The Experts below are selected from a list of 492 Experts worldwide ranked by ideXlab platform
Tianzhong Liu - One of the best experts on this subject based on the ideXlab platform.
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Studies on the Attached Cultivation of Filamentous Oleaginous Microalga Tribonema minus
Journal of Ocean University of China, 2020Co-Authors: Yan Zhang, Wenjun Zhou, Hui Wang, Junfeng Wang, Tianzhong LiuAbstract:Attached cultivation is a promising method for microalgal biomass production. Filamentous oleaginous microalga Tribonema minus (hereafter T. minus) has shown a remarkable potential for biofuel production in terms of its high lipid content. However, the strain has only been cultivated in suspended cultivation systems including open pond and closed photobioreactors. Here, we attempted to study the attached cultivation of T. minus, which might be helpful for its scale-up cultivation and industrial applications. As the results, the optimal conditions for T. minus growth in the attached biofilm are 200 μmol photons m−2 s−1 of light intensity and 5% of CO2, and the maximum biomass density of 223 g m−2 has been achieved under the light intensity. The non-woven fabric as substratum was found as the best substratum in thin layer attached bioreactor, on which the average biomass productivity of T. minus is about (9.73 ± 2.19) g m−2 d−1. Furthermore, two attached bioreactor systems, rotary drum and rotation disc, were designed following the light dilution strategy and introduced into T. minus cultivation. The highest footprint areal biomass productivity of these two systems is 33 and 47.1 g m−2 d−1, respectively, much higher than that in suspended cultivation system. The results shows that T. minus can be cultured with attached cultivation method to improve its biomass productivity.
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Genetic Transformation of Tribonema minus, a Eukaryotic Filamentous Oleaginous Yellow-Green Alga
International journal of molecular sciences, 2020Co-Authors: Yan Zhang, Hui Wang, Ruigang Yang, Lihao Wang, Guanpin Yang, Tianzhong LiuAbstract:Eukaryotic filamentous yellow-green algae from the Tribonema genus are considered to be excellent candidates for biofuels and value-added products, owing to their ability to grow under autotrophic, mixotrophic, and heterotrophic conditions and synthesize large amounts of fatty acids, especially unsaturated fatty acids. To elucidate the molecular mechanism of fatty acids and/or establish the organism as a model strain, the development of genetic methods is important. Towards this goal, here, we constructed a genetic transformation method to introduce exogenous genes for the first time into the eukaryotic filamentous alga Tribonema minus via particle bombardment. In this study, we constructed pSimple-tub-eGFP and pEASY-tub-nptⅡ plasmids in which the green fluorescence protein (eGFP) gene and the neomycin phosphotransferase Ⅱ-encoding G418-resistant gene (nptⅡ) were flanked by the T. minus-derived tubulin gene (tub) promoter and terminator, respectively. The two plasmids were introduced into T. minus cells through particle-gun bombardment under various test conditions. By combining agar and liquid selecting methods to exclude the pseudotransformants under long-term antibiotic treatment, plasmids pSimple-tub-eGFP and pEASY-tub- nptⅡ were successfully transformed into the genome of T. minus, which was verified using green fluorescence detection and the polymerase chain reaction, respectively. These results suggest new possibilities for efficient genetic engineering of T. minus for future genetic improvement.
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Partial Characterization, the Immune Modulation and Anticancer Activities of Sulfated Polysaccharides from Filamentous Microalgae Tribonema sp.
Molecules (Basel Switzerland), 2019Co-Authors: Xiaolin Chen, Hui Wang, Tianzhong Liu, Lin Song, Song Liu, Wang Xueqin, Li PengchengAbstract:Recently, Tribonema sp., a kind of filamentous microalgae, has been studied for biofuel production due to its accumulation of triacylglycerols. However, the polysaccharides of Tribonema sp. and their biological activities have rarely been reported. In this paper, we extracted sulfated polysaccharides from Tribonema sp. (TSP), characterized their chemical composition and structure, and determined their immunostimulation and anticancer activities on RAW264.7 macrophage cells and HepG2 cells. The results showed that TSP is a sulfated polysaccharide with a Mw of 197 kDa. TSP is a heteropolysaccharide that is composed mainly of galactose. It showed significant immune-modulatory activity by stimulating macrophage cells, such as upregulating interleukin 6 (IL-6), interleukin 10 (IL-10), and tumor necrosis factor α (TNF-α). In addition, TSP also showed significant dose-dependent anticancer activity (with an inhibition rate of up to 66.8% at 250 µg/mL) on HepG2 cells as determined by the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The cycle analysis indicated that the anticancer activity of TSP is mainly the result of induced cell apoptosis rather than affecting the cell cycle and mitosis of HepG2 cells. These findings suggest that TSP might have potential as an anticancer resource, but further research is needed, especially in vivo experiments, to explore the anticancer mechanism of TSP.
