picture:
Schematic illustration displaying how carbon supply choice influences the construction and organic properties of exopolysaccharides (EPS) produced by Bacillus velezensis AZU-A3. Sucrose-derived EPS (EPS-S) exhibited a mannose- and uronic acid-rich composition with a extra ordered helical-like conformation, whereas sugarcane molasses-derived EPS (EPS-M) confirmed a glucose-rich composition with a extra versatile molecular construction. These substrate-dependent structural variations had been related to enhanced antioxidant and antibacterial actions of EPS-M.
Credit score: Mohamed I. A. Ibrahim / Hiroshima College
Altering the carbon supply used throughout bacterial fermentation—primarily, what micro organism are fed—can considerably affect the properties of the sugar polymers they produce, generally known as bacterial exopolysaccharides (EPSs).
These EPSs are secreted by micro organism into their environment, the place they type protecting layers or biofilms and function priceless supplies for a variety of medical and industrial purposes.
“A easy change within the carbon supply dramatically altered the composition, construction, and organic exercise of the bacterial exopolysaccharides,” mentioned Mohamed Ibrahim, a specifically appointed affiliate professor at Hiroshima College’s Research Institute for Synchrotron Radiation Science (HiSOR) and lead creator of the research.
Researchers at Hiroshima College in contrast the consequences of two distinct carbon substrates—refined sucrose and sugarcane molasses, a cheap agricultural by-product—on the EPSs produced by the bacterium Bacillus velezensis AZU-A3. Utilizing vacuum-ultraviolet round dichroism spectroscopy at Hiroshima College’s HiSOR, along with chromatographic instruments, the group mapped the structural variations among the many ensuing polymers.
The outcomes, revealed within the Chemical Engineering Journal on June 23, 2026, confirmed that refined sucrose yielded a biopolymer (EPS-S) characterised by an ordered, helical-like molecular conformation. Conversely, sugarcane molasses produced a glucose-rich biopolymer (EPS-M) with a extra versatile molecular conformation.
This better structural flexibility allowed the low-cost molasses spinoff to outperform its refined counterpart in organic assessments. The EPS-M demonstrated superior antioxidant capabilities, reaching 94.23% free-radical scavenging exercise, in contrast with 76.43% for EPS-S. It additionally exhibited considerably stronger antibacterial exercise towards frequent pathogenic strains, together with Escherichia coli, Salmonella enterica, and Staphylococcus aureus.
Bacterial EPSs are extensively utilized in prescription drugs, medical coatings, surgical sealants, and drug supply techniques due to their biocompatibility, biodegradability, and low toxicity. Nonetheless, understanding the complicated relationship between polysaccharide construction and organic operate has remained a persistent problem. “Understanding this relationship allows researchers to tailor EPS properties, enhance their antioxidant and antibacterial actions, and develop cost-effective manufacturing strategies utilizing cheap substrates comparable to sugarcane molasses,” Ibrahim mentioned.
These findings provide a sustainable and economically viable strategy to customise biopolymers used within the biomedical, pharmaceutical, and meals industries.
“Our subsequent step is to analyze the molecular mechanisms by which completely different carbon sources regulate EPS biosynthesis, together with the metabolic pathways and genes answerable for adjustments in monosaccharide composition, molecular conformation, and organic exercise,” mentioned Ibrahim.
“We additionally plan to judge these EPSs in additional superior organic fashions and optimize manufacturing utilizing sustainable substrates.”
The research was carried out by Abdelrahman M. Khattab, Mahmoud E. Esmael, Ryota Imaura, Amr A. Nassrallah, Hany A. El-Shemy, Koichi Matsuo, and Mohamed I.A. Ibrahim, researchers from Al-Azhar College, Cairo College, the Egypt-Japan College of Science and Expertise, the Nationwide Institute of Oceanography and Fisheries, and Hiroshima College. Matsuo is a researcher on the International Institute for Sustainability with Knotted Chiral Meta Matter (WPI-SKCM²), the Research Institute for Semiconductor Engineering, and the Analysis Institute for Synchrotron Radiation Science at Hiroshima College, the place Ibrahim additionally serves as a specifically appointed affiliate professor.
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About Hiroshima College
Since its basis in 1949, Hiroshima College has striven to turn out to be one of the crucial distinguished and complete universities in Japan for the promotion and improvement of scholarship and training. Consisting of 12 colleges for undergraduate degree and 5 graduate colleges, starting from pure sciences to humanities and social sciences, the college has grown into one of the crucial distinguished complete analysis universities in Japan. English web site: https://www.hiroshima-u.ac.jp/en
Journal
Chemical Engineering Journal
Article Title
Carbon supply modulates composition, conformation, and exercise of exopolysaccharides from Bacillus velezensis AZU-A3
Article Publication Date
23-Jun-2026
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