Enteromorpha Polysaccharides Research Articles

RETRACTION: Transcriptome Analysis Reveals Potential Mechanisms of the Effects of Dietary Enteromorpha Polysaccharides on Bursa of Fabricius in Broilers.

RETRACTION: Transcriptome Analysis Reveals Potential Mechanisms of the Effects of Dietary Enteromorpha Polysaccharides on Bursa of Fabricius in Broilers.

Effect of Enteromorpha polysaccharides on gut-lung axis in mice infected with H5N1 influenza virus

Enteromorpha polysaccharides (EPPs) have been reported to have antiviral and anti-inflammatory properties. To explore the effect of EPPs on H5N1-infected mice, mice were pretreated with EPPs before being infected with the H5N1 influenza virus intranasally. H5N1 infection resulted in body-weight loss, pulmonary and intestinal damage, and an imbalance of gut microbiota in mice. As a result of the inclusion of EPPs, the body weight of mice recovered and pathological damage to the lung and intestine was reduced. EPPs also diminished inflammation by drastically lowering the expression of proinflammatory cytokines in lungs and intestines. H5N1 infection reduced bacterial diversity, and the abundance of pathogenic bacteria such as Desulfovibrio increased. However, the beneficial bacteria Alistipes rebounded in the groups which received EPPs before the infection. The modulation of the gut-lung axis may be related to the mechanism of EPPs in antiviral and anti-inflammatory responses. EPPs have shown potential in protecting the host from the influenza A virus infection.

Reaction mechanism of syngas produced via pyrolysis of enteromorpha polysaccharides

The mechanism of gas-phase products from pyrolysis of polysaccharides from Enteromorpha prolifera (PE) is researched. The sulfated polysaccharides are the most important polysaccharides in Enteromorpha prolifera. The molecular dynamics (MD) method is used to simulate the pyrolysis process of sulfated polysaccharides of Enteromorpha prolifera. Combined with the results of the pyrolysis simulations and density functional theory (DFT), rhamnose, glucuronic acid, glucose, and xylose are used as model compounds to estimate and calculate the reaction paths of hydrogen and carbon monoxide. In addition, fixed-bed pyrolysis experiments are performed with the above four monomers. The pyrolysis simulation results show that the pyrolysis process of sulfated polysaccharides is approximately divided into three stages: low-temperature, medium-temperature, and high-temperature stages. Gas-phase products are mainly produced in the high-temperature stage, and the main components of syngas are hydrogen, methane, and carbon monoxide. The simulation and experimental results show that pyrolysis of xylose is the most likely to generate hydrogen, followed by glucose, rhamnose, and glucuronic acid. The process of producing carbon monoxide from monomers goes through reactions such as dehydration, isomerization, C-C bond breakage, and decarbonylation. Moreover, the results of fixed-bed experiments indicate that when the four monomers are pyrolyzed individually, the highest proportions of hydrogen, carbon monoxide, and methane in the gas-phase products are obtained from the pyrolysis of xylose, glucuronic acid, and rhamnose. When the four monomers are mixed and then pyrolyzed, the proportion of hydrogen and carbon monoxide in the obtained gas-phase products decreases, and the proportion of carbon dioxide increases.

Transcriptome analysis reveals potential mechanisms of the effects of dietary Enteromorpha polysaccharides on bursa of Fabricius in broilers.

The present study was conducted to evaluate the effects of dietary supplementation of Enteromorpha polysaccharides (EP) on relative organ weight of broilers, and RNA‐seq technique was used to reveal the potential molecular mechanisms of the positive effects of EP on relative organ weight. A total of 396 1‐day‐old male chicks (Arbor Acres) were randomly assigned to six dietary treatments containing EP at 0 (EP0), 1000 (EP1000), 2500 (EP2500), 4000 (EP4000), 5500 (EP5500), and 7000 (EP7000) mg/kg levels for a 35‐day feeding trial. At the end of feeding trail, six birds (one bird from each replicate cage) were randomly selected from each treatment and then slaughtered for relative organ weight analysis. The results showed that the relative weight of bursa of Fabricius were increased in the EP1000 group (p < 0.05), and then three bursa of Fabricius samples from each group (EP0 and EP1000) were randomly selected for RNA‐seq analysis. The results of RNA‐seq analysis showed that there were 20 differentially expressed genes (DEGs) between EP0 and EP1000 groups, among the DEGs, 6 genes were upregulated and 14 genes were downregulated by EP1000 supplementation (p‐adjust < 0.05). Gene ontology (GO) enrichment analysis suggested that the DEGs were mainly enriched in negative regulation of toll‐like receptor 9 signaling pathway (p‐corrected < 0.05). Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis showed that the DEGs were mainly enriched in phagosome, mitophagy‐animal, Salmonella infection, autophagy‐animal signaling pathways (p‐corrected = 0.081). Taken together, dietary EP supplementation at 1000 mg/kg level promoted the relative weight of bursa of Fabricius may be involved in improving the immune function of broilers. These findings provided a reference for further exploring the specific molecular mechanism of EP that affecting the organ development in broilers.

