Peptone Concentration Research Articles

Statistical based media optimization and production of naringinase using Aspergillus brasiliensis 1344

Statistics based optimization, Plackett–Burman design (PBD) and response surface methodology (RSM) were employed to screen and optimize the media components for the production of naringinase from Aspergillus brasiliensis MTCC 1344, using solid state fermentation. Cassava waste (CW) was used as both the solid support and carbon source for the growth of A. brasiliensis. Based on the positive influence of the Pareto chart obtained from PBD on naringinase activity, three media components – maltose, peptone and calcium chloride were screened. Box–Behnken design (BBD) was employed using these three factors at three levels, for further optimization, and the second order polynomial equation was derived, based on the experimental data. Derringer's desired function methodology showed that the concentrations of maltose (7.74g/L), peptone (4.19g/L) and calcium chloride (7.63mM) were the optimal levels for maximal naringinase activity (889.91U/mg) which were validated through experiments.

Biohydrogen production using anaerobic mixed bacteria: Process parameters optimization studies

Process parameters optimization using response surface methodology (RSM) and artificial neural network (ANN) coupled with Genetic Algorithm (GA) were carried out to analyze the influence of process parameters on maximum hydrogen production and H2 yield using sucrose as a sole carbon source. Alkali pretreated mixed culture obtained from the food waste was used for fermentative hydrogen production. Box-Behnken design was applied to examine the interactive effect of the significant variables (sucrose concentration, initial pH, inoculum size, and peptone concentration). Characterization of culture indicated that the culture was gram-negative facultative anaerobe. Maximum experimental hydrogen yield of 2.36 mol H2/mol sucrose was achieved at the optimal points predicted by the RSM. Modified Gompertz model and logistic model adequately fitted well and described the fermentative hydrogen production and bacterial growth, respectively. Process modeling abilities of ANN and RSM were compared on the basis of parameters such as estimated values of root mean square error (RMSE), multiple correlation coefficients (R2), and standard error of prediction (SEP). GA couple with ANN was used to find the global optimum point and the maximum H2 yield of 2.39 mol H2/mol sucrose was found at sucrose concentration 15.5 g/l, pH 8, inoculum size (% v/v) 8.4, and peptone concentration 4.9 g/l. The estimated values of RMSE, R2, and SEP for ANN model and RSM model confirm that fitness and prediction accuracy of ANN model was higher when compared to RSM model. From this study, we confirmed that genetic algorithm coupled with ANN technique can be a powerful tool to obtain global optimization in biochemical systems.

Production of Bioactive Compounds with Antitumor Activity Against Sarcoma 180 by Pleurotus sajor-caju

This work studied the influence of culture medium composition and pH on exopolysaccharide (EPS) production by Pleurotus sajor-caju and validates the antitumor activity of the produced EPSs and of the mycelial biomass (intracellular polysaccharides [IPSs]) against Sarcoma 180 (S180) cells. The effect of the initial concentrations of (NH₄)₂SO₄, yeast extract and soy peptone on EPS production by P. sajor-caju was studied in shake flasks. A bioreactor was used to evaluate the pH values and the initial CaCO₃ and glucose concentrations. Extracts of EPSs (PE1) and IPSs obtained through two different separation processes (PM1 and PM2) were tested on mice inoculated with S180 cells. A medium containing 2.5, 1.0, and 1.0 g/L of (NH₄)₂SO₄, yeast extract and soy peptone, respectively, provided the highest EPS concentration (0.6 g/L). The use of pH 4.0, 1.0 g/L CaCO₃ and 20 g/L initial glucose concentration enhanced EPS productivity (3.84 g/L per hour). The PE1 extract promoted the highest reduction of S180 growth (86%), followed by the PM2 extract (80%); growth reduction was dose-independent for both substances. This work provides information about culture medium and conditions that enhanced the production of extracellular polysaccharides by P. sajor-caju. The results can contribute to the search for new bioactive products bringing novel aspects to the medical and pharmaceutical areas.

