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Applied and Industrial MicrobiologyPresented in Partial Fulfilment of the course: BIOL360: General MicrobiologyGroup 8 Winston Swaby 24100029 Karene Benjamin 18101051 Applied MicrobiologyUse of microbes in their natural environment to perform processes useful to humankind such as in food processing.Food Microbiology

There is an increase in the likelihood that foods might be a source of widespread disease outbreak as a consequence of the centralized processing and production of foods that are widely distributed. Local agencies whose role is to inspect dairies and restaurants have been established.The FDA and USDA in USA also maintain a system of inspectors at ports and central processing locationFoods and Diseases Heat must be adequate to kill spoilage organisms and pathogens without degrading the appearance and palatability of food. Industrially canned goods undergo commercial sterilization. This is done by steam under pressure in a large retort. Much like autoclavingIndustrial Food CanningCommercial Canning Retorts

The Commercial Sterilization Process in Industrial Canning

The aim of commercial sterilization is to kill Clostridium botulinum which causes botulism. Thermophillic microbes survive commercial sterilization.These microbes do not grow at temperatures below 45oC; so, they usually do not cause spoilage at normal temperatures.

The Construction of a Metal Can

Under circumstances where the canned foods are incubated at high temperatures thermophilic microbes can grow and cause spoilage.Mesophiles can cause spoilage in canned foods if it is under-processed or if the can leaks.

Canned Food SpoilageThermophilic Anaerobic Spoilage Swollen can, lowered pH and sour odour. Usually caused by Thermoanaerobacterium thermosaccharolyticum.Flat Sour Spoilage No swelling, lowered pH, sour and turns cloudy. Usually caused by Geobacillus stearothermophilus.Putrefactive anaerobic Swollen can, putrid odour, may be partially digested and pH slightly above normal. Types of Spoilage in Canned FoodsUsed on materials that cannot tolerate heat such as plastics or laminated paper. Sterilized using hot hydrogen peroxide solution sometimes in association with UV light. High energy electron beams can also used be used.Aseptic Packaging Inhibits DNA synthesis and prevents microbes, insects, and plants from reproducing.X rays or the gamma rays produced by radioactive cobalt-60 are most used. Up to certain energy levels, high energy electrons produced by electron accelerators are also used.Result is inactivation of the target organisms without inducing radioactivity in the food or packaging material.Radiation Use in PreservationA Gamma Ray Irradiation Facility

International Radura Symbol

Electron Beam Accelerator

More accurately known as High Pressure Food Preservation.Pre-wrapped foods such as fruits, deli meats, and precooked chicken strips are submerged into tanks of pressurized water.Pressure as high as 87,000psi is reached. Kills bacteria such as Salmonella, Listeria and pathogenic strains of Escherichia coli by disrupting cellular functions. PascalationIt also kills non-pathogenic microorganisms that tend to shorten the shelf life of the foods preserved by it. Since the process does not require additives it does not need regulatory approvals. It has the advantage of preserving colors and tastes of foods better than many other methods and does not provoke the concerns of irradiation.Role of Microbes in Food Production

CheeseButterButter MilkYogurtKefir KumisSauerkraut

PicklesOlivesCocoa BeerVinegar Sake Wine

Foods that Use Microbes in their Production and ProcessingDairy ProductsThe curd used in cheese production is formed from the action of the enzyme rennin. The acidic conditions needed by the enzyme for it to work is provided by lactic acid forming bacteria.These bacteria also give the characteristic flavours and aromas of fermented dairy products during the ripening process.CheeseThe holes in Swiss cheese is as a result of the carbon dioxide produced by a Propionibacterium species.Semisoft cheeses, such as Limburger, are ripened by bacteria and other contaminating organisms growing on the surface.

Blue and Roquefort cheeses are ripened by Penicillium molds inoculated into the cheese.

