Ethanol production from cashew apple juice using statistical designs

Ethanol production using jaggery was enhanced in submerged fermentation when the effect of metal inducers was studied using the Plackett-Burman and Box-Behnken designs. Saccharomyces cerevisiae (NCIM 3288) was used as the fermenting organism. The Plackett-Burman design was used to initially screen seven of which the four elements were found to have significant effect on ethanol production. In the next stage, Box-Behnken design was used obtain concentrations of metal ion’s that may be supplemented to get maximum ethanol in during production process. It was observed that ethanol yield has increased to 94.8 from 75.4g/l when supplemented with the critical concentrations of salts provided by the model. These were as follows (g/l): FeSO4. 7H2O 0.0036, MgSO4.7H2O 0.0033, MnCl2. 4H2O 0.0017 and ZnSO4.7H2O 0.0026, in the presence of 220 g/l of jaggery supplemented with (NH4)2SO4 2.612 g/l and KH2PO4 3.407 g/l, while the predicted concentration of ethanol as per the model is 95.35 g/l. Key words: Jaggery, ethanol, Plackett-Burman design, Box-Behnken design, metal inducers.

Optimization of low-cost medium for very high gravity ethanol fermentations by Saccharomyces cerevisiae using statistical experimental designs

Ethanol is believed to be one of the best alternatives to replace gasoline, because ethanol is a renewable energy source and environmentally friendly. The present study focuses on the optimization of palmyra sap as a source for ethanol production. Statistical experimental design using Box-Wilson central composite design (CCD) was used to optimize the quantitative effects of sugar, urea, and inoculum concentration on ethanol production. It was found that palmyra sap could be used as a substrate for ethanol production using Zymomonas mobilis (NRRL B-14234). A maximum ethanol concentration of 58.97 g L-1 was obtained after optimizing the parameters of fermentation. The optimum values of sugar, urea, and inoculums concentration were 206.01 g L-1, 3.16 g L-1, and 23.05% (v v-1), respectively, with ethanol yield of 0.3039 g g-1. A high similarity was observed between the predicted and experimental results, which reflected the accuracy and applicability of RSM to optimize the process for ethanol production.

Augmented cellulase production by Bacillus subtilis strain MU S1 using different statistical experimental designs.

The optimization of supplementary nutrients in the sewage sludge as a basal medium was carried out to determine the media components on the citric acid production. Two statistical designs were employed in the citric acid productions which are Plackett-Burman and central composite design (CCD). For the media screening, the two-level Plackett-Burman was applied. Under the experimental conditions, it was observed that total suspended solids of sewage sludge (TSS), sugar, cassava, methanol, potassium di-hydrogen phosphate and urea to be the major factors in maximizing citric acid production. A study of single factor was conducted to find the optimum ranges of parameters for citric acid production followed by the central composite design (CCD) under the responses surface methodology. A polynomial model was created to correlate the relationship between two factors (sewage sludge TSS and sugar) and citric acid production. The optimum yield of citric acid, 29.12 g/L was produced with 0.8% TSS sewage sludge and 7% sugar in four days of fermentation. The determination of coefficient (R2) from the analysis was 0.9527, indicating that the model of this experiment is significant.

In this paper, we have attempted optimization of production of enzyme carboxymethylcellulase or endoglucanase from the bacterium Bacillus amyloliquefaciens SS35. Optimization has been carried out in two stages using statistical experimental design, viz. medium optimization and optimization of fermentation parameters. For medium optimization, Plackett–Burman design followed by central composite design (CCD) was used, while for optimization of fermentation parameters one-variable-at-a-time method followed by CCD was used. Carbon and nitrogen sources in the medium have been revealed to be the significant factors for enzyme production (carboxymethylcellulose 18.05 g/L; yeast extract 8 g/L and peptone 2 g/L). The inorganic salts have been found to be insignificant components of medium. Optimum fermentation parameters for optimized medium were: initial medium pH 5.65, incubation temperature = 40 °C, shaking speed = 120 rpm, and inoculum size = 6.96 %, v/v. Interestingly, the influence of all four parameters was almost independent with no interlinks. Secondly, the overall effect of all parameters was also low, as indicated by linear, square and interaction regression coefficients that were at least one order of magnitude lower than the intercept in the model equation. These results essentially meant that medium components dominate overall enzyme production process in comparison to fermentation parameters.Electronic supplementary materialThe online version of this article (doi:10.1007/s13205-013-0169-6) contains supplementary material, which is available to authorized users.

