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Hydrophobicity and toxicity of several classes of solvents LD5o Class of compound Specific compound log pa (mmoll_l)
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Many processes in modern biotechnology, particularly biotransformations and environmental bioremediation, are hindered by the toxic effects of organic solvents on whole cells. These compounds dissolve in the cell membrane, disturbing its integrity and effecting specific permeabilization. The hydrophobicity of a compound, expressed as its log P valu...
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Citations
... Phenolic compounds including acids (ferulic acid, vanillic acids, 4-hydroxybenzoic acid, and syringic acid), alcohols (guaiacol, catechol, and vanillyl alcohol) and aldehydes (vanillin, syringaldehyde, and PHB) is another class of inhibitors generated during hydrolysis of lignocellulose [21]. These compounds are known to alter the permeability and the lipid/protein ratio in the membranes, which in turn increases cell uidity, leading to cell membrane disruption, dissipation of proton/ion gradients, and compromising the ability of cellular membranes to act as selective barriers [22]. ...
... This directly affects the cell replication rate [2]. Furthermore, the phenolic compounds (vanillin, syringaldehyde, and PHB) are known to alter the permeability of the cell membrane, in addition to changing the lipid/protein ratio, causing disruption and leakage of cytoplasmic constituents [2,22]. Their breakdown also leads to the production of reactive oxygen species such as hydroxyl, superoxide and peroxide that can denature proteins and damage DNA, leading to an onset of programmed cell death [2,40]. ...
... The inhibitors taken up by the cells and accumulated inside in such high concentrations might have overwhelmed the enzymatic machinery involved in their degradation. When the co-culture reached the stationary phase the inhibitors would further alter the permeability of cellar membranes causing their disruption and leakage of cytoplasmic constituents [22]. Alternatively, as Stubbendieck and Straight [44] have reported, some bacteria can form extracellular vesicles, that are capable of segregating substances, especially in the case of gram-negative bacteria. ...
The growth of Acinetobacter baylyi and Lipomyces starkeyi was investigated individually and in a co-culture in a minimal medium (MM) in the presence of vanillin, syringaldehyde, para-hydroxybenzaldehyde (PHB), furfural and hydroxymethylfurfural (HMF), to understand the growth and lipid accumulation capability. The MM, which was developed in our laboratory, significantly reduced the medium cost for lipid production by L. starkeyi from $12.68 per gallon lipids to $3.11 per gallon lipids with the carbon source representing the remaining major cost factor. A. baylyi failed to grow in the MM but grew in the modified Suutari medium (MSM). L. starkeyi showed a decreased growth in the presence of a mix of 0.1 g/L and 0.25g/L of furfural, HMF, PHB, vanillin, and syringaldehyde in comparison to the growth in the MM without these inhibitors and completely failed to grow when they were present at the 0.5 g/L concentrations. The co-culture of L. starkeyi and A. baylyi in the MM resulted in the maximum cell concentration and lipid production of 9.72 g/L and 5.04 g/L; 9.72 g/L and 4.90 g/L; and 9.24 g/L and 4.65 g/L for the initial inhibitor concentrations of 0.1 g/L; 0.25 g/L and 0.5 g/L, respectively. Almost complete consumption of the inhibitors was observed when they were added at 0.1 g/L and 0.25 g/L concentrations. However, at initial inhibitor concentrations of 0.5 g/L, the inhibitors were first taken up but then released back into the media when the co-culture reached the stationary phase.
... Strain Q4 was checked for its methanol sensitivity as methanol was used for biodiesel production and it is toxic to bacteria. In autoclaved nutrient broth methanol was added in 5%, 10%, and 15% concentrations which were equivalent to the concentrations of methanol used for the trans-esterification reaction (Heipieper et al. 1994). ...
