Traditional Korean Fermented Seafood Research Articles

Sporosarcina jeotgali sp. nov., Sporosarcina oncorhynchi sp. nov., and Sporosarcina trichiuri sp. nov., Isolated from Jeotgal, a Traditional Korean Fermented Seafood.

Three novel, Gram-stain-positive, obligate aerobic, catalase- and oxidase-positive bacterial strains, designated B2O-1T, T2O-4T, and 0.2-SM1T-5T, were isolated from jeotgal, a traditional Korean fermented seafood. Strains B2O-1T, T2O-4T, and 0.2-SM1T-5T exhibited distinct colony colors, characterized by pink, yellow, and red opaque circular colonies, respectively. Phylogenetic analysis revealed that three strains formed a paraphyletic clade within the genus Sporosarcina and shared < 99.0% similarity with Sporosarcina aquimarina KCTC 3840T and Sporosarcina saromensis KCTC 13119T in their 16S rRNA gene sequences. The three strains exhibiting Orthologous Average Nucleotide Identity values < 79.3% and digital DNA-DNA hybridization values < 23.1% within the genus Sporosarcina affirmed their distinctiveness. Strains B2O-1T, T2O-4T, and 0.2-SM1T-5T contained MK-7 as a sole respiratory menaquinone and A4α type peptidoglycan based on lysine with alanine, glutamic acid, and aspartic acid. The common polar lipids include diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine. Strain T2O-4T contained one unidentified phospholipid, whereas strain 0.2-SM1T-5T contained two unidentified phospholipids. Cellular fatty acid profiles, with C15:0 anteiso as the major fatty acid, supported the affiliation of the three strains to the genus Sporosarcina. Based on the polyphasic characteristics, strains B2O-1T (= KCTC 43506T = JCM 36032T), T2O-4T (= KCTC 43489T = JCM 36031T), and 0.2-SM1T-5T (= KCTC 43519T = JCM 36034T) represent three novel species within the genus Sporosarcina, named Sporosarcina jeotgali sp. nov., Sporosarcina oncorhynchi sp. nov., and Sporosarcina trichiuri sp. nov., respectively.

Potential application of lactic acid bacteria for controlling discoloration in tuna (Thunnus orientalis)

Pacific bluefin tuna (Thunnus orientalis) is a highly valued seafood consumed globally. The red color of tuna meat is considered a crucial indicator of its freshness and value, influencing consumer purchasing decisions. Therefore, the present study aimed to investigate the effect of lactic acid bacteria (LAB) isolated from traditional Korean fermented seafood (jeotgal) on preventing the discoloration of tuna meat during storage. Thirty-six strains of LAB (M1–M36) were isolated and examined for superior antioxidant and metmyoglobin conversion activities. Two strains, M1 (Lactococcus lactics) and M8 (Leuconostoc citreum), were selected. Subsequently, the tuna meat was treated with the cell-free supernatant (CFS) of the selected LAB strains and stored at 4 °C. Treatment with CFS maintained a significantly high level of redness (a*) in the tuna meat for up to 48 h; furthermore, this tendency was consistent with the relative quantification of myoglobin derivatives. The oxymyoglobin content in CFS-treated tuna meat remained above 60% for up to 60 h. Conversely, the metmyoglobin content in the untreated group reached over 60% only after 48 h, resulting in complete discoloration. Conclusively, this study demonstrated that LAB-CFS can prevent tuna meat discoloration during refrigerated storage, indicating its potential for maintaining the quality and color of tuna meat.

Immune-enhancing effects of postbiotic produced by Bacillus velezensis Kh2-2 isolated from Korea Foods

