Composition Of Extracellular Polymeric Substances Research Articles

Stress Response of Vibrio parahaemolyticus and Listeria monocytogenes Biofilms to Different Modified Atmospheres.

The sessile biofilms of Vibrio parahaemolyticus and Listeria monocytogenes have increasingly become a critical threat in seafood safety. This study aimed to evaluate the effects of modified atmospheres on the formation ability of V. parahaemolyticus and L. monocytogenes biofilms. The stress responses of bacterial biofilm formation to modified atmospheres including anaerobiosis (20% carbon dioxide, 80% nitrogen), micro-aerobiosis (20% oxygen, 80% nitrogen), and aerobiosis (60% oxygen, 40% nitrogen) were illuminated by determining the live cells, chemical composition analysis, textural parameter changes, expression of regulatory genes, etc. Results showed that the biofilm formation ability of V. parahaemolyticus was efficiently decreased, supported by the fact that the modified atmospheres significantly reduced the key chemical composition [extracellular DNA (eDNA) and extracellular proteins] of the extracellular polymeric substance (EPS) and negatively altered the textural parameters (biovolume, thickness, and bio-roughness) of biofilms during the physiological conversion from anaerobiosis to aerobiosis, while the modified atmosphere treatment increased the key chemical composition of EPS and the textural parameters of L. monocytogenes biofilms from anaerobiosis to aerobiosis. Meanwhile, the expression of biofilm formation genes (luxS, aphA, mshA, oxyR, and opaR), EPS production genes (cpsA, cpsC, and cpsR), and virulence genes (vopS, vopD1, vcrD1, vopP2β, and vcrD2β) of V. parahaemolyticus was downregulated. For the L. monocytogenes cells, the expression of biofilm formation genes (flgA, flgU, and degU), EPS production genes (Imo2554, Imo2504, inlA, rmlB), and virulence genes (vopS, vopD1, vcrD1, vopP2β, and vcrD2β) was upregulated during the physiological conversion. All these results indicated that the modified atmospheres possessed significantly different regulation on the biofilm formation of Gram-negative V. parahaemolyticus and Gram-positive L. monocytogenes, which will provide a novel insight to unlock the efficient control of Gram-negative and Gram-positive bacteria in modified-atmosphere packaged food.

Fate and role of fluorescence moieties in extracellular polymeric substances during biological wastewater treatment: A review

In biological wastewater treatment systems, extracellular polymeric substances (EPS) are continuously excreted as a response to environmental changes and substrate conditions. It could severely affect the treatment efficacy such as membrane fouling, dewaterability and the formation of carcinogenic disinfection by-products (DBPs). The heterogeneous dissolved organic matter (DOM) with varying size and chemical nature constitute a primary proportion of EPS. In the last few decades, fluorescence spectroscopy has received increasing attention for characterizing these organic substances due to the attractive features of this low-cost spectroscopic approach, including easy sample handling, rapid, non-destructive and highly sensitive nature. In this review, we summarize the application of fluorescence spectroscopy for characterizing EPS and provide the potential implications for online monitoring of water quality along with its limitations. We also link the dynamics of fluorescent dissolved organic matter (FDOM) in EPS with operational and environmental changes in wastewater treatment systems as well as their associations with metal binding, membrane fouling, adsorption, toxicity, and dewaterability. The multiple modes of exploration of fluorescence spectra, such as synchronous spectra with or without coupling with two-dimensional correlation spectroscopy (2D-COS), excitation-emission matrix (EEM) deconvoluted fluorescence regional integration (FRI), and parallel factor analysis (PARAFAC) are also discussed. The potential fluorescence indicators to depict the composition and bulk characteristics of EPS are also of interest. Further studies are highly recommended to expand the application of fluorescence spectroscopy paired with appropriate supplementary techniques to fully unravel the underlying mechanisms associated with EPS.

Characterization of the EPS from a thermophilic corrosive consortium

Biofilm forming microorganisms are known to contribute to the corrosion of metallic materials, as they can attach to surfaces and influence the electrochemical behavior. Extracellular polymeric substances (EPS) produced by these microorganisms play a major role in adhesion and resistance of the biofilm, thus also contributing to corrosion. A better understanding of the composition of EPS could help mitigate the impact of bacterial mediated corrosion. Here, a preliminary characterization of the EPS from a thermophilic consortium isolated from a corroded airplane engine is presented. Analysis revealed five different monosaccharides, with predominance of glucose and manose, but also a significant amount of rhamnose. Glycosyl linkage analysis was also performed. On the lipid fraction, three types of fatty acids were found. The predominant protein found by peptide finger printing was S-Layer protein, related to bacterial adhesion. Morphological characterization of the biofilm forming consortium was carried using confocal and scanning electron microscopy.

