有机溶剂对米曲霉及荧光假单胞菌细胞毒性的研究

Toxicity of Organic Solvents to Microbial Cells with Catalytic Activity

摘要:

本文以米曲霉以及荧光假单胞菌为代表性霉菌及细菌型微生物，通过对菌体生长量、菌丝球大小以及显微观察，研究了常见有机溶剂对具有催化活性的微生物细胞的生长毒性。研究发现有机溶剂对真菌和细菌的毒性与其lgP值有密切关联关系，且与具体的溶剂种类有关。在针对米曲霉的研究中，正丙醇、叔丁醇和甲苯(lgP值分别为0.55、0.80、2.5)对菌丝球的形成有一定的抑制作用；当正丁醇与氯仿(lgP值分别为0.82、2.00)存在时菌丝质量为0， 即能完全抑制菌丝生长；丙酮，短链醇，长链烷烃等的存在对菌丝体总质量(0.81±0.07）和菌丝形态没有明显改变，但对生殖期以及孢子形态有显著影响。对荧光假单胞菌而言，正丁醇、氯仿、甲苯和辛烷（4.6 > lgP > 0.8）可以完全抑制菌体生长（OD560 < 1.17±0.05），其他溶剂存在时菌体生长与对照（OD560=2.27±0.05）无显著差异；此外，有机溶剂会影响培养过程中细胞的形状和细胞间的排列方式。

Abstract:

Using Aspergillus oryzae and Pseudomonas fluorescens as representative types of mold and bacteria microbes respectively, the toxicity of commonly-used organic solvents to the cell growth of microbial cell with catalytic activities was investigated through measurement of microbe growth, hypha ball size and microscopic observation,. It was found that the toxicity of organic solvent to fungi and bacteria has close relationship to its lgP value and also related to the type of solvent. For A. oryzae, n-propanol (lgP value 0.55), t-butanol (lgP value 0.80) and toluene (lgP value 2.5) inhibited the formation of the hypha ball. No mycelium formed when n-butanol (lgP value 0.82) and chloroform (lgP value 2.00) existed in the culture, indicating that they could complestely inhibite the growth of hypha. Though the existence of acetone, short chain alcohols and long chain alkanes hardly changed the total mycelium quality（0.81?0.07）and hypha morphology, they have significant effects on reproductive period and spore morphology. For P. fluorescens, the solvents with lgP values ranged in 0.8~4.6, including n-butanol, chloroform, toluene and octane, completely inhibited the growth of cells（OD560 < 1.17?0.05）. Other solvents made no significant differences from the control（OD560=2.27?0.05）in the bacteria growth. In addition, organic solvent will affect the cell shapes and the arrangement of the cells in the process of culturing.