Biotechnology Journal International

Genetic and Non-genetic Factors Affecting Heat Production in Farm Animals

Muslim Kayode Ewuola — 2026-07-13

Farm animals produce heat through a complex biological process that is influenced by their environment, genetics, metabolism, nutrition, and management. Heat stress is a condition that imposes quantifiable consequences on productivity, reproduction, immunological function, and animal welfare across all major livestock species when heat output exceeds dissipation capability. This review examines the biological and environmental factors influencing heat production and heat stress in major farm animal species, including dairy and beef cattle, swine, poultry, water buffalo, sheep, goats, camels, horses, and rabbits. The present review was conducted using secondary sources derived from existing academic literature, including peer-reviewed journal articles, books, and conference proceedings. Each species has distinct vulnerabilities. The fleece that provides sheep with resistance to cold weather also traps metabolic heat in warm weather, a phenomenon known as the "fleece insulation paradox." Although goats have a more flexible thermoregulatory system, prolonged exposure to high humidity can still pose a serious threat to their health. Camels' exceptional heterothermic traits distinguish them from other domestic ruminants. Horses rely primarily on sweat-based cooling at rates that rapidly deplete electrolytes, and they produce exercise-induced heat loads surpassing 1,000 W, an intensity unmatched by other domestic species. With their thin insulating coat, lack of functional sweat glands, and dependence on panting, which becomes ineffective above 28–30°C, rabbits are possibly the most thermally sensitive commonly farmed animal. This review critically evaluates evidence-based mitigation strategies across all ten species, including nutritional interventions, cooling technologies, genetic selection approaches, and real-time monitoring systems, with attention to the diversity of production environments in which these strategies can be applied.

Fermentation and Nutrient Bioavailability in Indigenous Crops: A Critical Review of Protein Quality, Glycaemic Response, and Micronutrient Enrichment for Snack Food Applications

Chidinma A. Okafor — 2026-08-01

Indigenous and underutilised crops such as sorghum, the millets, teff, fonio, cowpea, Bambara groundnut and the Andean pseudocereals combine dense micronutrient profiles with substantial phytate, tannin and protease-inhibitor loads that constrain their nutritional performance in unprocessed form. Fermentation is among the oldest and most widely practised interventions used to reconcile this tension, yet the literature addressing its effects remains fragmented across single-crop studies, single-outcome assays and disciplinary silos that rarely intersect with food product development. This review synthesises evidence on three interconnected outcome domains, namely protein digestibility and amino acid availability, glycaemic and starch-digestibility response, and mineral and vitamin bioavailability, and evaluates the extent to which fermentation-derived improvements in these domains can be translated into indigenous-crop snack foods. Evidence was drawn from peer-reviewed journal articles and institutional sources identified through structured searches of publicly accessible bibliographic platforms. Across crops and fermentation modalities, spontaneous and lactic-acid-bacteria-mediated fermentation consistently reduced phytate and condensed tannin concentrations and improved in vitro protein digestibility, with reported gains that varied considerably by substrate, microbial consortium and fermentation duration. Effects on glycaemic response were less uniform, reflecting a balance between organic-acid-mediated suppression of starch hydrolysis and matrix disruption that can accelerate it. Mineral bioaccessibility gains, expressed principally through reductions in phytate-to-mineral molar ratios, were the most consistently reported benefit, although evidence remains concentrated in a small number of crop-microbe combinations and in vitro assay systems. Extrusion and other snack-relevant processing steps interact with fermentation in ways that are only beginning to be characterised, and few studies have evaluated fermented indigenous-crop snacks under conditions resembling commercial manufacture. The review identifies methodological heterogeneity, limited in vivo confirmation, and a scarcity of studies that integrate all three outcome domains within a single product-development framework as the principal constraints on translating this evidence base into viable snack food innovation.

Joint Effects of Water-Miscible Solvents on Kluyveromyces marxianus Cell-Free β-Galactosidase Activity

Oluchukwu Roseline Nweke — 2026-07-08

Aim: The study aims to assess the inhibitory effects of ethanol-N,N-dimethylformamide (DMF) and ethanol-dimethyl sulfoxide (DMSO) binary mixtures on Kluyveromyces marxianus cell-free β-galactosidase activity.

Study design: A cell-free enzyme assay integrating concentration-response modelling with mixture-toxicity analysis was used to characterize the inhibitory effects of ethanol, DMSO, DMF and their binary mixtures on Kluyveromyces marxianus β-galactosidase activity.

Methods: No-observable-effect concentration (NOEC) and median inhibitory concentration (EC₅₀) limits were calculated by fitting concentration-response relationships for the individual solvents and mixtures to a Gompertz model. Values generated from the prediction models are presented as mean ± standard deviation. One-way analysis of variance (ANOVA), followed by Duncan's post hoc test, was used to determine significant differences among treatments.

