Micro Lab 7 Bacteriophage, Fermentation, Environmentall Effects I and Antimicrobials

obligate intracellular parasites; capsid

Like all viruses, bacteriophages, are _____________, that is, they must invade a host cell in order to replicate and reproduce. -This is due to the fact that viruses lack the metabolic machinery, such as energy systems, and protein synthesis components necessary for independent replication and are composed primarily of only one kind of nucleic acid molecule (RNA or DNA) encased in a protein coat, or ________, that protects the nucleic acid.

psychrotrophs.

Listeria monocytogenes and Campylobacter, foodborne pathogens, can also grow at 4°C. These bacteria are_______

0-100

Microorganisms can grow over a broad temperature range extending from __°C to ___°C

C. peroxidase or catalase

Most aerobic bacteria produce _______ to convert toxic forms of oxygen (peroxides) to oxygen and water. A. oxidase or peroxidase B. superoxide dismutase or oxidase C. peroxidase or catalase D. catalase or oxidase

mesophiles

Most bacteria are ______

anaerobes

Most obligate _____ do not possess catalase or superoxide dismutase

thioglycollate

FTM is composed of glucose, cystine, and sodium ______ to reduce its oxidation/reduction potential.

true

Fermentation is a means of food preservation. True or False

acids and alcohols

Fermentation is actually a means of food preservation because the ___ and ____ produced and the anaerobic environment hold back the growth of many spoilage microbes.

narrow

Sulfa drugs are more ________ in spectrum because not all bacterial cells can synthesize the vitamin folic acid, whose synthesis is inhibited by this drug.

False

Synthetic antibiotics are produced by microorganisms and chemically altered to make them more effective in their mode of action. True or False

specificity

Viruses also exhibit ________ for their hosts. For example, a certain bacteriophage may only infect a specific strain of a species of bacteria.

Pseudomonas

For example, some mesophiles such as Proteus, _________, and Leuconostoc can grow at 4°C, refrigerator temperatures, and cause food spoilage.

Aerotolerant

Grow well under aerobic conditions, but does NOT use oxygen; use only fermentation to produce energy

bacteriostatic

If a particular agent only inhibits the growth of bacterial cells but does not kill them, we say that the agent is _______. Were the agent to be removed, growth of the bacterial cells would resume.

plaques

If bacteriophage are applied to a confluent lawn of bacterial cells on an agar plate, phages will infect the bacterial cells causing them to undergo the lytic cycle above and clear areas called ____ will form within the bacterial growth.

plaques

If bacteriophage can infect a bacterial culture, clear areas called ______ will form within the bacterial growth. A. no answer is correct B. plaques C. zones of inhibition D. lytic spaces

200; burst size

lytic phage infection of a bacterial cell: One phage particle infecting a single cell can produce as many as ___ virions (single virus cells). This number is called the ______ and will vary for each virus.

Fluid thioglycollate medium (FTM); resaruzin pink ; colorless; bottom

________ is a rich liquid medium that supports the growth of both aerobic and anaerobic bacteria. It also contains a dye called _______. This dye turns pink in the presence of oxygen. Since a higher oxygen concentration will occur at the surface of the medium, the medium will be _____ at the top and ______ in the middle and bottom. A small amount of agar is included in the medium to localize the organisms and favors anaerobic conditions in the_____ of the tube.

Bacteriophages

_________ are viruses that infect bacterial cells.

bacteriocidal.

agents that kill bacterial cells are termed__________

nucleocapsid; sheath; hollow

A phage consists of a ________, which is the nucleic acid and protein capsid. The nucleocapsid is attached to a protein _______ that is contractile and contains a _______ core in its center. The sheath sits on a base plate to which tail fibers and spikes are attached. Most of the phage's structure is necessary for delivery of the phage nucleic acid into its host.

negative

Another factor that affects the ability of an antibiotic to function is permeability. The outer membrane of Gram _______ bacteria acts as a permeability barrier and can restrict the entry of antimicrobials into the cell.

base plate

-Has tail fibers that are used for attaching to cells

Microaerophiles; Helicobacter pylori; Campylobacter

Aerobic bacteria that prefer 2-10% oxygen rather than the 21% found in the atmosphere. The lower oxygen concentration is necessary for their respiratory metabolism. ________ and ________ are pathogens found in the human gastrointestinal tract where the oxygen levels are lower than 20%.

sanitizers

Agents that reduce microbial numbers to a safe level but do not completely eliminate all microbes are defined as _______. These agents are used in the food industry to treat cooking equipment such as dishes and utensils.

True

All bacteria have 70S ribosomes. True or False

Brewer's Anaerobic Agar

An excellent solid medium for cultivating anaerobic bacteria, ___________contains thioglycollate, a reducing agent, and resazurin, an oxygen indicator. These compounds are included, because it is essential that obligate anaerobes be incubated in an oxygen-free environment.

colorless; blue

Anaerobic jars are used to provide an anaerobic environment for anaerobic petri plates. A GasPak capable of producing hydrogen is placed in the anaerobic jar. As hydrogen is produced, it combines with oxygen and forms water. An anaerobic indicator strip is placed in the anaerobic jar to make certain that an oxygen-free environment is achieved. The indicator is ________ under anaerobic conditions and is ______ in the presence of oxygen.

