Biofuel production potentialityof indigenous algal species around Bayero University Kano, Nigeria.

Extraction of Intracellular Lipid as Potential Biofuel Source From Algal Biomass

Fossil fuels occuring as ancient algal deposit is the major source of energy for our engines today. It is a limited non-renewable resource that will eventually run out. It is in this regards that this work was carried out to determine and extract intracellular lipid in algal biomass for subsequent use as biofuel. Four average sized ponds within Federal University Dutse Campus, Nigeria (11.00̊ N to 13.00̊ N and longitude 8.00̊ E to 10.15̊ E and altitude 465.5m). were randomly selected and 20ml pond water were collected from top, middle and bottom of each pond. 60ml pond water was taken to laboratory and were processed by preparing the media. 3ml NPK gel fertilizer was mixed with distilled water and autoclave at 121°C for 15 min. Bold's Basal Medium (BBM) consisting stock solution and BBM consisting of trace elements were separately mixed with distilled water. 10 ml of the stock solution and 1.0 ml of the trace elements were autoclave at 121°C for 15 min. The media (BBM and fertilizer) were cooled at room temperature, antibiotics (penicillin G, di-hydro-streptomycin sulfate and gentamycin sulfate) were added and pH adjusted to 7.5 and the media were kept ready for used. Isolations of species were carried out by serial dilution using BBM and under microscope sterile syringe and needles were used to isolate target cells. Four different algal species; Euglena, Spirogyra, Selenastrum and Chlorella were isolated and identified. Culturing was carried out by transferring isolate into 50 ml growth chamber containing BBM and NPK fertilizer media separately and cultured using sunlight for 10 days under controlled pH. Two successfully grown species; Spirogyra and Selenastrum were transferred aseptically into four constructed photobioreactors containing 400 ml liquid media; two containing BBM and the other fertilizer media. Nile Red was used to stain the algal biomass, observed under microscope and photographed. Residual salts were removed and mass dried using thermostatic drying oven and subsequently grinded. Growths were determined through dry weight determination and growth percentage was obtained. The dried algal biomass was extracted and evaporated and extracts were heated using vacuum rotary evaporator to separate the solvent from the extracts. Transesterification was carried out. Phase separation was carried out along with purification in which soap and other impurities were removed and resulting solution remained flammable biodiesel. While Euglena and Chlorella failed to grow in the initial media, both Spirogyra, and Selenastrum produced significant amount of biodiesel with Selenastrum species producing higher quantity than that obtained from Spirogyra, hence a potential source of the fuel.

Techno-Economic Analysis of Biodiesel Production from Microalgae

The increasing global energy demand and the urgent necessity to mitigate greenhouse gas emissions have driven the exploration of renewable energy alternatives to fossil-based fuels, such as biofuels derived from sustainable biological sources. Among various potential feedstocks, microalgae have gained considerable attention due to their high lipid productivity, rapid growth rate, and ability to utilize CO₂ efficiency through photosynthesis. This study presents the design and techno-economic evaluation of a biodiesel production plant utilizing Chlorella vulgaris microalgae as the primary feedstock. The cultivation process employs a Flat Plate Photobioreactor (FPPBR) system to enhance biomass productivity under controlled light and nutrient conditions. The production process adopts the Lurgi technology, beginning with the extraction of microalgae oil using n-hexane solvent, which is subsequently converted into biodiesel through esterification and transesterification reactions catalyzed by H₂SO₄ and NaOH, respectively. The designed plant capacity is 100,000 kL of biodiesel per year. Bontang, East Kalimantan, is selected as the plant site considering key factors such as raw material availability, access to utilities, land suitability, and transportation infrastructure. The plant consists of two main stages: microalgae oil production and biodiesel synthesis, with a total construction period of two years and an operational lifespan of 15 years. Economic feasibility analysis indicates an Internal Rate of Return (IRR) of 12.91%, a Net Present Value (NPV) of IDR 2,296,063,930,982, and a payback period of 13 years, confirming the financial viability of the project. These results demonstrate that biodiesel production from Chlorella vulgaris microalgae is both technically feasible and economically sustainable, providing a practical and scalable pathway to support Indonesia’s transition toward renewable and low-carbon energy systems.

