Recovery of Lactic Acid Bacteria on Petrifilm™ SM Under Various Incubation Atmospheres1

1995 ◽  
Vol 58 (3) ◽  
pp. 316-318 ◽  
Author(s):  
JOHN U. McGREGOR ◽  
SANDRA M. TRAYLOR ◽  
RONALD H. GOUGH ◽  
STEPHANIE HAZLETT ◽  
KENNY BIRD
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactococcus Lactis ◽  
Streptococcus Thermophilus ◽  
Lactobacillus Bulgaricus ◽  
Oxygen Environment ◽  
Lactococcus Lactis Subsp ◽  
Frozen Yogurt ◽  
Co2 Environment ◽  
Better Than

The ability of lactic cultures to grow on Petrifilm™ SM plates was studied. Frozen yogurt mix was analyzed microbiologically by plating on TOE, LBS, M17 and Petrifilm™ SM. Plates were incubated aerobically in a Gas-Pak System and under a CO2 environment. Also, Lactobacillus bulgaricus, Streptococcus thermophilus, Lactococcus lactis subsp. diacetylactis, and Leuconostoc cremoris were isolated from yogurt and buttermilk samples for study. Isolated cultures were grown in nutrient broth and plated on Petrifilm™ SM and M17 agar. Plates were incubated aerobically and in a Gas-Pak system. Petrifilm™ SM plates performed as well or better than the M17 agar in assaying lactic growth with the exception of Streptococcus thermophilus culture in an aerobic environment. Petrifilm™ SM plates show promise as a method for enumerating viable lactic cultures if incubated in a reduced oxygen environment.

scholarly journals Metabolic Response of Faecalibacterium prausnitzii to Cell-Free Supernatants from Lactic Acid Bacteria

2020 ◽  
Vol 8 (10) ◽  
pp. 1528
Author(s):  
Mathilde Lebas ◽  
Peggy Garault ◽  
Daniel Carrillo ◽  
Francisco M. Codoñer ◽  
Muriel Derrien
Keyword(s):  
Cell Wall ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Gut Microbiota ◽  
Lactococcus Lactis ◽  
Dietary Intervention ◽  
Metabolic Response ◽  
Streptococcus Thermophilus ◽  
Lactococcus Lactis Subsp ◽  
Faecalibacterium Prausnitzii

Interest in preventive or therapeutic strategies targeting gut microbiota is increasing. Such strategies may involve the direct replenishment of the gut microbiota with single strains or strain mixtures, or the manipulation of strain abundance through dietary intervention, including lactic acid bacteria. A few candidate species associated with health benefits have been identified, including Faecalibacterium prausnitzii. Given its growth requirements, modulation of this bacterium has not been extensively studied. In this investigation, we explored the capacity of cell-free supernatants of different Lactobacillus, Streptococcus, Lactococcus, and Bifidobacterium strains to stimulate the growth of F. prausnitzii A2-165. Modulation by four strains with the greatest capacity to stimulate growth or delay lysis, Lactococcus lactis subsp. lactis CNCM I-1631, Lactococcus lactis subsp. cremoris CNCM I-3558, Lactobacillus paracasei CNCM I-3689, and Streptococcus thermophilus CNCM I-3862, was further characterized by transcriptomics. The response of F. prausnitzii to cell-free supernatants from these four strains revealed several shared characteristics, in particular, upregulation of carbohydrate metabolism and cell wall-related genes and downregulation of replication and mobilome genes. Overall, this study suggests differential responses of F. prausnitzii to metabolites produced by different strains, providing protection against cell death, with an increase in peptidoglycan levels for cell wall formation, and reduced cell mobilome activity.

scholarly journals EFFECT OF EXOPOLISACCHARIDES OF LACTIC ACID BACTERIA ON THE SYNTHESIS OF PROINFLAMMATORY CYTOKINES BY MACROPHAGIC MICE IN PHAGOCYTOSIS OF STAPHYLOCOCCUS AUREUS

