Biofilma and nature

Question 1

What does biocorrosion caused by bacteria result in ?

Answer 1

pitting, crevice corrosion, stress corrosion cracking

Question 2

What are the REDOX changes across a biofilm?

Answer 2

high O2 in outer and lower O2 a the base of the biofilm = causing pitting process on the metal

Question 3

Biofilms have characteristics which cause retention of what?

Answer 3

exoenzymes and nucleic acids ( = large gene pool)

Question 4

What does the presence of alginate cause ?

Answer 4

cells stick together from the beginning and form clusters then form into mushrooms

Question 5

How do biofilms release nutrients for other cells to benefit from?

Answer 5

by being autotoxic

Question 6

What is the long distance range for initial attachment ?

Answer 6

5-20nm

Question 7

What is the short distance range for initial attachment ?

Answer 7

0.2-2nm

Question 8

What are the two theories of attachment at short distances?

Answer 8

A. non specific binding ( hydrophobic, hydrogen, ion)
B. Specific lock and key binding

Question 9

What are the features of fimbriae ?

Answer 9

large variations between species
2-10nm in width
4um in length
identical subunits half together by H bonds and hydrophobic interactions
Many subunits