This document discusses using bacteria, specifically cyanobacteria, to produce biofuels. Cyanobacteria can be grown in photobioreactors using sunlight, water, and CO2 to produce fatty acids. An enzyme is added to cyanobacteria to increase fatty acid production. The fatty acids can then be extracted and converted into biodiesel. While cyanobacteria are a sustainable biofuel source, challenges remain in scaling up production and addressing costs. Overall, this technique teaches us about bacteria manipulation and molecular biology.

1. Biofuels using
Bacteria
By: Giovanna Panepinto

2. What is a Biofuel?
A biofuel is a fuel made from a renewable
energy source that is also environmentally
“friendly”

3. It all starts from nature.
 Fungiand bacteria sourced from extreme
environments are often most suitable.
 High pH
 Low or high temperature

4. Organism Development
 Typical process shown on the
right.
 Combine nature’s diversity with
biotechnology evolution
concepts to produce libraries of
organisms which will produce
the chemicals needed for the
process
 New biochemicals can result
from screening of millions of
variants of organisms

5. Cyanobacteria as a Production
Organism
 Approximately 40 variants of CYB have all of their
genome characterized.
 The variants with different production characteristics
 Sunlight drives the reactions within these cells.
 Enzyme (thioesterase) addition can help increase
production
 Some species and strains can produce 60,000 – 100,000
liters per hectare of algae biomass
 40% of this biomass can be oil
 Oil (long chain fatty acids) can be converted to diesel
fuel
Reference: Arizona State University

6. How Biofuels are made with
Cyanobacteria
 Cyanobacteria are first produced in a photobioreactor
which optimizes their growth
 An enzyme is given to the cyanobacteria which
modifies its fatty acid production and helps it produce
large amounts of those fatty acids
 It then secretes those acids which can be used to make
a sustainable biofuel (layers of the cell envelope can
also be genetically removed to speed up the secretion
process)

7. ASU Cyanobacteria Video
 Click the link!
http://www.youtube.com/watch?v=rSJS_ay
ietc

8. A “cyanobacteria” bioreactor

9. 9
Chemical Processing – Separation
of Oil from Cells
 Mechanical press
 Hexane extraction
 Supercritical CO2
 Sonication

10. Advantages
 Cyanobacteria are photosynthetic so
they only need to be grown with a few
components: water, sunlight, and CO2
 Cyanobacteria are easily produced in
high quantities
 They produce eco-friendly, sustainable
energy

11. By-product uses & Sustainability
 Aquaculture feeds
 Cells are still high in
protein, carbohydrates, micronutrients and
phytochemicals
 Feeding of Ornamental fishes
 Sources of beta-
carotene, astaxanthin, canthaxanthin, and other
carotenoids

12. Disadvantages
 Regional sustainability- the supply of
enzymes for the bacteria can be hard to
come by which makes it costly
 Availability of engineering resources as
well as materials to build photobioreactors
are expensive.
 Availability of space.

13. 13
Production Problems
 Contamination of the
bioreactor with non-target
bacteria.
 Introduction of grazers –
microbes that consume
produced oil
 Self shading and limiting of
nutrients (similar to the
process of lake turnover)

14. What This Technique Teaches
Us
 Our knowledge of bacteria’s uses as well
as our ability to manipulate bacteria is
increased
 By working with bacteria we learn its
molecular biology which allows us to
further understand how bacteria lives