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Riboflavin (vitamin B2) is one of the essential vitamins that the human body needs to maintain normal metabolism. Its biosynthesis has become one of the successful models for gradual replacement of traditional chemical production routes. B. subtilis is characterized by its short fermentation time and high yield, which shows a huge competitive advantage in microbial fermentation for production of riboflavin. This review summarized the advancements of regulation on riboflavin production as well as the synthesis of two precursors of ribulose-5-phosphate riboflavin (Ru5P) and guanosine 5′-triphosphate (GTP) in B. subtilis. The different strategies to improve production of riboflavin by metabolic engineering were also reviewed.

This study investigates the structural effects of dilute acid and alkali treatments on cotton fibers, aiming to understand the influence of chemical pretreatment on cellulose morphology. Cotton samples were exposed to 1% sulfuric acid and 1% sodium hydroxide at 90 °C, and the resulting changes were evaluated using scanning electron microscopy and nonlinear optical imaging techniques. The results indicate that sulfuric acid causes significant fiber degradation, leading to fragmentation and reduced fiber thickness. In contrast, sodium hydroxide treatment results in a roughened, flaky surface while preserving the overall structural integrity, with fibers appearing fluffier and more accessible to enzymatic processes. Untreated cotton fibers maintained a smooth and uniform surface, confirming the chemical specificity of the observed changes. These findings are crucial for optimizing biomass pretreatment methods, demonstrating that dilute chemical treatments primarily affect macrostructural features without significantly disrupting the cellulose microfibrils. The study provides valuable insights for the development of efficient biorefining processes and sustainable bio-based materials, highlighting the importance of selecting appropriate chemical conditions to enhance enzymatic hydrolysis and biomass conversion while maintaining the core structure of cellulose. This research contributes to advancing the understanding of cellulose’s structural resilience under mild chemical pretreatment conditions.

Oil and natural gas continue to dominate global energy consumption, though a supply gap of 2 million barrels per day (b/d) was reported in the fourth quarter of 2023. Despite a projected increase in global oil supply by 1.2 million b/d in 2023, reaching 101.1 million b/d compared to 2022, reliance on fossil fuels poses challenges for energy security and sustainability. For China, transitioning to clean and renewable energy sources is essential. Biofuel ethanol, with its high octane rating and anti-knock properties, is a promising alternative. This bioenergy sector is expanding globally, with cellulosic ethanol production emerging as a key objective. However, the high production cost of cellulosic ethanol presents a significant challenge to its large-scale adoption. To overcome this barrier, various techniques are being explored to reduce production costs. Among them, advanced characterization methods are used to monitor changes in cellulose, lignin, and hemicellulose during ethanol production in situ, quickly and without surface labeling. These methods provide insights into the factors driving high production costs, enabling targeted improvements. This review focuses on the potential of these characterization techniques to optimize ethanol production processes and improve efficiency. The findings may offer a strategic direction for scaling up cellulosic ethanol production and contribute to the sustainability of energy resources by reducing dependency on fossil fuels.

Cellulase serves as a pivotal enzymatic catalyst in the bioconversion of lignocellulosic biomass into fermentable sugars and subsequent bioproducts. However, its high cost poses a significant challenge, making the overall lignocellulosic biorefinery process economically burdensome. To mitigate this issue and enhance cost-effectiveness, it becomes imperative to employ in-house built and highly potent cellulases. This study focused on effective cellulase production by Trichoderma reesei RUT C30 and PB3 strains using solid and liquid inducers mixture with varying ratios. By optimizing the SLI mixture at a ratio of 1:5 (w/w), we successfully attained maximum cellulase production and productivity, reaching 29.5 FPU/mL and 204.8 FPU/L/h, respectively. Furthermore, this strategy yielded comparatively elevated levels of cellobiase and xylanase production, achieving 69.6 CBU/mL and 250.1 IU/mL, respectively, in contrast to the control process utilizing either solid or liquid inducers. Ultimately, hydrolysis of 10% (w/v) H 2 SO 4 -pretreated corn stover (HPCS) utilizing a crude enzyme dosage of 15 FPU/g-HPCS liberated 45.5 g/L of glucose and 18.2 g/L of xylose, underscoring the immense potential of this methodology in alleviating the cost burden associated with lignocellulosic biorefinery.

