Global Change Biology Bioenergy最新文献

Altering plant carbon allocation from leaves to stems is key to improve biomass for forage, fuel, and renewable chemicals. The sorghum dry stalk (D) locus controls a quantitative trait for sugar accumulation, with enhanced carbon allocation in the stems of juicy green (dd) sorghum but reduced carbon allocation in that of dry white (DD) sorghum. However, it remains unclear whether altering sorghum sugar accumulation in stem affects below-ground microbiome. Here we investigated sorghum rhizosphere soil microbiome in near isogenic lines with different magnitude of carbon allocations and accumulation in the stems. Results showed that enhanced carbon accumulation in stems of juicy green sorghum results in stronger selection in rhizosphere microbiome assembly. The rhizosphere soil microbial communities selected in juicy green sorghum tended to be fast-growing microbial taxa which possessed potential functions that would promote higher potential capacity to use chemically labile carbon sources and potentially result in higher potential decomposition rates. We found the rhizosphere microbes selected by juicy green sorghum form weaker interactions than dry white sorghum. This is the first comprehensive study revealing how the different magnitude of carbon allocations to stems regulates microbial community assembly, microbial interaction, and microbial functions. This study indicates that future plant modification for bioenergy crops should also consider the impacts on belowground microbial community without compromising the sustainability.

The Energy Return On Investment (EROI) is a recognised indicator for assessing the relevance of an energy project in terms of net energy delivered to society. For woody biomass divergences remain on the right methodology to assess the EROI leading to large variations in the published estimates. This article presents an in-depth discussion about the EROI of woody biomass in three different forms: woodchips, pellets and liquid fuels. The conceptualisation of EROI is further developed to reach a consistent definition for biomass post-processed fuels. It considers, on top of the external energy investments, the grey energy associated with the energy used to enrich the fuel. With the proposed methodology, all woodchips have an EROI of the same order of magnitude, between 20 and 37, depending on forestry types, operations and machineries. For secondary residues, the first estimate is 170 if, as co-products, no energy investment is allocated to the forestry operations and transport. On the basis of a mass allocation for forestry operations and transport, the EROI for secondary residues becomes of the same order of magnitude as that for wood chips. Woodchips can be further post-processed into pellets or liquid fuels. Pellets have an EROI of 4–7 if the heat is externally supplied and 8–23 if internally supplied (self-consumption of part of the raw material). Liquid fuels derived from primary wood and residues through gasification and Fischer-Tropsch synthesis have an EROI between 4 and 16. Fuel enhancement with hydrogen (Power & Biomass to Liquids) impacts negatively the EROI due to the low EROI of hydrogen produced from renewable electricity. However, these fuels offer other advantages such as improved carbon efficiency. A correct estimate of EROI for forestry biomass, as proposed in this work, is a necessary dimension in assessing the suitability of a project.

A recent renaissance of industrial hemp has been driven by a plethora of ecologically amicable products and their profitability. To identify its environment and economic fate across the value chain (VC), this study conducts a systematic review of 98 studies published in ScienceDirect, Web of Science, and Scopus-indexed journals. The thematic content of the articles is categorized using three deductively derived classification categories: lifecycle analysis (n = 40), VC analysis (n = 30), and feasibility analysis (n = 28). Bibliometric analysis indicates that the majority (>90%) of the studies were conducted in selected regions of Europe or North America, with further findings around regionally prioritized industrial hemp products, such as hempcrete in Southwest Europe, solid biofuel in North European states, and textile fiber and bio-composites in East Europe and North America. Lifecycle analysis studies highlight nitrogenous fertilizer use during industrial hemp cultivation as a major ecological hotspot, which is taking a toll on the climate change index. However, hemp-based products are generally climate-friendly solutions when contrasted against their fossil fuel counterparts, with hempcrete in particular a highly touted carbon-negative (−4.28 to −36.08 kg CO₂ eq/m²) product. The review also identifies key issues within the hemp VC and presents innovative solutions alongside the recognition of value-adding opportunities. Furthermore, feasibility analysis indicates unprofitability in using hemp for bioenergy production and there is a relative cost worthiness of hemp bio-composites and hempcrete at the upstream level. Positive returns are observed under co-production schemes. In contemplating the literature findings, we discussed and identified gap in existing literature for future exploration, including more studies to provide insights from the Global South, and the production of industrial hemp under a biophysically constrained landscape.

