In this work,rhamnolipid production was investigated using waste frying oil as the sole carbon source. By culture in shaking flasks,a naturally isolated strain synthesized rhamnolipid at concentration of 12.47 g/L and...In this work,rhamnolipid production was investigated using waste frying oil as the sole carbon source. By culture in shaking flasks,a naturally isolated strain synthesized rhamnolipid at concentration of 12.47 g/L and its mutant after treatment by UV light increased this productivity to 24.61 g/L. Fermentation was also conducted in a 50 L bioreactor and the productivity reached over 20 g/L. Hence,with a stable and high productive mutant strain,it could be feasible to reuse waste frying oil for rhamnolipid production on industrial scale.展开更多
Heterotrophic culture of microalgae to develop methods of increasing biomass productivity and storage lipids has brought new insight to commercial biodiesel production. To understand the relationship between heterotro...Heterotrophic culture of microalgae to develop methods of increasing biomass productivity and storage lipids has brought new insight to commercial biodiesel production. To understand the relationship between heterotrophy and lipid production, the effects of carbon sources on the growth and lipid accumulation of Chlorella sorokiniana GXNN01 was studied. The alga exhibited an increased growth rate in response to the addition of carbon sources, which reached the stationary phase after 48 h at 30℃. In addition, glucose and NaAc had a significant effect on the lipid accumulation during the early-stationary phase. Specifically, the lipid content was 0.237±0.026 g ·g^-1 cell dry weight and 0.272±0.041 g Ll when glucose was used as the carbon source, whereas the lipid content reached 0.287±0.018 g ·g^-1 cell dry weight and 0.2884-0.008 g Lz when NaAc was used as the carbon source. The neutral lipid content was found to first decrease and then increase over time during the growth phase. A glucose concentration of 20 mmol L^-1 gave the maximal lipid yield and the optimum harvest time was the early-stationary phase.展开更多
Sulfate chitosan derivatives have good solubility and therapeutic effect on the cell model of NAFLD. The aim of this study was to examine the therapeutic effect of sulfate chitosan derivatives on NAFLD. The male Wista...Sulfate chitosan derivatives have good solubility and therapeutic effect on the cell model of NAFLD. The aim of this study was to examine the therapeutic effect of sulfate chitosan derivatives on NAFLD. The male Wistar rats were orally fed high fat emulsion and received sulfate chitosan derivatives for 5 weeks to determine the pre-treatment effect of sulfate chitosan derivatives on NAFLD. To evaluate the therapeutic effect of sulfate chitosan derivatives on NAFLD, the rats were orally fed with high concentration emulsion for 5 weeks, followed by sulfate chitosan derivatives for 3 weeks. Histological analysis and biomedical assays showed that sulfate chitosan derivatives can dramatically prevent the development of hepatic steatosis in hepatocyte cells. In animal studies, pre-treatment and treatment with sulfate chitosan derivatives significantly protected against hepatic steatohepatitis induced by high fat diet according to histological analysis. Furthermore, increased TC, ALT, MDA, and LEP in NAFLD were significantly ameliorated by pre-treatment and treatment with sulfate chitosan derivatives. Furthermore, increased TG, AST, and TNF-α in NAFLD were significantly ameliorated by treatment with sulfate chitosan derivatives. Sulfate chitosan derivatives have good pre-treatment and therapeutic effect on NAFLD.展开更多
Objective ： To investigate the mechanism of polymyxin B （ PMB ） antagonizing the biological activity of Hipopolysaccharide （LPS）. Methods： The affinity of PMB for LPS and lipid A was assayed by biosensor, and t...Objective ： To investigate the mechanism of polymyxin B （ PMB ） antagonizing the biological activity of Hipopolysaccharide （LPS）. Methods： The affinity of PMB for LPS and lipid A was assayed by biosensor, and the neutralization of PMB for LPS （2 ng/ml ） was detected by kinetic turbidimetric limnins test. The releases of TNF-α and IL-6 in murine peritoneal macrophages （PMφ） after exposure to LPS （ 100 ng/ml） were detected, and the expression levels of TLR4, TNF-α and IL-6 mRNA in PMφ induced by LPS （100 ng/ml） were measured by RT-PCR. Results： PMB had high-affinity to LPS and lipid A with dissociation equilibrium constants of 18.9 nmol/L and 11.1 nmol/L, respectively, and neutralized LPS in a dosedependent manner. Furthermore, PMB could markedly inhibit the expressions of TLR4, TNF-α and IL-6 mRNA and the release of cycokines in LPS-stimniated murine PMφ. Conclusions： PMB neutralizes LPS and inhibites the expression and release of cycokines in macrophages, in which the affinity of PMB for lipid A plays an important role.展开更多
