Polyhydroxyalkanoates

The plasmid used is called the pGLO plasmid, which has been genetically engineered. The pGLO plasmid carries the GFP gene. When GFP is produced, the transformed bacterial colonies will glow bright green under UV light. Green fluorescent protein (GFP) is the trait we are primarily looking for in this experiment. For growth, the positive control was the -pGLO LB dish because it had nothing to inhibit its growth, and the negative control was the -pGLO LB/ampicillin dish, because it did not have the genes for Beta-Lactamase to protect it from ampicillin, so it could not grow.

The experimental part of the lab consists of setting up the materials needed. A sample of E.coli and a solution of calcium chloride are first obtained and placed in different test tubes. 630µL of Calcium Chloride (CaCl2) are then removed from the test tube and inserted into the test tube containing E.coli cells (Alberte et al., 2012). The newly formed substance of Calcium Chloride and E.coli is then mixed and incubated in ice for 10 minutes, making the cells more competent. Two test tubes are obtained and labeled; the first test tube is labeled with pUC18 and the second one with “Lux” to represent the plasmids being used. These two test tubes are then incubated in ice. 3µl of the set plasmid are added to each of the two test tubes. The test tubes are tapped to guarantee the cells are well

In this experiment the objective was to transform E. coli with the pGLO plasmid and calculate the transformation efficiency. The hypotheses were that the plate with only LB agar and untransformed E. coli would grow a lawn; the control plate of untransformed bacteria with LB and ampicillin would experience no growth; the transformed plate with just LB and ampicillin would grow colonies of bacteria but it would not glow green under UV light; and the transformed plate with LB, ampicillin and arabinose would grow colonies that would glow green under UV light. The results found supported each of these hypotheses as the bacteria grew as predicted. The

To start the experiment two small plastic tubes were labeled negative pGLO and positive pGLO as the first step in this experiment. A pipet was then used to move 250 microliters of calcium chloride into each tube and the tubes were iced. Bacteria was added using a new sterilized loop each time to the positive and negative pGLO tubes. The loop was twisted around in the tube to ensure that the bacteria was evenly mixed into the solutions and the tubes were iced once again. Another loop was dipped into the tube containing the plasmid and it was removed when there was a visible slight film of residue. The plasmid was dipped into the tube that was labeled positive for the pGLO gene. The two tubes labeled positive pGLO and negative pGLO were iced

As expected the higher growth was seen in the E.coli cells growing outside ampicillin environments, this is because they grow freely with only minor risk, such as contamination. Possible errors in the experiment can have included the difference in the amount of liquid broth added to the E.coli sample that contained no plasmid and that which contained a plasmid. The sample containing no plasmid received half the amount of liquid broth (150µl) as that of the other two samples (300µl). Liquid broth can have incremented the growth in the plates containing plasmid twice as much as on the rest of the plates. Another artifact which can have affected the results was the time each solution spent in both the ice and hot water bath. Uneven sharing may have also taken place within the E.coli used for each plasmid leading to different amounts of colonial growth in the different agar plates used. More accurate results would have been possible if there had been more variation in both E.coli and plasmid

Carson, V. (2013). Microbiology Lab (1st ed.). Department of Cell Biology, Microbiology & Molecular Biology. University of South Florida.

After gaining some knowledge about bacteria, we were giving an investigating bacteria growth lab to do. Our objective was to observe the conditions required for bacteria to grow and to test the effectiveness of substances that may be antibacterial, disinfecting, and or sanitizing. My group and I began our procedure by gathering all the bacteria by swabbing our necks and mouths. After this, we inoculated the culture by rubbing the bacteria on the agar, a nutrient rich gel made from sea kelp, on the bottom side of the container where we grow bacteria, the Petridish. We hoped for the results to come back with little or even no colonies and an immense zone of inhibition around the tiny circle cut out of filter paper covered in toothpaste, Neosporin, and Chlorhexidine Gluconate 4% Solution.

The sterile blank paper disks were coated by the casting of 50 µl of polyacrylic latex modified with 1%T/PANI100:5 additive. Fresh cultures of bacteria were inoculated on nutrient broth and incubated for 24 hour at 37ºC. Definite amount of Muller- Hinton agar was poured into the sterile plate until to be solid. The blank paper disks were impregnated in the inoculated agars. Control disks were prepared using unmodified polyacrylic emulsion. The inoculated plates were incubated at 37ºC under LED lamp light irradiation for 24 h. Antibacterial activity was investigated by measuring the inhibition zones in reference to the test organisms.