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An oleaginous filamentous microalgae Tribonema minus exhibits high removing potential of industrial phenol contaminants.
Bioresource technology, 2017Co-Authors: Cheng Tianyou, Hui Wang, Wei Zhang, Wenlei Zhang, Guanhua Yuan, Tianzhong LiuAbstract:Abstract Discharge of industrial phenol contaminants could cause great harm on natural environment. Through oleaginous microalgae cultivation in phenolic wastewater, pollutants can be phototrophically biofixed into biomass as feedstock for bioenergy production. It was firstly reported in this study that, an oleaginous filamentous microalgae Tribonema minus exhibited strong environmental phenol removal ability. T. minus filaments showed 449.46 mg g −1 of phenol-uptake capacity, obviously higher than those strains with low phenol absorption such as Scenedesmus dimorphus . And phenols could be removed efficiently at the initial phenol concentration up to 700 mg L −1 . Simultaneously, through T. minus growth, phenol concentration could be decreased from 100 mg L −1 to the range of 0.1–0.5 mg L −1 , which meet industrial discharge need of phenol contaminants in most countries. So Tribonema minus is a potential algal specie to help the construction of integrated process for both oleaginous biomass production and bioremediation of phenol contaminants.
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A comparative analysis of biomass and lipid content in five Tribonema sp strains at autotrophic, heterotrophic and mixotrophic cultivation
Algal Research, 2017Co-Authors: Hui Wang, Huimin Shao, Wenjun Zhou, Tianzhong LiuAbstract:Microalgae Tribonema sp. is the first reported filamentous strain which has capability to accumulate large amounts of lipid, especially triacylglycerols (TAGs), useful for biodiesel production. In this study, five filamentous strains identified as Tribonema sp. were cultured with different carbon source and nitrogen source in batch cultures, and their biomass and total lipid contents were determined. In terms of high biomass and lipid contents, strains EA903 and EA904 were further cultivated in scale up cultures at photoautotrophic (CO2 as the carbon source), heterotrophic (glucose as the carbon source, NaNO3 and peptone as the nitrogen source, respectively) and mixotrophic (heterotrophic + light) conditions. Results suggested that autotrophic and glucose-treated cultures of Tribonema sp. strains (both EA903 and EA904) showed an evident difference on the biomass concentrations. Moreover, in spite of being characterized by higher biomass concentrations, strains EA903 and EA904 grown in heterotrophic cultivation with addition of peptone yielded lower lipid contents than those in autotrophic and heterotrophic cultivation with addition of NaNO3. The highest lipid productivity was achieved at the mixotrophic cultivation with NaNO3 addition.
Hui Wang - One of the best experts on this subject based on the ideXlab platform.
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Studies on the Attached Cultivation of Filamentous Oleaginous Microalga Tribonema minus
Journal of Ocean University of China, 2020Co-Authors: Yan Zhang, Wenjun Zhou, Hui Wang, Junfeng Wang, Tianzhong LiuAbstract:Attached cultivation is a promising method for microalgal biomass production. Filamentous oleaginous microalga Tribonema minus (hereafter T. minus) has shown a remarkable potential for biofuel production in terms of its high lipid content. However, the strain has only been cultivated in suspended cultivation systems including open pond and closed photobioreactors. Here, we attempted to study the attached cultivation of T. minus, which might be helpful for its scale-up cultivation and industrial applications. As the results, the optimal conditions for T. minus growth in the attached biofilm are 200 μmol photons m−2 s−1 of light intensity and 5% of CO2, and the maximum biomass density of 223 g m−2 has been achieved under the light intensity. The non-woven fabric as substratum was found as the best substratum in thin layer attached bioreactor, on which the average biomass productivity of T. minus is about (9.73 ± 2.19) g m−2 d−1. Furthermore, two attached bioreactor systems, rotary drum and rotation disc, were designed following the light dilution strategy and introduced into T. minus cultivation. The highest footprint areal biomass productivity of these two systems is 33 and 47.1 g m−2 d−1, respectively, much higher than that in suspended cultivation system. The results shows that T. minus can be cultured with attached cultivation method to improve its biomass productivity.
