scholarly journals Genetic Modification of Mucor circinelloides for Canthaxanthin Production by Heterologous Expression of β-carotene Ketolase Gene

2021 ◽  
Vol 8 ◽  
Author(s):  
Tahira Naz ◽  
Junhuan Yang ◽  
Shaista Nosheen ◽  
Caili Sun ◽  
Yusuf Nazir ◽  
...  

Canthaxanthin is a reddish-orange xanthophyll with strong antioxidant activity and higher bioavailability than carotenes, primarily used in food, cosmetics, aquaculture, and pharmaceutical industries. The spiking market for natural canthaxanthin promoted researchers toward genetic engineering of heterologous hosts for canthaxanthin production. Mucor circinelloides is a dimorphic fungus that produces β-carotene as the major carotenoid and is considered as a model organism for carotenogenic studies. In this study, canthaxanthin-producing M. circinelloides strain was developed by integrating the codon-optimized β-carotene ketolase gene (bkt) of the Haematococcus pluvialis into the genome of the fungus under the control of strong promoter zrt1. First, a basic plasmid was constructed to disrupt crgA gene, a negative regulator of carotene biosynthesis resulted in substantial β-carotene production, which served as the building block for canthaxanthin by further enzymatic reaction of the ketolase enzyme. The genetically engineered strain produced a significant amount (576 ± 28 μg/g) of canthaxanthin, which is the highest amount reported in Mucor to date. Moreover, the cell dry weight of the recombinant strain was also determined, producing up to more than 9.0 g/L, after 96 h. The mRNA expression level of bkt in the overexpressing strain was analyzed by RT-qPCR, which increased by 5.3-, 4.1-, and 3-folds at 24, 48, and 72 h, respectively, compared with the control strain. The canthaxanthin-producing M. circinelloides strain obtained in this study provided a basis for further improving the biotechnological production of canthaxanthin and suggested a useful approach for the construction of more valuable carotenoids, such as astaxanthin.

Metabolites ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 38 ◽  
Author(s):  
Tahira Naz ◽  
Shaista Nosheen ◽  
Shaoqi Li ◽  
Yusuf Nazir ◽  
Kiren Mustafa ◽  
...  

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.


2008 ◽  
Vol 78 (1) ◽  
pp. 131-137 ◽  
Author(s):  
Francisco E. Nicolás-Molina ◽  
Eusebio Navarro ◽  
Rosa M. Ruiz-Vázquez

2021 ◽  
Vol 12 ◽  
Author(s):  
Yuxiao Xie ◽  
Shulin Chen ◽  
Xiaochao Xiong

Zeaxanthin is vital to human health; thus, its production has received much attention, and it is also an essential precursor for the biosynthesis of other critical carotenoids such as astaxanthin and crocetin. Yarrowia lipolytica is one of the most intensively studied non-conventional yeasts and has been genetically engineered as a cell factory to produce carotenoids such as lycopene and β-carotene. However, zeaxanthin production by Y. lipolytica has not been well investigated. To fill this gap, β-carotene biosynthesis pathway has been first constructed in this study by the expression of genes, including crtE, crtB, crtI, and carRP. Three crtZ genes encoding β-carotene hydroxylase from different organisms were individually introduced into β-carotene-producing Y. lipolytica to evaluate their performance for producing zeaxanthin. The expression of crtZ from the bacterium Pantoea ananatis (formerly Erwinia uredovora, Eu-crtZ) resulted in the highest zeaxanthin titer and content on the basis of dry cell weight (DCW). After verifying the function of Eu-crtZ for producing zeaxanthin, the high-copy-number integration into the ribosomal DNA of Y. lipolytica led to a 4.02-fold increase in the titer of zeaxanthin and a 721% increase in the content of zeaxanthin. The highest zeaxanthin titer achieved 21.98 ± 1.80 mg/L by the strain grown on a yeast extract peptone dextrose (YPD)–rich medium. In contrast, the highest content of DCW reached 3.20 ± 0.11 mg/g using a synthetic yeast nitrogen base (YNB) medium to culture the cells. Over 18.0 g/L of citric acid was detected in the supernatant of the YPD medium at the end of cultivation. Furthermore, the zeaxanthin-producing strains still accumulated a large amount of lycopene and β-carotene. The results demonstrated the potential of a cell factory for zeaxanthin biosynthesis and opened up an avenue to engineer this host for the overproduction of carotenoids.


2017 ◽  
Vol 66 (3) ◽  
pp. 335-343 ◽  
Author(s):  
Monika Kordowska-Wiater ◽  
Adam Kuzdraliński ◽  
Tomasz Czernecki ◽  
Zdzisław Targoński ◽  
Magdalena Frąc ◽  
...  

