# Analysis of microbial diversity of traditional Chinese starters and screening of special flavor yeast for Chinese baked flatbread

## TL;DR

This study identifies a special yeast from traditional Chinese starters that enhances the flavor of Chinese baked flatbread.

## Contribution

A novel yeast strain, Saccharomyces cerevisiae Y4, was isolated and shown to improve flavor and gas production in flatbread.

## Key findings

- Luohe starter had the highest fungal and bacterial richness with dominant genera Saccharomyces and Lactiplantibacillus.
- Saccharomyces cerevisiae Y4 produced 1975 mL gas and showed high ethanol and acid tolerance.
- Flour fermented with Y4 had a high sensory score and unique volatile compounds like 1-octen-3-ol and phenethyl acetate.

## Abstract

Traditional Chinese starters have unclear microbial complexity and community functions.

To screen functional yeasts for flavor enhancement of Chinese baked flatbread (CBF), Saccharomyces cerevisiae Y4 was isolated and identified from traditional Chinese starters using a combined approach of high-throughput sequencing and culturomics. The traditional starters samples were aseptically collected from Luohe, Xinxiang in Henan province and Rizhao in Shandong province.

The analysis of microbial communities revealed that Luohe starter had the highest fungal (Chao1 = 271.86) and bacterial (Chao1 = 341.76) richness, with dominant genera including Saccharomyces and Lactiplantibacillus. Saccharomyces cerevisiae Y4 showed the following performance: saturated gas production at 48 h, 12% ethanol tolerance, high acid tolerance (OD value below 0.15), and 1975 mL gas production in fermented dough. CBF fermented by Y4 had a high sensory score (82.8) and 40 volatiles, including the unique 1-octen-3-ol and a prominent level of phenethyl acetate content.

In this study, a superior yeast strain was identified, providing theoretical insights and valuable microbial resources for optimizing the flavor of CBF.