Research Articles (Biotechnology)

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Afriplex GRTTM extract attenuates hepatic steatosis in an in vitro model of NAFLD
(Public Library of Science, 2024) Gabuza, Kwazi; Mabuda, Thendo Innocent; Patel, Oelfah
Currently, it is acknowledged that vitamin E, insulin sensitizers and anti-diabetic drugs are used to manage non-alcoholic fatty liver disease (NAFLD), however, these therapeutic interventions harbour adverse side effects. Pioglitazone, an anti-diabetic drug, is currently the most effective therapy to manage NAFLD. The use of natural medicines is widely embraced due to the lack of evidence of their negative side effects. Rooibos has been previously shown to decrease inflammation and oxidative stress in experimental models of diabetes, however, this is yet to be explored in a setting of NAFLD. This study was aimed at investigating the effects of an aspalathin-rich green rooibos extract (Afriplex GRTTM) against markers of hepatic oxidative stress, inflammation and apoptosis in an in vitro model of NAFLD. Oleic acid [1 mM] was used to induce hepatic steatosis in C3A liver cells. Thereafter, the therapeutic effect of Afriplex GRTTM, with or without pioglitazone, was determined by assessing its impact on cell viability, changes in mitochondrial membrane potential, intracellular lipid accumulation and the expression of genes and proteins (ChREBP, SREBF1, FASN, IRS1, SOD2, Caspase-3, GSTZ1, IRS1 and TNF-α) that are associated with the development of NAFLD.
Antioxidant and antimicrobial activities of green-synthesized silver nanoparticles using a cocktaila aqueous extract of capparis sepiaria root and tabernaemontana elegans bark
(Wiley, 2025) Mashilo, Cate M.; Sibuyi Nicole RS; Botha, Subelia; Meyer, Mervin; Madiehe, Abram M
The increasing incidence of antimicrobial resistance (AMR) poses a serious threat to public health, which necessitates the development of alternative countermeasures to combat it. Green nanotechnology, in particular the use of silver nanoparticles (AgNPs), shows promise in combating AMR. Although the synthesis of AgNPs using medicinal plant extracts has been explored, combining extracts from two medicinal plants to synthesize AgNPs with enhanced properties has received less attention. Therefore, this study addresses this gap by presenting the green synthesis of AgNPs using a cocktail of Capparis sepiaria–Tabernaemontana elegans (CsTe) aqueous extract as reducing, stabilizing, and capping agents. The focus is on assessing the antioxidant and antimicrobial activities of the synthesized CsTe-AgNPs. Various parameters, such as pH, temperature, extract and silver concentrations, reaction ratio, and synthesis time, were optimized to enhance the efficiency of CsTe-AgNPs synthesis. The CsTe- AgNPs were monodispersed and spherical, with an average core size of 14 ± 2.953 and 7 ± 3.849 nm, and hydrodynamic size of 23 ± 12.260 and 138 ± 2.086 nm for pH = 6 and pH = 11, respectively. The FTIR analysis revealed a shift in peaks of biomolecules present in the CsTe extracts that could be responsible for the reduction of Ag salt to form CsTe-AgNPs. Notably, CsTe-AgNPs_pH11 had potent antimicrobial activity, with a minimum inhibitory concentration (MIC) of 12.5 ± 0 μg/mL against K. pneumoniae and P. aeruginosa, and a slightly higher MIC for C. albicans of 25 ± 5.449 μg/mL. This study demonstrated the effectiveness of using a mixture of two extracts to synthesize AgNPs with enhanced antioxidant and antimicrobial activities, and therefore, could serve as a promising reagent to combat AMR.