Mechanism of stable sewage nitrogen removal in a partial nitrification-anammox biofilm system at low temperatures: Microbial community and EPS analysis

Stable sewage nitrogen removal with nitrogen removal efficiency of 87.5 ± 2.2% was achieved in a partial nitrification-anammox (PNA) biofilm system at low temperatures (12.8–16.3 °C). High-throughput sequencing analysis indicated that the microbial community structure in the sequencing batch biofilm reactor (SBBR) remained reasonably stable. Candidatus Brocadia was the only detected anammox genus and remained stable at 0.3–0.5%. Some psychrotolerant microorganisms that could secrete cryoprotective extracellular polymeric substances (EPS), including Flavobacterium and Thermomonas, were enriched at low temperatures. This could be conducive to the stable operation of the PNA-SBBR. Moreover, according to the EPS composition and characteristics analysis, the secretion of tightly-bound EPS that bound to the cell surface containing plentiful protein was stimulated at low temperatures, further improving the system stability. Overall, the reasonably stable microbial community structure, enrichment of psychrotolerant microorganisms, and increased secretion of EPS could play important roles for stable sewage nitrogen removal at low temperatures.

An evaluation model for the deep dewatering potential of municipal sludge based on PLS regression

For constructing a new convenient and reliable system to evaluate the dewatering performance of sludge, the relationship between the water content of dewatered municipal sludge and its physicochemical properties was comprehensively investigated. Then, an evaluation and prediction model was established based on partial least squares regression (PLS), which could accurately predict the solid content of municipal sludge treated by high-pressure deep dewatering. Furthermore, the main factors affecting the sludge dewaterability were explored by the means of principal component analysis (PCA), and it was concluded that first principal component (PC1), containing most composition of extracellular polymeric substances (EPS), accounted for 53.1% of the X variation and 62.9% of information Y variation. Both protein in soluble EPS (PNS) and polysaccharide in a tightly bound EPS (PST), with the variable importance in the projection (VIP) values more than 1, were regarded as the most decisive factors to the deep dewatering performance of municipal sludge. Additionally, the validation results demonstrate the accuracy and practicability of the obtained model, specifically fit for a conditioning system for cationic polyacrylamide (CPAM) and lysozyme either separately or jointly.

Characteristic on pollutant removal and extracellular polymeric substances distribution in different periods of an up-flow biological aerated filter

The up-flow biological aerated filter (UBAF) reactor was established to explore the pollutant removal and the extracellular polymeric substances (EPS) distribution at the initial stage of biofilm, maturity of biofilm, and stable operation periods. The parallel factor (PARAFAC) model was applied to analyze the three-dimensional fluorescence characteristics of EPS. Canonical correlation analysis (CCA) was used to study the correlation between the distribution of EPS and pollutant removal. The results showed that the removal efficiency of chemical oxygen demand (COD), ammonia nitrogen (NH4+-N), and total phosphorus (TP) at the maturity of biofilm were higher than other periods, and reached to 95.68%±0.87%, 73.48%±4.32%, and 63.80%± 14.27%, respectively. The operation period had a significant correlation with EPS distribution. All of biofilm samples detected four kinds of fluorescent substance of tryptophan-like (C1), protein-like (C2), humilic acid (C3), and humic acids-like (C4). The CCA result showed that NH4+-N removal had a very significant positive correlation with EPS concentration and composition (R≥0.9261).

