Regulatory mechanisms of lipid biosynthesis in microalgae

Strategies for producing high value small molecules in microalgae

Eukaryotic microalgae are a diverse group of organisms that can be used for the sustainable production of a wide range of high value compounds, including lipids, flavours and dyes, bioplastics, and cosmetics. Optimising total biomass production often does not lead to optimal product yield and more sophisticated biphasic growth strategies are needed, introducing specific stresses to induce product synthesis. Genetic tools have been used to increase yields of natural products or to introduce new pathways to algae, and wider deployment of these tools offers promising routes for commercial production of high value compounds utilising minimal inputs.

Mechanistic insights into the potential application of Scenedesmus strains towards the elimination of antibiotics from wastewater

Scenedesmus strains have been reported to have the potential to tolerate and bioremediate antibiotic pollutants through bioadsorption, bioaccumulation, and biodegradation mechanism from the wastewater medium. Hormesis effects have been observed in the Scenedesmus strains when exposed to different concentrations of antibiotic pollutants. Lower concentrations of antibiotic pollutants are known to trigger growth-stimulating effects by triggering adaptive responses such as increased metabolic activity and activating detoxifying mechanisms leading to the biotransformation pathway. The present review examines the existing body of information pertaining to biotransformation pathways tolerance, hormesis effects, and efficiency of Scenedesmus strains in removing various antibiotic pollutants. This review provides critical information on using Scenedesmus species to treat antibiotic-polluted wastewater by boosting growth and resilience tolerant doses and avoiding toxicity at higher doses.

Nitrogen starvation leads to TOR kinase-mediated downregulation of fatty acid synthesis in the algae Chlorella sorokiniana and Chlamydomonas reinhardtii

BACKGROUND

When subject to stress conditions such as nutrient limitation microalgae accumulate triacylglycerol (TAG). Fatty acid, a substrate for TAG synthesis is derived from de novo synthesis or by membrane remodeling. The model industrial alga Chlorellasorokiniana accumulates TAG and other storage compounds under nitrogen (N)-limited growth. Molecular mechanisms underlying these processes are still to be elucidated.

RESULT

Previously we used transcriptomics to explore the regulation of TAG synthesis in C. sorokiniana. Surprisingly, our analysis showed that the expression of several key genes encoding enzymes involved in plastidic fatty acid synthesis are significantly repressed. Metabolic labeling with radiolabeled acetate showed that de novo fatty acid synthesis is indeed downregulated under N-limitation. Likewise, inhibition of the Target of Rapamycin kinase (TOR), a key regulator of metabolism and growth, decreased fatty acid synthesis. We compared the changes in proteins and phosphoprotein abundance using a proteomics and phosphoproteomics approach in C. sorokiniana cells under N-limitation or TOR inhibition and found extensive overlap between the N-limited and TOR-inhibited conditions. We also identified changes in the phosphorylation status of TOR complex proteins, TOR-kinase, and RAPTOR, under N-limitation. This indicates that TOR signaling is altered in a nitrogen-dependent manner. We find that TOR-mediated metabolic remodeling of fatty acid synthesis under N-limitation is conserved in the chlorophyte algae Chlorella sorokiniana and Chlamydomonas reinhardtii.

CONCLUSION

Our results indicate that under N-limitation there is significant metabolic remodeling, including fatty acid synthesis, mediated by TOR signaling. This process is conserved across chlorophyte algae. Using proteomic and phosphoproteomic analysis, we show that N-limitation affects TOR signaling and this in-turn affects the metabolic status of the cells. This study presents a link between N-limitation, TOR signaling and fatty acid synthesis in green-lineage.

Application of Biosurfactants in Medical Sciences

Biosurfactants derived from microorganisms have attracted widespread attention in scientific research due to their unique surface activity, low toxicity, biodegradability, antibacterial properties, and stability under extreme conditions. Biosurfactants are widely used in many fields, such as medicine, agriculture, and environmental protection. Therefore, this review aims to comprehensively review and analyze the various applications of biosurfactants in the medical field. The central roles of biosurfactants in crucial medical areas are explored, like drug delivery, induction of tumor cell differentiation or death, treating bacterial and viral effects, healing wounds, and immune regulation. Moreover, a new outlook is introduced on optimizing the capabilities of biosurfactants through modification and gene recombination for better use in medicine. The current research challenges and future research directions are described, aiming to provide valuable insights for continuous study of biosurfactants in medicine.

Engineering Fatty Acid Biosynthesis in Microalgae: Recent Progress and Perspectives

Microalgal lipids hold significant potential for the production of biodiesel and dietary supplements. To enhance their cost-effectiveness and commercial competitiveness, it is imperative to improve microalgal lipid productivity. Metabolic engineering that targets the key enzymes of the fatty acid synthesis pathway, along with transcription factor engineering, are effective strategies for improving lipid productivity in microalgae. This review provides a summary of the advancements made in the past 5 years in engineering the fatty acid biosynthetic pathway in eukaryotic microalgae. Furthermore, this review offers insights into transcriptional regulatory mechanisms and transcription factor engineering aimed at enhancing lipid production in eukaryotic microalgae. Finally, the review discusses the challenges and future perspectives associated with utilizing microalgae for the efficient production of lipids.

Effects of culture temperature and light regimes on biomass and lipid accumulation of Chlamydomonas reinhardtii under carbon-rich and nitrogen-limited conditions

This study investigated the impacts of various culture temperatures and light regimes on growth and biochemical constituents of Chlamydomonas reinhardtii under carbon-supply and nitrogen-limited conditions to improve oil production in algal cells. Results displayed that under a 30 ℃ and 150 μE/m2/s regime, there was a significant increase in biomass, total lipids, and lipid productivity. Specifically, these parameters reached 1.83 g/L, 36.25 %, and 130.73 mg/L/d, respectively. Remarkably, prolonging the photoperiod further enhanced the aforementioned three parameters, reaching peak levels of 1.92 g/L, 41.10 %, and 157.54 mg/L/d, respectively, recorded at a 24/0h photoperiod. Compared with cultures grown under normal conditions, these values displayed increments of 1.21-fold, 74.88 %, and 3.01-fold, respectively. Additionally, under optimal conditions, the soluble sugar content reached 79.72 mg/g, and the biodiesel properties were improved. These findings indicate that moderately increasing temperature, light intensity, and photoperiod could achieve the co-production of biomass, lipids, and sugars in C. reinhardtii.