Biodegradation of benzyl benzoate by Pseudomonas desmolyticum NCIM 2112

Commercial grade insecticides are supplemented with the chemical additives to enhance the insecticidal activity before the action of main insecticide commence. Benzyl benzoate is one of such additive used in the formulation of many insecticides. Due to deposition of such additive the soil and plant health get deteriorated. The present research work describes the biodegradation of benzyl benzoate by Pseudomonas desmolyticum NCIM 2112. The biodegradation was influenced by factors such as pH, temperature and other carbon and nitrogen sources. The optimum pH and temperature for biodegradation was found to be 7.0 and 30 °C respectively. It was more effective at 0.5 % glucose and lactose concentration and at 0.05 % NaNO₃ and peptone concentration. Pseudomonas desmolyticum NCIM 2112 degrades benzyl benzoate into compounds like benzaldehyde and benzoic acid which are nontoxic in nature. Phytotoxicity study shows no germination inhibition in presence of degraded metabolites.

Wood Degradation and Optimized Laccase Production by Resupinate White-Rot Fungi in Northern Thailand

One hundred and thirty samples of resupinate white-rot fungi were collected from natural sites in Northern Thailand during the dry season (October-December) as a bioresource for lignin-degrading enzymes (laccase (Lac), lignin peroxidase (LiP), and manganese peroxidase (MnP)). All 130 isolated fungal strains grew well in potato dextrose broth and produced lignin-degrading enzymes at different levels after 7 days of incubation. The selected resupinate fungi, RCK783S, produced maximum Lac at 4,218 U/L, whereas MnP and LiP activities were detected at relatively low levels in all selected fungal strains. The RCK783S was further identified as a new record of Fibrodontia sp. in Thailand. Response surface methodology (RSM) was applied to evaluate the effect of medium composition, i.e., peptone, glycerol, L-asparagine, and CuSO4, on Lac production by Fibrodontia sp. RCK783S. The experiments showed optimum concentrations of peptone, glycerol, L-asparagine, and CuSO4 at 0.625, 15.00, 2.188, and 0.003 g/L, respectively, to produce the highest Lac concentration of 6,086.01 U/L, a 1.44-fold increase from that in the original medium. In addition, the degradation of Eucalyptus camaldulensis was investigated during the solid-state cultivation of Fibrodontia sp. RCK783S. The results showed that lignin was degraded, with lignin loss being 18% after 30 days, coinciding with the highest released Lac activity.

STATISTICAL OPTIMIZATION OF PIGMENT PRODUCTION BY Monascus sanguineus UNDER STRESS CONDITION

Natural pigments are produced by the Monascus sp., which are used for coloring food substances. The intent of this study was to optimize the pigment yield and biomass produced from the unexplored Monascus sanguineus in submerged culture under stress conditions. For inducing thermal stress, the spores were incubated at various temperatures at higher ranges. For inducing osmotic stress, varied concentrations of NaCl, glycerol, and peptone were used. The medium components were optimized by response surface methodology (RSM). The combined effects of the four medium constituents mentioned were studied using a 24 full factorial central composite design (CCD). The relationships between the predicted values and actual values, independent variable, and the response were calculated according to a second-order quadratic model. It was deduced that the variable with the leading effect was the linear effect of glycerol concentration. Furthermore, the quadratic effects of peptone and the interactive effects of temperature and glycerol were more noteworthy than other factors. The optimum values for the test variables in coded factors were found to be spores treated with 70°C for temperature, 0.25 M for glycerol, 0.51% (w/v) for peptone, and 1.25% (w/v) for NaCl, corresponding to a maximum red pigment yield of 55.67 color value units (CVU)/mL. With optimized conditions, the pigment yield was almost three times the yield observed with the control.

Biotransformation of progesterone to hydroxysteroid derivatives by whole cells of Mucor racemosus

Aims: The possibility of using Mucor racemosus cells in the biotransformation of progesterone to industrially important hydroxysteroid derivatives in one-step biotransformation process was investigated in this study Methodology and results: The fungal strain was inoculated into the transformation medium which supplemented with PR as a substrate (5-50 mg). The transformation products were separated and characterized on the bases of their GC/MS analysis as 11α-hydroxyprogesterone (11α-HP) as main product (I); 4-pregnen-18-al-11β,21-diol-3,20-dione (Aldosterone) (II) and 20-hydroxy-pregnan-18-oic acid (III) as minor products. The organism was tested for PR bioconversion at different transformation periods (6-96 h), as well as optimization of the basal medium through the addition of different concentrations of yeast extract and peptone (0.5 to 4 g/L) at various pH values (4-9). The optimal biotransformation conditions for maximum production of these PR derivatives were observed using 0.2 g/L of PR, 3 g/L of yeast extract and 3 g/L peptone after 48 h at pH value 5.5. Under these optimal conditions, cells total bioconversion efficiency reached about 96% of the original added PR. Conclusion, significance and impact of study: Under these optimum conditions, M. racemosus has the ability to biotransform PR to 11α-HP (I), Aldosterone (II) and 20-hydroxy- pregnan-18-oic acid (III) with total bioconversion efficiency of 96 ± 1.77%. These results may be of industrial importance because compounds II and III had not been previously recorded as biotransformation products of PR.

