Hydrated EPS

Bacteria are small, unicellular prokaryotic microbes. They have many morphologies, which include rod-shaped, spherical, spirals, helices, stars, cubes, and clubs. Classification of bacteria begins with either aerobic (requiring diatomic oxygen for growth) or anaerobic (not requiring O2 for growth). Bacteria can simply be narrowed down to gram positive (organism that stains purple or blue by Gram stain) or gram negative (organism that stains red or pink by Gram stain). Many physical and nutritional factors influence bacterial growth. Physical factors include temperature (psychrophiles, thermophiles, and mesophiles), pH (neutrophiles, acidophiles, and alkalinophiles), O2 concentration (aerobic

During the purification section of this lab, the LB/amp/ara agar plate was examined for well-isolated green colonies and the LB/amp plate was observed for white colonies with space between each other. These colonies were circled on the outside of the plates using a marker. Next, two 15 milliliter culture tubes containing 2 milliliters of nutrient growth media were obtained and labeled “+” and “-“. Using a new inoculation tube, the circled colonies from each plate were scooped out and immersed in their respective culture tubes. Once the bacteria was mixed into the solution, the tubes were sealed and placed horizontally into the 32⁰ incubator for 24 hours.

The bacterium is capable of producing biofilms that allow microorganisms to stick to solid surfaces forming an attachment, which is enclosed by a slime layer ("Staphylococcus epidermis"). Biofilms protect pathogens from being destroyed by disinfectants inside human bodies ("Staphylococcus epidermis"). In other words, biofilms aid pathogens in causing diseases by releasing microbial products ("Staphylococcus

Pseudomonas aeruginosa is a key opportunistic pathogen characterized by high-level antibiotic resistance and biofilm formation (1).Biofilm is a structured community of bacterial cells enclosed in a self-produced polymeric matrix adherent to an inert or living surface. Biofilmproducing organisms are more antimicrobial resistant than organisms without biofilm. In some extreme cases, the concentrations of antimicrobials required to kill biofilm positive organisms can be three- to four-fold higher than for biofilm negative bacteria, depending on the species and drug combination (2). Biofilms have great importance for public health as they are the main cause of nosocomial infections, especially implant-based and chronic infections (3). Antibiotic resistance in biofilms is due to a combination of many factors that act together to result in a level of resistance that is much higher than that of planktonic bacteria (4,5).

The effectiveness of disease treatment is often presented by the challenge of antimicrobial resistance. Cystic Fibrosis (CF) for example, is a pulmonary infection characterized by the poly-microbial growth of bacteria within biofilms, in the pulmonary tract of humans. For children suffering from CF, Staphylococcus aureus (S. aureus) initially colonizes their airways, which with age, becomes replaced by Pseudomonas Aeruginosa (P. aeruginosa). The eradication of P. aeruginosa by antibiotics fails in 10-40% of CF patients. In the article, it was proven that there existed an interaction between the staphylococcal protein A (SpA) from S. aureus filtrates (SaF, a bacterial supernatant of S. aureus), and an exopolysaccharide (Psl) of P. aeruginosa. This interaction lead to the aggregation and increased resistance to tobramycin¬ – an antibiotic used to eradicate P. aeruginosa, to prevent chronic colonization of the bacteria. The study conducted involved 7 samples of P. aeruginosa that were taken from individuals who underwent successful eradication treatment, and 7 samples from individuals who still had persistent isolates. These P. aeruginosa samples were cultured for 24 hours in media. When SaF was added to the overnight preformed biofilms, the eradicated isolates were not affected by the SaF; however, the persistent isolates showed significant reduction is surface coverage due to densely packed cellular aggregation, without affecting the biomass or viability of persistent isolates. The

Syllabus dot point: Use available evidence to gather and present data from secondary sources and analyse progress in the recent development and use of a named biopolymer. This analysis should name the specific enzyme(s) used or organism used to synthesise the material and an evaluation of the use or potential use of the polymer produced related to its properties

In the United States, the fourth most leading cause of death are hospital-acquired infections. Furthermore, it is estimated that greater than 65 percent of all bacterial infections are associated with biofilms. A greater understanding of biofilms is essential if we are to find effective methods to combat their formation in order to promote public health. Unfortunately, with bacteria in space behaving widely different than on Earth, this can cause a huge problem when it comes to health in space. First of all, biofilms could contaminate and bio-deteriorate the space habitats, the health of the crew, and the function of waste recycling or food production systems in extremely different ways then handled before on Earth. All of these issues would

