Biotechnology Journal International

Antiplasmodial Activities and Biochemical Analysis of Cissampelos owariensis Leaf Extract

2026-08-20T13:04:42+00:00

This study evaluated the antiplasmodial activity and selected biochemical effects of aqueous leaf extract of Cissampelos owariensis in mice infected with Plasmodium berghei. The leaves were collected, authenticated, dried, powdered and extracted with distilled water. Acute oral toxicity was assessed before antiplasmodial testing. The extract was evaluated using three experimental models: the 4-day suppressive test, prophylactic test and curative test. Extract doses of 50, 100 and 200 mg/kg were administered orally, while normal saline served as the negative control. Chloroquine at 10 mg/kg was used as the positive control in the suppressive and curative models, and pyrimethamine at 1.2 mg/kg was used in the prophylactic model. Biochemical assays were conducted to assess catalase, superoxide dismutase, glutathione peroxidase and nitric oxide activities. Phytochemical screening indicated the presence of saponins, steroids, tannins, flavonoids and alkaloids. No mortality was observed during acute toxicity testing at doses up to 5000 mg/kg. In the suppressive test, the extract produced dose-related chemosuppression of 43.16%, 56.35% and 61.23% at 50, 100 and 200 mg/kg, respectively. In the prophylactic test, chemosuppression values were 22.59%, 55.48% and 79.23% at the same doses. In the curative model, parasitaemia decreased during treatment, with the 100 mg/kg dose showing marked reduction by day 7. The extract also influenced antioxidant and nitric oxide-related biochemical markers. These findings suggest that aqueous leaf extract of Cissampelos owariensis has antiplasmodial activity in the experimental mouse model and may contain bioactive constituents worthy of further pharmacological investigation.

Study of Complementary Feeding Practices: Analysis of Local Cereal Flour Consumption by Infants in the Haut-sassandra Region, Côte d’Ivoire

2026-08-21T11:20:51+00:00

Objective The study aims to analyse the consumption practices of locally produced cereal flours among infants in the Haut-Sassandra region of Côte d'Ivoire in order to assess their potential nutritional and health risks.

Study Design: A descriptive study combining a questionnaire-based survey with direct observations at flour points of sale.

Study Area and Duration: This study was conducted in the Haut-Sassandra Region, Côte d’Ivoire, specifically in the towns of Daloa, Vavoua, Issia, and Zoukougbeu. Fieldwork was conducted from 15 November to 18 July over the 2023–2024 study period.

Methodology: A survey was conducted among 500 breastfeeding mothers from four cities in the Haut-Sassandra region (Daloa, Vavoua, Issia, and Zoukougbeu) using a smartphone-administered questionnaire. The survey was complemented by direct observations at flour retail outlets.

Results: The results showed that the majority of the surveyed infants were between 6 and 12 months of age (50.4%), and that 95.2% of mothers reported having practised exclusive breastfeeding during the first six months of the child's life, before the introduction of complementary feeding. Maize flour (49.4%) and millet flour (41.2%) were the most commonly consumed complementary foods. Most mothers (66.4%) reported feeding these flours to their infants twice a day, with local markets being the main source of supply (99.6%). Nearly one in ten infants (8.8%) experienced digestive complications, including diarrhoea, vomiting, fever, and abdominal bloating, following the consumption of these flours. Infants aged 6–12 months were the most affected (9.12%). In addition, field observations revealed poor handling, packaging, and marketing conditions, which are conducive to microbiological contamination.

Conclusion: Locally produced artisanal cereal flours play a crucial role in ensuring food security among low-income households. However, their widespread use raises important public health concerns. These findings highlight the need for comprehensive microbiological and physicochemical characterisation of these products in order to better establish the relationship between consumption practices and the health disorders observed among infants.

