• Journal of Microbiology and Biotechnology
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• 제21권9호
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• pp.885-892
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• 2011

The bacterial communities in the intestinal tracts of earthworm were investigated by culture-dependent and -independent approaches. In total, 72 and 55 pure cultures were isolated from the intestinal tracts of earthworms under aerobic and anaerobic conditions, respectively. Aerobic bacteria were classified as Aeromonas (40%), Bacillus (37%), Photobacterium (10%), Pseudomonas (7%), and Shewanella (6%). Anaerobic bacteria were classified as Aeromonas (52%), Bacillus (27%), Shewanella (12%), Paenibacillus (5%), Clostridium (2%), and Cellulosimicrobium (2%). The dominant microorganisms were Aeromonas and Bacillus species under both aerobic and anaerobic conditions. In all, 39 DNA fragments were identified by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis. Aeromonas sp. was the dominant microorganism in feeds, intestinal tracts, and casts of earthworms. The DGGE band intensity of Aeromonas from feeds, intestinal tracts, and casts of earthworms was 12.8%, 14.7%, and 15.1%, respectively. The other strains identified were Bacillus, Clostridium, Enterobacter, Photobacterium, Pseudomonas, Shewanella, Streptomyces, uncultured Chloroflexi bacterium, and uncultured bacterium. These results suggest that PCR-DGGE analysis was more efficient than the culturedependent approach for the investigation of bacterial diversity and the identification of unculturable microorganisms.

• 한국균학회지
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• 제50권4호
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• pp.373-381
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• 2022

Strain E4, an unrecorded species of dimorphic fungi, was isolated from the gut of earthworms collected in Gyeonggi Province, South Korea. Nucleotide sequence analysis of the D1/D2 region of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region revealed that this species is a member of the genus Blastobotrys, Blastobotrys illinoisensis. Strain E4 differed from its closest known species, B. mokoenaii and B. malaysiensis, by harboring 3-5 and 12-14 nucleotide substitutions in the D1/D2 and ITS regions, respectively. Phylogenetic analysis based on concatenated sequences of the D1/D2 region of the LSU rRNA gene and the ITS region also indicated that strain E4 belongs to the Blastobotrys clade and is distinct from other related species in the clade. The previously unreported isolate could be distinguished from closely related species by its inability to ferment carbon sources. To our knowledge, this is the first report on the isolation of Blastobotrys species from the gut of earthworms in Korea. The strain used was E4 (=KCTC 27831=JCM 33428).

• International Journal of Industrial Entomology and Biomaterials
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• 제48권2호
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• pp.67-77
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• 2024

This study aims to assess the efficacies of exogenous enzymes, derived from invertebrate gut-associated microbes, as feed additives, in reducing volatile organic compound (VOC) emissions using an in vitro pig intestine continuous fermentation system. An in vitro continuous fermentation model was used to simulate a comparable bionic digestion system by co-reacting feed, enzymatic additives (arazyme, mannanase, and xylanase, derived from the gut bacteria of Nephila clavata, Eisenia fetida, and Moechotypa diphysis, respectively), and gastrointestinal microbes, followed by an analysis of their correlations. A significant correlation was observed between exogenous enzyme supplementation and reduced VOC emissions in the fecal phase of continuous fermentation (p < 0.05). The concentration of VOCs decreased by 3.75 and 2.75 ppm in the treatment group following arazyme and multi-enzyme supplementation, respectively, compared to that in the control group (7.83 ppm). In addition, supplementation with arazyme and multiple enzymes significantly affected the microbial composition of each fermentation phase (p < 0.05). In particular, Lactiplantibacillus pentosus and Pediococcus pentosaceus, which changed in abundance according to arazyme or multi-enzyme supplementation, exhibited a positive relationship with VOC emissions. These results suggest that exogenous enzymes derived from invertebrate gut-associated bacteria can be efficiently applied as feed additives, leading to a reduction in VOC emissions.

