scholarly journals Studies on Induced Variation in the Rhizobia. I. Defined Media and Nodulation Test Techniques

1960 ◽  
Vol 8 (6) ◽  
pp. 349-352 ◽  
Author(s):  
E. A. Schwinghamer
Keyword(s):  
Defined Media ◽  
Induced Variation ◽  
Nodulation Test

Photo-induced variation of magnetism in coordination polymers with ligand-based electron transfer

2021 ◽  
Author(s):  
Yan-Lei Lu ◽  
Wen-Long Lan ◽  
Wei Shi ◽  
Qionghua Jin ◽  
Peng Cheng
Keyword(s):  
Electron Transfer ◽  
Coordination Polymers ◽  
Optical Memory ◽  
High Density ◽  
Information Storage ◽  
Memory Devices ◽  
Storage Materials ◽  
Potential Applications ◽  
Induced Variation

Photo-induced variation of magnetism from ligand-based electron transfer have been extensively studied because of their potential applications in magneto-optical memory devices, light-responsive switches, and high-density information storage materials. In this...

scholarly journals The metabolic profile of Bifidobacterium dentium reflects its status as a human gut commensal

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Melinda A. Engevik ◽  
Heather A. Danhof ◽  
Anne Hall ◽  
Kristen A. Engevik ◽  
Thomas D. Horvath ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Metabolic Pathways ◽  
Glycosyl Hydrolase ◽  
Acid Resistance ◽  
Human Gut ◽  
Nutrient Sources ◽  
Metabolic Plasticity ◽  
Defined Media ◽  
High Viability ◽  
Ph Range

Abstract Background Bifidobacteria are commensal microbes of the mammalian gastrointestinal tract. In this study, we aimed to identify the intestinal colonization mechanisms and key metabolic pathways implemented by Bifidobacterium dentium. Results B. dentium displayed acid resistance, with high viability over a pH range from 4 to 7; findings that correlated to the expression of Na+/H+ antiporters within the B. dentium genome. B. dentium was found to adhere to human MUC2+ mucus and harbor mucin-binding proteins. Using microbial phenotyping microarrays and fully-defined media, we demonstrated that in the absence of glucose, B. dentium could metabolize a variety of nutrient sources. Many of these nutrient sources were plant-based, suggesting that B. dentium can consume dietary substances. In contrast to other bifidobacteria, B. dentium was largely unable to grow on compounds found in human mucus; a finding that was supported by its glycosyl hydrolase (GH) profile. Of the proteins identified in B. dentium by proteomic analysis, a large cohort of proteins were associated with diverse metabolic pathways, indicating metabolic plasticity which supports colonization of the dynamic gastrointestinal environment. Conclusions Taken together, we conclude that B. dentium is well adapted for commensalism in the gastrointestinal tract.

scholarly journals Transcriptional Profiling of Porcine Blastocysts Produced In Vitro in a Chemically Defined Culture Medium

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1414
Author(s):  
Josep M. Cambra ◽  
Emilio A. Martinez ◽  
Heriberto Rodriguez-Martinez ◽  
Maria A. Gil ◽  
Cristina Cuello
Keyword(s):  
Culture Medium ◽  
Embryo Quality ◽  
Transcriptional Profiling ◽  
Defined Medium ◽  
Platelet Factor ◽  
Defined Media ◽  
Defined Culture ◽  
The Impact

The development of chemically defined media is a growing trend in in vitro embryo production (IVP). Recently, traditional undefined culture medium with bovine serum albumin (BSA) has been successfully replaced by a chemically defined medium using substances with embryotrophic properties such as platelet factor 4 (PF4). Although the use of this medium sustains IVP, the impact of defined media on the embryonic transcriptome has not been fully elucidated. This study analyzed the transcriptome of porcine IVP blastocysts, cultured in defined (PF4 group) and undefined media (BSA group) by microarrays. In vivo-derived blastocysts (IVV group) were used as a standard of maximum embryo quality. The results showed no differentially expressed genes (DEG) between the PF4 and BSA groups. However, a total of 2780 and 2577 DEGs were detected when comparing the PF4 or the BSA group with the IVV group, respectively. Most of these genes were common in both in vitro groups (2132) and present in some enriched pathways, such as cell cycle, lysosome and/or metabolic pathways. These results show that IVP conditions strongly affect embryo transcriptome and that the defined culture medium with PF4 is a guaranteed replacement for traditional culture with BSA.

