High Biomass Research Articles

Extracellular electron shuttles induced transformation and mobilization of Fe/As with the occurrence of biogenic vivianite.

Microorganisms that utilize organic matter to reduce Fe oxides/hydroxides constitute the primary geochemical processes controlling the formation of high-arsenic (As) groundwater. Biogenic secondary iron minerals play a significant role in As migration. However, the influence of quinone electron shuttles and competitive anionic phosphate on this process has not been thoroughly studied. In this study, 10 mM phosphate effectively increased the growth and reproduction of the indigenous metal-reducing bacterium Bacillus D2201, ensuring high biomass participation in goethite reduction. Three forms of goethite (pure goethite [Gt], goethite with coprecipitated As [Gt-As], and goethite with adsorbed As [Gt*As]) were synthesized and reduced by strain D2201 to investigate the fate of As/Fe. The results showed that the amount of Fe(II) released and precipitated in the Gt-As group with the addition of 9,10-anthraquinone-2,6-disulfonic acid (AQDS) and phosphate was the highest. Various solid-phase analytical techniques revealed that a significant amount of dissolved Fe(II) precipitated and formed the secondary mineral vivianite owing to phosphate input. Vivianite formation was pH-dependent, with high pH levels inhibiting vivianite development. As migration in the Gt-As system exhibited desorption and re-adsorption phenomena. The total As content decreased by 59.0 %, 53.7 %, and 49.4 %, at pH 6.0, 7.0, and 8.0, respectively, compared to the maximum As content values. The As re-adsorption percentage in the Gt*As group was lower than that in the Gt-As group, with decreases of 30.2 %, 16 %, and 10.3 % at pH, 6.0, 7.0, and 8.0, respectively. The results indicated that phosphate and AQDS enhanced goethite bioreduction and facilitated the migration of As and Fe. However, the subsequent formation of secondary vivianite resulted in the re-fixation of As and Fe. Our research suggested that metal-reducing bacteria may not universally facilitate As migration from sediments to groundwater, as previously assumed. This study highlights the effects of phosphate, As doping methods, and pH levels on As migration and transformation and refines theories on microbiologically induced high-As groundwater formation.

Incomplete human reference genomes can drive false sex biases and expose patient-identifying information in metagenomic data

As next-generation sequencing technologies produce deeper genome coverages at lower costs, there is a critical need for reliable computational host DNA removal in metagenomic data. We find that insufficient host filtration using prior human genome references can introduce false sex biases and inadvertently permit flow-through of host-specific DNA during bioinformatic analyses, which could be exploited for individual identification. To address these issues, we introduce and benchmark three host filtration methods of varying throughput, with concomitant applications across low biomass samples such as skin and high microbial biomass datasets including fecal samples. We find that these methods are important for obtaining accurate results in low biomass samples (e.g., tissue, skin). Overall, we demonstrate that rigorous host filtration is a key component of privacy-minded analyses of patient microbiomes and provide computationally efficient pipelines for accomplishing this task on large-scale datasets.

Phytoremediation of Oil-Contaminated Soil by Tagetes erecta L. Combined with Biochar and Microbial Agent.

Crude oil pollution of soil is an important issue that has serious effects on both the environment and human health. Phytoremediation is a promising approach to cleaning up oil-contaminated soil. In order to facilitate phytoremediation effects for oil-contaminated soil, this study set up a pot experiment to explore the co-application potentiality of Tagetes erecta L. with two other methods: microbial agent and biochar. Results showed that the greatest total petroleum hydrocarbon (TPH) biodegradation (76.60%) occurred in the soil treated with T. erecta, a microbial agent, and biochar; the highest biomass and root activity also occurred in this treatment.GC-MS analysis showed that petroleum hydrocarbon components in the range from C10 to C40 all reduced in different treatments, and intermediate-chain alkanes were preferred by our bioremediation methods. Compared with the treatments with biochar, the chlorophyll fluorescence parameter NPQ_Lss and plant antioxidant enzyme activities significantly decreased in the treatments applied with the microbial agent, while soil enzyme activities, especially oxidoreductase activities, significantly increased. Although the correlation between biochar and most plant growth and soil enzyme activity indicators was not significant in this study, the interaction effect analysis found a synergistic effect between microbial agents and biochar. Overall, this study suggests the co-addition of microbial agents and biochar as an excellent method to improve the phytoremediation effects of oil-contaminated soil and enhances our understanding of the inner mechanism.

