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Lytic enzyme production optimization using low-cost substrates and its application in the clarification of xanthan gum culture broth.

da Silva CR, Silva ML, Kamida HM, Goes-Neto A, Koblitz MG - Food Sci Nutr (2014)

Bottom Line: To optimize the clarification process a central composite rotational design was applied in which the pH of the reaction medium, the dilution of the broth, and the reaction temperature were evaluated.The isolate identified as Aspergillus tamarii was selected for increasing the transmittance of the broth from 2.1% to 54.8%.The best conditions for cultivation of this microorganism were: use of coconut husk as solid substrate, with 90% moisture, at 30°C for 20 days.

View Article: PubMed Central - PubMed

Affiliation: State University of Feira de Santana Av. Transnordestina, Novo Horizonte, Feira de Santana, 44036-900, Bahia, Brazil.

ABSTRACT
Lytic enzymes are widely used in industrial biotechnology as they are able to hydrolyze the bacterial cell wall. One application of these enzymes is the clarification of the culture broth for the production of xanthan gum, because of its viability in viscous media and high specificity. The screening process for filamentous fungi producing lytic enzymes, the optimization of production of these enzymes by the selected microorganism, and the optimization of the application of the enzymes produced in the clarification of culture broth are presented in this article. Eleven fungal isolates were tested for their ability to produce enzymes able to increase the transmittance of the culture broth containing cells of Xanthomonas campestris. To optimize the secretion of lytic enzymes by the selected microorganism the following variables were tested: solid substrate, initial pH, incubation temperature, and addition of inducer (gelatin). Thereafter, secretion of the enzymes over time of incubation was assessed. To optimize the clarification process a central composite rotational design was applied in which the pH of the reaction medium, the dilution of the broth, and the reaction temperature were evaluated. The isolate identified as Aspergillus tamarii was selected for increasing the transmittance of the broth from 2.1% to 54.8%. The best conditions for cultivation of this microorganism were: use of coconut husk as solid substrate, with 90% moisture, at 30°C for 20 days. The lytic enzymes produced thereby were able to increase the transmittance of the culture broth from 2.1% to 70.6% at 65°C, without dilution and without pH adjustment.

No MeSH data available.


Related in: MedlinePlus

Fitted response surface (r² = 0.6044) for protease activity secreted by Aspergillus tamarii: temperature (X2) versus percentage of gelatin (X3).  = 1197.197-288.420 x2-420.218 x22 + 234.551 x3.
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fig03: Fitted response surface (r² = 0.6044) for protease activity secreted by Aspergillus tamarii: temperature (X2) versus percentage of gelatin (X3). = 1197.197-288.420 x2-420.218 x22 + 234.551 x3.

Mentions: Figure 3 illustrates the influence of temperature and addition of gelatin in the secretion of proteases by A. tamarii, using coconut fiber as the substrate. The variable temperature showed significant quadratic effect in this experiment (P < 0.01), confirming the previous hypothesis that this influence was not detected by the exploratory experiment because of the narrow range of values tested. The temperature optimum ranged between 20 and 35°C, in agreement with the results obtained by Anandan et al. (2007), Hajji et al. (2008), Vishwanatha et al. (2010), and Thanapimmetha et al. (2012), confirming that the secretion of proteases by various species of Aspergillus, including A. tamarii, is higher at a temperature of 30°C and decreases at higher and lower temperature values. According to Anandan et al. (2007), the incubation temperature has greater influence on processes of solid-state fermentation than on submerged fermentation. This effect is related not only to the regulation of enzyme synthesis but also the secretion of enzymes by the permeabilization of the cell wall. According to Hajji et al. (2008), most filamentous fungi present optimum temperature for enzyme secretion between 28 and 30°C.


Lytic enzyme production optimization using low-cost substrates and its application in the clarification of xanthan gum culture broth.

da Silva CR, Silva ML, Kamida HM, Goes-Neto A, Koblitz MG - Food Sci Nutr (2014)

Fitted response surface (r² = 0.6044) for protease activity secreted by Aspergillus tamarii: temperature (X2) versus percentage of gelatin (X3).  = 1197.197-288.420 x2-420.218 x22 + 234.551 x3.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4221828&req=5

fig03: Fitted response surface (r² = 0.6044) for protease activity secreted by Aspergillus tamarii: temperature (X2) versus percentage of gelatin (X3). = 1197.197-288.420 x2-420.218 x22 + 234.551 x3.
Mentions: Figure 3 illustrates the influence of temperature and addition of gelatin in the secretion of proteases by A. tamarii, using coconut fiber as the substrate. The variable temperature showed significant quadratic effect in this experiment (P < 0.01), confirming the previous hypothesis that this influence was not detected by the exploratory experiment because of the narrow range of values tested. The temperature optimum ranged between 20 and 35°C, in agreement with the results obtained by Anandan et al. (2007), Hajji et al. (2008), Vishwanatha et al. (2010), and Thanapimmetha et al. (2012), confirming that the secretion of proteases by various species of Aspergillus, including A. tamarii, is higher at a temperature of 30°C and decreases at higher and lower temperature values. According to Anandan et al. (2007), the incubation temperature has greater influence on processes of solid-state fermentation than on submerged fermentation. This effect is related not only to the regulation of enzyme synthesis but also the secretion of enzymes by the permeabilization of the cell wall. According to Hajji et al. (2008), most filamentous fungi present optimum temperature for enzyme secretion between 28 and 30°C.

Bottom Line: To optimize the clarification process a central composite rotational design was applied in which the pH of the reaction medium, the dilution of the broth, and the reaction temperature were evaluated.The isolate identified as Aspergillus tamarii was selected for increasing the transmittance of the broth from 2.1% to 54.8%.The best conditions for cultivation of this microorganism were: use of coconut husk as solid substrate, with 90% moisture, at 30°C for 20 days.

View Article: PubMed Central - PubMed

Affiliation: State University of Feira de Santana Av. Transnordestina, Novo Horizonte, Feira de Santana, 44036-900, Bahia, Brazil.

ABSTRACT
Lytic enzymes are widely used in industrial biotechnology as they are able to hydrolyze the bacterial cell wall. One application of these enzymes is the clarification of the culture broth for the production of xanthan gum, because of its viability in viscous media and high specificity. The screening process for filamentous fungi producing lytic enzymes, the optimization of production of these enzymes by the selected microorganism, and the optimization of the application of the enzymes produced in the clarification of culture broth are presented in this article. Eleven fungal isolates were tested for their ability to produce enzymes able to increase the transmittance of the culture broth containing cells of Xanthomonas campestris. To optimize the secretion of lytic enzymes by the selected microorganism the following variables were tested: solid substrate, initial pH, incubation temperature, and addition of inducer (gelatin). Thereafter, secretion of the enzymes over time of incubation was assessed. To optimize the clarification process a central composite rotational design was applied in which the pH of the reaction medium, the dilution of the broth, and the reaction temperature were evaluated. The isolate identified as Aspergillus tamarii was selected for increasing the transmittance of the broth from 2.1% to 54.8%. The best conditions for cultivation of this microorganism were: use of coconut husk as solid substrate, with 90% moisture, at 30°C for 20 days. The lytic enzymes produced thereby were able to increase the transmittance of the culture broth from 2.1% to 70.6% at 65°C, without dilution and without pH adjustment.

No MeSH data available.


Related in: MedlinePlus