Loofa sponge （LS） immobilized biomass of Chlorella sorokiniana （LSIBCS）, isolated from industrial wastewater, was investigated as a new biosorbent for the removal of Cr（Ⅲ） from aqueous solution. A comparison of...Loofa sponge （LS） immobilized biomass of Chlorella sorokiniana （LSIBCS）, isolated from industrial wastewater, was investigated as a new biosorbent for the removal of Cr（Ⅲ） from aqueous solution. A comparison of the biosorption of Cr（Ⅲ） by LSIBCS and free biomass of C. sorokiniana （FBCS） from 10-300 mg Cr（Ⅲ）/L aqueous solutions showed an increase in uptake of 17.79% when the microalgal biomass was immobilized onto loofa sponge. Maximum biosorption capacity for LSIBCS and FBCS was found to be 69.26 and 58.80 mg Cr（Ⅲ）/g biosorbent, respectively, whereas the amount of Cr（Ⅲ） ions adsorbed onto naked LS was 4.97 mg/g. The kinetics of Cr（Ⅲ） biosorption was extremely rapid and equilibrium was established in about 15 and 20 min by LSIBCS and FBCS, respectively. The biosorption equilibrium was well defined by Langmuir adsorption isotherm model. The biosorption kinetics followed the pseudo-second order kinetic model. The biosorption was found to be pH dependent and the maximum sorption occurred at the solution pH 4.0. Desorption studies showed that 98% of the adsorbed Cr（Ⅲ） could be desorbed with 0.1 mol/L HNO3, while other desorbing agents were less effective in the order： EDTA 〉 H2SO4 〉 CH3COOH 〉 HCl. The regenerated LSIBCS retained 92.68% of the initial Cr（Ⅲ） binding capacity up to five cycles of reuse in continuous flow-fixed bed columns. The study revealed that LSIBCS could be used as an effective biosorbent for the removal of Cr（Ⅲ） from wastewater.展开更多
To study the abilities of Chlorella sorokiniana CS-01 on using CO2 from flue gases to produce biodiesel,the microaglae was cultured with different simulated flue gases containing 5%-15%(volume fraction) of CO2.The res...To study the abilities of Chlorella sorokiniana CS-01 on using CO2 from flue gases to produce biodiesel,the microaglae was cultured with different simulated flue gases containing 5%-15%(volume fraction) of CO2.The results show that strain CS-01 could grow at 15% CO2 and grow well under CO2 contents ranging from 5%-10%.The maximal biomass productivity and lipid productivity were obtained when aerating with 10% of CO2.The lipids content ranged from 28% to 43% of dry mass of biomass.The main fatty acid compositions of strain CS-01 were C14-C18(>72%) short-chain FAMEs(known as biodiesel feedstocks).Meanwhile,the biodiesel productivity was over 60%,suggesting that Chlorella sorokiniana CS-01 has a great potential for CO2 mitigation and biodiesel production.Furthermore,differential expression of three genes related to CO2 fixation and fatty acid synthesis were studied to further describe the effect of simulated flue gases on the growth and lipid accumulation of strain CS-01 at molecular level.展开更多
Microalgae,a sustainable source of multi beneficial components has been discovered and could be utilised in pharmaceutical,bioenergy and food applications.This study aims to investigate the sugaring-out effect on the ...Microalgae,a sustainable source of multi beneficial components has been discovered and could be utilised in pharmaceutical,bioenergy and food applications.This study aims to investigate the sugaring-out effect on the recovery of protein from wet green microalga,Chlorella sorokiniana CY1 which was assisted with sonication.A comparison of monosaccharides and disaccharides as one of the phaseforming constituents shows that the monosaccharides,glucose was the most suitable sugar in forming the phases with acetonitrile to enhance the production of protein(52% of protein).The protein productivity of microalgae was found to be significantly influenced by the volume ratio of both phases,as the yield of protein increased to 77%.The interval time between the sonication as well as the sonication modes were influencing the protein productivity as well.The optimum protein productivity was obtained with 10s of resting time in between sonication.Pulse mode of sonication was suitable to break down the cell wall of microalgae compared to continuous mode as a lower protein yield was obtained with the application of continuous mode.The optimum condition for protein extraction were found as followed:200g/L glucose as bottom phase with volume ratio of 1:1.25,10s of resting time for ultrasonication,5s of ultrasonication in pulse mode and 0.25g of biomass weight.The high yield of protein about 81% could be obtained from microalgae which demonstrates the potential of this source and expected to play an important role in the future.展开更多
