Excessive fat expenditure in MCT-induced heart failure rats is associated with BMAL1/REV-ERBα circadian rhythmic loop disruption.

Fat loss predicts adverse outcomes in advanced heart failure (HF). Disrupted circadian clocks are a primary cause of lipid metabolic issues, but it's unclear if this disruption affects fat expenditure in HF. To address this issue, we investigated the effects of disruption of the BMAL1/REV-ERBα circadian rhythmic loop on adipose tissue metabolism in HF.50 Wistar rats were initially divided into control (n = 10) and model (n = 40) groups. The model rats were induced with HF via monocrotaline (MCT) injections, while the control group received equivalent solvent injections. After establishing the HF model, the model group was further subdivided into four groups: normal rhythm (LD), inverted rhythm (DL), lentivirus vector carrying Bmal1 short hairpin RNA (LV-Bmal1 shRNA), and empty lentivirus vector control (LV-Control shRNA) groups, each with 10 rats. The DL subgroup was exposed to a reversed light-dark cycle of 8 h: 16 h (dark: light), while the rest adhered to normal light-dark conditions (light: dark 12 h: 12 h). Histological analyses were conducted using H&E, Oil Red O, and Picrosirius red stains to examine adipose and liver tissues. Immunohistochemical staining, RT-qPCR, and Western blotting were performed to detect markers of lipolysis, lipogenesis, and beiging of white adipose tissue (WAT), while thermogenesis indicators were detected in brown adipose tissue (BAT). The LD group rats exhibited decreased levels of BMAL1 protein, increased levels of REV-ERBα protein, and disrupted circadian circuits in adipose tissue compared to controls. Additionally, HF rats showed reduced adipose mass and increased ectopic lipid deposition, along with smaller adipocytes containing lower lipid content and fibrotic adipose tissue. In the LD group WAT, expression of ATGL, HSL, PKA, and p-PKA proteins increased, alongside elevated mRNA levels of lipase genes (Hsl, Atgl, Peripilin) and FFA ß-oxidation genes (Cpt1, acyl-CoA). Conversely, lipogenic gene expression (Scd1, Fas, Mgat, Dgat2) decreased, while beige adipocyte markers (Cd137, Tbx-1, Ucp-1, Zic-1) and UCP-1 protein expression increased. In BAT, HF rats exhibited elevated levels of PKA, p-PKA, and UCP-1 proteins, along with increased expression of thermogenic genes (Ucp-1, Pparγ, Pgc-1α) and lipid transportation genes (Cd36, Fatp-1, Cpt-1). Plasma NT-proBNP levels were higher in LD rats, accompanied by elevated NE and IL-6 levels in adipose tissue. Remarkably, morphologically, the adipocytes in the DL and LV-Bmal1 shRNA groups showed reduced size and lower lipid content, while lipid deposition in the liver was more pronounced in these groups compared to the LD group. At the gene/protein level, the BMAL1/REV-ERBα circadian loop exhibited severe disruption in LV-Bmal1 shRNA rats compared to LD rats. Additionally, there was increased expression of lipase genes, FFA ß oxidation genes, and beige adipocyte markers in WAT, as well as higher expression of thermogenic genes and lipid transportation genes in BAT. Furthermore, plasma NT-proBNP levels and adipose tissue levels of NE and IL-6 were elevated in LV-Bmal1 shRNA rats compared with LD rats. The present study demonstrates that disruption of the BMAL1/REV-ERBα circadian rhythmic loop is associated with fat expenditure in HF. This result suggests that restoring circadian rhythms in adipose tissue may help counteract disorders of adipose metabolism and reduce fat loss in HF.

Evidence on the inhibitory effect of Brassica plants against Acinetobacter baumannii lipases: phytochemical analysis, in vitro, and molecular docking studies.

