Maximum EPS Research Articles

Response and Tolerance of Cyanobacterial Exopolysaccharides to Rice Field Herbicide 2,4-D

This study aimed to check how herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) affects the production of EPS and its composition, growth, and biomass, as well as morphology in a cyanobacterial species isolated from a rice field in Meghalaya, India. Compared to the control cells, the growth of the organism measured in terms of chlorophyll concentration increased after being exposed to 10 and 20 ppm 2,4-D. However, cultures treated with 30 and 40 ppm experienced a decrease in their growth. Likewise, the biomass content of the organism experienced a minuscule increase in content upon exposure to 10 and 20 ppm 2,4-D but was compromised upon exposure to higher doses. When exposed to 10 ppm, the total EPS content, which includes the RPS and CPS content, showed a substantial increase. Maximum EPS production was seen at 20 ppm 2,4-D. However, exposure to 30 and 40 ppm 2,4-D, EPS production in the organism experienced a significant reduction, respectively. All components of EPS, such as uronic acid, neutral sugar, and proteins, individually showed an increase in 10 and 20 ppm 2, 4-D. A similar trend was seen in the organism’s bio-flocculating activity, which increased when exposed to 10 and 20 ppm, respectively. However, this activity in cells exposed to 30 and 40 ppm 2,4-D was severely reduced. Not only the content of EPS but the rate of EPS production was also enhanced in lower concentrations of 2,4-D. Although exposure to 30 ppm 2,4-D, the rate of EPS production was not significantly compromised, 40 ppm exposure adversely affected the rate of EPS production. Furthermore, visualization using scanning electron microscopy revealed the morphological changes induced by the herbicide 2,4-D.

Abstract 2008: Characterizing Changes In Abdominal Aortic Aneurysm Principal Wall Strain Using Ultrasound Elastography

Pressure-normalized aortic principal wall strain (ep+/pp, %/mmHg) is a biomechanical parameter for abdominal aortic aneurysm (AAA) stability correlated with aneurysm growth rate. We hypothesized that ep+/pp decreases as AAAs degenerate. This study aimed to characterize ep+/pp change over time using ultrasound elastography (USE). Axial ultrasound images of patient AAAs were collected at two consecutive clinic visits. The USE algorithm applied a finite element mesh over the aneurysm wall at the point of maximum diameter. A custom image-registration protocol tracked frame-to-frame displacement fields of the images over one cardiac cycle to calculate maximum ep+/pp (Fig 1). Clinical data were collected from patient records. The cohort was separated by index ep+/pp terciles. Thirty-one patients with a mean age of 71.7 ± 10.1 at index visit were included, with follow-up imaging at an interval of 7.1 ± 3.4 months. For the cohort, maximum ep+/pp decreased from 2.3 ± 1.0 %/mmHg to 2.0 ± 0.9 %/mmHg (p=0.08), and average AAA diameter increased from 4.4 ± 0.6 cm to 4.5 ± 0.7 cm (p=0.04). The “high-strain” tercile was associated with a strain reduction of -1.7 ± 0.8 %/mmHg, compared to “low” (0.1 ± 1.0 %/mmHg, p<0.01) and “intermediate” (-0.4 ± 0.5 %/mmHg, p=0.04) terciles (Fig 2). There was no difference in AAA growth or rupture between terciles. The present findings indicate that AAA ep+/pp at baseline predicts the degree of ep+/pp decrease over time. These data suggest that biomechanical changes in the aortic wall related to aneurysmal degeneration can be quantized by a novel ultrasound technique. Research correlating these results with histopathologic AAA remodeling may inform monitoring.

Heavy metal tolerance, and metal biosorption by exopolysaccharides produced by bacterial strains isolated from marine hydrothermal vents

