from indigenous fermented foods and human gut ... - Thapar University
from indigenous fermented foods and human gut ... - Thapar University
from indigenous fermented foods and human gut ... - Thapar University
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Chapter IV: Results<br />
surfacing pitting was observed (Fig. 4.11 B). Further morphological investigation of all<br />
strains was performed with transmission electron microscopy.<br />
The cells of S. typhimurium had changes in morphology before <strong>and</strong> after treatment<br />
with bacteriocin (Fig. 4.15 A <strong>and</strong> 4.15 B). S. typhimurium had the typical structure of Gram-<br />
negative bacteria, with a uniform wall to which the cytoplasmic membrane tightly adhered.<br />
The outer membrane <strong>and</strong> cell wall circumscription was observed (Fig. 4.15 A <strong>and</strong> B).<br />
Exposure to bacteriocin induced a dramatic change in S. typhimurium <strong>and</strong> S. flexneri 2a cells<br />
(Fig. 4.16 A, B, C <strong>and</strong> D). Following treatment with bacteriocin for 12 h, almost all cells<br />
showed some degree of alteration. In S. typhimurium cells, outer membrane was destroyed<br />
(a), Mesosome-like membranous formations were observed protruding into the cytoplasm (b),<br />
several cells displayed ruptures <strong>and</strong> loss of cytoplasm (c), indicating that the structure of the<br />
cytoplasmic membrane was severely affected by the bacteriocin <strong>from</strong> L. casei LAM-1.<br />
A B<br />
Fig. 4.15(A & B). SEM micrographs of treated <strong>and</strong> untreated S. typhimurium . In<br />
untreated, the cells are long, intact, <strong>and</strong> evenly shaped (A) After bacteriocin treatment,<br />
the cells appear shorter <strong>and</strong> more compact. Morphology of exponentially growing cells<br />
visualized by scanning electron microscopy at 20,000 x magnification
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