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Genetic Transformation of Tribonema minus, a Eukaryotic Filamentous Oleaginous Yellow-Green Alga
International journal of molecular sciences, 2020Co-Authors: Yan Zhang, Hui Wang, Ruigang Yang, Lihao Wang, Guanpin Yang, Tianzhong LiuAbstract:Eukaryotic filamentous yellow-green algae from the Tribonema genus are considered to be excellent candidates for biofuels and value-added products, owing to their ability to grow under autotrophic, mixotrophic, and heterotrophic conditions and synthesize large amounts of fatty acids, especially unsaturated fatty acids. To elucidate the molecular mechanism of fatty acids and/or establish the organism as a model strain, the development of genetic methods is important. Towards this goal, here, we constructed a genetic transformation method to introduce exogenous genes for the first time into the eukaryotic filamentous alga Tribonema minus via particle bombardment. In this study, we constructed pSimple-tub-eGFP and pEASY-tub-nptⅡ plasmids in which the green fluorescence protein (eGFP) gene and the neomycin phosphotransferase Ⅱ-encoding G418-resistant gene (nptⅡ) were flanked by the T. minus-derived tubulin gene (tub) promoter and terminator, respectively. The two plasmids were introduced into T. minus cells through particle-gun bombardment under various test conditions. By combining agar and liquid selecting methods to exclude the pseudotransformants under long-term antibiotic treatment, plasmids pSimple-tub-eGFP and pEASY-tub- nptⅡ were successfully transformed into the genome of T. minus, which was verified using green fluorescence detection and the polymerase chain reaction, respectively. These results suggest new possibilities for efficient genetic engineering of T. minus for future genetic improvement.
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comparison of lipid and palmitoleic acid induction of Tribonema minus under heterotrophic and phototrophic regimes by using high density fermented seeds
International Journal of Molecular Sciences, 2019Co-Authors: Wenjun Zhou, Li Zheng, Hui Wang, Wentao ChengAbstract:Palmitoleic acid, one scarce omega-7 monounsaturated fatty acid, has important applications in the fields of medicine and health products. Tribonema has been considered as a promising candidate for the production of palmitoleic acid due to its high lipid and palmitoleic acid content and remarkable heterotrophic ability. The high-density heterotrophic cultivation of Tribonema minus was conducted in this work, and the highest biomass of 42.9 g L−1 and a relatively low lipid content of 28.7% were observed. To further enhance the lipid and palmitoleic acid accumulation, induction strategies under two regimes of phototrophy and heterotrophy with different conditions were investigated and compared. Results demonstrated encouraging promotions both by heterotrophic and phototrophic ways, and the final lipid contents reached 41.9% and 49.0%, respectively. In consideration of the time cost, however, the induction under heterotrophic conditions was much more advantageous, by which the highest lipid and palmitoleic acid productivities of 1.77 g L−1 d−1 and 924 mg L−1 d−1 were obtained respectively, with the lipid yield on glucose of 0.26 g g−1.
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Partial Characterization, the Immune Modulation and Anticancer Activities of Sulfated Polysaccharides from Filamentous Microalgae Tribonema sp.
Molecules (Basel Switzerland), 2019Co-Authors: Xiaolin Chen, Hui Wang, Tianzhong Liu, Lin Song, Song Liu, Wang Xueqin, Li PengchengAbstract:Recently, Tribonema sp., a kind of filamentous microalgae, has been studied for biofuel production due to its accumulation of triacylglycerols. However, the polysaccharides of Tribonema sp. and their biological activities have rarely been reported. In this paper, we extracted sulfated polysaccharides from Tribonema sp. (TSP), characterized their chemical composition and structure, and determined their immunostimulation and anticancer activities on RAW264.7 macrophage cells and HepG2 cells. The results showed that TSP is a sulfated polysaccharide with a Mw of 197 kDa. TSP is a heteropolysaccharide that is composed mainly of galactose. It showed significant immune-modulatory activity by stimulating macrophage cells, such as upregulating interleukin 6 (IL-6), interleukin 10 (IL-10), and tumor necrosis factor α (TNF-α). In addition, TSP also showed significant dose-dependent anticancer activity (with an inhibition rate of up to 66.8% at 250 µg/mL) on HepG2 cells as determined by the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The cycle analysis indicated that the anticancer activity of TSP is mainly the result of induced cell apoptosis rather than affecting the cell cycle and mitosis of HepG2 cells. These findings suggest that TSP might have potential as an anticancer resource, but further research is needed, especially in vivo experiments, to explore the anticancer mechanism of TSP.