Biomolecular affinities and cytotoxicity of copper(I) and silver(I) phosphine–pyridinyl complexes against CACO-2 and CASKI cell lines
(John Wiley and Sons Inc, 2025) Meyer, Miche D; Sibuyi, Nicole R. S; Onani, Martin O
A series of three copper (I) and three silver (I) complexes with the general formula [M L(PPh3)2]NO3, (M = Cu for complexes 1–3 and Ag for complexes 4–6) are synthesized by reacting copper(I) or silver(I)-nitrate and triphenylphosphine with the bidentate ligands, (E)-1-(pyridin-2-yl)-N-(o-tolyl)methanimine L1, (E)-N-isopropyl-1-(pyridine-2-yl)methanimine L2, or (E)-N-(2,6-dimethylphenyl)-1-(pyridine-2-yl)methanimine L3. The structures of these complexes are elucidated using a combination of NMR spectroscopy, FTIR, UV–visible, mass spectrometry, elemental analysis, and single-crystal X-ray diffraction. Structural analysis revealed that the Schiff bases coordinate to the metal centers in a bidentate fashion, with triphenylphosphine occupying the remaining coordination sites in complexes 1, 2, and 5. In contrast, in complexes 3, 4, and 6, one coordination site is occupied by a nitrate anion instead of triphenylphosphine. All six complexes exhibit a distorted tetrahedral geometry around the metal center, as confirmed by τ4 values ranging from 0.54 to 0.87. Binding studies with calf-thymus DNA demonstrated that complexes 1–6 interact via intercalation, with complex 5 exhibiting the highest binding constant. Furthermore, all complexes showed strong binding affinity toward bovine serum albumin. Cytotoxicity studies revealed significant cytotoxicity of complexes 1–6 against human colon adenocarcinoma (Caco-2) and human cervical epidermoid carcinoma (Caski) cell lines.
Carbon dynamics in termite mounds: the effect of land use on microbial oxalotrophy
(Elsevier B.V., 2025) Trindade, Marla; Nel, Teneille; Clarke, Catherine E
The semi-arid western region of South Africa hosts extensive earthen mounds known as heuweltjies, which are inhabited by Microhodotermes viator termites and play a critical role in soil biogeochemical cycling. These mounds accumulate significant stores of soil organic and inorganic carbon (C), including pedogenic calcium carbonate, which may form through microbially induced calcite precipitation. In this study, the effects of land use change on C dynamics in heuweltjie soils were assessed by examining soil biogeochemistry and apparent respiratory quotient (ARQ, based on soil pore gas composition). We investigated the oxalate-carbonate pathway (OCP) as a potential mechanism of C sequestration. Topsoils were collected from one pristine and one cultivated termite mound in a semi-arid region of South Africa and incubated for one week. The carbon dioxide (CO2) and oxygen concentrations of soil pore gas as well as chemical properties of soils treated with termite frass (excrement) or calcium oxalate (CaOx) were monitored. Increases in pH and the calcite saturation index in both CaOx- and frass-treated soils suggested the potential occurrence of the OCP. The ARQ values did not reflect geochemical changes associated with OCP due to competing metabolic pathways, such as potential lignin degradation in frass-treated soils. Higher ARQ values in uncultivated versus cultivated CaOx-treated soils may indicate higher carbon use efficiency in uncultivated soils or destabilization of existing C in cultivated soils. Respiration in frass-treated soils was higher than control and CaOx-treated soils and resulted in production of bicarbonate (via dissociation of carbonic acid formed by dissolution of respired CO2 in water). This implies that termite-affected landscapes may sequester C in inorganic form. Increased total C in both cultivated and uncultivated soils treated with frass suggests that microbial CO2-fixation may occur in termite-affected landscapes, necessitating further investigation of pathways responsible for this process.
Characterization of Zalaria obscura Y1223 hydrolases: implications for lignocellulose conversion
(Springer Science and Business Media Deutschland GmbH, 2025) Boonzaier, Jeremy J.; den Haan, Riaan; Hart, Rodney S.
Overconsumption of fossil fuel reserves and its adverse effects has sparked interest in the production of second-generation biofuels due to the abundance of lignocellulosic waste and potential energy crops. However, processing costs associated with depolymerization of the cellulose crystalline structure have stalled advancement in cellulosic ethanol production. Current investigations range from identification of novel enzymes for lignocellulose hydrolysis to consolidation of enzyme production into a singular alcohol producing microorganism to potentially reduce cost for commercial processing. In this study, a total of 828 non-Saccharomyces and black yeasts were screened for cellulolytic and xylanolytic enzyme activities, whereby 60 isolates were identified that exhibited activity for at least one of the enzymes tested. In doing so, a novel Zalaria obscura strain (Z. obscura Y1223) was identified and assessed for enzyme activity in multiple growth media. Semi-quantitative assays showed that Z. obscura Y1223 produced cellulases optimally in media containing yeast extract, peptone and oat bran, with a pH range between pH 5 and 6 and at 30 °C. Maximum xylanase activity (20.5 U/L/OD600) was attained using synthetic complete media supplemented with xylo-oligosaccharides and maximum cellulase activity (7.51 U/L/OD600 endoglucanase, 1.302 U/L/OD600 β-glucosidase) was attained when grown in media containing yeast extract, peptone and oat bran. To our knowledge, this is the first study to quantify the cellulolytic and xylanolytic enzyme activities of a Zalaria spp., which provides key insight into the availability of unexplored cellulolytic enzymes that could inform the design of organisms engineered for consolidated bioprocessing.
