Comparative Analysis of β-Carotene Production by Mucor circinelloides Strains CBS 277.49 and WJ11 under Light and Dark Conditions

Abstract

Carotenoids are natural potent antioxidants and free radical scavengers which are able to modulate the pathogenesis of some cancers and heart diseases in human, indicating their importance in being provided through the diet. Mucor circinelloides accumulates β-carotene as the main carotenoid compound and has been used as a model organism in carotenogenic studies. In the present study, the potential of two M. circinelloides strains to accumulate β-carotene was investigated under light and dark conditions. The results, which were quantitated by HPLC, showed that CBS 277.49 accumulated higher pigment in comparison to WJ11 under both conditions. Continuous illumination triggered the pigment accumulation up to 2.7-fold in strain CBS 277.49 and 2.2-fold in strain WJ11 in comparison to dark. The mRNA analysis of the four key genes involved in isoprenoid pathway by RT-qPCR showed higher transcriptional levels in CBS 277.49 as compared to WJ11, indicating that the pigment production metabolic machinery is more active in CBS 277.49 strain. A new scope for further research was established by this work for improved β-carotene production in the high producing strain CBS 277.49.

Increased Accumulation of Medium-Chain Fatty Acids by Dynamic Degradation of Long-Chain Fatty Acids in Mucor circinelloides

“…Complete loss of the ACOX gene resulted in reduced growth in comparison to the control strain, ultimately confirming the negative effect of the genetic modification on fungal cells (i.e., M-2) ( Figure 4 A). Transformation and positive colony selection were carried out according to the method described by Rodríguez-Frómeta et al [ 8 ]. To obtain stable mutants with enriched recombinant nuclei, the mutant strains were subjected to three rounds of vegetative growth.…”

“…Owing to its high-oil-generating ability, it offers a reliable option for genetic modulation to produce functional lipids and green energy fuels [ 8 , 9 ]. Previously, these fungal strains have been engineered to produce biofuels and microbial lipids consisting mostly of long alkyl-chains (C14 or more carbons), ultimately making them less attractive for diverse industrial applications [ 8 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. Metabolic engineering of M. circinelloides for the production of MCFAs would facilitate the generation of renewable commodities [ 4 , 18 ].…”

Comparative Analysis of Different Isolated Oleaginous Mucoromycota Fungi for Their γ-Linolenic Acid and Carotenoid Production

“…Carotenoid extraction was done as described previously by Naz et al [ 25 ]. Briefly, 100 mg of mycelia powder was taken and dissolved in 1 mL hexane in a 10 mL screw tube, and vortexing was done.…”

Redirecting Metabolic Flux towards the Mevalonate Pathway for Enhanced β-Carotene Production in M. circinelloides CBS 277.49

“…Extraction of β- carotene was done according to our previous investigation [ 21 ]. Briefly, 100 mg of mycelia powder, which was grinded under liquid nitrogen after freeze-drying, was dissolved in 900 μ L of hexane, followed by a vortexing step.…”

“…Our previous finding indicated M. circinelloides strain CBS 277.49 as a dominant producer of β -carotene than M. circinelloides strain WJ11 [ 21 ]. So, in the current investigation, strain CBS 277.49 was nominated as a suitable candidate.…”