Statistical approach to evaluate effect of temperature and moisture content on the production of antioxidant naphtho-gamma-pyrones and hydroxycinnamic acids by Aspergillus tubingensis in solid-state fermentation

Abstract

Non-ochratoxigenic Aspergillus tubingensis G131 is a filamentous fungus that can produce naphtho-gamma-pyrones (NγPs), polyketide pigments that exhibit interesting antioxidant properties. This study aims to investigate the effect of two critical parameters, temperature and moisture content on the fungus grown in solid-state fermentation using agricultural by-products (vine shoots and wheat bran) as sole medium. From the kinetic productions of secondary metabolites NγPs (asperpyrone E, dianhydroaurasperone C, fonsecin, fonsecin B and ustilaginoidin A), alkaloids (nigragilin and aspernigrin A), degradation products from the solid medium (β-d-glucose, p-coumaric acid and trans-ethyl ferulate), ergosterol and conidia obtained for different temperatures and moisture contents, a principal component analysis (PCA) was carried out to highlight the production patterns of these compounds. This approach allowed us to determine that fonsecin, the compound of higher interestexhibiting the most interesting antiradical potential-is particularly more produced at 25 °C and 66% of moisture content. This study underlines the importance of temperature and moisture content on naphtho-gamma-pyrones and hydroxycinnamic acid production using solid-state fermentation and contributes to the development of agroindustrial by-product valorization.

Determination of Variable Humidity Profile for Lactic Acid Maximization in Fungal Solid-State Fermentation

“…Therefore, as biomass production was restricted, the fungus dedicated itself to producing a greater quantity of the metabolite LA. This behavior was also observed in [17], where the effect of humidity on the production of antioxidant naphtho-gammapyrones and hydroxycinnamic acids by Aspergillus tubingensis in SSF was studied. Here, biomass production decreased with increasing humidity, while metabolite production increased.…”

“…It is important to note that most of the fungal SSF studies found so far have focused on the effect of varying the initial moisture content of the solid substrate while keeping the humidified air flow static throughout the bioprocess [15][16][17][18][19]. Furthermore, one study was proposed a humidity control strategies based in capillary-water supply to control temperature and RH in SSF tray bioreactor [14].…”

“…This can be done in two ways: either controlling the humidity of the air while keeping its temperature constant, or controlling the temperature of the air while keeping its humidity constant [14]. However, in most fungal SSF studies, the variation of the moisture solid substrate was manually studied, conditioning its humidity at the beginning of fermentation, and then keeping a constant relative humidity airflow [15][16][17][18][19].…”

Prospects and application of solid-state fermentation in animal feed production – a review

“…One of the numerous characteristics of SSF is that they are developed in very narrow temperature ranges. The importance of temperature in the SSF process is that it could regulate the outcome of fermentation, such as enzyme inhibition increase or decrease of a particular metabolite (Carboué et al, 2020;Kumar et al, 2021). Furthermore, microorganisms have specific temperature ranges where they have optimal growth.…”

Optimization of Fermentation Conditions for 2,3,5-Trimethylpyrazine Produced by Bacillus amyloliquefaciens from Daqu

“…According to the previous reports on solid-state fermentation [18,29,30], temperature, bottling capacity, and water addition were selected as single factors to investigate their effects on the TMP production in wheat medium. With the method of control variables, the temperatures were 19 • C, 28 • C, 37 • C, 46 • C, and 55 • C (with fixed bottling capacity of 100 g/250 mL and water addition of 50 mL); the bottling capacities were 80 g/250 mL, 90 g/250 mL, 100 g/250 mL, 110 g/250 mL, and 120 g/250 mL (with fixed temperature of 37 • C and water addition of 50 mL); and the water additions were 30 mL, 40 mL, 50 mL, 60 mL, and 70 mL (with fixed temperature of 37 • C and bottling capacity of 100 g/250 mL).…”