Microbiology of animals Flashcards
what are commensals?
microorganisms routinely found in the bodies of most healthy human
name 3 parts of the human body that are normally sterile
Lungs
internal tissues
Urinary tracts
why are animal bodies an ideal environment for the growth of micro-organisms
they ae warm, wet and potentially a good source of nutrients
factors that affect the richness and abundance of microorganisms
temperature, pH, nutrient supply and the immune system
how are commensal beneficial to the host
provide vitamins and metabolic pathways
provide protection again new icrooganisms: since they are already holding the territory
teach the immune system
name all the harmful relationships with microorganisms
Pathogens infection disease pathogenicity virulence opportunistic pathogen: causes disease only in the absence of normal host resistance
in what part of animal is the most of microorganisms found
GI tract
name the insoluble polysaccharides that herbivores consume
Cellulose
lignin
hemicellulose
pectin
enzyme responsible for digesting cellulose
cellulase. Not produced by animals
Microorganisms in the GI tract of herbivores produce it.
2 functions of microorganisms in the GI tract
digest cellulose
provide nutrients
2 digestive strategies in herbivores
Foregut fermentation
HIndgut fermentation
processes in ruminant s
food is chewed minimally and then passes on to rumen her foregut fermentation occurs
conditions in the rumen
39-40 celsius
pH. 5-7
what controls the pH of the rumen.
Saliva that contains basic chemicals. Like sodium bicarbonate
sodium phosphate
what mediates fermentation in the rumen
cellulolytic microbes that hydrolyze cellulose to free glucose and cellobiose
what then happens to the sugars after fermentation
fermented to produce volatile fatty acids, methane andCO2
How dies the animal use fatty acids
they pass through the rumen wall into the bloodstream and are used as an energy source
identify the microorganisms of the rumen
ciliated protozoa,
bacteria, arched.
characteristics of methanogens
Strict anaerobes
The oxidise hydrogen gas
ferment acetate
10% of energy in cows is lost as CH4, when?
methanogens take up the acetate