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With rapid growth of global population, meeting the increasing demand for food has become a significant challenge. This challenge is further compounded by limited arable land and the necessity to address the nutritional needs of both humans and animals. However, the utilization of straw biomass, which is readily available as an agricultural by‐product, presents a sustainable solution to this problem. Microbial fermentation has emerged as a highly effective method for converting non‐food biomass into protein, particularly known as single‐cell protein (SCP). Compared to traditional protein sources, SCP production through microbial fermentation is rapid and efficient, and requires minimal land resources. This review provides a comprehensive review of the research advancements in SCP from agricultural biomass, including pretreatment methods, microbial strains, and fermentation processes involved in the bioconversion of straw biomass. Due to the complexity of straw‐based biomass (SBB), it is essential to customize industrial strains and optimize the fermentation process to achieve the highest protein yield and productivity. Additionally, improving the compatibility between tailored processes and cost‐effective industrial strains can lead to the production of protein substitutes that are not only highly nutritious but also economically viable. Hence, the application of SCP derived from SBB presents a dual solution by reducing the need for managing agricultural residues and providing a sustainable source of protein. However, the production of SCP from SBB also has some limitations, such as protein‐synthesis efficiency, production cost, and difficulty to scale‐up the production process. In the future, there is great potential for significant advancements in the targeted conversion of SBB into protein by customizing high‐performance microbial strains. Several sensor and machine learning technologies will predict and monitor real‐time dynamic changes in the fermentation process of SBB, offering an opportunity to improve the production of sustainable SCP in an environmentally friendly and precise manner. [ABSTRACT FROM AUTHOR]

Starch foam is a completely biodegradable material that can replace petroleum‐based foams. However, starch foams are sensitive to water and have poor mechanical properties. Khlum fiber that had been alkali‐treated for 1 h (KF‐1h) showed excellent properties as a reinforcement of starch foam. KF‐1h was added to starch at loadings of 0, 1, 3, 5, and 7 wt%. The starch foam composite reinforced with 1 wt% of KF‐1h presented uniformly distributed cells of uniform size, and produced the highest values for flexural stress at maximum load (3.43 MPa), hardness (92.50), and water contact angle (122°) of the studied foams. The modulus of the starch foam composite increased with increments of KF‐1h content but the density and color of the starch foam and the biodegradation process in soil were only slightly affected. This work also demonstrated a practical application of the proposed starch foam composite as a biodegradable food container. [ABSTRACT FROM AUTHOR]

The enormous amount of agroindustrial residues generated in Brazil can be used as biomass to produce fermentable sugars. This study compared the pretreatments with different proportions of dilute acid. The method involved pretreatment with 0.5%, 1%, and 1.5% (v/v) sulfuric acid, followed by hydrolysis using the halotolerant and thermostable endoglucanase from Botrytis ricini URM 5627. The physicochemical characterization of plant biomass was performed using XRD, FTIR, and SEM. The pretreatment significantly increased the production of fermentable sugars following enzymatic saccharification from wheat bran, sugarcane bagasse, and rice husk: 153.67%, 91.98%, and 253.21% increment in sugar production; 36.39 mg⋅g−1 ± 1.23, 39.55 mg⋅g−1 ± 1.70, and 42.53 mg⋅g−1 ± 7.61 mg⋅L−1 of glucose; and 3.26 ± 0.35 mg⋅g−1, 3.61mg⋅g−1 ± 0.74 and 3.59 mg⋅g−1 ± 0.80 of fructose were produced, respectively. In conclusion, biomass should preferably be pretreated before the enzymatic saccharification using B. ricini URM 5627 endoglucanase. [ABSTRACT FROM AUTHOR]

This study investigates how enzymatic activity (X1) and pretreated soybean straw concentration (X2) affect the production of cellulose nanofibers and reducing sugars using the Composite Central Rotational Design (CCRD). The soybean straw is subjected to alkaline pretreatment with either 5% NaOH (PT1) or 17.5% NaOH (PT2), followed by bleaching (4% H2O2) and enzymatic treatment. The mathematical model generated by Response Surface Methodology (RSM) predicts that increasing X1 and X2 simultaneously is necessary to increase the nanocellulose yield. On the other hand, to increase the sugar yield, it is necessary to increase the ratio X1:X2. The model also predicts that the lowest concentration of soybean straw (1.17%) resulted in more stable nanofiber suspensions, regardless of the enzyme activity (−25.0 and −19.4 mV for PT1 and PT2, respectively). The optimal condition for the simultaneous production of cellulose nanofibers and reducing sugars is 4.0 g of biomass and enzymatic activity of 600 CMCU, resulting for PT1 and PT2, respectively: 7.01 and 3.73 g of nanofibers/100 g of soybean straw; 11.34 and 14.30 g of reducing sugars/100 g of soybean straw. Therefore, the processing efficiency according to the pretreatment used can directly guide the production of cellulose nanofibers and reducing sugars. [ABSTRACT FROM AUTHOR]