Delphinidin as an antineoplastic agent targeting androgen receptors
(Wiley, 2025) Fadaka Adewale; Sibuyi Nicole; Alves Leandro
Researchers globally have discovered that both red and green peppers are extremely rich in bioactive phytoconstituents with pharmacological properties. These metabolites are associated with critical physiological functions, including anticancer and health-promoting effects. However, due to insufficient clinical evidence or lack of standardized studies, there are no recommendations regarding their use and dosage. We investigated the potential therapeutic effects of Capsicum chinense flesh as an inhibitor of the androgen receptor through computational studies. To explore potential novel antitumor markers from Capsicum chinense flesh, we employed in silico docking, molecular dynamics simulations, and principal component analysis. Our results consistently demonstrated significant binding across all the receptor models tested, with the potential candidate (Delphinidin) emerged as a promising candidate. This study offers valuable insights into a robust pharmacological approach that could aid in identifying targets with investigative roles in tumor development and provide potential therapeutic options for managing tumors and associated challenges.
Discovering new genes for alfalfa (Medicago sativa) growth and biomass resilience in combined salinity and Phoma medicaginis infection through GWAS
(Switzerland: Frontiers Media S.A, 2024) Wiem Mnafgui; Ndomelele Ndiko Ludidi; Gerhard Basson3
Salinity and Phoma medicaginis infection represent significant challenges for alfalfa cultivation in South Africa, Europe, Australia, and, particularly, Tunisia. These constraints have a severe impact on both yield and quality. The primary aim of this study was to establish the genetic basis of traits associated with biomass and growth of 129 Medicago sativa genotypes through genome-wide association studies (GWAS) under combined salt and P. medicaginis infection stresses. The results of the analysis of variance (ANOVA) indicated that the variation in these traits could be primarily attributed to genotype effects. Among the test genotypes, the length of the main stem, the number of ramifications, the number of chlorotic leaves, and the aerial fresh weight exhibited the most significant variation. The broad-sense heritability (H²) was relatively high for most of the assessed traits, primarily due to genetic factors. Cluster analysis, applied to morpho-physiological traits under the combined stresses, revealed three major groups of accessions. Subsequently, a GWAS analysis was conducted to validate significant associations between 54,866 SNP-filtered single-nucleotide polymorphisms (SNPs) and seven traits. The study identified 27 SNPs that were significantly associated with the following traits: number of healthy leaves (two SNPs), number of chlorotic leaves (five SNPs), number of infected necrotic leaves (three SNPs), aerial fresh weight (six SNPs), aerial dry weight (nine SNPs), number of ramifications (one SNP), and length of the main stem (one SNP). Some of these markers are related to the ionic transporters, cell membrane rigidity (related to salinity tolerance), and the NBS_LRR gene family (associated with disease resistance). These findings underscore the potential for selecting alfalfa genotypes with tolerance to the combined constraints of salinity and P. medicaginis infection.
