Mesophiles, or mesophilic bacteria, are the bacteria responsible for most human infections. This is the temperature of the human body. Examples include Listeria monocytogenes , Pesudomonas maltophilia , Thiobacillus novellus , Staphylococcus aureus , Streptococcus pyrogenes , Streptococcus pneumoniae , Escherichia coli , and Clostridium kluyveri. The human intestinal flora, or gut microbiome, contains beneficial mesophilic bacteria, such as dietary Lactobacillus acidophilus.
Extremophiles, or extremophilic bacteria, can withstand conditions considered too extreme for most life forms. Deep in the ocean, bacteria live in total darkness by thermal vents, where both temperature and pressure are high. They make their own food by oxidizing sulfur that comes from deep inside the earth. Some bacteria produce endospores, or internal spores, while others produce exospores, which are released outside. These are known as cysts. Clostridium is an example of an endospore-forming bacterium.
There are about species of Clostridium , including Clostridium botulinim C. Difficile , which causes colitis and other intestinal problems. Bacteria are often thought of as bad, but many are helpful. We would not exist without them. The oxygen we breathe was probably created by the activity of bacteria.
Many of the bacteria in the body play an important role in human survival. Bacteria in the digestive system break down nutrients, such as complex sugars, into forms the body can use. Non-hazardous bacteria also help prevent diseases by occupying places that the pathogenic, or disease-causing, bacteria want to attach to. Some bacteria protect us from disease by attacking the pathogens. Bacteria take in nitrogen and release it for plant use when they die.
Plants need nitrogen in the soil to live, but they cannot do this themselves. To ensure this, many plant seeds have a small container of bacteria that is used when the plant sprouts.
Lactic acid bacteria, such as Lactobacillus and Lactococcus together with yeast and molds, or fungi, are used to prepare foods such as as cheese, soy sauce, natto fermented soy beans , vinegar, yogurt, and pickles.
Not only is fermentation useful for preserving foods, but some of these foods may offer health benefits. For example, some fermented foods contain types of bacteria that are similar to those linked with gastrointestinal health.
Some fermentation processes lead to new compounds, such as lactic acid, which that appear to have an anti-inflammatory effect. More investigation is needed to confirm the health benefits of fermented foods. Bacteria can break down organic compounds. This is useful for activities such as waste processing and cleaning up oil spills and toxic waste. It also allows them to evolve resistance to artificial stresses like antibiotics.
A plasmid will not always replicate during the division process; occasionally they are passed to only one of the daughter cells. Plasmids replicate through a stretch of their own DNA that ensures replication by the parent bacterium cell, and can even replicate independently of the bacterium.
A single bacterium can contain hundreds of replicated plasmids. Bacteria are extremely diverse, and some forms of bacteria don't replicate through binary fission. The cyanobacteria Stanieria replicates within the cell wall, producing dozens or even hundreds of offspring called baeocytes.
The cell wall ruptures, and all the baeocytes are released simultaneously. In Epulopiscium, two small offspring cells form from the replicated DNA within a larger mother cell. When the offspring are fully developed, the mother cell dies, releasing two complete bacteria cells.
A reproductive process called budding has also been observed in some members of the Planctomycetes, but the mechanics of this process are still unknown. Select personalised content. Create a personalised content profile. Measure ad performance. Select basic ads.
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Binary Fission. Bacterial Recombination. Regina Bailey. Biology Expert. Regina Bailey is a board-certified registered nurse, science writer and educator. Updated October 12, Key Takeaways Binary fission is the process by which a single cell divides to form two cells that are genetically identical to one another.
This produces more offspring and more genetic variation in progeny. Many fungi can also reproduce sexually and asexually. Fungi often reproduce using spores — a type of seeds that can be spread by wind or rain.
If a spore lands in a good place, a new fungus grows. Some fungi use special structures to spread spores, like mushrooms. Fungi from the genus Pilobolus use a very special method to spread their spores. They mostly grow on poop, and they shoot their spores out at high speeds. Watch the film to see what that looks like. They need a host cell in order to be able to do it.
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