短小芽孢杆菌LC01的鉴定及其芽孢漆酶性质的研究

【目的】对前期获得的1株具有较高漆酶活性的细菌菌株LC01进行鉴定及相关酶学性质研究,以开发具有较好工业应用特性的细菌漆酶。【方法】通过形态观察和生理生化实验,结合16S rDNA序列分析对菌株进行鉴定,测定其芽孢漆酶在不同条件下的催化性质及染料降解能力。【结果】经鉴定菌株LC01为短小芽孢杆菌,该菌株的芽孢漆酶氧化底物2,2'-连氮-二(3-乙基苯并噻唑-6-磺酸)、丁香醛连氮和2,6-二甲氧基苯酚的最适pH分别为3.0、6.6和8.6,以丁香醛连氮为底物的最适催化温度为80 ℃,在pH 9.0放置10 d或50 ℃处理10 h后均有较高活性。在pH 9.0时,芽孢漆酶-介体系统能有效脱色不同结构的染料。对染料活性黑5和靛红反应1 h后脱色率达90%以上,对RB亮蓝的脱色6 h后也达到了90%。【结论】短小芽孢杆菌LC01的芽孢漆酶能有效脱色染料且在碱性和高温条件下具有良好稳定性,表明其在多种工业领域具有较好的应用前景。

Identification of Bacillus pumilus LC01 and characterization of its spore laccase

【Objective】The previously isolated bacterial strain Bacillus pumilis LC01 displaying high laccase activity was presently investigated to determine spore laccase activity, with the goal of obtaining bacterial laccase with excellent properties for industrial applications. 【Method】LC01 was identified by morphology observation, physiological and biochemical tests, and 16S rDNA sequence analysis. The catalytic properties and dye degradation ability of the spore laccase were investigated under different conditions. 【Result】LC01 was identified as B. pumilus. The optimum pH of LC01 spore laccase was 3.0, 6.6 and 8.6 using 2,2'-2(3-ethylbenzothiazole-6-sulfonic acid), syringaldehyde, and 2,6-dimethoxyphenol as substrates, respectively. The spore laccase showed an optimal temperature of 80 ℃for syringaldazine oxidation. Activity was retained at a high level after incubation at pH 9.0 for 10 days or 50 ℃ for 10 h. The spore laccase-mediator system could efficiently decolorize different synthetic dyes. More than 90% of reactive black 5 and indigo carmine were decolorized within 1 h. Approximately 90% of remazol brilliant blue R was also decolorized after 6 h.【Conclusion】The pronounced efficiency of dye decolorization and good stability under alkali and high temperature conditions indicate the potential of the spore laccase of B. pumilus strain LC01 for diverse industrial applications.