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An Overview of Scope of Microbiology Lesson: An Overview of Scope of Microbiology Lesson Developer: Riti Mann College/Department: National Institute of Malaria Research Institute of Lifelong Learning, University of Delhi 1 An Overview of Scope of Microbiology Table of Contents Lesson: An Overview of Scope of Microbiology Introduction Microbiology as a subject and its various branches Pure Microbiology Applied Microbiology o Microbes in Environment o Microbes in Human health o Industrial Applications of Microbes o Microbes in Food and Dairy o Biotechnological uses of Microbes Emerging areas of Microbiology o Exomicrobiology o Nanomicrobiology Microbiology: Scope and Future Perspectives Summary Exercise Glossary References Institute of Lifelong Learning, University of Delhi 2 An Overview of Scope of Microbiology Introduction Microbiology as a term exhibits Greek roots: ‘micros’-small, ‘bios’-life and ‘logia’-study, so it refers to the study of small living organisms (microbes). The question is “why study microbes when they are so small and simple organisms”? We have already deliberated on the enormous diversity of microorganisms in preceding lessons. These microorganisms influence our lives in both harmful and useful ways. On one hand they cause diseases, on the other hand they find immense applications in almost all areas of science; whether it be chemical studies, space studies, industrial production and many more. They also affect the environment in which they grow. Thus, Microbiology as a subject provides ample opportunity to know microorganisms and their role in various fields. Microbes provide a number of advantages to be used in industries. They are small in size with high surface area, have short generation time, display the capability of carrying out tremendous variety of reactions and most importantly they can adapt to an array of environments. All these properties help in improving yields, thereby making the process commercially viable. This lesson attempts to explore the scope of Microbiology by discussing various pure and applied branches of microbiology and analyzing role of microbes in various fields like industries, medicine, food and dairy. It also mentions the roles that microbes play in an environment, highlighting on their role in treatment of sewage wastewater. Applied aspects of microbiology such as exomicrobiology and the use of microbes in biotechnology have also been encompassed briefly. Microbiology as a Subject and its Various Branches Microbiology being the study of all those organisms that can’t be seen with naked eye includes viruses, bacteria, many algae, fungi, protozoa etc. Based on their characteristic features, these organisms can be classified as prokaryotes and eukaryotes. However, viruses are neither prokaryotes nor eukaryotes. They are considered as acellular microorganisms as they exhibit living as well as non-living characteristics. Microorganisms vary in size from that of a single atom up to 1mm size (Figure 1). Figure 1: Comparison of the Sizes of Prokaryotes with respect to Eukaryotes and Biomolecules. Source: http://en.wikipedia.org/wiki/Bacteria#mediaviewer/File:Relative_scale.svg (CC) Institute of Lifelong Learning, University of Delhi 3 An Overview of Scope of Microbiology Fascinating facts about microbes One single teaspoon of soil contains 1 billion bacteria, 120,000 fungi and 25,000 algae. There are 10 times more bacteria in the average human’s digestive system than there are cells in the entire body. Microbes generate at least half the oxygen we breathe. Most microbes do not cause disease - less than 5% do. Botox is made from a deadly bacterial toxin, which is used in very small doses to remove wrinkles. The largest organism in the world when measured by area is the Honey Mushroom fungus. It covers a whopping 8.9km2 of a national forest in the USA. Source: http://www.microbiologyonline.org.uk/students/fascinating-facts Additional information The group, led by microbiologist William B. Whitman, estimates the number of bacteria on earth to be five million trillion trillion-that's a five with 30 zeroes after it. Source: http://www.sciencedaily.com/releases/1998/08/980825080732.htm Some important facts about microorganisms are that: The presence of microbes is ubiquitous. They exist on all natural surfaces: soil, water, body of all organisms etc. Some can live in extreme environments like hot springs, frozen sea, etc. Most of the microbes are harmless to us. Instead, they help us by secreting various economically useful metabolites. They keep the biosphere running by performing biodegradation and cycles of carbon, nitrogen, oxygen, sulfur, etc. Microorganisms can also harm humans. They cause diseases in plants as well as animals and