Effects Of Temperature Stress Research Articles

Boron bio-mining by high boron-tolerant native microalgae in Turkey and boron toxicity in the aquatic environment.

Boron (B) is one of the most important trace elements. Turkey has the largest B reserves in the world with 3 billion tons of B. Therefore, the toxicity of B is more important in Turkey. In this study, effective B removal was provided by different types of microalgae and then B recovery in culture media by bio-mining was detected. The water of Lake Mogan in Gölbaşı/Ankara/Turkey was used as the microalgae culture medium as a cost-reducing factor. The effects of light, temperature, NaNO3 and K2HPO4 stresses on B removal were determined. The highest B removal was 17.19% at 25 μmol/m2s light intensity and 25 °C for Phormidium animale in Lake Mogan culture medium. Boron removal of Scenedesmus sp. was 36.42% at 25 μmol/m2s light intensity, at 25 °C, at 1.5 g/L NaNO3 and 40 mg/L K2HPO4 concentrations in BG11 medium on the 15th day. The chl (a + b) concentration of Scenedesmus sp. was 1.63 μg/mL at 75 μmol/m2s light intensity and the chl (a) concentration of P. animale was 2.01 μg/mL at 25 μmol/m2s light intensity. Considering all parameters, Scenedesmus sp. and P. animale are recommended as effective biomaterials for the B removal process.

Effects of temperature and DC cycling stress on resistive switching mechanisms in hafnia-based ferroelectric tunnel junction

We propose an accurate and effective method, low-frequency noise (LFN) spectroscopy, to examine the resistive switching mechanism in ferroelectric tunnel junctions (FTJs) based on pure hafnium oxide (HfOx). Contrary to previous studies that primarily focused on the ferroelectric (FE) resistive switching (RS) in HfOx-based FTJs, the results of this study demonstrate that non-FE RS affected by the redistribution of oxygen vacancies also plays a significant role in determining the performance of FTJs. LFN spectroscopy is conducted in different conditions by changing the operating temperature and inducing DC cycling stress. The results reveal that the RS mechanism changes from FE to non-FE RS with increased program bias in all conditions. This change is facilitated by the rise in temperature and the number of DC cycling stress.

Individual and Interactive Ecophysiological Effect of Temperature, Watering Regime and Abscisic Acid on the Growth and Development of Tomato Seedlings

Climate change is a major concern to people all over the world. Most studies have considered singular or dual effects of climate change implications on plant growth and development; however, the combination of multiple factors has received little attention. We therefore studied the single and combined effects of two environmental stress factors (high temperature and water stresses) and abscisic acid on tomato seedlings (Solanum lycoperscum L.). Plants were grown in controlled environment growth chambers under two temperatures (22/18 °C or 28/24 °C; 16 h light/8 h dark), two watering regimes (well-watered or water-stressed), and two abscisic acid treatments (0 and 100 µL of 1mM abscisic acid solution, every other day). Plants were placed under experimental conditions for a total of 33 days, including a 13-day period of initial growth and hardening. Morphological, biochemical, and physiological parameters were measured to assess the growth and development of plants in response to the three factors. ANOVA and Scheffé’s multiple-comparison procedures were used to establish significant differences among treatments and among the three factors being manipulated. All three factors decreased plant height and growth rate. Dry mass accumulation was negatively affected by high temperatures. Transpiration, stomatal conductance, and gas exchange parameters were negatively affected by all three factors; additionally, net carbon dioxide assimilation was reduced by water stress and abscisic acid application. Non-photochemical quenching was decreased in plants grown under higher temperature and in abscisic acid-treated plants. Though it was not significant, abscisic acid appears to mitigate the negative effect of higher temperature and water stress on the nitrogen balance index and total chlorophyll content.

The protective effect of resveratrol on largemouth bass (Micropterus salmoides) during out-of-season spawning