The present study highlights heavy metal tolerance, EPS production, and biosorption capacity of four hydrothermal vent bacterial strains, namely Exiguobacterium aquaticum, Mammaliicoccus sciuri, Micrococcus luteus, and Jeotgalicoccus huakuii against As, Cd, Cr, Cu, Co, Pb and Ni. The biosorption assay showed high removal efficiency of As (83%) by E. aquaticum, Cd (95%) by M. sciuri, Cu (94%) by M. luteus, and Ni (89%) by J. huakuii and their produced EPS with these metals in aqueous solution were 84%, 85%, 98%, and 91%, respectively. The maximum EPS yield was attained by optimized medium composition consisting of 1% Xylose, and 1% NaCl at pH 7. In metal-amended conditions, the four bacterial strains showed induced EPS production in the initial concentrations. SEM with EDX and CLSM images showed that the growth and EPS production of bacterial strains were affected by metal ion concentrations. A phenol sulphuric acid method and BCA assay were used to identify both the carbohydrate and total protein content of four extracted EPS. A DPPH assay revealed that EPS influences free radical scavenging and has a highly enhanced synergistic effect with its antioxidant activity. FT-IR analysis of four extracted EPS showed the shifting of peaks in the functional groups of EPS before and after adsorption of metal ions. At pH 5 and after 60 min contact time metal removal efficiency and adsorption capacity increased as calculated for As, Cd, Cu, and Ni by four extracted EPS: (86%, 20 mg/g), (74%, 19 mg/g), (94%, 60 mg/g) and (89%, 32 mg/g) and (89%, 16 mg/g), (85%, 16 mg/g), (96%, 22 mg/g) and (91%, 16 mg/g), respectively. The Langmuir compared to the Freundlich model was found to better represent the adsorption by EPS providing maximum adsorption capacities for As (34.65 mg/g), Cd (52.88 mg/g), Cu (24.91 mg/g), and Ni (58.38 mg/g).

Maximizing the degree powers of graphs with fixed size

For a graph G with degree sequence (d1,d2,…,dn) and a positive integer p, denote the degree power of G by ep(G)=∑i=1ndip. In this paper, we concentrate on the extremal problems of degree powers in graphs with fixed size. By the majorization theory, we firstly characterize the graphs with the maximum ep(G) among all connected graphs in G(n,m) where m≤2n−3. The second main result is about the graphs with forbidden cycles. Concretely, we determine the maximum ep(G) among all Cℓ-free graphs in G(m) and characterize the corresponding extremal graphs. An analogous result is obtained in non-bipartite graphs. Furthermore, we respectively give the sharp upper bounds on ep(G) in G(m) with respect to various graph parameters, such as clique number, chromatic number, girth, and circumference.

Enhanced exopolysaccharide production by multi metal tolerant Klebsiella variicolaSMHMZ46 isolated from mines area and application in metal bioremediation.

The current study aimed to enhance exopolysaccharide production by Klebsiella variicolaSMHMZ46 isolated from the Zawar mines area in Udaipur, Rajasthan, India, by optimizing the medium with OFAT and a central composite design. The trial including sucrose (9.5%), casein hydrolysate (3%), and NaCl (0.5%) yielded the maximum EPS production as indicated by applying the CCD-RSM biostatistical program. The composition of exopolysaccharides produced by Klebsiella variicolaSMHMZ46 culture was characterized. Growth under Pb(II), Cd(II), and Ni(II) metal amended conditions induced EPS production relative to control. TLC was used for identifying the sugar residues of EPS, in addition to determination of both total carbohydrate and protein contents. According to FT-IR analysis, EPS can interact with metal ions via their functional chemical groups, thereby supporting their bioremediation potential. The metal removal efficiency of bacteria and their produced EPS in broth individually spiked with Pb(II), Ni(II), and Cd(II) was 99.18%, 97.60%, and 98.20%, respectively, and powdered EPS from contaminated water was 85.76%, 72.40%, and 71.53%, respectively. According to FEG-SEM observations, the surface morphology of EPS becomes rough, demonstrating sharp bumps after metal binding. A FEG-SEM analysis of the structure of EPS was performed; the surface structure of EPS (with metal) was more rigid than that of control EPS (without metal). The interaction between the EPS system and Pb(II) ions was investigated using FEG-SEM coupled with energy dispersive X-ray spectra, and a strong peak of C, O, and Pb elements was observed, indicating successful Pb adsorption. These findings suggest that EPS from Klebsiella variicolaSMHMZ46 has a good metal adsorbing nature and could be a promising biosorbent for metal bioremediation of contaminated water.

