All the organisms in this world are composed of cells which could either have a prokaryotic or a eukaryotic configuration. All bacteria and some other organisms which belong to the group ‘archaea’ are unicellular organisms that show prokaryotic configuration (Todar, 2000).
All the other organisms (unicellular or multicellular) on this earth are composed of eukaryotic cells. Since most prokaryotic organisms are bacteria, the two terms are often used as synonyms. The differences between prokaryotic cells and eukaryotic cells as described by Todar (2000) are as follows: the prokaryotic cells have no well defined nucleus.The genetic material inside a prokaryotic cell (shown in figure 1) is in form a circular DNA which is condensed to form a nucleoid, and is not enclosed by a nuclear membrane.
Eukaryotic cells, on other hand contain a well defined nucleus which is surrounded by a nuclear membrane and contains genetic material in form of chromosomes. Other membrane bound cytoplasmic organelles like mitochondria, lysosomes, golgi apparatus etc which are normally present in a eukaryotic cell are not present inside a prokaryotic cell.Prokaryotic cells contain a cell wall which is not present in eukaryotic animal cells (may be present in eukaryotic plant cells). Though prokaryotic organisms, typically, bacteria have been largely implicated as the causative agent of variety of diseases in human beings, they have also proven useful to the mankind in many ways, in terms of human health as well in fields of biotechnology, genetic engineering, food and agricultural industry, as described below.There has been increasing awareness regarding the beneficial effect of bacteria for human health. This has led to the introduction of ‘probitics’ and pre-biotics.
‘Probiotics’ refers to useful, live bacteria consumed in small amounts for their potential benefits on health. Pre-biotics refer to certain substances which are consumed in order to promote the growth of commensal bacteria in the body with the aim of obtaining increased benefits on human health (Canfield, 2006).In the United States, the probiotic bacteria are available in form of conventional dairy foods supplemented with these bacteria or as dietary supplements in the form of capsules, powder or tablets (Sanders, 2000). Improving Body’s Immunity Our bodies are inhabited by billions and trillions of harmless bacteria also known as commensals. These harmless bacteria prevent the body against invasion by the pathogenic bacteria.Use of pro-biotic substances appears to be useful in cases where there is disruption of colonizing microorganisms in the body due to old age, treatment with antibiotics, immuno-suppression or to increase the immunity of the body against antibiotic resistant pathogens.
Since the prokaryotes present in probiotics help in bolstering the intestinal immunity, they may be helpful in fighting against inflammatory bowel disease like chron’s disease and ulcerative colitis (Sanders, 2000). The exact mechanism through which these organisms increase immunity is not yet understood.Protection against colon cancer Bacteria present in our colon are capable of converting the digestion resistant fiber present in our diet into short chained saturated fatty acids like acetate, butyrate and propionate. Butyrate is supposed to provide protection against development of colon cancer (Canfield, 2006). Management of Lactose intolerance People suffering from lactose intolerance are deficient in the enzyme called lactase.
The enzyme lactase is responsible for converting lactose (milk sugar) into glucose and galactose which are simple sugars and can be easily absorbed by the body.Deficiency of the enzyme lactase causes lactose to move to the intestines in an undigested state where it is converted by intestinal bacteria into hydrogen and carbon dioxide. This can result in producing abdominal discomfort and symptoms like abdominal cramps, bloating etc. By consuming supplements containing lactase-producing lactobacillus bacteria, the symptoms of lactose intolerance can be decreased (Canfield, 2006).
Protection against vaginal infections in women A health vaginal tract contains high populations of hydrogen peroxide producing lactobacilli (shown in figure 2).These bacteria help in maintaining the vaginal pH below 5. 0, thus providing protection against development of vaginal infections like candidiasis, trichomoniasis, bacterial vaginosis etc (Sanders, 2000). Vitamin synthesis Bacteria like E.
coli present in human colon are involved in synthesis of vitamins like vitamin B12, folic acid, biotin and K, which may be used by the host (Canfield, 2006). A bacteria called clostridium butyclicum is used for commercial preparation of riboflavin (Canfield, 2006).Uses of Prokaryotic Organisms in Biotechnology and Industry Dairy and Food industry Bacteria, especially the lactic acid producing lactobacillus are specially used in preparation of food stuffs involving the process of fermentation e. g. yogurts, cheese, breads, fermented soy sauces, pickles, wine, vinegar etc (Best, 1990). Genetic engineering and bacteria Genetic engineering involves introduction of pieces of DNA into a host cell, (usually a bacterial cell) with help of agents called vectors.
The foreign DNA gets incorporated with the bacterial DNA and can be used in production of commercially useful products e. g. recombinant human insulin (used for treating diabetes), human growth hormone (used for treating pituitary dwarfism. ), interferons and antibodies (which help in fighting against infections and cancers) (Steinberg & Raso, 1998). Use in Agriculture and farming Prokaryotes like symbiotically associated bacteria are able to biologically convert nitrogen gas present in the atmosphere into ammonia which helps in enriching the soil and promotes optimal growth of plants.
Prokaryotes also help in decomposition of organic matter into compost which serves as a rich source of nutrition for the plants and is also free from the toxic effects produced by chemical fertilizer (Cumino, Marcozzi, Barreiro & Salerno, 2007). The process of genetic engineering is also applied to agriculture in order to produce better quality crops (Steinberg & Raso, 1998). Bioremediation Bioremediation is the process in which bacteria and other organisms are used to convert undesirable substances (industrial waste, sewage etc) into harmless substances.Bacteria are used to decompose sewage waste into a harmless soluble substance known as sludge. In the process of decomposition methane gas is released which is used as a source of energy.
Bacteria are also capable of digesting hydrocarbons present in petroleum and are used to clean up oil spills. Thus bacteria also play a role in solving the problem of water and soil pollution (Abed et al, 2002). Conclusion Despite the fact that bacterial organisms are a cause of numerous human diseases, use of certain bacterial strains, in form of probiotic agents is steadily on an increase due to their potential health benefits.However much research still needs to be done in this field to delineate the exact benefits of prokaryotic organisms on human health.
The exact mechanism of action and actual interaction between these organisms and human body has yet to be discovered. Besides the useful effect of prokaryotes on human health they hold a significant economic importance too, by playing a valuable role in biotechnology, genetic engineering and food and agriculture industry. Prokaryotes also have a potential to save the world against the harmful effects of pollution.Referenceshttp://www.ualberta.ca/~csps/JPPS1(2)/biotech.htmhttp://textbookofbacteriology.net/bacteriology.htmlhttp://textbookofbacteriology.net/structure.htmlhttp://textbookofbacteriology.net/normalflora.html
