ACTA BIOCHIMICA POLONICA

Effects of postpartum hormonal changes on the immune system and their role in recovery
Wu X and Jin R
The postpartum period involves complex physiological changes, notably in hormone levels, that significantly influence immune system function. Hormonal regulation during pregnancy prevents maternal immune rejection of the fetus, but following childbirth, these hormone levels drop rapidly, leading to immune reconstitution.
PKC in the perspective of dopamine receptor signaling
Ma H
Protein kinase C (PKC) is widely distributed in various tissues, organs, and cells. By catalyzing the phosphorylation of Ser/Thr residues on various proteins, PKC regulates the metabolism, growth, proliferation, and differentiation of multiple cells and plays a crucial role in transmembrane signal transmission. In dopamine receptor signal transduction, PKC regulates numerous physiological functions, such as dopamine release, internalization of the dopamine transporter, downregulation of dopamine receptors, etc. In disease conditions, hyperactivation of PKC can lead to disorders such as schizophrenia and Parkinson's disease, while reduced PKC signaling may be associated with Alzheimer's disease. In the past few decades, researchers have paid increasing attention to the transduction role of PKC in dopamine receptor signaling, aiming to identify and discover potential targets for dopaminergic diseases. This review, from the perspective of signal transduction between dopamine receptors and PKC, reveals the pivotal hub position of PKC in the intracellular signal transduction network and its regulation of various physiological functions, providing ideas for future research on PKC and therapeutic interventions for dopaminergic diseases.
Resistance of HEK-293 and COS-7 cell lines to oxidative stress as a model of metabolic response
Sapeta-Nowińska M, Sołtys K, Gębczak K, Barg E and Młynarz P
Oxidative stress (OS), arising from an imbalance between reactive oxygen species (ROS) production and antioxidant defenses, plays a pivotal role in cellular dysfunction and the pathogenesis of numerous diseases. This study evaluates the impact of oxidative stress induced by hydrogen peroxide on the metabolomic profiles of the human embryonic kidney (HEK-293) and African green monkey kidney (COS-7) cell lines. Viability (MTT) and free radical accumulation (DCF-DA) assays confirmed a dose-dependent cytotoxic effect of hydrogen peroxide, with COS-7 cells exhibiting greater resistance and producing lower levels of intracellular ROS compared to HEK-293. Metabolomic profiling was conducted using nuclear magnetic resonance spectroscopy (H NMR) to identify and quantify metabolic changes. Exposure to a free radical inducer significantly altered both intracellular and extracellular metabolites compared to control HO-free samples. The analysis revealed common changes in intracellular metabolites between the two lines, including glutamate, NAD, glutathione, ATP/ADP, AMP, and pyruvate - key molecule for mitochondrial function, as well as extracellular metabolites such as glutamate, glutamine, acetate, lactate, and pyruvate. Metabolomic differences observed in COS-7 cells suggest a potentially greater capacity for metabolic adaptation to oxidative stress. These included elevated levels of branched-chain amino acids (BCAA), supporting energy production, and increased formate production, which may aid purine synthesis and cellular resilience. These findings highlight the distinct metabolic adaptations of COS-7 cells to oxidative stress in comparison to the HEK-293 cell line. They also provide insights into the direct cellular responses to altered redox potential, offering possible therapeutic strategies aimed at targeting metabolic pathways to mitigate oxidative stress.
