Streptococcus thermophilus is one of the most commercially important of all lactic acid bacteria
Streptococcus thermophilus is a Gram-positive facultative anaerobe. It is a cytochrome-, oxidase- and catalase-negative organism that is nonmotile, non-spore forming and homofermentative. Streptococcus thermophilus is an alpha-hemolytic species of the viridans group. It is also classified as a lactic acid bacteria (LAB).
Streptococcus thermophilus was once described as a bacterium “marked more by the things which it cannot do than by it’s positive actions” (Sherman, 1937). Although it may be certainly be true that S. thermophilus is physiologically and biochemically less versatile than other lactic acid bacteria, the reality is that this organism is actually very versatile. Research during the past two decades has revealed that S. thermophilus has properties that make it one of the most commercially important of all lactic acid bacteria. Streptococcus thermophilus is used, along with Lactobacillus spp., as a starter culture for the manufacture of several important fermented dairy foods, including yogurt and Mozzarella cheese.
The substantial increase in production of Mozzarella cheese and yogurt have led not only to increased use of S. thermophilus cultures, but also to new demands on their performance and production requirements. Industrial strains, for example, should be insensitive to bacteriophage, have stabile fermentation characteristics, and produce products having consistent flavor and texture properties. Although research on the physiology of S. thermophilus has revealed important information on some of these properties, including sugar and protein metabolism, polysaccharide production, and flavor generation, only recently has the genetic basis for many of these traits been determined. Currently, several traits in S. thermophilus have been targeted for strain improvement programs.
S. thermophilus has an important role as a probiotic, alleviating symptoms of lactose intolerance and other gastrointestinal disorders. Immunologist lie Metchnikoff, spoke highly about the possible health benefits of the lactic acid-bacteria (LAB) Lactobacillus bulgaricus and Streptococcus thermophilus in his writings at the turn of the last century. He wrote in his book, The Prolongation of Life, that consumption of live bacteria, such as Lactobacillus bulgaricus and Streptococcus thermophilus, in the form of yogurt was beneficial for gastrointestinal health, as well as for health in general, and for longevity. Some recent research suggests that certain live microorganisms may have immunomodulatory and anticarcinogenic effects, as well as other health benefits. There is presently much active research focusing on the development of target-specific probiotics containing well-characterised bacteria that are selected for their health-enhancing characteristics. These new probiotics are entering the marketplace in the form of nutritional supplements and functional foods, such as yogurt functional food products.
The genome of S. thermophilus is 1.8 Mb, making it among the smallest genomes of all lactic acid bacteria.
- Genus: Streptococcus
- Species: thermophilus
- Strain: LMG 18311
Genome accession number: CP000023
EMBL reference - Taxonomy: 264199
- Genus: Streptococcus
- Species: thermophilus
- Strain: CNRZ1066
Genome accession number: CP000024
EMBL reference - Taxonomy: 299768
References:
http://www.ebi.ac.uk/2can/genomes/bacteria/Streptococcus_thermophilus.html
http://genome.jgi-psf.org/draft_microbes/strth/strth.home.html
http://www.biol.ucl.ac.be/gene/genome/
http://www.pdrhealth.com/drug_info/nmdrugprofiles/nutsupdrugs/pro_0034.shtml
Tags: Probiotic
Bacillus subtilis is a Gram-positive, catalase-positive bacterium commonly found in soil. The natural habitat for B. subtilis is soil. Therefore, longterm survival in soil may be expected to occur. A member of the genus Bacillus, B. subtilis is rod-shaped, and has the ability to form a tough, protective endospore, allowing the organism to tolerate extreme environmental conditions. Unlike several other well-known species, B. subtilis has historically been classified as an obligate aerobe, though recent research has demonstrated that this is not strictly correct.
