In vitro comparison of probiotic properties of Lactobacillus casei Zhang, a potential new probiotic, with selected probiotic strains

Since 2004, our research group has isolated 240 Lactobacillus strains from Koumiss, a traditional fermented alcoholic beverage prepared from mare's milk in Inner Mongolia, Xinjiang of China and Mongolia. Among these Lactobacillus strains a novel strain with potential probiotic properties, Lactobacillus casei Zhang, was screened out and studied extensively for its probiotic properties, health-promoting effects and fermentation characteristics. In vitro tests indicated that L. casei Zhang had high tolerance to simulated gastric, intestine juices and bile salts, similar to commercial probiotic strains such as Lactobacillus acidophilus NCFM, Lactobacillus rhamnosus GG, L. casei Shirota and Bifidobacterium animalis Bb12. Higher acid-production activity and proteolytic activity was observed in the fermented milk inoculated with L. casei Zhang during the refrigerated storage than in the samples inoculated with the selected commercial probiotics. The yogurt samples fermented with L. casei Zhang exhibited similarer viable count (1.0 × 10⁹ cfu/mL) as the other samples after 28 d of refrigerated storage. The results suggested that L. casei Zhang showed good potential for application in functional foods and health-related products.     

Effects of 4 Probiotic Strains in Coculture with Traditional Starters on the Flavor Profile of Yogurt

To study the influence of probiotics on the flavor profile of yogurt, 4 probiotics, including Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus rhamnosus, and Lactobacillus casei, were cofermented with traditional starters. The changes of bacterial growth, acid contents and volatile compounds of yogurt were investigated during fermentation and refrigerated storage. The strains that exhibited a low growth rate in milk did not significantly affect the bacterial population dynamics, acidity, or organic acid content during fermentation and storage. However, high viability and enhancement of postacidification were clearly observed in the samples that contained strains with a high growth rate in milk, particularly L. casei. A total of 45 volatile compounds, detected in most samples, were identified by headspace solid‐phase micro‐extraction followed by gas chromatography‐mass spectrometry. Among these compounds, ketones and aldehydes were the most abundant. The presence of either L. rhamnosus or L. plantarum did not significantly affect the major volatile compounds, while contributions of L. casei and L. acidophilus were found in the formation of minor volatile metabolites. Electronic nose measurements exhibited a good discrimination of samples that contained different probiotics during refrigerated storage.     

Discrimination of dairy industry isolates of the Lactobacillus casei group

Lactobacilli are a major part of the microflora of the gut and of many fermented dairy products, and are found in a variety of environments. Lactobacillus casei, Lactobacillus paracasei, Lactobacillus rhamnosus, and Lactobacillus zeae form a closely related taxonomic group within the facultatively heterofermentative lactobacilli. The classification and nomenclature of these bacteria are controversial. In this study, relationships between these species were investigated using type strains and dairy industry isolates examined with DNA-based techniques and conventional carbohydrate use tests. Carbohydrate use patterns gave poor discrimination of some species, but DNA PCR using specific primers targeted to sequences of the 16S rRNA gene discriminated 4 types consistent with the currently recognized species. Pulsed-field agarose gel electrophoresis of chromosomal NotI restriction fragments identified 18 different band patterns from 21 independent Lactobacillus isolates and confirmed the identity of L. casei strains from 2 culture collections (CSCC 5203 and ASCC 290), both representing the type strain of L. casei. Some isolates were reclassified as L. rhamnosus, suggesting that the prevalence of L. rhamnosus as a natural component of the microflora of dairy foods and dairy environments has previously been underestimated. These methods can provide a practical basis for discrimination of the species and identification of individual industrial strains.     

Resistance of Lactobacillus casei KCTC 3260 to Reactive Oxygen Species (ROS): Role for a Metal Ion Chelating Effect

