• Asian-Australasian Journal of Animal Sciences
• /
• 제23권9호
• /
• pp.1250-1260
• /
• 2010

Mycotoxins are secondary metabolites produced by fungi. These toxins pose serious health concerns to animals as well as human beings. Biodegradation of these mycotoxins has been considered as one of the best strategies to decontaminate food and feedstuffs. Biodegradation employs the application of microbes or enzymes to contaminated food and feedstuffs. Ruminants are considered to be resistant to the adverse effects of mycotoxins presumably due to the biodegrading ability of rumen microbes compared to mono-gastric animals. Therefore, rumen microbial source or microbial enzyme could be a great asset in biological detoxification of mycotoxins. Isolation and characterization of pure culture of rumen microorganisms or isolation and cloning of genes encoding mycotoxin-degrading potential would prove to have overall beneficial impact in the food and feed industry.

• 한국미생물·생명공학회지
• /
• 제19권6호
• /
• pp.631-636
• /
• 1991

방향족화합물을 생분해하는 미생물을 분리하여 생물학적 처리에 응용하기 위해 폐수 및 토양에서 150종의 균을 분리하였다. 그 중에서 COD 제거율과 방향족화합물의 이용능이 가장 우수한 HC107균을 선발하여 Pseudomonas sp.로 동정하였다. 활성슬러지 장치에서 Pseudomonas sp. HC107 배양액을 2ml/day씩 처리하면서 화학, 제약 및 도료공장의 폐수를 혼합하여 연속처리한 결과 처리수의 COD, BOD 및 phenol 제거율이 평균 92.5%, 95.53 및 93%.5로 나타났다.

• Journal of Microbiology and Biotechnology
• /
• 제13권4호
• /
• pp.636-639
• /
• 2003

Entercbacter agglomerans 6L was isolated from citron (Citrus junos) peel by using an enrichment culture containing (+)-limonene. It was able to metabolize limonene and grew well ($A_{600}$:4.5) on limonene as a sole carbon source. E. agglomernas 6L was highly resistant to limonene toxicity, and grew to 1.0 optical density ($A_{600}$) even at 5% (v/v) of limonene in Luria-Bertani media. ${\gamma}-Valerolactone$ and cryptone were detected as the major metabolic products of limonene by E. agglomerans 6L.

• Pediatric Infection and Vaccine
• /
• 제26권3호
• /
• pp.129-139
• /
• 2019

사람의 호흡기계는 감염 질환을 일으키는 세균과 집락균이 복잡하게 공존하는 기관이다. 세균이 배양되지 않아도 분석이 가능한 16S 리보좀 RNA 유전자 서열분석 기법이 도입된 이래 사람의 미생물군 유전체에 대한 많은 연구 성과들이 보고되었다. 출생 후 영아기 호흡기 내의 미생물총 구조는 이후의 호흡기계 건강과 연관이 있음이 관찰되었다. 본 종설에서는 건강한 어린이의 호흡기 미생물총의 발달, 미생물 간 상호 작용, 숙주의 면역에 미치는 영향, 미생물군 유전체와 호흡기 건강의 연관성에 대하여 지금까지 알려진 내용들을 알아보고자 한다.

• Journal of Microbiology and Biotechnology
• /
• 제9권6호
• /
• pp.861-869
• /
• 1999

An extracellular protease was purified to homogeneity from the culture supernatant of psychrotrophic bacteria Bacillus sp. JH 108 using procedures including ammonium sulfate fractionation, anion exchange chromatography, gel filtration chromatography, and cation exchange chromatography. The enzyme exhibited a molecular weight of 36 kDa, an optimum pH of 8 to 9, and optimum temperature of $60^{\circ}C$. The enzyme preferentially hydrolyzed leucine at the N-terminus of peptides and thus can be classified as an aminopeptidase. It was strongly inhibited by metal chelating agents such as EDTA and l, l0-phenanthroline. The activity lost by EDTA was restored with $Zn^{2+}{\;}or{\;}Co^{2+}$. These divalent cations also stimulated the native enzyme. This suggests that the enzyme is a metalloprotease acting as a leucine aminopeptidase.

