Optimum Substrate Concentration Research Articles

Polyhydroxyalkanoates (PHAs) Production from Residual Glycerol by Wild Type Cupriavidus necator

PurposeThe main objective of the present study is to assess and improve fermentation conditions to produce polyhydroxyalkanoates (PHAs), such as the homopolymer poly(3-hydroxybutyrate) (PHB) and the copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), from renewable and inexpensive industrial waste by wild type Cupriavidus necator.MethodsUntreated residual glycerol, a byproduct generated by biodiesel industry, was used as the main carbon source by wild type C. necator. The bacterial adaptation stage, the glycerol concentration and other medium components were adjusted to enhance the PHB production. Fed batch fermentation with a pulse feeding strategy of propionic acid solution was employed for PHBV production.ResultsC. necator, previously adapted to glycerol utilization, was able to accumulate PHB up to 4.1 g/l under optimal substrate concentration conditions. The bacterium could also synthesize up to 3.4 g/l PHBV, with a mole fraction of 3-hydroxyvalerate (3HV) up to 12% by fed-batch fermentation with a pulsed propionic acid feed strategy.ConclusionThis is the first report on the use of residual glycerol as ideal feedstock for PHA production by wild type C. necator strain.Graphical Abstract

Efficient side-chain deacylation of polymyxin B1 in recombinant Streptomyces strains.

Polymyxins are antibacterial polypeptides used as "last resort"therapy option for multidrug-resistant Gram-negative bacteria. The expansion of polymyxin-resistant infections has inspired development of novel polymyxin derivatives, and deacylation is one of the critical steps in generating those antibiotics. Deacylase from Actinoplanes utahensis hydrolyze the acyl moieties of echinocandins, and also efficiently deacylates daptomycin, ramoplanin and other important antibiotics. Here, deacylase was studied considering its potential usefulness in deacylating polymyxin B1. All the six recombinant strains containing the deacylase gene catalyzed hydrolysis of polymyxin B1, yielding cyclic heptapeptides. The efficiency of recombinant S. albus (SAL701) was higher than that of the others, and deacylation was the most efficient at 40°C in 0.2M Tris buffer (pH 8.0) with 0.2M Mg2+. The optimal substrate concentration of SAL701 was increased from 2.0 to 6.0g/L. SAL701 was highly thermostable, showing no loss of activity at 50°C for 12h, and the mycelia could be recycled at least three times without loss of catalytic activity. SAL701 could not deacylate β-lactam substrate such as penicillin G and cephalosporin C. Deacylase catalyzes the amide bond 1 closest to the nucleus of polymyxin B1 rather than the other bond, suggesting that it has high catalytic site specificity. Homology modeling and the docking results implied that Thr190 in deacylase could facilitate hydrolysis with high regioselectivity. These results show that SAL701 is effective in increasing the cyclic heptapeptide moiety of polymyxin B1. These properties of the biocatalyst may enable its development in the industrial production of polymyxins antibiotics.

Enzymatic inhibitive determination of AB-Fubinaca and AB-Pinaca on screen printed carbon tetratiofulvalene electrodes modified with nanoparticles and carbon nanotubes

The rapid bio-sensing of the synthetic cannabinoids, AB-Fubinaca y AB-Pinaca, was developed and validated using six different electrode platforms. Screen-printed electrodes containing 3% tetrathiafulvalene (TTF) ink on the carbon electrode were modified with gold nanoparticles and carbon nanotubes. Then, acetylcholinesterase and glucuronyl transferase were immobilized on the surface of these carbon electrodes. A quantitative response was obtained by measuring the enzymatic inhibition caused by increasing concentrations of the target drugs. Acetylthiocholine iodide, serotonin, and β-D- phenolphthalein glucuronide were used as enzymatic substrates. Optimal pH, peak potential, and substrate concentration of each biosensor were studied. Analytical performance parameters and figures of merit, including LODs (< 1.5 × 10–4 mg/L), precision and reproducibility (< 10%), trueness (< 3%), demonstrate that the developed biosensors were able to interrogate low concentration of AB-Fubinaca y AB-Pinaca in a buffer environment. Michaelis Menten's apparent constants were estimated from inhibition calibration curves. They were lower than 2.0 × 10–3 M. Km inhibition values, and an interference study concluded which biosensor was the most selective for both drugs. AChE/AuNPs/SPCTTFEs with ATI, for AB-Fubinaca, pH = 7.00; ATI = 0.450 mM y Eap = +0.70 V; UDPGT/CNTNPs/SPCTTFEs with Serotonin substrate, AB-Pinaca, pH = 6.64; Cn Serotonin = 0.45 mM y Eap = +0.58 V. Performance parameters of the developed biosensors are acceptable as proof of concept, which opens an opportunity for their future application in forensic and chemical analysis.

