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The rising climate change concerns over the excessive exploitation of non-renewable sources have necessitated the need for alternative renewable and eco-friendly resources for the production of innovative materials, achieving the targets of bioeconomy. Lignocellulosic biomass (LB) constituted by polymeric sugars and lignin is an abundantly available plant-based renewable material in the form of agro-industrial food waste and crop residues that can be exploited for the production of an array of value-added chemicals and bioproducts. Cellulose is the most abundant natural and biodegradable organic polymer on earth derived from LB, with wide scale applications in the lignocellulosic biorefineries and food industries. The negative effects of food waste from agro-industrial activities could be reduced through the recovery of cellulose from these wastes and converting it into valuable forms. However, the extraction of cellulose from LB is a difficult task owing to the recalcitrant nature of biomass that restricts the easy accessibility of cellulose for value addition. Therefore, a suitable cellulose extraction method through the fractionation of LB is necessary for a better cellulose yield. Furthermore, owing to the enormous potential of nanocellulose (NC), researchers are keenly interested in developing ecologically acceptable cellulose extraction methods. Cellulose nanofibrils and nanocrystals confer excellent mechanical properties, non-toxic characteristics and biodegradability, due to which they possess wide-scale applications in diverse industrial sectors. The current review emphasizes the potential role of cellulose extraction and NC production from agro-food waste. The different pretreatment methods for their extraction from LB are outlined. The applications of nanocellulose in different areas are also discussed. The review also highlights the recent trends, challenges and future directions in the development of cellulose and NC-based commercial products.

Bioactive peptides derived from fish the byproduct protein hydrolysate have wide potential as functional food ingredients. The preparation of bioactive peptides is commonly achieved via enzymatic hydrolysis; this is the most preferred method because it has high specificity, fewer residual organic solvents in the product, and it is usually carried out in mild conditions. The use of various enzymes such as proteases is widely practiced in the industry, yet there are various limitations as it is of high cost and there is a limited availability of food-grade enzymes in the market. Moreover, high-throughput purification and the identification analysis of these peptides are currently being studied to further understand the functionality and characterization of the bioactive peptides. This review mainly focuses on the novel bioactive peptides derived from fish protein hydrolysates from various fish wastes and byproducts. The hydrolysis conditions, source of hydrolysate, and amino acid sequence of these novel peptides are presented, along with their corresponding methods of analysis in purification and identification. The use of various enzymes yields novel peptides with potent bioactivities, such as antiproliferative, antimicrobial, antihypertensive, antiglycemic, antitumor, and antioxidative biological functions. The increasing interest in proteomics in marine and aquatic waste utilization continues due to these products’ bioactivity and sustainability.

The urgent demand for alternative energy sources has been sparked by the tremendous burden on fossil fuels and the resulting acute energy crisis and climate change issues. Lignocellulosic biomass is a copious renewable and alternative bioresource for the generation of energy fuels and biochemicals in biorefineries. Different pretreatment strategies have been established to overcome biomass recalcitrance and face technological challenges, such as high energy consumption and operational costs and environmental hazards, among many. Biological pretreatment using microbial enzymes is an environmentally benign and low-cost method that holds promising features in the effective pretreatment of lignocellulosic biomass. Due to their versatility and eco-friendliness, cellulases, hemicellulases, and ligninolytic enzymes have been recognized as “green biocatalysts” with a myriad of industrial applications. The current review provides a detailed description of different types of lignocellulolytic enzymes, their mode of action, and their prospective applications in the valorization of lignocellulosic biomass. Solid state fermentation holds great promise in the microbial production of lignocellulolytic enzymes owing to its energy efficient, environment friendly, and higher product yielding features utilizing the lignocellulosic feedstocks. The recent trends in the application of enzyme immobilization strategies for improved enzymatic catalysis have been discussed. The major bottlenecks in the bioprocessing of lignocellulosic biomass using microbial enzymes and future prospects have also been summarized.