BACKGROUND: Infections caused by Acinetobacter baumannii are becoming a rising public health problem due to its high degree of acquired and intrinsic resistance mechanisms. Bacterial lipases penetrate and damage host tissues, resulting in multiple infections. Because there are very few effective inhibitors of bacterial lipases, new alternatives for treating A. baumannii infections are urgently needed. In recent years, Brassica vegetables have received a lot of attention since their phytochemical compounds have been directly linked to diverse antimicrobial actions by inhibiting the growth of various Gram-positive and Gram-negative bacteria, yeast, and fungi. Despite their longstanding antibacterial history, there is currently a lack of scientific evidence to support their role in the management of infections caused by the nosocomial bacterium, A. baumannii. This study aimed to address this gap in knowledge by examining the antibacterial and lipase inhibitory effects of six commonly consumed Brassica greens, Chinese cabbage (CC), curly and Tuscan kale (CK and TK), red and green Pak choi (RP and GP), and Brussels sprouts (BR), against A. baumannii in relation to their chemical profiles. METHODS: The secondary metabolites of the six extracts were identified using LC-QTOF-MS/MS analysis, and they were subsequently correlated with the lipase inhibitory activity using multivariate data analysis and molecular docking. RESULTS: In total, 99 metabolites from various chemical classes were identified in the extracts. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) revealed the chemical similarities and variabilities among the specimens, with glucosinolates and phenolic compounds being the major metabolites. RP and GP showed the highest antibacterial activity against A. baumannii, followed by CK. Additionally, four species showed a significant effect on the bacterial growth curves and demonstrated relevant inhibition of A. baumannii lipolytic activity. CK showed the greatest inhibition (26%), followed by RP (21%), GP (21%), and TK (15%). Orthogonal partial least squares-discriminant analysis (OPLS-DA) pinpointed 9 metabolites positively correlated with the observed bioactivities. Further, the biomarkers displayed good binding affinities towards lipase active sites ranging from -70.61 to -30.91 kcal/mol, compared to orlistat. CONCLUSION: This study emphasizes the significance of Brassica vegetables as a novel natural source of potential inhibitors of lipase from A. baumannii.

Exploring the substrate spectrum of phylogenetically distinct bacterial polyesterases.

The rapid escalation of plastic waste accumulation presents a significant threat of the modern world, demanding an immediate solution. Over the last years, utilization of the enzymatic machinery of various microorganisms has emerged as an environmentally friendly asset in tackling this pressing global challenge. Thus, various hydrolases have been demonstrated to effectively degrade polyesters. Plastic waste streams often consist of a variety of different polyesters, as impurities, mainly due to wrong disposal practices, rendering recycling process challenging. The elucidation of the selective degradation of polyesters by hydrolases could offer a proper solution to this problem, enhancing the recyclability performance. Towards this, our study focused on the investigation of four bacterial polyesterases, including DaPUase, IsPETase, PfPHOase, and Se1JFR, a novel PETase-like lipase. The enzymes, which were biochemically characterized and structurally analyzed, demonstrated degradation ability of synthetic plastics. While a consistent pattern of polyesters' degradation was observed across all enzymes, Se1JFR stood out in the degradation of PBS, PLA, and polyether PU. Additionally, it exhibited comparable results to IsPETase, a benchmark mesophilic PETase, in the degradation of PCL and semi-crystalline PET. Our results point out the wide substrate spectrum of bacterial hydrolases and underscore the significant potential of PETase-like enzymes in polyesters degradation.

Phenotypic and genetic characterization of a lipolytic Ralstonia mannitolilytica isolate from petroleum-contaminated soil in Iraq.

BACKGROUND: Lipases play a crucial role in various industrial applications, and microbial lipases, particularly those from bacteria, possess significant properties. With increasing concerns about the environmental and health impacts of hydrocarbons from pipelines and refineries, there is a growing need to mitigate the risks associated with these compounds. METHODS: In this study, 40 bacterial isolates were recovered from contaminated soil samples collected from multiple refineries across Iraq. Using the Vitek system, bacterial isolates were identified up to the species level, revealing that only 12 isolates exhibited lipase-producing capabilities. RESULTS: Among the lipase-producing isolates, Ralstonia mannitolilytica demonstrated the highest extracellular lipase activity, as determined by an olive oil plate assay supplemented with rhodamine B. Confirmation of the species identity was achieved through 16S rRNA gene sequencing, with the obtained sequence deposited under accession number LC772176.1. Further sequence analysis revealed single nucleotide polymorphisms (SNPs) in the genome of Ralstonia mannitolilytica strain H230303-10_N19_7x_R2 (CP011257.1, positions 1,311,102 and 1,311,457). Additionally, the presence of the lipase gene was confirmed through amplification and sequencing using a thermocycler PCR. Sequence analysis of the gene, aligned using Geneious Prime software, identified SNPs (CP010799, CP049132, AY364601, CP011257, and CP023537), and a phylogenetic tree was constructed based on genetic characterization. CONCLUSION: Our findings highlight the potential of Ralstonia mannitolilytica as a promising candidate for lipase production and contribute to our understanding of its genetic diversity and biotechnological applications in hydrocarbon degradation and industrial processes.