BIOSENSOR FOR ALT MEASUREMENT

In this work, an amperometric biosensor to determine ALT, which will be part of a biosensor system for simultaneous measurement of AST and ALT and their ratios, was developed. A platinum disk electrode was used as the electrochemical transducer. To form a bioselective element, a mixture based on glutamate oxidase was applied to the surface of transducer. A universal method for measuring ALT activity using the developed biosensor was proposed and described. During the study, the optimal concentrations of ALT substrates (α-ketoglutarate - 50 μM, alanine - 4 mM) and coenzyme (50 mkM of PLP) were selected. The analytical characteristics of the developed biosensor were also investigated, namely, sensitivity, linear range, minimum limit of determination, selectivity, stability, etc. It was shown the fundamental possibility of using this biosensor to measure the content of ALT in real samples.

Optimizing Efficiency and Motility of a Polyvalent Molecular Motor.

Molecular motors play a vital role in the transport of material within the cell. A family of motors of growing interest are burnt bridge ratchets (BBRs). BBRs rectify spatial fluctuations into directed motion by creating and destroying motor-substrate bonds. It has been shown that the motility of a BBR can be optimized as a function of the system parameters. However, the amount of energy input required to generate such motion and the resulting efficiency has been less well characterized. Here, using a deterministic model, we calculate the efficiency of a particular type of BBR, namely a polyvalent hub interacting with a surface of substrate. We find that there is an optimal burn rate and substrate concentration that leads to optimal efficiency. Additionally, the substrate turnover rate has important implications on motor efficiency. We also consider the effects of force-dependent unbinding on the efficiency and find that under certain conditions the motor works more efficiently when bond breaking is included. Our results provide guidance for how to optimize the efficiency of BBRs.

Exergy analysis and optimization of bio-hydrogen and bio-methane cogeneration from corn stover based on genetic algorithm

In order to explore the influence of the technological parameters on the exergy efficiency of combined bio-hydrogen and bio-methane production process of corn stalk, an exergy equilibrium model was established based on exergy analysis. The method of genetic algorithm was applied to optimize the exergy efficiency of co-production process. The results showed that the exergy efficiency based on thermodynamics exergy at the optimal substrate concentration, initial pH value, and coupling time node was 23.43 %, 24.25 %, and 36.97 %, respectively. Exergy efficiency based on ecological exergy is 21.19 %, 21.92 %, and 31.46 %, respectively. The exergy efficiency based on thermodynamic exergy and ecological exergy behaves the same variation trend. When the optimal process parameters were substrate concentration 60 g/L, initial pH = 7, and coupling time node 12 h, the exergy efficiency was achieved up to 40.46 %, increased by 72.68 % compared to that without optimization.

Sugarcane bagasse as carbon source for the production of cellulase by Aspergillus niger

Background: In the presence of a suitable carbon source, filamentous fungi such as Aspergillus species are particularly important in enzyme production for industrial scale. The conversion of hemicelluloses from agro-waste biomass into valuable products has been considered strategic for the economic viability and bedrock of lignocellulose biorefineries. Methods: In the present study, we explore the potential of Aspergillus niger and Aspergillus flavus to utilized 3 agro-waste including sugarcane bagasse (SB), plantain pseudostem (PS), and corn cob (CC) as carbon sources for cellulase production, and determine the optimum yielding condition. Results: The results revealed that among the 3 agro-waste explored, SB was the most suitable carbon source utilized by A. niger and A. flavus for cellulase production. The maximum activity ranges of 205.03±3.25 and 302.13±2.56 IU/mL were obtained after 24 hr of fermentation with the SB. The optimum temperature, pH, and substrate concentrations were determined as 50∘C, 5, and 0.3% respectively. Conclusion: Collectively, the present study demonstrated that Aspergillus species when grown under sugarcane bagasse carbon source represent the best strategies for cheap production of cellulase. This information would be useful for the ideal formulation of media composition for maximum cellulase production by this organism.