Postbiotics defined as soluble factors (products or metabolic byproducts) that are released after bacterial lysis or secreted by live bacteria, have attracted considerable attention because of their long shelf life, safety, and beneficial effects. In this study, we investigated the immune-enhancing activities of squid jeotgal (a traditional Korean fermented seafood)-derived Bacillus velezensis Kh2-2 (Kh2-2) postbiotics in vitro, ex vivo, and in vivo. Cell lysates of four Bacillus species were prepared by sonication. In particular, Kh2-2 lysates induced NO production by upregulating iNOS expression in RAW264.7 cells compared with the lysates of B. subtilis Kh2-1, B. vallismortis Kh8-3, and B. amyloliquefaciens Kh3-1. Furthermore, Kh2-2 lysates stimulated immune activation of macrophages by upregulating the NF-κB and MAPK signaling pathways and promoting immune-related cytokine secretion. In the ex vivo study, Kh2-2 lysates stimulated proliferation and polarized Th1 response by inducing the production of IL-2 and IFN-γ and inhibiting IL-10 expression in splenocytes. The in vivo immune-enhancing effects of Kh2-2 lysates and Kh2-2 were further evaluated using a cyclophosphamide (CTX)-induced immunosuppression mouse model. The results showed that oral administration of Kh2-2 lysates improved CTX-induced immunosuppression by enhancing innate and adaptive immunity, stimulating immune-related cytokine secretion, and modulating gut microbiota dysbiosis in mice. Thus, we concluded that Kh2-2 lysates have potential as a functional material for postbiotics with immune-enhancing effects.

Characterization of a salt-resistant fibrinolytic protease of Bacillus licheniformis HJ4 isolated from Hwangseokae jeotgal, a traditional Korean fermented seafood.

Bacillus licheniformis HJ4 showing strong fibrinolytic activity was isolated from Hwangseokae jeotgal. aprEHJ4, a major fibrinolytic gene, was cloned by PCR, and an ORF consisting of 379 amino acids was located. The mature enzyme was expected to be 27kDa in size after processing, but a 24-kDa protein was observed by SDS-PAGE and fibrin zymography, indicating additional processing. RT-qPCR showed that expression level of aprEHJ4 in culture with 0% salt (control) was the highest followed by culture with 8% salt (89.7% of control) and 5% salt (74.2%) at 84h. The expression level in culture with 15% salt was 46.9%. The results matched with the fibrinolytic activity measurements of cultures and indicated that AprEHJ4 maintained significant activity in the presence of salt up to 15% (w/v). AprEHJ4 was overproduced in Escherichia coli, and mature 27kDa protein was purified after in vitro renaturation. The optimum pH and temperature of AprEHJ4 were pH 8 and 40 ℃, respectively.

Characterization of a Fibrinolytic Enzyme Secreted by Bacillus velezensis BS2 Isolated from Sea Squirt Jeotgal.

Bacillus sp. BS2 showing strong fibrinolytic activity was isolated from sea squirt (munggae) jeotgal, a traditional Korean fermented seafood. BS2 was identified as B. velezensis by molecular biological methods.B. velezensis BS2 grows well at 15% NaCl and at 10oC. When B. velezensis BS2 was cultivated in TSB broth for 96 h at 37°C, the culture showed the highest fibrinolytic activity (131.15 mU/µl) at 96 h. Three bands of 27, 35 and 60 kDa were observed from culture supernatant by SDS-PAGE, and fibrin zymography showed that the major fibrinolytic protein was the 27 kDa band. The gene (aprEBS2) encoding the major fibrinolytic protein was cloned, and overexpressed in heterologous hosts, B. subtilis WB600 and E. coli BL21 (DE3). B. subtilis transformant showed 1.5-fold higher fibrinolytic activity than B. velezensis BS2. Overproduced AprEBS2 in E. coli was purified by affinity chromatography. The optimum pH and temperature were pH 8.0 and 37°C, respectively. Km and Vmax were 0.15 mM and 39.68 µM/l/min, respectively, when N-succinyl-Ala-Ala-Pro-Phe-pNA was used as the substrate. AprEBS2 has strong α-fibrinogenase and moderate β-fibrinogenase activity. Considering its high fibrinolytic activity, significant salt tolerance, and ability to grow at 10°C, B. velezensis BS2 can be used as a starter for jeotgal.

김치 저장 중 N-Nitrosodimethylamine 생성에 젓갈의 함량과 종류의 영향

김치 저장 중 N-Nitrosodimethylamine 생성에 젓갈의 함량과 종류의 영향

Proteus cibarius sp. nov., a swarming bacterium from Jeotgal, a traditional Korean fermented seafood, and emended description of the genus Proteus.

