Epidermal galactose spurs chytrid virulence and predicts amphibian colonization

The chytrid fungal pathogens Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans cause the skin disease chytridiomycosis in amphibians, which is driving a substantial proportion of an entire vertebrate class to extinction. Mitigation of its impact is largely unsuccessful and requires a thorough understanding of the mechanisms underpinning the disease ecology. By identifying skin factors that mediate key events during the early interaction with B. salamandrivorans zoospores, we discovered a marker for host colonization. Amphibian skin associated beta-galactose mediated fungal chemotaxis and adhesion to the skin and initiated a virulent fungal response. Fungal colonization correlated with the skin glycosylation pattern, with cutaneous galactose content effectively predicting variation in host susceptibility to fungal colonization between amphibian species. Ontogenetic galactose patterns correlated with low level and asymptomatic infections in salamander larvae that were carried over through metamorphosis, resulting in juvenile mortality. Pronounced variation of galactose content within some, but not all species, may promote the selection for more colonization resistant host lineages, opening new avenues for disease mitigation.

Estimation Of Glucose And Galactose Content In A Natural Polysaccharide Isolated From Tubers Of Colocasia Esculenta Using A Validated Rp-Hplc Method

Background: Now a days, the natural polysaccharides are preferred over synthetic polymers because they are biocompatible, cheap, and easily available than the synthetic ones. The polysaccharide obtained from the tuber of the Colocasia esculenta tubers was reported to exhibit many pharmaceutical applications as an excipient. Objective: The application of any polymer in formulating various dosage form depends upon their qualitative and quantitative chemical composition. Therefore, in the current research work, the quantitative composition of the polysaccharide isolated from Colocasia esculenta was determined by validated HPLC method. Methods: RP-HPLC analysis was performed on an Agilent, Zorbax Eclipse XDB C8 column (250 mm × 4.6 mm, 5 μm) with the mobile phase consisting of citrate buffer PH 5.5: Tetrahydrofuran: Acetonitrile (87.1:11.9:1 v/v) at a flow rate of 0.6 mL/min. UV detection was performed at 307 nm. The method was validated for various parameters as per ICH guidelines. Results: The calibration curve constructed for Glucose and Galactose was found linear with correlation coefficient of 0.997 and 0.994 respectively. The system suitability parameters, such as theoretical plate, tailing factor and relative standard deviation (RSD), were well within the limits. Solution stability data indicated that the solution was stable for 24 hours at 25°C. The water-soluble polysaccharide from Colocasia esculenta was found to contain glucose and galactose in the ratio 8:1. Conclusion: The validated RP-HPLC method was found to be specific, linear, precise, and accurate and can be successfully used for simultaneous estimation of glucose and galactose content in the polysaccharides.

Response of Lactobacillus plantarum VAL6 to challenges of pH and sodium chloride stresses

To investigate the effect of environmental stresses on the exopolysaccharide biosynthesis, after 24 h of culture at 37 °C with pH 6.8 and without sodium chloride, Lactobacillus plantarum VAL6 was exposed to different stress conditions, including pH (pHs of 3 and 8) and high sodium chloride concentration treatments. The results found that Lactobacillus plantarum VAL6 exposed to stress at pH 3 for 3 h gives the highest exopolysaccharide yield (50.44 g/L) which is 6.4 fold higher than non-stress. Under pH and sodium chloride stresses, the mannose content in exopolysaccharides decreased while the glucose increased in comparison with non-stress condition. The galactose content was highest under stress condition of pH 8 meantime rhamnose content increased sharply when Lactobacillus plantarum VAL6 was stressed at pH 3. The arabinose content in exopolysaccharides was not detected under non-stress condition but it was recorded in great amounts after 3 h of stress at pH 3. In addition, stress of pH 8 triggered the mRNA expression of epsF gene resulting in galactose-rich EPS synthesis. According to our results, the stresses of pH and sodium chloride enhance the production and change the mRNA expression of epsF gene, leading to differences in the monosaccharide composition of exopolysaccharides.

