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Full-Text Articles in Biotechnology

High-Temperature Fluorescent In Situ Hybridization For Detecting Escherichia Coli In Seawater Samples, Using Rrna-Targeted Oligonucleotide Probes And Flow Cytometry, Ying Zhong Tang, Karina Yew Hoong Gin, Tok Hoon Lim Jan 2005

High-Temperature Fluorescent In Situ Hybridization For Detecting Escherichia Coli In Seawater Samples, Using Rrna-Targeted Oligonucleotide Probes And Flow Cytometry, Ying Zhong Tang, Karina Yew Hoong Gin, Tok Hoon Lim

OES Faculty Publications

Fluorescence in situ hybridization (FISH) is a widely used method to detect environmental microorganisms. The standard protocol is typically conducted at a temperature of 46°C and a hybridization time of 2 or 3 h, using the fluorescence signal intensity as the sole parameter to evaluate the performance of FISH. This paper reports our results for optimizing the conditions of FISH using rRNA-targeted oligonucleotide probes and flow cytometry and the application of these protocols to the detection of Escherichia coli in seawater spiked with E. coli culture. We obtained two types of optimized protocols for FISH, which showed rapid results with …


A Computer-Simulated Restriction Fragment Length Polymorphism Analysis Of Bacterial Small-Subunit Rrna Genes: Efficacy Of Selected Tetrameric Restriction Enzymes For Studies Of Microbial Diversity In Nature, Craig L. Moyer, James M. Tiedje, Fred C. Dobbs, David M. Karl Jul 1996

A Computer-Simulated Restriction Fragment Length Polymorphism Analysis Of Bacterial Small-Subunit Rrna Genes: Efficacy Of Selected Tetrameric Restriction Enzymes For Studies Of Microbial Diversity In Nature, Craig L. Moyer, James M. Tiedje, Fred C. Dobbs, David M. Karl

OES Faculty Publications

An assessment of 10 tetrameric restriction enzymes (TREs) was conducted by using a computer-simulated restriction fragment length polymorphism (RFLP) analysis for over 100 proximally and distally related bacterial small-subunit (SSU) rRNA gene sequences. Screening SSU rDNA clone libraries with TREs has become an effective strategy because of logistic simplicity, commercial availability, and economy. However, the rationale for selecting the type and number of TREs has not been systematically evaluated. Our objective nas to identify the optimal combination of TREs for RnP screening of cloned SSU rRNA genes from undefined bacterial clone libraries. After computer-simulated TRE digestion, the resultant fragments were …


Phylogenetic Diversity Of The Bacterial Community From A Microbial Mat At An Active, Hydrothermal Vent System, Loihi Seamount, Hawaii, Craig L. Moyer, Fred C. Dobbs, David M. Karl Apr 1995

Phylogenetic Diversity Of The Bacterial Community From A Microbial Mat At An Active, Hydrothermal Vent System, Loihi Seamount, Hawaii, Craig L. Moyer, Fred C. Dobbs, David M. Karl

OES Faculty Publications

The phylogenetic diversity of small-subunit rRNA genes associated,vith the domain Bacteria was examined (by using previously defined operational taxonomic units [C. L. Moyer, F. C. Dobbs, and D. M. Karl, Appl. Environ. Microbiol. 60:871-879, 1994]; those for Pele's Vents Bacteria are hereafter abbreviated PVB OTUs) with samples from a microbial mat at an active, deep-sea hydrothermal vent system. A cluster of phylogenetically related PVB OTUs (OTUs 2, 3, 6, and 8) was closely affiliated with Thiovulum sp. contained within the epsilon subclass of the class Proteobacteria and accounted for 60.5% of the small-subunit rRNA bacterial clone library from Pele's Vents. …


Estimation Of Diversity And Community Structure Through Restriction-Fragment-Length-Polymorphism Distribution Analysis Of Bacterial 16s Ribosomal-Rna Genes From A Microbial Mat At An Active, Hydrothermal Vent System, Loihi Seamount, Hawaii, Craig L. Moyer, Fred C. Dobbs, David M. Karl Mar 1994

Estimation Of Diversity And Community Structure Through Restriction-Fragment-Length-Polymorphism Distribution Analysis Of Bacterial 16s Ribosomal-Rna Genes From A Microbial Mat At An Active, Hydrothermal Vent System, Loihi Seamount, Hawaii, Craig L. Moyer, Fred C. Dobbs, David M. Karl

OES Faculty Publications

PCR was used to amplify (eu)bacterial small-subunit (16S) rRNA genes from total-community genomic DNA. The source of total-community genomic DNA used for this culture-independent analysis was the microbial mats from a deep-sea, hydrothermal vent system, Pele's Vents, located at Loihi Seamount, Hawaii. Oligonucleotides complementary to conserved regions in the 16S rRNA-encoding DNA (rDNA) of bacteria were used to direct the synthesis of PCR products, which were then subcloned by blunt-end ligation into phagemid vector pBluescript II. Restriction fragment length polymorphism patterns, created by using tandem tetrameric restriction endonucleases, revealed the presence of 12 groups of 16S rRNA genes representing discrete …


A Comparison Of No And N20 Production By The Autophic Nitrifier Nitrosomonas Europaea And The Heterotrophic Nitrifier Alcaligenes Faecalis, Iris C. Anderson, Mark Poth, Julie Homstead, David J. Burdige Nov 1993

A Comparison Of No And N20 Production By The Autophic Nitrifier Nitrosomonas Europaea And The Heterotrophic Nitrifier Alcaligenes Faecalis, Iris C. Anderson, Mark Poth, Julie Homstead, David J. Burdige

OES Faculty Publications

Soil microorganisms are important sources of the nitrogen trace gases NO and N2O for the atmosphere. Present evidence suggests that autotrophic nitrifiers such as Nitrosomonas europaea are the primary producers of NO and N2O in aerobic soils, whereas denitrifiers such as Pseudomonas spp. or Alcaligenes spp. are responsible for most of the NO and N2O emissions from anaerobic soils. It has been shown that Alcaligenes faecalis, a bacterium common in both soil and water, is capable of concomitant heterotrophic nitrification and denitrification. This study was undertaken to determine whether heterotrophic nitrification might be …


Preservation Of Atp In Hypersaline Environments, Bruce J. Tuovila, Fred C. Dobbs, Paul A. Larock, B. Z. Siegel Dec 1987

Preservation Of Atp In Hypersaline Environments, Bruce J. Tuovila, Fred C. Dobbs, Paul A. Larock, B. Z. Siegel

OES Faculty Publications

High concentrations of particulate ATP were found in the anoxic brines of the Orca Basin and East Flower Garden, Gulf of Mexico. Other measurements indicative of growth and respiration suggested that the microbial community in the brines was inactive, but somehow the ATP associated with the cells persisted. Conceivably, when cells growing just above the interface sank into the brine, the increased osmotic stress could elicit an osmoregulatory response resulting in increased ATP. It was also possible that hydrolytic enzymes were inactivated, resulting in the preservation of ATP. Experiments in which a culture of marine bacteria was suspended in menstrua …