Why does bacteria grow better in the dark

Bacteria bacterium, singular Bacteria are unicellular, generally microscopic organisms -the most common organisms on earth and are intimately connected to the lives of all organisms. Most bacteria are less than 1 micron 0. Hundreds of thousands of bacteria can fit into a space the size of the period at the end of this sentence. Some bacteria can survive harsh conditions for decades or even centuries.

Bacteria grows best in warm, moist, dark places. Of the thousands of bacterial species on the earth, only a small fraction cause disease. Nevertheless, the history of human cultures around the world has been greatly shaped by bacterial infections.

Bacteria can cause diseases- the plague, tuberculosis, strep. Antibiotics can be used to combat bacteria, but often, the bacteria will change so that the antibiotics cannot fight it anymore. Bacteria are often maligned as the causes of human and animal disease However, certain bacteria produce antibiotics; others live symbiotically in the guts of animals including humans or elsewhere in their bodies, or on the roots of certain plants, converting nitrogen into a usable form.

Bacteria put the tang in yogurt and the sour in sourdough bread; bacteria help to break down dead organic matter; bacteria make up the base of the food web in many environments. Bacteria are of such immense importance because of their extreme flexibility, capacity for rapid growth and reproduction, and great age - the oldest fossils known, nearly 3.

Without the decomposing bacteria, the earth would be covered with waste! Also, we would run out of oxygen because plants depend on Carbon dioxide to make oxygen, and the bacteria helps to produce carbon dioxide. The decision whether bacteria are friend or foe becomes more difficult when both the positive and negative aspects of the relationship between humans and bacteria are considered.

Let's discuss three types of symbiotic relationships: commensalism, mutualism, and parasitism. Commensalism is a relationship that is beneficial to the bacteria that live off of the host, but does not help or harm the host.

Most of the bacteria that reside within the bodies of humans are commensalistic. In a mutualistic relationship, both the bacteria and the host benefit. For example, there are several kinds of bacteria that live inside the mouth, nose, throat, and intestines of humans and animals. These bacteria receive a place to live and feed while keeping other harmful microbes from taking up residence. A parasitic relationship is one in which the bacteria benefit while the host is harmed.

Pathogenic parasites, which cause disease, do so by resisting the host's defenses and growing at the expense of the host. These bacteria produce poisonous substances called endotoxins and exotoxins that are responsible for the symptoms that occur with an illness.

When all of the facts are considered, bacteria are more helpful than harmful. Humans have exploited bacteria for a wide variety of uses, such as: making cheese and butter, decomposing waste in sewage plants, and developing antibiotics. Bacteria have been able to survive without us, but we could never live without them. Bacteria is also used to make many of the things we use every day! Vinegar, which is used as both a flavor enhancer and an important food preservative, results from the conversion of ethyl alcohol to acetic acid by acetic-acid bacteria.

There are exceptions, however. Some bacteria thrive in extreme heat or cold, while others can survive under highly acidic or extremely salty conditions. The state of Florida neither endorses links nor approves of links to external sources. External links are made available for the convenience of the internet user. FAT TOM is a mnemonic device used in the food service industry to describe the six favorable conditions required for the growth of foodborne pathogens.

It is an acronym for food, acidity, time, temperature, oxygen and moisture. Does UV light affect bacterial growth? This will reduce the ability of the DNA to multiply and cause disease. How does UV light affect bacteria? The mechanism of UV light inactivation of microorganisms is based on the formation of dimers in RNA and DNA, causing damage that can interfere with transcription and replication and, furthermore, cause bacterial death Cutler and Zimmerman, Does bacteria need oxygen to grow?

Whereas essentially all eukaryotic organisms require oxygen to thrive, many species of bacteria can grow under anaerobic conditions. Bacteria that require oxygen to grow are called obligate aerobic bacteria. In fact, the presence of oxygen actually poisons some of their key enzymes.

Some bacteria S. Does sunlight kill germs? Unfortunately, ultraviolet light can only kill the germs it contacts directly. If germs find hiding places, such as shaded cracks, they can stay safe from the Sun's ultraviolet rays. The Sun's ultraviolet radiation and increased water temperatures work together to kill harmful bacteria in the water. What are the factors affecting microbial growth? Next, the team examined which genes these bacteria had in common, other than those essential genes that all bacteria share in order to thrive.

With help from colleagues at UD's Sequencing and Genotyping Center, they determined that of the non-essential genes, there are two related to the absorption of blue light. This is a repair mechanism but probably doesn't help with growth in the light, said Maresca. The other gene is called a cryptochrome, which has been shown to regulate circadian rhythms in animals, plants, fungi, and even humans.

The cryptochrome is likely responsible for the growth rate difference in lit conditions. It's circumstantial but supportive. So why do these bacteria, which are typically found in top few feet of water in freshwater environments, sense light and react this way? Those well-lit freshwater environments contain organisms such as algae that pull carbon dioxide from the air and produce organic carbon -- food for bacteria.

The team has a working hypothesis that the bacteria in this study may turn up their machinery to coincide with the production of food by other species nearby. It's like gearing up and running toward a buffet freshly stocked with food instead of walking up later to see what's left.

The team is collaborating with a colleague at another university to learn more about how these bacteria interact with algae in the same environment. And to think -- this line of research came about by accident.

Materials provided by University of Delaware.