Search Results (164)

Microbial fermentation diversely modulates the bioactivity of green tea extracts (GTE), but its effects on anti-aging potential remain under-explored. This study investigated the effects of liquid-state fermentation by Aspergillus niger RAF106 on the anti-aging properties of GTE from Biluochun and identified its longevity-promoting metabolites. The unfermented GTE used herein showed no or limited effects, but the four-day fermented tea extracts (GTE-A4) significantly extended the mean lifespan in Caenorhabditis elegans, enhanced motility and stress resistance, and improved mitochondrial function and antioxidant properties, while reducing lipid accumulation and oxidative damage. The pro-longevity effect depended on insulin/IGF-1, MAPK, and p53 pathways and required transcription factors DAF-16 and HSF-1. Fermentation periods shorter or longer than 4 days led to reduced efficacy. Fermentation with RAF106 dynamically altered chemical composition and induced the enrichment of various longevity-promoting metabolites in GTE-A4, including proanthocyanidin A2, aromadendrin, and dalbergioidin—all newly identified as anti-aging agents. These findings demonstrate that RAF106 fermentation improves the anti-aging potential of green tea and provides a scientific basis for using precision fermentation to develop advanced anti-aging functional ingredients from tea extracts. Full article

This study presents an integrated valorization strategy for oat husks through microwave-assisted pretreatment using a deep eutectic solvent (DES) composed of choline chloride and glycerol (1:2). The process was designed to enhance the release of fermentable sugars, enable xylooligosaccharide (XOS) production, and support inulinase production by Aspergillus niger A42 via submerged fermentation of the hydrolysate and solid-state fermentation of the residual biomass. Response surface methodology (RSM) was applied to evaluate the effects of microwave power, treatment time, and liquid-to-solid ratio (LSR) on fermentable sugar content (FSC) and total phenolic compounds (TPCs). Following pretreatment, the biomass was hydrolyzed using 1.99% sulfuric acid for 1 min. Optimal pretreatment conditions (350 W, 30 s, LSR 4 w/w) yielded an FSC of 51.14 g/L. Additionally, 230.78 mg/L xylohexaose and 6.47 mg/L xylotetraose were detected. Submerged fermentation of the liquid fraction with A. niger A42 resulted in inulinase and invertase activities of 60.45 U/mL and 21.83 U/mL, respectively. Solid-state fermentation of the pretreated solids produced 37.03 U/mL inulinase and 17.64 U/mL invertase. The integration of microwave-assisted DES pretreatment, dilute acid hydrolysis, and fungal fermentation established a robust strategy for the sequential production of XOS, fermentable sugars, and inulinase from oat husks, supporting their comprehensive utilization within a sustainable biorefinery framework. Full article

Wood and bamboo products with log-term carbon storage, less energy consumption, and CO₂ emission face the challenge of fungal infection. Their antifungal property can be enhanced by Cu-based nanoparticles. Herein, Cu₂O-coated Cu (Cu₂O@Cu) aggregates were grown in situ on the surface of pine wood (PW), beech wood (BW), oak wood (OW), and bamboo via vacuum impregnation. Morphology, crystalline structure, elemental ratio, and chemical state of Cu₂O@Cu and Cu₂O@Cu-loaded specimens were characterized. Uniformly distributed agglomerates composed of Cu₂O@Cu exhibited an average size of 2 μm (Cu₂O@Cu-loaded PW and Cu₂O@Cu-loaded BW) and several hundred nanometers (Cu₂O@Cu-loaded OW and Cu₂O@Cu-loaded bamboo) on the surfaces. A strong mold resistance for Aspergillus niger was achieved after cultivating Cu₂O@Cu-loaded specimens for 28 days. Infection values were grade 0 for Cu₂O@Cu-loaded PW and grade 1 for Cu₂O@Cu-loaded BW, Cu₂O@Cu-loaded OW, and Cu₂O@Cu-loaded bamboo (p < 0.05), which were significantly better than those of pristine specimens (grade 2 for PW and grade 4 for BW, OW and bamboo). A low leaching rate of 5.23–7.81% with three repetitions presented a monotonically positive relation with the loading atomic content of Cu (12.6–27.1 at. %), demonstrating an excellent stability of Cu₂O@Cu-loaded specimens. This study highlighted the potential of Cu-based preservatives in the field of wood and bamboo preservation. Full article

