Microbial ecology and starter culture technology in coffee processing.

PubMed

Vinícius de Melo Pereira, Gilberto; Soccol, Vanete Thomaz; Brar, Satinder Kaur; Neto, Ensei; Soccol, Carlos Ricardo

2017-09-02

Coffee has been for decades the most commercialized food product and most widely consumed beverage in the world, with over 600 billion cups served per year. Before coffee cherries can be traded and processed into a final industrial product, they have to undergo postharvest processing on farms, which have a direct impact on the cost and quality of a coffee. Three different methods can be used for transforming the coffee cherries into beans, known as wet, dry, and semi-dry methods. In all these processing methods, a spontaneous fermentation is carried out in order to eliminate any mucilage still stuck to the beans and helps improve beverage flavor by microbial metabolites. The microorganisms responsible for the fermentation (e.g., yeasts and lactic acid bacteria) can play a number of roles, such as degradation of mucilage (pectinolytic activity), inhibition of mycotoxin-producing fungi growth, and production of flavor-active components. The use of starter cultures (mainly yeast strains) has emerged in recent years as a promising alternative to control the fermentation process and to promote quality development of coffee product. However, scarce information is still available about the effects of controlled starter cultures in coffee fermentation performance and bean quality, making it impossible to use this technology in actual field conditions. A broader knowledge about the ecology, biochemistry, and molecular biology could facilitate the understanding and application of starter cultures for coffee fermentation process. This review provides a comprehensive coverage of these issues, while pointing out new directions for exploiting starter cultures in coffee processing.

Control of Biogenic Amines in Fermented Sausages: Role of Starter Cultures

PubMed Central

Latorre-Moratalla, M.L.; Bover-Cid, Sara; Veciana-Nogués, M.T.; Vidal-Carou, M.C.

2012-01-01

Biogenic amines show biological activity and exert undesirable physiological effects when absorbed at high concentrations. Biogenic amines are mainly formed by microbial decarboxylation of amino acids and thus are usually present in a wide range of foods, fermented sausages being one of the major biogenic amine sources. The use of selected starter cultures is one of the best technological measures to control aminogenesis during meat fermentation. Although with variable effectiveness, several works show the ability of some starters to render biogenic amine-free sausages. In this paper, the effect of different starter culture is reviewed and the factors determining their performance discussed. PMID:22586423

Evaluation of autochthonous micrococcus strains as starter cultures for the production of Kedong sufu.

PubMed

Feng, Z; Huang, S; Ai, Z W; Zhang, M; Zhai, S; Chen, X

2016-03-01

The technological properties of 22 micrococcus strains from traditional fermented Kedong sufu were evaluated in order to develop autochthonous starter cultures. The proteolytic, autolytic and lipolytic activity, salt tolerance, production and degradation of the biogenic amines of six Micrococcus luteus, nine Kocuria kristinae and seven Kocuria rosea were evaluated. The results indicated that these micrococcus strains exhibited a certain technological diversity, and the results also indicated the best properties to be used in mixed starter cultures. Based on the above findings, two sets of autochthonous starters were formulated. Considering the physicochemical properties and sensory characteristics of sufu, the maturation period of sufu was shortened by 30 days. The profiles of free amino acids and peptides partly revealed the mechanism of sensory quality and shorter ripening time of sufu manufactured using autochthonous mixed starters. Compared to back-slopping fermentation, sufu manufactured with selected autochthonous starter cultures exhibited lower levels of total biogenic amines. The selected strains could be used as starter to avoid the accumulation of high concentrations of biogenic amines while also maintaining typical sensory characteristics and preserving the autochthonous strains of the traditional Kedong sufu. The maturation times of Kedong sufu were shortened by 30 days with application of the autochthonous starter. Autochthonous mixed starters can reduce the generation of biogenic amines, speed up the sufu maturation process and preserve typical sensory quality. Furthermore, the rotation of two sets of mixed starter cultures can effectively resist phage attack during the production of sufu. © 2015 The Society for Applied Microbiology.

Production and monomer composition of exopolysaccharides by yogurt starter cultures.

PubMed

Frengova, G I; Simova, E D; Beshkova, D M; Simov, Z I

2000-12-01

As components of starter cultures for Bulgarian yogurt, Streptococcus salivarius subsp. thermophilus and Lactobacillus delbrueckii subsp. bulgaricus revealed extensive exopolysaccharide (EPS) production activity when cultivated in whole cow's milk. The polymer-forming activity of thermophilic streptococci was lower (230-270 mg EPS/L) than that of the lactobacilli (400-540 mg EPS/L). Mixed cultures stimulated EPS production in yogurt manufacture, and a maximum concentration of 720-860 mg EPS/L was recorded after full coagulation of milk. The monomer structure of the exopolysaccharides formed by the yogurt starter cultures principally consists of galactose and glucose (1:1), with small amounts of xylose, arabinose, and/or mannose.

Enhancement of gamma-aminobutyric acid (GABA) levels using an autochthonous Lactobacillus futsaii CS3 as starter culture in Thai fermented shrimp (Kung-Som).

PubMed

Sanchart, Chatthaphisuth; Rattanaporn, Onnicha; Haltrich, Dietmar; Phukpattaranont, Pimpimol; Maneerat, Suppasil

2017-08-01

Gamma-aminobutyric acid (GABA) is a non-proteinogenic amino acid, which has a variety of well-characterized beneficial physiological functions. In order to improve GABA levels and the fermentation process of Thai fermented shrimp (Kung-Som), autochthonous Lactobacillus futsaii CS3 was inoculated as a starter culture into Kung-Som, and its effects on the quality of Kung-Som were studied. The optimal conditions for GABA production in Kung-Som as obtained by response surface methodology (RSM) using a central composite design (CCD) were an inoculum size of roughly 10 7 CFU/g (X 1 ) of L. futsaii cells together with the addition of 0.5% (w/w) monosodium glutamate (MSG) (X 2 ), resulting in maximum GABA levels of 10,500 mg per kg fresh product. Under these optimized conditions, the experimental GABA content of Kung-Som with an added starter culture was up to four times higher than that of the control (without starter culture) or commercial Kung-Som products (10,120 mg/kg product). Kung-Som produced by inoculation with L. futsaii CS3 but without addition of MSG showed a considerably increased GABA content of 7790 mg/kg compared to the control. Fermentation time was reduced to less than 1 week for these samples compared to the control batches, which took up to 19 days. Polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) revealed that L. futsaii CS3 remained prominently throughout the Kung-Som fermentation, and that lactic acid bacteria (LAB) rapidly dominated the total microflora because of this inoculation with L. futsaii CS3. Kung-Som samples with starter culture were accepted as well as commercial ones by 30 panelists (p > 0.05). In conclusion, L. futsaii CS3 is a good starter culture for GABA production, resulting in, improved microbiological safety as well as reduced fermentation time.

Effects of yogurt starter cultures on the survival of Lactobacillus acidophilus.

PubMed

Ng, Elizabeth W; Yeung, Marie; Tong, Phillip S

2011-01-31

Recognized to confer health benefits to consumers, probiotics such as Lactobacillus acidophilus are commonly incorporated into fermented dairy products worldwide; among which yogurt is a popular delivery vehicle. To materialize most of the putative health benefits associated with probiotics, an adequate amount of viable cells must be delivered at the time of consumption. However, the loss in their viabilities during refrigerated storage has been demonstrated previously. This study focused on the effects of yogurt starter cultures on the survival of five strains of L. acidophilus, with emphases on low pH and acid production. Differential survival behavior between L. acidophilus strains was further analyzed. To this end, viable cell counts of L. acidophilus were determined weekly during 4°C storage in various types of yogurts made with Streptococcus thermophilus alone, L. delbrueckii ssp. bulgaricus alone, both species of the starter cultures, or glucono-delta-lactone (GDL). All yogurt types, except for pasteurized yogurts, were co-fermented with L. acidophilus. Yogurt filtrate was analyzed for the presence of any inhibitory substance and for the amount of hydrogen peroxide. Multiplication of L. acidophilus was not affected by the starter cultures as all strains reached high level on day 0 of the storage period. Throughout the 28-day storage period, cell counts of L. acidophilus PIM703 and SBT2062 remained steady (~6 × 10(7)CFU/g) in yogurts made with both starter cultures, whereas those of ATCC 700396 and NCFM were reduced by a maximum of 3 and 4.6 logs, respectively. When starter cultures were replaced by GDL, all strains survived well, suggesting that a low pH was not a critical factor dictating their survival. In addition, the filtrate collected from yogurts made with starter cultures appeared to have higher inhibitory activities against L. acidophilus than that made with GDL. The presence of viable starter cultures was necessary to adversely affect the

The effect of spices and manganese on meat starter culture activity.

PubMed

Coventry, M J; Hickey, M W

1993-01-01

Three species, two proprietary spice blends and six starter preparations used in commercial salami manufacture were analysed for manganese and magnesium content. A mettwurst spices blend showed the highest levels of manganese (0·77 ppm expressed as effective product level assuming a 1% spice content) while mild and hot paprika and milano blend contained levels of manganese 1 4 - 1 3 lower. Magnesium levels for spices ranged from 3·14 to 25·81 ppm. Only two of the six meat starter cultures showed high levels of manganese (7·77 and 16·12 ppm as effective product level based on inoculation rate) while magnesium levels for all starter cultures did not exceed 0·37 ppm. The pH of salami products made with starter cultures containing no added manganese lagged behind that of products made with added mangenese (5 ppm) by 0·2 pH units at 48 h. The effect of manganese ions on the fermentation rate of starter bacteria was studied further in a salami model system, in the absence and presence of added spices. The mettwurst blend produced greatest stimulation and the milano the least. A level of 1·2 ppm of added manganese was sufficient to achieve an optimal (< 4·9 pH units within 48 h) fermentation in the presence of all five spices tested in the salami model system. Copyright © 1993. Published by Elsevier Ltd.

Whey-cheese production using freeze-dried kefir culture as a starter.

PubMed

Dimitrellou, D; Kourkoutas, Y; Banat, I M; Marchant, R; Koutinas, A A

2007-10-01

The aim of the present study was to evaluate the use of a freeze-dried kefir culture in the production of a novel type of whey-cheese similar to traditional Greek Myzithra-cheese, to achieve improvement of the quality characteristics of the final product and the extension of shelf-life. The use of kefir culture as a starter led to increased lactic acid concentrations and decreased pH values in the final product compared with whey-cheese without starter culture. The effect of the starter culture on production of aroma-related compounds responsible for cheese flavour was also studied using the solid phase microextraction gas chromatography/mass spectrometry technique. Spoilage in unsalted kefir-whey-cheese was observed on the thirteenth and the twentieth day of preservation at 10 and 5 degrees C, respectively, while the corresponding times for unsalted whey-cheese preservation were 11 and 14 days. The cheeses produced were characterized as high-quality products during the preliminary sensory evaluation. An indication of increased preservation time was attributed to the freeze-dried kefir culture, which also seemed to suppress growth of pathogens. The results suggested the use of kefir culture as a means to extend the shelf-life of dairy products with reduced or no salt content.

Sensory quality of Camembert-type cheese: Relationship between starter cultures and ripening molds.

PubMed

Galli, Bruno Domingues; Martin, José Guilherme Prado; da Silva, Paula Porrelli Moreira; Porto, Ernani; Spoto, Marta Helena Fillet

2016-10-03

Starter cultures and ripening molds used in the manufacture of moldy cheese aimed at obtaining characteristic flavors and textures considerably differ among dairy industries. Thus, the study of variables inherent to the process and their influence on sensory patterns in cheese can improve the standardization and control of the production process. The aim of this work was to study the influence of three different variables on the sensory quality of Camembert-type cheese: type of lactic bacteria, type of ripener molds and inoculation method. Batches of Camembert-type cheese were produced using O or DL-type mesophilic starter culture, ripened with Penicillium camemberti or Penicillium candidum and mold inoculation was made directly into the milk or by spraying. All batches were sensorially evaluated using Quantitative Descriptive Analysis (QDA) with panelists trained for various attributes. Among the combinations analyzed, those resulting in more typical Camembert-type cheese were those using O-type mesophilic starter culture and P. candidum maturation mold directly applied into the milk or sprayed and those using DL-type mesophilic starter and P. camemberti ripener mold applied by surface spraying. These results demonstrate, therefore, that the combination of different ripener molds, inoculation methods and starter cultures directly influences the sensory quality of Camembert-type cheese, modifying significantly its texture, appearance, aroma and taste. Copyright © 2016 Elsevier B.V. All rights reserved.

Effects of inoculation of commercial starter cultures on the quality and histamine accumulation in fermented sausages.

PubMed

Wang, Xinhui; Ren, Hongyang; Wang, Wei; Zhang, Yin; Bai, Ting; Li, Junxia; Zhu, Wenyou

2015-02-01

To meet the requirements of high-quality safe products, starter cultures are used to produce fermented sausages. The effects of 3 commercial starter cultures, namely SM-194, T-SPX, and SM-181, on histamine accumulation and quality parameters including microbial quality, pH, water activity, and total volatile base nitrogen, as well as the color and texture properties, were evaluated during the fermentation and ripening of fermented sausages. Although initial counts of Escherichia coli, Enterobacteriaceae, and Pseudomonas were similar in the 4 batches, the growth of these microorganisms was significantly inhibited (P < 0.05) in batches SM-194, T-SPX, and SM-181 throughout the fermentation and ripening period. The counts of E. coli, Enterobacteriaceae, and Pseudomonas increased to maximum levels of 3.89, 4.41, and 5.15 log10 colony forming units/g in the control sausages, respectively. At the end of ripening, the levels of histamine were 8.85, 0.32, 7.82, and 3.18 mg/kg for batches C, SM-194, T-SPX, and SM-181, respectively. The results revealed that commercial starter cultures, particularly starter cultures SM-194 and SM-181, made a great contribution to histamine reduction. In addition, batches inoculated with starter cultures showed a stronger acidification and lower level of total volatile base nitrogen than the control sample during production (P < 0.05). In conclusion, it seems that the inoculation of commercial starter cultures, particularly starter cultures SM-194 and SM-181, contributes to improving microbial quality, hygienic quality and food safety of fermented sausages. © 2015 Institute of Food Technologists®

Lactococcus lactis Diversity in Undefined Mixed Dairy Starter Cultures as Revealed by Comparative Genome Analyses and Targeted Amplicon Sequencing of epsD.

PubMed

Frantzen, Cyril A; Kleppen, Hans Petter; Holo, Helge

2018-02-01

Undefined mesophilic mixed (DL) starter cultures are used in the production of continental cheeses and contain unknown strain mixtures of Lactococcus lactis and leuconostocs. The choice of starter culture affects the taste, aroma, and quality of the final product. To gain insight into the diversity of Lactococcus lactis strains in starter cultures, we whole-genome sequenced 95 isolates from three different starter cultures. Pan-genomic analyses, which included 30 publically available complete genomes, grouped the strains into 21 L. lactis subsp . lactis and 28 L. lactis subsp. cremoris lineages. Only one of the 95 isolates grouped with previously sequenced strains, and the three starter cultures showed no overlap in lineage distributions. The culture diversity was assessed by targeted amplicon sequencing using purR , a core gene, and epsD , present in 93 of the 95 starter culture isolates but absent in most of the reference strains. This enabled an unprecedented discrimination of starter culture Lactococcus lactis and revealed substantial differences between the three starter cultures and compositional shifts during the cultivation of cultures in milk. IMPORTANCE In contemporary cheese production, standardized frozen seed stock starter cultures are used to ensure production stability, reproducibility, and quality control of the product. The dairy industry experiences significant disruptions of cheese production due to phage attacks, and one commonly used countermeasure to phage attack is to employ a starter rotation strategy, in which two or more starters with minimal overlap in phage sensitivity are used alternately. A culture-independent analysis of the lactococcal diversity in complex undefined starter cultures revealed large differences between the three starter cultures and temporal shifts in lactococcal composition during the production of bulk starters. A better understanding of the lactococcal diversity in starter cultures will enable the development of

Safety improvement and preservation of typical sensory qualities of traditional dry fermented sausages using autochthonous starter cultures.

PubMed

Talon, Régine; Leroy, Sabine; Lebert, Isabelle; Giammarinaro, Philippe; Chacornac, Jean-Paul; Latorre-Moratalla, Mariluz; Vidal-Carou, Carmen; Zanardi, Emanuela; Conter, Mauro; Lebecque, Annick

2008-08-15

Traditional dry fermented sausages are manufactured without addition of starter cultures in small-scale processing units, their fermentation relying on indigenous microflora. Characterisation and control of these specific bacteria are essential for the sensory quality and the safety of the sausages. The aim of this study was to develop an autochthonous starter culture that improves safety while preserving the typical sensory characteristics of traditional sausages. An autochthonous starter composed of Lactobacillus sakei, Staphylococcus equorum and Staphylococcus succinus isolated from a traditional fermented sausage was developed. These strains were tested for their susceptibility to antibiotics and their production of biogenic amines. This starter was evaluated in situ at the French traditional processing unit where the strains had been isolated. Effects of the autochthonous starter were assessed by analysing the microbial, physico-chemical, biochemical and sensory characteristics of the sausages. Inoculation with the chosen species was confirmed using known species-specific PCR assays for L. sakei and S. equorum and a species-specific PCR assay developed in this study for S. succinus. Strains were monitored by pulse-field gel electrophoresis typing. Addition of autochthonous microbial starter cultures improved safety compared with the traditional natural fermentation of sausages, by inhibiting the pathogen Listeria monocytogenes, decreasing the level of biogenic amines and by limiting fatty acid and cholesterol oxidation. Moreover, autochthonous starter did not affect the typical sensory quality of the traditional sausages. This is the first time to our knowledge that selection, development and validation in situ of autochthonous starter cultures have been carried out, and also the first time that S. equorum together with S. succinus have been used as starter cultures for meat fermentation. Use of autochthonous starter cultures is an effective tool for limiting

Antimicrobial susceptibility of starter culture bacteria used in Norwegian dairy products.

PubMed

Katla, A K; Kruse, H; Johnsen, G; Herikstad, H

2001-07-20

Commercial starter culture bacteria are widely used in the production of dairy products and could represent a potential source for spread of genes encoding resistance to antimicrobial agents. To learn more about the antimicrobial susceptibility of starter culture bacteria used in Norwegian dairy products, a total of 189 isolates of lactic acid bacteria were examined for susceptibility to ampicillin, penicillin G, cephalothin, vancomycin, bacitracin, gentamicin, streptomycin, erythromycin, tetracycline, chloramphenicol, quinupristin/dalfopristin, ciprofloxacin, trimethoprim and sulphadiazine using Etest for MIC determination. Most of the isolates (140) originated from 39 dairy products (yoghurt, sour cream, fermented milk and cheese), while 49 were isolated directly from nine commercial cultures. The bacteria belonged to the genera Lactobacillus, Lactococcus, Leuconostoc and Streptococcus. Only one of the 189 isolates was classified as resistant to an antimicrobial agent included in the study. This isolate, a lactobacillus, was classified as high level resistant to streptomycin. The remaining isolates were not classified as resistant to the antimicrobial agents included other than to those they are known to have a natural reduced susceptibility to. Thus, starter culture bacteria in Norwegian dairy products do not seem to represent a source for spread of genes encoding resistance to antimicrobial agents.

Breeding Strategy To Generate Robust Yeast Starter Cultures for Cocoa Pulp Fermentations

PubMed Central

Meersman, Esther; Steensels, Jan; Paulus, Tinneke; Struyf, Nore; Saels, Veerle; Mathawan, Melissa; Koffi, Jean; Vrancken, Gino

2015-01-01

Cocoa pulp fermentation is a spontaneous process during which the natural microbiota present at cocoa farms is allowed to ferment the pulp surrounding cocoa beans. Because such spontaneous fermentations are inconsistent and contribute to product variability, there is growing interest in a microbial starter culture that could be used to inoculate cocoa pulp fermentations. Previous studies have revealed that many different fungi are recovered from different batches of spontaneous cocoa pulp fermentations, whereas the variation in the prokaryotic microbiome is much more limited. In this study, therefore, we aimed to develop a suitable yeast starter culture that is able to outcompete wild contaminants and consistently produce high-quality chocolate. Starting from specifically selected Saccharomyces cerevisiae strains, we developed robust hybrids with characteristics that allow them to efficiently ferment cocoa pulp, including improved temperature tolerance and fermentation capacity. We conducted several laboratory and field trials to show that these new hybrids often outperform their parental strains and are able to dominate spontaneous pilot scale fermentations, which results in much more consistent microbial profiles. Moreover, analysis of the resulting chocolate showed that some of the cocoa batches that were fermented with specific starter cultures yielded superior chocolate. Taken together, these results describe the development of robust yeast starter cultures for cocoa pulp fermentations that can contribute to improving the consistency and quality of commercial chocolate production. PMID:26150457

Use of autochthonous Pediococcus acidilactici and Staphylococcus vitulus starter cultures in the production of "chorizo" in 2 different traditional industries.

PubMed

Casquete, Rocío; Benito, María J; Martín, Alberto; Ruiz-Moyano, Santiago; Aranda, Emilio; Córdoba, María G

2012-01-01

The present study determined how the different ripening conditions affected the growth and development of 3 autochthonous starter cultures, and the physico-chemical and sensory characteristics of chorizo. Each of 3 strains of Pediococcus acidilactici (MC184, MS198, and MS200) and one of Staphylococcus vitulus (RS34) were associated to prepare the starter cultures, P184S34, P198S34, and P200S34. Then, chorizo was prepared following 2 manufacturing procedures. The autochthonous starter cultures were able to compete and colonize the sausages in both ripening procedures. The use of the starter cultures showed evident differences by the texture analysis, with the control batches being generally tougher than the starter culture batches. Also, the highest biogenic amine (BA) levels were found in control batches and the lowest in P200S34 batches. While the use of these starter cultures does not change the sensory characteristics of these traditional fermented sausages, it improves their homogeneity and safety, except for P184S34 batch in which more BAs are detected in industry 2. The 3 autochthonous starter cultures selected could be used in traditional industries because they are able to compete well and colonize the dry fermented sausages "chorizo." The use of these starter cultures improves the texture and homogeneity of traditional fermented sausages. Biogenic amines decreased in the starter cultures batches improving the safety. © 2011 Institute of Food Technologists®

Inoculation of starter cultures in a semi-dry coffee (Coffea arabica) fermentation process.

PubMed

Evangelista, Suzana Reis; Miguel, Maria Gabriela da Cruz Pedrozo; Cordeiro, Cecília de Souza; Silva, Cristina Ferreira; Pinheiro, Ana Carla Marques; Schwan, Rosane Freitas

2014-12-01

The aim of this study was to evaluate the use of yeasts as starter cultures in coffee semi-dry processing. Arabica coffee was inoculated with one of the following starter cultures: Saccharomyces cerevisiae UFLA YCN727, S. cerevisiae UFLA YCN724, Candida parapsilosis UFLA YCN448 and Pichia guilliermondii UFLA YCN731. The control was not inoculated with a starter culture. Denaturing gradient gel electrophoresis (DGGE) was used to assess the microbial population, and organic acids and volatile compounds were quantified by HPLC and HS-SPME/GC, respectively. Sensory analyses were evaluated using the Temporal Dominance of Sensations (TDS). DGGE analysis showed that the inoculated yeasts were present throughout the fermentation. Other yeast species were also detected, including Debaryomyces hansenii, Cystofilobasidium ferigula and Trichosporon cavernicola. The bacterial population was diverse and was composed of the following genera: Weissella, Leuconostoc, Gluconobacter, Pseudomonas, Pantoea, Erwinia and Klebsiella. Butyric and propionic acids, were not detected in any treatment A total of 47 different volatiles compounds have been identified. The coffee inoculated with yeast had a caramel flavor that was not detected in the control, as assessed by TDS. The use of starter cultures during coffee fermentation is an interesting alternative for obtaining a beverage quality with distinctive flavor. Copyright © 2014 Elsevier Ltd. All rights reserved.

Breeding Strategy To Generate Robust Yeast Starter Cultures for Cocoa Pulp Fermentations.

PubMed

Meersman, Esther; Steensels, Jan; Paulus, Tinneke; Struyf, Nore; Saels, Veerle; Mathawan, Melissa; Koffi, Jean; Vrancken, Gino; Verstrepen, Kevin J

2015-09-01

Cocoa pulp fermentation is a spontaneous process during which the natural microbiota present at cocoa farms is allowed to ferment the pulp surrounding cocoa beans. Because such spontaneous fermentations are inconsistent and contribute to product variability, there is growing interest in a microbial starter culture that could be used to inoculate cocoa pulp fermentations. Previous studies have revealed that many different fungi are recovered from different batches of spontaneous cocoa pulp fermentations, whereas the variation in the prokaryotic microbiome is much more limited. In this study, therefore, we aimed to develop a suitable yeast starter culture that is able to outcompete wild contaminants and consistently produce high-quality chocolate. Starting from specifically selected Saccharomyces cerevisiae strains, we developed robust hybrids with characteristics that allow them to efficiently ferment cocoa pulp, including improved temperature tolerance and fermentation capacity. We conducted several laboratory and field trials to show that these new hybrids often outperform their parental strains and are able to dominate spontaneous pilot scale fermentations, which results in much more consistent microbial profiles. Moreover, analysis of the resulting chocolate showed that some of the cocoa batches that were fermented with specific starter cultures yielded superior chocolate. Taken together, these results describe the development of robust yeast starter cultures for cocoa pulp fermentations that can contribute to improving the consistency and quality of commercial chocolate production. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Species diversity and metabolic impact of the microbiota are low in spontaneously acidified Belgian sausages with an added starter culture of Staphylococcus carnosus.

PubMed

Janssens, M; Myter, N; De Vuyst, L; Leroy, F

2012-04-01

Quality of fermented sausages is affected by acidifying lactic acid bacteria (LAB) and colour- and flavour-promoting coagulase-negative staphylococci (CNS), whether or not used as starter culture. Artisan fermented sausages are often perceived as superior to industrial variants, partially because of the specific microbiota due to spontaneous acidification, which may be considered as an artisan characteristic. Therefore, two kinds of spontaneously acidified Belgian sausages were prepared (Belgian-type salami and Boulogne sausage), but with addition of a Staphylococcus carnosus culture. The Belgian-type salami was made from pork and beef, whereas the Boulogne sausage contained pork and horse meat. In all cases, Lactobacillus sakei was the dominant LAB species present on the raw materials and during fermentation, whereas enterococci remained present in the background. Enterobacteriaceae vanished after fermentation. The CNS species diversity on the raw materials was large and differed between the pork, beef, and horse meat. Nevertheless, this species diversity was annihilated during fermentation by the added S. carnosus culture. The volatiles fraction was mainly composed of aldehydes that originated from lipid oxidation and spices-derived compounds. Aromatic compounds that are typically associated to CNS activity, such as end-products from the metabolism of branched-chain amino acids, were not present in the Belgian-type salami and only marginally present in the Boulogne sausage. In conclusion, spontaneous acidification of Belgian-type fermented sausages leads to dominance of L. sakei and is no guarantee for bacterial contribution to the aroma profile when S. carnosus is added as a starter culture. Copyright © 2011 Elsevier Ltd. All rights reserved.

Development of a multiplex real time PCR to detect thermophilic lactic acid bacteria in natural whey starters.

PubMed

Bottari, Benedetta; Agrimonti, Caterina; Gatti, Monica; Neviani, Erasmo; Marmiroli, Nelson

2013-01-01

A multiplex real time PCR (mRealT-PCR) useful to rapidly screen microbial composition of thermophilic starter cultures for hard cooked cheeses and to compare samples with potentially different technological properties was developed. Novel primers directed toward pheS gene were designed and optimized for multiple detection of Lactobacillus helveticus, Lactobacillus delbrueckii, Streptococcus thermophilus and Lactobacillus fermentum. The assay was based on SYBR Green chemistry followed by melting curves analysis. The method was then evaluated for applications in the specific detection of the 4 lactic acid bacteria (LAB) in 29 different natural whey starters for Parmigiano Reggiano cheese production. The results obtained by mRealT-PCR were also compared with those obtained on the same samples by Fluorescence in Situ Hybridization (FISH) and Length-Heterogeneity PCR (LH-PCR). The mRealT-PCR developed in this study, was found to be effective for analyzing species present in the samples with an average sensitivity down to less than 600 copies of DNA and therefore sensitive enough to detect even minor LAB community members of thermophilic starter cultures. The assay was able to describe the microbial population of all the different natural whey starter samples analyzed, despite their natural variability. A higher number of whey starter samples with S. thermophilus and L. fermentum present in their microbial community were revealed, suggesting that these species could be more frequent in Parmigiano Reggiano natural whey starter samples than previously shown. The method was more effective than LH-PCR and FISH and, considering that these two techniques have to be used in combination to detect the less abundant species, the mRealT-PCR was also faster. Providing a single step sensitive detection of L. helveticus, L. delbrueckii, S. thermophilus and L. fermentum, the developed mRealT-PCR could be used for screening thermophilic starter cultures and to follow the presence of

The cocoa bean fermentation process: from ecosystem analysis to starter culture development.

PubMed

De Vuyst, L; Weckx, S

2016-07-01

Cocoa bean fermentation is still a spontaneous curing process to facilitate drying of nongerminating cocoa beans by pulp removal as well as to stimulate colour and flavour development of fermented dry cocoa beans. As it is carried out on farm, cocoa bean fermentation is subjected to various agricultural and operational practices and hence fermented dry cocoa beans of variable quality are obtained. Spontaneous cocoa bean fermentations carried out with care for approximate four days are characterized by a succession of particular microbial activities of three groups of micro-organisms, namely yeasts, lactic acid bacteria (LAB) and acetic acid bacteria (AAB), which results in well-fermented fully brown cocoa beans. This has been shown through a plethora of studies, often using a multiphasic experimental approach. Selected strains of several of the prevailing microbial species have been tested in appropriate cocoa pulp simulation media to unravel their functional roles and interactions as well as in small plastic vessels containing fresh cocoa pulp-bean mass to evaluate their capacity to dominate the cocoa bean fermentation process. Various starter cultures have been proposed for successful fermentation, encompassing both cocoa-derived and cocoa nonspecific strains of (hybrid) yeasts, LAB and AAB, some of which have been implemented on farms successfully. © 2016 The Society for Applied Microbiology.

Identification of potential probiotic starter cultures for Scandinavian-type fermented sausages.

PubMed

Klingberg, Trine Danø; Axelsson, Lars; Naterstad, Kristine; Elsser, Dieter; Budde, Birgitte Bjørn

2005-12-15

Potential probiotic cultures suitable as starter cultures for the Scandinavian-type fermented sausages were identified among strains well-adapted to fermented meats as well as strains originating from a culture collection. From 15 different fermented meat products, 22 strains were isolated as dominant non-starter lactic acid bacteria (NSLAB). The isolates were identified by RAPD, API and sequence analysis of 16S rRNA and showed to be five strains of Lactobacillus sakei, five strains of Lactobacillus farciminis, five strains belonging to the group of Lactobacillus plantarum/pentosus, four strains of Lactobacillus alimentarius, two strains of Lactobacillus brevis and one strain of Lactobacillus versmoldensis. Heterofermentative strains as well as strains not growing at 37 degrees C and not lowering pH below 5.1 in a meat model were excluded leaving 9 strains for further studies. These strains together with 19 strains from a culture collection were evaluated by in vitro methods including survival upon exposure to pH 2.5 or 0.3% oxgall and adhesion to the human colon adenocarcinoma cell line Caco-2 as well as antimicrobial activity against potential pathogens. Strains that fulfilled all the probiotic criteria and showed to be fast acid producers in a meat model included three strains belonging to the group of Lb. plantarum/pentosus (MF1291, MF1298, MF1300) which originated from the dominant NSLAB of fermented meat products. MF1291 and MF 1298 were further identified as Lb. plantarum and MF1300 as Lb. pentosus. The three strains were all successfully applied as starter cultures for the production of fermented sausage. The viable count at the end of the processing period reached high cell numbers (4.7x10(7)-2.9x10(8) cfu/g) and pH of the sausages decreased to pH 4.8-4.9 without any flavour deviation compared to sausage fermented by a commercial meat starter culture.

Chromosomal Diversity in Lactococcus lactis and the Origin of Dairy Starter Cultures

PubMed Central

Kelly, William J.; Ward, Lawrence J. H.; Leahy, Sinead C.

2010-01-01

A large collection of Lactococcus lactis strains, including wild-type isolates and dairy starter cultures, were screened on the basis of their phenotype and the macrorestriction patterns produced from pulsed-field gel electrophoresis (PFGE) analysis of SmaI digests of genomic DNA. Three groups of dairy starter cultures, used for different purposes in the dairy industry, and a fourth group made up of strains isolated from the environment were selected for analysis of their chromosomal diversity using the endonuclease I-CeuI. Chromosome architecture was largely conserved with each strain having six copies of the rRNA genes, and the chromosome size of individual strains ranged between 2,240 and 2,688 kb. The origin of L. lactis strains showed the greatest correlation with chromosome size, and dairy strains, particularly those with the cremoris phenotype, had smaller chromosomes than wild-type strains. Overall, this study, coupled with analysis of the sequenced L. lactis genomes, provides evidence that defined strain dairy starter cultures have arisen from plant L. lactis strains. Adaptation of these strains to the dairy environment has involved loss of functions resulting in smaller chromosomes and acquisition of genes (usually plasmid associated) that facilitate growth in milk. We conclude that dairy starter cultures generally and the industrially used cremoris and diacetylactis phenotype strains in particular comprise a specialized group of L. lactis strains that have been selected to become an essential component of industrial processes and have evolved accordingly, so that they are no longer fit to survive outside the dairy environment. PMID:20847124

Acetic acid bacteria in traditional balsamic vinegar: phenotypic traits relevant for starter cultures selection.

PubMed

Gullo, Maria; Giudici, Paolo

2008-06-30

This review focuses on acetic acid bacteria in traditional balsamic vinegar process. Although several studies are available on acetic acid bacteria ecology, metabolism and nutritional requirements, their activity as well as their technological traits in homemade vinegars as traditional balsamic vinegar is not well known. The basic technology to oxidise cooked grape must to produce traditional balsamic vinegar is performed by the so called "seed-vinegar" that is a microbiologically undefined starter culture obtained from spontaneous acetification of previous raw material. Selected starter cultures are the main technological improvement in order to innovate traditional balsamic vinegar production but until now they are rarely applied. To develop acetic acid bacteria starter cultures, selection criteria have to take in account composition of raw material, acetic acid bacteria metabolic activities, applied technology and desired characteristics of the final product. For traditional balsamic vinegar, significative phenotypical traits of acetic acid bacteria have been highlighted. Basic traits are: ethanol preferred and efficient oxidation, fast rate of acetic acid production, tolerance to high concentration of acetic acid, no overoxidation and low pH resistance. Specific traits are tolerance to high sugar concentration and to a wide temperature range. Gluconacetobacter europaeus and Acetobacter malorum strains can be evaluated to develop selected starter cultures since they show one or more suitable characters.

Table Olive Fermentation Using Starter Cultures with Multifunctional Potential

PubMed Central

Bonatsou, Stamatoula; Tassou, Chrysoula C.; Panagou, Efstathios Z.; Nychas, George-John E.

2017-01-01

Table olives are one of the most popular plant-derived fermented products. Their enhanced nutritional value due to the presence of phenolic compounds and monounsaturated fatty acids makes olives an important food commodity of the Mediterranean diet. However, despite its economic significance, table olive fermentation is mainly craft-based and empirically driven by the autochthonous microbiota of the olives depending on various intrinsic and extrinsic factors, leading to a spontaneous process and a final product of variable quality. The use of microorganisms previously isolated from olive fermentations and studied for their probiotic potential and technological characteristics as starter cultures may contribute to the reduction of spoilage risk resulting in a controlled fermentation process. This review focuses on the importance of the development and implementation of multifunctional starter cultures related to olives with desirable probiotic and technological characteristics for possible application on table olive fermentation with the main purpose being the production of a health promoting and sensory improved functional food. PMID:28555038

Table Olive Fermentation Using Starter Cultures with Multifunctional Potential.

PubMed

Bonatsou, Stamatoula; Tassou, Chrysoula C; Panagou, Efstathios Z; Nychas, George-John E

2017-05-28

Table olives are one of the most popular plant-derived fermented products. Their enhanced nutritional value due to the presence of phenolic compounds and monounsaturated fatty acids makes olives an important food commodity of the Mediterranean diet. However, despite its economic significance, table olive fermentation is mainly craft-based and empirically driven by the autochthonous microbiota of the olives depending on various intrinsic and extrinsic factors, leading to a spontaneous process and a final product of variable quality. The use of microorganisms previously isolated from olive fermentations and studied for their probiotic potential and technological characteristics as starter cultures may contribute to the reduction of spoilage risk resulting in a controlled fermentation process. This review focuses on the importance of the development and implementation of multifunctional starter cultures related to olives with desirable probiotic and technological characteristics for possible application on table olive fermentation with the main purpose being the production of a health promoting and sensory improved functional food.

Classification of Swiss cheese starter and adjunct cultures using Fourier transform infrared microspectroscopy.

PubMed

Prabhakar, V; Kocaoglu-Vurma, N; Harper, J; Rodriguez-Saona, L

2011-09-01

The acceptability of Swiss cheese largely depends on the flavor profile, and strain variations of cheese cultures will affect the final quality. Conventional biochemical methods to identify the cultures at the strain level are time-consuming and expensive, and require skilled labor. Our objective was to develop rapid classification methods of starter cultures at the strain level by using a combination of hydrophobic grid membrane filters and Fourier transform infrared (FTIR) spectroscopy. Forty-four pulsed-field gel electrophoresis-verified strains of starter and nonstarter cultures including Streptococcus thermophilus, Propionibacterium freudenreichii, and Lactobacillus spp. were analyzed. The strains were grown on their respective agar media, transferred to broth media, and incubated. Then, cultures were centrifuged and the pellets were resuspended in saline solution (10 μL). Aliquots (2 μL) of the suspended bacterial solution were placed onto a grid of the hydrophobic grid membrane filters, having 6 grids per each strain analyzed. The dried filters were read by FTIR microspectroscopy fitted with an attenuated total reflectance probe. Collected spectra were statistically analyzed by a soft independent modeling of class analogy (SIMCA) for pattern recognition. Classification models were developed for Streptococcus thermophilus, Propionibacterium freudenreichii, and Lactobacillus spp. strains. The models showed major discrimination in the spectral region from 1,200 to 900 cm(-1) associated with signals from phosphate-containing compounds and various polysaccharides in the cell wall. The developed method allowed for rapid classification of several Swiss cheese starter and nonstarter cultures at the strain level. This information provides a detailed overview of microbiological status, which would enable corrective measures to be taken early in the cheese making process, limiting production of inferior quality cheese and minimizing defects. This method could be an

Evaluation of bacterial communities belonging to natural whey starters for Grana Padano cheese by length heterogeneity-PCR.

PubMed

Lazzi, C; Rossetti, L; Zago, M; Neviani, E; Giraffa, G

2004-01-01

To detect bacteria present in controlled dairy ecosystems with defined composition by length-heterogeneity (LH)-PCR. LH-PCR allows to distinguish different organisms on the basis of natural variations in the length of 16S rRNA gene sequences. LH-PCR was applied to depict population structure of the lactic acid bacteria (LAB) species recoverable from Grana Padano cheese whey starters. Typical bacterial species present in the LAB community were evidenced and well discriminated. Small differences in species composition, e.g. the frequent finding of Streptococcus thermophilus and the constant presence of thermophilic lactobacilli (Lactobacillus helveticus, Lact. delbrueckii subsp. lactis/bulgaricus and Lact. fermentum) were reliably highlighted. Specificity of LH-PCR was confirmed by species-specific PCR from total DNA of the cultures. LH-PCR is a useful tool to monitor microbial composition and population dynamics in dairy starter cultures. When present, non-dominant bacterial species present in the whey starters, such as Strep. thermophilus, can easily be visualized and characterized without isolating and cultivating single strains. A similar approach can be applied to more complex dairy ecosystems such as milk or cheese curd. Community members and differences in population structure of controlled dairy ecosystems such as whey starters for hard cheeses can be evaluated and compared in a relative easy, fast, reliable and highly reproducible way.

Microbiological and fermentative properties of baker's yeast starter used in breadmaking.

PubMed

Reale, A; Di Renzo, T; Succi, M; Tremonte, P; Coppola, R; Sorrentino, E

2013-08-01

This study assessed the levels of microbial contaminants in liquid, compressed and dry commercial baker's yeasts used as starters in breadmaking. Eumycetes, Enterobacteriaceae, total and fecal coliforms, Bacillus spp., and lactic acid bacteria (LAB), in particular enterococci, were quantified. Results obtained in this study highlighted that baker's yeast could represent a potential vehicle of spoilage and undesirable microorganisms into the baking environment, even if these do not influence the leavening activity in the dough, as ascertained by rheofermentometer analysis. Different microbial groups, such as spore-forming bacteria and moulds, were found in baker's yeast starters. Moreover, different species of LAB, which are considered the main contaminants in large-scale yeast fermentations, were isolated and identified by Denaturing Gradient Gel Electrophoresis (DGGE) and 16S rDNA sequencing. The most recurrent species were Lactobacillus plantarum, Enterococcus faecalis, and Enterococcus durans, isolated from both compressed and dry starters, whereas strains belonging to Leuconostoc and Pediococcus genera were found only in dry ones. Nested-Polymerase Chain Reaction (Nested-PCR) and Randomly Amplified Polymorphic DNA-PCR (RAPD-PCR) were also used to highlight the biodiversity of the different commercial yeast strains, and to ascertain the culture purity. © 2013 Institute of Food Technologists®

Evaluation of the use of malic acid decarboxylase-deficient starter culture in NaCl-free cucumber fermentations to reduce bloater incidence.

PubMed

Zhai, Y; Pérez-Díaz, I M; Diaz, J T; Lombardi, R L; Connelly, L E

2018-01-01

Accumulation of carbon dioxide (CO 2 ) in cucumber fermentations is known to cause hollow cavities inside whole fruits or bloaters, conducive to economic losses for the pickling industry. This study focused on evaluating the use of a malic acid decarboxylase (MDC)-deficient starter culture to minimize CO 2 production and the resulting bloater index in sodium chloride-free cucumber fermentations brined with CaCl 2 . Attempts to isolate autochthonous MDC-deficient starter cultures from commercial fermentations, using the MD medium for screening, were unsuccessful. The utilization of allochthonous MDC-deficient starter cultures resulted in incomplete utilization of sugars and delayed fermentations. Acidified fermentations were considered, to suppress the indigenous microbiota and favour proliferation of the allochthonous MDC-deficient Lactobacillus plantarum starter cultures. Inoculation of acidified fermentations with L. plantarum alone or in combination with Lactobacillus brevis minimally improved the conversion of sugars. However, inoculation of the pure allochthonous MDC-deficient starter culture to 10 7 CFU per ml in acidified fermentations resulted in a reduced bloater index as compared to wild fermentations and those inoculated with the mixed starter culture. Although use of an allochthonous MDC-deficient starter culture reduces bloater index in acidified cucumber fermentations brined with CaCl 2 , an incomplete conversion of sugars is observed. Economical losses due to the incidence of bloaters in commercial cucumber fermentations brined with CaCl 2 may be reduced utilizing a starter culture to high cell density. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Tuning Chocolate Flavor through Development of Thermotolerant Saccharomyces cerevisiae Starter Cultures with Increased Acetate Ester Production

PubMed Central

Meersman, Esther; Steensels, Jan; Struyf, Nore; Paulus, Tinneke; Saels, Veerle; Mathawan, Melissa; Allegaert, Leen; Vrancken, Gino

2015-01-01

Microbial starter cultures have extensively been used to enhance the consistency and efficiency of industrial fermentations. Despite the advantages of such controlled fermentations, the fermentation involved in the production of chocolate is still a spontaneous process that relies on the natural microbiota at cocoa farms. However, recent studies indicate that certain thermotolerant Saccharomyces cerevisiae cultures can be used as starter cultures for cocoa pulp fermentation. In this study, we investigate the potential of specifically developed starter cultures to modulate chocolate aroma. Specifically, we developed several new S. cerevisiae hybrids that combine thermotolerance and efficient cocoa pulp fermentation with a high production of volatile flavor-active esters. In addition, we investigated the potential of two strains of two non-Saccharomyces species that produce very large amounts of fruity esters (Pichia kluyveri and Cyberlindnera fabianii) to modulate chocolate aroma. Gas chromatography-mass spectrometry (GC-MS) analysis of the cocoa liquor revealed an increased concentration of various flavor-active esters and a decrease in spoilage-related off-flavors in batches inoculated with S. cerevisiae starter cultures and, to a lesser extent, in batches inoculated with P. kluyveri and Cyb. fabianii. Additionally, GC-MS analysis of chocolate samples revealed that while most short-chain esters evaporated during conching, longer and more-fat-soluble ethyl and acetate esters, such as ethyl octanoate, phenylethyl acetate, ethyl phenylacetate, ethyl decanoate, and ethyl dodecanoate, remained almost unaffected. Sensory analysis by an expert panel confirmed significant differences in the aromas of chocolates produced with different starter cultures. Together, these results show that the selection of different yeast cultures opens novel avenues for modulating chocolate flavor. PMID:26590272

Tuning Chocolate Flavor through Development of Thermotolerant Saccharomyces cerevisiae Starter Cultures with Increased Acetate Ester Production.

