Lexikon

bioleaching is a type of leaching where the extraction of metal from solid minerals into a solution is facilitated by the metabolism of certain microbes - bioleaching microbes. Bioleaching is a process described as "the use of microorganisms to transform elements so that the elements can be extracted from a material when water is filtered trough it".

Source: BioMineWiki: http://wiki.biomine.skelleftea.se/wiki/index.php/Bioleaching

biological pest control in the organic agriculture is mainly against arthropods (e.g. insects, mites) and nematodes, as well as fungi and bacteria.

Insect pests are a common problem, and insecticides, both non-organic and organic, are controversial due to their environmental and health effects. One way to manage insects is to ignore them and focus on plant health, since plants can survive the loss of about a third of leaf area before suffering severe growth consequences.

To avoid using insecticides, one can select naturally resistant plants, put bags around the plants, remove dying material such as leaves, fruit, and diseased plants, cover plants with a solid barrier ("row cover"), wash them, encourage and release beneficial organisms and beneficial insects, plant companion plants and polycultures, install traps such as sticky cards (which can also be used to assess insect prevalence), and season extension. Biological pest control uses natural predators. Recommended beneficial insects include minute pirate bugs, big-eyed bugs, and to a lesser extent ladybugs (which tend to fly away), all of which eat a wide range of pests. Lacewings are also effective, but tend to fly away. Praying mantis tend to move more slowly and eat less heavily. Parasitoid wasps tend to be effective for their selected prey, but like all small insects can be less effective outdoors because the wind controls their movement. Predatory mites are effective for controlling other mites.

Several pesticides approved for organic use, such as spinosad and neem, have been called green pesticides. The main organic insecticides used in the US are Bt (a bacterial toxin) and pyrethrum. Surveys have found that fewer than 10% of organic farmers use these pesticides regularly. Nicotine sulfate may also be used although it is extremely toxic, but breaks down quickly. Less toxic but still effective organic insecticides include neem, spinosad, soaps, garlic, citrus oil, capsaicin (repellent), Bacillus popillae, Beauvaria bassiana, and boric acid. Pesticides should be rotated to minimize pest resistance.

The first disease control strategy involves cleaning the area by removing diseased and dying plants and ensure that the plants are healthy by maintaining water and fertilization.

Compost tea can be effective, but there is concern over whether these are ineffective or even harmful when made incorrectly.

Polyculture and crop rotation reduce the ability of disease to spread. Disease-resistant cultivars can be purchased.

Organic fungicides include the bacteria Bacillus subtilis, Bacillus pumilus, and Trichoderma harzianum which are mainly effective for diseases affecting roots.

Bordeaux mixture contains copper, which can be used as an organic fungicide in various forms. Sulfur is effective against fungus as well as some insects.Lime sulfur is also available, but can damage plants if used incorrectly. Potassium and sodium bicarbonate are also effective against fungus.

Agricultural Research Service scientists have found that caprylic acid, a naturally-occurring fatty acid in milk and coconuts, as well as other natural plant extracts have antimicrobial characteristics that can help.

Source: http://en.wikipedia.org/wiki/Organic_farming

the transfer of substances from the environment to microorganisms, plants, animals, and humans.

biological methods of wastewater treatment aim the biodegradation of the organic and inorganic pollutants in the waste water or the elimination ot these by other biological processes. The biodegradable organic material content of the waste waters is expressed as BOD (Biological Oxigene Demand) which is too high to let the waste-water into living surface waters. That is why we can say, that the aim of biological waste-water treatment is to reduce the BOD content in the waste-waters before their discharge into surface waters. Wastewaters enter the treatment plant with a BOD higher than 200 mg/L, but primary settling has already reduced it to about 150 mg/L by the time it enters the biological component of the technology. It needs to exit with a BOD content no higher than about 20−30 mg/L, so that after dilution in the nearby receiving water body (river, lake), the BOD is less than 2−3 mg/L.