Monitoring and optimization of POCT devices in a multi-specialty hospital in Poland: usage trends, quality assurance, and clinical impact (2017-2024)
Woźniak-Kosek A and Drążek L
Rapid access to blood laboratory test results is crucial for diagnosing and treating patients in life-threatening conditions. Oxygenation status and acid-base balance are determined on arterial blood gasometry and are vital components of modern treatment algorithms for critically ill patients, similar to capillary blood glucose level measurement. The aim of this study is to present a modern method of reporting the work of critical parameter analyzers and glucometers in a multi-speciality hospital. The material for the analysis consisted of data obtained during the supervision of POCT devices in the clinics/departments/institutes of MIM-NRI from 2017 to 2024. Analyzing the use of glucometers in MIM-NRI from 2017 to 2024, it was noted that their usage significantly increased during the COVID-19 pandemic compared to the previous period. Currently, 112 devices are continuously used in both locations. All of them are subject to international and national quality testing, as well as daily internal calibration checking at their workplaces. There are currently 13 analyzers of critical parameter in the clinics and departments of MIM-NRI. All operate within the AQURE system, which allows for monitoring the correct operation of these devices and helps in quickly identifying analytical problems and reporting in real-time about the device's operational status. In the first half of 2024, 40,082 blood sample tests were performed on patients. Analysis of correctly performed gasometric tests conducted in clinics and laboratories shows similar values, ranging from 84.17% to 86.38%. In addition to external control, critical parameter devices must necessarily undergo daily internal laboratory control and calibration. The highest number of correctly performed calibrations, 9,239, was recorded in the Cardiac Surgery Clinic's Intensive Therapy Unit, accounting for 29% of all correctly performed calibrations for these devices. In the analyzed period of 2024, the rate of correctly performed quality checking's was 82.26%. The highest number of correct analyses, 636, was conducted in the Intensive Therapy Unit of the hospital in Legionowo, accounting for 10.32% of all controls performed. The demand for POCT tests in Polish hospitals is steadily growing due to their enormous potential and the time savings associated with performing tests directly at the patient's bedside. The greatest advantage of POCT is that by providing quick access to test results, diagnosis can be accelerated, and treatment initiated more rapidly. Additionally, POCT tests conducted in emergency rooms or hospital emergency departments can help to reduce the number of unnecessary hospitalizations or costly imaging tests. Having an appropriate POCT data management system in a multi-specialty hospital and ensuring IT communication is currently indispensable for proper patient care.
Advancements in single-cell RNA sequencing and spatial transcriptomics: transforming biomedical research
Molla Desta G and Birhanu AG
In recent years, significant advancements in biochemistry, materials science, engineering, and computer-aided testing have driven the development of high-throughput tools for profiling genetic information. Single-cell RNA sequencing (scRNA-seq) technologies have established themselves as key tools for dissecting genetic sequences at the level of single cells. These technologies reveal cellular diversity and allow for the exploration of cell states and transformations with exceptional resolution. Unlike bulk sequencing, which provides population-averaged data, scRNA-seq can detect cell subtypes or gene expression variations that would otherwise be overlooked. However, a key limitation of scRNA-seq is its inability to preserve spatial information about the RNA transcriptome, as the process requires tissue dissociation and cell isolation. Spatial transcriptomics is a pivotal advancement in medical biotechnology, facilitating the identification of molecules such as RNA in their original spatial context within tissue sections at the single-cell level. This capability offers a substantial advantage over traditional single-cell sequencing techniques. Spatial transcriptomics offers valuable insights into a wide range of biomedical fields, including neurology, embryology, cancer research, immunology, and histology. This review highlights single-cell sequencing approaches, recent technological developments, associated challenges, various techniques for expression data analysis, and their applications in disciplines such as cancer research, microbiology, neuroscience, reproductive biology, and immunology. It highlights the critical role of single-cell sequencing tools in characterizing the dynamic nature of individual cells.
New analogs of 5-substituted-2(1)-pyridone containing of natural amino acids as potential drugs in idiopathic pulmonary fibrosis. Investigation and preliminary
Dzierzbicka K, Skrzypkowska M, Gensicka-Kowalewska M, Daśko M and Słomiński B
The aim of our work was to analyze new functionalized analogues of 5-substituted-2(1)-pyridone containing of natural amino acids derivatives as a potential drugs in idiopathic pulmonary fibrosis (IPF). The creation of connections with natural amino acids was aimed at obtaining anti-fibrotic compounds with better water solubility, increased hydrophilicity, lower toxicity and better pharmacokinetic properties. For the docking studies the corresponding grid box parameters were used: PARPγ, ALK5 andp38. During our initial research we have synthesized and performed biological studies for two analogues selected on the basis of molecular modeling: and . MTT test have been performed to select concentrations of PFD derivatives for subsequent analysis. We have analyzed HLA-DR and CXCR4 expression on fibroblasts and 24 h migration of TGF-β1-stimulated fibroblasts. We have also explored proliferation and production of TGF-β1 as well as IL-17 by CD3/CD28 beads-stimulated PBMCs. Preliminary studies show that the designed compounds exhibit promising potential as anti-fibrotic therapeutics. Therefore, their activity is worth further exploring.
