藏羊肉中优势腐败不动杆菌的分离鉴定及其生物膜形成特性

Isolation and identification of Acinetobacter in Tibetan mutton and the biofilm formation characteristics

本研究从冷鲜藏羊肉中共分离获得40株腐败菌,其中10株为不动杆菌,经结晶紫染色定量检测发现10株不动杆菌均具有中等或强粘附成膜能力。对1株成膜能力最强的不动杆菌A3的成膜特性进行深入分析,发现该菌在培养3 d时生物膜内菌数最高,随后培养5 d至7 d时菌数无显著(P>0. 05)变化。扫描电镜、激光共聚焦显微镜观察及胞外多糖质量浓度测定结果表明,该菌形成生物膜的过程中培养1 d到3 d细菌迅速繁殖,培养3 d到5 d,菌体聚集成团,并且此时不可溶性多糖的含量最高,培养7 d时胞外分泌物质减少,生物膜出现解离状态。因此,在藏羊肉加工过程中,针对此菌生物膜抑制的研究可着重关注控制胞外物质的分泌,并且在生物膜未成熟前实施消毒措施,有助于彻底杀灭生物膜内的腐败菌。

In this study,forty food spoilage strains were isolated and identified from the Tibetan mutton,and ten strains were Acinetobacter sp.Quantitative detection results by crystal violet staining showed that ten strains of Acinetobacter had neutral or strong adhesion ability.The biofilm formation characteristics of Acinetobacter A3 with the best biofilm forming ability were analyzed.It was found that the bacterial count in biofilm was the highest when biofilm was cultured for three days,and there was no significant change in the number of bacteria on the 5th to 7th day after culture.The results of scanning electron microscopy,confocal laser scanning microscopy and extracellular polysaccharide determination concentration showed that bacteria propagated rapidly from one to three days in the process of biofilm formation.When the biofilm was cultured for three to five days,the bacteria aggregated into groups,and the insoluble polysaccharide content was highest.The extracellular substances were decreased and the biofilm became dissociated when it was cultured for seven days.During the processing of Tibetan mutton,the secretion of extracellular substances should be paid more attention for biofilm inhibition research,and disinfection measures should be implemented before the biofilms matured in order to kill the spoilage bacteria.