高碘地下卤水中细菌产碘氧化酶的影响因素

高碘地下卤水的细菌碘氧化过程可以减轻工艺管线的生物污损危害。分离自高碘地下卤水中的细菌Roseovarius sp.IOB-7,其分泌的碘氧化酶可催化氧化碘离子生成能够抑制敏感菌生长的碘单质,从而减少生物污损。实验结果显示,加入16μmol/L的Cu~(2+)可促进IOB-7的生长,并将碘氧化酶活力提高了1.75倍。碘氧化酶的最适反应温度为50℃,最适pH为5.5。以碘离子为底物的催化氧化反应中,当pH值为9时,Trametes versicolor漆酶已经完全失活,而碘氧化酶则仍然保持了32%的相对酶活力,显示出更好的pH应用范围和稳定性。开展高碘地下卤水环境中细菌碘氧化酶的研究,对利用生物酶法进行工艺管线生物污损的防治有积极的指导意义。

IMPACT FACTORS ON BACTERIAL IODIDE OXIDIZING ENZYME IN IODIDE-RICH UNDERGROUND BRINE

The bioclogging in the pipelines was inhibited due to the bacterial iodide oxidization in iodide-rich underground brine.Roseovarius sp.IOB-7 was isolated from the underground brine,and the iodide concentration was 131 mg/L.Since the growth of sensitive bacteria was inhibited by the iodine,which oxidized by the iodide oxidizing enzyme,the bioclogging in the pipelines was mitigated.The iodide oxidizing enzyme was produced by Roseovarius sp.IOB-7.With addition of 16 μmol/L Cu2+,the growth of IOB-7 was increased and the activity of iodide oxidizing enzyme was enhanced by 1.75 times.The optimum temperature and pH for the iodide oxidizing enzyme in the iodide oxidization was 50 ℃ and 5.5,respectively.Compared with laccase from Trametes versicolor,iodide oxidizing enzyme kept more active when pH range varied from 4.0 to 9.0 in the iodide oxidizing reaction.Especially,iodide oxidizing enzyme still kept relative enzyme activity of 32％ at pH 9,whereas the laccase has been inactive.Iodide oxidizing enzyme would be concerned as a disinfectant/synergist in the iodide-rich environment for preventing the biocologging in the pipelines.