food spoilage. It means that microbiology should not only include the structural diversity and classification of microbes but also must encompass all aspects of microbial life i.e. their form, structure, reproduction, physiology, metabolism, distribution, occurrence and economic importance. The knowledge on all these aspects of microbes has been accumulating since last century and has become so vast that microbiological studies have been broadly divided into pure and applied science branches (Figure 2). Some of the pure /fundamental branches include Bacteriology, Virology, Mycology, Phycology etc. The applied branches include Food, Industrial, Medical etc. Institute of Lifelong Learning, University of Delhi 4 An Overview of Scope of Microbiology Figure 2: Pure and Applied Branches of Microbiology. Source: Author Besides these, some other branches are also developing, however, they are still in infancy. Microbiology has closer relationship with Genetics and Biochemistry as it provides convenient use of microbes as genetic models. It is also a major contributor to the fields of recombinant DNA technology and genetic engineering. From this knowledge it can easily be concluded that Microbiology has immense scope due to its ability to control all critical points of fields, like Medical, Industrial, Agriculture, Pharmaceutical, Dairy, Genetics, Nanotechnology etc. Now let’s discuss briefly about these branches of microbiology, focusing on the importance of members from each group. Pure Microbiology Virology refers to the study of viruses, very small infectious agents that can only be observed under electron microscope. Some interesting facts about viruses are: Their approximate size ranges between 20 to 300 nm, i.e. they can pass through the pores of filters used for excluding bacteria (usual pore size-2μm). Viruses are obligate intracellular parasites. They require live cells to grow and cannot be cultured in artificial media. Viruses use host machinery for generation of energy and protein synthesis. Viruses have either DNA or RNA as their genetic material, but no virus has both of these. Name the largest known virus? French researchers have recently reported a virus that is 1μm long. They named this virus as ‘Pandoravirus’ (In greek mythology, Pandora’s box is a large jar which contained all the evils of the world). Before the discovery of Pandoravirus, Mimivirus (Mimicking microbe) was the largest Institute of Lifelong Learning, University of Delhi 5 An Overview of Scope of Microbiology known virus with a size of 400-500 nm. Mimivirus was accidently discovered in amoeba Acanthamoeba polyphaga. An infectious virus is termed as ‘virion’. Baltimore classification has placed viruses into seven groups, as described in Figure 3. Figure 3: Baltimore Classification Source: http://upload.wikimedia.org/wikipedia/commons/a/a5/VirusBaltimoreClassification.svg (CC) Bacteriophages (Bacteria eaters)/ Bacterial viruses/ Phages are the viruses that are used widely in genetic research. Bacteriology is the branch of microbiology that deals with another group of microorganisms- Bacteria. Morphologically, bacterial cells are spherical (cocci), rod like (Bacilli) or helical. These basic shapes of bacteria are usually found arranged in groups: pairs, clusters, trichomes and filaments. All these shapes and arrangements of bacteria have been illustrated in Figure 4. Figure 4: Morphologies and Arrangements of Bacterial Cells. Institute of Lifelong Learning, University of Delhi 6 An Overview of Scope of Microbiology Source: http://upload.wikimedia.org/wikipedia/commons/6/69/Bacterial_morphology_diagram.sv g (CC) Phycology is the study of algae (singular-alga), which are microorganisms containing chlorophyll and are photosynthetic. They occur in almost all habitats. They exist in varied forms, ranging from small, single-celled (flagellates) to complex multicellular (kelps). Algae have great economic importance. Agar, which is used as a solidifying agent in microbiological media, is derived from algal cell wall. Carrageenan (used as stabilizer in foods) and alginic acid (used for providing smooth consistency to ice cream) are some of the other products of economic value obtained from algal cell walls. Some species of algae are also used as food. For instance, the red algae Porphyra is used as a food in Japan named as “nori”. Mycology is the study of fungi. Fungi are a group of eukaryotic organisms that do not have chlorophyll and are heterotrophic. They are of immense value to industrialists, as they are responsible for producing a large number of commercially valuable products. They play significant role in brewing of beer, wine making, production of antibiotics and many more. The most common example is the use of yeast Saccharomyces in fermentation of beer