Nd-YAG laser irradiation damages to Verrucaria nigrescens

Abstract Epilithic and endolithic microorganisms and lichens play an important role in stone biodeterioration. The structural and physiological damage caused by nanosecond pulsed laser of 1064 nm from Nd:YAG laser to Verrucaria nigrescens lichen as well as to endolithic algae and fungi were investigated in the present study. Ultrastructural laser effects on lichen and endolithic microorganisms were study without disturbing the relationship between lichen and lithic substrate by taking lichen-containing rock fragments and processing both together. SEM-BSE, LT-SEM and FM were used to determine cell integrity and ultrastructure, which reflect microorganism viability. Photobiont vitality was determined using a PAM chlorophyll fluorescence technique. The lichen thalli were completely removed by irradiation with 5 ns pulses at a fluence of 2.0 J/cm 2 with no stone damage as showed by micro-Raman spectroscopy. The fungal and algal endolithic cells located below were completely destroyed or presented a high plasmolysis degree resulting from heating their microenvironment. The lichen and endolithic mycobiont near the irradiated zone were also damaged. Algal photosynthetic damage prevents fungal survival and lichen viability. This is the first report of laser removal and inactivation of lichen and lithic microorganisms, and thus provide an environmentally friendly and efficient method to control stone biodeterioration.

[1]  R. Fort,et al.  Characterizing the Microbial Colonization of a Dolostone Quarry: Implications for Stone Biodeterioration and Response to Biocide Treatments , 2011, Microbial Ecology.

[2]  T. Smijs,et al.  Photodynamic Inactivation of the Dermatophyte Trichophyton rubrum¶ , 2003, Photochemistry and photobiology.

[3]  Clifford W. Smith.  The Lichens of Great Britain and Ireland , 2009 .

[4]  K. Borkovich,et al.  Cellular and molecular biology of filamentous fungi , 2010 .

[5]  V. Zafiropulos,et al.  Investigations on cleaning of black crusted sandstone using different UV-pulsed lasers , 2000 .

[6]  S. Pérez-Ortega,et al.  Differential effects of biocide treatments on saxicolous communities: Case study of the Segovia cathedral cloister (Spain) , 2012 .

[7]  C. Ascaso,et al.  Morphological and Chemical Features of Bioweathered Granitic Biotite Induced by Lichen Activity , 1996 .

[8]  A. E. Charola,et al.  Endolithic Microorganisms in the Biodeterioration of the Tower of Belem , 1998 .

[9]  A. Casadevall,et al.  Synthetic Consolidants Attacked by Melanin-Producing Fungi: Case Study of the Biodeterioration of Milan (Italy) Cathedral Marble Treated with Acrylics , 2006, Applied and Environmental Microbiology.

[10]  H. Alakomi,et al.  Weakening Effect of Cell Permeabilizers on Gram-Negative Bacteria Causing Biodeterioration , 2006, Applied and Environmental Microbiology.

[11]  A. Decruz,et al.  Er:YAG Laser Applications on Marble and Limestone Sculptures with Polychrome and Patina Surfaces , 2005 .

[12]  L. Sancho,et al.  In situ comparison of Daily Photosynthetic Activity Patterns of Saxicolous Lichens and Mosses in Sierra de Guadarrama. Central Spain , 1999 .

[13]  J. H. Potgieter,et al.  Micro-structural characterization of black crust and laser cleaning of building stones by micro-Raman and SEM techniques. , 2005, Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy.

[14]  F. Calvet,et al.  Lichenic alteration and mineralization in calcareous monuments of northeastern Spain , 1995 .

[15]  Eric Doehne,et al.  Stone Conservation: An Overview of Current Research , 1998 .

[16]  L. Sancho,et al.  Viability of endolithic micro‐organisms in rocks from the McMurdo Dry Valleys of Antarctica established by confocal and fluorescence microscopy , 2004, Journal of microscopy.

[17]  Teresa Rivas,et al.  Optimization of laser cleaning parameters for the removal of biological black crusts in granites , 2010 .

[18]  Maria Perla Colombini,et al.  Investigation of the Er:YAG Laser at 2.94 μm to Remove Lichens Growing on Stone , 2009 .

