Coliform group has been extensively used as an indicator of drinking water quality and historically led to the public health protection concept. Multiple tube fermentation technique has been currently used for assessment of the microbial quality of drinking water. This method, however, has limitations. Enzymatic assay constitute an alternative approach for detecting indicator bacteria, namely t...

Atypical fermentation in the two-tube method of Hugh and Leifson (1953), whereby acid was produced in the sealed tube but not in the open tube, was determined to be the result of a preferential metabolism of peptone over the reactant carbohydrate. These atypical fermentations are only partially detected by one-tube oxidation-fermentation methods, and as such they constitute a source of limitati...

The examination of water and other environmental sources for microbial pollution is a major public health undertaking. Currently, there are two accepted methods in use: the multiple-tube fermentation (MTF) and the membrane filtration (MF) tests. Both methods are designed to enumerate the secondary indicator group, total coliforms. Both tests suffer several inherent limitations, including a time...

9 Most probable number (MPN) and colony-forming-unit (CFU) estimates of fecal 10 coliform bacteria concentration are common measures of water quality in coastal 11 shellfish harvesting and recreational waters. Estimating procedures for MPN and 12 CFU have intrinsic variability and are subject to additional uncertainty arising from 13 minor variations in experimental protocol. It has been observ...

BACKGROUND Different target-filter combinations in computed radiography have different impacts on the dose and image quality in digital radiography. This study aims to evaluate the mean glandular dose (MGD) and modulation transfer function (MTF) of various target-filter combinations by investigating the signal intensities of X-ray beams. METHODS General Electric (GE) Senographe DMR Plus mammo...

E-nose (Electronic nose), which is an array of chemical sensors, is widely used in food industry and pollution control. Nowadays e-nose technology has become powerful tool to evaluate the aroma compounds during the quality control process. This work is intended to detect biological water contaminants like coliform group of bacteria in drinking water. However, a number of limitations are associa...

Three methods (membrane filtration, multiple tube fermentation, and chromogenic substrate technology kits manufactured by IDEXX Laboratories, Inc.) are routinely used to measure indicator bacteria for beach water quality. To assess comparability of these methods, quantify within-laboratory variability for each method, and place that variability into context of variability among laboratories usi...

Metal-responsive transcription factor 1 (MTF-1) is essential for activating transcription of the metallothionein genes in response to multiple species of heavy metals by binding to the metal-responsive element (MRE) located in the upstream region of the genes. In contrast, MTF-1 binding to the MRE in vitro is induced only by zinc ions, suggesting that MTF-1 acts as a zinc sensor protein. Althou...