scholarly journals The Effect of Gibberellic Acid on the Production Characteristics and Biochemical Parameters of Tetraselmis Suecica in an Enrichment Culture

2022 ◽  
Author(s):  
Nikolai Nikolaevich Kovalev ◽  
Svetlana Yevgenyevna Leskova ◽  
Yevgeny Valeryevich Mikheev ◽  
Yulia Mikhailovna Pozdnyakova ◽  
Roman Vladimirovich Esipenko

The use of gibberellic acid as a stimulator of microalgae growth has beensubstantiatedexperimentally.This research aimed to assess the effect of exposure to a wide range of gibberellic acid concentrations on the growth dynamics ofthe microalgaTetraselmissuecicain an enrichment culture. The duration of the experiments was 14 days. It has been shown that gibberellic acid,atconcentrations of 0.39–3.20× 10−8M, stimulates algaegrowth. In this research, the exposure to gibberellic acid at concentrations of 0.39–3.20 × 10−8M was accompanied by a variation in the pattern of growth curves: the maximum number of cells was recorded on day seven of the experiment. A higher concentration of the phytohormone (3.84 × 10−8М) inhibited the increase inculture density. The growth of theT. suecicaculture in the control group was 332%;the growth of the culture exposed to gibberellic acid at a concentration of 0.39 × 10−8M was1136%. The values of the specific growth rate ofT. suecicawere estimated for different periods of cultivation. On day14 of the experiment, the biochemical composition of microalgae biomass was analyzed.According to the results, gibberellic acid stimulated the accumulation of carbohydrates, proteins, and chlorophyll. Nevertheless, the phytohormone had no effect on lipidaccumulation. An assumption was made thatexposure to low concentrations of phytohormone stimulates the growth of microalgae by reducing the lag phase of growth. Keywords: gibberellic acid, microalga, cultivation, lipids, carbohydrates, proteins

Author(s):  
Nikolai Nikolayevich Kovalev ◽  
Svetlana Evgenyevna Leskova ◽  
Evgeny Valerevich Mikheev ◽  
Yuliya Mihaylovna Pozdnyakova ◽  
Roman Vladimirovich Esipenko

The article considers the use of salicylic acid as a stimulator of microalgae growth. The influence of a wide range of salicylic acid concentrations on the growth dynamics of Tetra-selmis suecica in enrichment culture has been evaluated. Cultivation was carried out in monoculture. An increase in algal biomass was measured by the increasing number of cells counted in each experiment in three Goryaev chambers under a light microscope. The duration of the experiments was 14 days. It is shown that salicylic acid in concentrations of 0.4-1.9 • 10–5 M inhibits the growth of algae. The growth of the control culture has two pronounced peak numbers on 4th and 12th days of the experiment. The introduction of salicylic acid in concentrations of 0.44-1.9 • 10–5 M was accompanied by a change of the growth curves: the maximum number of cells was observed on 12th day of the experiment. A higher concentration of phytohormone (3.75.• 10–5 M) provided an increase in crop density by 414% over 14 days of the experiment. The growth of T. suecica culture in the control group was 332%. The values of the specific growth rate of T. suecica were calculated for different periods of cultivation. After 14 days of the experiment, the biochemical composition of the microalgae biomass was evaluated, which showed stimulation with salicylic acid at a con-centration of 3.75 • 10–5 M carbohydrate accumulation. The high concentration of phytohormone suppressed the accumulation of protein, lipids and chlorophyll in the culture and stimulated the accumulation of carbohydrates. It has been suggested that a possible mechanism for the multidirectional action of salicylic acid is its effect on synthesis and catabolism through inhibition of the synthesis and metabolism of endogenous plant hormones.


