Adipic acid production from lignin derived aromatics by Acinetobacter baylyi ADP1
Sohkanen, Sara (2023)
Sohkanen, Sara
2023
Biotekniikan DI-ohjelma - Master's Programme in Bioengineering
Lääketieteen ja terveysteknologian tiedekunta - Faculty of Medicine and Health Technology
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Hyväksymispäivämäärä
2023-05-09
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tuni-202304244210
https://urn.fi/URN:NBN:fi:tuni-202304244210
Tiivistelmä
Climate change and fossil-oil depletion alongside other environmental concerns of fossil use provide an increasing demand for more sustainable alternatives. Biological production of valuable chemicals from renewable and abundant raw materials could solve most of the current issues of for example petrochemically produced chemicals such as the nylon-6,6 precursor adipic acid. Utilizing lignin which is a renewable and abundant side-stream of existing industry, we could simultaneously produce sustainable bioplastic and increase the profitability of pulping and biofuel industries.
In this thesis, Acinetobacter baylyi ADP1 was evaluated as a potential host organism for metabolic engineering in order to establish bioproduction of adipic acid from lignin derived aromatics. The state of studies up to date concerning adipic acid bioproduction as well as use of ADP1 for production of other valuable chemicals, such as wax esters, were also reviewed. ADP1 is an attractive candidate for metabolic engineering due to its excellent transformation and recombination efficiency as well as diverse substrate range and native metabolism. Its native aromatics degradation pathways make it an interesting subject of studying lignin utilization as raw material for microbial chemical production.
Previous work using P. putida, which is a very similar organism to ADP1, has demonstrated the possibility to utilize the native β-ketoadipate pathway and synthetic biosynthesis pathway inspired by reverse-β-oxidation for adipic acid production from lignin. In addition, muconic acid bioproduction has been a topic of interest for chemical or more recently biological conversion to adipic acid. This process is often referred to as the two-step process as opposed to direct biosynthesis of adipic acid. More work is required to reach an industrially and economically feasible process. However, bioproduction of different chemicals has great potential to replace many of the current petrochemical processes in the future while also providing more sustainable, climate and environmentally friendly alternatives.
In this thesis, Acinetobacter baylyi ADP1 was evaluated as a potential host organism for metabolic engineering in order to establish bioproduction of adipic acid from lignin derived aromatics. The state of studies up to date concerning adipic acid bioproduction as well as use of ADP1 for production of other valuable chemicals, such as wax esters, were also reviewed. ADP1 is an attractive candidate for metabolic engineering due to its excellent transformation and recombination efficiency as well as diverse substrate range and native metabolism. Its native aromatics degradation pathways make it an interesting subject of studying lignin utilization as raw material for microbial chemical production.
Previous work using P. putida, which is a very similar organism to ADP1, has demonstrated the possibility to utilize the native β-ketoadipate pathway and synthetic biosynthesis pathway inspired by reverse-β-oxidation for adipic acid production from lignin. In addition, muconic acid bioproduction has been a topic of interest for chemical or more recently biological conversion to adipic acid. This process is often referred to as the two-step process as opposed to direct biosynthesis of adipic acid. More work is required to reach an industrially and economically feasible process. However, bioproduction of different chemicals has great potential to replace many of the current petrochemical processes in the future while also providing more sustainable, climate and environmentally friendly alternatives.