Unipolar and bipolar electrogram characteristics of recurrent cases of idiopathic ventricular arrhythmias undergoing repeat catheter ablation.

INTRODUCTION: Activation mapping guided catheter ablation (CA) of ventricular arrhythmias (VAs) is limited in some cases when it is only relied on bipolar electrogram (EGM). We hypothesized that activation mapping with use of combined bipolar and unipolar EGM facilitates to identify the focal origin of VAs and results in reduction of recurrence rate of CA of VAs. METHODS: We analyzed the data of patients undergoing repeat ablations for idiopathic out-flow tract VAs. The EGM of the 1 st and 2 nd ablations were compared for earliest local activation time (LAT), presence of discrete potentials, and polarity reversal, unipolar potential morphology (QS or non-QS), potential amplitude and activation slope. RESULTS: Thirty-seven patients were included. The Local activation time was significantly earlier in the 2nd ablation as compared to the 1st procedure (36.90 msec vs 31.85 msec, P < 0.01). The incidence of discrete potentials and polarity reversal were similar in both procedures (51% vs 57%, P = 0.8 and 62% in both the occasions, respectively). The unipolar voltage was similar in both occasions (6.94 mV vs 7.22 mV in repeat ablations, P = 0.7). The recurrence rate (5.7%) was significantly lower with routine use of combined unipolar and bipolar EGMs, as compared to the use of bipolar EGM alone (16.7%) CONCLUSIONS: Use of both bipolar and unipolar electrograms helps in better delineation of the sites of earliest activation for effective ablation of VAs. Use of unipolar electrograms in addition to bipolar electrograms is associated with lower long term recurrence rate.

Evaluation of sex differences in the relationship between diastolic dysfunction and thromboembolism using propensity score analysis.

BACKGROUND: Female sex is a risk factor for thromboembolism (TE) in atrial fibrillation (AF); however, the underlying mechanisms are unclear. We postulated that left ventricular (LV) diastolic dysfunction (LVDD) could be associated with increased thromboembolic risk in women. METHODS: From a retrospective cohort, 158 patients (female : male = 79:79) with nonvalvular AF were propensity score-matched for age, presence of diabetes, hypertension, coronary artery disease, congestive heart failure, embolic history, AF type, and AF duration. Cardiac size and function and central aortic stiffness parameters were evaluated. Diastolic function was classified as normal, indeterminate, and LVDD according to recent guidelines. Surrogate markers for thromboembolism (dense spontaneous echo contrast and thrombus) were evaluated using transesophageal echocardiography. RESULTS: Surrogate markers for TE showed a trend to be more frequent in women than in men (21.5% vs 11.4%, P = .086). LVDD was more prevalent in women than in men (22.8% vs 2.5%, P < .001); however, the prevalence of indeterminate diastolic function was not different between sexes (26.6% vs 20.3%, P = .453). Surrogate markers for TE were detected mostly in women with LVDD. LV diastolic parameters showed a restrictive pattern, and aortic stiffness parameters were worse in women than in men. Women with LVDD had increased aortic stiffness compared to women with indeterminate and normal function, whereas aortic stiffness did not differ among men in all groups. Significant relations between LV diastolic function and aortic stiffness parameters were observed only in women. CONCLUSION: LVDD due to increased aortic stiffness could be related to a higher thromboembolic risk in women with AF.

Fate of preoperative atrial fibrillation after correction of atrial septal defect.

BACKGROUND: Atrial fibrillation (AF) is common among adult patients with an atrial septal defect (ASD). Catheter ablation or the Maze procedure can be considered for AF before or concurrently with ASD closure. However, the fate of preoperative AF is not well established. This study examined the postoperative course of patients with AF before undergoing ASD correction. METHODS AND RESULTS: The 471 patients (131 men, 42 ± 14 years) underwent transcatheter closure (n=237, 50%) or surgical repair (n=234, 50%) of an ASD. ECG and Holter monitoring were used to document preoperative and postoperative AF. Forty patients had AF before transcatheter closure (n=10) or surgical repair (n=30) of the ASD. During the follow-up period of 44 ± 28 months, excluding 15 patients who had undergone surgical repair with the Maze procedure, sinus rhythm (SR) was maintained in 7 (88%) of 8 patients with paroxysmal AF. However, only 3 (18%) of 17 patients with persistent AF maintained SR. Among the 15 patients treated with the Maze procedure, 12 (80%) maintained SR. CONCLUSIONS: Hemodynamic correction of ASD was effective in conversion to SR in most patients with preoperative paroxysmal AF. However, the Maze procedure or transcatheter ablation before ASD correction needs to be considered for the treatment of AF in patients with persistent AF.

