Department of Biological Sciences, University of Alberta,
Edmonton, Alberta, Canada, T6G 2E9
Office Number: M532A Bio Sciences
Email address: bill.page@ualberta.ca
Fax number: (780) 492-9234
Phone number: (780) 492-4782

Academic Degrees

BSc: University of British Columbia.

PhD: University of British Columbia Thesis: "Characterization of the Physiological Role of the Microsporum gypseum Alkaline Protease During Macroconidium Germination and Outgrowth" with Dr. John J. Stock, 1973 (key topics medical mycology, botany & microbiology).

Postdoctoral Research: PDF with Harold Sadoff (Michigan State University, 1973-1976) Studies concerned genetic transformation of Azotobacter vinelandii, nitrogen fixation & encystment.

Introductory Microbiology (1st & 2nd year) 1976-present
Coordinator of Industrial Internship Program (1996-2000)
Coordinator of Biol 490, 498 & 499 research project courses (1995-96)
Coordinator of Micrb 495 & 499 research project courses (1991-1994)

Associate Dean (Student Services), Faculty of Science (2000-present)
Chair, AHFMR Internal Allocations Committee (1990-present)
Jury Member, J. Gordon Kaplan Awards for Excellence in Research (1990-present)
Associate Chair (Research) Dept. of Biological Sciences (1994-95)

Member of Canadian Society of Microbiologists
Member of American Society for Microbiology
Section Editor of Canadian Journal of Microbiology (Physiology, Metabolism & Enzymology)
Editorial Board Member: Applied & Environmental Microbiology (1993-2001), BioMetals, & Journal of Applied Microbiology
Reviewer for many journals and NSERC grant reviewer

Current Research Interests

On looking at my research program since 1973, I realize that I have always been treating bacteria very badly and then trying to understand how they respond to these imposed stresses. Azotobacter spp, especially Azotobacter vinelandii, have been the focus of this abuse which has included iron limitation, nitrogen limitation and oxygen toxicity. Iron-limited growth has become a focus, as it induces genetic competence in A. vinelandii, induces iron-uptake systems, promotes capsule formation (alginate), and eventual encystment (differentiation) of the cells. I am particularly interested in the characterization and regulation of iron-uptake systems and iron chelators (siderophores). Student projects involve whatever is required to reach a solution to problems posed, including studies of cell structure, physiology, natural products chemistry, moleculary biology and genetic regulation. We consider these studies of interest to basic science and understanding of how cells respond to and survive stress, and of interest because Azotobacter spp. are common nitrogen-fixing bacteria which improve soil fertility throughout the world.

In the course of these studies, an iron-regulation mutant was discovered which produced large amounts of the polymer poly-b-hydroxybutyrate. Since this material and its copolymers have considerable value as natural biodegradable plastics, this mutant has launched a spin-off project into the control of bacterial production and biodegradation of these polymers (collectively known as polyhydroxyalkanoates). Continuing work in this area concerns the control of metabolic pathways leading to polymer and copolymer production.

A great adventure that we have embarked on this year (2001/02) with collaborators in the USA, UK, Mexico, & Norway is the complete sequencing and annotation of the Azotobacter vinelandii strain UW genome.  There are many things we know about A. vinelandii, after the collective work of 100’s of scientist throughout the world, over the last >90 years.  But we only know the identity of about 200 genes out of a potential 4000 and there are so many questions (see http://www.azotobacter.org/summary.html) that could be answered directly or facilitated by genomic knowledge.  We were very fortunate to have this sequencing project included in the 2^nd genome campaign of the DOE-JGI (Department of Energy Joint Genome Institute, USA) and the scaffold assembly and automated annotation of the genome is progressing under the care of ORNL (Genome and Systems Modeling Group, Oak Ridge National Laboratories, TN).  Go to our website: http://www.azotobacter.org for the latest news in this project.

Graduate Students have been instrumental in the progress of this research. I am always interested to hear from good candidates who want to explore problems in Azotobacter physiology and genetics. The most suitable candidates will have a good background in microbiology and biochemistry, preferably with proven expertise in molecular biology. I have a number of exciting and challenging projects ongoing that need the input of bright and motivated graduate students. (More information on Grad Studies)

Undergraduate Students are welcome to apply for summer positions in my laboratory, as well as for senior level Biol 499 and 498 individual research projects. Many key research contributions have been made by undergraduate students. The best candidates will have an interest in microbiology, biochemistry and molecular biology. All summer students are encouraged to apply for NSERC or AHFMR support, so need GPAs of 8.0 or higher. Biol 499 students should have completed Micrb 311 & 313, Genet 270 and Genet 390 (if possible) and will be specializing in Microbiology, Biotechnology, or Molecular Biology & Genetics. A GPA of 7.0 or higher will prepare you for the work and dedication required to succeed in Biol 498/499.

