Enhanced ?-lactam antibiotic production by coimmobilization of fungus and alga

1988 ◽  
Vol 10 (12) ◽  
pp. 867-872 ◽  
Author(s):  
Yong Ho Khang ◽  
Hariharan Shankar ◽  
Fred Senatora
Keyword(s):  
Antibiotic Production ◽  
Lactam Antibiotic

Comparison of free and immobilizedCephalosporium acremonium for ?-lactam antibiotic production

1988 ◽  
Vol 10 (10) ◽  
pp. 719-724 ◽  
Author(s):  
Yong-Ho Khang ◽  
Hariharan Shankar ◽  
Fred Senatore
Keyword(s):  
Antibiotic Production ◽  
Lactam Antibiotic

scholarly journals Exploitation of a β-lactamase reporter gene fusion in the carbapenem antibiotic production operon to study adaptive evolution in Erwinia carotovora

Microbiology ◽  
2006 ◽  
Vol 152 (4) ◽  
pp. 1089-1097 ◽  
Author(s):  
Steven D. Bowden ◽  
George P. C. Salmond
Keyword(s):  
Carboxylic Acid ◽  
Adaptive Evolution ◽  
Gene Fusion ◽  
Antibiotic Production ◽  
Erwinia Carotovora ◽  
Lactam Antibiotic ◽  
Resistant Mutants ◽  
Carbapenem Antibiotic ◽  
Reporter Gene Fusion ◽  
Engineered Strain

Erwinia carotovora subsp. carotovora strain ATTn10 produces the β-lactam antibiotic 1-carbapen-2-em-3-carboxylic acid (carbapenem) by expressing the carABCDEFGH operon. Mutants exhibiting increased carbapenem gene transcription were positively selected using an engineered strain with a functional β-lactamase translational fusion in carH, the last gene of the operon. However, spontaneous ampicillin-resistant mutants were isolated even when transcription of carH : : blaM was blocked by a strongly polar mutation in carE. The mechanism of resistance was shown to be due to cryptic IS10 elements transposing upstream of carH : : blaM, thereby providing new promoters enabling carH : : blaM transcription. Southern blots showed that IS10 was present in multicopy in ATTn10. In addition, a Tn10 genetic remnant was discovered. The results offer insights into the genetic archaeology of strain ATTn10 and highlight the powerful impacts of cryptic IS elements in bacterial adaptive evolution.

scholarly journals Effect of phenolic compounds and osmotic stress on the expression of penicillin biosynthetic genes from Penicillium chrysogenum var. halophenolicum strain

2012 ◽  
Vol 2 (1) ◽  
pp. 2 ◽  
Author(s):  
Sumaya Ferreira Guedes ◽  
Ana Lúcia Leitão
Keyword(s):  
Phenolic Compounds ◽  
Penicillium Chrysogenum ◽  
Antibiotic Production ◽  
Beta Lactam ◽  
Biosynthetic Genes ◽  
Expression Levels ◽  
Halotolerant Fungus ◽  
Lactam Antibiotic ◽  
High Concentrations ◽  
Isopenicillin N

Phenol and phenolic compounds are aromatic pollutants that inhibit biological treatment of wastewaters. <em>Penicillium chrysogenum</em> var. <em>halophenolicum</em> is a halotolerant fungus that previously showed the ability to degrade phenol and resorcinol in high salinity conditions. The presence of the penicillin biosynthetic cluster in <em>P. chrysogenum</em> var. <em>halophenolicum</em> was recently described. In this article, we examined the expression of <em>pcbAB</em>, <em>pcbC</em> and <em>penDE</em>, genes responsible for &delta;-(L-&alpha;-aminoadipyl)-L-cysteinyl-D-valine synthetase, isopenicillin N synthase and isopenicillin N acyltransferase activities, respectively, in <em>P. chrysogenum</em> var. <em>halophenolicum</em>. A quantitative PCR (qPCR) approach was used to determine how these genes were expressed in media with 2% and 5.9% NaCl supplemented with phenol, catechol, hydroquinone and resorcinol as the sole carbon source. The effect of salt on the capability of <em>P. chrysogenum</em> var. <em>halophenolicum</em> to degrade aromatic compounds was measured using HPLC. qPCR analysis of RNA extracted from <em>P. chrysogenum</em> var. <em>halophenolicum</em> indicated that the expression levels of <em>pcbAB</em>, <em>pcbC</em> and <em>penDE</em> decreased in high saline concentrations compared to the levels expressed in media with glucose. High concentrations of salt significantly repress the expression of <em>pcbAB</em> and <em>penDE</em>. The <em>pcbC</em> gene was expressed differentially in catechol containing medium. There was no evident relationship between the expression levels of penicillin biosynthetic genes and yields of penicillin. Meanwhile, the presence of phenol and phenolic compounds seems to positively influence the antibiotic production; high concentrations of salt stimulated penicillin production. These results support the hypothesis that phenol, phenolic compounds and high concentrations of salt could act like a stress factor for <em>P. chrysogenum</em> var. <em>halophenolicum</em> resulting in higher yields of &beta;-lactam antibiotic production.

Enzymes in the Pharmaceutical Industry for β-Lactam Antibiotic Production

2019 ◽  
pp. 627-643 ◽  
Author(s):  
Raúl Rodriguez-Herrera ◽  
Luis Enrique Cobos Puc ◽  
Janeth Margarita Ventura Sobrevilla ◽  
Diana Luque ◽  
Cesar S. Cardona-Felix ◽  
...  
Keyword(s):  
Pharmaceutical Industry ◽  
Antibiotic Production ◽  
Lactam Antibiotic

Effect of piperacillin on morphology and viability of gram-negative bacteria

1984 ◽  
Vol 42 ◽  
pp. 218-219
Author(s):  
R. H. Liss
Keyword(s):  
Inhibitory Concentration ◽  
Cytoplasmic Membrane ◽  
Drug Binding ◽  
Gram Negative Bacteria ◽  
Bacterial Cells ◽  
Drug Induced ◽  
Penicillin Binding Proteins ◽  
Lactam Antibiotic ◽  
Drug Free ◽  
Tube Dilution

Piperacillip (PIP) is b-[D(-)-α-(4-ethy1-2,3-dioxo-l-piperzinylcar-bonylamino)-α-phenylacetamido]-penicillanate. The broad spectrum semisynthetic β-lactam antibiotic is believed to effect bactericidal activity through its affinity for penicillin-binding proteins (PBPs), enzymes on the bacterial cytoplasmic membrane that control elongation and septation during cell growth and division. The purpose of this study was to correlate penetration and binding of 14C-PIP in bacterial cells with drug-induced lethal changes assessed by microscopic, microbiologic and biochemical methods.The bacteria used were clinical isolates of Escherichia coli and Pseudomonas aeruginosa (Figure 1). Sensitivity to the drug was determined by serial tube dilution in Trypticase Soy Broth (BBL) at an inoculum of 104 organisms/ml; the minimum inhibitory concentration of piperacillin for both bacteria was 1 μg/ml. To assess drug binding to PBPs, the bacteria were incubated with 14C-PIP (5 μg/0.09 μCi/ml); controls, in drug-free medium.

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