• Journal of Microbiology and Biotechnology
• /
• 제27권12호
• /
• pp.2211-2220
• /
• 2017

Chlorhexidine gluconate (CHX) and benzalkonium chloride (BZK) formulations are frequently used as antiseptics in healthcare and consumer products. Burkholderia cepacia complex (BCC) contamination of pharmaceutical products could be due to the use of contaminated water in the manufacturing process, over-diluted antiseptic solutions in the product, and the use of outdated products, which in turn reduces the antimicrobial activity of CHX and BZK. To establish a "afe use" period following opening containers of CHX and BZK, we measured the antimicrobial effects of CHX ($2-10{\mu}g/ml$) and BZK ($10-50{\mu}g/ml$) at sublethal concentrations on six strains of Burkholderia cenocepacia using chemical and microbiological assays. CHX (2, 4, and $10{\mu}g/ml$) and BZK (10, 20, and $50{\mu}g/ml$) stored for 42 days at $23^{\circ}C$ showed almost the same concentration and toxicity compared with freshly prepared CHX and BZK on B. cenocepacia strains. When $5{\mu}g/ml$ CHX and $20{\mu}g/ml$ BZK were spiked to six B. cenocepacia strains with different inoculum sizes ($10^0-10^5CFU/ml$), their toxic effects were not changed for 28 days. B. cenocepacia strains in diluted CHX and BZK were detectable at concentrations up to $10^2CFU/ml$ after incubation for 28 days at $23^{\circ}C$. Although abiotic and biotic changes in the toxicity of both antiseptics were not observed, our results indicate that B. cenocepacia strains could remain viable in CHX and BZK for 28 days, which in turn, indicates the importance of control measures to monitor BCC contamination in pharmaceutical products.

• 한국응용곤충학회지
• /
• 제22권2호
• /
• pp.130-137
• /
• 1983

A wide variety of pathogens are known io be seedborne, carried either as infectious mycelium internally or as contaminants on the seed coat. When seed is infected with a pathogen, the seed nay be rendered nonviable or it may remain viable but produce weak seedling. In some cases, the Infected seedling nay not be severely weakened, but nay serve as a source of primary inoculum within a community of plants. A recent problem nay be the dissemination of seedborne pathogens occurring as a result of the massive movements of seed, as a part of the 'Green revolution' Disease of great danger to agriculture may be introduced with seed from other parts of world. Seed treatment with organic mercury compounds in liquid form had become popular since about 1955. Organic mercury compounds contributed considerably to the increase in production of many crops and vegetables. In 1975, however, the use of organic mercury compound was forbidden because of doubts regarding their residual mammalian toxicity in agricultural products. Benomyl-thiram mixture, thiophanate methyl-;hiram mixture and TCMB have now been registered as seed disinfectants for the use of rice blast, brown spot and Bakanae disease. Oxathiinsthiram mixture has been registered as seed disinfectant for barley and wheat loose smut and leaf stripe of barley. Agricultural techniques have made such rapid progress that the nursery methods changed from the use of paddy nursery to box nursery designed for machine-transplanting. The spread of rice transplanting machines has caused increase of seedborne diseases. Among seedborne diseases, Bakanae disease has remarkably increased and causes much damage recently. In order to counter this trend, seed disinfectants must also be diversified. First, effective non-selective disinfectants need to be developed, and second, appropriate control methods always need to be prepared in parallel with the development of new techniques for cultivation.

• 신재생에너지
• /
• 제16권1호
• /
• pp.58-67
• /
• 2020

Microbial electrosynthesis has recently been considered a potentially sustainable biotechnology for converting carbon dioxide (CO₂) into valuable biochemicals. In this study, bioelectrochemical acetate production from CO₂ was studied in an H-type two-chambered reactor system with an anaerobic microbial consortium. Metal-rich mud flat was used as the inoculum and incubated electrochemically for 90 days under a cathode potential of -1.1 V (vs. Ag/AgCl). Four consecutive batch cultivations resulted in a high acetate concentration and productivity of 93 mmol/L and 7.35 mmol/L/day, respectively. The maximal coulombic efficiency (rate of recovered acetate from supplied electrons) was estimated to be 64%. Cyclic voltammetry showed a characteristic reduction peak at -0.2~-0.4 V, implying reductive acetate generation on the cathode electrode. Furthermore, several electroactive acetate-producing microorganisms were identified based on denaturing- gradient-gel-electrophoresis (DGGE) and 16S rRNA sequence analyses. These results suggest that the mud flat can be used effectively as a microbial source for bioelectrochemical CO₂ conversion.