Main principle of biological waste-water treatment is that bacterial cells use the organic material present in the wastewater as substrates for energy production (respiration, mineralisation) accompanied with CO₂ and NH₃ production. Part of the organic and inorganic constituents of the waste-water is used for the biosynthesis of the same microbes; through their metabolism, the organic material is transformed into cellular mass, which is no longer in solution but can be precipitated at the bottom of a settling tank or retained as slime on solid surfaces or vegetation in the system. The outflow of water becomes much clearer than it was, when entered.

The bioengineer ensures the optimal conditionss for the microorganisms to be able to work most efficiently. A key factor is the operation of an aerobic biological system is an adequate supply of oxygen. Indeed, cells need not only organic material as food but also oxygen to breathe. Without an adequate supply of oxygen, the biological degradation of the waste is slowed down, thereby requiring a longer residency time of the water in the treatment technology.

Biological treatment, is also called secondary waste-water treatment is designed to substantially degrade the biologically degradable or modifiable content of the sewage which are derived from human waste, food waste, soaps and detergent, in some cases industrial wastes. The majority of municipal plants treat the settled sewage liquor using aerobic biological processes. The bacteria and protozoa consume biodegradable soluble organic contaminants (e.g. sugars, fats, organic short-chain carbon molecules, etc.) and bind much of the less soluble fractions into floc. Flocs consists of living and dead microbes, slime and sorbed, non.degradable pollutants and waste material. The flocs can be sedimented or otherwise separated from the water phase. Some pollutants are concentrated in the waste-water sludge; part of them are able to be slowly degraded, but an other part is persistent (metals, persistent organic substances). These persistent contaminants in waste-water sludges makes the unlimited utilisation of the sludge impossibel.

Biological waste-water treatment systems are classified as fixed-film or suspended-growth systems. Fixed-film or attached growth systems include trickling filters and rotating biological contactors, where the biomass grows on media and the sewage passes over its surface. Suspended-growth systems include activated sludge, where the biomass is mixed with the sewage and can be operated in a smaller space than fixed-film systems that treat the same amount of water. However, fixed-film systems are more able to cope with drastic changes in the amount of biological material and can provide higher removal rates for organic material and suspended solids than suspended growth systems (Wikipedia).

The most well-known biologica waste-water treatment technologies are the following:
- Activated sludge treatmen
- Surface-aerated basins (Lagoons)
- Filter beds (oxidizing beds)
- Soil Bio-Technology
- Biological aerated filters
- Rotating biological contactors
- Membrane bioreactors
- Secondary sedimentation
- Lagooning
- Constructed wetlands
- Nitrogen removal
- Phosphorus removal

Technologies for the treatment of the waste-water sludge
- Anaerobic digestion
- Aerobic digestion
- Composting
- Incineration
- Sludge disposal

living organisms contribute to the weathering process in many ways.

Trees put down roots through joints or cracks in the rock in order to find moisture. As the tree grows, the roots gradually prize the rock apart.

Even the tiniest bacteria, algae and lichens produce chemicals that help break down the rock on which they live, so they can get the nutrients they need.

Many animals, such as these Piddock shells, bore into rocks for protection either by scraping away the grains or secreting acid to dissolve the rock.
Source: http://www.geolsoc.org.uk/gsl/education/resources/rockcycle/page3568.html

environmental microbiology is the study of the composition and physiology of microbial communities in the environment, their role and function. The environmental compartments, such as soil, water, air and sediments are habitatas of plant and animals as well as microorganisms.

An average gram of soil contains approximately one billion (1,000,000,000) microbes representing probably several thousand species. Microorganisms have special impact on the whole biosphere, on the element-cycles, organic matter degradation (decomposers) and reuse (nutrient recycling), they are the backbone of ecosystems of the zones where light cannot approach. Microbes have a special role in biogeochemical cycles. Microbes, especially bacteria, are of great importance and influence on the whole ecosystem.

