Altering the carbon supply used throughout bacterial fermentation—basically, 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 kind protecting layers or biofilms and function helpful supplies for a variety of medical and industrial functions.
“A easy change within the carbon supply dramatically altered the composition, construction, and organic exercise of the bacterial exopolysaccharides,” stated 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, an affordable 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 staff mapped the structural variations among the many ensuing polymers.
The outcomes, printed within the Chemical Engineering Journalon 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 checks. 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 broadly utilized in prescribed drugs, medical coatings, surgical sealants, and drug supply methods due to their biocompatibility, biodegradability, and low toxicity. Nevertheless, understanding the complicated relationship between polysaccharide construction and organic perform 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 similar to sugarcane molasses,” Ibrahim stated.
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 research the molecular mechanisms by which completely different carbon sources regulate EPS biosynthesis, together with the metabolic pathways and genes chargeable for modifications in monosaccharide composition, molecular conformation, and organic exercise,” stated 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 Know-how, 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 grow to be some of the distinguished and complete universities in Japan for the promotion and growth of scholarship and training. Consisting of 12 faculties for undergraduate stage and 5 graduate faculties, starting from pure sciences to humanities and social sciences, the college has grown into some of the distinguished complete analysis universities in Japan. English web site: https://www.hiroshima-u.ac.jp/en
