Phycotechnology is the applications of algae for manufacturing or service industries. It refers to the applications of micro and macro-algae. 
It includes the uses of algae in the fields of agriculture, aquaculture, production of food, feed and value added materials, Energy, Healthcare, Environment, Genomics, Proteomics, Physiological Research, Nanobiotechnology, Bionanotechnology etc. The ecosystem service provided by DiazotrophicCyanobacteria (blue-green algae) by converting atmospheric (molecular) nitrogen into bioaccessible nitrogenous compounds, is an example for Natural Phycotechnology. Use of algae by indigenous peoples for human benefits dates back to centuries. Species of Cyanobacteria like Nostoc, Arthrospira (Spirulina) and Aphanizomenonhad have been used as food for human survival during the early centuries. Microalgae are used as an excellent food and feed due to their easy digestibility and nutrient content. Algae like Chlorella and Spirulina are used as SCP. Species of Dunaliella provide richest source of high quality products like glycerol, carotenoids, proteins etc. The algal-produced proteins have biological activity comparable to the same proteins produced by traditional commercial techniques and therefore they can be the best biofactories for the production of therapeutic substances.
Currently, microalgae are being exploited for environmental protection as the species of Chlorella, Chalmydomonas, and Scenedesmus carry selective uptake, accumulation and biodegradation of pollutants and thus help in remediation. They are used in biological reclamation of sewage since they can immobilize heavy metals from aquatic systems. Microalgae can be used as biocontrol agents like ‘Insect’ a commercial bio-insecticide sold in USA, prepared from the dead biomass of diatom frustules. Microalgae are of significant use in healthcare.Chlorellin from the green microalga Chlorella effective antibiotic against Gram + ve and -vc bacteria. Algae are an excellent feedstock for green fuel as they are used for the production of biodiesel, bioethanol, biogasoline, biomethanol, biobutanol and recently biohydrogen. The full genome sequences of many species of cyanobacteria and eukaryotic algae have been used for evolutionary studies and the identification and comparison of genes coding for specific proteins. Collections of cDNAs and ETs also help in their genomic research by providing fast and inexpensive ways to discover new genes and their functions and their positions on chromosomes. Many species of diatoms are used for synthesizing nanoparticles and are being explored for their use as drug delivery systems.
- Jump up^ Lewin, Ralph A. (March 1983). “Phycotechnology: How Microbial Geneticists Might Help”. BioScience . 33 (3): 177-179. doi : 10.2307 / 1309271 .
- Jump up^ Achankunju, Jackson (9-12 July 2012). Phycotechnology – Applications of Algae for Sustainable Development (pdf) . 8th Asia-Pacific Conference on Algal Biotechnology and 1st International Conference on Coastal Biotechnology. Adelaide, Australia. pp. 1-2 . Retrieved 8 April 2007 .