and wine. Fungi are also identified as the causative agents of diseases in plants, humans and other animals. For instance, Candida albicans causes candidiasis of skin and mucous membranes. Protozoology is science of protozoa (Greek protos and zoon means ‘first animal’), the eukaryotic protists. They are usually unicellular and free living. Protozoa that eat bacteria help to maintain ecological balance in aquatic environments as well as in wetlands. However, some protozoa may be parasitic. Out of the four species of Plasmodium protozoa (Plasmodium falciparum, P. vivax, P. ovale and P. malariae), the causative agents of malaria in humans are P. falciparum and P. vivax. Immunology deals with immune system and the response generated by it against various disease causing microorganisms. Microbial Physiology provides insight into the physiology of microorganisms with respect to their nutritional requirements, growth conditions, and metabolic reactions. Applied Microbiology Microbes in Environment Environment includes everything (biotic as well as abiotic components) that surrounds an organism. There is a hierarchy of living systems within the biosphere, which is described in Figure 5. Organism Population Community Ecosystem Landscape Biome Biosphere Figure 5: Hierarchy of Living Systems. Source: Author Institute of Lifelong Learning, University of Delhi 7 An Overview of Scope of Microbiology Similar microorganisms form assemblies known as ‘populations’. The population of microorganisms when interacts with another population of different kind of microorganisms is termed as ‘community’. A.G Tansley proposed the term ‘ecosystem’ in 1935. It is a functional unit comprising of organisms interacting among themselves, with other organisms and with their physical environment. These interactions are studied either under Microbial Ecology or under Environmental Microbiology (Figure 6). The benefits of studying these two subjects can be illustrated by a few examples given below. Figure 6: Microbial Ecology and Environmental Microbiology Source: Author Image Source: http://commons.wikimedia.org/wiki/File:Ananda_Mohan_Chakrabarty_-_Kolkata_200911-08_3037.JPG (CC) Additional Information Thomas Brock discovered the bacterium Thermus aquaticus. Thermus aquaticus is known all over the world as source of Taq polymerase, an enzyme used in Polymerase Chain Reaction (PCR). Ananda Mohan Chakrabarty is an Indian American microbiologist, who developed the genetically engineered bacteria Pseudomonas putida. This bacterium is capable of degrading a number of hydrocarbons and therefore, finds application in bioremediation. A patent has also been granted to Prof. Chakrabarty for this genetically engineered bacterium. Institute of Lifelong Learning, University of Delhi 8 An Overview of Scope of Microbiology Microbes while interacting with each other, with other higher organisms and with their environment; play an array of beneficial roles. They contribute to the functioning of ecosystems by maintaining ecological balance. Microorganisms are involved in biogeochemical cycling; they degrade and solubilize many useful minerals that are otherwise not available to organisms. Microorganisms attach to various surfaces and form biofilms. These consist of layers of microbial cells adherent to the surfaces. Biofilms are important to study, as they relate to almost all areas of microbiology. The most appropriate example is the formation of dental caries as a result of biofilm formation by microorganisms like Lactobacilli and Streptococci. Pathogenic microorganisms like Pseudomonas aeruginosa and Staphylococcus epidermidis form biofilms. This confers them resistance to antibiotics, thereby, making their treatments even more difficult. There is a direct consequence of the formation of microbial film/biofilm on the surface of water distribution pipes. It causes severe economic losses. This process of corrosion carried out by the microbial population is called as ‘Biocorrosion’. The buried pipes are usually coated to prevent contact between the metal surface, water and soil microbial population; thereby preventing biocorrosion caused by microbial films. Microorganisms play both beneficial and detrimental roles in the mining and mineral processing of metals. The metabolic activities and capabilities of the microbes are exploited to improve the recovery of metals and petroleum from the environment. Sulfur oxidizing Thiobacilli are employed commercially in the process of bioleaching- recovery of copper, uranium and other metals. Microbes are also useful in the process of waste management. Waste obtained from various sources like household, industries, etc. can either be solid waste or liquid waste. Solid waste is managed by methods like Composting, Landfills, Incineration, etc. Liquid