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Environment-friendly agro-materials tend to be preferred to chemical insecticides recently. For this reason, many studies are conducted to develop environment-friendly insecticides containing natural materials. The purpose of this study was to assess ecotoxicity for pepper extract and cassia oil (11.5+46%, A), pepper extract and cassia oil (23+34%, B), and pepper extract and lavender oil (40+10%, C). They are expected to prevent from pests especially diamondback moth, and can be used for agro-materials. Their formulation was emusifiable concentration (EC). Target species used to assess acute toxicity were aquatic invertebrate (Daphina magna), fish (Cyprinus carpio), honeybee (Apis mellifera L.) and earthworm (Eisenia fetida). The value of A, B, and C to aquatic invertebrate were 0.46, 1.9, 0.25 mg respectively and these values were moderately toxic according to standard of USEPA. In case of acute toxicity test to fish, the of A, B, and C were 1.9, 2.9, 3.8 mg respectively. A was category II in acute toxicity of fish and not acceptable to evaluation criteria of environment-friendly agro-materials. B and C were category III and acceptable. Acute contact and oral toxicity test to honeybee were conducted and the of A, B, and C were > 100 a.i. in both of tests. It indicated they were low toxic to honeybee. In case of acute toxicity test to earthworm, of A, B, and C were 695, 988, and 564 mg . In conclusion, pepper extract+cassia oil 57% EC and pepper extract+lavender oil 50% EC were expected to be used for environment-friendly insecticide materials with low risk against ecosystem and contribute to developing environment-friendly agro-materials.

These studies were attempted to investigate the change of microbial community of anode of microbial fuel cell using swine wastewater in the enrichment step with the lapse of time. Microbial fuel cells enriched by a 1 : 1 mixture of anaerobic digestive juices of the sewage treatment plant and livestock wastewater. Enrichment culture step was divided into three stages to indentify the microorganisms. It was separated by each lag phase, exponential phase, and stationary phase. These steps were determined by the change of the current value. The current after enrichment was generated about 0.84 ± 0.06 mA. We were cut out the different 17 bands in the DGGE fingerprint gel to do sequencing. The bands which the concentration was increasing or newly appearing with the lapse of time were included for this study. In the lag and exponential phase, Clostridium, Rhodocyclaceae, Bacteriodetes, and Uncultured bacterium etc. were detected. There were in the stationary phase Geobacter sp., Rhodocyclaceae, Candidatus, Nitrospira, Flavobactriaceae and uncultured bacterium etc. Geobactor among microorganisms detected in this study is known as the Electrochemically active microorganisms. It may include electrochemically active microorganisms to be considered as electrical activity microorganisms.

A gas-lift reactor having a high mass transfer coefficient (k L a = 80.28 h−1) for a relatively insoluble gas (carbon monoxide; CO) was used to enrich (homo)acetogens from animal feces. Samples of fecal matter from cow, rabbit, chicken, and goat were used as sources of inoculum for the enrichment of CO and H2 utilizing microbial consortia. To confirm the successful enrichment, the Hungate roll tube technique was employed to count and then isolate putative CO utilizers. The results of this work showed that CO and H2 utilizing consortia were established for each inoculum source after 8 days. The number of colony-forming units in cow, rabbit, chicken, and goat fecal samples were 3.83 × 109, 1.03 × 109, 8.3 × 108, and 3.25 × 108 cells/ml, respectively. Forty-two colonies from the animal fecal samples were screened for the ability to utilize CO/H2. Ten of these 42 colonies were capable of utilizing CO/H2. Five isolates from cow feces (samples 5, 6, 8, 16, and 22) were highly similar to previously unknown (homo)acetogen, while cow-7 has shown 99 % similarity with Acetobacterium sp. as acetogens. On the other hand, four isolates from chicken feces (samples 3, 8, 10, and 11) have also shown high CO/H2 utilizing activity. Hence, it is expected that this research could be used as the basis for the rapid enrichment of (homo)acetogenic consortia from various environmental sources.

Environmental gamma-ray dose rates were measured by using ultra-high sensitive LiF:Mg,Cu,Si thermoluminescence dosimeters (TLDs) during short-term burial. The resultant gamma-ray dose rates were compared with those measured by using optically stimulated luminescence (OSL) of Al 2 O 3 :C and assessed by using HPGe spectrometer. Regardless of the short-term burial and the change of environmental conditions as well as the mismatch of the effective atomic number ( Z eff ) with the soil (mainly SiO 2 ), good agreement was observed between the doses measured by TLDs and OSL dosimeters or the assessed doses. LiF:Mg,Cu,Si TLD has been found to be an effective alternative for the measurement of environmental gamma-ray annual dose rates for use in optical dating.

Marine macroalgae, Ceylon moss containing low lignin and high levels of fermentable sugar (42%), was tested as a potential fermentation feedstock for solventogenic clostridia (Clostridium tetanomorphum ATCC49273, Clostridium acetobutylicum ATCC824, Clostridium aurantibutyricum NCIMB10659, and Clostridium beijerinckii NCIMB8052). As a major carbohydrate of pretreated Ceylon moss (hydrolyzate of Ceylon moss, hCM; hydrolyzate of Agar, hA) is a galactose, four strains were tested to verify galactose availability: C. tetanomorphum was screened out, because it could not utilize galactose. The other strains were then cultivated with hCM or hA. As a result, C. acetobutylicum and C. aurantibutyricum showed bacterial growth with consumption of galactose in both hCM and hA, whereas C. beijerinckii did not grow on hA, possibly due to susceptibility to inhibitor(s) existed. Fatty acids and solvents were produced; substantiating the fact that Ceylon moss can be used as a biomass resource for biochemicals production.

