scholarly journals Studies in carotenogenesis. 1. General conditions governing β-carotene synthesis by the fungus Phycomyces blakesleeanus Burgeff

1951 ◽  
Vol 48 (2) ◽  
pp. 154-163 ◽  
Author(s):  
G. A. Garton ◽  
T. W. Goodwin ◽  
W. Lijinsky
Genetics ◽  
2001 ◽  
Vol 158 (2) ◽  
pp. 635-641
Author(s):  
Bina J Mehta ◽  
Enrique Cerdá-Olmedo

Abstract Sexual interaction between strains of opposite sex in many fungi of the order Mucorales modifies hyphal morphology and increases the carotene content. The progeny of crosses of Phycomyces blakesleeanus usually include a small proportion of anomalous segregants that show these signs of sexual stimulation without a partner. We have analyzed the genetic constitution of such segregants from crosses that involved a carF mutation for overaccumulation of β-carotene and other markers. The new strains were diploids or partial diploids heterozygous for the sex markers. Diploidy was unknown in this fungus and in the Zygomycetes. Random chromosome losses during the vegetative growth of the diploid led to heterokaryosis in the coenocytic mycelia and eventually to sectors of various tints and mating behavior. The changes in the nuclear composition of the mycelia could be followed by selecting for individual nuclei. The results impose a reinterpretation of the sexual cycle of Phycomyces. Some of the intersexual strains that carried the carF mutation contained 25 mg β-carotene per gram of dry mass and were sufficiently stable for practical use in carotene production.


2003 ◽  
Vol 58 (3-4) ◽  
pp. 225-229 ◽  
Author(s):  
Emilina D. Simova ◽  
Ginka I. Frengova ◽  
Dora M. Beshkova

Under intensive aeration (1.3 l/l min) the associated growth of Rhodotorula rubra GED2 and Lactobacillus casei subsp. casei in cheese whey ultrafiltrate (55 g lactose/l) proceeded effectively for both cultures with production of maximum carotenoids (12.4 mg/l culture fluid). For maximum amount of carotenoids synthesized in the cell, the yeast required more intensive aeration than the aeration needed for synthesis of maximum concentration of dry cells. Maximum concentration of carotenoids in the cell (0.49 mg/g dry cells) was registered with air flow rate at 1.3 l/l min, and of dry cells (27.0 g/l) at 1.0 l/l min. An important characteristic of carotenogenesis by Rhodotorula rubra GED2 + Lactobacillus casei subsp. casei was established - the intensive aeration (above 1.0 l/l min) stimulated β-carotene synthesis (60% of total carotenoids).


Mycologia ◽  
1958 ◽  
Vol 50 (6) ◽  
pp. 862-873
Author(s):  
Virgil Greene Lilly ◽  
H. L. Barnett ◽  
R. F. Krause ◽  
F. J. Lotspeich

1984 ◽  
Vol 39 (5) ◽  
pp. 460-463 ◽  
Author(s):  
Peter M. Bramley ◽  
Ian E. Clarke ◽  
Gerhard Sandmann ◽  
Peter Böger

Cell extracts of the C115 (β-carotene-accumulating) strain of Phycomyces blakesleeanus were incubated with either [2-14C]MVA or [1-14C]IPP and a range of possible inhibitors of carotenogenesis, including bleaching herbicides, biphenyl compounds and geranylacetone. Several of these compounds were potent inhibitors of β-carotene formation and caused the accumulation of phytoene. No other carotenes were found to accumulate, in vitro.The structures of these inhibitors, compared to that of phytoene, suggest that they affect the enzymic activity of “phytoene dehydrogenase”, possibly by competitive inhibition.


1957 ◽  
Vol 12 (6) ◽  
pp. 401-407 ◽  
Author(s):  
Hedwig Claes

One of the recently described mutant strains of chlorella (strain 5/520) accumulates -in the dark phytoene, phytofluene, ζ-carotene, protetrahydrolycopene and prolycopene and forms α- and β-carotene, xanthophylls and appreciable amounts of chlorophyll in light only 1, 2.The experiments described below indicate that1. O2 and light are indispensable for xanthophyll and appreciable chlorophyll synthesis. Both syntheses appear to be linked somehow.2. Carotene synthesis depends upon light but not on O2 and is not linked to xanthophyll synthesis.3. Carotenoid synthesis in light is always accompanied by a decrease of polyenes of the Porter-Lincoln sequence, which have been accumulated in the cells during previous cultivation in the dark. Evidence seems strong that these polyenes are direct precursors of the normal carotenoids.4. An as yet unidentified carotene is formed in appreciable amounts along with the normal carotenes in the light, probably as byproduct, not a precursor.


PLoS ONE ◽  
2014 ◽  
Vol 9 (6) ◽  
pp. e100212 ◽  
Author(s):  
Karabi Datta ◽  
Gayetri Sahoo ◽  
Sellappan Krishnan ◽  
Moumita Ganguly ◽  
Swapan K. Datta

2020 ◽  
Author(s):  
Fan Yang ◽  
Liang Liu ◽  
Shan Qiang ◽  
Ching Yuan Hu ◽  
Ying Li ◽  
...  

Abstract 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.


1963 ◽  
Vol 11 (2) ◽  
pp. 128-131
Author(s):  
Alex Ciegler ◽  
George E. N. Nelson ◽  
Harlow H. Hall

1963 ◽  
Vol 11 (2) ◽  
pp. 128-131 ◽  
Author(s):  
Alex Ciegler ◽  
George E. N. Nelson ◽  
Harlow H. Hall

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