Metabolome analysis of differential responses of diploid and haploid yeast to ethanol stress

Metabolomic analysis was carried out to investigate the metabolic differences of diploid (α/a) and homogenous haploid (α,a) yeasts, and further assess their response to ethanol stress. The dynamic metabolic variations of diploid and haploid caused by 3 and 7% (v/v) ethanol stress were evaluated by gas chromatography coupled to time-of-flight mass spectrometry combined with statistical analysis. Metabolite profiles originating from three strains in presence/absence of ethanol stress were distinctive and could be distinguished by principal components analysis. Results showed that the divergence among the strains with ethanol stress was smaller than without it. Furthermore, the levels of most glycolytic intermediates and amino acids in haploid were lower than these in diploid with/without ethanol stress, which was considered as species-specific behaviors. The increases of protective metabolites including polyols, amino acids, precursors of phospholipids, and unsaturated fatty acids under ethanol stress in three strains revealed the ethanol stress-specific responses. Higher fold change in most of these protectants in haploid indicated that haploid was more susceptible to ethanol stress than diploid. These findings provided underlying basis for better understanding diploid and haploid yeasts, and further breeding tolerant strains for efficient ethanol fermentation.     

水貂GH基因SNP_S与皮张长度的相关性研究

以水貂生长激素(GH)基因作为控制水貂皮张长度性状主基因的候选基因,以大兴安岭水貂养殖基地养殖的水貂群为试验材料,通过PCR-SSCP方法对GH基因进行多态性检测。在该基因内含子1中发现1处碱基突变:C→A,并检测到3种基因型(AA、AB、BB),BB基因型个体与AA基因型个体皮张长度有一定的差异(P0.05)。在外显子2中发现2处碱基突变:T→A、C→G,并由此检测到了3种基因型,分别命名CC、CD、DD,但3种基因型对水貂皮长的影响没有显著的差异(P0.05)。统计各基因型之间的组合给水貂皮长带来的影响时,发现多数组合基因型对所检测的水貂皮长有显著影响(P0.05)。     

Systematic analysis of biochemical performance and the microbial community of an activated sludge process using ozone-treated sludge for sludge reduction

Two lab-scale bioreactors (reactors 1 and 2) were employed to examine the changes in biological performance and the microbial community of an activated sludge process fed with ozonated sludge for sludge reduction. During the 122 d operation, the microbial activities and community in the two reactors were evaluated. The results indicated that, when compared with the conventional reactor (reactor 1), the reactor that was fed with the ozonated sludge (reactor 2) showed good removal of COD, TN and cell debris, without formation of any excess sludge. In addition, the protease activity and intracellular ATP concentration of reactor 2 were increased when compared to reactor 1, indicating that reactor 2 had a better ability to digest proteins and cell debris. DGGE analysis revealed that the bacterial communities in the two reactors were different, and that the dissimilarity of the bacterial population was nearly 40%. Reactor 2 also contained more protozoa and metazoa, which could graze on the ozone-treated sludge debris directly.     

Characterization of eight polymorphic microsatellite loci for the leopard coralgrouper (Plectropomus leopardus Lacepède)

Eight polymorphic microsatellite loci were isolated and characterized from a microsatellite DNA-enriched DNA library for the leopard coralgrouper (Plectropomus leopardus Lacepède, 1802), a popular food fish in the East Indies. These loci showed polymorphism information content ranging from 0.493 to 0.854, allele numbers ranging from 3 to 10, effective allele numbers ranging from 2.2 to 7.6, and observed and expected heterozygosities from 0.375 to 0.906 and 0.544 to 0.868 respectively. Thus, we expect that these markers will be useful for population genetic and breeding studies of the leopard coralgrouper.     

Intein-Mediated Protein trans-Splicing of the Recombinant Streptavidin on Magnetosomes

Molecular Biology - When expressing streptavidin recombinant polypeptide on magnetosomes (called bacterial magnetic nanoparticles, or BMPs), the presence of endogenous bacterial biotin might be...     

几种经济作物根际拮抗细菌的多样性

采用抗菌谱测定以及BOXAIR-PCR、生理生化特征和16S rDNA序列分析等方法对分离自10种作物根际的55株拮抗细菌的多样性及主要拮抗菌类群进行了分析.结果表明： 根际拮抗细菌的拮抗作用具有丰富的多样性;BOXAIR-PCR分析中供试菌在721％相似性水平上可以聚为7个群,850%相似性水平上聚为25个群;所有供试根际拮抗菌分别属于芽孢杆菌属（Bacillus）芽孢杆菌属（Paenibacillus）、短芽孢杆菌属（Brevibacillus）、假单胞菌属（Pseudomonas）和产碱菌属（Alcaligenes）.作物根际拮抗菌具有丰富的遗传多样性和拮抗性能多样性.     

Promises of Main Group Metal–Based Nanostructured Materials for Electrochemical CO2 Reduction to Formate

Selective CO₂ reduction to formic acid or formate is the most technologically and economically viable approach to realize electrochemical CO₂ valorization. Main group metal–based (Sn, Bi, In, Pb, and Sb) nanostructured materials hold great promise, but are still confronted with several challenges. Here, the current status, challenges, and future opportunities of main group metal–based nanostructured materials for electrochemical CO₂ reduction to formate are reviewed. Firstly, the fundamentals of electrochemical CO₂ reduction are presented, including the technoeconomic viability of different products, possible reaction pathways, standard experimental procedure, and performance figures of merit. This is then followed by detailed discussions about different types of main group metal–based electrocatalyst materials, with an emphasis on underlying material design principles for promoting the reaction activity, selectivity, and stability. Subsequently, recent efforts on flow cells and membrane electrode assembly cells are reviewed so as to promote the current density as well as mechanistic studies using in situ characterization techniques. To conclude a short perspective is offered about the future opportunities and directions of this exciting field.     

SARS病毒巨细胞病毒合并感染真菌及其染色方法的应用比较

目的几种染色方法显示星形隐球菌和曲菌的比较。方法Grocott-Gomori六胺银改良法,Gomori氏嗜银法和PAS结果Grocott-Gomori氏六胺银改良法显示上述两种真菌效果最好,该法对真菌的显示颜色鲜艳,图像清晰,真菌的孢子和菌丝被染成深黑色,易与其它成份相区别;Gomori氏嗜银法对大量含有菌丝的组织有一定的染色效果,PAS法也能将上述两种真菌显示出来,但所着染成份较多,较难区别。结论Grocott-Gomori氏六胺银改良法是染真菌的最好方法。     

木质纤维素预处理技术研究进展

详细评述了木质纤维素的预处理工艺研究进展,特别是浓酸低温水解-酸回收工艺、稀酸二阶段水解工艺、金属离子在稀酸水解过程中的助催化作用以及水蒸汽爆裂、氨纤维爆裂、CO2爆裂、酶催化水解等方法的研究进展情况。木质纤维素原料预处理技术发展为发酵生产乙醇技术的研究开发奠定了坚实基础。