• The Plant Pathology Journal
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• 제34권6호
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• pp.459-469
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• 2018

Plants and microorganisms (microbes) use information from chemicals such as volatile compounds to understand their environments. Proficiency in sensing and responding to these infochemicals increases an organism's ecological competence and ability to survive in competitive environments, particularly with regard to plant-pathogen interactions. Plants and microbes acquired the ability to sense and respond to biogenic volatiles during their evolutionary history. However, these signals can only be interpreted by humans through the use of state-of the-art technologies. Newly-developed tools allow microbe-induced plant volatiles to be detected in a rapid, precise, and non-invasive manner to diagnose plant diseases. Beside disease diagnosis, volatile compounds may also be valuable in improving crop productivity in sustainable agriculture. Bacterial volatile compounds (BVCs) have potential for use as a novel plant growth stimulant or as improver of fertilizer efficiency. BVCs can also elicit plant innate immunity against insect pests and microbial pathogens. Research is needed to expand our knowledge of BVCs and to produce BVC-based formulations that can be used practically in the field. Formulation possibilities include encapsulation and sol-gel matrices, which can be used in attract and kill formulations, chemigation, and seed priming. Exploitation of biogenic volatiles will facilitate the development of smart integrated plant management systems for disease control and productivity improvement.

• The Plant Pathology Journal
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• 제21권1호
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• pp.7-12
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• 2005

Plant growth-promoting rhizobacteria (PGPR) are a wide range of root-colonizing bacteria with the capacity to enhance plant growth and control plant pathogens. Here we review recent progress that indicate some PGPR strains release a blend of volatile organic compounds (VOCs) that promote growth in Arabidopsis seedlings and induce resistance against Erwinia carotovora subsp. carotovora. In particular, the volatile components 2,3-butanediol and acetoin released exclusively from the PGPR strains triggered the greatest level of growth promotion and induced systemic resistance. Pharmacological applications of 2,3-butanediol promoted the plant growth and induced resistance, while bacterial mutants blocked in 2,3-butanediol and acetoin synthesis was devoid of growth-promotion and induced resistance capacities. The results suggested that the bacterial VOCs play a critical role in the plant growth promotion and induced resistance by PGPR. Using transgenic and mutant lines of Arabidopsis, we provide evidences that the signal pathway activated by volatiles from one PGPR strain is dependent on cyto-kinin activation for growth promotion and dependent on an ethylene-signaling pathway for induced pathogen resistance. This discovery provides new insight into the role of bacterial VOCs as initiators of both plant growth promotion and defense responses in plants.

• Asian-Australasian Journal of Animal Sciences
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• 제28권9호
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• pp.1362-1370
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• 2015

This study was performed to investigate the effect of different levels of dietary crude protein (CP) on composition of odorous compounds and bacterial communities in pig manure. A total of 48 male pigs (average initial body weight 45 kg) fed diets containing three levels of dietary CP (20%, 17.5%, and 15%) and their slurry samples were collected from the pits under the floor every week for one month. Changes in composition of odorous compounds and bacterial communities were analyzed by gas chromatography and 454 FLX titanium pyrosequencing systems, respectively. Levels of phenols, indoles, short chain fatty acid and branched chain fatty acid were lowest (p<0.05) in CP 15% group among three CP levels. Relative abundance of Bacteroidetes phylum and bacterial genera including Leuconostoc, Bacillus, Atopostipes, Peptonphilus, Ruminococcaceae_uc, Bacteroides, and Pseudomonas was lower (p<0.05) in CP 15% than in CP 20% group. There was a positive correlation (p<0.05) between odorous compounds and bacterial genera: phenol, indole, iso-butyric acid, and iso-valeric acid with Atopostipes, p-cresol and skatole with Bacteroides, acetic acid and butyric acid with AM982595_g of Porphyromonadaceae family, and propionic acid with Tissierella. Taken together, administration of 15% CP showed less production of odorous compounds than 20% CP group and this result might be associated with the changes in bacterial communities especially whose roles in protein metabolism.

