scholarly journals UV Mutation Abnormality

2020 ◽  
Author(s):  
Keyword(s):  
Uv Mutation

scholarly journals Evaluation of fermentation potential of wild and UV-mutated yeasts screened from traditional murcha

2018 ◽  
Vol 2 ◽  
pp. 84-89
Author(s):  
Jeny Subba ◽  
Basanta Kumar Rai ◽  
Dil Kumar Limbu ◽  
Sangen Ruma Rai
Keyword(s):  
Present Finding ◽  
Ethanol Yield ◽  
Triphenyl Tetrazolium Chloride ◽  
Considerable Time ◽  
Tetrazolium Chloride ◽  
Uv Mutation ◽  
Overlay Technique ◽  
The Right ◽  
High Test ◽  
Respiratory Deficient

Murcha (an amylolytic starter) from different parts of Eastern Nepal were screened for fermentative yeasts. The most potential one was UV-mutated (8W lamp at λ = 254 nm and an intensity of 44.21 Wm-2 for 5-50 s) to study the effect of mutation on growth and fermentation properties. Respiratory-deficient mutants (RDMs) that resulted from the mutation were identified by triphenyl tetrazolium chloride (TTC) overlay technique and replica-plated for further isolation. Cell growth, substrate utilization, and ethanol yield of the mutants were compared with normal cells by carrying out fermentation in high-test cane molasses broth of 30 °Bx. An exhaustive screening of the samples resulted in only two murcha viz., from Laxmimarga (LM) and Udayapur (UD), having the desirable fermentation properties. UV-mutation study of UD and LM yeasts (both identified as strains of Saccharomyces cerevisiae) showed 8-12% survival and ~ 22% RDMs yield of the survived cells. Out of the 8 randomly selected RDMs, only UDm4 (colony No. 4 from UD) showed fermentation properties worth further investigation. Comparison of UD, LM and UDm4 by fermenting molasses (high test) broth of 30°Bx showed the least growth of UDm4 but the highest alcohol yield (9% and 16% more compared to UD and LM, respectively). The present finding indicates that it is possible to improve fermentation properties of feral yeasts from murcha by relatively simple UV-mutation approach. Finding the right mutant (the selective screening part), however, may involve considerable time and effort.

scholarly journals Role of DNA Polymerase η in the UV Mutation Spectrum in Human Cells

2003 ◽  
Vol 278 (21) ◽  
pp. 18767-18775 ◽  
Author(s):  
Anne Stary ◽  
Patricia Kannouche ◽  
Alan R. Lehmann ◽  
Alain Sarasin
Keyword(s):  
Dna Polymerase ◽  
Human Cells ◽  
Mutation Spectrum ◽  
Uv Mutation

scholarly journals Epitope spreading toward wild-type melanocyte-lineage antigens rescues suboptimal immune checkpoint blockade responses

2021 ◽  
Vol 13 (581) ◽  
pp. eabd8636
Author(s):  
Jennifer A. Lo ◽  
Masayoshi Kawakubo ◽  
Vikram R. Juneja ◽  
Mack Y. Su ◽  
Tal H. Erlich ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Checkpoint ◽  
Checkpoint Inhibitors ◽  
Checkpoint Blockade ◽  
Wild Type ◽  
Epitope Spreading ◽  
Antitumor Effects ◽  
Fractional Photothermolysis ◽  
Uv Mutation ◽  
Self Antigens

Although immune checkpoint inhibitors (ICIs), such as anti–programmed cell death protein–1 (PD-1), can deliver durable antitumor effects, most patients with cancer fail to respond. Recent studies suggest that ICI efficacy correlates with a higher load of tumor-specific neoantigens and development of vitiligo in patients with melanoma. Here, we report that patients with low melanoma neoantigen burdens who responded to ICI had tumors with higher expression of pigmentation-related genes. Moreover, expansion of peripheral blood CD8+ T cell populations specific for melanocyte antigens was observed only in patients who responded to anti–PD-1 therapy, suggesting that ICI can promote breakdown of tolerance toward tumor-lineage self-antigens. In a mouse model of poorly immunogenic melanomas, spreading of epitope recognition toward wild-type melanocyte antigens was associated with markedly improved anti–PD-1 efficacy in two independent approaches: introduction of neoantigens by ultraviolet (UV) B radiation mutagenesis or the therapeutic combination of ablative fractional photothermolysis plus imiquimod. Complete responses against UV mutation-bearing tumors after anti–PD-1 resulted in protection from subsequent engraftment of melanomas lacking any shared neoantigens, as well as pancreatic adenocarcinomas forcibly overexpressing melanocyte-lineage antigens. Our data demonstrate that somatic mutations are sufficient to provoke strong antitumor responses after checkpoint blockade, but long-term responses are not restricted to these putative neoantigens. Epitope spreading toward T cell recognition of wild-type tumor-lineage self-antigens represents a common pathway for successful response to ICI, which can be evoked in neoantigen-deficient tumors by combination therapy with ablative fractional photothermolysis and imiquimod.

