ABSTRACT
For practical reasons it is important to distinguish between the traditional or early methods of biotechnology and the modern approaches and techniques of this field. This is particularly relevant in the case of dairy science and technology because regulations, riskbenefit analyses, and perceptions of processes involving the use of genetic engineering differ from those that do not involve recombinant technology. Animal husbandry and food technology have provided solutions to the challenges and problems encountered during the production of milk and milk-derived products; the tools and methods of these fields constitute “early biotechnology.” This is in contrast to modern biotechnology, which is constituted by methods based on recombinant deoxyribonucleic acid (DNA) techniques (1) and novel approaches for the purification of materials, selection of microbial strains, fermentation and manufacturing processes, and analysis of foods. The specialist who implants embryos while aiming to expand a desirable characteristic in a herd of dairy cows and the cheese maker who inoculates curd with a naturally occurring starter culture are indeed using the tools and methods of traditional or early biotechnology. On the other hand, the molecular biologist who attempts to insert a gene fragment at a specific site of the bovine genome with the purpose of producing dairy products containing human milk proteins is clearly using modern methodologies. Likewise, the task of genetically modifying a microbial strain to speed up the maturation process in a cheese requires modern techniques. This review focuses on processes and technologies that utilize genetic engineering and that, in most cases, produce genetically modified organisms (GMOs) or their derivatives. The present account constitutes a brief overview of modern biotechnology as it applies to the production and modification of dairy products. Its purpose is to provide a catalogue of techniques involving the use of recombinant nucleic acids in the context of animal productivity and milk and milkderived product remodeling or improvement. Ancillary aspects are also discussed. The reader is referred to previously published reviews that address general aspects of modern biotechnology (2-4).
