ICAR Research Data Repository for Knowledge Management

The need to feed and provide for a rapidly growing world population and the dwindling of many natural resources have placed present day, agriculture at crossroads. About three-quarters of all fertile land in the temperate and tropic zones is now devoted to agriculture. Science-based rather than resource-based agriculture is considered important for obtaining high productivity. This is achievable by prudent utilization of unique environments which would support Earth's natural ecosystems. In this context, large-scale microalgal culture represents an interesting possibility.Algae represent two-thirds of the Earth's plant biomass [1]. Thousands of these algal species covering the Earth are now being identified and developed for food, Pharmaceuticals, biochemicals and fertilizers. As human food, microalgae have appeared at several interesting junctures in human history. They range in size from a single cell to a giant kelp of nearly 150 feet long. Most algae live depending on sunlight through photosynthesis, but some depend on organic matter. Microalgae in the ocean, called phytoplankton form the base of the food chain and support all higher life. The rich upwellings of nutrients caused by the major currents from the sea, or nutrients from major river basins sustain phytoplankton growth. There are blue-green microalgae like Spirulina and Anabaena, green algae like Chlorella and Scenedesmus, red algae like Dunaliella, and also brown, purple, pink, yellow and black microalgae. They are everywhere-in water, in soils, on rocks and on plants. Blue-green algae are the most primitive organisms, and contain no nucleus or chloroplast. Their cell walls are composed of mucopolysaccharides responsible for the soft, slimy nature of the organisms.