A multiple membrane electrode assembly installed microbial fuel cell (mMEA-MFC) was operated to harvest bioelectricity from organic materials. In the mMEA-MFC reactor, four MEAs were installed and shared electrolyte solution. Each MEA displayed 0.68±0.02 V in open-circuit voltage (OCV) and 0.34±0.01 V in closed-circuit voltage (CCV) at 1 kΩ of external resistance. The MEAs in each of the three mMEA-MFC reactors were serially connected, and improved voltages were observed shortly after the series connection (2.06±0.03 V as OCV and 0.73±0.01 V as CCV, respectively). The OCV was increased ideally to the sum of OCV from the unit cells, while voltage losses were generated in series connection in the CCV mode. Even though the voltage losses were generated in CCV, the series connection between each MEA belongs to individually operated reactor increased the output voltage of mMEA-MFCs which sharing an electrolyte solution. Keywords: Microbial fuel cell, Series connection, Multiple membrane electrode assembly, Energy recovery, Wastewater treatment

A mathematical model of microbial kinetics was introduced to predict the overall volumetric gas–liquid mass transfer coefficient (kLa) of carbon monoxide (CO) in a batch cultivation system. The cell concentration (X), acetate concentration (Cace), headspace gas (Nco and N co 2 ), dissolved CO concentration in the fermentation medium (Cco), and mass transfer rate (R) were simulated using a variety of kLa values. The simulated results showed excellent agreement with the experimental data for a kLa of 13/hr. The Cco values decreased with increase in cultivation times, whereas the maximum mass transfer rate was achieved at the mid-log phase due to vigorous microbial CO consumption rate higher than R. The model suggested in this study may be applied to a variety of microbial systems involving gaseous substrates.

Five rigid graphite plates were embedded in evenly divided sections of sediment, ranging from 2 cm (A1) to 10 cm (A5) below the top sediment layer. The maximum power and current of the MFCs increased in depth order; however, despite the increase in the internal resistance, the power and current density of the A5 MFC were 2.2 and 3.5 times higher, respectively, than those of the A1 MFC. In addition, the anode open circuit potentials (OCPs) of the sediment microbial fuel cells (SMFCs) became more negative with sediment depth. Based on these results, it could be then concluded that as the anode-embedding depth increases, that the anode environment is thermodynamically and kinetically favorable to anodophiles or electrophiles. Therefore, the anode-embedding depth should be considered an important parameter that determines the performance of SMFCs, and we posit that the anode potential could be one indicator for selecting the anode-embedding depth.

INTRODUCTION AND OBJECTIVES: Melatonin is a powerful antioxidant and a scavenger of free radicals. Recently it is reported that adenosine could be used to downregulate cellular metabolism to achieve prolonged survival under hypoxic conditions. The aim of this study is to evaluate the effect of melatonin and cladribine (adenosine-based purine, pyrimidine nucleoside analogue) on apoptosis and changes its related proteins induced by ischemia/ reperfusion injury in rat bladder. METHODS: One hundred male SpragueDawley rats were divided into 5 groups: control group (sham operation), I/R (ischemia/ reperfusion) group, I/R plus melatonin treated (I/R+M) group, I/R plus cladribine treated (I/R+C) group and I/R plus melatonin and cladribine treated (I/R+M&C) group. Melatonin (10 mg/kg) and cladribine (10 mg/kg) were injected intraperitoneally 3 times/week for 2 weeks after ischemic injury of bladder. On post-op 14th day, tissue samples were obtained by cystectomy. TUNEL assay, mRNA and protein expressions associated with apoptosis were evaluated using RT-PCR and immunoblots. RESULTS: In TUNEL assay, section of group I/R tissue exhibits a significant increase in the number of TUNEL positive cells than the control group. I/R+M&C group showed significant decreased apoptosis than the other groups. I/R+M&C group was more activated cytokine related apoptosis pathway such as Jnk1, P38, Akt1 and Sphk1 than I/R group on mRNA and protein expression. Also expression of Caspase 3 and Sphk1 showed similar patterns between I/R+C and I/R+M&C group on protein expression. Synergy of combined therapy was not proved. But melatonin might directly suppress the expression of HIF-1a, whereas cladribine might increase expression of Sphk1 and consecutively SphK1 suppressed HIF-1a. CONCLUSIONS: These results show that melatonin is one of the most potent protectors against ischemia/ reperfusion injury of bladder and cladribine may have benefits in the treatment of ischemia/ reperfusion injury to the biochemical and histopathologic parameters.

Environment-friendly agro-materials are are likely to be preferred to chemical insecticides recently. For this reason, many studies are conducted to develop environment-friendly insecticides containing natural materials. This study was also conducted so as to assess ecotoxicity for Emulsifiable concentrate (EC) containing 30% of garlic extract or two plant essential oils (Zanthoxylum, Lemongrass) expected to prevent from pests and be used for agro-materials. Target species used to assess acute toxicity were invertebrate (Daphina magna), fish (Oryzias latipes), honeybee (Apis mellifera L.) and earthworm (Eisenia fetida). The EC50 values for of garlic extract 30% EC, Zanthoxylum oil 30% EC and lemongrass oil 30% EC to Daphina magna were 3.3, 10, and 10 mg L �1 , respectively. The category of garlic extract 30% EC was moderately toxic, while those of Zanthoxylum oil 30% EC and lemongrass oil 30% EC were slightly toxic according to standard of USEPA. EC50 for both of Zanthoxylum oil 30% EC and lemongrass oil 30% EC were more than 10 mg L �1 then they were considered as slightly toxicity. In case of acute toxicity test to fish, LC50 of garlic extract 30% EC was 3.3 mg L �1 . Zanthoxylum oil 30% EC and lemongrass oil 30% EC indicated LC50 >1 0 mg L �1 . Classification of acute toxicity to all test substances was in Korea criteria. Acute contact and oral toxicity test to Honeybee were conducted. As a result, LD50 of all test substances were more than 100 a.i. µg bee �1 in the acute contact test while LD50 of garlic extract 30% EC was 4.4 a.i. µg bee �1 and LD50 of Zanthoxylum oil 30% EC and lemongrass oil 30% EC were more than 100 a.i. µg bee �1 . In case of acute toxicity test to earthworm, LC50 of garlic extract 30% EC, Zanthoxylum oil 30% EC and lemongrass oil 30% EC were 267, 592, and 430 mg kg �1 , respectively. In conclusion, if the safety for earthworm is confirmed, these substances are expected to be use for environment-friendly insecticide materials with low risk against ecosystem and contribute to developing environment-friendly agro-materials.

Monitoring reverse osmosis (RO) membrane conditions is an important task because it helps reduce the operation and maintenance cost in the RO membrane desalination systems by achieving long membrane lifetime and energy saving. As biological interactions between the membrane itself and microorganism cause the rapid degradation of membrane performance, it is crucial to identify and quantify potential biofoulants that are sensitive to each specific RO membrane. This study proposed a biofouling prediction method that indirectly quantifies the degree of biofouling by comparing the fluorescence excitation-emission matrix (EEM) of foulants sampled on the fully fouled RO membrane and those of brine samples from currently operating RO system. The experiment showed that the similarity distance measured from the comparison between the two fluorescence EEMs tends to increase when brine samples were secured from relatively clean RO membranes.

