D-methionine eradicates Porphyromonas gingivalis biofilms by suppressing the cyclic di-GMP level / 口腔疾病防治

Objective@#To investigate the mechanisms by which D-methionine (D-Met) eradicates Porphyromonas gingivalis biofilms by suppressing cyclic dimeric GMP (c-di-GMP) levels.@*Methods @#Cell viability, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were measured to determine the effective concentrations of D-Met, which were subsequently used in the following experiments. During the P. gingivalis biofilm formation inhibition experiment and the mature biofilm disassembly experiment, biofilm biomass, exopolysaccharide (EPS), biofilm morphology, integrity of the cell membrane, and the level of c-di-GMP were determined. @*Results @# D-Met < 40 mmol/L was biocompatible. During the biofilm formation inhibition and mature biofilm disassembly experiments, D-Met ≥ 20 mmol/L decreased the biofilm biomass and the production of EPS. SEM analysis showed that the extracellular matrix and bacterial density were drastically reduced by D-Met ≥ 20 mmol/L. TEM detection showed that 35 mmol/L D-Met ruptured the cell membrane during biofilm formation and increased the permeability of the cell membrane in the disassembly phase of mature biofilms. C-di-GMP levels decreased with increasing concentrations of D-Met in a concentration-dependent manner.@* Conclusion @# D-Met ≥ 20 mmol/L could eradicate P. gingivalis biofilms by suppressing c-di-GMP levels.

Microorganism-derived biological macromolecules for tissue engineering / 医学前沿

According to literature, certain microorganism productions mediate biological effects. However, their beneficial characteristics remain unclear. Nowadays, scientists concentrate on obtaining natural materials from live creatures as new sources to produce innovative smart biomaterials for increasing tissue reconstruction in tissue engineering and regenerative medicine. The present review aims to introduce microorganism-derived biological macromolecules, such as pullulan, alginate, dextran, curdlan, and hyaluronic acid, and their available sources for tissue engineering. Growing evidence indicates that these materials can be used as biological material in scaffolds to enhance regeneration in damaged tissues and contribute to cosmetic and dermatological applications. These natural-based materials are attractive in pharmaceutical, regenerative medicine, and biomedical applications. This study provides a detailed overview of natural-based biomaterials, their chemical and physical properties, and new directions for future research and therapeutic applications.

Toxicity of ß-(1→3, 1→6)-á´ -glucans produced by Diaporthe sp. endophytes on Metarhizium anisopliae (Metschnikoff) Sorokin assessed by conidia germination speed parameter / Toxicidade de ß- (1 → 3, 1 → 6) -á´ -glucanas produzidas por endófitos Diaporthe sp. sobre Metarhizium anisopliae (Metschnikoff) Sorokin avaliada pelo parâmetro de velocidade de germinação dos conídios

We have previously reported that ß-(1→3,1→6)-ᴅ-glucans produced by endophytes Diaporthe sp. G27-60 and G65-65 (GenBank accession codes JF766998 and JF767007, respectively) are promising anti-proliferation agents against human breast carcinoma (MCF-7) and hepatocellular carcinoma (HepG2-C3A) cells. However, the literature fails to describe the effects of Diaporthe exopolysaccharides (EPS) on eukaryotic healthy cells. The fungus Metarhiziumanisopliae has been employed as model-system to evaluate the toxicity of pharmaceutical and agricultural-interest substances, taking into account, among other parameters, the speed of conidia germination. Current study verified the effect of different concentrations of Diaporthe ß-glucans on the germination speed of M. anisopliae. Conidia were incubated with ß-glucans treatments (50, 200 and 400 µg/mL) at 28ºC, sampled during 24 h and analyzed by light microscopy. At the end of a 24-h incubation, the amount of germinated conidia reached ≈99% for controls and ranged between 97.7 and 98.6% for treatments. Bayesian analysis indicated that Diaporthe glucans had no toxicity on M. anisopliaeand the curve of germination occurred as expected for this fungal strain. Considering the validity of filamentous fungi as model-systems, results are important data on the toxicity of endophytic EPS on healthy cells and may be associated with our previous results obtained for these polymers against tumor cells.