The Performance of Extracellular Polymeric Substance (EPS) on Stability of Aerobic Granular Sludge (AGS)

Various article which indicating the Aerobic granular sludge (AGS) instability, particularly in prolonged phase operating duration become a significant obstacle to its implementation. Generally, prolonged the operation period will lost its stability that can degrade performance effectiveness. As AGS stabilization in hydrodynamic shear force and resisting mass transfer resistance within the reactor generally defined or evaluated by microbial community, bioactivity, extracellular polymeric substance (EPS) structure and granular aspect. The aim of this research in order to illustrate the EPS formation on AGS which is preserved at 4°C in sequencing batch reactor (SBR) by sewage for eight months. The effective of granulation method and redevelopment of AGS stability by particular pressure produced with several hydrodynamic shear force and mass transfer resistance which controlled by low organic loading rate (OLR) between 0.26 and 0.81 kg CODs/m<sup>3</sup> d with 1.33 cm/s of superficial air velocity (SAV). The confocal laser scanning microscope (CLSM), Fourier transform infrared (FTIR), and energy dispersive X-ray spectrometer (EDX) were implemented to notice the evolution in composition of EPS that revealed the intermolecular interaction helped the aerobic granule stability as seed to achieved the performance of EPS on stability of AGS.

Diversity of Bacteria and Bacterial Products as Antibiofilm and Antiquorum Sensing Drugs Against Pathogenic Bacteria.

The increase in antibiotic resistance of pathogenic bacteria has led to the development of new therapeutic approaches to inhibit biofilm formation as well as interfere quorum sensing (QS) signaling systems. The QS system is a phenomenon in which pathogenic bacteria produce signaling molecules that are involved in cell to cell communication, production of virulence factors, biofilm maturation, and several other functions. In the natural environment, several non-pathogenic bacteria are present as mixed population along with pathogenic bacteria and they control the behavior of microbial community by producing secondary metabolites. Similarly, non-pathogenic bacteria also take advantages of the QS signaling molecule as a sole carbon source for their growth through catabolism with enzymes. Several enzymes are produced by bacteria which disrupt the biofilm architecture by degrading the composition of extracellular polymeric substances (EPS) such as exopolysaccharide, extracellular- DNA and protein. Thus, the interference of QS system by bacterial metabolic products and enzymatic catalysis, modification of the QS signaling molecules as well as enzymatic disruption of biofilm architecture have been considered as the alternative therapeutic approaches. This review article elaborates on the diversity of different bacterial species with respect to their metabolic products as well as enzymes and their molecular modes of action. The bacterial enzymes and metabolic products will open new and promising perspectives for the development of strategies against the pathogenic bacterial infections.

Optimizing sludge dewatering with a combined conditioner of Fenton's reagent and cationic surfactant

Enhancing sludge dewatering is of importance in reducing environmental burden and disposal costs. In this work, a cationic surfactant, cetyl trimethyl ammonium bromide (CTAB), was combined with Fenton's reagent for sludge dewatering. Results show that the Fenton-CTAB conditioning significantly promotes the sludge dewatering. Using combined techniques of response surface methodology and uniform design, dosages of Fe2+, H2O2, and CTAB for water content response were optimized to be 89, 276, and 233 mg/g dry solids (DS), respectively. The water content of sludge decreased from 79.0% to 66.8% under the optimal conditions. Compared with cationic polyacrylamide, the Fenton-CTAB system exhibited superior sludge dewatering performance. To gain insights into the mechanisms involved in sludge dewatering, the effects of Fenton-CTAB conditioning on the composition of extracellular polymeric substances (EPS) and the morphology of the sludge flocs were investigated. The decomposition of EPS into some dissolved organics and the release of proteins in tightly bound EPS facilitated the conversion of bound water to free water and further reduced the water content of sludge cake. After conditioning, morphology of sludge showed aggregation. Overall, the enhanced sludge dewatering by Fenton-CTAB treatment provides an efficient way for management of sewage sludge.

Solubilization and characterization of extracellular proteins from anammox granular sludge

Elucidating the extracellular polymeric substances (EPS) of anammox granular sludge is important for stable nitrogen removal processes in wastewater treatment. However, due to a lack of standardized methods for extraction and characterization, the composition of anammox granule EPS remains mostly unknown. In this study, alkaline (NaOH) and ionic liquid (IL) extractions were compared in terms of the proteins they extracted from different “Candidatus Brocadia” cultures. We aimed to identify structural proteins and evaluated to which extend these extraction methods bias the outcome of EPS characterization. Extraction was focussed on solubilization of the EPS matrix, and the NaOH and IL extraction recovered on average 20% and 26% of the VSS, respectively. Using two extraction methods targeting different intermolecular interactions increased the possibility of identifying structural extracellular proteins. Of the extracted proteins, ∼40% were common between the extraction methods. The high number of common abundant proteins between the extraction methods, illustrated how extraction biases can be reduced when solubility of the granular sludge is enhanced. Physicochemical analyses of the granules indicated that extracellular structural matrix proteins likely have β-sheet dominated secondary structures. These β-sheet structures were measured in EPS extracted with both methods. The high number of uncharacterized proteins and possible moonlighting proteins confounded identifying structural (i.e. β-sheet dominant) proteins. Nonetheless, new candidates for structural matrix proteins are described. Further current bottlenecks in assigning specific proteins to key extracellular functions in anammox granular sludge are discussed.

