The rumen of ruminants contains a plethora of microorganisms, collectively known as the rumen microbiome and is involved in the breaking down of organic matter to convert it for use in the body.

This process does not, however, translate the quality of the plant matter into quality meat in respect of the levels of polyunsaturated fatty acids and saturated fatty acids. This is due to the double bonds present in PUFA being toxic to bacteria.


Some of the differences between PUFA’s and SFA’s. Image from Peddia.


Due to this, the microbiome converts 92% to 96% of PUFA’s into SFA through the process of lipolysis and biohydrogenation. Dr Sharon Huws, a senior lecturer at Aberystwyth university, looked at the believed major contributor to this process, butyrivibrio, and found that it probably wasn’t as large a culprit as was originally thought.



Following this, research was done looking at which bacteria were particularly responsible, by looking at populations in microbiomes of high and low biohydrogenation rates, as by preventing this process the quality of the product produced could be increased.

Unfortunately, no specific culprits were found, so research took a new route to look at the enzymes involved instead. If researchers can find and block the enzymes involved in lipolysis, then the quality of the product can be increased.



Using macroalgae for biofuel has some benefits over plant matter, one being that it can produce a higher biomass per unit area. However, the main issue so far with the production of fuel from algae has been the breakdown of the complicated polysaccharides, including ulvan.


The North Ronaldsay sheep is found mainly on its native island in the northernmost Orkneys and feeds primarily on macroalgae. Image from RBST.

A potential solution to this problem was found in a rare breed of sheep, the North Ronaldsay sheep. After collecting faecal samples, culturing 250 new bacterial isolates, creating a bioassay of 83 potential ulvan lyases, genome sequencing and fitting to a phylogenetic tree, they found three ulvan lyases different to those already in the literature.

In the future, these may be used to harvest biofuel from macroalgae.




After gaining inspiration whilst working with students, Dr Huws received funding for looking into possible novel antimicrobials in the rumen biome, by looking at the fosmid library created during the search for ulvan lyases, containing over 30,000 clones, as well as those already found in the literature.

From the first experiments they found 200 novel antimicrobial peptides, however, three, in particular, had promising MIC values against resistant bacterial strains.

In resistance trails, no increase in resistance was found over 25days in Ecoli and various MRSA strains, and no major evidence of cytotoxicity was found in mice trials.



After topically testing the three peptides on wounds inoculated with MRSA, it was found only one of the three had potential as an antimicrobial, and at a 10% level, it had an effect comparable to mupirocin against the MRSA.


My opinions and how this will shape my future

This is a seminar that has opened my eyes to looking for solutions in places you wouldn’t expect them. Although I do not have a great interest in microbiomes, this certainly highlighted their importance in the animal kingdom. Even the smallest of organisms can have a huge impact on advances in science. This has, rather unexpectedly, encouraged me to consider the soil types in my masters’ thesis on the biogeography of the gorillas, due to the fact that a small difference here could have a huge impact on higher up the food chain.