Xylooligosaccharides production by fungi cultivations in rice husk and their application as substrate for lactic acid bacteria growth

Abstract We describe a three-steps bioprocess to convert rice husk as source of xylooligosaccharides and then used these prebiotics to grow lactic acid bacteria as a model to produce probiotics from vegetal sources. First, Aspergillus brasiliensis BLf and the recombinant Aspergillus nidulans XynC A773 strains were solid-state cultivated in rice husk to produce xylanases (234.7 ± 0.01 U·g −1 and 192 ± 0.03 U·g −1 substrate, respectively). These enzymatic preparations were directly applied to rice husk to hydrolyze its hemicellulosic structure and obtain xylooligosaccharides (37.25 mg XOS·g −1 substrate and 75.92 mg XOS·g −1 substrate, respectively). Prebiotic effect of XOS was tested by cultivating probiotic strains Lactobacillus plantarum BL011 and Bifidobacterium lactis B-12, which grew in this substrate. The results in this work showed that it is possible to produce xylooligosaccharides and then proceed to use these prebiotic sugars to grow probiotic bacteria using the same agro-residue, being possible their use in food related applications.