Bacteriophage-encoded depolymerases: their diversity and biotechnological applications

Bacteriophages (phages), natural enemies of bacteria, can encode enzymes able to degrade polymeric substances. These substances can be found in the bacterial cell surface, such as polysaccharides, or are produced by bacteria when they are living in biofilm communities, the most common bacterial lifestyle. Consequently, phages with depolymerase activity have a facilitated access to the host receptors, by degrading the capsular polysaccharides, and are believed to have a better performance against bacterial biofilms, since the degradation of extracellular polymeric substances by depolymerases might facilitate the access of phages to the cells within different biofilm layers. Since the diversity of phage depolymerases is not yet fully explored, this is the first review gathering information about all the depolymerases encoded by fully sequenced phages. Overall, in this study, 160 putative depolymerases, including sialidases, levanases, xylosidases, dextranases, hyaluronidases, peptidases as well as pectate/pectin lyases, were found in 143 phages (43 Myoviridae, 47 Siphoviridae, 37 Podoviridae, and 16 unclassified) infecting 24 genera of bacteria. We further provide information about the main applications of phage depolymerases, which can comprise areas as diverse as medical, chemical, or food-processing industry.DPP acknowledges the financial support from the Portuguese Foundation for Science and Technology (FCT) through the grant SFRH/BD/76440/2011. SS is an FCT investigator (IF/01413/2013). The authors also thank FCT for the Strategic Project of the UID/BIO/04469/2013 unit, FCT and European Union funds (FEDER/COMPETE) for the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER027462)

Sociability, work and labouring identity in seventeenth-century England

This article explores the relationship between plebeian attitudes about work and plebeian attitudes about sociability. It takes as its start point the term that early modern people themselves used to describe sociability - 'company' - and argues that combining depositional material with an analysis of broadside ballads presents the best way to access such descriptions. What emerges is that the keeping of 'company' was informed by a 'politics of participation' which centred on a set of values that championed both hard labour and excessive drinking. This set of values points at the existence of a certain labouring identity in the period that has implications for our understanding of both the social order and plebeian agency

A Family of Early English Oculists (1600-1751), With a Reappraisal of John Thomas Woolhouse (1664-1733/1734)

Introduction: John Thomas Woolhouse (1666-1733/1734), who practiced in Paris, was part of a family with 5 generations of English oculists. Some historians have derided him as a “charlatan” and have criticized him for adhering to the old notion that a cataract was a membrane anterior to the lens. Methods: We reviewed treatises and digital records related to Woolhouse and his family and the handwritten notes of his 1721 lecture series at the Royal Society of Medicine. Results: We have identified 5 generations of oculists in Woolhouse’s family, by the names of Atwood, Stepkins, Ivy, and Beaumont. Woolhouse taught students from across Europe. He was one of the early proponents in Europe, inspired by Asian medical practices, to perform paracentesis to release aqueous for a new condition called hydrophthalmia. In Woolhouse’s system, some of these cases probably described angle-closure glaucoma. He was the first to attach the name glaucoma to the palpably hard eye in 1707. He may also have been the first to teach that a soft eye was unlikely to recover vision. Credit for these teachings has traditionally gone to one of his students, Johannes Zacharias Platner, in 1745. Some historians have stated that he proposed iridectomy as a theoretical procedure, which was later performed by Cheselden. In fact, Woolhouse described techniques he had performed which today would be called pupilloplasty, synechiolysis, or pupillary membrane lysis. He was also a pioneer in dacryocystectomy for chronic dacryocystitis and in congenital cataract surgery. His writings from 1716 onward repeatedly (and correctly) stressed that most of the patients with visual disorders required depression of the crystalline lens (for what he called glaucoma), as opposed to removal of an anterior membrane (which he called cataract). Conclusions: Woolhouse was a bold ophthalmic innovator and teacher who made major contributions which have lasted to this day. Although he did not admit it, he ultimately adopted much of the evolving understanding of the nature of lens opacities. However, his stubborn refusal to adopt the newer semantics has detracted from a full appreciation of his contributions