Biological membranes are complex structures whose structure and dynamics are modulated by various biomolecules, including ionic and sterol-like compounds. In this study, we investigated the molecular interactions of magnesium phosphate, in the absence and presence of vitamin D2, with simplified models of biological membranes composed of dipalmitoylphosphatidylcholine (DPPC). We aimed to elucidate their individual and combined effects on the order and dynamics (fluidity) of the hydrophobic part and the interfacial region using Fourier Transform Infrared (FTIR) spectroscopy. Our findings show that the phase transition temperature of the model membrane is not measurably affected by the presence of magnesium phosphate and/or vitamin D2. Our results also demonstrate that magnesium phosphate disrupts membrane integrity by decreasing the order of the pure DPPC and increasing the flexibility of the acyl chains in the deep interior of the bilayer, but, interestingly, it decreases membrane fluidity. These contradictory results on the order and dynamics of DPPC suggest a magnesium phosphate-induced phase separation in the membrane. Our findings also reveal that vitamin D2 enhances lipid order and reduces acyl chain mobility of the pure DPPC. In the joint presence of magnesium phosphate and vitamin D2, vitamin D2 counteracts the disordering effects of magnesium phosphate and restores membrane stability. Consequently, it abolishes the magnesium phosphate-induced phase separation. In addition, our findings reveal a decrease in the strength of hydrogen bonding in the interfacial region, which is explained by the presence of free carbonyl groups in all model membrane combinations. Overall, this study advances our understanding of how multivalent ion-phosphate species and hydrophobic micronutrients jointly regulate membrane organization, extending prior findings on free ion-vitamin D interactions to the less-explored case of magnesium phosphate.

Colorectal cancer remains the second leading cause of cancer-related mortality worldwide, with current therapeutic approaches often demonstrating limited efficacy. Nigella sativa L. (NS) seeds, historically valued for their medicinal properties, exhibit promising anticancer potential. This study investigates the molecular effects of NS methanolic extract on CaCo-2 human colon cancer cells, focusing on cellular composition, dynamics, and segregation patterns. Unsupervised chemometric analyses, including principal component and hierarchical cluster analyses, demonstrated a complete separation between control and NS-treated cells, indicating significant molecular divergence, further validated by supervised classification methods. Spectral analysis revealed reductions in unsaturated lipids, proteins, glucose, and DNA levels, along with a shortening of fatty acid acyl chain length. In contrast, saturated lipid and triglyceride content increased, accompanied by enhanced membrane fluidity and lipid disorder, indicating substantial alterations in cellular lipid dynamics and acyl chain flexibility. Furthermore, oxidative stress markers were elevated, as evidenced by increased protein carbonylation, while protein phosphorylation levels declined. NS treatment also induced protein conformational changes, notably an increase in aggregated β-sheet structures, suggesting protein denaturation. These biochemical modifications were strongly associated with NS-enhanced reactive oxygen species (ROS) levels. Overall, this study elucidates the molecular mechanisms underlying the anticancer effects of NS, supporting its potential as an adjunctive therapeutic strategy for colorectal cancer.

Myasthenia Gravis (MG) is a rare neurological disease. Although there are intensive efforts, the underlying mechanism of MG still has not been fully elucidated, and early diagnosis is still a question mark. Diagnostic paraclinical tests are also time-consuming, burden patients financially, and sometimes all test results can be negative. Therefore, rapid, cost-effective novel methods are essential for the early accurate diagnosis of MG. Here, we aimed to determine MG-induced spectral biomarkers from blood serum using infrared spectroscopy. Furthermore, infrared spectroscopy coupled with multivariate analysis methods e.g., principal component analysis (PCA), support vector machine (SVM), discriminant analysis and Neural Network Classifier were used for rapid MG diagnosis. The detailed spectral characterization studies revealed significant increases in lipid peroxidation; saturated lipid, protein, and DNA concentrations; protein phosphorylation; PO2-asym + sym /protein and PO2-sym/lipid ratios; as well as structural changes in protein with a significant decrease in lipid dynamics. All these spectral parameters can be used as biomarkers for MG diagnosis and also in MG therapy. Furthermore, MG was diagnosed with 100% accuracy, sensitivity and specificity values by infrared spectroscopy coupled with multivariate analysis methods. In conclusion, FTIR spectroscopy coupled with machine learning technology is advancing towards clinical translation as a rapid, low-cost, sensitive novel approach for MG diagnosis.

