# Biological Risk for Hypogea: Shared Data from
## 4 Discussion  
### Biodeteriogenic Taxa, Phenomenology of Alteration and Biodeteriogenic Processes  
As shown in Tables 1 and 2, in both Italian and Korean sites, a great number of bacterial and fungal species were found in the analysed tombs. The influence of different bioclimatic conditions, such as of the use of different traditional materials (stone, mortar, brick and pigment) explain the significant number of taxa involved. In Italian sites, hundreds of bacterial species (mainly Actinobacteria, but also Firmicutes (Bacilaceae family) and Alphaproteobacteria) and fungi (principally Sordariomycetes and Eurotiomycetes) were detected by molecular methods [39; 40; 42; 48]. In Korean sites, _Actinomycetes_ and _Bacillus_ sp., which seem to have entered the tomb via the soil were the dominant bacteria [56]. Fungal species of different genera (_Aspergillus_, _Cladosporium_, _Doratomyces_, _Engyodortium_, _Fusarium_, _Geomyces_) were also widespread in the air and on the walls of the various tombs [85]. _Geomyces pannorum_ and _Fusarium solani_ were also identified, and the latter has also been described on the Lascaux cave paintings in France as well as in the Kitora Tomb and Takamatsuzuka Tomb in Japan [104; 19]. The presence of some fungal species (e.g., _A. niger and A. flavus_) can also be dangerous to humans due to their production of mycotoxin and allergens [104]. A peculiar situation occurred in the case of burial remains inside the tombs, which determined a specific selection of microbial colonisation [17]. New studies on old Chinese tombs confirmed the important role of bacterial and fungal colonisation in deterioration processes. In particular, bacteria of the genera _Bacillus_, _Massilia_ and _Brevibacillus_ were identified in the bricks and were considered possible contributors to brick weathering [20]. Such sites contain previously unknown species; new bacterial species of (_Paenibacillus tumbu_ sp. nov.) were isolated from the Tomb of the Emperor [PERSON] of the Sui Dynasty [20]. Fungi were also found in great number, the most common genera being _Cordyceps_, _Fusarium_, _Harpolytrium_, _Entericellopsis_, _Volutella_, _Cladosporium_, _Stachybotrys_, _Trichoderma_, _Cochlonema_[105; 106]. Further studies of interesting and unknown fungal species are underway in Etruscan tombs [32]. In both Italian and Korean sites, algae and cyanobacteria were observed only in conditions of high levels of humidity and sufficient lighting. Similar genera were identified, principally being _Apatococcus_, _Chlorella_, _Trebovacia_, _Stichococcus_, _Pseudococcomyxa_, and _Muriella_ for green algae, and _Chroococcus_ and _Leptolynbya_ for cyanobacteria. It is possible that vicariant species most likely occur in both countries though further in-depth taxonomical studies are needed. The development of roots was sometimes a frequent occurrence as study results illustrated at the Italian and Korean sites, even if the importance of such phenomenon seems to vary between the two countries, probably due to the different management procedures of the areas. The maintenance of herbaceous cover and regular cutting can reduce the risk of damage [43], even if data from Tarquinia reported depth penetration from non-wooden plants. Recent studies have addressed root identification utilising molecular tools. Insects, Arthropoda, and slugs were also detected, in both countries, even if they have not been sufficiently investigated. The role that some identified species may have needs to be carefully evaluated via biomolecular analysis, since many species may simply be part of the soil ecosystem, without being responsible for causing damage. On the contrary, other bacterial and fungal species can be more problematic, since their potential growth produces staining and chemical and physical interference with the materials.