Isolation of Paraclostridium CR4 from sugarcane bagasse and its evaluation in the bioconversion of lignocellulosic feedstock into hydrogen by monitoring cellulase gene expression

Author(s)

Silva Rabelo, Camila Abreu B. ^[1] ; Okino, Cintia Hiromi ^[2] ; Sakamoto, Isabel Kimiko ^[1] ; Amancio Varesche, Maria Bernadete ^[1]

Affiliation

^[1] Univ Sao Paulo, Dept Hydraul & Sanitat, Lab Biol Proc, Engn Sch Sao Carlos, EESC USP, Campus 2, BR-13563120 Sao Carlos, SP - Brazil

^[2] Embrapa Pecuaria Sudeste, Rod Washington Luiz, Km 234, POB 339, Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: Science of The Total Environment; v. 715, MAY 1 2020.
• Web of Science Citations: 0

Abstract

Bioconversion of sugarcane bagasse (SCB) into hydrogen (H-2) and organic acids was evaluated using a biomolecular approach to monitor the quantity and expression of the cellulase (Cel) gene. Batch reactors at 37 degrees C were operated with Paraclostridium sp. (10% v/v) and different substrates (5 g/L): glucose, cellulose and SCB in natura and pre-heat treated and hydrothermally. H-2 production from glucose was 162.4 mL via acetic add (2.9 g/L) and 78.4 mL from cellulose via butyric acid (2.9 g/L). H-2 production was higher in hydrothermally pretreated SCB reactors (92.0 mL), heat treated (62.5 mL), when compared to in natura SCB (51.4 mL). Butyric acid (5.8, 4.9 and 4.0 g/L) was the main acid observed in hydrothermally, thermally pretreated, and in natura SCB, respectively. In the reactors with cellulose and reactors with hydrothermally pretreated SCB, the Cel gene copy number 3 and 2 log were higher, respectively, during the stage of maximum H-2 production rate, when compared to the initial stage. Differences in Cel gene expression were observed according to the concentration of soluble sugars in the reaction medium. That is, there was no gene expression at the initial phase of the experiment using SCB with 2.6 g/L of sugars and increase of 2.2 log in gene expression during the phases with soluble sugars of <1.4 g/L. (C) 2020 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 18/26470-7 - Influence of sugarcane bagasse saccharification by laccase for fermentative production of biofuels
• Grantee: Camila Abreu Borges da Silva Rabelo
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 15/06246-7 - Biorefinery concept applied to biological wastewater treatment plants: environmental pollution control coupled with material and energy recovery
• Grantee: Marcelo Zaiat
• Support Opportunities: Research Projects - Thematic Grants