Both tubes were incubated on ice for 15 minutes. The cells were removed from the ice and immediately “heat shocked” by putting the tubes in a hot water bath of 42 degrees Celsius for 90 seconds. After 90 seconds, the tubes were put back on ice for another minute. 250 microliters of Luria Broth (LB) was added to both tubes by using a transfer pipette. The luria broth acts as a source of nutrients for the E.coli, enabling the E.coli to grow. The solutions were mixed by tapping the tubes with a finger. The cells were incubated at 37 degrees Celsius for 5

The objective of this lab was to observe prepared bacterial cells and to observe and describe the primary features of eukaryotic cells. Also, we investigated the effect of concentration gradient and temperature on the rate of osmosis in an artificial system. Finally, we investigated the effect of solute concentration on the tonicity of cells in plant tissue and Elodea. The purpose of our experiments was to find out whether the effect of concentration gradient on the rate of osmosis had a greater effect than temperature on the rate of osmosis. The purpose of the Elodea experiment was to see if a five percent solution of sodium chloride or distilled water effected the structure of the Elodea.

The bacteria that was contained within Unknown tube #12 is believed to be Pseudomonas aeruginosa, Figure 1. The bacteria tested to be Gram Stain negative, producing a pink, red color retained from the staining process. When the species of bacteria was plated on nutrient media, the cells produced an irregular and spreading configuration as shown in Figure 2. This same plating test provided the margins and elevation, lobate and hilly, respectively. The specimen was stabbed in a Fluid Thioglycollate Medium (FTM) tube using an inoculated loop of the bacteria. The results of this experimentation indicate the type of oxygen requirement of the bacteria. The test found the bacteria to be aerobic as colonies of the bacteria began to form along the top of the FTM tube (Manual 2017).

Whether we like it or not bacteria is everywhere, it can be good and bad, on every surface we touch and even within our bodies. Bacteria, usually as a single celled microorganism, is almost harmless on its own as it can be engulfed by phagocytes and even destroyed by antibiotics. However, bacteria can group together and create something called a biofilm, which can be more detrimental to the health of humans. Biofilms are defined as a complex structure adhering to surfaces that are regularly in contact with water, consisting of colonies of bacteria and usually other microorganisms like yeasts and fungi. (Dictionary, 2002) What they are in not too complex words are microorganisms that stick together to become bigger and stronger cultures. The initial bacteria that attach themselves to surfaces do so by using weak, reversible, short-range electrostatic forces. These forces are called the van der Waals forces. If the bacteria is not disturbed and further grows, at this stage it begins to release a sticky polysaccharide, called extracellular polymeric substance (EPS) that allows the bacteria to strengthen and promote the arrival of pathogens. These

Bacterial biofilms are a major barrier in terms of wound healing. During cell to cell

This contains sugars such as glucose, galactose, mannose, fructose, rhamnose, N-acetylglucosamine and others. The fifth step is that the slime layer of EPS and bacteria entraps particulate materials such as clay, organic materials, dead cells, and precipitated minerals, adding to the diverse biofilm. The final and continuous step is when other organisms attach to the biofilms.

Klebsiella pneumonia ATCC 8724 was cultured aerobically in a 250 mL flask covered by cotton with 100 mL of seed medium at 37 °C. After 8–12 h cultivation, the biomass of seed culture was harvested when cell growth achieved 1.2 to 1.5 OD600 by centrifugation at 4 °C, 8,000 rpm for 25 min. Then, the cell debris was mixed with 50 mL sterilized 2.5% (w/v) sodium alginate solution. The spherical immobilized cells were formed by adding the mixture to 4% CaCl2 (w/v) solution. The granules of immobilized cell were stored at 4 °C over 24 h to improve its solidity. Before inoculing to the main medium of fermentation, the beads of immobilized cell were washed with sterile water at least three times.

Broth cultures of E.coli, Micrococcus luteus and Vibrio natriegens were streaked onto the respective sections. The plate was then incubated at 37oC for 48 hours. The process was then repeated on nutrient agar plates with 5, 6.5 and 10% salt.