Dietary energy:protein ratio influences the efficiency of utilization of dietary protein by growing turkeys

ABSTRACT 1. The following experiment was designed to confirm that the efficiency of dietary protein utilisation (ep) can be reduced when the AMEn to digestible crude protein (DCP) ratio of the feed falls below a critical level. In addition, the efficiency would be improved at high DCP contents through the addition of oil or starch was determined. 2. A 14 (d trial starting at 21 d of age), using BUT 6 turkeys, was designed to measure the effects on ep of four feeds (12.1 MJ AMEn/kg) with AMEn:DCP ratios ranging from 45 to 72 MJ AMEn/kg, and two additional feeds with the same DCP as the highest protein feed, one with an AMEn:DCP ratio of 59, through the addition of canola oil, and the other with a ratio of 51 MJ/kg supplemented with both starch and oil. Twenty birds constituted each experimental unit, with two replications of each sex being used per dietary treatment. 3. Ten birds per sex were sampled at the start of the trial and a further five per pen at the end for carcass analysis. Each carcass including feathers was ground and subsampled for water, protein and lipid determination. 4. A split-line regression described ep on the four feeds unsupplemented with additional energy (R2 = 0.81) with breakpoint at 60.6 MJ AME/kg DCP, maximum ep at 0.736 g/g, and a slope of 0.017. No improvement in ep resulted from supplementing the high protein feed with oil or a mixture of oil and starch, but feed intake and protein and lipid retention increased significantly (P<0.05). The argument that insufficient energy is available to enable high protein feeds to be utilised efficiently was not corroborated by the evidence from this trial.

Disclosing Lactobacillus delbrueckii subsp. bulgaricus intraspecific diversity in exopolysaccharides production

Exopolysaccharides production by 3 ropy strains of Lactobacillus delbrueckii subsp. bulgaricus of dairy origin was evaluated in synthetic medium by combining different approaches: impedometric measurements, fluorescent microscopy and flow cytometry analyses. The evaluation of ΔE by impedometric measurement (E%max-E%40h) allowed the detection of EPS production in synthetic medium, but the differences in EPS production kinetic was highlighted by flow cytometry analysis and fluorescent microcopy. This approach enabled us to unravel the diversity in EPS synthesis and release into the laboratory medium during the growth of the strains. Our results showed that the maximum EPS production occurred after 8 h of incubation, when cells were in late exponential growth phase. Furthermore, flow cytometry analysis revealed that only part of the cell population could be identified as EPS producer or as EPS-bounded cell. Therefore, the combined approach used, allowed us to define at the same time the kinetics of EPS production and release by three strains belonging to the same species and, highlight that the production of EPS depends also on the number of EPS-producing cells within the same population. This approach could be useful for the selection of strains to be used as starter cultures in dairy products where EPS production is considered an important feature.

Detoxification of Molasses and Production of Mycelial Mass and Valuable Metabolites by Morchella Species

Edible wild ascomycetes Morchella rotunda, M. vulgaris and M. conica were cultivated in liquid static and agitated flasks of sucrose and molasses substrates with a C/N ratio of 20 and 25. The impact of four substrates on the production and quality characteristics of morels was examined. Evaluation included determination of the dry mycelial mass, intra-cellular (IPS) and extra-cellular (EPS) polysaccharides, total phenolic (TPC) and antioxidant (TAC) components, proteins, as well as the degree of phenolic content reduction and decolorization of molasses. The influence of agitation conditions was also evaluated. Results showed that substrate consumption, biomass formation and secondary metabolites production were substrate, species, and C/N ratio dependent. Among species, M. conica achieved the maximum biomass (18.16 g/L) and IPS (4.8 g/L) production and significant phenolic reduction (56.6%) and decolorization (26.7%). The maximum EPS (3.94 g/L) was noted by M. rotunda, whereas TPC (32.2 mg/g), TAC (6.0 mg/g) and cellular protein (7.6% w/w) were produced in sufficient amounts. These results strongly support the use of Morchella mushrooms as a biological detoxification agent of molasses in liquid fermentations and indicate their nutritional and medicinal value.

The influence of internal installation solutions in single-family housing on the "EP" factor in the light of the new requirements of WT 2021

The first part of the article presents the upcoming changes in the regulations regarding energy consumption by single-family housing. Current and forthcoming requirements in 2021 for building insulation and maximum EP primary energy demand factor were indicated. The second part of the paper presents the results of research aimed at determining what type of heat source for heating purposes and the type of ventilation will be able to meet the latest requirements. The analysis was based on the determination and comparison of the EP factor in the considered single-family building for selected heating variants assuming two different types of ventilation: gravitational and mechanical supply-exhaust with heat recovery system. Based on the results obtained, an attempt was made to determine the tendency of changes in the design of single-family buildings in terms of choosing the type of heating and ventilation.

