Disaster process-based spatiotemporal characteristics of apricot frost in the warm temperate zone (WTZ), China.

Frost stress is a major environmental factor that limits apricot growth in the warm temperate zone (WTZ) of China, and is always triggered by extreme low temperature weather processes. In this study, the characteristics of the apricot frost processes f(D, Tcum), which were identified from historical disaster representation, were analyzed and apricot frost evaluation indicators were developed, thus facilitating the process-based assessment and spatiotemporal analysis of apricot frost processes. Periods of low temperature that persist for 1~2, 3, and ≥4 days (i.e., duration days, D) provide the initial identification indicator for light, moderate, and severe apricot frost. The threshold ranges for Tcum are 0~3.9, 9.2~12.0, and >16.2 for D values of 1~2, 3, and ≥4, respectively. The northwest of the WTZ is dominated by apricot frost, with approximately 80% of apricot frost being light, followed by moderate and severe. Regional apricot frost exhibited a significant decreasing trend over the last four decades. A total of 29.65% of stations, which were mainly located in the northwest and middle parts of the study region, detected an increasing trend in apricot frost. The results provide technical support for targeted apricot frost level detection, and the process-based spatiotemporal characteristics of apricot frost can provide basic information for the prevention and mitigation of apricot frost.

Effect and environmental behaviour of microplastics in soil.

Soil microplastic pollution is currently a worldwide concern. Microplastics are organic pollutants that are abundant in the natural environment, are persistent and difficult to degrade and may endanger human health while harming the environment. This article offers a bibliometric analysis of the environmental behaviour of microplastics in soils, as well as a thorough statistical analysis of research goals and trends in this field. We conducted a thorough search of all relevant literature from 2012 to 2022 in the Web of Science core database. The data analysis shows that, starting in 2012, there has been an upward trend in the number of articles about soil microplastic pollution. It can also be seen that China is relatively ahead of the curve in this area of research, followed by the United Kingdom and the United States. This article also systematically describes the research hotspots in this field. The results show that the current research on soil microplastics is mainly focused on their identification, enrichment and toxicity, whereas studies on the migration and transformation of soil microplastics and the mechanism of interaction with other pollutants are still lacking. Our results provide ideas and prospects for future research in this field.

Characterization of feruloyl esterases from Pecoramyces sp. F1 and the synergistic effect in biomass degradation.

Feruloyl esterase (FAE; EC 3.1.1.73) cleaves the ester bond between ferulic acid (FA) and sugar, to assist the release of FAs and degradation of plant cell walls. In this study, two FAEs (Fae13961 and Fae16537) from the anaerobic fungus Pecoramyces sp. F1 were heterologously expressed in Pichia pastoris (P. pastoris). Compared with Fae16537, Fae13961 had higher catalytic efficiency. The optimum temperature and pH of both the FAEs were 45 ℃ and 7.0, respectively. They showed good stability-Fae16537 retained up to 80% activity after incubation at 37 ℃ for 24 h. The FAEs activity was enhanced by Ca2+ and reduced by Zn2+, Mn2+, Fe2+ and Fe3+. Additionally, the effect of FAEs on the hydrolytic efficiency of xylanase and cellulase was also determined. The FAE Fae13961 had synergistic effect with xylanase and it promoted the degradation of xylan substrates by xylanase, but it did not affect the degradation of cellulose substrates by cellulase. When Fae13961 was added in a mixture of xylanase and cellulase to degrade complex agricultural biomass, it significantly enhanced the mixture's ability to disintegrate complex substrates. These FAEs could serve as superior auxiliary enzymes for other lignocellulosic enzymes in the process of degradation of agricultural residues for industrial applications.

The enrichment of anaerobic fungi and methanogens showed higher lignocellulose degrading and methane producing ability than that of bacteria and methanogens.

In this study, rumen content was used to obtain three enrichments of anaerobic fungi and methanogens (F + M enrichment), bacteria and methanogens (B + M enrichment), and whole rumen content (WRC enrichment), to evaluate their respective ability to degrade lignocellulose and produce methane. Among the treatments, F + M enrichment elicited the strongest lignocellulose degradation and methane production ability with both rice straw and wheat straw as substrates. Quantitative real-time PCR analysis and diversity analyses of methanogens in the three enrichment treatments demonstrated that F + M had larger number of 16S rRNA gene copies of methanogens and higher relative abundance of Methanobrevibacter, the predominant methanogen found in all enrichments. Caecomyces was the main anaerobic fungal genus for co-culturing to provide substrates for methanogens in this enrichment. Importantly, the F + M enrichment was stable and could be maintained with transfers supplied every 3 days, confirming its potential utility in anaerobic digestion for lignocellulose degradation and methane production.

