High rate of biological removal of sulfate, organic matter, and metals in UASB reactor to treat synthetic acid mine drainage and cheese whey wastewater as carbon source.

The anaerobic biological treatment of sulfate-rich effluents, such as acid mine drainage (AMD), is mediated by sulfate-reducing bacteria (SRB). This process involves the reduction of sulfates in the presence of an electron donor. Complex carbon compounds can be used as electron donors. In the present study, was used an upflow anaerobic sludge blanket (UASB) reactor to co-treat a low-pH synthetic AMD and cheese whey wastewater (CWW). Were observed higher sulfate and COD removal rates (1,114 ± 88 and 1,214 ± 128 mg L-1  day-1 , respectively) at higher sulfate and applied COD loading rates (1,500 mg L-1  day-1 ). The overall pH of the effluent remained above 6.4 without any bicarbonate supplementation. Almost 100% of the Fe, Zn, and Cu was removed and the presence of metals improved the process. The use of a single reactor to treat AMD and CWW is promising. PRACTITIONER POINTS: Wastewater cheese whey was electron donor for treating acid mine drainage in an UASB reactor. Metals additions in the system indicated an increased removal of COD. About 99% of the metals were removed with the treatment.

Targeting fibroblast activation protein inhibits tumor stromagenesis and growth in mice.

Membrane-bound proteases have recently emerged as critical mediators of tumorigenesis, angiogenesis, and metastasis. However, the mechanisms by which they regulate these processes remain unknown. As the cell surface serine protease fibroblast activation protein (FAP) is selectively expressed on tumor-associated fibroblasts and pericytes in epithelial tumors, we set out to investigate the role of FAP in mouse models of epithelial-derived solid tumors. In this study, we demonstrate that genetic deletion and pharmacologic inhibition of FAP inhibited tumor growth in both an endogenous mouse model of lung cancer driven by the K-rasG12D mutant and a mouse model of colon cancer, in which CT26 mouse colon cancer cells were transplanted into immune competent syngeneic mice. Interestingly, growth of only the K-rasG12D-driven lung tumors was also attenuated by inhibition of the closely related protease dipeptidyl peptidase IV (DPPIV). Our results indicate that FAP depletion inhibits tumor cell proliferation indirectly, increases accumulation of collagen, decreases myofibroblast content, and decreases blood vessel density in tumors. These data provide proof of principle that targeting stromal cell-mediated modifications of the tumor microenvironment may be an effective approach to treating epithelial-derived solid tumors.

Comparison of theoretical and experimental data to evaluate substrate diffusional limitations for crown ether- and methyl-beta-cyclodextrin-activated serine protease subtilisin Carlsberg in tetrahydrofuran.

Simple co-lyophilization of serine protease subtilisin Carlsberg with [12]-crown ether-4 (12-crown-4) or methyl-beta-cyclodextrin (MbetaCD) drastically increases its catalytic activity in organic solvents. We investigated whether the improved activity would cause substrate diffusional limitations. To experimentally assess the issue, the enzyme was inactivated with PMSF. Different amounts of active and inactive subtilisin were codissolved in 10 mM phosphate buffer (pH 7.8) followed by lyophilization with or without 12-crown-4 or MbetaCD. Initial rates for the transesterification reaction of N-acetyl-L-phenylalanine ethyl ester and 1-propanol in anhydrous THF were plotted vs. the amount of active enzyme present in the formulations. For all three enzyme formulations a linear relationship was observed and the results clearly show that activation of subtilisin Carlsberg by crown ethers and MbetaCD did not cause diffusional limitations. This was somewhat surprising because theoretical models predicted such diffusional limitations for the activated formulations. However, investigation of the protein powder particles obtained after co-lyophilization with 12-crown-4 and MbetaCD revealed a drastically reduced particle size for these formulations when suspended in THF. The particle micronization afforded by the excipients prevented substrate diffusional limitations, a factor that should be taken into account when designing improved enzyme formulations for synthetic applications in organic solvents.