PubMed

Meersman, Esther; Steensels, Jan; Struyf, Nore; Paulus, Tinneke; Saels, Veerle; Mathawan, Melissa; Allegaert, Leen; Vrancken, Gino; Verstrepen, Kevin J

2016-01-15

Microbial starter cultures have extensively been used to enhance the consistency and efficiency of industrial fermentations. Despite the advantages of such controlled fermentations, the fermentation involved in the production of chocolate is still a spontaneous process that relies on the natural microbiota at cocoa farms. However, recent studies indicate that certain thermotolerant Saccharomyces cerevisiae cultures can be used as starter cultures for cocoa pulp fermentation. In this study, we investigate the potential of specifically developed starter cultures to modulate chocolate aroma. Specifically, we developed several new S. cerevisiae hybrids that combine thermotolerance and efficient cocoa pulp fermentation with a high production of volatile flavor-active esters. In addition, we investigated the potential of two strains of two non-Saccharomyces species that produce very large amounts of fruity esters (Pichia kluyveri and Cyberlindnera fabianii) to modulate chocolate aroma. Gas chromatography-mass spectrometry (GC-MS) analysis of the cocoa liquor revealed an increased concentration of various flavor-active esters and a decrease in spoilage-related off-flavors in batches inoculated with S. cerevisiae starter cultures and, to a lesser extent, in batches inoculated with P. kluyveri and Cyb. fabianii. Additionally, GC-MS analysis of chocolate samples revealed that while most short-chain esters evaporated during conching, longer and more-fat-soluble ethyl and acetate esters, such as ethyl octanoate, phenylethyl acetate, ethyl phenylacetate, ethyl decanoate, and ethyl dodecanoate, remained almost unaffected. Sensory analysis by an expert panel confirmed significant differences in the aromas of chocolates produced with different starter cultures. Together, these results show that the selection of different yeast cultures opens novel avenues for modulating chocolate flavor. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Reduction of Biogenic Amines during Miso Fermentation by Lactobacillus plantarum as a Starter Culture.

PubMed

Lee, Yi-Chen; Kung, Hsien-Feng; Huang, Ya-Ling; Wu, Chien-Hui; Huang, Yu-Ru; Tsai, Yung-Hsiang

2016-09-01

Lactobacillus plantarum D-103 isolated from a miso product that possesses amine-degrading activity was used as a starter culture in miso fermentation (25°C for 120 days) in this study. The salt content in control samples (without starter culture) and inoculated samples (inoculated with L. plantarum D-103) remained constant at 10.4% of the original salt concentration throughout fermentation, whereas the pH value decreased from 6.2 to 4.6 during fermentation. The inoculated samples had significantly lower (P < 0.05) levels of total volatile basic nitrogen than control samples after 40 days of fermentation. After 120 days of fermentation, the histamine and overall biogenic amine contents in inoculated samples were reduced by 58 and 27%, respectively, compared with control samples. To our knowledge, this is the first report to demonstrate that application of a starter culture with amine-degrading activity in miso products was effective in reducing the accumulation of biogenic amines.

Kinetic analysis of strains of lactic acid bacteria and acetic acid bacteria in cocoa pulp simulation media toward development of a starter culture for cocoa bean fermentation.

PubMed

Lefeber, Timothy; Janssens, Maarten; Camu, Nicholas; De Vuyst, Luc

2010-12-01

The composition of cocoa pulp simulation media (PSM) was optimized with species-specific strains of lactic acid bacteria (PSM-LAB) and acetic acid bacteria (PSM-AAB). Also, laboratory fermentations were carried out in PSM to investigate growth and metabolite production of strains of Lactobacillus plantarum and Lactobacillus fermentum and of Acetobacter pasteurianus isolated from Ghanaian cocoa bean heap fermentations, in view of the development of a defined starter culture. In a first step, a selection of strains was made out of a pool of strains of these LAB and AAB species, obtained from previous studies, based on their fermentation kinetics in PSM. Also, various concentrations of citric acid in the presence of glucose and/or fructose (PSM-LAB) and of lactic acid in the presence of ethanol (PSM-AAB) were tested. These data could explain the competitiveness of particular cocoa-specific strains, namely, L. plantarum 80 (homolactic and acid tolerant), L. fermentum 222 (heterolactic, citric acid fermenting, mannitol producing, and less acid tolerant), and A. pasteurianus 386B (ethanol and lactic acid oxidizing, acetic acid overoxidizing, acid tolerant, and moderately heat tolerant), during the natural cocoa bean fermentation process. For instance, it turned out that the capacity to use citric acid, which was exhibited by L. fermentum 222, is of the utmost importance. Also, the formation of mannitol was dependent not only on the LAB strain but also on environmental conditions. A mixture of L. plantarum 80, L. fermentum 222, and A. pasteurianus 386B can now be considered a mixed-strain starter culture for better controlled and more reliable cocoa bean fermentation processes.

Evaluation of Mixed Probiotic Starter Cultures Isolated from Kimchi on Physicochemical and Functional Properties, and Volatile Compounds of Fermented Hams.

PubMed

Kim, Young Joo; Park, Sung Yong; Lee, Hong Chul; Yoo, Seung Seok; Oh, Sejong; Kim, Kwang Hyun; Chin, Koo Bok

2016-01-01

The objective of this study was to investigate the effects of mixed starter cultures isolated from kimchi on physicochemical properties, functionality and flavors of fermented ham. Physicochemical properties, microbial counts, shear force, cholesterol contents and volatile compounds of fermented ham were investigated during processing (curing and ripening time). Curing process for 7 d increased saltiness, however, decreased hunter color values (L, a, and b values). Ripening process for 21 d increased most parameters, such as saltiness, color values, weight loss, shear force and cholesterol content due to the drying process. The mixed starter culture had higher lactic acid bacteria than the commercial one. While eight volatile compounds were identified from fermented hams during curing process, total fiftyeight volatile compounds were identified from fermented hams during ripening process. The main volatile compounds were alcohols, esters and furans. However, no differences in volatile compounds were observed between two batches. Fermented hams (batch B) manufactured with probiotic starter culture (LPP) had higher sensory score in texture, color and overall acceptability than counterparts (batch A), while the opposite trend was observed in flavor. Therefore, mixed probiotic starter culture isolated from kimchi might be used as a starter culture to be able to replace with commercial starter culture (LK-30 plus) for the manufacture of fermented ham.

Evaluation of Mixed Probiotic Starter Cultures Isolated from Kimchi on Physicochemical and Functional Properties, and Volatile Compounds of Fermented Hams

PubMed Central

Yoo, Seung Seok

2016-01-01

The objective of this study was to investigate the effects of mixed starter cultures isolated from kimchi on physicochemical properties, functionality and flavors of fermented ham. Physicochemical properties, microbial counts, shear force, cholesterol contents and volatile compounds of fermented ham were investigated during processing (curing and ripening time). Curing process for 7 d increased saltiness, however, decreased hunter color values (L, a, and b values). Ripening process for 21 d increased most parameters, such as saltiness, color values, weight loss, shear force and cholesterol content due to the drying process. The mixed starter culture had higher lactic acid bacteria than the commercial one. While eight volatile compounds were identified from fermented hams during curing process, total fiftyeight volatile compounds were identified from fermented hams during ripening process. The main volatile compounds were alcohols, esters and furans. However, no differences in volatile compounds were observed between two batches. Fermented hams (batch B) manufactured with probiotic starter culture (LPP) had higher sensory score in texture, color and overall acceptability than counterparts (batch A), while the opposite trend was observed in flavor. Therefore, mixed probiotic starter culture isolated from kimchi might be used as a starter culture to be able to replace with commercial starter culture (LK-30 plus) for the manufacture of fermented ham. PMID:27499673

Exopolysaccharide-forming Weissella strains as starter cultures for sorghum and wheat sourdoughs.

PubMed

Galle, Sandra; Schwab, Clarissa; Arendt, Elke; Gänzle, Michael

2010-05-12

The addition of sourdough fermented with lactic acid bacteria synthesizing organic acids and oligo- and exopolysaccharides (EPS) from sucrose enhances texture, nutritional value, shelf life, and machinability of wheat, rye, and gluten-free bread. This study compared acetate, mannitol, and oligosaccharide formation of EPS-producing strains of Weissella and Leuconostoc spp. to the traditional sourdough starter Lactobacillus sanfranciscensis. In broth, Leuconostoc strains generally formed acetate and mannitol, whereas Weissella produced only small amounts of acetate and no mannitol in the presence of sucrose. In the presence of sucrose and maltose, Weissella and Leuconostoc strains synthesized glucooligosaccharides and EPS. Strains of Weissella were employed as starter cultures for wheat and sorghum sourdough and formed 0.8-8 g kg(-1) EPS and gluco-oligosaccharides but only low amounts of acetate and mannitol. In contrast, the formation of EPS from sucrose led to the production of high amounts of acetate and mannitol by L. sanfranciscensis LTH 2950 in wheat sourdough. This study indicates that Weissella strains are suitable starter cultures for wheat and sorghum sourdoughs and efficiently produce gluco-oligosaccharides and EPS.

Kinetic Analysis of Strains of Lactic Acid Bacteria and Acetic Acid Bacteria in Cocoa Pulp Simulation Media toward Development of a Starter Culture for Cocoa Bean Fermentation ▿

PubMed Central

Lefeber, Timothy; Janssens, Maarten; Camu, Nicholas; De Vuyst, Luc

2010-01-01

The composition of cocoa pulp simulation media (PSM) was optimized with species-specific strains of lactic acid bacteria (PSM-LAB) and acetic acid bacteria (PSM-AAB). Also, laboratory fermentations were carried out in PSM to investigate growth and metabolite production of strains of Lactobacillus plantarum and Lactobacillus fermentum and of Acetobacter pasteurianus isolated from Ghanaian cocoa bean heap fermentations, in view of the development of a defined starter culture. In a first step, a selection of strains was made out of a pool of strains of these LAB and AAB species, obtained from previous studies, based on their fermentation kinetics in PSM. Also, various concentrations of citric acid in the presence of glucose and/or fructose (PSM-LAB) and of lactic acid in the presence of ethanol (PSM-AAB) were tested. These data could explain the competitiveness of particular cocoa-specific strains, namely, L. plantarum 80 (homolactic and acid tolerant), L. fermentum 222 (heterolactic, citric acid fermenting, mannitol producing, and less acid tolerant), and A. pasteurianus 386B (ethanol and lactic acid oxidizing, acetic acid overoxidizing, acid tolerant, and moderately heat tolerant), during the natural cocoa bean fermentation process. For instance, it turned out that the capacity to use citric acid, which was exhibited by L. fermentum 222, is of the utmost importance. Also, the formation of mannitol was dependent not only on the LAB strain but also on environmental conditions. A mixture of L. plantarum 80, L. fermentum 222, and A. pasteurianus 386B can now be considered a mixed-strain starter culture for better controlled and more reliable cocoa bean fermentation processes. PMID:20889778

Microbial diversity of a Camembert-type cheese using freeze-dried Tibetan kefir coculture as starter culture by culture-dependent and culture-independent methods.

PubMed

Mei, Jun; Guo, Qizhen; Wu, Yan; Li, Yunfei

2014-01-01

The biochemical changes occurring during cheese ripening are directly and indirectly dependent on the microbial associations of starter cultures. Freeze-dried Tibetan kefir coculture was used as a starter culture in the Camembert-type cheese production for the first time. Therefore, it's necessary to elucidate the stability, organization and identification of the dominant microbiota presented in the cheese. Bacteria and yeasts were subjected to culture-dependent on selective media and culture-independent polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) analysis and sequencing of dominant bands to assess the microbial structure and dynamics through ripening. In further studies, kefir grains were observed using scanning electron microscopy (SEM) methods. A total of 147 bacteria and 129 yeasts were obtained from the cheese during ripening. Lactobacillus paracasei represents the most commonly identified lactic acid bacteria isolates, with 59 of a total of 147 isolates, followed by Lactococcus lactis (29 isolates). Meanwhile, Kazachstania servazzii (51 isolates) represented the mainly identified yeast isolate, followed by Saccharomyces cerevisiae (40 isolates). However, some lactic acid bacteria detected by sequence analysis of DGGE bands were not recovered by plating. The yeast S. cerevisiae and K. servazzii are described for the first time with kefir starter culture. SEM showed that the microbiota were dominated by a variety of lactobacilli (long and curved) cells growing in close association with a few yeasts in the inner portion of the grain and the short lactobacilli were observed along with yeast cells on the exterior portion. Results indicated that conventional culture method and PCR-DGGE should be combined to describe in maximal detail the microbiological composition in the cheese during ripening. The data could help in the selection of appropriate commercial starters for Camembert-type cheese.

Microbial Diversity of a Camembert-Type Cheese Using Freeze-Dried Tibetan Kefir Coculture as Starter Culture by Culture-Dependent and Culture-Independent Methods

PubMed Central

Mei, Jun; Guo, Qizhen; Wu, Yan; Li, Yunfei

2014-01-01

The biochemical changes occurring during cheese ripening are directly and indirectly dependent on the microbial associations of starter cultures. Freeze-dried Tibetan kefir coculture was used as a starter culture in the Camembert-type cheese production for the first time. Therefore, it's necessary to elucidate the stability, organization and identification of the dominant microbiota presented in the cheese. Bacteria and yeasts were subjected to culture-dependent on selective media and culture-independent polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) analysis and sequencing of dominant bands to assess the microbial structure and dynamics through ripening. In further studies, kefir grains were observed using scanning electron microscopy (SEM) methods. A total of 147 bacteria and 129 yeasts were obtained from the cheese during ripening. Lactobacillus paracasei represents the most commonly identified lactic acid bacteria isolates, with 59 of a total of 147 isolates, followed by Lactococcus lactis (29 isolates). Meanwhile, Kazachstania servazzii (51 isolates) represented the mainly identified yeast isolate, followed by Saccharomyces cerevisiae (40 isolates). However, some lactic acid bacteria detected by sequence analysis of DGGE bands were not recovered by plating. The yeast S. cerevisiae and K. servazzii are described for the first time with kefir starter culture. SEM showed that the microbiota were dominated by a variety of lactobacilli (long and curved) cells growing in close association with a few yeasts in the inner portion of the grain and the short lactobacilli were observed along with yeast cells on the exterior portion. Results indicated that conventional culture method and PCR-DGGE should be combined to describe in maximal detail the microbiological composition in the cheese during ripening. The data could help in the selection of appropriate commercial starters for Camembert-type cheese. PMID:25360757

Indigenous Starter Cultures to Improve Quality of Artisanal Dry Fermented Sausages from Chaco (Argentina).

PubMed

Palavecino Prpich, Noelia Z; Castro, Marcela P; Cayré, María E; Garro, Oscar A; Vignolo, Graciela M

2015-01-01

Lactic acid bacteria (LAB) and coagulase negative cocci (CNC) were isolated from artisanal dry sausages sampled from the northeastern region of Chaco, Argentina. In order to evaluate their performance in situ and considering technological features of the isolated strains, two mixed selected autochthonous starter cultures (SAS) were designed: (i) SAS-1 (Lactobacillus sakei 487 + Staphylococcus vitulinus C2) and (ii) SAS-2 (L. sakei 442 + S. xylosus C8). Cultures were introduced into dry sausage manufacturing process at a local small-scale facility. Microbiological and physicochemical parameters were monitored throughout fermentation and ripening periods, while sensory attributes of the final products were evaluated by a trained panel. Lactic acid bacteria revealed their ability to colonize and adapt properly to the meat matrix, inhibiting the growth of spontaneous microflora and enhancing safety and hygienic profile of the products. Both SAS showed a beneficial effect on lipid oxidation and texture of the final products. Staphylococcus vitulinus C2, from SAS-1, promoted a better redness of the final product. Sensory profile revealed that SAS addition preserved typical sensory attributes. Introduction of these cultures could provide an additional tool to standardize manufacturing processes aiming to enhance safety and quality while keeping typical sensory attributes of regional dry fermented sausages.

Lactobacillus plantarum (KACC 92189) as a Potential Probiotic Starter Culture for Quality Improvement of Fermented Sausages

PubMed Central

2018-01-01

This study was conducted to evaluate the effects of fermenting temperature on the applicability of Lactobacillus plantarum for production of fermented sausages as starter cultures, and its applicable efficiency was also compared with those inoculated with commercial starter culture or non-inoculated control. The L. plantarum isolated from a naturally-fermented meat, identified by 16S rDNA sequencing and again identified by de novo Assembly Analysis method was used as a starter culture. Six treatments: 3 with L. plantarum at different fermenting temperatures (20, 25 and 30°C), and other 3 treatments (1 with commercial starter culture, 1 with its mixture with L. plantarum and 1 non-inoculated control) fermented under the same conditions (25°C) were prepared. Results revealed that the fermenting temperature considerably affected the pH change in samples added with L. plantarum; the highest pH drop rate (1.57 unit) was obtained on the samples fermented at 30°C, followed by those at 25°C (1.3 unit) and 20°C (0.99 unit) after 4 days fermentation. Increasing the temperature up to 30°C resulted in significantly lower spoilage bacteria count (5.15 log CFU/g) and lipid oxidation level in the products inoculated with L. plantarum. The sensory analysis also showed that the samples added with L. plantarum at 30°C had significantly higher odor, taste and acceptability scores than those fermented at lower temperatures. Under the same processing condition, although the L. plantarum showed slightly lower acidification than the commercial starter culture, however, it significantly improved the eating quality of the product. PMID:29725237

Viability of Staphylococcus xylosus isolated from artisanal sausages for application as starter cultures in meat products.

PubMed

Fiorentini, Angela Maria; Sawitzki, Maristela Cortez; Bertol, Teresinha Marisa; Sant'anna, Ernani S

2009-01-01

Viability of Staphylococcus xylosus isolated from artisanal sausages for application as starter cultures in meat products Viability of Staphylococcus xylosus strains AD1 and U5 isolated from natural fermented sausages was investigated as starter cultures in fermented sausages produced in the South Region of Brazil. The study demonstrated that the Staphylococcus xylosus strains AD1 and U5 showed significant growth during fermentation, stability over freeze-dried process, negative reaction for staphylococcal enterotoxins and viability for using as a single-strain culture or associated with lactic acid bacteria for production of fermented sausages.

Viability of Staphylococcus xylosus isolated from artisanal sausages for application as starter cultures in meat products

PubMed Central

Fiorentini, Ângela Maria; Sawitzki, Maristela Cortez; Bertol, Teresinha Marisa; Sant’Anna, Ernani S.

2009-01-01

Viability of Staphylococcus xylosus isolated from artisanal sausages for application as starter cultures in meat products Viability of Staphylococcus xylosus strains AD1 and U5 isolated from natural fermented sausages was investigated as starter cultures in fermented sausages produced in the South Region of Brazil. The study demonstrated that the Staphylococcus xylosus strains AD1 and U5 showed significant growth during fermentation, stability over freeze-dried process, negative reaction for staphylococcal enterotoxins and viability for using as a single-strain culture or associated with lactic acid bacteria for production of fermented sausages. PMID:24031331

Enhancement of γ-aminobutyric acid (GABA) in Nham (Thai fermented pork sausage) using starter cultures of Lactobacillus namurensis NH2 and Pediococcus pentosaceus HN8.

PubMed

Ratanaburee, Anussara; Kantachote, Duangporn; Charernjiratrakul, Wilawan; Sukhoom, Ampaitip

2013-10-15

The aim was to produce Nham that was enriched with γ-aminobutyric acid (GABA); therefore two GABA producing lactic acid bacteria (Pediococcus pentosaceus HN8 and Lactobacillus namurensis NH2) were used as starter cultures. By using the central composite design (CCD) we showed that addition of 0.5% monosodium glutamate (MSG) together with an inoculum size of roughly 6logCFU/g of each of the two strains produced a maximal amounts of GABA (4051 mg/kg) in the 'GABA Nham' product. This was higher than any current popular commercial Nham product by roughly 8 times. 'GABA Nham' with the additions of both starters and MSG (TSM) supported maximum populations of lactic acid bacteria (LAB) with a minimum of yeasts and no staphylococci or molds when compared to the controls that had no addition of any starters or MSG (TNN), or only the addition of MSG (TNM), or with only the starter (TSN). Based on proximate analysis among the Nham sets, 'GABA Nham' was low in fat, carbohydrate and energy although its texture and color were slightly different from the control (TNN). However, sensory evaluations of 'GABA Nham' were more acceptable than the controls and commercial Nham products for all tested parameters. Hence, a unique novel 'GABA Nham' fermented pork sausage was successfully developed. © 2013.

Effect of starter cultures on survival of Listeria monocytogenes in Čajna sausage

NASA Astrophysics Data System (ADS)

Bošković, M.; Tadić, V.; Đorđević, J.; Glišić, M.; Lakićević, B.; Dimitrijević, M.; Baltić, M. Ž.

2017-09-01

The aim of the study was to evaluate the survival of Listeria monocytogenes during the production of Čajna sausage with short maturation time. Sausage batter was inoculated with three different serotypes 4b and serotype 1/2a of L. monocytogenes. Control sausages were without any starter culture added; the second batch was inoculated with strains of Lactobacillus sakei, Staphylococcus carnosus and Staphylococcus xylosus, and the third batch was inoculated with strains of Debaryomyces hansenii, Lactobacillus sakei, Pediococcus acidilactici, Pediococcus pentosaceus, Staphylococcus carnosus and Staphylococcus xylosus. After 18 days of ripening, L. monocytogenes was not detected in any of the sausages, but during this fermentation and drying, the numbers of this pathogen was lower in the sausages inoculated with starter cultures.

Effect of six different starter cultures on the concentration of residual nitrite in fermented sausages during in vitro human digestion.

PubMed

Kim, Hyeong Sang; Hur, Sun Jin

2018-01-15

The objective of this study was to determine the effect of six different starter cultures of enterobacteria on the concentration of residual nitrite in fermented sausages during in vitro human digestion. Before digestion, the concentration of residual nitrite was dependent on starter culture in fermented sausage and ranged from 25.2 to 33.2mg/kg. Among the six starter cultures of enterobacteria, Pediococcus acidilactici, Pediococcus pentosaceus, and Staphylococcus carnosus showed higher nitrite depletion ability than the other three strains in fermented sausages. The concentration of residual nitrite in fermented sausages was significantly (p<0.05) decreased after stomach digestion and ranged from 17.4 to 21.6mg/kg. Enterobacteria Escherichia coli (E. coli) and/or Lactobacillus casei (L. casei) effectively increased the degree of depletion of residual nitrite in large intestine digestion. In conclusion, starter cultures could influence the concentration of residual nitrite during in vitro human digestion. They could deplete residual nitrite in fermented sausages. Copyright © 2017 Elsevier Ltd. All rights reserved.

Halobacterium sp. SP1(1) as a starter culture for accelerating fish sauce fermentation.

PubMed

Akolkar, A V; Durai, D; Desai, A J

2010-07-01

Application of Halobacterium sp. SP1(1) for the acceleration of fish sauce fermentation. Traditional fish sauce fermentation was mimicked using Halobacterium sp. SP1(1) as starter culture. Protease activity, peptide release and α-amino content (parameters used to monitor the progress of the fermentation) were high at day 10 in tests and day 20 in un-inoculated controls. The total protein and nitrogen contents were also high in tests compared with controls. The amino acid profile observed at the end of fermentation in experimental samples, when compared with the commercial sauce preparation, was found to be better with respect to flavour and aroma contributing amino acids as well as essential amino acid lysine. Microflora analysis of the final fish sauce revealed the absence of any nonhalophilic or halotolerant micro-organisms. The protease-producing halophilic isolates obtained from the fish sauce of eviscerated and uneviscerated controls were identified as Halobacterium sp. F1 and F2, respectively, by 16S rDNA sequence analysis. Exogenous augmentation of Halobacterium sp. SP1(1) accelerated the fish sauce fermentation process with an additive effect on the existing natural microflora present in the fish during fermentation. Halobacterium sp SP1(1), therefore, can be used as an important starter culture for accelerating the fish fermentation process, which is attributed to its extracellular protease. The present study is the first report on use of Halobacterium species as a starter culture for accelerating fish sauce fermentation. Use of halobacterial starter cultures may revolutionize the process in fish sauce industries by reducing the fermentation time and making the process more economical with improved nutritive value of product. Journal compilation © 2009 The Society for Applied Microbiology. No claim to Indian Government works.

Selection of functional lactic acid bacteria as starter cultures for the fermentation of Korean leek (Allium tuberosum Rottler ex Sprengel.).

PubMed

Yang, Jaesik; Ji, Yosep; Park, Hyunjoon; Lee, Jieun; Park, Soyoung; Yeo, Soyoung; Shin, Hyunkil; Holzapfel, Wilhelm H

2014-11-17

The purpose of this research was to find safe and suitable starter cultures for the fermentation of Korean leek (Allium tuberosum Rottler), also known as garlic chives or Oriental garlic. This traditional herb has several functional properties and a strong flavour; its leaves are used as food material. Eighteen strains of lactic acid bacteria (LAB) were isolated from well-fermented leek kimchi. Controlled fermentation of the leek leaves was conducted with 2 strains (Weissella confusa LK4 and Lactobacillus plantarum LK8), selected as potential starter cultures on the basis of their safety properties, and on the pH, total titratable acidity (TTA), and viable cell numbers [colony forming units (CFUml(-1))] achieved during the fermentation. Microbial dynamics was also followed during fermentation by using PCR-DGGE (Denaturing Gradient Gel Electrophoresis) on DNA level. To analyse bioactive compounds such as thiols and allicin (diallyl thiosulfinates), the total flavonoid and polyphenolic contents were determined by colorimetric methods. Functional properties were assessed on the basis of anti-oxidative capacities by determining the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging effect, and ferric reducing antioxidant power (FRAP). W. confusa LK4 rapidly increased during the first stage of leek fermentation, and was mainly responsible for accelerated fermentation during the early period in contrast to L. plantarum LK8, a stronger acid producer during the later stages of fermentation. After 48 h fermentation, leeks fermented with W. confusa LK4 showed the highest radical scavenging effects and reducing ability. The detectable amount of allicin of fermented leeks decreased relative to the change in pH, whereas the concentration of thiols significantly increased. Total flavonoid and poly-phenolic contents changed during fermentation and showed correlation with anti-oxidant effects. We therefore suggest the suitability of W. confusa LK4 as a potential starter

Modeling of rheological characteristics of the fermented dairy products obtained by novel and traditional starter cultures.

PubMed

Vukić, Dajana V; Vukić, Vladimir R; Milanović, Spasenija D; Ilicić, Mirela D; Kanurić, Katarina G

2018-06-01

Tree different fermented dairy products obtained by conventional and non-conventional starter cultures were investigated in this paper. Textural and rheological characteristics as well as chemical composition during 21 days of storage were analysed and subsequent data processing was performed by principal component analysis. The analysis of samples` flow behaviour was focused on their time dependent properties. Parameters of Power law model described flow behaviour of samples depended on used starter culture and days of storage. The Power law model was applied successfully to describe the flow of the fermented milk, which had characteristics of shear thinning and non-Newtonian fluid behaviour.

Antifungal starter culture for packed bread: influence of two storage conditions.

PubMed

Gerez, Carla L; Fornaguera, María J; Obregozo, Mariano D; Font de Valdez, Graciela; Torino, María I

2015-01-01

In this study, we analyzed the conservation of a semi-liquid bio-preserver (SL778) developed with Lactobacillus plantarum CRL 778, a lactic acid bacterium (LAB) having antifungal activity. The characteristics of the SL778 starter remained stable during a 14-day storage at 4°C. At -20°C, cell viability and organic acid concentration showed a significant (p<0.05) decrease after 7 days. These differences observed between the storage temperatures tested were reflected in the acidification activity of SL778 during dough fermentation. However, SL778 maintained its antifungal efficacy up to a 14-day storage at both temperatures. Sensory attributes (acidic and spicy tastes and acidic smell) of breads manufactured with starter SL778 (stored at 4 or -20°C) were evaluated. No undesirable difference was detected with respect to bread control without SL778 and bread manufactured with SL778 (stored at 4 or -20°C). In conclusion, the SL778 semi-liquid bio-preserver can be stored at 4 or -20°C without modifying its antifungal activity during 14 days. Copyright © 2014 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Amino acid profile and sensory characteristics of dry fermented pork loins produced with a mixture of probiotic starter cultures.

PubMed

Neffe-Skocińska, Katarzyna; Okoń, Anna; Kołożyn-Krajewska, Danuta; Dolatowski, Zbigniew

2017-07-01

Proteolysis is a biochemical process in dry-aged meat products where proteins are metabolized and broken down to polypeptides, peptides, and free amino acids. In the literature it is reported that an appropriate choice of probiotic starter culture limits proteolytic changes in dry-fermented meat products. In this study the combined effect of a mixture of probiotic starter cultures on the free amino acid profile, total count of lactic acid bacteria, and the sensory quality of dry-aged pork loins after fermentation and after storing the vacuum-packed samples was evaluated. LOCK900 and BB12 probiotic strains were the technologically best two-species mixture of starter cultures for the production of probiotic dry-aged pork loins. They allowed us to obtain products with high and stable bacterial count and acceptable sensory quality, both after 21 days of fermentation and after 2 months of cold storage. Changes in the free amino acid profile and increased intensity of the selected sensory attributes result from a significant share of probiotics in meat proteolysis occurring during fermentation and storage. The results suggest the relevance of using probiotic bacteria as a two-species starter culture for the production of dry-aged products. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Two efficient nitrite-reducing Lactobacillus strains isolated from traditional fermented pork (Nanx Wudl) as competitive starter cultures for Chinese fermented dry sausage.

PubMed

Chen, Xi; Li, Jiapeng; Zhou, Tong; Li, Jinchun; Yang, Junna; Chen, Wenhua; Xiong, Youling L

2016-11-01

Lactic acid bacteria isolated from traditional Dong pork product (Nanx Wudl) were investigated for their potential as starter cultures for Chinese fermented dry sausages. Based on preliminary screening, Lactobacillus plantarum CMRC6 and Lactobacillus sakei CMRC15, both showing excellent nitrite-reducing capacity, were used as single-strain starter cultures. For comparison, a commercial composite starter was also tested. In CMRC6 and CMRC15-inoculated sausages, lactic acid bacteria dominated the microflora and improved the microbiological safety by suppression of Enterobacteriaceae growth. Nitrite content of all inoculated sausages declined rapidly during ripening compared to non-inoculated. Texture profiles analysis showed inoculated sausages had more pronounced textural development during ripening. Sensory evaluation indicated CMRC6 and CMRC15-fermented sausages had comparable or more desirable organoleptic characteristics than sausage made with commercial starters. Therefore, CMRC6 and CMRC15 are promising candidates as multi-functional starter cultures for microbiological safety and residual nitrite control in gourmet Chinese dry sausage production. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of an autochthonous starter culture on the production of a traditional dry fermented sausage from Chaco (Argentina) at a small-scale facility.

PubMed

Palavecino Prpich, Noelia Z; Garro, Oscar A; Romero, Mara; Judis, María A; Cayré, María E; Castro, Marcela P

2016-05-01

The performance of a mixed starter culture, SAS-1, comprised of the autochthonous strains Lactobacillus sakei ACU-2 and Staphylococcus vitulinus ACU-10, was evaluated into the production process of a traditional dry sausage. Microbiological, physicochemical and sensory analyses were carried out to accomplish this goal. Results showed an improvement in performance through the introduction of SAS-1; adding mixed starter culture rapidly decreased pH, inhibited the growth of contaminant microorganisms and enhanced the beneficial ones, diminished TBARS, and highlighted color and aroma attributes. However, most influential organoleptic descriptors among consumer acceptance were not affected by the addition of the starter. This starter culture would represent a valuable tool to improve the homogeneity of artisanal manufacture of this traditional food. Copyright © 2016 Elsevier Ltd. All rights reserved.

Growth and activity of Bulgarian yogurt starter culture in iron-fortified milk.

PubMed

Simova, Emilina; Ivanov, Galin; Simov, Zhelyazko

2008-10-01

Bulgarian yogurts were manufactured and fortified with 8, 15 and 27 mg of iron kg(-1) of yogurt. The growth and acidifying activity of the starter culture bacteria Streptococcus thermophilus 13a and Lactobacillus delbrueckii subsp. bulgaricus 2-11 were monitored during milk fermentation and over 15 days of yogurt storage at 4 degrees C. Fortifying milk with iron did not affect significantly the growth of the starter culture during manufacture and storage of yogurt. Counts of yogurt bacteria at the end of fermentation of iron-fortified milks were between 2.1 x 10(10) and 4.6 x 10(10) CFU ml(-1), which were not significantly different from numbers in unfortified yogurts. In all batches of yogurt, the viable cell counts of S. thermophilus 13a were approximately three times higher than those of L. delbrueckii subsp. bulgaricus 2-11. Greater decrease in viable cell count over 15 days of storage was observed for S. thermophilus 13a compared to L. delbrueckii subsp. bulgaricus 2-11. Intensive accumulation of lactic acid was observed during incubation of milk and all batches reached pH 4.5 +/- 0.1 after 3.0 h. At the end of fermentation process, lactic acid concentrations in iron-fortified yogurts were between 6.9 +/- 0.4 and 7.3 +/- 0.5 g l(-1). The acidifying activity of starter culture bacteria in the control and iron-fortified milks was similar. There was no increase in oxidized, metallic and bitter off-flavors in iron-fortified yogurts compared to the control. Iron-fortified yogurts did not differ significantly in their sensorial, chemical and microbiological characteristics with unfortified yogurt, suggesting that yogurt is a suitable vehicle for iron fortification and that the ferrous lactate is an appropriate iron source for yogurt fortification.

Adaptability of lactic acid bacteria and yeasts to sourdoughs prepared from cereals, pseudocereals and cassava and use of competitive strains as starters.

PubMed

Vogelmann, Stephanie A; Seitter, Michael; Singer, Ulrike; Brandt, Markus J; Hertel, Christian

2009-04-15

The adaptability of lactic acid bacteria (LAB) and yeasts to sourdoughs prepared from cereals, pseudocereals and cassava was investigated using PCR-DGGE and bacteriological culture combined with rRNA gene sequence analysis. Sourdoughs were prepared either from flours of the cereals wheat, rye, oat, barley, rice, maize, and millet, or from the pseudocereals amaranth, quinoa, and buckwheat, or from cassava, using a starter consisting of various species of LAB and yeasts. Doughs were propagated until a stable microbiota was established. The dominant LAB and yeast species were Lactobacillus fermentum, Lactobacillus helveticus, Lactobacillus paralimentarius, Lactobacillus plantarum, Lactobacillus pontis, Lactobacillus spicheri, Issatchenkia orientalis and Saccharomyces cerevisiae. The proportion of the species within the microbiota varied. L. paralimentarius dominated in the pseudocereal sourdoughs, L. fermentum, L. plantarum and L. spicheri in the cassava sourdough, and L. fermentum, L. helveticus and L. pontis in the cereal sourdoughs. S. cerevisiae constituted the dominating yeast, except for quinoa sourdough, where I. orientalis also reached similar counts, and buckwheat and oat sourdoughs, where no yeasts could be detected. To assess the usefulness of competitive LAB and yeasts as starters, the fermentations were repeated using flours from rice, maize, millet and the pseudocereals, and by starting the dough fermentation with selected dominant strains. At the end of fermentation, most of starter strains belonged to the dominating microbiota. For the rice, millet and quinoa sourdoughs the species composition was similar to that of the prior fermentation, whereas in the other sourdoughs, the composition differed.

Aminogenesis control in fermented sausages manufactured with pressurized meat batter and starter culture.

PubMed

Latorre-Moratalla, M L; Bover-Cid, S; Aymerich, T; Marcos, B; Vidal-Carou, M C; Garriga, M

2007-03-01

The application of high hydrostatic pressure (200MPa) to meat batter just before sausage fermentation and the inoculation of starter culture were studied to improve the safety and quality of traditional Spanish fermented sausages (fuet and chorizo). Higher amounts of biogenic amines were formed in chorizo than in fuet. Without interfering with the ripening performance in terms of acidification, drying and proteolysis, hydrostatic pressure prevented enterobacteria growth but did not affect Gram-positive bacteria significantly. Subsequently, a strong inhibition of diamine (putrescine and cadaverine) accumulation was observed, but that of tyramine was not affected. The inoculated decarboxylase-negative strains, selected from indigenous bacteria of traditional sausages, were resistant to the HHP treatment, being able to lead the fermentation process, prevent enterococci development and significantly reduce enterobacteria counts. In sausages manufactured with either non-pressurized or pressurized meat batter, starter culture was the most protective measure against the accumulation of tyramine and both diamines.

Characterization of aromatic properties of old-style cheese starters.

PubMed

Lacroix, N; St-Gelais, D; Champagne, C P; Fortin, J; Vuillemard, J-C

2010-08-01

Old-style cheese starters were evaluated to determine their ability to produce cheese aroma compounds. Detailed analyses of the aroma-producing potential of 13 old-style starter cultures were undertaken. The proteolytic profile of the starters was established by an accelerated ripening study using a model cheese slurry and compared with those of a commercial aromatic starter and commercial Cheddar cheeses. To evaluate the aromatic potential of the starter cultures, quantification of free amino acids liberated and volatile compounds after 15 d of ripening at 30 degrees C as well as sensory analysis were carried out. Results showed that proteolysis patterns of all 13 starter cultures in the curd model were comparable to those of commercial Cheddar cheeses. All tested cultures demonstrated the ability to produce high amounts of amino acids recognized as precursors of aroma compounds. Several differences were observed between the starters and commercial Cheddar cheeses regarding some amino acids such as glutamate, leucine, phenylalanine, proline, and ornithine, reflecting the various enzymatic systems present in the starters. Starters Bt (control) and ULAAC-E exhibited various significant differences regarding their free amino acid profiles, as confirmed by sensory analysis. In addition, identification of volatile compounds confirmed the presence of several key molecules related to aroma, such as 3-methylbutanal and diacetyl. Besides the aroma-producing aspect, 2 starters (ULAAC-A and ULAAC-H) seem to possess an important ability to generate large amounts of gamma-aminobutyric acid, which contributed up to 15% of the total amino acids present in the model curd after 15 d ripening. gamma-Aminobutyric acid is an amine well-known for its antihypertensive and calming effects. Copyright (c) 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Microbial diversity of traditional Vietnamese alcohol fermentation starters (banh men) as determined by PCR-mediated DGGE.

PubMed

Thanh, Vu Nguyen; Mai, Le Thuy; Tuan, Duong Anh

2008-12-10

The diversity of fungi and bacteria associated with traditional Vietnamese alcohol fermentation starters (banh men) was investigated by PCR-mediated DGGE. From 52 starter samples, 13 species of fungi (including yeasts) and 23 species of bacteria were identified. The fungal composition of the starters was consistent with little variation among samples. It consisted of amylase producers (Rhizopus oryzae, R. microsporus, Absidia corymbifera, Amylomyces sp., Saccharomycopsis fibuligera), ethanol producers (Saccharomyces cerevisiae, Issatchenkia sp., Pichia anomala, Candida tropicalis, P. ranongensis, Clavispora lusitaniae), and (opportunistic) contaminants (Xeromyces bisporus, Botryobasidium subcoronatum). The bacterial microflora of starters was highly variable in species composition and dominated by lactic acid bacteria (LAB). The most frequent LAB were Pediococcus pentosaceus, Lactobacillus plantarum, L. brevis, Weissella confusa, and W. paramesenteroides. Species of amylase-producing Bacillus (Bacillus subtilis, B. circulans, B. amyloliquefaciens, B. sporothermodurans), acetic acid bacteria (Acetobacter orientalis, A. pasteurianus), and plant pathogens/environment contaminants (Burkholderia ubonensis, Ralstonia solanacearum, Pelomonas puraquae) were also detected. Fungal DGGE was found to be useful for evaluating starter type and starter quality. Moreover, in view of the high biological diversity of these substrates, bacterial DGGE may be useful in determining the identity of a starter. The constant occurrence of opportunistic contaminants highlights the need for careful examination of the role of individual components in starters.

Genome Sequence of Lactococcus raffinolactis Strain 4877, Isolated from Natural Dairy Starter Culture

PubMed Central

Meslier, Victoria; Loux, Valentin

2012-01-01

The nonstarter lactic acid bacterium Lactococcus raffinolactis is prevalent in a wide range of environments, such as the dairy environment, but little is known about this species. Here, we present the draft genome of Lactococcus raffinolactis strain 4877, isolated from a natural mesophilic dairy starter culture. PMID:23105090

Benzoic Acid Production with Respect to Starter Culture and Incubation Temperature during Yogurt Fermentation using Response Surface Methodology.

PubMed

Yu, Hyung-Seok; Lee, Na-Kyoung; Jeon, Hye-Lin; Eom, Su Jin; Yoo, Mi-Young; Lim, Sang-Dong; Paik, Hyun-Dong

2016-01-01

Benzoic acid is occasionally used as a raw material supplement in food products and is sometimes generated during the fermentation process. In this study, the production of naturally occurring yogurt preservatives was investigated for various starter cultures and incubation temperatures, and considered food regulations. Streptococcus thermophilus, Lactobacillus acidophilus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus rhamnosus, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus reuteri, Lactobacillus plantarum, Bifidobacterium longum, Bifidobacterium lactis, Bifidobacterium bifidum, Bifidobacterium infantis, and Bifidobacterium breve were used as yogurt starter cultures in commercial starters. Among these strains, L. rhamnosus and L. paracasei showed the highest production of benzoic acid. Therefore, the use of L. rhamnosus, L. paracasei, S. thermophilus, and different incubation temperatures were examined to optimize benzoic acid production. Response surface methodology (RSM) based on a central composite design was performed for various incubation temperatures (35-44℃) and starter culture inoculum ratios (0-0.04%) in a commercial range of dairy fermentation processes. The optimum conditions were 0.04% L. rhamnosus, 0.01% L. paracasei, 0.02% S. thermophilus, and 38.12℃, and the predicted and estimated concentrations of benzoic acid were 13.31 and 13.94 mg/kg, respectively. These conditions maximized naturally occurring benzoic acid production during the yogurt fermentation process, and the observed production levels satisfied regulatory guidelines for benzoic acid in dairy products.

Benzoic Acid Production with Respect to Starter Culture and Incubation Temperature during Yogurt Fermentation using Response Surface Methodology

PubMed Central

Yoo, Mi-Young; Lim, Sang-Dong

2016-01-01

Benzoic acid is occasionally used as a raw material supplement in food products and is sometimes generated during the fermentation process. In this study, the production of naturally occurring yogurt preservatives was investigated for various starter cultures and incubation temperatures, and considered food regulations. Streptococcus thermophilus, Lactobacillus acidophilus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus rhamnosus, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus reuteri, Lactobacillus plantarum, Bifidobacterium longum, Bifidobacterium lactis, Bifidobacterium bifidum, Bifidobacterium infantis, and Bifidobacterium breve were used as yogurt starter cultures in commercial starters. Among these strains, L. rhamnosus and L. paracasei showed the highest production of benzoic acid. Therefore, the use of L. rhamnosus, L. paracasei, S. thermophilus, and different incubation temperatures were examined to optimize benzoic acid production. Response surface methodology (RSM) based on a central composite design was performed for various incubation temperatures (35-44℃) and starter culture inoculum ratios (0-0.04%) in a commercial range of dairy fermentation processes. The optimum conditions were 0.04% L. rhamnosus, 0.01% L. paracasei, 0.02% S. thermophilus, and 38.12℃, and the predicted and estimated concentrations of benzoic acid were 13.31 and 13.94 mg/kg, respectively. These conditions maximized naturally occurring benzoic acid production during the yogurt fermentation process, and the observed production levels satisfied regulatory guidelines for benzoic acid in dairy products. PMID:27433115

Particle formation induced by sonication during yogurt fermentation - Impact of exopolysaccharide-producing starter cultures on physical properties.

PubMed

Körzendörfer, Adrian; Nöbel, Stefan; Hinrichs, Jörg

2017-07-01

Two major quality defects of yogurt are syneresis and the presence of large particles, and several reasons have been extensively discussed. Vibrations during fermentation, particularly generated by pumps, must be considered as a further cause as latest research showed that both ultrasound and low frequencies induced visible particles. The aim of this study was to investigate the impact of sonication during fermentation with starter cultures differing in exopolysaccharide (EPS) synthesis on the physical properties of set (syneresis, firmness) and stirred yogurt (large particles, laser diffraction, rheology). Skim milk was fermented with starter cultures YC-471 (low EPS) or YF-L 901 (high EPS) (Chr. Hansen) and sonicated for 5min at pH5.2. Sonicated set gels exhibited syneresis and were softer than respective controls. The mechanical treatment was adjusted to quantify visible particles (d≥0.9mm) in stirred yogurts properly. Sonication significantly increased particle numbers, however, the effect was less pronounced when YF-L 901 was used, indicating EPS as a tool to reduce syneresis and particle formation due to vibrations. Rheological parameters and size of microgel particles were rather influenced by starter cultures than by sonication. Copyright © 2017 Elsevier Ltd. All rights reserved.