2018 ◽  
pp. 67-71
Author(s):  
G. T. Uryadova ◽  
E. A. Gorelnikova ◽  
N. A. Fokina ◽  
A. S. Dolmashkina ◽  
L. V. Karpunina
Keyword(s):  
Staphylococcus Aureus ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactococcus Lactis ◽  
Inflammatory Cytokines ◽  
Proinflammatory Cytokines ◽  
Streptococcus Thermophilus ◽  
Ambiguous Effect ◽  
Pro Inflammatory Cytokines

Aim. Study of the effect of exopolysaccharides (EPS) of lactic acid cocci on cytokine activity of macrophages of mice with phagocytosis in vitro Staphylococcus aureus 209-P. Materials and methods. The EPS of Streptococcus thermophilus and Lactococcus lactis B-1662 was used in the work. At 13, 5 and 7, AMP and PMP were isolated and the phagocytosis process was modeled in vitro. After 30 minutes, 1, 6 and 24 hours, the content of pro-inflammatory cytokines IL-1a and TNF-a was determined. Results. EPSs had an ambiguous effect on the production of cytokines. The greatest effect on the synthesis was provided by EPS of S. thermophilus. Conclusion. The results of the study allow us to talk about the possibility of using EPS of S. thermophilus as a preventive immunomodulator for correction of the cytokine status of animals.

scholarly journals Importância das Bactérias Ácido Láticas e não Starter (NSLAB) na Tecnologia de Produção dos Derivados Lácteos

2020 ◽  
Vol 24 (4) ◽  
pp. 348-352
Author(s):  
Maria Tereza Pereira ◽  
Elsa Helena Walter de Santana ◽  
Joice Sifuentes dos Santos
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactococcus Lactis ◽  
Lactobacillus Casei ◽  
Streptococcus Thermophilus ◽  
Raw Milk ◽  
Fermented Milk ◽  
Starter Cultures ◽  
Bacillus Spp ◽  
Lactobacillus Spp

Produtos lácteos fermentados contêm bactérias ácido lácticas (BAL), naturalmente presentes ou adicionadas na matriz láctea como culturas iniciadoras (starters), contribuindo com aroma, textura, valor nutricional e segurança microbiológica. Lactobacillus spp., Streptococcus spp., Lactococcus spp. e Leuconostoc spp. são utilizados como culturas starters em laticínios. As BAL podem ser classificadas em mesofílicas (ex Lactococcus lactis) e termofílicas (ex Streptococcus thermophilus), e de acordo com seus metabólitos de fermentação em homofermentativas (ácido lático) e heterofermentativas (ácido lático, dióxido de carbono, diacetil e outros compostos flavorizantes). Entre as BAL há um grupo de bactérias lácticas que não fazem parte da cultura láctica (non starter lactic acid bacteria - NSLAB), que são oriundas do leite cru, do ambiente de ordenha ou da indústria formando biofilmes. As NSLAB são representadas por espécies heterofermentativas de lactobacilos mesofílicos como Lactobacillus casei spp., L. paracasei spp., L. rhamnosus spp. e L. plantarum spp., e ainda por Pediococcus spp., Leuconostoc spp. e Micrococcus spp. NSLAB termoduricas como Bacillus spp. também são relatadas. As NSLAB em queijos podem ajudar a desenvolver sabor e aroma, porém também são associadas aos defeitos em queijos e leites fermentados. Problemas como odores estranhos, sabor amargo ou muito ácido, perda de viscosidade, perda de coloração, estufamento e formação de gás são associados com a presença e contaminação por NSLAB. Assim, as BAL são importantes micro-organismos na indústria láctea, garantindo sabores e aromas aos derivados. Já a presença de NSLAB podem ser associados com defeitos em queijos e leites fermentados, sendo um problema na indústria beneficiadora.   Palavras-chave: Característica Sensorial. Leites Fermentados. Queijo. Textura.                       Abstract Fermented dairy products contain acid bacteria (BAL) naturally present or added to the dairy matrix as starter cultures (starters), contributing to aroma, texture, nutritional value and microbiological safety. Lactobacillus spp., Streptococcus spp., Lactococcus spp. and Leuconostoc spp. are used as starter dairy crops. As BAL it can be classified as mesophilic (ex: Lactococcus lactis) and thermophilic (ex: Streptococcus thermophilus), and agree with its fermentation metabolites in homofermentative (lactic acid) and heterofermentative (lactic acid, carbon dioxide, diacetyl and other flavorings). Among the BAL, there is a group of lactic bacteria that are not part of the dairy culture (non-initiating lactic acid bacteria - NSLAB) that originate from raw milk, the milking environment or the biofilm-forming industry. NSLAB is represented by heterofermentative species of mesophilic lactobacilli such as Lactobacillus casei spp., L. paracasei spp., L. rhamnosus spp. and L. plantarum spp., and also by Pediococcus spp., Leuconostoc spp. and Micrococcus spp. Termoduric NSLAB such as Bacillus spp. are also related. NSLAB in cheeses may help develop flavor and aroma, and they are also associated with defects in fermented cheeses and milks. Problems such as strange odors, bitter or very acidic taste, loss of viscosity, loss of color, establishment and gas training are associated with the presence and contamination by NSLAB. Thus,  BALs are important microorganisms in the dairy industry, contributing to the dairy flavors and aromas. The presence of NSLAB, on the other hand, can be associated with defects in fermented milk and cheese, being a problem in the processing industry.   Keywords: Cheese. Fermented Milk. Sensory Characteristic. Texture.

