The effects of temperature, agitation and aeration on glycoprotein GP-1 production by Streptomyces kanasenisi ZX01 in bench-scale fermentors were systematically investigated. The maximum final GP-1 production was achieved at an agitation speed of 200 rpm, aeration rate of 2.0 vvm and temperature of 30 °C. By using a dynamic gassing out method, the effects of agitation and aeration on volumetric oxygen transfer coefficient (k_La) were also studied. The values of volumetric oxygen transfer coefficient in the logarithmic phase increased with increase of agitation speed (from 14.53 to 32.82 h⁻¹) and aeration rate (from 13.21 to 22.43 h⁻¹). In addition, a successful scale-up from bench-scale to pilot-scale was performed based on volumetric oxygen transfer coefficient, resulting in final GP-1 production of 3.92, 4.03, 3.82 and 4.20 mg/L in 5 L, 15 L, 70 L and 500 L fermentors, respectively. These results indicated that constant volumetric oxygen transfer coefficient was appropriate for the scale-up of batch fermentation of glycoprotein GP-1 by Streptomyces kanasenisi ZX01, and this scale-up strategy successfully achieved 100-fold scale-up from bench-scale to pilot-scale fermentor.

The efficiency of enzymatic hydrolysis of cellulose can be improved by various pretreatments of the substrate. In order to increase the efficiency of enzymatic saccharification of the wheat straw, we determined the effect of different pretreatments on the physical structure, chemical components and enzymatic saccharification of wheat straw. Our results showed that combination of grinding and sodium hydroxide (NaOH) treatment had high effect on the enzymatic hydrolysis of wheat straws. The optimal pretreatment condition was to grind the wheat straws into the sizes of 120 meshes followed by treatment with 1.0% NaOH for 1.5 h (121°C/15psi). Under this condition, the cellulose content of wheat straw was increased by 44.52%, while the content of hemicellulose and lignin was decreased by 44.15% and 42.52%, respectively. Scanning Electronic Microscopy and infrared spectrum analyses showed that significant changes occurred in the structure of wheat straws after pretreatment, which is favorable for the hydrolysis and saccharification. Cellulase produced by Penicillium waksmanii F10-2 was used to hydrolyze the pretreated wheat straw and the optimal condition was determined to be 30 h of enzymatic reaction under the temperature of 55°C, pH 5.5 and substrate concentration of 3%.

Saponins are natural glycosides consisting of a triterpene or steroid aglycone with a range of pharmacological properties such as significant anti-tumor activity. In this article, we review our recent progress in the studies of the saponins possessing anticancer effects, especially anti-glioblastoma effects from twelve species of marine organisms and terrestrial plants. The anti-glioblastoma active saponins discovered by other researchers in recent decades are also reviewed and compared. Systematic extraction, isolation and structural elucidation on the saponin constituents from three species of starfishes, five species of sea cucumbers and four species of medicinal plants led to the identification of more than 129 saponins, among which 76 saponins are new compounds. Most of the new compounds were found to possess relatively rare structural features showing in vitro cytotoxicity against tumor cells, especially glioblastoma cells. Several saponins exhibited significant anti-glioblastoma effects in vivo by in situ administration (interstitial chemotherapy) and their haemolytic side effects were avoided in the tests. Multiple mechanisms of action, such as interfering with cell cycle progression, inducing apoptosis, promoting stabilization of microtubule, as well as several signal transduction pathways, were involved in their anticancer effects. The review provided valuable leads for pursuing new anti-glioblastoma drugs, and established a new viewpoint for further development of these marine and terrestrial organisms. The successful approach to administrate saponins in situ conquered the bottleneck in the development of saponins as new drugs— haemolytic effects. It means that saponins may be developed as potential chemotherapeutic agents in pursuing new antiglioblastoma drugs.