• Journal of Microbiology and Biotechnology
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• 제6권5호
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• pp.326-330
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• 1996

To illustrate whether a hemolysin in $\delta$-endotoxins of Bacillus thuringiensis strain 73E10-2 and subsp. israelensis had immunological identity, a cyt gene of the strain 73E10-2 which encodes a hemolysin was cloned to B. subtilis (transformant 2753). The transformant 2753 containing cyt gene produced the hemolysin which lysed sheep erythrocytes after treatment of proteinase K. The hemolysin was proved also to be toxic against mosquito larvae (Aedes aegypti). The molecular weight of the hemolysin produced from the transformant 2753 was determined to be about 25 kDa by SDS-PAGE and immunoblot. The hemolysin in $\delta$-endotoxin of subsp. israelensis and subsp. kyushensis did not react on immunoblot using polyclonal anti-$\delta$-endotoxin of the strain 73E10-2, but 70-140 kDa mosquitocidal toxins in $\delta$-endotoxin of subsp. kyushuensis reacted.

• 한국미생물·생명공학회지
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• 제19권3호
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• pp.303-307
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• 1991

B.thuringiensis subsp. darmstadiensis 73E10-2의 내독소에 존재하는 hemolysin이 Sephadex G-100 gel filtration과 DEAE-cellulose ion exchange column chromatography에 의해 정제되었으며, 그 순도는 SDS-PAGE와 Ouchterlony test로 확인하였다. 그 결과 정제된 hemolysin의 분자량은 64KDa 의 단백질 이었으며, in vivo 상태에서는 전혀 모기유충에 독작용을 나타내지 않았다는 점이 28KDa 단백질의 차이가 있었다. 또한 정제된 hemolysin과 B.thuringiensis subsp. israelensis의 내독소를 효소항체법으로 검토해 본 결과 양단백질 사이에는 면역학적으로 전혀 상관이 없었다.

• 한국미생물·생명공학회지
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• 제15권6호
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• pp.425-429
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• 1987

B. thuringiensis subsp. israelensis 균주가 생성하는 $\delta$-endotoxin의 alkali 용해에서 생성되는 hemolysin fragment 와 extra-cellular hemolysin 의 상관관계를 조사하기 위한 기초자료로서 extra-cellular hemolysin을 분리 정제하여 그 성질을 조사하였다. 균체 배양액에 유안을 염석 및 투석시킨 후, Sephadex G-200 gel filtration 과 DEAE-cellulose column chromatography를 행하여 균체외 homely-sin을 정제하였다. 정제된 extra-cellular hemolysin 은 SDS-polyacrylamide gel 전기영동에서 47,000 dalton의 분자량을 가진 단일 단백질 band를 얻었다. 또한 정제된 hemolysin은 thiol agents에 의해 그 활성이 증가되었으나, cholesterol 및 protease 처리 또는 금속이온 즉, FeSO$_4$나 CuSO$_4$에 의해 그 활성 이 감소되었다.

• 한국미생물·생명공학회지
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• 제30권3호
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• pp.230-234
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• 2002

모기 살충성 Bacillus thuringiensis subspangiensis 21-2균주의 용혈성 내독소 단백질의 특성을 검토하고자 21-2균주의 용혈성을 가진 유전자를 Escherichia coli HBIO쎄 형질전환시켰다. 이들 중에서 형질전환 균주 47은 독소 단백질을 생산하며 2.5 kb DNA을 함유한다는 것을 효소항체법, immunoblot및 DNA전기영동법으로 확인하였다. 또한, 형질전환 균주 47-5는 2.5 kb DNA를 다시 Hind ll견 절단하여 pUC118 연결시켜서 조제하였다 그 결과형질전환 균주 47-5은 1.Bkb DNA를 함유하며, 23 kD꺼 독소 단백질을 발현하고, 발현된 독소 단백질은 Aedes aegypti모기 유충에 독성을 나타내었다. 또한 23 kDa의 내독소 단백질 그 자체로는 사람의 적혈구를 용해하지 못하였으나, proteinase K로 처리한 후에는 적혈구에 대해 용혈성을 나타내었다.

