Scoby could protect waterways
Researchers have found the culture used to ferment the popular health drink kombucha can also drastically reduce levels of E coli in dairy effluent.
AgResearch scientist Seth Laurenson said his team of researchers tapped $30,000 in funding for the project from the Ministry for Business, Innovation and Employment as part of the Strategic Scientific Investment Fund and AgResearch’s Curiosity Fund, a blue-sky research fund for scientists to study out of the box ideas.
They discovered that scoby (symbiotic culture of bacteria and yeast), the slimy material used to make kombucha from tea, could also grow in effluent.
Originally, the researchers had been exploring whether scoby could be used as a bioplastic for use as balage wrap or as tree protectors around wetlands along rivers and streams.
‘‘It worked OK, but there were a few things to be addressed.’’
In the course of their research the team began to wonder if scoby could be used to reduce E coli in effluent since it could reduce the pH of a brew so that it was quite acidic. E coli does not do well in acidic environments, Laurenson said.
The bacteria can pose a significant risk to people and livestock if consumed and is an indicator that other faecal microbes such as campylobacter may be present and is easy to measure.
Scoby produces acetic acid and according to scientific literature, some alcohol, giving it good antimicrobial properties, one of the reasons people have viewed kombucha as a health product, he said.
Kombucha is made with tea and sugar, sources of nitrogen and carbon respectively.
‘‘What we have in effluent ponds is a lot of both of those things. Our trial was in a lab under controlled conditions but it does prove to us that we can grow the scoby in those types of broths. It was a proof of concept study over two or three months.’’
Now Laurenson wants to find out if it will work on a dairy farm’s effluent pond, and also test whether or not it would be practical for farmers to use.
Effluent is normally applied to land, but can pose an environmental risk if conditions are not favourable. E coli can leach into drainage systems and then into waterways, posing a risk to people who drink it or swim in it, he said.
The researchers hope that using their method, a lower E coli load will flow into drains and waterways. ‘‘The most logical step is to set up a pilot study on a dairy farm and remove a portion of the effluent and try to treat that. We need to see if it will reduce E coli on the farm.’’