This document discusses single cell protein (SCP), which refers to microbial cells or protein extracts that can be used as a protein supplement. SCP contains 60-80% protein as well as other nutrients. Various microbes such as algae, fungi and bacteria can be used to produce SCP. SCP production offers advantages such as low space requirements, ability to use waste materials, and independence from climate. Specific microbes discussed include Spirulina algae and methods of mass culturing, harvesting, drying and using Spirulina SCP. The document also outlines various microorganisms and substrates that can be used to produce SCP.

1. Submitted by;
k. Jayalakshmi
II m.sc biotechnology.

2. INTRODUCION
 Single cell protein (scp) refers to the microbial cells
or total protein extracted from pure microbial cell
culture (monoculture) which can be used as protein
supplement for human or animal.
 Dried biomass of a single species of microbe that can
be used as a protein source in the diet, is known as
single cell protein (SCP) .
 The dried biomass of some microorganisms is rich in
nutritionally valuable protein, vitamins and mineral
and it does not contain any toxic substances.

3.  It is used as a protein source in human died and
animals feed.
 For the first time, during world war I, in Germany
biomass of saccharomyces cerevisiae was produced in
large scales and consumed as a protein source.
 World war II, biomass of candida utilis was consumed
as SCP.
 Since then many microbe have been invented for their
nutritive value and consumed as a protein source.

4. SINGLE CELL PROTEIN
 Single cell protein broadly refers to the microbial or
protein extract used as food or feed additive.
 Contain (about 60-80%) of dry cell weight), SCP also
contains, fats, carbohydrates, nucleic acid, vitamins, and
minerals and amino acids.
 The biomass of the following microbes,
ALGAE: FUNGI: BACTERIA:
chlorella pyrenoidosa candida utilis bacillusmegatarium
spirulina maxima candida lipolytica acromobacter
dunaliella salina aspergillus niger hydrogenomus.p

5. ADVANTAGE
 Microbes require small space for mass culture.
 They can be grown in cheap raw materials and waste in
large tanks or bioreactors.
 Continuous culture of microbes is easy without the
interference of climatic factors.
 Microbial biomass is rich in easily digestible,
nutritionally valuable proteins, vitamins and minerals.
 Amin0 acid compositions of the microbe can easily be
manipulated to increase the nutritional value.
 Some microbial cultures produce secondary metabolites.
 Microbes can be cultured in any locality irrespective of
the climatic conditions.

6. ALGAE AS (SCP)- SPIRULINA
 Spirulina is a spirally coiled, multicellular, filamentous
blue green alga. Naturally found in freshwaters,
brackishwaters, marine water, hot spring and moist soils.
 The US fedral drug administration, recognized spirulina
as a supplement to human food and animal feed in 1980.
 Rich source of protein (67%), vitamins, minerals and β
carotenes.
 By 1821, spirulina maxima biomass was collected from
texococo lake and made in to biscuits and sold in
Mexico.

7. MASS CULTURE
 Spirulina is cultured in large scales in artificial ponds
or tanks or oxidation ponds.
 Cost effective culture of spirulina requires improved
biomass productivity, better light utilizations and
efficient co2 consumptions. Open system and closed
system are used to grow spirulina in large scale.
I) open circulating system
II) oxidation pond system
III) photo bioreactors

8. DRYING AND PACKING
 The harvested biomass of spirulina is washed with an
acid water( pH 4) remove toxic pollutants. Then washed
with tap water to clean acid water.
 The washed biomass is spread on polytene sheet in the
sunlight. The dried flakes are colleced and made into
powder.
 The dried biomass is packed in aluminum lined bags or
sealed bottles for marketing.
 Spray drying is followed in the dark, if the biomass has to
be used to make pills along with vitamin A and C.

9. USES;
 As healthy foods
 As therapeutic agend ex, β carotene used as cancer
research.
 Used as supplement animal feed.
 Raw material for cosmetics.

10. MICROORGANISMS AND SUBSTRATE
USED FOR PRODUCTION OF SCP
MICROORGANISMS SUBSTRATE
BACTERIA methane, methanol, alkanes,
c1-c4 hydrocarbons.
YEASTS Alkanes, sulfite liquor, whey, molasses,
methanol.
FUNGI cellulosic wastes, sulfite liquor,
molasses, straw, starch
ALGAE carbon dioxide (co2)
MUSHROOMS compost, rice straw, whey, sulfite
liquor, saw dust, cotton, straw.

