Tannase

Tannase (Tannin Acyl Hydrolase, EC 3.1.1.20)

Identity and Chemical Characterization

Nomenclature and Classification

Tannase belongs to the family of hydrolases, specifically those acting on carboxylic ester bonds. Its systematic name is tannin acylhydrolase. Other names in common use include tannase S and tannin acetylhydrolase. The enzyme is classified under EC 3.1.1.20 and functions as an esterase able to liberate gallic acid from aromatic-sugar complexes. It is a key enzyme in the degradation of gallotannins and ellagitannins — two types of hydrolysable tannins — specifically catalyzing the hydrolysis of ester and depside bonds of hydrolysable tannins to release glucose and gallic or ellagic acid.

Tannase is a natural adaptive intracellular/extracellular inducible hydrolase placed in the esterase superfamily. Fungal tannases have been classified within the feruloyl esterase (EC 3.1.1.73) subclass of carboxylic acid esterases, though only a few fungal tannases have been characterized in depth.

Natural Sources

Tannases have been identified from bacteria, fungi, yeast, and plants. Tannin acyl hydrolases, also known as tannases, are a group of enzymes critical for the transformation of tannins. The study of these enzymes, which initially evolved in different organisms to detoxify and/or use these plant metabolites, has become relevant in microbial enzymology research due to their role in food tannin transformation.

• Fungi: Several fungi, such as Penicillium, Aspergillus, Fusarium, Rhizopus, Trichoderma, Candida, and Saccharomyces, are commonly explored for tannase enzyme production. One source of the enzyme is the growth of certain molds belonging to the genus Aspergillus or Penicillium. For example, Aspergillus flavus grown on a medium containing tannic acid as a sole carbon source provides tannase in substantial amounts. Two specific strains known to produce substantial quantities of tannase are Aspergillus oryzae ATCC No. 9362 and Aspergillus niger ATCC No. 16888.
• Bacteria: Microorganisms, particularly bacteria, are major sources of tannase. After the discovery of bacterial tannase in 1983, several studies on bacterial tannase were published. Notable bacterial sources include species within the genera Lactobacillus, Streptococcus, Bacillus, Clostridium, and Fusobacterium.
• Lactic Acid Bacteria (LAB): Lactobacillus pentosus BA-7 and L. pentosus QA1-5 are tannin-tolerant lactic acid bacteria that were isolated from Miang, a traditional fermented tea-leaf found in northern Thailand and a tannin-rich substrate. The first indication of bacterial tannase was reported in Streptococcus gallolyticus and Lonepinella koalarum found in the alimentary tract of koalas feeding on tannin-rich eucalyptus leaves, implying a possible symbiotic relationship between the animal and these bacteria.
• Yeasts: Fungi, bacteria, and their tannases have been well documented for their potential bioconversion and specifically for the biotransformation of tannic acid to gallic acid. Sporidiobolus ruineniae A45.2 is a pigment-producing and tannase-producing yeast that has gained interest for use as an additive in animal feed.
• Gut Microbiota: Tannase is a core enzyme in human microbiota, which degrades tannic acid into downstream metabolites, among which gallic acid is the main one in most cases.

Physical and Chemical Properties

Tannases have a vast molecular weight range of 31–310 kDa; furthermore, they have stability to work in broad ranges of pH (3–10) and temperature (30–70°C). All tannases from yeast and fungi are glycoproteins, but there appears to be no such post-translational modification in bacteria. It has been reported that the activities of tannases from Arxula adeninivorans, Penicillium chrysogenum, and Aspergillus flavus are inhibited completely by phenylmethylsulfonyl fluoride, indicating that the tannase is a serine enzyme which requires a serine residue for its catalytic function.

