Effects of neuropeptide F signaling on feeding, growth and development of Plutella xylostella (L.) larvae

The neuropeptide F (NPF) signaling, comprising NPF and neuropeptide F receptor (NPFR), role in regulating insect behaviors and physiological processes. We cloned the genes encoding NPF and NPFR from Plutella xylostella, a notorious pest of cruciferous crops. Notably, the NPF gene produced two splicing variants, Px-NPF1 and Px-NPF2, with distinct expression patterns. Conserved C-terminal RPRFamide motif and seven transmembrane α-helics were observed in Px-NPF and in Px-NPFR, respectively. Px-NPF and Px-NPFR are widely expressed across all larval instars and are predominantly localized in the brain and midgut. The transcriptional levels of Px-NPF1 and Px-NPFR increased and reached maximum at 8 h after food deprived. RNA interference targeting Px-NPF and Px-NPFR resulted in smaller body size, delayed larval growth and alterations in energy metabolism. Specific binding assays revealed stronger binding affinity of Px-NPF1 with Px-NPFR than Px-NPF2. Three-dimensional models of the Px-NPF-NPFR complexes via AlphaFold 3 highlighted the critical roles of two highly conserved residues across insects, Tyr46 and His196, in interaction. Our findings underscore the potential of targeting NPF-NPFR signaling for P. xylostella controlling and contributing to developing novel pest management strategies.

Improvement of yoghurt gel syneresis by trehalose: Effect on rheological properties, water distribution, and microstructure

Three low molecular weight (LMW) sweeteners (D-tagatose, erythritol, and trehalose) were studied in yoghurt formulations to investigate their effects on syneresis, rheological properties, water distribution, and microstructural characteristics. The results indicated that trehalose improved syneresis, the fermentation process, and rheological properties compared to yoghurt fortified with sucrose, while D-tagatose and erythritol demonstrated the opposite effects on fermentation. With the addition of LMW sweeteners, the apparent viscosity and frequency sweep of yoghurt increased, with trehalose showing a better effect than sucrose or the other two LMW sweeteners. The water distribution, as indicated by T2 relaxation time, was also significantly improved with trehalose. Electron microscopy results showed that the three LMW sweeteners decreased the porous structure of the yoghurt gel and enhanced protein aggregation, leading to a denser network. Fourier-transform infrared spectroscopy results demonstrated that trehalose increased the disorder of hydrocarbon chains, the vibrations of N-H and C-N groups, and the C-O stretching, promoting the formation of casein/trehalose complexes, which improved the gel syneresis of yoghurt containing trehalose. Those results suggest that trehalose could be used as a novel sweetener to replace sucrose in dairy products. PRACTICAL APPLICATION: This study investigated the rheological, gel syneresis, water distribution, and microstructural properties of yoghurt with three LMW sweeteners and found that yoghurt supplemented with trehalose significantly improved syneresis and the structure of casein micelles through increased hydroxyl groups. Trehalose can potentially be used trehalose as a yoghurt stabilizer for dairy production, enhancing gel syneresis properties.

Effect of delignification on the adsorption of loofah sponge-based immobilized metal affinity chromatography adsorbent for His-tagged trehalose synthase

The effect of delignification on the adsorption capacity of loofah sponge-based immobilized metal affinity chromatography adsorbents was investigated with recombinant His-tagged trehalose synthase as the model protein. Pretreatments with [EMIM][Ac] ionic liquid at 80 °C for 5 h and with sodium chlorite/acetic acid at 80 °C for 2 h were found effective for the removal of lignin, leading to a loss in biomass of 15.7% and 25.2%, respectively. Upon delignification, the metal chelating capacities of the loofah sponge-based adsorbents prepared with 5-h ionic liquid pretreatment (712 ± 82 μmole Cu(II)/g) and with 2-h sodium chlorite/acetic acid pretreatment (1012 ± 18 μmole Cu(II)/g) were 38% and 97% higher than that of the control (514 ± 55 μmole Cu(II)/g), adsorbent prepared with untreated loofah sponge, respectively. Results of protein adsorption study indicated that the Co(II)-loaded adsorbent prepared with 2-h sodium chlorite/acetic acid pretreatment exhibited the highest adsorption capacity and selectivity for the recombinant His-tagged trehalose synthase, giving a purification product with a specific activity of 7.62 U/mg protein. The predicted maximum adsorption capacity of the delignified loofah sponge-based adsorbent, 2.04 ± 0.14 mg/g, was 73% higher than that of the control.

Pulmonary Inhalation of Biotherapeutics: A Systematic Approach to Understanding the Effects of Atomisation Gas Flow Rate on Particle Physiochemical Properties and Retained Bioactivity

The identification of spray-drying processing parameters capable of producing particles suitable for pulmonary inhalation with retained bioactivity underpins the development of inhalable biotherapeutics. Effective delivery of biopharmaceuticals via pulmonary delivery routes such as dry powder inhalation (DPI) requires developing techniques that engineer particles to well-defined target profiles while simultaneously minimising protein denaturation. This study examines the simultaneous effects of atomisation gas flow rate on particle properties and retained bioactivity for the model biopharmaceutical lysozyme. The results show that optimising the interplay between atomisation gas flow rate and excipient concentration enables the production of free-flowing powder with retained bioactivity approaching 100%, moisture content below 4%, and D50 < 4 µm, at yields exceeding 50%. The developed methodologies inform the future design of protein-specific spray-drying parameters for inhalable biotherapeutics.