A novel Proteus-like, Gram-stain-negative, facultatively anaerobic, rod-shaped bacterium, designated strain JS9T, was isolated from Korean fermented seafood, Jeotgal. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain JS9T belonged to the genus Proteus in the family Enterobacteriaceae. The highest 16S rRNA gene sequence similarity of strain JS9T was to Proteus vulgaris KCTC 2579T (98.98 %) and the genomic DNA G+C content is 39.0 mol%. DNA-DNA hybridization values were measured and strain JS9T showed <20.8 % genomic relatedness with closely-related members of the genus Proteus. The isolate showed bacterial motility and swarming activity similar to those of pathogenic Proteus mirabilis but distinct from those of other species of the genus Proteus. The isolate grows optimally at 30 °C, at pH 7, and in the presence of 2 % (w/v) NaCl. The main respiratory quinones are ubiquinone Q-8 and Q-10, and the major cellular fatty acids are C16 : 0, summed feature 3 and summed feature 8. The polar lipids comprise phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, an unidentified amino lipid, two unidentified amino-phospholipids, and three unidentified lipids. Based on phylogenetic, phenotypic, chemotaxonomic and genotypic analyses, strain JS9T represents a novel species of the genus Proteus, for which the name Proteus cibarius sp. nov. is proposed. The type strain is JS9T (=KACC 18404T=JCM 30699T). An emended description of the genus Proteus is also provided.

Weissella jogaejeotgali sp. nov., isolated from jogae jeotgal, a traditional Korean fermented seafood.

Strain FOL01T was isolated from traditionally fermented Korean jogae jeotgal (fermented clams). Phylogenetic sequence analysis of the 16S rRNA gene from FOL01T revealed that it is closely related to Weissella thailandensis FS61-1T and Weissella paramesenteroides ATCC 33313T with 99.39 % and 98.50 % 16S rRNA gene sequence similarities, respectively. API and VITEK analyses showed that strain FOL01T could be separated from its nearest phylogenetic relatives with respect to carbohydrate fermentation and antibiotic resistance. Subsequent amplified rRNA gene restriction analysis of 16S rRNA genes and HaeIII-restriction enzyme profiling of genomic DNAs revealed different band patterns. In addition, DNA-DNA hybridization of genomic DNAs showed 63.9 % relatedness. Analysis of the composition of cellular fatty acids confirmed that strain FOL01T differs from its close relatives and supports the proposal to assign this organism to a novel species of the genus Weissella. Based on these results, strain FOL01T could be classified as a novel species of the genus Weissella, for which the name Weissella jogaejeotgali sp. nov. is proposed. The type strain is FOL01T ( = KCCM 43128T = JCM 30589T).

Draft genome sequence of the extremely halophilic archaeon Haladaptatus cibarius type strain D43(T) isolated from fermented seafood.

An extremely halophilic archaeon, Haladaptatus cibarius D43T, was isolated from traditional Korean salt-rich fermented seafood. Strain D43T shows the highest 16S rRNA gene sequence similarity (98.7 %) with Haladaptatus litoreus RO1-28T, is Gram-negative staining, motile, and extremely halophilic. Despite potential industrial applications of extremely halophilic archaea, their genome characteristics remain obscure. Here, we describe the whole genome sequence and annotated features of strain D43T. The 3,926,724 bp genome includes 4,092 protein-coding and 57 RNA genes (including 6 rRNA and 49 tRNA genes) with an average G + C content of 57.76 %.

Characterization of salt-tolerant β-glucosidase with increased thermostability under high salinity conditions from Bacillus sp. SJ-10 isolated from jeotgal, a traditional Korean fermented seafood.

The β-glucosidase gene, bglC, was cloned from Bacillus sp. SJ-10 isolated from the squid jeotgal. Recombinant BglC protein overexpression was induced in Escherichia coli. The optimal pH and temperature of the enzyme, using p-nitrophenyl-β-D-glucopyranoside (pNPβGlc) as a substrate, were pH 6 and 40 °C, respectively. Enzymatic activity increased by 3.3- and 3.5-fold in the presence of 15% NaCl and KCl, respectively. Furthermore, enzyme thermostability improved in the presence of NaCl or KCl. At 45 °C in the presence of salts, the enzyme was stable for 2 h and maintained 80% activity. In the absence of salts, BglC completely lost activity after 110 min at 45 °C. Comparison of the kinetic parameters at various salt concentrations revealed that BglC had approximately 1.5- and 1.2-fold higher affinity and hydrolyzed pNPβGlc 1.9- and 2.1-fold faster in the presence of 15% NaCl and KCl, respectively. Additionally, the Gibb's free energy for denaturation was higher in the presence of 15% salt than in the absence of salt at 45 and 50 °C. Since enzymatic activity and thermostability were enhanced under high salinity conditions, BglC is an ideal salt-tolerant enzyme for further research and industrial applications.