Growth and Physiological Responses of the Ivorian Plantain Cultivar Affoto to Water Deficit and Rhizophagus irregularis Inoculation under Greenhouse Conditions

2026-08-24T11:00:50+00:00

Arbuscular mycorrhizal fungi (AMF) can improve plant performance under drought, but responses depend on host genotype, fungal isolate, symbiosis duration, and stress intensity. We evaluated whether Rhizophagus irregularis DAOM 197198 mitigated short-term water deficit in the Ivorian plantain cultivar Affoto under greenhouse conditions. Plants were assigned to a 2 × 3 factorial combination of inoculation (non-mycorrhizal or R. irregularis) and water supply (100% or 50% substrate water-holding capacity [WHC] replenished daily, or water withheld) for 14 days after a 14-day establishment period. Growth, organ water content, electrolyte leakage, chlorophyll index, leaf temperature, functional leaves, root colonization, and substrate spore density were quantified. Positive continuous responses were analyzed using log-linear models and heteroscedasticity-robust Type III tests; bounded responses were analyzed using beta or quasibinomial models. Water supply strongly affected total dry biomass (F_2,36= 34.44, P < 0.001), whereas inoculation (P = 0.789) and the inoculation × water-supply interaction (P = 0.946) did not. Mean total dry biomass declined from 104.73 g at 100% WHC to 70.58 g at 50% WHC and 36.02 g when water was withheld. Mycorrhizal growth responses were 2.7%, -4.1%, and -0.4%, respectively, and all 95% bootstrap confidence intervals included zero. AMF mitigation ratios were 0.935 (95% CI 0.627-1.422) at 50% WHC and 0.970 (0.626-1.572) under water withholding. Microscopy confirmed hyphae, vesicles, and arbuscules in inoculated roots, and none in controls; arbuscular abundance across the root system ranged from 24.92% to 31.81%. Thus, fungal establishment occurred, but inoculation did not detectably alter drought-associated biomass loss. Water deficit also reduced tissue hydration, growth dimensions, SPAD, and functional leaf proportion while increasing electrolyte leakage and leaf temperature. For the tested cultivar-isolate combination, following a short establishment period and under severe combined soil-water and atmospheric stress, R. irregularis conferred no detectable mitigation of biomass.

Antibiotic Resistance in Citrobacter, Isolated in Elderly Patients with Urinary Tract Infections in the Abidjan District, Ivory Coast

2026-08-29T11:50:51+00:00

Background: Urinary tract infections are common among older adults, and the emergence of antibiotic-resistant Citrobacter spp. complicates therapeutic management.

Aims: The objective of this study was to characterise antibiotic resistance genes in Citrobacter isolates from elderly patients presenting with urinary tract infections.

Study Design: This was a retrospective study.

Place and Duration of Study: The study was conducted at the Bacteriology and Virology Laboratory of the Pasteur Institute, Abidjan, Ivory Coast, from February 2023 to March 2024.

Methodology: A retrospective study was conducted using 47 clinical Citrobacter isolates collected at the Institut Pasteur de Côte d’Ivoire. Antimicrobial susceptibility was assessed by disc diffusion, extended-spectrum β-lactamase production was evaluated using a double-disc synergy test, and polymerase chain reaction was used to detect blaTEM, blaSHV, and blaCTX-M-1 genes.

Results: Citrobacter strains were isolated from 59.57% of the urine samples. Two species of Citrobacter were identified: Citrobacter freundii 85% (40/47) and Citrobacter koseri 15% (7/47). Generally, a low resistance rate (10.71%) was observed among the Citrobacter isolates in the presence of kanamycin. However, they exhibited a high resistance rate of 89.36% (42/47) to cefixime. Except for amikacin and kanamycin, the susceptibility profile of Citrobacter freundii showed resistance rates of 100% to both cefixime and aztreonam. Regarding Citrobacter koseri, a high resistance rate of 87.5% (35/40) was observed for cefixime, whereas a low resistance rate of 10.63% (5/47) was observed for kanamycin. In this study, the prevalence of Citrobacter strains producing extended-spectrum β-lactamases (ESBL) was 78.72% (37/47). Among the 47 strains, 14.9% (7/47) harbored the bla_CTX-M-1 gene, 12.77% (6/47) carried the bla_TEM gene, and 4.26% (2/47) possessed the bla_SHV gene.

