Food Microbiology Exam queries and
answers graded A+
Food microbiology - ANS✅✅-a specialist category of microbiology (clinical, food, soil, rumen, and
industrial microbiology)
-beginnings were such that it was strongly involved with scientific curiosity and it wasn't until later
that its involvement with human health was understood
History of food microbiology - ANS✅✅-humans were originally hunter-gatherers
-food preservation and storage procedures were not adequately developed
-early preservation methods were most likely accidental (food left out in sun-dried, food left out in
winter-froze, and food that was heated in a fire-dried out of stored better)
7000 BC - ANS✅✅Babylonians manufactured beer (fermentation)
6000 BC - ANS✅✅the first apparent reference to food spoilage in recorded history
3000 BC - ANS✅✅Egyptians manufactured cheese and butter (fermentation, low aw)
1000 BC - ANS✅✅Romans used snow to preserve shrimp (low temp); records of smoke and
fermented meats also appear; also wine
Anton van Leeuwenhoek - ANS✅✅-Dutch; 1632-1723
-advanced the work of others on lenses, grinding and polishing his own, and invented the simple
light microscope (magnifying glass)
-called the "father of microscopy"
-the 1st to see microscopic cells in drops of water
-used the term, "animacules" protozoa, algae, yeast cells?
-he also sent his observations to the Royal Society in England where his work was heralded by other
scientists/naturalists
Robert Hooke - ANS✅✅-English; 1635-1708
-English naturalist/scientist; improved Leeuwenhoek's microscope design
,-first to use the word "cell" to describe the basic unit of life
-worked as an assistant to Robert Boyle (Boyle's Gas Law)
-responsible for annual discussions and demonstration of theories requested by members
-invented the compound microscope and wrote the book, Micrographia, from his observations
-the "cells" he saw were plant cells, easy to see because of their size, but nevertheless it was a great
observation on the basic unit of life
development of canning - ANS✅✅-1795 French government offered 12,000 francs to anyone who
could develop a practical way to preserve food
-winner was Nicholas Appert: issued a patent after showing that meat could be preserved when it
was placed in glass bottles and boiled
-he placed food in glass and sealed with cork/sealing wax, then boiled them in water to preserve
-this began food preservation by canning
-often called appertization--> involved cooking the food to a temperature in excess of what is used in
standard pasteurization and can destroy some of the flavor of the preserved food
spontaneous generation - ANS✅✅a hypothesis that living organisms arise from nonliving matter
by this process
biogenesis - ANS✅✅the alternative hypothesis that living organisms arise from pre-existing life, by
this process
Lazzaro Spallanzini - ANS✅✅-Italian; 1729-1799
-helped to disprove spontaneous generation by placing boiled meat into sealed containers to
prevent spoiling (prevented flies from generating maggots)
Louis Pasteur - ANS✅✅-French scientist; 1822-1895
-inquired why wine/milk soured
-swan-necked flask experiments showing that boiled media did not promote growth, thereby
disproving spontaneous generation and proving biogenesis (along with Spallanzini)
-developed the germ theory of disease that said microorganisms are the causative agents of
disease... but couldn't prove it
-he identified that fermentation is the result of microorganisms that cause the spoiling of wine, beer,
and milk
, -by understanding fermentation and the results of the swan flask experiments, he was able to
develop "pasteurization" by applying heat to liquids, killing most of the organisms within them and
prolonging the life of the product before eventually spoiling
pasteurization regimens (milk) - ANS✅✅-standard heating: 60 C or 140 F for 20 minutes
-high temperature short time (HTST): 72 C or 161 F for 15 seconds
-ultra high temperature (UHT): 140 C or 284 F for 4 seconds; considered sterilization, can keep
products at room temp on the shelf (brick-pack milk)
Robert Koch - ANS✅✅-German scientist; 1843-1910
-proved the "germ theory" of Pasteur with anthrax (Bacillus anthracis)
-relates a specific organism to a disease
-the steps are known as Koch's Postulates
-his spore work caused him to urge the sterilization of surgical instruments
Koch's Postulates - ANS✅✅1. observe same microorganism in all patients with similar disease (ex:
anthrax=rods in blood of all infected sheep)
2. isolate the suspected microorganism in artificial media in the lab
3. inoculate a healthy experimental animal and observe the experimental animal come down or
show signs and symptoms of disease
4. re-isolate the organism from the inoculated animal
-once the concept was established, it lead to the "Golden Age of Microbiology" whereby other
infection/illnesses were correlated to the causative infectious agent
Julius Petri - ANS✅✅worked in Koch's lab and invented the petri plate that was a glass dish that
could be re-used after sterilization in a hot air oven to culture cells
Fannie Hesse - ANS✅✅-a laboratory technician who worked in Koch's lab
-familiar with the use of agar in setting jams
-recommended it for use in petri plates to set the nutrient medium
petri plates and agar media - ANS✅✅used to enumerate and isolate organisms and further studies
into metabolic activities have lead to modern discoveries such as antibiotics (penicillin)
answers graded A+
Food microbiology - ANS✅✅-a specialist category of microbiology (clinical, food, soil, rumen, and
industrial microbiology)
-beginnings were such that it was strongly involved with scientific curiosity and it wasn't until later
that its involvement with human health was understood
History of food microbiology - ANS✅✅-humans were originally hunter-gatherers
-food preservation and storage procedures were not adequately developed
-early preservation methods were most likely accidental (food left out in sun-dried, food left out in
winter-froze, and food that was heated in a fire-dried out of stored better)
7000 BC - ANS✅✅Babylonians manufactured beer (fermentation)
6000 BC - ANS✅✅the first apparent reference to food spoilage in recorded history
3000 BC - ANS✅✅Egyptians manufactured cheese and butter (fermentation, low aw)
1000 BC - ANS✅✅Romans used snow to preserve shrimp (low temp); records of smoke and
fermented meats also appear; also wine
Anton van Leeuwenhoek - ANS✅✅-Dutch; 1632-1723
-advanced the work of others on lenses, grinding and polishing his own, and invented the simple
light microscope (magnifying glass)
-called the "father of microscopy"
-the 1st to see microscopic cells in drops of water
-used the term, "animacules" protozoa, algae, yeast cells?
