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Feng Chen - One of the best experts on this subject based on the ideXlab platform.

  • Article Mutation Breeding of Extracellular Polysaccharide-Producing Microalga Crypthecodinium cohnii by a Novel Mutagenesis with Atmospheric and Room Temperature Plasma
    2015
    Co-Authors: Bin Liu, Yue Jiang, Zheng Sun, Bo Yang, Dong Wei, Feng Chen
    Abstract:

    Abstract: Extracellular polysaccharides (EPS) produced by marine microalgae have the potential to be used as antioxidants, antiviral agents, immunomodulators, and anti-inflammatory agents. Although the marine microalga Crypthecodinium cohnii releases EPS during the process of docosahexaenoic acid (DHA) production, the yield of EPS remains relatively low. To improve the EPS production, a novel mutagenesis of C. cohnii was conducted by atmospheric and room temperature plasma (ARTP). Of the 12 mutants obtained, 10 mutants exhibited significantly enhanced EPS yield on biomass as compared with the wild type strain. Among them, mutant M7 was the best as it could produce an EPS volumetric yield of 1.02 g/L, EPS yield on biomass of 0.39 g/g and EPS yield on glucose of 94 mg/g, which were 33.85%, 85.35 % and 57.17 % higher than that of the wild typ

  • Sesamol Enhances Cell Growth and the Biosynthesis and Accumulation of Docosahexaenoic Acid in the Microalga Crypthecodinium cohnii
    Journal of agricultural and food chemistry, 2015
    Co-Authors: Bin Liu, Yue Jiang, Jin Liu, Peipei Sun, Feng Chen
    Abstract:

    Sesamol is a strong antioxidant phenolic compound found in sesame seed. It possesses the ability to scavenge intracellular reactive oxygen species (ROS) and to inhibit malic enzyme activity and NADPH supply, resulting possibly in cell proliferation and alteration in the fatty acid composition. In the present study, the effect of sesamol on the growth and accumulation of docosahexaenoic acid (DHA) was investigated in the marine microalga Crypthecodinium cohnii, a prolific producer of DHA. C. cohnii showed a great decrease in the intracellular ROS level with the addition of sesamol. In contrast, the biomass concentration, DHA content (% of total fatty acids), and DHA productivity were significantly increased by 44.20, 11.25, and 20.00%, respectively (P < 0.01). Taken together, this work represents the first report of employing sesamol for enhanced production of DHA by C. cohnii, providing valuable insights into this alga for future biotechnological applications.

  • Mutation Breeding of Extracellular Polysaccharide-Producing Microalga Crypthecodinium cohnii by a Novel Mutagenesis with Atmospheric and Room Temperature Plasma
    International journal of molecular sciences, 2015
    Co-Authors: Bin Liu, Yue Jiang, Zheng Sun, Bo Yang, Dong Wei, Feng Chen
    Abstract:

    Extracellular polysaccharides (EPS) produced by marine microalgae have the potential to be used as antioxidants, antiviral agents, immunomodulators, and anti-inflammatory agents. Although the marine microalga Crypthecodinium cohnii releases EPS during the process of docosahexaenoic acid (DHA) production, the yield of EPS remains relatively low. To improve the EPS production, a novel mutagenesis of C. cohnii was conducted by atmospheric and room temperature plasma (ARTP). Of the 12 mutants obtained, 10 mutants exhibited significantly enhanced EPS yield on biomass as compared with the wild type strain. Among them, mutant M7 was the best as it could produce an EPS volumetric yield of 1.02 g/L, EPS yield on biomass of 0.39 g/g and EPS yield on glucose of 94 mg/g, which were 33.85%, 85.35% and 57.17% higher than that of the wild type strain, respectively. Results of the present study indicated that mutagenesis of the marine microalga C. cohnii by ARTP was highly effective leading to the high-yield production of EPS.

