Professor ROBERT WALLACE

Biography

Prof John Wallace obtained a 1^st class Honours B.Sc. in Biochemistry from the University of Glasgow in 1972.  In 1973 and 1974, he worked at Distillers Company Ltd research labs, Menstrie.  Shortly after completing his Ph.D. at the University of Glasgow in 1975 ‘Maintenance energy and molar growth yields of Escherichia coli’, he joined the Microbiology Department of the Rowett Research institute, at that time headed by P.N. Hobson, with Sir Kenneth Blaxter as Institute Director.  He has remained at the Rowett since 1976, developing interests in rumen and intestinal microbiology and ruminant nutrition.  Following the merger of the Rowett with the University of Aberdeen in 2008, he was appointed to a Personal Chair at the University, and upon his retirement in 2016 was awarded emeritus status.    At various times during his career, he has undertaken research sojourns in Australia, Japan and Ethiopia, and has served on the Editorial Boards of Microbiology, British Journal of Nutrition (Deputy Editor-in-Chief), FEMS Microbiology Letters, Animal Feed Science and Technology and Applied and Environmental Microbiology.  He has served on the research committees of BBSRC, the FEEDAP (feed additives) panel of the European Food Safety Authority and curr ently chairs the Feed and Feed Additives group at the UK's Food Standards Agency.  Career highlights include being invited to speak at the Pasteur Institute, Papeete, Tahiti, in ‘The Year of Louis Pasteur’ Symposium’, Microbes, Environment , Biotechnology, 8-12 May 1995, and being recognised via the DSM Nutrition Innovation Award in 2007 'in recognition of his pioneering research in animal nutrition.'

External Memberships

Member of the FEEDAP panel of the European Food Safety Authority, 2012-2018, and external adviser (2018 - present).

Member of Editorial Boards, Applied and Environmental Microbiology, Animal Feed Science and Technology.

Member of the International Science Foundation assessment committee.

Member of the Stakeholder Advisory Group, 'HoloRuminant', Horizon 2020

Project advisor, 'Influence of tannins on fatty acid biohydrogenation' Faculdade de Medicina Veterinária (FMV/UTL), Lisboa;Instituto de Ciências e Tecnologias Agrárias e Agro-Alimentares - Porto (ICETA-Porto/UP)

Project reviewer, Australian National Livestock Methane Program, Livestock Production Innovation, Meat & Livestock Australia.

Assessor and rapporteur, COST Association, European Commission.

Prizes and Awards

DSM Nutrition Innovation Award in 2007 'in recognition of his pioneering research in animal nutrition.'

1998, 2003, 2005, 2007 - BBSRC Exceptional Performance Award

2007, 2008 - City of Aberdeen Ambassador awards

2008 - BBSRC Outstanding Performance Award

Plos Genetics Research Prize 2017.

Research Overview

Research interests encompass microbial physiology, biochemistry and ecology that govern gut function, particularly in ruminants.  Aspects of gut function of particular interest include: protein metabolism – which leads to inefficient protein retention by ruminants and the formation of toxic products in the human intestine;  fatty acid biohydrogenation – which causes ruminant products to be low in most health-promoting PUFA; methane formation – a significant contributor to climate change; and ruminal acidosis – a major welfare issue for ruminants.  Coupled with these issues are means by which manipulation of ruminal fermentation can be achieved, such as probiotics, phytochemicals and antimicrobials.

Current Research

Methane is a greenhouse gas (GHG), 28 times as potent as carbon dioxide.  Ruminants are major methane emitters, contributing 3-4% of global GHG emissions.  The methane is derived from microbial fermentation in the rumen, being produced by microbes known as archaea.  In collaboration with Bob Mayes of the James Hutton Institute and Rainer Roehe and John Rooke of the Scotland’s Rural College (SRUC), Edinburgh, we have established that the abundance of the archaea in ruminal digesta can be used to predict methane emissions of beef cattle, even using post-mortem samples.  Furthermore, the Framework 7 project which I coordinated, ‘RuminOmics’ involving 12 European and Israeli partners, made the groundbreaking discovery that methane emissions in cattle vary according to the microbiome that is present in the rumen and that the microbiome itself is regulated by the host animal's genetics.  This enables the intriguing capability that  cattle may be bred according to their rumen microbiome, leading to progeny that persistently produce lower methane emissions.

