The function of exogenous alanine(Ala)in regulating biomass accumulation,lipid production,photosynthesis,and respiration in Chlorella pyrenoidosa was studied.Result shows that the supplementation of Ala increased C.py...The function of exogenous alanine(Ala)in regulating biomass accumulation,lipid production,photosynthesis,and respiration in Chlorella pyrenoidosa was studied.Result shows that the supplementation of Ala increased C.pyrenoidosa biomass and lipid production in an 8-d batch culture.The concentration of 10 mmol/L of Ala was optimum and increased the microalgal cell biomass and lipid content by 39.3%and 21.4%,respectively,compared with that in the control(0-mmol/L Ala).Ala supplementation reduced photosynthetic activity while boosting respiratory activity and pyruvate levels,indicating that C.pyrenoidosa used exogenous Ala for biomass accumulation through the respiratory metabolic process.The accelerated respiratory metabolism due to Ala supplementation elevated the substrate pool and improved the lipogenic gene expression,promoting lipid production at last.This study provided a novel method for increasing biomass accumulation and lipid production and elucidated the role of Ala in regulating lipid production.展开更多
Chlorella residues are currently underutilized. Therefore, in this study, we analyzed the nutritional components of Chlorella residue, and investigated its potential use as an organic fertilizer/bio-stimulant. Composi...Chlorella residues are currently underutilized. Therefore, in this study, we analyzed the nutritional components of Chlorella residue, and investigated its potential use as an organic fertilizer/bio-stimulant. Composition analyses revealed that the Chlorella residue contained a substantial amount of nitrogen (97,910 mg/kg), and significant quantities of secondary macronutrients, such as calcium (4300 mg/kg) and magnesium (9700 mg/kg), and micronutrients, such as iron (1850 mg/L) and manganese (359 mg/kg). The application of Chlorella residue to soil resulted in increased soil bacterial biomass. When Chlorella residue was added to the soil at a rate of 0.5% or 1.0% (w/w), the fresh weights of Brassica rapa and Spinacia oleracea were significantly increased. Furthermore, the application of Chlorella residue to the soil of B. rapa suppressed the reduction of the microbiome caused by clubroot disease and decreased the clubroot disease index. Therefore, Chlorella residue can be included in organic fertilizers that effectively improve soil nutrient contents, promote plant growth, and reduce the incidence of disease.展开更多
[Objective] The aim of this study is to isolate Chlorella vulgaris(chlorella)and extract its genomic DNA.[Method] Both the dilution method and drip method were employed to isolate chlorella from lake water samples;the...[Objective] The aim of this study is to isolate Chlorella vulgaris(chlorella)and extract its genomic DNA.[Method] Both the dilution method and drip method were employed to isolate chlorella from lake water samples;the conditions for culturing chlorella were optimized and its genomic DNA was extracted by improved CTAB method and SDS method.[Result] The proper conditions for chlorella culture were as following:temperature 20-25 ℃,illumination 4.39-5.86 W/m2 and rotational speed 100-150r/min;improved CTAB method was suitable for extracting genomic DNA from chlorella.[Conclusion] The study is helpful to study the chlorella at molecular level and promote the exploitation and utilization of chlorella resources.展开更多
[Objective] The aim was to investigate the effects of sound wave on propagation of Chlorella pyrenoidosa to explore the optimal frequency for Chlorella pyrenoidosa.[Method] In the research,Chlorella pyrenoidosa was cu...[Objective] The aim was to investigate the effects of sound wave on propagation of Chlorella pyrenoidosa to explore the optimal frequency for Chlorella pyrenoidosa.[Method] In the research,Chlorella pyrenoidosa was cultured for 7 d with sound waves at different frequencies and a control group was set to study effects of sound wave at different frequencies on growth of Chlorella pyrenoidosa.[Result] Growth of Chlorella pyrenoidosa was significantly improved by sound wave,especially for wave at 400 Hz.[Conclusion] Chlorella pyrenoidosa propagation would be promoted by sound wave at certain frequencies.展开更多
[Objective] The aim was to research Chlorella properties in removing ni- trogen and phosphorus from wastewater. [Method] The effects of initial NH4＋-N and total P concentrations, N-to-P ratios, lightJdarkness ratios ...[Objective] The aim was to research Chlorella properties in removing ni- trogen and phosphorus from wastewater. [Method] The effects of initial NH4＋-N and total P concentrations, N-to-P ratios, lightJdarkness ratios and pH on the removal of NH4＋-N and total P were evaluated. [Result] The results showed that Chlorella al- most removed NH4＋-N and total P at 100% as initial concentrations of NH4＋-N and total P were no more than 55 and 7 mg/L, respectively, whereas the removal ratio of NH4＋-N decreased to 90% with initial NH4＋-N concentration coming up to 75 mg/L. With N-to-P ratios of 5：1, 10：1 and 25：1, Chlorella completely removed NH4＋-N within 4 d, while the removal ratio of total P reached almost 100% within 7 d, with different N-to-P ratios. With L./D ratios of 24 h： 0 h and 12 h： 12 h as well as the initial concentrations of NH4＋-N at 30 mg/L and total P at 7 mg/L, the removing ra- tio of NH4＋-N and total P almost achieved 100% by Chlorella, and the removing ra- tio under L/D ratio of 24 h：0 h proved much faster. The optimal pH range for Chlorella to remove NH4＋-N and total P was 7-8. [Conclusion] The research pro- vides references for wastewater treatment in biological way and highly-efficient and environment-friendly treatment in future.展开更多
