In order to learn the enzymatic hydrolysis characteristics of steam-explosion pretreated corn straw by cellulase, the effects of substrate concentration, cellulase concentration and temperature were determined. The kinetics of the hydrolysis reaction could be described with the Michealis-Menten equation, and the hydrolysis reaction obeyed the classical first-order reaction rate in the first three hours. In the condition of 45 degrees C and pH 5.0 and the stirring rate 120 r/min, the Michealis constant (Km) and maximum rate (Vm) for 1.2 FPU/mL of cellulase were 11.71 g/L and 1.5 g/(L x h). The kinetic model, including the parameters such as substrate concentration, enzymatic concentration and temperature, was suit for the hydrolysis reaction under the temperature range from 30 degrees C-50 degrees C.
Catalysis ; Cellulase ; chemistry ; Hydrolysis ; Kinetics ; Plant Stems ; Steam ; Zea mays

The products concentrations in traditional acetone-butanol (AB) fermentation are too low that large amount of energy has to be consumed in the distillation and product recovery process. Aiming at direct utilization of the fermentation products, in this study, optimization of property-improved biodiesel manufacturing process coupled with AB extractive fermentation was conducted, under the condition of using the biodiesel originated from waste cooking oil as the extractant and high concentrated corn flour medium. The effect of biodiesel/broth volume ratio, waste supernatant recycle ratio, and electronic carrier addition on the major process performance index was carefully investigated. Under the optimized condition, the biodiesel quality was improved with the cetane value increased from 51.4 to 54.4; "actual butanol yield" reached to a level of 18%, and waste supernatant recycle ratio exceeded 50%. In this way, elimination of energy-consuming product recovery process and realization of "energy-saving & waste minimization" industrial production target advocated by the state government, could be potentially expected.
Bioelectric Energy Sources ; Butanols ; chemistry ; Fermentation ; Gasoline ; Zea mays ; metabolism

Biorefinery of chemicals from straw is an effective approach to alleviate the environmental pollution caused by straw burning. In this paper, we prepared gellan gum immobilized Lactobacillus bulgaricus T15 gel beads (LA-GAGR-T15 gel beads), characterized their properties, and established a continuous cell recycle fermentation process for D-lactate (D-LA) production using the LA-GAGR-T15 gel beads. The fracture stress of LA-GAGR-T15 gel beads was (91.68±0.11) kPa, which was 125.12% higher than that of the calcium alginate immobilized T15 gel beads (calcium alginate-T15 gel beads). This indicated that the strength of LA-GAGR-T15 gel beads was stronger, and the strain was less likely to leak out. The average D-LA production was (72.90±2.79) g/L after fermentation for ten recycles (720 h) using LA-GAGR-T15 gel beads as the starting strain and glucose as the substrate, which was 33.85% higher than that of calcium alginate-T15 gel beads and 37.70% higher than that of free T15. Subsequently, glucose was replaced by enzymatically hydrolyzed corn straw and fermented for ten recycles (240 h) using LA-GAGR-T15 gel beads. The yield of D-LA reached (1.74±0.79) g/(L·h), which was much higher than that of using free bacteria. The wear rate of gel beads was less than 5% after ten recycles, which indicated that LA-GAGR is a good carrier for cell immobilization and can be widely used in industrial fermentation. This study provides basic data for the industrial production of D-LA using cell-recycled fermentation, and provides a new way for the biorefinery of D-LA from corn straw.
Fermentation ; Lactobacillus delbrueckii ; Zea mays ; Lactic Acid ; Alginates/chemistry* ; Glucose

In order to improve ferment efficiency of biocontrol agent Burkholderia pyrrocinia JK-SH007, the fermentation conditions of this strain were optimized. The optimal fermentation conditions were corn steep liquor (13.88 g/L) and glucose (3.37 g/L) by screening test, steepest ascent experiments and response surface analysis. The results showed that the cell density of JK-SH007 (1.18 x 10(9) CFU/mL) increased 1.35 times than before, and there was a 28.84% increase in antifungal activity.
Biological Control Agents ; Burkholderiaceae ; growth & development ; Fermentation ; Glucose ; chemistry ; Surface Properties ; Zea mays ; chemistry