For many years afterwards, cultures of Bacillus subtilis were sold worldwide as a medicinal product (sold in the U.S. and Mexico, for example, under the brand name Bacti-Subtil) rapidly becoming the world’s leading treatment for dysentery and other intestinal problems. Unfortunately for Americans, this popular bacterial supplement that cures intestinal infections began losing favor in the late 1950’s and 1960’s, upon the advent of synthetic antibiotics which were heavily touted by the giant pharmaceutical companies as “wonder drugs,” even though they cost five times as much as Bacti-Subtil, and took three times longer to accomplish the same results.
Nonetheless, Bacillus subtilis remains one of the most potent and beneficial of all health-promoting and immune-stimulating bacteria. According to clinical studies documented in the medical research report, IMMUNOSTIMULATION BY BACILLUS SUBTILIS PREPARATIONS, by micro-biologist J. Harmann, the cell wall components of ingested Bacillus Subtilis are able to activate nearly all systems of the human immune defense, including the activation of at least three specific antibodies (IgM, IgG and IgA secretion) which are highly effective against many of the harmful viruses, fungi and bacterial pathogens which regularly attempt to invade and infect the human system.
Bacillus subtilis is still used widely today in Germany, France and Israel, where safe, effective all-natural therapeutic products are more highly esteemed by the health-savvy public than the more expensive synthetic drugs espoused by the orthodox medical establishment with all of their dangerous side effects.
In short, the incredible Bacillus subtilis, which is commonly found in the outside environment rather than in the human intestinal system, continues to benefit mankind ever since its unusual discovery by the Germans in 1941. What’s more, it is only one small example of the multitude of “friendly” microorganisms which can create tremendous benefits for humans when ingested, even though they are not necessarily “native” microorganisms to the human body.
B. subtilis has also been called the Hay or Grass bacillus; Bacilluss globigii or Bacillis licheniformis are binomial synonyms.
Tags: Probiotic
Bifidobacterium longum keeps the human digestive system running smoothly
One of the most important residents in the human gastrointestinal tract, B. longum keeps the digestive system running smoothly, blocks the growth of harmful bacteria, and boosts the immune system. The organism ferments sugars into lactic acid and has many health benefits for humans and is often the dominant bacterium found in humans. It is a Gram-positive, anaerobic, branched rod-shaped bacterium.
Researchers have identified a number of proteins that are specialised to help B. longum interact with the human host and persist against harmful bacteria and future reseach will now closely look at which genes allow B. longum to live in different environments such as dairy products, vegetables and the human gastrointestinal tract.
Bifidobacterium longum is among the first to colonise the sterile digestive tract of newborns and predominates in breast-fed infants. Formula-fed infants have a different microflora, and this may be related to the higher risk of diarrhea and allergies in these babies.
Recognising the many benefits to good health, lactic acid bacteria are included in dairy foods and taken as supplements in powder, liquid extracts, or tablets and this has also resulted in people supplementing their diets with these microbes, which are also called probiotics (meaning ‘in favour of life’). Live cultures in yogurt have been used as a remedy for hundreds of years to support immune function and doctors recommend bacterial supplements to patients who take antibiotics, suffer from bacterial, viral or fungal infections or have various digestive problems.
Other potential uses of B. longum are being investigated in separate studies. Japanese researchers showed that the microbe might be useful as a gene delivery vector for cancer therapy. They injected the bacterium into the tail veins of rats and demonstrated that B. longum is accumulated in the tumor.
Comparative studies of lactic acid bacteria may lead to better understanding the microbes’ roles in food fermentation and human health.
Tags: Probiotic
Bifidobacterium infantis is found in the intestines of infants and adults. It is also present in the vaginal tract. This probiotic bacterium is a specific inhabitant of the large intestine where it can be found in high concentration among infants. This species of Bifidobacterium is predominant in the feces of breast-fed infants. Like other Bifidobacteria species, this organism can produce acids that may retard the colonization of certain foreign or harmful bacteria in the colon. Research suggests that the presence of Bifidobacterium infantis in the colon helps reduce the incidence of infantile diarrhea.
B. infantis 35624, sold as Align, was found to improve some symptoms of irritable bowel syndrome in women in a recent study.