scholarly journals Film coatings based on exopolysaccharides of lactic acid bacteria and their use

2020 ◽  
Author(s):  
G. T. Uryadova ◽  
N. A. Fokina ◽  
L. V. Karpunina
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactococcus Lactis ◽  
Streptococcus Thermophilus ◽  
Film Coatings

It is shown that film coatings based on the exopolysaccharides of lactic acid bacteria Lactococcus lactis B-1662 and Streptococcus thermophilus contribute to the healing of burns in rats.

scholarly journals Identifying the Diversity of Dominant LABs from Fermented Dairy Products Dahi and Yoghurt in Eastern Region of Nepal

2019 ◽  
Vol 11 ◽  
pp. 60-64
Author(s):  
Sanjay Mahato ◽  
Aakash Kumar Shahani
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Streptococcus Thermophilus ◽  
Lactobacillus Bulgaricus ◽  
Eastern Region ◽  
Isolation And Identification ◽  
Carbohydrate Utilization ◽  
Variable Nature ◽  
Microbiological Techniques ◽  
Fermented Dairy

The aim of this study was to isolate and identify lactic acid bacteria diversity from dahi/ yoghurt. Curd, also known as commercially prepared yoghurt or homemade Dahi, is formed during the slow lactic fermentation of lactose from milk by thermophilic lactic acid bacteria (LAB). Thirty-five samples of yoghurt and curd were collected from the Biratnagar and isolation and identification of bacteria were done by various microbiological techniques like MRS Agar inoculation, colony characteristics, microscopic and biochemical examination. A total of sixty-six strains of lactobacilli were isolated from curd and identification of strains was done by biochemical and carbohydrate utilization test. Lactobacillus bulgaricus, L. casei, L. fermentum, L. acidophilus, and Streptococcus thermophilus were identified from curd. pH of samples was between 3.0 to 4.0 for homemade dahi; while 4.34 to 4.5 for commercially available yoghurt. The mean colony count of lactic acid bacteria was 1.4x107–4.9x107 cfu/g. 37.9% of samples contained Streptococcus thermophilus, 30.3% had Lactobacillus bulgaricus. Forty-five isolates from 24 industrial yoghurt samples showed 37.5% of the yoghurt contained both Lactobacillus bulgaricus and Streptococcus thermophilus followed by 25% samples having S. thermophilus and L. acidophilus. Other species like L. fermentum and L. casei were less common. From 11 homemade dahi samples, 54.5% of curd possessed both S. thermophilus and L. bulgaricus; 18.2% curd had both S. thermophilus and L. fermentum. The study concludes that L. bulgaricus and Streptococcus thermophilus are prevalent potent lactic acid bacteria. This study provides an account of the diversity of lactic acid bacteria in dahi/ yoghurt which will provide useful information about the variable nature of curd in this region to future researchers.