Results: The NOEC values for ethanol, DMSO and DMF were 2.651 ± 0.796%, 2.215 ± 0.309% and 0.920 ± 1.161%, respectively. The corresponding EC₅₀ values were 18.930 ± 1.171%, 19.114 ± 0.534% and 13.587 ± 0.489%, respectively, giving an inhibition order of DMF > DMSO ≥ ethanol. Ethanol-DMSO and ethanol-DMF mixtures with higher EC₅₀ and NOEC values showed lower inhibitory effects than the individual solvents, particularly DMF and DMSO. The toxic index (TI) and concentration addition (CA) model were used to predict the inhibitory effects of ethanol-DMF and ethanol-DMSO mixtures. The CA-predicted EC₅₀ values of ethanol-DMSO and ethanol-DMF mixtures ranged from 18.880 ± 1.444 to 18.897 ± 1.604 and from 18.525 ± 0.886 to 22.664 ± 1.099, respectively. TI values for ethanol-DMSO mixtures ranged from 1.018 ± 0.014 to 1.062 ± 0.021. Ethanol-DMF mixtures at ratios of 9:1 and 8:2 indicated synergistic effects, whereas ratios of 7:3 and 6:4 indicated additive effects. For TI values marginally above 1, the joint effect was adjudged additive because the observed EC₅₀ values were not significantly different from the CA-predicted EC₅₀ values.

Conclusion: This study provides foundational information for establishing sub-inhibitory concentrations of water-miscible solvents for the in situ β-galactosidase activity assay derived from Kluyveromyces marxianus.

Can Coir Pith-Starch-Plant Growth Promoting Rhizobacteria Composite Sustain Zea mays Seedling Survival and Growth under Flood (Waterlog) Condition?

Chinyere Augusta Ajuzieogu — 2026-07-10

Aim: This study was conducted to formulate and evaluate the efficacy of a composite: coir pith + starch + plant-growth-promoting rhizobacteria (PGPR), in sustaining the survival and growth of Zea mays (maize) seeds cultivated under flood stress.

Place and Duration of Study: Department of Microbiology Laboratory, Federal University Otuoke, Bayelsa State, Nigeria, between May and July 2024.

Methodology: Rhizobacteria were isolated, screened for plant-growth-promoting (PGP) traits; phosphate solubilisation and indole-3-acetic acid (IAA) production and further tested for PGP activity via seed germination bioassay. Composites were prepared by homogenizing coir pith, starch gel and standardized PGPR inoculum at a ratio of 2:24:20 (w/v), pelleted and dried at 28^oC. The efficacy of the composites was examined in a pot experiment by measuring shoot length (SL), root length (RL) and plant height (PH), of the treated maize seeds. Treatments were conducted in two sets (single composite pellet and 4 composite pellets); Set 1 (seeds + 1 composite pellet/pot, Control 1 and Control 2), Set 2 (seeds + 4 composite pellets/pot, Control 1 and Control 2). Controls 1 and 2 were; seeds + coir pith + starch only and maize seeds only, respectively. Set 1 was monitored for 2 weeks, and Set 2 for 7 days. Flood conditions were simulated by saturating the pots with water, without drainage, for 3 days.

Results: Five rhizobacteria were isolated; LCE tested positive for IAA production and phosphate solubilisation, SPP tested positive for IAA production only, and C tested positive for phosphate solubilization only. The growth performance of treated maize seeds under waterlogged condition in Set 1 indicated that the Control 1 (maize seeds + 1 coir pith + starch only pellet) was more effective than Control 2 and the other composites. The treatments in Set 1 did not support maize seed growth throughout the two-week monitoring period, except control 1 (maize seeds + 1 coir pith +starch only) which sustained seed survival and growth for 2 weeks. One way ANOVA indicated that the mean growth for control 1 was the same across the weeks as the p-value (p = 0.658) is greater than the 5% significance level (α = 0.05). In Set 2, at day 7, the observed survival and growth of maize seeds treated resulted from the application of 4 coir pith+starch+LCE (Priestia flexa) pellets. The mean SL, RL and PH recorded for the seeds were 2.6±0.2, 3.6±0.45 and 15.9±0.45 cm, respectively. LCE was identified by 16S rRNA sequencing as Priestia flexa.

Conclusion: This study demonstrates the potential of coir pith+ starch+Priestia flexa to mitigate waterlogging stress, sustain survival and growth of Zea mays seedlings.