Conclusion: The high resistance rates obtained compromise treatment efficacy. Consequently, there is an urgent need to implement surveillance strategies and develop new therapeutic alternatives to address this growing public health threat.

Bacteriological and Physicochemical Analyses of Ogi Fermented from Zea mays, Sorghum bicolor and Pennisetum glaucum Cereals

2026-08-31T09:39:24+00:00

The study assessed the bacteriological and physicochemical parameters during the fermentation of ogi from Zea mays, Sorghum bicolor and Pennisetum glaucum cereals. Ogi was produced from white Zea mays, yellow Zea mays, Sorghum bicolor and Pennisetum glaucum cereals and was allowed to ferment by steeping in distilled water for four (4) days at a temperature of 28 ºC. The effluents generated from the steeping water were collected daily for physicochemical (pH, total titratable acidity and temperature) and bacteriological (total heterotrophic bacterial count and total lactic acid bacterial count) analyses. After the fermentation process, the steeped grains were wet milled, sieved, allowed to sediment and decanted to produce the semi-solid ogi samples. The study revealed a decrease in pH from 6.83 to 4.40, an increase in total titratable acidity from 0.07 to 1.85g/L and an increase in temperature from 26.33 to 31.33ºC. There was an increase in the total heterotrophic bacterial count from 2.5×10⁵ to 63.5×10⁹ and in the total lactic acid bacterial count from 5.0×10³ to 98.5×10⁸ during fermentation. Bacteria belonging to the genera Enterobacter, Erysipelothrix, Pediococcus, Weisella, Veillonella, Proteus and Bacillus were present during the fermentation of ogi from white and yellow Zea mays, Sorghum bicolor and Pennisetum glaucum cereals. The study revealed high microbial populations, the presence of lactic acid bacteria and stable physicochemical conditions during the fermentation of white and yellow Zea mays, Sorghum bicolor and Pennisetum glaucum cereals to ogi.

Molecular and Evolutionary Characterization of Wild Yeast Isolates from Banana Fruit and Honey Relative to a Commercial Wine Yeast using Statistical Phylogenetic Tools

2026-09-11T10:19:01+00:00

Wild yeast isolates from banana fruit and honey were compared with a commercial wine yeast using partial ITS1–5.8S–ITS2 sequences and statistical phylogenetic analyses in MEGA 12. Five sequences representing banana isolates B7 and B10, honey isolates H4 and H7, and commercial yeast CY were evaluated for BLASTN affinity, evolutionary divergence, nucleotide composition, substitution-pattern homogeneity, neutrality statistics and relative-time relationships. BLASTN provisionally associated B7, B10, H4 and CY with Candida tropicalis and H7 with Clavispora lusitaniae; however, sequence identities of 77.6–95.0% were below the stated ITS thresholds for reliable species- and genus-level assignment. H4 and B10 showed the closest relationship, with divergence of 0.011 ± 0.005 substitutions per site, 100% bootstrap support and identical EcoRI profiles. The remaining pairwise distances ranged from 0.401 to 0.690 substitutions per site. The alignment was AT-rich (58.47%) and strongly transition-biased (R = 17.255), while disparity-index testing did not detect significant substitution-pattern heterogeneity among sequence pairs. Tajima’s D was 0.302 and is interpreted descriptively because the alignment spans more than one taxonomic group and includes only five sequences. Overall, the analyses support provisional molecular characterisation of the isolates but do not provide secure species-level identification. Re-verification of sequence quality and multilocus analysis are therefore required before definitive taxonomic interpretation.

