The market for nutraceutical molecules is growing at an impressive pace in all Western countries. A convenient source of bioactive compounds is found in vegetable waste products, and their re-use for the recovery of healthy biomolecules would increase the sustainability of the food production system. However, safe, cheap, and sustainable technologies should be applied for the recovery of these beneficial molecules, avoiding the use of toxic organic solvents or expensive equipment. The soil bacterium Bacillus subtilis is naturally endowed with several enzymes targeting complex vegetable polymers. In this work, a raw bacterial culture supernatant was used to assist in the extraction of bioactives using isothermal pressurization cycles. Besides a wild-type Bacillus subtilis strain, a new strain showing increased secretion of cellulases and xylanases, pivotal enzymes for the digestion of the plant cell wall, was also used. Results indicate that the recovery of compounds correlates with the amount of cellulolytic enzymes applied, demonstrating that the pretreatment with non-purified culture broth effectively promotes the release of bioactives from the vegetable matrix. Therefore, this approach is a valid and sustainable procedure for the recovery of bioactive compounds from food waste.

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A large body of literature has accumulated on the beneficial impact of the administration ofBacillito dairy cows, particularly on dry matter intake, lactation performances and milk composition. In this work we sought to establish whether the ability ofB. subtilisto secrete cellulase and xylanase enzymes could be involved in the positive effect exerted by these bacteria. Several feed ingredients were treated with twoB. subtilisstrains only differing for the amount of secreted cellulosolytic and xylanolytic enzymes, and feed quality was assessed. We found that in vitro fibre digestibility correlated with the activity of those enzymes. Our results revealed thatB. subtiliscellulases and xylanases can effectively improve forage quality, providing a scientific rationale on the use of Bacilli as forage supplements to improve animal productivity. Moreover, a particular care was taken in designing a sustainable and economically viableBacillus-based additive preparation process.

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