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heterotrophy of filamentous oleaginous microalgae Tribonema minus for potential production of lipid and palmitoleic acid
Bioresource Technology, 2017Co-Authors: Wenjun Zhou, Hui Wang, Lin Chen, Wentao ChengAbstract:Abstract Heterotrophic fermentation and high valuable co-product producing are thought to be effective ways to improve the economic viability and feasibility of commercial production of microalgae biofuels. This work reported the heterotrophic cultivation of Tribonema minus for lipid and palmitoleic acid (a novel functional fatty acid) production. Firstly, the heterotrophic ability of T. minus was identified for the first time with significant promotion in biomass and lipid productivity, and glucose and urea were then selected as the optimal carbon and nitrogen sources. Moreover, nutrient concentrations and culture conditions were optimized. Highest biomass and lipid productivity of 30.8 g L−1 and 730 mg L−1 d−1 were obtained respectively by adding 80 g L−1 glucose at once. In addition, 2 g L−1 urea, 0.8 g L−1 K2HPO4, 24 mg L−1 ammonium ferric citrate, initial pH of 6, and temperature of 27 °C were determined as the appropriate conditions for heterotrophic growth and lipid production.
Shuhao Huo - One of the best experts on this subject based on the ideXlab platform.
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Post treatment of swine anaerobic effluent by weak electric field following intermittent vacuum assisted adjustment of N:P ratio for oil-rich filamentous microalgae production.
Bioresource technology, 2020Co-Authors: Shuhao Huo, Sajid Basheer, Pengfei Cheng, Feifei Zhu, Dongjie Chen, Junzhi Liu, David Necas, Renchuan Zhang, Krik CobbAbstract:Abstract A weak electric field (EF) was applied to decolorize the swine anaerobic effluent, which was followed by N:P ratio adjustment via intermittent-vacuum stripping (IVS) system for oil-rich filamentous microalgae Tribonema sp. cultivation. A higher electric field strength, higher temperature, and lower pH conditions showed higher efficiency in decolorization and nutrients removal during EF application. In the group of 30:1 (N:P) ratio, Tribonema sp. had the largest biomass accumulation (2.04 g·L−1) after 14 days cultivation. However, the 20:1 group had highest oil accumulation (oil content 55.4 ± 3.4%), while 30:1 (N: P) group was 42.3 ± 1.8%. Under the conditions of sufficient nitrogen (50:1 group), the highest contents of α-linolenic acid (15.5%) and ω-3 fatty acids (21.8%) were reached. The integrated treatment of EF, IVS and microalgae cultivation demonstrated to be effective for nutrients recycling and sustainable biomass production.
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Magnetic field intervention on growth of the filamentous microalgae Tribonema sp. in starch wastewater for algal biomass production and nutrients removal: Influence of ambient temperature and operational strategy
Bioresource technology, 2020Co-Authors: Shuhao Huo, Kirk Cobb, Feifei Zhu, Xiu Chen, Wanqin Zhang, Dongjie Chen, Nana Jin, Yanling Cheng, Lu Wang, Roger RuanAbstract:Abstract This paper investigated the effects of temperature and cultivation methods (batch or semi-continuous culture) on the filamentous microalgae Tribonema sp. biomass production and nutrients removal in starch wastewater under low intensity magnetic field (MF) intervention. The MF significantly promoted algal growth in the late logarithmic-phase of batch cultivation, and the effect was even more obvious at lower temperatures. The MF treated group at 30 °C accumulated the highest biomass of 4.44 g/L of batch culture, an increase of 15.0% compared with the control group. The oil content of Tribonema sp. was enhanced with the MF intervention, especially for the batch culture. In the semi-continuous culture under MF intervention, Tribonema sp. reached the high biomass of 18.45 g/L after 25 days. When gradually reducing hydraulic retention time (HRT) to 1 day, the average removal rates for COD, TN, NH3-N and TP were all more than 90% in the semi-continuous cultivation.
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Bacterial intervention on the growth, nutrient removal and lipid production of filamentous oleaginous microalgae Tribonema sp.
