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Qipeng Yuan - One of the best experts on this subject based on the ideXlab platform.

  • improved β carotene production by oxidative stress in Blakeslea trispora induced by liquid paraffin
    Biotechnology Letters, 2013
    Co-Authors: Pingwah Tang, Qipeng Yuan
    Abstract:

    When 3 % (v/v) liquid paraffin was added to the medium, β-carotene production increased from 397 to 715 mg l−1 in mated cultures of Blakeslea trispora. Liquid paraffin also enhanced the oxygen concentration and induce high oxidative stress, as observed by the increase in activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD). After 84 h of cultivation in the presence of liquid paraffin, the activities of SOD, CAT and POD in B. trispora increased 77, 52.5 and 76.6 %, respectively.

  • trisporic acid stimulates gene transcription of terpenoid biosynthesis in Blakeslea trispora
    Process Biochemistry, 2012
    Co-Authors: Jie Sun, Xinxiao Sun, Qipeng Yuan
    Abstract:

    Abstract The zygomycete Blakeslea trispora is used commercially to produce β-carotene. Trisporic acid (TA), the previously discovered pheromone of B. trispora , is considered to be the main inducer of carotene biosynthesis. To gain insight into the regulatory mechanisms of TA that controls terpenoid biosynthesis, changes in the contents of β-carotene, ubiquinone, and ergosterol in the (−) strain of B. trispora after TA addition were measured. Transcription products of eight genes encoding enzymes in terpenoid biosynthesis were also analyzed. The addition of TA to the B. trispora culture increased the production of β-carotene and ubiquinone, while the ergosterol content remained unchanged during the first 48 h after TA addition and decreased slightly thereafter. Four genes in the β-carotene biosynthetic pathway ( ipi , carG , carRA , and carB ) had increased expression following TA addition. These data suggest that TA increases terpenoid production in B. trispora by stimulation of transcription. This study contributes to a better understanding of the regulatory mechanisms of TA on terpenoid biosynthesis.

  • Improved β-carotene biosynthesis and gene transcription in Blakeslea trispora with arachidonic acid.
    Biotechnology letters, 2012
    Co-Authors: Jie Sun, Qipeng Yuan
    Abstract:

    With 0.4 g l−1 arachidonic acid (AA) added to the medium after 36 h fermentation, β-carotene production in mated cultures of Blakeslea trispora was 73 % higher than that of the control at 690 mg l−1. With the treatment of AA, the transcriptional levels of genes hmgR, carRA and carB, that are involved in carotene biosynthesis, increased by 31, 22 and 39 %, respectively.

  • Improved lycopene production by Blakeslea trispora with isopentenyl compounds and metabolic precursors.
    Biotechnology letters, 2011
    Co-Authors: Yan-qiu Shi, Xiu-lan Xin, Qipeng Yuan
    Abstract:

    The highest lycopene production in mated cultures of Blakeslea trispora was 578 mg/l by adding 42 mg geraniol/l to the medium after 48 h of growth. The control gave 317 mg/l. Adding isopentenyl alcohol at 40 mg/l, mevalonic acid at 17.5 mg/l or dimethyl allyl alcohol at 150 mg, each after 36 h growth, gave lycopene yields 62, 45 and 47%, respectively, higher than the control.

  • An improved RNA isolation method for filamentous fungus Blakeslea trispora rich in polysaccharides.
    Applied biochemistry and biotechnology, 2008
    Co-Authors: Wenya Wang, Qipeng Yuan
    Abstract:

    Isolation and purification of biologically active RNA from filamentous fungi is difficult because of the complex cell wall and the high level of polysaccharides which bind to or co-precipitate with RNA. Using benzyl chloride and guanidine thiocyanate, RNA was successfully isolated from Blakeslea trispora in which other RNA extraction methods and commercially available kits failed to deliver suitable results. The RNA isolated by this procedure appears to be relatively pure, as it has a ratio of absorbance at 260/280 nm of 1.8-1.9. The integrity of the RNA was further substantiated by RT-PCR and Northern hybridization, respectively. This procedure should be useful for isolating RNA from other filamentous fungi and, therefore, will serve as an important tool for the molecular analysis of these organisms.