Inhibitory effects of Moringa oleifera leaves extract on xanthine oxidase activity from bovine milk

Moringa oleifera is a tropical plant in the Moringaceae family that contains a lot of bioactive compounds. This study aimed to isolate and characterize the enzyme xanthine oxidase (XO), and conducted inhibitory tests on XO using methanol extracts of M. oleifera leaves. The xanthine oxidase enzyme isolated from bovine milk was characterized to determine the optimum pH, temperature, and substrate concentration. XO inhibition was evaluated by in vitro and in silico methods. The results of XO isolation and characterization of bovine milk showed the optimum conditions at pH 6.5, substrate concentration of 0.1 mM, and temperature 35 °C with an activity rate of 32.47 mU/mL; 21.55 mU/mL, and 21.94 mU/mL. Inhibition analysis results on methanol extract of M. oleifera leaves showed the highest activity decrease at the extract concentration of 160 ppm, with a relative inhibition value of 21.35%, while allopurinol as a positive control has a relative value inhibition of 61.21%. Relative value inhibition indicated the potential of M. oleifera leaves as a source of medicinal plants for gout sufferers. Additionally, a computational analysis was performed to observe the molecular interaction between the primary compounds of M. oleifera leaves, i.e., 5-O-acetyl-thio-octyl-β-L-rhamnofuranoside, quinic acid, and 2-dimethyl(trimethylsilylmethyl)silyloxymethyltetrahydrofuran, and XO using the molecular docking method. The finding implied that these compounds are bound to the catalytic sites of XO by hydrogen bonds and hydrophobic interactions, indicating the primary compounds of M. oleifera leaves could become XO inhibitors to treat gout disease.

Modelling of oligodextran production via an immobilized enzyme membrane reactor: Bioreaction-separation coupling mechanism

• The performance of immobilized EMR for oligodextran production is modeled. • The efficiency of an EMR is strongly dependent on the mass-transport limitations. • Kinetics of enzymatic reaction should match membrane filtration performance. • Increasing membrane selectivity and transmission benefits production efficiency. • Free EMR using higher enzyme concentration could compete with the immobilized EMR. Use of immobilized enzymatic membrane reactors (EMR) is an effective strategy to enhance oligodextran production efficiency. Nevertheless, the reaction-separation coupling mechanism has not been fully understood. In this study, we developed a model to disentangle the mechanism and interaction behind the reaction and separation phenomena in the immobilized EMR to eventually evaluate process performance for optimal oligodextran production. The simulation results show that in the immobilized EMR applying substrate feeding mode and high operating pressure enhances convective and diffusive flows through membrane, leading to a high transport rate of product. The optimal substrate concentration and enzyme loading amount need to match the selectivity and permeability of the membrane, in order to ensure rapid removal of the target oligodextrans. Therefore, the membranes with high permselectivity are required for obtaining desirable production efficiency and product quality. Although immobilized EMR has higher reaction rate at the beginning because of higher local enzyme concentration in the reaction zone, the EMR with free enzymes could outperform the immobilized EMR by using higher enzyme concentration due to its larger reaction area as the reaction continues. Our study provides deep insights into the reaction-separation coupling mechanism and EMR performance enhancement.

Development of an enhanced chain elongation process for caproic acid production from waste-derived lactic acid and butyric acid

Medium chain carboxylic acids (MCCA), such as caproic acid, are high-value chemicals with many industrial applications. The development of a biological mixed culture chain elongation (CE) process, using waste-derived lactic acid offers an opportunity to sustainably produce MCCA, such as caproic acid. However, the nature of the biological conversions in mixed communities is still poorly understood. In particular, inhibition of methanogens and MCCA competitors for the development of a specialised inoculum and optimisation of lactic acid conversion and selectivity toward caproic acid are required. Here, the impacts of physical and chemical treatments of the inoculum (anaerobic granular sludge) on the efficiency of CE were evaluated. Additionally, the effects of lactic acid/butyric acid concentrations and ratio (r LA/BA) on selectivity and concentration of caproic acid were investigated. Blended and acidified (pH 3) granular sludge yielded the highest caproic acid concentrations. Moreover, using pH 3 acidified and blended granular sludge, substrate concentrations of 250 mM (r LA/BA = 1.5:1) and 300 mM (r LA/BA = 1:1) were optimal for efficient caproic acid accumulation with a selectivity ≥90 and a mole of lactic to mole of butyric acid consumption (C r LA/BA) of 2:1. However, a similar outcome was achieved when using an enriched caproic acid producing culture with a lower substrate concentration of 200 mM (r LA/BA = 1:1). We report a lactic acid to butyric acid threshold concentration, below and above which the selectivity toward caproic acid is reduced. With these optimum substrate concentrations and ratios, the feasibility for efficient caproic acid synthesis using lactic acid as electron donor and butyric acid as electron acceptor was established. Caproic acid synthesis was completely inhibited when the substrate concentrations were increased to 400 mM (r LA/BA = 1:1). Finally, species affiliated with Ruminococcaceae were likely involved in the caproic acid synthesis. These findings have strong potential for process-design applications in continuous reactor systems, thus allowing for continuous, efficient and sustainable caproic acid production from biomass-derived lactic acid and butyric acid.

