Spore forming bacteria
Introduction
The spore formation is kind of asexual reproduction which happens when the environmental conditions around the Bactria become not suitable for it and for protection too.
Spores all the time haploid and unicellular and are generated by meiosis in the sporangium of a diploid sporophyte. Under convenient conditions the spore can use mitotic division to promote into a new organism, which produce a multicellular gametophyte, which eventually goes on to produce gametes. Zygote been formed from Two gametes, which develops into a new sporophyte. This cycle is known as alternation of generations.
Type of bacterial spores
Endospores
Endospores, are powerful against harsh chemical and physical conditions. This gives the ability to the bacteria to resist disinfectants, radiation, desiccation and heat. Bacillus are a big reason for food and medical contamination and are often difficult to get rid of them. endosporulation process start When a bacterium detects unfavorable environmental conditions, which takes eight hours long. The DNA is replicated and a membrane wall known as a spore septum begins to form between it and the rest of the cell. The plasma membrane of the cell surrounds this wall and pinches off to leave a double membrane around the DNA, and the developing structure is now known as a forespore. Calcium dipicolinate, is a molecule of calcium and dipicolinic acid, that is incorporated into the forespore during this time. The dipicolinic acid helps stabilize the proteins and DNA in the endospore. Next the peptidoglycan cortex forms between the two layers and the bacterium adds a spore coat to the outside of the forespore. In the final stages of endospore formation the newly f...
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... B. cereus and other aerobic endospore formers are introduced via vegetables, fruits, or herbs and spices, while anaerobic spore formers like nonproteolytic Clostridium botulinum and Clostridium estertheticum pose safety and spoilage risks in chilled packaged foods, respectively.
References
microbeonline. Available at: http://microbeonline.com/bacterial-spores-structure-importance-and-examples-of-spore-forming-bacteria/ (Accessed: 24 April 2014).
Microbiology Books and Molecular Biology Books. Available at: http://www.horizonpress.com/spores (Accessed: 24 April 2014).
Cornell University Department of Microbiology. Available at: https://micro.cornell.edu/research/epulopiscium/bacterial-endospores (Accessed: 24 April 2014).
microbeworld. Available at: http://archives.microbeworld.org/know/spore.aspx (Accessed: 24 April 2014).
After 48 hours of incubation the agar plates were viewed. Individual colonies were tested for successful isolation by gram staining and then viewing the stained bacteria under a microscope. Isolation was successful. One colony of each unknown bacteria was transferred to an agar slant for growth. The agar slants were stored at room temperature over the weekend so that they would not grow too much.
The next step includes the two nuclei of the dikaryon fusing through karyogomy (Ross 146). The resulting diploid zygotic nucleus then undergoes meiosis, and four haploid nuclei are formed in the basidium (Webster 280). The haploid nuclei move into projections on the basidium, which turn into spores. The spores are attached to the sterigmata until they are released (Ross 146). The cycle then starts over again.
A streak for isolation is made on the plate. In addition, check plate for hemolysis. Look for the organism’s ability to produce hemolysin. Bacteria with hemolysin will generate different patterns. To start with, partially green around the colony is alpha. Secondly, complete clearing around the colony is betta. Thirdly, cloudiness or no result is gamma. The controls are K. pneumoniae, B. cereus, and S. saprophyticus in order based on previous results.
The gametophytes used in this experiment are of C-ferns. They tend to mature and produce spores at temperature of 28oC and conditions of high humidity. The spores that germinate first are hermaphrodites. Hermaphrodites tend to produce a pheromone called antheridiogen. It is this pheromone that causes later germinating spores to become male.
Bacillus anthracis is a non-motile elongated rod-shaped bacterium that will generate dormant spores with or without oxygen. When the spores are exposed to high levels of carbon dioxide and warmth they adjust into a ro...
In telophase, these separate chromatids uncoil to become chromosomes. This division produces two identical cells.
Clostridium perfringens is a gram-positive spore-forming bacillus involved in foodborne illness and wound infection. It is an obligate anaerobe and the only member of the genus Clostridium that is non-motile. This microorganism is normally present in soil and decaying vegetation and is an inhabitant of animal and human intestines. According to the Centers for Disease Control and Prevention, C. perfringens is one of the most common sources of foodborne illness in the United States, being the cause of an estimated 1 million cases each year. However, it is also prevalent worldwide. This bacterium has the shortest reported generation time of any organism at 6.3 minutes in thioglycollate medium, making it particularly virulent after initial inoculation.
Sexual reproduction is that the union of male and feminine gametes to create a fertilised egg or zygote. The ensuing offspring inherit one-half their traits from every parent. Consequently, they 're not genetically similar to either parent or siblings, except within the case of identical twins. As theorised by Mendel, adults are diploid, meaning as 2N, having 2 alleles offered to code for one attribute. The gametes should be haploid, signified by N, containing just one allele in order that once 2 haploid gametes mix, they manufacture a traditional diploid individual. The method where haploid sex cells are created from diploid parents is known as meiosis, and it happens solely within the reproductive organs.