Multi-modal comparison of murine and human incisal dentin-enamel junctions
Truhlar M, Katebifar S, Rosenberg B, Kroger R and Deymier AC
Human and mouse incisors are both primarily composed of dentin and enamel, which meet at an interface called the dentin-enamel junction (DEJ). However, incisors in the two species have very different growth patterns, structures, and loading requirements. Since the DEJ is responsible for minimizing cracking at this at-risk interface between mechanically dissimilar dentin and enamel, its structure is expected to be significantly different between humans and mice. Here, structural and compositional gradients across human and murine incisors DEJs were measured via microcomputed tomography and Raman spectroscopy. Density gradients across the DEJ were significantly larger in humans compared to murine teeth, likely due to the larger size of the mantle dentin. Multiple gradients in mineral content and crystallinity were found at the murine DEJ, while the human DEJ only exhibited gradients in mineral content. Models predicting the modulus across the DEJ according to compositional results show that mineral crystallinity is critical in regulating gradients in tissue stiffness across the murine DEJ. Together, these results show the multiple ways in which the DEJ can adapt to variations in the loading environment.
Drug susceptibility of uropathogens isolated from patients treated at the Mazovian Specialized Hospital in Radom
Trześniewska-Ofiara Z, Mendrycka M and Woźniak-Kosek A
Urinary tract infections (UTI) are a significant problem among populations worldwide. It is mainly associated with the increasing incidence of recurrence, complications and the increasing drug resistance of uropathogens. The aim of this study was to demonstrate the prevalence of resistance among pathogens causing urinary tract infections. The material for the study was data obtained from the Mazovian Specialized Hospital (M.S.H) in Radom over a period of 2 years. Urine was collected from hospitalized patients with UTI. Statistical calculations were performed using statistical software. During the study period, 3,917 patients underwent microbiological examination of urine, and almost 15% of them were found to be infected with UTI. Based on statistical analysis of drug susceptibility of the most common uropathogens, it was shown that urinary tract infections caused by or , among others, often show high resistance to fluoroquinolones and β-lactam antibiotics. strains have been shown to be more resistant to aminoglycosides and fluoroquinolones than to beta-lactams. In the case of aeruginisa, resistance to fluoroquinolones predominates. On the other hand, UTI caused by Acientobacter baumannii should be treated based on the results of drug susceptibility testing due to the increasing prevalence of multidrug-resistant strains.
Molecular targets of cannabinoids and their derivatives in epilepsy - a review with focus on CBD
Marciniak S, Wasyluk W and Wojtak A
In recent years, cannabinoids and their derivatives have been tested for efficacy in epilepsy therapy and related disorders. Many of them may help alleviate ailments associated with seizures. An in-depth study of cannabinoid derivatives and the receptors on which they operate give us a chance for more effective use of these substances in epilepsy therapy. Many studies point to the beneficial synergy of cannabinoids with chemotherapeutics and the increase in effectiveness of the latter. As a result, both alternatives to drug treatment and support for the pharmacotherapy are being developed. In this review, we focused on compounds such as Δ9-THC, CBDV, Δ9-THCA, Δ9-THCV, H2CBD and their receptors as well as on CBD's actions, and the enzymes, ion channels, and transporters engaged in the fundamental causes of epileptic seizures. Treating epilepsy and drug-resistant epilepsy are the two common medical uses of cannabinoids. We looked at approximately 150 current scientific articles from peer-reviewed journals to explore the molecular effects of cannabinoids in these applications. Our goal was to improve physician awareness of factors influencing treatment decisions and potential adverse reactions to minimize medical errors and optimize patient care.
Synergistic combination of cannabidiol and celecoxib or 2,5-dimethylcelecoxib exerts oxidative stress-mediated cytotoxicity and mitigates glioblastoma invasiveness
Rybarczyk A, Majchrzak-Celińska A and Krajka-Kuźniak V
Glioblastoma remains one of the most aggressive and treatment-resistant malignancies. Current treatment options, such as radio- and chemotherapy, induce oxidative stress-mediated DNA damage leading to cancer cell death, but are also neurotoxic and not efficient in long term. Our study investigated the effects of cannabidiol, celecoxib and 2,5-dimethylcelecoxib, individually and in combinations, on U-138 MG glioblastoma cell survival, oxidative stress, canonical and non-canonical Nrf2 pathway activation, cell migration and apoptosis. Using the MTT and flow cytometry assay we found that the analyzed compounds and their combinations induce dose-dependent, synergistic, and oxidative stress-related cytotoxicity, with minimal impact (at the concentrations exhibiting anti-cancer effects) on non-cancerous human astrocyte (HA) cell line. The Nrf2 ELISA assay was used for the analysis of the nuclear binding of the nuclear factor-2 erythroid related factor-2 (Nrf2), which followed by the RT-qPCR and Western blot analysis, confirmed the antioxidant response of cells to the applied treatments. Diminished migratory potential, and increase of the autophagy-related p62, LC3 and apoptosis-related caspase-3 protein levels were also observed in response to the treatment with the analyzed compounds. Overall, our study provides evidence that cannabidiol combined with celecoxib or 2,5-dimethylcelecoxib may represent a promising strategy for glioblastoma treatment.
