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Influence of water content on the expression of lignocellulolytic enzymes by Phanerochaete chrysosporium remains unclear. This work compares the enzyme production profiles of P. chrysosporium during solid-state and submerged fermentation. There were 110 and 64 extracellular carbohydrate-active enzymes identified in solid-state and submerged fermentation respectively, among which 57 enzymes were common to both of the secretomes. P. chrysosporium secreted more cellulases (especially lytic polysaccharide monooxygenase) and hemicellulases during solid-state fermentation while the proportion of enzyme containing carbohydrate-binding module was higher for submerged fermentation. Although its activities were weaker, the enzyme cocktail from submerged fermentation was surprisingly more effective in hydrolysis at low substrate loading. This advantage of enzymes from submerged fermentation was mainly attributed to carbohydrate-binding module because more xylanases bound with substrate at the beginning of hydrolysis. These results reveal the influence of fermentation conditions on enzyme produced by P. chrysosporium for the first time and show the importance of carbohydrate-binding module in the hydrolysis process of lignocellulose. • Secrotomes of Phanerochaete chrysosporium under SSF and SmF were compared. • P. chrysosporium secreted more kinds of enzyme with higher activities under SSF. • Enzyme cocktail from SmF was more effective in hydrolysis at low substrate loading. • Advantage of enzymes from SmF in hydrolysis was mainly attributed to more CBMs. [ABSTRACT FROM AUTHOR]

Herein, we report the secretome of Penicillium chrysogenum P33 under induction of lignocellulose for the first time. A total of 356 proteins were identified, including complete cellulases and numerous hemicellulases. Supplementing a commercial cellulase with increasing dosage of P33 enzyme cocktail from 1 to 5 mg/g substrate increased the release of reducing sugars from delignified corn stover by 21.4% to 106.8%. When 50% cellulase was replaced by P33 enzyme cocktail, release of reducing sugars was 78.6% higher than with cellulase alone. Meanwhile, glucan and xylan conversion was increased by 37% and 106%, respectively. P33 enzyme cocktail also enhanced commercial cellulase hydrolysis against four different delignified lignocellulosic biomass. These findings demonstrate that mixing appropriate amount of P33 cocktail with cellulase improves polysaccharide hydrolysis, suggesting P33 enzymes have great potential for industrial applications. [ABSTRACT FROM AUTHOR]

Abstract: Sugarcane bagasse (SCB) is a residual product of sugar processing, containing mainly lignocellulose. The biodegradation of cellulose is an economical approach to recycling SCB. To obtain an effective microbial community and study the SCB biodegradation process, a SCB-degrading mesophilic microbial community, EMSD13, growing at 50°C was isolated. More than 77% of alkali pretreated SCB was degraded and over 83% of the cellulose it contained was utilized by the EMSD13 community within 6 days. To understand the biodegradation procedure of EMSD13, extracellular and SCB-absorbable cellulases were analyzed. The peak activity (42mU/mL) of the extracellular cellulase in the supernatant occurred on the 3rd day of incubation. About 73.6mg of substrate-bound proteins with a cellulase activity of 61.1mU/mg were recovered from residual SCB by eluting with 3M guanidine hydrochloride. Also, 15.9mg of proteins with 28.6mU/mg of cellulase activity were obtained from residual SCB by eluting with 6M urea. SDS-PAGE analysis showed that cellulases in both elutes were similar, but most differed from those in the supernatant. This is the first report on substrate-bound cellulases from a microbial community. [Copyright &y& Elsevier]

Optimization of the composition of enzyme cocktail is an effective way to improve the hydrolytic efficiency and reduce the cost during enzymatic hydrolysis of lignocellulose. Herein, the optimal enzymes ratios of enzyme cocktails for efficient hydrolysis of corncobs with distinct pretreatments were quantitatively formulated. As the importance of pretreatment type on xylan extraction, the optimized cellulase/hemicellulase ratios for NaClO 2 , H 2 SO 4 and steam explosion treated corncob were 1:1.5, 1:0.15 and 1:0.75, respectively. Meanwhile, different requirements for types of cellulases are also determined: endoglucanase and cellobiohydrolase were key enzymes in the hydrolysis of NaClO 2 and H 2 SO 4 treated corncobs, respectively, while the synergy of three kinds of cellulases was preferred for steam-exploded corncob. Furthermore, based on the optimized cellulase/hemicellulase ratios, cellulases proportions for hydrolyzing the corncobs pretreated with distinctive methods were determined. Notably, by the enzymatic formulation strategy, 100% yields of glucose and xylose were obtained simultaneously from NaClO 2 treated corncob, which was up to 70.1% and 80.1% at high solid loading (20%), respectively. Without detoxification of hydrolysate, high isopropanol yield of 0.45 g/g (of dry matter) was achieved. Hence, this study demonstrated a low cost and high efficient conversion strategy for prospective high-value utilization of lignocellulose. • Three pretreatments for lignin and hemicellulose extraction were tested. • Key enzymes for hydrolyzing corncobs with distinct pretreatments were analyzed. • 100% glucose and xylose of sodium chlorite treated corncob were obtained. • Maximum corncob biomass conversion to biofuels was unlocked. [ABSTRACT FROM AUTHOR]

[Display omitted] • Distinct pretreated substrate can be used as inducer for specific enzyme production. • Formulation of cocktails with distinct components improved the hydrolysis efficiency. • 100% glucose and xylose of ultrafine grinding treated corn stover were obtained. In order to optimize the composition of enzyme cocktail for improving the hydrolytic efficiency of lignocellulose, different substrates were tested as inducers for producing lignocellulolytic enzymes by Trichoderma harzianum EM0925 in this study. As results, ultrafine grinding or steam explosion pretreated substrates can induce T. harzianum EM0925 to secret holo lignocellulolytic enzymes; acid treated substrate can induce cellobiohydrolase; while alkali or sodium chlorite treated substrates can induce β-xylosidase specifically. Furthermore, the combination of enzyme cocktails with different hydrolysis characteristics can further improve the hydrolysis efficiency, since 100% yields of glucose and xylose were obtained simultaneously from ultrafine grinding treated corn stover at low enzyme dosage (1.2 mg proteins/g substrate). This study for the first time demonstrated an effective solution that specific-pretreated substrates can be used as inducers for specific enzyme production by T. harzianum , which provided new idea and potential strategy for the construction of highly-efficient lignocellulolytic enzyme cocktails. [ABSTRACT FROM AUTHOR]