The present article deals with the studies on the effect of media ingredients, such as carbon, nitrogen, inorganic phosphates, surfactants, and metal salts, on phytase enzyme production by Aspergillus niger CFR 335 in submerged (SmF) and solid-state fermentations (SSF). The results obtained showed a 1.5-fold higher enzyme yield in the presence of sucrose in both SmF and SSF, while peptone was found to be a favorable nitrogen source for SmF. Sodium dihydrogen phosphate (NaH(2)PO(4)) favored 34% higher enzyme yield than the control, which was followed by 19% higher activity in potassium dihydrogen phosphate (KH(2)PO(4)) in SSF at 0.015% w/v. The addition of Tween-20 in SmF showed a maximum yield of 12.6 U/mL while, SDS suppressed the growth of the fungus. None of the surfactants favored the enzyme yield in SSF. Calcium chloride (CaCl(2)) was extensively efficient in stimulating more than 55% higher phytase production in SmF at 0.01% v/v. In SSF, none of the metal salts stimulated phytase production.

Phytase, that is extensively used as a feed additive is capable of hydrolyzing phytic acid, an antinutrient found in about 60-80 % of all the plant commodities. This enzyme improves the bioavailability of essential minerals such as Ca 2+ , Mg 2+ , P, Zn 2+ , Fe 3+ , that are bound to phytic acid. An extracellular phytase from a local fungal isolate, Aspergillus niger CFR 335 was purified to homogeneity through a threestep column chromatography using DEAE-Sephadex anion exchanger. An active fraction of the enzyme was obtained with NaCl gradient of 2.5 M in DEAE Sephadex column. The enzyme was purified up to 16 fold with a yield of 28.5 %. Substrate specificity studies revealed a highest specific activity of 32.6±3.1 U/mg for sodium phytate with the K m value of 0.08±0.1 mM. The molecular weight of the enzyme was 66 kDa with an optimum temperature of 30°C and pH 4.5. Up to 80 % of the activity was retained even after storing the enzyme for 6 months at 4°C.

No abstract

Introduction and Aim: Tannase an inducible extracellular microbial enzyme is extensively produced by different fermentation techniques and finds wide applications in food, pharmaceutical and textile industries. The present investigation focused on tannase production from Aspergillus niger through submerged (SmF) and solid-substrate fermentation (SSF) using different media. The enzyme was also induced using tamarind seeds.  Methods and Materials: Aspergillus niger was grown in various submerged media such as Tannase screening broth (TSB), Czapek Dox broth (CDB), Sabouraud’s Dextrose broth (SDB) and Potato Dextrose broth (PDB). Among solid substrates wheat bran, ground nut cake, coconut cake and tamarind seed powder used individually and in mixed form. Results: In SmF, the highest tannase activity of 713.6 U/ml was found in TSB, followed by CDB (590.6 U/ml), SDB (465.6 U/ml) and PDB (424.8 U/ml).  In all media highest activity was on 4th day while in SDB on 6th day of incubation. Tannase production was also carried out in CDB supplemented with 2% processed tamarind seeds to test for its induction, where the highest (936 U/ml) activity was in raw seeds than in processed seeds. SSF in mixed substrates showed highest activity of 1708.6 U/gds followed by 1278.0, 986.5, 826.3 and 723.6 U/gds in tamarind seeds, wheat bran, ground nut cake and coconut cake, respectively. Conclusion: Tannase enzyme is found to be induced by raw tamarind seed supplemented submerged medium than with processed seeds. In SSF with tamarind seed showed the highest tannase activity indicating that the tannic acid present in raw seeds serve to induce Aspergillus niger for increased production of tannase enzyme.

Introduction and Aim: Oilseeds are an important source of nutrition in developing countries, which are either consumed directly or as snacks. However, the presence of anti-nutritional factors limits their use. This study evaluated the potential application of probiotic Lactobacillus plantarum in reducing the anti-nutritional content in peanut, mustard and sesame.   Materials and Methods: Peanuts, sesame and mustard seeds were coarsely ground, defatted by Soxhlet extraction method using hexane and fermented by submerged fermentation method using Lactobacillus plantarum. After fermentation for 72hrs, the contents were centrifuged and the pellets in addition to defatted raw sample were analyzed for anti-nutrients like polyphenols, oxalates, trypsin inhibitors and lectins using standard protocols.   Results: Polyphenol content was reduced by 26.40, 46.70 and 41.50%, while oxalate content exhibited 61.50, 32.70 and 37.70% reduction in peanut, mustard and sesame respectively. Trypsin inhibitor activity was reduced by 80.00, 12.13 and 77.78%, while lectin exhibited 87.50, 62.50 and 64.87% reduction in peanut, mustard and sesame respectively.   Conclusion: Peanut showed maximum reduction in oxalates, trypsin inhibitors and lectins followed by sesame and mustard. However, highest polyphenol reduction was exhibited in sesame. Hence, from the present investigation, it is found that fermentation may be a promising tool in reducing anti-nutritional factors from oil seeds.