Molecular Biology Reports - The accumulation of soluble sugars in fleshy fruits largely determines their sweetness or taste. A spontaneous sweet orange mutant ‘Hong Anliu’ (HAL, Citrus... 相似文献
Higher alcohol isobutanol is a promising liquid fuel. During alcoholic fermentation, Saccharomyces cerevisiae produces only trace amounts of isobutanol. Screening the collection of nonconventional yeasts show that Magnusiomyces magnusii accumulates 440 mg of isobutanol per L in rich YPD medium. Here, the transformation protocol for M. magnusii is adapted based on the use of the dominant markers conferring resistance to nourseothricin or zeocin; the strong constitutive promoter TEF1 is cloned and a reporter system based on LAC4 gene from Kluyveromyces lactis coding for β‐galactosidase is constructed. In order to increase isobutanol production in M. magnusii, the heterologous gene ILV2 from S. cerevisiae is expressed in M. magnusii under control of the TEF1 promoter. The best stabilized transformants produce 620 mg of isobutanol per L in YPD medium and 760 mg L?1 in the medium with 2‐oxoisovalerate. This suggests that M. magnusii is a promising organism for further development of a robust isobutanol producer. 相似文献
Synbiotic (probiotic bacteria and prebiotic) has beneficial effects on the gastrointestinal tract. This study was designed to investigate the effect of synbiotic supplementation on the growth of mild to moderate failure to thrive (FTT) children. A randomized, triple-blind, placebo-controlled trial was conducted involving 80 children aged 2–5 years with mild to moderate FTT, who were assigned at random to receive synbiotic supplementation (109 colony-forming units) or placebo for 30 days. The weights, height, and BMI were recorded in a structured diary, and the questionnaires were completed to monitor the numbers of infection episodes, gastrointestinal problems, admission to hospital, and appetite improvement during the study. Sixty-nine children completed the study. There were no differences in the demographic characteristic between the two groups. The mean weight was similar at baseline. After 30 days of intervention, the mean weight of the participants in the synbiotic group increased significantly than those in the placebo group (600?±?37 vs. 74?±?32 g/month P 0.000). BMI changes in synbiotic and placebo group were 0.44 and 0.07 kg/m2, and that the differences among the two groups were significant.(P 0.045) Furthermore, the height increment in synbiotic and placebo group was 0.41 and 0.37 cm respectively with no significant difference (P 0.761). Administration of 30-day synbiotic supplementation may significantly improve weight and BMI in Iranian children with mild to moderate FTT, but there is no effect on the height in this study. Further studies should be designed to found out the effect of synbiotic on growth parameters in undernourished and well-nourished children.
Previous research demonstrated that aflatoxin contamination in corn is reduced by field application of wheat grains pre-inoculated with the non-aflatoxigenic Aspergillus flavus strain NRRL 30797. To facilitate field applications of this biocontrol isolate, a series of laboratory studies were conducted on the reliability and efficiency of replacing wheat grains with the novel bioplastic formulation Mater-Bi® to serve as a carrier matrix to formulate this fungus. Mater-Bi® granules were inoculated with a conidial suspension of NRRL 30797 to achieve a final cell density of approximately log 7 conidia/granule. Incubation of 20-g soil samples receiving a single Mater-Bi® granule for 60-days resulted in log 4.2–5.3 propagules of A. flavus/g soil in microbiologically active and sterilized soil, respectively. Increasing the number of granules had no effect on the degree of soil colonization by the biocontrol fungus. In addition to the maintenance of rapid vegetative growth and colonization of soil samples, the bioplastic formulation was highly stable, indicating that Mater-Bi® is a suitable substitute for biocontrol applications of A. flavus NRRL 30797. 相似文献
Metallothionein (MT) concentration in gills, liver, and kidney tissues of Persian sturgeon (Acipenser persicus) were determined following exposure to sublethal levels of waterborne cadmium (Cd) (50, 400, and 1,000 μg l−1) after 1, 2, 4, and 14 days. The increases of MT from background levels were 4.6-, 3-, and 2.8-fold for kidney, liver, and
gills, respectively. The results showed that MT level change in the kidney is time and concentration dependent. Also, cortisol
measurement revealed elevation at the day 1 of exposure and followed by MT increase in the liver. Cd concentrations in the
cytosol of experimental tissues were measured, and the results indicated that Cd levels in the cytosol of liver, kidney, and
gills increased 240.71-, 32.05-, and 40.16-fold, respectively, 14 days after exposure to 1,000 μg l−1 Cd. The accumulation of Cd in cytosol of tissues is in the order of liver > gills > kidney. Pearson correlation coefficients
showed that the MT content in kidney is correlated with Cd concentration, the value of which is more than in liver and gills.
