Module 3 Flashcards
Antisepsis
refers to the destruction or inhibition of microorganisms on living tissue. Because they are used on humans, agents are generally not as toxic as disinfectants
Acidophiles
species with their growth optimum between pH 0 and 5.5 (low or acidic pH)
Aerobes
a microorganism which grows in the presence of air or requires oxygen for growth.
Aerotolerant anaerobes
organisms that use fermentation to produce ATP rather than oxygen, but they can protect themselves from reactive oxygen molecules.
Alkaliphiles/alkalophiles
species with their growth optimum between pH 8.0 and 11.5 (high or basic pH)
Anaerobes
any organism that does not require oxygen for growth
Archaeal cell cycle
occurs in stages much like eukaryotic cells, with a distinct G1, S, G2 and segregation phase
Autoclave
a machine that uses steam under pressure to kill harmful bacteria, viruses, fungi, and spores on items that are placed inside a pressure vessel. The items are heated to an appropriate sterilization temperature for a given amount of time
Bacterial Cell Cycle
Growth
chromosome replication
cytokinesis
Barotolerant
organisms that tolerate high pressure environments
Batch Culture
culture technique in which microorganisms and nutrients are left for a set period of time, during which the nutrient stock is depleted
Binary fission
a relatively simple type of cell division where a parent cell divides into two equivalent daughters.
Biofilm
clusters of bacteria that are attached to a surface and/or to each other and embedded in a self-produced matrix
Cardinal temperatures
the minimum, optimum, and maximum growth temperatures unique to each organism.
Chemical microbial biocides
chemicals used to control microorganisms, including: Phenolics, Alcohols, Halogens, Heavy metals, Quaternary ammonium compounds, Aldehydes, and Sterilizing gases.
Chemostat
in continuous culture systems, it is a device to which fresh medium is continuously added, while culture liquid containing left over nutrients, metabolic end products and microorganisms are continuously removed at the same rate to keep the culture volume constant.
Colony forming units
a measure that indicates the number of cells that remain viable enough to proliferate and form small colonies
Compatible solutes
solutes produced by halotolerant/halophile organisms, creating a high enough concentration of solutes within the cell that water will flow into the cell rather than out.
Complex/rich medium
a culture medium rich that contains materials of biological origin such as blood or milk or yeast extract or beef extract, the exact chemical composition of which is obviously undetermined.
Continuous culture
culture technique in which are nutrients added and product is removed at a steady rate throughout.
Culture media
or growth medium is a liquid or gel designed to support the growth of microorganisms.
Cytokinesis
the physical process of cell division, which divides the cytoplasm of a parental cell into two daughter cells.
Decimal reduction time or D value
a common measure of the killing efficiency of a microbial agent; the time required to kill 90% of the microorganisms in a sample under the conditions tested.
Defined medium
also known as chemically defined medium or synthetic medium, is a culture medium in which all the chemicals used are known, no yeast, animal, or plant tissue is present
Differential media
a culture media that allows the investigator to distinguish between different types of bacteria based on some observable trait in their pattern of growth on the medium
Disinfection
the killing, inhibition, or removal of microorganisms that may cause disease; results in substantial reduction of the total of microorganisms that may cause disease.
Enriched media
a culture media that contains some component that permits the growth of specific types or species of bacteria, usually because they alone can utilize the component from their environment.
Facultative anaerobes
organisms that make ATP by aerobic respiration if oxygen is present, but are capable of switching to fermentation if oxygen is absent
Flow cytometry
an instrument used to count cells directly; it creates a narrow flowing stream of the cells past a laser beam and detector that can count how many cell particles pass across the detector per unit volume of the culture applied
FtsZ
a protein that assembles into a ring at the future site of bacterial cell division
Growth-arrested state
in most established environments, microbes have done their sprint of growth exist in this state, awaiting their chance to rapidly replicate again
Halophile
Salt loving
Hyperthermophiles
species with their growth optimum at very high temperatures
Ionizing radiation
consists of subatomic particles or electromagnetic waves that have sufficient energy to ionize atoms or molecules by detaching electrons from them.
Mesophiles
species with their growth optimum at midrange temperatures
Microaerophiles
a microorganism that requires oxygen to survive, but requires environments containing lower levels of oxygen than that are present in the atmosphere.
Microbial growth curve
growth of microorganisms in a semi-logarithmic plot show this characteristic pattern, which includes a lag phase, exponential phase, stationary phase, death phase, and long-term stationary phase
Microbial-cidal
refers to antimicrobial agents that kill microbes
Microbial-static
refers to antimicrobial agents that inhibit microbes
Neutrophiles
species with their growth optimum between pH 5.5 and 8.0 (midrange or neutral pH)
Obligate aerobes
organisms that requires oxygen to grow
Pasteurization
a process in which packaged and non-packaged foods are treated with mild heat, usually to less than 100 °C, to eliminate pathogens and extend shelf life.
Penicillin-binding proteins (PBPs)
are involved in the synthesis of peptidoglycan in the bacterial cell wall, and are the targets of the penicillin family of antibiotics.
Piezophilic
species with their growth optimum in high pressure environments
Pour plate
a method of inoculating a solid medium by mixing the microbes with melted medium (such as agar), and pouring the mixture into a Petri plate to solidify
Psychrophiles
species with their growth optimum at low temperatures
Psychrotolerants
species that can tolerate life at low temperatures
Sanitization
the reduction in levels of microbes to levels that are considered safe by public health standards; typically refers to inanimate objects
Selective media
a culture media that has a component(s) added to it which will inhibit or prevent the growth of certain types or species of bacteria and/or promote the growth of desired species.
Septum
a cross wall produced between daughter cells during binary fission
Spectrophotometer
an instrument that measures the amount of photons (the intensity of light) absorbed after it passes through sample solution; it can be used to measure cell mass in a sample
Spread plate
a technique to plate a liquid sample containing bacteria so that the bacteria are easy to count and isolate. A successful spread plate will have a countable number of isolated bacterial colonies evenly distributed on the plate
Sterilization
meaning killing or removing all living cells, spores, and acellular entities such that objects are completely free of viable microorganisms, spores, and other infectious agents.
Streak plate
a common method for the isolation of a pure culture from a mixture, the inoculum is streaked over the agar surface to isolate colonies on at least a portion of the plate.
Strict anaerobes or obligate anaerobes
organisms that use fermentation to produce ATP rather than oxygen, and are harmed by reactive oxygen molecules
Supportive media
a culture media that contains additional ingredients, such as red blood cells, which support the growth of more fastidious (picky) bacteria.
Thermophiles
species with their growth optimum at high temperatures.
Turbidostat
in continuous culture systems, it is a device which has feedback between the turbidity of the culture vessel and the dilution rate of the media.
Tyndallisation
a process dating from the nineteenth century for sterilizing substances, usually food, that can be used to kill heat-resistant endospores. Although considered old-fashioned, it is still occasionally used.
UV radiation
a form of electromagnetic radiation with wavelength from 10 nm to 400 nm, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight
