Utilization of cellulosic vinasse with Acinetobacter baylyi ADP1
Laaksonen, Ilmari (2022)
Laaksonen, Ilmari
2022
Master's Programme in Environmental Engineering
Tekniikan ja luonnontieteiden tiedekunta - Faculty of Engineering and Natural Sciences
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Hyväksymispäivämäärä
2022-02-21
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tuni-202201311751
https://urn.fi/URN:NBN:fi:tuni-202201311751
Tiivistelmä
Ethanol is industrially produced through a fermentation reaction where different feedstocks are used to provide sugars for the yeast cells to ferment into ethanol. The fermentation product is then distilled and sieved, separating the product into ethanol and stillage factions. The stillage, which is also known as the vinasse contains everything in the fermentation product other than most of the ethanol and the live yeast cells. As the production of ethanol and thus vinasse increases annually, new methods to utilize the vinasse besides using it as a fertilizer have become a necessity. Cellulosic vinasse produced from cellulosic feedstocks is especially dangerous for soils, as it contains both aromatic and organic acid compounds that are toxic to most organisms. By utilizing the new trend of bioprocessing, these compounds can be converted into more valuable products through microbial metabolic pathways.
In this study it is demonstrated that A. baylyi ADP1 can grow in diluted cellulosic vinasses and be able to deplete most of them from the medium. It was also discovered that A. baylyi ADP1 cells consumed glycerol even though neither the synthetic nor real vinasse contained gluconate. A gene knockout of ACIAD2924 transcribing an acidic transcription factor A (atfA) was found to increase the cell volumes of A. baylyi ADP1 by 87% for 24 hours but returning to normal dimensions afterwards. This increase of cell volumes effect on wax ester was investigated in this study while also demonstrating that the lack of atfA possibly affects parts of the lipid synthesis pathways of A. baylyi ADP1. The ΔatfA strain was shown to synthesise wax esters in the real vinasse, but not in mediums with glucose as the sole carbon source. Wild-type cells were on the other hand able to synthesise wax esters in pure glucose cultures, but not in vinasse cultures. Discoveries in this study promote further studies into increasing the cell viability of the A. baylyi ΔatfA to increase the duration of the cell volume increase and investigating the effect of the atfA protein on the lipid synthesis pathway.
In this study it is demonstrated that A. baylyi ADP1 can grow in diluted cellulosic vinasses and be able to deplete most of them from the medium. It was also discovered that A. baylyi ADP1 cells consumed glycerol even though neither the synthetic nor real vinasse contained gluconate. A gene knockout of ACIAD2924 transcribing an acidic transcription factor A (atfA) was found to increase the cell volumes of A. baylyi ADP1 by 87% for 24 hours but returning to normal dimensions afterwards. This increase of cell volumes effect on wax ester was investigated in this study while also demonstrating that the lack of atfA possibly affects parts of the lipid synthesis pathways of A. baylyi ADP1. The ΔatfA strain was shown to synthesise wax esters in the real vinasse, but not in mediums with glucose as the sole carbon source. Wild-type cells were on the other hand able to synthesise wax esters in pure glucose cultures, but not in vinasse cultures. Discoveries in this study promote further studies into increasing the cell viability of the A. baylyi ΔatfA to increase the duration of the cell volume increase and investigating the effect of the atfA protein on the lipid synthesis pathway.