Lipase-Catalyzed Preparation and Optimization of Structured Phosphatidylcholine Containing Nervonic Acid.

This study investigated the incorporation of nervonic acid into the chemical structure of phosphatidylcholine via a lipase-catalyzed acidolysis reaction to obtain a functional phospholipid. Lipase immobilization was conducted, and Amberlite XAD7-HP was selected as a carrier to immobilize phospholipase A1 (PLA1) for subsequent experiments. The main acidolysis reaction parameters, including enzyme load, substrate ratio, temperature, and water content, were studied against the reaction time. The optimum reaction conditions obtained were enzyme load, 20%; reaction temperature, 55 °C; water content, 1%; and reaction time, 9 h. The maximum incorporation of nervonic acid into phosphatidylcholine was 48 mol%, with PC recovery at 61.6 mol%. The positional distribution of structured phosphatidylcholine shows that nervonic acid was found in the sn-1 position due to enzyme specificity and in the sn-2 position, possibly due to acyl migration.

Latest Trends in Lipase-Catalyzed Synthesis of Ester Carbohydrate Surfactants: From Key Parameters to Opportunities and Future Development.

Carbohydrate-based surfactants are amphiphilic compounds containing hydrophilic moieties linked to hydrophobic aglycones. More specifically, carbohydrate esters are biosourced and biocompatible surfactants derived from inexpensive renewable raw materials (sugars and fatty acids). Their unique properties allow them to be used in various areas, such as the cosmetic, food, and medicine industries. These multi-applications have created a worldwide market for biobased surfactants and consequently expectations for their production. Biobased surfactants can be obtained from various processes, such as chemical synthesis or microorganism culture and surfactant purification. In accordance with the need for more sustainable and greener processes, the synthesis of these molecules by enzymatic pathways is an opportunity. This work presents a state-of-the-art lipase action mode, with a focus on the active sites of these proteins, and then on four essential parameters for optimizing the reaction: type of lipase, reaction medium, temperature, and ratio of substrates. Finally, this review discusses the latest trends and recent developments, showing the unlimited potential for optimization of such enzymatic syntheses.

Immobilized lipase enzyme on green synthesized magnetic nanoparticles using Psidium guava leaves for dye degradation and antimicrobial activities.

Zinc ferrite nanoparticles (ZnF NPs) were synthesized by a green method using Psidium guava Leaves extract and characterized via structural and optical properties. The surface of ZnF NPs was stabilized with citric acid (CA) by a direct addition method to obtain (ZnF-CA NPs), and then lipase (LP) enzyme was immobilized on ZnF-CA NPs to obtain a modified ZnF-CA-LP nanocomposite (NCs). The prepared sample's photocatalytic activity against Methylene blue dye (MB) was determined. The antioxidant activity of ZnF-CA-LP NCs was measured using 1,1-diphenyl-2-picryl hydrazyl (DPPH) as a source of free radicals. In addition, the antibacterial and antibiofilm capabilities of these substances were investigated by testing them against gram-positive Staphylococcus aureus (S. aureus ATCC 25923) and gram-negative Escherichia coli (E. coli ATCC 25922) bacterial strains. The synthesized ZnF NPs were discovered to be situated at the core of the material, as determined by XRD, HRTEM, and SEM investigations, while the CA and lipase enzymes were coated in this core. The ZnF-CA-LP NCs crystallite size was around 35.0 nm at the (311) plane. Results obtained suggested that 0.01 g of ZnF-CA-LP NCs achieved 96.0% removal of 5.0 ppm of MB at pH 9.0. In-vitro zone of inhibition (ZOI) and minimum inhibitory concentration (MIC) results verified that ZnF-CA-LP NCs exhibited its encouraged antimicrobial activity against S. aureus and E. coli (20.0 ± 0.512, and 27.0 ± 0.651 mm ZOI, respectively) & (1.25, and 0.625 µg/ml MIC, respectively). ZnF-CA-LP NPs showed antibiofilm percentage against S. aureus (88.4%) and E. coli (96.6%). Hence, ZnF-CA-LP NCs are promising for potential applications in environmental and biomedical uses.