• 한국미생물·생명공학회지
• /
• 제41권1호
• /
• pp.79-87
• /
• 2013

An unstable yet efficient phenanthrene-degrading bacterium strain Ph-3 was isolated from a petroleum-contaminated site at the Mathura Oil Refinery, India. The strain was identified as Pseudomonas sp. using a polyphasic approach. An analysis of the intermediates and assays of the degradative enzymes from a crude extract of phenanthrene-grown cells showed a novel and previously unreported pattern of 1, 2-dihydroxy naphthalene and salicylic acid production. While strain Ph-3 lost its phenanthrene- degrading potential during successive transfers on a rich medium, it maintained this trait in oligotrophic soil conditions under the stress of the pollutant and degraded phenanthrene efficiently in soil microcosms. Although the maintenance and in vitro study of unstable phenotypes are difficult and such strains are often missed during isolation, purification, and screening, these bacteria constitute a substantial fraction of the microbial community at contaminated sites and play an important role in pollutant degradation during biostimulation or monitored natural attenuation.

• 한국미생물생명공학회:학술대회논문집
• /
• 한국미생물생명공학회 2000년도 추계 학술대회
• /
• pp.118-124
• /
• 2000

Zn-resistant Methylosobacterium strains were isolated from several non-polluted soil samples collected in all over Japan. Zn-resistant Methylosobacterium strains were predominantly detected in all soil samples and they were also characterized as a UV-tolerant bacteria. The MIC test revealed that the isolates have high zinc resistance in comparison with that of reference Methylosobacterium strains obtained from culture collections. The 16S rDNA-based phylogenetic analysis showed that all strains were divided into two clusters designated as cluster A and cluster B in the present study. All isolates were distributed only in the cluster A. The phylogenetic clustering also well coincided with the differences in the pattern of carbon source utilization.

• Molecules and Cells
• /
• 제27권2호
• /
• pp.211-215
• /
• 2009

Toll-like receptors (TLRs) play a critical role in sensing microbial components and inducing innate immune and inflammatory responses by recognizing invading microbial pathogens. Lipopolysaccharide-induced dimerization of TLR4 is required for the activation of downstream signaling pathways including nuclear factor-kappa B ($NF-{\kappa}B$). Therefore, TLR4 dimerization may be an early regulatory event in activating ligand-induced signaling pathways and induction of subsequent immune responses. Here, we report biochemical evidence that 6-shogaol, the most bioactive component of ginger, inhibits lipopolysaccharide-induced dimerization of TLR4 resulting in the inhibition of $NF-{\kappa}B$ activation and the expression of cyclooxygenase-2. Furthermore, we demonstrate that 6-shogaol can directly inhibit TLR-mediated signaling pathways at the receptor level. These results suggest that 6-shogaol can modulate TLR-mediated inflammatory responses, which may influence the risk of chronic inflammatory diseases.

• 한국수산과학회지
• /
• 제48권4호
• /
• pp.447-453
• /
• 2015

We determined the optimal culture conditions for obtaining the maximum number of intestinal bacteria from the olive flounder Paralichthys olivaceus, and studied bacterial diversity using both culture-dependent and culture-independent methods. Using six culture conditions, mean bacterial numbers were greater than $10^6$ per gram of gut mucus, regardless of the medium. However, the bacterial diversity, based on colony morphology, appeared much higher on Marine agar (MA) and Zobell 2216 agar than on other media. We found eight and 17 cultured bacterial phylotypes with 99% minimum similarity in gut mucus grown on MA and tryptic soy agar, respectively. Furthermore, we used genomic DNA extracted from gut mucus to generate 78 random clones, which were grouped into 25 phylotypes. Of these, six were affiliated with Firmicutes, Actinobacteria, and Verrucomicrobia, and were not found using our culture-dependent methods. Consequently, we believe that Marine agar and Zobell 2216 agar are optimal media for culturing diverse intestinal microbes; we also discovered several novel sequences not previously recognized as part of the gut microbiota of olive flounder.

• Asian-Australasian Journal of Animal Sciences
• /
• 제18권3호
• /
• pp.409-413
• /
• 2005

The objective of this research was to combine the physiological functionality of probiotics (Lactobacillus acidophilus and Bifidobacterium longum) and the milk-clotting activity of culture filtrate from lao-chao to develop a new dairy product which was different from the commercial yogurt. Rhizopus javanicus and Saccharomyces cerevisiae were chosen as a mold and yeast starter for production of culture filtrate. The study results indicated that both probiotic counts increased with incubation time and maintained $10^7$-$10^8$ CFU/ml after 6 h incubation with 10-30% culture filtrates. By contrast, samples with 40% culture filtrates inhibited the growth of L. acidophilus and B. longum. The more culture filtrates were added, the lower titratable acidities and higher pH values in Kou Woan Lao were detected after 36 h fermentation. No significant differences (p>0.05) were found for both L. acidophilus and B. longum, when grown in differing concentrations of skim milk powders. Storage results showed both L. acidophilus and B. longum exhibited excellent stability for 14 days at $4^{\circ}C$ in the Kou Woan Lao.