Dichlorodiphenyltrichloroethane (DDT) is one of the persistent organic pollutants (POPs) that are highly toxic to the environment. Effective evaluation on the bioavailability of DDTs in soils is essential for risk assessment and soil remediation. The aims of this study were to verify the feasibility of the hydroxypropyl-β-cyclodextrin (HPCD) extraction method for predicting the bioavailability of DDT, dichlorodiphenyldichloroethane (DDD), and dichlorodiphenyldichloroethylene (DDE) in soils, and to examine the effect of HPCD on their biodegradation in different soils. Four soils were aged with a mixture of p , p ′-DDT, o , p ′-DDT, p , p ′-DDD and p , p ′-DDE (0.25 μg g −1 for each compound) for 20 and 100 days, respectively. For each of the DDTs, a significant positive correlation between HPCD-extractable fraction and biodegradable fraction in each soil was observed. It was demonstrated that the amounts of HPCD-extractable p , p ′-DDT and o , p ′-DDT were not significantly different from the amounts that were degradable as assessed from their degradation by Enterobacter sp. LY402 ( p  > 0.05). Such 1:1 relationship between extraction and degradation was not obtained in the cases of p , p ′-DDD and p , p ′-DDE, as the amounts of degradable p , p ′-DDD and p , p ′-DDE were lower than the amounts that were extractable with HPCD. Additionally, the biodegradation of p , p ′-DDT, o , p ′-DDT, p , p ′-DDD, and p , p ′-DDE was inhibited in the presence of HPCD, which could be due to the binding of the compounds to HPCD, making them less available to access the bacteria for degradation. This study provides the possibility of using the HPCD extraction method to predict the bioavailability of p , p ′-DDT and o , p ′-DDT in soils. But when HPCD was used as an additive in the bioremediation of DDT-contaminated soils, it might have a negative effect on biodegradation.

Dichlorodiphenyltrichloroethane (DDT) is one of the persistent organic pollutants (POPs) that are highly toxic to the environment. Effective evaluation on the bioavailability of DDTs in soils is essential for risk assessment and soil remediation. The aims of this study were to verify the feasibility of the hydroxypropyl-[beta]-cyclodextrin (HPCD) extraction method for predicting the bioavailability of DDT, dichlorodiphenyldichloroethane (DDD), and dichlorodiphenyldichloroethylene (DDE) in soils, and to examine the effect of HPCD on their biodegradation in different soils. Four soils were aged with a mixture of p,p'-DDT, o,p'-DDT, p,p'-DDD and p,p'-DDE (0.25 [mu]g g.sup.-1 for each compound) for 20 and 100 days, respectively. For each of the DDTs, a significant positive correlation between HPCD-extractable fraction and biodegradable fraction in each soil was observed. It was demonstrated that the amounts of HPCD-extractable p,p'-DDT and o,p'-DDT were not significantly different from the amounts that were degradable as assessed from their degradation by Enterobacter sp. LY402 (p > 0.05). Such 1:1 relationship between extraction and degradation was not obtained in the cases of p,p'-DDD and p,p'-DDE, as the amounts of degradable p,p'-DDD and p,p'-DDE were lower than the amounts that were extractable with HPCD. Additionally, the biodegradation of p,p'-DDT, o,p'-DDT, p,p'-DDD, and p,p'-DDE was inhibited in the presence of HPCD, which could be due to the binding of the compounds to HPCD, making them less available to access the bacteria for degradation. This study provides the possibility of using the HPCD extraction method to predict the bioavailability of p,p'-DDT and o,p'-DDT in soils. But when HPCD was used as an additive in the bioremediation of DDT-contaminated soils, it might have a negative effect on biodegradation. Electronic supplementary material The online version of this article (doi:10.1007/s11270-015-2472-9) contains supplementary material, which is available to authorized users.

Organic matter (OM) plays a vital role in controlling polycyclic aromatic hydrocarbon (PAH) bioavailability in soils and sediments. In this study, both a hydroxypropyl-β-cyclodextrin (HPCD) extraction test and a biodegradation test were performed to evaluate the bioavailability of phenanthrene in seven different bulk soil/sediment samples and two OM components (humin fractions and humic acid (HA) fractions) separated from these soils/sediments. Results showed that both the extent of HPCD-extractable phenanthrene and the extent of biodegradable phenanthrene in humin fraction were lower than those in the respective HA fraction and source soil/sediment, demonstrating the limited bioavailability of phenanthrene in the humin fraction. For the source soils/sediments and the humin fractions, significant inverse relationships were observed between the sorption capacities for phenanthrene and the amounts of HPCD-extractable or biodegradable phenanthrene (p < 0.05), suggesting the importance of the sorption capacity in affecting desorption and biodegradation of phenanthrene. Strong linear relationships were observed between the amount of HPCD-extractable phenanthrene and the amount degraded in both the bulk soils/sediments and the humin fractions, with both slopes close to 1. On the other hand, in the case of phenanthrene contained in HA, a poor relationship was observed between the amount of phenanthrene extracted by HPCD and the amount degraded, with the former being much less than the latter. The results revealed the importance of humin fraction in affecting the bioavailability of phenanthrene in the bulk soils/sediments, which would deepen our understanding of the organic matter fractions in affecting desorption and biodegradation of organic pollutants and provide theoretical support for remediation and risk assessment of contaminated soils and sediments.