The aim of this study is to reveal the molecular changes accompanying the neuronal hyper-excitability during lipopolysaccharide (LPS)-induced systemic inflammation on rat hippocampus using Fourier transform infrared (FTIR) spectroscopy. For this aim, the body temperature of Wistar albino rats administered LPS or saline was recorded by radiotelemetry. The animals were decapitated when their body temperature began to decrease by 0.5°C after LPS treatment and the hippocampi of them were examined by FTIR spectroscopy. The results indicated that systemic inflammation caused lipid peroxidation, an increase in the amounts of lipids, proteins and nucleic acids, a decrease in membrane order, an increase in membrane dynamics and changes in the secondary structure of proteins. Principal component analysis successfully separated control and LPS-treated groups. In conclusion, significant structural, compositional and functional alterations occur in the hippocampus during systemic inflammation and these changes may have specific characteristics which can lead to neuronal hyper-excitability.

The present study aimed to characterize the changes in macromolecular composition and structure in ileal tissue induced by postoperative prolonged starvation (PS), human breast milk feeding (HM) and commercial formula feeding (CF) for 48 and 72 h (h). Forty-two Wistar albino rats underwent an ileal transection and primary anastomosis and were then divided into six subgroups. Two groups of seven rats were food-deprived for 48 and 72 h with free access to water only in metabolic cages (48 h PS, 72 h PS). Then, two groups of seven rats received early enteral trophic nutrition (EEN) either using HM, and CF at 48 h post-operation (48 h HM, 48 h CF). The other two groups of seven rats received the same trophic enteral nutrition at 72 h post-operation (72 h HM, 72 h CF). An additional seven rats were fed normal rat chow (control), after which the ileal tissues were harvested and freeze-dried overnight. Then sample spectra were recorded by Fourier transform infrared (FTIR) spectroscopy. PS at 48 and 72 h resulted in an increase in the concentration of lipids and a decrease in the concentration of proteins. CF and HM trophic feeding induced a decrease in membrane fluidity and an increase in lipid order. Ileal tissues showed similar compositional and structural changes in lipids and proteins in the PS and CF groups after 48 and 72 h. A marked decrease in nucleic acid concentration was seen in CF at 48 h compared to HM. The human milk feeding groups did not induce any significant alterations and showed compositional and structural data similar to the controls. In conclusion, EEN application seems to be safer when introduced at 48 h rather than 72 h and time of this nutrition is crucial to maintain ileum structure and therefore immunity and well-being. HM-induced trophic nutrition is seen to protect the ileal tissue from significant alterations within lipid and protein compositions, whereas CF caused notable changes. HM is absolutely the best nutritional source for gut health in this animal model.

Myasthenia gravis (MG) is a multifaceted autoimmune disorder affecting the postsynaptic neuromuscular junction. In this study, we examined CD4+ and CD8+ T lymphocyte levels and ratios within peripheral blood mononuclear cells (PBMCs) in MG patients. Additionally, we assessed lymphocytes for the expression of CD71, which functions as a transferrin receptor mediating the uptake of iron into the cells. Building on recent discussions regarding CD20 depletion treatments in MG, we also scrutinized lymphocytes for CD20 expression. Comparative analyses were conducted among healthy controls, newly diagnosed MG patients, those undergoing pyridostigmine treatment alone, and MG patients receiving combination therapies. In the patients, the ratio of CD3+CD4+ T lymphocytes to CD3+ T lymphocytes was found to be decreased compared to the healthy controls, while the ratio of CD3+CD8+ cells to CD3+CD4+ cells increased. An increase in the percentage of CD71-expressing lymphocytes was observed in MG patients compared to the healthy control group, while CD20+ lymphocytes exhibited no statistical changes. Moreover, heightened serum lipid peroxidation levels were found in MG patients. These results suggest a possible relationship between iron metabolism, levels of CD71-expressing cells, and lipid peroxidation in MG. Conversely, pyridostigmine treatment reduced the levels of CD71-expressing cells and lipid peroxidation, suggesting potential immunomodulatory and antioxidant impacts of pyridostigmine in MG, either directly or indirectly.