Hydrophobic Clusters Regulate Surface Hydration Dynamics of Bacillus subtilis Lipase A.

The surface hydration diffusivity of Bacillus subtilis Lipase A (BSLA) has been characterized by low-field Overhauser dynamic nuclear polarization (ODNP) relaxometry using a series of spin-labeled constructs. Sites for spin-label incorporation were previously designed via an atomistic computational approach that screened for surface exposure, reflective of the surface hydration comparable to other proteins studied by this method, as well as minimal impact on protein function, dynamics, and structure of BSLA by excluding any surface site that participated in greater than 30% occupancy of a hydrogen bonding network within BSLA. Experimental ODNP relaxometry coupling factor results verify the overall surface hydration behavior for these BSLA spin-labeled sites similar to other globular proteins. Here, by plotting the ODNP parameters of relative diffusive water versus the relative bound water, we introduce an effective "phase-space" analysis, which provides a facile visual comparison of the ODNP parameters of various biomolecular systems studied to date. We find notable differences when comparing BSLA to other systems, as well as when comparing different clusters on the surface of BSLA. Specifically, we find a grouping of sites that correspond to the spin-label surface location within the two main hydrophobic core clusters of the branched aliphatic amino acids isoleucine, leucine, and valine cores observed in the BSLA crystal structure. The results imply that hydrophobic clustering may dictate local surface hydration properties, perhaps through modulation of protein conformations and samplings of the unfolded states, providing insights into how the dynamics of the hydration shell is coupled to protein motion and fluctuations.

Glucose controls lipolysis through Golgi PtdIns4P-mediated regulation of ATGL.

Metabolic crosstalk of the major nutrients glucose, amino acids and fatty acids (FAs) ensures systemic metabolic homeostasis. The coordination between the supply of glucose and FAs to meet various physiological demands is especially important as improper nutrient levels lead to metabolic disorders, such as diabetes and metabolic dysfunction-associated steatohepatitis (MASH). In response to the oscillations in blood glucose levels, lipolysis is thought to be mainly regulated hormonally to control FA liberation from lipid droplets by insulin, catecholamine and glucagon. However, whether general cell-intrinsic mechanisms exist to directly modulate lipolysis via glucose sensing remains largely unknown. Here we report the identification of such an intrinsic mechanism, which involves Golgi PtdIns4P-mediated regulation of adipose triglyceride lipase (ATGL)-driven lipolysis via intracellular glucose sensing. Mechanistically, depletion of intracellular glucose results in lower Golgi PtdIns4P levels, and thus reduced assembly of the E3 ligase complex CUL7FBXW8 in the Golgi apparatus. Decreased levels of the E3 ligase complex lead to reduced polyubiquitylation of ATGL in the Golgi and enhancement of ATGL-driven lipolysis. This cell-intrinsic mechanism regulates both the pool of intracellular FAs and their extracellular release to meet physiological demands during fasting and glucose deprivation. Moreover, genetic and pharmacological manipulation of the Golgi PtdIns4P-CUL7FBXW8-ATGL axis in mouse models of simple hepatic steatosis and MASH, as well as during ex vivo perfusion of a human steatotic liver graft leads to the amelioration of steatosis, suggesting that this pathway might be a promising target for metabolic dysfunction-associated steatotic liver disease and possibly MASH.

Metagenomic investigations into the microbial consortia, degradation pathways, and enzyme systems involved in the biodegradation of plastics in a tropical lentic pond sediment.