Oily wastewater generated by various industries creates a major ecological problem throughout the world. The tra- ditional methods for the oily wastewater treatment are inefficient and costly. Surfactants can promote ...Oily wastewater generated by various industries creates a major ecological problem throughout the world. The tra- ditional methods for the oily wastewater treatment are inefficient and costly. Surfactants can promote the biodegradation of pe- troleum hydrocarbons by dispersing oil into aqueous environment. In the present study, we applied rhamnolipid-containing cell-free culture broth to enhance the biodegradation of crude oil and lubricating oil in a conventional aerobically-activated sludge system. At 20 ℃, rhamnolipids （11.2 mg/L） increased the removal efficiency of crude oil from 17.7% （in the absence of rham- nolipids） to 63%. At 25 ~C, the removal efficiency of crude oil was over 80% with the presence of rhamnolipids compared with 22.3% in the absence of rhamnolipids. Similarly, rhamnolipid treatment （22.5 mg/L） for 24 h at 20℃ significantly increased the removal rate of lubricating oil to 92% compared with 24% in the absence of rhamnolipids. The enhanced removal of hydrocarbons was mainly attributed to the improved solubility and the reduced interfacial tension by rhamnolipids. We conclude that a direct application of the crude rhamnolipid solution from cell culture is effective and economic in removing oily contaminants from wastewater.展开更多
The supplementation with 50, 100 and 150μg/mL potassium chloride to the fifth instar larvae of the silkworm Bombyx mori on fat body glycogen, protein, total lipids and haemolymph protein and trehalose were analyzed. ...The supplementation with 50, 100 and 150μg/mL potassium chloride to the fifth instar larvae of the silkworm Bombyx mori on fat body glycogen, protein, total lipids and haemolymph protein and trehalose were analyzed. The fat body glycogen and protein and haemolymph protein were increased significantly in all the treated groups; whereas fat body total lipids increased only in 100 and 150μg/mL and haemolymph trehalose increased only in 150μg/mL potassium chloride-treated groups when compared with those of the corresponding parameters of the carrier controls.展开更多
Production of reactive oxygen species(ROS)is a conserved immune response primarily mediated by NADPH oxidases(NOXs),also known in plants as respiratory burst oxidase homologs(RBOHs).Most microbe-associated molecular p...Production of reactive oxygen species(ROS)is a conserved immune response primarily mediated by NADPH oxidases(NOXs),also known in plants as respiratory burst oxidase homologs(RBOHs).Most microbe-associated molecular patterns(MAMPs)trigger a very fast and transient ROS burst in plants.However,recently,we found that lipopolysaccharides(LPS),a typical bacterial MAMP,triggered a biphasic ROS burst.In this study,we isolated mutants defective in LPS-triggered biphasic ROS burst(delt)in Arabidopsis,and cloned the DELT1 gene that was shown to encode RBOHD.In the delt1-2 allele,the antepenultimate residue,glutamic acid(E919),at the C-terminus of RBOHD was mutated to lysine(K).E919 is a highly conserved residue in NADPH oxidases,and a mutation of the corresponding residue E568 in human NOX2 has been reported to be one of the causes of chronic granulomatous disease.Consistently,we found that residue E919 was indispensable for RBOHD function in the MAMP-induced ROS burst and stomatal closure.It has been suggested that the mutation of this residue in other NADPH oxidases impairs the protein’s stability and complex assembly.However,we found that the E919K mutation did not affect RBOHD protein abundance or the ability of protein association,suggesting that the residue E919 in RBOHD might have a regulatory mechanism different from that of other NOXs.Taken together,our results confirm that the antepenultimate residue E is critical for NADPH oxidases and provide a new insight into the regulatory mechanisms of RBOHD.展开更多
基金Project (No. 2006C100105) supported by the Ningbo Scientific Research Project, China
文摘In this work,rhamnolipid production was investigated using waste frying oil as the sole carbon source. By culture in shaking flasks,a naturally isolated strain synthesized rhamnolipid at concentration of 12.47 g/L and its mutant after treatment by UV light increased this productivity to 24.61 g/L. Fermentation was also conducted in a 50 L bioreactor and the productivity reached over 20 g/L. Hence,with a stable and high productive mutant strain,it could be feasible to reuse waste frying oil for rhamnolipid production on industrial scale.
