settling Filtration Pumped to holding tank Sand Charcoal Chlorination Storage Tank of treated water Toconsumerthrough To domestic water pipes 3
Sewage Treatment • Sewage – used wastewater containing chemicals, debris, and microorganisms • Typically requires 3 phases: Primary Stage Secondary Stage Tertiary Stage – Primary phase – removes floating, bulky physical Supernatant Sludge Raw HO sewage digester objects Solids – Secondary phase – Liquid Filtered Mixed Aerated residue removes the organic matter by biodegradation, natural Filtered bioremediation in a large Skimming, Chlorination Settled solids digester forming sludge settling Solid wastes which is aerated by injection Treated sewage released into and stirred Disposal Disposed or reclaimed body of water for anaerobic digester – Tertiary phase – filtration, disinfection, and removal of 4 chemical pollutants Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. 2
Sewage Treatment • Anaerobic digesters: turn sludge into a secondary source of energy • After completing the sewage treatment process, the water is gradually released Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. (a) © Sanitation Districts of Los Angeles County 5 (b) © Sanitation Districts of Los Angeles County
Microorganisms and Food • Microbes and humans compete for nutrients in food • The effects of microorganisms on food can be – Beneficial – Detrimental – Neutral 6
Microbial Fermentations in Food Products Microbes, through fermentation, can impart desirable aroma, flavor, or texture to foods (starter cultures) • Bread – yeast leaven dough by giving off CO 2 Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Carole Ritchie @ USDA-NRCS PLANTS Database • • • Beer – fermentation of wort Wine – fermentation of fruit juices Vegetable products – sauerkraut, pickles Vinegar – fermentation of plant juices Milk and dairy products – cheeses, yogurt 7
Wine Making © Kevin Schafer/Peter Arnold (a) (b) 8
Microbes in Milk Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. © Kathy Park Talaro/Visuals Unlimited (a) (b) 9
Cheese Making 10
Microorganisms as Food • Mass-produced yeasts, molds, algae, and bacteria • Single-celled protein and filamentous mycoprotein added to animal feeds 11
Concept Check: Which of the following is not a stage in purification of drinking water? A. Filtration B. Chlorination C. Activated Sludge D. Sedimentation
Microbial Involvement in Food. Borne Diseases Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. • Food poisoning – diseases caused by ingesting food • 2 types: – Food intoxication – results from ingesting exotoxins secreted from bacterial cells growing in food – Food infection – ingestion of whole microbes that target the intestine – salmonellosis, shigellosis Food Intoxication Food Infection Cell Toxin Cells Ingestion Improper cooking technique Bacteria multiply in food Ingestion Target organs Intestinal infection (a) (b) 13
Bacterial Food Poisoning Agents 14
Prevention Measures for Food Poisoning and Spoilage • Prevent incorporation of microbes into food – Aseptic technique – Handwashing and proper hygiene • Prevent survival or multiplication of microbes in food – – – Heat – autoclaving, pasteurization, cooking Cold – refrigeration, freezing Radiation – UV, ionizing Chemical preservatives – Na. Cl, organic acids Dessication Spraying of bacteriophages 15
Prevention Measures for Food Poisoning and Spoilage Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Care in Harvesting, r Preparation o. C Destruction of Microbes Heat Canning Pasteurization 100 o Cooking o. F 212 o Boiling point Bacterial destruction occurs if high temperatures are maintained long enough Body temperature Radiation Filtration Prevention of Growth Maintenance temperature 62. 8 o 145 o 40 o 104 o 37. 7 o 100 o 37 o 36. 1 o 97 o 15 o 59 o 7. 2 o 45 o 0 o Hot Cold freezing 98. 6 o 32 o Freezing point *Bacteria multiply rapidly Bacteria multiply at a reduced rate Bacterial growth inhibited 0 o Preservative additives Nitrogen salts *Under ideal conditions, bacteria can divide every 20 minutes. At this rate, bacterial numbers could increase from 1 to 2, 097, 152 within 7 hours. 16
General Concepts in Industrial Microbiology • Bulk production of organic compounds such as antibiotics, hormones, vitamins, acids, solvents, and enzymes • Many processes involving fermentation 17
