Design an experiment for measuring the activity of sulfuroxidizing bacteria in soil. If only certain species of the sulfur oxidizers present were
To discuss:
Design an experiment to measure the activity of sulfur-oxidizing bacteria in the soil. How to detect, if only certain sulfur oxidizing species present were metabolically active. How to prove the activity measurement was because of biological activity.
Introduction:
Sulfur oxidizing bacteria (for example, Thiobacillus, Thermothrix,Sulfolobus, and Thiothrix) can convert hydrogen sulfide (H2S) into sulfate (SO42) or other forms of sulfur. They can grow in various environments, for example, soil and water. MAR-FISH is a fluorescence in situ hybridization (FISH) combined with microautoradiography (MAR). MAR-FISH can simultaneously identify microorganisms and their metabolic property.
Explanation of Solution
An experiment to measure sulfur-oxidizing bacteria from soil:
- Isolate Thiobacillus species (gram-negative bacteria) from sulfide rich soil (for example, paddy field) followed by serial dilution in water.
- Add 5 ml water containing sample (bacteria) to 50 ml thiosulfate mineral salts medium (thiosulfate MSM).
- Incubate the medium at 30°C for 7 days. The formation of turbidity and reduced pH of the thiosulfate MSM medium indicates the bacterial growth.
- Further streak plate method (onto the solid medium of thiosulfate MSM) can be used to isolate the pure culture of Thiobacilli.
- Incubate the petri plate at 30°C for 7 days.
- Screen the purified culture of Thiobacilli in the MSM consisting of Na2S but not of Na2S2O3.
- The sulfide medium used for the growth of bacteria is the sole source of energy.
- Further, Thiobacillus can be confirmed by gram-staining.
- Sulfur-oxidizing bacteria, such as Thiobacillus species can be used to study.
To measure the activity of sulfur oxidizing bacteria in the soil, the radioisotope H235S should be used. The soil should be incubated with radioisotope (H235S) to know whether the sulfide oxidation occurred or not. After incubation, the presence of 35SO42- should be analyzed to prove the activity of sulfur-oxidizing bacteria in the soil. The presence of 35SO42- proves that the sulfide oxidation has occurred in the test. To prove that the oxidation occurred due to biological activity, sterile the soil (medium) before the addition of labeled H2S. This is used as a control in this experiment. If the oxidation activity observed in the experiment is biological, it should be absent in the control. The MAR-FISH can be used to identify the presence of metabolically active bacteria in the soil.
MAR-FISH (microautoradiography- fluorescence in situ hybridization) technique is used to evaluate the microbial identification (phylogeny) with measurement of metabolic activities. MAR-FISH is used to assess the metabolism of a specific radiolabeled substance by microorganisms in the natural sample and also help to identify those particular microorganisms. Therefore, MAR-FISH can be used to identify the metabolism of radioisotope H235S by microorganisms in this experiment.
Want to see more full solutions like this?
Chapter 19 Solutions
Brock Biology of Microorganisms (15th Edition)
- During cheese production, LAB convert lactose to lactate and casein (milk protein) to amino acids. Lactate and amino acids then become the substrates for further microbial growth, which results in aroma production and deacidification of the cheese. The yeast Yarrowia lipolytica grows on the surface of many cheeses; it is capable of both lactate and amino acid catabolism. When grown on a lactate plus amino acid medium, Y. lipolytica preferentially consumes amino acids. Amino acid degradation results in the release of ammonia, which increases the pH. Draw a flow chart that shows the LAB fermentation of milk, followed by the growth of Y. lipolytica. Indicate which substrates are consumed first and what happens to the pH. Based on this simplified scenario, why do you think most cheeses involve the activity of more than one yeast species?arrow_forwardPlease answer the following correctly: i) Salt is often used as a food preservative to prevent bacterial and fungal growth (for example, in country ham). But salt is also important to enhance the flavor of bread when added in small amounts. At what concentration does salt begin to inhibit yeast fermentation? j) Does the food preservative Na benzoate inhibit cellular respiration? k) How do fermentation rates compare for baker's yeast (saccharomyces cerviside) and sourdough yeast, (candida milleri) in different pH environments? l) How do fermentation rates compare for yeast used in brewing most beers (S. cervisiae) and lager (S. pastorianus - a hybrid between S. cervisiae and S.eubaymus)?arrow_forwardBeer is produced by yeast fermentation of grain to ethanol. Why must the process of beer production be anaerobic?arrow_forward