Nitrogen (N) and sulphur (S), being essential macronutrients, have important roles in microalgae metabolism. Effects of N- or S-shortage were investigated in the green microalgae Chlorella sorokiniana subjected to 24 ...Nitrogen (N) and sulphur (S), being essential macronutrients, have important roles in microalgae metabolism. Effects of N- or S-shortage were investigated in the green microalgae Chlorella sorokiniana subjected to 24 h of starvation, by measuring the glutamine synthetase (GS) and O-ace- tylserine(thiol)lyase (OASTL) activities, proteins and amino acids levels. To test possible metabolic impact related to carbon (C) metabolism in response to N- or S-deprivation, starch and total C, N and S contents were also determined. The growth of C. sorokiniana cells was affected by N or S availability. The algae cultured for 24 h in a medium deprived of nitrogen or sulphur showed a decrease in the growth rate and changes in the average volume cell. Nitrogen starvation affected proteins level in the algae cells more than S-deprivation did. The decline in the protein levels observed under S-deficient conditions was coupled with the accumulation of the amide glutamine and with OASTL activity increase;additionally, N-deficiency promoted a decrease in cysteine (Cys) levels (50%) and an increase in GS activity. Nevertheless, S-deprivation had negligible effects on GS activity, while N-deprivation significantly affected OASTL activity. Total C was also estimated in cells N- or S-deprived;nitrogen deprivation strongly affected total C content more than S-deprivation, which in addition reduced the content of C and N, but leaves intact their ratios. Our results support the hypothesis that in Chlorella sorokiniana cells a reciprocal influence of N, S and C assimilation occurs.展开更多
Aiming to investigate the impact of different stocking densities on the ability of Pacific white shrimp(Litopenaeus vannamei)to utilize Chlorella sorokiniana(CHL),a 3×2 factorial design stocking experiment was us...Aiming to investigate the impact of different stocking densities on the ability of Pacific white shrimp(Litopenaeus vannamei)to utilize Chlorella sorokiniana(CHL),a 3×2 factorial design stocking experiment was used in this study.Specifically,shrimp was fed with two dietary protein sources(fishmeal[FM]and CHL)at low(LSD;100 per m^(3)),medium(MSD;200 per m^(3))and high(HSD;300 per m^(3))stocking densities for 8 weeks.The growth performance and resistance to Vibrio parahaemolyticus(1.0×10^(7) CFU/mL)of shrimp decreased with the increase of stocking density,but dietary CHL improved this result.Differences between the CHL and FM groups for V.parahaemolyticus resistance were significant only under high-density conditions(P<0.05).Significant interactions between stocking density and protein source were found on the activities of catalase(CAT),superoxide dismutase(SOD)and phenol oxidase(PO),and the contents of malondialdehyde(MDA)in the hepatopancreas and the activities of intestinal amylase,most of which were significantly different between CHL and FM groups only at high stocking density(P<0.05).Analysis of 16S rDNA sequencing showed that dietary CHL increased the alpha diversity of intestinal microbiota,inhibited the colonization of pathogenic bacteria and enhanced the abundance of beneficial bacteria.Transcriptomic results showed that at high stocking densities,differentially expressed genes(DEGs)in the FM vs CHL group were mostly upregulated and primarily enriched in immune and metabolic related pathways including Toll,immune deficiency(Imd)and glycolysis–gluconeogenesis pathways.Pearson correlation analysis revealed significant correlation between the top ten intestinal bacteria at the genus level and markedly enriched DEGs,also more were detected under high density situations.In conclusion,CHL has great potential as a novel protein source in the intensive farming of shrimp.展开更多