Tannases are serine hydrolases found within the α/β-hydrolase superfamily and usually possess a Ser–His–Asp catalytic triad. Here, the serine, located in a pentapeptide "nucleophilic elbow" motif, acts as nucleophile, the histidine as a general acid and base, and the carboxylic acid correctly positions the histidine and reduces its charge. Hydrogen bonds between the hydroxyl groups of the galloyl-containing substrate and (typically) Asp/Lys/Glu active site residues hold the substrate in place for hydrolysis.

Purified native and recombinant tannases from Aspergillus oryzae had an optimum pH of 4.0–5.0 and 5.0, respectively, and were stable up to 40°C. A novel bacterial tannase from Lachnospiraceae exhibited maximal activity at pH 7.0 and 50°C, and it maintained more than 70% relative activity from 30°C to 55°C. The activity was enhanced by Mg²⁺ and Ca²⁺ and was dramatically reduced by Cu²⁺ and Mn²⁺.

Historical Discovery and Traditional Context

Scientific Discovery

Since the discovery of tannase in 1867, a great deal of research has happened on production aspects of tannase. Most of the early research was focused on fungal tannase, as tannin was earlier considered bacteriostatic. In the early 1970s, several patents were filed for potential application of tannase in the food and beverage industry. Juelich Chiral Solutions GmbH (Germany) in Europe was the first company that commercialized tannase in extract form.

Traditional and Ethnocultural Context

Tannase as a purified or isolated supplement is a modern biotechnological product with no direct history of traditional medicinal use as an isolated enzyme. However, its substrate — tannins — and tannase-producing microorganisms have participated in traditional food fermentation practices for centuries. Lactobacillus pentosus strains with tannase activity were isolated from Miang, a traditional fermented tea-leaf found in northern Thailand. This traditional fermented product represents one of the oldest known environments where tannase-producing bacteria naturally occur in a food context. Three medicinal herbs traditionally used to treat gastrointestinal diseases are rich in tannins, namely agrimony herb, strawberry leaves, and raspberry leaves. The enzymatic breakdown of tannins within these traditional preparations by endogenous microbial tannase would have contributed, unknowingly, to their historical use, though this was not recognized as an enzyme-specific activity until the modern era.

In the food industry, tannase is used for the production of instant tea, in addition to being used to improve the quality of beverages such as fruit juices, beer, and wine. This industrial use took shape from the mid-twentieth century onward, grounded in scientific rather than folk knowledge.

Key Constituents, Active Compounds, and Mechanisms of Action

Primary Reaction and Substrates

Tannin, the natural substrate of tannase, is widespread in the plant kingdom, found in many edible fruits and vegetables; tannins are nutritionally undesirable as they form complexes with protein, starch and digestive enzymes, causing a reduction in nutritional value of food. Tannase's mode of action is dividing the ester and depside bonds of the hydrolysable tannins to release glucose and gallic acid. As a result, tannase is one of the main sources of gallic acid.

The initial hydrolysis of tannins is performed by tannases, which catalyze the hydrolysis of ester and depside linkages in tannins to release, e.g., gallic acid, catechin, and glucose. Tannases have been used in hydrolysis of gallotannins or more complex natural sources such as green tea, which leads to the release of gallic acid and epigallocatechin.

Gallic Acid as a Principal Downstream Active Compound

Gallic acid (GA) and pyrogallol (PG) are bioactive compounds displaying diverse biological properties, including carcinogenic-inhibiting activities. Gallic acid, a product of tannin degradation, has been found to possess a range of biological activities, such as anticarcinogenic, antiallergic, antibacterial, anti-inflammatory, and antioxidant properties. Tannase (tannin acylhydrolase) transforms the gallate esters of tannins and other phenolic compounds, such as epigallocatechin gallate, into gallic acid. Gallic acid can, subsequently, be decarboxylated by gallate decarboxylase to yield pyrogallol as a final product of tannin metabolism.

Gallic acid has mainly been used in the pharmaceutical industry for the production of trimethoprim, an antibacterial agent, and gallate esters that are used as preservatives in the food production industry. Gallic acid has received significant interest in terms of its biological properties, particularly for its antioxidant, antibacterial, anticarcinogenic, antiallergic, and anti-inflammatory activities.

