Biotechnology Journal International

Biocontrol of Molds Growth during Cocoa Bean (Theobroma cacao L.) Fermentation Using Native Yeast Species: Saccharomyces cerevisiae and Candida incommunis

2026-10-22T13:30:03+00:00

Background: The overall quality of dry fermented cocoa beans is three-dimensional, including the market, aromatic, and health aspects. The molds that are present during post-harvest technological treatments up to the storage of fermented and dried cocoa beans play a harmful role by degrading the health quality of the cocoa beans. Cocoa from Ivory Coast is no exception to this problem; it is exposed to potential major risks of contamination with ochratoxin A, produced by mold.

Aims: The present study investigated the reduction of contamination of cocoa beans by mold using potentially antagonistic biological agents including antifungal yeasts such as Saccharomyces cerevisiae and Candida incommunis.

Study Design: Biocontrol of mycotoxigenic mold growth in cocoa using yeasts.

Place and Duration of Study: Food Biotechnology and Microbiology Laboratory, Food Science and Technology Research Department, Nangui ABROGOUA University, Côte d’Ivoire, between March and June 2024.

Methodology: After highlighting the antifungal properties of Saccharomyces cerevisiae and Candida incommunis by direct and indirect confrontation techniques on Aspergillus carbonarius, A. ochraceus, and A. niger isolated from cocoa fermentation, they were inoculated into the cocoa beans before fermentation. The physicochemical parameters were measured.

Results: The main results obtained showed antagonistic effects of S. cerevisiae and C. incommunis against all the pathogenic molds A. carbonarius, A. niger, and A. ochraceus. After inoculation for fermentation, among the tested biological agents, only C. incommunis induced an increase in temperature reaching 49 °C. The titratable acidity of the inoculated cocoa beans was between 0.06 and 0.12 Eq. of NaOH.g^-1 of cocoa during fermentation. No potentially antifungal biological agent tested had any effect on the marketability of cocoa. However, only C. incommunis showed a total biocontrol effect against molds during cocoa fermentation.

Conclusion: The findings of this study could be applied to the bio-decontamination of fermented foods contaminated with pathogenic molds, and thus to reducing mycotoxin production using C. incommunis, which exhibits high fungal antagonistic potential.

Germination and Early Seedling Vigor of Pentadesma butyracea under Abiotic Constraints: Implications for the Domestication of a Threatened Wild Oilseed Species in Benin

2026-10-26T13:51:44+00:00

Pentadesma butyracea is a vulnerable multipurpose tree whose propagation by seed is limited by poor and heterogeneous germination. This study evaluated the effects of seed source, temperature, seed coat removal, gibberellic acid (GA₃) and substrate on germination and early seedling growth. Seeds from eight mother trees (four per zone) collected in the Sudano-Guinean and Sudanian zones of Benin were incubated at five constant temperatures (20-40 °C). In the greenhouse, a factorial experiment combined seed type (dehusked and intact), GA₃ (0, 10 and 20 mg/L) and substrate (poorly developed soil, vertisol and ferralitic soil). Germination varied strongly with mother tree, temperature and their interaction (P < 0.0001). Only one tree (ZSGP1) germinated well at 40 °C (70%). The higher mean germination of Sudano-Guinean seeds (24.5% vs. 11.5%) was largely driven by this single tree, so ecotypic differentiation between zones could not be demonstrated. Seed coat removal shortened the latency period (7 vs. 14 days), concentrated germination (peak at 28 days vs. spread over 70 days) and increased final germination (99.2% vs. 82.5%) and seedling growth (height: 32.4 vs. 24.8 cm; root-collar diameter: 0.66 vs. 0.52 cm). GA₃ brought no benefit to germination and reduced seedling height at the tested concentrations, and substrate type had no significant (P > 0.05) main effect, although it interacted with seed type for seedling growth. Seed weight was positively related to seedling size but explained at most 20% of its variation. Seed coat removal is recommended for nursery propagation, and seed collection should be spread across many mother trees; ZSGP1 deserves further evaluation for heat-tolerant germination. Results are preliminary given the small number of mother trees per zone and the controlled conditions, but these crucial findings provide strategic guidelines for accelerating high-quality plant stock production in forest nurseries.