Biotechnological valorization of Flourensia cernua foliage was carried out using fungal solid-state fermentation; several outcomes of this bioprocess were identified which added value to the plant material. F. cernua leaves placed in aluminum trays were inoculated with Aspergillus niger; extracts of this plant were evaluated and the foliage was tested for in vitro digestibility. The solid bioprocess was carried out at 75% humidity for 120 h and after the fermentation, β-glucosidase activity; phenolics and in vitro digestibility were quantified and measured. Two high β-glucosidase production levels were detected at 42 and 84 h with 3192 and 4092 U/L, respectively. Several phenolics of industrial importance were detected with a HPLC-ESI-MS, such as glycosides of luteolin and apigenin. The other outcome was a substantial improvement in anaerobic digestibility. The unfermented sample registered a 30% in vitro degradability, whereas samples subjected to 84 h of fungal fermentation increased degradability by up to 51%. This bioprocess was designed to detect more than one product, which can contribute to an increase in the added value of F. cernua foliage. Full article

Solid-state fermentation (SSF) involves the growth of microorganisms on solid substrates, mimicking natural environments of many species. Due to sustainability concerns, transforming agro-industrial by-products into value-added products through SSF has been increasingly studied. Brewer’s spent grain (BSG), the main by-product of beer production, mostly consists of barley grain husks, making BSG a great support for microorganism cultivation. Although autoclaving remains the standard sterilization and pretreatment method of substrates, electric field technologies and their attendant ohmic heating (OH) have great potential as an alternative technology. In the present work, pretreatment of BSG by OH was explored in SSF with Aspergillus niger to produce commercially valuable enzymes. OH favored the solubilization of phenolic compounds, total protein, and reducing sugars significantly higher than autoclaving. SSF of treated BSG led to the production of lignocellulosic enzymes, with xylanases being the most active, reaching 540 U/g, a 1.5-fold increase in activity compared to autoclaved BSG. Protease activity was also improved 1.6-fold by OH, resulting in 49 U/g. Our findings suggest that OH treatment is an effective alternative to autoclaving and that its integration with SSF is a sustainable strategy to enhance by-product valorization through enzyme production with many industrial applications, according to circular economy guidelines. Full article

The filamentous fungal genus Aspergillus represents an industrially significant group of eukaryotic microorganisms. For nearly a century, it has been widely utilized in the production of diverse high-value products, including organic acids, industrial enzymes, recombinant proteins, and various bioactive natural compounds. With the rapid advancement of synthetic biology, Aspergillus has been extensively exploited as a heterologous chassis for the production of heterologous proteins (e.g., sweet proteins and antibodies) and the synthesis of natural products (e.g., terpenoids and polyketides) due to its distinct advantages, such as superior protein secretion capacity, robust precursor supply, and efficient eukaryotic post-translational modifications. In this review, we provide a comprehensive summary of the advancements in the successful expression of heterologous proteins and the biosynthesis of natural products using Aspergillus platforms (including Aspergillus niger, Aspergillus nidulans, and Aspergillus oryzae) in recent years. Emphasis is placed on the applications of A. oryzae in the heterologous biosynthesis of terpenoids. More importantly, we thoroughly examine the current state of the art in utilizing CRISPR-Cas9 for genetic modifications in A. oryzae and A. niger. In addition, future perspectives on developing Aspergillus expression systems are discussed in this article, along with an exploration of their potential applications in natural product biosynthesis. Full article

Microsporidia MB (MB), a promising biological control agent, suppresses Plasmodium falciparum transmission in Anopheles mosquitoes. This study examined the spatial distribution of MB infection in natural populations of An. gambiae s.l. mosquitoes collected in Nigeria and Niger Republic, and its association with insecticide susceptibility in the mosquitoes. Microsporidia MB has wide geographic distribution across Nigeria and Niger Republic. The overall prevalence of MB in F₀ mosquitoes was 12.25% (95% CI: 7.76–16.75%); 25 mosquitoes out of 204 were positive. Geographic variation was observed, with a higher prevalence (5/15 mosquitoes) in Ebonyi State (33.33%, CI: 9.48–57.19%, Fisher’s exact test, p = 0.008). Infection rates were higher in An. coluzzii mosquitoes (21/133 mosquitoes), estimated at 15.79% (CI: 9.59–21.99%) compared to An. gambiae s.s. mosquitoes (4/71), with approximately 5.63% (CI: 0.27–11.00%, χ² = 4.44; df = 1, p = 0.035). Resistant mosquitoes had a significantly higher prevalence of MB infection than susceptible mosquitos at 28.57% (CI: 16.74–40.40%) with an odds ratio of 3.33 (CI: 1.23–9.03, p = 0.017). These findings suggests that MB can be exploited as an alternative for vector control in Nigeria and Niger, but its possible association with pyrethroid resistance suggests that it should be taken into account as a potential confounder when designing insecticide resistance management strategies. Full article

