Investigation of enzyme-assisted methods combined with ultrasonication under a controlled alkali pretreatment for agar extraction from Gelidium sesquipedale

Biorefinery, which utilizes carbon-neutral biomass as a resource, is attracting attention as a significant alternative in a modern society confronted with climate change. In this study, spent coffee grounds (SCGs) were used as the feedstock for lactic acid fermentation. In order to improve sugar conversion, alkali pretreatment was optimized by a statistical method, namely response surface methodology (RSM). The optimum conditions for the alkali pretreatment of SCGs were determined as follows: 75 °C, 3% potassium hydroxide (KOH) and a time of 2.8 h. The optimum conditions for enzymatic hydrolysis of pretreated SCGs were determined as follows: enzyme complex loading of 30-unit cellulase, 15-unit cellobiase and 50-unit mannanase per g biomass and a reaction time of 96 h. SCG hydrolysates were used as the carbon source for Lactobacillus cultivation, and the conversions of lactic acid by L. brevis ATCC 8287 and L. parabuchneri ATCC 49374 were 40.1% and 55.8%, respectively. Finally, the maximum lactic acid production by L. parabuchneri ATCC 49374 was estimated to be 101.2 g based on 1000 g of SCGs through the optimization of alkali pretreatment and enzymatic hydrolysis.

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Structural modification of pine and poplar wood by alkali pretreatment to improve ethanol production

Industrial Crops and Products ◽

10.1016/j.indcrop.2020.112506 ◽

2020 ◽

Vol 152 ◽

pp. 112506 ◽

Cited By ~ 2

Author(s):

Mohammad Saber Bay ◽

Keikhosro Karimi ◽

Mohsen Nasr Esfahany ◽

Rajeev Kumar

Keyword(s):

Ethanol Production ◽

Structural Modification ◽

Poplar Wood ◽

Alkali Pretreatment

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Protein and amino acids analysis during alimentary-agar extraction from Gelidium sesquipedale

Hydrobiologia ◽

10.1007/bf00046176 ◽

1987 ◽

Vol 151-152 (1) ◽

pp. 513-522 ◽

Cited By ~ 2

Author(s):

A. Faraj ◽

T. Lebbar ◽

G. Debry ◽

L. Najim

Keyword(s):

Amino Acids ◽

Gelidium Sesquipedale

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Improvement of organoleptic quality of retted cassava products by alkali pretreatment of roots and addition of sodium nitrate during retting

International Journal of Food Microbiology ◽

10.1016/s0168-1605(03)00113-2 ◽

2003 ◽

Vol 89 (1) ◽

pp. 85-90 ◽

Cited By ~ 1

Author(s):

Frank C Ogbo

Keyword(s):

Sodium Nitrate ◽

Alkali Pretreatment ◽

Organoleptic Quality

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Alkali treatment of fungal pretreated wheat straw for bioethanol production

Bioethanol ◽

10.1515/bioeth-2015-0004 ◽

2016 ◽

Vol 2 (1) ◽

Cited By ~ 4

Author(s):

María García-Torreiro ◽

Miguel Álvarez Pallín ◽

María López-Abelairas ◽

Thelmo A. Lu-Chau ◽

Juan M. Lema

Keyword(s):

Wheat Straw ◽

Alkali Treatment ◽

Alkaline Treatment ◽

White Rot ◽

White Rot Fungus ◽

Process Conditions ◽

Alkali Pretreatment ◽

Irpex Lacteus ◽

C 30 ◽

Pretreated Wheat Straw

AbstractBioconversion of lignocellulosic materials into ethanol requires an intermediate pretreatment step for conditioning biomass. Sugar yields from wheat straw were previously improved by the addition of a mild alkali pretreatment step before bioconversion by the white-rot fungus Irpex lacteus. In this work, an alternative alkaline treatment, which significantly reduces water consumption, was implemented and optimized. Sugar recovery increased 117% with respect to the previously developed alkaline wash process at optimal process conditions (30°C, 30 minutes and 35.7% (w/w) of NaOH). In order to further reduce operational costs, a system for alkali recycling was implemented. This resulted in the treatment of 150% more wheat straw using the same amount of NaOH. Finally, enzymatic hydrolysis was optimized and resulted in a reduction of enzyme dose of 33%.

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