Relationship between β-Carotene Accumulation and Geranylgeranyl Pyrophosphate Synthase in Different Species of Dunaliella

To study the relationship between β-carotene synthesis and geranylgeranyl pyrophosphate synthase (GGPS) activity, 15 species of Dunaliella were used to determine the changes in photosynthetic pigment contents, chlorophyll fluorescence parameters, β-carotene content, and GGPS activity. By observing the morphology and size of 15 species of Dunaliella, D8 has the largest individual algal cell and D9 has the smallest individual. Growth was relatively slow during days one through seven. After about eight days, the cells entered the logarithmic growth period and grew rapidly to a high density. After about 45 days, they entered a mature period, and growth slowed down. The contents of chlorophyll, carotenoids, and β-carotene increased during growth. D1 has the highest accumulation of β-carotene, and GGPS enzyme activity has a positive linear relationship with the β-carotene synthesis content. Phylogenetic analysis showed that the GGPS proteins of the 15 species were highly homologous, and the GGPS protein was not part of the membrane.

Identification and analyses of the chemical composition of a naturally occurring albino mutant chanterelle

White chanterelles (Basidiomycota), lacking the orange pigments and apricot-like odour of typical chanterelles, were found recently in the Canadian provinces of Québec (QC) and Newfoundland & Labrador (NL). Our phylogenetic analyses confirmed the identification of all white chanterelles from NL and QC as Cantharellus enelensis; we name these forma acolodorus. We characterized carotenoid pigments, lipids, phenolics, and volatile compounds in these and related chanterelles. White mutants of C. enelensis lacked detectable β-carotene, confirmed to be the primary pigment of wild-type, golden-orange individuals, and could also be distinguished by their profiles of fatty acids and phenolic acids, and by the ketone and terpene composition of their volatiles. We detected single base substitutions in the phytoene desaturase (Al-1) and phytoene synthase (Al-2) genes of the white mutant, which are predicted to result in altered amino acids in their gene products and may be responsible for the loss of β-carotene synthesis in that form.

Identity and Chemical Composition of an Albino Mutant Chanterelle

White chanterelles (Basidiomycota), lacking the orange pigments and apricot-like odour of typical chanterelles, were found recently in the Canadian provinces of Québec (QC) and Newfoundland & Labrador (NL). Phylogenetic analyses confirmed all samples of white chanterelles from NL and QC as Cantharellus enelensis; we name these forma acolodorus. We characterized carotenoid pigments, lipids, phenolics, and volatile compounds in these and related chanterelles. White mutants of C. enelensis lacked detectable β-carotene, confirmed to be the primary pigment of wild-type, golden-orange individuals, and could also be distinguished by their profiles of fatty acids and phenolic acids, and by the ketone and terpene composition of their volatiles. We detected single base substitutions in the phytoene desaturase (Al-1) and phytoene synthase (Al-2) genes of the white mutant, which are predicted to result in altered amino acids in their gene products and may be responsible for the loss of β-carotene synthesis in that form.

Natural β-Carotene Production by Blakeslea trispora Cultivated in Spanish-Style Green Olive Processing Wastewaters

In the current research, the potential of Spanish-style green olive processing wastewaters (lye and washing waters) exploitation toward natural β-carotene production by Blakeslea trispora was tested for the first time. Mating culture generated by the joint cultivation of the heterothallic fungal strains ATCC 14271 and 14272 in the non-sterile lye and washing waters was able to grow, achieving the phytotoxic hydroxytyrosol degradation by 57.3% and 66.8%, respectively. However, the low sugar and nitrogen content of the streams did not favor carotenogenesis. Alternatively, in the nutrient-enriched effluents, a notable quantity of β-carotene was produced, accounted for 61.2 mg/L (lye) and 64.1 mg/L (washing waters) (82–88% of total carotenoid content). Above all, enriched streams had a noteworthy stimulating effect on the β-carotene synthesis, because both the maximum β-carotene yield per volume of enriched effluents and specific β-carotene production rate were higher when compared with the respective values obtained from trials with synthetic reference medium without added effluents. Hydroxytyrosol and tyrosol showed high stability during the non-sterile process for β-carotene production by B. trispora grown in the enriched effluents. This finding strengthens the potential toward the generation of multiple high-value products, which could lower the natural β-carotene production costs.

Enhanced β-carotene production by promoting the multivesicular body (MVB) pathway in Yarrowia lipolytica

Background: β-carotene is a precursor of vitamin A and has great commercial value as an additive in foods and feeds. Many pathways not directly related to the β-carotene synthesis affect β-carotene production since the interactions among metabolic fluxes of cells confer a complex regulatory network. Engineered Y. lipolytica strain has excellent potential for β-carotene production as oleaginous yeast. Optimizing indirectly metabolic pathways in Y. lipolytica may offer a new strategy for making the β-carotene production achieve a commercially viable yield.Results: In this study, we found that the proper promotion of the multivesicular body (MVB) sorting pathway elevated the production of β-carotene by 1.58 fold when overexpressing one copy of the Did2 gene in Y. lipolytica. Through the measurement of ATP, NADPH, the mRNA, and protein level of key genes in the β-carotene synthesis pathway, the reason for β-carotene elevated was deuced that the protein level of the key enzymes (tHMG and CarA) was increased. When overexpressing two copies of the Did2 gene, the transcription level of the key genes was all elevated. However, the protein level of key enzymes in the β-carotene synthesis pathway was reduced compared with the overexpressing one copy of the Did2 gene, which resulted in reduced β-carotene content.Conclusion: This study suggests that the MVB sorting pathway is not responsible for sorting protein but has a crucial regulating effect on protein abundance in cells. Engineering the MVB sorting pathway could potentially increase the production of other high-value products. Moreover, manipulation of indirectly related metabolic pathways also is a critical strategy in synthetic biology research.

A Metagenomics Analysis on B-Carotene Synthesis in Neurospora Crassa

We have studied insilico on evolutionary uniqueness of phytoene synthase, which is one of the regulatory enzymes of ?-carotene synthesis in Neurospora crassa. This study reveals multiple sequence alignments showed high sequences with similarity within a species of bacteria, fungi and higher plants. This results designate interestingly between species of bacteria-fungi, fungi-plant, and among the species of bacteria-fungi-plant, showed tremendously less sequence with similarity, except bacteria-plant (high sequence with similarity) respectively. In Phylogenetics tree analysis showed within species of bacteria, fungi and plant 91%, 92% and 99% homology. Whereas in between species of bacteria-fungi, bacteria-plant, fungi-plant, and among the species bacteria-fungi-plant showed 99%, 96%, 100%, and 91%-99% homology respectively. N. crassa phytoene synthase enzyme encode (Isoprenoid Biosynthesis enzymes, Class 1) protein size 610aa, Cyanobacteria phytoene encode (Isoprenoid Biosynthesis enzymes, Class 1) protein size 310aa, and Oryza sativa Indica phytoene synthase 1 (chloroplast), (Isoprenoid Biosynthesis enzymes, Class 1) encode protein size 421aa (e- value 0.0, 0.0 and 0.0; identity 100%, 100% and 100%; Max.score:1238, 644 and 870) respectively. We studied insilico on basis of an evolutionary Endosymbiotic theory; a bacterium is the ancestors to eukaryotes. Int J Appl Sci Biotechnol, Vol 3(3): 490-503

Metabolic regulation of α-linolenic acid on β-carotene synthesis in Blakeslea trispora revealed by a GC-MS-based metabolomic approach

ALA promoted β-carotene production in two ways: increasing the dissolved oxygen and decreasing the consumption of acetyl-CoA.