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PubMed1994

Use of Lactobacillus plantarum LPCO10, a Bacteriocin Producer, as a Starter Culture in Spanish-Style Green Olive Fermentations.

Bacteriocin-producing Lactobacillus plantarum LPCO10 and its non-bacteriocin-producing, bacteriocinimmune derivative, L. plantarum 55-1, were evaluated separately for growth and persistence in natural Spanish-style green olive fermentations. Both strains were genetically marked and selectively enumerated using antibiotic-containing media. Plasmid profile and bacteriocin production (bac) were used as additional markers. When olive brines were inoculated at 10 CFU/ml, the parent strain, LPCO10, proliferated to dominate the epiphytic microflora, sharing high population levels with other spontaneously occurring lactobacilli and persisting throughout the fermentation (12 weeks). In contrast, the derivative strain could not be isolated after 7 weeks. Stability of both plasmid profile and bac (LPCO10 strain) or bac (55-1 strain) phenotype was shown by L. plantarum LPCO10 and L. plantarum 55-1 isolated throughout the fermentation. Bacteriocin activity could be found in the L. plantarum LPCO10-inoculated brines only after ammonium sulfate precipitation and concentration (20 times) of the final brine. Spontaneously occurring lactobacilli and lactic coccus populations, which were isolated from each of the fermenting brines studied during this investigation, were shown to be sensitive to the bacteriocins produced by L. plantarum LPCO10 when tested by the drop diffusion test. The declines in both pH and glucose levels throughout the fermentative process were similar in L. plantarum LPCO10- and in L. plantarum 55-1-inoculated brines and were comparable to the declines in the uninoculated brines. However, the final concentration of lactic acid in L. plantarum LPCO10-inoculated brines was higher than in the L. plantarum 55-1-inoculated brines and uninoculated brines. These results indicated that L. plantarum LPCO10 may be useful as a starter culture to control the lactic acid fermentation of Spanish-style green olives.

Journal Article↗
PubMed1975

Changes in microbial population during fermentation of feedlot waste with corn.

A new process for recycling feedlot waste involves the fermentation of liquid from this waste combined with corn. Changes in the flora of this silage-like fermentation were followed. The fermentation was dominated by lactobacilli and yeasts, which initially constitute 1% or less of the natural flora. The species of yeasts and lactics involved were characterized. The fermentation has two phases. A single heterolactic species multiplied rapidly for the first 24 h until it represented 95% of the lactobacilli and more than 90% of the total microflora. It displaced the betabacterium predominant among lactics of the original waste; the acid produced killed coliforms and other organisms in feedlot waste; and the acetic acid produced probably caused the death of the dominant native yeast Trichosporon cutaneum (de Beurm., Gougerot et Vaucher) Ota. The peak lactobacillus count remained constant (about 2 x 10 organisms/g [wet weight]) throughout the rest of the fermentation. Homolactics dominated the later phase and yeasts increased to 9.5 x 10 organisms/g (wet weight). At 6 days, a stable mixture of three lactobacilli was present, one streptobacterium, one thermobacterium, and one betabacterium. Similarly, yeasts stabilized as a mixture of two Candida sp. and one Pichia sp. The dominant species of lactics were characterized. Information on the sequence of microorganisms provides a basis for enhanced protein synthesis in the fermentation.

Journal Article↗
PubMed1979

Distribution of the phosphoenolpyruvate:glucose phosphotransferase system in fermentative bacteria.

A number of selected fermentative bacteria were surveyed for the presence of the phosphoenolpyruvate:glucose phosphotransferase system, with particular attention to those organisms which ferment glucose by pathways other than the Embden-Meyerhof-Parnas pathway. The phosphoenolpyruvate:glusoe phosphotransferase system was found in all homofermentative lactic acid bacteria tested that ferment glucose via the Embden-Meyerhof-Parnas pathway, but in none of a group of heterofermentative species of Lactobacillus or Leuconostoc, which ferment glucose via the phosphoketolase pathway. A phosphoenolpyruvate:glucose phosphotransferase system was also absent in Zymomonas mobilis, which ferments glucose via an anaerobic Entner-Doudoroff pathway. It thus appears that the phosphotransferase mode of glucose transport is limited to bacteria with the Embden-Meyerhof-Parnas mode of glucose fermentation.