Effects of acidic and alkaline electrolyzed water treatments on the volatilomics and proteomics changes in fresh-cut apple during storage
(Royal Society of Chemistry, 2025) Caleb, Oluwafemi James; Belay, Zinash A.; Nkomo, Mbukeni
Electrolyzed water (EW) has shown potential to decontaminate and maintain the quality of fresh-cut apple; however, the underlying response of the product to this treatment remains unclear. Thus, this study aims to identify the possible quality regulation mechanisms of acidic electrolyzed water (AEW) and alkaline electrolyzed water (ALEW) treatments on fresh-cut ‘Granny Smith’ apples via volatile organic compound (VOC) and qualitative proteomics analysis during storage at 2 °C for 10 days. The results identified 43 VOCs, including 10 esters, 9 alcohols, 9 alkanes, 8 carboxylic acids, 6 ketones, and 1 aldehyde. The distribution of VOCs was significantly affected by the pretreatment conditions; fresh-cut apple treated with AEW was characterised by the highest number of esters, alcohols, and carboxylic acids, whereas samples treated with ALEW exhibited predominantly carboxylic acids, alcohols, and alkanes in comparison to control (untreated) samples. Ethyl dodecanoate, which was identified only in the ALEW samples on each sampling day, had the highest concentration among all the individual VOCs. The proteomics results showed that a total of 3434, 3401, and 3313 proteins were identified on day 3, 6, and 10, respectively, across all samples. Until day 6 of storage, no significant differences were observed among the samples. Notably, on day 6, “M16C_associated domain-containing protein” was shown to be unique to the control samples. KH type-2 domain-containing protein, methylenetetrahydrofolate reductase (MTHFR), and 1,4-alpha-glucan branching enzyme were unique proteins identified after AEW treatment at day 6 and 10 of storage. No unique protein was identified for the ALEW samples. These results provide the first report of the proteomic and volatilomic changes associated with EW-treated fresh-cut apple during storage. Data are available via ProteomeXchange with identifier PXD056621. © 2025 RSC.
Effects of acidic and alkaline electrolyzed water treatments on the volatilomics and proteomics changes in fresh-cut apple during storage
(Royal Society of Chemistry, 2025) Mohamed, Gadija; Caleb, Oluwafemi James; Belay, Zinash A.
Electrolyzed water (EW) has shown potential to decontaminate and maintain the quality of fresh-cut apple; however, the underlying response of the product to this treatment remains unclear. Thus, this study aims to identify the possible quality regulation mechanisms of acidic electrolyzed water (AEW) and alkaline electrolyzed water (ALEW) treatments on fresh-cut ‘Granny Smith’ apples via volatile organic compound (VOC) and qualitative proteomics analysis during storage at 2 °C for 10 days. The results identified 43 VOCs, including 10 esters, 9 alcohols, 9 alkanes, 8 carboxylic acids, 6 ketones, and 1 aldehyde. The distribution of VOCs was significantly affected by the pretreatment conditions; fresh-cut apple treated with AEW was characterised by the highest number of esters, alcohols, and carboxylic acids, whereas samples treated with ALEW exhibited predominantly carboxylic acids, alcohols, and alkanes in comparison to control (untreated) samples. Ethyl dodecanoate, which was identified only in the ALEW samples on each sampling day, had the highest concentration among all the individual VOCs. The proteomics results showed that a total of 3434, 3401, and 3313 proteins were identified on day 3, 6, and 10, respectively, across all samples. Until day 6 of storage, no significant differences were observed among the samples. Notably, on day 6, “M16C_associated domain-containing protein” was shown to be unique to the control samples. KH type-2 domain-containing protein, methylenetetrahydrofolate reductase (MTHFR), and 1,4-alpha-glucan branching enzyme were unique proteins identified after AEW treatment at day 6 and 10 of storage. No unique protein was identified for the ALEW samples. These results provide the first report of the proteomic and volatilomic changes associated with EW-treated fresh-cut apple during storage.
Effects of ZnO nanoparticles concentration on the morphology and textural properties of ZnO/NiFe2O4 nanocomposite
(Elsevier B.V., 2025) Daniel, Augustine Innalegwu; Keyster, Marshall; Tijani, Jimoh Oladejo
The aim of this study is to synthesize and characterize ZnO and NiFe2O4 nanoparticles via green route and co-precipitation of ZnO/NiFe2O4. X-ray diffraction (XRD) data show no extra diffraction peaks belonging to other phases except wurtzite. High resolution transmission electron microscopy (HRTEM) images showed that the average interplanar distance of wurtzite phase at 3, 5, and 7 % dopant concentration were about 0.28, 0.44 and 0.33 nm respectively. X-ray photoelectron spectroscopy (XPS) results show difference in binding energies of the elements present in different concentration of the dopants. Electron Energy Loss Spectroscopy (EELS) spectra show similarities in the shape of Zn, Fe and Ni from zero loss, low loss and core loss region with a little shift in energy. All the elements exhibit multiple oxidation state; +2 and +3 for Fe and +1 and +2 for Zn and Ni. Brunauer-Emmett-Teller (BET) plot shows that ZnO belongs to the type II isotherm curve while NiFe2O4 and 3, 5 and 7 % ZnO/NiFe2O4 all belong to type IV isotherm curve indicating ZnO as macroporous while NiFe2O4 and different dopant concentration of ZnO/NiFe2O4 are mesoporous. The study shows the complete synthesis of ternary ZnO/NiFe2O4 nanocomposites using green synthesis and sol-gel approach. • Green synthesis of ZnO and NiFe2O4 using leaf extract of Anacardium occidentale • Co-precipitation method at different concentration of ZnO and NiFe2O4 for the synthesis of ZnO/NiFe2O4. • Nanocomposites was characterized using different analytical tools
Enhanced lactic acid production from potato peel waste via MnO2 nanoparticle-assisted simultaneous saccharification and fermentation: Process optimization and kinetic studies
(Elsevier, 2025) Mambili-Mamboundou Hermane; Naidu Talia; Sanusi Isaac A.
