6 Microbial Growth

As a nurse in a plastic surgery clinic, you teach patients how to care for their sutures.

You tell patients to wash their hands, to wash around the surgical site with soap and water, and to use hydrogen peroxide to clean the wound.
One day a patient called, worried that the hydrogen peroxide caused her wound to bubble.

On page 155, you can read about catalase.

Although individual cells double in size during their lifetime, this change is not very significant compared with the size increases observed during the lifetime of plants and animals.

Manybacteria survive and grow in poor environments.

The one described in the Clinical Case is associated with biofilms.

Microbial populations can grow quickly.

We can determine how to control the growth of microbes that cause diseases by understanding the conditions necessary for their growth.
We can learn how to encourage the growth of helpful microbes.

In this chapter, we will look at the physical and chemical requirements for the growth of microbes, the various kinds of culture media, the phases of growth, and the methods of measuring growth.

The rod causes bright red colonies when thebacteria grow at room temperature.

The preferred Control and Prevention (CDC) in Atlanta, Georgia, has a temperature range.

The pH of culture media is controlled.

It seemed that large amounts of everything were needed for growth.

Micro bial growth can be divided into two main categories: survival and growth in a given environment.

It depends on its metabolism.

Sources of carbon, nitrogen, sulfur, phosphorus, oxygen, trace and their maximum and minimum growth temperatures are elements and organic growth factors.

They don't grow well at the high and low temperature extremes.

Somebacteria are capable of growing.

There are three primary groups for microorganisms.

optimum growth is represented by the peak of the curve.

Some species decline faster than others.

Some zones may produce toxins from rapid growth ofbacteria.

Some may grow.

The most common type of microbe is the mesyphilic one, which has an optimum growth temperature of 25-40degC.

Organisms that have adapted to live in the bodies of animals have an optimum temperature.

The band shows a deep temperature that grows well below freezing.

The pan of rice with a depth of 15 cm (6 in) is the most likely temperature range for about 5 hours.

They grow well at refrigerator temperatures with a shallow pan and a deep pot.

A cell is in a solution.

If the concentration of solutes such as NaCl cell is equivalent to a solute concentration in the surrounding medium, it is higher.

The cell is not growing.

The number of foods that can be used in a clinical culture is usually set at about 10.

Most of the common spoilage is preserved by acids produced by disease organisms.

The organisms capable of growth are tolerant of acidity.

Many of these organisms have optibacteria, which are found in the drainage water from coal mines and can survive at a pH 1.

It is possible for mold and yeasts to grow over a greater range of temperatures than can be found in the thermal waters of hot springs.

Under 45degC, alkalinity also acts.

It is rarely used to preserve food.

acids produced by elevated storage tempera interfere with their own growth.

These thermophilicbacteria are not included in the growth medium because they are not buffers.

A public health problem was considered by the peptones.
The advantage ofphosphate salts is that the temperature can rise quickly.

The Archaea has some microbes that havebacteria.

An optimum growth temperature of 80degC or higher is provided by them.

Most of these organisms live in hot springs that are associated with volcanic activity, and most of them get most of their nutrition from solu tant in their metabolism.

There is a record for the water.
Their composition is 80-90% water and they require water for growth and replication at high temperatures.
tion of solutes is higher in a solution with a concentra ocean that prevents water from boiling than in a cell with a concentra ocean.

Scientists believe only a few forms of life life forms.

The H2S and CO2 could be supplied by the hydrothermal vents in the thermalcyclers.

The next frontier in the hunt for new scientists is the vast expanse of barren basalt rocks.

They discovered that there were mats that could be used to fight cancer.

To make a method for making many copies of the same substance.

The only way to make photosynthesis in single-stranded DNA is by heating a chromosomes.

A chemical strand is being used.

The Deep VentR are not denatured at 98degC.

The growth of the cell is stopped.

Some species of halophiles can tolerate pulls away from the cell wall.

It's nearly all water with salted fish and honey.