In aquaculture production, out-of-season spawning is beneficial to solve the seasonal shortage of fry that are normally produced once annually by species such as largemouth bass (Micropterus salmoides), thereby implementing year-round fry production. Maintaining low temperature over a period of several months can delay largemouth bass ovarian development, but it can cause severe stress to their reproductive function, leading to decreased fertility during out-of-season spawning. Feeding with antioxidants is one of the most effective methods to alleviate the negative effects of low temperature stress. Therefore, the purpose of this study is to: (a) evaluate the changes in oocyte morphology, antioxidant capacity, reproductive hormone-related index, cell apoptosis and autophagy during the out-of-season spawning of largemouth bass, and (b) to investigate the protective effect of the antioxidant resveratrol on this fish during out-of-season spawning from May through August. The study was divided into two groups (three replicates per group, 2000 fish per replicate): control group (Control) (exposure to water temperature of 12–17 °C) and resveratrol supplementation group (Res) (exposure to water temperature of 12–17 °C and fed with 200 mg/kg resveratrol). The results show that: (1) The serum hormones LH and E2 increased first and then remained unchanged, and the ovarian section showed that the ovary remained in stage IV. (2) In the process of off-season reproduction, a large number of follicles experienced follicular atresia, accompanied by endoplasmic reticulum expansion, nuclear chromatin condensation and mitochondrial swelling, which was relieved after feeding resveratrol. (3) Resveratrol decreased the ovarian ROS content and improved the activities of CAT and other antioxidant enzymes in the ovary and liver to some extent. (4) Resveratrol reduced the level of pro-apoptotic (Bax, Caspase3, Caspase8, Caspase9) and autophagy-related components (LC3-B, Beclin-1) while increasing the transcription level of anti-apoptotic (Bcl-2) factors. These findings suggest that resveratrol alleviates some adverse effects of largemouth bass during out-of-season spawning to some extent and provide a model for efficient and high-quality out-of-season spawning.

Discontinuous low temperature stress and plant growth regulators during the germination period promote roots growth in alfalfa (Medicago sativa L.)

In high-cold regions, alfalfa is susceptible to cold damage during the seed germination. The effects of discontinuous low temperature stress and plant growth regulators (PGRs) on alfalfa were studied in response to the high day/night temperature differentials in the area. The experiments included seed germination, seedling cold tolerance and plant recovery. Variable temperatures (VT) of 0 °C/15 °C, 5 °C/20 °C and 10 °C/25 °C were set and seeds were soaked with alginate oligosaccharides (AOS), brassinolide (BR) and diethyl aminoethyl hexanoate (DA-6) during the germination period. Parameters such as seed germination and mean germination time (MGT), phenylalanine ammonia-lyase (PAL) activity and oligomeric proanthocyanidins (OPC) content of early seedlings, dry matter accumulation and root crown of the restored plants were analysed. The results showed that low variable-temperature (LVT) stress prolonged the MGT but had little inhibitory effect on germination percentage. Early seedlings adapted to LVT stress by regulating their own water and OPC content, PAL activity and other parameters. LVT induced early alfalfa seedlings to increase their underground biomass by shortening root length and increasing root diameter, and those that had accumulated more underground biomass had faster growth rates and higher total biomass when the ambient temperature rose. AOS also promoted an increase in root crown diameter and root dry weight. This research proved that LVT stress and AOS during the germination process can lead to better growth of alfalfa in high cold regions.

The temperature-dependent shear strength of ice-filled joints in rock mass considering the effect of joint roughness, opening and shear rates

Abstract. Global warming causes many rockfall activities in alpine mountains, especially when ice-filled joints in the rock mass become thawed. The warming and thawing of frozen soils and intact rocks have been widely studied in the past several decades; however, the variation of shear strengths of ice-filled joints is not fully understood. In this study, a series of compression–shear experiments were conducted to investigate the shear strength of ice-filled rock joints by considering the effects of joint roughness, temperature, opening, shear rates and normal stress. The joint roughness can improve the shear strength of ice-filled joints. However, the contribution of joint roughness is controlled by some noticeable bulges instead of the joint roughness coefficient (JRC) index. The peak shear strength of the ice-filled joint linearly increases with the increasing aggregation of rupture ice area before these noticeable bulges. As the joint opening increases, the effect of joint roughness decreases, and the shear strength of ice-filled joints tends to be equal to the shear strength of pure ice. In addition, the shear strength quickly reduces with increasing temperature from −15 to −0.5 ∘C. The shear failure mode changes from shear cracking of joint ice to the shear debonding of the ice–rock interface above −1 ∘C. Increasing shear rate decreases the shear strength of ice-filled joints because the joint ice displays the brittle failure phenomenon at a high shear rate. The peak shear strength of the ice-filled joint linearly increases with the increase in normal stress. Moreover, it is also proved that the Mohr–Coulomb criterion can be used to characterize the shear strength of ice-filled joints under different normal stresses. This research can provide a better understanding of the warming degradation mechanism of ice-filled joints by considering the abovementioned important influencing factors.

Effects of Temperature and Water Stress on Leaf Growth and Flowering of Litchi (Litchi chinensis Sonn.)

