Biotechnol Biofuels Bioprod
November 2024
An anaerobic bacterial strain, designated strain M3/9, was isolated from a laboratory-scale biogas fermenter fed with maize silage supplemented with 5 % wheat straw. Cells were straight, non-motile rods, which stained Gram-negative. Optimal growth occurred between 30 and 40°C, at pH 7.
View Article and Find Full Text PDFBiotechnol Biofuels Bioprod
November 2022
Background: Plant cell walls represent the most plentiful renewable organic resource on earth, but due to their heterogeneity, complex structure and partial recalcitrance, their use as biotechnological feedstock is still limited.
Results: In order to identify efficient enzymes for polysaccharide breakdown, we have carried out functional screening of metagenomic fosmid libraries from biogas fermenter microbial communities grown on sugar beet pulp, an arabinan-rich agricultural residue, or other sources containing microbes that efficiently depolymerize polysaccharides, using CPH (chromogenic polysaccharide hydrogel) or ICB (insoluble chromogenic biomass) labeled polysaccharide substrates. Seventy-one depolymerase-encoding genes were identified from 55 active fosmid clones by using Illumina and Sanger sequencing and dbCAN CAZyme (carbohydrate-active enzyme) annotation.
Functional, biochemical, and preliminary structural properties are reported for three glycoside hydrolases of the recently described glycoside hydrolase (GH) family 159. The genes were cloned from the genomic sequences of different strains. This study extends the spectrum of functions of GH159 enzymes.
View Article and Find Full Text PDFAppl Microbiol Biotechnol
February 2022
In this study, we compared the properties and structures of three fungal GH12 enzymes: the strict endoglucanase Bgh12A and the xyloglucanase Xgh12B from Aspergillus cervinus, and the endoglucanase Egh12 from Thielavia terrestris combining activity on linear β-glucan and branched xyloglucan. Egh12 from T. terrestris was produced in Pichia pastoris, purified, and characterized as a thermostable enzyme with maximal activity at 70 ºC and a half-life time of 138 min at 65 °C.
View Article and Find Full Text PDFStrain MD1 is an anaerobic, Gram-stain-negative bacterium isolated from a lab-scale biogas fermenter fed with maize silage. It has a rod-shaped morphology with peritrichously arranged appendages and forms long chains of cells and coccoid structures. The colonies of MD1 were white, circular, slightly convex and had a smooth rim.
View Article and Find Full Text PDFArabinofuranosidases are important accessory enzymes involved in the degradation of arabinose-containing poly- and oligosaccharides. Two arabinofuranosidases from the recently described novel anaerobic cellulolytic bacterium , designated Araf51 and Araf43, were heterologously expressed in and biochemically characterized. Araf51 not only removed arabinose moieties at O-3, O-2 and terminal O-5 positions of arabinose-containing oligosaccharides, but also exhibited exo-β-xylosidase side activity.
View Article and Find Full Text PDFstrain mbf-VZ-132 was isolated from soil in Freising-Weihenstephan (Bavaria, Germany). The 16S rRNA gene sequence showed a 99.9% sequence identity to that of DSM 15410, which was recently reclassified as In this study, we present the draft genome sequence of mbf-VZ-132 based on PacBio sequencing.
View Article and Find Full Text PDFstrain P3M-3 is a strictly anaerobic, halotolerant, organotrophic bacterium of the family that can utilize various plant-derived polysaccharides as its carbon source. The strain was originally isolated from a microbial mat in western Siberia (Russia). In this study, we present the draft genome sequence of P3M-3 based on Illumina paired-end sequencing.
View Article and Find Full Text PDFAn anaerobic bacterial strain, designated MA18, was isolated from a laboratory-scale biogas fermenter fed with maize silage. Cells stained Gram-negative and performed Gram-negative in the KOH test. The peptidoglycan type was found to be A1y-meso-Dpm direct.
View Article and Find Full Text PDFAppl Microbiol Biotechnol
February 2021
The thermostable endo-processive xyloglucanase MtXgh74 from Myceliophthora thermophila was used to study the influence of aromatic amino acids in the catalytic cleft on the mode of action and the ability of enzyme to reduce xyloglucan viscosity. The enzyme derivative Mut I with mutations W64A/W67A in the "negative" subsites of the catalytic cleft resulted in a 5.5-fold increase of the K value.
View Article and Find Full Text PDFMembers of the genera and were speculated to represent indicators reflecting process instability within anaerobic digestion (AD) microbiomes. Therefore, ING2-E5A was isolated from a biogas reactor sample and sequenced on the PacBio and Illumina MiSeq sequencers. Phylogenetic classification positioned the strain ING2-E5A in close proximity to and species (family Dysgonomonadaceae).
View Article and Find Full Text PDFButanol is a platform chemical that is utilized in a wide range of industrial products and is considered a suitable replacement or additive to liquid fuels. So far, it is mainly produced through petrochemical routes. Alternative production routes, for example through biorefinery, are under investigation but are currently not at a market competitive level.
