• Journal of Life Science
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• v.22 no.10
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• pp.1295-1306
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• 2012

A microorganism producing carboxymethylcellulase (CMCase) was isolated from seawater and identified as Bacillus atrophaeus. This species was designated as B. atrophaeus LBH-18 based on its evolutionary distance and the phylogenetic tree resulting from 16S rDNA sequencing and the neighbor-joining method. The optimal conditions for rice bran (68.1 g/l), peptone (9.1 g/l), and initial pH (7.0) of the medium for cell growth was determined by Design Expert Software based on the response surface method; conditions for production of CMCase were 55.2 g/l, 6.6 g/l, and 7.1, respectively. The optimal temperature for cell growth and the production of CMCase by B. atrophaeus LBH-18 was $30^{\circ}C$. The optimal conditions of agitation speed and aeration rate for cell growth in a 7-l bioreactor were 324 rpm and 0.9 vvm, respectively, whereas those for production of CMCase were 343 rpm and 0.6 vvm, respectively. The optimal inner pressure for cell growth and production of CMCase in a 100-l bioreactor was 0.06 MPa. Maximal production of CMCase under optimal conditions in a 100-l bioreactor was 127.5 U/ml, which was 1.32 times higher than that without an inner pressure. In this study, rice bran was developed as a carbon source for industrial scale production of CMCase by B. atrophaeus LBH-18. Reduced time for the production of CMCase from 7 to 10 days to 3 days by using a bacterial strain with submerged fermentation also resulted in increased productivity of CMCase and a decrease in its production cost.

• Korean Journal of Medicinal Crop Science
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• v.18 no.6
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• pp.429-438
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• 2010

The use of cellulolytic lactic acid bacteria in new method to prepare high nutrition complementary foods was investigated. For the screening of cellulolytic lactic acid bacteria, more than 1,150 bacterial colony were isolated from diluted infant feces samples. A typical strain which appeared the most excellent cellulolytic activities was identified novel acidophilic Enterococcus sp. TO-94 through the results of morphological, biochemical and chemotaxonomic characteristics and 16S rDNA sequencing. The optimal lactic acid fermentation conditions of Omija(Schizandra chinensis Baillon) by Enterococcus sp. TO-94 were as follows: pH and temperature were 3.0 and $37^{\circ}C$, respectively, and fermentation time was 20hrs. The fructose and glucose were major free sugar and the contents were 5.83 and 4.30 mg/g after fermentation, respectively. The contents of lactic acid and acetic acid were 9.84 mg/g and 2.08 mg/g after fermentation, respectively. The vitamin $B_1$, $B_2$, niacin, folic acid and C were major vitamin in the fermented broth, the contents were 1.5~3 times higher than those of initial fermentation time. Also, the contents of polyphenol and anthocyanine were 3.8 and 1.2 times higher than those of initial fermentation time.

• Journal of Microbiology and Biotechnology
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• v.18 no.5
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• pp.952-957
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• 2008

A Gram-negative bacterium, named LY402, was isolated from contaminated soil. 16S rDNA sequencing and measurement of the physiological and biochemical characteristics identified it as belonging to the genus Enterohacter. Degradation experiments showed that LY402 had the ability to aerobically transform 79 of the 91 major congeners of Aroclor 1242, 1254, and 1260. However, more interestingly, the strain readily degraded certain highly chlorinated and recalcitrant polychlorinated biphenyls (PCBs). Almost all the tri- and tetra-chlorobiphenyls (CBs), except for 3,4,3',4'-CB, were degraded in 3 days, whereas 73% of 3,4,3',4'-, 92% of the penta-, 76% of the hexa-, and 37% of the hepta-CBs were transformed after 6 days. In addition, among 12 octa-CBs, 2,2',3,3',5,5',6,6-CB was obviously degraded, and 2,2',3,3',4,5,6,6'- and 2,2',3,3',4,5,5',6'-CB were slightly transformed. In a metabolite analysis, mono- and dichlorobenzoic acids (CBAs) were identified, and parts of them were also transformed by strain LY402. Analysis of PCB degradation indicated that strain LY402 could effectively degrade PCB congeners with chlorine substitutions in both ortho- and para-positions. Consequently, this is the first report of an Enterobacteria that can efficiently degrade both low and highly chlorinated PCBs under aerobic conditions.