EFFECT OF SUBSTRATE CONCENTRATION AND FeCl2 ADDITION ON L-ASPARAGINASE ACTIVITIES OF BACTERIA SYMBIONTS BROWN ALGAE Sargassum sp. AND ITS POTENTIAL AS A NEW ANTI-DENGUE AGENTS

The disintegration of the amide link, causing L-Asparaginase catalyzes the hydrolysis process of L-Asparagine into ammonia and aspartic acid. The purposes of this study were to determine the optimal conditions for enzyme production and enzymatic activity, including their potential as a new anti-dengue of L-asparaginase from Klebsiella sp. The Nessler method used a UV-Visible spectrophotometer to determine the L-asparaginase activity by measuring ammonia levels produced by L-asparaginase catalysis. The ideal fermentation period was at the 48th hour, and the optimal substrate concentration was 10 g/L with an activity value of 49.572 U/mL, and the optimal FeCl2 concentration was 0.5 g/L with an activity value of 60.1183 U/mL, and protein content of 0.1878 mg/mL. The optimum conditions for L-asparaginase, which has an activity value of 61.1182 U/mL, were observed at pH 8 and 37 °C. The optimum cofactor concentration of FeCl2 was 0.5 mM, which resulted in an activity value of 106.5046 U/mL. Both the inhibition percentage and CC50 value were 80% and 167.15 μg/mL respectively, showing that the L-asparaginase has a high antidengue potential.

Development of Liquid Sugar HFS (High Fructose Syrup) from Lesser Yam Tubers Using Enzyme-Mix Inulinase and Amylase

Indonesia's sugar demand reaches 3.3 million tons/year, while domestic production is only 1.7 million tons or 51.5% of national demand, so imports are the choice. To reduce sugar imports, domestic sugar production needs to be continuously encouraged, in addition to looking for alternative sweeteners as sugar substitutes. Fructose syrup is an alternative to other sweeteners whose needs are increasing day by day. Apart from cassava, a local raw material that has been used as raw material for making liquid sugar is lesser yam tubers. The advantage of HFS liquid sugar produced from lesser yam tubers raw materials is that it only requires one process step, namely by using a mixture of enzymes inulinase and amylase (a mixture of gluco-amylase and alfa-amylase), where inulinase will hydrolyze inulin to fructose and amylase hydrolyzes starch become glucose. The research objectives were to find the optimum conditions for the production of liquid sugar HFS and to find the optimum concentration of liquid sugar from lesser yam tubers. The results of optimization of substrate and amylase enzyme showed that the optimum concentration of fresh lesser yam tubers substrate was 20%, alpha-amylase was 0.8% and gluco-amylase was 0.8%. The highest HFS liquid sugar was produced in the treatment of 20% inulinase enzyme concentration with a saccharification time of 48 hours, with a characteristic reducing sugar content of 22.958%; fructose content 3.96% and glucose content 23.04%.

Rational design of the C-terminal Loop region of leucine dehydrogenase and cascade biosynthesis L-2-aminobutyric acid