This study focused on optimizing lactic acid production from potato peel waste facilitated by MnO2 nanoparticle (NP). Also, kinetic analysis was conducted, utilizing the growth constant (Kg), logistic function, and modified Gompertz model to evaluate the process dynamics under optimized conditions and the control experiment (without NP). Under optimized conditions (0.034 wt% MnO2 NP, 6.02 pH, 34 ◦C temperature, and 14.90 wt% solid loading), notable increases in biomass and lactic acid concentrations of 2.85 g/L and 41.26 g/L were achieved representing a 1.16 and 1.42-fold increments respectively. In addition, the inclusion of MnO2 NP increased the maximum potential lactic acid concentration (Pm) and production rate, reaching 32.89 g/L and 1.51 g/L/h, respectively, compared to the control’s values of 29.80 g/L and 1.43 g/L/h. This study underscores the potential of MnO2 NP in boosting lactic acid bioprocessing and yield towards enhanced bioconversion of agricultural waste to useful products.
Enhancing Fusarium oxysporum tolerance in Phaseolus vulgaris: Isolation and characterization of bacterial endophytes
(Elsevier B.V., 2025) Holman, Darin Edward; Keyster, Marshall; Klein, Ashwil; Daniel, Augustine Innalegwu
Research surrounding microbial biocontrol has garnered considerable attention in the last few years due to the numerous advantages as opposed to synthetic agrochemicals. Phaseolus vulgaris is an important legume that is cultivated worldwide, especially in third-world countries. The growth and yield of this crop are often severely limited by the pathogen Fusarium oxysporum. The aim of the study is to investigate the biological control potential of six plant bacterial isolates against F. oxysporum, both in vitro and in vivo. Six bacterial endophytes were isolated from Ledebouria ovatifolia leaves (E1), Solanum dulcamara leaves (E2), Cortalaria retusa leaves (E3), Euphorbia prostrata roots (R1), Solanum nigrum roots (R2), and Helichrysum splendidum roots (R3). These isolates were characterized for any biocontrol activity they might have against F. oxysporum PPR1. Isolation, characterization, identification, and biocontrol antagonistic assays were carried out in vitro against F. oxysporum, following standard protocols. The isolates were identified using 16S rRNA gene PCR sequencing. A phylogenetic analysis indicated that the leaf isolates displayed a close relationship with Bacillus altitudinis (E1), Streptomyces bikiensis strain SBM (E2), and Pseudomonas rhodesiae (E3). Root isolates displayed a close relationship with Enterobacter kobei (R1), Enterobacter sp. (R2), and Pseudomonas sp. strain (R3). Five out of the six isolates exhibited catalase activity and zinc solubilization activity, whereas all isolates exhibited siderophore production activity. Most of the tested isolates were able to produce the extracellular hydrolytic enzymes protease and amylase. The isolates exhibiting the highest hydrolytic enzyme activities were able to significantly inhibit F. oxysporum growth in vitro. E. kobei exhibited the most promising plant growth-promoting activity, hydrolytic enzyme activity, F. oxysporum antagonism, and increased seedling growth of P. vulgaris. These results suggest that E. kobei represents a good biocontrol candidate against F. oxysporum. The ability of this bacterial isolate to colonize and its promising biological activities suggest it has enormous potential to be used as both a biopesticide and plant growth stimulator.