11.  The selection of microorganisms for scp production is
based on several criteria. These include their nutritive
value, non pathogenic nature, production cost, raw
materials used and grown patter.
 Categories;
I) high –energy sources. e.g. alkanes, methane,
methanol, ethanol, gas oil.
II) waste products. e.g. molasses, whey, sewage,
animal manures, straw.
III) agricultural and foresty sources. E.g. cellulose,
lignin.
IV) carbon dioxide. Simple carbon source

12. PRODUCTION OF SCP
FROM HIGH ENERGY SOURCES
 There are a large number of energy rich carbon
compounds or their derivatives which serve as raw
materials for scp production.
 Include alkanes, methane, methanol, ethanol and gas
oil.
PRODUCTION OF SCP FROM ALKANES;
 Alkanes can be degraded by many yeasts, certain
bacteria and fungi.
 The major limitation of alkanes is that they are not
easily soluble, hence they cannot enter the cells rapidly.
E.g., yeasts ( candida sp., saccharomycopsis sp.,)

13.  Petroleum products for scp production:
I) gas oil or diesel oil (alkanes 10-25%)
II) short chain alkanes (C10-C17)
Degradation of alkanes:
Alkanes have to be first broken down to appropriate
metabolites for their utilization to form scp. The most
important step this direction is the introduction of
oxygen into alkanes which can be brought out by two
pathways-
I) terminal oxidation
II) sub terminal oxidation

14.  Limitations:
the major drawback of alkanes as substrates is the
formation of carcinogens, along with scp which are
highly harmful. For the reason, many countries have
discontinued alkane-based production of scp.
II) PRODUCTION OF SCP FROM WASTES:
There are several materials that serve no useful
purpose and they are collectively referred to as
waste. E.g. molasses, whey, animal manures, sewage,
straw, date wastes.
There are several advantages of utilizing waste for
the production of scp.
Thus saccharomyces cerevisiae is used for molasses,
kulyveromyces fragilis for cheese whey.

15. I)Symbha process:
Symbha process is a novel technology developed in
Sweden to produce scp by utilizing starchy wastes by
employing two yeast.
phase I: the waste material contain starch is sterilized by
passing through a heat exchanger.
phase II: the sterilized material is passed through two
bioreactor. First reactor contains E. fibuligira which
hydrolyses starch. Next it will be transfer to second
bioreactor. And later it form biomass.
phase III: biomass were separated by centrifugation. The
samples of scp can be dried, packaged and stored.
uses: used as an animal feed such as pigs, calves, and
chicken.

16. III)PRODUCTION OF SCP FROM WOOD:
 The natural waste wood sources containing cellulose,
hemi cellulose and lignin are attractive natural sources
for the production of scp.
It is however, essential to breakdown these cellulosic
compounds into fermentable sugars.
For this purpose, extracellular cellulases can be used.
certain bacteria and fungi are good sources for
cellulases.
In some instances, the cellulosic materials can be
directly used for biomass production. The resultant
scp is used as animal feed.

17. PRODUCTION OF SCP FROM CO2:
 Certain algae grown in open ponds require only co2 as
the carbon source. In the presence of sunlight, they can
effectively carry out photosynthesis, and produce scp.
 Example : chlorella sp and spirulina sp etc .,
 Uses : chlorella is used as a protein and vitamin
supplement for enriching ice-creams, breads and
yoghurts in some countries.
 The resultant algae biomass can be harvested, dried and
powdered. Used as animal feed.

18. PRODUCTION OF SCP FROM
SEWAGE
 Domestic sewage is normally used for a large scale
production of methane, which in turn may be utilized for
the production of scp.
 The sewage obtained from industrial wastes in cellulose
processing, starch production and food processing can be
utilized for the production and food processing can be
utilized for the production of scp.
 The organism candida utilis is used to produce scp by
using effluent formed during the course of paper
manufacture.

19. GENETICALLY ENGINEERED AFTIFICIAL PROTEIN AS
ANIMAL FEED
 Rumen bacteria can synthesize amino acids. Some
workers have developed genetically engineered strains
of rumen bacteria that can produce a protein rich in
methionine, threonine, lysine and leucine.
 This artificial protein has a total of 100 amino acids, of
which 57 are essential.
 However, the large scale production of artificial
protein by rumen bacteria is yet to be clearly
established and commercialized.