[Objective] The aim was to study on the chlorella resistance to dehydration conditions and effect of different cryoprotecants on drying of chlorella cells.[Method]The protection effect of seven kinds of cryoprotecants...[Objective] The aim was to study on the chlorella resistance to dehydration conditions and effect of different cryoprotecants on drying of chlorella cells.[Method]The protection effect of seven kinds of cryoprotecants on chlorella cells was analyzed.[Result]The protection effect of trehalose on chlorella cells was the best,and the survival rate of chlorella cells had improved by 50% with the applied trehalose concentration of 5%.[Conclusion]The result in this study had important guidance effect on the mutation breeding of chlorella.展开更多
The contamination reasons were analyzed form the viewpoints of strain preparation, air system, medium and equipment sterilization and pipeline configura- tion. Moreover, the contamination-preventing measures were defi...The contamination reasons were analyzed form the viewpoints of strain preparation, air system, medium and equipment sterilization and pipeline configura- tion. Moreover, the contamination-preventing measures were defined. We also sum- marized the characteristics of bacteria that contaminated the fermentation, as well as checking methods and remedial measures.展开更多
In the present study, genetic polymorphism and diversity in unicellular clones of Chlorella vulgaris Beijerinck and Chlorella pyrenoidosa Chick were studied with Inter Simple Sequence Repeats PCR （ISSR PCR）. Samples...In the present study, genetic polymorphism and diversity in unicellular clones of Chlorella vulgaris Beijerinck and Chlorella pyrenoidosa Chick were studied with Inter Simple Sequence Repeats PCR （ISSR PCR）. Samples including four clones of C. vulgaris and three clones of C. pyrenoidosa were purified by single-clone-choice method. For four C. vulgaris unicellular clones, the total number of the bands scored for 18 primers was 298; and the number of the polymorphic bands was 118, of which 39.6% were polymorphic. The size of PCR products ranged from 200 to 2 500 bp. The total number of bands scored for 18 primers, the number of polymorphic bands and the percentage of three C. pyrenoidosa unicellular clones was 194.83 and 30.8%, respectively. POPGENE analysis show that the average Nei genetic diversity （h^＊） and Shannon index of diversity （I^＊） in the four C. vulgaris unicellular clones was 0.2181 and 0.3208, respectively, which is slightly higher than those of the three C. pyrenoidosa unicellular clones （0.190 3 and 0.274 8）, which agreed with the percentage of polymorphic bands in the mixed samples of the two species. The results suggest that ISSR is a useful method to Chlorella for intra-species genetic analysis.展开更多
[Objective] This study was to realize high-density culture of Chlorella sp. as well as the culture with high lipid yield. [Method] Through analyzing the growth curve of Chlorella sp. cells, dextrose consumption curve,...[Objective] This study was to realize high-density culture of Chlorella sp. as well as the culture with high lipid yield. [Method] Through analyzing the growth curve of Chlorella sp. cells, dextrose consumption curve, change curves of pH and dissolved oxygen, a fed-batch culture was conducted, followed by a nitrogen-deficient culture aiming at accumulating the lipids in Chlorella sp. cells when a high density of Chlorella sp. cells was obtained. [Result] After four batches of feeding were pro- vided, the biomass of Chlorella sp. reached up to 65.25 g/L, and the lipid content increased from 42.75% to 63.82% in Chlorella sp. cells, with the yield of 43.37 g/L in the following 12 hours of nitrogen-deficient culture. [Conclusion] Reasonable fed- batch can significantly improve the biomass of Chlorella sp., and the nitrogen-defi- cient culture further raises the lipid yield of Chlorella sp.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.32002411,42276189)the Innovation and Entrepreneurship Project for College Students of Hohai University(No.2022102941027)the Jiangsu Innovation Center for Marine Bioresources(No.822153216)。
文摘The function of exogenous alanine(Ala)in regulating biomass accumulation,lipid production,photosynthesis,and respiration in Chlorella pyrenoidosa was studied.Result shows that the supplementation of Ala increased C.pyrenoidosa biomass and lipid production in an 8-d batch culture.The concentration of 10 mmol/L of Ala was optimum and increased the microalgal cell biomass and lipid content by 39.3%and 21.4%,respectively,compared with that in the control(0-mmol/L Ala).Ala supplementation reduced photosynthetic activity while boosting respiratory activity and pyruvate levels,indicating that C.pyrenoidosa used exogenous Ala for biomass accumulation through the respiratory metabolic process.The accelerated respiratory metabolism due to Ala supplementation elevated the substrate pool and improved the lipogenic gene expression,promoting lipid production at last.This study provided a novel method for increasing biomass accumulation and lipid production and elucidated the role of Ala in regulating lipid production.
