Cellulose normally referred as the most abundant macromolecule on earth that produced by plant. This cellulose is a type of carbohydrate which often found in plant. The cellulose synthesis can also occurs in other groups rather than plants, such as groups of algae, a number of bacterial species including cyanobacteria and also tunicates in the animal kingdom (Saxena et al., 2005). Cellulose generally consists of glucose glycosidically linked in β-1-4 conformation as shown in Figure 2.1. The repeating unit of the polymer synthesis consists of two glucose molecules bonded together. Similarly, the molecular formula of bacterial cellulose (C6H10O5)n is the same as the plant cellulose, but differ by their physical and chemical features. Bacterial cellulose is more preferred rather than plant cellulose since it can be obtained in higher purity and exhibits a higher degree polymerization and crystalinity index. In addition, the bacterial cellulose contains higher tensile strength and water holding capacity compared to plant cellulose …show more content…
Acetobacter aceti has four subspecies which are aceti, orleanensis, xylinum and liquafaciens. Acetic acid bacteria are bacteria that derive their energy from the oxidation of ethanol to acetic acid during fermentation. These types of bacteria are found naturally, where ethanol is being formed as a result of yeast fermentation of sugars and plant carbohydrates. Acetic acid bacteria have important roles in food and beverage production, as well as in the bio production of industrial chemicals. Jonas and Farah (1997) stated that the gram negative bacterium Acetobacter xylinum is the most studied for its capacity to synthesis cellulose among other bacteria that can synthesis bacterial cellulose. Keshk (1999) reported that different substrates used can produce different yield of bacterial
Differential media allows for the differentiation between two similar micro-organisms through how the bacteria may handle certain compounds found in the media or the different reactions that may take place when the bacteria is exposed to the medium (3). Selective media on the other hand allow only certain microbes to grow. This is due to the plate containing a limited amount of nutrients, compounds and chemicals that will deter the growth of certain bacteria (3). Dyes, antimicrobial substances, salts, certain growth inhibitors and, antibiotics are also found on this type of medium (3). The differential and selective media mentioned in this lab are as follows:
I expect to learn the biochemical differences in bacteria from this lab. Also, how to identify different species of bacteria. Material & Methods For the first day of the practical, an unknown specimen was provided
Figure 3. Testing of transformed and mutant bacteria on minimal medium Growth was observed on the Transformed (Trsf) section and not on the Mutant (Mut)
Transformation was successful in the plates where the bacteria consumed the pGLO plasmid. In the first plate that the bacterium was plated on it included the LB broth and of ampicillin antibiotic (amp), 2 colonies were present. The second plate of bacteria was grown with the presence of LB broth, ampicillin, arabinose sugar (ara), and 22 colonies were observed. But a green fluorescent glow of the colonies was only present in plate 2. Plates 3 and 4 were the control plates.
The tube was placed back in incubation for 96 more hours to observe any more positives. 2.10 Catalase Test A trypticase soy agar plate was used and after incubation, four drops of 3% Hydrogen Peroxide was added to the plate to flow over the bacterial growth. A presence of bubbling was observed. 2.11 Starch Hydrolysis
In the laboratory, identification of an unknown bacterium is often necessary. In the lab, a random sample consisting of three different bacteria was selected. The sample contained one gram-positive, one gram-negative paracolon, and one gram-negative coliform. The purpose of the experiment is to identify each of the three species that the mixture contained. After receiving an unknown mixture, the sample was streaked for isolation onto TSA, blood agar, and MacConkey plates.
In the spot overlay Ames assay in (Table 1) the positive control is mutagenic. The positive control for TA1535 shows that are double the amount of colonies than the negative control but it was expected that the colony count to be higher. The TA1538 does not show it is mutagenic because a possible source error can be the bacteria labels were switched.
The unknown bacteria was then tested on multiple selective and differential media. Growth was present on the MacConkey Agar and the colonies were the same color as the plate, which told me my bacteria was gram negative and did not ferment lactose. There was no growth on the Mannitol Salt Agar, and this told me the unknown was not salt tolerant and did not
Starch amylase testing was equally unsubstantial since the only amylase producing bacteria was ruled out after Gram staining. Unknown #10’s negative citrate test result was also unhelpful because E. coli is citrate negative and P. vulgaris is a variable citrate producer that can also be citrate negative. H2S production in the Kligler’s Iron Agar test ultimately proved that Unknown #10 was Proteus vulgaris. P. vulgaris is the only assigned bacteria that produces H2S, so when a black precipitate obscured the yellow butt of the Kligler’s Iron Agar slant, E. coli was ruled out. Not only did the H2S product confirmed that Unknown #10 was P. vulgaris, it confirmed P. vulgaris’ motility.
Although toluene does not look anything like a cellulose, it is still possible to perform nitration on the benzene ring through electrophilic aromatic substitution. Using the same reagents used by Schönbein (nitric acid and sulfuric acid) you can install 3 NO2 groups on the ring and form TNT, a common
For example, fermentation occurs in yeast in order to gain energy by transforming sugar into alcohol. Fermentation is also used by bacteria, they convert carbohydrates into lactic acid. Ethanol fermentation is done by yeast and certain bacteria, when pyruvate is separated into ethanol and carbon dioxide. Ethanol fermentation has a net chemical equation: C6H12O6 (glucose) > 2C2H5OH (ethanol) + 2CO2 (carbon dioxide). This process of ethanol fermentation is used in the making of wine, bread, and beer.
The Another medium used was MAC, it is used to isolate and differentiate gram-negative organisms and it is a pink, dusty rose color. Lastly, the Citrate Slant is a green color and it was used as a differential test to examine enzymes. The media were inoculated at 37°C for 48 hours, then it was observed to determine the
It can be said that natural fibres has less of an effect on the earth and the economy than synthetic fibres, however there are pros and cons to everything. We look at natural fibres as being more natural and safer, we see it as making less of an effect on the earth and the economy and we see it as reducing our carbon foot print, however we often miss steps. We don’t look at what has to be done in order to get that product from the raw materials to the final product. There are pros and cons to both synthetic fibres and natural fibres.
Joshua Miller 12/18/17 Fermentation Lab report Introduction The term fermentation refers to the chemical breakdown of a substance by bacteria, yeasts, or other microorganisms, typically involving effervescence and the giving off of heat (wikipedia). Sugars are converted to ethyl alcohol when fermentation happens. In this experiment we determined if yeast cells undergo fermentation when placed in a closed flask with no oxygen. Glucose and yeast are mixed together in a closed flask and allowed to incubate for about one hour.
CONCEPT OF SHELF-LIFE EXTENSION: Chitosan is a polymer which is extracted from chitin. It is natural, and thusly biodegradable and biocompatible. As a novel food preservative, chitosan offers the possibility to form edible film coatings on fresh or processed perishable foods in order to extend their shelf life. The chitosan film has antimicrobiological properties which allow it to protect the food it is coating.