Ferrocene-based hybrid drugs as potential anticancer and antibacterial therapeutic agents for incorporation into nanocarriers: in silico, in vitro, molecular docking evaluations
(MDPI AG, 2025) Oselusi Samson; Peter Sijongesonke; Morifi Eric; Nwamadi Mutshinyalo
Cancer and bacterial cases are increasing. Hence, new drugs to treat these diseases are paramount. Ferrocene-based hybrid compounds were synthesizedas potential cancer and bacteria therapeutics. The synthesized compounds were characterized via FTIR, NMR, and LC-MS and evaluated against different cancer cells and bacterial strains. Moreover, computational studies of these compounds were conducted using several silico tools. Among the synthesized compounds, hybrid 10 was the most promising compound, displaying promising anticancer activity with IC50 values between 42.42 and 45.37 and 50.64 and 73.37 µg/mL against HeLa and CHO cancer cells, respectively, with a selective index greater than one on HeLa cancer cells. Compounds 22–26 displayed promising antibacterial activity with a MIC value of 7.8125 µg/mL against most bacterial strains in vitro. The in silico results revealed that this compound has strong binding affinities for 4qtb, 3eqm, and 2w3l cervical cancer proteins, exhibiting binding energies of −7.3, −8.7, and 7.4 kcal/mol, respectively. Furthermore, hybrid 10 showed promising pharmacokinetics and drug-like properties, including high GI absorption, moderate water solubility, favoring the oral administration route, nontoxicity, and is a P-gp substrate. The findings obtained in this study illustrate that hybrid compounds are potential therapeutics that need to be explored. The compounds also contained functionalities relevant for incorporating into nanocarriers to improve their biological activities further. Therefore, further studies are recommended for the most effective compounds to reinforce these findings.
Fimsbactin siderophores from a South African marine sponge symbiont, marinomonas sp. PE14-40
(John Wiley and Sons Ltd, 2025) Ikegwuoha, Nompumelelo Philile Praiseworth; Hanekom, Thea; Booysen, Elzaan; Jason, Corbyn; van Zyl, Leonardo Joaquim; Trindade, Marla
Low iron levels in marine habitats necessitate the production of structurally diverse siderophores by many marine bacterial species for iron acquisition. Siderophores exhibit bioactivities ranging from chelation for iron reduction in hemochromatosis sufferers to antimicrobial activity either in their own right or when coupled to known antibiotics for targeted delivery or for molecular imaging. Thus, marine environments are a sought-after resource for novel siderophores that could have pharmaceutical or industrial application. The fimsbactins A-F (1–6) are mixed catechol-hydroxamate siderophores that have only been reported to be produced by Acinetobacter species with the fimsbactin biosynthetic gene clusters (BGCs) widespread among species within this genus. Here, we identified a putative fimsbactin BGC from an uncharacterized marine isolate, Marinomonas sp. PE14-40. Not only was the gene synteny not conserved when comparing the pathway from Marinomonas sp. PE14-40 to the fimsbactin BGC from Acinetobacter sp., but five of the core biosynthetic genes found in the canonical fimsbactin BGC are located elsewhere on the genome and do not form part of the core cluster in Marinomonas sp. PE14-40, with four of these, fbsBCDL, colocalized. Through ESI-MS/MS analysis of extracts from Marinomonas sp. PE14-40, the known fimsbactin analogues 1 and 6 were identified, as well as two new fimsbactin analogues, 7 and 8, containing a previously unreported L-lysine-derived hydroxamate moiety, N1-acetyl-N1-hydroxycadaverine. Feeding experiments using stable isotope-label L-lysine provided further evidence of the N1-acetyl-N1-hydroxycadaverine moiety in 7 and 8. The study demonstrates functional conservation in seemingly disparate biosynthetic pathways and enzyme promiscuity's role in producing structurally diverse compounds.