Isolation, Characterization and Identification of Bacteria from Crude Oil Contaminated Soil at Obi-Ayagha, Delta State, Nigeria

2026-09-14T08:16:04+00:00

Background: Crude oil contamination can alter soil physicochemical properties and microbial communities, creating environmental and agricultural concerns. Indigenous bacteria occurring in contaminated soils may possess adaptive characteristics that enable survival under hydrocarbon stress and may therefore represent useful candidates for bioremediation. Characterising such bacteria is important for understanding their potential role in restoring petroleum-polluted environments.

Aim: This study was carried out to isolate and identify bacteria present in soil from an abandoned artisanal refinery in Obi-Ayagha, Ughelli South Local Government Area of Delta State, Nigeria.

Method: The samples were collected in sterile Ziploc bags, kept in a cooler containing ice packs, and transported to the laboratory at the Department of Pharmaceutical Microbiology and Biotechnology, Delta State University. The physicochemical properties of the soils were assessed following standard methods. One (1 g) gram of the soil sample was weighed and placed in nine (9) mL of normal saline, and a 1:10 serial dilution was carried out up to a dilution of 10^-7. A 0.1 millilitre aliquot of each of the different dilutions (10^-3 - 10^-6) was plated onto sterile agar plates containing different media (Nutrient agar (NA), Mannitol salt agar (MSA), MacConkey agar (McC), Cetrimide agar (CET), and Xylose Lysine Deoxycholate agar (XLD)). Colony counts were performed after 24 hours of incubation to determine the colony-forming units per mL (CFU/mL). Bacterial isolates were characterised and tentatively identified using Gram staining and biochemical tests.

Results: The results showed that cation exchange capacity (10.12 meq/100g), sulphate (46.18 mg/kg), available phosphate, and total organic carbon (1.9%) were higher in the artisanal soil than in the control soil, whereas total nitrate (97.55 mg/kg), pH (6.0), and moisture (6.0%) were higher in the control soil. Lead (7.11 mg/kg), nickel (13.30 mg/kg), and chromium (10.04 mg/kg) were also higher in the artisanal soil. Bacterial counts in the artisanal soil were 1.85 × 10⁶ CFU/g, 7.5 × 10⁵ CFU/g, 3.6 × 10⁵ CFU/g, 9.1 × 10⁴ CFU/g, and 7.5 × 10⁵ CFU/g on NA, XLD, McC, MSA, and CET, respectively. In the control soil, counts were higher on CET (7.6 × 10⁵ CFU/g), NA (2.61 × 10⁶ CFU/g), and XLD (7.6 × 10⁵ CFU/g). Seventeen bacteria were isolated. Staphylococcus species was the only Gram-positive bacterium identified, whereas Shigella, Salmonella, Proteus, Klebsiella, Acinetobacter, and Pseudomonas species were Gram-negative bacteria.

Conclusion: The results showed that some of the bacteria isolated and identified may be beneficial for the bioremediation of contaminated soil.

Assessment of the Infestation Level of the Fall Armyworm, Spodoptera frugiperda, on Cabbage and Tomato in Korhogo, Northern Côte d’Ivoire

2026-09-15T09:20:59+00:00

Vegetable crops are highly susceptible to pest attacks, including the fall armyworm (FAW). This study was conducted in the city of Korhogo to assess the incidence and severity of FAW and its impact on cabbage and tomato production, with the aim of improving control strategies in vegetable farming. A randomised complete block design (Fisher blocks) with three replications was used for the study. The parameters evaluated included larval density, attack incidence and severity, fruit weight, and yield. The results revealed a high FAW incidence of 51.85 ± 6.41% on tomatoes, compared to 44.44 ± 11.11% on cabbage. Regarding severity, the values were 12.96 ± 1.60% for tomato and 26.85 ± 13.13% for cabbage. Furthermore, FAW infestation significantly affected production: the yield from healthy tomato plants was 2333.75 ± 139.81 kg/ha, compared to 721.87 ± 200.01 kg/ha for infested plants. For cabbage, the yield from healthy plants was 7218.75 ± 1125.47 kg/ha, compared to 425 ± 199.36 kg/ha for infested plants. Infestation led to a substantial reduction in yield, with losses estimated at 69.06% for tomatoes and 94.11% for cabbage. This study confirmed that FAW infests certain vegetable crops, specifically cabbage and tomato, and that infestation levels can be comparable to those observed in maize.

