细胞壁组分在红酵母RS1高耐铝中的作用研究

红酵母RS1是从酸性油茶土壤中分离到的一株高耐铝微生物,能够忍耐高达200 mmol/L以上的铝,前期研究表明RS1高耐铝能力与细胞壁有关,但是其具体机制还不清楚。因此,本文进一步研究了细胞壁组分在RS1高耐铝中的作用,以期为RS1高耐铝的具体机制提供新信息。结果表明,高于70 mmol/L的铝对RS1生长产生抑制作用,0~70 mmol/L铝处理后细胞壁主要组分甘露糖和葡聚糖含量都没有显著改变,而细胞壁磷含量在70 mmol/L铝处理后显著升高。在高铝处理时,糖蛋白抑制剂抗生素衣霉素(tunicamycin)极大加重RS1的铝毒害。由此说明,细胞壁多糖组分含量并不对RS1高耐铝起到主要作用,细胞壁结构修饰如细胞壁磷含量响应和细胞壁N连接的糖蛋白修饰在RS1高耐铝中可能起到一定作用。

Role of Cell Wall Components in High Aluminum Tolerance of Rhodotorula taiwanensis RS1

RS1 was a high Al tolerant Rhodotorula taiwanensis strain which was isolated from the acidic oil tea soil, and our previous studies showed that cell wall played an important role in the Al tolerance of RS1. However, the exact role of cell wall in the high Al tolerance of RS1 is still not clear. The role of cell wall components in the Al tolerance of RS1 was further investigated in this paper in order to clarify the mechanism underlying the high Al tolerance of RS1. The results showed that, the growth of RS1 was severely inhibited by Al more than 70 mmol/L. The glucan and mannan contents of cell wall of RS1 did not change after Al treatment, whereas the content of phosphorus of cell wall was elevated under 70 mmol/L Al. The growth of RS1 was inhibited by Al much more after additions of cell wall metabolism inhibitor tunicamycin. In conclusion, phosphorus accumulation of cell wall and N-linked mannoproteins may play important roles in high Al tolerance of RS1.