2016 ◽  
Vol 1 (2) ◽  
pp. 63 ◽  
Author(s):  
Ji-Dong Gu

Bacterial growth is a very important piece of information in a wide range of investigation and, in most of the time the data are simply shown directly without any further processing. In a single factor investigation without comparative information to be extracted, this simple approach can be used together with other data to form a comprehensive set of results. When comparison is involved, such direct showing of bacterial growth curves without processing cannot warrant a meaningful comparison thoroughly and further processing of data is necessary. In addition, there is little, if any, quantitative data for the comparison from the display of growth curves and description of a number of curves is not a simple task, especially in a meaningful way for assimilation of the data to readers. With this in mind, I would like to remind of those who plan to show such data as growth curves for their potential publication to carry this further to generate comparative results for a much meaningful interpretation by modeling and calculation from the raw growth data over time of incubation. By calculating with existing equations, the lag phase, growth rate and the biomass can be derived from a series of growth curves for a more effective and meaningful analysis. This approach is not new, but remembrance of such available tool is more important so that research data are shown professionally and also scientifically for meaning presentation and effective assimilation.


Author(s):  
V. I. Ipatova ◽  
A. G. Dmitrieva ◽  
О. F. Filenko ◽  
T. V. Drozdenko

The structure of the laboratory population of green microalgae Scenedesmus quadricauda (Turp.) Breb (=Desmodesmus communis E. Hegew.) was studied at different stages of its growth (lag-phase, log-phase and stationary phase) at low concentrations of copper chloride and silver nitrate by the method microculture, allowing to monitor the state and development of single cells having different physiological status. The response of the culture of S. quadricauda - the change in the number of cells and the fractional composition (the fraction of dividing, «dormant» and dying cells) depended not only on the concentration of the toxicant in the medium, but also on the physiological state of the culture: the level of synchronization and the growth phase. Silver ions at low concentrations had a more pronounced toxic effect on the culture than copper ions at different phases of its development, especially at a concentration of 0.001 mg/l (10-9 M). The main mechanism of the toxic effect of metals is to inhibit the process of cell division. At low concentrations of toxicants, especially at a concentration of 0.001 mg/l, a «paradoxical» effect expressed in the predominance of the fraction of «dormant» cells was revealed. The temporary inhibition of the process of cell division can be regarded as a protective mechanism that allows preserving the integrity of the population and its ability to survive in a changing environment. The obtained data explain the effect of action of low concentrations of substances due to their inclusion in the cell, the subsequent accumulation in the cell and their low excretion.


2019 ◽  
Vol 26 (10) ◽  
pp. 720-742 ◽  
Author(s):  
Kaushik Das ◽  
Karabi Datta ◽  
Subhasis Karmakar ◽  
Swapan K. Datta

Antimicrobial Peptides (AMPs) have diverse structures, varied modes of actions, and can inhibit the growth of a wide range of pathogens at low concentrations. Plants are constantly under attack by a wide range of phytopathogens causing massive yield losses worldwide. To combat these pathogens, nature has armed plants with a battery of defense responses including Antimicrobial Peptides (AMPs). These peptides form a vital component of the two-tier plant defense system. They are constitutively expressed as part of the pre-existing first line of defense against pathogen entry. When a pathogen overcomes this barrier, it faces the inducible defense system, which responds to specific molecular or effector patterns by launching an arsenal of defense responses including the production of AMPs. This review emphasizes the structural and functional aspects of different plant-derived AMPs, their homology with AMPs from other organisms, and how their biotechnological potential could generate durable resistance in a wide range of crops against different classes of phytopathogens in an environmentally friendly way without phenotypic cost.


2020 ◽  
Vol 16 (4) ◽  
pp. 537-542
Author(s):  
Zhigacheva Irina ◽  
Volodkin Aleksandr ◽  
Rasulov Maksud