Tannase and EGCG Hydrolysis

Epigallocatechin gallate (EGCG) and other catechin galloyl esters bind with food ingredients (i.e., proteins) to form a complex that is likely to be unabsorbable through the intestinal wall, whereas most catechins not esterified with gallic acid remain in free form. Tannase activity of L. plantarum is strain dependent, with high-activity strains capable of hydrolyzing not only intact EGCG but also EGCG and other catechin galloyl esters complexed with dietary proteins to free non-galloyl ester catechins and gallic acid.

Enzymes like tannase and hydrolase could convert EGCG and ECG to EGC and EC, respectively, and biotransformed green tea catechins exhibited significantly higher antioxidant activity. The addition of green tea extract to the enzyme reaction resulted in a significant increase in degallated catechins, including gallic acid (a product of the tannase reaction — rising from 314.5 µg/mL to 4076.0 µg/mL — and a reduction in EGCG). Biotransformation of catechins improved the radical scavenging activity of the extract.

Anti-Nutritional Factor Reduction

Because they precipitate proteins, block digestive enzymes, and alter the utilization of vitamins and minerals, tannins are regarded as nutritionally undesirable and are treated as antimicrobial compounds. The molar mass of tannin molecules directly influences the features of tannins; it has been observed that the stronger the antinutritional effects and the lower the biological activities of tannins, the higher their molecular mass. Tannase, by cleaving the ester and depside bonds of these tannins, degrades them into smaller, less inhibitory products.

Microbiome-Mediated Biotransformation

Microbiota-mediated hydrolysis of tannins produces highly bioaccessible metabolites, which have been extensively studied and account for most of the health effects attributed to tannins. Under the influence of many bacterial enzymes, hydrolysable tannins are broken down into gallic acid, pyrogallol, and phloroglucinol and eventually to acetate and butyrate. The tannase enzyme, produced by different bacterial groups, has the ability to hydrolyze and degrade gallotannins, but the effect of this enzyme is restricted to the hydrolysis of galloyl residues on the hexahydroxydiphenoyl moiety of ellagitannins.

The prebiotic action of polyphenols on the gut microbiota may directly stem from the activation of enzymes like tannase, quercetinase, gallate decarboxylase, esterase, and phenolic acid decarboxylase, leading to both the generation of bioaccessible phenolic metabolites and microbial cross-feeding interactions in the gut.

Scientific Evidence by Area of Use

1. Food Processing and Beverage Quality

The best-documented industrial application of tannase is in food and beverage processing. Tannase is used in the manufacture of instant tea and in the production of gallic acid. The elevated tannin content in fruit juices is the reason for haze and sediment formation, which deteriorates their quality upon storage. In the case of tea, the high tannin content is responsible for tea cream formation when it is kept at or below 4°C, which lowers the solubility of tea in cold water and hinders the manufacturing of instant tea. Similarly, tannins are also responsible for the deterioration of beer quality due to haze formation after storage.

Tannase can catalyze the hydrolysis of ester and depside bonds in hydrolyzed tannins or gallates, releasing glucose and gallic acid. The gallic acid produced can compete with phenolic compounds to bind with caffeine and reduce the turbidity of tea beverages, in addition to improving flavor, reducing bitterness, and enhancing antioxidant capacity.

A study on pomegranate juice illustrates the biotransformation capabilities of tannase in a food matrix: Under optimal conditions (33.9 U/100 mL tannase, 30°C, 90-minute reaction time), the punicalagin content decreased by 27.8%, while the ellagic acid and gallic acid levels increased by 24.2% and 32.3%, respectively, effectively reducing astringency. Under these conditions, the total phenolic content reached 110 mg/100 g, with a free radical scavenging capacity of 69.8%, significantly enhancing the juice's antioxidant properties.

