Single cell oil
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LOGO Single Cell Oils 1
Transcript of Single cell oil
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LOGO
Single Cell OilsSingle Cell Oils
Contents
Introduction1
Production of Single Cell Oils2
Single Cell Oils as nutraceuticals3
Algae for Biofuels4
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Safety of Single Cell Oils2
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SCOs production from low-cost substrates
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Introduction
Trichosporon
pullulansP
aul Lindner
reviewW
oodbine
Oil of Javanicus
GLA
-SC
O
Genetic m
odification
biofuels
1922 1959 1985 2015
Commercial production
small-scale process
world-wide development
R & D
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Introduction
The lipids produced by living organisms:
Membrane structure lipids Energy reserve lipids (TAGs)
The oleaginous Lipids accumulation more than 20% of their (biomass DW) TAG storage occurs at: The end of the exponential growth stage In periods of metabolic stress
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Introduction
BACTERIA
Molds&
Yeasts
Algae
SCO
• Quite different lipid !!• Low speed of grow !!• Complex liquid !!
• They produce lipids rich in PUFAs !!
• TAGs are 90% of their storage of lipids !!
• They are typically photosyn-thetic !!
• Lipids are complex !!
Oleaginous yeasts
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• TAGs
90%
Over 600 species of yeast have been identified, only about 30–40 can accumulate oil in their cells.
Oleaginous yeasts mainly accumulate TAGs , which account for 90% of their storage of lipids.
Some other neutral lipids: free fatty acids, monoglycerides, diglycerides, steryl-esters, sterol and polar fractions
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Oleaginous yeasts
Oil contents and fatty acid profiles of various oleaginous yeasts
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Oleaginous yeasts
Oil contents and fatty acid profiles of various fungi
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Production of microbial oils
SCOMicrobial oils destined for human consumption have been given the more marketable name of
Occurrence :
Surfeit of carbon (usually glucose)
Deprivation of essential nutrient
(nitrogen is the most frequently
used)
Growth mediumGrowth medium
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Production of microbial oils
Idealized representation of the process of lipid accumulation in an oleaginous microorganism
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Production of microbial oils
The nitrogen is essential for the biosynthesis of proteins and nucleic acids
The cells, however, continue to assimilate the available glucose, convert it into fatty acids and thence into the triacylglycerols
lipid accumulates, because other anabolic processes in the cell cease
TAGs are stored in the form of droplets of oil
Without changing osmolarity
Hydrophobic
nature
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Production of microbial oils
What mechanism is controlling the upper limit of oil accumulation
Answer: The provision of reducing power
The ability of a cell to accumulate oil is controlled by
The ability of the cell to produce sufficient NADPH
CH3CO- –CH2CH2- fatty acid
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Production of microbial oils
lipid accumulati
on processes
de nove
ex nove
“de novo” lipid accumulation processes
The process is carried out on hydrophilic materials and usually requires nitrogen-limited culture conditions.
Glucose was the most commonly employed carbon source
Many other substrates: pectin, starch, lactose, xylose, fructose, saccharose, radish brine, cassava starch, acetate, glucose enriched with organic acid, glucose, glucose enriched with tomato waste hydrolysate.
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Production of microbial oils
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Production of microbial oils
SCO production
Limiting nutriments (especially nitrogen)
The carbon source
pH
Oleaginous microorganisms
Temperature
Cultivation modes
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Production of microbial oils
Cultivation modes:
The fed-batch mode cultivation
proved to be effective in increasing
both the cell density and cellular lipids
of oleaginous microorganisms .
Modes
Batch
Repeated batch
Fed batch
Continuous
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Production of microbial oils
lipid accumulati
on processes
de nove
ex nove
“ex novo” lipid accumulation processes
The process is production of SCO through fermentation on hydrophobic materials.
Many hydrophilic substrates :fatty acids of animal or vegetable oils, pure fatty acids, fattyacid by-products or wastes, n-alkanes or volatile fatty acids
ex novo lipid production occurs simultaneously with cell growth
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Production of microbial oils
The synthesis of ex novo lipids was usually obtained with a mixture of hydrophilic substrates (e.g. glucose) and various fatty materials.
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Single Cell Oils as nutraceuticals
Oleaginous yeasts & fungi lipids >>>> rarely found in the plant or animal kingdom.
PUFAs are used for the biosynthesis of :
eicosanoids, leukotrienes, prostaglandins and resolvins. Certain PUFAs can improve the development of eye function and
memory in newly born infants and adults. Involvement of PUFAs in : Alzheimer’s disease, chronic bowel
disorder and some cancers.
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Single Cell Oils as nutraceuticals
GLA
ARA
DHA
EPA
Fish, especially the oily fish, such as mackerel, trout, salmon
Fish may contain undesirably high amounts of dioxins, heavy metals and other potentially toxic materials that have been ingested by the fish from the environment.
Their sale as nutraceuticals Infant formulas Acceptable commodities for vegans and various religious
groups
Capsule containing EPA and DHA
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Photosynthetically-grown microalgae
Closed systems which CO2-enriched air is introduced
• lipid contents: 36% or higher
Outdoors-grown, without CO2 addition
• Lipid contents: rarely exceed 10% of the biomass
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Photosynthetically-grown microalgae
Closed systems:
Usually tubular bioreactors The cost of running photobioreactors is extremely expensive
Astaxantin, is produced commercially
using this technology.