Advancements in enzyme immobilization on magnetic nanomaterials: toward sustainable industrial applications

Enzymes are widely used in biofuels, food, and pharmaceuticals. The immobilization of enzymes on solid supports, particularly magnetic nanomaterials, enhances their stability and catalytic activity. Magnetic nanomaterials are chosen for their versatility, large surface area, and superparamagnetic properties, which allow for easy separation and reuse in industrial processes. Researchers focus on the synthesis of appropriate nanomaterials tailored for specific purposes. Immobilization protocols are predefined and adapted to both enzymes and support requirements for optimal efficiency. This review provides a detailed exploration of the application of magnetic nanomaterials in enzyme immobilization protocols. It covers methods, challenges, advantages, and future perspectives, starting with general aspects of magnetic nanomaterials, their synthesis, and applications as matrices for solid enzyme stabilization. The discussion then delves into existing enzymatic immobilization methods on magnetic nanomaterials, highlighting advantages, challenges, and potential applications. Further sections explore the industrial use of various enzymes immobilized on these materials, the development of enzyme-based bioreactors, and prospects for these biocatalysts. In summary, this review provides a concise comparison of the use of magnetic nanomaterials for enzyme stabilization, highlighting potential industrial applications and contributing to manufacturing optimization.

Physiological characterization of polyextremotolerant yeasts from cold environments of Patagonia

Yeasts from cold environments have a wide range of strategies to prevent the negative effects of extreme conditions, including the production of metabolites of biotechnological interest. We investigated the growth profile and production of metabolites in yeast species isolated from cold environments. Thirty-eight strains were tested for their ability to grow at different temperatures (5-30 °C) and solute concentrations (3-12.5% NaCl and 50% glucose). All strains tested were able to grow at 5 °C, and 77% were able to grow with 5% NaCl at 18 °C. We were able to group strains based on different physicochemical/lifestyle profiles such as polyextremotolerant, osmotolerant, psychrotolerant, or psychrophilic. Five strains were selected to study biomass and metabolite production (glycerol, trehalose, ergosterol, and mycosporines). These analyses revealed that the accumulation pattern of trehalose and ergosterol was related to each lifestyle profile. Also, our findings would suggest that mycosporines does not have a role as an osmolyte. Non-conventional fermentative yeasts such as Phaffia tasmanica and Saccharomyces eubayanus may be of interest for trehalose production. This work contributes to the knowledge of non-conventional yeasts with biotechnological application from cold environments, including their growth profile, metabolites, and biomass production under different conditions.

Contribution of trehalose to ethanol stress tolerance of Wickerhamomyces anomalus

BACKGROUND

The ascomycetous heterothallic yeast Wickerhamomyces anomalus (WA) has received considerable attention and has been widely reported in the winemaking industry for its distinctive physiological traits and metabolic attributes. An increased concentration of ethanol during ethanol fermentation, however, causes ethanol stress (ES) on the yeast cells. Trehalose has been implicated in improving survival under various stress conditions in microorganisms. Herein, we determined the effects of trehalose supplementation on the survival, differentially expressed genes (DEGs), cellular morphology, and oxidative stress tolerance of WA in response to ES.

RESULTS

The results indicated that trehalose improved the survival and anomalous surface and ultrastructural morphology of WA. Additionally, trehalose improved redox homeostasis by reducing the levels of reactive oxygen species (ROS) and inducing the activities of antioxidant enzymes. In addition, DEGs affected by the application of trehalose were enriched in these categories including in gene expression, protein synthesis, energy metabolism, and cell cycle pathways. Additionally, trehalose increased the content of intracellular malondialdehyde (MDA) and adenosine triphosphate.

CONCLUSIONS

These results reveal the protective role of trehalose in ES mitigation and strengthen the possible uses of WA in the wine fermentation sector.

Atmospheric humidity regulates same-sex mating in Candida albicans through the trehalose and osmotic signaling pathways

Sexual reproduction is prevalent in eukaryotic organisms and plays a critical role in the evolution of new traits and in the generation of genetic diversity. Environmental factors often have a direct impact on the occurrence and frequency of sexual reproduction in fungi. The regulatory effects of atmospheric relative humidity (RH) on sexual reproduction and pathogenesis in plant fungal pathogens and in soil fungi have been extensively investigated. However, the knowledge of how RH regulates the lifecycles of human fungal pathogens is limited. In this study, we report that low atmospheric RH promotes the development of mating projections and same-sex (homothallic) mating in the human fungal pathogen Candida albicans. Low RH causes water loss in C. albicans cells, which results in osmotic stress and the generation of intracellular reactive oxygen species (ROS) and trehalose. The water transporting aquaporin Aqy1, and the G-protein coupled receptor Gpr1 function as cell surface sensors of changes in atmospheric humidity. Perturbation of the trehalose metabolic pathway by inactivating trehalose synthase or trehalase promotes same-sex mating in C. albicans by increasing osmotic or ROS stresses, respectively. Intracellular trehalose and ROS signal the Hog1-osmotic and Hsf1-Hsp90 signaling pathways to regulate the mating response. We, therefore, propose that the cell surface sensors Aqy1 and Gpr1, intracellular trehalose and ROS, and the Hog1-osmotic and Hsf1-Hsp90 signaling pathways function coordinately to regulate sexual mating in response to low atmospheric RH conditions in C. albicans.

