集胞藻PCC 6803高产精氨酸藻株的紫外诱变选育

精氨酸在医药和食品工业上具有广泛用途。集胞藻PCC 6803是单细胞蓝藻, 能利用工业废气(主要成分是氮氧化物NO_x)与水反应生成的硝酸盐和亚硝酸盐合成氨基酸等化合物, 因而选育高产精氨酸藻株, 不仅能提高精氨酸产量, 而且能去除工业废气中的NO_x, 具有潜在的应用前景。研究在集胞藻PCC 6803中利用紫外诱变, 筛选抗0.8 g/L D-精氨酸和抗0.2 g/L 6-氮尿嘧啶的突变株, 选育到了一株精氨酸产量显著提高的突变株#13807-111-55, 它每OD₇₃₀值细胞的胞外精氨酸产量相比出发株提高了62.3倍, 达到(0.76±0.1) mg/(L·OD₇₃₀), 总精氨酸产量相比出发株提高了6.0倍, 达到(0.82±0.08) mg/(L·OD₇₃₀)。该突变株每OD₇₃₀值细胞的胞外精氨酸产量明显高于胞内, 表明该突变藻株是精氨酸分泌型, 因而具有潜在的应用前景。

CREATION OF HIGH ARGININE PRODUCING STRAIN OF SYNECHOCYSTIS SP. PCC 6803 BY UV MUTAGENESIS

Arginine has been widely used in medicine and food industry. Synechocystis sp. PCC 6803, a unicellular cyanobacterium, synthesize amino acids and other compounds using nitrate or nitrite as the nitrogen source. In flue gases released by industrial production, NO_x (nitrogen oxides) can react with water to form nitrate and nitrite, which can be utilized by cyanobacteria. Hence, creating high arginine producing strain of Synechocystis sp. PCC 6803 has a strong application prospects, in denitrification of industrial flue gases. This study reported the successful creation of a high arginine producing strain #13807-111-55 of Synechocystis sp. PCC 6803 by 0.8 g/L D-arginine and 0.2 g/L 6-azaruacil resistant mutants with UV mutagenesis. Compared with the parent strain #13807, extracellular arginine production per OD₇₃₀ of #13807-111-55 increased 62.3-fold, reaching (0.76±0.1) mg/(L·OD₇₃₀). Total arginine production per OD₇₃₀ of #13807-111-55 increased about 6.0-fold, reaching (0.82±0.08) mg/(L·OD₇₃₀). Extracellular arginine production per OD₇₃₀ of the mutant was significantly higher than that of intracellular, showing that the strain was the arginine-secreting mutant with strong production potential.