Hydrolyzed Form Research Articles

P53-driven lipidome influences non-cell-autonomous lysophospholipids in pancreatic cancer

Adaptation of the lipid metabolism participates in cancer pathogenesis, facilitating energy storage and influencing cell fate and control of molecular signalling. The tumour suppressor protein p53 is a molecular hub of cell metabolism, supporting antioxidant capabilities and counteracting oncogene-induced metabolic switch. Despite extensive work has described the p53-dependent metabolic pathways, a global profiling of p53 lipidome is still missing. By high-throughput untargeted lipidomic analysis of pancreatic ductal adenocarcinoma (PDAC) cells, we profile the p53-dependent lipidome, revealing intracellular and secreted lysophospholipids as one of the most affected class. Lysophospholipids are hydrolysed forms of phospholipids that results from phospholipase activity, which can function as signalling molecules, exerting non-cell-autonomous effects and instructing cancer microenvironment and immunity. Here, we reveal that p53 depletion reduces abundance of intracellular lysophosphatidyl-choline, -ethanolamine and -serine and their secretion in the extracellular environment. By integrating this with genomic and transcriptomic studies from in vitro models and human PDAC patients, we identified potential clinically relevant candidate p53-dependent phospholipases. In particular PLD3, PLCB4 and PLCD4 expression is regulated by p53 and chromatin immunoprecipitation followed by deep sequencing (ChIP-seq) indicates a direct transcriptional control on their chromatin accessible genomic loci. Consistently, PLD3, PLCB4 and PLCD4 expression correlates with p53 mutational status in PDAC patients, and these genes display prognostic significance. Overall, our data provide insights into lipidome rewiring driven by p53 loss and identify alterations of lysophospholipids as a potential molecular mechanism for p53-mediated non-cell-autonomous molecular signalling that instructs cancer microenvironment and immunity during PDAC pathogenesis.

Efficacy of Fumonisin Esterase in Piglets as Animal Model for Fumonisin Detoxification in Humans: Pilot Study Comparing Intraoral to Intragastric Administration

Fumonisins, a group of highly prevalent and toxic mycotoxins, are suspected to be causal agents of several diseases in animals and humans. In the animal feed industry, fumonisin esterase is used as feed additive to prevent mycotoxicosis caused by fumonisins. In humans, a popular dosage form for dietary supplements, with high patient acceptance for oral intake, is capsule ingestion. Thus, fumonisin esterase provided in a capsule could be an effective strategy against fumonisin intoxication in humans. To determine the efficacy of fumonisin esterase through capsule ingestion, two modes of application were compared using piglets in a small-scale preliminary study. The enzyme was administered intraorally (in-feed analogue) or intragastrically (capsule analogue), in combination with fumonisin B1 (FB1). Biomarkers for FB1 exposure; namely FB1, hydrolysed FB1 (HFB1) and partially hydrolysed forms (pHFB1a and pHFB1b), were measured both in serum and faeces using a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method, and toxicokinetic parameters were calculated. Additionally, the serum sphinganine/sphingosine (Sa/So) ratio, a biomarker of effect, was determined using LC-MS/MS. A significantly higher Sa/So ratio was shown in the placebo group compared to both esterase treatments, demonstrating the efficacy of the esterase. Moreover, a significant decrease in serum FB1 area under the concentration-time curve (AUC) and an increase of faecal HFB1 AUC were observed after intraoral esterase administration. However, these effects were not observed with statistical significance after intragastric esterase administration with the current sample size.

Marine microbial enzymes for the production of algal oligosaccharides and its bioactive potential for application as nutritional supplements.

