万古霉素高产菌株选育及发酵配方优化

为了提高东方拟无枝酸菌产万古霉素的发酵单位,降低生产成本,采用紫外诱变、常压室温等离子体诱变对东方拟无枝酸菌出发菌株V19-02进行诱变处理,通过筛选链霉素抗性突变菌株,选育高产菌株;通过对发酵培养基中碳源和氮源进行筛选,选取葡萄糖、淀粉、低温豆粉、酵母粉4个因素进行均匀设计。结果表明,获得的高产菌株V19-1-07摇瓶发酵单位提高33.7%,且具有良好的传代稳定性;优化后的培养基配比质量分数为葡萄糖8.0%、淀粉1.0%、低温豆粉1.0%、酵母粉4.0%、氯化钠1.0%、磷酸二氢钾0.1%;小试结果证明,优化配方可使50 L罐发酵单位平均达到14 110 μg/mL,比原始配方提高了28.9%。因此,研究获得的高产菌株V19-1-07可应用于万古霉素工业化发酵生产,以帮助企业降低成本,进一步提高竞争力。     

克拉维酸高产菌的选育

以带小棒链霉菌bs1574为出发菌株,经γ射线照射,并结合甘油耐受性菌株的理性筛选,选育得到较佳诱变菌株bs2325,效价达2 569μg/mL.采用摇瓶发酵初筛和复筛,选育出甘油耐受性正向突变菌株,是出发菌株(效价为968 μg/mL)的2.65倍,该突变菌株在琼脂斜面培养基上连续转接传代4代,克拉维酸的产量保持稳定...     

脉冲强光技术选育林可霉素高产菌株

文章采用脉冲强光技术诱变处理林肯链霉菌,筛选出性状优良的菌株,并初步分析其诱变机理,探究脉冲强光诱变林肯链霉菌的可行性,结合链霉素抗性筛选的方法选育林可霉素高产菌株。     

番茄红素发酵培养基及发酵过程控制的研究

为提高番茄红素的发酵水平,筛选了最优的发酵培养基配方,在发酵过程中补加其所需的营养物质,得到一个稳定的配方,并对发酵过程补料进行了优化,番茄红素发酵水平达到2.4 g/L,比较稳定。     

一种化学诱变方法对黑曲霉发酵的影响

经过不同浓度的抗霉素平板对菌株进行化学诱变,通过透明圈、摇瓶筛选,获得高产柠檬酸菌株。经过稳定性试验,最终确定一株稳定性好的高产菌株。     

三孢布拉霉的菌落形态与番茄红素发酵生产能力的关系

为提高番茄红素生产能力,进行了大量的平板单菌落分离,分析了各种形态的单菌落摇瓶发酵的各项指标,找出了生产能力较优的菌落形态,番茄红素发酵水平平均达到1.9 g/L,比较稳定。     

法夫酵母高产虾青素发酵工艺的建立

为建立与虾青素高产菌株相适应的发酵工艺,研究运用正交试验设计优化了发酵培养基配方成份,并在补料摇瓶上确定了碳源补加工艺,且进一步地在70 L发酵罐上对获得的新工艺进行验证。结果表明,影响法夫酵母(Phaffia rhodozyma)虾青素生产的因素,按照主次顺序及影响由大到小排列为碳源>酵母抽提物>乳酸>(NH_(4))_(2)SO_(4)>蛋白胨>KH_(2)PO_(4)>微量元素。该研究建立了法夫酵母高产虾青素的生产工艺,为虾青素的商业化生产提供了坚实的基础。     

泰乐菌素发酵补料工艺优化研究

文章通过优化泰乐菌素发酵补料工艺条件，研究补料次数及补料时间对泰乐菌素发酵效价的影响，探讨泰乐菌素发酵的最佳补料工艺。结果表明：两次补料对泰乐菌素发酵效价提升效率更高，且两次补料的最优时间在发酵48 h和96 h，发酵效价从13 987μg/mL提高至14 500μg/mL，较单次补料发酵效价提高了3.67%。     

溶磷和pH值对杀真菌素链霉菌合成恩拉霉素的影响

研究了培养基灭菌后溶磷和发酵过程pH值等对杀真菌素链霉茵(Streptomyces fungicidicus)JZ-14-056D3合成恩拉霉素的影响,通过发酵尾气成分的测量和OUR,DO等参数的分析,发现培养基灭茵后溶磷质量浓度控制在0.65μg/mL,控制发酵过程pH值为7.0,192 h发酵单位最高可达5 710...     

