scholarly journals Isolation and characterization of a motility-defective mutant of Euglena gracilis

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10002
Author(s):  
Shuki Muramatsu ◽  
Kohei Atsuji ◽  
Koji Yamada ◽  
Kazunari Ozasa ◽  
Hideyuki Suzuki ◽  
...  
Keyword(s):  
Mutant Strain ◽  
Euglena Gracilis ◽  
Model Organism ◽  
Cost Effective ◽  
Industrial Applications ◽  
Culture Conditions ◽  
Wild Type ◽  
Mass Cultivation ◽  
Isolation And Characterization ◽  
Defective Mutant

Euglena gracilis is a green photosynthetic microalga that swims using its flagellum. This species has been used as a model organism for over half a century to study its metabolism and the mechanisms of its behavior. The development of mass-cultivation technology has led to E. gracilis application as a feedstock in various products such as foods. Therefore, breeding of E. gracilis has been attempted to improve the productivity of this feedstock for potential industrial applications. For this purpose, a characteristic that preserves the microalgal energy e.g., reduces motility, should be added to the cultivars. The objective of this study was to verify our hypothesis that E. gracilis locomotion-defective mutants are suitable for industrial applications because they save the energy required for locomotion. To test this hypothesis, we screened for E. gracilis mutants from Fe-ion-irradiated cell suspensions and established a mutant strain, ${\mathrm{M}}_{3}^{-}$ZFeL, which shows defects in flagellum formation and locomotion. The mutant strain exhibits a growth rate comparable to that of the wild type when cultured under autotrophic conditions, but had a slightly slower growth under heterotrophic conditions. It also stores 1.6 times the amount of paramylon, a crystal of β-1,3-glucan, under autotrophic culture conditions, and shows a faster sedimentation compared with that of the wild type, because of the deficiency in mobility and probably the high amount of paramylon accumulation. Such characteristics make E. gracilis mutant cells suitable for cost-effective mass cultivation and harvesting.

Assessing benzene-induced toxicity on wild type Euglena gracilis Z and its mutant strain SMZ

Chemosphere ◽  
2013 ◽  
Vol 93 (10) ◽  
pp. 2381-2389 ◽  
Author(s):  
Cheng Peng ◽  
Dionne M. Arthur ◽  
Homa Teimouri Sichani ◽  
Qing Xia ◽  
Jack C. Ng
Keyword(s):  
Mutant Strain ◽  
Euglena Gracilis ◽  
Wild Type ◽  
Euglena Gracilis Z

scholarly journals Advanced understanding of prokaryotic biofilm formation using a cost-effective and versatile multi-panel adhesion (mPAD) mount

2022 ◽  
Author(s):  
Stefan Schulze ◽  
Heather Schiller ◽  
Jordan Solomonic ◽  
Orkan Telhan ◽  
Kyle Costa ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Cost Effective ◽  
Flow Chamber ◽  
Culture Conditions ◽  
Multiple Time ◽  
Wild Type ◽  
Surface Attachment ◽  
Flowing Liquid ◽  
Multiple Time Points ◽  
Static Conditions