The antioxidative capacity of 4 Lactobacillus strains, isolated from a milk product, was evaluated by measuring total antioxidative ability (TAA) and resistance to reactive oxygen species (ROS). Both intact cells and intracellular cell‐free extracts of Lactobacillus casei KCTC 3260 demonstrated the highest antioxidative activity and inhibited lipid peroxidation by 46.2% and 72.9%, respectively. To evaluate the resistance of 4 Lactobacillus strains to ROS, we tested the survival under conditions of 1 mM hydrogen peroxide, 0.4 mM hydroxyl radicals, and 10 mM paraquat‐induced superoxide anions. L. casei KCTC 3260 was viable even after 8 h in the presence of 1 mM hydrogen peroxide and after 7 h in 0.4 mM hydroxyl radicals. Moreover, this strain was not influenced by superoxide anions, indicating that it has resistance to superoxide anions. To define the antioxidative mechanism, superoxide dismutase (SOD) and metal ion chelating activity were determined. All tested strains did not possess detectable SOD activity except Lactobacillus rhamnosus GG, but L. casei KCTC 3260 had the higher level of chelating activity for both Fe²⁺ and Cu²⁺ ions at 10.6 ppm and 21.8 ppm, respectively. These results suggested that the antioxidative capacity of L. casei KCTC 3260 may be caused by chelating metal ions instead of SOD activation.     

Nucleotide Sequence Identities of horA Homologues and Adjacent DNA Regions Identified in Three Species of Beer‐Spoilage Lactic Acid Bacteria

The horA homologues and adjacent DNA regions identified in beer‐spoilage Lactobacillus lindneri DSM 20690^Tand L. paracollinoides DSM15502^Twere examined and compared with the corresponding DNA region of beer‐spoilage L. brevis ABBC45, a strain in which the hop‐resistance gene horA was originally identified. The PCR analysis suggests ORFB1‐B5 regions surrounding horA are conserved in all of the strains. The nucleotide sequence comparison of the conserved DNA regions revealed extremely high levels of identities among the three beer‐spoilage strains that are not typical for distinct species. The PCR methods using primers specific to the adjacent ORFs were found to be able to differentiate beer‐spoilage Lactobacillus strains from non‐spoilers, indicating these ORFs are also useful genetic markers for determining the beer‐spoilage ability of lactobacilli. The presence or absence of the adjacent ORFs in 92 bacterial strains was completely identical with that of horA homologues, indicating the ORFB1‐B5 regions are generally conserved in beer‐spoilage Lactobacillus strains. Taken together, these results suggest the ORFB1‐B5 regions have been acquired by beer‐spoilage lactobacilli through horizontal gene transfer and provide a theoretical basis for applying a trans‐species genetic marker such as horA to deal with unencountered species of beer‐spoilage lactobacilli.     

Production of organic acids by Lactobacillus strains in three different media

Ten strains of Lactobacillus (Lb). casei, Lb. rhamnosus, Lb. plantarum, Lb. paracasei and Lb. curvatus species were chosen to determine the production of organic acids after cultivation in skimmed milk, MRS broth and Jerusalem artichoke (JA) medium. The highest acidity was obtained in MRS broth and the weakest acidification was found in skimmed milk. Lb. casei Shirota produced the highest amount and Lb. rhamnosus VT1 the lowest amount of substances being estimated as titratable acidity. All strains produced lactic acid in the investigated broth and most of the strains produced acetic acid in MRS broth except Lb. curvatus 2768 and Lb. casei Shirota, in JA broth except Lb. paracasei SF1 and in skimmed milk except Lb. casei 2750, Lb. curvatus 2768, Lb. curvatus 2775 and Lb. casei Shirota. All strains, except Lb. plantarum 01, produced butyric acid in MRS broth. Beside the lactic and acetic acids, formic, citric, succinic and glutamic acids were also produced in MRS broth; formic and succinic acids were produced in skimmed milk and succinic acid in JA broth. Some strains showed change in their fermentation profile from homofermentative to mix-acid fermentation in milk. The antifungal efficiency of the lactic and acetic acid in the amount produced by lactobacilli was investigated. None of the investigated aspergilli were inhibited. The inhibitory effect of acids against Fusarium increased unequivocally with the increasing concentration. The study pointed at the dissimilarity of organic acid production of Lactobacillus strains, which was considerably influenced by the media.     

Effect of Lactate on the Growth and Production of Diacetyl and Acetoin by Lactobacilli

Diacetyl and acetoin production and cell growth in Lactobacillus acidophilus CNRZ 232, Lactobacillus casei ssp. rhamnosus ATCC 7469, Lactobacillus brevis ATCC 14869, and Lactobacillus fermentum ATCC 9338 were studied. The first three species produced large amounts of diacetyl and acetoin when pyruvate was included in a medium with yeast extract, peptone, tryptone, and glucose. Lactobacillus fermentum failed to produce the compounds under consideration.Lactobacillus acidophilus, Lactobacillus casei, and Lactobacillus brevis utilized lactate as a carbon source. When lactate was added to the medium containing pyruvate, the diacetyl, acetoin, and biomass decreased in Lactobacillus casei and Lactobacillus brevis. In Lactobacillus acidophilus both compounds decreased somewhat, and bacterial growth increased, although it decreased again at high lactate concentrations. There was no production of diacetyl and acetoin at pH lower then 4.25 and only little at 4.25.     