An upsurge in global population and rapid urbanization has accelerated huge dependence on petroleum-derived fuels and consequent environmental concerns owing to greenhouse gas emissions in the atmosphere. An integrated biorefinery uses lignocellulosic feedstock as raw material for the production of renewable biofuels, and other fine chemicals. The sustainable bio-economy and the biorefinery industry would benefit greatly from the effective use of lignocellulosic biomass obtained from agricultural feedstocks to replace petrochemical products. Lignin, cellulose, hemicellulose, and other extractives, which are essential components of lignocellulosic biomass, must be separated or upgraded into useful forms in order to fully realize the potential of biorefinery. The development of low-cost and green pretreatment technologies with effective biomass deconstruction potential is imperative for an efficient bioprocess. The abundance of microorganisms along with their continuous production of various degradative enzymes makes them suited for the environmentally friendly bioconversion of agro-industrial wastes into viable bioproducts. The present review highlights the concept of biorefinery, lignocellulosic biomass, and its valorization by green pretreatment strategies into biofuels and other biochemicals. The major barriers and challenges in bioconversion technologies, environmental sustainability of the bioproducts, and promising solutions to alleviate those bottlenecks are also summarized.

The grave environmental, social, and economic concerns over the unprecedented exploitation of non-renewable energy resources have drawn the attention of policy makers and research organizations towards the sustainable use of agro-industrial food and crop wastes. Enzymes are versatile biocatalysts with immense potential to transform the food industry and lignocellulosic biorefineries. Microbial enzymes offer cleaner and greener solutions to produce fine chemicals and compounds. The production of industrially important enzymes from abundantly present agro-industrial food waste offers economic solutions for the commercial production of value-added chemicals. The recent developments in biocatalytic systems are designed to either increase the catalytic capability of the commercial enzymes or create new enzymes with distinctive properties. The limitations of low catalytic efficiency and enzyme denaturation in ambient conditions can be mitigated by employing diverse and inexpensive immobilization carriers, such as agro-food based materials, biopolymers, and nanomaterials. Moreover, revolutionary protein engineering tools help in designing and constructing tailored enzymes with improved substrate specificity, catalytic activity, stability, and reaction product inhibition. This review discusses the recent developments in the production of essential industrial enzymes from agro-industrial food trash and the application of low-cost immobilization and enzyme engineering approaches for sustainable development.

Growth in population and thereby increased industrialization to meet its requirement, has elevated significantly the demand for energy resources. Depletion of fossil fuel and environmental sustainability issues encouraged the exploration of alternative renewable eco-friendly fuel resources. Among major alternative fuels, bio-ethanol produced from lignocellulosic biomass is the most popular one. Lignocellulosic biomass is the most abundant renewable resource which is ubiquitous on our planet. All the plant biomass is lignocellulosic which is composed of cellulose, hemicellulose and lignin, intricately linked to each other. Filamentous fungi are known to secrete a plethora of biomass hydrolyzing enzymes. Mostly these enzymes are inducible, hence the fungi secrete them economically which causes challenges in their hyperproduction. Biomass’s complicated structure also throws challenges for which pre-treatments of biomass are necessary to make the biomass amorphous to be accessible for the enzymes to act on it. The enzymatic hydrolysis of biomass is the most sustainable way for fermentable sugar generation to convert into ethanol. To have sufficient ethanol concentration in the broth for efficient distillation, high solid loading >20% of biomass is desirable and is the crux of the whole technology. High solid loading offers several benefits including a high concentration of sugars in broth, low equipment sizing, saving cost on infrastructure, etc. Along with the benefits, several challenges also emerged simultaneously, like issues of mass transfer, low reaction rate due to water constrains in, high inhibitor concentration, non-productive binding of enzyme lignin, etc. This article will give an insight into the challenges for cellulase action on cellulosic biomass at a high solid loading of biomass and its probable solutions.