Marine microalgae as potential source for sustainable aquafeeds: A scientometric perspective on stewarding aquaculture sustainability

Exploring Prosopis juliflora as a Sustainable Biomass Source for Bioethanol: A Review of Processing Methods and Production Potential

As the 20th century progressed, the accelerated growth of industry and the consistent increase in population size in major urban areas contributed to an escalating release of greenhouse gases, including carbon dioxide (CO2). Fuels derived from renewable materials, such as plant biomass, offer an alternative to traditional fuels, providing a more environmentally friendly energy source. A highly relevant alternative would be to align the development of sustainable technologies with the bioprocessing of biomass waste from non-food sources. The tree Prosopis juliflora (P. juliflora) is a promising candidate due to its accessibility and energetic properties. The success of P. juliflora biofuel hinges on pretreatment techniques that maximize enzymatic accessibility to cellulose. This study systematically reviews the extant research on P. juliflora as bioethanol feedstock, with a focus on identifying which plant parts are used, the treatments applied to these parts, and the methods employed for biomass breakdown. The research methodology entailed a bibliometric analysis, which was conducted using the Web of Science database between July 25, 2025, and August 5, 2025. The Vosviewer® software was utilized for the analysis of keyword co-occurrence and author co-citation. The search yielded 29 publications and 32 keywords, with a minimum of three occurrences in the analyzed articles. Of these, 20 publications met the study's scope. The findings of the study demonstrate that chemical pretreatment provides the optimal balance between delignification and cellulose preservation. Acid degradation is still preferred over enzymatic hydrolysis, as it is the approach used in most of the studies that were analyzed. While there are studies that have applied P. juliflora in the production of bioethanol using these strategies, the development of more sustainable research and methodologies is still necessary to obtain biofuel in an effective and ecological way.

Local Plastic-Eating Bacteria: The Key to Bioremediation in Indonesian Coastal Waters

Marine plastic pollution is a critical environmental problem in Indonesian coastal waters, where inadequate waste management and high population density contribute substantially to plastic leakage into the marine environment. Indigenous plastic-degrading bacteria offer a potentially low-cost bioremediation strategy, yet locally isolated strains remain poorly characterized. This study aimed to isolate, screen, and molecularly identify indigenous bacteria capable of degrading polyethylene terephthalate (PET) and low-density polyethylene (LDPE) from seawater, sediment, and plastic-debris samples collected at three stations in Bungus Bay, Padang City, West Sumatra. From 42 morphologically distinct colonies, five isolates with the largest clear zones were selected and identified through 16S rRNA gene sequencing as strains related to Bacillus cereus, Pseudomonas aeruginosa, Rhodococcus ruber, Achromobacter xylosoxidans, and Bacillus subtilis. Quantitative degradation assays conducted in triplicate over 90 days showed that a three-isolate consortium achieved the highest weight loss of PET (16.3%) and LDPE (11.2%), significantly exceeding single-isolate treatments and abiotic controls (ANOVA, Duncan’s test, p < 0.05). FTIR analysis confirmed polymer oxidation, with carbonyl indices increasing from 0.18 to 0.34 for PET and from 0.05 to 0.21 for LDPE. These findings demonstrate considerable biodegradation potential under laboratory conditions, although field validation is required before in-situ application for marine bioremediation purposes.

Pan-life-carpet concept: Integrating waste valorization and biocrust engineering

Land degradation in arid and semi-arid regions poses a major global threat to ecological stability, food security, and socio-economic resilience. Cyanobacteria-dominated biological soil crusts (biocrusts) play a critical role in soil stabilization and nutrient enrichment, but their early establishment and persistence are frequently limited by severe climatic conditions. This study combines cyanobacterial inoculation (Tolypothrix sp.) with bio-based polysaccharide matrices derived from agro-industrial and marine waste to accelerate biocrust development on loess sediment. Alginate (29.34% yield) and fucoidan (5.18% yield) were successfully isolated from the brown seaweed Laminaria digitata, while native cellulose (30.58% yield) was extracted from plum shells (Prunus domestica). Structural integrity was confirmed via FTIR spectroscopy, followed by an evaluation of their water-holding capacity (WHC) and water swelling capacity (WSC). Alginate exhibited superior hydrocolloid properties, achieving the highest WHC (0.8 g/g) and WSC (2.1 mL/g). During a 30-day laboratory cultivation, the addition of all isolated polysaccharides significantly enhanced biological crust development and biomass accumulation compared to the cyanobacteria-only treatment. The most pronounced stimulatory effect was achieved with 0.3% (m/v) alginate, which induced a ninefold increase in chlorophyll a content (352.46 μg/g) compared to the cyanobacteria control (38.33 μg/g). Fucoidan and cellulose also promoted biocrust growth, yielding significantly higher chlorophyll a value (94.82 μg/g and 77.90 μg/g, respectively) than the polysaccharide-free control. These findings validate the Pan-Life-Carpet framework, demonstrating that valorizing renewable biomass waste into eco-friendly support matrices provides a highly effective, cost-efficient, and scalable strategy for accelerated dryland restoration and soil erosion control.