Influence of turbulent mixing on the composition of extracellular polymeric substances (EPS) and aggregate size of aerated activated sludge

The effects of turbulent mixing on the composition of extracellular polymeric substances (EPS) and aggregate size of activated sludge were investigated at varying aeration intensities (40, 80, 100, 120, 140 and 160 L h−1; representing a turbulent dissipation rate increased from 0.017 to 0.078 m2 s−3). The average aggregate size of the inoculated sludge was 48.6 μm, and reached a final average aggregate size of 120, 160, 256, 164, 139 and 102 μm, respectively, after being mixed under the aeration intensities. The content of humic acids and proteins in loosely bound and tightly bound EPS (LB-EPS and TB-EPS, respectively) first increased and then decreased with increasing aeration intensity. During the last 21 days of the experiments, the aggregate size was found positively related to the content of LB-EPS and TB-EPS, suggesting that large aggregates may decrease the dissolution rate of LB-EPS and TB-EPS. The aggregate size was negatively related to the LB-EPS content in every reactor in the time series, which suggested that increasing LB-EPS content weakened cell attachment. We found a critical turbulence intensity of 0.038 m2 s−3, below which the aggregation was limited by the turbulence available to promote the collision and adhesion between sludge cells. Increasing turbulence intensity may decrease LB-EPS, which prevents cell attachment. Turbulence intensity above the critical turbulence intensity resulted in higher shear forces that caused the breakdown of aggregates.

Effect of NaCl on nitrification performance and extracellular polymeric substance characteristic of Klebsiella sp. TN-10

Klebsiella sp. TN-10, isolated from tannery wastewater, exhibited excellent nitrification ability cultivated in media with NaCl contents ranging from 0 to 35g/L. Analysis of antioxidative enzyme activities of TN-10 stressed by NaCl showed that the stain produced more superoxide dismutase (SOD) and catalase (CAT) to fight against salt stress conditions. Moreover, the auto-aggregation index of TN-10 decreased with the increment of NaCl contents, which is consistent with results of zeta potentials. Extinction-emission matrix (EEM) and Fourier-transform infrared (FT-IR) spectrum analyses showed that the compositions of extracellular polymeric substances (EPS) by TN-10 after NaCl shock were similar. Furthermore, proteins and polysaccharides were the main components of EPS, and the contents were greatly influenced by salinity. Then, circular dichroism (CD) spectrum was used to calculate the contents of each protein secondary structure. These results provided further insights into the knowledge of nitrification characteristics, auto-aggregation performance, and EPS compositions of TN-10 during NaCl shock.

Effects of K+ salinity on the sludge activity and the microbial community structure of an A2O process

Salt ions are ubiquitous in wastewater and have significant impacts on the microbial activity and nitrogen and phosphorus removal in biological wastewater treatment processes. The effects of KCl salinity on the removal of COD, TN and PO43--P were investigated in a lab-scale A2O process. Meanwhile, the effects of K+ concentration on the composition of extracellular polymeric substances (EPS) and the microbial community structure were demonstrated. The results showed that the pollutant removal efficiencies and the bioactivity of the activated sludge decreased and the EPS content enhanced under high concentration of K+, which resulted in the deterioration of sludge compactness and settleability. The microbial diversity reduced after K+ addition and the microbial community structure was distinct between the system with (10 g L−1 and 40 g L−1) and without K+ addition. The relative abundance of Candidatus-Competibacter, Acinetobacter and Azoarcus decreased in the anoxic zone with the increase of K+ concentration, which might led to the decrease in denitrifying phosphorus removal capacity. However, the relative abundance of some genera of Firmicutes (such as Fusibacter, Acetoanaerobium, Planococcus and Exiguobacterium) increased, which was coincident with the enhanced microbial salt-tolerance capacity. Proteobacteria, Bacteroides, Chloroflexi and Firmicutes were the dominant phyla irrespective of the salinity changed, which guaranteed the removal of organic compounds, nitrogen and phosphorus in salty environment.