Marine macroalgae have a very high carbohydrate content due to complex algal polysaccharides (APS) like agar, alginate, and ulvan in their cell wall. Despite numerous reports on their biomedical properties, their hydrocolloid nature limits their applications. Algal oligosaccharides (AOS), which are hydrolyzed forms of complex APS, are gaining importance due to their low molecular weight, biocompatibility, bioactivities, safety, and solubility in water that makes it a lucrative alternative. The AOS produced through enzymatic hydrolysis using microbial enzymes have far-reaching applications because of its stereospecific nature. Identification and characterization of novel microorganisms producing APS hydrolyzing enzymes are the major bottlenecks for the efficient production of AOS. This review will discuss the marine microbial enzymes identified for AOS production and the bioactive potential of enzymatically produced AOS. This can improve our understanding of the biotechnological potential of microbial enzymes for the production of AOS and facilitate the sustainable utilization of algal biomass. Enzymatically produced AOS are shown to have bioactivities such as antioxidant, antiglycemic, prebiotic, immunomodulation, antiobesity or antihypercholesterolemia, anti-inflammatory, anticancer, and antimicrobial activity. The myriad of health benefits provided by the AOS is the need of the hour as there is an alarming increase in physiological disorders among a wide range of the global population.

Sorption of Yb(III) from aqueous solution on Na-clinoptilolite

The sorptive properties of the Na-modified Transcarpathian clinoptilolite towards Yb(III) under dynamic conditions were investigated. The sorption capacity of the Na-form of Transcarpathian clinoptilolite towards Yb(III) significantly depends on the concentration of ytterbium salt, the pH of solution and the temperature of the preliminary calcination of the sorbent. The buffer solution has been used to maintain the constant value of pH, ioniс strength of the solutions and to improve the metrological characteristics of preconcentration methods of Yb. The trace amounts of Yb(III) most effectively are sorbed with borate buffer solution. The final concentration of the borate buffer in the sample solution is 4·10 - 4 М. The sorption capacity of Na-clinoptilolite under optimal conditions (diameter of zeolite grains was 0.20–0.31 mm; flow rate of ytterbium(III) solution with concentration 1.0 µg/mL through sorbent was 5 mL/min; temperature of preliminary thermal treatment ~ 50 ºC and pH 9.5) was 8.1 mg ytterbium per 1 g of Na-modified clinoptilolite. The sorption of Yb(III) is carried out mainly by means of the adsorption of soluble hydrolyzed forms of Yb(III) on the zeolite surface. The influence of the most common water ions on the preconcentration of Yb(III) on the Na-form of Transcarpathian clinoptilolite has been established. The solutions of 1 M KCl acidified by a hydrochloric acid to pH 4.0 are the most effective desorbents of ytterbium(III) ions from Na-clinoptilolite. It provides a 99 % withdrawal of Yb from the zeolite matrix. The method for ytterbium trace amounts preconcentration from aqueous solutions in a solid phase extraction mode with a further determination of this rare earth element by a spectrophotometric method was developed. Keywords: sorption, solid phase extraction, ytterbium, Na-clinoptilolite.

2-Aminobenzoxazole-appended coumarins as potent and selective inhibitors of tumour-associated carbonic anhydrases

We have carried out the design, synthesis, and evaluation of a small library of 2-aminobenzoxazole-appended coumarins as novel inhibitors of tumour-related CAs IX and XII. Substituents on C-3 and/or C-4 positions of the coumarin scaffold, and on the benzoxazole moiety, together with the length of the linker connecting both units were modified to obtain useful structure-activity relationships. CA inhibition studies revealed a good selectivity towards tumour-associated CAs IX and XII (K i within the mid-nanomolar range in most of the cases) in comparison with CAs I, II, IV, and VII (K i > 10 µM); CA IX was found to be slightly more sensitive towards structural changes. Docking calculations suggested that the coumarin scaffold might act as a prodrug, binding to the CAs in its hydrolysed form, which is in turn obtained due to the esterase activity of CAs. An increase of the tether length and of the substituents steric hindrance was found to be detrimental to in vitro antiproliferative activities. Incorporation of a chlorine atom on C-3 of the coumarin moiety achieved the strongest antiproliferative agent, with activities within the low micromolar range for the panel of tumour cell lines tested.

The Regenerative Role of Gelatin in PLLA Electrospun Membranes for the Treatment of Chronic Massive Rotator Cuff Injuries.