Effects of Enteromorpha polysaccharide dietary addition on the diversity and relative abundance of ileum flora in laying hens

This experiment explored the effects of different levels of Enteromorpha polysaccharide dietary addition on the intestinal flora structure in laying hens. A total of 300 Hy-line brown laying hens aged 280 days old were selected according to the principle of equal weight and egg production rate. Group 1 was the blank control group fed with basic diet, Group 2 was the antibiotic control group supplemented with bacitracin zinc (0.005%) and basic diet, and Groups 3–5 were the experimental groups that received 0.1%, 0.2%, and 0.4% Enteromorpha polysaccharides in their diets, respectively. Four replicates per group and 15 repeats per replicate were prepared. The pretrial period was 10 days, and the normal trial period was 42 days. The ileum contents of laying hens were collected aseptically toward the end of the test to detect the diversity and relative abundance of the flora. Results were as follows. (1) Bacterial abundance (ACE and Chao1) and diversity (Simpson and Shannon) indexes were not significantly different between the control and test groups (P > 0.05). (2) Compared with that in group 1, the relative abundance of Firmicutes in groups 4 and 5 significantly increased by 14.13% (P < 0.05) and 13.70% (P < 0.05), respectively. The relative abundance of Bacilli in group 4 was significantly increased by 11.94% (P < 0.05) and 12.86% (P < 0.05) compared with those in groups 1 and 3, respectively. The relative abundance of Lactobacillales in group 4 was significantly increased by 27.02% (P < 0.05) compared with that in group 1. The relative abundance of Lactobacillaceae in group 4 was significantly increased by 22.92% (P < 0.05) and 11.4% (P < 0.05) compared with those in groups 1 and 3, respectively. The relative abundance of Lactobacillus in groups 4 and 5 was increased by 19.75% (P < 0.05) and 18.54% (P < 0.05), respectively. ConclusionThe dietary addition of 0.2% Enteromorpha polysaccharides can remarkably increase the relative abundance of Firmicutes phylum, Bacilli class, Lactobacillales order, Lactobacillaceae family, and Lactobacillus genus in the ileum of laying hens. This effect was equivalent to the action of bacitracin zinc and had no substantial influence on the diversity of ileum flora.

Dietary Enteromorpha Polysaccharides Supplementation Improves Breast Muscle Yield and Is Associated With Modification of mRNA Transcriptome in Broiler Chickens.

The present study evaluated the effects of dietary supplementation of Enteromorpha polysaccharides (EP) on carcass traits of broilers and potential molecular mechanisms associated with it. This study used RNA-Sequencing (RNA-Seq) to detect modification in mRNA transcriptome and the cognate biological pathways affecting the carcass traits. A total of 396 one-day-old male broilers (Arbor Acres) were randomly assigned to one of six dietary treatments containing EP at 0 (CON), 1000 (EP_1000), 2500 (EP_2500), 4000 (EP_4000), 5500 (EP_5500), and 7000 (EP_7000) mg/kg levels for a 35-d feeding trial with 6 replicates/treatment. At the end of the feeding trial, six birds (one bird from each replicate cage) were randomly selected from each treatment and slaughtered for carcass traits analysis. The results showed that the dietary supplementation of EP_7000 improved the breast muscle yield (p < 0.05). Subsequently, six breast muscle samples from CON and EP_7000 groups (three samples from each group) were randomly selected for RNA-Seq analysis. Based on the RNA-Seq results, a total of 154 differentially expressed genes (DEGs) were identified (p < 0.05). Among the DEGs, 112 genes were significantly upregulated, whereas 42 genes were significantly down-regulated by EP_7000 supplementation. Gene Ontology enrichment analysis showed that the DEGs were mainly enriched in immune-related signaling pathways, macromolecule biosynthetic, DNA-templated, RNA biosynthetic, and metabolic process (p < 0.05). Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that the DEGs were enriched in signaling pathways related to viral infectious diseases and cell adhesion molecules (p < 0.05). In conclusion, dietary inclusion of EP_7000 improves the breast muscle yield, which may be involved in improving the immunity and the cell differentiation of broilers, thus promoting the muscle growth of broilers. These findings could help understand the molecular mechanisms that enhance breast muscle yield by dietary supplementation of EP in broilers.

