Laccase/HBT and laccase-CBM/HBT treatment of softwood kraft pulp: impact on pulp bleachability and physical properties.

Pycnoporus cinnabarinus laccase and a chimeric laccase-CBM were applied in softwood kraft pulp biobleaching in the presence of 1-hydroxybenzotriazole (HBT). The presence of CBM could enhance the laccase biobleaching potential as a decrease in the enzymatic charge and chlorine dioxide consumption, as well as an increase in pulp brightness were observed. Laccase/HBT treatment could be improved by increasing oxygen pressure from 1 to 3bar and pulp consistency from 5% to 10%.

Test procedures for obtaining representative extracts suitable for reliable in vitro toxicity assessment of paper and board intended for food contact.

This paper describes the use of a suite of extraction procedures applicable to the assessment of the in vitro toxicity of paper/board samples intended for food-contact applications. The sample is extracted with ethanol, water, or exposed to modified polyphenylene oxide (Tenax) for fatty, non-fatty and dry food applications, respectively. The water extracts are directly suitable for safety assessment using in vitro bioassays.

Fusion of a family 1 carbohydrate binding module of Aspergillus niger to the Pycnoporus cinnabarinus laccase for efficient softwood kraft pulp biobleaching.

Pycnoporus cinnabarinus laccase was fused to the C-terminal linker and carbohydrate binding module (CBM) of Aspergillus niger cellobiohydrolase B (CBHB). The chimeric enzyme of molecular mass 100 kDa was successfully produced in A. niger.

Secretome analysis of Phanerochaete chrysosporium strain CIRM-BRFM41 grown on softwood.

Proteomic analysis was performed to determine and differentiate the composition of the secretomes of Phanerochaete chrysosporium CIRM-BRFM41, a peroxidase hypersecretory strain grown under ligninolytic conditions and on softwood chips under biopulping conditions. Extracellular proteins from both cultures were analyzed by bidimensional gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry. A total of 37 spots were identified.

The BIOSAFEPAPER project for in vitro toxicity assessments: preparation, detailed chemical characterisation and testing of extracts from paper and board samples.

Nineteen food contact papers and boards and one non-food contact board were extracted following test protocols developed within European Union funded project BIOSAFEPAPER. The extraction media were either hot or cold water, 95% ethanol or Tenax, according to the end use of the sample. The extractable dry matter content of the samples varied from 1200 to 11,800 mg/kg (0.