• 한국초지조사료학회지
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• 제34권3호
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• pp.163-168
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• 2014

This study was conducted to investigate the effects of bacterial inoculation (Lactobacillus plantarum) and cutting height on the chemical composition, fermentation characteristics and in vitro dry matter digestibility (IVDMD) in whole crop barley silage. Barley forage (Youngyang hybrid) was harvested at about 27% of dry matter (DM) level at two different cutting height (5 vs. 15 cm). And it was chopped to 5 cm length and treated with or without L. plantarum. Four replicates of each treatment were ensiled into 10 L mini silo (3 kg) for 100 days. After 100 days, bacterial inoculation decreased (p=0.001) DM content, while increased cutting height increased (p=0.002) DM in uninoculated silage. Crude protein (CP) concentration was decreased by increasing height in uninoculated silage (8.84 vs. 8.16) but increased in inoculated silage (8.19 vs. 8.99). Both neutral detergent fiber (NDF) (p<0.011) and acid detergent fiber (ADF) (p<0.004) were decreased by increasing cutting height of forage at harvest. The IVDMD and ammonia-N was increased (p=0.001) by increasing cutting height and inoculation, respectively. Lactic acid bacteria (LAB) was increased (p=0.002) in inoculated silage, but yeast count was decreased (p=0.026) in uninoculated silages. It is concluded that increased cutting height of forage at harvest could be useful to make a fibrous portion with increase of dry matter digestibility of silages.

• 한국식품영양학회지
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• 제33권3호
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• pp.251-256
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• 2020

The aging treatment was applied to Rehmannia glutinosa rhizome (RGR) to improve the digestibility by the enzymatic hydrolysis of undigestible sugars. However, RGR spoils easily during the aging treatment. Thus, the purpose of this study was to investigate the influence of ethanol addition as preservatives on sugars and microbial growth of aged RGR. The RGR was treated with the addition of ethanol (0~10%) at 55℃ for eight days. Reducing, free sugars, and total bacterial counts of RGR with ethanol concentrations were analyzed during the aging periods. The aged RGR with 0-2% ethanol appeared spoiled in appearance, and total bacterial counts of these samples increased from 1.1×10⁵ to 2.2×10⁷ CFU and then decreased again. When treated with 4~10% ethanol, the total bacterial counts of aged RGR decreased by more than 99.9% at eight days. In all samples, reducing and digestible sugars increased, and stachyose decreased by the aging treatment. Sucrose content was highest in the 6% ethanol sample (18.2% at six days). These results indicate that the ethanol addition can be applied to the aging treatment of the RGR for improving qualities (sweetness, digestibility, and microbial growth), and can be considered for the stable production of high quality aged RGR.

• Journal of Crop Science and Biotechnology
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• 제11권4호
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• pp.263-268
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• 2008

Bacterial leaf pustule (BLP) caused by Xanthomonas axonopodis pv. glycines is a serious disease to make pustule and chlorotic haloes in soybean [Glycine max (L). Merr.]. While inheritance mode and map positions of the BLP resistance gene, rxp are known, no sequence information of the gene was reported. In this study, we made five near isogenic lines (NILs) from separate backcrosses (BCs) of BLP-susceptible Hwangkeumkong $\times$ BLP-resistant SS2-2 (HS) and BLP-susceptible Taekwangkong$\times$ SS2-2 (TS) through foreground and background selection based on the four-stage selection strategy. First, 15 BC individuals were selected through foreground selection using the simple sequence repeat (SSR) markers Satt486 and Satt372 flanking the rxp gene. Among them, 11 BC plants showed the BLP-resistant response. The HS and TS lines chosen in foreground selection were again screened by background selection using 118 and 90 SSR markers across all chromosomes, respectively. Eventually, five individuals showing greater than 90% recurrent parent genome content were selected in both HS and TS lines. These NILs will be a unique biological material to characterize the rxp gene.

