Identification and characterization of two novel IS-associated genes and encoding trimethoprim resistant dihydrofolate reductases.

Two novel IS-associated genes, and , were identified from trimethoprim (TMP)-resistant strains and were shown to confer high level TMP resistance (MIC ≥ 1024 mg/L) when cloned into These genes were hosted by complex class 1 integrons suggesting their potentials for dissemination. Analysis of enzymatic parameters and TMP affinity were performed, suggesting that the mechanism of TMP resistance for these novel DHFRs is the reduction of binding with TMP.

Plasticized hemicelluloses/chitosan-based edible films reinforced by cellulose nanofiber with enhanced mechanical properties.

In this work, the properties of the plasticized hemicelluloses/chitosan-based edible films reinforced by cellulose nanofiber (CNF) have been evaluated. Results showed that the tensile strength (TS) of the film increased by 2.3 times with adding 5% CNF.

Use of xylooligosaccharides (XOS) in hemicelluloses/chitosan-based films reinforced by cellulose nanofiber: Effect on physicochemical properties.

Edible packaging films play an important role in extending the shelf life of food products. In this work, the properties of cellulose nanofiber (CNF) reinforced hemicelluloses/chitosan-based edible films with xylooligosaccharides (XOS) have been evaluated. Results showed that the tensile strength (TS) of the film can be increased by 2.

Unraveling the Fate of Lignin from Eucalyptus and Poplar during Integrated Delignification and Bleaching.

Efficient deconstruction of lignocellulose is vitally important for the biorefinery industry because lignin structures play a crucial role in the high value-added conversion of lignin. In this study, an integrated process based on hydrothermal pretreatment (HTP) and Kraft delignification was proposed to deconstruct lignocellulosic biomass. It was found that the HTP not only facilitated the production of xylo-oligosaccharides but also reduced the chemicals dosage of the following delignification.

Rapid fabrication of ionic liquid-functionalized monolithic column via in-situ urea-formaldehyde polycondensation for pressurized capillary electrochromatography.

A novel strategy for rapidly fabricating ionic liquid (IL)-bonded multifunctional monolithic stationary phase has been developed by an in-situ polycondensation of urea-formaldehyde (UF) and a lab-made acylamino-functionalized IL (1-acetylamino-propyl-3-methylimidazolium bromide, [AAPMIm]Br). Two polycondensation processes of UF with 1-amino-propyl-3-methylimidazolium bromide or [AAPMIm]Br were evaluated. Several parameters including mass ratio of urea-formaldehyde, amount of [AAPMIm]Br, polycondensation time and reaction temperature were optimized, and the [AAPMIm]Br-bonded monolithic stationary phase could be rapidly synthesized in 10min with a satisfactory permeability and mechanical stability.

Identification of plasmid-mediated quinolone resistance qnr genes in multidrug-resistant Gram-negative bacteria from hospital wastewaters and receiving waters in the Jinan area, China.

We investigated the prevalence of plasmid-mediated quinolone resistance (PMQR) qnr genes by the polymerase chain reaction (PCR) in antibiotic-resistant bacteria isolates collected from aquatic environments in Jinan during 2 years (2008.3-2009.11).

The identification of and relief from Fe3+ inhibition for both cellulose and cellulase in cellulose saccharification catalyzed by cellulases from Penicillium decumbens.

Lignocellulosic biomass is an underutilized, renewable resource that can be converted to biofuels. The key step in this conversion is cellulose saccharification catalyzed by cellulase. In this work, the effect of metal ions on cellulose hydrolysis by cellulases from Penicillium decumbens was reported for the first time.

Molecular diversity of class 2 integrons in antibiotic-resistant gram-negative bacteria found in wastewater environments in China.

The molecular architecture of class 2 integrons among gram-negative bacteria from wastewater environments was investigated in Jinan, China. Out of the 391 antibiotic-resistant bacteria found, 38 isolates harboring class 2 integrons encoding potentially transferrable genes that could confer antibiotic resistance were found. These isolates were classified into 19 REP-PCR types.

[Enhanced cellulase production of Penicillium decumbens by knocking out CreB encoding a deubiquitination enzyme].

Penicillium decumbens T. is an important filamentous fungus for the production of cellulases to effectively degrade lignocellulose for second generation biofuel production. In order to enhance the capability of Penicillium decumbens to produce cellulases, we constructed a creB (a deubiquitinating enzyme encoding gene) deletion cassette, and generated a creB knockout strain with homologous double crossover recombination.

qnrVC-like gene located in a novel complex class 1 integron harboring the ISCR1 element in an Aeromonas punctata strain from an aquatic environment in Shandong Province, China.

A qnrVC-like gene, qnrVC4, was found in a novel complex class 1 integron gene cassette array following the ISCR1 element and bla(PER-1) in a multidrug-resistant strain of the aquatic bacterium Aeromonas punctata. The deduced QnrVC4 protein sequence shares 45% to 81% amino acid identity with quinolone resistance determinants QnrB6, QnrA1, QnrS1, QnrC, QnrVC1, and QnrVC3. A Ser-83 to Ile amino acid substitution in gyrase A may be mainly responsible for ciprofloxacin resistance in this strain.