Algae culture: what is algae culture algae culture methods ........harvesting , commercial importance, social benefits,applications of algae and problems in algae culture.
3. Algae are simple
autotrophic organisms that
grow in fresh water as well
as marine water . There are
more than 500 species of
algae like green algae , red
algae , brown algae etc.
The algae range is large &
diverse that varies from
unicellular to multi-cellular
forms , micro algae to macro
algae , simple forms to most
complex marine forms
called sea weeds.
4. Algae culture is a form of aquaculture in which different
species of algae are grown.
Algae can be grown in…….
1 Fresh water
2 Marin water
Algae culture may be done as……
1 Mono culture (single species)
2 Multi culture (different species)
5. Open ponds
Raceways
Photo bioreactors
Plastic membranes
While the simplest and cheapest of above is open-
pound system .It is prone to contamination and subject to
weather.
6. A pond of 0.5 -1.0 ha with access to both salt and fresh
water is needed so that the salinity can be adjusted and
the water can be changed every 2-3 days.
Water change is usually made using tidal flows with gates
to control the in flow and out flow of water .
The pH of the pond water is important slightly alkaline
(pH 8)
The pond should be drained to the depth of 0.3 meters.
Plant the algal cutting in the mud.
After planting , flood the pond slowly to the depth of about
0.5 to 0.8 m.
7.
8. Raceway pond used
to cultivate
microalgae. The
water is kept in
constant motion
with a
powered paddle
wheel.
9. Algae can also be grown in a photobioreactor (PBR). A
PBR is a bioreactor which incorporates a light source.
Virtually any translucent container could be called a
PBR; however, the term is more commonly used to
define a closed system, as opposed to an open tank or
pond.
Because PBR systems are closed, the cultivator must
provide all nutrients, including CO2.
10. Different types of suspended
culture PBRs include:
Tanks
Polyethylene sleeves or bags
Glass or plastic tubes.
11. When cultivating algae on algae farms, there are some
basic requirements for producing a good stock, regardless
of the species. Light, water, and minerals are all important
ingredients in producing healthy algae. So is carbon
dioxide. This combination produces the energy algae
needs to grow.
Algae can sometimes be grown without sunlight if sugar is
used to directly feed it. In these cases, carbon dioxide is
also not required to grow the algae. Most algae farmers
prefer the light method.
12. Most types of algae that are commercially grown are
microalgae. These are sometimes referred to as
phytoplankto, microphytes, and planktonic algae. Some of
the larger algae species, also known as macroalgae,
include seaweed and also have commercial uses.
However, their larger size and the more precise growing
conditions for macroalgae make them more challenging to
cultivate in a controlled environment.
13. A seaweed
farmer in Nusa
Lembongan gath
ers edible
seaweed that has
grown on a rope.
15. Arthrospira platensis is a planktonic filamentous cyanobacterium
composed of individual cells (about 8 mm diam.), which grows in
subtropical, alkaline lakes with a temperature optimum of about 35
C. In productive cultures, Arthrospira is cultivated in shallow,
mixed ponds or semi-closed, tubular photobioreactors. The growth
medium contains inorganic salts with a high concentration of
bicarbonate, keeping the pH value between 9 and 10. This
cyanobacterium is the most cultivated photosynthetic prokaryote,
since
its biomass is widely used as a health food, feed supplement, and as a
source of fine chemicals
16. Chlorella (green algae;
Chlorophyta) is a
cosmopolitan genus with
small globular cells (about
2-10 mm diam.) living in
both aquatic
and terrestrial habitats. It
includes strains with a
high temperature
tolerance, since some
strains can grow between
15 and 40 C
17. The green halophilic
microalga Dunaliella
salina (Chlorophyta) and
similar hypersaline
strains have biflagellated,
pear-shaped cells.
Dunaliella is the main
natural source of b-
carotene in high amounts,
it being up to 16% of dry
matter. Their cells lack a
rigid cell
wall, having instead a thin
elastic plasma membrane.
Dunaliella salina
18. Haematococcus pluvialis
(Chlorophyta) is a
freshwater, unicellular
green microalga with a
rather complex life cycle.
Among various
natural sources,
Haematococcus is an
exclusive producer of
astaxanthin (pink
carotenoid)
19. When it comes to harvesting algae, several different
methods can be used. The most common are flocculation,
centrifugation, and microscreening. Flocculation is an
expensive method of harvesting algae that only large algae
farms can usually afford.
It uses the powdered shells of crustaceans to interrupt the
carbon dioxide supply of the algae, which causes algae to
float to the surface of the water where it can be skimmed.
Centrifugation spins the water containing the algae in a
centrifuge to separate the algae from the water and is a
medium-cost method of harvesting due to the cost of the
centrifuge. Finally, microscreening simply uses a fine mesh
screen to sift the algae directly out of the water.
20. Consumer goods
Health & nutrition
Fuel
Industrial application
Agriculture
Power generation
21. Not withstanding diverse applications &
commercial uses of algae, the algae culture
also offer following social benefits:
Pollution control
a) Air pollution
b) Water pollution
Poverty alleviation
22. Consumer goods:
Tooth paste , ice creams, chocolates, cool
drinks, jams ,jelly and many other
processed foods.
Health & nutrition:
a) Medicines for cancer, heart disease,
tumors, aging, skin diseases etc.
b) Nutritional supplements
Fuels:
Bio diesel can produce from algae.
23. Most people are ignorant about size & scale
of opportunities in algae culture industry .
The financiers & bankers are not aware of
this industry .
Production quality & quantity in open pond
method is subject to environmental
conditions .
There is no processing units in access to
marginal producers.