Anteriormente, um estudo mostrou que ß-(1→3,1→6)-ᴅ-glucanas produzidas pelos endófitos Diaporthe sp. G27-60 e G65-65 (códigos de acesso no GenBank JF766998 e JF767007, respectivamente) são agentes promissores com ação antiproliferativa contra células HepG2-C3A (hepatoma humano) e MCF-7 (adenocarcinoma mamário humano). No entanto, os efeitos de exopolissacarídeos (EPS) produzidos por fungos do gênero Diaporthe em células eucarióticas sadias não estão descritos na literatura atual. O fungo Metarhiziumanisopliae tem sido utilizado como sistema-modelo para avaliar a toxicidade de substâncias de interesse farmacêutico e agronômico, considerando, entre outros parâmetros, a velocidade de germinação de conídios. O presente estudo teve como objetivo verificar os efeitos de diferentes concentrações de ß-glucanas produzidas por Diaporthe sp. sobre a velocidade de germinação de M. anisopliae. Os conídios foram incubados com os tratamentos de ß-glucanas (50, 200 e 400 µg/mL) a 28 ºC, com amostras coletadas ao longo de 24 h, e analisados por microscopia de luz. Ao final das 24 h de incubação, o total de conídios germinados nos controles foi de ≈99%, e variou entre 97,7 e 98,6% para os tratamentos. A análise bayesiana indicou que as glucanas de Diaporthe sp. não apresentaram toxicidade sobre M. anisopliae, e a curva de germinação atendeu ao esperado para essa linhagem fúngica. Considerando a validade dos fungos filamentosos como sistemas-modelo, esses resultados representam dados importantes sobre a toxicidade dos EPS de endófitos sobre células sadias e podem ser associados aos resultados anteriormente obtidos para esses polímeros em testes contra células tumorais.

In vitro evaluation of antioxidant, anticancer, and antiviral activities of exopolysaccharide from Streptomyces hirsutus NRC2018

An exopolysaccharide Exopolysaccharide (EPSNC2) produced from marine Streptomyces hirsutus NRC2018 whichwas isolated from marine sediments at North Coast, Egypt with accession number MK050544. EPSNC2 was a β-typeheteropolysaccharide contained uronic acid (72.73%) with no sulfate groups and overall average molecular weight(Mw) 4.25×105 g/mol. The monosaccharide composition was glucuronic:galacturonic:glucose:mannose:arabinosewith molar ratio 1.2:0.6:0.1:0.2:0.1, respectively. EPSNC2 was subjected to antioxidant, anticancer, and antiviralin vitro tests, showed high 1, 1-diphenyl-2-picrylhydrazyl free radical scavenging activity whereas, the maximumantioxidant activity was 95.9% at 1,500 µg/ml after 120 minutes and the IC50 value was 158.5 µg/ml. Also, EPSNC2had the ability to scavenge H2O2 and the maximum activity was 75.6% with an estimated IC50 value 501.2 µg/ml.Furthermore, EPSNC2 showed a reducing power activity as well as a metal chelating activity in a dose dependantmanner and the activity reached 98.5% at 1,000 µg/ml. EPSNC2 had a significant and specific anticancer effect onCaCo-2 cell line without any effect on other cell lines and the IC50 was estimated to be 295.1 µg/ml. Our resultsregarding the antiviral activity against Herpes Simplex virus type 1 (HSV-1), Hepatitis A virus, and Coxsackie B-4were 84.9%, 20.3%, and 45.4%, respectively at 125 µg/ml with no activity against adenovirus. Therefore, the EC50value against the enveloped virus HSV-1 was 32.4 µg/ml.