Dietary seaweed (Enteromorpha) polysaccharides improves growth performance involved in regulation of immune responses, intestinal morphology and microbial community in banana shrimp Fenneropenaeus merguiensis

The present study was conducted to evaluate the effects of marine polysaccharides from seaweed Enteromorpha on growth performance, immune responses, intestinal morphology and microbial community in the banana shrimp Fenneropenaeus merguiensis. Two thousand and four hundred juvenile shrimps with an average body weight of 2.18 ± 0.06 g were fed for 42 d with diets containing different levels of Enteromorpha polysaccharides (EPS): 0 (control), 1, 2 and 3 g/kg as treatment groups, each of group was replicated three times with two hundred shrimps per replicate. Dietary supplementation of 1 g/kg EPS showed a consistent improvement in the final weight, weight gain, average daily gain rate (ADGR) and specific growth rate (SGR) (P < 0.05), while showed a decrease in the feed conversion ratio (FCR) of shrimp (P < 0.05). Besides, the total anti-oxidative capacity (T-AOC), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione S-transferase (GST), lysozyme (Lyz), alkaline phosphatase (ALP), and phenoloxidase (PO) activities in hemolymph were enhanced by dietary supplementation of 1 g/kg EPS (P < 0.05), while it reduced the hemolymph MDA content (P < 0.05). Shrimp fed 1 g/kg EPS supplemented diets up-regulated FmLyz, FmSOD5 and FmCLAP gene expression level of hepatopancreas and gill (P < 0.05), and also improved the intestinal FmLC2, FmLyz, FmSOD5 and FmCLAP gene expression levels (P < 0.05). In addition, shrimp fed diets containing 1 g/kg EPS increased the villus width (P < 0.05) and resulted in a higher villus surface area (P < 0.05). According to 16S rRNA sequencing results, dietary supplementation of 1 g/kg EPS tended to increase the relative abundance of Firmicutes at phylum level (P = 0.07) and decrease the relative abundance of Vibrio at genus level (P = 0.08). There was a significant positive correlation between the relative abundance of Firmicutes and mRNA expression of intestinal immune-related genes (P < 0.05). These findings revealed that dietary 1 g/kg EPS could improve growth performance, enhance nonspecific immunity and modulate intestinal function of banana shrimp F. merguiensis.

Synchronous removal of CuO nanoparticles and Cu2+ by polyaluminum chloride-Enteromorpha polysaccharides: Effect of Al species and pH

Copper oxide nanomaterials have been extensively applied and can have serious impacts when discharged into the aquatic environment, especially when complexed with humic acid (HA) to form composite contaminants. As an innovative recycled coagulant aid, Enteromorpha polysaccharides (Ep) were associated with polyaluminum chloride (PACl) (denoted as PACl-Ep) to simultaneously remove CuO nanoparticles, Cu2+ and HA in this study. The influence of different Al species coagulants (AlCl3, PAClb and PAClc) and water pH on coagulation performance, floc properties and reaction mechanisms was investigated in detail. Results showed that in the three PACl-Ep systems, PAClb-Ep gave the highest removal efficiencies for turbidity and Cu2+, and the best UV254 removal effect was reached by using PAClc-Ep. Higher contents of Alb and Alc contributed to great coagulation performance because of their stronger bridging and sweeping effects. For all the Al species coagulants, alkalescent conditions were more conducive to removing Cu and HA compared to acidic conditions. Additionally, smaller and more agminated flocs with great recovery ability were formed by PAClb-Ep and PAClc-Ep systems (bridging and enmeshment effects cooperated with the chelated reticular structure formed by the Ep and Al species). Similarly, due to the increased hydrolysis and hydroxide precipitates, flocs formed under the condition of alkalescence were smaller, denser and stronger compared with weakly acidic conditions.