Most microorganisms exist in biofilms, which comprise aggregates of cells surrounded by an extracellular matrix that provides protection from external stresses. Based on the conditions under which they form, biofilm structures vary in significant ways. For instance, biofilms that develop when microbes are incubated under static conditions differ from those formed when microbes encounter the shear forces of a flowing liquid. Moreover, biofilms develop dynamically over time. Here, we describe a cost-effective, 3D-printed coverslip holder that facilitates surface adhesion assays under a broad range of standing and shaking culture conditions. This multi-panel adhesion (mPAD) mount further allows cultures to be sampled at multiple time points, ensuring consistency and comparability between samples and enabling analyses of the dynamics of biofilm formation. As a proof of principle, using the mPAD mount for shaking, oxic cultures, we confirm previous flow chamber experiments showing that Pseudomonas aeruginosa wild type and a phenazine deletion mutant (Δ phz ) form biofilms with similar structure but reduced density in the mutant strain. Extending this analysis to anoxic conditions, we reveal that microcolony and biofilm formation can only be observed under shaking conditions and are decreased in the Δ phz mutant compared to wild-type cultures, indicating that phenazines are crucial for the formation of biofilms if oxygen as an electron acceptor is unavailable. Furthermore, while the model archaeon Haloferax volcanii does not require archaella for surface attachment under static conditions, we demonstrate that H. volcanii mutants that lack archaella are impaired in early stages of biofilm formation under shaking conditions. Importance: Due to the versatility of the mPAD mount, we anticipate that it will aid the analysis of biofilm formation in a broad range of bacteria and archaea. Thereby, it contributes to answering critical biological questions about the regulatory and structural components of biofilm formation and understanding this process in a wide array of environmental, biotechnological, and medical contexts.

scholarly journals The dgc2 gene encoding di-guanylate cyclase suppresses both motility and biofilm formation in the filamentous cyanobacterium Leptolyngbya boryana.

2022 ◽  
Author(s):  
Kazuma Toida ◽  
Wakana Kushida ◽  
Hiroki Yamamoto ◽  
Kyoka Yamamoto ◽  
Kazuma Uesaka ◽  
...  
Keyword(s):  
Mutant Strain ◽  
Biofilm Formation ◽  
Catalytic Domain ◽  
Genetic Model ◽  
Model Organism ◽  
Gliding Motility ◽  
Spontaneous Mutant ◽  
Filamentous Cyanobacterium ◽  
Wild Type

Colony pattern formations of bacteria with motility manifest complicated morphological self-organization phenomena. Leptolyngbya boryana is the filamentous cyanobacterial species, which has been used as a genetic model organism for studying metabolism including photosynthesis and nitrogen-fixation. Although a widely used type strain (wild type) of this species has not been reported to show any motile activity, we isolated a spontaneous mutant strain which shows active motility (gliding activity) to give rise to complicated colony patters, including comet-like wandering clusters and disk-like rotating vortices on solid media. Whole-genome resequencing identified multiple mutations on the genome in the mutant strain. We confirmed that inactivation of a candidate gene, dgc2 (LBDG_02920), in the wild type background was sufficient to give rise to motility and the morphological colony patterns. This gene encodes a protein, containing the GGDEF motif, which is conserved at the catalytic domain of diguanylate cyclase (DGC). Although DGC has been reported to be involved in biofilm formation, the mutant strain lacking dgc2 significantly facilitated biofilm formation, suggesting a role of DGC for suppressing both gliding motility and biofilm formation. Thus, L. boryana provides an excellent genetic model to study dynamic colony pattern formation, and novel insight on a role of c-di-GMP for biofilm formation.

Mutation of AN39-1 for production and characterization of constitutive, thermostable and pH-resistant dextransucrase / Konstitutif, sıcaklığa ve pH’ya dayanıklı dekstransukrazların üretimi ve karakterizasyonu için AN39-1’in mutasyonu

2016 ◽  
Vol 41 (2) ◽  
Author(s):  
Çiğdem Yamaner ◽  
Murat Kemal Avcı ◽  
Aziz Tanrıseven ◽  
İsmail Yavuz Sezen
Keyword(s):  
Mutant Strain ◽  
Parent Strain ◽  
Leuconostoc Mesenteroides ◽  
Industrial Applications ◽  
Wild Type ◽  
Methane Sulfonate ◽  
Ethyl Methane ◽  
Sucrose Medium ◽  
Higher Temperature