Inhibitory effect of exopolysaccharide from Rhizopus nigricans combined with oxaliplatin on dimethylhydrazine-induced colon cancer in rats and its effect on Survivin/caspase-3/caspase-7 / 中国药理学通报

Aim To study the inhibitory effect of ex-opolysaccharide from Rhizopus nigricans ( EPS) combined with oxaliplatin on colon cancer in rats and its mechanism. Methods Colon cancer model in rats was established by subcutaneous injection of 1,2-dime-thylhydrazine ( DMH). The experimental rats were randomly divided into five groups: Control group, model group, EPS group (150 mg • kg-1 ) , oxaliplatin group (10 mg • kg-1 ) and EPS + oxaliplatin group. The his-topathological changes of colon tissues in rats were observed by HE staining. The expression levels of Sur-vivin, caspase-3 and caspase-7 proteins in colon tissues were detected by Western blot and immunohisto-chemistry. Results HE staining results showed that the damage degree of colon tissues could be significantly improved in treatment groups. Compared with model group, the expression of Survivin protein in treatment groups decreased significantly, and the expression of caspase-3 and caspase-7 proteins increased ( P < 0. 05). Conclusions Both EPS and oxaliplatin inhibit colon cancer in rats, and the synergistic effect is more remarkable. Its mechanism may be through inhibiting the expression of Survivin protein and increasing the expression of caspase-3 and caspase-7 proteins, thereby promoting the apoptosis of tumor cells and inhibiting the occurrence and development of tumors.

Effect of exopolysaccharide from Trichoderma pseudokoningii on proliferation and apoptosis of human colon cancer cell line HCT116 / 中国药理学通报

;Aim To study the effect of exopolysaccharide from Trichoderma pseudokoningii (EPS) on the proliferation and apoptosis of human colon cancer cell line HCT116. Methods The proliferation of HCT116 cells treated with EPS was examined by CCK-8 assay. The effect of EPS on the clone formation of HCT116 cells was detected by crystal violet staining. Cell apoptotic rate was determined by flow cytometry. The changes of mitochondrial membrane potential were observed by JC-1. The expressions of apoptosis-related proteins Bcl-2 and Bax were analyzed by Western blot, and caspase-9, caspase-8 and caspase-3 expressions were detected by the kit. Results EPS dose- and time-dependently inhibited the proliferation of the HCT116 cells in the range of 0 -800 mg • L " 1 . With increase of EPS concentration, the colony-formation ability of HCT116 cells decreased; the proportion of apoptotic cells increased and mitochondrial membrane potential decreased; the expression of Bcl-2 protein decreased, while the expression of Bax protein increased; the ratio of Bcl-2/Bax decreased gradually; caspase-9, caspase-8 and caspase-3 activities significantly increased. Conclusions EPS can inhibit proliferation of HCT116 and induce its apoptosis by up-regulating expression of Bax, caspase-9,caspase-8, caspase-3 and down-regulating the expression of Bcl-2.

Optimization of Bifidobacterium pseudocatenulatum KAKii cultivation conditions for exopolysaccharide production by using response surface methodology

Aims@#Bifidobacteria is a non-motile, Gram-positive, strictly anaerobic and non-spore-forming bacteria that can produce exopolysaccharide (EPS). EPS is a polymer of sugars, long chained polysaccharide which have been shown to give benefit towards human health. The optimum conditions for EPS production by Bifidobacterium are still scarce. Therefore, a study was conducted to optimize the growth conditions (pH, temperature and cultivation time) for a better improvement of EPS production. @*Methodology and results@#Three Bifidobacterium strains were cultured and the highest EPS producing strain was selected for optimization. Response Surface Methodology (RSM) was used to optimize the growth conditions for a maximum EPS production. Subsequently, EPS was characterized by using FT-IR and GC-MS. Based on the result obtained, B. pseudocatenulatum KAKii had the highest EPS production compared to the other two strains namely B. pseudocatenulatum ATCC 27919 and B. animalis. Meanwhile, the optimization of the three factors towards selected strain found that EPS produced crucially depends on time of cultivation (23.59 h) other than pH (5.0) and temperature (34.75 °C). The validation showed that the predicted and experimental values were not significantly different (P > 0.05), indicating that the developed model is fitted well for the optimization. Meanwhile, FT-IR and GC-MS results showed that the EPS was composed of D-glucose, mannose, galactose, maltose and acetic acid as by-product. @*Conclusion, significance and impact of study@#This result showed that the EPS produced by B. pseudocatenulatum KAKii is from hetero-exopolysaccharide group with acetic acid as by-product made them a possible anticancer agent in future.