In this work, the effect of initial sugar concentration and temperature on the production of ethanol by Saccharomyces cerevisiae CCA008, a flocculent yeast, using cashew apple juice in a 1L-bioreactor was studied. The experimental results were used to develop a kinetic model relating biomass, ethanol production and total reducing sugar consumption. Monod, Andrews, Levenspiel and Ghose and Tyagi models were investigated to represent the specific growth rate without inhibition, with inhibition by substrate and with inhibition by product, respectively. Model validation was performed using a new set of experimental data obtained at 34°C and using 100gL-1 of initial substrate concentration. The model proposed by Ghose and Tyagi was able to accurately describe the dynamics of ethanol production by S. cerevisiae CCA008 growing on cashew apple juice, containing an initial reducing sugar concentration ranging from 70 to 170gL-1 and temperature, from 26 to 42°C. The model optimization was also accomplished based on the following parameters: percentage volume of ethanol per volume of solution (%V ethanol/V solution), efficiency and reaction productivity. The optimal operational conditions were determined using response surface graphs constructed with simulated data, reaching an efficiency and a productivity of 93.5% and 5.45gL-1h-1, respectively.

L‐Asparaginase is a therapeutic enzyme widely used as an antitumor agent for the treatment of acute lymphoblastic leukemia and lymphosarcoma. Its potential applications as a therapeutic agent and food additive require production at high yields in a low‐cost medium with high purity and stability. Statistical experimental designs were applied to identify and optimize the significant parameters for the fermentative production of L‐asparaginase by Pectobacterium carotovorum Microbial Type Culture Collection (MTCC) 1428. Screening of different carbon sources identified galactose as the best carbon source for the production of L‐asparaginase. Twelve medium components were selected and sixteen experiments were carried out based on the Plackett–Burman (PB) design for identifying the most significant medium components. Yeast extract, galactose, monosodium glutamate, MgSO4.7H2O and CaCl2.2H2O were found to be the most significant components that affected the production of L‐asparaginase, and they were optimized by response surface methodology (RSM) using central composite design. This optimized medium showed maximum production rates of periplasmic and extracellular L‐asparaginase of 3.25 and 0.83 U ml−1, respectively. The periplasmic L‐asparaginase production in the optimized medium was twofold higher than in the basal medium. Unstructured kinetic models were applied and satisfactorily described the cell growth, product formation and substrate utilization profile, thus providing a better understanding and prediction of the fermentation profile. This paper details the application of PB experimental design and RSM for the optimization of L‐asparaginase production from Pe. carotovorum MTCC 1428 in submerged fermentation. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.

Background: Application of potassium ferrate is a chemical oxidation approach used for water and wastewater treatment. The aim of this study is to apply central composite design (CCD) and response surface methodology (RSM) to optimize potassium ferrate consumption in the treatment of wastewater from carpet industries. Methods: Samples in this experimental study were collected from wastewater, originating from a carpet factory. Wastewater sampling was carried out monthly for a period of two seasons. Ferrate oxidation experiments were conducted by means of a conventional jar-test apparatus. The time and speed for mixing were set with an automatic controller. Parameters of study were measured based on given methodologies in Standard method for examining water and wastewater. CCD and RSM were applied to optimize the operating variables including potassium ferrate dosage and pH. Results: Results showed that potassium ferrate concentration (A), pH (B), their interactions (AB) and quadratic effects (A2 and B2) were significant in the removal of COD, turbidity, color and TSS from carpet industries effluents. At an optimum point (COD: 160 mg/L of potassium ferrate and pH 4, turbidity: 165 mg/L of potassium ferrate and pH 4, color and TSS: pH 4.5 and 150 mg/L of potassium ferrate) removal efficiencies for COD, turbidity, color and TSS were 86, 86, 87 and 89%, respectively. Conclusion: Potassium ferrate has a significant impact on pollutants decomposition and the removal of color from wastewater produced in carpet industries. This process can be employed for the pretreatment or post treatment of wastewaters containing refractory organic pollutants. CCD and RSM are suitable tools for experimental design. Keywords: Advanced treatment, carpet wastewater, Statistical experiment design, Response Surface Methodology