  • Sesamol Enhances Cell Growth and the Biosynthesis and Accumulation of Docosahexaenoic Acid in the Microalga Crypthecodinium cohnii
    2015
    Co-Authors: Bin Liu, Yue Jiang, Jin Liu, Peipei Sun, Feng Chen
    Abstract:

    Sesamol is a strong antioxidant phenolic compound found in sesame seed. It possesses the ability to scavenge intracellular reactive oxygen species (ROS) and to inhibit malic enzyme activity and NADPH supply, resulting possibly in cell proliferation and alteration in the fatty acid composition. In the present study, the effect of sesamol on the growth and accumulation of docosahexaenoic acid (DHA) was investigated in the marine microalga Crypthecodinium cohnii, a prolific producer of DHA. C. cohnii showed a great decrease in the intracellular ROS level with the addition of sesamol. In contrast, the biomass concentration, DHA content (% of total fatty acids), and DHA productivity were significantly increased by 44.20, 11.25, and 20.00%, respectively (P < 0.01). Taken together, this work represents the first report of employing sesamol for enhanced production of DHA by C. cohnii, providing valuable insights into this alga for future biotechnological applications

  • Studies on Docosahexaenoic Acid Production by Suspension Culture of Crypthecodinium cohnii ATCC30556
    Journal of Wuxi University of Light Industry, 2002
    Co-Authors: Jufang Wang, Shizhong Liang, Feng Chen
    Abstract:

    The effects of the culture temperature, initial pH of medium, carbon source and nitrogen source on the production of docosahexaenoic acid by Crypthecodinium cohnii ATCC30556 were studied. Through orthogonal experiments, the optimum culuture medium was obtained (g/L): glucose, 20; glycerol, 20; peptone, 5; KNO_3, 5; NaCl, 6; MgSO_4, 1.6; KH_2PO_4, 1.0; vitamin H, 0.006; vitamin B_(12), 0.001 as well as 1 ml/L olive oil and 6 ml/L pyruvic acid. Optimum culture conditions were followings: 5% inoculum, initial pH 7.0, culture in dark, 50 mL medium in 500 mL flask, after culturing at 30 ℃ for 32 h, then shifting into 20 ℃ until harvesting. Under the optimal conditions, dry biomass and DHA yields were 10.78 g/L and 1.21 g/L respectively after 64 hours^ suspension culture in flask.

Weiwen Zhang - One of the best experts on this subject based on the ideXlab platform.

  • Rewiring metabolic network by chemical modulator based laboratory evolution doubles lipid production in Crypthecodinium cohnii.
    Metabolic engineering, 2018
    Co-Authors: Jinjin Diao, Liangsen Liu, Xinyu Song, Jinyu Cui, Mengliang Shi, Fangzhong Wang, Weiwen Zhang
    Abstract:

    Abstract Dietary omega-3 long-chain polyunsaturated fatty acids docosahexaenoic acid (DHA, C22:6) can be synthesized in microalgae Crypthecodinium cohnii; however, its productivity is still low. Here, we established a new protocol termed as “chemical modulator based adaptive laboratory evolution” (CM-ALE) to enhance lipid and DHA productivity in C. cohnii. First, ACCase inhibitor sethoxydim based CM-ALE was applied to redirect carbon equivalents from starch to lipid. Second, CM-ALE using growth modulator sesamol as selection pressure was conducted to relive negative effects of sesamol on lipid biosynthesis in C. cohnii, which allows enhancement of biomass productivity by 30% without decreasing lipid content when sesamol was added. After two-step CM-ALE, the lipid and DHA productivity in C. cohnii was respectively doubled to a level of 0.046 g/L/h and 0.025 g/L/h in culture with addition of 1 mM sesamol, demonstrating that this two-step CM-ALE could be a valuable approach to maximize the properties of microalgae.

