Comparison of a solvent mixture assisted dilute acid and alkali pretreatment in sugar production from hybrid Pennisetum

Abstract(#br)The effects of an acetone-butanol-ethanol (ABE) mixture on dilute H 2 SO 4 and NaOH pretreatment for enzymatic saccharification of hybrid Pennisetum (HP) were investigated. The results showed that ABE assisted the removal of xylan and lignin during H 2 SO 4 and NaOH pretreatment, respectively. The glucose yield of HP increased from 33.6% to 52.9% with the assistance of a relatively higher concentration of ABE mixture (ABE4) during H 2 SO 4 pretreatment, and during NaOH pretreatment, a lower concentration of ABE (ABE2) increased the glucose yield from 64.6% to 80.2%. The hydrolysis yield increases were related to the compositional change and surface characteristics of the pretreated materials. As observed by X-ray photoelectron spectroscopy, ABE4 resulted in a greater lignin content on the surface of materials than that produced by ABE2 during NaOH pretreatment, which possibly increased the non-productive adsorption of cellulase, thus decreasing the hydrolysis yield. The results suggested that an ABE mixture could be used as an auxiliary agent for further increasing of the digestibility of acid- and alkali-pretreated lignocellulosic materials. However, the digestibility was different depending on the concentrations of ABE during acid and alkali pretreatments

Identification of Reference and Biomarker Proteins in Chlamydomonas reinhardtii Cultured under Different Stress Conditions

Reference proteins and biomarkers are important for the quantitative evaluation of protein abundance. Chlamydomonas reinhardtii was grown under five stress conditions (dark, cold, heat, salt, and glucose supplementation), and the OD750 and total protein contents were evaluated on days 0, 1, 2, 4, and 6 of culture. Antibodies for 20 candidate proteins were generated, and the protein expression patterns were examined by western blotting. Reference protein(s) for each treatment were identified by calculating the Pearson’s correlation coefficient (PCC) between target protein abundance and total protein content. Histone H3, beta tubulin 1 (TUB-1), ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit (RBCL), and mitochondrial F1F0 ATP synthase subunit 6 (ATPs-6) were the top reference proteins, because they were expressed stably under multiple stress conditions. The average relative-fold change (ARF) value of each protein was calculated to identify biomarkers. Heat shock protein 90B (HSP90B), flagellar associated protein (FAP127) and ATP synthase CF0 A subunit (ATPs-A) were suitable biomarkers for multiple treatments, while receptor of activated protein kinase C1 (RCK1), biotin carboxylase (BCR1), mitochondrial phosphate carrier protein (MPC1), and rubisco large subunit N-methyltransferase (RMT1) were suitable biomarkers for the dark, cold, heat, and glucose treatments, respectively

The <i>TaPLC1</i> gene expression pattern under drought stress.

<p>(A) The transcriptional expression pattern of <i>TaPLC1</i> under drought stress. First-strand cDNA was synthesized from 1 µg of total RNA and used to perform real-time RT-PCR with gene-specific primers and 18S RNA as an internal control. Plants were analyzed after 0, 0.5, 1, 2, 6, 12, 24, and 48 h. The levels of expression were shown as relative to 0 h, which were set to 1.0. (B and C) The TaPLC protein expression pattern under drought stress. (B) Western blot analysis of TaPLC1 expression under drought stress. Anti-TaPLC1 antibodies were prepared as shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0105061#pone.0105061.s004" target="_blank">Text S1</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0105061#pone.0105061.s001" target="_blank">Figure S1</a>. Anti-actin antibodies were used as an internal control. (C) Plot of the average and standard deviation among three repeats.</p

Characterization of Chlorella sorokiniana growth properties in monosaccharide-supplemented batch culture.