The effects of threshing and redrying on bacterial communities that inhabit the surface of tobacco leaves.

Before being subjected to the aging process, raw tobacco leaves (TLs) must be threshed and redried. We propose that threshing and redrying affect the bacterial communities that inhabit the TL surface, thereby influencing the aging process. However, these effects remain unclear. In this study, Illumina sequencing was applied to analyze the bacterial communities on both raw and redried TLs. Shannon's diversity value decreased from 3.38 to 2.52 after the threshing and redrying processes, indicating a large reduction in TL bacterial diversity. The bacterial communities also largely differed between raw TLs and redried TLs. On unaged raw TLs, Proteobacteria was the most dominant phylum (56.15%), followed by Firmicutes (38.99%). In contrast, on unaged redried TLs, Firmicutes (76.49%) was the most dominant phylum, followed by Proteobacteria (21.30%). Thus, the dominant genus Proteobacteria, which includes Sphingomonas, Stenotrophomonas, and Pantoea, decreased after the threshing and redrying processes, while the dominant genus Firmicutes, which includes Bacillus and Lactococcus, increased. Changes in the bacterial communities between raw and redried TLs were also noted after 1 year of aging. The relative abundance of dominant Proteobacteria taxa on raw TLs decreased from 56.15 to 16.92%, while the relative abundance of Firmicutes taxa increased from 38.99 to 79.10%. However, small changes were observed on redried TLs after 1 year of aging, with a slight decrease in Proteobacteria (21.30 to 17.64%) and a small increase in Firmicutes (76.49 to 79.10%). Based on these results, Firmicutes taxa may have a higher tolerance for extreme environments (such as high temperature or low moisture) than Proteobacteria bacteria. This study is the first report to examine the effects of threshing and redrying on bacterial communities that inhabit TLs.

[PCDH19 gene mutations lead to epilepsy with mental retardation limited to females in 2 cases and literature review].

Epilepsy with mental retardation limited to females (EFMR) is a syndrome characterized by early onset heat-sensitive epilepsy of infancy or early childhood and generally limited to females, which previously reported that the cadherin gene superfamily subtype protocadherin 19 (PCDH19) gene is its pathogenic gene. We retrospectively analyzed the clinical data for 2 cases of EFMR patients with PCDH19 mutation diagnosed by Department of Pediatric Neurology of Xiangya Hospital, Central South University in 2015. Literature on PubMed, OMIM and HGMD relevant to this syndrome was reviewed, and the clinical characteristics were summarized accordingly. The 2 cases are consistent with the typical clinical manifestations of EFMR caused by PCDH19 mutations. Their seizures are heat sensitive, with or without screaming, and expressed in various forms. Cognitive impairment or autism-like performance were often identified in these patients, hematuria metabolic diseases screening was normal, no abnormal MRI imaging of the head, and de novo PCDH19 gene mutations were found in their epilepsy gene chip sequencing. It is noteworthy that this disease is very similar to the clinical manifestations of the Dravet syndrome due to the mutations of the neurotype sodium channel α1 subunit SCN1A. Therefore, in female patients whose clinical manifestations resemble to Dravet syndrome but SCN1A gene test were negative, EFMR with PCDH19 mutation should be taken into consideration. Early PCDH19 gene testingis of great significance because it not only helps clinicians to understand and analyze the prognosis of this disease, but also offers genetic counseling to the parents.

Production, purification and characterization of an exo-polygalacturonase from Penicillium janthinellum sw09.

A soil isolate, Penicillium janthinellum sw09 has been found to produce significant amounts of an extracellular pectinase subsequently characterized as exo-polygalacturonase (exo-PG). By optimizing growth conditions, P. janthinellum sw09 produced high amount of exo-PG (16.54 units/mL). The crude enzyme was purified by gel filtration chromatography and two exo-PG activity peaks (designated as PGI and PGII) were revealed. On SDS-PAGE analysis, purified PGII using DEAE-Sepharose FF column, was found to be a single band with a molecular mass of 66.2 kDa. The purified PGII exhibited maximal activity at the temperature of 45 oC and pH 5.0. The stability profiles show that PGII is more stable in the pH range of 4.0-8.0 and below 60 oC. The Km and Vmax for the enzyme was 1.74 mg/mL and 18.08 µmol/ (mL•min), respectively. Due to this enzymatic characterization, this pectinase is an attractive candidate for applications in degradation of pectin.

