Thirty- and 90-day Readmissions After Spinal Surgery for Spine Metastases: A National Trend Analysis of 4423 Patients.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The aim of this study was to investigate differences in 30- and 90-day readmissions for spine metastases treated with decompression and/or fusion spine surgery in a nationwide readmission database. SUMMARY OF BACKGROUND DATA: Patients with metastases to the spine represent a particularly vulnerable patient group that may encounter frequent readmissions. However, the 30- and 90-day rates for readmission following surgery for spine metastases have not been well described. METHODS: The Nationwide Readmission Database years 2013 to 2015 was queried. Patients were grouped by no readmission (non-R), readmission within 30 days (30-R), and readmission within 31 to 90 days (90-R). Weighted multivariate analysis assessed impact of treatment approach and clinical factors associated with 30- and 90-day readmissions. RESULTS: There were a total of 4423 patients with a diagnosis of spine metastases identified who underwent spine surgery, of which 1657 (37.5%) encountered either a 30-or 90-day unplanned readmission (30-R: n = 1068 [24-.1%]; 90-R: n = 589 [13.3%]; non-R: n = 2766). The most prevalent inpatient complications observed were postoperative infection (30-R: 16.3%, 90-R: 14.3%, non-R: 11.5%), acute post-hemorrhagic anemia (30-R: 13.4%, 90-R: 14.2%, non-R: 14.5%), and genitourinary complication (30-R: 5.7%, 90-R: 2.9%, non-R: 6.2%). The most prevalent 30-day and 90-day reasons for admission were sepsis (30-R: 10.2%, 90-R: 10.8%), postoperative infection (30-R: 13.7%, 90-R: 6.5%), and genitourinary complication (30-R: 3.9%, 90-R: 4.1%). On multivariate regression analysis, surgery type, age, hypertension, and renal failure were independently associated with 30-day readmission; rheumatoid arthritis/collagen vascular diseases, and coagulopathy were independently associated with 90-day readmission. CONCLUSION: In this study, we demonstrate several patient-level factors independently associated with unplanned hospital readmissions after surgical treatment intervention for spine metastases. Furthermore, we find that the most common reasons for readmission are sepsis, postoperative infection, and genitourinary complications.Level of Evidence: 3.

Constrained Output-Feedback Control for Discrete-Time Fuzzy Systems With Local Nonlinear Models Subject to State and Input Constraints.

This article presents a new approach to design static output-feedback (SOF) controllers for constrained Takagi-Sugeno fuzzy systems with nonlinear consequents. The proposed SOF fuzzy control framework is established via the absolute stability theory with appropriate sector-bounded properties of the local state and input nonlinearities. Moreover, both state and input constraints are explicitly taken into account in the control design using set-invariance arguments. Especially, we include the local sector-bounded nonlinearities of the fuzzy systems in the construction of both the nonlinear controller and the nonquadratic Lyapunov function. Within the considered local control context, the new class of nonquadratic Lyapunov functions provides an effective solution to estimate the closed-loop domain of attraction, which can be nonconvex and even disconnected. The convexification procedure is performed using specific congruence transformations in accordance with the special structures of the proposed SOF controllers and nonquadratic Lyapunov functions. Consequently, the fuzzy SOF control design can be reformulated as an optimization problem under strict linear matrix inequality constraints with a linear search parameter. Compared to existing fuzzy SOF control schemes, the new structures of the control law and the Lyapunov function are more general and offer additional degrees of freedom for the control design. Both theoretical arguments and numerical illustrations are provided to demonstrate the effectiveness of the proposed approach in reducing the design conservatism.

Lignin from oil palm empty fruit bunches: Characterization, biological activities and application in green synthesis of silver nanoparticles.

