1. Food biotechnology
Topic: Algae and bacteria as SCP
Submitted to : Dr. Ranjeeta Bhari
Submitted by: Jashanpreet kaur
Class: M.Sc. BT (II) Sem (III)
Roll no: 19011001
2. INTRODUCTION
• The term SCP is used to describe protein derived
from cells of microorganisms such as yeast, fungi,
algae and bacteria which are grown on various
carbon sources for synthesis.
• Dietary protein supplement.
• SCP can be used as a protein supplement for
humans &animals.
• Food grade
• Feed grade
3. HISTORY
• The term SCP was coined in 1966 by corroll L.wilson of MIT.
• Research on single cell protein technology started a century ago
when MAX DELBRUCK and his colleagues found out the high value
of surplus brewer’s yeast as a feeding supplement for animals.
• Earlier known as “Microbial protein”.
• It otherwise known as “Novel food” or “mini food”.
• Thus, SCP is of high nutritional value for human or animal
consumption.
• Pruteen was first commercial SCP used as a animal feed additive.
• Pruteen was produced from bacteria Methylphilus methylotrophs
cultured methanol and had 72% protein content.
4. SCP PRODUCTION IN INDIA
• National Botanical Research Institute (NBRI).
• Central Food Technological Research Institute
(CFTRI).
• In CFTRI, SCP is produced from algae cultured
on sewage.
5. Microorganisms used SINGLE-CELL PROTEINS
• Various microorganisms used for the
production of SCP are bacteria
(Cellulomonas, Alcaligenes, etc.),
• Algae (Spirulina, Chlorella, etc.),
• Molds (Trichoderma, Fusarium, Rhizopus,
etc.) and
• Yeast (Candida, Saccharomyces, etc.)
6. Algal strains used for SCP production:
• Spirulina sps.
• Chlorella pyrenoidosa
• Chondrus crispus
7. • For cultivation of algae on sewage wastes,
oxidation ponds are prepared, where sewage
is allowed to accumulate.
• It is awaited till mixed cultures of algae grow
(or inoculated with a singly prepared algal
culture).
• For example, in Japan mixed culture
of Chlorella ellipsoides and Scenedesmus
obliguus was developed in open pond
systems.
8. Algal Biomass
• Algae grows auto- tropically.
• Requires low intensity of light.
• Temperature 35 - 40 C & pH – 8. 5 -10.5
• Cultivated in large trenches of sewage
oxidation ponds.
9. Factors Affecting Biomass Production
(i) Illumination time;
(ii) Light intensity;
(iii) Supply of CO2. Concentrations of CO2 differ in different
conditions,
for example, an alkaline lake. Lake Texcoco in Mexico, has
high concentration of sodium carbonate. On the other
hand, algal growth is limited as a result of liberation of
CO2 and ammonia by bacterial activity;
(iv) Nitrogen sources (ammonium salts or nitrates are the
suitable nitrogen sources which increase biomass yield);
(v) Agitation of growing cells to maintain cells in suspension.
10. PRODUCTION OF SCP
• Preparation of nutrient media
• Fermentation
• Separation and mechanical concentration of
SCP
• Drying the SCP
• Final processing of the SCP
11. Production process outline
• Cultivation : Selected strains of algae are used for cultivation
in constant agitation of water. This is an important parameter in
the cultivation of spirulina. Agitation of algae culture is
necessary to keep nutrients evenly dispersed and also to
expose all the cells to sunlight.
• Harvesting : The algal biomass is carefully harvested using
specially made filters to recover the biomass. The special filter
has a mesh size is 0.5 Microns.
• Processing : The harvested biomass is dried using the cross
flow drier. The produce obtained is in the form of flakes. It is
ground in the pulveriser to get the powder of the desired mesh
size. To get an optimal yield, maintenance of required nutrient
level, cell density, culture depth etc., are some of the critical
parameters in the process of spirulina cultivation. The yield of
spirulina is expressed as grams per cubic metre per day.
12.
13. A. Major constituents
(%)
C. Minerals (mg)
Total protein 64.6 Calcium 6.58
Fat 6.7 Phosphorus 977
Crude fiber 9.3 Iron 44.7
Carbohydrates 16.1 Sodium 796
Calories 346 Potassium 1.28
B. Vitamins D. Essential amino
acids (%)
Beta - carotene 320,000IU Lysin 2.99
Biotin 0.22 mg Cystine 0.474
Cyanocobalamin (B12) 65.7 mg Methionine 1.38
Folic acid 17.6 mg Phenylalanine 2.87
Riboflavin 1.78 mg Threonine 3.04
Thiamin 0.118 mg
Tocopherol 0.773 IU
14. Requirements for Growth of Spirulina
(i) Algal tanks. circular or rectangular cemented tanks are constructed. The
circular tanks are more preferred over the rectangular one because of ease in
handling. Size may be according to convenience and yield needed. Depth
should be about 25cm. Open tanks are suitable for tropical and subtropical
regions.
(ii) Light. Low light intensity is required at the beginning to avoid
photolysis. Spirulina exposed to high light intensity is lysed.