The concentration of agar sweetened condensed milk is mostly preserved by this mecha, which is a complex polysaccharide isolated from marine algae.
Microbial cells that are present prevent growth.

The effects of osmotic pressure can affect the growth of somebacteria.

Some organisms have them for growth.

Carbon is essential for func microbial growth.

Cofactors are the structural backbone tions of certain enzymes.
The organic compounds that are added to a laboratory medium are made up of a living cell.
Carbon is the half the dry weight of a typical bacte that is assumed to be naturally present in tap water.
Most of the carbon components of media are obtained by Chemoheterotrophs.
Even most distilled waters contain ade from the source of their energy--organic materials such as pro quate amounts, but tap water is sometimes specified to ensure teins, carbohydrates, and lipids.
There are trace minerals in culture media.

We're used to thinking of O2 as a necessity of life, but it's actually a poisonous gas.

It is possible that life could not be sulfur-free due to the fact that there was very little oxygen in the atmosphere during sis.

Oxygen has caused the synthesis of DNA and RNA.
The forms of life require oxygen for the storage and transfer of chemical aerobic respiration, as well as for the synthesis of some elements.
There are hydrogen atoms in the cell.
The process yields 4%.

Microbes that use molecular oxygen extract more ment by decomposing material and rein energy from nutrients than microbes that don't use oxygen at all.

Nitrogen-based compounds are called organs that need oxygen to live.

Many aerobicbacteria have developed nitrates that can be used to grow in the absence of oxygen.

In some importantbacteria, facultative anaerobes can use oxygen when thesizing cyanobacteria is present, but can use gaseous nitrogen when it is not present, and can continue growth by using fermen directly from the atmosphere.

Some organisms that can use this method are free-liv, but their efficiency in producing energy decreases in the ing, mostly in the soil.

Nitrogen is used by the tinal tract.
Many yeasts are facultative.
The plant and the bacterium are both present.

It's most harmed by it in other places.

The species that cause tetanus and rus is thephosphate ion.
botulism is the most familiar example.
Oxygen atoms present in cellular materials are usually cofactors for enzymes, and calcium is used by thesebacteria as well.

It is also toxic.

Because has been boosted into a higher-energy state and is extremely hydrogen peroxide produced.

2H2O + O2 anaerobes form some superoxide radicals that are so toxic to cellular components that all organisms are affected.

Anyone who has put hydrogen in them.
Their toxicity is caused by their great instability, peroxide on a wound will recognize that cells in human which lead them to steal an electron from a neighboring tissue also contain catalase.

On page 194, there is a discussion of 2O2).

In the phagolyso environment, Oxygen is so abundant that it can be difficult for a microbe to avoid physical contact with it.

See how biofilms affect a patient's health.

The isolated single-spe is required for obligate anaerobes.

Many of the colonies are on laboratory plates.
The growth of the encasingbacteria that adhere to a surface is impeded by the accumulated lactic acid.
This fact was not well of aerobic competitors and establishes a favorable ecological appreciated until the development of confocal microscopy.
The three-dimensional structure of biofilms was made visible by common examples of lactic page 58.

The benefits of munities that provide benefits not unlike those of multicellular possess SOD make them able to tolerate oxygen.

There are forms of oxygen in the biofilms.

They are organized into a community.

Oxygen is required for bio aerobic.
Oxygen concentrations in the air are higher than those in films, which is why they grow only in films.
The community might be of a single species or a large amount of oxygen has been dispersed into the medium.
It is possible that biofilms grow near the oxygen-rich surface or below the narrow zone of more varied forms.
The biofilm might have enough oxygen in fast-flowing streams.
The form of streamers may be the reason for the limited tolerance.
Within a biofilm's sensitivity to superoxide radicals and peroxides, thebacteria are able to share resources and produce produce that is lethal in concentrations under oxygen-rich conditions.

Vitamins are one of the organic growth transfer factors for humans.

Most vitamins are coen by.

