• Journal of Microbiology and Biotechnology
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• 제9권2호
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• pp.140-146
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• 1999

When methanol was the sole carbon source, Methylobacterium organophilum NCIB 11278, a facultative methylotroph, accumulated Poly-$\beta$-hydroxybutyrate (PHB) as 59% (w/w) of dry cell weight under potassium limitation, 37% under sulfate limitation, and 33% under nitrogen limitation. Based on a stoichiometric analysis of PHB synthesis from methanol, it was suspected that PHB synthesis is accompanied by the overproduction of energy, either 6-10 ATP and 1 $FADH_2$ or 6 ATP and 3 NADPH to balance the NADH requirement, per PHB monomer. This was confirmed by observation of increased intracellular ATP levels during PHB accumulation. The intracellular ATP with limited potassium, sulfate, and ammonium increased to 0.185, 0.452, and 0.390 $\mu$moles ATP/g Xr (residual cell mass) during PHB accumulation, respectively. The intracellular ATP level under potassium limitation was similar to that when there was no nutrient limitation and no PHB accumulation, 0.152- 0.186 $\mu$moles ATP/g Xr. We propose that the maximum PHB accumulation observed when potassium was limited is a result of the energy balance during PHB accumulation. Microorganisms have high energy requirements under potassium limitation. Enhanced PHB accumulation, in ammonium and sulfate limited conditions with the addition of 2,4-dinitrophenol, which dissipates surplus energy, proves this assumption. With the addition of 1 mM of 2,4-dinitrophenol, the PHB content increased from 32.4% to 58.5% of dry cell weight when nitrogen limited and from 15.1 % to 31.0% of dry cell weight when sulfate limited.

• Journal of Microbiology and Biotechnology
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• 제30권7호
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• pp.1051-1059
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• 2020

Overproduction and accumulation of melanin in the skin will darken the skin and cause skin disorders. So far, components that can inhibit tyrosinase, a melanin synthase of melanocytes, have been developed and used as ingredients of cosmetics or pharmaceutical products. However, most of existing substances can only inhibit the biosynthesis of melanin while melanin that is already synthesized and deposited is not directly decomposed. Thus, their effects in decreasing melanin concentration in the skin are weak. To overcome the limitation of existing therapeutic agents, we started to develop a substance that could directly biodegrade melanin. We screened traditional fermented food microorganisms for their abilities to direct biodegrade melanin. As a result, we found that a kimchi-derived Pediococcus acidilactici PMC48 had a direct melanin-degrading effect. This PMC48 strain is a new strain, different from P. acidilactici strains reported so far. It not only directly degrades melanin, but also has tyrosinase-inhibiting effect. It has a direct melanin-decomposition effect. It exceeds existing melanin synthesis-inhibiting technology. It is expected to be of high value as a raw material for melanin degradation drugs and cosmetics.

• Clinical and Experimental Pediatrics
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• 제55권2호
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• pp.42-47
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• 2012

$Mycoplasma$ $pneumoniae$ (MP), the smallest self-replicating biological system, is a common cause of upper and lower respiratory tract infections, leading to a wide range of pulmonary and extra-pulmonary manifestations. MP pneumonia has been reported in 10 to 40% of cases of community-acquired pneumonia and shows an even higher proportion during epidemics. MP infection is endemic in larger communities of the world with cyclic epidemics every 3 to 7 years. In Korea, 3 to 4-year cycles have been observed from the mid-1980s to present. Although a variety of serologic assays and polymerase chain reaction (PCR) techniques are available for the diagnosis of MP infections, early diagnosis of MP pneumonia is limited by the lack of immunoglobulin (Ig) M antibodies and variable PCR results in the early stages of the infection. Thus, short-term paired IgM serologic tests may be mandatory for an early and definitive diagnosis. MP infection is usually a mild and self-limiting disease without specific treatment, and if needed, macrolides are generally used as a first-choice drug for children. Recently, macrolide-resistant MP strains have been reported worldwide. However, there are few reports of apparent treatment failure, such as progression of pneumonia to acute respiratory distress syndrome despite macrolide treatment. The immunopathogenesis of MP pneumonia is believed to be a hyperimmune reaction of the host to the insults from MP infection, including cytokine overproduction and immune cell activation (T cells). In this context, immunomodulatory treatment (corticosteroids or/and intravenous Ig), in addition to antibiotic treatment, might be considered for patients with severe infection.

