,  , Effect of a new crop protectant ‘Bt-Plus’ on natural enemies was analyzed in this study. Tested natural enemies included two parasitic species of Aphidius colemani and Eretmocerus eremicus, and four predatory species of Harmonia axyridis, Orius laevigatus, Amblyseius swirskii, and Phytoseiulus persimilis. ‘Bt-Plus’ was formulated by combination of three entomopathogenic bacteria (Xenorhabdus nematophila (Xn), Photorhabdus temperata subsp. temperata (Ptt), Bacillus thuringiensis (Bt)) and bacterial metabolite (BM). All three types of ‘Bt-Plus’ showed significantly higher toxicities against fourth instar Plutella xylostella larvae than Bt single treatment. Two types of bacterial mixtures (‘Xn+Bt’ and ‘Ptt+Bt’) showed little toxicity to all natural enemies in both contact and oral feeding assays. However, ‘BM+Bt’ showed significant toxicities especially to two predatory mites of A. swirskii and P. persimilis. The acaricidal effects of different bacterial metabolites were evaluated against two spotted spider mite, Tetranychus urticae. All six BM chemicals showed significant acaricidal effects. The BM mixture used to prepare ‘Bt-Plus’ showed a high acaricidal activity with a median lethal concentration at 218.7 ppm (95% confidence interval: 163.2 - 262.3). These toxic effects of bacterial metabolites were also proved by cytotoxicity test against Sf9 cells. Especially, benzylideneacetone, which was used as a main ingredient of ‘BM+Bt’, showed high cytotoxicity at its low micromolar concentration.

해충저항성 Bt벼와 낙동벼의 미꾸리(Misgurnus anguillicaudatus) 와 잉어(Cyprinus carpio)에 대한 급성독성시험을 실시한 결과 48시간 및 96시간-LC50은 1,000mg/L 이상으로 나타났다. 48시간 및 96시간 무영향농도(NOEC)는 1,000mg/L이었다. 급성독성 시험기간 중 해충저항성 Bt벼와 낙동벼간의 pH, DO, 수온, 체중 및 전장에 대한 유의적인 결과는 나타나지 않았다.

Bacillus thuringiensis (Bt) is characterized by its ability to synthesize crystal toxins and also able to produce bacteriocins such as thuricin, tochicin, entomocin and bacthuricin. The present work, for the first time, describes the biological activity of bacteriocins from B. thuringiensis subsp. cameroun (Btc). Supernatant which was produced from a liquid culture of Btc had antimicrobial activity against various Bt subspecies, ending up to making a inhibition zone on an agar medium. A significant reduction in antimicrobial activity was observed when the supernatant was exposed to heat at 47~50°C for 15 min. Proteins were separated from the supernatant by a fast protein liquid chromatography (FPLC) given the thermal instability. A group of FPLC fractions had antimicrobial activity against Bt subsp. palmanyolensis, israelensis, 1-3, morrisoni, toguchini and kurstaki and a Bacillus. cereus ATCC21768, ATCC14579 and NRRLB-569. Interestingly, when the supernatant was individually incorporated into the liquid cultures of Bt subsp. israelensis (Bti) and mogi (Btm) with mosquitocidal activity, a vegetative cell growth was observed only in the Btm culture 10 h post-incubation. A possible recovery of vegetative Btm cell growth was observed, compared to a control without the supernatant. These results suggest that Btc produced proteinous antimicrobial substances, one of which may be used as a selection marker to separate Btm after possibly conjugating the two mosquitocidal strains.

