Catabolism of 2-keto-3-deoxy-galactonate and the production of its enantiomers.

2-Keto-3-deoxy-galactonate (KDGal) serves as a pivotal metabolic intermediate within both the fungal D-galacturonate pathway, which is integral to pectin catabolism, and the bacterial DeLey-Doudoroff pathway for D-galactose catabolism. The presence of KDGal enantiomers, L-KDGal and D-KDGal, varies across these pathways. Fungal pathways generate L-KDGal through the reduction and dehydration of D-galacturonate, whereas bacterial pathways produce D-KDGal through the oxidation and dehydration of D-galactose. Two distinct catabolic routes further metabolize KDGal: a nonphosphorolytic pathway that employs aldolase and a phosphorolytic pathway involving kinase and aldolase. Recent findings have revealed that L-KDGal, identified in the bacterial catabolism of 3,6-anhydro-L-galactose, a major component of red seaweeds, is also catabolized by Escherichia coli, which is traditionally known to be catabolized by specific fungal species, such as Trichoderma reesei. Furthermore, the potential industrial applications of KDGal and its derivatives, such as pyruvate and D- and L-glyceraldehyde, are underscored by their significant biological functions. This review comprehensively outlines the catabolism of L-KDGal and D-KDGal across different biological systems, highlights stereospecific methods for discriminating between enantiomers, and explores industrial application prospects for producing KDGal enantiomers. KEY POINTS: • KDGal is a metabolic intermediate in fungal and bacterial pathways • Stereospecific enzymes can be used to identify the enantiomeric nature of KDGal • KDGal can be used to induce pectin catabolism or produce functional materials.

Is there still a place for serum galactomannan in the diagnosis of invasive aspergillosis in children at high risk and under antifungal prophylaxis?

BACKGROUND: The performance of serum galactomannan (GM) for the diagnosis of invasive aspergillosis (IA) has been studied mainly in adults. Paediatric data are scarce and based on small and heterogeneous cohorts. OBJECTIVE: To evaluate the performance of serum GM for the diagnosis of IA in a paediatric oncologic population at high risk of IA and to clarify the impact of antifungal prophylaxis on this test. METHODS: We performed a retrospective study from January 2014 to December 2020 in the paediatric oncologic haematologic department of the University Hospital of Bordeaux. The diagnosis of IA was made using the recommendations of the EORTC and the MSGERC. RESULTS: Among the 329 periods at high risk of IA in 222 patients, the prevalence of IA was 1.8% (3 proven and 3 probable IA). In the total population, the sensitivity, and the positive predictive value (PPV) were respectively 50% and 17.6%. Under antifungal prophylaxis, the sensitivity and PPV dropped, respectively, to 33.3% and 14.3%. In this group, the post-test probability of IA was 2% for a negative serum GM and only 14%. CONCLUSION: In this large cohort of children at high risk of IA, the incidence of IA is low and the diagnostic performance of GM is poor, especially in the case of mould-active prophylaxis. Screening should be targeted rather than systematic and should be reserved for patients at highest risk for IA without mould-active prophylaxis. Combination with other tests such as Aspergillus PCR would increase the accuracy of GM in screening setting.

Biomarker Driven Antifungal Stewardship (BioDriveAFS) in acute leukaemia-a multi-centre randomised controlled trial to assess clinical and cost effectiveness: a study protocol for a randomised controlled trial.

