The biological activity of plant polysaccharides can be enhanced by sulfated modification.In this study,the immunomodulatory effect of sulfated Cyclocarya paliurus polysaccharides(SCP3)on macrophages RAW264.7 and its ...The biological activity of plant polysaccharides can be enhanced by sulfated modification.In this study,the immunomodulatory effect of sulfated Cyclocarya paliurus polysaccharides(SCP3)on macrophages RAW264.7 and its potential molecular mechanism were investigated.Results showed that SCP3 at 25-100μg/m L increased viability and improved phagocytosis of RAW264.7 cells.Meanwhile,SCP3 could activate mitogen-activated protein kinase(MAPK)and nuclear factor kappa B(NF-κB)signaling pathways,which increased the phosphorylation of Erk1/2,JNK,p38 and NF-κB p65,promoting secretion of cytokines tumor necrosis factorα(TNF-α),interleukin 6(IL-6)and nitric oxide(NO)as well as the production of reactive oxygen species(ROS).In addition,Toll-like receptor 4(TLR4)receptor inhibitors were able to block the production of NO and TNF-αby SCP3-stimulated macrophages.Based on Western blot analysis and validation using specific inhibitors against MAPK and NF-κB signaling pathways,the results demonstrated that SCP3 induced macrophages activation and enhanced TNF-αand NO production via TLR4-mediated MAPK and NF-κB pathways.In summary,SCP3 has significant immunomodulatory potential.The underlying molecular mechanism was that SCP3 activates macrophages via TLR4 receptors to promote ROS production,which in turn activates the downstream MAPK/NF-κB signaling pathway and then increases the secretion levels of cytokines and NO.展开更多
Sea cucumber is a traditional nutritional food and medicinal resource with many bioactive components in China.Holothuria fuscogliva is a big sea cucumber with a rich of bioactive polysaccharides.To investigate the bio...Sea cucumber is a traditional nutritional food and medicinal resource with many bioactive components in China.Holothuria fuscogliva is a big sea cucumber with a rich of bioactive polysaccharides.To investigate the bioactivities of the polysaccharides from sea cucumber H.fuscogliva,we prepared the sulfated polysaccharides(HfP) from sea cucumber H.fuscogliva using a protease hydrolysis method.Antioxidant activities of HfP were investigated,including hydroxyl radical scavenging activity and superoxide radical scavenging activity.And,the anticoagulant activities of HfP were studied,including the activated partial thromboplastin time(APTT),prothrombin time(PT) and thrombin time(TT).The average molecular weight was 1 867.1 Da,with a sulfate content of 20.7%.In addition,the molar ratio of monosaccharide composition of HfP was Man:Rha:Glc A:Glc:Gal:Xyl:Fuc=0.083 6:0.437:0.134:0:1.182:0.748:1.It had a strong antioxidant activity,the hydroxyl and superoxide radical scavenging activity EC_(50) of HfP was 3.74 and 0.037 mg/mL,respectively.It also showed a good anticoagulant activity in our study.The APTT of HfP was much higher than that of heparin sodium,and the PT and TT of HfP was close to that of heparin sodium at a low concentration.Therefore,HfP shows a good antioxidant and anticoagulant activity and it may become a potential candidate of the natural antioxidant and anticoagulant and will have a good application future in health product or medicine industry.展开更多
Two sulfated polysaccharides, designated MP and SP, were extracted from the marine green alga Enteromorpha linza using hot water and then purified using ion-exchange and size-exclusion chromatography. The anticoagulan...Two sulfated polysaccharides, designated MP and SP, were extracted from the marine green alga Enteromorpha linza using hot water and then purified using ion-exchange and size-exclusion chromatography. The anticoagulant activities of MP and SP were examined by determination of their activated partial thromboplastin time (APTT), thrombin time (TT) and prothrombin time (PT) using human plasma. Results showed that MP and SP were composed of abundant rhamnose with small amounts