Hokkaido University · 지구·행성과학
Koji Yamazaki 교수의 연구실은 주로 산성 음료에서 발생하는 열내성 세균인 알리시클로바실러스 아수스터레스트리스(Alicyclobacillus acidoterrestris)의 생물학적 특성과 검출 기법에 중점을 두고 있습니다. 특히, 이 세균의 열내성, 저항성 메커니즘, 그리고 페디오신 유사 박테리오신인 피시코신 CS526의 분자 기전에 대한 연구를 진행하고 있습니다. 또한, 열역학적 안정성과 단백질 분해효소에 대한 저항성 등 식품 안정성과 관련된 기초 생물학적 메커니즘을 규명하고 있습니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
Thermophilic bacteria isolated from spoiled acidic beverages were identified on the basis of DNA-DNA homology and 16S ribosomal DNA sequence similarity to Alicyclobacillus acidoterrestris. This result suggested that the isolates were a new type of spoilage bacterium in acidic beverages in Japan.
Abstract. The quasi-biennial oscillation (QBO) is quasi-periodic oscillation of the tropical zonal wind in the stratosphere. When the tropical lower stratospheric wind is easterly (westerly), the winter Northern Hemisphere (NH) stratospheric polar vortex tends to be weak (strong). This relation is known as the Holton–Tan relationship. Several mechanisms for this relationship have been proposed, especially linking the tropics with high latitudes through stratospheric pathway. Although QBO impacts
The bacteriocin piscicocin CS526 was inactivated by proteolytic enzymes, was stable at 100 degrees C for 30 min, had a pH range of 2 to 8, and was active against Enterococcus, Listeria, Pediococcus, and Leuconostoc. The N-terminal sequence was YGNGL, not the YGNGV consensus motif common in class IIa bacteriocins (alternate residues underlined). The molecular mass of piscicocin CS526, which had a bactericidal mode of action, was approximately 4,430 Da.
The reverse transcription-polymerase chain reaction (RT-PCR), after a short enrichment culture, was used to detect Alicyclobacillus acidoterrestris in acidic beverages. Two specific primers were selected from the region of V2 and V4 on 16S rRNA gene. With this primer set, 294-bp fragments from A. acidoterrestris could be amplified. The detection limit of the RT-PCR with the FHLP filters was about 10-1 fg of pure total RNA per reaction. Juice samples inoculated with 10(4) cfu of A. acidoterrestri
Molecular mechanism of action of piscicocin CS526 is very similar to that of other pediocin-like bacteriocins, although piscicocin CS526 possesses a unique N-terminal sequence in which Val is substituted for by Leu in the amino acid at position 7.
The influence of divalent cations on the heat resistance of spores of the thermoacidophilic spoilage bacterium Alicyclobacillus acidoterrestris was studied. The heat resistance of A. acidoterrestris spores was not affected by the presence of the different divalent cations (Ca2+, Mg2+, Ba2+, Mn2+ and Sr2+) in the sporulation medium, and by the demineralization or remineralization. And the Ca and Mn contents in A. acidoterrestris spores were scarcely changed by these treatments. However, the heat