Enhanced Fermentable Sugar Production from Enteromorpha Polysaccharides by the Crude Enzymes of Vibrio sp. H11

In recent years, large-scale outbreaks of the green alga Enteromorpha prolifera in China’s offshore waters have posed a serious threat. This study aimed to improve Enteromorpha polysaccharide (EP) enzymatic sugar production using the hydrolase system of Vibrio sp. H11, an EP-utilizing microbial strain. Strain H11 was found to contain 711 carbohydrate-related genes, and 259 genes belong to glycoside hydrolases that have the potential to hydrolyze EP. To maximize the capability of strain H11 to hydrolyze EP, both the culture medium and the composition were optimized. Response surface methodology analysis showed that maximal enzymatic production from strain H11 was 8.43 U/mL after 26-h incubation. When 50 g/L of EP were treated with crude H11 enzyme, the concentration of fermentation sugars increased by 36.12%. Under these conditions, the hydrolysates were capable of generating 3,217 mL/L of biogas and 6.74 g/L of biosolvents, with increases of 28.17 and 7.29%, respectively, compared to controls. The combined application of the H11 enzymatic system and anaerobic fermentation has the potential to improve the comprehensive application of EP.

Application of Enteromorpha polysaccharides as a new coagulant aid to remove silver nanoparticles: role of dosage sequence and solution pH.

Silver nanoparticles (AgNPs) in surface water cause a serious threat to the health of humans and aquatic organisms. However, it is difficult to remove AgNPs completely since they could adsorb onto the surface of humic acid (HA) and meanwhile release Ag+ into water. In this paper, Enteromorpha polysaccharides (Ep) were applied as a coagulant aid with polyaluminum chloride (PAC) to solve this problem. The influences of Ep dosage, dosing sequence and solution pH on the coagulation efficiency, kinetics and removal mechanism of AgNPs were discussed systematically. Results showed that when Ep was applied, AgNPs could be removed effectively due to charge neutralization of PAC hydrolysate and the bridging-sweeping role of Ep gel network. When Ep was added 30 s after PAC dosing, the coagulation efficiency was about 10–20% higher than that of the reverse order. Under this condition, flocs sizes achieved 450 μm when the solution pH was 6.0, which is much larger than that using Ep–PAC. Additionally, Ep showed an ability to promote the re-aggregation of broken flocs, and AgNP–HA flocs exhibited larger sizes, better shear resistance, higher recovery ability and denser structure at pH 6.0. Factorial analysis results indicated that PAC dosage had the greatest impact on HA and AgNP removal, while Ag+ removal is more sensitive to Ep dosage.

Optimization of an aqueous two-phase extraction method for the selective separation of sulfated polysaccharides from a crude natural mixture

Abstract In this study, one aqueous two-phase system (ATPS) composed of polymer and salt was employed to extract sulfated polysaccharides (sulfated dextran) to polymer-rich phase from model polysaccharides mixture (dextran and sulfated dextran), and another ATPS was employed to back-extract sulfated polysaccharides to a salt phase. This process was further applied to separate sulfated Enteromorpha polysaccharides (EPs) from crude EPs. For optimal PEG1000/(NH4)2SO4 (TLL45) ATPS, the extraction efficiencies were 93.2 ± 0.1%, 95.4 ± 2.0%, 56.3 ± 4.4% for 5, 50, 500 kDa sulfated dextran in top PEG-rich phase and were 91.9 ± 1.4%, 97.1 ± 2.9%, 95.2 ± 0.9% for 5, 50, 500 kDa dextran in bottom salt-rich phase, respectively. The 500 kDa sulfated dextran presented precipitation at the interface, and the extraction efficiency was 26.9 ± 5.7% for 500 kDa sulfated dextran in the interface. Different ATPSs composed of PEG1000 and another salt (sodium citrate, K2HPO4, sodium tartrate, etc.) were performed to back-extract sulfated polysaccharides of PEG-rich phase to another salt phase. Under the PEG1000/sodium tartrate ATPS, the best back-extraction efficiencies of 5, 50, 500 kDa sulfated dextran were 75.1 ± 4.1%, 86.1 ± 0.2% and 88.3 ± 1.6%, respectively. Crude EPs was extracted by ultrasonic/microwave-assisted extraction from Enteromorpha powder with yield of 9.5% (w/w, dry algae powder). After that, crude EPs was separated by ATPSs, and analyzed using anion exchange chromatography and FT-IR. The results of anion exchange chromatography indicated that crude EPs contained three fractions (EP-1, EP-2, EP-3). The results of crude EPs separating by ATPSs demonstrated that majority of EP-3 concentrated in top PEG-rich phase, and EP-2 in bottom salt-rich phase of PEG1000/(NH4)2SO4 ATPS. FT-IR results showed that EP-3 presented S O and C O S strength vibrations at 1254 and 848 cm−1 (SO42− group), while EP-2 had no correlative strength vibrations. These results revealed that an ATPS method was established preliminarily for sulfated polysaccharides separation from a natural polysaccharides mixture.

