A microorganism, or microbe, is an organism of microscopic size, which may exist in its single-celled form or as a colony of cells.
The rotifers, sometimes called wheel animals or wheel animalcules, make up a phylum of microscopic and near-microscopic pseudocoelomate animals.
Meiobenthos, also called meiofauna, are small benthic invertebrates that live in marine or freshwater environments, or both. The term meiofauna loosely defines a group of organisms by their size—larger than microfauna but smaller than macrofauna—rather than by their taxonomy. This fauna includes both animals that turn into macrofauna later in life, and those small enough to belong to the meiobenthos their entire life. In marine environments there can be thousands of individuals in 10 cubic centimeters of sediment, and counts animals like nematodes, copepods, rotifers, tardigrades and ostracods, but protists like ciliates and foraminifers within the size range of the meiobethos are also often included. In practice, the term usually includes organisms that can pass through a 1 mm mesh but are retained by a 45 μm mesh, though exact dimensions may vary. Whether an organism will pass through a 1 mm mesh also depends upon whether it is alive or dead at the time of sorting.
Fauna is all of the animal life present in a particular region or time. The corresponding terms for plants and fungi are flora and funga, respectively. Flora, fauna, funga and other forms of life are collectively referred to as biota. Zoologists and paleontologists use fauna to refer to a typical collection of animals found in a specific time or place, e.g. the "Sonoran Desert fauna" or the "Burgess Shale fauna". Paleontologists sometimes refer to a sequence of faunal stages, which is a series of rocks all containing similar fossils. The study of animals of a particular region is called faunistics.
Detritivores are heterotrophs that obtain nutrients by consuming detritus. There are many kinds of invertebrates, vertebrates, and plants that carry out coprophagy. By doing so, all these detritivores contribute to decomposition and the nutrient cycles. Detritivores should be distinguished from other decomposers, such as many species of bacteria, fungi and protists, which are unable to ingest discrete lumps of matter. Instead, these other decomposers live by absorbing and metabolizing on a molecular scale. The terms detritivore and decomposer are often used interchangeably, but they describe different organisms. Detritivores are usually arthropods and help in the process of remineralization. Detritivores perform the first stage of remineralization, by fragmenting the dead plant matter, allowing decomposers to perform the second stage of remineralization.
The soil food web is the community of organisms living all or part of their lives in the soil. It describes a complex living system in the soil and how it interacts with the environment, plants, and animals.
The rhizosphere is the narrow region of soil or substrate that is directly influenced by root secretions and associated soil microorganisms known as the root microbiome. Soil pores in the rhizosphere can contain many bacteria and other microorganisms that feed on sloughed-off plant cells, termed rhizodeposition, and the proteins and sugars released by roots, termed root exudates. This symbiosis leads to more complex interactions, influencing plant growth and competition for resources. Much of the nutrient cycling and disease suppression by antibiotics required by plants occurs immediately adjacent to roots due to root exudates and metabolic products of symbiotic and pathogenic communities of microorganisms. The rhizosphere also provides space to produce allelochemicals to control neighbours and relatives.
In biology, detritus is dead particulate organic material, as distinguished from dissolved organic material. Detritus typically includes the bodies or fragments of bodies of dead organisms, and fecal material. Detritus typically hosts communities of microorganisms that colonize and decompose it. In terrestrial ecosystems it is present as leaf litter and other organic matter that is intermixed with soil, which is denominated "soil organic matter". The detritus of aquatic ecosystems is organic substances that is suspended in the water and accumulates in depositions on the floor of the body of water; when this floor is a seabed, such a deposition is denominated "marine snow".
Microecosystems can exist in locations which are precisely defined by critical environmental factors within small or tiny spaces.
Vorticella is a genus of bell-shaped ciliates that have stalks to attach themselves to substrates. The stalks have contractile myonemes, allowing them to pull the cell body against substrates. The formation of the stalk happens after the free-swimming stage.
