For the first time,the investigation delved into using a sustainable immobilization method using polyvinyl alcohol-alginate for pectinase,along with its application in clarifying Carica papaya juice.The pectinase pro-...For the first time,the investigation delved into using a sustainable immobilization method using polyvinyl alcohol-alginate for pectinase,along with its application in clarifying Carica papaya juice.The pectinase pro-duced by a newly isolated strain Aspergillus cervinus ARS2 was purified and immobilized into polyvinyl alcohol-alginate beads.Subsequently,the immobilized pectinase was subjected to characterization which revealed an optimum incubation time of 60 min,incubation pH of 5,and stability at acidic pH of 5 for 5 h storage time,and incubation temperature of 40℃,with stability at 40℃over a 5 h storage period.Reusability studies of immobilized pectinase showed a decrease in activity from 65.54 IU/mL(1^(st)cycle)to 13.49 IU/mL(6thcycle)with minimum reduction in activity up to 3 cycles indicating its cost-effectiveness across a range of industrial ap-plications.The kinetic parameters,Michaelis constant(K_(m)),and maximum reaction rate(V_(max))for free and immobilized pectinase were found to be 0.78 mg/mL,111.12 IU/mL,and 2.42 mg/mL,71.42 IU/mL respec-tively.The comparison of immobilized pectinase with free pectinase showed better stability and less activity.Further based on better performance,immobilized pectinase was utilized for optimization of Carica papaya juice clarification using response surface methodology.The optimal conditions were found to be 39.49℃incubation temperature,62.12 min incubation time,and 3.89 mL enzyme load,resulting in juice clarity of 38.23%±1.12%.These findings suggest that the pectinase immobilized using polyvinyl alcohol-alginate can be a promising,economical,and sustainable industrial process in the clarification of fruit juice.展开更多
The use of Beauveria bassiana proparations for control of coffee stem borers, Xylotrechus quardripes Chevr. and Acalolepta cervinus (Hope), as tested in the laboratory and field conditions. The results ...The use of Beauveria bassiana proparations for control of coffee stem borers, Xylotrechus quardripes Chevr. and Acalolepta cervinus (Hope), as tested in the laboratory and field conditions. The results show that each instar of coffee stem borers could be infected and killed successfully when being inoculated or contacted with B. bassiana . The control efficacy under indoor cultivation conditions exceeded 90% within 15 days. Jamming drilled hole with fungal mud resulted in the accumulative mortality and corrected mortality of >90% within 20 days. In the field, three methods, jamming drilled holes with bamboo sticker, bamboo sticker with fungal mud, and fungal mud only, were employed, and each led to the control effect of > 90% within 20 days. However, spraying suspensions and dusting powder of B. bassiana was insignificant. The yield of fresh coffee fruits in biological control area was 125 7?kg/0 067?ha greater than that of control area when being harvested in February. Compared the cost of microbial control with that of chemical control, B. bassiana proved to be a profitable, effective, and safe biocontrol agent against coffee stem borer.展开更多
文摘For the first time,the investigation delved into using a sustainable immobilization method using polyvinyl alcohol-alginate for pectinase,along with its application in clarifying Carica papaya juice.The pectinase pro-duced by a newly isolated strain Aspergillus cervinus ARS2 was purified and immobilized into polyvinyl alcohol-alginate beads.Subsequently,the immobilized pectinase was subjected to characterization which revealed an optimum incubation time of 60 min,incubation pH of 5,and stability at acidic pH of 5 for 5 h storage time,and incubation temperature of 40℃,with stability at 40℃over a 5 h storage period.Reusability studies of immobilized pectinase showed a decrease in activity from 65.54 IU/mL(1^(st)cycle)to 13.49 IU/mL(6thcycle)with minimum reduction in activity up to 3 cycles indicating its cost-effectiveness across a range of industrial ap-plications.The kinetic parameters,Michaelis constant(K_(m)),and maximum reaction rate(V_(max))for free and immobilized pectinase were found to be 0.78 mg/mL,111.12 IU/mL,and 2.42 mg/mL,71.42 IU/mL respec-tively.The comparison of immobilized pectinase with free pectinase showed better stability and less activity.Further based on better performance,immobilized pectinase was utilized for optimization of Carica papaya juice clarification using response surface methodology.The optimal conditions were found to be 39.49℃incubation temperature,62.12 min incubation time,and 3.89 mL enzyme load,resulting in juice clarity of 38.23%±1.12%.These findings suggest that the pectinase immobilized using polyvinyl alcohol-alginate can be a promising,economical,and sustainable industrial process in the clarification of fruit juice.
文摘The use of Beauveria bassiana proparations for control of coffee stem borers, Xylotrechus quardripes Chevr. and Acalolepta cervinus (Hope), as tested in the laboratory and field conditions. The results show that each instar of coffee stem borers could be infected and killed successfully when being inoculated or contacted with B. bassiana . The control efficacy under indoor cultivation conditions exceeded 90% within 15 days. Jamming drilled hole with fungal mud resulted in the accumulative mortality and corrected mortality of >90% within 20 days. In the field, three methods, jamming drilled holes with bamboo sticker, bamboo sticker with fungal mud, and fungal mud only, were employed, and each led to the control effect of > 90% within 20 days. However, spraying suspensions and dusting powder of B. bassiana was insignificant. The yield of fresh coffee fruits in biological control area was 125 7?kg/0 067?ha greater than that of control area when being harvested in February. Compared the cost of microbial control with that of chemical control, B. bassiana proved to be a profitable, effective, and safe biocontrol agent against coffee stem borer.