基金Supported by the National High Technology Research and Development Program of China (863 Program) (No.2006AA05Z112)the Key Project of Science and Technology for Supporting Tianjin Development (No.2007LS700310)the Knowledge Innovation Project of Chinese Academy of Sciences (No.KGCX2-YW-374-3)
文摘Heterotrophic culture of microalgae to develop methods of increasing biomass productivity and storage lipids has brought new insight to commercial biodiesel production. To understand the relationship between heterotrophy and lipid production, the effects of carbon sources on the growth and lipid accumulation of Chlorella sorokiniana GXNN01 was studied. The alga exhibited an increased growth rate in response to the addition of carbon sources, which reached the stationary phase after 48 h at 30℃. In addition, glucose and NaAc had a significant effect on the lipid accumulation during the early-stationary phase. Specifically, the lipid content was 0.237±0.026 g ·g^-1 cell dry weight and 0.272±0.041 g Ll when glucose was used as the carbon source, whereas the lipid content reached 0.287±0.018 g ·g^-1 cell dry weight and 0.2884-0.008 g Lz when NaAc was used as the carbon source. The neutral lipid content was found to first decrease and then increase over time during the growth phase. A glucose concentration of 20 mmol L^-1 gave the maximal lipid yield and the optimum harvest time was the early-stationary phase.
基金supported by the National High Technology Research and Development Program of China (863 Program 2006AA090401)
文摘Sulfate chitosan derivatives have good solubility and therapeutic effect on the cell model of NAFLD. The aim of this study was to examine the therapeutic effect of sulfate chitosan derivatives on NAFLD. The male Wistar rats were orally fed high fat emulsion and received sulfate chitosan derivatives for 5 weeks to determine the pre-treatment effect of sulfate chitosan derivatives on NAFLD. To evaluate the therapeutic effect of sulfate chitosan derivatives on NAFLD, the rats were orally fed with high concentration emulsion for 5 weeks, followed by sulfate chitosan derivatives for 3 weeks. Histological analysis and biomedical assays showed that sulfate chitosan derivatives can dramatically prevent the development of hepatic steatosis in hepatocyte cells. In animal studies, pre-treatment and treatment with sulfate chitosan derivatives significantly protected against hepatic steatohepatitis induced by high fat diet according to histological analysis. Furthermore, increased TC, ALT, MDA, and LEP in NAFLD were significantly ameliorated by pre-treatment and treatment with sulfate chitosan derivatives. Furthermore, increased TG, AST, and TNF-α in NAFLD were significantly ameliorated by treatment with sulfate chitosan derivatives. Sulfate chitosan derivatives have good pre-treatment and therapeutic effect on NAFLD.