This gave rise to nonvascular plants like, mosses, liverworts, and hornworts. The second period of plant evolution began 425 million years ago was the diversification of plants with vascular tissue allowing plants to grow much taller and rise above the ground. The next period of plant evolution is the origin of seeds, about 360 million years ago. Seeds are embryos packed along with food in a protective covering. Last is flowering plants about 140 million years ago, which is seeds within protective chambers called ovaries. Animal evolution begins when an animals egg and sperm fuse, producing a zygote. The zygote splits by mitosis and forms an blastula, which usually is a hollow ball of cells. One side of the blastula folds in forming a gastrula, which develops into an embryo with a two-layered wall and an opening on one end. After the gastrula stage animals develop into
Sordaria fimicola is a species of microscopic fungus that is an Ascomycete and are used to test for genetic variation in the lab setting (Sordaria fimicola: A Fungus used in Genetics, Volk). These organisms are what are called model organisms, or species that has been widely studied usually because it is easy to maintain and breed in a laboratory setting and has particular experimental advantages (Sordaria fimicola, Volk). S. fimicola, because it is in the Ascomycota phylum, have a distinguishing reproductive structure called the ascus, which is surrounded by the perithecium. This cylindrical sac-like structure houses 8 haploid spores; created through meiosis to produce 4 haploid spores and then mitosis to make 8 (Lab Manual, pg. 59-68). Based on the genotype they will vary in order and color. There are 3 different ratios that can arise from the 8 ascospores: 4:4, 2:2:2:2, and 2:4:2 (black/wild type and tan coloration). The 4:4 ratio suggests that no crossing over had occurred because there is no difference in order of the color parents that were mated. The two other ratios suggest genetic recombination, or crossing over, because of the
Meiosis, also called reduction division, is a distinct type of cell division that is essential for sexual reproduction to occur. It is one in which two successive divisions of diploid cell occur thereby producing four genetically different haploid daughter cells, also called gametes, each with half the number of chromosomes and thus, half the total amount of genetic material as compared to the amount before meiosis began. Interphase precedes meiosis and thus, paves the way for meiosis to eventuate as the cell’s DNA replicates in the S phase yielding corresponding, identical chromosomes. Interphase sparks the marvelous process of meiosis that allows variation to transpire within the organisms it occurs, hence, giving rise to millions of organisms with unique aspects unlike any other on Earth. Because meiosis is a form of sexual reproduction itself, it is the means through which gametes are produced, each with a reduced number of chromosomes, so that when two gametes fuse during fertilization, not only do they form a diploid zygote with 46 chromosomes, but also have manifested differing features due to the rearrangement (crossing-over) of chromosomes.
Bacterial cells, like plant cells, are surrounded by a cell wall. However, bacterial cell walls are made up of polysaccharide chains linked to amino acids, while plant cell walls are made up of cellulose, which contains no amino acids. Many bacteria secrete a slimy capsule around the outside of the cell wall. The capsule provides additional protection for the cell. Many of the bacteria that cause diseases in animals are surrounded by a capsule. The capsule prevents the white blood cells and antibodies from destroying the invading bacterium. Inside the capsule and the cell wall is the cell membrane. In aerobic bacteria, the reactions of cellular respiration take place on fingerlike infoldings of the cell membrane. Ribosomes are scattered throughout the cytoplasm, and the DNA is generally found in the center of the cell. Many bacilli and spirilla have flagella, which are used for locomotion in water. A few types of bacteria that lack flagella move by gliding on a surface. However, the mechanism of this gliding motion is unknown. Most bacteria are aerobic, they require free oxygen to carry on cellular respiration. Some bacteria, called facultatibe anaerobes can live in either the presence or absence of free oxygen. They obtain energy either by aerobic respiration when oxygen is present or by fermentation when oxygen is absent. Still other bacteria cannot live in the presence of oxygen. These are called obligate anaerobes. Such bacteria obtain energy only fermentation. Through fermentation, different groups of bacteria produce a wide variety of organic compounds. Besides ethyl alcohol and lactic acid, bacterial fermentation can produce acetic acid, acetone, butyl alcohol, glycol, butyric acid, propionic acid, and methane, the main component of natural gas. Most bacteria are heterotrophic bacteria are either saprophytes or parasites. Saprophytes feed on the remains of dead plants and animals, and ordinarily do not cause disease. They release digestive enzymes onto the organic matter. The enzymes breakdown the large food molecules into smaller molecules, which are absorbed by the bacterial cells. Parasites live on or in living organisms, and may cause disease. A few types of bacteria are Autotrophic, they can synthesize the organic nutrients they require from inorganic substances. Autotrophic bacteria are either photosynthetic or Chemosynthetic. The photosynthetic bacteria contain chlorophyll that are different from the plant chlorophyll. In bacterial photosynthesis, hydrogen is obtained by the splitting of compounds other than water.
In this method, living spores which are resistant to whichever sterilizing agent is being tested are prepared in either a self contained system, such as dry sp...
In Meiosis 1, chromosomes in a diploid cell resegregate, producing four haploid daughter cells. It is this step in Meiosis that generates genetic diversity.Meiosis 2 is similar to mitosis. However, there is no "S" phase. The chromatids of each chromosome are no longer identical because of recombination. Meiosis II separates the chromatids producing two daughter cells each with 23 chromosomes (haploid), and each chromosome has only one chromatid.
These are the places where biofilms are formed. Biofilms are formed by a six-step process. First is a reversible process, when an organic monolayer (made of polysaccharides or glycoproteins) absorbs to the surface, altering the chemical and physical properties of the surface. This makes the surface more conditioned and increases the chance that planktonic bacteria will attach. Secondly, also a reversible step, is when the free-floating or planktonic bacteria encounter the conditioned surface, and some attachment of the bacteria may occur.