Papers by Jorge Reinheimer
Fil: Capra, Maria Lujan. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cient... more Fil: Capra, Maria Lujan. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Santa Fe. Instituto de Lactologia Industrial. Universidad Nacional del Litoral. Facultad de Ingenieria Quimica. Instituto de Lactologia Industrial; Argentina
International Dairy Journal, 2019
UCC Library and UCC researchers have made this item openly available. Please let us know how this... more UCC Library and UCC researchers have made this item openly available. Please let us know how this has helped you. Thanks! Title Functional properties of exopolysaccharide (EPS) extract from Lactobacillus fermentum Lf2 and its impact when combined with Bifidobacterium animalis INL1 in yoghurt
International Microbiology, 2018
Your article is protected by copyright and all rights are held exclusively by Springer Nature Swi... more Your article is protected by copyright and all rights are held exclusively by Springer Nature Switzerland AG. This e-offprint is for personal use only and shall not be selfarchived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".
Journal of Food Protection, 2000
Thermal and chemical resistance of five autochthonal bacteriophages of Streptococcus thermophilus... more Thermal and chemical resistance of five autochthonal bacteriophages of Streptococcus thermophilus, isolated from Cuartirolo cheese wheys and yogurt, was investigated. Times to obtain 99% inactivation of phages (T99)at63°C and 72°C in three suspension media (enriched tryptic soy broth, reconstituted commercial nonfat skim milk, and tris magnesium gelatin buffer) were determined. The thermal resistance was dependent on the phages studied but not detectable counts…
Journal of Food Protection, 1999
The effect of several biocides and thermal treatments on the viability of four Lactobacillus helv... more The effect of several biocides and thermal treatments on the viability of four Lactobacillus helveticus phages was investigated. Times to achieve 99% inactivation of phages at 63°C and 72°C in three suspension media were calculated. The three suspension media were tris magnesium gelatin buffer (10 mM Tris-HCl, 10 mM MgSO4, and 0.1% wt/vol gelatin), reconstituted skim milk sterile reconstituted commercial nonfat dry skim milk, and Man Rogosa Sharpe broth. The thermal resistance depended on the phage considered, but a treatment of 5 min at 90°C produced a total inactivation of high titer suspensions of all phages studied. The results obtained for the three tested media did not allow us to establish a clear difference among them, since some phages were more heat resistant in Man Rogosa Sharpe broth and others in tris magnesium gelatin buffer. From the investigation on biocides, we established that sodium hypochlorite at a concentration of 100 ppm was very effective in inactivating phag...
Journal of Food Protection, 2002
Sixty-one natural phages (59 of Streptococcus thermophilus and 2 of Lactobacillus delbrueckii sub... more Sixty-one natural phages (59 of Streptococcus thermophilus and 2 of Lactobacillus delbrueckii subsp. bulgaricus) were isolated from Argentinian dairy plants from November 1994 to July 2000. Specifically, 17 yogurt samples (18% of all samples) and 26 cheese samples (79%) contained phages lytic to S. thermophilus strains. The number of viral particles found in samples ranged from 102 to 109 PFU/ml. The phages belonged to Bradley's group B or the Siphoviridae family (morphotype B1). They showed high burst size values and remarkably short latent periods. The results of this study show that phages were found more frequently in cheesemaking processes than in yogurt-making processes. The commercial streptococcus strains appeared to propagate more phages, whereas the natural strains propagated fewer phage strains. These results suggest that the naturally occurring cultures are inherently more phage resistant.
Scientific reports, Feb 24, 2017
Gut microbiota dysbiosis plays a central role in the development and perpetuation of chronic infl... more Gut microbiota dysbiosis plays a central role in the development and perpetuation of chronic inflammation in inflammatory bowel disease (IBD) and therefore is key target for interventions with high quality and functional probiotics. The local production of stable probiotic formulations at limited cost is considered an advantage as it reduces transportation cost and time, thereby increasing the effective period at the consumer side. In the present study, we compared the anti-inflammatory capacities of the Bifidobacterium animalis subsp. lactis (B. lactis) INL1, a probiotic strain isolated in Argentina from human breast milk, with the commercial strain B. animalis subsp. lactis BB12. The impact of spray-drying, a low-cost alternative of bacterial dehydration, on the functionality of both bifidobacteria was also investigated. We showed for both bacteria that the spray-drying process did not impact on bacterial survival nor on their protective capacities against acute and chronic coliti...
