cPCR 기법을 이용한 초기배양 pH에 의한 반추위 섬유소 분해 박테리아의 부착 및 발효에 관한 연구

김민석,성하균,김현진,이상석,장종수,하종규,Kim, M.S.,Sung, H.G.,Kim, H.J.,Lee, Sang-S.,Chang, J.S.,Ha, J.K. 한국축산학회 2005 한국축산학회지 Vol.47 No.4

본 연구는 배양초기 pH 조건이 F. succino- genes의 섬유소 부착과 섬유소 소화에 미치는 영향을 보고자 실시하였다. 선정된 specific primer를 이용하여 F. succinogenes의 genomic DNA로부터 445bp의 16S rDNA 절편을 증폭하여 205bp의 internal control을 제작하였고, cPCR 결과로부터 박테리아 수를 계산할 수 있는 표준곡선의 회귀식($r^2$>0.99)을 얻을 수 있었다. In vitro 배양초기 pH에 따른 F. succ- inogenes의 cellulose 부착을 cPCR로 모니터링한 결과, 발효과정 전 기간동안 초기 pH가 6.8과 6.2일 때 cellulose 건물 g당 부착 균주의 수가 pH 5.6일 때 보다 높았으나, pH 6.8과 6.2 사이에서는 큰 차이는 없었다(p>0.05). Cellulose 분해는 배양시간이 진행됨에 따라 증가 되었으며, 분해 정도는 pH가 증가함에 따라 더 높았다. 배양초기 pH가 6.8, 6.2 그리고 5.8일 때 48시간동안 감소한 pH는 각각 0.24, 0.58 그리고 0.16 이었다. 가스 생산량은 발효 시간이 경과함에 따라 pH가 높을수록 더 많았다. 결론적으로 발효 초기 pH는 F. succinogenes에 의한 cellulose 소화, 가스 생산, pH 변화 및 cellulose 부착에 큰 영향을 주었으며, 특히, 낮은 pH(5.8)에서는 섬유소 소화 및 박테리아 부착을 현저한 감소 시켰다. The cPCR technique was used to monitor rumen fermentation and attachment of Fibrobacter succinogenes to cellulose at different pH in the in vitro culture medium. The target fragments of 16S rDNA(445 bp) were amplified from genomic DNA of F. succinogenes with specific primers and internal controls(205 bp) were constructed. Cell counts were estimated from the amounts of genomic DNA, which was calculated from cPCR results. F. succinogenes in pH 6.8 and 6.2 showed apparently higher attachment than in pH 5.8 during all incubation time. There were some difference between pH 6.8 and 6.2 in the degree of attachment, but the different was not significant (P>0.05). Cellulose degradation increased in process of incubation time and the increasing rate was higher when initial pH was higher. The pH in culture medium decreased regardless of initial pH in course of incubation time. After 24 h of incubation, medium pH was dropped by 0.24, 0.58 and 0.16 units from original medium pH 6.8, 6.2 and 5.8, respectively. More gas was produced at higher initial pH in the same manner as in cellulose degradation. In summery, Initial pH of rumen culture in vitro significantly influenced cellulose digestion, gas production, pH change and bacterial attachment. Especially, low pH(5.8) resulted in much lower bacterial attachment and fiber digestion compared to higher medium pH.

합성폐수 내 인을 제거하기 위한 TiCl4 농도 및 초기 pH 최적조건 도출

신소연 ( So Yeun Shin ),김종호 ( Jong Ho Kim ),안종화 ( Johng Hwa Ahn ) 한국물환경학회 2015 한국물환경학회지 Vol.31 No.6

This study experimentally determined the effect of titanium tetrachloride (TiCl4) concentration ([TiCl4]) (0.25-0.55 mM) and initial pH (3-11) on phosphorus (P) removal in synthetic wastewater (2 mg P/L). The P removal efficiency increased when [TiCl4] increased. The P removal efficiency showed a parabolic trend with an inflection point at pH 7. At the molar ratio of TiCl4 and P>6.2, the P removal efficiency was over 90% and the residual P concentration was less than 0.2 mg/L. Within the design boundaries, the complete P removal could be achieved at 7.0≤initial pH≤8.5 and 0.43≤[TiCl4]≤0.55 mM. The final pH was over 5.8 at initial pH≥7.7 and [TiCl4]≥0.35 mM. The results showed that TiCl4 was effective in P removal in water so that it could be an alternative chemical for P removal.

합성폐수 내 인을 제거하기 위한 TiCl₄ 농도 및 초기 pH 최적조건 도출

신소연,김종호,안종화,Shin, So-Yeun,Kim, Jong-Ho,Ahn, Johng-Hwa 한국물환경학회 2015 한국물환경학회지 Vol.31 No.6

This study experimentally determined the effect of titanium tetrachloride (TiCl₄) concentration ([TiCl₄]) (0.25-0.55 mM) and initial pH (3-11) on phosphorus (P) removal in synthetic wastewater (2 mg P/L). The P removal efficiency increased when [TiCl₄] increased. The P removal efficiency showed a parabolic trend with an inflection point at pH 7. At the molar ratio of TiCl₄ and P>6.2, the P removal efficiency was over 90% and the residual P concentration was less than 0.2 mg/L. Within the design boundaries, the complete P removal could be achieved at 7.0≤initial pH≤8.5 and 0.43≤[TiCl₄]≤0.55 mM. The final pH was over 5.8 at initial pH≥7.7 and [TiCl₄]≥0.35 mM. The results showed that TiCl4 was effective in P removal in water so that it could be an alternative chemical for P removal.