Ethyl esters of omega-3 fatty acids are active pharmaceutical ingredients used for the reduction in triglycerides in the treatment of hyperlipidemia. Herein, an ultrasonic packed-bed bioreactor was developed for continuous production of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) ethyl esters from DHA+EPA concentrate and ethyl acetate (EA) using an immobilized lipase, Novozym® 435, as a biocatalyst. A three-level–two-factor central composite design combined with a response surface methodology (RSM) was employed to evaluate the packed-bed bioreactor with or without ultrasonication on the conversion of DHA + EPA ethyl ester. The highest conversion of 99% was achieved with ultrasonication at the condition of 1 mL min−1 flow rate and 100 mM DHA + EPA concentration. Our results also showed that the ultrasonic packed-bed bioreactor has a higher external mass transfer coefficient and a lower external substrate concentration on the surface of the immobilized enzyme. The effect of ultrasound was also demonstrated by a kinetic model in the batch reaction that the specificity constant (V′max/K2) in the ultrasonic bath was 8.9 times higher than that of the shaking bath, indicating the ultrasonication increased the affinity between enzymes and substrates and, therefore, increasing reaction rate. An experiment performed under the highest conversion conditions showed that the enzyme in the bioreactor remained stable at least for 5 days and maintained a 98% conversion.

Routine maintenance of fishing vessels and wastewater discharges are primary sources of heavy metals in fishing ports. Sediment pollution assessment is necessary in fishing port management, including sediment dredging and disposal, sewage treatment facility construction, and pollution source control. In this study, sediment heavy metal contents in Qianzhen Fishing Port, the largest pelagic fishery port in Taiwan, were investigated to assess the contamination levels and related potential ecological risks using multiple sediment pollution indices. Normalization methods were applied to identify the potential sources of heavy metals in fishing port sediments. Results showed that Cu, Zn, Pb, and Cr contents in the sediments of the inner fishing port (averages of 276, 742, 113, and 221 mg/kg, respectively) were 3–5 times greater compared to those along the port entrance and outside, indicating the strong impacts of anthropogenic pollution (EFCu: 5.6–12.5; EFZn: 2.8–4.3; EFPb: 2.4–5.4; EFCr: 1.1–3.2). Copper pollution was more severe, with high maxima contamination factor (CFCu: 15.1–24.8), probably contributed by copper-based antifouling paints used in fishing vessels. The sediments in the inner fishing port are categorized as having considerable ecological risk and toxicity (mERMq: 0.61–0.91; ΣTU: 7.5–11.7) that can potentially cause adverse effects on benthic organisms. Qianzhen Fishing Port sediments can be characterized as high Cu/Fe and Pb/Fe, moderate Zn/Fe, and high total grease content, indicating that the potential sources of heavy metals are primarily antifouling paints and oil spills from the fishing vessels. This study provides valuable data for pollution control, remediation, and environmental management of fishing ports.

Impairment of adiponectin production and function is closely associated with insulin resistance and type 2 diabetes, which are linked to obesity. Studies in animal models have documented the anti-diabetic effects of tetrahydrocurcumin (THC). Although several possible mechanisms have been proposed, the contribution of adiponectin signaling on THC-mediated antihyperglycemic effects remains unknown. Here, we report that adiposity, steatosis, and hyperglycemia were potently attenuated in high-fat diet/streptozotocin-induced diabetic obese mice after they received 20 and 100 mg/kg THC for 14 weeks. THC upregulated UCP-1 in adipose tissue and elevated adiponectin levels in the circulation. THC upregulated the AdipoR1/R2-APPL1-mediated pathway in the liver and skeletal muscle, which contributes to improved insulin signaling, glucose utilization, and lipid metabolism. Furthermore, THC treatment significantly (p < 0.05) preserved islet mass, reduced apoptosis, and restored defective insulin expression in the pancreatic β-cells of diabetic obese mice, which was accompanied by an elevation of AdipoR1 and APPL1. These results demonstrated a potential mechanism underlying the beneficial effects of THC against hyperglycemia via the adiponectin-AdipoR pathway, and thus, may lead to a novel therapeutic use for type 2 diabetes.