Failing to regenerate native tendon tissue in chronic massive rotator cuff tears (CMRCTs) results in high retear rates after surgery. Gelatin is a hydrolyzed form of collagen which is bioactive and biocompatible. This study intends to investigate the suitability of integrating gelatin to poly (l-lactic acid) (PLLA) fibrous membranes for promoting the healing of CMRCTs. PLLA/Gelatin electrospun membranes (PGEM) are fabricated using electrospinning technology. The fourier transform infrared, static contact angles are tested sequentially. Cytocompatibility is evaluated with rat tendon fibroblasts and human umbilical endothelial cells (HUEVCs) lines. CMRCTs rat models are established and assigned into three groups (the sham group, the repaired group, and the augmentation group) to perform histomorphological and biomechanical evaluations. Gelatin is successfully integrated into PLLA fibrous membranes by the electrospinning technique. In vitro studies indicate that PGEM shows a great cytocompatibility for rat tendon fibroblasts and HUEVCs. In vivo studies find that applications of PGEM significantly promote well-aligned collagen I fibers formation and enhance biomechanical properties of the repaired tendon in CMRCTs rat models. In summary, gelatin promotes tendon fibroblasts and HUEVCs adhesion, migration, and proliferation on the PLLA fibrous membranes, and PGEM may provide a great prospect for clinical application.

Macrophage Polarization Related to Crystal Phases of Calcium Phosphate Biomaterials.

Calcium phosphate (CaP) materials influence macrophage polarization during bone healing. However, the effect of the crystal phase of CaP materials on the immune response of bone remains unclear. In this study, the effect of the crystal phases of CaP materials on the regulation of macrophage polarization was investigated. Human THP-1 cells and mouse RAW 264 cells were cultured with octacalcium phosphate (OCP) and its hydrolyzed form Ca-deficient hydroxyapatite to assess the expression of pro-inflammatory M1 and anti-inflammatory M2 macrophage-related genes. OCP inhibited the excessive inflammatory response and switched macrophages to the anti-inflammatory M2 phenotype, which promoted the expression of the interleukin 10 (IL10) gene. In contrast, HL stimulated an excessive inflammatory response by promoting the expression of pro-inflammatory M1 macrophage-related genes. To observe changes in the microenvironment induced by OCP and HL, inorganic phosphate (Pi) and calcium ion (Ca2+) concentrations and pH value in the medium were measured. The expression of the pro-inflammatory M1 macrophage-related genes (tumor necrosis factor alpha (TNFα) and interlukin 1beta (IL1β)) was closely related to the increase in ion concentration caused by the increase in the CaP dose. Together, these results suggest that the microenvironment caused by the crystal phase of CaP materials may be involved in the immune-regulation capacity of CaP materials.

Combining Experimental Data with Statistical Methods to Evaluate Hydrolyzed Reactive Dye Removal by α-Fe2O3 in a Cellulose-Based Membrane

Water contaminated with toxic dyes poses serious problems for human health and environmental ecosystems. Unfixed reactive dyes and their hydrolyzed form are soluble in water, thus, their removal is particularly challenging. Among the different methodologies, adsorption is probably the most common since it is easy to handle and has a low cost. Here, the removal by adsorption of hydrolyzed Reactive Black 5 (hydRB5) from a model wastewater through cellulose acetate/hematite membranes (CA/α-Fe2O3), designated as M1, M2 and M3, was performed. The pristine cellulose acetate membrane (CA) was designated as M0. Toward understanding the adsorption mechanism of hydRB5 on membranes, the rate of adsorption and maximum value of the adsorption capacity were evaluated using kinetic and isothermal studies, respectively. The results showed that the adsorption mechanism follows pseudo-first-order kinetics, and data are best fitted by the Langmuir isotherm method with a maximum adsorption capacity of 105.26 mg g−1 in pH~7. Furthermore, these membranes can be also regenerated by washing with NaOH and NaCl solutions, and the regeneration efficiency remains effective over five cycles. To complete the work, two statistical models were applied, an Analysis of Variance (ANOVA) and a Response Surface Methodology (RSM). The optimum value found is located in the usable region, and the experimental validation shows good agreement between the predicted optimum values and the experimental data. These composite membranes are also good candidates for the adsorption of other pollutants, even at industrial scale, due to their effective regeneration process and low production costs.