Effects of carbon source and additives on biomass, exopolysaccharide production and morphology of Pleurotus ostreatus in submerged cultivation

Aims@#To investigate the influence of carbon sources and additives/surfactants on the mycelium growth and exopolysaccharides (EPS) production, including the morphology during submerged cultivation of Pleurotus ostreatus in the minimal-medium as the base medium. @*Methodology and results@#Pleurotus ostreatus was cultivated in different types of carbon sources to investigate the effects of carbon sources to mycelium growth and changes of mycelium morphology which directly affects the synthesis of EPS. In addition, additives or surfactants can increase the bioavailability of less soluble substrates in the cultured medium for the mycelium growth and indirectly affects the EPS production. In this study, the cultivation of P. ostreatus in the minimal-medium by using glucose as the carbon source with the addition of lecithin at 1% (w/v) gave the highest EPS production 4.53 ± 0.30 g/L, an increase of about 89.53% when compared to the cultivation without the addition of lecithin. Addition of lecithin changes morphology of the pellets outer layer and under microscope showing a dense hyphal network surrounding the pellets with the sizes of micro pellets almost 0.5-1.5 mm which contributed to the increase of EPS production after 14 days cultivation at 26 °C @*Conclusion, significance and impact of study@#The choice of the carbon source should not only be for high productivity rate of mycelium growth and EPS production, but a cheaper alternative source should also be considered. In conclusion, high mycelium biomass and EPS production was achieved either by changes of the morphology through the type of carbon source and addition of additives such as lecithin.

Preparation and antitumor activity of sulfated exopolysaccharide from / 南方医科大学学报

OBJECTIVE@#To explore the effect of the composition ratio on substitution of sulfate group in sulfated exopolysaccharide (EPS) from and how sulfate modification affects the anti-tumor activity of EPS.@*METHODS@#We used a chlorosulfonic acid-pyridine method to modify EPS and analyzed the effect of esterification ratio on the degree of sulfate substitution using barium chloride turbidimetry. The sulfate groups binding with EPS were analyzed with infrared spectrum analysis. CCK-8 assay was used to evaluate the inhibitory effect of EPS sulfate (SEPS) on the proliferation of human colon cancer HCT 116 cells, and annexin V-FITC/PI double staining was used to assess the pro-apoptotic effect of SEPS in the cells.@*RESULTS@#The esterifying agent and EPS at the composition ratios of 1:1 and 2:1 resulted in sulfate substitution of 0.98% (SEPS-1) and 1.18% (SEPS-2), respectively, and the substitution was improved by increasing the ratio of the esterifying agent ( < 0.05). Infrared spectrum analysis showed that the S=O stretching vibration absorption peak of -OSO appeared near 1249 cm, indicating that the sulfate group combined with EPS to form sulfate. CCK-8 assay showed that SEPS-1 produced stronger inhibitory effects on the proliferation of HCT 116 cells than EPS within the concentration range of 0.02-0.10 mg/L ( < 0.05). At the concentrations of 0.04-0.08 mg/L, SEPS-2 showed a lower anti-tumor activity than SEPS-1 ( < 0.05). SEPS-1 also showed stronger pro-apoptotic effect than EPS, and as its concentration increased, SEPS-1 dose-dependently increased the ratio of early apoptotic cells and necrotic cells; the cells treated with 0.06, 0.08 and 0.10 mg/mL SEPS-1 showed early apoptotic rates of 6.38%, 11.8% and 12.5%, and late apoptotic and necrotic rates of 5.26%, 8.04% and 6.80%, respectively.@*CONCLUSIONS@#The composition ratio of the esterifying agent has a direct impact on the degree of substitution of EPS, which can be improved by increasing the ratio of the esterifying agent. Sulfate modification of EPS can enhance its antitumor activity, which, however, is not directly related with the degree of substitution.

