Biofuels/ Films

Front 1

Planktonic growth

Back 1

Single cell suspended in a medium or growing on a plate

Front 2

Biofilms

Back 2

Community of various types of microbes living together in a structured order. This reflects a more natural habitat than planktonic growth

Front 3

How are biofilms formed?

Back 3

1. Bacteria adsorb to the surface (reversible)
2. If they like the surface they attach themselves to the surface (irreversible)
3. The bacteria grows and forms a large colony
4. The colony produces exopolymers and biofilm
5. Other microbes attach to the biofilm and expand it

Front 4

Advantages of biofilms

Back 4

Exploiting biofilm production can lead to:
1. Biocontrol agents
2. Corrosion inhibitors
3. Bioreactors for sewage and wastewater treatment

Front 5

Disadvantages of biofilms

Back 5

1. Human diseases
2. Form on implanted medical devices

Front 6

Biofilm Biocontrol agents are?

Back 6

1. Bacillus subtilis
2. Erivinia
3. Psuedomonas
4. Salmenolla
5. E.coli

Front 7

Form biofilm in plant roots

Back 7

Bacillus subtilis

Front 8

Prevent pathogenic bacteria from colonizing plants by secreting surfactants

Back 8

Erwinia, psuedomonas, e.coli, salmonella

Front 9

Which bacteria controls virulence of erwinia and how?

Back 9

Bacillus thuringiensis by producing AHL-lactonase that degrades AHL and prevent quorum sensing that usually leads to formation of biofilms

Front 10

What is biocorrosion?

Back 10

Corroding of metal sufaces by microbes:
1. Sulfate reducing bacteria (Desulfosporosinus orientis)
2. Iron oxidizing bacteria (Leptothrix discopthera)

Front 11

Prevent biocorrosion?

Back 11

Use biofilm forming bacteria called Bacillus brevis that produce gramidicin-S that decrease corrosion 20-fold

Front 12

biofilms in bioreactors

Back 12

1.The microbes needed for reaction can be fixed/bound on the support in bioreactors (immobilized cell reactors). They will form biofilms that will be easy to use for treatment of sewage and waste water
2. Biological membrane reactor: the waste water crosses the biomembrane to reach biofilm where its treated and then treated water is separated. Gives the benefits of biofilms and membrane separation.

Front 13

biofilms in microbial fuel cells

Back 13

The fuel cell contains cathode and anode compartments. In anode compartment biofilm is present. The bacteria decompose the organic matter or waste (fuel) to produce protons and electrons. The protons are transferred through the proton exchange membrane to cathode compartment where it reacts with oxygen to produce water. Electricity is produced as electrons

Front 14

biofuels

Back 14

Fuel substitutes from renewable sources

Front 15

types of biofuels

Back 15

1. Bioalcohol (major form is bioethanol made in mass but is 30% lower energy density compared to gasoline and absorbs water so doesn't work in the current fuel infrastructure)
2. Biodiesel

Front 16

Butonal as biofuel

Back 16

biomass (sugar) is fermented to produce butanol which is then used as fuel