of xylose and glucuronic acid, whereas SP also contained a small amount of galactose. Approximate molecular weights of MP and SP were 535 and 502 kDa, respectively. As compared with SP, MP had higher contents of sulfate ester (19.0%) and uronic acid (14.9%). The MP mainly consisted of (1→4)-linked rhamnose residues with partially sulfated groups at the C-3 position, and small amounts of (1→3, 4)-linked rhamnose, (1→2, 4)-linked rhamnose, (1→4)-linked glucuronic acid and (1→4)-linked xylose residues. The SP contained abundant (1→4)-linked rhamnose with minor amounts of (1→3)-linked rhamnose, (1→3, 4)-linked rhamnose, (1→2, 4)-linked rhamnose, (1→4)-linked glucuronic acid, (1→4)-linked xylose, and (1→3)-linked galactose residues. The sulfate groups were mainly located at C-3 of (1→4)-linked rhamnose residues. Both MP and SP, in particular the former, effectively prolonged APTT and TT. This work demonstrates that MP and SP have unique structural characteristics distinct from those of other sulfated polysaccharides from Enteromorpha. The MP is a potential source of anticoagulant, and the difference in anticoagulant activities of the two sulfated polysaccharides is directly linked to the discrepancy of their chemical features.展开更多
In this paper, in vitro anti-influenza virus activities of sulfated polysaccharide fractions from Gracilaria lemaneiformis were investigated. Cytotoxicities and antiviral activities of Gracilaria lemaneiformis polysac...In this paper, in vitro anti-influenza virus activities of sulfated polysaccharide fractions from Gracilaria lemaneiformis were investigated. Cytotoxicities and antiviral activities of Gracilaria lemaneiformis polysaccharides (PGL), Gracilaria lemaneiformis polysaccharide fraction-1 (GL-1), Gracilaria lemaneiformis polysaccharide fraction-2 (GL-2) and Gracilaria lemaneiformis polysaccharide fraction-3 (GL-3) were studied by the Methyl thiazolyl tetrazolium (MTT) method, and the inhibitory effect against Human influenza virus H1-364 induced cytopathic effect (CPE) on MDCK cells were observed by the CPE method. In addition, the antiviral mechanism of PGL was explored by Plaque forming unit (PFU), MTT and CPE methods. The results showed: i) Cytotoxicities were not significantly revealed, and H1-364 induced CPE was also reduced treated with sulfated polysaccharide fractions from Gracilaria lemaneiformis; ii) Antiviral activities were associated with the mass percentage content of sulfate groups in polysaccharide fractions, which was about 13%, in polysaccharides (PGL and GL-2) both of which exhibited higher antiviral activity; iii) A potential antiviral mechanism to explain these observations is that viral adsorption and replication on host cells were inhibited by sulfated polysaccharides from Gracilaria lemaneiformis. In conclusion, Anti-influenza virus activities of sulfated polysaccharide fractions from Gracilaria lemaneiformis were revealed, and the antiviral activities were associated with content of sulfate groups in polysaccharide fractions.展开更多
The influence of sulfated polysaccharide (SPS) isolated from marine algae Sargassum fusiforme on the morphology and phase compositions of urinary crystal calcium oxalate was investigated in vitro by means of scannin...The influence of sulfated polysaccharide (SPS) isolated from marine algae Sargassum fusiforme on the morphology and phase compositions of urinary crystal calcium oxalate was investigated in vitro by means of scanning electron microscopy and X-ray diffraction. SPS maybe is a potential inhibitor to CaOxa urinary stones by inhibiting the growth of calcium oxalate monohydrate (COM), preventing the aggregation of COM, and inducing the formation of calcium oxalate dihydrate (COD) crystals.展开更多