• Technician, graduate student and undergraduate student authors are highlighted

Iron-Metabolism:

Tindale, A. E., M. Mehrotra, D. Ottem, and W.J. Page. 2000. Dual regulation of catecholate biosynthesis in Azotobacter vinelandii by iron and oxidative stress. Microbiology 146: 1617-1626.

• This paper explains the phenomenon of ‘dual regulation’ of siderophore production in A. vinelandii. A long time ago (Page & Huyer. 1984. J Bacteriol.158: 496-502) we observed that less iron was required to repress azotobactin synthesis than catecholate biosynthesis. In this paper we establish that Fur is the regulator of Fe-mediated repression in A. vinelandii, but catecholates continue to be formed in the presence of Fur::Fe, because there is also an activator of the first gene in the catecholate siderophore biosynthesis (csbC) operon, which promotes transcription under oxidative stress conditions. This continues the theme of catecholates having an additional role to play in oxygen stress management.

• GenBank Entry for csbC gene: AF238500 (Feb 2000) AE. Tindale & WJ Page

Cornish, A. S., and W. J. Page. 2000. The role of molybdate and other transition metals in the accumulation of protochelin by Azotobacter vinelandii. Appl. Environ. Microbiol. 66: 1580-1586.

• This paper provides an explanation for the effect of molybdate on protochelin production. The results suggest that molybdate (and other transition metals) inhibits ferric reductase, thus limiting the turnover of protochelin during Fe uptake, hence decreasing the release of the hydrolysis products aminochelin and azotochelin.

Cornish, A. S., and W. J. Page. 1998. The catecholate siderophores of Azotobacter vinelandii: their affinity for iron and role in oxygen stress management. Microbiology 144: 1747-1754.

• This paper develops the theme of oxygen stress in Fe-limited Azotobacter. Most critically, it shows that the siderophores protochelin and azotochelin will bind Fe and prevent the Fenton reaction, thereby limiting oxidative damage in these cells.

Cornish, A. S., and W. J. Page. 1995. Protochelin, a tricatecholate siderophore produced by Azotobacter vinelandii. BioMetals 8: 332-338.

• In this basic research paper we describe how the known mono- and di-catecholate siderophores of Azotobacter vinelandii are degradation products of the true siderophore protochelin, a tricatecholate. This siderophore has escaped detection in over 28 years of Azotobacter research, because the siderophore does not accumulate in wild type cultures. However, we found that the siderophore persists in the culture fluid if it is complexed with molybdate.

Matzanke, B. F., R. Bohnke, C. Hennard, M. Abdallah, W. J. Page, E. Bill, V. Scunemann, and A. X. Trautwein. 1996. Diversity of iron storage in bacteria - a Mossbauer spectroscopic comparison of E. coli and Azotobacter vinelandii. International Conference on the Applications of the Mossbauer Effect (ICAME-95). Italian Physical Society, Conference Proceedings 50: 15-818.

• This paper shows that Fe-limited strain UWD (the strain we use for bioplastic production, below) donates Fe to ferritin, which accumulates in the cell. It is interesting that UWD was first selected because the cells become Fe-limited very easily and overproduce azotobactin. However, the cells contain considerable amounts of Fe and therefore are not starving for Fe. This contradiction is explained here, since the Fe in these cells is sequestered in ferritin and presumed not to be readily available to cell metabolism.

Bernardini, J. J., C. Linget-Morice, F. Hoh, S. K. Collinson, P. Kyslík, W. J. Page, A. Dell, and M. A. Abdallah. 1996. Bacterial siderophores: structure ellucidation and ¹H, ¹³C, ¹⁵N two dimensional NMR assignments of azoverdine and related siderophores synthesized by Azomonas macrocyto genes ATCC 12334. BioMetals 9: 107-120.

• This paper continues a long term collaboration with Mohammed Abdallah in Strasbourg. Here we describe the structure of azoverdin, a subclass of the peptide siderophores which include azotobactin (from A. vinelandii) and pyoverdins (from Pseudomonas spp.). This work was initiated by an exchange visit by my graduate student Karen Collinson in 1989.