Fast pyrolysis experiments of corn stalk were performed to investigate the optimal pyrolysis conditions of temperature and bed material for maximum bio-oil production under flue gas atmosphere. Under the optimized pyrolysis conditions, furfural residue, xylose residue and kelp seaweed were pyrolyzed to examine their yield distributions of products, and the physical characteristics of bio-oil were studied. The best flow rate of the flue gas at selected temperature is obtained, and the pyrolysis temperature at 500 degrees C and dolomite as bed material could give a maximum bio-oil yield. The highest bio-oil yield of 43.3% (W/W) was achieved from corn stalk under the optimal conditions. Two main fractions were recovered from the stratified bio-oils: light oils and heavy oils. The physical properties of heavy oils from all feedstocks varied little. The calorific values of heavy oils were much higher than that of light oils. The pyrolysis gas could be used as a gaseous fuel due to a relatively high calorific value of 6.5-8.5 MJ/m3.
Biofuels ; Biomass ; Bioreactors ; Furaldehyde ; chemistry ; Hot Temperature ; Kelp ; Temperature ; Xylose ; chemistry ; Zea mays

To further develop the methods to remotely sense the biochemical content of plant canopies, we report the results of an experiment to estimate the concentrations of three biochemical variables of corn, i.e., nitrogen (N), crude fat (EE) and crude fiber (CF) concentrations, by spectral reflectance and the first derivative reflectance at fresh leaf scale. The correlations between spectral reflectance and the first derivative transformation and three biochemical variables were analyzed, and a set of estimation models were established using curve-fitting analyses. Coefficient of determination (R2), root mean square error (RMSE) and relative error of prediction (REP) of estimation models were calculated for the model quality evaluations, and the possible optimum estimation models of three biochemical variables were proposed, with R2 being 0.891, 0.698 and 0.480 for the estimation models of N, EE and CF concentrations, respectively. The results also indicate that using the first derivative reflectance was better than using raw spectral reflectance for all three biochemical variables estimation, and that the first derivative reflectances at 759 nm, 1954 nm and 2370 nm were most suitable to develop the estimation models of N, EE and CF concentrations, respectively. In addition, the high correlation coefficients of the theoretical and the measured biochemical parameters were obtained, especially for nitrogen (r=0.948).
Lipids ; analysis ; Nitrogen ; analysis ; Plant Leaves ; chemistry ; Spectrum Analysis ; Zea mays ; chemistry

Reversible phosphorylation plays a crucial role in regulating protein activities and functions. Sexual reproduction directly affects yield of most agricultural crops. As the male reproductive organ, anther generates microspores (pollen), delivering gametes (sperms) to complete double fertilization in higher plants. Here, we took the advantage of Nano UHPLC-MS/MS to analyze maize (Zea mays, B73) early anthers at proteomic and phosphoproteomic levels, to explore the protein and phosphorylation modification regulatory networks controlling maize anther development. Our proteomic analysis identified 3 016 unique peptides, belonging to 1 032 maize proteins. MapMan analysis revealed variously potential proteins associated with maize anther development, such as receptor-like kinases (GRMZM2G082823_P01 and GRMZM5G805485_P01). Using phospho-peptides enriched by TiO2 affinity chromatography, our phosphoproteomic analysis detected 257 phospho-peptides from 210 phosphoproteins, discovering 223 phosphosites. Compared to the 86 maize phosphoproteins collected in the Plant Protein Phosphorylation Data Base (P3DB), we found that 203 phosphoproteins and 218 phosphosites were not revealed before. Further bioinformatics analysis revealed that phosphorylation of 14-3-3 proteins, kinases, phosphatases, transcription factors, cell cycle and chromatin structure related proteins might play important roles in regulating normal anther development in maize. Our findings not only enlarged the maize phosphoproteome data, but also provided information for analyzing the molecular mechanism controlling maize anther development at genetic and biochemical levels.
Crops, Agricultural ; chemistry ; Phosphoproteins ; chemistry ; Phosphorylation ; Plant Proteins ; chemistry ; Pollen ; chemistry ; Proteome ; Tandem Mass Spectrometry ; Zea mays ; chemistry

