Arthrospira sp. PCC 8005 is potentially able to produce hydrogen catalysed by hox gene–encoded bidirectional hydrogenase with the aid of hyp gene–encoded accessory proteins. In the present study, we investigated the physiological factors affecting the hoxE, hoxY, hoxH, and hypF transcription in Arthrospira sp. PCC 8005. About a 4-fold increase of biomass and chlorophyll-a content was observed in cells grown for 7 days in Zarrouk’s medium supplemented with Fe²⁺. Cells grown in N-deprived medium with added Ni²⁺ had increased H₂ production and hydrogenase activity with a maximal value of 7.24 ± 0.25 μmol H₂ mg⁻¹ Chla h⁻¹ and 0.61 ± 0.03 μmol H₂ mg⁻¹ Chla h⁻¹, respectively. RT-PCR analysis revealed that cells grown in the N-deprived medium supplemented with Fe²⁺ or Ni²⁺ increased hoxE, hoxY, and hoxH transcripts. However, the highest increase of the hoxE, hoxY, hoxH, and hypF transcripts was observed in cells grown in the S-deprived medium supplemented with a combination of Fe²⁺ and β-mercaptoethanol. These results indicated that the increased expression of hox genes in Arthrospira sp. PCC 8005 can be achieved by proper adjustment of the nutrients in the growth medium. Phylogenetic analysis revealed that the small hydrogenase subunit, HoxY sequence, from Arthrospira sp. PCC 8005 was clustered together along with other cyanobacterial HoxY which is highly related to Arthrospira platensis NIES46.

节旋藻。PCC 8005可能能够通过hyp基因编码的辅助蛋白，通过hox基因编码的双向氢化酶催化产生氢。在本研究中，我们调查影响的生理因素hoxE，hoxY，hoxH和hypF转录节旋藻。PCC8005。在添加Fe ^2+的Zarrouk培养基中生长7天的细胞中观察到生物量和叶绿素a含量增加了约4倍。在添加了Ni ^2+的贫氮培养基中生长的细胞的H ₂增加生产和氢化酶活性，最大值分别为7.24±0.25μmolH ₂ mg ^-1 Chl a h ^-1和0.61±0.03μmolH ₂ mg ^-1 Chl a h ^-1。RT-PCR分析显示，在补充有Fe ²⁺或Ni ²⁺的N缺乏培养基中生长的细胞会增加hoxE，hoxY和hoxH转录本。但是，hoxE，hoxY，hoxH和hypF的增幅最大在补充了Fe ²⁺和β-巯基乙醇的S缺乏培养基中生长的细胞中观察到转录本。这些结果表明，在节肢螺旋藻中hox基因的表达增加。PCC 8005可以通过适当调节生长培养基中的养分来实现。系统发育分析表明，小亚基氢化，HoxY序列，从节旋藻。PCC 8005与其他与蓝藻Artiesrospira platensis NIES46高度相关的蓝细菌HoxY聚集在一起。