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In this work, bagasse pulp was used to prepare cellulose nanofibrils (CNFs) by enzymatic assisted mechanical treatment. A xylanase pretreatment was applied for varying the hemicellulose content in the pulp fibers, and the contribution of this pretreatment to the post-mechanical treatment was investigated. The results showed that CNFs prepared after xylanase pretreatment exhibited enhanced thermal stability with an increase in crystallinity. However, the overall thermal stability of the CNFs decreased significantly after xylanase was applied directly to the mechanical treated CNFs. The results indicate that the presence of hemicellulose in the fiber could affect the thermal stability of CNFs. The direct application of xylanase to CNFs could affect both the hydrogen bond between the hemicellulose and the cellulose and the covalent bond between the hemicellulose molecules, which partially destroys the internal network structure and reduces of thermal stability of CNFs. Graphic abstract

Lately, cocoa pod husk (CPH) has received some attention from researchers due to its significant content of cellulose, hemicelluloses and pectin, antioxidant capacity, potential for energy generation, physicochemical characteristics and possibility to be used as adsorbent material or activated carbon. In this work, alkaline (NaOH 2.3% w/v) and enzymatic treatment [Cellic® CTec 2 (2.4% v/v)] were developed before propionic acid (PA) production using fermentable sugars derived from cocoa pod husk hydrolysate (CPHH). The physical, structural and morphological characteristics of raw and treated samples of CPH lignocellulosic matrix were assessed using tools such as scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetry, and X-ray diffraction. The results of these analyses revealed the effectiveness of CPH sequential alkaline and enzymatic treatment for glucose production, reaching maximum concentration of 60.5 g·L−1 and a yield of 275 mg glucose·g−1 CPH. Subsequently, a medium composed by glucose from CPHH (7.5 g·L−1), as low-cost feedstock, glycerol (7.5 g·L−1) and yeast extract (10 g·L−1), was prepared to obtain PA using Propionibacterium jensenii DSM 20274. PA concentration reached a maximum of 10.28 ± 1.05 g·L−1 and a productivity of 0.08 ± 0.01 g·L−1·h−1 after 72 h of fermentation. To the best of our knowledge, there is no literature available on the bioconversion of CPH for the specific production of PA or other organic acids. Thus, the potential of CPH to be used as substrate for PA production was demonstrated with good perspectives.Graphic abstract

This study aimed to reduce more protein by combining the physical treatment, polishing, and high-pressure enzymatic treatment in a sequence. To understand the mechanism of accelerated hydrolysis during the high-pressure enzymatic treatment process, the effects of pressure on the enzyme and substrate were independently examined, the higher the pressure, the better the enzyme stability. The substrate, rice, also showed increased sensitivity to the enzyme when soaked under high pressure. Although there was no significant difference in the protein content of rice by degree of polishing, greater protein hydrolysis was observed in 130% polished rice than in white rice during the high-pressure enzymatic treatment. As a result, it is expected that the process utilizing the synergistic effect between polishing and high-pressure enzymatic treatment can be applied to a new low-protein rice production method to help improve the diet and quality of life of patients with kidney disease.

Enzymatic treatments in textile are remarkable because of their environmentally friendly properties, such as less energy, water and chemical need, low waste water pollution. In this paper combined use of amylase, pectinase and cellulase in the same bath was studied in different parts. In the first part of the experiment, raw cotton woven fabrics were treated with amylase, pectinase and cellulase enzymes in the same bath at different process conditions to desize, scour and polish. Results showed that one-bath triple enzymatic mixture process could be done successfully. Therefore, it could be used instead of conventional processes. Moreover, the enzymatic process was completed almost in half of the conventional treatments’ durations and temperatures. In the second part, effects of enzymes’ dosages were analyzed by using enzymes in pairwise combinations. By this way, not only the effects of the amount of enzymes but also the effects of each enzyme on each fabric property were seen more distinctly. The increases of enzymes’ concentrations led to an increase in every tested value except tear strength. Pectinase + cellulase combination resulted in minimum tear strength and whiteness, but maximum absorbency. Usage of enzymes one-by-one constituted the final part of the study. It had been found that amylase affected whiteness and absorbency, cellulase affected tear strength particularly. Although combined enzymatic treatments were conducted at more moderate conditions than conventional processes, comparable results were observed.