• 한국축산식품학회지
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• 제34권5호
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• pp.638-646
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• 2014

The effects of two levels (1.4 vs 2.8%) of fresh garlic on lipid oxidation and microbial growth in pork patties were evaluated. Hunter color (L, a, b), pH, thiobarbituric acid reactive substances (TBARS), oxidative volatile compounds, total bacteria and Enterobacteriaceae in the pork patties with or without fresh garlic were measured during storage at $4^{\circ}C$. Addition of fresh garlic decreased redness (a), while increased pH and yellowness (b) values of the fresh pork patties were observed, regardless of the levels added. The TBARS values of the pork patties were increased with the addition of fresh garlic (p<0.05). Similar results were observed in oxidative volatile compounds. A total of 13 volatile compounds were detected in the patties (5 sulfur-containing compounds, including allyl mercaptan, allyl methyl sulfide, diallyl sulfide, methyl-(E)-propenyl-disulfide, and diallyl disulfide, and the 8 other oxidative compounds, including 1-pentanol, hexanal, 1-hexanol, heptanal, (E)-2-heptenal, 1-octen-3-ol, (E)-2-octenal and nonanal). Fresh garlic accelerated development of oxidative products in the pork patties, especially hexanal and the total oxidative volatile compounds. However, the addition of 1.4 and 2.8% of fresh garlic inhibited the growth of total bacteria and Enterobacteriaceae, indicating low total bacterial counts and Enterobacteriaceae than the controls.

• 원예과학기술지
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• 제32권4호
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• pp.558-570
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• 2014

This study was conducted to compare the volatile flavor compounds found in the leaves of 15 taxa of Korean native Chrysanthemum species. The volatile flavor compounds from the taxa were collected using a simultaneous steam distillation and extraction technique and were analyzed using gas chromatography/mass selective detector (GC/MSD). A total of 45 volatile flavor compounds were identified with six functional groups: 14 alcohols, 4 ketones, 19 hydrocarbons, 5 esters, 2 acids, and 1 aldehyde. The main functional group in 15 taxa of Chrysanthemum species was alcohols, accounting for 28.7% of volatile flavor compounds, followed by ketones (21.2%) and hydrocarbons (13.2%). Camphor, which is known for its antimicrobial properties, was the most abundant volatile compound (30%) in C. zawadskii ssp. latilobum and var. leiophyllum. In particular, C. indicum subspecies and C. boreale contained ${\alpha}$-thujone, which has outstanding anti-bacterial, anti-cancer, anti-inflammatory, anti-ulcer, and anti-diabetic efficacies. C. indicum var. albescens could be used in perfumes, since it showed 21 times more camphene than C. indicum. In addition, C. indicum var. acuta contained a fairly high content of 1,8-cineole, which has an inhibitory effect on mutagenesis. C. lineare contained only pentadecanoic acid compounds, whereas other taxa hexadecanoic acids. Overall, the Korean native Chrysanthemum species had considerable variation in volatile flavor compounds in their leaves. This study provides a good indication of specific potential use for various applications.

• The Plant Pathology Journal
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• 제38권2호
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• pp.115-130
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• 2022

Though information exists regarding the pathogenesis of the shot-hole disease (SH) in flowering cherry (FC), there has been a lack of research focusing on SH management. Therefore, here, we investigated the inhibitory activities of antagonistic bacteria against SH pathogens both in vitro and in vivo as well as their biochemical characteristics and bioactive compounds. Two biosurfactant-producing bacterial antagonists, identified as Bacillus velezensis strains JCK-1618 and JCK-1696, exhibited the best effects against the growth of both bacterial and fungal SH pathogens in vitro through their cell-free culture filtrates (CFCFs). These two strains also strongly inhibited the growth of the pathogens via the action of their antimicrobial diffusible compounds and antimicrobial volatile organic compounds (VOCs). Crude enzymes, solvent extracts, and biosurfactants of the two strains exhibited antimicrobial activities. Liquid chromatography/electrospray ionization time-of-flight mass spectrometric analysis of the partially purified active fractions revealed that the two antagonists produced three cyclic lipopeptides, including iturin A, fengycin A, and surfactin, and a polyketide, oxydifficidin. In a detached leaf assay, pre-treatment and co-treatment of FC leaves with the CFCFs led to a large reduction in the severity of the leaf spots caused by Epicoccum tobaicum and Bukholderia contaminans, respectively. In addition, the two antagonists produced indole-3-acetic acid, siderophore, and a series of hydrolytic enzymes, along with the formation of a substantial biofilm. To our knowledge, this is the first report of the antimicrobial activities of the diffusible compounds and VOCs of B. velezensis against the SH pathogens and their efficiency in the biocontrol of SH.

