1.6. Marine pigments:
The pigment is a secondary metabolite produced by microbes. Pigments are the mixture of chemical compounds with varied biological activities. Marine bacteria Rubritalea squalenifaciens Planococcus maritimusproduces acetylenic carotenoids, Flavobacterium dehydrogenase, Halococcus, Halobacteria, Actinomycetales, produces aryl carotenoids such as 3-hydroxy-isorenieratene, isorenieratene and Streptomyces mediolani , Monascus, Rhodotorula Brevibacterium linens, Mycobacterium aurum , marine Pseudoalteromonas , marineActinomycetes , and marine blue-green algae produce 3,3′-di-hydroxy-isorenieratene carotenoid.
Carotenoids extracted from Phaffia rhodozyma andHaematococcus pluvialis are used in aquaculture pharmaceuticals and food additives. H.pulvialis produces astaxanthins, which have an application in aquaculture feeds as well as a role in memory improvement and antiaging (Ramesh et al., 2019). As a food additive, Xanthan gum, an exopolysaccharide generated by Xanthomonas campestris , is utilized. Flexirubin, which is generated by Chryseobacterium and Flavobacterium, is used to treat chronic skin illness, dermatitis, stomach ulcers, and other conditions. Marine bacterial pigments can be used as pollution indicators in biosensors (Venil et al., 2014).