scholarly journals Deciphering the unique cellulose degradation mechanism of the ruminal bacterium Fibrobacter succinogenes S85

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Mahendra P. Raut ◽  
Narciso Couto ◽  
Esther Karunakaran ◽  
Catherine A. Biggs ◽  
Phillip C. Wright
Keyword(s):  
Cellulose Degradation ◽  
Cell Envelope ◽  
Degradation Mechanism ◽  
Protein Profile ◽  
Lignocellulose Degradation ◽  
Fibrobacter Succinogenes ◽  
Molecular Features ◽  
Associated Proteins ◽  
Lignocellulosic Biofuels ◽  
First Time

Abstract Fibrobacter succinogenes S85, isolated from the rumen of herbivores, is capable of robust lignocellulose degradation. However, the mechanism by which it achieves this is not fully elucidated. In this study, we have undertaken the most comprehensive quantitative proteomic analysis, to date, of the changes in the cell envelope protein profile of F. succinogenes S85 in response to growth on cellulose. Our results indicate that the cell envelope proteome undergoes extensive rearrangements to accommodate the cellulolytic degradation machinery, as well as associated proteins involved in adhesion to cellulose and transport and metabolism of cellulolytic products. Molecular features of the lignocellulolytic enzymes suggest that the Type IX secretion system is involved in the translocation of these enzymes to the cell envelope. Finally, we demonstrate, for the first time, that cyclic-di-GMP may play a role in mediating catabolite repression, thereby facilitating the expression of proteins involved in the adhesion to lignocellulose and subsequent lignocellulose degradation and utilisation. Understanding the fundamental aspects of lignocellulose degradation in F. succinogenes will aid the development of advanced lignocellulosic biofuels.

scholarly journals Publisher Correction: Deciphering the unique cellulose degradation mechanism of the ruminal bacterium Fibrobacter succinogenes S85

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Mahendra P. Raut ◽  
Narciso Couto ◽  
Esther Karunakaran ◽  
Catherine A. Biggs ◽  
Phillip C. Wright
Keyword(s):  
Cellulose Degradation ◽  
Degradation Mechanism ◽  
Fibrobacter Succinogenes ◽  
Ruminal Bacterium

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Studies on Lignocellulose Degradation by Rumen Microorganism

2013 ◽  
Vol 853 ◽  
pp. 253-259 ◽  
Author(s):  
Guan Rong Wang ◽  
Yu Lin Duan
Keyword(s):  
Cellulose Degradation ◽  
Agricultural Waste ◽  
Complex Structure ◽  
Renewable Resource ◽  
Research Progress ◽  
Lignocellulose Degradation ◽  
Enzymatic Characterization ◽  
Rumen Microorganisms ◽  
Microbial Metagenomics ◽  
Energy Processing

Lignocellulosic material is the earth's most abundant renewable resource, but because of its stable and complex structure, it is not easy for depredating and utilizing for a long time. Rumen can degrade lignocellulose, and is one of nature's most efficient fermentation fermenter; to be study rumen microorganisms has the potential to provide valuable solutions to renewable energy, processing of agricultural waste, organic waste etc. Research methods vary from screening of cellulose-degradation bacteria, enzymatic characterization, to the use of metagenomics technology to get a large number of genes directly from the rumen. This article reviews the characteristics, mechanism and contribution of different rumen microbial in degradation of lignocellulose, as well as the research progress of enzymatic characterization and rumen microbial metagenomics.

scholarly journals Compartmentalized Cell Envelope Biosynthesis in Mycobacterium tuberculosis

2022 ◽  
Author(s):  
Julia Puffal ◽  
Ian L. Sparks ◽  
James R. Brenner ◽  
Xuni Li ◽  
John D. Leszyk ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Proteomic Analysis ◽  
Fluorescent Protein ◽  
Cell Envelope ◽  
Membrane Domain ◽  
Protein Fusion ◽  
Final Maturation ◽  
Associated Proteins ◽  
Gradient Fractionation ◽  
Membrane Compartmentalization

