## 3 Results and Discussion
### Bacterial Community
PKE117 is able to produce a wood weight loss ranging from 8% to 27% in 60 days. The characterization of the degraded wood showed that the lignin structure was degraded more than the cellulose [52]. Other studies demonstrated that several species belonging to the genus _Pseudomonas_ are able to degrade lignin and lignin model compounds, to oxidize carbohydrates and to degrade cellulose via different metabolic pathways [53; 54; 55; 56; 57; 58; 59]. Species belonging to this genus are considered as cosmopolites and no specific relations have been reported with one or more wood species. In the present study, _Pseudomonas_ sp. was identified in silver fir, elm, ash and holm oak samples. [PERSON] et al. [23] reported _Pseudomonas_ spp. from WAW pilings from different sites across Europe. The species were associated with spruce (_Picea abies_ (L.) [PERSON]), fir, Scots pine (_Pinus sylvestris_ L.), oak and poplar (_Populus_ sp.). [PERSON] et al. [25] identified _Pseudomonas_ spp. from pine samples belonging to the wood recovered inside a rostrum in the site of Acqualadroni (Messina, Sicily). [PERSON] et al. [29] identified three _Pseudomonas_ strains from _Quercus robur/petraea_ remains recovered from different sites across Europe. In WAW, the genus _Janthinobacterium_ is reported in association with _Pseudomonas_, in samples coming from sites characterized by limy soil [23; 29]. Some species of the genus are reported from lake sediments, as part of the bacteriplankton of maritime Antarctic lake and from Antarctic snow [60; 61; 62]. In the present study, it was identified only in N88 and N39, respectively silver fir and elm, in association with _Pseudomonas_. [PERSON] and [PERSON] [63] demonstrated that the strain _Janthinobacterium_ sp. AR-129 has cellulolytic activity and is able to produce high thermal stable cellulase. _Flavobacterium_ was identified in all the Naples samples but not in Pisa. The genus is reported as part of the bacterial community of WAW piles coming from two archaeological sites from the Netherlands [23] and it has also been identified in the storage water of lacquerware from the Nanhai No. 1 shipwck (China) [31]. Members of the genus _Flavobacterium_ have a wide distribution, they mostly occur in aquatic ecosystems ranging in salinity from freshwater to seawater, but have also been isolated from soil and sediments [64]. The species _F. akiainviviens_ was isolated from decaying wood of the Hawaiian shrub _Wilkstroemia oahuensis_[65]. The known species belonging to this genus are able to degrade cellulose derivatives but not crystalline cellulose, some strains have proved to be able to lysate algae [64; 66]. _Sphingomonas_ was found in samples N4, N9 and N39. It was isolated from spruce, Scots pine, and oak pile dwellings and from the Aqualadroni rostrum [23; 25]. The species belonging to this genus are usually isolated from soil but can also be animal and human pathogens [67; 68; 69; 70]. _Sphingomonas_ strains are able to degrade cellulose, lignin and lignin derivatives [57; 58; 59; 71]. Some of the identified genera never reported before in WAW deserve a special mention. The genus _Methylovigula_ was identified only in two samples N88 (silver fir) and PF (ash). It is part of the bacterial community present in decaying wood of the species _Fagus sylvatica_ (beech), _Picea abies_ and _Pinus sylvestris_[72; 73]. The species _Methylovigula ligni_ has been found on beechwood blocks attacked by white-rot fungi [74]. _Methylovigula_ bacteria are obligated methylotrophs, and can use methanol as the sole carbon source. Methanol is produced during the decomposition of woody materials and this could explain why these microorganisms are found in wood colonized by fungi and in advanced stages of decay [72; 73]. The genus _Bryobacter_ was identified in both Naples and Pisa samples. In the latter, it reached a relative frequency of 13%, while in N wood the frequency was always equal to or lower than 1%.