Algal Research, 2020Co-Authors: Shuhao Huo, Sajid Basheer, Fen Liu, Mostafa E. Elshobary, Cunsheng Zhang, Jing-ya Qian, Muhammad Arslan, Fengjie Cui, Zan XinyiAbstract:Abstract The present study explores the effects of three bacteria, namely Rhizobium rosettiformans, Hydrogenophaga intermedia, Sphingopyxis terrae and their mix culture on the growth, pigment content, nutrient removal, lipid content and fatty acid composition of microalgae Tribonema sp. S. terrae and mix culture did not affect the biomass of Tribonema sp. noticeably while H. intermedia and R. rosettiformans significantly reduce the biomass. The removal rate of total phosphorous (TP) and total nitrogen (TN) were boosted to 98.34% and 94.64% by addition of S. terrae and Tribonema sp., respectively compared to control (90.13% and 86.20%, respectively). Moreover, S. terrae improved the chlorophyll b content significantly in Tribonema sp. to 1.17 mg/g by 18% higher than the control group. Addition of S. terrae and R. rosettiformans increased the lipid content of Tribonema sp. by 21% and 13%, respectively compared to the control. Regarding fatty acid (FA) profile and biodiesel properties, co-culture of S. terrae with Tribonema sp. showed high contents of unsaturated fatty acid (USFA) and C16-C18 FA, plus low saturated fatty acid (SFA) and polyunsaturated fatty acid (PUFA) contents that are preferable for excellent biodiesel performance. Hence, the S. terrae intervention has the most significant effect on nutrients removal, pigment content, lipid content and biodiesel quality.
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filamentous microalgae Tribonema sp cultivation in the anaerobic oxic effluents of petrochemical wastewater for evaluating the efficiency of recycling and treatment
Biochemical Engineering Journal, 2019Co-Authors: Shuhao Huo, Sajid Basheer, Fengjie Cui, Feifei Zhu, Bin Zou, Xiu Chen, Jing Chen, Jing-ya QianAbstract:Abstract The filamentous microalgae Tribonema sp. was cultured in the effluents of different stages (the primary clarifier, the anaerobic and the anaerobic/oxic) of the traditional Anaerobic/Oxic (A/O) process for evaluating the recycling and treatment efficiency of the petrochemical wastewater in this paper. It was observed that Tribonema sp. grew in the anaerobic effluent had the ideal growth states and wastewater treatment efficiency. The biomass concentration, the chemical oxygen demand (COD), and total nitrogen (TN) removal rates were 4.4 g/L, 98.4% and 96.8%, respectively, for Tribonema sp. grown in the anaerobic effluent. Moreover, the total phosphorus (TP) and organic contaminants were almost completely removed and the oil content of the microalgae reached the highest (36.1%) in the anaerobic effluent. The filamentous microalgae Tribonema sp. cultivation directly integrated with the treatment of anaerobic effluents is demonstrated as an alternative approach to the traditional oxic stage in the A/O process.
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Filamentous microalgae Tribonema sp. cultivation in the anaerobic/oxic effluents of petrochemical wastewater for evaluating the efficiency of recycling and treatment
Biochemical Engineering Journal, 2019Co-Authors: Shuhao Huo, Sajid Basheer, Fengjie Cui, Chen Jing, Feifei Zhu, Bin Zou, Xiu Chen, Jing-ya QianAbstract:Abstract The filamentous microalgae Tribonema sp. was cultured in the effluents of different stages (the primary clarifier, the anaerobic and the anaerobic/oxic) of the traditional Anaerobic/Oxic (A/O) process for evaluating the recycling and treatment efficiency of the petrochemical wastewater in this paper. It was observed that Tribonema sp. grew in the anaerobic effluent had the ideal growth states and wastewater treatment efficiency. The biomass concentration, the chemical oxygen demand (COD), and total nitrogen (TN) removal rates were 4.4 g/L, 98.4% and 96.8%, respectively, for Tribonema sp. grown in the anaerobic effluent. Moreover, the total phosphorus (TP) and organic contaminants were almost completely removed and the oil content of the microalgae reached the highest (36.1%) in the anaerobic effluent. The filamentous microalgae Tribonema sp. cultivation directly integrated with the treatment of anaerobic effluents is demonstrated as an alternative approach to the traditional oxic stage in the A/O process.
Wenjun Zhou - One of the best experts on this subject based on the ideXlab platform.