Background: Diabetes mellitus (DM) can be characterized by over-production and under-utilization of carbohydrates and varying degrees of abnormal lipid and protein metabolism. The complications of diabetes mellitus affect various organs and systems in the body including the reproductive system. Vitamin C (ascorbic acid) is an essential micronutrient for maintaining normal metabolic processes and homeostasis within the human body. In the current study, the diabetes-induced alterations on the nucleic acids of rat testicular tissues and the effects of low and high doses of ascorbic acid administration were investigated using Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) spectroscopy coupled with an unsupervised technique, namely principal component analysis (PCA). Methods: Male Wistar rats were treated with streptozotocin (STZ) to induce DM. One week after STZ administration, the diabetic rats were treated with a low dose of ascorbic acid (15 mg/kg) and a high dose of ascorbic acid (100 mg/kg) for 6 weeks. The dissected testicular tissues were studied by FTIR spectroscopy. PCA was applied to their spectra. Results: This study revealed diabetes-induced global contextual alterations on nucleic acids, particularly RNAs and DNAs in diabetic samples. Low dose ascorbic acid administration was found to be more effective than higher doses in restoring the effect of diabetes on nucleic acids. The PCA results presented a successful discrimination of the diabetic group from the control and Vitamin C treated groups, and showed especially the ameliorative effect of low dose Vitamin C. Conclusion: Low dose Vitamin C was found to be more effective in combating diabetes-induced alterations in nucleic acids. ATRFTIR spectroscopy combined with multivariate data analyses demonstrated the beneficial effect of Vitamin C administration on nucleic acid content of diabetic testicular tissue based on the spectral differences.

Background: As a main micronutrient, Vitamin C is crucial for preserving the body's homeostasis and regular metabolic functions. The goal of this study is to evaluate the impact of Vitamin C on diabetes-induced changes in the lipid content, conformation/structure and dynamics of testicular tissue using Fourier Transform Infrared (FTIR) microspectroscopic technique.Methods: Male Wistar rats were classified into 4 as: control, diabetic, low (15 mg/kg/day) and high (100 mg/kg/day) Vitamin C-treated groups. The animals in the diabetic and treated groups were first given Streptozotocin (STZ). Diabetic animals were chosen according to their blood glucose levels (values equal to or higher than 300 mg/dL). Vitamin C therapy was started 7 days after STZ treatment and continued for 5 weeks, after which the testis tissues were removed and used for FTIR microspectroscopy studies. The spectral parameters that were evaluated included relative saturated and unsaturated lipid contents, unsaturation indices, lipid orders/disorders and membrane fluidity values.Results: There was a significant reduction in saturation levels, lipid acyl chain length, lipid dynamics (p < 0.001 for all of the mentioned parameters), in addition to an increase in unsaturation levels (p < 0.001) as a result of lipid peroxidation and higher lipid order (p < 0.01) in diabetic tissues, compared to the control rat group. Those variations were significantly recovered by an increase in saturated lipid amount, lipid acyl chain length and dynamics (p < 0.01) with a decrease in unsaturated lipid content (p < 0.001) and lipid order (p < 0.01) in the testis of the low dosage of Vitamin C therapy group compared to the diabetic group. Those parameters were taken to close values to the control group by the low dosage of Vitamin C therapy. Even though high dosage of Vitamin C was also successful in enabling recovery from most of the effects of diabetes on the tissue (p < 0.05 for lipid order,p < 0.01 for saturation andp < 0.001 for unsaturation index), it could not overcome the diabetic effects on the membrane dynamics of the testis tissue.Conclusions: Low dosages of Vitamin C can repair the diabetes-induced damage efficiently and protect the cells and the biomembranes against the damage originating from lipid peroxidation in the tissues.

