Glycoalkaloids in tissue cultures of Solanum acculeatissimum

The Science of Nature -     

腐殖酸对矿物结合汞植物活性的影响

以植物水培试验就腐殖酸（富里酸、棕色胡敏酸和灰色胡敏酸）对矿物结合汞（CaCO₃－Hg,Fe₂O₃-Hg,MnO₂-Hg,膨润土-Hg,高岭土-Hg）的植物活性的影响进行了探讨,并以土壤作印证试验.结果表明,溶解态无机汞是最有效的植物可吸收形态．腐殖酸对土壤、矿物结合汞的植物活性的影响,与其对矿物汞的络合溶解能力以及所形成的络合汞向无机汞转化的能力有关;矿物结合汞在不同环境条件下存在的稳定性及释放汞的潜力则是制约腐殖酸效应的内在因素.反应时间决定着二者作用进展的程度.     

Determination of the cellulase activity distribution in Clostridium thermocellum and Caldicellulosiruptor obsidiansis cultures using a fluorescent substrate

This study took advantage of resorufin cellobioside as a fluorescent substrate to determine the distribution of cellulase activity in cellulosic biomass fermentation systems. Cellulolytic biofilms were found to express nearly four orders greater cellulase activity compared to planktonic cultures of Clostridium thermocellum and Caldicellulosiruptor obsidiansis, which can be primarily attributed to the high cell concentration and surface attachment. The formation of biofilms results in cellulases being secreted close to their substrates, which appears to be an energetically favorable stategy for insoluble substrate utilization. For the same reason, cellulases should be closely associated with the surfaces of suspended cell in soluble substrate-fed culture, which has been verified with cellobiose-fed cultures of C. thermocellum and C. obsidiansis. This study addressed the importance of cellulase activity distribution in cellulosic biomass fermentation, and provided theoretical foundation for the leading role of biofilm in cellulose degradation. System optimization and reactor designs that promote biofilm formation in cellulosic biomass hydrolysis may promise an improved cellulosic biofuel process.     

New eco-friendly proposal for the crystallization of beet raw juice

In the past years we evaluated different strategies with the aim of eliminating completely from the beet sugar factory, the traditional calco-carbonic purification process taking into account the well-known problems related to the utilization of lime and the production of carbonation sludge.To complete the picture of the possible solutions to be adopted for the elimination of the traditional purification process, we tested and evaluated in laboratory and in pilot plants a new eco-friendly proposal.The results obtained, as well as the proposed flow-sheet and some economic evaluations, are presented and discussed.