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Black soldier fly larvae (BSFL) are considered important organisms, utilized as tools to transform waste including manure into valuable products. The growth and cultivation of BSFL are influenced by various factors, such as the presence of toxic substances in the feed and parasites. These factors play a crucial role in hormesis, and contributing to regulate these contaminants hermetic doses to get sustainable byproducts. This review aims to understand the effects on BSFL growth and activities in the presence of compounds like organic and inorganic pollutants. It also assesses the impact of microbes on BSFL growth and explores the bioaccumulation of pharmaceutical compounds, specifically focusing on heavy metals, pesticides, pharmaceuticals, indigenous bacteria, insects, and nematodes. The review concludes by addressing knowledge gaps, proposing future biorefineries, and offering recommendations for further research.

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Lignocellulosic biomass is widely available in the world. However, a consensus has yet to be established to evaluate the biomass valorization alternatives. The chemical composition is the primary technical limitation in selecting a transformation route to obtain value-added products. In this paper, the bagasse from non-centrifuged sugar (NCS) production and Pinus patula (PP) wood chips were analyzed in terms of complete chemical composition to establish their potential for selecting the transformation routes. A strategy to select the best route based on the chemical composition was applied and a feedstock criteria model was proposed. Schemes were obtained and compared using a bioprocess selection strategy proposed in previous works. As a result, the preliminary biorefinery schemes were finally defined. The assessment of schemes derived from the outlined strategy included technical, economic, environmental, and social analyses. The environmental evaluation was complemented with a geolocation assessment, revealing a 0.75-ton CO2-eq/yr contribution to the carbon footprint for local distribution. The sustainability index for the PP biorefinery and the bagasse from NCS production was analyzed, resulting in indices of 44.8 and 60.9, respectively. These values were primarily derived from the economic and environmental analyses of both processes.

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A plantain pseudostem was harvested and processed on the same day. The process began with manually separating the sheaths (80.85%) and the core (19.14%). The sheaths were subjected to a mechanical shredding process using paddles, extracting 2.20% of lignocellulosic fibers and 2.12% of sap, compared to the fresh weight of the sheaths. The fibers were washed, dried, combed, and spun in their native state and subjected to a steam explosion treatment, while the sap was subjected to filtration and evaporation. In the case of the core, it was subjected to manual cutting, drying, grinding, and sieving to separate 12.81% of the starch and 6.39% of the short lignocellulosic fibers, compared to the fresh weight of the core. The surface modification method using steam explosion succeeded in removing a low proportion of hemicellulose and lignin in the fibers coming from the shims, according to what was shown by Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetric Analysis (TGA), and Differential Scanning Calorimetry (DSC), achieving increased σmax and ε from the tensile test and greater thermal stability compared to its native state. The sap presented hygroscopic behavior by FT-IR and the highest thermal stability from TGA, while the starch from the core presented the lowest hygroscopic character and thermal stability. Although the pseudostem supplied two types of fibers, lower lignin content was identified in those from the core. Finally, the yarns were elaborated by using the fibers of the sheaths in their native and steam-exploded states, identifying differences in the processing and their respective physical and mechanical properties.

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Poplar is widely used in the paper industry and accompanied by abundant branches waste, which is potential feedstock for bioethanol production. Acid-chlorite pretreatment can selectively remove lignin, thereby significantly increasing enzymatic efficiency. Moreover, lignin residues valorization via gasification-syngas fermentation can achieve higher fuel yield. Herein, environmental and economic aspects were conducted to assess technological routes, which guides further process optimization. Life cycle assessment results show that wood-based biorefineries especially coupling scenarios have significant advantages in reducing global warming potential in contrast to fossil-based automotive fuels. Normalization results indicate that acidification potential surpasses other indicators as the primary impact category. In terms of economic feasibility, coupling scenarios present better investment prospects. Bioethanol yield is the most critical factor affecting market competitiveness. Minimum ethanol selling price below ethanol international market price is promising with higher-levels technology. Further work should be focused on technological breakthrough, consumable reduction or replacement.

