13 research outputs found
Efficient ethanol production from dried oil palm trunk treated by hydrothermolysis and subsequent enzymatic hydrolysis
Biorefining of wheat straw:accounting for the distribution of mineral elements in pretreated biomass by an extended pretreatment–severity equation
BACKGROUND: Mineral elements present in lignocellulosic biomass feedstocks may accumulate in biorefinery process streams and cause technological problems, or alternatively can be reaped for value addition. A better understanding of the distribution of minerals in biomass in response to pretreatment factors is therefore important in relation to development of new biorefinery processes. The objective of the present study was to examine the levels of mineral elements in pretreated wheat straw in response to systematic variations in the hydrothermal pretreatment parameters (pH, temperature, and treatment time), and to assess whether it is possible to model mineral levels in the pretreated fiber fraction. RESULTS: Principal component analysis of the wheat straw biomass constituents, including mineral elements, showed that the recovered levels of wheat straw constituents after different hydrothermal pretreatments could be divided into two groups: 1) Phosphorus, magnesium, potassium, manganese, zinc, and calcium correlated with xylose and arabinose (that is, hemicellulose), and levels of these constituents present in the fiber fraction after pretreatment varied depending on the pretreatment-severity; and 2) Silicon, iron, copper, aluminum correlated with lignin and cellulose levels, but the levels of these constituents showed no severity-dependent trends. For the first group, an expanded pretreatment-severity equation, containing a specific factor for each constituent, accounting for variability due to pretreatment pH, was developed. Using this equation, the mineral levels could be predicted with R(2) > 0.75; for some with R(2) up to 0.96. CONCLUSION: Pretreatment conditions, especially pH, significantly influenced the levels of phosphorus, magnesium, potassium, manganese, zinc, and calcium in the resulting fiber fractions. A new expanded pretreatment-severity equation is proposed to model and predict mineral composition in pretreated wheat straw biomass
Surface properties correlate to the digestibility of hydrothermally pretreated lignocellulosic Poaceae biomass feedstocks
Strategies for Using Pulp and Paper Sludges as Culture Media for Xylanase Production with Bacillus pumilus
Preservation of the articular capsule and short lateral rotator in direct anterior approach to total hip arthroplasty
Steam Explosion: Hydrothermal Pretreatment in the Production of an Adsorbent Material Using Coconut Husk
Comparative life cycle assessment of first- and second-generation ethanol from sugarcane in Brazil
Prokaryote/eukaryote dichotomy and bacteria/archaea/eukarya domains : two inseparable concepts
The various schemes proposed to classify microorganisms in the living world have long been subject of heated debates. The classical dichotomic distinction between Prokaryotae (cells without nucleus) and Eukaryotae (cells with nucleus) functional and phenotypic categories was deeply changed by rRNA gene-based analysis that divided the living world into three phylogenetic domains: the Bacteria, the Archaea (originally Archaebacteria), and the Eukarya. In this chapter, we review the terms of this debate between the prokaryotic/eukaryotic functional and phenotypic dichotomy and the 16S/18S phylogenetic dichotomy that separates prokaryotes into two distinct domains. The specific characteristics that emphasize the organizational and functional complexity of prokaryotes and justify maintaining this terminology are discussed. We conclude that the organizational and functional concept of a prokaryotes/eukaryotes dichotomy can be easily supplemented by the phylogenetic concept Bacteria/Archaea/Eukarya. The two concepts are not irreconcilable but complementary, resulting in a consensual proposal that integrates bothphenotypic and genotypic criteri