Table 3.

List of microalgae derived products and co-products

Sl. no.	Products	Co-products	Strain	Yield	Productivity	Applications/advantages	References
1	Biofuel	Biodiesel	Chlorella pyrenoidosa Botryococcus sp.	95.1% 88%	1.44 g/g/h 0.22 g/g/h	Biodiesel is better than diesel fuel in terms of sulphur content, flash point, aromatic content, and bio-degradability Biodiesel is an environmentally friendly alternative liquid fuel that can be used in any diesel engine without modification Job creation for the local population, provision of modern energy carriers to rural communities	Cheng et al. (2016a, b); Sivaramakrishnan and Incharoensakdi (2017)
		Bioethanol	Chlamydomonas sp. KNM0029C Scenedesmus raciborskii WZKMT	0.22 g/g biomass 79.38 g/L	0.22 g/g/day 0.66 g/L/h	Biomethanol as a renewable fuel. Bioethanol fuel reduces lead, sulphur, CO, and particulate emissions 20% blending of bioethanol with gasoline is acceptable	Kim et al. (2020a, b); Alam et al. (2019)
		Biohydrogen	Chlamydomonas reinhardtii Rhodopseudomonas sphaeroides Botryococcus braunii Chlorella vulgaris/ Spirulina	40% v/v 45% v/v 64% v/v 70–75% v/v		Cleanest biofuel, only water as by-product High energy content as compared to gasoline	Hemschemeier et al. (2008)
2	Lipids	Eicosapentaenoic acid (EPA)	Cocculinella minutissima Monodus subterraneus Phaeodactylum tricornutum	36.7 mg/L 96.3 mg/L 43.4 mg/L		EPA is most commonly used for heart disease, preventing adverse events after a heart attack, de-pression, and menopause	McKinlay et al. (2010)
		Docosahexaenoic acid (DHA)	B. carterae Crypthecodinium cohnii Nannochloropsis oculata	8.6 mg/L 19.5 mg/L 2.6 mg/L		Reduce inflammation and your risk of chronic diseases, such as heart disease DHA supports brain function and eye health
3	Pigments	Lutein	Haematococcus pluvialis Chlorella sorokiniana MB-1	7.15 mg/g dry weight 5.21 mg/g	10.83 mg/g/h 5.78 mg/L/day	Lutein is another promising candidate in cosmetics, pharmaceuticals, and nutraceutical formulations. It can filter blue light (high-energy photons) from the visible light spectrum and can scavenge free radicals generated from biochemical reactions after lipid peroxidation	Molino et al. (2018); Chen et al. (2016)
		β-carotene	Dunaliella salina Nannochloropsis gaditana	32 mg/L 100.1	4.57 mg/L/day	β-carotene can stimulate the immune system, supplement for diseases including cancer, coronary heart diseases, premature ageing, and arthritis β-carotene prevents cataracts, night blindness, and skin diseases Used as food colourants to improve the appearance of margarine, cheese, fruit juices, baked goods, dairy products Prevention of oxidation of low density protein that can be applied to prevent arteriosclerosis, coronary heart disease, and ischemic brain development	Xi et al. (2020)
		Astaxanthin	Haematococcus pluvialis	18.5 mg/g dry weight	13.9 mg/g/h	Dietary administration of astaxanthin has proven to inhibit carcinogenesis in the mouse urinary bladder, rat oral cavity, and rat colon Astaxanthin has the ability to induce xenobiotic metabolising enzymes in rat liver Antioxidant property Protection against excessive sunlight Used in the respiratory mechanism of protoplasm	Molino et al. (2018)
		Xanthophyll	Scenedesmu almeriensis Synechococcus sp. Chlorella vulgaris Nannochloropsis gaditana	20.0 mg/L 1510 mg/L 80 mg/L 25 mg/L			Macias-Sanchez et al. (2005); Macias-Sanchez et al. (2010)
		Chlorophyll	Spirulina platensis	0.9 mg/L		Chlorophyll is an essential compound not only used as an additive in pharmaceutical but also used in cosmetic product Chlorophyll a has been extensively used as a colouring agent because of its stability Chlorophyll compounds usually have medicinal application because of their wound-healing and anti-inflammatory properties	Chauhan and Pathak (2010)
4	Proteins	Phycobiliproteins	Anabaena NCCU-9	124.9 mg/g		Phycobiliproteins are used in fluorescent labelling, flow cytometry, fluorescent microscopy, and fluorescent immunohistochemistry Used as natural dye in food and cosmectics, with phycocyanin in particular used as a blue pigment used in products such as chewing gum, popsicles, confectionary, soft drinks, dairy products, and wasabi, as well as cosmetic products, such as lipstick and eyeliner Nutraceutical applications such as anti-oxidative, anti-inflammatory, anti-viral, anti-tumour, neuroprotective, and hepatoprotective activities Used as animal feed	Hemlata and Fatma, (2009); Silveira et al. (2007); Chaneva et al. (2007)
		Phycocyanin	Spirulina platensis Arthronema africanum	0.0036 mg/L 0.23 mg/L	0.0009 mg/L/h
5	Vitamins	Thiamine	Tetraselmis suecica	493–750 mg		Used as food supplements Used as drug supplements to treat diseases including malnutrition	Safafar et al. (2015)
		Riboflavin	Dunaliella tertiolecta	31.2 mg
		a-tocopherol	Chlorella stigmatophora	669 µg/g