Molecular Modeling and Virtual Screening: Application to the Design of Benzoisoxazole-Derived Inhibitors for the Treatment of Prostate Cancer, Bromodomain-Containing Protein 4 (BRD4)

2026-10-27T11:47:32+00:00

Bromodomain-containing protein 4 (BRD4) contributes to transcriptional regulation implicated in castration-resistant prostate cancer and is a candidate target for the design of small-molecule inhibitors. This study used molecular modelling and virtual screening to explore benzoisoxazole derivatives with predicted BRD4 inhibitory activity. A three-dimensional quantitative structure–activity relationship (3D-QSAR) pharmacophore was constructed using active conformations of 23 benzoisoxazole derivatives. The selected Hypo1 hypothesis comprised five pharmacophore features and showed a squared correlation coefficient of 0.951, a root mean square deviation of 1.861, and a total cost of 97.682. Cat-Scramble evaluation was performed at a 98% confidence level. Systematic substitution at two positions of the scaffold yielded a virtual combinatorial library of 99,856 analogues. After drug-likeness filtering and pharmacophore screening, 120 analogues matched at least four of the five features and were assessed using a previously developed complexation QSAR model. Predicted absorption, distribution, metabolism and excretion properties were examined with QikProp. Molecular dynamics simulations of selected BRD4–ligand complexes were performed over 200 ns to assess conformational behaviour and ligand interactions. Six prioritised analogues—57-42, 7-39, 47-11, 7-42, 45-316, and 44-14—showed comparatively favourable predicted oral absorption and molecular dynamics profiles. The results support their prioritisation for synthesis and experimental evaluation, while remaining computational predictions rather than evidence of biological efficacy.

Diagnostic Accuracy of Rapid Diagnostic Tests for Typhoid Fever among Patients in Ga West Municipality, Ghana

2026-10-27T11:59:00+00:00

Background: Typhoid fever remains a major public health challenge in many low- and middle-income countries, particularly in sub-Saharan Africa, where diagnostic limitations complicate the management of febrile illness. Rapid diagnostic tests (RDTs) are widely used as point-of-care tools in resource-limited settings, but concerns remain about their diagnostic accuracy in endemic settings.

Aim: This study assessed the diagnostic accuracy of RDTs for typhoid fever among febrile patients in Ga West Municipality, Ghana.

Methods: A quantitative cross-sectional design was used to recruit 284 febrile patients from health facilities in Ga West Municipality. Each participant underwent both RDT and blood culture testing, with blood culture serving as the reference standard. We calculated diagnostic accuracy parameters, including sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), and conducted hypothesis tests to assess diagnostic misclassification.

Results: The RDT showed an observed sensitivity (100%) and a negative predictive value of 100% in the study sample. However, specificity was poor (52.5%), and the positive predictive value was extremely low (5.8%), reflecting a substantial number of false-positive results. The diagnostic misclassification rate was 46.1%, and the reported hypothesis tests rejected all three null hypotheses (P<0.05).

Conclusion: Although the RDT showed high observed sensitivity in this sample, its poor specificity and low PPV make it unreliable for definitive typhoid diagnosis in this setting. The study recommends confirmatory testing for all positive RDT results and supports improvements in diagnostic algorithms to guide clinical decision-making and reduce inappropriate antibiotic use in febrile illness management.

Evaluation of the Postharvest Storage Performance of Six Onion (Allium cepa L.) Varieties under Ambient Storage Conditions in Bambey, Senegal