Influence of salinity, nitrogen and phosphorus concentrations on the physiological and biochemical characteristics of two Chlorophyceae isolated from Fez freshwater, Morocco

Microalgae are widely exploited for numerous biotechnology applications, including biofuels. In this context, Chlamydomonas debaryana and Chlorococcum sp. were isolated from Fez freshwater (Morocco), and their growth and lipid and carbohydrate production were assessed at different concentrations of NaCl, NaNO3, and K2HPO4. The results indicate a small positive variation in growth parameters linked to nutrient enrichment, with no considerable variation in carbohydrate and lipid levels in both algae. Moreover, a negative variation was recorded at increased salinity and nutrient limitation, accompanied by lipid and carbohydrate accumulation. Chlorococcum sp. showed better adaptation to salt stress below 200 mM NaCl. Furthermore, its growth and biomass productivity were strongly reduced by nitrogen depletion, and its lipid production reached 47.64% DW at 3.52 mM NaNO3. As for Chlamydomonas debaryana, a substantial reduction in growth was induced by nutrient depletion, a maximal carbohydrate level was produced at less than 8.82 mM NaNO3 (40.59% DW). The effect of phosphorus was less significant. However, a concentration of 0.115 mM K2HPO4 increased lipid and carbohydrate content without compromising biomass productivity. The results suggest that growing the two Chlorophyceae under these conditions seems interesting for biofuel production, but the loss of biomass requires a more efficient strategy to maximize lipid and carbohydrate accumulation without loss of productivity.

Towards Lipid from Microalgae: Products, Biosynthesis, and Genetic Engineering

Microalgae can convert carbon dioxide into organic matter through photosynthesis. Thus, they are considered as an environment-friendly and efficient cell chassis for biologically active metabolites. Microalgal lipids are a class of organic compounds that can be used as raw materials for food, feed, cosmetics, healthcare products, bioenergy, etc., with tremendous potential for commercialization. In this review, we summarized the commercial lipid products from eukaryotic microalgae, and updated the mechanisms of lipid synthesis in microalgae. Moreover, we reviewed the enhancement of lipids, triglycerides, polyunsaturated fatty acids, pigments, and terpenes in microalgae via environmental induction and/or metabolic engineering in the past five years. Collectively, we provided a comprehensive overview of the products, biosynthesis, induced strategies and genetic engineering in microalgal lipids. Meanwhile, the outlook has been presented for the development of microalgal lipids industries, emphasizing the significance of the accurate analysis of lipid bioactivity, as well as the high-throughput screening of microalgae with specific lipids.

Enhancing docosahexaenoic acid production in Aurantiochytrium species using atmospheric and room temperature plasma mutagenesis and comprehensive multi-omics analysis

Aurantiochytrium sp. belongs to marine heterotrophic single-cell protist, which is an important decomposer in marine ecosystem. Aurantiochytrium sp. has gained notoriety because of its ability to accumulate high-value docosahexaenoic acid (DHA), but the key factors of DHA synthesis were unclear at present. In this study, Atmospheric and Room Temperature Plasma technology was applied to the mutagenic breeding of Aurantiochytrium sp., and transcriptomics and proteomics were adopted to analyze the DHA-biosynthesis mechanism. According to the growth and DHA accumulation profiles, the mutant strain Aurantiochytrium sp. R2A35 was selected. The DHA content in total lipids was greatly improved from 49.39 % of the wild strain R2 to 63.69 % of the mutant strain. Moreover, the DHA content in the biomass of Aurantiochytrium sp. R2A35 as 39.72 % was the highest DHA productivity reported so far. The differentially expressed genes distinguished from transcriptome and the TMT-identified differential proteins distinguished from proteome confirmed that the expression of acetyl-CoA carboxylase and ketoacyl reductase was up-regulated by 4.78-fold and 6.95-fold, respectively and the fatty acid synthase was concurrently down-regulated by 2.79-fold, so that more precursor was transported to the polyketide synthase pathway, thereby increasing the DHA yield in Aurantiochytrium sp. R2A35. This research would provide reference for the DHA metabolism process and contribute to the understanding of the decomposer - Aurantiochytrium sp. in marine ecosystems.

Progress of stimulus responsive nanosystems for targeting treatment of bacterial infectious diseases

In recent decades, due to insufficient concentration at the lesion site, low bioavailability and increasingly serious resistance, antibiotics have become less and less dominant in the treatment of bacterial infectious diseases. It promotes the development of efficient drug delivery systems, and is expected to achieve high absorption, targeted drug release and satisfactory therapy effects. A variety of endogenous stimulation-responsive nanosystems have been constructed by using special infection microenvironments (pH, enzymes, temperature, etc.). In this review, we firstly provide an extensive review of the current research progress in antibiotic treatment dilemmas and drug delivery systems. Then, the mechanism of microenvironment characteristics of bacterial infected lesions was elucidated to provide a strong theoretical basis for bacteria-targeting nanosystems design. In particular, the discussion focuses on the design principles of single-stimulus and dual-stimulus responsive nanosystems, as well as the use of endogenous stimulus-responsive nanosystems to deliver antimicrobial agents to target locations for combating bacterial infectious diseases. Finally, the challenges and prospects of endogenous stimulus-responsive nanosystems were summarized.

Unlocking the potential of microalgae cultivated on wastewater combined with salinity stress to improve biodiesel production

Microalgae have the potential as a source of biofuels due to their high biomass productivity and ability to grow in a wide range of conditions, including wastewater. This study investigated cultivating two microalgae species, Oocystis pusilla and Chlorococcus infusionum, in wastewater for biodiesel production. Compared to Kühl medium, KC medium resulted in a significant fold increase in cellular dry weight production for both O. pusilla and C. infusionum, with an increase of 1.66 and 1.39, respectively. A concentration of 100% wastewater resulted in the highest growth for O. pusilla, with an increase in biomass and lipid content compared to the KC medium. C. infusionum could not survive in these conditions. For further increase in biomass and lipid yield of O. pusilla, different total dissolved solids (TDS) levels were used. Maximum biomass and lipid productivities were achieved at 3000 ppm TDS, resulting in a 28% increase in biomass (2.50 g/L) and a 158% increase in lipid yield (536.88 mg/g) compared to KC medium. The fatty acid profile of O. pusilla cultivated on aerated wastewater at 3000 ppm TDS showed a high proportion of desirable saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) for biodiesel production. Cultivating microalgae in wastewater for biodiesel production can be cost-effective, especially for microalgae adapted to harsh conditions. It could be concluded that O. pusilla is a promising candidate for biodiesel production using wastewater as a growth medium, as it has high biomass productivity and lipid yield, and its fatty acid profile meets the standard values of American and European biodiesel standards. This approach offers a sustainable and environmentally friendly solution for producing biofuels while reducing the environmental impact of wastewater disposal.