Exopolysaccharide production potential of different strains of Lactobacillus plantarum

In the present study, the exopolysaccharide production potential of different strains of Lb. plantarum was investigated. Six different strains of Lb. plantarum were screened for their ability to produce EPS and the growth conditions were optimized for maximum EPS production. For this different strains of Lactobacillus plantarum were grown on MRS broth supplemented with carbon sources (glucose, sucrose) and nitrogen sources (yeast extract and beef extract) at three different levels for maximum EPS production. Sucrose (15g\L) was found to be the best source of carbon for maximum EPS production in strains NCDC 373 (50.87±7.67 mg/L) and NCDC 377 (54.50±1.27 mg\L). In NCDC 382 and UBLP-40, maximum EPS yield (88.48±3.55 and 84.41±3.24 mg\L) were obtained with 25g\L of sucrose. Beef extract acted as the best source of nitrogen for maximum EPS production in five strains (NCDC 378, NCDC 377, NCDC 382, UBLP-40, NCDC 20). FT-IR spectral analysis and prebiotic activity score of the purified EPS of Lb. plantarum strains NCDC 382 and UBLP-40 revealed the presence of prominent polysaccharide functional groups and their prebiotic potential respectively.

Utilization of exopolysaccharide producing lactic acid bacteria for improving the quality of low fat curd

An experiment was conducted to utilize exopolysaccharide producing lactic acid bacteria for the preparation of low fat curd. Exopolysaccharide producing cultures were isolated from 25 curd samples collected from different sources. From this samples 32 EPS producing cultures were isolated. Based on morphological, biochemical and sugar utilisation tests the isolates were grouped. According to results, two were Streptococcus thermophilus. Eight of the isolates were Lactobacillus. Remaining 22 isolates were identified as Lactococcus. All the 32 EPS producing isolates showed mucoid colonies with a slimy appearance when the isolates were streaked on MRS or M17 agar with 4 per cent sucrose which indicates the capability of EPS production. Exopolysaccharides produced by different isolates were purified by ethanol precipitation method followed by dialysis and they were quantified by phenol sulphuric acid method. The maximum EPS yield was observed in two isolates of Lactococcus lactis subsp lactis with 109 mg/L and 107.4 mg/L respectively. Low fat curd was prepared from skim milk by using these two EPS producing isolates. Physico - chemical parameters and sensory quality of the low fat curd were analysed by standard methods. Statistical analysis revealed that the whey separation and curd setting time of low fat curd decreased with the use of exopolysaccharide producing isolates. There was no significant difference in fat content but an increase in total solid content of curd samples prepared by EPS producing isolates was observed. Overall sensory scores were higher for low fat curd prepared with EPS producing isolates when compared to control curd prepared with non EPS producing cultures.

Potential uses of Lipopolysaccharide and Exopolysaccharide Isolated from Agrobacterium spp.

A gram-negative bacterium, Agrobacterium, synthesizes lipopolysaccharide and exopolysaccharide, both indispensable in establishing complex interactions with plant hosts. These polysaccharides have biocontrol applications. This study intended to determine: 1) LPS potential as insecticide; 2) EPS production capacity. LPSs obtained from Agrobacterium isolates were tested for insecticidal activity against test insects, damaging stored grains. Agrobacterial LPS elicits insect mortalities comparable to Permethrin (standard insecticide). Typical strains (At2, At3 At5, At6) incited 80% mortality of tested insects. EPS yield was quantified at regular intervals under varying physical parameters. Maximum EPS yield of 12.25 g/L was recorded for strain At1. Antibacterial activity of all isolates (before and after UV light exposure) was tested against Gram-positive and Gram-negative reference strains. Agrobacteria exposed to UV light exhibited antibacterial activity against Gram-positive reference strains. Therefore, agrobacterial LPS can be future candidate for biocontrol of insect pests in grain stocks. Moreover, agrobacteria can not only be prospective candidates for industrial scale EPS production but can also potentially help in treating infections by antibiotic resistant Gram-positive bacteria. Hence, same native isolates carry numerous benefits for the community.

The phase shift between potential and kinetic energy in human walking.

It is known that mechanical work to sustain walking is reduced, owing to a transfer of gravitational potential energy into kinetic energy, as in a pendulum. The factors affecting this transfer are unclear. In particular, the phase relationship between potential and kinetic energy curves of the center of mass is not known. In this study, we measured this relationship. The normalized time intervals α, between the maximum kinetic energy in the sagittal plane (Ek) and the minimum gravitational potential energy (Ep), and β, between the minimum Ek and the maximum Ep, were measured during walking at various speeds (0.5-2.5 m s-1). In our group of subjects, α=β at 1.6 m s-1, indicating that, at this speed, the time difference between Ep and Ek extremes is the same at the top and the bottom of the trajectory of the center of mass. It turns out that, at the same speed, the work done to lift the center of mass equals the work to accelerate it forwards, the Ep-Ek energy transfer approaches a maximum and the mass-specific external work per unit distance approaches a minimum.

