Tannase

Guava juice is known to be rich in antioxidant activity due a high level of vitamins A and C. However, tannins present in the guava juice form tannin–protein complexes that affect the utilization of vitamins and minerals and inhibit digestive enzymes. Beside this, bitterness and cloudiness are the other major problems of juice industries. The present study aimed to utilize a low-cost substrate (tea residue) for the production of tannase and its application in detannification of guava juice. Solid-state fermentation (SSF) was evaluated to produce tannase from Aspergillus niger. Maximum tannase (1.86 U=g dry substrate) production was observed at 30 °C after 96 hr of the incubation period. The optimum pH of the moistening agent was found to be 5.0. Partially purified enzyme using ammonium sulfate precipitation was subjected to guava
juice treatment at a level of 0.5, 1.0, and 2.0% for 30 and 60 min. Decrease in tannic acid content of guava juice was found to be 17.60, 29.04, and 44.38% after 30 min and 40.59, 53.69, and 59.23% after 60 min, respectively.

Present work deals with optimize the cultural condition and medium composition for enhancing the tannase production by Rhodoforula glutinis DB2 in submerged fermentation. A tannase-producing read yeast strain R. glutinis DB2 was isolated from hydrolysable tannin solution (extracted from Rhizophora apiculate bark) that kept for a year at room temperature (30±2 0C), This yeast strain showed ability to produced extracellular tannase significantly under submerged fermentation using tannic acid as an inducer. The rapid degradation of tannic acid and production of extracellular tannase was observed in the submerged fermentation medium. R. glutinis DB2 produced maximum extracellular tannase activity at the optimum bioprocess condition with 0.75 U/ mL and the yeast growth of 8.7 g/L. These results indicate that an increment about 83% of tannase production was obtained compared to before optimizaation of cultural condition (0.41 U/ mL).

Aspergillus niger has been tested in a discontinuous process for the pretreatment of fresh green Processing Waste waters (TOPW). The influence of seven factors like incubation time, initial pH, dilution, glucose, agitation, (NH 4 ) 2 SO 4 and inoculum size on decolorization was screened by employing a fractional factorial design 2 7-4 . Through factorial plots and analysis of variance, it was found that only glucose and agitation affected the decolorization. Further studies were carried out to adjust the level of determinant factors. Results showed that color removal (62%) was optimum at 150 rpm and 3 g/l glucose. HPLC and FTIR analysis of the treated TOPW suggested that the decolorization occurs through biosorption and biodegradation. Tannase and lignin peroxidase were detected in the cultures. However, only tannase is responsible for the color removal of the TOPW because lignin peroxidase is produced at a low level. Characteristics Fresh TOPW pH 12.3 ± 0.4 TSS (g/l) 1.09 ± 0.13 CODs (g/l) 17.2 ± 3.2 Color (OD 390nm) 4.86 ± 0.33 Reducing sugars (g/l) 3.31 ± 0.18 TKN (g/l) 0.69 ± 0.05 TP (mg gallic acid/l) 506.9 ± 38

Tannase is an industrially important enzyme produced by a large number of microorganisms. This study analyzed the production of tannase by Aspergillus sp. GM4 under solid-state fermentation (SSF) using different vegetable leaves (mango, jamun and coffee) and agricultural residues (coffee husks, rice husks and wheat bran). Among the substrates used jamun leaves yielded high tannase production. The Plackett-Burman design was conducted to evaluate the effects of 12 independent variables on the production of tannase under SSF using jamun leaves as substrate. Among these variables, incubation time, potassium nitrate and tannic acid had significant effects on enzyme production. A lower incubation time was fixed and supplementation with potassium nitrate and tannic acid were optimized using the Central Composite Design. The best conditions for tannase production were: incubation time of 2 days; tannic acid at 1.53% (w w-1) and potassium nitrate at 2.71% (w w-1). After the optimization process, tannase production increased 4.65-fold, which showed that the statistical experimental design offers a practicable approach to the implementation of optimization of tannase production.

Summary The antioxidant activities of native- and tannase-treated green tea extracts along with their major polyphenol components were investigated. The polyphenolic content and composition of the tea before and after tannase treatment were determined by liquid chromatography coupled with mass spectrometry (LC-MS). Approximately 99% of the (−)-epigallocatechin gallate (EGCG) and (−)-epicatechin gallate (ECG) in green tea extract were converted by tannase to (−)-epigallocatechin (EGC) and (−)-epicatechin (EC), respectively, after 30 min. Biotransformed green tea exhibited a significantly higher DPPH˙ radical scavenging activities than native green tea (EC50 value of 0.024 ± 0.001 and 0.044 ± 0.001 mg mL−1, respectively). Kinetic parameters such as scavenging rate and stoichiometry were calculated. The rate of DPPH˙ radical scavenging activities for tannase-treated green tea extract was shown to be higher than native green tea extract.