Generally wastewater such agricultural runoff is considered a nuisance; however, it could be harnessed as a potential source of nutrients like nitrates and phosphates in integrated biorefinery context. In the current study, microalgae Chlorella sp. S5 was used for bioremediation of agricultural runoff and the leftover algal biomass was used as a potential source for production of biofuels in an integrated biorefinery context. The microalgae Chlorella sp. S5 was cultivated on Blue Green (BG 11) medium and a comprehensive optimization of different parameters including phosphates , nitrates, and pH was carried out to acquire maximum algal biomass enriched with high lipids content. Dry biomass was quantified using the solvent extraction technique, while the identification of nitrates and phosphates in agricultural runoff was carried out using commercial kits. The algal extracted lipids (oils) were employed in enzy-matic trans-esterification for biodiesel production using whole-cell biomass of Bacillus subtilis Q4 MZ841642. The resultant fatty acid methyl esters (FAMEs) were analyzed using Fourier transform infrared (FTIR) spectroscopy and gas chromatography coupled with mass spectrometry (GC-MS). Subsequently, both the intact algal biomass and its lipid-depleted algal biomass were used for biogas production within a batch anaerobic digestion setup. Interestingly, Chlorella sp. S5 demonstrated a substantial reduction of 95% in nitrate and 91% in phosphate from agricultural runoff. The biodiesel derived from algal biomass exhibited a noteworthy total FAME content of 98.2%, meeting the quality standards set by American Society for Testing and Materials (ASTM) and European union (EU) standards. Furthermore , the biomethane yields obtained from whole biomass and lipid-depleted biomass were 330.34 NmL/g VS added and 364.34 NmL/g VS added , respectively. In conclusion, the findings underscore the potent utility of Chlorella sp. S5 as a multi-faceted resource, proficiently employed in a sequential cascade for treating agricultural runoff, producing biodiesel, and generating biogas within the integrated biorefinery concept.
... These marine organisms, from sponges to viruses, developed adaptation strategies allowing them to survive and thrive in a myriad of hostile and extreme conditions, such as high and low temperatures (2-100 • C), high salinity (up to nearly saturation), and high pressure (>100 atm), and to survive attacks by predators and pathogens [7,8]. The ability of microorganisms to maintain biological functions under stress results from, e.g., changes in protein, sterol, hopanoid, carotenoid, and membrane lipid composition [9,10] and from the synthesis of primary and secondary metabolites [7]. ...
Microbial life present in the marine environment has to be able to adapt to rapidly changing and often extreme conditions. This makes these organisms a putative source of commercially interesting compounds since adaptation provides different biochemical routes from those found in their terrestrial counterparts. In this work, the goal was the identification of a marine bacterium isolated from a sample taken at a shallow water hydrothermal vent and of its red product. Genomic, lipidomic, and biochemical approaches were used simultaneously, and the bacterium was identified as Serratia rubidaea. A high-throughput screening strategy was used to assess the best physico-chemical conditions permitting both cell growth and production of the red product. The fatty acid composition of the microbial cells was studied to assess adaptation at the lipid level under stressful conditions, whilst several state-of-the-art techniques, such as DSC, FTIR, NMR, and Ultra-High Resolution Qq-Time-of-Flight mass spectrometry, were used to characterize the structure of the pigment. We hypothesize that the pigment, which could be produced by the cells up to 62 °C, is prodigiosin linked to an aliphatic compound that acts as an anchor to keep it close to the cells in the marine environment.
... The FA composition of R. erythropolis is heavily influenced by the cultivation conditions, including the carbon and nitrogen source, as well as the pH-value, temperature, and aeration [42]. FA represent an essential part of the phospholipid bilayer of the cellular membrane [57], which allows bacteria to adapt their lipid composition to maintain membrane fluidity and permeability in response to various stress conditions [58,59]. Bacteria of the actinomycetes group store large amounts of TAGs in lipid bodies. ...