Protective role of trehalose in the Namib desert ant, Ocymyrmex robustior

Over recent decades, increasing attention has been paid to how low-molecular-weight molecules affect thermal tolerance in animals. Although the disaccharide sugar trehalose is known to serve as a thermal protectant in unicellular organisms, nothing is known about its potential role in insects. In this study, we investigated the effect of trehalose on heat tolerance in the Namib desert ant, Ocymyrmex robustior, one of the most thermotolerant animals found in terrestrial ecosystems. First, we tested whether a trehalose-supplemented diet increased worker survival following exposure to heat stress. Second, we assessed the degree of protein damage by comparing protein aggregation levels for trehalose-supplemented workers and control workers. Third, we compared the expression levels of three genes involved in trehalose metabolism. We found that trehalose supplementation significantly enhanced worker heat tolerance, increased metabolic levels of trehalose and reduced protein aggregation under conditions of heat stress. Expression levels of the three genes varied in a manner that was consistent with the maintenance of trehalose in the hemolymph and tissues under conditions of heat stress. Altogether, these results suggest that increased trehalose concentration may help protect Namib desert ant individuals against heat stress. More generally, they highlight the role played by sugar metabolites in boosting tolerance in extremophiles.

Trehalose and its applications in the food industry

Trehalose is a nonreducing disaccharide composed of two glucose molecules linked by α, α-1,1-glycosidic bond. It is present in a wide variety of organisms, including bacteria, fungi, insects, plants, and invertebrate animals. Trehalose has distinct physical and chemical properties that have been investigated for their biological importance in a range of prokaryotic and eukaryotic species. Emerging research on trehalose has identified untapped opportunities for its application in the food, medical, pharmaceutical, and cosmetics industries. This review summarizes the chemical and biological properties of trehalose, its occurrence and metabolism in living organisms, its protective role in molecule stabilization, and natural and commercial production methods. Utilization of trehalose in the food industry, in particular how it stabilizes protein, fat, carbohydrate, and volatile compounds, is also discussed in depth. Challenges and opportunities of its application in specific applications (e.g., diagnostics, bioprocessing, ingredient technology) are described. We conclude with a discussion on the potential of leveraging the unique molecular properties of trehalose in molecular stabilization for improving the safety, quality, and sustainability of our food systems.

Stabilization Effects Induced by Trehalose on Creatine Aqueous Solutions Investigated by Infrared Spectroscopy

Creatine is a very popular amino acid widely utilized in the sports world due to its functions mainly related to muscle building and increasing performance. The present work investigates the behavior of creatine aqueous solutions and of creatine aqueous in the presence of trehalose as a function of time changes by means of Infrared spectroscopy. Infrared spectra have been gathered and studied over time for both the full spectrum and the intramolecular OH-stretching region for the two mixtures. This latter region was studied more specifically using a cutting-edge technique called Spectral Distance (SD). From this analysis of the spectral features of the investigated samples, it emerges that trehalose has a significant stabilizing effect on creatine aqueous solutions.

The Effect of Different Substrates on the Morphological Features and Polyols Production of Endomyces magnusii Yeast during Long-Lasting Cultivation

The study on the influence of different glucose concentrations (2%, 0.5%, and 0.2%) and glycerol (1%) on the morphological and physiological features, as well as the composition of soluble carbohydrates, was performed using Endomyces magnusii yeast. Two-factor analysis of variance with repetitions to process the data of the cell size changes showed that the substrate type affected cell size the most. The cells with 2% glucose were 30–35% larger than those growing on glycerol. The decrease in the initial glucose concentration up to 0.5–0.2% slightly changed the cell length. However, even in the logarithmic growth phase pseudo-mycelium of two to four cells appeared in the cultures when using low glucose, unlike those using glycerol. Throughout the whole experiment, more than 90% of the populations remained viable on all of the substrates tested. The ability for colony formation decreased during aging. Nevertheless, at the three-week stage, upon substrate restriction (0.2% glucose), it was twice higher than those under the other conditions. The respiration rate also decreased and exceeded not more than 10% of that in the logarithmic phase. By the end of the experiment, the cyanide-sensitive respiration share decreased up to 40% for all types of substrates. The study of soluble cytosol carbohydrates showed that the cultures using 2% glucose and 1% glycerol contained mainly arabitol and mannitol, while at low glucose concentrations they were substituted for inositol. The formation of inositol is supposed to be related to pseudo-mycelium formation. The role of calorie restriction in the regulation of carbohydrate synthesis and the composition in the yeast and its biotechnological application is under consideration.

Fruit Fly in a Challenging Environment: Impact of Short-Term Temperature Stress on the Survival, Development, Reproduction, and Trehalose Metabolism of Bactrocera dorsalis (Diptera: Tephritidae)

An understanding of physiological damage and population development caused by uncomfortable temperature plays an important role in pest control. In order to clarify the adaptability of different temperatures and physiological response mechanism of B. dorsalis, we focused on the adaptation ability of this pest to environmental stress from physiological and ecological viewpoints. In this study, we explored the relationship between population parameters and glucose, glycogen, trehalose, and trehalose-6-phosphate synthase responses to high and low temperatures. Compared with the control group, temperature stress delayed the development duration of all stages, and the survival rates and longevity decreased gradually as temperature decreased to 0 °C and increased to 36 °C. Furthermore, with low temperature decrease from 10 °C to 0 °C, the average fecundity per female increased at 10 °C but decreased later. Reproduction of the species was negatively affected during high-temperature stresses, reaching the lowest value at 36 °C. In addition to significantly affecting biological characteristics, temperature stress influenced physiological changes of B. dorsalis in cold and heat tolerance. When temperature deviated significantly from the norm, the levels of substances associated with temperature resistance were altered: glucose, trehalose, and TPS levels increased, but glycogen levels decreased. These results suggest that temperature stresses exert a detrimental effect on the populations' survival, but the metabolism of trehalose and glycogen may enhance the pest's temperature resistance.