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Lignocellulose biomasses (LCB), including spent mushroom substrate (SMS), pose environmental challenges if not properly managed. At the same time, these renewable resources hold immense potential for biofuel and chemicals production. With the mushroom market growth expected to amplify SMS quantities, repurposing or disposal strategies are critical. This study explores the use of SMS for cultivating microbial communities to produce carbohydrate-active enzymes (CAZymes). Addressing a research gap in using anaerobic digesters for enriching microbiomes feeding on SMS, this study investigates microbial diversity and secreted CAZymes under varied temperatures (37 °C, 50 °C, and 70 °C) and substrates (SMS as well as pure carboxymethylcellulose, and xylan). Enriched microbiomes demonstrated temperature-dependent preferences for cellulose, hemicellulose, and lignin degradation, supported by thermal and elemental analyses. Enzyme assays confirmed lignocellulolytic enzyme secretion correlating with substrate degradation trends. Notably, thermogravimetric analysis (TGA), coupled with differential scanning calorimetry (TGA-DSC), emerged as a rapid approach for saccharification potential determination of LCB. Microbiomes isolated at mesophilic temperature secreted thermophilic hemicellulases exhibiting robust stability and superior enzymatic activity compared to commercial enzymes, aligning with biorefinery conditions. PCR-DGGE and metagenomic analyses showcased dynamic shifts in microbiome composition and functional potential based on environmental conditions, impacting CAZyme abundance and diversity. The meta-functional analysis emphasised the role of CAZymes in biomass transformation, indicating microbial strategies for lignocellulose degradation. Temperature and substrate specificity influenced the degradative potential, highlighting the complexity of environmental-microbial interactions. This study demonstrates a temperature-driven microbial selection for lignocellulose degradation, unveiling thermophilic xylanases with industrial promise. Insights gained contribute to optimizing enzyme production and formulating efficient biomass conversion strategies. Understanding microbial consortia responses to temperature and substrate variations elucidates bioconversion dynamics, emphasizing tailored strategies for harnessing their biotechnological potential.

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Microalgae have long been regarded as a promising solution for biological carbon abatement from the power industry, offering renewable biomass without competing for land or water resources used for food crops. In this study, we extensively examined the application of photosynthetic microorganisms for closing carbon, nitrogen, and micronutrient loops in the power industry. Subsequently, we explored the bottom-up integration of algal biorefineries into power industry waste streams for increased economic benefits and reduced environmental impacts. Analysis of the available data indicated that microalgae integration with the power industry is primarily performed using flue-gas-assisted cultivation. This approach allows for carbon sequestration typically below one gram per liter per day, too low to significantly impact carbon abatement at achievable scales of microalgae cultivation. Alternative approaches are also being explored. For example, soluble bicarbonate platforms allow for higher biomass productivity and temporary carbon storage. Meanwhile, the use of ashes and waste heat and thermophilic strains can result in lower cultivation costs and better control of cultivation conditions. These approaches offer further incremental improvement to microalgae-based carbon abatement systems in the power industry but are unlikely to be an umbrella solution for carbon reduction. Consequently, in the near term, microalgae-based carbon valorization systems are likely to be limited to niche applications involving the synthesis of high-value products. For microalgae to truly transform carbon abatement processes radical improvements in both biology and engineering approaches are urgently needed.

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The circular economy is anticipated to bring a disruptive transformation in manufacturing technologies. Robust and industrial scalable microbial strains that can simultaneously assimilate and valorize multiple carbon substrates are highly desirable, as waste bioresources contain substantial amounts of renewable and fermentable carbon, which is diverse. Lignocellulosic biomass (LCB) is identified as an inexhaustible and alternative resource to reduce global dependence on oil. Glucose, xylose, and arabinose are the major monomeric sugars in LCB. However, primary research has focused on the use of glucose. On the other hand, the valorization of pentose sugars, xylose, and arabinose, has been mainly overlooked, despite possible assimilation by vast microbial communities. The present review highlights the research efforts that have explicitly proven the suitability of arabinose as the starting feedstock for producing various chemical building blocks via biological routes. It begins by analyzing the availability of various arabinose-rich biorenewable sources that can serve as potential feedstocks for biorefineries. The subsequent section outlines the current understanding of arabinose metabolism, biochemical routes prevalent in prokaryotic and eukaryotic systems, and possible products that can be derived from this sugar. Further, currently, exemplar products from arabinose, including arabitol, 2,3-butanediol, 1,2,3-butanetriol, ethanol, lactic acid, and xylitol are discussed, which have been produced by native and non-native microbial strains using metabolic engineering and genome editing tools. The final section deals with the challenges and obstacles associated with arabinose-based production, followed by concluding remarks and prospects.