A rapid,sensitive and reproducible high performance liquid chromatography(HPLC) method with post-column fluorescence derivatization has been developed to determine the amount of low-molecularweight sulfated polysaccha...A rapid,sensitive and reproducible high performance liquid chromatography(HPLC) method with post-column fluorescence derivatization has been developed to determine the amount of low-molecularweight sulfated polysaccharide(GFS) in vivo. The metabolism of GFS has been shown to fit a two component model following its administration by intravenous injection,and its pharmacokinetic parameters were determined to be as follows: half-time of distribution phase(t_(1/2α))=11.24±2.93 min,half-time of elimination phase(t_(1/2β))=98.20±25.78 min,maximum concentration(C_(max))=110.53 μg/mL and peak time(T_(max))=5 min. The pharmacokinetic behavior of GFS was also investigated following intragastric administration. However,the concentration of GFS found in serum was too low for detection,and GFS could only be detected for up to 2 h after intragastric administration(200 mg/kg body weight). Thus,the bioavailability of GFS was low following intragastric administration because of the metabolism of GFS. In conclusion,HPLC with postcolumn derivatization could be used for quantitative microanalysis and pharmacokinetic studies to determine the presence of polysaccharides in the serum following intravenous injection.展开更多
There are also a variety of cytokines in the tumor microenvironment,which are involved in the change in the hardness of the tumor,thereby affecting the invasion and metastasis of tumor cells.As traditional Chinese med...There are also a variety of cytokines in the tumor microenvironment,which are involved in the change in the hardness of the tumor,thereby affecting the invasion and metastasis of tumor cells.As traditional Chinese medicines,drugs of softening and dissipating firm knot contains different kinds of sulfated polysaccharide and sulfated glycopeptide.By inhibiting the function of cancer-associated fibroblasts,they reduce interstitial fibrosis,thereby reducing the hardness of the tumor and exerting an anti-tumor effect.展开更多
Objective:To investigate the effects of pectic polysaccharides extracted from Rauwolfia verticillata(Lour.) Baill.var.hainanensis Tsiang on an experimental murine colitis model.Methods:Experimental colitis was induced...Objective:To investigate the effects of pectic polysaccharides extracted from Rauwolfia verticillata(Lour.) Baill.var.hainanensis Tsiang on an experimental murine colitis model.Methods:Experimental colitis was induced by dextran sulfate sodium(DSS),and mice were divided into 4 groups:control.DSS alone.DSS plus SASP,DSS plus pectic polysaccharides.The disease activity index(DAI) and histological score were observed.The tumor necrosis factor(TNF)-α and interleukin(IL)-17 levels were measured by enzyme-linked immunosorbent assay.I κ B and NF-κB p65 expression were assessed by western blot analysis.Myeloperoxidase(MPO) activity was determined by using MPO assay kit.Re.sults:Administration of pectic polysaccharides significantly reduced the severity of DSS-induced colitis as assessed by DAT and histological score,and resulted in down regulation of MPO activity and NF-κB p65 expression and subsequent degradation of IκB protein,strikingly reduced the production of TNF-α and IL-17.Conclusions:Pectic polysaccharides extracted from Rauvolfia verticillata(Lour.)Baill.var.hainanensis Tsiang exerts beneficial effects in experimental colitis and may therefore provide a useful therapeutic approach for the treatment of UC.展开更多
Twenty-seven antarctic bacteria producing extracellular polysaccharide (EPS) were selected from 57 strains by staining technology. The effects of major environmental factors on the growth and EPS production of Pseud...Twenty-seven antarctic bacteria producing extracellular polysaccharide (EPS) were selected from 57 strains by staining technology. The effects of major environmental factors on the growth and EPS production of Pseudoalteromonas sp. S - 15 - 13 were investigated, and the EPS was separated and purified for characterization analysis. The results showed that the optimal conditions for the EPS production were culture period, 56 h; growth temperature, 8 ℃ ; carbon source, 1.0% glucose; NaCI