Scale-down of Cephalosporium acremonium Cultivations for High Throughput Screening of High-yield Cephalosporin C Strains (original) (raw)
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Cephalosporins were developed to overcome the allergic problems associated with penicillins (Lowe, 2001), also they have broad antibacterial spectrum, and in addition was highly resistant to β-lactamase . Cephalosporins are made from cephalosporin C, the fermentation product of Cephalosporium acremonium, which after extraction and purification, is hydrolyzed, either enzymatically or chemically, to the active nucleus, 7-aminocephalosporanic acid (7-ACA), which serves as substrate for the chemical synthesis of injectable and oral semi-synthetic cephalosporins .
Pakistan Journal of Zoology
In the present study, cephalosporin was produced through submerged fermentation in 250 ml Erlenmeyer flask. About one hundred fungal strains were isolated and screened for maximum productivity of the antibiotic cephalosporin. Among these, the strain IIB-10 identified as Acremonium chrysogenum was found to have maximum production of cephalosporin when cultivated on M-4 medium containing (%, w/v): Corn meal, 2; Baker's flour, 1.5; Ammonium sulphate, 0.1; Calcium carbonate, 0.3 and Methyl oleate, 1.6. The nutritional study for maximum cephalosporin productivity was undertaken. Sucrose as a sole carbon source at 2.5% level, peptone at a concentration of 1.5% as an organic nitrogen source and Ammonium sulphate at a concentration of 0.4% as an inorganic nitrogen source supported maximum production of cephalosporin i.e., 721.89 mg/l.
Biotechnology and Bioengineering, 2004
The industrial production of antibiotics with filamentous fungi is usually carried out in conventional aerated and agitated tank fermentors. Highly viscous non-Newtonian broths are produced and a compromise must be found between convenient shear stress and adequate oxygen transfer. In this work, cephalosporin C production by bioparticles of immobilized cells of Cephalosporium acremonium ATCC 48272 was studied in a repeated batch tower bioreactor as an alternative to the conventional process. Also, gas-liquid oxygen transfer volumetric coefficients, k L a, were determined at various air flow-rates and alumina contents in the bioparticle. The bioparticles were composed of calcium alginate (2.0% w/w), alumina (<44 micra), cells, and water. A model describing the cell growth, cephalosporin C production, oxygen, glucose, and sucrose consumption was proposed. To describe the radial variation of oxygen concentration within the pellet, the reaction-diffusion model forecasting a dead core bioparticle was adopted. The k L a measurements with gel beads prepared with 0.0, 1.0, 1.5, and 2.0% alumina showed that a higher k L a value is attained with 1.5 and 2.0%. An expression relating this coefficient to particle density, liquid density, and air velocity was obtained and further utilized in the simulation of the proposed model. Batch, followed by repeated batch experiments, were accomplished by draining the spent medium, washing with saline solution, and pouring fresh medium into the bioreactor. Results showed that glucose is consumed very quickly, within 24 h, followed by sucrose consumption and cephalosporin C production. Higher productivities were attained during the second batch, as cell concentration was already high, resulting in rapid glucose consumption and an early derepression of cephalosporin C synthesizing enzymes. The model incorporated this improvement predicting higher cephalosporin C productivity. B 2004 Wiley Periodicals, Inc.
Artificial Cells, Blood Substitutes, and Biotechnology, 2010
7-aminocephalosporanic acid (7-ACA) is the key intermediate for the synthesis of semisynthetic cephalosporin antibiotics and enzyme cephalosporin-C acylase (CPC acylase) plays an important role in the conversion of cephalosporin-C to 7-ACA. With an aim to increase the yield of 7-ACA production by Micrococcus luteus , a stepwise strategy, statistical medium was applied for optimizing the medium composition for the production of CPC acylase. Purifi ed enzyme was found to be of 80 kDa. The optimum pH and temperature for the production of 7-ACA were 7.6 and 340C, respectively. The Km and Vmax were estimated to be 9.43 mg/mL and 7.65 U/mL, respectively.