Polybutylene pipe has a good dimensional stability polybutylene can operate at temperature up to 100oC without getting soft or distort; polybutylene does not degrade over time. When it comes to reacting with steel components for example radiator. Copper and brass reacts and corrode. The stress retention of polybutylene is better than that of copper, making the pipes stronger when their pressed and it is chemically inert. This does not contaminate the drinking water. The pipe made from polybutylene can be used for mechanical fittings which contains seals and stainless steel locks washers because it has a good dimensional

The goal of this case study was to understand the historical timeline of the production and management of polychlorinated biphenyls (PCBs). A literature review of research studies and governmental legislation was conducted to understand how research has influenced the development of PCB policies and how key issues surrounding PCBs have been addressed. This case study will examine the dangers that PCBs present to the environment and their potential risk to humans and animals. This study will also follow a timeline of the EPA’s actions towards developing regulations in the past, and how the EPA has implemented laws today to tackle the key issues surrounding PCBs. We will explore the events that led up to the EPA’s decision to ban the production

Polycaprolactone (PLC) displays desirable physicochemical, mechanical and thermal and degradation properties relative to other polymers rendering it ideal for dressing woulds over skin creases (Moroder et al., 2010). Specifically, PLC membranes are highly hydrpophobic and thus provide an impressive collection of exudates beneath the wound dressing. PLC membranes essentially create a moist environment on the surface of the wound which enhances its diffusivity. Its hydrophobic capacity also renders it an ideal material for dressing dessicated wounds and those with low-exudate production. This property also enhances the diffusion of growth factors, cell migration, and enzymes required to facilitate wound healing. PLC

The low pH conditions at this bacterial can produce cellulose offer alternatives of the modification of cellulose produced by alteration on culture media, this in-situ modified cellulose materials have a promising industrial applications to paints, coatings, composite materials, or even biomedical devices

Extracellular polymeric substances (EPS) are a heterogeneous matrix of polymers comprised of mainly polysaccharides, proteins, lipids and nucleic acids (McSwain et al., 2005; Mishra and Jha, 2013). EPS are produced in two forms, either associated with the cell surface in capsular form (Sutherland, 1990) or loosely bound to the cell surface as slime polysaccharides (Suresh Kumar et al., 2007). The composition of EPS synthesised varies significantly and thus affecting the physico-chemical properties. Some of the EPS are neutral, but majority are polyanionic (Sutherland, 2001). In addition, the contents of carbohydrates, proteins and nucleic acids was found to have substantial effect on the flocculation of bacteria (Sheng et al., 2005). EPS are synthesized intracellularly either throughout growth, late-exponential or stationary stage (Mishra and Jha, 2013). The rate of production

Since bacteria are haploid, asexually reproducing organisms it is important for these organisms to be able to accept genetic variability into their genome. A process called transformation, which involves absorbing small segments of DNA from deceased organisms in the natural world, does this. Transformation can also be mimicked in the laboratory using plasmid. Plasmids are small segments of DNA that occur in bacteria that allow us to regulate if transformation was successful. We attempted transformation of E. coli cells using plasmid called pVIB, which allows for luminescence and resistance to the antibiotic ampicillin, from Vibrio fischeri, however, we did not achieve a successful transformation.

pGLO is a plasmid that contains several genes, araC, gfp,bla, and an ori of replication. E. coli was artificially induced that became a competent bacteria when it took the pGLO DNA, so it had the ability to have ampicillin resistance and fluoresced when arabinose was present. Two tubes with E. coli were labeled to differentiate which tube the pGLO was added to, then through several steps the bacteria was induced to intake the pGLO DNA. At the end, each tube was inoculated on to three different plates that contained different substances and they were incubated then observed. The results showed only one E. coli culture had growth and fluoresced which was the pGLO+ E. coli that was grown on the plate with LB, amp +arab, there were only two E. coli cultures that did not grow because the pGLO- E. coli did not have the ampicillin resistance to grow in ampicillin conditions, and the rest of the culture plates showed growth. pGLO could be used in food safety experiments done by the food safety department that helped to identify Salmonella and Yersinia enterocolitica in pig slurry, so they were able to calculate how long these bacteria lived in certain conditions before disinfectants were used.