Simultaneous electricity generation and distillery wastewater (DWW) treatment were accomplished using a thermophilic microbial fuel cell (MFC). The results suggest that thermophilic MFCs, which require less energy for cooling the DWW, can achieve high efficiency for electricity generation and also reduce sulfate along with oxidizing complex organic substrates. The generated current density (2.3 A/m(2)) and power density (up to 1.0 W/m(2)) were higher than previous wastewater-treating MFCs. The significance of the high Coulombic efficiency (CE; up to 89%) indicated that electrical current was the most significant electron sink in thermophilic MFCs. Bacterial diversity based on pyrosequencing of the 16S rRNA gene revealed that known Deferribacteres and Firmicutes members were not dominant in the thermophilic MFC fed with DWW; instead, uncharacterized Bacteroidetes thermophiles were up to 52% of the total reads in the anode biofilm. Despite the complexity of the DWW, one single bacterial sequence (OTU D1) close to an uncultured Bacteriodetes bacterium became predominant, up to almost 40% of total reads. The proliferation of the D1 species was concurrent with high electricity generation and high Coulombic efficiency.

Purpose: To determine whether the distance from skin to stone, as measured by computed tomography (CT) scans, could affect the stone-free rate achieved via extracorporeal shock wave lithotripsy (ESWL) in renal stone patients. Materials and Methods: We retrospectively reviewed the records 573 patients who had undergone ESWL at our institution between January 2006 and January 2010 for urinary stones sized from about 5 mm to 20 mm and who had no evidence of stone movement. We excluded patients with ureteral catheters and percutaneous nephrostomy patients; ultimately, only 43 patients fulfilled our inclusion criteria. We classified the success group as those patients whose stones had disappeared on a CT scan or simple X-ray within 6 weeks after ESWL and the failure group as those patients in whom residual stone fragments remained on a CT scan or simple X-ray after 6 weeks. We analyzed the differences between the two groups in age, sex, size of stone, skin-to-stone distance (SSD), stone location, density (Hounsfield unit: HU), voltage (kV), and the number of shocks delivered. Results: The success group included 33 patients and the failure group included 10. In the univariate and multivariate analysis, age, sex, size of stone, stone location, HU, kV and the number of shocks delivered did not differ significantly between the two groups. Only SSD was a factor influencing success: the success group clearly had a shorter SSD (78.25±12.15 mm) than did the failure group (92.03±14.51 mm). The results of the multivariate logistic regression analysis showed SSD to be the only significant independent predictor of the ESWL stone-free rate. Conclusions: SSD can be readily measured by CT scan; the ESWL stone-free rate was inversely proportional to SSD in renal stone patients. SSD may therefore be a useful clinical predictive factor of the success of ESWL on renal stones.

Purpose To assess the ability of preoperative variables to predict extracapsular extension (ECE) and positive surgical margin (PSM) in radical prostatectomy patients with prostate-specific antigen (PSA) levels of less than 10 ng/ml. Materials and Methods From January 2008 to December 2009, 121 patients with prostate cancer with PSA levels lower than 10 ng/ml who underwent radical prostatectomy were enrolled in the study. The differences in clinical factors (age, PSA, PSA density [PSAD], digital rectal examination [DRE] positivity, positive magnetic resonance imaging [MRI], Gleason sum, positive core number, and positive biopsy core percentage) with ECE and the presence of positive margins were determined and their independent predictive significances were analyzed. Results The ECE-positive patients had higher PSA, PSAD, and MRI-positive percentages, and PSM patients had higher PSA, PSAD, MRI-positive percentages, Gleason sum, and positive biopsy core percentages for prostate cancer. In the multivariate analysis, PSAD and MRI positivity were the best independent predictors for ECE, and PSA and PSAD were the best independent predictors of PSM. By receiver operating characteristic curve analysis, PSAD had better discriminative area under the curve value than did PSA for ECE (0.765 vs 0.661) and PSM (0.780 vs 0.624). The best predictive PSAD value was 0.29 ng/ml/cc for ECE and 0.27 ng/ml/cc for PSM. Conclusions PSAD has relevance to ECE (plus MRI findings) and PSM (plus PSA). PSAD might be a powerful predictor of ECE and PSM preoperatively in patients undergoing a radical prostatectomy with PSA levels of less than 10 ng/ml.

The LiF:Mg,Cu,Si thermoluminescence materials, recently developed at the laboratory, gain uprising popularity because the materials show several outstanding performance results such as high sensitivities for gamma radiation, flat energy responses with little fluctuation for photons, linear responses over the wide ranges of radiation doses and few residual electrons trapped in the holes. In this study, we investigated the impacts of the Mg concentration and the final thermal treatment conditions on the glow curve structure of LiF:Mg,Cu,Si material to enhance the ratio of high-temperature peak to main peak for the extended application of the two peaks in the high LET radiation dosimetry and in the high-temperature environment. Change in Mg concentration did not affect significantly the ratio of TL responses of high and main dosimetric glow peaks. With Mg concentration in the range from 0.35 to 0.45 mol% and a thermal treatment of 10 min in the range from 400 °C to 440 °C followed by the thermal treatment at 260 °C for 10 min (dual-step thermal treatment) resulted in the highest value of the ratio of TL response of high and main dosimetric glow peaks.

Purpose Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) exhibits variable lower urinary tract symptoms (LUTS). The aim of this study was to evaluate the incidence of LUTS and the efficacy of an anticholinergic agent in young and middle-aged CP/CPPS patients. Methods Ninety-six men with CP/CPPS were randomly assigned in a single-blind fashion and received either ciprofloxacin (group 1, 49 patients) or ciprofloxacin and solifenacin (5 mg/day; group 2, 47 patients) for 8 weeks. The National Institutes of Health chronic prostatitis symptom index (NIH-CPSI), the International Prostate Symptom Score (IPSS), and the International Index of Erectile Function-5 (IIEF-5) were used to grade the patients' symptoms and the quality of life impact at the start of the study, and at 4 and 8 weeks from the initiation of the study. Results There was no significant difference between groups 1 and 2 with respect to age, duration of disease, or sub-domains of the IPSS, NIH-CPSI, or IIEF-5 at baseline. Of these patients, 67.4% had LUTS. Statistically significant differences were determined via the NIH-CPSI for total score and the pain and urinary domain scores. Statistically significant differences were determined via the IPSS for total score and the storage domain score. The total score of the IIEF-5 increased, but the change was not significant. There was no statistically significant difference in residual urine. Conclusions Many CP/CPPS patients had LUTS. Solifenacin in CP/CPPS demonstrated improvements in the NIH-CPSI and the IPSS total score and storage score. Storage factors significantly improved via the NIH-CPSI and IPSS assessments in the solifenacin treatment group.