• Molecules and Cells
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• 제45권7호
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• pp.502-511
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• 2022

Bacterial volatile compounds (BVCs) exert beneficial effects on plant protection both directly and indirectly. Although BVCs have been detected in vitro, their detection in situ remains challenging. The purpose of this study was to investigate the possibility of BVCs detection under in situ condition and estimate the potentials of in situ BVC to plants at below detection limit. We developed a method for detecting BVCs released by the soil bacteria Bacillus velezensis strain GB03 and Streptomyces griseus strain S4-7 in situ using solid-phase microextraction coupled with gas chromatography-mass spectrometry (SPME-GC-MS). Additionally, we evaluated the BVC detection limit in the rhizosphere and induction of systemic immune response in tomato plants grown in the greenhouse. Two signature BVCs, 2-nonanone and caryolan-1-ol, of GB03 and S4-7 respectively were successfully detected using the soil-vial system. However, these BVCs could not be detected in the rhizosphere pretreated with strains GB03 and S4-7. The detection limit of 2-nonanone in the tomato rhizosphere was 1 µM. Unexpectedly, drench application of 2-nonanone at 10 nM concentration, which is below its detection limit, protected tomato seedlings against Pseudomonas syringae pv. tomato. Our finding highlights that BVCs, including 2-nonanone, released by a soil bacterium are functional even when present at a concentration below the detection limit of SPME-GC-MS.

• 대한환경공학회지
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• 제29권6호
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• pp.678-683
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• 2007

휘발성 유기화합물(VOCs)을 제거하기 위해 고안된 미생물 반응기에서 TDB-4로 명명된 톨루엔 분해 세균을 분리하였다. 16S rRNA 유전자 분석을 통하여 TDB-4는 Pseudomonas 속에 속하는 것으로 판명되었다. 이 세균에 의한 톨루엔 분해 특성을 관찰하기 위하여 세균의 농도와 기질인 톨루엔 농도를 변화시키면서 톨루엔의 분해도를 측정하였다. 낮은 농도인 $10{\mu}mole$의 톨루엔을 기질로 공급하였을 때 보다 $50{\mu}mole$의 톨루엔을 주었을 때 세균 성장과 톨루엔 분해 속도가 높았다. 하지만, $100{\mu}mole$의 톨루엔을 공급한 시료에서는 낮은 농도의 시료보다 세균 성장과 분해속도가 낮은 것으로 관찰되었다. 이러한 결과는 높은 톨루엔 농도에서 TDB-4의 성장 및 톨루엔 분해도가 저해받는 것을 의미한다. 다른 VOC에 대한 TDB-4의 분해능을 관찰한 결과, styrene, benzene 및 xylene의 분해능이 뛰어난 것으로 나타났다. 이러한 실험결과는 VOC를 제거하기 위해 고안된 미생물 반응기의 성능을 향상시키기 위한 운전조건의 최적화에 활용될 수 있을 것으로 사료된다.

• 식물병연구
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• 제28권1호
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• pp.1-18
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• 2022

휘발성물질은 자연에서 어디에나 존재한다. 생태학적으로 식물이나 미생물이 생산하는 휘발성물질은 식물-미생물이나 미생물-미생물간 대화에 중요한 역할을 수행한다. 정족수 인식신호는 세균과 세균 사이의 짧은 거리에서만 영향을 미치지만 휘발성물질은 20 cm 이상의 거리에서 생명체 간 신호전달이 가능하다. 이번 리뷰에서는 휘발성물질을 이용한 식물병진단과 진균, 세균, 바이러스병의 생물적방제의 최신 결과를 소개하였다. 더불어 이러한 휘발성물질을 농업에 적용하기 위한 다양한 기술들도 소개하였다. 휘발성물질의 캡슐화와 서방형 제제화 그리고 바이오나노 융합기술은 기존의 휘발성 물질 적용 한계를 넘게 해 줄 것이다. 종합하면 휘발성물질은 식물병을 효과적으로 방제할 수 있는 새로운 방법이다. 이번 리뷰를 통하여 농민들과 젊은 연구자들이 휘발성물질에 대한 이해를 높이고 향기농업으로의 전환을 앞당기는 계기가 되기를 희망한다.

• Journal of Microbiology and Biotechnology
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• 제26권4호
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• pp.648-658
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• 2016

Preservation of fresh algae plays an important role in algae seed subculture and aquaculture. The determination and examination of the changes of cell viability, composition, and bacterial species during storage would help to take suitable preservation methods to prolong the preservation time of fresh algae. Nostoc flagelliforme is a kind of edible cyanobacterium with important herbal and dietary values. This article investigated the changes of bacterial species and biochemical characteristics of fresh N. flagelliforme concentrate during natural storage. It was found that the viability of cells decreased along with the storage time. Fourteen bacteria strains in the algae concentrate were identified by PCR-DGGE and were grouped into four phyla, including Cyanobacteria, Firmicutes, Proteobacteria, and Bacteroidetes. Among them, Enterococcus viikkiensis may be a concern in the preservation. Eleven volatile organic compounds were identified from N. flagelliforme cells, in which geosmin could be treated as an indicator of the freshness of N. flagelliforme. The occurrence of indole compound may be an indicator of the degradation of cells.