Chapter 2_FIM_Food Microbiology

pedococcus sp.

bacteria used in meat fermentation, vegetable fermentation, ripening of some cheese

escherichia coli

fecal coliform. causes gi disorders

Haloduric

salt tolerant microorganism

Brucella

Mammalian parasites and pathogens; found in unpasteurized milk

E. Coli

A fecal coliform where some strains can cause food poisoning

Enterohemorrhagic E. coli (EHEC):

EHEC is known for producing a toxin called Shiga toxin. Infections can lead to bloody diarrhea, abdominal pain, and, in severe cases, a complication called hemolytic-uremic syndrome (HUS), which can cause kidney failure and other serious health issues.

Lactococcus lactis and Streptococcus thermophilus

bacteria used in dairy fermentation

leuconostoc sp

bacteria used in wine making and dairy fermentation

lactobacillus sp.

meat, veg, dairy, sourdough fermentation

Bifidobacterium sp

added to dairy products to promote intestinal health

Propionibacterium sp

swiss cheese fermentation

lactobacillus delbruekii and streptococcus thermophilus

bacteria used in making yoghurt

Thermophiles

an organism capable of growth at high temperatures; produce spores that are heat-resistant

Psychotrophs

an organism able to grow at low temperature

Acidophiles

microbes able to grow in acidic environment

soil and water, plants, animals , air, food processing equipment and ingredients

sources of microbes in food

Virus

Infectious agent having a simple acelllular organization with a protein coat and a single type nucleic acid, lacking independent metabolism and reproducing only withing living host cells

ex of diseases caused by viruses(poliomyelitis, hepa a, viral gastroenteritis)

coxiella burnetti

q fever causer. infected milk

chlamydia psittaci

from infected poultry. causes Psittacosis

Bacteria

organism intermediate to virus and fungi in size; it is unicellular of multicellular prokaryotic organism

bacillus

rod shaped

spirilla

helical shaped

vibrio

curved rod shaped

Fungi

may be unicellular or made up of tubular filaments(hyphae) and lacks chlorophyll. included in this class are molds, yeasts and fungi

Campylobacter

cause of gastroenteritis

brucella

found in pasteurized milk. causes brucellosis.

alteromonas

spoiled chicken and fish. produces strong ammonia odors

Acetobacter

found in alcoholic beverages where the convert alcohol to acid causing souring

Flavobacterium

involved in spoilage of milk and milk products

halobacterium

bacteria that can tolerate salt >12%

Salmonella

causative organism for food poisoning

Serratia

cause the characteristic red rot spoilage of eggs

shigella

pathogen that causes shigellosis

vibrio

cholera causer linked to shellfish

micrococcus

principal spoiler of salted food

Staphylococcus Aureus

important food poisoning organism. Staph food poisoning. gastroenteritis causer

pediococcus

LAB. bacon and vacuum food spoiler

Clostridium botulinum

anaerobic and spore formers. causes botulism

Listeria monocytogenes

causes listeriosis. aerobic or facultatively anaerobic

mcg of concern for low temp preservation

Molds

multicellular and filamentous form of fungi that can grow on almost any substance used for food. some produce mycotoxin

Mycotoxins

Poisonous toxins produced by molds

Yeasts

single-celled organisms of economic importance in brewing and bread making industry

Algae

group of relatively simple plants with unicellular reproductive structure; possess the green photosynthetic pigment, chlorophyll A

pyrrophyta

dynoflaggelates that cause red tide

Protozoa

unicellular eukaryotic microorganisms that lack cell walls.

Entamoeba histolytica

protozoa that causes amebiasis

helminthic eggs and larvae

gastrointestinal parasites. Examples are Trichinella spiralis and anisakis spiralis

Trichinella spiralis

helminth that causes Trichinellosis/Trichinosis

anisakis spiralis

causes anisakiasis. from fish

Lag phase

little or no apparent growth for a period following the initial contact between the microbes and the enviroment

Exponential phase

phase wherein microorganisms are growing and dividing at the maximal rate

Stationary phase

phase wherein there is no net increase or decrease in cell number

Death phase

decline in the number of viable cells

Generation time

is the time it takes for a population of bacteria to double in number

6.5-7

neutral

general optimum pH of most pathogenic bacteria

true

true or false. molds and yeasts are somewhat resistant to pH conditions

decreases

as osmotic pressure increases(high solute concentration) what happens to Aw(water activity)

Halophiles

an organism that grows in high concentration of salt

Osmotolerant

organisms that can grow over a fairly wide range of Aw or solute concentrations

stenothermal

organisms with a narrow temp range for growth

euthermal

organisms with a wide temp range for growth

psychrophiles

organisms that can grow at subzero to 20C(10-15 optimum)

psychotrophs

organisms that can grow at or below 7C(20-30 optimum)

mesophiles

organisms that grow well at 20-45C(30-40 optimum), room temp organisms. common spoilage organisms

thermophiles

can grow well at and above 45C(Optimum at 55-65C). heat resistant spores. spoilage in thermally processed food

obligate aerobe

organisms that require oxygen for growth

facultative aerobe

organism that grow best with oxygen but can live and growth without it

anaerobes

organisms that can grow without oxygen

microaerophilic

aerobic organisms that can grow in low levels of oxygen(2-10%)

true

true or false. most yeasts are aerobic and some are facultatively anaerobic

true

true or false most molds are mostly aerobic

controlled atmosphere(CA)

method of controlling growth of microbes by altering the proportion of gases. Ex increasing CO2 and reducing O2

modified atmosphere(MA)

like CA but less controlled or not as strictly maintained.

intrinsic factors

characteristics of the growth substrate(pH, moisture, redox potential, nutrient content, antimicrobial constituents, biologic structures)

extrinsic factors

imposed from the outside(humidity, temp, gas composition)

Disinfection

killing, inhibition or removal of all microbes that may cause disease using a disinfectant

Sterilization

a process that kills or removes all forms of microbial life situation which results to complete absence of live microorganism

Antibiotic

a microbial product or derivative that kills of inhibits growth of a susceptible microbe

Food-borne infection

results from ingestion of pathogen-containing food

Food-borne intoxication

results from ingestion of foods containing preformed microbial toxins

Carbon dioxide

causes the gluten network to expand and later be set free during baking

Campylobacter Jejuni, Escherichia coli, Listeria monocytogenesis, Salmonella spp., Vibrio parahaemolyticus, Yersinia enterolitica

common food intoxication organisms

Yersinia enterolitica

linked to milk . causes plague

Aspergillus flavus

linked to peanuts

Produce aflatoxin

Causes hepatoxicity

Bacillus cereus, Campylobacter botulinum, clostridium perfingens, staph aureus

common food poisoning organisms

P. roqueforti

mcg for blue cheese ripening

maltose

starch->acted by flour enzymes->___________

glucose

maltose->acted by yeast enzymes->________

Sacharomyces carlsbergensis

bottom yeast in beer making

alcohol + CO2

glucose->fermented by yeast->_____+_______

acetic acid + water

alcohol->oxidation by acetic acid organisms->____+____

peptides

conversion of protein to ______ by proteinases may give bitter taste

S. cerevisiae

yeast more commonly utilized for the conversion of glucose and any fermentable carbohydrates to alcohol and CO2

Pyrrophyta

dinoflagellates (red tide)

Entamoeba histolytica

causes amoebic dysentery

Trichinella spiralis

Found in wild game or pork

Anisakis spiralis

Cod fish work or seal worm; found in fish

40-65 ˚C

Thermophiles grow in this temp

20-45 ˚C (RT)

Mesophiles

< 20 ˚C

Psychrophiles