Isolation, Phenotyping and Antimicrobial Activity of Bacillus spp. from Fermented Zamné, a Fermented Condiment from Senegalia macrostachya Seeds

2026-09-16T12:19:22+00:00

Background: Fermented Zamné is a traditional condiment produced from Senegalia macrostachya seeds.

Aims: This study aims to isolate and characterise predominant Bacillus-related bacteria from fermented Zamné and to evaluate their antimicrobial activity against selected indicator microorganisms.

Methods: A total of 65 aerobic mesophilic bacterial isolates obtained from four independent fermentations were characterised using morphological and biochemical methods.

Forty-four isolates were spore-forming, and 29 isolates displaying morphological characteristics consistent with Bacillus-related bacteria were further characterised and identified using the API 50 CHB system.

The antimicrobial activity of the isolates was evaluated by an agar well diffusion assay against 13 indicator microorganisms, including Gram-positive and Gram-negative bacteria, yeasts, and moulds.

Results: The isolates were assigned to five taxonomic groups: Bacillus subtilis/Bacillus amyloliquefaciens group (n = 17), Bacillus cereus (n = 3), Brevibacillus laterosporus (n = 5), Bacillus licheniformis (n = 3), and Bacillus megaterium (n = 1). Antimicrobial activity was detected only against five Gram-negative bacteria: Salmonella infantis, Salmonella Enteritidis, Pseudomonas aeruginosa, Proteus vulgaris, and Yersinia enterocolitica. Six isolates exhibited activity against at least one indicator microorganism. Among them, Brevibacillus laterosporus E4S1-5 inhibited all five susceptible Gram-negative bacteria, with inhibition zones ranging from 6.97 ± 0.06 to 13 ± 0.5 mm, while the isolate E4S2-2 (B. subtilis/ B. amyloliquefaciens group) displayed the broadest inhibitory spectrum of 14.5 ± 0.5 mm. Isolates E3S1-4 (Bacillus cereus), E3S3-4 and E1S2-5 (Brevibacillus laterosporus), and E4S2-1 (B. subtilis/B. amyloliquefaciens group) also exhibited variable antimicrobial activity.

Conclusion: These findings indicate that fermented Zamné harbours diverse Bacillus-related bacteria with antimicrobial potential. Selected Bacillus isolates with optimal antimicrobial properties may warrant further investigation as potential protective cultures for controlled Zamné fermentation. Molecular identification, safety assessment, and characterisation of the antimicrobial compounds produced by the active isolates are required before their technological application.

Enhancing Sugar Production from Obeche (Triplochiton scleroxylon K. Schum.) Sawdust by Synergistic Action of Gloeophyllum sepiarium and Aspergillus niger

2026-09-19T10:48:30+00:00

The study aimed to enhance sugar production in Obeche sawdust by the brown-rot Gloeophyllum sepiarium through elimination of the bottleneck caused by cellobiose product feedback inhibition.

The study was designed to use Aspergillus niger to produce supplementary β-glucosidase to relieve inhibition of cellobiose-producing cellulase.

The study took place in the Microbiology Laboratory, Delta State University, Abraka, between October 2024 and March 2026.

Gloeophyllum sepiarium (8) and Aspergillus niger (8) were isolated from deteriorating structural timber and identified by microscopy, cultural characteristics (potato dextrose/malt extract agar), and basidiocarp characteristics. The cellulolytic index (CI) of G. sepiarium isolates was determined using carboxymethyl cellulose (CMC), and the strain with the highest CI was selected for wood degradation and sugar production determinations using the dinitrosalicylic acid method. CMCase activity in the wood during degradation was determined. The hydrolytic index (HI) of A. niger isolates was determined on cellobiose agar, and the isolate with the highest HI was selected. The identities of both selected strains were confirmed by molecular methods. The influence of pH, nitrogen sources, and temperature on CI and HI was determined.