Leucine dehydrogenase (LDH) is the key rate-limiting enzyme in the production of L-2-aminobutyric acid (L-2-ABA). In this study, we modified the C-terminal Loop region of this enzyme to improve the specific enzyme activity and stability for efficient synthesis of L-2-ABA. Using molecular dynamics simulation of LDH, we analyzed the change of root mean square fluctuation (RMSF), rationally designed the Loop region with greatly fluctuated RMSF, and obtained a mutant EsLDHD2 with a specific enzyme activity 23.2% higher than that of the wild type. Since the rate of the threonine deaminase-catalyzed reaction converting L-threonine into 2-ketobutyrate was so fast, the multi-enzyme cascade catalysis system became unbalanced. Therefore, the LDH and the formate dehydrogenase were double copied in a new construct E. coli BL21/pACYCDuet-RM. Compared with E. coli BL21/pACYCDuet-RO, the molar conversion rate of L-2-ABA increased by 74.6%. The whole cell biotransformation conditions were optimized and the optimal pH, temperature and substrate concentration were 7.5, 35 °C and 80 g/L, respectively. Under these conditions, the molar conversion rate was higher than 99%. Finally, 80 g and 40 g L-threonine were consecutively fed into a 1 L reaction mixture under the optimal conversion conditions, producing 97.9 g L-2-ABA. Thus, this strategy provides a green and efficient synthesis of L-2-ABA, and has great industrial application potential.

Xylose Release from Sunflower Stalk by Coupling Autohydrolysis and Enzymatic Post-Hydrolysis

PurposeIn this study, to obtain xylose-based fermentation media from autohydrolysis liquors of sunflower stalk by using commercial xylanase formulation was aimed. Xylose is generally produced from xylan by diluted acid hydrolysis that causes the formation of some unwanted compounds during the process. As an alternative to dilute acid hydrolysis method, enzymatic hydrolysis of xylan can provide more specific hydrolysis under moderate conditions and does not cause the formation of undesirable compounds.MethodsXylose production was carried out with Trichoderma longibrachiatum xylanase on solubilized xylan form of sunflower stalk, which was hydrothermally pretreated for 1 h at 160 °C. The effects of substrate concentration and enzyme activity were investigated for the production of xylose. To obtain a high xylose yield and selectivity, the optimization study was conducted by the response surface methodology.ResultsThe optimum substrate concentration and enzyme activity were found as 60 mg ds/mL CAL and 234 U/mL, respectively. Under the optimum condition, xylose yield and selectivity were found to be 69.5% and 8.2 g/g, respectively.ConlusionThis study showed that xylose could be produce with a high yield without requiring a neutralization process and corrosive chemical reagent apart from water.Graphic Abstract

Dynamic Simulation of Bioethanol Production from Banana Rejected using Flocculating Yeast

A dynamic model is presented to simulate a fermentation process for bioethanol production from banana rejected using a batch system. The critical model feature is using an inhibition function to relate substrate concentration and specific growth rate. Kinetic parameters were calculated based on previous experimental data, and the optimal substrate concentration is investigated. The Andrews kinetic model was adapted to the concentration profiles, indicating that it could describe the existence of substrate and product inhibition. Different initial substrate concentrations were evaluated (90-400 g/L), and simulated results suggest 200 g/L of rejected banana as a starting point to reach a high and efficient bioethanol production since a maximal ethanol production is reached with a value of 150 g/L. However, when using a higher banana, rejected concentration inhibition occurs, and therefore bioethanol production decreases to reach levels lower than 100 g/L. Based on results found, kinetic models allow obtaining important observations on microbial metabolic processes and facilitating a good approximation for further large-scale stages.

Purification of the Acetyl CoACarboxylase-1 from Serum of Breast Cancer Women after Mastectomy

Acetyle CoA Carboxylase-1was purified from serum of premenop- ausal women with breast cancer (after Mastectomy or treatment ) by Gel Filtration using Sephadex G-100 and by Ion Exchange using DEAE-Cellulose A-50, also the molecular weight was estimated by the Electrophoresis on Acrylamide in the absence of denaturing elements . The result showed that a single band was obtained at 210 KD by Gel Filtering while Ion Exchange showed one band at 210 KD. The optimum temperature of purified Acetyle CoA Carboxylase-1 was 40 , optimal pH at 7.5 and the optimum substrate concentration at 1.8mM. Michaelis-Menten constant (km) was 0.3mM and Vmax was 23mM.min-1.

An Electrochemical Enzyme Biosensor for Ammonium Detection in Aquaculture Using Screen-Printed Electrode Modified by Gold Nanoparticle/Polymethylene Blue.