Production exopolysaccharide from Kosakonia cowanii LT-1 through solid-state fermentation and its application as a plant growth promoter

Exopolysaccharide has the activity of promoting plants growth. Herein, several agro-industrial residues were used for EPS biosynthesis through solid-state fermentation (SSF) using an EPS producing stain Kosakonia cowanii LT-1. Then the influences of cane molasses powder (CMP), NaNO3 and temperature on EPS biosynthesis through SSF were studied using response surface methodology. Maximum EPS yield (41.62 mg/gds) was obtained in a mixed substrate composed of cane bagasse and broadbean seed capsule (2:1, w/w) supplemented with CMP (5.09%, w/w) and NaNO3 (4.16‰, w/w), which achieved about 30.43% cost savings for substrates. Transcriptomic analysis explained the mechanism of NaNO3 promoting EPS production. Repeated batch SSF was performed eight times with 10% substrate as the seeds of the next SSF cycle successfully. Therefore, the fermented SSF substrate containing K. cowanii LT-1 and its EPS was applied in maize growth, which could promote seed germination rate and growth vigor of maize. Hence, fermented SSF substrates would be an ideal candidate for application as a plant growth promoter in agriculture field.

Bioprospecting of exopolysaccharide-producing bacteria from different natural ecosystems for biopolymer synthesis from vinasse

BackgroundExopolysaccharides (EPSs) belong to a family of organic thickeners or alternative hydrocolloids of microbial origin. Because the chemical structure offers beneficial bioactive functions, biocompatibility and biodegradability, EPSs are used in the chemical, food, pharmaceutical, cosmetics, and packaging industries as well as in agriculture and medicine. In this study, new bacterial strains were selected on the basis of their ability to synthesize EPS from substrate containing vinasse as a nutrient source to identify the best candidate for bio-based polymer production.ResultsAmong the 99 newly identified bacterial strains isolated from different natural ecosystem, the strain Azotobacter chroococcum 76A was selected as the best biopolymer producer since it synthesized the highest concentration of EPS in all media containing vinasse. The maximum EPS concentration (44.6 ± 0.63 mg/50 mL) was observed at 24 h, corresponding to its sub-stationary growth phase (7 × 108 ± 0.29 CFU/mL). Chemical characterization of the EPS produced showed that carbohydrates representing the principal component, followed by uronic acids and proteins. Interestingly, comparing the IR spectrum of the EPS with alginate by FTIR-ATR analysis revealed an overlap of a peak identified as guluronic acid, a component of alginate.ConclusionsThe potential biotechnological capacity of A. chroococcum 76A to synthetize biopolymer from vinasse, inexpensive starting materials, represents a possible alternative to expensive disposal of agri-food waste through its transformation into high value-added products.

Production, characterization and emulsifying property of exopolysaccharide produced by marine isolate of Pseudomonas fluorescens

Abstract Most of the natural emulsifiers are obtained from pig fat and rarely from oils like palm oil and coconut oil. Hence, an attempt has been made to isolate and identify the bacteria capable of producing exopolysaccharides which can serve as good emulsifier and can be used in the preparation of safe creams and lotions. Pseudomonas fluorescens isolated from the biofilm formed on catamaran was found to synthesize 2.9 mg/ml of exopolysaccharide. Box Behnken Optimization method predicted the maximum EPS production of 2.86 mg/ml with sucrose, yeast extract, calcium chloride and casamino acid concentration of 2.5, 0.35, 0.35 and 0.75 g/l respectively. FTIR analysis of the extracted polymer showed the presence of protein which might have helped in the formation of stable emulsion. HPLC report indicated the presence glucose, fructose, galactose, rhamnose and mannose and NMR analysis confirmed the presence of glucose, galactose and mannose. The GC analysis identified palmitic, myristic and stearic acid in the EPS. The emulsification activity was almost found to be similar in hydrocarbon with fatty acid compared to hydrocarbon without fatty acid. This ability qualifies P. fluorescens as a potential candidate for bioremediation processes and the EPS produced as a substitute for synthetic emulsifiers.

