A Novel Cold-Adaptive Endo-1,4-β-Glucanase From Burkholderia pyrrocinia JK-SH007: Gene Expression and Characterization of the Enzyme and Mode of Action

Feifei Chen; Feifei Chen; Jianren Ye; Ayyappa Kumar Sista Kameshwar; Xuelian Wu; Jiahong Ren; Wensheng Qin; De-Wei Li; De-Wei Li

doi:10.3389/fmicb.2019.03137

Frontiers in Microbiology (Jan 2020)

A Novel Cold-Adaptive Endo-1,4-β-Glucanase From Burkholderia pyrrocinia JK-SH007: Gene Expression and Characterization of the Enzyme and Mode of Action

Feifei Chen,
Feifei Chen,
Jianren Ye,
Ayyappa Kumar Sista Kameshwar,
Xuelian Wu,
Jiahong Ren,
Wensheng Qin,
De-Wei Li,
De-Wei Li

Affiliations

Feifei Chen: Jiangsu Key Laboratory for Prevention and Management of Invasive Species, Co-innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, China
Feifei Chen: Department of Biology, Lakehead University, Thunder Bay, ON, Canada
Jianren Ye: Jiangsu Key Laboratory for Prevention and Management of Invasive Species, Co-innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, China
Ayyappa Kumar Sista Kameshwar: Department of Biology, Lakehead University, Thunder Bay, ON, Canada
Xuelian Wu: Jiangsu Key Laboratory for Prevention and Management of Invasive Species, Co-innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, China
Jiahong Ren: Department of Biology Science and Technology, Changzhi College, Changzhi, China
Wensheng Qin: Department of Biology, Lakehead University, Thunder Bay, ON, Canada
De-Wei Li: Jiangsu Key Laboratory for Prevention and Management of Invasive Species, Co-innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, China
De-Wei Li: The Connecticut Agricultural Experiment Station, Valley Laboratory, Windsor, CT, United States

DOI: https://doi.org/10.3389/fmicb.2019.03137
Journal volume & issue: Vol. 10

Abstract

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The efficient industrial conversion of plant-derived cellulose to simple sugars and other value-added chemicals requires various highly stable and reactive enzymes. Industrial processes especially synchronous saccharification and fermentation (SSF)-based production of cellulosic bio-ethanol require enzymes that are active at lower temperatures. In this study, we have identified, characterized, and expressed the cold-adaptive endo-1,4-β-glucanase (BpEG) isolated from the Burkholderia pyrrocinia JK-SH007. The analysis of the predicted amino acid sequence indicated that BpEG belongs to GH family 8. The BpEG without the signal peptide was cloned into the expression vector pET32a and significantly expressed in Escherichia coli BL21 (DE3) competent cells. The SDS-PAGE and Western blot analysis of BpEG revealed that the recombinant BpEG was approximately 60 kDa. Purified recombinant BpEG exhibited hydrolytic activity against carboxymethyl cellulose (CMC) and phosphoric acid swollen cellulose (PASC), but not crystalline cellulose and xylan substrates. High performance, anion exchange, chromatography-pulsed amperometric detector (HPAEC-PAD) analysis of the enzymatic products obtained from depolymerization of 1,4-β-linked biopolymers of different lengths revealed an interesting cutting mechanism employed by endoglucanases. The recombinant BpEG exhibited 6.0 of optimum pH and 35°C of optimum temperature, when cultured with CMC substrate. The BpEG enzyme exhibited stable activity between pH 5.0 and 9.0 at 35°C. Interestingly, BpEG retained about 42% of its enzymatic activity at 10°C compared to its optimal temperature. This new cold-adaptive cellulase could potentially achieve synchronous saccharification and fermentation (SSF) making BpEG a promising candidate in the fields of biofuel, biorefining, food and pharmaceutical industries.

Published in Frontiers in Microbiology

ISSN: 1664-302X (Online)
Publisher: Frontiers Media S.A.
Country of publisher: Switzerland
LCC subjects: Science: Microbiology
Website: http://www.frontiersin.org/journals/microbiology

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