Soil biology is the study of microbial and faunal activity and ecology in soil. Soil life, soil biota, soil fauna, or edaphon is a collective term that encompasses all organisms that spend a significant portion of their life cycle within a soil profile, or at the soil-litter interface. These organisms include earthworms, nematodes, protozoa, fungi, bacteria, different arthropods, as well as some reptiles, and species of burrowing mammals like gophers, moles and prairie dogs. Soil biology plays a vital role in determining many soil characteristics. The decomposition of organic matter by soil organisms has an immense influence on soil fertility, plant growth, soil structure, and carbon storage. As a relatively new science, much remains unknown about soil biology and its effect on soil ecosystems.
Most organisms involved in water purification originate from the waste, wastewater or water stream itself or arrive as resting spore of some form from the atmosphere. In a very few cases, mostly associated with constructed wetlands, specific organisms are planted to maximise the efficiency of the process.
Protozoa are a polyphyletic group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic debris. Historically, protozoans were regarded as "one-celled animals".
Archaeobiology, the study of the biology of ancient times through archaeological materials, is a subspecialty of archaeology. It can be seen as a blanket term for paleobotany, animal osteology, zooarchaeology, microbiology, and many other sub-disciplines. Specifically, plant and animal remains are also called ecofacts. Sometimes these ecofacts can be left by humans and sometimes they can be naturally occurring. Archaeobiology tends to focus on more recent finds, so the difference between archaeobiology and palaeontology is mainly one of date: archaeobiologists typically work with more recent, non-fossilised material found at archaeological sites. Only very rarely are archaeobiological excavations performed at sites with no sign of human presence.
Plant litter is dead plant material that have fallen to the ground. This detritus or dead organic material and its constituent nutrients are added to the top layer of soil, commonly known as the litter layer or O horizon. Litter is an important factor in ecosystem dynamics, as it is indicative of ecological productivity and may be useful in predicting regional nutrient cycling and soil fertility.
Antarctica is one of the most physically and chemically extreme terrestrial environments to be inhabited by lifeforms. The largest plants are mosses, and the largest animals that do not leave the continent are a few species of insects.
Soil microbiology is the study of microorganisms in soil, their functions, and how they affect soil properties. It is believed that between two and four billion years ago, the first ancient bacteria and microorganisms came about on Earth's oceans. These bacteria could fix nitrogen, in time multiplied, and as a result released oxygen into the atmosphere. This led to more advanced microorganisms, which are important because they affect soil structure and fertility. Soil microorganisms can be classified as bacteria, actinomycetes, fungi, algae and protozoa. Each of these groups has characteristics that define them and their functions in soil.
Soil mesofauna are invertebrates between 0.1mm and 2mm in size, which live in the soil or in a leaf litter layer on the soil surface. Members of this group include nematodes, mites, springtails (collembola), proturans, pauropods, rotifers, earthworms, tardigrades, small spiders, pseudoscorpions, opiliones (harvestmen), enchytraeidae such as potworms, insect larvae, small isopods and myriapods. They play an important part in the carbon cycle and are likely to be adversely affected by climate change.
A phytobiome consists of a plant (phyto) situated in its specific ecological area (biome), including its environment and the associated communities of organisms which inhabit it. These organisms include all macro- and micro-organisms living in, on, or around the plant including bacteria, archaea, fungi, protists, insects, animals, and other plants. The environment includes the soil, air, and climate. Examples of ecological areas are fields, rangelands, forests. Knowledge of the interactions within a phytobiome can be used to create tools for agriculture, crop management, increased health, preservation, productivity, and sustainability of cropping and forest systems.
The branches of microbiology can be classified into pure and applied sciences. Microbiology can be also classified based on taxonomy, in the cases of bacteriology, mycology, protozoology, and phycology. There is considerable overlap between the specific branches of microbiology with each other and with other disciplines, and certain aspects of these branches can extend beyond the traditional scope of microbiology In general the field of microbiology can be divided in the more fundamental branch and the applied microbiology (biotechnology). In the more fundamental field the organisms are studied as the subject itself on a deeper (theoretical) level. Applied microbiology refers to the fields where the micro-organisms are applied in certain processes such as brewing or fermentation. The organisms itself are often not studied as such, but applied to sustain certain processes.
