미생물제(Rhodococcus sp. 3-2) 처리에 따른 토양 중 카벤다짐의 분해효과

연제형 ( Jehyeong Yeon ),김현수 ( Hyeon-su Kim ),안재형 ( Jae-hyung Ahn ),한귀환 ( Gui Hwan Han ),오영곤 ( Young Goun Oh ),조일규 ( Il Kyu Cho ),박인철 ( In-cheol Park ) 한국환경농학회 2021 한국환경농학회지 Vol.40 No.4

BACKGROUND: The fungicide of benomyl, a benzimidazole group, has been commonly used for pesticides against fungal diseases in the world. However, benomyl is rapidly hydrolyzed in the environment after using to control plant diseases and has adverse effects by generating carbendazim, which is toxic to plants, humans, and the environment. METHODS AND RESULTS: In this study, the decomposition effect of carbendazim, a degradation product of benomyl was conducted in pot and field after making a prototype of benomyl-degrading microbial agent (BDMA). We found that the carbendazim-degrading microbial agent (CDMA) (10⁵, 10⁶, and 10⁷ cfu/g soil) decomposed carbendazim by 50% or more in all the treatments, compared to the untreated control in the pot tests after four weeks. The effect of 100% decomposition of carbendazim was observed at 7 days after treatment, when the prototype of BDMA was apllied at 10-folds dilution in the field. The decomposition effect at more than 60% and plant growth promoting effect were observed after 7 days of the treatment, compared with the untreated group in the second field experiment,treated with commercially available concentrations of 500-folds and 1,000-folds. CONCLUSION(S): These results might represent that the BDMA would decompose carbendazim effectively, a decomposition product of the fungicide benomyl, remaining in agricultural area, and it could be utilized practically by using a low dilution rate.

쥐 해마에서 글루타메이트의 시간에 따른 변화가 급성 스트레스 연구에 미치는 영향 : 자기공명분광학을 이용한 연구

연제형(Jehyeong Yeon),윤창수(Chang-Soo Yun),황윤호(Yoonho Hwang),백현만(Hyeon-Man Baek),김동윤(DongYoun Kim),한봉수(Bong Soo Han) 대한전자공학회 2021 대한전자공학회 학술대회 Vol.2021 No.6

It was reported that rodents were significantly influenced by stress from experimental procedure and by isoflurane anesthesia. Therefore, in MRS experiments in the hippocampus of normal mice, the concentrations of Glu and tCho were observed to decrease over time. Glu is a potential stress biomarker and its concentration increases with stress. The purpose of this study is to investigate the effect of the time delay that may occur during 1H-MRS experiments on acute stress studies by comparing the control group and the stress group. 20 C57BL/6N male mice were grouped into the control group and the stress group. The stress group mice were exposed to acute constrain stress, and 1H-MRS data were obtained from the left hippocampus, and the difference in the concentration of metabolites due to stress was compared. We found that the statistical significance of the difference in Glu concentration between the two groups changed if there was a difference of about 17 minutes in the data collection time between the two groups. In conclusion, the results of this study suggest that it is necessary to avoid the difference in the timing of data collection between the control and experimental groups in stress studies.

미생물제(Sphingobium sp. Cam5-1) 처리에 따른 토양 중 카두사포스의 분해효과

연제형 ( Jehyeong Yeon ),정준휘 ( Joon-hui Chung ),최한석 ( Han Suk Choi ),고영준 ( Young-joon Ko ),김다연 ( Dayeon Kim ),안시현 ( Sihyun An ),안재형 ( Jae-hyung Ahn ),한귀환 ( Gui Hwan Han ),원항연 ( Hang-yeon Weon ) 한국환경농학회 2023 한국환경농학회지 Vol.42 No.4

Cadusafos, an organophosphorus insecticide, has been commonly used against various pests worldwide. Organophosphorus pesticides have shorter half-lives and lower toxicities than organochlorine pesticides. However, excessive use of Cadusafos can increase pest resistance and issues with acetylcholine biomagnification, potentially resulting in human toxicity. In this study, we investigated the effect of a Cadusafos-degrading microbial agent (CDMA) prepared using Sphingobium sp. Cam5-1, which was previously reported to effectively degrade residual Cadusafos in soil. Experiments were conducted under both controlled laboratory and greenhouse field conditions. Under laboratory conditions, CDMA (10⁶ cfu/g soil application rate) decomposed 97% of Cadusafos in the soil in the untreated control after 21 days. Additionally, when CDMA (10⁶ cfu/g soil) was mixed with quicklime, 99% of Cadusafos was decomposed within 3 days. Under greenhouse field conditions, the combined effect of CDMA (10⁶ cfu/g soil) and quicklime was not observed. However, CDMA (10⁶ cfu/g soil) application alone was capable of decompos- ing 91% of Cadusafos after 3 days. These results indicate that CDMA can effectively decompose high residual levels of Cadusafos in soils under field conditions using a low inoculum rate.

