International Journal of Pure & Applied Bioscience (IJPAB)
Year : 2016, Volume : 4, Issue : 4
First page : (134) Last page : (147)
Article doi: http://dx.doi.org/10.18782/2320-7051.2228
Application of New Rapid Fluorescent Staining Method for Direct Enumeration of Live/Dead Bacterial Cells in Different Food Matrix
S. K. Sandhu1*, M. Wadhwa2, M. Arora3 and S. Bhatia3
1Department of Microbiology, College of Basic Sciences and Humanities,
Punjab Agricultural University, Ludhiana 141004, India
2Department of Animal Nutrition, Guru Angad Dev Veterinary and Animal Sciences University,
Ludhiana 141004, India
3Department of Processing and Food Engineering, Punjab Agricultural University, Ludhiana141004, India
*Corresponding Author E-mail: sandhusimran25@gmail.com
Received: 21.07.2016 | Revised: 27.07.2016 | Accepted: 28.07.2016
Abstract
Present work was aimed to study the applicability of the most widely used direct epifluorescent filter technique (DEFT) to enumerate viable and non-viable bacteria using SYTO® 9 and propidium iodide (PI) dyes in complex food matrix. Experimental conditions such as dye concentration, incubation temperature, pH, incubation time and use of different resuspension buffer for optimum application of dual stains were examined with pure cultures. The technique was calibrated by comparing fluorescent emission of bacterial cells with that of known concentration of pure bacterial culture suspension. The results of relative viability of Lactobacillus spp. (MTCC 4185) and Salmonella spp. (MTCC 1163) cells observed under microscope correlated well with the number of live cells in the suspension with R2 of 0.967 and 0.984 respectively. The total counts obtained by DEFT using dual SYTO® 9 and PI stains were far superior than counts obtained by DEFT using acridine orange and DAPI stains. The DEFT count using dual SYTO® 9 and PI dye and SPC count for viable cell enumeration, showed good agreement, accuracy and acceptable interchangeability.
Key words: Lactobacillus, Salmonella, DEFT, live/dead, SYTO® 9, PI.
Full Text : PDF; Journal doi : http://dx.doi.org/10.18782
Cite this article: Sandhu, S.K., Wadhwa, M., Arora, M. and Bhatia, S., Application of New Rapid Fluorescent Staining Method for Direct Enumeration of Live/Dead Bacterial Cells in Different Food Matrix, Int. J. Pure App. Biosci.4(4): 134-147 (2016). doi: http://dx.doi.org/10.18782/2320-7051.2228