The intracellular membrane domain (IMD) is a metabolically active and laterally discrete membrane domain initially discovered in Mycobacterium smegmatis. The IMD correlates both temporally and spatially with the polar cell envelope elongation in M. smegmatis. Whether or not a similar membrane domain exists in pathogenic species remains unknown. Here we show that the IMD is a conserved membrane structure found in Mycobacterium tuberculosis. We used two independent approaches, density gradient fractionation of membrane domains and visualization of IMD-associated proteins through fluorescence microscopy, to determine the characteristics of the plasma membrane compartmentalization in M. tuberculosis. Proteomic analysis revealed that the IMD is enriched in metabolic enzymes that are involved in the synthesis of conserved cell envelope components such as peptidoglycan, arabinogalactan, and phosphatidylinositol mannosides. Using a fluorescent protein fusion of IMD-associated proteins, we demonstrated that this domain is concentrated in the polar region of the rod-shaped cells, where active cell envelope biosynthesis is taking place. Proteomic analysis further revealed the enrichment of enzymes involved in synthesis of phthiocerol dimycocerosates and phenolic glycolipids in the IMD. We validated the IMD association of two enzymes, α1,3-fucosyltransferase and fucosyl 4-O-methyltransferase, which are involved in the final maturation steps of phenolic glycolipid biosynthesis. Taken together, these data indicate that functional compartmentalization of membrane is an evolutionarily conserved feature found in both M. tuberculosis and M. smegmatis, and M. tuberculosis utilizes this membrane location for the synthesis of its surface-exposed lipid virulence factors.

scholarly journals Molecular architecture of theLegionellaDot/Icm type IV secretion system

2018 ◽  
Author(s):  
Debnath Ghosal ◽  
Yi-Wei Chang ◽  
Kwang Cheol Jeong ◽  
Joseph P. Vogel ◽  
Grant J. Jensen
Keyword(s):  
Legionella Pneumophila ◽  
Cell Envelope ◽  
Secretion System ◽  
Host Cells ◽  
Molecular Architecture ◽  
Intact Cells ◽  
Type Iv ◽  
Type Ivb Secretion ◽  
Electron Cryotomography ◽  
First Time

AbstractLegionella pneumophilasurvives and replicates inside host cells by secreting ~300 effectors through the Dot/Icm type IVB secretion system (T4BSS). Understanding this machine’s structure is challenging because of its large number of components (27) and integration into all layers of the cell envelope. Previously we overcame this obstacle by imaging the Dot/Icm T4BSS in its native state within intact cells through electron cryotomography. Here we extend our observations by imaging a stabilized mutant that yielded a higher resolution map. We describe for the first time the presence of a well-ordered central channel that opens up into a windowed large (~32 nm wide) secretion chamber with an unusual 13-fold symmetry. We then dissect the complex by matching proteins to densities for many components, including all those with periplasmic domains. The placement of known and predicted structures of individual proteins into the map reveals the architecture of the T4BSS and provides a roadmap for further investigation of this amazing specialized secretion system.

scholarly journals Stable and Oriented Liquid Crystal Droplets Stabilized by Imidazolium Ionic Liquids

Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 6044
Author(s):  
Efthymia Ramou ◽  
Guilherme Rebordão ◽  
Susana I. C. J. Palma ◽  
Ana C. A. Roque
Keyword(s):  
Ionic Liquids ◽  
Liquid Crystal ◽  
Soft Matter ◽  
Sodium Dodecyl ◽  
High Yield ◽  
Molecular Features ◽  
Surface Active ◽  
State Of Matter ◽  
First Time ◽  
Sds Surfactant