Biotransformation of Unsold Mangoes and Cashew Apples by Acetic Acid Bacteria Isolated from Fermented Beverages

Constant Kouadio Attchelouwa — 2026-08-03

Aims: The recovery of agricultural waste is regarded as a strategy for reducing its environmental impact while generating high value-added products. Thus, this study aimed to evaluate the potential of acetic acid bacteria isolated from fermented beverages to biotransform unsold mangoes and cashew apples for their valorisation through the production of organic acids.

Methodology: For this purpose, the technological properties of Acetobacter pasteurianus and Acetobacter oryzoeni strains isolated from traditional beverages (tchapalo and palm wine) were evaluated by assessing their growth at different temperatures (30, 37, and 44°C) and ethanol concentrations (2, 4, 6, 8, 10, 15, and 20%, v/v). Furthermore, the ability of these acetic acid bacteria to acidify cashew apple juice (the pseudofruit of Anacardium occidentale L.) and mango juice (Mangifera indica cv. Kent) was investigated in the presence and absence of ethanol.

Results: The results showed that Acetobacter pasteurianus and Acetobacter oryzoeni exhibited optimal growth at 30°C and 37°C. Organic acid production was higher at 37°C, where titratable acidity increased from 0.42 to 0.96% for A. pasteurianus and from 0.33 to 1.13% for A. oryzoeni. Ethanol concentrations of 4% and 6% promoted substantial organic acid production. In fermented juices without ethanol supplementation, titratable acidity was higher in cashew apple juice than in mango juice. However, in the presence of ethanol, titratable acidity was higher in mango juice.

Conclusion: A. pasteurianus and A. oryzoeni demonstrated strong technological potential for the biotransformation of mango and cashew apple juices. The findings suggest that cashew apple juice may preferentially support gluconic acid production, whereas mango juice may be more favourable for acetic acid production by acetic acid bacteria. However, these interpretations are based on indirect physicochemical indicators (pH, titratable acidity, and total soluble solids), and further studies involving direct quantification of organic acids are needed to confirm the metabolic pathways involved.

Genome-wide Identification of the CsnsLTP Gene Family in Cucumber and Expression Profiling in Response to Corynespora cassiicola

Zijuan Huang — 2026-07-28

Aims: This study aims to characterise the molecular properties and structural features of the non-specific lipid transfer protein (CsnsLTP) gene family and to analyse its expression patterns in cucumber. Candidate CsnsLTP genes that may contribute to resistance to Corynespora cassiicola infection will be identified and may provide valuable genetic resources for molecular breeding against cucumber target leaf spot disease.

Study Design: The resistant cultivar Jinyou 38 and the susceptible cultivar Xintaimici were used as plant materials. Seedlings at the two-leaf and one-bud stage were inoculated with C. cassiicola. Samples were collected at eight time points spanning 0–144 h post-inoculation. CsnsLTP family members were identified through a combination of bioinformatic and expression analyses, and their infection-responsive characteristics were subsequently characterised.

Methodology: Thirteen CsnsLTP genes were retrieved from the NCBI database. Multiple bioinformatic tools, including ExPASy, CELLO, MEGA, MEME, NCBI Batch CD-Search, and TBtools, were used to systematically characterise the deduced proteins, including their physicochemical properties, subcellular localisation, phylogenetic relationships, chromosomal distribution, conserved motifs, conserved domains, and exon–intron gene structures.

Reverse transcription quantitative PCR (RT-qPCR) was then used to quantify the relative transcript abundance of all target genes in resistant and susceptible cucumber cultivars at distinct time points after C. cassiicola inoculation.

Results: The 13 CsnsLTP genes were unevenly distributed across chromosomes 1, 3, 4, 5, and 7 and exhibited significant variation in their physicochemical properties. Subcellular localisation predictions indicated that most encoded proteins were localised to the plasma membrane, although some were also predicted to reside in the cell wall, chloroplasts, and other compartments. Phylogenetic analysis classified the family members into three subfamilies, with Motif 1 identified as a conserved motif shared by subfamilies II and III. Expression profiling revealed that CsnsLTP1, CsnsLTP4, CsnsLTP5, CsnsLTP7, CsnsLTP8, CsnsLTP9, CsnsLTP10, CsnsLTP12, and CsnsLTP13 were significantly differentially expressed between resistant and susceptible cultivars following C. cassiicola infection, suggesting that they are candidate genes associated with resistance to target leaf spot in cucumber.

Conclusions: This study identified 13 CsnsLTPs in cucumber and systematically characterised their molecular and structural features. Pathogen-induced expression screening identified nine candidate resistance-associated genes. These findings provide candidate genes and a theoretical basis for the molecular genetic improvement of target leaf spot resistance in cucumber.