BACKGROUND: Acute leukaemias (AL) are life-threatening blood cancers that can be potentially cured with treatment involving myelosuppressive, multiagent, intensive chemotherapy (IC). However, such treatment is associated with a risk of serious infection, in particular invasive fungal infection (IFI) associated with prolonged neutropenia. Current practice guidelines recommend primary antifungal (AF) prophylaxis to be administered to high-risk patients to reduce IFI incidence. AFs are also used empirically to manage prolonged neutropenic fever. Current strategies lead to substantial overuse of AFs. Galactomannan (GM) and ß-D-glucan (BG) biomarkers are also used to diagnose IFI. Combining both biomarkers may enhance the predictability of IFI compared to administering each test alone. Currently, no large-scale randomised controlled trial (RCT) has directly compared a biomarker-based diagnostic screening strategy without AF prophylaxis to AF prophylaxis (without systematic biomarker testing). METHODS: BioDriveAFS is a multicentre, parallel, two-arm RCT of 404 participants from UK NHS Haematology departments. Participants will be allocated on a 1:1 basis to receive either a biomarker-based antifungal stewardship (AFS) strategy, or a prophylactic AF strategy, which includes existing standard of care (SoC). The co-primary outcomes will be AF exposure in the 12-month post randomisation and the patient-reported EQ-5D-5L measured at 12-month post randomisation. Secondary outcomes will include total AF exposure, probable/proven IFI, survival (all-cause mortality and IFI mortality), IFI treatment outcome, AF-associated adverse effects/events/complications, resource use, episodes of neutropenic fever requiring hospital admission or outpatient management, AF resistance in fungi (non-invasive and invasive) and a Desirability of Outcome Ranking. The trial will have an internal pilot phase during the first 9 months. A mixed methods process evaluation will be integrated in parallel to the internal pilot phase and full trial, aiming to robustly assess how the intervention is delivered. Cost-effectiveness analysis will also be performed. DISCUSSION: The BioDriveAFS trial aims to further the knowledge of strategies that will safely optimise AF use through comparison of the clinical and cost-effectiveness of a biomarker-led diagnostic strategy versus prophylactic AF to prevent and manage IFI within acute leukaemia. The evidence generated from the study will help inform global clinical practice and approaches within antifungal stewardship. TRIAL REGISTRATION: ISRCTN11633399. Registered 24/06/2022.

Performance of the clarus Aspergillus galactomannan enzyme immunoassay prototype for the diagnosis of invasive pulmonary aspergillosis in serum.

BACKGROUND: Serum galactomannan (GM) testing is essential for diagnosing invasive aspergillosis (IA), particularly in immunocompromised individuals. The global lack of on-site GM testing capacities necessitates cost-effective alternatives, such as .the clarus Aspergillus GM enzyme immunoassay prototype (clarus AGM prototype). METHODS: This single-centre, cross-sectional study compared the diagnostic performance of the clarus AGM prototype (IMMY, Norman, Oklahoma) with the serological gold standard (=Platelia AGM assay; Bio-Rad, Marnes-la-Cocquette, France). IA was classified according to modified 2020 EORTC/MSG consensus and 2024 FUNDICU criteria. In total, 300 prospectively (May-Dec 2023) and retrospectively (2012-2015) collected samples were included. RESULTS: Among 300 samples from 232 patients, 49 (16%) were classified as proven (n = 1) or probable IA (n = 48). In non-IA cases (n = 250), one patient was classified as possible IA. With the manufacturer recommended cut-off of ≥0.2, sensitivity and specificity of the clarus AGM prototype were 27% (13/49; 95% confidence interval [CI]: 15%-41%) and 99% (248/250; 95% CI: 97%-100%), respectively, while sensitivity and specificity were 78% and 79% when using the optimised Youden's cut-off of 0.0045 ODI. ROC curve analysis demonstrated an area under the curve (AUC) of 0.829 (95% CI: 0.760-0.898) for the clarus AGM prototype in distinguishing between proven/probable IA and non-IA. The AUC for the Platelia AGM was 0.951 (95% CI: 0.909-994). Spearman's correlation analysis showed a weak correlation between the two assays (0.382; p < .001). CONCLUSIONS: The weak correlation between the clarus AGM prototype and Platelia AGM highlights the need for further investigation into the clinical performance of the clarus AGM prototype, giving the different antigen epitopes addressed.

Madhuca indica oil-entrapped buoyant galactomannan hydrogel microspheres for controlling epileptic seizures.