[19]  C. Ascaso,et al.  Contributions of in situ microscopy to the current understanding of stone biodeterioration. , 2005, International microbiology : the official journal of the Spanish Society for Microbiology.

[20]  K. Nandakumar,et al.  Impact of Pulsed Nd:YAG Laser Irradiation on the Growth and Mortality of the Biofilm Forming Marine Bacterium Pseudoalteromonas carrageenovora , 2002 .

[21]  K. Nandakumar,et al.  In vitro laser ablation of laboratory developed biofilms using an Nd:YAG laser of 532 nm wavelength , 2004, Biotechnology and bioengineering.

[22]  Paraskevi Pouli,et al.  Short free running Nd:YAG laser to clean different encrustations on Pentelic marble: procedure and evaluation of the effects , 2003 .

[23]  C. Gueidan,et al.  Using a multigene phylogenetic analysis to assess generic delineation and character evolution in Verrucariaceae (Verrucariales, Ascomycota). , 2007, Mycological research.

[24]  Mohamed Oujja,et al.  Practical issues in laser cleaning of stone and painted artefacts: optimisation procedures and side effects , 2012 .

[25]  M. Galun,et al.  “Oil hyphae” of endolithic lichens and their fatty acid composition , 1978, Protoplasma.

[26]  L. Sancho,et al.  Space Flight Effects on Lichen Ultrastructure and Physiology , 2010 .

[27]  J. Rodrigues,et al.  In situ evaluation of the biodeteriorating action of microorganisms and the effects of biocides on carbonate rock of the Jeronimos Monastery (Lisbon) , 2002 .

[28]  Stefano Bertuzzi,et al.  Chlorophyll a fluorescence as a practical tool for checking the effects of biocide treatments on endolithic lichens , 2010 .

[29]  O. Salvadori,et al.  Efficacy of a biocide tested on selected lichens and its effects on their substrata , 2007 .

[30]  C. Ascaso,et al.  Microstructural Characterization of Cyanobacterial Mats from the McMurdo Ice Shelf, Antarctica , 2004, Applied and Environmental Microbiology.

[31]  A. Lewis,et al.  Direct Antifungal Effect of Femtosecond Laser on Trichophyton rubrum Onychomycosis , 2010, Photochemistry and photobiology.

[32]  C. Ascaso,et al.  Application of back‐scattered electron imaging to the study of the lichen‐rock interface , 1994 .

[33]  E. Vural,et al.  The effects of laser irradiation on Trichophyton rubrum growth , 2008, Lasers in Medical Science.

[34]  John F. Asmus,et al.  Lichen removal from Chinese Spirit Path figures of marble , 2000 .

[35]  C. Ascasoa,et al.  Study of the biogenic weathering of calcareous litharenite stones caused by lichen and endolithic microorganisms , 1998 .

[36]  Michael T. Wilson,et al.  Sensitisation of cariogenic bacteria to killing by light from a helium-neon laser. , 1993, Journal of medical microbiology.

[37]  O. Salvadori,et al.  An anatomical investigation of calcicolous endolithic lichens from the Trieste karst (NE Italy) , 1998 .

[38]  Z. Kollia,et al.  Preventing biological activity of Ulocladium sp spores in artifacts using 157-nm laser , 2006 .

[39]  G W Marshall,et al.  Scanning electron microscopic examination of intracanal wall dentin: hand versus laser treatment. , 1993, Scanning microscopy.

[40]  O. Yarden,et al.  The Cell Wall of Filamentous Fungi , 2010 .

[41]  M. Oujja,et al.  Laser cleaning of terracotta decorations of the portal of Palos of the Cathedral of Seville , 2005 .

[42]  C Saiz-Jimenez,et al.  The laser-induced discoloration of stonework; a comparative study on its origins and remedies. , 2008, Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy.

[43]  Martin Cooper,et al.  Laser cleaning in conservation : an introduction , 1998 .

[44]  C. Gaylarde,et al.  Microbial deterioration of stone monuments--an updated overview. , 2009, Advances in applied microbiology.