Physiological Characteristics and Production of Folic Acid of Lactobacillus plantarum JA71 Isolated from Jeotgal, a Traditional Korean Fermented Seafood.

Folic acid, one of the B group of vitamins, is an essential substance for maintaining the functions of the nervous system, and is also known to decrease the level of homocysteine in plasma. Homocysteine influences the lowering of the cognitive function in humans, and especially in elderly people. In order to determine the strains with a strong capacity to produce folic acid, 190 bacteria were isolated from various kinds of jeotgal and chungkuk-jang. In our test experiment, JA71 was found to contain 9.03μg/mL of folic acid after 24 h of incubation in an MRS broth. This showed that JA71 has the highest folic acid production ability compared to the other lactic acid bacteria that were isolated. JA71 was identified as Lactobacillus plantarum by the result of API carbohydrate fermentation pattern and 16s rDNA sequence. JA71 was investigated for its physiological characteristics. The optimum growth temperature of JA71 was 37℃, and the cultures took 12 h to reach pH 4.4. JA71 proved more sensitive to bacitracin when compared with fifteen different antibiotics, and showed most resistance to neomycin and vancomycin. Moreover, it was comparatively tolerant of bile juice and acid, and displayed resistance to Escherichia coli, Salmonella Typhimurium, and Staphylococcus aureus with restraint rates of 60.4%, 96.7%, and 76.2%, respectively. These results demonstrate that JA71 could be an excellent strain for application to functional products.

Brevibacterium jeotgali sp. nov., isolated from jeotgal, a traditional Korean fermented seafood

A Gram-staining-positive, aerobic, non-motile bacterium, designated strain SJ5-8(T), was isolated from seau-jeot (shrimp jeotgal), a traditional fermented seafood in South Korea. Cells were non-spore-forming rods showing catalase- and oxidase-positive reactions. Growth of strain SJ5-8(T) was observed at 10-37 °C (optimum, 30 °C), at pH 6.0-9.0 (optimum, pH 7.5-8.5) and in the presence of 0-14% (w/v) NaCl (optimum, 5%). Phylogenetic inference based on 16S rRNA gene sequences showed that the strain formed a tight phyletic lineage with members of the genus Brevibacterium. Strain SJ5-8(T) was most closely related to Brevibacterium yomogidense MN-6-a(T), Brevibacterium daeguense 2C6-41(T) and Brevibacterium salitolerans TRM 415(T) with similarities of 98.9, 97.5 and 97.4%, respectively. The DNA-DNA relatedness values between strain SJ5-8(T) and the type strains of B. yomogidense, B. daeguense and B. salitolerans were 51.7 ± 1.9%, 22.2 ± 4.0% and 52.4 ± 3.8%, respectively. Chemotaxonomic data (major sole isoprenoid quinone, MK-8(H₂); major diagnostic diamino acid, meso-diaminopimelic acid; major polyamines, putrescine and cadaverine; major cellular fatty acids, anteiso-C(15:0), iso-C(15:0) and anteiso-C(17:0); major polar lipids, phosphatidylglycerol and diphosphatidylglycerol; DNA G+C content, 69.3 mol%) also supported the affiliation of strain SJ5-8(T) to the genus Brevibacterium. Therefore, strain SJ5-8(T) represents a novel species of the genus Brevibacterium, for which the name Brevibacterium jeotgali sp. nov. is proposed. The type strain is SJ5-8(T) ( =KACC 16911(T) =JCM 18571(T)).

