• Korean Journal of Microbiology
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• v.52 no.1
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• pp.120-124
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• 2016

A certain size of DNA (28-29 kb long) to be packaged into P2-size head and the mutation in sid gene of bacteriophage P4 are the major factors to overcome "P2 sir-associated helper inefficiency". To clarify whether the presence of sid mutation is essential to overcome "P2 sir-associated helper inefficiency" or not, we tested the P4 derivative, P4 delRI::kmr, which is $sid^+$ and whose genome size supposed to be 28.5 kb long in the case of being packaged into $P2_{sir3}$-sized large head. As P4 delRI::kmr showed the low EOP with P2 sir3 lysogen, P4 delRI::kmr phage stock was prepared in P2 sir3 lysogen host to increase the EOP with P2 sir3 lysogen. Through this process, P4 delRI::kmr had been adapted for P2 sir3 lysogen. With a CsCl buoyant equilibrium density gradient experiment and gel electrophoresis of the isolated DNA, it was evident that the adaptation of P4 delRI::kmr for P2 sir3 lysogen was caused by the conformational change of DNA to be packaged into large head. The burst size determination experiments with P4 delRI::kmr phage stock adapted for P2 sir3 lysogen and normal P4 delRI::kmr phage stock showed that not the sid mutation but the size of DNA to be packaged (28-29 kb long) was essential to overcome "P2 sir-associated helper inefficiency".

• Food Science of Animal Resources
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• v.36 no.6
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• pp.779-786
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• 2016

This study aimed to evaluate the prevalence of Listeria monocytogenes on livestock farms in Korea and determine their serotypes and genetic correlations. Twenty-five livestock farms in Korea (central: 15, south west: 7, south east: 3) were visited 2-3 times, and 2,018 samples (feces: 677, soil: 680, silage: 647, sludge: 14) were collected. Samples were enriched in LEB (Listeria enrichment broth) and Fraser broth media, and then plated on Palcam agar. The isolates were identified by PCR and 16S rRNA gene sequencing. Then, the sero-types, presence of virulence genes (actA, inlA, inlB, plcB, and hlyA), and antibiotic resistance were determined. Genetic correlations among the isolates were evaluated by analyzing the restriction digest pattern with AscI. Of the 2,018 samples, only 3 (0.15%) soil samples (FI-1-FI-3) from 1 farm in the south east region were positive for L. monocytogenes. Based on biochemical tests and multiplex PCR, the serotype of the isolates were 4ab (FI-1 and FI-3) and 3a (FI-2), which are not common in foodborne L. monocytogenes. The 3a sero-type isolate was positive for all tested virulence genes, whereas the 4ab serotype isolates were only positive for hlyA, actA, and inlA. The isolates were resistant to all 12 tested antibiotics, especially FI-3. The genetic correlations among the isolates were 100% for those of the same serotype and 26.3% for those of different serotypes. These results indicate that the prevalence of L. monocytogenes on livestock farms in Korea is low; however, the isolates are pathogenic and antibiotic resistant.

• Food Science of Animal Resources
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• v.40 no.5
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• pp.689-698
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• 2020

The aim of study was to scrutinize the physicochemical and protein profile of milk obtained from local Pakistani breeds of milch animals such as Nilli-Ravi buffalo, Sahiwal cow, Kajli sheep, Beetal goat and Brela camel. Physicochemical analysis unveiled maximum number of total solids and protein found in sheep and minimum in camel. Buffalo milk contains the highest level of fat (7.45%) while camel milk contains minimum (1.94%). Ash was found maximum in buffalo (0.81%) and sheep (0.80%) while minimum in cow's milk (0.71%). Casein and whey proteins were separated by subjecting milk to isoelectric pH and then analyzed through sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The results showed heterogeneity among these species. Different fractions including α_S1, α_S2, κ-casein, β-casein and β-lactoglobulen (β-Lg) were identified and quantitatively compared in all milk samples. Additionally, this electrophoretic method after examining the number and strength of different protein bands (α_S1, α_S2, β-CN, α-LAC, BSA, and β-Lg, etc.), was helpful to understand the properties of milk for different processing purposes and could be successfully applied in dairy industry. Results revealed that camel milk was best suitable for producing allergen free milk protein products. Furthermore, based on the variability of milk proteins, it is suggested to clarify the phylogenetic relationships between different cattle breeds and to gather the necessary data to preserve the genetic fund and biodiversity of the local breeds. Thus, the study of milk protein from different breed and species has a wide range of scope in producing diverse protein based dairy products like cheese.