Evidence strength: Strong preclinical and process-level evidence for food and beverage applications. These are established, well-characterized industrial uses supported by decades of research and regulatory review.

2. Antioxidant Properties (In Vitro and Preclinical)

It has been shown that tannase-treated green tea shows higher antioxidant properties than normal green and black tea. Tannase-treated green tea effectively inhibits N-nitrosamines, which are carcinogenic, mutagenic, and teratogenic compounds found in most preserved meats. Several studies also reported better color stability and organoleptic properties in tannase-treated green tea.

The enzyme reduced the total tannin content in all tannin-rich substrates after 12 hours. The resulting gallic acid had total phenols of 77.75 ppm and antioxidant activity of 82.91%.

After exposure to the unprocessed enzyme tannase, black tea's antioxidant activity increased by 52.31% from its baseline activity, and the total phenolic content increased to 12.48 mg GAE/g (dry weight).

Evidence strength: These findings are based on in vitro laboratory studies and food-processing experiments. No controlled human clinical trials on tannase supplementation as an antioxidant intervention have been identified in the literature reviewed.

3. Gut Microbiome and Gastrointestinal Health

Tannase is a core enzyme in human microbiota, which degrades tannic acid into downstream metabolites, among which gallic acid is the main one. Tannic acid exerts its function through producing gallic acid by intestinal microbiota in a dose- and time-dependent manner.

Oral and intestinal tannases could contribute to tannin digestion. At least five different species of oral or intestinal bacteria have been described to possess active tannases, including A. parvulum, L. plantarum, S. gallolyticus, S. lugdunensis, and Fusobacterium nucleatum subsp. polymorphum.

The capacity for tannin degradation is a survival advantage over other gut microorganisms because tannins display antimicrobial activity and reduce species richness in the gut. This capacity probably improves the adaptation of tannin-degrading bacteria to the intestinal environment.

Research in mouse models showed that green tea powder alone, or in combination with L. plantarum DSM 15313 (a tannase-active strain), exerts beneficial metabolic effects in C57BL/6J mice fed a high-fat diet. When a tannase-active strain of L. plantarum was supplemented to the green tea diet, both the load of lactobacilli and the bacterial diversity increased significantly in the small intestine. The authors proposed that green tea acts as a potent source for dietary polyphenols, promoting the growth of a healthy, anti-inflammatory intestinal microbiota, and that addition of a tannase-active strain of L. plantarum results in certain synbiotic effects.

Evidence strength: Primarily mechanistic, in vitro, and animal-model evidence. Human studies on tannase per se as a supplement for gut health are lacking; most evidence pertains to the role of endogenous microbial tannase in the gut ecosystem.

4. Inflammatory Bowel Disease (IBD) and Colorectal Cancer — Emerging Research

The amount of tannic acid was associated with the outcomes of dextran sulfate sodium (DSS)-induced IBD in both in vivo and in vitro studies. Metabolomic and metagenomic analyses revealed that tannic acid-induced enrichment of the microbial metabolite gallic acid was responsible for the action. Mechanistically, a protective dose of gallic acid promoted colonic mucus secretion to suppress bacterial infection and ameliorated DSS-induced epithelial damage by inhibiting p53 signaling, whereas a toxic dose of gallic acid directly caused epithelial damage by promoting cell cycle arrest. A therapeutic experiment showed that a protective dose of gallic acid promoted recovery of DSS-induced colonic inflammation.

The role of tannase-containing bacteria can be transformed under different conditions in IBD progression. This underscores the complexity of dose-dependency and context-specificity in gut tannase activity.

The microorganisms in the human gastrointestinal tract have a profound influence on the transformation of food into metabolites which can impact human health. Gallic acid and pyrogallol are bioactive compounds displaying diverse biological properties, including carcinogenic-inhibiting activities. A review highlighted tannase as an underlying gene function of bacterial species that selectively colonize tumorous tissues, but not adjacent non-malignant tissues. Given the anti-carcinogenic roles of gallic acid and pyrogallol produced by gut tannin-degrading bacteria, the possible consequences of this intriguing coincidence for colorectal cancer development were discussed.

