Production of pigments from the tropical marine-derived fungi Talaromyces albobiverticillius: New resources for natural red-colored metabolites

摘要

Filamentous fungi produce many chemical classes of metabolites bound to be used in various fields of industrial applications such as food, cosmetics, paper, textiles, medicine, biodegradation, waste remediation, etc. In this trend, scientists are actively looking for new fungal strains synthesizing original molecules with new potentialities. The present study is focused on pigment production from Talaromyces albobiverticillius strains, which were recently isolated from marine environments around Reunion Island, Indian Ocean. This study demonstrates their ability to produce a range of colored compounds exhibiting specific orange/red hues under submerged fermentation in potato dextrose broth (PDB), both seen in the mycelia and liquid medium. For the most promising strain, maximum levels of extracellular orange-yellow pigments (22.39 UA at 470 nm) and red pigments (18.67 UA at 500 nm) were attained in 8 days with an initial pH of 5.0 at 24 degrees C. Among the 12 components of the color hue, two compounds were produced in larger amounts in comparison with the total pigmented extracts (compound 4, red colored, presents two absorbance maxima: 7% lambda(1) = 422 nm, lambda(2) = 511 rim; and compound 8, orange colored, absorbs at lambda(1) = 469.8 nm as a maximum). The color characteristics of the extracellular fungal products measured by L*a*b* quantitative colorimetric system indicated variations between the three strains productions, as well as between the intracellular and extracellular colored molecules produced. An evolution of the colored compounds synthesized is thus highlighted, in relation with the growth phases of the fungus. These results provide information about the future directions towards large-scale cultivation of these fungi, which might support the industrial applications of the red pigments.