Adenosine Triphosphate↗
PubMed1969

Effects of carbon dioxide on growth and maltose fermentation by Bacteroides amylophilus.

The requirement of carbon dioxide for growth of Bacteroides amylophilus is quantitatively similar to that of certain other rumen bacteria. Carbon dioxide could be replaced by bicarbonate, but not by formate or certain amino acids. Label from (14)CO(2) was incorporated into the succinate produced during maltose fermentation by B. amylophilus, and during glucose fermentation by B. ruminicola, and during cellobiose fermentation by B. succinogenes. All of the incorporated label could be associated with the carboxyl function of the molecule. The depression in radioactivity per micromole of carbon in the succinate formed from the fermentation of uniformly labeled (14)C-maltose by B. amylophilus was greater than would be expected if all of the succinate formed was produced via a direct CO(2) fixation pathway(s) involving phosphoenolpyruvate or pyruvate; the radioactivity per micromole of carbon suggests that as much as 60% of the total succinate results from a pathway(s) involving direct CO(2) fixation. Maltose fermentation by B. amylophilus was dependent upon CO(2) concentration, but CO(2) concentration could not be shown to influence either the fermentation end-product ratios or the proportion of total succinate formed attributable to CO(2) fixation.

Amino Acids↗
PubMed2004

Fermented milks, probiotic cultures, and colon cancer.

Colorectal cancer (CRC) is a major cause of death from cancer in the Western world. Approximately 70% of CRC is associated with environmental factors, probably mainly the diet. There is interest in the potential protective role of fermented milks containing probiotic cultures against CRC. This article analyzes the existing data from human, animal, and in vitro studies that explore whether consumption of milks fermented with probiotic cultures could play a role in colon cancer risk reduction. Cohort studies have failed to detect significant effects, but most case-control studies favor a protective role of fermented milks against colon cancer. Interventional studies have shown a shift of intermediate markers of CRC risk in human subjects from a high- to low-risk pattern after ingestion of fermented milks or probiotics. Animal studies consistently show a reduction in chemically induced colorectal tumor incidence and aberrant crypt formation accompanying probiotic administration. In vitro studies also provide evidence of protection, and permit a better understanding of active compounds involved, and of the mechanisms underlying their anticarcinogenic effects. Probiotics may beneficially modulate several major intestinal functions: detoxification, colonic fermentation, transit, and immune status, which may accompany the development of colon cancer. Although the evidence is not conclusive and much further research is required, the data reviewed constitute a promising body of evidence supporting the protective role of milks fermented with probiotic cultures in colon cancer risk reduction.

Animals↗
PubMed2006

Inulin-containing biomass for ethanol production: carbohydrate extraction and ethanol fermentation.

The use of stalks instead of tubers as a source of carbohydrates for ethanol production has been investigated. The inulin present in the stalks of Jerusalem artichoke was extracted with water and the effect of solid-liquid ratio, temperature, and acid addition was studied and optimized in order to attain a high-fructose fermentable extract. The maximum extraction efficiency (corresponding to 35 g/L) of soluble sugars was obtained at 1/6 solid-liquid ratio. Fermentations of hydrolyzed extracts by baker's yeast and direct fermentation by an inulinase activity yeast were also performed and the potential to use this feedstock for bioethanol production assessed. The results show that the carbohydrates derived from Jerusalem artichoke stalks can be converted efficiently to ethanol by acidic hydrolysis followed by fermentation with Saccharomyces cerevisiae or by direct fermentation of inulin using Kluyveromyces marxianus strains. In this last case about 30 h to complete fermentation was required in comparison with 8-9 h obtained in experiments with S. cerevisiae growth on acid extracted juices.

Biomass↗
PubMed2006

Fermented dairy products: knowledge and consumption.