A stable Madhuca indica oil-in-water nanoemulsion (99-210 nm, zeta potential: > - 30 mV) was produced employing Tween 20 (surfactant) and Transcutol P (co-surfactant) (3:1). The nanoemulsion (oil: Smix = 3:7, 5:5, and 7:3) were subsequently incorporated into oxcarbazepine-loaded carboxymethylxanthan gum (DS = 1.23) dispersion. The hydrogel microspheres were formed using the ionic gelation process. Higher oil concentration had a considerable impact on particle size, drug entrapment efficiency, and buoyancy. The maximum 92 % drug entrapment efficiency was achieved with the microspheres having oil: Smix ratio 5:5. FESEM study revealed that the microspheres were spherical in shape and had an orange peel-like surface roughness. FTIR analysis revealed a hydrogen bonding interaction between drug and polymer. Thermal and x-ray examinations revealed the transformation of crystalline oxcarbazepine into an amorphous form. The microspheres had a buoyancy period of 7.5 h with corresponding release of around 83 % drug in 8 h in simulated stomach fluid, governed by supercase-II transport mechanism. In vivo neurobehavioral studies on PTZ-induced rats demonstrated that the microspheres outperformed drug suspension in terms of rotarod retention, number of crossings, and rearing activity in open field. Thus, Madhuca indica oil-in-water nanoemulsion-entrapped carboxymethyl xanthan gum microspheres appeared to be useful for monitoring oxcarbazepine release and managing epileptic seizures.

The study of galactomannans with different molecular weights and their ability to form microparticles suitable for pulmonary delivery.

The influence of locust bean gum (LBG) galactomannans (GMs) molecular weight (Mw) to assemble microparticulate systems was evaluated, and carriers for deep lung delivery were developed. A commercial batch of LBG with a mannose/galactose (M/G) ratio of 2.4 (batch 1) was used to study the influence of different microwave partial acid hydrolysis conditions on carbohydrate composition, glycosidic linkages, and aqueous solutions viscosity. The microwave treatment did not affect the composition, presenting 4-Man (36-42 %), 4,6-Man (27-35 %), and T-Gal (24-25 %) as the main glycosidic linkages. Depolymerization led to a viscosity reduction (≤0.005 Pa·s) with no major impact on polysaccharide debranching. The structural composition of the LBG galactomannans were further elucidated with sequence-specific proteins using carbohydrate microarray technologies. A second batch of LBG (M/G 3.3) was used to study the impact of GMs with different Mw on microparticle assembling, characteristics, and insulin release kinetics. The low-Mw GMs microparticles led to a faster release (20 min) than the higher-Mw (40 min) ones, impacting the release kinetics. All microparticles exhibited a safety profile to cells of the respiratory tract. However, only the higher-Mw GMs allowed the assembly of microparticles with sizes suitable for this type of administration.

Galf-Specific Neolectins: Towards Promising Diagnostic Tools.

In the absence of naturally available galactofuranose-specific lectin, we report herein the bioengineering of GalfNeoLect, from the first cloned wild-type galactofuranosidase (Streptomyces sp. strain JHA19), which recognises and binds a single monosaccharide that is only related to nonmammalian species, usually pathogenic microorganisms. We kinetically characterised the GalfNeoLect to confirm attenuation of hydrolytic activity and used competitive inhibition assay, with close structural analogues of Galf, to show that it conserved interaction with its original substrate. We synthetised the bovine serum albumin-based neoglycoprotein (GalfNGP), carrying the multivalent Galf units, as a suitable ligand and high-avidity system for the recognition of GalfNeoLect which we successfully tested directly with the galactomannan spores of Aspergillus brasiliensis (ATCC 16404). Altogether, our results indicate that GalfNeoLect has the necessary versatility and plasticity to be used in both research and diagnostic lectin-based applications.

Comprehensive rheological analysis of structurally related acetan-like heteroexopolysaccharides from two Kozakia baliensis strains in surfactants and galactomannan blends.

Natural biopolymers become increasingly attractive as bio-based alternatives to petrol-based rheological modifiers, especially in personal care applications. However, many polysaccharides exhibit undesired properties in cosmetic applications such as limited viscosifying characteristics, unpleasant sensory properties, or incompatibility with certain formulation compounds. Here, a comprehensive rheological analysis of non-decorated acetan-like heteroexopolysaccharides derived from two Kozakia baliensis strains was performed in selected surfactant formulations. The results were compared to native xanthan gum and a genetically engineered xanthan variant, Xan∆gumFGL, which lacks any acetyl- and pyruvyl moieties and whose rheological properties are unaffected by saline environments. All four polysaccharides displayed a highly similar rheological performance in the non-ionic surfactant lauryl glucoside, while the rheological properties differed in amphoteric and anionic surfactants cocamidopropyl betaine and sodium laureth sulfate due to minor changes in side chain composition. Polysaccharide precipitation was observed in the presence of the cationic surfactant. Nevertheless, the native heteroexopolysaccharide derived from K. baliensis LMG 27018 shows significant potential as a salt-independent rheological modifier compared to the genetically engineered Xan∆gumFGL variant. In addition, blends of heteroexopolysaccharides from K. baliensis and several galactomannans displayed synergistic effects which were comparable to native xanthan gum-galactomannan blends. This study shows that heteroexopolysaccharides of K. baliensis are capable of further extending the portfolio of bio-based rheological modifiers.