2026-10-29T12:32:35+00:00

Onion (Allium cepa L.) storability is important for reducing postharvest losses and maintaining market availability in Senegal. This study evaluated the postharvest performance of six onion varieties under ambient storage conditions in Bambey. The varieties were Violet de Galmi, Gandiol+, Safari, Texas Early Grano, Red Bombay and VDG American. Field production was undertaken during the 2021–2022 cool off-season using a randomised complete block design with three replicates. After harvest, bulb dry matter content was determined, and weight loss, sprouting and rot were assessed during storage. Dry matter content did not differ significantly among varieties (p = 0.069), although VDG American recorded the highest numerical value (13.24%) and Texas Early Grano the lowest (8.69%). In the storage analysis, VDG American exhibited the lowest numerical weight loss (10.91%), with no recorded sprouting or rot. Safari also had relatively low weight loss (11.61%), no sprouting and a rot rate of 2.22%. Red Bombay showed the highest sprouting (24.33%) and rot (31.11%), while Texas Early Grano had the highest numerical weight loss (32.49%). Varietal differences in sprouting were significant (p < 0.001), whereas those in weight loss and rot were not significant at the 5% level. Under the conditions assessed, VDG American and Safari showed favourable storage performance, although further evaluations are required before broader recommendations can be made.

Integrated Assessment of Genetic Diversity and Reproductive Potentials in African Catfish (Clarias gariepinus; Burchell, 1822) from River Benue, Nigeria

2026-11-02T07:55:35+00:00

Genetic diversity and reproductive performance are important determinants of the sustainability of wild fish populations and the selection of suitable broodstock for aquaculture. This study evaluated the genetic diversity, morphometric characteristics, and reproductive potential of Clarias gariepinus from the Upper, Middle, and Lower sections of River Benue in Taraba State, Nigeria. Sixty (60) sexually mature specimens (20 per sampling location) were collected between March and May 2026. Morphometric measurements, gonadosomatic index (GSI), absolute and relative fecundity, and egg diameter were determined using standard procedures. Genetic diversity and population relationships were assessed using mitochondrial 16S rRNA sequences, haplotype diversity, nucleotide diversity, phylogenetic analysis, and haplotype network reconstruction. Fish from the Lower Benue exhibited the highest mean total length (45.72 ± 3.98 cm) and body weight (1,276.84 ± 210.31 g). Female GSI was highest in the Lower Benue population (10.54 ± 1.06%), compared with the Middle (9.68 ± 0.92%) and Upper (8.47 ± 0.88%) populations. Absolute fecundity followed a similar pattern, with the highest value recorded in the Lower Benue (85,230 ± 6,980 eggs) and the lowest in the Upper Benue (70,350 ± 5,720 eggs). Female body weight was strongly positively correlated with absolute fecundity (r = 0.81, p < 0.01). Analysis of mitochondrial DNA sequences identified six unique haplotypes (H1 - H6), with frequencies of 28, 9, 7, 6, 5, and 5 individuals, respectively among the 60 Clarias gariepinus specimens sampled from the Upper, Middle, and Lower Benue populations, with haplotype diversity ranging from 0.76 to 0.84 and nucleotide diversity from 0.0036 to 0.0052. Phylogenetic clustering and the distribution of shared haplotypes suggested genetic relatedness among the sampled populations. These findings indicate spatial variation in morphometric characteristics and reproductive performance, alongside moderate to high mitochondrial genetic diversity in the sampled populations. The results provide preliminary evidence to support broodstock selection and the conservation of genetic resources of C. gariepinus in River Benue.

Assessment of the Methanogenic Potential of Biogas Produced by Anaerobic Co-digestion of Three Mixing Ratios of Seaweed Waste (Sargassum spp.) and Pig Manure

2026-11-02T13:32:17+00:00

Objective: The aim of this study was to evaluate the methanogenic potential of biogas produced by anaerobic co-digestion using three different mixing ratios of seaweed waste (Sargassum spp.) and pig manure.

Methodology: Biogas production was carried out using an experimental water-displacement system. Three experimental set-ups were prepared using three mixing ratios of the substrate and co-substrate. The first bioreactor was fed with a mixture comprising 30 % of seaweed waste and 70 % of pig manure (30:70). The second set-up was fed with 50 % of seaweed waste and 50 % of pig manure (50:50), and the third comprised 70 % of seaweed waste and 30 % of pig manure (70:30). The fermentation process lasted 32 days and was carried out in batch mode. The composition of the biogas produced from each mixture was analysed, and flammability tests were performed.