PURPOSE: Much has been published on the nutritional and health benefits of fermented dairy products, especially those containing probiotic microorganisms. However, consumers may not be familiar with the term "fermented dairy products," and therefore may not take full advantage of them. University students' knowledge and consumption patterns of fermented dairy products were assessed. METHODS: University students (n=223) completed a survey consisting of a section on demographics and another on knowledge and consumption patterns. RESULTS: The majority of respondents (62%) were not familiar with the term "fermented dairy products." Most respondents consumed yogourt a few times a week (40%) or a few times a month (30%). Almost all respondents (92%) were unable to identify the difference between regular and probiotic yogourt. Most respondents (93%) had not heard of acidophilus milk, but the majority (65%) would be willing to try it. Most respondents were unsure whether sour cream (65%), yogourt beverages (74%), and cheddar cheese (61%) were fermented dairy products. Sixty percent of respondents never consumed yogourt drinks. CONCLUSIONS: Education is needed about fermented dairy products, especially probiotics, and their nutritional and health benefits. Such education may increase their acceptability and consumption.

Adolescent↗
PubMed2006

Determination of the antihypertensive peptide LHLPLP in fermented milk by high-performance liquid chromatography-mass spectrometry.

Among different lactic acid bacteria isolated from raw milk, 4 Enterococcus faecalis strains have stood out as producers of fermented milk with potent antihypertensive activity. The peptide beta-casein f(133-138), LHLPLP, was identified as one of the major peptides responsible for the activity of these fermented milk products. A simple method was developed to quantify this peptide in fermented milk using high-performance liquid chromatography coupled in line with mass spectrometry. This procedure does not require any previous sample fractionation or extraction, and direct analysis of the water-soluble extract obtained from the fermented milk can be performed. Validation studies showed sufficient specificity, reproducibility, linearity, and recovery, demonstrating that this method can be used for the routine quantification of LHLPLP during the production of fermented milk products. The developed method was readily applied to quantify the peptide LHLPLP under different fermentation conditions and with different aromatized products.

Animals↗
PubMed2026

Transcriptomic shift in ethanol and amino acid metabolic genes regulated by Med15 during alcoholic fermentation.

Organisms that thrive in extreme environments provide natural experiments in evolution, revealing the genetic regulators that orchestrate complex phenotypic change. Wine yeast are specialized strains that are adapted to survive in the wine making environment while producing high concentrations of ethanol. In addition to large genomic changes that differentiate wine yeast from yeast used in other industries, single nucleotide and polyglutamine tract polymorphisms in the transcriptional regulator Med15 are associated with the fermentation efficiency and stress response phenotypes of wine yeast. In this study we investigated the transcriptional differences during wine fermentation in transgenic lab strain yeast having integrated wine yeast MED15 alleles. Compared to the unmodified lab strain (LAB or MED15 LAB ), the same strain in which the MED15 locus was replaced with a MED15 allele from yeast isolated from palm wine, the fermented sap of palm (oil, date, coconut) trees, (WY23, or MED15 WY23 ) exhibited enhanced expression of glycolytic, fermentation, and amino acid biosynthesis genes. Our experimental data confirms the importance of arginine biosynthetic genes during the fermentation process and suggests that the improvement in fermentation efficiency in strains with MED15 alleles from some wine yeast strains may be related to the role of Med15 in expression of the genes of the arginine biosynthetic pathway. The global benefit conferred by polymorphisms in a single transcriptional regulator, makes Med15 a prime target for engineering of strains devoted to various types of alcohol production.

Journal Article↗
PubMed2003

Effects of C N ratio and pH of raw materials on oil degradation efficiency in a compost fermentation process.

