Transcriptomic analysis of Arthrobacter sp. CGMCC 3584 responding to dissolved oxygen for cAMP production

Arthrobacter sp. CGMCC 3584 are able to produce high yields of extracellular cyclic adenosine monophosphate (cAMP), which plays a vital role in the field of treatment of disease and animal food, during aerobic fermentation. DNA array-based transcriptional analysis of Arthrobacter cells was conducted to elucidate the higher productivity of cAMP under high oxygen supply. Results showed that 14.1% and 19.3% of the whole genome genes were up-regulated and down-regulated notably, respectively. The largest group with altered transcriptional levels belonged to the group involved in carbohydrate transport and metabolism. Other large functional groups of differentially expressed genes changed significantly included amino acid transport and metabolism, inorganic ion transport and metabolism and transcription. The agitations were set as 150 r/min and 350 r/min to construct low oxygen supply and high oxygen supply conditions, respectively, a 5-L fermenter. Samples (three biological replicates) were respectively collected at 12h, 24h, 36h and 48h under two different oxygen supply conditions for transcriptional analysis. Equal samples of each of the independent biological replicates were mixed together for DNA microarray analysis. Genes expression level ratios (high oxygen supply/low oxygen supply) ≥ 2 or ≤ 0.5 were considered to be significantly regulated.