Modulation of inflammatory and adrenergic pathways in hypertension: effects of β-blockers on cytokine release in Jurkat T cells
Kajaia N, Enukidze M, Machavariani M, Maminaishvili T, Kalmakhelidze S, Ormotsadze G and Sanikidze T
Research aimed to examine the effects of β-blockers on cytokine release in Jurkat cells under basal conditions and during oxidative stress. Oxidative stress was induced in Jurkat cells through the application of hydrogen peroxide (HO). Subsequently, β-blockers were administered to the incubation medium for 24 h, encompassing both intact and oxidatively stressed cell conditions. For β-blocker toxicity screening, the viability of Jurkat cells was determined using the MTT (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide) test. The IL-6, IL-17, and TNF-α content were measured in the supernatant of Jurkat cells incubated under different conditions. The study results show that propranolol, metoprolol, carvedilol, but not nebivolol, revealed toxic effects on the intact Jurkat cells (p = 0.0001; p > 0.0001; p = 0.0003; p = 0.0525). Under oxidative stress conditions, the viability of Jurkat cells decreased significantly (p = 0.0001). Propranolol and metoprolol did not affect ((p = 0.0001; p > 0.0001), while nebivolol and carvedilol improved the viability of Jurkat cells incubated under oxidative stress conditions (p = 0.002; p = 0.0002). Oxidative stress significantly increased the cytokines (IL-6, TNF-α, IL-17) expression levels (p < 0.0001; p < 0.0001; p < 0.0001) in Jurkat cells. Propranolol, carvedilol, nebivolol, and metoprolol did not significantly affect the expression levels of IL-6, TNF-α, and IL-17 in intact Jurkat cells, but decreased IL-6, TNF-α, and did not change IL-17 expression levels in Jurkat cells incubated under oxidative stress conditions. This study demonstrates that β-blockers can influence redox-sensitive cytokine pathways in Jurkat T lymphocytes when they are under oxidative stress. All the agents tested inhibited the production of IL-6 and TNF-α, but nebivolol and carvedilol showed the strongest protective and anti-inflammatory effects. These effects likely result from their combined properties, including antioxidant effects, nitric oxide modulation, and the regulation of NF-κB/MAPK pathways. In contrast, propranolol and metoprolol exhibited more limited activity. These findings suggest that third-generation β-blockers may offer both cardiovascular and immunomodulatory benefits, although further validation in primary immune cells and models is still required.
Salivary biomarkers in cancer detection and management
Munsif A, Nowaczyk A, Fijałkowski Ł, Riaz S and Jamil A
Studies have identified specific salivary biomarkers associated with different types of cancer, including oral, lung, and pancreatic cancers. These biomarkers can be proteins, DNA fragments, or other molecules that indicate the presence or progression of the disease. Saliva-based cancer detection offers the potential for earlier diagnosis, leading to better treatment outcomes. Additionally, salivary biomarkers can help tailor treatment plans to individual patients, improving their chances of successful recovery.
Editorial: reviews | 2023-2024
Rurek M, Czyż J, Heleniak Z, Niedźwiedzka-Rystwej P, Nowak WN, Paw M and Wnuk D
An analysis of epidemiological characteristics of microvascular complications and comorbidities among type 1 diabetes patients
Lewicka M, Korzeniowska-Dyl I, Moczulski D, Woźniak-Kosek A, Zawadzka M and Henrykowska G
Epidemiological analysis of medical data of patients with type 1 diabetes (T1DM) and disease complications treated in hospital.