A SPEC/AuNPs/PMB modified electrode was prepared by electrodeposition and electro-polymerization. The electrochemical behavior of reduced nicotinamide adenine dinucleotide (NADH) on the surface of the modified electrode was studied by cyclic voltammetry. A certain amount of substrate and glutamate dehydrogenase (GLDH) were coated on the modified electrode to form a functional enzyme membrane. The ammonia nitrogen in the water sample could be calculated indirectly by measuring the consumption of NADH in the reaction. The results showed that the strength of electro-catalytic current signal was increased by two times; the catalytic oxidation potential was shifted to the left by 0.5 V, and the anti-interference ability of the sensor was enhanced. The optimum substrate concentration and enzyme loading were determined as 1.3 mM NADH, 28 mM α-Ketoglutarate and 2.0 U GLDH, respectively. The homemade ceramic heating plate controlled the working electrode to work at 37 °C. A pH compensation algorithm based on piecewise linear interpolation could reduce the measurement error to less than 3.29 μM. The biosensor exhibited good linearity in the range of 0~300 μM with a detection limit of 0.65 μM NH4+. Compared with standard Nessler’s method, the recoveries were 93.71~105.92%. The biosensor was found to be stable for at least 14 days when refrigerated and sealed at 4 °C.

Effect of substrate structure on medium chain fatty acids production and reactor microbiome

The medium chain fatty acids (MCFAs) produced from organic wastes can replace part fossil-fuel-based products to promote the sustainable development of economy and environment. However, the selection and collocation of feedstocks for MCFAs production are lack of reference basis. This study thereby aimed to investigate how the commonly used electron donor (ED) and substrate configuration affect MCFAs synthesis and then obtain the optimal substrate composition. It was found that the optimized ratios for ethanol/acetate, lactate/acetate, and ethanol/lactate/acetate were 3/1, 2/1, and 2/1/1, respectively, and the optimal substrate concentration was 400 mM C. Combining ethanol and lactate as co-EDs effectively concentrated substrate-carbon-flow (increased by 20–28% than sole ED) on MCFAs synthesis by promoting the elongation of butyrate and reutilization of by-products. As a result, the higher MCFAs yield of 646.22 mg COD/g COD and selectivity of 67.72% were obtained from co-EDs than those from sole ED. Moreover, the key functional bacteria enriched under different ED were also discrepant, which were Clostridium sensu stricto for ethanol, Corynebacterium for lactate, and Veillonella and Oscillibacter for ethanol-lactate, respectively. This study provided a basic but significant reference for the scale-up MCFAs production.

Optimum Design of N Continuous Stirred-Tank Bioreactors in Series for Fermentation Processes Based on Simultaneous Substrate and Product Inhibition

Optimization of the continuous fermentation process is important for increasing efficiency and decreasing cost, especially for complicated biochemical processes described by substrate and product inhibition. The optimum design (minimum volume) of CSTRs in series assuming substrate and product inhibition was determined in this study. The effect of operating parameters on the optimum design was investigated. The optimum substrate concentration in the feed to the first reactor was determined for N reactors in series. The nonlinear, constrained optimization problem was solved using the MATLAB function “fmincon”. It was found that the optimum design is more beneficial at high substrate conversion and at a medium level of feed substrate concentration. The best number of reactors is two to three for optimum arrangements and two for equal-size arrangements. The presence of biomass in the feed to the first reactor reduces the reactor volume, while the presence of product in the feed slightly increases the required total volume. The percentage reduction in the total volume using the optimum design compared to equal-volume design (R%) was determined as a function of substrate conversion and substrate concentration in the feed to the first reactor. The obtained R% values agree with experimental data available in the literature for ethanol fermentation.

OPTIMIZATION OF POMEGRANATE PEEL EXTRACTS FOR THE BIOCONVERSION OF THE ELLAGITANNINS TO ELLAGIC ACID USING ASPERGILLUS NIGER, RHIZOPUS ORYZAE AND MIXED CULTURE

Objective: The present study is aimed at optimization of concentration of substrate (pomegranate peel extract) for the production of Ellagic acid using Aspergillus niger and Rhizopus oryzae. Methods: Test organisms were isolated and identified using standard microbiological techniques. Collected pomegranate peels were dried, grained and used as the substrate for solid-state fermentation. Prepared spore suspension of the test organisms was inoculated and incubated at room temperature. At regular intervals of 24 h, samples were drawn and subjected to analysis of reducing sugar, soluble proteins, hydrolysable tannins and production of extracellular tannase using standard methods. Results: The results of the present investigation demonstrated the optimum substrate concentration for the active conversion of ellagitannins to ellagic was 15g of A. niger, 20g for R. oryzae and 15g for mixed culture. Conclusion: From the current work, it was concluded that solid-state bioprocessing of fruit substrates and fruit wastes using fungi has shown to enrich phenolic antioxidants and improve phytochemical consistency.