Microbiological and physicochemical characterization of small-scale cocoa fermentations and screening of yeast and bacterial strains to develop a defined starter culture.

PubMed

Pereira, Gilberto Vinícius de Melo; Miguel, Maria Gabriela da Cruz Pedrozo; Ramos, Cíntia Lacerda; Schwan, Rosane Freitas

2012-08-01

Spontaneous cocoa bean fermentations performed under bench- and pilot-scale conditions were studied using an integrated microbiological approach with culture-dependent and culture-independent techniques, as well as analyses of target metabolites from both cocoa pulp and cotyledons. Both fermentation ecosystems reached equilibrium through a two-phase process, starting with the simultaneous growth of the yeasts (with Saccharomyces cerevisiae as the dominant species) and lactic acid bacteria (LAB) (Lactobacillus fermentum and Lactobacillus plantarum were the dominant species), which were gradually replaced by the acetic acid bacteria (AAB) (Acetobacter tropicalis was the dominant species). In both processes, a sequence of substrate consumption (sucrose, glucose, fructose, and citric acid) and metabolite production kinetics (ethanol, lactic acid, and acetic acid) similar to that of previous, larger-scale fermentation experiments was observed. The technological potential of yeast, LAB, and AAB isolates was evaluated using a polyphasic study that included the measurement of stress-tolerant growth and fermentation kinetic parameters in cocoa pulp media. Overall, strains L. fermentum UFLA CHBE8.12 (citric acid fermenting, lactic acid producing, and tolerant to heat, acid, lactic acid, and ethanol), S. cerevisiae UFLA CHYC7.04 (ethanol producing and tolerant to acid, heat, and ethanol), and Acetobacter tropicalis UFLA CHBE16.01 (ethanol and lactic acid oxidizing, acetic acid producing, and tolerant to acid, heat, acetic acid, and ethanol) were selected to form a cocktail starter culture that should lead to better-controlled and more-reliable cocoa bean fermentation processes.

Microbiological and Physicochemical Characterization of Small-Scale Cocoa Fermentations and Screening of Yeast and Bacterial Strains To Develop a Defined Starter Culture

PubMed Central

Pereira, Gilberto Vinícius de Melo; Miguel, Maria Gabriela da Cruz Pedrozo; Ramos, Cíntia Lacerda

2012-01-01

Spontaneous cocoa bean fermentations performed under bench- and pilot-scale conditions were studied using an integrated microbiological approach with culture-dependent and culture-independent techniques, as well as analyses of target metabolites from both cocoa pulp and cotyledons. Both fermentation ecosystems reached equilibrium through a two-phase process, starting with the simultaneous growth of the yeasts (with Saccharomyces cerevisiae as the dominant species) and lactic acid bacteria (LAB) (Lactobacillus fermentum and Lactobacillus plantarum were the dominant species), which were gradually replaced by the acetic acid bacteria (AAB) (Acetobacter tropicalis was the dominant species). In both processes, a sequence of substrate consumption (sucrose, glucose, fructose, and citric acid) and metabolite production kinetics (ethanol, lactic acid, and acetic acid) similar to that of previous, larger-scale fermentation experiments was observed. The technological potential of yeast, LAB, and AAB isolates was evaluated using a polyphasic study that included the measurement of stress-tolerant growth and fermentation kinetic parameters in cocoa pulp media. Overall, strains L. fermentum UFLA CHBE8.12 (citric acid fermenting, lactic acid producing, and tolerant to heat, acid, lactic acid, and ethanol), S. cerevisiae UFLA CHYC7.04 (ethanol producing and tolerant to acid, heat, and ethanol), and Acetobacter tropicalis UFLA CHBE16.01 (ethanol and lactic acid oxidizing, acetic acid producing, and tolerant to acid, heat, acetic acid, and ethanol) were selected to form a cocktail starter culture that should lead to better-controlled and more-reliable cocoa bean fermentation processes. PMID:22636007

Effect of starter cultures and packaging methods on amino acid profile and eating quality characteristics of pork ham.

PubMed

Gogoi, Protiva; Borpuzari, R N; Borpuzari, T; Hazarika, R A; Bora, J R

2015-08-01

Wet cured pork hams were inoculated with a mixed starter cultures comprising of Lactobacillus acidophilus and Micrococcus varians M483 at the dose level of 106 cfu/g and the un inoculated hams served as controls. The amino acid profile of hams of the treated and the control groups stored at 4oC under MAP and VP and evaluated on 60th day of storage revealed that treated hams liberated higher concentration of free amino acids except for proline and methionine which were found in higher concentration (P < 0.01) in the MAP control samples. The MAP control samples liberated glutamic acid (85.65 ± 1.40 ppm), cystine (21.56 ± 1.14 ppm) and tyrosine (16.63 ± 1.94 ppm) whereas, the treated samples did not release these amino acids. The VP control samples too liberated cystine (6.98 ± 1.36 ppm) and arginine (42.70 ± 2.78 ppm) but the treated ham of the VP did not liberate these amino acids. The VP hams had higher concentration (P < 0.01) of free proline, glycine, alanine, valine, methionine, isoleucine, phenylalanine, lysine and histidine than the MAP samples. Colour analysis of ham using CIE Lab colour system revealed that the treated samples had significantly higher concentrations of L*, a* and b* components. The L* and a* values were higher in the MAP than under VP systems while the b* values were higher in the VP samples than the MAP samples. Neither the bacterial cultures nor the packaging system influenced the textural property of ham. Starter cultures inoculated hams were rated superior (P < 0.05) in terms of their sensory properties. Hams packaged under MAP were rated superior (P < 0.05) than those packaged under VP in terms of appearance, colour, taste, tenderness, flavour, juiciness and overall acceptability.

Contribution of starter cultures to the proteolytic process of a fermented non-dried whole muscle ham product.

PubMed

Scannell, Amalia G M; Kenneally, Paul M; Arendt, Elke K

2004-06-01

Porcine longissimus dorsi muscles were cured by brine injection. Curing brine containing 15% (w/v) NaCl, 1.33% (w/v) glucose, 750 ppm sodium nitrite, and appropriate levels of either Lactobacillus sakei LAD, L. sakei LAD plus Kocuria varians FT4 (formally Micrococcus varians), L. sakei LAD plus papain and GDL (glucono-delta-lactone) plus K. varians FT4, was injected to the muscle at a pumping rate 15% w/v. The effect of these treatments on the proteolysis in the ham system was compared to a control ham, produced without starter culture and containing GDL acidulant to control pH and antibiotics to reduce the contribution of background microflora. Hydrolysis of sarcoplasmic and myofibrillar protein fractions was evaluated by SDS-PAGE and reverse phase-HPLC. Hams with different treatments were also investigated for differences in amino acid profile, protein and non-protein nitrogen level, colour, pH, water activity and moisture and microbiological evolution. There was no significant difference in the gross compositional analysis of any of the treatments compared to the control. There was no significant difference (p>0.05) in the protein content, non-protein nitrogen level, SDS-PAGE and free amino acid analysis between the control ham and ham inoculated with proteolytic starter culture. However, it was observed that hams containing starter cultures exhibited decreases in certain peptide fractions and corresponding increases in some free amino acids compared to the uninoculated control. It can be concluded that, while the principle mechanisms resulting in the proteolysis of this non-dried ham product involve the activity of endogeneous cathepsins, the addition of proteolytic starter cultures influence the amino acid profile thereby potentially enhancing the sensorial attributes of the ham. Copyright 2004 Elsevier B.V.

Susceptibility of nine organophosphorus pesticides in skimmed milk towards inoculated lactic acid bacteria and yogurt starters.

PubMed

Zhou, Xin-Wei; Zhao, Xin-Huai

2015-01-01

Previous research has shown that fresh milk might be polluted by some organophosphorus pesticides (OPPs). In this study the dissipation of nine OPPs, namely chlorpyrifos, chlorpyrifos-methyl, diazinon, dichlorvos, fenthion, malathion, phorate, pirimiphos-methyl and trichlorphon, in skimmed milk was investigated to clarify their susceptibility towards lactic acid bacteria (LAB) and yogurt starters. Skimmed milk was spiked with nine OPPs, inoculated with five strains of LAB and two commercial yogurt starters at 42 °C for 24 and 5 h respectively and subjected to quantitative OPP analysis by gas chromatography. Degradation kinetic constants of these OPPs were calculated based on a first-order reaction model. OPP dissipation in the milk was enhanced by the inoculated strains and starters, resulting in OPP concentrations decreasing by 7.0-64.6 and 7.4-19.2% respectively. Totally, the nine OPPs were more susceptible to Lactobacillus bulgaricus, as it enhanced their degradation rate constants by 18.3-133.3%. Higher phosphatase production of the assayed stains was observed to bring about greater OPP degradation in the milk. Both LAB and yogurt starters could enhance OPP dissipation in skimmed milk, with the nine OPPs studied having different susceptibilities towards them. Phosphatase was a key factor governing OPP dissipation. The LAB of higher phosphatase production have more potential to decrease OPPs in fermented foods. © 2014 Society of Chemical Industry.

Effect of temperature on microbial composition of starter culture for Chinese light aroma style liquor fermentation.

PubMed

Wang, H Y; Xu, Y

2015-01-01

Light aroma style liquor is one of the basic types of Chinese liquor and is produced with a special technique of using a combination of three types of Daqu as starter culture. The succession of incubation temperature, a main operating parameter, and microbial composition in Daqu were investigated during the manufacturing process. The most significant difference in temperature occurred during the middle stage at which the highest and the lowest temperatures were detected in Houhuo (HH) and Qingcha (QC), respectively. It was shown that for the counting data, the population of fungi was identical and that of bacteria was different between three types of Daqu. According to analysis results of microbial community structure using PCR-denaturing gradient gel electrophoresis (PCR-DGGE), lactic acid bacteria were one of the dominant bacterial groups in all of Daqu and fungal diversity in QC was higher than that in HH and Hongxin (HX). The difference in incubation temperature led to the accumulation of different heat-tolerant and heat-sensitive fungi in the completed Daqu. PCA of DGGE profiles revealed that microbial community structure was distinct between three types of Daqu. It was presumed that temperature might play a decisive role in the formation of micro-organism composition in starter cultures. The usage of a combination of three types of Daqu including Qingcha, Hongxin and Houhuo as starter culture is an important characteristic of production technology of Chinese light aroma style liquor. Micro-organisms from the environment naturally inoculated in Daqu are propagated to form the special microbial community under the control of several operating parameters, especially temperature, and finally play various roles in the fermentation process of liquor. An in-depth study of the relationship between incubation temperature and microbiota in Daqu during the manufacturing is fundamental to understand this complicated process and to prepare high-quality starter culture for

Inhibitory effect of essential oils against Lactobacillus rhamnosus and starter culture in fermented milk during its shelf-life period

PubMed Central

Moritz, Cristiane Mengue Feniman; Rall, Vera Lúcia Mores; Saeki, Margarida Júri; Júnior, Ary Fernandes

2012-01-01

The use of essential oils in foods has attracted great interest, due to their antagonistic action against pathogenic microorganisms. However, this action is undesirable for probiotic foods, as products containing Lactobacillus rhamnosus. The aim of the present study was to measure the sensitivity profile of L. rhamnosus and a yogurt starter culture in fermented milk, upon addition of increasing concentrations of cinnamon, clove and mint essential oils. Essential oils were prepared by steam distillation, and chemically characterised by gas chromatography-mass spectrometry (GC-MS) and determination of density. Survival curves were obtained from counts of L. rhamnosus and the starter culture (alone and in combination), upon addition of 0.04% essential oils. In parallel, titratable acidity was monitored over 28 experimental days. Minimum inhibitory concentration values, obtained using the microdilution method in Brain Heart Infusion medium, were 0.025, 0.2 and 0.4% for cinnamon, clove and mint essential oils, respectively. Cinnamon essential oil had the highest antimicrobial activity, especially against the starter culture, interfering with lactic acid production. Although viable cell counts of L. rhamnosus were lower following treatment with all 3 essential oils, relative to controls, these results were not statistically significant; in addition, cell counts remained greater than the minimum count of 108CFU/mL required for a product to be considered a probiotic. Thus, although use of cinnamon essential oil in yogurt makes starter culture fermentation unfeasible, it does not prevent the application of L. rhamnosus to probiotic fermented milk. Furthermore, clove and mint essential oil caused sublethal stress to L. rhamnosus. PMID:24031939

Improvement in sensory characteristics of Campbell Early wine by adding dual starters of Saccharomyces cerevisiae and Oenococcus oeni.

PubMed

Yoo, Ki-Seon; Kim, Ji Eun; Seo, Eun-Young; Kim, Yu Jin; Choi, Hwa Young; Yoon, Hyang-Sik; Kim, Myoung-Dong; Han, Nam Soo

2010-07-01

This study was performed to investigate the effects of adding a dual starter on the chemical and sensory characteristics of red wine made of Campbell Early grape. The yeast starter, Saccharomyces cerevisiae, and lactic acid bacteria (LAB) starter, Oenococcus oeni, were used for inoculation in the winemaking process for alcoholic and malolactic fermentation (MLF), respectively. After 200 days incubation, the chemical compositions of yeast/LAB-added wine (YL-wine) were compared with those of no starter-added wine (control) and yeast-added wine (Y-wine). The results show that no significant differences were observed in pH, total sugar, and alcohol content among wine samples, but the malic acid content in YL-wine was significantly reduced and various esters and higher alcohols were synthesized. The sensory test revealed that the addition of dual starters resulted in improved overall acceptability in wine. This study emphasizes the importance of O. oeni in addition to yeast in making Campbell Early wine.

Antibiotic susceptibility patterns and resistance genes of starter cultures and probiotic bacteria used in food.

PubMed

Kastner, Sabine; Perreten, Vincent; Bleuler, Helen; Hugenschmidt, Gabriel; Lacroix, Christophe; Meile, Leo

2006-03-01

A survey of starter and probiotic cultures was carried out to determine the current antibiotic resistance situation in microbial food additives in Switzerland. Two hundred isolates from 90 different sources were typed by molecular and other methods to belong to the genera Lactobacillus (74 samples), Staphylococcus (33 samples), Bifidobacterium (6 samples), Pediococcus (5 samples), or were categorized as lactococci or streptococci (82 samples). They were screened for phenotypic resistances to 20 antibiotics by the disk diffusion method. Twenty-seven isolates exhibiting resistances that are not an intrinsic feature of the respective genera were further analyzed by microarray hybridization as a tool to trace back phenotypic resistances to specific genetic determinants. Their presence was finally verified by PCR amplification or Southern hybridization. These studies resulted in the detection of the tetracycline resistance gene tet(K) in 5 Staphylococcus isolates used as meat starter cultures, the tetracycline resistance gene tet(W) in the probiotic cultures Bifidobacterium lactis DSM 10140 and Lactobacillus reuteri SD 2112 (residing on a plasmid), and the lincosamide resistance gene lnu(A) (formerly linA) in L. reuteri SD 2112.

Characterization of lactic acid bacteria isolated from infant faeces as potential probiotic starter cultures for fermented sausages.

PubMed

Rubio, Raquel; Jofré, Anna; Martín, Belén; Aymerich, Teresa; Garriga, Margarita

2014-04-01

A total of 109 lactic acid bacteria isolated from infant faeces were identified by partial 16S rRNA, cpn60 and/or pheS sequencing. Lactobacillus was the most prevalent genus, representing 48% of the isolates followed by Enterococcus (38%). Lactobacillus gasseri (21%) and Enterococcus faecalis (38%) were the main species detected. A further selection of potential probiotic starter cultures for fermented sausages focused on Lactobacillus as the most technologically relevant genus in this type of product. Lactobacilli strains were evaluated for their ability to grow in vitro in the processing conditions of fermented sausages and for their functional and safety properties, including antagonistic activity against foodborne pathogens, survival from gastrointestinal tract conditions (acidity, bile and pancreatin), tyramine production, antibiotic susceptibility and aggregation capacity. The best strains according to the results obtained were Lactobacillus casei/paracasei CTC1677, L. casei/paracasei CTC1678, Lactobacillus rhamnosus CTC1679, L. gasseri CTC1700, L. gasseri CTC1704, Lactobacillus fermentum CTC1693. Those strains were further assayed as starter cultures in model sausages. L. casei/paracasei CTC1677, L. casei/paracasei CTC1678 and L. rhamnosus CTC1679 were able to lead the fermentation and dominate (levels ca. 10(8) CFU/g) the endogenous lactic acid bacteria, confirming their suitability as probiotic starter cultures. Copyright © 2013 Elsevier Ltd. All rights reserved.

Preparation of a Lactobacillus plantarum starter culture for cucumber fermentations that can meet kosher guidelines

USDA-ARS?s Scientific Manuscript database

A method is described for growth of a Lactobacillus plantarum starter culture in jars of commercially available pasteurized fresh-pack kosher dill cucumbers so that jars can be used to inoculate commercial scale cucumber fermentation tanks. A procedure is also described to transfer lactic acid bacte...

The production of glucans via glucansucrases from Lactobacillus satsumensis isolated from a fermented beverage starter culture

USDA-ARS?s Scientific Manuscript database

Several starter cultures used in the production of fermented beverages were screened for lactic acid bacteria that produced water-insoluble polysaccharides from sucrose. The strain producing the greatest amount was identified as Lactobacillus satsumensis by its 16S RNA sequence. This strain produc...

Genome Sequence of Lactobacillus sakei subsp. sakei LS25, a Commercial Starter Culture Strain for Fermented Sausage.

PubMed

McLeod, Anette; Brede, Dag Anders; Rud, Ida; Axelsson, Lars

2013-07-11

Lactobacillus sakei is a lactic acid bacterium associated primarily with fermented meat and fish. Here, we present the draft genome sequence of L. sakei subsp. sakei strain LS25, a commercial starter culture strain for fermented sausage.

Biodiversity and growth dynamics of lactic acid bacteria in artisanal PDO Ossau-Iraty cheeses made from raw ewe's milk with different starters.

PubMed

Feutry, Fabienne; Oneca, María; Berthier, Françoise; Torre, Paloma

2012-02-01

The biodiversity and growth dynamics of Lactic Acid Bacteria (LAB) in farm-house Ossau-Iraty cheeses were investigated from vat milk to 180 days of ripening in six independent batches made from six raw ewe's milks using five typical cheese-making methods. Commercial starter S1 was used for three batches, starter S1 combined with S2 for one batch and no starter for two batches. Up to ten LAB species from five genera and up to two strains per species were identified per milk; up to eleven species from five genera and up to three strains per species were identified per cheese. Lactococcus lactis, Lactobacillus paracasei, Enterococcus faecalis, Enterococcus faecium, Enterococcus durans, and Leuconostoc mesenteroides were detected in all cheeses. Lactococci reached the highest counts irrespective of the milk and starter used. Lactococci and enterococci increased during manufacture, and mesophilic lactobacilli increased during ripening. Strain and species numbers, the percentage of isolates originating from the raw milk, maximum counts of each genus/species and time for reaching them, all varied according to whether or not a starter was used and the composition of the starter. The genotypes of strains within species varied according to the raw milk used. This generated distinct LAB microbiotas throughout manufacture and ripening that will certainly impact on the characteristics of the ripened cheeses. Copyright © 2011 Elsevier Ltd. All rights reserved.

Microbiological characterization of traditional dough fermentation starter (Jiaozi) for steamed bread making by culture-dependent and culture-independent methods.

PubMed

Li, Zhijian; Li, Haifeng; Bian, Ke

2016-10-03

In this study, the microbial composition of two types of Jiaozi (a dough fermentation starter in making steamed bread) was investigated using both culture-dependent and culture-independent (PCR-DGGE) methods. The numbers of the cultivable bacteria on MRS at 30°C and yeast on YPD at 28°C in the maize flour Jiaozi (MFJ) were 9.21±0.16 Log CFU/g and 9.18±0.05 Log CFU/g, respectively, which were higher than that in the rice flour Jiaozi (RFJ) (P<0.05). A total of 140 bacteria and 124 yeasts were isolated and identified on the basis of the sequences of their 16S rRNA gene and ITS region. The culture-dependent method showed that Acetobacter tropicalis and Enterococcus durans were the predominant bacteria strains in MFJ, and accounted for 45.7% and 25.7% of the bacteria, and Lactobacillus plantarum and Pediococcus pentosaceus represented 12.8% and 8.6%. In the RFJ sample, the most prominent isolate was P. pentosaceus (38.6%), followed by L. plantarum (24.3%), A. tropicalis (22.8%), and E. durans (5.7%). P. pentosaceus and L. plantarum were also detected in both starters by PCR-DGGE, while some bacteria species such as A. tropicalis and E. durans, recovered as pure cultures, were not detected by direct PCR-DGGE. On the other hand, Lactobacillus brevis, Weissella sp. and Lactobacillus alimentarius detected by PCR-DGGE were not recovered in any of the media and conditions used. In the MFJ sample, the isolated main yeast species were identified as Wickerhamomyces anomalus (67.2%), Saccharomyces cerevisiae (27.9%) and Torulaspora delbrueckii (4.9%). In addition to S. cerevisiae (42.9%), W. anomalus (27.0%) and T. delbrueckii (7.9%), Saccharomycopsis fibuligera was also identified as the predominant isolate in RFJ samples and accounted for 22.2%. PCR-DGGE also indicated the presence of W. anomalus and S. cerevisiae in both MFJ and RFJ starters and S. fibuligera was also detected in RFJ, but T. delbrueckii was not detected in both samples. Copyright © 2016 Elsevier B.V. All

Rapid detection of bacteriophages in starter culture using water-in-oil-in-water emulsion microdroplets.

PubMed

Wang, Min S; Nitin, Nitin

2014-10-01

Bacteriophage contamination of starter culture and raw material poses a major problem in the fermentation industry. In this study, a rapid detection of lytic phage contamination in starter culture using water-in-oil-in-water (W/O/W) emulsion microdroplets was described. A model bacteria with varying concentrations of lytic phages were encapsulated in W/O/W emulsion microdroplets using a simple needle-in-tube setup. The detection of lytic phage contamination was accomplished in 1 h using the propidium iodide labeling of the phage-infected bacteria inside the W/O/W emulsion microdroplets. Using this approach, a detection limit of 10(2) PFU/mL of phages was achieved quantitatively, while 10(4) PFU/mL of phages could be detected qualitatively based on visual comparison of the fluorescence images. Given the simplicity and sensitivity of this approach, it is anticipated that this method can be adapted to any strains of bacteria and lytic phages that are commonly used for fermentation, and has potential for a rapid detection of lytic phage contamination in the fermentation industry.

Characterization of certain bacterial strains for potential use as starter or probiotic cultures in dairy products.

PubMed

Monteagudo-Mera, A; Caro, I; Rodríguez-Aparicio, L B; Rúa, J; Ferrero, M A; García-Armesto, M R

2011-08-01

The present work was aimed at characterizing 12 strains of lactic acid bacteria (LAB) to obtain improved potential starter or probiotic cultures that could be used for making dairy products from ewe's milk and cow's milk. Eight strains with antimicrobial properties, isolated from ewe's milk and from cheese made from ewe's and/or cow's milk, were studied. They were identified as Enterococcus faecalis (five strains), Lactococcus lactis subsp. cremoris, Leuconostoc mesenteroides, and Lactobacillus paracasei subsp. paracasei (one strain of each species). Additionally, four strains were obtained from the American Type Culture Collection: Lactobacillus casei 393 (isolated from cheese), L. lactis subsp. lactis 11454 (origin nonspecified and a producer of nisin), and two strains isolated from human feces (L. paracasei subsp. paracasei 27092 and Lactobacillus rhamnosus 53103, antibacterial agent producer). All E. faecalis strains showed at least one virulence factor (either hemolysin or gelatinase), which emphasizes the importance of these studies in this species. Both L. lactis strains and most Lactobacillus spp. were good acidifiers in ewe's milk and cow's milk at 30°C. High β-galactosidase activity, as well as aminopeptidase activities that favor the development of desirable flavors in cheese, were detected in all Lactobacillus spp. strains. Furthermore, L. rhamnosus ATCC 53103 showed α-fucosidase activity (thought to help colonization of the intestine) and lack of α-glucosidase activity (a trait considered positive for diabetic and obese humans). This last enzymatic activity was also lacking in L. lactis ATCC 11454. L. mesenteroides was the only strain D(2)-lactic acid producer. The selection of any particular strain for probiotic or dairy cultures should be performed according to the technological and/or functional abilities needed.

Performance of two potential probiotic Lactobacillus strains from the olive microbiota as starters in the fermentation of heat shocked green olives.

PubMed

Argyri, Anthoula A; Nisiotou, Aspasia A; Mallouchos, Athanasios; Panagou, Efstathios Z; Tassou, Chrysoula C

2014-02-03

The performance of two potential probiotic Lactobacillus strains from olive microbiota, namely L. pentosus B281 and L. plantarum B282 was assessed as starter cultures in Spanish-style fermentation of heat shocked green olives cv. Halkidiki. Two different initial salt levels were studied, 10% (w/v) and 8% (w/v) NaCl, and the brines were inoculated with (a) L. pentosus B281, (b) L. plantarum B282, and (c) a mixture of both strains. A spontaneous fermentation was also taken into account as control treatment. Prior to brining, olives were heat shocked at 80 °C for 10 min to reduce the level of the indigenous microbiota on olive drupes and facilitate the dominance of the inoculated cultures. Microbiological, physicochemical and sensory analyses were conducted throughout fermentation. The composition of LAB population and the evolution of added inocula were assessed by Pulsed Field Gel Electrophoresis (PFGE). The final population of LAB was maintained above 6 log cycles in olive flesh. Both L. pentosus B281 and L. plantarum B282 were able to dominate over indigenous LAB, albeit strain B281 exhibited higher recovery percentages (100 or 94.7% for B281 and 58.8% or 55.0% for B282 in 10% or 8% NaCl, respectively). L. pentosus B281 also dominated over L. plantarum B282, when the two strains were co-inoculated in olive fermentations. The sensory assessment showed higher preference for inoculated fermentations of L. pentosus and L. plantarum separately in 8% NaCl, followed by the L. plantarum in 10% NaCl. The present study showed that probiotic strains L. pentosus B281 and L. plantarum B282, may offer a great potential for use as functional starter cultures in olive fermentation and deliver a promising probiotic food to the consumer. Copyright © 2013 Elsevier B.V. All rights reserved.

Influence of starter culture ratios and warm room treatment on free fatty acid and amino acid in Swiss cheese.

PubMed

Ji, T; Alvarez, V B; Harper, W J

2004-07-01

Quantification of water-soluble volatile free fatty acids (FFA) and free amino acids (FAA) was performed as a ripening index and an indirect measure of flavor development in Swiss-type cheeses. The objective of this research was to assess the effect of warm room treatment (WRT) and usage ratio of starter cultures, Streptococcus thermophilus and Lactobacillus helveticus vs. propionibacteria, on the concentration of FFA and FAA in pilot plant-scale Swiss cheese. A capillary gas chromatograph equipped with a flame ionization detector was used for the analysis of FFA in Swiss cheese. Free amino acids were analyzed by the Cd-ninhydrin method. Starter culture ratios did not affect development of FAA during the cheese ripening. However, duration of WRT had an effect on the concentration of FAA in the Swiss cheese. Free amino acids increased considerably during WRT. A continuous increase in FAA was shown during 70-d ripening time after WRT. The concentrations of C2:0 and C3:0 fatty acids were affected by starter culture ratios after 2-wk WRT, but these differences had mostly disappeared after 3-wk WRT. Similar concentrations of FFA and FAA reported in previous studies were developed in Swiss cheese with a 3-wk WRT and a 0.33:1 ratio of Streptococcus thermophilus and Lactobacillus helveticus to propionibacteria.

Bacteriocinogenic LAB Strains for Fermented Meat Preservation: Perspectives, Challenges, and Limitations.

PubMed

Favaro, Lorenzo; Todorov, Svetoslav Dimitrov

2017-12-01

Over the last decades, much research has focused on lactic acid bacteria (LAB) bacteriocins because of their potential as biopreservatives and their action against the growth of spoilage microbes. Meat and fermented meat products are prone to microbial contamination, causing health risks, as well as economic losses in the meat industry. The use of bacteriocin-producing LAB starter or protective cultures is suitable for fermented meats. However, although bacteriocins can be produced during meat processing, their levels are usually much lower than those achieved during in vitro fermentations under optimal environmental conditions. Thus, the direct addition of a bacteriocin food additive would be desirable. Moreover, safety and technological characteristics of the bacteriocinogenic LAB must be considered before their widespread applications. This review describes the perspectives and challenges toward the complete disclosure of new bacteriocins as effective preservatives in the production of safe and "healthy" fermented meat products.

Starter culture development for improving safety and quality of Domiati cheese.

PubMed

Ayad, Eman H E

2009-08-01

Eleven lactococci strains (sp. lactis and cremoris) were collected according to specific or selected characteristics for development of defined strain starter (DSS) to improve safety and nutritional quality of traditional and low salt Domiati cheese. Thirteen DSS; nisin-producing system or/and folate-producing strains were prepared. The behaviour of the strains in DSS was studied in milk and in two series of Domiati cheese; the first one made with 5% NaCl and salt tolerant strains, the second made with 3% NaCl and the control cheeses were made without starters. The population dynamics of strains and sensory evaluation of cheese corroborated the results in milk. All strains can grow well together and appeared to produce pleasant flavours, normal (typical) body and texture Domiati cheese. There was no apparent difference in cheese composition between cheeses in each series; the levels were within margins for composition of Domiati cheese. The levels of nisin (IU g(-1)) ranged from 204 to 324 IU g(-1) in 3-months' cheeses. Folate concentration increased in cheeses made with DSS cultures than control and the level ranged from 5.5 to 11.1 microg 100 g(-1) in cheeses after 3 months. All results revealed that selected DSS can be used for improving Domiati cheese.

Cultivability of Streptococcus thermophilus in Grana Padano cheese whey starters.

PubMed

Fornasari, Maria Emanuela; Rossetti, Lia; Carminati, Domenico; Giraffa, Giorgio

2006-04-01

The application of a culture-independent approach, that of reverse transcriptase-length heterogeneity-PCR coupled with epifluorescence microscopy, allowed us to observe that Streptococcus thermophilus is metabolically active, but only partially cultivable in Grana Padano cheese whey starters. A short preincubation of the starters in sterile skimmed whey was followed by cultivation in sterile skimmed whey-enriched M17. This procedure restored the cultivability of S. thermophilus and enabled us to detect S. thermophilus at ranges (10(7)-10(8) CFU mL(-1)) which have rarely been reported in these cultures. The use of cheese whey as a cultivation-revitalization substrate can be useful to obtain an unbiased picture of the microbial composition of whey starters for Grana Padano cheese, thus avoiding an underestimation of S. thermophilus in these cultures.

A qualified presumption of safety approach for the safety assessment of Grana Padano whey starters.

PubMed

Rossetti, Lia; Carminati, Domenico; Zago, Miriam; Giraffa, Giorgio

2009-03-15

A Qualified Presumption of Safety (QPS) approach was applied to dominant lactic acid bacteria (LAB) associated with Grana Padano cheese whey starters. Thirty-two strains belonging to Lactobacillus helveticus, Lactobacillus delbrueckii subsp. lactis, Streptococcus thermophilus, and Lactobacillus fermentum, and representing the overall genotypic LAB diversity associated with 24 previously collected whey starters [Rossetti, L., Fornasari, M.E., Gatti, M., Lazzi, C., Neviani, E., Giraffa, G., 2008. Grana Padano cheese whey starters: microbial composition and strain distribution. International Journal of Food Microbiology 127, 168-171], were analyzed. All L. helveticus, L. delbrueckii subsp. lactis, and S. thermophilus isolates were susceptible to four (i.e. vancomycin, gentamicin, tetracycline, and erythromycin) of the clinically most relevant antibiotics. One L. fermentum strain displayed phenotypic resistance to tetracycline (Tet(R)), with MIC of 32 microg/ml, and gentamycin (Gm(R)), with MIC of 32 microg/ml. PCR was applied to this strain to test the presence of genes tet(L), tet(M), tet(S), and aac(6')-aph(2')-Ia, which are involved in horizontal transfer of Tet(R) and Gm(R), respectively but no detectable amplification products were observed. According to QPS criteria, we conclude that Grana cheese whey starters do not present particular safety concerns.

Spray-dried adjunct cultures of autochthonous non-starter lactic acid bacteria.

PubMed

Peralta, Guillermo H; Bergamini, Carina V; Audero, Gabriela; Páez, Roxana; Wolf, I Verónica; Perotti, M Cristina; Hynes, Erica R

2017-08-16

Spray-drying of lactic cultures provides direct-to-vat starters, which facilitate their commercialization and use. However, this process may alter the metabolic activity and deteriorate technological features. In this work, we assessed the influence of spray-drying on the survival and aroma production of two strains of mesophilic lactobacilli: Lactobacillus paracasei 90 and Lactobacillus plantarum 91, which have already been characterized as good adjunct cultures. The spray-drying was carried out using a laboratory scale spray and the dried cultures were monitored during the storage for the survival rate. The dried cultures were applied to two cheese models: sterile cheese extract and miniature soft cheese. The influence on the carbohydrate metabolism and the production of organic acids and volatile compounds was determined. Both strains retained high levels of viable counts in the powder after drying and during the storage at 5°C for twelve months. In addition, they also remained at high level in both cheese models during incubation or ripening. Similar profiles of carbohydrate fermentation and bioformation of volatile compounds were observed in the cheese extracts for each of the strains when tested as both fresh and dried cultures. In addition, the ability of Lb. paracasei 90 to increase the production of acetoin and diacetyl remarkably in cheese models was also confirmed for the spray-dried culture. Copyright © 2017 Elsevier B.V. All rights reserved.

Starter Culture Selection for Making Chinese Sesame-Flavored Liquor Based on Microbial Metabolic Activity in Mixed-Culture Fermentation

PubMed Central

Wu, Qun; Ling, Jie

2014-01-01

Selection of a starter culture with excellent viability and metabolic activity is important for inoculated fermentation of traditional food. To obtain a suitable starter culture for making Chinese sesame-flavored liquor, the yeast and bacterium community structures were investigated during spontaneous and solid-state fermentations of this type of liquor. Five dominant species in spontaneous fermentation were identified: Saccharomyces cerevisiae, Pichia membranaefaciens, Issatchenkia orientalis, Bacillus licheniformis, and Bacillus amyloliquefaciens. The metabolic activity of each species in mixed and inoculated fermentations of liquor was investigated in 14 different cocultures that used different combinations of these species. The relationships between the microbial species and volatile metabolites were analyzed by partial least-squares (PLS) regression analysis. We found that S. cerevisiae was positively correlated to nonanal, and B. licheniformis was positively associated with 2,3-butanediol, isobutyric acid, guaiacol, and 4-vinyl guaiacol, while I. orientalis was positively correlated to butyric acid, isovaleric acid, hexanoic acid, and 2,3-butanediol. These three species are excellent flavor producers for Chinese liquor. Although P. membranaefaciens and B. amyloliquefaciens were not efficient flavor producers, the addition of them alleviated competition among the other three species and altered their growth rates and flavor production. As a result, the coculture of all five dominant species produced the largest amount of flavor compounds. The result indicates that flavor producers and microbial interaction regulators are important for inoculated fermentation of Chinese sesame-flavored liquor. PMID:24814798

Quantification of viable bacterial starter cultures of Virgibacillus sp. and Tetragenococcus halophilus in fish sauce fermentation by real-time quantitative PCR.

PubMed

Udomsil, Natteewan; Chen, Shu; Rodtong, Sureelak; Yongsawatdigul, Jirawat

2016-08-01

Real-time quantitative polymerase chain reaction (qPCR) methods were developed for the quantification of Virgibacillus sp. SK37 and Tetragenococcus halophilus MS33, which were added as starter cultures in fish sauce fermentation. The PCR assays were coupled with propidium monoazide (PMA) treatment of samples to selectively quantify viable cells and integrated with exogenous recombinant Escherichia coli cells to control variabilities in analysis procedures. The qPCR methods showed species-specificity for both Virgibacillus halodenitrificans and T. halophilus as evaluated using 6 reference strains and 28 strains of bacteria isolated from fish sauce fermentation. The qPCR efficiencies were 101.1% for V. halodenitrificans and 90.2% for T. halophilus. The quantification limits of the assays were 10(3) CFU/mL and 10(2) CFU/mL in fish sauce samples with linear correlations over 4 Logs for V. halodenitrificans and T. halophilus, respectively. The matrix effect was not observed when evaluated using fish sauce samples fermented for 1-6 months. The developed PMA-qPCR methods were successfully applied to monitor changes of Virgibacillus sp. SK37 and T. halophilus MS33 in a mackerel fish sauce fermentation model where culture-dependent techniques failed to quantify the starter cultures. The results demonstrated the usability of the methods as practical tools for monitoring the starter cultures in fish sauce fermentation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Competitiveness and antibacterial potential of bacteriocin-producing starter cultures in different types of fermented sausages.

PubMed

Ravyts, Frédéric; Barbuti, Silvana; Frustoli, Maria Angela; Parolari, Giovanni; Saccani, Giovanna; De Vuyst, Luc; Leroy, Frédéric

2008-09-01

Application of bacteriocin-producing starter cultures of lactic acid bacteria in fermented sausage production contributes to food safety. This is sometimes hampered by limited efficacy in situ and by uncertainty about strain dependency and universal applicability for different sausage types. In the present study, a promising antilisterial-bacteriocin producer, Lactobacillus sakei CTC 494, was applied as a coculture in addition to commercial fermentative starters in different types of dry-fermented sausages. The strain was successful in both Belgian-type sausage and Italian salami that were artificially contaminated with about 3.5 log CFU g(-1) of Listeria monocytogenes. After completion of the production process, this led to listerial reductions of up to 1.4 and 0.6 log CFU g(-1), respectively. In a control sausage, containing only the commercial fermentative starter, the reduction was limited to 0.8 log CFU g(-1) for the Belgian-type recipe, where pH decreased from 5.9 to 4.9, whereas an increase of 0.2 log CFU g(-1) was observed for Italian salami, in which the pH rose from 5.7 to 5.9 after an initial decrease to pH 5.3. In a Cacciatore recipe inoculated with 5.5 log CFU g(-1) of L. monocytogenes and in the presence of L. sakei CTC 494, there was a listerial reduction of 1.8 log CFU g(-1) at the end of the production process. This was superior to the effect obtained with the control sausage (0.8 log CFU g(-1)). Two commercial antilisterial cultures yielded reductions of 1.2 and 1.5 log CFU g(-1). Moreover, repetitive DNA sequence-based PCR fingerprinting demonstrated the competitive superiority of L. sakei CTC 494.

Biodiversity among Lactobacillus helveticus Strains Isolated from Different Natural Whey Starter Cultures as Revealed by Classification Trees

PubMed Central

Gatti, Monica; Trivisano, Carlo; Fabrizi, Enrico; Neviani, Erasmo; Gardini, Fausto

2004-01-01

Lactobacillus helveticus is a homofermentative thermophilic lactic acid bacterium used extensively for manufacturing Swiss type and aged Italian cheese. In this study, the phenotypic and genotypic diversity of strains isolated from different natural dairy starter cultures used for Grana Padano, Parmigiano Reggiano, and Provolone cheeses was investigated by a classification tree technique. A data set was used that consists of 119 L. helveticus strains, each of which was studied for its physiological characters, as well as surface protein profiles and hybridization with a species-specific DNA probe. The methodology employed in this work allowed the strains to be grouped into terminal nodes without difficult and subjective interpretation. In particular, good discrimination was obtained between L. helveticus strains isolated, respectively, from Grana Padano and from Provolone natural whey starter cultures. The method used in this work allowed identification of the main characteristics that permit discrimination of biotypes. In order to understand what kind of genes could code for phenotypes of technological relevance, evidence that specific DNA sequences are present only in particular biotypes may be of great interest. PMID:14711641

The substitution of a traditional starter culture in mutton fermented sausages by Lactobacillus acidophilus and Bifidobacterium animalis.

PubMed

Holko, I; Hrabě, J; Šalaková, A; Rada, V

2013-07-01

Common starter cultures used in fermented mutton sausages were substituted by probiotic strains of Lactobacillus acidophilus CCDM 476 and Bifidobacterium animalis 241a. Technological properties of the traditional and the probiotic sausages were compared. The potential probiotic effect was evaluated by enumeration of bifidobacteria and lactobacilli in stool samples of 15 volunteers before and after a 14-day consumption period. The numbers of lactobacilli (10(7) cfu/g) and bifidobacteria (10(3) cfu/g) in the final product did not affect the technological properties. The use of L. acidophilus as a starter culture was found more beneficial than the use of B. animalis. Even after 60 days of storage, high counts of L. acidophilus (10(6) cfu/g) were detected; on the other hand, the counts of B. animalis were under the detection limit. Regarding sensory properties, the probiotic products showed better texture, and, curiously, a reduction of the typical smell of mutton. The numbers of lactobacilli in stool samples increased significantly after the consumption of the probiotic sausages. Copyright © 2013 Elsevier Ltd. All rights reserved.

Fastener Starter

NASA Technical Reports Server (NTRS)

Chandler, Faith; Garton, Harry; Valentino, Bill; Amett, Mike

2005-01-01

The Fastener Starter is a creative solution to prevent the loss of small fasteners during their installation. This is the only currently available tool that can firmly grip and hold a single screw, bolt, nut, washer, spacer, or any combination of these parts. Other commercially available fastener starters are unable to accommodate a variety of parts simultaneously. The Fastener Starter is a more capable and easier tool to use than prior tools. Its compact size allows it to be used effectively in cramped, difficult-to-see locations. Its design also allows it to be used with or without handles and extenders in other difficult-to-reach locations. It provides better protection against cross threading and loss of fasteners and associated parts. The Fastener Starter is non-magnetic and does not off-gas, thus meeting flight hardware requirements. The Fastener Starter incorporates a combination of features of several commercially available tools, providing an improved means of installing small fasteners. The Fastener Starter includes a custom molded insert that can be removed easily and replaced with a conventional tool bit (e.g., a screwdriver or hex-driver bit). When used with the insert, the Fastener Starter prevents cross threading and damage to internal threaded holes. This is achieved by allowing the fastener to slip within the tool insert when used without a conventional tool bit. Alternatively, without the insert and with a tool bit, the Fastener Starter can torque a fastener. The Fastener Starter has a square recess hole that accepts a conventional square drive handle or extension to accommodate a variety of applications by providing flexibility in handle style and length.

Optimization of Culture Medium for the Growth of Candida sp. and Blastobotrys sp. as Starter Culture in Fermentation of Cocoa Beans (Theobroma cacao) Using Response Surface Methodology (RSM).

PubMed

Mahazar, N H; Zakuan, Z; Norhayati, H; MeorHussin, A S; Rukayadi, Y

2017-01-01

Inoculation of starter culture in cocoa bean fermentation produces consistent, predictable and high quality of fermented cocoa beans. It is important to produce healthy inoculum in cocoa bean fermentation for better fermented products. Inoculum could minimize the length of the lag phase in fermentation. The purpose of this study was to optimize the component of culture medium for the maximum cultivation of Candida sp. and Blastobotrys sp. Molasses and yeast extract were chosen as medium composition and Response Surface Methodology (RSM) was then employed to optimize the molasses and yeast extract. Maximum growth of Candida sp. (7.63 log CFU mL-1) and Blastobotrys sp. (8.30 log CFU mL-1) were obtained from the fermentation. Optimum culture media for the growth of Candida sp., consist of 10% (w/v) molasses and 2% (w/v) yeast extract, while for Blastobotrys sp., were 1.94% (w/v) molasses and 2% (w/v) yeast extract. This study shows that culture medium consists of molasses and yeast extract were able to produce maximum growth of Candida sp. and Blastobotrys sp., as a starter culture for cocoa bean fermentation.

Phages of lactic acid bacteria: The role of genetics in understanding phage-host interactions and their co-evolutionary processes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mahony, Jennifer, E-mail: j.mahony@ucc.ie; Ainsworth, Stuart; Stockdale, Stephen

Dairy fermentations are among the oldest food processing applications, aimed at preservation and shelf-life extension through the use of lactic acid bacteria (LAB) starter cultures, in particular strains of Lactococcus lactis, Streptococcus thermophilus, Lactobacillus spp. and Leuconostoc spp. Traditionally this was performed by continuous passaging of undefined cultures from a finished fermentation to initiate the next fermentation. More recently, consumer demands on consistent and desired flavours and textures of dairy products have led to a more defined approach to such processes. Dairy (starter) companies have responded to the need to define the nature and complexity of the starter culture mixes,more » and dairy fermentations are now frequently based on defined starter cultures of low complexity, where each starter component imparts specific technological properties that are desirable to the product. Both mixed and defined starter culture approaches create the perfect environment for the proliferation of (bacterio)phages capable of infecting these LAB. The repeated use of the same starter cultures in a single plant, coupled to the drive towards higher and consistent production levels, increases the risk and negative impact of phage infection. In this review we will discuss recent advances in tracking the adaptation of phages to the dairy industry, the advances in understanding LAB phage-host interactions, including evolutionary and genomic aspects.« less

Potential of functional strains, isolated from traditional Maasai milk, as starters for the production of fermented milks.