Qualitative and quantitative estimation of Diosgenin in coded ayurvedic formulation and its ingredient Trigonella foenum-graecum Linn. seeds used in diabetics

BackgroundTrigonella foenum-graecum (Methi) is a leguminous plant and botanically known as Trigonella foenum-graecum Linn, belong to the family Fabaceae. Trigonella foenum-graecum is used for a variety of health conditions, including digestive problems, bronchitis, tuberculosis, fevers, sore throats, wounds, arthritis, abscesses, swollen glands, skin irritations, diabetes, loss of appetite, ulcers, and menopausal symptoms, as well as in the treatment of cancer. Trigonella foenum-graecum seeds mainly contain Diosgenin [(3β,25R)-spirost-5-en3-ol], a plant-derived steroid sapogenin.ResultsThe identification and quantification results by HPTLC and HPLC studies of Trigonella foenum-graecum seeds hydrolysed Trigonella foenum-graecum seeds, coded formulation, hydrolysed coded formulation extract with standard Diosgenin biomarker showed a significant highest peak in hydrolysed Trigonella foenum-graecum seeds and hydrolysed coded formulation. The standard Diosgenin is observed in the hydrolysed form of hydrolysed Trigonella foenum-graecum seeds and hydrolysed coded formulation. The literature on Trigonella foenum-graecum confirms its activity as antidiabetic, and the peak of standard biomarker Diosgenin is seen after derivatization with anisaldehyde sulphuric agent, which possesses medicinal phytoconstituents value. Further related to future scientific aspects, more studies on its potent antidiabetic activity and multipurpose action need to be carried out with medicinal composition and its effects on the human body.ConclusionThis study aims to establish the qualitative and quantitative estimation of standard Diosgenin in reliable with coded ayurvedic formulation and Trigonella foenum-graecum seeds and its activity as antidiabetic by HPTLC and HPLC.

Investigation of structural and physico-chemical properties of rice starch with varied amylose content: A combined microscopy, spectroscopy, and thermal study

Starch from a given botanical source can vary considerably in terms of physicochemical properties in its native and hydrolyzed forms. The current study investigated the structural and functional characteristics of starch from ten indigenous rice varieties endemic to Northeast India. In vitro enzymatic hydrolysis was used to reveal the dextrose equivalent profile of each type of starch. Gezep Sali and Betguti Sali respectively exhibited the highest and lowest starch hydrolysis. Among the ten rice varieties, amylose content varied between 7.50 and 28.58%. Optical and scanning electron microscopy (SEM) revealed the polyhedral shape of the native starch granules and deformation of the shape upon enzymatic hydrolysis. Second harmonic generation (SHG) microscopy and X-ray diffraction (XRD) analysis confirmed the presence of and variations in starch crystallinity. XRD revealed spectral peaks characteristic of A-type starch crystals in the native form. The elevated intensity of XRD peaks in hydrolyzed starch granules confirmed the occurrence of amylose hydrolysis rather than hydrolysis in amylopectin regions. Fourier transform infrared (FTIR) spectra revealed the common stretching and bending of bonds in all native starches; however, changes were observed in the fingerprint region (1080, 1000, 926 cm−1) of hydrolyzed starch granules, which indicates the amylolysis of the amylose region and disturbances in the ordered arrangement in the crystalline part. Differential scanning calorimeter (DSC) endotherms revealed the highest and lowest gelatinization peak temperatures in Harfoni (78 °C) and Tulosi Sali (41 °C) rice cultivars, respectively. The findings in this study can help to optimize the usage of rice starch in food and non-food industries. Furthermore, understanding the control points of starch digestion and genetically tailoring rice grains with different digestibility could be beneficial for nutraceutical applications.

