• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.2
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• pp.106-111
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• 2018

The main objective of this study was to determine the quality of rice straw silage made with various lactic acid bacteria (LAB) during fermentation. Five strains of LAB (Lactobacillus plantarum CMRT, L. leuconostoc mesenteroides M17, L. sakei C11, M5, SP2) were used in this study. With regard to odor, ready-made CMRT (a comparison strain) had the highest value from 10-60 days, followed by M17. The pH level of all silages made with five strains (apart from CMRT) ranged from 4.02 to 4.59. Of these, M17 rapidly lowered the pH value in the silage. Crude protein (CP) content was significantly lower (p < 0.01) in ready-made CMRT compared to the other bacteria. C11 fermentation produced the highest content of silage, with a score of 5.56. Acetic acid and butyric acid were not detected in any of the silage products. The lactic acid levels in silages produced by M17, M5, C11, and SP2 were comparatively higher than that produced by CMRT. The total digestible nutrient (TDN) content levels and relative fees value (RFV) were he highest in the silage of C11 (69.65 and 155.56, respectively), followed by M17. Based on odorl, pH, protein, organic acid, and feed value, we suggest tha the M17 strain is a suitable substitute for CMRT that can be used to generate high quality rice straw silage.

• Korean Journal Plant Pathology
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• v.12 no.4
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• pp.389-394
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• 1996

도열병균, Magnaporthe grisea, 균주간의 유전적 유연관계를 분석하고 그들의 유전에 관한 '기본 정보를 얻고자 DNA polymorphism 분석을 실시하였다. 기주가 다른 도열병 균주들이 공시되었고 cloning에 의해 벼 도열병균 KJ201레이스 균주로부터 생성된 임의 선발 genomic clone들이 공시균주들간의 polymorphism을 밝히기 위해 사용되었던 바 그중 repectitive sequence를 보유한 repeated copy clone 하나가 선발되었다. Clone pMJ6에 의해 밝혀진 repetitive sequence는 Southern hybridization시 벼 분리균주에는 약 30개, 다른 기주 분리균에도 20∼33개의 밴드를 형성하였다. 반면 피 분리균주에는 단지 두 개의 밴드만을 나타내 분리기주가 다른 균주간에 뚜렷한 polymorphism이 존재하였으며 parsimony 분석에서도 역시 아주 먼 cluster를 형성하여 피 분리균은 다른 기주 분리균과 유전적으로 상당히 먼 것으로 추정되었다. 공시균의 genomic DNA를 HindIII로 처리했을 때 pMJ6에 의한 밴드양상은 공시균을 EcoRI으로 처리했을 때의 MGR probe의 밴드 양상과 유사하여 이 repeated copy clone이 도열병균주간의 유전적 유연관계를 분석하는데 MGR 못지않게 유용할 것으로 보인다.

• Microbiology and Biotechnology Letters
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• v.40 no.3
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• pp.190-196
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• 2012

In this study, a total of more than 1,000 bacteria, including 739 species of aerobic bacteria, 80 species of urease producing bacteria and 303 species of photosynthetic bacteria, were isolated from red-pepper field soils located in the Gyeongsan Province of the Republic of Korea. Amongst these, 158 species of aerobic bacteria, 70 species of urease producing bacteria and 228 species of photosynthetic bacteria were found to be auxin producing soil bacteria through quantification analysis with the Salkowski test. The latter groupings were then tested for antifungal activities to ${\beta}$-Glucanase and siderophore using CMC congo red agar and CAS blue agar media. In addition, the selected strains were examined for antifungal activity against various phytopathogenic fungi on PDN agar media. Six strains; BCB14, BCB17, C10, HA46, HA143, and HJ5, were noted for their ability to both produce auxin and act as antifungal substances. 16S rDNA sequence comparison analyses of these six strains identified them as Bacillus subtilis BCB14, B. methylotrophicus BCB17, B. methylotrophicus C10, B. sonorensis HA46, B. subtilis HA143, and B. safensis HJ5.

• The Korean Journal of Mycology
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• v.13 no.2
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• pp.75-78
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• 1985

Mutagenesis of protoplast could serve a great potential tool for improvement of strains and genetics in higher fungi. For the isolation of auxotrophic mutants from protoplasts of Pleurotus ostreatus and Pleurotus florida, viability levels of ultraviolet lights were determined. Seven auxotrophs were obtained from protoplasts irradiating UV to give $0.83{\sim}15%$ survival. The mutants showed a single requirement for each of Arg, Ribo-l, Ribo-2 or Phen for growth. Some of them showed two or three kinds of requirements, Gly Ser, Ade Hypo or Ala Om Tryp for growth.