  • Nitrogen Feeding Strategies and Metabolomic Analysis To Alleviate High-Nitrogen Inhibition on Docosahexaenoic Acid Production in Crypthecodinium cohnii.
    Journal of agricultural and food chemistry, 2018
    Co-Authors: Liangsen Liu, Lei Chen, Jing Liu, Jinyu Cui, Mengliang Shi, Fangzhong Wang, Ji Yang, Kang Wang, Weiwen Zhang
    Abstract:

    It is well-known that high-nitrogen content inhibits cell growth and docosahexaenoic acid (DHA) biosynthesis in heterotrophic microalgae Crypthecodinium cohnii. In this study, two nitrogen feeding strategies, pulse-feeding and continuous-feeding, were evaluated to alleviate high-nitrogen inhibition effects on C. cohnii. The results showed that continuous-feeding with a medium solution containing 50% ( w/v) yeast extract at 2.1 mL/h during 12-96 h was the optimal nitrogen feeding strategy for the fermentation process, when glucose concentration was maintained at 15-27 g/L during the same period. With the optimized strategy, 71.2 g/L of dry cell weight and DHA productivity of 57.1 mg/L/h were achieved. In addition, metabolomic analysis was applied to determine the metabolic changes during different nitrogen feeding conditions, and the changes in amino acids, polysaccharides, purines, and pentose phosphate pathway were observed, providing valuable metabolite-level information for exploring the mechanism of the high-nitrogen inhibition effect and further improving DHA productivity in C. cohnii.

  • 13C Metabolic Flux Analysis of Enhanced Lipid Accumulation Modulated by Ethanolamine in Crypthecodinium cohnii.
    Frontiers in microbiology, 2018
    Co-Authors: Jinyu Cui, Jinjin Diao, Liangsen Liu, Lei Chen, Mengliang Shi, Fangzhong Wang, Tao Sun, Weiwen Zhang
    Abstract:

    The heterotrophic microalga Crypthecodinium cohnii has attracted considerable attention due to its capability of accumulating lipids with a high fraction of docosahexaenoic acid (DHA). In our previous study, ethanolamine (ETA) was identified as an effective chemical modulator for lipid accumulation in C. cohnii. In this study, to gain a better understanding of the lipid metabolism and mechanism for the positive effects of modulator ETA, metabolic flux analysis was performed using 13C-labeled glucose with and without 1 mM ETA modulator. The analysis of flux distribution showed that with the addition of ETA, flux in glycolysis pathway and citrate pyruvate cycle was strengthened while flux in pentose phosphate pathway was decreased. In addition, flux in TCA cycle was slightly decreased compared with the control without ETA. The enzyme activity of malic enzyme (ME) was significantly increased, suggesting that NADP+-dependent ME might be the major source of NADPH for lipid accumulation. The flux information obtained by this study could be valuable for the further efforts in improving lipid accumulation and DHA production in C. cohnii.

  • Genetic Engineering of Crypthecodinium cohnii to Increase Growth and Lipid Accumulation
    Frontiers in microbiology, 2018
    Co-Authors: Jinjin Diao, Lei Chen, Xinyu Song, Xiaoqing Zhang, Weiwen Zhang
    Abstract:

    In this study, we evaluated suitable selected markers and optimized transformation protocols to develop a new genetic transformation methodology for DHA-producing Crypthecodinium cohnii. Additionally, ribulose 1,5-bisphosphate carboxylase/oxygenase (RuBisCO), potentially involved in CO2 fixation under autotrophic conditions, was selected as the target for construction of a gene knockdown mutant. Our results show that the constructs were successfully inserted into the C. cohnii chromosome by homologous recombination. Comparative analysis showed that deletion of the RuBisCO gene promoted cell growth and increased the lipid content of C. cohnii under heterotrophic conditions compared with those of the wild-type. The liquid chromatography-mass spectrometry (LC-MS) based metabolomic analysis showed that the metabolites involved in energy metabolism were upregulated, suggesting that the deletion of the RuBisCO gene may contribute to the re-direction of more carbon or energy toward growth and lipid accumulation under heterotrophic conditions.