Styrene intermolecular associating incorporated-polyacrylamide flooding of crude oil in carbonate coated micromodel system at high temperature, high salinity condition: Rheology, wettability alteration, recovery mechanisms

Polymer flooding is one of the most well-known research interests in the enhanced oil recovery (EOR) due to the excess oil production and limited petroleum reserve. Commercial polymers such as polyacrylamide (PAM) and its hydrolyzed form (HPAM) can be easily degraded at high temperature, high salinity, and high shear rate in attempt to the EOR purposes for the harsh reservoir conditions. In this work, a hydrophobically modified copolymer consisting of acrylamide and styrene (HSPAM) was produced via inverse emulsion polymerization as a wettability modifier and viscosifying agent, applicable under harsh reservoir conditions to direct insights into the synergic oil recovery pore scale mechanisms and overcoming the aforementioned challenges through the EOR process. In the first part of this study, a set of analytical techniques including FTIR, NMR, TGA, and molecular weight measurement was carried out, confirming successfully incorporation of styrene monomer in water-soluble skeleton and higher thermal resistivity of HSPAM compared with HPAM. By analyzing the rheological behavior of HSPAM under harsh reservoir conditions, it was found that the viscosity of HSPAM aqueous solution was increasingly influenced by the total dissolved solids, even up to 40,572 mg/L. In the second part, stability tests, contact angle (CA), interfacial tension (IFT), and carbonate coated glass micromodel flooding experiments were conducted by deionized water (DIW), seawater (SW) and formation brine (FB) in the absence and presence of HSPAM and HPAM. HSPAM illustrated a great stability in seawater and formation brine in comparison with HPAM after 120 days at 80 °C. The presence of HSPAM in seawater resulted in a more water-wet state up to 42° compared to HPAM by contact angle of 31° after 72 h. Findings provided synergic oil recovery mechanisms approved by emulsification and coalition phenomena to show a better wettability alteration and IFT reduction for HSPAM in spite of HPAM alongside drastically improving the brine-based flooding performance, yielding an ultimate recovery of about 82% original oil in place (OOIP).

Optimization and Validation of an Analytical Method for the Determination of Free and Hidden Fumonisins in Corn and Corn Products by UHPLC-MS/MS

Fumonisins are mycotoxins and corn has been considered the foodstuff presenting the highest contamination levels by these compounds. In recent years, the presence of hidden fumonisins in corn and corn products has aroused the interest of public health authorities. The aim of this study was to optimize and validate a simple and fast analytical method for the determination of free and hidden fumonisins in corn and corn products by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Several sample treatment methods were assessed for free fumonisins determination, and a method using rapid shaking and sonication, followed by extract dilution without the need for a clean-up step was selected for validation. Hidden fumonisins determination was based on the hydrolyzed forms (HFB1 + HFB2) obtained after sample alkaline hydrolysis. The alkaline hydrolysis efficiency was optimized, with a final selected shaking time of 60 min. Satisfactory recoveries were obtained for the target mycotoxins in the validated method, ranging from 89 to 110%, with relative standard deviations lower than 14%. Linearity was confirmed for the calibration curves at the assessed concentration ranges. The method sensitivity was considered adequate, with limits of quantification ranging from 0.4 μg kg−1 to 17.8 μg kg−1. The proposed analytical method was applied satisfactorily to the analysis of real samples, being considered attractive for routine analyses.

Potential utilization of fish waste for the sustainable production of microalgae rich in renewable protein and phycocyanin-Arthrospira platensis/Spirulina

The fish processing industry generates the solid biological waste (head, trimmings, skin, viscera, scale, bone etc) based on the processing methods, which poses a serious effect on the environment. Fish waste is valorized by various treatment methods which are costly and generate the effluents with high organic load. The objective of the present study was to utilize the fish waste in the form of fish protein hydrolysate (FPH) as an organic nitrogen source for the cultivation of Spirulina instead of inorganic nitrogen. Since the inorganic nitrogen in the algal cultivation accounts for high costs and energy, in addition to the continuous discharge of unspent inorganic nitrogen causing severe environmental problems. The proposed organic nutrient could be a sustainable and environment friendly solution from both the perspective of fish waste valorization and Spirulina cultivation. The proximate and amino acid composition of FPH derived from fish waste were characterized. Inorganic nitrogen (sodium nitrate) in the conventional medium was replaced with different concentrations of FPH varying from 0.1 to 1% (v/v). The effect of various concentrations of FPH on the growth, biomass productivity, biochemical composition and pigments of Spirulina were investigated. FPH concentration of 0.5% enhanced dry cell weight (DCW), biomass productivity (Pb), protein, and phycocyanin content by 34%, 39% and 15% and 98% respectively, compared to the conventional Zarrouk medium (control). Increase in the FPH concentration decreased the in vitro digestibility of the protein. The carbohydrate content and theoretical ethanol production were 5 times higher in the 0.1% FPH concentration than that of control. Results showed that the fish waste in the form of FPH could be a potential organic nitrogen for the cultivation of Spirulina with high quality pigment. Finally, a preliminary sustainability assessment has been made to analyze the bioeconomy of the process.