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Studies on the Attached Cultivation of Filamentous Oleaginous Microalga Tribonema minus
Journal of Ocean University of China, 2020Co-Authors: Yan Zhang, Wenjun Zhou, Hui Wang, Junfeng Wang, Tianzhong LiuAbstract:Attached cultivation is a promising method for microalgal biomass production. Filamentous oleaginous microalga Tribonema minus (hereafter T. minus) has shown a remarkable potential for biofuel production in terms of its high lipid content. However, the strain has only been cultivated in suspended cultivation systems including open pond and closed photobioreactors. Here, we attempted to study the attached cultivation of T. minus, which might be helpful for its scale-up cultivation and industrial applications. As the results, the optimal conditions for T. minus growth in the attached biofilm are 200 μmol photons m−2 s−1 of light intensity and 5% of CO2, and the maximum biomass density of 223 g m−2 has been achieved under the light intensity. The non-woven fabric as substratum was found as the best substratum in thin layer attached bioreactor, on which the average biomass productivity of T. minus is about (9.73 ± 2.19) g m−2 d−1. Furthermore, two attached bioreactor systems, rotary drum and rotation disc, were designed following the light dilution strategy and introduced into T. minus cultivation. The highest footprint areal biomass productivity of these two systems is 33 and 47.1 g m−2 d−1, respectively, much higher than that in suspended cultivation system. The results shows that T. minus can be cultured with attached cultivation method to improve its biomass productivity.
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comparison of lipid and palmitoleic acid induction of Tribonema minus under heterotrophic and phototrophic regimes by using high density fermented seeds
International Journal of Molecular Sciences, 2019Co-Authors: Wenjun Zhou, Li Zheng, Hui Wang, Wentao ChengAbstract:Palmitoleic acid, one scarce omega-7 monounsaturated fatty acid, has important applications in the fields of medicine and health products. Tribonema has been considered as a promising candidate for the production of palmitoleic acid due to its high lipid and palmitoleic acid content and remarkable heterotrophic ability. The high-density heterotrophic cultivation of Tribonema minus was conducted in this work, and the highest biomass of 42.9 g L−1 and a relatively low lipid content of 28.7% were observed. To further enhance the lipid and palmitoleic acid accumulation, induction strategies under two regimes of phototrophy and heterotrophy with different conditions were investigated and compared. Results demonstrated encouraging promotions both by heterotrophic and phototrophic ways, and the final lipid contents reached 41.9% and 49.0%, respectively. In consideration of the time cost, however, the induction under heterotrophic conditions was much more advantageous, by which the highest lipid and palmitoleic acid productivities of 1.77 g L−1 d−1 and 924 mg L−1 d−1 were obtained respectively, with the lipid yield on glucose of 0.26 g g−1.
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heterotrophy of filamentous oleaginous microalgae Tribonema minus for potential production of lipid and palmitoleic acid
Bioresource Technology, 2017Co-Authors: Wenjun Zhou, Hui Wang, Lin Chen, Wentao ChengAbstract:Abstract Heterotrophic fermentation and high valuable co-product producing are thought to be effective ways to improve the economic viability and feasibility of commercial production of microalgae biofuels. This work reported the heterotrophic cultivation of Tribonema minus for lipid and palmitoleic acid (a novel functional fatty acid) production. Firstly, the heterotrophic ability of T. minus was identified for the first time with significant promotion in biomass and lipid productivity, and glucose and urea were then selected as the optimal carbon and nitrogen sources. Moreover, nutrient concentrations and culture conditions were optimized. Highest biomass and lipid productivity of 30.8 g L−1 and 730 mg L−1 d−1 were obtained respectively by adding 80 g L−1 glucose at once. In addition, 2 g L−1 urea, 0.8 g L−1 K2HPO4, 24 mg L−1 ammonium ferric citrate, initial pH of 6, and temperature of 27 °C were determined as the appropriate conditions for heterotrophic growth and lipid production.
