Transcriptome Differential Analysis of Chlorella sp. Cultivated with Simulated Flue Gases

Transcriptome sequencing and annotation was performed on Chlorella sp. cultivated with simulated gases (15% (v/v) CO 2 ‐air aeration) with addition of four groups of dilute gases including 1500 mL SO 2 (50 and 200 ppm) and 1500 mL NO 2 (50 and 200 ppm) correspondingly to demonstrate why the biomass and the protein increase but the content of fatty acid has a little drop with NO 2 –CO 2 ‐air aeration. Differential expressed genes analysis indicated that including 89 upregulated and 1443 downregulated unigenes in the algae when cultivated with 15% CO 2 –SO 2 (200 ppm, 1500 mL)‐air aeration and 93 upregulated and 1776 downregulated unigenes in the algae when cultivated with 15% CO 2 –NO 2 (200 ppm, 1500 mL)‐air aeration were identified. The genes involved in TCA cycle of carbon metabolic pathway were almost downregulated. The genes which encoded the three enzymes including long‐chain fatty acid CoA ligase, alcohol dehydrogenase, and aldehyde dehydrogenase (NAD + ) were upregulated 1.15, 1.00, and 1.06‐fold in N group and 1.15, 1.94, and 0.88‐fold downregulated in S group, respectively, in fatty acid degradation pathway. However, the genes involved in three enzyme including nitrate/nitrite transporter, nitrite reductase, and nitrate reductase were upregulated 4.63, 2.85, and 7.00‐folded in N group and downregulated 1.67, 1.53, and 1.65‐folded in S group, respectively, in nitrate assimilation process. © 2019 American Institute of Chemical Engineers Environ Prog, 38: e13217, 2019