Vet World   Vol.13   June-2020  Article-16

Evaluation of two fixation techniques for direct observation of biofilm formation of Bacillus subtilis in situ, on Congo red agar, using scanning electron microscopy

Background and Aim: Direct observation, scanning electron microscopy (SEM) is a common method used for the observations of biofilms. N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide) (EDC) fixation method has proven to be a valuable fixation method in the observation of these biofilms. Still, it entails a method of biofilm fixation that can damage slim structures, leading to the impossible observation of biofilm development. In contrast, alcian blue and lysine (ABL) fixation technique appears more glycocalyx of biofilm, fully preserved samples, which may provide much insight into the development of B. subtilis biofilms.

Materials and Methods: Here, the evaluation of the fixation of ABL technique for the study of B. subtilis biofilms was carried out in situ, on Congo red agar. In doing so, the comparison to commonly use conventional EDC technique for sample fixation, and observation was carried out. Observations were based on SEM over 30 samples.

Results: Overall, ABL technique provided excellent observation of biofilms formed in situ, on Congo red agar, and revealed slime structures, which have not been observed, much in standard EDC fixation or earlier in other studies of these biofilms in B. subtilis.

Conclusion: This study reported the appropriate use of ABL in the fixation technique for the preservation of biofilm of B. subtilis. Keywords: alcian blue, Bacillus subtilis, biofilm, Congo red agar, scanning electron microscopy.

Keywords: alcian blue, Bacillus subtilis, biofilm, Congo red agar, scanning electron microscopy.

How to cite this article: Jebril NMT (2019) Evaluation of two fixation techniques for direct observation of biofilm formation of Bacillus subtilis in situ, on Congo red agar, using scanning electron microscopy, Veterinary World, 13(6): 1133-1137.

Received: 15-11-2018  Accepted: 13-02-2019     Published online: 18-06-2020

Corresponding author: Nadia Mahmoud Tawfiq Jebril   E-mail: nadia.tawfiq@uobabylon.edu.iq

DOI: 10.14202/vetworld.2020.1133-1137

Copyright: Jebril NMT, et al. This article is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.