Enhancement of bioethanol production from Ulva fasciata by biological and chemical saccharification

Simultaneous production of biofuel, and removal of heavy metals using marine alga Turbinaria turbinata as a feedstock in NEOM Region, Tabuk

Depletion of fossil fuel and pollution by heavy metals are two major global issues. The cell wall of algae consists of polymers of polysaccharides such as cellulose, hemicellulose, alginate, starch, and many others that are readily hydrolyzed to monosaccharides and hence are amenable to fermentation into bioethanol. Moreover, algae contain lipids that may undergo trans-esterification to biodiesel, and can be absorbed by heavy metals. In this study, extraction of lipids from Turbinaria turbinata (common brown alga) from the beach of Sharma, NEOM, Tabuk, Saudi Arabia by different solvents hexane, methanol, and hexane: methanol (1:1), and trans-esterification was performed to obtain biodiesel and investigated by GC.MS. The alga residue after fats extractions by different solvents was used in bioremediation synthetic wastewater containing 50 ppm of As-3, Co+2, Cu+2, Fe+2, Mn+2, and Zn+2. The residue of defatted alga was hydrolyzed by 2% H2SO4 and then fermented to obtain bioethanol. The combination of hexane: methanol (1:1) gave the greatest amount of petroleum hydrocarbons, which contain Tetradecane, 5-methyl, Octacosane, Pentatriacontane, and a small amount of Cyclotrisiloxane, Hexamethyl. The most effective removal % was obtained with alga residue defatted by hexane: methanol (1:1), and methanol, 100% removal of As-3, 83% Co+2, 95% Cu+2, 97.25% Fe+2, Mn+2 79.69%, Zn+2 90.15% with 2 g alga /L at 3 hours. The lowest value of sugar was obtained with hexane: methanol residue but gave the highest bioethanol efficiency. Thus, it is possible to use Turbinaria turbinata, or brown alga as a feedstock to produce bio-diesel, and bioethanol, and to remove heavy metals from wastewater, which may have a great economic and environmental significance.

Medical prospects of cryptosporidiosis in vivo control using biofabricated nanoparticles loaded with Cinnamomum camphora extracts by Ulva fasciata

Background and Aim

Global efforts are continuing to develop preparations against cryptosporidiosis. This study aimed to investigate the efficacy of biosynthesized Ulva fasciata loading Cinnamomum camphora oil extract on new zinc oxide nanoparticles (ZnONPs shorten to ZnNPs) and silver nanoparticles (AgNPs) as alternative treatments for Cryptosporidium parvum experimental infection in rats.

Materials and Methods

Oil extract was characterized by gas chromatography-mass spectrometry, loaded by U. fasciata on ionic-based ZnO and NPs, and then characterized by transmission electron microscopy, scanning electron microscopy, and X-ray diffraction. Biosafety and toxicity were investigated by skin tests. A total of 105 C. parvum oocysts/rat were used (n = 81, 2-3 W, 80-120 g, 9 male rats/group). Oocysts shedding was counted for 21 d. Doses of each preparation in addition to reference drug were administered daily for 7 d, starting on post-infection (PI) day (3). Nitazoxanide (100 mg) was used as the reference drug. After 3 weeks, the rats were sacrificed for postmortem examination and histopathological examination. Two blood samples/rat/group were collected on the 21st day. Ethylenediaminetetraacetic acid blood samples were also used for analysis of biochemistry, hematology, immunology, micronucleus prevalence, and chromosomal abnormalities.

Results

C. camphora leaves yielded 28.5 ± 0.3 g/kg oil and 20 phycocompounds were identified. Spherical and rod-shaped particles were detected at 10.47-30.98 nm and 18.83-38.39 nm, respectively. ZnNPs showed the earliest anti-cryptosporidiosis effect during 7-17 d PI. Other hematological, biochemical, immunological, histological, and genotoxicity parameters were significantly fruitful; hence, normalized pathological changes induced by infestation were observed in the NPs treatments groups against the infestation-free and Nitazoxanide treated group.

Conclusion

C. camphora, U. fasciata, ZnNPs, and AgNPs have refluxed the pathological effects of infection as well as positively improved host physiological condition by its anticryptosporidial immunostimulant regenerative effects with sufficient ecofriendly properties to be proposed as an alternative to traditional drugs, especially in individuals with medical reactions against chemical commercial drugs.