• The Korean Journal of Physiology and Pharmacology
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• 제16권2호
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• pp.107-112
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• 2012

Although various derivatives of caffeic acid have been reported to possess a wide variety of biological activities such as neuronal protection against excitotoxicity and anti-inflammatory property, the biological activity of 3,4,5-trihydroxycinnamic acid (THC), a derivative of hydroxycinnamic acids, has not been clearly examined. The objective of the present study is to evaluate the anti-inflammatory effects of THC on lipopolysaccharide (LPS)-stimulated BV2 microglial cells. THC significantly suppressed LPS-induced excessive production of nitric oxide (NO) and expression of iNOS, which is responsible for the production of iNOS. THC also suppressed LPS-induced overproduction of pro-inflammatory cytokines such as IL-$1{\beta}$and TNF-${\alpha}$ in BV2 microgilal cells. Furthermore, THC significantly suppressed LPS-induced degradation of $I{\kappa}B$, which retains NF-${\kappa}B$ in the cytoplasm. Therefore, THC attenuated nuclear translocation of NF-${\kappa}B$, a major pro-inflammatory transcription factor. Taken together, the present study for the first time demonstrates that THC exhibits antiinflammatory activity through the suppression of NF-${\kappa}B$ transcriptional activation in LPS-stimulated BV2 microglial cells.

• Nutrition Research and Practice
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• 제8권3호
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• pp.267-271
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• 2014

BACKGROUND/OBJECTIVES: Overproduction of nitric oxide (NO) by the inducible nitric oxide synthase (iNOS) enzyme can cause inflammation. Cyclooxygenase-2 (COX-2) is also involved in the inflammatory response through regulation of nuclear factor-kappa B $NF-{\kappa}B$(). Areca catechu is one of the known fruit plants of the Palmaceae family. It has been used for a long time as a source of herbal medicine in Indonesia. In this study, we explored the effect of Indonesian Areca catechu leaf ethanol extract (ACE) in lipopolysaccharide (LPS)-induced inflammation and carrageenan-induced paw edema models. Recently, this natural extract has been in the spotlight because of its efficacy and limited or no toxic side effects. However, the mechanism underlying its anti-inflammatory effect remains to be elucidated. MATERIALS/METHODS: We measured NO production by using the Griess reagent, and determined the expression levels of inflammation-related proteins, such as iNOS, COX2, and $NF-{\kappa}B$, by western blot. To confirm the effect of ACE in vivo, we used the carrageenan-induced paw edema model. RESULTS: Compared to untreated cells, LPS-stimulated RAW 264.7 cells treated with ACE showed reduced NO generation and reduced iNOS and COX-2 expression. We found that the acute inflammatory response was significantly reduced by ACE in the carrageenan-induced paw edema model. CONCLUSION: Taken together, these results suggest that ACE can inhibit inflammation and modulate NO generation via downregulation of iNOS levels and $NF-{\kappa}B$ signaling in vitro and in vivo. ACE may have a potential medical benefit as an anti-inflammation agent.

• The Korean Journal of Physiology and Pharmacology
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• 제18권6호
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• pp.481-487
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• 2014

Ischemic postconditioning (IPost) could decrease ischemia-reperfusion (IR) injury. It has not yet reported whether IPost is useful when ischemic heart disease is accompanied with co-morbidities like hyperthyroidism. The aim of this study was to examine the effect of IPost on myocardial IR injury in hyperthyroid male rats. Hyperthyroidism was induced with administration of thyroxine in drinking water (12 mg/L) over a period of 21 days. After thoracotomy, the hearts of control and hyperthyroid rats were perfused in the Langendorff apparatus and subjected to 30 minutes global ischemia, followed by 120 minutes reperfusion; IPost, intermittent early reperfusion, was induced instantly following ischemia. In control rats, IPost significantly improved the left ventricular developed pressure (LVDP) and ${\pm}dp/dt$ during reperfusion (p<0.05); however it had no effect in hyperthyroid rats. In addition, hyperthyroidism significantly increased basal $NO_x$ (nitrate+nitrite) content in serum ($125.5{\pm}5.4{\mu}mol/L$ vs. $102.8{\pm}3.7{\mu}mol/L$; p<0.05) and heart ($34.9{\pm}4.1{\mu}mol/L$ vs. $19.9{\pm}1.94{\mu}mol/L$; p<0.05). In hyperthyroid groups, heart $NO_x$ concentration significantly increased after IR and IPost, whereas in the control groups, heart $NO_x$ were significantly higher after IR and lower after IPost (p<0.05). IPost reduced infarct size (p<0.05) only in control groups. In hyperthyroid group subjected to IPost, aminoguanidine, an inducible nitric oxide (NO) inhibitor, significantly reduced both the infarct size and heart $NO_x$ concentrations. In conclusion, unlike normal rats, IPost cycles following reperfusion does not provide cardioprotection against IR injury in hyperthyroid rats; an effect that may be due to NO overproduction because it is restored by iNOS inhibition.

• 한국식품영양과학회지
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• 제36권3호
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• pp.305-310
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• 2007

복분자, 산수유 및 토사자를 일정한 비율로 배합하여 열수추출로 얻어진 KH-305를 일반쥐에 투여해서 해면체 평활근 이완에 관련된 세포 내 신호전달체계 NO-cGMP pathway에 관여하는 NOS, 혈액내의 testosterone, BVSMCs cell에서 cGMP농도를 측정하여 음경발기 지속 및 촉진에 미치는 영향을 보았으며 음경조직의 활성산소제거와 관련하여 SOD/Mn, SOD/Cu의 단백질 발현정도를 측정하였다. KH-305는 NO-pathway에 관여하는 NOS의 발현증가, 낮은 농도에서의 cGMP농도 증가, testosterone의 수치를 증가시킴으로써 발기유지 및 촉진시키고, 동시에 음경조직내의 활성산소 및 NO 합성에서 나타나는 독성을 조절하여 주는 SOD발현이 증가됨으로써 활성산소에 의한 음경피로도를 경감시켜 음경해면체 평활근의 이완장애를 일으키는 발기부전 증상을 개선시킬 것으로 생각된다.

