alexa The roles of xylan and lignin in oxalic acid pretreated corncob during separate enzymatic hydrolysis and ethanol fermentation.
Environmental Sciences

Environmental Sciences

Journal of Bioremediation & Biodegradation

Author(s): Lee JW, Rodrigues RC, Kim HJ, Choi IG, Jeffries TW

Abstract Share this page

Abstract High yields of hemicellulosic and cellulosic sugars are critical in obtaining economical conversion of agricultural residues to ethanol. To optimize pretreatment conditions, we evaluated oxalic acid loading rates, treatment temperatures and times in a 2(3) full factorial design. Response-surface analysis revealed an optimal oxalic acid pretreatment condition to release sugar from the cob of Zea mays L. ssp. and for Pichia stipitis CBS 6054. To ferment the residual cellulosic sugars to ethanol following enzymatic hydrolysis, highest saccharification and fermentation yields were obtained following pretreatment at 180 degrees C for 50 min with 0.024 g oxalic acid/g substrate. Under these conditions, only 7.5\% hemicellulose remained in the pretreated substrate. The rate of cellulose degradation was significantly less than that of hemicellulose and its hydrolysis was not as extensive. Subsequent enzymatic saccharification of the residual cellulose was strongly affected by the pretreatment condition with cellulose hydrolysis ranging between 26.0\% and 76.2\%. The residual xylan/lignin ratio ranged from 0.31 to 1.85 depending on the pretreatment condition. Fermentable sugar and ethanol were maximal at the lowest ratio of xylan/lignin and at high glucan contents. The model predicts optimal condition of oxalic acid pretreatment at 168 degrees C, 74 min and 0.027 g/g of oxalic acid. From these findings, we surmised that low residual xylan was critical in obtaining maximal glucose yields from saccharification. (c) 2010 Elsevier Ltd. All rights reserved. This article was published in Bioresour Technol and referenced in Journal of Bioremediation & Biodegradation

Relevant Expert PPTs

Relevant Speaker PPTs

  • Dassanayake TDMSB
    Comparison of BMI, body fat percentage and lean body weight of national level teenage swimmers and non-swimmers in Sri Lanka
    PPT Version | PDF Version
  • Rasha Mosa
    Effects of growth hormone secretagogue receptor agonist and antagonist in non-obese Type 2 Diabetes MKR mice
    PPT Version | PDF Version
  • Dwi Astuti
    Phylogenetic position of Psittacula parakeet bird from Enggano Island, Indonesia based on analyses of cytochrome b gene sequences
    PPT Version | PDF Version
  • Trent Jackman
    Exploratory comparison of credentialed clinical instructors’ and non-credentialed clinical instructors’ report of frequency and importance of professional behaviors in clinical education
    PPT Version | PDF Version
  • Saraswathi K
    Diagnosis of different stages of non-proliferative diabetic retinopathy
    PPT Version | PDF Version
  • Guldeniz Karadeniz Cakmak
    The importance of intraoperative ultrasound guidance to achieve negative margins for palpable and nonpalpable breast cancer
    PPT Version | PDF Version
  • Elena Bonanno
    Microcalcification as an active phenomenon mediated by epithelial cells with mesenchymal characteristics
    PPT Version | PDF Version
  • Antoine N. Gergess
    Antoine N. Gergess-University-of-Balamand-Lebanon-Cold-Bending-Steel-Beams-a-State-of-The-Art-Engineering-Solution-that-Meets-Industry-Challenges
    PPT Version | PDF Version
  • Gabriela Briceno
    Selection of an actinobacteria consortium for enhancing diazinon degradation
    PPT Version | PDF Version
  • Shree Kumar Apte
    Genetic engineering of Deinococcus radiodurans for uranium bioremediation from high radiation environment
    PPT Version | PDF Version
  • Osama O. Ibrahim
    Chemicals structure, properties, regulations and applications of non-nutritive-high intensity sweeteners
    PDF Version
  • Wendy peters
    A non-replicating Ad5 vaccine for treatment of HSV-2
    PPT Version | PDF Version
  • Randa Hamadeh
    Polio returns to Middle East, situation analysis, strategies and way forward
    PPT Version | PDF Version
  • Yosef Yarden
    Classically, the 3’untranslated region (3’UTR) is that region in eukaryotic protein-coding genes from the translation termination codon to the polyA signal. It is transcribed as an integral part of the mRNA encoded by the gene. However, there exists another kind of RNA, which consists of the 3’UTR alone, without all other elements in mRNA such as 5’UTR and coding region. The importance of independent 3’UTR RNA (referred as I3’UTR) was prompted by results of artificially introducing such RNA species into malignant mammalian cells. Since 1991, we found that the middle part of the 3’UTR of the human nuclear factor for interleukin-6 (NF-IL6) or C/EBP gene exerted tumor suppression effect in vivo. Our subsequent studies showed that transfection of C/EBP 3’UTR led to down-regulation of several genes favorable for malignancy and to up-regulation of some genes favorable for phenotypic reversion. Also, it was shown that the sequences near the termini of the C/EBP 3’UTR were important for its tumor suppression activity. Then, the C/EBP 3’UTR was found to directly inhibit the phosphorylation activity of protein kinase CPKC in SMMC-7721, a hepatocarcinoma cell line. Recently, an AU-rich region in the C/EBP 3’UTR was found also to be responsible for its tumor suppression. Recently we have also found evidence that the independent C/EBP 3’UTR RNA is actually exists in human tissues, such as fetal liver and heart, pregnant uterus, senescent fibroblasts etc. Through 1990’s to 2000’s, world scientists found several 3’UTR RNAs that functioned as artificial independent RNAs in cancer cells and resulted in tumor suppression. Interestingly, majority of genes for these RNAs have promoter-like structures in their 3’UTR regions, although the existence of their transcribed products as independent 3’UTR RNAs is still to be confirmed. Our studies indicate that the independent 3’UTR RNA is a novel non-coding RNA species whose function should be the regulation not of the expression of their original mRNA, but of some essential life activities of the cell as a whole.
    PPT Version | PDF Version
  • Ding-Gan Liu
    Independent 3’untranslated region RNA: A novel non-coding regulator RNA
    PPT Version | PDF Version

Recommended Conferences

Relevant Topics

Peer Reviewed Journals
 
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
 
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

 
© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version
adwords