Biopolymers Derived from Forest Biomass for the Sustainable Textile Industry

In line with environmental awareness movements and social concerns, the textile industry is prioritizing sustainability in its strategic planning, product decisions, and brand initiatives. The use of non-biodegradable materials, obtained from non-renewable sources, contributes heavily to environmental pollution throughout the textile production chain. As sustainable alternatives, considerable efforts are being made to incorporate biodegradable biopolymers derived from residual biomass, with reasonable production costs, to replace or reduce the use of synthetic petrochemical-based polymers. However, the commercial deployment of these biopolymers is dependent on high biomass availability and a cost-effective supply. Residual forest biomass, with lignocellulosic composition and seasonably available at low cost, constitutes an attractive renewable resource that might be used as raw material. Thus, this review aims at carrying out a comprehensive analysis of the existing literature on the use of residual forest biomass as a source of new biomaterials for the textile industry, identifying current gaps or problems. Three specific biopolymers are considered: lignin that is recovered from forest biomass, and the bacterial biopolymers poly(hydroxyalkanoates) (PHAs) and bacterial cellulose (BC), which can be produced from sugar-rich hydrolysates derived from the polysaccharide fractions of forest biomass. Lignin, PHA, and BC can find use in textile applications, for example, to develop fibers or technical textiles, thus replacing the currently used synthetic materials. This approach will considerably contribute to improving the sustainability of the textile industry by reducing the amount of non-biodegradable materials upon disposal of textiles, reducing their environmental impact. Moreover, the integration of residual forest biomass as renewable raw material to produce advanced biomaterials for the textile industry is consistent with the principles of the circular economy and the bioeconomy and offers potential for the development of innovative materials for this industry.

The hybrid approach to monitoring: a remote Rapid Assessment Protocol (RAP) complements existing monitoring tools for oyster restoration and management

Accurate and efficient monitoring of oyster reefs is critical for fisheries management and restoration. However, monitoring subtidal reefs requires labor‐intensive methods, such as sampling by SCUBA divers. A new Rapid Assessment Protocol (RAP) based on the collection of underwater imagery from random replicate points across a reef expands the toolkit for oyster reef monitoring. This study tests how the qualitative RAP compares to existing quantitative monitoring tools to inform approaches that combine methods and improve monitoring. We surveyed paired unrestored harvested reefs and restored sanctuary oyster reefs in the upper, middle, and lower Chesapeake Bay (United States) to compare the RAP to diver‐collected oyster metrics across management types and salinities. At each site, we compared the RAP's categorical habitat scores (based on percent cover and relative reef height in images) with physical metrics from synchronous diver collections, including live oyster density and biomass, on the same reef quadrats (n = 64). High RAP scores successfully captured high oyster density, biomass, reef height, rugosity, and multiple size classes. At lower RAP scores, the physical metrics often differed between RAP scores on unrestored harvested reefs, but not restored sanctuary reefs. This study highlights the value of underwater video in increasing monitoring efficiency with respect to time investment, while providing different habitat data than physical metrics. We describe how the RAP can be used in combination with more intensive, physical monitoring tools for restoration and fisheries management. The results of the RAP can inform oyster management in Chesapeake Bay and can be adapted for use worldwide.

Genome-Wide Association and Genomic Prediction of Alfalfa (Medicago sativa L.) Biomass Yield Under Drought Stress.

