Any news about the microbes

at the Lascaux Scientific Council ?
 


  Scolecobasidium
Scolecobasidium
 
ANALYSIS OF THE PRESENTATION, MADE AT THE SCIENTIFIC COUNCIL IN THE PRESENCE OF M. GOLDBERG, OF THE FINAL REPORTS ON THE RESEARCH PROGRAMS "MICROCLIMATE-MICROBIOLOGY" AND "MICROBIAL ECOLOGY"

Following the invitation he received from Professor Yves Coppens, Chairman of the Lascaux Scientific Council (see our note entitled "
News from Lascaux: a translucid or transparent scientific council ?"), the LIST spokesman Michel Goldberg attended the session of the Lascaux Scientific Council which took place on December 14, 2001 between 10.30 AM and 1 PM. According to Y. Coppens, this session was supposed to be devoted to the presentation of the reports of the Council's study groups. The report of the "Subterranean climate - Modelization" group will be anayzed in a note that will be published soon (see "Should the "Lascaux Simulator" be improved?"). Here, we shall analyze and comment the report dealing with the two research programs conducted these last years on the microbiology of Lascaux.

Yves Coppens asked René Bally, one of the microbiologists of the scientific council, to report on the conclusions of the studies conducted within the «Microclimate-microbiology» and «Microbial Ecology» programs. R. Bally indicated that these two studies had been made by the LRMH and the C. Alabouvette teams for the former, and by C. Saiz-Jimenez and C. Alabouvette for the latter.  He reported the following :

About the first study :
-    it aimed at establishing a correlation along time between climatic changes in the cavity and the evolution of the microorganisms.
-   some variability of the climatic parameters was observed, but no correlation with the evolution of the microbial populations could be found.
-  however, this study provided indications on what is feasible (what was found feasible was not explicited…).

About the second study :
-   it was focussed on the black spots and included a characterization of the microbial populations through analysis of their DNAs, RNAs and lipids, as well as a characterization of the melanins present in the black spots. It aimed at correlating the composition of the microbial population with the presence of melanin.
-  The specie Ochroconis/Scolecobasidium was detected frequently. Though it was not the dominant species, it is thought to play an important role in melanin formation.
-   the microbiological study was said to have been conducted in a modern manner
-    the study was said to « open on new tracks » and to suggest the probable role of Collembolae (a small arthropode) in the disappearance of the black spots but also in the dissemination of fungi.

The whole presentation of the «final reports» lasted about five minutes. This short presentation did not enable M. Goldberg to get the faintest piece of scientific data, nor any indication on the methods used in the study. Therefore, M. Goldberg had to rely entirely on their evaluation by the microbiologists of the Scientific Council, which appeared to have been made during an earlier session.

After R. Bally’s presentation, Y. Coppens asked M. Goldberg if he had any questions and comments. M. Goldberg replied that the very short report he heard contained no scientific or technical information, and that he could by no means either support or criticize the conclusions on this basis. He repeated the LIST's request that the final reports should be made public. He nevertheless made one comment about the finality of the first program: because it was conducted during the last years of the 2000-2010 period, at a time when the large climatic perturbations introduced during the first part of the decade were no longer present, there were no important climatic variations in the cave. Therefore one could not expect drastic climate-induced changes in the evolution of the microbial populations, rendering the observation of « correlations » highly unlikely. Furthermore, since it is not conceivable to introduce significant climatic perturbations in the cavity for the sake of experimentation (for fear of new microbial outbursts), there seems to be no prospect for  future studies along this line. M. Goldberg pointed out that the single period when such correlations might have been observed was that when outbursts of fungi took place. He therefore insisted again on the importance of  having access to the climatic parameters of the cave recorded during the years of acute crisis (2000-2007) so as to try and find correlations between the temperature, humidity, CO2, … and the fungal growth.

J.-M. Geneste expressed the opinion that this can not be done because there were no biological studies conducted during that period. M. Goldberg replied that though no knowledge of the microbial species present at that time is indeed available, this does not preclude looking at when and where the fungi started growing, as the visual observations of their presence and state must have been recorded in the archives of the cave. J.-J. Delannoy pointed out that there are so many parameters involved in controling the microbial growth that it is hopeless to try and find a simple correlation with one or two parameters. This view is not shared by the LIST as, during the period of acute crisis, the parameters of "external" origin (infiltrations, natural influx of nutrients, evolution of the outer climate, ...) did not undergo abnormal perturbations, as opposed to "internal" parameters that were affected by various human interventions. Furthermore,
«better» is sometimes the ennemy of «good», and it seems to us that investigating a limited number of parameters in relation with fungal growth - even with the risk of not finding any correlation - is preferable to no investigation at all, which implies being certain not to discover anything. Knowing that parameters as crucial for fungi as temperature and humidity had been recorded all along the crisis, it would be a shame not to investigate a possible correlation between them and fungal growth. Though there is no guarantee that this investigation would lead to any conclusion, one should not miss the opportunity of getting such a crucial piece of information if it is indeed contained in the recorded data.

Y. Coppens confirmed that the fungal specie that was supposed to be responsible for the black spots was not the single one involved, but J.-J. Delannoy insisted that «abundance» does not mean «activity». This short discussion left me with the impression that, in the eyes of the scientific council, the question of which specie(s) is (are) responsible for the formation of melanin is still open.

This was the end of the discussion about the microbiological studies. On the basis of the information disclosed, it left M. Goldberg with the impression that neither of the two programs has led to any solid conclusion regarding the conservation of the cave and more particularly the control of the microbial populations. No prospect for future interventions in case of a new microbial outbreak (biocides, irradiation, …) was discussed during this session. No progress seems to have been made in understanding the correlations between the microclimate and the microbiology of the cave. No suggestion has been made as to how to get rid of the melanin.

To conclude, the overall impression left to M. Goldberg, which is shared by the LIST, is that the two research programs have not led to any progress that might provide
at near- or medium-term any application of significant interest for the preservation of the cave.

This negative conclusion should however be tempered by remembering that the presentation and discussion which the LIST spokesman was allowed to hear were extremely superficial. Should one hope that the results kept confidential up to now might, when disclosed, modulate the LIST members' pessimism ?








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