• Journal of Microbiology and Biotechnology
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• 제18권7호
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• pp.1298-1307
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• 2008

In this study, we investigated the inhibition effects of single and mixed heavy metal ions ($Zn^{2+},\;Ni^{2+},\;Cu^{2+},\;and\;Cd^{2+}$) on iron oxidation by Acidithiobacillus ferrooxidans. Effects of metals on the iron oxidation activity of A. ferrooxidans are categorized into four types of patterns according to its oxidation behavior. The results indicated that the inhibition effects of the metals on the iron oxidation activity were noncompetitive inhibitions. We proposed a reduced inhibition model, along with the reduced inhibition constant ($\alpha_i$), which was derived from the inhibition constant ($K_I$) of individual metals and represented the tolerance of a given inhibitor relative to that of a reference inhibitor. This model was used to evaluate the toxicity effect (inhibition effect) of metals on the iron oxidation activity of A. ferrooxidans. The model revealed that the iron oxidation behavior of the metals, regardless of metal systems (single, binary, ternary, or quaternary), is closely matched to that of any reference inhibitor at the same reduced inhibition concentration, $[I]_{reduced}$, which defines the ratio of the inhibitor concentration to the reduced inhibition constant. The model demonstrated that single metal systems and mixed metal systems with the same reduced inhibitor concentrations have similar toxic effects on microbial activity.

• 공업화학
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• 제19권3호
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• pp.277-286
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• 2008

본 논문은 미생물 성장 공정에서의 기질 저해에 관한 modified Haldane 모델의 이론적 유도를 다룬다. 생물학적 개념인 기질-수용체 복합체의 작동 메커니즘을 바탕으로 새로운 미생물학적 동특성인 N-중첩된 다중 기질 저해 모델의 유도와 더불어 일반화가 이론적으로 고찰되었는데, 이것은 효소 반응에서의 단순 기질 저해 메커니즘이 자연스럽게 확장된 것이다. 결과적으로, 본 기질 저해에 관한 modified Haldane 모델은 완전저해 기질농도라는 생물학적 상수를 포함하고 있는, 잘 설계된 4-파라메터 동특성 모델임이 밝혀졌다.

• KSBB Journal
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• 제13권6호
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• pp.730-734
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• 1998

An이ew식과 Aiba삭을 조합하여 에탄올 생산단주인 Saccharomyces cerevisiae ATCC 24858의 비성장속도를 당농도와 에탄올 농도의 함수로 표현하였다. 기침의 저해영향을 받지 않는 최대 당농도 $S_m$은 150 g/L이며 기질의 저해영향은 기질농도 S와 $S-S_{max}$항의 함수로 표현되었다. 최대 비성장 속도 ${\mu}max 는 0.49 hr^{-1}, Monod상수 K_s$는 19 g/L, Andrew식의 기질저해상수 $K_1$는 139 g/L이였다. 또한 비성장속도에 영향을 마치지 앓는 최대알콜농도 Pm이 존재하였으며 그 값은 2 g/L 이였다. 따라서 Aiba식에서 비성장속도에 영향을 미치는 에탄올 농도항은 P-Pm으보 표현되었다. 본 연구의 알코올생산균주에 대한 비성장속도의 완성된 수식은 디음과 같으며 이 수식에 위한 계산값은 평균오차 6% 내외의 범위에서 실험값과 일치하였다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
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• pp.33-36
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• 2004

Two biokinetic models (\circled1 Mrichaelis-Menten kinetics with competitive inhibition \circled2 with both competitive inhibition and Haldane inhibition) for reductive dechlorination were developed and compared with results from batch kinetic tests conducted over a wide range of PCE and TCE concentrations with two different dechlorinating cultures. At PCE concentrations lower than 300 $\mu$M, both model simulated the experimental results well. However, The kinetic model that incorporated both competitive and Haldane inhibitions much better simulated experimental data for PCE concentrations greater than 300-400 $\mu$M, and TCE concentrations at half its solubility limit (4000 $\mu$M). The PM culture showed Haldane inhibition constants of 900, 6000, 7000 $\mu$M for TCE, c-DCE and VC, indicating very weak Haldane inhibition for c-DCE and VC, while the EV culture had lower Haldane inhibition constants for TCE, c-DCE, and VC of 900, 750, and 750 $\mu$M, respectively. The BM culture had better transformation abilities than the individual cultures over a wide range of PCE and TCE concentrations. Modeling results indicated that a combination of competitive and Haldane inhibition kinetics is required to simulate dechlorination over a broad range of concentrations up to the solubility limits of PCE and TCE.

• Environmental Engineering Research
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• 제10권1호
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• pp.22-30
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• 2005

Nitrite accumulation is not unusual in batch processes such as sequencing batch reactor (SBR) with high-strength of ammonium or nitrate wastewaters. A possible mechanism of nitrite inhibition on Acinetobacter was depicted in a biochemical model, which the protonated species, nitrous acid form of nitrite, affects proton relating transport at the proton-pumping site crossing the cell membrane under unlimited carbon and phosphorus conditions. This effect exerts inhibition of phosphorylation under aerobic condition and yields low APT/ADP ratio, consequently decrease poly-P synthesis and phosphorus uptake from outside the cell in the model.