PubMed

Patrignani, Francesca; Lanciotti, Rosalba; Mathara, Julius Maina; Guerzoni, Maria Elisabetta; Holzapfel, Wilhelm H

2006-03-01

The purpose of this research was the evaluation of technological features and of the ability of functional LAB strains with desirable sensory characteristics, to produce fermented milk. Eight strains of Lactobacillus plantarum, Lactobacillus acidophilus, Lactobacillus paracasei and Lactococcus lactis, isolated from Maasai traditional fermented milk in Kenya and previously tested for their probiotic properties, were selected for this investigation. Technological features such as growth kinetics in fresh heat-treated whole milk medium and survival in the final product during storage at 4 degrees C, were studied. The strains Lb. acidophilus BFE 6,059, Lb. paracasei BFE 5,264 and Lc. lactis BFE 6,049 showed the best potential and were thus selected for use as starter cultures in further trials with the objective to improve their technological performance and to optimise the sensory features of fermented milk obtained. The effects of fat (F), non-fat milk solids (S) and fermentation temperature (T), modulated according to a Central Composite Design, on fermentation rates and viability losses during refrigerated storage of the chosen starters, and on product texture parameters, were studied. From the data analysis, it was possible to select optimum conditions for enhancing positive sensory traits of final products and for improving the survival of these potentially probiotic cultures.

Characteristic of phenolic compound and antioxidant activity of fermented broccoli (Brassica oleracea L. ssp.) beverage by lactic acid bacteria (LAB)

NASA Astrophysics Data System (ADS)

Maryati, Yati; Susilowati, Agustine; Melanie, Hakiki; Lotulung, Puspa D.

2017-01-01

Broccoli (Brassica oleracea L. ssp.) has a relatively high nutrient content, especially as a source of vitamins, minerals and fiber and contain bioactive compounds that act as antioxidants. In order to increase the nutritional value and innovate new products, fermentation process involving rich-antioxidants lactic acid bacteria (LAB) was done. The aim of this study is to determine the content of bioactive components, such as total polyphenols, total acid and antioxidant activity of the mixed culture of LAB (L. bulgaricus, S. thermophulus, L. acidophilus, Bd. bifidum)-fermented broccoli extracts. Ratio of fermented broccoli extract and concentration of starter cultureLAB was varied in the range of 5, 10, 15 and 20% (v/v), and the alterations of characteristics of the fermented broccoli extract, before and after fermentation (0 and 24 hours), were evaluated. The results showed that fermentation functional beverage broccoli with different concentrations of LAB cultures affect the antioxidant activity, total polyphenols, total acid and total cell of LAB generated. The optimum conditions obtained for the highest antioxidant activity of 6.74%, at aculture concentration of 20% during fermentation time of 24 h with a pH value of 4.29, total sugar of 10.89%, total acids of 0.97%, total polyphenols of 0.076%, and total LAB of 13.02 + 0.05 log cfu /ml.

Impact of a Microbial Cocktail Used as a Starter Culture on Cocoa Fermentation and Chocolate Flavor.

PubMed

Magalhães da Veiga Moreira, Igor; de Figueiredo Vilela, Leonardo; da Cruz Pedroso Miguel, Maria Gabriela; Santos, Cledir; Lima, Nelson; Freitas Schwan, Rosane

2017-05-09

Chocolate production suffered a vast impact with the emergence of the "witches' broom" disease in cocoa plants. To recover cocoa production, many disease-resistant hybrid plants have been developed. However, some different cocoa hybrids produce cocoa beans that generate chocolate with variable quality. Fermentation of cocoa beans is a microbiological process that can be applied for the production of chocolate flavor precursors, leading to overcoming the problem of variable chocolate quality. The aim of this work was to use a cocktail of microorganisms as a starter culture on the fermentation of the ripe cocoa pods from PH15 cocoa hybrid, and evaluate its influence on the microbial communities present on the fermentative process on the compounds involved during the fermentation, and to perform the chocolate sensorial characterization. According to the results obtained, different volatile compounds were identified in fermented beans and in the chocolate produced. Bitterness was the dominant taste found in non-inoculated chocolate, while chocolate made with inoculated beans showed bitter, sweet, and cocoa tastes. 2,3-Butanediol and 2,3-dimethylpyrazine were considered as volatile compounds making the difference on the flavor of both chocolates. Saccharomyces cerevisiae UFLA CCMA 0200, Lactobacillus plantarum CCMA 0238, and Acetobacter pasteurianus CCMA 0241 are proposed as starter cultures for cocoa fermentation.

Lipolytic Changes in Fermented Sausages Produced with Turkey Meat: Effects of Starter Culture and Heat Treatment

PubMed Central

Kolsarici, Nuray; Candoğan, Kezban

2014-01-01

In this study, the effects of two different commercial starter culture mixes and processing methodologies (traditional and heat process) on the lipolytic changes of fermented sausages manufactured with turkey meat were evaluated during processing stages and storage. Free fatty acid (FFA) value increased with fermentation and during storage over 120 d in all fermented sausage groups produced with both processing methodologies (p<0.05). After drying stage, free fatty acid values of traditional style and heat processed fermented sausages were between 10.54-13.01% and 6.56-8.49%, respectively. Thiobarbituric acid (TBA) values of traditionally processed fermented sausages were between 0.220-0.450 mg·kg-1, and TBA values of heat processed fermented sausages were in a range of 0.405-0.795 mg·kg-1. Oleic and linoleic acids were predominant fatty acids in all fermented sausages. It was seen that fermented sausage groups produced with starter culture had lower TBA and FFA values in comparison with the control groups, and heat application inhibited the lipase enzyme activity and had an improving effect on lipid oxidation. As a result of these effects, heat processed fermented sausages had lower FFA and higher TBA values than the traditionally processed groups. PMID:26760744

Lipolytic Changes in Fermented Sausages Produced with Turkey Meat: Effects of Starter Culture and Heat Treatment.

PubMed

Karsloğlu, Betül; Çiçek, Ümran Ensoy; Kolsarici, Nuray; Candoğan, Kezban

2014-01-01

In this study, the effects of two different commercial starter culture mixes and processing methodologies (traditional and heat process) on the lipolytic changes of fermented sausages manufactured with turkey meat were evaluated during processing stages and storage. Free fatty acid (FFA) value increased with fermentation and during storage over 120 d in all fermented sausage groups produced with both processing methodologies (p<0.05). After drying stage, free fatty acid values of traditional style and heat processed fermented sausages were between 10.54-13.01% and 6.56-8.49%, respectively. Thiobarbituric acid (TBA) values of traditionally processed fermented sausages were between 0.220-0.450 mg·kg(-1), and TBA values of heat processed fermented sausages were in a range of 0.405-0.795 mg·kg(-1). Oleic and linoleic acids were predominant fatty acids in all fermented sausages. It was seen that fermented sausage groups produced with starter culture had lower TBA and FFA values in comparison with the control groups, and heat application inhibited the lipase enzyme activity and had an improving effect on lipid oxidation. As a result of these effects, heat processed fermented sausages had lower FFA and higher TBA values than the traditionally processed groups.

Universal lab-on-a-chip platform for complex, perfused 3D cell cultures

NASA Astrophysics Data System (ADS)

Sonntag, F.; Schmieder, F.; Ströbel, J.; Grünzner, S.; Busek, M.; Günther, K.; Steege, T.; Polk, C.; Klotzbach, U.

2016-03-01

The miniaturization, rapid prototyping and automation of lab-on-a-chip technology play nowadays a very important role. Lab-on-a-chip technology is successfully implemented not only for environmental analysis and medical diagnostics, but also as replacement of animals used for the testing of substances in the pharmaceutical and cosmetics industries. For that purpose the Fraunhofer IWS and partners developed a lab-on-a-chip platform for perfused cell-based assays in the last years, which includes different micropumps, valves, channels, reservoirs and customized cell culture modules. This technology is already implemented for the characterization of different human cell cultures and organoids, like skin, liver, endothelium, hair follicle and nephron. The advanced universal lab-on-a-chip platform for complex, perfused 3D cell cultures is divided into a multilayer basic chip with integrated micropump and application-specific 3D printed cell culture modules. Moreover a technology for surface modification of the printed cell culture modules by laser micro structuring and a complex and flexibly programmable controlling device based on an embedded Linux system was developed. A universal lab-on-a-chip platform with an optional oxygenator and a cell culture module for cubic scaffolds as well as first cell culture experiments within the cell culture device will be presented. The module is designed for direct interaction with robotic dispenser systems. This offers the opportunity to combine direct organ printing of cells and scaffolds with the microfluidic cell culture module. The characterization of the developed system was done by means of Micro-Particle Image Velocimetry (μPIV) and an optical oxygen measuring system.

Starter/generator testing

NASA Astrophysics Data System (ADS)

Anon

1994-10-01

Sundstrand Aerospace and GE Aircraft Engines have studied the switched reluctance machine for use as an integral starter/generator for future aircraft engines. They have conducted an initial, low-power testing of the starter/generator, which is based on power inverters using IGBT-technology semiconductors, to verify its feasibility in the externally mounted version of the integral starter/generator. This preliminary testing of the 250-kW starter/generator reveals favorable results.

The dominant microbial community associated with fermentation of Obushera (sorghum and millet beverages) determined by culture-dependent and culture-independent methods.

PubMed

Mukisa, Ivan M; Porcellato, Davide; Byaruhanga, Yusuf B; Muyanja, Charles M B K; Rudi, Knut; Langsrud, Thor; Narvhus, Judith A

2012-11-01

Obushera includes four fermented cereal beverages from Uganda namely: Obutoko, Enturire, Ekitiribita and Obuteire, whose microbial diversity has not hitherto been fully investigated. Knowledge of the microbial diversity and dynamics in these products is crucial for understanding their safety and development of appropriate starter cultures for controlled industrial processing. Culture-dependent and culture-independent techniques including denaturating gradient gel electrophoresis (DGGE) and mixed DNA sequencing of polymerase chain reaction (PCR) amplified ribosomal RNA genes were used to study the bacteria and yeast diversity of Obushera. The pH dropped from 6.0-4.6 to 3.5-4.0 within 1-2 days for Obutoko, Enturire and Obuteire whereas that of Ekitiribita decreased to 4.4 after 4 days. Counts of lactic acid bacteria (LAB) increased from 5.0 to 11.0 log cfug(-1) and yeasts increased from 3.4 to 7.1 log cfug(-1) while coliform counts decreased from 2.0 to <1 log cfug(-1) during four days of fermentation. LAB and yeast isolates were identified by rRNA gene sequence analysis. LAB isolates included: Enterococcus spp., Lactobacillus (Lb.) plantarum, Lb. fermentum, Lb. delbrueckii, Lactococcus lactis, Leuconostoc lactis, Streptococcus (S.) infantarius subsp. infantarius, Pediococcus pentosaceus and Weisella (W.) confusa. DGGE indicated predominance of S. gallolyticus, S. infantarius subsp. infantarius, Lb. fermentum, Lb. delbrueckii, W. confusa, Lb. reuteri, Fructobacillus spp., L. lactis and L. lactis. Yeast isolates included Clavispora lusitaniae, Cyberlindnera fabianii, Issatchenkia orientalis and Saccharomyces cerevisiae. DGGE indicated predominance of S. cerevisiae in Obutoko, Enturire and Obuteire and also detected Pichia spp. and I. orientalis in Obutoko. Obushera produced in the laboratory was initially dominated by Enterobacteriaceae and later by Lactococcus spp. Enterobacteriaceae and Bacillus spp. were also detected in Ekitiribita. Development of starters for

Inoculated fermentation of green olives with potential probiotic Lactobacillus pentosus and Lactobacillus plantarum starter cultures isolated from industrially fermented olives.

PubMed

Blana, Vasiliki A; Grounta, Athena; Tassou, Chrysoula C; Nychas, George-John E; Panagou, Efstathios Z

2014-04-01

The performance of two strains of lactic acid bacteria (LAB), namely Lactobacillus pentosus B281 and Lactobacillus plantarum B282, previously isolated from industrially fermented table olives and screened in vitro for probiotic potential, was investigated as starter cultures in Spanish style fermentation of cv. Halkidiki green olives. Fermentation was undertaken at room temperature in two different initial salt concentrations (8% and 10%, w/v, NaCl) in the brines. The strains were inoculated as single and combined cultures and the dynamics of their population on the surface of olives was monitored for a period of 114 days. The survival of inoculated strains on olives was determined using Pulsed Field Gel Electrophoresis (PFGE). Both probiotic strains successfully colonized the olive surface at populations ranged from 6.0 to 7.0 log CFU/g throughout fermentation. PFGE analysis revealed that L. pentosus B281 presented higher colonization in both salt levels at the end of fermentation (81.2% and 93.3% in 8% and 10% NaCl brines, respectively). For L. plantarum B282 a high survival rate (83.3%) was observed in 8% NaCl brines, but in 10% NaCl the strain could not colonize the surface of olives. L. pentosus B281 also dominated over L. plantarum B282 in inoculated fermentations when the two strains were used as combined culture. The biochemical profile (pH, organic acids, volatile compounds) attained during fermentation and the sensory analysis of the final product indicated a typical lactic acid fermentation process of green olives. Copyright © 2013 Elsevier Ltd. All rights reserved.

Evaluation of the use of malic acid decarboxylase-deficient starter culture in NaCl-free cucumber fermentations to reduce bloater incidence

USDA-ARS?s Scientific Manuscript database

AIMS: Accumulation of carbon dioxide in cucumber fermentations is known to cause hollow cavities inside whole fruits or bloaters, conducive to economic losses for the pickling industry. This study focused on evaluating the use of a malic acid decarboxylase (MDC)-deficient starter culture to minimiz...

Influence of oregano essential oil on traditional Argentinean cheese elaboration: Effect on lactic starter cultures.

PubMed

Marcial, Guillermo E; Gerez, Carla L; de Kairuz, Martha Nuñez; Araoz, Victoria Coll; Schuff, Carola; de Valdez, Graciela Font

The aim of this work is to study the oregano essential oil (OEO) composition from Northwestern Argentinean regions and to evaluate its effect on the lactic starter cultures. The oregano used, Origanum vulgare var hirtum, was obtained from Andalgalá, Catamarca. The essential oil presented high amounts of α-terpinene (10%), γ-terpinene (15.1%), terpinen-4-ol (15.5%) and thymol (13.0%) as the main components. No negative effect on growth or metabolic activity of lactic acid bacteria Streptococcus thermophilus CRL 728 and CRL 813, Lactobacillus delbrueckii subsp. bulgaricus CRL 656 and CRL 468, and Lactococcus lactis subsp. lactis CRL 597 up to the maximum concentration (200μg/g) assayed was observed. No differences in the organoleptic characteristics of semi-hard cheeses flavored with oregano essential oil (200μg/g) and homemade cheeses flavored with oregano leaves were found. With respect to the microbiological quality of the products, neither enterobacteria nor mold and yeast were detected during ripening in essential-oil flavored cheese compared to control cheese (enterobacteria 2×10 3 UFC/g) and cheese flavored with oregano leaves (mold/yeast 4×10 4 CFU/g). Our results showed that the use of oregano essential oil and lactic starter culture considerably improved cheese quality. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Monitoring of Leuconostoc mesenteroides DRC starter in fermented vegetable by random integration of chloramphenicol acetyltransferase gene.

PubMed

Eom, Hyun-Ju; Park, Joong Min; Seo, Min Jae; Kim, Myoung-Dong; Han, Nam Soo

2008-09-01

In 2004, Leuconostoc mesenteroides DRC was first used as a starter culture for achieving higher organoleptic effects in Korean kimchi manufacture. For a better understanding of starter growth in a mixed culture system, and for predicting starter predominance in kimchi, a monitoring system for the starter was established. The chloramphenicol resistance marker gene (cat) was randomly integrated into chromosomal DNA of L. mesenteroides DRC using a viral transposon and transposase. The DRC mutant, tDRC2, had a similar growth pattern to the host strain, with no major alteration in phenotypic characteristics. The mutant strain was inoculated into real kimchi, and monitoring of the starter population was successfully achieved. The overall predominance of Leuconostoc in kimchi inoculated with DRC followed the general growth pattern of this genus during kimchi fermentation. Our results also demonstrate the competitive ability of the DRC starter against Leuconostoc from natural flora, maintaining its predominance above 88% during the whole fermentation period. Based on this experiment, the random gene integration method using a transposon was shown to be of utility in transferring any commercial starter into a selectable and monitorable strain for simulation purposes.

Track Starter's Guide.

ERIC Educational Resources Information Center

Dailey, Charles H.; Rankin, Kelly D.

This guide was developed to serve both the novice and experienced starter in track and field events. Each year in the United States, runners encounter dozens of different starters' mannerisms as they travel to track meets in various towns and states. The goal of any competent and conscientious starter is to insure that all runners receive a fair…

Monitoring of staphylococcal starters in two French processing plants manufacturing dry fermented sausages.

PubMed

Corbiere Morot-Bizot, S; Leroy, S; Talon, R

2007-01-01

The growth and survival of Staphylococcus xylosus and Staphylococcus carnosus were monitored during sausage manufacture in two processing plants. The gram-positive, catalase-positive cocci isolated from the processing plants F10 and F11 were identified by Staphylococcus-specific PCR and species-specific oligonucleotide array. In the inoculated products with starter cultures, 90% of staphylococcal strains isolated in F10 were identified as S. xylosus and 10% as S. carnosus. In F11, 77% were identified as S. xylosus and 20% as S. carnosus. Staphylococcus xylosus dominated the staphylococcal microbiota while S. carnosus survived during the process. The pulse-field gel electrophoresis analysis revealed that all S. xylosus and S. carnosus strains isolated corresponded to the starter strains inoculated. The two starter strains of S. xylosus co-dominated in the isolates from sausages of F11, whereas the strain with pattern A1 was dominant in the isolates from sausages of F10. In the environments, no S. carnosus and S. xylosus were found, whereas Staphylococcus equorum and Staphylococcus saprophyticus were the main species isolated. This work highlighted the domination of S. xylosus starter strains, which showed a strong capacity to grow during sausage process, while S. carnosus survived during the process. Successful implantation of starter cultures is obviously a prerequisite for their contribution to sensorial qualities. Thus, the monitoring of the growth and the survival of S. xylosus and S. carnosus are required to guarantee a well-adapted starter culture. This study revealed that the two Staphylococcus species are suitable for manufacturing sausages in processing plants with very different capacities of production.

Beta-carotene-rich carotenoid-protein preparation and exopolysaccharide production by Rhodotorula rubra GED8 grown with a yogurt starter culture.

PubMed

Frengova, Ginka I; Simova, Emilina D; Beshkova, Dora M

2006-01-01

The underlying method for obtaining a beta-carotene-rich carotenoid-protein preparation and exopolysaccharides is the associated cultivation of the carotenoid-synthesizing lactose-negative yeast strain Rhodotorula rubra GED8 with the yogurt starter culture (Lactobacillus bulgaricus 2-11 + Streptococcus thermophilus 15HA) in whey ultrafiltrate (45 g lactose/l) with a maximum carotenoid yield of 13.37 mg/l culture fluid on the 4.5th day. The chemical composition of the carotenoid-protein preparation has been identified. The respective carotenoid and protein content is 497.4 microg/g dry cells and 50.3% per dry weight, respectively. An important characteristic of the carotenoid composition is the high percentage (51.1%) of beta-carotene (a carotenoid pigment with the highest provitamin A activity) as compared to 12.9% and 33.7%, respectively, for the other two individual pigments--torulene and torularhodin. Exopolysaccharides (12.8 g/l) synthesized by the yeast and lactic acid cultures, identified as acid biopolymers containing 7.2% glucuronic acid, were isolated in the cell-free supernatant. Mannose, produced exclusively by the yeast, predominated in the neutral carbohydrate biopolymer component (76%). The mixed cultivation of R. rubra GED8 with the yogurt starter (L. bulgaricus 2-11 + S. thermophilus 15HA) in ultrafiltrate under conditions of intracellular production of maximum amount of carotenoids and exopolysaccharides synthesis enables combined utilization of the culture fluid from the fermentation process.

Characterization of Active Dry Wine Yeast During Starter Culture (Pied de Cuve) Preparation for Sparkling Wine Production.

PubMed

Benucci, Ilaria; Liburdi, Katia; Cerreti, Martina; Esti, Marco

2016-08-01

The preparation of yeast starter culture (Pied de Cuve) for producing sparkling wine with the traditional method is a key factor for manufacturing a good Prise de mousse. In this paper, the evolution of total yeast population, its viability during Pied de Cuve preparation, and the pressure profile during the 2nd fermentation in 2 different base wines made from Bombino bianco and Chardonnay grapes were investigated using 4 different commercial active dried yeasts. The study proves that despite the initial differences observed throughout the acclimatization phase, all the tested strains showed similar results on either the total population (from 8.2 × 10(7) cells/mL to 1.3 × 10(8) cells/mL) or cellular viability (from 70% to 84%). Independently from the base wine tested, the kinetic of sugar consumption was faster during the gradual acclimatization to the alcoholic medium (phase II) and slower during the preparation of starter culture in active growth phase (phase III). During both of these phases Saccharomyces cerevisiae bayanus Vitilevure DV10(®) (Station œnotechnique de Champagne) proved to have a higher sugar consumption rate than the other strains. During the Prise de mousse, S. cerevisiae bayanus Lalvin EC-1118(®) (Lallemand) reached the maximum pressure increase within time in both base wines. © 2016 Institute of Food Technologists®

Production of wheat bread without preservatives using sourdough starters

PubMed Central

Denkova, Rositsa; Ilieva, Svetla; Denkova, Zapryana; Georgieva, Ljubka; Yordanova, Mariya; Nikolova, Dilyana; Evstatieva, Yana

2014-01-01

In order for the beneficial effects of sourdough application in breadmaking to take place a proper selection of lactic acid bacteria species and strains, an appropriate technology and effective control of the purity and activity of the selected cultures. Four symbiotic starters for sourdough for the production of bread were developed and probated in a production laboratory using the selected strains Lactobacillus brevis LBRZ7, L. buchneri LBRZ6, L. plantarum X2, L. paracasei RN5, L. sanfranciscensis R and L. fermentum LBRH10 and the probiotic strain Propionibacterium freudenreichii ssp. shermanii NBIMCC 327. The starter sourdoughs that include Propionibacterium freudenreichii ssp. shermanii NBIMCC 327 had greater antimicrobial activity against saprophytic microorganisms: Bacillus subtilis, B. mesentericus, Aspergillus niger, Penicillium sp. and Rhizopus sp., but none of them inhibited the growth of bakery yeasts Saccharomyces cerevisiae. It was established that in order to prevent bacterial spoilage 10% of the selected starter sourdoughs had to be added in the breadmaking process, while for prevention of mold spoilage the necessary amount of starter sourdough had to be between 15% and 20%.The application of the developed starters for the production of wheat bread guarantees longer shelf life and no adverse alterations in the features of the final bread. PMID:26019574

Lactobacillus sakei: A Starter for Sausage Fermentation, a Protective Culture for Meat Products

PubMed Central

Zagorec, Monique; Champomier-Vergès, Marie-Christine

2017-01-01

Among lactic acid bacteria of meat products, Lactobacillus sakei is certainly the most studied species due to its role in the fermentation of sausage and its prevalence during cold storage of raw meat products. Consequently, the physiology of this bacterium regarding functions involved in growth, survival, and metabolism during meat storage and processing are well known. This species exhibits a wide genomic diversity that can be observed when studying different strains and on which probably rely its multiple facets in meat products: starter, spoiler, or protective culture. The emerging exploration of the microbial ecology of meat products also revealed the multiplicity of bacterial interactions L. sakei has to face and their various consequences on microbial quality and safety at the end of storage. PMID:28878171

Selection of Lactobacillus plantarum strains to use as starters in fermented table olives: Oleuropeinase activity and phage sensitivity.

PubMed

Zago, Miriam; Lanza, Barbara; Rossetti, Lia; Muzzalupo, Innocenzo; Carminati, Domenico; Giraffa, Giorgio

2013-05-01

Fermented table olives (Olea europaea L.) are largely diffused in the Mediterranean area. Olives are picked at different stages of maturity and after harvesting, processed to eliminate the characteristic bitterness caused by the presence of the oleuropein glucoside and to become suitable for human consumption. The spontaneous fermentation of table olives mainly depends on lactic acid bacteria (LAB), and in particular on Lactobacillus plantarum which plays an important role in the degradation of oleuropein. The hydrolysis of oleuropein is attributed to the β-glucosidase and esterase activities of the indigenous LAB microflora. This study investigated the potential of L. plantarum strains isolated from dairy products and olives to be used as starters for fermented table olives. Forty-nine strains were typed by RAPD-PCR and investigated for the presence of the β-glucosidase (bglH) gene. The full sequence of the bglH gene was carried out. All the 49 L. plantarum strains were also tested for phage resistance. A total of six strains were selected on the basis of genotypic polymorphism, bglH gene sequence analysis, and phage resistance profile. These strains were further characterized to assess the acidifying capability, the growth at different temperatures, the tolerance to different NaCl concentrations, and the oleuropeinolytic activity. Although further characterizations are required, especially concerning the influence on sensory properties, L. plantarum proved to have the potential to be used as a debittering and fermentative agent in starter culture for fermented table olives. Copyright © 2012 Elsevier Ltd. All rights reserved.

Designing Inquiry Starters

NASA Astrophysics Data System (ADS)

Kluger-Bell, B.

2010-12-01

The term "Inquiry Starter" comes from the Institute for Inquiry's model for teaching and learning science through inquiry. It refers to the first phase of an inquiry activity where learners engage in actions that stimulate their curiosity and generate questions for further investigation. In the Professional Development Program, staff and participants have designed a wide variety of inquiry activities with a number of variations on the inquiry starter. This has provided a laboratory for examining inquiry starter design. In this paper, I describe and examine in detail the elements of this design and how the design of those elements is related to achieving learning objectives. There are a number of important common objectives in all inquiry starters. For example, all starters must define a domain for investigation and engage the learner's curiosity in that domain. There are also critical differences in learning objectives depending on the content area being studied, the learners' background knowledge and skills, and many other factors. In this paper I examine designs for both of these types of objectives.

Metagenomic Analysis of Dairy Bacteriophages: Extraction Method and Pilot Study on Whey Samples Derived from Using Undefined and Defined Mesophilic Starter Cultures.

PubMed

Muhammed, Musemma K; Kot, Witold; Neve, Horst; Mahony, Jennifer; Castro-Mejía, Josué L; Krych, Lukasz; Hansen, Lars H; Nielsen, Dennis S; Sørensen, Søren J; Heller, Knut J; van Sinderen, Douwe; Vogensen, Finn K

2017-10-01

Despite being potentially highly useful for characterizing the biodiversity of phages, metagenomic studies are currently not available for dairy bacteriophages, partly due to the lack of a standard procedure for phage extraction. We optimized an extraction method that allows the removal of the bulk protein from whey and milk samples with losses of less than 50% of spiked phages. The protocol was applied to extract phages from whey in order to test the notion that members of Lactococcus lactis 936 (now Sk1virus ), P335, c2 (now C2virus ) and Leuconostoc phage groups are the most frequently encountered in the dairy environment. The relative abundance and diversity of phages in eight and four whey mixtures from dairies using undefined mesophilic mixed-strain cultures containing Lactococcus lactis subsp. lactis biovar diacetylactis and Leuconostoc species (i.e., DL starter cultures) and defined cultures, respectively, were assessed. Results obtained from transmission electron microscopy and high-throughput sequence analyses revealed the dominance of Lc. lactis 936 phages (order Caudovirales , family Siphoviridae ) in dairies using undefined DL starter cultures and Lc. lactis c2 phages (order Caudovirales , family Siphoviridae ) in dairies using defined cultures. The 936 and Leuconostoc phages demonstrated limited diversity. Possible coinduction of temperate P335 prophages and satellite phages in one of the whey mixtures was also observed. IMPORTANCE The method optimized in this study could provide an important basis for understanding the dynamics of the phage community (abundance, development, diversity, evolution, etc.) in dairies with different sizes, locations, and production strategies. It may also enable the discovery of previously unknown phages, which is crucial for the development of rapid molecular biology-based methods for phage burden surveillance systems. The dominance of only a few phage groups in the dairy environment signifies the depth of knowledge

Metagenomic Analysis of Dairy Bacteriophages: Extraction Method and Pilot Study on Whey Samples Derived from Using Undefined and Defined Mesophilic Starter Cultures

PubMed Central

Muhammed, Musemma K.; Kot, Witold; Neve, Horst; Mahony, Jennifer; Castro-Mejía, Josué L.; Krych, Lukasz; Hansen, Lars H.; Nielsen, Dennis S.; Sørensen, Søren J.; Heller, Knut J.; van Sinderen, Douwe

2017-01-01

ABSTRACT Despite being potentially highly useful for characterizing the biodiversity of phages, metagenomic studies are currently not available for dairy bacteriophages, partly due to the lack of a standard procedure for phage extraction. We optimized an extraction method that allows the removal of the bulk protein from whey and milk samples with losses of less than 50% of spiked phages. The protocol was applied to extract phages from whey in order to test the notion that members of Lactococcus lactis 936 (now Sk1virus), P335, c2 (now C2virus) and Leuconostoc phage groups are the most frequently encountered in the dairy environment. The relative abundance and diversity of phages in eight and four whey mixtures from dairies using undefined mesophilic mixed-strain cultures containing Lactococcus lactis subsp. lactis biovar diacetylactis and Leuconostoc species (i.e., DL starter cultures) and defined cultures, respectively, were assessed. Results obtained from transmission electron microscopy and high-throughput sequence analyses revealed the dominance of Lc. lactis 936 phages (order Caudovirales, family Siphoviridae) in dairies using undefined DL starter cultures and Lc. lactis c2 phages (order Caudovirales, family Siphoviridae) in dairies using defined cultures. The 936 and Leuconostoc phages demonstrated limited diversity. Possible coinduction of temperate P335 prophages and satellite phages in one of the whey mixtures was also observed. IMPORTANCE The method optimized in this study could provide an important basis for understanding the dynamics of the phage community (abundance, development, diversity, evolution, etc.) in dairies with different sizes, locations, and production strategies. It may also enable the discovery of previously unknown phages, which is crucial for the development of rapid molecular biology-based methods for phage burden surveillance systems. The dominance of only a few phage groups in the dairy environment signifies the depth of knowledge

Influence of starters on chemical, biochemical, and sensory changes in Turkish White-brined cheese during ripening.

PubMed

Hayaloglu, A A; Guven, M; Fox, P F; McSweeney, P L H

2005-10-01

Turkish White-brined cheese was manufactured using Lactococcus strains (Lactococcus lactis ssp. lactis NCDO763 plus L. lactis ssp. cremoris SK11 and L. lactis ssp. lactis UC317 plus L. lactis ssp. cremoris HP) or without a starter culture, and ripened for 90 d. It was found that the use of starters significantly influenced the physical, chemical, biochemical, and sensory properties of the cheeses. Chemical composition, pH, and sensory properties of cheeses made with starter were not affected by the different starter bacteria. The levels of soluble nitrogen fractions and urea-PAGE of the pH 4.6-insoluble fractions were found to be significantly different at various stages of ripening. Urea-PAGE patterns of the pH 4.6-insoluble fractions of the cheeses showed that considerable degradation of alpha(s1)-casein occurred and that beta-casein was more resistant to hydrolysis. The use of a starter culture significantly influenced the levels of 12% trichloroacetic acid-soluble nitrogen, 5% phosphotungstic acid-soluble nitrogen, free amino acids, total free fatty acids, and the peptide profiles (reverse phase-HPLC) of 70% (vol/vol) ethanol-soluble and insoluble fractions of the pH 4.6-soluble fraction of the cheeses. The levels of peptides in the cheeses increased during the ripening period. Principal component and hierarchical cluster analyses of electrophoretic and chromatographic results indicated that the cheeses were significantly different in terms of their peptide profiles and they were grouped based on the use and type of starter and stage of ripening. Levels of free amino acid in the cheeses differed; Leu, Glu, Phe, Lys, and Val were the most abundant amino acids. Nitrogen fractions, total free amino acids, total free fatty acids, and the levels of peptides resolved by reverse phase-HPLC increased during ripening. No significant differences were found between the sensory properties of cheeses made using a starter, but the cheese made without starter received lower

Proteolytic and ACE-inhibitory activities of probiotic yogurt containing non-viable bacteria as affected by different levels of fat, inulin and starter culture.

PubMed

Shakerian, Mansour; Razavi, Seyed Hadi; Ziai, Seyed Ali; Khodaiyan, Faramarz; Yarmand, Mohammad Saeid; Moayedi, Ali

2015-04-01

In this study, the effects of fat (0.5 %, 3.2 % and 5.0 %), inulin (0.0 and 1.0 %) and starter culture (0.0 %, 0.5 %, 1.0 % and 1.5 %) on the angiotensin converting enzyme (ACE)-inhibitory activity of probiotic yogurt containing non-viable bacteria were assessed. Proteolytic activities of bacteria were also investigated. Yogurts were prepared either using a sole yogurt commercial culture including Streptococcus thermophilus and Lactobacillus delbrueckii subs. bulgaricus or bifidobacterium animalis BB-12 and Lactobacillus acidophilus La5 in addition to yogurt culture. Relative degrees of proteolysis were found to be considerably higher in yogurt samples than UHT milk as the control. Both regular and probiotic yogurts showed considerable ACE-inhibitory activities. Results showed that degree of proteolysis was not influenced by different fat contents, while was increased by high concentration of starter culture (1.5 % w/w) and reduced by inulin (1 % w/w). ACE-inhibitory activities of yogurt were also negatively affected by the presence of inulin and high levels of fat (5 % w/w). Moreover, yogurt containing probiotic bacteria showed higher inhibitory against ACE in comparison to the yogurt prepared with non-probiotic strains.

Brettanomyces as a starter culture in rice-steamed sponge cake: a traditional fermented food in China.

PubMed

Wu, Peng; Xu, Xiaoyun; Xu, Yongxia; Chen, Qingchan; Pan, Siyi

2011-11-01

The potential use of Brettanomyces anomalus PSY-001 as an additional starter culture for the production of Rice-steamed sponge cake (RSSC), a traditional fermented food in China, was investigated. Two productions of RSSC, each containing batches of experimental cakes with Brettanomyces added and reference cakes with the leavened liquid added were carried out. For both experimental and reference cakes, chemical analysis and sensory evaluation were carried out during the fermentation period. The results showed that experimental cakes had desirable aroma and taste. The observed differences indicate a positive contribution to the overall quality of RSSC by B. anomalus PSY-001.

Reflections on Three Corporate Research Labs: Bell Labs, HP Labs, Agilent Labs

NASA Astrophysics Data System (ADS)

Hollenhorst, James

2008-03-01

This will be a personal reflection on corporate life and physics-based research in three industrial research labs over three decades, Bell Labs during the 1980's, HP Labs during the 1990's, and Agilent Labs during the 2000's. These were times of great change in all three companies. I'll point out some of the similarities and differences in corporate cultures and how this impacted the research and development activities. Along the way I'll mention some of the great products that resulted from physics-based R&D.

Invited review: Microbial evolution in raw-milk, long-ripened cheeses produced using undefined natural whey starters.

PubMed

Gatti, Monica; Bottari, Benedetta; Lazzi, Camilla; Neviani, Erasmo; Mucchetti, Germano

2014-02-01

The robustness of the starter culture during cheese fermentation is enhanced by the presence of a rich consortium of microbes. Natural starters are consortia of microbes undoubtedly richer than selected starters. Among natural starters, natural whey starters (NWS) are the most common cultures currently used to produce different varieties of cheeses. Undefined NWS are typically used for Italian cooked, long-ripened, extra-hard, raw milk cheeses, such as Parmigiano Reggiano and Grana Padano. Together with raw milk microbiota, NWS are responsible for most cheese characteristics. The microbial ecology of these 2 cheese varieties is based on a complex interaction among starter lactic acid bacteria (SLAB) and nonstarter lactic acid bacteria (NSLAB), which are characterized by their different abilities to grow in a changing substrate. This review aims to summarize the latest findings on Parmigiano Reggiano and Grana Padano to better understand the dynamics of SLAB, which mainly arise from NWS, and NSLAB, which mainly arise from raw milk, and their possible role in determining the characteristics of these cheeses. The review is presented in 4 main sections. The first summarizes the main microbiological and chemical properties of the ripened cheese as determined by cheese-making process variables, as these variables may affect microbial growth. The second describes the microbiota of raw milk as affected by specific milk treatments, from milking to the filling of the cheese milk vat. The third describes the microbiota of NWS, and the fourth reviews the knowledge available on microbial dynamics from curd to ripened cheese. As the dynamics and functionality of complex undefined NWS is one of the most important areas of focus in current food microbiology research, this review may serve as a good starting point for implementing future studies on microbial diversity and functionality of undefined cheese starter cultures. Copyright © 2014 American Dairy Science Association

Effect of starters and ripening time on the physicochemical, nitrogen fraction and texture profile of goat's cheese coagulated with a vegetable coagulant (Cynara cardunculus).

PubMed

García, Víctor; Rovira, Silvia; Boutoial, Khalid; Ferrandini, Eduardo; López Morales, María B

2014-02-01

The increase in the demand for goat's cheese throughout the world has encouraged research into the development of new related products with different textural characteristics. The aim of this work was to study the effect of three commercial starter cultures through the assessment of physicochemical and textural characteristics of goat's milk cheeses made with vegetable coagulant (Cynara cardunculus) during ripening. Use of the different starter cultures produced a significant effect (P < 0.05) on moisture, proteins, pH, nitrogen fractions and hardness of the cheeses. Results show that the addition of mesophilic starters ensures the correct acidification rate and produced cheeses with lower pH values and greater hardness. Use of thermophilic starter cultures produces cheeses with less instrumental hardness and the use of mixed cultures produced less proteolysis. These results are found useful for selecting the most suitable starter for the development of new goat's cheeses. © 2013 Society of Chemical Industry.

Biodiversity of Lactobacillus helveticus bacteriophages isolated from cheese whey starters.

PubMed

Zago, Miriam; Bonvini, Barbara; Rossetti, Lia; Meucci, Aurora; Giraffa, Giorgio; Carminati, Domenico

2015-05-01

Twenty-one Lactobacillus helveticus bacteriophages, 18 isolated from different cheese whey starters and three from CNRZ collection, were phenotypically and genetically characterised. A biodiversity between phages was evidenced both by host range and molecular (RAPD-PCR) typing. A more detailed characterisation of six phages showed similar structural protein profiles and a relevant genetic biodiversity, as shown by restriction enzyme analysis of total DNA. Latent period, burst time and burst size data evidenced that phages were active and virulent. Overall, data highlighted the biodiversity of Lb. helveticus phages isolated from cheese whey starters, which were confirmed to be one of the most common phage contamination source in dairy factories. More research is required to further unravel the ecological role of Lb. helveticus phages and to evaluate their impact on the dairy fermentation processes where whey starter cultures are used.

A peptidomic approach of meat protein degradation in a low-sodium fermented sausage model using autochthonous starter cultures.

PubMed

de Almeida, Marcio Aurélio; Saldaña, Erick; da Silva Pinto, Jair Sebastião; Palacios, Jorge; Contreras-Castillo, Carmen J; Sentandreu, Miguel Angel; Fadda, Silvina Graciela

2018-07-01

Fermented sausage technology is currently compromised in decreasing the addition of NaCl. Use of starter cultures with peptidogenic potential could be a valuable strategy that can mask or hide off flavors produced by the use of NaCl substituents. In the present work, the peptidogenic potential of four lactic acid bacteria species was evaluated in a low-sodium beaker sausage (BS) model. Using a peptidomic approach, a total of 86 low molecular weight (LMW) peptides were accurately identified, mostly derived from myofibrillar proteins, especially actin, which generated 53 peptides. The BS inoculated with L. curvatus CRL705 generated 56 LMW peptides, followed by Enterococcus (E.) mundtii CRL35 with 43 peptides. In addition, BS inoculated with Lactobacillus (L.) plantarum and with L. sakei produced higher amino acid amounts over time as compared to the rest of BS models, highlighting the importance of both, time and sample effect on the overall free amino acid generation. The presence of each LAB strain in BS models generated a unique profile of small peptides and amino acids that could serve as a distinctive biochemical trait to differentiate specific fermented products. According to these results, E. mundtii and L. sakei, which are compatible between them, are proposed as the most efficiently adapted to low-sodium conditions. The use of selected strains during the processing of low-sodium fermented sausages could have a positive effect on the production of small peptides and free amino acids. Copyright © 2018 Elsevier Ltd. All rights reserved.

Selection of lactic acid bacteria from Brazilian kefir grains for potential use as starter or probiotic cultures.

PubMed

Zanirati, Débora Ferreira; Abatemarco, Mário; Sandes, Sávio Henrique de Cicco; Nicoli, Jacques Robert; Nunes, Álvaro Cantini; Neumann, Elisabeth

2015-04-01

Brazilian kefir is a homemade fermented beverage that is obtained by incubating milk or a brown sugar solution with kefir grains that contribute their different microbiological compositions. It is highly important to isolate and characterize microorganisms from Brazilian kefir grains to obtain starter cultures for the industrial production of a standardized commercial kefir. Thus, the present study aimed to isolate lactic acid bacteria from eight kefir grains that were propagated in milk or sugar solutions from five different locations in Brazil and to select Lactobacillus isolates based on desirable in vitro probiotic properties. One hundred eight isolates from both substrates were identified by amplified ribosomal DNA restriction analysis and/or 16S rRNA gene sequencing and were determined to belong to the following 11 species from the genera: Lactococcus, Leuconostoc, Lactobacillus (L.), and Oenococcus. Leuconostoc mesenteroides, Lactobacillus kefiri, and Lactobacillus kefiranofaciens were isolated only from milk grains, whereas Lactobacillus perolens, Lactobacillus parafarraginis, Lactobacillus diolivorans, and Oenococcus oeni were isolated exclusively from sugar water grains. When the microbial compositions of four kefir grains were evaluated with culture-independent analyses, L. kefiranofaciens was observed to predominant in milk grains, whereas Lactobacillus hilgardii was most abundant in sugar water kefir. Unfortunately, L. hilgardii was not isolated from any grain, although this bacteria was detected with a culture-independent methodology. Fifty-two isolated Lactobacilli were tested for gastric juice and bile salt tolerance, antagonism against pathogens, antimicrobial resistance, and surface hydrophobicity. Three Lactobacillus strains (L. kefiranofaciens 8U, L. diolivorans 1Z, and Lactobacillus casei 17U) could be classified as potential probiotics. In conclusion, several lactic acid bacteria that could be used in combination with yeasts as starter

Comparative genome analysis of the candidate functional starter culture strains Lactobacillus fermentum 222 and Lactobacillus plantarum 80 for controlled cocoa bean fermentation processes.

PubMed

Illeghems, Koen; De Vuyst, Luc; Weckx, Stefan

2015-10-12

Lactobacillus fermentum 222 and Lactobacillus plantarum 80, isolates from a spontaneous Ghanaian cocoa bean fermentation process, proved to be interesting functional starter culture strains for cocoa bean fermentations. Lactobacillus fermentum 222 is a thermotolerant strain, able to dominate the fermentation process, thereby converting citrate and producing mannitol. Lactobacillus plantarum 80 is an acid-tolerant and facultative heterofermentative strain that is competitive during cocoa bean fermentation processes. In this study, whole-genome sequencing and comparative genome analysis was used to investigate the mechanisms of these strains to dominate the cocoa bean fermentation process. Through functional annotation and analysis of the high-coverage contigs obtained through 454 pyrosequencing, plantaricin production was predicted for L. plantarum 80. For L. fermentum 222, genes encoding a complete arginine deiminase pathway were attributed. Further, in-depth functional analysis revealed the capacities of these strains associated with carbohydrate and amino acid metabolism, such as the ability to use alternative external electron acceptors, the presence of an extended pyruvate metabolism, and the occurrence of several amino acid conversion pathways. A comparative genome sequence analysis using publicly available genome sequences of strains of the species L. plantarum and L. fermentum revealed unique features of both strains studied. Indeed, L. fermentum 222 possessed genes encoding additional citrate transporters and enzymes involved in amino acid conversions, whereas L. plantarum 80 is the only member of this species that harboured a gene cluster involved in uptake and consumption of fructose and/or sorbose. In-depth genome sequence analysis of the candidate functional starter culture strains L. fermentum 222 and L. plantarum 80 revealed their metabolic capacities, niche adaptations and functionalities that enable them to dominate the cocoa bean fermentation

Effect of starter culture, spice mix and storage time and temperature on biogenic amine content of dry fermented sausages.

