Characterization of Deoxynivalenol Detoxification by Lactobacillus paracasei LHZ-1 Isolated from Yogurt

ABSTRACT Deoxynivalenol (DON) is a potent mycotoxin produced by many Fusarium spp. that invade grains during the growth and storage seasons. Lactic acid bacteria have been reported to be capable of removing several toxins, thereby providing an effective detoxification method for possible contaminated substrates. The present study mainly focused on investigating the detoxification characteristics of DON by a Lactobacillus paracasei LHZ-1 strain, which was recently isolated from yogurt with a strong promise of removing DON from liquid culture. The results obtained showed that the cell wall of L. paracasei LHZ-1 can remove up to 40.7% of 50 μg/mL DON, whereas only 10.5 and 8.9% are removed by the culture supernatant or cellular lysate, respectively. Laser scanning confocal microscopy helped to identify the mechanism of DON detoxification by L. paracasei LHZ-1 through cellular adsorption, where DON was found to bind to the surface of bacterial cells to form complexes. In stability tests, about 39 or 99% of bound DON, either to viable bacterial cells or heat-inactivated cells, respectively, was released by methanol extractions, which indicated that the binding force between viable cells and DON could be stronger than it is in heat-inactivated cells. Adsorption kinetics demonstrated that approximately 33% of DON was removed within 20 h, with a maximum adsorption capacity of approximately 50.5 μg/mL in phosphate-buffered solution.

Download Full-text

Application of Laser Scanning Confocal Microscopy in Roughness Characterization of Worn Surface

Chinese Journal of Lasers ◽

10.3788/cjl20083509.1409 ◽

2008 ◽

Vol 35 (9) ◽

pp. 1409-1414 ◽

Cited By ~ 1

Author(s):

孙大乐 Sun Dale ◽

吴琼 Wu Qiong ◽

刘常升 Liu Changsheng ◽

张恒 Zhang Heng ◽

姚利松 Yao Lisong

Keyword(s):

Confocal Microscopy ◽

Laser Scanning ◽

Laser Scanning Confocal Microscopy ◽

Scanning Confocal Microscopy ◽

Worn Surface

Download Full-text

Characterization of a Macrophage-Specific Infectivity Locus (milA) of Legionella pneumophila

Infection and Immunity ◽

10.1128/iai.68.1.368-376.2000 ◽

2000 ◽

Vol 68 (1) ◽

pp. 368-376 ◽

Cited By ~ 21

Author(s):

Omar S. Harb ◽

Yousef Abu Kwaik

Keyword(s):

Legionella Pneumophila ◽

Cathepsin D ◽

Laser Scanning ◽

Laser Scanning Confocal Microscopy ◽

Alveolar Epithelial Cells ◽

Host Cells ◽

Reading Frame ◽

Alveolar Epithelial ◽

Scanning Confocal Microscopy

ABSTRACT Legionella pneumophila has been shown to possess multiple genetic loci that play roles in its ability to survive within host cells. The mil (macrophage-specific infectivity loci) mutants of L. pneumophila exhibit a spectrum of defects in intracellular survival in and cytopathogenicity to macrophages and alveolar epithelial cells. This study characterizes one of themil mutants (GB111). Intracellular growth of GB111 in macrophages was approximately 100- to 1,000-fold less than that of AA100, the parental strain, at 24 and 48 h postinfection. This defect in turn corresponded to a defect in cytopathogenicity. Sequence analysis of the affected GB111 open reading frame (ORF) revealed it to encode a putative transport protein, and the ORF was designatedmilA. The phenotypic defect of the milA mutant was complemented with a PCR fragment containing only milA, indicating that the defect in GB111 was due to the disruption ofmilA. Intracellular trafficking of the mutant was examined by laser scanning confocal microscopy. The data showed that 50% of the GB111 phagosomes colocalized with the late endosomal/lysosomal marker LAMP-2 (2 and 4 h postinfection), while less than 10% of the AA100 phagosomes colocalized with this marker. On the other hand, over 80% of the GB111 phagosomes were similar to the AA100 phagosome in that they were devoid of LAMP-1 and cathepsin D, and they were colocalized with the endoplasmic reticulum (ER) marker BiP. However, the number of GB111 phagosomes that colocalized with BiP decreased to 50% 6 h postinfection compared to that of AA100, which remained constant (80% colocalization). Thus, compared to AA100, themilA mutation caused a defect in intracellular replication, which was associated with colocalization of the phagosome with LAMP-2 and BiP, while colocalization with LAMP-1 and cathepsin D was not affected.

Download Full-text

Characterization Of Micropipes And Other Defect Structures In 6H-SiC Through Fluorescence Microscopy

MRS Proceedings ◽

10.1557/proc-406-561 ◽

1995 ◽

Vol 406 ◽

Cited By ~ 2

Author(s):

W. D. Vetter ◽

M. Dudley ◽

T.- F. Wong ◽

J. T. Frderich

Keyword(s):

Silicon Carbide ◽

Fluorescence Microscopy ◽

Laser Scanning ◽

Laser Scanning Confocal Microscopy ◽

Defect Structures ◽

X Ray ◽

Scanning Confocal Microscopy ◽

Low Viscosity ◽

Dye Staining

AbstractCrystals of silicon carbide, and other polytypic materials often have micropipes associated with screw dislocations of large Burgers vectors running along their axial dimensions. These defects are considered the most deleterious to the performance of SiC semiconductor devices.Optical micrographs of micropipes in silicon carbide crystals are ordinarily faint. To obtain micrographs showing higher contrast and detail, laser scanning confocal microscopy (LSCM) and simple fluorescence microscopy were used on 6H-SiC single crystals after infiltrating them with a low-viscosity epoxy containing a fluorescent dye. “Staining” the micropipes rendered them much more visible both in fluorescence and conventional optical microscopies. Details of their structures and shapes were revealed, and their dimensions were measured accurately, using LSCM and other, less sophisticated, fluorescence microscopies. Other voids present, such as microcracks, were also visualized. Observations by this optical technique were related to information obtained by synchrotron white beam x-ray topography.

Download Full-text