Application of solid-acid catalyst and marine macro-algae Gracilaria verrucosa to production of fermentable sugars.

In this study, the hydrolysis of marine macro-algae Gracilaria verrucosa with a solid-acid catalyst was investigated. To optimize the hydrolysis, four reaction factors, including liquid-to-solid ratio, catalyst loading, reaction temperature, and reaction time, were investigated. In the results, the highest total reducing sugar (TRS) yield, 61 g/L (51.

Overview on the biotechnological production of L-DOPA.

L-DOPA (3,4-dihydroxyphenyl-L-alanine) has been widely used as a drug for Parkinson's disease caused by deficiency of the neurotransmitter dopamine. Since Monsanto developed the commercial process for L-DOPA synthesis for the first time, most of currently supplied L-DOPA has been produced by the asymmetric method, especially asymmetric hydrogenation. However, the asymmetric synthesis shows critical limitations such as a poor conversion rate and a low enantioselectivity.

Recovery of algal oil from marine green macro-algae Enteromorpha intestinalis by acidic-hydrothermal process.

In this study, the recovery of algal oil from Enteromorpha intestinalis based on an acidic-hydrothermal reaction was investigated. Overall, the algal oil yield after the acidic-hydrothermal reaction was increased under the conditions of high reaction temperature, high catalyst concentration, and long reaction time within the tested ranges. Significantly, catalyst concentration, compared with reaction temperature and time, less affected algal oil recovery.

Conversion of red-algae Gracilaria verrucosa to sugars, levulinic acid and 5-hydroxymethylfurfural.

This study employed a statistical methodology to investigate the optimization of conversion conditions and evaluate the reciprocal interaction of reaction factors related to the process of red-algae Gracilaria verrucosa conversion to sugars (glucose, galactose), levulinic acid and 5-hydroxymethylfurfural (5-HMF) by acidic hydrolysis. Overall, the conditions optimized for glucose formation included a higher catalyst concentration than did those for galactose, and these conditions for galactose were similar to those for 5-HMF. Levulinic acid production, meanwhile, was optimized at a higher reaction temperature, a higher catalyst concentration, and a longer reaction time than was glucose, galactose or 5-HMF production.

Transcriptome analysis of salt-stressed Deinococcus radiodurans and characterization of salt-sensitive mutants.

Deinococcus radiodurans is a bacterium best known for its extreme resistance to high levels of ionizing radiation. Gene expression profiles of D. radiodurans exposed to 0.

Effects of inorganic salts on pretreatment of Miscanthus straw.

This study focused on the effects of five inorganic salts, NaCl, KCl, CaCl2, ZnCl2, and FeCl3, on the pretreatment of Miscanthus straw for sugar recovery and enzymatic digestibility. In the results, all of the salts reduced the hemicellulose content in the straw. Most notably, FeCl3 effected almost 100% xylan removal.

Effects of NH4Cl and MgCl(2) on pretreatment and xylan hydrolysis of miscanthus straw.

This study investigated the effects of NH(4)Cl and MgCl(2) on pretreatment and xylan hydrolysis of miscanthus straw for biofuels production. It was observed that increasing the pretreatment temperature decreased the remaining solid, increased the enzymatic digestibility, and increased the xylan removal. When 0.

An ammonium sulfate sensitive endoxylanase produced by Streptomyces.

Streptomyces sp. CSWu2 was newly isolated and identified from Korean soil. In culture medium, the strain produced a highly active endoxylanase (Xynwu2), which was purified to homogeneity by a single-step chromatography on Poros-HQ.

Sonication-assisted production of biodiesel using soybean oil and supercritical methanol.

High temperature and pressure are generally required to produce biodiesel using supercritical methanol. We reduced the harsh reaction conditions by means of sonicating the reaction mixture prior to transesterification using supercritical methanol. Soybean oil was selected as the raw material for transesterification.

Proteomic analysis of Spirogyra varians mutant with high starch content and growth rate induced by gamma irradiation.

This study was conducted to develop a high-efficiency strain of Spirogyra varians for the production of biomass by radiation breeding. The characteristics of wild-type and mutant S. varians were analyzed through phenomenological and proteomic observations.

Efficient production of 1,3-propanediol from glycerol upon constitutive expression of the 1,3-propanediol oxidoreductase gene in engineered Klebsiella pneumoniae with elimination of by-product formation.

In the present study, we developed an efficient method of 1,3-propanediol (1,3-PD) production from glycerol by genetic engineering of Klebsiella pneumoniae AK mutant strains. The proposed approach eliminated by-product formation and IPTG induction resulted in maximal production of 1,3-PD. A series of recombinant strains was designed to constitutively express the dhaB and/or dhaT genes, using the bacteriophage T5 P(DE20) promoter and the rho-independent transcription termination signal of the Rahnella aquatilis levansucrase gene.

Effect of fermentation inhibitors in the presence and absence of activated charcoal on the growth of Saccharomyces cerevisiae.

The acidic hydrolysis of biomass generates numerous inhibitors of fermentation, which adversely affect cell growth and metabolism. The goal of the present study was to determine the effects of fermentation inhibitors on growth and glucose consumption by Saccharomyces cerevisiae. We also conducted in situ adsorption during cell cultivation in synthetic broth containing fermentation inhibitors.