Hydrogen is also utilized by fatty acid biohydrogenation in the rumen, which leads to a high proportion of health-threatening saturated fatty acids in foods derived from ruminants and to the formation, followed by the destruction, of health-promoting conjugated linoleic acids (CLA), and to the destruction of n-3, health-promoting fatty acids. The primary aim of this part of our research has been to improve the fatty acid composition of ruminant milk and meat for human health. In order to achieve this aim, the microorganisms responsible for fatty acid transformations in the rumen were identified, the fluxes through pathways of biohydrogenation and desaturation measured, the population sizes of the most significant microbial species evaluated, and ways of altering these fluxes and populations were investigated.  Currently, the research is being continued via the National Buffalo Research Institute, Nanning, China.

Sub-acute ruminal acidosis (SARA) is a disorder that can afflict all ruminant species, but one that is particularly prevalent in intensively produced dairy and beef cattle.  It is thought to result from dysfunction of ruminal microbial ecology.  SARA might be regarded as mainly an unseen, and most certainly under-researched, disorder, because its symptoms are those of ill-thrift rather than illness.  The pathology is only found clearly upon post mortem inspection.  However, next to the ill-thrift, SARA is associated with reduced fibre degradation, reduced feed intake, laminitis and diarrhoea and thereby also increased involuntary culling. Its economic impact is therefore hard to determine exactly.  The loss to the UK economy could easily exceed £200M p.a.  The welfare justification for investigating SARA is also compelling, as SARA-related illnesses are painful and detrimental to health, particularly laminitis.

The Scottish SARA Consortium, funded by BBSRC, to investigated:

1. If on-farm management practices can be identified that predispose beef and dairy cattle to SARA.
2. If remote motion sensing devices mounted around the animal’s neck can give early warning of SARA.
3. What is the precise pathology of black patches on the rumen wall?
4. If soluble LPS in SARA-susceptible cattle differs from soluble LPS in SARA-resistant cattle.
5. The relative importance of the rumen and the hindgut in SARA.
6. The precise pathotypes of E. coli present in SARA-susceptible cattle.
7. If probiotic bacteria can be isolated from individual SARA-resistant cattle.

Past Research

Protein nutrition of ruminants is compromised by the intervention of ruminal microorganisms, which break down dietary protein, via peptides and amino acids, to ammonia.  Mechanisms and microorganisms at each stage of the process were identified, with the highlight being the discovery of a two-step breakdown mechanism for peptides.  Major efforts to control protein and other rumen functions using plants and p[lant extracts resulted in the discovery of >20 useful plants which, if incorporated into the ruminant diet, would modify rumen microbial activity to the benefit of animal nutrition and health.  Essential oils proved particularly beneficial, and the microbiological explanation of their effects led to commercial exploitation.

Human gut microbiology is much simpler than that of ruminants, but shares some similarities.  The unexpected biphasic breakdown of peptides, for example, occurs in the human intestine as well, with implications for human health.

Collaborations

Kevin Shingfield, Aberystwyth University (fatty acid metabolism, methane); Veerle Fievez, University of Gent (fatty acid metabolism); Rui Bessa, University of Lisbon (fatty acid metabolism); Margarida Maia, University of Porto (fatty acid metabolism); Mick Watson, University of Edinburgh (metagenomics); Nick Jonsson, University of Glasgow (SARA); Ivan Andonovic, Strathclyde University (SARA); Pekka Huhtanen, Sveriges lantbruksuniversitet, Umeå (methane); Phil Garnsworthy, Nottingham University (methane); Paolo Bani, Catholic University, Piacenza (methane); Sinead Waters, Teagasc, Dublin (methane);  Tim McAllister, Lethbridge, Canada; Pierre Taberlet, Grenoble University, France; Chris McSweeney, CSIRO, Brisbane.

Funding and Grants

2011       TSB Genomics Competition, with Ingenza Ltd. £513,000 

2011       EC FP7, FOOD-SEG partner, €23,219 euros (of total 999,915 euros) 

2012    Studentship, Commonwealth Scholarship Commission 

2012       Framework 7 project RuminOmics, coordinator, €7.7M, 2012-2015 

2012     BBSRC Industrial Partnership Award: Sub-acute ruminal acidosis (SARA). Consortium leader.  £1.2M, 2012-2015 

2012       Technology Strategy Board SPARK, methane  £5k

2012       EBLEX (with SRUC) SafeBeef. £280k 

2013       BBSRC Studentship with SRUC, methane

Teaching Responsibilities

No undergraduate teaching responsibilities