[Clinical features and genome-wide copy number variation analysis in 60 children with early-onset epileptic encephalopathies of unknown cause].

OBJECTIVE: To study the clinical features of early-onset epileptic encephalopathies (EEEs) of unknown cause, and to identify pathogenic microdeletion/microduplication of EEEs by genome-wide analysis of copy number variations (CNVs). METHODS: The clinical data of 60 children diagnosed with unexplained EEEs between July 2012 and April 2013 were obtained and analyzed. Specimens were collected from the selected children and their parents. Single nucleotide polymorphism array was used to detect genome-wide CNVs, and fluorescence in situ hybridization was performed to verify the results and analyze the source of the parents, further to identify suspected pathogenic CNVs of EEEs. RESULTS: Among the 60 children with unexplained EEEs, 34 were diagnosed with West syndrome, 3 with Ohtahara syndrome, 3 with Dravet syndrome, and 20 with unclassified EEEs. In total, 77% of the patients were associated with moderate to severe mental retardation. Head imaging test implied that 35% of the patients had brain dysplasia or astrophy. Among 54 patients, 17% showed microcephalus. After treatment, 28 patients had clinical seizures under control, 16 out of control, 5 dead, and 1 lost to follow-up. Genome-wide analysis of CNVs showed that 7 pathogenic or suspected pathogenic CNVs were present in 5 patients. CONCLUSIONS: EEEs of unknown cause are associated with high phenotypic heterogeneity and poor prognosis. Genome-wide CNVs analysis can demonstrate pathogenic or suspected pathogenic CNVs. This research expands the gene bank of EEEs and improves the understanding about possible etiology of unexplained EEEs. The results provide a reference for genetic counseling regarding reproduction in the patient's family.

Progress and Prospects of Microplastic Biodegradation Processes and Mechanisms: A Bibliometric Analysis.

In order to visualize the content and development patterns of microplastic biodegradation research, the American Chemical Society (ACS), Elsevier, Springer Link, and American Society for Microbiology (ASM) were searched for the years 2012-2022 using Citespace and VOSvivewer for bibliometrics and visual analysis. The biodegradation processes and mechanisms of microplastics were reviewed on this basis. The results showed a sharp increase in the number of publications between 2012 and 2022, peaking in 2020-2021, with 62 more publications than the previous decade. The University of Chinese Academy of Sciences (UCAS), Northwest A&F University (NWAFU), and Chinese Academy of Agricultural Sciences (CAAS) are the top three research institutions in this field. Researchers are mainly located in China, The United States of America (USA), and India. Furthermore, the research in this field is primarily concerned with the screening of functional microorganisms, the determination of functional enzymes, and the analysis of microplastic biodegradation processes and mechanisms. These studies have revealed that the existing functional microorganisms for microplastic biodegradation are bacteria, predominantly Proteobacteria and Firmicutes; fungi, mainly Ascomycota; and some intestinal microorganisms. The main enzymes secreted in the process are hydrolase, oxidative, and depolymerization enzymes. Microorganisms degrade microplastics through the processes of colonization, biofilm retention, and bioenzymatic degradation. These studies have elucidated the current status of and problems in the microbial degradation of microplastics, and provide a direction for further research on the degradation process and molecular mechanism of functional microorganisms.

The nicotine demethylase CYP82E4 is essential for the formation of red dapples on flue-cured leaves of cherry-red tobacco.

Common flue-cured tobacco (Nicotiana tabacum L.) primarily accumulates nicotine, and its flue-cured leaves exhibit a lemon appearance. In contrast, a spontaneous cherry-red variant (CR60) primarily accumulates nornicotine, accompanied by distinctive red dapples on the cured leaves. In this study, suppression of conversion of nicotine to nornicotine by genome editing resulted in decreased nornicotine and N-acyl nornicotines (NacNNs), and the subsequent disappearance of red dapples in CR60. Conversely, overexpression of CYP82E4 increased nornicotine and NacNNs accumulation, inducing a red dapple phenotype in common tobacco. Notably, nicotine conversion triggered significant alterations in leaf total sugars, alkaloids, and nitrogens. Metabolome analyses using 1352 identified compounds indicated nicotine conversion dramatically affected the entire metabolic network and induced unique metabolic responses across diverse genetic backgrounds. Further WGCNA analysis revealed that nicotine conversion caused substantial contents variation of alkaloids, flavonoids and amino acids and derivatives in cured leaves. Overall, this research provides valuable insights into the mechanisms underlying red dapple formation in cherry-red tobacco, elucidating profound influence of nicotine conversion on entire metabolic network.

