Papers by Author: Gaung Ming Zhang

Abstract: 17-Estradiol (E2) and Bisphenol A (BPA) are important endocrine disrupting chemicals (EDCs). In this work, cell proliferation assay using cell cycle analysis method and determination of estrogen receptor α protein was used to investigated the mechanism and effects respectively and in mixture of the two EDCs in stimulating the growth of human breast cancer MCF-7 cell When the concentration of E2 and BPA were 10-12mol/L and 10-8mol/L respectively, E2 and BPA could reduce the express of ERα protein by activated ERα pathway, accelerated the cell cycle, decreased the percentages of cells in G0/1 phase, increased the percentages of cells in S phase at 48 h, and thus promoted the cancer cell growth. However, the combination effect of these two compounds did not induce the growth of cancer cell and the mixture reduced the ratio in S phase compared with E2 or BPA alone, which lead to weakening of the proliferation ability. There was a significant interaction between BPA and E2 and such a weakening effect had not been reported before.

Abstract: Photosynthetic bacteria (PSB) have various applications but the culture cost is very expensive. To find an efficient and economic culture medium the effects of yeast extract, C/N ratio, and trace elements on the growth of PSB were studied. The results showed that the optimal condition for PSB growth was: yeast extract of 100mg/l, C/N of 12:1, and trace elements (in mol/L): Mn2 + (0.009), Fe3+ (0.0025), Co2+ (0.0024), Cu2 + (0.0024), and Zn2 + (0.0033). Trace element lack could affect the growth of PSB. The order was Mn2 +> Fe3 +> Co2+> Cu2 +> Zn2 +. The improved medium was named HCH, and the optimum medium components were (in g/l) DL-malic acid: (4), MgSO4: (0.12), (NH4)2 SO4: (1), CaCl2: (0.075), KH2PO4: (0.5), K2HPO4: (0.3), Na2EDTA: (0.02), yeast extract : (0.1), trace elements 1ml (in mol/l ): Fe3+: (0.0025), Mn2+: (0.009), Zn2+: (0.0033), Co2+: (0.0024), pH:6.8. Comparing with the traditional RCVBN medium, in HCH medium yield of PSB increased 1.2 times and the cost decreased 19.8 times.

Abstract: A two stage bioreactor was employed in bioremediation study of laboratory simulated brewery wastewater. Two weeks anaerobic dark incubation of the artificial brewery wastewater without external seeding resulted in an effluent with 138mgl-1VFA; the chemical oxygen demand decreased from 10,000 to 7,814mgl-1 total nitrogen and total phosphorus recorded 18.63 and 18.95% reductions. Further treatment of the anaerobic effluent with a photobacterium named Z08, reduced both the pollutants (COD, TN, TP) and high energy molecules (VFA) significantly by 36.8, 67.5, 27.0, and 60% respectively. Addition of 200mgl-1 NH2-CO-NH2 to the effluent yielded the best result, reducing COD, TN, TP and VFA by 67.5, 68.9, 34.2 and 82%.