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The next milestone of synthetic biology research relies on the development of customized microbes for specific industrial purposes. Metabolic pathways of an organism, for example, depict its chemical repertoire and its genetic makeup. If genes controlling such pathways can be identified, scientists can decide to enhance or rewrite them for different purposes depending on the organism and the desired metabolites. The lignocellulosic biorefinery has achieved good progress over the past few years with potential impact on global bioeconomy. This principle aims to produce different bio-based products like biochemical(s) or biofuel(s) from plant biomass under microbial actions. Meanwhile, yeasts have proven very useful for different biotechnological applications. Hence, their potentials in genetic/metabolic engineering can be fully explored for lignocellulosic biorefineries. For instance, the secretion of enzymes above the natural limit (aided by genetic engineering) would speed-up the down-line processes in lignocellulosic biorefineries and the cost. Thus, the next milestone would greatly require the development of synthetic yeasts with much more efficient metabolic capacities to achieve basic requirements for particular biorefinery. This review gave comprehensive overview of lignocellulosic biomaterials and their importance in bioeconomy. Many researchers have demonstrated the engineering of several ligninolytic enzymes in heterologous yeast hosts. However, there are still many factors needing to be well understood like the secretion time, titter value, thermal stability, pH tolerance, and reactivity of the recombinant enzymes. Here, we give a detailed account of the potentials of engineered yeasts being discussed, as well as the constraints associated with their development and applications.

Metabolic pathways of an organism depict its chemical repertoire and its genetic makeup.Autonomous synthetic microbes can be developed for lignocellulose biorefinery (LCB).LCBs can be harnessed with synthetic microbes to boost global bioeconomy.Yeasts can be engineered to enhance downstream process of LCB.

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This work shows the potential of a new way of co-treatment of domestic wastewater (DWW) and a liquid stream coming from the thermal hydrolysis of the organic fraction of municipal solid waste (OFMSW) mediated by a mixed culture of purple phototrophic bacteria (PPB) capable of assimilating carbon and nutrients from the medium. The biological system is an open single-step process operated under microaerophilic conditions at an oxidative reduction potential (ORP) < 0 mV with a photoperiod of 12/24 h and fed during the light stage only so the results can be extrapolated to outdoor open pond operations by monitoring the ORP. The effluent mostly complies with the discharge values of the Spanish legislation in COD and p-values (<125 mg/L; <2 mg/L), respectively, and punctually on values in N (<15 mg/L). Applying an HRT of 3 d and a ratio of 100:7 (COD:N), the presence of PPB in the mixed culture surpassed 50% of 16S rRNA gene copies, removing 78% of COD, 53% of N, and 66% of P. Furthermore, by increasing the HRT to 5 d, removal efficiencies of 83% of COD, 65% of N, and 91% of P were achieved. In addition, the reactors were further operated in a membrane bioreactor, thus separating the HRT from the SRT to increase the specific loading rate. Very satisfactory removal efficiencies were achieved by applying an HRT and SRT of 2.3 and 3 d, respectively: 84% of COD, 49% of N, and 93% of P despite the low presence of PPB due to more oxidative conditions, which step-by-step re-colonized the mixed culture until reaching >20% of 16S rRNA gene copies after 49 d of operation. These results open the door to scaling up the process in open photobioreactors capable of treating urban wastewater and municipal solid waste in a single stage and under microaerophilic conditions by controlling the ORP of the system.

