Bacteria phosphorus

Unlike carbon resources, which are largely respired by heterotrophic bacteria, phosphorus is largely retained under most conditions occurring in natural freshwater environments. Major fractions of phosphorus are taken up by heterotrophic bacteria and transported through the base of the food web by bacterivorous micrograzers of... 

When ferric phosphorus is reduced to ferrous phosphorus by iron-reducing bacteria, phosphorus is released. We know that phosphate is occluded in hydrated ferric hydroxide coating. This is released by reduction of ferric iron to ferrous iron. 

One of the most interesting processes for phosphorus removal fi-om wastewaters is the enhanced biological phosphorus removal (EBPR). This process is based on the capacity of polyphosphate accumulating microorganisms (Poly-P bacteria) to store inside the cells large amounts of phosphorus, when submitted to alternation of anaerobiosis and aerobiosis periods. In these bacteria, phosphorus and carbon metabolisms are closely... 

Water pollutants can also include excessive amounts of heavy metals, radioactive isotopes, faecal coliform bacteria, phosphorus, nitrogen, sodium and other useful (even necessary) elements as well as certain pathogenic bacteria and viruses (Botkin and Keller, 1998). 

The presence of active sulphate-reducing bacteria usually results in graphitic corrosion and this has led to a useful method of diagnosing this cause of corrosion. The leaching out of iron from the graphitic residue which is responsible for the characteristic appearance of this type of corrosion leads to an enriched carbon, silicon and phosphorus content in the residue as compared with the original content of these elements in the cast iron. Sulphur is usually lost to some extent but when active sulphate-reducing bacteria are present, this loss is offset by the accumulation of ferrous sulphide in the residue with a consequent increase in the sulphur content of the residue out... 

The British Non-Ferrous Metals Research Association carried out two series of tests, the results of which have been given by Gilbert and Gilbert and Porter these are summarised in Table 4.12. In the first series tough pitch copper tubes were exposed at seven sites for periods of up to 10 years. The two most corrosive soils were a wet acid peat (pH 4-2) and a moist acid clay (pH 4-6). In these two soils there was no evidence that the rate of corrosion was decreasing with duration of exposure. In the second series phosphorus-deoxidised copper tube and sheet was exposed at five sites for five years. Severe corrosion occurred only in cinders (pH 7 1). In these tests sulphides were found in the corrosion products on some specimens and the presence of sulphate-reducing bacteria at some sites was proved. It is not clear, however, to what extent the activity of these bacteria is a factor accelerating corrosion of copper. 

The first step in the degradation of phosphate and phosphorothioate esters is hydrolysis, and substantial effort has been directed to all groups. Investigations have also been directed to the use of their degradation products as a source of phosphate for the growth of bacteria, and a wide range of phosphates, dialkylphosphates, and phosphorothioates has therefore been examined as sources of phosphorus (Cook et al. 1978). 

Cook AM, CG Daughton, M Alexander (1978) Phosphorus-containing pesticide breakdown products quantitative utilization as phosphorus sources by bacteria. Appl Environ Microbiol 36 668-672. 

Wanner BL (1994) Molecular genetics of carbon-phosphorus bond cleavage in bacteria. Biodegradation 5 175-184. 

Growth experiments were conducted using bacteria from oil installations with several chemicals normally used in injection water treatment. The studies revealed that some chemicals could be utilized as nitrogen sources, as phosphorus sources, and as carbon sources for the bacteria [1696]. Therefore it is concluded that the growth potential of water treatment additives may be... 

Macro- and micronutrients should be provided as needed. Soils usually contain sufficient levels of micronutrients, but very often there is a lack of nitrogen and phosphorus. The addition of N and P is particularly important during the initial stages of treatment, in order to stimulate the growth of indigenous bacteria. After the initial development of a critical microbial mass, N and P are constantly recycled due to the lysis of dead microbial cells.9... 

The organics contaminants, whose concentration is usually expressed in terms of biochemical oxygen demand (BOD), are utilized as food for the bacteria. Besides oxygen, nutrients (nitrogen and phosphorus) are also needed by the bacteria for its metabolism. The concentrations of oxygen, bacteria, organic contaminants, and nutrients, as well as other factors, have an affect on the biological treatment rate. 

In this treatment process, unit operations such as chemical coagulation, flocculation, and sedimentation followed by filtration, activated carbon, ion exchange, and reverse osmosis are employed to remove significant amounts of nitrogen, phosphorus, heavy metals, organic matters, bacteria, and viruses present in wastewater.2 It is always the last process step in the wastewater treatment plant that finally renders the treated wastewater reusable and disposable into the environment without any adverse effect (Figure 22.1). 

Prior, S. and B. Riemann. 1998. Effects of tributyltin, linear alkylbenzenesulfonates, and nutrients (nitrogen and phosphorus) on nucleoid-containing bacteria. Environ. Toxicol. Chem. 17 1473-1480. 

Bacteria are also able to use a large number of organophosphorus insecticides, alkyl phosphates, phosphonates, and the herbicide Glyphosate as phosphorus sources. 

The inefficiency of microbial heterotrophy does have a side benefit as it enhances nutrient remineralization rates. This serves to increase the availability of inorganic nitrogen and phosphorus for the photoautotrophs. The multiple roles of bacteria in the marine food web were shown in Figure 23.2, with the component of the food web controlled by the algal herbivores depicted on the left side and the microbial loop on the right. The viral shunt acts on both pathways. 

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