Halomonas cibimaris sp. nov., isolated from jeotgal, a traditional Korean fermented seafood

Two moderately halophilic, facultatively aerobic, motile bacteria with flagella, designated strains 10-C-3(T) and 30-C-3, were isolated from jeotgal, a traditional Korean fermented seafood. Cells of the strains were observed to be ovoid-rods showing catalase- and oxidase-positive reactions and production of creamy-pink pigments. Growth of strain 10-C-3(T) was observed at 15-35 °C (optimum, 25-30 °C), at pH 5.5-9.0 (optimum, pH 7.0-7.5), and in the presence of 3-15 % (w/v) salts (optimum: 5-10 %). The two strains were found to contain C(18:1) ω7c, C(16:0), summed feature 3 (as defined by the MIDI system, comprising C(16:1) ω7c and/or C(16:1) ω6c), and C(12:0) 3-OH as the major cellular fatty acids. The G+C contents of the genomic DNA of strains 10-C-3(T) and 30-C-3 were determined to be 63.2 and 63.1 mol%, respectively and the respiratory quinone detected was ubiquinone 9 (Q-9) only. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strains 10-C-3(T)and 30-C-3 formed a distinct phyletic lineage within the genus Halomonas and are most closely related to Halomonas fontilapidosi 5CR(T) with 95.2 % of 16S rRNA sequence similarity. Strains 10-C-3(T)and 30-C-3 shared 99.2 % of 16S rRNA gene sequence similarity and their DNA-DNA relatedness value was 96.6 ± 0.9 %. On the basis of phenotypic, chemotaxonomic and molecular features, strains 10-C-3(T)and 30-C-3 represent a novel species of the genus Halomonas, for which the name Halomonas cibimaris sp. nov. is proposed. The type strain is 10-C-3(T) (= KACC 14932(T) = JCM 16914(T)).

Genome Sequence of Kocuria atrinae C3-8, Isolated from Jeotgal, a Traditional Korean Fermented Seafood

Kocuria is a Gram-positive coccus, catalase-positive, coagulase-negative, strictly aerobic bacterial genus in the family Micrococcaceae. Kocuria atrinae C3-8 was isolated from a traditional Korean fermented seafood. This study describes the first genome sequence of K. atrinae strain C3-8, which has a 3.19-Mbp genome and a G+C content of 63.8%.

대구횟대(Gymnocanthus herzensteini)를 이용한 식해 개발

Sik-hae is traditional Korean fermented seafood manufactured by mixing ingredients such as fish, radish, garlic, pepper, etc. To facilitate utilization of the black-edged sculpin Gymnocanthus herzensteini, which is an abundant unusable fish caught in the East Sea, sculpin sik-hae was developed for commercialization as a low-salt fermented food. There was no significant change in the proximate composition of the sculpin sik-hae during storage. The pH of the sculpin sik-hae decreased, whereas the acidity, amino-N, and volatile basic nitrogen contents increased as fermentation progressed. The number of microflora increased gradually up to 14 days of fermentation and then decreased. Based on a sensory evaluation, sculpin sik-hae stored at <TEX>$-1^{\circ}C$</TEX> was superior to that stored at <TEX>$5^{\circ}C$</TEX>. Therefore, sculpin sik-hae can be commercialized as a new fermented seafood.

Genome Sequence of Extracellular-Protease-Producing Alishewanella jeotgali Isolated from Traditional Korean Fermented Seafood

Alishewanella jeotgali MS1(T) (= KCTC 22429(T) = JCM 15561(T)) was isolated from a traditional Korean fermented seafood, gajami sikhae (jeotgal), and has been reported as a novel species. A. jeotgali was proven to have extracellular proteolytic activity, which may play an important role in the fermentation environment of food containing fish flesh. Here, we present the genome sequence of Alishewanella jeotgali MS1(T) as the first sequenced strain in the genus Alishewanella and its taxonomic relatives.