文摘Loofa sponge （LS） immobilized biomass of Chlorella sorokiniana （LSIBCS）, isolated from industrial wastewater, was investigated as a new biosorbent for the removal of Cr（Ⅲ） from aqueous solution. A comparison of the biosorption of Cr（Ⅲ） by LSIBCS and free biomass of C. sorokiniana （FBCS） from 10-300 mg Cr（Ⅲ）/L aqueous solutions showed an increase in uptake of 17.79% when the microalgal biomass was immobilized onto loofa sponge. Maximum biosorption capacity for LSIBCS and FBCS was found to be 69.26 and 58.80 mg Cr（Ⅲ）/g biosorbent, respectively, whereas the amount of Cr（Ⅲ） ions adsorbed onto naked LS was 4.97 mg/g. The kinetics of Cr（Ⅲ） biosorption was extremely rapid and equilibrium was established in about 15 and 20 min by LSIBCS and FBCS, respectively. The biosorption equilibrium was well defined by Langmuir adsorption isotherm model. The biosorption kinetics followed the pseudo-second order kinetic model. The biosorption was found to be pH dependent and the maximum sorption occurred at the solution pH 4.0. Desorption studies showed that 98% of the adsorbed Cr（Ⅲ） could be desorbed with 0.1 mol/L HNO3, while other desorbing agents were less effective in the order： EDTA 〉 H2SO4 〉 CH3COOH 〉 HCl. The regenerated LSIBCS retained 92.68% of the initial Cr（Ⅲ） binding capacity up to five cycles of reuse in continuous flow-fixed bed columns. The study revealed that LSIBCS could be used as an effective biosorbent for the removal of Cr（Ⅲ） from wastewater.
基金Project(50621063) supported by the National Natural Science Foundation for Distinguished Group of ChinaProjects(2010bsxt05,2010ssxt246) supported by the Innovation Foundation of Science and Technology of Central South University,China
文摘To study the abilities of Chlorella sorokiniana CS-01 on using CO2 from flue gases to produce biodiesel,the microaglae was cultured with different simulated flue gases containing 5%-15%(volume fraction) of CO2.The results show that strain CS-01 could grow at 15% CO2 and grow well under CO2 contents ranging from 5%-10%.The maximal biomass productivity and lipid productivity were obtained when aerating with 10% of CO2.The lipids content ranged from 28% to 43% of dry mass of biomass.The main fatty acid compositions of strain CS-01 were C14-C18(>72%) short-chain FAMEs(known as biodiesel feedstocks).Meanwhile,the biodiesel productivity was over 60%,suggesting that Chlorella sorokiniana CS-01 has a great potential for CO2 mitigation and biodiesel production.Furthermore,differential expression of three genes related to CO2 fixation and fatty acid synthesis were studied to further describe the effect of simulated flue gases on the growth and lipid accumulation of strain CS-01 at molecular level.
基金Supported by the University of Malaya,Kuala Lumpur,Malaysia under SATU joint research scheme(No.ST004-2017)the International Cooperation Seeds Funding of Nanjing Agricultural University(No.2018-AH-04)
文摘Microalgae,a sustainable source of multi beneficial components has been discovered and could be utilised in pharmaceutical,bioenergy and food applications.This study aims to investigate the sugaring-out effect on the recovery of protein from wet green microalga,Chlorella sorokiniana CY1 which was assisted with sonication.A comparison of monosaccharides and disaccharides as one of the phaseforming constituents shows that the monosaccharides,glucose was the most suitable sugar in forming the phases with acetonitrile to enhance the production of protein(52% of protein).The protein productivity of microalgae was found to be significantly influenced by the volume ratio of both phases,as the yield of protein increased to 77%.The interval time between the sonication as well as the sonication modes were influencing the protein productivity as well.The optimum protein productivity was obtained with 10s of resting time in between sonication.Pulse mode of sonication was suitable to break down the cell wall of microalgae compared to continuous mode as a lower protein yield was obtained with the application of continuous mode.The optimum condition for protein extraction were found as followed:200g/L glucose as bottom phase with volume ratio of 1:1.25,10s of resting time for ultrasonication,5s of ultrasonication in pulse mode and 0.25g of biomass weight.The high yield of protein about 81% could be obtained from microalgae which demonstrates the potential of this source and expected to play an important role in the future.