Journal of Food Protection, 1997
Samples (32) of natural milk cultures used in the Santa Fe, Argentina, area for soft and semihard... more Samples (32) of natural milk cultures used in the Santa Fe, Argentina, area for soft and semihard cheese production were examined. The microbial composition (including lactic acid microflora characterization) and technological parameters (acidifying and proteolytic activities) were evaluated. The cultures contained mainly thermophilic lactic acid bacteria, identified as Streptococcus salivarius subsp. thermophilus (96.8% of the total strains) and Enterococcus spp. The strains showed a low proteolytic activity. The isolates of S. salivarius subsp. thermophilus exhibited a widespread phage resistance. The nonlactic microflora comprised coliforms, yeasts, spore-forming bacteria and lactate fermentative bacteria. The samples showed an acidity level from 0.38 to 0.69% lactic acid (pH from 4.25 to 5.75). The acidifying activity was optimal at 45°C. The advantages and disadvantages of the employment of natural milk starters are discussed.
Journal of Food Protection, 2002
The thermal and chemical resistance levels of four autochthonal bacteriophages of Lactococcus lac... more The thermal and chemical resistance levels of four autochthonal bacteriophages of Lactococcus lactis subsp. lactis, isolated from cheese processes, was investigated. The times required to obtain 99% inactivation of phages (T99) at 63 and 72°C in three suspension media (M17 broth, reconstituted commercial nonfat skim milk, and Tris magnesium gelatin buffer) were determined. Thermal resistance was dependent on the phage studied, and the results of this study demonstrate that pasteurization treatments used in dairy industries may leave viable viral particles in milk. It was possible to determine that M17 broth was generally the least protective medium, while phosphate buffer was the most protective one. Peracetic acid (0.15%, vol/vol) was the most effective viricidal agent, with exposures of 5 min being sufficient to inactivate high-titer phage suspensions (>106 PFU/ml). To achieve total inactivation (<10 PFU/ml) of viral suspensions, sodium hypochlorite was effective at 100 ppm ...
Journal of Food Protection, 2009
The effect of several biocides, thermal treatments, and photocatalysis on the viability of four L... more The effect of several biocides, thermal treatments, and photocatalysis on the viability of four Lactobacillus plantarum phages was investigated. Times to achieve 99% inactivation (T99) of phages at 63, 72, and 90°C were evaluated in four suspension media: deMan Rogosa Sharpe broth, reconstituted skim milk, a commercial EM-glucose medium, and Tris magnesium gelatin buffer. The four phages studied were highly resistant to 63°C(T99 > 45 min); however, counts < 10 PFU/ml were achieved by heating at 90°C for 5 min. Higher thermal resistance at 72°C was observed when reconstituted skim milk and EM-glucose medium were assayed. Peracetic acid (0.15%, vol/vol) was an effective biocide for the complete inactivation of all phages studied within 5 min of exposure. Sodium hypochlorite (800 ppm) inactivated the phages completely within 30 min. Ethanol (100%) did not destroy phage particles even after 45 min. Isopropanol did not have any effect on phage viability. Phage counts < 50 PFU/ml...
