scholarly journals Identification of cholesterol-assimilating actinomycetes strain and application of statistical modeling approaches for improvement of cholesterol oxidase production by Streptomyces anulatus strain NEAE-94

2019 ◽  
Author(s):  
Noura El-Ahmady El-Naggar ◽  
Nancy M. El-Shweihy

Abstract Background Cholesterol oxidase biosensors have been applied to detect cholesterol level in different in serum and foods samples. Due to a wide range of industrial and clinical applications of microbial cholesterol oxidase, isolation and detection of new microbial source (s) of cholesterol oxidase are very important.Results Among the potential strains, Streptomyces sp. strain NEAE-94 was chosen and identified based on cultural, morphological and physiological characteristics; in addition to the 16S rRNA sequence which had been deposited in the GenBank database under the accession number KC354803. Cholesterol oxidase production in shake flask by Streptomyces anulatus strain NEAE-94 was optimized using response surface methodology. The production parameters were first screened using a Plackett-Burman design and the parameters with significant effects on the production of cholesterol oxidase were identified. Out of the fifteen factors screened, agitation speed, cholesterol and yeast extract concentration were selected due to significant positive effects on the production of cholesterol oxidase. The optimal levels of these variables and the effects of their mutual interactions on cholesterol oxidase production were determined using Box-Behnken design. The maximum cholesterol oxidase activity (27.31 U/mL) was achieved at cholesterol concentration (4 g/L), the agitation speed (150 rpm/min) and yeast extract concentration (5 g/L). In comparison with cholesterol oxidase production by Streptomyces anulatus strain NEAE-94 before the application of Plackett-Burman design, the statistical optimization resulted in an increased production by 4.66 times.Conclusions The maximal cholesterol oxidase activity is obtained at the following fermentation conditions: g/L (cholesterol 4, yeast extract 5, NaCl 0.5, K 2 HPO 4 1, FeSO 4 .7H 2 O 0.01, MgSO 4 .7H 2 O 0.5), pH 7, inoculum size 4% (v/v), temperature 37°C, agitation speed 150 rpm/min, medium volume 100 mL and incubation time 5 days.

2020 ◽  
Author(s):  
Noura El-Ahmady El-Naggar ◽  
Nancy M. El-Shweihy

Abstract Background: Cholesterol oxidase biosensors have been used to determine the level of cholesterol in different serum and food samples. Due to a wide range of industrial and clinical applications of microbial cholesterol oxidase, isolation and identification of a new microbial source (s) of cholesterol oxidase are very important. Results: The local isolate Streptomyces sp. strain NEAE-94 is a promising source of cholesterol oxidase. It was identified based on cultural, morphological and physiological characteristics; in addition to the 16S rRNA sequence. The sequencing product had been deposited in the GenBank database under the accession number KC354803. Cholesterol oxidase production by Streptomyces anulatus strain NEAE-94 in shake flasks was optimized using surface response methodology. The different process parameters were first screened using a Plackett-Burman design and the parameters with significant effects on the production of cholesterol oxidase were identified. Out of the fifteen factors screened, agitation speed, cholesterol and yeast extract concentrations had the most significant positive effects on the production of cholesterol oxidase. The optimal levels of these variables and the effects of their mutual interactions on cholesterol oxidase production were determined using Box-Behnken design. Cholesterol oxidase production by Streptomyces anulatus strain NEAE-94 was 11.03, 27.31 U/mL after Plackett-Burman Design and Box-Behnken design; respectively, with a fold of increase of 6.06 times compared to the production before applying the Plackett-Burman design (4.51 U/mL). Conclusions: Maximum cholesterol oxidase activity is obtained at the following fermentation conditions: g/L (cholesterol 4, yeast extract 5, NaCl 0.5, K 2 HPO 4 1, FeSO 4 .7H 2 O 0.01, MgSO 4 .7H 2 O 0.5), pH 7, inoculum size 4 % (v/v), temperature 37°C, agitation speed 150 rpm, medium volume 50 mL and incubation time 5 days.


2020 ◽  
Author(s):  
Noura El-Ahmady El-Naggar ◽  
Nancy M. El-Shweihy

Abstract Background: Cholesterol oxidase biosensors have been used to determine the level of cholesterol in different serum and food samples. Due to a wide range of industrial and clinical applications of microbial cholesterol oxidase, isolation and identification of a new microbial source (s) of cholesterol oxidase are very important. Results: The local isolate Streptomyces sp. strain NEAE-94 is a promising source of cholesterol oxidase. It was identified based on cultural, morphological and physiological characteristics; in addition to the 16S rRNA sequence. The sequencing product had been deposited in the GenBank database under the accession number KC354803. Cholesterol oxidase production by Streptomyces anulatus strain NEAE-94 in shake flasks was optimized using surface response methodology. The different process parameters were first screened using a Plackett-Burman design and the parameters with significant effects on the production of cholesterol oxidase were identified. Out of the fifteen factors screened, agitation speed, cholesterol and yeast extract concentrations had the most significant positive effects on the production of cholesterol oxidase. The optimal levels of these variables and the effects of their mutual interactions on cholesterol oxidase production were determined using Box-Behnken design. Cholesterol oxidase production by Streptomyces anulatus strain NEAE-94 was 11.03, 27.31 U/mL after Plackett-Burman Design and Box-Behnken design; respectively, with a fold of increase of 6.06 times compared to the production before applying the Plackett-Burman design (4.51 U/mL). Conclusions: Maximum cholesterol oxidase activity is obtained at the following fermentation conditions: g/L (cholesterol 4, yeast extract 5, NaCl 0.5, K 2 HPO 4 1, FeSO 4 .7H 2 O 0.01, MgSO 4 .7H 2 O 0.5), pH 7, inoculum size 4 % (v/v), temperature 37°C, agitation speed 150 rpm, medium volume 50 mL and incubation time 5 days.