Application of enteromorpha polysaccharides as coagulant aid in the simultaneous removal of CuO nanoparticles and Cu2+: Effect of humic acid concentration

Humic acid (HA) influences the aggregation and stability of nanoparticles (NPs), which determine the removal performance of NPs in coagulation. Consequently, in this study, the impact of HA concentration on the simultaneous removal of CuO NPs, Cu2+, and natural organic matter (NOM) was investigated. Enteromorpha polysaccharides (Ep), as the novel recycling coagulant aid, were integrated with polyaluminum chloride (PAC) to treat composite contaminants in this coagulation process. Removal performance, floc properties, zeta potential, scanning electron microscope (SEM) images, and Fourier Transform Infrared Spectra (FT-IR) were measured and analyzed. Results showed that PAC with Ep (PAC-Ep) was more beneficial for improving removal performances than PAC alone. Further, the coagulation performance became better with the increase in HA concentration. When the HA concentration was 10 mg/L (used PAC-Ep), the removal efficiencies of CuO NPs and Cu2+ were both more than 80%; and in particular, the highest removal efficiency of turbidity was 98%. However, excessive HA (more than 10 mg/L) reduced the removal efficiency of Cu by more than 31%. Smaller and denser flocs with better recoverability were formed as the HA concentration increased. Furthermore, because of affluent functional groups, HA was easily adsorbed on the surface of NPs and combined with dissociative Cu2+, thereby forming a composite contaminant. During the coagulation process, the colloidal system was destabilized preferentially by the charge neutralization between composite contaminants and PAC. Furthermore, a chelated reticular structure was formed by the conjunction of carboxyl and hydroxyl groups (from Ep) and Al (III) species (from PAC). Flocs were further enlarged and precipitated by bridging and sweeping of this structure.

Pyrolysis mechanisms of typical seaweed polysaccharides

The pyrolysis mechanisms of typical seaweed polysaccharides were investigated using TG-MS and Py-GC/MS. It was found that Enteromorpha polysaccharides (EN) was mainly composed of glucan, xylan and glucuronide-sulfate-rhamnose, while Sargassum fusiforme (SA) mainly consisted of uronic acid, sulfate group-fucose and polysaccharide galactose. Because of the component differences, it was found that the content of oxygen-containing functional groups and inorganic oxides varies. Meanwhile, three types of sulfur-containing functional groups (sulfonyl groups, sulphates, sulfate) were observed in seaweed polysaccharide. During the pyrolysis process, SO2 was generated because of the cleavage of sulfuric acid group in 4-O-glucuronide-2 sulfate-l-rhamnose. The generation of CO2 was due to the decarboxylation of organic matter. Besides, Py-GC/MS analysis indicated that the main pyrolysis products of EN polysaccharides were furans. The pyrolysis products of SA polysaccharides were mainly ester substances. Thus, the pyrolysis mechanisms as well as the generation pathways of main products of polysaccharides pyrolysis, were revealed.

Biodegradation of Enteromorpha polysaccharides by intestinal micro-community from Siganus oramin

Micro-communities are supposed to have more potential functions of biodegradation of polysaccharides than single strain; however, the intestinal micro-communities involved in the biodegradation of Enteromorpha polysaccharides (EP) were seldom reported. In order to obtain the EP-degrading micro-community, the intestines of Siganus oramin was obtained to isolate the micro-communities, which were enriched by 0.3% of EP as the sole carbon source. A stable micro-community with EP degradative capability was achieved after seven generations of subculture, named H1. Results showed that H1 was able to degrade 75% of EP within 24 hours, and the activity of EP lyases reached 500 U mL−1 in 32 hours. With denaturing gradient gel electrophoresis (DGGE) and 16S rRNA gene clone library analysis, ten bacteria closely related to Marinomonas pontica, Microbacterium sp., Leucobacter chironomi, Cyclobacterium sp., Algoriphagus winogradskyi, Pseudoalteromonas sp. and Vibrio sp. were determined. Furthermore, compared with the DGGE bands sequence and the clone library analysis, the dominant bacteria of the EP-biodegrading micro- community were Pseudoalteromonas sp. and Vibrio sp., with the respective proportion of 38% and 46%, and they should play an important role in EP degradation together with other degrading bacteria in the micro-community H1.