Effects of Temperature and Water Stress on Leaf Growth and Flowering of Litchi (Litchi chinensis Sonn.)

Modeling effects of temperature, laminated structure, flaws and residual stress on fracture toughness of multilayered and particulate ceramic matrix composites

Considering that the ceramic matrix composites are frequently used in high-temperature applications, it is extremely important to analyze their fracture toughness at high temperatures. At present, there are still few systematic experimental and theoretical studies of temperature-dependent fracture toughness of particulate ceramic matrix composites, especially for the laminated composites. In this work, a series of novel theoretical models of the temperature-dependent fracture toughness of multilayered and particulate ceramic matrix composites containing different flaws are developed, by using the stress intensity factor method and the high-temperature fracture strength theory. The work considers the effects of internal and surface flaws, laminated structure and thermal residual stresses within particle and laminate, without the need for fitting to predict high-temperature fracture toughness. The predictions of all models show good agreements with measured data without any fitting parameters. This work provides the potentially efficient methods for obtaining high-temperature fracture toughness and fracture strength of both multilayered and particulate composites that uses only the elastic properties and specific heat capacity, avoiding the traditional destructive experiments such as bending test and single edge notched beam methods.

Seed germination requirements of Amaranthus retroflexus L. populations exposed to environmental factors

Seed germination studies are often used to predict the potential of plants to extend their global distribution. In this research, the effect of gibberellic acid (GA3) concentrations, pre-chilling, temperature, water and salt stresses, pH, high-temperature pretreatment, planting depth, and flooding on seed germination and seedling emergence of three Amaranthus retroflexus L. populations was investigated. GA3 concentration significantly affected seed germination of all three A. retroflexus populations grown under light/dark conditions. All three populations germinated under constant (10, 15, 20, 25, and 30 °C) and alternating (20/15, 25/18, and 35/25 °C (day/night)) temperatures. The optimum alternating temperature for germination of all three populations was 18/25 °C day/night. Seed germination was severely reduced under moisture and salt stresses. Seedling emergence was reduced on the soil surface by increasing the planting depth from 2.5 to 7.5 cm, and no seedlings emerged when the planting depth of seeds was more than 10 cm . The results of this research help us to understand the germination capacity and requirements of A. retroflexus in different environments and also provide information to help better control the weed.

Application of growth regulators-antistressors in complex with universal bioactive fertilizers in seed production of gourds

Relevance. The effectiveness of seed soaking before sowing in a solution of preparations of the epibrassinolide group for the protection and preservation of seedlings of gourds from temperature stresses, increasing the yield of fruits and seeds was studied.Methodology. The objects of research were preparations Epin Extra, Epin Plus, EcoFus, Ferovit, Zircon and Siliplant, which allow to overcome the effects of temperature stresses, increase immunity, and have a stimulating effect on seed germination and plant growth of vegetable crops.Results. In the course of the studies, it was found that preparations of the epibrassinolide group contribute to a significant preservation of seedlings of gourds with prolonged exposure to low temperatures. Soaking watermelon seeds of the Tersky early variety before sowing in a solution of drugs from the epibrassinolide group ensured the safety of seedlings from 24.2 to 35.3%, while in the control variant, the death of plants was 100%. Epin Extra had the greatest anti-stress effect on watermelon. Preparations on melon showed less efficiency in protecting seedlings, 21.1-27.3% of plants survived. The maximum number of seedlings remained when using Epin Plus. It should be noted that soaking seeds in solutions of preparations of the epibrassinolide group, to protect seedlings of gourds from damage by low temperatures, is an effective technological operation that makes it possible to smooth out the impact of the stress factor.

Effects of Temperature and Salt Stress on the Expression of delta-12 Fatty Acid Desaturase Genes and Fatty Acid Compositions in Safflower.

The regulation of microsomal (e.g., FAD2) and plastidial (e.g., FAD6) oleate desaturases by cold, heat and salt stress were investigated. Gene expression levels and fatty acid compositions were determined in the roots, stems and leaves of safflower following stress treatments. A safflower plastidial oleate desaturase gene, CtFAD6, was cloned, and oleic acid desaturation was confirmed in Synechococcus sp. strain PCC7942. The results showed that temperature regulated oleate desaturation at the transcriptional level, and this regulation pattern was tissue-specific. CtFAD2-1, CtFAD2-2 and CtFAD6 were significantly induced under cold and heat stress in young leaves, and CtFAD2-2 and CtFAD6 were slightly induced in young stems. In contrast, CtFAD2-1, CtFAD2-11 and CtFAD2-10 were sensitive to salt stress in all safflower tissues (roots, stem and leaves). CtFAD6 was insensitive to salt and was slightly induced in leaves only.