Organic contamination of water bodies in which benthic microbial fuel cells (benthic MFCs) are installed, and organic crossover from the anode to the cathode of membraneless MFCs, is a factor causing oxygen depletion and substrate loss in the cathode due to the growth of heterotrophic aerobic bacteria. This study examines the possible use of silver nanoparticles (AgNPs) as a cathodic catalyst for MFCs suffering from organic contamination and oxygen depletion. Four treated cathodes (AgNPs-coated, Pt/C-coated, Pt/C+AgNPs-coated, and plain graphite cathodes) were prepared and tested under high levels of organics loading. During operation (fed with 50 mM acetate), the AgNPs-coated system showed the highest DO concentration (0.8 mg/L) in the cathode area as well as the highest current (ranging from 0.04 to 0.12 mA). Based on these results, we concluded that (1) the growth of oxygen-consuming heterotrophic microbes could be inhibited by AgNPs, (2) the function of AgNPs as a bacterial growth inhibitor resulted in a greater increase of DO concentration in the cathode than the other tested cathode systems, (3) AgNPs could be applied as a cathode catalyst for oxygen reduction, and as a result (4) the MFC with the AgNPs-coated cathode led to the highest current generation among the tested MFCs.

The microbial electrolysis cell (MEC) is a promising technology for producing biohydrogen at greater yield than with conventional technology. However, during a run of an acetate-fed MEC at an applied voltage of 0.5 V, substantial amounts of substrate are consumed in undesirable methanogenesis. Therefore, in order to suppress the methanogens specifically without adversely affecting exoelectrogens, this study examined the effects of sudden changes in pH, temperature and air-exposure, as well as chemical inhibitors, such as 2-bromoethanesulfonate (BES) and lumazine on methanogenesis. An abrupt decrease in temperature and pH from 30 to 20 °C and 7 to 4.9, respectively, had no effect on methanogenesis. Exposing the anode biofilm to air was also ineffective in inhibiting specific methanogens because both methanogens and exoelectrogens were damaged by oxygen. However, an injection of BES (286 μM) reduced the methanogenic electron losses substantially from 36.4 ± 4.4 (= 145.8 ± 17.4 μmol-CH 4 ) to 2.5 ± 0.3% (= 10.2 ± 1.2 μmol-CH 4 ), which in turn improved the overall hydrogen efficiency (acetate to H 2 ) from 56.1 ± 5.7 to 80.1 ± 6.5% (= 3.2 mol-H 2 /mol-acetate). Once after inhibited, the inhibitory influence was retained even after 10 batch cycles in the absence of further BES addition. In contrast to BES, methanogenesis was unaffected by lumazine, even at much higher concentrations. The installation of a Nafion membrane resulted in the production of high purity hydrogen at the cathode but hindered proton migration, which caused a serious pH imbalance between the anode and cathode compartments.

Purpose To analyze the baseline clinical factors and medication treatment strategy used in cases with medication treatment failure of benign prostatic hyperplasia (BPH). Methods From January 2006 to December 2009, 677 BPH patients with at least 3 months of treatment with medication were enrolled. We analyzed clinical factors by medication failure (n=161) versus maintenance (n=516), by prostate size (less than 30 g, n=231; 30 to 50 g, n=244; greater than 50 g, n=202), and by prostate-specific antigen (PSA) levels (less than 1.4 ng/mL, n=324; more than 1.4 ng/mL, n=353). Results Age, combination medication rate, PSA, and prostate volume were statistically different between the medication treatment failure and maintenance groups. By prostate size, the PSA and medication failure rates were relatively higher and the medication period was shorter in patients with a prostate size of more than 30 g. The combination medication rate was higher in patients with a prostate size of more than 50 g. The medication failure rate and prostate volume were higher in patients with a PSA level of more than 1.4 ng/mL. However, the combination treatment rate was not significantly different in patients with a PSA level lower than 1.4 ng/mL. Suggestive cutoffs for combination medication are a prostate volume of 34 g and PSA level of 1.9 ng/mL. Conclusions The clinical factors associated with medication failure were age, treatment type, and prostate volume. Combination therapy should be considered more in Korea in patients with a PSA level higher than 1.4 ng/mL and a prostate volume of between 30 and 50 g to prevent medication failure.

Objective: We carried out a nationwide epidemiological study to evaluate the prevalence and effect of varicoceles on testicular volume in South Korean adolescents. We also investigated the correlation between varicoceles and body mass index (BMI). Methods: In this prospective study, physical examinations were carried out to assess the presence and severity of varicoceles in middle school boys from six regions of South Korea. Testicular volume, height and weight of all boys were measured. The prevalence of varicoceles was assessed. The associations between age, testicular volume, BMI, and the presence and severity of varicoceles were examined. Results: A total of 1938 boys with a mean age of 14.1 years (range 13–16 years) were screened. A varicocele was found on the left side in 295 (15.2%) boys and on the right side in 8 (0.4%) boys. Bilateral varicoceles were found in 17 (0.9%) individuals. Of the subjects with a left varicocele, 151 (51.2%), 80 (27.1%) and 64 (25.1%) boys had a grade 1, 2 or 3 varicocele, respectively. The prevalence of varicoceles did not increase with age. The proportion of boys with testicular size discrepancies increased with the severity of the varicocele. After adjusting for age, BMI had a negative correlation with the presence of varicoceles. Conclusions: The prevalence of varicoceles in South Korean middle school boys is 16.5%. The presence of varicoceles seems to have a negative effect on testicular growth. BMI has a significant inverse relationship with the occurrence of varicoceles.

As the microbial fuel cell (MFC) technology is getting nearer to practical applications such as wastewater treatment, it is crucial to consider the different aspects that will make this technology viable in the future. In this paper, we provide information about the specifications of an energy self-sufficient MFC system as a basis to extrapolate on the potential benefits and limits of a future MFC-based wastewater treatment plant. We particularly emphasize on the importance of two crucial parameters that characterize an MFC: its electromotive force (E (emf)) and its internal resistance (R (int)). A numerical projection using state-of-art values (E (emf) = 0.8 V and R (int) = 5 Ω) emphasized on the difficulty at this moment to reach self-sufficiency using a reasonable number of MFCs at the laboratory scale. We found that a realistic number of MFCs to provide enough voltage (=5 V) at a sufficient current (=0.8 A) to power a pump requiring 4 W would be of 13 MFCs in series and 10 stacks of MFCs in parallel, resulting in a total number of 130 MFCs. That would result in a treatment capacity of 144 L of domestic wastewater (0.5 g-COD L(-1)) per day. The total MFC system would be characterized by an internal resistance of 6.5 Ω.