Complete genome sequence of a highly pathogenic porcine reproductive and respiratory syndrome virus variant.

Following the 2006 outbreaks of the highly pathogenic porcine reproductive and respiratory syndrome, the causative agent was identified as the highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV). To investigate whether the HP-PRRSV variant continues circulating and accelerating evolution, we sequenced and analyzed the complete genome of the identified HP-PRRSV field strain SD16. The sequence data indicate that the HP-PRRSV variant continues to prevail and accelerate evolution, especially in the nonstructural protein.

A novel porcine reproductive and respiratory syndrome virus vector system that stably expresses enhanced green fluorescent protein as a separate transcription unit.

Here we report the rescue of a recombinant porcine reproductive and respiratory syndrome virus (PRRSV) carrying an enhanced green fluorescent protein (EGFP) reporter gene as a separate transcription unit. A copy of the transcription regulatory sequence for ORF6 (TRS6) was inserted between the N protein and 3'-UTR to drive the transcription of the EGFP gene and yield a general purpose expression vector. Successful recovery of PRRSV was obtained using an RNA polymerase II promoter to drive transcription of the full-length virus genome, which was assembled in a bacterial artificial chromosome (BAC). The recombinant virus showed growth replication characteristics similar to those of the wild-type virus in the infected cells. In addition, the recombinant virus stably expressed EGFP for at least 10 passages. EGFP expression was detected at approximately 10 h post infection by live-cell imaging to follow the virus spread in real time and the infection of neighbouring cells occurred predominantly through cell-to-cell-contact. Finally, the recombinant virus generated was found to be an excellent tool for neutralising antibodies and antiviral compound screening. The newly established reverse genetics system for PRRSV could be a useful tool not only to monitor virus spread and screen for neutralising antibodies and antiviral compounds, but also for fundamental research on the biology of the virus.

The Top 100 Cited Articles on Acupuncture in the Last 20 Years: A Bibliometric Analysis.

BACKGROUND: Acupuncture has gained increasing international attention in recent decades. The act of incorporating acupuncture treatment into the routine treatment of COVID-19 in China drove us to review the 100 most influential articles of the last 20 years to learn about the current status and trends of acupuncture. METHOD: Articles related to acupuncture from January 1, 2001, to July 4, 2022, were searched in the Clarivate Analytics Web of Science Core Collection database. The top 100 most cited publications were selected, and information was extracted. Software such as VOSviewer, GraphPad Prism, Scimago Graphica, and CiteSpace were used to visualize and analyze the extracted data. RESULT: The 100 most cited articles were identified, with an average of 218 citations (range: 131-625). The majority of the top 100 articles were from the USA (n = 53). The institution that published the most highly cited papers was Harvard University (n = 16). The most influential team was Klaus Linde's group. Pain was the top-ranked journal in terms of the number of publications. The largest clusters for co-occurrence keyword analysis focused on acupuncture and electroacupuncture analgesia and brain imaging responses to acupuncture stimulation via functional MRI. The two highest strength burst keywords were "randomized controlled trials" and "osteoarthritis," with "randomized controlled trials" being a consistent burst keyword from 2011 to the present. CONCLUSION: This study provides insight into articles of historical significance in the field of acupuncture through bibliometric analysis. These data should provide clinicians and researchers with insight into future directions related to acupuncture.Die Akupunktur hat in den vergangenen Jahrzehnten zunehmend die internationale Aufmerksamkeit auf sich gezogen. Die Einbeziehung der Akupunktur in die Routinebehandlung von COVID-19 in China hat uns dazu veranlasst, die 100 einflussreichsten Artikel der letzten 20 Jahre zu überprüfen, um etwas über den aktuellen Stand und die Trends in der Akupunktur zu erfahren.Artikel mit Bezug zu Akupunktur vom 1. Januar 2001 bis 4. Juli 2022 wurden in der Clarivate Analytics Web of Science Core Collection Datenbank gesucht. Die 100 am häufigsten zitierten Veröffentlichungen wurden ausgewählt und die Informationen wurden extrahiert. Visualisierung und Analyse der extrahierten Daten erfolgten mithilfe der Software VOSviewer, GraphPad Prism, Scimago Graphica und CiteSpace.Es wurden die 100 am häufigsten zitierten Artikel ermittelt mit durchschnittlich 218 Zitierungen (Spanne: 131 bis 625). Der Großteil der 100 meistzitierten Artikel stammte aus den Vereinigten Staaten (n = 53). Die Institution, die die meisten zitierten Artikel veröffentlichte, war die Harvard-Universität (n = 16). Das einflussreichste Team war die Gruppe von Klaus Linde. Was die Zahl der Veröffentlichungen betrifft, war Pain die am häufigsten zitierte Zeitschrift. Bei der Analyse der Koinzidenz von Schlüsselwörtern lag der Fokus der größten Cluster auf Akupunktur-und Elektroakupunktur-Analgesie sowie auf den Reaktionen auf Akupunkturstimulation in den bildgebenden Untersuchungen des Gehirns mittels funktioneller MRT. Die beiden stärksten Burst-Schlüsselwörter waren "randomisierte kontrollierte Studien" und "Osteoarthritis," wobei "randomisierte kontrollierte Studien" von 2011 bis heute durchgängig ein Burst-Schlüsselwort ist.Diese Studie bietet einen Einblick in historisch bedeutsame Artikel auf dem Gebiet der Akupunktur mittels bibliometrischer analyse. Diese Daten sollen Klinikern und Forschern einen Einblick in zukünftige Richtungen im Zusammenhang mit Akupunktur geben.

