Stable enrichment cultures

Some investigations have used metabolically stable enrichment cultures that are particle free to study biotransformation. These are preferable to the use of sediment slurries even thongh these may be environmentally realistic, and there are several important reasons  

Particularly for anaerobes, however, it is often difficnlt to obtain pure cultures, and sediment or sludge slurries have frequently been used. Examples of studies that have used stable enrichment 

The extensive use in a series of experiments on the anaerobic dechlorination of chlorocatechols (references in Allard et al. 1994). 

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Allard A-S, P-A Hynning, C Lindgren, M Remberger, AH Neilson (1991) Dechlorination of chlorocatechols by stable enrichment cultures of anaerobic bacteria. Appl Environ Microbiol 57 7784. 

Allard, A-S., Hynning, P-A., Remberger, M. Neilson, A. H. (1992). Role of sulfate concentration in dechlorination of 3,4,5-trichlorocatechol by stable enrichment cultures grown with coumarin and flavanone glycones and aglycones. Applied and Environmental Microbiology, 58, 961-8. 

Stable enrichment cultures which have been obtained after successive transfer over extended periods of time and in which organic matter from the sludge or sediment has been removed by dilution. 

Metabolically stable enrichment cultures reduced the aldehyde group and debrominated 5-bromovanillin to 4-methylcatechol, and debrominated 3-bromo-4-hydroxybenzaldehyde to 4-hydroxyben-zoate (Neilson et al. 1988a). 

Davidova lA, LM Gieg, M Nanny, KG Kropp, JM Suflita (2005) Stable isotopic studies on -alkane metabolism by a sulfate-reducing bacterial enrichment culture. Appl Environ Microbiol. 71 8174-8182. 

Chin K., Lukow T., Stubner S., and Comad R. (1999b) Structure and function of the methanogenic archaeal community in stable cellulose-degrading enrichment cultures at two different temperatures (15 and 30 °C). FEMS Microbiol. Ecol. 30, 313-326. 

Neilson, A.H., A.-S. Allard, P.-A. Hynning, and M. Remberger. 1988. Transformations of halogenated aromatic aldehydes by metaboliocally stable anaerobic enrichment cultures. Appl. Environ. Microbiol. 54 2226-2236. 

Although the use of metabolically stable mixed cultures enables an acceptable degree of repeatability to be attained, the use of suspensions or slurries containing sediment or metabolites from previous additions of enrichment substrates introduces undesirable ambiguity in the interpretaton of analytical results. This has been discussed more fully in Section 5.3.1. Inevitably, however, most examples of dechlorination depend on the results of studies with mixed cultures. There are several important issues which have emerged from these quite extensive investigations and these merit brief discussion. 

Stable enrichment mixed culture CO2+NH3 Atrazine used as sole N source 69... 

The method I have developed for enriching with stable isotopes is a pot culture technique. Seeds are germinated in Perlite and... 

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