Extracellular polymeric substances（EPS） are organic metabolic compounds excreted by microorganisms. They largely impact microbial aggregate structures and functions.Extracellular polysaccharides（EP） in EPS are res...Extracellular polymeric substances（EPS） are organic metabolic compounds excreted by microorganisms. They largely impact microbial aggregate structures and functions.Extracellular polysaccharides（EP） in EPS are responsible for the formation of microbial aggregates. In this work, we successfully separated and characterized EP from EPS of the bacterium Bacillus megaterium TF10. Extraction of EP from EPS was optimized using Sevag＇s reagent. Chemical characteristics, functional groups, and molecular weight（MW） distribution of EP were compared with the harvested EPS and soluble microbial products（SMP）. We found that the polymers of lower MW and free proteins were successfully removed by Sevag＇s reagent. The higher MW components of EPS were predominantly polysaccharides,while the polymers of lower MW tended to secrete to the supernatant and were described as SMP. A part of the proteins in the EP was polysaccharide-bonded. Our results can be further used in elucidating the complex flocculation mechanisms in which EP play a major role.展开更多
Robot Application and Adjustment of Export Product Scope:Can We Have Both Efficiency and Quality?Jianhong Qi,Zhitong Zhang Based on the matching data of China Industrial Enterprise Database and China Customs Database ...Robot Application and Adjustment of Export Product Scope:Can We Have Both Efficiency and Quality?Jianhong Qi,Zhitong Zhang Based on the matching data of China Industrial Enterprise Database and China Customs Database from 2000 to 2015,this paper examines the infuence of robot application(RA)on the export product scope(EPS)of multi-product enterprises(MPEs),the influence channels,and the export competition strategies of these enterprises.The research results show that RA has promoted the expansion of EPS of MPEs,and this promotion effect is prominent especially for the export of laborintensive products,resource-intensive products and for non-state-owned enterprises(SOEs).The adjustment of EPS by RA not only enhances efficiency through productivity improvement effect and cost-saving effect,but also improves quality through emission-reduction effect and product quality effect,which is very obvious in long-quality-ladder enterprises.The RA-expanded product scope covers both old products and new products manufactured in the same industry.Facing fierce competition in the same industry,robot-using enterprises prefer quality competition strategy,which further promotes the expansion of EPS.展开更多
基金supported by the National Natural Science Foundation of China (No. 21607031)Science and Technology Planning Project of Guangdong Province, China (Nos. 2014A010107023, 2015B020230002, and 2016A010103020)
文摘Extracellular polymeric substances（EPS） are organic metabolic compounds excreted by microorganisms. They largely impact microbial aggregate structures and functions.Extracellular polysaccharides（EP） in EPS are responsible for the formation of microbial aggregates. In this work, we successfully separated and characterized EP from EPS of the bacterium Bacillus megaterium TF10. Extraction of EP from EPS was optimized using Sevag＇s reagent. Chemical characteristics, functional groups, and molecular weight（MW） distribution of EP were compared with the harvested EPS and soluble microbial products（SMP）. We found that the polymers of lower MW and free proteins were successfully removed by Sevag＇s reagent. The higher MW components of EPS were predominantly polysaccharides,while the polymers of lower MW tended to secrete to the supernatant and were described as SMP. A part of the proteins in the EP was polysaccharide-bonded. Our results can be further used in elucidating the complex flocculation mechanisms in which EP play a major role.
基金the major project(17ZDA040)of National Social Science Fundthe major project(72192842)of National Natural Science Foundation for their support.
文摘Robot Application and Adjustment of Export Product Scope:Can We Have Both Efficiency and Quality?Jianhong Qi,Zhitong Zhang Based on the matching data of China Industrial Enterprise Database and China Customs Database from 2000 to 2015,this paper examines the infuence of robot application(RA)on the export product scope(EPS)of multi-product enterprises(MPEs),the influence channels,and the export competition strategies of these enterprises.The research results show that RA has promoted the expansion of EPS of MPEs,and this promotion effect is prominent especially for the export of laborintensive products,resource-intensive products and for non-state-owned enterprises(SOEs).The adjustment of EPS by RA not only enhances efficiency through productivity improvement effect and cost-saving effect,but also improves quality through emission-reduction effect and product quality effect,which is very obvious in long-quality-ladder enterprises.The RA-expanded product scope covers both old products and new products manufactured in the same industry.Facing fierce competition in the same industry,robot-using enterprises prefer quality competition strategy,which further promotes the expansion of EPS.