음식물쓰레기 수소발효 시 pH 영향 및 축산폐수와의 혼합 발효

장해남(Hae Nam Jang) 유기성자원학회 2016 유기물자원화 Vol.24 No.4

현대의 집적된 산업 사회에서 자정능력을 초과하여 발생하는 막대한 양의 유기성폐자원은 수질, 토양, 대기 등 총체적인 환경오염을 유발하는 처리⋅곤란 물질로 전락하였고, 화석연료의 지속적인 사용에 따른 온실가스의 방출은 지구온난화를 촉진시켰다. 개발된 회분식 공정을 적용하는 음식물쓰레기 수소발효에서, 세계 최초로 수소 전환율과 초기 및 운전 pH와의 관계를 수학적으로 표현하였고, 동시에 최적화하였다. 최적 초기 및 운전 pH는 각각 7.50, 6.01이었다. 축산폐수를 음식물쓰레기의 수소발효에 보조기질로 첨가 시 pH 제어를 위해 요구되는 알칼리량을 감소시킴과 동시에 수소발생률도 크게 증대시킬 수 있음을 관찰할 수 있었다. In the modern industrial society, huge amount of organic wastes have exceeded the society’s self-cleaning capability, caused pollution of the whole environment, including water quality, soil, and the air, and become a big burden of waste treatment. Moreover, the emission of green house gases brought by the continual combustion of fossil fuels has facilitated the global warming. The simultaneous effect of initial and operational pH on H2 yield was expressed using mathematical equation and optimized. The optimal initial and cultivation pH was 7.50 and 6.01, respectively. Addition of livestock wastewater to food waste substantially decreased the amount of alkali requirement and also improved the H2 fermentation performance.

습식담지시 pH와 Ni/Mo 몰비가 Ni-Mo/AC 카바이드 촉매의 특성과 메탄건식개질 반응성에 미치는 영향

이동민,황운연,박형상,박성열,김성수 한국수소및신에너지학회 2014 한국수소 및 신에너지학회논문집 Vol.25 No.4

Activated charcoal supported nickel molybdenum carbide (carburized Ni-Mo/AC) catalysts wereprepared by wet-impregnation followed by temperature-programmed carburization using 20% CH4/H2 gas. Theeffects of pH and initial Ni/Mo mole ratio during wet-impregnation step on the characteristics of the carburizedNi-Mo/AC catalysts were investigated using ICP, XRD, XPS, BET and CO2-TPD techniques, and correlated withthe catalytic activity of the carburized Ni-Mo/AC in methane dry reforming reaction. Comparison of the resultsof methane dry reforming reaction kinetics with the results of characterization of the carburized Ni-Mo/AC catalystshowed that the catalytic activity in methane dry reforming reaction was higher at higher initial Ni/Mo mole ratioor at lower pH(3~natural value). This phenomenon was related to the crystal size of metallic Ni in the carburizedNi-Mo/AC catalyst.

전로슬래그의 입도 크기 및 폐수의 조건 변화에 따른 인산염 제거효율과 제거 속도상수에 관한 연구

이상호,황정재 대한상하수도학회 2012 상하수도학회지 Vol.26 No.6

The effluent quality of phosphorus is strengthened by the national standard to conserve water resources to lessen the eutrophication threat. The soluble phosphate in the wastewater effluent can be removed using the converter slag as solid waste produced through the steel making process. The experiments for removal efficiencies and removal constants were performed for this research with the artificial wastewater following several different conditions, particle size, phosphate concentration and initial pH. The correlation coefficients of Freundlich adsorption isothem were 0.9505 for PSA, 0.9183 for PSB, respectively. The removal efficiency was 87-94 % for PSA and 90-96 % for PSB respectively. The pH of the wastewater was elevated to pH 11.8 for the initial pH 8.5, phosphate removal efficiency was the highest as 84 % ~ 98 %. In case of 10 mg/L of the intial phosphate, the removal efficiency was 96 ~ 98 %. The more initial pH increases, the higher the reaction rate constant is.

