Efficient production of sophorose from glucose and its potentially industrial application in cellulase production.

Sophorose is the most effective inducer for cellulase production by Trichoderma reesei. Currently, the biosynthesis of sophorose is very inefficient, resulting in that unavailable for cellulase production in industry. In this study, CoGH1A, a multifunctional thermophilic glycoside hydrolase, was employed for sophorose production.

Application of synthetic biology strategies to promote biosynthesis of fatty acids and their derivatives.

Fatty acids and their derivatives are indispensable biomolecules in all organisms, and can be used as intermediates in the synthesis of pharmaceuticals, biofuels and pesticides, and thus their demand has increased dramatically in recent years. In addition to serving as structural components of cell membranes and metabolic energy, fatty acids and their derivatives can also be used as signal transduction and regulatory bioactive molecules to regulate cell functions. Biosynthesis of fatty acids and their derivatives through microbial catalysis provides green and alternative options to meet the goal.

From methane to value-added bioproducts: microbial metabolism, enzymes, and metabolic engineering.

Methane is abundant in nature, and excessive emissions will cause the greenhouse effect. Methane is also an ideal carbon and energy feedstock for biosynthesis. In the review, the microorganisms, metabolism, and enzymes for methane utilization, and the advances of conversion to value-added bioproducts were summarized.

Co-conversion of lignocellulose-derived glucose, xylose, and aromatics to polyhydroxybutyrate by metabolically engineered Cupriavidus necator.

Utilization of all major components of lignocellulose is essential for biomass biorefining. Glucose, xylose, and lignin-derived aromatics can be generated from cellulose, hemicellulose, and lignin of lignocellulose degradation through pretreatment and hydrolysis. In present work, Cupriavidus necator H16 was engineered to utilize glucose, xylose, p-coumaric acid, and ferulic acid simultaneously by multi-step genetic engineering.

Biosynthesis of value-added bioproducts from hemicellulose of biomass through microbial metabolic engineering.

Hemicellulose is the second most abundant carbohydrate in lignocellulosic biomass and has extensive applications. In conventional biomass refinery, hemicellulose is easily converted to unwanted by-products in pretreatment and therefore can't be fully utilized. The present study aims to summarize the most recent development of lignocellulosic polysaccharide degradation and fully convert it to value-added bioproducts through microbial and enzymatic catalysis.

Microbial redox coenzyme engineering and applications in biosynthesis.

Many biosynthetic processes, either in vivo or in vitro, involve redox reactions catalyzed by oxidoreductases - which depend on coenzymes as electron carriers. Redox balance is regulated mainly by coenzymes NAD(P) and NAD(P)H and is essential for biosynthesis. New techniques for the regulation and regeneration of coenzymes have recently advanced our understanding of, and demonstrated promising applications in, synthetic biology.

The Overexpression of Phasin and Regulator Genes Promoting the Synthesis of Polyhydroxybutyrate in Cupriavidus necator H16 under Nonstress Conditions.

Cupriavidus necator H16 is an ideal strain for polyhydroxybutyrate (PHB) production from CO. Low-oxygen stress can induce PHB synthesis in C. necator H16 while reducing bacterial growth under chemoautotrophic culture.

Wide-bound salt tolerance of the inocula from marine sediment and their specific microbial community.

The microorganisms in marine sediment are promising candidates for the treatment of the saline wastes due to their property of salt tolerance. However, the knowledge about the microbial community and property of the marine sediments is still limited. In the present study, the salt tolerance of the microorganisms in the marine sediment that was collected from a marine fish farm was investigated by being used as inoculum for anaerobic digestion.

Depolymerization and conversion of lignin to value-added bioproducts by microbial and enzymatic catalysis.

Lignin, the most abundant renewable aromatic compound in nature, is an excellent feedstock for value-added bioproducts manufacturing; while the intrinsic heterogeneity and recalcitrance of which hindered the efficient lignin biorefinery and utilization. Compared with chemical processing, bioprocessing with microbial and enzymatic catalysis is a clean and efficient method for lignin depolymerization and conversion. Generally, lignin bioprocessing involves lignin decomposition to lignin-based aromatics via extracellular microbial enzymes and further converted to value-added bioproducts through microbial metabolism.

Metabolic engineering of Cupriavidus necator H16 for improved chemoautotrophic growth and PHB production under oxygen-limiting conditions.

The oxygen-limiting condition promotes the accumulation of ployhydroxybutyrate (PHB) in C. necator H16, while the growth of which is restricted. Under autotrophic culture using carbon dioxide, hydrogen, and oxygen as substrates, the oxygen concentration below 6.