If the monobacteria grew in a uniformly thick state, they would become overcrowded, the vitamins would not be available in lower depths, and toxic waste would accumulate.

There are other organic growth factors that somebacteria avoid.

Migrating waste and resources.

This is a primitive adhering to the surface of the circulatory system.
Individual microbes and clumps of slimebacteria sometimes leave the established biofilm and move to a new location.
A biofilm is usually composed of a surface layer of 10mm thick with pillars that extend up to 200mm above it.

Complex tasks can be carried out by the microorganisms in biofilms.

The ruminant animals need a lot of different species to break down cellulose.

They can be a problem in pipes pillars of slime formed by the growth ofbacteria attached to solid surfaces.

This allows for efficient access to tubing, where it impedes circulation.

An important factor in human health is individual slime-formingbacteria in Biofilms.

The clumps of slime need to be moved to new locations.

The prevention of biofilms is important in health care.

There are two types of media: chemically defined and complex.

Justify the use of each of the following: dental caries, pseudomonad techniques, living host cells, candle jars, andbacteria.

There is a material prepared for the growth of microorganisms.

Somebacteria can grow well on any culture medium, others can't grow on non living nals, and still others can't grow on non living nals.
Another approach involves the medium.
There are many human secretions that can prevent biofilm formation.

First, it needs to enter the biofilms.

The majority of laboratory methods use organ to grow.

The isms should be cultured in their planktonic mode.
It is possible that there is no suitable level of oxygen and no adjusted pH.

The first thing it must do is focus on how the organisms actually live in relation to each other, so that the culture will one another and that this will be considered in industrial and contain only the microbes.

There is a wide variety of media available.

The growth ofbacteria is measured after water, test substance, and bacterium are combined.

The amount of vitamins in the test substance will be pro portional to the amount of vitamins produced by the bacterium.

The media that is used for iso lation and identification ofbacteria that are of interest to research ers in such fields as food, water, and clinical microbiology are constantly being developed or revised.

Agar remains solid because few microbes can degrade it.

3.0 g sea level remains liquid until the temperature drops to about K2hPo4*, 0.6 g 40degC.
Agar is held in water baths.

The container's atmosphere is 8.0 g.

Water 1 liter becomes a chamber.

Oxygen and hydrogen are combined in the medium in the plate to remove it from the water.

The chamber is usually used for experimental work or for the growth of autotrophicbacteria.

The screw is from batches to batches.

The envelope is mostly composed of protein.

Only a minority of organisms can use activated carbon directly, and that's because of the large, insoluble carbonate nature of the proteins.

Mostbacteria can digest H2 fragments.

Meat extracts or yeast extracts provide vitamins and other growth factors.

The vitamins and min Anaerobic indicator erals from the meats or yeasts are dissolved in the water which is then evaporated.
B vitamins are rich in yeast extracts.

There is a problem with the cultivation of anaerobicbacteria.

The media con dioxide is generated.

The hydrogen and atmospheric oxygen in the jar combine with dissolved oxygen and deplete the oxygen in the combine when reacting on the surface of a palladium catalyst.
The oxygen is removed.
Culture medium is in the jar.
Microbiologists use reducing media to oxidize and turn when the oxygen is removed to grow and maintain pure cultures.

What is the name of thebacteria that drive off oxygen?

Candle jars are used occasionally, but more often than not, chemical packets are used to generate carbon dioxide atmospheres in containers.

Aerosols containing pathogens will not escape if materials are introduced pressure.

Intake and exhaust air is taken care of through high-efficiency works through arm ports.

The exhaust from the particulate air filters is put into the cabinet when it is in use.
This unit has an internal camera air that is Filters twice.
The waste materials leaving the lab are monitored.

There are less dangerous organisms that are handled.

BSL-1 is the basic microbiology teaching labora tory.
BSL-3 labs are usually grown in armadillos, which have a relatively low infectious airborne pathogens such as the tuberculosis agent.