La tanino acil hidrolasa (E.C.3.1.1.20) conocida comúnmente como tanasa, es una enzima capaz de catalizar la hidrolisis de los enlaces tipo éster de los taninos hidrolizables, tal como lo es el ácido tánico (1-3), que al ser hidrolizado por la enzima libera ácido gálico y glucosa. La tanasa puede ser producida por hongos del genero Aspergillus, Penicillum, Trichoderma y Fusarium, también por bacterias y levaduras. Dicha enzima tiene un amplio uso comercial, como agente clarificante de bebidas, en la fabricación de té instantáneo y en las industrias químicas y farmacéuticas, para la producción de ácido gálico, utilizando diferentes fuentes de plantas ricos en taninos (4-5). Sin embargo, actualmente su uso se encuentra limitada debido a su gran costo de producción.

Tannin acyl hydrolase is an industrially important enzyme that is mainly used in the food and pharmaceutical industry. Tannase production was investigated using Aspergillus niger isolated from bark of tannin rich Acacia nilotica. Factors influencing tannase production and activity included the effects of incubation period, incubation temperature, pH, carbon and nitrogen sources on A. niger. The optimum culture conditions determined were 1% (w/v) tannic acid as inducer, 7 days (168 hrs) incubation period, 30°C incubation temperature, pH 5.0, 1% (w/v) tannic acid as carbon source and 1% (w/v) sodium nitrate as nitrogen source for maximum tannase activity. The enzyme production was found to be associated with the growth of the fungal culture. Thus, the present study proved that the screened fungal strain Aspergillus niger used is highly useful for industrial production of tannase.

Aspergillus niger FBT1, a local extracellular strain for tannase production, was isolated from soil collected from Matang Mangrove Forest Reserve in Perak, Malaysia. This fungus strain was cultivated in an Erlenmeyer flask under a submerged fermentation system. Medium compositions play a very important role in enhancing enzyme production during fermentation. The production of tannase by A. niger FBT1 increased significantly (95%) when the medium compositions and various process parameters were optimized. Incubation for 72 hours (30 0C, pH 7) in medium complemented with sodium nitrate was found optimal. Additional supplementation with tannic acid (2% w/v) as the sole carbon source strongly increased the yield of the enzyme.

Guava juice is known to be rich in antioxidant activity due a high level of vitamins A and C. However, tannins present in the guava juice form tannin-protein complexes that affect the utilization of vitamins and minerals and inhibit digestive enzymes. Beside this, bitterness and cloudiness are the other major problems of juice industries. The present study aimed to utilize a low-cost substrate (tea residue) for the production of tannase and its application in detannification of guava juice. Solid-state fermentation (SSF) was evaluated to produce tannase from Aspergillus niger. Maximum tannase (1.86 U/g dry substrate) production was observed at 30°C after 96 hr of the incubation period. The optimum pH of the moistening agent was found to be 5.0. Partially purified enzyme using ammonium sulfate precipitation was subjected to guava juice treatment at a level of 0.5, 1.0, and 2.0% for 30 and 60 min. Decrease in tannic acid content of guava juice was found to be 17.60, 29.04, and 44.38% after 30 min and 40.59, 53.69, and 59.23% after 60 min, respectively.

Even though tannase has wide applications it is still considered as novel and one of
the costly enzymes. Recognizing the need of the hour it becomes important to
isolate and develop potent tannase producing strains that can be used for
economical and feasible tannase production. The aims of the present study are to
isolate, identify and screen the tannase producing microorganisms from various tea
waste dump sites, agro-residue waste sites and tannery effluents. These soil
samples and tannery effluents are rich in tannins and its derivatives. Seven fungal
isolates and thirteen bacterial isolates were obtained as tannase producers from
tannic acid agar plates. Their morphology, microscopic and biochemical
characteristics were studied. Zone of hydrolysis formed by them revealed their
tannin degrading ability. Enzyme activity of these cultures producing tannase was
studied under static and shaking condition. The enzyme activity of fungal cultures
FT 2 (6.35 U/mL) and FT 6 (6.09 U/mL) and bacterial cultures BT 6 (20.9 U/mL)
and BT 11 (20.9 U/mL) were maximum in static condition while fungal isolates FT
1 (5.58 U/mL) and FT 4 (7.5 U/mL) and bacterial isolates BT 3 (25.73 U/mL) and
BT 8 (25.71 U/mL) showed optimum activity in shaking condition. However, FT
5(6.20 U/mL and 4.24 U/mL) and BT 7 (19.55 U/mL and 25.35 U/mL) showed
consistent activity under both the conditions. Thus the present study helps in
screening the potent tannase producers from waste dump sites and tannery
effluents.