利用热带假丝酵母（Candida tropicalis）突变株SP-UV-56进行十三碳二元酸发酵，研究了pH值控制模式对产酸的影响。低pH值对维持菌体活性有利，但不利于菌体产酸；高pH值能促进菌体产酸，但菌体活性有所下降。在研究中定义了3个参数pHe值、Cp，e和ΔpHe。菌体的产酸与ΔpHe有关，通过实验建立了pHe值与产酸量Cp,e之间的关联式，提出了pH值梯度控制策略，并确定了适宜的ΔpHe。以ΔpHe=012为推动力，建立了pH值连续控制方程。应用pH值连续控制方程进行发酵，转化120h产酸量达到145.2g·L-1，较对照组的产酸量提高了16%，适宜的pH值控制范围为715～812，为长链二元酸发酵技术实现pH值连续自动控制奠定了理论基础。

利用Klebsiella pneumoniae生长与催化耦合的特点，将好氧生长与厌氧转化两个过程耦合，开发了两段双底物发酵生产1,3-丙二醇的新工艺，并对其工艺特点进行了初步研究。结果表明，采用两段双底物发酵工艺，发酵过程菌体浓度明显高于传统的厌氧转化工艺，OD650最大值达到9.37，发酵60h,1,3-丙二醇的浓度达到50.16g/L，生成速率达0.836g/(L×h)，比传统工艺提高了45%。

运用顺磁共振、电镜、能谱等手段研究了寡聚糖对红豆杉细胞氧化还原生。理态势的影响。结果表明，诱导前红豆杉细胞处于相对稳定的生长态势，细胞完整，细胞器发达；氧化还原电势较低，活性氧相关酶系统相对稳定, 细胞初生代谢旺盛，紫杉醇合成速率很低。诱导后红豆杉细胞向产物合成态势转移，SOD酶活性迅速提高，CAT和POD酶活被强烈抑制；细胞出现活性氧迸发，4h达最大值；细胞的氧化还原电势增高，细胞膜上离子通道被激活，H+和Ca2+ 内流，Cl-外流；液胞内出现大量含Ca2+离子的高电子致密区并呈规律性变化，培养环境碱化；细胞生长被抑制，紫杉醇合成速率升高，其产量提高了515倍，达7611mg·L-1。

综述了近年来工业生物催化过程的发展，提出按照生物催化剂的制备和催化过程的特点将工业生物催化分成生长耦联型催化和生长非耦联型催化，通过这两类生物催化成功的范例以及研究进展讨论生物催化工业化的途径和方法及进一步发展的方向和对策。

研究了谷氨酰胺发酵液中盐离子对纳滤分离提取谷氨酰铵的作用，系统地考察了操作温度和发酵液组成对纳滤分离透过特性的影响，确定了纳滤分离时发酵液最佳稀释倍数和操作温度。结果表明，二价阳离子通过改变膜面电荷密度对谷氨酸的透过特性产生很大影响，使其截留率降低了8%。发酵液中较高浓度的（NH4）2SO4使谷氨酸和谷氨酰胺的截留率和透过通量明显降低，但较高浓度的NH4Cl影响较小，这体现了纳滤膜对不同离子排斥力的差异。当发酵液稀释至谷氨酰胺浓度为1%，pH调至7时，发酵液中的其它盐离子和残糖因浓度较低而对纳滤分离影响不显著。

The intracellular pH (pHi) of a,dicarboxylic acid producing Candida tropicalis was determined by a fluorescence technique using the pH-sensitive fluorescent probe 5(6)-carboxyfluorescein diacetate. Fermentations with n-tridecane substrate to produce a,-tridecanedioic acid were carried out in a 5-l bioreactor in which growth and production were separated. During the growth phase, the measured pHi values were varied from 5.65 to 6.15 in all the experiments performed under different constant pH-operating conditions. The specific rates of growth, sucrose consumption, CO2 production, and O2 consumption were correlated with pHi. Cytochrome P450 monooxygenase (P450), which catalyzes n-alkane hydroxylation, was only slightly expressed during the growth phase. During the first 6h of the production phase, P450 activity was induced rapidly accompanying higher pHi. A much higher level of P450 activity was observed at pHi of 6.55

The effects of oligosaccharide from Fusarium oxysprum on secondary metabolisms in suspension cultures of Taxus chinensis var. mairei were investigated by detecting the oxidative burst (OB) signals using an Electron Paramagnetic Resonance (ESR) spectrometer. The oxidative burst signals induced by oligosaccharide gradually increased to a maximum at 4h. Phenylalanine ammonia lyase (PAL) and polyphenol oxidase (PPO) activities were respectively 2 and 4 times higher than those of control, and large amount of phenolics were accumulated in culture medium. Two times of obvious increase in taxol production was observed, which was in accordance with the two times of elicitation of oxidative burst signals. The dependence of taxol production on the intensity of OB signals obeyed a modified Logistic curve. It was inferred that the syntheses of the side chain and nucleus of taxol were enhanced at low and high intensities of OB signals, respectively.

A non-linear cascade model is proposed to describe the signal transduction pathway in suspension cultures of Taxus chinensis var. mairei induced by an oligosaccharide from Fusarium oxysporum. The oxidative burst intensity, which was defined as the amount of the free radicals including superoxide anion (O2·), H2O2 and OH− and measured by ESR spectrometry, was used as the signal characteristic and the theory of electronic signal transduction cascade was then applied to derive the initial model. The model shows that the signal transduction cascade process is composed of three cascade nets, represented by the phosphorylation of a G-protein, activation of an ion channel and phospholipase C, and phosphorylation of protein kinase C. The three reactions were calculated as beginning at 30.5, 48.8 and 141.4min after elicitation, and the maximum variation rates of the signal intensity in the three nets occurred at 43.2, 80.6 and 192.6min, respectively. The validity of the model predictions was verified by experimental data.

A structured kinetic model was established to describe the process of Taxol formation in suspension cultures of Taxus chinesis var. mairei induced by an oligosaccharide from Fusarium oxysporum. In this model, the role of intracellular starch as a storage carbon source had to be taken into account. Substrate uptake, culture growth, cell respiration, and secondary metabolites, predicted by the model, agreed with those obtained experimentally. The effective factors of oligosaccharide elicitation, ηe,j, defined as the ratio of the parameter values in the system with oligosaccharide to those in control, reflected the effects of the oligosaccharide on cell growth and Taxol production.

Separation of l-glutamine (l-Gln) from Gln fermentation broth by nanofiltration (NF) was investigated with NTR7450 NF membrane. The effects of various experimental parameters such as transmembrane pressure, pH and concentration of broth on the rejection of l-Gln and l-glutamate (l-Glu) showed that NTR7450 was able to effectively separate l-Gln and l-Glu when the appropriate conditions were chosen. Moreover, the rejection of l-Gln and l-Glu in a single amino acid solution was also studied with the variation of pH, concentration, and physicochemical parameters. It was demonstrated that deviations in the rejection of fermentation broth from a single l-Gln or l-Glu solution were mainly caused by the complex ionic composition of the real fermentation broth.