An outdoor biophotolytic system using the cyanobacterium Anabaena cylindrica B629

The cyanobacterium Anabaena cylindrica B629 was suspended in small glass beds and incubated in a gas-tight glass vessel outdoors under a gas atmosphere comprising carbon monoxide (0.2%), acetylene (5%), oxygen (6.5%), and nitrogen. The solution phase initially contained sodium bicarbonate (10mM) at pH 7. Under these conditions the organism continuously produced hydrogen gas for over three weeks. The temperature of the culture was maintained below 30°C and minimum night temperatures were recorded. The vessel was covered by a shadecloth, which reduced the natural illumination by approximately 70%. The system is an alternative to those requiring the strict absence of oxygen and little nitrogen, and requires virtually no attention during the incubation period.     

A new family of 2-hydroxyacid dehydrogenases

The NADH-dependent hydroxypyruvate reductase from cucumber and the pdxB gene product of E. coli display significant homology to E. coli D-3-phosphoglycerate dehydrogenase. In contrast, these proteins do not display much similarity with other oxidoreductases or with other 2-hydroxyacid dehydrogenases in particular. On the basis of their relatedness and the structure of their substrates, these three enzymes constitute a new family of 2-hydroxyacid dehydrogenases distinct from malate and lactate dehydrogenase.     

Varieties of Anomalous Experience: Examining the Scientific Evidence

Varieties of Anomalous Experience: Examining the Scientific Evidence. Etzel Cardeña. Steven Jay Lynn. and Stanley Krippner. eds. Washington, DC: American Psychological Association, 2000. 476 pp.     

The effect of water-miscible solvents on the Δ1-dehydrogenase activity of free and PAAH-entrapped Arthrobacter simplex

Summary The effect of water-miscible cosolvents on biotransformations of poorly water-soluble substrates by immobilized cells was investigated, using ¹-dehydrogenation of hydrocortisone by Arthrobacter simplex as a model. Criteria for solvent selection on the basis of retention of enzymic activity were postulated and tested. Diols were considered to be the most suitable group of solvents. Substrate solubility increased tenfold in 30% (v/v) ethylene glycol, but reaction rates were significantly slower in such solutions. This was mainly caused by a decrease of oxygen solubility in the presence of the cosolvent and conformational changes imposed on the intracellular enzyme by cosolvent molecules penetrating the cell. The inhibition could be eliminated by the addition of an artificial electron acceptor, phenazine methosulphate (PMS). Reaction rates faster than those for substrate suspensions (no cosolvent added) could thus be achieved. Immobilization of Arthrobacter simplex in cross-linked polyacrylamide hydrazide gave high retentions of activity. PMS exhibited toxic effects on the entrapped cells, leading to reduced activity after extended use.     

Serial reconstruction and behaviour during cytokinesis of the chondriome ofProrocentrum minimum (Pavillard) Schiller (Pyrrhophyta)

Summary Serial reconstruction of the chondriome of vegetative cells ofProrocentrum minimum (Pavillard) Schiller has revealed a major reticulated mitochondrion and several small satellite mitochondria. During cytokinesis the major portion of the chondriome splits passively with the cell. The significance of this structure and division mechanism is discussed.