PubMed

Komprda, T; Smělá, D; Pechová, P; Kalhotka, L; Stencl, J; Klejdus, B

2004-08-01

Two types of dry fermented sausage differing in spicing mixture and the diameter (low content of red pepper+diameter 80 mm, H-sausage; high content of red pepper+diameter 55 mm, P-sausage, respectively) were produced in parallel with two different starter cultures (Pediococcus pentosaceus+Staphylococcus carnosus, B-samples and S. carnosus+Staphylococcus xylosus+Lactobacillus farciminis, F-samples, respectively). The sausages were ripened 21 days and subsequently stored 91 days at the room temperature. Concentration of both most abundant amines, putrescine and tyramine (y; mg/kg DM) increased significantly (P<0.01) in HB-sausage during ripening (x; days): y=2.5+18.13x-0.3144x(2) (R(2)=0.99) and y=0.7+8.17x-0.1130x(2) (R(2)=0.99), and also during storage: y=127.3+5.123x (R(2)=0.79) and y=26.0+3.211x (R(2)=0.74), respectively. At the end of ripening, putrescine (247 mg/kg DM) and tyramine (123 mg/kg DM) content in the HB-sausage was higher (P<0.05) than in the PB-sausage (12 and 9 mg/kg DM, respectively), concentration of either of these amines was negligible (1 mg/kg DM) in either type of F-inoculated sausage. Both starter culture and sausage type influenced significantly (P<0.001) both putrescine and tyramine content in the sausage; starter accounted for 57% and 55% of total variability in putrescine and tyramine content, respectively. Due to the significant (P<0.05) increase of total aerobic counts in the HB-sausage between the end of ripening and the 7th day of storage, followed by the significant (P<0.01) increase of the sum of total biogenic amines between the end of ripening (425 mg/kg DM) and the end of storage (1029 mg/kg DM), the storage of the dry fermented sausages at the room temperature should not be recommended.

Use of lacticin 481 to facilitate delivery of the bacteriophage resistance plasmid, pCBG104 to cheese starters.

PubMed

Mills, S; Coffey, A; O'Sullivan, L; Stokes, D; Hill, C; Fitzgerald, G F; Ross, R P

2002-01-01

Use of lacticin 481 to facilitate the conjugal transfer of the bacteriophage resistance plasmid pCBG104 to various starter cultures. A raw milk isolate of Lactococcus was found to harbour determinants for lacticin 481 production and immunity and phage resistance on a plasmid designated pCBG104. The lacticin 481 was successfully used to mobilize the phage resistance determinant to a variety of cheese starters enabling the formation of highly phage resistant starters. In addition, it facilitated the stacking of a number of phage resistance genes, namely a type I restriction modification system, a phage abortive infection system and a phage adsorption blocking system in a single Lactococcus strain without the use of recombinant techniques. The transconjugants were all shown to produce lacticin 481 and to contain the entire 481 operon. Subsequently one transconjugant was selected and successfully used for large-scale cheddar cheese manufacture. Lacticin 481 could be used as a food-grade selectable marker to facilitate the introduction of advantageous traits to starter cultures for industrial food fermentations. Food-grade selectable markers greatly facilitate the introduction of various advantageous traits to starter cultures for industrial food fermentation. Indeed self-cloning which is becoming increasingly important for strain improvement has a requirement for the identification and demonstration of the utility of tools such as lacticin 481.

Examination of the technological properties of newly isolated strains of the genus Lactobacillus and possibilities for their application in the composition of starters.

PubMed

Denkova, Rositsa; Ilieva, Svetla; Denkova, Zapryana; Georgieva, Ljubka; Krastanov, Albert

2014-05-04

The ability of four Lactobacillus strains - Lactobacillus brevis LBRZ7 (isolated from fermented cabbage), Lactobacillus plantarum LBRZ12 (isolated from fermented cabbage), Lactobacillus fermentum LBRH9 (of human origin) and Lactobacillus casei ssp. rhamnosus LBRC11 (isolated from home-made cheese) - to grow in flour/water environment and to accumulate high concentrations of viable cells was examined. Two starters for sourdough were created for lab-scale production of wheat bread: a two-strain starter and a four-strain starter. Wheat bread with improved properties - greater loaf volume, enhanced flavour and softer and brighter crumb - was obtained from the 7% four-strain starter sourdough. The addition of sourdough in the production of wheat bread affected positively the technological and organoleptic characteristics of the final bread by inhibiting the growth of wild yeasts and mold and Bacillus spores without the addition of preservatives. The inclusion of 15% of the four-strain starter sourdough in the bread-making process led to enhanced safety and longer shelf life of the baked bread.

Effect of varying the salt and fat content in Cheddar cheese on aspects of the performance of a commercial starter culture preparation during ripening.

PubMed

Yanachkina, Palina; McCarthy, Catherine; Guinee, Tim; Wilkinson, Martin

2016-05-02

Production of healthier reduced-fat and reduced-salt cheeses requires careful selection of starter bacteria, as any substantial alterations to cheese composition may prompt changes in the overall performance of starters during cheese ripening. Therefore, it is important to assess the effect of compositional alterations on the individual strain response during cheese ripening for each optimised cheese matrix. In the current study, the effect of varying fat and salt levels in Cheddar cheese on the performance of a commercial Lactococcus lactis culture preparation, containing one L. lactis subsp. lactis strain and one L. lactis subsp. cremoris strain was investigated. Compositional variations in fat or salt levels did not affect overall starter viability, yet reduction of fat by 50% significantly delayed non-starter lactic acid bacteria (NSLAB) populations at the initial ripening period. In comparison to starter viability, starter autolysis, as measured by release of intracellular lactate dehydrogenase (LDH) or post-proline dipeptidyl aminopeptidase (Pep X) into cheese juices, decreased significantly with lower salt addition levels in full-fat Cheddar. Conversely, reducing fat content of cheese resulted in a significantly higher release of intracellular Pep X, and to a lesser extent intracellular LDH, into juices over ripening. Flow cytometry (FCM) indicated that the permeabilised and dead cell sub-populations were generally lower in juices from cheeses with reduced salt content, however no significant differences were observed between different salt and fat treatments. Interestingly, fat reductions by 30 and 50% in cheeses with reduced or half added salt contents appeared to balance out the effect of salt, and enhanced cell permeabilisation, cell death, and also cell autolysis in these variants. Overall, this study has highlighted that alterations in both salt and fat levels in cheese influence certain aspects of starter performance during ripening, including

Chemical, Physiochemical, and Microstructural Properties, and Probiotic Survivability of Fermented Goat Milk Using Polymerized Whey Protein and Starter Culture Kefir Mild 01.

PubMed

Wang, Hao; Wang, Cuina; Wang, Mu; Guo, Mingruo

2017-11-01

A set-type fermented goat milk (FGM) using polymerized whey protein (PWP) as main thickening agent and Kefir Mild 01 as starter culture was developed. The FGM with PWP (0.3%, w/v) and pectin (0.2%, w/v) had low syneresis (5.44 ± 0.92%), desirable viscosity (952.86 ± 61.52 mPa⋅s), and hardness (112.57 ± 3.23 g), which were comparable to a fermented cow milk. Sensory evaluation data showed that the FGM with PWP and pectin had higher scores of both flavor (4.41 ± 0.39) and taste (3.72 ± 0.34) than the sample without PWP. Chemical composition of both fermented goat and cow milk were analyzed. The protein content of goat and cow milk samples were 3.50% ± 0.12% and 3.28% ± 0.09% (w/w), respectively. Lactobacillus acidophilus population in both FGM samples remained above 10 6 CFU/g during the 1st 4-wk storage. There was a slight but no significant (P > 0.05) decrease in pH and TA during storage. Scanning electron microscopy micrographs displayed a compact and homogeneous protein network of the FGM with PWP and pectin. Polymerized whey protein may be a novel protein-based thickening agent for formulation of a set-type FGM with starter culture Kefir Mild 01. Fermented goat milk is an increasingly popular dairy product in the world. However, it is difficult to make set type fermented goat milk due to the smaller size and lower content of casein micelles in goat milk. A fermented goat milk with PWP (0.3%, w/v) and pectin (0.2%, w/v) was successfully developed in this study. The product fermented by Kefir Mild 01 starter culture had a similar taste with Kefir but no yeast or alcoholic exists. The new product would be a promising food in the market. © 2017 Institute of Food Technologists®.

The evaluation of kefir pure culture starter: Liquid-core capsule entrapping microorganisms isolated from kefir grains.

PubMed

Wang, Liang; Zhong, Hao; Liu, Keying; Guo, Aizhen; Qi, Xianghui; Cai, Meihong

2016-10-01

The main purpose of this study was to develop a pure culture starter for producing kefir. In order to accomplish starter recycling, yeasts (Kluyveromyces marxianus strain, Pichia kudriavzevii clone), lactic acid bacteria (Lactobacillus kefiri strain F4Aa, Lactobacillus kefiri strain NM131-7, Lactobacillus kefiri strain NM132-3, Lactobacillus kefiri strain NM180-3, respectively), and acetic acid bacteria (Acetobacter lovaniensis strain) were entrapped in liquid core capsules based on the distribution ratio in kefir grains. The microbiological, antimicrobial, and chemical properties of kefir made with capsules (M) and kefir grains (K) were measured and compared. According to the results of plate counts in different selective medium, the number of yeasts and bacteria in the liquid core capsules gradually increased and stabilized after eight fermentation cycles. The results of gas chromatography-mass spectrometry showed that almost all the aroma components existed in the two type of kefir, except the ethyl lactate. There was no significant difference in alcohol content, protein content, and fat content, except the acidity and sugar content. Water holding capacity of kefir K was higher than kefir M. There were 14 same free amino acids in kefir M and kefir K, and the content of most free amino acids was similar. In antimicrobial test, there was no significant difference in both kefirs. © The Author(s) 2016.

Penicillium salamii strain ITEM 15302: A new promising fungal starter for salami production.

PubMed

Magistà, D; Ferrara, M; Del Nobile, M A; Gammariello, D; Conte, A; Perrone, G

2016-08-16

Traditional sausages are often considered of superior quality to sausages inoculated with commercial starter cultures and this is partially due to the action of the typical house microflora. Penicillium nalgiovense is the species commonly used as starter culture for dry-cured meat production. Recently a new species, Penicillium salamii, was described as typical colonizer during salami seasoning. In order to understand its contribution to the seasoning process, two different experiments on curing of fresh pork sausages were conducted using P. salamii ITEM 15302 in comparison with P. nalgiovense ITEM 15292 at small and industrial scale, and the dry-cured sausages were subjected to sensory analyses. Additionally, proteolytic and lipolytic in vitro assays were performed on both strains. P. salamii ITEM 15302 proved to be a fast growing mould on dry-cured sausage casings, well adapted to the seasoning process, with high lipolytic and proteolytic enzymatic activity that confers typical sensory characteristics to meat products. Therefore, P. salamii ITEM 15302 was shown to be a good candidate as new starter for meat industry. Copyright © 2015 Elsevier B.V. All rights reserved.

7 CFR 58.406 - Starter facility.

Code of Federal Regulations, 2010 CFR

2010-01-01

... precaution shall be taken to prevent contamination of the facility, equipment and the air therein. A filtered air supply with a minimum average efficiency of 90 percent when tested in accordance with the ASHRAE....406 Starter facility. A separate starter room or properly designed starter tanks and satisfactory air...

Biogenic amine content in dry fermented sausages as influenced by a producer, spice mix, starter culture, sausage diameter and time of ripening.

PubMed

Komprda, T; Sládková, P; Dohnal, V

2009-11-01

Sixteen types of dry fermented sausages were commercially produced as combinations of two producers (designated K and R), two starter cultures (Pediococcus pentosaceus, C; Lactobacillus curvatus+Staphylococcus carnosus, F), two spicing mixtures (H; P) and two casing diameters (4.5cm, T; 7cm, W), and were sampled at days zero, 14, 28 (end of ripening), 49, 70, 91 and 112 (samples were stored at 15°C and relative humidity of 70% between days 28 and 112). Tyramine and putrescine content (Y, mgkg(-1)) increased (P<0.01) with increasing time of ripening/storage (X, days): Y=52.0+5.19X-0.0275X(2) (R(2)=0.60) and Y=37.0+3.45X-0.0192X(2) (R(2)=0.23), respectively. Smaller diameter (T), spice mix containing red pepper (P) and starter culture C decreased (P<0.05) both tyramine and putrescine content in the sausages as compared to the W, H and F counterparts, respectively; content of both amines was lower (P<0.05) in the K-sausages than in the R-sausages. Tyramine content in the sausages at the time interval 28days of ripening+21days of storage was in the range from 170 (KHCU sausage combination) to 382 (RHFS) mgkg(-1).

Using Learning Labs for Culturally Responsive Positive Behavioral Interventions and Supports

ERIC Educational Resources Information Center

Bal, Aydin; Schrader, Elizabeth M.; Afacan, Kemal; Mawene, Dian

2016-01-01

Culturally responsive positive behavioral interventions and supports (CRPBIS) is a statewide research project designed to renovate behavioral support systems to become more inclusive, adaptive, and supportive for all. The CRPBIS methodology, called "learning lab," provides a research-based process to bring together local stakeholders and…

[The microflora of sour dough. IV. Communication: bacterial composition of sourdough starters genus Lactobacillus beijerinck (author's transl)].

PubMed

Spicher, G; Schröder, R

1978-11-28

The bacterial composition of three so called pure culture sourdough starters of varying origin was investigated. 245 isolates were obtained all belonging to the genus Beijerinck. According to their morphological, physiological and biochemical characteristics they were classified into the subgroups: Thermobacterium (L. acidophilus), Streptobacterium (L. casei, L. plantarum, L. farciminis, L. alimentarius) and Betabacterium (L. brevis, L. brevis var. lindneri, L buchneri, L. fermentum, L. fructi vorans). In the three sourdough starters the identified lactic organisms varied in number and proportion. In starter preparation "A" only the varieties L. fructi vorans and L. fermentum were present. Preparation "B" contained a great variety of microorganisms with L. brevis and L. brevis L. lindneri predominating. In starter "C" L. brevis, L. plantarum and L. alimentarius predominated.

Protection by fungal starters against growth and secondary metabolite production of fungal spoilers of cheese.

PubMed

Nielsen, M S; Frisvad, J C; Nielsen, P V

1998-06-30

The influence of fungal starter cultures on growth and secondary metabolite production of fungal contaminants associated with cheese was studied on laboratory media and Camembert cheese. Isolates of the species Penicillium nalgiovense, P. camemberti, P. roqueforti and Geotrichum candidum were used as fungal starters. The species P. commune, P. caseifulvum, P. verrucosum, P. discolor, P. solitum, P. coprophilum and Aspergillus versicolor were selected as contaminants. The fungal starters showed different competitive ability on laboratory media and Camembert cheese. The presence of the Penicillium species, especially P. nalgiovense, showed an inhibitory effect on the growth of the fungal contaminants on laboratory media. G. candidum caused a significant inhibition of the fungal contaminants on Camembert cheese. The results indicate that G. candidum plays an important role in competition with undesirable microorganisms in mould fermented cheeses. Among the starters, P. nalgiovense caused the largest reduction in secondary metabolite production of the fungal contaminants on the laboratory medium. On Camembert cheese no significant changes in metabolite production of the fungal contaminants was observed in the presence of the starters.

Autochthonous fermentation starters for the industrial production of Negroamaro wines.

PubMed

Tristezza, Mariana; Vetrano, Cosimo; Bleve, Gianluca; Grieco, Francesco; Tufariello, Maria; Quarta, Angela; Mita, Giovanni; Spano, Giuseppe; Grieco, Francesco

2012-01-01

The aim of the present study was to establish a new procedure for the oenological selection of Saccharomyces cerevisiae strains isolated from natural must fermentations of an important Italian grape cultivar, denoted as "Negroamaro". For this purpose, 108 S. cerevisiae strains were selected as they did not produce H(2)S and then assayed by microfermentation tests. The adopted procedure made it possible to identify 10 strains that were low producers of acetic acid and hydrogen sulphide and showed that they completed sugar consumption during fermentation. These strains were characterized for their specific oenological and technological properties and, two of them, strains 6993 and 6920, are good candidates as industrial starter cultures. A novel protocol was set up for their biomass production and they were employed for industrial-scale fermentation in two industrial cellars. The two strains successfully dominated the fermentation process and contributed to increasing the wines' organoleptic quality. The proposed procedure could be very effective for selecting "company-specific" yeast strains, ideal for the production of typical regional wines. "Winery" starter cultures could be produced on request in a small plant just before or during the vintage season and distributed as a fresh liquid concentrate culture.

Comparison of Bacterial Diversity Between Two Traditional Starters and the Round-Koji-Maker Starter for Traditional Cantonese Chi-Flavor Liquor Brewing

PubMed Central

Wang, Jie; Zhong, Qingping; Yang, Yingying; Li, Hanrong; Wang, Li; Tong, Yigang; Fang, Xiang; Liao, Zhenlin

2018-01-01

Xiaoqu is a traditional fermentation starter that is used for Chinese liquor production. Although microorganisms in the starters are closely associated with the quality and flavor of liquor, knowledge of the microbiota in xiaoqu is still far from complete, let alone the starters produced by new processes. Here, Illumina MiSeq high-throughput sequencing was applied to study bacterial composition in three types of xiaoqu used in Cantonese soybean-flavor (Chi-flavor) liquor, namely two traditional starters (Jiu Bing and Bing Wan) and a Round-Koji-maker starter (San qu) produced by the automatic starter-making disk machine. The results showed bacterial diversity in traditional starters was similar and higher than that in the Round-Koji-maker starter. Lactobacillus and Pediococcus were the dominant genera in all starters, while other different dominant genera also existed in different starters, which were Weissella, Acetobacter, and Gluconobacter for Jiu Bing, Weissella for Bing Wan, and Bacillus, Acetobacter, Acinetobacter and Klebsiella for San qu, respectively. Meanwhile, Cytophagaceae, one particular microbial family, and some pathogens including Klebsiella, Cronobacter, and Enterobacter were also found in San qu, indicating the automatic starter-making disk machine should be ameliorated before applied into industrial production. These results enriched our knowledge on xiaoqu-related microorganisms and might be helpful in industrial Chi-flavor liquor production and the development of fermentation technology. PMID:29875758

Comparison of Bacterial Diversity Between Two Traditional Starters and the Round-Koji-Maker Starter for Traditional Cantonese Chi-Flavor Liquor Brewing.

PubMed

Wang, Jie; Zhong, Qingping; Yang, Yingying; Li, Hanrong; Wang, Li; Tong, Yigang; Fang, Xiang; Liao, Zhenlin

2018-01-01

Xiaoqu is a traditional fermentation starter that is used for Chinese liquor production. Although microorganisms in the starters are closely associated with the quality and flavor of liquor, knowledge of the microbiota in xiaoqu is still far from complete, let alone the starters produced by new processes. Here, Illumina MiSeq high-throughput sequencing was applied to study bacterial composition in three types of xiaoqu used in Cantonese soybean-flavor ( Chi -flavor) liquor, namely two traditional starters ( Jiu Bing and Bing Wan ) and a Round-Koji-maker starter ( San qu ) produced by the automatic starter-making disk machine. The results showed bacterial diversity in traditional starters was similar and higher than that in the Round-Koji-maker starter. Lactobacillus and Pediococcus were the dominant genera in all starters, while other different dominant genera also existed in different starters, which were Weissella, Acetobacter , and Gluconobacter for Jiu Bing, Weissella for Bing Wan , and Bacillus, Acetobacter, Acinetobacter and Klebsiella for San qu , respectively. Meanwhile, Cytophagaceae , one particular microbial family, and some pathogens including Klebsiella, Cronobacter , and Enterobacter were also found in San qu , indicating the automatic starter-making disk machine should be ameliorated before applied into industrial production. These results enriched our knowledge on xiaoqu -related microorganisms and might be helpful in industrial Chi -flavor liquor production and the development of fermentation technology.

Evaluation of freeze-dried kefir coculture as starter in feta-type cheese production.

PubMed

Kourkoutas, Y; Kandylis, P; Panas, P; Dooley, J S G; Nigam, P; Koutinas, A A

2006-09-01

The use of freeze-dried kefir coculture as a starter in the production of feta-type cheese was investigated. Maturation of the produced cheese at 4 degrees C was monitored for up to 70 days, and the effects of the starter culture, the salting method, and the ripening process on quality characteristics were studied. The use of kefir coculture as a starter led to increased lactic acid concentrations and decreased pH values in the final product associated with significantly higher conversion rates compared to salted rennet cheese. Determination of bacterial diversity at the end of the ripening process in salted kefir and rennet cheeses by denaturing gradient gel electrophoresis technology, based on both DNA and RNA analyses, suggested a potential species-specific inhibition of members of the genera Staphylococcus and Psychrobacter by kefir coculture. The main active microbial associations in salted kefir cheese appeared to be members of the genera Pseudomonas and Lactococcus, while in salted rennet cheese, Oxalobacteraceae, Janthinobacterium, Psychrobacter, and Pseudomonas species were noted. The effect of the starter culture on the production of aroma-related compounds responsible for cheese flavor was also studied by the solid-phase microextraction-gas chromatography-mass spectrometry technique. Kefir coculture also appeared to extend the shelf life of unsalted cheese. Spoilage of kefir cheese was observed on the 9th and 20th days of preservation at 10 and 5 degrees C, respectively, while spoilage in the corresponding rennet cheese was detected on the 7th and 16th days. Microbial counts during preservation of both types of unsalted cheese increased steadily and reached similar levels, with the exception of staphylococci, which were significantly lower in unsalted kefir cheese. All types of cheese produced with kefir as a starter were approved and accepted by the panel during the preliminary sensory evaluation compared to commercial feta-type cheese.

PH-sensing 96-well microtitre plates for the characterization of acid production by dairy starter cultures.

PubMed

John, Gernot T; Goelling, Detlef; Klimant, Ingo; Schneider, Holger; Heinzle, Elmar

2003-08-01

A new method for characterization of acid production by dairy starter cultures is presented. Microplates with integrated optical pH sensors are developed. Two fluorophores, a pH-sensitive and a pH-insensitive one are immobilised at the bottom of a polystyrene 96-well microtitre plate. The pH-insensitive fluorophore serves as an internal reference and makes calibration unnecessary. The sensor measures pH accurately in optically well-defined media. Particles and fluorophores contained in the bulk medium disturbed the measurements. Despite these disturbances it was possible to clearly sense differences in inoculum type and in inoculum sizes of cultures of Lactococcus lactis and of Streptococcus thermophilus at 30 and 37 degrees C. Besides a pH-related signal there is information about other changes during milk fermentation. The cultivation results were compared with those from the established CINAC-method. From this comparison it can be concluded that the new method can be used reliably to characterize particularly a large number of strains for screening purposes but also for quality control.

Modeling Lactic Fermentation of Gowé Using Lactobacillus Starter Culture.

PubMed

de J C Munanga, Bettencourt; Loiseau, Gérard; Grabulos, Joël; Mestres, Christian

2016-12-01

A global model of the lactic fermentation step of gowé was developed by assembling blocks hosting models for bacterial growth, lactic acid production, and the drop of pH during fermentation. Commercial strains of Lactobacillus brevis and of Lactobacillus plantarum were used; their growth was modeled using Rosso's primary model and the gamma concept as a secondary model. The optimum values of pH and temperature were 8.3 ± 0.3, 44.6 ± 1.2 °C and 8.3 ± 0.3, 3.2 ± 37.1 °C with μ max values of 1.8 ± 0.2 and 1.4 ± 0.1 for L. brevis and L. plantarum respectively. The minimum inhibitory concentration of undissociated lactic acid was 23.7 mM and 35.6 mM for L. brevis and L. plantarum , respectively. The yield of lactic acid was five times higher for L. plantarum than for L. brevis , with a yield of glucose conversion to lactic acid close to 2.0 for the former and 0.8 for the latter. A model was developed to predict the pH drop during gowé fermentation. The global model was partially validated during manufacturing of gowé. The global model could be a tool to aid in the choice of suitable starters and to determine the conditions for the use of the starter.

Starter cultures as biocontrol strategy to prevent Brettanomyces bruxellensis proliferation in wine.

PubMed

Berbegal, Carmen; Spano, Giuseppe; Fragasso, Mariagiovanna; Grieco, Francesco; Russo, Pasquale; Capozzi, Vittorio

2018-01-01

Brettanomyces bruxellensis is a common and significant wine spoilage microorganism. B. bruxellensis strains generally detain the molecular basis to produce compounds that are detrimental for the organoleptic quality of the wine, including some classes of volatile phenols that derive from the sequential bioconversion of specific hydroxycinnamic acids such as ferulate and p-coumarate. Although B. bruxellensis can be detected at any stage of the winemaking process, it is typically isolated at the end of the alcoholic fermentation (AF), before the staring of the spontaneous malolactic fermentation (MLF) or during barrel aging. For this reason, the endemic diffusion of B. bruxellensis leads to consistent economic losses in the wine industry. Considering the interest in reducing sulfur dioxide use during winemaking, in recent years, biological alternatives, such as the use of tailored selected yeast and bacterial strains inoculated to promote AF and MLF, are actively sought as biocontrol agents to avoid the "Bretta" character in wines. Here, we review the importance of dedicated characterization and selection of starter cultures for AF and MLF in wine, in order to reduce or prevent both growth of B. bruxellensis and its production of volatile phenols in the matrix.

Effects of copper supplement on growth and viability of strains used as starters and adjunct cultures for Emmental cheese manufacture.

PubMed

Rodríguez, L Mato; Alatossava, T

2008-10-01

To determine the effects of supplemented copper (Cu2+) on growth and viability of strains used as starters and adjunct cultures for Emmental cheese manufacture. Thirteen strains belonging to Lactobacillus delbrueckii, Lactobacillus helveticus, Lactobacillus rhamnosus, Streptococcus thermophilus or Propionibacterium freudenreichii species were exposed to various copper concentrations in the proper growth medium at relevant growth temperatures, and the effects of supplemented copper on bacterial growth and cell viability were determined by optical density and pH measurements, also by platings. Among the species considered, L. delbrueckii was the most copper resistant and S. thermophilus the most sensitive to copper. Anaerobic conditions increased this sensitivity significantly. There was also a considerable amount of variation in copper resistance at strain level. Copper resistance is both a species- and strain-dependent property and may reflect variability in copper-binding capacities by cell wall components among species and strains. In addition, the chemical state of copper may be involved. This study revealed that copper resistance is a highly variable property among starter and adjunct strains, and this variability should be considered when strains are selected for Emmental cheese manufacture.

Peptide profiling of bovine kefir reveals 236 unique peptides released from caseins during its production by starter culture or kefir grains.

PubMed

Ebner, Jennifer; Aşçı Arslan, Ayşe; Fedorova, Maria; Hoffmann, Ralf; Küçükçetin, Ahmet; Pischetsrieder, Monika

2015-03-18

Kefir has a long tradition in human nutrition due to its presupposed health promoting effects. To investigate the potential contribution of bioactive peptides to the physiological effects of kefir, comprehensive analysis of the peptide profile was performed by nano-ESI-LTQ-Orbitrap MS coupled to nano-ultrahigh-performance liquid chromatography. Thus, 257 peptides were identified, mainly released from β-casein, followed by αS1-, κ-, and αS2-casein. Most (236) peptides were uniquely detected in kefir, but not in raw milk indicating that the fermentation step does not only increase the proteolytic activity 1.7- to 2.4-fold compared to unfermented milk, but also alters the composition of the peptide fraction. The influence of the microflora was determined by analyzing kefir produced from traditional kefir grains or commercial starter culture. Kefir from starter culture featured 230 peptide sequences and showed a significantly, 1.4-fold higher proteolytic activity than kefir from kefir grains with 127 peptides. A match of 97 peptides in both varieties indicates the presence of a typical kefir peptide profile that is not influenced by the individual composition of the microflora. Sixteen of the newly identified peptides were previously described as bioactive, including angiotensin-converting enzyme (ACE)-inhibitory, antimicrobial, immunomodulating, opioid, mineral binding, antioxidant, and antithrombotic effects. The present study describes a comprehensive peptide profile of kefir comprising 257 sequences. The peptide list was used to identify 16 bioactive peptides with ACE-inhibitory, antioxidant, antithrombotic, mineral binding, antimicrobial, immunomodulating and opioid activity in kefir. Furthermore, it was shown that a majority of the kefir peptides were not endogenously present in the raw material milk, but were released from milk caseins by proteases of the microbiota and are therefore specific for the product. Consequently, the proteolytic activity and the

Impulse noise generated by starter pistols

PubMed Central

Meinke, Deanna K.; Finan, Donald S.; Soendergaard, Jacob; Flamme, Gregory A.; Murphy, William J.; Lankford, James E.; Stewart, Michael

2015-01-01

Objective This study describes signals generated by .22 and .32 caliber starter pistols in the context of noise-induced hearing loss risk for sports officials and athletes. Design Acoustic comparison of impulses generated from typical .22 and .32 caliber starter pistols firing blanks were made to impulses generated from comparable firearms firing both blanks and live rounds. Acoustic characteristics are described in terms of directionality and distance from the shooter in a simulated outdoor running track. Metrics include peak sound pressure levels (SPL), A-weighted equivalent 8-hour level (LeqA8), and maximum permissible number of individual shots, or maximum permissible exposures (MPE) for the unprotected ear. Results Starter pistols produce peak SPLs above 140 dB. The numbers of MPEs are as few as five for the .22-caliber starter pistol, and somewhat higher (≤25) for the .32-caliber pistol. Conclusion The impulsive sounds produced by starter pistols correspond to MPE numbers that are unacceptably small for unprotected officials and others in the immediate vicinity of the shooter. At the distances included in this study, the risk to athletes appears to be low (when referencing exposure criteria for adults), but the sound associated with the starter pistol will contribute to the athlete’s overall noise exposure. PMID:23373743

Bacteriocins from lactic acid bacteria: production, purification, and food applications.

PubMed

De Vuyst, Luc; Leroy, Frédéric

2007-01-01

In fermented foods, lactic acid bacteria (LAB) display numerous antimicrobial activities. This is mainly due to the production of organic acids, but also of other compounds, such as bacteriocins and antifungal peptides. Several bacteriocins with industrial potential have been purified and characterized. The kinetics of bacteriocin production by LAB in relation to process factors have been studied in detail through mathematical modeling and positive predictive microbiology. Application of bacteriocin-producing starter cultures in sourdough (to increase competitiveness), in fermented sausage (anti-listerial effect), and in cheese (anti-listerial and anti-clostridial effects), have been studied during in vitro laboratory fermentations as well as on pilot-scale level. The highly promising results of these studies underline the important role that functional, bacteriocinogenic LAB strains may play in the food industry as starter cultures, co-cultures, or bioprotective cultures, to improve food quality and safety. In addition, antimicrobial production by probiotic LAB might play a role during in vivo interactions occurring in the human gastrointestinal tract, hence contributing to gut health.

High γ-aminobutyric acid production from lactic acid bacteria: Emphasis on Lactobacillus brevis as a functional dairy starter.

PubMed

Wu, Qinglong; Shah, Nagendra P

2017-11-22

γ-Aminobutyric acid (GABA) and GABA-rich foods have shown anti-hypertensive and anti-depressant activities as the major functions in humans and animals. Hence, high GABA-producing lactic acid bacteria (LAB) could be used as functional starters for manufacturing novel fermented dairy foods. Glutamic acid decarboxylases (GADs) from LAB are highly conserved at the species level based on the phylogenetic tree of GADs from LAB. Moreover, two functionally distinct GADs and one intact gad operon were observed in all the completely sequenced Lactobacillus brevis strains suggesting its common capability to synthesize GABA. Difficulties and strategies for the manufacture of GABA-rich fermented dairy foods have been discussed and proposed, respectively. In addition, a genetic survey on the sequenced LAB strains demonstrated the absence of cell envelope proteinases in the majority of LAB including Lb. brevis, which diminishes their cell viabilities in milk environments due to their non-proteolytic nature. Thus, several strategies have been proposed to overcome the non-proteolytic nature of Lb. brevis in order to produce GABA-rich dairy foods.

Modeling Lactic Fermentation of Gowé Using Lactobacillus Starter Culture

PubMed Central

de J. C. Munanga, Bettencourt; Loiseau, Gérard; Grabulos, Joël; Mestres, Christian

2016-01-01

A global model of the lactic fermentation step of gowé was developed by assembling blocks hosting models for bacterial growth, lactic acid production, and the drop of pH during fermentation. Commercial strains of Lactobacillus brevis and of Lactobacillus plantarum were used; their growth was modeled using Rosso’s primary model and the gamma concept as a secondary model. The optimum values of pH and temperature were 8.3 ± 0.3, 44.6 ± 1.2 °C and 8.3 ± 0.3, 3.2 ± 37.1 °C with μmax values of 1.8 ± 0.2 and 1.4 ± 0.1 for L. brevis and L. plantarum respectively. The minimum inhibitory concentration of undissociated lactic acid was 23.7 mM and 35.6 mM for L. brevis and L. plantarum, respectively. The yield of lactic acid was five times higher for L. plantarum than for L. brevis, with a yield of glucose conversion to lactic acid close to 2.0 for the former and 0.8 for the latter. A model was developed to predict the pH drop during gowé fermentation. The global model was partially validated during manufacturing of gowé. The global model could be a tool to aid in the choice of suitable starters and to determine the conditions for the use of the starter. PMID:27916901

Use of Psychrotolerant Lactic Acid Bacteria (Lactobacillus spp. and Leuconostoc spp.) Isolated from Chinese Traditional Paocai for the Quality Improvement of Paocai Products.

PubMed

Liu, Aiping; Li, Xiaoyan; Pu, Biao; Ao, Xiaolin; Zhou, Kang; He, Li; Chen, Shujuan; Liu, Shuliang

2017-03-29

To improve the quality of Chinese traditional Paocai, two psychrotolerant lactic acid bacteria (LAB) strains were isolated from Paocai, and the quality of Chinese Paocai product using these two strains as starter cultures was compared to a control sample fermented with aged brine at 10 °C. The results suggested that the physicochemical and sensory features of Paocai fermented with psychrotolerant LAB were more suitable for industrial applications. The nitrite content of Paocai fermented with psychrotolerant LAB was 1 mg/kg, which was significantly lower than that of the control Paocai (P < 0.05). Low-temperature fermentation with the starter cultures of psychrotolerant LAB could effectively prevent overacidity and over-ripening of the Paocai products. Additionally, Paocai fermented with psychrotolerant LAB harbored relatively simple microbial flora as revealed by polymerase chain reaction-denaturing gradient gel electrophoresis. This study provides a basis for improving the quality of Chinese traditional Paocai and the large-scale production of low-temperature Chinese traditional Paocai products.

Autochthonous starter cultures and indigenous grape variety for regional wine production.

PubMed

Garofalo, C; El Khoury, M; Lucas, P; Bely, M; Russo, P; Spano, G; Capozzi, V

2015-06-01

To characterize Oenococcus oeni strains isolated from North-Apulian wines where malic acid degradation is usually achieved by spontaneous fermentations, and to determine the influence of bacterial inoculation time on the malolactic performances in 'Nero di Troia' wine using a complete autochthonous microbial regime. Oenococcus oeni strains from wines produced with the autochthonous (Apulia Region, southern Italy) grape variety 'Uva di Troia' were isolated, selected and characterized. Multilocus sequence typing and variable number tandem repeat analysis were used to investigate intraspecific diversity. Oenococcus oeni strains were tested in co-inoculation and in sequential inoculation, with two autochthonous yeast strains previously isolated from 'Nero di Troia' wine. After a preliminary screening using co-inoculation regime, the O. oeni strains were grouped in reason of the different behaviour in malic acid performances. Results suggested that the efficient degradation of malic acid in co-inoculation is a strain-dependent characteristic. Autochthonous yeast/bacterium combinations were identified as starter culture, and used in a co-inoculation approach, for vinification of regional wines. The 'microbial terroir' of typical fermented food and beverage production represents a dynamic sector of applied research in food microbiology. In this work, we propose the use of autochthonous bacteria and yeast for wine production from an indigenous grape variety. © 2015 The Society for Applied Microbiology.

Production of potential probiotic Spanish-style green table olives at pilot plant scale using multifunctional starters.

PubMed

Rodríguez-Gómez, F; Romero-Gil, V; Bautista-Gallego, J; García-García, P; Garrido-Fernández, A; Arroyo-López, F N

2014-12-01

This work evaluates the use of two multifunctional starters of Lactobacillus pentosus species (TOMC LAB2 and TOMC LAB4) during elaboration of Manzanilla olive fruits processed according to the Spanish-style. Data show that the use of inocula at the onset of fermentation led to a proper acidification and sugar consumption of brines compared to the spontaneous process, obtaining in a shorter period of time the maximum population for lactic acid bacteria. Both inoculated L. pentosus strains were recovered at high frequencies at the end of fermentation on the olive surface, which was corroborated by RAPD-PCR analysis. In situ observation of olive epidermis slices by scanning electron microscopy revealed a strong aggregation and adhesion between microorganisms, which reached population levels of approximately 6 and 7 log10 cfu/cm(2) for yeasts and lactic acid bacteria, respectively. Enterobacteriaceae on the olive surface were also found at the onset of fermentation (∼9 log10 cfu/cm(2)), but they declined during the process and were below the detection limit at the end of fermentation. Results obtained in this study show the advantage of using multifunctional starters with the ability to adhere to the olive epidermis because, ultimately, the fruits are the food ingested by consumers. Copyright © 2014 Elsevier Ltd. All rights reserved.

Identification and characterization of filamentous fungi isolated from fermentation starters for Hong Qu glutinous rice wine brewing.

PubMed

Lv, Xu-Cong; Huang, Zhi-Qing; Zhang, Wen; Rao, Ping-Fan; Ni, Li

2012-01-01

Hong Qu glutinous rice wine is one of the most popular traditional rice wines in China. Traditionally, this wine is brewed from glutinous rice with the addition of wine fermentation starters (Hong Qu (also called red yeast rice) and White Qu). The objective of this study was to investigate the variability of filamentous fungi associated with traditional fermentation starters through a traditional culture-dependent method and a molecular identification approach. In this study, forty-three filamentous fungi were separated by traditional culture-dependent means (macro- and microscopic characteristics) from 10 fermentation starters and classified into 16 different species based on morphological examination and the internal transcribed spacer (ITS) sequences analysis. It was observed that the genus Aspergillus had the highest number (14 isolates) of isolates followed by Rhizopus (11 isolates), Monascus (5 isolates) and Penicillium (4 isolates). The species R. oryzae, A. niger, A. flavus and M. purpureus were frequently found in wine starter samples, among which R. oryzae was the most frequent species. The enzyme-producing properties (glucoamylase, α-amylase and protease) of all fungal isolates from different starters were also evaluated. A. flavus, R. oryzae and M. purpureus were found to be better glucoamylase producers. A. flavus, R. oryzae and A.oryzae exhibited higher activity of α-amylase. A. flavus and A. oryzae had higher protease activity. However, some fungal isolates of the same species exhibited a significant variability in the production levels for all determined enzyme activity. This study is the first to identify filamentous fungi associated with the starter of Hong Qu glutinous rice wine using both traditional and molecular methods. The results enrich our knowledge of liquor-related micro-organisms, and can be used to promote the development of the traditional fermentation technology.

In-vitro microbial production of conjugated linoleic acid by probiotic L. plantarum strains: Utilization as a functional starter culture in sucuk fermentation.

PubMed

Özer, Cem O; Kılıç, Birol; Kılıç, Gülden Başyiğit

2016-04-01

Twenty-three probiotic Lactobacillus plantarum strains were screened in-vitro to determine their ability to produce conjugated linoleic acid (CLA). L. plantarum AA1-2 and L. plantarum AB20-961 were identified as potential strains for CLA production. Optimum conditions for these strains to produce high levels of CLA were determined by evaluating the amount of added hydrolyzed sunflower oil (HSO) and initial pH levels in a nutrient medium. The highest CLA production was obtained in medium with pH6.0 and 2% HSO (P<0.05). Those strains were then used as starter culture in sucuk fermentation. Five sucuk treatments included a control (no starter culture), two sucuk groups with L. plantarum AA1-2 at the initial pH of 5.8 or 6.0 and two sucuk groups with L. plantarum AB20-961 at the initial pH of 5.8 or 6.0. Results indicate that L. plantarum AB20-961 produced higher amount of CLA in sucuk at initial pH of 5.8 and 6.0 levels during first 24h of fermentation compared with other groups. CLA isomer concentration decreased in all sucuk groups during the rest of the fermentation period (P<0.05) and remained quite stable during the storage. This study demonstrated that probiotic L. plantarum AB20-961 can be used in sucuk manufacturing without posing any quality problems. Copyright © 2015 Elsevier Ltd. All rights reserved.

Impact of starter culture, ingredients, and flour type on sourdough bread volatiles as monitored by selected ion flow tube-mass spectrometry.

PubMed

Van Kerrebroeck, Simon; Comasio, Andrea; Harth, Henning; De Vuyst, Luc

2018-04-01

This study deals with the detection of volatile compounds originating from the crumb of breads made with sourdoughs obtained through starter culture-initiated fermentations, which differed in flour type (wheat and teff), ingredients (citrate and malate), fermentation time (24h or 72h), and starter culture strains (homo- and heterofermentative lactic acid bacteria species and acetic acid bacteria species) applied. Therefore, selected ion flow tube-mass spectrometry (SIFT-MS) was used. SIFT-MS is an easy-to-use and promising technique in the field of food and flavor analysis. Volatile compounds of crumb samples from the breads with sourdough were measured and compared with those of reference bread crumb samples. In general, sourdough addition had a positive effect on the concentrations of the volatile compounds measured by SIFT-MS. Furthermore, a trend toward higher concentrations of several volatiles was seen upon the addition of sourdoughs that were fermented up to 72h, compared to the addition of sourdoughs that were fermented for a shorter time. Ethanol was the major volatile compound identified tentatively, next to alcohols, aldehydes, esters, terpenes, and heterocyclic compounds. Also acetoin/ethyl acetate could be identified, but these compounds could not be distinguished. Higher alcohols showed an increase upon the use of sourdough fermented for a long time. High concentrations of acetic acid were found in breads made with Gluconobacter oxydans IMDO A845-initiated sourdough, indicating its potential for sourdough production. Breads made with teff sourdoughs were distinct from wheat-based sourdough breads as to their volatile compound profiles. Copyright © 2018 Elsevier Ltd. All rights reserved.

Anti-obesity effect of kimchi fermented with Weissella koreensis OK1-6 as starter in high-fat diet-induced obese C57BL/6J mice.

PubMed

Park, J-A; Tirupathi Pichiah, P B; Yu, J-J; Oh, S-H; Daily, J W; Cha, Y-S

2012-12-01

In this study, we investigated the anti-obesity effects of kimchi (Korean traditional fermented vegetable) fermented either without starter culture or with a specific starter culture, Weissella koreensis OK1-6. C57BL/6J mice were divided into four groups (n = 7); normal diet, HF (high-fat diet), HF-KC (high-fat diet containing 3% kimchi manufactured without starter) and HF-KCO (high-fat diet containing 3% kimchi manufactured with the starter culture W. koreensis OK1-6). After 12 weeks of dietary intervention, the mice were killed, and serum and tissue samples were examined. Serum and hepatic lipid profile, insulin, leptin concentration and expression level of lipid anabolic genes like peroxisome proliferator-activated receptor γ, stearoyl-CoA desaturase-1, liver X receptor α and SREBP2 were significantly decreased (<0.05) along with body and epididymal fat pad weight in the HF-KCO group compared with the HF-KC and HF group. These results suggested that kimchi fermented with the starter W. koreensis OK1-6 has anti-obesity effects in HF-induced obese mice. These results may contribute to nutraceutical and food industries in developing functional food and probiotics based therapies for the treatment and prevention of obesity. © 2012 The Society for Applied Microbiology.

The effect of microbial starter composition on cassava chips fermentation for the production of fermented cassava flour

NASA Astrophysics Data System (ADS)

Kresnowati, M. T. A. P.; Listianingrum, Zaenudin, Ahmad; Trihatmoko, Kharisrama

2015-12-01

The processing of cassava into fermented cassava flour (fercaf) or the widely known as modified cassava flour (mocaf) presents an alternative solution to improve the competitiveness of local foods and to support national food security. However, the mass production of fercaf is being limited by several problems, among which is the availability of starter cultures. This paper presents the mapping of the effect of microbial starter compositions on the nutritional content of fercaf in order to obtain the suitable nutritional composition. Based on their enzymatic activities, the combination of Lactobacillus plantarum, Bacillus subtilis, and Aspergillus oryzae were tested during the study. In addition, commercial starter was also tested. During the fermentation, the dynamics in microbial population were measured as well as changes in cyanogenic glucoside content. The microbial starter composition was observed to affect the dynamics in microbial populationcynaogenic glucoside content of the produced fercaf. In general, steady state microbial population was reached within 12 hours of fermentation. Cyanogenic glucoside was observed to decrease along the fermentation.