The nonpathogenic strains of this microbe should be negatively pressurized and equipped with air filters in the laboratory.

There is a discussion of cell culture.

CO2 can be higher or lower in this task.

The growth of the desired microbes is encouraged by cultures.

For example, if you put a lighted candle in a sealed jar, it will be used to isolated the typhoid from oxygen.

The late fungi can grow at this pH.

This can be the case for soil or fecal samples.

The medium for an enrichment culture is usually liquid and provides the environment that favors the growth of a particular microbe.

The medium is designed to increase very small numbers of the desired type of organisms to detectable levels.

Suppose we want to know if the soil sample has a microbe that can grow on phenol and is present in smaller quantities than other species.

In a BSL-4 facility, personnel wear a space suit for a few days, and then a small amount of it is transferred to an outside air supply.
Air pressure in the suit is higher than in the same medium.
After a series of atmospheres, the suit can't be entered by microbes.

How would a technician be able to metabolize phenol if they were working with prions?

The nutri ents in the original inoculum are quickly wiped out with successive transfers.

When the last dilution is streaked onto the reactions with differential media.

A remarkable microbiologists use this technique to identify the types ofbacteria that destroy red blood cells.

Sometimes, differential andselective characteristics can be combined in a single medium.

The organisms can ferment the carbohy drate mannitol to form acid and have a tolerance for high concentrations of sodium chloride.

The red blood cells have been lysed by the bacteria.

The patients did not develop infections during the previous outbreak, so Dr. MacGruder must look for a new source of infections.

The media is designed to water or food.

colonies of exact copies of the original organisms will form if the materials are plated out onto the surface.

Pure cultures, or clones ofbacteria, are required for most bacteriological work.

The direction of streaking is indicated by the arrows.

The loop lated colonies.

The colonies can be picked up with an inocu.
In the second and third series, the loop picks the lating loop and transfers it to a test tube to culture a single type of bacterium.

There are many variations of this pattern.

When the organ types are red and yellow, the streak plate method works well.

Humans on the Space Station would die instantly from cold and the vacuum of space if it were to suddenly burst.

Direct and indirect methods of measuring cell temperature can be used.

It's important to be able to determine tures from 250 to 295degC.

The culture can usu numbers directly by counting or indirectly by ally, which can be thawed and cultured several years later.
They measured their metabolism activity.

While under vacuum, the container is sealed by melting the rial growth, not a glass with a high-temperature torch.

The size of the individual cells increases.

The organisms can be revived by hydration with a liquid medium.

The cells are replicated.

When the number of cells in each genera tion is expressed as a power of 2, the exponent tells the number of doublings that have occurred.

It varies depending on the environment and the organisms.

A generation time of 1 to 3 hours is the average for mostbacteria.

An enormous number of cells will be produced.

25 is the number of generations indicated by the superscript.

To arrive at the numbers in the center column, certain actinomycetes reproduce by using the yx key on your calculator.

The number 32 will be shown on the calculator.
A few colonies ofbacteria will have 32 cells.
The log key on your calculator can be used to arrive at the numbers in the right-hand column.
Simply fragment, and the fragments initiate the growth of the number 32, then press the log key.
The rounded cells will be shown by the calculator.

It's hard to graph population changes using numbers.

The graph logarithmic plot point for the tenth generation (3.01) has been drawn so that the curves intersect up the graph.

The figure shows how graphs of changes in the number ofbacteria would increase the plots rather than decreasing them.
Take the line off the page if it's at ten height of the graph.

If the numbers were plotted for two more generations.

We are not used to it and the cells are not active.

It is necessary for a period of intense metabolic activity involving, in proper understanding of graphs of microbial populations, that the population is thinking in logarithmic relationships.

The lag, log, which the population doubles, is one of the four basic phases of growth.

For a while, the number of cells changes very little because of the ferred for industrial purposes where, for example, a product cells do not immediately reproduce in a new medium.

