Phototrophic bacteria in soils, waters, sediments, fertilizers (efficient microorganisms)
Phototrophic bacteria are those whose energy for growth comes from light and their carbon sources come from carbon dioxide (CO2) (photoautotrophic or photosynthetic) or organic carbon (photoheterotrophic). All phototrophs use an electron transport chain or a proton pump to establish an electrochemical gradient that is used by ATP synthetase to provide cellular energy. The donors of electrons and hydrogenions are inorganic compounds, which is why they are called lithotrophs (photolytoautotrophs).
Most phototrophic organisms are autotrophic (photoautotrophs), capable of fixing atmospheric carbon (CO2) using energy from light. These microorganisms are different from the chemotrophs, which obtain the energy by oxidation of chemical compounds donors of electrons present in their environment. Photoautotrophic organisms can synthesize their components from inorganic substances using light as an energy source. Green plants and phototrophic bacteria are photoautotrophic. Such organisms get their energy from light and use CO2 as their main source of carbon.
Oxygenic phototropic organisms (oxygen producers) use chlorophyll to capture the energy of light and oxidize water, which they decompose into molecular oxygen. On the other hand, anoxigenic phototrophic organisms (non-oxygen producers), have a substance called bacteriochlorophyll that absorbs predominantly at wavelengths not visible to capture energy from light, they live in aquatic environments and using light oxidize inorganic chemicals such as sulfur of hydrogen (H2S) instead of water.
In an ecological context phototrophic organisms produce nutrients for heterotrophic life, such as plants.
The cyanobacteria (blue-green algae) are photoautotrophic and photoheterotrophic organisms that perform oxygenic photosynthesis (producing oxygen). They are found in many environmental conditions, including natural waters, seas, soil and lichens. These microorganisms can use water as a source of electrons to carry out CO2 reduction reactions.
A photoautotrophic organism (or photolithotrophic) is an autotrophic organism that uses the energy of light and an inorganic electron donor (eg H2O, H2, H2S), and CO2 as a carbon source, such as plants.
A photoheterotrophic organism (or photoorganotrofo), unlike photoautotrophs (photolithotrophs), are organisms that depend solely on light for their energy and mainly organic compounds for their carbon source. Photohetereotrophs produce ATP through photophosphorylation, but use organic compounds to obtain atoms to build their structures and other biomolecules.
Classification of living beings according to their source of energy and their carbon source
Phototrophs (light as an energy source)
Photoautotrophs or photolitotrophs (simple chemical compounds as a carbon source).
Photoheterotrophs or photoorganotrophs (organic chemical compounds as a carbon source).
Chemotrophs (chemical compounds as an energy source)
Chemolithotrophs (simple chemical compounds as a carbon source).
Chemoorganotrophs or heterotrophs (organic chemical compounds as a carbon source).
Phototrophic bacteria are phototrophic organisms (photolithotrophs or photoorganotrophs).
Classification of phototrophic bacteria
- Cyanobacteria (blue-green algae). Includes oxygenic phototrophic organisms for producing oxygen:
This group can use light as the sole source of energy.
They can use light as an energy source in the presence of air.
They produce oxygen.
- Rhodospirillales. It includes the anoxigenic, non-oxygen producing phototrophic bacteria (aerobic anoxygenic phototrophic bacterium and anaerobic anoxygenic bacterium).
Includes all phototrophic bacteria. Some can grow in the presence of air and others cannot grow.
They can use light as their sole source of energy.
They can use light as their sole source of energy in the absence of air (they use light only in anaerobiosis)
They do not produce oxygen.
This order includes three families of phototrophic bacteria:
- Family Rhodospirillaceae - Non-sulphurous purpuric bacteria.
Rhodospirillum spp.
Rhodopseudomonas spp.
Rhodomicrobium spp.
Phototrophy in anaerobiosis.
They grow in darkness in media with yeast extract, but grow better with light;
Purple color only with light because purpuric chlorophyll is needed only with light.
Red with light.
They cannot use sulfur (H2S) as an electron donor.
They possess bacteriochlorophyll a or b located in continuous membrane structures with the cytoplasmic membrane.
- Family Chromatiaceae - Sulphurous purpuric bacteria.
Chromatium spp.
Thiocystis spp.
Thiosarcina spp.
Thiospirillum spp.
Thiocapsa spp.
Lamprocystis spp.
Thiodictyon spp.
Thipedia spp.
Amoebobacter spp.
Ectothiorhodospira spp.
Phototrophy in anaerobiosis.
They grow in the presence of light.
Only one species grows in darkness.
They require sulfur as the sole source of electrons and can oxidize it to sulfate.
They possess bacteriochlorophyll a or b located in continuous membrane structures with the cytoplasmic membrane.
- Family Chlorobiaceae - Sulphurous green bacteria.
Chlorobium spp.
Prosthecochloris spp.
Chloropseudomonas spp.
Pelodictyon spp.
Clathrochloris spp.
Phototrophy in strict anaerobiosis.
They grow in the presence of light; they do not grow in darkness.
They require sulfur as an electron donor.
They have bacteriochlorophyll c or d localized in Chlorobium vesicles fixed to the cytoplasmic membrane.
Efficient microorganisms
The efficient microorganisms are several groups of bacteria (actinomycetes, phototrophic bacteria and lactic bacteria) and fungi (filamentous and yeast), which include a group of species that are considered aerobic or anaerobic regenerators of natural origin. It is a natural probiotic set that includes only microorganisms that exist in nature, and does not include genetically manipulated microorganisms. Its ecological functions are beneficial for ecosystems and other higher organisms (e.g., plants).
The efficient microorganisms are cultivated in liquid media and among them you can find more than eighty species of microorganisms from five groups: actinomycetes, phototrophic bacteria, lactic bacteria, yeasts and filamentous fungi, prepared in mixed cultures of aerobic and anaerobic microorganisms.
This technology, initially developed in Japan, was used as an alternative to pesticides and chemical fertilizers, since its effectiveness is such that it eliminates the need to use chemical and industrial products.
Its application has been extended to many areas and human activities, such as agriculture, livestock, poultry, pig farming, aquaculture, animal health, food preservation, odor control, waste recycling, water treatment and effluents, environment , industry, etc.
It is one of the most effective technological procedures for restoring the natural balance in ecosystems, by restoring the microbial balance capable of regenerating any contaminated medium, eliminating harmful substances, decomposing organic matter, producing bioactive substances (enzymes, vitamins, antimicrobials), which favors the development of plants, because many of the substances produced are phytonutrients, replacing agrochemicals and synthetic fertilizers, improving the quality of the soil by introducing a balanced microflora composed of beneficial microorganisms.