cellulase and gluconic-acid

A system for itaconic acid synthesis from cellulose by Neurospora crassa was established, resulting in the highest yield of itaconic acid was 354.08 + 35.99 mg/L. Meanwhile, cellulase activity increased significantly, without any strain modifications for improved cellulase production. Multi-omics analyses showed that itaconic acid synthesis reduced energy production, leading to decreases in trehalose, cell wall, fatty acids synthesis and downregulations in MAPK signaling pathway, cell cycle and meiosis. More importantly, the low-energy environment enhanced the energy-efficient cellobionic acid/gluconic acid pathway, and the cellulase composition also changed significantly, manifested as the up-regulation of LPMOs and the down-regulation of β-glucosidases. Enhancing LPMOs-cellobionic acid/gluconic acid system has the potential to reduce energy consumption of the consolidated bioprocessing. These findings offer an overview of resource allocations by N. crassa in response to itaconic acid synthesis and highlight a series of intriguing connections between itaconic acid synthesis and cellulase synthesis in consolidated bioprocessing.

Topics: Cellulase; Cellulases; Cellulose; Neurospora crassa

The production of sodium gluconate by enzymatic catalysis of delignified corn cob residue (DCCR) hydrolysate was studied. Penicillium oxalicum I1-13 was used for the production of cellulase with high β-glucosidase activity. A fed-batch saccharification process was developed to obtain high yields of glucose. At the end of hydrolysis, the concentration of glucose reached 145.80g/L. Glucose oxidase and catalase were co-immobilized to catalyze DCCR hydrolysate to produce sodium gluconate. Under the optimum conditions, 166.87g/L sodium gluconate was obtained after 56h of reaction, with a yield of 98.24%. The immobilized enzymes could still maintain more than 60% of the activity after repeated use for 6 times. This study provides a potential route for the production of valuable chemicals by enzymatic conversion of lignocellulosic materials.

Topics: Catalase; Cellulase; Gluconates; Glucose Oxidase; Hydrolysis; Zea mays

The economics driving biorefinery development requires high value-added products such as cellobiose for financial feasibility. This research describes a simple technology for increasing cellobiose yields during lignocellulosic hydrolysis. The yield of cellobiose produced during cellulose hydrolysis was maximized by modification of reaction conditions. The addition of an inhibitor from the group that includes glucose oxidase, gluconolactone, and gluconic acid during cellulase hydrolysis of cellulose increased the amount of cellobiose produced. The optimal conditions for cellobiose production were determined for four factors; reaction time, cellulase concentration, cellulose concentration, and inhibitor concentration using a Box-Behnken experimental design. Gluconolactone in the cellulase system resulted in the greatest production of cellobiose (31.2%) from cellulose. The yield of cellobiose was 23.7% with glucose oxidase, similar to 21.9% with gluconic acid.

Topics: Analysis of Variance; Biomass; Cellobiose; Cellulase; Cellulose; Enzyme Inhibitors; Gluconates; Glucose Oxidase; Hydrolysis; Kinetics; Lactones; Lignin; Trichoderma

Understanding the biochemical mechanisms by which plants respond to microbial infection is a fundamental goal of plant science. Extracellular dermal glycoproteins (EDGPs) are widely expressed in plant tissues and have been implicated in plant defense responses. Although EDGPs are known to interact with fungal proteins, the downstream effects of these interactions are poorly understood. To gain insight into these phenomena, we used tobacco floral nectar as a model system to identify a mechanism by which the EDGP known as Nectarin IV (NEC4) functions as pathogen surveillance molecule. Our data demonstrates that the interaction of NEC4 with a fungal endoglucanase (XEG) promotes the catalytic activity of Nectarin V (NEC5), which catalyzes the conversion of glucose and molecular oxygen to gluconic acid and H(2)O(2). Significantly enhanced NEC5 activity was observed when XEG was added to nectar or nectarin solutions that contain NEC4. This response was also observed when the purified NEC4:XEG complex was added to NEC4-depleted nectarin solutions, which did not respond to XEG alone. These results indicate that formation of the NEC4:XEG complex is a key step leading to induction of NEC5 activity in floral nectar, resulting in an increase in concentrations of reactive oxygen species (ROS), which are known to inhibit microbial growth directly and activate signal transduction pathways that induce innate immunity responses in the plant.

Topics: Cellulase; Fungal Proteins; Gene Expression Regulation, Plant; Glucans; Gluconates; Glucose Oxidase; Glycoproteins; Nicotiana; Plant Nectar; Plant Proteins; Reactive Oxygen Species; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Xylans