Physiological Response Of Paralis Sulata To Different Phosphorus Substrates

Currently, the abundance and the ecological niche of Paralis sulata have been previously reported. However, the physiological response of P. sulata to different phosphorus substrates has been not reported. In this dissertation, the growth and phosphatase activity of the marine environment indicator species(P. sulata) under different phosphorus substrates including, KH2PO4, sodium-β-glycerophosphate(β-G-P), glucose-6-phosphate(G-6-P), lecithin(LEC) and adenosine disodium triphosphate(ATP) were investigated. In addition, extraction methods for metabolome were evaluated based on nuclear magnetic resonance(NMR) in P. sulata. Taking this outcome into the metabolomic studies of P. sulata, we intend to find out stable metabolomic biomarkers in P. sulata under different phosphorus substrates. All the findings provide important insights into physiological effects of P. sulata to different phosphorus substrates. The results of the studies are as follows. 1. Effects of different phosphorus substrates on the growth and phosphatase activity of P. sulataFive phosphorus substrates, including KH2PO4, β-G-P, G-6-P, LEC and ATP, were used to explore their effects on the growth and phosphatase activity of P. sulata. It was found that P. sulata could utilize all five phosphorus substrates to support the growth, and dissolved organic phosphorus(DOP) was better than orthophosphate for the growth of P. sulata. The changes of alkaline phosphatase(AP) activity suggested that large molecular DOP(LEC) could be utilized by phosphatase hydrolysis. Furthermore, high external phosphorus concentration would eventually cause high intracellular phosphorus in P. sulata. It was suggested that P. sulata could utilize intracellular phosphorus to sustain growth under depletion of dissolved phosphorus. 2. Evaluation of metabolome extraction strategies from P. sulataThe metabolites of P. sulata were extracted by using three solvent extraction systems and two ways of cell disruption, and then assessed with one dimensional NMR spectroscopy combined with principal components analysis(PCA). It was found that the extraction strategy of methanol/water(1:1, homogenized) was preferable for the metabolite extractio n due to its highest yield, reproducibility, ease and speed. Validation of extraction protocol will provide a reference for further detection of metabolic pathway of P. sulata. 3. A metabolomic study on the effects of different phosphorus substrates in P. sulataThe metabolites of P. sulata were extracted by using methanol/water solvent extraction systems and homogenate cell disruption, and then analyzed with one dimensional proton NMR spectroscopy combined with Orthogonally-Partial Least Squares-Discriminant Analysis(O-PLS-DA). Metabolomics study revealed that P. sulata had significant differences between metabolic pathways on uptake and utilization different phosphorus substrates. The metabolites between LEC and KH2PO4 group were not significantly different; however, the metabolites of other treatment group had obvious difference compared with KH2PO4 group. Metabolic responses demonstrated that lactate was the difference metabolite of β-G-P treatment; glucose could be used as the difference metabolite of G-6-P treatment, while glycogen, tyrosine, histidine, and phenylalanines were the difference metabolite of ATP treatment in P. sulata. These findings provide important insights into physiological effects of P. sulata to different phosphorus substrates at molecular level using metabolomics.