The oleaginous bacterium Rhodococcus erythropolis JCM3201T offers various unique enzyme capabilities, and it is a potential producer of industrially relevant compounds, such as triacylglycerol and carotenoids. To develop this strain into an efficient production platform, the characterization of the strain’s nutritional requirement is necessary. In this work, we investigate its substrate adaptability. Therefore, the strain was cultivated using nine nitrogen and eight carbon sources at a carbon (16 g L−1) and nitrogen (0.16 g L−1) weight ratio of 100:1. The highest biomass accumulation (3.1 ± 0.14 g L−1) was achieved using glucose and ammonium acetate. The highest lipid yield (156.7 ± 23.0 mg g−1DCW) was achieved using glucose and yeast extract after 192 h. In order to enhance the dependent variables: biomass, lipid and carotenoid accumulation after 192 h, for the first time, a central composite design was employed to determine optimal nitrogen and carbon concentrations. Nine different concentrations were tested. The center point was tested in five biological replicates, while all other concentrations were tested in duplicates. While the highest biomass (8.00 ± 0.27 g L−1) was reached at C:N of 18.87 (11 g L−1 carbon, 0.583 g L−1 nitrogen), the highest lipid yield (100.5 ± 4.3 mg g−1DCW) was determined using a medium with 11 g L−1 of carbon and only 0.017 g L−1 of nitrogen. The highest carotenoid yield (0.021 ± 0.001 Abs454nm mg−1DCW) was achieved at a C:N of 12 (6 g L−1 carbon, 0.5 g L−1 nitrogen). The presented results provide new insights into the physiology of R. erythropolis under variable nutritional states, enabling the selection of an optimized media composition for the production of valuable oleochemicals or pigments, such as rare odd-chain fatty acids and monocyclic carotenoids.
... Toxicity of 2,4-D towards yeast cells is mainly due to the activity of the non-dissociated form (Cabral et al., 2003). It suggests that the lipid bilayer in plasma membranes is one of the biological targets of the herbicide; it may be either due to direct interaction between this highly lipophilic form and membrane lipids, thus affecting spatial organization of membranes (Heipieper et al., 1994), or due to lipid peroxidation as the consequence of its activity as a pro-oxidant agent (Teixeira et al., 2004). On the other hand, fungicides aim at disruption of integrity of cell membranes and cell walls of fungi. ...
In this study, alcoholic fermentation was explored to reduce the pesticides—2,4-dichlorophenoxyacetic acid (2,4-D) and procymidone—and the mycotoxin ochratoxin A (OTA), besides evaluating their effects on quality parameters of the process. Fermentation (at 20 °C for 168 h) was conducted in synthetic must (YPD and 10 g hL⁻¹ of yeast Saccharomyces cerevisiae) to which the following were added: 2,4-D (6.73 mg L⁻¹) and procymidone (2.24 mg L⁻¹), simultaneously (treatment 1); and OTA (0.83 and 2.66 µg L⁻¹) (treatments 2 and 3). The control treatment had no contaminants. All contaminated treatments showed lower ethanol production and cell viability. The highest decrease in contaminants was found after 168 h of fermentation: 22 and 65% in the cases of both pesticides while OTA decreased 52 and 58% (treatments 2—0.83 µg L⁻¹ and 3—2.66 µg L⁻¹). Decrease in procymidone and OTA due to metabolic processes in yeast cells is mainly related to peroxidase activity and glutathione production.
... Blood concentration at the mg/L range may initiate hematological responses. Organic solvents are reported to have nonspecific physicochemical effects and can modulate cell membrane fluidity and influence the hydrophobic force regulating macromolecular interactions (Heipieper et al., 1994;Quinn, 1981). These properties explain the use of organic solvent to dissolve membrane lipids and release the integral proteins and subcellular components. ...
Glycol ethers are solvents used in a plethora of occupational and household products exposing the users to potential toxic effects. Several glycol ethers derived from ethylene glycol induce hematological toxicity, such as anemia in workers. The exposure effects on blood cells of glycol ethers derived from propylene glycol are unknown in humans. The aim of our study was to evaluate blood parameters indicative of red blood cell (RBC) hemolysis and oxidative stress in participants exposed to propylene glycol (propylene glycol monobutyl ether (PGBE) and propylene glycol monomethyl ether (PGME), two extensively used propylene glycol derivatives worldwide). Seventeen participants were exposed 2 h in a control inhalation exposure chamber to low PGME (35 ppm) and PGBE (15 ppm) air concentrations. Blood was regularly collected before, during (15, 30, 60, and 120 min), and 60 min after exposure for RBC and oxidative stress analyses. Urine was also collected for clinical effects related to hemolysis. Under the study conditions, our results showed that the blood parameters such as RBCs, hemoglobin concentration, and white blood cells tended to increase in response to PGME and PGBE exposures. These results raise questions about the possible effects in people regularly exposed to higher concentrations, such as workers.
