20 research outputs found
Fractionation of cellulase and beta-glucosidase in a Trichoderma reesei culture liquid by use of two-phase partitioning
An aqueous two-phase system based on the two polymers poly(ethylene glycol) and dextran has been used for the fractionation of cellulase enzymes present in culture liquid obtained by fermentation with Trichoderma reesei. The activities of beta-glucosidase and glucanases were separated to high degree by using the two-phase systems for a counter-current distribution process in nine transfer steps. While the glucanases had high affinity to the poly(ethylene glycol) rich top phase the beta-glucosidase was enriched in the dextran-containing bottom phase. Multiple counter-current distribution performed indicates the heterogeneity of beta-glucosidase activities assuming at least four isoenzyme forms. One step concentration of beta-glucosidase by using system with 46:1 phase volume ratio resulted in 16 times higher enzyme activity
Furustammars yttre och inre geometri inmÀtta inom projektet "Kvalitetssimulering av sÄgtimmer"
Denna rapport Àr en katalog över egenskaperna hos de 51 furustammar som mÀtts in i projekt "Kvalitetssimulering av sÄgtimmer". Stammarna kommer frÄn 4 bestÄnd (Mora, Skara, Bredbyn och JÀrlÄsa), valda med hÀnsyn till geografisk spridning och vikt som rÄvaruomrÄde för sÄgverken. De 4 bestÄnden jÀmförs sinesemellan vad gÀller olika kvist- och andra egenskaper. NÄgon djupare analys av inbördes samband mellan olika egenskaper har dock inte gjorts. Rapporten kan betraktas som en referensbank för andra forskare/utredare
Ucon-benzoyl dextran aqueous two-phase systems: protein purification with phase component recycling
Benzoyl dextran with a degree of substitution of 0.18 was synthesized by reacting dextran T500 with benzoyl chloride. A new type of aqueous two-phase system composed of benzoyl dextran as bottom phase polymer and the random copolymer of ethylene oxide and propylene oxide (Ucon 50-HB-5100) as top phase polymer has been formed. The phase diagram for the system Ucon 50-HB-5100-benzoyl dextran with a degree of substitution of 0.18 was determined at room temperature. This two-phase system has been used to purify 3-phosphoglycerate kinase from baker's yeast. The top-phase polymer (Ucon) can be separated from target enzyme by increasing the temperature. The bottom-phase polymer (benzoyl dextran) could be recovered by addition of salt. Yeast homogenate was partitioned in a primary Ucon 50-HB-5100-benzoyl dextran aqueous two-phase system. After phase separation the top phase was removed and temperature-induced phase separation was used for formation of a water phase and a Ucon-rich phase. The benzoyl dextran-enriched bottom phase from the primary system was diluted, and the polymer was separated from water by addition of Na2SO4