Fundamental alteration of cellular biochemicals from attached microalgae onto palm kernel expeller waste upon optimizing the growth environment in forming adhesion complex

Changing the growth environment for microalgae can overall lead to the fundamental alteration in cellular biochemicals whilst attaching onto palm kernel expeller (PKE) waste to form adhesion complex in easing harvesting at stationary growth phase. This study had initially optimized the PKE dosage, light intensity and photoperiod in maximizing the attached microalgal productivity being attained at 0.72 g/g day. Lipid content increased progressively from pH 3 to pH 11, with the highest value observed at pH 11. Meanwhile, in terms of protein and carbohydrate contents, the highest values were obtained by cultivation medium of pH 5 with 9.92 g and 17.72 g, respectively followed by pH 7 with 9.16 g and 16.36 g, respectively. Moreover, the findings also suggested that the low pH mediums utilized polar interactions in the formation of complexes between PKE and microalgae, whereas at higher pH levels, the non-polar interactions became more significant. The work of attachment was thermodynamically favourable towards the attachment formation with values greater than zero which was also aligned with the microscopic surface topography, i.e., revealing a clustering pattern of microalgae colonizing the PKE surface. These findings contribute to comprehensive understanding of optimizing growth condition and harvesting strategy of attached microalgae in attaining the cellular biochemical components, facilitating the development of efficient and sustainable bioresource utilization.

LASSO Regression with Multiple Imputations for the Selection of Key Variables Affecting the Fatty Acid Profile of Nannochloropsis oculata

The marine microalga Nannochloropsis oculata has garnered significant interest as a potential source of lipids, both for biofuel and nutrition, containing significant amounts of C16:0, C16:1, and C20:5, n-3 (EPA) fatty acids (FA). Growth parameters such as temperature, pH, light intensity, and nutrient availability play a crucial role in the fatty acid profile of microalgae, with N. oculata being no exception. This study aims to identify key variables for the FA profile of N. oculata grown autotrophically. To that end, the most relevant literature data were gathered and combined with our previous work as well as with novel experimental data, with 121 observations in total. The examined variables were the percentages of C14:0, C16:0, C16:1, C18:1, C18:2, and C20:5, n-3 in total FAs, their respective ratios to C16:0, and the respective content of biomass in those fatty acids in terms of ash free dry weight. Many potential predictor variables were collected, while dummy variables were introduced to account for bias in the measured variables originating from different authors as well as for other parameters. The method of multiple imputations was chosen to handle missing data, with limits based on the literature and model-based estimation, such as using the software PHREEQC and residual modelling for the estimation of pH. To eliminate unimportant predictor variables, LASSO (Least Absolute Shrinkage and Selection Operator) regression analysis with a novel definition of optimal lambda was employed. LASSO regression identified the most relevant predictors while minimizing the risk of overfitting the model. Subsequently, stepwise linear regression with interaction terms was used to further study the effects of the selected predictors. After two rounds of regression, sparse refined models were acquired, and their coefficients were evaluated based on significance. Our analysis confirms well-known effects, such as that of temperature, and it uncovers novel unreported effects of aeration, calcium, magnesium, and manganese. Of special interest is the negative effect of aeration on polyunsaturated fatty acids (PUFAs), which is possibly related to the enzymatic kinetics of fatty acid desaturation under increased oxygen concentration. These findings contribute to the optimization of the fatty acid profile of N. oculata for different purposes, such as production of, high in PUFAs, food or feed, or production of, high in saturated and monounsaturated FA methyl esters (FAME), biofuels.

Algae Incorporation and Nutritional Improvement: The Case of a Whole-Wheat Pasta

Algae contain high-quality proteins, dietary fiber, minerals, and phenolic compounds, making them promising alternative ingredients. Since pasta is consumed worldwide, it can be an effective vehicle for incorporating algae. This study compares the nutritional and antioxidant composition of whole-wheat pasta without and with enrichment of an algae mixture (containing Himanthalia elongata and Spirulina) and ascertains the influence of the cooking procedure on their features. Spirulina and H. elongata were also analyzed in parallel for comparison purposes. Macronutrients, chlorides and salt, total and free amino acid profiles, and antioxidant properties (total phenolic content and ferric reducing antioxidant power) were analyzed using AOAC, Mohr's, high performance liquid chromatography with fluorescence detection, and spectrophotometric methods, respectively. The results show a significant increase in fat (70.4%), protein (29.7%), ash (26.5%), and total amino acid (except for serine, tryptophan, isoleucine, and threonine) contents in the raw algae-enriched pasta. The antioxidant activity was also higher (4.15 versus 3.68 g ferrous sulfate eq./g dw, respectively). After cooking, protein, dietary fiber, total amino acids (except threonine) and antioxidant activity were stable in the algae-enriched pasta. Thus, algae can be an excellent ingredient for food applications with health benefits.

Diagnostic ability of deep learning in detection of pancreatic tumour

Pancreatic cancer is associated with higher mortality rates due to insufficient diagnosis techniques, often diagnosed at an advanced stage when effective treatment is no longer possible. Therefore, automated systems that can detect cancer early are crucial to improve diagnosis and treatment outcomes. In the medical field, several algorithms have been put into use. Valid and interpretable data are essential for effective diagnosis and therapy. There is much room for cutting-edge computer systems to develop. The main objective of this research is to predict pancreatic cancer early using deep learning and metaheuristic techniques. This research aims to create a deep learning and metaheuristic techniques-based system to predict pancreatic cancer early by analyzing medical imaging data, mainly CT scans, and identifying vital features and cancerous growths in the pancreas using Convolutional Neural Network (CNN) and YOLO model-based CNN (YCNN) models. Once diagnosed, the disease cannot be effectively treated, and its progression is unpredictable. That's why there's been a push in recent years to implement fully automated systems that can sense cancer at a prior stage and improve diagnosis and treatment. The paper aims to evaluate the effectiveness of the novel YCNN approach compared to other modern methods in predicting pancreatic cancer. To predict the vital features from the CT scan and the proportion of cancer feasts in the pancreas using the threshold parameters booked as markers. This paper employs a deep learning approach called a Convolutional Neural network (CNN) model to predict pancreatic cancer images. In addition, we use the YOLO model-based CNN (YCNN) to aid in the categorization process. Both biomarkers and CT image dataset is used for testing. The YCNN method was shown to perform well by a cent percent of accuracy compared to other modern techniques in a thorough review of comparative findings.