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BACKGROUND: Traditional bioethanol fermentation industries are not operated under strict sterile conditions and are prone to microbial contamination. Lactic acid bacteria (LAB) are often pervasive in fermentation tanks, competing for nutrients and producing inhibitory acids that have a negative impact on ethanol-producing yeast, resulting in decreased yields and stuck fermentations. Antibiotics are frequently used to combat contamination, but antibiotic stewardship has resulted in a shift to alternative antimicrobials. RESULTS: We demonstrate that endolysin LysMP, a bacteriophage-encoded peptidoglycan hydrolase, is an effective method for controlling growth of LAB. The LysMP gene was synthesized based on the prophage sequence in the genome of Limosilactobacillus fermentum KGL7. Analysis of the recombinant enzyme expressed in E. coli and purified by immobilized metal chelate affinity chromatography (IMAC) showed an optimal lysis activity against various LAB species at pH 6, with stability from pH 4 to 8 and from 20 to 40 °C up to 48 h. Moreover, it retains more than 80% of its activity at 10% ethanol (v/v) for up to 48 h. When LysMP was added at 250 µg/mL to yeast corn mash fermentations containing L. fermentum, it reduced bacterial load by at least 4-log fold compared to the untreated controls and prevented stuck fermentation. In comparison, untreated controls with contamination increased from an initial bacterial load of 1.50 × 107 CFU/mL to 2.25 × 109 CFU/mL and 1.89 × 109 CFU/mL after 24 h and 48 h, respectively. Glucose in the treated samples was fully utilized, while untreated controls with contamination had more than 4% (w/v) remaining at 48 h. Furthermore, there was at least a fivefold reduction in lactic acid (0.085 M untreated contamination controls compared to 0.016 M treated), and a fourfold reduction in acetic acid (0.027 M untreated contamination controls vs. 0.007 M treated), when LysMP was used to treat contaminated corn mash fermentations. Most importantly, final ethanol yields increased from 6.3% (w/v) in untreated contamination samples to 9.3% (w/v) in treated contamination samples, an approximate 50% increase to levels comparable to uncontaminated controls 9.3% (w/v). CONCLUSION: LysMP could be a good alternative to replace antibiotics for mitigation of LAB contamination in biofuel refineries.

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Xylooligosaccharides (XOS) are nondigestible compounds of great interest for food and pharmaceutical industries due to their beneficial prebiotic, antibacterial, antioxidant, and antitumor properties. The market size of XOS is increasing significantly, which makes its production from lignocellulosic biomass an interesting approach to the valorization of the hemicellulose fraction of biomass, which is currently underused. This review comprehensively discusses XOS production from lignocellulosic biomass, aiming at its application in integrated biorefineries. A bibliometric analysis is carried out highlighting the main players in the field. XOS production yields after different biomass pretreatment methods are critically discussed using Microsoft PowerBI® (2.92.706.0) software, which involves screening important trends for decision-making. Enzymatic hydrolysis and the major XOS purification strategies are also explored. Finally, the integration of XOS production into biorefineries, with special attention to economic and environmental aspects, is assessed, providing important information for the implementation of biorefineries containing XOS in their portfolio.

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The goal of neutrality in greenhouse gas emissions has intensified the search for renewable fuels. However, it is crucial to ensure sustainability of new technologies before proposing their implementation. This study proposes the use of life-cycle assessment (LCA) as an intermediary tool to identify critical hotspots in the exploration of hydrothermal pretreatment of lignocellulosic biomass, followed by biochemical methane potential assessment. Brewer s spent grain (BSG) was investigated, and laboratory-scale results were applied in an attributional assessment model with business-as-usual serving as the baseline. The LCA revealed that assumptions made in the lab could pose limitations. In Brazil, the two-stage co-digestion of pretreated hydrothermal BSG showed promising prospects, with a reduction to a new value of -54 kg CO2-eq Ton-1 BSG compared to 90 kg CO2-eq Ton-1 BSG in the business-as-usual scenario. Within the top ten global beer producing countries, only Brazil and Spain demonstrated potential for exploring this proposal.