重组大肠杆菌产耐高温β-糖苷酶发酵条件优化

β-糖苷酶ttβGLY是Thermus thermophilus产生的一种耐高温酶,该酶具有较高的乳糖水解活性和转糖基活性。通过对重组大肠杆菌发酵生产β-糖苷酶ttβGLY条件的研究发现,优化后的培养基组成如下:蛋白胨14g/L,酵母粉7g/L,乳清13.3g/L,NaCl 10g/L,KH2PO43g/L,K2HPO45g/L,MgSO4.7H2O 1g/L。种子培养基组成如下:蛋白胨10g/L,酵母粉5g/L,葡萄糖4g/L,NaCl 10g/L,CaCO35g/L。种龄12h,接种量8%,装量40mL/250mL三角瓶,于37℃发酵24h,菌体干重10.010g/L,酶活可达2.384U/mL,分别是优化前的4.4倍和2.4倍。     

Divergent patterns of engagement in Internet standardization: Japan,Korea and China

This article analyzes the engagement of Japanese, Korean and Chinese participants in the development of Internet standards at IETF on the basis of four quantitative metrics: attendance, patenting, authorship and leadership. The results are strikingly divergent. Japanese involvement in Internet standardization began early and Japan was, for many years, second only to the U.S. in terms of IETF participation. Though Japanese participation has declined since the early 2000s, Japan remains a major contributor to IETF standardization. Korean involvement in IETF has always been significant, but below the levels of Japan and major European countries. Korean participation in IETF has also declined over the past decade, and has been dominated by one firm, Samsung. Though meaningful Chinese involvement in IETF did not begin until the mid-2000s, it has rapidly expanded in recent years. Today, China is a major player in numerous areas of Internet standardization in terms of three metrics (participation, patenting and leadership), and is rapidly gaining in terms of document authorship as well. Most of China׳s recent IETF involvement can be attributed to Huawei, though other Chinese firms have recently begun to increase their participation in the organization. Thus, contrary to some views that China׳s engagement with standardization is primarily one of indigenous innovation and “catching up”, China׳s experience with IETF demonstrates deliberate and effective engagement with a major Western standards-development organization on its own terms.     

Whose Image is it Anyway?: Some Considerations of the Curricular Importance of Subject Image in Secondary School Design and Technology Education

This paper explores the idea that a sense of school subject image is a necessary feature of curriculum management and a potent force for change. The discussion centres on the view that all school subjects have an image and that if those intimately involved with the subject do not control the image then someone else does! In such circumstances the image is the product of past encounters and old euphemisms and is unlikely to hold the changed realities.The UK developments in Design and Technology education (the term Design and Technology is used to denote the school subject defined under this heading by the UK National Curriculum, 1995) have created something of an image problem which has interesting international parallels. Some of these problems are due to clearly discernible internal tensions and an ambiguous relationship with other subject areas.Through greater attention to subject image internal controversies might be acknowledged and resolved, relationships with other subject areas can be more meaningfully understood and practitioners can be helped to make sense of curriculum change.     

蒸汽热量计量应用的探析

研究了石油化工企业的燕汽计量情况,着重对蒸汽热量计量的合理性进行了分析,阐述了蒸汽热量计量的依据及计算方法,以及蒸气热量计量对节能降耗的重要意义.     

论传统旗袍文化与现代时装

中国的旗袍文化蕴含着非常丰富的文化内涵和设计思想,如今旗袍的普及受到一定的限制,只有经过改良,才可变局限性为可行性,才可使旗袍焕发青春,走向新时代。     

望峰岗矿井贯通测量技术分析

在深部开采矿井两井间贯通测量时,利用加测陀螺定向边和用四架法代替传统的三架法测量,分析了由起始边的方位角误差引起的支导线终点误差及由测角量边引起的导线终点的点位误差.     

工程施工质量控制和管理要点

提高施工中质量管理工作水平，为公司今后发展打下良好基础。     

高油价影响我国经济

从2004年初以来，国际油价急剧攀升，文章分析了原油价格居高不下的原因，对未来油价的走势及其对我国经济的影响和冲击进行了预测，面对这种情况我国必须采取应对措施：树立节能消费理念；促进技术创新，推动产业升级；建立石油战略储备、推出原油期货、推动多元化战略等。     

亲油性纤维材料性能及应用

纤维素纤维是自然界广泛分布的天然纤维,像法桐球果纤维、木棉纤维、杨花纤维、蒲公英绒纤维,都是纤维素纤维,纤维具有吸油快、吸油量大、拒水的性能特点,纤维不易进行纺织生产加工,但可以作为海面吸油材料使用,并且加工方法简单,吸油效果好。     

Optimizing receiver performance using harm claim thresholds

More and more systems need to be squeezed together in frequency, space and time in order to satisfy the growth in demand for radio services. However, greater proximity increases the risk of service breakdowns caused both by poor interference tolerance in receivers and by inappropriate signals radiated by transmitters.     

Broadband expectations and the convergence of ranks

Broadband Internet service to widely held to be a significant contributor to economic development and global competitiveness, and comparison of adoption rates across countries are common. This paper presents evidence that the relative broadband Internet adoption ranks across the Organisation for Economic Co-Operation and Development (“OECD”) countries are converging to the wireline telephone adoption ranks in the mid 1990s. This was a time when wireline telephone service had reached maturity, but before consumers began to abandon traditional telephone services for mobile services and Internet telephone technologies. As such, in the absence of better data on household adoption, wireline telephone rank is a useful proxy for a country's ultimate fixed-line broadband penetration rank. Having such an educated guess available regarding broadband rank should reduce the amount of anxiety over rankings, since similar rankings across the two services implies suitable broadband performance. Large departures, alternately, may be a cause for concern or delight. Like prior analyses, the findings suggest that the adoption of communications services is largely an economic and demographic issue.