Genome-wide characterization of DREB transcription factors in Medicago truncatula: Insights into their roles in development and abiotic stress response
(Elsevier Inc, 2025) Ndiko, Ludidi; Haddoudi, Loua; Ayadi, Mariem
Dehydration-responsive-element binding (DREB) proteins play a crucial role in drought, salt, and environmental stress tolerance. In this study, we identified and annotated fifty-four DREB genes from the Medicago truncatula genome. These genes were analyzed at the molecular level, focusing on gene classification, genomic organization, phylogeny, synteny, structural features, and expression profiles. Phylogenetic analysis revealed that MtDREB proteins are categorized into six subgroups (A1–A6), with highly conserved motif compositions among them. Expression profiling showed that MtDREB genes are differentially expressed in various plant organs and under abiotic stresses (cold, salinity, and dehydration), with 30 % exhibiting high expression during flowering and development. Data from RNA-seq and microarrays demonstrated that 76 % of MtDREB genes are differentially expressed under at least one stress condition, indicating their involvement in various signaling pathways activated by abiotic stresses. Notably, MtDREB05, primarily induced under osmotic stress, appears to be a promising candidate for improving abiotic stress tolerance. These findings will enhance our understanding of the DREB family and aid in functional validation of DREBgenes in M. truncatula and related forage species.
Glucoselipid biosurfactant biosynthesis operon of rouxiella badensis DSM 100043T: screening, identification, and heterologous expression in escherichia coli
(Multidisciplinary Digital Publishing Institute (MDPI), 2025) Van Zyl Leonardo; Williams Wesley; Burger Anita; Harahap Andre
Rouxiella badensis DSM 100043T had been previously proven to produce a novel glucoselipid biosurfactant which has a very low critical micelle concentration (CMC) as well as very good stability against a wide range of pH, temperature, and salinity. In this study, we performed a function-based library screening from a R. badensis DSM 100043T genome library to identify responsible genes for biosynthesis of this glucoselipid. The identified open reading frames (ORFs) were cloned into several constructs in Escherichia coli for gene permutation analysis and the individual products were analyzed using high-performance thin-layer chromatography (HPTLC). Products of interest from positive expression strains were purified and analyzed by liquid chromatography/electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) and nuclear magnetic resonance (NMR) for further structure elucidation. Function-based screening of 5400 clones led to the identification of an operon containing three ORFs encoding acetyltransferase GlcA (ORF1), acyltransferase GlcB (ORF2), and phosphatase/HAD GlcC (ORF3). E. coli pCAT2, with all three ORFs, resulted in the production of identical R. badensis DSM 100043T glucosedilipid with Glu-C10:0-C12:1 as the main congener. ORF2-deletion strain E. coli pAFP1 primarily produced glucosemonolipids, with Glu-C10:0,3OH and Glu-C12:0 as the major congeners, predominantly esterified at the C-2 position of the glucose moiety. Furthermore, fed-batch bioreactor cultivation of E. coli pCAT2 using glucose as the carbon source yielded a maximum glucosedilipid titer of 2.34 g/L after 25 h of fermentation, which is 55-fold higher than that produced by batch cultivation of R. badensis DSM 100043T in the previous study.
Heterocyclic (pyrazine)carboxamide Ru(II) complexes: structural, experimental and theoretical studies of interactions with biomolecules and cytotoxicity†
(Royal Society of Chemistry, 2024) Tsaulwayo, Nokwanda; Sibuyi, Nicole Remaliah Samantha; Meyer, Mervin
Treatments of N-(1H-benzo[d]imidazol-2-yl)pyrazine-2-carboxamide (HL1) and N-(benzo[d]thiazol-2-yl)pyrazine-2-carboxamide carboxamide ligands (HL2) with [Ru(p-cymene)Cl2]2 and [Ru(PPh3)3Cl2] precursors afforded the respective Ru(ii) complexes [Ru(L1)(p-cymene)Cl] (Ru1), [Ru(L2)(p-cymene)Cl] (Ru2), [Ru(L1)(PPh3)2Cl] (Ru3), and [Ru(L2)(PPh3)2Cl] (Ru4). These complexes were characterized by NMR, FT-IR spectroscopies, mass spectrometry, elemental analyses, and crystal X-ray crystallography for Ru2. The molecular structure of complex Ru2 contains one mono-anionic bidentate bound ligand and display pseudo-octahedral piano stool geometry around the Ru(ii) atom. The interactions with calf thymus DNA (CT-DNA) and bovine serum albumin (BSA) were investigated by spectroscopic techniques. The experimental binding studies suggest that complexes Ru1-Ru4 interact with DNA, primarily through minor groove binding, as supported by molecular docking results. Additionally, these complexes exhibit strong quenching of the fluorescence of tryptophan residues in BSA, displaying static quenching. The in vitro cytotoxicity studies of compounds Ru1-Ru4 were assessed in cancer cell lines (A549, PC-3, HT-29, Caco-2, and HeLa), as well as a non-cancer line (KMST-6). Compounds Ru1 and Ru2 exhibited superior cytotoxicity compared to Ru3 and Ru4.