Arabitol is a polyalcohol which has about 70% of the sweetness of sucrose and an energy density of 0.2 kcal/g. Similarly to xylitol, it can be used in the food and pharmaceutical industries as a natural sweetener, a texturing agent, a dental caries reducer, and a humectant. Biotechnological production of arabitol from sugars represents an interesting alternative to chemical production. The yeast Scheffersomyces shehatae strain 20BM-3 isolated from rotten wood was screened for its ability to produce arabitol from L-arabinose, glucose, and xylose. This isolate, cultured at 28°C and 150 rpm, secreted 4.03 ± 0.00 to 7.97 ± 0.67 g/l of arabitol from 17–30 g/l of L-arabinose assimilated from a medium containing 20–80 g/l of this pentose with yields of 0.24 ± 0.00 to 0.36 ± 0.02 g/g. An optimization study demonstrated that pH 4.0, 32°C, and a shaking frequency of 150 rpm were the optimum conditions for arabitol production by the investigated strain. Under these conditions, strain 20BM-3 produced 6.2 ± 0.17 g/l of arabitol from 17.5 g/l of arabinose after 4 days with a yield of 0.35 ± 0.01 g/g. This strain also produced arabitol from glucose, giving much lower yields, but did not produce it from xylose. The new strain can be successfully used for arabitol production from abundantly available sugars found in plant biomass.


Marine Drugs ◽  
2019 ◽  
Vol 17 (12) ◽  
pp. 696
Author(s):  
Danqiong Huang ◽  
Wenfu Liu ◽  
Anguo Li ◽  
Chaogang Wang ◽  
Zhangli Hu

Haematococcus pluvialis is widely distributed in the world and well known as the richest natural source of astaxanthin that is a strong antioxidant with excellent commercial value. The pathway of astaxanthin biosynthesis in H. pluvialis has been documented as an enzymatic reaction. Several enzymes have been reported, but their isoforms or homologs have not been investigated genome-wide. To better understand the astaxanthin biosynthesis pathway in H. pluvialis, eight candidates of the geranylgeranyl pyrophosphate synthase gene (HpGGPPS) predicted from Iso-seq data were isolated in this study. The length of coding region of these candidates varied from 960 bp to 1272 bp, composing of 7–9 exons. The putative amino acids of all candidates composed the signature domain of GGPPS gene. However, the motifs in the domain region are varied, indicating different bio-functions. Phylogenetic analysis revealed eight candidates can be clustered into three groups. Only two candidates in Group1 encode the synthase participating in the astaxanthin formation. The yield of astaxanthin from these two candidates, 7.1 mg/g (DW) and 6.5 mg/g (DW) respectively, is significant higher than that from CrtE (2.4 mg/g DW), a GGPPS gene from Pantoea ananatis. This study provides a potential productive pathway for astaxanthin synthesis.


2020 ◽  
Vol 8 (10) ◽  
pp. 789 ◽  
Author(s):  
Samuel Jannel ◽  
Yanis Caro ◽  
Marc Bermudes ◽  
Thomas Petit

Astaxanthin shows many biological activities. It has acquired a high economic potential and its current market is dominated by its synthetic form. However, due to the increase of the health and environmental concerns from consumers, natural forms are now preferred for human consumption. Haematococcus pluvialis is artificially cultured at an industrial scale to produce astaxanthin used as a dietary supplement. However, due to the high cost of its cultivation and its relatively low biomass and pigment productivities, the astaxanthin extracted from this microalga remains expensive and this has probably the consequence of slowing down its economic development in the lower added-value market such as food ingredient. In this review, we first aim to provide an overview of the chemical and biochemical properties of astaxanthin, as well as of its natural sources. We discuss its bioavailability, metabolism, and biological activities. We present a state-of-the-art of the biology and physiology of H. pluvialis, and highlight novel insights into the biotechnological processes which allow optimizing the biomass and astaxanthin productivities. We are trying to identify some lines of research that would improve the industrial sustainability and economic viability of this bio-production and to broaden the commercial potential of astaxanthin produced from H. pluvialis.


2003 ◽  
Vol 69 (4) ◽  
pp. 2110-2115 ◽  
Author(s):  
Ziye Liu ◽  
Yuquan Lu ◽  
Jianbo Zhang ◽  
Keith Pardee ◽  
Peng George Wang

ABSTRACT The frequency of Escherichia coli infection has lead to concerns over pathogenic bacteria in our food supply and a demand for therapeutics. Glycolipids on gut cells serve as receptors for the Shiga-like toxin produced by E. coli. Oligosaccharide moiety analogues of these glycolipids can compete with receptors for the toxin, thus acting as antibacterials. An enzymatic synthesis of the P1 trisaccharide (Galα1,4Galβ1,4GlcNAc), one of the oligosaccharide analogues, was assessed in this study. In the proposed synthetic pathway, UDP-glucose was generated from sucrose with an Anabaena sp. sucrose synthase and then converted with an E. coli UDP-glucose 4-epimerase to UDP-galactose. Two molecules of galactose were linked to N-acetylglucosamine subsequently with a Helicobacter pylori β-l,4-galactosyltransferase and a Neisseria meningitidis α-1,4-galactosyltransferase to produce one molecule of P1 trisaccharide. The four enzymes were coexpressed in a single genetically engineered E. coli strain that was then permeabilized and used to catalyze the enzymatic reaction. P1 trisaccharide was accumulated up to 50 mM (5.4 g in a 200-ml reaction volume), with a 67% yield based on the consumption of N-acetylglucosamine. This study provides an efficient approach for the preparative-scale synthesis of P1 trisaccharide with recombinant bacteria.


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