In vitro assessment of antimicrobial efficacy of the D-tagatose and lactobacilli-based synbiotic preparations against the pathogenic Escherichia coli and Salmonella typhimurium

The study aimed to investigate the utilisation of prebiotic D-tagatose by probiotic lactobacilli (L. rhamnosus GG, L. casei, L. acidophilus and L. fermentum) and enteric pathogens (E. coli and S. typhimurium) to determine synbiotic potential of D-tagatose and lactobacilli combination. The antimicrobial efficacy of the synbiotic preparations (D-tagatose with lactobacillus) was assessed against selected pathogens in co-culture assays. Evidently, D-tagatose supported growth of selected lactobacilli, especially the L. rhamnosus GG and L. casei, but not the enteric pathogens. The tested synbiotic preparations completely inhibited growth of both the pathogens, even in the presence of D-glucose in co-cultures. The well-diffusion assay demonstrated the presence of antimicrobial activity as recorded by drop of culture pH. The study substantiated that D-tagatose could be an effective prebiotic component for formulation of potential synbiotic combinations with L. rhamnosus GG or L. casei that can be used as an alternative to antibiotics against enteric pathogens.     

Improvement in antioxidant activity,angiotensin‐converting enzyme inhibitory activity and in vitro cellular properties of fermented pepino milk by Lactobacillus strains containing the glutamate decarboxylase gene

BACKGROUND: The purpose of this study was to evaluate the functional potential of fermented pepino extract (PE) milk by Lactobacillus strains containing the glutamate decarboxylase (GAD) gene. Three Lactobacillus strains were selected, including L. brevis BCRC 12310, L. casei BCRC 14082 and L. salivarius subsp. salivarius BCRC 14759. The contents of free amino acids, total phenolics content, total carotenoids and the associated functional and antioxidant abilities were analyzed, including angiotensin‐converting enzyme (ACE) inhibition activity, 1,1‐diphenyl‐2‐picylhydrazyl (DPPH) radical‐scavenging ability and oxygen radical absorbance capacity (ORAC). Cell proliferation of fermented PE milk was also evaluated by MTT (3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide) assay. RESULTS: Compared to the unfermented PE, fermented PE milk from Lactobacillus strains with the GAD gene showed higher levels of total phenolics, γ‐aminobutyric acid, ACE inhibitory activity, DPPH, and ORAC. The viability of human promyelocytic leukemia cells (HL‐60) determined by the MTT method decreased significantly when the cells were incubated with the PE and the fermented PE milk extracts. CONCLUSION: The consumption of fermented PE milk from Lactobacillus strains with the GAD gene is expected to benefit health. Further application as a health food is worthy of investigation. © 2012 Society of Chemical Industry     

Cell wall hydrolase as a surface-associated protein target for the specific detection of Lactobacillus rhamnosus using flow cytometry

Flow cytometry (FC) is a very popular technique for to the study of different eukaryotic cell phenotypes. In addition, FC has many applications in the field of food microbiology, although the few number of specific molecules that can be potentially targeted with fluorescence-conjugated antibodies limits its potential applications. The present work represents a step forward in the application of FC for detection of specific foodborne or probiotic bacteria by using fluorescent antibodies binding specific surface-associated protein. To illustrate this novel approach, we have used a monoclonal and polyclonal antibodies targeting cell-wall hydrolase (CWH), one of the major surface-associated proteins of the probiotic Lactobacillus rhamnosus GG. In order to verify the specific union of the antibodies to this surface protein, ten different bacterial strains belonging to different bacteria species taxonomically related and no related to L. rhamnosus, were tested. The optimal conditions for bacteria detection corresponded to a final suspension of 5E10⁷ bacteria in exponential phase of growth using FC buffer, without freezing, without adding extra BSA to the FC buffer and without fixing bacteria. Our results showed that GG strain was detected using the polyclonal anti-CWH serum in a higher extent (91.62%) than the rest of strains (L. casei 393: 64.49%; L. amylovorus: 46.13%, E. coli: 45.13%; L. acidophilus DSM20079^T: 35.83%; B. longum NCIMB8809: 33.68%; L. gasseri BM7/10: 32.41%; L. reuteri DSM21016: 29.26%; L. plantarum NCIMB8826: 26.33% and L. delbruekii: 22.52%). The percentage of L. rhamnosus labeled with the monoclonal antibody was 53.06, which contrasted with the 91.62% labeled with the polyclonal antibody. The low affinity of the monoclonal antibody was perhaps due to the lack of immunogenicity of the single epitope chosen for antibody generation (CWHp). The high efficiency observed for the polyclonal anti-CWH serum is maybe a consequence of being constituted by a mixture of antibodies that recognizes different epitopes in the L. rhamnosus GG protein.With this proof of concept, we have shown for the first time that foodborne or probiotic bacteria can be specifically detected using antibodies targeting adequate molecules present on their surface.     

