In bacteria

There are two convenient forms of genetic material, that can be used as vehicles for introducing the new gene into the bacterium a small circular DNA piece, called a plasmid, or a virus that grows in bacteria. The techniques described below apply to both plasmids and viruses. 

Human insulin was the first animal protein to be made in bacteria in a sequence identical to the human pancreatic peptide. Expression of separate insulin A and B chains were achieved in Echerichia coli K-12 using genes for the insulin A and B chains synthesized and cloned in frame with the... 

Nucleic acid contents of SCP products, which range up to 16% in bacteria and 6—11% in yeasts, must be reduced by processing so that intakes are less than 2 g/d to prevent kidney stone formation or gout. Adverse skin and gastrointestinal reactions have also been encountered as a result of human consumption of some SCP products (87). 

After a desired clone is obtained and mapped with restriction enzymes, further analysis usually depends on the deterrnination of its nucleotide sequence. The nucleotide sequence of a new gene often provides clues to its function and the stmcture of the gene product. Additionally, the DNA sequence of a gene provides a guidepost for further manipulation of the sequence, for example, lea ding to the production of a recombinant protein in bacteria. 

Replication of the Recombinant DNA. In bacteria, repHcation of the recombinant DNA is provided by origin sequences, derived usually... 

Luminol chemiluminescence has also been recommended for measuring bacteria populations (304,305). The luminol—hydrogen peroxide reaction is catalyzed by the iron porphyrins contained in bacteria, and the light intensity is proportional to the bacterial concentration. The method is rapid, especially compared to the two-day period required by the microbiological plate-count method, and it correlates weU with the latter when used to determine bacteria... 

The pathways for thiamine biosynthesis have been elucidated only partiy. Thiamine pyrophosphate is made universally from the precursors 4-amino-5-hydroxymethyl-2-methylpytimidinepyrophosphate [841-01-0] (47) and 4-methyl-5-(2-hydroxyethyl)thiazolephosphate [3269-79-2] (48), but there appear to be different pathways ia the eadier steps. In bacteria, the early steps of the pyrimidine biosynthesis are same as those of purine nucleotide biosynthesis, 5-Aminoimidazole ribotide [41535-66-4] (AIR) (49) appears to be the sole and last common iatermediate ultimately the elements are suppHed by glycine, formate, and ribose. AIR is rearranged in a complex manner to the pyrimidine by an as-yet undetermined mechanism. In yeasts, the pathway to the pyrimidine is less well understood and maybe different (74—83) (Fig. 9). 

Several promising antibacterial compounds are available and may be considered for use in U.S. aquaculture. In addition to sarafloxacin, other quinolones, flumequine and oxolinic acid, are already registered in Europe. However, resistance to both of these compounds developed in bacteria in just a few years (20). Enrofloxacin, [95106-60-6], C22H22FN2O2, a quinolone product of Bayer A.G. (Germany), is also a candidate for aquaculture registration in Europe and may be considered for registration in the United States. 

Many proteins that switch off or on gene expression in bacteria are dimeric molecules, and the DNA sequences that they specifically recognize are palindromic at their ends. The twofold symmetry of the protein is therefore matched by twofold symmetry at the ends of the recognition sequence. 

Norris, J.R., Schiffer, M. Photosynthetic reaction centers in bacteria. Chem. Eng. News 68(31) 22-37, 1990. 

Autotrophy A unique form of metabolism foimd only in bacteria. Inorganic compounds (e.g., NH3, N02-, S2, and Fe2+) are oxidized directly (without using sunlight) to yield energy. This metabolic mode also requires energy for C02 reduction, like photosynthesis, but no lipid-mediated processes are involved. This metabolic mode has also been called chemotrophy, chemoautotrophy, or chemolithotrophy. 

Bacterial Photosynthesis A light-dependent, anaerobic mode of metabolism. Carbon dioxide is reduced to glucose, which is used for both biosynthesis and energy production. Depending on the hydrogen source used to reduce COj, both photolithotrophic and photoorganotrophic reactions exist in bacteria. 

Binary fission- Division of one cell into two cells by the formation of a septum. It is the most common form of cell division in bacteria. 

The nutritional requirements of Eseherkhia eoli cells are far simpler than those of humans, yet the macromolecnles found in bacteria are about as complex as those of animals. Since bacteria can make all their essential biomolecnles while subsisting on a simpler diet, do yon think bacteria may have more biosynthetic capacity and hence more metabolic complexity than animals Organize your thoughts on this question, pro and con, into a rational argument. 

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