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1.
Appl Biochem Biotechnol ; 166(6): 1575-85, 2012 Mar.
Article in English | MEDLINE | ID: mdl-22328248

ABSTRACT

In the present paper, endo-ß-1,4-xylanase production by Aspergillus fumigatus was evaluated in solid-state fermentation using low-cost substrates such as sugarcane bagasse (SCB), brewer's spent grain (BSG), and wheat bran (WB). The partial characterization of the crude enzyme was also performed. In the experimental conditions, the highest levels of endo-ß-1,4-xylanase production by A. fumigatus FBSPE-05 occurred within 8 days incubation when using SCB/liquid medium at 1:2 ratio (219.5 U g(-1)) and 4 days incubation when using WB/liquid medium at 1:1 ratio (215.6 U g(-1)). Crude enzyme from this last condition was used to enzyme characterization, showing best enzyme activity at 60 °C and pH 6.0, which suggests a thermophilic endoxylanase. The crude enzyme retained 73% of its activity after 1 h at 60 °C, and zymogram has shown three bands of endo-ß-1,4-xylanase activity, with different molecular masses. A. fumigatus FBSPE-05 was able to grow and produce good levels of endo-ß-1,4-xylanase using agro-industrial by-products, making this strain worthy for further investigation. To our knowledge, this is the first study reporting the use of SCB and/or BSG as sole substrates for endoxylanase production by solid-state fermentation using A. fumigatus.


Subject(s)
Aspergillus fumigatus/enzymology , Crops, Agricultural/metabolism , Endo-1,4-beta Xylanases/biosynthesis , Aspergillus fumigatus/drug effects , Cellulose/metabolism , Culture Media/metabolism , Dietary Fiber/metabolism , Edetic Acid , Enzyme Activation , Enzyme Assays , Enzyme Stability , Fermentation , Hydrogen-Ion Concentration , Saccharum/metabolism , Time Factors
2.
Appl Biochem Biotechnol ; 155(1-3): 321-9, 2009 May.
Article in English | MEDLINE | ID: mdl-19127443

ABSTRACT

This study evaluated the production of cellulolytic enzymes by an Aspergillus fumigatus strain, isolated from sugar cane bagasse, according to its ability to grow on microcrystalline cellulose as the sole carbon source. The effect of the carbon source (brewer's spent grain, sugarcane bagasse, and wheat bran) and of the nitrogen source (corn steep liquor and sodium nitrate) on cellulase production was studied using submerged and solid state cultivations at 30 degrees C. The highest levels of endoglucanase (CMCase) corresponded to 365 U L(-1) and was obtained using sugarcane bagasse (1%) and corn steep liquor (1.2%) in submerged fermentation within 6 days of cultivation. This supernatant was used to run a sodium dodecyl sulfate polyacrylamide gel electrophoresis that showed six bands with endoglucanase activity. CMCase activity was higher at 65 degrees C and pH 2.0, indicating that this microorganism produces a thermophilic and acid endoglucanase. Solid state cultivation favored FPase production, that reached 47 U g(-1) of dry substrate (wheat bran and sugarcane bagasse) within 3 days.


Subject(s)
Aspergillus fumigatus/enzymology , Cellulase/metabolism , Cellulose/metabolism , Dietary Fiber/metabolism , Saccharum/microbiology , Substrate Specificity
3.
Rev Bras Enferm ; 52(4): 504-13, 1999.
Article in Portuguese | MEDLINE | ID: mdl-12138429

ABSTRACT

The objective of this investigation is to evaluate the procedure used for disinfecting patients' rooms, as well as to detect and indicate possible mistakes in this process. The results obtained through interviews with nursing professionals responsible for the Nursing Services reveal that the procedures used in the studied hospitals are not following the principles required by the literature. As a consequence there is little reliability concerning disinfecting procedures in those hospitals.


Subject(s)
Disinfection , Hospitals/standards
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