Exopolysaccharide production from Bacillus velezensis KY471306 using statistical experimental design

Abstract Exopolysaccharide (EPS) biopolymers produced by microorganisms play a crucial role in the environment such as health and bio-nanotechnology sectors, gelling agents in food and cosmetic industries in addition to bio-flocculants in the environmental sector as they are degradable, nontoxic. This study focuses on the improvement of EPS production through manipulation of different culture and environmental conditions using response surface methodology (RSM). Plackett-Burman design indicated that; molasses, yeast extract and incubation temperature are the most effective parameters. Box-Behnken RSM indicated that; the optimum concentration for each parameter was 12% (w/v) for molasses, 6 g/L yeast extract and 30 °C for incubation temperature. The most potent bacterial isolate was identified as Bacillus velezensis KY498625. After production, EPS was extracted, purified using DEAE-cellulose, identified using Fourier transform infrared (FTIR), gel permeation chromatography (GPC) and gas chromatography-mass spectroscopy (GC-MS). The result indicated that; it has molecular weight 1.14 × 105 D consisting of glucose, mannose and galactose.

Alginate overproduction and biofilm formation by psychrotolerant Pseudomonas mandelii depend on temperature in Antarctic marine sediments

Background: In recent years, Antarctica has become a key source of biotechnological resources. Native microorganisms have developed a wide range of survival strategies to adapt to the harsh Antarctic environment, including the formation of biofilms. Alginate is the principal component of the exopolysaccharide matrix in biofilms produced by Pseudomonas, and this component is highly demanded for the production of a wide variety of commercial products. There is a constant search for efficient alginate-producing organisms. Results: In this study, a novel strain of Pseudomonas mandelii isolated from Antarctica was characterized and found to overproduce alginate compared with other good alginate producers such as Pseudomonas aeruginosa and Pseudomonas fluorescens. Alginate production and expression levels of the alginate operon were highest at 4°C. It is probable that this alginate-overproducing phenotype was the result of downregulated MucA, an anti-sigma factor of AlgU. Conclusion: Because biofilm formation is an efficient bacterial strategy to overcome stressful conditions, alginate overproduction might represent the best solution for the successful adaptation of P. mandelii to the extreme temperatures of the Antarctic. Through additional research, it is possible that this novel P. mandelii strain could become an additional source for biotechnological alginate production.

Production, characterization and biological activities of acidic exopolysaccharide from marine Bacillus amyloliquefaciens 3MS 2017