Molecular Characterization and Identification of Bioactive Peptides Producing Lactobacillus sps. Based on 16S rRNA Gene Sequencing

In the present study, 3 bacterial cultures were isolated from faecal samples of human infant. The biochemical traits showed similarity with Lactobacillus sps and 16S rRNA sequence analyses, confirmed as Lactobacillus plantarum, Lactobacillus casei, and Lactobacillus rhamnosus. The cultures were screened for their proteolytic activity and good ability to release peptides from milk proteins was found. Hence, these bacteria were used as a proteolytic starter culture for the fermentation of skim milk and whey for the liberation of small peptides. Bioactive nature of the peptides released from whey and skim milk was tested, and results demonstrated that peptides obtained after fermentation of whey and skim milk by Lactobacillus strains showed antimicrobial activity against all the pathogens causing food borne infections in humans. These peptides also indicated antioxidant as well as ACE (angiotensin-converting enzymes) inhibitory activity.     

DNA Arrays and Membrane Hybridization Methods for Screening of Six Lactobacillus Species Common in Food Products

Dot blot and deoxyribonucleic acid (DNA) array hybridization assays for the traceability of Lactobacillus species in food have been developed to monitor and validate typical food products. A primer set was designed to amplify the 540-bp region located at +157 of the tuf (Elongation factor Tu) gene of the Lactobacillus genus. An oligonucleotide array, containing 73 Lactobacillus species-specific tuf sequences representing 21 species, was developed and tested for identifying L. paracasei, L. rhamnosus, L. plantarum, and L. buchneri. We also tested a rapid screening method for monitoring the species present in airy samples. Dot blot hybridization identified polymerase chain reaction amplicons immobilized on nylon membranes, using six tuf-based cyanine-3-labeled 18-mer oligonucleotides, specific for L. paracasei, L. zeae, L. fermentum, L. plantarum, L. rhamnosus, and L. buchneri. This method discriminates between multiple species of Lactobacilli isolated directly from cheese samples, simultaneously. The tuf gene sequences, verified here with the DNA array method and used in dot blot hybridization, were shown to be a reliable tool for the simultaneous detection and differentiation of four Lactobacillus species. The hybridization techniques developed in this study may be useful in food processing and the analysis of food origin traceability.     

Lactobacillus GG—a human probiotic strain with thorough clinical documentation

Abstract

Probiotic bacteria for human nutrition are generally strains of lactic acid bacteria or bifidobacteria. The beneficial effects of these strains on human health and well‐being are documented in experimental and clinical studies. Lactobacillus (casei subsp.) rhamnosus GG (ATCC 53103) is a probiotic strain of human origin. The strain has most of the characteristics generally proposed for a good probiotic strain, including excellent survival in the stomach and small intestine and transient colonization of the gastrointestinal tract, which is based on its adhesion capacity to intestinal cells. Successful recovery of the strain in stool samples has made dose‐response studies possible and enabled the evaluation of effective dosing using food products. The beneficial effects of the strain have been shown in many types of intestinal disturbances caused by pathogenic bacteria and viruses, as well as in prophylactic use. The latest studies on Lactobacillus GG have shown stabilizing effect on gut permeability and suppression of allergic reactions in food hypersensitivity. The safety of Lactobacillus GG has been documented in experimental, clinical, and epidemiological studies. The scientific documentation of Lactobacillus GG is reviewed in reference to uses in functional and clinical foods.     