PxTret1-like Affects the Temperature Adaptability of a Cosmopolitan Pest by Altering Trehalose Tissue Distribution

Global warming poses new challenges for insects to adapt to higher temperatures. Trehalose is the main blood sugar in insects and plays an important role in energy metabolism and stress resistance. The transmembrane transport of trehalose mainly depends on the trehalose transporter (TRET1). Plutella xylostella (L.) is a worldwide agricultural pest; however, the effects of the trehalose transport mechanism and trehalose distribution in tissues on the development, reproduction and temperature adaptation of P. xylostella have yet to be reported. In this study, PxTret1-like was cloned and analyzed regarding its expression pattern. It was found that the expression of PxTret1-like was affected by ambient temperature. The knockout mutation of PxTret1-like was generated using a CRISPR/Cas9 system by targeted knockout. The trehalose content and trehalase activity of mutant P. xylostella increased at different developmental stages. The trehalose content increased in the fat body of the fourth-instar P. xylostella, and decreased in the hemolymph, and there was no significant change in glucose in the fat body and hemolymph. Mutant strains of P. xylostella showed a significantly reduced survival rate, fecundity and ability to withstand extreme temperatures. The results showed that PxTret1-like could affect the development, reproduction and temperature adaptability of P. xylostella by regulating the trehalose content in the fat body and hemolymph.

Exploring the Potential of Myrothamnus flabellifolius Welw. (Resurrection Tree) as a Phytogenic Feed Additive in Animal Nutrition

Simple Summary

The unregulated use of in-feed antibiotic growth promoters has received widespread condemnation due to an increase in cases of antibiotic-resistant microbes. This has fueled an ever-growing demand for new sources of natural and safe alternative products with minimal impacts on the environment and human health in animal production. Myrothamnus flabellifolius, as a phytogenic feed additive, fits this description, as it is a natural plant containing high amounts of secondary metabolites necessary for cell function, regulation, and protection for improved animal growth, performance, and health. With some limitations towards its use, several processing and combination strategies are available to unlock nutrients and explore its potential in animal production, as described in this review.

Abstract

Myrothamnus flabellifolius (Welw.) is used in African traditional medicine for the treatment of depression and mental disorder, asthma, infectious diseases, respiratory, inflammation, epilepsy, heart, wound, backaches, diabetes, kidney ailments, hypertension, hemorrhoids, gingivitis, shingles, stroke, and skins conditions. The effectiveness of M. flabellifolius is due to the presence of several secondary metabolites that have demonstrated efficacy in other cell and animal models. These metabolites are key in cell regulation and function and have potential use in animal production due to antimicrobial and antioxidant properties, for an improvement in growth performance, feed quality and palatability, gut microbial environment, function, and animal health. The purpose of this review is to provide a detailed account on the potential use of M. flabellifolius in animal nutrition. Limitations towards the use of this plant in animal nutrition, including toxicity, economic, and financial issues are discussed. Finally, novel strategies and technologies, e.g., microencapsulation, microbial fermentation, and essential oil extraction, used to unlock and improve nutrient bioaccessibility and bioavailability are clearly discussed towards the potential use of M. flabellifolius as a phytogenic additive in animal diets.

Transcriptomic and Metabolomic Analysis of the Effects of Exogenous Trehalose on Salt Tolerance in Watermelon (Citrullus lanatus)

Trehalose can effectively protect the biomolecular structure, maintain the balance of cell metabolism, and improve the tolerance to various abiotic stresses in plants. However, the molecular mechanism underlying the improvement in salt tolerance by exogenous trehalose in watermelon (Citrullus lanatus) seedlings is still unclear. To understand these molecular mechanisms, in this study, watermelon seedlings under salt stress were treated with various concentrations of exogenous trehalose. An amount of 20 mM exogenous trehalose significantly improved the physiological status; increased the activities of enzymes such as POD, SOD, and CAT; and increased the K⁺/Na⁺ ratio in watermelon seedlings under salt stress. RNA-seq and metabolomic analysis were performed to identify the specifically expressed genes and metabolites after trehalose treatment. Watermelon seedlings were divided into salt stress (CK2), control (CK1) and trehalose treatment (T) groups as per the treatment. Overall, 421 shared differentially expressed genes (DEGs) were identified in the two comparison groups, namely CK2–CK1 and T–CK2. Functional annotation and enrichment analysis revealed that the DEGs were mainly involved in MAPK signaling pathway for plant hormone signal transduction and phenylpropanoid biosynthesis. Furthermore, 129 shared differential expressed metabolites (DEMs) were identified in the two comparison groups using liquid chromatography–mass spectrometry, which were mainly involved in the metabolic pathway and phenylpropanoid biosynthesis. The combined transcriptomic and metabolomic analyses revealed that genes involved in phenylpropanoid biosynthesis, plant hormone signal transduction, and carbohydrate biosynthesis pathways, especially bHLH family transcription factors, played an important role in improving salt tolerance of watermelon seedlings after exogenous trehalose treatment.