concentration, 3.0% ; pH 6.0 - 7.0. The EPS was purified by cold ethanol precipitation, proteins removal, ion exchange chromatography and gel chromatography technology. The molecular mass of EPS - H was 62 kDa as determined by the high performance gel permeation chromatography. Its sugar composition was a homopolymer of marmose analyzed by gas chromatograph spectroscopy. After repeated freezing and thawing of the bacteria hiomass in the presence of EPS, the bacterial growth was much higher than that observed after freezing in the absence of EPS and the difference augmented with the increase of freeze-thaw cycles. It is hypothesized that the adaptation of Pseudoalteromonas sp. S- 15 - 13 to the antarctic marine conditions, characterized by low temperature, high NaCl concentration and repeated freeze-thaw cycles, might be related to the EPS production ability.展开更多
The use of high alkaline medium is a feasible way to provide carbon source and prevent biological contamination for the outdoor cultivation of alkaliphilic microalgae and cyanobacteria.A novel cyanobacterial strain wa...The use of high alkaline medium is a feasible way to provide carbon source and prevent biological contamination for the outdoor cultivation of alkaliphilic microalgae and cyanobacteria.A novel cyanobacterial strain was isolated from the open pond of a marine green alga(Picochlorum sp.SCSIO-45015,Sanya,Hainan)and identified as Cyanobacterium sp.SCSIO-45682.The effects of initial sodium bicarbonate(NaHCO_(3))concentrations on the growth and biochemical composition of Cyanobacterium sp.SCSIO-45682 were investigated.The results demonstrated that Cyanobacterium sp.SCSIO-45682 had good adaptation to 16.8-g/L NaHCO_(3)(the same concentration of NaHCO_(3) used in Zarrouk medium for Spirulina).Moreover,the yields of biomass,polysaccharide,chlorophyll a(chl a),and phycocyanin increased under high NaHCO_(3) concentrations.The maximum final biomass concentration of 2.5 g/L was observed at 8.4-g/L NaHCO_(3),while the highest intracellular total saccharide content of 49.2%of dry weight(DW)and exopolysaccharide(EPS)concentration of 93 mg/L were achieved at the NaHCO_(3) concentration of 16.8 g/L.The crude protein content declined under high NaHCO_(3) concentrations,which provide a possible explanation for the accumulation of polysaccharide.This study shows a good potential of alkaliphilic Cyanobacterium sp.SCSIO-45682 as a polysaccharide feedstock.展开更多
基金the financial supports by the National Natural Science Foundation of China(82060594)the Natural Science Foundation of Jiangxi Province,China(20202BAB205006)。
文摘The biological activity of plant polysaccharides can be enhanced by sulfated modification.In this study,the immunomodulatory effect of sulfated Cyclocarya paliurus polysaccharides(SCP3)on macrophages RAW264.7 and its potential molecular mechanism were investigated.Results showed that SCP3 at 25-100μg/m L increased viability and improved phagocytosis of RAW264.7 cells.Meanwhile,SCP3 could activate mitogen-activated protein kinase(MAPK)and nuclear factor kappa B(NF-κB)signaling pathways,which increased the phosphorylation of Erk1/2,JNK,p38 and NF-κB p65,promoting secretion of cytokines tumor necrosis factorα(TNF-α),interleukin 6(IL-6)and nitric oxide(NO)as well as the production of reactive oxygen species(ROS).In addition,Toll-like receptor 4(TLR4)receptor inhibitors were able to block the production of NO and TNF-αby SCP3-stimulated macrophages.Based on Western blot analysis and validation using specific inhibitors against MAPK and NF-κB signaling pathways,the results demonstrated that SCP3 induced macrophages activation and enhanced TNF-αand NO production via TLR4-mediated MAPK and NF-κB pathways.In summary,SCP3 has significant immunomodulatory potential.The underlying molecular mechanism was that SCP3 activates macrophages via TLR4 receptors to promote ROS production,which in turn activates the downstream MAPK/NF-κB signaling pathway and then increases the secretion levels of cytokines and NO.