As tannase-producing bacteria have been identified in several human cancer microbiomes, the study of the association between dietary tannin intake and tumor recurrence or regression may be critical in understanding the role of gut bacteria in the anti-cancer effects of dietary polyphenols.

Evidence strength: Highly preliminary. The relationship between tannase-producing gut bacteria, their metabolites, and colorectal cancer is an emerging field. All current evidence is from mechanistic reviews, in vitro cell studies, and animal models. No human clinical trials directly addressing tannase supplementation in IBD or colorectal cancer have been identified.

5. Antimicrobial Properties (via Gallic Acid Production)

Tannase catalyzes tannins to produce gallic acid (also known as 3,4,5-trihydroxybenzoic acid) as a byproduct, which has demonstrated antibacterial, antifungal, anticancer, antiviral, and antioxidant properties. Recent reports have revealed that proper minimum concentrations of gallic acid exhibit antimicrobial activity against human and animal pathogenic bacteria including Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus.

The gallic acid minimum inhibitory concentration (MIC) values ranged from 7770.0 to 121.41 µg/mL. The obtained gallic acid showed a bactericidal effect against all bacterial strains except Shigella sonnei DSM5570 and Salmonella typhi DSM17058, which showed bacteriostatic behavior.

Evidence strength: In vitro only. These findings reflect the antimicrobial properties of the gallic acid that tannase generates, not of tannase itself as a direct antimicrobial agent. No human clinical trials have tested tannase supplementation for antimicrobial outcomes.

6. Animal Feed and Nutrient Bioavailability (Preclinical)

The enzymatic method utilizes enzyme preparations such as protease, NSPs enzyme, phytase, and tannase to degrade anti-nutritional factors (ANFs) and thus reduce their content in animal feeds. Tannins have long been known to be an "anti-nutritional agent" in monogastric and poultry animals. Using appropriate application protocols, researchers have observed positive effects on the intestinal microbial ecosystem, gut health, and animal production.

In one study examining tannase supplementation in lactating goats (using a commercial tannase preparation, "Tanozym"): Tanozym supplementation significantly (p<0.05) increased nutrient digestibility, nutritive values, and ruminal total volatile fatty acids (TVFAs), but insignificantly increased ammonia nitrogen (NH₃-N). Lower significant (p<0.05) values of rumen pH were recorded for treated groups compared to the control. Blood serum of animals fed Tanozym had higher values of total protein, albumin, globulin, total lipids, urea, and glucose but lower values of AST and ALT compared to controls. Daily milk yield, SNF, lactose, and ash yield were significantly (p<0.05) increased with Tanozym compared to the control group.

Treatment of pomegranate peel with tannin-degrading bacteria is a proper way to reduce tannin, thus improving the nutritional value of the peel for ruminants.

Evidence strength: Animal studies (ruminants, poultry) provide the strongest preclinical evidence for tannase's utility in reducing anti-nutritional effects of tannins in feed. These findings have direct agronomic relevance but cannot be extrapolated directly to human supplementation outcomes.

7. Gallic Acid Production for Pharmaceutical Applications

The availability of various agro-industrial residues provides a way for maximum utilization of tannase production for the degradation of tannin and eventually the production of gallic acid. Gallic acid production and instant tea processing represent tannase's main industrial uses. Gallic acid is frequently used as a component of a developer in printing inks and photography. Additionally, it serves as a precursor for the industrial manufacturing of certain dyestuffs, propyl gallate (a food preservative), and the antimicrobial medication trimethoprim.

Gallic acid, one of the crucial industrial and therapeutically significant molecules with a demand of over 10,000 tons per year, can be produced by tannase in various ways.

