Genetic Fingerprint unmasks Microbial Vandals

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Genetic Fingerprint unmasks Microbial Vandals

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Press Release by: PR & D - Public Relations for Research &

Development

Published on openPR 01-16-2006 11:52 am - CET

PR Agency: PR & D - Public Relations for Research & Development

(openPR) - For the first time DNA analysis can identify paper-

degrading microorganisms. This is made possible by a molecular

process developed for fungal infected documents at the University of

Vienna with support from the Austrian Science Fund FWF. Fungal

species can now be clearly identified by means of a DNA region known

as ITS1, making it easier to choose effective countermeasures for

conserving historic documents.

It is generally easy enough to say how the ravages of time take

their toll on historically valuable papers. Given the right

conditions, microorganisms such as fungi can colonise a document and

gradually degrade it. However conventional methods for the accurate

identification of these fungi are elaborate and imprecise. They

require a relatively large amount of sampling material as well as

the propagation and subsequent microscopic identification of the

fungal sample - a lengthy and error-prone, process. A team led by

Dr. Guadalupe Pinar at the University of Vienna Department of

Medicinal Chemistry has now developed a process for quickly and

unequivocally classifying fungal species on the basis of their DNA.

Multiple Mutations

Dr. Pinar has taken advantage of a special characteristic of the

genetic material of many fungal species - a DNA region known as ITS1

which shows enormous differences in the sequencing of DNA base pairs

from one strain to another. Outlining the source of these

distinguishing features, Dr. Pinar said: " The ITS1 region is often

subject to spontaneous mutations. These are harmless as this DNA

region doesn't have any recognisable function in the fungal genome

and plays no direct part in the survivability of a fungal species.

But the mutations result in each fungal species' having its own

typical ITS1 region and therefore a very unmistakable fingerprint. "

Large amounts of DNA are required to analyse these sequence

differences in molecular biological relationships. They could

theoretically be obtained by using large amounts of the source

material - but that is not an option with historic documents.

The researchers have now used state-of-the-art methods to clone

sufficient quantities of the DNA needed. Astrid sen, a

certified biologist and partner of Dr. Pinar's team, explained: " We

are using the polymerase chain reaction, a highly efficient process

for cloning individual DNA regions. It allows us to produce large

amounts of ITS1 fragments with a high degree of purity, even when

only very small amounts of fungal material are available for the DNA

extraction. This makes it possible to give maximum care to infected

documents. "

Breaking the Mould

Once sufficient ITS1 fragments have been cloned the actual DNA

analysis can be performed. In a technique known as denaturing

gradient gel electrophoresis, the ITS1 fragments are applied to a

gel which is subjected to an electrical charge. The ITS1 samples in

this field of tension cover different distances depending on the

mutations, so each distance is characteristic of a given fungal

species. An exchange of even one base pair results in differences

which allow the exact fungal species to be identified.

The new method has a further advantage over conventional techniques -

even dead fungi can be used as source material. sen

commented: " Fungi become inactive on paper after about 20 years, but

the source material for our methods, the DNA, can be isolated from

such material as well. This means that samples on which the fungi

are inactive but the degradation process is still ongoing can also

be investigated using our methods. This is where conventional

techniques fall down, as they rely on culturing viable fungi. "

The findings from this Austrian Science Fund FWF backed project will

now make it possible to develop restoration and conservation

measures that are tailored to each type of fungus. This will be

carried out in cooperation with the Istituto Centrale per la

Patologia del Libro in Rome, which is also providing the historical

samples. The Austrian breakthrough will help preserve cultural

treasures for future generations.

Image and text will be available online from Monday, 16th January

2006, 09.00 a.m. MEZ onwards: http://www.fwf.ac.at/en/press/pv200601-

en.html

Scientific Contact:

Dipl.-Biol. Astrid sen

University of Vienna

Dept. for Medicinal Chemistry

Althanstraße 14

A-1090 Vienna

T +43 / 4277 / 55116

E astrid.michaelsen@...

Austrian Science Fund FWF:

Mag. Stefan Bernhardt

Weyringergasse 35

A-1040 Vienna, Austria

T +43 / 1 / 505 67 40 - 36

E bernhardt@...

Copy Editing & Distribution:

PR & D - Public Relations for Research & Development

Campus Vienna Biocenter 2

A-1030 Vienna, Austria

T +43 / 1 / 505 70 44

E contact@...

Vienna, 16th January 2006

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