A food sample with an unknown number of contaminating bacteria was serially diluted to 10-6. A volume of 0.1 mL (100 μL) of the dilutions was plated. The 10-6 plate contained 96 colonies. What was the original microbial concentration

Q: starting with four bacterial cells per milliliter in a rich nutrient medium, with a 1-hour lag phase…

A: Bacterial Growth --Bacterial Cell growth is proliferation of bacterium in to daughter cells ,…

Q: What is the difference between a mixed culture and a contaminated culture if they both contain more…

A: In microbiology , a bacterial culture is a growth of microorganisms which have been grown in a…

Q: Can gelatin hydrolysis be correlated with the pathogenicity of a bacterium? Explain your answer

A: Disclaimer: “Since you have asked multiple questions, we will solve the first question for you. If…

Q: A sample of soup (pH 6.2) had 5,000 units of bacteria, after 18 minutes of treatment at 98 °C, 5…

A: Bacteria are the single celled microorganisms which comes under the kingdom Monera of classification…

Q: In a bacterial culture on an agar plate, what is a zone of inhibition?     An area where the…

A: Microbial culture is a method of multiplying microbial organisms by letting them reproduce in…

Q: What is the amount (mL) of pre-culture (108 cell/mL) necessary to inoculate (to add) in a 2-liter…

A: Culture media is a solid or semisolid substance used to support the growth of microorganisms. It is…

Q: Why do cells need to be kept in the freezing devices first then transferred to liquid nitrogen…

A: Rapid freezing of cells can cause ice crystals large crystals can be formed in which cells are…

Q: When can gelatin be used in culture media preparation? [Answer in not more than 2 sentences

A: GELATIN: Gelatin, often known as gelatine, is a transparent, colourless, and flavourless culinary…

Q: Noah wanted to transfer Staphylococcus aureus from a broth to an agar plate. He picked up the broth…

A: The aseptic techniques are applied in the laboratory setup to reduce the risk of contamination. It…

Q: Which of the following would you most expect to find in a fecal contaminated water sample?…

A: Water pollution is described as the fouling of bodies of water. Water pollution occurs when rivers,…

Q: The optimum growth pH for a microorganism is usually:  4,5,7 or 8

A: pH is the scale on which the acidity or alkalinity  is measured. It is the scale between 1 to 14.…

Q: A serial dilution of a sample has an unknown concentration of microorganisms. A countable plate has…

A:

Q: Why are the streak plates for microorganisms in coconut water incubated at 7°C?

A: The benefits of streaking for isolation is to produce isolated colonies of an organism on an agar…

Q: What will pose an ethical issue in these procedures are performed - sterilization?

A: Sterilization is a permanent method of family planning. It is one of the most common method of…

Q: Why are semi-solid media such as TTC deeps suitable to test motility of bacteria?

A: There are several parameters which need to be studied in microbiology about different…

Q: Disinfectant Concentration Growth after time of exposure (minutes) Control 5 minutes 10 minutes…

A: * Disinfectant is a chemical substance that inactivates or to destroy the microorganisms that are…

Q: Vernon wanted to determine the colony forming units of bacteria per gram of soil in their school…

A: CFU (colony-forming unit) or cfu (colony-forming unit) is a metric for the number of viable…

Q: A Pure colony is needed for inoculation in sterile water, a small portion of culture media was…

A: Introduction  Culture is referred to the process of growing the cell outside the animal or plant…

Q: Kousei works at a company that produces sweetened condensed milk. If one or more samples exceed 10…

A: Cell count: The cell count data is generally utilized to predict the number of living microbes…

Q: The following data were obtained by incubating gram-positive bacteria in nutrient medium +…

A: Gram-positive bacteria are bacteria that test positive in the Gram stain test, which has…

Q: If a yellow halo is present around a colony on a mannitol salt agar (MSA) plate, the bacterium…

A: Mannitol salt agar (MSA) is used as a culture medium or growth medium. Growth medium is a medium…

Q: where 5 nutrient agar pates per female student and 3 agar slants per males student are needed to…

A: It is given that 5 nutrient agar plate prepared by per female so Seven female will prepare=7*5=35…

Q: When is sterilization by filtration preferred over sterilization by heat? Why? What makes heat an…

A: Answer :- 1)Filteration is the sterilization process wherein there is the physical removal of…

Q: Laboratories spend millions of dollars and person-hours to identify microbes from clinical samples.…

A: Flagella are organelles that are characterised by their function rather than their appearance. The…

Q: Plastic pipet tips for micropipettes are commonly supplied in packs of 100’s. Once the pack has been…

A: steam sterilization is a method of moist heat sterilization that uses high-pressure steam to…

Q: You were tasked to determine the total microbial load of a bread sample. The sample was homogenized,…

A: Question: Draw a schematic diagram illustrating the proposed experimental setup described above?