  • Nitrogen Feeding Strategies and Metabolomic Analysis To Alleviate High-Nitrogen Inhibition on Docosahexaenoic Acid Production in Crypthecodinium cohnii
    2018
    Co-Authors: Liangsen Liu, Lei Chen, Jing Liu, Jinyu Cui, Mengliang Shi, Fangzhong Wang, Ji Yang, Kang Wang, Weiwen Zhang
    Abstract:

    It is well-known that high-nitrogen content inhibits cell growth and docosahexaenoic acid (DHA) biosynthesis in heterotrophic microalgae Crypthecodinium cohnii. In this study, two nitrogen feeding strategies, pulse-feeding and continuous-feeding, were evaluated to alleviate high-nitrogen inhibition effects on C. cohnii. The results showed that continuous-feeding with a medium solution containing 50% (w/v) yeast extract at 2.1 mL/h during 12–96 h was the optimal nitrogen feeding strategy for the fermentation process, when glucose concentration was maintained at 15–27 g/L during the same period. With the optimized strategy, 71.2 g/L of dry cell weight and DHA productivity of 57.1 mg/L/h were achieved. In addition, metabolomic analysis was applied to determine the metabolic changes during different nitrogen feeding conditions, and the changes in amino acids, polysaccharides, purines, and pentose phosphate pathway were observed, providing valuable metabolite-level information for exploring the mechanism of the high-nitrogen inhibition effect and further improving DHA productivity in C. cohnii

Yue Jiang - One of the best experts on this subject based on the ideXlab platform.

  • Article Mutation Breeding of Extracellular Polysaccharide-Producing Microalga Crypthecodinium cohnii by a Novel Mutagenesis with Atmospheric and Room Temperature Plasma
    2015
    Co-Authors: Bin Liu, Yue Jiang, Zheng Sun, Bo Yang, Dong Wei, Feng Chen
    Abstract:

    Abstract: Extracellular polysaccharides (EPS) produced by marine microalgae have the potential to be used as antioxidants, antiviral agents, immunomodulators, and anti-inflammatory agents. Although the marine microalga Crypthecodinium cohnii releases EPS during the process of docosahexaenoic acid (DHA) production, the yield of EPS remains relatively low. To improve the EPS production, a novel mutagenesis of C. cohnii was conducted by atmospheric and room temperature plasma (ARTP). Of the 12 mutants obtained, 10 mutants exhibited significantly enhanced EPS yield on biomass as compared with the wild type strain. Among them, mutant M7 was the best as it could produce an EPS volumetric yield of 1.02 g/L, EPS yield on biomass of 0.39 g/g and EPS yield on glucose of 94 mg/g, which were 33.85%, 85.35 % and 57.17 % higher than that of the wild typ

  • Sesamol Enhances Cell Growth and the Biosynthesis and Accumulation of Docosahexaenoic Acid in the Microalga Crypthecodinium cohnii
    Journal of agricultural and food chemistry, 2015
    Co-Authors: Bin Liu, Yue Jiang, Jin Liu, Peipei Sun, Feng Chen
    Abstract:

    Sesamol is a strong antioxidant phenolic compound found in sesame seed. It possesses the ability to scavenge intracellular reactive oxygen species (ROS) and to inhibit malic enzyme activity and NADPH supply, resulting possibly in cell proliferation and alteration in the fatty acid composition. In the present study, the effect of sesamol on the growth and accumulation of docosahexaenoic acid (DHA) was investigated in the marine microalga Crypthecodinium cohnii, a prolific producer of DHA. C. cohnii showed a great decrease in the intracellular ROS level with the addition of sesamol. In contrast, the biomass concentration, DHA content (% of total fatty acids), and DHA productivity were significantly increased by 44.20, 11.25, and 20.00%, respectively (P < 0.01). Taken together, this work represents the first report of employing sesamol for enhanced production of DHA by C. cohnii, providing valuable insights into this alga for future biotechnological applications.