The electroanatomical remodelling of the left atrium is related to CHADS2/CHA2DS2VASc score and events of stroke in patients with atrial fibrillation.

BACKGROUND: Although atrial fibrillation (AF) increases the risk of stroke, its relationship with atrial remodelling has not yet been studied. We hypothesized that the degree of electroanatomical remodelling of the left atrium (LA) is related to CHADS2/CHA2DS2VASc score and events of stroke. METHODS AND RESULTS: We compared CHADS2/CHA2DS2VASc score (0, 1, ≥ 2) or events of stroke with mean and regional LA volume [by three-dimensional (3D) computed tomography images] or LA endocardial voltage (by 3D-electroanatomical map) in 348 patients who underwent catheter ablation of AF (78.4% male, 55.4 ± 11.0 years old, paroxysmal AF:persistent AF = 215:133). We graded LA volume index as Grade 1 (< 48.3 mL/m²; n= 80), grade 2 (48.3-63.0 mL/m², n= 82), grade 3 (63.0-99.0 mL/m²; n= 94), and grade 4 (≥ 99.0 mL/m²; n= 92). Results (i) The percentage volume of anterior portion of LA enlarged at the early stage of LA remodelling (Grade 1 vs. grade 2, P= 0.006) and the voltage of posterior venous LA was significantly reduced with the degree of LA remodelling (P= 0.001). (ii) Mean LA volume/body surface area (BSA), especially anterior portion of LA, was greater in patients with high CHADS2/CHA2DS2VASc score (P= 0.002). Mean LA voltage was significantly lower in patients with high CHA2DS2VASc score than low score (P= 0.007). (iii) In patients who experience stroke (n= 22), LA volume/BSA, especially anterior LA, was greater (P= 0.012), and LA endocardial voltage was lower (P= 0.039) than those without stroke. CONCLUSION: Electroanatomical remodelling of LA, estimated by LA volume and endocardial voltage, has significant relationship with the risk scores or events of stroke in patients with non-valvular AF.

Intracoronary thrombus formation after drug-eluting stents implantation: optical coherence tomographic study.

BACKGROUND: Intracoronary thrombus formation after drug-eluting stent (DES) implantation is not sufficiently evaluated. METHODS: Optical coherence tomography (OCT) was performed in 226 patients (total DES n = 244, sirolimus-eluting stent [SES] n = 95, paclitaxel-eluting stent [PES] n = 62, zotarolimus-eluting stent [ZES] n = 87) after implantation (mean 11 months, range 3-66 months). Using OCT, we investigated the incidence and determinants of intracoronary thrombus. RESULTS: Intracoronary thrombus was detected in 35 (14%) cases (27 SES [28%], 7 PES [11%], and 1 ZES [1%], P < .001) and was associated with longer stent, smaller stent diameter, and stents at bifurcation lesions. More uncovered stent struts (26 +/- 23 vs 8 +/- 17, P < .001) and malapposed stent struts (6 +/- 14 vs 2 +/- 6, P < .001) were also associated with intracoronary thrombus. Multiple logistic regression analysis found the following determinants of intracoronary thrombus: stent length > or =28 mm (odds ratio [OR] 7.31, 95% CI 1.79-29.86, P = .01), stent diameter <3.0 mm (OR 4.38, 95% CI 1.38-13.97, P = .01), and > or =8 uncovered struts in each stent (OR 3.29, 95% CI 1.07-10.17, P = .04). CONCLUSIONS: Length, size, and types of DES may be more important than clinical factors in intracoronary thrombus formation after DES implantations.

A new stent design for the treatment of true bifurcation lesions: H-side branch stents.

BACKGROUND: There has been much debate for the adequate treatment strategies for true bifurcation lesions. The purpose of this study is to introduce and test a novel stent design for the treatment of true bifurcation lesions. METHODS: This side branch stent is composed of three parts: proximal, connecting, and distal parts. The distal part for the side branch vessel has a slope-side stent margin for circumferential coverage of the ostium and one radio-opaque marker for targeting the carina. The proximal part with two radio-opaque markers operates for safe stent delivery and useful guidance for a more precise placement of the distal part on the side branch ostium. Results of the in vitro test in the acrylic resin-made bifurcation phantom model were evaluated with microcomputer tomography. Animal experiments with this new stent platform were also performed in five pigs. RESULTS: In vitro test and microcomputer tomography showed complete coverage of the side branch ostium circumferentially with stent struts, and the absence of stent struts in the main vessel above the side branch ostium level. This side branch stents were successfully deployed in all 5 pigs. The results of animal experiments were also similar to those of in vitro tests. CONCLUSIONS: In vivo and vitro tests demonstrated the effective modality of this side branch stent for the treatment of true bifurcation lesions.