Lignocellulosic materials have arisen as a sustainable alternative in microextraction techniques during the last 10 years. As they are natural materials, their use fits into some of the principles of Green Analytical Chemistry. Their inherent porosity, narrow shape, and rigidity permit their use in ambient ionization mass spectrometry techniques. In particular, the combination of wooden‐based materials and direct analysis gives birth to the so‐called wooden‐tip electrospray ionization mass spectrometry technique. This approach has been used for the direct analysis of complex samples, and as a streamlined tool for fingerprint quality analysis. Also, wooden‐based materials can be superficially modified to boost the interaction with target compounds, allowing their isolation from complex samples. This review describes the potential and applicability of direct analysis using lignocellulosic materials, as well as other alternatives related to their use in microextraction. [ABSTRACT FROM AUTHOR]

In this work, a mathematical model is proposed to predict the kinetic behaviour of the enzymatic conversion of various types of lignocellulosic biomass into fermentable sugars. Digestion of the cellulosic polymers is carried out using enzymatic hydrolysis under different conditions. Unlike other kinetic models, published previously for this process, this one considers the heterogeneous nature of the process by which a solid, in the form of small particles, is decomposed to monosaccharides by the action of a diverse set of enzymes in solution. The effect of the particle size on the hydrolysis rate has also been taken into consideration. To assess the model's goodness of fit to any general situation, the experimental data obtained in the hydrolysis of three different lignocellulosic residues have been analysed. Thus, the hydrolysis data of wheat straw, rice husks and exhausted sugar beet pellets have been compared with the theoretical values calculated by the model. The results obtained show that this model predicts the enzyme's hydrolysis of lignocellulosic substrates under different conditions very accurately and it could therefore be used efficiently in the optimization of the hydrolysis processes implemented in the bio‐refinery industry. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Functionalizing biosourced materials is a major topic in the field of materials science. In particular, grafting polymerization techniques have been employed to change the surface properties of various substrates. Here, we report on the grafting of amphiphilic block copolymers in lignocellulosic materials using surface‐initiated activators generated by electron transfer atomic transfer radical polymerization (SI‐AGET‐ATRP). With this modification, it is possible to combine the interesting properties (anisotropy and high mechanical stability) of lightweight lignocellulosic materials, such as wood, with the special properties of the grafted block copolymers. Hydroxyl groups on wood cell wall biopolymers were used for the chemical bonding of an alkyl bromide as the initiator for AGET‐SI‐ATRP of a highly hydrophilic monomer ([2‐(methacryloyloxy)ethyl]trimethylammonium chloride) and a highly hydrophobic fluorinated monomer (2,2,3,3,4,4,5,5‐octafluoropentyl methacrylate). The successful grafting of homopolymers and block copolymers onto the wood structure was confirmed through Fourier transform infrared and Raman spectroscopy. The functionalization with the two homopolymers yielded lignocellulosic materials with opposite wettabilities, whereas by the adjustment of the ratio between the two copolymer blocks, it was possible to tune the wettability between these two extremes. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 885–897 Amphiphilic block copolymers were synthesized on a bio‐based bulk material (wood) containing a superhydrophilic monomer ([2‐(methacryloyloxy)ethyl]trimethylammonium chloride) and a highly hydrophobic fluorinated monomer (2,2,3,3,4,4,5,5‐octafluoropentyl methacrylate). The feasibility of growing the combination of these two monomers onto a solid scaffold is characterized. The different wettability properties obtained by the introduction of these monomers onto the wood scaffold, by themselves and in combination, are shown. [ABSTRACT FROM AUTHOR]

Cellulose nanocrystals (CNCs) are unique, renewable top-down nano particles from which coatings with improved gas barrier properties and new functionalities can be prepared. In this paper, the potential for obtaining such high performing nanocrystals from low-cost lignocellulosic by-products or raw materials is proved by a comparison study on CNCs obtained both from cotton linters and kraft pulp, by means of the ammonium persulfate (APS) process. Morphological and chemical characterization of the nanocrystals obtained, as well as the main functional properties of the poly(ethylene terephthalate) coated films, showed quite similar characteristics and performances of CNCs obtained from pure cellulose raw material (cotton linters) and the nanoparticles produced from a potential discard of paper making processes (kraft pulp). In particular, the gas barrier properties of the coating produced with CNCs obtained from kraft pulp were very promising, providing oxygen and carbon dioxide permeability values hundreds of times lower than those of equal thickness in comparison with common barrier synthetic polymers, over a broad range of temperatures. The results obtained are relevant not only for the outstanding performances achieved, but also because they evoke a possible positive example of industrial symbiosis in the packaging field, merging together the requirements and needs of the paper and plastic industries and addressing the way towards a better management of waste and materials. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

