Thraustochytrids of Mangrove Habitats from Andaman Islands: Species Diversity, PUFA Profiles and Biotechnological Potential

Thraustochytrids are the most promising microbial source for the commercial production of docosahexaenoic acid (DHA) for its application in the human health, aquaculture, and nutraceutical sectors. The present study isolated 127 thraustochytrid strains from mangrove habitats of the south Andaman Islands, India to study their diversity, polyunsaturated fatty acids (PUFAs), and biotechnological potential. The predominant strains were identified as belonging to two major genera (Thraustochytrium, Aurantiochytrium) based on morphological and molecular characteristics. The strain ANVKK-06 produced the maximum biomass of 5.42 g·L−1, while ANVKK-03 exhibited the maximum total lipid (71.03%). Omega-3 PUFAs such as eicosapentaenoic acid (EPA) accumulated up to 11.03% in ANVKK-04, docosapentaenoic acid (DPA) up to 8.65% in ANVKK-07, and DHA up to 47.19% in ANVKK-06. ANVKK-06 showed the maximum scavenging activity (84.79 ± 2.30%) while ANVKK-03 and ANVKK-10 displayed the highest antibacterial activity against human and fish pathogens, S. aureus (18.69 ± 1.2 mm) and V. parahaemolyticus (18.31 ± 1.0 mm), respectively. All strains were non-toxic as evident by negative blood agar hemolysis, thus, the thraustochytrids are suggested to be a potential source of DHA for application in the health care of human and fish

Antioxidant and Anti-Breast Cancer Properties of Hyaluronidase from Marine Staphylococcus aureus (CASMTK1)

This work studied the antioxidant and anti-breast cancer properties of hyaluronidase, extracted from a potential marine strain, Staphylococcus aureus (CASMTK1), isolated from Parangipettai coastal waters in southeast coast of India. The Staphylococcal enzyme production was tested under different carbon and nitrogen sources; and recorded the maximum production when the microbial strain was cultured with starch as the carbon source and ammonium sulphate as the inorganic nitrogen source with the enzyme production of 92.5 U/mL and 95.0 U/mL, respectively. The hyaluronidase enzyme production was also tested in different pH and temperature; and recorded the maximum yield of 102.5 U/mL in pH 5 and that of 95.5 U/mL in 45 °C. The partially purified enzyme was subjected to FTIR and FT Raman technique and found the presence of the amide- I and II, Carboxyl, N-H bending, C-H stretching and α-helices and β-sheet proteins between wave number 1500–1700 cm−1. The partially purified enzyme also exhibited strong antioxidant and in-vitro breast cancer properties. The enzyme showed the highest hydroxyl radical scavenging activity of 79% at the 50 µg/mL concentration, and this activity increased in a dose-dependent manner. The enzyme inhibited proliferation of the breast cancer cell line of MCF-7, and it caused 100% cell death at the concentration of 80 µg/mL. The enzyme generated capacity of producing free radicles that damage the cancer cells, and this effect was very nearer to the standard drug, paclitaxel. The enzyme damaged the cancer cells and induced apoptosis in 78% of cancer cells as evident by condensed or fragmented chromatin at 40 µg/mL. Further purification of the enzyme, analysis of its molecular aspects, and elucidation of exact mechanisms of its biological activities will throw new light on the utility of staphylococcal hyaluronidase in anticancer chemotherapy