scholarly journals Characterization of 3-chlorobenzoate degrading aerobic bacteria isolated under various environmental conditions

2000 ◽  
Vol 32 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Janneke Krooneman ◽  
Arne O. Sliekers ◽  
Teresa M. Pedro Gomes ◽  
Larry J. Forney ◽  
Jan C. Gottschal
Keyword(s):  
Environmental Conditions ◽  
Aerobic Bacteria

scholarly journals Microscopic Image Segmentation and Morphological Characterization of Novel Chitosan/Silica Nanoparticle/Nisin Films Using Antimicrobial Technique for Blueberry Preservation

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 303
Author(s):  
Rokayya Sami ◽  
Schahrazad Soltane ◽  
Mahmoud Helal
Keyword(s):  
Ph Value ◽  
Silica Nanoparticle ◽  
Morphological Characterization ◽  
Aerobic Bacteria ◽  
Nano Materials ◽  
Elongation At Break ◽  
Stable Suspension ◽  
Average Size ◽  
Material Ductility

In the current work, the characterization of novel chitosan/silica nanoparticle/nisin films with the addition of nisin as an antimicrobial technique for blueberry preservation during storage is investigated. Chitosan/Silica Nanoparticle/N (CH-SN-N) films presented a stable suspension as the surface loads (45.9 mV) and the distribution was considered broad (0.62). The result shows that the pH value was increased gradually with the addition of nisin to 4.12, while the turbidity was the highest at 0.39. The content of the insoluble matter and contact angle were the highest for the Chitosan/Silica Nanoparticle (CH-SN) film at 5.68%. The use of nano-materials in chitosan films decreased the material ductility, reduced the tensile strength and elongation-at-break of the membrane. The coated blueberries with Chitosan/Silica Nanoparticle/N films reported the lowest microbial contamination counts at 2.82 log CFU/g followed by Chitosan/Silica Nanoparticle at 3.73 and 3.58 log CFU/g for the aerobic bacteria, molds, and yeasts population, respectively. It was observed that (CH) film extracted 94 regions with an average size of 449.10, at the same time (CH-SN) film extracted 169 regions with an average size of 130.53. The (CH-SN-N) film presented the best result at 5.19%. It could be observed that the size of the total region of the fruit for the (CH) case was the smallest (1663 pixels), which implied that the fruit lost moisture content. As a conclusion, (CH-SN-N) film is recommended for blueberry preservation to prolong the shelf-life during storage.

Characterization of NH4-montmorillonite coexisting with NH4Cl salt at different aggregation states. Application to Ceres.

2021 ◽  
Author(s):  
Victoria Munoz-Iglesias ◽  
Maite Fernández-Sampedro ◽  
Carolina Gil-Lozano ◽  
Laura J. Bonales ◽  
Oscar Ercilla Herrero ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Spectroscopic Data ◽  
External Surface ◽  
Deionized Water ◽  
Asteroid Belt ◽  
Aqueous Alteration ◽  
Dawn Mission ◽  
Main Asteroid Belt ◽  
Spectroscopic Signatures

<p>Ceres, dwarf planet of the main asteroid belt, is considered a relic ocean world since the Dawn mission discovered evidences of aqueous alteration and cryovolcanic activity [1]. Unexpectedly, a variety of ammonium-rich minerals were identified on its surface, including phyllosilicates, carbonates, and chlorides [2]. Although from the Dawn’s VIR spectroscopic data it was not possible to specify the exact type of phyllosilicates observed, montmorillonite is considered a good candidate owing to its ability to incorporate NH<sub>4</sub><sup>+</sup> in its interlayers [3]. Ammonium-rich phases are usually found at greater distances from the Sun. Hence, the study on their stability at environmental conditions relevant to Ceres’ interior and of its regolith can help elucidate certain ambiguities concerning the provenance of its precursor materials.</p> <p>In this study, it was investigated the changes in the spectroscopic signatures of the clay mineral montmorillonite after (a) being immersed in ammonium chloride aqueous solution and, subsequently, (b) washed with deionized water. After each treatment, samples were submitted to different environmental conditions relevant to the surface of Ceres. For one experiment, they were frozen overnight at 193 K, and then subjected to 10<sup>-5</sup> bar for up to 4 days in a Telstar Cryodos lyophilizer. For the other, they were placed inside the Planetary Atmospheres and Surfaces Chamber (PASC) [4] for 1 day at 100 K and 5.10<sup>-8</sup> bar. The combination of different techniques, i.e., Raman and IR spectroscopies, XRD, and SEM/EDX, assisted the assignment of the bands to each particular molecule. In this regard, the signatures of the mineral external surface were distinguished from the interlayered NH<sub>4</sub><sup>+ </sup>cations. The degree of compaction of the samples resulted crucial on their stability and spectroscopic response, being stiff smectites more resistant to low temperatures and vacuum conditions. In ground clay minerals, a decrease in the basal space with a redshift of the interlayered NH<sub>4</sub><sup>+</sup> IR band was measured after just 1 day of being exposed to vacuum conditions.</p> <p>Acknowledgments</p> <p>This work was supported by the Spanish MINECO projects ESP2017-89053-C2-1-P and PID2019-107442RB-C32, and the AEI project MDM‐2017‐0737 Unidad de Excelencia “María de Maeztu”.</p> <p>References</p> <p>[1] De Sanctis et al.,  Space Sci. Rev. 216, 60, 2020</p> <p>[2] Raponi et al., Icarus 320, 83,  2019</p> <p>[3] Borden and Giese, Clays Clay Miner. 49, 444, 2001</p> <p>[4] Mateo-Marti et al., Life 9, 72, 2019</p>

