Lactic acid bacteria population dynamics during minced beef storage under aerobic or modified atmosphere packaging conditions

Abstract

A total of 266 lactic acid bacteria (LAB) have been isolated from minced beef stored at 0, 5, 10 and 15 °C aerobically and under modified atmosphere packaging consisting of 40% CO(2)-30% O(2)-30% N(2) in the presence MAP (+) and absence MAP (-) of oregano essential oil. Sequencing of their 16S rRNA gene along with presence of the katA gene demonstrated dominance of the LAB microbiota by Leuconostoc spp. during aerobic storage at 5, 10 and 15 °C, as well as during MAP (-) and MAP (+) storage at 10 and 15 °C; Lactobacillus sakei prevailed during aerobic storage at 0 °C, as well as at MAP (-) and MAP (+) storage at 0 and 5 °C. The sporadic presence of other species such as Leuconostoc mesenteroides, Weisella viridescens, Lactobacillus casei and Lactobacillus curvatus has also been determined. Pulsed-Field Gel Electrophoresis of high molecular weight genomic DNA revealed the dynamics of the isolated LAB strains. Prevalence of Leuconostoc spp. was attributed to one strain only. On the other hand, packaging conditions affected Lb. sakei strain spoilage dynamics.

Differential Biofilm Formation and Chemical Disinfection Resistance of Sessile Cells of Listeria monocytogenes Strains under Monospecies and Dual-Species (with Salmonella enterica) Conditions

“…This was something quite expected, given the well-known greater capability of L. monocytogenes to adapt to survive and grow under a wider range of environmental conditions than S. enterica (18). In order to discriminate between the three different L. monocytogenes strains with regard to their ability to contribute to the formation and maintenance of the mixed culture biofilm communities (mono-/dual species) as well as to their antimicrobial recalcitrance, a promising PFGE approach, already used by our team (15,34), was followed. In this study, PFGE analysis revealed interesting information regarding strain occurrence following the different treatments (control, BC, NaClO, PA, and HP-PA) (Fig.…”

Lactic acid bacteria and yeast heterogeneity during aerobic and modified atmosphere packaging storage of natural black Conservolea olives in polyethylene pouches

“…The rest isolates were subjected to species identification by sequencing the V1-V3 variable region of the 16S rRNA gene with the primer PI-V1 (Doulgeraki, Paramithiotis, Kagkli, & Nychas, 2010). PCR products were purified using the QIAquick Ò PCR Purification Kit (Qiagen, Hilden, Germany) according to the manufacturer's instructions and directly sequenced by the Department of Immunology & Histocompatibility, School of Medicine, University of Thessaly (Larissa, Greece).…”

Processing Environment and Ingredients Are Both Sources of Leuconostoc gelidum, Which Emerges as a Major Spoiler in Ready-To-Eat Meals

“…Currently, the focus is mainly on the systematic study of wellknown spoilage-related species (13)(14)(15)(16)(17)(18) in various food matrices and the development of methods to suppress their growth and offensive metabolism through the application of innovative technologies. The spoilage-related populations can be studied as a consortium with the help of culture-independent approaches in order to look at changes to the composition of the microbial communities in response to environmental factors related to food storage, such as temperature and packaging technology (19,20), as well as technological parameters (21).…”