Utilization of Lesser Yam (Dioscorea esculenta L.) Flour as Prebiotic in Yogurt to Total Lactic Acid Bacteria (LAB), Sugar Reduction, and Organoleptic Properties

2020 ◽  
Vol 2 ◽  
pp. 00011
Author(s):  
Yoyok Budi Pramono ◽  
Nurwantoro Bambang Dwiloka ◽  
Sri Mulyani ◽  
Bhakti Etza Setiani ◽  
Maulida Rochmayani ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Raw Materials ◽  
Sugar Content ◽  
Streptococcus Thermophilus ◽  
Lactobacillus Bulgaricus ◽  
Crude Fiber ◽  
Organoleptic Properties ◽  
Randomized Design ◽  
Sugar Reduction

This study aims to determine the effect of the concentration the addition of lesser yam as prebiotic to total Lactic Acid Bacteria (LAB), reducing sugar content, crude fiber, viscosity, and organoleptic properties of yogurt with a combination of three bacteria (Streptococcus thermophilus, Lactobacillus bulgaricus, and Lactobacillus acidophilus). The design of this study used a completely randomized design (CRD) with 4 treatments and 5 replications with variations in the addition of lesser yam tuber, namely T1 with a concentration of 0%, T2 with a concentration of 2%, T3 with a concentration of 4% and T4 with a concentration of 6%. The raw materials used are pasteurized fresh cow's milk, lesser yam tuber flour, and yogurt starter. The results showed that the addition of different lesser yam tuber flour had a significant effect (P &lt;0.05) on total LAB, sugar reduction, crude fiber, viscosity, and organoleptic properties of yogurt. The ideal treatment for the addition of lesser yam tuber flour is the concentration of 2% lesser yam tuber, which produces a total LAB is 9.2 x 109, a sugar reduction is 0.653 mg/mL, crude fiber is 1.3%, 82.25 cPs, and organoleptic properties had sour taste and viscosity is rather thick which the most preferred.<br>

SURVIVAL OF SALMONELLA TYPHIMURIUM IN REFRIGERATED CULTURED MILKS1

1972 ◽  
Vol 35 (8) ◽  
pp. 489-495 ◽  
Author(s):  
H. s. Park ◽  
E. H. Marth
Keyword(s):  
Lactic Acid ◽  
Citric Acid ◽  
Lactic Acid Bacteria ◽  
Salmonella Typhimurium ◽  
Streptococcus Thermophilus ◽  
Lactobacillus Helveticus ◽  
Lactobacillus Bulgaricus ◽  
Refrigerated Storage ◽  
Streptococcus Lactis ◽  
Pure Cultures