scholarly journals Bromatological and Microbiological Characterization of Andean Tubers Mashwa (Tropaeolum Tuberosum) and Oca (Oxalis Tuberosa)

2021 ◽  
Author(s):  
Cristian José Esparza Bonilla ◽  
Cesar Iván ◽  
Flores Mancheno ◽  
Tatiana Elizabeth Sánchez Herrera
Keyword(s):  
Factor Analysis ◽  
Analysis Of Variance ◽  
Aerobic Bacteria ◽  
Oxalis Tuberosa ◽  
Tropaeolum Tuberosum

The objective of this research was to analyze the bromatological and microbiological composition of Andean tubers, to determine whether their state of maturation influences their composition. Mashwa (Tropaeolum tuberosum) and oca (Oxalis tuberosa) tubers were analyzed. Different degrees of maturation (tender, ripe) were considered. In each analysis, three treatments were carried out, using 100g of sample. The data were analyzed through a two-factor analysis of variance with several samples per group. The average values obtained from the bromatological data of tender mashwa were: 12.33% protein, 0.87% fat, 5.17% ash and 6.41% moisture. The values for mature mashwa were: 15.27% protein, 1.00% fat, 6.74% ash and 5.85% moisture. For tender oca, the values were: 7.47% protein, 0.65% fat, 4.59% ash and 7.03% moisture. Finally, the values for mature oca were 8.92% protein, 0.64% fat, 5.40% ash and 6.03% moisture. In terms of the microbiological evaluation, a minimal presence of the following aerobic bacteria was observed: Stapylococus aureos, coliforms, Eschericha coli. The results showed that the microbiological values ​​for Andean tubers (mashwa and oca) were within the safe parameters, so the tubers are suitable for consumption. Keywords: bromatological, microbiological, Tropaeolum tuberosum, Oxalis tuberosa, maturation. RESUMEN El objetivo de esta investigación fue analizar la composición bromatológica, microbiológica, y determinar si el estado de maduración influye en la composición de los tubérculos andinos. Los tubérculos analizados, mashwa (Tropaeolum tuberosum) y oca (Oxalis tuberosa), donde se considero diferentes grados de maduración (tierno, maduro), en cada análisis se empleo 3 tratamientos utilizando 100g de muestra. Los datos fueron analizados mediante el programa Excel con un análisis de varianza de dos factores con varias muestras por grupo. El promedio obtenido en los datos bromatológicos de mashwa tierna son: proteína de 12,33%, grasa 0,87%, ceniza 5,17% y humedad 6,41%, mashwa madura 15,27% de proteína, 1,00% de grasa, 6,74% de ceniza y 5,85% de humedad, para la oca tierna en proteína de 7,47%, grasa 0,65%, ceniza 4,59% y humedad 7,03%, oca madura son de 8,92% de proteína, 0,64% de grasa, 5,40% de ceniza y 6,03% de humedad. En el caso de la evaluación microbiológica se observó la presencia mínima de Bacterias Aerobias, Stapylococus Áureos, Coliformes, Eschericha Coli. Determinando que los valores microbiológicos para los tubérculos andinos (mashwa, oca) se encuentran dentro de los parámetros por lo que están libres de patógenos y son aptos para el consumo. Palabras claves: bromatológico, microbiológico, Tropaeolum tuberosum, Oxalis tuberosa, maduración.