• 한국수산과학회지
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• 제44권2호
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• pp.104-110
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• 2011

This study was conducted to improve the food functional and sensory food quality of Hizikia fusiforme by the fermentation of lactic acid bacteria. Seven strains of lactic acid bacteria isolated from traditional Korean fermented food were inoculated and cultivated in H. fusiforme water extract. Among them, Lactobacillus brevis LB-20, isolated from Kimchi, was selected for further study by considering the results of bacterial growth, DPPH radical scavenging activity, and sensory evaluation. No significant differences in proximate compositions (moisture, crude protein, crude fat, and crude ash) were observed by the fermentation of L. brevis LB-20. The most dramatical change was the conversion from glutamate to ${\gamma}$-aminobutyric acid (GABA) in H. fusiforme water extract fermented by L. brevis LB-20. The GABA content increased approximately 60-fold after 48 hr of fermentation. The bacterial fermentation also resulted in low-molecularization of the extract. The particle size of the fermented extract became approximately 4-fold smaller than that of the law extract. In addition, the analysis of volatile flavor compounds using GC/MS revealed that the bacterial fermentation dramatically removed off-flavors such as acetaldehyde, haxanal, diallyl disulphide and 1-penten-2-ol in the H. fusiforme extract.

• 한국가금학회지
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• 제32권4호
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• pp.261-268
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• 2005

본 연구는 Ceramic분말의 첨가가 산란계의 생산성, 맹장 및 배설물중 병원성 미생물(E. coli, salmolella)의 수, 배설물 중의 악취물질$(NH_3,\;H_2S,\;VFA)$ 및 난황중 지방산 조성에 미치는 영향을 구명하기 위해서 실시하였다. 총 360수의 34주령의 산란계를 120마리씩 3처리구로 구분하여서 Ceramic 분말 $0.0\%$ (대조구), $0.4\%$ 및 $0.8\%$를 첨가한 사료로 6주 동안의 사양시험을 실시하였다. 결론적으로 34에서 40주령의 산란계 사료에 $0.4\%$의 Ceramics 분말의 첨가는 생산성 향상, 장관내 E. coli 및 Salmonella 수가 감소되어 배설물 중의 $NH_3$ 및 VFA의 발생량 감소 및 난황중의 지방산 조성을 개선시킬 가능성이 인정되었다.

• 한국토양비료학회지
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• 제46권2호
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• pp.117-121
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• 2013

Single or co-inoculation of phosphate solubilizing bacterial and fungal strains (Burkholderia anthina and Aspergillus awamori respectively) was performed separately to assess their synergistic and antagonistic interactions and the potential to be used as bio-inoculants. Co-inoculation was found to release the highest content of soluble phosphorus (1253 ${\mu}g\;ml^{-1}$) into the medium, followed by single inoculation of fungal strain (1214 ${\mu}g\;ml^{-1}$) and bacterial strain (997 ${\mu}g\;ml^{-1}$). However, there was no significant difference between single inoculation of fungal strain and co-inoculation of fungal and bacterial strain in terms of the phosphorous release. The highest pH reduction, organic acid production and glucose consumption were observed in the sole A. awamori inoculated culture medium. According to the plant growth promotion bioassays, co-inoculation of the microbial strains resulted in 21% and 43% higher shoot and root growth of the mung bean seedlings respectively as compared to the respective controls. Therefore, co-inoculation of B. anthina and A. awamori showed better performance in stimulating plant growth than that in inoculation of each strain alone. However, assessment period of the present study being short, we recommend in engaging further experimentation under field conditions in order to test the suitability of the strains to be used as bio-inoculants.

• 미생물학회지
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• 제55권1호
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• pp.80-82
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• 2019

Pseudomonas syringae pv. syringae WSPS007 균주는 대한민국 경상북도 영주시 사과 과원에서 나타난 가지마름병 병징으로부터 2013년 분리되었다. 본 논문에서는 6,238,498 bp(59.04% G+C 함량)인 WSPS007 균주의 전체 염기서열을 보고한다. 전체 지놈은 5,379개의 코딩서열, 65개의 tRNA, 16개의 rRNA 유전자를 가지고 있다. 특히 WSPS007 균주의 전체 염기서열 분석은 냉해와 관련된 빙핵 활성 유전자 클러스터를 중심으로 분석을 수행하였으며, P. syringae pv. syringae 국외 대표 균주인 PssB728a와 유사한 빙핵활성 유전자 구성을 가지고 있는 것으로 나타났다. 따라서 본 논문에서의 염기서열 분석 결과를 바탕으로 경상북도 일원 사과 과원에서 동해로 추정되는 병원균의 원인을 규명하기 위한 기본 자료를 제공하는데 있어서 의의가 있다고 사료된다.

