Living together of organisms
Four types of Symbiosis
Commensalism, Mutualism, Pathogenesis and Parasitism
A symbiotic relationship in which one organism, benefits and the other is neither helped nor harmed.
Relationship in which both organisms benefit.
Relationship in which one organism is harmed. (the pathogen may or may not grow outside of host)
One organism is harmed ( parasite can not grow outside of host)
2 Examples Mutualism
Lichen, Bovine Rumen
fungi, green algae, and/or cyanobacteria.
In Lichen Green algae/ cyanobacteria provide
carbon source for fungi
In Lichen Fungi provides
water, minerals and substratum
Harbours bacteria that digest cellulose and other plant polysaccharides.
What bacteria does in bovine rumen
allow host to obtain nutrients from grass/grain.
Example of Commensalism
E. coli with anaerobes like bacteriodes in the intestine.
The important role intestinal flora play in human nutrition.
Vitamin synthesis, digestion of polysaccharides.
Commensal/Mutualistic bacteria of the skin
Staphylococcus and Strptococcus spp.
Commensal/Mutualistic bacteria of the Oral Cavity
Streptococcus, Fusobacterium and Actinomyces spp.
Commensal/Mutualistic bacteria of the upper respiratory tract
Streptococcus, Staphylococcus, Neisseria meningitidis
Commensal/Mutualistic bacteria of the GI tract
Lactobacillus, Bacteriodes, Bifidobacterium, Clostridium, Escherichia, Enterococcus
Anaerobes in large intestine
Bacteriodes, Bifidobacterium, and Clostridium
Bacteria adapted to stomach's low pH
Enzyme used for acid tolerance by Helicobacter
Require molecular oxygen and final electron acceptor is oxygen.
Prefer absence of oxygen. also known as fermentation
Final electron acceptor in anaerobic respiration
is exogenous, e.g. nitrate, sulphate.
Electron acceptor in fermentation
ATP is synthesized by substrate level phosphorylation.
Can grow with or without oxygen
require little oxygen but not too much
Require increased levels of carbon dioxide.
-5 to 17 degrees
-2 to 35 degrees
15 to 45 degrees
42 to 80 degrees
65 to 105 degrees