A molasses habitat-derived fungus Aspergillus tubingensis XG21 with high β-fructofuranosidase activity and its potential use for fructooligosaccharides production

Abstract

The industrial microorganisms used for fructooligosaccharides (FOS) synthesis are generally fermented with sucrose as carbon source to induce the production of β-fructofuranosidase (FFase) having transfructosylation activity. Consequently, isolation of novel FFase producers from a sucrose-enriched biotope would help improve FOS productivity and reduce the process cost. Here, three fungi isolated from a unique sugarcane molasses habitat were found to possess FFase activity and one of them, XG21, exhibited a high capacity to synthesize FOS. Analysis of its morphological properties and ribosomal internal transcribed spacer (ITS) sequence allowed the taxonomic position to be assigned and it was thus identified as Aspergillus tubingensis XG21. It could utilize various potential carbon sources for vigorous growth, but only produced high-level FFase activity on sucrose. Furthermore, the transfructosylation ability and FOS synthesis were analyzed by TLC and HPLC. During the transfructosylation reaction, an increase in sucrose concentration led to the remarkable enhancement in FOS formation with the maximum content of up to 56.9% within 8 h. Finally, the sugarcane molasses was used to cultivate A. tubingensis XG21 and the optimal FFase activity reached up to 558.3 U/g, which was 88.9% higher than that with sucrose as carbon source. These results indicate that A. tubingensis XG21 can be considered as a new genetic resource adapted to cheaply available carbon sources for FOS production.

Purification and characterization of an invertase and a transfructosylase from Aspergillus terreus

“…In general, intracellular invertase activity steadily increase with the age of cultures and is maintained at high levels, as observed for Aspergillus japonicus (Chen, ) and Aspergillus tubingensis (Xie et al, ). However, this unusual pattern of invertase activity production was also observed for Thermomyces lanuginosus (Chaudhuri, Bharadwaj, & Maheshwari, ).…”

“…Invertases from A. niger and A. tubingensis produced the fructooligosaccharide 1‐kestose when incubated in solutions with high sucrose concentrations (L'Hocine et al, ; Xie et al, ). Transfructosylating activity is quite interesting from a biotechnological view since its products, fructooligosaccharides, are functional food ingredients with prebiotic properties.…”

Fructo-oligosaccharides (FOS) production by fungal submerged culture using aguamiel as a low-cost by-product

“…But, other factors limiting their synthesis, for example the cost of enzyme production, their purification and the use of commercial culture medium (Nascimento, Nobre, Cavalcanti, Teixeira, & Porto, 2016). Therefore, recent studies have been focused on use of low cost materials as a viable alternative for FOS production (Xie et al, 2017). Agave plants are abundant in some regions of Mexico and some species are known as "magueyes pulqueros" (Agave salmiana, agave mapisaga, A. atrovirens, A. americana, A. ferox) because their main use is for the pulque production.…”

Putative Genes Identified in Alkaloids Biosynthesis in Dendrobium officinale by Correlating the Contents of Main Bioactive Metabolites with Genes Expression between Protocorm-like Bodies and Leaves

“…Polysaccharides are major medicinal components in D. o cinale [12]. The biosynthesis pathway of polysaccharides in medicinal plants can be divided into three main stages [13,14]. At the rst stage, sucrose produced by through chloroplast photosynthesis in leaves is converted into two kind of monosaccharides such as glucose 1-phosphate (Glc-1P) and fructose-6-phosphate (Fru-6P) under a series of enzymes.…”