一种提高新霉素产素率新方法的初步研究

新霉素(Neomycin)是弗氏链霉菌(Streptomyces fradiae)产生的氨基糖苷类抗生素,口服给药体内难以吸收,在肠道中保持较高浓度,适用于治疗胃肠道和呼吸道感染,被广泛应用于畜牧业。几十年来国内外沿用一种发酵生产工艺,过程复杂,周期长,产率低,成本高。一种生产新霉素的新方法问世,即不改变原菌种遗传性状(DNA),除去摇瓶发酵原培养基中玉米浆,花生饼粉,玉米淀粉,添加促进剂甘氨酸,赖氨酸,酪氨酸,蛋氨酸,同时培养基调pH,36℃培养。摇瓶发酵周期由136h缩短到96h,产素率(u.h-1.ml-1=u/h.ml,单位时间、单位体积产抗生素的量)提高40%以上,简化了生产工艺,降低了生产成本,增加了产量,同时为扩大到发酵罐实验及工业生产奠定了基础。

几种氨基酸在庆大霉素生产中的作用

庆大霉素国内外生产发酵周期长,产素率低,成本高,缺乏竞争力。报道了在绛红色小单孢菌(Micromonospora purpurea)产生庆大霉素的培养过程中,添加一定量的甘氨酸、蛋氨酸、赖氨酸、酪氨酸能够有效地提高微生物细胞的代谢能力,缩短发酵培养周期,提高产素率。在小试(摇瓶)成功基础上,用5L玻璃发酵罐运转一个多月,取一个月的平均罐批数据表明:新方法较原工艺发酵周期缩短30%～45%,罐批产量增加14%左右,产素率提高30%～95%(因菌种生产能力不同而异),产品质量符合中国药典2000版(CP2000)、英国药典2000版(BP2000)、美国药典26版(USP26),生产成本大幅度降低,具有很强的市场竞争力。

增加新霉素产量的研究

报道了一种生产新霉素的新工艺.该工艺除去摇瓶发酵原培养基中的玉米浆、花生饼粉及玉米淀粉,添加促进剂甘氨酸、赖氨酸、酪氨酸、蛋氨酸,不改变原菌种遗传性状(DNA)36℃培养.摇瓶发酵周期由136 h缩短到112h,产素率(单位时间、单位体积产抗生素的量)提高30%以上,简化了生产工艺,降低了生产成本.

庆大霉素产生菌的基因工程育种

研究小单孢菌产抗生素的生物合成机理,利用基因克隆方法从棘孢小单孢菌(Micromonospora echinospora)中克隆出产庆大霉素生物合成的关键酶基因—2-脱氧青蟹肌糖合成酶基因(gntB),并将其通过大肠杆菌——链霉菌穿梭质粒pIJ699转化原菌株,采用硫链丝菌素抗性基因启动子带动2-脱氧青蟹肌糖合成酶基因表达,在培养条件不变的情况下重组菌产抗率较原菌株提高3.5%。

初探内疗素单菌落形态发育与产素

初探内疗素单菌落形态发育与产素潘钧陶，李东海（辽宁省微生物研究所，朝阳１２２０００）当琼脂平板上隐约可见菌落时，采用琼脂块法打取单个菌落，标记时间，置温箱培养，定时观察其形态发育特征，并测其生物效价。现将琼脂平板上，内疗素单菌落形态发育六个时期简介于...

甘氨酸、赖氨酸、酪氨酸、蛋氨酸在棘孢小单孢菌中的作用

在棘孢小单孢菌(Micromonospora echinospora)突变株(Fzu-707)产生小诺霉素的过程中,运用正交设计筛选小诺霉素(Micronomicin,MCR)生物合成促进剂——氨基酸.经摇瓶实验证明在原培养基中添加一定量的甘氨酸、赖氨酸、酪氨酸、蛋氨酸有利于生物合成小诺霉素,在旋转摇床上220 r/min 36℃培养,发酵时间由原工艺144 h缩短到104 h,产量(u.mL-1)较对照可增加20%左右,产素率(u.mL-1.h-1))提高60%左右.

Supply-Side Structural Reforms and China's Potential Economic Growth Rate

This paper examines the effect of supply-side structural reforms on China＇s potential economic growth rate in the coming decade according to the data the authors have gathered. Under the rapid growth scenario with the implementation of supply-side structural reforms, China＇s potential economic growth rate will reach an average of 6.5% and 5.8% respectively in the 13th Five-year Plan （2016-2020） and 14th Five-year Plan （2021-2025） periods. These rates are 0.2 and 0.3 percentage points higher, respectively, than that under the baseline scenario with the inertia of historic trends. In implementing supply-side structural reforms, China must transform governmental functions, break monopolies, create a comprehensive competitive market environment, foster the creation of pro-innovation mechanisms, refocus on quality and efficiency, and raise capital utilization and labor productivity.

