MicroorganismsBy Hira Nadeem

Class 6th

MicroorganismsAn organism that is too small to be seen by the unaided human eye.It is also known as microbes or microscopic organisms.The existence of microscopic organisms was discovered during the period 1665-83 by two Fellows of The Royal Society, Robert Hooke and Antoni van Leeuwenhoek. In Micrographia (1665),

Types of microorganismMicroorganism are divided into seven types:

1) Bacteria2) Archaea3) Protozoa

4) Algae5) Fungi

6) Viruses8) Multicellular

BacteriaBacteria are unicellular organisms. The cells are described as prokaryotic because they lack a nucleus. They exist in four major shapes: bacillus (rod shape), coccus (spherical shape), spirilla (spiral shape), and vibrio (curved shape). Most bacteria have a peptidoglycan cell wall; they divide by binary fission; and they may possess flagella for motility.

Archaea•Archaea or Archaebacteria differ from true bacteria in their cell wall structure and lack peptidoglycans. They are prokaryotic cells with avidity to extreme environmental conditions.

Fungi

Fungi (mushroom, molds, and yeasts) are eukaryotic cells (with a true nucleus). Most fungi are multicellular and their cell wall is composed of chitin. They obtain nutrients by absorbing organic material from their environment (decomposers), through symbiotic relationships with plants (symbionts), or harmful relationships with a host (parasites).

Protozoa

• Protozoa are unicellular aerobic eukaryotes. They have a nucleus, complex organelles, and obtain nourishment by absorption or ingestion through specialized structures. They make up the largest group of organisms in the world in terms of numbers, biomass, and diversity.

Algae

Algae, also called cyanobacteria or blue-green algae, are unicellular or multicellular eukaryotes that obtain nourishment by photosynthesis. They live in water, damp soil, and rocks and produce oxygen and carbohydrates used by other organisms. It is believed that cyanobacteria are the origins of green land plants.

Viruses

• Viruses are no cellular entities that consist of a nucleic acid core (DNA or RNA) surrounded by a protein coat. Although viruses are classified as microorganisms, they are not considered living organisms. Viruses cannot reproduce outside a host cell and cannot metabolize on their own. Viruses often infest prokaryotic and eukaryotic cells causing diseases.

Multicellular

• A group of eukaryotic organisms consisting of the flatworms and roundworms, which are collectively referred to as the helminths. Although they are not microorganisms by definition, since they are large enough to be easily seen with the naked eye, they live a part of their life cycle in microscopic form.

Kinds of microorganisms

There are two types of microorganism1) Dangerous microorganisms2) 2) Useful microorganisms

Dangerous microorganisms

Bacteria are disease-causing pathogens and some of them cause deadly illness and disease in human beings. Each year millions of people die because of these microscopic living beings

Dangerous microorganismsE. Coli

the most common bacteria found in Human body. Infamous E.coli inhabits in the intestine of the healthy individuals. Some of their strains are detrimental to human beings especially to very young or immune compromised or elderly people. One of the rare strain of E. Coli results in bleeding in the intestine

Dangerous microorganisms

Clostridium BotulinumBotulinum toxin attacks the nervous system of the affected individual and causes trouble in respiration, swallowing, speaking, vision and causes overall physical weakness. This results in an inability to breathe since the toxin causes paralysis in the breathing muscles and the person gradually dies

Dangerous microorganisms

SalmonellaThis is a deadly strain of bacteria and affects in two forms, the enterica, and the typhi. The well-known Typhoid fever is caused by Salmonella typhi. The last year alone it was responsible for 216,000 deaths. The contamination is spread through feces and urine of the infected person.

Dangerous microorganisms

Vibrio choleraThis is the bacteria responsible for well-known disease Cholera. The disease is caused when humans take water infested with human feces. The incubation lasts about 1 to 7 days. The disease shows symptoms of chronic diarrhea, dehydration leading to much loss of water and salts. The loss should be made good

Dangerous microorganisms

TetanusThis is the very popular one. The good news is that there are vaccines available for it. For people who have not got the vaccine should get the vaccine in case if they get injured and there are chances that dirt-carrying spores might have entered their system. The disease shows treble symptoms such as lockjaw and terrible spasms.

