Applied and Industrial Microbiology Chapter 28 Applied and Industrial Microbiology

Q&A To produce ethanol, yeasts require anaerobic conditions. In what widely used industrial product does the growth of Saccharomyces cerevisiae require aerobic conditions?

Food Microbiology 28-1 Describe thermophilic anaerobic spoilage and flat sour spoilage by mesophilic bacteria. 28-2 Compare and contrast food preservation by industrial food canning, aseptic packaging, radiation, and high pressure. 28-3 Name four beneficial activities of microorganisms.

Historically… Drying Osmotic pressure (salt or sugar) Fermentation

Foods and Disease Hazard Analysis and Critical Control Point (HACCP) FDA USDA

Industrial Food Canning Figure 28.1

Commercial Canning Retorts Figure 28.2

Construction of a Metal Can Figure 28.3

Commercial Sterilization Destroys C. botulinum endospores 12D treatment kills 1012 endospores Surviving endospores of thermophilic anaerobic spoilage with gas Or flat sour spoilage

Food Preservation Aseptic packaging: Presterilized materials assembled into packages and aseptically filled Figure 28.4

Ionizing Radiation Figure 28.5, Table 28.2

Food Preservation High-energy electrons High-pressure: 87,000 psi Figure 28.7

Cheese Curd: Solid casein from lactic acid bacteria and rennin Whey: Liquid separated from curd Hard cheeses are produced by lactic acid bacteria Semisoft cheeses are ripened by Penicillium on surface

Making Cheddar Cheese Figure 28.8

Making Red Wine Figure 28.9

Alcoholic Beverages and Vinegar Beer and ale are fermented starch Malting: Germinating barley converts starch to maltose and glucose For sake, rice starch is converted to sugar by Aspergillus Wine is fermented plant sugars Yeast ferment sugars to ethanol + CO2 Grape wine requires bacterial malolactic fermentation Acetobacter and Gluconobacter convert ethanol to acetic acid

Microbial Metabolism Sugar Ethanol + CO2 Malic acid Lactic acid Saccharomyces cerevisiae Malic acid Lactic acid Lactic acid bacteria Ethanol Acetic acid Acetobacter or Gluconobacter

Q&A To produce ethanol, yeasts require anaerobic conditions. In what widely used industrial product does the growth of Saccharomyces cerevisiae require aerobic conditions?

Is botulism a greater danger in spoilage of canned goods under thermophilic or under mesophilic conditions? 28-1 Canned foods are usually in metal cans. What sorts of containers are used for aseptically packaged foods? 28-2 Roquefort and blue cheeses are characterized by blue-green clumps. What are these? 28-3

Industrial Microbiology 28-4 Define industrial fermentation and bioreactor. 28-5 Differentiate primary from secondary metabolites. 28-6 Describe the role of microorganisms in the production of industrial chemicals and pharmaceuticals. 28-7 Define bioconversion, and list its advantages. 28-8 List biofuels that can be made by microorganisms.

Biotechnology Use of microorganisms, cells, or cell components to make a product Classical: Fermentation Recombinant DNA

Fermentation Technology Figure 28.10a

Fermentation Technology Figure 28.10b

Production Curve of a Primary Metabolite Figure 28.11a

Production Curve of Secondary Metabolite Figure 28.11b

Immobilized Cells Figure 28.12

Industrial Products Xanthan Amino acids Citric acid Enzymes Vitamins Antibiotics Steroids Applications, p. 801

Copper Extraction by Leaching Figure 28.14

Alternative Energy Sources Using Microbes Bioconversion Biomass Methane or ethanol Figure 28.15

Biofuels Cellulose digested by cellulase Sugars fermented to ethanol or higher alcohols or hydrogen Algal oils Figure 28.16

Industrial Microbiology and the Future Food processing Pharmaceuticals from rDNA technology Ethanol and hydrogen And more

Are bioreactors designed to operate aerobically or anaerobically? 28-4 Penicillin is produced in its greatest quantities during the trophophase of fermentation. Does that make it a primary or secondary metabolite? 28-5 At one time, citric acid was extracted on an industrial scale from lemons and other citrus fruits. What organism is used to produce it today? 28-6 Landfills are the site of a major form of bioconversion—what is the product? 28-7 How can microbes provide fuels for cars and electricity? 28-8