Vc二步发酵中的微生物生态调控

研究了Vc二步混合菌发酵中氧化葡萄糖酸杆菌与巨大芽孢杆菌的生长和相互作用 .结果表明 ,2株混合菌在发酵中可形成一种协同共生 ,促进 2 酮基 L 古龙酸产生 ;二菌协同共生的过程及条件不同 ,促进产酸能力亦不同 .环境因子影响二菌协同共生 .优化环境因子可显著改善二菌协同共生效率 ,并提高醇酸发酵转化率 .

VC二步发酵种液质量判定

研究了影响种子质量的各个参数与提高种子质量的途径。结果显示 :在苏云金杆菌 (俗称“大菌”)与氧化葡萄糖酸杆菌 (俗称“小菌”)组成一新组合菌系中 ,种液中菌的浓度对发酵影响较大 ,种液中的 (大菌OD值 - 1 6×小菌OD值 )与发酵速度成正相关 ,可作为种子质量的判定指数。同时对种液的配方进行均匀设计实验 ,结果显示 :适当提高玉米浆、葡萄糖等成分与降低尿素的浓度及调高pH值均有利于种液质量的改善

环境因子对新组合菌系产生Vc前体KGA的影响

通过测定氧化葡萄糖酸杆菌产酸变化 ,研究了环境因子对新菌系产酸的影响。结果显示 :新混菌体系产酸温度范围为2 4 - 33℃ ,2 8℃左右为最适 ,适当增加通气量 (2 5 - 35ml装液量 ,30 0ml三角瓶 )有利于掷孢酵母和氧化葡萄酸杆菌协调 ,通气量过大、过小都会破坏二菌比例 ,进而破坏而二菌间协调性 ,不利于 2 -酮基 -L -古龙酸的积累。

混菌状态对新菌系产生VC前体KGA的影响

通过测定氧化葡萄糖酸杆菌产酸变化 ,研究了新菌系混菌状态对产酸的影响。结果显示 :新混菌体系中 ,种液KGA为4 1- 5 5mg ml,混合菌菌群氧化葡萄糖酸杆菌 掷孢酵母为 2 6 - 35 :1,混菌生物量达 0 4 6 - 0 6 0 (OD值 ) ,有利于二菌在发酵中相互协调 ,促进产酸 ,调节接种生物量可增加产酸速度 ,缩短产酸周期 ,但不影响最终产酸量

巨大芽孢杆菌(Bacillusmegaterium)突变株Bn,B5的生物学特性及在Vc二步发酵中的伴生作用

对选出的巨大芽孢杆菌突变株Bn ,B5进行了生物学特性及发酵条件的研究 ,发现它们具耐低 pH和抗高浓 2KGA特性。可促进氧化葡萄糖酸杆菌生长 ,使其延迟期缩短 ,产酸增加。适宜的通气量下 ,摇瓶糖酸转化率提高 10 %～ 14% ;当发酵 pH为 6 .2～ 6 .6时 ,转化率提高 2 0 %～ 30 %

葡萄糖补加对VC二步发酵产古龙酸的影响

研究了葡萄糖的补加对维生素C二步发酵产酸的影响。摇瓶发酵实验结果表明,15%的接种量,接种至底物山梨糖浓度为8%的发酵培养基,发酵24h时,补加0.08%的葡萄糖,可提高发酵转化率5.2%。

一种Vc二步发酵伴生菌的初筛方法

目的:建立一种Vc二步发酵高效伴生菌的快速初筛方法。方法:通过测定OD650,以伴生菌进入对数期的早晚和对数期持续长短为判断菌株伴生潜力的依据。结果:10h前进入对数期,对数期持续时间约12h的菌株具有高效的促进小菌生长和发酵产古龙酸的潜力。概率为71%。结论:以伴生菌进入对数期的早晚和对数期持续长短为判断依据的新的菌株快速初筛方法,简便、高效,利于大规模初筛应用。

以掷孢酵母作为伴生菌产生VC前体KGA的研究

以掷孢酵母作为伴生菌与氧化葡萄糖酸杆菌组成新混菌体系 ,通过测定生长代谢曲线 ,对其产酸性能和特点进行了研究。结果显示 :相同条件下 ,新菌系产酸能力高于现有菌系 ,酸量增加 5 - 7mg/ml,发酵周期缩短 6 - 8h,酸转化率提高 3- 4 % ,最高产酸点pH值下降约 0 5个单位 ,表现出较大的产酸潜力和可修饰性。

应用Vc发酵弃渣防治保护地病害

The prevention and control of tomato plant diseases were conducted in protective ground using Vc fermentation waste residue treated by enzymolysis and ultrasonic wave. The results showed that the seedlings planted for 3 weeks on the protective ground soil continuously cropped tomato plant for 9 years and fertilized 75, 150 and 300 kg·hm -2 grew well. Their biomass were increased by 123%, 164% and 182%, and the disease incidence rates were decreased by 59%, 78% and 85%, respectively. Under application of 300 kg·hm -2 Vc fermentation waste residue, the products of tomato grown for 10 weeks on the soil continuously cropped tomato plant for 9, 6 and 2 years were increased by 60%, 43% and 14%, respectively, and the disease incidence rates were all decreased by 50%.

Study of alpha-, beta- and gamma-cyclodextrin/C-60 supramolecular complexes: Influence of the cavity dimension toward the host-guest complexes

Herein we report the spectroscopic, electrochemical, TEM and DLS characterizations Of C-60 supramolecular inclusion complexes with alpha-, beta- and gamma-cyclodextrins prepared using anionic C-60. The results indicate that the cyclodextrin itself has little effect on the encapsulated C-60 or on the properties of the inclusion complex. Instead, the cyclodextrin has a significant influence on the aggregation behavior of individual complex in aqueous solution, which in turn affects the property of the supramolecular complex of cyclodextrin and C-60 greatly, As the cavity dimension of cyclodextrin becomes smaller as it changes from gamma-CD to beta-CD, and finally to alpha-CD, it is observed that more aggregation occurs for the corresponding inclusion complex in aqueous solution.

A new flow field and its two-dimension model for polymer electrolyte membrane fuel cells (PEMFCs)

A new flow field was designed to search flow fields fitting polymer electrolyte membrane fuel cells (PEMFCs) better due its extensible. There are many independent inlets and outlets in the new flow field. The new flow field we named NINO can extend to be more general when pressures at the inlet and outlet vary and some usual flow fields will be obtained. A new mathematical model whose view angle is obverse is used to describe the flow field.

在VC环境下用Direct3 DIM Framework开发三维动画

介绍了DirectX的基本概念及Direct3DIMFramework的基本程序结构 ,通过一个例子程序 ,详细叙述了如何在VC + +环境下用DirectX中的Direct3DIMFramework编写三维动画程序

Ethical Dimension of Time in Plato’s Apology of Socrates

The aim of the present article is to analyse the Apology in its aspect of time. When defending himself against the charges, Socrates appeals to the past, the present and the future. Furthermore, the philosopher stresses the meaning of the duration of time. Thus, the seems to suggest that all really important activities demand a long time to benefit, since they are almost invariably connected with greater efforts. While the dialogue proves thereby to be an ethical one, the various time expressions also gain an ethical dimension.