waste or wastewater is treated in a sequential manner, starting with Primary/Physical treatment, followed by Secondary/Biological treatment and at last Tertiary treatment. In primary treatment, particulate material is removed by passing the wastewater through grids of decreasing pore size, as shown in Figure 7. Primary treatment also includes the process of settling in tanks (Figure 8), which further removes the particulate material. Institute of Lifelong Learning, University of Delhi 9 An Overview of Scope of Microbiology Figure 7: Schematic Representation of the Process in which Wastewater is Passed through a Series of Grids of Decreasing Pore Size. This process separates out the particulate material. Source: Author Figure 8: Settling Tank. Source: http://en.wikipedia.org/wiki/Sewage_treatment Secondary or Biological treatment involves use of microorganisms. After this treatment, BOD (Biochemical Oxygen Demand) is reduced by 90-95% as compared to the original BOD of wastewater. Microorganisms commonly used are filamentous bacteria such as Sphaerotilus and Thiothrix. Secondary treatment of liquid waste can be treated either aerobically or anaerobically. Figure 9 lists different types of aerobic and anaerobic treatment methods that are available. The important features of all these treatment methods along with their pictures are given in Table 1. Institute of Lifelong Learning, University of Delhi 10 An Overview of Scope of Microbiology Figure 9: Types of Liquid Waste Treatment. Source: Author Table 1. Different Types of Aerobic and Anaerobic Treatment Methods for Liquid Waste Source: Author Aerobic Treatment Methods (A) Aerobic Tanks These are open tanks in which proper aeration is provided for activating the natural microflora of sewage water. Institute of Lifelong Learning, University of Delhi 11 An Overview of Scope of Microbiology (B) Trickling Filter Consists of a fixed bed of rocks over which sewage flows downward and causes a layer of microbial slime (biofilm) to grow, which ultimately covers the whole bed. A boom type sprinkler continuously revolving over the bed distributes sewage. Microbes present in the biofilm then act on the trickling wastewater. (C) Biological Disks Consists of a series of closely spaced, parallel discs made up of plastic. These discs are mounted on a rotating shaft which is supported just above the surface of the waste water. Microorganisms grow on the surface of the discs where biological degradation of the wastewater pollutants takes place. Anaerobic Treatment Methods (D) Septic Tank Initially the sedimentation of suspended organic matter occurs, followed by decomposition of organic matter by anaerobic or facultative anaerobes. (E) Imhoff Tank It is a two-chamber system, which permits the development of better effluent. Decomposition takes place by anaerobic and facultative anaerobic microorganisms. (F) Anaerobic Digester Complex organic matter degradation occurs releasing carbon dioxide and hydrogen. This carbon dioxide is then reduced to methane, which can be used for energy Institute of Lifelong Learning, University of Delhi 12 An Overview of Scope of Microbiology generation. Final product is a mixture of methane (70%) and carbon dioxide (30%). Source of images: (A) http://en.wikipedia.org/wiki/Aerated_lagoon - mediaviewer(CC) (B) http://commons.wikimedia.org/wiki/File:Trickling_filter_bed_2_w.JPG (CC) (C) http://commons.wikimedia.org/wiki/File:ACAI_DEPURACION__EDAR_BIODISCOS.jpg (CC) (D) http://en.wikipedia.org/wiki/Septic_tank - mediaviewer(CC) (E) http://en.wikipedia.org/wiki/Imhoff_tank#mediaviewer (CC) (F) http://en.wikipedia.org/wiki/Anaerobic_digestion#mediaviewer (CC) Tertiary treatment removes mineral nutrients. This involves the process of disinfection, which is done by chlorination or by ozonation. Chlorination is an inexpensive method, whereas ozonation is a more effective method as compared to chlorination. Aerobiology is also an applied aspect of microbiology that deals with the study of microorganisms suspended in air. Other than the living microorganisms, it also includes the study of various air-borne microbiological agents such as endospores, fungal spores, etc. Atmosphere provides a very hostile environment for microorganisms and therefore the number of microbes found in air is small as compared to that in soil or water. Some microorganisms that have been reported to be present in atmosphere include: Fungi- Alternaria, Aspergillus, Fusarium, Penicillium Bacteria- Corynebacterium, Flavobacterium Algae- Diatoms Some yeasts have also been reported to be present in atmosphere. Additional Information Atmospheric particles, such as mists or dust, of size within μm range are referred to as ‘Bioaerosols’. Clouds, which provide even harsher conditions to microbes, have also