Flow Cytometric Assessment of Lactococcus Lactis Isolates Viability after Lyophilization

Leandro, Eliana dos Santos

doi:10.11648/j.ijnfs.20140305.15

Cited by 6 publications

(2 citation statements)

References 25 publications

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“…Regarding the concentration of NH 3 -N, the lowest values were observed in silage treated with Streptococcus bovis JB1 and HC5, and this reduction may have occurred due to ammonia intake, a characteristic of Streptococcus bovis as reported by Cezário et al [4] and Mantovani et al [5], or the inhibition of the proteolytic organisms due to pH reduction [16]. According to Leandro [22], a greater concentration of NH 3 -N indicates more intense proteolysis, mainly because the amino acids are fermented by the proteolytic clostridia through valine and leucine deamination and the redox reaction between alanine and glycine. For this silage to be considered of being satisfactory, acceptable, or low quality, the concentration of NH 3 -N should be lower than 10%, between 10 and 15%, and over 20% of total N, respectively [3].…”

Section: Resultsmentioning

confidence: 99%

Effects ofStreptococcus bovisIsolated from Bovine Rumen on the Fermentation Characteristics and Nutritive Value of Tanzania Grass Silage

Zanine

Bonelli

Souza

et al. 2016

The Scientific World Journal

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This study aimed to evaluate the effects of Streptococcus bovis on the fermentation characteristics and nutritive value of Tanzania grass silage. Tanzania grass was chopped and left untreated (U) or treated with Streptococcus bovis JB1 at 1 × 106 colony-forming units per gram (cfu/g) of fresh forage or Streptococcus bovis HC5 at 1 × 106 cfu/g of fresh forage and packed into sixtuplicate laboratory silos. The largest number of enterobacteria, molds and yeast (M&Y) occurred in untreated silages and the smallest populations of enterobacteria and M&Y and the largest numbers of lactic acid bacteria (LAB), at 9.81 and 9.87 log cfu/g, were observed in Streptococcus bovis JB1 and HC5, respectively (P < 0.05). Silages treated with JB1 and HC5 had lower (P < 0.05) silage pHs and concentrations of ammoniacal nitrogen (NH3-N) than untreated silages. The application of Streptococcus bovis JB1 and HC5 resulted in fewer losses through gases and effluents (P < 0.05), which resulted in greater dry matter recovery (DMR) and crude protein recovery (CPR) (P < 0.05). Streptococcus bovis JB1 and HC5 improved the fermentative profile and increased the concentration of crude protein and DMR and CPR in Tanzania grass silage.

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Section: Resultsmentioning

confidence: 99%

Effects ofStreptococcus bovisIsolated from Bovine Rumen on the Fermentation Characteristics and Nutritive Value of Tanzania Grass Silage

Zanine

Bonelli

Souza

et al. 2016

The Scientific World Journal

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“…EFM is commonly used in the study of the physiological state of bacterial cells. Various parameters of the physiological state of bacterial cells can be labeled, depending on the used indicators [ 16 ]. These indicators are fluorescent dyes, known as fluorochromes or fluorophores [ 17 ].…”

Section: Introductionmentioning

confidence: 99%

High-Pressure-Induced Sublethal Injuries of Food Pathogens—Microscopic Assessment

Nasiłowska

Kocot

Osuchowska

et al. 2021

Foods

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High Hydrostatic Pressure (HHP) technology is considered an alternative method of food preservation. Nevertheless, the current dogma is that HHP might be insufficient to preserve food lastingly against some pathogens. Incompletely damaged cells can resuscitate under favorable conditions, and they may proliferate in food during storage. This study was undertaken to characterize the extent of sublethal injuries induced by HHP (300–500 MPa) on Escherichia coli and Listeria inncua strains. The morphological changes were evaluated using microscopy methods such as Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Epifluorescence Microscopy (EFM). The overall assessment of the physiological state of tested bacteria through TEM and SEM showed that the action of pressure on the structure of the bacterial membrane was almost minor or unnoticeable, beyond the L. innocua wild-type strain. However, alterations were observed in subcellular structures such as the cytoplasm and nucleoid for both L. innocua and E. coli strains. More significant changes after the HHP of internal structures were reported in the case of wild-type strains isolated from raw juice. Extreme condensation of the cytoplasm was observed, while the outline of cells was intact. The percentage ratio between alive and injured cells in the population was assessed by fluorescent microscopy. The results of HHP-treated samples showed a heterogeneous population, and red cell aggregates were observed. The percentage ratio of live and dead cells (L/D) in the L. innocua collection strain population was higher than in the case of the wild-type strain (69%/31% and 55%/45%, respectively). In turn, E. coli populations were characterized with a similar L/D ratio. Half of the cells in the populations were distinguished as visibly fluorescing red. The results obtained in this study confirmed sublethal HHP reaction on pathogens cells.

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Enumeration and Identification of Mixed Probiotic and Lactic Acid Bacteria Starter Cultures

Majhenič¹,

Lorbeg²,

Treven³

2017

Probiotic Dairy Products

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Flow Cytometric Assessment of Lactococcus Lactis Isolates Viability after Lyophilization

Cited by 6 publications

References 25 publications

Effects ofStreptococcus bovisIsolated from Bovine Rumen on the Fermentation Characteristics and Nutritive Value of Tanzania Grass Silage

Effects ofStreptococcus bovisIsolated from Bovine Rumen on the Fermentation Characteristics and Nutritive Value of Tanzania Grass Silage

High-Pressure-Induced Sublethal Injuries of Food Pathogens—Microscopic Assessment

Enumeration and Identification of Mixed Probiotic and Lactic Acid Bacteria Starter Cultures

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