Polyhydroxyalkanoates:

Page, W. J., A. Tindale, M. Chandra, and E. Kwon.  2001. Alginate formation in Azotobacter vinelandii UWD during stationary phase and the turnover of poly-b-hydroxybutyrate.  Microbiology 147: 483-490.

• One of the great advantages of using strain UWD for PHB production is that it is unable to form alginate capsules & slime.  Here we show that there is an IS element inserted in algU, which codes for the sigma factor that promotes transcription of the alginate biosynthesis operon.  But in stationary phase, strain UWD forms significant amounts of alginate as PHB is being turned over.  During this time, the first gene in alginate biosynthesis (algD) is transcribed from a secondary promoter recognized by the housekeeping (RpoD) and the stationary phase (RpoS) sigmafactors. 

• GenBank Entry for insertion element (ISAzvi1): #AF322366 (Nov 2000) D. Meakins, AE Tindale, & WJ Page

Finkelstein, R. A., M. Boesman-Finkelstein, D. K. Sengupta, W. J. Page, C. M. Stanley, and T. E. Phillips. 1997. Colonial opacity variations among the choleragenic vibrios. Microbiol. (UK) 143: 23-34.

• In this collaborative venture initiated by Dick Finkelstein, we describe that increased colony opacity is directly proportional to increased polyhydroxyalkanoate (PHB) content in the cells, as well as other factors. Cells with increased PHB content may survive better in the environment and may contribute to the persistence of choleragenic vibios in water sources.

Page, W. J., N. Bhanthumnavin, J. Manchak, and M. Ruman. 1997. Production of poly(ß-hydroxybutyrate-ß-hydroxyvalerate) copolymer from sugars by Azotobacter salinestris. Appl. Microbiol. Biotechnol. 48: 88-93.

• Here we describe the formation of polyhydroxyalkanoate copolymers from sugar alone, without the need for ß-oxidation induction. While this mechanism used is not new, this is the first publication to show that it may be possible to control the percent copolymer in the polymer, to produce bioplastics with predictable properties. Such control is lacking in other systems.

Page, W. J., and C. J. Tenove. 1996. Quantitation of poly-ß-hydroxybutyrate by fluorescence of bacteria and granules stained with Nile blue A. Biotechnol. Techniques 10: 215-220.

Budwill, K., P. M. Fedorak, and W. J. Page. 1996. Anaerobic microbial degradation of poly(3-hydroxyalkanoates) with various terminal electron acceptors. J. Environ. Polymer Degrad. 4: 91-102.

• This paper continues our description and analysis of anaerobic degradation of polyhydroxyalkanoates. We were the first to prove that these polymers could be degraded anaerobically by a methanogenic bacterial consortium (publication in 1992), which has implications for bioplastic disposal.

Page, W. J., and J. Manchak. 1995. The role of ß-oxidation of short-chain alkanoates in polyhydroxyalkanoate copolymer synthesis in Azotobacter vinelandii UWD. Can. J. Microbiol. 41 (Suppl. 1): 106-114.

• In this basic research paper we describe the physiologic routes leading to copolymer formation. This is the first description and analysis of a ß-oxidation complex in a bacterium that is induced by short-chain alkanoates and where substrates are not channelled through the complex. Substrates can be withdrawn after partial ß-oxidation and directed into polyhydroxyalkanoate copolymer synthesis. Regulation of fatty acid degradation (ß-oxidation) and biosynthesis (polymer formation) are in conflict, so polymer yield is negatively affected by the need to form copolymers by ß-oxidation. This accounts for a long standing observation in this field.

Manchak, J., and W. J. Page. 1994. Control of polyhydroxyalkanoate synthesis in Azotobacter vinelandii UWD. Microbiol. (UK) 140: 953-963.

Page, W. J., and A. Cornish. 1993. Growth of Azotobacter vinelandii UWD in fish peptone medium and simplified extraction of poly-ß-hydroxybutyrate. Appl. Environ. Microbiol. 59: 4236-4244.

• Here we describe the effects of fish peptone on causing pleomorphism in A. vinelandii and how the creation of cells with such a weakened cell wall could be exploited in a simple, inexpensive procedure to extract the polymer from the cells using aqueous ammonia. Ammonia wastes can then be recycled as a nutrient in the polymer production process.

Page, W.J., J. Manchak and B. Rudy. 1992. Formation of poly(hydroxybutyrate-co-hydroxyvalerate by Azotobacter vinelandii strain UWD. Appl. Environ. Microbiol. 58: 2866-2873.

• This key publication describes the production of copolymers, a necessary step towards the formation of commercially useful plastic