Microbial dynamics and biodiversity in table olive fermentation: culture-dependent and -independent approaches

PubMed Central

Botta, Cristian; Cocolin, Luca

2012-01-01

The microbial ecology of the table olive fermentation process is a complex set of dynamics in which the roles of the lactic acid bacteria (LAB) and yeast populations are closely related, and this synergism is of fundamental importance to obtain high quality products. Several studies on the ecology of table olives, both in spontaneous fermentations and in inoculated ones, have focused on the identification and characterization of yeasts, as they play a key role in the definition of the final organoleptic profiles through the production of volatile compounds. Moreover, these are able to promote the growth of LAB, which is responsible for the stabilization of the final product through the acidification activity and the inhibition of the growth of pathogenic bacteria. The current empirical production process of table olives could be improved through the development of mixed starter cultures. These can only be developed after a deep study of the population dynamics of yeasts and LAB by means of molecular methods. Until now, most studies have exploited culture-dependent approaches to define the natural microbiota of brine and olives. These approaches have identified two main species of LAB, namely Lactobacillus plantarum and L. pentosus, while, as far as yeasts are concerned, the most frequently isolated genera are Candida, Pichia, and Saccharomyces. However, there are a few studies in literature in which a culture-independent approach has been employed. This review summarizes the state of the art of the microbial ecology of table olive fermentations and it focuses on the different approaches and molecular methods that have been applied. PMID:22783248

TangoLab-2 Card Troubleshooting

NASA Image and Video Library

2017-10-17

iss053e105442 (Oct. 17, 2017) --- Flight Engineer Mark Vande Hei swaps out a payload card from the TangoLab-1 facility and places into the TangoLab-2 facility. TangoLab provides a standardized platform and open architecture for experimental modules called CubeLabs. CubeLab modules may be developed for use in 3-dimensional tissue and cell cultures.

Flavour profiles of dry sausages fermented by selected novel meat starter cultures.

PubMed

Erkkilä, S; Petäjä, E; Eerola, S; Lilleberg, L; Mattila-Sandholm, T; Suihko, M L

2001-06-01

Probiotic or bioprotective Lactobacillus rhamnosus strains GG, LC-705 and E-97800 as well as Pediococcus pentosaceus E-90390 and Lactobacillus plantarum E-98098 were studied for their ability to act as main fermenting organisms in the manufacturing process of dry sausages. In the preliminary tests, their abilities to produce lactic acid and biogenic amines, histamine or tyramine, were studied in MRS broth and analysed by high-performance liquid chromatography. The strains produced higher or equal amounts of lactic acid compared to control and were amine negative. During the actual fermentation process of dry sausages the numbers of inoculated bacteria increased from the level 6.5-7.0 log cfu/g to 8.0-9.0 log cfu/g. The most fast growing strains were P. pentosaceus E-90390 and the control while the growth of L. plantarum E-98098 and L. rhamnosus LC-705 were the slowest. The pH value of the sausages decreased from 5.6 to 4.9-5.0. The presence of these experimental strains as major organisms in the sausages after fermentation and ripening was confirmed on the bases of their genetic fingerprints. The flavour profiles of the experimental sausages produced by these probiotic or protective strains were similar with that produced by the commercial meat starter culture and commercial North European dry sausage recipe.

Molecular discrimination of lactobacilli used as starter and probiotic cultures by amplified ribosomal DNA restriction analysis.

PubMed

Roy, D; Sirois, S; Vincent, D

2001-04-01

Lactic acid bacteria such as Lactobacillus helveticus, L. delbrueckii subsp. delbrueckii, L. delbrueckii subsp. lactis, L. delbrueckii subsp. bulgaricus, L. acidophilus, and L. casei related taxa which are widely used as starter or probiotic cultures can be identified by amplified ribosomal DNA restriction analysis (ARDRA). The genetic discrimination of the related species belonging to these groups was first obtained by PCR amplifications by using group-specific or species-specific 16S rDNA primers. The numerical analysis of the ARDRA patterns obtained by using CfoI, HinfI, Tru9I, and ScrFI was an efficient typing tool for identification of species of the L. acidophilus and L. casei complex. ARDRA by using CfoI was a reliable method for differentiation of L. delbrueckii subsp. bulgaricus and L. delbrueckii subsp. lactis. Finally, strains ATCC 393 and ATCC 15820 exhibited unique ARDRA patterns with CfoI and Tru9I restriction enzymes as compared with the other strains of L. casei, L. paracasei, and L. rhamnosus.

Identification of yeasts and evaluation of their distribution in Taiwanese Kefir and Viili starters.

PubMed

Wang, S Y; Chen, H C; Liu, J R; Lin, Y C; Chen, M J

2008-10-01

The objective of the present study was to investigate yeast communities in kefir grains and viili starters in Taiwan through conventional microbiological cultivation and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). The DNA sequencing was used as a validity technique to ensure that all isolates within each group belonged to just one species, and to confirm the identified results of PCR-DGGE. Results indicated that a combination of conventional microbiological cultivation with PCR-DGGE and sequencing could successfully identify 4 yeast species from both types of cultures in Taiwan. Kluyveromyces marxianus, Saccharomyces turicensis, and Pichia fermentans were found in Taiwanese kefir grains with a distribution of 76, 22, and 2%, respectively, whereas Klu. marxianus, Saccharomyces unisporus and P. fermentans were identified in viili starters corresponding to 58, 11, and 31% of the total cell counts, respectively. Furthermore, the culture-independent method was applied to identify the yeast species using DGGE. Only 2 yeast species, Klu. marxianus and S. turicensis, were found in kefir grains and 2, Klu. marxianus and P. fermentans, in viili starters. These results suggest that in samples containing multiple species, PCR-DGGE may fail to detect some species. Sequences of yeast isolates reported in this study have been deposited in the GenBank database under accession nos. DQ139802, AF398485, DQ377652, and AY007920.

Characterization of starter kimchi fermented with Leuconostoc kimchii GJ2 and its cholesterol-lowering effects in rats fed a high-fat and high-cholesterol diet.

PubMed

Jo, Se Yeon; Choi, Eun A; Lee, Jae Joon; Chang, Hae Choon

2015-10-01

The hypocholesterolemic effects of lactic acid bacteria and kimchi have been demonstrated previously. However, the kimchi fermentation process still relies on naturally present microorganisms. To obtain functional kimchi with consistent quality, we validated the capacity of Leuconostoc kimchii GJ2 as a starter culture to control kimchi fermentation. Moreover, cholesterol-lowering effects of starter kimchi as a health-promoting product were explored. Bacteriocin production by Lc. kimchii GJ2 was highly enhanced in the presence of 5% Lactobacillus sakei NJ1 cell fractions. When kimchi was fermented with bacteriocin-enhanced Lc. kimchii GJ2, Lc. kimchii GJ2 became overwhelmingly predominant (98.3%) at the end of fermentation and maintained its dominance (up to 82%) for 84 days. Growing as well as dead cells of Lc. kimchii GJ2 showed high cholesterol assimilation (in vitro). Rats were fed a high-fat and high-cholesterol diet supplemented with starter kimchi. The results showed that feeding of starter kimchi significantly reduced serum total cholesterol, triglyceride and low-density lipoprotein cholesterol levels. Additionally, atherogenic index, cardiac risk factor and triglyceride and total cholesterol levels in liver and epididymal adipose tissue decreased significantly in rats fed starter kimchi. Kimchi fermented with Lc. kimchii GJ2 as a starter culture has efficient cholesterol-lowering effects. © 2014 Society of Chemical Industry.

Use of Tetragenococcus halophilus as a starter culture for flavor improvement in fish sauce fermentation.

PubMed

Udomsil, Natteewan; Rodtong, Sureelak; Choi, Yeung Joon; Hua, Yanglin; Yongsawatdigul, Jirawat

2011-08-10

The potential of Tetragenococcus halophilus as a starter culture for flavor improvement in fish sauce fermentation was elucidated. Four strains of T. halophilus isolated from fish sauce mashes were inoculated to anchovy mixed with 25% NaCl with an approximate cell count of 10(6) CFU/mL. The α-amino content of 6-month-old fish sauce samples inoculated with T. halophilus was 780-784 mM. The addition of T. halophilus MRC10-1-3 and T. halophilus MCD10-5-10 resulted in a reduction of histamine (P < 0.05). Fish sauce inoculated with T. halophilus showed high contents of total amino acids with predominantly high glutamic acid. Major volatile compounds in fish sauce were 2-methylpropanal, 2-methylbutanal, 3-methylbutanal, and benzaldehyde. T. halophilus-inoculated fish sauce samples demonstrated the ability to reduce dimethyl disulfide, a compound contributing to a fecal note. The use of T. halophilus for fish sauce fermentation improves amino acid profiles and volatile compounds as well as reduces biogenic amine content of a fish sauce product.

A Multibacteriocin Cheese Starter System, Comprising Nisin and Lacticin 3147 in Lactococcus lactis, in Combination with Plantaricin from Lactobacillus plantarum

PubMed Central

Mills, S.; Griffin, C.; O'Connor, P. M.; Serrano, L. M.; Meijer, W. C.; Hill, C.

2017-01-01

ABSTRACT Functional starter cultures demonstrating superior technological and food safety properties are advantageous to the food fermentation industry. We evaluated the efficacies of single- and double-bacteriocin-producing starters of Lactococcus lactis capable of producing the class I bacteriocins nisin A and/or lacticin 3147 in terms of starter performance. Single producers were generated by mobilizing the conjugative bacteriophage resistance plasmid pMRC01, carrying lacticin genetic determinants, or the conjugative transposon Tn5276, carrying nisin genetic determinants, to the commercial starter L. lactis CSK2775. The effect of bacteriocin coproduction was examined by superimposing pMRC01 into the newly constructed nisin transconjugant. Transconjugants were improved with regard to antimicrobial activity and bacteriophage insensitivity compared to the recipient strain, and the double producer was immune to both bacteriocins. Bacteriocin production in the starter was stable, although the recipient strain proved to be a more efficient acidifier than transconjugant derivatives. Overall, combinations of class I bacteriocins (the double producer or a combination of single producers) proved to be as effective as individual bacteriocins for controlling Listeria innocua growth in laboratory-scale cheeses. However, using the double producer in combination with the class II bacteriocin producer Lactobacillus plantarum or using the lacticin producer with the class II producer proved to be most effective for reducing bacterial load. As emergence of bacteriocin tolerance was reduced 10-fold in the presence of nisin and lacticin, we suggest that the double producer in conjunction with the class II producer could serve as a protective culture providing a food-grade, multihurdle approach to control pathogenic growth in a variety of industrial applications. IMPORTANCE We generated a suite of single- and double-bacteriocin-producing starter cultures capable of generating the

Passion fruit by-product and fructooligosaccharides stimulate the growth and folate production by starter and probiotic cultures in fermented soymilk.

PubMed

Albuquerque, Marcela Albuquerque Cavalcanti; Bedani, Raquel; LeBlanc, Jean Guy; Saad, Susana Marta Isay

2017-11-16

Two starter cultures (Streptococcus (St.) thermophilus ST-M6 and TA-40) and five probiotic strains (St. thermophilus TH-4, Lactobacillus (Lb.) acidophilus LA-5, Lb. rhamnosus LGG, Lb. fermentum PCC, and Lb. reuteri RC-14) were used to ferment different soymilk formulations supplemented with passion fruit by-product and/or fructo-oligosaccharides (FOS) with the aim of increasing folate concentrations. Growth and folate production of individual strains were evaluated and the results used to select co-cultures. Both St. thermophilus ST-M6 and TH-4 were the best folate producers and were able to increase the folate content of all soymilk formulations when used alone or in co-culture with lactobacilli strains, especially in the presence of both passion fruit by-product and FOS. Thus, passion fruit by-product and FOS could be used as dietary ingredients to stimulate the folate production by selected bacterial strains during the fermentation of soymilk. It was also shown that vitamin production by microorganisms is strain-dependent and may also be influenced by nutritional and environmental conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of Bacillus spp. as dough starters for Adhirasam - A traditional rice based fermented food of Southern India.

PubMed

Anisha, Anvar Hussain Noorul; Anandham, Rangasamy; Kwon, Soon Woo; Gandhi, Pandiyan Indira; Gopal, Nellaiappan Olaganathan

2015-01-01

Adhirasam is a cereal based, doughnut shaped, deep fried dessert consumed in the southern regions of India. The dough used to prepare adhirasam is fermented and contains rice flour and jaggery. The aim of the present study was to characterize the cultivable bacteria associated with this fermented dough and to identify a suitable starter culture for the production of quality adhirasam. In total, one hundred and seventy bacterial isolates were recovered from de Man Rogosa Sharp (MRS) agar, nutrient agar, lysogeny agar and tryptic soy agar media. Out of the 170 bacterial isolates, sixteen isolates were selected based on their ability to tolerate glucose and sucrose. All the bacterial isolates tolerated 15% glucose and 30% sucrose. Analyses of 16S rDNA gene sequences of the bacterial isolates showed that the dominant cultivable bacteria were members of the genus Bacillus. These strains were further used as starters and tested for their ability to ferment rice flour with jaggery to produce adhirasam dough. Organoleptic evaluation was carried out to choose the best starter strain. Adhirasam prepared from Bacillus subtilis isolates S4-P11, S2-G2-A1 and S1-G15, Bacillus tequilensis isolates S2-H16, S3-P9, S3-G10 and Bacillus siamensis isolate S2-G13 were highly acceptable to consumers. Adhirasam prepared using these starter cultures had superior product characteristics such as softness in texture, flavor and enhanced aroma and sweet taste.

Evaluation of Bacillus spp. as dough starters for Adhirasam - A traditional rice based fermented food of Southern India

PubMed Central

Anisha, Anvar Hussain Noorul; Anandham, Rangasamy; Kwon, Soon Woo; Gandhi, Pandiyan Indira; Gopal, Nellaiappan Olaganathan

2015-01-01

Abstract Adhirasam is a cereal based, doughnut shaped, deep fried dessert consumed in the southern regions of India. The dough used to prepare adhirasam is fermented and contains rice flour and jaggery. The aim of the present study was to characterize the cultivable bacteria associated with this fermented dough and to identify a suitable starter culture for the production of quality adhirasam. In total, one hundred and seventy bacterial isolates were recovered from de Man Rogosa Sharp (MRS) agar, nutrient agar, lysogeny agar and tryptic soy agar media. Out of the 170 bacterial isolates, sixteen isolates were selected based on their ability to tolerate glucose and sucrose. All the bacterial isolates tolerated 15% glucose and 30% sucrose. Analyses of 16S rDNA gene sequences of the bacterial isolates showed that the dominant cultivable bacteria were members of the genus Bacillus. These strains were further used as starters and tested for their ability to ferment rice flour with jaggery to produce adhirasam dough. Organoleptic evaluation was carried out to choose the best starter strain. Adhirasam prepared from Bacillus subtilis isolates S4-P11, S2-G2-A1 and S1-G15, Bacillus tequilensis isolates S2-H16, S3-P9, S3-G10 and Bacillus siamensis isolate S2-G13 were highly acceptable to consumers. Adhirasam prepared using these starter cultures had superior product characteristics such as softness in texture, flavor and enhanced aroma and sweet taste. PMID:26691480

Characterisation and biochemical properties of predominant lactic acid bacteria from fermenting cassava for selection as starter cultures.

PubMed

Kostinek, M; Specht, I; Edward, V A; Pinto, C; Egounlety, M; Sossa, C; Mbugua, S; Dortu, C; Thonart, P; Taljaard, L; Mengu, M; Franz, C M A P; Holzapfel, W H

2007-03-20

the 32 a total of 16 strains were finally selected for the development as starter cultures for Gari production.

Reduction of the degradation activity of umami-enhancing purinic ribonucleotide supplement in miso by the targeted suppression of acid phosphatases in the Aspergillus oryzae starter culture.

PubMed

Marui, Junichiro; Tada, Sawaki; Fukuoka, Mari; Wagu, Yutaka; Shiraishi, Yohei; Kitamoto, Noriyuki; Sugimoto, Tatsuya; Hattori, Ryota; Suzuki, Satoshi; Kusumoto, Ken-Ichi

2013-09-02

Miso (fermented soybean paste) is a traditional Japanese fermented food, and is now used worldwide. The solid-state culture of filamentous fungus, Aspergillus oryzae, grown on rice is known as rice-koji, and is important as a starter for miso fermentation because of its prominent hydrolytic enzyme activities. Recently, commercial miso products have been supplemented with purinic ribonucleotides, such as inosine monophosphate (IMP) and guanine monophosphate, to enhance the characteristic umami taste of glutamate in miso. Because the purinic ribonucleotides are degraded by enzymes such as acid phosphatases in miso, heat inactivation is required prior to the addition of these flavorings. However, heat treatment is a costly process and reduces the quality of miso. Therefore, an approach to lower acid phosphatase activities in koji culture is necessary. Transcriptional analysis using an A. oryzae KBN8048 rice-koji culture showed that eight of the 13 acid phosphatase (aph) genes were significantly down-regulated by the addition of phosphoric acid in the preparation of the culture in a concentration-dependent manner, while aphC expression was markedly up-regulated under the same conditions. The eight down-regulated genes might be under the control of the functional counterpart of the Saccharomyces cerevisiae transcriptional activator Pho4, which specifically regulates phosphatase genes in response to the ambient phosphate availability. However, the regulatory mechanism of aphC was not clear. The IMP dephosphorylation activities in rice-koji cultures of KBN8048 and the aphC deletion mutant (ΔaphC) were reduced by up to 30% and 70%, respectively, in cultures with phosphoric acid, while protease and amylase activity, which is important for miso fermentation, was minimally affected. The miso products fermented using the rice-koji cultures of KBN8048 and ΔaphC prepared with phosphoric acid had reductions in IMP dephosphorylation activity of 80% and 90%, respectively, without

Effect of diacetyl on controlling Escherichia coli O157:H7 and Salmonella Typhimurium in the presence of starter culture in a laboratory medium and during meat fermentation.

PubMed

Kang, D H; Fung, D Y

1999-09-01

Diacetyl is a flavor compound that possesses antimicrobial activity and is found in several dairy products. The effect of diacetyl on controlling the growth of two foodborne pathogens, Escherichia coli O157:H7 and Salmonella Typhimurium, when grown with Pediococcus acidilactici as a meat starter culture was evaluated in a laboratory medium and during salami fermentation. Diacetyl (50 ppm) added to each mixed culture system strongly inhibited the growth of E. coli O157:H7 and Salmonella Typhimurium in the laboratory medium (brain heart infusion, 2.3% of NaCl, 0.75% of dextrose) (P < 0.05). During meat fermentation, the growth of E. coli O157:H7 and Salmonella Typhimurium was inhibited significantly by addition of diacetyl (300 ppm) (P < 0.05) after 24 h fermentation. However, the acid production and growth of P. acidilactici were not affected by the addition of diacetyl (P > 0.05). After 24 h meat fermentation, about a 1.0-log CFU/g difference occurred in numbers of each foodborne pathogen mixed with P. acidilactici (P < 0.05) with and without 300 ppm diacetyl. Diacetyl and the acid produced by the meat starter culture reduced the growth of the two foodborne pathogens during salami fermentation. These results suggest that diacetyl can be used as a food ingredient during meat fermentation to control E. coli O157:H7 and Salmonella Typhimurium without harmful effects on the growth and acid production of P. acidilactici.

Silent Starters

ERIC Educational Resources Information Center

Morris, Emma

2011-01-01

The "silent starter" is an idea that the author was reminded of during Christopher Martin's session at the ATM conference in 2011, entitled "Big Ideas". This was a nice idea for introducing, or practising mappings, but it was not the first time the author had encountered this powerful teaching tool. The idea is best explained…

30 CFR 75.819 - Motor-starter enclosures; barriers and interlocks.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Motor-starter enclosures; barriers and...-Voltage Distribution High-Voltage Longwalls § 75.819 Motor-starter enclosures; barriers and interlocks. Compartment separation and cover interlock switches for motor-starter enclosures must be maintained in...

Multiplex PCR to detect bacteriophages from natural whey cultures of buffalo milk and characterisation of two phages active against Lactococcus lactis, ΦApr-1 and ΦApr-2.

PubMed

Aprea, Giuseppe; Mullan, William Michael; Murru, Nicoletta; Fitzgerald, Gerald; Buonanno, Marialuisa; Cortesi, Maria Luisa; Prencipe, Vincenza Annunziata; Migliorati, Giacomo

2017-09-30

This work investigated bacteriophage induced starter failures in artisanal buffalo Mozzarella production plants in Southern Italy. Two hundred and ten samples of whey starter cultures were screened for bacteriophage infection. Multiplex polymerase chain reaction (PCR) revealed phage infection in 28.56% of samples, all showing acidification problems during cheese making. Based on DNA sequences, bacteriophages for Lactococcus lactis (L. lactis), Lactobacillus delbruekii (L. delbruekii) and Streptococcus thermophilus (S. thermophilus) were detected. Two phages active against L. lactis, ΦApr-1 and ΦApr-2, were isolated and characterised. The genomes, approximately 31.4 kb and 31 kb for ΦApr-1 and ΦApr-2 respectively, consisted of double-stranded linear DNA with pac-type system. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‑PAGE) showed one major structural protein of approximately 32.5 kDa and several minor proteins. This is the first report of phage isolation in buffalo milk and of the use of multiplex PCR to screen and study the diversity of phages against Lactic Acid Bacteria (LAB) strains in artisanal Water Buffalo Mozzarella starters.

Crankshaft position sensing with combined starter alternator

DOEpatents

Brandenburg, Larry Raymond; Miller, John Michael

2000-06-13

A crankshaft position sensing apparatus for use with an engine (16) having a combined starter/alternator assembly (18). The crankshaft position sensing apparatus includes a tone ring (38) with a sensor (36) and bandpass filter (46), having a cylinder identification input from a camshaft sensor (48), and a gain limiter (54). The sensing apparatus mounts near the rotor (30) of the combined starter/alternator assembly (18). The filtered crankshaft position signal can then be input into a vehicle system controller (58) and an inner loop controller (60). The starter/alternator assembly (18) in combination with an internal combustion engine is particularly useful for a hybrid electric vehicle system.

Effect of Novel Starter Culture on Reduction of Biogenic Amines, Quality Improvement, and Sensory Properties of Doenjang, a Traditional Korean Soybean Fermented Sauce Variety.

PubMed

Shukla, Shruti; Lee, Jong Suk; Park, Hae-Kyong; Yoo, Jung-Ah; Hong, Sung-Yong; Kim, Jong-Kyu; Kim, Myunghee

2015-08-01

To select appropriate microorganisms as starter cultures for the reliable and reproducible fermentation of soybean fermented products of Korean Doenjang, various ratios of fungi (Aspergillus oryzae J, Mucor racemosus 15, M. racemosus 42) combined with Bacillus subtilis TKSP 24 were selected as either single, double, or multiple Meju strains for commercial mass production of Doenjang, followed by analysis of sensory characteristics. In the sensory evaluation, Doenjang BAM15-1 and BAM42-1, which were fermented with multiple strains (1:1:1), showed the highest sensory scores as compared to control. Based on sensory characteristics, 6 Doenjang samples were subjected to quantitative determination of amino acids, free sugars, and organic acids (volatile and nonvolatile) contents, followed by determination of biogenic amines. Total sweet taste amino acid contents were highest in BAM15-1 and BAM42-1 samples (333.7 and 295.8 mg/100 g, respectively) and similar that of control (391.1 mg/100 g). Samples BAM15-1 and BAM42-1 showed the relatively high volatile and nonvolatile organic acid contents (154.24, 192.26, and 71.31, 82.42 mg/100 g, respectively). In addition, BAM15-1 and BAM42-1 showed negligible biogenic amine formation, ranging from 0.00 to 1.02 and 0.00 to 3.92 mg/100 g, respectively. These findings indicate that determination of food components along with sensory and quality attributes using multiple microbial Meju strains as a starter culture may provide substantial results on improved quality fermented Doenjang products. © 2015 Institute of Food Technologists®

Prediction of percutaneous absorption in human using three-dimensional human cultured epidermis LabCyte EPI-MODEL.

PubMed

Hikima, Tomohiro; Kaneda, Noriaki; Matsuo, Kyouhei; Tojo, Kakuji

2012-01-01

The objective of this study is to establish a relationship of the skin penetration parameters between the three-dimensional cultured human epidermis LabCyte EPI-MODEL (LabCyte) and hairless mouse (HLM) skin penetration in vitro and to predict the skin penetration and plasma concentration profile in human. The skin penetration experiments through LabCyte and HLM skin were investigated using 19 drugs that have a different molecular weight and lipophilicity. The penetration flux for LabCyte reached 30 times larger at maximum than that for HLM skin. The human data can be estimated from the in silico approach with the diffusion coefficient (D), the partition coefficient (K) and the skin surface concentration (C) of drugs by assuming the bi-layer skin model for both LabCyte and HLM skin. The human skin penetration of β-estradiol, prednisolone, testosterone and ethynylestradiol was well agreed between the simulated profiles and in vitro experimental data. Plasma concentration profiles of β-estradiol in human were also simulated and well agreed with the clinical data. The present alternative method may decrease human or animal skin experiment for in vitro skin penetration.

Potential of bacteriocins from lab to improve microbial quality of dry-cured and fermented meat products.

PubMed

Kęska, Paulina; Stadnik, Joanna; Zielińska, Dorota; Kołożyn-Krajewska, Danuta

2017-01-01

Meat and meat products are an important component of the daily diet. Nevertheless, they are perishable goods and are prone to microbial contamination, which leads to an increased risk to the health of consumers as well as economic losses in the meat industry. Fermentation has been used for thousands of years to preserve meat. As a result of extensive biochemical reactions occurring in meat during fermentation and ripening, the condi- tions inhibiting the growth of pathogenic and spoilage bacteria are formed. These changes are catalyzed by endogenous meat enzymes and exogenous enzymes derived from natural contaminating bacteria or starter cultures applied. In dry-cured and fermented meat products they are represented mainly by lactic acid bacte- ria (LAB) that produce a wide range of compounds, such as bacteriocins, directed against other microorgan- isms. The use of bactericidal peptides does not affect the sensory quality of foodstuffs, so that they attract attention as alternative means of preserving the stability and safety of dry-cured products.

Direct Application of Rep-PCR on Type I Sourdough Matrix to Monitor the Dominance and Persistence of a Lactobacillus plantarum Starter Throughout Back-Slopping.

PubMed

Dolci, Paola; Cocolin, Luca

2017-08-01

This study describes the optimization and application of repetitive element-PCR (rep-PCR) technique directly on microbial DNA extracted from type I sourdoughs for fast monitoring of a Lb. plantarum starter strain (P1FMC) throughout daily back-slopping. The challenge was to follow and study the performance of a starter culture directly in sourdoughs without cultivation on selective media. The extraction of good quality microbial DNA suitable for amplification from a complex matrix such as dough was the first target. In addition, the objective to obtain a clear rep-PCR profile referable to a specific starter strain among a microbial community was pursued. Co-inoculum trials, in flour matrix, with Lb. plantarum P1FMC and L. lactis LC71 strains and, subsequently, type I sourdough back-slopping trials were performed. The rep-PCR amplification profiles obtained were clearly referable to that of Lb. plantarum P1FMC starter in both co-inoculum trials (also when it was present with one order of magnitude less with respect to L. lactis LC71) and back-slopping trials where it dominated the fermentation process with loads of 10 8 cfu g -1 and prevailed on the autochthonous microbiota. Thus, the approach proposed in this paper could be considered a methodological advancement, based on a culture-independent one-step rep-PCR, suitable for fast monitoring of starter performance. © 2017 Institute of Food Technologists®.

Selection of enhanced antimicrobial activity posing lactic acid bacteria characterised by (GTG)5-PCR fingerprinting.

PubMed

Šalomskienė, Joana; Abraitienė, Asta; Jonkuvienė, Dovilė; Mačionienė, Irena; Repečkienė, Jūratė

2015-07-01

The aim of the study was a detail evaluation of genetic diversity among the lactic acid bacteria (LAB) strains having an advantage of a starter culture in order to select genotypically diverse strains with enhanced antimicrobial effect on some harmfull and pathogenic microorganisms. Antimicrobial activity of LAB was performed by the agar well diffusion method and was examined against the reference strains and foodborne isolates of Bacillus cereus, Listeria monocytogenes, Escherichia coli, Staphylococcus aureus and Salmonella Typhimurium. Antifungal activity was tested against the foodborne isolates of Candida parapsilosis, Debaromyces hansenii, Kluyveromyces marxianus, Pichia guilliermondii, Yarowia lipolytica, Aspergillus brasiliensis, Aspergillus versicolor, Cladosporium herbarum, Penicillium chrysogenum and Scopulariopsis brevicaulis. A total 40 LAB strains representing Lactobacillus (23 strains), Lactococcus (13 strains) and Streptococcus spp. (4 strains) were characterised by repetitive sequence based polymerase chain reaction fingerprinting which generated highly discriminatory profiles, confirmed the identity and revealed high genotypic heterogeneity among the strains. Many of tested LAB demonstrated strong antimicrobial activity specialised against one or few indicator strains. Twelve LAB strains were superior in suppressing growth of the whole complex of pathogenic bacteria and fungi. These results demonstrated that separate taxonomic units offered different possibilities of selection for novel LAB strains could be used as starter cultures enhancing food preservation.

Biodiversity and technological-functional potential of lactic acid bacteria isolated from spontaneously fermented quinoa sourdoughs.

PubMed

Ruiz Rodríguez, L; Vera Pingitore, E; Rollan, G; Cocconcelli, P S; Fontana, C; Saavedra, L; Vignolo, G; Hebert, E M

2016-05-01

To analyse lactic acid bacteria (LAB) diversity and technological-functional and safety properties of strains present during spontaneous fermented quinoa sourdoughs. Fermentation was performed by daily backslopping at 30°C for 10 days. Autochthonous LAB microbiota was monitored by a biphasic approach combining random amplified polymorphic DNA (RAPD)-PCR and rRNA gene sequencing with PCR-denaturing gradient gel electrophoresis (DGGE) analysis. Identification and intraspecies differentiation allowed to group isolates within nine LAB species belonging to four genera. A succession of LAB species occurred during 10-days backslopping; Lactobacillus plantarum and Lactobacillus brevis were detected as dominant species in the consortium. The characterization of 15 representative LAB strains was performed based on the acidifying capacity, starch and protein hydrolysis, γ-aminobutyric acid and exopolysaccharides production, antimicrobial activity and antibiotic resistance. Strains characterization led to the selection of Lact. plantarum CRL1905 and Leuconostoc mesenteroides CRL1907 as candidates to be assayed as functional starter culture for the gluten-free (GF) quinoa fermented products. Results on native LAB microbiota present during quinoa sourdough fermentation will allow the selection of strains with appropriate technological properties to be used as a novel functional starter culture for GF-fermented products. © 2016 The Society for Applied Microbiology.

Yeast Starter as a Biotechnological Tool for Reducing Copper Content in Wine

PubMed Central

Capece, Angela; Romaniello, Rossana; Scrano, Laura; Siesto, Gabriella; Romano, Patrizia

2018-01-01

Copper is widely used in agriculture as a traditional fungicide in organic farming to control downy mildew on grapes, consequently it is possible to find this metal during all stages of the vinification process. Low amounts of copper play a key role on the function of key cell enzymes, whereas excess quantities can exert amount-dependent cytotoxicity, resulting in general cellular damage. Nowadays the excessive copper ions in wines is removed by addition of adsorbents, but these additives can influence the sensory characteristics of wine, as well as detrimental to the health of consumers. It is well known that high concentrations of Cu2+ can be toxic to yeasts, inhibiting growth and activity, causing sluggish fermentation and reducing alcohol production. In this study, 47 S. cerevisiae strains were tested for copper tolerance by two different tests, growth on copper added medium and fermentative activity in copper added grape must. The results obtained by the two different tests were comparable and the high strain variability found was used to select four wild strains, possessing this characteristic at the highest (PP1-13 and A20) and the lowest level (MPR2-24 and A13). The selected strains were tested in synthetic and natural grape must fermentation for ability to reduce copper content in wine. The determination of copper content in wines and yeast cells revealed that at the lowest copper residual in wine corresponded the highest content in yeast cells, indicating a strong strain ability to reduce the copper content in wine. This effect was inversely correlated with strain copper resistance and the most powerful strain in copper reduction was the most sensitive strain, MPR2-24. This wild strain was finally tested as starter culture in cellar pilot scale fermentation in comparison to a commercial starter, confirming the behavior exhibited at lab scale. The use of this wild strain to complete the alcoholic fermentation and remove the copper from wine represents a

Toxicological assessment of Penicillium nalgiovense strains for use as starter cultures in the manufacture of dry fermented sausages.

PubMed

Ludemann, Vanesa; Pose, Graciela; Moavro, Alfonsina; Maliaviabarrena, Maria G; Fandiño, Rosario; Ripoll, Giselle; Basílico, Juan C; Pardo, Alejandro G

2009-08-01

The use of fungal starter strains in the casing of dry fermented sausages allows standardization of the manufacturing process and ensures consumer safety. Penicillium nalgiovense is normally used for this purpose. Even though this species is reported as safe with respect to the production of the most common mycotoxins, its safety may be strain specific. The aim of the present work was to assess the toxicogenic potential of nine P. nalgiovense strains isolated from dry fermented sausages that were previously suitable as starters. The strains were tested for toxicity on brine shrimp larvae and the human cell line MCF7, for mutagenicity in the Ames test, and for antibacterial activity against gram-positive and gram-negative bacteria. According to our results, several P. nalgiovense strains were positive in more than one bioassay. Therefore, it is important to use different toxicological assays when characterizing strains intended for food use. Strains S1-2 and S14-4, which belong to biotypes 6 and 5, respectively, were nontoxigenic under the conditions tested. Overall, strain S1-2 of P. nalgiovense proved to be best suited as a starter in dry fermented sausage manufacture because in addition of being nontoxicogenic it produces white conidia, which is a desirable feature.

Engineering lactic acid bacteria for increased industrial functionality.

PubMed

Bron, Peter A; Kleerebezem, Michiel

2011-01-01

Based on their spoilage-preventing and flavor-contributing characteristics, lactic acid bacteria (LAB) are employed as starter cultures for the fermentation of foods and feeds. In addition, several specific LAB strains are marketed on basis of their beneficial effects on the consumer's health, representing an explosively growing market for the products containing these so-called probiotics. Due to this extensive industrial use there is a strong interest in unraveling the molecular mechanisms involved in industrial robustness, cognate stress resistance, and health-promoting phenotypes of these LAB that may vary drastically between different starter and probiotic strains currently marketed. This review describes some of the post-genomic tools developed, as well as their employment for the identification of bacterial effector molecules involved in the aforementioned industrially relevant phenotypes. Furthermore, it addresses possible strategies to exploit such knowledge into the rational design of LAB strains with increased industrial functionality.

Physiological and anthropometric characteristics of starters and non-starters and playing positions in elite Australian Rules Football: a case study.

PubMed

Young, W B; Newton, R U; Doyle, T L A; Chapman, D; Cormack, S; Stewart, G; Dawson, B

2005-09-01

A purpose of this study was to determine if pre-season anthropometric and physiological measures were significantly different for the players from one Australian Football League (AFL) club selected to play in the first game of the season compared to the players not selected. Another purpose was to compare fitness test results for defenders, forwards and mid-fielders in the same AFL club. Thirty-four players were tested for isolated quadriceps and hamstrings strength, leg extensor muscle strength and power, upper body strength, sprinting speed, vertical jump (VJ), endurance, skinfolds and hamstring flexibility. The starters who were selected to play the first game were a significantly older and more experienced playing group, and were significantly better (p < 0.05) in measures of leg power, sprinting speed and the distance covered in the Yo Yo intermittent recovery test compared to the non-starters. Although there were trends for the superiority of the starters, the differences in lower and upper body strength, VJ and predicted VO2max were non-significant. The forwards generally produced the worst fitness scores of the playing positions with the midfielders having significantly lower skinfolds and the defenders possessing better hamstring strength and VJ compared to the forwards. It was concluded that some fitness qualities can differentiate between starters and non-starters, at least in one AFL club. Comparisons of playing positions and the development of fitness norms for AFL players require further research.

The Effect of LAB as Probiotic Starter Culture and Green Tea Extract Addition on Dry Fermented Pork Loins Quality.

PubMed

Neffe-Skocińska, Katarzyna; Jaworska, Danuta; Kołożyn-Krajewska, Danuta; Dolatowski, Zbigniew; Jachacz-Jówko, Luiza

2015-01-01

The objective of this study was to evaluate the microbiological, physicochemical, and sensory quality of dry fermented pork loin produced with the addition of Lb. rhamnosus LOCK900 probiotic strain, 0.2% glucose, and 1.5% green tea extract. Three loins were prepared: control sample (P0: no additives), sample supplemented with glucose and probiotic strain (P1), and sample with glucose, green tea extract, and probiotic (P2). The samples were analyzed after 21 days of ripening and 180 days of storage. The results indicated that the highest count of LAB was observed both in the samples: with probiotic and with probiotic and green tea extract (7.00 log cfu/g after ripening; 6.00 log cfu/g after storage). The oxidation-reduction potential values were lower in the probiotic loin samples. Probiotic and green tea extract have not caused color changes of study loins during storage. The study demonstrated that an addition of probiotic and green tea extract to dry fermented loins is possible and had no impact on sensory quality after product storage.

The Effect of LAB as Probiotic Starter Culture and Green Tea Extract Addition on Dry Fermented Pork Loins Quality

PubMed Central

Jaworska, Danuta; Kołożyn-Krajewska, Danuta; Dolatowski, Zbigniew; Jachacz-Jówko, Luiza

2015-01-01

The objective of this study was to evaluate the microbiological, physicochemical, and sensory quality of dry fermented pork loin produced with the addition of Lb. rhamnosus LOCK900 probiotic strain, 0.2% glucose, and 1.5% green tea extract. Three loins were prepared: control sample (P0: no additives), sample supplemented with glucose and probiotic strain (P1), and sample with glucose, green tea extract, and probiotic (P2). The samples were analyzed after 21 days of ripening and 180 days of storage. The results indicated that the highest count of LAB was observed both in the samples: with probiotic and with probiotic and green tea extract (7.00 log cfu/g after ripening; 6.00 log cfu/g after storage). The oxidation-reduction potential values were lower in the probiotic loin samples. Probiotic and green tea extract have not caused color changes of study loins during storage. The study demonstrated that an addition of probiotic and green tea extract to dry fermented loins is possible and had no impact on sensory quality after product storage. PMID:25961018

The antagonistic activity of lactic acid bacteria isolated from peda, an Indonesian traditional fermented fish

NASA Astrophysics Data System (ADS)

Putra, T. F.; Suprapto, H.; Tjahjaningsih, W.; Pramono, H.

2018-04-01

Peda is an Indonesian traditional fermented whole fish prepared by addition of salt prior to fermentation and drying process. Salt used to control the growth of the lactic acid bacteria for the fermentation process. The objectives of this study were isolating and characterize the potential lactic acid bacteria (LAB) from peda as culture starter candidate, particularly its activity against pathogenic bacteria. A total of five samples from five regions of East Java Province was collected and subjected to LAB isolation. Fifty-seven of 108 colonies that show clear zone in de Man, Rogosa and Sharpe (MRS) agar supplemented with 0.5% CaCO3 were identified as LAB. Twenty-seven of the LAB isolates were exhibit inhibition against Staphylococcus aureus ATCC 6538 and Pseudomonas aeruginosa ATCC 27853. Isolate Aerococcus NJ-20 was exhibited strong inhibition against S. aureus ATCC 6538 (7.6 ± 1.35 mm inhibition zone) but was not produce bacteriocin. This finding suggests that the isolate Aerococcus NJ-20 can be applied as biopreservative culture starter on peda production. Further analysis on technological properties of isolates will be needed prior to application.

The Presence of Salt and a Curing Agent Reduces Bacteriocin Production by Lactobacillus sakei CTC 494, a Potential Starter Culture for Sausage Fermentation

PubMed Central

Leroy, Frédéric; de Vuyst, Luc

1999-01-01

The specific conditions in the batter of raw fermented sausages may reduce the efficiency of bacteriocin-producing starter cultures. In this work, using in vitro fermentation, we found that sodium chloride and sodium nitrite interfere with the growth of Lactobacillus sakei CTC 494, an organism which produces the antilisterial bacteriocin sakacin K. Because sakacin K production follows primary metabolite kinetics, a decrease in cell formation resulted in a decrease in sakacin K production as well. Sodium chloride dramatically influenced bacteriocin production by decreasing both biomass production and specific bacteriocin production. Sodium nitrite, however, had no effect on specific bacteriocin production and decreased bacteriocin production only because of its effect on cell growth. Moreover, sodium nitrite enhanced the toxic effect of lactic acid on bacterial growth. PMID:10583988

Differences in personality and patterns of recidivism between early starters and other serious male offenders.

PubMed

Ge, Xiaojia; Donnellan, M Brent; Wenk, Ernst

2003-01-01

In this study, the differences in personality and patterns of recidivism were compared between individuals with an early incidence of offending ("early starters") and their later-starting counterparts ("later starters"). Results indicated that early starters were significantly different from later starters in several personality characteristics, as measured by the California Personality Inventory (CPI) and the Minnesota Multiphasic Personality Inventory (MMPI). Specifically, early starters scored lower on the responsibility and socialization scales of the CPI and higher on the paranoia, schizophrenia, and hypomania scales of the MMPI. Moreover, results indicated that early starters were at a significantly higher risk for recidivism than later starters, both at a 15-month and a 20-year follow-up.

Anti-Listeria starters: in vitro selection and production plant evaluation.

PubMed

Raimondi, Stefano; Popovic, Mina; Amaretti, Alberto; Di Gioia, Diana; Rossi, Maddalena

2014-05-01

Anti-Listeria bacterial starters are highly demanded by the meat industry. Novel bioprotective anti-Listeria starters were searched among Lactobacillus species strains isolated from artisanal sausages. The screening confirmed that anti-Listeria activity is a strain-specific property and yielded only 1 strain (of 36) exhibiting a satisfactory level of inhibition, L. delbrueckii WC0286. This strain was compared with two commercial bioprotective starters, SafePro B-SF-43 and SafePro B-LC-20, in a model simulating in vitro the first step of the fermentation process. The presence of the bioprotective starters did not modify the pH in such a way that could affect the safety or organoleptic properties of the product. Both SafePro B-SF-43 and SafePro B-LC-20 effected an important reduction of Listeria counts (0.56 and 0.72 log CFU g(-1), respectively, in 72 h), while the anti-Listeria effect of L. delbrueckii WC0286 was minor (0.15 log CFU g(-1)). These results discouraged the utilization of L. delbrueckii WC0286 for a challenge test in a pilot salami production, in favor of the best-performing bioprotective starter, SafePro B-LC-20. The test confirmed that SafePro B-LC-20 did not alter the acidification trend of sausages and was capable of inhibiting Listeria, which decreased by 1.21 log CFU g(-1). This information is relevant to address research activity toward the development of new bioprotective starters. The data herein presented demonstrate that the efficacy in Listeria control of potentially bioprotective bacterial starters requires further validation in real meat matrixes, possibly by using in vitro meat fermentation experiments to narrow down the list of candidates before pilot scale challenge tests.

Serial Dilution Simulation Lab

ERIC Educational Resources Information Center

Keler, Cynthia; Balutis, Tabitha; Bergen, Kim; Laudenslager, Bryanna; Rubino, Deanna

2010-01-01

Serial dilution is often a difficult concept for students to understand. In this short dry lab exercise, students perform serial dilutions using seed beads. This exercise helps students gain skill at performing dilutions without using reagents, bacterial cultures, or viral cultures, while being able to visualize the process.

Manufacture and characterization of kefir made from cow and buffalo milk, using kefir grain and starter culture.

PubMed

Gul, O; Mortas, M; Atalar, I; Dervisoglu, M; Kahyaoglu, T

2015-03-01

The microbiological and chemical characteristics as well as organic and amino acid profiles of kefir samples made from cow and buffalo milks fermented by kefir grains and starter culture were investigated during storage for 21 d at 4°C. After incubation, lactic, acetic, and citric acid concentrations showed a difference among the samples due to milk type and production methods. Storage time had little effect on the organic acid values of kefir samples. As compared with cow milk kefir, buffalo milk kefir had higher numbers of microorganisms, except lactobacilli, at the end of storage. Whereas pH and titratable acidity exhibited similar changes during storage in all kefir samples, ethanol levels were significantly increased in buffalo milk kefir samples. Glutamic acid was the major amino acid at all sampling times for all samples. Tyrosine, serine, histidine, alanine, methionine, and lysine concentrations were determined to be different in all samples depending on milk type. In general, due to the higher microbial population (especially yeast), kefir made from buffalo milk may be preferred. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

The Oenological Potential of Hanseniaspora uvarum in Simultaneous and Sequential Co-fermentation with Saccharomyces cerevisiae for Industrial Wine Production

PubMed Central

Tristezza, Mariana; Tufariello, Maria; Capozzi, Vittorio; Spano, Giuseppe; Mita, Giovanni; Grieco, Francesco

2016-01-01

In oenology, the utilization of mixed starter cultures composed by Saccharomyces and non-Saccharomyces yeasts is an approach of growing importance for winemakers in order to enhance sensory quality and complexity of the final product without compromising the general quality and safety of the oenological products. In fact, several non-Saccharomyces yeasts are already commercialized as oenological starter cultures to be used in combination with Saccharomyces cerevisiae, while several others are the subject of various studies to evaluate their application. Our aim, in this study was to assess, for the first time, the oenological potential of H. uvarum in mixed cultures (co-inoculation) and sequential inoculation with S. cerevisiae for industrial wine production. Three previously characterized H. uvarum strains were separately used as multi-starter together with an autochthonous S. cerevisiae starter culture in lab-scale micro-vinification trials. On the basis of microbial development, fermentation kinetics and secondary compounds formation, the strain H. uvarum ITEM8795 was further selected and it was co- and sequentially inoculated, jointly with the S. cerevisiae starter, in a pilot scale wine production. The fermentation course and the quality of final product indicated that the co-inoculation was the better performing modality of inoculum. The above results were finally validated by performing an industrial scale vinification The mixed starter was able to successfully dominate the different stages of the fermentation process and the H. uvarum strain ITEM8795 contributed to increasing the wine organoleptic quality and to simultaneously reduce the volatile acidity. At the best of our knowledge, the present report is the first study regarding the utilization of a selected H. uvarum strain in multi-starter inoculation with S. cerevisiae for the industrial production of a wine. In addition, we demonstrated, at an industrial scale, the importance of non-Saccharomyces in

The Oenological Potential of Hanseniaspora uvarum in Simultaneous and Sequential Co-fermentation with Saccharomyces cerevisiae for Industrial Wine Production.