shown the presence of bacteria. Infact, clouds serve as a means by which microbes are transported to long distances. Detailed information about the significance of microbes in environment is available in the lesson ‘Role of Microbes in Environment’. Microbes in Human Health Microbes in humans cause a number of diseases. Examples of important diseases are tuberculosis (Mycobacterium tuberculosis), leishmaniasis (Leishmania sp.), AIDS (HIVHuman Immunodeficiency Virus), etc. Institute of Lifelong Learning, University of Delhi 13 An Overview of Scope of Microbiology Microbes are a good source of antibiotics, which for a long time have been the mainstay of our defense against many infections. Preparing an antibiotic using chemical synthesis processes is extremely expensive, so microorganisms are used by pharmaceutical industries for their production. In addition to being a good source of antibiotics, microbes are also important contributors in other aspects of health sciences. For instance, viruses are being used as tools in gene therapy; they help in easy delivery of gene to the target cell. Industrial Applications of Microbes The entire industrial process of manufacturing and marketing a product can broadly be divided into the following major steps: Preparation/Upstream processing, Production/Fermentation, Extraction, Downstream processing that also includes marketing. Microbes are used immensely at the step of fermentation (Table 2). They may have to be manipulated genetically in order to improve product yield. Table 2: Microbes Commonly Used in Industries Source: Author Industry Enzymes production Citric acid production Microorganisms used Asperillus oryzae (Amylase), Saccharomyces cerevisiae (Invertase), Bacillus subtilis (Amylase), Trichoderma reesei (Cellulase), Rhizomucor pusilley (Proteases) Aspergillus niger Alcohol production Saccharomyces cerevisiae, Candida shehatae, Zymomonas mobilis Lactic acid production Lactobacillus lactis, Leuconostoc mesenteroides Antibiotic production Penicillium sp. (β-lactam drugs), Streptomyces nodasus (Amphotericin B) Amino acid production Corynebacterium glutamicum (Glutamate) Microbes in Food and Dairy Microbes are used for production of a variety of food products and sometimes they are themselves used as food (SCP). Some of the dairy products along with the microorganisms used in their production are given in Table 3. Unknowingly, we ingest various microbes on daily basis. For instance, the bread we take daily is prepared by using yeast culture and the curd that we eat is full of Lactobacilli. So without even realizing, we are continuously interacting with microbes. Table 3: List of Some Dairy and non-dairy Products and the Microorganisms Involved in Their Production Source: Author Dairy Product Microorganisms Involved Dahi Lactococcus lactis, Streptococcus thermophiles Acidophilus milk Lactobacillus acidophilus Institute of Lifelong Learning, University of Delhi 14 An Overview of Scope of Microbiology Cultured buttermilk Lactococcus lactis, Leuconostoc citrinovorum Bulgarian buttermilk Lactococcus bulgaricus Yoghurt Lactococcus delbrueckii, Streptococcus thermophiles Cheese Cheddar cheese Lactococcus lactis Cottage cheese Lactococcus lactis, Leuconostoc spp. Swiss cheese Streptococcus thermophiles, Propionibacterium shermanii Camembert cheese Penicillium camembertii, Lactococcus lactis Roquefort cheese Penicillium roquefortii, Lactococcus lactis Non-dairy Product Microorganisms Involved Kefir Lactococcus lactis, Lactobacillus brevis Kumiss Lactobacillus bulgaricus, Torula sp. Pickels Lactobacillus plantarum, Pediococcus cerevisiae Pediococcus halophilus, Pediococcus soyae Soy sauce Besides their role in production of foods, microorganisms are themselves used as dietary supplements in the form of SCP (Single Cell Protein). C.L. Wilson coined this term in 1966. SCP refers to the microbial biomass or proteins obtained from them, which are used as food and feed additives. Microorganisms commonly used as SCP are: algae (Chlorella, Spirulina), yeasts (Candida tropicalis, Candida utilis), bacteria (Cellulomonas, Nocardia), filamentous fungi (Morchella deliciosa, Fusarium monoliforme). Further detailed information about the various applications of microbes in food industry is available in the lesson’ Application of Micro-organisms in Food and Dairy Industry’. Biotechnological Uses of Microbes Microorganisms, especially bacteria and yeast, serve as factories for propagation of plasmids that have foreign gene (from other organism) cloned into them. Apart from this, genetic engineering has facilitated the process of manipulating the genetic information of a microbe, in such a way that microbes can now be used for production of industrially and pharmaceutically valuable products at high scale. The first