The Current State of Research on PET Hydrolyzing Enzymes Available for Biorecycling

This short paper reviews two groups of enzymes designated as polyethylene terephthalate (PET) hydrolases: one consists of thermophilic cutinases from thermophilic microorganisms (actinomycetes and a fungus) and the other consists of mesophilic cutinases, the representative of which is IsPETase from a mesophilic bacterium. From the viewpoint that PET hydrolysis requires a high temperature close to the glass transition temperature (65–70 °C in water) of PET, mesophilic cutinases are not suitable for use in the enzymatic recycling of PET since their degradation level is one to three orders of magnitude lower than that of thermophilic cutinases. Many studies have attempted to increase the thermostability of IsPETase by introducing mutations, but even with these modifications, the mesophilic cutinase does not reach the same level of degradation as thermophilic cutinases. In addition, this kind of trial contradicts the claim that IsPETase works at ambient temperature. As plastic pollution is an urgent environmental issue, scientists must focus on feasible thermophilic enzymes for the enzymatic processing of disposed PET, rather than on mesophilic cutinases. Thermophilic and mesophilic cutinases must be evaluated precisely and comparatively, based on their features that enable them to hydrolyze PET, with the aim of enzymatic PET disposal. The level of thermophilic cutinases has already reached their optimal level in PET biorecycling. The optimal level may be reached through the processing of PET waste, by amorphization and micronization into readily hydrolysable forms and the improvement of PET hydrolases by engineering higher degradation ability and low-cost production. Here I summarize the critical points in the evaluation of PET hydrolases and discuss the biorecycling of PET.

Changes in the nitrogen status of grey forest coarse dusty light loam soil under different systems of fertilisation and chemical amelioration

This paper presents the results of research in a stationary experiment, launched in 1992 on grey forest coarse-dusty light loamy soil, aimed at studying the influence of long-term chemical amelioration and various fertilisation systems (mineral, organic, organic-mineral) on the nitrogen regime. Nitrogen is extremely important in agriculture, as all growth processes, photosynthesis, metabolism, and yield volume and quality eventually depend on this element. In Ukraine, the share of soils of woodland composition in total soil cover exceeds 33%, while the share of agricultural land is 25%. Since the humus content and its total reserves are an integral measure of soil formation and a key characteristic that determines the overall habitat of the soil, the article analyses changes in humus content as a response to the above factors. It has been found that the gross nitrogen content reflects the humus content, fully depends on and varies with the humus content of the latter. There is a high correlation between these indicators for all variants of the experiment (r = 0.991). The data obtained indicate that only with the use of green manure and by-products of the predecessor and moderate doses of mineral fertilisers in combination with liming, there is a moderate increase in total nitrogen as compared to the initial level. The rise amounted to 0.36 – 0.45 t/ha and in this case, it is possible to observe its extended reproduction. Only after mineralisation does the nitrogen of organic compounds become available to plants. The easily hydrolysed form of nitrogen is a fairly reliable indicator of whether the plants are supplied with this element. According to the classification, the soil under study, with a mobile compound content of 81.2 – 103 mg/kg, falls into the group of soils with a very low degree of nutrient supply, but the degree of hydrolysis of organic matter in it is high (9.6 – 10.2%). With the combined use of green manure, non-commodity crop products, and one-dose mineral fertilisers along with lime, this form of nitrogen increased by 27.5% compared to the control. Under the above fertiliser complex, there was an increase of 16.5 mg/kg in the amount of N-N03-+N-NH4+ compared to the control, plus 7.4 mg/kg of soil nitrification capacity

Mycorrhizal fungi and phosphatase involvement in rhizosphere phosphorus transformations improves plant nutrition during subtropical forest succession

