Pre-treatment optimization of Scenedesmus obliquus microalga for bioethanol production

Miranda, J. R.; Passarinho, Paula C.; Gouveia, Luísa

doi:10.1016/j.biortech.2011.10.059

Cited by 249 publications

(118 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In acid and alkaline methods, H 2 SO 4 is the most applied acid whereas NaOH is the most studied base. Treatments have been shown to be effective as pretreatment for fermentation and extraction of intercellular compounds such as lipids and pigments (Mendes-Pinto et al, 2001;Miranda et al, 2012;Nguyen et al, 2009). The reaction can be performed at ambient or elevated pressure, and temperatures above 100°C enhance reaction rates.…”

Section: (Bio)chemical Methods For Cell Wall Disruptionmentioning

confidence: 99%

Cell disruption technologies

Dhondt

Martín-Juárez

Bolado

et al. 2017

Microalgae-Based Biofuels and Bioproducts

View full text Add to dashboard Cite

IntroductionAlgal cell walls separate the inside cell content from the environment to protect the cell against desiccation, pathogens, and predators while still allowing exchange of compounds. Toward application of algae biomass as a sustainable resource, disruption of this cell wall (¼cell disruption) is an essential pretreatment step to maximize product recovery in downstream processes of the algae biorefinery. Also for direct use of algae in feed or food, cell rupture is required to increase the bioavailability of algae constituents. Depending on the cell wall structure, the size, and the shape of algae, cell disruption can be challenging. A variety of cell disruption methods is currently available, and new approaches are being elaborated in parallel. Since downstream processing is responsible for a large part of the operational costs in the whole production chain, cell disruption technologies should be low cost and energy efficient and result preferably in high product quality. This chapter provides information on cell wall types and gives an overview of physical-mechanical and (bio-)chemical cell disruption technologies with attention to development stage, energy efficiency, product quality, costs, emerging approaches, and applicability on large scale. Cell wall types in various groups of microalgae and cyanobacteriaThe cell wall composition and architecture of algae and cyanobacteria are highly variable ranging from tiny membranes to multilayered complex structures. Despite the importance of algal cell wall properties in biotechnology, little structural information is available for most species (Scholz et al., 2014). Based on the complexity of surface structures, four cell types could be distinguished (Barsanti and Gualtieri, 2006;Lee, 2008) (Fig. 6.1). A simple cell membrane (Fig. 6.1, Type 1) is present in short-lived stages (e.g., gametes), chrysophytes, raphidophytes, green algae Dunaliella, and haptophytes Isochrysis. It consists of a lipid bilayer with integrated and peripheral proteins. Sometimes a cap of glycolipids and glycoproteins envelops the outer surface of cell membrane. Cell membranes with additional extracellular material are known in cyanobacteria and many groups of algae, including palmelloid phases. It is the most diverse cell wall type that includes various membrane-associated structures (cell wall, Microalgae-Based Biofuels and Bioproducts. http://dx

show abstract

Section: (Bio)chemical Methods For Cell Wall Disruptionmentioning

confidence: 99%

Cell disruption technologies

Dhondt

Martín-Juárez

Bolado

et al. 2017

Microalgae-Based Biofuels and Bioproducts

View full text Add to dashboard Cite

show abstract

“…The yield of ethanol from the fermentation of microalgal biomass has been found to be up to 38 % of the dry microalgal biomass (Harun et al 2010). An advantage of fermentation of microalgae may be that wet biomass could be used, but a recent study found that the sugar released from fermentation of dried biomass was 55 % higher than that from wet microalgal biomass (Miranda et al 2012). If the microalgal biomass needs to be dried prior to conversation to fermentable sugars for bioethanol production it is likely that bioethanol production will not be energy efficient or economic.…”

Section: Microalgal Bioethanolmentioning

confidence: 99%

“…A sugar extraction efficiency of 96 % has been achieved by acid hydrolysis of dried Scenedesmus biomass (Miranda et al 2012). …”

