The Effect Of 2 Aminopurine On Mutation Frequencies Of Bacterial Strain

1. EMG 9 and EMG 26 contain strain _lac-_(I- Z+ Y+) and strain _lac -_ (I+ Z- Y-)respectively.Three genes huddled together on the chromosome are required for two strains of _E.coli_ to utilize lactose.Consisting of three genes, namely, _lacZ_, _lacY_ and _lacA_, the _lac_ operon orderly handles these genes to code specific enzymes necessary for the metabolism of lactose. The genes _lacZ_, _lacY_ and _lacI_ would code for beta-galactosidase, galactosidase permease and _lac_ repressor respectively. Regulation of _lac_ operon is also tight and the operon's negative control is made possible by _lac_ repressor (Hill, 1996). With the presence of _lac_ repressor, _lac_ operon will be deactivated and will

The Spot-Overlay Ames Test was used in the lab to find the mutagenesis of Diet Coke and ThermaFlu. Along with these substances three mutant strains of salmonella were also tested. TA 1535, TA 1537, TA 1538 all lacked the ability to grow the amino acid histidine unless reverted back by the potential mutagens. After the first week of testing, results showed that both of the potential mutagens, Diet Coke and ThermaFlu were in fact mutagenic. This was established if colonial growth was at least twice as much as that of the negative control. For the continuation of the experiment, Diet Coke and the TA 1535 strain of S. thyphimurium were chosen to continue experimentation for the second week. Testing commenced once both substances had been mixed

Instead, they argued in favor of the recombination dependent mutation theory. E.coli with a Lac- mutation were found to revert back into Lac+ bacteria when grown in lactose and minimal media. However, the mechanism was still unclear. Some scientists argued the lac region still had some ability to catalyze lactose, and will be amplified until it can grow on lactose. On the other hand, scientist at Indiana University state revertants are created through DNA error. Through three experiments, scientist argued against the amplification dependent mutation theory. Transposons were inserted at various distances from the lac region, and transformation frequency did not decrease as the transposon and lac distance decreased. Amplification of the transposon and the lac region should have occurred at the same frequency because they are close together on the plasmid. Furthermore, tetA gene, another gene on the plasmid, was also selected in the experiment. Similarly, the reversion of this gene was not tied to the reversion of the Lac- no matter the distance. Lastly, the amplification theory states alleles must be cis to undergo amplification. However, scientists found that reversion still occurs when the lac region is trans. Thus, these scientists debunk the amplification dependent mutation theory in favor of the recombination dependent mutation

The researchers were tasked to investigate phenotypic changes in Paramecia. Paramecia are single celled organisms that have appendages attached to their bodies called cilia. The cilia help by allowing a Paramecium to move away from toxins, and towards a food source. The cilia are important because their water environment lacks movement. In the lab, the Paramecia were grown in flask that contained the wheat media, and the bacteria, Klebsilla pneunomiae, was inoculated into the flask. The wheat media was the ideal environment for a Paramecium to grow; Klebsilla pneunomiae was the food source for the organism. The researchers maintained cultures of Paramecium before they introduced the mutagen caffeine. The students believed that if a culture

Materials: 1. D7 yeast strain (ATCC 201137) 2. Ethylmethane sulfonate (EMS, a mutagen for positive control)(prepared) 3. Sterile water (for negative control)(prepared) 4. Medium plates (3 of each of the following): i. Yeast extract peptone dextrose (YPD) agar plate, ii.

In order to achieve this goal they created variants of each gene. These genes were all removed by a similar process by which the pieces of the gene were cut with different restriction enzymes and purified and cloned in order to give us different plasmids. They were amplified using PCR and these were then integrated into the regions and then grown on media and observed. When there was excision of the gene they were looking to remove these strains were cultivated and given designations. Strain WR 441(hDHFR-2) has the hdrA was deleted, WR445 has a deletion of both genes and WR446 (hDHFR-1) has a deletion of hdrB, WR 447 had hts deleted from it. These strains in turn were grown on three different Medias HY which was the rich media, M which was the minimal media and agar plates. In these experiments they found that WR441 needs nothing else and grew on each media with no other enrichment. However WR446 and WR 445 could grow on minimal medium containing both trimethoprim and thymidine, but only when that medium was supplemented with glycine, methionine, pantothenic acid and hypoxanthine. Another strain WR447 was grown and found that it was auxotrophic for thymidine. However when plasmid pHE4 was added to it could grow on minimal medium containing trimethoprim and thymidine. When the hts was removed the hdrB gene did not have a strong promotor which appeared when the hDHFR-2 didn’t express itself enough to give the organism the trimethoprim resistance it need to get a high copy number. Because of this we can use the hdr gene as an expression point for Hf.volcanii. At the lowest level of expression, only complementation of purine, glycine, pantothenate and methionine autotrophy will occur When the gene has a higher level of expression we can see that there will be prototrophic growth in minimal medium, and when the gene is working at its highest level it will give a resistance to

The purpose of this lab is to examine the specificity of the lactase enzyme to a specific substrate and how it can denature due to the rise in temperature.

