scholarly journals The effect of sugar concentration on yeast growth associated with floral nectar and honey

2021 ◽  
Vol 52 ◽  
pp. e1288
Author(s):  
César Canché-Collí ◽  
Felipe Barahona ◽  
Luis A. Medina-Medina ◽  
Azucena Canto

Background: Floral nectar and honey vary in sugar concentration, from low concentration in nectar to high concentration in honey. Variation in sugar concentration is a gradient that determines yeast growth and can lead to its ecological niche specialization. Objective: Evaluate the effect of a sugar concentration gradient on the growth kinetics and cell size of yeasts isolated from the floral nectar and honey of Melipona beecheii. Methods: Four strains identified as Metschnikowia koreensis and Sympodiomycopsis paphiopedili, isolated from floral nectar, and Starmerella apicola and Starmerella apicola 2, isolated from honey of Melipona beecheii were grown in artificial media with a gradient of 2, 10, 20, 40 and 60% glucose. We evaluated culture density (cells / µL), growth parameters, and cell size in each strain. Results and Conclusions: Strains isolated from honey had high growth rates at the highest glucose concentrations, while strains isolated from floral nectar grew best at low concentrations. Cell size decreased as glucose concentration increased in all strains. The data supports the hypothesis that sugar concentration gradient is an ecological filter that modifies the growth and morphology of yeasts associated with flowers and honey and leads to niche specialization in yeasts that colonize plant-bee environments.

Author(s):  
Kandhan Karthishwaran ◽  
Annadurai Senthilkumar ◽  
Wasef Ayed Alzayadneh ◽  
Mohammed Abdul Mohsen Alyafei

Date palm (Phoenix dactylifera L.) is a major plant grown under natural conditions in the Middle East and is subject to multiple environmental stresses. Increased concentration of atmospheric carbon dioxide (CO2) and ultraviolet-B (UV-B) irradiation in the growth environment can have a high impact on plant carbon accumulation, and the various factors can function in opposite directions or cause additive effects. The objective of the present investigation was to screen UAE date palm for susceptibility to elevated level of CO2, UVB and their combined effect on a date palm variety was assessed in transparent open - top chambers (OTC) conditions in the hot climate of UAE. After the screening of the cultivars, experiment was conducted in an OTC facility and the treatments were given for 120 days. After the treatment of the selected cultivar, content of chlorophyll a, b and total, carotenoids, protein, amino acids, phenol and activities including γ-glutamyl kinase, proline oxidase, a-tocopherol and peroxidases activity were determined. The results revealed that the high concentration of CO2 alone increased the growth parameters, whereas the treatment with UV-B significantly affected the growth of the plant relative to regulation. Enzyme observations have shown that an increase in antioxidant enzymes can affect a defense response to the abiotic stress-induced cellular damage. Further extension of this study with other cultivated varieties, other stress parameters and determination of yield parameters will give scope to identify new stress tolerant cultivars of date palm trees.


2019 ◽  
Vol 32 ◽  
pp. 282-290
Author(s):  
Nada A. El-Qatrani

This study was carried out in the nursery of Department of Horticulture and Landscape Design, College of Agriculture, University of Basrah during 2018 growing season. Completely randomized blocks design (C.R.B.D.)  was used to investigate the effect of different concentrations of super swing (0, 0.5 and 1) g.l-1 and whey (0, 50 and 75) % and their interactions to enhance the growth parameters and chemical characteristics of Sour orange transplants. The results showed a significant increase in most of the measured growth parameters of transplants treated with high concentration of foliar spraying to both fertilizers. Application of super swing at 1 g.l-1 with whey at 75% together significantly increased the height of plant, the number of leaves, leaf area, the diameter of stem, number of flowers, the leaves content of both nitrogen and potassium, percentage of dry matter, and content of chlorophyll. Whereas, control treatment was significantly increased the water content compared to other treatments. Addition of growth-enhancing compounds such as super swing and whey extract to the plant can improve the metabolic performance and enhances the plant's ability to absorb nutrients from the soil.


2020 ◽  
Vol 11 (1) ◽  
pp. 7735-7745

Biotechnology is considered one of the most influential technologies in various areas of human life, including health, economics, and the environment. Protein engineering is one of the major biotechnology tools in the field of modification and advancement of biocatalysts capabilities. Among the most effective protein engineering methods, in particular, to improve the industrial strain capabilities, is the shuffling genome method. This study aimed to follow knowledge and biocatalysts engineering techniques based on DNA shuffling methods. In the first step, two procedures were followed (DES method and compatibility according to the concentration gradient of Diazinon) to obtain mutant strains. Acquired mutant strains from both methods were resistant to high concentrations of poison up to 3000 mg/L. The activity of these strains also demonstrated their elevated activity compared to parent samples. The highest activity was related to four strains IR1.G1, IR1.D8, IR1.D4, and IR1.D5, which were 0.234 U/ml, 0.1 U/ml, 0.098 U/ml, and 0.066 U/ml, respectively. The improved strain was obtained via the concentration gradient of the diazinon method (IRL1.G1 strain) in comparison with IRL1.D8 strain (owning highest activity through DES method) possesses excessive activity in 3000 mg/L concentration of Diazinon. The evaluated results of first-generation genome shuffling of strains (the first round of protoplast fusion) also indicated that those shuffled strains with the ability to grow in the vicinity of the toxin (3000 mg/L concentration of Diazinon) showed better activity than obtained mutated strains by both methods (concentration gradient of the toxin and the DES method). In the final stage, the best results were related to IRL1.F2, IRL1.F3, and IRL1.F1 shuffled strains with 0.541 mg/L, 0.523 mg/L, and 0.509 mg/L, respectively. The highest activity belonged to the IRL1.F2 genome shuffled strain (first round of protoplast fusion). This strain could grow in a high concentration of toxin, and also, the activity was increased 30, 3.6, and 2.3 times in comparison with the parent strain (IRL1), IRL.D8 mutant, and IRL1.G1, respectively.