Butter is made by churning cream until the fatty globules of butter separate from the liquid.The liquid is called buttermilk.The classic flavor and aroma of these foods are from diacetyls, a combination of two acetic acid molecules.It is a metabolic end-product of fermentation by some lactic acid bacteria.Butter and Butter MilkThe milk from which commercial yogurt is made one-fourth less water and thus it is thickened. The resulting thickened milk is inoculated with a mixed culture of Streptococcus thermophilus, chiefly for acid production, and Lactobacillus delbrueckii bulgaricus, for flavor and aroma. Striking a balance between these two bacteria will determine how the yogurt taste. YogurtNon-Dairy ProductsThe sugars in bread dough are fermented by yeasts. The species of yeast used in baking is Saccharomyces cerevisiae.The tart flavour of breads such as rye or sourdough is as a result of lactic acid bacteria growing in the dough. BreadMicrobes take part in the production and processing of almost all alcoholic beverages. Beer and ale are products of grain starches fermented by yeast.The yeast in beer fermentation remains on the bottom (bottom yeasts) and the fermentation process is slow.On the other hand ale is fermented relatively rapidly, at a higher temperature, with yeast strains that usually form clumps that are buoyed to the top by CO2 (top yeasts).Alcoholic BeveragesDuring malting grains containing starch are allowed to sprout then dried and ground. The resulting product which is called malt contains amylases that convert cereal starches into carbohydrates that can be fermented by yeasts.In light beer production either amylases or selected strains of yeasts are used to convert more of the starch to glucose and maltose. The result is less carbohydrates and more alcohol

Yeast cannot directly use starch for fermentation.However, in wine production fruits such as grapes that have sugars that can be directly fermented are used. Therefore, malting is unnecessary.When grapes have high concentrations of malic acid lactic acid bacteria are used to convert it to lactic acid. The process is called Malolactic FermentationWine MakingWine Production Process

Carbohydrates are first anaerobically fermented by yeasts to produce ethanol.The ethanol is the aerobically oxidized by acetic acidproducing bacteria of the genera Acetobacter and Gluconobacter to acetic acid.Vinegar ProductionIndustrial MicrobiologyThis also involves the use of microorganisms to achieve specific goals. However, it generally focuses on products such as pharmaceutical, medical compounds and biofuels that have economic value.Fermentation Technology

This is the large scale cultivation of microbes or other single cells to produce a commercially valuable substance.Vessels used are called bioreactors.Aeration, pH control, and temperature control are vital components of their design.The process is used in biotechnology to obtain useful products from genetically modified plant and animal cells. Industrial Fermentation

Microbes in industrial fermentation either produces primary metabolites or secondary metabolites.Primary metabolites are formed at the same time as the new cells. For example, ethanol. Secondary metabolites are not produced until the cell has essentially completed its logarithmic growth phase and enters the death phase of the cycle. For example, penicillin. The end of the logarithmic growth phase is called the trophophase.Metabolomics is the use of the chemical fingerprints left by the microbes of their cellular metabolism to study cellular process involving metabolites.Strains development and improvement is an ongoing process. A microbial strain differs physiologically in some significant way.

Industries are increasing their use of free enzymes isolated from microbes to manufacture many products, such as high-fructose syrups, paper, and textiles. The demand for such enzymes is high because they are specific and do not produce costly or toxic waste products.Unlike traditional chemical processes that require heat or acids, enzymes work under moderate conditions and are safe and biodegradable.Immobilized EnzymesIndustrial Products

Amino acids such as lysine and methionine cannot be synthesized by animals and are present only at low levels in the normal diet. Therefore, lysine and some other essential amino acids are commercially prepared and placed in cereals and food supplements. Aspartic acid and phenylalanine are important amino acids used in the sugar free sweetener aspartame. Amino AcidsCitric acid gives tartness and flavor to foods. It is an antioxidant and pH adjuster in many foods, and in dairy products it often serves as an emulsifier.As a result of these important functions Over 1.6 million tons of citric acid are produced every year worldwide. The most being produced by by a mold, Aspergillus niger, with molasses used as a substrate.Citric AcidWidely used in different industries. For example:Amylase used in to break down starch to sugars that yeast can ferment.Glucose isomerase - it converts the glucose that amylases form from starches into fructose, which is used in place of sucrose as a sweetener in many foods.Rennin used to form the curd which is the precursor to cheese.