Relationship between multiple plasma biomarkers and vulnerable plaque determined by virtual histology intravascular ultrasound.

BACKGROUND: The relationship between plasma biomarkers and vulnerable plaque is not well understood. METHODS AND RESULTS: The 188 patients who underwent 3-vessel virtual histology (VH) intravascular ultrasound (IVUS) with peripheral blood sampling were enrolled. Plasma levels of matrix metalloproteinase 2 and 9 (MMP-2, -9), tissue inhibitor of metalloproteinase-1, adiponectin, and macrophage migration inhibitory factor were measured. VH-IVUS-derived thin cap fibroatheroma (VH-TCFA) was defined as a necrotic core >10% of plaque area in the presence of >40% plaque burden. There were 38 patients with ruptured plaque and 150 patients without (107 patients with VH-TCFA, 43 patients without VH-TCFA) in culprit/target lesions. Among the biomarkers, only the MMP-9 level was significantly higher in patients with ruptured plaque (P=0.002). In the subgroup without ruptured plaque, significant differences in the levels of several biomarkers were not observed between patients with and without VH-TCFA. In both culprit/target and nonculprit/non-target vessels, the MMP-9 level showed a weak correlation with the total number of ruptured plaques (r=0.231, P=0.002). CONCLUSIONS: Among the biomarkers tested in this study, the MMP-9 level was significantly higher in patients with ruptured plaque. However, measurement of several biomarkers, including MMP-9, was incapable of predicting the presence of VH-TCFA.

Enhanced alcohol degradation and hepatic protective effects of an Acetobacter Pasteurianus-derived product, CureZyme-ACE, in an acute intoxication rat model.

Excessive alcohol consumption induces acute intoxication and various hepatic diseases. In this study, we investigated the effect of the CureZyme-ACE (CA), Acetobacter Pasteurianus (AP)-derived product, in acute intoxication rats. The ethanol and acetaldehyde levels of serum were lower in rats treated with CA than those who only treated ethanol. The activities of alcohol dehydrogenase and acetaldehyde dehydrogenase also recovered faster in the CA group than only-ethanol group. The transaminase levels (AST, ALT) in the CA group were significantly lower than only-ethanol group. In addition, Hepatic histological analyses and stomach wall were demonstrated that the CA-treated group recovered faster than only-ethanol group. With regard to most characteristics, we found that CA had dose-dependent effects. At high concentrations of CA, there were no differences in the tested parameters compared to those of normal rats. These findings indicate that CA reduces the serum alcohol concentration and some of the hepatic damage caused by alcohol intoxication.

Rescue Extracorporeal Bypass to Prevent Atrioesophageal Fistula-related Air Embolism.

Atrioesophageal fistula (AEF) is a rare but disastrous complication encountered after radiofrequency catheter ablation for atrial fibrillation or flutter. Furthermore cerebral air embolism due to AEF is considered a strong predictor of mortality. In our case a patient presented with AEF and cerebral air embolism. As a rescue effort ventricular fibrillation was induced and sustained under venoarterial extracorporeal membrane oxygenation support until emergency AEF repair was feasible. Herein we report the successful use of the above measures to prevent further air embolism in a patient with radiofrequency catheter ablation-related AEF.

Two women presenting aborted sudden cardiac arrest as the first event of mitral valve disease

Mitral valve prolapse (MVP) is a relatively common valvular heart disease and is known to have a benign course. However, a certain subtype of MVP has a pathologic prognosis and can be accompanied by malignant cardiac arrhythmia causing sudden cardiac arrest, which can be characterized by bileaflet mitral valvular thickening and prolapse and frequent premature ventricular ectopic activity upon electrocardiography. Herein, we present two patients with bileaflet mitral prolapse who survived aborted sudden cardiac arrest. These cases show a precise MVP diagnosis that may prevent a devastating life event with the unique MVP subtype.