• Journal of Animal Science and Technology
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• v.49 no.5
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• pp.621-632
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• 2007

The aim of this study was to isolate and characterize bacteriocin-producing bacteria from the intestine of duck to use as probiotics for livestock. A total of 416 strains were isolated from the small intestine and cecum of ducks and 13 isolates were finally selected after determinging inhibitory activity against pathogenic indicators by spot-on-lawn method. The selected strains were identified as Lactobacillus salivarius JWS 58, Lactobacillus plantarum JWS 1354, Pediococcus pentosaceus JWS 939, 7 strains of enterococci, and 3 strains of Escherichia coli. Lact. salivarius JWS 58, Ent. faecium JWS 833, and Ped. pentosaceus JWS 939 showed a strong inhibitory activity against Listeria monocytogenes. E. coli JWS 108 inhibited the growth of E. coli and Staphylococcus aureus. Lact. salivarius JWS 58 strain survived almost 50% in pH 2.5 phosphate buffer for 2 hr. Ped. pentosaceus JWS 939 and Lact. plantarum JWS 1354 showed strong amylolytic activity. These results suggest that a combination of bacteriocins or multispecies probiotics of the selected strains has a strong potential of alternative to antibiotics in livestock production.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.10
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• pp.1481-1487
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• 2016

Lactic acid bacteria showing alginate-degrading and cellulolytic activity were isolated and identified as a starter for seaweed fermentation. A total of 331 strains of lactic acid bacteria isolated from various Korean traditional foods, such as Kimchi, Jeotgal, and Makgeolli, were examined alginate-degrading and cellulolytic activity by the plate assay method. Six strains showed strong alginate-degrading and cellulolytic activity among the isolated 331 strains. Among these six strains, four strains (strain No. 162, 164, 192, and 196) showed probiotic properties (antimicrobial activity, tolerance to simulated gastric juice, artificial bile acid, and NaCl). No. 192 strain (Gram-positive cocci, catalase negative, and homofermentative) showed the best probiotic properties among selected strains and was identified as Enterococcus faecium by 16S rRNA sequencing. Strain No. 192 (E. faecium) showed the best growth and antioxidative activity during seaweed (sea mustard and sea tangle) fermentation for 72 h at $37^{\circ}C$ among the four selected strains.

• The Korean Journal of Mycology
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• v.25 no.1 s.80
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• pp.26-29
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• 1997

Pyrimidine auxotrophic basidiospores of Pleurotus sajor-caju were selected using positive selection method. Wild type basidiospores could not grow on minimal medium containing the pyrimidine analog 5'-fluoro-orotic acid (5'-FOA) whereas pyrimidine auxotrophs grew normally. After treatment of basidiospores with ultraviolet light, a total of 13 pyrimidine auxotrophic basidiospores were isolated among 24 5'-FOA resistant mutants. These mutants require the pyrimidine such as uracil, cytosine, thymine. Mating type group and growth rate of their mutants were determined.

• The Korean Journal of Pesticide Science
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• v.15 no.4
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• pp.495-501
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• 2011

Bacterial strains were isolated from forest soils of Halla mountain, Jeju island in Korea. The soil samples were collected at each altitude of 100m from 1,000 m above sea level. Total 398 strains were isolated and tested for their physiological characteristics of antagonistic and proteolytic activities, and auxin production. Among the isolates, 172 strains were selected as antifungal strains showing antagonistic activity against at least one of 8 plant fungal pathogens (Alternaria alternata, Botrytis cinerea, Collectotrichum acutatum, Fusarium oxysporum, Phytophthora capsici, Pythium ultimum and Sclerotinia sclerotiorum). In addition 203 strains for proteolytic activity and 26 strains for auxin production were characterized for further study. Je28-4 (Rhodococcus sp.) were showed 80% of control value against tomato gray mold in vivo. Thus, it is suggested that soil bacteria isolated from forest soils of Halla mountain can be important sources of bioactive compounds for improving plant growth or promising biocontrol agents.

• The Microorganisms and Industry
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• v.15 no.2
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• pp.40-45
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• 1989

본고에서는 한국과학기술원, 유전공학센터, 미생물자원실에서 3여년간 행했던 토양방선균으로부터 근간으로 기술하고 기술범위는 미생물 Screening을 중심으로 대상물에서 미생물 선발, 배양을 통한 선발, 선발시험 방법 및 신규성 확인 등의 순으로 검토하겠다.

• Horticultural Science & Technology
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• v.31 no.6
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• pp.657-665
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• 2013

A large patch disease caused by Rhizoctonia solani AG2-2 (IV) is a serious problem in Korean lawngrass (Zoysia japonica) sites including golf courses and sports fields in Korea. Antagonistic microorganisms against R. solani AG2-2 (IV) were isolated from various forest and crop soil sources in Southern Korea. Among the 61 isolates, I-009, FRIN-001-1, and YPIN-022 strains showing dramatic inhibition of the mycelial growth of R. solani AG2-2 (IV) in the pairing culture were selected as the most potential antagonistic microorganisms for this study. Based on the 16s RNA sequence comparison, I-009 and FRIN-001-1 isolates were identified as Bacillus spp., while YPIN-022 isolate belongs to the genus Pseudomonas. The greater inhibition (clear) zone between two edges of the selected and pathogenic microbes ranged from 11 to 15 mm in three selections, but the others averaged to 7 mm out of 30 mm distance. In another antifungal test using culture filtrate, those three isolates represented a range of 51.7 to 63.5% suppression potential. The selected isolates also inhibited significantly the stem-segment colonization by R. solani AG2-2 (IV) in vivo test by 28.1%, 43.0%, and 23.7% when inoculated with I-009, FRIN-001-1, and YPIN-022, respectively. The highest antagonistic activity for the large patch disease was demonstrated by the isolate FRIN-001-1, which will be useful for developing a bio-pesticide against Rhizoctonia.