The cellulase cocktail produced by marine Aspergillus niger exhibits a property of salt-tolerance,which is of great potential in cellulose degradation in high salt environment.In order to explain the mechanism on the ...The cellulase cocktail produced by marine Aspergillus niger exhibits a property of salt-tolerance,which is of great potential in cellulose degradation in high salt environment.In order to explain the mechanism on the salttolerance of the cellulase cocktail produced by marine A.niger,six cellulase components(AnCel6,AnCel7A,AnCel7B,AnEGL,AnBGL1 and AnBGL2)were obtained by directed expression.Studies on their enzymatic properties revealed that oneβ-glucosidase(AnBGL2)and one endoglucanase(AnEGL)exhibited an outstanding salttolerant property,and one cellobiohydrolase(AnCel7B)exhibited a certain salt-tolerant property.Subsequent study revealed that the salt-tolerant An EGL and AnCel7B endowed the cellulase cocktail with stronger salttolerant property,while the salt-tolerant An BGL2 had no positive effect.Moreover,after overexpression of AnCel6,AnCel7A,AnCel7B and AnEGL,the activity of cellulase cocktail increased by 80%,70%,63%and 68%,respectively.However,the activity of cellulase cocktail was not improved after overexpression of AnBGL1 and AnBGL2.After mixed-strain fermentation with cellobiohydrolase recombinants(cel6 a,cel7a and cel7b recombinants)and endoglucanase recombinant(egl recombinant),the the activity of cellulase cocktail increased by 114%,102%and91%,respectively.展开更多
[Objective]The aim was to induce and screen the high producing pectinase Aspergillus niger Strain based on the original preservation strains.[Method]The original strain was induced by ultraviolet,and the highst enzyme...[Objective]The aim was to induce and screen the high producing pectinase Aspergillus niger Strain based on the original preservation strains.[Method]The original strain was induced by ultraviolet,and the highst enzyme activity and cultivated time were detected through the inspection of transparent circle and enzyme activity determination of flask fermentation.[Result] The enzyme activity of strain D1-4 achieved its highest after cultivated for 96 h in suitable conditions,which was 141.13 U/ml.[Conclusion] The induced strain D1-4 had the strong ability of producing pectinase.展开更多
[Objective] The research aimed to breed the high-yield production strain of cellulase.[Method] Aspergillus niger was used as the starting strain,and a high-yield production strain of cellulase was selected after UV mu...[Objective] The research aimed to breed the high-yield production strain of cellulase.[Method] Aspergillus niger was used as the starting strain,and a high-yield production strain of cellulase was selected after UV mutation treatment.[Result] Under the suitable condition,the strain 2（15） with the highest CMC production capacity was selected,which nearly increased 50% than that of the starting strain.[Conclusion] The research provided the foundation for its appliation in the feed production in the future.展开更多
A mesophilic strain of Aspergillus niger isolated from cassava effluent samples produced extracellular glucoamylase in submerged culture containing 2% (w/v) soluble or sweet potato starch. On soluble starch medium the...A mesophilic strain of Aspergillus niger isolated from cassava effluent samples produced extracellular glucoamylase in submerged culture containing 2% (w/v) soluble or sweet potato starch. On soluble starch medium the maximum glucoamylase activity in the culture filtrate was 9.40 U/mg compared to 8.24 U/mg on sweet potato starch culture filtrate. The mycelial dry weight for both media was 494 and 418 mg respectively. The maximum glucoamylase activity was obtained at a growth temperature of 40°C and pH 4.5. The implication is that the bioprocess of utilizing sweet potato starch in the culture is attractive due to its relatively cheaper availability in Nigeria, making it even more favorable when economics is considered.展开更多
The main purpose of this study is to identify the socio-economic implications of re-current flooding on women development in southern Ijaw Local Government Area. Generally, flooding may result in socio-economic, ecolo...The main purpose of this study is to identify the socio-economic implications of re-current flooding on women development in southern Ijaw Local Government Area. Generally, flooding may result in socio-economic, ecological and health problems. This study assumes that on flood days the movement of customers and sellers tends to be hindered, thus resulting in the retardation of transactions and the reduction of daily income earned. The study compared the situation of female traders with that of male traders. Both primary and secondary data were used in this study. Primary data were collected using an open-ended questionnaire. A total of 83 questionnaires were randomly distributed to members of four communities, which were selected through stratified random sampling procedures. Also 33 randomly selected women and men respectively, engaged in marketing activities from open and locked-up shops, were sampled to observe the level of their personal income (in Naira), from customers patronage during 3 flood days and 3 non-flood days. Other data and information were obtained through Key Informants Interview (KII), and observations. Hypotheses I and II were tested using Analysis of Variance (ANOVA) statistical model. Null hypothesis I (H<sub>0</sub>), which states that “There is no statistically significant difference in the income earned by men and women traders from marketing activities on flood days and non-flood days in Southern Ijaw Local Government Area, Bayelsa State”, is accepted (F-value: 3.8723939, P-value: 2.494E-05), whereas null hypothesis II (H<sub>0</sub>), which states that “There is no statistically significant difference in the income earned by women traders from marketing activities on flood and non-flood days in Southern Ijaw Local Government Area, Bayelsa State, is rejected (F-value: 2.524902, P-value: 0.030069). Thus while there is no significant difference in the earnings of male and female traders on flood and non-flood days, there are significant differences in sales earning among women traders on those days. Factors affecting trading income on flood and non-flood days include accessibility to business premises by customers, ability of male marketers to afford non-easily flooded business premises;and women traders with limited resources often have less suitably drained premises. Reduced total household income can detrimentally affect food affordability, availability, household nutrition, family health and wellbeing. Recommendations highlighting the roles of communities, government and stakeholders in flood management are proffered.展开更多