Obligate (Strict) Aerobe; Pseudomonas, Micrococcus, and many Bacillus.

Bacteria in this subgroup must grow in oxygen because their metabolism requires oxygen. These bacteria carry out respiration in which oxygen is used as the terminal electron acceptor in the electron transport chain. Examples are

D. both respiration and fermentation

Bacteria that are facultative anaerobes carry out metabolism by... A. respiration only B. bacteria do not metabolize substances for energy C. fermentation only D. both respiration and fermentation E. fermentation and neoglucogenesis

viruses; bacteria

Bacteriophages are ____ thar infect _____.

fermentation

Beer, wine, vinegar, buttermilk, cottage cheese, sauerkraut, pickles, and yogurt are some of the products of ________.

thermophiles

Camplobacter grows in guts of chickens and can cause food illness. These are examples of _____.

antiseptics or disinfectants.

Chemical agents that are used to control microorganisms can be defined as ____ or ______

semi-synthetics

Chemically altered antibiotics that are more effective than naturally occurring ones

antibiotics.

Diseases caused by Staphylococcus, Streptococcus, Pseudomonas, and Mycobacterium that once were fatal to humans became manageable and curable with the discovery of _____

21%

Oxygen makes up __% of the atmosphere on Earth

salvarsan; sulfa

Prior to the discovery of antibiotics, very few options were available to treat infectious agents except for some antimicrobial chemical compounds such as _____, an arsenic compound, and the _____ drugs, which were used with some success.

C. Serratia marcescens

Prodigiosin, a red pigment produced at a certain temperature range, is produced by... A. Staphylococcus aureus B. Streptococcus pyogenes C. Serratia marcescens D. Escherichia coli

Prodigiosin

Serratia marcescens produces a red pigment called ______ which grows in 25 degrees Celsius and has antibacterial and anti-tumor properties

True

Temperature extremes (below minimum and above maximum) can cause bacterial enzymes and membranes to lose function or to function inadequately. True or False

Kirby-Bauer; inhibition; 16 to 18

The __________ method is one way to determine the sensitivity or resistance of a bacterium to an antimicrobial. It is performed by uniformly streaking a standardized inoculum of the test organism on MuellerHinton medium, and then paper disks containing specific concentrations of an antimicrobial or antibiotic are deposited on the agar surface. The antimicrobial diffuses out from the disk into the agar, forming a concentration gradient. If the agent inhibits or kills the test organism, there will be a zone around the disk where no growth occurs called the zone of _______. After ____ to ____ hours of incubation, the plates are examined and the diameters of the zones of inhibition are measured to the nearest millimeter. Cultures are designated as resistant, sensitive, or intermediate in their response to the antibiotic.

Aerotolerant Anaerobes; fermentation; Streptococci; Streptococcus pyogenes

These anaerobes tolerate oxygen and grow in its presence, but they do not require oxygen for energy production. They use only ________ to produce energy. _______ that produce cheese, yogurt, and sour cream through fermentation and the pathogen _________ (causes strep throat) are examples

Facultative Anaerobe

They do prefer oxygen slightly though

pigment ; growth ; Serratia marcescens; Prodigiosin

This experiment will measure the effects of various temperatures on two physiological reactions: ______ production and _______ rate. One of the bacteria you will use is _______ which produces a red pigment called ______ which is an antibiotic and has been tested in clinical trials for the treatment of pancreatic cancer. It is only produced in a certain temperature range.

Facultative Anaerobes; Escherichia coli and Salmonella

This group of bacteria grows well in aerobic conditions, but can also grow anaerobically when oxygen is not available. Their flexible metabolism allows them to produce energy by carrying out respiration when oxygen is available (aerobic conditions), but if oxygen is not available they can produce energy via fermentation which does not require oxygen. ____ and ____ are examples

a supply of simple sugar, a supply of yeast, and anaerobic conditions.

Three conditions are necessary for fermentation to take place:

False

Three conditions are necessary for fermentation to take place: a supply of simple sugar, a supply of yeast, and aerobic conditions. True or False

hydrogen peroxide and superoxide

Toxic forms of oxygen (____ and ______) are commonly found in various environments and can damage biological molecules such as nucleic acids, proteins, and coenzymes

thermophiles

What type of bacteria are found in the soil?

Enzymes are directly affected by temperature and any one enzyme will have a minimum, optimal, and maximum temperature for activity.

Why can bacteria only grow in certain temperature ranges?

alcoholic; Saccharomyces cerevisiae var. ellipsoideus

Wine is essentially fermented fruit juice in which _____ fermentation is carried out by_____________

synthetics ; synthetics

_____-Some antimicrobials are chemically synthesized in the laboratory and are not produced by microbial biosynthesis. The sulfa drugs are _____ that were used to treat some bacterial diseases before the discovery of penicillin

antimicrobials ; Antibiotics ;

_______ are compounds that kill or inhibit microorganisms. ________are antimicrobials, usually of low molecular weight, produced by microorganisms that inhibit or kill other microorganisms. Two common examples are penicillin and streptomycin.

