Solid-state fermentation of cornmeal with the basidiomycete Ganoderma lucidum for degrading starch and upgrading nutritional value

Abstract

Aims: The objective of this research was to study the ability of the basidiomycete Ganoderma lucidum to degrade starch and upgrade nutritional value of cornmeal during solid-state fermentation (SSF). Methods and Results: On the basal medium that consisted of cornmeal and salt solution, a-amylase activity of G. lucidum reached its maximum value of 267 U g)1 of culture on day 20 after inoculation. Prolongation of fermentation time from 10 to 25 days increased significantly the degradation rate of starch and ergosterol yield (a kind of physiologically active substances of G. lucidum, also as an indicator of mycelial biomass) (P < 0AE01). Supplementation of glucose, sucrose or maltose to the basal medium also caused a significant increase in either the degradation rate of starch or the ergosterol yield as compared with control (P < 0AE01). Among five kinds of nitrogen sources supplemented, yeast extract, casamino acid and peptone were more effective than (NH 4 ) 2 SO 4 and NH 4 NO 3 , and yeast extract gave the highest degradation rate of starch and ergosterol yield, followed by peptone. Through orthogonal experiments, the theoretical optimum culture medium for SSF of this fungus was the following: 100 g cornmeal, ground to 30-mesh powder, moistened with 67 ml of nutrient salt solution supplemented with 3 g yeast extract and 7AE5 g glucose per litre. Conclusions: Under the optimum culture condition, the degradation rate of starch reached its maximum values of 70AE4%; the starch content of the fermented product decreased from 64AE5 to 25AE3%, while the reducing sugar content increased from 4AE2 to 20AE6%. SSF also produced a significant increase (P < 0AE01) from 11AE0 to 16AE5% in protein content. Significance and Impact of the Study: After SSF by G. lucidum, the digesting and absorbing ratio of cornmeal was strikingly increased and some active substances originated from G. lucidum remained in the fermented product. This implied that cornmeal could be processed into many kinds of special functional foods by SSF of G. lucidum.

Optimization of growth and extracellular glucoamylase production by Candida famata isolate

“…Similarly, Han et al (2005) reported that Basidiomycete Ganoderma lucidum gave the highest starch degradation with yeast extract. This is in agreement with the observation of Cherry et al (2004) who reported that the fungus A. fumigatus produces high amylase activity with yeast extract.…”

Enhanced production of ligninolytic enzymes and decolorization of molasses distillery wastewater by fungi under solid state fermentation

“…For instance, in a recent study, ergosterol of basidiomycete Ganoderma lucidum was used to study its growth after its solid state fermentation on cornmeal (Han et al 2005). In our study, all isolates exhibited different growth response on different SSF substrates as evidenced by varying amount of ergosterol produced (Table 2).…”

Native Macrofungi that Produce Lignin-Modifying Enzymes, Cellulases, and Xylanases with Potential Biotechnological Applications

“…Amylases are widely distributed enzymes in plants, animals, and microorganisms, but bacterial enzymes are in the greatest demand at the industrial level (Pandey et al 2000;Gupta et al 2003), even though there are reports that indicate that certain fungi are good amylase producers (Das and SenMandi, 1992;Pal et al 1980). There are studies where amylases of basidiomycetes have been exploited in order to increase the nutritional value of agroindustrial residues in the livestock industry (Han 2003;Han et al 2005). Thus, knowing the amylolytic potential of the isolates makes it possible to obtain new producers of amylases that can be used for the development of digestive adjuvants.…”