Comprehensive characterization of hemicelluloses obtained from Gleditsia sinensis Lam. pods and the application of moderately degraded hemicelluloses in galactomannan film.

The Gleditsia sinensis Lam. pods (GSP) are consistently discarded as waste after saponin extraction due to a lack of industrial or high-value utilization. Herein, the hemicelluloses were extracted from two varieties of GSP and subjected to comprehensive characterization. The molar mass of DMSO-soluble hemicelluloses (53.3-66.0 kDa) was higher compared to that of alkali-soluble ones (24.9-32.6 kDa). The presence of minimal acetyl substitution (3.85-4.49 %) on xylan was unequivocally confirmed. NMR spectroscopic analysis indicated that the hemicelluloses in GSP predominantly consist of a 1,4-ß-ᴅ-Xyl backbone with arabinose substituents at O-3 and 4-O-methyl-α-ᴅ-GlcA substituents at O-2 of the xylose residues. p-Coumaric acid substitution also occurred on the 1,4-ß-ᴅ-Xyl backbone. Hydrothermal treatment significantly reduced the hemicelluloses' relative molar mass and produced 7-10 % xylo-oligosaccharides. Furthermore, the moderately degraded hemicelluloses exhibited significantly enhanced biological activity. Finally, the incorporation of the moderately degraded hemicelluloses imparted the galactomannan film with exceptional antioxidant properties (81.1 % DPPH scavenging activity), while negligibly affecting its transparency. Our study's findings will contribute to a comprehensive understanding of the structural and biochemical properties of hemicellulose in waste G. sinensis pods, thereby facilitating their enhanced utilization in industrial applications.

Hydrogels based on galactomannan and κ-carrageenan containing immobilized biomolecules for in vivo thermal-burn wound treatment.

Hydrogels based on natural polysaccharides have demonstrated efficacy in epithelial recovery from cutaneous burn wounds. Here, we prepared a double-network hydrogel consisting of galactomannan (from Cassia grandis seeds) and κ-carrageenan (commercially sourced), cross-linked with CaCl2, as a matrix for immobilizing lactoferrin and/or Cramoll, aiming at its applicability as dressings for second-degree burn wounds. The formulations obtained [H - hydrogel, HL - hydrogel + lactoferrin, HC - hydrogel + Cramoll and HLC - hydrogel + lactoferrin + Cramoll] were analyzed rheologically as well as in terms of their stability (pH, color, microbial contamination) for 90 days. The burn was created with an aluminum bar (97 ± 3 °C) in the dorsal region of Wistar rats and subsequently treated with hydrogels (H, HL, HC, HLC) and control saline solution (S). The burn was monitored for 3, 7 and 14 days to evaluate the efficacy of the hydrogels in promoting wound healing. The hydrogels did not reveal significant pH or microbiological changes; there was an increase in brightness and a reduction in opacity for H. The rheological analysis confirmed the gel-like viscoelastic signature of the systems without substantial modification of the basic rheological characteristics, however HLC proved to be more rigid, due to rheological synergy when combining protein biomolecules. Macroscopic analyses confirmed centripetal healing with wound contraction: S < H < HC < HL < HLC. Histopathological analyses showed that hydrogel-treated groups reduced inflammation, tissue necrosis and fibrosis, while promoting re-epithelialization with focal acanthosis, especially in HLC due to a positive synergistic effect, indicating its potential as a promising therapy in the repair of burns.

Comparison of different lateral flow assays on bronchoalveolar lavage fluid for invasive aspergillosis screening in non-hematological patients.