- An organism is discovered living near hydrothermal vents deep in the ocean where sunlight cannot reach. It is found to gain energy through the oxidation of inorganic sulfur compounds present in its environment and uses this energy to turn CO2 into complex organic compounds. Based on this information, how would this organism be best categorized metabolically? Chemoautotroph Chemoheterotroph Photoautotroph Photoheterotropharrow_forwardUse the multiple choice questions to identify what components of the redox loop would have to be in each numbered box for this organism to be able to produce ATP using this system. Do not worry about stoichiometry. a) What should be in box 1? MQ MQH2 Electron H+ b) What should be in box 2? MQ MQH2 Electron H+ c) What should be in box 3? MQ MQH2 Electron H+ d) What should be in box 4? MQ MQH2 Electron H+ e) What should be in box 5? MQ MQH2 Electron H+ f) What should be in box 6? MQ MQH2 Electron H+ g) What should be in box 7? MQ MQH2 Electron H+ h) What should be in box 8? MQ MQH2 Electron H+ i) Which boxes in the diagram directly result in increasing the pH gradient? (select all that apply) 1 2 3 4 5 6 7 8arrow_forwardUse the graph below to determine which of the following is the optimal temperature for catalase. Catalase Activity 1.5 1.4 1.3 1.2 1.1 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 10 20 30 40 50 60 Temperature (°C) O 0.8 O 1.45 O 37 O 20 Percent Increase in Oxygen per Minutearrow_forward
- You have been assigned to lead a lab that takes plant material and converts it into ethanol for fuel. The process relies entirely on enzymes that break down the cellulose into ethanol. How would each of the following factors affect the efficiency of your task: temperature, pH, enzyme concentration, substrate concentration, allosteric inhibitor, competitive inhibitor, allosteric activator? For each factor, explain what would happen if you increase it and what would happen if you decrease it.arrow_forwardL-lysine is being produced by Corynebacterium glutamicum in a bioreactor using glucose as the carbon source, ammonia as the nitrogen source. The bacteria grow aerobically in a continuous process at steady-state. All streams of this process are aqueous. In the inlet stream, 8 grams of glucose is included per 100 grams of stream liquid, which flows at a rate of 500 kg/h. The flow rate of glucose in the outlet steam is 1 kg/h. The reaction occurs at 25 °C. (a) What is the mole percentage of glucose that was consumed during cell growth inside the bioreactor? (b) Does the growth of Corynebacterium glutamicum cells inside this bioreactor release or absorb heat? Should heat be supplied to the bioreactor, or removed from, to maintain the operation temperature?arrow_forwardL-lysine is being produced by Corynebacterium glutamicum in a bioreactor using glucose as the carbon source, ammonia as the nitrogen source. The bacteria grow aerobically in a continuous process at steady-state. All streams of this process are aqueous. In the inlet stream, 8 grams of glucose is included per 100 grams of stream liquid, which flows at a rate of 500 kg/h. The flow rate of glucose in the outlet steam is 1 kg/h. The reaction occurs at 25 °C.What is the mole percentage of glucose that was consumed during cell growth inside the bioreactor?Does the growth of Corynebacterium glutamicum cells inside this bioreactor release or absorbheat? Should heat be supplied to the bioreactor, or removed from, to maintain the operation temperature?arrow_forward
- List the three chemical processes that can lead to the removal of ions from solution and thus drive a metathesis reaction. Give one example for each of the three chemical processes.arrow_forwardA fermentation process was carried out with a yeast in a chemically defined medium containing glucose (C6H12O6) as a carbon source aiming at the production of ethanol (C2H6O). For the evaluation of the process, samples were taken at different times of cultivation and the experimental results are shown in the Table below. Based on the experimental results, one can: a) Calculate the overall substrate-to-cell conversion factorb) Calculate the overall substrate to product conversion factorc) Calculate the volumetric productivity of ethanold) Determine the theoretical maximum conversion of glucose to ethanole) Determine the efficiency of the processf) Based on the MONOD equation, calculate the maximum specific growth rate and the value of the saturation constantg) Determine the culture generation timearrow_forwardLactic acid production is carried out in the stirred tank bioreactor. 100 mol glucose entered the production tank initially. E.coli are used during production. According to this, a-) Calculate how much lactic acid is produced in this production.b-) draw the bioreactor and its flowchart. (raw material = molasses, the organism used for production = Thermophilic bacteria)arrow_forward
- Human Anatomy & Physiology (11th Edition)BiologyISBN:9780134580999Author:Elaine N. Marieb, Katja N. HoehnPublisher:PEARSONBiology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStaxAnatomy & PhysiologyBiologyISBN:9781259398629Author:McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa StouterPublisher:Mcgraw Hill Education,
- Molecular Biology of the Cell (Sixth Edition)BiologyISBN:9780815344322Author:Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter WalterPublisher:W. W. Norton & CompanyLaboratory Manual For Human Anatomy & PhysiologyBiologyISBN:9781260159363Author:Martin, Terry R., Prentice-craver, CynthiaPublisher:McGraw-Hill Publishing Co.Inquiry Into Life (16th Edition)BiologyISBN:9781260231700Author:Sylvia S. Mader, Michael WindelspechtPublisher:McGraw Hill Education