Rapid monitoring of sourdough starter and contaminants using a dual-lateral flow immunochromatographic assay.

Authors

Sanae Konami, Kyoka Aiki, Tatsuya Tominaga

Published in

Journal of microbiological methods. Pages 107706. Sep 12, 2026. Epub Sep 12, 2026.

Abstract

Sourdough maintenance via daily backslopping faces the persistent risk of starter lactic acid bacteria (LAB) being displaced by competing contaminants. Here, we developed a dual-lateral flow immunochromatographic assay (LFIA) system to simultaneously monitor starter health (Fructilactobacillus sanfranciscensis; Fsanf-LFIA) and contaminant presence (Pediococcus acidilactici; Ped-LFIA). Fsanf-LFIA and Ped-LFIA both exhibited detection limits of 5 log cells/test. Fsanf-LFIA was highly specific to certain strains of F. sanfranciscensis, whereas Ped-LFIA demonstrated a broader detection spectrum, cross-reacting with P. pentosaceus, other LAB (excluding F. sanfranciscensis), Bacillus, and Staphylococcus species. To evaluate practical on-site utility, sourdoughs inoculated with F. sanfranciscensis (9 log cells/g) and P. acidilactici (2 log cells/g) were maintained via daily backslopping at 23 °C, 30 °C, and 37 °C for 4 days. On day 4, conventional monitoring parameters failed to capture any change in sourdough grown at 37 °C, as pH levels dropped below 4.5 and total LAB counts remained virtually identical across all temperatures. However, while Fsanf-LFIA remained positive across all temperatures, Ped-LFIA turned positive exclusively at 37 °C. Amplicon sequencing validated these results, revealing that the abundance of F. sanfranciscensis plummeted to 6.2% at 37 °C, and Pediococcus became the dominant taxon. These findings demonstrate that the developed dual-LFIA system, which requires no specialized equipment, can quickly (within 1 h) detect early microbial displacement via visual-inspection-based binary judgment. This user-friendly system holds strong promise as a versatile quality-control tool for both industrial and artisanal sourdough-manufacturing facilities.

PMID:
42731707
Bibliographic data and abstract were imported from PubMed on 13 Sep 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.