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Microorganisms? What is Industrial Microbiology?

The field of industrial microbiology may conjure an image of the highest of 21st century high technology, with scientists creating materials suitable for deep space exploration or focused on the cutting edge of genetic engineering. That picture is true in many respects, but, in fact, the field has long been with us.

In essence, industrial microbiology is applied microbiology. It refers to the use of microorganisms to make a product or accomplish a task. Its earliest application, one that probably dates to prehistoric times, was to the production of foods and beverages. Yeast, a naturally-occurring single-celled microorganism, makes the production of beer possible by causing fermentation. Without yeast to convert sugars to carbon dioxide, bread would not rise. While the bakers and brewers of ancient Egypt may not have understood that they were pioneers of industrial microbiology, people have been putting microorganisms to work for thousands of years. Food production is still a major sector of industrial microbiology today, but the field has come to play a part in many endeavors beyond the grocery store. Industrial microbiology is critical to the health care industry, where it is responsible for the production of antibiotics, antitumor agents and hormones. It also plays a key role in the production of replacement body parts through the development of esters appropriate for the special plastics needed for new joints. In addition, we rely on microorganisms for a wide range of medical tests that allow clinicians to identify pathogens and toxins.

The role of industrial microbiology remains important to the arena in which it first appeared. Modern agriculture would not be possible without pesticides and fungicides, substances that often rely on the actions of microorganisms. Organic acids, similar to those used in plastics, are also used to replace acids that occur naturally and that would otherwise be more difficult and expensive to obtain. Citric acid, for example, was once derived only from citrus fruit, but it is now synthesized by industrial microbiologists.

Careers in Industrial Microbiology

Industrial microbiology is a highly technical field, but microbiologists are not exclusively engaged in laboratory work. Microbiologists work in product development and in sales and production management in a variety of fields. They can be found in hospitals, in clinical

laboratories, in testing facilities and in industry, fulfilling different roles depending on their interests and qualifications.

A career in industrial microbiology requires a grounding in science and mathematics. Technical education is a prerequisite, but that education spans everything from an associate’s degree from a technical school to doctoral and post-doctoral qualifications.

People with technical educations short of college can perform a variety of tasks with real-world applications, including:    

Culturing microbes using different reagents and different media Using a broad range of analytical equipment, including centrifuge, gas chromatography and spectrophotometer Handling a broad range of samples in order to identify and isolate microorganisms Isolating DNA and performing experiments in microbial genetics

Although a high school graduate can often find entry level employment in the field, opportunities for advancement are limited for people who have not gone beyond high school. A college diploma may not be a strict necessity, but even a very basic job in microbiology can require specific technical certification. A college degree in a field like biology, biotechnology or microbiology will open many more doors. Senior microbiologists, especially those with broad responsibility for plant or project management, typically have advanced scientific degrees in fields like biology, chemistry, biological or chemical engineering, biochemistry or molecular biology. Regardless of educational level, however, microbiologists work in a remarkably broad range of activities, including:      

the production of fuels that incorporate organic compounds like ethanol waste disposal systems quality assurance and detection of contaminants in the food, pharmaceutical and manufacturing sectors the creation of enzymes and detergents maintenance of freshness in processed foods prevention of deterioration of manufactured products

When energy sources and basic minerals are at a premium, microbiologists are helping to find solutions. They are developing bacteria that assist in releasing oil trapped in rocks and they have developed methods to extract useful minerals from low-grade ores that would otherwise be of little or no commercial value.

The web site of the Society for Industrial Microbiology provides a wealth of resources for current and aspiring microbiologists and offers career guidance for anyone considering entering the field.

The Future of Industrial Microbiology

Industrial microbiologists have already changed the world in fundamental ways. They continue to work in areas that are likely to have profound effects on life in the future. Microbiology has begun to play a new role in environmental management. Using microbes and bio-surfactants, industrial microbiologists have discovered new ways to help contain and clean up dangerous accidents like oil spills. Using bacteria that are at home in exotic environments, they are beginning to develop new tools that can turn contaminants into less harmful substances. Genetic engineering, a field whose potential is just beginning to be tapped, is very much the province of the industrial microbiologist. Genetic manipulation can be broadly applied to agriculture, enabling increased plant and animal resistance to pests and disease and allowing us to select for commercially desirable characteristics. Genetic engineering has an increasingly important, if controversial, role to play in medicine, where the possibilities of genetic identification and manipulation are slowly being uncovered. It offers hope for diseases that have so far proved intractable to conventional treatment.

Another focus of current and future medical research is the use of microorganisms within the body that can be linked to electrode sensors. This highly sophisticated approach opens the possibility of simpler, more accurate and more comprehensive diagnostic procedures. In the midst of these new opportunities, the market for industrial microbiologists continues to grow. According to the Bureau of Labor Statistics, an arm of the United States Department of Labor, the number of jobs in the biological sector as a whole will grow 21 percent from 2008 to 2018. Positions in microbiology itself are expected to increase 12 percent during that period. While the Bureau expects heightened competition in the academic sphere for those who depend on grant funding, it predicts increased demand for scientists able to enlarge on recent developments in basic science by bringing that science to practical applications.

