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[Display omitted] • SM and AW fermentation for LA production via enzyme pretreatment was investigated. • High LA level of 42.70 g/L was observed at enzyme loading of 300 U/g VS substrate. • Enzymatic pretreatment boosted SM and AW solubilization and hydrolysis. • Lactobacillus for LA production was enriched by enzymatic pretreatment. Anaerobic co-fermentation of swine manure (SM) and apple waste (AW) restricts by the slow hydrolysis of substrates with complex structures, which subsequently leads to low lactic acid (LA) production. Therefore, a novel strategy based on enzymatic pretreatment for improving LA production from anaerobic co-fermentation of SM and AW was proposed in this study. The results indicated that the maximal LA concentration increased from 35.89 ± 1.84 to 42.70 ± 2.18 g/L with the increase of enzyme loading from 0 to 300 U/g VS substrate. Mechanism exploration indicated that enzymatic pretreatment significantly promoted the release and hydrolysis of insoluble organic matter from fermentation substrate, thus providing an abundance of reaction intermediates that were directly available for LA production. Additionally, bacteria analysis revealed that the high concentration of LA was associated with the prevalence of Lactobacillus. This study offered an environmental-friendly strategy for promoting SM and AW hydrolysis and provided a viable approach for recovering valuable products. [ABSTRACT FROM AUTHOR]

The microbial decomposition and utilization of lignocellulosic biomass present in the plant tissues are driven by a series of carbohydrate active enzymes (CAZymes) acting in concert. As the non-catalytic domains widely found in the modular CAZymes, carbohydrate-binding modules (CBMs) are intimately associated with catalytic domains (CDs) that effect the diverse hydrolytic reactions. The CBMs function as auxiliary components for the recognition, adhesion, and depolymerization of the complex substrate mediated by the associated CDs. Therefore, CBMs are deemed as significant biotools available for enzyme engineering, especially to facilitate the enzymatic hydrolysis of dense and insoluble plant tissues to acquire more fermentable sugars. This review aims at presenting the taxonomies and biological properties of the CBMs currently curated in the CAZy database. The molecular mechanisms that CBMs use in assisting the enzymatic hydrolysis of plant polysaccharides and the regulatory factors of CBM-substrate interactions are outlined in detail. In addition, guidelines for the rational designs of CBM-fused CAZymes are proposed. Furthermore, the potential to harness CBMs for industrial applications, especially in enzymatic pretreatment of the recalcitrant lignocellulose, is evaluated. It is envisaged that the ideas outlined herein will aid in the engineering and production of novel CBM-fused enzymes to facilitate efficient degradation of lignocellulosic biomass to easily fermentable sugars for production of value-added products, including biofuels. • Microbial CBMs are categorized based on substrate-binding pockets. • Mechanisms of three CBMs in the hydrolysis of plant biomass are illustrated. • Feasible approaches to construct effective CBM-fused enzymes are proposed. • Strategies to exploit CBMs for the hydrolysis of lignocellulose are summarized. [ABSTRACT FROM AUTHOR]

In this study, a fungal mash rich in hydrolytic enzymes was in-situ produced from the waste cake and was further applied for the hydrolysis of mixed food wastes. A well balanced nutrient stream containing a 127 g/L glucose and 1.8 g/L free amino nitrogen was produced from the enzymatic pretreatment of food wastes using this fungal mash at 24 h. Using this solution as sole fermentation feedstock, 58 g/L of ethanol corresponding to an ethanol yield of 0.5 g/g glucose was obtained within 32 h. It was demonstrated that the pretreatment of mixed food wastes with the fungal mash produced in this study is an effective option for food waste saccharification and bioethanol production. [ABSTRACT FROM AUTHOR]

