Yamasaki-Yashiki Shino, Sawada Hiroshi, Kino-Oka Masahiro, Katakura Yoshio
Faculty of Chemistry, Materials and Bioengineering, Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680, Japan.
Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 535-0871, Japan.
Biosci Microbiota Food Health. 2017;36(1):17-25. doi: 10.12938/bmfh.BMFH-2016-015. Epub 2016 Nov 12.
Co-culture of lactic acid bacteria (LAB) and yeast induces specific responses that are not observed in pure culture. Gene expression profiles of ATCC 334 co-cultured with IFO 0216 were analyzed by DNA microarray, and the responses induced by direct contact with the yeast cells were investigated. Coating the LAB cells with recombinant DnaK, which acts as an adhesive protein between LAB and yeast cells, enhanced the ratio of adhesion of the LAB cells to the yeast cells. The signals induced by direct contact were clarified by removal of the LAB cells unbound to the yeast cells. The genes induced by direct contact with heat-inactivated yeast cells were very similar to both those induced by the intact yeast cells and those induced by a soluble mannan. The top 20 genes upregulated by direct contact with the heat-inactivated yeast cells mainly encoded proteins related to exopolysaccharide synthesis, modification of surface proteins, and transport systems. In the case of the most upregulated gene, LSEI_0669, encoding a protein that has a region homologous to polyprenyl glycosylphosphotransferase, the expression level was upregulated 7.6-, 11.0-, and 8.8-fold by the heat-inactivated yeast cells, the intact yeast cells, and the soluble mannan, respectively, whereas it was only upregulated 1.8-fold when the non-adherent LAB cells were not removed before RNA extraction. Our results indicated that the LAB responded to direct contact with the yeast cells through recognition of mannan on the surface of the yeast.
乳酸菌（LAB）与酵母的共培养会诱导出在纯培养中未观察到的特定反应。通过DNA微阵列分析了与IFO 0216共培养的ATCC 334的基因表达谱，并研究了与酵母细胞直接接触所诱导的反应。用重组DnaK包被LAB细胞，DnaK作为LAB与酵母细胞之间的粘附蛋白，提高了LAB细胞与酵母细胞的粘附比例。通过去除未与酵母细胞结合的LAB细胞，阐明了直接接触所诱导的信号。与热灭活酵母细胞直接接触所诱导的基因与完整酵母细胞和可溶性甘露聚糖所诱导的基因非常相似。与热灭活酵母细胞直接接触上调的前20个基因主要编码与胞外多糖合成、表面蛋白修饰和转运系统相关的蛋白质。在表达上调最明显的基因LSEI_0669的情况下，该基因编码一种与聚戊烯糖基磷酸转移酶具有同源区域的蛋白质，其表达水平分别被热灭活酵母细胞、完整酵母细胞和可溶性甘露聚糖上调了7.6倍、11.0倍和8.8倍，而在RNA提取前未去除非粘附性LAB细胞时，其仅上调了1.8倍。我们的结果表明，LAB通过识别酵母表面的甘露聚糖对与酵母细胞的直接接触作出反应。
