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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 profile (r² = 0.9290) for the lytic activity of Aspergillus tamarii as a function of temperature and reaction medium pH.
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fig01: Fitted response profile (r² = 0.9290) for the lytic activity of Aspergillus tamarii as a function of temperature and reaction medium pH.

Mentions: Most studies involving screening for enzymatic activity evaluate this activity in fixed conditions of temperature and pH (Rojas et al. 2009; Cruz Ramírez et al. 2012), since testing different combinations may lead to the need for a very large number of tests. However, tests on fixed conditions may disregard the enzymatic activity manifested in conditions different from those tested. In this study, we used a factorial statistical design (22), which allowed the evaluation of lytic activity in different combinations, involving three levels of temperature and three pH values, enabling check the lytic ability of isolates in different reaction conditions, totaling eight tests for each isolate (Table 1). The statistical design also allowed the generation of a response surface capable of showing, among the conditions tested, those which presented more satisfactory results (Fig. 1).


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 profile (r² = 0.9290) for the lytic activity of Aspergillus tamarii as a function of temperature and reaction medium pH.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig01: Fitted response profile (r² = 0.9290) for the lytic activity of Aspergillus tamarii as a function of temperature and reaction medium pH.
Mentions: Most studies involving screening for enzymatic activity evaluate this activity in fixed conditions of temperature and pH (Rojas et al. 2009; Cruz Ramírez et al. 2012), since testing different combinations may lead to the need for a very large number of tests. However, tests on fixed conditions may disregard the enzymatic activity manifested in conditions different from those tested. In this study, we used a factorial statistical design (22), which allowed the evaluation of lytic activity in different combinations, involving three levels of temperature and three pH values, enabling check the lytic ability of isolates in different reaction conditions, totaling eight tests for each isolate (Table 1). The statistical design also allowed the generation of a response surface capable of showing, among the conditions tested, those which presented more satisfactory results (Fig. 1).

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