Detoxifying the heavy metals: a multipronged study of tolerance strategies against heavy metals toxicity in plants

Heavy metal concentrations exceeding permissible limits threaten human life, plant life, and all other life forms. Different natural and anthropogenic activities emit toxic heavy metals in the soil, air, and water. Plants consume toxic heavy metals from their roots and foliar part inside the plant. Heavy metals may interfere with various aspects of the plants, such as biochemistry, bio-molecules, and physiological processes, which usually translate into morphological and anatomical changes. They use various strategies to deal with the toxic effects of heavy metal contamination. Some of these strategies include restricting heavy metals to the cell wall, vascular sequestration, and synthesis of various biochemical compounds, such as phyto-chelators and organic acids, to bind the free moving heavy metal ions so that the toxic effects are minimized. This review focuses on several aspects of genetics, molecular, and cell signaling levels, which integrate to produce a coordinated response to heavy metal toxicity and interpret the exact strategies behind the tolerance of heavy metals stress. It is suggested that various aspects of some model plant species must be thoroughly studied to comprehend the approaches of heavy metal tolerance to put that knowledge into practical use.

Reduction of rupture risk in ICA aneurysms by endovascular techniques of coiling and stent: numerical study

The initiation, growth, and rupture of cerebral aneurysms are directly associated with Hemodynamic factors. This report tries to disclose effects of endovascular technique (coiling and stenting) on the quantitative intra-aneurysmal hemodynamic and the rupture of cerebral aneurysms. In this paper, Computational Fluid Dynamic are done to investigate and compare blood hemodynamic inside aneurysm under effects of deformation (due to stent) and coiling of aneurysm. The blood stream inside the sac of aneurysm as well as pressure and OSI distribution on the aneurysm wall are compared in nine cases and results of two distinctive cases are compared and reported. Obtained results specifies that the mean WSS is reduced up to 20% via coiling of the aneurysm while the deformation of the aneurysm (applying stent) could reduce the mean WSS up to 71%. In addition, comparison of the blood hemodynamic shows that the blood bifurcation occurs in the dome of aneurysm when endovascular technique for the treatment is not applied. It is found that the bifurcation occurs at ostium section when ICA aneurysm is deformed by the application of stent. The impacts of coiling are mainly limited since the blood flow entrance is not limited in this technique and WSS is not reduced substantial. However, usage of stent deforms the aneurysm angle with the orientation of parent vessel and this reduces blood velocity at entrance of the ostium and consequently, WSS is decreased when deformation of the aneurysm fully occurs. These qualitative procedures provide a preliminary idea for more profound quantitative examination intended for assigning aneurysm risk of upcoming rupture.

Investigation of the stent induced deformation on hemodynamic of internal carotid aneurysms by computational fluid dynamics

Application of the stent for treatment of the internal carotid artery (ICA) aneurysms has been extensively increased in recent decades. In the present work, stent-induced deformations of the parent vessel of ICA aneurysms are fully investigated. This study tries to visualize blood stream and calculated hemodynamic factors inside the four ICA aneurysms after deformations of parent vessel. For the simulation of the non-Newtonian blood stream, computational fluid dynamic is applied with one-way Fluid-Solid interaction (FSI) approach. Four ICA aneurysms with different ostium sizes and neck vessel angle are selected for this investigation. Wall shear stress on wall of aneurysm is analyzed in two angles of deformation due to application of the stent. Blood flow investigation shows that the deformation of the aneurysm limited blood entrance to the sac region and this decreases the blood velocity and consequently oscillatory shear index (OSI) on the sac wall. It is also observed that the stent-induced deformation is more effective on those cases with extraordinary OSI values on aneurysm wall.

Microalgal polyunsaturated fatty acids: Hotspots and production techniques

Algae play a crucial role in the earth’s primary productivity by producing not only oxygen but also a variety of high-value nutrients. One such nutrient is polyunsaturated fatty acids (PUFAs), which are accumulated in many algae and can be consumed by animals through the food chain and eventually by humans. Omega-3 and omega-6 PUFAs are essential nutrients for human and animal health. However, compared with plants and aquatic sourced PUFA, the production of PUFA-rich oil from microalgae is still in the early stages of exploration. This study has collected recent reports on algae-based PUFA production and analyzed related research hotspots and directions, including algae cultivation, lipids extraction, lipids purification, and PUFA enrichment processes. The entire technological process for the extraction, purification and enrichment of PUFA oils from algae is systemically summarized in this review, providing important guidance and technical reference for scientific research and industrialization of algae-based PUFA production.

Influence of stent-induced vessel deformation on hemodynamic feature of bloodstream inside ICA aneurysms

One of the effective treatment options for intracranial aneurysms is stent-assisted coiling. Though, previous works have demonstrated that stent usage would result in the deformation of the local vasculature. The effect of simple stent on the blood hemodynamics is still uncertain. In this work, hemodynamic features of the blood stream on four different ICA aneurysm with/without interventional are investigated. To estimate the relative impacts of vessel deformation, four distinctive ICA aneurysm is simulated by the one-way FSI technique. Four hemodynamic factors of aneurysm blood velocity, wall pressure and WSS are compared in the peak systolic stage to disclose the impact of defamation by the stent in two conditions. The stent usage would decrease almost all of the mentioned parameters, except for OSI. Stenting reduces neck inflow rate, while the effect of interventional was not consistent among the aneurysms. The deformation of an aneurysm has a strong influence on the hemodynamics of an aneurysm. This outcome is ignored by most of the preceding investigations, which focused on the pre-interventional state for studying the relationship between hemodynamics and stents. Present results show that the application of stent without coiling would improve most hemodynamic factors, especially when the deformation of the aneurysm is high enough.

Low dissolved oxygen supply functions as a global regulator of the growth and metabolism of Aurantiochytrium sp. PKU#Mn16 in the early stages of docosahexaenoic acid fermentation

BACKGROUND

Thraustochytrids accumulate lipids with a high content of docosahexaenoic acid (DHA). Although their growth and DHA content are significantly affected by the dissolved oxygen (DO) supply, the role of DO on the transcriptional regulation of metabolism and accumulation of intracellular metabolites remains poorly understood. Here we investigate the effects of three different DO supply conditions (10%, 30%, and 50%) on the fed-batch culture of the Aurantiochytrium PKU#Mn16 strain to mainly reveal the differential gene expressions and metabolite profiles.

