Single-cell protein (SCP), specifically yeast, algae, fungi and bacteria, is being investigated as a solution to the global food problem. SCP shows promise as an alternative protein source for both human and animal consumption. Key benefits include its high protein content, ease and speed of production, and ability to use waste materials as a substrate. However, SCP also faces challenges such as potentially high nucleic acid content and production costs that must be addressed. Continued research is needed to optimize SCP nutritional profiles and develop products that are cost-competitive and similar to familiar foods.

1. SINGLE-CELL
PROTIEN
Being investigated as solution to world food
problem
Presented by
Mohamed Abdulazim
Supervisor
Prof. Eman Elmasry

2. Introduction
 The development of SCP was really the
beginning of biotechnology.
 Prior to this the industrial fermentation
was mainly focused on antibiotics and
other products which did not have to
compete.
 The development was brought up by
the oil companies rather than the food
companies.

3.  People in third world and developing countries are
suffering from menace of protein deficiency in their diets
resulting in serious protein malnutrition problems.
 The situation, accompanied with rapid population growth
demands exploration of new & un-conventional protein
sources to fortify human foods.
 Saccharomyces cerevisiae is very promising and cost
effective source of single cell protein due to its bigger size,
easy harvesting, lower amount of nucleic acids and good
blend of essential amino acids.
 Its protein quality & chemical score is comparable with
soybean or egg protein.
 The yeast is highly significant as an alternative source of
protein to cover the increasing demands due to rapidly
escalating population.

4.  Single Cell Protein (SCP) sources that can be derived from
algae, yeasts, fungi and bacteria can be used as food
supplements for animals or humans.
 Most targeted areas of SCP would apply towards animal
feed
 Single Cell Protein (SCPs) sources such as mycoproteins
can serve as food substitutes such as meat replacement
products similar to Tofu
 QuornTM similar to Tofu, is used as a flexible meat substitute
produce that has been marketed as products such as
chicken pieces, turkey and beef substitute products.
 Other products marketed also include fish fillets, deli meat
substitutes, pies and pastries and ready made meals.

5. Definition
 The term single cell protein (SCP) refers
to dead, dry cells of micro-organisms
such as yeast, bacteria, fungi and algae
which grow on different carbon sources.
 The name "single cell protein" was used
for the first time by the M.I.T. professor
Carol Wilson to give a better image than
"microbial protein.

6. SCP production
Process
 Following basic steps are involved in SCP
production process.
 PREPARATION of suitable medium with
suitable carbon source.
 CULTIVATION of suitable strain of micro
organism.
 PREVENTION of contaminations.
 SEPARATION of microbial biomass with or
without product.

8. Production of SCP
 Production of SCP
from hydrocarbons or
waste of petroleum
industry, from wood,
sewage, natural gas

9. SCP FROM WOOD :
 Cellulose from natural sources and waste wood
is an attractive starting material for SCP
production because of its abundance.
 The association of cellulose with lignin in wood
makes it intractable to microbial degradation
 Thermal or chemical pretreatment, used in
combination with enzymatic hydrolysis, is
usually required.
 Systems using cellulolytic organisms appear to
have promise, but economic viability has yet to
be Achieved

10. SCP FROM
CARBOHYDRATES :
 Whole milk whey or deproteinised whey is a
carbohydrate source, which creates disposal
problems.
 (High BOD) Problems associated with whey for
SCP production are usually insufficient substrate,
seasonal supply variations and its high water
content (>90%) which makes transport prohibitively
expensive.
 While most organisms do not grow on lactose as a
carbon source, strains of the yeast Kluyveromyces
marxianus readily grow on lactose.

11. SCP FROM NATURAL GAS :
 Methane was initially considered as a SCP raw
material because, as a gas product, purification
problems after fermentation would be minimal.
 Disadvantages associated with methane-based
processes are related to:
(a) The greater oxygen requirements necessary to
fully oxidize methane compared with paraffin's,
(b) The low solubility of methane in water and
(c) the requirement that the Fermentation plant
is flame proof as methane-oxygen mixtures are
highly explosive

12. Microorganisms Used :

13. Yeasts and Fungi
 Filamentous Fungi used for SCP
production are:
Chaetomium celluloliticum, Fusarium
graminearum, Paecilomyces varioti which
grows on cellulose waste, starch, and
sulphite waste liquor respectively and
content about 50 – 55 % protein
 SCP is produced from yeasts viz. Candida
utilis, Candida lipolytica, Saccharomyces
cervicea.