Evaluation of Sunflower (Helianthus annuus L.) Hybrids Using Multivariate Statistical Analysis

Helia ◽  
2015 ◽  
Vol 38 (63) ◽  
pp. 175-187
Author(s):  
Natalija Markova Ruzdik ◽  
Ilija Karov ◽  
Sasa Mitrev ◽  
Biljana Gjorgjieva ◽  
Biljana Kovacevik ◽  
...  
Keyword(s):  
Seed Yield ◽  
Environmental Conditions ◽  
Agronomic Traits ◽  
Block Design ◽  
Principal Component ◽  
Original Data ◽  
Research Field ◽  
Multivariate Statistical ◽  
Main Components

AbstractEvaluation and characterization of sunflower hybrids using morphological, physiological and biochemical data are necessary and essential in sunflower breeding programs. The aim of this paper was to evaluate the productive possibilities of some sunflower hybrids grown in Macedonian environmental conditions. The experiment was carried out during the period 2013 and 2014 on the research field of the Faculty of Agriculture, “Goce Delchev” University – Shtip, in Ovche Pole locality, Republic of Macedonia. Total 20 sunflower hybrids were used as an experimental material. The trial was arranged as randomized complete block design (RCBD) with three replications. The average content of oil and oleic acid were 45.6 and 65.2%, respectively. The highest seed yield from all sunflower hybrids was obtained for the hybrid NLK12M144 (3,344 kg ha–1) and the lowest for hybrid NLK12S126 (2,244 kg ha–1). Cluster analysis classified the sunflower hybrids into four groups based on agronomic traits and seed yield. Most of the hybrids were included in cluster I and III (7 hybrids) followed by cluster IV. Using principal component analysis two main components have been extracted, with eigenvalue greater than one. They account for 72.99% of the variability in the original data. Only four hybrids had positive values for both main components (NLK12M144, NLK12S070, NLK12S125 and NLN12N011 DMR). The results from this study can be used to identify the best sunflower hybrids grown under Macedonian environmental conditions and to select the superior hybrids for future exploitation.

Characterization of Deoxyribonucleic Acid (DNA) Obtained from Teeth Subjected to Various Environmental Conditions

1991 ◽  
Vol 36 (4) ◽  
pp. 13113J ◽  
Author(s):  
Ted R. Schwartz ◽  
Elayne A. Schwartz ◽  
Laura Mieszerski ◽  
Lorah McNally ◽  
Lawrence Kobilinsky
Keyword(s):  
Environmental Conditions ◽  
Deoxyribonucleic Acid

scholarly journals Initiation of Biofilm Formation byPseudomonas aeruginosa 57RP Correlates with Emergence of Hyperpiliated and Highly Adherent Phenotypic Variants Deficient in Swimming, Swarming, and Twitching Motilities

2001 ◽  
Vol 183 (4) ◽  
pp. 1195-1204 ◽  
Author(s):  
Eric Déziel ◽  
Yves Comeau ◽  
Richard Villemur
Keyword(s):  
Environmental Conditions ◽  
Phase Variation ◽  
Growth Conditions ◽  
Phenotypic Traits ◽  
Liquid Cultures ◽  
Environmental Bacterium ◽  
Type Iv ◽  
Large Colony ◽  
Small Colony

ABSTRACT Pseudomonas aeruginosa is a ubiquitous environmental bacterium capable of forming biofilms on surfaces as a survival strategy. It exhibits a large variety of competition/virulence factors, such as three types of motilities: flagellum-mediated swimming, flagellum-mediated swarming, and type IV pilus-mediated twitching. A strategy frequently used by bacteria to survive changing environmental conditions is to create a phenotypically heterogeneous population by a mechanism called phase variation. In this report, we describe the characterization of phenotypic variants forming small, rough colonies that spontaneously emerged when P. aeruginosa 57RP was cultivated as a biofilm or in static liquid cultures. These small-colony (S) variants produced abundant type IV fimbriae, displayed defective swimming, swarming, and twitching motilities, and were impaired in chemotaxis. They also autoaggregated in liquid cultures and rapidly initiated the formation of strongly adherent biofilms. In contrast, the large-colony variant (parent form) was poorly adherent, homogeneously dispersed in liquid cultures, and produced scant polar fimbriae. Further analysis of the S variants demonstrated differences in a variety of other phenotypic traits, including increased production of pyocyanin and pyoverdine and reduced elastase activity. Under appropriate growth conditions, cells of each phenotype switched to the other phenotype at a fairly high frequency. We conclude that these S variants resulted from phase variation and were selectively enriched when P. aeruginosa 57RP was grown as a biofilm or in static liquid cultures. We propose that phase variation ensures the prior presence of phenotypic forms well adapted to initiate the formation of a biofilm as soon as environmental conditions are favorable.

Sign in / Sign up

Export Citation Format

Share Document