Extracellular
expression of scaffoldin mini-CipA from Clostridium thermocellum by Bacillus subtilis
Nguyen Hoang Ngoc Phuong, Phan Thi Phuong Trang, Tran Linh Thuoc and Nguyen Duc
Hoang
Res. J. Biotech.; Vol. 20(5); 191-200;
doi: https://doi.org/10.25303/205rjbt1910200; (2025)
Abstract
One of the strategies for producing bioproducts from the abundant plant biomass
is designing cell factories for consolidated bioprocessing. Clostridium thermocellum
(Acetivibrio thermocellus), an anaerobic and thermophilic bacterium, secrets protein
complexes called cellulosomes which can degrade low-accessibility lignocellulose
due to synergistic activities from multi-functional cellulosomal enzymes. Scaffoldin
CipA is a primary structural component of the cellulosome from C. thermocellum which
is responsible for the assembly of cellulosomal enzymes on plant cell walls and
the attachment of the cellulosome to carbohydrate fibers.
This research focused on designing a truncated extracellular scaffoldin CipA, called
mini-CipA, by cloning it in Escherichia coli and expressing it extracellularly in
Bacillus subtilis WB800N. This safe facultative aerobic probiotic can multiply to
high cell density on inexpensive substrates. SDS-PAGE and Western blot analyses
of the culture media of Bacillus subtilis expressing mini-CipA showed bands lower
than 100 kDa which were consistent with the theoretical molecular weight of mini-CipA.
Additionally, ten peptides from mini-CipA were detected using High-performance liquid
chromatography - tandem mass spectrometry. The number of detected proteins in the
secretome of Bacillus subtilis expressing mini-CipA was approximately 30% of those
in the control sample.