Waste oil treatment was attempted using a compost fermentation process. To develop a simple method for waste oil treatment, cheap and simple materials were used as compost materials. The fermentation experiment was performed using a domestic composter to determine the optimum conditions of the fermentation. Adjustment of the pH value during the compost fermentation was also important for progression of the oil degradation. When the pH value was not controlled, the pH value decreased quickly and reached about 2 and the oil degradation was stopped. Adding caustic lime to the raw materials caused the pH value of the compost to stabilize at approximately 7. The addition of a nitrogen source had a large effect on oil degradation during the compost fermentation. The optimum value of the C N ratio of the raw materials with pH control was between 10 and 40. When the C N ratio of the materials was adjusted to 10, 20, and 40, the rate constants for oil degradation were very similar. The rate constants for NH4+ consumption were also similar. Oil degradation efficiency reached 83.5% relative to the initial oil content in the compost materials. Repeated batch operation of the compost fermentation was carried out and the compost system could maintain good efficiency for oil degradation over several repeated batch operations. Finally, the compost system was applied to the treatment of recalled mayonnaise, with favorable results being obtained.

Journal Article↗
PubMedDate not supplied

[Study of nutrition and health claims on labelling of fermented milk products].

BACKGROUND: The consumption of fermented milk products in Spain has been increased for the last 40 years. In addition to yogurt, new varieties of milk products fermented by bifidobacteria or other Lactobacillus species have been introduced. The nutritional importance of these products, together with the likely beneficial effects of the fermentative strains, has propitiated labelling with nutritinal and health claims. Present regulations do not specifically regulate these wordings and a proposal for a European Regulation for standardization of these claims is currently under elaboration. OBJECTIVES: To study the nutrition and health claims on labelling of fermented milk products taking into account current legislation, the proposal for a European Regulation and the related literature. To compare labelling on yogurt with that of other fermented milk products, in relation to these claims. RESULTS: Ninety-four percent of the studied labelling has nutritional information. Nutritional claims have ben found on 38%, of which 20% have mentioned fat content, 12% calcium content, although 26% have less than 15% of the RDA, 7% mention dietary fiber content. Health claims has been presented in 32% of the studied labelling. CONCLUSIONS: Health claims have been more frequently found in fermented milk products other than yogurt, most of them mentioning the prebiotic or probiotic properties. A lack of information to consumers has been observed concerning the necessary amounts to be consumed and the real benefit provided by the product. Nutrition claims in products with normal content of certaint nutrients have been found; this fact might create confusion as regards to really enriches foods.

Cultured Milk Products↗
PubMed2026

Metagenomic Insights into Microbial Assembly and Key Metabolic Genes Driving Flavor Formation in Spontaneously Fermented Zhejiang Rosy Vinegar.

The spontaneous fermentation of Zhejiang rosy vinegar (ZRV) is driven by environmental microbiota, but the processes underlying its flavor formation remain poorly understood. Using metagenomic sequencing, we investigated microbial community assembly, environmental drivers, and metabolic networks during industrial-scale ZRV fermentation. Acetic acid dominated the final organic acids. Community assembly shifted toward deterministic selection with rising acidity, with a slight rebound of stochastic processes in the late stage (R2 values of 0.442 and 0.346 for bacteria and fungi, respectively). Mantel tests confirmed that environmental factors significantly regulated microbial assembly. Co-occurrence networks grew more complex, with positive interactions accounting for 85.24% (bacteria) and 90.10% (fungi) in the late stage. Key genes (ldh, gapA, pgk) from Acetobacter pasteurianus and Lactobacillus acetotolerans dominated late-stage fermentation, while genes (adhP, SDH) from Aspergillus oryzae and Saccharomyces cerevisiae supported early- and mid-stage fermentation. These findings elucidate microbiota-driven metabolic pathways in ZRV, supporting the fermentation window optimization and industrial vinegar quality standardization.

Acetic Acid↗
PubMed2026

Genomic signatures of dairy adaptation in Saccharomyces cerevisiae from traditional Yaghnob goat-cheese fermentation.