• 한국미생물·생명공학회지
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• 제49권4호
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• pp.587-593
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• 2021

Infertility is a key issue affecting mood and behavior in men. Microorganisms are one of the primary etiological agents that may be associated with infertility. The objective of the present study was to identify bacterial causative agents from the semen of infertile subjects and determine the effect of bacterial infection on sperm quality, as well as determine the susceptibility of these bacteria to drugs. Forty semen samples from 30 infertile patients and 10 fertile individuals were collected. The pH, volume, motility, and concentration of semen were analyzed. The samples were processed and identified by biochemical testing using API identification kits. The antibiotic susceptibility pattern was determined using the disc diffusion method. Abnormal sperm quality was observed. The mean age of the individual and their sperm morphology, concentration, progressive motility, pH level, and pus cell content were 31.9 years, 2.7%, 10.4 million/ml, 27.3%, 8.3, and 5.7, respectively. Among the tested samples, oligoasthenozoospermia was found to show the highest occurrence, at 27/30 samples, followed by teratozoospermia, at 25/30 samples, and asthenozoospermia, at 22/30 samples. Of the tested infertile patients' sperm, 19, 6, and 5 isolates were identified as Escherichia coli, Klebsiella pneumonia, and Staphylococcus epidermidis, respectively. The results also revealed multi-drug resistance in the bacteria. Compared to that shown by the other tested antibiotics, amikacin showed higher activity against all isolated bacteria. However, the bacteria exhibited maximum resistance against gentamicin, cefotaxime, levofloxacin, and ampicillin. In conclusion, leukocytospermia and bacterial infections are possibly responsible for sperm abnormalities. Multi-drug resistant bacteria were detected. Gentamicin, cefotaxime, levofloxacin and ampicillin were shown the highest resistance, while amikacin was the most effective antimicrobial agent against the isolated bacteria.

• 한국미생물·생명공학회지
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• 제50권4호
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• pp.563-573
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• 2022

Xanthomonas arboricola pv. juglandis (Xaj) is a globally important bacterial pathogen of walnut trees that causes substantial economic losses in commercial walnut production. Although prophages are common in bacterial plant pathogens and play important roles in bacterial diversity and pathogenicity, there has been limited investigation into the distribution and function of prophages in Xaj. In this study, we identified and characterized 13 predicted prophages from the genomes of 12 Xaj isolates from around the globe. These prophages ranged in length from 11.8 kb to 51.9 kb, with between 11-75 genes and 57.82-64.15% GC content. The closest relatives of these prophages belong to the Myoviridae and Siphoviridae families of the Caudovirales order. The phylogenetic analysis allowed the classification of the prophages into five groups. The gene constitution of these predicted prophages was revealed via Roary analysis. Amongst 126 total protein groups, the most prevalent group was only present in nine prophages, and 22 protein groups were present in only one prophage (singletons). Also, bioinformatic analysis of the 13 identified prophages revealed the presence of 431 genes with an average length of 389.7 bp. Prokka annotation of these prophages identified 466 hypothetical proteins, 24 proteins with known function, and six tRNA genes. The proteins with known function mainly comprised prophage integrase IntA, replicative DNA helicase, tyrosine recombinase XerC, and IS3 family transposase. There was no detectable insertion site specificity for these prophages in the Xaj genomes. The identified Xaj prophage genes, particularly those of unknown function, merit future investigation.

• 한국축산식품학회지
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• 제44권2호
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• pp.372-389
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• 2024

This study investigated the efficacy of ultraviolet-C (UV-C) irradiation in enhancing the quality of raw bovine milk by targeting microbial populations and lipid peroxidation, both of which are key factors in milk spoilage. We categorized the raw milk samples into three groups based on initial bacterial load: low (<3 Log 10 CFU/mL), medium (3-4 Log 10 CFU/mL), and high (>4 Log 10 CFU/mL). Using a 144 W thin-film UV-C reactor, we treated the milk with a flow rate of 3 L/min. We measured the bacterial count including standard plate count, coliform count, coagulase-negative staphylococci count, and lactic acid bacteria count and lipid peroxidation (via thiobarbituric acid reactive substances assay) pre- and post-treatment. Our results show that UV-C treatment significantly reduced bacterial counts, with the most notable reductions observed in high and medium initial load samples (>4 and 3-4 Log 10 CFU/mL, respectively). The treatment was particularly effective against coliforms, showing higher reduction efficiency compared to coagulase-negative staphylococci and lactic acid bacteria. Notably, lipid peroxidation in UV-C treated milk was significantly lower than in pasteurized or untreated milk, even after 72 hours. These findings demonstrate the potential of UV-C irradiation as a pre-treatment method for raw milk, offering substantial reduction in microbial content and prevention of lipid peroxidation, thereby enhancing milk quality.