Diversity and Stability of Lactic Acid Bacteria in Rye Sourdoughs of Four Bakeries with Different Propagation Parameters

PLoS One. 2016 Feb 5;11(2):e0148325. doi: 10.1371/journal.pone.0148325. eCollection 2016.

Abstract

We identified the lactic acid bacteria within rye sourdoughs and starters from four bakeries with different propagation parameters and tracked their dynamics for between 5-28 months after renewal. Evaluation of bacterial communities was performed using plating, denaturing gradient gel electrophoresis, and pyrosequencing of 16S rRNA gene amplicons. Lactobacillus amylovorus and Lactobacillus frumenti or Lactobacillus helveticus, Lactobacillus pontis and Lactobacillus panis prevailed in sourdoughs propagated at higher temperature, while ambient temperature combined with a short fermentation cycle selected for Lactobacillus sanfranciscensis, Lactobacillus pontis, and Lactobacillus zymae or Lactobacillus helveticus, Lactobacillus pontis and Lactobacillus zymae. The ratio of species in bakeries employing room-temperature propagation displayed a seasonal dependence. Introduction of different and controlled propagation parameters at one bakery (higher fermentation temperature, reduced inoculum size, and extended fermentation time) resulted in stabilization of the microbial community with an increased proportion of L. helveticus and L. pontis. Despite these new propagation parameters no new species were detected.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biodiversity
  • Bread / microbiology*
  • Candida / genetics
  • Candida / isolation & purification
  • Estonia
  • Fermentation
  • Food Industry
  • Food Microbiology / methods*
  • Lactic Acid / metabolism
  • Lactobacillus / genetics*
  • Microbial Consortia / genetics*
  • RNA, Ribosomal, 16S
  • Saccharomycetales / genetics
  • Saccharomycetales / isolation & purification
  • Secale*

Substances

  • RNA, Ribosomal, 16S
  • Lactic Acid

Grants and funding

Financial support was provided by the European Regional Development Fund (http://www.struktuurifondid.ee/euroopa-regionaalarengu-fond/) project EU29994 (EV, MB, TT, IS) together with funds from Estonian Research Council (http://www.etag.ee/rahastamine/etf-grandid/) research grant ETF9417 (IS), Ministry of Education and Research (http://www.etag.ee/rahastamine/institutsionaalne-uurimistoetus/) research grant IUT19-27 (TP, IS) and the European Social Fund Doctoral Studies and Internationalization Programme DoRa (http://adm.archimedes.ee/stipendiumid/programm-dora/) administered by SA Archimedes (EV, MB). This work has been partially supported by graduate school „Functional materials and technologies“ receiving funding from the European Social Fund (http://www.struktuurifondid.ee/euroopa-sotsiaalfond-2/) under project 1.2.0401.09-0079 in Estonia (EV). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.