Type I Diabetes is a multisystem disease that causes alterations in carbohydrate, protein, and fat metabolisms due to hyperglycemia. It has an extensive pathology, especially the mechanism involving oxidative stress is still complex. Type I diabetes is correlated with increased formation of free radicals and decreased levels of antioxidant potential. Vitamin C (Vit C) is a powerful antioxidant that participates in antioxidant defense, protecting lipid membranes and proteins from oxidative damage by donating electrons to free radicals. The effect of type I diabetes and the recovery role of Vit C on the structure and composition of the biomolecular content of testicular tissue is still unknown. Therefore, the current study aimed to investigate the alterations in the biomolecules of rat testes due to Streptozotocin (STZ)-induced type I diabetes using Attenuated Total Reflectance (ATR)-Fourier Transform Infrared (FTIR) spectroscopy and histological staining. The results revealed that the biomolecular structure and composition of testicular tissue are highly affected due to the development of diabetes. We obtained decreased saturation levels and increased unsaturation index in the lipids indicating the presence of lipid peroxidation in the diabetic state. The elevated lipid peroxidation levels have been implicated in the pathogenesis of naturally occurring and chemically induced diabetes. On the other hand, the protein content of diabetic rat testicular tissue was shown to decrease considerably, indicating an increase in proteolysis processes. Supporting the ratio of protein structural and conformational change, protein secondary structural components were also found to alter substantially in the diabetic state. Diabetes was also shown to lead to a decrease in the content of nucleic acids compared to proteins. These diabetes-induced alterations were found to be substantially recovered with the administration of Vit C. Although different doses and administration types of Vit C have been reported in the literature, there is no consensus yet. Therefore, we used three different doses of Vit C in our study as high (100 mg/kg/day), medium (50 mg/kg/day) and low (15 mg/kg/day) doses intraperitoneally in the present study, and the medium dose was found to be the most effective in the recovery from the diabetes-induced structural damages on rat testicular tissue. Vit C may have a therapeutic effect to be used as a complementary therapy in the treatment of diabetes.

Background/Aim: Obesity is associated with the structural and functional disorders related to the molecules of the tissues, cells, and membranes. This study aimed to examine the alterations in the secretion of inflammatory cytokines and metabolic factors and structural changes in inguinal (IF) and gonadal (GF) adipose tissues at the molecular level. Materials and Methods: The IF and GF tissues of Berlin Fat Mouse Inbred (BFMI) lines namely BFMI852, BFMI856, BFMI860, BFMI861 obese and DBAJ control mouse lines were used for mRNA expression and Attenuated Total Reflection - Fourier Transform Infrared Spectroscopy (ATR-FTIR) studies. The mRNA levels of inflammatory cytokines including leptin, interleukin 6 (IL-6), tumor necrosis factor-alpha (Tnf-& alpha;), and insulin-like growth factor-1 (Igf-1), and peroxisome proliferator-activated receptor gamma 2 (Ppar & gamma;-2), were investigated using quantitative reverse transcriptase real-time PCR (qRT-PCR). Infrared spectroscopy does not provide information about specific proteins, instead, it gives information about overall (total) proteins, which is called global information. Therefore, in the current study, adequate information about secondary structures of adipose tissues proteins was obtained using artificial neural network (ANN) and secondary derivative-vector normalization methods based on the spectral profiles. Results: According to the mRNA expression studies, high leptin resistance was found in all BFMI lines. Differences were observed in the levels of measured factors except for Igf-1 among BFMI lines. Protein secondary structure studies showed an increase in random coil contents, especially for BFMI860, which indicates denaturation of the proteins. Conclusion: Among the spontaneous obese BFMI mouse lines, the BFMI860 line is the most suitable for obesity studies. Obesity-induced effect on the adipose tissues varies considerably with location, type of adipose tissue, and animal line.

