耐热乳酸菌肉品天然发酵剂的筛选鉴定

为获得发酵性能优良且具有较好耐热性的肉品发酵剂乳酸菌,通过溶钙圈法分离,乳酸纸层析、耐盐耐硝性、生物胺检测、产黏性、发酵葡萄糖产气、产H2S、抑菌实验初筛和产酸能力、耐热能力实验复筛,最终从5种传统发酵肉筛选出2株具有良好发酵特性和耐热性的菌株Y9、FL6。结合形态学、生理生化特征和16S rRNA序列分析鉴定后确定Y9为植物乳杆菌,FL6为戊糖片球菌。这两株菌都能在含6g/dL NaCl和150mg/kgNaNO2的MRS培养基中良好生长,其产酸速度快,24h内能将pH值降到4.0左右,还能抑制大肠杆菌和金黄色葡萄球菌的生长。经过水浴80℃处理1min后,发现菌株Y9、FL6活菌数依然维持在103、105CFU/mL左右,表现出较好的高温耐受力,可将两株菌复配后经喷雾干燥制成发酵剂菌粉。

Screening and Identification of Thermoduric Lactic Acid Bacteria Strains for Meat Fermentation

In order to obtain lactic acid bacteria with excellent fermentation capability and high heat resistance for meat fermentation,strains Y9 and FL6 were isolated from five types of traditional fermented meat by comparing their fermentation characteristics,i.e.dissolved calcium circle,lactate production,ability to grow at different salt and nitrite concentrations,biogenic amines detection,viscosity production,gas production from glucose,hydrogen sulfide production,inhibitory activity against pathogens,acidogenicity and heat tolerance.Based on morphological characteristics,physiological and biochemical characteristics and 16S rRNA sequence analysis,strains Y9 and FL6 were identified as Lactobacillius plantarum and Pediococcus pentosaceus,respectively.Both strains could grow well in MRS medium with 6 g/dL NaCl and 150 mg/kg NaNO2,and they also had a fast lactic acid production rate to decrease the pH to around 4.0 within 24 hours.Furthermore,both of them were able to inhibit the growth of Escherichia coli and Staphylococcus aureus.The viable counts of strain Y9 and FL6 could reach 103 CFU/mL and 105 CFU/mL respectively after 80 ℃ water bath for 1 min,which suggests good heat resistance.Thus,both strains can be formulated and processed into meat starter cultures by spray drying.