E. P. Feofilova - One of the best experts on this subject based on the ideXlab platform.

  • Lipid composition of the mucoraceous fungus Blakeslea trispora under lycopene formation-stimulating conditions
    Microbiology, 2010
    Co-Authors: V. M. Tereshina, A. S. Memorskaya, E. P. Feofilova
    Abstract:

    Stimulation of lycopene synthesis in the mycelium of the mucoraceous fungus Blakeslea trispora was accompanied by major changes in its lipid composition. The phospholipid content in the membrane lip-ids doubled, whereas the sterol and sphingolipid levels changed insignificantly. The amounts of phosphatidyl-choline, phosphatidylethanolamine, and phosphatidic acid in the phospholipids and the triacylglycerol content in the acylglycerols increased. The desaturation degree of fatty acids drastically increased against the background of a decrease in that of the neutral lipids. The data obtained are discussed in relation to the mechanism of action of the lycopene formation stimulator.

  • Biochemical Mechanisms of Temperature Adaptation in the (+) and (-) Strains of Blakeslea trispora
    Microbiology, 2005
    Co-Authors: E. P. Feofilova, V. M. Tereshina, A. S. Memorskaya
    Abstract:

    Evidence obtained with industrial β-carotene-superproducing (+)T and (-)T strains, which fail to form zygotes, suggests that the lipids in the mycelium of the (-) strain of Blakeslea trispora lack linolenic acid. This circumstance apparently accounts for the fact that the (+) and (-) strains of B. trispora use different adaptive mechanisms to cope with an increase or decrease in cultivation temperature. In the (+) strain, temperature adaptation is based on changes in the ratio between linoleic and linolenic acyls and, also, involves shortening of acyl chains. In addition, the (+) strain contains a larger amount of protective carbohydrates, such as arabitol and trehalose. This strain is characterized by the presence of glycerol, a cryothermoprotector that protects fungal cells at low temperatures. The (-) strain lacks these biochemical mechanisms, but its neutral lipids contain a comparatively high amount of sterols and their esters. These facts enable us to interpret the enhanced thermotolerance of the (-) strain and its capacity to grow at high temperatures in terms of biochemical adaptation. In the light of the data obtained with wild-type and industrial strains, it is suggested that the lack of linolenic acid in the lipids should be considered an essential sex-specific property of the heterothallic strains of Blakeslea trispora .

  • biochemical mechanisms of temperature adaptation in the and strains of Blakeslea trispora
    Microbiology, 2005
    Co-Authors: E. P. Feofilova, V. M. Tereshina, A. S. Memorskaya
    Abstract:

    Evidence obtained with industrial β-carotene-superproducing (+)T and (-)T strains, which fail to form zygotes, suggests that the lipids in the mycelium of the (-) strain of Blakeslea trispora lack linolenic acid. This circumstance apparently accounts for the fact that the (+) and (-) strains of B. trispora use different adaptive mechanisms to cope with an increase or decrease in cultivation temperature. In the (+) strain, temperature adaptation is based on changes in the ratio between linoleic and linolenic acyls and, also, involves shortening of acyl chains. In addition, the (+) strain contains a larger amount of protective carbohydrates, such as arabitol and trehalose. This strain is characterized by the presence of glycerol, a cryothermoprotector that protects fungal cells at low temperatures. The (-) strain lacks these biochemical mechanisms, but its neutral lipids contain a comparatively high amount of sterols and their esters. These facts enable us to interpret the enhanced thermotolerance of the (-) strain and its capacity to grow at high temperatures in terms of biochemical adaptation. In the light of the data obtained with wild-type and industrial strains, it is suggested that the lack of linolenic acid in the lipids should be considered an essential sex-specific property of the heterothallic strains of Blakeslea trispora.

  • Biochemical mechanisms of temperature adaptation in the (+) and (-) strains of Blakeslea trispora
    Mikrobiologiia, 2005
    Co-Authors: E. P. Feofilova, V. M. Tereshina, A S Memorskaia
    Abstract:

    Evidence obtained with industrial beta-carotene-superproducing (+)T and (-)T strains, which fail to form zygotes, suggests that the lipids in the mycelium of the (-) strain of Blakeslea trispora lack linolenic acid. This circumstance apparently accounts for the fact that the (+) and (-) strains of B. trispora use different adaptive mechanisms to cope with an increase or decrease in cultivation temperature. In the (+) strain, temperature adaptation is based on changes in the ratio between linoleic and linolenic acyls and, also, involves shortening of acyl chains. In addition, the (+) strain contains a larger amount of protective carbohydrates, such as arabitol and trehalose. This strain is characterized by the presence of glycerol, a cryothermoprotector that protects fungal cells at low temperatures. The (-) strain lacks these biochemical mechanisms, but its neutral lipids contain a comparatively high amount of sterols and their esters. These facts enable us to interpret the enhanced thermotolerance of the (-) strain and its capacity to grow at high temperatures in terms of biochemical adaptation. In the light of the data obtained with wild-type and industrial strains, it is suggested that the lack of linolenic acid in the lipids should be considered an essential sex-specific property of the heterothallic strains of Blakeslea trispora.