Urban settings in West Africa are increasingly experiencing extreme weather events, such as heat waves, floods, and windstorms. Climate phenomena exacerbated by global climate change are not unique to this region but reflect a broader trend of worldwide environmental changes. However, how local communities in tropical cities in the global south adapt to these extreme events is not fully understood. Understanding local adaptation strategies is crucial in enhancing our ability to develop context-specific policies that address climate vulnerabilities. This study aimed to analyse the adaptation and mitigation strategies employed by the urban residents of Abuja and Ouagadougou in response to recurrent floods, heat waves, and windstorms. To investigate adaptation and mitigation strategies for climate change in urban areas, this study collected quantitative data from a sample of 840 households in Abuja and 840 households in Ouagadougou. The results revealed that the participants of each city used different strategies to adapt to and mitigate heat waves, floods, and windstorms. However, the level of adoption of these measures differed among the respondents. The findings revealed a low level of adoption of climate change mitigation measures. Context-specific policies must prioritise strengthening local adaptation strategies, addressing socioeconomic disparities, and fostering urban design solutions tailored to each city’s unique environmental and infrastructural challenges. Full article

Creosote bush (Larrea tridentata), a shrub distributed across approximately 19 Mha of arid North American regions, has traditional applications in folk medicine due to the presence of bioactive molecules such as nordihydroguaiaretic acid (NDGA) and ellagic acid (EA). This study investigated the implementation of a solid-state fermentation (SSF) optimization process employing creosote bush leaves as substrate using Aspergillus niger GH1 to improve NDGA and EA extraction. This study was based on previous research by our group that identified key parameters for NDGA production in a related SSF system. Creosote bush is a recognized source of these bioactive compounds, which possess antioxidant and anti-inflammatory properties. Conventional extraction methods often exhibit limitations in efficiency and sustainability. The efficacy of A. niger GH1 in SSF has been previously established with diverse substrates. In this study, A. niger GH1 was employed in an SSF process utilizing creosote bush leaves as a substrate using a Box–Behnken experimental design. The accumulation of NDGA and EA, which were quantified by HPLC-MS, yielded values of 1.20 ± 0.32 mg g⁻¹ for EA and 7.39 ± 0.52 mg g⁻¹ for NDGA. In vitro antioxidant assays (DPPH and ABTS) demonstrated significant antioxidant activity, with inhibition percentages of 55.69% and 84.84%, respectively. These results indicate that A. niger GH1-mediated SSF using Creosote bush leaves is a viable and sustainable strategy for producing these valuable bioactive compounds. Full article

Black beans (Phaseolus vulgaris L.) are one of the most consumed legumes worldwide. Black beans are rich in proteins, vitamins, minerals, and polyphenolic compounds. The present study aims to valorize black beans for the extraction of polyphenolic compounds using solid-state fermentation (SSF) from Aspergillus niger GH1. A physicochemical analysis of black beans was performed. Fermentation kinetics was performed to establish the best accumulation time of condensed polyphenols. A two-level Plackett–Burman experimental design was used to evaluate the culture conditions (temperature, humidity, inoculum, particle size, pH and salt concentration) for the accumulation of condensed polyphenols. The results of the physicochemical analysis showed that black beans can be used as a substrate in the SSF process. In addition, the best time for the accumulation of condensed polyphenols was 48 h. Treatment 5 achieved an accumulation of 21.04 mg/g of condensed polyphenols. While the factors of particle size, humidity, and temperature had a significant effect on the accumulation of condensed polyphenols. It is concluded that the SSF process is an efficient and eco-friendly extraction method for obtaining bioactive molecules with potential applications in the pharmaceutical, food, and cosmetic industries. Full article

Land Use and Land Cover Change (LULCCs) shapes catchment dynamics and is a key driver of hydrological risks, affecting hydrological responses as vegetated land is replaced with urban developments and cultivated land. The resultant hydrological risks are likely to become more critical in the future as the climate changes and becomes increasingly variable. Understanding the effects of LULCC is vital for developing land management strategies and reducing adverse effects on the hydrological cycle and the environment. This study examines LULCC dynamics in the Niger Delta Region (NDR) of Nigeria from 1986 to 2024. A supervised maximum likelihood classification was applied to Landsat 5 TM and 8 OLI images from 1986, 2015, and 2024. Five land use classes were classified: Water bodies, Rainforest, Built-up, Agriculture, and Mangrove. The overall accuracy of the land use classification and Kappa coefficients were 93% and 0.90, 91% and 0.87, 84% and 0.79 for 1986, 2015, and 2024, respectively. Between 1986 and 2024, built-up and agriculture areas substantially increased by about 8229 and 6727 km² (561% and 79%), respectively, with a concomitant decrease in mangrove and vegetation areas of about 14,350 and 10,844 km² (−54% and −42%), respectively. The spatial distribution of changes across the NDR states varied, with Delta, Bayelsa, Cross River, and Rivers States experiencing the highest decrease in rainforest, with losses of 64%, 55, 44%, and 44% (5711 km², 3554 km², 2250 km², and 1297 km²), respectively. The NDR’s mangroves are evidently under serious threat. This has important implications, particularly given the important role played by mangrove forests in regulating hydrological hazards. The dramatic decrease in the NDR mangrove and rainforest could exacerbate climate-related impacts. The study provides quantitative information on LULCC dynamics that could be used to support planning on land management practices in the NDR as well as sustainable development. Full article