• 한국미생물·생명공학회지
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• 제21권5호
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• pp.393-398
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• 1993

One strain of mosquitocidal Bacillus thuringiensis, H9B, was isolated from soil. The biochemical characteristics and flagella antigenicity of the strain H9B is similar to that of B. thuringiensis subsp. darmstadiensis. The delta-endotoxin of the strain H9B coincided with that of B. thuringiensis subsp. darmstadiensis strain 73E10-2 on agarose double immunodiffusion test. The delta-endotoxin of B. thuringiensis subsp. israelensis contains hemolysin fragment (28 kb) on SDS-PAGE when the delta-endotoxin was solubilized in alkali, while that of the strain H9B does not contain 28 kb protein.

• Journal of Microbiology and Biotechnology
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• 제31권9호
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• pp.1200-1209
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• 2021

Sepsis is an acute inflammatory response that leads to life-threatening complications if not quickly and adequately treated. Cytolysin, hemolysin, and pneumolysin are toxins produced by gram-positive bacteria and are responsible for resistance to antimicrobial drugs, cause virulence and lead to sepsis. This work assessed the effects of aloe-emodin (AE) and photodynamic therapy (PDT) on sepsis-associated gram-positive bacterial toxins. Standard and antibiotic-resistant Enterococcus faecalis, Staphylococcus aureus, and Streptococcus pneumonia bacterial strains were cultured in the dark with varying AE concentrations and later irradiated with 72 J/cm^-2 light. Colony and biofilm formation was determined. CCK-8, Griess reagent reaction, and ELISA assays were done on bacteria-infected RAW264.7 cells to determine the cell viability, NO, and IL-1β and IL-6 pro-inflammatory cytokines responses, respectively. Hemolysis and western blot assays were done to determine the effect of treatment on hemolysis activity and sepsis-associated toxins expressions. AE-mediated PDT reduced bacterial survival in a dose-dependent manner with 32 ㎍/ml of AE almost eliminating their survival. Cell proliferation, NO, IL-1β, and IL-6 cytokines production were also significantly downregulated. Further, the hemolytic activities and expressions of cytolysin, hemolysin, and pneumolysin were significantly reduced following AE-mediated PDT. In conclusion, combined use of AE and light (435 ± 10 nm) inactivates MRSA, S. aureus (ATCC 29213), S. pneumoniae (ATCC 49619), MDR-S. pneumoniae, E. faecalis (ATCC 29212), and VRE (ATCC 51299) in an AE-dose dependent manner. AE and light are also effective in reducing biofilm formations, suppressing pro-inflammatory cytokines, hemolytic activities, and inhibiting the expressions of toxins that cause sepsis.

• Journal of Microbiology and Biotechnology
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• 제20권2호
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• pp.415-424
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• 2010

The purpose of this study was to investigate the relationship between the global regulatory mechanism known as quorum sensing and expression of virulence factors in Escherichia coli O157:87. A nonpolar luxS deletion was introduced into the chromosome of strain CI03J, a human clinical isolate from South Korea, to create the ${\Delta}luxS$ mutant strain ML03J. Phenotypic characterization of wild-type and mutant strains demonstrated that ML03J had no obvious growth or metabolic defects on 0.2% glucose LB medium, produced a functionally defective flagellum, and could not utilize sorbose; the biological significance of sorbose utilization is unknown. Omics-based analysis revealed the involvement of LuxS in the transcriptional activation of several flagella/chemotaxisrelated genes (flhD; fliA, C, D, S, Z; and cheA, Y, Z), repression of glutamate-dependent acid resistance genes (gadAB), and expression of virulence factors including Shiga toxin, hemolysin, and SepD within the LEE pathogenicity island.