Growth characteristics of fungi isolated from unearthed wooden cultural relics

  Objectives  This research was carried out to observe and analyze the biological characteristics and the biodeterioration characteristics of 11 fungi strains isolated from the wooden water flume unearthed at the Nanyue National Palace site, to provide data on the designing of high-performance protection measures for the unearthed wooden cultural relics and the healthy environment in the museum.

  Method  We inoculated the isolated fungi on the wood surface to observe the impact on the wood, tested the biodegradation degree of each fungus on the wood through the mass loss rate, and observed the biological characteristics such as growth rate, sporulation and microscopic characteristics by culture on different media, used the confrontation growth experiment to study their interaction.

  Result  The wood surface inoculation test showed that Cladophialophora sp., Trichoderma sp., Paecilomyces formosus, Talaromyces sp., Penicillium citreonigrum, Fusarium sp., Eutypella sp. and Arthrinium sp. stained or discolored the surface of wood. After 12-week wood degradation test, the mass loss of poplar wood was nearly 10% by Leucocoprinus birnbaumii. Among them, Trichoderma sp. grew fastest, nearly by 35 mm per day; Eutypella sp., Arthrinium sp., P. formosus and Fusarium sp., with a daily growth of 8−13 mm; L. birnbaumii, A. sydowii, P. citreonigrum, Talaromyces sp., Acremonium sp. and Cladophialophora sp., with a daily growth of less than 5 mm on PDA media. All the other fungi were easy to produce spores on different media, except for Eutypella sp., Arthrinium sp. and L. birnbaumii. Trichoderma YN4-5 had certain inhibitory effect on the growth of other fungi, with inhibition rate of 11.0% to 64.6% by confrontation growth test. YN4-5 had the highest inhibition rate to the basidiomycete L. birnbaumii.

  Conclusion  Eight ascomycetes of fungi strains isolated could cause stain or discolored on the surface of wooden cultural relics, and L. birnbaumii had risk of degrade to wooden cultural relics. Among them, Trichoderma sp. with the fastest growth can inhibit the growth of other fungi by competitive growth environment, and it has the greatest inhibitory effect on L. birnbaumii, which reduce the degradation risk of wooden cultural relics. Therefore, it is speculated that the microecological interaction on the unearthed wooden cultural relics in this museum has reached a balance.