Effect of restricted feeding and refeeding on the compensatory growth and serum metabolites of juvenile Siberian sturgeon ()
Falahatkar B, Razgardani Sharahi A, Nosrati Movafagh A and Moludinia B
During the rearing period, fish may be exposed to fasting due to low or high temperatures, transportation, handling, and other stressors, while they may catch-up the growth differently after supplying the feed. The aim of this study was to investigate the compensatory growth (CG) response of juvenile Siberian sturgeon after restricted feeding. In the first phase (60 days), triplicate groups of fish were subjected to feed restriction (25%, 50%, and 75% of the amount needed to reach satiation, respectively) or satiation feeding (control) and in the second phase all treatment groups were fed to satiation for an additional 60 days. Growth performance was measured during the two phases and blood samples were collected at the end of the second phase to measure blood biochemical indices. At the end of the first phase of the experiment, as expected, the control group showed the highest mean body weight, followed by the 75%, 50% and 25% satiation fed groups ( < 0.05). However, at the end of the second phase, the final body weights were not significantly different between the groups ( > 0.05), while some of the growth performance improved in the 25% satiation fed group ( < 0.05). At the end of the second phase, serum metabolites except for glucose and cholesterol were significantly different among treatment groups, with the highest levels in the control group. Feed restriction significantly lowered hematocrit, total protein and triglyceride levels especially in the 25% satiation fed group ( < 0.05). The results showed that juvenile Siberian sturgeon could tolerate feed restriction without any significant negative impacts on the majority of growth and metabolite indices. In conclusion, using an appropriate feeding regime helps to improve feed efficiency with no physiological impacts on Siberian sturgeon rearing.
Prognostic role of IL-34 in sepsis and sepsis-induced acute lung injury: preliminary results and future directions
Cai R, Ren J, Zhou C, Liu Y, Tang J, Cui W, Yan Y, Xue S and Zhou Y
This study aimed to evaluate the potential of interleukin-34 (IL-34) as a novel biomarker for predicting mortality in sepsis patients, with a specific focus on those with sepsis-induced acute lung injury (ALI).
Diversity of organ-specific plant transcriptomes
Rurek M
Plant transcriptomes comprise nuclear and organellar (mitochondrial and plastid) transcripts expressed by nuclear and organellar genomes, respectively. They are spatiotemporally shaped during development. The aim of this review was to summarize the most relevant transcriptomic responses in various plant organs and tissues in the developmental context. The dynamicity of organ- or tissue-specific transcriptomic responses was discussed based on the complexity and diversity of the recently characterized plant genomes and transcriptomes. Data were taken from high-throughput studies on numerous species, including model, crop and medicinal plant species. Vascular element transcriptomes as well as the root, leaf, flower and seed transcriptomes were exhaustively characterized. Transcriptomic alterations within various tissue and organ-specific transcriptomes employed various gene classes depending on the species, a given organ/tissue and the developmental stage. The specificity of organ-specific transcriptomes related to the over-representation of certain gene families and a plethora of transcription factors was focused. In addition, transcriptomes of medicinal plant species were characterized. The perspectives of medicinal plant species to synthesize valuable secondary metabolites (including quinones, carotenoids, phytoestrogens, terpenoids, steroids, flavonoids, phenolic derivatives, polysaccharides, glycosides, anthocyanins and macrocyclic peptides) were described based on organ transcriptomic patterns. Future research should be broadened by investigation of transcriptomes from field grown plants. Also, the potential of biomedical plants should be better revealed by genetic engineering and genome editing in further biotechnological applications.
Phages as potential life-saving therapeutic option in the treatment of multidrug-resistant urinary tract infections
Zalewska-Piątek B and Nagórka M
Urinary tract infections (UTIs) are among the most common bacterial infections worldwide and increasing antimicrobial resistance (AMR) challenges conventional antibiotic treatments. Phage therapy (PT) has emerged as a promising alternative due to its specificity, safety and efficacy against multidrug-resistant (MDR) pathogens causing infectious diseases. PT demonstrates significant potential in treating chronic and recurrent UTIs, also including catheter-associated infection by reducing bacterial biofilms, delaying catheter blockage, and enhancing antibiotic efficacy when used in combination. Clinical trials and case studies have reported high rates of bacterial eradication and symptom improvement with minimal side effects. Although endotoxin release and immune activation during treatment should continue to be investigated. The aim of this review is to present issues related to the use of phages in the treatment of UTIs of various etiological origins in selected patients, including those with comorbidities, taking into account the legal regulations, safety and effectiveness of this experimental therapy. The growing prevalence of MDR uropathogens highlights the urgent need for alternative therapies, such as those based on phages in order to treat antibiotic-resistant infections and improve patient outcomes. Despite the great potential of PT, its clinical implementation and use of phages as a routine treatment for bacterial infections requires rigorous trials, standardized production protocols and regulatory advancements.
