Studies on histamine-decomposing bacteria in marine food products

组胺（Hm）被认为是鲭鱼中毒的致病化合物。鱼肉在贮藏过程中Hm的积累不仅取决于产Hm菌，而且还取决于分解Hm菌。然而，大多数关于海产品Hm问题的研究都集中在产Hm细菌的种类及其产Hm的能力上，而对Hm的分解几乎没有研究。为了阐明Hm积累的机理，研究了Hm分解菌在鱼肉贮藏过程、草草肉汁、鱼露和盐原中的分布和作用。研究结果如下：在5和30‰的温度下，对青花鱼在1年内各2个月的贮藏过程中，产生Hm和分解Hm的细菌数量和Hm含量的变化进行了研究。当样品在5ºC的温度下保存时，由于Hm分解菌的作用，样品的Hm含量一旦积累，就会逐渐减少并消失，pH值变为中性，大于10^6/g。在30ºC的贮藏条件下，细菌的Hm含量并不总是降低，这表明细菌的Hm分解能力可能在30ºC的贮藏条件下受到抑制。恶臭假单胞菌似乎在分解鱼肉贮藏过程中积累的Hm中起主要作用。发现样品中多胺含量的变化并不总是遵循相同的一般模式，并且与分解的进展无关。所以多胺不能作为鱼类分解的可靠指标。草屋肉汁中产生组胺的细菌不多于10^1/ml，分解hm的细菌不多于10^4-10^6/ml。草草肉汁的pH值处于细菌分解Hm的最佳范围。因此，可以假设Hm几乎不会在草谷肉汁中积累。鱼露Hm含量为30 ~ 71mg/100ml。在20%-NaCl培养基上产Hm菌数为8*10^2/ml，表明在盐浓度极高的鱼露中可能产生Hm。在盐冈发酵过程中，未检出产hm和分解hm的细菌。结果表明，盐原地区几乎没有Hm积累现象。少

Histamine (Hm) is known as the causative compound of scombroid fish poisoning. The accumulation of Hm during the storage of fish meat does not depend only on Hm-producing bacteria but also on Hm-decomposing bacteria. Most studies concerning Hm problems of sea products, however, have focussed on the type of Hm-producing bacteria and their avility to produce Hm, while the decomposition of Hm has hardly been studied. In order to clarify the mechanisms of Hm accumulation, the distribution and roles of Hm-decomposing bacteria during the storage of fish meat, and in kusaya gravy, fish sauce and shiokara were studied. The results are as follows ;Changes in the numbers of both Hm-producing and Hm-decomposing bacetria and Hm contents were examined during the storage of common mackerel at 5 and 30ﾟC for two months each throughout a year. In the case of samples stored at 5ﾟC,the Hm contents, once accumulated, decreased and disappeared when the sample putrefied as Hm-decomposing bacteria took over … More (more than 10^6/g) and the pH value became neutral. At 30ﾟC storage, the Hm content did not always decrease, suggesting the Hm-decomposing ability of the bacteria might therefore be inhibited at 30ﾟC.Pseudomonas putida seemed to play a major role in the decomposition of Hm accumulated during the storage of the fish meat.It was found that changes in polyamine contents in the samples did not always follow the same general pattern and did not correlate with the progress of decomposition. So polyamines would not be a reliable indicator of fish decomposition.Kusaya gravy had none or less than 10^1/ml histamine-producing bacteria and 10^4-10^6/ml of Hm-decomposing bacteria. The pH values of kusaya gravy were in the optimal range for bacterial Hm decomposition. It is therefore assumed that Hm hardly accumulates in kusaya gravy.Hm contents of fish sauce were 30-71mg/100ml. Hm-producing bacteria counted on 20%-NaCl medium was 8*10^2/ml, suggesting the possible production of Hm in fish sauce containing extremely high salt concentration.During the fermentation process of shiokara, neither Hm-producing nor Hm-decomposing bacteria were detected. It was suggested that Hm accumulation hardly occurs in shiokara. Less