基金Supported by the Science and Technology Service Network Program of Chinese Academy of Sciences(No.KFJ-EW-STS-060)the National Special Research Fund for Non-Profit Marine Sector(No.201405038-2)+1 种基金the Scientific and Technological Innovation ProjectFinancially Supported by Qingdao National Laboratory for Marine Science and Technology(No.2015ASKJ02)
文摘Sea cucumber is a traditional nutritional food and medicinal resource with many bioactive components in China.Holothuria fuscogliva is a big sea cucumber with a rich of bioactive polysaccharides.To investigate the bioactivities of the polysaccharides from sea cucumber H.fuscogliva,we prepared the sulfated polysaccharides(HfP) from sea cucumber H.fuscogliva using a protease hydrolysis method.Antioxidant activities of HfP were investigated,including hydroxyl radical scavenging activity and superoxide radical scavenging activity.And,the anticoagulant activities of HfP were studied,including the activated partial thromboplastin time(APTT),prothrombin time(PT) and thrombin time(TT).The average molecular weight was 1 867.1 Da,with a sulfate content of 20.7%.In addition,the molar ratio of monosaccharide composition of HfP was Man:Rha:Glc A:Glc:Gal:Xyl:Fuc=0.083 6:0.437:0.134:0:1.182:0.748:1.It had a strong antioxidant activity,the hydroxyl and superoxide radical scavenging activity EC_(50) of HfP was 3.74 and 0.037 mg/mL,respectively.It also showed a good anticoagulant activity in our study.The APTT of HfP was much higher than that of heparin sodium,and the PT and TT of HfP was close to that of heparin sodium at a low concentration.Therefore,HfP shows a good antioxidant and anticoagulant activity and it may become a potential candidate of the natural antioxidant and anticoagulant and will have a good application future in health product or medicine industry.
基金supported by the National Natural Science Foundation of China (No.41076086)the National Oceanographic Center of Qingdao, China and the Science and Technology Development Program of Shandong Province, China (No.2010GHY10509)
文摘Two sulfated polysaccharides, designated MP and SP, were extracted from the marine green alga Enteromorpha linza using hot water and then purified using ion-exchange and size-exclusion chromatography. The anticoagulant activities of MP and SP were examined by determination of their activated partial thromboplastin time (APTT), thrombin time (TT) and prothrombin time (PT) using human plasma. Results showed that MP and SP were composed of abundant rhamnose with small amounts of xylose and glucuronic acid, whereas SP also contained a small amount of galactose. Approximate molecular weights of MP and SP were 535 and 502 kDa, respectively. As compared with SP, MP had higher contents of sulfate ester (19.0%) and uronic acid (14.9%). The MP mainly consisted of (1→4)-linked rhamnose residues with partially sulfated groups at the C-3 position, and small amounts of (1→3, 4)-linked rhamnose, (1→2, 4)-linked rhamnose, (1→4)-linked glucuronic acid and (1→4)-linked xylose residues. The SP contained abundant (1→4)-linked rhamnose with minor amounts of (1→3)-linked rhamnose, (1→3, 4)-linked rhamnose, (1→2, 4)-linked rhamnose, (1→4)-linked glucuronic acid, (1→4)-linked xylose, and (1→3)-linked galactose residues. The sulfate groups were mainly located at C-3 of (1→4)-linked rhamnose residues. Both MP and SP, in particular the former, effectively prolonged APTT and TT. This work demonstrates that MP and SP have unique structural characteristics distinct from those of other sulfated polysaccharides from Enteromorpha. The MP is a potential source of anticoagulant, and the difference in anticoagulant activities of the two sulfated polysaccharides is directly linked to the discrepancy of their chemical features.