Distinct Bacterial and Fungal Communities Colonizing Waste Plastic Films Buried for More Than 20 Years in Four Landfill Sites in Korea

Chung Joon-hui,Yeon Jehyeong,Seong Hoon Je,An Si-Hyun,Kim Da-Yeon,Yoon Younggun,Weon Hang-Yeon,Kim Jeong Jun,Ahn Jae-Hyung 한국미생물·생명공학회 2022 Journal of microbiology and biotechnology Vol.32 No.12

Plastic pollution has been recognized as a serious environmental problem, and microbial degradation of plastics is a potential, environmentally friendly solution to this. Here, we analyzed and compared microbial communities on waste plastic films (WPFs) buried for long periods at four landfill sites with those in nearby soils to identify microbes with the potential to degrade plastics. Fourier-transform infrared spectroscopy spectra of these WPFs showed that most were polyethylene and had signs of oxidation, such as carbon-carbon double bonds, carbon-oxygen single bonds, or hydrogen-oxygen single bonds, but the presence of carbonyl groups was rare. The species richness and diversity of the bacterial and fungal communities on the films were generally lower than those in nearby soils. Principal coordinate analysis of the bacterial and fungal communities showed that their overall structures were determined by their geographical locations; however, the microbial communities on the films were generally different from those in the soils. For the pulled data from the four landfill sites, the relative abundances of Bradyrhizobiaceae, Pseudarthrobacter, Myxococcales, Sphingomonas, and Spartobacteria were higher on films than in soils at the bacterial genus level. At the species level, operational taxonomic units classified as Bradyrhizobiaceae and Pseudarthrobacter in bacteria and Mortierella in fungi were enriched on the films. PICRUSt analysis showed that the predicted functions related to amino acid and carbohydrate metabolism and xenobiotic degradation were more abundant on films than in soils. These results suggest that specific microbial groups were enriched on the WPFs and may be involved in plastic degradation.

Biological Control of Root-Knot Nematodes by Organic Acid-Producing Lactobacillus brevis WiKim0069 Isolated from Kimchi

Hye Jeong Seo,박애란,Seulbi Kim,Jehyeong Yeon,유난희,하상현,장지윤,박해웅,Jin-Cheol Kim 한국식물병리학회 2019 Plant Pathology Journal Vol.35 No.6

Root-knot nematodes (RKNs) are among the most destructive plant-parasites worldwide, and RKN control has been attempted mainly using chemical nematicides. However, these chemical nematicides have negative effects on humans and the environment, thus necessitating the search for eco-friendly alternative RKN control methods. Here, we screened nematicidal lactic acid bacteria (LAB) isolated from kimchi and evaluated their efficacy as biocontrol agents against RKNs. Of 237 bacterial strains, Lactobacillus brevis WiKim0069 showed the strongest nematicidal activity against the second-stage juveniles (J2) of Meloidogyne incognita, M. arenaria, and M. hapla and inhibited the egg hatch of M. incognita. The culture filtrate of WiKim0069 had a pH of 4.2 and contained acetic acid (11,190 μg/ml), lactic acid (7,790 μg/ml), malic acid (470 μg/ml), and succinic acid (660 μg/ml). An artificial mixture of the four organic acids produced by WiKim0069 also induced 98% M. incognita J2 mortality at a concentration of 1.25%, indicating that its nematicidal activity was derived mainly from the four organic acids. Application of WiKim0069 culture filtrate suppressed the formation of galls and egg masses on tomato roots by M. incognita in a dose-dependent manner in a pot experiment. The fermentation broth of WiKim0069 also reduced gall formation on melon under field conditions, with a higher efficacy (62.8%) than that of fosthiazate (32.8%). This study is the first report to identify the effectiveness of kimchi LAB against RKNs and to demonstrate that the organic acids produced by LAB can be used for the RKN management.

