Properties of Nicotiana glauca as a biorefining feedstock

Amanda Kozlo

Research output: ThesisDoctoral Thesis

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Abstract

Increasing issues of climate change and land availability/allocation for food and feed
have been pressurising world societies to advance environmental sustainability. Because
of that, the biorefining concept evolved to replace petro–based industries, while the
sustainability focuses on the society, economy and the environmental issues raised as part
of the renewable energy policies. Plant–fuelled biorefinery have potential to becoming a
great alternative to fossil fuels, however the competition with the food market is straining
the supply of food and its prices, therefore needs to be addressed immediately.
Nicotiana glauca, otherwise called Tree tobacco is a potential source for biorefinery that
does not compete with the food market unlike other plant based sources currently used.
A globally naturalised South American shrub, it is a fast growing and well habituated
shrub in dry and arid areas in countries such as USA, Australia, Asian and most southern
European countries yet is still comparable to the traditional crops used for biorefinery. A
large above–ground biomass shrub featuring sticky and rubbery pale surface and thick
leaves with grey appearance is a self fertile, amenable to genetic manipulation and fast
growing plant. In the present study it was evaluated for its potential to become integrated
into current renewable source economy as a feedstock to replace petro–chemical refinery.
System biology tools were utilised encompassing non–polar, polar and isoprenoid metabolite
analysis to assess the changes of the metabolite profile over leaf development as well
as to identify the levels of high–value compounds naturally occurring in Nicotiana glauca.
The leaves were found to contain a simple metabolite profile rich in fatty acids (35% of
total non–polar dry leaf material), carotenoids and other high value compounds including
easily extractable leaf surface containing high amounts of pure long chain hydrocarbons
(C29– C33, at 96%). A number of compounds have been identified to be potentially used
to produce for e.g. bioplastics, organic solvents and biodiesel. The study also evaluated
the metabolite profile of a ketocarotenoid engineered line containing crt hydroxylase
and ketolase genes. The evaluation of increasing value through the occurring metabolite
changes showed the patterns underlying a plausible connection between the fatty
acid and carotenoid biosynthetic pathways in the crop. As a result, the thesis covered
industrial application of the crop and characterised biochemical roles between the two
pathways.
Original languageEnglish
QualificationPh.D.
Awarding Institution
  • Royal Holloway, University of London
Supervisors/Advisors
  • Fraser, Paul, Supervisor
  • Bramley, Peter, Advisor
Thesis sponsors
Award date1 Mar 2018
Publisher
Publication statusUnpublished - 2017

Keywords

  • Nicotiana glauca
  • Ketocarotenoids
  • Lipids
  • Lipid Metabolism
  • crtz/w
  • feedstock
  • Biorefining
  • Metabolic profiling
  • Amanda Kozlo
  • Kozlo
  • PhD

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