Process for the production of polyhydroxyalkanoates

Abstract

Embodiments of the invention relate generally to processes for the production and processing of polyhydroxyalkanoates (PHA) from carbon sources. In several embodiments, PHAs are produced at high efficiencies from carbon-containing gases through the utilization of a regenerative polymerization system.

Description

RELATED APPLICATIONS[0001]This application claims the benefit of Provisional Application Nos. 61 / 237,606, 61 / 237,609, 61 / 237,635, 61 / 237,603, 61 / 237,616, 61 / 237,615, 61 / 237,620, 61 / 237,643, 61 / 237,633, 61 / 237,630, 61 / 237,626, 61 / 237,642, 61 / 237,639, and 61 / 237,627, all filed on Aug. 27, 2009, the disclosures of which are all incorporated by reference herein.BACKGROUND[0002]1. Field of the Invention[0003]Embodiments of the invention relate to an improved process for the production and processing of polyhydroxyalkanoates, and specifically to a process for the production of polyhydroxyalkanoates from carbon-containing gases.[0004]2. Description of the Related Art[0005]Polyhydroxyalkanoates (PHAs) are thermoplastic polyesters that serve as energy storage vehicles in microorganisms. PHAs are biodegradable in both aerobic and anaerobic conditions, are biocompatible with mammalian tissues, and, as thermoplastics, can be used as alternatives to fossil fuel-based plastics such as polypropyle...

AI Technical Summary

Benefits of technology

[0093]In several embodiments, the density of the liquid in the light path is reduced by adding gas to said liquid in the light path. In some embodiments, the gas is air, oxygen, methane, carbon dioxide, nitrogen, and/or a combination thereof. In some embodiments, the gas is simultaneously added along with the light. In certain embodiments, the gas and the light are emitted or injected into the liquid through a common material, such as a permeable or semi-permeable membrane through which light and/or gas traverse. In other embodiments, the light and the gas are added separately. In such embodiments, customization of the addition is possible. For example, gas can be added in pulses (e.g., on/off sequences), continuously, or in bracketed time frames around the addition of light. In some embodiments, the addition of light and gas are coordinated to maximize the penetration of the light. For example a burst of gas followed by a burst of light (or overlapping to some degre...

Problems solved by technology

Unfortunately, despite these maximized efficiency advantages, sugar-based PHA production remains many times more expensive than fossil fuel-based plastics production.

Thus, given the apparent efficiency maximization of the high density sugar-derived PHA production process, PHAs are widely considered to be fundamentally unable to compete with fossil fuel-based plastics on energy, chemical, and cost efficiency.

Despite the environmental advantages of PHAs, the high cost of PHA production relative to the low cost of fossil fuel-based plastics production has significantly limited the industrial production and commercial adoption of PHAs.

Unfortunately, the fermentation of carbon-containing gases presents technical challenges and stoichiometric limitations that have, in the past, rendered the g...

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