Industrial fermentation and its scope: The intentional use of fermentation by microorganisms such as bacteria and fungi to make products useful to humans. Fermented products have applications as food as well as in general industry.

Food fermentation Ancient fermented food processes, such as making bread, wine, cheese, curds, idli, dosa, etc., can be dated to more than seven thousand years ago. They were developed long before man had any knowledge of the existence of the microorganisms involved. Fermentation is also a powerful economic incentive for semi-industrialized countries, in their willingness to produce bio-ethanol. Pharmaceuticals and the biotechnology industry There are 5 major groups of commercially important fermentation: 1. Microbial cells or biomass as

the

product,

e.g. single

cell

protein, bakers

yeast, lactobacillus, E. coli, etc. 2. Microbial enzymes: catalase, amylase, protease, pectinase, glucose isomerase, cellulase, hemicellulase, lipase, lactase, streptokinase, etc. 3. Microbial metabolites : 1. Primary

metabolites

– ethanol, citric

acid, glutamic

acid, lysine, vitamins, polysaccharides etc. 2. Secondary metabolites: all antibiotic fermentation 4. Recombinant products: insulin, hepatitis B vaccine, interferon, granulocyte colonystimulating factor, streptokinase 5. Biotransformations: phenylacetylcarbinol, steroid biotransformation, etc.

Nutrient sources for industrial fermentation Growth media are required for industrial fermentation, since any microbe requires water, (oxygen), an energy source, a carbon source, a nitrogen source and micronutrients for growth. Carbon & energy source + nitrogen source + O2 + other requirements → Biomass + Product + byproducts + CO2 + H2O + heat Nutrient

Raw material

Carbon Glucose

corn sugar, starch, cellulose

Sucrose

sugarcane, sugar beet molasses

glycerol Starch Maltodextrine Lactose

milk whey

fats

vegetable oils

Hydrocarbons

petroleum fractions Nitrogen

Protein

Ammonia

soybean meal, corn steep liquor, distillers' solubles pure ammonia or ammonium salts urea

Nitrate

nitrate salts

Phosphorus source

phosphate salts Vitamins and growth factors Yeast, Yeast extract Wheat germ meal, cotton seed meal Beef extract Corn steep liquor

Trace elements: Fe, Zn, Cu, Mn, Mo, Co Antifoaming agents : Esters, fatty acids, fats, silicones, sulfonates, polypropylene glycol Buffers: Calcium carbonate, phosphates Growth factors: Some microorganisms cannot synthesize the required cell components themselves and need to be supplemented, e.g. with thiamine, biotin, calcium pentothenate Precursors: Directly incorporated into the desired product: phenethylamine into benzyl penicillin, phenyl acetic acid into penicillin G Inhibitors: To get the specific products: e.g. sodium barbital for rifamycin Inducers: The majority of the enzymes used in industrial fermentation are inducible and are synthesized in response of inducers: e.g. starch for amylases, maltose for pollulanase, pectin forpectinase. Chelators: Chelators are the chemicals used to avoid the precipitation of metal ions. Chelators like EDTA, citric acid, polyphosphates are used in low concentrations.

Sewage disposal In the process of sewage disposal, sewage is digested by enzymes secreted by bacteria. Solid organic matters are broken down into harmless, soluble substances and carbon dioxide. Liquids that result are disinfected to remove pathogens before being discharged into rivers or the sea or can be used as liquid fertilizers. Digested solids, known also as sludge, is dried and used as fertilizer. Gaseous byproducts such as methane can be utilized as biogas to fuel generators. One advantage of bacterial digestion is that it reduces the bulk and odour of sewage, thus reducing space needed for dumping, on the other hand, a major disadvantage of bacterial digestion in sewage disposal is that it is a very slow process.

Phases of microbial growth When a particular organism is introduced into a selected growth medium, the medium is inoculated with the particular organism. Growth of the inoculum does not occur immediately, but takes a little while. This is the period of adaptation, called the lag phase. Following the lag phase, the rate of growth of the organism steadily increases, for a certain period--this period is the log or exponential phase. After a certain time of exponential phase, the rate of growth slows down, due to the continuously falling concentrations of nutrients and/or a continuously increasing (accumulating) concentrations of toxic substances. This phase, where the increase of the rate of growth is checked, is the deceleration phase. After the deceleration phase, growth ceases and the culture enters a stationary phase or a steady state. The biomass remains constant, except when certain accumulated chemicals in the culture lyse the cells (chemolysis). Unless other microorganisms contaminate the culture, the chemical constitution remains unchanged. Mutation of the organism in the culture can also be a source of contamination, called internal contamination.