Pseudomonas Fluorescens: An Experimental Study

Unlike many environmental bacteria, Pseudomonas aeruginosa has a remarkable capacity to cause disease in susceptible hosts. It has the ability to adapt to and thrive in many ecological niches, from water and soil to plant and animal tissues. The bacterium is capable of utilizing a wide range of organic compounds as food sources, thus giving it an exceptional ability to

In this lab, the organism that we have been working with is the bacterium, Serratia marcescens. S. marcescens is a member of the Enterobacteriaceae family, and tends to grow in damp environments. S. marcescens is an ideal bacterium to work with in the lab because it reproduces quicker than other bacterium. This bacterium produces a special pigment called prodigiosin, which is red in color. The prodigiosin pigment is intensified when S. marcescens is grown at higher densities. During our experiment, temperature, pH, salinity concentration and oxygen requirements were tested on S. marcescens to measure their optimal growth and prodigiosin production.

Unknown lab report# 24 Introduction Microbiology is a study of organisms that surrounds us every day. It requires an educational understanding to identify organisms, and the ability to distinguish different bacteria’s. In applying the learning process of the different bacteria’s, unknown bacteria samples are given to be studied and identified.

Indeed, this study showed the evidence that when Staphylococcus spp grown together with Acinetobacter spp or Micrococcus spp, could influence the growth of Staphylococcus spp. Additionally, Staphylococci influenced the growth of Acinetobacter spp, but mixed response was seen with Micrococcus spp.

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

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).

This experiment is about bacterial growth. We will demonstrate a bacterial growth curve using a closed system. Bacterial growth usually takes up to 12-24 hours to get an accurate result so we will be monitoring this growth between two classes. We also used different methods to determine bacterial growth as well as a few different calculations. One way of receiving data is by using a spectrophotometer where we will record the absorption at a given time to create the bacterial growth curve. We also used the plate count method after performing a serial dilution to calculate the actual cell density at different times given. By using this method we can count the population number of the same given and see the maximum cell density

The research goal was to test whether P. fluorescens phenotypes that could more easily pick up extracellular DNA will be conferred with higher fitness. Prokaryotic evolution has been shaped by transformation, as the environment is a host to a variety of extracellular DNA that is replenished by organisms as quickly as it’s degraded, provided that the trait offers a fitness advantage that allows for conjugation between bacteria (Levy-Booth et al., 2007). If such were the case in the microcosms, there would be a phenotype that was able to intake plasmids at a higher rate and had higher relative fitness values; however, besides for an occasional anomaly in data, there was insignificant intake of DNA across all phenotypes.

Bacterial urinary tract infections represent the most common type of nosocomial infections. Often, the ability of bacteria to both establish and maintain these infections are directly related to biofilm formation on indwelling devices or within the urinary tract itself (30). Enterococci (especially E. faecalis) are one of the main causative agents of urinary tract infection and Catheter-associated urinary tract infections (CAUTIs) besides gram-negative pathogens (31, 32). In these infections Biofilm provides a favorable milieu for microbial survival within the host as the organisms are shielded from the host immune response, as well as antibiotics and antimicrobial agents (33, 34). Several studies conducted to introduce main virulence genes of enterococci that are associated with biofilm formation in these bacteria (11, 13,-17), but virulence mechanism and related genes for biofilm formation are not well understood (35). In this study we investigated biofilm formation of clinical enterococci isolates isolated from Urinary tract infections. These strains were characterized for presence of adhesions and secretory virulence factors. Isolates had diverse presence of virulence from lack to highest amount of virulence genes. Several previous studies investigated relation of virulence genes and biofilm formation, especially presence of esp and gel. Enterococci esp has been implicated as a contributing factor in colonization and persistence of infection within the urinary tract