Q: Oven sterilization of aqueous culture medium. Effect: Rationale:

A: Oven sterilization utilizes dry heat of about 160 or 170 degrees celsius for one hour or 30 minutes,…

Q: During media preparation, you observed that the agar medium did not solidify after sterilization…

A: Nutrient Agar Medium is the artificial media which is used to grow microbes. It provides essential…

Q: Assume an inoculum with a cell density of 108 cells per mL. The entire generation time takes 30…

A: Binary fission is the most common method of reproduction among bacteria. In this process, a single…

Q: Which of these microbial structures is the most difficult to kill when attempting to sterilize…

A: Answer of the question given below...

Q: Bacterial cells can form colonies on the following media EXCEPT: Select one: Nutrient broth Agar…

A: The nutrient broth is the liquid nutrient media that lacks the solidifying agent. It is used for…

Q: What is the advantage of the plating method over an electronic cell counting method in counting…

A: Bacteria culturing is done in order to grow the bacterial strains that are able to show resistance…

Q: Medium used for cellulase production contained (g/L): NaNO3, 3; MgSO4 7H2O, 0.5; K2HPO4, 1; KCl, 0.5…

A: Culture media is proper nutrient for the growth of the microorganisms, which help to grow a variety…

Q: Given the scenario, compute for the total volume of the culture media solution (milliliter or liter)…

A: We have been given the concentration of the nutrient broth and Agar and we have also been given the…

Q: A laboratory technician performed a series of 10 fold serial  dilutions shown below. he plated 0.1…

A: In this question, we are given colony count from different 10 fold dilutions. The volume plated from…

Q: Starting with 10 bacterial cells per milliliter in a sufficient amount of complete culture medium…

A: Bacteria are organisms that are found almost everywhere on earth and are free-living cells that are…

Q: Why does dry heat require higher temperatures for longer time periods to sterilize than moist heat

A: Sterilization may be defined as the process which help in the complete removal of all…

Q: In spread plate method, inoculating loop is used to spread bacteria from the inoculation site. For…

A:

Q: What is the major difference between an enrichment culture and a selective culture?

A: Culture media is used for cultivating microorganisms. Both selective media and enriched media are…

Q: You were tasked to determine the total microbial load of a bread sample. The sample was homogenized,…

A: Serial dilution is a step-wise dilution of microorganisms in the solution. The dilution factor…

Q: Which isolation technique is best used in isolating microorganisms (in countable good plates) from a…

A: The phrase "isolation" in microbiology refers to the separation of a strain from a natural, mixed…

Q: You have a starter culture containing 8 x 109 cells per mL, from which you take 10 mL to inoculate a…

A: The generation time of culture is considered to be the time at which it doubles and the mean growth…

Q: A serial dilution of a bacterial culture yields the following number of colonies. Which plate(s)…

A: Serial dilution is used to estimate thr number of bacterial cells present in a sample to reduce a…

Q: What was the concentration of bacteria (CFU/mL) in the original suspensions used for dilutions and…

A: The ideal colony size is found between 30 and 300. The CFU/ml is calculated by: (Colony × Dilution…

Q: what do the colors in the kirby bauer plate represent black/dark area =  tan/yellow are small…

A: KIRBY BAUER METHOD- Antibiotic sensitivity test is performed by using the agar diffusion method in…

Q: Examine the given sets of table below. Which disinfectant is the MOST recommended? Support and…

A: A  disinfectant is a substance used for killing microbes and is used for cleaning the workplace,…

Q: Is the mannitol salt agar (MSA) a complex or defined medium? Explain based on Composition. What kind…

A: The selective ingredients of MSA the bile salts and the dye, crystal violet which inhibit the growth…

Q: Why should agar media be completely dissolved before they are dispensed in tubes and plates? What…

A: Introduction  A growth medium, also known as a culture medium, is a solid, liquid, or semi-solid…

Q: You have found that the D-value (decimal reduction value) of an antimicrobial agent to be 4 minutes…

A: In sterilization techniques, D-value or decimal-reduction value refers to the time taken, under…

Q: bacterial culture has a concentration of 3.2 x 108 cells /mL. You dilute this culture as follows:…

A: CFUs are a measure of the number of progenitors present in a given population of cells; if an…

Microbial Growth

The development of microbial growth is influenced by various natural conditions (both physical and synthetic) like pH, temperature, saltiness, gas focus (O2, CO2, and H2), nutrients, water action, and assimilation. Knowing the distinctive physical and chemical factors that influence the development and endurance of microbial growth in the climate will assist with reinforcing endeavors outfitted towards their control. These lines lessen or diminish their harmful impacts on humankind, creatures, and the climate.