Urbanization and population growth in West Africa have significantly altered land use and land cover (LULC), raising environmental concerns. This study examines urban land use patterns in the District Autonome du Grand Lomé (DAGL) and Greater Accra Metropolitan Area (GAMA) from 1986 to 2023 and from 1991 to 2023, respectively, using geospatial techniques and the Google Earth Engine (GEE). Previous research has overlooked the complexity of land use patterns and the directional analysis of urban expansion, which are vital for understanding urbanization drivers. This study addresses these gaps by comparing the two metropolitan areas, revealing a dramatic decline in verdant landscapes, with forested areas in DAGL decreasing from 24% in 1986 to 3% by 2023, and from 34% in 1991 to 2% in GAMA. Grasslands also diminished significantly, while built-up areas expanded from 18% to 62% in DAGL and from 10% to 70% in GAMA. The Urban Expansion Intensity Index (UEII) indicates rapid urban growth, with DAGL at 1.19% and GAMA at 1.88%. Directional analyses reveal that urban expansion predominantly occurs toward the northwest in DAGL and both northeast and northwest in GAMA, highlighting the need for effective urban planning and land management to preserve natural landscapes amidst ongoing urbanization challenges. Full article

Cotton stalks, a major agricultural byproduct, are challenging to decompose naturally; however, they can be transformed into valuable animal feed through microbial fermentation. This study identifies Aspergillus niger HQXY as the most efficient cellulase-producing strain out of six evaluated strains, using it to ferment cotton stalks and significantly degrade cellulose and hemicellulose. By optimizing solid-state fermentation conditions via response surface methodology, the crude fiber content of the cotton stalks was reduced by 34%. A novel sequential co-fermentation approach combining Aspergillus niger with probiotics (Bacillus licheniformis, Candida utilis, and Lactobacillus casei) further enhanced the feed’s nutritional profile. The optimal results were obtained using a 1:1:1 ratio of strains (Aspergillus niger, Bacillus licheniformis, and Lactobacillus casei) at a 8% inoculation rate over 30 days. This co-fermentation strategy lowered the pH and reduced gossypol to 15.5 mg·kg⁻¹. The findings highlight the effectiveness of Aspergillus niger HQXY and probiotics in improving the quality of cotton stalks, by reducing crude fiber and gossypol content, thus offering a promising method for the sustainable utilization of agricultural waste as high-quality animal feed. Full article

The extraction, processing and transport of crude oil in the Niger Delta region of Nigeria has long been associated with collateral environmental damage to the largest mangrove ecosystem in Africa. Oil pollution is impacting not only one of the planet’s most ecologically diverse regions but also the health, livelihoods, and social cohesion of the Delta region inhabitants. Quantifying and directly associating localised oil pollution events to specific petrochemical infrastructure is complicated by the difficulty of monitoring such vast and complex terrain, with documented concerns regarding the thoroughness and impartiality of reported oil pollution events. Earth Observation (EO) offers a means to deliver such a monitoring and assessment capability using Normalised Difference Vegetation Index (NDVI) measurements as a proxy for mangrove biomass health. However, the utility of EO can be impacted by persistent cloud cover in such regions. To overcome such challenges here, we present a workflow that leverages EO-derived high-resolution (10 m) synthetic aperture radar data from the Sentinel-1 satellite constellation combined with machine learning to conduct observations of the spatial land cover changes associated with oil pollution-induced mangrove mortality proximal to pipeline networks in a 9000 km² region of Rivers State located near Port Harcourt. Our analysis identified significant deforestation from 2016–2024, with an estimated mangrove mortality rate of 5644 hectares/year. Using our empirically derived Pipeline Impact Indicator (PII), we mapped the oil pipeline network to 1 km resolution, highlighting specific pipeline locations in need of immediate intervention and restoration, and identified several new pipeline sites showing evidence of significant oil spill damage that have yet to be formally reported. Our findings emphasise the critical need for the continuous and comprehensive monitoring of oil extractive regions using satellite remote sensing to support decision-making and policies to mitigate environmental and societal damage from pipeline oil spills, particularly in ecologically vulnerable regions such as the Niger Delta. Full article