Koon Teh
Doctor of Philosophy, (Food Technology)
Study Completed: 2013
College of Health
Citation
Thesis Title
Enzymes produced by bacteria within biofilms of dairy origin and their effect on dairy products
Read article at Massey Research Online: 
Prior to Mr Teh’s study, there were some unexplained reports of dairy product spoilage. Although all quality indicators suggested that products were of the best quality following manufacture, unusual flavours were sometimes reported. Mr Teh showed that bacteria from the internal surface of milk tankers (biofilms) could produce enzymes that remain active after dairy manufacture. These biofilms were found to produce up to 10 times more enzymes than these bacteria normally produce, which was associated with the biofilm form of growth. The link between the quality of dairy products and enzymes produced by bacteria within biofilms was demonstrated. Furthermore, heat-stable enzymes produced by bacteria within biofilms in an in vitro model of a milk tanker, were shown to reduce the quality of UHT dairy products during prolonged storages. His results suggest that the transportation of milk needs to be controlled to prevent spoilage of dairy products.
Supervisors
Professor Steve Flint
Dr Denise Lindsay
Dr Paul Andrewes
Associate Professor Jon Palmer
Associate Professor Phil Bremer