Developing drought-resistant alfalfa (Medicago sativa L.) that maintains high biomass yield is a key breeding goal to enhance productivity in water-limited areas. In this study, 424 alfalfa breeding families were analyzed to identify molecular markers associated with biomass yield under drought stress and to predict high-merit plants. Biomass yield was measured from 18 harvests from 2020 to 2023 in a field trial with deficit irrigation. A total of 131 significant markers were associated with biomass yield, with 80 markers specifically linked to yield under drought stress; among these, 19 markers were associated with multiple harvests. Finally, genomic best linear unbiased prediction (GBLUP) was employed to obtain predictive accuracies (PAs) and genomic estimated breeding values (GEBVs). Removing low-informative SNPs [SNPs with p-values > 0.05 from the additive Genome-Wide Association (GWAS) model] for GBLUP increased PA by 47.3%. The high number of markers associated with yield under drought stress and the highest PA (0.9) represent a significant achievement in improving yield under drought stress in alfalfa.

Effective semi-fed-batch saccharification with high lignocellulose loading using co-culture of Clostridium thermocellum and Thermobrachium celere strain A9.

Maximizing saccharification efficiency of lignocellulose and minimizing the production costs associated with enzyme requirements are crucial for sustainable biofuel production. This study presents a novel semi-fed-batch saccharification method that uses a co-culture of Clostridium thermocellum and Thermobrachium celere strain A9 to efficiently break down high solid-loading lignocellulosic biomass without the need for any external enzymes. This method optimizes saccharification efficiency and enhances glucose production from alkaline-treated rice straw, a representative lignocellulosic biomass. Initially, a co-culture of C. thermocellum and T. celere strain A9 was established with a treated rice straw loading of 150 g/l, supplemented with Tween 20, which enhanced enzymes stability and prevented unproductive binding to lignin, achieving a remarkable glucose concentration of up to 90.8 g/l. Subsequently, an additional 100 g/l of treated rice straw was introduced, resulting in a total glucose concentration of up to 140 g/l, representing 70.1% of the theoretical glucose yield from the 250 g/l treated rice straw load. In contrast, batch saccharification using an initial substrate concentration of 250 g/l of alkaline-treated rice straw without Tween 20 resulted in a glucose concentration of 55.5 g/l, with a theoretical glucose yield of only 27.7%. These results suggest that the semi-fed-batch saccharification method using co-cultivation of C. thermocellum and T. celere strain A9, supplemented with Tween 20 is an efficient microbial method for saccharifying high-concentration biomass. Moreover, this approach effectively manages high solids loading, optimizes efficiency, and reduces the need for external enzymes, thus lowering production costs and simplifying the process for industrial applications.

Biomass and Yield in Solanum lycopersicum Expressing a Synthetic Photorespiration Pathway

Considerable interest exists in improving the efficiency of photosynthesis and photorespiration to increase crop yields that will address growing world food needs. The current study investigated whether a novel synthetic photorespiratory pathway demonstrated to reduce photorespiratory metabolic energy demands and increase plant vegetative biomass in model species could boost tomato crop yield, notably yield of marketable fruit. The tomato cultivar Moneymaker was transformed with a synthetic photorespiration pathway construct containing a Cucurbita maxima malate synthase (MS) gene and a Chlamydomonas reinhardtii glycolate dehydrogenase (CrGDH) gene targeted to the chloroplast, with a plastid glycolate-glycerate translocator 1 (PLGG1) hairpin interference construct targeting the native photorespiratory pathway. Plants of seven T2 generation lines from independent transformation events expressed the MS and CrGDH transgenes, while having at least 3-fold reduction of native PLGG1 expression relative to non-transformed Moneymaker. Plants from transformed lines were larger and exhibited up to 63% increased biomass in comparison with the Moneymaker control. The number of fruit was similarly greater (1.4- to 4.2-fold) in modified plants; however, average individual fruit weights were significantly less for all but one line. Among transformed lines, larger fruited lines had the lowest biomass, while the smaller fruited lines had the highest biomass. Values for VCmax and Jmax derived from CO2 assimilation curves were statistically similar or lower in transformants relative to the control. Metabolic profiles obtained from high-performance liquid chromatography mass spectrometry (HPLC-MS) analysis revealed increases in forms of inactivated auxin. Principal component analysis of metabolite profiles separated transformants into two groups distinguished by total biomass and fruit size. Observed increases in plant biomass in transformed lines suggests that energy savings were realized from reduced photorespiration but were directed toward vegetative growth. Further studies to balance vegetative vs. reproductive biomass and exploit higher fruit counts observed in transformants may be beneficial for enhanced fruit yield.