The objective of this experiment was to introduce the study of bacterial genetics in order to identify the potency of different mutagenic agents. Our primary aim was to demonstrate the different techniques needed to isolate biosynthetic auxotrophic mutants using chemical, physical and transposon mutagenesis. The second aim was to plan and execute an experiment designed to isolate catabolic mutants (Lac-) as well as conditional mutants (Temperature sensitive) using only a chemical treatment (EMS). Also, to make and characterize transposon-insertion mutants of KL14 using bacteriophage as a transposon delivery

The electrophoregram showed only arrow single one band, and in-gel (zymogram) enzyme activity also confirmed its purity of tannase enzyme (Fig. 1). The molecular mass of tannase from E. cloacae was found to be ˜45 kDa (Fig. 1). Results of SDS-PAGE indicate that the tannase from E. cloacae is monomeric in its structure. Noteworthy, the MALDI-TOF-MS analysis (Fig. 1) of purified tannase also indicated the presence of a single strong peak at m/z 52,000, thus definitelyruling out any possibility of multimeric protein being responsible for tannase activity. Previously, Klebsiella pneumonia and Lactobacillus plantarum tannase were also found to be monomer with molecular mass of 50 and 46.5 kDa, respectively (Sivashanmugam & Jayarama 2011; Iwamoto et al., 2008). To characterize the tannase further, isoelectric point of the enzyme was measured and it was found to be approximately 4.4 (Fig.

In this paper when analysed the metabolic footprinting of S. lividans TK24 wt (white), wt with a plasmid (light grey), and wt with a recombinant protein (light black) grown in a NMMP with a 5g/L of casamino acids Streptomyces lividans, and observe the uptake rate of the different aminoacids it was observed that glutamate is used as a preferential source of C and N at exponential phase. Only when it is exhausted bacteria used the carbon source that exists in the medium (mannitol or glucose ). We used the same medium to perform our experiments and the downregulation of genes related with the glutamate uptake in the agarase overproducer strains is related with the stringent response situation while in the alpha-amylase overproducer strain these were upregulated.

Awan et al., (2011) reported that Aspergillus niger is a potent producer of many industrially important enzymes and may genetically be improved by exposure to gamma rays. The mutants recovered after treatment by gamma rays were found to be effective producers of enzymes (Awan et al., 2011). Mutagenesis of Aspergillus niger by using chemicals has been reported earlier to improve many industrially important enzymes and other products. The cells of Aspergillus niger were subjected to mutagenesis by ultraviolet irradiation, resulting in 45.4% activity of cellulase (Junwei and Shuyun, 1988). Non

2. Introduction: Each student was given unknown bacteria and was instructed to perform a variety of experimental tests that would help to identify their bacteria. During the process of identification, the unknown bacteria was added to many different testing medias using aseptic technique. They are as follows: lactose fermentation on eosin methylene blue (EMB), TSI (Triple Sugar Iron agar), Phenol red sucrose, the SIM test, H2S by SIM, IMViC (indole, motility, voges-proskauer, and citrate), Urease (urea broth), PDase (Phenylalanine Deaminase), Lysine Decarboxylase, and Ornithine Decarboxylase. Colonial morphology on EMB was used to

The host bacterial strain L. Lactis 7–18, was grown at 30 °C in M17 broth (Oxoid Ltd., Basingstoke, Hampshire, England) supplemented with 0.5% glucose (GM17) (Terzaghi and Sandine, 1975). The thermo-resistant lactococcal virulent phage P1532 used in this study was obtained from the Félix d 'Hérelle Reference Center for Bacterial Viruses (www.phage.ulaval.ca). P1532 phage was amplified on L. lactis 7-18 that was initially grown in GM17 until an optical density at 600 nm of 0.1. Then, 10 mM of CaCl2 was added as well as an approximately 105 PFU/ml of phage P1532. ……….When the culture was completely clear, the phage lysate was filtered using a 0.45-μm syringe filter and then stored at 4 °C until further use.

This experiment was performed to test the hypothesis if LB nutrient broth, +pGLO and -pGLO Ampicillin, and Arabinose was placed in the E. coli plates, then there will be a significant growth in the newly transformed bacteria and it will possess the ability to glow under UV light. The measurements were recorded from the bent glass tube in each glass test tube. The transformation protocol tested for the newly possessed traits in E.coli bacteria. Throughout the experiment there were many probable reasons for failure. If the pipettes and sterile loop were not thrown out in between each use, a cross contamination could cause a miscalculation in the experiment causing the data results to fail. The hypothesis that was tested was validated due to the positive results with each experiment stating that newly transformed organisms due in fact pass on traits.

Illnesses caused by disease and other infections have troubled inhabitants of this world for centuries. However, modern science and epidemiology allow us to break down the organisms that cause the illness in order to treat and prevent it. We can now understand the classification and type of organism as well as its life cycle. We can discover its mode of transmission and methods to diagnose it. By determining these factors, the future of the organism can be determined and lives can be saved. Today, many new diseases are being examined in hopes of containing ailments and treating those who have contracted them. One such ailment is an organism called New Delhi Metallo-beta-lactamase, more