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1.
根霉L-乳酸发酵的研究   总被引:2,自引:0,他引:2  
研究了东京根霉(Rhizopus tokinensis) R8-1产生L-乳酸的发酵条件。比较了不同碳源和不同含量碳源对产酸的影响,以10%的葡萄糖、30℃下210r/min振荡培养72h,得到的发酵液中乳酸的质量分数为7.5%,对糖的转化率为80.64%:以12%的玉米粉为碳源发酵60h,发酵液中乳酸的质量分数为7.18%,对糖的转化率为78.4%。静置培养时乳酸产量要比通气培养时低得多。发酵产物经旋光分光仪、红外光谱与核磁共振谱测定可确认为L-乳酸,为同型乳酸发酵。  相似文献   

2.
利用热带假丝酵母(Candiatropicalis)、绿色木霉(Trichodrmalignorum),白地霉(GrieotrichumcandidumLink)、黑曲霉(AspergillusNiger)、米曲霉(Aspegillusoryzal)等五株菌混合发酵啤酒糟生产饲料蛋白,提高饲料的利用价值,并改善了啤酒糟的适口性。通过五种菌株的协同作用使啤酒糟中的非氮物质转化为蛋白质,没被利用的多糖物质和如纤维素,半纤维素及部分淀粉转化为被消化吸收的低聚糖、双糖和单糖。在同一条件下,同一时间内各种菌株相互间协调,各自完成发酵的功能。培养基为啤酒糟85%、玉米面10%、麦麸5%。培养温度28-30℃,培养周期48h。分析结果表明:粗蛋白含量高达32.86%以上,氨基酸齐备,粗纤维降低到9.9%,具有较高的蛋白酶,果  相似文献   

3.
利用热带假丝酵母提高酶解马铃薯汁的蛋白质含量   总被引:1,自引:0,他引:1  
马铃薯汁用糖化酶水解,接种热带假丝酵母,在摇床中30℃,120r/min培养3d.分别用(NH4)2SO4或柠檬酸铵为氮源,用Na2HPO4-KH2PO4缓冲液和CaCO3为pH值稳定物质时,测定发酵基质中蛋白质的增加量.结果表明,以(NH4)2SO4为氮源,用Na2HPO4-KH2PO4缓冲液(0.02mol/L,pH6.8)和CaCO3(0.3%)为pH稳定物质时,发酵基质中蛋白质含量的增加值最大,以干重计,蛋白质含量从10.4%增加到39.6%.  相似文献   

4.
通过对茁芽短梗霉As3.2756四次紫外诱变,获得了一株高产普鲁兰的变异株PB518,使糖的转化率达55%以上,经多次传代表明该菌株稳定。同时考察了该变异株的发酵条件,最适条件为起始pH6.0,接种量3.0×10 ̄8个/mL通气量为培养基占摇瓶体积的1/10,发酵温度28℃,发酵时间96h。  相似文献   

5.
耐低温木霉TR-165固态发酵条件的研究   总被引:7,自引:0,他引:7  
目的 为使木霉代替农药,对土壤中分离筛选的低温木霉TR-165固态发酵条件进行研究。方法采用单因素实验。结果在含麸皮、苹果渣及无机盐的固料中,于pH7.0,含水量20%,接种量8%(孢子液/固料),初始2d为24℃,第3—5d为20℃,第6d为26℃,固料厚度2cm,每4-5h搅拌并喷水1次,发酵7—9d,孢子密度可达10^10mg^-1以上。结论以麸皮、苹果渣及无机盐为固料发酵生产低温木霉是一种快速、高效和实用的方法。  相似文献   

6.
糖化酶在黄酒酿造中的应用探讨   总被引:1,自引:0,他引:1  
本文主要以正交试验法对糖化酶在黄酒酿造中的影响因素进行了综合定量研究,并对成品酒进行了理化分析和综合评价。研究结果表明,糖化酶作用的最佳条件为:加酶量0.02%;加酶时间为投料48小时后;酶作用的最适温度为32℃,酶作用的最适PH值为PH=4.6。在此条件下,主发酵期缩短2-3天,后发酵期缩短10-60天,同时,出酒率有明显提高,高达92.07%,是传统的3.1-4.6倍。  相似文献   

7.
果渣固体发酵生产黄腐酸   总被引:2,自引:0,他引:2  
目的由苹果渣发酵制取黄腐酸。方法采用正交实验,连续二次固体发酵工艺。结果发酵的最佳物料比为果渣:豆饼:麸皮=50:4:3(质量比),含水量为20%(质量分数);发酵最佳工艺为先接绿色木霉和康氏木霉各2.5%(孢子液/固料,质量分数),28℃,发酵12d,灭菌;再接假丝酵母、酿造酵母、枯草杆菌和棒杆菌各2.5%(孢子液/固料,质量分数),32℃,发酵12d,黄腐酸得率为42.2%。结论苹果渣固体发酵制取黄腐酸是一条可行、经济和快速的途径。  相似文献   

8.
用稀土氧化物渣处理铁水,在1450℃下处理20min,即可冶炼出稀土含量在0.01%~0.041%范围内、碳当量CE在3.83%~4.93%范围内的球墨铸铁。脱硫反应、稀土氧化物还原反应热力学条件具备,只要搅拌条件良好,都可获得成功。而铁水磷含量应当降低,以确保铸件力学性能  相似文献   

9.
花生四烯酸产生菌的原生质体诱变育种   总被引:6,自引:0,他引:6  
采用化学诱变剂硫酸二乙酯(DES)对由高山被孢霉出发菌株M3-18制备的原生质体进行诱变育种,实验结果表明,采用体积分数为10%的DES诱变3min,可获得高产突变株M20,其花生四烯酸产量比对照株M3-18提高了4.4倍,而且突变株的继代遗传稳定。说明采用原生质体诱变育种是获得花生四烯酸高产菌株的有效方法。  相似文献   

10.
黑曲霉发酵玉米淀粉生产柠檬酸   总被引:7,自引:0,他引:7  
用紫外线和亚硝基胍诱变相结合的方法,从野生黑曲霉菌株出发,经多次诱变筛选,得到一株能够较好地利用玉米淀粉生产柠檬酸的黑曲霉菌株A.niger95。对A.niger95在摇瓶和发酵罐上用玉米淀粉发酵产生柠檬酸的适宜条件作了详细研究。经过比较,认为摇瓶产生柠檬酸的适宜培养基配方及发酵条件为:玉米淀粉20%(均为质量分数,下同)、(NH4)SO40.2%、KH2PO40.2%、MgSO47H2O0.05%,甲醇3%,初始pH3.0。接种液体种子5%,30℃200r/min发酵7d,柠檬酸产量10.8%。在6.6L的Bioflo-Ⅱ型发酵罐上设定30℃,500~600r/min,pH4.0,1.2~2.5L/min的通气量,发酵132h,柠檬酸产量为9.3%。可用价格低廉、来源丰富的玉米淀粉代替传统的薯干,作为发酵生产柠檬酸的原料,为实际生产奠定了基础。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

19.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

20.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

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