Several lateral flow assays (LFA) capable of detecting Aspergillus fumigatus in serum and broncho-alveolar lavage fluid (BALF) within the hour, thereby potentially accelerating the screening process, are now commercially available. We prospectively compared three LFA targeting A. fumigatus on BALF collected from non-surgical intensive care patients between June 2022 and February 2023. The three LFA tested were Sõna Aspergillus galactomannan LFA (Immy), Fungadia Aspergillus antigen (Gadia), and AspLFD (OLM Diagnostics). We compared the results of these LFA with those of the galactomannan (GM) Platelia Aspergillus enzyme immunoassay (Bio-Rad), culture on Sabouraud medium and Aspergillus qPCR. We tested 97 BALF samples from 92 patients. In total 84 BALF samples tested negative with all three LFA, and four BALF samples tested positive with the AspLFD assay only (OLM). Only one BALF sample tested positive with the three LFA. In addition, three BALF samples tested positive only with the GM Platelia immunoassay. Four diagnosis of probable invasive aspergillosis were retained for the 92 patients tested. This prospective series included very few positive samples. From a practical point of view, the LFA from OLM presented the simplest protocol for use.

Evaluation of the JF5-based Aspergillus galactomannoprotein lateral flow device for diagnosing invasive aspergillosis in cancer patients.

PURPOSE: Cancer patients are at heightened risk for invasive aspergillosis (IA), a condition associated with elevated mortality risk. The JF5-based Aspergillus Galactomannoprotein Lateral Flow Device (AspLFD) offers rapid point-of-care testing (POCT) for IA. This study evaluated the diagnostic performance of AspLFD in cancer populations. METHODS: This retrospective study examined cancer patient bronchoalveolar lavage fluid (BALF) and serum samples collected between September 2021 and January 2023. Both AspLFD and galactomannan (GM) assays were conducted, and the results were analysed by two independent researchers. RESULTS: This study included 242 samples from 218 cancer patients, with 58 BALF and 184 serum samples. The overall agreement between AspLFD and GM assay results was 92.1%, with a kappa value of 0.552. AspLFD diagnosed proven/probable IA with a sensitivity and specificity of 91.7% and 95.3%, respectively, whereas GM exhibited sensitivity and specificity values of 83.3% and 93.7%, respectively. There were no statistical differences in the sensitivity and specificity between the two methods (P > 0.05). For serum analyses, AspLFD and GM exhibited similar sensitivity (66.7% vs. 66.7%, P > 0.05) and specificity (98.6% vs. 96.6%, P > 0.05) values. However, the sensitivity of the AspLFD was superior to the GM assay (100% vs. 88.9%) in BALF analyses but the difference was not statistically significant (P > 0.05), with no difference in specificity (83.7% vs. 83.7%, P > 0.05). In the solid-tumour cohort, both the AspLFD and GM assay exhibited high sensitivity (100% for both) and specificity (94.2% vs. 92.8%, P > 0.05). CONCLUSION: The AspLFD demonstrated good performance in diagnosing IA in cancer patients, especially those with solid tumours. The AspLFD is thus an alternative POCT, particularly when GM evaluations are not readily available.

Performance of the galactomannan test for the diagnosis of invasive pulmonary aspergillosis using non-invasive proximal airway samples.

OBJECTIVE: To diagnose invasive pulmonary aspergillosis (IPA), galactomannan (GM) detection in serum or bronchoalveolar lavage fluid (BALF) is widely used. However, the utility of proximal airway GM test (from induced sputum or tracheal aspirate) has not been well elucidated. METHODS: In this retrospective cohort study, we evaluated the diagnostic performance of proximal airway GM in diagnosis of IPA including COVID-19 associated pulmonary aspergillosis (CAPA). Between January 2022 and January 2023, patients who had been tested for GM with clinical suspicion or for surveillance from any specimen (serum, induced sputum, tracheal aspirate, and BALF) were screened. IPA was diagnosed using EORTC/MSGERC criteria, and CAPA was diagnosed following the 2020 ECMM/ISHAM consensus criteria. RESULTS: Of 624 patients with GM results, 70 met the criteria for proven/probable IPA and 427 had no IPA. The others included possible IPA and chronic form of aspergillosis. The sensitivities and specificities of serum, proximal airway, and BALF GM for proven/probable IPA versus no IPA were 78.9% and 70.6%, 93.1% and 78.7%, and 78.6% and 91.0%, respectively. Areas under the receiver operating characteristic curve (AUCs) were 0.742 for serum GM, 0.935 for proximal airway GM, and 0.849 for BALF GM (serum GM vs proximal airway GM, p = 0.014; proximal airway GM vs BALF GM, p = 0.334; serum GM vs BALF GM, p = 0.286). CONCLUSION: This study demonstrates that the performance of GM test from non-invasive proximal airway samples is comparable or even better than those from serum and distal airway sample (BALF).