Effect of N Fertilization on Yield, N Absorption and Utilization of Two Species of Super High-Yielding Summer Maize

[Objective] The aim was to study on effects of N fertilizer on yield, N absorption and utilization of different cultivars of super high-yielding summer maize, in order to provide reference for reasonable N fertilization in accordance with different cultivars. [Method] Field experiment was conducted to study on effects of different N fertilizers on yield, N absorption and use efficiency of Zhengdan 958 and Xundan 20, in order to learn the effect differences at different N fertilizer levels. [Result] After N was applied, yields of the two summer maize increased significantly. Zhengdan 958 achieved the highest in yield and proceeds at 12 051.18 kg/hm2 and 1 722.40 yuan/hm2, respectively in low N level. In contrast, Xundan 20 achieved the highest at 13 166.00 kg/hm2 and 1 343.92 yuan/hm2 in the above two aspects in high N level. Compared with Zhengdan 958, Xundan 20 increased by 9.90%, 5.20% and 12.00% in N levels of 0, 240, and 450 kg/hm2, respectively. When N fertilizers were applied, protein yield of Xundan 20 was significantly higher than that of Zhengdan 958, so that higher N fertilizers contributed higher protein yield for Xundan 20. In high N level, N efficiency, N-fertilizer utilization and partial productivity of Xundan 20 were significantly higher than that of Zhengdan 958. [Conclusion] Lower N-fertilizer was suitable for Zhengdan 958 and Xundan 20 would get a good harvest if more N-fertilizers were applied. The results provided references for reasonable N fertilization.

Heterosis Analysis of Nitrogen Use Efficiency for Grain Production of Brassica napus L.

[Objective]The aim was to study heterosis of N use efficiency for grain production （NUEg） of Brassica napus L. and provide theoretical basis for breeding N-efficient cultivars. [Method]Dry matter production and N content of six B.napus parents （Zheshuang 3,Yangyou 7,ZJ1,Shilijia,Ningyou 14 and Huyou 16） and their F1 combinations from 6 × 6 complete diallel cross in maturity stage under two N levels were measured; heterosis of NUEg,combining ability and heritability size were analyzed and calculated. [Result]The results showed that NUEg has obvious heterosis; combining ability variance analysis indicated that NUEg was mainly controlled by additive,dominant and cytoplasmic effects; genetic variance analysis showed that additive effects and dominance effects were all significant in low nitrogen fertilizer and dominance effects were significant in high nitrogen fertilizer. [Conclusion]NUEg of B.napus has obvious heterosis.

Effects of SPAD Decline Value of Mid-season Hybrid Rice Leaves after Full-heading Stage on Productivity of Rice Fertilized with Nitrogen

[Objective] The aim was to research relationship between SPAD decline index after full-heading stage （SDIFHS） and productivity of rice. fertilized with nitro- gen in order to provide theoretical and practical references for selection and breed- ing of rice varieties. [Method] From 2008 to 2010, 18 mid-season hybrid rice vari- eties were researched every year to explore relationship＇ between SDIFHS and pro- ductivity of rice fertilized with nitrogen. [Result] The productivity of rice fertilized with nitrogen was of extremely significant positive corretation with SDIFHS, because the higher SPAD decline index is, the higher LAI decline index and the transformation ratio of dry matter to spikes in overground plant would be. [Conclusion] The re- search established a new method to predict productivity of rice fertilized with nitro- gen based on SPAD decline index.

Advances in Research on Water and Fertilizer Coupling and Its Effects on Rice Growth and Utilization Rate of Nitrogen

At present, the shortage of agricuItural water resources is worsening. In order to reduce the rice irrigation water and improve the utiIization of fertiIizers so as to achieve the high and stabIe yielding of rice, this report reviewed the research advances in water and fertiIizer coupIing, the conception of water and fertiIizer cou-pIing and its three kinds of effects （synergy, antagonism, superposition）, mechanism of water and fertiIizer coupIing, effects of water and fertiIizer coupIing on growth, deveIopment, yield and quality of rice and effects of water and fertiIizer coupIing on utiIization rate of nitrogen in rice. In addition, the deveIopment prospects of water and fertiIizer coupIing in China were described. It was proposed that the water and fertiIizer coupIing mode is an effective measure to achieve the high yield and quality of rice. According to actual demand, referring to the ideas of promoting fertiIizer with water and reguIating water with fertiIizer, reasonabIe water and fertiIizer cou-pIing mode can be estabIished, thereby improving the utiIization efficiencies of water and fertiIizer. In the premise of saving irrigation water and no increasing fertiIization amount, both high yielding and Iess poI ution can be achieved, providing theoretical and technical basis for water-saving agricuIture and cuItivation and management of rice in future.

