**5.4. CO2 emissions**

families. The analysis of seven fresh water microalgae species for the fatty acid compositions

The relative intensity of other individual fatty acids chains is species specific, e.g. C16:4 and C18:4 in *Ankistrodesmus sp*., C18:4 and C22:6 in *Isochrysis sp.,* C16:2, C16:3 and C20:5 in *Nannochloris sp*., C16:2, C16:3, and C20:5 in *Nietzsche sp.* Different nutritional and environmen‐ tal factors, cultivation conditions and growth phases may affect the fatty acid composition. For example, nitrogen deficiency and salt stress induced the accumulation of C18:1 in all treated

Microalgae have a specialty that it useful in various ways likes humans use algae as food, for production of useful compounds, as nutrient and fertilizer, wastewaters treatment and other pollutants removal from wastewater, as indicators of environmental change, in space tech‐ nology, and as laboratory research systems. Microalgae are capable of fixing CO2 in the atmosphere because when its grow using photosynthesis, also need CO2, which is waste of

Algae are rich in iodine, potassium, iron, magnesium and calcium. Algae are a complete protein with essential amino acids that are involved in major metabolic processes such as energy and enzyme production. Algae contain high amounts of simple and complex carbo‐ hydrates which provide the body with a source of additional fuel. The sulfated complex carbohydrates are thought to enhance the immune system's regulatory response. Algae contain an extensive fatty acid profile, including Omega 3 and Omega 6, which also play a key

Algae is such a biomass important which take part in treatment of ponds, pollution control and useful as a fertilizer. Nitrogen, phosphorous, potassium is important fertilizers which are requisite for the growth of the plant, knows as Nutrient. Silica, iron and some other is also useful nutrient for growth of an area such as silica is a vital nutrient for growth of diatoms (phytoplanktonic organism) which is important part of various marine food series. Same as

shows that all of them synthesized C14:0, C16:0, C18:1, C18:2, and C18:3 fatty acids.

species and to some extent C20:5 in *B. braunii*.

various sources and responsible for global warming worldwide.

**5. Current usage of microalgae**

108 Biofuels - Status and Perspective

role in the production of energy.

**5.2. Nutrient removal and fertilizer**

iron is responsible for restrain of phytoplankton.

**5.1. Food**

Microalgae can generate biomass by absorb CO2, which is produced at large-scale due to power plant gases. CO2 utilization capacity around 1.8 tonnes of CO2 will be utilized per tonnes of algal dry biomass produced, which is varies with algae species. CO2 is harmful for environment as it leads some serious issue like global warming microalgae protect environment, through photosynthesis metabolism, microalgae absorb CO2 and release oxygen.