  • Lipid composition of cells of heterothallic strains in the developmental cycle of Blakeslea trispora
    Prikladnaia biokhimiia i mikrobiologiia, 2005
    Co-Authors: V. M. Tereshina, A S Memorskaia, E. P. Feofilova
    Abstract:

    Lipid compositions in mycelium and spores of Blakeslea trispora heterothallic strains were studied. Distinctions between the strains in the ability to synthesize linolenic acid and in optimal growth temperature were demonstrated. The (-) strain grew at a higher temperature and was unable to synthesize linolenic acid, whereas the (+) strain accumulated this acid up to 20% of total fatty acids. The distinctions between the strains remained at different developmental stages (mycelium and spores). A higher thermophilicity of the (-) strain correlated with a high sterol content, which is typical of thermophilic fungi. The lipid compositions of heterothallic strains studied differed in lipid content, their fractional composition, the degree of unsaturation, and carotenoid composition.

Xiaoyan Huang - One of the best experts on this subject based on the ideXlab platform.

  • oxidative stress response of Blakeslea trispora induced by h2o2 during β carotene biosynthesis
    Journal of Industrial Microbiology & Biotechnology, 2014
    Co-Authors: Hong-bo Wang, Jun Luo, Xiaoyan Huang
    Abstract:

    The cellular response of Blakeslea trispora to oxidative stress induced by H2O2 in shake flask culture was investigated in this study. A mild oxidative stress was created by adding 40 μm of H2O2 into the medium after 3 days of the fermentation. The production of β-carotene increased nearly 38 % after a 6-day culture. Under the oxidative stress induced by H2O2, the expressions of hmgr, ipi, carG, carRA, and carB involving the β-carotene biosynthetic pathway all increased in 3 h. The aerobic metabolism of glucose remarkably accelerated within 24 h. In addition, the specific activities of superoxide dismutase and catalase were significantly increased. These changes of B. trispora were responses for reducing cell injury, and the reasons for increasing β-carotene production caused by H2O2.

Yan Zhu - One of the best experts on this subject based on the ideXlab platform.

  • Improved production of lycopene and β-carotene by Blakeslea trispora with oxygen-vectors
    Process Biochemistry, 2007
    Co-Authors: Qipeng Yuan, Yan Zhu
    Abstract:

    Abstract Lycopene and β-carotene production were increased when oxygen-vectors, n-hexane and n-dodecane, were added to cultures of Blakeslea trispora because of the enhanced dissolved oxygen concentrations. With 1% (v/v) n-hexane or n-dodecane added in the medium, lycopene production was 51% or 78% higher and β-carotene production was 44% or 65% higher than that of the control, respectively. The highest lycopene and β-carotene production, 533 mg l−1and 596 mg l−1, were obtained when 1% (v/v) n-dodecane and 0.1% (w/v) Span 20 were added together, which were 2.1-fold and 1.8-fold of the control, respectively.

V. M. Tereshina - One of the best experts on this subject based on the ideXlab platform.

  • Trisporoids and carotenoids in Blakeslea trispora strains differing in capacity for zygote formation
    Microbiology, 2012
    Co-Authors: O. A. Vereshchagina, A. S. Memorskaya, G. A. Kochkina, V. M. Tereshina
    Abstract:

    The study of sexual interaction in seven (+) and four (−) Blakeslea trispora strains from the All-Russian Collection of Microorganisms showed that all the strains were capable of forming zygotes, albeit to a varying degree. Thus, pairs of strains with active zygote formation and not forming zygospores were identified. It was established that, irrespective of their capacity for zygote formation, all pairs of the (+) and (−) strains synthesized trisporoids in submerged culture. However, zygote-forming pairs accumulated significantly more trisporoids and carotenoids than the strain pairs incapable of forming zygospores. As a result, positive correlation between the capacity for zygote formation in surface culture and trisporoid and carotenoid synthesis in submerged culture was revealed in wild strains.