• 환경생물
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• 제28권4호
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• pp.212-217
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• 2010

각종 유전독성학적 물질로 인한 생물체내의 영향을 평가해보기 위해 E. fetida를 대상으로 본 연구를 수행하였다. 염화수은에 대한 DNA 손상을 알아보는 실험에서는 노출 시간에 상관없이 노출 농도에 비례한 유전자의 손상이 나타났다. 방사선이 지렁이의 DNA 손상에 미치는 영향을 알아본 실험에서도 역시 방사선 총 선량의 증가에 따라 DNA 손상이 증가하는 경향을 보였다. 염화수은에 48시간 동안 노출시키고 방사선을 조사한 지렁이의 세포를 comet assay하면, 수은 단독 처리군이나 방사선 단독 처리군에 비해 DNA의 손상이 유의적으로 크게 나타났다. 염화수은과 방사선 모두에 복합처리 된 지렁이의 DNA 손상치는 각각 단독 처리한 지렁이의 DNA 손상치를 합한 값보다 크게 나타나 두 요인의 상승작용이 확인되었다. 본 연구를 통해 지렁이의 세포내에서 수은과 방사선이 야기하는 DNA 손상을 측정하고, 두 인자의 복합처리에 따른 유전독성 상승효과를 관찰할 수 있었다. 이는 중금속과 방사선의 복합적인 효과를 나타낸 기존의 여러 연구결과와도 비교가 가능한 연구라고 사료되며, 향후 이를 보완하고 더 정확한 평가를 위해 지렁이 세포 내에서의 스트레스 반응 측정이나 효소 활성 실험등을 추가로 수행하여야 할 것이라고 생각된다.

• 환경생물
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• 제27권1호
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• pp.40-47
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• 2009

농생태계 시설 재배지와 과수원에서 서식하고 있는 지렁이상을 확인하였는데 채집된 지렁이는 시설 재배지에서 3과 5속 11종, 과수원에서 채집된 지렁이는 3과 4속 12종으로 다음과 같다 공통적으로 채집된 종은 Aporrectodea tuberculata, Eisenia fetida, Eisenia andrei, Amynthas hupeiensis, Amynthas heteropodus, Amynthas koreanus, Amynthas agrestis, Amynthas hilgendorfi, Amynthas sp., Drawida japonica이다. 시설 재배지에서만 채집된 종은 Bimastos parvus이고, 과수원에서만 채집된 종은 Aporrectodea caliginosa, Amynthas corticis이다. 조사지역내 토양의 물리적 환경에서 유기물 함량은 시설 재배지에서 많은 편차를 보였으나 과수원에서는 비교적 비슷한 경향을 보였다. 경작 단계 별에서 채집된 종수와 개체수는 유기합성농약을 사용하지 않은 무능약과 유기농단계에서 가장 많이 나타났다. 전국적인 농생태계 지렁이 개체군 조사에서 우점군으로 밝혀진 Amynthas agrestis보다 두 지역 모두 Amynthas heteropodus가 가장 많이 출현하였는데 유기합성농약을 사용한 재배지보다 사용하지 않은 재배지에서 많이 출현하였다. 본 연구 결과 Amynthas heteropodus가 작물재배지의 농생태계 생물지표 후보종으로 사용할 수 있음을 확인하였는데. 비교적 이 종은 외부 형태적 형질로 안정되게 나타난다.