• The Journal of Korean Medicine
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• v.26 no.1 s.61
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• pp.174-186
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• 2005

Objectives : The water extract of Samul-tang (SMT) has traditionally been used for treatment of ischemic heart and brain damage in oriental medicine. However, little is known about the mechanism by which the water extract of SMT rescues cells from these damages. Methods: This study was designed to investigate the protective mechanisms of SMT on oxidative stress-induced toxicity in H9c2 cardiomyoblast cells. Treatment with $H_2O_2$ markedly induced death of H9c2 cardiomyoblast cells in a dose-dependent manner. Results: The characteristics of H20z-induced death of H9c2 showed apparent apoptotic features such as DNA fragmentation and morphological change. However, SMT significantly reduced both H202-induced cell death and morphological change. The decrease of Bc-2 expression by High were inhibited by SMT. In addition, the increase of Bax expression was also inhibited by SMT. The cotreatment of SMT and $H_2O_2$ in H9c2 cells also induced the phosphorylation of ERK in a time-dependent manner. Moreover, PD98059, a specific inhibitor of ERK1/2 attenuated the protective effects of SMT on $H_2O_2-induced$ toxicity in H9c2 cardiomyoblast cells. These results suggest that both ERK1/2 signaling pathways play important roles in the protective effects of SMT on $H_2O_2-induced$ apoptotic death of H9c2 cells. Also, the expression profile of proteins in $H_2O_2$ cardiomyoblast cells were screened by using two-dimensional (2-D) gel electrophoresis. Among 300 spots resolved in 2-D gels, the comparison of control versus apoptosis cells revealed that signal intensity of 17 spots increased and 11 spots decreased. Conclusions: Taken together, this study suggests that the protectiw effects of the water extract of SMT against oxidative damages may be mediated by the modulation of Bc1-2 and Bax expression via the regulation of the ERK signaling pathway.

• Microbiology and Biotechnology Letters
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• v.39 no.3
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• pp.245-251
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• 2011

[ ${\alpha}$ ]Galactosidase was purified from a culture filtrate of Mortierella sp. by CM-sephadex C-50, and subsequent Sephadex G-100 column chromatography. The final preparation thus obtained showed a single band on SDS-polyacrylamide gel electrophoresis. The molecular weight was determined to be 56 kDa. $Gal^3Man^4$ ($6^3$-mono-O-${\alpha}$-D-galactopyranosyl-4-O-${\beta}$-D-mannotetraose), $Gal^{2,3}Man_5$ ($6^{2,3}$-di-O-${\alpha}$-D-galactopyranosyl-4-O-${\beta}$-D-mannopentaose), $Gal_2Man_3$ ($6^2$-mono-O-${\alpha}$-D-galactopyranosyl-4-O-${\beta}$-D-mannotriose), $Gal^2Man_6$ ($6^2$-mono-O-${\alpha}$-D-galactopyranosyl-4-O-${\beta}$-D-mannohexaose) and $Gal^2Man_5$ ($6^2$-mono-O-${\alpha}$-D-galactopyranosyl-4-O-${\beta}$-D-mannopentaose), prepared from 3 types of microbial ${\beta}$-mannnanase, were used as substrates. $Gal^3Man_4$ and $Gal^2Man_3$ had a stubbed ${\alpha}$-galactosyl residue on the $2^{nd}$ and $3^{rd}$ mannose from the reducing end of mannotetraose and mannotriose, thus ${\alpha}$-galactosidase showed a preference for stubbed ${\alpha}$-galactosyl residue. ${\alpha}$-Galactosidase hydrolyzed $Gal^3Man_4$ more rapidly than $Gal^2Man_3$. However, ${\alpha}$-galactosidase hardly acted on $Gal^{2,3}Man_5$, $Gal^2Man_6$ or $Gal^2Man_5$. The enzyme hydrolyzed melibiose to galactose and glucose, raffinose to galactose and sucrose, and also stachyose to galactose and raffinose.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.3
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• pp.296-308
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• 1996