The changes of kernel nutritive components and seed vigor in F1 seeds of sh2 sweet corn during seed development stage were investigated and the relationships between them were analyzed by time series regression (TSR) analysis. The results show that total soluble sugar and reducing sugar contents gradually declined, while starch and soluble protein contents increased throughout the seed development stages. Germination percentage, energy of germination, germination index and vigor index gradually increased along with seed development and reached the highest levels at 38 d after pollination (DAP). The TSR showed that, during 14 to 42 DAP, total soluble sugar content was independent of the vigor parameters determined in present experiment, while the reducing sugar content had a significant effect on seed vigor. TSR equations between seed reducing sugar and seed vigor were also developed. There were negative correlations between the seed reducing sugar content and the germination percentage, energy of germination, germination index and vigor index, respectively. It is suggested that the seed germination, energy of germination, germination index and vigor index could be predicted by the content of reducing sugar in sweet corn seeds during seed development stages.
Carbohydrates ; analysis ; Germination ; Seeds ; growth & development ; Zea mays ; chemistry ; growth & development

To increase the integral economic effectiveness, biorefineries of lignocellulosic materials should not only utilize carbohydrates hydrolyzed from cellulose and hemicellulose but also use lignin. We used steam-exploded corn stalk as raw materials and optimized the temperature and alkali concentration in the lignin extraction process to obtain lignin liquor with higher yield and purity. Then the concentrated lignin liquor was used directly to substitute phenol for phenolic foam preparation and the performances of phenolic foam were characterized by microscopic structure analysis, FTIR, compression strength and thermal conductivity detection. The results indicated that, when steam-exploded corn stalk was extracted at 120 degrees C for 2 h by 1% NaOH with a solid to liquid ratio of 1:10, the extraction yield of lignin was 79.67%. The phenolic foam prepared from the concentrated lignin liquor showed higher apparent density and compression strength with the increasing substitution rate of lignin liquor. However, there were not significant differences of thermal conductivity and flame retardant properties by the addition of lignin, which meant that the phenolic foam substituted by lignin liquor was approved for commercial application. This study, which uses alkali-extracted lignin liquor directly for phenolic foam preparation, provides a relatively simple way for utilization of lignin and finally increases the overall commercial operability ofa lignocellulosic biorefinery derived by steam explosion.
Biotechnology ; methods ; Chemical Fractionation ; Hot Temperature ; Lignin ; chemistry ; Phenols ; chemistry ; Plant Stems ; chemistry ; Steam ; Zea mays ; chemistry

Butanol production from corn stover hydrolysates (CSH) with in-situ liquid-liquid extraction was studied to enhance the production and reduce the fermentation cost. Oleyl alcohol was selected as the suitable solvent and added at the initial fermentation time with the ratio of 1:1 (oleyl alcohol: fermentation broth, V/V). Under this condition, butanol and ABE from CSH with 32.1 g/L total sugars were 3.28 and 4.72 g/L, which were 958.1% and 742.9% higher than those of the controls, respectively. Butanol and ABE production from CSH of 49.7 g/L total sugars after detoxification by ion exchange resin D301 coupled with extraction fermentation were 10.34 g/L and 14.72 g/L with an ABE yield of 0.31 g/g (g ABE/g utilized sugar), which were equal to those of glucose and xylose mixture fermentation. The detoxification and extraction fermentation technology of cellulosic butanol production would provide a crucial technical support to the industrialized production of cellulosic butanol.
Butanols ; isolation & purification ; metabolism ; Fatty Alcohols ; chemistry ; Fermentation ; Liquid-Liquid Extraction ; methods ; Plant Stems ; chemistry ; Zea mays ; chemistry