새만금간척지역에서 재배되는 작물별로 왕담배나방(Helicoverpa armigera)의 피해와 발생소장을 조사한 결과, 왕담배나방이 가해하는 작물은 세스바니아, 헤어리벳치, 옥수수, 감자, 유채 등 이었으며, 피해는 옥수수, 감자, 유채, 헤어리벳치에서 피해가 심하였다. 1차 성충은 성페로몬 트랩에 4월 하순부터 발생되어 5월 중순경에 최고발생밀도를 보였고, 5월 하순 이후로 감소하였다. 또한, 2차 성충은 7월 상·중순, 3차 성충은 8월 상순에 최고발생밀도를 보였으나, 발생량은 1차에 비하여 매우 낮은 수준이었다. 유충발생은 5월 상순부터 발생되기 시작하여 6월 상순에 최대발생밀도를 보였고 그 이후로 점점 감소하는 경향이었다. 따라서 간척지 작물에 발생하는 왕담배나방의 방제적기는 5월 중순이었다. 왕담배나방의 친환경적 관리를 위해 나방류 해충에 살충력이 있는 자체개발균주 HARI042 등 몇 가지 균주를 대상으로 왕담배나방의 살충효과를 조사한 결과, HARI042, HARI005 및 HARI006의 왕담배나방의 3일차 살충률은 각각 91.7, 15.0 및 0%로 HARI042의 살충률이 가장 높았다.

Bacillus thuringiensis (Bt) is a bacterial biopesticide against insect pests, mainly lepidopterans. Spodoptera exigua and Plutella xylostella exhibit significant decreases in Bt susceptibility in late larval instars. To enhance Bt pathogenicity, we used a mixture treatment of Bt and other bacterial metabolites which possessed significant immunosuppressive activities. Mixtures of Bt with culture broths of Xenorhabdus nematophila (Xn) or Photorhabdus temperata ssp. temperata (Ptt) significantly enhanced the Bt pathogenicity against late larval instars. Different ratios of Bt to bacterial culture broth had significant pathogenicities against last instar P. xylostella and S. exigua. Five compounds identified from the bacterial culture broth also enhanced Bt pathogenicity. After determining the optimal ratios, the mixture was applied to cabbage infested by late ins tar P. xylostella or S. exigua in greenhouse conditions. A mixture of Bt and Xn culture broth killed 100% of both insect pests when it was sprayed twice, while Bt alone killed less than 80% or 60% of P. xylostella and S. exigua, respectively. Other Bt mixtures, including Ptt culture broth or bacterial metabolites, also significantly increased pathogenicity in the semi-field assays. These results demonstrated that the Bt mixtures collectively names 'Bt-Plus' can be developed into potent biopesticides to increase the efficacy of Bt.

An entomopathogenic bacterium, Xenorhabdus sp., symbiotic to Steinernema monticolum was investigated in its insecticidal activity. The bacteria induced septicemia of two lepidopteran insects (Plutella xylostella, Spodoptera exigua), a coleopteran insect (Tribolium castaneum), and a hemipteran insect (Riptortus clavatus) when they were injected into hemocoel. The bacterial culture broth contained immunosuppressive factor(s) that inhibited hemocyte nodulation in response to heat-killed bacteria. The immunosuppressive activity appeared to be caused by inhibition of two main immune-associated enzymes, phospholipase A2 (PLA2) and phenoloxidase (PO). HPLC analysis of the bacterial culture broth contained several PLA2 inhibitors. The bacterial culture broth significantly enhanced Bt pathogenicity. There results support a novel insect pest control strategy using eicosanoid-biosynthesis inhibitors.

Field studies were conducted to assess potential effects of transgenic rice expressing Bacillus thuringiensis (Bt) CryIAc1 protein, which is highly effective the rice leafroller, Cnaphalocrocis medinalis, on the rice insect community in 2007 and 2008. Insects were sampled in non-Bt and Bt rice plots with a sweep net and a suction devise. A total of 64,256 individuals in 45 families and 11 orders (30,860 individuals in 43 families and 11 orders in the Bt-rice plots, and 33,396 individuals in 40 families and 11 order in the non-Bt rice plots) were captured and grouped by ecological functional guilds. Species diversity and richness were not significantly different between Bt-rice and non-Bt rice plots. The seasonal pattern of the insect community and the seasonal population fluctuation of insects were very similar between two plots. Collectively, the rice insect community was not influenced by the Bt-rice in the present study.

