鲜湿豆丝中优势腐败菌的分离鉴定及ε-聚赖氨酸盐酸盐/丙酸钙复配抑菌研究

Isolation and Identification of Dominant Spoilage Bacteria from Fresh and Wet Bean Shreds and Study on Antibacterial Activity of ε-Polylysine Hydrochloride Combined with Calcium Propionate

鲜湿豆丝中水分含量高,易使微生物生长繁殖,导致鲜湿豆丝腐败变质。为延长鲜湿豆丝的货架期,延缓微生物的生长速率,采用平板划线法从腐败鲜湿豆丝中分离出7株腐败菌,经鉴定为4株枯草芽孢杆菌(X_(1)、X_(2)、X_(3)、X_(6))、1株苏云金芽孢杆菌(X_(4))、1株阿氏肠杆菌(X_(5))、1株考氏科萨克氏菌(X_(7))。将无菌鲜湿豆丝接种分离出的腐败菌,以菌落总数与酸度为检测指标,评价腐败菌的致腐能力。结果表明,接种了腐败菌的样品,其菌落总数与酸度均大于对照组,表明7株腐败菌均有较强的致腐能力。通过滤纸片法测定抑菌圈大小,研究不同浓度复配抑菌剂(ε-PL与CP)对7株腐败菌的抑菌效果。其中,40%ε-PL+60%CP、20%ε-PL+80%CP两种抑菌剂对腐败菌有较好的抑制作用。

The high moisture content in fresh and wet bean shreds can easily promote the growth and reproduction of microorganisms,leading to the spoilage and deterioration of fresh and wet bean shreds.In order to extend the shelf life of fresh and wet bean shreds and slow down the growth rate of microorganisms,seven strains of spoilage bacteria are isolated from spoiled fresh and wet bean shreds by streak plate method,and they are identified as four strains of Bacillus subtilis(X_(1),X_(2),X_(3),X_(6)),a strain of Bacillus thuringiensis(X_(4)),a strain of Enterobacter asburiae(X_(5))and a strain of Kosakonia cowanii(X_(7)).The isolated spoilage bacteria are inoculated onto sterile fresh and wet bean shreds,and the total number of colonies and acidity are used as the detection indexes to evaluate the spoilage ability of the spoilage bacteria.The results show that the total number of colonies and acidity of the samples inoculated with spoilage bacteria are all higher than those of the control group,indicating that the seven strains of spoilage bacteria have strong spoilage ability.The size of the antibacterial zone is measured by filtering paper method to study the antibacterial effects of different concentrations of compound antibacterial agents(ε-PL and CP)on seven strains of spoilage bacteria.Among them,40% ε-PL+60%CP,20% ε-PL+80%CP have good antibacterial effects on spoilage bacteria.