Desulfurization of model and diesel oils by resting cells of Gordona sp.

The desulfurization activity of the resting cells of Gordona sp. CYKS1 was strongly depended on harvest time and the highest value when the cells had been harvested in the early growth phase (0.12 mg sulfur g^–1 cell^–1 h^–1). For the model oil, hexadecane containing dibenzothiophene, the specific desulfurization rate decreased as the reaction proceeded. Both the specific and the volumetric desulfurization rates were not significantly affected by the aqueous-to-oil phase ratio. The diesel oils, light gas oil and a middle distillate unit feed were desulfurized at higher rates (ca. 0.34 mg sulfur g^–1 cell^–1 h^–1) than the model oil (0.12 mg sulfur g^–1 cell^–1 h^–1).     

Expression of mosquitocidal crystal protein genes in non-insecticidal Bacillus thuringiensis subsp. israelensis

Bacillus thuringiensis NTB-1 isolated from soil samples in Korea produces ovoidal parasporal inclusions with proteins of approximately 24–40 kDa in size. Although serological study indicated that the isolate has a flagella (H) antigen identical with subsp. israelensis , it seemed to be non-insecticidal against Lepidoptera and Coleoptera as well as Diptera. To investigate the activity of non-insecticidal B. thuringiensis transformed with insecticidal crystal protein genes, cryIVD and cytA genes of B. thuringiensis subsp. morrisoni PG-14, highly toxic to mosquito larvae, were introduced into the isolate NTB-1. The expression of mosquitocidal crystal protein genes in NTB-1 was characterized by SDS–PAGE analysis and electron microscopy. The results showed that crystalline inclusions of host, CryIVD and CytA were stably expressed in the transformant. However, the mosquitocidal activity of transformant was similar to that of B. thuringiensis subsp. kurstaki Cry⁻ B harbouring cryIVD and cytA genes, demonstrating that a synergistic effect by an interaction of both introduced insecticidal and resident non-insecticidal crystal proteins was not observed.     

Characterization of a cDNA encoding cysteine proteinase inhibitor from Chinese cabbage (Brassica campestris L. ssp. pekinensis) flower buds

A cDNA encoding a new phytocystatin isotype named BCPI-1 was isolated from a cDNA library of Chinese cabbage flower buds. The BCPI-1 clone encodes 199 amino acids resulting in a protein much larger than other known phytocystatins. BCPI-1 has an unusually long C-terminus. A BCPI-1 fusion protein expressed in Escherichia coli strongly inhibits the enzymatic activity of papain, a cysteine proteinase. Genomic Southern blot analysis revealed that the BCPI gene is a member of a small multi-gene family in Chinese cabbage. Northern blot analysis showed that it is differentially expressed in the flower bud, leaf and root.     

Bacterioplankton interactions with Daphnia and algae in experimental enclosures

Development of bacterioplankton was studied by manipulation of planktivorous fish and/or nutrients in experimental enclosures in a fish pond. Grazing pressure exerted by large zooplankton (Daphnia galeata and Daphnia pulicaria) strongly influenced the counts and size distribution of bacterial populations. Morphometric analyses by scanning electron microscope revealed a shift in size distribution from larger mainly rod-type bacteria under low grazing pressure towards smaller mainly coccus-type under strong grazing pressure. The metabolic activity of bacteria measured as glucose uptake was higher under strong grazing pressure. After removal of large daphnids, the increase in bacterial density was probably the result of two additive factors: low grazing pressure and high level of dissolved organic matter (DOM) due to photosynthetic activity of more abundant algae. Composition of bacterial populations shifted toward larger, rod-type bacteria, and their metabolic efficiency measured by uptake, was lowered. The basic dimensionality of the system and interactions between variables was describe by R-mode factor analysis. The manipulated enclosures were relate with factor score.     

