Preface

This book on cellulose, the second in a series of three, deals with the many applications of cellulose, both established ones and those that are emerging. It shows the richness in the way cellulose can be modified to serve a large variety of functions, varying from medical, pharmaceutical and bioelectronics applications. We hope that with these examples the imagination of the reader is stimulated and may him- or herself attempt to find new, fascinating applications of cellulose.

> **Theo van de Ven** Department of Chemistry at McGill University, Canada

**Louis Godbout**  Academic Associate at McGill University Pulp and Paper Research Centre, Canada

**Chapter 1** 

© 2013 Spiers et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© 2013 Spiers et al., licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

**Cellulose Expression in** 

*Pseudomonas fluorescens* **SBW25** 

Andrew J. Spiers, Yusuf Y. Deeni, Ayorinde O. Folorunso,

Anna Koza, Olena Moshynets and Kamil Zawadzki

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/53736

**1. Introduction** 

**and Other Environmental Pseudomonads** 

Bacterial cellulose was first isolated from the air-liquid (A-L) interface biofilm produced by *Bacterium xylinum* in 1886 [1], an acetic acid bacterium strain which would probably now be recognised as *Gluconacetobacter xylinus* (formerly *Acetobacter xylinum*) or a related species. Over the following century, more acetic acid bacteria and additional *Proteobacter* were found to produce cellulose (reviewed in [2-3]). Cellulose-producing bacteria include a mixture of gut commensals, plant and animal pathogens (these are listed in Table 1), and all share soil as a common secondary habitat. It is likely that cellulose provides protection against physical disturbance, predation or other environmental stresses common to these diverse environments. The biochemistry of bacterial cellulose expression has been studied extensively for *Gluconacetobacter,* and this understanding has been used as a model for enteric bacteria and pseudomonads [4-5] (for a range of bacterial cellulose reviews, see [2-3, 6-9]). Experimental reports of bacteria expressing cellulose are increasing, as well as the annotation of putative cellulose synthase-like operons in bacterial whole-genome sequences, suggesting that an

Our interest in bacterial cellulose began with the experimental evolution of the soil and plant-associated pseudomonad, *Pseudomonas fluorescens* SBW25 [10-12]. This resulted in a novel biofilm–forming adaptive mutant known as the Wrinkly Spreader (WS) and shown in Figure 1. Subsequent investigation of the WS phenotype identified partially-acetylated cellulose as the main matrix component of the biofilm. The pseudomonads are a highly diverse genus (see recent reviews by [13-14]), and biofilm-formation and celluloseexpression are now known to be common amongst the water, soil, plant-associated and

increasingly wider range of bacteria may be capable of producing cellulose.

**Chapter 1** 
