Polymeric Formulations of Liquid Inoculants with Rhizobia Exopolysaccharides Increase Survival and Symbiotic Efficiency of Bradyrhizobium Strains with Cowpea and Soybean

Mapping Intimacies ◽

10.21203/rs.3.rs-451580/v1 ◽

2021 ◽

Author(s):

Thiago Palhares Farias ◽

Bruno Lima Soares ◽

Claudio Sérgio Barbosa D’Eça ◽

Fatima M S Moreira

Keyword(s):

Cell Viability ◽

Symbiotic Efficiency ◽

Colony Forming Units ◽

Commercial Inoculant

Abstract We studied the survival of four elite strains of Bradyrhizobium in liquid inoculants with three formulations with EPS extracted from other rhizobia genera, and their symbiotic efficiency, with soybean and cowpea, in a greenhouse. For this purpose, we verified the utility of formulations for maintaining the cell viability of strains by counting the colony forming units (CFU) per milliliter of the liquid inoculants with formulations over 90 days. Survival of the soybean inoculant strains, 29W and CPAC15, in the PEPS formulation had the largest number of CFU (> 1010 mL− 1) after 90 days. For the cowpea inoculant strains, INPA3-1B and UFLA3-84, the formulations REPS1 had the largest number of CFU (> 1010 mL− 1) after 90 days. Symbiotic efficiency in soybean of the formulations PEPS and REPS2 was higher than that shown by the commercial inoculant. For cowpea, the three formulations with EPS showed symbiotic efficiency bigger than that of the commercial inoculant.

Download Full-text

Application of the Resazurin Cell Viability Assay to Monitor Escherichia coli and Salmonella Typhimurium Inactivation Mediated by Phages

Antibiotics ◽

10.3390/antibiotics10080974 ◽

2021 ◽

Vol 10 (8) ◽

pp. 974

Author(s):

Pedro Costa ◽

Ana T. P. C. Gomes ◽

Márcia Braz ◽

Carla Pereira ◽

Adelaide Almeida

Keyword(s):

Cell Viability ◽

Bacterial Infections ◽

Screening Methods ◽

Bacterial Inactivation ◽

Bacterial Strains ◽

Cell Viability Assay ◽

Viability Assay ◽

Resazurin Assay ◽

Colony Forming Units ◽

Colony Counting

Bacterial inactivation using bacteriophages (or phages) has emerged as an effective solution for bacterial infections, but the screening methods used to evaluate the effectiveness of the phages to inactivate bacteria are not fast, reliable or precise enough. The efficiency of bacterial inactivation by phages has been evaluated by monitoring bacterial concentration either by counting colony-forming units (CFU), a laborious and time-consuming method, or by monitoring the optical density (OD), a less sensitive method. In this study, the resazurin cell viability assay was used to monitor the viability of bacteria from different genera during the inactivation by different phages, and the results were compared with the standard methods used to assess bacterial inactivation. The results showed that the resazurin colorimetric cell viability assay produces similar results to the standard method of colony-counting and giving, and also more sensitive results than the OD method. The resazurin assay can be used to quickly obtain the results of the cell viability effect profile using two different bacterial strains and several different phages at the same time, which is extremely valuable in screening studies. Moreover, this methodology is established as an effective, accurate and rapid method when compared to the ones widely used to monitor bacterial inactivation mediated by phages.

Download Full-text

Comparison of the Effects of Different Cryoprotectants on Stem Cells from Umbilical Cord Blood

Stem Cells International ◽

10.1155/2016/1396783 ◽

2016 ◽

Vol 2016 ◽

pp. 1-7 ◽

Cited By ~ 11

Author(s):

Gecai Chen ◽

Aihuan Yue ◽

Zhongbao Ruan ◽

Yigang Yin ◽

Ruzhu Wang ◽

...

Keyword(s):

Stem Cells ◽

Cell Viability ◽

Cord Blood ◽

Umbilical Cord ◽

Umbilical Cord Blood ◽

Cell Apoptosis ◽

Colony Forming Units ◽

Group A ◽

Group B ◽

Group D

Purpose. Cryoprotectants (CPA) for stem cells from umbilical cord blood (UCB) have been widely developed based on empirical evidence, but there is no consensus on a standard protocol of preservation of the UCB cells.Methods. In this study, UCB from 115 donors was collected. Each unit of UCB was divided into four equal parts and frozen in different kinds of cryoprotectant as follows: group A, 10% ethylene glycol and 2.0% dimethyl sulfoxide (DMSO) (v/v); group B, 10% DMSO and 2.0% dextran-40; group C, 2.5% DMSO (v/v) + 30 mmol/L trehalose; and group D, without CPA.Results. CD34+, cell viability, colony forming units (CFUs), and cell apoptosis of pre- and postcryopreservation using three cryoprotectants were analyzed. After thawing, significant differences in CD34+count, CFUs, cell apoptosis, and cell viability were observed among the four groups(P<0.05). Conclusion. The low concentration of DMSO with the addition of trehalose might improve the cryopreservation outcome.