Rationale, design, and endpoints of the 'DEvice-Detected CArdiac Tachyarrhythmic Events and Sleep-disordered Breathing (DEDiCATES)' study: Prospective multicenter observational study of device-detected tachyarrhythmia and sleep-disordered breathing.

BACKGROUND: Few studies have investigated the prognostic value of cardiac implantable electronic device (CIED)-detection of sleep-disordered breathing (SDB) for risk stratification of cardiovascular events. In the Device-Detected CArdiac Tachyarrhythmic events and Sleep-disordered breathing (DEDiCATES) study, we aim to determine whether device-detected SDB events are associated with increased risk of cardiac arrhythmias or other cardiovascular outcomes. METHODS AND DESIGN: Six-hundred patients (300 patients with low-voltage pacing devices and 300 with high-voltage defibrillator devices) who have dual chamber CIEDs with AP Scan™ function (Boston Scientific Inc., Marlborough, MA, USA) are planned to be enrolled in this study. AP Scan reports the average number of sleep disturbance events per hour per night in the form of a Respiratory Disturbance Index (RDI). The daily RDI values are to be used for quantitative measurement of the severity and burden of SDB. CIED-detected atrial high rate episodes (AHREs) and clinical atrial tachyarrhythmia will be assessed as the primary outcomes over a follow-up period of 2 years. Correlations between CIED-detected SDB and AHRE burdens will be analyzed. The secondary outcomes are CIED-detected or clinical ventricular arrhythmic events, stroke, heart failure hospitalization, mortality, and quality of life. CONCLUSION: This study will determine the prognostic value of automated diagnostic function of CIED for SDB, which will help to improve the cardiovascular prognoses of CIED patients by enabling convenient and accurate assessments of SDB events.

Properties of Kimchi Fermented with GABA-Producing Lactic Acid Bacteria as a Starter.

Kimchi (a traditional Korean fermented vegetable) was prepared with a starter, Lactobacillus zymae GU240 producing γ-aminobutyric acid (GABA), and one precursor of GABA (glutamic acid, glutamic acid monosodium salt (MSG), or kelp extract). L. zymae GU240, an isolate from kimchi, can grow at 7% NaCl and low temperature. Five different kimchi samples were fermented for 20 weeks at -1°C. Kimchi with starter alone could not produce GABA. The GABA content was highest in kimchi with co-inoculation of the starter and MSG (1% (w/w)). Kimchi co-inoculated with the starter and kelp extract powder (3% (w/w)) had the second highest GABA content. Addition of glutamic acid powder (1% (w/w)) caused a reduction in the pH level of kimchi and growth inhibition of lactic acid bacteria and yeasts. Kimchi samples with MSG or kelp extract showed improvement of sensory evaluation scores. The results demonstrate the possibility to produce kimchi with improved functionality and taste by using L. zymae GU240 as a starter along with a suitable precursor such as MSG or kelp extract.

Effects of different types of salts on the growth of lactic acid bacteria and yeasts during kimchi fermentation.

Kimchi was prepared with different types of salts: purified salt (PS), solar salt aged for 1 year (SS1), aged for 3 years (SS3), and bamboo salt (BS). Kimchi inoculated with Leuconostoc mesenteroides P30 (starter kimchi), and control kimchi (non-starter kimchi) were prepared, and stored at - 1 °C for 20 weeks. Titratable acidity values increased slowly and reached 0.96-1.01% (pH 3.73-3.83) at 20 weeks. Proportions of coccus-type lactic acid bacteria (LAB) among total LAB were higher in SS kimchi than PS kimchi. Among non-starter kimchi, the proportions were 44.7, 41.6, 29.7, and 32.1% for SS3, SS1, BS, and PS kimchi, respectively, at 2 weeks, and 11.5, 12.8, 6.7, and 5.8%, respectively, at 20 weeks. SS kimchi had much less yeast counts than PS kimchi. Among starter kimchi, yeasts were detected from PS kimchi at 10 weeks but not detected until 18 weeks from SS1 and BS kimchi and 20 weeks from SS3 kimchi.

Microbial Communities and Physicochemical Properties of Myeolchi Jeotgal (Anchovy Jeotgal) Prepared with Different Types of Salts.