and the best use of a microbe for synthesis of recombinant product is that of HUMULIN. Humulin is the recombinant human insulin produced by cloning the human insulin gene into a laboratory strain of E. coli. To list out few biotechnological applications of microorganisms: Gene therapy: Treatment in which a normal or genetically altered gene is inserted into the cells so as to compensate for the missing or nonfunctional gene. For example, for treating SCID (Severe combined immunodeficiency disease), viral vectors mainly phages are used as tools for delivering normal or altered gene into the cells (Figure 10). Institute of Lifelong Learning, University of Delhi 15 An Overview of Scope of Microbiology Figure 10: A Newspaper Clipping Showing Use of Virus in Gene Therapy for Curing Blindness. Source: Times of India dated Dec. 10, 2014 Microbes as Biopesticides: Transgenic plants expressing B. thuringiensis (Bt) toxin gene have been developed, in which Bt gene has been spliced into plant genes using Ti plasmid of Agrobacterium tumifaciens. These include Bt-corn, Bt-potato, Bt-cotton and Bt-brinjal. Microbes in Bioremediation: Genetically engineered bacterium- Pseudomonas putida, is capable of degrading a number of hydrocarbons and is used for removing oil spills. Microorganisms in Fermentation: Recombinant microbes with foreign gene cloned or with overexpression of their indigenous genes are currently being used at large scale in industries. For example; for production of antibiotics like streptomycin, enzyme production and many more. Mutant strains of microorganisms displaying high levels of expression are also being used for overproduction of industrially valuable products. Microbial Sensors: The most common and natural biosensors are lichens, which do not grow or their growth is retarded due to the presence of pollutants in environment. Microbial biosensors have also been applied in detection of Biochemical Oxygen Demand (BOD). Emerging Areas of Microbiology Exomicrobiology Exomicrobiology (Figure 11) is a newly emerging field that includes the study of microorganisms in space and space like environment (exposing microorganisms to very harsh environment, like that in space). Institute of Lifelong Learning, University of Delhi 16 An Overview of Scope of Microbiology Astrobiology SPACE MICROBIOLOGY Exobiology/ Extra- terrestrial microbiology Cosmology Figure 10: Space Microbiology- The study of microbes in outer space or space like conditions. Source: Author Microbiological studies are carried out directly in the space environment or by using facilities that simulate the conditions of outer space. Microorganisms serve as the most appropriate living creatures, whose studies provide valuable information about the effect of space environment on living systems. These studies further open the doors for possibility of life in outer space. Nanomicrobiology Nanomicrobiology is study of microbiological samples by applying atomic force microscopy (AFM). It provides three-dimensional image of the cells and membranes at nanoscale which helps understand changes in microbial surfaces on interaction with drugs and other chemicals. Something to Ponder about…. The field of microbiology has achieved its present status only after many and many novel discoveries by innumerable scientists. But now the question arises- who should be called as the ‘Father of Microbiology’? This is an interesting debatable topic within the scientific community, that who should be crowned as the Father of ever-expanding field of Microbiology. There are a few highlighted candidates for this place: Anton van Leeuwenhoek who invented the microscope and opened the world of Institute of Lifelong Learning, University of Delhi 17 An Overview of Scope of Microbiology invisible microbes. Thus, he was the one who initiated the field of microbiology. Some say that Robert Hook should be called as the Father of Microbiology, as he reported the first microbiological observation of fruiting bodies of molds. While in the viewpoint of some others, Louis Pasteur should be the Father of Microbiology. He introduced the process of pasteurization, made significant contributions to the beer fermentation process, disproved the theory of Spontaneous generation and most importantly introduced the sterilization flask. Culture plates that we commonly use in our laboratories for keeping the media sterile, are based on the same principle as was introduced by Louis Pasteur in his flask. Robert Koch, because of his pioneering work in the field of bacteriology, can also be crowned as the Father of Microbiology. Who do you think should be the Father of Microbiology???? And the debate continues …… Microbiology: Scope and Future Perspectives (What to do being graduates in this field????) Throughout the lesson