Characteristics of the extracellular polymeric substance composition in an up-flow biological aerated filter reactor: The impacts of different aeration rates and filter medium heights

In this study, the compositional characteristics of extracellular polymeric substances (EPS) were systematically explored to reveal their relationship with microbial community under different conditions in an up-flow biological aerated filter reactor. The aeration rates had a significant positive correlation (0.898 ≤ R ≤ 0.979) with the tightly bound (TB)-EPS contents, but basically showed an opposite trend (R < −0.631) with the loosely bound (LB)-EPS. Moreover, the filter medium heights also affected EPS distribution. The microbial biofilm produced more LB-EPS and TB-EPS to withdraw from the extreme environment. Five fluorescent substances were identified in the EPS by EEM-PARAFAC modeling; namely, two protein-like components (protein-like C1 and tryptophan-like C2) and three humic-like components (UVA marine humic-like C3, hydrophobic humic acid-like C4, and humic acid-like C5). Under different conditions, the relative abundance of Proteobacteria and Nitrospirae had a significant positive correlation with C5 and C4, respectively. These results demonstrated that microbial community distribution could affect EPS composition.

Comparison of extracellular polymeric substance (EPS) in nitrification and nitritation bioreactors

The production and composition of extracellular polymeric substances (EPS) are important parameters of bioreactor performance. This study compared the characteristics of EPS of nitritation- and nitrification-dominant processes in an integrated fixed-film activated sludge reactor. The results showed that the tightly bound-EPS (TB-EPS) were composed of polysaccharides and protein in variable ratios, while loosely bound-EPS (LB-EPS) contains almost no protein. Quartz crystal microbalance with dissipation studies demonstrated that the adsorption of TB-EPS to solid surface was stronger and less reversible as compared to the LB-EPS, which demonstrated the importance of protein in cell adhesion. Under nitritation condition, higher abundance of ammonia oxidizing bacteria was detected, and higher amide or amine like and aromatic and tryptophan protein like substances contents in TB-EPS was also observed. The other key finding is that when nitritaion was achieved, a decrease in the abundance of nitrite oxidizing bacteria and lower hydrocarbon-like substance and humic acid-like substances in the TB-EPS were observed.

Chemical composition of extracellular polymeric substances and evolution of microbial community in activated sludge exposed to ibuprofen

Ibuprofen (IBU) containing wastewater with a concentration of 1-5 mg/L was treated in an activated sludge sequencing batch reactor (SBR), for 60 days, in order to investigate the overall performance of the SBR, the parameter variations during a typical cycle, the chemical composition and content of extracellular polymeric substances (EPS) and the evolution of microbial community. The average removal efficiencies of COD, NH4+-N and TN were >85%, while >40% of the IBU was removed and the removal efficiencies of TP fluctuated around ~ 75%. The EPS content increased significantly with IBU addition (p < 0.01). Fulvic acid-like substances in the chemical composition of EPS increased during the stable operation phase. Proteobacteria associated with nitrogen removal was the dominant phylum, which can also resist IBU stress. For the denitrifying bacteria, the OTUs of both Rhodobacter and Pseudomonas increased from day 1-30 and reduced on day 60 (p < 0.01), which was opposite to the results observed for Rhodocyclaceae (phosphorus-accumulating bacteria). The OTUs of Acidovorax showed an increasing trend (p < 0.01), whereas the OTUs for Nitrospira (nitrite oxidizers) and Nitrosomonas (ammonia oxidizers) decreased significantly (p < 0.05).

Characterization of Biofilm Formed by Phenanthrene-Degrading Bacteria on Rice Root Surfaces for Reduction of PAH Contamination in Rice.