基金This work was supported by the grant from the National Key Technologies R&D Program(G1999054203)
文摘Objective ： To investigate the mechanism of polymyxin B （ PMB ） antagonizing the biological activity of Hipopolysaccharide （LPS）. Methods： The affinity of PMB for LPS and lipid A was assayed by biosensor, and the neutralization of PMB for LPS （2 ng/ml ） was detected by kinetic turbidimetric limnins test. The releases of TNF-α and IL-6 in murine peritoneal macrophages （PMφ） after exposure to LPS （ 100 ng/ml） were detected, and the expression levels of TLR4, TNF-α and IL-6 mRNA in PMφ induced by LPS （100 ng/ml） were measured by RT-PCR. Results： PMB had high-affinity to LPS and lipid A with dissociation equilibrium constants of 18.9 nmol/L and 11.1 nmol/L, respectively, and neutralized LPS in a dosedependent manner. Furthermore, PMB could markedly inhibit the expressions of TLR4, TNF-α and IL-6 mRNA and the release of cycokines in LPS-stimniated murine PMφ. Conclusions： PMB neutralizes LPS and inhibites the expression and release of cycokines in macrophages, in which the affinity of PMB for lipid A plays an important role.
基金Project (No. 56310503014) supported by the Department of Education of Zhejiang Province, China
文摘Oily wastewater generated by various industries creates a major ecological problem throughout the world. The tra- ditional methods for the oily wastewater treatment are inefficient and costly. Surfactants can promote the biodegradation of pe- troleum hydrocarbons by dispersing oil into aqueous environment. In the present study, we applied rhamnolipid-containing cell-free culture broth to enhance the biodegradation of crude oil and lubricating oil in a conventional aerobically-activated sludge system. At 20 ℃, rhamnolipids （11.2 mg/L） increased the removal efficiency of crude oil from 17.7% （in the absence of rham- nolipids） to 63%. At 25 ~C, the removal efficiency of crude oil was over 80% with the presence of rhamnolipids compared with 22.3% in the absence of rhamnolipids. Similarly, rhamnolipid treatment （22.5 mg/L） for 24 h at 20℃ significantly increased the removal rate of lubricating oil to 92% compared with 24% in the absence of rhamnolipids. The enhanced removal of hydrocarbons was mainly attributed to the improved solubility and the reduced interfacial tension by rhamnolipids. We conclude that a direct application of the crude rhamnolipid solution from cell culture is effective and economic in removing oily contaminants from wastewater.
文摘The supplementation with 50, 100 and 150μg/mL potassium chloride to the fifth instar larvae of the silkworm Bombyx mori on fat body glycogen, protein, total lipids and haemolymph protein and trehalose were analyzed. The fat body glycogen and protein and haemolymph protein were increased significantly in all the treated groups; whereas fat body total lipids increased only in 100 and 150μg/mL and haemolymph trehalose increased only in 150μg/mL potassium chloride-treated groups when compared with those of the corresponding parameters of the carrier controls.
基金the National Natural Science Foundation of China(No.31622006)the Postdoctoral Science Foundation of China(Nos.2018M630683 and 2018T110601)
文摘Production of reactive oxygen species(ROS)is a conserved immune response primarily mediated by NADPH oxidases(NOXs),also known in plants as respiratory burst oxidase homologs(RBOHs).Most microbe-associated molecular patterns(MAMPs)trigger a very fast and transient ROS burst in plants.However,recently,we found that lipopolysaccharides(LPS),a typical bacterial MAMP,triggered a biphasic ROS burst.In this study,we isolated mutants defective in LPS-triggered biphasic ROS burst(delt)in Arabidopsis,and cloned the DELT1 gene that was shown to encode RBOHD.In the delt1-2 allele,the antepenultimate residue,glutamic acid(E919),at the C-terminus of RBOHD was mutated to lysine(K).E919 is a highly conserved residue in NADPH oxidases,and a mutation of the corresponding residue E568 in human NOX2 has been reported to be one of the causes of chronic granulomatous disease.Consistently,we found that residue E919 was indispensable for RBOHD function in the MAMP-induced ROS burst and stomatal closure.It has been suggested that the mutation of this residue in other NADPH oxidases impairs the protein’s stability and complex assembly.However,we found that the E919K mutation did not affect RBOHD protein abundance or the ability of protein association,suggesting that the residue E919 in RBOHD might have a regulatory mechanism different from that of other NOXs.Taken together,our results confirm that the antepenultimate residue E is critical for NADPH oxidases and provide a new insight into the regulatory mechanisms of RBOHD.