Advances in Application of Biological Nitrification Inhibitors

Based on current research, the characteristics and action mechanism of biological nitrification inhibitors at home and abroad were reviewed by combining with the latest research progress. The application effects of biological nitrification inhibitors on agricultural production were summarized. Research hotspot and achievements of biological nitrification inhibitors at home and abroad were summarized. The research direction in future was forecasted.

Environmental Regulation,Pollution Treatment Productivity,and Industrial Environmental TFP in China

Amidst growing environmental protection intensity by the Chinese government, this paper investigates the effects of environmental regulation on China＇s industrial pollution treatment productivity and environmental TFP. By estimating China＇s pollution treatment productivity between 2001 and 2008 and analyzing environmental regulation intensity and the effects of the relevant factors and pollution treatment productivity using panel data, this paper discovers that （1） pollution treatment productivity contributed a significant share of about 40% to industrial environmental TFP during the investigation period; （2） environmental regulation may not necessarily cause adverse impacts on pollution treatment efficiency and productivity but demonstrates a U-shaped relationship： when the share of pollution treatment cost in industrial value-added is above the range of 3.8%-5.1%, environmental regulation is likely to promote pollution treatment productivity and thus environmental TFP Judging by the estimation result, enhancing environmental protection and expediting the development of ecological civilization are conducive to China ＂s economic transition towards an intensive, efficient, circular, and sustainable development pattern. China＇s current industrial development has the capacity to tolerate a rather demanding level of pollution treatment and management and China needs to further rely on energy conservation and the environmental production industries to promote the progress of pollution treatment technologies.

Release Characteristics of Release-controlled Nitrogen Fertilizer in Winter Wheat on Dry Land

[Objective] The aim was to study the release characteristics of different release-controlled fertilizers, as well as their effects on wheat growth and develop- ment under water stress. [method] With phosphorus-potassium fertilization and opti- mized fertilization （OPT） as the control, the release characteristics of 4 kinds of re- lease-controlled nitrogen fertilizers （A, B, C and D） coated with different materials were studied. [Result] Under the same phosphorus and potassium levels, the re- lease-controlled nitrogen fertilizers A and B significantly improved the yield of wheat. Spike number is the main reason leading to the difference in yield. The fertilizers A and B were released by 44.4% and 46.3% before winter, released by 72.1% and 69.8% at the jointing stage, and related by 88.0% and 91.5% in the harvest period, meeting the nitrogen requirement of dryland wheat across the growth period. Com- pared with OPT, the nitrogen accumulation amounts in treatments A and B were increased by 1.39 and 2.09 kg/667 m2, the nitrogen use efficiencies were increased by 8.66% and 13.04%, and the nitrogen partial factor productivities were increased by 9.00 and 7.22 kg/kg, respectively. [Conclusion] Among the 4 kinds of fertilizers, A and B were considered as the optimum release-controlled nitrogen fertilizers for winter wheat on dry land.

Comparions of Required Nitrogen Fertilizers by Hybrid Cultivar and Conventional Cultivar of Rapeseed(Brassica napus L.)

[Objective] The aim of this study was to understand the difference of N fertilizer requirement between hybrid rapeseed and conventional rapeseed. [Method] Two hybrid cultivars, ZY5628 and ZY7819, and the conventional cultivar ZS10, were compared through two field experiments. In Experiment 1, seed yield and optimum N application rate were assessed in the field with five N application treatments. In Expedment 2, N was applied uniformly at 180 kg/hm2, and plant biomass and N accumulation were measured at several developmental stages, while N use efficien- cy was calculated for rape at maturity. [Results] The experiment 1 results showed that seed yields of ZY5628 and ZY7819 were both significantly higher than that of ZS10, and compared to ZS10, optimum yield （plateau yield） was higher by 18.7% and 20.2%, while the recommended N application rate was lower by 9.5% and 9.6% for ZY5628 and ZY7819, respectively. The experiment 2 results showed that during vegetative development, all three cultivars exhibited similar accumulations of plant biomass and N, but through flowering and maturity ZY5628 and ZY7819 pro- duced more biomass, acquired more N, and utilized acquired N more efficiently to- wards seed production than ZS10. [Conclusion] With equivalent inputs, the hybrid rapeseed cultivars ZY5628 and ZY7819 tested herein yield more seed with higher N use efficiency than the conventional rapeseed ZS10. This information will be valu- able for growers seeking to improve efficiency while reducing costs of rape production in China.