We report the electrochemical characterization and microbial community analysis of closed circuit microbial fuel cells (CC-MFCs) and open circuit (OC) cells continuously fed with propionate as substrate. Differences in power output between MFCs correlated with their polarization behavior, which is related to the maturation of the anodophilic communities. The microbial communities residing in the biofilm growing on the electrode, biofouled cation-exchange membrane and anodic chamber liquor of OC-and CC-MFCs were characterized by restriction fragment length polymorphism screening of 16S rRNA gene clone libraries. The results show that the CC-MFC anode was enriched in several microorganisms related to known electrochemically active and dissimilatory Fe(III) reducing bacteria, mostly from the Geobacter spp., to the detriment of Bacteroidetes abundant in the OC-MFC anode. The results also evidenced the lack of a specific pelagic community in the liquor sample. The biofilm growing on the cation-exchange membrane of the CC-MFC was found to be composed of a low-diversity community dominated by two microaerophilic species of the Achromobacter and Azovibrio genus., National Research Foundation (NRF) of the Korean government (MEST); United Nations University and Gwangju Institute of Science and Technology Joint Program

Aims: To assess the biodiversity of a large number of microbial fuel cell (MFC) anodes from a variety of MFC designs, all enriched with domestic wastewater, using a molecular fingerprinting method. Methods and Results: We optimized a protocol allowing the rapid characterization of MFC communities using terminal restriction fragment length polymorphism (T-RFLP) with two different sets of primers and a varying number of restriction enzymes. This protocol was further validated by direct comparison with bacterial clone libraries. Twenty-one MFC anodes were analysed by T-RFLP. We also provided a statistical comparison with other bacterial communities from environments sharing common features. Conclusions: Bacterial communities were dominated by β-Proteobacteria, mostly belonging to the Burkholderiales order, that are known to play an active role in the cycle of metals such as iron and manganese. This property may allow them to properly pass electrons to the anode of an MFC. Significance and Impact of the Study: Unlike other groups, β-Proteobacteria have seldom been acknowledged as potentially efficient electrochemically active bacteria (EAB) in MFCs. Yet, they are plentiful in natural environments like biocorrosion biofilms and acid mine drainages that consequently show some potential for MFC enrichment.

Our challenge in this study was to harvest electricity from organics coexisting in two different phases (water and sediment) in an organics-contaminated benthic environment and to obtain increased current using a multiphase electrode microbial fuel cell (multiphase MFC). The multiphase MFC consisted of a floating electrode (FE), a midelectrode (ME), and a sediment electrode (SE) with no other components. The SE was embedded in sediment; the FE and ME were then overlaid in the water surface layer and in the middle of the water column of an aquarium, respectively. During continuous supply of organics at a COD loading rate of 94 mg of COD L(-1) day(-1) and after the cessation of organics being supplied at COD loading rates of 330 and 188 mg of COD L(-1) day(-1), the multiphase MFC showed the highest current production, as compared to the control MFCs [a floating-type MFC (FT-MFC) and two types of sediment MFCs (SMFC-A and SMFC-B)]. The total charges (in coulombs) of the multiphase MFC integrated from the currents, obtained under the three operating conditions mentioned above, were comparable to the sums of charges for the FT-MFC and SMFC. As a result, this study found that the multiphase MFC can (1) utilize organics in the sediment similarly to SMFCs, (2) use organics in the water phase similarly to FT-MFCs, and (3) obtain increased current analogous to the sum of an SMFC and a FT-MFC. Thus, it is thought that the multiphase MFC developed in this work could be suitable for use in water bodies being continuously or frequently contaminated with organic waste.

An alternative method for determining the charge transfer resistance and double-layer capacitance of microbial fuel cells (MFCs), easily implemented without a potentiostat, was developed. A dynamic model with two parameters, the charge transfer resistance and double-layer capacitance of electrodes, was derived from a linear differential equation to depict the current generation with respect to activation overvoltage. This model was then used to fit the transient cell voltage response to the current step change during the continuous operation of a flat-plate type MFC fed with acetate. Variations of the charge transfer resistance and the capacitance value with respect to the MFC design conditions (biocatalyst existence and electrode area) and operating parameters (acetate concentration and buffer strength in the catholyte) were then determined to elucidate the validity of the proposed method. This model was able to describe the dynamic behavior of the MFC during current change in the activation loss region; having an R(2) value of over 0.99 in most tests. Variations of the charge transfer resistance value (thousands of Omega) according to the change of the design factors and operational factors were well-correlated with the corresponding MFC performances. However, though the capacitance values (approximately 0.02 F) reflected the expected trend according to the electrode area change and catalyst property, they did not show significant variation with changes in either the acetate concentration or buffer strength.

Hydrogen production with light as an additional energy source in a microbial electrolysis cell (MEC) is described. A ruthenium-dye (N719) sensitized solar cell with an open circuit potential (Voc) of 602 mV was connected to the MEC. Hydrogen production was carried out by irradiating the DSSC connected across the MEC with a light intensity of 40 mW/cm2 and also with natural sunlight. The DSSC was stable during various batch experiments. The acetate conversion efficiency and the coulombic efficiency based on the average of first two batches were 30.5 ± 2.5% and 40 ± 2% respectively. The cathodic recovery efficiency ranged from 72% to 86% during repeated batch experiments with an average of 78 ± 2.5%.