The exploitation of exciting features of plastics for diverse applications has resulted in significant plastic waste generation, which negatively impacts environmental compartments, metabolic processes, and the well-being of aquatic ecosystems biota. A shotgun metagenomic approach was deployed to investigate the microbial consortia, degradation pathways, and enzyme systems involved in the degradation of plastics in a tropical lentic pond sediment (APS). Functional annotation of the APS proteome (ORFs) using the PlasticDB database revealed annotation of 1015 proteins of enzymes such as depolymerase, esterase, lipase, hydrolase, nitrobenzylesterase, chitinase, carboxylesterase, polyesterase, oxidoreductase, polyamidase, PETase, MHETase, laccase, alkane monooxygenase, among others involved in the depolymerization of the plastic polymers. It also revealed that polyethylene glycol (PEG), polyhydroxyalkanoates (PHA), polyhydroxybutyrate (PHB), polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), polyethylene terephthalate (PET), and nylon have the highest number of annotated enzymes. Further annotation using the KEGG GhostKOALA revealed that except for terephthalate, all the other degradation products of the plastic polymers depolymerization such as glyoxylate, adipate, succinate, 1,4-butanediol, ethylene glycol, lactate, and acetaldehyde were further metabolized to intermediates of the tricarboxylic acid cycle. Taxonomic characterization of the annotated proteins using the AAI Profiler and BLASTP revealed that Pseudomonadota members dominate most plastic types, followed by Actinomycetota and Acidobacteriota. The study reveals novel plastic degraders from diverse phyla hitherto not reported to be involved in plastic degradation. This suggests that plastic pollution in aquatic environments is prevalent with well-adapted degrading communities and could be the silver lining in mitigating the impacts of plastic pollution in aquatic environments.

The fatty liver disease-causing protein PNPLA3-I148M alters lipid droplet-Golgi dynamics.

Nonalcoholic fatty liver disease, recently renamed metabolic dysfunction-associated steatotic liver disease (MASLD), is a progressive metabolic disorder that begins with aberrant triglyceride accumulation in the liver and can lead to cirrhosis and cancer. A common variant in the gene PNPLA3, encoding the protein PNPLA3-I148M, is the strongest known genetic risk factor for MASLD. Despite its discovery 20 y ago, the function of PNPLA3, and now the role of PNPLA3-I148M, remain unclear. In this study, we sought to dissect the biogenesis of PNPLA3 and PNPLA3-I148M and characterize changes induced by endogenous expression of the disease-causing variant. Contrary to bioinformatic predictions and prior studies with overexpressed proteins, we demonstrate here that PNPLA3 and PNPLA3-I148M are not endoplasmic reticulum-resident transmembrane proteins. To identify their intracellular associations, we generated a paired set of isogenic human hepatoma cells expressing PNPLA3 and PNPLA3-I148M at endogenous levels. Both proteins were enriched in lipid droplet, Golgi, and endosomal fractions. Purified PNPLA3 and PNPLA3-I148M proteins associated with phosphoinositides commonly found in these compartments. Despite a similar fractionation pattern as the wild-type variant, PNPLA3-I148M induced morphological changes in the Golgi apparatus, including increased lipid droplet-Golgi contact sites, which were also observed in I148M-expressing primary human patient hepatocytes. In addition to lipid droplet accumulation, PNPLA3-I148M expression caused significant proteomic and transcriptomic changes that resembled all stages of liver disease. Cumulatively, we validate an endogenous human cellular system for investigating PNPLA3-I148M biology and identify the Golgi apparatus as a central hub of PNPLA3-I148M-driven cellular change.

Antisolvent precipitation for the synergistic preparation of ultrafine particles of nobiletin under ultrasonication-homogenization and evaluation of the inhibitory effects of α-glucosidase and porcine pancreatic lipase in vitro.

To further enhance the application of nobiletin (an important active ingredient in Citrus fruits), we used ultrasonic homogenization-assisted antisolvent precipitation to create ultrafine particles of nobiletin (UPN). DMSO was used as the solvent, and deionized water was used as the antisolvent. When ultrasonication (670 W) and homogenization (16000 r/min) were synergistic, the solution concentration was 57 mg/mL, and the minimum particle size of UPN was 521.02 nm. The UPN samples outperformed the RN samples in terms of the inhibition of porcine pancreatic lipase, which was inhibited (by 500 mg/mL) by 68.41 % in the raw sample, 90.34 % in the ultrafine sample, and 83.59 % in the positive control, according to the data. Fourier transform infrared spectroscopy analysis revealed no chemical changes in the samples before or after preparation. However, the crystallinity of the processed ultrafine nobiletin particles decreased. Thus, this work offers significant relevance for applications in the realm of food chemistry and indirectly illustrates the expanded application potential of nobiletin.

Intracellular lipase and regulation of the lipid droplet.