Creative Industries Agglomeration,Regional Innovation and Productivity Growth in China

This paper falls into the broad area of economic geography and economics of creativity,and it presents an alternative approach to explain why total factor productivity(TFP)growth is different across China′s regions.It establishes an empirical model to estimate the spatial agglomeration effects of creative industries on regional TFP growth,using China′s provincial panel data during the period of 2003 to 2010.We found that the creative industries agglomeration(CIA)has significant and positive impact on regional TFP growth.The result also implies that the CIA can facilitate regional TFP growth through promoting regional innovation instead of improving regional efficiency.Therefore,we argue that policy makers should take some measures to retain and establish more creative zones.

The Contribution of Marketization to China＇s Economic Growth

Market-oriented economic transition since 1978 has led to remarkable economic development in China. In this study, we use the National Economic Research Institute （NERI） Index of Marketization and a panel data model to investigate the quantitative contributions of marketization to China＇s total factor productivity （TFP） and economic growth. Our results indicate that marketization contributed 1.45 percentage points on average to China＇s annual economic growth rate during the period from 1997 to 2007 and accounted for 39.2 percent of the increase in TFP. Marketization significantly improved resource allocation. However, economic transition in China has not yet been completed and sustainability of future growth will depend on further market-oriented reforms.

Industrial Green Spatial Pattern Evolution of Yangtze River Economic Belt in China

We use the directional slacks-based measure of efficiency and inverse distance weighting method to analyze the spatial pattern evolution of the industrial green total factor productivity of 108 cities in the Yangtze River Economic Belt in 2003–2013.Results show that both the subprime mortgage crisis and ‘the new normal' had significant negative effects on productivity growth,leading to the different spatial patterns between 2003–2008 and 2009–2013.Before 2008,green poles had gathered around some capital cities and formed a tripartite pattern,which was a typical core-periphery pattern.Due to a combination of the polarization and the diffusion effects,capital cities became the growth poles and ‘core' regions,while surrounding areas became the ‘periphery'.This was mainly caused by the innate advantage of capital cities and ‘the rise of central China' strategy.After 2008,the tripartite pattern changed to a multi-poles pattern where green poles continuously and densely spread in the midstream and downstream areas.This is due to the regional difference in the leading effect of green poles.The leading effect of green poles in midstream and downstream areas has changed from polarization to diffusion,while the polarization effect still leads in the upstream area.

Spatial-temporal Evolution Pattern of Agricultural Productivity in Northwestern Sichuan Plateau

Currently, the agricultural growth in developed countries mainly relies on the improvement of productivity, which is also the target for China. Accordingly, the purpose of this study was to describe the spatial-temporal evolution pattern of agricultural productivity, to reveal changes in total factor productivity in 2ooo-2olo, and analyze the impact of these changes in northwestern Sichuan plateau, China. Using data envelopment analysis （DEA） and the Malmquist Index, an in-depth study was conducted on agricultural productivity and changes in total factor productivity of 31 counties in northwestern Sichuan plateau. Results indicated that： （1） geographically, counties with optimal efficiency were mainly located in the north of northwestern Sichuan plateau and those with the lowest efficiency, in the south; （2） relative to pure technical efficiency, scale efficiency was the dominant factor in determining agricultural productivity; （3） the redundancy rate of input factors in zolo was slightly lower than that in zooo, thereby indicating an improved utilization of input factors to a certain extent and a great potential for further improving such utilization; （4） during the 2ooo-2olo period, the agricultural total factor productivity had an average annual growth rate of 8.3%, but the growth rates in various regions differed widely; （5） technical progress was the dominant factor promoting the improvement of total factor oroductivitv inagriculture. The disparities in spatial distribution may be due to the differences of natural conditions, former level agricultural productivity between counties. The findings are valuable for the government to make sustainable development policies for agriculture and improving agricultural development in northwestern Sichuan plateau.

Empirical Research on the Credit Demand and Credit Behavior of Small and Micro Enterprises

This article uses discriminant sampling method to select 1062 small and micro enterprises from 25 provinces in China. Researches were conducted on their credit demand and credit behavior, with the Probit model to carry out metrologic tests on influential factors of these enterprises' credit demand and credit behavior.The metrologic analysis shows: Literacy level of leader, asset size, annual revenue of the enterprises have significantly positive effects on the credit demand of these small and micro enterprises. Annual revenue has significantly negative influence on overall credit behavior and the occurrence of informal financial behavior, but significantly positive influence on the occurrence of formal financial behavior. Literacy level of staff and asset size of enterprises have significantly positive influence on the occurrence of the overall credit behavior of small and micro enterprises.