Results: The results showed that the cumulative volume of biogas for the 30:70, 50:50 and 70:30 ratios was 16.5 L, 17.8 L and 5.4 L, respectively. The biogas produced at the 30:70 ratio exhibited the highest methane content, at 60 %, while those produced at the 50:50 and 70:30 ratios had methane contents of 45 % and 36 %, respectively. In addition, the biogas flammability test showed a blue flame for the biogas produced at the 30:70 ratio, whereas no blue flame was observed for the biogas produced from the other two mixtures.

Conclusion: The biogas produced from the mixture containing 30 % seaweed waste and 70 % pig manure therefore showed the highest observed methane fraction. This study suggests a possible route for recovering energy from seaweed strandings while addressing coastal waste management.

Phenotypic and Molecular Characterisations of Coliforms in Tomato Fruits from Ondo Metropolis Markets

2026-11-05T08:14:35+00:00

Background: Tomato fruits are widely consumed in Nigeria but are susceptible to microbial contamination during cultivation, transportation and marketing.

Aim: Tomatoes (Solanum lycopersicum) are widely consumed in Nigeria and constitute a major component of daily diets. However, their susceptibility to microbial contamination during cultivation, transportation and marketing poses serious public health concerns. This study investigated the phenotypic traits, molecular characterisations and antibiotic susceptibility of coliforms isolated from both ripened and rotten tomato fruits sold in selected markets within Ondo Metropolis.

Methodology: Both rotten and ripened tomato samples were collected from five major markets in Ondo Metropolis and analysed using standard microbiological procedures. Coliforms were isolated and identified through cultural, morphological and biochemical tests, and were further characterised using molecular identification by extracting DNA from bacterial cells and amplifying the gene of interest (16S rRNA) with primers to identify the proposed coliforms. Antibiotic susceptibility testing was carried out using the disc diffusion method.

Results: The microbial load of the rotten tomatoes was higher than that of the ripened tomatoes. The results revealed that the microorganisms in tomato samples across all markets were: Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Pseudomonas aeruginosa and Bacillus spp. Molecular analysis confirmed the identity of the isolates, with high sequence similarity (>99%) to reference strains in the National Center for Biotechnology Information database. All microorganisms isolated demonstrated resistance to at least one antibiotic tested. Pseudomonas aeruginosa exhibited the highest susceptibility to ciprofloxacin, gentamicin and tetracycline.

Conclusion: The study provided additional information on the coliforms found in tomatoes and highlighted the need for improved hygiene practices, effective monitoring of fresh produce and stronger antimicrobial stewardship policies in Nigeria.

Valorizing Carbonized Rice Husk Material for Improving Maize Vegetative Growth in Northern Côte d’Ivoire

2026-11-05T12:34:39+00:00

The valorisation of agricultural residues offers opportunities for developing more sustainable fertilisation practices. This study was conducted in Mankono, Béré Region, northern Côte d’Ivoire, in 2022 from the end of the long rainy season (July to September) followed by the transition to the long dry season (October to November). This research aimed to evaluate the effects of a carbonised material, produced by heating rice husks in a furnace for three hours under limited air supply, on maize vegetative growth. The field experiment was conducted using a Fisher block design with four treatments and four replications: T0 (unfertilised control), T1 (50 g of carbonised rice husks per plant), T2 (100 g of carbonised rice husks per plant), and T3 (mineral fertilisation). Stem length, plant height, stem diameter, and number of leaves were measured at eight different intervals during the growing cycle. The results revealed significant differences among treatments in stem length and plant height, with mineral fertilisation generally producing the highest values. Treatment T2 showed intermediate performance and improved several vegetative growth parameters as compared to the unfertilised control at different measurement dates. For leaf number, T2 and T3 did not differ significantly at the final observation. In contrast, no significant variation was observed among the treatments for the stem diameter. Overall, the application rate of 100 g of carbonised material per plant showed the greatest potential among the two rates tested, although its performance did not consistently match that of mineral fertilisation. These findings highlight the potential value of rice husk valorisation for maize production while supporting further research into the physicochemical properties of the material, soil characteristics, and crop yield.