Cloning, expression and function analysis of trehalose-6-phosphate synthase gene from Marsupenaeus japonicu

Trehalose is an important disaccharide that plays an important role in extreme environmental conditions. Trehalose-6-phosphate synthase (TPS) gene is the key gene for trehalose synthesis in Marsupenaeus japonicus. In this study, a TPS gene was isolated and characterized from M. japonicus. The full-length cDNA of TPS gene of M. japonicus (MjTPS) was 3308 bp, encoding 844 amino acids. The protein of the deduced MjTPS contained a glycol_transf_20 domain and a trehalose_PPase domain. The mRNA expression level of MjTPS was the highest in hepatopancreas. The further analysis found that MjTPS gene expression was up-regulated in a short time under low-salinity and high-nitrite stress, indicating that MjTPS gene had certain resistance to low-salinity and high-nitrite stress. Compared with the control group, both the expression of MjTPS and the trehalose content significantly decreased from 3 h to 24 h after MjTPS gene interference,. After RNAi, the mortality of M. japonicus increased, the expression level of MjTPS and the synthesis of downstream products decreased under low-salinity and high-nitrite stress, and what's more, the expression of immune genes PMO25, ERP, CD, HSP90, HSP70, HSP60, HMC and CLEC2 were significantly changed, implying that MjTPS might be participated in the immune response of M. japonicus. In addition, MjTPS gene silencing could affect the expression of CHI1 and CHS, suggesting that MjTPS might be involved in molting behavior of M. japonicus. These results provide new information for further studying the function of trehalose-6-phosphate synthase in shrimp.

Genome-Wide Identification and Characterization of the Trehalose-6-phosphate Synthetase (TPS) Gene Family in Watermelon (Citrullus lanatus) and Their Transcriptional Responses to Salt Stress

With the increase in watermelon cultivation area, there is an urgent need to explore enzymatic and genetic resources for the sustainable development of watermelon, especially under salt stress. Among the various compounds known, trehalose plays an important role in regulating abiotic stress tolerances in diverse organisms, including plants. Therefore, the present study comprehensively analyzed the trehalose-6-phosphate synthase (TPS) gene family in watermelon. The study analyzed the functional classification, evolutionary characteristics, and expression patterns of the watermelon TPS genes family. Seven ClTPSs were identified and classified into two distinct classes according to gene structure and phylogeny. Evolutionary analysis suggested the role of purifying selection in the evolution of the TPS family members. Further, cis-acting elements related to plant hormones and abiotic stress were identified in the promoter region of the TPS genes. The tissue-specific expression analysis showed that ClTPS genes were widely expressed in roots, stems, leaves, flowers, and fruits, while ClTPS3 was significantly induced under salt stress. The overexpression of ClTPS3 in Arabidopsis thaliana significantly improved salt tolerance. Finally, the STRING functional protein association networks suggested that the transcription factor ClMYB and ClbHLH regulate ClTPS3. Thus, the study indicates the critical role of ClTPS3 in watermelon response to salt stress.

Role of Mono- and Disaccharide Combination in Cryoprotective Medium for Rooster Semen to Ensure Cryoresistance of Spermatozoa

The combination of saccharides in the composition of a cryopreservation medium may represent a promising method for the preservation of the reproductive cells of male birds. In the current study, cryoprotective media with a combined composition of mono- and di-saccharides were developed. The degree of penetration of reducing saccharide molecules (maltose—Mal20 medium) and non-reducing disaccharide molecules (trehalose—Treh20 medium) from the cryoprotective medium into the cytosol of rooster spermatozoa was studied. LCM control media without disaccharides were used as the control. The number of maltose molecules penetrating from the outside into the cytosol of the spermatozoon was 1.06 × 10⁴, and the number of trehalose molecules was 3.98 × 10⁴. Using a combination of maltose and fructose, the progressive motility of frozen/thawed semen and the fertility rates of eggs were significantly higher ((p < 0.05) 40.2% and 68.5%, respectively) than when using a combination of trehalose and fructose in a cryoprotective diluent (33.4% and 62.4%, respectively). A higher rate of chromatin integrity at the level of 92.4% was obtained when using Treh20 versus 74.5% Mal20 (p < 0.05). Maltose positively affected the preservation of frozen/thawed sperm in the genital tract of hens. On the seventh day from the last insemination when using Mal20, the fertilization of eggs was 42.6% and only 27.3% when using Treh20. Despite the same molecular weight, maltose and trehalose have different physicochemical and biological properties that determine their function and effectiveness as components of cryoprotective media.