Dangerous microorganisms

StaphylococcusStaphylococcus belongs to one of the largest bacterial group with over 40 subspecies and one of the most dangerous bacteria on earth. It can easily be found on anyone’s skin in a small amount.  A normal immune system of our body is capable of handling it efficiently on its own. However in the case where a normal immune system was not able to take care and the bacteria takes hold of someone, the antibiotics can be used

Dangerous microorganisms

SyphilisWe are mentioning Syphilis in this article since historically it was once the most debilitating diseases and was often called as the “great imitator”. The disease was very difficult to diagnose. In the disease, the genital sores would imitate other disease and would show symptom those of other diseases.

Dangerous microorganisms

Dengue fever virusAlso known as the break-bone fever, this virus is transferred to human when the infective female Aedes mosquito bites. This virus is circulating in the human body for around seven days during which the patient gets high fever, muscle and joint pain, nausea/diarrhea. In extreme cases, the diseases can turn into life-threatening where the patient suffers internal bleeding or extreme low blood pressure.

Dangerous microorganisms

Yellow feverYellow fever is an acute viral hemorrhagic disease that is transmitted by the bite of the female mosquitoes – Aedes aegypti that are mostly found in South America and Africa, but not Asia. In 1900s, it was considered as the most dangerous infectious fever. With yellow fever, the patient gets a fever, nausea, and muscle pain. These symptoms however subside in a few days

Dangerous microorganisms

HIVHuman Immunodeficiency Virus (HIV) is the most dangerous virus known. According to the reports,. It kills around 3 million people every year. Unfortunately, till now medical science has not been able to come up with any cure, so the only way is to take necessary prevention. HIV is the most dangerous virus in the world, and almost every mankind in the world are living in the threat of HIV.

Useful microorganism• There are some microorganism which are useful microorganisms.The following points highlight the top ten uses of microbes. The uses are: 1. Production of Antibiotics 2. Production of Dairy Products 3. Production of Alcoholic Beverages4. Production of Bread 5. Production of Food Yeast 6. Production of Organic Acids 7. Production of Vitamins 8. Production of Enzymes 9. Production of Steroids 10. Production of Dextran.

LactobacillusThere are more than 80 species of the Lactobacillus genus of probiotics. One of these species, acidophilus, is the most frequently used good bacterium, according to the University of Maryland Medical Center. Lactobacillus acidophilus, also called L. acidophilus, resides in the intestines where it helps in the digestion of food. As part of the digestion process, L. acidophilus produces lactic acid and hydrogen peroxide, which create unfavorable conditions for the growth of harmful bacteria. One way to get L. acidophilus in your diet is to eat yogurt that contains active cultures of this probiotic.

Bifidobacterium

If you carry the bacterium Helicobacter pylori in your stomach, you are at increased risk for stomach ulcers. Researchers have used a mouse model to show that a particular strain of the probiotic Bifidobacterium bifidum can help to repair stomach ulcers caused by Helicobacter pylori. The research results appeared in the February 2011 issue of "Applied and Environmental Microbiology." Another probiotic in this genus, Bifidobacterium breve, may be useful in the treatment of childhood constipation, according to a study in the February 2011 issue of "Nutrition Journal."

Streptococcus

• The probiotic Streptococcus thermophilus is a starter culture in the manufacturing process of yogurt, mozzarella cheese and other fermented dairy products, according to the European Bioinformatics Institute. One of the principal therapeutic uses for S. thermophilus is for relief of the abdominal cramps, diarrhea, nausea and other gastrointestinal symptoms associated with lactose intolerance.

Bacillus Coagulans

According to MedlinePlus, the Bacillus coagulans bacteria is a probiotic available as a dietary supplement that people use for various health concerns. Bacillus coagulans may be useful in the treatment of gastrointestinal disorders such as diarrhea associated with an antibiotic regimen, traveler's and children's diarrhea, inflammatory bowel disease and irritable bowel syndrome. The supplement may also be useful in preventing respiratory infections and enhancing their immune response. However, Natural Medicines Comprehensive Database has concluded that there is "Insufficient Evidence to Rate the Effectiveness" of Bacillus coagulans for any of the aforementioned therapeutic applications.