Culture and Identification

Cultures of samples made in the field using septum culture bottles containing a growing medium can give information on the bacteria present and the degree of contamination. 

The culture bottle technique employs successive dilutions of the field water in the cnlture media. The more dilute the sample bottle that shows bacterial activity, the more contaminated the field water sample. This technique is termed extinction dilution or serial dilntion. With suitable culture media bottles this method can be used for either aerobic bacteria or sulphate-reducing bacteria. 

As a general guide, for aerobic bacteria, counts of less than 10000 per ml are not normally considered significant, counts of 50000-100000 per ml indicate a strong probability of plugging and requirement for treatment. Any positive identification of sulfate-reducing bacteria indicates a problem. 

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He J, KM Ritalakti, MR Aiello, FE Loftier (2003) Complete detoxification of vinyl chloride by an anaerobic enrichment culture and identification of the reductively dechlorinating population as a Dehaloccoides species. Appl Environ Microbiol 69 996-1003. 

Samples of tissue or body fluids may be obtained for laboratory culture and identification so that the clinician s guess can be confirmed and susceptibility of the isolated microorganisms(s) to anti-infective drugs can be assessed. Because laboratory identification and susceptibility... 

Management must modify the culture and develop human factors awareness in the hazard identification teams so that they will be capable of identifying the potential for human error. A good practice is to involve operators in the hazard identification team. 

The identification of bacteria has traditionally required the establishment of a pure culture before any other steps are taken. Pure cultures of bacteria may sometimes be obtained from blood and spinal fluid, which are normally sterile, or from extreme environments like hot springs. However, because there are few such situations in nature, individual bacteria must generally be isolated from other cells and grown for one to five days to obtain pure cultures before identification. Some pathogenic bacteria are obligate intracellular parasites that are difficult or impossible to grow outside their mammalian host cells 37 for these, pure cultures are not feasible. 

Because the time required for growth of pure cultures delays identification, serological and molecular techniques that bypass this step are often employed. These methods often are able to show the presence of target organisms in mixed samples. 

ToF-SIMS Study of Organic Materials in Cultural Heritage Identification and Chemical Imaging... 

Table 1 Experiment 2. Guided isolation and identification of potential allelochemicals from Cladonia foliacea. O, fraction O P, fraction P UA, usnic acid ca, caulonema ch, chloronema sb, side branches. Protonemal system from shoots after 21 days in culture tested against three fractions from C. foliacea thallus and in control Mohr medium. The observations represent means calculated from about 300 protonemata for each species. P. squarrosa is the species least affected, while 7. flavovirens is the most affected by lichen fractions. 

Miller P, Scholin C. Identification and enumeration of cultured and wild Pseudo-nitzschia (Bacillariophyceae) using species-specific LSU rRNA-targeted fluorescent probes and filter-based whole cell hybridization. J Phycol 1998 34 371-382. 

The vast majority of research focused on selenium in biology (primarily in the fields of molecular biology, cell biology, and biochemistry) over the past 20 years has centered on identification and characterization of specific selenoproteins, or proteins that contain selenium in the form of selenocysteine. In addition, studies to determine the unique machinery necessary for incorporation of a nonstandard amino acid (L-selenocysteine) during translation also have been central to our understanding of how cells can utilize this metalloid. This process has been studied in bacterial models (primarily Escherichia colt) and more recently in mammals in vitro cell culture and animal models). In this work, we will review the biosynthesis of selenoproteins in bacterial systems, and only briefly review what is currently known about parallel pathways in mammals, since a comprehensive review in this area has been recently published. Moreover, we summarize the global picture of the nonspecific and specific use of selenium from a broader perspective, one that includes lesser known pathways for selenium utilization into modified nucleosides in tRNA and a labile selenium cofactor. We also review recent research on newly identified mammalian selenoproteins and discuss their role in mammalian cell biology. 

Feung. C. S., Hamilton. R.H., Witham. F.H., and Mumma, R.O. The relative amounts and identification of some 2,4-dichlorophenoxyacetic acid metabolites isolated from soybean cotyledon callus cultures. Plant Physiol., 50 80-86, 1972. 

If the number of suspicious cells in the cytological picture is low, mostly in oligocellular CSF samples, it is possible to multiply malignant or controversial cellular elements using the methods of tissue culture and further identification. 

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