The growing interest in studying Saccharomyces cerevisiae strains from previously unexplored niches is greatly expanding our understanding of this yeast's ecology and evolution. While strains involved in alcoholic fermentation are the most studied, S. cerevisiae has also been isolated from milk fermentations and their products, suggesting a potential evolutionary specialization for dairy environments. These fermentations are characterized by the predominant presence of lactose, a carbon source that S. cerevisiae cannot metabolize directly but can exploit through the enzymatic activity of co-occurring microorganisms that convert lactose into fermentable substrates, such as glucose and galactose. In this study, we analyzed S. cerevisiae strains isolated from an unexplored and remote niche: traditional goat fermented milk produced by the Yaghnob people, an ethnically and geographically partly isolated population living in the Upper Zarafshan area of the Republic of Tajikistan. Comparative analyses with published S. cerevisiae genomes positioned the Yaghnob strains at the base of the phylogenetic dairy clade. These strains revealed distinctive coding sequences and strain-specific single-nucleotide variants present in all Yaghnob strains but absent from the other 1,053 strains analyzed. Further investigation of variants in key genes involved in galactose metabolism provided insights into the genomic and protein-level evolution of Yaghnob strains, uncovering unique genomic signatures of adaptation to the dairy environment.

Saccharomyces cerevisiae↗
PubMed1964

2-KETOGLUCONATE FERMENTATION BY STREPTOCOCCUS FAECALIS.

Goddard, J. L. (University of Oklahoma School of Medicine, Oklahoma City), and J. R. Sokatch. 2-Ketogluconate fermentation by Streptococcus faecalis. J. Bacteriol. 87:844-851. 1964.-Streptococcus faecalis 10Cl did not grow with 2-ketogluconate alone as an energy source, but did grow when gluconate was added. More growth was obtained than could be accounted for by the gluconate alone. The requirement for gluconate in the stimulation of growth on 2-ketogluconate was found to be stoichiometric, not catalytic. Glucose did not replace gluconate in this phenomenon, apparently owing to the repression of the 2-ketogluconate pathway by glucose. Resting cells grown on a combination of gluconate and 2-ketogluconate did ferment 2-ketogluconate without added gluconate. Fermentation balance studies with resting cells detected the following products in moles (per mole of 2-ketogluconate): carbon dioxide, 0.98; lactic acid, 0.19; formic acid, 1.42; acetic acid, 0.70; and ethanol, 0.42. 2-Ketogluconate-1-C(14) and -2-C(14) were prepared and fermented. The data were interpreted to show that 90% of the substrate was decarboxylated to carbon dioxide and pentose phosphate. Pentose phosphate was then fermented to pyruvate through the sedoheptulose diphosphate variation of the pentose phosphate pathway found in this organism. The other 10% of the substrate was converted to pyruvate by way of the Entner-Doudoroff pathway. Calculations of the energy available by the above combination of pathways indicated that about 2.3 moles of adenosine triphosphate per mole of 2-ketogluconate could be obtained if the energy available in acetate formation is conserved through the acetokinase reaction.

Acetates↗
PubMed1996

Malolactic fermentation by engineered Saccharomyces cerevisiae as compared with engineered Schizosaccharomyces pombe.

The ability of yeast strains to perform both alcoholic and malolactic fermentation in winemaking was studied with a view to achieving a better control of malolactic fermentation in enology. The malolactic gene of Lactococcus lactis (mleS) was expressed in Saccharomyces cerevisiae and Schizosaccharomyces pombe. The heterologous protein is expressed at a high level in cell extracts of a S. cerevisiae strain expressing the gene mleS under the control of the alcohol dehydrogenase (ADH1) promoter on a multicopy plasmid. Malolactic enzyme specific activity is three times higher than in L. lactis extracts. Saccharomyces cerevisiae expressing the malolactic enzyme produces significant amounts of L-lactate during fermentation on glucose-rich medium in the presence of malic acid. Isotopic filiation was used to demonstrate that 75% of the L-lactate produced originates from endogenous L-malate and 25% from exogenous L-malate. Moreover, although a small amount of exogenous L-malate was degraded by S. cerevisiae transformed or not by mleS, all the exogenous degraded L-malate was converted into L-lactate via a malolactic reaction in the recombinant strain, providing evidence for very efficient competition of malolactic enzyme with the endogenous malic acid pathways. These results indicate that the sole limiting step for S. cerevisiae in achieving malolactic fermentation is in malate transport. This was confirmed using a different model, S. pombe, which efficiently degrades L-malate. Total malolactic fermentation was obtained in this strain, with most of the L-malate converted into L-lactate and CO2. Moreover, L-malate was used preferentially by the malolactic enzyme in this strain also.

