The production of L-asparaginase, an enzyme widely used in cancer chemotherapy, is mainly regulated by carbon catabolite repression and oxygen. This study was carried out to understand how different carbon sources and Vitreoscilla hemoglobin (VHb) affect the production of this enzyme in Pseudomonas aeruginosa and its VHb-expressing recombinant strain (PaJC). Both strains grown with various carbon sources showed a distinct profile of the enzyme activity. Compared to no carbohydrate supplemented medium, glucose caused a slight repression of L-asparaginase in P. aeruginosa, while it stimulated it in the PaJC strain. Glucose, regarded as one of the inhibitory sugars for the production L-asparaginase by other bacteria, was determined to be the favorite carbon source compared to lactose, glycerol and mannitol. Furthermore, contrary to common knowledge of oxygen repression of L-asparaginase in other bacteria, oxygen uptake provided by VHb was determined to even stimulate the L-asparaginase synthesis by P. aeruginosa. This study, for the first time, shows that in P. aeruginosa utilizing a recombinant oxygen uptake system, VHb, L-asparaginase synthesis is stimulated by glucose and other carbohydrate sources compared to the host strain. It is concluded that carbon catabolite and oxygen repression of L-asparaginase in fermentative bacteria is not the case for a respiratory non-fermentative bacterium like P. aeruginosa.
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http://dx.doi.org/10.1002/biot.200500048 | DOI Listing |
Prep Biochem Biotechnol
December 2024
Post Graduate Department of Biosciences & Biotechnology, Fakir Mohan University, Balasore, Odisha, India.
Sorbitol, known as D-Glucitol, is a hexose sugar alcohol that occurs naturally in various fruits, including berries, cherries, plums, pears, and apples. It is noteworthy that sorbitol can be metabolized by microbes, plants, and humans through distinct pathways. Nevertheless, in bacteria like (), sorbitol is not the primary carbon source and its utilization is generally suppressed due to carbon catabolite repression.
View Article and Find Full Text PDFBioprocess Biosyst Eng
October 2022
School of Pharmaceutical Sciences, Department of Bioprocess Engineering and Biotechnology, São Paulo State University (UNESP), Araraquara, São Paulo, 14800-903, Brazil.
L-Asparaginase (L-ASNase) is an enzyme applied in the treatment of lymphoid malignancies. However, an innovative L-ASNase with high yield and lower side effects than the commercially available preparations are still a market requirement. Here, a new-engineered Bacillus subtilis strain was evaluated for Aliivibrio fischeri L-ASNase II production, being the bioprocess development and the enzyme characterization studied.
View Article and Find Full Text PDFFood Microbiol
June 2022
Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA; Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA. Electronic address:
While Cas9-based genome editing enabled precise and sophisticated genetic perturbations in conventional and non-conventional yeast strains, its applications for food fermentations have been extremely limited. In order to improve quality and flavor of various yeast-fermented foods, we isolated and engineered a diploid or polyploid Saccharomyces cerevisiae strain (N1) which exhibits robust sugar fermentation, strong acid tolerance, and rapid gas production from Korean Nuruk. First, RGT2 and SNF3 coding for glucose sensors were deleted to increase respiration.
View Article and Find Full Text PDFPharmaceutics
August 2021
Health Sciences School, University of Brasília, Brasília 70910-900, Brazil.
l-asparaginase is an enzyme used as treatment for acute lymphoblastic leukemia (ALL) due to its ability to hydrolyze l-asparagine, an essential amino acid synthesized by normal cells unlike neoplastic cells. The adverse effects of l-asparaginase formulations are associated with its glutaminase activity and bacterial origin; therefore, it is important to find new sources of l-asparaginase-producing eukaryotic microorganisms with low glutaminase activity. This work evaluated the biotechnological potential of filamentous fungi isolated from Brazilian Savanna soil and plants for l-asparaginase production.
View Article and Find Full Text PDFBiochem Pharmacol
September 2018
Department of Woman's and Child's Health, Oncohematology Laboratory, University of Padova, 35128 Padova, Italy. Electronic address:
Choline kinase alpha 1 (ChoKα1) has recently become an interesting therapeutic target since its overexpression has been associated to tumorigenesis in many cancers. Nevertheless, little is known regarding hematological malignancies. In this manuscript, we investigated the effect of a novel and selective ChoKα inhibitor EB-3D in T acute lymphoblastic leukemia (T-ALL).
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