Nitrogen-doped porous carbon from biomass with superior catalytic performance for acetylene hydrochlorination.

Acetylene hydrochlorination is an important aspect of the industrial synthesis of polyvinyl chloride, but it requires a toxic mercury chloride catalyst. Here we report a green, highly efficient and low cost nitrogen-doped soybean meal carbon (SBMC) catalyst obtained from the simple carbonization of biomass soybean meal (SBM) in the presence of zinc chloride. This material exhibits excellent catalytic performance during acetylene hydrochlorination, with an initial acetylene conversion greater than 99% and 98% selectivity for vinyl chloride at 200 °C over 110 h.

Heteroexpression of - improved switchgrass biomass yield and feedstock quality by repression of .

Background: Switchgrass ( L.), a C perennial grass, has been recognized as one of the most potentially important lignocellulose biofuel crops. MicroRNA319 (miR319) plays a key role in plant development, abiotic resistance, and cell wall biosynthesis by repressing expression of its target genes.

Corrosion behavior and mechanism of carbon steel influenced by interior deposit microflora of an in-service pipeline.

Investigation of carbon steel corrosion influenced by in-situ microbial communities can provide reliable information about microbiologically influenced corrosion (MIC) in the oil and gas field. Here, we investigated the 90-day corrosion behavior of Q235 carbon steel influenced by interior deposit microflora of an in-service pipeline using open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS). Linear sweep voltammetry (LSV), 16S rRNA gene sequencing, and surface analysis were used to comprehensively analyze the corrosion mechanisms.

The mutual influence between corrosion and the surrounding soil microbial communities of buried petroleum pipelines.

Buried petroleum pipeline corrosion and leaks cause inevitable changes in the microbial communities of the surrounding soils. In addition, soils with different microbial communities can make different contributions to buried pipeline corrosion. Three kinds of soil samples of buried petroleum pipelines under different corrosion and petroleum contamination conditions were collected from the Shengli Oilfield of China to investigate the mutual influence between corrosion and the microbial communities of the surrounding soil.

The extracellular endo-β-1,4-xylanase with multidomain from the extreme thermophile is specific for insoluble xylan degradation.

Background: The extremely thermophilic bacterium can degrade and metabolize untreated lignocellulosic biomass containing xylan. The mechanism of the bacterium for degradation of insoluble xylan in untreated biomass has not been revealed.

Results: In the present study, the only annotated extracellular endo-β-1,4-xylanase (Xyn10B) with multidomain structures in genome was biochemically characterized.

Simultaneous biosynthesis of ()-acetoin and ethylene glycol from D-xylose through metabolic engineering.

()-acetoin is a four-carbon platform compound used as the precursor for synthesizing novel optically active materials. Ethylene glycol (EG) is a large-volume two-carbon commodity chemical used as the anti-freezing agent and building-block molecule for various polymers. Currently established microbial fermentation processes for converting monosaccharides to either ()-acetoin or EG are plagued by the formation of undesirable by-products.

Sequential processing with fermentative Caldicellulosiruptor kronotskyensis and chemolithoautotrophic Cupriavidus necator for converting rice straw and CO to polyhydroxybutyrate.

Unpretreated rice straw was fermented by the extremely thermophilic bacterium Caldicellulosiruptor kronotskyensis, generating solubilized carbohydrates, organic acids, lignin-derived aromatics, H , and CO , which were subsequently used to produce polyhydroxybutyrate (PHB) by the chemolithoautotrophic bacterium Cupriavidus necator. The fermented liquid significantly enhanced the growth of C. necator, leading to a five-fold cell biomass yield, and a nine-fold PHB yield compared to what was obtained from conventional mineral media.

Conversion of cellulose and hemicellulose of biomass simultaneously to acetoin by thermophilic simultaneous saccharification and fermentation.

Background: Acetoin (3-hydroxy-2-butanone), the precursor of biofuel 2,3-butanediol, is an important bio-based platform chemical with wide applications. Fermenting the low-cost and renewable plant biomass is undoubtedly a promising strategy for acetoin production. Isothermal simultaneous saccharification and fermentation (SSF) is regarded as an efficient method for bioconversion of lignocellulosic biomass, in which the temperature optima fitting for both lignocellulose-degrading enzymes and microbial strains.

Enzymatic Mechanism for Arabinan Degradation and Transport in the Thermophilic Bacterium Caldanaerobius polysaccharolyticus.