Body Systems and Health Areas Associated with Tannase

• Gastrointestinal system: Tannase-producing gut microbiota convert dietary tannins into bioaccessible metabolites. Microbiota-mediated hydrolysis of tannins produces highly bioaccessible metabolites, which account for most of the health effects attributed to tannins.
• Immune and inflammatory pathways: Despite their low bioavailability, tannins have many beneficial pharmacological effects, such as anti-inflammatory, antioxidant, antidiabetic, anticancer, and cardioprotective effects. These effects are mediated in part by tannase-driven metabolic conversion.
• Microbiome ecology: Current global research is focused on identifying Generally Recognized as Safe (GRAS) category microbes capable of producing phytase and tannase to ensure their safety in human applications.
• Antioxidant defense: Tannase-generated gallic acid contributes to radical scavenging capacity in food matrices and, by extension, potentially in biological systems after ingestion.
• Nutritional absorption: By degrading tannins that would otherwise bind proteins, starch, and digestive enzymes, tannase activity enhances nutrient bioavailability in tannin-rich foods. Tannase could be used to reduce the negative effects of tannins in beverages, food, feed, and tannery effluents, and for the production of gallic acid from tannin-rich materials.
• Colorectal mucosa (emerging): Gallic acid and pyrogallol can be generated as final products of tannin metabolism by microbes endowed with tannase, which opens up the possibility of their anti-cancer potential being increased.

Dosage Forms and Reported Dosages

Tannase as a standalone dietary supplement for direct human consumption is not yet a standardized product with established clinical dosing guidelines. It is encountered primarily in four contexts: as a food-processing enzyme, as a component of probiotic formulations through tannase-producing bacteria, in animal feed supplements, and in experimental research preparations.

• Food-processing applications: In pomegranate juice processing, the effects of tannase concentration, reaction time, and temperature on deastringency were evaluated. Under optimal conditions of 33.9 U/100 mL tannase, 30°C, and a 90-minute reaction time, punicalagin content decreased by 27.8%.
• Animal feed (research): Pre-dried wheat straw was treated with different concentrations of tannase (0.1%–0.3% w/w with an activity of 5.8 IU/mg) to remove tannins. Lyophilized tannase was dissolved in citrate phosphate buffer, sprayed on the substrate to obtain a moisture ratio of 1:2, and then incubated at 40°C under static conditions for 6.0 hours.
• Regulatory dietary exposure estimate: Dietary exposure from food-enzyme use was estimated to be up to 0.310 mg total organic solids (TOS)/kg body weight per day in European populations.
• Common preparations: Tannin acyl hydrolase (tannase) has important applications in several science and technology fields. Due to its hydrolytic and synthetic properties, tannase could be used to reduce the negative effects of tannins in beverages, food, feed, and tannery effluents, for the production of gallic acid from tannin-rich materials, the elucidation of tannin structure, and the synthesis of gallic acid esters in nonaqueous media.

No human clinical trials establishing therapeutic oral doses of purified tannase enzyme as a dietary supplement have been identified in the peer-reviewed literature reviewed for this article. Dosage data in this section reflects only what was reported in the cited process-level and animal studies.

Safety Considerations and Interactions

Regulatory Safety Assessment (EFSA)

The food enzyme tannase (tannin acylhydrolase; EC 3.1.1.20) produced with the non-genetically modified Aspergillus sp. strain TAN 206 by Shin Nihon Chemical Co., Ltd. has been subject to formal safety evaluation by the European Food Safety Authority (EFSA).

Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level (NOAEL) of 770 mg TOS/kg body weight per day — the highest dose tested — which, when compared with the estimated dietary exposure, resulted in a margin of exposure of at least 2484.

A search for homology of the amino acid sequence of the tannase to known allergens was made and no match was found. The Panel considered that a risk of allergic reactions upon dietary exposure to the food enzyme cannot be excluded, but that the likelihood is low. Based on the data provided, the Panel concludes that this food enzyme does not give rise to safety concerns under the intended conditions of use.

