Australasian Science: Australia's authority on science since 1938

Bacteria from Baby Poo Used to Make Sausages

By Magdeline Lum

Tasmanian devil facial tumour is evolving, and scientists have created a low-fat sausage using bacteria harvested from infant faeces.

A dirty nappy is not something that awakens the appetite but Spanish scientists could change this. The scientists at Catalonia's Institute of Food and Agricultural Research have created a sausage with less fat using bacteria harvested from the faeces of infants. The bacteria was employed to ferment the meat.

If the part about using bacteria to ferment meat to make a sausage does not sit well with you, it is something that is already in place. The pepperoni on your pizza undergoes bacterial fermentation, and so does another favourite, salami. The tangy flavour is from the activity of bacteria that produce lactic acids. These acids impede the growth of harmful bacteria in the meat.

The bacteria harvested is a microorganism that is added to foods now in the belief that it provides health benefits and falls under the category of probiotic bacteria. Pro­biotics are thought to be beneficial for people with gastrointestinal disorders. The strains collected by the research group were Lactobacillus and Bifidobacterium.

The bacteria were collected from 23 stool samples of infants up to the age of 6 months old. While the source of the bacteria may sound strange, the commercial strain Lactobacillus rhamnosus GG, was first isolated from the intestinal tract of a healthy person in 1983. It has since been added to yoghurt and other dairy products.

Why would anyone look for bacteria in faecal matter? The idea is that material that has passed through the digestive tract of a healthy individual will have bacteria that are good for you.

The bacteria collected from the infant faecal matter were grown and separated on petri dishes before being added to sausage meat for fermentation. The scientists identified six strains of bacteria for the task, and set about making six batches of a traditional Catalan pork sausage called fuet.

Only one strain of bacteria could be successfully grown to levels high enough within the sausage to be considered potentially beneficial to health. Once the scientists had developed their sausages, they were then put to the test by professional tasters.

The tasters could not distinguish between the fuet created by the scientists and commercially available fuet. This is good news because the scientists had not only used bacteria from infant faecal matter but also made a sausage that contained less salt and less fat.

The research was published in Meat Science.

Devil Cancer Evolves

Efforts to control the spread of Tasmanian devil facial tumour disease (DFTD) may have inadvertently triggered an increase in the speed of the evolution of the cancer, according to research published in Evolutionary Applications.

DFTD is one of two known transmissible cancers between Tasmanian devils. It is usually spread when they bite each other during social interaction, and results in the death of an animal within 6 months.

Infected Tasmanian devils have been removed from the Forestier Peninsula in Tasmania in an effort to reduce the spread of the disease. However, Dr Beata Ujvari of the University of Sydney has reported that DFTD seems to have evolved in this region, with recent tumour tissue samples revealing that the number of chromosomes in the tumour has increased. This means that the tumour’s cells divide slower.

Tasmanian devils were removed from the Peninsula as soon as lesions appeared, but this may have left behind devils with slower-growing cancers. As a result, the proportion of the slower-growing cancers in the population increased.

This new discovery may lead to changes in how long a Tasmanian devil need to be kept in quarantine before it is introduced to a group considered to be free of both tumour types.