Controlled pH- and glucose-responsive drug release behavior of cationic chitosan based nano-composite hydrogels by using graphene oxide as drug nanocarrier

Xiaowen Zhao,Xue Zou,Lin Ye 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.49 No.-

To realize tight control of hyperglycemia for diabetic patients, cationic chitosan (HTCC) based nanocompositehydrogels were prepared by using graphene oxide (GO) as nano-carrier for the model drug(bovine serum albumin, BSA). BSA intercalated into the layers of GO and the intercalation process wasmainly driven by the mutual electrostatic interaction. By introducing GO-BSA, a more compact GOcenterednetwork structure formed for the hydrogel. Compared with HTCC/BSA, HTCC/2.0wt%GO-BSAhydrogels exhibited a more distinct pH-/glucose-sensitivity and a much lower initial burst release, whichwas attributed to the compact structure and strong interactions among HTCC, GO and BSA in the hydrogelsystem

제강슬래그의 카드뮴 제거능 평가 및 필요반응시간 결정

이광헌,오명학,김은협,박준범 한국지반공학회 2011 한국지반공학회논문집 Vol.27 No.10

This study was focused on the reactivity of furnace slag against cadmium to design the vertical drain method with reactive column for improving contaminated sea shore sediment. The kinetic sorption test was performed by changing the initial concentration and pH. Using pseudo-second-order model, the reactivity of furnace slag was quantitatively analyzed. Equilibrium removal amount (q_e) of furnace slag increased and rate constant (k₂) decreased with the increase of initial cadmium concentration. With the increase of pH, the equilibrium removal amount (q_e) and rate constant (k₂) increased in the same initial concentration. Required retention time was related to the inverse of the product of the equilibrium removal amount (q_e) multiplied by rate constant (k₂). The required retention time could be used to design the length of reactive column.

Control of Reversible Self-Bending Behavior in Responsive Janus Microstrips

Oh, Myung Seok,Song, Young Shin,Kim, Cheolgyu,Kim, Jongmin,You, Jae Bem,Kim, Taek-Soo,Lee, Chang-Soo,Im, Sung Gap American Chemical Society 2016 ACS APPLIED MATERIALS & INTERFACES Vol.8 No.13

<P>Here, we demonstrate a simple method to systematically control the responsive self-bending behavior of Janus hydrogel microstrips consisting of a polymeric bilayer with a high modulus contrast. The Janus hydrogel microstrips could be easily fabricated by a simple micromolding technique combined with an initiated chemical vapor deposition (iCVD) coating, providing high flexibility in controlling the physical and chemical properties of the microstrips. The fabricated Janus hydrogel microstrip is composed of a soft, pH-responsive polymer hydrogel layer laminated with a highly cross-linked, rigid thin film, generating a geometric anisotropy at a micron scale. The large difference in the elastic moduli between the two layers of the Janus microstrips leads to a self-bending behavior in response to the pH change. More specifically, the impact of the physical and chemical properties of the microstrip on the self-bending phenomena was systematically investigated by changing the thickness and composition of two layers of the microstrip, which renders high controllability in bending of the microstrips. The curvature of the Janus microstrips, formed by self-bending, highly depends on the applied acidity. A reversible, responsive self-bending/ unbending exhibits a perfect resilience pattern with repeated changes in pH for 5 cycles. We envision that the Janus microstrips can be engineered to form complex 3D microstructures applicable to various fields such as soft robotics, scaffolds, and drug delivery. The reliable responsive behaviors obtained from the systematic investigation will provide critical information in bridging the gap between the theoretical mechanical analysis and the chemical properties to achieve micron-scale soft robotics.</P>

회분식 탈질 공정에서 외부 탄소원에 따른 탈질효과

윤동인,이진종,김동운,이기영 한국산업미생물학회 1998 한국미생물·생명공학회지 Vol.26 No.2

여러 가지 외부 탄소원(acetic acid, glucose, methanol, molasses)으로 활성 슬러지를 이용하여 탈질 효과를 살펴보았다. 질산성 질소와 아질산성 질소를 질소원으로 하는 혐기성 슬러지의 회분식 배양을 통해 탈질속도, COD 소비, 탈질율을 조사해 본 결과 molasses는 탈질속도나 COD 소비에서 glucose와 비슷하고 acetic acid나 methanol보다 높았으나, 탈질 효율에 있어서는 질산성질소나 아질산성 질소배지에서 30-40%가 암모니아로 축적되어 탈질 효율이 떨어졌다. 이러한 현상은 molasses와 glucose를 탄소원으로 이용한 경우 발효에 의해 pH저하를 초래하고 이로 인해 탈질 효율이 감소되는 것으로 생각된다. 따라서 초기 pH를 조절하고 외부 탄소원은 molasses를 이용, 탈질 효과를 조사한 결과 pH 8일 때 암모니아의 축적은 거의 없었으며 탈질 속도에 있어서도 acetic acid의 경우보다 12시간정도 빠른 24시간 안에 99% 이상 탈질 효율이 증가함을 알 수 있었다. Respiratory denitrification experiments were performed using different carbon sources (acetic acid, glucose, methanol, molasses). In the culture media with glucose and molasses, COD consumption and denitrification rates were higher than with acetic acid and methanol. However, up to 30-40% of reduced nitrate and nitrite were converted to ammonium in glucose and molasses media. In the culture media with acetic acid and methanol, ammonium was not accumulated. Some of the consumed COD seemed to be used by the acid formers for the acidification in glucose and molasses media. By initial pH control of with molasses media, higher denitrification rate (up to 99%) and faster response could be obtained.