Effect Of Carbon Sources On The Transformation Of Intracellular Substances Of Phosphorus Accumulating Organisms And Spectral Analysis

The transformation of intracellular substances of phosphorus accumulating organisms?PAOs?under different carbon sources is closely related to the function of phosphorus removal.Study the effects of different carbon sources on the transformation of intracellular substances in PAOs and the intrinsic relationship between carbon source and phosphorus removal function.It is of great significance to help reveal the microscopic mechanism of biological phosphorus removal.Real-time detection of intracellular substances is an important way to grasp the pros and cons of PAOs in time.However,the traditional method for detecting intracellular substances is complicated and takes a long time to extract.Many reagents are harmful to the human body and pollute the environment.The spectroscopy method has no pollution,it is no necessary to carry out more complicated pretreatment of the sample,and is quick and convenient.The rapid detection of intracellular substances by spectroscopy is of great significance for timely analysis of the metabolism of PAOs.However,there are relatively few studies on the effects of different carbon sources on the transformation of intracellular substances of pure PAOs and the spectral analysis of intracellular substances.The study used the laboratory-selected Acinetobacte sp.to study the effects of different carbon sources?Sodium acetate,sodium propionate,glucose,lactic acid?on the transformation of intracellular substance of PAOs by changing the carbon source.Qualitative and quantitative analysis of intracellular material transformation by three-dimensional fluorescence spectroscopy and Raman spectroscopy.The main research results are as follows:?1?The laboratory-screened PAOs of Acinetobacte sp.was cultured in four different carbon sources but in the same carbon concentration medium to observe changes in OD600.The results showed that:the OD600 of Acinetobacte sp.in the medium with sodium acetate as the carbon source increased rapidly,and the OD600tends to be stable after 16 h.It indicates that the PAOs grow faster in 16 h and then grow more stable.The OD600 growth was slower within 16 h when glucose was used as the carbon source,and then the OD600 grew faster.It indicated that the PAOs grew faster after 16 h growth.Little change in OD600 in the medium with sodium propionate and lactic acid tends to be stable,indicating that the PAOs hardly grow.?2?Conventional chemical detection method was used to analyze the conventional indicators and intracellular substances of Acinetobacte sp.in four different carbon sources:sodium acetate,sodium propionate,glucose and lactic acid.The results of routine index analysis showed that In the anaerobic stage,the absorptionrateofCODbypolyphosphatebacteriaissodium propionate>glucose>sodium acetate>lactic acid,and the release rate of orthophosphate is sodium propionate>sodium acetate>glucose>lactic acid.In the aerobic stage,the phosphorus removal effect of PAOs under four carbon sources is sodium propionate>sodium acetate>glucose>lactic acid.The results of intracellular material analysis showed that:in the anaerobic phase,PAOs increased the yield of poly-?-hydroxybutyrate?PHB?in the four sources of sodium acetate,sodium propionate,glucose and lactic acid by 97.61%,264.33%,153.16%,117.25%,respectively.Polyphosphate?poly-P?decreased by 14.28%,15.76%,23.58%,65.53%,respectively,and glycogen decreased by 14.97%,17.20%,18.97%,25.56%,respectively.In the aerobic phase,the carbon source was sodium acetate,sodium propionate,glucose,and lactic acid,and the PHB decreased by 77.88%,93.54%,91.90%,and 59.71%,respectively.After a complete cycle,when the carbon source is sodium acetate,sodium propionate,glucose,lactic acid,the intracellular glycogen of PAOs increased by-1.52%,30.09%,18.56%,2.71%,respectively,and poly-P increased by 33.90%,60.20%,43.01%,8.10%.?3?Three-dimensional fluorescence spectroscopy and fluorescence region integration were used to transform intracellular substances in different periods of Acinetobacte sp.under four different carbon sources.The results of three-dimensional fluorescence showed that the reduction of coenzyme I?NADH?and tryptophan were found in the intracellular substances of Acinetobacte sp.under four