The structural effects of vitamin A‐deficiency were examined on the molecular profiles of biomolecules of male rat hippocampus during prolonged ethanol intake/withdrawal using FT‐IR spectroscopy coupled with chemometrics. Liquid ethanol diet with/without vitamin A was maintained to adult rats for 3‐months. The rats were decapitated at different ethanol withdrawal times and FT‐IR spectra were obtained. Ethanol consumption/withdrawal produced significant changes in proteins' conformations, while having insignificant structural effects on lipids. In vitamin A deficiency, ethanol produced structural changes in lipids by lipid ordering especially in the early‐ethanol withdrawal. Furthermore, an increase in lipid and protein content, saturated/unsaturated lipid ratio, a decrease in nucleic acids content and decrease in membrane fluidity were observed. These changes were less severe in the presence of Vitamin A. This study is clinically important for individuals with vitamin A deficiency because they have to be more cautious when consuming alcohol to protect themselves from cognitive dysfunctions.

Malignant pleural mesothelioma (MPM), an aggressive cancer associated with exposure to fibrous minerals, can only be diagnosed in the advanced stage because its early symptoms are also connected with other respiratory diseases. Hence, understanding the molecular mechanism and the discrimination of MPM from other lung dis-eases at an early stage is important to apply effective treatment strategies and for the increase in survival rate. This study aims to develop a new approach for characterization and diagnosis of MPM among lung diseases from serum by Fourier transform infrared spectroscopy (FTIR) coupled with multivariate analysis. The detailed spectral characterization studies indicated the changes in lipid biosynthesis and nucleic acids levels in the ma-lignant serum samples. Furthermore, the results showed that healthy, benign exudative effusion, lung cancer, and MPM groups were successfully separated from each other by applying principal component analysis (PCA), support vector machine (SVM), and especially linear discriminant analysis (LDA) to infrared spectra.

Although a wide range of drug therapies fighting pathogenic agents have been developed since the late 19th century, infectious diseases such as pneumonia, flu, tuberculosis, AIDS and malaria still cost millions of lives. As per the World Health Organization (WHO) and Center for Infectious Disease Research estimates, the mortality rates of many infectious diseases may have actually worsened over the past few years. Development of new herbal compounds, understanding the effects of interactions between food and herbal medicines, and validating the traditional local combinations of plant use would be sophisticated revenues of research on the therapeutic effects of herbal medicine in infectious diseases. There is certainly a need for further collaborative biological screening of plant extracts in single, or combination forms and further interdisciplinary research in order to understand their interactions with biological systems. Infrared (IR) spectroscopy is a versatile analytical technique that has valuable applications in several areas such as biomedical sciences, pharmacy, engineering, chemistry, biophysics, food, plant science and toxicology. The combination of IR spectroscopy and chemometrics offers fast and powerful techniques for the separation and verification of herbal medicines-disease interactions. IR spectroscopy is widely used for the confirmation (identification), qualitative and quantitative analysis of herbal medicines and pharmaceutical products, and to determine how effective it is in the treatment of diseases. It requires small amounts of samples, and so is relatively nondestructive, accurate and does not require a reagent, so it is more ecofriendly than biochemical processes. There are only a limited number of published studies on the application of FTIR spectroscopy to herbal medicine - infectious disease interactions. Therefore, it is certainly a very promising and open research area.

