An introduction to the issue of microbes

Lactococcus lactis Include sketches, photos, or descriptions of samples you viewed in the lab. You will need to research this. Eubacteria are placed in a division depending on the type of cell wall they have. Bacteria with a thin peptidoglycan layer are classified as gram - and will stain pink.

An introduction to the issue of microbes

Materials List Each group needs: These strange organisms might have shown up in suspicious looking food or in a pink ring around the water in a dirty toilet bowl. Well, microorganisms are all around us, and we can even study how quickly they grow. At the end of this activity, you will know what specific factors influence the growth of microorganisms, such as bacteria, and know what effects these various factors have on bacteria.

People generally think that bacteria are bad for us or dirty, but in reality, many different types of bacteria are essential and beneficial to us. When we study bacteria closely, we find that they fascinating organisms.

They have special features that make them ideal organisms for scientists and engineers to use in a wide ranage of applications ranging from medicine to environmental and energy engineering. One of these features is that bacteria grow very quickly.

On average, bacteria reproduce every 20 minutes, which each bacterium does by splitting into two identical copies of the parent. That means that one bacterium turns into two, those two split into four, which then split into eight, and so on. If each split takes only 20 minutes, it does not take long before we have millions of bacteria.

Scientists use this knowledge to their advantage to grow large quantities of these organisms for a variety of purposes. Another important feature of bacteria is that they do not need much to thrive: Different strains of bacteria have adapted to survive in very harsh climates, such as high altitudes, deep in the ocean, and at very cold or hot temperatures.

All of these features allow scientists and engineering to use them in a wide range of applications. Not only do these organisms affect the exterior and interior of our bodies, but bacteria such as E. Biosynthesis refers to the process by which cells, such as bacteria, put together simple molecules to make more complex ones.

It is the process of biosynthesis that E. Engineers also add bacteria to biofuel to create useable energy and remove waste from fermentation by-products while generating electricity. And, scientists and engineers modify different types of bacteria to act as clean-up agents for oil spills: This activity demonstrates that bacteria are found everywhere and that it is difficult to kill bacteria, even after washing our hands and applying antibacterial hand sanitizer.

Respiration that requires oxygen. Respiration that does not require oxygen. A unicellular microorganism with no nucleus.

A visible cluster of bacteria. A cell that has a nucleus. One cell divides into two, which is how bacteria reproduce. Converting light energy into chemical energy to fuel an organism's activities.

A cell that lacks a nucleus. Procedure About the Activity Through this activity, students study three different conditions under which bacteria are found and compare the growth of the individual bacteria from each source: Students take swab samples of one of their team member's hands under each of the three conditions and streak the swabs on Petri dishes containing agar gel, which supports bacterial growth.

After a week, the three samples in Petri dishes show growth, giving students an opportunity to quantitatively compare the amount of bacteria growing from each test condition.

Quantitative analysis of these samples, via photographs taken of the Petri dishes at different time points, is conducted by analyzing the images through special imaging software.

Dairy Microbiology

In addition to monitoring the quantity of bacteria from the different conditions, students also record the growth of bacteria over time, which is an excellent tool to study binary fission and the reproduction of unicellular organisms.

Background Bacteria are unicellular organisms that reproduce by a process called binary fission, meaning that each singular bacterium splits into two after its genetic material is duplicated. This method of replication is asexual, since the bacterium does not need a partner's genetic material to be able to reproduce.

Bacteria are prokaryotic organisms, which mean they are cells that have no nucleus.


The time it takes for bacteria to complete binary fission, on average, is 20 minutes. In order to grow, bacteria need three things: Bacteria can grow in a wide range of different environments, and since they do not carry out photosynthesis, they can grow with or without sunlight.

Researchers use two methods to count bacteria: Shine a light through a liquid media with bacteria growing, and measure how much light is scattered by the sample.

More scattering means more bacteria. Use a cell counter, which uses software connected to a microscope, to look at a sample of media with bacteria. The software counts the number of bacteria.In these sections, topics dealt with by Beneficial Microbes include: Worldwide safety and regulatory issues; Human and animal nutrition and health effects; Latest discoveries in mechanistic studies and screening methods to unravel mode of action; Host physiology related to .

Antibiotic resistance occurs when an antibiotic has lost its ability to effectively control or kill bacterial growth; in other words, the bacteria are "resistant" and continue to multiply in the presence of therapeutic levels of an antibiotic.

An Introduction To The World Of Probiotics: Have You Had Your Friendly Bacteria Today? CAPSULE REPORT: While not specifically an organic foods topic, probiotics is a health and wellness issue that you’ll be hearing more about as manufacturers market more “functional foods” to Americans interested in the promise of health without having to.

If the chemicals used to rid drinking water of disease-causing microbes are themselves potentially harmful, is drinking water safe.

An introduction to the issue of microbes

What trade-offs are acceptable with respect to microbial versus chemical water quality. This conference deals with current thinking about these topics. The subjects. Features & Benefits. Features a student-friendly writing style and balanced approach to provide an accessible introduction to microbiology; Presents the latest information on contemporary issues, such as microbes in agriculture and the environment, the human microbiome, and current, real-world applications of genetic engineering and biotechnology.

Growing Bacteria in Petri Dishes. Take samples around you and see what bacteria will grow in an agar-filled Petri dish. This activity will prove that Mom was right “Wash your hands with soap and warm water!” A Petri dish prepared with nutrient agar (a seaweed derivative with beef nutrients added) is an ideal way to reveal the bacteria.

Food Microbiology - Journal - Elsevier