PURPOSE OF REVIEW: Lipid droplets are increasingly recognized as distinct intracellular organelles that have functions exclusive to the storage of energetic lipids. Lipid droplets modulate macrophage inflammatory phenotype, control the availability of energy for muscle function, store excess lipid, sequester toxic lipids, modulate mitochondrial activity, and allow transfer of fatty acids between tissues. RECENT FINDINGS: There have been several major advances in our understanding of the formation, dissolution, and function of this organelle during the past two years. These include new information on movement and partition of amphipathic proteins between the cytosol and lipid droplet surface, molecular determinants of lipid droplet formation, and pathways leading to lipid droplet hydrophobic lipid formation. Rapid advances in mitochondrial biology have also begun to define differences in their function and partnering with lipid droplets to modulate lipid storage versus oxidation. SUMMARY: This relationship of lipid droplets biology and cellular function provides new understanding of an important cellular organelle that influences muscle function, adipose lipid storage, and diseases of lipotoxicity.

Synthesis of Enantiopure (S)-Atenolol by Utilization of Lipase-Catalyzed Kinetic Resolution of a Key Intermediate.

(S)-Atenolol ((S)-2-(4-(2-Hydroxy-3-(isopropylamino)propoxy)phenyl)acetamide) has been synthesized in >99% enantiomeric excess (ee) with the use of Candida antarctica lipase B from Syncozymes (Shanghai, China), in a kinetic resolution of the corresponding racemic chlorohydrin. A catalytic amount of base was used in deprotonation of the phenol building block. The enantiopurity of the chlorohydrin building block remained unchanged upon subsequent amination to yield the final drug. All four steps in the synthesis protocol have been optimized compared to previously reported methods, which makes this new protocol more sustainable and in accordance with green chemistry principles. The overall yield of (S)-atenolol was 9.9%, which will be further optimized.

In Silico Description of the Direct Inhibition Mechanism of Endothelial Lipase by ANGPTL3.

Angiopoietin-like protein 3 (ANGPTL3) is a plasmatic protein that plays a crucial role in lipoprotein metabolism by inhibiting the lipoprotein lipase (LPL) and the endothelial lipase (EL) responsible for the hydrolysis of phospholipids on high-density lipoprotein (HDL). Interest in developing new pharmacological therapies aimed at inhibiting ANGPTL3 has been growing due to the hypolipidemic and antiatherogenic profile observed in its absence. The goal of this study was the in silico characterization of the interaction between ANGPTL3 and EL. Because of the lack of any structural information on both the trimeric coiled-coil N-terminal domain of ANGPTL3 and the EL homodimer as well as data regarding their interactions, the first step was to obtain the three-dimensional model of these two proteins. The models were then refined via molecular dynamics (MD) simulations and used to investigate the interaction mechanism. The analysis of interactions in different docking poses and their refinement via MD allowed the identification of three specific glutamates of ANGPTL3 that recognize a positively charged patch on the surface of EL. These ANGPTL3 key residues, i.e., Glu154, Glu157, and Glu160, could form a putative molecular recognition site for EL. This study paves the way for future investigations aimed at confirming the recognition site and at designing novel inhibitors of ANGPTL3.

Kombucha Tea-associated microbes remodel host metabolic pathways to suppress lipid accumulation.

The popularity of the ancient, probiotic-rich beverage Kombucha Tea (KT) has surged in part due to its purported health benefits, which include protection against metabolic diseases; however, these claims have not been rigorously tested and the mechanisms underlying host response to the probiotics in KT are unknown. Here, we establish a reproducible method to maintain C. elegans on a diet exclusively consisting of Kombucha Tea-associated microbes (KTM), which mirrors the microbial community found in the fermenting culture. KT microbes robustly colonize the gut of KTM-fed animals and confer normal development and fecundity. Intriguingly, animals consuming KTMs display a marked reduction in total lipid stores and lipid droplet size. We find that the reduced fat accumulation phenotype is not due to impaired nutrient absorption, but rather it is sustained by a programed metabolic response in the intestine of the host. KTM consumption triggers widespread transcriptional changes within core lipid metabolism pathways, including upregulation of a suite of lysosomal lipase genes that are induced during lipophagy. The elevated lysosomal lipase activity, coupled with a decrease in lipid droplet biogenesis, is partially required for the reduction in host lipid content. We propose that KTM consumption stimulates a fasting-like response in the C. elegans intestine by rewiring transcriptional programs to promote lipid utilization. Our results provide mechanistic insight into how the probiotics in Kombucha Tea reshape host metabolism and how this popular beverage may impact human metabolism.