OBJECTIVE@#To evaluate in-vitro antioxidant, anti-inflammatory and antitumor abilities against human breast adenocarcinoma (MCF7) and human prostate cancer (PC3) as well as the suppressor effect of bacterial exopolysaccharide (BAEPS) on Ehrlich ascites carcinoma (EAC).@*METHODS@#In-vitro antioxidants characters of BAEPS were determined using various methods, while anti-inflammatory activity was estimated against cyclooxygenase (COX-1 and COX-2). In-vitro study, anticancer against MCF7 and PC3 were assessed by the mitochondrial dependent reduction of yellow MTT. In in-vivo study against EAC progression, mice were inoculated with EAC cells and then were orally administered BAEPS at 200 mg/kg after 24 h (equals to 0.10 of determined LD)/10 d.@*RESULTS@#BAEPS was acidic exopolysaccharide contained uronic acid (12.3%) and sulfate (22.8%) with constitution of glucose, galactose and glucuronic acid in a molar ratio 1.6:1.0:0.9, respectively, with a molecular mass of 3.76 × 10 g/mol. BAEPS appeared potent antioxidant characters as free radical scavenging, oxygen reactive species scavenging and metal chelation, while its reducing power was low. BAEPS showed selective anti-inflammatory activity against COX-2 than COX-1, COX-2 selective. BAEPS exhibited potent and selective effect to breast cell cancer MCF7, the death percentage was 65.20% with IC = 70 μg/mL and IC = 127.40 μg/mL. BAEPS decreased counted viable EAC cells and induced non-viable cells. BAEPS improved all assessed hematological parameters. These improvements were reflected in the increasing median survival time and significant increment (P < 0.05) in life span.@*CONCLUSIONS@#BAEPS has anti-tumor activity with a good margin of safety. The anti-tumor activity of BAEPS may be due to its content from sulfated groups and uronic acids and they have antioxidant and anti-inflammatory properties.

Production, characterization and biological activities of acidic exopolysaccharide from marine Bacillus amyloliquefaciens 3MS 2017

Objective To evaluate in-vitro antioxidant, anti-inflammatory and antitumor abilities against human breast adenocarcinoma (MCF7) and human prostate cancer (PC3) as well as the suppressor effect of bacterial exopolysaccharide (BAEPS) on Ehrlich ascites carcinoma (EAC). Methods In-vitro antioxidants characters of BAEPS were determined using various methods, while anti-inflammatory activity was estimated against cyclooxygenase (COX-1 and COX-2). In-vitro study, anticancer against MCF7 and PC3 were assessed by the mitochondrial dependent reduction of yellow MTT. In in-vivo study against EAC progression, mice were inoculated with EAC cells and then were orally administered BAEPS at 200 mg/kg after 24 h (equals to 0.10 of determined LD

Effect of carbon source on production, characterization and bioactivity of exopolysaccharide produced by Phellinus vaninii Ljup

ABSTRACT The effect on different three carbon source (i.e. glucose, fructose and sucrose) on production, chemical characterization and antioxidant activity of exopolysaccharide (EPS) produced by Phellinus vaninii Ljup was investigated in this study. Amongst carbon sources examined, glucose and sucrose were favorable for the mycelia growth, while the maximum EPS yield was achieved when sucrose was employed. The predominant carbohydrate compositions in EPSs identified were gluconic acid, glucose, mannose and galactose acid. Then, FT-IR spectral analysis revealed prominent characteristic groups in EPSs. EPSs molecule exist as nearly globular shape form in aqueous solution. The variation also affects antioxidant activities by investigated by using hydroxyl and DPPH radical scavenging assay. Sucrose was best carbon source from the viewpoint of antioxidant activity due to the relatively high contents of galactose in the EPS with moderate molecular weight and polydispersity.

Exopolysaccharide dispelled by calcium hydroxide with volatile vehicles related to bactericidal effect for root canal medication

ABSTRACT Objective: Enterococcus faecalis is the dominant microbial species responsible for persistent apical periodontitis with ability to deeply penetrate into the dentin. Exopolysaccharides (EPS) contribute to the pathogenicity and antibiotic resistance of E. faecalis. Our aim was to investigate the antimicrobial activity of calcium hydroxide (CH), camphorated parachlorophenol (CMCP), and chlorhexidine (CHX) against E. faecalis in dentinal tubules. Material and Methods: Decoronated single-canal human teeth and semicylindrical dentin blocks were incubated with E. faecalis for 3 weeks. Samples were randomly assigned to six medication groups for 1 week (n=10 per group): CH + 40% glycerin-water solution (1:1, wt/vol); CMCP; 2% CHX; CH + CMCP (1:1, wt/vol); CH + CMCP (2:3, wt/vol); and saline. Bacterial samples were collected and assayed for colony-forming units. After dentin blocks were split longitudinally, confocal laser scanning microscopy was used to assess the proportion of viable bacteria and EPS production in dentin. Results: CMCP exhibited the best antimicrobial activity, while CH was the least sensitive against E. faecalis (p<0.05). CHX showed similar antimicrobial properties to CH + CMCP (1:1, wt/vol) (p>0.05). CH combined with CMCP inhibited EPS synthesis by E. faecalis, which sensitized biofilms to antibacterial substances. Moreover, increasing concentrations of CMCP decreased EPS matrix formation, which effectively sensitized biofilms to disinfection agents. Conclusion: The EPS matrix dispelled by CH paste with CMCP may be related to its bactericidal effect; the visualization and analysis of EPS formation and microbial colonization in dentin may be a useful approach to verify medicaments for antimicrobial therapy.

