• 한국균학회지
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• 제51권4호
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• pp.397-403
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• 2023

Wilt symptoms were observed in basil (Ocimum basilicum) plants grown in a vinyl greenhouse located in Gokseong, Korea, during crop disease surveys conducted in August 2022. The symptoms appeared as wilting of the plants and brown to dark brown longitudinal streaks on the stems at or above the soil line. The disease incidence among the plants in the vinyl greenhouse was 5-20%. Six isolates of Fusarium sp. were obtained from stem lesions and identified as Fusarium oxysporum species complex based on their morphological characteristics. Among the isolates, two were used for phylogenetic analysis and pathogenicity test. Phylogenetic analysis revealed that these isolates belonged to F. oxysporum. Pathogenicity of the isolates was confirmed through artificial inoculation test. The symptoms induced by the isolates were similar to those observed in basil plants in the investigated vinyl greenhouse. This is the first report of F. oxysporum causing Fusarium wilt in basil in Korea.

• 한국식품위생안전성학회지
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• 제36권6호
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• pp.481-487
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• 2021

본 연구는 로메인 상추에서 병원성미생물이 생존과 생육의 특성을 분석하여 안전관리 정보를 확보하고자 실시하였다. 로메인 상추에서 분무 접종한 E. coli O157:H7은 72시간 배양 후 초기균수 보다 2.0 log CFU/g 수준으로 증가하여 생존 및 증식이 가능한 것으로 판단되었다. 상추 잎의 상처 유무에 따른 E. coli O157:H7은 배양 72시간 후 유의적 차이가 없었다. 상추 잎에 인위적인 상처에 내어 E. coli O157:H7을 접종하고 병원균의 분포를 조사한 결과 상처가 없는 상추는 표면이 매끄러워 균이 부착하지 못하거나 균수가 매우 낮았고, 상처가 있는 상추 잎은 거친 표면에 균이 밀집되어 상처를 통해 상추 내부로 침입하는 것으로 판단되었다. 병원성미생물의 상추 추출물 이용 여부는 10-100% 농도에서 배양 24시간 이후에 E. coli O157:H7 8.9 log CFU/mL, L. monocytogenes 8.6 log CFU/mL, P. carotovorum 8.8 log CFU/mL로 나타났다. 이는 병원성미생물과 식물병원균이 유사한 4 log CFU/g 이상의 증가율을 나타내어 미생물이 상추 추출물을 영양원으로 사용할 수 있는 것으로 판단되었다. 상추 추출물 0.1%에서 초기 접종 농도와 비교하여 E. coli O157:H7 2.7, L. monocytogenes 1.3, P. carotovorum 2.9 log CFU/mL 수준으로 증가하였다. 이에 따라 병원성 미생물의 최소생육농도는 0.1%보다 낮은 것으로 판단되었고, 상처를 통해 지속적으로 0.1% 수준의 상추 추출물이 병원성미생물에 제공되면 상추 내부에서도 생존 및 증식이 가능할 것으로 확인하였다.

• 한국균학회지
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• 제48권4호
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• pp.499-503
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• 2020

Clubroot symptoms were frequently observed on the roots of Baecheongchae plants grown in vinyl greenhouses of a farmer located in Yangpyeong area of Korea during a disease survey in June 2019. The incidence of diseased Baecheongchae plants ranged from 30 to 90% in the vinyl greenhouses investigated. Many resting spores were found in the tissue of root galls collected. The resting spores were hyaline and spherical and measured 2.5-4.2 ㎛ in diameter. Three inoculum suspensions of resting spores prepared from the root galls were inoculated to the roots of healthy Baecheongchae plants. All the inoculum suspensions caused clubroot symptoms to appear on the roots of the inoculated Baecheongchae plants. The symptoms on the roots induced by artificial inoculation were similar to those observed in the plants of the vinyl greenhouses during the disease survey. Resting spores of the pathogen were recovered from the root galls of the inoculated plants. Three root gall isolates obtained from the inoculated plants were used for molecular identification. Comparing the isolates to the Plasmodiophora brassicae strains in GenBank, the amplification products demonstrated 100% similarity with the internal transcribed spacer (ITS2) sequences. The clubroot pathogen was identified as P. brassicae according to its morphological, pathological, and molecular characteristics. This is the first report of P. brassicae causing clubroot in Baecheongchae.