Production of a Recombinant Laccase from Pichia pastoris and Biodegradation of Chlorpyrifos in a Laccase/Vanillin System

The recombinant strain P. pastoris GS115-lccC was used to produce laccase with high activity. Factors influencing laccase expression, such as pH, methanol concentration, copper concentration, peptone concentration, shaker rotate speed, and medium volume were investigated. Under the optimal conditions, laccase activity reached 12,344 U/L on day 15. The recombinant enzyme was purified by precipitating and dialyzing to electrophoretic homogeneity, and was estimated to have a molecular mass of about 58 kDa. When guaiacol was the substrate, the laccase showed the highest activity at pH 5.0 and was stable when the pH was 4.5~6.0. The optimal temperature for the laccase to oxidize guaiacol was 60°C, but it was not stable at high temperature. The enzyme could remain stable at 30°C for 5 days. The recombinant laccase was used to degrade chlorpyrifos in several laccase/mediator systems. Among three synthetic mediators (ABTS, HBT, VA) and three natural mediators (vanillin, 2,6-DMP, and guaiacol), vanillin showed the most enhancement on degradation of chlorpyrifos. Both laccase and vanillin were responsible for the degradation of chlorpyrifos. A higher dosage of vanillin may promote a higher level of degradation of chlorpyrifos, and the 2-step addition of vanillin led to 98% chlorpyrifos degradation. The degradation of chlorpyrifos was faster in the L/V system (kobs = 0.151) than that in the buffer solution (kobs = 0.028).

Periplasmic expression optimization of VEGFR2 D3 adopting response surface methodology: Antiangiogenic activity study

Vascular endothelial growth factor (VEGF) is one of the most significant mediators of angiogenesis, which interacts with a specific membrane receptor: VEGF receptor 2 (VEGFR2). Studies elsewhere have shown that, a VEGF-blocker can regulate several vital processes of tumor promotion. However, there is no literature evidence of investigation on antiangiogenic ability of single domain 3 of VEGFR-2 (VEGFR2 D3), as the key domain in signal transduction of VEGF. In this article, we aimed at developing an efficient method for producing soluble form of this receptor as therapeutic applications. The optimization of the production of soluble VEGFR2 D3 in Escherichia coli was firstly done by testing the periplasmic expression in different expression systems using three osmotic shock methods. To enhance the yield, vital factors were selected from nine factors by Plackett–Burman design and the level of each viral factor was optimized via a response surface methodology based central composite design. After purification and identification of the protein, the bioactivity assays: quantitative ELISA, VEGF-induced proliferation and in vivo chick chorioallantoic membrane assay were employed in our study. The outcome showed that, E. coli Rosetta-gami (DE3)/pET22b-VEGFR2 D3 was the most effective expression system. Furthermore, the inducing time, peptone and glycerol concentration affected the periplasmic expression of VEGFR2 D3 significantly. The corresponding level was also optimized. The bioactivity assay studies showed VEGFR2 D3 could suppress both VEGF stimulated cell proliferation in vitro and neovascularization in vivo. We have therefore provided a novel antiangiogenic drug candidate relating to VEGF-VEGFR2 pathway.

Optimization of biohydrogen production by Enterobacter species using artificial neural network and response surface methodology

Optimization studies on fermentative hydrogen production were investigated using a facultative bacteria namely, Enterobacter species (MTCC 7104). The present study emphasizes the application of mathematical tools such as response surface methodology (RSM) and artificial neural network (ANN) to predict the maximum yield of hydrogen from the optimized carbon and nitrogen source. The key components such as glucose, initial pH, xylose, tryptone, yeast extract, sucrose, and peptone were screened using the Plackett-Burman design. Furthermore, rotatable central composite design and analysis of variance were adopted to investigate the interactive effect of the significant variables (xylose concentration, initial pH, and peptone concentration). Maximum experimental hydrogen yield of 1.94 mol H2/mol xylose was achieved at the optimal points predicted by the RSM. Modeling ability of ANN and RSM has also been evaluated on predicting the maximum hydrogen yield with the estimated values of root mean square error (RMSE), multiple correlation coefficients (R2), and standard error of prediction (SEP). The estimated values of RMSE, R2, and SEP for ANN model and RSM model confirm that fitness and prediction accuracy of ANN model were higher when compared to RSM model. Energy conversion efficiency and energy recovery analysis were performed for hydrogen production process using xylose as the source material.

