The efficient production of lignocellulolytic enzyme systems is an important support for large-scale biorefinery of plant biomass. On-site production of lignocellulolytic enzymes could increase the economic benefits of the process by lowering the cost of enzyme usage. Penicillium species are commonly found lignocellulose-degrading fungi in nature, and have been used for industrial production of cellulase preparations due to their abilities to secrete complete and well-balanced lignocellulolytic enzyme systems. Here, we introduce the reported Penicillium species for cellulase production, summarize the characteristics of their enzymes, and describe the strategies of strain engineering for improving the production and performance of lignocellulolytic enzymes. We also review the progress in fermentation process optimization regarding the on-site production of lignocellulolytic enzymes using Penicillium species, and suggest prospect of future work from the perspective of building a "sugar platform" for the biorefinery of lignocellulosic biomass.
Biomass ; Cellulase/metabolism* ; Fermentation ; Fungi/metabolism* ; Lignin/metabolism* ; Penicillium

China has abundant available marginal land that can be used for cultivation of lignocellulosic energy plants. Saccharum arundinaceum Retz. is a potential energy crop with both high biomass yield and low soil fertility requirements. It can be planted widely as cellulosic ethanol feedstock in southern China. In the present work Saccharum arundinaceum was pretreated by liquid ammonia treatment (LAT) to overcome biomass recalcitrance, followed by enzymatic hydrolysis. The monosaccharide contents (glucose, xylose, and arabinose) of the enzymatic hydrolysate were determined by high performance liquid chromatography. Experimental results show that the optimal LAT pretreatment conditions were 130 0C, 2:1 (W/W) ammonia to biomass ratio, 80% moisture content (dry weight basis) and 5 min residence time. Approximately 69.34% glucan and 82.60% xylan were converted after 72 h enzymatic hydrolysis at 1% glucan loading using 15 FPU/(g of glucan) of cellulase. The yields of glucose and xylose were 573% and 1 056% higher than those of the untreated biomass, and the LAT-pretreated substrates obtained an 8-fold higher of total monosaccharide yield than untreated substrates. LAT pretreatment was an effective to increase the enzymatic digestibility of Saccharum arundinaceum compared to acid impregnated steam explosion and similar to that of acid treatment and ammonia fiber expansion treatment.
Ammonia ; chemistry ; Cellulase ; metabolism ; Ethanol ; metabolism ; Fermentation ; Hydrolysis ; Monosaccharides ; metabolism ; Saccharum ; chemistry ; metabolism

We studied the alteration of the maize straw apoplast proteins in the process of preservation, and analyzed the effects of apoplast proteins on Penicillum expansum cellulase activities. The results show that: the extractable apoplast proteins are gradually decreased during the preservation of maize straw. Meanwhile, their synergistic effects on P. expensum cellulose are also attenuated. The apoplast proteins extracted from fresh maize straw possess endogenous EG activities, which is unstable and completely vanished after 6 months preservation. The apoplast proteins from the preserved straw exhibit significant synergistic effect on FPA, cotton lyase and beta-glucosidase. The maximal synergistic values are 95.32%, 102.06% and 96.6%, respectively. But interestingly, they inhibit the CMCase activity (max. 49.52%). Apoplast proteins show distinctive synergy with betaG and EG, but have no effect on CBH activity. After eliminating the effect of endogenous EG, the apoplast proteins from fresh maize straw have enhanced synergistic or inhibiting effects on FPA, Cotton lyase, betaG and CMCase than those extracted from the preserved straw. Based on our observation, the apoplast proteins play important roles in regulating the cellulase activities. The detailed analysis of the related mechanisms will greatly benefit the studies of the natural biomaterials hydrolysis.
Cellulase ; metabolism ; Penicillium ; enzymology ; Plant Proteins ; metabolism ; Plant Stems ; metabolism ; Zea mays ; metabolism

Ferulic acid esterase (FAE) was used to hydrolyze feruloyl ester linkages between hemicellulose and lignin in natural lignocellulose, and the possibility of FAE accelerating cellulase to hydrolyze steam-exploded rice straw by breaking covalent linkages was studied. When the dosage of FAE was 240 mu/g substrate, the cellulose conversion rate and the weight-loss rate of insoluble substrate at 72 h were respectively 32.00% and 32.77%, more than without using FAE; Cellulose conversion rate and the weight-loss rate of insoluble substrate were respectively 29.85% and 32.48% with FAE (300 mu/g substrate) processing time of 120 min. By comparison of the accessibility and FT-IR spectra of lignocellulosic material treated by different enzyme methods, it indicated that FAE hydrolyzed some ester bonds within it, and improved the accessibility by over 50%. It is concluded that FAE and cellulase have great synergistic effect, and FAE can help cellulase hydrolyze natural lignocellulose and enhance hydrolytic efficiency.
Carboxylic Ester Hydrolases ; metabolism ; Cellulase ; metabolism ; Cellulose ; metabolism ; Oryza ; enzymology ; Plant Stems ; enzymology ; Steam

To improve the extraction of solanesol from tobacco waste, we developed an enzymatic cell wall-breaking process with combined cellulase and ligninase. The effects of reaction time, temperature, pH and enzyme/substrate ratio were determined. The results show that the catalytic effect was better than either single enzyme when the ratio of cellulase to ligninase was 15:1 (U/U). Under the optimized conditions of 175 U/g (enzymes/substrate), tobacco to water 1:5 (W/W), temperature 40 degrees C and pH 6.0, the concentration of solanesol in the solution could reach 0.33 g/L after 8 h. And the average leaching rate reached 96.53% which was 1.68 times of the extraction methods of chemical reflux. It provides new way for the extraction of solanesol from tobacco waste, and worthwhile to be further explored.
Cell Wall ; metabolism ; Cellulase ; metabolism ; Oxygenases ; metabolism ; Plant Leaves ; chemistry ; Terpenes ; isolation & purification ; Tobacco ; chemistry

OBJECTIVETo research the function of endophytes of mistletoe in parasitism process of mistletoe in Pterocarya stenoptera.