Discovery of α-(1→6)-linked mannan structures resembling yeast N-glycan outer chains in Aspergillus fumigatus mycelium.

The cellular surface of the pathogenic filamentous fungus Aspergillus fumigatus is enveloped in a mannose layer, featuring well-established fungal-type galactomannan and O-mannose-type galactomannan. This study reports the discovery of cell wall component in A. fumigatus mycelium, which resembles N-glycan outer chains found in yeast. The glycosyltransferases involved in its biosynthesis in A. fumigatus were identified, with a focus on two key α-(1→2)-mannosyltransferases, Mnn2 and Mnn5, and two α-(1→6)-mannosyltransferases, Mnn9 and Van1. In vitro examination revealed the roles of recombinant Mnn2 and Mnn5 in transferring α-(1→2)-mannosyl residues. Proton nuclear magnetic resonance (1H-NMR) analysis of cell wall extracts from the ∆mnn2∆mnn5 strain indicated the existence of an α-(1→6)-linked mannan backbone in the A. fumigatus mycelium, with Mnn2 and Mnn5 adding α-(1→2)-mannosyl residues to this backbone. The α-(1→6)-linked mannan backbone was absent in strains where mnn9 or van1 was disrupted in the parental ∆mnn2∆mnn5 strain in A. fumigatus. Mnn9 and Van1 functioned as α-(1→6)-linked mannan polymerases in heterodimers when co-expressed in Escherichia coli, indicating their crucial role in biosynthesizing the α-(1→6)-linked mannan backbone. Disruptions of these mannosyltransferases did not affect fungal-type galactomannan biosynthesis. This study provides insights into the complexity of fungal cell wall architecture and a better understanding of mannan biosynthesis in A. fumigatus. IMPORTANCE: This study unravels the complexities of mannan biosynthesis in A. fumigatus, a key area for antifungal drug discovery. It reveals the presence of α-(1→6)-linked mannan structures resembling yeast N-glycan outer chains in A. fumigatus mycelium, offering fresh insights into the fungal cell wall's design. Key enzymes, Mnn2, Mnn5, Mnn9, and Van1, are instrumental in this process, with Mnn2 and Mnn5 adding specific mannose residues and Mnn9 and Van1 assembling the α-(1→6)-linked mannan structures. Although fungal-type galactomannan's presence in the cell wall is known, the existence of an α-(1→6)-linked mannan adds a new dimension to our understanding. This intricate web of mannan biosynthesis opens avenues for further exploration and enhances our understanding of fungal cell wall dynamics, paving the way for targeted drug development.

Is there an interest in systematic serum screening for aspergillosis in COVID-19 patients in a medical ward?

PURPOSE: We evaluated the interest of systematic screening of serum fungal markers in patients hospitalized in a medical ward. METHODS: We retrospectively analyzed all patients hospitalized in our infectious disease department from October 1st to October 31st, 2020 for COVID-19 without prior ICU admission, and for whom systematic screening of serum fungal markers was performed. RESULTS: Thirty patients were included. The majority of patients received corticosteroids (96.7%). The galactomannan antigen assay was positive for 1/30 patients at D0, and 0/24, 0/16, 0/13 and 0/2 at D4, D7, D10 and D14 respectively. 1,3-ß-D-glucan was positive for 0/30, 1/24, 1/12, 0/12, 0/2 at D0, D4, D7, D10 and D14 respectively. No Aspergillus fumigatus PCR was positive. No cases of aspergillosis were retained. CONCLUSION: Our study does not support the interest of systematic screening of fungal markers in immunocompetent patients with COVID-19 in a conventional unit.