Lignin was extracted from oil palm empty fruit bunches under four different conditions. The lignin samples were characterized and employed in the green synthesis of silver nanoparticles. Two-dimensional HSQC NMR analysis showed that lignins extracted under more aggressive conditions (3.5% acid, 60 min) exhibited less signals and thus, presented a more degraded chemical structure. Additionally, those lignins obtained under harsh conditions (3.5% acid, 60 min) exhibited higher antioxidant capacity than those obtained under mild conditions (1.5% acid, 20 min). Formation of lignin-mediated silver nanoparticles was confirmed by color change during their synthesis. The surface plasmon resonance peaks (423-427 nm) in UV-visible spectra also confirmed the synthesis of AgNPs. AgNPs showed spherical shape, polycrystalline nature and average size between 18 and 20 nm. AgNPs, in suspension, presented a negative Zeta potential profile. Lignin was assumed to contribute in the antioxidant capacity exhibited by AgNPs. All AgNPs presented no significant differences on the disk diffusion antimicrobial susceptibility test against E. coli. The minimum inhibitory concentration of HAL3-L AgNPs (62.5 µg·mL-1) was better than other physicochemically produced AgNPs (100 µg·mL-1).

Characterization and psychological aspects of patients with erectile dysfunction / Caracterização e aspectos psicológicos de pacientes com disfunção erétil / Caracterización y aspectos psicológicos de pacientes con disfunción eréctil

This study aimed to characterize patients with erectile dysfunction (ED) evaluated by the psychologist who participates in the Urology team of a teaching hospital. The following data from medical records of patients treated between January / 2011 and April / 2015 were analyzed: 1) the urologist's referral, with diagnosis and the reason for the request for psychological evaluation; 2) the patient's psychological records, filed at the Psychology Service. Data of 233 male patients were analyzed, who had a mean age of .34 ± 1.18 and a high prevalence of ED of organic cause (72.1%). Organic, psychological factors and lifestyle associated with the etiology of ED were identified: behavioral (smoking and alcohol consumption.), advanced age, prostate cancer, premature ejaculation, depression, and anxiety. Data pointed out the importance of psychological assessment associated with the medical diagnosis of ED to provide proper treatment.

Este estudo teve como objetivo caracterizar pacientes com disfunção erétil (DE) avaliados pelo psicólogo que participa da equipe de urologia de um hospital de ensino. Foram analisados os seguintes dados dos prontuários de pacientes atendidos entre janeiro de 2011 e abril de 2015: 1. encaminhamento do urologista, com diagnóstico e motivo da solicitação para avaliação psicológica e 2. prontuário psicológico do paciente, arquivado no ambulatório de psicologia. Analisaram-se dados de 233 pacientes do sexo masculino, com média de idade 57,34 ± 1,18 e alta prevalência da DE de causa orgânica (72,1%). Fatores orgânicos, psicológicos e estilo de vida associados à etiologia da DE foram identificados: comportamentais (tabagismo e etilismo), idade avançada, câncer de próstata, ejaculação precoce, depressão e ansiedade. Os dados indicam a importância da avaliação psicológica associada ao diagnóstico médico da DE para fornecer o tratamento adequado.

Este estudio tuvo como objetivo caracterizar a pacientes con disfunción eréctil (DE) evaluados por el psicólogo que participa del equipo de urología de un hospital de enseñanza. Se analizaron los siguientes datos de los prontuarios de pacientes atendidos entre enero/2011 y abril/2015: 1. encaminamiento del urólogo, con diagnóstico y motivo de la solicitud para evaluación psicológica y 2. prontuario psicológico del paciente, archivado en el ambulatorio de psicología. Se analizaron datos de 233 pacientes del sexo masculino, con media de edad 57,34 ± 1,18 y alta prevalencia de la DE de causa orgánica (72,1%). Los factores orgánicos, psicológicos y estilo de vida asociados a la etiología de la DE fueron identificados: comportamentales (tabaquismo y etilismo), edad avanzada, cáncer de próstata, eyaculación precoz, depresión y ansiedad. Los datos indican la importancia de la evaluación psicológica asociada al diagnóstico médico de la DE, para proporcionar el tratamiento adecuado.

Associated risk factors for extended length of stay following anterior cervical discectomy and fusion for cervical spondylotic myelopathy.