RESULTS

While the supply of 10% DO significantly reduced the rates of biomass and DHA production in the early stages of fermentation, it achieved the highest amounts of biomass (56.7 g/L) and DHA (6.0 g/L) on prolonged fermentation. The transcriptome analyses of the early stage (24 h) of fermentation revealed several genes involved in the central carbon, amino acid, and fatty acid metabolism, which were significantly downregulated at a 10% DO level. The comparative metabolomics results revealed the accumulation of several long-chain fatty acids, amino acids, and other metabolites, supporting the transcriptional regulation under the influence of a low oxygen supply condition. In addition, certain genes involved in antioxidative systems were downregulated under 10% DO level, suggesting a lesser generation of reactive oxygen species that lead to oxidative damage and fatty acid oxidation.

CONCLUSIONS

The findings of this study suggest that despite the slow growth and metabolism in the early stage of fermentation of Aurantiochytrium sp. PKU#Mn16, a constant supply of low dissolved oxygen can yield biomass and DHA content better than that with high oxygen supply conditions. The critical information gained in this study will help to further improve DHA production through bioprocess engineering strategies.

Investigation of the substituted-titanium nanocages using computational chemistry

We are investigated substitution effects of titanium heteroatoms on band gap, charge and local reactivity of C_20-nTi_n heterofullerenes (n = 1-5), at different levels and basis sets. The C₁₈Ti_2-2 nanocage is considered as the most kinetically stable species with the widest band gap of 2.86 eV, in which two carbon atoms are substituted by two Ti atoms in equatorial position, individually. The charges on carbon atoms of C₂₀ are roughly zero, while high positive charge (1.256) on the surface of C₁₉Ti₁ prompts this heteofullerene for hydrogen storage. The positive atomic charge on Ti atoms and negative atomic charge on their adjacent C atoms implies that these sites can be influenced more readily by nucleophilic and electrophilic regents, respectively. We examined the usefulness of local reactivity descriptors to predict the reactivity of Ti-C atomic sites on the external surface of the heterofullerenes. The properties determined include Fukui function (F.F.); f (k) and local softness s (k) on the surfaces of the investigated hollow cages. Geometry optimization results reveal that titanium atoms can be comfortably incorporated into the CC network of fullerene. It is most likely associated with the triple-coordination characteristic of titanium atoms, which can well match with the sp²-hybridized carbon bonding structure. According to the values of f (k) and s (k) for the C₁₅Ti₅ heterofullerene; the carbon atoms in the cap regions exhibit a different reactivity pattern than those in the equatorial portion of the heterofullerene. The titanium impurity can significantly improve the fullerene's surface reactivity and it allows controlling their surface properties. The band gap of C_20-nTi_n …..(H₂)_n structures is decreased with increasing n. Hence, C₁₅Ti₅ is found as the best hydrogen adsorbent.

Reprogramming tumor-associated macrophages as a unique approach to target tumor immunotherapy

In the last ten years, it has become increasingly clear that tumor-infiltrating myeloid cells drive not just carcinogenesis via cancer-related inflammatory processes, but also tumor development, invasion, and metastasis. Tumor-associated macrophages (TAMs) in particular are the most common kind of leucocyte in many malignancies and play a crucial role in establishing a favorable microenvironment for tumor cells. Tumor-associated macrophage (TAM) is vital as the primary immune cell subset in the tumor microenvironment (TME).In order to proliferate and spread to new locations, tumors need to be able to hide from the immune system by creating an immune-suppressive environment. Because of the existence of pro-tumoral TAMs, conventional therapies like chemotherapy and radiotherapy often fail to restrain cancer growth. These cells are also to blame for the failure of innovative immunotherapies premised on immune-checkpoint suppression. Understanding the series of metabolic changes and functional plasticity experienced by TAMs in the complex TME will help to use TAMs as a target for tumor immunotherapy and develop more effective tumor treatment strategies. This review summarizes the latest research on the TAMs functional status, metabolic changes and focuses on the targeted therapy in solid tumors.

Stimuli-Activable Metal-Bearing Nanomaterials and Precise On-Demand Antibacterial Strategies

Bacterial infections remain the leading cause of death worldwide today. The emergence of antibiotic resistance has urged the development of alternative antibacterial technologies to complement or replace traditional antibiotic treatments. In this regard, metal nanomaterials have attracted great attention for their controllable antibacterial functions that are less prone to resistance. This review discusses a particular family of stimuli-activable metal-bearing nanomaterials (denoted as SAMNs) and the associated on-demand antibacterial strategies. The various SAMN-enabled antibacterial strategies stem from basic light and magnet activation, with the addition of bacterial microenvironment responsiveness and/or bacteria-targeting selectivity and therefore offer higher spatiotemporal controllability. The discussion focuses on nanomaterial design principles, antibacterial mechanisms, and antibacterial performance, as well as emerging applications that desire on-demand and selective activation (i.e., medical antibacterial treatments, surface anti-biofilm, water disinfection, and wearable antibacterial materials). The review concludes with the authors' perspectives on the challenges and future directions for developing industrial translatable next-generation antibacterial strategies.

Synthetic biology promotes the capture of CO2 to produce fatty acid derivatives in microbial cell factories

Environmental problems such as greenhouse effect, the consumption of fossil energy, and the increase of human demand for energy are becoming more and more serious, which force researcher to turn their attention to the reduction of CO2 and the development of renewable energy. Unsafety, easy to lead to secondary environmental pollution, cost inefficiency, and other problems limit the development of conventional CO2 capture technology. In recent years, many microorganisms have attracted much attention to capture CO2 and synthesize valuable products directly. Fatty acid derivatives (e.g., fatty acid esters, fatty alcohols, and aliphatic hydrocarbons), which can be used as a kind of environmentally friendly and renewable biofuels, are sustainable substitutes for fossil energy. In this review, conventional CO2 capture techniques pathways, microbial CO2 concentration mechanisms and fixation pathways were introduced. Then, the metabolic pathway and progress of direct production of fatty acid derivatives from CO2 in microbial cell factories were discussed. The synthetic biology means used to design engineering microorganisms and optimize their metabolic pathways were depicted, with final discussion on the potential of optoelectronic-microbial integrated capture and production systems.

Can Growth of Nannochloropsis oculata under Modulated Stress Enhance Its Lipid-Associated Biological Properties?

