Production of short‐chain fructooligosaccharides (scFOS) using extracellular β‐D‐fructofuranosidase produced byAspergillus thermomutatus

Abstract

Aspergillus thermomutatus produces an extracellular β‐D‐fructofuranosidase when cultured in Khanna medium with sucrose as additional carbon source at 30°C under agitation for 72 hr. Addition of glucose and fructose in the culture medium affected the production of the enzyme negatively. The optimum hydrolytic activity was achieved at 60°C and pH 5.0, with half‐life (T50) of 30 hr at 50°C and 62% of its activity maintained at pH 5.0 for 48 hr. The extracellular extract containing β‐D‐fructofuranosidase was effective in producing fructooligosaccharides (FOS), mainly 1‐kestose. The highest concentration of FOS was obtained at 30°C and 60°C, indicating the existence of at least two enzymes with transfructosylating activity. At 30°C, the maximal FOS concentration was obtained from 48 to 72 hr, while at 60°C, it was achieved only at 72 hr. The best production of FOS (86.7 g/L) was obtained using 500 g/L sucrose as substrate. Practical application Fructooligosaccharides (FOS) are linear oligomers of fructose units with important applications in the food industry as sweetening agents and biopreservatives. Due to the presence of β‐glycosidic bonds, they cannot be hydrolyzed by human enzymes, allowing the use of FOS‐containing products by diabetics. FOS used in the preparation of dairy products imparts humectancy to soft baked products, lowers the freezing point of frozen desserts, provides crispness to low‐fat cookies, and provides many other advantages. Diets containing FOS can reduce the levels of triglycerides and cholesterol and improve the absorption of ions, such as Ca2+ and Mg2+. FOS also exhibit bifidogenic effect on Bifidobacterium and Lactobacillus strains in the colon. Industrially, FOS is produced during the transfructosylation reaction of sucrose catalyzed by β‐D‐fructofuranosidase. Identifying new sources of β‐D‐fructofuranosidase is an important challenge to meet its industrial demand.

Efficient Degradation for Raffinose and Stachyose of a β-D-Fructofuranosidase and Its New Function to Improve Gel Properties of Coagulated Fermented-Soymilk

“…According to statistics, the industrial production of β-D-fructofuranosidase largely relies on Aspergillus spp. [ 22 , 23 , 24 ], Bacillus spp. [ 16 , 19 ], and Bifidobacterium spp.…”

“…Most bacteria-secreted β-D-fructofuranosidases have an optimal pH within a range of 6.0–8.0 [ 11 , 20 , 32 ]. In contrast, most fungal β-D-fructofuranosidases exhibit the lowest enzyme activity at lower pH values, such as A. thermomutatus [ 24 ], A. terreus [ 33 ], and A. niveus [ 34 ]. Moreover, acidic or alkaline environments can challenge enzyme protein structure stability, which limits their potential applications.…”

“…exhibit optimal temperatures of 40 °C, 35 °C, and 30 °C, respectively [ 3 , 29 , 32 ]. However, certain β-D-fructofuranosidases secreted by microorganisms, such as those from A. thermomutatus [ 24 ] and A. terreus [ 33 ], have optimal temperatures as high as 60 °C, indicating that they are thermophilic enzymes that require more heat to maintain their enzymatic activity. Enzymes are bioactive molecules, and their protein stability is generally temperature sensitive.…”

“…LcFFase1s has been shown to maintain protein stability at temperatures of 50 °C and below, which is comparable to the thermal stability of some β-D-fructofuranosidases from bacteria and fungi, such as those from Gongronella sp. w5 [ 17 ], B. longum [ 25 ], A. thermomutatus [ 24 ], and A. niveus [ 34 ]. Good protein stability is a critical factor in ensuring normal catalytic activity of enzyme molecules.…”

Género Aspergillus: fuente potencial de péptidos bioactivos

“…Aspergillus flavus Peptidasa, fitasa, proteasa, lipasa, DNasa, elastasa, keratinasa, quitinasa, amilasa, poligalacturonasa [12]- [16] Aspergillus oryzae Hidrolasa, amilasa, tanasa, proteasa, fitasa, lipasa, transferasa, xylenasa, hexosaminidasa, naranginasa, peptidasa [12], [17]- [25] Aspergillus tamarii Proteasa, keratinasa, lipasa, DNasa, elastasa, xylanasa, tanasa [11], [13], [26], [27] Aspergillus nidulan Oxidasa, xylanasa [28], [29] Aspergillus clavatus Amilasa, celulasa [30] Aspergillus niger Proteasa, lipasa, peptinasa, amilasa, fitasa, keratinasa, DNasa, elastasa, OTasa, α-galactosidasa, nucleasa, hidrolasa, β-glucosidasa, xylanasa, tirosinasa [13], [17], [19], [31]- [41] Aspergillus ficuum Fitasa [19] Aspergillus fumigatus Fitasa, keratinasa, lipasa, proteasa, DNasa, elastasa, amilasa, tanasa, xylanasa [13], [19], [42]- [44] Aspergillus carbonarius Fitasa [19] Aspergillus tubingensis Fitasa, amilasa [19], [45] Aspergillus terreus Keratinasa, lipasa, proteasa, DNasa, elastasa [13] Aspergillus japonicus Fitasa [19] Aspergillus flavipes Hidrolasa, peptinasa [46], [47] Aspergillus ochraceus Tanasa [48] Aspergillus thermomutatus Invertasa [49] Aspergillus allahabadii Dextrinasa [50] Por otro lado, las nrps se caracterizan por poseer una estructura modular al menos de tres dominios: de adenilación (A), condensación (C) y proteína portadora de peptidilo (pcp), también conocida como tiolación (T) [55]. En la figura 2, se evidencia la síntesis de péptidos mediados por esta ruta metabólica.…”