OBJECTIVES: There is a paucity of literature describing the predictors associated with extended length of hospital stay (LOS) for patients undergoing anterior cervical discectomy and fusion (ACDF) for cervical spondylotic myelopathy. The aim of this study was to identify the patient- and hospital-level factors associated with extended LOS for patients with cervical spondylotic myelopathy undergoing ACDF. PATIENTS AND METHODS: The National Inpatient Sample database was queried to identify patients with a diagnosis of cervical spondylotic myelopathy undergoing ACDF between 2010 and 2014. Updated trend weights were used to assess patient demographics, comorbidities, complications, LOS, discharge disposition and total cost. Multivariate logistic regression was used to determine the odds ratio for risk-adjusted LOS. The primary outcome was the degree to which patient comorbidities or postoperative complications correlated with extended LOS (>3 days). RESULTS: We identified 144,514 patients with 29,947 (20.7%) experiencing an extended LOS (Normal LOS: 114,567; Extended LOS: 29,947). Comorbidities were overall significantly higher in the extended LOS cohort compared to the normal LOS cohort. Patients with extended LOS had a significantly greater proportion of blood transfusion (p < 0.001) and 2-3 vertebral levels fused (p < 0.001). The overall complication rates were greater in the extended LOS cohort (Normal LOS: 7.4% vs. Extended LOS: 44.8%, p < 0.001). The extended LOS cohort incurred $14,489 more in total cost (Normal LOS: $15,486 [11,787-20,623] vs. Extended LOS: $29,975 [21,286-45,285], p < 0.001) and had more patients discharged to non-routine locations (p < 0.001) compared to the normal LOS cohort. On multivariate logistic regression, several risk-factors were associated with extended LOS including: age, male gender, Black and Hispanic race, patient income, insurance, multiple comorbidities, blood transfusion, and number of complications. The odds ratio for extended LOS was 5.15 (95% CI: 4.68-5.67) for patients with 1 complication and 25.54 (95% CI: 20.54-31.75) for patients with >1 complication. CONCLUSION: Our national cohort study demonstrated multiple patient- and hospital-level factors associated with extended LOS (>3 days) after ACDF for CSM. Specifically, patients with an extended LOS had lower socioeconomic status, higher rate of comorbidities, greater percentage of postoperative complications and non-routine discharges, with greater overall costs. Further investigational studies are necessary to identify quality improvement strategies targeted to better optimizing patients preoperatively and reducing perioperative complications in order to improve quality of patient care and reduce hospital LOS.

Perioperative Outcomes in 17,947 Patients Undergoing 2-Level Anterior Cervical Discectomy and Fusion Versus 1-Level Anterior Cervical Corpectomy for Treatment of Cervical Degenerative Conditions: A Propensity Score Matched National Surgical Quality Improvement Program Analysis.

OBJECTIVE: To compare the perioperative morbidity of 2-level anterior cervical discectomy and fusion (ACDF) with that of 1-level anterior cervical corpectomy and fusion (ACCF) for the treatment of cervical degenerative conditions. METHODS: A retrospective study of the 2005-2016 National Surgical Quality Improvement Program database for patients undergoing 2-level ACDF and 1-level ACCF was performed. Patient data included: age, sex, body mass index (BMI), functional status, and American Society of Anesthesiologists (ASA) physical status (PS) classification. Hospital data included: operative time and length of hospital stay (LOS). Thirty-day outcome data included: any, serious, and minor adverse events, return to the operating room, readmission, and mortality. After propensity matching for age, sex, ASA PS classification, functional status, and BMI, multivariate logistic regression analysis was used to compare outcomes between the 2 propensity-matched subcohorts. Finally, multivariate logistic regression that additionally controlled for operative time was performed to compare the 2 propensity-matched subcohorts. RESULTS: A total of 17,497 cases were identified, with 90.20% undergoing 2-level ACDF and 9.80% undergoing 1-level ACCF. Patients undergoing 2-level ACDF were younger, more likely to be female, had higher functional status, and had shorter operative time and LOS (p < 0.001). After propensity score matching, cases undergoing 1-level ACCF had a statistically significant higher rate of serious adverse events (p = 0.005). This difference was no longer significant after controlling for operative time. CONCLUSION: While there was noted to be additional morbidity in 1-level ACCF cases relative to 2-level ACDF cases, the lack of difference once controlling for the surgical time supports using the procedure that best accomplishes the surgical objectives.