The plant cell wall polysaccharide arabinan provides an important supply of arabinose, and unraveling arabinan-degrading strategies by microbes is important for understanding its use as a source of energy. Here, we explored the arabinan-degrading enzymes in the thermophilic bacterium and identified a gene cluster encoding two glycoside hydrolase (GH) family 51 α-l-arabinofuranosidases (CpAbf51A, CpAbf51B), a GH43 endoarabinanase (CpAbn43A), a GH27 β-l-arabinopyranosidase (CpAbp27A), and two GH127 β-l-arabinofuranosidases (CpAbf127A, CpAbf127B). The genes were expressed as recombinant proteins, and the functions of the purified proteins were determined with -nitrophenyl (NP)-linked sugars and naturally occurring pectin structural elements as the substrates.

A thermophilic cell-free cascade enzymatic reaction for acetoin synthesis from pyruvate.

Acetoin (3-hydroxy-2-butanone) is an important bio-based platform chemical with wide applications. In vitro enzyme catalysed synthesis exhibits great feasibility in the production of chemicals with high purity. In the present work, a synthetic pathway involving a two-step continuous reaction was constructed in vitro for acetoin production from pyruvate at improved temperature.

Changes in composition, cellulose degradability and biochemical methane potential of Miscanthus species during the growing season.

The composition, cellulose degradability and biochemical methane potential (BMP) of M. sinensis, M. floridulus, Miscanthus×giganteus and M.

Ancillary contributions of heterologous biotin protein ligase and carbonic anhydrase for CO incorporation into 3-hydroxypropionate by metabolically engineered Pyrococcus furiosus.

Acetyl-Coenzyme A carboxylase (ACC), malonyl-CoA reductase (MCR), and malonic semialdehyde reductase (MRS) convert HCO and acetyl-CoA into 3-hydroxypropionate (3HP) in the 3-hydroxypropionate/4-hydroxybutyrate carbon fixation cycle resident in the extremely thermoacidophilic archaeon Metallosphaera sedula. These three enzymes, when introduced into the hyperthermophilic archaeon Pyrococcus furiosus, enable production of 3HP from maltose and CO . Sub-optimal function of ACC was hypothesized to be limiting for production of 3HP, so accessory enzymes carbonic anhydrase (CA) and biotin protein ligase (BPL) from M.

Reaction kinetic analysis of the 3-hydroxypropionate/4-hydroxybutyrate CO fixation cycle in extremely thermoacidophilic archaea.

The 3-hydroxypropionate/4-hydroxybutyrate (3HP/4HB) cycle fixes CO in extremely thermoacidophilic archaea and holds promise for metabolic engineering because of its thermostability and potentially rapid pathway kinetics. A reaction kinetics model was developed to examine the biological and biotechnological attributes of the 3HP/4HB cycle as it operates in Metallosphaera sedula, based on previous information as well as on kinetic parameters determined here for recombinant versions of five of the cycle enzymes (malonyl-CoA/succinyl-CoA reductase, 3-hydroxypropionyl-CoA synthetase, 3-hydroxypropionyl-CoA dehydratase, acryloyl-CoA reductase, and succinic semialdehyde reductase). The model correctly predicted previously observed features of the cycle: the 35-65% split of carbon flux through the acetyl-CoA and succinate branches, the high abundance and relative ratio of acetyl-CoA/propionyl-CoA carboxylase (ACC) and MCR, and the significance of ACC and hydroxybutyryl-CoA synthetase (HBCS) as regulated control points for the cycle.

A multifunctional thermophilic glycoside hydrolase from Caldicellulosiruptor owensensis with potential applications in production of biofuels and biochemicals.

Background: Thermophilic enzymes have attracted much attention for their advantages of high reaction velocity, exceptional thermostability, and decreased risk of contamination. Exploring efficient thermophilic glycoside hydrolases will accelerate the industrialization of biofuels and biochemicals.

Results: A multifunctional glycoside hydrolase (GH) CoGH1A, belonging to GH1 family with high activities of β-d-glucosidase, exoglucanase, β-d-xylosidase, β-d-galactosidase, and transgalactosylation, was cloned and expressed from the extremely thermophilic bacterium Caldicellulosiruptor owensensis.

Biochemical characterization of extra- and intracellular endoxylanse from thermophilic bacterium Caldicellulosiruptor kronotskyensis.

Caldicellulosiruptor kronotskyensis grows on lignocellulosic biomass by the catalysis of intrinsic glycoside hydrolase, and has potential application for consolidated bioprocessing. In current study, two predicted extra- (Xyn10A) and intracellular (Xyn10B) xylanase from C. kronotskyensis were comparatively characterized.