Die Mikroflora des Sauerteiges XXI. Mitteilung: Die in Sauerteigen schwedischer B?ckereien vorkommenden Lactobacillen

Zusammenfassung Es wurden Untersuchungen angestellt über die Bakterienflora von 9 Sauerteigen, die in schwedischen Bäckereien bei der Bereitung von Roggen/Weizen-Mischbroten und Weizenbroten Anwendung finden. Bei diesen Sauerteigen fanden als Starter Sauerteige Anwendung, die z. T. seit mehr als 10 Jahren fortgeführt werden. Es wurden insgesamt 238 Isolate gewonnen und als Vertreter der GattungLactobacillus identifiziert. Von den Isolaten waren 31 der UntergattungThermobacterium (Lactobacillus delbruekkii,L. delbrueckii ssp.bulgaricus,L. acidophilus) zuzuordnen, 40 Isolate der UntergattungStreptobacterium (Lactobacillus plantarum,L. casei rhamnosus,L. farciminis) und 112 Isolate der UntergattungBetabacterium (Lactobacillus fermentum,L. brevis ssp.lindneri,L. viridescens,L. brevis). Weitere 55 Isolate homo- und heterofermentativer Sauerteigbakterien waren nicht eindeutig einer Art des GenusLactobacillus zuzuordnen. Aufgrund der Verbreitung, der Häufigkeit des Auftretens und des Verhaltens im Säuerungsversuch sind für die untersuchten SauerteigeLactobacillus fermentum sowie die nicht identifizierten Sauerteigbakterien der Gruppierung h als typisch anzusehen.

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The Microflora of Sourdough. XXI. Communication: The lactobacillus species of sourdough from Swedish bakeries

Summary We investigated the bacterial flora of 9 sourdoughs which are used for the preparation of mixed breads (rye/wheat flour) and wheat breads in Swedish bakeries. These sourdoughs were employed as starter and some of them have been propagated for more than ten years. 238 isolates were obtained and speciated asLactobacillus. 31 of the isolates belonged to the subspeciesThermobacterium (Lactobacillus delbrueckii, L. delbrueckii ssp.bulgaricus,L. acidophilus), 40 to the subspeciesStreptobacterium (Lactobacillus plantarum,L. casei rhamnosus,L. farciminis) and 112 isolates to the subspeciesBetabacterium (Lactobacillus fermentum,L. brevis ssp.lindneri,L. viridescens,L. brevis). A further isolates 55 of homo- and heterofermentative sourdough bacteria did not clearly belong to any species of the genusLactobacillus. Because of the frequency of occurence and the behaviour in the acidification testLactobacillus fermentum and the not identified sourdough bacteria of group h are typical for the investigated sourdoughs.

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Nr. 5237 der Veröffentlichungen der Bundesforschungsanstalt für Getreide- und Kartoffelverarbeitung, Detmold     

Development of probiotic-enriched dried fruits by vacuum impregnation

In this study an attempt is made to combine the beneficial effects of probiotics with fruit and vegetables by applying the vacuum impregnation process. Apple cylinders were impregnated either with commercial apple juice containing Saccharomyces cerevisiae, and with whole milk or apple juice containing 10⁷ or 10⁸ cfu/ml of Lactobacillus casei (spp. rhamnosus). Impregnated apple samples contained around 10⁷ cfu/g. In order to increase stability and to assure fruit preservation, impregnated apple samples were air dried at 40 °C to a water content of 0.037 kg water/kg dry matter and stored at room temperature for two months. The content of L. casei viable cells in dried and stored product was greater than 10⁶ cfu/g. This concentration level of probiotics is similar to that in commercial dairy products.     

Effects of Germination and Pure Culture Fermentation by Yeasts and Lactobacilli on Phytic Acid and Polyphenol Content of Pearl Millet

Germination of pearl millet at 30°C for 24 hr reduced phytic acid significantly (P<0.05) which, on fermentation with mixed pure cultures of Saccharomyces diastaticus, Saccharomyces cerevisiae, Lactobacillus brevis, and Lactobacillus fermentum at 30°C for 72 hr, was eliminated or reduced to negligible levels in fermented sprouts. Concentration of polyphenols did not change on germination. The fermentation of sprouts by combinations of S. cerevisiae with L. brevis and S. cerevisiae and L. fermentum did not change polyphenol whereas S. diastaticus with L. brevis (SdLb) increased and S. diastaticus with L. fermentum combinations decreased the polyphenol in the sprouts.     

