Vol.:(0123456789) 1 3 Waste and Biomass Valorization https://doi.org/10.1007/s12649-018-0430-7 ORIGINAL PAPER Use of Algae Biomass Obtained by Single-Step Mild Acid Hydrolysis in Hydrogen Production by the β-Glucosidase-Producing Clostridium beijerinckii Br21 Bruna Constante Fonseca 1  · Giovanni Dalbelo 1  · Valeria Cress Gelli 2  · Sibeli Carli 1  · Luana Parras Meleiro 1  · Ana Lúcia Ribeiro Latorre Zimbardi 1  · Rosa Prazeres Melo Furriel 1  · Delia Rita Tapia 1  · Valeria Reginatto 1 Received: 13 April 2018 / Accepted: 22 August 2018 © Springer Nature B.V. 2018 Abstract Macroalgae biomass is a potential feedstock for fermentative H 2 production: it has high carbohydrate concentration and is lignin-free. Here, we optimize a mild acid treatment of Kappaphycus alvarezii biomass by an experimental design 2 4 . The optimal acid treatment conditions were 90 °C, HCl concentration of 55.9 mmol/L, 0.375 g of algae mass, and 8 h of treatment. Under these conditions, the hydrolysate presented mono-, but also di- and oligosaccharides. We used this hydro- lysate as substrate for fermentative hydrogen (H 2 ) production by the Clostridium beijerinckii Br21 grown in two diferent conditions: (1) in medium containing galactose and no β-glucosidase activity; (2) in medium with cellobiose to stimulate β-glucosidase activity, which was 0.33U/mL. The fermentative assay conducted in the presence of the C. beijerinckii Br21 with β-glucosidase activity provided higher H 2 concentration and yield as compared to the assay accomplished in the pres- ence of the inoculum with no β-glucosidase activity—171.76 ± 2.10 and 140.95 ± 10.92 mL of H 2 /L, and 70.3 ± 0.9 and 62.7 ± 4.9 mL of H 2 /g of dry algae, respectively. Therefore, a fermentative β-glucosidase-producing organism such as C. beijerinckii Br21 can potentially complete biomass saccharifcation for later renewable H 2 production. Keywords Kappaphycus alvarezii · Acid treatment · Factorial design · Biohydrogen Statement of Novelty Kappaphycus alvarezii biomass has never been explored as feedstock for H 2 production. A biomass hydrolysate con- taining mostly di- and oligosaccharides and only small monosaccharide concentrations was used as substrate for fermentative H 2 production by Clostridium beijerinckii Br21. The fermentation inoculum grown in cellobiose pre- sented β-glucosidase activity of a C. beijerinckii strain, which has been described for the frst time in this work. β-glucosidase activity stimulation in the inoculum helped C. beijerinckii Br21 to produce higher H 2 concentration per unit of algae biomass as compared to the inoculum grown in galactose with no β-glucosidase activity. Biomass hydrolysis to the monosaccharide level was not necessary because the H 2 -producing microorganism can produce hydrolases that help to consume higher-molecular-weight saccharides. Introduction Hydrogen (H 2 ) is a clean fuel; its burning produces water only [1–3]. However, current strategies to produce H 2 demand high amounts of energy or rely on fossil fuel-based methods [4]. H 2 can also originate from renewable fermen- tation of carbohydrate-rich materials, such as wastewater, wastes, and biomasses, which is a more sustainable and eco- nomically viable process [3]. Various renewable biomasses can be used as low-cost substrate for fermentative H 2 pro- duction, which signifcantly reduces production costs [5, 6]. * Valeria Reginatto valeriars@fclrp.usp.br 1 Departamento de Química, Faculdade de Filosofa Ciências e Letras de Ribeirão Preto-FFCLRP, Universidade de São Paulo, USP. Av. Bandeirantes, 3900, Ribeirão Preto, SP CEP 14040-030, Brazil 2 Departamento de Pesca – Núcleo de pesquisa e desenvolvimento do Litoral Norte – Agência Paulista de Pesquisa Agropecuária, Secretaria de Agricultura e Abastecimento do Estado de São Paulo, Ubatuba, SP, Brazil