Thus, kidney can be considered as a tissue indicator in A. persicus for waterborne Cd contamination. 相似文献
The adsorption of helium and neon mixtures on single-walled carbon nanotubes (SWCNTs) was investigated at various temperatures
(subcritical and supercritical) and pressures using canonical Monte Carlo (CMC) simulation. Adsorption isotherms were obtained
at different temperatures (4, 40, 77 and 130 K) and pressures ranging from 1 to 16 MPa. Separation factors and isosteric enthalpies
of adsorption were also calculated. Moreover, the adsorption isotherms were obtained at constant specific temperatures (4
and 40 K) and pressures (0.2 and 1.0 MPa) as a function of the amount adsorbed. All of the adsorption isotherms for an equimolar
mixture of helium and neon have a Langmuir shape, indicating that no capillary condensation occurs. Both the helium and the
neon adsorption isotherms exhibit similar behavior, and slightly more of the helium and neon mixture is adsorbed on the inner
surfaces of the SWCNTs than on their outer surfaces. More neon is adsorbed than helium within the specified pressure range.
The data obtained show that the isosteric enthalpies for the adsorption of neon are higher than those for helium under the
same conditions, which means that adsorption of neon preferentially occurs by (15, 15) SWCNTs. Furthermore, the isosteric
enthalpies of adsorption of both gases decrease with increasing temperature. 相似文献
Myostatin is a negative regulator of the growth and development of skeletal muscle mass. In fish, myostatin is expressed in several organs in addition to skeletal muscle. To understand the mechanisms regulating myostatin gene expression in the sea perch, Lateolabrax japonicus, we examined the methylation status of the myostatin gene promoter region in several tissues (liver, eye, kidney, brain, and heart) isolated from adult specimens. The frequency of methylated cytosines was very low in all tissues, regardless of the level of myostatin expression, suggesting that DNA methylation is not involved in the tissue-specific regulation of myostatin expression. Southern blot analysis of genomic DNA obtained from micrococcal nuclease-treated nuclei showed that chromatin digestion occurs in tissues where the myostatin gene is actively transcribed and that the myostatin gene is protected from micrococcal nuclease in tissues where myostatin is not expressed. The chromatin structure in the myostatin gene region appears to regulate its expression without DNA methylation. 相似文献
Brewer's spent grain (BSG) was used as a solid substrate for the production of α-amylase by Bacillus sp. KR-8104 in a submerged fermentation system. The production of α-amylase was maximized through statistical optimization of the BSG concentration and incubation time using the Doehlert experimental design. The highest tested amount of BSG (5%, w/v) in the optimization process resulted in a 5.1-fold enhancement of the response. Subsequently, we studied the role of the water-soluble and -insoluble fractions of BSG in the production of α-amylase. The results revealed that whole BSG had a greater effect on the production of α-amylase than each fraction had separately. Finally, when we examined the potential of BSG to replace the constituents of a medium formula, we observed that simultaneously adding BSG, omitting dextrin, and reducing the other ingredients concentration in the culture medium improved the production of α-amylase and made the production process more economical. 相似文献