Extraction of Chitosan with Different Physicochemical Properties from Cunninghamella echinulata (Thaxter) Thaxter for Biological Applications.

The conventional production of chitosan from crustaceans has many limitations. An attempt was made to optimize chitosan production from fungi. Soil fungi were isolated, identified, and screened for high glucosamine content. Among the fungal isolates tested, Cunninghamella echinulata showed high glucosamine content. The biomass production of C. echinulata was standardized under different growth parameters. The physicochemical characterization of derived chitosan isolates was distinctive and diverged as supported by the FT-IR, molecular mass distribution, degree of deacetylation, and crystallinity. Molecular mass distribution ranged from 1 to 9 mers. The degree of deacetylation was observed to be maximum in C6 (80.88%), which increased with the increase in alkali concentration. In the chitosan isolate, C1 was non-toxic to Vero cells up to 250 µg/mL. In the physicochemical and functional properties of chitosan isolate, C1 was found to be unique and diverse; further detailed investigations on this isolate might help to develop some biomaterials with improved biocompatibility.

Mass cultivation of UV-B adapted Arthrospira platensis RRGK under open raceway pond for the production of Poly-ß-hydroxy butyrate.

Six different strains of cyanobacteria were isolated from the freshwater lake, Arakkonam, India. Staining of cells with Nile Red showed the presence of large quantities of PHB granules in the cell cytoplasm of Arthrospira. Molecular identification of the strain was carried out using 16S rRNA analysis and their systematic position was ascertained as Arthrospira platensis RRGK. Studies were carried out on random mutagenesis approach using UV-B radiation for enhancing the production of PHB. Further, Response Surface Methodology was used for optimization of pH, temperature, and sodium bicarbonate for higher biomass and PHB production. Under open raceway pond A. platensis RRGK produced biomass concentration of 2.2±0.13gL-1 and 131±0.36gL-1 of PHB content. It was chemically characterized through FTIR, DSC, TGA and XRD analyses. Hence, PHB can be produced from cyanobacteria by sequestering harmful CO2. It can also be used as a substitute for synthetic polymers in tissue engineering.

Optimization of extracellular glucan production from Pleurotus eryngii and its impact on angiogenesis.

Pleurotus eryngii, an edible mushroom with therapeutic potential was optimized using response surface methodology of four-factor Box-Behnken design for maximum mycelial biomass and extracellular glucan (EPS) production. The model predicts to gain a maximal mycelial biomass and extracellular polysaccharide at 39.4 g/l; 36.04 g/l of glucose, 8.27 g/l; 7.51 g/l of yeast extract, pH 6.99; 7.07 and temperature 26.2°C; 25.84°C, respectively. The validation experiments showed that the model was significant and in close agreement with the model prediction. The evaluation of extracellular polysaccharide on angiogenesis by ex vivo CAM assay showed that there was significant inhibition in neo-vascularization.

Studies on screening, isolation and purification of a fibrinolytic protease from an isolate (VK12) of Ganoderma lucidum and evaluation of its antithrombotic activity.

Antithrombotic activity of a protease purified from a medicinal mushroom, Ganoderma lucidum, has been evaluated platelet aggregation in vitro and pulmonary thrombosis in vivo. The purified protease exhibited concentration dependent inhibitory effects on platelet aggregation induced by ADP (adenosine diphosphate), with an IC(50) value of 2.4 mg/mL. The purified protease protected mice against thrombotic death or paralysis induced by collagen and epinephrine in a dose dependent manner when administered orally. It produced a significant inhibition of thrombotic death or paralysis at 60 µg/kg body weight, while aspirin produced a significant inhibition of thrombosis at 10-20 mg/kg body weight. The purified protease also has showed fibrinolytic activity and alters coagulation parameters such as activated partial thromboplastin time (APTT), and thrombin time (TT) in rat platelet. These results suggested that the antithrombotic activity of Ganoderma lucidum protease might be due to antiplatelet activity rather than anticoagulation activity.