Polyhydroxyalkanoates

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.

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

Theoretically, when synthesising butyl ethanoate from butanol and ethanoic acid, the reaction should produce a 100% yield with the reaction running to completion and all of the reactants being converted to products. His however is not the case with this equilibrium reaction. As seen in the calculations, the actual yield of ester obtained from this procedure was 56.83%, a 43.17% difference from the desired product yield. This poor yield is partially the by-product of reaching equilibrium. Once the reaction mixture reaches this dynamic state, the concentrations of both the ethanoic acid and butanol reactants and butyl ethanoate product will remain constant as the rate of the forward reaction equals the rate of the back reaction. This means that only a limited percentage of ester can be obtained.

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

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

Introduction The main purpose for completing the experiment is to understand bacterial growth. In order for bacteria to grow effectively, two important factors are required, physical and nutritional. Physical factors include temperature, pH, osmotic pressure and gaseous requirements1. Bacterial growth is temperature sensitive.

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

Polyhydroxyalkanoate(s) (PHA) are a group of natural biopolymers which are synthesised by a wide variety of microbial genera. They are biodegradable and biocompatible thermoplastics consisting of a repeated chain of various hydroxyalkanoate(s) (HA) monomers. PHA are intracellular carbon/energy storage compounds produced under stress conditions caused by nutrient limitation. Under restricted microbial growth conditions, excessive carbon sources are converted to PHA, which exist as discrete inclusion bodies (granules). The granules are typically 0.2 to 0.9 μm in diameter and are localised in a mobile amorphous state within the cell cytoplasm. As these granules are highly refractive they are clearly visualised under a phase contrast microscope

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.

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

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

Phenoxyethanol or pheno alcohol is a preservative so it is able to increase shelf life. Many aqueous cream do not contain natural preservatives as they do not have a long shelf life from few weeks to months when exposed to oxygen. We used low amounts of phenoxyethanol like t be any bacteria growth and the product remains safe to be used. Phenoxyethanol is able to withstand high heat and able to function well in a wide range of pH. Phenoxyethanol is most effective against gram-negative bacteria, yeasts, mould fungi, so this prevent the bacteria, yeasts and mould fungi growth after finishing the product and dispensing it to patient.

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

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.