Rumen research that has discovered DNA sequences of entirely new gut bugs in sheep and cattle has reinforced New Zealand’s status as a world leader in microbiology studies.
The NZ-led, global project that discovered and cultured hundreds of microbial strains has earned its 60-plus team of researchers publication of their work in the international Nature Biotechnology magazine.
Dr Sinead Leahy is an AgResearch scientist and joint research leader with the principal investigator and former AgResearch scientist Dr Bill Kelly for the Hungate1000 project.
She said Nature Biotechnology has wider appeal in the scientific community than more specific microbial magazines and its decision to publicise the work highlights the broad significance of the work, beyond rumen science alone.
The project also tips its hat to NZ’s scientific history in this field, being named the Hungate1000 after Bob Hungate who developed pioneering methods for growing anaerobic gut bacteria and who helped train some of NZ’s first rumen microbiologists.
Culturing microbes was a cornerstone of the project, from which their genomes could be sequenced.
The project has created a reference genome catalogue of 501 rumen microbes, well up on the mere 15 known about before the work began.
But part of its success came before that, in getting 60 scientists from 14 research agencies across nine countries together to collaborate on an area relatively little explored in the past.
“It really stemmed from a small workshop seven years ago when we asked a few researchers ‘If you had the choice, where would you like to see research go in this area?’”
The 1000 became an aspirational target, lifted from 100 as the first choice, which itself seemed a long way from the 15 microbes already categorised.
Leahy said the work has yielded its share of surprises, some that challenge conventional wisdom on how life exists.
“For me the biggest surprise was that several of our microbial strains did not have the enolase enzyme, which is a key enzyme needed for catalysing glucose into pyruvate for energy. It is accepted as a basic part of the biochemistry pathway in living organisms, practically all have it.”
That absence in itself is grounds for an entire new area of research and discovery for a committed microbiologist.
A key strength of the research has been that ability to physically culture the microbial strains discovered, rather than the commonly used 16S rRNA gene DNA sequencing techniques used to determine different microbes.
Leahy said DNA sequencing goes only so far, whereas culturing gives scientists a future resource from which a far better understanding of the microbe’s behaviour can be obtained.
In a case of if microbes were like people, researchers can now study how different strains behave in different conditions, whether they perform better in the company of other microbes and what quirks or traits they might contain.
Researchers are also seeing some potential links to human gut microbial populations, with researchers in that field keen to access the catalogue and find what microbes sit most closely to those that inhabit the human gut.
That comes as the human brain-gut axis is being more widely understood.
Leahy said it is only a matter of time until similar connections are made when studying ruminant animals, now some of the microbes are beginning to be better known.
Interest has also been strong in the demonstrated anti-microbial activity exhibited in some of the microbes and how it might be applicable to animal and human health.
More than 60 of the microbe strains have shown to be useful to scientists studying human microbes.
“All the data has been made available as soon as we generated it to the general science community and the cultures are available for research requests.”
While cautious about where application of the research might go, Leahy said there has been obvious and strong interest from scientists working on livestock greenhouse gas emissions and options to develop vaccines and inhibitors based on microbe modification.
“There are literally thousands of strains of microbes in the rumen and they have a very evolved community that works in a balanced way.
“It is likely we will have to learn a lot more about how these communities of microbes work together before you could have a real and long-term impact on modifying them.”
Agricultural Greenhouse Gas Research Centre’s international deputy director Dr Andy Reisinger said the Hungate1000 is central to the work the centre is managing.
“This will help us find ways not only to enhance productivity but also to achieve emissions reductions and deliver solutions to farmers, such as inhibitors and vaccines that don’t affect their bottom lines.”
