scholarly journals Response surface optimization of medium composition for xylitol production by Debaryomyces hansenii var hansenii using corncob hemicellulose hydrolysate

2013 ◽  
Vol 19 (3) ◽  
pp. 377-384 ◽  
Author(s):  
S. Ramesh ◽  
R. Muthuvelayudham ◽  
Rajesh Kannan ◽  
T. Viruthagiri

Optimization of the culture medium for xylitol production using Debrayomyces hansenii var hansenii was carried out. The optimization of xylitol production using corncob hemicelluloses hydrolysate as substrate was performed with statistical methodology based on experimental designs. The screening of nine nutrients for their influence of xylitol production to achieved using a Plackett-Burman design. MgSO4.7H2O, KH2PO4, (NH4)2SO4, yeast extract were selected for based on their positive influence on xylitol production. The selected components were optimized using Response Surface Methodology (RSM). The optimum conditions are: MgSO4.7H2O - 1.02 g/l, (NH4)2SO4 - 3.94 g/l, KH2PO4- 2.74 g/l and yeast extract - 3.45 g/l. These conditions are validated experimentally which revealed an enhanced xylitol yield of 0.76 g/g.

2014 ◽  
Vol 522-524 ◽  
pp. 295-298
Author(s):  
Kai Wang ◽  
Pei Sheng Yan ◽  
Li Xin Cao

Aflatoxins (AFs) are a series of highly toxic and carcinogenic secondary metabolites. In order to eliminate AFs contamination, biological control is one of the more promising techniques. In this study, we describe the optimization of media nutrients for the selected biocontrol bacterium, Lysinibacillus xylanilyticus strain BPM1. The strain was isolated from the peanut hulls in Shandong Province, China and exhibited antagonistic activity against aflatoxins. Maltose and sucrose were identified as best carbon source, while soya peptone and yeast extract as nitrogen source led to the highest OD600 observations. Medium composition was optimized using Plackett-Burman design, which was applied to find the key ingredients. The results revealed that the most significant two factors which were more effective in the fermentation of L. xylanilyticus BPM1 were soya peptone and yeast extract.


2011 ◽  
Vol 17 (2) ◽  
pp. 215-222 ◽  
Author(s):  
P. Rathakrishnan ◽  
P. Nagarajan ◽  
Rajesh Kannan

Optimization of the growth condition for maximum growth rate and protease production was carried out using Bacillus subtilis. The optimization of protease production using agro industrial waste product such as cassava waste as substrate was performed with statistical methodology based on experimental designs. The screening of twelve nutrients for their influence on protease production was achieved using a Plackett-Burman design. MgSO4.7H2O, casein and glucose were selected based on their positive influence on protease production. The selected components were optimized using Response Surface Methodology (RSM). The optimum conditions are (% w/w): MgsO4.7H2O- 0.14, casein- 1.4 and glucose- 2.64. These conditions were validated experimentally which revealed an enhanced protease yield of 202.048 U/gds.


2011 ◽  
Vol 138-139 ◽  
pp. 1209-1214
Author(s):  
Xiao Yu Liu ◽  
Fan Xing Meng ◽  
Yi Bo Zhang ◽  
Huan He ◽  
Wei Han ◽  
...  

Response surface methodology (RSM) was used for statistical optimization of fermentation medium that influenced the yield of endo-polysaccharide from cultivated mycelia of Cordyceps militaris. First, the Plackett-Burman design was used to evaluate the effects of ten variables including glucose, maltose, peptone, yeast extract, KH2PO4, MgSO4, CaCl2, VB1, inoculum density and medium capacity. Among these variables, glucose, peptone and yeast extract were identified to have the significant effects. Subsequently, response surface methodology based on a five-level three-factor central composite design was employed to determine the maximum dry weight (DW) of mycelial biomass at optimum concentration of glucose, peptone and yeast extract. The mycelia growth was found to correlate to the three parameters that could be represented by second-order polynomial models. The optimal values of the three parameters were determined as 4.62% glucose, 3.36% peptone and 0.43% yeast extract. The prediction DW was 23.727g/L. The actual experimental results were in agreement with the prediction.


2017 ◽  
Vol 21 (4) ◽  
pp. 249-260 ◽  
Author(s):  
Maurice George Ekpenyong ◽  
Sylvester Peter Antai ◽  
Atim David Asitok ◽  
Bassey Offiong Ekpo ◽  
◽  
...  

Author(s):  
Durga Rebbapragada ◽  
Rajagopal Kalyanaraman

Objective: To enhance the antioxidant potential of Xylaria feejeensis by statistical optimization. The components of potato dextrose yeast extract (PDYEB) medium: potato infusion, dextrose and yeast extract were investigated to optimize antioxidant activity by Plackett-Burman design (P-B design). The interaction between the critical components of the medium and incubation time was further investigated by Response Surface Method (RSM) and the culture conditions were optimized for enhancing antioxidant activity. Central composite design (CCD) was employed and quadratic response surface model was used to analyze the data using analysis of variance (ANOVA).Methods: The antioxidant potential was measured by 1-1diphenyl-2-picryl-hydrazil (DPPH) radical scavenging assay, nitric oxide (NO) scavenging assay. The antioxidant activity was compared with total phenolic content measured by Folin-Ciocalteau (FC) reagent based assay.Results: Plackett-Burman design revealed dextrose and yeast extract to be the most significant components of PDYEB medium (p<.0001). ANOVA analysis showed that the model was highly significant (p<0.0001) for antioxidant activity measured by DPPH, NO scavenging and TPC (total phenolic content). The model was justified by applying the optimized conditions and values of 87.38%, 56.43%, 27.28 mg/g for DPPH, NO scavenging and TPC respectively were obtained. The estimated optimum conditions of the variables for the antioxidant activity and phenolic content are 12.72g of dextrose, 1.67g yeast extract, and incubation period of 23.43 d.Conclusion: The study highlights the importance of various components of the medium and the physiochemical limitations in antioxidant potential and phenol production of the fungal strain. 


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