1
|
Characterization of putative mannoprotein in Kluyveromyces lactis for lactase production. Synth Syst Biotechnol 2023; 8:168-175. [PMID: 36733311 PMCID: PMC9880975 DOI: 10.1016/j.synbio.2023.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 12/24/2022] [Accepted: 01/01/2023] [Indexed: 01/07/2023] Open
Abstract
Lactase is a member of the β-galactosidase family of enzymes that can hydrolyze lactose into galactose and glucose. However, extracellular lactase production was still restricted to the process of cell lysis. In this study, lactase-producing Kluyveromyces lactis JNXR-2101 was obtained using a rapid and sensitive method based on the fluorescent substrate 4-methylumbelliferyl-β-d-galactopyranoside. The purified enzyme was identified as a neutral lactase with an optimum pH of 9. To facilitate extracellular production of lactase, a putative mannoprotein KLLA0_E01057g of K. lactis was knocked out. It could effectively promote cell wall degradation and lactase production after lyticase treatment, which showed potential on other extracellular enzyme preparation. After optimizing the fermentation conditions, the lactase yield from mannoprotein-deficient K. lactis JNXR-2101ΔE01057g reached 159.62 U/mL in a 5-L fed-batch bioreactor.
Collapse
|
2
|
Heuker M, Sijbesma JWA, Aguilar Suárez R, de Jong JR, Boersma HH, Luurtsema G, Elsinga PH, Glaudemans AWJM, van Dam GM, van Dijl JM, Slart RHJA, van Oosten M. In vitro imaging of bacteria using 18F-fluorodeoxyglucose micro positron emission tomography. Sci Rep 2017; 7:4973. [PMID: 28694519 PMCID: PMC5504029 DOI: 10.1038/s41598-017-05403-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 06/06/2017] [Indexed: 01/21/2023] Open
Abstract
Positron emission tomography (PET) with fluorine-18-fluorodeoxyglucose (18F-FDG) can be applied to detect infection and inflammation. However, it was so far not known to what extent bacterial pathogens may contribute to the PET signal. Therefore, we investigated whether clinical isolates of frequently encountered bacterial pathogens take up 18F-FDG in vitro, and whether FDG inhibits bacterial growth as previously shown for 2-deoxy-glucose. 22 isolates of Gram-positive and Gram-negative bacterial pathogens implicated in fever and inflammation were incubated with 18F-FDG and uptake of 18F-FDG was assessed by gamma-counting and µPET imaging. Possible growth inhibition by FDG was assayed with Staphylococcus aureus and the Gram-positive model bacterium Bacillus subtilis. The results show that all tested isolates accumulated 18F-FDG actively. Further, 18F-FDG uptake was hampered in B. subtilis pts mutants impaired in glucose uptake. FDG inhibited growth of S. aureus and B. subtilis only to minor extents, and this effect was abrogated by pts mutations in B. subtilis. These observations imply that bacteria may contribute to the signals observed in FDG-PET infection imaging in vivo. Active bacterial FDG uptake is corroborated by the fact that the B. subtilis phosphotransferase system is needed for 18F-FDG uptake, while pts mutations protect against growth inhibition by FDG.
Collapse
Affiliation(s)
- Marjolein Heuker
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, PO Box 30001, 9700 RB, Groningen, The Netherlands
| | - Jürgen W A Sijbesma
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, PO Box 30001, 9700 RB, Groningen, The Netherlands
| | - Rocío Aguilar Suárez
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, PO Box 30001, 9700 RB, Groningen, The Netherlands
| | - Johan R de Jong
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, PO Box 30001, 9700 RB, Groningen, The Netherlands
| | - Hendrikus H Boersma
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, PO Box 30001, 9700 RB, Groningen, The Netherlands.,Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, PO Box 30001, 9700 RB, Groningen, The Netherlands
| | - Gert Luurtsema
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, PO Box 30001, 9700 RB, Groningen, The Netherlands
| | - Philip H Elsinga
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, PO Box 30001, 9700 RB, Groningen, The Netherlands
| | - Andor W J M Glaudemans
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, PO Box 30001, 9700 RB, Groningen, The Netherlands
| | - Gooitzen M van Dam
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, PO Box 30001, 9700 RB, Groningen, The Netherlands.,Department of Surgery, Division of Surgical Oncology and Intensive Care, University of Groningen, University Medical Center Groningen, Hanzeplein 1, PO Box 30001, 9700 RB, Groningen, The Netherlands
| | - Jan Maarten van Dijl
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, PO Box 30001, 9700 RB, Groningen, The Netherlands.
