Streptomyces has been reported to produce various secondary metabolites which have the potential to become environmentally safe insecticides. In this study, 1,274 streptomyces culture filtrates were screened for their JHAN activity in order to identify novel insecticidal compounds. 34 isolates with high levels of JHAN activity were selected, and their insecticidal activities were tested against Plutella xylostella larvae. Among them, IMBL-263 which was revealed to be Streptomyces anulatus by 16s rRNA sequencing showed the highest insecticidal activity. Also, systemic activities of secondary metabolites extracted from the S. anulatus on plant, Brassica napus, were investigated. These results suggested that secondary metabolites from the S. anulatus might be useful for development of novel environmentally benign insecticides.

Beet armyworm, Spodoptera exigua, is known to be hard-to-kill pest by having high resistance to insecticides and its control is intensely dependent on fewer insecticides. In this study, the ethyl acetate extract of Streptomyces sp. was evaluated to find novel insecticidal agents against S. exigua. In order to determine the identity of insecticidal compounds, the crude ethyl acetate extract was fractionated based on the TLC profiling and bioassay-guided monitoring. These results indicated that the non-polar fraction have high level of insecticidal activity against second instars of S. exigua. These findings suggested that secondary metabolites produced by Streptomyces sp. could be considerable potential resources as novel insecticidal formulation candidates.

지난 18년간(2000~2018년 3월) 검역현장에서 검출된 해충의 종류는 1,980종이다. 이중 딱정벌레목은 전체의 42.6% (곤충은 1,707종으로 86.2%)로 검역적으로 매우 중요하며, 여기에서 가는납작벌레과(Silvanidae)는 딱정벌레목 머리대 장상과에 포함되고, 이들의 검출 종은 21종, 횟수는 15,516회로 가장 많은 비율을 차지한다. 최근 18년간 검출률 결과 Ahasverus sdvana(쌀머리대장)로 6,404회로 가장 많이 검출되었으며, Slivanus didentatus(두니가는납작벌레)는 6,225회, Oryzaephilus surinamensis(머리대장가는납작벌레)는 1,123회, Oryzaephilus mercator(곡물가는납작벌레)는 415 회의 검출률을 보여준다. 가는납작벌레과는 딱정벌레목중 가장많은 검출률을 보이는 과로 검역현장에서 매우 중요한 과에 속한다. 본 연구는 검역과정에서 검출되는 가는납작벌레과 곤충 중 검역현장에서 최초로 발견된 Monanus 속의 한 종을 발견하여 보고 한다.

태양농장은 1982년 누에고치 농사로 시작된 대한민국 대표 곤충산업 선도 기업 중 하나로서 경상북도 영덕에 소재하고 있다. 태양농장에 대한 개략적인 소개, 온라인 마케팅 현황, 농장 내 사육공정의 소개 및 부가가치 창출방안을 소개 하고자 한다. 동충하초 재배 과정의 초기 먹이 수급 및 누에사육 과정, 접종, 건조, 동충하초 재배 및 수확과정을 제시한다. 우리 농업의 전망과 성공 노하우, 수요창출기법 양잠 산업의 전망 등을 제시한다.

The aim of this study was to isolate and identify marine bacterium with anti-methicillinresistant Staphylococcus aureus (MRSA) activity, and to purify the anti-MRSA compound, as well as to determine its activity and synergistic effects. Among the marine bacteria isolated in this study, the YJ-1 isolate had the strongest anti-MRSA activity. The YJ-1 isolate was identified on the basis of its biochemical characteristics and an analysis of 16S rRNA gene sequences. The YJ-1 isolate showed over 99.2% homology with Pseudomonas stutzeri, and was designated as a Pseudomonas sp. YJ-1. The optimal culture conditions were 25℃ and initial pH 7.0. For the purification of the anti-MRSA compounds, the YJ-1 was cultured in Pa PES-II medium, and the culture filtrates were extracted by ethyl acetate, hexane, and 80% MeOH. The 80% MeOH fraction was separated by a C18 ODS column, silica gel chromatography and a reverse phase HPLC, to yield three anti-MRSA agents, the MR1, MR2, and MR3 compounds. When the MR1 compound of 250 μg mL-1 concentration was applied to the MRSA cells, over 95% of bacterial cells was killed within 48 hr. Compared with vancomycin and ampicillin, the MR1 compound showed significant anti-MRSA activity. In addition, the anti-MRSA activity was increased by dose and time dependent manners. Furthermore, the combination of an MR1 compound with vancomycin produced a more rapid decrease in the MRSA cells than did the MR1 compound alone. Taken together, our results suggest that the Pseudomonas sp. YJ-1 and its anti-MRSA compounds could be employed as a natural antibacterial agent in MRSA infections.

