When any sugar is metabolized under anaerobic conditions (fermentation), there is increased acid production; thus the butt of the tube remains acid for a longer period of time. When glucose only is fermented, acid is produced throughout the medium but due to the relatively low concentration of glucose in the medium and the aerobic metabolism that is present on the slant, nitrogenous metabolic end products soon change the reaction of the slant to alkaline. These alkaline products neutralize the small amounts of acids present in the slant but are unable to neutralize the large amounts acid present in the butt. Thus, the appearance of an alkaline (red) slant and an acid (yellow) butt after 24 hours incubation indicates that the organism is a glucose fermenter but is unable to ferment lactose and sucrose. Bacteria that ferment lactose or sucrose (or both), in addition to glucose, produce such large amounts of acid that the oxidative deamination of protein that may occur in the slant does not yield enough alkaline products to cause a reversion of pH in that region. Thus, these bacteria produce an acid slant and acid butt. The inclusion of sucrose permits separation of certain Proteus organisms which ferment sucrose from the salmonellae since both of these groups of organisms are lactose-negative and both may produce hydrogen sulfide.
AC
-The medium contains 10 times as much lactose and sucrose as glucose. Bacteria that ferment glucose produce a wide variety of acids, turning the color of the medium from red to yellow. When any sugar is metabolized under anaerobic conditions (fermentation), there is increased acid production; thus the butt of the tube remains acid for a longer period of time. When glucose only is fermented, acid is produced throughout the medium but due to the relatively low concentration of glucose in the medium and the aerobic metabolism that is present on the slant, nitrogenous metabolic end products soon change the reaction of the slant to alkaline. These alkaline products neutralize the small amounts of acids present in the slant but are unable to neutralize the large amounts acid present in the butt. Thus, the appearance of an alkaline (red) slant and an acid (yellow) butt after 24 hours incubation indicates that the organism is a glucose fermenter but is unable to ferment lactose and sucrose. Bacteria that ferment lactose or sucrose (or both), in addition to glucose, produce such large amounts of acid that the oxidative deamination of protein that may occur in the slant does not yield enough alkaline products to cause a reversion of pH in that region. Thus, these bacteria produce an acid slant and acid butt.-
got it from the net too but my professor explained why
There is more lactose and sucrose in TSI agar than glucose because it has to result in enough acid to overcome the alkanization. This is due to the oxidative carboxylation of proteins.
Lactose
Glucose and Galactose.
When lactose is replaced with another type of sugar like glucose in the MacConkey Agar, it is usually to identify bacteria mutations. The method to detect the fermentation in a replacement sugar solution is the same as lactose fermented solution.
sucrose - common table sugar = glucose + fructoselactose - major sugar in milk = glucose + galactosemaltose - product of starch digestion = glucose + glucose
Disaccharide made of two hexo-aldoses: galactose and glucose. IUPAC name: beta-D-galactopyranosyl-(1-4)-D-glucose.
lactose and glucose are not the same! milk contains sugar, and sugar (starch-->glucose) is glucose, so if the milk is lactose free, it still contains glucose and proteins...
No the untreated milk does not contain glucose. When you put in Lactoid in it than the milk will contain glucose.
That's because the lactose is broken down into two other easily digested sugars which are sweeter: breaks into galactose and glucose... this occurs through hydrolysis in the milk prior to drinking it ( because lactase is found in the milk, which contains lactose), thus creating a sweeter milk).
Cola is lactose free it has no lactose it has glucose in it !
lactase breaks down lactose into glucose and glucose monomers.
Lactose is a disaccharide, made up of a bonded glucose and galactose.
When a molecule of lactose is hydrolyzed the monomers that had linked together to form lactose will be pulled away from each other through the addition of lactose. Lactose is made from GLUCOSE AND GALACTOSE, henceforth these two monomers will emerge through the hydrolysis of lactose. Hope this helps...
Lactose
Lactase is the enzyme that breaks down lactose.
Sucrose and Lactose. Sucrose is made from glucose and fructose, and Lactose is made from glucose and galactose. Hope this helps! (:
Yogurt contains lactobacillus, a beneficial bacteria that digests lactose into glucose & galactose.
Glucose and Galactose make up lactose Glucose and fructose make up sucrose Glucose and glucose make maltose