Concept explainers
Pasteur’s experiments on spontaneous generation contributed to the methodology of
To explain:
How Pasteur’s experiments affected the methodology of microbiology, origin of life, and food preservation techniques.
Concept introduction:
Louis Pasteur is a French microbiologist, who, having renowned discoveries of microbial fermentation, pasteurization, and vaccination. Pasteur is the responsible person for disproving the spontaneous generation. He conducted many experiments related to microbial contaminations. Pasteur’s vaccine discovery reduces the mortality rate of rabies and anthrax.
Explanation of Solution
Louis Pasteur defeated the spontaneous generation theory by swan necked experiment. He strongly believed that the microorganisms were already present in the environment. So, he conducted some experiments to eliminate or kill the contaminating microorganisms by sterilization technique.
In Spallanzani’s experiment, Louis Pasteur used modified glass flask with a curved neck. This flask is filled with broth and heated. The entry of microorganisms are prevented due to the curved neck of the flask and the heated broth remained clear. When the curved neck of the flask was broken, the broth became contaminated with microorganisms with a cloudy appearance. From this, Pasteur concluded that the contamination arose only because of entry of air particles. Thus, this principle of biogenesis became the leap of the biology history.
Louis Pasteur experiments on spontaneous generation were contributed to the methodology of microbiology, origin of life understanding, and various techniques for food preservation. Alcohol fermentation is considered as the major contribution of Pasteur in the methodology of microbiology. In this, he introduced optimal methods for the enhanced fermentation of beer and other juices. He found that the yeast cells are responsible for catalyzing the alcoholic fermentation. He also worked on the metabolism of tartrate.
After the discoveries of fermentation, Pasteur opposed the spontaneous generation. He gave the concept the putrefying substances in the air and conducted a swan-necked or ‘S’ flask called Pasteur flask. The Pasteur flask was filled with nutrient solution and sterilized by heating. The heating process did not allow the entry of air, dust and microbes and it ensured the sterile nutrient solution. The air particles which had bacteria were trapped in the bend neck of the flask and it could not enter even when the flask was cooled down. The results of this experiment were inconsistent with the theory of spontaneous generation because “fresh air was not needed for the phenomenon to occur. Thus, Louis Pasteur defeated the theory of spontaneous generation by conducting a swan-necked flask experiment for sterilization.
Pasteur also gave a concept of sterilization- a process of removing and killing of microbes or contaminants from an object. He also worked on several sterilization techniques that were used in basic science and microbiology field. Pasteurization is one of major contribution on food microbiology for food preservation. It is a process of heating a liquid to destroy or eliminate the harmful pathogens including enzymes that are responsible for spoilage. This prevents the cause of spoilage as well as the souring. Today, pasteurization technique is regularly used in dairy and food industries for checking the control of microbes and food preservation.
Want to see more full solutions like this?
Chapter 1 Solutions
EBK BROCK BIOLOGY OF MICROORGANISMS
- examples of synamtomorphy.arrow_forwardE. Bar Graph Use the same technique to upload the completed image. We will use a different type of graph to derive additional information from the CO2 data (Fig A1.6.2) 1. Calculate the average rate of increase in COz concentration per year for the time intervals 1959-1969, 1969- 1979, etc. and write the results in the spaces provided. The value for 1959-1969 is provided for you as an example. 2. Plot the results as a bar graph. The 1959-1969 is plotted for you. 3. Choose the graph that looks the most like yours A) E BAR GRAPH We will use a different type of graph to derive additional information from the CU, data (rig. nive). Average Yearly Rate of Observatory, Hawall interval Rate of increase per year 1959-1969 0.9 1969-1979 1979-1989 1989-1999 1999-2009 Figure A1.6.2 1999-2009 *- mrame -11- -n4 P2 جية 1989-1999 1979-1989 1969-1979 1959-1969 This bar drawn for you as an example 1.0 CO, Average Increase/Year (ppmv) B) E BAR GRAPH We will use a different type of graph to derive…arrow_forwardUse the relationships you just described to compute the values needed to fill in the blanks in the table in Fig A1.4.1 depth (a) 1.0 cml 0.7 cml cm| base dimensions (b, c)| 1.0 cm| 1.0 cm| 1.0 cm 1.0 cm| 1.0 cm| 1.0 cm volume (V) 1.0_cm' cm'| cm'| density (p) 1.0 g/cm'| 1.0 g/cm 1.0 g/cm' mass (m)| 0.3 g Column 1: depth at 1.0 cm volume mass Column 2: depth at 0.7 cm volume mass Column 3: unknown depth depth volumearrow_forward
- San Andreas Transform Boundary Plate Motion The geologic map below of southern California shows the position of the famous San Andreas Fault, a transform plate boundary between the North American Plate (east side) and the Pacific Plate (west side). The relative motion between the plates is indicated by the half arrows along the transform plate boundary (i.e., the Pacific Plate is moving to the northwest relative to the North American Plate). Note the two bodies of Oligocene volcanic rocks (labeled Ov) on the map in the previous page located along either side of the San Andreas Fault. These rocks are about 23.5 million years old and were once one body of rock. They have been separated by displacement along the fault. 21. Based on the offset of these volcanic rocks, what is the average annual rate of relative plate motion in cm/yr? SAF lab 2.jpg Group of answer choices 0.67 cm/yr 2 cm/yr 6.7 cm/yr 1.5 cm/yr CALIFORNIA Berkeley San Francisco K Os Q San Andreas Fault Ov…arrow_forwardThese are NOT part of any graded assignment. Are there other examples of synapomorphy. What is it called when the traits retained are similar to ancestors?arrow_forwardPlease hand draw everying. Thank you! Draw a gram positive bacterial cell below. Your cell should have the following parts, labeled: A coccus shape A capsule The gram positive cell wall should have the peptidoglycan labeled, as well as its component parts (NAM, NAG, and teichoic acid) A cell membrane Fimbriae A nucleoid Ribosomes Inclusionsarrow_forward
- Draw a gram negative bacterial cell below. Your cell should have the following parts, labeled: A bacillus shape Fimbriae Amphitrichous flagella 2 membranes (outer and inner) The outer membrane should have lipopolysaccharide (LPS) with lipid A and O antigens Periplasmic space The thin peptidoglycan cell wall between the 2 membranes A nucleoid Ribosomes Inclusionsarrow_forwardBacterial species Cell wall type Example: S. mitis Gram positive S. epidermidis H. pylori M. bovis S. marcescens Shape and arrangement Coccus, streptococcus Drawing 0000000arrow_forwardDraw a gram positive bacterial cell below. Your cell should have the following parts, labeled: A coccus shape A capsule The gram positive cell wall should have the peptidoglycan labeled, as well as its component parts (NAM, NAG, and teichoic acid) A cell membrane Fimbriae A nucleoid Ribosomes Inclusionsarrow_forward
- Microbiology for Surgical Technologists (MindTap ...BiologyISBN:9781111306663Author:Margaret Rodriguez, Paul PricePublisher:Cengage Learning
- Medical Terminology for Health Professions, Spira...Health & NutritionISBN:9781305634350Author:Ann Ehrlich, Carol L. Schroeder, Laura Ehrlich, Katrina A. SchroederPublisher:Cengage Learning