• Asian-Australasian Journal of Animal Sciences
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• 제33권8호
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• pp.1292-1300
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• 2020

Objective: To explore feed resources capable of replacing regular poor-quality fodder, this study was conducted to evaluate the effects of additives on the fermentation quality, in vitro digestibility and aerobic stability of mulberry leaves silage. Methods: The mulberry leaves were ensiled either untreated (control) or treated with 1×10⁶ cfu/g fresh matter Lactobacillus plantarum (L), 1% glucose (G), 3% molasses (M), a combination of 1% glucose and Lactobacillus plantarum (L+G), and a combination of 3% molasses and Lactobacillus plantarum (L+M). The fermentation quality and chemical composition were analyzed after 7, 14, 30, and 60 d, respectively. The 60-d silages were subjected to an aerobic stability test and fermented with buffered rumen fluid to measure the digestibility. Results: Inoculating lactic acid bacteria (LAB) resulted in more rapid increase in lactic acid concentrations and decline in pH of mulberry leaves silage as compared control. Higher acetic acid and lower ethanol and ammonia nitrogen concentrations (p<0.05) were observed in the LAB-inoculated silages as opposed to control during ensiling. The LAB-inoculated silages contained lower water-soluble carbohydrates compared with control during the first 14 d of ensiling, and lower neutral detergent fibre (p<0.05) concentrations as compared with non-LAB inoculated silages. Adding molasses alone increased (p<0.05) the digestibility of dry matter (DM). The aerobic stability of mulberry leaves silage was increased by LAB inoculation, whereas decreased by adding glucose or molasses. Conclusion: The LAB inoculation improved fermentation quality and aerobic stability of mulberry leaves silage, while adding glucose or molasses failed to affect the fermentation and impaired the aerobic stability. Inoculating LAB alone is recommended for mulberry leaves especially when ensiled at a relatively high DM.

• 한국식품저장유통학회지
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• 제23권6호
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• pp.797-803
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• 2016

본 연구에서는 전분 및 단백질 분해력이 우수한 토착 발효종균 Aspergillus luchuensis 74-5 및 Aspergillus oryzae 75-2로 제조한 고체종국의 품질 특성을 조사하였다. 액체종국 접종량 5%와 10% 접종하였을 때, pH는 각각 5.78 및 3.85 이하로, 적정산도는 2.12와 8.54 이상, 아미노산도는 1.15 및 2.66 이상으로 균주에 따라 차이를 보였다. 효소활성의 변화는 발효종균에 따라 증감 패턴이 특징적으로 나타났고, 액국 접종량에 따라 A. luchuensis 74-5는 접종량이 증가할수록 ${\alpha}-amylase$와 glucoamylase 활성은 증가하나 acidic protease활성은 감소하였고, A. oryzae 75-2는 5% 접종하였을 때 모든 효소활성이 가장 높게 나타났다. 발효온도는 저온보다 중온(35, $40^{\circ}C$)에서 효소활성이 우수한 것으로 나타났고, 발효시간은 종균에 따라 차이는 있지만 각각 144시간과 120시간일 때 효소활성이 높은 것으로 나타났다. 발효조건에 따른 고체종국의 포자수는 약 $2.0{\times}10^7$, 세균의 오염은 약 $3.0{\times}10^3$으로 나타났으며, 세균에 의한 오염도 저감화 및 효소활성을 유지하기 위하여, 구연산, 종국의 건조법 및 부형제 등의 추가적인 연구가 필요하다.

• 식물병연구
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• 제28권2호
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• pp.108-111
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• 2022

In December 2020, stem and leaf rot symptoms in small-fruited tomato (Solanum lycopersicum) plants were observed in a farmer's vinyl greenhouse located in Pyeongtaek, Gyeonggi Province, Korea. The incidence of diseased plants in the vinyl greenhouse was 2-6%. Seven single-spore isolates of Phoma sp. were obtained from the diseased stems and leaves. All the isolates were identified as Boeremia linicola based on the cultural, morphological and molecular characteristics. Two isolates of B. linicola were tested for pathogenicity on stems and leaves of small-fruited tomato and large-fruited tomato using artificial inoculation. All the tested isolates caused stem and leaf rot symptoms in the inoculated plants. The symptoms were similar to those observed in plants from the vinyl greenhouse investigated. This is the first report of B. linicola causing stem and leaf rot in tomato.

• 식물병연구
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• 제28권3호
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• pp.162-165
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• 2022

Foot rot symptoms were repeatedly observed on plants of deltoid synurus (Synurus deltoides) growing in a field of the Wild Vegetable Research Institute located in Pyeongchang, Korea during disease surveys in July 2020 and June 2021. The symptoms appeared as wilting of the plant leaves, and the plant stems and petioles at or above the soil line turned dark and rotted. The incidence of diseased plants in the field was 5-10%. Five isolates of Phytophthora sp. were obtained from lesions of the diseased plants and investigated for their morphological and molecular characteristics. All the isolates were identified as Phytophthora cryptogea based on the morphological and molecular characteristics. Three isolates of P. cryptogea were tested for pathogenicity on deltoid synurus plants using artificial inoculation. All the tested isolates caused foot rot symptoms on the inoculated plants. The symptoms were similar to those observed in plants from the field investigated. To our knowledge, this is the first report of P. cryptogea causing Phytophthora foot rot in deltoid synurus.

