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%。

Signal transduction pathway for oxidative burst and taxol production was studied in suspension cultures of Taxus chinensis var. mairei induced by oligosaccharide from Fusarium oxysprum. Suspension cells exhibited an oxidative burst approximately 4h after challenge with oligosaccharide. The secondary metabolism including accumulation of extracellular phenolics and taxol production were enhanced, while the alkalization of the outer medium and activity of phenylalanine ammonia lyase (PAL) was promoted significantly. Pretreatment with the tyrosine (Tyr) kinase inhibitor herbimycin A abolished the oxidative burst and the subsequent induction of taxol production within 15 min after addition of elicitor. Suramin, a G-protein inhibitor, inhibited the oxidative burst if added up to 30 min after oligosaccharide treatment. The oxidative burst was also induced by the ion channel generator amphotericin B. In contrast, the ion channel blocker anthracene-9-carboxylate acid and Ca2 channel blocker nifedipine inhibited the oxidative burst within 45min after treatment. Oligosaccharide rapidly induced Tyr phosphrylation of receptor, which was inhibited by herbimycin A and anthracene-9-carboxylate acid. These responses were also inhibited by phospholipase C-neomycin. The response time of oligosaccharide to phospholipase C pathway was ca at 60 min. These data suggested that the activation of ion channels and phospholipase C follow Tyr kinase and G-protein in the signal pathway leading to the oxidative burst.

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.

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

A crude extract from Fusarium oxysprum caused significant cell apoptosis in suspension cultures of Taxus chinensis var. mairei as determined by transmission electron microscopy, DNA gel electrophoresis and terminal deoxynucleotidyl transferase-mediated dUTP nick labeling (TUNEL) analysis. Cells of T. chinensis var. mairei responded to the fungal elicitors by altering the general phenylpropanoid pathway and affecting the biosynthesis of taxol. The activity of L-phenylalanine ammonia lyase (PAL) increased appreciably within the first 36h of elicitor treatment, and then decreased rapidly. A large quantity of phenolic compounds accumulated in the culture medium. The maximum concentration of taxol was three times higher than that of the control. Cell apoptosis and taxol production are closely relevant in elicitor-treated culture of T. chinensis var. mairei .