-he also sent his observations to the Royal Society in England where his work was heralded by other
scientists/naturalists
Robert Hooke - ANS✅✅-English; 1635-1708
-English naturalist/scientist; improved Leeuwenhoek's microscope design
,-first to use the word "cell" to describe the basic unit of life
-worked as an assistant to Robert Boyle (Boyle's Gas Law)
-responsible for annual discussions and demonstration of theories requested by members
-invented the compound microscope and wrote the book, Micrographia, from his observations
-the "cells" he saw were plant cells, easy to see because of their size, but nevertheless it was a great
observation on the basic unit of life
development of canning - ANS✅✅-1795 French government offered 12,000 francs to anyone who
could develop a practical way to preserve food
-winner was Nicholas Appert: issued a patent after showing that meat could be preserved when it
was placed in glass bottles and boiled
-he placed food in glass and sealed with cork/sealing wax, then boiled them in water to preserve
-this began food preservation by canning
-often called appertization--> involved cooking the food to a temperature in excess of what is used in
standard pasteurization and can destroy some of the flavor of the preserved food
spontaneous generation - ANS✅✅a hypothesis that living organisms arise from nonliving matter
by this process
biogenesis - ANS✅✅the alternative hypothesis that living organisms arise from pre-existing life, by
this process
Lazzaro Spallanzini - ANS✅✅-Italian; 1729-1799
-helped to disprove spontaneous generation by placing boiled meat into sealed containers to
prevent spoiling (prevented flies from generating maggots)
Louis Pasteur - ANS✅✅-French scientist; 1822-1895
-inquired why wine/milk soured
-swan-necked flask experiments showing that boiled media did not promote growth, thereby
disproving spontaneous generation and proving biogenesis (along with Spallanzini)
-developed the germ theory of disease that said microorganisms are the causative agents of
disease... but couldn't prove it
-he identified that fermentation is the result of microorganisms that cause the spoiling of wine, beer,
and milk
, -by understanding fermentation and the results of the swan flask experiments, he was able to
develop "pasteurization" by applying heat to liquids, killing most of the organisms within them and
prolonging the life of the product before eventually spoiling
pasteurization regimens (milk) - ANS✅✅-standard heating: 60 C or 140 F for 20 minutes
-high temperature short time (HTST): 72 C or 161 F for 15 seconds
-ultra high temperature (UHT): 140 C or 284 F for 4 seconds; considered sterilization, can keep
products at room temp on the shelf (brick-pack milk)
Robert Koch - ANS✅✅-German scientist; 1843-1910
-proved the "germ theory" of Pasteur with anthrax (Bacillus anthracis)
-relates a specific organism to a disease
-the steps are known as Koch's Postulates
-his spore work caused him to urge the sterilization of surgical instruments
Koch's Postulates - ANS✅✅1. observe same microorganism in all patients with similar disease (ex:
anthrax=rods in blood of all infected sheep)
2. isolate the suspected microorganism in artificial media in the lab
3. inoculate a healthy experimental animal and observe the experimental animal come down or
show signs and symptoms of disease
4. re-isolate the organism from the inoculated animal
-once the concept was established, it lead to the "Golden Age of Microbiology" whereby other
infection/illnesses were correlated to the causative infectious agent
Julius Petri - ANS✅✅worked in Koch's lab and invented the petri plate that was a glass dish that
could be re-used after sterilization in a hot air oven to culture cells
Fannie Hesse - ANS✅✅-a laboratory technician who worked in Koch's lab
-familiar with the use of agar in setting jams
-recommended it for use in petri plates to set the nutrient medium
petri plates and agar media - ANS✅✅used to enumerate and isolate organisms and further studies
into metabolic activities have lead to modern discoveries such as antibiotics (penicillin)