基金The Science and Technology Projects of Guangdong (2009B020312012)The Science and Technology Projects of Shantou (2008-143)
文摘In this paper, in vitro anti-influenza virus activities of sulfated polysaccharide fractions from Gracilaria lemaneiformis were investigated. Cytotoxicities and antiviral activities of Gracilaria lemaneiformis polysaccharides (PGL), Gracilaria lemaneiformis polysaccharide fraction-1 (GL-1), Gracilaria lemaneiformis polysaccharide fraction-2 (GL-2) and Gracilaria lemaneiformis polysaccharide fraction-3 (GL-3) were studied by the Methyl thiazolyl tetrazolium (MTT) method, and the inhibitory effect against Human influenza virus H1-364 induced cytopathic effect (CPE) on MDCK cells were observed by the CPE method. In addition, the antiviral mechanism of PGL was explored by Plaque forming unit (PFU), MTT and CPE methods. The results showed: i) Cytotoxicities were not significantly revealed, and H1-364 induced CPE was also reduced treated with sulfated polysaccharide fractions from Gracilaria lemaneiformis; ii) Antiviral activities were associated with the mass percentage content of sulfate groups in polysaccharide fractions, which was about 13%, in polysaccharides (PGL and GL-2) both of which exhibited higher antiviral activity; iii) A potential antiviral mechanism to explain these observations is that viral adsorption and replication on host cells were inhibited by sulfated polysaccharides from Gracilaria lemaneiformis. In conclusion, Anti-influenza virus activities of sulfated polysaccharide fractions from Gracilaria lemaneiformis were revealed, and the antiviral activities were associated with content of sulfate groups in polysaccharide fractions.
基金granted by the National Natural Science Foundation of China(20471024)the Project-sponsored by SRF for ROCS,SEMthe Key project of Natural Science Foundation of China(20031010).
文摘The influence of sulfated polysaccharide (SPS) isolated from marine algae Sargassum fusiforme on the morphology and phase compositions of urinary crystal calcium oxalate was investigated in vitro by means of scanning electron microscopy and X-ray diffraction. SPS maybe is a potential inhibitor to CaOxa urinary stones by inhibiting the growth of calcium oxalate monohydrate (COM), preventing the aggregation of COM, and inducing the formation of calcium oxalate dihydrate (COD) crystals.
基金Supported by the National Natural Science Foundation of China(No.41376166)the Ocean Public Welfare Scientific Research Project(Nos.201005024,201405040)+1 种基金the Jiangsu Science and Technology Project(No.BE2012687)the Special Fund for Cooperation between Jilin Province and Chinese Academy of Sciences(No.2013SYHZ0023)
文摘A rapid,sensitive and reproducible high performance liquid chromatography(HPLC) method with post-column fluorescence derivatization has been developed to determine the amount of low-molecularweight sulfated polysaccharide(GFS) in vivo. The metabolism of GFS has been shown to fit a two component model following its administration by intravenous injection,and its pharmacokinetic parameters were determined to be as follows: half-time of distribution phase(t_(1/2α))=11.24±2.93 min,half-time of elimination phase(t_(1/2β))=98.20±25.78 min,maximum concentration(C_(max))=110.53 μg/mL and peak time(T_(max))=5 min. The pharmacokinetic behavior of GFS was also investigated following intragastric administration. However,the concentration of GFS found in serum was too low for detection,and GFS could only be detected for up to 2 h after intragastric administration(200 mg/kg body weight). Thus,the bioavailability of GFS was low following intragastric administration because of the metabolism of GFS. In conclusion,HPLC with postcolumn derivatization could be used for quantitative microanalysis and pharmacokinetic studies to determine the presence of polysaccharides in the serum following intravenous injection.
文摘There are also a variety of cytokines in the tumor microenvironment,which are involved in the change in the hardness of the tumor,thereby affecting the invasion and metastasis of tumor cells.As traditional Chinese medicines,drugs of softening and dissipating firm knot contains different kinds of sulfated polysaccharide and sulfated glycopeptide.By inhibiting the function of cancer-associated fibroblasts,they reduce interstitial fibrosis,thereby reducing the hardness of the tumor and exerting an anti-tumor effect.