View Article and Find Full Text PDFGenomic studies revealed the glycoside hydrolases of family 48 (GH48) as a powerful marker for the identification of truly cellulolytic bacteria. Here we report an improved method for detecting cellulolytic bacteria in lab-scale biogas fermenters by using GH48 genes as a molecular marker in DNA and RNA samples. We developed a mixture of primers for the specific amplification of a GH48 gene region in a broad range of bacteria.
View Article and Find Full Text PDFBacterial hydrolysis of polysaccharides is an important step for the production of sustainable energy, for example during the conversion of plant biomass to methane-rich biogas. Previously, was identified as cellulolytic key player in thermophilic biogas microbiomes with a great frequency as an accompanying organism. The aim of this study was to physiologically characterize a recently isolated co-culture of and the saccharolytic bacterium from a laboratory-scale biogas fermenter.
View Article and Find Full Text PDFDSM 292 was originally isolated from soil in 1947 due to its ability to produce antibiotics. The low proteolytic properties of strain DSM 292 warrant its examination as a host for heterologous protein production. Here, we report the draft genome sequence of DSM 292 as established by Illumina MiSeq paired-end sequencing.
View Article and Find Full Text PDFIn this work, we succeeded in the isolation of a novel species out of a mesophilically operated biogas fermenter fed with maize silage. Strains GS7-6-2, GS-7K2 and GS-0K3 were isolated from three individual enrichment cultures. 16S rRNA gene sequence comparisons indicated that the isolates had 100 % sequence identity and were most closely related to WN036, with which they shared a 16S rRNA gene sequence similarity of 93.
View Article and Find Full Text PDFCarbohydrate active enzymes are classified in databases based on sequence and structural similarity. However, their function can vary considerably within a similarity-based enzyme family, which makes biochemical characterisation indispensable to unravel their physiological role and to arrive at a meaningful annotation of the corresponding genes. In this study, we biochemically characterised the four related enzymes Tm_Ram106B, Tn_Ram106B, Cb_Ram106B and Ts_Ram106B from the thermophilic bacteria Thermotoga maritima MSB8, Thermotoga neapolitana Z2706-MC24, Caldicellulosiruptor bescii DSM 6725 and Thermoclostridium stercorarium DSM 8532, respectively, as α-L-rhamnosidases.
View Article and Find Full Text PDFIn this work, the isolation and characterization of a novel anaerobic, mesophilic and cellulolytic bacterium is described. Comparative analysis of the almost-complete sequence of the 16S rRNA gene showed that the closest relatives were CSK1 (97.53 %) and DSM 2360 (95.
View Article and Find Full Text PDFIn spite of intensive exploitation of aspergilli for the industrial production of carbohydrases, little is known about hydrolytic enzymes of fungi from the section Cervini. Novel glycoside hydrolases Bgh12A and Xgh12B from Aspergillus cervinus represent examples of divergent activities within one enzyme family and belong to the GH12 phylogenetic subgroup I (endo-(1,4)-β-glucanases) and II (endo-xyloglucanases), respectively. The bgh12A and xgh12B genes were identified in the unsequenced genome of A.
View Article and Find Full Text PDFBiogas plants achieve its highest yield on plant biomass only with the most efficient hydrolysis of cellulose. This is driven by highly specialized hydrolytic microorganisms, which we have analyzed by investigating enrichment strategies for the isolation of cellulolytic bacteria out of a lab-scale biogas fermenter. We compared three different cultivation media as well as two different inoculation materials: Enrichment on filter paper in nylon bags (in sacco) or raw digestate.
View Article and Find Full Text PDFStrain GS7-6-2 was isolated from a mesophilically operated biogas fermenter. The 16S rRNA gene sequence (93.27% identity to WN036) indicated that GS7-6-2 represents a putative novel species within the genus (family ).
View Article and Find Full Text PDFDue to their high secretion capacity, Gram-positive bacteria from the genus Bacillus are important expression hosts for the high-yield production of enzymes in industrial biotechnology; however, to date, strains from only few Bacillus species are used for enzyme production at industrial scale. Herein, we introduce Paenibacillus polymyxa DSM 292, a member of a different genus, as a novel host for secretory protein production. The model gene cel8A from Clostridium thermocellum was chosen as an easily detectable reporter gene with industrial relevance to demonstrate heterologous expression and secretion in P.
View Article and Find Full Text PDFBackground: Increasing the efficiency of enzymatic biomass degradation is crucial for a more economically feasible conversion of abundantly available plant feedstock. Synergistic effects between the enzymes deployed in the hydrolysis of various hemicelluloses have been demonstrated, which can reduce process costs by lowering the amount of enzyme required for the reaction. Xyloglucan is the only major hemicellulose for which no such effects have been described yet.
View Article and Find Full Text PDFBackground: The bioconversion of lignocellulosic biomass in various industrial processes, such as the production of biofuels, requires the degradation of hemicellulose. is a thermophilic bacterium, well known for its outstanding hemicellulose-degrading capability. Its genome comprises about 50 genes for partially still uncharacterised thermostable hemicellulolytic enzymes.
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