Sustainable production of 2,3,5,6-Tetramethylpyrazine at high titer in engineered Corynebacterium glutamicum.

Unlabelled: The industrial amino acid production workhorse, Corynebacterium glutamicum naturally produces low levels of 2,3,5,6-tetramethylpyrazine (TMP), a valuable flavor, fragrance, and commodity chemical. Here, we demonstrate TMP production (∼0.8 g L-1) in C.

Evaluation of engineered low-lignin poplar for conversion into advanced bioproducts.

Background: Lignocellulosic resources are promising feedstocks for the manufacture of bio-based products and bioenergy. However, the inherent recalcitrance of biomass to conversion into simple sugars currently hinders the deployment of advanced bioproducts at large scale. Lignin is a primary contributor to biomass recalcitrance as it protects cell wall polysaccharides from degradation and can inhibit hydrolytic enzymes via non-productive adsorption.

Renewable Schiff-Base Ionic Liquids for Lignocellulosic Biomass Pretreatment.

Growing interest in sustainable sources of chemicals and energy from renewable and reliable sources has stimulated the design and synthesis of renewable Schiff-base (iminium) ionic liquids (ILs) to replace fossil-derived ILs. In this study, we report on the synthesis of three unique iminium-acetate ILs from lignin-derived aldehyde for a sustainable “future” lignocellulosic biorefinery. The synthesized ILs contained only imines or imines along with amines in their structure; the ILs with only imines group exhibited better pretreatment efficacy, achieving >89% sugar release.

Engineering sorghum for higher 4-hydroxybenzoic acid content.

Engineering bioenergy crops to accumulate coproducts can increase the value of lignocellulosic biomass and enable a sustainable bioeconomy. In this study, we engineered sorghum with a bacterial gene encoding a chorismate pyruvate-lyase () to reroute the plastidial pool of chorismate from the shikimate pathway into the valuable compound 4-hydroxybenzoic acid (4-HBA). A gene encoding a feedback-resistant version of 3-deoxy-d-arabino-heptulonate-7-phosphate synthase () was also introduced in an attempt to increase the carbon flux through the shikimate pathway.

Overexpression of the rice BAHD acyltransferase AT10 increases xylan-bound p-coumarate and reduces lignin in Sorghum bicolor.

Background: The development of bioenergy crops with reduced recalcitrance to enzymatic degradation represents an important challenge to enable the sustainable production of advanced biofuels and bioproducts. Biomass recalcitrance is partly attributed to the complex structure of plant cell walls inside which cellulose microfibrils are protected by a network of hemicellulosic xylan chains that crosslink with each other or with lignin via ferulate (FA) bridges. Overexpression of the rice acyltransferase OsAT10 is an effective bioengineering strategy to lower the amount of FA involved in the formation of cell wall crosslinks and thereby reduce cell wall recalcitrance.

Agrobacterium-mediated transient transformation of sorghum leaves for accelerating functional genomics and genome editing studies.

Objectives: Sorghum is one of the most recalcitrant species for transformation. Considering the time and effort required for stable transformation in sorghum, establishing a transient system to screen the efficiency and full functionality of vector constructs is highly desirable.

Results: Here, we report an Agrobacterium-mediated transient transformation assay with intact sorghum leaves using green fluorescent protein as marker.

Rhizobacteria Mediate the Phytotoxicity of a Range of Biorefinery-Relevant Compounds.

Advances in engineering biology have expanded the list of renewable compounds that can be produced at scale via biological routes from plant biomass. In most cases, these chemical products have not been evaluated for effects on biological systems, defined in the present study as bioactivity, that may be relevant to their manufacture. For sustainable chemical and fuel production, the industry needs to transition from fossil to renewable carbon sources, resulting in unprecedented expansion in the production and environmental distribution of chemicals used in biomanufacturing.

The Three Members of the Arabidopsis Glycosyltransferase Family 92 are Functional β-1,4-Galactan Synthases.

Pectin is a major component of primary cell walls and performs a plethora of functions crucial for plant growth, development and plant-defense responses. Despite the importance of pectic polysaccharides their biosynthesis is poorly understood. Several genes have been implicated in pectin biosynthesis by mutant analysis, but biochemical activity has been shown for very few.

Overexpression of a rice BAHD acyltransferase gene in switchgrass (Panicum virgatum L.) enhances saccharification.

Background: Switchgrass (Panicum virgatum L.) is a promising bioenergy feedstock because it can be grown on marginal land and produces abundant biomass. Recalcitrance of the lignocellulosic components of the switchgrass cell wall to enzymatic degradation into simple sugars impedes efficient biofuel production.

Comparative metabolic profiling of vetiver (Chrysopogon zizanioides) and maize (Zea mays) under lead stress.

Lead (Pb) contamination of residential soils in United States is attributed to use of Pb based paints prior to 1978 and their deterioration and accumulation in surface soils. Exposure to Pb due to ingestion and inhalation of Pb laden soil and dust causes neurological disorders, renal disorders, developmental and behavioral problems, particularly in children under the age of six. Vetiver grass is one of the leading choices for Pb remediation due to its ability to hyperaccumulate Pb, in addition to high biomass.

Bifunctional glycosyltransferases catalyze both extension and termination of pectic galactan oligosaccharides.

Pectins are the most complex polysaccharides of the plant cell wall. Based on the number of methylations, acetylations and glycosidic linkages present in their structures, it is estimated that up to 67 transferase activities are involved in pectin biosynthesis. Pectic galactans constitute a major part of pectin in the form of side-chains of rhamnogalacturonan-I.

Structural Characterization of Mannan Cell Wall Polysaccharides in Plants Using PACE.

Plant cell wall polysaccharides are notoriously difficult to analyze, and most methods require expensive equipment, skilled operators, and large amounts of purified material. Here, we describe a simple method for gaining detailed polysaccharide structural information, including resolution of structural isomers. For polysaccharide analysis by gel electrophoresis (PACE), plant cell wall material is hydrolyzed with glycosyl hydrolases specific to the polysaccharide of interest (e.

New LC-MS/MS Method for the Analysis of Allura Red Level in Takeaway Chinese Dishes and Urine of an Adult Chinese Population.

Allura red is a widely used synthetic food dye. In this study, we developed and validated a LC-MS/MS method for the quantification of allura red in three popular takeaway Chinese dishes (braised pork, soy sauce chicken, sweet and sour pork) and human urine samples. High levels of allura red ranging from 2.

Identification of Biochemical Pathways Associated with Lead Tolerance and Detoxification in Chrysopogon zizanioides L. Nash (Vetiver) by Metabolic Profiling.

Lead (Pb) is a major urban pollutant, due to deteriorating lead-based paint in houses built before 1978. Phytoremediation is an inexpensive and effective technique for remediation of Pb-contaminated homes. Vetiver (Chrysopogon zizanioides), a noninvasive, fast-growing grass with high biomass, can tolerate and accumulate large quantities of Pb in its tissues.

Integrated metabolomic and proteomic approaches dissect the effect of metal-resistant bacteria on maize biomass and copper uptake.

Marginal soils arise due to various industrial and agricultural practices reducing crop productivity. Pseudomonas sp. TLC 6-6.