文摘Chlorella residues are currently underutilized. Therefore, in this study, we analyzed the nutritional components of Chlorella residue, and investigated its potential use as an organic fertilizer/bio-stimulant. Composition analyses revealed that the Chlorella residue contained a substantial amount of nitrogen (97,910 mg/kg), and significant quantities of secondary macronutrients, such as calcium (4300 mg/kg) and magnesium (9700 mg/kg), and micronutrients, such as iron (1850 mg/L) and manganese (359 mg/kg). The application of Chlorella residue to soil resulted in increased soil bacterial biomass. When Chlorella residue was added to the soil at a rate of 0.5% or 1.0% (w/w), the fresh weights of Brassica rapa and Spinacia oleracea were significantly increased. Furthermore, the application of Chlorella residue to the soil of B. rapa suppressed the reduction of the microbiome caused by clubroot disease and decreased the clubroot disease index. Therefore, Chlorella residue can be included in organic fertilizers that effectively improve soil nutrient contents, promote plant growth, and reduce the incidence of disease.
基金Supported by the High-level Talents Start-up Fund of Shihezi University(07002-500002061401)~~
文摘[Objective] The aim of this study is to isolate Chlorella vulgaris(chlorella)and extract its genomic DNA.[Method] Both the dilution method and drip method were employed to isolate chlorella from lake water samples;the conditions for culturing chlorella were optimized and its genomic DNA was extracted by improved CTAB method and SDS method.[Result] The proper conditions for chlorella culture were as following:temperature 20-25 ℃,illumination 4.39-5.86 W/m2 and rotational speed 100-150r/min;improved CTAB method was suitable for extracting genomic DNA from chlorella.[Conclusion] The study is helpful to study the chlorella at molecular level and promote the exploitation and utilization of chlorella resources.
基金Supported by Zhejiang Major Science and Technology Program(2008C12056)Zhejiang Science Innovation Plan for Undergraduate(2011R415023)~~
文摘[Objective] The aim was to investigate the effects of sound wave on propagation of Chlorella pyrenoidosa to explore the optimal frequency for Chlorella pyrenoidosa.[Method] In the research,Chlorella pyrenoidosa was cultured for 7 d with sound waves at different frequencies and a control group was set to study effects of sound wave at different frequencies on growth of Chlorella pyrenoidosa.[Result] Growth of Chlorella pyrenoidosa was significantly improved by sound wave,especially for wave at 400 Hz.[Conclusion] Chlorella pyrenoidosa propagation would be promoted by sound wave at certain frequencies.
基金Supported by Shenzhen Exclusive Funds for Developing Emerging Industries of Strategic Importance(CXZZ20120618111150009)~~
文摘[Objective] The aim was to research Chlorella properties in removing ni- trogen and phosphorus from wastewater. [Method] The effects of initial NH4＋-N and total P concentrations, N-to-P ratios, lightJdarkness ratios and pH on the removal of NH4＋-N and total P were evaluated. [Result] The results showed that Chlorella al- most removed NH4＋-N and total P at 100% as initial concentrations of NH4＋-N and total P were no more than 55 and 7 mg/L, respectively, whereas the removal ratio of NH4＋-N decreased to 90% with initial NH4＋-N concentration coming up to 75 mg/L. With N-to-P ratios of 5：1, 10：1 and 25：1, Chlorella completely removed NH4＋-N within 4 d, while the removal ratio of total P reached almost 100% within 7 d, with different N-to-P ratios. With L./D ratios of 24 h： 0 h and 12 h： 12 h as well as the initial concentrations of NH4＋-N at 30 mg/L and total P at 7 mg/L, the removing ra- tio of NH4＋-N and total P almost achieved 100% by Chlorella, and the removing ra- tio under L/D ratio of 24 h：0 h proved much faster. The optimal pH range for Chlorella to remove NH4＋-N and total P was 7-8. [Conclusion] The research pro- vides references for wastewater treatment in biological way and highly-efficient and environment-friendly treatment in future.