EPSAH, an exopolysaccharide from Aphanothece halophytica GR02, improves both cellular and humoral immunity as a novel polysaccharide adjuvant / 中国天然药物

EPSAH is an exopolysaccharide from Aphanothece halophytica GR02. The present study was designed to evaluate its toxicity and adjuvant potential in the specific cellular and humoral immune responses in ovalbumin (OVA) in mice. EPSAH did not cause any mortality and side effects when the mice were administered subcutaneously twice at the dose of 50 mg·kg(-1). Hemolytic activity in vitro indicated that EPSAH was non-hemolytic. Splenocyte proliferation in vitro was assayed with different concentrations of EPSAH. The mice were immunized subcutaneously with OVA 0.1 mg alone or with OVA 0.1 mg dissolved in saline containing Alum (0.2 mg) or EPSAH (0.2, 0.4, or 0.8 mg) on Day 1 and 15. Two weeks later, splenocyte proliferation, natural killer (NK) cell activity, production of cytokines IL-2 from splenocytes, and serum OVA-specific antibody titers were measured. Phagocytic activity, production of pro-inflammatory cytokines IL-1 and IL-12 in mice peritoneal macrophages were also determined. EPSAH showed a dose-dependent stimulating effect on mitogen-induced proliferation. The Con A-, LPS-, and OVA-induced splenocyte proliferation and the serum OVA-specific IgG, IgG1, and IgG2a antibody titers in the immunized mice were significantly enhanced. EPSAH also significantly promoted the production of Th1 cytokine IL-2. Besides, EPSAH remarkably increased the killing activities of NK cells from splenocytes in the immunized mice. In addition, EPSAH enhanced phagocytic activity and the generation of pro-inflammatory cytokines IL-1 and IL-12 in macrophages. These results indicated that EPSAH had a strong potential to increase both cellular and humoral immune responses, particularly promoting the development of Th1 polarization.

Industrial wastewater as raw material for exopolysaccharide production by Rhizobium leguminosarum

The objective of this study was to evaluate the exopolysaccharide (EPS) production by Rhizobium leguminosarum cultivated in wastewater generated by oil companies (WWOC1 and WWOC2) and fish processing industry (WWFP). The results obtained in Erlenmeyer flasks indicated that the rhizobial strain grew well in industrial wastewater. Generally, wastewater composition affected the growth and the EPS production. WWFP allowed good bacterial growth similar to that obtained with the standard medium (YMB). During growth, various quantities of EPS were produced and yields varied depending on the media. Growing in YMB, EPS production did not exceed 9.7 g/L obtained after 72 h of growth. In wastewater, the maximum EPS value reached 11.1 g/L obtained with the fish processing wastewater, after 72 h of growth. The use of a mixture of the oil company wastewater (WWOC2) and the fish processing wastewater (WWFP) as culture medium affected not only the rhizobial strain growth, but also EPS production. The highest EPS (42.4 g/L, after 96 h of culture) was obtained using a ratio of WWFP and WWOC2 of 50:50 (v:v). Therefore, this work shows the ability of Rhizobium leguminosarum, growing in industrial wastewater as new economic medium, to produce EPS. This biopolymer could be applied in enormous biotechnological areas.