Nitrogen, phosphorus, and potassium requirements to improve Sideritis cypria growth, nutrient and water use efficiency in hydroponic cultivation

Medicinal and aromatic plant (MAP) production is gaining popularity for industrial agriculture, with phytochemical compounds having a significant impact on human health. Plant fertilization must be carefully considered as it is strongly affecting the biochemical profile of MAPs. The present study examined the Sideritis cypria responses to different nitrogen (N: 75, 150, and 300 mg/L), potassium (K: 150, 350, and 550 mg/L), and phosphorus (P: 50, 75, and 100 mg/L) concentration in the nutrient solution (NS) in hydroponics. The NPK levels (150 mg N/L; 75 mg P/L and 350 mg K/L) in the NS, which was regarded an intermediate fertilization scheme, showed a rise in nutritional value with high phenols, flavonoids and antioxidant activity in plants. S. cypria grown in N75 levels revealed a decreased plant fresh weight and chlorophylls content while plants grown in N300 levels revealed increases in mineral accumulation, nutrient and water use efficiency. The NPK and the K550 levels caused oxidative stress as demonstrated by the raised lipid peroxidation and the stimulation of enzymes’ antioxidant activities. The P50 levels in the NS, increased the plant biomass and water use efficiency (WUE) and revealed the lower oxidative stress (malondialdehyde) and increased enzymes antioxidant (superoxide dismutase and peroxidase) activities. As a result, modifying the NS composition in hydroponic culture for S. cypria by using P levels of 50 mg P/L, higher biomass, nutritive value and WUE can be obtained.

Fungal endophytes modulate the negative effects induced by Persistent Organic Pollutants in the antarctic plant Colobanthus quitensis.

Antarctica has one of the most sensitive ecosystems to the negative effects of Persistent Organic Pollutants (POPs) on its biodiversity. This is because of the lower temperatures and the persistence of POPs that promote their accumulation or even biomagnification. However, the impact of POPs on vascular plants is unknown. Moreover, fungal symbionts could modulate the effects on host plants to cope with this stress factor. This study investigates the molecular and ecophysiological responses of the Sub-Antarctic and Antarctic plant Colobanthus quitensis to POPs in different populations along a latitudinal gradient (53°- 67° S), emphasizing the role of endophytic fungi. The results show that exposure of POPs in C. quitensis generates oxidative stress and alters its ecophysiological performance. Nevertheless, C. quitensis in association with fungal endophytes and POPs exposure, shows lower lipid peroxidation, higher proline content and higher photosynthetic capacity, as well as higher biomass and survival percentage, compared to plants in the absence of fungal endophytes. On the other hand, the antarctic plant population (67°S) with endophytic fungi presents better stress modulating upon POPs exposure. Endophytic fungi would be more necessary for plant performance towards higher latitudes with extreme conditions, contributing significantly to their general functional adaptation. We develop a transcriptomics analyses n the C. quitensis-fungal endophytes association from the Peninsula population. We observed that fungal endophytes promote tolerance to POPs stress through upregulated genes for the redox regulation based on ascorbate and scavenging mechanisms (peroxidases, MDAR, VTC4, CCS), transformation (monooxygenases) and conjugation of compounds or metabolites (glutathione transferases, glycosyltransferases, S-transferases), and the storage or elimination of conjugates (ABC transporters, C and G family) that contribute to detoxification cell. This work highlights the contribution of endophytic fungi to plant resistance in situations of environmental stress, especially in extreme conditions such as in antarctica exposed to anthropogenic impact. The implications of these findings are relevant for the biosecurity of one of the last pristine bastions worldwide.