Nannochloropsis oculata is well-recognized as a potential microalgal source of valuable compounds such as polyunsaturated fatty acids, particularly, eicosapentaenoic acid (EPA). The content and profile of these lipids is highly dependent on the growth conditions and can, therefore, be tailored through modulation of the growth parameters, specifically, temperature. Moreover, biological activities are composition dependent. In the present work, lipid extracts obtained from N. oculata, grown under constant temperature and under modulated temperature stress (to increase EPA content; Str) were characterized by GC-FID and several bioactivities were evaluated, namely, antioxidant (L-ORAC_FL), cytotoxic (MTT), adipolytic, anti-hepatic lipid accumulation (steatosis), and anti-inflammatory properties. Both extracts exhibited antioxidant activity (c.a. 49 µmol Trolox_equivalent/mg_extract) and the absence of toxicity (up to 800 µg/mL) toward colon and hepatic cells, adipocytes, and macrophages. They also induced adipolysis and the inhibition of triglycerides hepatic accumulation, with a higher impact from Str. In addition, anti-inflammatory activity was observed in the lipopolysaccharide-induced inflammation of macrophages in the presence of either extract, since lower levels of pro-inflammatory interleukin-6 and interferon-β were obtained, specifically by Str. The results presented herein revealed that modulated temperature stress may enhance the health effects of N. oculata lipid extracts, which may be safely utilized to formulate novel food products.

A two-prong mutagenesis and adaptive evolution strategy to enhance the temperature tolerance and productivity of Nannochloropsis oculata

Incorporation of microalgae in biorefineries intended to help society reach carbon neutrality is hindered by algal growth inhibition at high temperatures, necessitating the use of costly and carbon-intensive cooling systems. In the present study, a two-prong strategy of random mutagenesis and adaptive laboratory evolution to generate robust thermotolerant strains of Nannochloropsis oculata, was used. The best mutants demonstrated increased productivity at 35 °C, which was 10 °C higher than the optimal temperature of the wild type. In a 2-L photobioreactor at 35 °C, biomass and lipid productivity were 1.43-fold and 2.24-fold higher, respectively, than wild type at 25 °C. Higher pigment and carbohydrate content contributed to the mutants' rapid growth and enhanced photosynthetic efficiency. Metabolomics and lipidomics showed rewiring of the central carbon metabolism and membrane lipid synthesis in thermotolerant strains to ensure cellular homeostasis without compromising productivity. Tagatose and phosphatidylethanolamine upregulation were identified as future genetic targets for further enhancing lipid production.

Synthesis characterization of Zn-based MOF and their application in degradation of water contaminants

Metal-organic frameworks (MOFs) are currently popular porous materials with research and application value in various fields such as medicine and engineering. Aiming at the application of MOFs in photocatalysis, this paper mainly reviews the main synthesis methods of ZnMOFs and the latest research progress of Zn MOF-based photocatalysts to degrade organic pollutants in water, such as organic dyes. This nanomaterial is being used to treat wastewater and has proven to be very efficient because of its exceptionally large surface area and porous nature. The results show that Zn-MOFs are capable of high degradation of the above pollutants and over 90% of degradation was observed in publications. In addition, the reusability percentage was examined and studies showed that the Zn-MOF nanostructure has very good stability and can continue to degrade a high percentage of pollutants after several cycles. This review focuses on Zn-MOFs and their composites. First, the methods of synthesis and characterization of these compounds are given. Finally, the application of these composites in the process of photocatalytic degradation of dye pollutants such as methylene blue, methyl orange, crystal violet, rhodamine B, etc. is explained.

Glyceroglycolipids in marine algae: A review of their pharmacological activity

Glyceroglycolipids are major metabolites of marine algae and have a wide range of applications in medicine, cosmetics, and chemistry research fields. They are located on the cell surface membranes. Together with glycoproteins and glycosaminoglycans, known as the glycocalyx, they play critical roles in multiple cellular functions and signal transduction and have several biological properties such as anti-oxidant and anti-inflammatory properties, anti-viral activity, and anti-tumor immunity. This article focused on the sources and pharmacological effects of glyceroglycolipids, which are naturally present in various marine algae, including planktonic algae and benthic algae, with the aim to highlight the promising potential of glyceroglycolipids in clinical treatment.

Mass transfer characteristics and effect of flue gas used in microalgae culture

Flue gas not only contains carbon dioxide (CO₂) but also air pollutants (sulfur oxides (SO_x) and nitrogen oxides (NO_x)). The effective utilization of flue gas could help us to reduce the cost of microalgal biomass production. This study assessed and explored the utilization of flue gas for the absorption characteristics of different components and their biological effect in microalgal culture systems. In abiotic absorption experiments, the absorptivity of CO₂ was reduced by a maximum of 3.1%, and the concentration of the available carbon source in the culture medium was decreased by 6.7% when sulfur dioxide (SO₂, at 100 mg/m³) was presented in the flue gas. Meanwhile, the presence of oxygen (O₂, at 4%) in the flue gas improved the absorptivity of nitric oxide (NO). When Scenedesmus dimorphus was cultured using bisulfites and nitrites (at 10 mmol/L and 8 mmol/L, respectively) as the sulfur and nitrogen sources, SO_x and NO_x in the flue gas did not significantly affect growth of microalgal cells and the carbohydrate, lipid, and protein content. The consumption rates of nutrient elements were calculated, which could provide an adjustment strategy for the initial gas source when culturing microalgae with the flue gas. This study indicates that the flue gas used for microalgal culture should be partially desulfurized, so that the SO_x and CO₂ concentrations can optimize growth of microalgal cells, while the denitrification might not be needed since the flue gas can be oxidized to utilize the NO. KEY POINTS: • The concentration of the available carbon source in the culture medium was decreased when SO₂ was presented in the flue gas, and the presence of O₂ in the flue gas improved the absorptivity of NO. • An adjustment strategy for the initial gas source when culturing microalgae with the flue gas was firstly proposed. • For flue gas containing 10% CO₂ and 60 mg/m³ of SO₂, growth of Scenedesmus dimorphus showed no difference in cell growth in normal culture conditions.