Proteolytic enzymes responsible for post-mortem degradation of the fish tissues have been studied in regard with screening the proteases distributed in the fish body by reacting with the specific synthesized substrates. Activities of cathepsin L, B, H, G, and D like enzymes were detected in the muscle crude protease from the both kind of fish, dark fleshed fish (anchovy, Engraulis japonica, and gizzard-shad, Clupanodo punctatus) and white fleshed fish (seabass, Lateolabrax japonicus, and sole, Pleuronichthys cornutus), however, those of chymotrypsin, trypsin, pepsin, and peptidase like enzymes were observed 3n the viscera crude pretense from the fish. Proteolytic activities of the muscle crude protease at pH 6.0 were similar to those of the viscera crude protease at pH 8.0, but, those of the viscera crude protease at pH 8.0 were about 2 times higher than those at pH 6.0. The muscle and viscera crude protease from anchovy showed the strongest proteolytic activity among the four fish crude proteases and the proteolytic activity of the viscera crude protease was approximately 100 times higher than that of the muscle crude protease, which suggest that viscera proteases were more contributed on the development of post-mortem changes than muscle proteases. With the degradation patterns on SDS-polyacrylamide gel electrophoresis against yellowtail myofibrillar proteins, the muscle and viscera crude protease of the four fishes were primary responsible for the degradation of myosin heavy chain, and myosin light chain and actin, respectively.

• Journal of Ginseng Research
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• v.40 no.1
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• pp.28-37
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• 2016

Background: Panax ginseng cannot be cultivated on the same land consecutively for an extended period, and the underlying mechanism regarding microorganisms is still being explored. Methods: Polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE) and BIO-LOG methods were used to evaluate the microbial genetic and functional diversity associated with the P. ginseng rhizosphere soil in various cultivation ages and modes. Results: The analysis of microbial diversity using PCR-DGGE showed that microbial communities were significantly variable in composition, of which six bacterial phyla and seven fungal classes were detected in P. ginseng soil. Among them, Proteobacteria and Hypocreales dominated. Fusarium oxysporum, a soilborne pathogen, was found in all P. ginseng soil samples except R0. The results from functional diversity suggested that the microbial metabolic diversity of fallow soil abandoned in 2003was the maximum and transplanted soil was higher than direct-seeding soil and the forest soil uncultivated P. ginseng, whereas the increase in cultivation ages in the same mode led to decreases in microbial diversity in P. ginseng soil. Carbohydrates, amino acids, and polymers were the main carbon sources utilized. Furthermore, the microbial diversity index and multivariate comparisons indicated that the augmentation of P. ginseng cultivation ages resulted in decreased bacterial diversity and increased fungal diversity, whereas microbial diversity was improved strikingly in transplanted soil and fallow soil abandoned for at least one decade. Conclusion: The key factors for discontinuous P. ginseng cultivation were the lack of balance in rhizosphere microbial communities and the outbreak of soilborne diseases caused by the accumulation of its root exudates.

• Journal of the East Asian Society of Dietary Life
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• v.7 no.3
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• pp.289-300
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• 1997

Newborn dog chymosin was extracted from the stomachs of dogs of 2 weeks of age, and was purified by ion exchange chromatography. Half of the sequence was determined by amino acid sequencing and the complete sequence was deduced from a cloned chymosin cDNA Results showed that the zymogen showed 79% sequence identity with calf prochymosin and 54% identity with porcine pepsinogen A The size of the propart and location of the residue which becomes the amino-terminus in the active enzyme was the same in the prochymosins. The maximum general proteolytic activity at pH 3.2 of newborn dog chymosin was 3-4% of that of porcine pepsin A at pH 2, whereas the milk clotting activity relative to the general proteolytic activity of newborn dog chymosin was much higher than that of calf chymosin. Agar gel electrophoresis at pH 5.2 of stomach extracts of individual dogs showed the existence of two predominant genetic variants of zymogen and enzyme. The two variants could not be distinguished by amino acid composition or amino-terminal sequencing, and no differences in the enzymatic properties of the genetic variants were observed. It was concluded that of the residues that participate in the substrate binding, calf and newborn dog chymosin differ in the following positions (porcine pepsin numbering, subsites in parentheses) : Ser 12 Thr(S$_4$), Leu 30 Val(S$_1$/S$_3$), His 74 Gln(S'$_2$), Val 111 Ile(S$_1$/S$_3$), Lys 220 Met(S$_4$). With regard to the low general proteolytic activity of newborn dog chymosin, the substitution Asp303 Val relative to calf chymosin may contribute to an explanation of this.