  • Mutation Breeding of Extracellular Polysaccharide-Producing Microalga Crypthecodinium cohnii by a Novel Mutagenesis with Atmospheric and Room Temperature Plasma
    International journal of molecular sciences, 2015
    Co-Authors: Bin Liu, Yue Jiang, Zheng Sun, Bo Yang, Dong Wei, Feng Chen
    Abstract:

    Extracellular polysaccharides (EPS) produced by marine microalgae have the potential to be used as antioxidants, antiviral agents, immunomodulators, and anti-inflammatory agents. Although the marine microalga Crypthecodinium cohnii releases EPS during the process of docosahexaenoic acid (DHA) production, the yield of EPS remains relatively low. To improve the EPS production, a novel mutagenesis of C. cohnii was conducted by atmospheric and room temperature plasma (ARTP). Of the 12 mutants obtained, 10 mutants exhibited significantly enhanced EPS yield on biomass as compared with the wild type strain. Among them, mutant M7 was the best as it could produce an EPS volumetric yield of 1.02 g/L, EPS yield on biomass of 0.39 g/g and EPS yield on glucose of 94 mg/g, which were 33.85%, 85.35% and 57.17% higher than that of the wild type strain, respectively. Results of the present study indicated that mutagenesis of the marine microalga C. cohnii by ARTP was highly effective leading to the high-yield production of EPS.

  • Sesamol Enhances Cell Growth and the Biosynthesis and Accumulation of Docosahexaenoic Acid in the Microalga Crypthecodinium cohnii
    2015
    Co-Authors: Bin Liu, Yue Jiang, Jin Liu, Peipei Sun, Feng Chen
    Abstract:

    Sesamol is a strong antioxidant phenolic compound found in sesame seed. It possesses the ability to scavenge intracellular reactive oxygen species (ROS) and to inhibit malic enzyme activity and NADPH supply, resulting possibly in cell proliferation and alteration in the fatty acid composition. In the present study, the effect of sesamol on the growth and accumulation of docosahexaenoic acid (DHA) was investigated in the marine microalga Crypthecodinium cohnii, a prolific producer of DHA. C. cohnii showed a great decrease in the intracellular ROS level with the addition of sesamol. In contrast, the biomass concentration, DHA content (% of total fatty acids), and DHA productivity were significantly increased by 44.20, 11.25, and 20.00%, respectively (P < 0.01). Taken together, this work represents the first report of employing sesamol for enhanced production of DHA by C. cohnii, providing valuable insights into this alga for future biotechnological applications

  • Effects of Nitrogen Source and Vitamin B12 on Docosahexaenoic Acid Production by Crypthecodinium cohnii
    Algae and their Biotechnological Potential, 2001
    Co-Authors: Yue Jiang, F. Chen
    Abstract:

    The effects of nitrogen sources and vitamin B12 on cell growth and docosahexaenoic acid (DHA, C22:6 ω-3) content of Crypthecodinium cohnii ATCC 30556 were investigated. Among the three nitrogen sources (tryptone, yeast extract and corn steep liquor) used, tryptone was the best nitrogen source for C. cohnii. The highest specific growth rate (0.087 h-1) and DHA content (64.34% of total fatty acids) were achieved at a tryptone concentration of 1 g/l. Vitamin B12 was not an essential nutrient for the growth of C. cohnii. However, an addition of vitamin B12 to the medium exhibited stimulating effect on the growth of the alga as reflected by a higher specific growth rate and a higher biomass concentration. The highest biomass concentration (2.48 g/l) was obtained at a vitamin B12 concentration of 0.75 µg/l. The results suggest that nitrogen source should be properly selected and vitamin B12 should be added in the defined artificial medium for the optimal production of DHA by C. cohnii.

Chen Feng - One of the best experts on this subject based on the ideXlab platform.

  • Mutation Breeding of Extracellular Polysaccharide-Producing Microalga Crypthecodinium cohnii by a Novel Mutagenesis with Atmospheric and Room Temperature Plasma
    international journal of molecular sciences, 2015
    Co-Authors: Liu Bin, Ma Xiaonian, Jiang Yue, Sun Zheng, Wei Dong, Chen Feng
    Abstract:

