Succinic acid has recently emerged as an important chemical （commodity） because it can be used for the manufacturing of synthetic resins and biodegradable polymers and as an intermediate for chemical synthesis. Till...Succinic acid has recently emerged as an important chemical （commodity） because it can be used for the manufacturing of synthetic resins and biodegradable polymers and as an intermediate for chemical synthesis. Till date, succinic acid is mainly produced by chemical processes, however, due to the environmental concerns and the concepts of sustainability, researches are directed towards the production of succinic acid by microbial fermentation. The fact that carbon dioxide （CO2） is needed by the microorganisms for succinic acid production is another interesting feature. The fermentation was carried out with Actinobacillus succinogenes using a two-level fractional factorial design 2sl. The variables analyzed and their levels were： concentration of glucose, yeast extract, temperature, pH and agitation. The results show that the variables that more influenced on succinic acid production were pH, temperature and yeast extract.展开更多
The effects of direct extracts of compost (DEC), aerated fermentation extracts of compost (AFEC) and non-aerated fermentation extracts of compost (NAFEC) on cucumber growth and the action mechanisms were evaluated bas...The effects of direct extracts of compost (DEC), aerated fermentation extracts of compost (AFEC) and non-aerated fermentation extracts of compost (NAFEC) on cucumber growth and the action mechanisms were evaluated based on the structure and activity analysis of humic-like substances. AFEC increased cucumber growth most significantly, followed by DEC and NAFEC, which was insignificant compared to the control treatment. Humic-like substances from compost extracts played an important role in promoting cucumber growth. Application of humic-like substances stimulated auxin-like activity and increased chlorophyll content and nitrogen accumulation in plants. The positive auxin-like activity of humic-like substances could be attributed to the relative distribution of special carbon groups, such as those with a large amount of peptidic and carbohydratic groups or with a low content of phenolic groups. In conclusion, the best growth promotion by application of AFEC was mainly attributed to the humic-like substances in the AFEC.展开更多
文摘Succinic acid has recently emerged as an important chemical （commodity） because it can be used for the manufacturing of synthetic resins and biodegradable polymers and as an intermediate for chemical synthesis. Till date, succinic acid is mainly produced by chemical processes, however, due to the environmental concerns and the concepts of sustainability, researches are directed towards the production of succinic acid by microbial fermentation. The fact that carbon dioxide （CO2） is needed by the microorganisms for succinic acid production is another interesting feature. The fermentation was carried out with Actinobacillus succinogenes using a two-level fractional factorial design 2sl. The variables analyzed and their levels were： concentration of glucose, yeast extract, temperature, pH and agitation. The results show that the variables that more influenced on succinic acid production were pH, temperature and yeast extract.
基金Supported by the Ministry of Agriculture Public Benefit Research Foundation of China (No. 201103004)the National Key Technology R&D Program of China (No. 2010AA10Z401)
文摘The effects of direct extracts of compost (DEC), aerated fermentation extracts of compost (AFEC) and non-aerated fermentation extracts of compost (NAFEC) on cucumber growth and the action mechanisms were evaluated based on the structure and activity analysis of humic-like substances. AFEC increased cucumber growth most significantly, followed by DEC and NAFEC, which was insignificant compared to the control treatment. Humic-like substances from compost extracts played an important role in promoting cucumber growth. Application of humic-like substances stimulated auxin-like activity and increased chlorophyll content and nitrogen accumulation in plants. The positive auxin-like activity of humic-like substances could be attributed to the relative distribution of special carbon groups, such as those with a large amount of peptidic and carbohydratic groups or with a low content of phenolic groups. In conclusion, the best growth promotion by application of AFEC was mainly attributed to the humic-like substances in the AFEC.