Background: One of the main sources of ROS in stress conditions is the mitochondria. Excessive generation of ROS leads to oxidation of thiol groups of proteins, peroxidation of membrane lipids and swelling of the mitochondria. In this regard, there is a need to search for preparationsadaptogens that increase the body's resistance to stress factors. Perhaps, antioxidants can serve as such adaptogens. This work aims at studying the effect of antioxidant; the potassium anphen in a wide range of concentrations on the functional state of 6 day etiolated pea seedlings mitochondria (Pisum sativum L). Methods: The functional state of mitochondria was studied per rates of mitochondria respiration, by the level of lipid peroxidation and study of fatty acid composition of mitochondrial membranes by chromatography technique. Results: Potassium anphen in concentrations of 10-5 - 10-8 M and 10-13-10-16 prevented the activation of LPO in the mitochondrial membranes of pea seedlings, increased the oxidation rates of NAD-dependent substrates and succinate in the respiratory chain of mitochondria that probably pointed to the anti-stress properties of the drug. Indeed, the treatment of pea seeds with the preparation in concentrations of 10-13 M prevented the inhibition of growth of seedlings in conditions of water deficiency. Conclusion: It is assumed that the dose dependence of the biological effects of potassium anphen and the manifestation of these effects in ultra-low concentrations are due to its ability in water solutions to form a hydrate containing molecular ensembles (structures).


Lupus ◽  
2020 ◽  
Vol 29 (2) ◽  
pp. 182-190
Author(s):  
W Batista Cicarini ◽  
R C Figueiredo Duarte ◽  
K Silvestre Ferreira ◽  
C de Mello Gomes Loures ◽  
R Vargas Consoli ◽  
...  

We have explored the relationship between possible hemostatic changes and clinical manifestation of the systemic lupus erythematosus (SLE) as a function of greater or lesser disease activity according to Systemic Lupus Erythematosus Disease Activity Index-2000 (SLEDAI-2K) criteria. Endothelial injury and hypercoagulability were investigated in patients with SLE by measuring thrombomodulin (TM), D-dimer (DDi) and thrombin generation (TG) potential. A total of 90 participants were distributed into three groups: 1) women with SLE presenting with low disease activity (laSLE) (SLEDAI-2K ≤ 4), 2) women with SLE presenting with moderate to high disease activity (mhaSLE) (SLEDAI-2K > 4), and 3) a control group comprising healthy women. Levels of TM and DDi were higher both in the laSLE and mhaSLE groups compared to controls and in mhaSLE compared to the laSLE group. With respect to TG assay, lagtime and endogen thrombin potential, low concentrations of tissue factor provided the best results for discrimination among groups. Analysis of these data allow us to conclude that TM, DDi and TG are potentially useful markers for discriminating patients with very active from those with lower active disease. Higher SLE activity may cause endothelial injury, resulting in higher TG and consequently a hypercoagulability state underlying the picture of thrombosis common in this inflammatory disease.


2021 ◽  
Vol 13 (15) ◽  
pp. 8620
Author(s):  
Sanaz Salehi ◽  
Kourosh Abdollahi ◽  
Reza Panahi ◽  
Nejat Rahmanian ◽  
Mozaffar Shakeri ◽  
...  

Phenol and its derivatives are hazardous, teratogenic and mutagenic, and have gained significant attention in recent years due to their high toxicity even at low concentrations. Phenolic compounds appear in petroleum refinery wastewater from several sources, such as the neutralized spent caustic waste streams, the tank water drain, the desalter effluent and the production unit. Therefore, effective treatments of such wastewaters are crucial. Conventional techniques used to treat these wastewaters pose several drawbacks, such as incomplete or low efficient removal of phenols. Recently, biocatalysts have attracted much attention for the sustainable and effective removal of toxic chemicals like phenols from wastewaters. The advantages of biocatalytic processes over the conventional treatment methods are their ability to operate over a wide range of operating conditions, low consumption of oxidants, simpler process control, and no delays or shock loading effects associated with the start-up/shutdown of the plant. Among different biocatalysts, oxidoreductases (i.e., tyrosinase, laccase and horseradish peroxidase) are known as green catalysts with massive potentialities to sustainably tackle phenolic contaminants of high concerns. Such enzymes mainly catalyze the o-hydroxylation of a broad spectrum of environmentally related contaminants into their corresponding o-diphenols. This review covers the latest advancement regarding the exploitation of these enzymes for sustainable oxidation of phenolic compounds in wastewater, and suggests a way forward.