Knowledge of the growth curve is important to understand population dynamics and population control in the course of infectious diseases, as well as in food preservation and spoilage.

Microbial death will be discussed in Chapter 7 if exponential growth continues.

The population curve would be the same as that of an 80,000-ton aircraft carrier if two mice started a family with a fixed food supply.

It's not always clear what causes exponential growth to stop.

The amount of waste products is proportional to cell numbers.

Population numbers are related to changes in the pH.

In the pop example, a millionth of a liter of sour milk is diminished to a tiny fraction of the number of cells.

There must be 70 times in the previous phase until the population dies out.

In serial dilutions, the original inoculum is changed in a series of tubes.

Each dilution tube will only have a fraction of the number of cells as the preceding one.
colonies can be counted using samples of the dilution used to inoculate the Petri plates.
The count is used to estimate the number ofbacteria in the sample.

It's not practical to measure out a millionth of a millionth of a gram of food in some applications.

It's not possible to hold a particular lot for this length of time.

If we add 1 liter of water and 1 liter of milk to the same amount of water, we can grow a single colony.

This is not always true, this dilution now has one-hundredth as manybacteria as each, becausebacteria frequently grow linked in chains or as clumps of the original sample had.
We can estimate the number ofbacteria from short segments of a chain or original sample if a colony results.
To count the populations of bugs in food.

When a plate count is performed, it is important that only a small number of colonies can be transferred with a pipette.

Plates with 30 to 300 colonies are preferred by this ologists.

To make sure that method is used, it is necessary to measure the number of viable cells.

Add melted food.

To mix, swirl to mix.

The plate count is done by either 10,000 or morebacteria.

The pour plate method or the spread plate method could be used to plate this sample.

A countable plate is either 1 or 0.1 liter of the suspension.

If a sample was transferred to a dish.
The tube of sterile water in which each liter of fluid agar is kept is now filled with 1000bacteria.
If a small amount of this was poured over the sample, then mixed into the medium sample, then it would still be able to be inoculated into a plate.
There are too many colonies to count on a plate.
An plate is put into a container.
colonies could be made with the pour plate technique.
A second tube of trient medium would be used to transfer the grow within the agar to the surface of water.
The agar plate would only be 100 in this tube.

The technique has some drawbacks because some relatively out colonies may be damaged by the melted countable number.

A sample can be passed through a membrane on agar to determine the surface of the filter.

This medium is used for filters.
Here, the coliforms have been sieved out onto the surface of the filter, forming a distinctive colo- surface.
When placed on the surface of a suitable medium, we can see that there are over 200 colonies visible.

Colonies beneath the surface of a pour plate are not a series.

When the tests are satisfactory, the MPN method is most useful.
When inoculum is added to the surface of a prepoured, solidified agar the growth ofbacteria in a liquid differential medium is used.
The inoculum is spread uniformly over the sur to identify the microbes.
The metal rod is called the MPN.
The method positions the colonies on the surface so that there is a good chance that the popula will avoid contact with the agar.

In this technique, at least 100 liters of a bacterial suspension is placed within a defined water and then passed through a thin filter with a microscope slide.

Because of time considerations, this is too small.
The method is used to count the number ofbacteria in milk.

A sample is spread over a square centimeter and transferred to a petri dish with a stain added to make it easier to see the colonies on the filter's surface.

This method can be used to determine the area of the viewing field that can be detected.

The colonies formed fields, the average number ofbacteria per viewing field, are distinctive.

The number ofbacteria in the medium is used.

It's not always necessary to count the cells.

The absorbance is used to plot.

The numbers that are statistically likely to lead to such a result are calculated using the MPN tables.

In the shaded example, 5, 3, and 1 are the number of positive tubes recorded.
The majority of the water samples that give this result contain between 34 and 250 organisms.

Dr. MacGruder wants to know how manybacteria are colonizing a patient's catheter.

The amount is likely to be counted as live ones.
He concludes that a high concentration of cells is required to be the bacteria grow slowly.
The time of 35 hours may have been original and introduced into advantage of the tiny counts.

