What microorganism is commonly used in beer and bread production?

Saccharomyces cerevisiae

During the making of Swiss cheese, first lactose is fermented by __________ and in syntropy, ___________ is the secondary fermenter that produces propionic acid and carbon dioxide from lactate

Lactobacillus, Propionibacterium

Why are fermented foods considered “good” for human consumption?

Microbes that are alive inoculate into the intestine creating higher
gut diversity.
Microbes that are not alive contain fermented macromolecules
that are easy to digest.
Microbes found in fermented food help the human body fight
pathogens

The rate at which food can spoil is impacted most by

water content

An example of “perishable” a food includes

meat

To prevent microbial growth in food products, preservation strategies to reduce microbial growth are commonly used such as

the inclusion of sodium propionate or benzoate.
pickling to increase salt concentration and acidity in the environment.
pasteurization to inactivate any pathogens that may be present in
food.

Food poisoning and food infection are the same thing and
terms can be used interchangeably.

false

What is not an organism that can cause food infection?

Clostridium

Why is it not advised to eat food that has been sitting out at room temperature for prolonged periods of time even if the food is reheated?

The food can contain active microbial toxins even if the microorganism that produced it is dead

Which term overall best describes the relationship between the human body and its microbiome

Symbiotic

No matter where in the human body (skin, intestine, stomach), relatively, the same number of microorganisms will be found

false

The oral microbiota consists strictly of aerotolerant organisms

false

Which bacteria is commonly associated with human mouth flora

Streptococcus

Streptococcus pyogenes is a pathogen that commonly causes

Strep throat

Preventing young children from exposure to microorganisms is the
best way to develop a healthy immune system

false

What is not an example of something that would affect the
composition of skin microbiota?

smoking tobacco

The colonization of newborn guts is critical to for their health outcome in the future. What are some common bacteria found in healthy newborn guts?

bifidobacteria and enteric bacteria

Why might including probiotic food in your diet after pro-longed antibiotic use be beneficial?

introduces more diversity into gut microbiome

There is a higher number of microorganisms found in the _________
microbiota compared to the intestinal microbiota __________

small intestine, stomach

Conditions that affect the gut microbiome often have links between
secondary conditions such as obesity, heart disease, and high blood
pressure

true

Individuals who have Inflammatory bowel disease (IBD) may be more likely to experience anxiety and depression due to

the gut-brain axis

Louis Pasteur’s swan neck flask experiment disproved the theory of

spontaneous generation of life

You have isolated a bacterium that you believe to be the causative agent of a new disease in mice. How would you test it along the lines of the Koch’s postulates?

Isolate the bacterium from a sick mouse and inject it into healthy mice to see if it causes the same disease

Which of the following is NOT an example of practicing aseptic or sterile technique?

cutting watermelon on a disinfected cutting board

Sterile or aseptic technique includes all of the following, except
a. utilizing sterile media to control growth of microorganism in a sterile environment
such as a petri dish.
b. applying a series of practices to avoid contamination and guarantee organism
containment.
c. employing an autoclave and other sterilization procedures.
d. Never working in teams to prevent possible contamination

don't work in teams

What is the correct order of phases when bacteria are inoculated into a new culture?

Lag, exponential, stationary, death

You are working with a media with a high salt concentration that only allows bacteria that can withstand high salt environments to grow. This means this is differential media

false

You are interested in isolating Staphylococcus aureus from a soil sample found outside of Franklin Dining Commons. What would be the best method for isolating this bacteria?

steak plate

Listeria monocytogenes is a pathogenic bacteria that infects the intestinal tracts of humans. Therefore this organism is considered a

mesophile

mesophile

organism that grows best in moderate temperature, neither too hot nor too cold

Genetic engineering allows scientists to alter genes in the lab using in vitro
techniques such as
a. Polymerase Chain Reaction (PCR)
b. Molecular cloning
c. Mutagenesis
d. All of the above

all

What are two key components needed to run a standard PCR protocol?

DNA template, Forward and Reverse Primers

Which of the following steps in PCR does the docking of DNA polymerase onto the DNA occur?

warming (72 degree C)

What is the is the main goal of conducting genetic cloning?

To insert a gene of interest into a bacterium and have it express that protein

You are working on a cloning project and want to insert a gene into a plasmid that allows the bacteria to grow on mannitol agar. What enzymes are used to make double stranded breaks in the plasmid thus allowing the gene to anneal and ligate in?

