Welcome to the 31st IUBS General Assembly and Conference on ...

Clostridum sp. models. More than 50 reactions were
involved in glycolysis, pen<strong>to</strong>se phosphate pathway,
incomplete citric acid cycle (TCA), pyruvate metabolism,
anaplerotic reaction, hydrogenase, transport process, ATP
maintenance <strong>and</strong> biomass formation. The flux
distributions under 2 substrates (glucose <strong>and</strong> glycerol)
<strong>and</strong> coculture conditions (with E. coli) were estimated by
Metabolic Flux Analysis (MFA). The experimental data was
utilized as constraints <strong>and</strong> <strong>the</strong> maximal biomass
formation was selected as <strong>the</strong> objective function.
Experimental errors of external fluxes were considered in
<strong>the</strong> MFA. The dominant pathways <strong>and</strong> key nodes were
identified. It was also suggested that <strong>the</strong> glucose was
mainly consumed by C. butyricum when it was
co‐cultivated with E. coli.
Microalgal biofuels: progress <strong>and</strong>
opportunities
José A OLIVARES
NAABB, Los Alamos National Labora<strong>to</strong>ry. Email:
olivares@lanl.gov
The National Alliance for Advanced Biofuels <strong>and</strong>
Bioproducts (NAABB) is a consortium of 40 institutions
developed <strong>to</strong> capture <strong>and</strong> integrate intellectual property,
expertise, equipment, <strong>and</strong> facilities from a diverse set of
companies, universities <strong>and</strong> national labora<strong>to</strong>ries in order
<strong>to</strong> develop a systems approach <strong>to</strong> innovation for
sustainable commercialization of biofuels <strong>and</strong> coproducts.
The formation of this alliance brings <strong>to</strong>ge<strong>the</strong>r multiple
institutions with breadth <strong>and</strong> depth of knowledge in
biofuels research. It creates a dynamic network for <strong>the</strong>
flow of ideas from <strong>the</strong> bench <strong>to</strong> <strong>the</strong> marketplace quickly
<strong>and</strong> with constructive iteration so that research <strong>and</strong>
innovation can be tailored appropriately <strong>to</strong>wards
successful commercialization. The NAABB Algal Biofuels
Consortium was formed <strong>to</strong> address key barriers across
<strong>the</strong> full value chain of algal biofuels production. As such, it
is an integrated program developing <strong>to</strong>ols that facilitate
deployment through <strong>the</strong> S&T. The NAABB is bringing
innovation across <strong>the</strong> technology development platforms
with core economics <strong>and</strong> sustainability goals bringing a
cohesive picture <strong>to</strong> all efforts. Several key technical
challenges are being addressed by <strong>the</strong> NAABB Algal
Biofuels Consortium including: 1)algal strains that can be
cultivated in real‐world conditions <strong>and</strong> harvested with
minimal energy; 2)technologies that are scalable <strong>and</strong>
provide <strong>the</strong> energy return on investment; 3) technology
integration with needed nutrient, water, <strong>and</strong> o<strong>the</strong>r
recycles; <strong>and</strong> 4) sustainable technologies with respect <strong>to</strong>
environment, cost <strong>and</strong> permitting. An overview of <strong>the</strong>
consortium’s vision, goals, progress <strong>and</strong> status is
provided in this presentation.
Microbial lipids production by oleaginous
yeasts
Zongbao ZHAO
Dalian Institute of Chemical Physics, CAS, 457 Zhongshan
Road, Dalian 116023, China. Email: zhaozb@dicp.ac.cn
Biodiesel is an excellent renewable energy carrier.
However, large‐scale biodiesel production remains
challenge because of limited supply of oil plant‐based
feeds<strong>to</strong>cks. On <strong>the</strong> o<strong>the</strong>r h<strong>and</strong>, carbohydrates from
lignocellulosic biomass are <strong>the</strong> most abundant
renewable resources. Some microorganisms can
accumulate lipid <strong>to</strong> more than 20 wt% of <strong>the</strong>ir cell mass.
Microbial lipid consists mainly of triacylglycerols with
fatty acid compositional profile similar <strong>to</strong> those of
vegetable oils. Because it can be obtained from
renewable raw materials, <strong>and</strong> be produced continuously
with no extensive arable l<strong>and</strong> requirement, microbial
lipid has been considered as potential feeds<strong>to</strong>ck for
biodiesel industry.
During <strong>the</strong> past few years, we have been working on
microbial lipids production by oleaginous yeasts. We
identified a h<strong>and</strong> of outst<strong>and</strong>ing oleaginous yeasts,
including Rhodosporidium <strong>to</strong>ruloides, Lipomyces starkeyi,
Cryp<strong>to</strong>coccus curvatus <strong>and</strong> Trichosporon cutaneum.
These yeasts use materials, including glucose, xylose,
raw glycerol <strong>and</strong> corn stalk hydrolysates, as carbon
sources. In particular, we demonstrated that T. cutaneum
AS 2.571 could assimilate glucose <strong>and</strong> xylose
simultaneously, <strong>and</strong> accumulated intracellular lipid up <strong>to</strong>
59 wt% with a lipid coefficient up <strong>to</strong> 0.18 g/g sugar. We
optimized lipid production processes. When using <strong>the</strong>
yeast R. <strong>to</strong>ruloides as <strong>the</strong> lipid producer in a 15L
bioreac<strong>to</strong>r, we achieved lipid content, production titer
<strong>and</strong> lipid productivity of over 65 wt%, 100 g/L <strong>and</strong> 1.0
g/L/h, respectively. We showed that inhibi<strong>to</strong>ry
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