Influence of Enteromorpha polysaccharides on variation of coagulation behavior, flocs properties and membrane fouling in coagulation–ultrafiltration process

Enteromorpha polysaccharides (Ep) were used as a new coagulant aid together with polyaluminum chloride (PACl) in coagulation–ultrafiltration process to purify Yellow River water. The evolution of flocs size, growth rate, strength, recoverability and fractal structure due to Ep addition were systematically studied in this paper. On this basis, membrane fouling caused by the coagulation effluents of PACl and Ep were also investigated. Results indicated that Ep addition lead to 20% increase in coagulation performance, and meanwhile generate flocs with bigger sizes, faster growth rates and higher recovery abilities. Additionally, the flocs formed by PACl presented more compact structure with a larger Df value, while much looser flocs were obtained when Ep was added. Results of ultrafiltration experiments implied that with Ep addition, membrane fouling could be significantly reduced due to large size and loosely structures of flocs in coagulation effluents. Considering both the coagulation efficiency and ultrafiltration membrane performance, 0.2mg/L Ep was determined as the optimal dosage in coagulation–ultrafiltration process in this study.

Effect of Enteromorpha polysaccharides on coagulation performance and kinetics for dye removal

The effect of Enteromorpha polysaccharides (Ep) as a new coagulant aid on coagulation performance and kinetics was investigated for synthetic dye wastewater treatment. Color removal efficiency was used to evaluate coagulation effects and meanwhile zeta potential was measured to analyze coagulation mechanism. Floc growth kinetics and re-growth characteristics were investigated by photometric dispersion analyzer (PDA) in terms of floc growth rate, size, strength and reversibility. Results showed that coagulation aid effect of Ep was notable. When Ep was used in combination with alum coagulants, the color removal could be apparently improved, and the optimal solution pH range was 6.0–8.0 for coagulation efficiency. The growth rate and average size of flocs formed by aluminum sulfate-Ep were larger than those by aluminum sulfate in steady-state after floc growth phase, and meanwhile the distribution of floc size had a wider range. In addition, the former was also stronger and had a better recoverability than the latter.

Gene Cloning and Characterization of an α-Amylase from Alteromonas macleodii B7 for Enteromorpha Polysaccharide Degradation

Enteromorpha polysaccharides (EP) extracted from green algae have displayed a wide variety of biological activities. However, their high molecular weight leads to a high viscosity and low solubility, and therefore, greatly restrains their application. To solve this problem, bacteria from the surface of Enteromorpha were screened, and an Alteromonas macleodii strain B7 was found to be able to decrease the molecular weight of EP in culture media. Proteins harvested from the supernatant of the A. macleodii B7 culture were subjected to native gel electrophoresis, and a band corresponding to the Enteromorpha polysaccharide lyase (EPL) was detected by activity staining. The enzyme identity was subsequently confirmed by MALDI-TOF/TOF mass spectrometry as the putative α-amylase reported in A. macleodii ATCC 27126. The amylase gene (amySTU) from A. macleodii B7 was cloned into Escherichia coli, resulting in highlevel expression of the recombinant enzyme with EP-degrading activity. AmySTU was found to be cold-adapted; however, its optimal enzyme activity was detected at 40°C. The α-amylase was highly stable over a broad pH range (5.5-10) with the optimal pH at 7.5-8.0. The highest enzyme activity was detected when NaCl concentration was 2%, which dropped by 50% when the NaCl concentration was increased to 16%, showing an excellent nature of halotolerance. Furthermore, the amylase activity was not significantly affected by tested surfactants or the presence of some organic solvents. Therefore, the A. macleodii strain B7 and its α-amylase can be useful in lowering EP molecular weight and in starch processing.

Study of Enteromorpha polysaccharides as a new-style coagulant aid in dye wastewater treatment

Enteromorpha is one of the common fouling green algae, which has brought serious environmental problems in past years. This study was aimed to apply it in water treatment process. Enteromorpha polysaccharides (Ep) were used as a new-style coagulant aid to assess its effect on coagulation behavior and floc characteristics. Color removal was used to evaluate coagulation effects and floc properties were investigated by Photometric Dispersion Analyzer (PDA). Results showed that when Ep was used in combination with aluminum chloride (AC), color removal could be apparently improved, and the optimal solution pH ranged 6.0–8.0. The growth rate and average size of flocs formed by AC–Ep were larger than those by AC in steady-state after floc growth phase, and meanwhile the distribution of floc size had a wider range. Besides, floc recoverability could be significantly improved when Ep was used as coagulant aid.