• 한국보육지원학회지
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• 제19권6호
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• pp.97-113
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• 2023

Objective: The purpose of this study is to investigate the effect of young children's behavioral inhibition on self-determination, examining the sequential mediating effects of mothers' parenting anxiety and autonomy support. Methods: Participants in this study were 225 mothers with children aged 6 years. An online survey was conducted, and SPSS Statistics 23.0 was used for basic analysis. The research model used the Process Macro 4.0 program. Results: The higher the level of behavioral inhibition, the lower the child's self-determination. Furthermore, a mediating effect was confirmed when parenting anxiety was added. However, in the single mediation model and the sequential mediation model in which autonomy support was added, the direct effects of behavioral inhibition temperament and parenting anxiety on self-determination disappeared. As a result, behavioral inhibition characteristics were found to have an indirect effect on self-determination through the sequential mediating effects of mother's parenting anxiety and autonomy support. Conclusion/Implications: If a mother with a child with a behaviorally inhibited temperament properly handles the negative emotions experienced during parenting based on her understanding of the child and supports the child to have a high degree of autonomy, she can enhance the child's right to self-determination.

• 대한환경공학회지
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• 제22권11호
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• pp.2037-2046
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• 2000

산성 혹은 염기성 pH가 활성슬러지 공정에 미치는 저해 작용은 비경쟁적 저해 동력학(noncompetitive inhibition kinetics)을 따르는 것으로 알려져 있으나, pH를 저해 물질의 농도항으로 정량화하기 어렵기 때문에 실질적으로 비경쟁적 저해 동력학식(noncompetitive inhibition kinetic equation)으로 해석하기 어렵다. 따라서 pH에 의한 저해 작용을 기술하는 경험식들이 여러 연구자들에 의해 개발되어 왔는데, 이들은 주로 산성 조건에 대해서만 적용 가능한 것들이다. 본 연구에서는 의사독성농도(pseudo toxic concentration, $C_{PT}$) 개념을 이용하여 pH가 활성슬러지 공정에 미치는 저해 영향을 정량화하는 기법을 개발하였고, 기존에 알려진 모델들과 비교하였다. 그 결과 $C_{PT}$ 개념을 이용한 모델은 넓은 범위의 pH에 대해 최대비성장속도(${\mu}_{max}$)의 감소를 비교적 정확하게 예측할 수 있었고, 같은 동력학식을 이용하여 산성 조건뿐만 아니라 염기성 조건에 대해서도 적용 가능한 것으로 나타났다. 또한 저해계수(inhibition coefficient. $K_I$)의 추정이 간단하다는 장점이 있다.

• 한국물환경학회지
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• 제33권1호
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• pp.8-14
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• 2017

Microcystis aeruginosa (M. aeruginosa) is a cyanobacterium species that can form harmful algal blooms in freshwater bodies worldwide. The use of pine needle extract (PNE) to control nuisance algae by allelopathic inhibition will be environmentally friendly and promising. PNE removed successfully upto 98% of M. aeruginosa at the following optimal conditions: pH 7, $25^{\circ}C$ of temperature, 100 rpm of mixing rate, 5 min of mixing time. These results was indicated that the amount of 1 g/L PNE was removed 1g dryweight/L of M. aeruginosa. The kinetic data showed substrate inhibition kinetics and maximum growth rate was obtained when the M. aeruginosa was grown in medium containing 0.5 g/L of initial concentration of PNE. Different substrate inhibition models were fitted to the kinetic data and found the Luong model was best. The model predicted kinetic parameters were in agreement with the experimental findings. The natural extract, PNE, can be a promising inhibition due to its high efficiency and low dose requirements.

• 한국물환경학회지
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• 제33권4호
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• pp.441-448
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• 2017

Microcystis aeruginosa (M. aeruginosa) is a cyanobacterium species that can form harmful algal blooms in freshwater bodies worldwide. The use of Artemisia asiatica extracts to control M. aeruginosa inhibition will be environmentally friendly and promising. Artemisia asiatica extracts removed successfully upto 88% of M. aeruginosa pH 8 at $25^{\circ}C$ of temperature. These results was indicated that the amount of 2.24 g/L Artemisia asiatica extracts was removed 1g dryweight/L of M. aeruginosa. The kinetic data showed substrate inhibition kinetics and maximum growth rate was obtained when the M. aeruginosa was grown in medium containing 2.5 g/L of initial concentration of Artemisia asiatica extracts. In the various growth control models, Luong model showed the highest correlation coefficient of 0.9916. Therefore, the Luong model was the most suitable control model for the growth control of M. aruginosa using Artemisia asiatica extracts. In conclusion, the growth control of M. aruginosa using Artemisia asiatica extracts can be applied in the field without controlling the temperature and pH of rivers and streams, and it is possible to control the growth of M. aruginosa efficiently in a short time. The natural extract, Artemisia asiatica extracts, can be a promising inhibition due to its high efficiency and low dose requirements.

• East Asian mathematical journal
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• 제36권1호
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• pp.81-90
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• 2020

Many compartment models assume a kinetically homogeneous amount of materials that have well-stirred compartments. However, based on observations from such processes, they have been heuristically fitted by exponential or gamma distributions even though biological media are inhomogeneous in real environments. Fractional differential equations using a specific kernel in Pharmacokinetic/Pharmacodynamic (PKPD) model are recently introduced to account for abnormal drug disposition. We discuss a tumor growth inhibition (TGI) model using fractional-order derivative from it. This represents a tumor growth delay by cytotoxic agents and additionally show variations in the equilibrium points by the change of fractional order. The result indicates that the equilibrium depends on the tumor size as well as a change of the fractional order. We find that the smaller the fractional order, the smaller the equilibrium value. However, a difference of them is the number of concavities and this indicates that TGI over time profile for fitting or prediction should be determined properly either fractional order or tumor sizes according to the number of concavities shown in experimental data.