Liquid crystals represent a fascinating intermediate state of matter, with dynamic yet organized molecular features and untapped opportunities in sensing. Several works report the use of liquid crystal droplets formed by microfluidics and stabilized by surfactants such as sodium dodecyl sulfate (SDS). In this work, we explore, for the first time, the potential of surface-active ionic liquids of the imidazolium family as surfactants to generate in high yield, stable and oriented liquid crystal droplets. Our results show that [C12MIM][Cl], in particular, yields stable, uniform and monodisperse droplets (diameter 74 ± 6 µm; PDI = 8%) with the liquid crystal in a radial configuration, even when compared with the standard SDS surfactant. These findings reveal an additional application for ionic liquids in the field of soft matter.

scholarly journals Enhancement of the photocatalytic synchronous removal of Cr(vi) and RhB over RP-modified flower-like SnS2

2020 ◽  
Vol 2 (9) ◽  
pp. 4220-4228
Author(s):  
Xue Bai ◽  
Yanyan Du ◽  
Wenhua Xue ◽  
Xiaoyun Hu ◽  
Jun Fan ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
Degradation Mechanism ◽  
Photocatalytic Degradation Mechanism ◽  
First Time

RP/SnS2 nanocomposite as photocatalyst was fabricated for the first time, exhibiting remarkable activity to synchronous removal of Cr(vi) and RhB. The possible pathway of carriers and photocatalytic degradation mechanism was systematically studied.

Proteomic profiling of cell envelope-associated proteins fromStaphylococcus aureus

PROTEOMICS ◽  
2006 ◽  
Vol 6 (5) ◽  
pp. 1530-1549 ◽  
Author(s):  
Christine L. Gatlin ◽  
Rembert Pieper ◽  
Shih-Ting Huang ◽  
Emmanuel Mongodin ◽  
Elizabeth Gebregeorgis ◽  
...  
Keyword(s):  
Cell Envelope ◽  
Proteomic Profiling ◽  
Associated Proteins

scholarly journals β-Glucosidase genes differentially expressed during composting

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Xinyue Zhang ◽  
Bo Ma ◽  
Jiawen Liu ◽  
Xiehui Chen ◽  
Shanshan Li ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Environmental Changes ◽  
Cellulose Degradation ◽  
Degradation Mechanism ◽  
Degradation Process ◽  
Global Scale ◽  
Expression Of Genes ◽  
Glucose Tolerant ◽  
Cooling Phase ◽  
And Function

Abstract Background Cellulose degradation by cellulase is brought about by complex communities of interacting microorganisms, which significantly contribute to the cycling of carbon on a global scale. β-Glucosidase (BGL) is the rate-limiting enzyme in the cellulose degradation process. Thus, analyzing the expression of genes involved in cellulose degradation and regulation of BGL gene expression during composting will improve the understanding of the cellulose degradation mechanism. Based on our previous research, we hypothesized that BGL-producing microbial communities differentially regulate the expression of glucose-tolerant BGL and non-glucose-tolerant BGL to adapt to the changes in cellulose degradation conditions. Results To confirm this hypothesis, the structure and function of functional microbial communities involved in cellulose degradation were investigated by metatranscriptomics and a DNA library search of the GH1 family of BGLs involved in natural and inoculated composting. Under normal conditions, the group of non-glucose-tolerant BGL genes exhibited higher sensitivity to regulation than the glucose-tolerant BGL genes, which was suppressed during the composting process. Compared with the expression of endoglucanase and exoglucanase, the functional microbial communities exhibited a different transcriptional regulation of BGL genes during the cooling phase of natural composting. BGL-producing microbial communities upregulated the expression of glucose-tolerant BGL under carbon catabolite repression due to the increased glucose concentration, whereas the expression of non-glucose-tolerant BGL was suppressed. Conclusion Our results support the hypothesis that the functional microbial communities use multiple strategies of varying effectiveness to regulate the expression of BGL genes to facilitate adaptation to environmental changes.

scholarly journals Microbial Gutta-Percha Degradation Shares Common Steps with Rubber Degradation by Nocardia nova SH22a