Evaluation of aflatoxin decontaminating by two strains of Saccharomyces cerevisiae and Lactobacillus rhamnosus strain GG in pistachio nuts

In this study, the surface binding ability of Saccharomayces cerevisiae and Lactobacillus rhamnosus GG (LBGG) to aflatoxin in pistachio nuts was compared. Results showed that Saccharomayces cerevisiae and Lactobacillus rhamnosus strains had aflatoxin binding ability of 40% and 35% with initial concentration of 10 ppb and 70% and 60% with initial concentration of 20 ppb aflatoxin, respectively. Acid treatment increased this ability for yeast and bacterium to 60% and 85% in first concentration and 73% and 90% for second concentration of aflatoxin, respectively. Also, heat treatment could raise surface binding of yeast to 55% and 75% for two concentrations. In addition, heat condition for Lactobacillus improved binding to 85% and 90% for two concentrations of aflatoxin. Experiments showed that microorganism’s immobilisation on contaminated pistachio had no effect on qualitative characteristics of pistachio such as colour, texture and peroxide value.     

Survival and activity of 5 probiotic lactobacilli strains in 2 types of flavored fermented milk

The viability of 5 probiotic lactobacilli strains (Lactobacillus acidophilus LA-5, Lactobacillus casei L01, Lactobacillus casei LAFTI L26, Lactobacillus paracasei Lcp37, and Lactobacillus rhamnosus HN001) was assessed in 2 types of probiotic flavored drink based on fermented milk during 21 days of refrigerated storage (5°C). Also, changes in biochemical parameters (pH, titrable acidity, and redox potential) during fermentation as well as the sensory attributes of final product were determined. Among the probiotic strains, L. casei LAFTI L26 exhibited the highest retention of viability during refrigerated storage period, while L. acidophilus LA-5 showed the highest loss of viability during this period. The decline in cell count of probiotic bacteria in strawberry fermented milk was significantly greater compared to peach fermented milk. In an overall approach, peach fermented milk containing L. casei LAFTI L26 was selected as the optimal treatment in this study in both aspects of viability and sensory accpeptibility.     

Die Mikroflora des Sauerteiges

Zusammenfassung Es wurde dem Verhalten heterofermentativer Sauerteigbakterien bei gemeinsamer Kultur mit Hefen nachgegangen. Diese Untersuchungen erstreckten sich aufLactobacillus brevis, L. brevis var. lindneri undL. fermentum einerseits, sowic aus Sauerteigen isolierte Hefen (Candida krusei, Pichia saitoi, Torulopsis holmii, Saccharomyces cerevisiae) andererseits. Das Verhalten der Mischkulturen wurde an Sauerteigen aus Roggenmehl (Type 997, Teigausbeute 180, 27–28 °C, 18 Std) studiert. Je nach den zueinander in Wechselbezichung tretenden Sauerteigbakterien und Hefen ergab sich eine unterschiedliche Beeinflussung der Säurebildung. WährendTorulopsis holmii insbesondere die vonLactobacillus brevis undL. brevis var. lindneri ausgehende Teigsäuerung um bis zu fünf Einheiten erhöhte, bedingteSaccharomyces cerevisiae eine Förderung der vonL. brevis var. lindneri undL. fermentum ausgehenden Säuerung des Sauerteiges.

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The microflora of sourdoughXV. Communication: On the behaviour of heterofermentative sourdough bacteria and yeasts in mixed culture

Summary The behaviour of heterofermentative sourdough bacteria in mixed culture with yeasts was investigated. The investigations includedLactobacillus brevis, L. brevis var. lindneri andL. fermentum as well as several yeasts, isolated from sourdough (Candida krusei, Pichia saitoi, Torulopsis holmii, Saccharomyces cerevisiae). The behaviour of the mixed cultures was studied in ryeflour doughs (Type 997, dough yield 180, 27–28 °C; 18 h). Depending on specific interrelationships between types of sourdough bacteria and yeasts influence on acidification varied.Torulopsis holmii raised the dough acidification produced byLactobacillus brevis andL. brevis var. lindneri by up to five units;Saccharomyces cerevisiae enhanced the acidification byL. brevis var. lindneri andL. fermentum.

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Nr. 4676 der Veröffentlichungen der Bundesforschungsanstalt für Getreide- und Kartoffelverarbeitung, Detmold

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Diese Untersuchungen wurden ermöglicht durch eine finanzielle Förderung seitens des Bundesministeriums für Forschung und Technologie im Rahmen des Programms Biologic and Technologic