• 식물병연구
• /
• 제10권3호
• /
• pp.198-202
• /
• 2004

2001년∼2002년에 탄저병을 심하게 발병시킨 딸기 재배포장의 식물체 조직에서 탄저병균 Colletotrichum gloeosporioides와 Glomerella cingulata의 월동과 토양에서의 생존유무를 조사하였다 식물체의 엽병, 런너, 관부에서 월동 생존율은 각각 68.7％, 14.3％, 36.7％였다. 그러나 포장조건하에서 분생포자는 토양의 표면, 3, 5, 10cm 깊이에서 전혀 검출되지 않았다. C. gloeosporioides와 G. cingulata의 토양과 이병잔재물에서의 생존력을 비교 조사하기 위해 온도와 수분조건을 달리하여 처리한 다음 경시적으로 분리비율을 조사하였다. 분생포자는 모든 처리에서 10일 이내에 개체군이 40％까지 급격히 감소하였으며 시간이 지날수록 더욱 많이 사멸되었다. 토양 속에서 G. cingulata 분생포자의 생존율은 C. gloeosporioides와 비슷하였다. 분생포자의 생존율은 온도가 낮고 건조한 토양일수록 높았고 토양 온도와 습도가 증가할수록 감소하였다. 토양에 묻어둔 감염된 엽병분석에서도 유사한 경향을 나타내었다.

• Journal of Microbiology and Biotechnology
• /
• 제29권12호
• /
• pp.1957-1968
• /
• 2019

Tetraselmis is a green algal genus, some of whose species are important in aquaculture as well as biotechnology. In algal culture, fluorescent lamps, traditional light source for culturing algae, are now being replaced by a cost-effective light-emitting diodes (LEDs). In this study, we investigated the effect of LED light of different wavelengths (white, red, yellow, and blue) on the growth of Tetraselmis suecica and its associated microbial community structures using the next-generation sequencing (NGS). The fastest growth rate of T. suecica was shown in the red light, whereas the slowest was in yellow. The highest OTUs (3426) were identified on day 0, whereas the lowest ones (308) were found on day 15 under red light. The top 100 OTUs associated with day 0 and day 5 cultures of T. suecica under the red and yellow LED were compared. Only 26 OTUs were commonly identified among four samples. The highest numbers of unique OTUs were identified at day 0, indicating the high degree of initial microbial diversity of the T. suecica inoculum. The red light-unique OTUs occupied 34.98%, whereas the yellow-specific OTUs accounted for only 2.2%. This result suggested a higher degree of interaction in T. suecica culture under the red light, where stronger photosynthesis occurs. Apparently, the microbial community associated with T. suecica related to the oxygen produced by algal photosynthesis. This result may expand our knowledge about the algae-bacteria consortia, which would be useful for various biotechnological applications including wastewater treatment, bioremediation, and sustainable aquaculture.

• 한국응용곤충학회지
• /
• 제19권1호
• /
• pp.39-44
• /
• 1980

배나무 붉은별무늬병은 1973년이래 해마다 발병이 증가하여 1975연에는 발병엽율 $60.3\%$에 달하였으며 1974년 향나무 재식규제조치이후 감소하였다. 붉은별무늬병원균의 동포자발아 시기는 4월중순부터 5월중순까지 였으며 인공강우에 의하여 그 발아시기를 5일 전에 알 수 있었다. 성숙한 동포자퇴의 포자발아에는 3시간 이상의 계속되는 비로서 상당량의 강수가 필요하였다. 배나무의 감염은 강우중이나 강우직후에 이루워지고 있었으며 강양 24시간 이후의 감염은 없었다. 감염후 배나무에서의 잠복기간은 $9\~10$일이었다. 배나무와 향나무사이의 지리가 100m 이내인 경우에는 거의 모든 배나무가 발병하였으나 거리가 멀어짐에 따라 발병율도 감소하였으며 2km 이상에서는 발병이 없었다.