Restriction endonucleases

Which is NOT a correct example of a organic pollutant?

uranium

Uranium 4+ is not water soluble while Uranium 6+ is water soluble

true

When microorganisms are used to prevent the transport of uranium in water from uranium-contaminated sites they use the uranium 6+ as an electron __________ during anaerobic respiration

acceptor

What are some concerns when it comes to xenobiotic compounds, such as plastics, being found in natural environments?
a. For many, there is no known way to degrade these products
b. Extremely diverse in chemical composition
c. Can be further fragmented into smaller components allowing to enter the food chain
d. All of the above

all

Why is it important for human health for there to be wastewater treatments in place?
a. Waste water contains vast amounts of organic load that is toxic to humans.
b. Some pathogens are able to persist and transmit through wastewater.
c. To help improve over quality and taste of water.
d. All of the above.

all

What occurs during primary treatment of wastewater?

Wastewater is passed through a series of grates with organic and inorganic particles settling on the bottom.

Wastewater contains large amounts of microorganisms that can pose a threat to human health. What are some other active biological pollutants that are also being released into wastewater coming into concern?
a. Sunscreen
b. Pharmaceuticals
c. Personal care products
d. All of the above

all

Louis Pasteur

1822–1895

discovered that alcoholic fermentation was a biologically
(not just chemically) mediated process

developed vaccines for anthrax, cholera, and rabies

swan neck

Robert Koch

1843–1910

developed solid media for obtaining pure cultures of microbes

observed that masses of cells (called colonies) have different
shapes, colors, and sizes

experimentally demonstrated the link between microbes and
infectious diseases

Defined media

exact chemical composition form of nutrients is known

Complex/Undefined media

composed of boiled or pre-digested microbial, animal, or plant products, diverse/random/unknown bioavailable nutrients

Selective

Add substance(s) to inhibit the growth of particular, unwanted microbes

Differential

Add substance(s) to visualize biochemical reactions of particular microbes

Obligate aerobes

require oxygen and grow at full oxygen strength (20%)

Obligate anaerobes

oxygen is lethal

Facultative anaerobes

can respire (prefer) oxygen when present, use alternative ways when absent

Microaerophiles

can use oxygen only when it is present at levels lower than in air due to limited respiration or moderate oxygen sensitivity

Aerotolerant

do not use oxygen for growth at all, but are also not harmed by its presence

Caldicellulosiruptor

gram-positive anaerobic thermophile that produces a cellulase converting complex switchgrass cellulose to glucose

E. coli is a bacterium that respires with oxygen or nitrate. What best described its lifestyle?

facultative anaerobe

Robert Koch and Louis Paster used the principle of nutrient media and sterilization to demonstrate that despite microorganisms being inevitable we can control them.

true

A colony on an agar plate is considered a pure culture because those millions of cells in the colony have originated from a single cell that grew isolated from other cells on that spot where the colony appeared.

true

This is the recipe for a nutrient medium to grow bacteria. Is this a medium of the defined or undefined (complex) category?

5 g yeast extract

5 g peptone

2 g KH2PO4

Distilled water 1000 ml

pH 7

complex

Which of the following terms describes procedures to avoid the spread of microorganisms.

sterile technique

Before the discharge water can be released from the wastewater treatment plant into a natural water body like a river it must be

disinfected to kill the microorganisms.

The seeping of oil and gas from fossil fuel reservoirs is a natural phenomenon, and at these natural seeps sites we can find microbial communities that are especially adapted to using hydrocarbons as electron donors.

true

Organic compounds with my chlorine groups (polychlorinated), such PCB, are very ________ to be degraded by microorganisms, and _________

hard / for some polychlorinated compounds natural degrading mechanisms don't even in exist.

Tertiary wastewater treatment generates which of the following gases in quantities sufficient for recovery as fuel?

methane

Which of the following statements is correct?

Bacillus subtilis is a model organism for Gram-positive bacteria and E. coli is a model organism for Gram-negative bacteria.

The polymerase chain reaction has many cycles of three temperature steps: 95°C, 55°C, and 72°C. At the 95°C stage,

DNA denatures

Mesophilic organisms prefer growth in a temperature range of

Celsius: 20-40

EcoRI is a restriction endonuclease enzyme that recognizes a six base-pair DNA sequence and

breaks dna strands

The biological oxygen demand is a metric to indicate the capacity of microbes to

oxidize all organic matter present in an environment.

High levels of organic and inorganic materials in wastewater result in _________ levels of biochemical oxygen demand (BOD).

high

X-gal is

an indole dye covalently bound to a sugar to mimic lactose, and a substrate for ß-galactosidase.

Sterilization by autoclaving completely destroys all microorganisms, but only endospores survive.

false

What describes best the lifestyle of a bacterium in relation to oxygen?

aerophilic

______________ are live bacteria that we consume with the intent that they survive the stomach acid and colonize / become part of our microbial community in the gut.

probiotic

Vinegar production requires a fermentation cascade, where the ethanolic fermenter is the _____ fermenter, and the acetic acid fermenter is the ____ fermenter.

primary, secondary