BIOMATERIALS - Bioengineering for Pollution Prevention - page 46

environmental benefits of PLA, currently accounting for 10-15 percent of production, and of
biodegradable polymers made from nonrenewable resources, accounting for approximately 10
percent of production, seem to be smaller than starch-based thermoplastics, but still greater
than conventional polymers. For microbial polyesters, which currently make up a very small
part of total green plastics production, the environmental advantage seems to be small (or
perhaps nonexistent), but the fermentation technologies for producing them are among the
most recently developed, and both the production method and the scale of production can
influence evaluations of the overall environmental balance [20]. Additionally, the prospect of
producing these plastics in transgenic plants completely alters the environmental
consequences of production, thereby opening up improved life-cycle possibilities [12, 21].
Given the inherent problems associated with persistent plastics in the environment-
increasing pressure on landfill space, concerns over climate change, and the economic reality
that biobased plastics are already competing in the market without subsidies-applying the
tools of industrial biotechnology to the production of environmentally benign plastics is a
particularly vibrant area of scientific and commercial activity.
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[5] Stevens, E. S. (2002 ). Green plastics: An Introduction to the New Science of
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[7] Harper, C. A. (2000). Modern Plastics Handbook. McGraw-Hill Professional, New
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[8] Strong, A. B. (1999). Plastics: Materials and Processing , 2nd Edition. Prentice Hall,
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[9] Gerngross, T. U., and S.C. Slater (2003). Biopolymers and the environment , Science
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[10] Doi, Y. (2004). In Life Cycle Assessment of Microbial Polyesters, BioEnvironmental
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[11] Skraly, F. (2002). Bioplastics, in Encyclopedia of Environmental Microbiology . John
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[12] Snell, K. D., and O.P. Peoples (2002). Polyhydroxyalkanoate polymers and their
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