we discussed about the pure and applied branches of microbiology. In this entire discussion, the applied aspects of microbiology have been dealt focusing mainly on the use of microorganisms in diverse areas. But this discussion is incomplete for a student who has recently started in this field and wants to know the future possibilities. For him/her, the main motto of reading this lesson is to know the areas towards which he/she can shape his/her career. Here comes the need of describing the scope in detail. Lets first have a look at below mentioned websites on career opportunities in Microbiology to get basic idea of what can be done. https://www.youtube.com/watch?v=nElhiCyXJZA http://timesofindia.indiatimes.com/home/education/news/Micro-world-Careeropportunities-in-microbiology/articleshow/20624271.cms http://www.biotechnologyforums.com/thread-1676.html What All can be Done? Microbes find applications in many a number of places and perform tasks that are just impossible to carry out without them. Even if the tasks are possible, they are not economically feasible. For instance, use of microorganisms for production of antibiotics. Antibiotics can also be manufactured by chemical processes (by chemists) but the cost is extremely high. So this is one area (pharmaceuticals) where microbiologists can work. They are the ones who not only can apply microorganisms in production but also can even genetically modify the microorganisms for making the procedure economically viable. Not just pharmaceuticals, microorganisms are used in production of numerous food products. Microorganisms provide special flavor and texture to these food products. For example; baking, brewing, cheese preparation and many more. You all must have heard about the newly available health drink in Indian market, Yakult. This is a fermented milk product containing bacterium Lactobacillus casei strain Shirota. Institute of Lifelong Learning, University of Delhi 18 An Overview of Scope of Microbiology Figure 11: Yakult Source: Author For further information on Yakult, refer: http://www.yakult.co.in/ Similarly, there are so many other food products prepared using microorganisms. Microbiologists find these kinds of industries really appealing to work with. Did you know?? The number of microorganisms known to be present on earth is far below their actual number. We are unable to identify these unknown microorganisms because of a number of reasons, few of them are: Lack of machinery and technology Inability to reach inaccessible/extreme areas Difficulty in culturing microorganisms There are a large number of microorganisms that cannot be cultured under laboratory conditions. For studying these microbes, a recent concept termed ‘Metagenomics’ has been introduced. It is a study involving isolation of genomic contents of all the members of a community and their analyses using various techniques like DGGE (Denaturing Gradient Gel Electrophoresis), thereby, bypassing the need for culturing the microbes. Microbiologists are also an integral part of ever expanding enzymes, acids, and vitamins producing industries. It is so common to manipulate microbes for their production and further to scale up the process using modified strains. Microbes, as we all know, play innumerable beneficial roles but some microorganisms are also known to be harmful. They actually cause diseases in plants as well as in animals. For controlling these diseases, rapid and cheap diagnostic methods should be known in addition to their treatment options. Microbiologists play key roles in developing both of these. https://docs.google.com/file/d/0B828qi2N1qG-S3FpMnhLcXN6UHM/edit?usp=drive_web Microbiology is such an inter-related subject that a person experienced in this field is well equipped to carry out research in any area of his/her interest. To name a few; structural, molecular, biochemical, immunological, genomic and scale up studies. There are innumerable numbers of institutions, universities and organizations that are working on various aspects of microbiology. For details about the research institutes in India, refer to the link: http://www.indiabioscience.org/jobs/research-institutes. However, the list may not be considered complete. There are so many newly emerging areas where microbiologists genuinely have a place. Lets say the area of epidemiological studies, which is so urgent in present day scenario Institute of Lifelong Learning, University of Delhi 19 An Overview of Scope of Microbiology where everyday new pathogens are emerging and we actually don’t know their origin or the mode by which they spread. In short, it can be said that ‘Microbiology as a word has everything to say about it but even then the definition is incomplete without excavating its horizons’. Summary Microbiology encompasses