UMR INRA Secalim, ENITIAA ENVN, Rue de la Géraudière, BP 82225, 44322 Nantes, Cedex 03, France.
Anaerobe. 2011 Feb;17(1):23-31. doi: 10.1016/j.anaerobe.2010.01.004. Epub 2010 Feb 10.
Strain R1333, isolated from commercially available smoked salmon, was identified as Lactobacillus sakei based on biochemical tests, sugar fermentation reactions (API 50 CHL), PCR with species-specific primers and sequencing of the 16S rRNA gene. Strain R1333 produces a 3811 kDa class IIa bacteriocin, active against Streptococcus caprinus, Streptococcus macedonicus, Streptococcus spp., L. sakei, Lactococcus lactis subsp. lactis, Listeria innocua, Listeria ivanovii subsp. ivanovii and Listeria monocytogenes. The mode of activity against L. innocua 2030C and L. ivanovii subsp. ivanovii ATCC 19119 was bactericidal, resulting in cell lysis and enzyme- and DNA-leakage. The highest level of activity (1600 AU/mL) was recorded when cells were grown at 30°C in MRS broth (initial pH 6.5). Only 800 AU/mL was recorded when strain R1333 was grown in MRS without Tween 80. Lower levels of bacteriocin production were recorded when strain R1333 was grown in MRS at 20°C. Peptide R1333 adsorbs at low levels (200 AU/mL) to producer cells. Purification of bacteriocin R1333 was performed by 60% ammonium sulfate precipitation, followed by separation on a SepPak C(18) column and reverse-phase HPLC on a Nucleosil C(18) column with a linear gradient from 0.1% TFA to 90% acetonitryl. A molecular mass of 3811 kDa was determined by mass spectrometry. Based on mass spectrometry and sequencing of the PCR amplified fragment targeting the sakG gene, L. sakei R1333 is a potential producer of sakacin G. This is the first report of the identification of sakacin G produced by L. sakei isolated from smoked salmon.
从市售熏三文鱼中分离得到的菌株 R1333，根据生化试验、糖发酵反应（API 50 CHL）、种特异性引物的 PCR 和 16S rRNA 基因测序鉴定为 sakei 乳杆菌。菌株 R1333 产生一种 3811 kDa 的 IIa 类细菌素，对肠球菌、马氏乳球菌、乳球菌、sakei 乳杆菌、乳球菌 lactis subsp. lactis、无害李斯特菌、李斯特菌 ivanovii subsp. ivanovii 和李斯特菌 monocytogenes 具有活性。对 L. innocua 2030C 和 L. ivanovii subsp. ivanovii ATCC 19119 的作用模式为杀菌作用，导致细胞裂解和酶及 DNA 泄漏。当细胞在 MRS 肉汤（初始 pH 6.5）中于 30°C 生长时，记录到最高活性（1600 AU/mL）。当菌株 R1333 在不含 Tween 80 的 MRS 中生长时，仅记录到 800 AU/mL。当菌株 R1333 在 20°C 的 MRS 中生长时，细菌素的产量较低。肽 R1333 以低水平（200 AU/mL）吸附在产细菌素细胞上。细菌素 R1333 的纯化通过 60%硫酸铵沉淀进行，然后在 SepPak C(18)柱上分离，在 Nucleosil C(18)柱上进行反相 HPLC，线性梯度从 0.1%TFA 到 90%乙腈。通过质谱法确定分子量为 3811 kDa。基于针对 sakG 基因的 PCR 扩增片段的质谱和测序，L. sakei R1333 是 sakacin G 的潜在生产者。这是首次报道从熏三文鱼中分离的 sakei 乳杆菌产生 sakacin G。
