Library environmental

It is important to note that no single method of cell lysis or DNA purification will be appropriate for all environmental samples. Therefore, researchers should consult protocols that may apply to their systems of study in order to optimize DNA recovery from novel environmental samples. 

DNA source Cloning vector Average insert size of the library (kb) Ref. 

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BNA. 1998. BNA s Environmental Library on CD Windows (ELCD). States and Territories. Folio Infobase. The Bureau of National Affairs, Inc. 123125th Street, NW. Washington, DC 20037. 

Another promising route was reported in patent and open hterature by both DSM and Diversa [13, 14]. This route employs a 2-deoxy-D-ribose 5-phosphate aldolase (DERA) that catalyzes a tandem aldol addition in which two equivalents of acetaldehyde (AA) are added in sequence to chloroacetaldehyde (CIAA) to produce a lactol derivative that is similar to the 3,5-dihydoxy side chain of synthetic statins (Figure 6.2e). Diversa screened environmental libraries for novel wild-type DERAs and identified an enzyme that was both tolerant to increased substrate concentrations and more active than DERA from E. coli in the target reaction [13]. 

Construction of Environmental Libraries for Functional Screening of Enzyme Activity... 

Fig. 4.1. Strategy to access and to exploit the immense genetic diversity of naturally occurring microbial assemblages by construction and screening of environmental libraries.

DNA libraries and to done directly functional genes from natural samples. The knowledge of sequence information prior to cloning is not required. Another advantage is that existing environmental libraries can be employed for screening of various targets. 

Tab. 4.1. Average insert sizes of plasmid-, cosmid- or BAC-based environmental libraries.

In contrast to the construction of genomic libraries from single organisms, a statistic calculation of the completeness of environmental libraries cannot be done, since the initial number of different microorganisms used for the preparation of the environmental DNA is unknown. 

Tab. 4.2. Examples of activity-based screens of various environmental libraries yielding genes that encode activities relevant for biotechnology.

UNEP, 1996. Groundwater a threatened resource. UNEP Environmental Library, No 15, UNEPNairobi, Kenya. 

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