In this study, a fungal mash rich in hydrolytic enzymes was produced by solid state fermentation (SSF) of waste cake in a simple and efficient manner and was further applied for high-efficiency hydrolysis of mixed food wastes (FW). The enzymatic pretreatment of FW with this fungal mash resulted in 89.1 g/L glucose, 2.4 g/L free amino nitrogen, 165 g/L soluble chemical oxygen demand (SCOD) and 64% reduction in volatile solids within 24 h. The biomethane yield and production rate from FW pretreated with the fungal mash were found to be respectively about 2.3 and 3.5-times higher than without pretreatment. After anaerobic digestion of pretreated FW, a volatile solids removal of 80.4 ± 3.5% was achieved. The pretreatment of mixed FW with the fungal mash produced in this study is a promising option for enhancing anaerobic digestion of FW in terms of energy recovery and volume reduction. [ABSTRACT FROM AUTHOR]

Abstract: This study aimed at evaluating the effect of increasing organic loading rates and of enzyme pretreatment on the stability and efficiency of a hybrid upflow anaerobic sludge blanket reactor (UASBh) treating dairy effluent. The UASBh was submitted to the following average organic loading rates (OLR) 0.98Kg.m−3.d−1, 4.58Kg.m−3.d−1, 8.89Kg.m−3.d−1 and 15.73Kg.m−3.d−1, and with the higher value, the reactor was fed with effluent with and without an enzymatic pretreatment to hydrolyze fats. The hydraulic detention time was 24h, and the temperature was 30±2°C. The reactor was equipped with a superior foam bed and showed good efficiency and stability until an OLR of 8.89Kg.m−3.d−1. The foam bed was efficient for solid retention and residual volatile acid concentration consumption. The enzymatic pretreatment did not contribute to the process stability, propitiating loss in both biomass and system efficiency. Specific methanogenic activity tests indicated the presence of inhibition after the sludge had been submitted to the pretreated effluent. It was concluded that continuous exposure to the hydrolysis products or to the enzyme caused a dramatic drop in the efficiency and stability of the process, and the single exposure of the biomass to this condition did not inhibit methane formation. [Copyright &y& Elsevier]

Abstract: The production of ethanol from feedstock other than agriculture materials has been promoted in recent years. Some microalgae can accumulate a high starch content (about 44% of dry base) via photosynthesis. Algal biomass, Chlamydomonas reinhardtii UTEX 90, was converted into a suitable fermentable feedstock by two commercial hydrolytic enzymes. The results showed that almost all starch was released and converted into glucose without steps for the cell wall disruption. Various conditions in the liquefaction and saccharification processes, such as enzyme concentration, pH, temperature, and residence time, have been investigated to obtain an optimum combination using the orthogonal analysis. As a result, approximately 235mg of ethanol was produced from 1.0g of algal biomass by a separate hydrolysis and fermentation (SHF) method. The main advantages of this process include the low cost of chemicals, short residence time, and simple equipment system, all of which promote its large-scale application. [Copyright &y& Elsevier]

The filamentous fungus Rhizopus microsporus CPQBA 312-07 DRM was grown in solid-state cultivation and the fermented solid produced was used to hydrolyze triacylglycerols in a high-fat dairy wastewater. For the solid-state cultivation, a mixture of sunflower seed meal and sugarcane bagasse (1:3 by mass on dry basis) was selected. After 18 h of culture, the fermented product had an activity, measured titrimetrically against triolein, of 26 U per gram of dry solids. This substrate mixture does not suffer from compaction and therefore can be used in large scale solid-state cultivation bioreactors. When used to pretreat a high-fat dairy wastewater, with an oil and grease level above 1300 mg/L, the fermented solid reduced the oil and grease level to below 300 mg/L after 72 h at 35 °C. Further work is required to improve the production of lipolytic activity in the solid-state cultivation step and to find the optimum pretreatment time in the wastewater pretreatment step. [ABSTRACT FROM AUTHOR]