Cultural optimization of a new exopolysaccharide producer “Micrococcus roseus”

The ability to produce polysaccharides is widely spread among bacteria. The usefulness of EPS molecules makes development of new strategies for improved synthesis of EPS is a necessity. A novel EPS Producer promisingly was obtained from a culture of Micrococcus roseus. In the present investigation, two screening steps for exopolysaccharide production were done using 9 strains and 7 isolates of different taxonomic bacterial groups isolated from different soil samples together with bacterial strains obtained from culture collections. The first screening for EPS-production was done on solid basal media based on the mucous aspect of colonies. The slimiest and mucous bacterial strains were again screened for EPS production in liquid cultures. Comparative data of the eleven bacterial strains showed that Micrococcus roseus proved to produce the maximum EPS in shacked culture and the maximum EPS production was amounting to 1.805 g EPS/l. An attempt was made to optimize and maximize the production of EPS by M. roseus. Maximum EPS production of 800 mg/100 ml observed after 96 h incubation at 25 °C using 4.5% and 0.02% of sucrose and ammonium sulphate concentration respectively at pH 7.0. A preliminary structural elucidation of the exopolysaccharide of M. roseus was done using spectroscopic technique FTIR and showed a characteristic band attributed to (1–3) β glucan linkage. The monomeric composition was glucose, galactose and rhamnose with two carbohydrate and protein portions 91.3% and 8.7% respectively.

Quantification of Exopolysaccharide Produced by Bacillus subtilis and the Effect of Different Factors on its Production

The present study included the extraction and characterization of EPS production by a local soil isolate Bacillus subtilis and examine the effect of different factors pH, inoculums size, incubation periods, and carbon, nitrogen and phosphate sources on EPS production. The exopolysaccharide was recovered from the culture supernatant by using a cold ethanol precipitation. The total carbohydrate content was determined by phenol sulfuric acid method at 488 nm, and major structural groups were detected by Fourier transform infrared (FTIR) spectroscopy at frequency range of 400 to 4000 cm-1. Basal salt solution (BSS) showed higher efficacy in supporting the bacteria to produce EPS (0.986 mg/ml) as dry weight. The study showed that glucose and fructose were gave maximum EPS production as a carbon source along with ammonium chloride as a nitrogen source. The optimal medium conditions were pH 7.0, inoculum size 5-6%, after four days of incubation to promote the maximum EPS production for the bacteria under study

Bioremoval of nutrients from wastewater by a denitrifier Paracoccus denitrificans ISTOD1

The introduction of plant nutrients like nitrogen and phosphorus in water bodies cause a natural ageing process called eutrophication. In the present study, 71.9% NO3−N and 93% ortho-P removal was achieved within 72h by an aerobic denitrifier P.denitrificans ISTOD1, suggesting the strain as a potential denitrifying phosphorus accumulating organism (DPAO). To make wastewater treatment cost-effective, different concentration of molasses were optimized for maximum EPS production. Application of strain ISTOD1 in real wastewater samples with 5% molasses resulted in NH4+-N, NO2−N, NO3−N, TN, COD and TP removal efficiencies of 99.6%, 79.2%, 83.8%, 97.3%, 84.2% and 100%. Moreover, 1.9g/L EPS production was also observed between late exponential- stationary phase. Assessment on wastewater demonstrated the capability of ISTOD1 in overall nutrient removal along with EPS production. Bioflocculation efficiency of the domestic wastewater produced EPS makes the strain an efficient candidate for enhanced wastewater remediation.

Composition of Extracellular and Intracellular Polymeric Substances Produced by Scenedesmus and Microcystis

Abstract Algal extracellular and intracellular polymeric substances (EPS and IPS) are widely applied in fields such as food, cosmetics, and wastewater treatment. Algal IPS content was much higher than EPS and thus extracting IPS from algal biomass may greatly improve the commercial value of algal cultivation. This study was to provide a basis for development of algal IPS by comparing composition of algal IPS and EPS. EPS and IPS produced by Scenedesmus and Microcystis, which commonly dominates the freshwater ecosystems, were analyzed using fluorescence excitation-emission matrix spectroscopy combined with parallel factor analysis (EEM-PARAFAC). The IPS concentration of Scenedesmus obliquus and Microcystis aeruginosa was 1.2 to 2.1 times higher than EPS concentration. The maximum EPS concentration was 145.7 mg C/L but the maximum IPS concentration reached 206.1 mg C/L. Seven components including five humic-like components (C1, C2, C3, C4, and C7) and two tryptophan-like component (C5 and C6) were identifie...