Microbial production of xanthan gum from forage sorghum straw (FSS) was investigated. The important aspect investigated was the synthesis of xanthan gum using hemicellulose as a substrate (hemicellulose-derived xanthan), a process that has been relatively underexplored in the existing literature. Xanthomonas campestris ATCC 33913 and an isolated strain from orange peel, identified as X.
View Article and Find Full Text PDFXylose plants (produce xylose from corncob through dilute acid treatment) generate a large amount of corncob residue (CCR), most of which are burned and lacked of valorization. Herein, to address this issue, CCR was directly used as starting material for high-solid loading enzymatic hydrolysis via a simple strategy by combining PFI homogenization (for sufficient mixing) with batch-feeding. A maximum glucose concentration of 187.
View Article and Find Full Text PDFPseudomonas putida is a soil bacterium with multiple uses in fermentation and biotransformation processes. P. putida ATCC 12633 can biotransform benzaldehyde and other aldehydes into valuable α-hydroxyketones, such as (S)-2-hydroxypropiophenone.
View Article and Find Full Text PDFDespite the current use of some Bacillus spp. as probiotics, looking for and introducing new efficient and safe potential probiotic strains is one of the most important topics in both microbiology and food industry. This study aimed to isolate, identify, and evaluate the probiotic characteristics and safety of some Bacillus spp.
View Article and Find Full Text PDFBackground: Aromatic α-hydroxy ketones, such as S-2-hydroxypropiophenone (2-HPP), are highly valuable chiral building blocks useful for the synthesis of various pharmaceuticals and natural products. In the present study, enantioselective synthesis of 2-HPP was investigated by free and immobilized whole cells of Pseudomonas putida ATCC 12633 starting from readily-available aldehyde substrates. Whole resting cells of P.
View Article and Find Full Text PDFCostly cofactors such as nicotinamide adenine dinucleotide hydrogen (NADH) are essential to have high activity in many redox enzymatic processes. Cofactor regeneration methods have been suggested to improve the economic aspects of the system. Here, we introduce a microbial electrosynthesis process to regenerate NADH in a two-chamber set-up with Enterobacter aerogenes biofilm as the bio-cathode.
View Article and Find Full Text PDFThe bioconversion of lignocellulose into monosaccharides is critical for ensuring the continual manufacturing of biofuels and value-added bioproducts. Enzymatic degradation, which has a high yield, low energy consumption, and enhanced selectivity, could be the most efficient and environmentally friendly technique for converting complex lignocellulose polymers to fermentable monosaccharides, and it is expected to make cellulases and xylanases the most demanded industrial enzymes. The widespread nature of thermophilic microorganisms allows them to proliferate on a variety of substrates and release substantial quantities of cellulases and xylanases, which makes them a great source of thermostable enzymes.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
February 2021
Methylation of DNA at carbon 5 of cytosines is the most common epigenetic modification of human genome. Due to its critical role in many normal cell processes such as growth and development, any aberrant methylation pattern in a particular locus may lead to abnormal functions and diseases such as cancer. Development of methods to detect methylation state of DNA which may eliminate labor-intensive chemical or enzymatic treatments has received considerable attention in recent years.
View Article and Find Full Text PDFObjectives: The yeast cells were coated with FeO magnetic nanoparticles and employed as biocatalyst for the microbial biotransformation of benzaldehyde into L-phenylacetylcarbinol (L-PAC).
Results: Saccharomyces cerevisiae CEN.PK113-7D yeast cells were coated with magnetic nanoparticles to facilitate the cells separation process.
L-Phenylacetylcarbinol (L-PAC) which is used as a precursor for the production of ephedrine and pseudoephedrine is the first reported biologically produced α-hydroxy ketone compound. l-PAC is commercially produced by the yeast Saccharomyces cerevisiae. Yeast cells transform exogenously added benzaldehyde into l-PAC by using the action of pyruvate decarboxylase (PDC) enzyme.
View Article and Find Full Text PDFThe extent of DNA structural perturbation by silver ions is different in methylated and non-methylated DNA. Here, we explored the interaction of eight convenient DNA interacting molecules with methylated and non-methylated short GC rich oligonucleotides in the presence and absence of silver ions. Acridine orange, DAPI, Doxorubicin, Ethidium bromide, Hoechst 33342, Methylene blue, PicoGreen, and Propidium iodide are tested for their ability to distinguish methylated and non-methylated DNA.
View Article and Find Full Text PDFDetermining methylation state of a particular DNA sequence is an essential task in many epigenetic investigations. Here a facile method based on silver nanocluster (AgNCs) fluorescence enhancement is presented. Target sequences were selected from Sept9 promoter region that its hypermethylation is demonstrated as a reliable biomarker of colorectal cancer.
View Article and Find Full Text PDFMethods Appl Fluoresc
September 2018
Among epigenetic modifications of DNA, methylation of cytosine at its carbon 5 is the most common mark that is usually associated with gene silencing in human. Determining whether a particular DNA molecule is methylated or not, is an indispensable task in many epigenetic investigations. Presenting detection methods with less labor-intensive and time-consuming procedures has substantial value.
View Article and Find Full Text PDFMater Sci Eng C Mater Biol Appl
September 2016
Poly(lactic-co-glycolic acid) (PLGA) and PLGA/gelatin random nanofibrous scaffolds embedded with different amounts of mesoporous silica nanoparticles (MSNPs) were fabricated using electrospinning method. To evaluate the effects of nanoparticles on the scaffolds, physical, chemical, and mechanical properties as well as in vitro degradation behavior of scaffolds were investigated. The mean diameters of nanofibers were 974±68nm for the pure PLGA scaffolds vs 832±70, 764±80, and 486±64 for the PLGA/gelatin, PLGA/10wt% MSNPs, and the PLGA/gelatin/10wt% MSNPs scaffolds, respectively.
View Article and Find Full Text PDFObjectives: To engineer the yeast Saccharomyces cerevisiae for the heterologous production of linalool.
Results: Expression of linalool synthase gene from Lavandula angustifolia enabled heterologous production of linalool in S. cerevisiae.
Production of xanthan gum using immobilized cells of Xanthomonas campestris and Xanthomonas pelargonii grown on glucose or hydrolyzed starch as carbon sources was investigated. Calcium alginate (CA) and calcium alginate-polyvinyl alcohol-boric acid (CA-PVA) beads were used for the immobilization of cells. Xanthan titers of 8.
View Article and Find Full Text PDFAligned poly lactic-co-glycolic acid (PLGA) and PLGA/gelatin nanofibrous scaffolds embedded with mesoporous silica nanoparticles (MSNPs) were fabricated using electrospinning method. The mean diameters of nanofibers were 641±24 nm for the pure PLGA scaffolds vs 418±85 nm and 267±58 nm for the PLGA/10 wt% MSNPs and the PLGA/gelatin/10 wt% MSNPs scaffolds, respectively. The contact angle measurement results (102°±6.
View Article and Find Full Text PDFInt J Biol Macromol
February 2015
Metallothioneins (MTs) are low-molecular weight proteins with high Cys content and a high affinity for metals. Plant MTs are classified into four types based on the arrangement of Cys in their amino acid sequences. In the present study, the gene encoding OsMTI-3a, a type 3 MT found in rice, was cloned into pET41a vector.
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