Download Full-text

Cell Viability of Candida albicans Against the Antifungal Activity of Thymol

Brazilian Dental Journal ◽

10.1590/0103-6440201300052 ◽

2014 ◽

Vol 25 (4) ◽

pp. 277-281 ◽

Cited By ~ 13

Author(s):

Laís César de Vasconcelos ◽

Fabio Correia Sampaio ◽

Allan de Jesus dos Reis Albuquerque ◽

Laurylene César de Souza Vasconcelos

Keyword(s):

Candida Albicans ◽

Antifungal Activity ◽

Cell Viability ◽

Acrylic Resin ◽

Mean Value ◽

Denture Stomatitis ◽

Minimum Fungicidal Concentration ◽

Colony Forming Units ◽

Significant Difference ◽

Syto 9

Candida albicans is a commensal fungus, but circumstantially it may cause superficial infections of the mucous membranes, such as denture stomatitis, when a biofilm is formed on the surface of dental prostheses. This study evaluated the cell viability of C. albicans biofilms against the antifungal activity of thymol when compared with miconazole, by the fluorescence imaging using SYTO 9 and propidium iodide dyes, and counting of colony forming units. C. albicans standard strains (ATCC 11006) were used. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of drugs were determined by broth microdilution tests and the inoculum was standardized to match 0.5 on the McFarland scale (106 cfu/mL). Biofilms were grown on the surface of acrylic resin disks in parallel flow chambers from Sabouraud broth supplemented with 10% dextrose. For counting of colony forming units, the fungal solution was sequentially diluted and plated in Sabouraud dextrose agar. Data were analyzed using two-way ANOVA and Tukey's test (a=5%). Biofilms treated with thymol and miconazole presented low numbers of viable cells at the evaluated exposure times. There was statistically significant difference (p<0.05) when compared with control, and the mean value of the exposure times between miconazole and thymol did not differ significantly (p>0.05). In conclusion, both drugs have similar efficiency as antifungal agents against biofilms of C. albicans formed on acrylic surfaces.

Download Full-text

Streptococcus mutans Biofilm Formation and Cell Viability on Polymer-infiltrated Ceramic and Yttria-stabilized Polycrystalline Zirconium Dioxide Ceramic

Operative Dentistry ◽

10.2341/18-278-l ◽

2019 ◽

Vol 44 (6) ◽

pp. E271-E278 ◽

Cited By ~ 2

Author(s):

MA Bottino ◽

SMB Pereira ◽

M Amaral ◽

NVM Milhan ◽

CA Pereira ◽

...

Keyword(s):

Cell Viability ◽

Streptococcus Mutans ◽

Biofilm Formation ◽

Zirconium Dioxide ◽

Laser Scanning ◽

Human Fibroblasts ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Colony Forming Units ◽

Zirconium Dioxide Ceramic

SUMMARY Objective: The aim of this study was to investigate the biofilm formation and cell viability of a polymer-infiltrated ceramic (PIC) and an yttria-stabilized polycrystalline zirconium dioxide ceramic (Y-TZP). The null hypothesis was that there would be no difference in biofilm formation and cell viability between the materials. Methods and Materials: Streptococcus mutans biofilm was analyzed with scanning electron microscopy (SEM), confocal laser scanning microscopy, and colony counting (colony-forming units/mL). The cell viability (fibroblasts) of both materials was measured with 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl tetrazolium) (MTT) test. Roughness measurements were also performed. Results: The PIC displayed higher roughness but showed similar colony-forming units and biovolume values to those of Y-TZP. SEM showed a higher amount of adhered fibroblasts on the PIC surface on the first day and similar amounts on both materials after seven days. Moreover, the materials were biocompatible with human fibroblasts. Conclusion: PIC and Y-TZP are biocompatible and present the same characteristics for biofilm formation; therefore, they are indicated for indirect restorations and implant abutments.

Download Full-text

Cytoprotective Effect of Tocotrienol-Rich Fraction and α-Tocopherol Vitamin E Isoforms Against Glutamate-Induced Cell Death in Neuronal Cells

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831/a000201 ◽

2014 ◽

Vol 84 (3-4) ◽

pp. 0140-0151 ◽

Cited By ~ 11

Author(s):

Thilaga Rati Selvaraju ◽

Huzwah Khaza’ai ◽

Sharmili Vidyadaran ◽

Mohd Sokhini Abd Mutalib ◽

Vasudevan Ramachandran ◽

...

Keyword(s):

Vitamin E ◽

Cell Viability ◽

Neuronal Cells ◽

Positive Control ◽

Post Treatment ◽

Mitochondrial Activity ◽

Before And After ◽

Pre Treatment ◽

Tocotrienol Rich Fraction ◽

Major Mediator

Glutamate is the major mediator of excitatory signals in the mammalian central nervous system. Extreme amounts of glutamate in the extracellular spaces can lead to numerous neurodegenerative diseases. We aimed to clarify the potential of the following vitamin E isomers, tocotrienol-rich fraction (TRF) and α-tocopherol (α-TCP), as potent neuroprotective agents against glutamate-induced injury in neuronal SK-N-SH cells. Cells were treated before and after glutamate injury (pre- and post-treatment, respectively) with 100 - 300 ng/ml TRF/α-TCP. Exposure to 120 mM glutamate significantly reduced cell viability to 76 % and 79 % in the pre- and post-treatment studies, respectively; however, pre- and post-treatment with TRF/α-TCP attenuated the cytotoxic effect of glutamate. Compared to the positive control (glutamate-injured cells not treated with TRF/α-TCP), pre-treatment with 100, 200, and 300 ng/ml TRF significantly improved cell viability following glutamate injury to 95.2 %, 95.0 %, and 95.6 %, respectively (p < 0.05).The isomers not only conferred neuroprotection by enhancing mitochondrial activity and depleting free radical production, but also increased cell viability and recovery upon glutamate insult. Our results suggest that vitamin E has potent antioxidant potential for protecting against glutamate injury and recovering glutamate-injured neuronal cells. Our findings also indicate that both TRF and α-TCP could play key roles as anti-apoptotic agents with neuroprotective properties.

Download Full-text