Dry rot species of fungi cause brown rot decay, preferentially removing cellulose and hemicellulose from the timber leaving a brittle matrix of modified lignin. The term "dry rot" is somewhat misleading, as both species of fungi "Serpula lacrymans" and "Meruliporia incrassata" require an elevated moisture content to initiate an attack on timber (28–30%). Once established, the fungi can remain active in timber with a moisture content of more than 20%. At relative humidities below 86 percent, growth of "Serpula lacrymans" is inhibited, but it can stay dormant at relative humidities down to 76 percent. These relative humidities correspond to equilibrium moisture contents
Serpula lacrymans of 13805 genes. "S. lacrymans"' genome encodes six annotated polyketide synthases (PKS1-PKS6), 15 nonribosomal peptide synthetases (NPS1-NPS4, NPS7, NPS13-NPS15, NPS17, and NPS18), and two hybrids thereof (NPS6, NPS8, and NPS16). Additionally, the genome encodes for various putative adenylate-forming reductases (NPS5, NPS9-NPS12) (Eastwood et al., 2011). "NPS3" was overexpressed in E. coli and characterized as an atromentin/quinone synthetase that catalyzes the formation of atromentin, similar to GreA; InvA1,2 and 5; and AtrA from Suillus grevillei, Tapinella panuoides, Paxillus involutus, respectively. "NPS3" and its adjacent clustered aminotransferase gene ("AMT1") were also found to be up-regulated during co-incubation with bacteria (Tauber et al.,