Perovskite Solar Cells in the Shadow: Understanding the Mechanism of Reverse‐Bias Behavior toward Suppressed Reverse‐Bias Breakdown and Reverse‐Bias Induced Degradation

AbstractIn recent years, the power conversion efficiencies of halide perovskite solar cells (PSCs) have reached 25.7%. Further commercialization puts forward higher requirements for the stability of PSCs under different stresses. Current research on the stability of PSCs predominantly focuses on investigating the effects of temperature, humidity, oxygen, ultraviolet light, and electrical bias stress, while stability under reverse bias has been poorly studied among the many factors. When large‐area application of PSCs panels occurs, the shading effect and local hot spots of PSCs modules in real scenarios all indicate that the research on reverse bias stability of PSCs is urgently needed. Within this review, a bird's‐eye view of the recent advances on the reverse bias stability issue and reverse bias behavior of PSCs is obtained, and the related mechanisms behind that have been proposed so far are reviewed and discussed. Furthermore, future directions are provided for further improving the reverse bias stability of PSCs via increasing the reverse breakdown voltage (VRB). This review aims to promote the establishment of well‐established reverse bias degradation and reverse breakdown mechanisms of PSCs as well as to establish standardized test procedures for reverse bias stability issues on the road to commercialization of PSCs.

Combined effect of elevated temperature and drought stress on carbohydrate metabolism of cotton (Gossypium hirsutum L.) subtending leaves.

High temperatures and drought are expected to become more frequent in the future and last longer than ever before. To investigate their combined effect on cotton subtending leaves (LSCB), an experiment was conducted from 2016 to 2018 using a non-heat-tolerant cotton cultivar and a heat-tolerant cultivar. Two temperature regimes with ambient temperature (AT, 31.0/26.4 °C) and elevated temperature (ET, 33.4/28.9 °C, 2.5 °C higher than AT) and three drought treatments with a soil relative water content (SRWC) of 75 ± 5%, 60 ± 5%, and 45 ± 5% were established repeatedly. ET decreased Pn, initial rubisco activity (4.1.1.39, RuBP) and cy-FBPase (3.1.3.11) activity, upregulated GhSuSyA, and GhSuSyD expressions, and increased SuSy (2.4.1.13) activity, which led to the decline of the final starch and sucrose contents. Moreover, RuBP, Pn, and starch content all decreased with drop in SRWC levels, but the cy-FBPase and SPS (2.4.1.14) activity increased, which in turn increased sucrose content. Under combined stresses, when the changing trends of ET and drought effects were the same, the decrease of Pn, RuBP, and starch content was greater than under single stress exposure. However, when the changing trends of ET and drought effects were adverse, the combined effects on indicators such as cy-FBPase, SuSy, sucrose content were mostly similar to drought stress. These results indicate that the effect of drought on carbohydrate metabolism in LSCB is more prominent than ET. Thus, the drought effect for carbohydrate metabolism in LSCB may need more attention than ET under combined heat and drought stress. This article is protected by copyright. All rights reserved.

Kaolin particle film mitigates supra-optimal temperature stress effects at leaf scale and increases bean size and productivity of Coffea canephora

Summary In young plants of Coffea canephora, fine particle film based on calcined kaolin (KF) causes a decrease in leaf temperature (Tleaf), minimizing the damages to the photochemical apparatus, especially in summer season, but no report about the ecophysiological responses to KF over phenology is available on this species. We hypothesized that greater ecophysiological effects of KF would occur during the summer phenophase of leaf area and berry expansion (BE) compared with autumn berry maturation phase (BR), and that those benefits will have impact on bean productivity and physical quality. In this sense, the present study aimed to analyze the effects of KF on some ecophysiological parameters in the last phenophases of C. canephora biennial cycle, bean productivity, and bean size classification. During the complete phenological cycle, eight applications of KF were performed, totaling 80 kg of KF ha−1 in two years. KF applications and ecophysiological measurements occurred during the BE and BR phenophases. Firstly, we documented temporal dynamics in responses of field-grown C. canephora adult plants to KF application. KF reduced Tleaf and crop water stress index and increased the thermal index of relative stomatal conductance and relative chlorophyll content (SPAD index) observed in the autumn BR (opposite to young plants). The positive impact of KF on chlorophyll a fluorescence was proportionally similar among the observed phenophases. Secondly, KF increased bean size 16 by 50% and increased total productivity. The plants treated with KF increased productivity by 1.7 t ha− commercially useful bean mass compared to the control. The kaolin dose of 40 kg ha−1 distributed four times per year was highly effective as a protection strategy against high-light and elevated Tair.