2012 ◽  
Vol 79 (4) ◽  
pp. 1140-1149 ◽  
Author(s):  
Quan Luo ◽  
Sebastian Hiessl ◽  
Anja Poehlein ◽  
Alexander Steinbüchel
Keyword(s):  
Plasmid Dna ◽  
Cell Envelope ◽  
Degradation Mechanism ◽  
Degradation Pathways ◽  
Genetic Studies ◽  
Content Type ◽  
Gutta Percha ◽  
Optimized Protocol ◽  
Rubber Degradation

ABSTRACTNocardia novaSH22a, a bacterium capable of degrading gutta-percha (GP) and natural rubber (NR), was used to investigate the GP degradation mechanism and the relations between the GP and NR degradation pathways. For this strain, a protocol of electroporation was systematically optimized, and an efficiency of up to 4.3 × 107CFU per μg of plasmid DNA was achieved. By applying this optimized protocol toN. novaSH22a, a Tn5096-based transposon mutagenesis library of this bacterium was constructed. Among about 12,000 apramycin-resistant transformants, we identified 76 stable mutants defective in GP or NR utilization. Whereas 10 mutants were specifically defective in GP utilization, the growth of the other 66 mutants was affected on both GP and NR. This indicated that the two degradation pathways are quite similar and share many common steps. The larger number of GP-degrading defective mutants could be explained in one of two ways: either (i) the GP pathway is more complex and harbors more specific steps or (ii) the steps for both pathways are almost identical, but in the case of GP degradation there are fewer enzymes involved in each step. The analysis of transposition loci and genetic studies on interesting genes confirmed the crucial role of an α-methylacyl-coenzyme A racemase in the degradation of both GP and NR. We also demonstrated the probable involvement of enzymes participating in oxidoreduction reactions, β-oxidation, and the synthesis of complex cell envelope lipids in the degradation of GP.

scholarly journals Gene Expression Profiling of Corpus luteum Reveals Important Insights about Early Pregnancy in Domestic Sheep

Genes ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 415 ◽  
Author(s):  
Kisun Pokharel ◽  
Jaana Peippo ◽  
Melak Weldenegodguad ◽  
Mervi Honkatukia ◽  
Meng-Hua Li ◽  
...  
Keyword(s):  
Corpus Luteum ◽  
Early Pregnancy ◽  
Ribosomal Proteins ◽  
Embryo Implantation ◽  
Differentially Expressed ◽  
Domestic Sheep ◽  
Preimplantation Stage ◽  
Sialic Acid Binding ◽  
Associated Proteins ◽  
First Time

The majority of pregnancy loss in ruminants occurs during the preimplantation stage, which is thus the most critical period determining reproductive success. Here, we performed a comparative transcriptome study by sequencing total mRNA from corpus luteum (CL) collected during the preimplantation stage of pregnancy in Finnsheep, Texel and F1 crosses. A total of 21,287 genes were expressed in our data. Highly expressed autosomal genes in the CL were associated with biological processes such as progesterone formation (STAR, CYP11A1, and HSD3B1) and embryo implantation (e.g., TIMP1, TIMP2 and TCTP). Among the list of differentially expressed genes, sialic acid-binding immunoglobulin (Ig)-like lectins (SIGLEC3, SIGLEC14, SIGLEC8), ribosomal proteins (RPL17, RPL34, RPS3A, MRPS33) and chemokines (CCL5, CCL24, CXCL13, CXCL9) were upregulated in Finnsheep, while four multidrug resistance-associated proteins (MRPs) were upregulated in Texel ewes. A total of 17 known genes and two uncharacterized non-coding RNAs (ncRNAs) were differentially expressed in breed-wise comparisons owing to the flushing diet effect. The significantly upregulated TXNL1 gene indicated potential for embryonic diapause in Finnsheep and F1. Moreover, we report, for the first time in any species, several genes that are active in the CL during early pregnancy (including TXNL1, SIGLEC14, SIGLEC8, MRP4, and CA5A).

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