Culture of algae in laboratory is not only important for knowing the details of the external morphology and reproduction in a particular algae or algal group, it is equally important to know the details of algal life-histories, taxonomy, physiology, biochemistry, genetics and also its ultra-structure. Most of the development in this field have taken place mainly during the last 45 years.
For instructions in the laboratory, the algal cultures, should either be started from the fresh collections from the field or may also be procured from some ‘culture-supplying agencies’ of the world. The first step for the laboratory culture, therefore, is the isolation of the required material. Under isolation may be isolated single cells, colonies, filaments or fragments. The second step is to transfer the isolated material into a suitable culture medium.
Scope of algal culture
Advancement in the knowledge of algae whether of their biochemistry, genetics or role in the natural environment depends largely on the use of cultures. The organisms that grow and multiply in a special nutrient medium which is called culture medium.
If the algae are grown in artificial culture then several aspects of algal cultures may be undertaken. The scope of algal culture are-
- It is possible to trace the life cycle of a species and learn morphological and genetical phases of the life cycle of the algae.
- To study the manner of gamete formation, gamete union, ecological factors related to reproductive phases.
- To determine the morphological and reproductive characteristics as aids in establishing taxonomic criteria and developing phylogenetic relationships.
- To produce specimens for cytological and ultra-microscopical examination of cell structure, organelles and cell divisions.
- To study the physiology of algae and apply information to other plants-photosynthesis, respiration, nutrients requirements, response to light, temperature.
- To study the elaboration of extra metabolites, endo- or exo-toxins, antibiotics.
- To determine chemical composition of algae for both practical and scientific purposes.
- To study production and productivity rate and theri relationships to limnology, to food chain of aquatic animals and as food for domestic animals and for men (e.g. Spirulina platensis).
- To study and test algicides, their effects on different spp. and their use in various concentration.
- To study relationships of algae to water quality or sanitation.
Kinds of algal culture
Bold and Wynne (1978) have summarized the following kinds of cultures:
- Clonal culture
A culture obtained from one single cell or fragment of an individual is called a clonal culture. It is used to conduct experiments in genetic homogeneity.
2. Axenic culture
A culture obtained from one strain or an algal species, separated from all other strains, species or other living organisms (protozoa, bacteria or some fungi) is called axenic culture or pure culture.
3. Unialgal culture
A culture obtained from one strain or species of an alga is called unialgal culture. In such cultures other living organisms (protozoa, bacteria or fungi) my also be present.
Chu 10 Medium
Chu (1942) suggested the use of following medium for culturing many algae, especially Myxophyceae.
|K3HPO4||.01 or, .005|
Solidify the medium by adding 15 g/l agar.
- Textbook of Algae by O P Sharma