Lipopolysaccharides (LPS), also known as lipoglycans,
are large molecules consisting of a lipid and a polysaccharide
joined by a covalent bond; they are found in the outer
membrane of Gram-negative bacteria, act as endotoxins and
elicit strong immune responses in animals.
LPS is the major component of the outer membrane of
Gram-negative bacteria, contributing greatly to the structu
1. Introduction
1) Definition of preservation and food-spoilage micro-organisms
Food preservation is the process of treating and handling food to stop or greatly slow down spoilage (loss of quality, edibility or nutritive value) caused or accelerated by micro-organisms. Some methods, however, use benign bacteria, yeasts or fungi to add specific qualities and to preserve food (e.g., cheese, wine
antimicrobial compounds
Enzymes responsible for synthesis
themselves synthesized
Appear effect at high level of Phytoalexins
Definition
natural antimicrobial compounds
commonly found in fruits and vegetables
Application of Organic Acids
food preservatives
Why? active against a wide range of
classification
-More than 30 staphylococcal species are pathogenic.
-A simple strategy for identification of the more clinically important species is outlined in Fig. 135-2.
-Staphylococci is responsible for both nosocomial and community-based infections
-S. aureus is a part of the normal human flora; 25–50% of healthy persons may be persistently or transiently colonized.
-coagul