基金supported by National Natural Science Foundation of China(Grant No.81360603)Natural Science Foundation of Hainan Province(Grant No.813215)
文摘Objective:To investigate the effects of pectic polysaccharides extracted from Rauwolfia verticillata(Lour.) Baill.var.hainanensis Tsiang on an experimental murine colitis model.Methods:Experimental colitis was induced by dextran sulfate sodium(DSS),and mice were divided into 4 groups:control.DSS alone.DSS plus SASP,DSS plus pectic polysaccharides.The disease activity index(DAI) and histological score were observed.The tumor necrosis factor(TNF)-α and interleukin(IL)-17 levels were measured by enzyme-linked immunosorbent assay.I κ B and NF-κB p65 expression were assessed by western blot analysis.Myeloperoxidase(MPO) activity was determined by using MPO assay kit.Re.sults:Administration of pectic polysaccharides significantly reduced the severity of DSS-induced colitis as assessed by DAT and histological score,and resulted in down regulation of MPO activity and NF-κB p65 expression and subsequent degradation of IκB protein,strikingly reduced the production of TNF-α and IL-17.Conclusions:Pectic polysaccharides extracted from Rauvolfia verticillata(Lour.)Baill.var.hainanensis Tsiang exerts beneficial effects in experimental colitis and may therefore provide a useful therapeutic approach for the treatment of UC.
文摘Twenty-seven antarctic bacteria producing extracellular polysaccharide (EPS) were selected from 57 strains by staining technology. The effects of major environmental factors on the growth and EPS production of Pseudoalteromonas sp. S - 15 - 13 were investigated, and the EPS was separated and purified for characterization analysis. The results showed that the optimal conditions for the EPS production were culture period, 56 h; growth temperature, 8 ℃ ; carbon source, 1.0% glucose; NaCI concentration, 3.0% ; pH 6.0 - 7.0. The EPS was purified by cold ethanol precipitation, proteins removal, ion exchange chromatography and gel chromatography technology. The molecular mass of EPS - H was 62 kDa as determined by the high performance gel permeation chromatography. Its sugar composition was a homopolymer of marmose analyzed by gas chromatograph spectroscopy. After repeated freezing and thawing of the bacteria hiomass in the presence of EPS, the bacterial growth was much higher than that observed after freezing in the absence of EPS and the difference augmented with the increase of freeze-thaw cycles. It is hypothesized that the adaptation of Pseudoalteromonas sp. S- 15 - 13 to the antarctic marine conditions, characterized by low temperature, high NaCl concentration and repeated freeze-thaw cycles, might be related to the EPS production ability.
基金Supported by Key-Area Research and Development Program of Guangdong Province(No.2020B1111030004)the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(No.GML2019ZD0406)+3 种基金the 13th Five-Year Plan Marine Economy Innovation Development Demonstration Project(No.BHSFS004)the Project of State Key Laboratory of Marine Resource Utilization in South China Sea(No.2018004)the Guizhou Education Department Young scientific talents Promoting Program(No.KY[2016]160)the Project of Danzi(WetCode)Group(No.DZ201501)。
文摘The use of high alkaline medium is a feasible way to provide carbon source and prevent biological contamination for the outdoor cultivation of alkaliphilic microalgae and cyanobacteria.A novel cyanobacterial strain was isolated from the open pond of a marine green alga(Picochlorum sp.SCSIO-45015,Sanya,Hainan)and identified as Cyanobacterium sp.SCSIO-45682.The effects of initial sodium bicarbonate(NaHCO_(3))concentrations on the growth and biochemical composition of Cyanobacterium sp.SCSIO-45682 were investigated.The results demonstrated that Cyanobacterium sp.SCSIO-45682 had good adaptation to 16.8-g/L NaHCO_(3)(the same concentration of NaHCO_(3) used in Zarrouk medium for Spirulina).Moreover,the yields of biomass,polysaccharide,chlorophyll a(chl a),and phycocyanin increased under high NaHCO_(3) concentrations.The maximum final biomass concentration of 2.5 g/L was observed at 8.4-g/L NaHCO_(3),while the highest intracellular total saccharide content of 49.2%of dry weight(DW)and exopolysaccharide(EPS)concentration of 93 mg/L were achieved at the NaHCO_(3) concentration of 16.8 g/L.The crude protein content declined under high NaHCO_(3) concentrations,which provide a possible explanation for the accumulation of polysaccharide.This study shows a good potential of alkaliphilic Cyanobacterium sp.SCSIO-45682 as a polysaccharide feedstock.