Carbon Metabolism Of Microbial Communities Of Recirculating Aquaculture System Cultured With Anguilla Marmorata

Biolog-ECO technology is a more effective method for advanced analysis of thefunctional diversity of microbial metabolism,by the utilization from microorganisms on different single carbon source,to reflect the characteristics and diversity structure of microbial community,and the process is easy,quick and the data-rich.Using the method of Biolog-ECO,through the average well color development(AWCD),miroorganism diversity indices,principal component analysis(PCA) and cluster analysis revealed the utilization to carbon source of microbial community,then knowing the carbon metabolism of microbial communities of recirculating aquaculture system(RAS)cultured with Anguilla marmorata,providing theoretical basis for its further research.1、Carbon metabolism of microbial communities in aquaculture water,moving bed biofilm reactor and biofilter of recirculating aquaculture system cultured with Anguilla marmorataThis research reflected the microbial communities features in aquaculture water,moving bed biofilm reactor and biofilter of recirculating aquaculture system(RAS)from the carbon metabolism of microbial communities. The results showed that,AWCD of microbial communities in moving bed biofilm reactor or biofilter had no significant difference(P>0.05),but both of them were significantly higher than that in aquaculture water(P<0.05); Trend of utilization of carbon sources in different sample points:aminoacids>polymers>carbohydrates>amines>phenolic acids>carboxylic acids,micro-organisms of different sample points showed preference to amino acids,polymers and carbohydrates.The microbial communities in aquaculture water and moving bed biofilm reactor had a higher utilization for carbon sources.Microbial communities of different sample points had no significant difference(P>0.05)between Simpson index and Richness index,Shannon-Wiener index, Pielou index and Mc Intosh index of microbial communities that in moving bed biofilm reactor was significantly higher than that in aquaculture water(P<0.05). Carbon metabolism of microbial communities in different sample points of recirculating aquaculture system was investigated using Biolog-ECO plates.Through analyzing the characteristics ofIV microorganism on the carbon source metabolism can provide the theoretical basis forfurther study on the recirculating aquaculture systems.2 、 Analysis of carbon metabolism diversity characters of moving bed biofilm reactor at different process in recirculating aquaculture systems using Biolog-Eco methodTo learn the carbon metabolism of microbial communities of moving bed biofilm reactor which was adjusted to different process in recirculating aquaculture systems,and find out if microorganism had a better nitrification in moving bed biofilm reactor under the condition of energy conservation. Experiments changed the moving bed biofilm reactor to different process which were O2 、 A/O and O/A,respectively.Then,using Biolog-ECO method to analyse the characteristics of microorganism on the carbon source metabolism of moving bed biofilm reactor. The results showed that,the second section of O2 process was the best of AWCD of microbial communities cultured in different process,then was the first section of A/O process,and the first section of O/A process was the worst.The utilization degree of carbon sources of microbial communities in different process show preference to amino acids and amines, the second section of O2 process and the first section of A/O process were higher than the other process.The first section of O/A process was the highest in micro-organism diversity indices,then were the second section of O2 process and the second section of O/A process,and the first section of O2 process was the lowest.The PCA(principal component analysis) showed that contribution of PC1 of the micro-organisms in different process was 32.89%,PC2 was 25.91%,and there were 16 types of substrates in PC1 over 0.5 of load,and 14 in PC2.L-Asparagine and L-Arginine of amino acids,N-Acetyl-D-Glucosamine of carbohydrates, Tween 40 and Tween 80 of polymers,4-Hydroxy Benzoic Acid of phenolic acids and Phenylethylamine of amines were better utilized by micro-organisms.γ-Hydroxybutyric Acid of carboxylic acids,D,L-α-Glycerol Phosphate of carbohydrates and 2-Hydroxy Benzoic Acid of phenolic acids were utilized worse.This experiment through changing the work conditions of moving bed biofilm reactor to study its carbon metabolism of microbial communities,which can provide a basis for further study of recirculating aquaculture system.3、Carbon metabolism of microbial communities in moving bed biofilm reactor in different hydraulic retention time of recirculating aquaculture systemCarbon metabolism of microbial communities in different hydraulic retention time(HRT are 16.08 min,10.05 min and 7.31min) in moving bed biofilm reactor of recirculating aquaculture system is investigated using Biolog-ECO plates.By regulatingV the water velocity of recirculating aquaculture system to low HRT,medium HRT andhigh HRT in turn,we take samples in three-layer of moving bed biofilm reactor when the system is stable at three different HRT separately.The results show that,(1)AWCD of microbial communities cultured in different HRT increases with the extension of incubation time.There are no significant difference for average well color development(AWCD) of micro-organisms between high HRT and low HRT(P>0.05),both of which are significantly higher than that in medium HRT(P<0.05).(2)Trend of utilization of carbon sources in three different HRT:amino acids>polymers>carbohydrates>amines>carboxylic acids>phenolic acids.The micro-organisms of low HRT have the highest utilization to carbohydrates,polymers and amino acids;The micro-organisms of high HRT have the highest utilization to carboxylic acids, amino acids and phenolic acids;The utilization of micro-organisms to carbon sources of medium HRT is the worst among three different HRT.As a whole,micro-organisms show preference to amino acids and polymers for six categories of carbon sources,carbon sources utilization degree of micro-organisms between low HRT and high HRT are better.(3)There are significant difference for Shannon-Wiener index,Simpson index and Pielou index among three different HRT(P<0.05);There are no significant difference for Mc Intosh index and Richness index between high HRT and low HRT(P>0.05),both of which are significant much higher than that in medium HRT(P<0.05);Overall,the results show that,the highest micro-organisms diversity indices is at high HRT,the second is low HRT,and medium HRT is the lowest.(4)Combined the micro-organisms diversity indices in different HRT and water environmental factors of MBBR to analyse:both micro-organisms diversity indices and the removal rate of ammonia nitrogen and nitrite of medium HRT are much lower than high HRT and low HRT;the water environmental factors and micro-organisms diversity indices of high HRT are the highest; the water environmental factors of low HRT and medium HRT have no significant difference,but the micro-organisms diversity indices of low HRT is higher than medium HRT.(5)From the correlation analysis of 31 carbon sources utilized by micro-organisms in different hydraulic retention time,we can find that D-Xylose,L-Asparagine,Tween 80,D-Mannitol and N-Acetyl-D-Glucosamine are common utilized better by micro-organisms of three HRT;2-Hydroxy Benzoic Acid of phenolic acids were utilized worst among 31 carbon sources.(6)We can know that from correlation coefficients matrix of different carbon sources with the first two principal components, there are sixteen kinds of carbon sources determine the differentiation of the principal component one,ten kinds of carbon sources determine the differentiation of the principal component two;Glycyl-L-Glutamic Acid,i-Erythritol and α-Ketobutyric Acid are significant positively related to PC1 and PC2;D-Malic Acid is significantnegatively related to PC1 and significant positively related to PC2.This research reflects the microbial communities features in different HRT in moving bed biofilm reactor of recirculating aquaculture system from the carbon metabolism of microbial communities.In order to provide the theoretical basis of improving water treatment efficiency of biological filter and system’s efficiency,we analyse the influence of water quality parameters of different HRT for the diversity of microbial communities, which can be used as the reference of water flow rate in recirculating aquaculture system.