14.  Torula yeast (which grows on Ethanol) as a food is
obtained through fermentation using molasses as
substrate and it has high protein–carbohydrate
ratio than forages.
 It is rich in lysine but poor in methionine and
cysteine.
 Saccharomyces consists of high protein with good
balance of amino acids and rich in B–complex
vitamins.
 It is more suitable as poultry feed. Yeast are
higher in lysine content.
 Strict aseptic conditions are required when using
Yeast as a SCP production.

15. Disadvantages:
Disadvantages
1. High nucleic acid content.
2. Slow growth is observed in Fungi vis-
à-vis than yeast & bacteria.
3. Contamination risk.
4. Mycotoxins are also produced.

16. Bacteria
They have more than 80% protein but are poor
in sulphur containing amino acids.
Brevibacterium uses hydrocarbons while
Methylophilus methylitropous uses methanol
as a substrate.
Disadvantages:
 It has high nucleic acid content.
 Recovering the cells is a bit problematic.
 Endotoxin production should be carefully
tested.

17. Algae
 Chlorella, Scenedesmus acutus and Spirulina maxima are
grown for SCP.
 These have about 60% protein with good amino acid
composition but less in sulphur containing amino acids.
 Chlorella and Spirulina are used for commercial scale
production in Taiwan, Thailand, Japan, Israel, Mexico and
USA.
 It is spray dried and sold as pills and powders.
Disadvantages:
 As they are rich in Chlorophyll, it is not advised for human
consumption (except Spirulina).
 It has low density i.e. 1-2 gm dry weight/litre of substrate.
 There is lot of risk of contamination during growth.

18. Spirulina
 The United Nations Organization(UNO) in its
World Food Conference of 1974 declared
Spirulina as the best food for tomorrow.
 World Health Organization(WHO) has
hailed Spirulina the greatest super food on
the earth.
 Upon testing it NASA scientists found 1 kg of
Spirulina nutritionally
 equal to 1000 kgs of assorted vegetables

19. PRODUCTION COST
 The production cost strongly influenced by the nature of raw
starting material used.
 If starting material used is disposed of as a waste product ,
then the raw material cost is negative.
 However, if a useful material is used, then starting Material
used will play a major role in the final cost of SCP.
 Price of SCP varies depending on how it is used, i.e: SCP for
human is about 10 times more expensive than SCP for animal
feed because it is more highly refined.

20. Nutritional Value of SCP
For the assessment of the nutritional value of SCP, factors such as :nutrient
For the assessment of the nutritional value of SCP, factors such as :nutrient
composition, amino acid profile, vitamin and nucleic acid content.
Other nutritional parameters which evaluate the quality of a given SCP are:
 The digestibility (D)
 The biological value (BV)
 The protein efficiency ratio (PER)
 The net protein utilization

21. Uses of SCP
Single cell proteins have application
 in animal nutrition as:
fattening calves, poultry, pigs and fish
breading
 in the foodstuffs area as:
aroma carriers, vitamin carrier, emulsifying
aids and to improve the nutritive value of
baked products, in soups, in ready-to-
serve meals, in diet recipes and
 in the technical field as:
paper processing, leather processing and as
foam stabilizers.

22. Advantages of Production
 It has high protein and low fat content.
 It is good source of vitamins particularly B-complex. e.g. Yeasts
 It can be produced through-out the year.
 Waste materials are used as substrate for the production of these proteins.
It reduces the environmental pollution and helps in recycling of materials.
 SCP organisms grow faster and produce large quantities of SCP from
relatively small area of land and time.
 These have proteins with required amino acids that can be easilyselected by
genetic engineering.
 During the production of SCP biomass, some organisms produce useful by
products such as organic acids and fats.
 It can be genetically controlled.
 It causes less pollution.
 Algal culture can be done in space which is normally unused.

23. SCP's Evaluation and Future
Prospects
 SCP has a proven record as a source of protein which
may be obtained with large productivities in
compact installations .
 new view is that there is a market for products of
microbial origin, aimed at animal and direct human
consumption as substitutes for meat or even fish,
given the increasing depletion of fish stocks.
 Aside from this view, the problem of increasing
world population and limited food production may
not demand SCP production at this time, but
remains as a latent issue

24.  The continued research on the
production of microorganisms for animal
and human consumption will
undoubtedly find application in the
future.
 This research should also incorporate the
development of recombinant strains
from no conventional GRAS (Generally
Regarded as a Safe) yeasts and fungi .

25. For future success of SCP:
 First, food technology problems have
to be solved in order to make it
similar to familiar foods.
 Second, the production should
compare favorably with other
protein sources

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