非灭菌条件下白腐真菌在反应器中的形态特征变化

Morphological Characteristics of Phanerochaete chrysosporium in a Reactor Operated under Non-Sterile Conditions

揭示白腐真菌（Phanerochaete chrysosporium）在反应器中的形态变化有助于了解白腐真菌反应器难以连续运行问题的本质.在耦合臭氧单元的反应器对酸性蓝45连续降解的过程中,考察了非固定化和固定化菌丝系统中白腐真菌的形态特性变化.结果表明,在接种量为1 700 mg/L的非固定化系统中,染菌量为7.1×10^5CFU/mL,平均脱色率为19%;但菌丝球形态不稳定,运行8~12 d时出现破裂、菌丝脱落、内容物大量流失,污染微生物的生长加剧.在固定化系统中,接种量为1 700 mg/L时,染菌量降至8.4×10^4CFU/mL,平均脱色率升至22%;接种量为4 300 mg/L时,染菌量降至4.7×10^4CFU/mL,平均脱色率达29%.在固定化菌丝系统中,白腐真菌的形态相对稳定,但21 d后,其稳定性降低,也出现了菌丝脱落现象,这与菌丝球或固定化菌丝的内部菌丝老化和自溶有关,可以考虑通过设计新载体从生物膜的内部和外部同时供给营养物和氧气解决该问题.

To clarify the morphological characteristics of white-rot fungi is helpful for achieving the continuous operation of white-rot fungal reactor. The white-rot fungal reactor coupled with an ozone unit was operated continually to degrade acid blue 45. The morphological changes of immobilized and non-immobilized white-rot fungi was investigated. The results showed that contaminating microorganisms can be controlled at 7.1 × 10^5 CFU/mL and the average decolorization of acid blue 45 achieved 19% in the non-immobilized mycelium system inoculated with 1700 mg/L P. chrysosporlum, but the pellet of P. chrysosporium were unstable, the hyphal fragments fallen-off from the pellet surface after 8-12 days operation and some pellets ruptured. The cell contents outflew from those ruptured hyphae, by which contaminating microorganisms were nourished. In contrast, the systems inoculated with 1700 mg/L immobilized mycelium of P. chrysosporium have low numbers of contaminating bacteria （8.4 × 10^4 CFU/mL） and a high dye removal rate （22%） ; Contaminating bacteria can be controlled at 4. 7 × 10^4 CFU/mL, the average decolorization achieved 29% in the immobilized mycelium system inoculated with 4300 mg/L immobilized mycelium of P. chrysosporium. In the immobilized mycelium system, some hyphal fragments also fallen-off from the immobilized mycelium surface after 21 days reactor operation. The hyphal fragments fallen-off from the pellets or immobilized mycelium correlated with the aging and autolysis of hyphal that could interfere with the continuous grow of white-rot fungi, which may be solved by using novel carrier by which nutrient substance and oxygen can be supplied from the internal and external of the attached biofilms to promoted the continuous growth of white-rot fungi.