Aspergillus niger trehalase enzyme induced morphological and protein alterations on Acanthamoeba cyst and molecular docking studies

The cytotoxicity of Acanthamoeba is yet to fully illustrate due to recalcitrant of Acanthamoeba during cyst stage. The formation of the trehalose layer at the cyst stage protects the inner components of this opportunist protozoan parasite. Trehalase from the Aspergillus niger (AnTre) activity on the cyst of Acanthamoeba was determined based on AnTre dose-response, morphological and protein changes. The interaction of the AnTre and trehalose was also visualized through docking simulation. Vacuolation of the cyst can be seen when observed under light microscopy. Membrane integrity assessment suggested possible hydrolization of the AnTre enzyme to trehalose membranes which based on acridine orange and propidium iodide staining. Surface morphology based on scanning electron microscopy revealed the formation of bulging structure that was also proved through cross sectioning observed by transmission electron microscopy. Loss of internal structure of the cysts was clearly observed. Other morphological distinction where loss of rigid shape due to the destruction of the endo- and ecto cyst layers. However, the protein profile exhibits change of trehalose layer as responses to AnTre treatment. The observed biological results were also supported by interaction simulation based on molecular docking between trehalose and AnTre enzyme. In conclusion, this enzymatic approach could be developed into selective and effective mechanism to control Acanthamoeba without affecting the host especially mammals due to the absence of trehalose elements in the tissues of mammals.

Chemical Composition and Potential Practical Application of 15 Red Algal Species from the White Sea Coast (the Arctic Ocean)

Though numerous valuable compounds from red algae already experience high demand in medicine, nutrition, and different branches of industry, these organisms are still recognized as an underexploited resource. This study provides a comprehensive characterization of the chemical composition of 15 Arctic red algal species from the perspective of their practical relevance in medicine and the food industry. We show that several virtually unstudied species may be regarded as promising sources of different valuable metabolites and minerals. Thus, several filamentous ceramialean algae (Ceramium virgatum, Polysiphonia stricta, Savoiea arctica) had total protein content of 20-32% of dry weight, which is comparable to or higher than that of already commercially exploited species (Palmaria palmata, Porphyra sp.). Moreover, ceramialean algae contained high amounts of pigments, macronutrients, and ascorbic acid. Euthora cristata (Gigartinales) accumulated free essential amino acids, taurine, pantothenic acid, and floridoside. Thalli of P. palmata and C. virgatum contained the highest amounts of the nonproteinogenic amino acid β-alanine (9.1 and 3.2 μM g-1 DW, respectively). Several red algae tend to accumulate heavy metals; although this may limit their application in the food industry, it makes them promising candidates for phytoremediation or the use as bioindicators.

Bradyrhizobium diazoefficiens Requires Chemical Chaperones To Cope with Osmotic Stress during Soybean Infection

When engaging in symbiosis with legume hosts, rhizobia are confronted with environmental changes, including nutrient availability and stress exposure. Genetic circuits allow responding to these environmental stimuli to optimize physiological adaptations during the switch from the free-living to the symbiotic life style. A pivotal regulatory system of the nitrogen-fixing soybean endosymbiont Bradyrhizobium diazoefficiens for efficient symbiosis is the general stress response (GSR), which relies on the alternative sigma factor σEcfG However, the GSR-controlled process required for symbiosis has not been identified. Here, we demonstrate that biosynthesis of trehalose is under GSR control, and mutants lacking the respective biosynthetic genes otsA and/or otsB phenocopy GSR-deficient mutants under symbiotic and selected free-living stress conditions. The role of trehalose as a cytoplasmic chemical chaperone and stress protectant can be functionally replaced in an otsA or otsB mutant by introducing heterologous genetic pathways for biosynthesis of the chemically unrelated compatible solutes glycine betaine and (hydroxy)ectoine. Alternatively, uptake of exogenously provided trehalose also restores efficient symbiosis and tolerance to hyperosmotic and hyperionic stress of otsA mutants. Hence, elevated cytoplasmic trehalose levels resulting from GSR-controlled biosynthesis are crucial for B. diazoefficiens cells to overcome adverse conditions during early stages of host infection and ensure synchronization with root nodule development.IMPORTANCE The Bradyrhizobium-soybean symbiosis is of great agricultural significance and serves as a model system for fundamental research in bacterium-plant interactions. While detailed molecular insight is available about mutual recognition and early nodule organogenesis, our understanding of the host-imposed conditions and the physiology of infecting rhizobia during the transition from a free-living state in the rhizosphere to endosymbiotic bacteroids is currently limited. In this study, we show that the requirement of the rhizobial general stress response (GSR) during host infection is attributable to GSR-controlled biosynthesis of trehalose. Specifically, trehalose is crucial for an efficient symbiosis by acting as a chemical chaperone to protect rhizobia from osmostress during host infection.

A head-to-head comparison review of biological and toxicological studies of isomaltulose, d-tagatose, and trehalose on glycemic control

Diabetes mellitus is the most common metabolic disorder contributing to significant morbidity and mortality in humans. Different preventive and therapeutic agents, as well as various pharmacological strategies or non-pharmacological tools, improve the glycemic profile of diabetic patients. Isomaltulose, d-tagatose, and trehalose are naturally occurring, low glycemic sugars that are not synthesized by humans but widely used in food industries. Various studies have shown that these carbohydrates can regulate glucose metabolism and provide support in maintaining glucose homeostasis in patients with diabetes, but also can improve insulin response, subsequently leading to better control of hyperglycemia. In this review, we discussed the anti-hyperglycemic effects of isomaltulose, D-tagatose, and trehalose, comparing their properties with other known sweeteners, and highlighting their importance for the development of the pharmaceutical and food industries.