The clinical spectrum associated with ATP1A2 variants in Chinese pediatric patients.

PURPOSE: To evaluate the clinical spectrum associated with ATP1A2 variants in Chinese children with hemiplegia, migraines, encephalopathy or seizures. METHODS: Sixteen children (12 males and 4 females), including ten patients with ATP1A2 variants whose cases had been published previously, were identified using next-generation sequencing. RESULTS: Fifteen patients had FHM2 (familial hemiplegic migraine type 2), including three who had AHC (alternating hemiplegia of childhood) and one who had drug-resistant focal epilepsy. Thirteen patients had DD (developmental delay). The onset of febrile seizures, which occurred between 5 months and 2 years 5 months (median 1 year 3 months) was earlier than the onset of HM (hemiplegic migraine), which occurred between 1 year 5 months and 13 years (median 3 years 11 months). Disturbance of consciousness subsided first, at 40 h to 9 days (median 4.5 days); hemiplegia and aphasia were resolved slowly, taking 30 min to 6 months (median 17.5 days) for the former and 24 h to over 1 year (median 14.5 days) for the latter. Cranial MRI showed edema in the cerebral hemispheres, mainly the left hemisphereacute attacks. All thirteen FHM2 patients recovered to baseline in 30 min to 6 months. Fifteen patients had between 1 and 7 (median 2) total attacks between the baseline and follow-up timepoints. We report twelve missense variants, including a novel variant ATP1A2 variant, p.G855E. CONCLUSIONS: The known genotypic and phenotypic spectra of Chinese patients with ATP1A2-related disorders were further expanded. Recurrent febrile seizures and DD combined with paroxysmal hemiplegia and encephalopathy should raise the clinical suspicion of FHM2. The avoidance of triggers and thus the prevention of attacks may be the most effective therapy for FHM2.

Efficacy and tolerability of oxcarbazepine in the treatment of focal epilepsy in neonates and infants under 3 months of age: A single-center retrospective analysis.