High efficient preparation of low molecular weight galactomannan from Leucaena leucocephala galactomannan through the combination of hydrogen peroxide and oxalic acid.

Researchers have always been interested in polysaccharide degradation because of the increased biological activity and usability following degradation. In this work, low molecular weight galactomannan (LMW-GM) was produced through the degradation of galactomannan by H2O2 and oxalic acid (OA). The optimal reaction conditions were found by conducting the response surface optimization experiment based on single-factor experiment and kinetics analysis. Under these conditions, the LMW-GM yield was 69.48 ± 1.02 %. Ultimately, an analysis of the degradation process revealed that OA attacked GM indiscriminately, and H2O2 has a stronger effect on the removal of branched chains while degrading GM. Hence, the degradation steps were rearranged as H2O2 was added 20 min before OA at a constant total time. The LMW-GM yield was successfully increased to 76.49 ± 1.27 %. The goal of this work is hopefully to give a theoretical foundation for the low-cost preparation and industrial production of the degradation of galactomannan.

Utility of galactomannan diagnostic assay in rhino-orbito-cerebral mycosis in COVID-19 patients.

An increasing number of fungal infections were reported post COVID-19 and many of them were caused by fungi of mixed aetiologies. This study was carried out to assess the utility of serum galactomannan (GM) assay in establishing the etiology of acute rhino-orbito-cerebral mycosis caused by Aspergillus spp. Two serum samples were obtained from 41 suspected post COVID-19 rhino-orbito-cerebral mycosis patients to perform GM assay. Serum GM assay was positive in 68.7% of the cases of proven aspergillosis at cut off OD = 1.0. Serum GM assay can be used as a supplementary test in the diagnosis of rhino-orbito-cerebral mycosis caused by Aspergillus spp.

Isolation, structural, biological activity and application of Gleditsia species seeds galactomannans.

Gleditsia fruits have been known as a valuable traditional Chinese herb for tens of centuries. Previous studies showed that the galactomannans are considered as one of the major bioactive components in Gleditsia fruits seeds (GSGs). Here, we systematically review the major studies of GSGs in recent years to promote their better understanding. The extraction methods of GSGs mainly include hot water extraction, microwave-assisted extraction, ultrasonic extraction, acid extraction, and alkali extraction. The analysis revealed that GGSs exhibited in the form of semi-flexible coils, and its molecular weight ranged from 0.018 × 103 to 2.778 × 103 KDa. GSGs are composed of various monosaccharide constituents such as mannose, galactose, glucose, and arabinose. In terms of pharmacological effects, GSGs exhibit excellent activity in antioxidation, hypoglycemic, hypolipidemic, anti-inflammation. Moreover, GSGs have excellent bioavailability, biocompatibility, and biodegradability, which make them used in food additives, food packaging, pharmaceutical field, industry and agriculture. Of cause, the shortcomings of the current research and the potential development and future research are also highlighted. We believe our work provides comprehensive knowledge and underpinnings for further research and development of GSGs.

Application of the galactomannan gel from Cassia grandis seeds for biomedical purposes: Study of the incorporation of collagenases and their release profile.

The galactomannan-based gel from Cassia grandis seeds was used to incorporate Penicillium sp. UCP 1286 and commercial collagenases. Experiments were carried out according to a 23-full factorial design to identify the most significant parameters for the incorporation process. The pH of the incorporation solution (pHi), stirring time (t), and initial protein concentration in the crude extract (PCi) were selected as the three independent variables, and the efficiency of collagenase incorporation (E) and collagenolytic activity (CA) after 360 min as the responses. pHi and PCi showed positive statistically significant effects on E, while CA was positively influenced by pHi and t, but negatively by PCi. The fungi collagenase was released from the gel following a pseudo-Fickian behavior. Additionally, no <76 % of collagenase was efficiently incorporated into the gel retaining a high CA (32.5-69.8 U/mL). The obtained results for the commercial collagenase (E = 93.88 %, CA = 65.8 U/mL, and n = 0.10) demonstrated a pseudo-Fickian behavior similar to the fungi-collagenase. The results confirm the biotechnological potential of the gel as an efficient matrix for the incorporation of catalytic compounds; additionally, the incorporation of collagenases was achieved by retaining the proteases CA and releasing them in a controlled manner.