Relationship between iodine and carbohydrate contents in the seagrass Zostera marina on the northwestern Pacific coast of central Japan

Previously, we reported seasonal variation in iodine contents in the seagrass Zostera marina. Herein, we sought the factors controlling this variation, and investigated relationships between iodine and carbohydrate contents, using extracts and residues of seagrass samples extracted with 0.1 N HCl. In plants, carbohydrates in HCl-extracted and residual fractions are considered to represent storage and structural carbohydrates, respectively. On average, 44% and 56% of total iodine in samples was contained in the HCl-extracted and residual fractions, respectively. Both HCl-extracted and residual iodine contents showed seasonal trends similar to that of total iodine, being high in winter–spring and low in summer. Total and HCl-extracted carbohydrate contents showed reverse seasonal trends from those of iodine, whereas residual carbohydrate contents had comparable values throughout the sampling period. In the total and HCl-extracted fractions, negative correlations between iodine and carbohydrate contents were confirmed, suggesting that carbohydrates do not play important roles in iodine accumulation. Although most monosaccharide contents were not correlated with iodine contents in these two fractions, residual galactose content was positively correlated with residual iodine. We accordingly suggest that one or more specific structural carbohydrate constituents may potentially function as an iodine store in Z. marina.

OPTIMASI PERLAKUAN POLYETHYLENE GLIKOL (PEG) 6000 TERHADAP ISOLASI AGAROSA RUMPUT LAUT Glacilaria sp.

Optimation of Polyethylene Glycol (PEG) 6000 Treatment on Isolation of Agarose Seaweeds of Glacilaria sp Isolation of agarose from seaweeds (Glacilaria sp) had been done in acid, base, and neutral condition by using polyethylene glycol (PEG) method. Glacilaria sp, Seaweeds that used in this research was cultured by farmer in Muara Gembong, Bekasi. It used PEG with concentration 10%, 15%, 20%, 25%, & 30%. The scope of this research ware determination of seaweeds, seaweeds water content, isolation of agarose from seaweeds, and quality test of agarose. Parameter test of agarose quality include the strength of gel, the content of sulfat, measurement of galactose content and its proksimat. The high yield was 61,27% r in PEG 30%. The best quality of agarose was resulted in PEG 20% because of the highest strength of gel was 379,04 g/cm2.The lowest sulfat concentration was 1,33% and galactose was 17,39%.Key words: polyethylene glycol, PEG 6000, agarose, seaweeds, glacilaria sp ABSTRAK Isolasi agarosa dari rumput laut Glacilaria sp telah dilakukan dalam suasana asam, basa dan netral dengan metode polyethylene glikol (PEG). Rumput lauat yang digunakan adalah Gracilaria sp yang dibudidayakan oleh petani di Muara Gembong, Bekasi dengan perlakuan konsentrasi PEG 10%, 15%, 20%, 25% dan 30%. Ruang lingkup penelitian ini meliputi uji determinasi rumput laut, penetapan kadar air rumput laut, isolasi agarosa dari rumput laut, serta uji kualitas agarosa. Parameter pengujian kualitas agarosa terdiri dari kekuatan gel, kandungan sulfat, dan pengukuran kandungan galaktosa serta proksimatnya. Isolasi agarosa perlakuan konsentrasi polyethylene Glikol (PEG) 6000 pada rumput laut Glacilaria sp diperoleh rendemen paling tinggi terdapat pada perlakuan PEG 30% yaitu sebesar 61,27%. Akan tetapi untuk kualitas agarosa yang paling baik terdapat pada perlakuan konsentrasi PEG 20% karena diperoleh kekuatan gel paling tinggi sebesar 379,04 g/cm2. Kadar sulfat yang paling rendah sebesar 1,33% dan kadar galaktosa sebesar 17,39%.Kata Kunci: polyethylene glikol, PEG 6000, agarosa, rumput laut, glacilaria sp