Grape Stalk Valorization: An Efficient Re-Use of Lignocellulosic Biomass through Hydrolysis and Fermentation to Produce Lactic Acid from <i>Lactobacillus rhamnosus</i> IMC501
Sergio D’ambrosio,
Lucio Zaccariello,
Saba Sadiq,
Marcella D’Albore,
Giovanna Battipaglia,
Maria D’Agostino,
Daniele Battaglia,
Chiara Schiraldi,
Donatella Cimini
Affiliations
Sergio D’ambrosio
Section of Biotechnology, Medical Histology and Molecular Biology, Department of Experimental Medicine, University of Campania L. Vanvitelli, Via de Crecchio 7, 80138 Naples, Italy
Lucio Zaccariello
Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania L. Vanvitelli, Via Vivaldi 43, 81100 Caserta, Italy
Saba Sadiq
Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania L. Vanvitelli, Via Vivaldi 43, 81100 Caserta, Italy
Marcella D’Albore
Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania L. Vanvitelli, Via Vivaldi 43, 81100 Caserta, Italy
Giovanna Battipaglia
Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania L. Vanvitelli, Via Vivaldi 43, 81100 Caserta, Italy
Maria D’Agostino
Section of Biotechnology, Medical Histology and Molecular Biology, Department of Experimental Medicine, University of Campania L. Vanvitelli, Via de Crecchio 7, 80138 Naples, Italy
Daniele Battaglia
Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania L. Vanvitelli, Via Vivaldi 43, 81100 Caserta, Italy
Chiara Schiraldi
Section of Biotechnology, Medical Histology and Molecular Biology, Department of Experimental Medicine, University of Campania L. Vanvitelli, Via de Crecchio 7, 80138 Naples, Italy
Donatella Cimini
Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania L. Vanvitelli, Via Vivaldi 43, 81100 Caserta, Italy
Lactobacillus rhamnosus is a homofermentative probiotic strain that was previously demonstrated to grow on lignocellulosic-derived raw materials and to convert glucose into L-lactic acid (LA) with yields that vary between 0.38 and 0.97 g/g. Lactic acid is a key platform chemical, largely applied in different biotechnological fields (spanning from the pharmaceutical to the food sector) and also as a building block for the production of biodegradable polymers. In the present study, grape stalks were evaluated as sources of fermentable sugars for the growth of L. rhamnosus IMC501 and for the production of LA, since millions of hectoliters of wine are produced every year worldwide, generating a huge amount of waste. Although grape stalks are quite recalcitrant, the combination of a steam explosion pre-treatment with optimized two-step hydrolysis and commercial enzymes (Cellic-CTec2) allowed us to obtain a cellulose conversion efficiency of about 37% and to develop small-scale 2 L batch fermentation processes. Results successfully demonstrate that L. rhamnosus IMC501 can tolerate biomass-derived inhibitors and grow on grape stalk hydrolysate without the need for additional sources of nitrogen or other nutritional elements, and that the strain can convert all glucose present in the medium into LA, reaching the maximal theoretical yield.