AbstractObjective: Leuconostoc mesenteroides AN39-1 has recently been isolated from Crataegus orientalis var. Orientalis. It produces inducible extracellular dextransucrase (EC 2.4.1.5) forming dextran from sucrose. The aim of this study was (1) to obtain constitutive, pH-resistant and thermostable dextransucrase, (2) to characterization of these dextransucrase.Methods: Mutagenesis was carried out on the parent strain (AN39-1) using UV, ethyl methane sulfonate, and N- methyl- N´-nitro-N-nitrosoguanidine. Dextransucrases from wild type (AN39-1) and the mutant strain (A26-2/11) were purified by polyethylene glycol (PEG) precipitation and characterized.Results: Mutants (A26, A26-2, and A26-2/11) hyper producing and constitutive for dextransucrase were isolated. The mutants (A26, A26-2, A26-2/11) produced 7.2, 8.1, and 2.0 times more dextransucrase activity as compared to parent strain on sucrose medium, respectively. In addition, the mutants produced dextransucrase on glucose medium with higher activities (3.0-5.8 times) than what the parental strain produced on sucrose medium. The mutant enzyme (A26-2/11) was much more thermostable than the native enzyme and resistant to pH more than dextransucrase of AN39-1. The dextransucrase from mutant strain was stable up to 35°C and pH of 7.5 for 3 hr.Conclusion: The structures of dextrans produced by wild type and mutant enzymes were similar to commercially produced B-512 F dextran. Thus, the newly dextransucrases produced by mutant strain could find industrial applications at higher temperature and pH.

scholarly journals Isolation and characterization of a high iturin yielding Bacillus velezensis UV mutant with improved antifungal activity

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0234177
Author(s):  
Young Tae Kim ◽  
Sung Eun Kim ◽  
Won Jung Lee ◽  
Zhao Fumei ◽  
Min Sub Cho ◽  
...  
Keyword(s):  
Biological Control ◽  
Antifungal Activity ◽  
Mutant Strain ◽  
Fusarium Wilt ◽  
Potential Candidate ◽  
Wild Type ◽  
Bacillus Velezensis ◽  
Sclerotinia Rot ◽  
Isolation And Characterization

To isolate Bacillus velezensis mutants with improved antifungal activity for use in the biological control of phytopathogenic fungi, wild-type Bacillus velezensis KRF-001 producing iturin, surfactin, and fengycin was irradiated by ultraviolet (UV) rays. The in vitro and in vivo antifungal activities of UV mutants and characterization of the cyclic lipopeptides produced by a selected mutant were examined. A mutant strain yielding high levels of iturin showed over 2-fold higher antifungal activity than the wild-type against Fusarium oxysporum. A potent suppressive effect of the mutant was also observed on spore germination of Botrytis cinerea, the causative agent of cucumber gray mold, at different butanol extract concentrations. Further analysis of the mutant by real-time PCR and high-performance liquid chromatography revealed increased expression of iturin and surfactin biosynthesis genes as well as enhanced production of iturin and surfactin metabolites. However, the amounts of fengycin obtained from the mutant strain BSM54 were significantly lesser than those of iturin and surfactin. Particularly, iturin A production by the mutant was 3.5-fold higher than that of the wild-type, suggesting that the higher antifungal activity of the mutant against F. oxysporum resulted from the increased expression of biosynthesis genes associated with iturin production. The commercial greenhouse experiment using soil naturally infested with Sclerotinia sclerotiorum (sclerotinia rot) and F. oxysporum (fusarium wilt) showed that the mutant strain reduced sclerotinia rot and fusarium wilt diseases (P = 0.05) more effectively than the wild-type and commercially available product Cillus® in Korea. These results suggest that the mutant with high iturin yield is a potential candidate for the development of a biological control agent in agriculture.

scholarly journals Advanced understanding of prokaryotic biofilm formation using a cost-effective and versatile multi-panel adhesion (mPAD) mount

2021 ◽  
Author(s):  
Stefan Schulze ◽  
Heather Schiller ◽  
Jordan Solomonic ◽  
Orkan Telhan ◽  
Kyle Costa ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Cost Effective ◽  
Flow Chamber ◽  
Culture Conditions ◽  
Multiple Time ◽  
Wild Type ◽  
Flowing Liquid ◽  
External Stresses ◽  
Multiple Time Points ◽  
Static Conditions

