Bioelectroanalytical Detection of Lactic Acid Bacteria
Lactic acid bacteria (LAB) are an industrial important group of organisms that are notable for their inability to respire without growth supplements. Recently described bioelectroanalytical detectors that can specifically detect and enumerate microorganisms depend on a phenomenon known as extracellu...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-01-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/12/3/1257 |
| _version_ | 1827661645002833920 |
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| author | Evelina Jing Ying Han Lola Gonzalez Olias Stefan Wuertz Jamie Hinks |
| author_facet | Evelina Jing Ying Han Lola Gonzalez Olias Stefan Wuertz Jamie Hinks |
| author_sort | Evelina Jing Ying Han |
| collection | DOAJ |
| description | Lactic acid bacteria (LAB) are an industrial important group of organisms that are notable for their inability to respire without growth supplements. Recently described bioelectroanalytical detectors that can specifically detect and enumerate microorganisms depend on a phenomenon known as extracellular electron transport (EET) for effective detection. EET is often described as a type of microbial respiration, which logically excludes LAB from such a detection platform. However, members of the LAB have recently been described as electroactive with the ability to carry out EET, providing a timely impetus to revisit the utility of bioelectroanalytical detectors in LAB detection. Here, we show that an LAB, <i>Enterococcus faecalis</i>, is easily detected bioelectroanalytically using the defined substrate resorufin-β-<span style="font-variant: small-caps;">d</span>-galactopyranoside. Detection is rapid, ranging from 34 to 235 min for inoculum sizes between 10<sup>7</sup> and 10<sup>4</sup> CFU mL<sup>−1</sup>, respectively. We show that, although the signal achieved by <i>Enterococcus faecalis</i> is comparable to systems that rely on the respiratory EET strategies of target bacteria, <i>E. faecalis</i> is not dependent on the electrode for energy, and it is only necessary to capture small amounts of an organism’s metabolic energy to, in this case 1.6%, to achieve good detection. The results pave the way for new means of detecting an industrially important group of organisms, particularly in the food industry. |
| first_indexed | 2024-03-10T00:14:06Z |
| format | Article |
| id | doaj.art-7a14fa11e4e44200af0c75364eaf5303 |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-10T00:14:06Z |
| publishDate | 2022-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-7a14fa11e4e44200af0c75364eaf53032023-11-23T15:54:33ZengMDPI AGApplied Sciences2076-34172022-01-01123125710.3390/app12031257Bioelectroanalytical Detection of Lactic Acid BacteriaEvelina Jing Ying Han0Lola Gonzalez Olias1Stefan Wuertz2Jamie Hinks3Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, SingaporeCentre for Biosensors, Bioelectronics and Biodevices (C3Bio), Department of Chemical Engineering, University of Bath, Bath BA2 7AY, UKSingapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, SingaporeSingapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, SingaporeLactic acid bacteria (LAB) are an industrial important group of organisms that are notable for their inability to respire without growth supplements. Recently described bioelectroanalytical detectors that can specifically detect and enumerate microorganisms depend on a phenomenon known as extracellular electron transport (EET) for effective detection. EET is often described as a type of microbial respiration, which logically excludes LAB from such a detection platform. However, members of the LAB have recently been described as electroactive with the ability to carry out EET, providing a timely impetus to revisit the utility of bioelectroanalytical detectors in LAB detection. Here, we show that an LAB, <i>Enterococcus faecalis</i>, is easily detected bioelectroanalytically using the defined substrate resorufin-β-<span style="font-variant: small-caps;">d</span>-galactopyranoside. Detection is rapid, ranging from 34 to 235 min for inoculum sizes between 10<sup>7</sup> and 10<sup>4</sup> CFU mL<sup>−1</sup>, respectively. We show that, although the signal achieved by <i>Enterococcus faecalis</i> is comparable to systems that rely on the respiratory EET strategies of target bacteria, <i>E. faecalis</i> is not dependent on the electrode for energy, and it is only necessary to capture small amounts of an organism’s metabolic energy to, in this case 1.6%, to achieve good detection. The results pave the way for new means of detecting an industrially important group of organisms, particularly in the food industry.https://www.mdpi.com/2076-3417/12/3/1257lactic acid bacteriaextracellular electron transfermicrobial detection<i>E. faecalis</i>redox mediator |
| spellingShingle | Evelina Jing Ying Han Lola Gonzalez Olias Stefan Wuertz Jamie Hinks Bioelectroanalytical Detection of Lactic Acid Bacteria Applied Sciences lactic acid bacteria extracellular electron transfer microbial detection <i>E. faecalis</i> redox mediator |
| title | Bioelectroanalytical Detection of Lactic Acid Bacteria |
| title_full | Bioelectroanalytical Detection of Lactic Acid Bacteria |
| title_fullStr | Bioelectroanalytical Detection of Lactic Acid Bacteria |
| title_full_unstemmed | Bioelectroanalytical Detection of Lactic Acid Bacteria |
| title_short | Bioelectroanalytical Detection of Lactic Acid Bacteria |
| title_sort | bioelectroanalytical detection of lactic acid bacteria |
| topic | lactic acid bacteria extracellular electron transfer microbial detection <i>E. faecalis</i> redox mediator |
| url | https://www.mdpi.com/2076-3417/12/3/1257 |
| work_keys_str_mv | AT evelinajingyinghan bioelectroanalyticaldetectionoflacticacidbacteria AT lolagonzalezolias bioelectroanalyticaldetectionoflacticacidbacteria AT stefanwuertz bioelectroanalyticaldetectionoflacticacidbacteria AT jamiehinks bioelectroanalyticaldetectionoflacticacidbacteria |