In December 2019, COVID-19 (2019 coronavirus disease) caused by SARS-CoV-2 started to spread from Wuhan City of China, by affecting countries such as Japan, Thailand, and the Republic of Korea in first place (Zhu et al., 2020).In March 2020, it was reported by the World Health Organization (WHO) that COVID-19 has become a "pandemic" to the whole world 1 .According to WHO data, as of May 15, 2021, more than 161 million people worldwide have been diagnosed with COVID-19, with 1 World Health Organization (WHO) (2020).Advice on the use of masks in the community, during home care and in healthcare settings in the context of the novel coronavirus (2019-nCoV) outbreak: interim guidance [Online].Website https//www.who.int/publications-detail/advice-on-the-use-of-masks-in-thecommunityduring home-care-and-in-healthcare-settings-in-thecontext-of-the-novel-coronavirus-(2019-ncov)-outbreak.[accessed March 9th, 2020].more than 3.3 million deaths reported 2 .SARS-CoV-2 has a genetic affinity with the previous coronaviruses named SARS-CoV and MERS-CoV which have previously caused extremely dreadful health threats within two decades (Zhu et al., 2020).In COVID-19 patients, although it varies from patient to patient, the most common clinical symptoms are sore throat, dry cough, weakness, fever, shortness of breath or breathing difficulties, and body aches.In addition, patients may experience nausea, diarrhoea or runny nose (Xu et al., 2020).In the computerised tomography (CT) scan results of many COVID-19 patients, bilateral, groundglass opacity with multifocal lung lesions have been reported even in the early stage of SARS-CoV-2 infection 2

Traumatic brain injury (TBI) can be defined as a disorder in the function of the brain after a bump, blow, or jolt to the head, or penetrating head injury. Mild traumatic brain injury (mTBI) can cause devastating effects, such as the initiation of long-term neurodegeneration in brain tissue. In the current study, the effects of mTBI were investigated on rat brain regions; cortex (Co) and corpus callosum (CC) after 24 h (subacute trauma) by Fourier transform infrared (FTIR) imaging and immunohistochemistry (IHC). IHC studies showed the formation of amyloid-β (Aβ) plaques in the cortex brain region of mTBI rats. Moreover, staining of myelin basic protein presented the shearing of axons in CC region in the same group of animals. According to FTIR imaging results, total protein and lipid content significantly decreased in both Co and CC regions in mTBI group compared to the control. Due to this significant decrease in both lipid and protein content, remarkable consistency in lipid/protein band ratio in mTBI and control group, was observed. Significant decrease in methyl content and a significant increase in olefinic content were observed in Co and CC regions of mTBI rat brain tissues. Classification amongst distinguishable groups was performed using principal component analysis (PCA) and hierarchical clustering (HCA). This study established the prospective of FTIR imaging for assessing biochemical changes due to mTBI with high sensitivity, precision and high-resolution.

From the beginning of the COVID-19 coronavirus pandemic in December of 2019, the disease has infected millions of people worldwide and caused hundreds of thousands of deaths. Since then, several vaccines have been developed. One of those vaccines is inactivated CoronaVac-Sinovac COVID-19 vaccine. In this proof of concept study, we first aimed to determine CoronaVac-induced biomolecular changes in healthy human serum using infrared spectroscopy. Our second aim was to see whether the vaccinated group can be separated or not from the non-vaccinated group by applying chemometric techniques to spectral data. The results revealed that the vaccine administration induced significant changes in some functional groups belonging to lipids, proteins and nucleic acids. In addition, the non-vaccinated and vaccinated groups were successfully separated from each other by principal component analysis (PCA) and linear discriminant analysis (LDA). This proof-of-concept study will encourage future studies on CoronaVac as well as other vaccines and will lead to make a comparison between different vaccines to establish a better understanding of the vaccination outcomes on serum biomolecules.

