Microbiology of healing mud (fango) from Roman Thermae Aquae Iasae Archaeological Site (Varaždinske Toplice, Croatia)

0434605 - BC 2016 RIV US eng J - Journal Article
Mulec, J. - Krištůfek, Václav - Chroňáková, Alica - Oarga, A. - Scharfen, J. - Šestauberová, Martina
Microbiology of healing mud (fango) from Roman Thermae Aquae Iasae Archaeological Site (Varaždinske Toplice, Croatia).
Microbial Ecology. Roč. 69, č. 2 (2015), s. 293-306. ISSN 0095-3628. E-ISSN 1432-184X
Grant - others:Slovenian Research Agency(SI) J6-0152; Slovenian Research Agency(SI) P6-0119; Slovenian Research Agency(SI) L1-5453
Institutional support: RVO:60077344
Keywords : microbiology * healing mud * Roman Thermae Aquae Iasae Archaeological Site * Varaždinske Toplice
Subject RIV: EE - Microbiology, Virology
Impact factor: 3.232, year: 2015

We found well-preserved, rocky artefacts that had been buried in the healing mud (fango) for more than 1,500 years at the Roman archaeological site at Varaždinske Toplice. This Roman pool with fango sediments and artefacts is fed from hot sulphidic springs. The fango exhibited nearly neutral pH, a high level of organic C, an elevated concentration of heavy metals and a high total microbial biomass, greater than 108 cells per gram of dry weight. The dominant microbes, assessed by molecular profiling (denaturing gradient gel electrophoresis), were affiliated with Thiobacillus, Sulfuricurvum, Polaromonas, Bdellovibrio. Polymerase chain reaction screening for microbial functional guilds revealed the presence of sulphur oxidizers and methanogens but no sulphate reducers. The dominance of four Proteobacterial classes (α-, β-, δ- and ε-Proteobacteria) was confirmed by fluorescence in situ hybridisation; Actinobacteria were less abundant. Cultivable bacteria represented up to 23.4 % of the total bacterial counts when cultivation media was enriched with fango. These bacteria represented the genera Acinetobacter, Aeromonas, Arthrobacter, Comamonas, Ewingella, Flavobacterium, Pseudomonas, Rahnella, Staphylococcus. This study showed that the heterogeneous nature of fango at neutral pH created various microniches, which largely supported microbial life based on sulphurdriven, autotrophic denitrification.
Permanent Link: http://hdl.handle.net/11104/0238984