Purpose of Review Phenolic wastewaters represent a serious health and environmental problem. The remediation of phenolic wastewaters using oxidoreductase enzymes has emerged as an attractive environmentally friendly treatment method. However, the loss of enzyme activity during the treatment remains a key limitation. Thus, the aim of this article is to review and assess the recent progress in utilizing surface active additives (i.e., polymers, biopolymers, surfactants, and biosurfactants) for the reduction of enzyme inhibition and, thus, the enhancement of enzymatic remediation of phenolic wastewaters. Recent Findings The reported effect of polymeric and surfactant additives on the enzymatic remediation of phenolic pollutants is mixed. Some studies reported significant enhancements while others demonstrated minimal or no gains. More seriously, it has been reported that these fossil-based additives might lead to a higher toxicity of the treated wastewaters. Bio-based (biopolymers and biosurfactants) additives might address this toxicity issue; however, the bio-based additives are not always as effective as the fossil-based ones. Summary Despite the beneficial effect, with some exceptions, of additives, the enhancement level varies widely, probably due to the variations in the reaction environment. Thus, to draw meaningful and reliable conclusions on which additive(s) is more promising, thorough studies under unified conditions are needed. Additionally, generation of secondary pollutions associated with the fossil-based additives urges the replacement of such additives with bio-based ones. However, the effectiveness of the bio-based additives is still not sufficiently documented, stressing the need for more in-depth studies.

Fucoidans from brown macroalgae (brown seaweeds) have different structures and many interesting bioactivities. Fucoidans are classically extracted from brown seaweeds by hot acidic extraction. Here, we report a new targeted enzyme-assisted methodology for fucoidan extraction from brown seaweeds. This enzyme-assisted extraction protocol involves a one-step combined use of a commercial cellulase preparation (Cellic®CTec2) and an alginate lyase from Sphingomonas sp. (SALy), reaction at pH 6.0, 40 °C, removal of non-fucoidan polysaccharides by Ca2+ precipitation, and ethanol-precipitation of crude fucoidan. The workability of this method is demonstrated for fucoidan extraction from Fucus distichus subsp. evanescens (basionym Fucus evanescens) and Saccharina latissima as compared with mild acidic extraction. The crude fucoidans resulting directly from the enzyme-assisted method contained considerable amounts of low molecular weight alginate, but this residual alginate was effectively removed by an additional ion-exchange chromatographic step to yield pure fucoidans (as confirmed by 1H NMR). The fucoidan yields that were obtained by the enzymatic method were comparable to the chemically extracted yields for both F. evanescens and S. latissima, but the molecular sizes of the fucoidans were significantly larger with enzyme-assisted extraction. The molecular weight distribution of the fucoidan fractions was 400 to 800 kDa for F. evanescens and 300 to 800 kDa for S. latissima, whereas the molecular weights of the corresponding chemically extracted fucoidans from these seaweeds were 10–100 kDa and 50–100 kDa, respectively. Enzyme-assisted extraction represents a new gentle strategy for fucoidan extraction and it provides new opportunities for obtaining high yields of native fucoidan structures from brown macroalgae.