Polyunsaturated fatty acid production by marine bacteria

Polyunsaturated fatty acids are important in maintaining human health. Limitations associated with current sources of ω-3 fatty acids and ω-6 fatty acids, from animal and plant sources, have led to increased interest in microbial production. Marine bacteria may provide a suitable alternative, although the isolation of production strains and the identification of operating conditions must be addressed before manufacturing processes become economically viable. Marine isolate 560 was identified as an eicosapentaenoic acid (EPA) producer via GC/MS. The isolate was initially identified as Vibrio cyclitrophicus by 16S rRNA sequencing. Statistically based experimental designs were applied to the optimisation of medium components and environmental factors for the production of EPA. A Plackett-Burman design was used to screen for the effect of temperature, pH, and media components. Subsequently, the concentrations of NaCl, yeast extract, and peptone, identified as significant factors, were optimised using a central composite design. The predicted optimal combination of media components for maximum EPA production (4.8 mg/g dry weight) was determined as 7.9 g/l peptone, 16.2 g/l NaCl, and 6.2 g/l yeast extract. On transfer of this process to bioreactor cultivation, where a range of pH and DO values were tested, the maximum amount of EPA produced increased to 7.5 mg/g dry weight and 10 % of the total fatty acid.

Ozone Degradation of Cyclophosphamide – Effect of Alkalinity and Key Effluent Organic Matter Constituents

The influence of three effluent organic matter (EfOM) model compounds (alginic acid, peptone and natural organic matter-NOM) and alkalinity on the ozonation of cyclophosphamide (CPD) was investigated. The rate of ozone decay increased with increasing model compounds concentration in the order of peptone > NOM > alginic acid. Increasing alkalinity inhibited ozone decay at all concentrations of alginic acid and at low concentrations of NOM and peptone (DOC < 3 mg/L), while at high NOM and peptone concentrations the effect of alkalinity on ozone decay was minor. Presumably, ozone decay was mainly controlled by direct reaction with these two model compounds, resulting in •OH (hydroxyl radical) formation yield of 29% and 19%, for peptone and NOM respectively. In the presence of alginic acid •OH formation through a radical chain reaction resulted in a yield of 30%. Cyclophosphamide (CPD) removal decreased with increasing alkalinity and model compounds concentration (most pronounced for peptone and less pronounced for alginic acid); most likely due to increase in the scavenging effect on •OH.

From crude glycerol to carotenoids by using a Rhodotorula glutinis mutant

In this work eighteen red yeasts were screened for carotenoids production on glycerol containing medium. Strain C2.5t1 of Rhodotorula glutinis, that showed the highest productivity, was UV mutagenized. Mutant 400A15, that exhibited a 280% increase in β-carotene production in respect to the parental strain, was selected. A central composite design was applied to 400A15 to optimize carotenoids and biomass productions. Regression analyses of the quadratic polynomial equations obtained (R(2)=0.87 and 0.94, for carotenoids and biomass, respectively) suggest that the models are reliable and significant (P<0.0001) in the prediction of carotenoids and biomass productions on the basis of the concentrations of crude glycerol, yeast extract and peptone. Accordingly, total carotenoids production achieved (14.07±1.45mgl(-1)) under optimized growth conditions was not statistically different from the maximal predicted (14.64±1.57mgl(-1)) (P<0.05), and it was about 100% higher than that obtained under un-optimized conditions. Therefore mutant 400A15 may represent a biocatalyst of choice for the bioconversion of crude glycerol into value-added metabolites, and a tool for the valorization of this by-product of the biodiesel industry.