• Journal of Microbiology and Biotechnology
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• v.18 no.7
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• pp.1290-1297
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• 2008

To investigate the diversities of Accumulibacter phosphatis and its polyhydroxyalkanoate (PHA) synthase gene (phaC) in enhanced biological phosphorus removal (EBPR) sludge, an acetate-fed sequencing batch reactor was operated. Analysis of microbial communities using fluorescence in situ hybridization and 16S rRNA gene clone libraries showed that the population of Accumulibacter phosphatis in the EBPR sludge comprised more than 50% of total bacteria, and was clearly divided into two subgroups with about 97.5% sequence identity of the 16S rRNA genes. PAO phaC primers targeting the phaC genes of Accumulibacter phosphatis were designed and applied to retrieve fragments of putative phaC homologs of Accumulibacter phosphatis from EBPR sludge. PAO phaC primers targeting $G_{1PAO},\;G_{2PAO},\;and\;G_{3PAO}$ groups produced PCR amplicons successfully; the resulting sequences of the phaC gene homologs were diverse, and were distantly related to metagenomic phaC sequences of Accumulibacter phosphatis with 75-98% DNA sequence identities. Degenerate NPAO (non-PAO) phaC primers targeting phaC genes of non-Accumulibacter phosphatis bacteria were also designed and applied to the EBPR sludge. Twenty-four phaC homologs retrieved from NPAO phaC primers were different from the phaC gene homologs derived from Accumulibacter phosphatis, which suggests that the PAO phaC primers were specific for the amplification of phaC gene homologs of Accumulibacter phosphatis, and the putative phaC gene homologs by PAO phaC primers were derived from Accumulibacter phosphatis in the EBPR sludge. Among 24 phaC homologs, a phaC homolog (GINPAO-2), which was dominant in the NPAO phaC clone library, showed the strongest signal in slot hybridization and shared approximately 60% nucleotide identity with the $G_{4PAO}$ group of Accumulibacter phosphatis, which suggests that GINPAO-2 might be derived from Accumulibacter phosphatis. In conclusion, analyses of the 16S rRNA and phaC genes showed that Accumulibacter phosphatis might be phylogenetically and metabolically diverse.

• Microbiology and Biotechnology Letters
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• v.43 no.2
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• pp.134-141
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• 2015

An agarolytic marine bacterium (H9) was isolated from the coastal seawater of the West Sea, South Korea. The isolate, H9, was gram-negative and rod-shaped with a smooth surface and polar flagellum. Cells grew at 20-30℃, between pH 5.0 and 9.0, and in ASW-YP (Artificial Sea Water-Yeast extract, Peptone) media containing 1-5% (w/v) NaCl. The G+C content was 41.56 mol%. The predominant isoprenoid quinone in strain H9 was ubiquinone-8. The major fatty acids (>10%) were C_16:1ω7c (34.3%), C_16:0 (23.72%), and C_18:1ω7c (13.64%). Based on 16S rRNA gene sequencing, and biochemical and chemotaxonomic characterization, the strain was designated as Pseudoalteromonas sp. H9 (=KCTC23887). In liquid culture supplemented with 0.2% agar, the cell density and agarase activity reached a maximum level of OD = 4.32 (48 h) and OD = 3.87 (24 h), respectively. The optimum pH and temperature for the extracellular crude agarases of H9 were 7.0 and 40℃, respectively. Thin-layer chromatography analysis of the agarase hydrolysis products revealed that the crude agarases hydrolyze agarose into neoagarotetraose and neoagarohexaose. Therefore, the new agar-degrading strain, H9, can be applicable for the production of valuable neoagarooligosaccharides and for the complete degradation of agar in bio-industries.