Tags: Probiotic
Bifidobacterium is a genus of Gram-positive, non-motile, often branched anaerobic bacteria. Bifidobacteria are one of the major genera of bacteria that make up the gut flora, the bacteria that reside in the colon. Bifidobacteria aid in digestion, are associated with a lower incidence of allergies and also prevent some forms of tumor growth.
Bifidobacterium bifidum
- Supports healthy liver function and detoxification.
- Produces lactic and acetic acids that promote normal elimination.
- Assists the absorption of calcium and other vitamins and minerals.
- Lowers the pH in the large intestine to promote a healthy digestive environment.
- Increases nutritional values by producing essential B vitamins.
- Stimulates regularity and discourages growth of harmful bacteria.
Tags: Probiotic
Bifidobacterium breve - Is beneficial for the treatment of inflammatory bowel disease; prevents rotavirus induced diarrhea and helps maintain a healthy immune system.
Newborns, especially those that are breast-fed, are colonized with bifidobacteria directly after birth. Bifidobacteria were first isolated from the feces of breast-fed infants.
B breve can colonise the immature bowel very effectively and is associated with fewer abnormal abdominal signs and better weight gain in very low birthweight (VLBW) infants, probably as a result of stabilisation of their intestinal flora and accelerated feeding schedules.
Arch Dis Child 1997;76:F101–F107
Tags: Probiotic
Lactobacillus salivarius has been used as a supplement in functional foods and probiotic drinks in Asia. L. salivarius was originally isolated from the intestinal tract of humans, and it can also be found in dairy products and vegetable matter. It produces lactic acid and bacteriocins, and has moderate lactase activity.
Lactobacillus salivarius found in the mouth and small intestine, has been shown to improve bleeding gums, tooth decay, bad breath, thrush and canker sores. L. salivarius breaks down proteins and produces B vitamins, enzymes and lactic acid. Its strong antimicrobial effects have been demonstrated clinically.
Tags: Probiotic
Lactobacillus rhamnosus is a probiotic bacterium that was originally considered to be a subspecies of L. casei, but later genetic research found it to be a species of its own. L. rhamnosus inhibits the growth of most harmful bacteria in the intestine. It is used as a natural preservative in yogurt and other dairy products to extend the shelf life.
Tags: Probiotic
Lactobacillus plantarum is a widespread member of the genus Lactobacillus, commonly found in many fermented food products as well as anaerobic plant matter. It is also present in saliva (from which it was first isolated). It has the ability to liquefy gelatin. L. plantarum has one of the largest genomes known among the lactic acid bacteria and is a very flexible and versatile species.
L. plantarum is commonly found in many fermented food products including sauerkraut, pickles, brined olives, Korean kimchi, Nigerian ogi, sourdough and other fermented plant material and also in some cheeses and fermented sausages. The high levels of this organism in food also makes it an ideal candidate for the development of probiotics
Tags: Probiotic
Lactobacillus helveticus is a lactic-acid producing rod shaped bacterium of the genus Lactobacillus. It is most commonly used in the production of Swiss cheese and Emmental cheese but is also sometimes used in making other styles of cheese, such as Cheddar, Parmesan, romano, provolone, and mozzarella. The primary function of L. helveticus culture is to prevent bitterness and produce nutty flavors in the final cheese. In Swiss and Emmental cheese production, L. helveticus is used in conjunction with a Propionibacter culture, which is responsible for developing the holes (known as “eyes”) through production of carbon dioxide gas.
Ingestion of powdered milk fermented with L. helveticus was shown to decrease blood pressure due to the presence of manufactured tripeptides that have ACE inhibitor activity.
The bacterium’s specific name comes from “Helvetia”, the Latin name for the region occupied by the ancient Helvetii (and for modern Switzerland).
The species Lactobacillus helveticus has been well studied and several probiotic effects are reported in the literature: ability to survive in the stomach and to reach the intestine alive, exerting antimicrobial activities against pathogens, alleviating symptoms of lactose intolerance, helping to prevent and reduce the duration of diarrhoea, possibly reducing the cholesterol level, and helping the natural defences.
Tags: Probiotic