METHODEndophytes from eight different parts of the mistletoe were separated by explant culture, and further screened by different CMC plates culture and DNS method to get cellulase high productive strains. The distribution of the endophytic fungus parasitized in mistletoe were prepared and stained to demonstrate by histological section of the intumescentia part of the P. stenoptera.

RESULTThe histological section indicated that aboundent of hyphasma were distributed around the haustorium of the mistletoe. Eighty three strains of endophytic fungus were separated, 38 of them were able to degrade cellulose, 19 strains showed high cellulase activity and 10 of which were separated from the parasitic position.

CONCLUSIONEndophytic fungus of mistletoe can secrete cellulase and assist the haustorium of mistletoe to breakthrough the cell walls as well as intercellular space tissues of the P. stenoptera, thus, the endophytic fungus plays an important role in the parasitism process of mistletoe in P. stenoptera.

Cellulase ; metabolism ; Cellulose ; metabolism ; Fungi ; metabolism ; Juglandaceae ; Symbiosis ; Viscum ; cytology ; microbiology

OBJECTIVETo investigate the optimal extraction process of polysaccharides from S. fusiforme by enzymatic treatment.

METHODThe optimum extraction conditions were obtained by the experiment with the orthogonal design. The content of polysaccharides of S. fusiforme was determined by spectraphotometry.

RESULTThe amount of enzyme and temperature significantly affected total polysaccharides of S. fusiforme.

CONCLUSIONThe optimum extraction conditions include the addition of 1. 2 x 10 (4) U x 100 g(-1) enzyme into water at pH 4. 5, and the subsequent treatment for 10 min while the temperature is maintained at 45 degrees C.

Cellulase ; metabolism ; Hydrogen-Ion Concentration ; Polysaccharides ; analysis ; isolation & purification ; metabolism ; Sargassum ; chemistry ; Technology, Pharmaceutical ; methods ; Temperature

OBJECTIVETo choose the optimum extraction process of polysaccharide constituents from Panax japonicus.

METHODThe optimal compound enzyme extraction process is selected with the orthogonal design. The yield of polysaccharide was used to evaluate the factor levels, so as to determine the condition of the optimum extraction process.

RESULTThe conditions of the ideal extraction process using compound enzyme method were that of the pH value was at 5.0, the extraction temperature was at 50 degrees C, solvent volume was 50 times of material, cellulase quality score was 1.2%, pectinex quality score was 1.0% and the extraction time was 2 hours. At the last, the vitalitive enzyme was deactivated in the 90 degrees C water for 2 hours. Under these conditions, the yield of polysaccharide extract from P. japonicus was up to 14.3%.

CONCLUSIONThe yield of polysaccharide extracted from P. japonicus can be effectively increased by using compound enzyme extraction process.

Cellulase ; metabolism ; Hydrogen-Ion Concentration ; Panax ; chemistry ; Polysaccharides ; isolation & purification ; metabolism ; Temperature ; Time Factors

A kinetics model was developed for predicting and simulating immobilized cellulase performance, which follows Michaelis-Menten kinetics with competitive product inhibition. Taking into account the effects of competitive product inhibition, inner diffusional limitation, substrate concentration and carrier size, the substrate distribution and the product distribution in carriers were investigated, and the effectiveness factors were also calculated over a wide range of parameters. The effects of competitive product inhibition are shown to increase the substrate concentration in the carrier, and, additionally, to increase the effectiveness factors slightly. With the increase of inner diffusion coefficient, both the effectiveness factors and the substrate concentration in the carrier increase. As the carrier size increases, on the other hand, these values decrease. The effectiveness factors and the substrate concentration in the carrier are found to increase when substrate concentration in the reaction system increases.
Cellulase ; metabolism ; Diffusion ; Enzymes, Immobilized ; metabolism ; Kinetics ; Microspheres ; Models, Chemical ; Particle Size ; Substrate Specificity

We evaluated the effect of biological pretreatment with white rot fungus Trametes vesicolor on the enzymatic hydrolysis of two wood species, Chinese willow (Salix babylonica, hardwood) and China-fir (Cunninghamia lanceolata, softwood). The result indicated that the pretreated woods showed significant increases in the final conversion ratios of enzymatic hydrolysis (4.78-fold for hardwood and 4.02-fold for softwood). In order to understand the role of biological pretreatment we investigated the enzyme-substrate interactions. Biological pretreatment enhanced the substrate accessibility to cellulase but not always correlated with the initial conversion rate. However, the change of the conversion rate decreased dramatically with increased desorption values after biological pretreatment. Thus, the biological pretreatment slowed down the declines in conversion rates during enzymatic hydrolysis by reducing the irreversible adsorption of cellulase and then improved the enzymatic hydrolysis. Moreover, the decreases of the irreversible adsorption may be attributed to the partial lignin degradation and alteration in lignin structure after biological pretreatment.
Adsorption ; Cellulase ; metabolism ; Cunninghamia ; metabolism ; microbiology ; Hydrolysis ; Lignin ; metabolism ; Salix ; metabolism ; microbiology ; Trametes ; metabolism ; physiology ; Wood ; metabolism ; microbiology