Production of cell-bound phytase by Pichia anomala in an economical cane molasses medium: Optimization using statistical tools

Pressmud, a by-product from the sugarcane industry, was used as a carbon source for the production of inulinase in solid-state fermentation (SSF). Statistical experimental designs were employed to screen the nutrients and optimize the media composition for the production of inulinase by Kluyveromyces marxianus var. marxianus. Eighteen various nutrients were selected for preliminary screening of production medium component by Plackett–Burman design (PBD) technique. Five nutrients were found to be significant for inulinase production and they were optimized by central composite design (CCD). The optimal media components for solid-state fermentation of inulinase using pressmud were (g/gds): corn steep liquor, 0.06072; urea, 0.01916; beef extract, 0.00957; FeSO4 · 7H2O, 0.00013; K2HPO4, 0.00441. The effect of moisture content and substrate concentration was also studied. From the results it was found that a maximum inulinase activity of 288 U/gds occurs at the moisture content of 65% and substrate concentration of 10 g. The constants in the Michaelis–Menten equation were evaluated and a high R 2 value implied the fitness of the model. Artificial neural network (ANN) modeling was also employed to predict the inulinase production.

Plastic pollution, resulting from the persistence of conventional polymers, remains a critical environmental challenge that necessitates the development of biodegradable alternatives. Polyhydroxyalkanoates (PHAs) represent an attractive solution, being naturally synthesized by microorganisms under nutrient-limited conditions. This study investigates the production of PHAs using lignocellulosic wood waste, specifically sal and teak residues, as an economical carbon source. Fermentable sugars were obtained via dilute sulfuric acid hydrolysis (10% w/v biomass with 4% v/v H2SO4), incubated at 120°C for 1h, and filtered to yield a hydrolysate containing approximately ~ 36mg/mL total reducing sugars (DNS assay). The hydrolysate served as the carbon source in bioprocess optimization (optimal carbon concentration: 2.50%, equivalent to 25g/L). Potential PHA-producing isolates were screened using Nile Blue and Sudan Black staining. The most efficient producer, Klebsiella pneumoniae strain DSM 30,104 (MK2023), confirmed through 16S rRNA sequencing, demonstrated notable PHA accumulation. Process parameters-including carbon and nitrogen concentrations and Temperature-were optimized through Plackett-Burman Design (PBD) followed by Response Surface Methodology (RSM) using a face-centered central composite design. Optimal production was achieved at 2.50% carbon, 0.105% nitrogen, and 34°C, yielding 5.7mg/mL PHA after 72h with 10% (v/v) inoculum. UV-Vis and FTIR analyses confirmed the polymer's identity as polyhydroxybutyrate (PHB). The study highlights wood waste as a viable, low-cost substrate for PHA synthesis, promoting sustainable biopolymer production while advancing circular bioeconomy practices.

Optimization using response surface methodology and kinetic study of Fischer–Tropsch synthesis using SiO2 supported bimetallic Co–Ni catalyst

Paenibacillus sp. 1-49 is a nitrogen-fixing bacterium that has the potential as a fertilizer. However, it grows poorly (OD600≤1) in both mineral medium and rich medium. To achieve high-yield biomass, we optimized fermentation medium for Paenibacillus sp. 1-49. Plackett-Burman Design and Central Composite Design in response surface methodology were used to optimize medium composition. The optimal fermentation medium contained:(per liter) 36.22 g Sucrose, 5.31 g Tryptone, 10.92 g Yeast Extract, 0.51 g MgSO4, 3.5 g NaCl, 0.02 g Na2MoO4 and 0.02 g FeSO4. The maximum OD600 of 10.280±0.009 was obtained in shake flask fermentation, reached 94.6% of the predicted value. We succeeded in using a response surface methodology to optimize the fermentation medium for Paenibacillus sp. 1-49. Our results will be useful for largescale fermentation of this strain and other Paenibacillus spp.

Statistical optimization of fermentative hydrogen production from xylose by newly isolated Enterobacter sp. CN1