Issue Title: Electrochemical advanced oxidation processes for removal of toxic/persistent organic pollutants from water Organic matter (OM) plays a vital role in controlling polycyclic aromatic hydrocarbon (PAH) bioavailability in soils and sediments. In this study, both a hydroxypropyl-[beta]-cyclodextrin (HPCD) extraction test and a biodegradation test were performed to evaluate the bioavailability of phenanthrene in seven different bulk soil/sediment samples and two OM components (humin fractions and humic acid (HA) fractions) separated from these soils/sediments. Results showed that both the extent of HPCD-extractable phenanthrene and the extent of biodegradable phenanthrene in humin fraction were lower than those in the respective HA fraction and source soil/sediment, demonstrating the limited bioavailability of phenanthrene in the humin fraction. For the source soils/sediments and the humin fractions, significant inverse relationships were observed between the sorption capacities for phenanthrene and the amounts of HPCD-extractable or biodegradable phenanthrene (p<0.05), suggesting the importance of the sorption capacity in affecting desorption and biodegradation of phenanthrene. Strong linear relationships were observed between the amount of HPCD-extractable phenanthrene and the amount degraded in both the bulk soils/sediments and the humin fractions, with both slopes close to 1. On the other hand, in the case of phenanthrene contained in HA, a poor relationship was observed between the amount of phenanthrene extracted by HPCD and the amount degraded, with the former being much less than the latter. The results revealed the importance of humin fraction in affecting the bioavailability of phenanthrene in the bulk soils/sediments, which would deepen our understanding of the organic matter fractions in affecting desorption and biodegradation of organic pollutants and provide theoretical support for remediation and risk assessment of contaminated soils and sediments.

Vertical transistors have attracted enormous attention in the next-generation electronic devices due to their high working frequency, low operation voltage and large current density, while a major scientific and technological challenge for high performance vertical transistor is to find suitable source electrode. Herein, an MXene material, Ti 3 C 2 T x , is introduced as source electrode of organic vertical transistors. The porous MXene films take the advantage of both partially shielding effect of graphene and the direct modulation of the Schottky barrier at the mesh electrode, which significantly enhances the ability of gate modulation and reduces the subthreshold swing to 73 mV/dec. More importantly, the saturation of output current which is essential for all transistor-based applications but remains a great challenge for vertical transistors, is easily achieved in our device due to the ultra-thin thickness and native oxidation of MXene, as verified by finite-element simulations. Finally, our device also possesses great potential for being used as wide-spectrum photodetector with fast response speed without complex material and structure design. This work demonstrates that MXene as source electrode offers plenty of opportunities for high performance vertical transistors and photoelectric devices. The modulation of Schottky barrier, which dominates the carrier injection in vertical organic field-effect transistors, strongly depends on the source electrode. Here, Chen et al. utilize MXene as a source electrode, achieving a subthreshold swing down to 73 mv/dec and a large gate control ability.

Realizing multi-modal information recognition tasks which can process external information efficiently and comprehensively is an urgent requirement in the field of artificial intelligence. However, it remains a challenge to achieve simple structure and high-performance multi-modal recognition demonstrations owing to the complex execution module and separation of memory processing based on the traditional complementary metal oxide semiconductor (CMOS) architecture. Here, we propose an efficient sensory memory processing system (SMPS), which can process sensory information and generate synapse-like and multi-wavelength light-emitting output, realizing diversified utilization of light in information processing and multi-modal information recognition. The SMPS exhibits strong robustness in information encoding/transmission and the capability of visible information display through the multi-level color responses, which can implement the multi-level pain warning process of organisms intuitively. Furthermore, different from the conventional multi-modal information processing system that requires independent and complex circuit modules, the proposed SMPS with unique optical multi-information parallel output can realize efficient multi-modal information recognition of dynamic step frequency and spatial positioning simultaneously with the accuracy of 99.5% and 98.2%, respectively. Therefore, the SMPS proposed in this work with simple component, flexible operation, strong robustness, and highly efficiency is promising for future sensory-neuromorphic photonic systems and interactive artificial intelligence. Multimodal cognitive computing task is an important research content in the field of AI. Here, the authors propose an efficient sensory memory processing system, which can process sensory information and generate synapse-like and multiwavelength light-emitting output for efficient multimodal information recognition.