BACKGROUND Pollution due to the heavy metals is a problem that may have negative consequences on the hydrosphere. One of the best procedures in removing the toxic metals from the environment is using metal resistant bacteria. RESULTS In the present study eight nickel resistant bacteria were isolated from industrial wastewaters. Three of them were selected as the most resistant based on their ...

Introduction Microorganisms regulate soil nitrogen (N) cycling in cropping systems. However, how microbial functional genes involved N respond to mulching practices is not well known. Methods We collected samples from a spring maize field mulched with crop straw (SM) and plastic film (FM) for 10-year no (CK) the Loess Plateau. Microbial were quantified using metagenomic sequencing. Results Comp...

The genes encoding murine macrophage migration inhibitory factor (MIF), IL-2, IFN-gamma or TNF-alpha were cloned individually into an expression plasmid under the control of the inducible promoter nirB and transfected into the aroA- aroD- deletion mutant strain of Salmonella typhimurium (BRD509). These S. typhimurium derivatives (henceforward called constructs and termed GIDMIF, GIDIL2, GIDIFN ...

Fas-associated protein with death domain (FADD), a pivotal adaptor protein transmitting apoptotic signals, is indispensable for the induction of extrinsic apoptosis. However, overexpression of FADD can form large, filamentous aggregates, termed death effector filaments (DEFs) by self-association and initiate apoptosis independent of receptor cross-linking. A mutant of FADD, which is truncated o...

Characterization of a nitrite reductase-negative Staphylococcus carnosus Tn917 mutant led to the identification of the nir operon, which encodes NirBD, the dissimilatory NADH-dependent nitrite reductase; SirA, the putative oxidase and chelatase, and SirB, the uroporphyrinogen III methylase, both of which are necessary for biosynthesis of the siroheme prosthetic group; and NirR, which revealed n...

The C-terminal repeat domain of Clostridium difficile toxin A harbors toxin-neutralizing epitopes and is considered to be a candidate component of a vaccine against C. difficile-associated disease (CDAD). Fourteen of the 38 C-terminal toxin A repeats (14CDTA) were cloned into pTECH-1 in frame with the immunogenic fragment C of tetanus toxin (TETC) to generate plasmid p56TETC. Expression of the ...

A substantially improved purification of Escherichia coli NADH-dependent nitrite reductase was obtained by purifying it in the presence of 1 mM-NO2and 10,uM-FAD. The enzyme was obtained in 20% yield with a maximum specific activity of 1.04 kat . kg-1: more than 95% of this sample subjected to sodium dodecyl sulphate/polyacrylamide-gel electrophoresis migrated as a single band of protein. This h...

Nitrite, either exogenously supplied or endogenously generated by nitrate reduction, activates transcription of the nitrate assimilation operon (nirA-nrtABCD-narB) in Synechococcus sp. strain PCC 7942 cells treated with L-methionine-DL-sulfoximine (an inhibitor of glutamine synthetase), in which there is no negative feedback resulting from fixation of the ammonium generated by nitrite reduction...