Cultured skimmilks containing Salmonella typhimurium were prepared at 21, 30, or 42 C using different species of lactic acid bacteria (0.25, 1.0, and 5% inoculum) either singly or in combinations. Several commercial cultures also were used. Cultured skimmilks were stored at 11 C and tested at 3-day intervals for numbers of viable salmonellae and lactic acid bacteria and for pH. Survival of S. typhimurium varied from 6 to 9 days and from 3 to 6 days in milks cultured with 0.25% Streptococcus lactis at 21 and 30 C, respectively. Increasing the inoculum to 1% with incubation at 30 C yielded a product no more detrimental to S. typhimurium than when the lower inoculum was used at 30 C. Survival of S. typhimurium always exceeded 9 days when S. cremoris was used to make cultured skimmilks. Products made with commercial mixed cultures composed of S. lactis and S. cremoris allowed S. typhimurium to survive for periods intermediate between the extremes observed when pure cultures were used. Skimmilks cultured with Streptococcus diacetilactis and Leuconostoc citrovorum, even when skimmilks cultured with the latter organism were acidified with citric acid and incubated further, were essentially without effect on survival of S. typhimurium during refrigerated storage. Use of Streptococcus thermophilus (1% culture, 42 C incubation) yielded cultured skimmilks that were most detrimental to survival of salmonellae, whereas skimmilks fermented with Lactobacillus bulgaricus permitted survival of low numbers of salmonellae beyond 9 days. Milks cultured at 42 C with a 5% inoculum of S. thermophilus mixed with L. bulgaricus or Lactobacillus helveticus were free of viable salmonellae before the incubation was complete. Salmonellae grown in skimmilk at 21 C without a lactic culture were more resistant to inactivation during refrigerated storage than was S. typhimurium grown at 30 or 42 C.

Behavior of Listeria monocytogenes in the Presence of Lactic Acid Bacteria in an Agitated Medium with Internal pH Control

1991 ◽  
Vol 54 (3) ◽  
pp. 183-188 ◽  
Author(s):  
JANE M. WENZEL ◽  
ELMER H. MARTH
Keyword(s):  
Lactic Acid ◽  
Statistical Analysis ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Lactococcus Lactis ◽  
Ph Control ◽  
Lactococcus Lactis Subsp ◽  
Streptococcus Lactis ◽  
Streptococcus Cremoris ◽  
Internal Ph

An agitated medium with internal pH control (IPCM-2) was inoculated to contain Listeria monocytogenes (strain V7, Scott A or California) at ca. 103 CFU/ml and Streptococcus cremoris (Lactococcus lactis subsp. cremoris) or Streptococcus lactis (Lactococcus lactis subsp. lactis) at 0.25 or 1.0% The inoculated medium was incubated with shaking in a waterbath at 30°C for 30 h. L. monocytogenes and lactic acid bacteria were enumerated and pH was determined at appropriate intervals. The area on a figure between curves for the control and treatment and designated as the area of inhibition (AI) was calculated and used to quantify inhibition of each strain of L. monocytogenes for a particular set of conditions in IPCM-2. Statistical analysis of AI values calculated from data obtained at 6, 24, and 30 h of incubation revealed no significant (p &lt; 0.05) difference in inhibition among the three strains of L. monocytogenes for each type of lactic streptococcus present. Streptococcus cremoris was significantly (0.01 &lt; p &lt; 0.05) more inhibitory to all three strains of L. monocytogenes than was S. lactis at 24 and 30 h of incubation. IPCM-2 is considered ready for use at a pH of 5.4 or less, which was reached between 12 and 15 h of incubation in samples containing 0.25 or 1.0% S. cremoris. Populations of L. monocytogenes in such samples were ca. 104 to 106 CFU/ml regardless of strain of Listeria or percentage of S. cremoris added as inoculum. In samples initially containing 0.25 or 1.0% S. lactis, pH 5.4 was not reached until after 18–24 h of incubation. At this point all three strains of L. monocytogenes had grown to ca. 105 CFU/ml regardless of percentage of S. lactis added as inoculum. Despite the inhibition seen, substantial numbers of the pathogen were present when the medium was ready for use.

scholarly journals Exopolysaccharides of lactic acid bacteria: applied aspects

2020 ◽  
Author(s):  
N. A. Fokina ◽  
G. T. Uryadova ◽  
L. V. Karpunina
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactococcus Lactis ◽  
Streptococcus Thermophilus ◽  
Healing Effect

Exopolysaccharides Lactococcus lactis B-1662 and, to a greater extent, Streptococcus thermophilus have a healing effect on burns in rats. The exopolysaccharide Streptococcus thermophilus also has a prebiotic effect in the poultry body.

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