Biological Control of Root-Knot Nematodes by Organic Acid-Producing Lactobacillus brevis WiKim0069 Isolated from Kimchi

Seo, Hye Jeong,Park, Ae Ran,Kim, Seulbi,Yeon, Jehyeong,Yu, Nan Hee,Ha, Sanghyun,Chang, Ji Yoon,Park, Hae Woong,Kim, Jin-Cheol The Korean Society of Plant Pathology 2019 Plant Pathology Journal Vol.35 No.6

Root-knot nematodes (RKNs) are among the most destructive plant-parasites worldwide, and RKN control has been attempted mainly using chemical nematicides. However, these chemical nematicides have negative effects on humans and the environment, thus necessitating the search for eco-friendly alternative RKN control methods. Here, we screened nematicidal lactic acid bacteria (LAB) isolated from kimchi and evaluated their efficacy as biocontrol agents against RKNs. Of 237 bacterial strains, Lactobacillus brevis WiKim0069 showed the strongest nematicidal activity against the second-stage juveniles (J2) of Meloidogyne incognita, M. arenaria, and M. hapla and inhibited the egg hatch of M. incognita. The culture filtrate of WiKim0069 had a pH of 4.2 and contained acetic acid (11,190 ㎍/ml), lactic acid (7,790 ㎍/ml), malic acid (470 ㎍/ml), and succinic acid (660 ㎍/ml). An artificial mixture of the four organic acids produced by WiKim0069 also induced 98% M. incognita J2 mortality at a concentration of 1.25%, indicating that its nematicidal activity was derived mainly from the four organic acids. Application of WiKim0069 culture filtrate suppressed the formation of galls and egg masses on tomato roots by M. incognita in a dose-dependent manner in a pot experiment. The fermentation broth of WiKim0069 also reduced gall formation on melon under field conditions, with a higher efficacy (62.8%) than that of fosthiazate (32.8%). This study is the first report to identify the effectiveness of kimchi LAB against RKNs and to demonstrate that the organic acids produced by LAB can be used for the RKN management.

Root-knot nematode ( Meloidogyne incognita ) control using a combination of Lactiplantibacillus plantarum WiKim0090 and copper sulfate

Kim Seulbi,Kim Ho Myeong,Seo Hye Jeong,Yeon Jehyeong,Park Ae Ran,Yu Nan Hee,Jeong Seul-Gi,장지윤,김진철,박해웅 한국미생물·생명공학회 2022 Journal of microbiology and biotechnology Vol.32 No.8

Lactic acid bacteria (LAB) exert antagonistic activity against root-knot nematodes, mainly by producing organic acids via carbohydrate fermentation. However, they have not yet been used for root-knot nematode (Meloidogyne incognita) control owing to a lack of economic feasibility and effectiveness. In this study, we aimed to isolate organic acid-producing LAB from kimchi (Korean traditional fermented cabbage) and evaluated their nematicidal activity. Among the 234 strains isolated, those showing the highest nematicidal activity were selected and identified as Lactiplantibacillus plantarum WiKim0090. Nematicidal activity and egg hatch inhibitory activity of WiKim0090 culture filtrate were dose dependent. Nematode mortality 3 days after treatment with 2.5% of the culture filtrate was 100%, with a 50% lethal concentration of 1.41%. In pot tests, the inhibitory activity of an L. plantarum WiKim0090-copper sulfate mixture on gall formation increased. Compared to abamectin application, which is a commercial nematicide, a higher control value was observed using the WiKim0090-copper sulfate mixture, indicating that this combination can be effective in controlling the root-knot nematode.

Complete Genome Sequence of Massilia sp. KACC 81254BP Reveals a Potential for Degrading Polyhydroxyalkanoates

An Sihyun,Cho Gyeongjun,Ahn Jae-Hyung,Weon Hang-Yeon,Kim Dayeon,Ko Young-Joon,Yeon Jehyeong,Chung Joon-hui,Choi Han Suk,Heo Jun 한국미생물·생명공학회 2024 한국미생물·생명공학회지 Vol.52 No.1

제주도매립지에서분리된 Massilia strain KACC 81254BP 는생분해성플라스틱폴리하이드록시알카노에이트(PHA)를분해할수있다. 이균주의유전체는 5,028,452 bp의원형염색체로구성되어있으며, G+C 함량은 64.6%이다. 이유전체는 PHB depolymerase를포함한 4,513개유전자가확인되었다. 이유전체는신호전달과아미노산수송등대사와관련한다양한유전자를포함하고있다. 이연구는 Massilia sp. KACC 81254BP의폴리에스터 플라스틱 분해 효소와 관련된 유전학적 정보를 제공한다. Massilia sp. KACC 81254BP, isolated from a landfill on Jeju Island, Republic of Korea, possesses the capability to degrade polyhydroxyalkanoates (PHAs). The genomic analysis of strain KACC 81254BP consists of a circular chromosome comprising 5,028,452 base pairs with a DNA G+C content of 64.6%. This complete genome consists of a total of 4,513 genes, including those encoding the PHA degradation enzyme (PhaZ). This study offers valuable genomic insights into the enzymes responsible for degrading polyester plastics.