Bacteria requirements

Bacteria require p-aminobenzoic acid to biosyn thesize folic acid a growth factor Structurally sul fanilamide resembles p-aminobenzoic acid and is mistaken for it by the bacteria Folic acid biosynthesis IS inhibited and bacterial growth is slowed suffi ciently to allow the body s natural defenses to effect a cure Because animals do not biosynthesize folic acid but obtain it in their food sulfanilamide halts the growth of bacteria without harm to the host... 

Nitrobacter, an aerobic bacterium, can materially depress pH by oxidizing nitrite (NO2 ) to nitrate (NOa ), in effect producing nitric acid. Acidity may increase until pH is between 3 and 5. Such bacteria require high concentrations of oxygen and cause problems only in oxygenated systems. 

The most common criticism of all instrumental (chemical) methods for characterizing bacteria is the relatively large number of bacteria required. Typically 100,000 bacteria or more or needed for analysis. Not withstanding that... 

Impaired host defenses, vascular occlusive states, traumatized tissues, or presence of a foreign body greatly decrease the number of bacteria required to cause an SSI. 

Blood of normal subjects was obtained from an antecubital vein, diluted 1 5 with pH 4.5 buffer,2 and autoclaved 30 minutes to convert bound cobalamin into its microbiologically active form serum was treated like blood. This procedure allowed estimation of total vitamin Bi2. For the subsequent inoculation of specimens (a) E. coli as a loopful from nutrient agar suspended in 25 ml of medium, (b) L. leichmannii, an 18-hour culture diluted 1 10 in basal medium, (c) E. gracilis, strain Z, and (d) O. malhamensis are inoculated directly from a 5-day culture grown in liquid maintenance medium. One drop into a culture flask served as inoculum. The bacteria required 18-hours for full growth protozoa, 4-5 days. 

Borrelia burgdorferi (157), appears to constitute a group of microorganisms, which do not, in contrast to the majority of Gram-negative bacteria, require a typical LPS for growth and multiplication. 

For biodegradation to occur, everything that bacteria require for growth and reproduction must be available in the microenvironment in the immediate vicinity of the bacterium. The soil-aquifer system must provide water, attachment medium, a source of carbon, gas exchange, electron acceptor compounds, and nutrients. If any of the required items is not available, bacterial functions will be reduced or cease. 

The importance of bacteria in mediating Mn(II) oxidation in certain environments is evident. But, the mechanisms whereby bacteria oxidize Mn(II) are poorly understood. Some bacteria synthesize proteins or other materials that enhance the rate of Mn(II) oxidation (.52). Other strains of bacteria require oxidized manganese to oxidize Mn(II) (53), suggesting that they may catalyse the oxidation of Mn(II) on the manganese oxide surface. Other bacteria may catalyse the oxidation of Mn(II) on iron oxide surfaces, as iron is associated with manganese deposits on bacteria collected in the eastern subtropical North Pacific (54). 

The formation of sulfa drugs is another excimple of a multistep synthesis. The sulfa drugs cire bactericides, effective c ainst a wide variety of bacteria because they mimic p-aminobenzoic acid (Figure 13-48). Many bacteria require p-aminobenzoic acid, which they cire unable to synthesize, and need to synthesize folic acid. Many types of sulfa drugs exist, and most of them involve the substitution of one of the hydrogen atoms on the -SO2-NH2. Prontosil (Figure 13-49) was the first commercially available sulfa drug. The metabolism of prontosil produced sulfanilamide. 

Mectianism of Action Interferes with synthesis of folic acid that bacteria require for growth by inhibition of para-aminobenzoic acid metabolism. Therapeutic Effect Prevents further bacterial growth. 

Mecfianism of Action Interferes with synthesis ot tolic acid that bacteria require tor growth. Therapeutic Effect Prevents turther bacterial growth. Bacteriostatic. Pharmacokinetics Small amounts maybe absorbed into the cornea. Excreted rapidly in urine. Half-life 7-13hr. 

A pH range of 5.5 to 8.5 and a temperature range of 45 to 110°F is required. The bacteria require at least 10 parts per million (ppm) nitrogen and 5 ppm phosphorus. The optimum bioremediation will occur between 3 and 5 mg/liter dissolved oxygen. Extreme salinity, strong acids, caustics, disinfectants, germicides, and chlorine may limit the activity or kill the bacteria. 

Til. Mode of Action of Sulfa Drugs Some bacteria require p-aminobenzoate in the culture medium for normal growth, and their growth is severely inhibited by the addition of sulfanilamide, one of the earliest sulfa drugs. Moreover, in the presence of this drug, 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR see Fig. 22-33) accumulates in the culture medium. These effects are reversed by addition of excess p-aminobenzoate. 

The Three Steps of Initiation The initiation of polypeptide synthesis in bacteria requires (1) the 30S ribosomal subunit, (2) the mRNA coding for the polypeptide to be made, (3) the initiating fMet-tRNAfMet, (4) a set of three proteins called initiation factors (IF-1, IF-2, and IF-3), (5) GTP, (6) the 50S ribosomal subunit, and (7) Mg2+. Formation of the initiation complex takes place in three steps (Fig. 27-20). 

Synthesis of fatty acids in bacteria requires a small acyl carrier protein (ACP) whose functions are similar to those of CoA. However, it contains pante-... 

The human body contains only about 1.5 mg of cobalt, almost all of it is in the form of cobalamin, vitamin B12. Ruminant animals, such as cattle and sheep, have a relatively high nutritional need for cobalt and in regions with a low soil cobalt content, such as Australia, cobalt deficiency in these animals is a serious problem. This need for cobalt largely reflects the high requirement of the microorganisms of the rumen (paunch) for vitamin B12. All bacteria require vitamin B12 but not all are able to synthesize it. For example, E. coli lacks one enzyme in the biosynthetic... 

Examination is made of a drop of the deposit obtained when the wine is either allowed to stand or centrifuged or, with very turbid wine, a drop of the latter itself may be examined. A magnification of 500 diameters is first used, but detection of the smallest bacteria requires about 1000 diameters. 

For chemotherapeutics to be effective against Gram-negative bacteria requires a balance between hydrophilic and hydrophobic properties. The reason for this is the characteristic construction of the bacterial cell wall, with an outer hydrophilic core, rich in polysaccharides, and a hydrophobic phospholipid bilayer. Only very small and hydrophilic drug molecules up to 600 Da can diffuse through membrane pores [63, 64],... 

Bacteria require a dosage of radiation equivalent to about 10,000 -30,000 microwatt-seconds/square centimeter. This can achieved by using a 254-nanometer wavelength. This wavelength alters the DNA of microbes, causing them to be unable to reproduce, leading to their death. 

The important point to note is that these bacteria require oxygen and a source of reduced sulfur. The end product is sulfuric acid. The problem of septic sewage systems in hot climates starts with growth of anaerobic SRB in the sewage, producing H2S. This gas migrates to the air space at the top of the line, where it is oxidized into sulfuric acid in the water droplets at the crown of the pipe by Thiobacillus. The corrosion problem is due to the combination of the bacterial action that results in dissolution of the alkaline mortar by the acid, followed by corrosion of the ductile iron. (Stott)5... 

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