陕西猕猴桃汁嗜酸耐热菌污染能力评测与多样性分析

Evaluation of Kiwi-fruit Juice Contaminant Capacity of Indigenous Alicyclobacillus and Its Biodiversity

以分离自陕西成熟猕猴桃的6株嗜酸耐热菌为研究对象,对这6株分离菌以及4株相应的标准菌株进行了猕猴桃汁污染能力评估,并对分离菌与标准菌株的常规生理生化指标进行了测定和对比分析。通过气质联用对不同菌株特征污染代谢产物形成能力检测、绘制热死亡曲线进行的抗热性差异检测,以及通过API鉴定系统进行碳源代谢谱分析和通过基因组DNA杂交实验复性速率测定,对嗜酸耐热菌群菌株的生物多样性进行评测。结果表明,分离菌株产污染物愈创木酚量可达10.56～34.74μg/L,在猕猴桃汁中D90℃值达到27.1～34.2 min,z值达到12.14～13.66℃;API实验结果表明,分离菌株与标准菌有3～19项糖代谢结果差异,与文献报道相应菌种不同菌株中有7～22项糖代谢差异;6株分离菌与标准菌DNA杂交率在74.75%～104.79%之间。实验结果表明：分离自陕西地产猕猴桃果汁的6株本土脂环酸芽孢杆菌（Alicyclobacillus）具有潜在污染猕猴桃果汁的能力,并具有一定的生物多样性。

In order to evaluate the potential risk of Alicyclobacillus contamination in Shaanxi kiwi fruit production line, six strains of Alicyclobacillus isolated from the production line were studied. The contaminant production capacity of six strains and four corresponding standard strains was evaluated, including detection of contaminant production using GC - MS and heat resistance through drawing thermal death curves, and its biodiversity was analyzed, including analysis of carbon source spectrum by API tests and detection of its DNA hybridizations from renaturation rates. The results showed that no 2, 6- dibromophenol and 2,6-dichlorophenol were detected, and the guaiacol production of six isolated strains was between 10.56 μg/L and 34.74 μg/L which was significantly higher than the common sensory detection threshold values in juices, D90℃ values of strains were 27.1 ～ 34.2 rain and the z values were 12. 14 ～ 13.66℃ in kiwi fruit juice, with the heat resistance of the three strains of A. acidoterrestris generally being higher than the data of former reports. There were 7 - 22 different results of API tests between the isolated strains and the data from published articles or their corresponding standard strains. The hybridizations between the isolated strains and their corresponding standard strains were between 74.75% and 104.79%. These results suggested that the isolated strains possessed potential contaminantproduction capacity and biodiversity to a certain extent which needed to be controlled.