Exploring the influence of carbon sources and salinity on the growth of microalgae

In the domain of microalgae cultivation, the selection of carbon source and salinity profoundly impacts the growth and metabolic activity of species like Chlorella sp. Carbon sources and salt serve as vital substrates, dictating not only biomass production but also shaping cellular processes essential for various applications, particularly as agricultural biofertilizers. This study investigated the impact of different carbon sources and varying concentrations of sodium chloride (NaCl) on the growth of Chlorella sp. It was found that CO2 bubbling significantly improved microalgae growth, resulting in a notable 5.60% increase compared to cultivation with sodium bicarbonate. Within a span of 14 days, Chlorella sp. reached its peak biomass of 1.32 g/L ± 1.2% under CO2 bubbling, outperforming NaHCO3 cultivation, indicating a more efficient carbon utilization. Furthermore, the study revealed that Chlorella sp. achieved its highest biomass and lipid yield under CO2 bubbling cultivation without the addition of NaCl (1.32 g/L ± 1.2% and 0.43 g/L ± 3.0 % respectively), while a NaCl concentration of 0.5 M yielded the highest lipid content (34% ± 1.8 %) but had relatively low lipid yield at 0.21 g/L ± 5.0%. This underscored the impact of NaCl stress on the growth and lipid content of Chlorella sp.

The hidden drivers: Unraveling the impact of density, moisture, and scale on Hermetia illucens rearing.

The black soldier fly (Hermetia illucens) is a saprophagous insect known for bioconverting organic waste, potentially offering environmental benefits, such as contributing to waste reduction and nutrient cycling. The performance of larvae varies significantly with factors substrate moisture, larval density, and scale of production. Three experiments were conducted using a mix of spent mushroom substrate (SMS) and chicken feed (CF). In the first experiment, 250 larvae were reared on 100 g dry matter (DM) feed at moisture levels of 65-75%. Results showed that the average individual larval weight, total biomass, and feed conversion ratio (FCR) improved with increased moisture. In the second experiment, 300 and 350 larvae/box were tested at 70% and 75% moisture. The highest average individual larval fresh weight (158.6 mg) was observed at 70% moisture with 250 larvae, while the highest biomass was achieved at 75% moisture with 300 larvae. Finally, different scales (10-2,500 g feed with 25-6,500 larvae) were tested with a similar feeding rate. The highest individual larval weight was recorded at the 100 g scale, with no clear correlation between weight and scale. However, the 50 g scale achieved the highest substrate reduction (33.2%). Overall, this study underscores the need to adjust moisture, density, and scale to nutrient conversion efficiency when using SMS, CF or other diets. The optimal results for the SMS feed mix were observed at 75% substrate moisture, 250 larvae per 100 g DM, and at approximately 2 larvae per cm2.

Chickpea displays a temporal growth response to Mesorhizobium strains under well-watered and drought conditions.

The relative performance of rhizobial strains could depend on their resource allocation, environmental conditions, and host genotype. Here, we used a high-throughput shoot phenotyping to investigate the effects of Mesorhizobium strain on the growth dynamics, nodulation and bacteroid traits with four chickpea (Cicer arietinum) varieties grown under different water regimes in an experiment including four nitrogen sources (two Mesorhizobium strains, and two uninoculated controls: nitrogen fertilised and unfertilised) under well-watered and drought conditions. We asked three questions. Does the impact of rhizobial strains on chickpea growth change with well-watered versus drought conditions? Do Mesorhizobium strains differ in their ability to influence biomass and nodule traits of chickpea varieties under well-watered and drought conditions? Are bacteroid size and amount of polyhydroxybutyrate modified by Mesorhizobium strain, chickpea variety, water availability and their interactions? Under well-watered conditions, chickpea inoculated with CC1192 showed higher shoot growth rates than M075 and accumulated high plant biomass at harvest. Under drought conditions, however, the shoot growth rate was comparable between CC1192 and M075, with no significant difference in plant biomass and symbiotic effectiveness at harvest. Across sources of variation, plant biomass varied 3.0-fold, nodules per plant 3.9-fold, nodule dry weight 3.0-fold, symbiotic effectiveness 1.5-fold, bacteroid size 1.4-fold and bacteroid polyhydroxybutyrate 1.4-fold. Plant biomass was negatively correlated with both bacteroid size and allocation to polyhydroxybutyrate under well-watered conditions, suggesting a trade-off between plant and rhizobial fitness. This study demonstrates the need to reassess rhizobial strain effectiveness across diverse environments, recognising the dynamic nature of their interaction with host plants.

