Question: What do lactobacillus strains produce from plant-derived feed stock?
About the article "Yogurt", section "Non-dairy yogurt substitutes".

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Various manufacturers have endeavoured to produce plant-based substitutes for yogurt, using soy milk, nut milks such as almond milk, and coconut milk, for consumers who are unable to tolerate dairy products in any form.
Although "Lactobacillus" strains exist that can produce lactic acid from plant-derived feed stock ("e.g."
sauerkraut), since plants do not produce lactose, it is not possible to produce genuine yogurt from plant sources with the same bacteria cultures used to convert milk into yogurt.
Lactobacillus fermentum belongs to the genus "Lactobacillus".
Species in this genus are used for a wide variety of applications.
These applications include food and feed fermentation.
It has been found that some strains for "Lactobacillus fermentum" have natural resistances to certain antibiotics and chemotherapeutics.
They are considered potential vectors of antibiotic resistance genes from the environment to humans or animals to humans.
"Lactobacillus fermentum" can also be a normal inhabitant of the human intestinal tract and some strains have been associated with cholesterol metabolism. 
Lactobacillus sakei is a bacterium species in the genus "Lactobacillus".
It is a facultatively heterofermentative "Lactobacillus" species (placed in Group II, with species able to produce either alcohol or lactic acid from sugars). 
Though probiotics have received renewed attention recently from product manufacturers, research studies and consumers, the idea of health benefits through food starts with the history of mankind.
The history of probiotics can be traced back to the first use of cheese and fermented products, that were well known to the Greeks and Romans who recommended their consumption.
The fermentation of dairy foods represents one of the oldest techniques for food preservation.
The original modern hypothesis of the positive role played by certain bacteria was first introduced by Russian scientist and Nobel laureate Élie Metchnikoff, who in 1907 suggested that it would be possible to modify the gut flora and to replace harmful microbes with useful microbes.
Metchnikoff, at that time a professor at the Pasteur Institute in Paris, proposed the hypothesis that the aging process results from the activity of putrefactive (proteolytic) microbes producing toxic substances in the large bowel.
Proteolytic bacteria such as clostridia, which are part of the normal gut flora, produce toxic substances including phenols, indols and ammonia from the digestion of proteins.
According to Metchnikoff these compounds were responsible for what he called "intestinal auto-intoxication", which would cause the physical changes associated with old age.
It was at that time known that milk fermented with lactic-acid bacteria inhibits the growth of proteolytic bacteria because of the low pH produced by the fermentation of lactose.
Metchnikoff had also observed that certain rural populations in Europe, for example in Bulgaria and the Russian steppes who lived largely on milk fermented by lactic-acid bacteria were exceptionally long lived.
Based on these observations, Metchnikoff proposed that consumption of fermented milk would "seed" the intestine with harmless lactic-acid bacteria and decrease the intestinal pH and that this would suppress the growth of proteolytic bacteria.
Metchnikoff himself introduced in his diet sour milk fermented with the bacteria he called "Bulgarian Bacillus" and found his health benefited.
Friends in Paris soon followed his example and physicians began prescribing the sour milk diet for their patients.
"Bifidobacteria" were first isolated from a breast-fed infant by Henry Tissier who also worked at the Pasteur Institute.
The isolated bacterium named Bacillus bifidus communis was later renamed to the genus "Bifidobacterium".
Tissier found that bifidobacteria are dominant in the gut flora of breast-fed babies and he observed clinical benefits from treating diarrhea in infants with bifidobacteria.
The claimed effect was bifidobacterial displacement of proteolytic bacteria causing the disease.
During an outbreak of shigellosis in 1917, German professor Alfred Nissle isolated a strain of "Escherichia coli" from the feces of a soldier who was not affected by the disease.
Methods of treating infectious diseases were needed at that time when antibiotics were not yet available, and Nissle used the "Escherichia coli" Nissle 1917 strain in acute gastrointestinal infectious salmonellosis and shigellosis.
In 1920, Rettger and Cheplin reported that Metchnikoff's "Bulgarian Bacillus", later called "Lactobacillus delbrueckii subsp.
bulgaricus", could not live in the human intestine.
They conducted experiments involving rats and humans volunteers, by feeding them with "Lactobacilus acidophilus".
They observed changes in composition of fecal microbiota, which they described as “transformation of the intestinal flora”.
Rettger further explored the possibilities of "Lactobacilus acidophilus" and reasoned that bacteria originating from the gut were more likely to produce the desired effect in this environment.
In 1935 certain strains of "Lactobacillus acidophilus" were found to be very active when implanted in the human digestive tract.
Trials were carried out using this organism, and encouraging results were obtained especially in the relief of chronic constipation.
According to Hamilton-Miller et al., in a letter in which they call for the oldest known citation of the word, the term "probiotics" was first introduced in 1953 by Werner Kollath (see Hamilton-Miller et al.
2003) to describe organic and inorganic food supplements applied to restore health to patients suffering from manlnutrition.
Contrasting antibiotics, probiotics were defined as microbially derived factors that stimulate the growth of other microorganisms.
In 1989, Roy Fuller suggested a definition of probiotics that has been widely used: ""A live microbial feed supplement which beneficially affects the host animal by improving its intestinal microbial balance"".
Fuller's definition emphasizes the requirement of viability for probiotics and introduces the aspect of a beneficial effect on the host.
The term "probiotic" originally referred to microorganisms that have effects on other microorganisms, a usage credited to Lilly and Stilwell (1965).
Their conception of probiotics involved the notion that substances secreted by one microorganism stimulated the growth of another microorganism.
The term was used again in 1971 by Sperti to describe tissue extracts which stimulated microbial growth.
The term probiotics was taken up by Parker in 1974 who defined the concept as, “organisms and substances that have a beneficial effect on the host animal by contributing to its intestinal microbial balance”.
Later, the definition was greatly improved by Fuller in 1989, whose explanation was very close to the definition used today.
Fuller in 1989 described probiotics as a "live microbial feed supplement which beneficially affects the host animal by improving its intestinal microbial balance".
He stressed two important facts of probiotics: the viable nature of probiotics and the capacity to help with intestinal balance.
In the following decades, intestinal lactic acid bacterial species with alleged health beneficial properties have been introduced as probiotics, including "Lactobacillus rhamnosus", "Lactobacillus casei", and "Lactobacillus johnsonii". 
Products derived from "Acorus calamus" were banned in 1968 as food additives by the United States Food and Drug Administration.
The questionable chemical derived from the plant was β-asarone.
Confusion exists whether all strains of "A. calamus" contain this substance.
Four varieties of "A. calamus" strains exist in nature: diploid, triploid, tetraploid and hexaploid.
Diploids do not produce the carcinogenic β-asarone.
Diploids are known to grow naturally in Eastern Asia (Mongolia and C Siberia) and North America.
The triploid cytotype probably originated in the Himalayan region, as a hybrid between the diploid and tetraploid cytotypes.
The North American Calamus is known as "Acorus calamus" var.
"americanus" or more recently as simply "Acorus americanus".
Like the diploid strains of "A. calamus" in parts of the Himalayas, Mongolia, and C Siberia, the North American diploid strain does not contain the carcinogenic β-asarone.
Research has consistently demonstrated that "β-asarone was not detectable in the North American spontaneous diploid Acorus var.
Americanus".