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Lipid accumulation and metabolic analysis based on transcriptome sequencing of filamentous oleaginous microalgae Tribonema minus at different growth phases
Bioprocess and Biosystems Engineering, 2017Co-Authors: Hui Wang, Huimin Shao, Wenjun ZhouAbstract:Filamentous oleaginous microalgae specie Tribonema minus is a promising feedstock for biodiesel production. However, the metabolic mechanism of lipid production in this filamentous microalgal specie remains unclear. Here, we compared the lipid accumulation of T. minus at different growth phases, and described the de novo transcriptome sequencing and assembly and identified important pathways and genes involved in TAG production. Total lipid increased by 2.5-fold and its TAG level in total lipid reached 81.1% at stationary phase. Using the genes involved in the lipid metabolism, the TAG biosynthesis pathways were generated. Moreover, results also demonstrated that, in addition to the observed overexpression of the fatty acid synthesis pathway, TAG production at stationary growth phase was bolstered by repression of the β-oxidation pathway, up-regulation of genes that funnels acetyl-CoA to lipid biosynthesis, especially gene encoding for phospholipid:diacylglycerol acyltransferase (PDAT) which funnels DAG to TAG biosynthesis.
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A comparative analysis of biomass and lipid content in five Tribonema sp strains at autotrophic, heterotrophic and mixotrophic cultivation
Algal Research, 2017Co-Authors: Hui Wang, Huimin Shao, Wenjun Zhou, Tianzhong LiuAbstract:Microalgae Tribonema sp. is the first reported filamentous strain which has capability to accumulate large amounts of lipid, especially triacylglycerols (TAGs), useful for biodiesel production. In this study, five filamentous strains identified as Tribonema sp. were cultured with different carbon source and nitrogen source in batch cultures, and their biomass and total lipid contents were determined. In terms of high biomass and lipid contents, strains EA903 and EA904 were further cultivated in scale up cultures at photoautotrophic (CO2 as the carbon source), heterotrophic (glucose as the carbon source, NaNO3 and peptone as the nitrogen source, respectively) and mixotrophic (heterotrophic + light) conditions. Results suggested that autotrophic and glucose-treated cultures of Tribonema sp. strains (both EA903 and EA904) showed an evident difference on the biomass concentrations. Moreover, in spite of being characterized by higher biomass concentrations, strains EA903 and EA904 grown in heterotrophic cultivation with addition of peptone yielded lower lipid contents than those in autotrophic and heterotrophic cultivation with addition of NaNO3. The highest lipid productivity was achieved at the mixotrophic cultivation with NaNO3 addition.
Feifei Zhu - One of the best experts on this subject based on the ideXlab platform.
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Post treatment of swine anaerobic effluent by weak electric field following intermittent vacuum assisted adjustment of N:P ratio for oil-rich filamentous microalgae production.
Bioresource technology, 2020Co-Authors: Shuhao Huo, Sajid Basheer, Pengfei Cheng, Feifei Zhu, Dongjie Chen, Junzhi Liu, David Necas, Renchuan Zhang, Krik CobbAbstract:Abstract A weak electric field (EF) was applied to decolorize the swine anaerobic effluent, which was followed by N:P ratio adjustment via intermittent-vacuum stripping (IVS) system for oil-rich filamentous microalgae Tribonema sp. cultivation. A higher electric field strength, higher temperature, and lower pH conditions showed higher efficiency in decolorization and nutrients removal during EF application. In the group of 30:1 (N:P) ratio, Tribonema sp. had the largest biomass accumulation (2.04 g·L−1) after 14 days cultivation. However, the 20:1 group had highest oil accumulation (oil content 55.4 ± 3.4%), while 30:1 (N: P) group was 42.3 ± 1.8%. Under the conditions of sufficient nitrogen (50:1 group), the highest contents of α-linolenic acid (15.5%) and ω-3 fatty acids (21.8%) were reached. The integrated treatment of EF, IVS and microalgae cultivation demonstrated to be effective for nutrients recycling and sustainable biomass production.
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Magnetic field intervention on growth of the filamentous microalgae Tribonema sp. in starch wastewater for algal biomass production and nutrients removal: Influence of ambient temperature and operational strategy
Bioresource technology, 2020Co-Authors: Shuhao Huo, Kirk Cobb, Feifei Zhu, Xiu Chen, Wanqin Zhang, Dongjie Chen, Nana Jin, Yanling Cheng, Lu Wang, Roger RuanAbstract:Abstract This paper investigated the effects of temperature and cultivation methods (batch or semi-continuous culture) on the filamentous microalgae Tribonema sp. biomass production and nutrients removal in starch wastewater under low intensity magnetic field (MF) intervention. The MF significantly promoted algal growth in the late logarithmic-phase of batch cultivation, and the effect was even more obvious at lower temperatures. The MF treated group at 30 °C accumulated the highest biomass of 4.44 g/L of batch culture, an increase of 15.0% compared with the control group. The oil content of Tribonema sp. was enhanced with the MF intervention, especially for the batch culture. In the semi-continuous culture under MF intervention, Tribonema sp. reached the high biomass of 18.45 g/L after 25 days. When gradually reducing hydraulic retention time (HRT) to 1 day, the average removal rates for COD, TN, NH3-N and TP were all more than 90% in the semi-continuous cultivation.
