The purification of immunodominant native protein antigens from the culture filtrates of Mycobacterium tuberculosis is needed for the development of new vaccines and immunodiagnostic reagents against tuberculosis. In the present study, we conducted large scale purification of well-known secreted antigens, Ag85 complex, 38-kDa, and MTB12, from the culture filtrate proteins (CFPs) prepared from M. tuberculosis H37Rv grown as a surface pellicle on synthetic Sauton medium. The protein and antigen concentrations of culture filtrates were sufficiently increased after 6 week of culture. The MTB12 antigen was detected as early as 1 week of culture, and Ag85 complex and 38-kDa antigen were detected after 2 and 3 week of culture, respectively, by immunodiffusion with specific antiserum against 100-fold concentrated culture filtrates. For large-scale purification, the six-week-culture filtrates of M. tuberculosis H37Rv diluted 2.5-fold with 20 mM Tris-HCl, pH 8.3 were subjected to anion-exchange chromatography. The CFPs were eluted with 100 mM NaCl-20 mM Tris-HCl, pH 8.3 and concentrated by ultrafiltration. The concentrated CFPs were fractionated with ammonium sulfate, and followed by hydrophobic interaction chromatography and anion-exchange chromatography (FPLC). Eventually, 10 mg of Ag85 complex, 0.56 mg of 38-kDa, and 1.81 mg of MTB12 antigens were purified from 1 liter of the six-week-culture filtrates of M. tuberculosis H37Rv which contained 307.81 mg of protein of culture filtrate.

박준석 1) ‧ 김봉균 2) ‧ 김우석 3) ‧ 서대석 4) ‧ 김화중 1)* 1) 경북대학교 건설환경에너지공학부 2) 충남대학교 토목공학부 3) 금오공과대학교 건축학부 4) 동산콘크리트산업(주)

This paper presents the optimized mixing design of lightweight aerated concrete using hydrogen peroxide. Design of experiments in order to the optimized mixing design was applied and commercial program (MINITAB) was used. Statistical analysis was used to Box-Behnken (B-B) method in response surface analysis. The influencing factors of experimental are unit cement content, water ratio and hydrogen peroxide ratio. According to the analysis of variance, at the hardened state, water ratio and hydrogen peroxide ratio affects on dried density, compressive strength and bending strength of lightweight aerated concrete, but unit cement content affects on only dried density. In the results of response surface analysis, to obtain goal performance, the optimized mixing design for lightweight aerated concrete using hydrogen peroxide were unit cement content of 800 kg/m 3 , water ratio of 44.33% and hydrogen peroxide ratio of 10%.

No abstract

Mycobacterium tuberculosis likely reside within a granuloma as a dormant state. An area of necrosis forms at the center of lung granulomas. Within this area, the bacteria are deprived of nutrients and exposed to harsh conditions, including low pH and anoxia. The response of M. tuberculosis to low pH and low oxygen conditions was investigated in both cellular and extracellular proteins by two-dimensional polyacrylamide gel electrophoresis analysis and MALDI-TOF. Several proteins intensively expressed under low pH and/or hypoxic conditions were found. In the culture filtrate, PhoS1 (Rv0934) and ScoB (Rv2503c) were found in significant amounts under both the low oxygen and acidic stress conditions. These results indeed extend our understanding of acidic response as well as hypoxic in M. tuberculosis and provide an important insight into physiology of the latent bacilli.