We adopted the response surface methodology using single factor and orthogonal experiments to optimize four types of antimicrobial agents that could inhibit biofilm formation by Streptococcus mutans, which is commonly...We adopted the response surface methodology using single factor and orthogonal experiments to optimize four types of antimicrobial agents that could inhibit biofilm formation by Streptococcus mutans, which is commonly found in the human oral cavity and causes tooth decay. The objective was to improve the function of marine Arthrobacter oxydans KQll dextranase mouthwash （designed and developed by our laboratory）. The experiment was conducted in a three-level, four-variable central composite design to determine the best combination of ZnSO4, lysozyme, citric acid and chitosan. The optimized antibacterial agents were 2.16 g/L ZnSO4, 14 g/L lysozyme, 4.5 g/L citric acid and 5 g/L chitosan. The biofilm formation inhibition reached 84.49%. In addition, microscopic observation of the biofilm was performed using scanning electron microscopy and confocal laser scanning microscopy. The optimized formula was tested in marine dextranase Arthrobacter oxydans KQ11 mouthwash and enhanced the inhibition of S. mutans. This work may be promoted for the design and development of future marine dextranase oral care products.展开更多
The hydrolysis product of dextranase contains highly polymerized oligomeric isomaltose,which can be used as prebiotics to promote the colonization of probiotics,thus adjusting the ecological environment of intestinal ...The hydrolysis product of dextranase contains highly polymerized oligomeric isomaltose,which can be used as prebiotics to promote the colonization of probiotics,thus adjusting the ecological environment of intestinal flora.In this study,the expression of dextranase(PsDex1711)in Bacillus subtilis WB600 was enhanced by screening signal peptides.Furthermore,the potential application of dextranase for functional starch preparation was explored.Initially,a signal peptide library was constructed to identify the most efficient signal peptide for PsDex1711 secretion.Then,enzymatic hydrolysis was employed to produce porous buckwheat starch with varying pore sizes,and the impact of this enzymatic treatment on the physicochemical and microstructural properties of buckwheat starch was investigated.Signal peptide of the YwoF protein of unknown function demonstrated the highest extracellular PsDex1711 activity at 2.10±0.036 U/mL.Moreover,scanning electron microscope analysis revealed the development of deeper pores on the surface of starch granules after 18 h of enzymatic treatment,indicating the microstructural alterations induced by the enzymatic process and providing a foundation for further research in this field.The enzymatic hydrolysis also resulted in 40%and 35%increase in the water and oil absorption,respectively,compared to natural starch.Based on x-ray diffraction and Fourier transform infrared spectroscopy,it was inferred that the porous starch had a high degree of short-range ordering,which could provide a theoretical basis for the development and application of porous starch materials.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.3147171931271929)+2 种基金the Jiangsu Province and Technology Support Program(No.BE2013662)the Lianyungang Fifth“521 High-Level Talent Training Project”the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘We adopted the response surface methodology using single factor and orthogonal experiments to optimize four types of antimicrobial agents that could inhibit biofilm formation by Streptococcus mutans, which is commonly found in the human oral cavity and causes tooth decay. The objective was to improve the function of marine Arthrobacter oxydans KQll dextranase mouthwash （designed and developed by our laboratory）. The experiment was conducted in a three-level, four-variable central composite design to determine the best combination of ZnSO4, lysozyme, citric acid and chitosan. The optimized antibacterial agents were 2.16 g/L ZnSO4, 14 g/L lysozyme, 4.5 g/L citric acid and 5 g/L chitosan. The biofilm formation inhibition reached 84.49%. In addition, microscopic observation of the biofilm was performed using scanning electron microscopy and confocal laser scanning microscopy. The optimized formula was tested in marine dextranase Arthrobacter oxydans KQ11 mouthwash and enhanced the inhibition of S. mutans. This work may be promoted for the design and development of future marine dextranase oral care products.
基金supported by the National Natural Science Foundation of China(32172154)the National Key R&D Program of China(2022YFC2805101)The Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).Post-graduate Research&Practice Innovation Program of Jiangsu(IOU22-94).
文摘The hydrolysis product of dextranase contains highly polymerized oligomeric isomaltose,which can be used as prebiotics to promote the colonization of probiotics,thus adjusting the ecological environment of intestinal flora.In this study,the expression of dextranase(PsDex1711)in Bacillus subtilis WB600 was enhanced by screening signal peptides.Furthermore,the potential application of dextranase for functional starch preparation was explored.Initially,a signal peptide library was constructed to identify the most efficient signal peptide for PsDex1711 secretion.Then,enzymatic hydrolysis was employed to produce porous buckwheat starch with varying pore sizes,and the impact of this enzymatic treatment on the physicochemical and microstructural properties of buckwheat starch was investigated.Signal peptide of the YwoF protein of unknown function demonstrated the highest extracellular PsDex1711 activity at 2.10±0.036 U/mL.Moreover,scanning electron microscope analysis revealed the development of deeper pores on the surface of starch granules after 18 h of enzymatic treatment,indicating the microstructural alterations induced by the enzymatic process and providing a foundation for further research in this field.The enzymatic hydrolysis also resulted in 40%and 35%increase in the water and oil absorption,respectively,compared to natural starch.Based on x-ray diffraction and Fourier transform infrared spectroscopy,it was inferred that the porous starch had a high degree of short-range ordering,which could provide a theoretical basis for the development and application of porous starch materials.