Section: Microalgal Bioethanolmentioning

confidence: 99%

Methods of energy extraction from microalgal biomass: a review

Milledge

Heaven

2014

Rev Environ Sci Biotechnol

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 99%

“…Carbohydrates are mainly present in microalgae cell wall as cellulose and hemicellulose, and/or inside the cell as starch. Cell walls are mainly composed of biopolymers such as sporopollenin or algaenan, which 4 confer the cell a high rigidity and resistance to chemical attack (González-Hernández et al., 2012) and are characteristic of microalgae strains like Scenedesmus (Miranda et al, 2012).In order to make available the valuable compounds present inside microalgae cells, pretreatments are often needed in order to disrupt cell walls. Microalgae pretreatment allows for an efficient release of the carbohydrate content, enhancing saccharification and sugars bioavailability to maximize biofuels production (Hernández et al, 2015).…”

mentioning

confidence: 99%

Saccharification of microalgae biomass obtained from wastewater treatment by enzymatic hydrolysis. Effect of alkaline-peroxide pretreatment

Juarez

Lorenzo-Hernando

Muñoz

et al. 2016

Bioresource Technology

View full text Add to dashboard Cite

An enzymatic method for the carbohydrate hydrolysis of different microalgae biomass cultivated in domestic (DWB) † and pig manure (PMWB) wastewaters, at different storage conditions (fresh, freeze-dried and reconstituted), was evaluated. The DWB provided sugars yields between 40 and 63%, although low xylose yields (< 23.5%).Approximately 2% of this biomass was converted to byproducts as succinic, acetic and formic acids. For PMWB, a high fraction of the sugars (up to 87%) was extracted, but mainly converted into acetic, butyric and formic acids, which was attributed to the bacterial action. In addition, the performance of an alkaline-peroxide pretreatment, conducted for 1 hour, 50ºC and H 2 O 2 concentrations from 1 to 7.5% (w/w), was essayed. The hydrolysis of pretreated microalgae supported a wide range of sugars extraction for DWB (55-90%), and 100% for PMWB. Nevertheless, a large fraction of these sugars (~30% for DWB and 100% for PMWB) was transformed to byproducts. HighlightsTested biomass showed different behaviours depending on the algae/bacteria ratio.Enzymatic hydrolysis of DWB yielded high glucose and low xylose extraction.Sugars from PMWB were completely released by enzymatic hydrolysis but oxidized.Acetic, formic and succinic acids were the main byproducts from released sugars.Pretreatment enhanced enzymatic hydrolysis performance for almost all biomass tested. † Abbreviations: DWB, domestic wastewater biomass; PMWB, pig manure microalgae biomass; HRT, hydraulic retention time; SRT, sludge retention time; CO 2 , carbon dioxide; CH 4 , methane. Keywords: Enzymatic hydrolysis; Glucose; Xylose; Wastewater; Alkaline-peroxide pretreatment IntroductionWorld human population and industrial activity have exponentially increased during last decades, with a concomitant raise in global energy demand. This growth has been traditionally based on fossil fuels, whose side effects have turned this dependence environmentally unsustainable (Chisti, 2007). New renewable fuel sources and biorefinery approaches for designing cost-effective and "green" processes are expected to create more efficient and sustainable economies (Daroch et al., 2013). During the past decade, microalgae have experimented a continuous and positive development due to their wide range of practical applications: wastewater treatment, nitrogen and phosphorous recovery, biogas upgrading, production of biofuels, biofertilizers, animal and fish feed, etc. Despite Oswald and co-workers were pioneers in introducing the microalgae biorefinery concept in the 60's, the combination and optimization of processes for the valorisation of microalgae biomass obtained from wastewaters treatment remains a challenge nowadays (Acién et al, 2014).Microalgae biomass is mainly composed of proteins (6% -52%), lipids (5% -23%) and carbohydrates (7% -23%) (Tijani et al., 2015). This content may vary within microalgae strains and is highly dependent on cultivation conditions, especially under nutrients-deprivation scenarios. Among them, carbohydrates are one of th...

show abstract

Pre-treatment optimization of Scenedesmus obliquus microalga for bioethanol production

Cited by 249 publications

References 30 publications

Cell disruption technologies

Cell disruption technologies

Methods of energy extraction from microalgal biomass: a review

Saccharification of microalgae biomass obtained from wastewater treatment by enzymatic hydrolysis. Effect of alkaline-peroxide pretreatment

Contact Info

Product

Resources

About