Industrial Enzymes 18
The Industrial Process • Mutant strains of bacteria and fungi that synthesize large amounts of metabolic intermediates (metabolites) – Primary metabolites & Secondary metabolites – Substrate Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Synthesis of only primary metabolites (Production of essential biochemicals) Synthesis of primary and secondary metabolites (Synthesis of byproducts nonessential to growth) Log Number of Viable Cells Stationary phase Death phase Exponential phase Lag phase 19 Time
The Industrial Process • Primary metabolites – produced during major metabolic pathways and are essential to microbe’s function (amino acids, organic acids synthesized during logarithmic growth) • Secondary metabolites – by-products of metabolism that may not be critical to microbe’s function (vitamins, antibiotics, and steroids synthesized during stationary phase) Substrate Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Synthesis of only primary metabolites (Production of essential biochemicals) Synthesis of primary and secondary metabolites (Synthesis of byproducts nonessential to growth) Log Number of Viable Cells Stationary phase Death phase Exponential phase Lag phase 20 Time
Tricks to Increase the Amount of Chosen End Product 1. Manipulate growth environment to increase synthesis of metabolite 2. Select strains that genetically lack a feedback system 3. Many syntheses occur in sequential fashion involving more than one organism – Biotransformation – waste product of one organism becomes the building block of the next 21
Biotransformation Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. C CH 3 Colletotrichum antirrhini CH 3 O C d Rhizopus nigricans CH 3 C O CH 3 OH CH 3 O Progesterone O a Δ 4 -pregnene-3, 20 -dione b Curvularia lunata H 2 COH CH 3 C O 15α-hydroxyprogesterone As oc per hr gil ac lu eu s Da CH 3 s c de ty nd liu ro m C O ide CH 3 s c HO O CH 3 Side reaction HO CH 3 c O 11α-hydroxyprogesterone Corticosterone O CH 3 Δ 4 -pregnene-11β, 21 -diol-3, 20 -dione CH 3 C C O OH O O CH 3 O 17β-hydroxy-11 -dehydrocorticosterone (cortisone) Cortisone H 2 COH CH 3 Fusarium solani C O O CH 3 b O OH O CH 3 H 2 COH b H 2 COH 11 -dehydrocortisone 22
From Microbial Factories to Industrial Factories • Produce appropriate levels of growth and fermentation in a carefully controlled environment Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Motor Addition of nutrient and microbes Cooling water out Sample line Valve • Commercial fermentation carried out in fermentors – a device in which mass cultures are grown, reactions take place, and product develops Impellers Temperature sensor and control unit Cooling jacket Cooling water in Valve Sparger Air in Valve Harvest line Downstream processing Air filter 23
Substance Production 2. 3. 4. • Introduction of microbes and sterile media into reaction chamber Fermentation Downstream processing (recovery, purification, packaging) Removal of waste Carried out aseptically and monitored for rate of flow and quality of product Introduction of Reactants 1. Raw materials Pretreatment with enzymes Growth of stock culture for inoculum Nutrients added Medium sterilized Fermentor chamber Fermentation Steps in mass production: p. H buffer O 2 Medium collected Downstream Processing and Waste Removal • Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Recovery of raw product Microbes recovered Filtration, extraction Purification, drying Packaging Solids collector 24
Substance Production • Batch fermentations – substrate added to system all at once and taken through a limited run until product is harvested • Continuous feed systems – nutrients are continuously fed into the reactor and product is siphoned off throughout run 25
Examples of Industrial Products • Pharmaceutical products – – Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Antibiotics Hormones Vitamins Vaccines • Miscellaneous products – – – Biopesticides Enzymes Amino acids Organic acids Solvents Natural flavor compounds 26
Industrial Products 27
Concept Check: The large tanks used in industrial production of antibiotics are termed A. Digesters B. Fermentors C. Spargers D. Biotransformers
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