腌韭菜根中腐败菌的分离鉴定及防腐剂对其抑制作用

Isolation and Identification of Spoilage Bacteria from Pickled Leek Root and Its Inhibition by Preservatives

以胀袋变质的真空包装韭菜根为原料,采用纯培养法从中分离筛选腐败微生物。通过形态学观察、生理生化试验和16S rRNA基因序列分析对其主要腐败菌进行了鉴定,并研究了防腐剂对主要腐败菌的抑制作用。结果表明导致腌韭菜根胀袋变质的优势腐败菌主要为5株芽孢杆菌属细菌,经鉴定由3株Bacillus megaterium和2株Bacillus toyonensis组成;防腐剂抑菌试验得出,苯甲酸钠、山梨酸钾、脱氢乙酸钠、EDTA和焦亚硫酸钠5种防腐剂对5株腐败菌的IC50分别为5.63~10.11、11.24~31.33、10.07~18.60、20.68~40.70、15.74~36.37μg/mL,抑菌效果依次为:苯甲酸钠>脱氢乙酸钠>山梨酸钾>焦亚硫酸钠>EDTA。

Vacuum packed leek root that has degenerated in bulging bag was used as raw material to separate and screen spoilage microorganism by pure culture method.The main spoilage bacteria were identified by morphological observation,physiological and biochemical test and 16S rRNA gene sequence analysis.The inhibitory effect of preservatives on the main spoilage bacteria was also studied.The results showed that the dominant spoilage bacteria causing vacuum bag expansion and pickled leek root rot were five strains of bacteria,which was identified to be composed of three Bacillus megaterium and two Bacillus toyonensis.Antiseptic and antibacterial experiments showed that the IC50 of sodium benzoate,potassium sorbate,sodium dehydroacetate,EDTA and sodium pyrosulfite against the spoilage bacteria were 5.63~10.11,11.24~31.33,10.07~18.60,20.68~40.70,15.74~36.37μg/mL,respectively.The bacteriostatic effects were successively as follows:sodium benzoate>sodium dehydroacetate>potassium sorbate>sodium metabisulfite>EDTA.