• 한국균학회지
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• 제49권3호
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• pp.413-416
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• 2021

In July 2019, damping-off symptoms of young Fischer's ragwort (Ligularia fischeri) plants were observed in four vinyl greenhouses of a farmer located in Taebaek, Gangwon Province, Korea. This disease occurred in 20-30% of plants in the vinyl greenhouses investigated. Nine isolates of Rhizoctonia sp. were obtained from the diseased plants. All the isolates were identified as Rhizoctonia solani AG-2-2 (IIIB), based on morphological, cultural characteristics, and anastomosis test. Three isolates were used for artificial inoculation test on Fischer's ragwort. Pathogenicity of these isolates was confirmed on the plants with the inoculation tests. Damping-off symptoms observed on the inoculated plants were similar to those observed in the diseased plants in the vinyl greenhouses. This is the first report of R. solani AG-2-2 (IIIB) being the causative agent in damping-off in Fischer's ragwort.

• Journal of Microbiology and Biotechnology
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• 제30권5호
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• pp.668-680
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• 2020

Bacillus velezensis is an important plant growth-promoting rhizobacterium with immense potential in agriculture development. In the present study, Bacillus velezensis Lle-9 was isolated from the bulbs of Lilium leucanthum. The isolated strain showed antifungal activities against plant pathogens like Botryosphaeria dothidea, Fusarium oxysporum, Botrytis cinerea and Fusarium fujikuroi. The highest percentage of growth inhibition i.e., 68.56±2.35% was observed against Fusarium oxysporum followed by 63.12 ± 2.83%, 61.67 ± 3.39% and 55.82 ± 2.76% against Botrytis cinerea, Botryosphaeria dothidea, and Fusarium fujikuroi, respectively. The ethyl acetate fraction revealed a number of bioactive compounds and several were identified as antimicrobial agents such as diketopiperazines, cyclo-peptides, linear peptides, latrunculin A, 5α-hydroxy-6-ketocholesterol, (R)-S-lactoylglutathione, triamterene, rubiadin, moxifloxacin, 9-hydroxy-5Z,7E,11Z,14Z-eicosatetraenoic acid, D-erythro-C18-Sphingosine, citrinin, and 2-arachidonoyllysophosphatidylcholine. The presence of these antimicrobial compounds in the bacterial culture might have contributed to the antifungal activities of the isolated B. velezensis Lle-9. The strain showed plant growth-promoting traits such as production of organic acids, ACC deaminase, indole-3-acetic acid (IAA), siderophores, and nitrogen fixation and phosphate solubilization. IAA production was accelerated with application of exogenous tryptophan concentrations in the medium. Further, the lily plants upon inoculation with Lle-9 exhibited improved vegetative growth, more flowering shoots and longer roots than control plants under greenhouse condition. The isolated B. velezensis strain Lle-9 possessed broad-spectrum antifungal activities and multiple plant growth-promoting traits and thus may play an important role in promoting sustainable agriculture. This strain could be developed and applied in field experiments in order to promote plant growth and control disease pathogens.

• 한국식품위생안전성학회지
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• 제34권6호
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• pp.542-550
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• 2019

농식품과 생산환경에서 대장균 오염여부를 휴대 전화에서 실시간으로 결과를 확인할 수 있는 IoT 기반 스마트 대장균 검출 장치를 개발하였다. 개발된 대장균 검출기는 온도 조절부, UV 램프, 고해상도 카메라 및 검출 여부를 판단할 수 있는 소프트웨어로 구성된 장치이다. 검출기의 성능을 평가하기 위하여 온도, 대장균 검출 시간 및 검출한계를 측정하였는데, 개발 된 장치의 설정 온도와 실제 온도의 차이는 약 1.0℃ 이내 였다. 또한 검출시간은 1CFU / 100 mL일 때 15 시간이었고, 대장균 오염농도가 증가할수록 검출시간이 감소하였다. 개발된 스마트 대장균 검출기를 기구, 장갑, 관개 수, 종자 및 채소를 포함한 다양한 시료에 적용했을 때, 대장균의 검출율은 식품공전법으로 분석하였을 때보다 높았다. 따라서 개발된 대장균 검출기술은 농식품 및 생산환경에서 대장균을 효율적으로 검출할 수 있을 것으로 판단된다.