The first commercial bioinsecticide in Korea was registered in 2003 to control diamond back moth and beet armyworm in Chinese cabbage using Bacillus thuringiensis subsp. aizawai. Currently, fourteen microbial pesticides have registered in Korean market. The Korean government is aiming for 40% reduction (from the 2004 value) in the use of chemical pesticides by 2013. To increase the use of microbial pesticides as an alternative of chemicals, we conducted in vitro bioassay with Bt products. Bt products were treated alone and in combination against larvae of beet armyworm, diamond back moth and tobacco cutworm. Five Bt products shown high mortality against diamond back moth in recommended concentration, but had low control effects against beet armyworm and tobacco cutworm. Mixed Bt products had no synergic effects against the tested three moths. When Bt products were sprayed with higher concentration than recommended dose, those mortality was similar with lower concentration.

Large amounts of genetically modified (GM) grains, including maize, cotton and soybean, have been imported to Korea for food, feed and processing (FFP). To evaluatethe environmental impacts, particularly on non-target insects, of FFP GM grains of unknown source, it is a prerequisite to identify Cry protein types in the test GM grains and to establish proper risk assessment protocols. Imported GM maize grains were randomly obtained and their Cry toxins were analyzed by ELISA using Cry1A, Cry1F, and Cry3A antibodies. Since all tested GM maize grains contained Cry1A, Tenebrio molitor, a non-lepidopteran species, was selected as a non-target insect species. A domestic maize strain was used as a non-GM control, which did not show any differences in major nutritional composition from the GM maize grain. Slightly increased survival rate and head capsule width of T. molitor larvae were observed when reared on GM maize powder, demonstrating no sub-chronic adverse effects of GM maize on T. molitor larvae. Head capsule width of T. molitor neonate increased steadily from hatch to 70-day-old, regardless of being fed Bt or non-Bt maize. ELISA test using Cry1A-antibody revealed that concentration of Cry1A protein slowly increased in the whole body of T. molitor from 0 to 50 post-feeding days when the insects were fed GM maize but rapidly decreased within 5 days when Bt maize-fed larvae were transferred to non-Bt maize, showing that the Cry toxin is not accumulated inside the body of T. molitor once the exposure source is removed. In addition, no Cry protein was detected in the hemolymph of the larvae reared on Bt maize, suggesting little possibility of Cry toxin exposure to higher tropic level. Taken together, the imported GM-maize grains is not likely to cause any side impacts on non-target insect T. molitor.

Bacillus thuringiensis 1-3 (Bt 1-3), belonging to subsp. aizawai (H7), showed different characteristics in plasmid profiles from type strain and had cry2A gene in addition to cry1Aa, cry1Ab, cry1C and cry1D. To clone its plasmids and construct E.coli-Bt shuttle vector, we constructed the plasmid capture system (PCS) by inserting attB sites including lacZ between transposable elements (designated as pPCS-Troy). Through in vitro transposition with total plasmids DNA of Bt 1-3, 53 clones were acquired and their sizes were approximately 10 kb. Based on the sequence analysis, they were classified in four groups showing similarities with four known Bt plasmids, pGI3, pBMB175, pGI1 and pGI2, respectively. One of pGI3-like clones, named as pBt1-3, was fully sequenced and its putative open reading frames (ORFs), Rep-protein, double-strand origin of replication (dso), single-strand origin of replication (sso), have been identified. The structure of pBt1-3 showed high similarity with pGI3 which is one of rolling-circle replication (RCR) group VI family. As a donor for construction of shuttle vector, pDonr-attPEm vector harboring erythromycin resistant gene between attP sites was constructed. Through BP recombination with pPCS-Troy-cloned Bt plasmids and pDonr-attPEm, erythromycin resistant gene was transposed to Bt plasmids. This scheme proposes that in vitro transposition using pPCS-Troy and BP recombination using pDonr-attPEm can easily clone Bt plasmids and construct novel shuttle vectors.

