The growth rate of the phototrophic purple bacterium Rhodobacter is about twice as fast when the organism is grown phototrophically in a medium containing malate as the carbon source as when it is grown with CO2 as the carbon source (with H2 as the electron donor). Discuss the reasons why this is true, and list the nutritional class in which we would place Rhodobacter when growing under each of the two different conditions.
To explain:
The growth rate of phototrophic purple bacterium Rhodobacter is about twice as fast when the organism is grown phototrophically in a medium which contain malate as the carbon source or as it is grown with CO2 as the carbon source (with H2 as the electron donor). Discuss the reason why this is true, and list the nutritional class in which we would place the bacterium Rhodobacter when growing under both the two different conditions.
Introduction:
The purple photosynthetic bacteria are Proteobacteria that have the ability of producing their own food through the process of photosynthesis. They are pigmented with bacteriochlorophyll a or b together with the various carotenoids. It gives them colors that range between orange, red brown, and purple. It may be divided into two groups include purple non-sulfur bacteria (Rhodospirillaceae) and purple sulfur bacteria chromatiales.
Explanation of Solution
In taxonomy, the Rhodobacter belongs to the genus of Rhodobacteraceae. It is used as a model organism to study the bacterial photosynthesis that include Rhodobacter capsulatus and Rhodobacter sphaeroides. Rhodobacter is a purple bacterium, which can obtain the energy through the photosynthesis. An organism, which is able to carry out the process of photosynthesis, is called as the phototrophs. It can be further divided into photoheterotrophs and photoautotrophs.
An organism that carry out the photosynthesis by using sunlight as the source of energy is called as photoautotrophs and it can grow by using carbon dioxide as the only source of carbon and using sunlight as its energy source. The water and carbon dioxide are converted into organic materials. This process is used in the cellular functions such as respiration and biosynthesis.
The photoheterotrophic organisms’ uses sunlight as the energy but it cannot use carbon dioxide as the source of organic compound. Instead, it uses carbon as the organic source. Thus, Rhodobacter is grouped as the photoautotroph when it uses the carbon dioxide as its carbon source. The organism Rhodobacter grown in a medium containing malate as the carbon source use then, it can be placed in the nutritional class of photoheterotrophs. Therefore, the bacterium Rhodobacter is growing twice as fast and well as the photoheterotrophs than as photoautotrophs.
Want to see more full solutions like this?
Chapter 14 Solutions
Brock Biology of Microorganisms (15th Edition)
- If the result of an unknown bacteria is “poor growth” and “red growth,” can this result be interpreted as “organism does not ferment mannitol?” Explain why or why not. If the result of an unknown bacteria is “good growth” and “yellow growth,” is the unknown bacteria more likely Staphylococcus aureus or Staphylococcus epidermidis?arrow_forwardA 3.0 L batch bioreactor is used to grow E. coli bacteria, which have an initial concentration of 12.5 g cells/L. The growth medium contains two carbon sources, which causes diauxic growth, with each carbon source limiting cell growth. Sufficient supplies of oxygen, ammonium nitrate (NH4NO3) as a nitrogen source and all other macro and micronutrients are available. The bacteria prefer to grow on glucose (C6H12O6, supplied at 80 g/L), so it is consumed first, followed by glycerol (C3H803, supplied at 68 g/L). Since the E. coli were already growing on glucose, the lag time associated with glucose consumption is only 10 minutes. The lag time associated with glycerol consumption is 35 minutes. Further information: The chemical formula for E. coli in this bioreactor is CH1.666N0.2000.57. The specific growth rate on glucose is 0.41 h-1, and on glycerol is 0.32 h-1?The yield of cells on glucose is 0.48 g cells/g glucose, and yield on glycerol is 0.39 g cells/g glycerol. You may assume that…arrow_forwardA 3.0 L batch bioreactor is used to grow E. coli bacteria, which have an initial concentration of 12.5 g cells/L. The growth medium contains two carbon sources, which causes diauxic growth, with each carbon source limiting cell growth. Sufficient supplies of oxygen, ammonium nitrate (NH4NO3) as a nitrogen source and all other macro and micronutrients are available. The bacteria prefer to grow on glucose (C6H12O6, supplied at 80 g/L), so it is consumed first, followed by glycerol (C3H8O3, supplied at 68 g/L). Since the E. coli were already growing on glucose, the lag time associated with glucose consumption is only 10 minutes. The lag time associated with glycerol consumption is 35 minutes. Further information: The chemical formula for E. coli in this bioreactor is CH1.666N0.20O0.57. The specific growth rate on glucose is 0.41 h-1 , and on glycerol is 0.32 h-1 . The yield of cells on glucose is 0.48 g cells/g glucose, and yield on glycerol is 0.39 g cells/g glycerol. You may assume that…arrow_forward