The effect of temperature and relative humidity on milk yield of holstein dairy cattle raised in agricultural enterprises under different climatic conditions

This study was conducted to investigate the effect of air temperature and relative humidity on milk yield of the Holstein dairy cattle raised in Agricultural Enterprises under different climatic conditions in Turkey (Polatlı, Türkgeldi, and Çukurova) and to examine the differences between the enterprises. Records of milk yield on the test day for the years 2014-2020 obtained from the General Directorate of Agricultural Enterprises (TİGEM) were utilised in the study. The data set related to milk yields included the number of Holstein cows, data on different lactation orders, control records of milk yield and information of the animals for some environmental factors. In the study, values of four temperature-humidity indices (THI) consisting of different combinations of daily maximum and minimum temperature and humidity values were examined in order to assess the effect of temperature stress on milk yield. Consequently, the difference between the enterprises in terms of the combinations of the temperature-humidity index was found to be statistically significant (P<0.05). The THI value calculated for the agricultural enterprises varied between 10 and 102. It was determined that dairy cattle were exposed to heat stress between May and November in Türkgeldi and Polatlı Agricultural Enterprises in the cold climate zone and between April and July in Çukurova Agricultural Enterprises in the temperate climate zone. While the THI value with low humidity weight was the optimal indicator in a humid climate, the THI value with high-temperature weight was the best indicator of heat stress in a semi-arid climate.

Response of a temperate coral to temperature stress: A comparison of populations across sites

The negative effects of warming temperatures on coral physiology are well-documented. However, research increasingly suggests that these effects are variable and that the degree to which corals are impacted by higher temperatures are dependent on a range of environmental and physiological variables. In tropical corals, which live near their upper thermal limits, these disparities have led to significant differences in bleaching and other negative health effects even over relatively small spatial scales. However, the response of temperate corals across small spatial scales is less well understood despite their occurrence in areas with larger temperature ranges than their tropical counterpart. To determine whether responses to thermal stress (27.4 versus 29 °C) differed in a common temperate coral species across a small geographic area, as has been documented in tropical corals, we evaluated coral growth and photosynthetic efficiency (Fv/Fm) of the coral Oculina arbuscula over the course of eight weeks when grown at differing temperatures. When measured as buoyant mass (calcification), growth of O. arbuscula did not differ as a function of temperature or site of collection. In contrast, when measured as change in tissue mass or total wet mass, elevated temperature suppressed growth. Change in total wet mass also varied significantly by collection site, corals from some sites experiencing little if any growth and those from other sites experiencing negative growth. Photosynthetic efficiency (Fv/Fm) was significantly lower at 29 °C than at 27.4 °C. Analyses of symbionts showed that sequence variants related to the genus Breviolum made up ∼98% of all Symbiondiniaceae across all sites and temperature treatments with one variant (100% sequence identity to Breviolum psygmophilum) being 91% of the total community. Only one Symbiodiniaceae, with a 99.28% sequence identity to Breviolum psygmophilum, differed significantly as a function of temperature. It also comprised only 1–3% of the community. Bacterial microbiome variance increased during our experiment, but there were no significant effects of temperature or collection site. For O. arbuscula from these collection sites, location did not impact the coral's ability to withstand the effects of temperature stress.

The effects of temperature stress and population origin on the thermal sensitivity of Lymantria dispar L. (Lepidoptera: Erebidae) larvae

Increased environmental temperature is one of the most frequent stresses effecting metabolic rate in herbivorous insect species. Our goal was to compare the influence of increased environmental temperature and induced thermotolerance on the activity of midgut phosphatases and brain tissue hsp70 concentration in 5th instar Lymantria dispar larvae originating from an unpolluted and polluted forest. Induced thermotolerance (larval pre-treatment at high, sub-lethal temperature) increases the species ability to overcome the negative effects of thermal stress, therefore we monitored the effect of this regime in larvae originating from both forests. Thermal regimes in this experiment predominantly influenced the alkaline phosphatases activity and it was affected by temperature, population origin, and their combined effect. Total acid phosphatases activity was changed only by the joint effect of temperature and population origin. Brain hsp70 concentration was under a significant individual and joint effect of temperature and population. In both populations, brain tissue hsp70 concentration and alkaline phosphatases activity should be taken under consideration as a battery with biomarker potential for thermal stress in L. dispar larvae as a bioindicator species.