AbstractMost microorganisms exist in biofilms, which comprise aggregates of cells surrounded by an extracellular matrix that provides protection from external stresses. Based on the conditions under which they form, biofilm structures vary in significant ways. For instance, biofilms that develop when microbes are incubated under static conditions differ from those formed when microbes encounter the shear forces of a flowing liquid. Moreover, biofilms develop dynamically over time. Here, we describe a cost-effective, 3D-printed coverslip holder that facilitates surface adhesion assays under a broad range of standing and shaking culture conditions. This multi-panel adhesion (mPAD) mount further allows cultures to be sampled at multiple time points, ensuring consistency and comparability between samples and enabling analyses of the dynamics of biofilm formation. As a proof of principle, using the mPAD mount for shaking, oxic cultures, we confirm previous flow chamber experiments showing that Pseudomonas aeruginosa wild type and a phenazine deletion mutant (Δphz) form similar biofilms. Extending this analysis to anoxic conditions, we reveal that microcolony and biofilm formation can only be observed under shaking conditions and are decreased in the Δphz mutant compared to wild-type cultures, indicating that phenazines are crucial for the formation of biofilms if oxygen as an electron acceptor is not available. Furthermore, while the model archaeon Haloferax volcanii does not require archaella for attachment to surfaces under static conditions, we demonstrate that H. volcanii mutants that lack archaella are negatively affected in their early stages of biofilm formation under shaking conditions.ImportanceDue to the versatility of the mPAD mount, we anticipate that it will aid the analysis of biofilm formation in a broad range of bacteria and archaea. Thereby, it contributes to answering critical biological questions about the regulatory and structural components of biofilm formation and understanding this process in a wide array of environmental, biotechnological, and medical contexts.

Magnesium Starved Cells of Euglena gracilis - a Possible Model System for Studying Mg2+ Influx?

1996 ◽  
Vol 51 (3-4) ◽  
pp. 165-173
Author(s):  
Gabriele Scholten-Beck
Keyword(s):  
Euglena Gracilis ◽  
Culture Medium ◽  
Binding Assay ◽  
Lectin Binding ◽  
Model Organism ◽  
Culture Conditions ◽  
Free Medium ◽  
Drastic Reduction ◽  
Surface Carbohydrates ◽  
Oval Shape

Abstract In order to obtain a model which allows to directly study Mg2+ influx into the cell, Mg2+ deficiency was induced in the unicellular photoautotrophic flagellate Euglena gracilis. Lack of Mg2+ in the culture medium leads to a number of morphological, biochemical, and physio­ logical changes in E uglena gracilis. The rate of cell division was reduced under Mg2+-free conditions. Subsequently an enlargement of the cells was observed and they changed from spindle-like to oval shape. The Mg2+-starved cells were well filled with paramylon granules, while their motility and vitality was not impaired. Concurrently with the larger cell size the protein-, carbohydrate-, and chlorophyll content of the cells increased. Further changes were observed in the surface carbohydrates. The proportion of cells with galactose, N-acetyl-galac-tosamine and mannose on the cell surface rose in the Mg2+-starved cultures, shown in a lectin-binding assay. Fucose was found on the pellicle of Mg2+-starved cells only. Cultivation of E uglena gracilis in Mg2+-free medium induced a drastic reduction of the intracellular Mg2+ concentration already after 24 h (from 233 nmol/106 cells to 82 nmol/106 cells). When Mg2+ was made available again, the Mg2+-starved cells took them up rapidly and the intracellular concentration of free Mg2+ rose. As Mg2+ depletion could be induced in Euglena gracilis easily by manipulating the culture conditions and as the cells remained viable, it was con­ cluded that this flagellate can be used as a model organism for studying the Mg2+ uptake of eukaryotic cells.

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