Metabolic response of different osmo-sensitive Sacchromyces cerevisiae to ACA microcapsule

Microencapsulation technology is a convenient method to alter and regulate cell product formation. In order to probe the metabolic response of different osmo-sensitive Sacchromyces cerevisiae to ACA microcapsule, the hyper-osmo-sensitive type S. cerevisiae (Y02724) and wild type S. cerevisiae (BY4741) were encapsulated into liquid core ACA microcapsules. The behavior of cell growth, glucose consumption, ethanol production and the yields of glycerol and organic acids were determined. Free cell culture was used as control. The enzyme activities of NADP⁺-glutamate dehydrogenase (GDH), glutamine synthetase (GS) and glutamate synthase (GOGAT) on microencapsulation cells and free cultured cells were measured too. The results demonstrated that the growth of Y02724 in both aerobic and anaerobic conditions was seriously inhibited by ACA microcapsule, while the ethanol and acetatic acid yield of microencapsulation Y02724 in anaerobic condition were significantly higher than that of suspended cultivation. For Y02724, the microencapsulation cultivation significantly increased the GS and GOGAT activities and decreased the GDH activity in comparison with control group. ACA microcapsules did not significantly change the growth behavior and metabolic performance of BY4741, but decreased the GS activity. In conclusion, microcapsules microenvironment significantly changes the metabolism behavior of hyper-osmo-sensitive type S. cerevisiae (Y02724), but nearly had no effect on BY4741.     

江苏金坛地区烟粉虱的发生扩散及寄主适合性分析

系统调查表明,金坛市尧塘花木基地是该地区烟粉虱扩散蔓延的虫源地。该虫4月下旬逐渐从越冬虫源地向外扩散蔓延,首先在葎草[Humulus scandens(Lour)M err]上产卵危害,然后再危害其它植物;距虫源地越近,发生的时间早,虫口密度高,反之,则发生的时间迟,虫口密度低;11月下旬部分种群迁移到温室大棚内越冬。本文还提出了相应的控制措施。