Catalase ; Peroxidase; superoxide dismutase

_______ degrades hydrogen peroxide to oxygen and water. ______ also degrades hydrogen peroxide. Superoxides are converted to oxygen and hydrogen peroxide by ________.

Broad-spectrum

________ antimicrobials are effective against both gram positive and gram negative bacteria

Disinfectants; ethylene oxide

________ are chemical agents that are applied to inanimate objects such as floors, walls, and tabletops to kill microorganisms. They are usually harsher than antiseptics and are therefore damaging to living tissue. Some disinfectants are classified as sterilants or sporocides, which means that they destroy all microbial life, including endospores. An example is ______, a gas that is used to sterilize heat-sensitive objects such as plastic petri plates, plastic pipettes, plastic syringes, and some surgical instruments that cannot be exposed to high temperatures.

Antiseptics

________ are substances such as alcohol or betadine that inhibit microbial growth or kill microorganisms and are gentle enough to be applied to living tissue. However, these compounds do not destroy endospores. They are used for hand washing, treating surface wounds on the skin, and preparing the skin for invasive procedures such as incisions and inoculations to prevent infections by opportunistic skin bacteria.

broad;

antibiotics that target 70S ribosomes tend to be ______ spectrum because all bacteria have 70S ribosomes, which are necessary for protein synthesis

Obligate (Strict) Anaerobes; nitrates and sulfates; Clostridium

are harmed or killed by oxygen. To survive, these bacteria must be cultured in conditions where oxygen has been totally eliminated. These organisms carry out fermentation(to make energy_, in which inorganic compounds, such as ____ and ______, take the place of oxygen in electron transport as the terminal electron acceptor. found in the soil, the rumen of cattle, and in septic systems. ________ is an example

hyperthermophiles

bacteria found in thermal vents

obligate (strict) anaerobes

die from oxygen exposure because they do not produce catalase

Aerotolerant anaerobe

evenly distributed

yeast+glucose --> ethanol+CO2

fermentation reaction for wine:

Psycrophiles

optimal growth between -5°C and 20°C. These bacteria can be found in the icy waters of the Arctic and the Antarctic.

Mesophiles

optimal growth between 20°C and 50°C. Most bacteria fall in to this category. For example, most pathogens grow between 35°C and 40°C.

Thermophiles

optimal growth between 50°C and 80°C. Bacteria in this category occur in soils where the midday temperature can reach greater than 50°C or in compost piles where temperatures exceed 60-65°C.

Hyperthermophiles

optimal growth is above 80°C. These organisms have been isolate from thermal vents deep within the ocean floor and from volcanic heated hot springs.

psychotrophs ex:Listeria

psychotrophs are not to be mistaken as pyschrophiles. Pyschrophile live and prefer the cold, _____ tolerate the cold

virons

single virus cells

Escherichia coli B; E. coli K12

the T-even (T2, T4, etc.) bacteriophages infect ___________, whereas phage T4 infects _______, a different strain of the organism. A phage that infects Staphylococcus aureus does not infect E. coli and vice versa.

spike

used to penetrate the cell wall

red; white

wine is produced in two forms: red and white. To produce ______ wines, the distillers use red grapes with the skins left on during the initial stage of the fermentation process. For____ wines, either red or white grapes can be used, but the skins are discarded. White and red wines are fermented at 13°C (55°F) and 24°C (75°F), respectively

plaques

•If the phage is applied to a bacterial lawn that is susceptible to the phage, this will cause _____, clearing in the agar

sheath

•Protein_______ has contractile mechanisms to inject its DNA or RNA into the cell Has a hollow core

Brewer's Anaerobic Agar

•Solid medium for cultivating anaerobic bacteria. •Contains thioglycollate (reducing agent) and resazurin (oxygen indicator) •Creates an oxygen free environment when used with an anaerobic jar. •Anaerobic jars (at front) with a GasPak to produce hydrogen gas (combines with O2 to make H2O).

Fluid Thioglycollate Medium (FTM)

•Supports the growth of aerobic and anaerobic bacteria •Glucose, cysteine, and sodium thioglycollate reduce oxidation/reduction potential. •Resaruzin dye turns pink in the presence of oxygen. •Small amount of agar is included to localize bacteria.

Phage typing; Phage therapy

•_____- can help determine infectious strains within a species of bacteria •______ has been used to treat antibiotic resistance

Alexander Fleming

•_______ discovered Penicillin in 1929 after mold (Penicillium) inhibited growth of Staphylococcus aureus. •Purification a few years later •First antibiotic used as a clinical treatment of bacterial infections

Prodigiosin

•________ exhibits antibacterial and anti-tumor properties.

Pseudomonas aeruginosa ; pyocyanin;

•__________ produces the blue-green pigment _________, a probable virulence factor •Found in large quantities in burn patients and cystic fibrosis patients infected with this bacteria

Pseudomonas fluorescens ; pyoverdin

•_________produces the fluorecent (under UV light) pigment ______, a virulence factor •Toxic •Assists in biofilm formation