Bacteriophages and plasmids in streptococcus thermophilus

点击翻译按钮获取中文摘要

The dairy industry is a significant part of our heritage and of our economy. It is the fourth largest sector of the Canadian agri-food economy. In 2007, dairy farming generated receipts of $5.2 billion and sales from dairy processors amounted to $11.6 billion, accounting for 15% of all processing sales in the Canadian food and beverage sector. Over 38,000 Canadians are working on 14,660 dairy farms, and over 22,000 others are employed in 445 dairy plants. This makes the dairy sector the second largest employer in the food industry. More than 450 cheeses are now produced in our country. In 2007, Canadian cheeses were produced at a record level, reaching 403,828 tons, an increase of 4.4% from 2006. Similarly, yogurt production reached an all-time high of 251,672 tons, an increase of 3.3% from 2006. There is no indication that this trend will change soon. However, our dairy industry is facing intense competitions on the national and international markets and must deliver high-quality products. The industrial manufacture of cheese and yogurt requires the inoculation of milk with carefully selected bacterial cells (known as starter culture) in order to control the fermentation and to obtain quality products. The starter culture is a combination of bacteria, of which Streptococcus thermophilus is one of the most important species. Performing starter cultures are critical to obtain high-quality products.