One effective method in to reduce the uptake of organic contaminants by plants is the development of a root barrier. In this study, the characterization of biofilm structure and function by phenanthrene-degrading Pseudomonas sp. JM2-gfp on rice root surfaces were carried out. Our results showed that root surfaces from three rice species, namely Liaojing401, Koshihikari, and Zhenzhuhong all present hydrophobicity and a high initial adhesion of strain JM2-gfp. Matured robust biofilm formation occurred at 48 h on the root surfaces. The biofilm exhibited cell dense aggregates and biomass embedded in the extracellular polymeric substance (EPS) matrix. EPS composition results showed that the proteins, carbohydrates, lipids and nucleic acids are produced in the biofilm, while the content varied with rice species. Under the initial concentration of phenanthrene 50 mg·L−1, the residual phenanthrene in plant roots from ‘Zhengzhuhong’, ‘Koshihikari’ and ‘Liaojing401’ with biofilm mediated were significantly decreased by 71.9%, 69.3% and 58.7%, respectively, compared to those without biofilm groups after 10 days of exposure. Thus, the biofilm colonized on roots plays an important role of degradation in order to reduce the level of phenanthrene uptake of plants. Thereby, the present work provides significant new insights into lowering the environmental risks of polycyclic aromatic hydrocarbons (PAHs) in crop products from contaminated agriculture soils.

Dewatering performance of sewage sludge under pretreatment with modified corn-core powder

The water retained inside the sludge flocs is the bottleneck for the dehydration of sewage sludge, which hindered the following treatment. In this study, corn core powder was modified (MCCP) using sodium hydroxide (NaOH) and cationic surfactant cetyltrimethylammonium bromide (CTMAB) to break the structure of extracellular polymeric substances (EPS) and cell membrane for enhancing the dewaterability of sewage sludge. The dewatering performance, the properties of the treated sludge, the composition and distribution of EPS were investigated to discuss the dewatering mechanism of sludge. Adding 20% DS (mass of dry solids in sludge) of MCCP reduced the moisture content (MC) and the specific resistance of filtration (SRF) of the sludge by 40% and 55%, respectively. Then, correlation analyses were performed between dewatering indices of sludge and sludge properties. A multiple linear regression model was established which indicated the relationship between MC and the key factors reflecting sludge dewaterability, demonstrating that larger particle size of sludge flocs and more total dissolved solids in filtrate may be propitious to reduce content of bound water in sludge.

Extracellular polymeric substances extraction and recovery from anammox granules: Evaluation of methods and protocol development

Selection of appropriate extraction methods of extracellular polymeric substances (EPSs) is crucial, affecting the yield, composition and the properties of EPSs. However, there is still a lack of standard methods for EPS extraction. In this study, seven methods were compared to extract EPS from anaerobic ammonium oxidation (anammox) granules, and the effectiveness and cell lysis of these methods were evaluated. The heating-Na2CO3 based method obtained a higher EPS yield with limited cell lysis. Proteins (PN) and polysaccharides (PS) were predominant in extractable EPSs. Particularly, PN-related substances were substantially enriched and high PN/PS ratios resulted in most methods. Different methods resulted in EPSs with a different size distribution. By analysis of Attenuated total reflectance-Fourier transform infrared spectra (ATR-FTIR), amide- and polysaccharide-associated bands were dominant. ATR-FTIR and fluorescence density of excitation-emission matrix spectra indicated EPS compositions and structures varied with the extraction methods. Moreover, the extraction/recovery protocol based on the heating-Na2CO3 method was remarkably improved, by varying heating time and using a centrifugal filter device with membrane (CFDM) to replace concentration and purification steps. Eventually, the thermal method with an extraction time of 45 mins was identified to be most effective. The application of CFDM was demonstrated as an alternative approach to concentrate and purify for EPS recovery. To our best knowledge, this is the first original study to systematically evaluate the different EPS extraction methods from anammox granules.

Enhancement of growth and paramylon production of Euglena gracilis by co-cultivation with Pseudoalteromonas sp. MEBiC 03485

This study investigated the putative effects of co-cultivation of Euglena gracilis with Pseudoalteromonas sp. MEBiC 03485 on the growth of E. gracilis and its paramylon production. The strain MEBiC 03485 had beneficial effects on the growth and paramylon contents of E. gracilis. To determine the optimal conditions for co-cultivation, the effects of algal to bacterial inoculum ratios and E. gracilis growth stages were examined. Under optimal conditions, the biomass productivity and paramylon production were increased by more than 23% and 34%, respectively. These effects were attributed to the extracellular polymeric substances (EPS) from the strain MEBiC 03485. GC–MS and HPAEC were carried out to analyze the composition of EPS. It was found that the EPS consisted of rhamnose, galactose, glucose, and mannose. These results suggest a novel approach for potentially enhancing the growth of E. gracilis as well as its paramylon production, via co-culturing with the symbiotic strain MEBiC 03485.