文摘Nitrogen (N) and sulphur (S), being essential macronutrients, have important roles in microalgae metabolism. Effects of N- or S-shortage were investigated in the green microalgae Chlorella sorokiniana subjected to 24 h of starvation, by measuring the glutamine synthetase (GS) and O-ace- tylserine(thiol)lyase (OASTL) activities, proteins and amino acids levels. To test possible metabolic impact related to carbon (C) metabolism in response to N- or S-deprivation, starch and total C, N and S contents were also determined. The growth of C. sorokiniana cells was affected by N or S availability. The algae cultured for 24 h in a medium deprived of nitrogen or sulphur showed a decrease in the growth rate and changes in the average volume cell. Nitrogen starvation affected proteins level in the algae cells more than S-deprivation did. The decline in the protein levels observed under S-deficient conditions was coupled with the accumulation of the amide glutamine and with OASTL activity increase;additionally, N-deficiency promoted a decrease in cysteine (Cys) levels (50%) and an increase in GS activity. Nevertheless, S-deprivation had negligible effects on GS activity, while N-deprivation significantly affected OASTL activity. Total C was also estimated in cells N- or S-deprived;nitrogen deprivation strongly affected total C content more than S-deprivation, which in addition reduced the content of C and N, but leaves intact their ratios. Our results support the hypothesis that in Chlorella sorokiniana cells a reciprocal influence of N, S and C assimilation occurs.
基金supported by the Special Projects in Key Fields of Ordinary University in Guangdong Province (2023ZDZX4010)General Program of Natural Science Foundation of Guangdong Province,China (Grant No.2022A 1515012325)Postgraduate Education Innovation Project of Guangdong Ocean University in 2023 (Grant No.202336).
文摘Aiming to investigate the impact of different stocking densities on the ability of Pacific white shrimp(Litopenaeus vannamei)to utilize Chlorella sorokiniana(CHL),a 3×2 factorial design stocking experiment was used in this study.Specifically,shrimp was fed with two dietary protein sources(fishmeal[FM]and CHL)at low(LSD;100 per m^(3)),medium(MSD;200 per m^(3))and high(HSD;300 per m^(3))stocking densities for 8 weeks.The growth performance and resistance to Vibrio parahaemolyticus(1.0×10^(7) CFU/mL)of shrimp decreased with the increase of stocking density,but dietary CHL improved this result.Differences between the CHL and FM groups for V.parahaemolyticus resistance were significant only under high-density conditions(P<0.05).Significant interactions between stocking density and protein source were found on the activities of catalase(CAT),superoxide dismutase(SOD)and phenol oxidase(PO),and the contents of malondialdehyde(MDA)in the hepatopancreas and the activities of intestinal amylase,most of which were significantly different between CHL and FM groups only at high stocking density(P<0.05).Analysis of 16S rDNA sequencing showed that dietary CHL increased the alpha diversity of intestinal microbiota,inhibited the colonization of pathogenic bacteria and enhanced the abundance of beneficial bacteria.Transcriptomic results showed that at high stocking densities,differentially expressed genes(DEGs)in the FM vs CHL group were mostly upregulated and primarily enriched in immune and metabolic related pathways including Toll,immune deficiency(Imd)and glycolysis–gluconeogenesis pathways.Pearson correlation analysis revealed significant correlation between the top ten intestinal bacteria at the genus level and markedly enriched DEGs,also more were detected under high density situations.In conclusion,CHL has great potential as a novel protein source in the intensive farming of shrimp.
