Heterologous expression of Aspergillus oryzae xylose reductase and xylitol dehydrogenase genes facilitated xylose utilization in the yeast Saccharomyces cerevisiae

The cDNA encoding a putative xylose reductase (xyrA) from Aspergillus oryzae was cloned and coexpressed in the yeast Saccharomyces cerevisiae with A. oryzae xylitol dehydrogenase cDNA (xdhA). XyrA exhibited NADPH-dependent xylose reductase activity. The S. cerevisiae strain, overexpressing the xyrA, xdhA, endogenous XKS1, and TAL1 genes, grew on xylose as sole carbon source, and produced ethanol.     

Ameliorating effects of short-chain inulin-like fructans on the healing stage of trinitrobenzene sulfonic acid-induced colitis in rats

We evaluated the ameliorating effects of short-chain inulin-like fructans (SIF) with different degrees of polymerization (DP) on the healing stage of trinitrobenzene sulfonic acid (TNBS)-induced colitis in rats. The rats were assigned to 3 groups 10 d after the colitis induction, and fed for 24 d on a control diet or diet including 60 g of DP4 or DP8/kg. The fecal myeloperoxidase (MPO) activity and IgA concentration were monitored every 7 d. The colonic MPO activities and cecal concentrations of organic acids, lactobacilli, bifidobacteria, mucin and IgA were measured at the end of the study. DP4, but not DP8, significantly reduced the colonic inflammation accompanied by higher cecal concentrations of short-chain fatty acids, propionate in particular, and lactic acid-producing bacteria. DP4 therefore accelerated the healing process of TNBS-induced colitis, even when the treatment was initiated after inducing colitis.     

Transcriptome and growth efficiency comparisons of recombinant thermophiles that produce thermolabile and thermostable proteins: implications for burden-based selection of thermostable proteins

Extremophiles - Geobacillus kaustophilus is a thermophilic bacterium that grows at temperatures ranging between 42 and 74 °C. Here, we modified this organism to produce the...     

Differences in intracellular mobile zinc levels affect susceptibility to plasma-activated medium-induced cytotoxicity

There is growing evidence that plasma-activated medium (PAM), which is prepared by non-thermal plasma (NTP) irradiation of cell-free medium, is a beneficial tool for cancer therapy. PAM has been reported to preferentially kill cancer cells; however, its mechanism is not fully understood. Since PAM contains reactive oxygen species (ROS) and reactive nitrogen species, the anti-cancer effects of PAM are thought to be attributed to oxidative stress induced by these reactive molecules. Oxidative stress has been shown to release zinc (Zn²⁺) from intracellular Zn²⁺ stores and provoke Zn²⁺-dependent cell death. We have previously demonstrated that intracellular free Zn²⁺ plays a critical role in PAM-induced cell death in human neuroblastoma SH-SY5Y cells. In this study, we found that normal human fibroblasts were less susceptible to PAM cytotoxicity compared with SH-SY5Y cells. PAM decreased intracellular NAD⁺ levels in both cells, whereas the depletion of ATP and mitochondrial ROS generation was hardly observed in fibroblasts. Intracellular mobile Zn²⁺ contents of fibroblasts were lower than those of SH-SY5Y cells. PAM suppressed the activity of aconitase, which is a tricarboxylic acid cycle enzyme, only in SH-SY5Y cells, and N,N,N′,N′-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN), a Zn²⁺ chelator, counteracted the suppression. The combination treatment with PAM and Zn²⁺ augmented PAM-induced ATP depletion, mitochondrial ROS generation, and cytotoxicity in fibroblasts. These findings suggest the possibility that cells with high intracellular mobile Zn²⁺ are susceptible to PAM cytotoxicity. Therefore, we concluded that the differences in mobile Zn²⁺ levels affect PAM-induced cellular responses.     

Suppression of aphids by augmentative release of larvae of flightless Harmonia axyridis

The release of the larvae of flightless ladybird beetles could extend the duration of effective control because of the longer presence of adult stages, and the per individual production cost for juvenile stages is lower than that for adult stages. A preliminary release experiment was conducted to assess the effectiveness in controlling two aphid species, Aphis gossypii and Aulacorthum solani, using second instars of a flightless strain of Harmonia axyridis. The number of A. gossypii was suppressed in greenhouses that contained the flightless strain compared with greenhouses that contained the wild‐type strain. In one of two replicates, more flightless adults were observed on the plants for longer than wild‐type adults. However, it was not clear whether the extension of the residence period contributed to the effectiveness in controlling aphids directly, because the population of ladybirds in the greenhouses consisted of both larvae and adults during parts of the experimental period. In flightless H. axyridis, the release of larvae was more effective in suppressing A. solani than the release of adults. These results suggest that it may be more effective to release larvae of flightless H. axyridis than wild‐type larvae or flightless adults.