This research work seeks to evaluate the impact of selected enzyme complexes on the optimised release of phenolics from leaves of Pongamia pinnata . After preliminary solvent extraction, the P. pinnata leaf extract was subjected to enzymatic treatment, using enzyme cocktails such as kemzyme dry-plus, natuzyme, and zympex-014. It was noticed that zympex-014 had a greater extract yield (28.0%) than kemzyme dry-plus (17.0%) and natuzyme (18.0%). Based on the better outcomes, zympex-014-based extract values were subsequently applied to several RSM parameters. The selected model is suggested to be significant by the F value (12.50) and R 2 value (0.9669). The applicability of the ANN model was shown by how closely the projected values from the ANN were to the experimental values. In terms of total phenolic contents (18.61 mg GAE/g), total flavonoid contents (12.56 mg CE/g), and DPPH test (IC50) (6.5 g/mL), antioxidant activities also shown significant findings. SEM analysis also revealed that the cell walls were damaged during enzymatic hydrolysis, as opposed to non-hydrolysed material. Using GC-MS, five potent phenolic compounds were identified in P. pinnata extract. According to the findings of this study, the recovery of phenolic bioactives and subsequent increase in the antioxidant capacity of P. pinnata leaf extract were both positively impacted by the optimisation approaches suggested, including the use of zympex-014.

Chitin is an abundant polysaccharide primarily produced as an industrial waste stream during the processing of crustaceans. Despite the limited applications of chitin, there is interest from the medical, agrochemical, food and cosmetic industries because it can be converted into chitosan and partially acetylated chitosan oligomers (COS). These molecules have various useful properties, including antimicrobial and anti-inflammatory activities. The chemical production of COS is environmentally hazardous and it is difficult to control the degree of polymerization and acetylation. These issues can be addressed by using specific enzymes, particularly chitinases, chitosanases and chitin deacetylases, which yield better-defined chitosan and COS mixtures. In this review, we summarize recent chemical and enzymatic approaches for the production of chitosan and COS. We also discuss a design-of-experiments approach for process optimization that could help to enhance enzymatic processes in terms of product yield and product characteristics. This may allow the production of novel COS structures with unique functional properties to further expand the applications of these diverse bioactive molecules.

Pea protein (PP) was moderately hydrolyzed using four proteolytic enzymes including flavourzyme, neutrase, alcalase, and trypsin to investigate the influence of the degree of hydrolysis (DH) with 2%, 4%, 6%, and 8% on the structural and functional properties of PP. Enzymatic modification treatment distinctly boosted the solubility of PP. The solubility of PP treated by trypsin was increased from 10.23% to 58.14% at the 8% DH. The results of SDS-PAGE indicated the protease broke disulfide bonds, degraded protein into small molecular peptides, and transformed insoluble protein into soluble fractions with the increased DH. After enzymatic treatment, a bathochromic shift and increased intrinsic fluorescence were observed for PP. Furthermore, the total sulfhydryl group contents and surface hydrophobicity were reduced, suggesting that the unfolding of PP occurred. Meanwhile, the foaming and emulsification of PP were improved after enzymatic treatment, and the most remarkable effect was observed under 6% DH. Moreover, under the same DH, the influence on the structure and functional properties of PP from large to small are trypsin, alcalase, neutrase and flavourzyme. This result will facilitate the formulation and production of natural plant-protein-based products using PP.

The excessive utilization of petroleum resources leads to global warming, crude oil price fluctuations, and the fast depletion of petroleum reserves. Biodiesel has gained importance over the last few years as a clean, sustainable, and renewable energy source. This review provides knowledge of biodiesel production via transesterification/esterification using different catalysts, their prospects, and their challenges. The intensive research on homogeneous chemical catalysts points to the challenges in using high free fatty acids containing oils, such as waste cooking oils and animal fats. The problems faced are soap formation and the difficulty in product separation. On the other hand, heterogeneous catalysts are more preferable in biodiesel synthesis due to their ease of separation and reusability. However, in-depth studies show the limited activity and selectivity issues. Using biomass waste-based catalysts can reduce the biodiesel production cost as the materials are readily available and cheap. The use of an enzymatic approach has gained precedence in recent times. Additionally, immobilization of these enzymes has also improved the statistics because of their excellent functional properties like easy separation and reusability. However, free/liquid lipases are also growing faster due to better mass transfer with reactants. Biocatalysts are exceptional in good selectivity and mild operational conditions, but attractive features are veiled with the operational costs. Nanocatalysts play a vital role in heterogeneous catalysis and lipase immobilization due to their excellent selectivity, reactivity, faster reaction rates owing to their higher surface area, and easy recovery from the products and reuse for several cycles.