Mycelia Growth and Production of Total Flavonoids and 4H-pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl- by Schizophyllum commune Using a Bubble Column Bioreactor Considering Aeration Effect and Mass Transfer Study

Higher fungi are a major source of bioactive secondary metabolites, and researchers have established the existence of biochemical pathways solely for the purpose of producing mycotoxins and other natural products in fungi through the study of ecological chemical interactions.1 Recently, wood-degrading fungi received great attention for its possible use as antimicrobial agent. Schizophyllum commune, a species of basidiomycetes belonging to the Schizophyllaceae of Agaricales, played an important ecological role in degrading woody forest litter. This filamentously growing fungus secreted a neutral homoglucan that consists of a backbone chain of 1,3-β-D-glucopyranoses units linked with single 1,6-bonded β-D-glucopyranoses at about every third glucose molecule in the basic chain, called “Schizophyllan”.2 This polysaccharide has attracted attention in recent years in the pharmaceutical industry as an immunomodulatory, antineoplastic, and anti-viral agent with activities higher than other glucans. In addition, it is also applied in enhanced oil recovery, and cosmetics.3 Based on literature review, flavonoids are ubiquitous in photosynthesizing cells and could exert antifungal activity to inhibit the growth or spore germination.4 For example, Quercetin (3,3’,4’,5,7-pen tahydroxy flavone) is one of the most common native flavonoids occurring mainly in glycoside forms such as rutin (5,7,3’,4’-OH, 3-rutinose).5 Previous study done by Teoh et al.6 revealed that 4H-pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl(DDMP) belonged to the flavonoid fraction, and it was found to provide antifungal activities towards selected wood-degrading fungi of rubberwood. This unique sugar residue allowed saponins to scavenge superoxides by forming hydroperoxide intermediates, thus preventing biomolecular damage by free radicals.7 Bubble column bioreactor is a promising device for gas-liquid mass transfer and was being considered in biochemical application, especially for fermentation process.8 It also provides a number of advantages in both design and operation, such as high heat and mass transfer rates, compactness and low operating and maintenance costs. Furthermore, there is no mechanical agitation, and the air bubbles forced through the air compressor were responsible for the induced turbulent liquid mixing and the acMycelia Growth and Production of Total Flavonoids and 4H-pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methylby Schizophyllum commune Using a Bubble Column Bioreactor Considering Aeration Effect and Mass Transfer Study