The oriental fruit fly, Bactrocera dorsalis (Hendel), has potential of serious damage to various vegetables or fruits,especially genus of Citrus, such as mandarin orange and tangerine in Korea, where its larvae do damages. Animal andPlant Quarantine Agency of Korea and Animal Systematics Laboratory of Kunsan National University have collected thesamples of oriental fruit fly in East Asian countries, Vietnam, Philippines, Myanmar, China, Cambodia, India, Nepal andLaos. To confirm genetic differences and structure of B. dorsalis population samples collected from those countries, weanalyzed 192 individuals from 28 locations over 7 countries using 15 microsatellite loci. In total samples, number ofdifferent alleles, number of effective alleles and Shannon's Information Index were 6.421±0.364 (standard error, SE), 3.664±0.137(SE) and 0.902±0.030 (SE), respectively. Grand means (±SE) of observed and expected heterozygosity over all loci andpopulations were 0.534 (±0.018) and 0.597 (±0.017), respectively. Among all populations, Fst values ranged from 0.016to 0.705 with averaging 0.194 (±0.026).

The objectives of this study are to examine the genetic variation and the origin elucidation in oriental fruit flies (Diptera:Tephritidae) using DNA barcode, in prepartion for their future introductions into Korea. About 1,600 specimens of B.dorsalis sp. complex and B. correcta were collected from 10 countries, the Indochina peninsula, the Philippines, Taiwanand South China. A total of 182 cytochrome c oxidase I (COI) sequences were obtained and aligned from these regionalspecimens. Three chinese sequences from the GenBank reference were also included. Six hundreds base pair fragmentswere aligned and trimmed and used for a barcode. The phylogenetic tree was generated using the neighbor-joining methodwith 1,000 bootstrap replicates. There were two distinct groups in the phylogenetic tree, Bactrocera dorsalis sp. complexand B. correcta. Three specimen, intercepted in the hand-carried mango at the airport inspection and collected in the confiscatedmango, smuggled from Vietnam were included for a test. The DNA sequences from the airport were 100% identical toone of various Vietnam specimens, and that from the confiscated mango was mostly similar to those of Vietnam, suggestingthe usefulness of the barcode for elucidating the origin of oriental fruit fly.

갈색날개매미충 난기생봉은 2015년 9월 구례지역에서 최초 발견되어 검정알벌과의 Telenomus속으로 추정되고있다. 본 연구에서는 갈색날개매미충 난기생봉의 발생분포 및 기생률을 조사하기 위해 갈색날개매미충 발생지역에서2016년 8월부터 10월 사이 난괴를 채집하였다. 전국 21개 시군지역을 조사한 결과, (경기)안성, (충북)괴산, (충남)청양,부여, 공주, (경남)하동, 진주, (전북)전주, 임실, 남원, 진안, (전남)순천, 구례와 광주광역시 14개 지역에서 난기생봉을확인하였다. 기생률은 지역별, 수종별 차이를 보였다. 순천의 층층나무와 복숭아나무에서 약 55%와 44%로 가장높았으며 구례의 두충나무와 때죽나무에서 약26%와 21%로 두 번째로 높게 조사되었다.

장수풍뎅이와 흰점박이꽃무지는 국내에서 상업적으로 이용되는 대표적인 부식성 곤충이다. 부식성 곤충을 사육할때 발생하는 응애류는 영양분이 많은 발효톱밥, 곤충의 먹이나 사체 등을 섭식하며 증식한다. 또한 곤충의 몸에부착하기 때문에 질병을 일으키는 매개체가 될 수 있으며, 상품성을 하락시켜 문제가 되고 있다. 본 연구에서는부식성 곤충 사육 중에 발생하는 대표적인 응애류 Sancassania sp.의 초기생활사를 확인하였다. 실험은 온도 25±1℃,상대습도 50±10%, 24시간 암조건 하에 인큐베이터에서 진행되었으며, 물한천배지(water agar, 2%)가 들어있는 36개의페트리디쉬(3.5cm)에 각 1개 씩 응애의 알을 넣고 3시간 간격으로 관찰하였다. 먹이는 곤충전용젤리를 공급하였다.초기생활사는 알(egg), 유충(larvae), 제1약충(protonymph), 제3약충(tritonymph), 성충(adult) 단계가 확인되었으며, 기간은 알 2.2±0.3일, 유충 1.5±0.1일, 제1약충 0.9±0.1일, 제3약충 1.5±0.2일로 성충까지 약 6.2±0.4일이 소요되었다.

지난 17년간(2000~2016년) 검역현장에서 검출된 해충의 종류는 1,891종이다. 이중 딱정벌레목은 전체의 43.6%(곤충은 1,630종으로 86.2%)로 검역적으로 매우 중요하며, 여기에서 버섯벌레과(Erotylidae)는 딱정벌레목 머리대장상과에포함되고, 이들의 검출률은 1.15%이다. 본 연구는 검역과정에서 검출되는 버섯벌레과의 곤충 중 Dacne 속에 속하는종들에 대하여 검토하였다. 식용 또는 약용 버섯류의 검역과정에서 검출된 종들을 보면, 최근 10년간 검출률이가장 높은 종은 Dacne japonica로 236회 검출되었으며, D. picta는 39회, D. fungorum은 2회 검출되었다. 현재 북한을포함하여 한국 분포종으로 알려진 종은 D. picta, D. fungorum nigrocephala, D. osawai, D. zonaria 4종이며, 2006년북한에서 수입된 버섯에서 검출된 D. japonica는 국내 미기록종으로, 한반도에 분포하는 것으로 새롭게 추가되지만,아직 남한에서의 기록은 없다. 또한, 중국산 버섯류에서 검출된, 신종으로 생각되어지는 Dacne속의 sp. 한 종을발견하여 본 연구를 통해 보고하고자 한다.

