Industrial Production Of Penicillin Research Articles

Adaptive Optimal Control of a Penicillin Production Process : Design and Limits of Performance

This paper is concerned with the optimization of industrial penicillin production processes. The process under consideration is characterized by a conflict between yield and productivity as revealed by the analysis of a prototype model of the process. The optimization problem is then to find an operating mode that will achieve the best trade off between yield and productivity. It is shown how this problem can be formulated as a parametric optimization involving parameters that have a clear engineering meaning. This parametric optimization leads to the definition of a control problem which requires a feedback implementation under the form of an adaptive regulator combined with a software sensor.

Penicillium chrysogenum Takes up the Penicillin G Precursor Phenylacetic Acid by Passive Diffusion

Penicillium chrysogenum utilizes phenylacetic acid as a side chain precursor in penicillin G biosynthesis. During industrial production of penicillin G, phenylacetic acid is fed in small amounts to the medium to avoid toxic side effects. Phenylacetic acid is taken up from the medium and intracellularly coupled to 6-aminopenicillanic acid. To enter the fungal cell, phenylacetic acid has to pass the plasma membrane. The process via which phenylacetic acid crosses the plasma membrane was studied in mycelia and liposomes. Uptake of phenylacetic acid by mycelium was nonsaturable, and the initial velocity increased logarithmically with decreasing external pH. Studies with liposomes demonstrated a rapid passive flux of the protonated species through liposomal membranes. These results indicate that phenylacetic acid passes the plasma membrane via passive diffusion of the protonated species. The rate of phenylacetic acid uptake at an external concentration of 3 mM is at least 200-fold higher than the penicillin production rate in the Panlabs P2 strain. In this strain, uptake of phenylacetic acid is not the rate-limiting step in penicillin G biosynthesis.

Degradation of pencillin‐V in fermentation media

In Industrial production of penicillin there is a noticeable loss of the product through degradation reactions. It is shown that the degradation of penicillin-V, both in a complex and in a chemically defined medium, can be separated into a phosphate-catalyzed conversion of penicillin-V to penicilloic-V acid, overlaid by at least one other reaction in which penicillin V is degraded to as yet unknown products. Parameter values for the phosphatecatalyzed degradation are found to be independent of the type of fermentation medium. The rate of formation of other degradation products of penicillin-V is found to be significantly higher in a complex fermentation medium with corn-steep liquor in a chemically defined medium. (c) 1994 John Wiley & Sons, Inc.

Tyrosinase Reaction and Subsequent Chitosan Adsorption for Selective Removal of a Contaminant from a Fermentation Recycle Stream

In the industrial production of penicillin V, the phenoxyacetate precursor is added to the fermentor to direct biosynthesis. When used for producing semisynthetic penicillins, the penicillin V is often hydrolyzed to 6-aminopenicillanic acid with the regeneration of the phenoxyacetate precursor. To reduce raw-material as well as waste-disposal costs, it is desirable to recycle the phenoxyacetate precursor. Unfortunately, the recycle stream is generally contaminated by the p-hydroxylated derivative of this precursor. We examined a two-step approach to eliminate this contaminant. In the first step the tyrosinase enzyme was used to selectively convert the p-hydroxyphenoxyacetate contaminant to a reactive intermediate-presumably its quinone. In the second step, the tyrosinase-generated reactive intermediate was allowed to react with and strongly bind to chitosan. In contrast, the phenoxyacetate precursor was neither oxidized by tyrosinase nor bound to chitosan. When concentrated phenoxyacetate solutions were tested, the combination of tyrosinase and chitosan effectively converted low levels of the p-hydroxyphenoxyacetate contaminant and removed its products from solution, while the concentration of the phenoxyacetate precursor was unaffected.

Improved penicillin amidase production using a genetically engineered mutant of Escherichia coli ATCC 11105

Penicillin G amidase (PGA) is a key enzyme for the industrial production of penicillin G derivatives used in therapeutics. Escherichia coli ATCC 11105 is the more commonly used strain for PGA production. To improve enzyme yield, we constructed various recombinant E. coli HB101 and ATCC 11105 strains. For each strain, PGA production was determined for various concentrations of glucose and phenylacetic and (PAA) in the medium. The E. coli strain, G271, was identified as the best performer (800 U NIPAB/L). This strain was obtained as follows: an E. coli ATCC 11105 mutant (E. coli G133) was first selected based on a low negative effect of glucose on PGA production. This mutant was then transformed with a pBR322 derivative containing the PGA gene. Various experiments were made to try to understand the reason for the high productivity of E. coli G271. The host strain, E. coli G133, was found to be mutated in one (or more) gene(s) whose product(s) act(s) in trans on the PGA gene expression. Its growth is not inhibited by high glucose concentration in the medium. Interestingly, whereas glucose still exerts some negative effect on the PGA production by E. coli G133, PGA production by its transformant (E. coli G271) is stimulated by glucose. The reason for this stimulation is discussed. Transformation of E. coli G133 with a pBR322 derivative containing the Hindlll fragment of the PGA gene, showed that the performance of E. coli G271 depends both upon the host strain properties and the plasmid structure. Study of the production by the less efficient E. coli HB101 derivatives brought some light on the mechanism of regulation of the PGA gene.

INFLUENCE OF THE PROPORTIONS OF KH2PO4, MgSO4, AND NaNO3 IN THE NUTRIENT SOLUTION ON THE PRODUCTION OF PENICILLIN IN SURFACE CULTURES

INTENSIVE STUDY of cultural conditions that favor biosynthesis of penicillin by different strains of the Penicillium notatum-chrysogenum group has been in progress in many laboratories for several years, and it is well known that the strain originally isolated by Flemming in 1929 is not unique in its ability to produce penicillin (Reid, 1933, 1934, 1935; Foster, Woodruff, and McDaniel, 1943; Raper, Alexander, and Coghill, 1944; Raper and Alexander, 1945; Backus, Stauffer and Johnson, 1946). It was pointed out previously that much of the effort on production has been concerned with the organic substrate that may be used by the mold (see extensive work of Raistrick, Clutterbuck, Lovell, Birkinshaw and co-workers published mainly in the Biochemical Journal since 1932), but relatively little detailed attention has been devoted to the inorganic composition of the culture medium. In this connection it should be observed that in an earlier publication (Pratt, 1945) the important paper of Foster, Woodruff and McDaniel (1943) was inadvertently overlooked. More recently Knight and Frazier (1945) called attention to the importance of the inorganic constituents of corn steep liquor in the biosynthesis of penicillin. Earlier work in this laboratory (Pratt, 1945) showed that accumulation of penicillin in surface cultures of Penicillium notatum can be markedly altered by varying the molecular proportions of KH2PO4, MgSO4, and NaNO3 that are added to a corn steep liquor and lactose fermentation medium. Since current industrial production of penicillin is almost exclusively from submerged cultures, and since the strain of Penicillium notatum used in the previous study does not produce well in such cultures, it seemed desirable to determine whether similar results could be obtained with strains of Penicillium that are amenable to present commercial methods. This was the object of the experiments reported below. We believe that the notable differences observed in the response of the several strains of mold to different proportions of salts in the fermentation medium are noteworthy and warrant publication. The use of corn steep liquor in the solutions introduced certain complications, especially for interpretation of the data. Ideally, the experiments should be repeated in detail, using synthetic media of ex-