- You are characterizing a newly discovered organism . You have noticed that the organism grows on two carbon sources - sucrose and mannitol . Whenever you add both sugars to the medium , sucrose will be completely metabolized before mannitol . a ) What is this growth pattern called ? b ) Describe a possible growth curve of sequential metabolism of the sugars .arrow_forwardSydney Brenner isolated Salmonella typhimurium mutants that were implicated in the biosynthesis of tryptophan and would not grow on minimal medium. When these bacterial mutants were tested on minimal medium to which one of four compounds (indole glycerol phosphate, indole, anthranilic acid, and tryptophan) had been added, the growth responses shown in the following table were obtained. Mutant Minimal medium Anthranilic acid Indole glycerol phosphate Indole Tryptophan trp-1 − − − − + trp-2 − − + + + trp-3 − − − + + trp-4 − − + + + trp-6 − − − − + trp-7 − − − − + trp-8 − + − − + trp-9 − − − − + trp-10 − − − − + trp-11 − − − − + Give the order of indole glycerol phosphate, indole, anthranilic acid, and tryptophan in a biochemical pathway leading to the synthesis of tryptophan. Indicate which step in the pathway is affected by each of the mutations.arrow_forwardEscherichia coli O157:H7 is a foodborne pathogen and can cause serious illness in humans by producing toxins that can severely damage the lining of intestines and kidneys. What are the oxygen requirements of coli? What result would you observe in the MTM agar deep test? Explain. Research on the growth requirements of this bacterium is required. What is the role of oxygen and cytochrome c oxidase in aerobic respiration? Why does the nitrate reduction tube turn red after the addition of zinc? Clostridium tetani is a common soil bacterium and causes tetanus. Would you expect tetani to possess the enzyme catalase? Explain. Research on the growth requirements of this bacterium is required.arrow_forward
- If two cultures of a facultative anaerobe were grown under identical conditions except that one was exposed to oxygen and the other was completely deprived of oxygen, what differences would you expect to see between the two cultures? (What metabolic pathway would be occurring in each? Why?)arrow_forwardWhat is the role of oxygen in aerobic respiration? What type(s) of metabolism can occur in the absence of oxygen? Name two enzymes that are present in obligate aerobes but lacking in obligate anaerobes. What is the function of each enzyme Describe the difference between the appearance of surface and subsurface colonies in a pour plate. If this is the same bacterial species, why do these differences in colonial growth occur?arrow_forwardImagine you are trying to use an organism to remove organic matter in a wastewater treatment plant (i.e., poop). You would like to maximize the amount of waste consumed while also minimizing the amount of cells produced. Assuming these organisms exist and all other things are equal, what combination of chemoorganotrophic organism and environment would make the most sense to use? An organism that only has the Entner-Duoduroff pathway under anaerobic conditions. This was a trick question – the organism would have to be a chemolithotroph since it is consuming a chemical. An organism that only has the Entner-Duoduroff pathway under aerobic conditions. An organism that only has the Embden Meyer Parnas pathway under anaerobic conditions. An organism that only has the Embden Meyer Parnas pathway under anaerobic conditions.arrow_forward
- Pseudomonas aeruginosa is capable of aerobic respiration and anaerobic respiration but not fermentation. It can produce H2S, does not produce tryptophanase, and is motile by a flagellum. Based on the above characteristics, describe your expected results for Pseudomonasaeruginosa in a SIM deep.arrow_forwardWhich growth condition shown above has the largest doubling time? How would you explain the observed growth data based on information about metabolism and oxygen requirements? Definitely take into consideration the relative growth of all three growth conditions. Surprisingly, cultures grown in anerobic conditions are non-motile, whereas cultures grown in normal O2 saturation have several peritrichous flagella and swim motility. Explain briefly the mechanism of flagellar motility in terms of energy source for flagellar motility and why it may be lower in anaerobic conditions for L. monocytogenes.arrow_forwardA culture consisting of 100 litres of nutrient medium containing 12 g l-1 of growth limiting substrate is inoculated with 10g of bacteria in a batch fermenter. The yield of biomass from substrate is 0.05 g g-1 . The maintenance coefficient is 2.0 g g-1 h -1 . The specific rate of product formation due to maintenance is 1.0 h-1 . The maximum specific growth rate of the organism is 0.3 h -1 . YPX= 7.7 and product formation is directly linked with metabolism. a) What is the time required to produce 15 g of biomass? !!!!! ANS IS 3.07 HRS!!!! STEPS on how to reach this pleasearrow_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