Vertical transmission of symbiont is known as the most effective way to deliver their offspring. However, it has beenreported that the bean bug, Riptortus pedestris, acquires its gut symbiont, Burkholderia sp., from its environment (e.g.soil) during the 2nd instar nymphal stage. Nevertheless, it is not unknown how they locate their symbiont. For this reason,dual-choice experiments were conducted in both solitary (a nymph) and group conditions (100 nymphs) to investigatewhether or not R. pedestris has preference on Burkholderia sp. treated or untreated solution in laboratory conditions. Inthese experiments, there was no significant difference in the preference between the two treatments. We are testing inthe Y-tube olfactometer system to evaluate the response of R. pedestris on possible chemical cues from Burkholderia sp..

We experimented to see if the tolerance of Agaricus bisporus to Pseudomonas sp. causing the bacterial brown blotch disease which is causing great damage in the button mushroom cultivation was inherited. There was no correlation between mycelial growth rate and mushroom tolerance to pathogens at each temperature. In the mycelial stage, the strains tolerance to Pseudomonas sp. were not as strong as those of their parents, but they were generally stronger or more tolerance than those of weaker strain (ASI1321). In fruiting body, tolerance was decreased compared to mycelial. In fruiting body, later generations of two strains had similar tolerance, unlike strong or weak tolerance of parental generation. Therefore, browning of fruit body is thought to be caused not only by tolerance but also by various other factors. Especially, the future generation of the strains which were tolerance to Pseudomonas sp. were very weak in the mycelial stage, indicating that the tolerance of the parental generation was inherited to the later generations. The damage of each pathogen was different in mycelium and fruiting body. P. tolaasii caused higher browning than P. agarici in fruit body. P. reactans did not have a significant effect on the mycelium but affected the browning of the fruit bodies. P. agarici had higher mycelial growth inhibitory ability than fruiting body.

Fruiting bodies were degraded themselves by the several glycoside hydrolases after spore releasing from mature fruiting bodies or harvesting. The enzymes involved in autolysis such as glucanase and chitinase have been studied. However, there are almost no information about the relationship between several glycoside hydrolases and autolysis. In this study, we studied to obtain the enzymatic properties of trehalase, and also to get the new information on the relationship between trehalase and autolysis. Crude enzymes were prepared from each fruiting body of Pleurotus sp. (from the immature stage to the autolysis stage) and the trehalase activities were measured at each growth stage. Trehalase activities sharply increased in autolysis stage. Trehalase was partially purified from fruiting bodies of the autolysis stage using various column chromatography and its properties were examined. The optimum temperature was 50 °C and the optimum pH was 4.5. In order to elucidate the localization of trehalase, fruit bodies of the autolysis stage were divided into the stipes and the pileuses, and the each trehalase activity was measured. High trehalase activities were found in the pileuses. Furthermore, in order to elucidate trehalase activities in autolysis more detail, the each fruiting body of autolysis progressing stages was finely divided into the stipes and the pileuses, and their activities were measured. The activities in the outer part of the pileuses were highest at the initial stage of autolysis and the activities shifted from the outer side to the inner side of the pileuses according to the progress of autolysis.

Cyanobacteria Aphanizomenon population is widely distributed in the world, and well known as harmful algae by producing toxins and off-flavor materials, thus belonging to one of the taxa that became more interested in the field of limnoecology. In this study, the frequency, intensity, and duration of Aphanizomenon occurrence were increased with the abnormal drawdown of water level in the winter in Boryeong Reservoir, and the spatial and temporal characteristics of them are compared with each other in the perspective of hydrometeorology (1998 to 2017) and limnology (2010 to 2017). In Korea, Aphanizomenon flourished mainly in high temperature, and the appearance in the low temperature was rare in total five times. The harmful cyanobacteria Aphanizomenon was observed in the low temperature (December to February) in Boryeong Reservoir from 2014, and then reached a maximum value of 2,160 cells mL-1 in January 2017. In addition, the period exceeding 1,000 cells mL-1 at this time was more than 3 months. This was simultaneously associated with abnormal water level fluctuation in the low temperature (<10℃). The large drawdown of water level in the winter season has the potential to promote or amplify the germination and development of harmful algae. Also, subsequent water quality and ecological impacts (e.g., algal toxins and off-flavor substances) need to be considered carefully.