Use of Biodiesel Waste Glycerol in the Bacterial Production of
Polyhydroxyalkanoate (PHA) Biodegradable Plastic
Daniel Nicholson Graduate Student, Department of Paper &
Bioprocess Engineering
ESF Biodiesel Production Program
The current US biodiesel production capacity is nearing 1 billion gal per year. The co-product stream of waste glycerol could surpass 100 million gal per year
in the near future, and many possible uses for this essentially free raw material are under investigation.
Biodiesel is produced on the SUNY ESF campusfrom waste fryer oil from SU food services, for use in college vehicles and equipment .
O
O
O
OO
O
CH2
CH
CH2
O
OCH33
Triglyceride
Transesterification90% Biodiesel
Fatty acid methyl ester10%
Glycerol
+
Polyhydroxyalkanoate (PHA) Chemistry
HC
H2C C O
HC
H2C C O
CH3
O O
CH2CH3
HC
H2C C O
O
Rm n
hydroxybutyrate (HB) hydroxyvalerate (HV)
R = CH3: Hydroxybutyrate (HB)R = CH2CH3: Hydroxyvalerate (HV)R = 3-6 Carbon side chain: Medium chain length (mcl) PHAs with more elastomeric properties.
Increased side chain (R) length imparts flexibility to the polymer.
Microbiologically produced poly-3-hydroxyalkanoate (PHA) polymers are a well known biodegradable material with physical characteristics comparable to some commercially
available plastics like polypropylene and polyethylene.
PHA Biodegradability
Biodegradability studies have shown that many bacteria and fungi excrete PHA degrading enzymes in soil, sludge, fresh and sea water. These enzymes hydrolyze solid PHA into water-soluble oligomers and monomers, and use the resulting products as nutrients within their cells.
Jendrossek, D. 2001. Adv. Biochem Eng Biotechnol. 71. 294-325
Weeks in sewage sludge 0 2 4 6 8
Bacterial PHA Production
Consumes a number of foods, and stores extra in granules.
Benchtop bioreactors can be used to carefully control growth, and to observe product formation and food
consumption.
Burkholderia cepacia is a bacteria common in soil and water. This organism is being used in research at
SUNY ESF, and has been shown to produce PHAsfrom different food sources.
PHA is the material stored toconserve energy and Carbon for
future use.
Biotechnology @ ESF
•Current projects•Metabolic and protein engineering for the production of biodegradable plastics•Microbial biodiesel production•Engineering of cellulase enzymes
•Looking for graduate student applicants with strong backgrounds in:•Biochemistry•Molecular Biology•Microbiology•Synthetic organic chemistry
For more information you can email Dr. [email protected]
Lab webpage: http://www.esf.edu/chemistry/nomura/lab/