LESSON 5 [B] Flashcards
this phylum is a collection of gram-positive, spore forming, obligate anaerobes, and cocci- or rod-shaped bacteria, including the Enterococcaceae and Lactobacillaceae families and the Streptococcus genus
Firmicutes
this order includes lactic acid bacteria and are widely used in food production and preservation; lack prophyrins and cytochromes and do not engage in oxidative phosphorylation; most are aerotolerant anaeorbes capable of growing in the presence of oxygen
Lactobacillales
Genus of Lactobacillales
Lactoccocus, Streptoccocus, Enterococcus, Peptococcus, and Peptostreptococcus.
the metabolism of Lactobacillales primarily relies on ______; they have limited biosynthetic abiltiies, requiring external sources of amino acids, vitamins, purines, and pyrimidines.
sugar fermentation
it is a type of fermentation process that produce only lactic acid
Homofermentative
Type of fermentation process that produce ethanol, CO2 and lactate along with lactic acid
Heterofermentative
It is a prominent genus known for its rod-shaped bacteria commonly found in dairy products and used in fermentation
Lactobacillus
what is the main endproduct of Lactobacillus?
Lactic acid
WHat is the fermentation pattern of lactobacillus?
homofermentative
They are acid-resistant, able to grow in low pH conditions, ad can be selectively enriched from dairy 0products and acidic plant materials; plays a key role in lactic acid fermentation and is often used as probiotic
Lactobacillus
a species of lactobacillus that is used in acidopholus milk production
Lactobacillus acidophilus
a species of lactobacillus that is used in yogurt preparation
Lactobacillus delbrueckii
these are the genera under lactobacillales that are coccoid- shaped lactic acid bacteria; some species are pathogenic to humans and animals.
Lactoccocus and Streptoccocus
they play roles in production of buttermilk, silage, and other fermnented products; characteristic cell morphology of coccci in chains or tetrad; some species contibutes to the formation of dental caries
Streptococcus
what type of fermentation pattern does lactoccous and streptococcus exhibit?
Homofermnetative
a genus of homofermentative cocci that contains streptocci of dairy significance
Lactococcus
Includes streptococci primarily of fecal origin; can be human pathogens
Enterococcus
Obligate anaerobes; ferment proteins rather than sugars
Peptococcus and Peptosreptococcus
2 subgroups of Streptococci
Pyogenes and Viridans
subgroup of streptococci causing strep throat
streptococcus pyogenes
subgroup of streptococci causing dental caries
streptococcus mutans
Hemolysis on Blood agar of Pyogenes subgroup
complete red blood cell hemolysis (B hemolysis)
Hemolysis on Blood agar of Viridans Subgroup
incomplete hemolysis (alpha hemolysis) leading to greening of the agar under colonies
Human b-hemolytic streptococci usually contain the group ____ antigen
group A
Enterococci contain the group _____ antigen
Group D
more resistant to acidic conditions compared to other lactic acid bacteria; can grow well at pH values as low as 4
lactobacillus
its features is produce flavoring ingredients diacetyl and acetoin from citrate catabolism; used as starter cultures in dairy fermentations; some strains produce glucose or fructose polysaccharide slimes, used as plasma extenders in blood transfusions.
Leuconostoc
key genera of bacillales
Listeria, Staphylococcu, Sarcina (nonsporulating)
causes major foodborne illness called listerious; contaminated, usually ready to eat fooods like cheese and sausage
Listeria
relatively resistant to reduce water potential; tolerates drying and high salt fairly wel; abilty to grow in meadia containing Nacl
Staphylocccous
species of staphyloccous that is non pogmented; ussually found on the skin or mucous membrans
staphylooocus epidermis