Microorganisms are used for in-situ microbial biodegradation or bioremediation of domestic, agricultural and industrial wastes and subsurface pollution in soils, sediments and marine environments. Since most sites typically have multiple pollutant types, the most effective approach to microbial biodegradation is to use a mixture of bacterial species and strains, each specific to the biodegradation of one or more types of contaminants. It is vital to monitor the composition of the indigenous and added bacteria in order to evaluate the activity level and to permit modifications of the nutrients and other conditions for optimizing the bioremediation process.

The most important events of the development of environmetal microbiology:

1887 Sergei Winogradsky studies Beggiatoa and establishes the concept of autotrophy.

1888 Martinus Beijerinck develops the technique of enrichment culture.

1891 Winogradsky discovers the organisms responsible for nitrification is soil, which is of great importance in agriculture because nitrogen is a limiting nutrient in the soil.

1904 Martinus Beijerinck obtains the first pure culture of sulfur-oxidizing bacterium, Thiobacillus denitrificans.

1904 Cornelius Johan Koning suggests that fungi are critical for the decomposition of organic matter.

1909 Sigurd Orla-Jensen proposes the use of physiological characteristics for the classification of bacteria. He later publishes a monograph on lactic acid bacteria that establishes the criteria for assignment.

1920 The Society of American Bacteriologists presents a report on the characterization and classification of bacterial types that becomes the basis for Bergey's manual in 1923.

1961 Brian McCarthy and E. T. Bolton describe a method to compare genetic material from different species using hybridization. Using this technique it is possible to quantitatively compare the relatedness of the two species.

1965 Emile Zuckerkandl and Linus Pauling publish "Molecules as documents of evolutionary history", making a compelling case for the use of molecular sequences of biological molecules to determine evolutionary relationships.

1969 Don Brenner and colleagues establish a more reliable basis for the classification of clinical isolates among members of the Enterobacteriaceae. They use nucleic acid reassociation, where DNA of one organism is allowed to hybridize with another organism. This technique is used to help define a species.

1977 Carl Woese uses ribosomal RNA analysis to identify a third form of life, the Archaea, whose genetic makeup is distinct from but related to both Bacteria and Eucarya.

1977 Holger Jannasch discovers abundant life at the bottom of the ocean near deep sea hydrothermal vents. The entire system is dependent upon sulfur oxidizing microorganisms. Light and photosynthesis do not drive the process.

1982 Karl Stetter isolates hydrothermophilic microbes (Archaea) that can grow at 105°C. The discovery redefines the upper temperature at which life can exist.

1994 Gary Olsen, Carl Woese and Ross Overbeek summarize the state of phylogeny in prokaryotes. This causes scientists to rethink the classification of life and emphasizes the importance of microbes.

Source:

http://www.microbiologytext.com/index.php?module=book&func=displayarticl...

geobiology is a science that combines geology and biology to study the interactions of organisms with their environment: the interactions of the biosphere with the lithosphere, or with the athmosphere.

microbiology is the study of microorganisms, which are unicellular or cell-cluster microscopic organisms. This includes eukaryotes such as fungi and protists, and prokaryotes. Viruses, though not strictly classed as living organisms, are also studied by microbiology. Microbiology refers to the study of life and organisms that are too small to be seen with the naked eye.

Microbiology typically includes the study of the immune system, or Immunology. Generally, immune systems interact with pathogenic microbes; these two disciplines often intersect which is why many colleges offer a paired degree such as "Microbiology and Immunology".

Microbiology is a broad term which includes virology, mycology, parasitology, bacteriology and other branches. A microbiologist is a specialist in microbiology and these other topics.

Microbiology is researched actively, and the field is advancing continually. It is estimated only about one percent of all of the microbe species on Earth have been studied.^[3] Although microbes were directly observed over three hundred years ago, the field of microbiology can be said to be in its infancy relative to older biological disciplines such as zoology and botany.