    Extracellular polysaccharides (EPS) produced by marine microalgae have the potential to be used as antioxidants, antiviral agents, immunomodulators, and anti-inflammatory agents. Although the marine microalga Crypthecodinium cohnii releases EPS during the process of docosahexaenoic acid (DHA) production, the yield of EPS remains relatively low. To improve the EPS production, a novel mutagenesis of C. cohnii was conducted by atmospheric and room temperature plasma (ARTP). Of the 12 mutants obtained, 10 mutants exhibited significantly enhanced EPS yield on biomass as compared with the wild type strain. Among them, mutant M7 was the best as it could produce an EPS volumetric yield of 1.02 g/L, EPS yield on biomass of 0.39 g/g and EPS yield on glucose of 94 mg/g, which were 33.85%, 85.35% and 57.17% higher than that of the wild type strain, respectively. Results of the present study indicated that mutagenesis of the marine microalga C. cohnii by ARTP was highly effective leading to the high-yield production of EPS.SCI(E)PubMed0ARTICLEcaisanrenju@163.com; zsun@shou.edu.cn; ydchmn@126.com; ly_mikeyang@163.com; jiangyue@tust.edu.cn; fewd304@scut.edu.cn; sfchencoe@pku.edu.cn48201-121

  • Sesamol Enhances Cell Growth and the Biosynthesis and Accumulation of Docosahexaenoic Acid in the Microalga Crypthecodinium cohnii
    JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY, 2015
    Co-Authors: Liu Bin, Liu Jin, Sun Peipei, Ma Xiaonian, Jiang Yue, Chen Feng
    Abstract:

    Sesamol is a strong, antioxidant phenolic compound found sesame seed. It possesses the ability to scavenge intracellular reactive oxygen species (ROS) and to inhibit malic enzyme activity and NADPH supply, resulting possibly in cell proliferation and alteration in the fatty acid composition. In the present study, the effect of sesamol on the growth and accumulation of docosahexaenoic acid (DHA) was investigated in the Marine microalga Crypthecodinium cohnii, a prolific producer of DHA. C. cohnii showed a great decrease in the intracellular ROS level with the addition of sesamol. In contrast, the biomass concentration, DHA content (% of total fatty acids), and DHA productivity were significantly increased by 44.20, 11.25, and 20.00%, respectively (P < 0.01). Taken together, this work represents the first report of employing sesamol for enhanced production of DHA by C. cohnii, providing, valuable insights into this alga for future biotechnological applications.985 Project of Peking University; 863 Plan of Ministry of Science and Technology of China [2012AA023107]; Public Science and Technology Research Funds Projects of Ocean [201505032]; National Natural Science Foundation of China [31471717]SCI(E)EIPubMedARTICLEsfchencoe@pku.edu.cn235640-56456

  • EFFECTS OF ENVIRONMENTAL CONDITIONS ON GROWTH AND DHA YIELD OF Crypthecodinium cohnii
    Marine Sciences, 2002
    Co-Authors: Chen Feng
    Abstract:

    The effect of environmental conditions on growth and DHA yield was determined in Crypthecodinium cohnii ATCC30556. The results showed the optimal conditions were the following: temperature shift was shifting to 20 ℃ after culturing at 30 ℃ for 32 h, pH 7.0, 50 ml/500 ml volume of fermentation medium in flask and 5% inoculum size..

Bin Liu - One of the best experts on this subject based on the ideXlab platform.

  • Article Mutation Breeding of Extracellular Polysaccharide-Producing Microalga Crypthecodinium cohnii by a Novel Mutagenesis with Atmospheric and Room Temperature Plasma
    2015
    Co-Authors: Bin Liu, Yue Jiang, Zheng Sun, Bo Yang, Dong Wei, Feng Chen
    Abstract:

    Abstract: Extracellular polysaccharides (EPS) produced by marine microalgae have the potential to be used as antioxidants, antiviral agents, immunomodulators, and anti-inflammatory agents. Although the marine microalga Crypthecodinium cohnii releases EPS during the process of docosahexaenoic acid (DHA) production, the yield of EPS remains relatively low. To improve the EPS production, a novel mutagenesis of C. cohnii was conducted by atmospheric and room temperature plasma (ARTP). Of the 12 mutants obtained, 10 mutants exhibited significantly enhanced EPS yield on biomass as compared with the wild type strain. Among them, mutant M7 was the best as it could produce an EPS volumetric yield of 1.02 g/L, EPS yield on biomass of 0.39 g/g and EPS yield on glucose of 94 mg/g, which were 33.85%, 85.35 % and 57.17 % higher than that of the wild typ