• KSBB Journal
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• 제10권2호
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• pp.196-203
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• 1995

국내에서 선멸된 Streptomyces sp. 809-11 균주의 항생물질 polyoxins의 생합성 능력을 향상시키기 위하여 주요 영양원에 따른 균체의 중식 및 polyoxins 의 생합성에 미치는 영향을 조사하였다. 본 실험결 과 가용성 전분만을 사용한 배지에서는 초기 대수척 성장기의 균체량은 증가하였으나 polyoxins의 생합 성량은 적게 나타났으며, 포도당만을 이용한 경우는 사상균사체의 형성을 증가시켜 polyoxins의 생합성 량을 증가시켰으나 초기 균체의 성장률은 매우 저조 하였다. 따라서 균체의 성장과 polyoxins의 생합성 향상 두 가지 측면을 모두 고려하여 볼 때 탄소원 으로 가용성 전분과 포도탕을 혼용하여 사용하는 것이 바람직한 것으로 나타났다. 질소원으로 사용한 $(NH_2)_4S0_4$는 비교적 고놓도인 151.4mM에서 최대 항생제 생합성량을 보여주었으며, 인산염으로 사용된 $K_2HPO_4$는 0.5mM 정도에서 최적의 poly oxms 생합성을 보여 주였다. 유가식배양을 도입하 여 초기에는 균체 성장을 위하여 전분과 포도탕이 함유된 배지에서 배양하였고, 탄소원의 고갈시점에 는 사상 균사체의 분화 촉진을 위하여 포도당을 공 급한 결과 polyoxins의 생합성량을 회분식 배양에 비하여 두 배 이상으로 증가시켰다.

• KSBB Journal
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• 제9권1호
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• pp.16-25
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• 1994

Bacillus subtilis를 재조합 이종 단백질 생산 균주로 만들기 위하여 포자형성 변이주를 만들었다. 균주는 두 개의 프로테아제가 제거된 균주인 DB104로부터 spoOJ와 spoIIG 변이주를 유전자 조작법에 의해 만들고 두 개의 유전자가 모두 제거된 균주도 만들었다. 이에 목적 aprE 유전자를 삽입 벡터 형태로 만들어 integration시킨 뒤 변이주 각각의 형태적인 변화를 투과성 전자현미경으로 살펴 보았다. 각각 변이주의 모습은 이전에 보고된 것과 거의 일치하였으며 spoOJ spoIIG 이중포자변이주의 경우는 spoIIG 변이주와 더욱 닮은 것을 알 수 있었으며, 훨씬 주름진 것과 같은 투박한 세포벽 및 막을 가지고 있음을 관찰하였다. spoOJ 변이는 포자형성 빈도를 낮추고 aprE 활성을 감소시키는 반면, spoIIG 변이는 포자형성을 거의 하지 않으면서 aprE 활성에 상승효과를 가져왔다. spoOJ와 spoIIG 이중포자변이주는 spoOJ 변이의 효과는 거의 나타나지 않은채, spoIIG와 비슷한 aprE 활성을 보였다.

• BMB Reports
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• 제35권1호
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• pp.116-126
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• 2002

Nitric oxide (NO), synthesized from L-arginine by NO synthases, is a small, lipophilic, diffusible, highly reactive molecule with dichotomous regulatory roles in many biological events under physiological and pathological conditions. NO can promote apoptosis (pro-apoptosis) in some cells, whereas it inhibits apoptosis (anti-apoptosis) in other cells. This complexity is a consequence of the rate of NO production and the interaction with biological molecules such as metal ion, thiol, protein tyrosine, and reactive oxygen species. Long-lasting overproduction of NO acts as a pro-apoptotic modulator, activating caspase family proteases through the release of mitochondrial cytochrome c into cytosol, up-regulation of the p53 expression, and alterations in the expression of apoptosis-associated proteins, including the Bcl-2 family. However, low or physiological concentrations of NO prevent cells from apoptosis that is induced by the trophic factor withdrawal, Fas, $TNF{\alpha}$/ActD, and LPS. The anti-apoptotic mechanism is understood on the basis of gene transcription of protective proteins. These include: heat shock protein, hemeoxygenase, or cyclooxygenase-2 and direct inhibition of the apoptotic executive effectors caspase family protease by S-nitrosylation of the cysteine thiol group in their catalytic site in a cell specific way. Our current understanding of the mechanisms by which NO exerts both pro- and anti-apototic action is discussed in this review article.