  • Trisporoids under the stimulation of carotenogenesis in Blakeslea trispora
    Microbiology, 2012
    Co-Authors: O. A. Vereshchagina, A. S. Memorskaya, V. M. Tereshina
    Abstract:

    The patterns of trisporoid synthesis in joint cultivation of Blakeslea trispora mates have been studied. The pair of the not-zygospore-forming carotenoid overproducer strains T(+) and T(−) was found to synthesize a large amount of trisporoids, which did not differ in biological activity from those in the wild type strains. While the β-carotene synthesis stimulator β-ionone increased the amount of trisporoids, the share of trisporic acids in their composition decreased considerably. The lycopene synthesis stimulator 2-amino-6-methylpyridine caused a decrease in the content of trisporoid which had no trisporic acids in their composition. Emergence of a new substance with the maximum absorption at 250 nm, which accounted for up to 45% of the sum of trisporoids, was a general regularity in the action of both stimulators. The combined action of these two effectors resulted in additional stimulation of lycopene synthesis and was accompanied by the disappearance of trisporic acids. The aggregate findings indicate that both carotenogenesis stimulators inhibit the synthesis of trisporic acids, i.e., their action is not mediated by stimulation of trisporoid synthesis.

  • Lipid composition of the mucoraceous fungus Blakeslea trispora under lycopene formation-stimulating conditions
    Microbiology, 2010
    Co-Authors: V. M. Tereshina, A. S. Memorskaya, E. P. Feofilova
    Abstract:

    Stimulation of lycopene synthesis in the mycelium of the mucoraceous fungus Blakeslea trispora was accompanied by major changes in its lipid composition. The phospholipid content in the membrane lip-ids doubled, whereas the sterol and sphingolipid levels changed insignificantly. The amounts of phosphatidyl-choline, phosphatidylethanolamine, and phosphatidic acid in the phospholipids and the triacylglycerol content in the acylglycerols increased. The desaturation degree of fatty acids drastically increased against the background of a decrease in that of the neutral lipids. The data obtained are discussed in relation to the mechanism of action of the lycopene formation stimulator.

  • Biochemical Mechanisms of Temperature Adaptation in the (+) and (-) Strains of Blakeslea trispora
    Microbiology, 2005
    Co-Authors: E. P. Feofilova, V. M. Tereshina, A. S. Memorskaya
    Abstract:

    Evidence obtained with industrial β-carotene-superproducing (+)T and (-)T strains, which fail to form zygotes, suggests that the lipids in the mycelium of the (-) strain of Blakeslea trispora lack linolenic acid. This circumstance apparently accounts for the fact that the (+) and (-) strains of B. trispora use different adaptive mechanisms to cope with an increase or decrease in cultivation temperature. In the (+) strain, temperature adaptation is based on changes in the ratio between linoleic and linolenic acyls and, also, involves shortening of acyl chains. In addition, the (+) strain contains a larger amount of protective carbohydrates, such as arabitol and trehalose. This strain is characterized by the presence of glycerol, a cryothermoprotector that protects fungal cells at low temperatures. The (-) strain lacks these biochemical mechanisms, but its neutral lipids contain a comparatively high amount of sterols and their esters. These facts enable us to interpret the enhanced thermotolerance of the (-) strain and its capacity to grow at high temperatures in terms of biochemical adaptation. In the light of the data obtained with wild-type and industrial strains, it is suggested that the lack of linolenic acid in the lipids should be considered an essential sex-specific property of the heterothallic strains of Blakeslea trispora .

  • biochemical mechanisms of temperature adaptation in the and strains of Blakeslea trispora
    Microbiology, 2005
    Co-Authors: E. P. Feofilova, V. M. Tereshina, A. S. Memorskaya
    Abstract:

    Evidence obtained with industrial β-carotene-superproducing (+)T and (-)T strains, which fail to form zygotes, suggests that the lipids in the mycelium of the (-) strain of Blakeslea trispora lack linolenic acid. This circumstance apparently accounts for the fact that the (+) and (-) strains of B. trispora use different adaptive mechanisms to cope with an increase or decrease in cultivation temperature. In the (+) strain, temperature adaptation is based on changes in the ratio between linoleic and linolenic acyls and, also, involves shortening of acyl chains. In addition, the (+) strain contains a larger amount of protective carbohydrates, such as arabitol and trehalose. This strain is characterized by the presence of glycerol, a cryothermoprotector that protects fungal cells at low temperatures. The (-) strain lacks these biochemical mechanisms, but its neutral lipids contain a comparatively high amount of sterols and their esters. These facts enable us to interpret the enhanced thermotolerance of the (-) strain and its capacity to grow at high temperatures in terms of biochemical adaptation. In the light of the data obtained with wild-type and industrial strains, it is suggested that the lack of linolenic acid in the lipids should be considered an essential sex-specific property of the heterothallic strains of Blakeslea trispora.