Desaturase genes in a psychrotolerant Nostoc sp. are constitutively expressed at low temperature

• Main Authors: Chintalapati, Suresh, Prakash, J. S. S., Singh, Ashish K., Ohtani, Shuji, Suzuki, Iwane, Murata, Norio, Shivaji, Sisinthy
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Elsevier Science 2007
• Subjects: QL Zoology; Antarctic; Antarc*
• Online Access: http://repository.ias.ac.in/64309/; http://www.sciencedirect.com/science/article/pii/S0006291X07016452

Antarctic psychrotolerant, Nostoc sp. (SO-36), when grown at 25 °C and then shifted to 10 °C, showed an increase in the tri-unsaturated fatty acid [C 18:3(9,12,15) ] at the expense of mono- [C 18:1(9) ] and di-unsaturated [C 18:2(9,12) ] fatty acids. These results indicate that the activities of the enzymes DesA and DesB are up-regulated, when cultures were grown at 10 °C or shifted to 10 °C from 25 °C. However, RT-PCR studies indicated a constitutive expression of desA, desB, desC, and desC2 genes when cultures grown at 25 °C were shifted to 10 °C. This constitutive expression of des genes is in contrast to that observed in mesophilic cyanobacteria, in which desA and desB are transcriptionally up-regulated in response to lowering of growth temperature.