Enzymes Microbes can provide an inexpensive source of some vitamins. Vitamin B12 is produced by Pseudomonas and Propionibacterium species. Riboflavin (B2 ) is produced by fermentation, mostly by fungi such as Ashbya gossypii.Vitamin C (ascorbic acid) is produced at the rate of 60,000 tons per year by a complicated modification of glucose by Acetobacter species.Vitamins Many antibiotics are produced by microbial fermentations.The production of vaccines against bacterial diseases usually requires the growth of large amounts of the bacteria.Microorganisms can synthesize steroids from sterols or from related, easily obtained compounds.Pharmaceuticals

Thiobacillus ferrooxidans is used in recovering otherwise unprofitable grades of copper ore, which sometimes contain as little as 0.1% copper. At least 25% of the worlds copper is produced this way.This process, although very time consuming, is economical and can recover as much as 70% of the copper in the ore.Copper Extraction by LeachingBiological Leaching of Copper Ores

Alternative Energy Sources

Biomass is the collective organic matter produced by living organisms, including crops, trees, and municipal wastes.Microbes can be employed to convert biomass into alternative energy sources through a process called bioconversion. Bioconversion can also decrease the amount of waste materials requiring disposal.Many communities produce useful amounts of methane from wastes in landfill sites. Methane Production from Solid Waste in Landfill

The answer to the very expensive and sometimes uncertain fossil petroleum-based fuels.E10 Ethanol 10% is where initial interests in biofuels were placed.About a third of Brazils transportation fuel is ethanol. Jamaica also uses E10.In the USA E85 (ethanol 85%) is also used. BiofuelsThe limitations of ethanol which include: Ethanol having 30% less energy than gasoline.Not being able to be transported by conventional pipelines (because it absorbs water so avidly).The pressure it creates on the supply and price of valuable food stuff that is used in its production.Has resulted in increased interest in fuels derive from cellulosic materials , such as cornstalks, wood, and wastepaper, and from exotic nonfood plants such as jatropha, camelina, and miscanthus.

The technology for producing ethanol from cellulose is less well known and more expensive than that from corn or sugarcane.Genes to synthesize the enzymes that can break down cellulosic materials have been genetically introduced into Escherichia coli.Cellulose sources also contain significant amounts of a similar component, hemicellulose, which will require organisms capable of digesting itAdvantages of Using AlgaeThey do not take up valuable farmland needed for food production. Algae produce 40 times the energy per acre that corn producesThe land the algae grow on can be agriculturally nonproductive as long as it has abundant sunlight.Algae in Biofuel ProductionExperimental algal production sites have even used the carbon dioxide emissions from power plants to accelerate growth. The algae can be harvested on an almost daily basis.Oils squeezed from them can be turned into biodiesel fuel and possibly jet fuel. Typical algae yield 20% of their weight in oil, and some even more.After oil extraction, the remainder, rich in carbohydrates and proteins, can be used to produce ethanol or as animal feed.Tortora G. J., Funke B. R., Case C. L. (2013). Microbiology: An Introduction (11th Ed.). United States of America: Pearson Education Inc.Willey J. M., Sherwood L. M., Woolverton C. J. (2008). Prescott, Harley, and Kleins Microbiology (7th Ed.). New York, NY: McGraw-Hill.Madigan M. T., Martinko J. M., Parker J. (2003). Brock Biology of Microorganism (10th Ed.). Upper Saddle River, NJ: Pearson Education Inc.

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