(iii) Temperature. Temperature for optimum growth should be between 35-40°C.
(iv) pH. Spirulina grows at high pH ranging from 8.5 to 10.5. Initially, culture
should be maintained at pH 8.5 which automatically is elevated to 10.5.
(v) Agitation. Agitation of culture is very necessary to get good quality and better
yield. The culture is agitated by brush, paddle power, pipe pumps, wind power,
rotators, etc.
(vi) Harvesting. The filaments of Spirulina float on surface of water forming thick
mat. Therefore, it can be harvested by fine mesh steel screens, nylon or cotton
cloths, etc.
15. (vii) Drying. As it has a thin wall, sun drying is the most
suitable and economical. Various trials done at CFTRI,
Mysore and MCRC, Madras with sun drying have given good
results.
(viii) Yield. An average yield of 8-
12g Spirulina powder/m2/day has been obtained in India
and other countries. This is equivalent to 20 tonnes
/ha/annum. In warmer climate, the yield can increased to
about 20 g/m2/day.
(ix) Avoiding contamination. Although there is the least
chance for contamination, yet regular monitoring of algal
culture is necessary. Because the microbial load is likely to
affect the quality and safety of the product.
Dried Spirulina powder is packed in aluminium bags or
sealed in bottles and sent to market.
16. • Mass Cultivation of Spirulina SCP
At present two types of farms for mass
production of Spirulina SCP are under
operation. A third type (i.e. enclosed system
using transparent tube, biocoil or
photobioreacter) is under development
(Henrikson, 1990).
17. (i) Semi-natural lake system.
• Sosa Texcoco Lake (Mexico)
and Lake Chand (Africa)
offer an ideal environment
for the natural growth
of Spirulina.
• The product is expensive
but of low quality due to
contamination and pollution
by uncontrolled natural
factors. SCP of these lakes
are good for fish and animal
feed.
(ii) Artificially built
cultivation system.
• The climatic conditions of
most of the developing
countries are such that
favor mass outdoor
production of Spirulina.
• on the basis of water quality
and nutrient status, this
system can be grouped into
the following two :
18. (a) Clean water system.
• This system is more expensive because of construction of artificial cultivation
farms.
• These have shallow raceway ponds circulated with paddle wheels and high
quality of nutrients.
• For the fast growth of Spirulina in clear water, addition of NaNO3 and NaHCO3 is
necessary.
• pH of the water must be initially maintained to 8.5. It is a self pH adjusting alga
which elevates the pH between 10-10.5. At this pH levels there is the least
chance of contamination.
In India, food grade Spirulina is cultivated at two main centres, one at Shri
A.M.M. Murugappa Chettiar Research Central (MCRC), Madras, and the other
at Central Food Technology and Research Institute (CFTRI), Mysore.
Madras centre is the biggest food grade Spiulina farm in India. Its annual
production capacity is of about 75 tonnes. The products are marketed in India
and abroad as health food, baby food and multivitamin tablets.
19. (b) Waste water system.
• This system is applicable in highly populated countries like India
where wastes are generated in high quantities and pose
environmental problem.
• In this system, human and animal wastes and sewage are used for
growth of Spirulina. The wastes are added into the digester to settle
down the solid particles.
• The liquid effluent is used as a source of the nutrients and added in
artificially constructed ponds. As desired NaNO3 and NaHCO3 are also
mixed. S. platensis is found to grow better in sewage amended with
NaCO3 and nutrients in different proportion and also in diluted
sewage.
• When full growth of Spirulina is over, it is screened from the pond
and added to aquaculture to feed fish or dried in a small solar drier
for human food.
20. Uses of Spirulina Single Cell Protein
• As protein supplemented food. Since Spirulina is a
rich source of protein (60-72%), vitamins, amino acids,
minerals, crude fibers, etc., it is used as supplemented
food in diets of under-nourished poor children in
developing countries
• As health food. Spirulina is very popular as health
food. Most of Sosa Texcoco products are exported to
USA, Europe and France where it is sold in health and
food stores. It is the part of the diet of the US Olympic
team. Joggers take Spirulina tablets for instant energy.
21. • In the therapeutic and natural
medicine. Spirulina possesses many medicinal
properties. Therefore, it is used as social and preventive
medicine also. It has been recommended by medicinal
experts for reducing body weight, cholesterol and pre-
menstrual stress and for better health.
• In cosmetics. Spirulina contains high quality of proteins
and vitamin A and B. These play a key role in maintaining
healthy hair. Many herbal cosmeticians are making
efforts to develop a variety of beauty products.
Phycocyanin pigment has helped in formulating
biolipstics and herbal face cream in Japan. These
products can replace the present coaltar-dye based
cosmetics which are known as carcinogenic.
22. LIMITATIONS FOR USE OF SCP
Although algae are very good nutrition sources, there are
some limitations for human consumption:
• The most important one is the presence of the algal cell
wall. Humans lack the cellulose enzyme and hence they
cannot digest the cellulose component of the algal wall.
• In order to be used as food for humans the algal walls
must be digested before the final product is eaten.