Myeolchi jeotgals (MJs) were prepared with purified salt (PS), solar salt aged for 1 year (SS), and bamboo salt (BS) melted 3 times at 10% and 20% (w/w) concentrations, and fermented for 28 weeks at 15°C. BS MJ showed higher pH and lower titratable acidities than the other samples because of the alkalinity of bamboo salt. Lactic acid bacteria counts increased until 4-6 weeks and then decreased gradually, and were not detected after 20 weeks from MJs with 10% salt. Yeast counts of PS MJs were higher than those of BS and SS MJs. Bacilli were detected in relatively higher numbers throughout the 28 weeks, like marine bacteria, but archae were detected in lower numbers during the first 10 weeks. When 16S rRNA genes were amplified from total DNA from PS MJ (10% salt) at 12 weeks, Tetragenococcus halophilus was the major species. However, Staphylococcus epidermidis was the dominant species for BS MJ at the same time point. In SS MJ, T. halophilus was the dominant species and S. epidermidis was the next dominant species. BS and SS MJs showed higher amino-type nitrogen, ammonia-type nitrogen, and volatile basic nitrogen contents than PS MJs. SS and BS were better than PS for the production of high-quality MJs.

Characterization of a Glutamate Decarboxylase (GAD) from Enterococcus avium M5 Isolated from Jeotgal, a Korean Fermented Seafood.

To develop starters for the production of functional foods or materials, lactic acid bacteria producing γ-aminobutyric acid (GABA) were screened from jeotgals, Korean fermented seafoods. One isolate producing a high amount of GABA from monosodium L-glutamate (MSG) was identified as Enterococcus avium by 16S rRNA gene sequencing. E. avium M5 produced 18.47 ± 1.26 mg/ml GABA when incubated for 48 h at 37°C in MRS broth with MSG (3% (w/v)). A gadB gene encoding glutamate decarboxylase (GAD) was cloned and overexpressed in E. coli BL21 (DE3) using the pET26b (+) expression vector. Recombinant GAD was purified through a Ni-NTA column and the size was estimated to be 53 kDa by SDS-PAGE. Maximum GAD activity was observed at pH 4.5 and 55°C and the activity was dependent on pyridoxal 5'-phosphate. The Km and Vmax values of GAD were 3.26 ± 0.21 mM and 0.0120 ± 0.0001 mM/min, respectively, when MSG was used as a substrate. Enterococcus avium M5 secretes a lot of GABA when grown on MRS with MSG, and the strain is useful for the production of fermented foods containing a high amount of GABA.

Properties of a Fibrinolytic Enzyme Secreted by Bacillus amyloliquefaciens RSB34, Isolated from Doenjang.

Nine bacilli with fibrinolytic activities were isolated from doenjang, a traditional Korean fermented soy food. Among them, RSB34 showed the strongest activity and was identified as Bacillus amyloliquefaciens by 16S rRNA and recA gene sequencing. During growth on LB up to 96 h, RSB34 showed the highest fibrinolytic activity (83.23 mU/µl) at 48 h. Three bands of 23, 27, and 42 kDa in size were observed when the culture supernatant was analyzed by SDS-PAGE and 27 and 42 kDa bands by fibrin zymography. The gene encoding the 27 kDa fibrinolytic enzyme AprE34 was cloned by PCR. BLAST analyses confirmed that the gene was a homolog to genes encoding AprE-type proteases. aprE34 was overexpressed in Escherichia coli BL21(DE3) using pET26b(+). Recombinant AprE34 was purified and examined for its properties. The Km and Vmax values of recombinant AprE34 were 0.131 ± 0.026 mM and 16.551 ± 0.316 µM/l/min, respectively, when measured using an artificial substrate, N-succinyl-ala-ala-pro-phe-p-nitroanilide. aprE34 was overexpressed in B. subtilis WB600 using pHY300PLK. B. subtilis transformants harboring pHYRSB34 (pHY300PLK with aprE34) showed higher fibrinolytic activity than B. amyloliquefaciens RSB34.

Value of adenosine test to reveal dormant conduction or adenosine-induced atrial fibrillation after pulmonary vein isolation.