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Lignocellulosic wastes are valuable feedstock in biorefinery thanks to their high sugars content and low level of fibers intricacy. However, their massification is often a limiting parameter in the development of industrial projects. Hence, this study aims to develop an efficient process enabling the conversion of several waste streams within the same process line. Several pretreatment and enzymatic hydrolysis parameters were firstly evaluated with Old Corrugated Cardboards (OCC) as a model substrate. A chemical free pretreatment followed by an enzymatic hydrolysis (Cellic Ctec 3 enzymatic cocktail at 0.06 g of cocktail per g of Total Sugars (TS)) efficiently depolymerized OCC into monomeric sugars (0.50 g/gTS) consequently fermented into ethanol (0.24 g/gTS). Then, the suitability of this process was validated for sugars production from Pulp and Paper (P&P) sludge (0.48 g/gTS), sieved toilets papers (0.40 g/gTS), the Organic fraction of municipal solid waste (0.37 g/gTS) and Waste Wood B (0.08 g/gTS).

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Valerolactam (VL) is an important precursor chemical for nylon-5 and nylon 6,5. It has been produced by petroleum-based route involving harsh reaction conditions and generating toxic wastes. Here, we report the complete biosynthesis of VL by metabolically engineered Corynebacterium glutamicum overproducing L-lysine. The pathway comprising L-lysine monooxygenase (davB) and 5-aminovaleramide amidohydrolase (davA) from Pseudomonas putida, and ß-alanine CoA transferase (act) from Clostridium propionicum was introduced into the C. glutamicum GA16 strain. To increase the VL flux, competitive pathways predicted from sRNA knockdown target screening were deleted. This engineered C. glutamicum strain produced VL as a major product, but still secreted significant amount of its precursor, 5-aminovaleric acid (5AVA). To circumvent this problem, putative 5AVA transporter genes were screened and engineered in the genome, thereby reuptaking 5AVA excreted. Also, multiple copies of the act gene were integrated into the genome to strengthen the conversion of 5AVA to VL. The final VL10 (pVL1) strain was constructed by enhancing glucose uptake system, which produced 9.68 g/L of VL in flask culture. Fed-batch fermentation of the VL10 (pVL1) strain produced 76.1 g/L of VL from glucose with the yield and productivity of 0.28 g/g and 0.99 g/L/h, respectively, showcasing a high potential for bio-based production of VL from renewable resources.

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The microalgae Chlorella saccharophila UTEX247 was co-cultured with its symbiotic indigenous isolated bacterial strain, Exiguobacterium sp., to determine the possible effects of bacteria on microalgae growth and lutein productivity. Under optimal conditions, the lutein productivity of co-culture was 298.97 µg L-1 d-1, which was nearly 1.45-fold higher compared to monocultures i.e., 103.3 µg L-1 d-1. The highest lutein productivities were obtained in co-cultures, accompanied by a significant increase in cell biomass up to 0.84-fold. These conditions were analyzed using an untargeted metabolomics approach to identify metabolites enhancing valuable renewables, i.e., lutein, without compromising growth. Our qualitative metabolomic analysis identified nearly 30 (microalgae alone), 41 (bacteria alone), and 75 (co-cultures) metabolites, respectively. Among these, 46 metabolites were unique in the co-culture alone. The co-culture interactions significantly altered the role of metabolites such as thiamine precursors, reactive sugar anomers like furanose and branched-chain amino acids (BCAA). Nevertheless, the central metabolism cycle upregulation depicted increased availability of carbon skeletons, leading to increased cell biomass and pigments. In conclusion, the co-cultures induce the production of relevant metabolites which regulate growth and lutein simultaneously in C. saccharophila UTEX247, which paves the way for a new perspective in microalgal biorefineries.

