an organism that obtains its energy from the oxidation of inorganic compounds
The difference is the way they obtain energy. Chemotrophs are organisms that obtain energy by the oxidation of electron donors in their environments. These molecules can be organic (chemoorganotrophs) or inorganic (chemolithotrophs). Photoheterotrophs are heterotrophic organisms that use light for energy, but cannot use carbon dioxide as their sole carbon source.
Some prokaryotes, such as thermophiles and chemolithotrophs, obtain energy from hydrothermal vents. Thermophiles can survive and thrive in the extreme temperatures of hydrothermal vents, while chemolithotrophs use inorganic compounds like hydrogen sulfide as a source of energy.
Archaebacteria can be chemoheterotrophs, meaning they obtain their energy by consuming organic matter. Some species of archaebacteria can also be chemolithotrophs, deriving energy from inorganic compounds such as sulfur or hydrogen.
Chemolithotrophs are organisms that derive energy by oxidizing inorganic compounds, such as minerals or chemicals, without needing organic molecules for energy. These organisms use this energy to fuel their metabolic processes and do not rely on organic sources for their energy needs.
Bacteria that use chemicals like sulfur as an energy source are considered chemolithotrophs. They can obtain energy by oxidizing inorganic compounds such as sulfur rather than organic compounds. These bacteria play an important role in various ecosystems, such as hydrothermal vents or sulfur springs, where they contribute to biogeochemical cycling.
Sulfur and sulfate-reducing bacteria use sulfur as terminal electron acceptors and oxidize organic material 1.1) Reduce it to hydrogen sulfide -> Responsible for rotten egg smell 1.2) These organisms essential for sulfur cycle in ecosystem 2) Generally found in mud rich in organic matter and sulfur
The group of microorganisms that has the most extensive bioenergetic enzyme system is falcultative anaerobes. Falcutative anaerobes can work in both the presence and absence of oxygen. They do both cellular respiration and fermentation.
oxidize reduced inorganic chemicals to produce energy 2) Use alternate terminal electron acceptor other than oxygen -> Usually carbon dioxide or sulfur 3) Usually members of the domain Archaea 4) Some anaerobic chemoorganitrophs produce ATP via anaerobic respiration through the oxidation of organic molecules -> Also use terminal electron acceptor other than oxygen -> Sulfur and sulfate are common 5) Other anaerobic chemoorganitrophs produce energy through fermentation -> Produce energy through substrate phosphorylation only
Bacteria are the unicellular prokaryotic microorganisms. Bacteria are smallest in size and are largest in numbers among living organisms. Bacteria were first discovered by a Dutch scientist Anton van Leeuwenhoek in 1670 in rain water, then in pond water and in scraping of his teeths. He consider them as animal cules. They show some plants like characters as presence of rigid cell wall and reproduction by spores. The average size varies in micrometers as smallest one is cocci i.e. from 0.5-3.5 microns and largest is spirillum 15-22 microns. They can be rod like ( E.col, Rhizobium), spherical may be monococcus, dicoccus, streptococcus (in chain), staphylococcus( in an irregular bunch), helical, vibrio, spiral, or filamentus. Some time they are pleomorphic e.g. Acetobacter. They are chemolithotrophs or chemoautotrophs and also heterotrophs. Reproduction is either vegitative or asexual ( by conidia, or endospores). True sexual reproduction and alteration of generation are absent in bacteria, and can be done by conjugation, transformation and transduction. According to six-kingdom classification the bacteria comes under Monera i.e. of prokaryotes. According to the Cavalier-Smith two EMPIRE and eight KINGDOM classification the bacterial Empire contains two kingdoms the Eubacteria and the archaeobacteria
Sulfur is one of the constituents of many proteins, vitamins and hormones. It recycles as in other biogeochemical cycles.The essential steps of the sulfur cycle are:Mineralization of organic sulfur to the inorganic form, hydrogen sulfide: (H2S).Oxidation of sulfide and elemental sulfur (S) and related compounds to sulfate (SO42-).Reduction of sulfate to sulfide.Microbial immobilization of the sulfur compounds and subsequent incorporation into the organic form of sulfur.These are often termed as follows: Assimilative sulfate reduction (see also sulfur assimilation) in which sulfate (SO42-) is reduced to organic sulfhydryl (otherwise known as thiol) groups (R-SH) by plants, fungi and various prokaryotes. The oxidation states of sulfur are +6 in sulfate and -2 in R-SH. Desulfuration in which organic molecules containing sulfur can be desulfurated, producing hydrogen sulfide gas (H2S), oxidation state = -2. Note the similarity to deamination. Oxidation of hydrogen sulfide produces elemental sulfur (So), oxidation state = 0. This reaction is done by the photosynthetic green and purple sulfur bacteria and some chemolithotrophs. Further oxidation of elemental sulfur by sulfur oxidizers produces sulfate. Dissimilative sulfur reduction in which elemental sulfur can be reduced to hydrogen sulfide. Dissimilative sulfate reduction in which sulfate reducers generate hydrogen sulfide from sulfate.Human impact on the sulfur cycle is primarily in the production of sulfur dioxide (SO2) from industry (e.g. burning coal) and the internal combustion engine. Sulfur dioxide can precipitate onto surfaces where it can be oxidized to sulfate in the soil (it is also toxic to some plants), reduced to sulfide in the atmosphere, or oxidized to sulfate in the atmosphere as sulfuric acid, a principal component of acid rain
The name bacteria is from the Greek bacterion ("little stick", i.e. the rod forms).Bacteria are unicellular prokaryotic microorganisms. Bacteria are the smallest in size and largest in number among living organisms. Bacteria were first discovered by Dutch scientist Anton van Leeuwenhoek in 1675 in rain water, then in pond water and in scrapings from his teeth. He considered them animalcules.They show some plant-like characteristics such as the presence of rigid cell walls and reproduction by spores. The average size varies in micrometers as the smallest one is cocci i.e. from 0.5-3.5 microns and largest is spirillum 15-22 microns.They can be rod-like ( E.col, Rhizobium), or spherical, monococcus, dicoccus, streptococcus (in chain), staphylococcus( in an irregular bunch), helical, vibrio, spiral, or filamentus. Sometimes they are pleomorphic e.g. Acetobacter.They may be chemolithotrophs or chemoautotrophs, or heterotrophs.Reproduction is either vegetative or asexual ( by conidia, or endospores). True sexual reproduction and alteration of generation are absent in bacteria, and can be done by conjugation, transformation and transduction.According to six-kingdom classification the bacteria comes under Monera i.e. of prokaryotes. According to the Cavalier-Smith two EMPIRE and eight KINGDOM classification the bacterial Empire contains two kingdoms the Eubacteria and the archaeobacteria.(Biol.) A microscopic single-celled organism having no distinguishable nucleus, belonging to the kingdom Monera. Bacteria have varying shapes, usually taking the form of a jointed rodlike filament, or a small sphere, but also in certain cases having a branched form. Bacteria are destitute of chlorophyll, but in those members of the phylum Cyanophyta (the blue-green algae) other light-absorbing pigments are present. They are the smallest of microscopic organisms which have their own metabolic processes carried on within cell membranes, viruses being smaller but not capable of living freely. The bacteria are very widely diffused in nature, and multiply with marvelous rapidity, both by fission and by spores. Bacteria may require oxygen for their energy-producing metabolism, and these are calledaerobes; or may multiply in the absence of oxygen, these forms being anaerobes. Certain species are active agents in fermentation, while others appear to be the cause of certain infectious diseases. The branch of science with studies bacteria is bacteriology, being a division of microbiology. See Bacillus. [1913 Webster +PJC]