Transfer of Entire Biosynthetic Pathway, Streptomycetes, Penicillin, Neurospora, Antibiotic, Penicillin, Aspergillus niger

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	Transfer of Entire Biosynthetic Pathway - The transfer of an entire biosynthetic pathway is facilitated by the clustering of genes involved. Following are some examples: (i) Genes for biosynthesis of antibiotics actinorhodin and erythromycin A were transferred to Streptomyces lividans, separately from S. coelicolor and S. erythreus respectively; similarly genes for the biosynthesis of the antibiotic" penicillin V were transferred from Penicillium chrysogenum to Neurospora crassa and Aspergillus niger. In each case the new host synthesized the new product using genes for entire biosynthetic pathway transferred from original species.
(ii) Genes for biosynthesis of biodegradable polyester, polyhydroxybutyrate (PHB) were transferred from Alcaligenes eutrophus to E. - coli. This recombinant E. coli was shown to produce PHB concentrations approaching 50% of the dry cell weight, when nitrogen source is depleted. (iii) It was possible to construct bacterial strains (having as many as five degradation pathways derived from three organisms); which could simultaneously cause degradation of mixed substrates involving biochemical and metabolic complexities. (iv)Genes for tryptophan and threonine biosynthetic pathways could be transferred to E. coli, which could be used as amino acid producers.