CI and HI ranged from 1.8-3.2 and 1.4-4.2 for G. sepiarium and A. niger, respectively. Comparative analyses indicated that the optimum conditions for CI and HI were pH 6, beef extract, and 35 ^oC (F=5.92-85.93, P=0.016-0.000). The selected Gloeophyllum sepiarium strain had the highest CI and caused greater sawdust weight loss (30.5-36.9 vs 27.7-32.4%) under optimum conditions. Sugar produced by the strain peaked at 42.4 mg/g after 3 weeks, declined to 20.2 mg/g, and then rose to 31.4 mg/g by the sixth week. CMCase activity in the wood followed the same trend. Combination with A. niger produced markedly higher sugar concentrations (64.7 vs 42.4 mg/g) over 6 weeks without a declining trend. Introduction of A. niger 2 weeks into degradation by G. sepiarium yielded 62.4 mg/g sugar in 20 days.

This synergism may be useful in biotechnological applications involving renewable resources.

Effect of Rhizophagus irregularis and Trichoderma harzianum on the Induction of Natural Defense in Cassava (Manihot esculenta Crantz) against Anthracnose

2026-09-19T12:43:40+00:00

Background: Cassava (Manihot esculenta Crantz) is a major staple food crop in Côte d’Ivoire. It contributes significantly to food security and serves as a source of income for farmers. However, cassava production is affected by phytopathogens.

Aims: This study was conducted to evaluate the effects of two biostimulants, Rhizophagus irregularis (RI) and Trichoderma harzianum (TH) on photosynthetic pigment synthesis, peroxidase and chitinase activities, and anthracnose control in cassava.

Place and Duration of Study: The two-month in vivo studies were conducted at the Ecology Research Center in Abidjan. A second study, focusing on defence compounds, was carried out at the Biocatalysis and Bioprocesses Laboratory at Nangui Abrogoua University, Côte d’Ivoire.

Methodology: Three cassava cultivars, YACE, 9620A, and TMS4(2)1425, were grown in vivo, with RI and TH treatments applied at planting. These fungi were applied individually and in combination (RI+TH). Plants treated with RI and TH were inoculated with the pathogen Colletotrichum gloeosporioides, 48 days after sowing.

Results: The results showed that, for each cassava cultivar, the RI+TH co-treatment showed the strongest inductive effect. For photosynthetic pigments, the highest Chl a and Car values were 38.89 and 9.60 µg/g FW, respectively, for the YACE cultivar; 32.54 and 9.69 µg/g FW for 9620A; and 36.08 and 9.02 µg/g FW for TMS4(2)1425. For enzyme activities, leaf peroxidase levels ranged from 0.90 to 0.98 ΔOD/min/mg prot., while root levels ranged from 1.54 to 1.69 ΔOD/min/mg prot. For chitinases, the highest activities were 103.01 mmol NAG/min/mg prot. in the leaves and 110.08 mmol NAG/min/mg prot. in the roots of the plants. Regarding anthracnose symptoms, the necrotic area caused by C. gloeosporioides in infected plants was reduced by 45 %, 47 %, and 49 % in YACE, TMS4(2)1425, and 9620A, respectively.

Conclusion: The application of R. irregularis and T. harzianum induced resistance to anthracnose in cassava.