• 유기물자원화
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• 제16권4호
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• pp.64-73
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• 2008

glysosyl hydrolase의 하나인 CCF 유사 유전자를 지렁이 Eisenia anderi의 중장으로부터 분리하여 클로닝하였다. 이 유전자의 전체 염기서열 크기는 1,152bp로 나타났으며 개시코돈을 포함하여 384개의 아미노산을 인코딩한다. N-말단 지역의 17개 잔기들은 signal peptide이다. CCF 관련 유전자의 아미노산 서열을 분석한 결과 본 연구에서 분리한 CCF 유사 유전자는 glycosyl hydrolase family 16 (GHF16)에 속하며, 다른 종의 지렁이에서 밝혀진 CCF 및 CCF-유사 단백질과 79~99%의 높은 상동성을 보였다. 여러 지렁이 종에서 분리된 CCF 및 CCF-유사 단백질들은 가수분해활성에 중요한 polysacchride-binding motif와 glucanase motif가 100% 상동성을 나타냈다. 본 연구의 대상종과 유사종인 E. fetida에서 분리된 CCF는 이 종의 서식지가 미생물 활성이 높은 부패 유기질층이기 때문에 다른 종의 CCF에 비해 높은 기질인식 특이성을 갖고 있는 것으로 알려져 있다. 이러한 사실은 본 연구에서 분리한 CCF도 넓은 기질 특이성을 갖고 있을 가능성을 제시해 주고 있으며 이는 산업적 응용 측면에서 유용한 특징 중의 하나라고 생각된다. BLASTX를 이용한 계통수 분석 결과 GHF16 효소는 크게 후생동물군, 녹색식물군, 진정세균군 등의 세 그룹으로 나눌 수 있었으며, 후생동물군의 GHF16은 다시 촉수담륜동물형와 탈피동물형(후생동물형 포함)으로 나뉘어졌다. 본 연구에 의해 E. andrei로부터 분리된 CCF-유사 단백질의 더 많은 생물학적 특성 연구를 통해 ${\beta}$-D-글루칸의 분해 및 생산을 조절하는 산업적 활용이 가능할 것으로 사료된다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제19권5호
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• pp.35-44
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• 2014

In this study, the bio-phytoremediation and phytoremediation technologies were applied to the soils contaminated with total petroleum hydrocarbons (TPH) and heavy metals to evaluate the remediation efficacy from May 2012 to December 2013. Poplar (Populus bonatii Levl.) and Sun Hemp (Crotalaria juncea L.) were selected and planted in phytoremediation practice. These plants were also utilized in the bio-phytoremediation practice, with the addition of earthworm (Eisenia fetida) and petroleum-degrading bacteria (Pseudomonos sp. NKNU01). Furthermore, physiological characteristics, such as photosynthesis rate and maximal photochemical yield, of all testing plants were also measured in order to assess their health conditions and tolerance levels in adverse environment. After 20 months of remedial practice, the results showed that bio-phytoremediation practice had a higher rate of TPH removal efficacy at 30-60 cm depth soil than that of phytoremediation. However, inconsistent results were discovered while analyzing the soil at 100 cm depth. The study also showed that the removal efficiency of heavy metals was lower than that of TPH after remediation treatment. The results from test field tissue sample analysis revealed that more Zinc than Chromium was absorbed and accumulated by the tested plants. Plant height measurements of Poplar and Sun Hemp showed that there were insignificant differences of growth between the plants in remediation plots and those in the control plot. Physiological data of Poplar also suggested it has higher tolerance level toward the contaminated soils. These results indicated that the two testing plants were healthy and suitable for this remediation study.

• Environmental Analysis Health and Toxicology
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• 제20권4호통권51호
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• pp.279-286
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• 2005