ABSTRACT In this study, we extend imaging and modeling work that was done in Part I of this report for a pure cellulose substrate (filter paper) to more industrially relevant substrates (untreated and pretreated hardwood and switchgrass). Using confocal fluorescence microscopy, we are able to track both the structure of the biomass particle via its autofluorescence, and bound enzyme from a commercial cellulase cocktail supplemented with a small fraction of fluorescently labeled Trichoderma reseii Cel7A. Imaging was performed throughout hydrolysis at temperatures relevant to industrial processing (50°C). Enzyme bound predominantly to areas with low autofluorescence, where structure loss and lignin removal had occurred during pretreatment; this confirms the importance of these processes for successful hydrolysis. The overall shape of both untreated and pretreated hardwood and switchgrass particles showed little change during enzymatic hydrolysis beyond a drop in autofluorescence intensity. The permanence of shape along with a relatively constant bound enzyme signal throughout hydrolysis was similar to observations previously made for filter paper, and was consistent with a modeling geometry of a hollowing out cylinder with widening pores represented as infinite slits. Modeling estimates of available surface areas for pretreated biomass were consistent with previously reported experimental results. Biotechnol. Bioeng. 2015;112: 32-42. © 2014 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

ABSTRACT Enzymatic hydrolysis is one of the critical steps in depolymerizing lignocellulosic biomass into fermentable sugars for further upgrading into fuels and/or chemicals. However, many studies still rely on empirical trends to optimize enzymatic reactions. An improved understanding of enzymatic hydrolysis could allow research efforts to follow a rational design guided by an appropriate theoretical framework. In this study, we present a method to image cellulosic substrates with complex three-dimensional structure, such as filter paper, undergoing hydrolysis under conditions relevant to industrial saccharification processes (i.e., temperature of 50°C, using commercial cellulolytic cocktails). Fluorescence intensities resulting from confocal images were used to estimate parameters for a diffusion and reaction model. Furthermore, the observation of a relatively constant bound enzyme fluorescence signal throughout hydrolysis supported our modeling assumption regarding the structure of biomass during hydrolysis. The observed behavior suggests that pore evolution can be modeled as widening of infinitely long slits. The resulting model accurately predicts the concentrations of soluble carbohydrates obtained from independent saccharification experiments conducted in bulk, demonstrating its relevance to biomass conversion work. Biotechnol. Bioeng. 2015;112: 21-31. © 2014 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

BACKGROUND Rice straw is an attractive lignocellulosic material for ethanol production, since it is one of the most abundant renewable resources. It generally has high cellulose and hemicellulose contents that can be readily hydrolysed into sugars for subsequent ethanol fermentation. The pretreatment method plays an important role in increasing the efficiency of enzymatic saccharification, thereby making the whole process economically viable. Torrefaction is an appropriate pretreatment technique for enhancing the enzymatic reaction and subsequent ethanol production. RESULTS The effects of two important parameters, i.e. residence time (20, 40 and 60 min) and temperature (160, 180, 200, 220, 240 and 260 °C), were studied under an inert atmosphere. The highest yield of 351 ± 5.49 mg g−1 total sugars was obtained after torrefaction treatment at 220 °C for 40 min, representing a 60.68% increase compared with the untreated sample. Based on ethanol studies conducted on rice straw, this estimated quantity of sugars could produce 150 ± 2.40 mg g−1 ethanol, a 50.67% increase compared with the untreated sample under anaerobic conditions. The fermentation rate was enhanced by adding 0.4 mmol L−1 benzoic acid. CONCLUSION The use of this waste material could reduce competition with food materials for ethanol production. It can be considered as an alternative sustainable waste management option. © 2013 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

In this review, the recent advancements and technical challenges associated with the production of ethanol, butanol, and isobutanol via bioconversion routes from celluloses of woody materials are reviewed. Physicochemical processes, e.g. steam explosion, seem to be the most viable process for pretreating woody materials. Although enzymatic hydrolysis is selective, it is rather a slow process. Acid hydrolysis is a relatively fast process with a high yield, but it produces inhibitory compounds of fermentation, which necessitates a detoxification process before the fermentation. Presently, the major challenges in the production of ethanol, butanol, and isobutanol via biological conversions are the rather low production yield and the sensitivity of microorganisms to the presence of inhibitors and products in fermentation media. In this study, the recent advancements in the applications of Saccharomyces cerevisiae, Clostridium acetobutylicum, and Corynebacterium glutamicum, the most promising microorganisms, for ethanol, butanol, and isobutanol production are also discussed. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29: 297-310, 2013 [ABSTRACT FROM AUTHOR]