How to develop nature-based solutions for revegetation on abandoned farmland in the Loess Plateau of China?

Adequate revegetation of abandoned farmland acts as a defence against desertification and soil loss, and can help remove carbon dioxide in the atmosphere, thereby playing an important role in regulating regional climate change. Legume, a nitrogen-fixation species, which could effectively improve vegetation coverage to control soil erosion, was widely used for revegetation. However, the dynamics of soil and plant development after legume introduction on abandoned farmland remain unclear. A 16-year in situ experiment including three treatments, natural abandonment (fallow), planting of alfalfa (Medicago sativa L.), and sweet clover (Melilotus officinalis L.) was conducted on bare farmland of the Loess Plateau in 2003-2018. The results showed that initially introduced species significantly affected the potential succession patterns in the community. Alfalfa introduction decreased plant community stability (CS) and hindered plant species establishment in early successional stages due to inter/intraspecific competition caused by high aboveground biomass (AB). Plant CS was affected by species evenness, AB, revegetation time and revegetation methods. Sweet clover facilitated succession process by rapidly improving soil conditions (organic carbon, nitrogen, and phosphorus) and quickly exiting from the community after its life span to avoid further competitive effects. During 2003-2018, the soil (water storage, organic carbon, nitrogen, and phosphorus), plant (AB, CS), and ecological related variables (plant diversity and soil carbon sequestration) contributed 60.1%, 15.7% and 20.2%, respectively, to the ecosystem health. Alfalfa planting increased ecosystem health index (EHI) in the long-term while sweet clover favours plant diversity, providing less overall EHI but recover faster than natural abandonment community. We concluded that alfalfa introduction, which provides the greatest AB, is a good option for comprehensively improving ecosystems (e.g., soil nutrient sequestration and control soil erosion) if the site in question suffers from few disturbances. Sweet clover introduction, however, is recommendable for restoring native biodiversity effectively if disturbances are frequent.

Differential effects of warming on carbon budget, photosynthetic yield and biochemical composition of cold-temperate and Arctic isolates of Laminaria digitata (Phaeophyceae).

Cold-temperate and Arctic hard bottom coastal ecosystems are dominated by kelp forests, which have a high biomass production and provide important ecosystem services, but are subject to change due to ocean warming. However, the photophysiological response to increasing temperature of ecologically relevant species, such as Laminaria digitata, might depend on the local thermal environment where the population has developed. Therefore, the effects of temperature on growth rate, biochemical composition, maximum quantum yield, photosynthetic quotient and carbon budget of young cultured sporophytes of Laminaria digitata from the Arctic at Spitsbergen (SPT; cultured at 4, 10 and 16°C) and from the cold-temperate North Sea island of Helgoland (HLG; cultured at 10, 16 and 22°C) were comparatively analyzed. Temperature significantly affected growth rates of L. digitata from SPT and HLG, with the highest rates occurring at 10°C, but growth did not differ between both isolates neither at 10°C nor at 16°C. Nevertheless, maximum quantum yield and carbon fixation rate were highest at 4°C for the Arctic and at 16°C for the cold-temperate L. digitata. Significantly higher rates of oxygen production and carbon fixation were observed in the cold-temperate relative to the Artic L. digitata at 10 and 16°C, respectively. Neither temperature nor biogeographic region of origin affected the photosynthetic quotient, and release rates of dissolved or particulate organic carbon. Total carbon and mannitol content were significantly higher in the Arctic compared to the cold-temperate L. digitata at 10°C, revealing an increased accumulation of storage compounds in the high latitude L. digitata. We conclude that L. digitata from SPT and HLG differ in their sensitivity to increasing temperatures and that the Arctic population from Spitsbergen is likely to benefit from ocean warming, while the temperate population from Helgoland will be negatively affected by further increases in ambient temperature.