Earthworm (Eisenia fetida) acute toxicity test was carried out and ecological risk assessment in soil was performed with national monitoring data. 14 day - $LC_{50}$ of nonylphenol and bisphenol A were 288.1 mg/kg and 90.1 mg/kg, respectively. And NOECs of nonylphenol and bisphenol A were 250 mg/kg and 50 mg/kg, respectively. Significant weight decrement was appeared at 70 mg/kg of bisphenol A, however, nonylphenol at concentrations tested did not severe adverse effect on the weight decrement. The environmental monitoring has been carrying out by NIER since 1999. Exposure levels of nonylphenol in soil were ND$\sim$10.55 $\mu$g/kg and those of bisphenol A were ND$\sim$15.50$\mu$g/kg in National Monitoring data which had been performed from 2000 to 2004. The measured soil exposure level was applied to evaluate the environmental risk assessment. The values of PNEC for bisphenol A and nonylphenol were determined as 0.5 mg/kg and 2.5 mg/kg, respectively using the safety factors which were suggested in EU and OECD. The values of HQ (PEC/PNEC) were determined to be below I for bisphenol A and nonylphenol when the maximum exposure levels for bispheol A (15.50$\mu$g/kg) and nonylphenol (10.55$\mu$g/kg) were applied. Conclusively, the environmental risk assessment of bisphenol A and nonylphenol was not critical in soil.

• Journal of Applied Biological Chemistry
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• 제50권4호
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• pp.281-287
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• 2007

Microorganisms were isolated from earthworm intestine and examined for their ability to degrade 3-methyl-4-nitrophenol (MNP), a main degradation product of the insecticide fenitrothion. An isolate that showed the best degradation of MNP was selected for further study. The 16S rRNA analysis showed that the isolate belongs to the genus of Burkholderia, close to phenanthrene-degrading Burkholderia sp. S4.9, and is named Burkholderia sp. SH-1. When time-course degradation of MNP by SH-1 was examined by high performance liquid chromatographic analysis, almost complete degradation of MNP was observed within 26 h. Colony forming unit value assays indicated that the isolate SH-1 was capable of utilizing MNP as a sole carbon source. SH-1 could also degrade p-nitrophenol (PNP) but could not degrade ortho-substituted nitroaromatics such as 2,4-, 2,6- and 2,5-dinitrophenol. Catechol was detected as the main degration product of MNP and PNP. SH-1 was also found in the soil from which earthworms were obtained. These results suggest that the dispersal of Burkholderia sp. SH-1 into different environment with the aid of earthworms is likely to play a role in bioremediation of the soil contaminated with MNP.

• 한국토양비료학회지
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• 제40권1호
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• pp.51-56
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• 2007

유기성폐기물을 농경지에 투여하기 위하여 작물에 미치는 영향, 토양에 축적되는 중금속 농도 분석이 이루어지고 있으나, 토양에 축적된 총 오염물질이 지렁이에게 얼마나 독성을 갖고 있는지가 구명되어 있지 못한 실정이다. 본 연구는 4종류 유기성 슬러지(생활하수슬러지, 공단하수슬러지, 피혁슬러지, 주정슬러지)와 돈분퇴비를 8년 동안 매년 ha당 12,5톤, 25.0톤, 50.0톤으로 처리한 토양에 대한 지렁이의 독성을 측정하였다. 공단하수슬러지를 처리한 토양를 돈분퇴비와 비교해 보면, 축적된 구리는 18.9~26.2배, 크롬은 7.7~34.7배, 니켈은 14.8~18.8배로 나타났고, 피혁슬러지의 크롬은 35.7~268.0배, 니켈은 14.8~18.8배가 축적되었다. 이렇게 오염된 토양에 지렁이를 8주와 16주 동안 각각 노출시켰다. 8주 노출에서 생활하수슬러지와 주정슬러지의 모든 처리토양과 피혁슬러지 25.0톤 처리 토양은 돈분퇴비와 비슷한 낮은 독성을 나타냈으나, 나머지 공단슬러지와 피혁슬러지의 지렁이 치사율은 26.7~96.7%으로 높게 나타났다. 16주 노출에서 주정슬러지 12.5톤, 25.0톤의 토양만 돈분처리 토양과 비슷한 낮은 지렁이 독성을 보였고, 나머지 처리토양들은 모든 53.3~100%의 지렁이 치사율를 나타냈다. 이러한 결과들은 주정슬러지 50.0톤 처리 토양을 제외한 다른 슬러지 처리 토양은 지렁이에게 독성을 가지는 것으로 나타났다.