... However, the largest concentration of OEO used (20 mg/mL) resulted in a bacteriostatic effect as the population was controlled at 5.56 ± 0.07 Log CFU/mL, but this effect was lost after 18 h when the population increased 2 Log cycles ( Figure 2a). The sublethal effect of OEO has been attributed to an increased concentration of saturated fatty acids of the bacterial membrane, causing a non-specific decrease in cell permeability [23,24]. On the other hand, after 6 h of incubation, the microbial population decreased in the presence of 0.25 and 0.5 mg/mL CH, but this effect only lasted for 18 h (Figure 2b). ...
... In addition, the composition of essential oils can be affected by a variety of factors, such as the part of the plant used for extraction, the type of drying, the maturation stage of the plant during harvest, and growing conditions such as soil type, temperature and fertilizers used [25]. effect of OEO has been attributed to an increased concentration of saturated fatty acids of the bacterial membrane, causing a non-specific decrease in cell permeability [23,24]. On the other hand, after 6 h of incubation, the microbial population decreased in the presence of 0.25 and 0.5 mg/mL CH, but this effect only lasted for 18 h (Figure 2b). ...
... The tensile strength of the 9:1 weight ratio treatments did not show significant differences, presenting values similar to low density polyethylene (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25). In the case of the 4:1 treatments added with A-MSN and OEO, the tensile strength was lower than the control, or the MSNO films, whose values are similar to high density polyethylene (19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31) or polystyrene (31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45)(46)(47)(48)(49). ...
Beef is a fundamental part of the human diet, but it is highly susceptible to microbiological and physicochemical deterioration which decrease its shelf life. This work aimed to formulate an active edible film (AEF) incorporated with amino-functionalized mesoporous silica nanoparticles (A-MSN) loaded with Mexican oregano (Lippia graveolens Kunth) essential oil (OEO) and to evaluate its effect as a coating on fresh beef quality during refrigerated storage. The AEF was based on amaranth protein isolate (API) and chitosan (CH) (4:1, w/w), to which OEO emulsified or encapsulated in A-MSN was added. The tensile strength (36.91 ± 1.37 MPa), Young’s modulus (1354.80 ± 64.6 MPa), and elongation (4.71%) parameters of AEF made it comparable with synthetic films. The antimicrobial activity of AEF against E. coli O157:H7 was improved by adding 9% (w/w) encapsulated OEO, and interactions of glycerol and A-MSN with the polymeric matrix were observed by FT-IR spectroscopy. In fresh beef, after 42 days, AEF reduced the population growth (Log CFU/cm2, relative to uncoated fresh beef) of Brochothrix thermosphacta (5.5), Escherichia coli (3.5), Pseudomonas spp. (2.8), and aerobic mesophilic bacteria (6.8). After 21 days, odor acceptability of coated fresh beef was improved, thus, enlarging the shelf life of the beef and demonstrating the preservation capacity of this film.
... Firstly, the microbes secreted more PS and PN in response to the high concentration of Nap. Secondly, the high enrichment of lipophilic Nap led to swelling and cleavage of the cell membrane, disrupting the ion gradient concentration, and eventually led to cell lysis and the release of organic matter, which increased the PN and PS of EPS [30,31]. Li et al. [32] stated that PS would form complex networks, which might inhibit the efficiency of the mass transfer. ...