• The cellulose digestion step is not required if the SCP is
used as feed for cattle as they have cellulose-degrading
symbiotic bacteria and protozoa in their rumen.
• Algal production is generally done outdoors and is
dependent on the climatic conditions. Hence, productive
algal species and favorable conditions are important.
24. WHY USE BACTERIA AS SCP?
1. High protein contents (35–60%).
2. Less generation time than other microbes.
3. Good nutritional value than conventional
foods rich in protein.
4. Production in fermenters without requiring
land.
5. Ease of genetic manipulation to improve
production and product quality.
25. FACTOR AFFECTING BACTERIAL BIOMASS
PRODUCTION
• Sterile conditions
• Nutritional value of substrate
• Temperature
• pH (5-7)
• Suitable strains
• Agitation/aeration
• Genetic stability
• Absence of bacteriophage
26. RAW SUBSTRATES
• Renewable Resources Lignocellulosic material
(Agriculture/forests waste)
• High carbon contents (sugars)
• Seasonal availability
• High cost of processing Non-Renewable
Resources
• Petrochemical substrates (gas–oil/paraffins)
• Easy availability
• High productivity
• Toxicity issues
27. STPES FOR BACTERIAL BIOMASS PRODUCTION
• Processing of substrate & media Sterilization
process
• Inoculum preparation
• Inoculation of production media
• Maintenance of fermentation process
• Incubation under controlled conditions
• Product recovery
• Product purification
• Final treatment/ packing
28. Among the characteristics that make bacteria
suitable for this application include:
• Their rapid growth.
• Their short generation times; most can double their cell mass in 20 minutes to 2
hours.
• Capable of growing on a variety of raw materials, ranging from carbohydrates
such as starch and sugars, to gaseous and liquid hydrocarbons such as methane
and petroleum fractions, to petrochemicals such as methanol and ethanol.
• Suitable nitrogen sources for bacterial growth include ammonia, ammonium
salts, urea, nitrates, and the organic nitrogen in wastes.
29. • Cultivation of Bacteria (Methylophilus
Methylotrophus)
Bacterial species used for single cell protein production
should:
• Grow best in slightly acid to neutral pH in the range 5
to 7.
• Tolerate temperatures in the range 35 to 45 degrees
Celsius as heat is released during bacterial growth.
• Be non-pathogenic for animal, human or plants
depending on who the end product is intended for.
30. Production of SCP from Methylophilus
Methylotrophus
• Methanol is used as substrate. 2 metric tons of methanol yield
around 1 metric ton of dry single cell protein. Methanol has
several advantages over methane and many other carbon sources,
particularly because it is completely miscible with water and is
available in a very pure form.
• In addition to the carbon source, nutrient sources which can
provide phosphorus, nitrogen, calcium and potassium must be
provided in order to support optimal growth.
• Prevention of contamination of the medium and the plant can be
done simply; by maintaining sterile and hygienic conditions. The
medium components may be heated or sterilized by filtration. The
circulating air and the gaseous components of the medium (NH3,
CO2) are sterilized by passing through specialized filters.
31. • It is a common practice to sterilize other components by passing through steam. In
addition to the components required for the fermentation and medium
components the fermentation equipment is also sterilized. Filter-sterilized
compressed air is used for both agitation and oxygenation.
• Production of the microorganism; the desired micro organism has to be produced in
a sufficient quantity in medium best suited for its growth, then inoculated into a
medium similar to the fermentation medium and finally introduced into the main
fermentation broth. At each step the purity of the culture has to be checked and
can be done either by Gram staining or plating of the inoculated medium on to
microbiological media. Fermentation was performed at pH 6.5 – 6.9 and 34-
37oC. Aeration is necessary for most of SCP production.
• Recovery of the microbial biomass from the spent medium: Methods available for
concentrating single cell proteins include filtration, precipitation, coagulation,
centrifugation and the use of semi permeable membranes. Bacterial cells are
recovered by flocculation which is promoted by acid and heat shock. Centrifugation
is an effective concentration method which requires a high velocity rotor because of
the microscopic size and low specific gravity and density of the cells and viscosity of
the medium.
32. • Single cell protein must be dried to about 10% moisture, or
condensed and has to be acidified to prevent spoilage from
occurring or can alternatively be fed shortly after being
produced. In addition to acidification for preservation
purposes, it is also necessary to decrease the concentration of
nucleic acid. Some of the methods employed for reducing
nucleic acid content in microbial biomass are, alkane
hydrolysis, chemical extraction, and activation of endogenous
nucleases during final stage of microbial biomass production.
• The resulting product is the dried biomass of bacteria which
appears pinkish-white, is odourless, tasteless and non-toxic. It
consists of about 65-75% protein of balanced amino acid
compilation.
33.
34. DISADVANTAGES
Although the cost of producing SCP form bacteria is
relatively high due to the following factors:
• Bacterial cells have small size and low density,
which makes harvesting from the fermented
medium difficult and costly
• Bacterial cells have high nucleic acid content
relative to yeast and fungi. To decrease the
nucleic acid level additional processing step has
to be introduced and this increases the cost.