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Photosynthetically-grown microalgae
Outdoors-grown:
Large outdoor lagoons and ponds Lipid accumulation requires a surfeit of carbon to be available to the cells;
Using forced addition of CO2
Considerable danger of contamination
Safety
The lipids are complex
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Photosynthetically-grown microalgae
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Algae for Biofuels
Potential environmental benefits Greenhouse gas mitigation Bioremediation of wastewater
optim
al
cond
ition
s
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Algae for Biofuels
Cell Harvesting
Oil Extraction
Converting to biofuels
Mixing>>>to make sure algae are evenly exposed to light and nutrients
Typically operation>>> continuous mode
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Algae for Biofuels
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Algae for Biofuels
Graphical Representation 0
500
1000
1500
2000
2500
Gallons of Fuel Per Acre Per Year
Algae Palm Sugar Cane Corn Soy
Approximate yields for other fuel sources are far lower
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Algae for Biofuels
Harvesting and processing algae: Flocculation, Aggregates the algal cells
Gravity sedimentation Time consuming It requires space for settling ponds or tanks
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Algae for Biofuels
Oil extraction methods
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Algae for Biofuels
Conversion of algal oils to biodiesel fuel
Algal oil + Alcohols (in the presence of a base catalyst)
Glycerol + Biodiesel (fatty acid methyl or ethyl ester)
This reaction targets triacylglycerols; specifically the three fatty acid chains attached to a glycerol backbone
transesterfication
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Algae for Biofuels
Biodiesel yield from transesterfication is more than 90% and the biodiesel quality is comparable to conventional petroleum diesel
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SCOs production from low-cost substrates
Single cell oil production on hydrophilic materials
1. Molasses
Although oleaginous microorganisms can grow well on molasses medium due to its high sugar content, the high nitrogen content prevents its lipid accumulation.
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SCOs production from low-cost substrates
2. Raw materials from the food industry
Cornstarch hydrolysate (Zhu et al., 2003) Tomato waste hydrolysate (Fakas et al., 2008) Sweet sorghum extracts (Economou et al., 2011) Banana juice (Vega et al., 1988)
N-acetylglucosamine hydrolysate (Wu et al., 2011; Zhang et al., 2011) The major carbohydrate of the hydrolysate of shrimp processing waste
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SCOs production from low-cost substrates
3. Wastewaters Many sugar (polysaccharides)-based materials have been present in these
substances
4. Glycerol Microbial fermentation or chemical synthesis It can also be recovered from soap manufacturing During the biodiesel production process, glycerol is the primary by-
product
Glycerol was also used as a substance for producing SCO,
especially during DHA production, by some oleaginous alga such as Schizochytrium limacinum (Chi et al., 2007; Ethier et al., 2011; Pyle et al., 2008)
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SCOs production from low-cost substrates
5. Whey It is a by-product of cheese production Its great availability especially in Europe and the United States More recently, Mortierella isabellina had an outstanding performance in
biomass, fat and γ-linolenic acid production on cheese whey (Vamvakaki et al., 2010).
Single cell oil production on hydrophobic materials Industrial fats (Papanikolaou and Aggelis, 2003; Papanikolaou et al., 2001)
Vegetable oils (Aggelis and Sourdis, 1997)
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Safety
Microbial oils are a relatively recent>>>marketed in 1985
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Safety
Tremendous pressure was placed on the company producing the oil
Any possible toxicity
The initial toxicological
All trials were completely successful
sale in the UK
1990: It was clear that the oil posed no danger in consumption
The production organism itself having already being given GRAS status
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Safety
This should have no history of producing toxic metabolites or be capable of infecting animals or damaging the environment
The organism itself should not produce allergic reactions
All current SCOs are considered by the FDA to be ‘highly refined Oils’ that are not associated with allergic reactions (Ryan et al., 2010)
The oil is just an oil: It has been extracted, refined and de-odorized
It is important to evaluate the production organism itself
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Safety
The quantity of oil that is likely to be consumed by a person
7.3 g DHASCO per day
For two decades!!
No substantiated report has been provided to indicate that there has been
any problem with their consumption The component fatty acyl groups within the oil :
safe history of consumption
DPA: this fatty acid was also a component of human brain lipid
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Summary
Safety
SCOs
Unique and valuablesources
de novo
ex novo
low-cost substrates
as nutraceuticals
Biofuels
Production of microbial oils
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References
Selected References:
Awasthi P., Shrivastava S., Kharkwal A., Varma A. (2015), “Biofuel from agricultural waste: A review”,Int.J.Curr.Microbiol.App.Sci (2015) 4(1): 470-477.
Cohen Z., Ratledge C. (2010), “Single Cell Oils: Microbial and Algal Oils, Second Edition”,
AOCS Press, 3-29, 151-179. Donot F., Fontana A., Baccou J.C., Strub C., Schorr-Galindo S. (2014), “Single cell oils
(SCOs) from oleaginous yeasts and moulds: Production and genetics”, biomass and bioenergy 68 (2014) 135-150.
Huang C., Chen X., Xiong L., Chen X., Chen Y. (2013), “Single cell oil production from
low-cost substrates: The possibility and potential of its industrialization”, Biotechnology Advances 31 (2013) 129–139.
McNeil B., Archer D., Giavasis I., Harvey L. (2013),“Microbial production of food
ingredients, enzymes and nutraceuticals, Second Edition”, Woodhead Publishing Series in Food Science, Technology and Nutrition, 531-558.
Papanikolaou S., Aggelis G., (2011), “Lipids of oleaginous yeasts. Part I: Biochemistry of
single cell oil production: Review Article”, Eur. J. Lipid Sci. Technol. 2011, 113, 1031–1051.
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