PubMed

Tristezza, Mariana; Tufariello, Maria; Capozzi, Vittorio; Spano, Giuseppe; Mita, Giovanni; Grieco, Francesco

2016-01-01

In oenology, the utilization of mixed starter cultures composed by Saccharomyces and non-Saccharomyces yeasts is an approach of growing importance for winemakers in order to enhance sensory quality and complexity of the final product without compromising the general quality and safety of the oenological products. In fact, several non-Saccharomyces yeasts are already commercialized as oenological starter cultures to be used in combination with Saccharomyces cerevisiae, while several others are the subject of various studies to evaluate their application. Our aim, in this study was to assess, for the first time, the oenological potential of H. uvarum in mixed cultures (co-inoculation) and sequential inoculation with S. cerevisiae for industrial wine production. Three previously characterized H. uvarum strains were separately used as multi-starter together with an autochthonous S. cerevisiae starter culture in lab-scale micro-vinification trials. On the basis of microbial development, fermentation kinetics and secondary compounds formation, the strain H. uvarum ITEM8795 was further selected and it was co- and sequentially inoculated, jointly with the S. cerevisiae starter, in a pilot scale wine production. The fermentation course and the quality of final product indicated that the co-inoculation was the better performing modality of inoculum. The above results were finally validated by performing an industrial scale vinification The mixed starter was able to successfully dominate the different stages of the fermentation process and the H. uvarum strain ITEM8795 contributed to increasing the wine organoleptic quality and to simultaneously reduce the volatile acidity. At the best of our knowledge, the present report is the first study regarding the utilization of a selected H. uvarum strain in multi-starter inoculation with S. cerevisiae for the industrial production of a wine. In addition, we demonstrated, at an industrial scale, the importance of non-Saccharomyces in

Early transcriptional response to biotic stress in mixed starter fermentations involving Saccharomyces cerevisiae and Torulaspora delbrueckii.

PubMed

Tronchoni, Jordi; Curiel, Jose Antonio; Morales, Pilar; Torres-Pérez, Rafael; Gonzalez, Ramon

2017-01-16

Advances in microbial wine biotechnology have led to the recent commercialization of several non-Saccharomyces starter cultures. These are intended to be used in either simultaneous or sequential inoculation with Saccharomyces cerevisiae. The different types of microbial interactions that can be stablished during wine fermentation acquire an increased relevance in the context of these mixed-starter fermentations. We analysed the transcriptional response to co-cultivation of S. cerevisiae and Torulaspora delbrueckii. The study focused in the initial stages of wine fermentation, before S. cerevisiae completely dominates the mixed cultures. Both species showed a clear response to the presence of each other, even though the portion of the genome showing altered transcription levels was relatively small. Changes in the transcription pattern suggested a stimulation of metabolic activity and growth, as a consequence of the presence of competitors in the same medium. The response of S. cerevisiae seems to take place earlier, as compared to T. delbrueckii. Enhanced glycolytic activity of the mixed culture was confirmed by the CO 2 production profile during these early stages of fermentation. Interestingly, HSP12 expression appeared induced by co-cultivation for both of S. cerevisiae and Torulaspora delbrueckii in the two time points studied. This might be related with a recently described role of Hsp12 in intercellular communication in yeast. Expression of S. cerevisiae PAU genes was also stimulated in mixed cultures. Copyright © 2016. Published by Elsevier B.V.

Inhibition of Listeria monocytogenes by piscicolin 126 in milk and Camembert cheese manufactured with a thermophilic starter.

PubMed

Wan, J; Harmark, K; Davidson, B E; Hillier, A J; Gordon, J B; Wilcock, A; Hickey, M W; Coventry, M J

1997-03-01

The effect of bacteriocin, piscicolin 126, on the growth of Listeria monocytogenes and cheese starter bacteria was investigated in milk and in Camembert cheese manufactured from milk challenged with 10(2) cfu ml(-1) L. monocytogenes. In milk incubated at 30 degrees C, piscicolin 126 added in the range of 512-2,048 AU ml(-1) effectively inhibited growth of L. monocytogenes for more than 20 d when challenged with approximately 10(2) cfu ml(-1) L. monocytogenes. At higher challenge levels (10(4) and 10(6) cfu ml(-1)), piscicolin 126 reduced the viable count of L. monocytogenes by 4-5 log units immediately after addition of the bacteriocin; however, growth of Listeria occurred within 24 h. The minimum inhibitory concentration (MIC) of piscicolin 126 against lactic acid cheese starter bacteria was generally greater than 204,800 AU ml(-1) , and the viable count and acid production of these starter cultures in milk were not affected by the addition of 2,048 AU ml(-1) piscicolin 126. Camembert cheeses made from milk challenged with L. monocytogenes and with added piscicolin 126 showed a viable count of L. monocytogenes 3-4 log units lower than those without piscicolin 126. Inactivation of piscicolin 126 by proteolytic enzymes from cheese starter bacteria and mould together with the emergence of piscicolin 126-resistant isolates was responsible for the recovery of L. monocytogenes in the cheeses during ripening.

Rice and soy protein isolate in pre-starter diets for broilers.

PubMed

Ebling, P D; Kessler, A M; Villanueva, A P; Pontalti, G C; Farina, G; Ribeiro, A M L

2015-11-01

Although most industries use a specific diet for the pre-starter phase, ingredients are used in the later phases, primarily corn and soybean meal, which at this stage do not have high digestibility. Three experiments : Exp : were carried out to evaluate the substitution of corn by white or parboiled rice : WR, PR : and the inclusion of 6% soy protein isolate : SPI : in pre-starter diets (1 to 7 d). In Exp 1 (1 to 21 d), WR, PR, and SPI were added to the diets until the birds were 21-day-old, whereas in Exps 2 and 3 (1 to 33 d), only until birds were 7-day-old. Birds were fed a basal diet based on corn and soybean meal until the end of the experimental period. In Exp 1, the coefficients of total tract apparent retention : CTTAR : of the pre-starter and the starter diets, ileal and jejunal digestibility of starch in the starter diets, and broiler performance were measured. Subsequently, the same pre-starter diets Exp 1 were evaluated in pellet (Exp 2) or mash (Exp 3) form and different oil percentage (Exp 2) or not (Exp 3). We hypothesized that the ingredients particle size (Exp 2) and fat content (Exp 3) could influence feed intake. There was no interaction among the evaluated factors (P > 0.05). Rice (WR or PR) promoted better results than corn in terms of CTTAR of dietary components, jejunal and ileal starch digestibility, and broiler performance (P < 0.01). In Exp 1, diets with 6% SPI presented better CTTAR, except Nitrogen ( N: ), but lower feed intake, which negatively affected broiler performance (P < 0.01). In Exps 1, 2, and 3, the inclusion of SPI did not improve broiler performance (P > 0.05), so that SPI may not be the best choice for pre-starter diets. The study also suggests that better growth performance and nutrient digestibility can be obtained in broiler chickens if corn is replaced by rice in pre-starter diets. © 2015 Poultry Science Association Inc.

Generation of food-grade lactococcal starters which produce the lantibiotics lacticin 3147 and lacticin 481.

PubMed

O'Sullivan, Lisa; Ryan, Maire P; Ross, R Paul; Hill, Colin

2003-06-01

Transconjugant lactococcal starters which produce both lantibiotics lacticin 3147 and lacticin 481 were generated via conjugation of large bacteriocin-encoding plasmids. A representative of one of the resultant strains proved more effective at killing Lactobacillus fermentum and inhibiting the growth of Listeria monocytogenes LO28H than either of the single bacteriocin-producing parental strains, demonstrating the potential of these transconjugants as protection cultures for food safety applications.

Generation of Food-Grade Lactococcal Starters Which Produce the Lantibiotics Lacticin 3147 and Lacticin 481

PubMed Central

O'Sullivan, Lisa; Ryan, Maire P.; Ross, R. Paul; Hill, Colin

2003-01-01

Transconjugant lactococcal starters which produce both lantibiotics lacticin 3147 and lacticin 481 were generated via conjugation of large bacteriocin-encoding plasmids. A representative of one of the resultant strains proved more effective at killing Lactobacillus fermentum and inhibiting the growth of Listeria monocytogenes LO28H than either of the single bacteriocin-producing parental strains, demonstrating the potential of these transconjugants as protection cultures for food safety applications. PMID:12788782

Suitability of a new mixed-strain starter for manufacturing uncooked raw ewe's milk cheeses.

PubMed

Feutry, Fabienne; Torre, Paloma; Arana, Ines; Garcia, Susana; Pérez Elortondo, Francisco J; Berthier, Françoise

2016-06-01

Most raw milk Ossau-Iraty cheeses are currently manufactured on-farm using the same commercial streptococcal-lactococcal starter (S1). One way to enhance the microbial diversity that gives raw milk its advantages for cheese-making is to formulate new starters combining diverse, characterized strains. A new starter (OI) combining 6 raw milk strains of lactococci, recently isolated and characterized, was tested in parallel with the current starter by making 12 Ossau-Iraty raw milk cheeses at 3 farmhouses under the conditions prevailing at each farm. Compliance of the sensory characteristics with those expected by the Ossau-Iraty professionals, physicochemical parameters and coliforms were quantified at key manufacturing steps. The new starter OI gave cheeses having proper compliance but having lower compliance than the S1 cheeses under most manufacturing conditions, while managing coliform levels equally well as starter S1. This lower compliance relied more on the absence of Streptococcus thermophilus in starter OI, than on the nature of the lactoccocal strains present in starter OI. The study also shows that variations in 5 technological parameters during the first day of manufacture, within the range of values applied in the 3 farmhouses, are powerful tools for diversifying the scores for the sensory characteristics investigated. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Genetic improvement of technological characteristics of starters for fermented milk products].

PubMed

Oganesian, G G; Barsegian, A A; Grigorian, N G; Toptsian, A V

2010-01-01

Possibility for improvement of technological characteristics of lactobacilli using mutations of resistance to rifampicin (rif(r)) and streptomycin (str(r)) was studied. Using starter model of Narine Lactobacillus acidophilus INMIA-9602 Armenian diet milk product, it was showed that a possibility for selecting strains with increased rate of milk fermentation and acid production is higher in Rif(r) and Str(r) mutants induced by nitrosoguanidine than in cultures sensitive to antibiotics. The milk products obtained using Rif(r) and Str(r) strains had high viscosity, improved texture, increased amount of alive cells and good organoleptic features.

Microbial ecology of sourdough fermentations: diverse or uniform?

PubMed

De Vuyst, L; Van Kerrebroeck, S; Harth, H; Huys, G; Daniel, H-M; Weckx, S

2014-02-01

Sourdough is a specific and stressful ecosystem inhabited by yeasts and lactic acid bacteria (LAB), mainly heterofermentative lactobacilli. On the basis of their inocula, three types of sourdough fermentation processes can be distinguished, namely backslopped ones, those initiated with starter cultures, and those initiated with a starter culture followed by backslopping. Typical sourdough LAB species are Lactobacillus fermentum, Lactobacillus paralimentarius, Lactobacillus plantarum, and Lactobacillus sanfranciscensis. Typical sourdough yeast species are Candida humilis, Kazachstania exigua, and Saccharomyces cerevisiae. Whereas region specificity is claimed in the case of artisan backslopped sourdoughs, no clear-cut relationship between a typical sourdough and its associated microbiota can be found, as this is dependent on the sampling, isolation, and identification procedures. Both simple and very complex consortia may occur. Moreover, a series of intrinsic and extrinsic factors may influence the composition of the sourdough microbiota. For instance, an influence of the flour (type, quality status, etc.) and the process parameters (temperature, pH, dough yield, backslopping practices, etc.) occurs. In this way, the presence of Lb. sanfranciscensis during sourdough fermentation depends on specific environmental and technological factors. Also, Triticum durum seems to select for obligately heterofermentative LAB species. Finally, there are indications that the sourdough LAB are of intestinal origin. Copyright © 2013 Elsevier Ltd. All rights reserved.

Internet starter kit update 1997

DOT National Transportation Integrated Search

1997-01-01

The Bureau of Transportation Statistics (BTS) established an Internet site in 1995, and also produced an Internet Starter Kit not only to assist transportation professionals in accessing the new Internet site but also to give them a basic overview of...

Influence of starter protein content on growth of dairy calves in an enhanced early nutrition program.

PubMed

Stamey, J A; Janovick, N A; Kertz, A F; Drackley, J K

2012-06-01

Our objectives were to determine the effect of starter crude protein (CP) content on growth of Holstein calves from birth to 10 wk of age in an enhanced early nutrition program, and to compare the enhanced program to a conventional milk replacer program. Calves (64 female, 25 male) were assigned to 3 treatments in a randomized block design: 1) conventional milk replacer (20% CP, 20% fat) plus conventional starter [19.6% CP, dry matter (DM) basis], 2) enhanced milk replacer (28.5% CP, 15% fat) plus conventional starter, and 3) enhanced milk replacer plus high-CP starter (25.5% CP, DM basis). Calves began treatments (n=29, 31, and 29 for treatments 1 to 3) at 3 d of age. Conventional milk replacer (12.5% solids) was fed at 1.25% of birth body weight (BW) as DM daily in 2 feedings from wk 1 to 5 and at 0.625% of birth BW once daily during wk 6. Enhanced milk replacer (15% solids) was fed at 1.5% of BW as DM during wk 1 and 2% of BW as DM during wk 2 to 5, divided into 2 daily feedings. During wk 6, enhanced milk replacer was fed at 1% of BW as DM once daily. Calves were weaned at d 42. Starter was available for ad libitum intake starting on d 3. Starter intake was greater for calves fed conventional milk replacer. For calves fed enhanced milk replacer, starter intake tended to be greater for calves fed enhanced starter. During the weaning period, enhanced starter promoted greater starter DM intake than the conventional starter. Over the 10-wk study, the average daily gain of BW (0.64, 0.74, and 0.80 kg/d) was greater for calves fed enhanced milk replacer with either starter and, for calves fed enhanced milk replacer, tended to be greater for calves fed high-CP starter. Rates of change in withers height, body length, and heart girth were greater for calves fed enhanced milk replacer but did not differ between starter CP concentrations. The postweaning BW for enhanced milk replacer treatments was greater for calves receiving the enhanced starter at wk 8 (73.7, 81.3, and

The effect of lactic acid bacterial starter culture and chemical additives on wilted rice straw silage.

PubMed

Wang, Yan-Su; Shi, Wei; Huang, Lin-Ting; Ding, Cheng-Long; Dai, Chuan-Chao

2016-04-01

Lactic acid bacteria (LAB) are suitable for rice straw silage fermentation, but have been studied rarely, and rice straw as raw material for ensiling is difficult because of its disadvantages, such as low nutrition for microbial activities and low abundances of natural populations of LAB. So we investigated the effect of application of LAB and chemical additives on the fermentation quality and microbial community of wilted rice straw silage. Treatment with chemical additives increased the concentrations of crude protein (CP), water soluble carbohydrate (WSC), acetic acid and lactic acid, reduced the concentrations of acid detergent fiber (ADF) and neutral detergent fiber (NDF), but did not effectively inhibit the growth of spoilage organisms. Inoculation with LABs did not improve the nutritional value of the silage because of poor growth of LABs in wilted rice straw. Inoculation with LAB and addition of chemical materials improved the quality of silage similar to the effects of addition of chemical materials alone. Growth of aerobic and facultatively anaerobic bacteria was inhibited by this mixed treatment and the LAB gradually dominated the microbial community. In summary, the fermentation quality of wilted rice straw silage had improved by addition of LAB and chemical materials. © 2015 Japanese Society of Animal Science.

Phenotypic and genotypic diversity of dominant lactic acid bacteria isolated from traditional yoghurts produced by tribes of Iran

PubMed Central

RoushanZadeh, S; Eskandari, M. H.; Shekarforoush, S. S.; Hosseini, A

2014-01-01

Morphological, biochemical and molecular characteristics were studied to identify dominant lactic acid bacteria (LAB), isolated from traditional yoghurts produced by tribes of Iran. From 60 yoghurt samples, a total of 137 LAB isolates were determined, in which 66 and 71 were identified as lactic acid cocci and bacilli, respectively. Biochemical tests showed the occurrence of 9.76% mesophilic homofermentative, 10.98% mesophilic hetrofermentative, 26.83% thermophilic homofermentative and 47.56% mesophilic homofermentative cocci. As for lactic acid bacilli, mesophilic facultative hetrofermentative (26%); thermophilic obligate homofermentative (56%); mesophilic obligate hetrofermentative (18%) were found. Genetically the presence of the following species were verified: E. faecium; E. faecalis; E. durans; L. lactis subsp. lactis; St. thermophilus; Lb. delbruecki subsp. bulgaricus; Lb. brevis; Lb. diolivorans; Lb. helveticus; Lb. jensenii; Lb. plantarum. 9% of the Lactobacillus isolates showed incompatible results between phenotypic and genotypic characteristics. From the cocci isolates, 38.46% showed identical results between phylogenetic characteristics. The current study constitutes the first step in the designing process of LAB starter cultures, to protect the typical organoleptic characteristics of traditional yoghurt. The results could also be used to introduce new starter cultures for commercial use. PMID:27175129

Effect of starter culture and turmeric on physico-chemical quality of carabeef pastirma.

PubMed

Maurya, P; Borpuzari, R N; Nath, D R; Nath, N C

2010-01-01

Carabeef samples were sliced, pressed, cured and divided into 6 groups. Starter cultures (Micrococcus varians M483 (MV), Staphylococcus carnosus (SC), Lactobacillus sakei (LS), M. varians M483+ Lb. sakei and Staph. carnosus + Lb. sakei) were inoculated at the dose of 10(6)-0(7)cfu/g and stored at 10 ± 1°C for 7 days. Uninoculated samples were maintained as control. Samples were then divided into 2 treatment groups. Samples of treatment 1 (T1) were smeared with a paste of turmeric followed by application of a thick layer of the paste of garlic, cumin, black pepper and red pepper whereas, samples of treatment 2 (T2) were applied with a thick layer of spices as above without turmeric. With the gradual fall in pH there was a reduction in water-holding capacity (WHC) of samples. The WHC of samples treated with SC+LS of T1 reduced to 6.3 ± 0.03 cm(2) and those inoculated with MV+LS of T2 to 6.2 ± 0.03 cm(2). The extract release volume (ERV) increased in all samples during storage. The least ERV of 11.7 and 11.6 ml were recorded in samples inoculated with MV of T1 and T2, respectively. The tyrosine (TV) and thiobarbituric acid (TBA) number of turmeric treated samples were significantly lower than non turmeric treated samples. The samples inoculated with LS had the least TV of 30.9 mg tyrosine/100 g of meat and TBA number of 0.06 mg manoladehyde/kg of meat. Samples inoculated with MV and LS of both T1 and T2 were better in physico-chemical qualities.

Fiber sources for complete calf starter rations.

PubMed

Murdock, F R; Wallenius, R W

1980-11-01

Complete calf starter rations containing either 1) alfalfa hay, 2) cottonseed hulls, or 3) alfalfa-beet pulp as sources of fiber were fed to Holstein heifer calves at two locations on a limited milk program from 3 days to 12 wk of age. Rations were isonitrogenous and similar in content of crude fiber and acid detergent fiber. Although growth and development were normal on all rations, calves fed the cottonseed hull ration consumed more starter and gained more body weight than calves fed the other sources of fiber. The similarity of feed efficiencies, rumen pH, and molar ratios of volatile fatty acids between rations indicated no appreciable differences in rumen development or function. The growth response of calves fed the cottonseed hull ration appeared to be a result of better ration acceptability for which no reason was evident. Calves raised at Puyallup gained more body weight than calves at Pullman, and these gains were made more efficiently. These location effects may be related to seasonal differences and greater demands for production of body heat. Although the incidence of scours was less for calves fed alfalfa hay starter, the incidence and severity of bloat were higher for that ration.

Compromised Lactobacillus helveticus starter activity in the presence of facultative heterofermentative Lactobacillus casei DPC6987 results in atypical eye formation in Swiss-type cheese.

PubMed

O'Sullivan, Daniel J; McSweeney, Paul L H; Cotter, Paul D; Giblin, Linda; Sheehan, Jeremiah J

2016-04-01

Nonstarter lactic acid bacteria are commonly implicated in undesirable gas formation in several varieties, including Cheddar, Dutch-, and Swiss-type cheeses, primarily due to their ability to ferment a wide variety of substrates. This effect can be magnified due to factors that detrimentally affect the composition or activity of starter bacteria, resulting in the presence of greater than normal amounts of fermentable carbohydrates and citrate. The objective of this study was to determine the potential for a facultatively heterofermentative Lactobacillus (Lactobacillus casei DPC6987) isolated from a cheese plant environment to promote gas defects in the event of compromised starter activity. A Swiss-type cheese was manufactured, at pilot scale and in triplicate, containing a typical starter culture (Streptococcus thermophilus and Lactobacillus helveticus) together with propionic acid bacteria. Lactobacillus helveticus populations were omitted in certain vats to mimic starter failure. Lactobacillus casei DPC6987 was added to each experimental vat at 4 log cfu/g. Cheese compositional analysis and X-ray computed tomography revealed that the failure of starter bacteria, in this case L. helveticus, coupled with the presence of a faculatively heterofermentative Lactobacillus (L. casei) led to excessive eye formation during ripening. The availability of excess amounts of lactose, galactose, and citrate during the initial ripening stages likely provided the heterofermentative L. casei with sufficient substrates for gas formation. The accrual of these fermentable substrates was notable in cheeses lacking the L. helveticus starter population. The results of this study are commercially relevant, as they demonstrate the importance of viability of starter populations and the control of specific nonstarter lactic acid bacteria to ensure appropriate eye formation in Swiss-type cheese. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights

Microbial diversity and chemical analysis of the starters used in traditional Chinese sweet rice wine.

PubMed

Cai, Haiying; Zhang, Ting; Zhang, Qi; Luo, Jie; Cai, Chenggang; Mao, Jianwei

2018-08-01

Chinese sweet rice wine (CSRW) is a popular alcoholic drink in China. To investigate the effect of the microbial composition in CSRW starters on the final quality of the alcoholic drink, high-throughput sequencing on the fungal internal transcribed spacer II and bacterial 16S rRNA gene of the microflora in 8 starter samples was performed. The sequencing data analysis showed that 10 genera of yeasts and mold, and 11 genera of bacteria were identified. Fungal diversity analyses showed the significant variances in the fungal compositions among the starter samples. Starter microbiota were dominated by the Rhizopus genus in SZ5, LS6, NN8, QD9, DZ10 and DZ11, indicating its important role in starch hydrolysis during CSRW brewing. According to principal coordinate analyses, the bacterial composition had even less similarity among the 8 starter samples. The chemical determination of CSRW fermented with the 8 starters demonstrated that the CSRW quality and flavor were drastically influenced by the taxonomic composition and metabolism of the microbes in the starters. This study suggests it is necessary to standardize rice wine manufacturing and flavor classification by specifying starter and fermentation techniques. Copyright © 2018 Elsevier Ltd. All rights reserved.

Impact and Effectiveness of a Stand-Alone NRT Starter Kit in a Statewide Tobacco Cessation Program.

PubMed

Kerr, Amy N; Schillo, Barbara A; Keller, Paula A; Lachter, Randi B; Lien, Rebecca K; Zook, Heather G

2018-01-01

To examine 2-week nicotine replacement therapy (NRT) starter kit quit outcomes and predictors and the impact of adding this new service on treatment reach. Observational study of a 1-year cohort of QUITPLAN Services enrollees using registration and utilization data and follow-up outcome survey data of a subset of enrollees who received NRT starter kits. ClearWay Minnesota's QUITPLAN Services provides a quit line that is available to uninsured and underinsured Minnesotans and NRT starter kits (a free 2-week supply of patches, gum, or lozenges) that are available to all Minnesota tobacco users. A total of 15 536 adult QUITPLAN Services enrollees and 818 seven-month follow-up survey NRT starter kit respondents. Treatment reach for all services and tobacco quit outcomes and predictors for starter kit recipients. Descriptive analyses, χ 2 analyses, and logistic regression. Treatment reach increased 3-fold after adding the 2-week NRT starter kit service option to QUITPLAN Services compared to the prior year (1.86% vs 0.59%). Among all participants enrolling in QUITPLAN services during a 1-year period, 83.8% (13 026/15 536) registered for a starter kit. Among starter kit respondents, 25.6% reported being quit for 30 days at the 7-month follow-up. After controlling for other factors, using all NRT and selecting more cessation services predicted quitting. An NRT starter kit brought more tobacco users to QUITPLAN services, demonstrating interest in cessation services separate from phone counseling. The starter kit produced high quit rates, comparable to the quit line in the same time period. Cessation service providers may want to consider introducing starter kits to reach more tobacco users and ultimately improve population health.

Immunomodulation properties of multi-species fermented milks.

PubMed

Foligné, Benoît; Parayre, Sandrine; Cheddani, Redouane; Famelart, Marie-Hélène; Madec, Marie-Noëlle; Plé, Coline; Breton, Jérôme; Dewulf, Joëlle; Jan, Gwénaël; Deutsch, Stéphanie-Marie

2016-02-01

Dairy propionibacteria (PAB) are used as a ripening starter in combination with Lactic acid bacteria (LAB) for dairy products such as Swiss-type cheese. LAB and PAB have also been studied for their probiotic properties but little is still known about their individual and/or synergistic beneficial effects within dairy matrices. In the context of a rising incidence of Inflammatory Bowel Diseases, it has become crucial to evaluate the immunomodulatory potential of bacteria ingested in large numbers via dairy products. We therefore selected different strains and combinations of technological LAB and PAB. We determined their immunomodulatory potential by IL-10 and IL-12 induction, in human peripheral blood mononuclear cells, on either single or mixed cultures, grown on laboratory medium or directly in milk. Milk was fermented with selected anti-inflammatory strains of LAB or PAB/LAB mixed cultures and the resulting bacterial fractions were also evaluated for these properties, together with starter viability and optimum technological aspects. The most promising fermented milks were evaluated in the context of TNBS- or DSS-induced colitis in mice. The improvement in inflammatory parameters evidenced an alleviation of colitis symptoms as a result of fermented milk consumption. This effect was clearly strain-dependent and modulated by growth within a fermented dairy product. These findings offer new tools and perspectives for the development of immunomodulatory fermented dairy products for targeted populations. Copyright © 2015 Elsevier Ltd. All rights reserved.

Development of a flow cytometric method to analyze subpopulations of bacteria in probiotic products and dairy starters.

PubMed

Bunthof, Christine J; Abee, Tjakko

2002-06-01

Flow cytometry (FCM) is a rapid and sensitive technique that can determine cell numbers and measure various physiological characteristics of individual cells by using appropriate fluorescent probes. Previously, we developed an FCM assay with the viability probes carboxyfluorescein diacetate (cFDA) and TOTO-1 [1'-(4,4,7,7-tetramethyl-4,7-diazaundecamethylene)-bis-4-[3-methyl-2,3dihydro(benzo-1,3-oxazole)-2-methylidene]-1-(3'-trimethylammoniumpropyl)-pyridinium tetraiodide] for (stressed) lactic acid bacteria (C. J. Bunthof, K. Bloemen, P. Breeuwer, F. M. Rombouts, and T. Abee, Appl. Environ. Microbiol. 67:2326-2335, 2001). cFDA stains intact cells with enzymatic activity, and TOTO-1 stains membrane-permeabilized cells. Here we used this assay to study the viability of bacterial suspensions in milk, dairy fermentation starters, and probiotic products. To facilitate FCM analysis of bacteria in milk, a commercially available milk-clearing solution was used. The procedure was optimized to increase the signal-to-noise ratio. FCM enumerations were accurate down to a concentration of 10(5) cells ml(-1). The level of retrieval of Lactobacillus plantarum WCFS 1 suspended in milk was high, and viability was not affected by the procedure. The plate counts for cleared samples of untreated cell suspensions were nearly as high as the total FCM counts, and the correlation was strong (r > 0.99). In dairy fermentation starters and in probiotic products the FCM total cell counts were substantially higher than the numbers of CFU. Three functional populations could be distinguished: culturable cells, cells that are intact and metabolically active but not culturable, and permeabilized cells. The proportions of the populations differed in the products tested. This FCM method provides tools to assess the functionality of different populations in fermentation starters and probiotic products.

Development of a Flow Cytometric Method To Analyze Subpopulations of Bacteria in Probiotic Products and Dairy Starters

PubMed Central

Bunthof, Christine J.; Abee, Tjakko

2002-01-01

Flow cytometry (FCM) is a rapid and sensitive technique that can determine cell numbers and measure various physiological characteristics of individual cells by using appropriate fluorescent probes. Previously, we developed an FCM assay with the viability probes carboxyfluorescein diacetate (cFDA) and TOTO-1 {1′-(4,4,7,7-tetramethyl-4,7-diazaundecamethylene)-bis-4-[3-methyl-2,3dihydro(benzo-1,3-oxazole)-2-methylidene]-1-(3′-trimethylammoniumpropyl)-pyridinium tetraiodide} for (stressed) lactic acid bacteria (C. J. Bunthof, K. Bloemen, P. Breeuwer, F. M. Rombouts, and T. Abee, Appl. Environ. Microbiol. 67:2326-2335, 2001). cFDA stains intact cells with enzymatic activity, and TOTO-1 stains membrane-permeabilized cells. Here we used this assay to study the viability of bacterial suspensions in milk, dairy fermentation starters, and probiotic products. To facilitate FCM analysis of bacteria in milk, a commercially available milk-clearing solution was used. The procedure was optimized to increase the signal-to-noise ratio. FCM enumerations were accurate down to a concentration of 105 cells ml−1. The level of retrieval of Lactobacillus plantarum WCFS 1 suspended in milk was high, and viability was not affected by the procedure. The plate counts for cleared samples of untreated cell suspensions were nearly as high as the total FCM counts, and the correlation was strong (r > 0.99). In dairy fermentation starters and in probiotic products the FCM total cell counts were substantially higher than the numbers of CFU. Three functional populations could be distinguished: culturable cells, cells that are intact and metabolically active but not culturable, and permeabilized cells. The proportions of the populations differed in the products tested. This FCM method provides tools to assess the functionality of different populations in fermentation starters and probiotic products. PMID:12039752

Effect of macronutrient ratio of the pre-starter diet on broiler performance and intermediary metabolism.

PubMed

Swennen, Q; Everaert, N; Debonne, M; Verbaeys, I; Careghi, C; Tona, K; Janssens, G P J; Decuypere, E; Bruggeman, V; Buyse, J

2010-06-01

The aim of this study was to investigate the influence of isoenergetic substitution between the three energy delivering macronutrients in pre-starter diets on performance and intermediary nutrient metabolism in broiler chickens. From hatch until 5 days of age, 600 chicks, collected during peak of hatch, were fed one of the three experimental pre-starter diets with isoenergetic (13 MJ metabolisable energy/kg) substitutions between fat (43 vs. 108 g/kg), protein (126 vs. 240 g/kg) and carbohydrates (391 vs. 510 g/kg). After 5 days, commercial grower and finisher diets were provided. Pre-starter composition influenced body weight until slaughter age, although not statistically verifiable. Broilers fed the low protein (LP) pre-starter had the lowest body weight in relation to chickens on the low carbohydrate or low fat pre-starter diet. After hatch, chicks on the LP pre-starter diet were able to use the residual yolk sac more rapidly to fulfil their protein requirement, which is reflected in small intestine and liver development. Also, plasma metabolite levels were influenced mostly by the LP pre-starter, indicating that the main focus for the requirements of newly hatched chicks should be on proteins. Furthermore, optimal nutrition during the first day's post-hatch should take into account the contribution of the yolk.

Evaluation of different PCR primers for denaturing gradient gel electrophoresis (DGGE) analysis of fungal community structure in traditional fermentation starters used for Hong Qu glutinous rice wine.

PubMed

Lv, Xu-Cong; Jiang, Ya-Jun; Liu, Jie; Guo, Wei-Ling; Liu, Zhi-Bin; Zhang, Wen; Rao, Ping-Fan; Ni, Li

2017-08-16

Denaturing gradient gel electrophoresis (DGGE) has become a widely used tool to examine microbial community structure. However, when DGGE is applied to evaluate the fungal community of traditional fermentation starters, the choice of hypervariable ribosomal RNA gene regions is still controversial. In the current study, several previously published fungal PCR primer sets were compared and evaluated using PCR-DGGE, with the purpose of screening a suitable primer set to study the fungal community of traditional fermentation starters for Hong Qu glutinous rice wine. Firstly, different primer sets were used to amplify different hypervariable regions from pure fungal cultures. Except NS1/FR1+ and ITS1fGC/ITS4, other primer sets (NL1+/LS2R, NL3A/NL4GC, FF390/FR1+, NS1/GCFung, NS3+/YM951r and ITS1fGC/ITS2r) amplified the target DNA sequences successfully. Secondly, the selected primer sets were further evaluated based on their resolution to distinguish different fungal cultures through DGGE fingerprints. Three primer sets (NL1+/LS2R, NS1/GCFung and ITS1fGC/ITS2r) were finally selected for investigating the fungal community structure of different traditional fermentation starters for Hong Qu glutinous rice wine. The internal transcribed spacer (ITS) region amplified by ITS1fGC/ITS2r, which is more hypervariable than the 18S rRNA gene and 26S rRNA gene, provides an excellent tool to separate amplification products of different fungal species. Results indicated that PCR-DGGE profile using ITS1fGC/ITS2r showed more abundant fungal species than that using NL1+/LS2R and NS1/GCFung. Therefore, ITS1fGC/ITS2r is the most suitable primer set for PCR-DGGE analysis of fungal community structure in traditional fermentation starters for Hong Qu glutinous rice wine. DGGE profiles based on ITS1fGC/ITS2r revealed the presence of twenty-four fungal species in traditional fermentation starter. A significant difference of fungal community can be observed directly from DGGE fingerprints and

Evaluation of Zygosaccharomyces bailii BCV 08 as a co-starter in wine fermentation for the improvement of ethyl esters production.

PubMed

Garavaglia, Juliano; Schneider, Rosana de Cassia de Souza; Camargo Mendes, Sandra Denise; Welke, Juliane Elisa; Zini, Cláudia Alcaraz; Caramão, Elina Bastos; Valente, Patrícia

2015-04-01

Zygosaccharomyces bailii BCV 08, a yeast isolated from red wine barrels in Brazil, was evaluated as co-starter in fermentations with Saccharomyces cerevisiae. Z. bailii BCV 08 was preliminarily shown to produce high levels of esters, and the production was optimized in bench and bioreactor scales using grape must. White wine vinifications were conducted with mixed cultures containing different proportions of Z. bailii BCV 08 and an enological strain of S. cerevisiae. In all trials that contained Z. bailii BCV 08, the production of ethyl esters was enhanced in comparison to the vinification control. Our results clearly show the potential of Z. bailii BCV 08 as a mixed starter with S. cerevisiae in order to increase the aromatic complexity of wine. Copyright © 2015. Published by Elsevier GmbH.

Antibiotic resistance of lactic acid bacteria isolated from dry-fermented sausages.

PubMed

Fraqueza, Maria João

2015-11-06

Dry-fermented sausages are meat products highly valued by many consumers. Manufacturing process involves fermentation driven by natural microbiota or intentionally added starter cultures and further drying. The most relevant fermentative microbiota is lactic acid bacteria (LAB) such as Lactobacillus, Pediococcus and Enterococcus, producing mainly lactate and contributing to product preservation. The great diversity of LAB in dry-fermented sausages is linked to manufacturing practices. Indigenous starters development is considered to be a very promising field, because it allows for high sanitary and sensorial quality of sausage production. LAB have a long history of safe use in fermented food, however, since they are present in human gastrointestinal tract, and are also intentionally added to the diet, concerns have been raised about the antimicrobial resistance in these beneficial bacteria. In fact, the food chain has been recognized as one of the key routes of antimicrobial resistance transmission from animal to human bacterial populations. The World Health Organization 2014 report on global surveillance of antimicrobial resistance reveals that this issue is no longer a future prediction, since evidences establish a link between the antimicrobial drugs use in food-producing animals and the emergence of resistance among common pathogens. This poses a risk to the treatment of nosocomial and community-acquired infections. This review describes the possible sources and transmission routes of antibiotic resistant LAB of dry-fermented sausages, presenting LAB antibiotic resistance profile and related genetic determinants. Whenever LAB are used as starters in dry-fermented sausages processing, safety concerns regarding antimicrobial resistance should be addressed since antibiotic resistant genes could be mobilized and transferred to other bacteria. Copyright © 2015 Elsevier B.V. All rights reserved.

Interaction between the physical forms of starter and forage source on growth performance and blood metabolites of Holstein dairy calves.

PubMed

Omidi-Mirzaei, H; Azarfar, A; Kiani, A; Mirzaei, M; Ghaffari, M H

2018-04-11

The objective of this study was to investigate the effects of the physical forms of starter and forage sources on feed intake, growth performance, rumen pH, and blood metabolites of dairy calves. Forty male Holstein calves (41.3 ± 3.5 kg of body weight) were used (n = 10 calves per treatment) in a 2 × 2 factorial arrangement of treatments with the factors being physical forms of starter (coarse mash and texturized) and forage source [alfalfa hay (AH) and wheat straw (WS)]. Individually housed calves were randomly assigned to 1 of the 4 dietary treatments, including (1) coarsely mashed (CM; coarse ground grains combined with a mash supplement) starter feed with AH (CM-AH), (2) coarsely mashed starter feed with WS (CM-WS), (3) texturized feed starter (TF; includes steam-flaked corn, steam-rolled barley combined with a pelleted supplement) with AH (TF-AH), and (4) TF with WS (TF-WS). Both starters had the same ingredients and nutrient compositions but differed in their physical forms. Calves were weaned on d 56 and remained in the study until d 70. All calves had free access to drinking water and the starter feeding at all times. No interaction was detected between the physical forms of starter feeds and forage source concerning starter intake, dry matter intake, metabolizable energy (ME) intake, average daily gain (ADG)/ME intake, ADG, and feed efficiency (FE). The preweaning and overall starter feed intake, dry matter intake, and ME intake were greater for calves fed TF starter diets than those fed CM starter diets. The ADG/ME intake was greater for calves fed TF starter diets than that fed CM starter. The FE was greater for calves fed TF starter diets compared with those fed CM starter during the preweaning, postweaning, and overall periods. The WS improved FE during the postweaning period compared with AH. The physical form of starter, forage source, and their interaction did not affect plasma glucose, triglycerides, and very low-density lipoprotein

Strategies to select yeast starters cultures for production of flavor compounds in cachaça fermentations.

PubMed

de Souza, Anderson Proust Gonçalves; Vicente, Maristela de Araújo; Klein, Raphael Contelli; Fietto, Luciano Gomes; Coutrim, Maurício Xavier; de Cássia Franco Afonso, Robson José; Araújo, Leandro Dias; da Silva, Paulo Henrique Alves; Bouillet, Leoneide Erica Maduro; Castro, Ieso Miranda; Brandão, Rogelio Lopes

2012-02-01

In this work, we have used classical genetics techniques to find improved starter strains to produce cachaça with superior sensorial quality. Our strategy included the selection of yeast strains resistant to 5,5',5″-trifluor-D: ,L: -leucine (TLF) and cerulenin, since these strains produce higher levels of higher alcohols and esters than parental strains. However, no clear relationship was observed when levels of flavoring compounds were compared with the levels expression of the genes (BAT1, BAT2, ATF2, EEB1 genes) involved with the biosynthesis of flavoring compounds. Furthermore, we determined the stability of phenotypes considered as the best indicators of the quality of the cachaça for a parental strain and its segregants. By applying the principal component analysis, a cluster of segregants, showing a high number of characteristics similar to the parental strain, was recognized. One segregant, that was resistant to TLF and cerulenin, also showed growth stability after six consecutive replications on plates containing high concentrations of sugar and ethanol. "Cachaça" produced at laboratory scale using a parental strain and this segregant showed a higher level of flavoring compounds. Both strains predominated in an open fermentative process through seven cycles, as was shown by mitochondrial restriction fragment length polymorphisms analysis. Based on the physical chemical composition of the obtained products, the results demonstrate the usefulness of the developed strategies for the selection of yeast strains to be used as starters in "cachaça" production.

Monitoring of the microbiota profile in nukadoko, a naturally fermented rice bran bed for pickling vegetables.

PubMed

Ono, Hiroshi; Nishio, Shoko; Tsurii, Jun; Kawamoto, Tetsuhiro; Sonomoto, Kenji; Nakayama, Jiro

2014-11-01

Nukadoko is a fermented rice bran mash traditionally used for pickling vegetables in Japan. To date, the production of both homemade and commercial nukadoko depends on natural fermentation without using starter cultures. Here, we monitored chemical and microbiological changes in the initial batch fermentation of nukadoko. Nukadoko samples were prepared by spontaneous fermentation of four different brands of rice bran, and microbiome dynamics were analyzed for 2 months. In the first week, non-Lactobacillales lactic acid bacteria (LAB) species, which differed among the samples, grew proportionally to pH decrease and lactate increase. Thereafter, Lactobacillus plantarum started growing and consumed residual sugars, causing further lactate increase in nukadoko. Finally, microbial communities in all tested nukadoko samples were dominated by L. plantarum. Taken together, our results suggest that the mixture of the fast-growing LAB species and slow-growing L. plantarum may be used as a suitable starter culture to promote the initial fermentation of nukadoko. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

The flame characteristics of the biogas has produced through the digester method with various starters

NASA Astrophysics Data System (ADS)

Ketut, Caturwati Ni; Agung, Sudrajat; Mekro, Permana; Heri, Haryanto; Bachtiar

2018-01-01

Increasing the volume of waste, especially in urban areas is a source of problems in realizing the comfort and health of the environment. It needs to do a good handling of garbage so as to provide benefits for the whole community. Organic waste processing through bio-digester method to produce a biogas as an energy source is an effort. This research was conducted to test the characteristics of biogas flame generated from organic waste processing through digester with various of the starter such as: cow dung, goat manure, and leachate that obtained from the landfill at Bagendung-Cilegon. The flame height and maximum temperature of the flame are measured for the same pressure of biogas. The measurements showed the flame produced by bio-digester with leachate starter has the lowest flame height compared to the other types of biogas, and the highest flame height is given by biogas from digester with cow dung as a starter. The maximum flame temperature of biogas produced by leachate as a starter reaches 1027 °C. This value is 7% lower than the maximum flame temperature of biogas produced by cow dung as a starter. Cow dung was observed to be the best starter compared to goat manure and leachate, but the use of leachate as a starter in producing biogas with biodigester method is not the best but it worked.

Genetics of Lactic Acid Bacteria

NASA Astrophysics Data System (ADS)

Zagorec, Monique; Anba-Mondoloni, Jamila; Coq, Anne-Marie Crutz-Le; Champomier-Vergès, Marie-Christine

Many meat (or fish) products, obtained by the fermentation of meat originating from various animals by the flora that naturally contaminates it, are part of the human diet since millenaries. Historically, the use of bacteria as starters for the fermentation of meat, to produce dry sausages, was thus performed empirically through the endogenous micro-biota, then, by a volunteer addition of starters, often performed by back-slopping, without knowing precisely the microbial species involved. It is only since about 50 years that well defined bacterial cultures have been used as starters for the fermentation of dry sausages. Nowadays, the indigenous micro-biota of fermented meat products is well identified, and the literature is rich of reports on the identification of lactic acid bacteria (LAB) present in many traditional fermented products from various geographical origin, obtained without the addition of commercial starters (See Talon, Leroy, & Lebert, 2007, and references therein).

Genome Sequence of Lactobacillus plantarum 19L3, a Strain Proposed as a Starter Culture for Slovenská Bryndza Ovine Cheese

PubMed Central

Džunková, Mária; Moya, Andrés; Tomáška, Martin; Kološta, Miroslav; Kmet, Vladimir

2014-01-01

The genome sequence of Lactobacillus plantarum isolated from ovine cheese is presented here. This bacterium is proposed as a starter strain, named 19L3, for Slovenská bryndza cheese, a traditional Slovak cheese fulfilling European Food Safety Authority (EFSA) requirements. PMID:24762933

Advanced LabVIEW Labs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, Eric D.