Foods ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1048 ◽  
Author(s):  
Corinne Eicher ◽  
Andres Ruiz Subira ◽  
Sabrina Corti ◽  
Arnulf Meusburger ◽  
Roger Stephan ◽  
...  

Cold smoked salmon and sushi salmon have been implicated in outbreaks of listeriosis. We performed challenge tests and a durability study with Listeria monocytogenes on different salmon products to determine the growth potential of this important food-borne pathogen. Data from the challenge test showed a significant growth potential of L. monocytogenes on all of the tested salmon products, with faster growth in sushi salmon than in cold smoked salmon. In identical products that were naturally contaminated at low levels, the durability study did not confirm a high growth potential, possibly due to interactions with competing microflora. The injection of sodium lactate (NaL) at a high concentration (30%) into cold smoked salmon significantly reduced the growth potential of L. monocytogenes. In addition to good manufacturing practices, the injection of higher concentrations of NaL may therefore be a useful additional hurdle to prevent growth of L. monocytogenes to high numbers in the tested salmon products.


1994 ◽  
Vol 29 (7) ◽  
pp. 119-128 ◽  
Author(s):  
C. H. Ratsak ◽  
B. W. Kooi ◽  
H. W. van Verseveld

The currently high sludge production and increasing processing costs call for waste-water treatment plants with high purification efficiency and low biomass production. We studied the latter issue through two-stage chemostat cascades to assess the overall biomass reduction due to ciliate grazing. The bacteria were cultured in the first chemostat whereas the ciliates, grazing on the bacteria from the first chemostat, were cultured in the second chemostat. Mathematical modelling was used to describe the bacteria/ciliate dynamics and some of the growth parameters were fitted. In the second chemostat 22-44% of the carbon originating from the first chemostat was mineralized to CO2. An extra biomass reduction of 12-43% was possible due to grazing by the ciliates. At lower growth rates of the ciliates the extra biomass reduction was higher than at high growth rates. This finding is auspicious, suggesting that predator organisms indeed can reduce sludge production.


Metabolites ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 58 ◽  
Author(s):  
Nara Regina Brandão Cônsolo ◽  
Juliana da Silva ◽  
Vicente Luiz Macedo Buarque ◽  
Angel Higuera-Padilla ◽  
Luis Carlos Garibaldi Simon Barbosa ◽  
...  

To clarify the relationship between beef genetic selection for growth and precocity with muscle metabolism and metabolites, we performed metabolomic analysis using Longissimus lumborum (LL) muscle from Nellore cattle with divergent selection for these traits (high growth, HG; low growth, LG; high precocity, HP; low precocity, LP). Genetic potential for growth affected muscle protein and energetic metabolism. HG animals had a high concentration of arginine, carnosine, and leucine compared to LG animals. HP animals presented a high concentration of glutamine, betaine, creatinine, isoleucine, carnitine, acetyl carnitine, and lower levels of glucose compared to LP animals, affecting protein and fatty acid metabolism. Intensity of selection (high or low) was correlated with changes in protein metabolism, and the type of selection (growth or precocity) affected fat metabolism. In conclusion, both HG and HP appear to be correlated with a high concentration of protein metabolites and changes in protein metabolic pathways, while selection for precocity is more correlated with changes in fat metabolism compared to animals selected for growth.


2014 ◽  
Vol 40 (2) ◽  
pp. 81-89 ◽  
Author(s):  
Hanane Sayel ◽  
Nezha Tahri Joutey ◽  
Wifak Bahafid ◽  
Naima El Ghachtouli

Abstract Three chromium resistant bacterial strains, Pseudomonas fluorescens PF28, Enterobacter amnigenus EA31 and Enterococcus gallinarum S34 isolated from tannery waste contaminated soil were used in this study. All strains could resist a high concentration of K2Cr2O7 that is up to 300 mg/L. The effect of these strains on clover plants (Trifolium campestre) in the presence of two chromium salts CrCl3 and K2Cr2O7 was studied in soil microcosm. Application of chromium salts adversely affected seed germination, root and shoot length. Bacterial inoculation improved the growth parameters under chromate stress when compared with non inoculated respective controls. There was observed more than 50% reduction of Cr(VI) in inoculated soil microcosms, as compared to the uninoculated soil under the same conditions. The results obtained in this study are significant for the bioremediation of chromate pollution.


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