the study of prokaryotes (Bacteria, archaea, etc.), eukaryotes (protozoans) and acellular organisms-viruses. Because of the immense roles that microbes play, the broad field of microbiology is divided into pure and applied branches. The applied aspects of Microbiology include Environmental Microbiology, Industrial Microbiology and so on. Aeromicrobiology is the branch that deals with the study of various air-borne pathogens. This field finds relevance while studying hospital-acquired infections, which are usually air-borne. Exomicrobiology and Nanomicrobiology are newly emerging areas of Microbiology. Microbes in environment are involved in many a number of jobs. They keep the ecosystem running by maintaining ecological balance. They are involved in the process of degradation and mineral cycling, solubilizing mineral nutrients and making them available to other organisms. Various methods have been developed for treatment of sewage water. They are broadly divided into aerobic and anaerobic methods. Aerobic methods include Aerobic tanks, Trickling filter and Rotating Biological Disks. Anaerobic methods include Septic tank, Imhoff tank and Anaerobic digester. Microbes are causative agents of a variety of diseases in humans, but are also the source of life saving antibiotics. Industrial production of many products is not economically viable without the use of microorganisms. Therefore, since a long time, industries have been using microbes for production of antibiotics, amino acids, beer and many more products. Exercise Short answer questions 1. Define the following terms: Virology Bacteriology Phycology Mycology Protozoology Aeromicrobiology Exomicrobiology Biocorossion Humulin Institute of Lifelong Learning, University of Delhi 20 An Overview of Scope of Microbiology 2. Explain briefly the role of microbes in mineral recovery. 3. Give an example of microorganism used for production of the following: Amylase enzyme Citric acid Lactic acid Amphotericin B Dahi Acidophilus milk Yoghurt Swiss cheese Roquefort cheese Kefir Kumiss Soysauce SCP 4. Write a short note on ‘SCP’. 5. Write briefly about Exomicrobiology. 6. Differentiate between Microbial Ecology and Environmental Microbiology. Long answer questions 1. Explain the harmful effects of biofilm formation. 2. Explain the process of Secondary sewage treatment, mentioning about its different methods. Fill in the blanks 1. Viruses are considered as ______ microorganisms as they exhibit both living and non-living characteristics. 2. The presence of microbes is ______. 3. Viruses are ______ intracellular parasites. 4. ______ classification has placed viruses into seven groups. 5. The red algae ______ is used as a food in Japan. 6. The causative agent of malaria is ______. Answers 1. 2. 3. 4. 5. 6. acellular ubiquitous obligate Baltimore Porphyra Plasmodium protozoa Glossary Antibiotics: Antibiotics are agents that either kill or retard the growth of microorganisms. For bacteria, they are termed as Bacteriostatic (hampers the growth) or Bactericidal (kills the bacteria). Bioleaching: The process of extraction of an element from its ore by the use of microorganisms. Institute of Lifelong Learning, University of Delhi 21 An Overview of Scope of Microbiology Biosphere: The living creatures on earth and their environment when combined, is termed as biosphere. Candidiasis: Fungal infection caused by Candida sp. Infection is usually caused on skin and sometimes in vagina. Cosmology: The science that answers the questions of origin of universe, its evolution and predicts about its future. Downstream Processing: The industrial process after the actual fermentation that includes purification, packaging and marketing. Facultative Anaerobes: Microorganisms that by nature are aerobic but can also survive by generation of energy if oxygen is absent. Gene Therapy: It is an approach in which genetic material of an organism is targeted so as to treat a disease. Upstream Processing: The steps prior to start of an industrial fermentation process that includes media optimization, conditions standardization etc. References Books Ronald M. Atlas and Richard Bartha; Microbial EcologyApplications, Fourth Edition (2009); Pearson Education. Fundamentals and Prescott, Harley and Klein; Microbiology, Seventh Edition (2008); Mc Graw Hill Education. Michael J. Pelczar, E.C.S. Chan, Noel R. Krieg; Microbiology, Fifth Edition (2007); Tata Mc Graw Hill Edition. Web links http://www.youtube.com/watch?v=72gwwyz2ZWg http://www.nature.com/scitable/topicpage/discovery-of-the-giant-mimivirus14402410 http://www.sciencedirect.com/science/article/pii/S095656631000607X https://www.educationnest.com/digistore/products/6329-microbiology/169917emerging-scope-of-microbiologist/966 Institute of Lifelong Learning, University of Delhi 22