Acceptor specificity of cyclodextrin glycosyltransferase from Bacillus stearothermophilus and synthesis of alpha-D-glucosyl O-beta-D-galactosyl-(1----4)-beta-D-glucoside.

Bacillus stearothermophilus CGTase had a wider acceptor specificity than Bacillus macerans CGTase did and produced large amounts of transfer products of various acceptors such as D-galactose, D-mannose, D-fructose, D- and L-arabinose, D- and L-fucose, L-rhamnose, D-glucosamine, and lactose, which were inefficient acceptors for B. macerans CGTase. The main component of the smallest transfer products of lactose was assumed to be alpha-D-glucosyl O-beta-D-galactosyl-(1----4)-beta-D-glucoside.     

Trp residue at subsite − 5 plays a critical role in the substrate binding of two protistan GH26 β-mannanases from a termite hindgut

Applied Microbiology and Biotechnology - Symbiotic protists in the hindgut of termites provide a novel enzymatic resource for efficient lignocellulytic degradation of plant biomass. In this study,...     

Evidence for a humoral factor mediating the effect of a pressure load on lysine incorporation in rabbit heart

The M1 and M2 isozymes of pyruvate kinase from several mammalian species were compared in their reactivity toward monoclonal anti-pyruvate kinase antibodies and by one and two-dimensional peptide mapping. Inter-species differences between the M2 isozymes were always accompanied by similar interspecies differences in the M1 isozymes, supporting the conclusion that these two isozymes are the products of the same gene.     

Effects of environmental factors upon variation in soil respiration of a Zoysia japonica grassland, central Japan

The effects of environmental factors on seasonal and annual variations in soil respiration were examined in the cool temperate Zoysia japonica grassland of Japan. Field measurements of soil respiration were conducted using a closed chamber method with an infrared gas analyzer at monthly intervals in the snow-free seasons from May 2007 to December 2009. There was an exponential relationship between soil respiration and soil temperature, and the soil temperature accounted for 85–86% of seasonal soil respiration variability. Moreover, a positive linear relationship between soil respiration and soil water content was detected in summer (R ² = 0.55, p < 0.001), but not in spring or autumn. Annual soil respiration was estimated at 755, 719, and 1,037 g C m⁻² year⁻¹ in 2007, 2008, and 2009, respectively. These interannual variations in soil respiration might be influenced by the strength of precipitation during rainy seasons and the timing of each snow-melt. Our results suggest that the effects of rainfall and snow-melt events on soil respiration might be important factors to understand carbon dynamics in grassland ecosystem in Japan.     

Extracellular product of Nocardia amarae induces bacterial cell flocculation

The fact that Nocardia amarae YK1 produced a bacterial flocculation-inducing substance (designated as FIX) was discovered. FIX had a function of flocculating proliferous cells. FIX-induced flocculation was inhibited by making cells resting, but not completely by adding chloramphenicol. FIX worked widely on Gram-positive to -negative bacteria. In the presence of FIX, Achromobacter cycloclastus IAM1013, Acinetobacter calcoaceticus IAM1517, Bacillus subtilis IAM1069, Escherichia coli C600-1, E. coli IAM1239, Flavobacterium lutescens IAM1667, Klebsiella pneumoniae IAM1102, Micrococcus luteus IAM1313 and Pseudomonas putida IAM1002 formed flocs. B. cereus IAM1029, however, exhibited no flocculation.     

Ammonium stress increases microautophagic activity while impairing macroautophagic flux in Arabidopsis roots

Plant responses to NH₄ ⁺ stress are complex, and multiple mechanisms underlying NH₄ ⁺ sensitivity and tolerance in plants may be involved. Here, we demonstrate that macro- and microautophagic activities are oppositely affected in plants grown under NH₄ ⁺ toxicity conditions. When grown under NH₄ ⁺ stress conditions, macroautophagic activity was impaired in roots. Root cells accumulated autophagosomes in the cytoplasm, but showed less autophagic flux, indicating that late steps of the macroautophagy process are affected under NH₄ ⁺ stress conditions. Under this scenario, we also found that the CCZ1-MON1 complex, a critical factor for vacuole delivery pathways, functions in the late step of the macroautophagic pathway in Arabidopsis. In contrast, an accumulation of tonoplast-derived vesicles was observed in vacuolar lumens of root cells of NH₄ ⁺-stressed plants, suggesting the induction of a microautophagy-like process. In this sense, some SYP22-, but mainly VAMP711-positive vesicles were observed inside vacuole in roots of NH₄ ⁺-stressed plants. Consistent with the increased tonoplast degradation and the reduced membrane flow to the vacuole due to the impaired macroautophagic flux, the vacuoles of root cells of NH₄ ⁺-stressed plants showed a simplified structure and lower tonoplast content. Taken together, this study presents evidence that postulates late steps of the macroautophagic process as a relevant physiological mechanism underlying the NH₄ ⁺ sensitivity response in Arabidopsis, and additionally provides insights into the molecular tools for studying microautophagy in plants.