[Display omitted] • One-stage enzymatic hydrolysis was established to pretreat starch wastewater. • Microalgae cultivation could be improved using wastewater pretreated by enzymes. • TN and TP in wastewater can be effectively removed by microalgae cultivation. • Lutein yield and COD removal were enhanced using cyclic feeding cultivation mode. • Total lutein yield and COD removal efficiency reached 14.86 mg/L and 73.2%. The main purpose of this study was to explore the pretreatment process of corn starch wastewater (CSW) and engineered microalgae cultivation strategy to improve the nutrient recovery from wastewater and the yield of microalgae lutein. One-stage enzymatic hydrolysis utilizing α-amylase and glucoamylase simultaneously was established to efficiently harvest a maximum concentration of reducing sugar content of 7.26 g/L from CSW in 50 min. Lutein yield of 10.96 mg/L was obtained under 24 h continuous illumination with 2200 Lux light intensity. Furthermore, a cyclic feeding cultivation strategy was developed to improve lutein accumulation and COD removal up to 25.9 mg/L and 50.7%, respectively, after three cultivation cycles. Lutein yield of 14.86 mg/L and COD removal efficiency of 73.2% was achieved with further implementation in actual wastewater. This work provided a new perspective in developing the potential of cultivating microalgae with corn starch wastewater to produce high-value lutein. [ABSTRACT FROM AUTHOR]

[Display omitted] • Adding lysozyme at 0 h and protease at 1 h with the ratio of 4:1 was the best. • Dosing time was as essential as dosing ratio for pretreatment efficiency. • Enzyme cocktails triggered more extracellular biodegradable organic substances. • Lysozyme and protease cocktail enhanced hydrolysis synergistically. • Enzymatic sludge reduced carbon emission in place of methanol as carbon source. This study introduced the excellent improvement of enzyme cocktail (lysozyme and protease) on hydrolysis efficiency and the role of reducing carbon emission as an alternative carbon source. The best dosing method after optimization was to add four parts of lysozyme at 0 h and one part of protease at 1 h. The extracellular proteins and polysaccharides increased by 118% and 64% respectively under the optimal dosing mode. Enzyme cocktails reduced more organic matters and extended the distribution of sludge particles in the small particle size part. The enzymatic-treated sludge could reduce 21.09 kg CO 2 /t VSS if utilized to replace methanol for denitrification carbon source. Enzyme cocktails did better in enhancing both solubilization and hydrolysis than single enzymes under the optimal method. This study will provide a more integrated and comprehensive system for enzymatic pretreatment and new insight into the enzymatic pretreatment enhancing hydrolysis and reducing carbon emission. [ABSTRACT FROM AUTHOR]

The possibility of improving the nutritional quality of plant byproducts (brewers' spent grain and rice bran) through an enzyme treatment was tested in a formulated feed for grey mullet (Mugil cephalus). The enzyme treatment was carried out by Solid-State Hydrolysis (SSH) using a commercial preparation including carbohydrases and phytase. A feed prepared without the treatment and a commercial feed for carp were used as controls. In a preliminary short-term trial carried out at laboratory facilities, fish receiving the enzyme-treated feed showed significant improvement in both FCR and SGR when compared to those obtained with the untreated diet, although both experimental diets presented worse values than those obtained with the commercial feed. Different metabolic indicators including higher values of muscle glycogen and plasmatic triglycerides supported the positive effect of the enzyme treatment on the nutritional condition of the fish over those fed on the diet containing non-treated ingredients. Results of growth and feed efficiency that were obtained in a second long-term trial developed for 148 days under real production conditions evidenced the equivalence among the experimental and commercial diets and confirmed that enzyme pretreatment of plant ingredients by SSH may be a useful procedure to improve the nutritive value of high fiber plant byproducts when included in practical diets for this species and others with similar nutritional features. [ABSTRACT FROM AUTHOR]

An experiment was conducted to study the preparation of wine using locally available different rice varieties viz., CR1009, ADT 36, and IR 20. The standard yeast strain such as Saccharomyces cerevisiae was used for wine preparation using enzymatic pretreatment method, to obtain maximum reducing sugars. Among the different pretreatment methods, enzymatic pretreatment with Diastase α-amylase was selected for hydrolysis in wine preparation as it shows the highest release of reducing sugars. The chemical analysis of wine prepared with Saccharomyces cerevisiae at 5 per cent inoculums level. The chemical analysis and organoleptic evaluation showed that efficient wine can be prepared using standard yeast strain Saccharomyces cerevisiae at 5 per cent inoculums level with alcohol content. [ABSTRACT FROM AUTHOR]