scholarly journals IMPROVEMENT OF P. CHRYSOGENUM BY UV MUTATION FOR OVERPRODUCTION OF CELLULASE AND LIGNINASE

2013 ◽  
Vol 27 (S1) ◽  
Author(s):  
Musa Babalola Oladayo ◽  
O. Abiola Magbagbeola ◽  
Ebuehi O Albert ◽  
O Ngozi Imaga ◽  
Ezikpe N Miriam
Keyword(s):  
Uv Mutation

scholarly journals Improvement ofAspergillus nigerfor Sodium Gluconate Synthesis by UV Mutation Method

2012 ◽  
Vol 9 (4) ◽  
pp. 2052-2057 ◽  
Author(s):  
Rajagopalan Prabu ◽  
Thomas Chand ◽  
Sunhare Raksha
Keyword(s):  
Gluconic Acid ◽  
Parent Strain ◽  
Batch Fermentation ◽  
Glucose Dehydrogenase ◽  
Acid Synthesis ◽  
Sodium Gluconate ◽  
Random Mutation ◽  
Simple Method ◽  
Uv Mutation ◽  
Acid Pathway

The sodium gluconate synthesis pathway was improved inAspergillus nigerby random mutation method.A. nigerwas mutated with Ultraviolet (UV) radiation and the alteration of cell bound enzymes activity of gluconic acid synthesis pathway and sodium gluconate synthesis were evaluated. The improved mutants (A. nigerUV-112) was capable of producing sodium gluconate up to final concentrations of 60 g/L in batch fermentation, which was 3.0 fold higher than the parent strain. It have been observed that the changes in activities of cell bound enzymes related for gluconic acid pathway such as glucose dehydrogenase and glucose oxidase and it were significantly higher than the parent strain. The mutantA. nigerstrain and the simple method used to decrease the production cost and development of fermentation process for industrial production of gluconic acid or its salt.

Screening for the Strain Galactomyces sp. Producing Bioflocculant by UV Mutagenesis

2013 ◽  
Vol 325-326 ◽  
pp. 102-105 ◽  
Author(s):  
Ying Xin Wan ◽  
Lei Shi ◽  
Li Ping Wu ◽  
Pei Jing Tang
Keyword(s):  
Activated Sludge ◽  
Parent Strain ◽  
Culture Medium ◽  
Mutation Breeding ◽  
Uv Mutagenesis ◽  
Uv Mutation ◽  
Stability Experiment ◽  
Flocculating Activity ◽  
Initial Culture ◽  
Flocculation Effect

Strain Galactomyces sp. M-2 from activated sludge was used as parent strain and then UV mutation breeding was performed. Finally we obtained a quality strain UVM8 suitable for the production of bioflocculant which flocculating activity is 92.8%. It showed there is excellent stable flocculating activity for stain UVM8 in the flocculating stability experiment. Further studies showed the best flocculation effect was obtained when C/N ration is 20:2 and pH is 8 in the initial culture medium.

scholarly journals UV Mutagenesis as a Strategy to Enhance Growth and Lipid Productivity of Chlorella sp. 042

2020 ◽  
Vol 5 (3) ◽  
pp. 218
Author(s):  
Rike Rachmayati ◽  
Eva Agustriana ◽  
Delicia Yunita Rahman
Keyword(s):  
Nile Red ◽  
Lipid Productivity ◽  
Biodiesel Production ◽  
Wild Type ◽  
Uv Mutagenesis ◽  
Chlorella Sp ◽  
Uv Mutation ◽  
High Lipid ◽  
Nile Red Fluorescence ◽  
Alternative Feedstock

Microalgae appeared to be an alternative feedstock for renewable biodiesel production due to their capability to accumulate considerable amounts of lipids. In this study, mutagenesis using UVC light with different periods was applied to Chlorella sp. 042 to produce a microalgae strain with high lipid productivity of 45, 60, and 75 min. The Nile red fluorescence method was conducted to select a Chlorella sp. mutant with high neutral lipid and generated one mutant from every UV mutation period, M45-06, M60-02, and M75-21. All of the mutants have higher growth rates than the wild type. Chlorella sp. 042 M60-02 achieved the highest lipid productivity, with 34 mg L-1 day-1. Furthermore, as other major biochemical components, carbohydrate and protein contents were determined. Our results showed that all the mutants enhance their carbohydrate and protein contents compared to the wild type. However, mutations for more than 60 min do not intensely change the protein content of mutant microalgae. Gas chromatography-mass spectrophotometry analysis revealed that M60-02 mutant has similar FAME profiles with the wild type, which contain palmitic acid (C16:0), stearic acid (C 18:0), oleic acid (C18:1), and linoleic acid (C18:2). These results demonstrate that the UV mutation of Chlorella sp. 042 for 60 min is suitable as a source of biodiesel production.

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