| | - Riemer H J A Slart
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, PO Box 30001, 9700 RB, Groningen, The Netherlands.,Department of Biomedical Photonic Imaging, University of Twente, PO Box 217, 7500 AE, Enschede, The Netherlands
| | - Marleen van Oosten
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, PO Box 30001, 9700 RB, Groningen, The Netherlands
| |
Collapse
|
3
|
Li J, Trivedi P, Wang N. Field Evaluation of Plant Defense Inducers for the Control of Citrus Huanglongbing. PHYTOPATHOLOGY 2016; 106:37-46. [PMID: 26390185 DOI: 10.1094/phyto-08-15-0196-r] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Huanglongbing (HLB) is currently the most economically devastating disease of citrus worldwide and no established cure is available. Defense inducing compounds are able to induce plant resistance effective against various pathogens. In this study the effects of various chemical inducers on HLB diseased citrus were evaluated in four groves (three with sweet orange and one with mandarin) in Florida (United States) for two to four consecutive growing seasons. Results have demonstrated that plant defense inducers including β-aminobutyric acid (BABA), 2,1,3-benzothiadiazole (BTH), and 2,6-dichloroisonicotinic acid (INA), individually or in combination, were effective in suppressing progress of HLB disease. Ascorbic acid (AA) and the nonmetabolizable glucose analog 2-deoxy-D-glucose (2-DDG) also exhibited positive control effects on HLB. After three or four applications for each season, the treatments AA (60 to 600 µM), BABA (0.2 to 1.0 mM), BTH (1.0 mM), INA (0.1 mM), 2-DDG (100 µM), BABA (1.0 mM) plus BTH (1.0 mM), BTH (1.0 mM) plus AA (600 µM), and BTH (1.0 mM) plus 2-DDG (100 µM) slowed down the population growth in planta of 'Candidatus Liberibacter asiaticus', the putative pathogen of HLB and reduced HLB disease severity by approximately 15 to 30% compared with the nontreated control, depending on the age and initial HLB severity of infected trees. These treatments also conferred positive effect on fruit yield and quality. Altogether, these findings indicate that plant defense inducers may be a useful strategy for the management of citrus HLB.
Collapse
Affiliation(s)
- Jinyun Li
- Citrus Research and Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences (IFAS), University of Florida, Lake Alfred 33850
| | - Pankaj Trivedi
- Citrus Research and Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences (IFAS), University of Florida, Lake Alfred 33850
| | - Nian Wang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences (IFAS), University of Florida, Lake Alfred 33850
| |
Collapse
|
7
|
Bond DR, Tsai BM, Russell JB. Physiological characterization of Streptococcus bovis mutants that can resist 2-deoxyglucose-induced lysis. MICROBIOLOGY (READING, ENGLAND) 1999; 145 ( Pt 10):2977-85. [PMID: 10537220 DOI: 10.1099/00221287-145-10-2977] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Streptococcus bovis JB1 does not normally lyse, but stationary phase lysis can be induced by including 2-deoxyglucose (2DG) in the growth medium. Isolates deficient in glucose/2DG phosphotransferase activity (PTS-) also lysed when 2DG was present (Lys+) and this result indicated that 2DG phosphorylation via the PTS was not an obligate requirement for 2DG-induced lysis. Cells and cell walls from 2DG-grown cultures lysed faster when proteinase K was added, but glucose-grown cultures and cell walls were not affected. A lipoteichoic acid (LTA) extract (aqueous phase from hot phenol treatment) from glucose-grown cells inhibited the lysis of 2DG-grown cultures, but a similar extract prepared from 2DG-grown cells was without effect. Thin-layer chromatography and differential staining indicated that wild-type and Lys+ PTS- cells incorporated 2DG into LTA, but lysis-resistant cultures (Lys- PTS+ and Lys- PTS-) did not. LTA from lysis-resistant (Lys- PTS+ and Lys- PTS-) cells grown with glucose and 2DG also prevented 2DG-dependent lysis of the wild-type. LTA could not inhibit degradation of cell walls isolated from 2DG-grown cultures, but LTA inhibited the lysis of Micrococcus lysodeikticus (Micrococcus luteus) cells that were exposed to supernatants from 2DG-grown S. bovis cultures. Group D streptococci (including S. bovis) normally have an alpha-1,2 linked glucose disaccharide (kojibiose) in their LTA, but kojibiose cannot be synthesized from 2DG. This observation suggested that the kojibiose moiety of LTA was involved in autolysin inactivation. Wild-type S. bovis had ATP- as well as PEP-dependent mechanisms of 2DG phosphorylation and one lysis-resistant phenotype (Lys- PTS-) had reduced levels of both activities. However, the Lys- PTS+ phenotype was still able to phosphorylate 2DG via ATP and PEP and this result indicated that some other step of 2DG incorporation into LTA was being inhibited. Based on these results, growth in the presence of 2DG appears to prevent synthesis of normal LTA, which is involved in the regulation of autolytic enzymes.
Collapse
Affiliation(s)
- D R Bond
- Section of Microbiology, Cornell University and Agricultural Research Service, US Department of Agriculture, Ithaca, NY 14853, USA
| | | | | |
Collapse
|