BMC Microbiology, 2015
Background: Bacteriophages constitute a great threat to the activity of lactic acid bacteria used... more Background: Bacteriophages constitute a great threat to the activity of lactic acid bacteria used in industrial processes. Several factors can influence the infection cycle of bacteriophages. That is the case of the physiological state of host cells, which could produce inhibition or delay of the phage infection process. In the present work, the influence of Lactobacillus plantarum host cell starvation on phage B1 adsorption and propagation was investigated. Result: First, cell growth kinetics of L. plantarum ATCC 8014 were determined in MRS, limiting carbon (S-N), limiting nitrogen (S-C) and limiting carbon/nitrogen (S) broth. L. plantarum ATCC 8014 strain showed reduced growth rate under starvation conditions in comparison to the one obtained in MRS broth. Adsorption efficiencies of > 99 % were observed on the starved L. plantarum ATCC 8014 cells. Finally, the influence of cell starvation conditions in phage propagation was investigated through one-step growth curves. In this regard, production of phage progeny was studied when phage infection began before or after cell starvation. When bacterial cells were starved after phage infection, phage B1 was able to propagate in L. plantarum ATCC 8014 strain in a medium devoid of carbon source (S-N) but not when nitrogen (S-C broth) or nitrogen/carbon (S broth) sources were removed. However, addition of nitrogen and carbon/nitrogen compounds to starved infected cells caused the restoration of phage production. When bacterial cells were starved before phage infection, phage B1 propagated in either nitrogen or nitrogen/carbon starved cells only when the favorable conditions of culture (MRS) were used as a propagation medium. Regarding carbon starved cells, phage propagation in either MRS or S-N broth was evidenced. Conclusions: These results demonstrated that phage B1 could propagate in host cells even in unfavorable culture conditions, becoming a hazardous source of phages that could disseminate to industrial environments.
Frontiers in Microbiology, 2015
Effects of sub-lethal high-pressure homogenization treatment on the outermost cellular structures... more Effects of sub-lethal high-pressure homogenization treatment on the outermost cellular structures and the volatile-molecule profiles of two strains of probiotic lactobacilli.
LWT - Food Science and Technology, 2015
In this study, we aimed at optimizing the growth of Lactobacillus rhamnosus 64 in whey permeate s... more In this study, we aimed at optimizing the growth of Lactobacillus rhamnosus 64 in whey permeate supplemented with different ingredients and we also studied the effects of mild stresses on the response to heat and oxidative challenge. Supplementation of diluted whey permeate with yeast extract, tryptone, Tween 80 and MneMg produced ca. 10 10 CFU/mL of L. rhamnosus 64 under pH controlled fermentation in anaerobiosis. Cells were exposed to different mild stresses (aerobic: 1 h air 0.3 vol vol À1 min, pH 6, 37 C); heat (1 h, pH 6, 45 C, anaerobiosis) and acid (1 h, pH 5, 37 C, anaerobiosis), followed by heat (55 C) or oxidative (0.4 mmol/L H 2 O 2) challenge (15 min). Oxidative challenge was more detrimental compared to heat challenge. Anaerobic incubation, cell harvesting at the stationary phase and mild heat stress were more effective for reducing cell death towards heat challenge, whereas cheese whey-starch was effective towards cell protection to spray drying and storage. No effects on cell survival to spray drying were observed when mild stresses were used to increase resistance to spray drying.
Journal of dairy science, 2008
High-pressure homogenization (HPH) is one of the most promising alternatives to traditional therm... more High-pressure homogenization (HPH) is one of the most promising alternatives to traditional thermal treatment of food preservation and diversification. Its effectiveness on the deactivation of pathogenic and spoilage microorganisms in model systems and real food is well documented. To evaluate the potential of milk treated by HPH for the production of Crescenza cheese with commercial probiotic lactobacilli added, 4 types of cheeses were made: HPH (from HPH-treated milk), P (from pasteurized milk), HPH-P (HPH-treated milk plus probiotics), and P-P (pasteurized milk plus probiotics) cheeses. A strain of Streptococcus thermophilus was used as starter culture for cheese production. Compositional, microbiological, physicochemical, and organoleptic analyses were carried out at 1, 5, 8, and 12 d of refrigerated storage (4 degrees C). According to results obtained, no significant differences among the 4 cheese types were observed for gross composition (protein, fat, moisture) and pH. Differ...
Journal of dairy science, 2006
Phage infections still represent a serious risk to the dairy industry, in which Streptococcus the... more Phage infections still represent a serious risk to the dairy industry, in which Streptococcus thermophilus is used in starter cultures for the manufacture of yogurt and cheese. The goal of the present study was to analyze the biodiversity of the virulent S. thermophilus phage population in one Argentinean cheese plant. Ten distinct S. thermophilus phages were isolated from cheese whey samples collected in a 2-mo survey. They were then characterized by their morphology, host range, and restriction patterns. These phages were also classified within the 2 main groups of S. thermophilus phages (cos- and pac-type) using a newly adapted multiplex PCR method. Six phages were classified as cos-type phages, whereas the 4 others belonged to the pac-type group. This study illustrates the phage diversity that can be found in one factory that rotates several cultures of S. thermophilus. Limiting the number of starter cultures is likely to reduce phage biodiversity within a fermentation facility.
