Efficient utilization of ectoine by halophilic Brevibacterium species and Escherichia coli subjected to osmotic downshock

Halophilic and non-halophilic bacteria subjected to osmotic downshock, from 0.7 M NaCl to deionized water, were examined for their survival, with the uptake and utilization of the cyclic amino acid ectoine, one of the representative compatible solutes, being taken into account. The uptake of ectoine added externally and survival of the cells were monitored as a function of incubation time in the presence and absence of NaCl. The halophilic Brevibacterium sp. JCM 6894 and B. epidermidis JCM 2593 actively accumulated ectoine regardless of the presence of NaCl, which led to cell survival. Brevibacterium casei JCM 2594 belonging to the same Brevibacterium species, however, revealed Na+-dependence of its uptake activity of ectoine. Non-halophilic Escherichia coli K-12 did not accumulate ectoine, and thereby this strain failed to survive irrespective of whether NaCl was present. The physiological meanings of the downshock procedure are discussed in connection with the uptake and the subsequent utilization of ectoine.     

Experimental study on the free surface deformation in the oxide melt

1 Introduction The convective motion induced by local variations of surface tension along a liquid free surface is called Marangoni convection. Flows driven by a temperature gradient aligned parallel to the free surface are often named thermocapillary convection, which is often a dominating effect in material processing techniques. It is well known for the melt crystal growth that the thermocapillary convection becomes instable at high Marangoni numbers, which gives rise to temperature oscill…     

Effect of coal particle size on the coal hydrogenation reaction — In relation to the plasticity of coal

The effect of coal particle size on the catalytic hydrogenation of dry coal was investigated for three Hokkaido coals (Japan) of different ranks. It was found that the effect of coal particle size on conversion is dependent on coal rank. A greater difference in conversion with respect to coal particle size is noticed for coals of lower carbon content. The physical appearance of the products in the autoclave after the reaction suggests that the effect of particle size on conversion is dependent on the plastic properties of the heated coal sample. When the reaction proceeds with coal in the plastic state, the effect of particle size is small. As indicated by the product distribution, the plastic properties of a coal sample are related to the yield of asphaltene (hexane insoluble/benzene solubles) and/or the structural parts of original coal which yield asphaltene.     

Change of pore properties during carbonization of coking coal

Porosimetry, sorption and density measurements are reported on two caking bituminous coals, West Virginia Jewel No. 2 medium volatile and a Pennsylvania Pittsburgh seam high volatile C, for final carbonization temperatures between 400 and 1000°C. Samples were not confined and heating rates of 3 and 8.2°/min were employed. The medium volatile samples exhibit pronounced maxima in pore volume, pore surface area and porosity between 600 and 800°C. These temperatures are considerably greater than the characteristic temperature and the temperature at which maximum dilation occurs. The high volatile C coal does not exhibit well defined maxima. Results are interpreted in terms of pore development mechanisms. A mathematical model for pore development is proposed and shown to correlate satisfactorily, the pore volume and surface area measurements.     

Production of Xylanase with a transformant of Aspergillus oryzae RIB40 in a Liquid-Surface Immobilization (LSI) System

Xylanase production by a XynF1 (33 kDa)-transformant of Aspergillus oryzae RIB40 was compared between submerged cultivation (SmC) and liquid-surface immobilization (LSI) systems. While the accumulation of xylanase in the SmC decreased by prolonged incubation, LSI system enabled the continuation of xylanase production to afford 4.5-fold xylanase production compared with the SmC system.     

Lactose enhances cellulase production by the filamentous fungus Acremonium cellulolyticus

Acremonium cellulolyticus is a fungus that produces cellulase and has been exploited by enzyme industry. To promote cellulase production by A. cellulolyticus strain C-1, we evaluated the effects of the saccharides: Solka Floc (cellulose), soluble soybean polysaccharide (SSPS), pullulan, lactose, trehalose, sophorose, cellobiose, galactose, sorbose, lactobionic acid, and mixtures as carbon sources for cellulase production. Solka Floc with SSPS enhanced cellulase production. Lactose as the sole carbon source induced cellulase synthesis in this fungus, and the synergistic effects between lactose and Solka Floc was observed. Various enzyme activities and the protein composition of crude enzyme produced by cultures with or without addition of lactose were analyzed. The results showed that lactose addition greatly improves the production of various proteins with cellulase activity by A. cellulolyticus. To our knowledge, this is the first report on production of cellulases by lactose in the A. cellulolyticus.