Sophie Vanhulle

Laccases: a never-ending story

Laccases (benzenediol:oxygen oxidoreductases, EC 1.10.3.2) are blue multicopper oxidases that catalyze the oxidation of an array of aromatic substrates concomitantly with the reduction of molecular oxygen to water. In fungi, laccases carry out a variety of physiological roles during their life cycle. These enzymes are being increasingly evaluated for a variety of biotechnological applications due to their broad substrate range. In this review, the most recent studies on laccase structural features and catalytic mechanisms along with analyses of their expression are reported and examined with the aim of contributing to the discussion on their structure–function relationships. Attention has also been paid to the properties of enzymes endowed with unique characteristics and to fungal laccase multigene families and their organization.

Microbial quorum sensing: a tool or a target for antimicrobial therapy?

Inter‐cell communication aided by released chemical signals when cell density reaches a critical concentration has been investigated for over 30 years as quorum sensing. Originally discovered in Gram‐negative bacteria, quorum‐sensing systems have also been studied extensively in Gram‐positive bacteria and dimorphic fungi. Microbial communities communicating via quorum sensing employ various chemical signals to supervise their surrounding environment, alter genetic expression and gain advantage over their competitors. These signals vary from acylhomoserine lactones to small modified or unmodified peptides to complex γ‐butyrolactone molecules. The scope of this review is to give an insight into some of the quorum‐sensing systems now known and to explore their role in microbial physiology and development of pathogenesis. Particular attention will be dedicated to the signalling molecules involved in quorum‐sensing‐mediated processes and the potential shown by some of their natural and synthetic analogues in the treatment of infections triggered by quorum sensing.

Synthetic dyes decolourisation by white-rot fungi: Development of original microtitre plate method and screening

A microtitre plate-based method was developed for a fast screening of numerous fungal strains for their ability to decolourise textile dyes. In 3 days, this method allowed to estimate significant fungal decolourisation capability by measuring the absorbance decrease on up to ten dyes. More than 325 white-rot fungi (WRF) strains belonging to 76 fungal genera were compared with regards to their capability to decolourise five azo and two anthraquinone dyes as well as the dyes mixture. The most recalcitrant dyes belonged to the azo group. Several new species unstudied in the bioremediation field were found to be able to efficiently decolourise all the dyes tested.

(Z)-α,β-dimethoxystilbene

C16H16O2, M(r) = 240.30, orthorhombic, P2(1)2(1)2(1), a = 7.569 (1), b = 9.308 (1), c = 18.502 (2) angstrom, V = 1303.5 (3) angstrom3, Z = 4, D(x) = 1.22 g cm -3, lambda(Cu Kalpha) = 1.5418 angstrom, mu = 6.39 cm-1, F(000) = 512, T = 291 K, R = 0.056 for 2123 observed reflections. The central skeleton of the molecule exhibits a marked deviation from planarity. The dihedral angle between the two O-C(vinyl)-C(aromatic) planes is 11.6 (7)-degrees. The phenyl rings are twisted out of the ethylenic bond plane by 34.2 (6) and 49.8 (6)-degrees, respectively.