• Korean Journal of Agricultural Science
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• v.37 no.3
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• pp.399-404
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• 2010

Single nucleotide polymorphisms (SNPs) in chicken lysozyme (LYZ) gene were investigated in this study. The identification of SNPs in both exon and intron in LYZ gene has led to understanding of evolution for the domestic chicken populations. A total of 24 samples from two Korean native commercial chicken populations (CCPs) were used for the initial identification of SNPs by mixing three DNA samples for sequencing experiments. By comparing with red jungle fowl (RJF), two commercial chicken populations have 18 common polymorphisms. Between two commercial chicken populations, 15 polymorphisms were identified. Of the 33 polymorphisms identified, two indels (21 and 4 bp) were found. Whereas, only one polymorphism in exon 2 at the bp position 1426 was a non-synonymous substitution (p.Ala49Val), indicating the amino acid changes. The identified non-synonymous substitution (p.Ala49Val) is located close to the catalytic sites of the enzyme, which might affect its activity. In our investigation, the polymorphisms in LYZ gene can provide broad ideas for the variation of Korean native chicken populations from the ancestor of chicken breeds as well as the some biological functions of the LYZ gene.

• Research in Plant Disease
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• v.26 no.1
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• pp.8-18
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• 2020

Red pepper, one of the major economic crops in Korea, is being affected by anthracnose disease caused by Colletotrichum acutatum. To control this disease, an antagonistic bacterial strain, Bacillus subtilis YGB36 identified by 16S rDNA sequencing, physiological and biochemical analyses is used as a biological control agent. In vitro screening revealed that the strain YGB36 possess strong antifungal activity against the pathogen Cylindrocarpon destructans. The strain exhibited cellulase, protease, amylase, siderophore production and phosphate solubility. In vitro conidial germination of C. acutatum was most drastically inhibited by YGB36 cell suspensions (10⁶ cfu/ml) or culture filtrate. Development of anthracnose symptoms was reduced on detached immature green pepper fruits by treatment with cell suspensions, and its control value was recorded as 65.7%. The YGB36 bacterial suspension treatment enhanced the germination rate of red pepper seeds and promoted root development and growth under greenhouse conditions. The in vitro screening of fungicide and insecticide sensitivity test against YGB36 revealed that the bacterial growth was not affected by any of the insecticides, and 11 fungicides out of 21 used. Collectively, our results clearly suggest that the strain YGB36 is considered as one of the potential biocontrol agents against anthracnose disease in red pepper.

• Microbiology and Biotechnology Letters
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• v.37 no.3
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• pp.204-212
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• 2009

A strain producing ${\alpha}$-galactosidase and ${\beta}$-glucosidase was isolated from Kimchi. The isolated strain was identified as Weissella cibaria by 16S rDNA analysis and designated as Weissella cibaria K-M1-4. The enzyme activity of ${\alpha}$-galactosidase and ${\beta}$-glucosidase reached the maximum in the soy medium at $37^{\circ}C$ for 24 hr. The enzymes were purified by ethanol fractionation, DEAE sepharose fast flow, and sephacryl S-100HR column chromatography. ${\alpha}$-Galactosidase specific activity was shown by 576 Units/mg protein and the yield was 3.5% of the total activity of crude extracts. ${\beta}$-glucosidase specific activity was shown by 480 Units/mg protein and the yield was 2.9% of the total activity of crude extracts. The optimum temperature for ${\alpha}$-galactosidase was $60^{\circ}C$ and 43% of its original activity remained when it was treated at $80^{\circ}C$ for 30 min. For ${\alpha}$-galactosidase shows the optimum pH of 8.0 and is fairly stable between pH5.0 and pH9.0. The enzyme activity was increased in the presence of $Fe^{2+}$ and $Cu^{2+}$. The value of Km and Vmax for the enzyme were 0.98 mM and $1.81{\mu}$mole/min, respectively. The ${\beta}$-glucosidase has the optimum temperature of $50^{\circ}C$ and 46% of its original activity remained when it was treated at $80^{\circ}C$ for 30min. Its optimum pH of 7.0 and is fairly stable between pH5.0 and pH9.0. The enzyme activity was increased in the presence of $Fe^{2+},\;Co^{2+}$ and $Cu^{2+}$. The value of Km and Vmax for the enzyme were 1.24 mM and $6.81{\mu}$mole/min, respectively.