Perspectives of healthcare workers on the morality of abortion: a multicenter study in seven Brazilian public hospitals.

We used the questionnaire "Mosaic of Opinions on Induced Abortion" to conduct a multi-centered study to evaluate the perspectives of physicians, nurses, social workers, psychologists and pharmacists on the morality of abortion. In all, 254 participants constituted the sample. The inadequate knowledge on Brazilian abortion laws was the only determinant negatively associated with the construct "Sexual and Reproductive Rights", corroborating the hypothesis that a better understanding of abortion legislation could mitigate the opposition of some professionals to the ethical perspective that access to safe abortion should be seen as a sexual and reproductive right.

Intrinsic dynamic behavior of enzyme:substrate complexes govern the catalytic action of ß-galactosidases across clan GH-A.

The conformational itineraries taken by carbohydrate residues in the catalytic subsite of retaining glycoside hydrolases (GHs), harness the link between substrate conformation and reactivity. GHs' active sites may be described as a combination of subsites dedicated to the binding of individual sugar residues and to catalysis. The three-dimensional structure of GH:carbohydrate complexes has demonstrated that carbohydrate ring conformation changes in an ordered manner during catalysis. Here we demonstrate in silico that a link exists between subsite binding dynamics and substrate specificity for ß-galactosidases from clan GH-A families GH1, GH2, GH35, GH42 and GH59. Different oligosaccharides were docked in the active site of reference ß-galactosidase structures using Vina-Carb. Subsequent molecular dynamics (MD) simulations revealed that these enzymes favor a high degree of flexibility and ring distortion of the substrate the lytic subsite -1. Although the ß-galactosidase families examined are structurally and mechanistically related, distinct patterns of ring distortion were unveiled for the different families. For ß-galactosidases, three different family-dependent reaction itineraries (1S3 → 4H3‡ → 4C1, 1,4B → 4H3/ 4E‡ → 4C1, and 1S5 → 4E/ 4H5‡ → 4C1) were identified, all compatible with the antiperiplanar lone pair hypothesis (ALPH) for the hydrolysis of ß-glycosides. This comparative study reveals the fuzzy character of the changes in carbohydrate ring geometry prior to carbohydrate hydrolysis.

Tracking of enzymatic biomass deconstruction by fungal secretomes highlights markers of lignocellulose recalcitrance.

BACKGROUND: Lignocellulose biomass is known as a recalcitrant material towards enzymatic hydrolysis, increasing the process cost in biorefinery. In nature, filamentous fungi naturally degrade lignocellulose, using an arsenal of hydrolytic and oxidative enzymes. Assessment of enzyme hydrolysis efficiency generally relies on the yield of glucose for a given biomass. To better understand the markers governing recalcitrance to enzymatic degradation, there is a need to enlarge the set of parameters followed during deconstruction. RESULTS: Industrially-pretreated biomass feedstocks from wheat straw, miscanthus and poplar were sequentially hydrolysed following two steps. First, standard secretome from Trichoderma reesei was used to maximize cellulose hydrolysis, producing three recalcitrant lignin-enriched solid substrates. Then fungal secretomes from three basidiomycete saprotrophs (Laetisaria arvalis, Artolenzites elegans and Trametes ljubarskyi) displaying various hydrolytic and oxidative enzymatic profiles were applied to these recalcitrant substrates, and compared to the T. reesei secretome. As a result, most of the glucose was released after the first hydrolysis step. After the second hydrolysis step, half of the remaining glucose amount was released. Overall, glucose yield after the two sequential hydrolyses was more dependent on the biomass source than on the fungal secretomes enzymatic profile. Solid residues obtained after the two hydrolysis steps were characterized using complementary methodologies. Correlation analysis of several physico-chemical parameters showed that released glucose yield was negatively correlated with lignin content and cellulose crystallinity while positively correlated with xylose content and water sorption. Water sorption appears as a pivotal marker of the recalcitrance as it reflects chemical and structural properties of lignocellulosic biomass. CONCLUSIONS: Fungal secretomes applied to highly recalcitrant biomass samples can further extend the release of the remaining glucose. The glucose yield can be correlated to chemical and physical markers, which appear to be independent from the biomass type and secretome. Overall, correlations between these markers reveal how nano-scale properties (polymer content and organization) influence macro-scale properties (particle size and water sorption). Further systematic assessment of these markers during enzymatic degradation will foster the development of novel cocktails to unlock the degradation of lignocellulose biomass.