There was no difference between the control plates which proves that the lid on the plate serves as significant protection, potentially shielding the bacteria to the mutagenic effects the UV light. All three plates were incubated at 25 degree Celsius. The first Control plate showed lots of red and furry growth and the original pattern of swiping was observed in all the quadrants. The second control plate was also observed to have furry and pigmented red growth in all the quadrants, despite being exposed to UV light due to the plate lid during exposure. The experiment plate showed the most interesting results, in the 10 second UV exposure quadrant the bacteria had red pigmented growth but it is speckled, pinpointed and the original swipes were not observed. Moreover the growth seemed not as furry and robust as the control plates. The quadrant exposed to 20 sec of UV light showed significantly less growth than the 10 sec quadrant and the colonies are pinpointed with several beige colonies in between the red speckles. Original swipe pattern of the bacteria was not observed in this colony. In the quadrant exposed to 30 seconds of UV light, the differences are even more significant as the colonies are few and far in between and only several pinpoint red colonies found with a few beige colonies and some colonies with red centers surrounded by beige. The effects of UV light are very drastic in the 40 second quadrant as the growth is severely diminished with only a

Being able to control bacterial growth is something that is important in our everyday lives. As shown in the previous labs, bacteria can grow and create colonies extremely quickly especially in the right environments. By acknowledging this, it is then important to get an understanding of how bacterial growth can be controlled by humans. To control microorganisms it means to inhibit their growth (static) and or kill them (cidal) (Kenneth Todar, 2015); therefore since focusing on bacteria the terms bactericidal and bacteriostatic are both extremely important for this lab. One broad method we will use to control bacterial growth is heat. The amount of heat needed to control bacterial growth is different for different species of bacteria (Kenneth Todar, 2015). Bacteria can also respond differently depending if moist heating method such as an autoclave with steam is used, or a dry heating method such as inoculating a loop over a fire is used (Kenneth Todar, 2015). UV works by damaging the cells DNA, without proper DNA, the cells will die and the object

Biofilms are hard to treat for many reasons. The main reason is because they are highly resistant to antibiotics. This is because the outer cells protect the inner cells from the antibiotic. Therefore, a long-term treatment of antibiotics is required to help the biofilm related infection. Living in groups, give bacteria properties they didn't have when living alone. Another reason they're hard to treat is because they are undefeatable by the body's natural immune defense system. Biofilms avoid chemical disinfection in two different ways. The first is that a gel-like polysaccharide layer provides a physical barrier against any outside agent, biological or chemical. The second is that even if a biocidal agent is introduced in a large enough quantity to eliminate the living bacteria, then

Treatment of the disease is currently based on antimicrobial susceptibility tests according to Clinical and Laboratory Standards Institute (CLSI) [5]. Standard therapy designed for bacteria isolates at planktonic state continues to be applied. However, the pathogenic profile and the antimicrobial resistance are totally different from biofilms, causing reduced cure rates. Furthermore, the ability to form biofilm is important both from the pathogenicity to the animal as for the manufacturing milk industries, where the pathogen can adhere to abiotic food processing structures and persist in adverse conditions through biofilms. The development and establishment of the biofilm depend on the ability of pathogen to adhere to bovine mammary epithelial cells. S. dysgalactiae have many virulence factors including the capacity to bind to the host's cells surface by a protein called GFBA, which is involved in adherence and internalization, by its linking to lactoferrin [6]. It was demonstrated that the S. dysgalactiae isolated from mastitis cows was able to produce biofilm [7]. Economic negative effects in the milk production around the world and the possible involvement of biofilms in S. dysgalactiae mastitis infections, address the research to the study of factors that may contribute for the biofilm production in order to establish more effective treatment strategies. Different studies report that environmental conditions influence the capacity to form biofilm in

In this laboratory experiment, we was introduce to an introduction to streaking and spreading of bacteria in agar plates such that single cells can be isolated from one another, each cell can reproduces to form a visible colony composed of genetically identical clones. Streaking and spreading bacteria is to obtain individual colonies is usually the first step in genetic manipulation of microorganisms.

Microbial growth can be affected by different environmental factors such as temperature, osmotic pressure, oxygen concentration and pH. Six experiments were carried out in this report testing for microbial growth against different environmental factors. Good aseptic techniques were used to prevent contamination, resulting in a uniform set of results that are in line with the literature.