Reducing culture medium nitrogen supply coupled with replenishing carbon nutrient simultaneously enhances the biomass and lipid production of Chlamydomonas reinhardtii

Chlamydomonas reinhardtii is a model strain to explore algal lipid metabolism mechanism, and exhibits great potentials in large-scale production of lipids. Completely lacking nitrogen is an efficient strategy to trigger the lipid synthesis in microalgal cells, while it always leads to the obvious reduction in the biomass. To illustrate the optimal culture substrate carbon (C) and nitrogen (N) levels to simultaneously stimulate the growth and lipid production of C. reinhardtii, cells were cultivated under altered C and N concentrations. Results showed that replenishing 6 g/L sodium acetate (NaAc) could increase 1.50 and 1.53 times biomass and lipid productivity compared with 0 g/L NaAc treatment (the control), but total lipid content slightly decreased. Reducing 75% of basic medium (TAP) N level (0 g/L NaAc + 0.09 g/L NH₄Cl treatment) could promote 21.57% total lipid content in comparison with the control (containing 0.38 g/L NH₄Cl), but decrease 44.45% biomass and 34.15% lipid productivity. The result of the central composite design (CCD) experiment suggested the optimum total lipid content together with higher biomass and lipid productivity could be obtained under the condition of 4.12 g/L NaAc and 0.20 g/L NH₄Cl. They reached 32.14%, 1.68 g/L and 108.21 mg/L/d, and increased by 36.77%, 93.10% and 1.75 times compared with the control, respectively. It suggests moderately increasing C supply and decreasing N levels could synchronously improve the biomass and lipid content of C. reinhardtii.

Phytochemical and toxicological evaluation of Zephyranthes citrina

Drugs obtained from medicinal plants have always played a pivotal role in the field of medicine and to identify novel compounds. Safety profiling of plant extracts is of utmost importance during the discovery of new biologically active compounds and the determination of their efficacy. It is imperative to conduct toxicity studies before exploring the pharmacological properties and perspectives of any plant. The present work aims to provide a detailed insight into the phytochemical and toxicological profiling of methanolic extract of Zephyranthes citrina (MEZ). Guidelines to perform subacute toxicity study (407) and acute toxicity study (425) provided by the organization of economic cooperation and development (OECD) were followed. A single orally administered dose of 2000 mg/kg to albino mice was used for acute oral toxicity testing. In the subacute toxicity study, MEZ in doses of 100, 200, and 400 mg/kg was administered orally, consecutive for 28 days. Results of each parameter were compared to the control group. In both studies, the weight of animals and their selected organs showed consistency with that of the control group. No major toxicity or organ damage was recorded except for some minor alterations in a few parameters such as in the acute study, leukocyte count was increased and decreased platelet count, while in the subacute study platelet count increased in all doses. In the acute toxicity profile liver enzymes Alanine aminotransferase (ALT), as well as, aspartate aminotransferase (AST) were found to be slightly raised while alkaline phosphatase (ALP) was decreased. In subacute toxicity profiling, AST and ALT were not affected by any dose while ALP was decreased only at doses of 200 and 400 mg/kg. Uric acid was raised at a dose of 100 mg/kg. In acute toxicity, at 2000 mg/kg, creatinine and uric acid increased while urea levels decreased. Therefore, it is concluded that the LD₅₀ of MEZ is more than 2000 mg/kg and the toxicity profile of MEZ was generally found to be safe.

Synergistic activities of silver indium sulfide/nickel molybdenum sulfide nanostructures anchored on clay mineral for light-driven bactericidal performance, and detection of uric acid from gout patient serum

In this study, the hydrothermal method was used to synthesis of silver indium sulfide/nickel molybdenum sulfide (AgInS₂/NiMoS₄) nanostructure and decorated on Palygorskite (Plg) as an excellent carrier of antibacterial materials. The performance of the prepared AgInS₂/NiMoS₄/Plg composites was investigated for light-driven antibacterial process and detection of uric acid from biological samples. The result shows the highest antibacterial activity of the AgInS₂/NiMoS₄/Plg with the minimum inhibitory concentrations about 0.2-0.3 mg/mL. The prepared AgInS₂/NiMoS₄/Plg as sensor depicted enhanced peroxidase-like activity for detection of acid uric. The detection limit of acid uric by AgInS₂/NiMoS₄/Plg was about 26.1 nM. Therefore, the AgInS₂/NiMoS₄/Plg can be developed in the bactericidal process and sensing in complex biological systems.

Target of Rapamycin Signaling Involved in the Regulation of Photosynthesis and Cellular Metabolism in Chlorella sorokiniana

Target of rapamycin (TOR) is a serine/threonine protein kinase that plays a central regulating role in cell proliferation, growth, and metabolism, but little is known about the TOR signaling pathway in Chlorella sorokiniana. In this study, a Chlorella sorokiniana DP-1 strain was isolated and identified, and its nutritional compositions were analyzed. Based on homologous sequence analysis, the conserved CsTOR protein was found in the genome of Chlorella sorokiniana. In addition, the key components of TOR complex 1 (TORC1) were present, but the components of TORC2 (RICTOR and SIN1) were absent in Chlorella sorokiniana. Pharmacological assays showed that Chlorella sorokiniana DP-1 was insensitive to rapamycin, Torin1 and KU0063794, whereas AZD8055 could significantly inhibit the growth of Chlorella sorokiniana. RNA-seq analysis showed that CsTOR regulated various metabolic processes and signal transduction pathways in AZD8055-treated Chlorella sorokiniana DP-1. Most genes involved in photosynthesis and carbon fixation in Chlorella sorokiniana DP-1 were significantly downregulated under CsTOR inhibition, indicating that CsTOR positively regulated the photosynthesis in Chlorella sorokiniana. Furthermore, CsTOR controlled protein synthesis and degradation by positively regulating ribosome synthesis and negatively regulating autophagy. These observations suggested that CsTOR plays an important role in photosynthesis and cellular metabolism, and provide new insights into the function of CsTOR in Chlorella sorokiniana.