Measurement properties of the questionnaire "Mosaic of opinions on induced abortion": a multicenter study in seven Brazilian hospitals.

OBJECTIVE: In Brasil, abortion is legal in cases of rape, when there is a risk of maternal death, and in cases of fetal anencephaly. However, the literature reports that some doctors refuse to care for women with such demands or come to perform it in a discriminatory manner. Pretest, test and evaluate the measurement properties of the "Mosaic of Opinions on Induced Abortion," a questionnaire developed to investigate the perspectives of Brazilian healthcare professionals about the morality of abortion. METHODS: Firstly, the questionnaire was pretested in an intentional sample of specialists. Secondly, it was tested in a randomized sample of 32 healthcare professionals. Finally, we conducted a multi-center study in seven university hospitals to evaluate the measurement properties of the questionnaire. RESULTS: Combined samples of the three phases totalized 430 individuals. In pretest and test, all the evaluated aspects obtained satisfactory results. In the multicenter phase, confirmatory factorial analysis led to an important reduction of the questionnaire, which also obtained good indicators of reliability, beyond the validation of construct and criteria. CONCLUSION: Questionnaire has been validated and is suitable for use in other surveys in Brasil.

Measurement properties of the questionnaire "Mosaic of opinions on induced abortion": a multicenter study in seven Brazilian hospitals

SUMMARY In Brasil, abortion is legal in cases of rape, when there is a risk of maternal death, and in cases of fetal anencephaly. However, the literature reports that some doctors refuse to care for women with such demands or come to perform it in a discriminatory manner. OBJECTIVE: Pretest, test and evaluate the measurement properties of the "Mosaic of Opinions on Induced Abortion," a questionnaire developed to investigate the perspectives of Brazilian healthcare professionals about the morality of abortion. METHODS: Firstly, the questionnaire was pretested in an intentional sample of specialists. Secondly, it was tested in a randomized sample of 32 healthcare professionals. Finally, we conducted a multi-center study in seven university hospitals to evaluate the measurement properties of the questionnaire. RESULTS: Combined samples of the three phases totalized 430 individuals. In pretest and test, all the evaluated aspects obtained satisfactory results. In the multicenter phase, confirmatory factorial analysis led to an important reduction of the questionnaire, which also obtained good indicators of reliability, beyond the validation of construct and criteria. CONCLUSION: Questionnaire has been validated and is suitable for use in other surveys in Brasil.

RESUMO RESUMO: No Brasil, o aborto induzido é permitido por lei em casos de estupro, risco de morte para a gestante e anencefalia fetal. Entretanto, a literatura relata que alguns médicos recusam atender mulheres com tais demandas, ou o fazem de maneira discriminatória. OBJETIVO: Pré-testar, testar e avaliar as propriedades da medida do "Mosaico de opiniões sobre o aborto induzido", um questionário para investigar as perspectivas de profissionais da saúde brasileiros sobre a moralidade do aborto. MÉTODOS: Primeiro, o questionário foi pré-testado em uma amostra intencional de especialistas. Em segundo lugar, foi testado em uma amostra aleatória de 32 profissionais da saúde. Finalmente, conduziu-se um estudo multicêntrico em sete hospitais universitários para avaliar as propriedades da medida do questionário. RESULTADOS: Combinadas, as amostras das três fases totalizaram 430 sujeitos. No pré-teste e no teste, todos os aspectos avaliados obtiveram resultados satisfatórios. Na fase multicêntrica, a análise fatorial confirmatória levou a uma importante redução do questionário, que também obteve bons indicadores de confiabilidade, além da validade de construto e de critério. CONCLUSÕES: O questionário foi validado e encontra-se apto para ser utilizado em outras pesquisas no Brasil.

The chimeric nature of the genomes of marine magnetotactic coccoid-ovoid bacteria defines a novel group of Proteobacteria.