• Journal of Life Science
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• v.27 no.11
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• pp.1276-1289
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• 2017

This study isolated and purified the antimicrobial peptide McSSP-31 from an acidified hemocyte extract of a Mytilus coruscus. The antimicrobial peptide was purified by using a $C_{18}$ reversed-phase high-performance liquid chromatography (HPLC). The peptide was determined to be 3330.549 Da by matrix assisted-laser desorption ionization time-of-flight mass spectrophotometer (MALDI-TOF/MS). The N-terminus of a 14 amino-acid sequence was identified as P-S-P-T-R-R-S-T-S-R-S-K-S-R by Edman degradation method. The acquired sequence showed a 93% similarity with the sperm-specific protein Phi-1, which is from M. californianus. The identified open-reading frame (ORF) of peptide was 306 bp encoding 101 amino acids, which was analyzed by rapid amplification of cDNA ends (RACE), cloning and sequencing analysis. We compared the full sequence with other known proteins that reveal the sperm-specific protein Phi-1 (93.5%) of M. californianus. Synthesized antimicrobial peptide (McSSP-31) showed antibacterial activity against gram-positive bacteria including B. subtilis, S. mutans, S. aureus and gram-negative bacteria including E. coli, K. pneumoniae, P. mirabilis, P. aeruginosa and fungi, C. albicans. Also, synthesized peptide showed strong antibacterial activity against antibiotic-resistant strains, including S. aureus. The cytotoxicity of the peptide was determined by using the HUVEC human cell line. The peptide did not exhibit any significant cytotoxic effects on the normal human cell line, and it had very low hemolytic activity with flounder hemoglobin. The results demonstrated that peptide purified from the hemocyte of a M. coruscus exhibits antibacterial activity against various bacteria and has the potential to be an alternative antibiotic agent.

• Journal of Veterinary Science
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• v.21 no.3
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• pp.46.1-46.18
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• 2020

Background: High concentrations of particulate matter less than 2.5 ㎛ in diameter (PM2.5) in poultry houses is an important cause of respiratory disease in animals and humans. Pseudomonas aeruginosa is an opportunistic pathogen that can induce severe respiratory disease in animals under stress or with abnormal immune functions. When excessively high concentrations of PM2.5 in poultry houses damage the respiratory system and impair host immunity, secondary infections with P. aeruginosa can occur and produce a more intense inflammatory response, resulting in more severe lung injury. Objectives: In this study, we focused on the synergistic induction of inflammatory injury in the respiratory system and the related molecular mechanisms induced by PM2.5 and P. aeruginosa in poultry houses. Methods: High-throughput 16S rDNA sequence analysis was used for characterizing the bacterial diversity and relative abundance of the PM2.5 samples, and the effects of PM2.5 and P. aeruginosa stimulation on inflammation were detected by in vitro and in vivo. Results: Sequencing results indicated that the PM2.5 in poultry houses contained a high abundance of potentially pathogenic genera, such as Pseudomonas (2.94%). The lung tissues of mice had more significant pathological damage when co-stimulated by PM2.5 and P. aeruginosa, and it can increase the expression levels of interleukin (IL)-6, IL-8, and tumor necrosis factor-α through nuclear factor (NF)-κB pathway in vivo and in vitro. Conclusions: The results confirmed that poultry house PM2.5 in combination with P. aeruginosa could aggravate the inflammatory response and cause more severe respiratory system injuries through a process closely related to the activation of the NF-κB pathway.