Extraction of extracellular and intracellular carotenoid pigment from wild strains of Rhodotorula: A comparitive study

Abstract

Carotenoids are natural pigments produced by a wide range of microorganisms (i.e., fungi, yeasts, bacteria, and microalgae), lichens, and plants. These pigments are responsible for creating colors, such as yellow, orange, red, and pink in plants, fish, and shellfish in aquaculture and microorganisms. Carotenoids have numerous applications in food, feed, medical, pharmaceutical, chemical and cosmetic industries. Nowadays, a lot of pigments is chemically synthesized, however, their application in food, pharmaceutical, and cosmetic industries is limited due to their toxicity. Carotenoids are commercially produced by using microorganisms that have high efficiency and are also easy to work with. Many research have been carried out on carotenoids biosynthesis by microorganisms, such as bacteria (e.g., Dietzia), algae (e.g., Haematococcus), fungus (e.g., Phycomyces), and yeast (e.g., Rhodotorula).Among yeast, Rhodotorula sp. produces both extra and intracellular carotenoid pigments. The pigment producing 11 isolates of Rhodotorula were obtained from air (3), apple (4), can milk (2) and yoghurt (2). Phenotyped Rhodotorula minuta RAI3; Rhodotorula acheniorum RC2, Rhodotorula sp RA2, Rhodotorula minuta RY1 were selected for pigment production. Sterile synthetic media Malt Yeast Extract Agar (MYEB), coconut water as liquid media and rice as solid substrate medium were used for extracellular and intracellular pigment production from Rhodotorula minuta RAI3; Rhodotorula acheniorum RC2, Rhodotorula sp RA2, Rhodotorula minuta RY1. Coconut water and rice media showed production of extracellular and intracellular pigment at 300C for 6 days. Among the 4 isolates, Rhodotorula minuta RAI3 showed maximum intracellular pigment production of 4.412 μg/g of dry cell mass compared to extracellular1.20 µg/g of dry mass respectively.