Beneficial and Harmful Bacteria PDF

**[Beneficial and Harmful Bacteria]** Bacteria are single cells and are classified as prokaryotic -- this means they have no well-defined nucleus and no membrane-bound organelles Their DNA structure is looped rather than linear like in humans. Bacteria range from the essential and useful, to the ha...

**[Beneficial and Harmful Bacteria]** Bacteria are single cells and are classified as prokaryotic -- this means they have no well-defined nucleus and no membrane-bound organelles Their DNA structure is looped rather than linear like in humans. Bacteria range from the essential and useful, to the harmful. **[Essential bacteria]** Without the key functions of some bacteria, life on earth would be very different: - Some bacteria degrade organic compounds for energy, and without bacteria, the earth would have no soil in which to grow plants. - Bacteria living in the gut can help animals break down food. These so-called 'good bacteria' (or gut flora) help maintain the conditions necessary for food digestion. - Some bacteria live on the root nodules of certain plants, for example, peas, beans and clover, and are able to 'fix' atmospheric nitrogen into a form that can be absorbed by the plant as a fertiliser. [Useful bacteria] ----------------------------- Bacteria have long been used by humans to create food products such as **cheese, yoghurt, kimchi, soy sauce, miso, bean pastes and vinegar**. We are also able to use bacteria to **break down our sewage and to clean up oil spills**. [Harmful bacteria] ------------------------------ Only a small handful of known bacteria are **capable of causing disease**. These bacteria are termed** pathogenic** or we say they are **pathogens**. An example is *Staphylococcus aureus* or more commonly "golden staph". These bacteria are on our skin at all times but are opportunistic and can cause infection (and possibly death) if they get into the blood stream. To cause disease, the bacteria must invade the cells of a living organism. Most bacteria will not invade another living organism, and many more bacteria are rendered harmless by our immune systems, while others, such as gut bacteria, are beneficial. In many developing countries, poor hygiene, limited access to clean water and poor (or no) sewage treatment leads to huge numbers of deaths from bacterial infections such as those that cause dysentery. The advent of **antibiotics** (basically meaning "against life") like **penicillin** has greatly reduced the number of deaths due to bacterial infections. However, increased use of antibiotics in many western countries has led to the adaptation of antibiotic-resistant bacteria, which can lead to outbreaks of so-called 'super bugs', such as Multi-Resistant *Staphylococcus aureus* (MRSA). Scientists now believe that humans require contact with bacteria at an early age in order to 'educate' our immune systems between good and bad bacteria. The scientists believe that western societies' obsession with antibacterial products has increased our chances of developing immune-related conditions such as asthma, allergies and eczema. **[Beneficial and Harmful Bacteria]** Bacteria are single cells and are classified as prokaryotic -- this means they have no well-defined nucleus and no membrane-bound organelles Their DNA structure is looped rather than linear like in humans. Bacteria range from the essential and useful, to the harmful. **[Essential bacteria]** Without the key functions of some bacteria, life on earth would be very different: - Some bacteria degrade organic compounds for energy, and without bacteria, the earth would have no soil in which to grow plants. - Bacteria living in the gut can help animals break down food. These so-called 'good bacteria' (or gut flora) help maintain the conditions necessary for food digestion. - Some bacteria live on the root nodules of certain plants, for example, peas, beans and clover, and are able to 'fix' atmospheric nitrogen into a form that can be absorbed by the plant as a fertiliser. [Useful bacteria] ----------------------------- Bacteria have long been used by humans to create food products such as **cheese, yoghurt, kimchi, soy sauce, miso, bean pastes and vinegar**. We are also able to use bacteria to **break down our sewage and to clean up oil spills**. [Harmful bacteria] ------------------------------ Only a small handful of known bacteria are **capable of causing disease**. These bacteria are termed** pathogenic** or we say they are **pathogens**. An example is *Staphylococcus aureus* or more commonly "golden staph". These bacteria are on our skin at all times but are opportunistic and can cause infection (and possibly death) if they get into the blood stream. To cause disease, the bacteria must invade the cells of a living organism. Most bacteria will not invade another living organism, and many more bacteria are rendered harmless by our immune systems, while others, such as gut bacteria, are beneficial. In many developing countries, poor hygiene, limited access to clean water and poor (or no) sewage treatment leads to huge numbers of deaths from bacterial infections such as those that cause dysentery. The advent of **antibiotics** (basically meaning "against life") like **penicillin** has greatly reduced the number of deaths due to bacterial infections. However, increased use of antibiotics in many western countries has led to the adaptation of antibiotic-resistant bacteria, which can lead to outbreaks of so-called 'super bugs', such as Multi-Resistant *Staphylococcus aureus* (MRSA). Scientists now believe that humans require contact with bacteria at an early age in order to 'educate' our immune systems between good and bad bacteria. The scientists believe that western societies' obsession with antibacterial products has increased our chances of developing immune-related conditions such as asthma, allergies and eczema.