High-quality genome assembly and annotation of Thalassiosira rotula (synonym of Thalassiosira gravida)
(Nature Research, 2025) Trindade Marla; Di Costanzo F; Di Marsico M
Diatoms are unicellular eukaryotic microorganisms thriving in most aquatic environments thanks to the expression of biosynthetic pathways for secondary metabolites involved in defence and adaptation to environmental changes. The sequencing of the transcriptome of the cosmopolitan diatom Thalassiosira rotula Meunier 1910 (synonym of Thalassiosira gravida Cleve 1896) and of the metagenome of its associated microbiome revealed the presence of biosynthetic pathways synthesising molecules and compounds useful for the algae survival and with potential biotechnological applications. Here we present the genome of a Neapolitan T. rotula strain, which is 672 Mbp in size due to a high proportion of repetitive elements (63.59%) and segmental duplications (14%), while the number of predicted genes resulted to be comparable to that of smaller diatom genomes. DNA methylation was predominantly located in transposable elements.
Identifying promoters to enhance heterologous gene expression in recombinant saccharomyces cerevisiae strains cultivated on non-native substrates
(Springer Science and Business Media Deutschland GmbH, 2025) Fortuin, Jordan; den Haan, Riaan
Abstract: Efficient bioconversion of lignocellulosic biomass (LCB) to ethanol by Saccharomyces cerevisiae requires its engineering to express heterologous enzymes at titres high enough to make significant impacts on industrial consolidated bioprocessing (CBP). Promoters are required for this purpose, but are reportedly influenced by various environmental factors as well as the protein specific nature of expression, warranting the need for assessment under the conditions for which they are intended. Heterologous xylosidase- and xylanase-encoding genes (xln43_SED1 and xyn2) were individually cloned under transcriptional control of the SED1P and TDH3P promoters, and DIT1T terminator, and integrated into the genome of an a S. cerevisiae strain engineered for xylose utilization. Enzymatic assays were used to quantify the performance of the promoters when strains were cultivated on glucose (aerobically and micro-aerobically) and xylose. Additional strains containing both xln43_SED1 and xyn2 under different promoter combinations were then used to allow direct fermentation of beechwood xylan to ethanol in a CBP. The SED1P/DIT1T and TDH3P/DIT1T combinations significantly outperformed the benchmark ENO1P/T under all of the tested cultivation conditions, as well as with regard to growth trials on non-native substrates (xylo-oligosaccharides/XOS and beechwood xylan) and fermentations of beechwood xylan to ethanol. Overall, TDH3P was the best-performing promoter. This study demonstrates that heterologous metabolic pathways and CBP can be significantly enhanced by employing carefully selected promoters tailored to specific conditions.
Interference of a phytoconstituent from Nymphaea lotus-derived ligand N-acetyl glucosamine with signaling receptors in diabetes mellitus development: a targeted computational analysis
(Elsevier B.V., 2025) Fadaka, Adewale Oluwaseun; Onikanni, Sunday Amos; Dao, Tran Nhat-Phong
Diabetes mellitus is a world-wide health concern with several millions affected in all ages. Computer-aided drug design (CADD) is a powerful tool that has revolutionized the process of discovering and developing new drugs. It provides innovative methods that can speed up drug discovery and lower costs thereby results to increase enthusiasm at developing instinctive antidiabetic agents as alternatives for managing diabetes. Nymphaea lotus, a plant with medicinal properties known for its anti-diabetic effects, contains bioactive components like N-acetyl glucosamine. An in silico study was conducted to investigate its potential in targeting proteins related to diabetes. Molecular docking studies, toxicity prediction, examination of drug depiction, and Molecular Dynamics Simulation (MDs) of the ligands with the identified receptor target were conducted using the Schrödinger platform. The receptor-ligand complex of Nymphaea lotus was compared with known inhibitors. Molecular dynamics simulation, principal component analysis, and free energy landscape analysis showed that the binding affinity of the Nymphaea lotus complex was higher than that of reference ligands. This suggests that Nymphaea lotus and its bioactive compounds have promising medicinal value for managing type 2 diabetes, warranting further research into their therapeutic potential

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