''Acetobacter aceti'' is a
Gram-negative bacterium
Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall ...
that moves using its
peritrichous
A flagellum (; ) is a hairlike appendage that protrudes from certain plant and animal sperm cells, and from a wide range of microorganisms to provide motility. Many protists with flagella are termed as flagellates.
A microorganism may have f ...
flagella
A flagellum (; ) is a hairlike appendage that protrudes from certain plant and animal sperm cells, and from a wide range of microorganisms to provide motility. Many protists with flagella are termed as flagellates.
A microorganism may have f ...
.
Louis Pasteur
Louis Pasteur (, ; 27 December 1822 – 28 September 1895) was a French chemist and microbiologist renowned for his discoveries of the principles of vaccination, microbial fermentation and pasteurization, the latter of which was named afte ...
proved it to be the cause of conversion of
ethanol
Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an Alcohol (chemistry), alcohol with the chemical formula . Its formula can be also written as or (an ethyl ...
to
acetic acid
Acetic acid , systematically named ethanoic acid , is an acidic, colourless liquid and organic compound with the chemical formula (also written as , , or ). Vinegar is at least 4% acetic acid by volume, making acetic acid the main component ...
in 1864. It is a benign microorganism which is present everywhere in the environment, existing in alcoholic
ecological niches
In ecology, a niche is the match of a species to a specific environmental condition.
Three variants of ecological niche are described by
It describes how an organism or population responds to the distribution of resources and competitors (for ...
which include flowers, fruits, and
honey bees
A honey bee (also spelled honeybee) is a eusocial flying insect within the genus ''Apis'' of the bee clade, all native to Afro-Eurasia. After bees spread naturally throughout Africa and Eurasia, humans became responsible for the current cosmo ...
, as well as in water and soil. It lives wherever sugar fermentation occurs.
It grows best in temperatures that range from 25 to 30 degrees Celsius and in pH that ranges from 5.4 to 6.3. For a long time it has been used in the fermentation industry to produce
acetic acid
Acetic acid , systematically named ethanoic acid , is an acidic, colourless liquid and organic compound with the chemical formula (also written as , , or ). Vinegar is at least 4% acetic acid by volume, making acetic acid the main component ...
from alcohol. ''Acetobacter aceti'' is an
obligate aerobe
An obligate aerobe is an organism that requires oxygen to grow. Through cellular respiration, these organisms use oxygen to metabolise substances, like sugars or fats, to obtain energy. In this type of respiration, oxygen serves as the terminal e ...
, which means that it requires
oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...
to grow.
''Acetobacter aceti'' is economically important because it is used in the production of
vinegar
Vinegar is an aqueous solution of acetic acid and trace compounds that may include flavorings. Vinegar typically contains 5–8% acetic acid by volume. Usually, the acetic acid is produced by a double fermentation, converting simple sugars to et ...
by converting the
ethanol
Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an Alcohol (chemistry), alcohol with the chemical formula . Its formula can be also written as or (an ethyl ...
in wine or cider into acetic acid. The acetic acid created by ''A. aceti'' is also used in the manufacturing of
acetate rayon
Rayon is a semi-synthetic fiber, made from natural sources of regenerated cellulose, such as wood and related agricultural products. It has the same molecular structure as cellulose. It is also called viscose. Many types and grades of viscose f ...
,
plastics
Plastics are a wide range of synthetic polymers, synthetic or semi-synthetic materials that use polymers as a main ingredient. Their Plasticity (physics), plasticity makes it possible for plastics to be Injection moulding, moulded, Extrusion, e ...
production,
rubber
Rubber, also called India rubber, latex, Amazonian rubber, ''caucho'', or ''caoutchouc'', as initially produced, consists of polymers of the organic compound isoprene, with minor impurities of other organic compounds. Thailand, Malaysia, and ...
production, and
photographic
Photography is the art, application, and practice of creating durable images by recording light, either electronically by means of an image sensor, or chemically by means of a light-sensitive material such as photographic film. It is employed i ...
chemicals. ''A. aceti'' is considered an
acidophile
Acidophiles or acidophilic organisms are those that thrive under highly acidic conditions (usually at pH 5.0 or below). These organisms can be found in different branches of the tree of life, including Archaea, Bacteria,Becker, A.Types of Bacteria ...
, which means it is able to survive in acidic environments, due to having an acidified
cytoplasm
In cell biology, the cytoplasm is all of the material within a eukaryotic cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. The ...
which makes nearly all proteins in the genome to evolve acid stability. ''A. aceti'' has become important in helping to understand the process by which proteins can attain acid stability.
Industrial use
Acetic acid production
''A. aceti'' is used for the mass production of acetic acid, the main component in vinegar. During the fermentation process of vinegar production, it is used to act on wines and
cider
Cider ( ) is an alcoholic beverage made from the fermented juice of apples. Cider is widely available in the United Kingdom (particularly in the West Country) and the Republic of Ireland. The UK has the world's highest per capita consumption, ...
s resulting in vinegar with acetic acid. It can be converted by a silicone tube reactor, which aids the fermentation process with oxidation.
Safety
''A. aceti'' has not been reported as a
human pathogen A human pathogen is a pathogen (microbe or microorganism such as a virus, bacterium, prion, or fungus) that causes disease in humans.
The human physiological defense against common pathogens (such as ''Pneumocystis'') is mainly the responsibility ...
. Human skin does not provide the bacteria with the optimal conditions for it to grow, which makes it safe to handle in factories that use the species to produce acetic acid. However, some evidence indicates it can be harmful to plants and other flora, though it exists naturally in the world.
Growth
Oxidation is used to stimulate the growth of the ''A. aceti''. Samples of the bacteria are placed in a few silicone tubes. These tubes are permeable to oxygen, after which they are left in a region warmer than the typical room temperature and cultured.
Pink disease in pineapples
Because ''A. aceti'' occurs naturally and is widespread in the world, so far, no evidence shows it is a threat to humans, but in recent studies, it has been suspected to cause some detrimental effects on
pineapple
The pineapple (''Ananas comosus'') is a tropical plant with an edible fruit; it is the most economically significant plant in the family Bromeliaceae. The pineapple is indigenous to South America, where it has been cultivated for many centuri ...
s. The
pink disease in pineapples causes the fruit to turn a slight pink color, only to eventually become brown and then rot. Similar experiments have also been tested on other fruits such as apples and pears and results end with rotten fruits. However, the bacterium seems to only be effective if the fruit has any locations exposing its flesh and the temperature surrounding its invasion is warmer than average. With the discovery of other ''Acetobacter'' species, skepticism exists regarding ''A. aceti'' being the only cause of the pink discoloration disease in pineapples. Studies are still being conducted on other species on the genus ''Acetobacter'' because 15 other species have been found in rotting fruits, as well.
References
External links
Type strain of ''Acetobacter aceti'' at Bac''Dive'' - the Bacterial Diversity Metadatabase
{{Taxonbar, from=Q3604286
Rhodospirillales
Bacteria described in 1898