Quick stimulation of Alcanivorax sp. by bioemulsificant EPS2003 on microcosm oil spill simulation

Oil spill microcosms experiments were carried out to evaluate the effect of bioemulsificant exopolysaccharide (EPS2003) on quick stimulation of hydrocarbonoclastic bacteria. Early hours of oil spill, were stimulated using an experimental seawater microcosm, supplemented with crude oil and EPS2003 (SW+OIL+EPS2003); this system was monitored for 2 days and compared to control microcosm (only oil-polluted seawater, SW+OIL). Determination of bacterial abundance, heterotrophic cultivable and hydrocarbon-degrading bacteria were carried out. Community composition of marine bacterioplankton was determined by 16S rRNA gene clone libraries. Data obtained indicated that bioemulsificant addition stimulated an increase of total bacterial abundance and, in particular, selection of bacteria related to Alcanivorax genus; confirming that EPS2003 could be used for the dispersion of oil slicks and could stimulate the selection of marine hydrocarbon degraders thus increasing bioremediation process.

Structural studies of the exopolysaccharide produced by a submerged culture of entomopathogenic fungus Metarhizium anisopliae / Estudio estructural del exopolisacárido producido por un cultivo sumergido del hongo entomopatogénico Metarhizium anisopliae

The exopolysaccharide (EPS) separated from the entomopathogenic fungus Metarhizium anisopliae was determined by gel permeation chromatography to be homogeneous. The high-performance anion-exchange chromatography with pulsed-amperometric detection (HPAE-PAD) showed a content of monosaccharides D-galactosamine and D-fucose at a molar ratio of about 2:1. The results obtained from Fourier transform-infrared spectroscopy (FT-IR) and second derivative FT-IR spectrum confirmed the proposed structure.

El exopolisacárido (EPS) separado desde el hongo entomopatogénico Metarhizium anisopliae determinado por cromatografía de exclusión en gel ser homogéneo. La cromatografía iónica de alto rendimiento con detección de pulso amperométrico (HPAE-PAD) mostró un contenido de monosacáridos D-galactosamina y D-fucosa en una relación molar de alrededor de 2:1. Los resultados obtenidos desde la espectroscopía infrarroja con transformada de Fourier (FT-IR) y la segunda derivada del espectro FT-IR confirmaron la estructura propuesta.

An Overview of Healthy and Functionality of Exopolysaccharides Produced by Lactic Acid Bacteria in the Dairy Industry.

Exopolysaccharides (EPS) synthesized by lactic acid bacteria (LAB) play a major role in the manufacturing of fermented dairy products such as yoghurt, drinking yoghurt, cheese, fermented cream, milk based desserts. The demand of consumers for natural dairy products with a smooth and creamy texture, low in fat and sugars, can be satisfied by a judicious use of LAB producing EPS. One of the major sensory attributes important for consumer preference of dairy products is firmness and creaminess. EPS’s may act both as texturizers and stabilizers, firstly increasing the viscosity of a final product, and secondly by binding hydration water and interacting with other milk constituents, such as proteins and micelles, to strengthen the rigidity of the casein network. As a consequence EPS can decrease syneresis and improve product stability. Furthermore it has been reported that EPS can positively affect gut health. The heteropolysaccharides from both mesophilic and thermophilic lactic acid bacteria have received renewed interest recently. Nowadays, in regard to demand of modern consumers focusing towards safe and healthy food without additives, new perspectives of development appear for these biopolymers. The GRAS (Generally Recognized As Safe) and probiotic status of some lactobacilli give to them more preference for consumable EPS production. One of their most described applications is their utilization as texturing agents naturally synthesized in the fermented food products. A better understanding of the structure-function relationship of EPS in a dairy food matrix remains a challenge to further improve applications of EPS to better satisfy the consumer demand for appealing, tasty and even healthier products.