Microbial growth factors. 17.2: Factors that Influence Bacterial Growth 2019-02-02

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Factors Affecting Microbial Growth

microbial growth factors

Their growth minima is 45°C. Low levels of these radiations may cause mutations and may indirectly result in death whereas high levels may directly cause death of the microbes. The aero-tolerant bacteria like Lactic acid bacteria possess enzyme peroxidases instead of catalase to decompose the accumulated hydrogen peroxide. Thus, water always diffuses from a region of its higher concentration to a region of the lower concentration. A solution consists of a solute dissolved in a solvent. Antifreeze proteins and solutes that decrease the freezing temperature of the cytoplasm are common. With professional equipment and highly-trained staff capable of testing for any number of bacteria, fungi, molds and other potential microbes that could affect the health of a building, Airtek Environmental can detect any potential health threat present.

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Physical Factors that Control Microbial Growth

microbial growth factors

Decrease in nutrient concentration decreases the growth rate. Can you make an educated guess as to its optimum temperature of growth? Buffers are salts of weak acids or bases that keep the pH of the medium constant. The latter is very reactive and powerful oxidizing agent and quickly destroys a cell. Hyper­thermophiles usually do not grow well below 55°C e. The micro-organisms that are completely dependent on atmospheric oxygen for growth are called obligate aerobes whereas those that do not require oxygen for growth but grow well in its presence are called as facultative anaerobes. For example, enzyme activity depends on the temperature of the environment, and microorganisms are classified in three groups according to their temperature preferences: psychrophilic organisms psychrophiles prefer cold temperatures of about 0°C to 20°C; mesophilic organisms mesophiles prefer temperatures at 20°C to 40°C; thermophilic organisms thermophiles prefer temperatures higher than 40°C Figure.

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Factors That Affect the Growth of Microorganisms

microbial growth factors

Elements Present In addition to water, microorganisms usually require the presence of certain elements in the air--gases that they absorb to produce needed nutrients. An autotroph can synthesize organic molecules from inorganic nutrients. Photoautotrophs use light as an energy source and carbon dioxide as their main carbon source. Thus, understanding of environmental influences on the growth of microorganisms becomes mandatory. This effect is negligible in viruses since they are not metabolically active. Microbes can be roughly classified according to the range of temperature at which they can grow.

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Microbial Growth Factors

microbial growth factors

This experiment was performed at room-temperature. However, some types of molds and yeasts can withstand very low pH. Thus, drying of food or addition of his concentration of salts and sugars is the most popular way of preventing spoilage of food. Microbes will therefore better when they are in their optimum environment. Thus, pH can dramatically affect the growth of microorganisms. However, A barophile has been recovered from the depth about 10,500 m in sea near Philippines and has been found unable to grow at 2°C temperature and below about 400-500 atmospheric pressure Radiation Some electromagnetic radiations, particularly the ionizing radiation e.

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Temperature and Microbial Growth

microbial growth factors

It is a frequent cause of pneumonia in people who have beencompromised by other illness. Therefore, the higher the solute concentration, the lower the concentration of free water molecules capable of passing through the membrane. In fact, the microorganisms are very sensitive to the temperature since their temperature varies with that of environment puikilothermic. Clostridium tetani - agent oftetanus, puncture wounds, produces a toxin which enters the spinalcolumn and blocks the inhibitory spinal motor neurons. Relevant discussion may be found on the. Bacterial enzymes can be inactivated when interact with oxygen.


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Factors Affecting Microbial Growth

microbial growth factors

These wastes often become inhibitory agents as they alter the pH of surrounding environment. The latter are damaged by the normal atmospheric level of oxygen 20%. The above graph is expressing the changes in the growth rate of microorganisms. However, careless use and overuse of artificial fertilizers have been demonstrated to have significant negative impacts on aquatic ecosystems, both freshwater and marine. The lowest temperature at which the organism can survive and replicate is its minimum growth temperature.


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Microbiology Ch 6

microbial growth factors

Bathrooms and basements tend to be prone to dampness and stagnant water, making them a key location for potential microbe issues. Radiation: Some electromagnetic radiations, particularly the ionizing radiation e. The enzyme catalase decomposes hydrogen peroxide into oxygen and water. At low temperature enzymes are not denatured, therefore, every 10°C rise in temperature results in rise of metabolic activity and growth of microorganisms. In order to grow successfully, microorganisms must have a supply of water as well as numerous other substances including mineral elements, growth factors, and gas, such as oxygen.

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Factors Affecting Microbial Growth

microbial growth factors

Low levels of these radiations may cause mutations and may indirectly result in death whereas high levels may directly cause death of the microbes. The food sources can vary, but the organisms primarily extract carbon and nitrogen from substances such as proteins, fats and carbohydrates. A case study of an irradiated Escherichia coli population found a growing number of bacteriophage-resistant mutants induced by the light. Things to Check to Identify Microbial Growth Water and Dampness Warmth, moisture, pH levels and oxygen levels are the four big physical and chemical factors affecting microbial growth. Factors Affecting Microbial Growth The key to a productive staff is creating and maintaining a safe and healthy work environment. Specific growth factors may also be required such as blood or specific type of protein. In most buildings, warmth and moisture are the biggest overall issues present.


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Microbiology Ch 6

microbial growth factors

Nataliya was admitted to the hospital for treatment and recovery. Halobacterium, a halophilic archaebacterium, inhabits Dead Sea a salt lake situated between Israel and Jordan and the lowest lake in the world , the Great Salt Lake in Utah and other aquatic habitats possessing salt concentrations approaching salt water. To their surprise, the samples retrieved from the lake showed abundant microbial life. The experimenters then added a dye to the solution and also monitored formate metabolism using in-situ Raman spectroscopy. Increased fluidity impairs metabolic processes in membranes. The values for cardinal temperature vary widely among bacteria.

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Factors That Affect the Growth of Microorganisms

microbial growth factors

Mucor pusillus are also thermophiles. The excited photosensitizer P transfers its energy to oxygen which then results in singlet oxygen 1O 2 , The latter is very reactive and powerful oxidizing agent and quickly destroys a cell. Fungi and bacteria cultivating in a building can enter the ventilation systems and cause widespread illness and discomfort among workers. The spoilage of refrigerated food takes place because of facultative psychrophiles. For convenience, bacteria isolated from hot springs can survive even at temperature of 100°C and above, while those isolated from snow can survive below -10°C. They obtain their energy through aerobic respiration.

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