Understanding methanotrophic polyhydroxybutyrate (PHB) production across scale : life cycle assessment, pure culture experimentation, and pathway/genome database development
Abstract/Contents
- Abstract
- While the 140 million tons of plastics produced each year may contribute to quality of life, they also come at a significant cost. Their production requires large quantities of nonrenewable resources, contributing to climate change; they accumulate in landfills and natural environments; and they often contain harmful additives. One way to address the multiplicity of problems that arise from the widespread use of synthetic plastics--without compromising convenience and disposability—would be to replace them with functionally equivalent materials that are biobased, biodegradable, and biocompatible, such as polyhydroxyalkanoates—a class of bioplastics. Bacteria known as "methanotrophs" consume methane as feedstock, and some produce the PHA polymer poly-ß-hydroxybutyrate (PHB). PHB production from methane could take advantage of the abundant biogas methane that is currently flared or allowed to escape to the atmosphere by the waste sector (landfills and wastewater treatment plants) to produce a valuable product that biodegrades to methane at end-of-life, creating a closed-loop cycle. This research evaluates methanotrophic growth and PHB production across scale. (1) Life Cycle Assessment (LCA) is used to anticipate the environmental impacts of PHB production from waste biogas by extrapolation from laboratory scale studies. LCA is used as an early-stage design tool to identify opportunities for pollution prevention, reduce resource consumption, guide environmental performance improvements, and identify research needs. The LCA also enables comparison with published LCAs for PHB produced from other feedstocks. (2) Stoichiometry and kinetics are evaluated and modeled for PHB-producing methanotrophs to describe the effects of oxygen and nitrogen on growth and PHB production by two PHB-producing methanotrophs. Significant differences were observed, with major implications for the use of these species in biotechnology applications. Such analyses can better inform bioreactor design, scale-up models, and life cycle assessments (LCAs). (3) A pathway genome database is developed for Methylosinus trichosporium OB3b as a model organism using pathway reconstruction to predict the metabolic composition. The database provides a platform for the visualization of experimental data from omics experiments, facilitates comparative studies of pathways across species, and provides a resource for biotechnology applications of methanotrophs, such as through flux balance analysis.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2012 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Rostkowski, Katherine Helen |
|---|---|
| Associated with | Stanford University, Civil & Environmental Engineering Department |
| Primary advisor | Criddle, Craig |
| Thesis advisor | Criddle, Craig |
| Thesis advisor | Karp, Peter D |
| Thesis advisor | Lepech, Michael |
| Thesis advisor | McCarty, Perry L |
| Advisor | Karp, Peter D |
| Advisor | Lepech, Michael |
| Advisor | McCarty, Perry L |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Katherine Helen Rostkowski. |
|---|---|
| Note | Submitted to the Department of Civil and Environmental Engineering. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2012. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2012 by Katherine Helen Rostkowski
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
Also listed in
Loading usage metrics...