Glycosidases

Glycoside hydrolases cleave the bond between a sugar and its aglycone, and in the marine world that single reaction opens up some of the most recalcitrant polysaccharides found anywhere. Agar, carrageenan, fucoidan, laminarin and chitosan are built from unusual sugars and decorated with sulphate or acetyl groups, so the enzymes that act on them rarely behave like their terrestrial counterparts. They tolerate salt, they keep working in cold process streams, and several of them slide along a substrate chain without letting go, releasing oligomers in a controlled pattern rather than a random smear.

Eata Marisource works with marine bacterial and fungal isolates that produce these enzymes, and we supply them in the forms laboratories and production plants actually use: clarified fermentation concentrates, glycerol-stabilised liquids, lyophilised powders, and carrier-bound preparations for repeated cycles. Around them we provide the supporting detail that matters at the bench and on the plant floor, including matched assay conditions and lot-specific activity data.

Sources and how the strains are found

Every product line starts with a sample. We screen seawater, tidal sediment, and the surfaces of brown and red algae, because organisms that live on a polysaccharide-rich surface tend to carry the machinery to break it down. Animal-associated isolates are useful as well: a Bacillus subtilis strain obtained from the gut of a scorpion fish, for example, secreted a chitosanase at 161 units per mg after a two-step purification, with an optimum at pH 5.5 and 60 degrees Celsius.

Screening is substrate-led rather than collection-led. Plates are prepared with the target polysaccharide as the only carbon source, so activity shows up directly and non-producers drop out early.

• Isolation from coastal water, marine sediment, algal thalli and the digestive tract of marine animals.
• Enrichment cultures that use agar, carrageenan, fucoidan, laminarin or chitin as the selective carbon source.
• Activity-guided selection, followed by identification of the responsible gene and its glycoside hydrolase family.

Sediment and seawater samples held for isolation of polysaccharide-degrading marine bacteria.

The enzyme portfolio

Rather than a single catalogue enzyme, we hold a family of related activities that can be selected against the linkage present in a customer substrate. The table gives the working core of the range; closely related variants are available where a different pH optimum or a different product profile is needed.

Reference substrate powders used to map the specificity of a glycosidase preparation.

What a unit of activity means on our paperwork

Two conventions circulate in this field, and the gap between them is close to two orders of magnitude: a micromole of galactose weighs about 180 micrograms, so the same real activity can carry a very different-looking number depending on which basis was used. Some suppliers define a unit by micromoles of reducing sugar released per minute; others quote a microgram-based unit, which is the convention behind the widely traded agarase powders. Both are legitimate, but mixing them silently leads to under-dosing. We state which convention applies to every lot, and where a customer needs the other figure we supply the conversion rather than leaving it to be guessed.

Performance data from characterised marine enzymes

Published work on marine glycosidases shows how widely the operating windows can shift between otherwise similar enzymes. The figures below come from independent strain characterisation studies and illustrate the range we work within when matching an enzyme to a process. Catenovulum agarivorans YM01-3, for instance, carries a GH16 beta-agarase that is stable below 50 degrees Celsius yet still retains about 13 percent of its activity after an hour at 80 degrees Celsius, and it converts agarose mainly into neoagarotetraose and neoagarohexaose.

Working pH and temperature windows

Marine enzymes are not automatically cold-active, but the pool we select from contains both mesophilic and psychrophilic variants, and the choice has real process consequences. A cold-active glycosidase lets a hydrolysis step run at ambient or chilled temperature, which limits colour formation and preserves thermolabile co-products. A thermostable variant is the better answer when the enzyme has to survive a hot feed stream or an extended incubation without refrigeration.

Salts, metal ions and buffer compatibility

Because these enzymes evolved in seawater, many of them are relaxed about high ionic strength, and some are positively stimulated by it. The sensitivity to watch is on the metal side. Divalent cations frequently stabilise the active site, while chelators strip them away and shut the reaction down, which is why an EDTA-containing buffer is a poor choice for a hydrolysis step even when it suits the downstream analysis.

Product formats and specification content

The same enzyme can be supplied as a frozen concentrate, a shelf-stable liquid, a dry powder or a granulated preparation. The decision usually comes down to how the customer doses it. Liquids are easy to meter and disperse instantly; powders travel better and tolerate cold-chain gaps; immobilised preparations pay for themselves when the enzyme is reused across many cycles.