Effects of Saccharides Supplementation in the Extender of Cryopreserved Rooster (Gallus domesticus) Semen on the Fertility of Frozen/Thawed Spermatozoa

The aim of this study was to create balanced media for the cryopreservation of rooster semen in pellets to maintain the functional state of the sperm after thawing. Fructose was replaced by trehalose in experimental media in proportions of 10% (LCM-T10) and 20% (LCM-T20), while LCM was used as a control. After artificial insemination of the hens, the eggs were incubated (n = 400). To determine the functional safety of spermatozoa in the genital tract of hens after 5, 10, and 15 days from the last insemination, we used a method for assessing the interaction of sperm with the perivitelline membrane. Significantly higher rates of egg fertilization (82-86%) were obtained when using LCM-T10 and LCM-T20 compared to control (79%, p < 0.05). Egg fertility on the 5th day from the last insemination with the LCM-T20 diluent reached 100% versus 86% in the control; on the 10th day, the fertility rates were 55% versus 20%, respectively. The best results for fertility duration were obtained by freezing spermatozoa with LCM-T20 medium. The numbers of interaction points of spermatozoa with the perivitelline membrane were as follows: on the 5th day from the last insemination with LCM-T20-461.5 ± 11.5 holes/cm² (LCM-control-13.7 ± 2.7 holes/cm²), p < 0.01; on the 10th day with LCM-T20-319.3 ± 12.9 holes/cm² (LCM-control-14.9 ± 3.5 holes/cm²); and on the 15th day with LCM-T20-345.2 ± 11.1 holes/cm² (LCM-control-0 holes/cm²). In conclusion, the use of trehalose in LCM diluent medium can increase the fertility of frozen/thawed sperm and the duration of their fertility in the genital tract of hens.

Short-Distance Intermolecular Correlations of Mono- and Disaccharides in Condensed Solutions: Bulky Character of Trehalose

Organisms with tolerance to extreme environmental conditions (cryptobiosis) such as desiccation and freezing are known to accumulate stress proteins and/or sugars. Trehalose, a disaccharide, has received considerable attention in the context of cryptobiosis. It has already been shown to have the highest glass-transition temperature and different hydration properties from other mono- and disaccharides. In spite of the importance of understanding cryptobiosis by experimentally clarifying sugar-sugar interactions such as the clustering in concentrated sugar solutions, there is little direct experimental evidence of sugar solution structures formed by intermolecular interactions and/or correlation. Using a wide-angle X-ray scattering method with the real-space resolution from ∼3 to 120 Å, we clarified the characteristics of the structures of sugar solutions (glucose, fructose, mannose, sucrose, and trehalose), over a wide concentration range of 0.05-0.65 g/mL. At low concentrations, the second virial coefficients obtained indicated the repulsive intermolecular interactions for all sugars and also the differences among them depending on the type of sugar. In spite of the presence of such repulsive force, a short-range intermolecular correlation was found to appear at high concentrations for every sugar. The concentration dependence of the observed scattering data and p(r) functions clearly showed that trehalose prefers a more disordered arrangement in solution compared to other sugars, that is, bulky arrangement. The present findings will afford a new insight into the molecular mechanism of the protective functions of the sugars relevant to cryptobiosis, particularly that of trehalose.

Permeabilized TreS-Expressing Bacillus subtilis Cells Decorated with Glucose Isomerase and a Shell of ZIF-8 as a Reusable Biocatalyst for the Coproduction of Trehalose and Fructose

Metal-organic frameworks (MOFs) are a class of porous materials with versatile properties. In this study, ZIF-8 was employed to establish a two-enzyme system by encapsulating permeabilized Bacillus subtilis cells coated with glucose isomerase. B. subtilis was constructed by introducing the shuttle plasmid PMA5 associated with the overexpression of trehalose synthase. Using this two-enzyme system, trehalose was produced by trehalose synthase and the byproduct glucose was converted to fructose with the help of glucose isomerase. The decrease in glucose production not only relieved the inhibition of the entire reaction chain but also increased the final yield of trehalose. The highest trehalose production rate reached 67.7% and remained above 50% after 20 batches. In addition, the toxicity of the ZIF-8 coating for B. subtilis was investigated by fluorescence microscopy and was found to be negligible. By simulating an extreme environment, the ZIF-8 coating was demonstrated to have a protective effect on the cells and enzymes. This study provides a theoretical basis for the application of MOFs in the immobilization of microorganisms and enzymes.

RNA interference of a trehalose-6-phosphate synthase gene reveals its roles in the biosynthesis of chitin and lipids in Heortia vitessoides (Lepidoptera: Crambidae)

Trehalose-6-phosphate synthase (TPS), an enzyme that hydrolyzes two glucose molecules to yield trehalose, plays a pivotal role in various physiological processes. In this study, we cloned the trehalose-6-phosphate synthase gene (HvTPS) and investigated its expression patterns in various tissues and developmental stages in Heortia vitessoides Moore (Lepidoptera: Crambidae). HvTPS was highly expressed in the fat body and after pupation or before molting. We knocked down TPS in H. vitessoides by RNA interference and found that 3.0 μg of dsHvTPS resulted in optimal interference at 24 h and 36 h post-injection and caused a sharp decline in the survival rate during the 5th instar larval-pupal stage and obviously abnormal or lethal phenotypes. Additionally, compared to the controls, TPS activity and trehalose contents were significantly lower and the glucose content was significantly higher 24 h or 36 h after injection with 3.0 μg of dsHvTPS. Furthermore, the silencing of HvTPS suppressed the expression of six key genes in the chitin biosynthesis pathway and one key gene related to lipid catabolism. The expression levels of two genes associated with lipid biosynthesis were upregulated. These results strongly suggest that HvTPS is essential for the normal growth and development of H. vitessoides and provide a reference for further studies of the utility of key genes involved in chitin and lipid biosynthesis for controlling insect development.

