Regulation of carotenoid degradation and production of apocarotenoids in natural and engineered organisms

Abstract

Carotenoids are important precursors of a wide range of apocarotenoids with their functions including: hormones, pigments, retinoids, volatiles, and signals, which can be used in the food, flavors, fragrances, cosmetics, and pharmaceutical industries. This article focuses on the formation of these multifaceted apocarotenoids and their diverse biological roles in all living systems. Carotenoid degradation pathways include: enzymatic oxidation by specific carotenoid cleavage oxygenases (CCOs) or nonspecific enzymes such as lipoxygenases and peroxidases and non-enzymatic oxidation by reactive oxygen species. Recent advances in the regulation of carotenoid cleavage genes and the biotechnological production of multiple apocarotenoids are also covered. It is suggested that different developmental stages and environmental stresses can influence both the expression of carotenoid cleavage genes and the formation of apocarotenoids at multiple levels of regulation including: transcriptional, transcription factors, posttranscriptional, posttranslational, and epigenetic modification. Regarding the biotechnological production of apocarotenoids especially: crocins, retinoids, and ionones, enzymatic biocatalysis and metabolically engineered microorganisms have been a promising alternative route. New substrates, carotenoid cleavage enzymes, biosynthetic pathways for apocarotenoids, and new biological functions of apocarotenoids will be discussed with the improvement of our understanding of apocarotenoid biology, biochemistry, function, and formation from different organisms.

Keywords:

• Carotenoid cleavage oxygenase (CCO)
• apocarotenoid
• carotenoid
• carotenoid cleavage products
• regulation of carotenoid degradation
• metabolic engineering

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [31871778, 31801468, and 32072201], Guangdong Basic and Applied Basic Research Foundation [2019A1515010656], Fundamental Research Funds for the Central Universities [2018MS89], Guangdong Province Science and Technology Plan Project [2016A010105002], Guangdong Provincial Bureau of Ocean and Fishery Science and Technology to Promote a Special [A20161A11], and China Postdoctoral Science Foundation [2020M682717, 2018M630950 and 2019T120733].