Stable nutrient utilization of trees promotes community biomass accumulation in Korean pine and broad-leaved mixed forests after logging.

The recovery of community productivity in disturbed temperate forests is affected by fluctuating nutrient environments. How plant growth achieves high biomass accumulation in a limited nutrient environment remains unclear but may be attributed to the flexibility of plant nutrient utilization. Nutrient homeostasis (H) reflects the ability of plant tissues to maintain a relatively constant N and P content under nutrient fluctuations and represents flexible or stable plant nutrient utilization. We aim to reveal the influence of plant nutrient utilization mechanisms on community biomass accumulation after logging. We chose 28 post-logged Korean pine and broad-leaved mixed forests after seven recovery periods (6, 14, 25, 36, 45, and 55 years after logging) with six low-intensity selective logged treatments and one unlogged treatment (100 years after logging). We then estimated the H value of leaf N (HN), leaf P (HP), and leaf N:P ratio (HN:P) and the biomass of 234 plant species with different functional groups, soil nutrient, and species diversity. The leaf HN of 13.19 and the leaf HP of 9.87 reached the maximum at 36 and 45 years after logging, respectively. The HN:P at the community level reached the maximum at 36 years after logging. The robust linear trend between nutrient H and biomass suggests the accumulation of biomass benefits from stable nutrient utilization after logging. Considering the soil nutrient and species diversity, nutrient H showed the major explanation of biomass accumulation in trees, herbs, and whole community. The stable N utilization of tree species accounts for the maximum independent contribution (25.05%) to the community biomass accumulation. Herb species with flexible P utilization had major contribution (37.97%) to herb biomass accumulation. Our study highlights the vital role of high HN in promoting community biomass accumulation in logged forest to assess forest sustainability.

Enhanced biomass production and bioelectricity generation in microalgae culture medium using electrode pairings

Microalgae-based biofuel production offers promising avenues for sustainable energy generation. However, optimizing microalgae culture conditions for enhanced biomass production and bioelectricity generation remains challenging. This study addresses this problem by investigating the efficacy of different electrode pairings immersed in a microalgae culture medium. Two electrode pairs, Al-Fe and Cu-Zn were evaluated for their impact on microalgae growth and bioelectricity production. The optimum biomass concentration obtained was 1.204 g/L of Al-Fe electrodes with a lipid content of 15.1% and bioelectricity generation of 0.36V. The results demonstrated that Al-Fe electrodes induced high biomass concentration and lipid content in microalgae culture, facilitating biodiesel production. Conversely, Cu paired with Zn electrode promoted microalgae growth with elevated bioelectricity generation with 0.95V. This research sheds light on the potential of tailored electrode pairings to optimize microalgae culture conditions for dual-purpose biofuels and bioelectricity production, contributing to the advancement of sustainable energy technologies. It was recommended, among others, that further exploration of diverse electrode pairings within microalgae cultured medium could unveil additional effective strategies for optimizing biomass production and bioelectricity generation.

Advancements of astaxanthin production in Haematococcus pluvialis: Update insight and way forward.

The global market demand for natural astaxanthin (AXT) is growing rapidly owing to its potential human health benefits and diverse industry applications, driven by its safety, unique structure, and special function. Currently, the alga Haematococcus pluvialis (alternative name H. lacustris) has been considered as one of the best large-scale producers of natural AXT. However, the industry's further development faces two main challenges: the limited cultivation areas due to light-dependent AXT accumulation and the low AXT yield coupled with high production costs resulting from complex, time-consuming upstream biomass culture and downstream AXT extraction processes. Therefore, it is urgently to develop novel strategies to improve the AXT production in H. pluvialis to meet industrial demands, which makes its commercialization cost-effective. Although several strategies related to screening excellent target strains, optimizing culture condition for high biomass yield, elucidating the AXT biosynthetic pathway, and exploiting effective inducers for high AXT content have been applied to enhance the AXT production in H. pluvialis, there are still some unsolved and easily ignored perspectives. In this review, firstly, we summarize the structure and function of natural AXT focus on those from the algal H. pluvialis. Secondly, the latest findings regarding the AXT biosynthetic pathway including spatiotemporal specificity, transport, esterification, and storage are updated. Thirdly, we systematically assess enhancement strategies on AXT yield. Fourthly, the regulation mechanisms of AXT accumulation under various stresses are discussed. Finally, the integrated and systematic solutions for improving AXT production are proposed. This review not only fills the existing gap about the AXT accumulation, but also points the way forward for AXT production in H. pluvialis.