This paper reports successful hydrogen evolution using a dye-sensitized solar cell (DSSC)-powered microbial electrolysis cell (MEC) without a Pt catalyst on the cathode, indicating a solution for the inherent drawbacks of conventional MECs, such as the need for an external bias and catalyst. DSSCs fabricated by assembling a ruthenium dye-loaded TiO(2) film and platinized FTO glass with an I(-)/I(3)(-) redox couple were demonstrated as an alternative bias (V(oc) = 0.65 V). Pt-loaded (0.3 mg Pt/cm(2)) electrodes with a Pt/C nanopowder showed relatively faster hydrogen production than the Pt-free electrodes, particularly at lower voltages. However, once the applied photovoltage exceeded a certain level (0.7 V), platinum did not have any additional effect on hydrogen evolution in the solar-powered MECs: hydrogen conversion efficiency was almost comparable for either the plain (71.3-77.0%) or Pt-loaded carbon felt (79.3-82.0%) at >0.7 V. In particular, the carbon nanopowder-coated electrode without Pt showed significantly enhanced performance compared to the plain electrode, which indicates efficient electrohydrogenesis, even without Pt by enhancing the surface area. As the applied photovoltage was increased, anodic methanogenesis decreased gradually, resulting in increasing hydrogen yield.

Aims: To see the possibility of particle size distribution analyser (PSDA) in detecting concentration of lactobacillus contaminants in yeast fermentation. Methods and Results: A PSDA was used to rapidly determine the size and concentration of lactobacillus and Saccharomyces cerevisiae. Data showed that the aerodynamic diameters of Lactobacillus casei and S. cerevisiae cells were around 0·63 and 2·9 μm, respectively, with both cultures showing a linear relationship between cell density and particle count on a size distribution curve of PSDA. In addition, Lactobacillus fermentum showed high similarity in bacterial size distribution and particle count numbers with L. casei. The PSDA also rapidly detected (within 1 min) the cell concentrations of S. cerevisiae and L. casei in a mixed sample with different concentration ratios with 107–109 cells ml−1 of detection range. Conclusions: PSDA was demonstrated to be useful for the rapid detection of lactobacillus and S. cerevisiae concentrations. Significance and Impact of the Study: This is the first report concerning PSDA to detect the concentration of bacteria and yeast. This method can be useful in the actual field during ethanol fermentation because of relatively easy handling and rapid detection.

A microbiological process was established to harvest electricity from the carbon monoxide (CO). A CO fermenter was enriched with CO as the sole carbon source. The DGGE/DNA sequencing results showed that Acetobacterium spp. were enriched from the anaerobic digester fluid. After the fermenter was operated under continuous mode, the products were then continuously fed to the microbial fuel cell (MFC) to generate electricity. Even though the conversion yield was quite low, this study proved that synthesis gas (syn-gas) can be converted to electricity with the aid of microbes that do not possess the drawbacks of metal catalysts of conventional methods.

Biofoulants by autopsy of RO membrane and microbiological quality of the intake water were investigated with the samples obtained from existing RO desalination plant. The analysis of organic matters of the biofilm on the membrane surface showed that macromolecular substances such as proteins and carbohydrates were the major composites and contributed to the biofilm formation. Comparison of microbial communities between the RO membrane and seawater intake samples revealed that α-proteobacteria was the most abundant bacterial group both in the membrane surface and the intake water, and the phylum Firmicute and Planctomycetes, which were proposed not to be originated from the seawater intake, appeared as the potential biofoulants target. The final goal of this research project is to develop a rapid and sensitive biosensor system to detect the problematic biofoulants on RO system in seawater desalination process, with the tool of fluorescence nanoparticles. Preliminary result of this study showed that RO biofouling was contributed both by microbial cells and the extra organic substances and these identification and sensing of specific biofoulant targets will be beneficial to process efficiency.

Propionate was used as fuel to enrich an electrochemically-active microbial consortium in a microbial fuel cell, and the bacterial consortium was analyzed by culture-independent methods including denaturing gradient gel electrophoresis (DGGE) of the 16S rDNA, and by fluorescent in situ hybridization (FISH). MFCs fed with propionate produced a current of 4.88 +/- 0.1 mA stably on 100 mg propionate/l as COD within 3 weeks of the enrichment. When the MFCs were fed with H2-saturated fuel containing propionate, the current dropped to 3.82 +/- 0.07 mA. The maximum current generated was up to 8.8 mA when MFCs were fed with 200 mg propionate/l as COD. The DGGE of 16S rDNA showed that propionate- enriched MFCs have a different bacterial population from that enriched with acetate and from the inoculum used for enrichment. The major member (42%) of the consortium was an unidentified bacterium followed by c, b, and d-proteobacteria.

To reduce the pungency of Capsicum without the loss of its biological activity, a Capsicum sp. was fermented by Bacillus subtilis with the addition of Rapidase enzyme. At 1 day of fermentation, the capsaicin content of the Capsicum ferment with Rapidase had sharply decreased from an initial content of 11.8 to 2.8 microg/ml. The Rapidase-fermented Capsicum had higher total flavonoid and phenolic contents than the Capsicum ferment without Rapidase. In addition, ABTS radical scavenging activity was enhanced in the Rapidase-fermented Capsicum as compared to that without Rapidase. Overall, fermentation using B. subtilis and Rapidase was an efficient method to produce a non-pungent Capsicum with antioxidant properties.

In a two-electrode system, freshwater sediment was used as a fuel to examine the relationship between current generation and organic matter consumption with different types of electrode. Sediment microbial fuel cells using porous electrodes showed a superior performance in terms of generating current when compared with the use of non-porous electrodes. The maximum current densities with thicker and thin porous electrodes were 45.4 and 37.6 mA m(-2), respectively, whereas the value with non-porous electrodes was 13.9 mA m(-2). The amount of organic matter removed correlated with the current produced. The redox potential in the anode area under closed-circuit conditions was +246.3 +/- 67.7 mV, while that under open-circuit conditions only reached -143.0 +/- 7.18 mV. This suggests that an application of this system in organic-rich sediment could provide environmental benefits such as decreasing organic matter and prohibiting methane emission in conjunction with electricity production via an anaerobic oxidation process.

Background Worldwide restrictions in animal use for research have driven efforts to develop alternative methods. Objective The study aimed to test the efficacy of the macrophage inflammatory protein-1beta (MIP-1beta) assay for testing chemicals' skin-sensitizing capacity. Methods The assay was performed using 9 chemicals judged to be sensitizing and 7 non-sensitizing by the standard in vivo assays. THP-1 cells were cultured in the presence or absence of 4 doses, 0.01x, 0.1x, 0.5x, or 1x IC(50) (50% inhibitory concentration for THP-1 cell proliferation) of these chemicals for 24 hr, and the MIP-1beta level in the supernatants was determined. Skin sensitization by the test chemicals was determined by MIP-1beta production rates. The MIP-1beta production rate was expressed as the relative increase in MIP-1beta production in response to chemical treatment compared with vehicle treatment. Results and conclusion When the threshold MIP-1beta production rate used was 100% or 105% of dimethyl sulfoxide, all the sensitizing chemicals tested (dinitrochlorobenzene, hexyl cinnamic aldehyde, eugenol, hydroquinone, dinitrofluorobenzene, benzocaine, nickel, chromium, and 5-chloro-2-methyl-4-isothiazolin-3-one) were positive, and all the non-sensitizing chemicals (methyl salicylate, benzalkonium chloride, lactic acid, isopropanol, and salicylic acid), with the exception of sodium lauryl sulfate, were negative for MIP-1beta production. These results indicate that MIP-1beta could be a biomarker for classification of chemicals as sensitizers or non-sensitizers.