Medicina ◽  
2021 ◽  
Vol 57 (2) ◽  
pp. 122
Author(s):  
Marta Pérez-Rodríguez ◽  
Saleky García-Gómez ◽  
Javier Coterón ◽  
Juan José García-Hernández ◽  
Javier Pérez-Tejero

Background and objectives: Acquired brain injury (ABI) is the first cause of disability and physical activity (PA) is a key element in functional recovery and health-related quality of life (HRQoL) during the subacute and chronic phases. However, it is necessary to develop PA programs that respond to the heterogeneity and needs of this population. The aim of this study was to assess the effectiveness of a PA program on the HRQoL in this population. Materials and Methods: With regard to recruitment, after baseline evaluations, participants were assigned to either the intervention group (IG, n = 38) or the control group (CG, n = 35). Functional capacity, mood, quality of life and depression were measured pre- and post-intervention. The IG underwent the “Physical Activity and Sport for Acquired Brain Injury” (PASABI) program, which was designed to improve HRQoL (1-h sessions, two to four sessions/week for 18 weeks). The CG underwent a standard rehabilitation program without PA. Results: Results for the IG indicated significant differences and large effect sizes for the physical and mental dimensions of quality of life, as well as mood and functional capacity, indicating an increase in HRQoL. No significant differences were found for the CG across any variables. Conclusions: The PASABI program was feasible and beneficial for improving physiological and functionality variables in the IG. The wide range of the activities of the PASABI program allow its application to a large number of people with ABI, promoting health through PA, especially in the chronic phase.


Author(s):  
Magdalena Mijas ◽  
Karolina Koziara ◽  
Andrzej Galbarczyk ◽  
Grazyna Jasienska

A risk of cardiovascular disease (CVD) is increased by multiple factors including psychosocial stress and health behaviors. Sexual minority men who identify as Bears form a subculture distinguished by characteristics associated with increased CVD risk such as elevated stress and high body weight. However, none of the previous studies comprehensively investigated CVD risk in this population. Our study compared Bears (N = 31) with other gay men (N = 105) across a wide range of CVD risk factors. Logistic regression and analysis of covariance (ANCOVA) models were performed to compare both groups concerning behavioral (e.g., physical activity), medical (e.g., self-reported hypertension), and psychosocial (e.g., depressiveness) CVD risk factors. Bears were characterized by older age and higher body mass index (BMI) than the control group. We also observed higher resilience, self-esteem, as well as greater prevalence of self-reported hypertension, diabetes, and hypercholesterolemia in Bears. None of these differences remained statistically significant after adjusting for age and, in the case of self-reported diagnosis of diabetes, both age and BMI. Our study demonstrates that Bears are characterized by increased CVD risk associated predominantly with older age and higher BMI. Health promotion interventions addressed to this community should be tailored to Bears’ subcultural norms and should encourage a healthier lifestyle instead of weight loss.


Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 355
Author(s):  
Unai Caballero ◽  
Sarah Kim ◽  
Elena Eraso ◽  
Guillermo Quindós ◽  
Valvanera Vozmediano ◽  
...  

Candida auris is an emergent fungal pathogen that causes severe infectious outbreaks globally. The public health concern when dealing with this pathogen is mainly due to reduced susceptibility to current antifungal drugs. A valuable alternative to overcome this problem is to investigate the efficacy of combination therapy. The aim of this study was to determine the in vitro interactions of isavuconazole with echinocandins against C. auris. Interactions were determined using a checkerboard method, and absorbance data were analyzed with different approaches: the fractional inhibitory concentration index (FICI), Greco universal response surface approach, and Bliss interaction model. All models were in accordance and showed that combinations of isavuconazole with echinocandins resulted in an overall synergistic interaction. A wide range of concentrations within the therapeutic range were selected to perform time-kill curves. These confirmed that isavuconazole–echinocandin combinations were more effective than monotherapy regimens. Synergism and fungistatic activity were achieved with combinations that included isavuconazole in low concentrations (≥0.125 mg/L) and ≥1 mg/L of echinocandin. Time-kill curves revealed that once synergy was achieved, combinations of higher drug concentrations did not improve the antifungal activity. This work launches promising results regarding the combination of isavuconazole with echinocandins for the treatment of C. auris infections.


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