Metabolic engineering of xylose-fermenting saccharomyces cerevisiae for bioisoprene production

Yavuz, Mustafa

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https://hdl.handle.net/2142/105631 Copy

Description

Title

Metabolic engineering of xylose-fermenting saccharomyces cerevisiae for bioisoprene production

Author(s)

Yavuz, Mustafa

Issue Date

2019-07-11

Director of Research (if dissertation) or Advisor (if thesis)

Jin, Yong-su

Department of Study

Food Science & Human Nutrition

Discipline

Food Science & Human Nutrition

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

bioisoprene, metabolic engineering, xylose, GC-FID

Abstract

With rising demand for tire production all over the world, natural rubber supply has not been adequate for tire industry. There are, however, multiple solutions proposed so as to overcome the existing rubber shortages. Of these solutions, synthetic rubber production has become wide-spread application. In order to produce synthetic rubber, it is incumbent on obtaining isoprene -monomer of synthetic rubber. Building block of synthetic rubber, isoprene can be produced by three different ways including chemical and petrochemical production. Apart from the methods of isoprene production abovementioned, biological synthesis of isoprene has been carried out by metabolic engineering that is environmentally-being application of commodity chemical production. Concerning the CO2 release for isoprene production, through petrochemical production methods, lured scientist into ruminating over bioisoprene feasibility. Bioisoprene production compared to other isoprene production methods were evaluated in terms of green metrics; and the only feasible way to produce bioisoprene is to use cheaper monosaccharides available for industrial microorganisms. Taken together, cheap carbon source-derived bioisoprene production is unmet demand for the sake of feasibility of bioisoprene production. Utilizing lignocellulosic sugar, xylose, is a nascent approach for bioproduction of commodity chemicals. Since xylose, the second most abundant sugar after glucose, can be assimilated by microorganism as a cheap carbon source to make ethanol and other chemicals, bioisoprene production out of xylose is not far-fetched. In this thesis, bioisoprene production from xylose were investigated to mitigate the pressure for increasing rubber demand in the world. To achieve this goal, xylose-consuming CT2-Quadraople Mutant (QM) Saccharomyces cerevisiae became a platform strain for isoprene production; and four different plasmids harboring isoprene synthase gene with strong promoter were constructed to introduce multi-copy isoprene synthase gene into CT2-QM genome. Every plasmid was digested with a specific restriction enzyme to provide homologous arms to yeast genome, resulting in integration of isoprene synthase into genome via homologous recombination. In doing so, multi-copy isoprene synthase gene harboring xylose-utilizing yeast strain were created; and tested their performances in the fermentation for bioisoprene production.

Graduation Semester

2019-08

Type of Resource

text

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http://hdl.handle.net/2142/105631

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Copyright 2019 Mustafa Yavuz

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