scholarly journals SELECTION OF STRAIS PRODUCING FUNGAL CHITOSANASE AND KINETICS

2011 ◽  
Vol 3 ◽  
pp. 56
Author(s):  
Raimundo Cosme Silva Filho ◽  
Sérgio Carvalho Santana ◽  
Naveed Khan Khan ◽  
Everaldo Silvino Santos ◽  
Gorete Ribeiro Marcedo

In this work it was performed a selection of fungal strains able to grow in a specific medium containing chitosan (Chitosan Detector Agar) as the sole carbon source at 0.2%, and a kinetic study was performed to evaluate the best conditions for production of chitosanase from the best producing strain. The selection was made from five strains, previously isolated from soil. In the evaluation of kinetics was accompanied by cell concentration, the protein concentration (mg/mL), the enzyme activity (U/mL) for two volumes of fermentation broth (0.05 and 0.10 mL). The results showed a significant increase in all parameters studied in the first 12 hours of culture. Comparing the activity values for the two volumes of fermentation broth was observed that the volume of 0.05 mL broth showed enzymatic activity always greater than the volume of 0.1 mL

Hoehnea ◽  
2018 ◽  
Vol 45 (1) ◽  
pp. 134-142 ◽  
Author(s):  
Flaviane Lopes Ferreira ◽  
Cesar Barretta Dall'Antonia ◽  
Emerson Andrade Shiga ◽  
Larissa Juliani Alvim ◽  
Rosemeire Aparecida Bom Pessoni

ABSTRACT The aim of the present work was to assess the enzymatic activity of six strains of filamentous fungi grown in liquid media containing 1% sugarcane bagasse as the sole carbon source. All fungal strains were able to use this agro-industrial residue, producing various types of enzymes, such as cellulases, xylanases, amylases, pectinases, and laccases. However, Aspergillus japonicus Saito was the most efficient producer, showing the highest enzymatic activity for laccase (395.73 U L-1), endo-β-1,4-xylanase (3.55 U mL-1) and β-xylosidase (9.74 U mL-1) at seven, fourteen and twenty-one days in culture, respectively. Furthermore, the endo-β-1,4-xylanases and β-xylosidases of A. japonicus showed maximum activity at 50°C, and pH 5.5 and pH 3.5-4.5, respectively. Thus, these results indicate that A. japonicus has a great biotechnological potential for the production of these enzymes using sugarcane bagasse as the sole source of carbon.


2020 ◽  
Vol 367 (10) ◽  
Author(s):  
Rodolfo García-Contreras ◽  
Daniel Loarca ◽  
Caleb Pérez-González ◽  
J Guillermo Jiménez-Cortés ◽  
Abigail Gonzalez-Valdez ◽  
...  

ABSTRACT Pseudomonas aeruginosa is one of the main models to study social behaviors in bacteria since it synthesizes several exoproducts, including exoproteases and siderophores and release them to the environment. Exoproteases and siderophores are public goods that can be utilized by the individuals that produce them but also by non-producers, that are considered social cheaters. Molecularly exoprotease cheaters are mutants in regulatory genes such as lasR, and are commonly isolated from chronic infections and selected in the laboratory upon serial cultivation in media with protein as a sole carbon source. Despite that the production of exoproteases is exploitable, cooperators have also ways to restrict the growth and selection of social cheaters, for instance by producing toxic metabolites like pyocyanin. In this work, using bacterial competitions, serial cultivation and growth assays, we demonstrated that rhamnolipids which production is regulated by quorum sensing, selectively affect the growth of lasR mutants and are able to restrict social cheating, hence contributing to the maintenance of cooperation in Pseudomonas aeruginosa populations.


2009 ◽  
Vol 25 ◽  
pp. S69
Author(s):  
A. Loredo-Treviño ◽  
J.A. Sánchez-Vasquez ◽  
R. Rodríguez-Herrera ◽  
C. Aguilar

1996 ◽  
Vol 42 (1) ◽  
pp. 87-91 ◽  
Author(s):  
ESTEBAN C. DELL'ANGELICA ◽  
DANIEL MILIKOWSKI ◽  
DANIEL A. SAENZ ◽  
CARLOS A. STELLA ◽  
EUGENIA H. RAMOS ◽  
...  

2005 ◽  
Vol 60 (11-12) ◽  
pp. 844-848 ◽  
Author(s):  
Mario Cruz Hernández ◽  
Juan Carlos Contreras Esquivel ◽  
Faustino Lara ◽  
Raúl Rodríguez ◽  
Cristóbal N. Aguilar

Eleven fungal strains (4 Penicillium commune, 2 Aspergillus niger, 2 Aspergillus rugulosa, Aspergillus terricola, Aspergillus ornatus and Aspergillus fumigatus) were isolated, characterized morphologically and by their capacity to degrade tannins. Aspergillus niger Aa-20 was used as control strain. Several concentrations of hydrolysable tannin (tannic acid) were used as sole carbon source. All strains were able to degrade hydrolysable tannins. Aspergillus niger GH1 and PSH showed the highest tannin-degrading capacity (67 and 70%, respectively). Also, the fungal capacity to degrade condensed tannin (catechin) was tested. Aspergillus niger PSH and Penicillium commune EH2 degraded 79.33% and 76.35% of catechin. The results demonstrated the capacity of fungi to use hydrolysable and condensed tannins as carbon source.


Author(s):  
Vivek Kumar Ranjan ◽  
Shriparna Mukherjee ◽  
Subarna Thakur ◽  
Krutika Gupta ◽  
Ranadhir Chakraborty

2008 ◽  
Vol 5 (4) ◽  
pp. 367-374 ◽  
Author(s):  
Jing Wang ◽  
Guiwen Yan ◽  
Mingquan An ◽  
Jieli Liu ◽  
Houming Zhang ◽  
...  

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