The Effect Of Nitric Oxide On The Growth And Development In Cyanobacteria

Synechococcus sp. PCC7002and Anabaena PCC7120are important categorys of the blue alga,and they are also important categorys of phytoplankton.They are the important part of carbon-nitrogen circulation of the world.This experiment with Synechococcus sp. PCC7002and Anabaena PCC7120as to the material,then we observe the growth situation of Synechococcus sp. PCC7002in the MA(+N) and the MA(-N) two kind of liquid media and the growth situation of Anabaena PCC7120in the MA(+N) and the MA(-N) two kind of liquid media.Test some targets such as the cell number,OD750,the chlorophyll content,as well as the endogen Nitric oxide content,and study the relationship between Nitric oxide and the growth of non-nitrogen-fixing and nitrogen-fixing algae.The experimental result indicated:because of the difference between two kind of nutrient fluid’s nitrogen sources which in the MA(+N) nutrient fluid is the nitrate,but in the MA(-N) nutrient fluid is the urea,under the same condition,Synechococcus sp. PCC7002prefers to the urea,and grows in the MA(-N) nutrient fluid more exuberantly. When having raised20days,OD750of Synechococcus sp. PCC7002raising in the niter nitrogen environment is0.781,while OD750of Synechococcus sp. PCC7002raising in the ammonia nitrogen environment is0.828.The difference is very obvious.At the same time, we obtains the Nitric oxide content of the algae growing in ammonia nitrogen environment is2.2168/g,but which is in the niter nitrogen2.097/g.For Anabaena PCC7120,because of the difference between two kind of nutrient fluid’s nitrogen sources which in the BG11nutrient fluid is the nitrate,but in the MA(-N) nutrient fluid is no nitrogen sources,under the same condit\on,Synechococcus sp. PCC7002grows in the MA(-N) nutrient fluid more exuberantly.When having raised23days,OD750of Anabaena PCC7120raising in the BG110is0.423,while OD750of Anabaena PCC7120raising in the BG11is0.376.The result of experiments expresses:a certain of the density NO to blue agla have the promote growth function.Because in the no nitrogen environment Anabaena PCC7120will grow of heterocyst which have the nitrogen fixation.Anabaena PCC7120is biology moulding board for researching heterocyst.SO we studied the relationship of heterocyst and the content of α-Ketoglutaric acid.The research discovers that joining the NO in BG11,heterocyst is to a growing speed or a growth quantity all higher than the BG110.And the content of α-Ketoglutaric acid is the positive correlation with the percentage of heterocyst.Scientist discovered that the content of α-Ketoglutaric acid is feedback of the content of nitrogen. And the research result of our laboratory has been expresses the change of NO earlier than the change of a-Ketoglutaric acid.The result of experiment elucidation that NO is signal molecule that Anabaena PCC7120apperceive to whether lacking the nitrogen,and with α-Ketoglutaric acid have the direct or indirect contact. Beacuse the particularity and mechanism of NO is ambiguity.Our experiments prove that a certain of the density NO to blue agla have the promote growth function.And NO has an advance effect for α-Ketoglutaric acid.The change of a-Ketoglutaric acid contene is direct corrflation with heterocyst,BG11+SNP:1.2886nmol、BG110:1.1733nmol、SNP:0.4706nmol、SNP+CPTIO:0.2354nmol.We just research that changed from the physiology.For expounding the mechanism about the Nitric oxide’s function from member study more concretely,this experiment has laid the foundation.