저식염 오징어 식해의 생리활성 및 유통기한 설정

본 연구는 전통적인 발효식품인 식해에 대하여 염농도에 따른 발효기간별 품질특성, 발효 최적조건 및 유통기한 설정, 발효 최적조건에서의 생리활성을 측정하여 우리 전통식품인 식해를 저염화하고 생산 보급함과 동시에 이에 대한 과학적 자료를 제공하는 것을 목표로 하였으며 그 결과를 요약하면 다음과 같다. 본 연구에서 제조한 오징어 식해는 발효기간에 경과함에 따라 염농도가 낮고 온도가 높을수록 pH는 급격하게 감소하였으며, 아미노질소 및 휘발성 염기질소의 함량은 급격하게 증가하였다. 발효최적조건은 5% 염농도의 식해를 <TEX>$-1^{\circ}C$</TEX>에서 53일간 발효한 것이었고 유통기한은 염농도 5%의 식해를 <TEX>$-1^{\circ}C$</TEX>에서 142일간 저장한 것이었다. 식해는 DPPH 저해활성이 확인되어 항산화 효과가 있으나, hydrolxyl 및 hydrogen peroxide radical 소거능, 항당뇨, 항대장암 및 주름제거 활성은 낮아 기능성 소재로의 활용은 보충연구가 필요하다고 판단된다. 유리아미노산의 조성은 정미 아미노산이 고미 아미노산보다 많아 맛에서 우수하였으며, 시판중인 다른 수산발효식품과 관능적으로 큰 차이가 없었다. 이상의 결과를 고려할 때 <TEX>$-1^{\circ}C$</TEX>의 저온에서 식염 5%로 식해를 저염화 시킨다면 현대인의 식기호에 적합한 식품으로 영양학적 측면이나 시장성 측면에서 큰 효과를 낼 수 있을 것이라 판단된다. Sikhae is a traditional Korean fermented seafood with a 7-10% salt concentration. Consumers have begun to look for low-salt food because excess salt is known to cause hypertension and gastric cancer. The quality characteristics of low-salt squid sikhae were investigated at different fermentation temperatures and periods, so as to determine its shelflife. The shelf-life of the low-salt (5%) squid sikhae at <TEX>$-1^{\circ}C$</TEX> based on pH was 142 days. The functional activities of the ethanol extract of squid sikhae such as its antioxidant activity and inhibitions on <TEX>${\alpha}$</TEX>-glucosidase, <TEX>${\beta}$</TEX>-glucuronidase, and elastase were stronger than those of the water extract. Based on the results of sensory evaluation, the low-salted squid sikhae was very similar to fermented seafood. In conclusion, low-salt sikhae is commercially viable.

Leucobacter celer sp. nov., isolated from Korean fermented seafood

A novel, Gram-reaction-positive, aerobic, rod-shaped, non-motile bacterial strain, designated NAL101(T), was isolated from gajami-sikhae, a traditional Korean fermented seafood made of flatfish. Growth occurred at 4-45 °C, at pH 5-10 and in 0-12 % (w/v) NaCl. Optimum growth occurred at 30-37 °C, at pH 8 and in 0-1 % (w/v) NaCl. The cell-wall amino acids were 2,4-diaminobutyric acid, alanine, glycine, threonine and glutamic acid and the major fatty acids were anteiso-C(15 : 0), iso-C(16 : 0) and anteiso-C(17 : 0). The predominant menaquinone was MK-11. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and an unknown glycolipid. The 16S rRNA gene sequence of strain NAL101(T) showed 97.7 % similarity to that of Leucobacter chironomi MM2LB(T), its closest relative. The DNA G+C content was 68.8 mol% and DNA-DNA hybridization values with closely related strains were <22 %. Phylogenetic analyses based on 16S rRNA gene sequences as well as differences in its physiological and biochemical characteristics indicated that strain NAL101(T) represents a novel species of the genus Leucobacter in the family Microbacteriaceae, for which the name Leucobacter celer sp. nov. is proposed. The type strain is NAL101(T) ( = KACC 14220(T) = JCM 16465(T)).