The PiGMaP consortium linkage map of the pig (Sus scrofa)

A linkage map of the porcine genome has been developed by segregation analysis of 239 genetic markers. Eighty-one of these markers correspond to known genes. Linkage groups have been assigned to all 18 autosomes plus the X Chromosome (Chr). As 69 of the markers on the linkage map have also been mapped physically (by others), there is significant integration of linkage and physical map data. Six informative markers failed to show linkage to these maps. As in other species, the genetic map of the heterogametic sex (male) was significantly shorter (16.5 Morgans) than the genetic map of the homogametic sex (female) (21.5 Morgans). The sex-averaged genetic map of the pig was estimated to be 18 Morgans in length. Mapping information for 61 Type I loci (genes) enhances the contribution of the pig gene map to comparative gene mapping. Because the linkage map incorporates both highly polymorphic Type II loci, predominantly microsatellites, and Type I loci, it will be useful both for large experiments to map quantitative trait loci and for the subsequent isolation of trait genes following a comparative and candidate gene approach.     

New taxol assay method using tubulin-assembly stimulation

Summary A novel taxol determination method which involves the tubulin-assembly stimulation is described. The tubulin-assembly was monitored by turbidity change at 350nm. In a limited range of taxol concentration (0 to 24 M), taxol stimulated tubulin-assembly linearly. And this linear relation was observed from 20min to 30min after the reaction started. Bioactive derivatives of taxol, such as cephalomanin and 7-epi-10-deacetyltaxol also stimulated the tubulin-assembly. However, baccatin III, which was known as less active taxol derivative did not stimulate tubulin assembly. This result showed that the stimulation of tubulin assembly has a relationship with the antimiotic activity. This assay method have several advantages. 1) Time required for the measurement is relatively short. 2) Multiple samples can be measured simultaneously. 3) It can remove interference of less active taxane compounds more selectively than immuno-assay. Consequently, this method can be used to determine taxol concentration in biological samples. Especially, this method can be used for large scale selection of cell line and primary screening of new antimiotic compounds.     

Inhibition of tumor growth in mice treated with synthetic muramyl dipeptide

Summary Treatment with synthetic MDP inhibited growth of transplantable, chemically induced tumors in syngeneic mice. The tumor-inhibitory effect was dependent on the schedule of MDP administration.Growth of SC transplants of a nonmetastasizing, MC-induced fibrosarcoma, MC11, was inhibited by local treatment with 200 g and 1,000 g MDP given SC 5–7 weeks before challenge. Treatment with lower (10 g and 100 g) doses of MDP and shorter (1–4 weeks) time intervals was not effective. Single doses of MDP (10–1,000 g) 1–3 weeks after challenge had no effect.Growth of IV-inoculated, metastasizing AAT-induced hepatoma A was inhibited by IV injections of 20 g MDP given 1 and 2 days prior to the challenge. Significant increases in the survival of hepatoma-bearing mice were observed only after injections of MDP incorporated in multilamellar liposomes.Abbreviations MDP n-acetylmuramyl-l-alanyl-d-isoglutamine - B10 C57BL/10ScSnPh mice - MC 3-methylcholanthrene - ATT o-amino-azotoluene - PBS phosphate-buffered saline     

Expression of glucoamylase gene usingSUC2 promoter inSaccharomyces cerevisiae

Summary The cloning of glucoamylase geneSTA using theSUC2 promoter intoSaccharomyces cerevisiae was performed. The signal sequence ofSTA gene was used for the secretion of glucoamylase protein. The plasmid constructed in this way was named YEpSUCSTA and its expression was identified. The expression of YEpSUCSTA was repressed in the presence of glucose in growth medium, but derepressed when glucose became depleted. YEpSUCSTA showed the similar efficiency of glucoamylase secretion as YEpSTA-F which has the entireSTA gene. Glucoamylase activity in starch-glucose medium was largely increased because cell mass and plasmid stability were high in biosynthesis phase compared to extracellular glucoamylase activities in media which starch or glucose was the only carbon source.     

The structural stability of an expression plasmid bearing a heterologous cloned gene depends on whether this gene is expressed or not

Summary During subculturing of recombinant Escherichia coli under conditions blocking cloned gene expression the plasmid was structurally stable for 200 generations. However, under conditions permitting foreign gene expression only 10% of plasmid containing cells had this gene functional after 100 generations.