|
|
|
I
N
D
I
A
N
M
E
D
I
C
I
N
A
L
P
L
A
N
T
S
CONCEPT AND DEFINITIONS OF BIOTECHNOLOGY
‘Biotechnology’, the short form of Biological technology, defies precise definition. The term biotechnology came into general use in the mid 1970s, gradually superseding the more ambiguous ‘bioengineering’, which was variously used, to describe chemical engineering processes using organisms and/or their products, such as fermenter design, control, product recovery and purification. Most authors agree that all processes which utilize biological organisms constitute biotechnology, but what is disputed is which processes are not (Crafts-Lighty, 1983). Definitions of technology too vary from the simple ‘applied science’ to ‘the scientific study of the practical or industrial arts’ (Crafts-Lighty, 1983).
As a consequence of the disagreements, there are at least ten different definitions of biotechnology, each qualified according to the context of use. The following are among the more widely used definitions of biotechnology:
a) "The application of biological organisms, systems or processes to manufacturing and service industry" (HMSO, 1980).
b) "The application of scientific and engineering principles to the processing of materials by biological agents to provide goods and services" (Bull et al., 1982). Agents includes a wide range of biological substances, such as enzymes, as well as whole cells or multicellular organisms. ‘Goods and services’ covers processes such as waste and water treatment.
c) "The integrated use of biochemistry, microbiology and chemical engineering to exploit plant materials and genetic resources for the production of specific products and services" (Mantell, 1989).
Many definitions are rather vague about the nature of the organsim or agents involved in biotechnology. It is argued that systematic farming of plants and animals for food and fuel also falls within these definitions.
Ancient fermented food processes, such as making bread, wine, cheese, curds, idli, dosa, etc., some of which are some 6,000 yr old, and developed long before man had any knowledge of the existence of the micro-organisms involved, also genuinely constitute biotechnology. However, for the sake of convenience, many people exclude these traditional processes from the realm of biotechnology. Conventional agriculture is a well-developed industry in its own right, but in practice, this is not included in biotechnology. Aspects of ‘modern biotechnology’ may have significant effects on ‘traditional biotechnology’. Genetic manipulation to improve brewing and baking yeasts or to introduce new characteristics in crops, biological control of plant pests, and new methods of diagnosing and preventing plant and animal disease, are all now realisable. Whatever the definition, experimental production of new varieties of organisms is one of the important objectives of biotechnology.
In simpler words, biotechnology means the industry-scale use of organisms and/or their products. Biotechnology covers the scientific, technological and commercial aspects almost every area of human welfare from agricultural production to pollution control.
The literature on biotechnology is both vast and diverse, not only because of the diversity of areas it covers but also because it is of utmost current interest. Crafts-Lighty (1983), Walker and Gingold (1993), Chirikjian (1995), Balasubramanian et al., (1996) and Ravishankar and Venkatesh (1997) have provided an excellent coverage of the full range of the subject. Only those aspects that are relevant to medicinal plants are discussed here.
HYBRIDOMA AND MONOCLONAL ANTIBODIES
TRANSGENIC PLANTS
Sexual or somatic hybrids bring together two different complete genomes from the two parents involved. Transgenic plants differ from the hybrids in that they contain one to few genes from one source and the whole genome of another.
New avenues for somatic hybridisation through genetic engineering between not only related taxa but even phylogenetically widely separated taxa, have now opened up. Selective addition of genes from any organism to any other organism or deletion of unfavourable genes from an organism, is achieved. Genetically engineered varieties combining the genes of crop plants and bacteria have been produced. For example, the gene for resistence against lepidopteran insect pests by an endotoxin from Bacillus thuringiensis has been transferred to tobacco, cotton, tomato and potato.
About 100,000 different natural products, formed through complex biosynthetic pathways, occur in plants. The development of transgenic systems for the production of compounds that retain their valuable biological activity (for example, anticancer activity), though a formidable task, is possible.
|