새우젓으로부터 혈전과 chitin 분해능을 지닌 균주 Bacillus licheniformis SC082의 분리 및 특성

전통발효식품인 새우젓으로부터 혈전과 chitin 분해력이 우수한 균을 분리하였으며 16S rRNA 염기서열 분석으로 B. licheniformis와 가장 유사한 균주임을 확인하였다. 이 균주를 B. licheniformis SC082로 명명하였고, 최적 생육조건은 <TEX>$37^{\circ}C$</TEX>, pH 7.0, 염 농도 6%로 확인되었다. 이 균주의 기질특이성을 조사한 결과, 우수한 혈전분해력을 나타냈으며 1% 농도의 colloidal chitin의 첨가에 의하여 chitinase 활성이 증가됨을 관찰할 수 있었다. 또한 지질 분해능은 없었고 약한 skim milk 분해력을 가지고 있었다. SDS-PAGE와 zymogram 분석 결과, 이 균은 혈전분해효소 isozyme과 chitinase isozyme을 생성하는 균주로 확인되었다. 그 대략적인 분자량은 각각 22.0, 66.0, 72.0 kDa과 55.0, 62.0 kDa이었다. B. licheniformis SC082 균주가 생성하는 혈전분해효소는 pH 9.0 그리고 <TEX>$50^{\circ}C$</TEX>까지 안정하게 유지되었고, 이와 더불어, chitinase 활성은 pH 5, <TEX>$45^{\circ}C$</TEX>일 때 높게 나타났다. B. licheniformis SC082 균주의 DPPH 전자공여능법에 의한 항산화력은 농도의 증가에 따라 상승되었는데 <TEX>$20\;{\mu}g$</TEX>의 균상등액에 대한 항산화력은 약 31%으로 나타났다. Shrimp Jeot-Gal is a popular traditional Korean fermented seafood and has been used for seasoning. We isolated a bacterium showing strong extra-cellular fibrinolysis and chitinase activity from shrimp Jeot-Gal and the strain was designated SC082. SC082 was identified as Bacillus licheniformis by 16S rRNA sequence homology search. B. licheniformis SC082 exhibited optimum temperature, pH, and salt concentration at <TEX>$37^{\circ}C$</TEX>, pH 7.0, and 6%, respectively. Substrate specificity of the culture supernatant from B. licheniformis SC082 was detected in fibrin, skim milk, and chitin plate. The fibrinolytic activity was highly maintained up to <TEX>$50^{\circ}C$</TEX> at a pH of 7.0 for 3 hr and was stable up to pH 9.0 at <TEX>$37^{\circ}C$</TEX> for 3 hr. The chitinase activity was remarkably induced by addition of 1.0% colloidal chitin and the pH and temperature optima of the enzyme were 5.0 and <TEX>$45^{\circ}C$</TEX>, respectively. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis and zymogram analysis, this strain produced three fibrinolytic isozymes and two chitinase isozymes. The approximate molecular weights of the putative fibrinolytic enzymes were 23.0, 62.0, and 72.0 kDa and those of the chitinases were 62.0 and 55.0 kDa, respectively. The antioxidant activity of SC082 was also measured by using 2,2-diphenyl-l-picryl-hydrazyl (DPPH) free radical. The DPPH radical scavenging was slightly increased in a dose-dependent manner.

Lentibacillus jeotgali sp. nov., a halophilic bacterium isolated from traditional Korean fermented seafood

A novel, Gram-positive, non-motile, endospore-forming and moderately halophilic bacterium, strain Grbi(T), was isolated from a traditional Korean fermented seafood. The organism grew optimally in the presence of 10-15 % NaCl, at 37 degrees C and pH 8.0. The peptidoglycan of the cell wall consisted of meso-diaminopimelic acid, and the predominant menaquinone was MK-7. The major fatty acids of strain Grbi(T) were iso-C(16 : 0) (36.4 %), anteiso-C(15 : 0) (30.3 %) and iso-C(14 : 0) (18.2 %). The polar lipids were phosphatidylglycerol, diphosphatidylglycerol and an unidentified glycolipid. The genomic DNA G+C content was 42.5 mol%. Strain Grbi(T) was most closely related to the type strain Lentibacillus kapialis JCM 12580(T), with which it shared 97.5 % 16S rRNA gene sequence similarity. The DNA-DNA hybridization value between strains Grbi(T) and L. kapialis JCM 12580(T) was 8 %. Based on phenotypic, genotypic and phylogenetic data, strain Grbi(T) should be classified as a novel species within the genus Lentibacillus, for which the name Lentibacillus jeotgali sp. nov. is proposed. The type strain is Grbi(T) (=KCTC 13300(T)=JCM 15795(T)).