Medium factors affecting extracellular protease activity by &amp;lt;i&amp;gt;Bacillus&amp;lt;/i&amp;gt; sp. HTS 102—A novel wild strain isolated from Portuguese merino wool

The synthesis of an extracellular protease by Bacillus sp. HTS102—a wild strain recently isolated from the wool of Portuguese Merino ewes, was optimized. This protease is thermostable and particularly resistant to harsh environmental conditions—and appears to bear a unique ability to hydrolyze keratin-rich solid materials. Following a preliminary screening for the most relevant medium factors involved in processing, a fractional factorial design (2VI6-1) was applied to ascertain the effects of six relevant parameters—viz. yeast extract concentration, peptone level, inoculum size, stirring rate, temperature and pH. The concentrations of yeast extract and peptone, as well as the incubation temperature and pH were found to play significant roles; and the 2-factor interaction between yeast extract level and pH was also significant. A 2.2-fold increase in the overall level of protease synthesis was eventually attained, with the improved medium relative to the basal medium—which is noteworthy when compared with competing proteases and previous optimization efforts.

Production and Evaluation of Biocolour (carotenoids) fromRhodotorulausing Apple Pomace: Effect of Composition of different Nitrogen Sources and Methods of Cell Disruption

Efforts were made to optimize various parameters for production of carotenoids from Rhodotorula isolated from spoiled sauerkraut using apple pomace based media. Among various media tried (with varying concentration of peptone, yeast extract and dextrose), a medium having 40 g/L of apple pomace gave the highest production of carotenoids. Ferrous ammonium sulphate at a concentration of 0.5% and 0.2% showed higher carotenoids production when used with apple pomace (10, 20, 30 and 40 g/L) and 60 g/L, respectively. Among all the combinations tried, the highest carotenoid production (46.42 mg/100g) was observed in the medium supplemented with 0.5% ferrous ammonium sulphate and 40 g/L apple pomace. Whereas, urea at concentrations of 0.1% and 0.4% showed higher carotenoids production when used with apple pomace (10, 20, 40 and 60 g/L) and 30 g/L, respectively. Among all the combinations of urea and apple pomace, the highest carotenoid production (31.37 mg/100g) took place in the medium supplemented with 0.1% urea and 20 g/L apple pomace. Out of ferrous ammonium sulphate and urea, the former proved to be better than later. Use of pestle and mortar with glass beads proved an efficient method for the disruption of Rhodotorula cells to extract pigment. Out of various solvents used (acetone, petroleum ether, hexane and ethanol), petroleum ether was the best for the extraction of pigment. The pigment, a carotenoid (with two components) extracted from Rhodotorula showed 5% antioxidant activity.

Optimization of flask culture medium and conditions for hyaluronic acid production by a streptococcus equisimilis mutant nc2168

A mutant designated NC2168, which was selected from wild-type Streptococcus equisimilis CVCC55116by ultraviolet ray combined with60Co-γ ray treatment and does not produce streptolysin, was employed to produce hyaluronic acid (HA). In order to increase the output of HA in a flask, the culture medium and conditions for NC2168 were optimized in this study. The influence of culture medium ingredients including carbon sources, nitrogen sources and metal ions on HA production was evaluated using factional factorial design. The mathematical model, which represented the effect of each medium component and their interaction on the yield of HA, was established by the quadratic rotary combination design and response surface method. The model estimated that, a maximal yield of HA could be obtained when the concentrations of yeast extract, peptone, glucose, and MgSO4 were set at 3 g/100 mL, 2 g/100 mL, 0.5 g/100 mL and 0.15 g/100 mL, respectively. Compared with the values obtained by other runs in the experimental design, the optimized medium resulted in a remarkable increase in the output of HA and the maximum of the predicted HA production was 174.76 mg/L. The model developed was accurate and reliable for predicting the production of HA by NC2168.Cultivation conditions were optimized by an orthogonal experimental design and the optimal conditions were as follows: temperature 33ºC, pH 7.8, agitation speed 200 rpm, medium volume 20 mL.

High-throughput screening strategy used for enhanced production of pigment by Monascus purpureus D39-4

Most of the fermentation experiment designs were limited by the low-throughput of shake flask, especially for the medium optimization. A simple high-throughput screening system was developed for the determination of pigment in Monascus purpureus fermentation samples. This downscaled system was designed to optimize medium composition combined with statistical methods. The total 29 experiments designed by the Box-Behnken were used to study the 4 most important operating variables on pigment production. The analysis revealed that the optimum concentrations of glucose, peptone, NaNO3, and KH2PO4 were 51.42, 4.91, 1.00, and 1.00 g/L, respectively. A production of 69.5 U/mL was achieved in agreement with the prediction (68.9 U/mL) fermented in 24-deep-well microtiterplates. Furthermore, the fermentation medium optimized in the high-throughput system was verified in shake flasks, and the pigment production could be enhanced from 206.5 U/mL in un-optimized medium to 265.8 U/mL, giving nearly 1.30-fold increase in production.