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Second-generation biorefineries (2GBR) represent an innovative application of bioresources technologies to produce bioenergy and valuable products. This paper aims to introduce and analyze the joint production of bioethanol and ethyl lactate in a 2GBR. Techno-economic and profitability perspectives are considered in the analysis which is conducted via simulation considering corn stover as raw material. A key aspect in the analysis is a joint production parameter named α, whose values can dictate either the sole production of bioethanol (α = 0), joint production (0 < α < 1), or the unique production of ethyl lactate (α = 1). In other words, the proposed joint production scheme provides versatility in production. Simulations show that the lowest Total Capital Investment, Unit Production Cost, and Operating Cost values were associated with low values of α. Furthermore, when α ≥ 0.4, the 2GBR under study can achieve internal rates of return above 30%, which implies that the project offers a potentially high profitability.

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Basidiomycetes are renowned as highly effective decomposers of plant materials, due to their extensive array of oxidative enzymes, which enable them to efficiently break down complex lignocellulosic biomass structures. Among the oxidative machinery of industrially relevant basidiomycetes, the role of lytic polysaccharide monooxygenases (LPMO) in lignocellulosic biomass deconstruction is highlighted. So far, only a limited number of basidiomycetes LPMOs have been identified and heterologously expressed. These LPMOs have presented activity on cellulose and hemicellulose, as well as participation in the deconstruction of lignin. Expanding on this, the current review proposes both enzymatic and non-enzymatic mechanisms of LPMOs for biomass conversion, considering the significance of the Carbohydrate-Binding Modules and other C-terminal regions domains associated with their structure, which is involved in the deconstruction of lignocellulosic biomass.

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The greener chemical and enzymatic pretreatments for lignocellulosic biomasses are portraying a crucial role owing to their recalcitrant nature. Traditional pretreatments lead to partial degradation of lignin and hemicellulose moieties from the pretreated biomass. But it still restricts the enzyme accessibility for the digestibility towards the celluloses and the interaction of lignin-enzymes, nonproductively. Moreover, incursion of certain special chemical treatments and other lignin sulfonation techniques to the enzymatic pretreatment (hybrid enzymatic pretreatment) enhances the lignin structural modification, solubilization of the hemicelluloses and both saccharification and fermentation processes (SAF). This article concentrates on recent developments in various chemical and hybrid enzymatic pretreatments on biomass materials with their mode of activities. Furthermore, the issues on strategies of the existing pretreatments towards their industrial applications are highlighted, which could lead to innovative ideas to overcome the challenges and give guideline for the researchers towards the lignocellulosic biorefineries.

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The ability of modern agriculture to meet future food demand imposed by accelerating growth of the world's population is a major challenge, and fertilizers play a key role by replacing nutrients in agricultural soil. Given the need for fertilizers, their cost in nonrenewable resources and energy, and the consequences of the greenhouse gas emissions required to make them, people have begun to explore ways to make fertilizer manufacturing and use more sustainable. Using data from the CAS Content Collection, this review examines and analyzes the academic and patent literature on sustainable fertilizers from 2001 to 2021. The breakdown of journal and patent literature publication over time on this topic, country or region of publications, the substances included in published research, among other things allow us to understand the general progress in the field as well as the classes of materials and concepts driving innovation. We hope that this bibliometric analysis and literary review will assist researchers in relevant industries to discover and implement ways to supplement conventional fertilizers and nutrient sources while improving the efficiency and sustainability of waste management and ammonia production.

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The ethanol-induced precipitation after enzymatic hydrolysis commonly used for sulfated polysaccharide extraction from marine resources wastes a large amount of proteins. Here, possible extraction of fish protein hydrolysates (FPH) from the ethanol residue of sulfated polysaccharide precipitation from head, bone, and skin of skipjack tuna is investigated. Antioxidant, antibacterial, angiotensin I-converting enzyme (ACE) inhibitory activities and functional properties of the recovered FPHs are also evaluated. A degree of hydrolysis of 40.93, 38.13, and 37.23 is achieved for FPH from head, bone, and skin, respectively. FPH from the head presents the highest antioxidant and ACE inhibitory activity as well as foam/emulsion capacity among all the FPHs. The FPHs are all able to inhibit three Gram-positive bacteria and three Gram-negative bacteria to varying degrees and have a water solubility >65%. Altogether, the results demonstrate great potential for recovery of bioactive/functional peptides from the residue of sulfated polysaccharide extraction process enabling efficient biorefining of aquatic resources.