Effective Isolation and Identification of Toluene-tolerant Pseudomonas Strains

A total of 1752 strains of osmophilic yeasts were isolated from honey and pollens. Forty-three strains of osmophilic yeasts produced polyols, among which 6 strains produced erythritol in good yields. On the other hand, 52 osmophilic yeasts converted sucrose to fructooligosaccharides, among which 8 strains produced both extra and intracellular β-fructofuranosidase, which converted sucrose to fructooligosaccharides. This investigation concluded that osmophilic yeasts converted sucrose not only to polyols, but also to fructooligosaccharides in good yields.     

产赤藓糖醇菌种的诱变育种

以耐高渗酵母为出发菌株,采用紫外线诱变处理,得到了一株变异株C1。其摇瓶发酵产赤藓糖醇24．9g／L左右。通过摇瓶发酵试验,研究了菌株C1的遗传稳定性。研究结果表明,经多次传代实验,菌株C1的发酵产糖醇能力没有改变,表明其是稳定的变异株。赤藓糖醇的产量由诱变前的12、594g／L提高到24.943g／L,提高了98.1％。关键词：     

A Review of: “North-Holland Publishing Company,Amsterdam, New York,Oxford, 1976; Softbound, 290 pages, $ 19.25.”

Several factors affecting erythritol production from glycerol by Yarrowia lipolytica Wratislavia K1 strain were examined in batch fermentations. Ammonium sulfate, monopotassium phosphate, and sodium chloride were identified as critical medium components that determine the ratio of polyols produced. The central composite rotatable experimental design was used to optimize medium composition for erythritol production. The concentrations of ammonium sulfate, monopotassium phosphate, and sodium chloride in the optimized medium were 2.25, 0.22, and 26.4 g L^?1, respectively. The C:N ratio was found as 81:1. In the optimized medium with 100 g L^?1 of glycerol the Wratislavia K1 strain produced 46.9 g L^?1 of erythritol, which corresponded to a 0.47 g g^?1 yield and a productivity of 0.85 g L^?1 hr^?1. In the fed-batch mode and medium with the total concentration of glycerol at 300 g L^?1 and C:N ratio at 81:1, 132 g L^?1 of erythritol was produced with 0.44 g g^?1 yield and a productivity of 1.01 g L^?1 hr^?1.     

Scale-up of erythritol production by an osmophilic mutant of Candida magnoliae

Erythritol production by an osmophilic mutant of Candida magnoliae was performed in fermentations of up 50 l to develop an optimized commercial process. By simultaneous feeding glucose and yeast extract, erythritol productivity of 1.2 g l(-1) h(-1) was reached giving 200 g erythritol l(-1) with a yield of 0.43 g g(-1).     

Optimization of the transient transformation of <Emphasis Type="Italic">Catharanthus roseus</Emphasis> cells by particle bombardment and its application to the subcellular localization of hydroxymethylbutenyl 4-diphosphate synthase and geraniol 10-hydroxylase

The monoterpene indole alkaloids (MIA) synthesized in Catharanthus roseus are highly valuable metabolites due to their pharmacological properties. In planta, the MIA biosynthetic pathway exhibits a complex compartmentation at the cellular level, whereas subcellular data are sparse. To gain insight into this level of organization, we have developed a high efficiency green fluorescent protein (GFP) imaging approach to systematically localize MIA biosynthetic enzymes within C. roseus cells following a biolistic-mediated transient transformation. The biolistic transformation protocol has been first optimized to obtain a high number of transiently transformed cells with a ~12-fold increase compared to previous protocols and thus to clearly and easily identify the fusion GFP expression patterns in numerous cells. On the basis of this protocol, the subcellular localization of hydroxymethylbutenyl 4-diphosphate synthase (HDS), a methyl erythritol phosphate pathway enzyme and geraniol 10-hydroxylase (G10H), a monoterpene-secoiridoid pathway enzyme has been next characterized. Besides showing the accumulation of HDS within plastids of C. roseus cells, we also provide evidences of the presence of HDS in long stroma-filled thylakoid-free extensions budding from plastids, i.e. stromules that are in close association with other organelles such as endoplasmic reticulum (ER) or mitochondria in agreement with their proposed function in enhancing interorganelle metabolite exchanges. Furthermore, we also demonstrated that G10H is an ER-anchored protein, consistent with the presence of a transmembrane helix at the G10H N-terminal end, which is both necessary and sufficient to drive the ER anchoring. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Increased erythritol production in Torula sp. with inositol and phytic acid

Of the vitamins tested, inositol was the most effective for erythritol production. To increase erythritol production by Torula sp., inositol and a related compound, phytic acid (myoinositol hexaphosphate), were added to the culture media. Erythritol production in the presence of phytic acid was greater than that in the presence of inositol, due to the synergistic effects of phosphate and inositol. Supplementation with phosphate and inositol increased cell growth, erythritol production, and the activity of erythrose reductase in cells. Inositol was a more effective stimulator of cell growth and erythritol production than was phosphate.     

甘氨酸和赤藓糖醇胶饵对红火蚁工蚁的毒杀效果

前期研究发现甘氨酸和赤藓糖醇对红火蚁Solenopsis invicta Buren有较好的毒杀效果,为进一步挖掘这两种物质的实际应用价值,在室内测试了甘氨酸和赤藓糖醇不同浓度配比的水溶液及胶状饵剂对红火蚁工蚁的毒杀效果.结果显示,20％的配比为1∶3、3∶1的赤藓糖醇和甘氨酸溶液喂饲48 h红火蚁工蚁的死亡率分别为83.1％和84.93％,而72h后,死亡率分别为95.07％和95.21％,与取食茚虫威饵剂的工蚁死亡率(48 h:92.57％;72 h:100％)无显著差异.20％的配比为1∶3、3∶1的赤藓糖醇和甘氨酸水凝胶颗粒喂饲48 h红火蚁工蚁的死亡率分别为58.94％和55.05％,而72 h后,死亡率分别为85.11％和80.05％,显著低于取食茚虫威饵剂的工蚁死亡率(48 h:95.71％;72 h:99.59％).研究结果为进一步利用开发红火蚁环保型饵剂提供参考.