Reversion of L-lysine inhibition of penicillin G biosynthesis by 6-oxopiperidine-2-carboxylic acid in Penicillium chrysogenum PQ-96.

6-Oxopiperidine-2-carboxylic acid (OCA; cyclic alpha-aminoadipic acid) reverses the L-lysine inhibition of penicillin G production by Penicillium chrysogenum PQ-96. The reaction probably depends on the recovery of L-alpha-aminoadipic acid for penicillin G production from OCA.

Problems in taxonomy of streptomycetes.

The bacterial species concept has different bearings. It is used to define "natural" entities with low intra-group variation, but also to serve more subjective purposes. One of problems in Streptomyces taxonomy is that it applies the species concept in both ways, i.e. both to clarify natural relationships and to protect potential (bio)technological inventions. The latter usage has introduced a streptomycetal "technospecies" which may require definition and description in other terms and by other tools than the "nomentaxospecies" which represent a more objective approach to Streptomyces taxonomy. Genetic engineering creates "man-made" microorganisms which are characterized by completely different sets of criteria as compared to their natural counterparts, which may imply needs for different taxonomies for both kinds of organisms. However, since they may occur side by side in one environment both "man-made" and "natural" streptomycetes have to be identified and classified by the same methods and tools, but in such a way which allows their separation.

Biosynthesis of benzylpenicillin by Penicillium chrysogenum and its Golgi apparatus.

The fine structure of high and low-yield mutants of Penicillium chrysogenum producing 10,000 and 100 units of benzylpenicillin was compared. The cells of both mutants showed typical eukaryotic ultrastructure. The Golgi vesicles, present in largest number in cells of high-yield mutant, fuse with the cell membrane and play an important role in the transport of benzylpenicillin from the cytoplasm to the cell environment. Benzylpenicillin was localized in cells of the high-yield mutant by means of enzymatical and immunological methods. The results indicate that benzylpenicillin is stored in the vesicles of the Golgi apparatus. The Golgi vesicles isolated from the protoplasts of high-yield mutant showed activities of enzymes of the pathway of benzylpenicillin biosynthesis i.e., delta-/L-alpha-aminoadipyl/-L-cysteinyl-D-valine synthetase, isopenicillin N synthetase, phenylacetyl: coenzyme A ligase, and acyl-exchange activity. Cell-free biosynthesis of antibiotic by the native Golgi vesicles was investigated in a well-defined reaction mixture. The native Golgi vesicles produced antibiotic in amount corresponding to 320 nmol.mg protein-1.h-1. The activity yield of the calcium alginate immobilized Golgi vesicles was 44%. Moreover, a hypothetical scheme for localization of the enzymes of pathway of benzylpenicillin biosynthesis in the cells of high-yield mutant is presented.

Recombination in antibiotic producing Streptomyces by protoplast fusior.

Revisao das tecnicas de recombinacao genetica, em Streptomyces produtores de antibioticos, por fusao de protoplastos.Analise dos metodos de inducao da fusao, selecao de linhagens para recombinacao, selecao de mutantes, producao e manutencao de protoplastos estaveis, com alta frequencia e regeneracao

The ultrastructure of Penicillium chrysogenum in the course of benzyl-penicillin biosynthesis.

The find structures of high- and low-yield mutants of Penicillium chrysogenum, producing 100 and 10,000 units/ml of penicillin G, were compared. The cells of both mutants demonstrated a typical eukaryotic ultrastructure. In the cytoplasm nuclei, mitochondira, lipid bodies, endoplasmic reticulum, and Golgi vesicles were observed. In the cells of high-yield mutant, during the biosynthesis of penicillin, the number of lipid bodies decreased. It is possible that the lipids are metabolized in the process of biosynthesis of penicillin. In the cytoplasm more multivesicular bodies and small vesicles, about 40 nm in diameter, could be seen. These Golgi vesicles, present in largest number in cells of high-yield mutant, fuse with the cell membrane and play an important role in the transport of penicillin from the cytoplasm to the cell environment. The cell walls of the high-yield mutant become three times thicker during the antibiotic biosynthesis. No comparable changes were observed in the ultrastructure of the low-yield mutant. The cell wall thickness did not increase, the cytoplasm contained few Golgi vesicles only, and the lipid bodies can be seen in all cells.

The site of benzyl penicillin accumulation in Penicillium chrysogenum.

Benzyl penicillin was localized in cells of Penicillium chrysogenum by means of enzymatical and immunological methods, enabling the determination of minute amounts of penicillin. The reactions were performed on ultrathin sections. They allow to determine the antibiotic inside of the cells. The results indicate that benzyl penicillin is present in the vesicles belonging to the Golgi apparatus. Benzyl penicillin is transported from the cytoplasm outside the cell membrane by the Golgi vesicles.