Perennial tall grasses show promise as bioenergy crops due to high productivity and efficient nutrient use. Ongoing research on bioenergy grasses seeks to reduce their reliance on synthetic nitrogen (N) fertilizer, the manufacture of which relies on fossil fuel combustion. Excessive use of fertilizers also causes adverse environmental consequences and leads to the evolutionary loss of plant traits beneficial to sustainable N cycle. Notably, perennial tall grasses have exhibited the potential to maintain high biomass yield without the need for N fertilizer or causing soil N depletion. Perennial grasses can be adept at interacting with their microbial partners to facilitate N acquisition and retention via mechanisms such as biological N fixation and nitrification inhibition. These inherent N management traits should be preserved and optimized at the this early stage of bioenergy grass breeding programs. This review examines the impact of external N on bioenergy grass production and explores the potential of leveraging advantageous N-cycling attributes of perennial tall grasses, laying groundwork for future management and research efforts. With minimized dependency on external N input, the cultivation of perennial energy grasses will pave the way toward more resilient agricultural systems and play a significant role in addressing key global energy and environmental challenges.

China, as a significant global consumer of chemical fertilizers and a leading producer of rice, faces challenges associated with low fertilizer efficiency and fewer utilization options of rice husks. The development of rice husk biochar-based fertilizers (RHBF) offers a strategic solution to address these issues. In this study, diverse biochar fertilizer production techniques were used to develop four types of fertilizers: blended RHBF, soaked RHBF, high-pressure soaked RHBF, and pure rice husk biochar coated fertilizer. The nutrients slow-releasing performance of these four RHBF were compared by hydrostatic and soil column intermittent leaching methods. Effects of their application on rice growth, yield, and cadmium reduction potential were analyzed and compared by the pot trial. Results demonstrated that nutrients of the four RHBF were generally released slower in the soil compared with the conventional compound fertilizer (CK). The slow nutrient release effect was more pronounced under high-pressure soaked RHBF. Notably, in the soil column leaching experiment, the cumulative leaching rates of nitrogen and K₂O for RHBF3 (12.0% and 13.9%) were greatly lower than those of CK (42.3% and 51.3%). Moreover, the application of RHBF induced a marked enhancement in the nutrient use efficiency, grain yield, harvest index, and photosynthetic characteristics compared to CK. The average agronomic efficiency of P₂O₅ for the four RHBF increased by 102.8% compared with CK, while the average grain yield of the four RHBF increased by 20.6%. In addition, RHBF showed a significant reduction in Cd mobilization by an average of 80.1% compared to CK. This study offers a promising model for enhancing the comprehensive performance of RHBF and optimizing traditional fertilizer application practices.

As the world grapples with sustainable energy and environmental preservation challenges, budgeting for bio-resilience emerges as a pivotal step toward environmental sustainability. Our investigation delves into the influence of bioenergy technology budgets on the ecological footprint (ECF) in the top 10 nations that invest in bioenergy research and development (USA, China, Brazil, Germany, Japan, Canada, Sweden, Finland, Denmark, and the Netherlands). Prior research depended on panel data methods to explore the bioenergy technology-environment nexus, disregarding the specific traits of individual countries. Contrarily, the existing research applies the quantile-on-quantile tool to improve the precision of our analysis by delivering a holistic worldwide viewpoint and customized perceptions for every economy. The findings indicate that dedicating budgets to bioenergy technology improves environmental quality by reducing ECF across several quantiles within our sample nations. Moreover, the outcomes uncover unique patterns in these relationships across multiple countries. These results stress the significance of policymakers conducting exhaustive assessments and implementing productive tactics to address bioenergy technology funding and ECF changes.

Biochar application is widely recognized as an effective approach for increasing soil organic carbon (SOC) and mitigating climate change in agroecosystems. However, the effects of biochar application on net accumulations and relative contributions of different SOC sources remain unclear. Here, we explored the effects of biochar application on plant-derived (PDC) and microbial necromass C (MNC) in a 10-year experimental rice–wheat rotation field receiving four different intensities of biochar application (0, 2.25, 11.5, and 22.5 t ha⁻¹ for each crop season), using phospholipid fatty acids (PLFAs), lignin phenols and amino sugars as biomarkers of microbial biomass, PDC and MNC, respectively. Our results showed that biochar application increased SOC content and stock by 32.6%–203% and 26.4%–145%, respectively. Higher biochar application (11.5 and 22.5 t ha⁻¹) increased soil pH, total nitrogen (TN), total phosphorus (TP), SOC/TN, and root biomass. In addition, higher biochar application enhanced bacterial, fungal, and total microbial biomass. Plant lignin phenols and MNC contents significantly increased, whereas their contributions to SOC significantly decreased with the increase in biochar application rates due to the disproportionate increase in PDC and MNC, and SOC. Fungal necromass had a greater contribution to SOC than bacterial necromass. The fungal/bacterial necromass decreased from 2.56 to 2.26 with increasing biochar application rates, because of the higher abundances of bacteria than that of fungi as indicated by PLFAs under higher biochar application rates. Random forest analyses revealed that pH, TP, and SOC/TN were the main factors controlling plant lignin and MNC accumulation. Structural equation modeling revealed that biochar application increased lignin phenols by stimulating root biomass, whereas enhanced MNC accumulation was primarily from increased microbial biomass and lignin phenols. Overall, our findings suggest that biochar application increases the accumulation of the two SOC sources but decreases their contributions to SOC in paddy soils.