The rare disease burden: a multidimensional challenge
Cyske Z, Radzanowska-Alenowicz E, Rintz E, Gaffke L and Pierzynowska K
Although there no single, widely accepted definition of a "rare disease," this group of disorders includes conditions that affect only a small fraction of the population. A large number of rare diseases is caused by defined molecular defects, predominantly the occurrence of pathogenic variant(s) of genes. Thus, they are classified as "genetic diseases," among which there are many neurodegenerative disorders. Despite a low incidence of each such disease, majority of them are severe and no effective treatment is available. This creates a battery of problems for millions of people suffering from these disease as well as to their relatives and caregivers. However, the set of problems is larger; therefore, in this narrative review we summarize and discuss various kinds of problems caused by rare disease, including severe symptoms of patients, everyday problems of patients and caregivers, loneliness and social exclusion, diagnostic difficulties, unavailability of effective therapies and economic difficulties in introducing orphan drugs, and a complexity of studies on rare diseases due to low availability of biological material and complicated pathomechanisms. The global picture of the complex problems caused by rare diseases is presented.
Optimization of erythritol production through fermentation using molasses as carbon source
Kembaren R, Parikesit AA, Nataniel J, Dharmawan NA, Dungus CM, Angelique P and Aslanzadeh S
Erythritol is a beneficial sugar alcohol that can be used as a sugar substitute for diabetic patients. Erythritol is a bioproduct produced by microorganisms as a response to high osmotic pressure and stress in the growth medium. High concentrations of carbon source substrate can increase the osmotic pressure and provide more nutrient supply for yeast growth and metabolism. Aside from that, an optimal carbon-to-nitrogen (C/N) ratio can also make the erythritol conversion pathway more favorable. Therefore, this research aims to determine the optimal concentrations of molasses as the carbon source, yeast extract as the nitrogen source, and the optimal carbon-to-nitrogen (C/N) ratio to achieve the highest erythritol productivity. The research also seeks to optimize NaCl concentrations and pH while comparing batch and fed-batch fermentation systems to determine which produces a higher erythritol yield. One-Factor-at-A-Time (OFAT) method was used to identify optimal production conditions. The study found that the highest erythritol concentration, 17.48 ± 0.86 g/L, was achieved using 200 g/L of molasses, 7 g/L of yeast extract (200/7), and 25 g/L of NaCl, with a yield mass of 0.262 ± 0.00 g/g and a volumetric productivity of 0.095 ± 0.021 g/Lh. The pH optimization revealed that the best erythritol production occurred within a pH of 5. Furthermore, fed-batch fermentation significantly increased erythritol concentration to 26.52 ± 1.61 g/L, with a yield mass of 0.501 ± 0.032 g/g and a volumetric productivity of 0.158 ± 0.01 g/Lh. These findings emphasize the importance of optimizing carbon source, nitrogen source and NaCl concentration, pH, and fermentation systems, particularly highlighting the benefits of fed-batch fermentation in maximizing erythritol production. These findings provide a solid foundation for improving erythritol yields for industrial applications.
Effects of low concentrations of fatty acids on depend on the kind of culture medium and incubation temperature
Stencel B, Zielenkiewicz M and Grabowski Ł
Fatty acids play important, yet different roles in bacterial physiology, specifically their growth, either stimulating or inhibiting this parameter which are of biotechnological importance. Here, we present results showing to what degree short- and medium-chain fatty acids (butyric acid (butanoic acid, C4:0); caproic acid (hexanoic acid, C6:0); caprylic acid (octanoic acid, C8:0)), used at relatively low concentrations (in a range of μg/mL, contrary to previously reported mg/mL which revealed inhibitory effects on bacterial growth) affect growth of K-12 (MG1655 laboratory strain) depending on various conditions. In rich medium (LB) positive effects of all tested fatty acids on growth were observed, while temperature of incubation (growth at 25 °C and 37 °C was assessed) modulated these effects. In contrast, a slight but significant growth inhibition by fatty acids was observed in a minimal medium (M9) supplemented with glucose. Nonetheless, in minimal medium containing acetate, the effects of these compounds varied, being either positive or negative depending on their concentrations. No measurable bacterial growth was observed in the case of the presence of any tested fatty acids when primary carbon source (glucose or acetate) was removed from a minimal medium before addition of butyric acid, caproic acid or caprylic acid. Our results indicated that effects of low concentrations of fatty acids on cells depend on growth conditions of bacterial cultures. This may be of biotechnological importance, especially for modulating growth by using different compositions of media and incubation temperatures.