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filamentous microalgae Tribonema sp cultivation in the anaerobic oxic effluents of petrochemical wastewater for evaluating the efficiency of recycling and treatment
Biochemical Engineering Journal, 2019Co-Authors: Shuhao Huo, Sajid Basheer, Fengjie Cui, Feifei Zhu, Bin Zou, Xiu Chen, Jing Chen, Jing-ya QianAbstract:Abstract The filamentous microalgae Tribonema sp. was cultured in the effluents of different stages (the primary clarifier, the anaerobic and the anaerobic/oxic) of the traditional Anaerobic/Oxic (A/O) process for evaluating the recycling and treatment efficiency of the petrochemical wastewater in this paper. It was observed that Tribonema sp. grew in the anaerobic effluent had the ideal growth states and wastewater treatment efficiency. The biomass concentration, the chemical oxygen demand (COD), and total nitrogen (TN) removal rates were 4.4 g/L, 98.4% and 96.8%, respectively, for Tribonema sp. grown in the anaerobic effluent. Moreover, the total phosphorus (TP) and organic contaminants were almost completely removed and the oil content of the microalgae reached the highest (36.1%) in the anaerobic effluent. The filamentous microalgae Tribonema sp. cultivation directly integrated with the treatment of anaerobic effluents is demonstrated as an alternative approach to the traditional oxic stage in the A/O process.
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Filamentous microalgae Tribonema sp. cultivation in the anaerobic/oxic effluents of petrochemical wastewater for evaluating the efficiency of recycling and treatment
Biochemical Engineering Journal, 2019Co-Authors: Shuhao Huo, Sajid Basheer, Fengjie Cui, Chen Jing, Feifei Zhu, Bin Zou, Xiu Chen, Jing-ya QianAbstract:Abstract The filamentous microalgae Tribonema sp. was cultured in the effluents of different stages (the primary clarifier, the anaerobic and the anaerobic/oxic) of the traditional Anaerobic/Oxic (A/O) process for evaluating the recycling and treatment efficiency of the petrochemical wastewater in this paper. It was observed that Tribonema sp. grew in the anaerobic effluent had the ideal growth states and wastewater treatment efficiency. The biomass concentration, the chemical oxygen demand (COD), and total nitrogen (TN) removal rates were 4.4 g/L, 98.4% and 96.8%, respectively, for Tribonema sp. grown in the anaerobic effluent. Moreover, the total phosphorus (TP) and organic contaminants were almost completely removed and the oil content of the microalgae reached the highest (36.1%) in the anaerobic effluent. The filamentous microalgae Tribonema sp. cultivation directly integrated with the treatment of anaerobic effluents is demonstrated as an alternative approach to the traditional oxic stage in the A/O process.
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advanced treatment of the low concentration petrochemical wastewater by Tribonema sp microalgae grown in the open photobioreactors coupled with the traditional anaerobic oxic process
Bioresource Technology, 2018Co-Authors: Shuhao Huo, Feifei Zhu, Xiu Chen, Jing Chen, Feng Wang, Danzhao GuoAbstract:Abstract In this paper, the filamentous microalgae Tribonema sp. grown in the open photobioreactors (PBRs) was directly integrated with the traditional Anaerobic/Oxic (A/O) process for the advanced treatment of low concentration petrochemical wastewater. The COD removal rate was only 71.7% after direct treatment of wastewater effluent from the primary clarifier in the open PBRs, while in-depth purification could be achieved in the secondary clarifier with COD removal rates reached to 97.8% in the open PBRs. The NH3-N and P of the two effluents were almost completely removed after 5–7 days in the open PBRs. The biomass concentration, productivity and the oil content in the open PBRs with the secondary clarifier effluent were all higher than those in the primary clarifier group. The filamentous microalgae Tribonema sp. as a post-treatment step for the A/O process can achieve deep removal of the pollutants and accumulate higher biomass concentration and oil content.