Decolorization of Reactive Brilliant Blue KN-R by Immobilized Cells of &lt;i&gt;Rhodocyclus gelatinosus&lt;/i&gt;

Reactive Brilliant Blue KN-R is a typical kind of anthraquinone dye and in common use in textile, dyeing, and printing industries in China, which is difficult to degrade because of its conjugated structure. The decolorization of KN-R was investigated using Ca-alginate immobilized cells of Rhodocyclus gelatinosus XL-1 under anaerobic conditions. For KN-R decolorization by immobilized cells, the suitable pH is 5-8 and the suitable temperature is 25-40 °C. Immobilized cells could decolorize KN-R by co-metabolism in the presence of peptone, and the enhancement of peptone concentration was beneficial for anaerobic decolorization. Metal ions affected the metabolic activity of immobilized cells of R. gelatinosus XL-1. The activity of KN-R decolorization was appreciably increased by Mg2+ and Cr3+, but severely inhibited by Cu2+ and Ag+. The maximum absorption peak in visible spectrum shifted from 595 to 453 nm during KN-R decolorization, indicating the formation of the intermediate product.

Bioprocess Design for the Microbial Production of Natural Phenolic Compounds by Debaryomyces hansenii

Debaryomyces hansenii NRRL Y-7426 metabolised ferulic acid into different phenolic compounds using a factorial design where glucose concentration (in the range of 1-20g/L), peptone concentration (2-20g/L) and yeast extract concentration (0.2-10g/L) were the independent variables. The interrelationship between dependent and operational variables was well fitted (R (2) > 0.95) to models including linear, interaction and quadratic terms. Depending on the glucose and nitrogen concentrations, which redirected the metabolism, the major degradation products were 1,226.2mg 4-vinyl guaiacol/L after 72h (molar yield of 86.0%), 1,077.8mg vanillic acid/L after 360h (molar yield of 91.1%) or 1,682.6mg acetovanillone/L after 408h (molar yield of 98.8%) in fermentations carried out with 2,000mg ferulic acid/L. Other metabolites such as vanillin, vanillyl alcohol or 4-ethylguaiacol were present in lower amounts.

STATISTICAL OPTIMIZATION OF BACTERIOCIN PRODUCTION BYPEDIOCOCCUS ACIDILACTICIIN A SIMPLE FOOD-GRADE MEDIUM

Bacteriocins produced by lactic acid bacteria are attractive as food biopreservatives in place of chemical preservatives. Pediococcus acidilactici was found to produce bacteriocin that can inhibit bacterial and fungal food contaminants. Based on the conventional deMan, Rogosa and Sharpe (MRS) medium, simplified food-grade medium for bacteriocin production by the bacterium was developed containing casein peptone and dextrose for food application and scale-up of the bioprocess. Central composite rotatable design was used to study the main and interactive effects of medium components and fermentation parameters, i.e., temperature and pH on bacteriocin production by Pediococcus acidilactici. The optimized medium conditions with 97% desirability under the set criteria were: casein peptone 3.97%, dextrose 3.45% at pH = 7.0 and temperature 35C. Bacteriocin titer obtained from the optimized casein peptone and dextrose medium was comparable with MRS medium (538 AU/mL). Practical Applications Bacteriocins from lactic acid bacteria are of potential usefulness as natural substitutes for chemical food preservatives in the production of food with enhanced shelf-life. The bacteriocin obtained from Pediococcus acidilactici has a wide spectrum of activity against bacterial and fungal food pathogens. Usually, bacteriocins is obtained from deMan, Rogosa and Sharpe medium that contains nitrogen sources such as beef extract, yeast extract, proteose peptone and ammonium citrate that is not acceptable by the consumers. Keeping this in mind, we have developed a food-grade medium containing casein peptone and dextrose for food applications. Further casein peptone and dextrose concentrations along with fermentation parameters such as pH and temperature were optimized to give optimum yield of bacteriocins. So, the bacteriocin produced in the food-grade medium should be acceptable by the consumers as well as economical according to industrial point of view.