Magnetotactic bacteria (MTB) are a group of phylogenetically and physiologically diverse Gram-negative bacteria that synthesize intracellular magnetic crystals named magnetosomes. MTB are affiliated with three classes of Proteobacteria phylum, Nitrospirae phylum, Omnitrophica phylum and probably with the candidate phylum Latescibacteria. The evolutionary origin and physiological diversity of MTB compared with other bacterial taxonomic groups remain to be illustrated. Here, we analysed the genome of the marine magneto-ovoid strain MO-1 and found that it is closely related to Magnetococcus marinus MC-1. Detailed analyses of the ribosomal proteins and whole proteomes of 390 genomes reveal that, among the Proteobacteria analysed, only MO-1 and MC-1 have coding sequences (CDSs) with a similarly high proportion of origins from Alphaproteobacteria, Betaproteobacteria, Deltaproteobacteria and Gammaproteobacteria. Interestingly, a comparative metabolic network analysis with anoxic network enzymes from sequenced MTB and non-MTB successfully allows the eventual prediction of an organism with a metabolic profile compatible for magnetosome production. Altogether, our genomic analysis reveals multiple origins of MO-1 and M. marinus MC-1 genomes and suggests a metabolism-restriction model for explaining whether a bacterium could become an MTB upon acquisition of magnetosome encoding genes.

Composting-Like Conditions Are More Efficient for Enrichment and Diversity of Organisms Containing Cellulase-Encoding Genes than Submerged Cultures.

Cost-effective biofuel production from lignocellulosic biomass depends on efficient degradation of the plant cell wall. One of the major obstacles for the development of a cost-efficient process is the lack of resistance of currently used fungal enzymes to harsh conditions such as high temperature. Adapted, thermophilic microbial communities provide a huge reservoir of potentially interesting lignocellulose-degrading enzymes for improvement of the cellulose hydrolysis step. In order to identify such enzymes, a leaf and wood chip compost was enriched on a mixture of thermo-chemically pretreated wheat straw, poplar and Miscanthus under thermophile conditions, but in two different set-ups. Unexpectedly, metagenome sequencing revealed that incubation of the lignocellulosic substrate with compost as inoculum in a suspension culture resulted in an impoverishment of putative cellulase- and hemicellulase-encoding genes. However, mimicking composting conditions without liquid phase yielded a high number and diversity of glycoside hydrolase genes and an enrichment of genes encoding cellulose binding domains. These identified genes were most closely related to species from Actinobacteria, which seem to constitute important players of lignocellulose degradation under the applied conditions. The study highlights that subtle changes in an enrichment set-up can have an important impact on composition and functions of the microcosm. Composting-like conditions were found to be the most successful method for enrichment in species with high biomass degrading capacity.

Complexity of the Ruminococcus flavefaciens cellulosome reflects an expansion in glycan recognition.

The breakdown of plant cell wall (PCW) glycans is an important biological and industrial process. Noncatalytic carbohydrate binding modules (CBMs) fulfill a critical targeting function in PCW depolymerization. Defining the portfolio of CBMs, the CBMome, of a PCW degrading system is central to understanding the mechanisms by which microbes depolymerize their target substrates. Ruminococcus flavefaciens, a major PCW degrading bacterium, assembles its catalytic apparatus into a large multienzyme complex, the cellulosome. Significantly, bioinformatic analyses of the R. flavefaciens cellulosome failed to identify a CBM predicted to bind to crystalline cellulose, a key feature of the CBMome of other PCW degrading systems. Here, high throughput screening of 177 protein modules of unknown function was used to determine the complete CBMome of R. flavefaciens The data identified six previously unidentified CBM families that targeted ß-glucans, ß-mannans, and the pectic polysaccharide homogalacturonan. The crystal structures of four CBMs, in conjunction with site-directed mutagenesis, provide insight into the mechanism of ligand recognition. In the CBMs that recognize ß-glucans and ß-mannans, differences in the conformation of conserved aromatic residues had a significant impact on the topology of the ligand binding cleft and thus ligand specificity. A cluster of basic residues in CBM77 confers calcium-independent recognition of homogalacturonan, indicating that the carboxylates of galacturonic acid are key specificity determinants. This report shows that the extended repertoire of proteins in the cellulosome of R. flavefaciens contributes to an extended CBMome that supports efficient PCW degradation in the absence of CBMs that specifically target crystalline cellulose.