Unlocking the potential of Albizia procera: A multifunctional tree for sustainable development and climate resilience

Albizia procera (Roxb.) Benth., a versatile and fast-growing tree species under the family Fabaceae, holds substantial potential for advancing sustainable development and climate resilience. This review highlights the taxonomy, ecological benefits, and diverse applications and ecological benefits of A. procera, emphasizing its role in reforestation, agroforestry, and sustainable forestry practices. A. procera is also valued for its high-quality timber, contributing to traditional woodworking and modern engineered products like Glulam beams, demonstrating its economic value. Additionally, A. procera contributes to its carbon sequestration, aligning with climate action goals due to its high biomass productivity. While acknowledging the need for careful management to mitigate risks such as invasiveness, this review underscores the significance of A. procera in fostering ecological restoration, sustainable livelihoods, and climate adaptation strategies. Its multifaceted benefits position A. procera as a critical asset in pursuing a sustainable and resilient future. Bangladesh J. Plant Taxon. 31(2): 329-347, 2024 (December)

Understanding the triacylglycerol-based carbon anabolic differentiation in Cyperus esculentus and Cyperus rotundus developing tubers via transcriptomic and metabolomic approaches

BackgroundYellow nutsedge (Cyperus esculentus, known as ‘YouShaDou’ in China, YSD) and purple nutsedge (Cyperus rotundus, known as ‘XiangFuZi’ in China, XFZ), closely related Cyperaceae species, exhibit significant differences in triacylglycerol (TAG) accumulation within their tubers, a key factor in carbon flux repartitioning that highly impact the total lipid, carbohydrate and protein metabolisms. Previous studies have attempted to elucidate the carbon anabolic discrepancies between these two species, however, a lack of comprehensive genome-wide annotation has hindered a detailed understanding of the underlying molecular mechanisms.ResultsThis study utilizes transcriptomic analyses, supported by a comprehensive YSD reference genome, and metabolomic profiling to uncover the mechanisms underlying the major carbon perturbations between the developing tubers of YSD and XFZ germplasms harvested in Yunnan province, China, where the plant biodiveristy is renowned worldwide and may contain more genetic variations relative to their counterparts in other places. Our findings indicate distinct expression patterns of key regulatory genes involved in TAG biosynthesis and lipid droplet formation, including transcriptional factors and structural genes such as ABI3 transcriptional factor, rate-limiting enzymes GPAT3/6/9 and DGAT2/3, and oleosin and caleosin homologs. Furthermore, our omics data suggest that these differences in gene expression are not the sole contributors to the diverse tuber compositions. Instead, complex interactions among highly regulated catalytic reactions, governing carbohydrate, protein, and species-specific metabolite metabolisms, such as starch and sucrose metabolic pathways, flavonoid and amino acids biosynthetic pathways, collectively contribute to the pronounced carbon anabolic differentiation primarily evident in TAG accumulation, as well as the starch properties in mature tubers.ConclusionThis study offers new metabolic insights into the high-value underground non-photosynthetic tissues of Cyperaceae species, which harbors not only high biomass productivity but also abundant nutrients as favorable food or industrial sources in the modern agriculture. The detailed omics analyses aim to deepen our understanding of the Cyperaceae species, which may potentially broaden their application values and facilitate the molecular breeding of better varieties to ameliorate the food safety problem.