Since COVID-19 pandemic has been continuously rising and spreading, several original contributions and review articles on COVID-19 started to appear in the literature. The review articles are mainly focus on the current status of the pandemic along with current status of the corona diagnosis and treatment process. Due to some disadvantages of the currently used methods, the improvement on the novel promising diagnosis and treatment methods of corona virus is very important issue. In this review, after briefly discussing the status of current diagnosis and treatment methods, we present to the scientific community, novel promising methods in the diagnosis and treatment of COVID-19. As with other novel approaches, first, the diagnosis potential of mass spectroscopy and optical spectroscopic methods such as UV/visible, infrared, and Raman spectroscopy coupled with chemometrics will be discussed for the corona virus infected samples based on the relevant literature. In vibrational spectroscopy studies, due to complexity of the data, multivariate analysis methods are also applied to data. The application of multivariate analysis tools that can be used to extract useful information from the data for diagnostic and characterisation purposes is also included in this review. The reviewed methods include hierarchical cluster analysis, principal component analysis, linear and quadratic discriminant analysis, support vector machine algorithm, and one form of neural networks namely deep learning method. Second, novel treatment methods such as photodynamic therapy and the use of nanoparticles in the in-corona virus therapy will be discussed. Finally, the advantages of novel promising diagnosis and treatment methods in COVID-19, over standard methods will be discussed. One of the main aims of this paper is to encourage the scientific community to explore the potential of this novel tools for their use in corona virus characterization, diagnosis, and treatment.

Traumatic brain injury (TBI) is the main cause of disability and mortality in individuals under the age of 45 years. Elucidation of the molecular and structural alterations in brain tissue due to TBI is crucial to understand secondary and long-term effects after traumatic brain injury, and to develop and apply the correct therapies. In the current study, the molecular effects of TBI were investigated in rat brain at 24 h and 1 month after the injury to determine acute and chronic effects, respectively by Fourier transform infrared imaging. This study reports the time-dependent contextual and structural effects of TBI on hippocampal brain tissue. A mild form of TBI was induced in 11-week old male Sprague Dawley rats by weight drop. Band area and intensity ratios, band frequency and bandwidth values of specific spectral bands showed that TBI causes significant structural and contextual global changes including decrease in carbonyl content, unsaturated lipid content, lipid acyl chain length, membrane lipid order, total protein content, lipid/protein ratio, besides increase in membrane fluidity with an altered protein secondary structure and metabolic activity in hippocampus 24 h after injury. However, improvement and/or recovery effects in these parameters were observed at one month after TBI.

Heavy metal acclimated bacteria are profoundly the preferred choice for bioremediation studies. Bacteria get acclimated to toxic concentrations of heavy metals by induction of specific enzymes and genetic selection favoring new metabolic abilities leading to activation of one or several of resistance mechanisms creating bacterial populations with differences in resistance profile and/or level. Therefore, to use in bioremediation processes, it is important to discriminate acclimated bacterial populations and choose a more resistant strain. In this study, we discriminated heavy metal acclimated bacteria by using Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) spectroscopy and multivariate analysis methods namely Hierarchical Cluster Analysis (HCA), Principal Component Analysis (PCA) and Soft Independent Modeling of Class Analogy (SIMCA). Two acclimation methods, acute and gradual, were used which cause differences in molecular changes resulting in bacterial populations with different molecular and resistance profiles. Brevundimonas sp., Gordonia sp., and Microbacterium oxydans were exposed to the toxic concentrations of Cd (30 μg/ml) or Pb (90 μg/ml) by using broth medium as a growth media. Our results revealed that PCA and HCA clearly discriminated the acute-acclimated, gradual-acclimated, and control bacteria from each other in protein, carbohydrate, and whole spectral regions. Furthermore, we classified acclimated (acute and gradual) and control bacteria more accurately by using SIMCA with 99.9% confidence. This study demonstrated that heavy metal acclimated and control group bacteria can be discriminated by using chemometric analysis of FTIR spectra in a powerful, cost-effective, and handy way. In addition to the determination of the most appropriate acclimation procedure, this approach can be used in the detection of the most resistant bacterial strains to be used in bioremediation studies.