Montville T J
Appl Environ Microbiol. 1983 Feb;45(2):571-5. doi: 10.1128/aem.45.2.571-575.1983.
Reports that Clostridium botulinum toxin can sometimes be detected in the absence of indicators of overt spoilage led to a systematic study of this phenomenon in a model system. Media with various combinations of pH (5.0 to 7.0) and glucose (0.0 to 1.0%) were inoculated with vegetative cells of C. botulinum 62A and incubated anaerobically at 35 degrees C. Although growth and toxin production occurred at all pH and glucose combinations, accumulation of gas was delayed or absent in media with low pH, low glucose levels, or both. Other proteolytic C. botulinum strains gave similar results. Trypsin activation was required to detect toxin in some low pH cultures. The trypsinization requirement correlated with low proteolytic activity in the cultures. Proteolytic activity of the strains examined was 5- to 500-fold lower in botulinal assay medium than in cooked meat medium. The results indicate that the absence of gas accumulation does not preclude the presence of botulinal toxin and that proteolytic cultures grown under adverse conditions may require trypsinization for the detection of toxin.
有报道称，在没有明显腐败迹象的情况下，有时也能检测到肉毒梭菌毒素，因此对该现象在一个模型系统中进行了系统研究。用肉毒梭菌62A的营养细胞接种含有不同pH值（5.0至7.0）和葡萄糖（0.0至1.0%）组合的培养基，并在35℃下厌氧培养。尽管在所有pH值和葡萄糖组合条件下都有生长和毒素产生，但在低pH值、低葡萄糖水平或两者兼有的培养基中，气体积累会延迟或不出现。其他蛋白水解性肉毒梭菌菌株也得到了类似结果。在一些低pH值培养物中，需要用胰蛋白酶激活才能检测到毒素。胰蛋白酶处理的需求与培养物中低蛋白水解活性相关。在所检测的菌株中，肉毒检测培养基中的蛋白水解活性比熟肉培养基中的低5至500倍。结果表明，气体积累的缺乏并不排除肉毒毒素的存在，并且在不利条件下生长的蛋白水解培养物可能需要用胰蛋白酶处理才能检测到毒素。
