Effect of Nutrients on Diatom Growth: A Review

Diatoms are one of the unicellular algae with a rare presence of unaltered, durable, transparent and species-specific silica frustules that persist even after cell death in the deposits of water bodies. Diatom has high capacity for absorption of metals for maintaining the water quality and high rate of multiplication. These characters promoted the use of this microbial biomass for effluent detoxification. These diatoms can also solve metal toxicity problems in aquatic ecosystems in the water polluted environment. In the present review, the focus is on several nutrients (nitrogen, phosphorus, iron and silica) that are essential for the growth of diatoms at very low concentrations, but most of them are toxic at high concentrations. It also shows the relationship between heavy metal stress and lipid body induction which may be a valuable indicator for the evaluation of heavy metal contamination of fluvial ecosystems. HIGHLIGHTS Diatoms are eukaryotic, unicellular, photosynthetic, silica-containing microscopic algae with distinct geometric forms Diatoms are used for biomonitoring purposes for taxonomic and morphological properties of ecosystems, community and human disturbances Diatoms are also the primary producer of oil in the world responsible for fixing 25 % of CO2 and 30 % of crude oil diatoms Many diatoms are appropriate for lipid development up to 70 % of their body volume and are investigated for biofuel as a hotspot GRAPHICAL ABSTRACT