To reveal growth properties of Chlorella sorokiniana UTEX 1230, four monosaccharides (glucose, fructose, galactose and xylose) were individually supplemented into medium as carbon sources for the cultivation of C. sorokiniana UTEX 1230. Supplementation with glucose increased OD750, biomass and lipid yield but decreased protein abundance per unit dry weight of biomass under all concentrations examined, the maximum OD750, biomass and lipid yield increased 2.04, 6.78 and 12.43 times, respectively, compared with autotrophic controls. A low concentration of glucose (<4 g/L) simultaneously promoted the biosynthesis of chlorophylls and protein abundance per unit culture volume, but decreased the lipid content per unit dry weight of biomass and all supplemented glucose can be exhausted within 7 days. Higher glucose concentrations (≥4 g/L) decreased the biosynthesis of chlorophylls and protein abundance per unit culture volume, but increased the lipid content per unit dry weight of biomass. In glucose supplemented scenario, C. sorokiniana UTEX 1230 growth was light-independent. Supplementation with fructose promoted C. sorokiniana UTEX 1230 growth to a much lesser extent compared with glucose, whereas supplementation with galactose had no effect and supplementation with xylose even inhibited growth. Our findings represent basic experimental data on the effect of monosaccharides and can serve as the basis for a robust cultivation system to increase biomass and lipid yield

The relative expression patterns of <i>TaPLC1</i> in different organs of <i>Triticum aestivum</i>.

<p>To determine the expression pattern of <i>TaPLC1</i>, roots, stems, leaves (grown for 6 days), ears, and old leaves (booting stage) were sampled at different developmental stages. Three biological replicates were conducted.</p

Expression Analysis of a Stress-Related Phosphoinositide-Specific Phospholipase C Gene in Wheat (<i>Triticum aestivum L.</i>)

<div><p>Plant phosphoinositide-specific phospholipases C (PI-PLCs) function in several essential plant processes associated with either development or environmental stress. In this report, we examined the expression patterns of <i>TaPLC1</i> under drought and high salinity stress at the transcriptional and post-transcriptional levels. <i>TaPLC1</i> mRNA was expressed in all wheat organs examined. U73122 and edelfosine, the PLC inhibitor, impaired seedling growth and enhanced seedling sensitivity to drought and high salinity stress. Though <i>TaPLC1</i> expression in wheat was lowest at the seedling stage, it was strongly induced under conditions of stress. When 6-day-old wheat seedlings were treated with 200 mM NaCl or 20% (w/v) PEG 6000 for 6 or 12 h, respectively, the <i>TaPLC1</i> transcript level increased by 16-fold compared to the control. Western blotting showed that the TaPLC protein concentration was also maintained at a high level from 24 to 48 h during stress treatment. Together, our results indicate the possible biological functions of <i>TaPLC1</i> in regulating seedling growth and the response to drought and salinity stress.</p></div

Relevant parameters of <i>Triticum aestivum</i> seedlings treated with salt/drought and PI-PLC inhibitors after 6 d.

<p>(A) The seedlings lengths. (B) Fresh weight (FW), n°p seedling number. (C) Relative water content (RWC). (D) chlorophyll content of % control. (E) Malondialdehyde (MDA) content. All data were measured three times and statistically analyzed by one-way Analysis of Variance (ANOVA). * indicate significance at <i>p</i><0.01.</p

The response of <i>Triticum aestivum</i> seedlings to salt and drought stress and treatment with PI-PLC inhibitors.

<p>(A) Seedlings 6 days after sowing. (B) The leaf apex of wheat treated with 20% PEG 6000 after 6 h. (C) The leaf apex of wheat treated with 200 mM NaCl after 6 h. (D). Seedlings treated with 20% PEG 6000 after 6 d. (E) Seedlings treated with 200 mM NaCl after 6 d. (F and G) Under drought stress (F) and salt stress (G), those leaves injected with U73122 (b) showed enhanced sensitivity compared to those injected with U73343 (c) or water (a). (H and I) Under drought stress (H) and salt stress (I), those leaves injected with edelfosine (b) showed enhanced sensitivity compared to those injected with water (c) or un-injected (a). Three biological replicates were conducted.</p

TaPLC is involved in wheat seedling growth.

<p>Pharmacological experiments were used to test the <i>TaPLCs</i> regulating the growth of wheat. Two PI-PLC inhibitors, U73122 and edelfosine were used to treat the seeds and germinated seeds, respectively and the state of the seedlings after three days of growth were recorded. a, PI-PLC inhibitor was added on germinated seeds (− +); b, Inhibitor was added on un-germinated seeds, and remained in the culture medium (+ +); c, Inhibitor was added on un-germinated seeds, but removed from culture medium before the seeds germination (+ −); d, Control i.e. DMSO solution or water was added on germinated seeds (− −). Three biological replicates were conducted.</p