Purification and characterization of an iron-activated alkaline phosphatase produced by Rhizopus microsporus var. microsporus under submerged fermentation using

Current researches have been carried out to find microorganisms that can produce enzymes for differentbiotechnological purposes. Among the enzymes, the microbial phosphatases, responsible for hydrolyzingphosphoric acid anhydrides and esters, have been often employed in different sectors such as molecularbiology experiments and clinical diagnosis. This work aims to purify and characterize the alkaline phosphataseproduced by Rhizopus microsporus var. microsporus under submerged fermentation. This enzyme was purified9.9-fold with 13% recovery. The molecular mass for the glycoprotein was 123 kDa estimated with gel filtrationand 128 kDa with sodium dodecyl sulfate polyacrylamide gel electrophoresis, indicating that it is a monomericenzyme. Optimal temperature and pH for the alkaline phosphatase was 45°C and 8.5, respectively, with halflife (t50) of 40 minutes at 50°C. Under alkaline pH, the phosphatase activity was above 50% for 24 hours.FeCl3 increased the phosphatase activity. Alkaline phosphatase hydrolyzed different substrates, especiallyp-nitrophenylphosphate, with Km of 0.45 and 0.38 mmol l−1, in presence and absence of FeCl3, respectively.Thus, alkaline phosphatase from R. microsporus var. microsporus was characterized, highlighting importantcharacteristics and, thereby, making possible a future application.

Fungal Diversity and Enzyme Activity Associated with the Macroalgae, Agarum clathratum

Agarum clathratum, a brown macroalgae species, has recently become a serious environmental problem on the coasts of Korea. In an effort to solve this problem, fungal diversity associated with decaying A. clathratum was investigated and related β-glucosidase and endoglucanase activities were described. A total of 233 fungal strains were isolated from A. clathratum at 15 sites and identified 89 species based on morphology and a multigene analysis using the internal transcribed spacer region (ITS) and protein-coding genes including actin (act), β-tubulin (benA), calmodulin (CaM), and translation elongation factor (tef1). Acremonium, Corollospora, and Penicillium were the dominant genera, and Acremonium fuci and Corollospora gracilis were the dominant species. Fifty-one species exhibited cellulase activity, with A. fuci, Alfaria terrestris, Hypoxylon perforatum, P. madriti, and Pleosporales sp. Five showing the highest enzyme activities. Further enzyme quantification confirmed that these species had higher cellulase activity than P. crysogenum, a fungal species described in previous studies. This study lays the groundwork for bioremediation using fungi to remove decaying seaweed from populated areas and provides important background for potential industrial applications of environmentally friendly processes.