Phosphorus (P) availability is a limiting factor for plant growth in tropical and subtropical regions, but many tropical and subtropical forests maintain high levels of productivity and biodiversity under P-limited conditions, which is why P limitation and plant community biomass increase simultaneously during succession in subtropical forests. Biologically-mediated P transformations in the rhizosphere are expected to increase P acquisition by plants during forest succession in tropical and subtropical regions. In this study, we collected leaf and rhizosphere samples from the dominant tree species in three successional forests (early, middle, and late) at the Dinghushan Biosphere Reserve, Southern China, and measured the leaf P concentrations and biological properties of the rhizosphere: microbial biomass P (MBP), P fractions, acid phosphatase activity, and the biomasses of arbuscular mycorrhizal fungi (AMF) and ectomycorrhizal fungi (EMF). We found that the leaf N:P ratio increased but the rhizosphere microbial biomass N:P ratio decreased from the early- to late-successional stages, indicating more plant P limitation and less microbial P limitation during forest succession. The decreased proportion of occluded P in the rhizosphere was negatively related to the increasing AMF biomass, and the increased proportions of labile organic P (Po) and moderately labile Po were positively associated with increasing AMF biomass but negatively related to the acid phosphatase activity that increased during forest succession. We propose a mechanism for P availability in subtropical successional forests based on AMF processes that increase the transformation of occluded P to labile and moderately labile Po forms, followed by acid phosphatase activity that converts these hydrolysable Po forms into inorganic P. Transformation of occluded P and Po fractions in the rhizosphere to plant-available P will satisfy the increasing P demand of plants during forest succession, thus maintaining the high productivity and biodiversity of P-limited tropical and subtropical forests.

Comparative behaviour of electrospun nanofibers fabricated from acid and alkaline hydrolysed gelatin: towards corneal tissue engineering

Gelatin is a hydrolysed form of collagen which is categorised as type A (acid hydrolysed) or type B (base hydrolysed), based on method of hydrolysis. In this work, we have studied the comparative properties of electrospun nanofibers of gelatin A (GA) and gelatin B (GB) prepared using a ternary solvent (glacial acetic acid/ethyl acetate/water). In addition, silk fibroin was used to improve the integrity and stability of gelatin nanofibrous sheets. Silk fibroin is known to serve as a potential implantable biomaterial because of its optimal mechanical stability, transparency, cell proliferation and tunable degradability. GA scaffold and silk permeated gelatin A nanofibrous scaffold (SFG) showed 50-70% of transparency comparable to that of adult rat and goat cornea. ATR-FTIR analysis showed the presence of native functional groups and bonds. Scanning electron microscope (SEM) micrographs revealed the porous nature of the scaffolds i.e., 48.08± 3.35 and 51.38 ± 3.72 for GA and GB, respectively. GB nanofibrous scaffolds got dissolved instantly in phosphate buffer solution (PBS), while GA scaffolds remained stable up to ∼ 11 h at 25˚C, however got degraded within 12 h when incubated at 37˚C. Furthermore, SFG scaffolds physically cross-linked with ethanol vapour displayed relatively improved stability when examined for at least 6 days at 37°C, minor weight loss when incubated in a lysozyme solution and facilitated the cellular proliferation significantly. Liquid retention capacity of the electrospun GA nanofibrous scaffolds was found to be nearly 800% from its original weight within 48 h. The electrospun nanofibrous scaffolds i.e., SFG facilitated ~72% of cellular proliferation compared to the control for SIRC [Statens Seruminstitut Rabbit Cornea] fibroblasts cells by 5th day of cell culture. Comparative outcomes reveal that the electrospun GA nanofibers possess significantly better integrity and noted stability in an aqueous environment compared to GB nanofibrous scaffold. Moreover, owing to the enhanced integrity and better stability the GA nanofibrous scaffold in combination with silk fibroin could be exploited in corneal tissue engineering applications where transparency plays an indispensable characteristic.