자연형 습지나 인공습지 형태의 자연정화시설은 축산폐수, 농경배수, 생활하수 등이 직접 하천으로 유입되는 것을 방지하는 수질개선효과를 가지고 있다. 습지는 수질개선의 측면뿐 아니라 여러 종류의 생물의 서식처를 제공함으로서 종다양성을 증진시키며, 자연생태계의 생물들을 관찰할 수 있는 생태공간으로 제공되고 있다. 그러나 인공습지 및 자연습지는 모기나 파리와 같은 위생해충의 주요 집단서식처가 되어 문제가 되고 있다. 일반적으로 모기방제는 주로 성충을 대상으로 화학적 방제에 의존하여 왔으나 수질개선을 목적으로 조성된 자연정화시설에서는 친환경적인 방법이 요구되고 있다. 따라서 본 실험에서는 모기유충을 대상으로 곤충병원성미생물인 Bacillus thuringiensis subsp. israelensis을 이용하여 모기유충의 밀도를 감소시키고자 하였다. 먼저 6월말부터 10월말까지 자연형습지와 인공습지의 모기유충밀도변동추이를 조사한 결과, 9월초까지의 습지내 유충의 밀도는 계속적인 증가추세를 보였는데, 인공습지보다 자연형습지에서의 모기유충발생량이 높았다. 트랩을 통해 포획된 성충의 경우에도 자연형습지에서 높게 나타났다. 발생최성기인 7월말부터 8월말까지 습지내에 곤충병원성미생물을 처리하여 밀도 감소의 효과를 확인하였으며, 살충효과가 우수한 Bti를 습지에서 효과적으로 사용하기 위해 모기유충의 행동습성을 고려하여 수화제(WP)와 액상수화제(SC) 두가지 형태로 제형화하여 살포한 결과, 액상수화제형태의 곤충병원성미생물제제가 밀도감소효과가 더 높게 나타났으며, 습지내에 모기유충방제를 위해 처리하기에도 용이하였다.

밀양지역 시설잎들깨 포장에서 발생되는 주요 나방류 해충은 들깨잎말이명나방, 담배거세미나방 및 파밤나방 이었다. 들깨잎말이명나방은 4월 하순부터 11월 중순까지 발생하여 수량에 큰 피해를 주는 해충이다. 이들 나방류 해충을 친환경적으로 방제하기 위해 친환경 농자재로 고시된 Bt제 및 아자디락틴을 이용하여 생물검정 하였다. 처리후 7일차 담배거세미나방 및 파밤나방 유충에 대한 Bt aizawai의 살충효과는 85%였다. Bt의 들깨잎말이명나방 유충에 대한 살충효과는 100%였으나 아자디락틴의 파밤나방 유충에 대한 살충효과는 75.6%였고, 담배거세미나방 및 들깨잎말이명나방에 대한 살충효과는 55%였다. 가을작형 시설잎들깨에서 들깨잎말이명나방에 대한 Bt aizawai 2종(NT0423 WP, GB413 SC)의 방제효과는 처리후 10일차에 95%~96%였으며, 아자디락틴의 방제효과는 83.5%였다. 담배거세미나방 유충에 대한 Bt제 2종 및 아자디락틴의 처리후 10일차 방제효과는 77~80%였다. Bt제와 아자디락틴의 혼용에 의한 들깨잎말이명나방 및 담배거세미나방 유충에 대한 처리효과는 단제 사용구보다 효과가 5%~10% 높았다.

