Potential of terrestrial microalgae and cyanobacteria in environmental technology

Terrestrial algae and cyanobacteria are widely distributed in special habitats. The observations in the field studies made by the authors' team are presented herewith: 1. Species composition and distribution of terrestrial algae in the paddy field, dry farmland and desert in the river basins of Changjiang (Yangtze), Yellow River and Helongjiang River in China, at various climate conditions are reported. A general mode of the vertical distribution is summarized. 2. Soil fertility improvement and bio-fertilizer development using terrestrial nitrogen-fixing microalgae have demonstrated their potential as the soil conditioner for dry farmland. 3. Results revealed that the potential of desert algae in desert fixation (colonization) is due to their capability to survive, ability to conglutinate sandy granules and resistance of the algal crust against wind-erosion. Artificial inoculation in field trials with desert algae in situ accelerated colonization of desert. 4. Useful species e.g. edible Nostoc were investigated. Utilization of useful products such as polysaccharides, growth promoting substance, pigments, polyunsaturated fatty acids (PUFA) from the terrestrial algae were looked into. Results on polysaccharides from three species of Nostoc are briefly discussed.