Virus-induced Genome Editing in Plants: Viral Vector Biology, Germline Access and the Evidence Base for Heritable, Transgene-Free Crop Improvement

2026-08-31T11:49:12+00:00

Delivery, rather than nuclease chemistry, now sets the practical limit on plant genome editing. Conventional delivery depends on tissue culture and stable transformation, which remain slow, genotype-dependent and unavailable for most cultivated germplasm. Plant viruses offer an alternative because they replicate to high copy number, move systemically and can carry heterologous sequences into cells that no transformation protocol reaches. Virus-induced genome editing exploits this behaviour, and the field has moved within a decade from transient somatic mutagenesis in a model tobacco to heritable, transgene-free mutations in hexaploid bread wheat. This critical review evaluates the strength and the limits of that evidence. Vector chassis are compared on the properties that actually determine outcome, namely cargo capacity, insert stability, host range, movement behaviour and access to reproductive tissue, rather than on reported somatic editing percentages, which are shown to be poor predictors of germline transmission. The central unresolved problem is identified as the disjunction between efficient editing in infected somatic tissue and rare, stochastic entry of editing reagents into cells that give rise to gametes. Three engineering responses to that problem, namely fusion of guide RNAs to mobile RNA motifs, control of nuclease expression through meristem-competent promoters, and exploitation of axillary or adventitious growth points, are assessed against the evidence for each. Reagent miniaturisation, guide array design and virus-delivered precision editing are examined as partial solutions to the cargo constraint. Recurrent weaknesses in the literature are documented, including reliance on visible reporter loci, small progeny samples, inconsistent definitions of editing efficiency, near-absence of independent replication and the complete absence of field evaluation. The claim that virus-derived products are transgene-free is examined against the regulatory frameworks that will govern them, and the biosafety implications of releasing engineered, potentially insect-transmissible vectors are considered. Prioritised research directions are proposed, emphasising standardised reporting of progeny-level outcomes, biocontained vector design, and genotype-spanning validation in elite crop backgrounds.

Biofuel Production from Microalgae: A Critical Update on Cultivation, Conversion, System Integration and Commercial Readiness

2026-09-02T12:36:51+00:00

Microalgae remain scientifically compelling biofuel feedstocks because they can convert light and carbon into chemically diverse biomass without an intrinsic requirement for fertile agricultural land, while some production systems can also use saline water, wastewater nutrients and concentrated carbon dioxide streams. Yet the field has not translated laboratory demonstrations into routine production of competitively priced, low-carbon commodity fuels. This critical narrative review evaluates why that gap persists and how the research agenda has changed. Literature published from 1 January 2015 to 22 June 2026 was examined, with earlier seminal studies retained where necessary to establish mechanisms, process benchmarks and the evolution of sustainability arguments. Evidence was synthesised across strain physiology and engineering, cultivation, harvesting and dewatering, lipid-based biodiesel, hydrothermal liquefaction, pyrolysis, anaerobic digestion, carbohydrate-derived fuels, wastewater and carbon integration, techno-economics and life-cycle assessment. The central finding is that microalgal fuel performance is governed by cross-stage interactions rather than by a single favourable trait such as lipid content. Stress-induced lipid accumulation can reduce biomass productivity; controlled photobioreactors can improve culture performance while increasing capital and energy burdens; and downstream choices determine whether dilute wet biomass becomes an energetic liability or a useful feedstock. Hydrothermal liquefaction is particularly compatible with wet whole biomass, whereas conventional biodiesel benefits from mature chemistry but is constrained by selective lipid recovery and drying or extraction requirements. Wastewater, nutrient recycling, carbon utilisation and coproduct valorisation can improve system performance, but benefits are strongly context dependent and may be overstated when environmental-service credits or high-value coproduct revenues are assumed without scale-consistent markets. Pilot-informed life-cycle studies continue to show substantial sensitivity to electricity supply, infrastructure, productivity, nutrient source, dewatering and allocation choices. The most defensible near-term direction is therefore not a universal algal-fuel process, but location-specific, integrated biorefineries in which fuel production is co-designed with nutrient recovery, carbon management and realistic coproduct pathways. Progress towards commercial relevance requires continuous outdoor validation, harmonised assessment, wet-processing strategies and evidence that integrated gains persist at scale.