Comparative survival analysis of 12 histidine kinase mutants of Deinococcus radiodurans after exposure to DNA-damaging agents.

Bacteria are able to adapt to changes in the environment using two-component signal transduction systems (TCSs) composed of a histidine kinase (HK) and a response regulator (RR). Deinococcus radiodurans, one of the most resistant organisms to ionizing radiation, has 20 putative HKs and 25 putative RRs. In this study, we constructed 12 D.

Rapeseed-straw enzymatic digestibility enhancement by sodium hydroxide treatment under ultrasound irradiation.

In this study, we carried out sodium hydroxide and sonication pretreatments of rapeseed straw (Brassica napus) to obtain monosugar suitable for production of biofuels. To optimize the pretreatment conditions, we applied a statistical response-surface methodology. The optimal pretreatment conditions using sodium hydroxide under sonication irradiation were determined to be 75.

A study on the electrochemical synthesis of L-DOPA using oxidoreductase enzymes: optimization of an electrochemical process.

Levodopa or L-3,4-dihydroxyphenylalanine (L-DOPA) is the precursor of the neurotransmitter dopamine. L-DOPA is a famous treatment for Parkinson's disease symptoms. In this study, electroenzymatic synthesis of L-DOPA was performed in a three-electrode cell, comprising a Ag/AgCl reference electrode, a platinum wire auxiliary electrode, and a glassy carbon working electrode.

Light-regulated melatonin biosynthesis in rice during the senescence process in detached leaves.

The effect of light on melatonin biosynthesis was examined in detached rice (Oryza sativa cv. Asahi) leaves during the senescence process. The detached leaves were exposed to senescence treatment either in constant darkness or in constant light, and subjected to HPLC analysis for melatonin and its precursors.

Pretreatment of rapeseed straw by sodium hydroxide.

Pretreatment method for rapeseed straw by sodium hydroxide was investigated for production of bioethanol and biobutanol. Various pretreatment parameters, including temperature, time, and sodium hydroxide concentration were optimized using a statistical method which is a central composite design of response surface methodology. In the case of sodium hydroxide pretreatment, optimal pretreatment conditions were found to be 7.

Optimization of culture conditions for 1,3-propanediol production from glycerol using a mutant strain of Klebsiella pneumoniae.

In the present work, mutant strains of Klebsiella pneumoniae with deletions of the als gene encoding acetolactate synthase involved in synthesis of 2,3-butanediol, the ldhA gene encoding lactate dehydrogenase required for lactate synthesis, or both genes, were prepared. Production of 1,3-propanediol (1,3-PD) from glycerol was enhanced in the ldhA mutant strain (ΔldhA), but lower in Δals or Δals ΔldhA mutant strains compared to the parent strain, concomitant with a reduction in the glycerol consumption rate, indicating that deletion of ldhA alone was useful to improve 1,3-PD production. Fed-batch fermentation analysis revealed that, in the ΔldhA mutant strain, 1,3-PD production was higher at low pH than at neutral pH; the reverse was true for the parent strain.

Fermentation strategies for 1,3-propanediol production from glycerol using a genetically engineered Klebsiella pneumoniae strain to eliminate by-product formation.

We generated a genetically engineered Klebsiella pneumoniae strain (AK-VOT) to eliminate by-product formation during production of 1,3-propanediol (1,3-PD) from glycerol. In the present study, the glycerol-metabolizing properties of the recombinant strain were examined during fermentation in a 5 L bioreactor. As expected, by-product formation was completely absent (except for acetate) when the AK-VOT strain fermented glycerol.

Immobilization of cellulase from newly isolated strain Bacillus subtilis TD6 using calcium alginate as a support material.

Bacillus subtilis TD6 was isolated from Takifugu rubripes, also known as puffer fish. Cellulase from this strain was partially purified by ammonium sulphate precipitation up to 80% saturation, entrapped in calcium alginate beads, and finally characterized using CMC as the substrate. For optimization, various parameters were observed, including pH maximum, temperature maximum, sodium alginate, and calcium chloride concentration.

Pretreatment of rapeseed straw by soaking in aqueous ammonia.

Pretreatment of lignocellulosic biomass has gained attention for production of biofuels. In this study, pretreatment by soaking in aqueous ammonia was adopted for pretreatment of biomass for ethanol production. A central composite design of response surface methodology was used for optimization of the pretreatment condition of rapeseed straw, with respect to catalyst concentration, pretreatment time, and pretreatment temperature.

A novel cold-adapted lipase, LP28, from a mesophilic Streptomyces strain.

Fossil fuel is limited but its usage has been growing rapidly, thus the fuel is predicted to be completely running out and causing an unbearable global energy crisis in the near future. To solve this potential crisis, incorporating with increasing environmental concerns, significant attentions have been given to biofuel production in the recent years. With the aim of isolating a microbial biocatalyst with potential application in the field of biofuel, a lipase from Streptomyces sp.

A novel alkaline lipase from Ralstonia with potential application in biodiesel production.

With the aim of isolating a biocatalyst able to catalyze biodiesel production from microbial source, Ralstonia sp. CS274 was isolated and a lipase from the strain (RL74) was purified. Molecular weight of RL74 was estimated to be 28,000 Da by SDS-PAGE.