Polycyclic aromatic hydrocarbons (PAHs) are widely distributed in the sludge environment due to activities such as oil extraction and pose a serious threat to deep-seated anaerobic microorganisms. Thus, in this study, we discussed the dose–response efficiency of naphthalene (Nap, a typical PAH) on anaerobic digestion (AD) through co-metabolic degradation via batch experiments. The batch results showed that 30 mg/L Nap promoted the AD with the accumulation of CH4 18.54% higher than the control (without Nap) by increasing the efficiency of hydrolysis and acetogenesis 99.49% and 61.95%, respectively. However, adverse effects were observed with an excessive dosage of Nap (higher than 100 mg/L) with a decrease of methane production (37.16) with 2000 mg/L Nap. Interestingly, the concentrations of the polysaccharide and protein reached the highest at 138.76 mg/L and 400.41 mg/L, respectively, in 1000 mg/L Nap. Furthermore, the high activities of hydrolase and transmembrane ATPase were acquired in 30 mg/L Nap. In addition, Nap significantly affected the methanogenic microbial abundance and diversity, especially diminishing Methanolinea and Syntrophobacter. Furthermore, the enrichment of Bacteroides in 30 mg/L Nap showed moderate Nap could facilitate hydrolysis. The genes relevant to cellular processes were activated by Nap. This research provided a reliable basis for the anaerobic microbial response under Nap stress.
... Due to these abilities, bacteria can easily adapt to changing environmental conditions [66]. Therefore, some of them are proposed as biomarkers of either toxicity or resistance to the substances such as monochlorophenols [67], polycyclic aromatic hydrocarbons [68], organic solvents [69], and even antibiotics [61]. In the paper by Hussein et al. [62], significant modifications of FA composition in the P. aeruginosa FADDI-PA111 strain treated with amikacin were indicated. ...
Proteus mirabilis is a common cause of catheter-associated urinary tract infections (CAUTIs). In this study, we verified the effectiveness of amikacin or gentamicin and ascorbic acid (AA) co-therapy in eliminating uropathogenic cells, as well as searched for the molecular basis of AA activity by applying chromatographic and fluorescent techniques. Under simulated physiological conditions, a combined activity of the antibiotic and AA supported the growth (threefold) of the P. mirabilis C12 strain, but reduced catheter colonization (≤30%) in comparison to the drug monotherapy. Slight modifications in the phospholipid and fatty acid profiles, as well as limited (≤62%) 2’,7’-dichlorofluorescein fluorescence, corresponding to the hydroxyl radical level, allowed for the exclusion of the hypothesis that the anti-biofilm effect of AA was related to membrane perturbations of the C12 strain. However, the reduced (≤20%) fluorescence intensity of propidium iodide, as a result of a decrease in membrane permeability, may be evidence of P. mirabilis cell defense against AA activity. Quantitative analyses of ascorbic acid over time with a simultaneous measurement of the pH values proved that AA can be an effective urine acidifier, provided that it is devoid of the presence of urease-positive cells. Therefore, it could be useful in a prevention of recurrent CAUTIs, rather than in their treatment.
... These compounds rarely occur in high concentrations under natural conditions. This is probably the reason why even small amounts of these substances are harmful to cells [19,20]. ...
During pulping large quantities of spent liquor are generated, which contain high amounts of degraded poly- saccharides. These saccharides represent a good substrate for various biotechnological processes.
In addition to the mono- and oligomeric sugars, the waste liquors contain other substances that may have inhib- itory effects on the microorganisms used in the fermentation processes. This work was designed to understand the interaction of potential inhibitors with living cells by employing NMR spectroscopy.
The investigation of the interaction of the anaerobic ethanol producer Thermoanaerobacter mathranii and the aerobic polyhydroxyalkanoate (PHA) producer Halomonas halophila with potential inhibitors shows that all substances with aldehyde moieties change their structure during the fermentation, while all other inhibitors remain unchanged. Furthermore, the reduction of the aldehyde group to the hydroxyl group takes place throughout the interaction with anaerobic microorganisms and the oxidation to the carboxylic acid throughout the interaction with aerobic microorganisms.
Finally, the effect of the corresponding alcohols and carboxylic acids formed during the fermentation on the growth of bacteria was investigated. The experiments proved that the newly formed substances have a less inhibitory effect on the cells than their parent components with aldehyde groups.