  • Sesamol Enhances Cell Growth and the Biosynthesis and Accumulation of Docosahexaenoic Acid in the Microalga Crypthecodinium cohnii
    Journal of agricultural and food chemistry, 2015
    Co-Authors: Bin Liu, Yue Jiang, Jin Liu, Peipei Sun, Feng Chen
    Abstract:

    Sesamol is a strong antioxidant phenolic compound found in sesame seed. It possesses the ability to scavenge intracellular reactive oxygen species (ROS) and to inhibit malic enzyme activity and NADPH supply, resulting possibly in cell proliferation and alteration in the fatty acid composition. In the present study, the effect of sesamol on the growth and accumulation of docosahexaenoic acid (DHA) was investigated in the marine microalga Crypthecodinium cohnii, a prolific producer of DHA. C. cohnii showed a great decrease in the intracellular ROS level with the addition of sesamol. In contrast, the biomass concentration, DHA content (% of total fatty acids), and DHA productivity were significantly increased by 44.20, 11.25, and 20.00%, respectively (P < 0.01). Taken together, this work represents the first report of employing sesamol for enhanced production of DHA by C. cohnii, providing valuable insights into this alga for future biotechnological applications.

  • Mutation Breeding of Extracellular Polysaccharide-Producing Microalga Crypthecodinium cohnii by a Novel Mutagenesis with Atmospheric and Room Temperature Plasma
    International journal of molecular sciences, 2015
    Co-Authors: Bin Liu, Yue Jiang, Zheng Sun, Bo Yang, Dong Wei, Feng Chen
    Abstract:

    Extracellular polysaccharides (EPS) produced by marine microalgae have the potential to be used as antioxidants, antiviral agents, immunomodulators, and anti-inflammatory agents. Although the marine microalga Crypthecodinium cohnii releases EPS during the process of docosahexaenoic acid (DHA) production, the yield of EPS remains relatively low. To improve the EPS production, a novel mutagenesis of C. cohnii was conducted by atmospheric and room temperature plasma (ARTP). Of the 12 mutants obtained, 10 mutants exhibited significantly enhanced EPS yield on biomass as compared with the wild type strain. Among them, mutant M7 was the best as it could produce an EPS volumetric yield of 1.02 g/L, EPS yield on biomass of 0.39 g/g and EPS yield on glucose of 94 mg/g, which were 33.85%, 85.35% and 57.17% higher than that of the wild type strain, respectively. Results of the present study indicated that mutagenesis of the marine microalga C. cohnii by ARTP was highly effective leading to the high-yield production of EPS.

  • Sesamol Enhances Cell Growth and the Biosynthesis and Accumulation of Docosahexaenoic Acid in the Microalga Crypthecodinium cohnii
    2015
    Co-Authors: Bin Liu, Yue Jiang, Jin Liu, Peipei Sun, Feng Chen
    Abstract:

    Sesamol is a strong antioxidant phenolic compound found in sesame seed. It possesses the ability to scavenge intracellular reactive oxygen species (ROS) and to inhibit malic enzyme activity and NADPH supply, resulting possibly in cell proliferation and alteration in the fatty acid composition. In the present study, the effect of sesamol on the growth and accumulation of docosahexaenoic acid (DHA) was investigated in the marine microalga Crypthecodinium cohnii, a prolific producer of DHA. C. cohnii showed a great decrease in the intracellular ROS level with the addition of sesamol. In contrast, the biomass concentration, DHA content (% of total fatty acids), and DHA productivity were significantly increased by 44.20, 11.25, and 20.00%, respectively (P < 0.01). Taken together, this work represents the first report of employing sesamol for enhanced production of DHA by C. cohnii, providing valuable insights into this alga for future biotechnological applications