基金supported by National Natural Science Foundation of China(21576233,21878263)Fundamental Research Funds for the Central Universities。
文摘The cellulase cocktail produced by marine Aspergillus niger exhibits a property of salt-tolerance,which is of great potential in cellulose degradation in high salt environment.In order to explain the mechanism on the salttolerance of the cellulase cocktail produced by marine A.niger,six cellulase components(AnCel6,AnCel7A,AnCel7B,AnEGL,AnBGL1 and AnBGL2)were obtained by directed expression.Studies on their enzymatic properties revealed that oneβ-glucosidase(AnBGL2)and one endoglucanase(AnEGL)exhibited an outstanding salttolerant property,and one cellobiohydrolase(AnCel7B)exhibited a certain salt-tolerant property.Subsequent study revealed that the salt-tolerant An EGL and AnCel7B endowed the cellulase cocktail with stronger salttolerant property,while the salt-tolerant An BGL2 had no positive effect.Moreover,after overexpression of AnCel6,AnCel7A,AnCel7B and AnEGL,the activity of cellulase cocktail increased by 80%,70%,63%and 68%,respectively.However,the activity of cellulase cocktail was not improved after overexpression of AnBGL1 and AnBGL2.After mixed-strain fermentation with cellobiohydrolase recombinants(cel6 a,cel7a and cel7b recombinants)and endoglucanase recombinant(egl recombinant),the the activity of cellulase cocktail increased by 114%,102%and91%,respectively.
文摘[Objective]The aim was to induce and screen the high producing pectinase Aspergillus niger Strain based on the original preservation strains.[Method]The original strain was induced by ultraviolet,and the highst enzyme activity and cultivated time were detected through the inspection of transparent circle and enzyme activity determination of flask fermentation.[Result] The enzyme activity of strain D1-4 achieved its highest after cultivated for 96 h in suitable conditions,which was 141.13 U/ml.[Conclusion] The induced strain D1-4 had the strong ability of producing pectinase.
基金Supported by Natural Foundation of Education Department of HenanProvince (2010B530001)Research Project of Department of Sci-ence and Technology in Henan Province (102102310391)~~
文摘[Objective] The research aimed to breed the high-yield production strain of cellulase.[Method] Aspergillus niger was used as the starting strain,and a high-yield production strain of cellulase was selected after UV mutation treatment.[Result] Under the suitable condition,the strain 2（15） with the highest CMC production capacity was selected,which nearly increased 50% than that of the starting strain.[Conclusion] The research provided the foundation for its appliation in the feed production in the future.
文摘A mesophilic strain of Aspergillus niger isolated from cassava effluent samples produced extracellular glucoamylase in submerged culture containing 2% (w/v) soluble or sweet potato starch. On soluble starch medium the maximum glucoamylase activity in the culture filtrate was 9.40 U/mg compared to 8.24 U/mg on sweet potato starch culture filtrate. The mycelial dry weight for both media was 494 and 418 mg respectively. The maximum glucoamylase activity was obtained at a growth temperature of 40°C and pH 4.5. The implication is that the bioprocess of utilizing sweet potato starch in the culture is attractive due to its relatively cheaper availability in Nigeria, making it even more favorable when economics is considered.
文摘The main purpose of this study is to identify the socio-economic implications of re-current flooding on women development in southern Ijaw Local Government Area. Generally, flooding may result in socio-economic, ecological and health problems. This study assumes that on flood days the movement of customers and sellers tends to be hindered, thus resulting in the retardation of transactions and the reduction of daily income earned. The study compared the situation of female traders with that of male traders. Both primary and secondary data were used in this study. Primary data were collected using an open-ended questionnaire. A total of 83 questionnaires were randomly distributed to members of four communities, which were selected through stratified random sampling procedures. Also 33 randomly selected women and men respectively, engaged in marketing activities from open and locked-up shops, were sampled to observe the level of their personal income (in Naira), from customers patronage during 3 flood days and 3 non-flood days. Other data and information were obtained through Key Informants Interview (KII), and observations. Hypotheses I and II were tested using Analysis of Variance (ANOVA) statistical model. Null hypothesis I (H<sub>0</sub>), which states that “There is no statistically significant difference in the income earned by men and women traders from marketing activities on flood days and non-flood days in Southern Ijaw Local Government Area, Bayelsa State”, is accepted (F-value: 3.8723939, P-value: 2.494E-05), whereas null hypothesis II (H<sub>0</sub>), which states that “There is no statistically significant difference in the income earned by women traders from marketing activities on flood and non-flood days in Southern Ijaw Local Government Area, Bayelsa State, is rejected (F-value: 2.524902, P-value: 0.030069). Thus while there is no significant difference in the earnings of male and female traders on flood and non-flood days, there are significant differences in sales earning among women traders on those days. Factors affecting trading income on flood and non-flood days include accessibility to business premises by customers, ability of male marketers to afford non-easily flooded business premises;and women traders with limited resources often have less suitably drained premises. Reduced total household income can detrimentally affect food affordability, availability, household nutrition, family health and wellbeing. Recommendations highlighting the roles of communities, government and stakeholders in flood management are proffered.