Closely related fungi employ diverse enzymatic strategies to degrade plant biomass.

BACKGROUND: Plant biomass is the major substrate for the production of biofuels and biochemicals, as well as food, textiles and other products. It is also the major carbon source for many fungi and enzymes of these fungi are essential for the depolymerization of plant polysaccharides in industrial processes. This is a highly complex process that involves a large number of extracellular enzymes as well as non-hydrolytic proteins, whose production in fungi is controlled by a set of transcriptional regulators. Aspergillus species form one of the best studied fungal genera in this field, and several species are used for the production of commercial enzyme cocktails. RESULTS: It is often assumed that related fungi use similar enzymatic approaches to degrade plant polysaccharides. In this study we have compared the genomic content and the enzymes produced by eight Aspergilli for the degradation of plant biomass. All tested Aspergilli have a similar genomic potential to degrade plant biomass, with the exception of A. clavatus that has a strongly reduced pectinolytic ability. Despite this similar genomic potential their approaches to degrade plant biomass differ markedly in the overall activities as well as the specific enzymes they employ. While many of the genes have orthologs in (nearly) all tested species, only very few of the corresponding enzymes are produced by all species during growth on wheat bran or sugar beet pulp. In addition, significant differences were observed between the enzyme sets produced on these feedstocks, largely correlating with their polysaccharide composition. CONCLUSIONS: These data demonstrate that Aspergillus species and possibly also other related fungi employ significantly different approaches to degrade plant biomass. This makes sense from an ecological perspective where mixed populations of fungi together degrade plant biomass. The results of this study indicate that combining the approaches from different species could result in improved enzyme mixtures for industrial applications, in particular saccharification of plant biomass for biofuel production. Such an approach may result in a much better improvement of saccharification efficiency than adding specific enzymes to the mixture of a single fungus, which is currently the most common approach used in biotechnology.

Fast solubilization of recalcitrant cellulosic biomass by the basidiomycete fungus Laetisaria arvalis involves successive secretion of oxidative and hydrolytic enzymes.

BACKGROUND: Enzymatic breakdown of lignocellulosic biomass is a known bottleneck for the production of high-value molecules and biofuels from renewable sources. Filamentous fungi are the predominant natural source of enzymes acting on lignocellulose. We describe the extraordinary cellulose-deconstructing capacity of the basidiomycete Laetisaria arvalis, a soil-inhabiting fungus. RESULTS: The L. arvalis strain displayed the capacity to grow on wheat straw as the sole carbon source and to fully digest cellulose filter paper. The cellulolytic activity exhibited in the secretomes of L. arvalis was up to 7.5 times higher than that of a reference Trichoderma reesei industrial strain, resulting in a significant improvement of the glucose release from steam-exploded wheat straw. Global transcriptome and secretome analyses revealed that L. arvalis produces a unique repertoire of carbohydrate-active enzymes in the fungal taxa, including a complete set of enzymes acting on cellulose. Temporal analyses of secretomes indicated that the unusual degradation efficiency of L. arvalis relies on its early response to the carbon source, and on the finely tuned sequential secretion of several lytic polysaccharide monooxygenases and hydrolytic enzymes targeting cellulose. CONCLUSIONS: The present study illustrates the adaptation of a litter-rot fungus to the rapid breakdown of recalcitrant plant biomass. The cellulolytic capabilities of this basidiomycete fungus result from the rapid, selective and successive secretion of oxidative and hydrolytic enzymes. These enzymes expressed at critical times during biomass degradation may inspire the design of improved enzyme cocktails for the conversion of plant cell wall resources into fermentable sugars.

Genomic and transcriptomic analysis of Laccaria bicolor CAZome reveals insights into polysaccharides remodelling during symbiosis establishment.

