The Research Of Pyrroloquinoline Quinone (PQQ) On The Effect Of Several Aquatic Creatures

Pyrroloquinoline quinine (PQQ) is the third coenzyme following nicotinamide adeninedinucleotide (NAD+) or nicotinamide adenine dinucleotide phosphate (NADP+), and flavinadenine dinucleotide (FAD) or flavin mononucleotide (FMN) in biological oxidoreduction.PQQ is not only a plant growth promoting factor but also an important nutrient for the growth,development and reproduction in the mammals. So far, the physiological functions of PQQhave been studied extensively developing both at home and abroad, but it is not clear whether itcan play a physiological role to aquatic organisms.In this paper, four species of planktonic microalgae (Chlorella pyrenoidesa，Isochrysiszhanjiangensis, Nitzschia closterium and Scenedesmus quadricanda), Daphnia magna andApostichopus japonicus were chosed as subjects to study the physiological effects due to theaddition of exogenous PQQ, including that the growth of planktonic algae and its influence onthe antioxidant capacity under H2O2stress, the growth, development and reproduction of D.magna and its anti-starvation effect, as well as the coelomic fluid immune activity of A.japonicus. The results showed that:(1) PQQ had no significant effect on the growth of four planktonic algae (p>0.05). Forthe microalgae cultured in the seawater (C. pyrenoidesa, I. zhanjiangensis, N. closterium), theirantioxidant ability was not obviously changed by PQQ under H2O2stress (p>0.05). But1000μmol/L PQQ can alleviate oxidative damage of S. quadricanda within24and48h, showing thehigher cell density than that of H2O2group (p＜0.05).(2)5μmol/L of PQQ can significantly promote the reproduction of D. magna that totalnumber of offspring increased from159.5to207.67(p＜0.05). With the increasing ofconcentration to15and25μmol/L, its effect of promotion was reduced. Compared to controlgroup, PQQ failed to affect instars number and survival time (lifespan) of D. magna (p＞0.05).However, compared to5μmol/L of PQQ group,15and25μmol/L of PQQ decreased the instarsnumber and survival time of D. magna (p＜0.05). PQQ can apparently increase theanti-starvation ability of D. magna, where the survival time increased from3d of control groupto8.33d of0.5mmol/L PQQ group (p＜0.05). Further enzyme activity detection showed that,compared to control group, protein content increased significantly with the increase ofconcentration of PQQ. In the condition of starvation, SOD and MDA activities of D. magnasignificantly declined. This trend would be more obvious due to the addition of PQQ.(3) The supplement of PQQ to the feed (0.2,1.0and2.0g/kg) can significantly increasethe phagocytic activity of coelom cells of A. japonicus to Neutral red dye solution (p <0.05). The0.2and1.0g/kg groups showed the strongest phagocytic effects, while the effect of2.0g/kg groupwas significantly lower than that of other two PQQ treatment groups (p <0.05).10μmol/L PQQof injection exerted the strongest coelomic fluid immune phagocytic activity(p <0.05). With theincrease of concentration of PQQ, phagocytosis activity dropped significantly (p <0.05).Therefore, PQQ with appropriate dose can significantly improve the immune ability of coelomcells of A. japonicus, but excessive dose could resule in the opposite effect.In conclusion, PQQ has no effects on the growth of four microalgae and anti-oxidativeability of three microalgae cultured in seawater. PQQ can enhance the reproduction of D.magna, showing the increased total number of offspring, especially in the5μmol/L treatmentgroup. However, PQQ’s overdose could affect negatively to the reproduction. PQQ cansignificantly prolong the survival time of D. magna under the starvation, especially0.5mmol/Lof PQQ. The supplement of PQQ in the feed or directly injection to the body can improve thephagocytic activity of coelom cells.