Biotechnological Strategies for Improving Crop Yield and Stress Tolerance: A Critical Synthesis from Genomic Selection to Precision Engineering

2026-10-23T09:51:57+00:00

Crop improvement increasingly depends on biotechnological methods that can accelerate genetic gain while preserving yield under drought, salinity, heat, nutrient limitation and biotic stress. Yet the field is often discussed as a collection of technologies rather than as a translation problem linking target discovery, genetic intervention, plant regeneration, field validation and breeding deployment. This critical narrative review evaluates the principal biotechnology platforms used to improve crop yield and stress tolerance, with emphasis on evidence maturity, field relevance, genetic architecture and the causes of inconsistent translation. Literature published primarily from 1 January 2015 to 8 August 2026 was examined, while earlier seminal studies were retained when they established concepts or field-tested traits that remain influential. The synthesis covers genomics-assisted selection, pan-genomics and phenomics, transgenic and RNA-based engineering, CRISPR-associated genome editing, base and prime editing, synthetic and metabolic engineering, and transformation and regeneration technologies. Evidence is strongest where biotechnology is integrated with breeding and tested against agronomically meaningful outcomes across realistic environments. Genomic selection is particularly suited to polygenic traits, but prediction decays when training populations poorly represent target environments. Transgenic and genome-edited interventions have generated convincing examples of improved drought performance, salinity tolerance and disease resistance, although effect sizes are frequently context dependent. Cis-regulatory editing and allelic series offer a promising route to tune quantitative traits while reducing pleiotropic penalties, whereas base and prime editing broaden sequence precision but remain constrained by delivery, editing efficiency and crop-specific regeneration. Photosynthetic and metabolic engineering has produced notable field proof-of-concept, yet transfer from model or experimental systems to major crops remains incomplete. Across platforms, the dominant bottlenecks are genotype-dependent transformation, genotype-by-environment interaction, combined stresses, fitness trade-offs, durability of resistance, and insufficient multi-environment validation. The most defensible strategy is therefore not technological substitution but an integrated pipeline in which genomic prediction and phenotyping identify robust targets, precision engineering generates controlled allelic variation, and multi-environment breeding determines whether molecular gains become stable yield advantage.

Cyanobacteria as a Valuable Source of Mycosporine-like Amino Acids for Biotechnological Applications

2026-11-05T13:52:35+00:00

Cyanobacteria are photosynthetic prokaryotes that appeared on Earth more than 2.6 billion years ago. They are found in many environments, including land and water, and play an important role in primary production and nitrogen fixation. However, because they need sunlight for photosynthesis, cyanobacteria are often exposed to increasing levels of ultraviolet (UV) radiation at the Earth’s surface. Over time, cyanobacteria have developed different ways to protect themselves from UV radiation. One important mechanism is the production of mycosporine-like amino acids (MAAs), which act as natural UV protectants. MAAs are small, water-soluble, and colourless compounds that can absorb UV radiation. They contain amino acids linked to characteristic ring structures (cyclohexenone or cyclohexenimine), which create different types of MAAs. These structural differences affect how they absorb UV light. MAAs contribute to cellular protection by absorbing UV radiation and releasing the energy as heat. Because of these properties, some MAAs are already used in cosmetic products such as sunscreens. This review synthesises the literature on the chemical diversity and photochemical properties of cyanobacterial MAAs, their biosynthetic pathways and regulation, their distribution among cyanobacterial taxa, and their potential biotechnological and biomedical applications. Current evidence links MAA biosynthesis to the 4-deoxygadusol precursor and the mys gene cluster. Studies also indicate that light quality and intensity, UV-B exposure, salinity, desiccation, and nutrient availability influence MAA accumulation and composition. Reported photoprotective and antioxidant activities support interest in MAAs as potential ingredients for sunscreens and personal-care products. However, the strength of the evidence varies among compounds and experimental systems, and commercial development remains constrained by limited methodological standardization, production economics, and insufficient safety and regulatory data. Ongoing research efforts focus on identifying new MAAs and cyanobacterial producers to support the development of more effective photoprotective formulations. Overall, this review provides an overview of MAA-producing cyanobacteria and highlights their potential for future research and biotechnological applications.