Ectomycorrhizal fungi, living in soil forests, are required microorganisms to sustain tree growth and productivity. The establishment of mutualistic interaction with roots to form ectomycorrhiza (ECM) is not well known at the molecular level. In particular, how fungal and plant cell walls are rearranged to establish a fully functional ectomycorrhiza is poorly understood. Nevertheless, it is likely that Carbohydrate Active enZymes (CAZyme) produced by the fungus participate in this process. Genome-wide transcriptome profiling during ECM development was used to examine how the CAZome of Laccaria bicolor is regulated during symbiosis establishment. CAZymes active on fungal cell wall were upregulated during ECM development in particular after 4weeks of contact when the hyphae are surrounding the root cells and start to colonize the apoplast. We demonstrated that one expansin-like protein, whose expression is specific to symbiotic tissues, localizes within fungal cell wall. Whereas L. bicolor genome contained a constricted repertoire of CAZymes active on cellulose and hemicellulose, these CAZymes were expressed during the first steps of root cells colonization. L. bicolor retained the ability to use homogalacturonan, a pectin-derived substrate, as carbon source. CAZymes likely involved in pectin hydrolysis were mainly expressed at the stage of a fully mature ECM. All together, our data suggest an active remodelling of fungal cell wall with a possible involvement of expansin during ECM development. By contrast, a soft remodelling of the plant cell wall likely occurs through the loosening of the cellulose microfibrils by AA9 or GH12 CAZymes and middle lamella smooth remodelling through pectin (homogalacturonan) hydrolysis likely by GH28, GH12 CAZymes.

Carbohydrate-related enzymes of important Phytophthora plant pathogens.

Carbohydrate-Active enZymes (CAZymes) form particularly interesting targets to study in plant pathogens. Despite the fact that many CAZymes are pathogenicity factors, oomycete CAZymes have received significantly less attention than effectors in the literature. Here we present an analysis of the CAZymes present in the Phytophthora infestans, Ph. ramorum, Ph. sojae and Pythium ultimum genomes compared to growth of these species on a range of different carbon sources. Growth on these carbon sources indicates that the size of enzyme families involved in degradation of cell-wall related substrates like cellulose, xylan and pectin is not always a good predictor of growth on these substrates. While a capacity to degrade xylan and cellulose exists the products are not fully saccharified and used as a carbon source. The Phytophthora genomes encode larger CAZyme sets when compared to Py. ultimum, and encode putative cutinases, GH12 xyloglucanases and GH10 xylanases that are missing in the Py. ultimum genome. Phytophthora spp. also encode a larger number of enzyme families and genes involved in pectin degradation. No loss or gain of complete enzyme families was found between the Phytophthora genomes, but there are some marked differences in the size of some enzyme families.

Rumen cellulosomics: divergent fiber-degrading strategies revealed by comparative genome-wide analysis of six ruminococcal strains.

BACKGROUND: A complex community of microorganisms is responsible for efficient plant cell wall digestion by many herbivores, notably the ruminants. Understanding the different fibrolytic mechanisms utilized by these bacteria has been of great interest in agricultural and technological fields, reinforced more recently by current efforts to convert cellulosic biomass to biofuels. METHODOLOGY/PRINCIPAL FINDINGS: Here, we have used a bioinformatics-based approach to explore the cellulosome-related components of six genomes from two of the primary fiber-degrading bacteria in the rumen: Ruminococcus flavefaciens (strains FD-1, 007c and 17) and Ruminococcus albus (strains 7, 8 and SY3). The genomes of two of these strains are reported for the first time herein. The data reveal that the three R. flavefaciens strains encode for an elaborate reservoir of cohesin- and dockerin-containing proteins, whereas the three R. albus strains are cohesin-deficient and encode mainly dockerins and a unique family of cell-anchoring carbohydrate-binding modules (family 37). CONCLUSIONS/SIGNIFICANCE: Our comparative genome-wide analysis pinpoints rare and novel strain-specific protein architectures and provides an exhaustive profile of their numerous lignocellulose-degrading enzymes. This work provides blueprints of the divergent cellulolytic systems in these two prominent fibrolytic rumen bacterial species, each of which reflects a distinct mechanistic model for efficient degradation of cellulosic biomass.