New insight into microbial degradation of mycotoxins during anaerobic digestion

Anaerobic digestion represents an interesting approach to produce biogas from organic waste materials contaminated by mycotoxins. In this study a shotgun metagenomic analysis of lab-scale bioreactors fed with mycotoxin-contaminated silage has been carried out to characterize the evolution of microbial community under the operating conditions and the key enzymatic activities responsible for mycotoxin degradation. The study was conducted at two different level of contamination for fumonisins and aflatoxin B1. After 15 days biogas production was not influenced by the presence of mycotoxins. Metagenomic analysis revealed that a high contamination rate of mycotoxins interfere with microbial diversity. Degradation of mycotoxins accounted in about 54% for aflatoxin B1 and 60% for fumonisins. The degradation activity of fumonisins resulted in the presence of partially hydrolyzed forms in both tested contamination levels. Accordingly, metagenomic functional analysis revealed the presence of two new carboxylesterase genes belonging to D. bacterium and P. bacterium putatively involved in fumonisin degradation.

The hydrolysis of saponin-rich extracts from fenugreek and quinoa improves their pancreatic lipase inhibitory activity and hypocholesterolemic effect

Saponins are promising compounds for ameliorating hyperlipidemia but scarce information exists about sapogenins, the hydrolyzed forms of saponins. Saponin-rich extracts and their hydrolysates from fenugreek (FE, HFE) and quinoa (QE, HQE), and saponin and sapogenin standards, were assessed on the inhibition of pancreatic lipase and interference on the bioaccessibility of cholesterol by in vitro digestion models.All extracts inhibited pancreatic lipase (IC50 between 1.15 and 0.59 mg/mL), although the hydrolysis enhanced the bioactivity of HQE (p = 0.014). The IC50 value significantly correlated to the saponin content (r = −0.82; p = 0.001). Only the hydrolyzed extracts showed a reduction of bioaccessible cholesterol (p < 0.001) higher than that of phytosterols (35% reduction). Sapogenin standards exhibited no bioactivities, protodioscin and hederacoside C slightly inhibited the lipase (around 10%) and protodioscin reduced the bioaccessible cholesterol (23% reduction, p = 0.035).The hydrolysis process of saponin-rich extracts enhances the bioactivity and allows developing multibioactive products against pancreatic lipase and cholesterol absorption simultaneously.

Fibrinogenolytic activity of protease from the culture fluid of &lt;em&gt;Pleurotus ostreatus&lt;/em&gt;

The use of proteases makes it possible to obtain partially hydrolyzed forms of macromolecules with unique properties. The importance of proteases for studying the structure and functions of fibrinogen forces scientists to search for new sources of highly specific proteases. Thus, the aim of this work was to study the content of the Pleurotus ostreatus culture fluid in search of fibrinogen- specific proteases. P. ostreatus was cultured for 14 days at 27°C. The culture fluid was collected and the protein fraction was salted out with NaCl and then dialyzed. Fibrinogen hydrolysis products by P. ostreatus protease were characterized using SDS PAGE under reducing conditions followed by immunoprobing using murine monoclonal antibodies I-5A (anti-Aα505-610) and 2d2a (anti-Bβ26-42). The study of turbidity and platelet aggregation was performed using a Multiskan FC spectrophotometric microplate reader and a SOLAR-2110 aggregometer, respectively. Electron microscopy of fibrils formed by truncated compared with native fibrins was performed using a transmission electron microscope N-600.&#x0D; Analysis of the products of fibrinogen hydrolysis with a fungal protease using SDS-PAGE demonstrated the cleavage of the alpha chain of fibrinogen exclusively with the formation of a truncated form of fibrinogen in which there are no C-terminal portions of αC regions with a molecular weight of 25 kDa. A study of turbidity showed that the polymerization of truncated fibrin is significantly impaired. The rate of lateral association of protofibrils significantly decreased from 1.5 to 2.2 times in the case of truncated fibrinogen compared to the native one depending on the initial concentration of fibrinogen. It was shown that platelet aggregation in the presence of fibrinogen without 25 kDa fragments of αC regions was less effective than in the presence of native fibrinogen. Application of the preparation of the fungal protease allows us to obtain high molecular forms of the fibrinogen molecule with cleaved 25 kDa peptides, which provide new information on the role of these peptides in the fibrinogen functioning.