Advancement of biorefinery-derived platform chemicals from macroalgae: a perspective for bioethanol and lactic acid

The extensive growth of energy and plastic demand has raised concerns over the depletion of fossil fuels. Moreover, the environmental conundrums worldwide integrated with global warming and improper plastic waste management have led to the development of sustainable and environmentally friendly biofuel (bioethanol) and biopolymer (lactic acid, LA) derived from biomass for fossil fuels replacement and biodegradable plastic production, respectively. However, the high production cost of bioethanol and LA had limited its industrial-scale production. This paper has comprehensively reviewed the potential and development of third-generation feedstock for bioethanol and LA production, including significant technological barriers to be overcome for potential commercialization purposes. Then, an insight into the state-of-the-art hydrolysis and fermentation technologies using macroalgae as feedstock is also deliberated in detail. Lastly, the sustainability aspect and perspective of macroalgae biomass are evaluated economically and environmentally using a developed cascading system associated with techno-economic analysis and life cycle assessment, which represent the highlights of this review paper. Furthermore, this review provides a conceivable picture of macroalgae-based bioethanol and lactic acid biorefinery and future research directions that can be served as an important guideline for scientists, policymakers, and industrial players.

Graphical abstract

Acidolysis as a biorefinery approach to producing advanced bioenergy from macroalgal biomass: A state-of-the-art review

Facing fossil fuels consumption and its accompanying environmental pollution, macroalgae, as a major part of the third-generation (3G) biomass, has great potential for bioenergy development due to its species-abundant, renewable and carbohydrate-rich properties. Diluted acid treatment is one of the most effective approaches to releasing fermentable sugars from macroalgal biomass in a short period, but the optimal conditions need to be explored to maximize the hydrolytic yield for the subsequent microbial conversion. Therefore, this review aims to summarize the latest advances in various acids and other auxiliary methods adopted to increase the hydrolytic efficiency of macroalgae. Following an overview of the strategies of different algal types, methods involved in the bioconversion of biofuels and microbial fuel cells (MFC) from algal hydrolysates are also described. For the 3G biorefinery development, the review further discusses key challenges and trends for future utilizing marine biomass to achieve the large-scale industrial production.

Batch bioethanol production via the biological and chemical saccharification of some Egyptian marine macroalgae

AIMS

Marine seaweeds (macroalgae) cause an eutrophication problem and affects the touristic activities. The success of the production of the third-generation bioethanol from marine macroalgae depends mainly on the development of an ecofriendly and eco-feasible pretreatment (i.e. hydrolysis) technique, a highly effective saccharification step and finally an efficient bioethanol fermentation step. Therefore, this study aimed to investigate the potentiality of different marine macroalgal strains, collected from Egyptian coasts, for bioethanol production via different saccharification processes.

METHODS AND RESULTS

Different marine macroalgal strains, red Jania rubens, green Ulva lactuca and brown Sargassum latifolium, have been collected from Egyptian Mediterranean and Red Sea shores. Different hydrolysis processes were evaluated to maximize the extraction of fermentable sugars; thermochemical hydrolysis with diluted acids (HCl and H₂ SO₄ ) and base (NaOH), hydrothermal hydrolysis followed by saccharification with different fungal strains and finally, thermochemical hydrolysis with diluted HCl, followed by fungal saccharification. The hydrothermal hydrolysis of S. latifolium followed by biological saccharification using Trichoderma asperellum RM1 produced maximum total sugars of 510 mg g^-1 macroalgal biomass. The integration of the hydrothermal and fungal hydrolyses of the macroalgal biomass with a separate batch fermentation of the produced sugars using two Saccharomyces cerevisiae strains, produced approximately 0·29 g bioethanol g^-1 total reducing sugars. A simulated regression modelling for the batch bioethanol fermentation was also performed.

CONCLUSIONS

This study supported the possibility of using seaweeds as a renewable source of bioethanol throughout a suggested integration of macroalgal biomass hydrothermal and fungal hydrolyses with a separate batch bioethanol fermentation process of the produced sugars.

SIGNIFICANCE AND IMPACT OF THE STUDY

The usage of marine macroalgae (i.e. seaweeds) as feedstock for bioethanol; an alternative and/or complimentary to petro-fuel, would act as triple fact solution; bioremediation process for ecosystem, renewable energy source and economy savings.