Base Sequence↗
PubMed1999

Yeast vitality during cider fermentation: assessment by energy metabolism.

In an apple juice-based medium, an ethanol-tolerant Australian wine-yeast used for cider manufacture produced more than 10% ethanol over a 5 week period. Growth of the inoculum (10(6) organisms ml(-1)) occurred to a population of 3.1 x 10(7) ml(-1) during the first few days; at the end of the fermentation only 5 x 10(5) yeasts ml(-1) could be recovered as colony-forming units on plates. Respiratory and fermentative activities were measured by mass spectrometric measurements (O2 consumption and CO2 and ethanol production) of washed yeast suspensions taken from the cider fermentation at intervals. Both endogenous and glucose-supported energy-yielding metabolism declined, especially during the first 20 days. Levels of adenine nucleotides also showed decreases after day 1, as did adenylate energy charge, although in a prolonged (16.5 week) fermentation the lowest value calculated was 0.55. AMP was released into the medium. 31P-NMR spectra showed that by comparison with aerobically grown yeast, that from the later stages of the cider fermentation showed little polyphosphate. However, as previously concluded from studies of 'acidification power' and fluorescent oxonol dye exclusion (Dinsdale et al., 1995), repitching of yeast indicated little loss of viability despite considerable loss of vitality.

Adenine Nucleotides↗
PubMed2000

Tarhana as a traditional Turkish fermented cereal food. Its recipe, production and composition.

As a fermented product tarhana is the dry form of yogurt-cereal mixture and represents an important part of the diets of many people in Turkey. It is prepared by mixing wheat flour, yogurt, yeast and a variety of cooked vegetables (tomatoes, onions, green pepper etc.), salt, and spices (mint, paprika) followed by fermentation for one to seven days. Generally one part yogurt is mixed with two parts of wheat flour (w/w). In commercial production there are two methods for tarhana making. First method is called straight method and ingredients in the recipe is mixed and kneaded, fermented, dried and finally sieved. Second method is called sour dough method that contains three steps, each one has a different recipe. Throughout fermentation lactic acid bacteria and yeast give the characteristic taste and flavour of tarhana by producing lactic acid, ethanol, carbondioxide and some other organic compounds. Organic acids composed in fermentation period lower the pH (3.4-4.2), and low moisture content (6-10%) is a poor medium for pathogens and spoilage organisms. The nutrient content of tarhana depends upon yogurt and flour ratios as well as some other ingredients, and it is also considered to be a useful high-protein dietary supplement with average 15% protein content. Addition of set yogurt due to high dry matter content and baker's yeast increase protein content and enhances it's amino acid composition.

Animals↗
PubMed2001

Similarity of the Escherichia coli proteome upon completion of different biopharmaceutical fermentation processes.

A comprehensive view of the physiological state of Escherichia coli cells at the completion of fermentation processes for biopharmaceutical production was attained via two-dimensional gel electrophoretic analysis of cellular proteins. For high cell density fermentations in which phosphate is depleted to induce recombinant protein expression from the alkaline phosphatase promoter, proteome analysis confirms that phosphate limitation occurs. Known phosphate starvation inducible proteins are observed at high levels; these include the periplasmic phosphate binding protein and the periplasmic phosphonate binding protein. The phn (EcoK) locus of these E. coli K-12 strains remains cryptic, as demonstrated by failure to grow with phosphonate as the sole phosphorus source. Proteome analysis also provided evidence that cells utilize alternative carbon and energy sources during these fermentation processes. To address regulatory issues in the biopharmaceutical industry, comparative electrophoretic analyses were conducted on a qualitative basis for four different fermentation processes. Using this approach, the protein profiles for these processes were found to be highly similar, with the vast majority (85-90%) of proteins detected in all profiles. The observed similarity in proteomes suggests that multiproduct host cell protein immunoassays are a feasible means of quantifying host-derived polypeptides from a variety of biopharmaceutical fermentation processes.

Biopharmaceutics↗