The roles of multiple promoters in the synthesis of rRNA under different conditions of growth were investigated, using two mycobacterial species as model organisms. When Mycobacterium smegmatis was grown under optimal conditions, its two rRNA operons contributed equally, with two promoters, one from each operon, being responsible for most transcripts. In stationary-phase growth or balanced grow...

F eeding antibiotics to animals to make them grow faster has been common practice in intensive agricultural production systems since the late 1950s. In the 1980s, our professors told us that such growth promoters bore no resemblance to antimicrobials being used to treat patients, had no direct animal health effects, and were being used in such low doses that they could not influence the develop...

A large amount of antibiotics has long been used to control pathogenic diseases and as growth promoters to improve performance in livestock. However, this approach had significant and unwanted side-effects, such as development of antimicrobial resistance and carry-over of the antibiotic residues to poultry products. In this light, the use of antibiotics as growth promoters (AGPs) was banned by ...

The E2F family of transcriptional regulators consists of six different members. Analysis of E2F-regulated promoters by using cultured cells suggests that E2Fs may have redundant functions. However, animal studies have shown that loss of individual E2Fs can have distinct biological consequences. Such seemingly conflicting results could be due to a difference in E2F-mediated regulation in cell cu...

In gram-negative bacteria, iron acquisition proteins are commonly regulated by Fur (ferric uptake regulator), which binds iron-regulated promoters (the Fur box). We hypothesized that Coxiella burnetii requires iron and employs an iron-regulatory system and used various approaches to define a Fur regulon. Cloned C. burnetii fur complemented an Escherichia coli fur deletion mutant. A ferrous iron...

Poultry market has been demonstrating emerging potential as an efficient producer of meat with consumption occupying 40.6% globally. The requirement animal protein is anticipated to grow continuously for meeting the requirements by ever-growing human population. To fulfill this demand, major challenge encountered poultry breeders was fasten production in most and economical way. Use antibiotic ...

Livestock including cattle, goats, sheep, pigs and poultry are kept under traditional farming systems producing manure, supporting crop production, insurance financing emergency cash needs, improving social status. The livestock feed resource base is mostly natural graze residues whose quality supply dependent upon unreliable rainfall patterns. Due to rising demand for cropland, overgrazing, bu...

Antibiotic growth promoters (AGPs) are commonly used within poultry farming to increase muscle growth. Microbial composition in the gut is known be influenced by AGP use although exact AGP-induced changes remain unclear.