Characterization of a Galactose Oxidase from Fusarium odoratissimum and Its Application in the Modification of Agarose.

A galactose oxidase gene, gao-5f, was cloned from Fusarium odoratissimum and successfully expressed in E. coli. The galactose oxidase GAO-5F belongs to the AA5 family and consists of 681 amino acids, with an estimated molecular weight of 72 kDa. GAO-5F exhibited maximum activity at 40 °C and pH 7.0 and showed no change in activity after 24 h incubation at 30 °C. Moreover, GAO-5F exhibited 40% of its maximum activity after 24 h incubation at 50 °C and 60% after 40 h incubation at pH 7.0. The measured thermostability of GAO-5F is superior to galactose oxidase's reported thermostability. The enzyme exhibited strict substrate specificity toward D-galactose and oligosaccharides/polysaccharides containing D-galactose. Further analysis demonstrated that GAO-5F specifically oxidized agarose to a polyaldehyde-based polymer, which could be used as a polyaldehyde to crosslink with gelatin to form edible packaging films. To our knowledge, this is the first report about the modification of agarose by galactose oxidase, and this result has laid a foundation for the further development of edible membranes using agarose.

Indigenous yeast can increase the phenolic acid and volatile ester compounds in Petit Manseng wine.

Introduction: Indigenous yeasts are generally found in grapes, vineyards, and natural environments. Sequential inoculation and fermentation with non-Saccharomyces cerevisiae yeast (H30) and Saccharomyces cerevisiae (YT13) also improve the flavor of wine. Methods: This study sequentially inoculated fermented Petit Manseng and natural grape juice with native H30 and YT13 selected from vineyards in Yantai, China. Results and discussion: The sensory characteristics of Petit Manseng wine were evaluated by detecting the primary organic acids, phenolic acid compounds, and volatile ester compounds. The results showed that the lactic acid content of the natural wine fermented sequentially with H30 and YT13 increased by 490 µg/L compared with the control group, while the ferulic acid content was 1.4 times that of the single-yeast fermentation group. Furthermore, butyrolactone and anthocyanidin propionate were present in the mixed fermentation group, increasing the aroma complexity of Petit Manseng wine and providing high-quality yeast resources that increase the regional characteristics when producing dry white wine.

[Effects of irrigation and planting patterns on photosynthetic characteristics of flag leaf and yield at late growth stages of winter wheat].

High-yield winter wheat cultivar Jimai 22 was used to study effects of irrigation and planting patterns on water consumption characteristics and photosynthetic characteristics of winter wheat in field from 2009 to 2011. Three different planting patterns (uniform row, wide-narrow row and furrow) and four irrigation schedules (W0, no irrigation; W1, irrigation at jointing stage; W2, irrigations at jointing and anthesis stages; W3, irrigation at jointing, anthesis and milking stages. Each irrigation rate was 60 mm) were designed in the experiment. Results showed that, with the increasing of irrigation amount, flag leaf area, net photosynthesis rate, maximum photochemical efficiency and actual light transformation efficiency at late growth stages of winter wheat increased. Compared with W0 treatment, the other irrigation treatments had higher grain yields, but lower water use efficiencies. Under the same irrigation condition, the flag leaf net photosynthesis, maximum photochemical efficiency and actual light transformation efficiency were much higher in furrow pattern. Grain yields of winter wheat under furrow pattern and W2 treatment were significantly higher than that of the other treatments. Taking grain yield and WUE into consideration, furrow pattern combined with irrigation at jointing and anthesis stages might be the optimal water-saving and planting mode for the winter wheat production in North China Plain.