Purcellbjerregaard8079

Azo dyes are toxic and carcinogenic synthetic pigments that accumulate as pollutants in aquatic bodies near textile factories. The pigments are structurally diverse, and bioremediation is mostly limited to single dye compounds or related groups. Versatile peroxidase (VP) from Pleurotus eryngii is a heme-containing peroxidase with a broad substrate spectrum that can break down many structurally distinct pollutants, including azo dyes. The utilization of this enzyme could be facilitated by engineering to modify its catalytic activity and substrate range. We used saturation mutagenesis to alter two amino acids in the catalytic tryptophan environment of VP (V160 and A260). Library screening with three azo dyes revealed that these two positions had a significant influence on substrate specificity. We were able to isolate and sequence VP variants with up to 16-fold higher catalytic efficiency for different azo dyes. The same approach could be used to select for VP variants that catalyze the degradation of many other types of pollutants. To allow multiple cycles of dye degradation, we immobilized VP on the surface of yeast cells and used washed cell wall fragments after lysis. VP embedded in the cell wall retained ∼70 % of its initial activity after 10 cycles of dye degradation each lasting 12 h, making this platform ideal for the bioremediation of environments contaminated with azo dyes. The CRISPR/Cas9 system has been successfully applied for gene editing in filamentous fungi. Previous studies reported that single stranded oligonucleotides can be used as repair templates to induce point mutations in some filamentous fungi belonging to genus Aspergillus. In Aspergillus niger, extensive research has been performed on regulation of plant biomass degradation, addressing transcription factors such as XlnR or GaaR, involved in (hemi-)cellulose and pectin utilization, respectively. Single nucleotide mutations leading to constitutively active forms of XlnR and GaaR have been previously reported. However, the mutations were performed by the introduction of versions obtained through site-directed or UV-mutagenesis into the genome. Here we report a more time- and cost-efficient approach to obtaining constitutively active versions by application of the CRISPR/Cas9 system to generate the desired mutation on-site in the A. niger genome. This was also achieved using only 60-mer single stranded oligonucleotides, shorter than the previously reported 90-mer strands. In this study, we show that CRISPR/Cas9 can also be used to efficiently change functional properties of the proteins encoded by the target gene by on-site genomic mutations in A. Taurocholic acid compound library chemical niger. The obtained strains with constitutively active XlnR and GaaR versions resulted in increased production of plant biomass degrading enzymes and improved release of d-xylose and l-arabinose from wheat bran, and d-galacturonic acid from sugar beet pulp. Biomass from oil palm frond leaves (OPFL) is an excellent reservoir of lignocellulosic material which full potential remains untapped. This study aimed to statistically optimize the covalent immobilization of Candida rugosa lipase (CRL) onto a ternary support comprised of OPFL derived nanocellulose (NC) and montmorillonite (MMT) in alginate (ALG) (CRL-ALG/NC/MMT). The coarser topology and the presence of characteristic spherical globules in the field emission scanning electron micrographs and atomic force micrographs, respectively, supported the existence of CRL on ALG/NC/MMT. In addition, amide peaks at 3478 and 1640 cm-1 in the fourier transform infrared spectra affirmed that CRL was covalently bonded to ALG/NC/MMT. The optimized Taguchi Design-assisted immobilization of CRL onto ALG/NC/MMT (7 h of immobilization, 35℃, pH 5, 7 mg/mL protein loading) gave a production yield of 92.89 % of ethyl levulinate (EL), as proven by gas chromatography-mass spectrometric ([M] +m/z 144, C7H12O3), FTIR and nuclear magnetic resonance (CAS-539-88-8) data. A higher optimal reaction temperature (50℃) and the reusability of CRL-ALG/NC/MMT for up to 9 esterification cycles substantiated the appreciable structural rigidification of the biocatalyst by ALG/NC/MMT, which improved the catalytic activity and thermal stability of the lipase. To elucidate the functional alteration of the recombinant hybrid chitinases composed of bacterial and insect's domains, we cloned the constitutional domains from chitinase-encoding cDNAs of a bacterial species, Bacillus thuringiensis (BtChi) and a lepidopteran insect species, Mamestra brassicae (MbChi), respectively, swapped one's leading signal peptide (LSP) - catalytic domain (CD) - linker region (LR) (LCL) with the other's chitin binding domain (ChBD) between the two species, and confirmed and analyzed the functional expression of the recombinant hybrid chitinases and their chitinolytic activities in the transformed E. coli strains. Each of the two recombinant cDNAs, MbChi's LCL connected with BtChi's ChBD (MbLCL-BtChBD) and BtChi's LCL connected with MbChi's ChBD (BtLCL-MbChBD), was successfully introduced and expressed in E. coli BL21 strain. Although both of the two hybrid enzymes were found to be expressed by SDS-PAGE and Western blotting, the effects of the introduced genes on the chitin metabolism appear to be dramatically different between the two transformed E. coli strains. BtLCL-MbChBD remarkably increased not only the cell proliferation rate, extracellular and cellular chitinolytic activity, but also cellular glucosamine and N-acetylglucosamine levels, while MbLCL-BtChBD showed about the same profiles in the three tested subjects as those of the strains transformed with each of the two native chitinases, indicating that a combination of the bacterial CD of TIM barrel structure with characteristic six cysteine residues and insect ChBD2 including a conserved six cysteine-rich region (6C) enhances the attachment of the enzyme molecule to chitin compound by MbChBD, and so increases the catalytic efficiency of bacterial CD. Atrial fibrillation (AF) is a common perioperative arrhythmia. However, its occurrence and implications remain poorly defined in the setting of noncardiac procedures. We sought to define the incidence, prevalence, and prognostic implications of AF among patients with atherosclerotic cardiovascular disease (ASCVD) undergoing noncardiac surgery. Using a previously validated approach that employed unique patient-linked variables in the New York State Inpatient Database from January 1, 2012, to December 31, 2014, the frequency of new-onset and pre-existing AF was determined in adults with ASCVD aged ≥18 years undergoing noncardiac surgery. The secondary outcomes were stroke within 1 month and all-cause mortality. Using multivariable logistic regression models, the factors and outcomes associated with new-onset AF after noncardiac surgery were assessed. Nine surgical subgroups of major noncardiac surgery served as exposure. A total of 184,775 patients were identified during the study period. Age ≥65, anemia, history of heart failure, valvular heart disease, and thoracic surgery were predictors of new-onset AF after noncardiac surgery.