PHA Copolymer Production Using Two-Stage Bacterial Cultivation
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Solution Overview
Problem
Existing methods for producing PHA-copolymers are not suitable for industrial scale processing and face challenges in extraction efficiency, particularly with longer chain copolymers, and require long reaction times.
Innovation Solution
A method involving heterotrophic and autotrophic cultivation of wild-type bacteria under controlled atmospheric conditions with specific precursors and pressures to produce PHA-copolymers, followed by extraction using polar organic solvents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If existing methods are used for producing PHA-copolymers, then production can be achieved, but the methods are not suitable for industrial scale processing and require long reaction times
Solution Approach 1:
The patent applies parameter changes by optimizing cultivation conditions including heterotrophic and autotrophic phases, controlling oxygen levels (0-10% in some embodiments), adjusting pH ranges (6.5-7.5), and selecting specific temperature ranges (20-45°C) to significantly reduce reaction time and improve production efficiency for industrial scaling
Solution Approach 2:
The patent implements preliminary action through a two-stage cultivation process where bacteria are first grown heterotrophically to build biomass, then switched to autotrophic conditions for PHA-copolymer production. This preparatory biomass accumulation phase enables faster and more efficient polymer production in the subsequent phase
2Quantity of substance
If existing extraction methods are used, then PHA can be extracted, but extraction efficiency is poor particularly with longer chain copolymers
Solution Approach 1:
The patent uses polar organic solvents as intermediaries to facilitate efficient extraction of PHA-copolymers from bacterial cells. The selected solvents act as mediators that effectively penetrate cell structures and dissolve the polymer, achieving high extraction efficiency even for longer chain copolymers that are difficult to extract with conventional methods
3Reliability
If wild type bacteria are used for production, then genetically modified organisms are avoided, but production efficiency and scalability are limited
Solution Approach 1:
The patent achieves industrial-scale suitability with wild type bacteria by optimizing cultivation parameters including alternating heterotrophic and autotrophic phases, controlling dissolved oxygen levels, adjusting nutrient composition, and selecting appropriate temperature and pH ranges, thereby enhancing productivity without genetic modification
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method enables efficient production and purification of PHA-copolymers with improved properties, allowing for a wider range of copolymers and reduced reaction times, suitable for industrial applications.
Implementation Method 1
extracting the produced PHA in an efficient way... extraction using polar organic solvents
Data Source
AI summary
The present invention discloses a method for producing PHA-copolymer using bacteria, by using a two-step process. In the first step the bacteria are grown under heterotrophic conditions using an organic substance as carbon source and exponential growth conditions. In a second step the bacteria are then cultivated under autotrophic conditions under an atmosphere of H2, CO2 and O2, wherein the O2 content is less than 10 % (v/v) and the pressure is more than 1 barg and at least one precursor for further monomers is added before and/or during this step, wherein the precursor is selected from an organic substance comprising at least 3 carbon atoms and at least 2 oxygen atoms, wherein the organic substance in its hydrolyzed form comprises at least two of carbon atoms, which are part of a functional group selected from COOH, C=O, C-OH. By this the production of PHA-copolymers with unique properties and at a high rate is possible.