Fish gelatin and its hydrolysates exhibit a variety of biological characteristics, which include antihypertensive and antioxidant properties. In this study, fish gelatins were extracted from extrusion-pretreated tilapia scales, and then subjected to analyses to determine the physicochemical properties and antioxidant activity of the extracted gelatins. Our findings indicate that TSG2 (preconditioned with 1.26% citric acid) possessed the greatest extraction yield, as well as higher antioxidant activities compared with the other extracted gelatins. Hence, TSG2 was subjected to further hydrolyzation using different proteases and ultrafiltration conditions, which yielded four gelatin hydrolysates: TSGH1, TSGH2, TSGH3, and TSGH4. The results showed that TSGH4 (Pepsin + Pancreatin and ultrafiltration < 3000 Da) had a higher yield and greater antioxidant activity in comparison with the other gelatin hydrolysates. As such, TSGH4 was subjected to further fractionation using a Superdex peptide column and two-stage reverse-phase column HPLC chromatography, yielding a subfraction TSGH4-6-2-b, which possessed the highest 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity compared with the other fractions. Further LC-ESI/MS/MS analysis of TSGH4-6-2-b suggested two novel peptides (GYDEY and EPGKSGEQGAPGEAGAP), which could have potential as naturally-occurring peptides with antioxidant properties. These promising results suggest that these antioxidant peptides could have applications in food products, nutraceuticals, and cosmetics.

Cobia, Rachycentron canadum, is a medium-size marine fish with emerging global potential for offshore aquaculture. The processing waste, cobia liver, is a raw material rich in polyunsaturated fatty acid oils. In this study, an environmentally friendly green process, aqueous extraction (AE), was used to extract the cobia liver oil. The effect of cooking time and substrate water ratio on the oil extractability was investigated herein. The cooking time of 15 min, and substrate water ratio of 1:2 obtained the highest extraction efficiency. However, the oil extractability was only 18.8%. Thus, enzyme-assisted aqueous extraction (EAAE) was used to increase oil extractability and recovery of protein hydrolysates. The commercial proteases—including alcalase, papain, trypsin, and pepsin—were employed in pretreated cobia liver in order to increase oil release during AE. The EAAE results showed that maximum oil extractability was 38% by papain pretreatment. EAAE greatly improved the extraction efficiency; the oil extractability was double than that of AE (18.8%). The fatty acid profiles revealed that ω-3 polyunsaturated fatty acid contents of extracted oil obtained from AE and EAAE were 21.3% and 19.5%, respectively. Besides, the cobia liver hydrolysates obtained from EAAE by alcalase, papain, pepsin, and trypsin pretreatment showed scavenge DPPH radical activity with EC50 values of 0.92, 1.03, 0.83, and 0.53 mg, respectively. After in vitro simulated gastrointestinal digestion, the protein hydrolysates exhibited scavenge DPPH radical activity with EC50 values of 1.15, 1.55, 0.98, and 0.76 mg for alcalase, papain, pepsin, and trypsin, respectively. The study showed that the EAAE process can be used for extracting fish oil from fish waste while simultaneously obtaining the protein hydrolysates with antioxidant activity.

Type II collagen is an important component of cartilage; however, little is known about its effect on skin wound healing. In this study, type II collagen was extracted from the cartilage of Acipenser baerii and its effect on in vitro and in vivo wound healing was compared to type I collagen derived from tilapia skin. Sturgeon cartilage collagen (SCC) was composed of α1 chains and with a thermal denaturation (Td) at 22.5 and melting temperature (Tm) at 72.5 °C. Coating SCC potentiated proliferation, migration, and invasion of human dermal fibroblast adult (HDFa) cells. Furthermore, SCC upregulated the gene expression of extracellular matrix (ECM) components (col Iα1, col IIIα1, elastin, and Has2) and epithelial-mesenchymal transition (EMT) molecules (N-cadherin, Snail, and MMP-1) in HDFa. Pretreatment with Akt and mitogen-activated protein kinase (MAPK) inhibitors significantly attenuated the HDFa invasion caused by SCC. In mice, the application of SCC on dorsal wounds effectively facilitated wound healing as evidenced by 40–59% wound contraction, whereas the untreated wounds were 18%. We observed that SCC reduced inflammation, promoted granulation, tissue formation, and ECM deposition, as well as re-epithelialization in skin wounds. In addition, SCC markedly upregulated the production of growth factors in the dermis, and dermal and subcutaneous white adipose tissue; in contrast, the administration of tilapia skin collagen (TSC) characterized by typical type I collagen was mainly expressed in the epidermis. Collectively, these findings indicate SCC accelerated wound healing by targeting fibroblast in vitro and in vivo.