Rynket Klokkemorkel (Verpa bohemica) - en "ny" art for Danmark

STlayer in th e tr ach eid wall in a characteristic manner
(fig. 8). The dec ayed wood becomes grey with a
soft consistency. Examples: Fungi Imperfecti and Pyrenomycet
es.
O xalic acid has been show n to pl ay a significa nt
rol e in the primar y brake down processes of wood. It
is abl e to hydrolyze the hemicellulose that envelope
the cellulose and thus uneover th e cellulose to fur the r
brake do wn by cellulolytic enzymes. Th e endproduets
are watersoluble sugars. Oxalic acid is a low moleculal'
subs tance th at can pen etrat e th e cell wall. With
ca lcium it fo rms an insoluble sa lt, calcium oxal at e.
T his property ena bles th e fung us to reg ulate pH, so
that th e substrat e will not become to acid. Oxalic acid
may also chelat e with differ ent metals, a fur the r option
for pH regulation . Lar ge quantities of calciumoxa
late is th er efor e found in conne ction with brown
rot and in the litt er layer.
Litteratur
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Fugtigheitsverhåltnisse. Antworten auf
die Frage , waru m der Echte Haussch wamm nur
in H ansem vorko mmt. - M at eri al und Organi smen
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Bech-Andersen , J . 1986. The infiuence of the Dry
Rot Fungus (Serpula lacr ymans) in vivo on Insulation
Mat eri ais. - Materiel und Organi sm en Bd.
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Bech-Andersen, J. 1987. Production, function and
neutralisation of ox alic acid produced by the dr y
rot fun gus and othe r brown rot fun gi, - IRG/WPI
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Chandra, T.S. & Y I. She thna 1975. Isolation and
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Che mical Composition of Wood. I: Biomass Utilization,
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G oring , D .A.I. 1977. A speculative pietu re of the delignification
process. I: Ce llulose Ch emistry and
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A me rican Che mical Society Symposi um Series
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Graustein, W.e., K. Croma ck & P. Sollins 1977. Calcium
Oxalate: Occurence in soils and E ffect on
Nutrient and G eochemical Cycles . - Science 198:
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Brown-Rot D ecay. Materi al und Organism en
(i tr ykk en ).
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pp .
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(Fr.) Bref.
Shimada, M. et al. 1991. Biochemical R elationships
bet ween Biodegredation of Ce llulose and Formation
of Oxalic acid in Brown-Rot Wood D ecay.­
IRG/WP /1472.
.l.l'..\J1 vv c i i-e t c,