EMS诱变高异丁醇耐受性酿酒酵母的筛选

利用诱变剂甲基磺酸乙酯（EMS）对酿酒酵母（Saccharomyces cerevisiae）W303-1A进行诱变,确定了诱变酿酒酵母最佳的EMS质量浓度为40 μg/mL,筛选出1株遗传稳定、可耐3.0%（V/V）异丁醇的优势突变株EMS39。同时在菌株EMS39和W303-1A中过表达L-缬氨酸代谢途径中的关键基因ILV2、ILV5、ILV3和ARO10得到菌株EMS39 23510和W303-1A 23510,将对应的空载体转入菌株W303-1A中得到菌株W303-1A-EP作为对照菌,同时进行发酵性能检测。结果表明,菌株EMS39 23510异丁醇产量达到404.2 mg/L,比对照菌W303-1A-EP提高了529.6%,比菌株W303-1A 23510提高了3.9%,产率比对照菌W303-1A-EP提高了530.0%。其异丁醇及其他发酵产物的产量明显提高,有一定的研究和工业应用价值。     

Multi-channel access technology based on wavelength division multiplexing in wireless UV communication mesh network

In this paper, the multi-channel access technology of wavelength division multiplexing (WDM) in the wireless ultraviolet (UV) scattering communication is studied. A multi-interface and multi-channel device is deployed in each UV transceiver node. The band-pass filter is configured in the receiving node so as to realize the multi-channel access by use of the UV WDM technology. Both the UV communication node model and the UV channel model are established. Three types of UV no-line-of-sight (NLOS) multi-channel communications are simulated in the mesh topologies with NS2. The results show that the UV multi-channel access technology can increase network throughput effectively with using WDM.     

扩建道路的路线设计探析

随着我国道路网的水平逐渐提高,其道路建设也得到了一定的发展,就目前的情况来看,扩建道路的路线设计在道路工程中占着重要的地位。本文通过对扩建道路的路线设计进行了研究,得出了相关的结论。     

酿酒酵母TOR信号通路研究进展

TOR信号通路是酿酒酵母非常重要的保守信号通路,它连接着细胞所能得到的营养信号与细胞生长过程.它可以通过调节翻译、转录、核糖体生物合成、营养物质的运转以及与营养条件相关的自溶来调控细胞的生长.本文综述了酿酒酵母TOR信号通路的主要作用元件,并介绍了其与酿酒酵母时序寿命和Ras/cAMP/PKA信号通路的关系.     

2-乙基蒽醌加氢催化剂的研究进展

高活性和高选择性的催化剂是解决蒽醌法生产过氧化氢过程中瓶颈问题的根本途径。综述了近年来高活性和高选择性镍、钯、铂系催化剂制备的进展。指出负载型镍系非晶态合金和钯系高分子催化剂应是今后蒽醌加氢催化剂研究的方向。     

通过抑制酿酒酵母乙醇发酵中的甘油产率提高乙醇产率

In ethanol fermentation of Saccharomyces cerevisiae （S. cerevisiae）, glycerol is one of the main by-products. The purpose of this investigation was to increase ethanol yield through minimizing glycerol yield by using mutants in which FPS1 encoding a channel protein that mediates glycerol export and GPD2 encoding one of glycerol-3-phosphate dehydrogenase were knocked-out using one-step gene replacement. GLT1 and GLN1 that encode glutamate synthase and glutamine synth.etase, respectively,were overexpressed using two-step gene replacment in fpsl△gpd2△ mutant.The fermentation properties of ZAL69（fpsl△：：LEU2 gpd2△：：URA3） and ZAL808 （fps1△：：LEU2 gpd2△：：URA3 PPGK1-GLT1 PPGK1-GLN1） under microaerobic conditions were investigated and compared with those of wild type（DC124）. Consumption of glucose, yield of ethanol, yield of glycerol, acetic acid, and pyruvic acid were monitored. Compared with wild type, the ethanol yield of ZAL69 and ZAL808 were improved by. 13.17% and 6.66 %, respectively, whereas glycerol yield decreased by 37.4 % and 41.7 %. Meanwhile, acetic acia yield and pyruvic acid yield aecreasea aramatlcally comparea to wild type. Our results indicate that FPS1 and GPD2 deletion of S. cerevisiae resulted in reduced glycerol yield and increased ethanol yield, but simultaneous overexpression of GLT1 and GLN1 infps1△gpd2△ mutant did not have a higher ethanol yield thanfps1△gpd2△ mutant.