scholarly journals Barley somatic embryogenesis-an attempt to modify variation induced in tissue culture

2021 ◽  
Vol 28 (1) ◽  
Author(s):  
Renata Orłowska
Keyword(s):  
Tissue Culture ◽  
Somatic Embryogenesis ◽  
Taguchi Method ◽  
Culture Conditions ◽  
Dna Demethylation ◽  
Silver Ion ◽  
Donor Plant ◽  
In Vitro Tissue Culture ◽  
Induced Variation

Abstract Background Somatic embryogenesis is a phenomenon carried out in an environment that generates abiotic stress. Thus, regenerants may differ from the source of explants at the morphological, genetic, and epigenetic levels. The DNA changes may be the outcome of induction media ingredients (i.e., copper and silver ions) and their concentrations and time of in vitro cultures. Results This study optimised the level of copper and silver ion concentration in culture media parallel with the induction medium longevity step towards obtaining barley regenerants via somatic embryogenesis with a minimum or maximum level of tissue culture-induced differences between the donor plant and its regenerants. The optimisation process is based on tissue culture-induced variation evaluated via the metAFLP approach for regenerants derived under varying in vitro tissue culture conditions and exploited by the Taguchi method. In the optimisation and verification experiments, various copper and silver ion concentrations and the different number of days differentiated the tested trials concerning the tissue culture-induced variation level, DNA demethylation, and de novo methylation, including symmetric (CG, CHG) and asymmetric (CHH) DNA sequence contexts. Verification of optimised conditions towards obtaining regenerants with minimum and maximum variability compared to donor plants proved useful. The main changes that discriminate optimised conditions belonged to DNA demethylation events with particular stress on CHG context. Conclusions The combination of tissue culture-induced variation evaluated for eight experimental trials and implementation of the Taguchi method allowed the optimisation of the in vitro tissue culture conditions towards the minimum and maximum differences between a source of tissue explants (donor plant) and its regenerants from somatic embryos. The tissue culture-induced variation characteristic is mostly affected by demethylation with preferences towards CHG sequence context.

scholarly journals Composition of Pseudomonas aeruginosa slime

1969 ◽  
Vol 112 (4) ◽  
pp. 521-525 ◽  
Author(s):  
M. R. W. Brown ◽  
J. H. Scott Foster ◽  
J. R. Clamp
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Hyaluronic Acid ◽  
Nucleic Acid ◽  
Growth Medium ◽  
Extraction Procedure ◽  
The Other ◽  
Minor Components ◽  
Polysaccharide Fraction ◽  
Defined Media ◽  
Rna And Dna

1. The slime produced by eight strains of Pseudomonas aeruginosa on a number of different media was demonstrated to be qualitatively the same. Small quantitative differences may be occasioned by differences in the extraction procedure, the growth medium or the strain of organism used. 2. The slime was shown to be predominantly polysaccharide with some nucleic acid material and a small amount of protein. 3. The hydrolysed polysaccharide fraction consists mainly of glucose with smaller amounts of mannose. This accounts for some 50–60% of the total slime. In addition, there is some 5% of hyaluronic acid. The nucleic acid material represents approx. 20% of the total weight, and is composed of both RNA and DNA. 4. Minor components are protein, rhamnose and glucosamine, the protein being less than 5% of the total. 5. Hyaluronic acid is produced in greater quantities from nutrient broth than from chemically defined media, and is more firmly attached to the cells than the other components.

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