Sophorolipids from Torulopsis bombicola as microbial surfactants in alkane fermentations

The possible role of sophorolipids from Torulopsis bombicola was investigated in alkane fermentation. Sophorolipids and related model compounds specifically stimulated the growth of strains of Torulopsis yeasts on insoluble alkanes and may act as a specific growth factor. There may be more than one way for a yeast to be stimulated to incorporate alkanes for growth.     

Stimulating factor for calf thymus DNA polymerase β

A factor that stimulates purified DNA polymerase β about 2-fold was separated from DNA polymerase β activity on a DNA-cellulose column. During the early stage of purification, the factor may be associated with DNA polymerase β to form a complex that sediments at 3.9 S in sucrose gradients and behaved as a 52,000 dalton protein on a Sephadex G-100 column. The complex, which contains 40,000 and 12,500 dalton polypeptides, was insensible to the stimulator, and did not show any exonuclease activity.     

Performance of fluidized-bed reactors utilizing magnetic fields

The performance of fluidized-bed reactors utilizing a magnetic field was determined by the use of magnetite-containing beads of immobilized unease. The reactors showed similar or higher conversions in comparison with fixed-bed reactors, although some aggregation of the beads in the magnetic field was observed. No effusion of the beads occurred up to a flow rate of 24 cm/min.     

Performance of affinity chromatography columns

Performance of affinity chromatography columns was studied by measuring the rates of adsorption and elution of trypsin in a Sepharose 4B-soybean trypsin inhibitor column and a Sepharose 4B-arginine peptides column. The volumetric coefficient for trypsin transfer was evaluated from the break-through curves of trypsin, and elution profiles bed height of Sepharose 4B-STI column was estimated based on these results.     

Fractional precipitation of d-mannan from bakers' yeast with concanavalin a

The neutral component of d-mannan of bakers' yeast (Saccharomyces cerevisiae), consisting solely of d-mannose residues, was precipitated with concanavalin A to give four fractions. The first three displayed similar reactivities in quantitative precipitin reaction against concanavalin A and homologous anti-S. cerevisiae serum, but the fourth showed different precipitin curves. Analysis of the fractions by acetolysis indicated structural differences. The different behavior of the last fraction in precipitin reactions could be due to a lower content of branching points, or to shorter chain-lengths.     

Dystrophin in rod spherules; submembranous dense regions facing bipolar cell processes

 It is known that the retina contains the protein dystrophin in the ribbon synapse, but the ultrastructural analysis is not yet fully elucidated. Our previous study reported that dystrophin is localized under the rod cell membranes in rat retinas. In the present study, we have investigated the relationship between dystrophin-rich regions of rod cell membranes and other neuronal processes in mouse retinas with a monoclonal antibody raised against the human dystrophin C-terminus. Immunoblotting, immunofluorescence stainings, and immunoelectron microscopy were employed. Immunoblotting analysis indicated that mouse retinas possessed some of the dystrophin isoforms of approximately 260 kDa, 140 kDa, and 70 kDa molecular weight. Confocal images showed a punctate appearance in the outer plexiform layer, as previously described. Immunoelectron microscopy showed that dystrophin immunoreactive products were always observed at submembranous dense regions of the rod spherule abutting bipolar processes. These results suggest that retinal dystrophin may be closely involved in signal transmission from rods to bipolar cells. Accepted: 7 May 1997     

Structure Modifications of S-n-Butyl S′-p-tert-Butylbenzyl N-3-Pyridyldithiocarbonimidate (S–1358, Denmert®) and Fungicidal Activities

Since S-n-butyl S′-p-tert-butylbenzyl N-3-pyridyldithiocarbonimidate, a potent fungicide to powdery mildew, is known to inhibit ergosterol biosynthesis in Monilinia fructigena, the activities were assessed on 24 compounds having other substituents than the 3-pyridyl and on 24 compounds having a variety of different structures connecting the 3-pyridyl and the p-tert-butylphenyl group from that of the dithiocarbonimidate.

In the former group the 3-pyridyl group was essential for the activities and the substitution at the 2- or 6-position resulted, on available data, in inactive compounds. Several other β-N-heterocyclic analogs were also active. In the latter group, a number of modified compounds from the dithiocarbonimidate structure were shown to be active.     

Gelation of Limulus Lysate by Synthetic Dextran Derivatives

The Limulus test has been considered specific for the presence of bacterial endotoxins. To synthesize a simple model of endotoxin, palmitoyldextran phosphate was prepared by modification of dextran by palmitoylation and phosphorylation. The present studies indicated that a variety of polysaccharide derivatives, such as palmitoyldextran phosphate, palmitoyldextran, and dextran phosphate, give a positive Limulus test and show pyrogenic activity, except for low molecular dextran derivatives. On the other hand, polysaccharides, such as dextran, starch (soluble), chitosan, xylan, and lentinan, were negative in these assays. The gelation reaction of Limulus lysate by modified dextran derivatives may depend on the molecular weight or modification of polysaccharides by palmitoylation and/or phosphorylation to a great extent.