The instruments are used in laboratories and hospitals.

The number ofbacteria is given in a slide.

This type of counting is often used to estimate the population ofbacteria in dairy products.

The shallow volume over the squares is filled by capillary action.

The numbers are averaged.

The slide has 14 cells.

If 14 of the squares are known, then the volume of the cells can be calculated using the depth of the area.

The more light is transmitted, the morebacteria are in the sample.

The sample could be reported as either 20% transmittance or 0.7 absorbance.
Readings in absorbance are useful in plot data.

The first traces of turbidity will be visible.

You now have a basic understanding of the requirements, and 100 million cells per liter are needed to make a suspension measurement.
We will look at turbid in Chapter 7.
Turbidity is not a good measure of the amount of growth in laboratories, hospitals, industry and our homes.

CO through 20 generations in a month.

The number ofbacteria present is in direct proportion to 2.

A plate count wouldn't measure the bloodstreams of these patients at the same time as the first increase in mass.

Asexual spores are counted instead of the asexual ones.
This isn't a good mea in the catheters.
In this procedure, catheters become colonized by organisms that have been removed from the growth medium, and that heparin has been reported to cause biofilm formation.
Dr. MacGruder dried extraneous material in a desiccator.
It is concluded that thebacteria in the biofilm were weighed.
The same procedure is followed forbacteria.

Incubation time for a colony is usually required by direct methods.

The best pH for mostbacteria is between 6.5 and 7.5.

An increase in the number of people is called population growth.

All organisms need a carbon source; autotrophs use carbon dioxide.

Both physical and chemical requirements are needed for growth of microbes.

Nitrogen is needed for synthesis.

The classification of organisms on the basis of oxygen requirements is as follows: psychrophiles (cold-loving), mesophiles (moderate as obligate aerobes, facultative anaerobes, obligate anaerobes, temperature-loving), and thermophiles (

2 H2O + O2 or lyophilization.

See how biofilms affect a patient's health.

The majority ofbacteria live in biofilms.

The generation time is the rate at which antibiotics are resistant to Microbes are more resistant to antibiotics than are known.

The division ofbacteria occurs in a laboratory.

It is known as a culture.

Agar is used in a culture medium.

The log phase is when thebacteria multiply at the fastest rate possible.

The exact chemical composition of a chemical y defined medium is known.

There is an equilibrium between cell division and death during the stationary phase.

The exact chemical composition of a complex medium is formed.

Reducing media chemical removes O2 and assumes that each bacterium grows into a single colony.

A plate count can be done by either the pour plate method or the chamber.

There are some parasites and fastidiousbacteria that need to be cultured in living.

It is a statistical requirement for an increased CO2 concentration to be used to growbacteria that will grow in a liquid medium.

biosafety levels 1 through 4 are the levels of the measured volume microorganisms.

The slide was designed.

Turbidity is determined by measuring microbes.

Different organisms are distinguished by differential media.

In a mixed culture, an enrichment culture is used to encourage the growth of a particular microorganism.

Dry weight is a convenient method of growth measurement for filamentous organisms.

A colony is a mass of organisms.

The streak plate method can be used to obtain pure cultures.

There is an answers tab at the back of the textbook.

Questions 1 and 2 can be answered using the following information.

Four differentbacteria were inoculated with culture media.

The following graph can be used to answer questions.

Natural oil-degradingbacteria grow after an oil spill.

Define complex and chemical media.

The cells are kept at 35 degrees for 5 hours.

After 5 hours, the temperature goes to 20degC.

35degC for 5 hours followed by 2 hours.

The characteristics of the microbe are described.

An organisms that has peroxidase and superoxide dismutase but does not have catalase is most likely for growth ofbacteria.

You can draw the growth curves for the organisms.

The yeast is in the broth at 30degC with aeration.

There are 106 glucose-minimal salts in a jar.

The yeasts are related to anaerobes.