A biodegradable in situ Zn-Mg2Ge composite for bone-implant applications

Zinc (Zn)-based composites have received extensive attention as promising biodegradable materials due to their unique combination of moderate biodegradability, biocompatibility, and functionality. Nevertheless, the low mechanical strength of as-cast Zn-based composites impedes their practical clinical application. Here we reported the mechanical properties, corrosion behavior, wear properties, and cytotoxicity of in situ synthesized biodegradable Zn-xMg₂Ge (x = 1, 3, and 5 wt.%) composites for bone-implant applications. The mechanical properties of Zn-xMg₂Ge composites were effectively improved by alloying and hot-rolling due to particle reinforcement of the Mg₂Ge intermetallic phase and dynamic recrystallization. The hot-rolled (HR) Zn-3Mg₂Ge composite exhibited the best mechanical properties, including a yield strength of 162.3 MPa, an ultimate tensile strength of 264.3 MPa, an elongation of 10.9%, and a Brinell hardness of 83.9 HB. With an increase in Mg₂Ge content, the corrosion and degradation rates of the HR Zn-xMg₂Ge composites gradually increased, while their wear rate decreased and then increased in Hanks' solution. The diluted extract (12.5% concentration) of the HR Zn-3Mg₂Ge composite showed the highest cell viability compared to the other HR composites and their as-cast pure Zn counterparts. Overall, the HR Zn-3Mg₂Ge composite can be considered a promising biodegradable Zn-based composite for bone-implant applications. STATEMENT OF SIGNIFICANCE: This paper reports the mechanical properties, corrosion behavior, wear properties, and cytotoxicity of in situ synthesized biodegradable Zn-xMg₂Ge (x = 1, 3, and 5 wt.%) composites for bone-implant applications. Our findings demonstrated that the mechanical properties of Zn-xMg₂Ge composites were effectively improved by alloying and hot-rolling due to Mg₂Ge particle reinforcement and dynamic recrystallization. The hot-rolled Zn-3Mg₂Ge composite showed superior cytocompatibility, satisfying corrosion and degradation rates, and the best mechanical properties including a yield strength of 162.3 MPa, an ultimate tensile strength of 264.3 MPa, and an elongation of 10.9%.

Modified chitosan-zeolite supported Pd nanoparticles: A reusable catalyst for the synthesis of 5-substituted-1H-tetrazoles from aryl halides

A novel heterogeneous catalyst has been developed using chitosan-zeolite supported Pd nanoparticles (PdNPs@CS-Zeo) and used in an efficient synthesis of 5-substituted-1H-tetrazoles from aryl halides with high yields for relatively short reaction times with an easy work-up procedure. In this method, highly effective and reusable PdNPs@CS-Zeo catalyst was used in the reaction of various aryl iodides/bromides with K₄[Fe(CN)₆] as a non-toxic cyanide source to catalyze the [2 + 3] cycloaddition of the corresponding aryl nitriles with NaN₃ in the sequential one-pot preparation of 5-substituted-1H-tetrazoles. The synthesized PdNPs@CS-Zeo nanocatalyst was characterized using XRD, FTIR, TEM, HRTEM, XPS, Raman, TG-DTG, ICP-OES, BET, and EDS mapping. Additionally, the nanocatalyst could be effectively separated by filtration and reused for multiple times without significant decrease of catalytic activity.

Visualising the Emerging Platform of Using Microalgae as a Sustainable Bio-Factory for Healthy Lipid Production through Biocompatible AIE Probes

Nowadays, a particular focus is using microalgae to get high-valued health beneficiary lipids. The precise localisation of the lipid droplets (LDs) and biochemical changes are crucial to portray the lipid production strategy in algae, but it requires an in vivo tool to rapidly visualise LD distribution. As a novel strategy, this study focuses on detecting lipid bioaccumulation in a green microalga, Chlamydomonas reinhardtii using the aggregation-induced emission (AIE) based probe, 2-DPAN (C24H18N2O). As the messenger molecule and stress biomarker, hydrogen peroxide (H2O2) activity was detected in lipid synthesis with the AIE probe, TPE-BO (C38H42B2O4). Distinctive LDs labelled with 2-DPAN have elucidated the lipid inducing conditions, where more health beneficiary α-linolenic acid has been produced. TPE-BO labelled H2O2 have clarified the involvement of H2O2 during lipid biogenesis. The co-staining procedure with traditional green BODIPY dye and red chlorophyll indicates that 2-DPAN is suitable for multicolour LD imaging. Compared with BODIPY, 2-DPAN was an efficient sample preparation technique without the washing procedure. Thus, 2-DPAN could improve traditional fluorescent probes currently used for lipid imaging. In addition, the rapid, wash-free, multicolour AIE-based in vivo probe in the study of LDs with 2-DPAN could advance the research of lipid production in microalgae.

Application of Anabaena azotica- and Chlorella pyrenoidosa-Based Algal Biotechnology in Green Production of Algae-Rich Crataegi fructus

Nitrogen-fixing Anabaena and Chlorella pyrenoidosa algal biotechnology are known as new agricultural inputs due to their characteristics and are widely used in the field of agricultural planting. This paper discusses the application of algal biotechnology based on nitrogen-fixing Anabaena sp. The advantages of algal biotechnology based on nitrogen-fixing Anabaena and Chlorella pyrenoidosa in terms of yield, sugar content, polyunsaturated fatty acid content, and high-quality yield of hawthorn were compared.

Diacylglyceryl-N,N,N-trimethylhomoserine-dependent lipid remodeling in a green alga, Chlorella kessleri

Membrane lipid remodeling contributes to the environmental acclimation of plants. In the green lineage, a betaine lipid, diacylglyceryl-N,N,N-trimethylhomoserine (DGTS), is included exclusively among green algae and nonflowering plants. Here, we show that the green alga Chlorella kessleri synthesizes DGTS under phosphorus-deficient conditions through the eukaryotic pathway via the ER. Simultaneously, phosphatidylcholine and phosphatidylethanolamine, which are similar to DGTS in their zwitterionic properties, are almost completely degraded to release 18.1% cellular phosphorus, and to provide diacylglycerol moieties for a part of DGTS synthesis. This lipid remodeling system that substitutes DGTS for extrachloroplast phospholipids to lower the P-quota operates through the expression induction of the BTA1 gene. Investigation of this lipid remodeling system is necessary in a wide range of lower green plants for a comprehensive understanding of their phosphorus deficiency acclimation strategies.

Homo pair formations of thiobarbituric acid: DFT calculations and QTAIM analysis

Homo pair formations of thiobarbituric acid (TBA) were investigated in this work by performing density functional theory (DFT) calculations and the quantum theory of atoms in molecule (QTAIM) analysis. Different types of interactions including N–H . . . O, N–H . . . S, C–H . . . O, and C–H . . . S were involved in formations of five models of homo pair of TBA. In this regard, the results of energy strength and QTAIM features indicated that the model with two N–H . . . O interacting bond (D1) was placed at the highest stability and the model with one N–H . . . O and one C–H . . . S interacting bonds (D5) was placed at the lowest stability. Existence of hydrogen bond (HB) interactions in the models were confirmed based on the obtained results. As a consequence, self-interaction of TBA, as an initiator of pharmaceutical compounds production, was investigated in this work in addition to recognition of existence of different types of interactions.