Immobilised and carrier-bound preparations

Attaching a glycosidase to a solid carrier changes the economics of a process line. The enzyme stays in the reactor while the hydrolysate flows through, and a single charge can serve many batches. We screen carriers for pore size, surface chemistry and bead strength, then optimise loading so that the bound activity survives repeated use. For viscous feeds, a packed bed of rigid beads keeps pressure drop predictable, while a fluidised arrangement suits feeds that would otherwise blind a column.

• Covalent and adsorptive immobilisation chemistries, matched to the enzyme surface.
• Bead sizes selected for packed bed or stirred tank operation.
• Reuse testing with retained-activity data across consecutive cycles.

Spherical carrier beads after loading with a marine glycosidase.

From fermenter to finished powder

Recovery starts with clarification. Cells and debris come out first, then the liquor is concentrated and, where needed, fractionated by salt precipitation, ion exchange and membrane steps. The purified pool is then brought into a defined buffer before it is dried or filled. Drying is where a preparation is most easily damaged, so we favour processes that keep the product cool and moving: spray drying for large volumes and fluid bed drying for granulated enzyme powders, in both cases with an inlet temperature chosen to hold the residual activity above the agreed value.

• Solid-liquid separation by centrifugation and filtration, with conditions set to protect enzyme activity.
• Concentration by ultrafiltration, with diafiltration to exchange the enzyme into the final buffer.
• Drying routes kept separate from heat-sensitive products; fluid bed drying for granular powders, freeze drying where the highest specific activity is needed.
• Stabiliser screening before the drying step, since the excipient profile decides how much activity survives.

Fluid bed drying of a granulated enzyme preparation at production scale.

Analytical support and lot documentation

An enzyme is only as good as the number attached to it, so each lot is assayed before it leaves. Reducing-sugar assays are run on the substrate the customer actually uses wherever possible, and where a substrate is too expensive for routine testing we run the standard assay and state that fact on the certificate. High-throughput handling keeps turnaround on multi-lot projects predictable and lets us test a variant panel against several substrates in parallel.

Automated liquid handling used to run parallel activity assays across a variant panel.

Where marine glycosidases earn their place

The largest single use is the controlled cutting of marine polysaccharides into oligomers. Random acid hydrolysis gives a broad mixture and drags colour and salt along with it; an enzyme gives a defined product range at a temperature the rest of the process can tolerate. Away from oligosaccharide work, the same activities show up in molecular biology benches, in biomass pretreatment, and in industrial blends where a salt-tolerant hydrolase outperforms a standard preparation.

Handling, storage and reconstitution

Liquid preparations are the most convenient and also the most fragile. Repeated freeze-thaw cycles gradually reduce activity, so aliquoting a working stock is worth the ten minutes it takes. Powders are more forgiving but hygroscopic; they should be brought to room temperature in a sealed container before opening so that condensation does not form on the surface of the solid. Buffers should be chosen with the compatibility table above in mind, and glassware used for dilutions kept free of detergent residue.

• Store liquids at 2 to 8 °C or at minus 20 °C as stated on the label, and avoid repeated freeze-thaw.
• Keep powders dry and sealed; use the reconstitution volume given on the batch sheet.
• Equilibrate to the assay temperature before adding enzyme; a cold aliquot added to a warm substrate can under-read by a wide margin.
• Record the lot number against the process run, since activity varies slightly between lots.

Liquid enzyme concentrate filled into plain HDPE pails ahead of shipment.

Custom development and tailored biocatalysts

Many projects need an enzyme that does not exist off the shelf: an activity against an unusual linkage, a variant that survives an aggressive buffer, or a preparation matched to an existing dosing line. Our development programme covers the full path from sample to bulk supply, and it can be entered at any stage. A customer who already holds a gene can hand it over for expression and scale-up; a customer who holds only a substrate can start with screening.

Send us the substrate, the target product profile and the process window you are working with, and we will come back with a recommended enzyme and the assay conditions that go with it.

For Research or Industrial Raw Materials, Not For Personal Medical Use!