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 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.


Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4784 ◽  
Author(s):  
Nucharee Juntarachot ◽  
Duangporn Kantachote ◽  
Sartjin Peerajan ◽  
Sasithorn Sirilun ◽  
Chaiyavat Chaiyasut

Dextranase catalyzes the degradation of the substrate dextran, which is a component of plaque biofilm. This enzyme is involved in antiplaque accumulation, which can prevent dental caries. The activity of crude dextranase from Penicillium roquefortii TISTR 3511 was assessed, and the maximum value (7.61 unit/g) was obtained at 37 °C and pH 6. The Plackett–Burman design was used to obtain significant factors for enhancing fungal dextranase production, and three influencing factors were found: Dextran, yeast extract concentration and inoculum age. Subsequently, the significant factors were optimized with the Box–Behnken design, and the most suitable condition for dextranase activity at 30.24 unit/g was achieved with 80 g/L dextran, 30 g/L yeast extract and five day- old inoculum. The use of 0.85% alginate beads for encapsulation exhibited maximum dextranase activity at 25.18 unit/g beads, and this activity was stable in toothpaste for three months of testing. This study explored the potential production of fungal dextranase under optimal conditions and its encapsulation using alginate for the possibility of applying encapsulated dextranase as an additive in toothpaste products for preventing dental caries.


INDIAN DRUGS ◽  
2015 ◽  
Vol 52 (06) ◽  
pp. 24-32
Author(s):  
N Kasinathan ◽  
◽  
V. M. Subrahmanyam ◽  
V. R Josyula

Chondroitinases are useful in treating cancer and spinal cord injuries. The work reported so far does not focus on production of fungal chondroitinase. The present study focuses on the optimization of cultural conditions using design of experiments for production of chondroitinase by a fungal isolate CHCS-2, obtained from humus containing poultry waste. The cultural conditions were optimized systematically using a one-factor-at-a-time (OFAT) approach, factorial design, Plackett-Burman design (PBD) and Box- Behnken design to identify the composition of the production medium and the level of the variables. The level of significance of the medium components selected by OFAT study viz., yeast extract, chondroitin, and phosphate, was analyzed by factorial studies. The effect of eleven minerals on the enzyme yield was studied by PBD. The interaction among the medium components selected using factorial and PBD viz., yeast extract, cobalt and aluminum was investigated using the Box-Behnken design (BBD). Under the optimized conditions, maximum chondroitinase yield was 22.5 U/mL.


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. 


2020 ◽  
Vol 10 (11) ◽  
pp. 3850
Author(s):  
Izabela Cielecka ◽  
Małgorzata Ryngajłło ◽  
Stanisław Bielecki

The application of bacterial cellulose (BNC) could be widely expanded if the production costs were reduced. This study aims to determine factors simultaneously affecting the yield and tensile strength of BNC in a newly designed surface air-flow bioreactor (SAF). For this purpose, a two-stage study was done. Firstly, the most important factors for high yield were determined based on the Plackett–Burman Design. Secondly, impact of the chosen variables on both responses was assessed in a wide range of factor values. The greatest influence on the yield and mechanical strength was proved for such factors as air-flow ratio, glucose concentration, and culture time. The productivity in a SAF bioreactor with controlled air-flow ratio was enhanced by 65%. In terms of mechanical properties, the stress of BNC membranes varied from 0.8 to 6.39 MPa depending on the culture conditions. The results of the performed tests make a useful basis for future optimizations.


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 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Vinayagam Ramesh ◽  
Vytla Ramachandra Murty

Glucoamylase is an industrially important enzyme which converts soluble starch into glucose. The media components for the production of glucoamylase from thermophilic fungus Humicola grisea MTCC 352 have been optimized. Eight media components, namely, soluble starch, yeast extract, KH2PO4, K2HPO4, NaCl, CaCl2, MgSO4·7H2O, and Vogel’s trace elements solution, were first screened for their effect on the production of glucoamylase and only four components (soluble starch, yeast extract, K2HPO4, and MgSO4·7H2O) were identified as statistically significant using Plackett-Burman design. It was fitted into a first-order model (R2=0.9859). Steepest ascent method was performed to identify the location of optimum. Central composite design was employed to determine the optimum values (soluble starch: 28.41 g/L, yeast extract: 9.61 g/L, K2HPO4: 2.42 g/L, and MgSO4·7H2O: 1.91 g/L). The experimental activity of 12.27 U/mL obtained was close to the predicted activity of 12.15. High R2 value (0.9397), low PRESS value (9.47), and AARD values (2.07%) indicate the accuracy of the proposed model. The glucoamylase production was found to increase from 4.57 U/mL to 12.27 U/mL, a 2.68-fold enhancement, as compared to the unoptimized medium.


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