No reports on oral or respiratory sensitization reactions to the tannase under assessment have been published. No allergic reactions upon dietary exposure to any tannase have been reported in the literature.

Dose-Dependent Effects on Gut Tannin Metabolism

A significant safety and pharmacodynamic nuance emerges from research on tannase-containing gut bacteria and IBD: a protective dose of gallic acid (produced via tannase activity) promoted colonic mucus secretion to suppress bacterial infection and ameliorated DSS-induced epithelial damage by inhibiting p53 signaling, whereas a toxic dose of gallic acid directly caused epithelial damage by promoting cell cycle arrest. This bifurcated dose-response indicates that the downstream metabolites of tannase activity are not unconditionally beneficial and that dose context matters substantially.

GRAS Status and Microorganism Safety

The utilization of microbes and their derived enzymes as food supplements remains a safety concern. While phytase was originally employed to enhance phosphate uptake in livestock animals, recent studies have explained its potential in addressing human nutrition by improving the bioavailability of essential minerals and ions. Therefore, considerable efforts are being directed toward identifying enzyme-producing strains that are safe for human consumption. This highlights the need for safe, food-based interventions. Current global research is focused on identifying Generally Recognized as Safe (GRAS) category microbes capable of producing phytase and tannase to ensure their safety in human applications.

Interactions with Dietary Compounds

Tannase directly modifies the chemical composition of tannin-rich foods and thus has the potential to alter the bioavailability of co-ingested nutrients and phytochemicals. Tannase-producing Lactobacillus plantarum strains capable of hydrolyzing EGCG and other catechin galloyl esters complexed with dietary proteins release free non-galloyl ester catechins and gallic acid. This activity changes the form in which tea polyphenols circulate and interact in the gastrointestinal environment, which has implications for how tannin-rich supplements and tannase might interact when co-administered.

Gallic acid, the principal product of tannase activity, serves as a precursor for the industrial manufacturing of propyl gallate (a food preservative) and the antimicrobial medication trimethoprim. The structural relationship between gallic acid and trimethoprim means that high-level tannase-mediated gallic acid production in the gut has theoretical implications for interactions with antimicrobial drug metabolism, though no clinical interaction studies have been identified.

Evidence Gaps and Research Limitations

Microbiological studies suggest that tannase may play a role in gut health by facilitating the breakdown of dietary tannins, although human clinical trials are limited. Large-scale, well-controlled human studies are still needed to fully validate health claims associated with tannase in nutritional products.

Tannase has great application potential, but in practical application, due to low expression, high cost, and complex purification and recovery, these factors seriously restrict the wide application and industrial development of tannase.

