Harnessing enzymes from marine microorganisms: Opening pathways for transforming sulphated polysaccharides rich in biological value
From potential raw materials to solutions through enzyme biotechnology
Vietnam possesses a rich marine ecosystem, in which seaweeds and invertebrates such as sea cucumbers and sea urchins contain large amounts of sulphated polysaccharides. Compounds such as fucoidan, ulvan and sulphated chondroitin have been shown to possess immunomodulatory and anti-inflammatory properties, with broad potential applications in biomedicine. However, due to their complex structures, the effective extraction and transformation of these compounds remain major challenges for marine biotechnology.
In response to this need, the Laboratory of Analytical Chemistry and Technology Development (Institute of Oceanography) has carried out in-depth research focusing on extraction, structural analysis and screening of indigenous marine microorganisms capable of producing transformation enzymes. Compared with traditional chemical methods, enzyme technology allows selective targeting of specific structures, reduces the use of toxic chemicals and generates products with high biological activity, suitable for pharmaceuticals and functional foods.
From a “microbial bank” to valuable bio-enzymes
Dr Cao Thi Thuy Hang and her research team at the Institute of Oceanography have implemented the project “Study on the ability to produce enzymes for transforming sulphated polysaccharides derived from marine organisms from the collection of culturable marine microorganisms in Vietnam” (Code: KHCBBI.01/21-23), aiming to exploit indigenous marine microbial resources and develop enzymes capable of converting sulphated polysaccharides into oligosaccharides with high biological activity.
Assoc. Prof. Dr Tran Thi Thanh Van and Dr Cao Thi Thuy Hang (right) discussing research results
A key advantage of the study is the use of the Collection of Culturable Marine Microorganisms (NCMM), comprising more than 2,000 strains of marine bacteria and fungi, providing a foundation for screening rare enzymes such as fucoidanase and ulvan lyase. The research team applied interdisciplinary approaches, from field surveys and sampling of seaweeds and sea cucumbers in the Nha Trang sea area, to processing, classification and preservation under strict protocols.
Collection of seaweed samples in the waters of Khanh Hoa for fucoidan extraction and as a source for isolating marine microorganisms
From the collected samples, the team successfully extracted polysaccharides such as fucoidan and ulvan, and analysed their structures using modern techniques, forming the basis for screening microbial strains capable of transformation. Promising strains were further identified through gene sequencing and genomic analysis, while target enzymes were studied through optimisation of fermentation, purification and evaluation of catalytic properties.
Process of extracting sulphated polysaccharides from brown algae, green algae and sea cucumbers
From screening to enzyme characterisation
From the collection of culturable marine microorganisms, the team identified 22 potential strains (17 bacteria and 5 fungi) capable of producing enzymes that transform fucoidan and ulvan. These strains were identified and their gene sequences registered on GenBank, contributing to enriching the genetic database of marine microorganisms in Viet Nam. Notably, the team decoded the genomes of four bacterial strains, discovering multiple enzyme-encoding genes, including, for the first time, the identification of a fucoidanase gene in the strain Halomonas cupida.
Genome sequencing and analysis of marine bacterial strain 0522KB3.1
Representative enzymes were purified and their catalytic properties such as temperature, pH, salinity and the effects of metal ions, were characterised, indicating that the research has progressed beyond the initial screening stage. According to Dr Cao Thi Thuy Hang, the greatest challenge lies in maintaining enzyme activity during purification due to sensitivity to environmental conditions. The results not only affirm the potential of marine microorganisms in Viet Nam as a source of specialised enzymes, but also provide a foundation for the future development of recombinant enzymes.
Translated by Tuyet Nhung
Link to Vietnamese version
