An Alternative Approach to “Identification of Unknowns”: Designing a Protocol to Verify the Identities of Nitrogen Fixing Bacteria

Microbiology courses often include a laboratory activity on the identification of unknown microbes. This activity consists of providing students with microbial cultures and running biochemical assays to identify the organisms. This approach lacks molecular techniques such as sequencing of genes enco...

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Autores principales:	Betsy M. Martinez-Vaz, Roxanne Denny, Nevin D. Young, Michael J. Sadowsky
Formato:	article
Lenguaje:	EN
Publicado:	American Society for Microbiology 2015
Materias:	Special aspects of education LC8-6691 Biology (General) QH301-705.5
Acceso en línea:	https://doaj.org/article/97e54c4e8b8a4b078c2ce11b425496ea
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spelling	oai:doaj.org-article:97e54c4e8b8a4b078c2ce11b425496ea2021-11-15T15:04:04ZAn Alternative Approach to “Identification of Unknowns”: Designing a Protocol to Verify the Identities of Nitrogen Fixing Bacteria10.1128/jmbe.v16i2.9731935-78851935-7877https://doaj.org/article/97e54c4e8b8a4b078c2ce11b425496ea2015-12-01T00:00:00Zhttps://journals.asm.org/doi/10.1128/jmbe.v16i2.973https://doaj.org/toc/1935-7877https://doaj.org/toc/1935-7885Microbiology courses often include a laboratory activity on the identification of unknown microbes. This activity consists of providing students with microbial cultures and running biochemical assays to identify the organisms. This approach lacks molecular techniques such as sequencing of genes encoding 16S rRNA, which is currently the method of choice for identification of unknown bacteria. A laboratory activity was developed to teach students how to identify microorganisms using 16S rRNA polymerase chain reaction (PCR) and validate microbial identities using biochemical techniques. We hypothesized that designing an experimental protocol to confirm the identity of a bacterium would improve students’ knowledge of microbial identification techniques and the physiological characteristics of bacterial species. Nitrogen-fixing bacteria were isolated from the root nodules of Medicago truncatula and prepared for 16S rRNA PCR analysis. Once DNA sequencing revealed the identity of the organisms, the students designed experimental protocols to verify the identity of rhizobia. An assessment was conducted by analyzing pre- and posttest scores and by grading students’ verification protocols and presentations. Posttest scores were higher than pretest scores at or below p = 0.001. Normalized learning gains (G) showed an improvement of students’ knowledge of microbial identification methods (LO4, G = 0.46), biochemical properties of nitrogen-fixing bacteria (LO3, G = 0.45), and the events leading to the establishment of nitrogen-fixing symbioses (LO1&2, G = 0.51, G = 0.37). An evaluation of verification protocols also showed significant improvement with a p value of less than 0.001.Betsy M. Martinez-VazRoxanne DennyNevin D. YoungMichael J. SadowskyAmerican Society for MicrobiologyarticleSpecial aspects of educationLC8-6691Biology (General)QH301-705.5ENJournal of Microbiology & Biology Education, Vol 16, Iss 2, Pp 247-253 (2015)
institution	DOAJ
collection	DOAJ
language	EN
topic	Special aspects of education LC8-6691 Biology (General) QH301-705.5
spellingShingle	Special aspects of education LC8-6691 Biology (General) QH301-705.5 Betsy M. Martinez-Vaz Roxanne Denny Nevin D. Young Michael J. Sadowsky An Alternative Approach to “Identification of Unknowns”: Designing a Protocol to Verify the Identities of Nitrogen Fixing Bacteria
description	Microbiology courses often include a laboratory activity on the identification of unknown microbes. This activity consists of providing students with microbial cultures and running biochemical assays to identify the organisms. This approach lacks molecular techniques such as sequencing of genes encoding 16S rRNA, which is currently the method of choice for identification of unknown bacteria. A laboratory activity was developed to teach students how to identify microorganisms using 16S rRNA polymerase chain reaction (PCR) and validate microbial identities using biochemical techniques. We hypothesized that designing an experimental protocol to confirm the identity of a bacterium would improve students’ knowledge of microbial identification techniques and the physiological characteristics of bacterial species. Nitrogen-fixing bacteria were isolated from the root nodules of Medicago truncatula and prepared for 16S rRNA PCR analysis. Once DNA sequencing revealed the identity of the organisms, the students designed experimental protocols to verify the identity of rhizobia. An assessment was conducted by analyzing pre- and posttest scores and by grading students’ verification protocols and presentations. Posttest scores were higher than pretest scores at or below p = 0.001. Normalized learning gains (G) showed an improvement of students’ knowledge of microbial identification methods (LO4, G = 0.46), biochemical properties of nitrogen-fixing bacteria (LO3, G = 0.45), and the events leading to the establishment of nitrogen-fixing symbioses (LO1&2, G = 0.51, G = 0.37). An evaluation of verification protocols also showed significant improvement with a p value of less than 0.001.
format	article
author	Betsy M. Martinez-Vaz Roxanne Denny Nevin D. Young Michael J. Sadowsky
author_facet	Betsy M. Martinez-Vaz Roxanne Denny Nevin D. Young Michael J. Sadowsky
author_sort	Betsy M. Martinez-Vaz
title	An Alternative Approach to “Identification of Unknowns”: Designing a Protocol to Verify the Identities of Nitrogen Fixing Bacteria
title_short	An Alternative Approach to “Identification of Unknowns”: Designing a Protocol to Verify the Identities of Nitrogen Fixing Bacteria
title_full	An Alternative Approach to “Identification of Unknowns”: Designing a Protocol to Verify the Identities of Nitrogen Fixing Bacteria
title_fullStr	An Alternative Approach to “Identification of Unknowns”: Designing a Protocol to Verify the Identities of Nitrogen Fixing Bacteria
title_full_unstemmed	An Alternative Approach to “Identification of Unknowns”: Designing a Protocol to Verify the Identities of Nitrogen Fixing Bacteria
title_sort	alternative approach to “identification of unknowns”: designing a protocol to verify the identities of nitrogen fixing bacteria
publisher	American Society for Microbiology
publishDate	2015
url	https://doaj.org/article/97e54c4e8b8a4b078c2ce11b425496ea
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An Alternative Approach to “Identification of Unknowns”: Designing a Protocol to Verify the Identities of Nitrogen Fixing Bacteria

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