OBJECTIVE: The neonatal and infantile period is the age group with the highest incidence of epilepsy, in which gene variants in sodium and potassium channels are an important etiology, so the sodium channel blocker class of antiseizure medications may be effective in the treatment of early onset epilepsy. This study aimed to summarize the efficacy and tolerability of oxcarbazepine (OXC) in the treatment of focal epilepsy in neonates and infants under 3 months of age. METHODS: A retrospective analysis of children with focal epilepsy onset within 3 months of age and treated with OXC in a tertiary pediatric epilepsy center in China was conducted. The efficacy, tolerability and influencing factors of OXC were evaluated. RESULTS: A total of 50 patients were enrolled, with a median age of epilepsy onset of 11.5 (2, 42) days. There were 32 cases of early infantile developmental and epileptic encephalopathy, 10 cases of self-limited neonatal or neonatal-infantile epilepsy, and 8 cases of focal epilepsy that could not be classified as epileptic syndrome. The median age of application of OXC was 47 (31, 66) days. The median follow-up time was 16.5 (10, 25) months, with 7 deaths. Thirty-eight cases (76.0 %) were effective with OXC treatment, including 28 cases (56.0 %) achieved seizure freedom. Of the 34 cases whose pathogenesis involved genetic factors, 19 cases with sodium/ potassium channel gene variants had higher effective and seizure-free rates than those with other gene variants. The most common adverse event was transient hyponatremia. 2 cases had rash and 2 cases had abnormal electrocardiogram, 3 of which discontinued OXC. SIGNIFICANCE: This single-center retrospective study suggests that OXC is effective and tolerable for the treatment of focal epilepsy in neonates and infants under 3 months of age. The efficacy of OXC is better in patients with sodium/ potassium channel gene variants.

Mahalanobis distance based similarity regression learning of NIRS for quality assurance of tobacco product with different variable selection methods.

Quality assurance is one of the key issues in tobacco industry and many efforts have been put on the quality control. This paper introduces a new chemometrics technique to estimate the "quality similarity rate", which is used for quality control. The value of the quality similarity rate represents the similarity degree between the products and the standard reference samples, which is a global parameter that can be generated by either human assessors or machine learning. Supervised similarity regression models are built to automatically estimate the quality similarity rate value from NIRS data of tobacco leaf and smoke. For the similarity regression learning, the metric matrix is generated by a novel method which calculates the Mahalanobis distance from the segmented near infrared spectroscopy (NIRS). The results show the similarity regression learning can predict the quality similarity score well in high speed and can be improved with lasso (least absolute shrinkage and selection operator) related feature selection algorithms such as sRDA (sparse redundancy analysis) and glmnet.

Effect of hydroxyl on antioxidant properties of 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one to scavenge free radicals.

It is well known that 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP) is usually formed in the Maillard reaction and it contributes to the antioxidant properties of Maillard reaction intermediates. A series of hydroxyl group protected DDMP derivatives were synthesized to further understand the source of antioxidant activity. Antioxidant abilities of the DDMP derivatives were evaluated by scavenging the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTS˙+), 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH), and galvinoxyl radical, respectively. It was found that the introduction of protecting groups to the free hydroxyl groups of DDMP decreases their reducing abilities. In particular, the hydroxyl group at the olefin position exhibited a remarkable impact on the antioxidant activity of DDMP, indicating that the unstable enol structure in the DDMP moiety is the key factor for its antioxidant activity.

Interactions between Anaerobic Fungi and Methanogens in the Rumen and Their Biotechnological Potential in Biogas Production from Lignocellulosic Materials.

Anaerobic fungi in the digestive tract of herbivores are one of the critical types of fiber-degrading microorganisms present in the rumen. They degrade lignocellulosic materials using unique rhizoid structures and a diverse range of fiber-degrading enzymes, producing metabolic products such as H2/CO2, formate, lactate, acetate, and ethanol. Methanogens in the rumen utilize some of these products (e.g., H2 and formate) to produce methane. An investigation of the interactions between anaerobic fungi and methanogens is helpful as it provides valuable insight into the microbial interactions within the rumen. During the last few decades, research has demonstrated that anaerobic fungi stimulate the growth of methanogens and maintain methanogenic diversity. Meanwhile, methanogens increase the fiber-degrading capability of anaerobic fungi and stimulate metabolic pathways in the fungal hydrogenosome. The ability of co-cultures of anaerobic fungi and methanogens to degrade fiber and produce methane could potentially be a valuable method for the degradation of lignocellulosic materials and methane production.

Synthesis of 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one from maltol and its taste identification.

2,3-Dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP) exists in many foods, and its effect on taste is controversial. The aim of this study was to clarify whether DDMP has bitter taste or not. For this purpose, DDMP was synthesized from maltol instead of from glucose for the first time. In contrast, DDMP derived from glucose was also prepared and further purified. Their structures were identified by NMR and MS, and considered to be the same substance. The sensory analysis showed that DDMP derived from maltol was tasteless. Further studies indicated that some impurities in Maillard reaction made DDMP derived from glucose taste bitter.