References

• Rivas B, et al. Bacterial tannases: classification and biochemical properties. Appl Microbiol Biotechnol. 2019. PubMed.
• Tannase — Overview. ScienceDirect Topics (Agricultural and Biological Sciences).
• Chandran A, et al. A comprehensive review on tannase: Microbes associated production of tannase exploiting tannin rich agro-industrial wastes. PubMed. 2021.
• Ristinmaa AS, et al. Structural diversity and substrate preferences of three tannase enzymes encoded by Clostridium butyricum. J Biol Chem. 2022.
• Expression and biochemical characterization of a new alkaline tannase from Lactobacillus pentosus. PubMed. 2019.
• Identification of a highly active tannase from Fusobacterium nucleatum subsp. polymorphum. PubMed. 2018.
• Exploration of Mangrove Endophytes as Novel Sources of Tannase Producing Fungi. PMC.
• Rodríguez-Durán LV, et al. Novel strategies for upstream and downstream processing of tannin acyl hydrolase. Enzyme Res. 2011. PubMed.
• Tannase. Wikipedia.
• Safety evaluation of the food enzyme tannase from Aspergillus sp. strain TAN 206. PMC/EFSA Journal. 2025.
• EFSA Panel. Safety evaluation of the food enzyme tannase from Aspergillus sp. strain TAN 206. EFSA Journal. 2025.
• Effect of Gut Microbiota Biotransformation on Dietary Tannins and Human Health Implications. Microorganisms. 2021.
• López de Felipe F, et al. Bioactive compounds produced by gut microbial tannase: implications for colorectal cancer development. Front Microbiol. 2014. PMC.
• Identification of a highly active tannase from Fusobacterium nucleatum subsp. polymorphum. Microbial Cell Factories. 2018.
• Tannins amount determines whether tannase-containing bacteria are probiotic or pathogenic in IBD. PubMed. 2023.
• Tannins amount determines whether tannase-containing bacteria are probiotic or pathogenic in IBD. PMC. 2023.
• Polyphenol-Mediated Gut Microbiota Modulation: Toward Prebiotics and Further. Frontiers in Nutrition. 2021.
• Effect of Gut Microbiota Biotransformation on Dietary Tannins and Human Health Implications. PMC. 2021.
• Tannase and Its Applications in Food Processing: Enzymes in Industrial Food Processing. ResearchGate.
• Recent Advances in Industrial Application of Tannases: A Review. Recent Patents on Biotechnology. 2013.
• Microbial Production of Tannase: State of the Art. Scialert. 2011.
• A novel tannase from Klebsiella pneumoniae KP715242 reduces haze in fruit juice. Frontiers in Sustainable Food Systems. 2023.
• Recent Advances of Tannase: Production, Characterization, Purification, and Application in the Tea Industry. Foods. 2025. MDPI.
• Characterization and application of tannase and gallic acid produced by co-fungi of Aspergillus niger and Trichoderma viride. Scientific Reports. 2023.
• Characterization and application of tannase and gallic acid produced by co-fungi of Aspergillus niger and Trichoderma viride. PMC. 2023.
• Co-production of gallic acid and a novel cell-associated tannase by Sporidiobolus ruineniae A45.2. PMC. 2020.
• Complexing of Green Tea Catechins with Food Constituents and Degradation by Lactobacillus plantarum. PMC. 2012.
• Green tea powder and Lactobacillus plantarum affect gut microbiota, lipid metabolism and inflammation in high-fat fed mice. PMC. 2012.
• Comparison of three tannases cloned from Lactobacillus plantarum, L. paraplantarum, and L. pentosus. PMC. 2014.
• Use of tannase-producing bacteria isolated from the rumen to improve the nutritional value of pomegranate peel for fattening lambs. PMC. 2024.
• Treatment of wheat straw using tannase and white-rot fungus to improve feed utilization by ruminants. PMC. 2014.
• Biochemical and Structural Characterization of a Novel Bacterial Tannase From Lachnospiraceae bacterium in Ruminant Gastrointestinal Tract. PMC. 2022.
• Structure-based clustering and mutagenesis of bacterial tannases reveals active site-capping domains. PMC. 2024.
• Biochemical characterization of Aspergillus oryzae native tannase and the recombinant enzyme in Pichia pastoris. Biocatalysis and Agricultural Biotechnology. 2014.
• Anti-Nutritional Factors of Plant Protein Feeds for Ruminants and Methods for Their Elimination. PMC. 2025.
• Tannin in Ruminant Nutrition: Review. PMC. 2022.
• Influence of Addition of Tannase Enzyme to Reducing Tannins Effects in Lactating Goats Diets. Int J Dairy Sci. 2015.
• Study on the Effects of Tannase on the De-Astringency of Pomegranate Juice. PMC. 2025.
• Improving the Acid Resistance of Tannase TanBLp from Lactobacillus plantarum by Site-Specific Mutagenesis. PMC. 2022.
• Biotransformation of gallate esters by a pH-stable tannase of mangrove-derived yeast Debaryomyces hansenii. Front Mol Biosci. 2023.