基金Support by a Grant from the Major State Basic Research Development Program of China(973 Program,2009CB724702)Science Foundation of Nanjing Industry University(39708010)~~
文摘[Objective] The aim was to study on the chlorella resistance to dehydration conditions and effect of different cryoprotecants on drying of chlorella cells.[Method]The protection effect of seven kinds of cryoprotecants on chlorella cells was analyzed.[Result]The protection effect of trehalose on chlorella cells was the best,and the survival rate of chlorella cells had improved by 50% with the applied trehalose concentration of 5%.[Conclusion]The result in this study had important guidance effect on the mutation breeding of chlorella.
基金Supported by Rural Area Project Application in the 12th Five-Year Period(2011BAD14B05)National Key Technology Research and Development Program(2012BAC18B01)Key Program for International S&T Cooperation Projects of China(2010DFB64040)~~
文摘The contamination reasons were analyzed form the viewpoints of strain preparation, air system, medium and equipment sterilization and pipeline configura- tion. Moreover, the contamination-preventing measures were defined. We also sum- marized the characteristics of bacteria that contaminated the fermentation, as well as checking methods and remedial measures.
文摘为了揭示二酰甘油酰基转移酶(DGAT)在小球藻油脂合成过程中的作用,对单细胞小球藻Chlorella variabilis NC64A的二酰甘油酰基转移酶进行原核克隆表达及功能初步研究。结果表明,其编码序列为894bp,编码297个氨基酸,表达蛋白的表观分子量为33 k Da,p I 9.48。保守结构域分析表明,该蛋白属于Lysophospholipid acyltransferases(LPLATs)超家族,具有二酰甘油酰基转移酶活性,序列位点H68,L71,F76,R94,I97和GAA(144?146)组成特定的酰基受体结合口袋,能够结合酰基?酰基载体蛋白(ACP)或者酰基辅酶A上的酰基,催化三酰甘油合成的最后一步。表达蛋白与Ss PDAT和At PDAT的序列相似性分别为32%和24%,表明该蛋白可能具有磷脂酰甘油酰基转移酶(PDAT)活性,能利用磷脂上的酰基合成三酰甘油。因此,采用薄层层析方法以L-α-磷脂酰胆碱和1,2-二油酰-sn-甘油为底物,检测到其确实具有PDAT活性,表明限氮条件下NC64A中DGAT的PDAT活性可能促进了膜脂降解耦合三酰甘油的合成。
基金Supported by National Natural Science Foundation of China (No:40206019)
文摘In the present study, genetic polymorphism and diversity in unicellular clones of Chlorella vulgaris Beijerinck and Chlorella pyrenoidosa Chick were studied with Inter Simple Sequence Repeats PCR （ISSR PCR）. Samples including four clones of C. vulgaris and three clones of C. pyrenoidosa were purified by single-clone-choice method. For four C. vulgaris unicellular clones, the total number of the bands scored for 18 primers was 298; and the number of the polymorphic bands was 118, of which 39.6% were polymorphic. The size of PCR products ranged from 200 to 2 500 bp. The total number of bands scored for 18 primers, the number of polymorphic bands and the percentage of three C. pyrenoidosa unicellular clones was 194.83 and 30.8%, respectively. POPGENE analysis show that the average Nei genetic diversity （h^＊） and Shannon index of diversity （I^＊） in the four C. vulgaris unicellular clones was 0.2181 and 0.3208, respectively, which is slightly higher than those of the three C. pyrenoidosa unicellular clones （0.190 3 and 0.274 8）, which agreed with the percentage of polymorphic bands in the mixed samples of the two species. The results suggest that ISSR is a useful method to Chlorella for intra-species genetic analysis.
文摘[Objective] This study was to realize high-density culture of Chlorella sp. as well as the culture with high lipid yield. [Method] Through analyzing the growth curve of Chlorella sp. cells, dextrose consumption curve, change curves of pH and dissolved oxygen, a fed-batch culture was conducted, followed by a nitrogen-deficient culture aiming at accumulating the lipids in Chlorella sp. cells when a high density of Chlorella sp. cells was obtained. [Result] After four batches of feeding were pro- vided, the biomass of Chlorella sp. reached up to 65.25 g/L, and the lipid content increased from 42.75% to 63.82% in Chlorella sp. cells, with the yield of 43.37 g/L in the following 12 hours of nitrogen-deficient culture. [Conclusion] Reasonable fed- batch can significantly improve the biomass of Chlorella sp., and the nitrogen-defi- cient culture further raises the lipid yield of Chlorella sp.