Journal of dairy science, 2006
A new virulent bacteriophage (MLC-A) was recently isolated in Argentina from a probiotic dairy pr... more A new virulent bacteriophage (MLC-A) was recently isolated in Argentina from a probiotic dairy product containing a strain of Lactobacillus paracasei. Observation of the lysate with an electron microscope revealed bacteriophage particles with an icosahedral capsid of 57 +/- 2 nm; with a collar and a noncontractile tail of 156 +/- 3 nm terminating with a baseplate to which a tail fiber was attached. Therefore, phage MLC-A belongs to the Siphoviridae family. This phage was able to survive the pasteurization process and was resistant to alcohols and sodium hypochlorite (400 mg/kg). Only peracetic acid could inactivate high-titer suspensions of phages in a short time. The maximum rates of phage adsorption to its host cells were obtained at 30 degrees C with a pH between 5 and 7, and in the presence of calcium or magnesium ions. The host range of phage MLC-A encompassed L. paracasei and Lactobacillus casei strains, but it was not able to infect Lactobacillus rhamnosus or Lactobacillus ga...
Journal of Dairy Science, 2007
Journal of Functional Foods, 2015
The probiotic Lactobacillus paracasei A13, treated at 50 MPa sub-lethal high pressure homogenisat... more The probiotic Lactobacillus paracasei A13, treated at 50 MPa sub-lethal high pressure homogenisation (HPH), was used as adjunct for producing Caciotta cheese. The cell HPH treatment was used because it has been proven to increase the in vitro strain functionality. The starters and Lb. paracasei A13 viability, the cheese hydrolytic patterns and organoleptic profiles were monitored. After cheesemaking and during ripening, the Lb. paracasei A13 gastric acid resistance in cheese and the ability of the cheese, containing HPH-treated or untreated cells, to modulate the gut mucosal immune system in mice were evaluated. Traditional Caciotta was used as controls. The HPH-treated probiotic strain maintained high viability for 14 days whilst the physico-chemical analyses on Caciotta cheese containing HPHtreated cells showed a faster ripening, compared to other cheeses. For functional properties, the 50 MPa treatment increased the Lb. paracasei gastric resistance in Caciotta, maintaining high strain viability, but IL-10 producing capacity was lost by HPH-treatment whilst IgA production was not modified.
Frontiers in Microbiology, 2011
Letters in Applied Microbiology, 2004
The survival of two collection Lactobacillus casei and L. paracasei bacteriophages when subjected... more The survival of two collection Lactobacillus casei and L. paracasei bacteriophages when subjected to thermal and chemical treatments was investigated. Methods and Results: Thermal resistance was evaluated by heating phage suspensions at 63, 72 and 90°C in three different media [Tris-magnesium gelatin (TMG) buffer: 10 mmol l)1 Tris-Cl, 10 mmol l)1 MgSO 4 and 0AE1% w/v gelatin; Man Rogosa Sharpe (MRS) broth and reconstituted nonfat dry skim milk (RSM)]. A marked heat sensitivity was evident in both phages, as 15 min at 72°C was enough to completely inactivate (6 log 10 reduction) them. No clear influence was demonstrated by the suspension media. The phages also showed similar resistance to biocides. Peracetic acid and sodium hypochlorite (800 ppm) were the most effective ones, destroying the phages within 5 min. Concentrations of 75 and 100% ethanol were not suitable to inactivate phage particles even after 45 min. Isopropanol did not show an effect on phage viability. Conclusions: The data obtained in this work are important to design more effective control procedures in order to inactivate phages in dairy plants and laboratories. Significance and Impact of the Study: This work will contribute to enhance the background knowledge about phages of probiotic bacteria.
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Papers by Jorge Reinheimer