Genetic engineering approach to reduce undesirable by-products in cephalosporin C fermentation
Journal of Industrial Microbiology and Biotechnology, 1998
Deacetoxycephalosporin C (DAOC) is produced by Acremonium chrysogenum as an intermediate compound in the cephalosporin C biosynthetic pathway, and is present in small quantities in cephalosporin C fermentation broth. This compound forms an undesirable impurity, 7-aminodeacetoxycephalosporanic acid (7-ADCA), when the cephalosporin C is converted chemically or enzymatically to 7-aminocephalosporanic acid (7-ACA). In the cephalosporin C biosynthetic pathway of A. chrysogenum, the bifunctional expandase/hydroxylase enzyme catalyzes the conversion of penicillin N to DAOC and subsequently deacetylcephalosporin C (DAC). By genetically engineering strains for increased copy number of the expandase/hydroxylase gene, we were able to reduce the level of DAOC present in the fermentation broth to 50% of the control. CHEF gel electrophoresis and Southern analysis of DNA from two of the transformants revealed that one copy of the transforming plasmid had integrated into chromosome VIII (ie a heterologous site from the host expandase/hydroxylase gene situated on chromosome II). Northern analysis indicated that the amount of transcribed expandase/hydroxylase mRNA in one of the transformants is increased approximately twofold over that in the untransformed host.
Process strategies for cephalosporin C fermentation
JOURNAL OF SCIENTIFIC …, 2006
Cephalosporin C (CPC), a β-lactam antibiotic, is starting molecule for industrial production of semi synthetic cephalosporins. CPC fermentation has been carried out in Air Lift Reactor (indigenously made up of borosilicate glass) in different fermentation modes ie, batch and fed batch ...
A comparative evaluation of Cephalosporin C production using various immobilization modes
The Journal of General and Applied Microbiology, 1998
Cephalosporin C, a β lactam antibiotic, is produced from fungus, Cephalosporium acremonium. The production of Cephalosporin C (CPC) is a non-growth associated process. The growth phase precedes the antibiotic production phase of fungal physiology. Sufficient cell growth is required to promote adequate antibiotic synthesis. The unfortunate feature of the fungus growth is the high viscosity of the culture growth, which results in decreased oxygen transfer. Various immobilization modes viz pellets, siran carrier and silk sachets were used as alternate strategies to improve antibiotic productivity. Also, the volumetric oxygen transfer coefficients were improved for pellets, siran carrier and silk sachets. An airlift reactor (ALR) provides improved oxygen transfer as compared to the conventional stirred-tank reactor although no mechanical agitation is provided. Materials and Methods Microorganism. Cephalosporin C production studies were performed using organism Cephalosporium acremonium NCIM 1069, obtained from NCL Pune, India. The culture was maintained on potato dextrose agar medium at 28°C and pH 7.4. Growth and production medium. Batch fermentation was carried out at 28°C for 72 h on a synthetic media (Kennel and Demain, 1978). The seed culture media contained in 1.0 l, sucrose (30 g), potassium dihydrogen phosphate (1.5 g), magnesium sulfate heptahydrate (0.3 g), and a trace metal solution, which was sterilized separately. The production medium contained in 1.0 l, sucrose (30 g), ammonium sulfate (7.5 g), oleic acid (1.5 g), dipotassium hydrogen phosphate (15.3 g), DL methionine (3.0 g) and anhydrous sodium sulfate anhydrous or dehydrous (1.7 g). The pH was maintained at 7.4. Siran supported growth. Siran beads, obtained from Bioengineering AG, Switzerland, were shifted by sieve fractionation, and particle sizes ranging from 600-1,000 µm were pooled for fermentation in the ALR. These beads were washed thoroughly with water. Two-hundred milliliters of 5% nitric acid was placed on a 100.0 g siran carrier and degassed under vacuum. Beads were then boiled in nitric acid for 12 h under reflux. Contents were decanted and rinsed for 12 h with running distilled water. The carriers were dried in an oven at 150°C. One-hundred-gram siran beads were autoclaved in dry state, and 100 ml of spore suspension was added to the beads. One-hundred milliliters of sterile water was also added. Immobilization in silk sachets. Silk sachets (2 cmϫ1 cm) were sterilized, and a concentrated seed
Influence of Medium Constituents on the Biosynthesis of Cephalosporin-C
Electronic Journal of …, 2007
Cephalosporins together with penicillin belong to the family of β-lactam antibiotics. Cephalosporins are important broad-spectrum antibiotics in the international market and are more resistant to β-lactamases than penicillins. Cephalosporin-C (CPC), the starting material used for the ...