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RTD info logoMagazine on European Research N°39 - November 2003   
 Tribology in the 'nano' age
 A dead end in 30 years
 Moulding public opinion – truth and myth
 A new ERA of research

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Title  Biocultural fervour

Doctor of biology and chemical engineering Cesareo Saiz-Jimenez has carved out a cross-disciplinary research field for himself, studying the biological processes at work at historical sites and monuments. The implications of this fascinating work extend much further than simply protecting our cultural heritage.

Cesareo Saiz-Jimenez
Cesareo Saiz-Jimenez
During his medical studies, Cesareo Saiz-Jimenez dreamt about the cinema. Bergman, Antonioni, De Sica, Fellini … A few of life’s twists and turns later, we find him with a penknife scraping the walls of a Roman tomb close to Seville. He has since become a biologist, with a passionate interest in protecting historical monuments.

The adventure began timidly when he was studying soil fertility. A chemist colleague told him of a monastery where the wall paintings were deteriorating, for which no chemical explanation could be found. Cesareo Saiz-Jimenez left his microscope to attend to the sick frescos. Closer examination showed the walls to be colonised by green mould, representing just one element in a complex food chain stretching from bacteria to dust mites. The primary cause proved to be atmospheric pollution. Emissions from neighbouring industrial plants had caused the proliferation of sulphur-metabolising bacteria. For the first time, Cesareo Saiz-Jimenez was studying a micro-organic ecosystem in an architectural context.

La Giralda, Altamira and others
Hearing of the degradation of Seville cathedral’s bell tower – the famous Giralda – Cesareo Saiz-Jimenez immediately climbed on to the scaffolding. Later, when Spain joined the European Union, he was able, with European project funding, to devote himself entirely to protecting our cultural heritage. He discovered that the diversity of historical environments (cities, churches, palaces, caves, underground burial sites) is matched only by the diversity of biological activity (bacteria, mould, lichen, algae, moss, plants). With a team of young researchers recruited for these projects, Cesareo Saiz-Jimenez threw himself into comparative studies in Spain, Italy, Belgium, the Netherlands and Austria.

His most significant intervention was definitely the Altamira cave, with its 16 000 year-old rock paintings. The site, visited by 3 000 tourists a day in the 1970s, was invaded by bacteria. Our researcher was able to demonstrate that these were natural colonists, also found in large quantities even in recently discovered or rarely visited caves. All such bacteria feed on the same organic material present in the seepage water, the limited presence of which inhibits their development. But when the caves are opened up, ventilated, lit and frequented, this self-regulating balance is lost. The walls become covered with green, yellow or white colonies, some of which can degrade the pigment of the paintings. The choice is then one of either closing the caves and re-establishing a low-bacteria ecosystem, or undertaking targeted interventions to destroy the bacteria. ‘We should avoid changing the ecological balance without fully knowing the consequences,’ Cesareo Saiz-Jimenez’ advises. ‘For example, the bacteria at Altamira produce antibiotics which prevent any competition from actually ‘setting up shop’. Remove these bacteria and it is quite possible that other micro-organisms will take over, as happened at Lascaux, where mould appeared following the original treatment. For me, the only safe method is to close the cave. You can always satisfy tourists with reproductions.’

A second lesson: many of the bacteria found in the caves are still unknown to scientists and can represent hugely valuable resources. Those at Altamira, for example, have enabled the development of a new wide-spectrum antibiotic (altamiramycin) which is currently undergoing testing in a German laboratory. ‘At the same time as preserving and protecting our cultural heritage, we are making a fundamental contribution to the knowledge of ecosystems and species. We can also find ourselves confronted with conflicting objectives. Sometimes, historical sites represent very special biotopes, with species not found elsewhere, forcing us to chose between conserving the monument and maintaining biodiversity.

An astounding ‘transfer’: bacteria discovered in the prehistoric Altamira cave have been used to develop the new altramiramycin antibiotic.
An astounding ‘transfer’: bacteria discovered in the prehistoric Altamira cave have been used to develop the new altramiramycin antibiotic.
Cultural heritage vs. traffic
Cathedrals too are full of surprises. Cesareo Saiz-Jimenez has a series of boxes containing large blocks of a black, porous matter. ‘This is the crust of vehicle exhaust deposits that used to cover Seville cathedral. In it we have found bacteria that are capable of breaking down the organic components in the oil. Studying monuments is a real Pandora’s box.’

Sadly, the pollution accumulates faster than these bacteria can break it down, so right now there is no other solution than a very expensive cleaning operation every ten or 20 years – or to limit the traffic, diesel buses in particular. ‘We have measured the level of suspension particles in the air. In the road which passes by the cathedral this can reach 330 000 particles per cm3, as against 80 000 in the proximity of Saint Eustache in Paris, or 20 000 in traffic-free roads (1). These results made headlines in Seville’s local press in March 2002. In a report to the city authorities, the researchers recommend rerouting the traffic. But this measure appears to be unpopular and electric buses are too expensive. Even so, Cesareo Saiz-Jimenez is not ready to give up yet (2).

Impossible task
Research, scientific communications, consulting and making recommendations to the political authorities, managing a team and running various projects leave our scientist little or no time for holidays. ‘I am doing what I most like doing in the world – looking at the Altamira bisons, the Roman mosaics, the necropolises – I am in paradise. My laboratory contains all the beauty of past cultures. And on top of that, society pays me a salary for exercising my passion. The least that I can do is to attempt to be useful to it. Saturdays and Sundays are spent on administration work and, in the summer, our indefatigable researcher is either abroad on scientific missions or hosting students in Seville. ‘I am very strong on exchanges between disciplines and nationalities. We need specialists from every discipline – biologists, chemists, architects and archaeologists. You simply cannot do this sort of work in isolation.’

Whilst he is perhaps the most European of Sevillians, Ceseareo Saiz-Jimenez is undoubtedly the most Sevillian of Europeans (‘it is here that life is at its most beautiful’). He loves the city’s lively and colourful traditions – ‘In April, Seville is one big festival, and I always try to avoid travelling then’ – and its outstanding restaurants. On top of this, he has several archaeological sites in the immediate proximity. At the Roman necropolis at Carmona, he is tracking the biological situation, gathering samples, taking photos and measuring black and brown stains to the nearest millimetre. This is usually followed by a visit to the neighbouring monastery to collect some cookies prepared by the nuns. ‘I just love combining my professional trips with other discoveries – art, gastronomy, music…. The extraordinary attraction of this region – and of Europe in general – lies in its fabulous cultural wealth. We have to do everything possible to preserve it.’

(1) See RDT info no 36, A monumental task

(2) A workshop on Air Pollution and Cultural Heritage will be held in Seville Cathedral from 1 to 3 December 2003 for scientists, traffic experts, politicians and members of cultural associations.

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