Selection of stain fungi on rubberwood (Hevea brasiliensis) and its growth response against chitosan

Abstract

Abstract. Salman ABA, Sudirman LI, Nandika D. 2020. Selection of stain fungi on rubberwood (Hevea brasiliensis) and its growth response against chitosan. Biodiversitas 21: 4501-4508. Rubberwood (Hevea brasiliensis Muell. Arg.) is one of the most important raw materials in furniture industry in South East Asian countries, particularly in Indonesia, Thailand and Malaysia. However, due to its susceptibility to stain fungi attack, wood preservative is needed to processing this material, which has both significant cost and environmental implications. A laboratory study was conducted to identify the seasoned rubberwood attacking stain fungi and to evaluate the bioactivity of chitosan in inhibiting the stain fungi’s growth. Isolation fungi from seasoned rubberwood were obtained firstly then selection isolates were conducted in the rubberwood test samples. Isolates with the highest percentage growth on wood test samples would identify based on internal transcribed spacer (ITS) region. Chitosan were prepared in four concentration 0, 0.5, 1 and 2% (w/v). Two isolates were showed the highest percentage growth on wood test samples after six weeks, which were 90.6% for isolate code I4 and 96.2% for II4 and both isolates gained scores 5. The two isolates were identified as Aspergillus foetidus for I4 and Aspergillus aflatoxiformans for II4. Aspergillus foetidus and A. aflatoxiformans would be the newly recorded species and this is the first report about species description from rubberwood in Indonesia. The inhibition rate was increased when chitosan concentration was increased from 0 to 2%. Chitosan concentration 2% inhibited the growth of A. foetidus in 20.28%, but there is no inhibition showed on A. aflatoxiformans. The addition of chitosan in medium can increase the growth of A. aflatoxiformans and forming clear zone around the colony.

Chemical Components of Fungus Comb from Indo-Malayan Termite Macrotermes gilvus Hagen Mound and Its Bioactivity against Wood-Staining Fungi

“…The is discoloration influenced by melanin crystallization around hyphae or from secretion of extracellular material [17]. Salman et al [18] reported that Aspergillus foetidus caused the worst discoloration on air-dried rubberwood, which is processed for furniture products in West Java Province, Indonesia. The growth rate of fungus on the wood surface reached 90.5%.…”

“…Particularly in the rainy season, rainwater containing nutrients wets the wood, thus promoting biodeterioration activities of fungi [23]. In 2018, economic loss due to stain fungi attacks on rubberwood raw material in Indonesian furniture industry alone reached almost USD 15,246 million [18]. In fact, this economic loss is higher than the value since others light-color wood species used in the furniture industry were also susceptible to stain fungi.…”

“…Unfortunately, most of the wood from the plantation forests is highly susceptible to biodeterioration, including susceptibility to wood-staining fungi attacks [25]. Such attacks contribute to the discoloration of the wood surface, i.e., changing it to blue, grayish, green, or black, considerably lessening its aesthetic value [18]. Valiante et al [26] argued that discoloration is caused by pigmentation on the hyphae or melanin synthesis on the conidia during the sporulation process.…”

“…), is Aspergillus spp. [18]. This situation requires multiple approaches, including the exploration of organic fungicide that is safe for humans and the environment, the active ingredients of which are originally produced from indigenous natural resources.…”

Morphological and molecular features of stain fungi infecting rubberwood (Hevea brasiliensis)

“…Previous studies reported that three stain fungi species were identified from rubberwood, which were Aspergillus niger, Aspergillus flavus, and Penicillium citrinum (Oldertrøen et al 2016). Meanwhile, Salman et al (2020) reported that at least there were two stain fungi isolated from air dried rubberwood which will be processed for furniture products in West Java Province, Indonesia, which were Aspergillus aflatoxiformans and A. foetidus. In addition, Razali et al (2016) reported that there were seven isolates obtained from rubberwood and classified into three groups, namely Fusarium equiseti, Mucor irregularis, and Lasiodiplodia theobromae.…”