Characterization of trehalose-6-phosphate phosphatase in trehalose biosynthesis, asexual development, stress resistance and virulence of an insect mycopathogen

Biological control potential of entomopathogenic fungi depending on conidiation capacity, conidial stress tolerance and virulence can be improved through genetic engineering. To explore a possible role of trehalose biosynthesis pathway in improving fungal pest-control potential, we characterized biological functions of trehalose-6-phosphate phosphatase (BbTPP) in Beauveria bassiana, an insect mycopathogen that serves as a main source of fungal insecticides. Deletion of BbTPP resulted in abolished trehalose biosynthesis, reduced conidiation capacity, decreases in conidial thermotolerance and UV-B resistance, increased hyphal sensitivities to chemical stresses, and attenuated virulence. By contrast, over-expression of BbTPP led to increased trehalose accumulation, decreased T6P accumulation, and enhanced stress tolerance and virulence despite little impact on growth and conidiation under normal conditions. These results indicate that BbTPP serves as not only a key player in control of trehalose biosynthesis required for multiple cellular functions but also a potential candidate to be exploited for genetic improvement of fungal potential against insect pests.

The influence of the carbohydrate levels on viability of Stagonospora cirsii drying mycelium

The Stagonospora cirsii mycelium is considered as the infectious basis of a potential mycoherbicide for the control of Canadian thistle and perennial sow thistle. Successful commercialization of mycoherbicides is often constrained by poor drying survival. In this study was shown that the highest viability of mycelium S. cirsii during drying is achieved in the stationary phase of growth. The mycelium in the stationary phase is characterized by maximum level of carbohydrates. We suggest the level of arabitol as a criterion evaluation of the mycelium resistance to drying. Culturing conditions, and especially the fermentation time, allow prediction of polyols and trehalose levels, which are very critical in enhancing the storage life and efficacy of biological control agent.

Synthesis of trehalose glycolipids

Chemical synthesis of trehalose glycolipids such as DAT, TDM, SL-1, SL-3, and Ac₂SGL from MTb, emmyguyacins from fungi, succinoyl trehalose from rhodococcus, and maradolipids from worms, as well as mycobacterial oligosaccharides is reviewed.

Molecular mechanisms of trehalose in modulating glucose homeostasis in diabetes

Diabetes mellitus is the most prevalent metabolic disorder contributing to significant morbidity and mortality in humans. Many preventative and therapeutic agents have been developed for normalizing glycemic profile in patients with diabetes. In addition to various pharmacologic strategies, many non-pharmacological agents have also been suggested to improve glycemic control in patients with diabetes. Trehalose is a naturally occurring disaccharide which is not synthesized in human but is widely used in food industries. Some studies have provided evidence indicating that it can potentially modulate glucose metabolism and help to stabilize glucose homeostasis in patients with diabetes. Studies have shown that trehalose can significantly modulate insulin sensitivity via at least 7 molecular pathways leading to better control of hyperglycemia. In the current study, we concluded about possible anti-hyperglycemic effects of trehalose suggesting trehalose as a potentially potent non-pharmacological agent for the management of diabetes.

Investigating trehalose synthesis genes after cold acclimation in the Antarctic nematode Panagrolaimus sp. DAW1

Panagrolaimus sp. DAW1 is a freeze-tolerant Antarctic nematode which survives extensive intracellular ice formation. The molecular mechanisms of this extreme adaptation are still poorly understood. We recently showed that desiccation-enhanced RNA interference (RNAi) soaking can be used in conjunction with quantitative polymerase chain reaction (qPCR) to screen for phenotypes associated with reduced expression of candidate genes in Panagrolaimus sp. DAW1. Here, we present the use of this approach to investigate the role of trehalose synthesis genes in this remarkable organism. Previous studies have shown that acclimating Panagrolaimus sp. DAW1 at 5°C before freezing or desiccation substantially enhances survival. In this study, the expression of tps-2 and other genes associated with trehalose metabolism, as well as lea-1, hsp-70 and gpx-1, in cold-acclimated and non-acclimated nematodes was analyzed using qPCR. Pd-tps-2 and Pd-lea-1 were significantly upregulated after cold acclimation, indicating an inducible expression in the cold adaptation of Panagrolaimus sp. DAW1. The role of trehalose synthesis genes in Panagrolaimus sp. DAW1 was further investigated by RNAi. Compared to the controls, Pd-tps-2a(RNAi)-treated and cold-acclimated nematodes showed a significant decrease in mRNA, but no change in trehalose content or freezing survival. The involvement of two other trehalose synthesis genes (tps-2b and gob-1) was also investigated. These findings provide the first functional genomic investigation of trehalose synthesis genes in the non-model organism Panagrolaimus sp. DAW1. The presence of several trehalose synthesis genes with different RNAi sensitivities suggests the existence of multiple backup systems in Panagrolaimus sp. DAW1, underlining the importance of this sugar in preparation for freezing.

Summary: Functional genomics was used to investigate trehalose synthesis genes after cold acclimation in Panagrolaimus sp. DAW1, an Antarctic nematode with the ability to survive intracellular freezing.