different carbon sources in different stages.When the carbon sources were sodium acetate,sodium propionate,glucose,and lactic acid,the fluorescence peak intensity of intracellular NADH peak A of anaerobic terminal PAOs decreased by 16.59,36.64,34.34,and14.66,the intracellular NADH fluorescence intensity of aerobic terminal PAOs increased by 37.73,73.88,41.94,and 16.43,respectively.In the anaerobic phase,when the carbon source is glucose,the fluorescence intensity of intracellular tryptophan in the PAOs is enhanced,and the other carbon sources are reduced.In the aerobic stage,the intracellular tryptophan fluorescence intensity of polyphosphates in the four carbon sources decreased.In the aerobic stage,the intracellular tryptophan fluorescence intensity of PAOs organisms in the four carbon sources decreased.Integrate the spectral intensity of each region by fluorescence region integration method.The results show that the fluorescence intensity of the standard volume in the fluorescence region is the same as that in the region corresponding to each substance.The fluorescence intensity is weakened,and the standard volume of the fluorescence region in the corresponding fluorescence region is also reduced.The fluorescence intensity is increased and the standard volume of the fluorescence region is also increased.A linear relationship between the NADH concentration of the standard sample and the three-dimensional fluorescence intensity is y=8.629x+58.061,When Acinetobacte sp.is used as a carbon source with sodium acetate,sodium propionate,glucose and lactic acid,The concentration of NADH in the anaerobic phase decreased by 1.92 mmol/L,4.25 mmol/L,3.98 mmol/L,and 0 mmol/L,respectively.The concentration of NADH in the aerobic phase increased by 4.37 mmol/L,8.56 mmol/L,4.86 mmol/L,and 0 mmol/L,respectively.?4?The change of intracellular substance of Acinetobacte sp.was characterized by Raman spectrophotometry.The results show that the Raman spectral intensity is a better characterization of the changes of intracellular glycogen,poly-P and PHB in different stages of PAOs under four carbon sources.Among the four carbon sources of sodium acetate,sodium propionate,glucose,and lactic acid,in anaerobic stage,the intracellular glycogen Raman intensity of PAOs was weakened by 3.62,19.13,24.31and 2.47,respectively.The Raman intensity of poly-P was weakened by 21.73,145.22,170.65 and 15.20,respectively.The PHB Raman intensity increased by 52.55,66.07,64.96,24.79.in aerobic phase,The intracellular glycogen Raman intensity of PAOs increased by 4.02,32.43,48.62,13.56,respectively.The poly-P Raman intensity increased by 50.10,257.58,240.17,38.01,respectively,and the PHB Raman intensity decreased by 122.61,141.20,110.64,54.39,respectively.?5?Raman spectroscopy combined with synergy interval partial least squares?siPLS?model was used to quantitatively analyze the intracellular substances of Acinetobacte sp.PAOs.Raman spectroscopy combined with siPLS model was used to establish quantitative analysis models for intracellular substances PHB,poly-P and glycogen of Acinetobacte sp..The results of the quantitative analysis model showed that the predicted correlation coefficients of the PHB,poly-P and glycogen models were 0.8685,0.9365 and 0.8972,respectively.The predicted root mean square error?RMSECV?were 0.3642,0.6979 and 6.2803,respectively.The verified correlation coefficients of r_p were 0.9364,0.8931 and 0.9253,and the verified root mean square error?RMSEP?were 0.1306,0.9696 and 5.8980,respectively.The optimal combination interval of PHB siPLS model is 470-555 cm^-1,755-840 cm^-1,1320-1405cm^-1,1745-1830 cm^-1,and the optimal combination interval of poly-P siPLS model is385-470 cm^-1,640-725 cm^-1,1150-1235 cm^-1,optimal interval of glycogen siPLS model is 413.33-526.67 cm^-1,753.33-866.67 cm^-1,1320-1433.33 cm^-1,1886.67-2000cm^-1.The experimental study analyzed the effect of carbon source on the transformation of intracellular substance of a single genus PAOs.Rapid qualitative analysis of intracellular substances using spectroscopy,Raman spectroscopy combined with siPLS model for quantitative analysis of intracellular substances PHB,poly-P,glycogen,Enriched the research theory of carbon source on a single genus of PAOs,It also provides a technical basis for the rapid detection of intracellular substances by the spectrum.