• 한국식물병리학회지
• /
• 제2권1호
• /
• pp.17-21
• /
• 1986

현재 벼오갈병의 발생한계지역인 울진에서 바이러스 보독 끝동매미충의 약충이 포장상태에서 월동할 수 없었다. 매개충의 발생소장과 벼오갈병 발병과의 관계를 보면, 매채충은 년 5회, 발병은 년 3회의 최성기를 나타내었고, 월동세대의 성충, 2세대약충 및 3세대의 약충이 주로 바이러스 전염의 요인이 되었다. 상습발병지의 밀양 30호 재배포장에서 재생병에 $22.4\~26.8\%$의 발병주율을 나타냈으며, 월동에 들어갈 약충이 $11\~30$일간 재생이병주를 흡즙한 결과 이듬해의 바이러스 보독월동충율이 $13.0\~18.2\%$나 되었다. 벼오갈병에 감염된 추파 보리는 월동 생존할 수 없어, 감염식물에서의 월동이 불가능하였다.

• KSBB Journal
• /
• 제4권3호
• /
• pp.246-253
• /
• 1989

Agorobacterium rhizogenes에 의하여 유도된 당근(Daucus carota L. )의 hairy root를 배양하였으며 opine 유무에 대한 형질전환 확인 및 배지조성을 달리하여 성장률에 따른 색소함량을 비교하였고, 재분화된 식물체의 형태적 차이를 관찰하여 몇가지 결론을 얻었다. Hairy root는 균 접종 2-4주 후에 형성층 부위를 중심으로 유도되었다. 유도된 hairy root의 초기 배양에는 R.C.M 배지가 적합하였으며 MSO(2, 4-D $10^{-4} ml/ l, pH6, sucrose 5%, 질소원 0.03M 등)에서 최대 성장을 보여주었고 성장의 증가에 따른 색소의 형성은 비교적 안정하였다. 재분화된 식물체는 정상 식물체에 비하여 형태적으로 차이를 나타내었으며 형질전환된 hairy root 및 재분화된 식물체에서 mannopine 분석으로 Ri-plasmid에 의한 형질전환이 이루어졌음을 확인하였다.

• Journal of Microbiology and Biotechnology
• /
• 제1권2호
• /
• pp.142-149
• /
• 1991

Gardenia callus was induced in MS medium containing $10{\;}{\mu}M$ of 2,4 diphenoxy acetic acid (2,4-D), $1{\;}{\mu}M$ kinetin, and 3% sucrose in the dark. $B_5$ medium was identified to be the most adequate medium for cell growth. Indole-3-acetic acid (IAA) was better growth regulator than 2,4-D not only for cell growth but slso for carotenoid production. Ligt also played a critical role on synthesis of carotenoid. Gardenia cells grown in $B_5$ medium could utilize a polysaccharide, soluble starch, as a carbon source. The cell growth was stimulated in $B_5$ medium fortified with 0.2% yeast extract. The optimum pH for cell growth was 5.7. High density cultures can be maintained by increasing inoculum size and medium concentration accordingly. Specific growth rate and mass doubling time were 0.095 $day^{-1}$ and 7.3 days, respectively. The cell immobilized in alginate tends to formulate more enlarged vacuoles containing yellow pigment compared with those of suspended cell. Carotenoid content of immobilized cell was about $264.4{\;}{\mu}g/g$ fresh weight (F.W.) corresponding twice of the content of suspended cell ($112.08{\;}{\mu}g/g$ F.W.). The color of gardenia cell was shifted from yellow to red when carbohydrase-secreting fungus, Trichoderma reesei, was co-cultivated with gardenia cells.

• 식물병연구
• /
• 제8권2호
• /
• pp.120-123
• /
• 2002

고추 탄저병 발생 상황을 알아보기 위하여 경북 북부 지방의 예천, 안동, 의성, 청송, 영양, 봉화 등 6개 시군 고추 주산지에서 포장 조사한 결과, 본포에서 6월부터 발병이 시작되어 9월 중순에는 약 30%로 급증하였다. 고추 탄저병이 인접과실로 전염하는 데는 보통 2-3일이 소요되었으며, 5-7일 후에 만연되는 것을 확인할 수 있었다. 과실에 탄저병을 일으키는 병원균은 대부분 Colletotrichum gloeosporioides였다. 고추 탄저병 발생에 관여하는 요인은 무엇보다도 이병 잔재물과 연작에 의한 1차 전염원의 증가, 생육기의 강우일수와 그 지속기간 등 기상 요인들이 복합적으로 관여함을 알 수 있었다. 병 발생을 줄이기 위해서는 이병 잔재물의 월동전 처리와 타 작물과의 윤작, 비가림 재배, 예방 위주의 약제 살포가 필요하다고 본다.