SUCCINOGLYCAN GUM

Succinoglycan was discovered as a bacterial acidic exopolysaccharide associated with root-nodule bacteria (rhizobia) and plant-microbe interactions. 
Early microbiology and plant-symbiosis studies characterized extracellular polysaccharides required for infection thread formation and root colonization; later structural studies revealed the repeating oligosaccharide backbone and characteristic non-sugar substituents (succinyl, pyruvyl and acetyl). 
Interest in SG as a biopolymer for industrial use grew as researchers and companies explored fermentation production of microbial EPS alternatives to plant gums (e.g., xanthan) because of SG's distinct rheology and formulation compatibility.
CAS number: 73667-50-2.
Synonyms / INCI / Common names: Succinoglycan; Succinoglycan Gum; Succinoglycan EPS; bacterial succinoglycan; exopolysaccharide succinoglycan.

Chemical identity and structure
Monomeric and repeating unit composition
Basic repeating unit: An octasaccharide composed of one galactose (Gal) and seven glucose (Glc) residues, linked primarily by β-glycosidic bonds.
Substituents: Pyruvyl, succinyl and acetyl groups occur at specific positions on the sugar residues; these impart negative charge and influence chain conformation and solubility. 
The presence and degree of substitution vary with producing strain and growth conditions. 

Molecular weight and polydispersity
Succinoglycan is high molecular weight (reported Mw values vary depending on strain and extraction, typical range in literature: hundreds of kDa to several MDa), and exhibits polydispersity influenced by biosynthetic control of polymerization and downstream processing. 
Control of molecular weight is an active area of research because rheological properties strongly depend on chain length and aggregation state. 

Chemical formula and identifiers
Commercial and database entries describe succinoglycan as a polysaccharide (no single small-molecule formula); a representative oligosaccharide fragment appears in PubChem entries for structural reference. CAS Registry Number (73667-50-2) is commonly used in supplier and regulatory listings. 

Molecular conformation and thermodynamic behavior
Double-helix tendencies: Thermal analyses (DSC, CD) and solution studies suggest succinoglycan chains can form ordered double-helical aggregates at ambient temperatures and undergo helix–coil transitions on heating, which influence viscosity and gel strength. 

Hydration and coil expansion: The charged succinyl/pyruvyl groups increase water affinity and electrostatic repulsion, leading to extended coils in dilute solution; counterion concentration (electrolyte) and pH modulate chain dimensions and aggregation. 

Biosynthesis, genetics and producing organisms

Producers: SG is produced by Sinorhizobium (Rhizobium) meliloti, Agrobacterium tumefaciens (formerly Agrobacterium radiobacter), and related soil bacteria. Production is a secondary metabolite process encoded by large EPS biosynthesis loci (exo/upp genes in rhizobia). 
Mutations in regulatory genes can generate SG-overproducing strains. 

Biosynthetic pathway: Assembly of the repeating octasaccharide on lipid carriers, polymerization and export are mediated by glycosyltransferases and secretion systems. 
Degree of substitution (acetylation, succinylation, pyruvylation) is enzyme-controlled and affects polymer charge. 
Genetic engineering strategies can tune yield, polymer length and substitution pattern. 

Production: fermentation, recovery and scale-up
Fermentation

Feedstocks: SG has been produced using defined media with sucrose, glucose or agricultural feedstocks (e.g., date syrup) as carbon sources. 
Fermentation parameters (pH, temperature, aeration, nitrogen source) and strain selection determine yield and substitutions. 

Bioprocess modes: Batch, fed-batch and continuous fermentations have been reported. Overproducing mutants (chemical mutagenesis or targeted genetic modifications) can significantly improve titres. 
Downstream processing and purification

Typical recovery steps: Cell removal (centrifugation/filtration), precipitation (isopropanol/ethanol), dialysis or ultrafiltration to remove low-molecular-weight impurities, drying (spray-drying or freeze-drying). 
Optimization of precipitation and washing minimizes contamination with proteins and nucleic acids. Extraction efficiency and purity strongly influence rheological behavior. 

Commercial production and products
Commercial suppliers sell succinoglycan as “succinoglycan gum” or brand names (e.g., Rheozan® SH) marketed for personal care and formulation uses; supplier data sheets list CAS 73667-50-2 and provide technical specs (viscosity, pH stability, electrolyte tolerance). 

Physicochemical and rheological properties
Solubility and pH/electrolyte tolerance
SG is water-soluble and shows broad pH compatibility (reported compatibility from pH <3 to >12 in some commercial claims), and high tolerance to electrolytes compared with some neutral polysaccharides — properties attributed to its anionic substituents and stable chain conformation. This makes SG suitable for formulations containing salts and acidic or basic actives. 