This study explores the sustainable production of biodiesel from nonedible Phyllanthus maderaspatensis seed oil (highest oil content of 35%, FFA 0.87 mg/KOH), utilizing an innovative green synthesis approach for chromium oxide nanoparticles derived from the waste fruit parts of Aubergine for the very first time in the current work. In pursuit of alternatives to fossil fuels, our research underscores the environmental and socio-economic benefits of biofuels, particularly in reducing greenhouse gas emissions. The optimized process yielded a 92% biodiesel conversion under conditions of a 9:1 methanol-to-oil ratio, 0.135 wt.% catalyst concentration, and a reaction duration of 150 min at 80°C. Comprehensive analysis techniques, including XRD, FTIR, SEM, EDX, Zeta analysis, differential reflectance spectroscopy (DRS), GC–MS, and NMR (¹H, ¹³C), were employed to characterize the synthesized nanocatalyst and biodiesel product. The biodiesel's fuel properties, such as acid value, fire point, pour point, viscosity, kinematic density, sulfur content, and cloud point, were rigorously tested, demonstrating compliance with international standards (ASTM D-6571, EN 14214, and GB/T 20828-2007). The use of P. maderaspatensis seed oil, an economical and environmentally friendly feedstock, in conjunction with a cost-effective nanocatalyst, presents a viable pathway for the sustainable and scalable production of biodiesel. This study contributes to the advancement of bioproducts for a sustainable bioeconomy by demonstrating an integrated approach to bioenergy production that leverages biotechnological innovations and addresses both environmental and socio-economic dimensions.

Microalgal biofuel is a promising solution to replace fossil fuel as a renewable and environmental-friendly energy source, thereby contributing to the United Nations (UN) Sustainable Development Goals (SDGs), in particular SDG-7, or Affordable and Clean Energy. Unlike energy crops (like oil palm and sugar cane), microalgae benefit from faster growth rate, higher lipid content, smaller land area required, ability to flourish using waste or brackish water, and posing zero competition with food crops. Microalgae-derived biofuels (like biodiesel, bioethanol, biomethane, and biohydrogen) are sustainable energy sources that can be produced using well-developed techniques (e.g., transesterification, fermentation, anaerobic digestion, and Fisher–Tropsch process). To prevent dire climate conditions resulting from the global temperature rise of 1.5°C and resolve worldwide energy security issue, our generation will need to establish and implement renewables on a global scale. To improve the industrial production of microalgal biofuel, the efficiencies of biomass and metabolite production to post-cultivation biofuel synthesis processes must be enhanced. For the cultivation step, there exist three key techniques that can directly change the traits, structure, and behavior of microalgal cells, and induce them to accumulate targeted metabolites rapidly and in large amounts. These techniques are genetic engineering, chemical modulation, and nanomaterial approach. Genetic engineering commonly alters the chloroplast DNA of microalgae to overexpress or down-regulate key genes in various metabolic pathways so that the cells accumulate more lipids. Chemicals can also be used to modulate microalgal growth and lipid accumulation by inducing oxidative stress or prevent conversion of lipid molecules. Nanomaterials and nanoparticles can also enhance microalgal lipid production by microenvironmental stress induction, vitamin supplementation, and light backscattering. Therefore, in this review, the recent progress as well as the pros and cons of genetic engineering, chemical modulation, and nanomaterial approach in achieving greater biofuel production from microalgae are comprehensively examined.

Lignocellulosic biomass is an abundant renewable feedstock, but its complex structure of lignocellulose poses barriers to its enzymatic hydrolysis and fermentation. Fungi possess diverse lignocellulolytic enzyme systems that synergistically deconstruct lignocellulose into soluble sugars for fermentation. This review elucidates recent advances in understanding the molecular mechanisms underpinning fungal degradation of lignocellulose. We analyze major enzyme classes tailored by fungi to depolymerize cellulose, hemicellulose, and lignin. Highlighted are the concerted actions and intimate partnerships between these biomass-degrading enzymes. Current challenges impeding large-scale implementation of enzymatic hydrolysis are discussed, along with emerging biotechnological opportunities. Advanced pretreatments, high-throughput enzyme engineering platforms, and machine learning or artificial intelligence-guided lignocellulolytic enzyme cocktail optimization represent promising ways to improve hydrolytic efficiencies. Elucidating the coordinated interplay and regulation of fungal lignocellulolytic machinery can facilitate optimization of fungal biotechnology platforms. Harnessing the efficiency of fungal biomass deconstruction promises to enhance the development of biorefinery processes for sustainable bioenergy.