Nanofertilisers and Agricultural Productivity: A Critical Appraisal of Mechanisms, Field Evidence and Translational Constraints

2026-09-24T12:11:30+00:00

Mineral fertilisers underpin contemporary crop production, yet a large share of applied nitrogen, phosphorus and micronutrients is never recovered by the crop. Nanoscale nutrient carriers, commonly described as nanofertilisers, have been advanced as a means of raising nutrient use efficiency through smaller particle size, higher reactive surface area, controlled dissolution and more targeted delivery. Commercial products have already entered national fertiliser programmes in several countries, and the peer-reviewed literature has expanded far more rapidly than the evidence needed to justify that deployment. This review critically evaluates the state of knowledge on nanoscale nutrient delivery in crop production, with attention to the strength, consistency and methodological quality of the supporting evidence rather than to the accumulation of positive results. Literature was identified through structured searching of open scholarly databases and citation tracking, with appraisal focused on control selection, particle characterisation, experimental scale and duration, and the correspondence between mechanistic claims and agronomic outcomes. Four findings dominate the synthesis. Mechanistic evidence for size-dependent and coating-dependent foliar entry and translocation is substantial and reproducible, but it has rarely been connected to yield formation in the field. Agronomic gains reported for nanoscale products are typically modest and are frequently not benchmarked against equivalent ionic or bulk nutrient sources applied by the same route, so the increment attributable to the nanoscale state remains poorly resolved. Evidence for the most widely deployed macronutrient product, foliar nano urea, is openly contradictory, with multi-location trials and independent field studies reaching opposite conclusions about whether soil nitrogen can be safely reduced. Environmental, soil-biological and food-safety evidence remains dominated by short-term, high-dose exposures that correspond poorly to agronomic use. Confidence is highest for micronutrient delivery and stress amelioration under controlled conditions and lowest for macronutrient substitution at field scale. Priority requirements are multi-season, multi-site trials with ionic and bulk comparators, transparent particle characterisation, and nutrient-balance accounting rather than yield alone.

Genomics Studies of Rhizobacteria: Insights Gained from Genomics and Metagenomics on the Diversity and Functional Roles of Rhizobacteria

2026-09-26T10:16:56+00:00

Rhizobacteria occupy the chemically and physically dynamic interface between roots and soil, where bacterial traits can influence nutrient acquisition, root development, disease outcomes and stress responses. Genome sequencing and community metagenomics have transformed this field by moving inference beyond cultivation-dependent phenotypes and taxonomic inventories towards strain-resolved gene repertoires, biosynthetic capacity and community-level functional potential. This critical narrative review evaluates what genomics and metagenomics have established about rhizobacterial diversity and function, where the evidence remains conditional, and which methodological developments are most likely to improve causal understanding. Literature was selected through transparent searching of open scholarly databases and indexes, complemented by citation tracking, with emphasis on verified peer-reviewed studies spanning isolate genomics, comparative genomics, shotgun metagenomics, genome-resolved metagenomics, high-throughput cultivation and integrated multi-omics. The evidence consistently supports strong environmental filtering from bulk soil to the rhizosphere and root, while host genotype and developmental state impose additional but context-dependent effects. Comparative genomes reveal recurrent capacities for chemotaxis, transport, resource acquisition, secretion and secondary metabolism, yet large bacterial pan-genomes and extensive strain-level variation weaken attempts to predict phenotype from taxonomy alone. Shotgun metagenomics identifies functional enrichment in nutrient transformations, host-associated metabolism and antagonistic potential, but gene presence remains an imperfect surrogate for expression, metabolite production or benefit to plants. The strongest mechanistic studies therefore couple community profiling with isolates, synthetic communities, host or bacterial genetics, transcriptomics, metabolomics and phenotypic validation. Recent crop-scale genome catalogues and multi-omic field studies substantially improve reference coverage and connect host genetics with microbial functions, although geographic, soil and crop representation remain uneven. The field is consequently shifting from descriptive microbiome inventories towards testable, genome-informed ecological mechanisms. Progress in microbiome-assisted agriculture will depend on strain-level resolution, longitudinal field validation, explicit measurement of function, and predictive models that incorporate host genotype, microbial interactions and environmental context.