Transcriptome response of<i>Lactobacillus sakei</i>to meat protein environment

Xu, Huiqing; Yun-shen, Jiang; Tian, Ying; Peng, Jin; Xa, Qi-quan; Chen, Yu

doi:10.1002/jobm.201400540

Cited by 8 publications

(4 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Different efficiency in the utilization of arginine were also observed in two L. sakei strains (23K and LS25) grown in glucose limited medium; these differences were explained by the possible presence of two distinct ADI pathways, whose coexistence favored a more efficient arginine metabolism (McLeod et al, 2017). According to previous study, the ADI pathway was inhibited by low pH (Rimaux et al, 2011a; Xu et al, 2015). This trend was confirmed by the fact that higher arginine depletion was observed when sugars were not added, and, thus, when the medium was not acidified by microbial metabolisms of simple carbohydrates.…”

Section: Resultsmentioning

confidence: 85%

Phenotypic Diversity of Lactobacillus sakei Strains

et al. 2018

View full text Add to dashboard Cite

Lactobacillus sakei is a lactic acid bacteria (LAB) species highly adapted to the meat environment. For this reason, selected strains are often used as starter culture in the production of fermented sausages, especially in Mediterranean countries. It often represents the dominant species in these products and can maintain its viability during all the ripening period, which can take also some months. This ability is guaranteed by the possibility of the species to obtain energy through pathways active even when hexoses are depleted. This species is characterized by a relevant genetic and phenotypic diversity and its metabolism can be further affected by the growth condition applied. In this work we investigate the metabolic responses of six different L. sakei in a synthetic medium (DM) containing defined amounts of amino acids in relation to temperature and NaCl concentration. In addition, the activities of cells pre-grown in presence of glucose o ribose were tested. Arginine was efficiently up-taken with the exception of the type strain DSMZ 20017t. Other amino acids (i.e., serine, asparagine, cysteine, and methionine) were metabolized through potentially energetic pathways which start from pyruvate accumulation, as demonstrated by the organic acid accumulation trend in the condition tested, especially in DM without sugar added. The presence of excesses of pyruvate deriving from amino acids lead to the accumulation of diacetyl and acetoin by all the strains when sugars were added. This approach allowed a deeper insight into the phenotypic variability of the species and improved the comprehension of the metabolic pathways adopted by L. sakei to survive and grow in restrictive conditions such as those found in fermented sausages during fermentations. Thus, the results obtained are useful information for improving and optimizing the use of such strains as starter culture for these products.

show abstract

Section: Resultsmentioning

confidence: 85%

Phenotypic Diversity of Lactobacillus sakei Strains

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Moreover, even though we found a high presence of this molecule at the end of ripening in I samples (1,100 g/kg, Table S4), Dainty et al (27) have reported that the higher presence of acetoin in meat is not unpleasant. Carbohydrate metabolism was the most prevalent pathway in I samples, most likely due to the predominant presence of the heterofermentative L. sakei (28), and carbohydrate pathways were found to be one of the main precursors of many volatile organic compounds (VOCs) such as acetate, acetoin, diacetyl, acetic acid, and isobutyric acid (1).…”

mentioning

confidence: 99%

Shotgun Metagenomics and Volatilome Profile of the Microbiota of Fermented Sausages

Ferrocino

Bellio

Giordano

et al. 2018

Appl Environ Microbiol

View full text Add to dashboard Cite

Changes in the microbial gene content and abundance can be analyzed to detect shifts in the microbiota composition due to the use of a starter culture in the food fermentation process, with the consequent shift of key metabolic pathways directly connected with product acceptance. Meat fermentation is a complex process involving microbes that metabolize the main components in meat. The breakdown of carbohydrates, proteins, and lipids can lead to the formation of volatile organic compounds (VOCs) that can drastically affect the organoleptic characteristics of the final products. The present meta-analysis, performed with the shotgun DNA metagenomic approach, focuses on studying the microbiota and its gene content in an Italian fermented sausage produced by using a commercial starter culture (a mix of and), with the aim to discover the connections between the microbiota, microbiome, and the release of volatile metabolites during ripening. The inoculated fermentation with the starter culture limited the development of and reduced the microbial diversity compared to that from spontaneous fermentation. KEGG database genes associated with the reduction of acetaldehyde to ethanol (EC 1.1.1.1), acetyl phosphate to acetate (EC 2.7.2.1), and 2,3-butanediol to acetoin (EC 1.1.1.4) were most abundant in inoculated samples (I) compared to those in spontaneous fermentation samples (S). The volatilome profiles were highly consistent with the abundance of the genes; elevated acetic acid (1,173.85 μg/kg), ethyl acetate (251.58 μg/kg), and acetoin (1,100.19 μg/kg) were observed in the presence of the starters at the end of fermentation. Significant differences were found in the liking of samples based on flavor and odor, suggesting a higher preference by consumers for the spontaneous fermentation samples. Inoculated samples exhibited the lowest scores for the liking data, which were clearly associated with the highest concentration of acetic acid. We present an advance in the understanding of meat fermentation by coupling DNA sequencing metagenomics and metabolomics approaches to describe the microbial function during this process. Very few studies using this global approach have been dedicated to food, and none have examined sausage fermentation, underlying the originality of the study. The starter culture drastically affected the organoleptic properties of the products. This finding underlines the importance of starter culture selection that takes into consideration the functional characteristics of the microorganism to optimize production efficiency and product quality.

show abstract

“…Primers were designed and synthesized according to gene sequences on NCBI (Table S1 ). The gene‐expression levels were calculated via the 2 —△△Ct method (Xu et al., 2015 ), which was used to compare with the sequencing results of the transcriptome.…”

Section: Methodsmentioning

confidence: 99%