Starch parameters and short-term temperature fluctuations – Important but not yet in focus?

Plants are regularly challenged by unfavorable environmental conditions. As climate change continues, adverse situations such as drought, heat, and cold are expected to increase and become more severe. Most starchy crops are affected by such stresses. In recent years, researchers have made many new discoveries about starch metabolism in general and also on granule structure, including effects on starch following longer-term temperature stresses. However, in this study, we focus on short-term temperature stress on storage starch granule properties. Here our knowledge is less and it is likely that also short-term temperature stresses can affect various starch parameters. Therefore, we see a need for this type of analysis and discuss the matter in more detail and we conclude that a deeper knowledge particularly of starch granule parameters could allow targeted breeding of cultivars that exhibit different starch characteristics as a result of short-term stress. For these reasons, we are convinced that more comprehensive research on the effects of short-term temperature stress on starch granule characteristics is important, necessary, and timely.

Application of transcriptome analysis to investigate the effects of long-term low temperature stress on liver function in the tiger puffer (Takifugu rubripes)

The tiger puffer (Takifugu rubripes) is an important economic fish species in northern China. However, it is a warm-temperature species, and low winter temperatures can result in high mortality in aquaculture. Understanding the mechanisms of cold resistance in tiger puffers will thus provide critical information to help cope with winter cold. In this study, we performed transcriptome analysis of livers from puffer fish kept at different temperatures (18°C, 13°C, and 8°C) to identify the key pathways and genes involved in the response to low-temperature stress. We also detected serum levels of proteases, arginine, and proline to obtain further information on the response to cold adaption. Totals of 51, 942, and 195 differentially expressed genes were identified in the 18°C vs 13°C, 18°C vs 8°C, and 13°C vs 8°C groups, respectively. Pathway analysis showed that significantly enriched pathways were mainly related to digestion, metabolism, and environmental adaptation. Most genes in the pathways related to digestion and metabolism were down-regulated, while most genes in the pathways related to environmental adaptation were up-regulated. Serum levels of proteases were significantly lower in the low-temperature groups (13°C and 8°C) compared with the control group (18°C), while arginine and proline levels were significantly higher in the 8°C group compared with the other two groups. These results suggest that low temperature caused digestive and metabolic disorders, as well as adaptive changes to low temperature in tiger puffers. On this premise, we found that some up-regulated genes in the pancreatic secretion pathway, arginine and proline metabolism pathway, and circadian rhythm pathway played important roles in the survival, growth, and development of tiger puffers under low-temperature stress. The accumulation of arginine and proline can maintain metabolism and circulation and resist cold stress. The circadian rhythm is closely related to digestion and metabolism, which is an adaptive change and plays a positive role in the resistance to low temperature. The results of this study provide new insights and a theoretical basis for the study of cold tolerance in tiger puffers.

The effects of different thermal and chemical stresses on release of outer membrane vesicles (OMVs) by ClearColi™.

The highly immunogenic properties of outer membrane vesicles (OMVs), small spherical nanoparticles commonly released by Gram-negative bacteria, led to their application as vaccine candidate. ClearColi™ is an engineered Escherichia coli strain, which does not produce endotoxic response in humans and is useful for production of OMV-based vaccines. Therefore, producing ClearColi™ OMVs with high yield attracts particular interest. As stresses can be removed by OMVs, they may affect OMVs release. We aimed to investigate the effects of culture temperature, chemical (NaCl, ethanol, EDTA, D-cycloserine, polymyxin B, 1-octanol, and H2O2) and thermal stresses on release of ClearColi™ OMVs. Herein, the growth rate of ClearColi™ was decreased in the presence of all chemical stresses with the exception of H2O2. The optimum temperature for OMVs production was 37℃ and their release was not increased under thermal shock. The highest and lowest OMVs release was obtained in the presence of NaCl and H2O2, respectively. Electron microscopy images confirmed that the bilayer spherical-shaped OMVs were isolated under different stresses. Furthermore, SEM and DLS analysis demonstrated that OMVs released under EDTA stress are smaller than those released from untreated cultures. It can be concluded that chemical stresses have influence on the level of ClearColi™ OMVs production. However, changes in their content should be further investigated.