Analysis of the genome of the human pathogen, Aspergillus fumigatus, revealed the presence of several putative glutathione transferase (GST) open reading frames. Three A. fumigatus GST genes, termed gstA, B, and C, were cloned and recombinant proteins expressed in Escherichia coli. Functional analysis of recombinant gstA-C conWrms that the enzymes exhibit GST activity and glutathione peroxidase activity. RT-PCR conWrmed low basal expression of gstA and gstC which was markedly up-regulated (at least 4£-10£) in the presence of either H 2 O 2 or 1-chloro-2,4-dinitrobenzene (CDNB). GstB expression was only observed in the presence of CDNB. These results demonstrate for the Wrst time the existence of three functional GSTs in A. fumigatus and strongly suggest a role for these enzymes in the response of the organism to both oxidative stress and xenobiotic presence. 

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Cellulose paper has been extensively used in microfluidic analytical devices because of its hydrophilic nature. However, cellulose is randomly packed in paper without any particular orientation or channels within the bulk of the material, necessitating a complicated design of hydrophilic microchannels to guide the liquid flow. Herein, we develop an anisotropic mesoporous microfluidic framework (named as white wood) with aligned cellulose nanofibers and inherent microchannels via a facile one-step delignification process from natural wood. The hydrophilic nature of the innate microchannels in white wood makes it ideal for application as a pump-free microfluidic chip, exhibiting a fast and anisotropic liquid and large solid particle (as demonstrated with carbon nanotubes) mass transport, with a high transport speed along the channel direction approximately five times faster than that perpendicular to the channel direction. The anisotropic mass transport is further exemplified in the fabrication of chitosan films with aligned microstructures and birefringence, formed by virtue of unidirectional capillary forces exerted by the microchannels. We envision that our anisotropic mesoporous framework can have great applications to pump-free microfluidics, and the simple preparation process will pave a new way for the development of microfluidic devices based on chemically modified wood.

Aspergillus fumigatus is a significant human pathogen. Non‐ribosomal peptide (NRP) synthesis is thought to be responsible for a significant proportion of toxin and siderophore production in the organism. Furthermore, it has been shown that 4′‐phosphopantetheinylation is required for the activation of key enzymes involved in non‐ribosomal peptide synthesis in other species. Here we report the cloning, recombinant expression and functional characterisation of a 4′‐phosphopantetheinyl transferase from A. fumigatus and the identification of an atypical NRP synthetase (Afpes1), spanning 14.3 kb. Phylogenetic analysis has shown that the NRP synthetase exhibits greatest identity to NRP synthetases from Metarhizium anisolpiae (PesA) and Alternaria brassicae (AbrePsy1). Northern hybridisation and RT‐PCR analysis have confirmed that both genes are expressed in A. fumigatus. A 120 kDa fragment of the A. fumigatus NRP synthetase, containing a putative thiolation domain, was cloned and expressed in the baculovirus expression system. Detection of a 4′‐phosphopantetheinylated peptide (SFSAMK) from this protein, by MALDI‐TOF mass spectrometric analysis after coincubation of the 4′‐phosphopantetheinyl transferase with the recombinant NRP synthetase fragment and acetyl CoA, confirms that it is competent to play a role in NRP synthetase activation in A. fumigatus. The 4′‐phosphopantetheinyl transferase also activates, by 4′‐phosphopantetheinylation, recombinant α‐aminoadipate reductase (Lys2p) from Candida albicans, a key enzyme involved in lysine biosynthesis.

Cellulose-based filter papers were used as base materials to construct microfluidic paper-based analytical devices (μPADs) coupling a separation channel with electrochemical detection.