Effect of drought stress on growth of Glycyrrhiza uralensis / 中国中药杂志

<p><b>OBJECTIVE</b>To study the effect of drought stress on the growth of Glycyrrhiza uralensis and its drought resistance characteristic.</p><p><b>METHOD</b>The growth in dicators of G. uralensis including leaf, stem, root and biomass were measured when two-years-old G. uralensis had lived in drought stress soil for 60 days.</p><p><b>RESULT</b>The growth of all organs of G. uralensis was restrained because of drought stress, especially to up ground organs.</p><p><b>CONCLUSION</b>It is obvious that the restraining effect of drought stress on G. uralensis possesses organ speciality. Both yield and quality of G. uralensis will be satisfied when it grows in the soil with relative water content of 50%.</p>

Continuous biosynthesis of epoxypropane in a methanotrophic attached-films reactor / 生物工程学报

Using a fluidized bed as immobilization system, mixed culture methanotrophic attached-films were developed on diatomite particles. The Methane Monooxygenase (MMO) activity was found to increase obviously as soon as the lag phase ended. Greater than 90% of the MMO activity in the bed was attached. Biofilm concentration of 3.3-3.7 mg dry weight cell/g DS was observed. Batch experiments were performed to explore the possibility of producing epoxypropane by a cooxidation process. The effect of methane on the oxidation of propene to epoxypropane and the effect of propene on the growth of methanotroph were also studied. In continuous experiments, optimum mixed gaseous substrates (methane: 35%; propene: 20%; oxygen: 45%) were continuously circulated through the fluidized bed reactor to remove product. Initial epoxypropane productivity was 110-150 mumol/d. The bioreactor operated continuously for 25 d without obvious loss of epoxypropane productivity.