Viscosity and shear behavior
Non-Newtonian (shear-thinning): SG solutions typically show shear-thinning with high zero-shear viscosity and reduced viscosity at high shear rates; thixotropic recovery depends on concentration, molecular weight and substitutions.

Concentration dependence: Viscosity rises strongly with concentration; gelation or network formation can occur at higher concentrations or in presence of specific ions/conditions. 
Several studies detail the rheological fingerprints (frequency sweeps, flow curves) of SG. 

Gelation and network formation
Some succinoglycans can form weak gels or associative networks via helix-association and hydrogen-bonding; thermal transitions (melting of helical aggregates) change gel strength. 
Additives (multivalent cations, co-polymers) modify gelation behavior and formulation performance.

SAFETY INFORMATION ABOUT SUCCINOGLYCAN GUM

First aid measures:
Description of first aid measures:
General advice:
Consult a physician. 
Show this safety data sheet to the doctor in attendance.
Move out of dangerous area:
 
If inhaled:
If breathed in, move person into fresh air. 
If not breathing, give artificial respiration.
Consult a physician.
In case of skin contact:
Take off contaminated clothing and shoes immediately. 
Wash off with soap and plenty of water.
Consult a physician.
 
In case of eye contact:
Rinse thoroughly with plenty of water for at least 15 minutes and consult a physician.
Continue rinsing eyes during transport to hospital.
 
If swallowed:
Do NOT induce vomiting. 
Never give anything by mouth to an unconscious person. 
Rinse mouth with water. 
Consult a physician.
 
Firefighting measures:
Extinguishing media:
Suitable extinguishing media:
Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.
Special hazards arising from the substance or mixture
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas
 
Advice for firefighters:
Wear self-contained breathing apparatus for firefighting if necessary.
Accidental release measures:
Personal precautions, protective equipment and emergency procedures
Use personal protective equipment. 
 
Avoid breathing vapours, mist or gas. 
Evacuate personnel to safe areas.
 
Environmental precautions:
Prevent further leakage or spillage if safe to do so.
Do not let product enter drains.
Discharge into the environment must be avoided.
 
Methods and materials for containment and cleaning up:
Soak up with inert absorbent material and dispose of as hazardous waste. 
Keep in suitable, closed containers for disposal.
 
Handling and storage:
Precautions for safe handling:
Avoid inhalation of vapour or mist.
 
Conditions for safe storage, including any incompatibilities:
Keep container tightly closed in a dry and well-ventilated place. 
Containers which are opened must be carefully resealed and kept upright to prevent leakage.
Storage class (TRGS 510): 8A: Combustible, corrosive hazardous materials
 
Exposure controls/personal protection:
Control parameters:
Components with workplace control parameters
Contains no substances with occupational exposure limit values.
Exposure controls:
Appropriate engineering controls:
Handle in accordance with good industrial hygiene and safety practice.
Wash hands before breaks and at the end of workday.
 
Personal protective equipment:
Eye/face protection:
Tightly fitting safety goggles. 
Faceshield (8-inch minimum). 
Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).
 
Skin protection:
Handle with gloves. 
Gloves must be inspected prior to use. 
Use proper glove
removal technique (without touching glove's outer surface) to avoid skin contact with this product. 
Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. 
Wash and dry hands.
 
Full contact:
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
Splash contact
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
It should not be construed as offering an approval for any specific use scenario.
 
Body Protection:
Complete suit protecting against chemicals, The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.
Respiratory protection:
Where risk assessment shows air-purifying respirators are appropriate use a fullface respirator with multi-purpose combination (US) or type ABEK (EN 14387) respirator cartridges as a backup to engineering controls. 
 
If the respirator is the sole means of protection, use a full-face supplied air respirator. 
Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).
Control of environmental exposure
Prevent further leakage or spillage if safe to do so. 
Do not let product enter drains.
Discharge into the environment must be avoided.
 
Stability and reactivity:
Chemical stability:
Stable under recommended storage conditions.
Incompatible materials:
Strong oxidizing agents:
Hazardous decomposition products:
Hazardous decomposition products formed under fire conditions. 
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas.
 
Disposal considerations:
Waste treatment methods:
Product:
Offer surplus and non-recyclable solutions to a licensed disposal company. 
Contact a licensed professional waste disposal service to dispose of this material.
Contaminated packaging:
Dispose of as unused product