• Korean Journal of Veterinary Service
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• v.34 no.4
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• pp.417-428
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• 2011

Species-specific PCR assay was developed for detection of cattle, sheep, goat, horse, dog, pig, chicken, duck, goose, and turkey using mitochondrial 12S rRNA and 16S rRNA as target genes. Also, an internal positive control was used to detect possible false negatives by using 18S rRNA gene. We designed species-specific primers with amplicon length of 190, 219, 350, 467, 241, 119, 171, 229, 111 and 268 bp for cattle, sheep, goat, horse, dog, pig, chicken, duck, goose, and turkey respectively. The specificity of the primers was tested against the other 10 non-target animal species and a cross-reaction was not observed. We developed two multiplex PCR assays for the simultaneous identification of Korea's major livestock species (cattle, pig, chicken and duck) and poultry species (chicken, duck, goose and turkey) from analogous samples, retaining the same specificity. The limit of detection of the multiplex PCR assay (cattle, pig, chicken and duck) ranged between 1 pg and 0.1 pg of template DNA extracts from raw meat. Applying multiplex PCR assays to DNA extracts from experimental pork/beef and pork/chicken tested raw and heat-treated ($120^{\circ}C$ for 30 min) mixtures respectively, detection limit was 0.1% level beef in pork, pork in beef and chicken in pork and 1.0% level pork in chicken. In conclusion, this assay using gel-based capillary electrophoresis would be very useful in highly sensitive and rapid identification of animal species or ingredients in minced meat and other meat products.

• Korean Journal of Veterinary Service
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• v.31 no.1
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• pp.1-16
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• 2008

Salmonella infections cause the disease in pigs but also some zoonotic Salmonella serotypes can be transmitted to human through swine products, resulting in food poisoning. The objective of this study was to investigate the bacteriological prevalence and detection of invA gene using Salmonella specific polymerase chain reaction (PCR), the epidemiological characteristics related to Salmonella strains cultured from pig samples in Gangwon areas using serotyping, random amplified polymorphic DNA (RAPD) and pulsed field gel electrophoresis (PFGE) methods. During the period of November 2001 through April 2002, 1,174 ileocecal lymph node were collected from the slaughtered pigs raised in 38 farms located in Gangwon province. The samples were submerged in boiling water and macerated in saline and lymph node homogenates were inoculated into Tetrathionate broth with iodine (TTB, Difco, 0.5% iodine was added) for enrichment growth. Then additional tests were performed using several mediums, and suspects were identified by API 20E kit (BioMerieux) and PCR. Of total 1,174 samples from 38 farms, 44 (3.7%) were isolated as Salmonella spp from 13 farms (34.2%). Of 44 isolates, 31 were in Yangyang region, followed by 9 in Goseong, 2 in both Gangneung and Sokcho. However, there was no difference in regional isolation frequency. All isolates have a 521bp amplified product in Salmonella specific PCR with primer invA which encodes in proteins for invasion of epithelial cells. Of 44 recovered serotypes, 23 (52.3%) were S Eingedi, 10 (22.7%) S Schwarzengrund, 9 (20.5%) S Typhimurium, and 2 (4.5%) S Mbandaka. In RAPD analysis, there appeared to be unique bands distinguishing each serotype, although similarities exist between the different serotypes. Four serotypes of 44 Salmonella isolates appeared to fall into 14 different RAPD types. In PFGE analysis, 9 S Typhimurium were tested with XbaI enzyme and SpeI enzyme. The combination of results obtained with two enzymes subdivided the 9 S Typhimurium into 4 PFGE types.