''Serpula lacrymans'' is one of the

fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...

that cause damage to timber referred to as dry rot. It is a

basidiomycete Basidiomycota () is one of two large divisions that, together with the Ascomycota, constitute the subkingdom Dikarya (often referred to as the "higher fungi") within the kingdom Fungi. Members are known as basidiomycetes. More specifically, Basi ...

in the order

Boletales The Boletales are an order of Agaricomycetes containing over 1300 species with a diverse array of fruiting body types. The boletes are the best known members of this group, and until recently, the Boletales were thought to only contain boletes. T ...

. The ''Serpula lacrymans'' has the ability to rapidly colonise sites through unique and highly specialised mycelium which also leads to greater degradation rates of wood cellulose.

Taxonomy

The species was first described under the name ''Boletus lacrymans'' by

Franz Xavier von Wulfen Franz Xaver Freiherr von Wulfen (5 November 1728 – 17 March 1805) was an Austrian botanist, zoologist, mineralogist, alpinist, and Jesuit priest. He is credited with discovering the flowering plants ''Wulfenia carinthiaca'', ''Saxifraga mo ...

in 1781. It was transferred to the genus '' Serpula'' by

Petter Karsten Petter Adolf Karsten (16 February 1834 – 22 March 1917) was a Finnish mycologist, the foremost expert on the fungi of Finland in his day, and known in consequence as the "father of Finnish mycology". Karsten was born in Merimasku near Turku, s ...

in 1884. The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

is derived from the

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

words ''serpula'' for "creeping" (as in a serpent) and ''lacrymans'', meaning "making tears".

Environment

''Serpula lacrymans'' has a preference for temperatures of but can survive any temperature from . It is not clear how much light is needed to promote ''Serpula lacrymans'' growth. In terms of aeration ''Serpula lacrymans'' often grows near ventilation shafts which shows a preference for concentrated oxygen. A moisture content of 30 to 40 percent is its ideal level in wood to promote fruit body formation. It appears that ''Serpula lacrymans'' requires an environment where both inorganic and organic materials are present. The fungus uses

calcium Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to ...

and iron

ion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conven ...

s extracted from

plaster Plaster is a building material used for the protective or decorative coating of walls and ceilings and for Molding (decorative), moulding and casting decorative elements. In English, "plaster" usually means a material used for the interiors of ...

brick A brick is a type of block used to build walls, pavements and other elements in masonry construction. Properly, the term ''brick'' denotes a block composed of dried clay, but is now also used informally to denote other chemically cured cons ...

, and stone to aid the breakdown of wood, which results in brown rot.

Distribution

Although it is a common indoor biodeterioration agent, it has only been found in a few natural environments, the

Himalayas The Himalayas, or Himalaya (; ; ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the planet's highest peaks, including the very highest, Mount Everest. Over 100 ...

Northern California Northern California (colloquially known as NorCal) is a geographic and cultural region that generally comprises the northern portion of the U.S. state of California. Spanning the state's northernmost 48 counties, its main population centers incl ...

, the

Czech Republic The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The ...

and east Asia. A recent study on the evolutionary origin and spread of this species using genetic markers ( amplified fragment length polymorphisms, DNA sequences and

microsatellite A microsatellite is a tract of repetitive DNA in which certain DNA motifs (ranging in length from one to six or more base pairs) are repeated, typically 5–50 times. Microsatellites occur at thousands of locations within an organism's genome. ...

s) on a worldwide sample of specimens suggested the existence of two main lineages, a nonaggressive lineage found in North America, and an aggressive lineage found on all continents, both in natural environments and buildings.

Impact on structures

''Serpula lacrymans'' is considered to be the most damaging destroyer of indoor wood construction materials in

temperate In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout t ...

regions. In the United Kingdom alone, building owners spent at least £150 million annually to rectify damage caused by dry rot. Serpula lacrymans (mycelial cords emanating from door)

Serpula lacrymans (mycelial cords emanating from door)

Genome

Three variants/strains of ''S. lacrymans'' have been sequenced by the Joint Genome Institute (JGI) and its collaborators, and sequence data is available via their MycoCosm portal. One genome is from ''S. lacrymans'' S7.9 (v2.0). The genome assembly is 42.73 Mbp, with a predicted number of 12789 genes. The second genome is from ''S. lacrymans'' S7.3 (v2.0). The genome assembly is 47 Mbp, with a predicted number of 14495 genes. The third genome is from ''S. lacrymans'' var ''shastensis'' SHA21-2 (v1.0). The genome assembly is 45.98 Mbp, with a predicted number of 13805 genes.

Natural products genes

The ''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). ''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., 2016).

Natural products

The genus ''Serpula'', including ''S. lacrymans'' and ''S. himantoides'', is known to produce three classes of chemical compounds:

pulvinic acid Pulvinic acids are natural chemical pigments found in some lichens, derived biosynthetically from the aromatic amino acids phenylalanine and tyrosine, via dimerization and oxidative ring-cleavage of aryl pyruvic acids, a process that also produ ...

-type family, himanimides, and polyine acids. Within the pulvinic acid-type family,

atromentin Atromentin is a natural chemical compound found in Agaricomycetes fungi in the orders Agaricales and Thelephorales. It can also be prepared by laboratory synthesis. Chemically, it is a polyphenol and a benzoquinone. Occurrences Atromentin has ...

-derived compounds include

variegatic acid Variegatic acid (3,3',4,4'-tetrahydroxypulvinic acid) is an orange pigment found in some mushrooms. It is responsible for the bluing reaction seen in many bolete mushrooms when they are injured. When mushroom tissue containing variegatic acid is e ...

xerocomic acid Xerocomic acid is a red-orange pigment found in fungi of the order ''Boletales'' (and is named after the genus ''Xerocomus''). It is the precursor to variegatic acid, and is preceded by atromentic acid and atromentin. As an example, it is isolated ...

isoxerocomic acid Isoxerocomic acid is a red-orange pigment found in ''Boletales''. It is the precursor to variegatic acid, and is preceded by atromentic acid and atromentin. As an example, it is isolated from ''Serpula lacrymans''. It is soluble in methanol. It is ...

atromentic acid Atromentic acid is a red-organge pigment found in fungi within the Boletales group. It is the precursor to variegatic acid and xerocomic acid, and is preceded by atromentin. As an example, it is isolated from ''Serpula lacrymans''. It is soluble i ...

variegatorubin Variegatorubin is a pulvinic acid derivative. It is a red pigment that is present in many members of the Boletales, an order of the division Basidiomycota. It is generated from the oxidation of variegatic acid. Bolete species that contain varieg ...

xerocomorubin Xerocomorubin is a pigment from the fungus order Boletales. It is the oxidized form of isoxerocomic acid. Air oxidation is responsible its formation, and it oxidizes faster to a similar pulvinic acid type pigment oxidized variant, variegatorubin ...

, and other variants of these pigments. Pulvinic acid-type family pigments were found to be secreted during co-incubation with various bacteria.Tauber et al., 2016

References

{{Authority control Boletales Wood-decay fungi Fungi described in 1781 Fungi of Asia Fungi of Europe Fungi of North America