BACKGROUND: Recent studies investigating the implications of additional ablation guided by dormant pulmonary vein (PV) conduction testing using adenosine showed conflicting results, and the data about atrial fibrillation (AF) recurrence after trigger site elimination in adenosine-induced AF are still lacking. METHODS: Of 846 patients with paroxysmal AF (PAF) who underwent PV isolation (PVI), adenosine test after PVI was performed in 148 patients. RESULTS: PVI was successfully achieved in 846 patients. We excluded 58 patients due to loss to the follow-up. A higher rate of AF recurrence was found in the group without adenosine test (136/644, 21%) compared to the group with adenosine test (20/144, 13%, log-rank P=0.047). In multivariate analysis model for AF freedom during the follow-up period, the only significant clinical predictor of AF freedom was adenosine test (hazard ratio [HR] 1.97; 95% confidence interval [CI]: 1.2-3.23; P=0.007).Among 148 patients with adenosine test, 114 (77%) patients showed neither dormant conductions nor AF-induced, 22 (15%) showed positive dormant conductions only, and 12 (8%) revealed adenosine-induced AF (6 of them also showed dormant conduction). After additional ablation in positive dormant conduction group and adenosine-induced AF group, AF recurrence was noted in 4/21 (19%) patients in positive dormant conduction group and 2/11 (18%) patients in adenosine-induced AF group, which was not different from that of patients in negative dormant conduction/ no AF-induced group (14/112, 12%, log-rank P=0.67). CONCLUSIONS: Adenosine test after PVI to confirm the absence of dormant conduction and triggers initiating AF is beneficial to improve the outcomes after catheter ablation of PAF.

Effects of Different Salt Treatments on the Fermentation Metabolites and Bacterial Profiles of Kimchi.

The effects of purified salt (PS) and mineral-rich sea salt (MRS), both with different mineral profiles, on kimchi fermentation were studied using a culture-dependent 16S rRNA sequencing technique and mass-based metabolomic analysis. The different mineral profiles in the fermentation medium caused changes in the bacterial profiles of the 2 kimchi products. An increase of Leuconostoc species in MRS-kimchi decreased the Lactobacillus/Leuconostoc ratio, which led to changes in metabolites (including sugars, amino acids, organic acids, lipids, sulfur compounds, and terpenoids) associated with kimchi quality. Although further studies on the relationship between these salt types and kimchi fermentation are needed, these results suggested that the MRS treatment had positively affected the changes of the kimchi mineral contents, bacterial growth, and metabolite profiles, which are linked to kimchi quality.

Properties of Doenjang (Soybean Paste) Prepared with Different Types of Salts.

Samples of doenjang (a fermented soybean paste) were prepared with different types of salts; purified salt (PS), 3-year-aged solar salt (SS3), 1-year-aged solar salt (SS1), and bamboo salt (BS, 3(rd) processing product). For starter doenjang samples, selected starters comprising two bacilli, one yeast, and one fungus were inoculated, whereas for non-starter doenjang samples, microorganisms present in rice straw were inoculated after enrichment. The doenjang samples were fermented for 13 weeks at 25°C. During the fermentation period, SS and BS doenjang samples showed higher bacilli counts as well as much lower yeast counts than PS doenjang. At 13 weeks, yeast counts of starter doenjang samples were 7.75, 5.69, 6.08, and 4.74 log CFU/g for PS, SS3, SS1, and BS doenjang, respectively. For non-starter doenjang samples, counts were 7.17, 5.05, 5.92, and 4.54 log CFU/g for PS, SS3, SS1, and BS doenjang, respectively. SS and BS promoted growth of bacilli but inhibited growth of yeasts compared with PS. Debaryomyces hansenii was the dominant yeast in PS doenjang, whereas Candida guilliermondii and Pichia sorbitophila were dominant in SS and BS doenjang. In the sensory evaluation, SS and BS doenjang scored better than PS doenjang. In conclusion, SS and BS seem better than PS for production of high-quality doenjang.

Antimicrobial activity of Bacillus amyloliquefaciens EMD17 isolated from Cheonggukjang and potential use as a starter for fermented soy foods.

A Bacillus strain with antimicrobial activity was isolated from Cheonggukjang and identified as Bacillus amyloliquefaciens. Filtered culture supernatants of B. amyloliquefaciens EMD17 strongly inhibited growth of Bacillus cereus ATCC14579, Listeria monocytogenes ATCC19111, and an ochratoxin (OTA) producing Penicillium spp. The antimicrobial activity was not decreased by heat, pH, and proteases treatment, indicating a non-proteinous nature of the antimicrobial substance. A B. amyloliquefaciens EMD17 culture added to a B. cereus ATCC14579 culture killed B. cereus cells completely in 6 h, showing the bacteriocidal effect. The srfAA gene encoding surfactin synthetase A was detected using PCR, indicating that surfactin might be the responsible agent. Genes encoding fengycin and iturin were also detected. MS indicated production of lipopeptides, including surfactin. Cheonggukjang and Doenjang were prepared using B. amyloliquefaciens EMD17 as a starter and growth of spiked B. cereus cells was completely inhibited.