A new simple, rapid and sensitive high-performance anion-exchange chromatography method with pulsed amperometric detection (HPAEC-PAD) was developed and validated for the simultaneous determination of two Amadori compounds, arginyl-fructose and arginyl-fructosyl-glucose in Korean red ginseng (Panax ginseng) extracts, rat plasma. Separation of the two target analytes was efficiently undertaken on CarboPac PA1 anion-exchange column with isocratic elution (400 mM sodium hydroxide and deionized water (90:10, v/v)) at flow rate 0.7 mL/min within 15 min of single chromatographic run. Under optimized conditions, the detection limits (signal-to-noise ratio equal to 3) were 20 and 25 ng/mL for arginyl-fructose and arginyl-fructosyl-glucose, respectively. Calibration curves of peak area for the two analytes were linear over three orders of magnitude with a correlation coefficients greater than 0.999. The accuracy of the method was tested by recovery measurement of the spiked samples which yielded good results of 94.15-102.62%. This method was successfully applied to the quantification of arginyl-fructose and arginyl-fructosyl-glucose in herbal extracts and in the plasma samples from rat.

Data were obtained as meanvalue of 1/[V], inverse of the increase of optical density at 450 nm per min. (OD450/min), of three independent tests with differentconcentrations of L-tyrosine as a substrate. (A) with 100 μM (rectangle), 50 μM (triangle), 25 μM (circle), or no kojic acid (B) with 40 μM(rectangle), 20 μM (triangle), 10 μM (circle), or no compound

In this work, ammonia removal paths in microbial fuel cells (MFCs) under different initial pH conditions (pH 7.0, 8.0, and 8.6) were investigated. At a neutral pH condition (pH 7.0), MFC used an electrical energy of 27.4% and removed 23.3% of total ammonia by electrochemical pathway for 192h. At the identical pH condition, 36.1% of the total ammonia was also removed by the biological path suspected to be biological ammonia oxidation process (e.g., Anammox). With the initial pH increased, the electrochemical removal efficiency decreased to less than 5.0%, while the biological removal efficiency highly increased to 61.8%. In this study, a neutral pH should be maintained in the anode to utilize MFCs for ammonia recovery via electrochemical pathways from wastewater stream.

Micro-organisms were isolated from intake seawater and reverse osmosis (RO) membrane biofilms collected from a full-scale membrane-based desalination process. The results from a culture-dependent approach using 12 media were combined with the microbial community structure on fouled RO membranes as analyzed by a 16S rRNA clone library construction in our previous study. This was followed by selection of 11 target bacteria for further analysis, which were suspected to be responsible for biofilm formation on membrane surfaces. The adhesion of potential biofoulants differing in surface hydrophobicity and charge was examined. Cell wall hydrophobicity was measured as the contact angle of a lawn of bacteria, and by adhesion to hexadecane. The cell surface charge was investigated by measuring electrophoretic mobility. The data obtained from these methodologies were compared. According to the cell surface charge measurements, Pseudomonas aeruginosa, Acinetobacter venetianus, Cellvibrio mixtus subsp. Mixtus, Bacillus sp. Eur1 9.5, and Escherichia coli K12 could mediate initial adhesion to negatively charged RO membranes through electrostatic attraction. Limnobacter sp. KNF002, A. venetianus, and Simiduia agarivorans showed higher affinity to hexadecane than other bacterial strains tested, and Bacillus sp. Eur1 9.5, C. mixtus subsp. Mixtus, and P. aeruginosa were determined to have greater hydrophobic interactions with hydrophobic RO membranes. Refereed/Peer-reviewed

Micelle-to-vesicle transition method was used to make liposomes containing oleanolic acid. First, the solubilization of potassium salt of oleanolic acid at basic condition by micelle formation was confirmed. Using the soluble state of oleanolic acid at basic condition, liposomes containing oleanolic acid was prepared by adjusting pH. After making homogeneous aqueous mixture of potassium salt of oleanolic acid and lecithin in basic condition, the solution was neutralized to produce the lecithinbased liposomes that contain oleanolic acid inside the lipid bilayers. The optimal loading of oleanolic acid to lecithin (about 25 mole%) was found to exist to produce liposomal suspension of small size without homogenization step. Electron microscopy and dynamic light scattering studies showed that the narrowly distributed, reconstituted oleanolic acid-containing liposomes were prepared without severe mechanical treatment.

The purpose of this study is to investigate the optimum combination of polyols and oils in moisturizing cosmetic products to improve the human skin moisturization and skin surface roughness. Polyols and oils are essential ingredients in skin care products, but it is still not understood how their concentrations affect their efficacy and sensory properties on human skin. We investigated the effect of polyol and oil concentration on skin properties by noninvasive methods.The polyols consisted of glycerin and butylenes glycol in a ratio of 1:1 and the oils consisted of equal parts of hydrogenated polydecene, cethyl ethylhexanoate and pentaerythrityl tetraethylhexanoate. All cosmetic products were made in O/W emulsions in concentrations ranging from 0% to 30% for polyols and from 0% to 35% for oils. We investigated the effect on water content and skin surface roughness on the forearm after application of the cosmetic products. The skin water contents were measured by a Corneometer CM825 and the skin surface roughness by visual coring of skin surface biopsies in the scanning electron micrographs.In the first study, we found that the water content of the skin correlated highly with the polyol (up to 30%) and oil (up to 12%) concentrations, respectively. At two hours after application, the correlation coefficients were 0.971 and 0.985, respectively (P0.01). Skin surface roughness not only showed a strong concentration dependence on polyols and oils (up to 6%). In the second study, we investigated the optimum combination of polyols and oils to improve the skin moisturization and skin surface roughness by the Response surface methodology. The water content of the skin surface was high in the ratio of polyol to oil (30:12 and 25:30). The skin surface roughness was improved considerably in the ratio of polyols to oil (30:6 and 30:35).Our results indicated that the skin surface properties were improved in the different ratios of their concentrations because they are influenced by not one ingredient but the interaction between polyols and oils. In this study, we could recommend the optimum concentration of polyols and oils to improve the skin surface properties. Further studies will be performed with other ingredients such as surfactants, lipids and so on.

