Methanesulfonic acid-mediated conversion of microalgae Scenedesmus obliquus biomass into levulinic acid

The main aim of this work was to produce levulinic acid (LA) from sugarcane bagasse (SB) and since there is approximately 3 000 000 tons of bagasse produced per annum by 16 factories that are located on the north coast of Kwa-Zulu Natal, after the extraction of sugar. For this project fructose was firstly used for the production of LA, thereafter SB was used to produce LA. Cellulose was extracted from sugarcane bagasse using two types of pre-treatments namely (i) acid-alkali pre-treatment and (ii) liquid hot water (LHW). In the latter method acid hydrolysis and enzymatic hydrolysis was used to hydrolyse cellulose to glucose. For the acid-alkali pre-treatment work, two types of bagasse was used namely (i) mill-run bagasse and (ii) depithed bagasse and for the LHW a mill-run bagasse (pellets form) was used. In both pre-treatment methods the glucose solution was then acid catalysed by two different acids (i) an environment friendly acid, methanesulfonic acid (MSA) and (ii) sulphuric acid, producing levulinic acid. The results showed that MSA and sulphuric acid produced almost the same yield of LA but, MSA is preferred for the production of LA since it is less toxic and less corrosive than sulphuric acid.

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Catalytic condensation of depithed sugarcane bagasse derived levulinic acid into diphenolic acid

BioResources ◽

10.15376/biores.16.2.2235-2248 ◽

2021 ◽

Vol 16 (2) ◽

pp. 2235-2248

Author(s):

Lethiwe Debra Mthembu ◽

David Lokhat ◽

Nirmala Deenadayalu

Keyword(s):

Sulfuric Acid ◽

Sugarcane Bagasse ◽

Levulinic Acid ◽

Methanesulfonic Acid ◽

Environmentally Benign ◽

Catalyst Loading ◽

Optimum Conditions ◽

Reaction Parameters ◽

Reaction Conditions ◽

Catalytic Condensation

Levulinic acid (LA) is a platform chemical that can be produced from biomass. Diphenolic acid (DPA) is a derivative of LA with the potential to replace bisphenol A, a plasticizer. To determine the optimum conditions for DPA production, commercial LA was used with a mild environmentally benign acid, namely, methanesulfonic acid (MsOH). The optimized reaction parameters were time (6 h), temperature (75 °C), and catalyst loading (5.5 g), yielding 65.8% DPA at 90% LA conversion. The response surface methodology (RSM) study indicated that the temperature had the most significant effect on DPA yield, followed by time and catalyst loading. The analysis of variance (ANOVA) revealed that the model was able to satisfactorily predict the DPA yield. To determine the effect of catalyst on DPA production from commercial LA, ionic liquids (ILs), MsOH, and sulfuric acid were used. IL catalysts produced 59 to 68% of DPA, MsOH produced 65.6% of DPA, and sulfuric acid produced the maximum DPA of 74%. The study of LA: phenol ratio revealed that more reactants (2:5) yielded the most DPA (86.35%). The optimized reaction conditions were then used to produce DPA from LA derived from depithed sugarcane bagasse (DSB), which yielded 64.5% of DPA.

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Optimization of the levulinic acid production from the red macroalga, Gracilaria verrucosa using methanesulfonic acid

Algal Research ◽

10.1016/j.algal.2018.02.004 ◽

2018 ◽

Vol 31 ◽

pp. 116-121 ◽

Cited By ~ 11

Author(s):

Mi-Ra Park ◽

Sung-Koo Kim ◽

Gwi-Taek Jeong

Keyword(s):

Acid Production ◽

Levulinic Acid ◽

Methanesulfonic Acid ◽

Gracilaria Verrucosa ◽

Red Macroalga

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RESPONSES OF GLUTATHIONE CYCLE ENZYMES AND GLUTATHIONE METABOLISM TO 1-HEXYL-3-METHYLIMIDAZOLIUM STRESS IN SCENEDESMUS OBLIQUUS

Acta Hydrobiologica Sinica ◽

10.3724/sp.j.1035.2009.40696 ◽

2009 ◽

Vol 33 (4) ◽

pp. 696-701

Author(s):

Jian-Min MA ◽

Lin-Lin CAI ◽

Ling-Wei HU ◽

Tong-Xia JIN ◽

Xiao-Yu LI ◽

...

Keyword(s):

Scenedesmus Obliquus ◽

Glutathione Metabolism ◽

Glutathione Cycle

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UV ability to inactivate microorganisms combined with factors affecting radiation

Water Science & Technology ◽

10.2166/wst.1997.0718 ◽

1997 ◽

Vol 35 (11-12) ◽

pp. 107-112 ◽

Cited By ~ 7

Author(s):

A. M. Shaban ◽

G. E. El-Taweel ◽

G. H. Ali

Keyword(s):

Microbial Communities ◽

Uv Radiation ◽

Contact Time ◽

Tap Water ◽

Scenedesmus Obliquus ◽

Morphological Characters ◽

The Other ◽

Bacterial Cells ◽

Dark Repair ◽

Nile Water

In the present study, the effect of UV radiation on the inactivation of a range of microorganisms was studied. Each organism was seeded into sterile tap water and exposed to UV in batch experiments with changing turbidities. In addition, the effect of UV on microbial communities in river Nile water was examined. It was found that 1min contact time (0.5L/min flow rate) was effective against vegetative cells levels almost reaching zero (except with Staphylococcus aureus). On the other hand, spore-forming bacteria, Candida albicans and coliphage were more resistant to UV. This contact time caused coenobia cells in single form with Scenedesmus obliquus while for Microcystis aeruginosa colonies broke into smaller groups. Exposure of Nile water microbial communities to UV showed that yeasts and Aeromonas survived better than the other organisms while in the phytoplankton partial fragmentation occurred in some algal groups. The protective effect of turbidity differed between organisms, with increased contact time under conditions of stable turbidity having no effect on the organisms. At 20 NTU the UV radiation had no effect on the morphological characters of algal cells. In reactivation experiments, it is clear that photoreactivation, and not dark repair, takes place with bacterial cells. Only coliphage had no photoreactivation and dark repair responses although with coliphage and host, both reactivation processes worked well. Moreover, the irradiated algae regained their normal shape after 3 days in suitable media and enough light.

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