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林业科学 ›› 2021, Vol. 57 ›› Issue (2): 160-167.doi: 10.11707/j.1001-7488.20210216

• 论文与研究报告 • 上一篇    下一篇

漆酶催化碘化竹材的防腐性能

饶瑾1,2,王慧1,NayebareKakwara Prosper1,王婕1,姜俊1,杨秀树1,刘庭菘1,孙芳利1,*   

  1. 1. 浙江农林大学工程学院 杭州 311300
    2. 杭州市化工研究院有限公司 杭州 310014
  • 收稿日期:2019-01-25 出版日期:2021-02-25 发布日期:2021-03-29
  • 通讯作者: 孙芳利
  • 基金资助:
    国家自然科学基金项目(31470587);浙江自然科学基金重点项目(LZ14C160002)

Anti-Decay Performance of Bamboo Treated By Laccase Catalyzing Iodide

Jin Rao1,2,Hui Wang1,Kakwara Prosper Nayebare1,Jie Wang1,Jun Jiang1,Xiushu Yang1,Tingsong Liu1,Fangli Sun1,*   

  1. 1. School of Engineering Zhejiang A & F University Hangzhou 311300
    2. Hangzhou Research Institute of Chemical Technology Co., Ltd Hangzhou 310014
  • Received:2019-01-25 Online:2021-02-25 Published:2021-03-29
  • Contact: Fangli Sun

摘要:

目的: 利用漆酶催化氧化碘化物产生碘自由基的特性,将具有杀菌或抑菌作用的活性成分固着于竹材上,提高竹材的防腐性能和抑菌成分的固着性,为木竹材保护和改性提供一种环保、高效的新方法。方法: 以2,2'-联氮双(3-乙基苯并噻唑啉-6-磺酸)二铵盐(ABTS)为促进剂,采用不同酶活的漆酶催化碘化竹材,通过14天流失试验和室内耐腐性试验测试流失前后竹材的防腐性能,运用扫描电镜(SEM)和X射线光电子能谱(XPS)对防腐竹材的形貌和成分进行表征。结果: 单独碘化钾处理竹材具有一定的防腐效果,但质量损失率均在10%以上。采用不同酶活的漆酶催化碘化竹材可进一步提高竹材防腐性能,酶活0.60 U·mL-1的漆酶催化碘化竹材防腐效果最佳。经白腐菌腐朽3个月后,漆酶催化碘化竹材质量损失率为7.92%,流失试验后防腐竹材质量损失率增至9.85%,仍属于Ⅰ级耐腐。与白腐菌相比,褐腐菌对竹材的降解更严重,未处理竹材质量损失率高达24.95%,酶活0.60 U·mL-1的漆酶催化碘化竹材质量损失率为9.44%,流失试验后防腐竹材质量损失率变化幅度小,增加0.91%,而单独碘化钾处理竹材质量损失率从流失前的14.30%增至15.34%,漆酶催化碘化竹材具有较好的防腐性能和抗流失性能。从SEM可见,未处理竹材腐朽试验后细胞壁出现明显穿孔现象,特别是褐腐菌,部分穿孔连成一片,细胞完整性已严重破坏,而酶活0.60 U·mL-1的漆酶催化碘化竹材菌丝较少,细胞壁结构较完整。XPS分析表明,处理竹材经14天流失试验和3个月耐腐性测试,白腐菌和褐腐菌对其氧化降解程度均不高,漆酶催化碘化竹材不仅能抑制竹材细胞壁遭受白腐菌和褐腐菌降解,而且具有较好的抗流失性。结论: 漆酶催化碘化竹材可提高碘在竹材中的固着性,对白腐菌和褐腐菌具有较好的抵抗力,漆酶催化碘化竹材的耐腐性能高于单独碘化钾处理,是一种抗流失性强、高效且环保的新型竹材防腐技术。

关键词: 毛竹, 漆酶, 碘, 流失处理, 防腐性能

Abstract:

Objective: Potassium iodide was catalyzed by laccase and the iodine free radicals produced from the reaction could be fixed on bamboo, which was expected to improve the leaching resistance as well as the decay resistance. In this paper, enzymatic catalyzation was applied to fix antifungal agents on bamboo, which would provide an ecological and effective method for the protection and modification of wood and bamboo. Method: Using ABTS as mediator, bamboo blocks were iodized in different activities of laccase and potassium iodide(KI) combinations. The decay resistance of treated bamboo before and after 14 days was tested. The morphology and components of treated bamboo were characterized by means of scanning electron microscopy(SEM) and X-ray photoelectron spectroscopy(XPS). Result: Bamboo treated with KI alone showed limited decay resistances with a mass loss rate(ML) above 10%, while the ML of laccase catalyzed iodization of bamboo revealed better decay resistances comparing with KI alone treated ones. The best performance for bamboo protection was laccase activity at 0.60 U·mL-1 (0.60LAK). The mass loss rate of bamboo iodized by 0.60 U·mL-1 laccase(0.60LAK) was 7.92 % when exposed to Trametes versicolor after 3 months. After leaching, the mass loss rate increased to 9.85%, still belonged to Ⅰ decay resistance. Gloeophyllum trabeum degraded bamboo more vigorously than white rot fungi T. versicolor, causing about 24.95% mass loss rate for the untreated bamboo. The mass loss rate of 0.60 U·mL-1 laccase iodized bamboo was 9.44%, after leaching the ML increased by 0.91%. The mass loss rate of KI alone treated one increased from 14.30% to 15.34%. Accordingly, laccase catalyzed iodination of bamboo was an effective method for bamboo against decay fungi. SEM presented clear grooves and serious damage in the structure of untreated bamboo after leaching, especially G. trabeum. Some pits were enlarged even connected together, and the integrity of cell was much destroyed. However, 0.60 U·mL-1 laccase iodized bamboo showed a less destruction and no obvious mycelia existed. XPS analyses showed that the leached 0.60LAK samples were slightly oxidized by T. versicolor and G. trabeum. The results indicated that bamboo treated with KI-laccase could inhibit the cell wall degradation caused by T. versicolor and G. trabeum, which also had a good leaching resistance. Conclusion: The treatment of bamboo with the KI-laccase mediator systems could improve both the fixation of iodine and decay resistance, the decay resistance of laccase catalyzed iodization of bamboo was higher than that of KI alone treated. Thus, the KI-laccase mediator system might be an effective and ecological way to protect bamboo against decay fungi.

Key words: bamboo, laccase, iodide, leaching treatment, decay resistance

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