Proton exchange membranes (PEMs) are one of the most important components in microbial fuel cells (MFCs), since PEMs physically separate the anode and cathode compartments while allowing protons to transport to the cathode in order to sustain an electrical current. The Nafion 117 membrane used in this study is generally regarded as having excellent proton conductivity, though many problems for its application in MFCs remain. We investigated problems associated with Nafion including: oxygen leakage from cathode to anode, substrate loss, cation transport and accumulation rather than protons, and biofouling. It was found that Nafion was quite permeable to oxygen. The oxygen mass transfer coefficient (KO) and the oxygen diffusion coefficient (DO) for Nafion was estimated as KO = 2.80 × 10−4 cm/s and DO = 5.35 × 10−6 cm2/s, respectively when a 50 mM phosphate buffer was used as the catholyte. The MFC with distilled water instead of phosphate buffer showed similar values (KO = 2.77 × 10−4 cm/s, DO = 5.27 × 10−6...

Microbial fuel cells (MFCs) have been used to enrich microbes oxidizing formate with concomitant electricity generation. Medium containing formate was fed continuously to MFCs. MFCs showed approximately 1 mA of current after 4 months of operation. Over 90% of formate supplied was removed in MFCs, while Coulombic efficiency was only 5.3% indicating substantial electron and energy losses rather than electricity generation. Denaturing gradient gel electrophoresis (DGGE) showed that a formate-utilizing acetogenic bacterium (Acetobacterium sp.), an acetate-oxidizing metal reducer (Geobacter sp.), and another formate utilizer (Arcobacter sp.) were mainly detected on the electrode. This result indicates that some formate was consumed by acetogenic bacteria to make acetate, and acetate was used by acetate-utilizing electrochemically active bacteria (EAB) (e.g., Geobacter sp.). Additionally, formate was oxidized by nonelectrochemically active bacteria under microaerobic conditions in the anode compartment of the MFCs.

A microbial fuel cell (MFC) is a device that converts chemical energy into electricity through the catalytic activities of microorganisms. Although there is great potential of MFCs as an alternative energy source, novel wastewater treatment process, and biosensor for oxygen and pollutants, extensive optimization is required to exploit the maximum microbial potential. In this article, the main limiting factors of MFC operation are identified and suggestions are made to improve performance.

Electroplating wastewater (EW) containing heavy metals was treated by a two-stage packed-bed reactor system. The EW was highly contaminated with hexavalent chromium and other heavy metals as well as sulfate because sulfuric acid had been mainly used to polish the surface of metals to be electroplated. This acidic EW was effectively neutralized in an alkaline reactor where limestone had been packed. The neutralized wastewater together with organic wastewater from a starch-processing factory (SPW) was fed to a bioreactor packed with waste biomass. The SPW was used to supplement the electron donor in the sulfidogenic bioreactor. During the whole operation, we investigated the stoichiometry of electron to see what could be a major factor to remove Cr in the wastewater. The removal rates of sulfate and Cr(VI) were dependent on the consumption rate of organic materials in the wastewater. The stoichiometric studies also showed that about 63% of electrons from oxidation of organic materials were used to reduce sulfate. When the electrons of sulfide oxidation to elemental sulfur was at least 1.3 times higher than that of Cr(VI) reduction to Cr(III), Cr(VI) was completely removed. This result suggests that Cr(VI) reduction can be expected to take place under sulfate-rich anaerobic conditions, and sulfide produced by sulfate reducing bacteria could be used to immobilize soluble chromium through Cr(VI) reduction.

To improve lipase activity and make the particulate carrier for practical application, lipase was conjugated to chitosan(Mwavg=80,000) by immine reaction. The lipase activity of conjugate was 93% of its initial activity at room temperature for 7 months, whereas the intact lipase activity decreased to 40%. And then, lipase-chitosan conjugate was intercalated within porous silica. The composite was characterized by X-ray diffraction, scanning electron microscopy, thermo gravimetric analysis. The Pore size was regulated in the range of 5~15nm. The maximum enzyme activity of lipase-chitosan conjugate needs the structure with 15nm pore of mesoporous silica. The resultant composite was found to have the free flowing property and keep up inner lipase activity.

We measured proteasome activities and the levels of proteasome subunits in dermal fibroblasts from individuals aged 20-82 years. Proteasome activities changed with age in a biphasic manner, decreasing significantly up to 50 years of age and showing no significant change between 50 and 78 years of age. Similarly, proteasome activities in replicatively senescent dermal fibroblasts showed a passage-dependent biphasic change. We confirmed that the decreases in proteasome activities were accompanied by the accumulation of oxidized and ubiquitinated proteins. The decline in proteasome activities in aging fibroblasts was associated with a decrease in the expression of proteasome subunits. We found that the restoration of the normal level of proteasome catalytic subunits, using a lentivirus gene-delivery system, decreased the severity of the aging markers in dermal fibroblasts from elderly donors. These findings suggest that proteasome malfunction may contribute to the aging process in human skin and that the maintenance of normal proteasome activities could delay skin aging.

There are many cosmetic ingredients, such as preservatives and fragrances, known to elicit adverse effects. The aim of this study was to investigate the side-effects of cosmetic preservatives, by evaluating objective and subjective skin irritation. The method comprised of 2 parts. In part 1, we tried to compare 24-hr patch test results with the sensory irritation potential of several preservatives. In part 2, skin cumulative irritation test for 21 days and sensory irritation test were performed to compare various combinations of preservatives in 4 types of formulations. Our data showed that methylparaben, ethylparaben, propylparaben, butylparaben, phenoxyethanol (PE) and chlorphenesin (CPN) have similar objective skin irritation potential at the minimal inhibitory concentration of each preservative, but CPN has higher potential than other preservatives in subjective irritation. Sensory irritation of preservatives changed according to formulation type, and PE combined with CPN highly increased irritation. There was correlation between antimicrobial activity and skin objective irritation but not sensory irritation. Influence on skin sensory irritation varies with the combination of preservatives. Therefore, for the development of new preservatives and cosmetics, it is important to evaluate skin sensory irritation of preservatives used in cosmetic products according to the type of formulations.