LET-767 determines lipid droplet protein targeting and lipid homeostasis.

Lipid droplets (LDs) are composed of a core of neutral lipids wrapped by a phospholipid (PL) monolayer containing several hundred proteins that vary between different cells or organisms. How LD proteins target to LDs is still largely unknown. Here, we show that RNAi knockdown or gene mutation of let-767, encoding a member of hydroxysteroid dehydrogenase (HSD), displaced the LD localization of three well-known LD proteins: DHS-3 (dehydrogenase/reductase), PLIN-1 (perilipin), and DGAT-2 (diacylglycerol O-acyltransferase 2), and also prevented LD growth in Caenorhabditis elegans. LET-767 interacts with ARF-1 (ADP-ribosylation factor 1) to prevent ARF-1 LD translocation for appropriate LD protein targeting and lipid homeostasis. Deficiency of LET-767 leads to the release of ARF-1, which further recruits and promotes translocation of ATGL-1 (adipose triglyceride lipase) to LDs for lipolysis. The displacement of LD proteins caused by LET-767 deficiency could be reversed by inhibition of either ARF-1 or ATGL-1. Our work uncovers a unique LET-767 for determining LD protein targeting and maintaining lipid homeostasis.

Enhancing biocatalyst performance through immobilization of lipase (Eversa® Transform 2.0) on hybrid amine-epoxy core-shell magnetic nanoparticles.

Magnetic nanoparticles were functionalized with polyethylenimine (PEI) and activated with epoxy. This support was used to immobilize Lipase (Eversa® Transform 2.0) (EVS), optimization using the Taguchi method. XRF, SEM, TEM, XRD, FTIR, TGA, and VSM performed the characterizations. The optimal conditions were immobilization yield (I.Y.) of 95.04 ± 0.79 %, time of 15 h, ionic load of 95 mM, protein load of 5 mg/g, and temperature of 25 °C. The maximum loading capacity was 25 mg/g, and its stability in 60 days of storage showed a negligible loss of only 9.53 % of its activity. The biocatalyst demonstrated better stability at varying temperatures than free EVS, maintaining 28 % of its activity at 70 °C. It was feasible to esterify free fatty acids (FFA) from babassu oil with the best reaction of 97.91 % and ten cycles having an efficiency above 50 %. The esterification of produced biolubricant was confirmed by NMR, and it displayed kinematic viscosity and density of 6.052 mm2/s and 0.832 g/cm3, respectively, at 40 °C. The in-silico study showed a binding affinity of -5.8 kcal/mol between EVS and oleic acid, suggesting a stable substrate-lipase combination suitable for esterification.

Pretreatment of shrimp shells with an acidic deep eutectic solvent system for chitin extraction and its enhanced performance as a carrier for immobilized lipase.

Existing methods for chitin extraction usually produce substantial waste, which poses ecological hazards. Natural deep eutectic solvent (NADES) offers a promising one-step pretreatment alternative, replacing the resource-intensive demineralization (DM) and deproteinization (DP) process. Hence, in this study, the influence of various acidic NADES, on achieving a simplified one-step DM and DP in the chitin extraction process was investigated. The study yielded chitin with 87.73 % purity, and microstructural analysis showed that NADES pretreatment minimally affected chitin quality without deacetylation. In addition, chitin extracted using choline chloride-oxalic acid as a carrier displayed excellent performance in the immobilization of Geobacillus thermocatenulatus lipase 2 (GTL2) because of obvious Ca2+ activation effect. This process contributed to enhancement of immobilized enzyme activity. The immobilized GTL2 showed excellent hydrolytic capabilities, with its highest activity reaching 547.80 ± 20.62 U/mg, significantly better than the five commercial lipases that exhibited <40 % of the enzyme activity. Furthermore, the hydrolytic capacity of immobilized GTL2 was notably high for 4-nitrophenyl butyrate, measuring 935.47 ± 51.60 U/mg. This study provided a constructive approach for the one-step pretreatment of shrimp shells with organic acid-based NADES to isolate and purify chitin and its potential application as an immobilized carrier to enhance enzyme activity.