Two entomopathogenic bacteria, Xenorhabdus nematophila and Photorhabdus temperata subsp. temperata, are known to be potent against the diamondback moth, Plutella xylostella, when the bacteria are injected into the hemocoel. This study investigated any pathogenic effect of their culture broth on P. xylostella by oral administration. Only culture broth of both bacterial species did not give enough pathogenic effects by the oral administration. However, when the culture broth was orally treated together with Bacillus thuringiensis (Bt), both cell-free culture broth significantly enhanced Bt pathogenicity against the 3rd instar larvae of P. xylostella. The culture broth was then fractionated into hexane, ethyl acetate, and aqueous extracts. Most synergistic effect on Bt pathogenicity was found in ethyl acetate extracts of both bacterial species. Thin layer chromatography of these extracts clearly showed that ethyl acetate extracts of both bacterial culture broths possessed metabolites that were different to those of hexane and aqueous extracts. These results suggest that the both entomopathogenic bacteria produce and secrete different factors to give significant synergistic effect on Bt pathogenicity.

Real time CCD differential photometry was performed for BT Cnc in Praesepe cluster from February to March, 1994. New 885 differential V magnitudes were obtained for thirteen nights. From the frequency analysis, we have detected two distinct pulsational frequencies of f1=9.7783c/d and f2=7.0153c/d. The first frequency is nearly equal to the previous result(Breger 1980), but the second one is much different. Our reanalysis of the previous data obtained by Guerrero el al.(1979) indicates that the previous result of f3=5.95c/d might be uncertain; it was not detected in the power spectrum. Also it turns out that our second frequency could not be fitted to the previous data and the reanalyzed frequency(f2=7.8813c/d) of the previous data was poor-fitted to our data. Therefore we suggest that the second frequency which might be newly excited in the nonradial mode, has been changed over the last eighteen years.

Bacillus thuringiensis kurstaki와 aizawai의 내독소단백질을 알카리용액 또는 트립신, 곤충소화액 드응ㄹ 처리하여 전기영동한 후 단백질팬턴을 비교하였다. 두 균주의 주요 결정단백질은 130kd와 64kd의 단백질이었으며, 소화액이나 효소로 처리한 경우 공통적으로 62kd의 활성독소가 생성되었다. 그러나, aizawai는 kurstaki에 비해 현저히 적은 양의 62kd 단백질을 생성하였다. 흰불나방의 유충이 Bacillus thuringiensis 독소를 섭식하였을 때 지방체를 비롯한 몇 가지 조직에서 45kd의 스트레스 단백질이 유발되었는데 이 단백질은 열충격이나 저온 충격시에도 마찬가지로 생성되었다.

4개지역 7계통의 배추좀나방(Plutella xylostella)에 대한 비티제의 약제저항성을 엽침법으로 처리하여 조사한 결과 강원도 평창군 횡계면 횡계리의 여름배추 재배포장에서 채집한 개체군이 감수성 개체군에 비하여 41배의 약제저항성이 있었으며 다음은 옥산계통으로 11배의 저항성을 보였다. 한편, pyrethroid계 살충제에 감수성인 JMC계통에서 12배의 저항성이 나타남을 볼 때 필스로이드계와 BT제에 대한 배추좀나방의 저항성 기작은 다른 것으로 추측된다.

Technological convergence is yielding new values and affecting various fields not by single technology but by convergence between technologies. This study aims to analyze the IT -BT-NT convergence and differences between technologies in respect of collaboration within (inventor) and between (assignee) organizations. Among the main technologies leading the technological convergence, IT is the most active of converging with other fields. BT is knowledge-intensive and strong cooperative networks are important in this area. NT is applied in various industrial fields upon the basic technology. Using the data on applied and granted patents by Korean applicants in the U.S., this study conducted quantitative analysis and ANOVA to gain the following results. First, the degree of convergence in between IT-BT-NT is continuously increasing since 2002. Second, BT is where the collaboration within and between organizations is the most active among IT-BT-NT. Third, there were certain differences in the degree of convergence according to the years and the fields of technologies in all the IT-BT-NT. Organizations cooperate with other institutions to sustain their competitiveness with limited internal resources. Companies in these fields are recommended to perform diverse strategies to pursue further collaboration with the outside.