1999-06-17

In the world of computer-based data acquisition and control, the graphical interface program LabVIEW from National Instruments is so ubiquitous that in many ways it has almost become the laboratory standard. To date, there have been approximately fifteen books concerning LabVIEW, but Professor Essick's treatise takes on a completely different tack than all of the previous discussions. In the more standard treatments of the ways and wherefores of LabVIEW such as LabVIEW Graphical Programming: Practical Applications in Instrumentation and Control by Gary W. Johnson (McGraw Hill, NY 1997), the emphasis has been instructing the reader how to program LabVIEW tomore » create a Virtual Instrument (VI) on the computer for interfacing to a particular instruments. LabVIEW is written in G a graphical programming language developed by National Instruments. In the past the emphasis has been on training the experimenter to learn G . Without going into details here, G incorporates the usual loops, arithmetic expressions, etc., found in many programming languages, but in an icon (graphical) environment. The net result being that LabVIEW contains all of the standard methods needed for interfacing to instruments, data acquisition, data analysis, graphics, and also methodology to incorporate programs written in other languages into LabVIEW. Historically, according to Professor Essick, he developed a series of experiments for an upper division laboratory course for computer-based instrumentation. His observation was that while many students had the necessary background in computer programming languages, there were students who had virtually no concept about writing a computer program let alone a computer- based interfacing program. Thus the beginnings of a concept for not only teaching computer- based instrumentation techniques, but aiso a method for the beginner to experience writing a com- puter program. Professor Essick saw LabVIEW as the perfect environment in which to teach

Advanced LabVIEW Labs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, Eric D.

1999-06-17

In the world of computer-based data acquisition and control, the graphical interface program LabVIEW from National Instruments is so ubiquitous that in many ways it has almost become the laboratory standard. To date, there have been approximately fifteen books concerning LabVIEW, but Professor Essick's treatise takes on a completely different tack than all of the previous discussions. In the more standard treatments of the ways and wherefores of LabVIEW such as LabVIEW Graphical Programming: Practical Applications in Instrumentation and Control by Gary W. Johnson (McGraw Hill, NY 1997), the emphasis has been instructing the reader how to program LabVIEW tomore » create a Virtual Instrument (VI) on the computer for interfacing to a particular instruments. LabVIEW is written in "G" a graphical programming language developed by National Instruments. In the past the emphasis has been on training the experimenter to learn "G". Without going into details here, "G" incorporates the usual loops, arithmetic expressions, etc., found in many programming languages, but in an icon (graphical) environment. The net result being that LabVIEW contains all of the standard methods needed for interfacing to instruments, data acquisition, data analysis, graphics, and also methodology to incorporate programs written in other languages into LabVIEW. Historically, according to Professor Essick, he developed a series of experiments for an upper division laboratory course for computer-based instrumentation. His observation was that while many students had the necessary background in computer programming languages, there were students who had virtually no concept about writing a computer program let alone a computer- based interfacing program. Thus the beginnings of a concept for not only teaching computer- based instrumentation techniques, but aiso a method for the beginner to experience writing a com- puter program. Professor Essick saw LabVIEW as the "perfect environment in which to

Survival of Escherichia coli O157:H7 during manufacture and storage of white brined cheese.

PubMed

Osaili, Tareq M; Al-Nabulsi, Anas A; Olaimat, Amin N; Shaker, Reyad R; Taha, Mohammad; Holley, Richard A

2014-09-01

Escherichia coli O157:H7 is a major foodborne pathogen that causes severe disease in humans. Survival of E. coli O157:H7 during processing and storage of white brined cheese was investigated. Cheeses were prepared using pasteurized milk inoculated with a 4 strain E. coli O157:H7 cocktail (7 log(10) CFU/g) with or without yogurt starter culture (Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus salivarius ssp. thermophilus) and stored in 10% or 15% NaCl brine at 10 and 21 ºC for 28 d. NaCl concentration, water activity (a(w)), pH, and numbers of E. coli O157:H7 and lactic acid bacteria (LAB) were determined in cheese and brine. E. coli O157:H7 was able to survive in cheese stored in both brines at 10 and 21 ºC regardless of the presence of starter LAB, although the latter significantly enhanced E. coli O157:H7 reduction in cheese or its brine at 10 ºC. E. coli O157:H7 numbers were reduced by 2.6 and 3.4 log(10) CFU/g in cheese stored in 10% and 15% NaCl brine, respectively, in the presence of starter LAB and by 1.4 and 2.3 log(10) CFU/g, respectively, in the absence of starter LAB at 10 ºC. The pathogen survived, but at lower numbers in the brines. The salt concentration of cheese stored in 10% brine remained about 5% during ripening, but in 15% brine, the NaCl level increased 1.6% to 8.1% (w/w) by 28 d. Values of pH and a(w) slightly decreased 1 d after exposure to brine and reached 5.5 to 6.6 and 0.88 to 0.94, respectively, in all treatments. © 2014 Institute of Food Technologists®

Application of autochthonous mixed starter for controlled Kedong sufu fermentation in pilot plant tests.

PubMed

Feng, Zhen; Xu, Miao; Zhai, Shuang; Chen, Hong; Li, Ai-li; Lv, Xin-tong; Deng, Hong-ling

2015-01-01

Traditional sufu is fermented by back-slopping and back-slopping has many defects. The objective of this study was to apply autochthonous mixed starter to control Kedong sufu fermentation. Sufu was manufactured using back-slopping (batch A) and autochthonous mixed starter (batch B) with Kocuria kristinae F7, Micrococcus luteus KDF1, and Staphylococcus carnosus KDFR1676. Considering physicochemical properties of sufu, 150-day sufu samples from batch A and 90-day sufu samples from batch B met the standard requirements, respectively. Considering sensory characteristics of sufu, 150-day sufu samples from batch A and 90-day sufu samples from batch B showed no significant differences (P > 0.05). The maturation period of sufu was shortened by 60 d. Profiles of free amino acids and peptides partly revealed the mechanism of typical sensory quality and shorter ripening time of sufu manufactured by autochthonous mixed starter. In final products, content of total biogenic amines was reduced by 48%. Autochthonous mixed starter performed better than back-slopping. Fermentation had a positive influence on the quality, safety, and sensory properties of sufu. The application of autochthonous mixed starter does not change the sensory characteristics of traditional fermented sufu. In addition, it reduces maturation period and improves their homogeneity and safety. It is possible to substitute autochthonous mixed starter for back-slopping in the manufacture of sufu. © 2014 Institute of Food Technologists®

Interaction between the physical form of the starter feed and straw provision on growth performance of Holstein calves.

PubMed

Terré, M; Castells, Ll; Khan, M A; Bach, A

2015-02-01

Two experiments were conducted to assess the effect of physical form of a starter feed with or without straw supplementation on growth performance of Holstein calves. In experiment 1, a total of 32 calves were randomly assigned at 7 d of age to texturized starter feed (containing rolled barley, corn, and oats) without straw, texturized starter feed with chopped straw, and pelleted starter feed with chopped straw. All calves were offered 4 L of pasteurized whole milk twice daily from 7 to 35 d of age, 2 L of milk twice daily from 36 to 42 d of age, and 2 L of milk from 43 to 49 d of age. Animals were weaned at 50 d of age, and the study finished when calves were 63 d old. In experiment 2, a total of 60 calves (8 d of age) were randomly assigned to texturized starter feed (containing whole corn) without straw, pelleted starter feed without straw, and pelleted starter feed with chopped straw. All calves were offered the same milk replacer (MR; 23% crude protein and 19.5 fat) at 11% dry matter concentration, 4 L/d of MR until 14 d of age, 6 L/d of MR from 14 to 37 d, 3 L/d of MR from 38 to 44 d, and 1.5 L/d of MR from 45 to 52 d of age. The experiment finished when calves were 58 d old (1 wk after weaning). Rumen liquid pH was measured after weaning. In both studies, calves were individually housed in pens on sawdust bedding and starter feed and chopped straw were offered free choice in separate buckets. In experiment 1, starter feed and straw intake and growth did not differ among treatments. However, calves receiving straw showed a greater rumen pH compared with those not receiving straw. In experiment 2, pelleted started feed supplemented with straw fostered an increase in solid feed intake (as percentage of body weight) compared with a pelleted or texturized starter feed without straw supplementation. However, calves that received the texturized starter feed containing whole corn had rumen pH similar to those fed a pelleted starter feed with straw. Feeding a

7 CFR 58.331 - Starter distillate.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Specifications for Dairy Plants Approved for USDA Inspection and Grading Service 1 Quality Specifications for Raw Material § 58.331 Starter distillate. The refined flavor components when used to flavor butter and related products. It shall be of food grade quality, free of extraneous material and prepared in accordance with...

7 CFR 58.331 - Starter distillate.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Specifications for Dairy Plants Approved for USDA Inspection and Grading Service 1 Quality Specifications for Raw Material § 58.331 Starter distillate. The refined flavor components when used to flavor butter and related products. It shall be of food grade quality, free of extraneous material and prepared in accordance with...

School Starters' Vision--An Educational Approach

ERIC Educational Resources Information Center

Wilhelmsen, Gunvor B

2016-01-01

Although good visual capacity is essential for children's learning, we have limited understanding of the various visual functions among school starters. In order to extend this knowledge, a small-scale study was undertaken involving 24 preschool children age 5-6 years who completed a test battery originally designed for visual impairment…

Genotypic and technological diversity of Brevibacterium linens strains for use as adjunct starter cultures in 'Pecorino di Filiano' cheese ripened in two different environments.

PubMed

Bonomo, Maria Grazia; Cafaro, Caterina; Salzano, Giovanni

2015-01-01

Twenty-two Brevibacterium linens strains isolated from 'Pecorino di Filiano' cheese ripened in two different environments (natural cave and storeroom) were characterized and differentiated for features of technological interest and by genotypic methods, in order to select strains with specific features to be used as surface starter cultures. Results showed significant differences among strains on the basis of physiological and technological features, indicating heterogeneity within the species. A middle-low level of proteolytic activity was observed in 27.3 % of strains, while a small group (9.1 %) showed a high ability. Lipolytic activity was observed at three different temperatures and the highest value was detected at 20 °C with 13.6 % of strains, while an increase in temperature produced a slightly lower lipolysis in all strains. The evaluation of diacetyl production revealed that only 22.8 % of strains showed this ability, and most of them were isolated from product ripened in the natural cave. All strains exhibited only leu-aminopeptidase activity, with values more elevated in strains coming from the natural cave product. The combined analysis of genotypic results with the data obtained by the features of technological interest study established that the random amplified polymorphic DNA (RAPD) clusters obtained were composed not only of different genotypes but of different profiles based on technological properties too. This study demonstrated the importance of the ripening environment that affects the typical features of the artisanal product, leading to the selection of a specific surface microflora. Characterized strains could be associated within surface starters to standardize the production process of cheese, but preserving its typical organoleptic and sensory characteristics and improving the quality of the final product.

Monitoring the Bacterial Population Dynamics in Sourdough Fermentation Processes by Using PCR-Denaturing Gradient Gel Electrophoresis

PubMed Central

Meroth, Christiane B.; Walter, Jens; Hertel, Christian; Brandt, Markus J.; Hammes, Walter P.

2003-01-01

Four sourdoughs (A to D) were produced under practical conditions by using a starter mixture of three commercially available sourdough starters and a baker's yeast constitutively containing various species of lactic acid bacteria (LAB). The sourdoughs were continuously propagated until the composition of the LAB flora remained stable. Two LAB-specific PCR-denaturing gradient gel electrophoresis (DGGE) systems were established and used to monitor the development of the microflora. Depending on the prevailing ecological conditions in the different sourdough fermentations, only a few Lactobacillus species were found to be competitive and became dominant. In sourdough A (traditional process with rye flour), Lactobacillus sanfranciscensis and a new species, L. mindensis, were detected. In rye flour sourdoughs B and C, which differed in the process temperature, exclusively L. crispatus and L. pontis became the predominant species in sourdough B and L. crispatus, L. panis, and L. frumenti became the predominant species in sourdough C. On the other hand, in sourdough D (corresponding to sourdough C but produced with rye bran), L. johnsonii and L. reuteri were found. The results of PCR-DGGE were consistent with those obtained by culturing, except for sourdough B, in which L. fermentum was also detected. Isolates of the species L. sanfranciscensis and L. fermentum were shown by randomly amplified polymorphic DNA-PCR analysis to originate from the commercial starters and the baker's yeast, respectively. PMID:12514030

Proteolytic and antimicrobial activity of lactic acid bacteria grown in goat milk.

PubMed

Atanasova, Jivka; Moncheva, Penka; Ivanova, Iskra

2014-11-02

We examined 62 strains and 21 trade starter cultures from the collection of LB Bulgaricum PLC for proteolytic and antimicrobial activity of lactic acid bacteria (LAB) grown in goat milk. The aim of this study was to investigate the fermentation of caseins, α-lactalbumin and β-lactoglobulin by LAB, using the o -phthaldialdehyde (OPA) spectrophotometric assay and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The proteolysis targeted mainly caseins, especially β-casein. Whey proteins were proteolyzed, essentially β-lactoglobulin. The proteolytic activity of Lactococcus lactis l598, Streptococcus thermophilus t3D1, Dt1, Lactobacillus lactis 1043 and L. delbrueckii subsp. bulgaricus b38, b122 and b24 was notably high. The proteolysis process gave rise to medium-sized peptide populations. Most of the examined strains showed antimicrobial activity against some food pathogens, such as Escherichia coli , Staphylococcus aureus , Salmonella cholere enteridis , Listeria monocytogenes , Listeria innocua and Enterobacter aerogenes . The most active producers of antimicrobial-active peptides were strains of L. delbrueckii subsp. bulgaricus and S. thermophilus , which are of practical importance. The starter cultures containing the examined species showed high proteolytic and antimicrobial activity in skimmed goat milk. The greatest antimicrobial activity of the cultures was detected against E. aerogenes . The obtained results demonstrated the significant proteolytic potential of the examined strains in goat milk and their potential for application in the production of dairy products from goat's milk. The present results could be considered as the first data on the proteolytic capacity of strains and starter cultures in goat milk for the purposes of trade interest of LB Bulgaricum PLC.

Molecular Detection of Two Potential Probiotic Lactobacilli Strains and Evaluation of Their Performance as Starter Adjuncts in Yogurt Production.

PubMed

Saxami, Georgia; Papadopoulou, Olga S; Chorianopoulos, Nikos; Kourkoutas, Yiannis; Tassou, Chrysoula C; Galanis, Alex

2016-05-04

A molecular method for efficient and accurate detection and identification of two potential probiotic lactobacilli strains isolated from fermented olives, namely Lactobacillus pentosus B281 and Lb. plantarum B282, was developed in the present study. Random Amplified Polymorphic DNA (RAPD) analysis was performed, and strain specific primers were designed and applied in a multiplex polymerase chain reaction (PCR) assay. The specificity of the assay was tested and successfully confirmed in 27 and 22 lactobacilli strains for Lb. pentosus B281 and Lb. plantarum B282, respectively. Moreover, the two strains were used as starter cultures in yogurt production. Cell enumeration followed by multiplex PCR analysis demonstrated that the two strains were present in yogurt samples at levels ≥6 log CFU/g even after 35 days of storage at 4 °C. Microbiological analysis showed that lactobacilli and streptococci were present within usual levels, whereas enterobacteriaceae and yeast/mold counts were not detected as expected. Although the pH values of the novel products were slightly lower than the control ones, the yogurt containing the probiotic cultures scored similar values compared to the control in a series of sensory tests. Overall, these results demonstrated the possible use of the two strains as starter adjuncts in the production of yogurt with potential probiotic properties.

Photographic and LMA observations of a blue starter over a New Mexico thunderstorm

NASA Astrophysics Data System (ADS)

Edens, H. E.; Krehbiel, P. R.; Rison, W.; Hunyady, S. J.

2010-12-01

On the evening of August 3, 2010 we photographed a blue starter over an electrically active storm complex about 120 km to the WNW of Langmuir Laboratory in central New Mexico. The event occurred close to a broad overshooting top at an altitude of 15 km above MSL. It was also observed visually and detected by the Lightning Mapping Array (LMA) deployed around the mountaintop observatory. The blue starter appears as a white-blue leader channel propagating away from the storm top not straight upward but at a large angle from vertical, slightly curving upward and transitioning to an increasingly diffuse blue glow. In addition to this leader, a more diffuse glow of blue light from one or two additional leaders is seen in the background. The curved channel of the main leader and the fact that it did not propagate along a straight path upward indicates that a relatively strong local electric field near the storm top existed that dictated leader propagation and direction rather than the large-scale storm electric field. The visible part of the starter is estimated to have developed to about 1 km above the storm top. From the LMA data we infer that the blue starter was a screening layer discharge that initiated between upper positive charge and a negatively charged screening layer. A negative leader appears to initiate at 15 km altitude and propagates downward for 2 to 3 km, after which scattered and ill-defined activity occurred in the cloud between 10 to 15 km altitude. This indicates that the visible part of the blue starter emanating out of the storm top, which was photographed but not detected by the LMA, was positive breakdown. The event lasted for 100 ms in the LMA data. The storm where the starter occurred in was producing predominantly intracloud (IC) flashes at a rate of about 20 per minute. The starter itself occurred independently of other discharges in the storm about 4 seconds after a normal polarity IC flash. About 5 minutes after the first blue starter, a

Performance changes in NBA basketball players vary in starters vs. nonstarters over a competitive season.

PubMed

Gonzalez, Adam M; Hoffman, Jay R; Rogowski, Joseph P; Burgos, William; Manalo, Edwin; Weise, Keon; Fragala, Maren S; Stout, Jeffrey R

2013-03-01

The purpose of this study was to compare starters (S) with nonstarters (NS), on their ability to maintain strength, power, and quickness during a competitive National Basketball Association (NBA) season. Twelve NBA players were assessed at the beginning and end of the competitive season. However, because of trades and injury, only 7 (S = 4, NS = 3) players (28.2 ± 3.4 years; 200.9 ± 9.4 cm; 104.7 ± 13.9 kg; 7.2 ± 1.9% body fat) participated in both testing sessions and underwent analysis. Anthropometric performance (repetitive vertical jump power [VJP], squat power [SQT power], and reaction time) and subjective feelings of energy, focus, alertness, and fatigue were recorded during each testing session. Results were interpreted using magnitude-based statistics to make inferences on true differences between starters and nonstarters using the unequal variances t-statistic. Starters played an average of 27.8 ± 6.9 minutes per game and nonstarters played an average of 11.3 ± 7.0 minutes per game. During the course of the season, changes in VJP indicated that starters were likely to increase VJP (Δ = 77.3 ± 78.1 W) compared to nonstarters (Δ= -160.0 ± 151.0 W). There also appeared to be a possible beneficial effect on maintaining reaction time in starters (Δ = 0.005 ± 0.074 seconds) compared with nonstarters (Δ = 0.047 ± 0.073 seconds). In addition, no clear differences in ΔSQT power were seen between starters (Δ = 110.8 ± 141.4 W) and nonstarters (Δ = 143.5 ± 24.7 W). Changes in subjective feelings of energy indicated that starters were very likely to maintain their energy over the course of a season. It also appeared possible that starters were able to have a more positive response to subjective measures of fatigue and alertness than nonstarters, with only trivial differences between starters and nonstarters in regards to maintaining focus. Results of this study suggest that NBA players may enhance lower-body power, repetitive jump ability, and

Genotypic and technological characterization of Leuconostoc isolates to be used as adjunct starters in Manchego cheese manufacture.

PubMed

Nieto-Arribas, Pedro; Seseña, Susana; Poveda, Justa M; Palop, Llanos; Cabezas, Lourdes

2010-02-01

Twenty-seven Leuconostoc (Ln.) isolates from Manchego cheese were characterized by phenotypic and genotypic methods, and their technological abilities studied in order to test their potential use as dairy starter components. While phenotypic diversity was evaluated by studying the biochemical characteristics of technological interest (i.e. acidifying and aminopeptidase activities), genotypic diversity was evidenced by using Randomly Amplified Polymorphic DNA-Polymerase Chain Reaction (RAPD-PCR). Additional technological abilities such as lipolytic, proteolytic and autolytic activities, salt and pH tolerance and production of dextran, flavour compounds and biogenic amines, were investigated. The marked differences among strains reflected the existing biodiversity in naturally fermented products. After statistically evaluating their performance, strains C0W2, belonging to Ln. lactis, and C16W5 and N2W5, belonging to Ln. mesenteroides subsp. dextranicum, revealed the best properties to be used in mixed dairy starter cultures. This study evidences the fact that natural environments can be considered as a proper source of useful strains, for the dairy industry.

Redefining the effect of salt on thermophilic starter cell viability, culturability and metabolic activity in cheese.

PubMed

Hickey, C D; Fallico, V; Wilkinson, M G; Sheehan, J J

2018-02-01

This study investigated the differential effect of salt concentration in the outside and inside layers of brine salted cheeses on viability, culturability and enzyme activity of starter bacteria. The high-salt environment of the outside layer caused a sharp decrease in L. helveticus viability as measured by traditional plate counts. Remarkably, this was associated with lower release of intracellular enzymes (LDH), reduced levels of proteolysis and larger membrane integrity as measured by flow cytometry (FC) following classical Live/Dead staining. FC analysis of light scattering properties highlighted a significant reduction in size and granularity of the microbiota located in the cheese surface, suggestive of cell shrinkage and condensation of internal macromolecules probably due to hyperosmotic stress. The microbiota of the cheese surface were found to experience greater oxidative stress, as measured by FC analysis of the total levels of reactive oxygen species, compared to that of the interior layer. These results lead us to postulate that the physiology and health status of the microbiota were significantly different in the outer and inner layers of the cheese. The hyperosmotic environment of the outer layer resulted in reduced cell lysis, as measurable by assays based upon membrane integrity, but rather triggered cell death via mechanisms involving cell shrinkage and ROS-mediated damage of vital intracellular components. This study challenges the current thinking on how salt controls microbial activity in ripening cheese, especially in cheeses which are brine salted as local variations in biochemical ripening indices can differ significantly from the outside to the inside of a ripening cheese. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of the Essential Oil from Origanum vulgare L. on Survival of Pathogenic Bacteria and Starter Lactic Acid Bacteria in Semihard Cheese Broth and Slurry.

PubMed

de Souza, Geany Targino; de Carvalho, Rayssa Julliane; de Sousa, Jossana Pereira; Tavares, Josean Fechine; Schaffner, Donald; de Souza, Evandro Leite; Magnani, Marciane

2016-02-01

This study assessed the inhibitory effects of the essential oil from Origanum vulgare L. (OVEO) on Staphylococcus aureus, Listeria monocytogenes, and a mesophilic starter coculture composed of lactic acid bacteria (Lactococcus lactis subsp. lactis and L. lactis subsp. cremoris) in Brazilian coalho cheese systems. The MIC of OVEO was 2.5 μl/ml against both S. aureus and L. monocytogenes and 0.6 μl/ml against the tested starter coculture. In cheese broth containing OVEO at 0.6 μl/ml, no decrease in viable cell counts (VCC) of both pathogenic bacteria was observed, whereas the initial VCC of the starter coculture decreased approximately 1.0 log CFU/ml after 24 h of exposure at 10°C. OVEO at 1.25 and 2.5 μl/ml caused reductions of up to 2.0 and 2.5 log CFU/ml in S. aureus and L. monocytogenes, respectively, after 24 h of exposure in cheese broth. At these same concentrations, OVEO caused a greater decrease of initial VCC of the starter coculture following 4 h of exposure. Higher concentrations of OVEO were required to decrease the VCC of all target bacteria in semisolid coalho cheese slurry compared with cheese broth. The VCC of Lactococcus spp. in coalho cheese slurry containing OVEO were always lower than those of pathogenic bacteria under the same conditions. These results suggest that the concentrations of OVEO used to control pathogenic bacteria in semihard cheese should be carefully evaluated because of its inhibitory effects on the growth of starter lactic acid cultures used during the production of the product.

Interaction between milk allowance and fat content of the starter feed on performance of Holstein calves.

PubMed

Araujo, G; Terré, M; Bach, A

2014-10-01

Sixty-six Holstein male calves [42 ± 6.0 kg of body weight (BW) and 12 ± 3.1 d of age] were housed individually and allocated to 1 of 4 treatments following a 2 × 2 factorial complete randomized design to assess the potential interaction between milk replacer (MR) allowance and fat content in the starter feed. Thus, 4 treatments were evaluated: a low-fat (4.1% fat; LF) starter feed offered along with 4 L/d of MR (4 LF), a high-fat (11.2% fat; HF) starter feed plus 4 L/d of MR (4 HF), a LF starter feed offered with 6 L/d of MR (6LF), and an HF starter feed offered with 6 L/d of MR (6 HF). Calves were fed either 4 or 6 L/d of MR (25% crude protein and 19.2% fat) in 2 offers (0800 and 1630 h) and had ad libitum access to either an LF or an HF starter feed (21.4 and 22.3% crude protein). Calves were weaned at wk 6 of study by halving the daily MR allowance for 1 wk. Individual MR and starter feed intakes were recorded daily and BW was determined weekly. A glucose tolerance test was performed on d 30 of study to evaluate the effects of increased energy provision on glucose metabolism. Apparent feed digestibility was measured for the last 5 d of study. Overall, fat content of starter feed had no effect on solid feed intake. However, during wk 8 of study (after weaning), calves in the LF treatment had greater starter feed intake than HF calves. Calves on 6 L/d of MR had greater BW than calves fed 4 L/d from the second week of study until weaning. After weaning, 6 LF calves had lesser BW than 6 HF calves. Calves on 6 L/d of MR had greater average daily gain than calves fed 4 L/d, and 6 HF calves tended to have the greatest average daily gain. Glucose clearance rate tended to be lesser for HF than for LF calves. In conclusion, offering 6 L/d of MR increased growth performance before weaning and, when offering 6 L/d of MR, feeding a high-fat starter feed resulted in the greatest BW after weaning. Copyright © 2014 American Dairy Science Association. Published by Elsevier

Tracing microbiota changes in yamahai-moto, the traditional Japanese sake starter.

PubMed

Koyanagi, Takashi; Nakagawa, Akira; Kiyohara, Masashi; Matsui, Hiroshi; Tsuji, Atsushi; Barla, Florin; Take, Harumi; Katsuyama, Yoko; Tokuda, Koji; Nakamura, Shizuo; Minami, Hiromichi; Enomoto, Toshiki; Katayama, Takane; Kumagai, Hidehiko

2016-01-01

Sake is made from steamed rice, malted rice, and water. Sake production begins with the preparation of a small-scale starter (moto); the quality of moto significantly influences the flavor and richness of sake. In the traditional starter, yamahai-moto, the growth of naturally occurring lactic acid bacteria represses the putrefactive micro-organisms, whereas in the modern starter, sokujo-moto, this is achieved by adding lactic acid. In this study, the successive change in bacterial flora of yamahai-moto was analyzed by pyrosequencing 16S ribosomal RNA genes. Lactobacillus was dominant throughout the process (93-98%). Nitrate-reducing bacteria that have been generally assumed to be the first colonizers of yamahai-moto were scarcely found in the early stage, but Lactobacillus acidipiscis dominated. Lactobacillus sakei drastically increased in the middle stage. This is the first report, though one case study, to show how the early stage microbiota in Japanese yamahai-moto is varyingly controlled without nitrate-reducing bacteria using next-generation sequencing.

Evaluation of the microbial community in industrial rye sourdough upon continuous back-slopping propagation revealed Lactobacillus helveticus as the dominant species.

PubMed

Viiard, E; Mihhalevski, A; Rühka, T; Paalme, T; Sarand, I

2013-02-01

To assess the structure and stability of a dominant lactic acid bacteria (LAB) population during the propagation of rye sourdough in an industrial semi-fluid production over a period of 7 months. The sourdough was started from a 6-year-old freeze-dried sourdough originating from the same bakery. A unique microbial consortium consisting mainly of bacteria belonging to species Lactobacillus helveticus, Lactobacillus panis and Lactobacillus pontis was identified based on culture-dependent (Rep-PCR) and culture-independent [denaturing gradient gel electrophoresis (DGGE)] methods. Three of the isolated Lact. helveticus strains showed remarkable adaptation to the sourdough conditions. They differed from the type strain by the ability to ferment compounds specific to plant material, like salicin, cellobiose and sucrose, but did not ferment lactose. We showed remarkable stability of a LAB consortium in rye sourdough started from lyophilized sourdough and propagated in a large bakery for 7 months. Lactobacillus helveticus was detected as the dominant species in the consortium and was shown to be metabolically adapted to the sourdough environment. The use of an established and adapted microbial consortium as a starter is a good alternative to commercial starter strains. © 2012 The Society for Applied Microbiology.

Die Starter: A New System to Manage Early Feasibility in Sheet Metal Forming

NASA Astrophysics Data System (ADS)

Narainen, Rodrigue; Porzner, Harald

2016-08-01

Die Starter, a new system developed by ESI Group, allows the user to drastically reduce the number of iterations during the early tool process feasibility. This innovative system automatically designs the first quick die face, generating binder and addendum surfaces (NURBS surfaces) by taking account the full die process. Die Starter also improves the initial die face based on feasibility criteria (avoiding splits, wrinkles) by automatically generating the geometrical modifications of the binder and addendum and the bead restraining forces with minimal material usage. This paper presents a description of the new system and the methodology of Die Starter. Some industrial examples are presented from the part geometry to final die face including automatic developed flanges, part on binder and inner binder.

Plasma concentrations of glucagon-like peptide 1 and 2 in calves fed calf starters containing lactose.

PubMed

Inabu, Y; Saegusa, A; Inouchi, K; Koike, S; Oba, M; Sugino, T

2017-11-01

The objective of this study was to evaluate the effects of lactose inclusion in calf starters on plasma glucagon-like peptide (GLP)-1 and GLP-2 concentrations and gastrointestinal tract development in calves. Holstein bull calves (n = 45) were raised on an intensified nursing program using milk replacer containing 28.0% CP and 15.0% fat, and were fed a texturized calf starter containing 0 (control), 5.0 (LAC5), or 10.0% (LAC10; n = 15 for each treatment) lactose on a DM basis. Lactose was included in the starter by partially replacing dry ground corn in pelleted portion of the starter. All calf starters were formulated with 23.1% CP. The ethanol-soluble carbohydrate concentrations of the control, LAC5, and LAC10 starters were 7.3, 12.3, and 16.8% on a DM basis, respectively. Starch concentrations of the control, LAC5, and LAC10 starters were 29.7, 27.0, and 21.4% on a DM basis, respectively. All calves were fed treatment calf starters ad libitum. Blood samples were obtained weekly from 1 to 11 wk of age, and used to measure plasma GLP-1, GLP-2, and insulin concentrations, serum β-hydroxybutyrate (BHB) concentration, and blood glucose concentration. At 80 d of age, calves were euthanized, and weights of the reticulorumen, omasum, abomasum, small intestine, and large intestine tissue were measured. Serum BHB concentration was higher for calves fed the LAC10 (171 μmol/L) starter than for those fed the control (151 μmol/L) and LAC5 (145 μmol/L) starters. Plasma GLP-1 and GLP-2 concentrations did not differ between treatments. However, relative to the baseline (1 wk of age), the plasma GLP-1 concentration was higher for the LAC10 (125.9%) than for the LAC5 (68.2%) and control (36.8%), and for the LAC5 than for the control (36.8%). Moreover, similar differences between treatments were observed for GLP-2 concentration relative to the baseline (88.2, 76.9, and 74.9% for LAC10, LAC5, and control treatments, respectively). The serum BHB concentration was positively

Rational selection of Leuconostoc strains for mixed starters based on the physiological biodiversity found in raw milk fermentations.

PubMed

Sánchez, Jorge Ignacio; Martínez, Beatriz; Rodríguez, Ana

2005-12-15

The technological abilities of eleven wild Leuconostoc strains isolated from artisanal Afuega'l Pitu cheese, a homemade acid-coagulated cheese from raw milk from Asturias (northern Spain), were studied in order to test their potential application as components of dairy starters. Metabolic activity, production of flavour compounds, resistance to NaCl, acid, nisin and freezing, as well as genetic biodiversity were investigated. Marked differences among all tested strains reflected the existing biodiversity in naturally fermented products. After evaluation of their performance, strains IPLA567 and IPLA979 revealed the best properties to be used use in mixed dairy starter cultures. These two strains were able to ferment lactose and galactose and produced larger amounts of lactic acid than the others. Moreover, they showed high tolerance levels to NaCl, acid and nisin, although their resistance to freezing was slightly lower than the other strains. This study evidences the fact that natural environments can be considered as a proper source of new strains, which may help the dairy industry to widen their fermented products range.

Model-based strategy for cell culture seed train layout verified at lab scale.

PubMed

Kern, Simon; Platas-Barradas, Oscar; Pörtner, Ralf; Frahm, Björn

2016-08-01

Cell culture seed trains-the generation of a sufficient viable cell number for the inoculation of the production scale bioreactor, starting from incubator scale-are time- and cost-intensive. Accordingly, a seed train offers potential for optimization regarding its layout and the corresponding proceedings. A tool has been developed to determine the optimal points in time for cell passaging from one scale into the next and it has been applied to two different cell lines at lab scale, AGE1.HN AAT and CHO-K1. For evaluation, experimental seed train realization has been evaluated in comparison to its layout. In case of the AGE1.HN AAT cell line, the results have also been compared to the formerly manually designed seed train. The tool provides the same seed train layout based on the data of only two batches.

Lactic acid bacteria and yeasts associated with gowé production from sorghum in Bénin.

PubMed

Vieira-Dalodé, G; Jespersen, L; Hounhouigan, J; Moller, P L; Nago, C M; Jakobsen, M

2007-08-01

To identify the dominant micro-organisms involved in the production of gowé, a fermented beverage, and to select the most appropriate species for starter culture development. Samples of sorghum gowé produced twice at three different production sites were taken at different fermentation times. DNA amplification by internal transcribed spacer-polymerase chain reaction of 288 lactic acid bacteria (LAB) isolates and 16S rRNA gene sequencing of selected strains revealed that the dominant LAB responsible for gowé fermentation were Lactobacillus fermentum, Weissella confusa, Lactobacillus mucosae, Pediococcus acidilactici, Pediococcus pentosaceus and Weissella kimchii. DNA from 200 strains of yeasts was amplified and the D1/D2 domain of the 26S rRNA gene was sequenced for selected isolates, revealing that the yeasts species were Kluyveromyces marxianus, Pichia anomala, Candida krusei and Candida tropicalis. Gowé processing is characterized by a mixed fermentation dominated by Lact. fermentum, W. confusa and Ped. acidilactici for the LAB and by K. marxianus, P. anomala and C. krusei for the yeasts. The diversity of the LAB and yeasts identified offers new opportunities for technology upgrading and products development in gowé production. The identified species can be used as possible starter for a controlled fermentation of gowé.

Sodium reduction in starter-free Queso Fresco

USDA-ARS?s Scientific Manuscript database

Creating lower sodium Queso Fresco (QF) for health conscious consumers is a challenge when this high-moisture, higher pH, starter-free cheese relies on high salt levels to control the microflora and to obtain its signature salty taste. In phase 1, QF made from pasteurized, homogenized bovine milk wi...

From Good to Great: Discussion Starter Tool

ERIC Educational Resources Information Center

Center on Great Teachers and Leaders, 2014

2014-01-01

In the report "From Good to Great: Exemplary Teachers Share Perspectives on Increasing Teacher Effectiveness across the Career Continuum," (See full report in ERIC at ED555657) National and State Teachers of the Year shared their views on what helped them become great teachers. This accompanying "Discussion Starter Tool" builds…

Molecular Detection of Two Potential Probiotic Lactobacilli Strains and Evaluation of Their Performance as Starter Adjuncts in Yogurt Production

PubMed Central

Saxami, Georgia; Papadopoulou, Olga S.; Chorianopoulos, Nikos; Kourkoutas, Yiannis; Tassou, Chrysoula C.; Galanis, Alex

2016-01-01

A molecular method for efficient and accurate detection and identification of two potential probiotic lactobacilli strains isolated from fermented olives, namely Lactobacillus pentosus B281 and Lb. plantarum B282, was developed in the present study. Random Amplified Polymorphic DNA (RAPD) analysis was performed, and strain specific primers were designed and applied in a multiplex polymerase chain reaction (PCR) assay. The specificity of the assay was tested and successfully confirmed in 27 and 22 lactobacilli strains for Lb. pentosus B281 and Lb. plantarum B282, respectively. Moreover, the two strains were used as starter cultures in yogurt production. Cell enumeration followed by multiplex PCR analysis demonstrated that the two strains were present in yogurt samples at levels ≥6 log CFU/g even after 35 days of storage at 4 °C. Microbiological analysis showed that lactobacilli and streptococci were present within usual levels, whereas enterobacteriaceae and yeast/mold counts were not detected as expected. Although the pH values of the novel products were slightly lower than the control ones, the yogurt containing the probiotic cultures scored similar values compared to the control in a series of sensory tests. Overall, these results demonstrated the possible use of the two strains as starter adjuncts in the production of yogurt with potential probiotic properties. PMID:27153065

The development of tobacco use in adolescence among "snus starters" and "cigarette starters": an analysis of the Swedish "BROMS" cohort.

PubMed

Galanti, Maria Rosaria; Rosendahl, Ingvar; Wickholm, Seppo

2008-02-01

Whether the use of smokeless tobacco can facilitate the transition to cigarette smoking and/or to prolonged tobacco use in adolescence is unclear. We analyzed data from a cohort of 2,938 Swedish adolescents, with six follow-up assessments of tobacco use between the ages of 11 and 18 years. The majority of tobacco users (70%) started by smoking cigarettes, 11% took up snus before smoking, and 19% used both tobacco types close in time. Ever users of tobacco at baseline had a higher risk of being current smokers and/or smokeless tobacco users at the end of follow-up compared with never users, with the highest excess relative risk for "mixed users." Adolescents who initiated tobacco use with cigarettes had a non-significantly increased probability to end up as current smokers compared with snus starters (adjusted OR=1.42; 95% CI 0.98-2.10) The OR of smoking for "mixed starters" was 2.54 (95% CI 1.68-3.91). The risk of becoming current user of any tobacco was also significantly enhanced for "mixed starters." Marked sex differences were observed in these associations, as initiation with cigarettes rather than with snus predicted current smoking or tobacco use only among females. Progression of tobacco use in adolescence is not predicted by onset with snus or cigarettes, but rather by initiation with both tobacco types close in time and/or at young age. The proportion of adolescent smoking prevalence attributable to a potential induction effect of snus is likely small.

Microbial Ecology and Process Technology of Sourdough Fermentation.

PubMed

De Vuyst, Luc; Van Kerrebroeck, Simon; Leroy, Frédéric

2017-01-01

From a microbiological perspective, sourdough is to be considered as a specific and stressful ecosystem, harboring yeasts and lactic acid bacteria (LAB), that is used for the production of baked goods. With respect to the metabolic impact of the sourdough microbiota, acidification (LAB), flavor formation (LAB and yeasts), and leavening (yeasts and heterofermentative LAB species) are most noticeable. Three distinct types of sourdough fermentation processes can be discerned based on the inocula applied, namely backslopped ones (type 1), those initiated with starter cultures (type 2), and those initiated with a starter culture followed by backslopping (type 3). A sourdough-characteristic LAB species is Lactobacillus sanfranciscensis. A sourdough-characteristic yeast species is Candida humilis. Although it has been suggested that the microbiota of a specific sourdough may be influenced by its geographical origin, region specificity often seems to be an artefact resulting from interpretation of the research data, as those are dependent on sampling, isolation, and identification procedures. It is however clear that sourdough-adapted microorganisms are able to withstand stress conditions encountered during their growth. Based on the technological setup, type 0 (predoughs), type I (artisan bakery firm sourdoughs), type II (industrial liquid sourdoughs), and type III sourdoughs (industrial dried sourdoughs) can be distinguished. The production of all sourdoughs, independent of their classification, depends on several intrinsic and extrinsic factors. Both the flour (type, quality status, etc.) and the process parameters (fermentation temperature, pH and pH evolution, dough yield, water activity, oxygen tension, backslopping procedure and fermentation duration, etc.) determine the dynamics and outcome of (backslopped) sourdough fermentation processes. Copyright © 2017 Elsevier Inc. All rights reserved.

Pellet starters in layering technique using concentrated drug solution.

PubMed

Gryczová, Eva; Rabisková, Miloslava; Vetchý, David; Krejcová, Katerina

2008-12-01

Characteristics of inert starters in drug solution layering are important for successful active pellet formation. Four types of starters composed of sucrose or microcrystalline cellulose (MCC) or lactose and MCC were compared in our study. The active pellets were prepared using Wurster type apparatus. Yield and pellet quality parameters were determined. The highest yield (85.66-89.41%) was obtained for cores composed of MCC due to their insolubility in water (the drug solvent) and good mechanical properties. On the contrary, soluble and brittle sucrose cores dissolved partially during the process forming undesirable agglomerates and giving lower yield (76.2%). All pellet samples showed good flow properties and drug content from 82.4 to 94.5% of the theoretical drug amount.

77 FR 8898 - Certain Starter Motors and Alternators; Determination Not To Review an Initial Determination...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-15

... joint motion to terminate the investigation as to respondent Electric Motor Service, Inc. (EMS) of Logan... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-755] Certain Starter Motors and... for importation, and the sale within the United States after importation of certain starter motors and...

Differences between Cheddar cheese manufactured by the milled-curd and stirred-curd methods using different commercial starters.

PubMed

Shakeel-ur-Rehman; Drake, M A; Farkye, N Y

2008-01-01

Traditionally, Cheddar cheese is made by the milled-curd method. However, because of the mechanization of cheese making and time constraints, the stirred-curd method is more commonly used by many large-scale commercial manufacturers. This study was undertaken to evaluate quality differences during ripening (at 2 and 8 degrees C) of Cheddar cheese made by the milled-curd and stirred-curd methods, using 4 different commercial starters. Twenty-four vats (4 starters x 2 methods x 3 replicates) were made, with approximately 625 kg of pasteurized (72 degrees C x 16 s) whole milk in each vat. Fat, protein, and salt contents of the cheeses were not affected by the starter. Starter cell densities in cheese were not affected by the method of manufacture. Nonstarter lactic acid bacteria counts at 90, 180, and 270 d were influenced by the manufacturing method, with a higher trend in milled-curd cheeses. Proteolysis in cheese (percentage of water-soluble N) was influenced by the starter and manufacturing method (270 d). Sensory analysis by a trained descriptive panel (n = 8) revealed differences in cooked, whey, sulfur, brothy, milk fat, umami, and bitter attributes caused by the starter, whereas only brothy flavor was influenced by storage temperature. The method of manufacture influenced diacetyl, sour, and salty flavors.

Production, properties, and industrial food application of lactic acid bacteria-derived exopolysaccharides.

PubMed

Zannini, Emanuele; Waters, Deborah M; Coffey, Aidan; Arendt, Elke K

2016-02-01

Exopolysaccharides (EPS)-producing lactic acid bacteria (LAB) are industrially important microorganisms in the development of functional food products and are used as starter cultures or coadjutants to develop fermented foods. There is large variability in EPS production by LAB in terms of chemical composition, quantity, molecular size, charge, presence of side chains, and rigidity of the molecules. The main body of the review will cover practical aspects concerning the structural diversity structure of EPS, and their concrete application in food industries is reported in details. To strengthen the food application and process feasibility of LAB EPS at industrial level, a future academic research should be combined with industrial input to understand the technical shortfalls that EPS can address.

Supplementation with fruit and okara soybean by-products and amaranth flour increases the folate production by starter and probiotic cultures.

PubMed

Albuquerque, Marcela Albuquerque Cavalcanti de; Bedani, Raquel; Vieira, Antônio Diogo Silva; LeBlanc, Jean Guy; Saad, Susana Marta Isay

2016-11-07

The ability of two starter cultures (Streptococcus (S.) thermophilus ST-M6 and St. thermophilus TA-40) and eleven probiotic cultures (St. thermophilus TH-4, Lactobacillus (Lb.) acidophilus LA-5, Lb. fermentum PCC, Lb. reuteri RC-14, Lb. paracasei subsp. paracasei, Lb. casei 431, Lb. paracasei subsp. paracasei F19, Lb. rhamnosus GR-1, and Lb. rhamnosus LGG, Bifidobacterium (B.) animalis subsp. lactis BB-12, B. longum subsp. longum BB-46, and B. longum subsp. infantis BB-02) to produce folate in a modified MRS broth (mMRS) supplemented with different fruit (passion fruit, acerola, orange, and mango) and okara soybean by-products and amaranth flour was investigated. Initially, the folate content of each vegetable substrate was determined: passion fruit by-product showed the lowest folate content (8±2ng/mL) and okara the highest (457±22ng/mL). When the orange by-product and amaranth flour were added to mMRS, all strains were able to increase folate production after 24h of fermentation. B. longum subsp infantis BB-02 produced the highest concentrations (1223±116ng/mL) in amaranth flour. Okara was the substrate that had the lowest impact on the folate production by all strains evaluated. Lb. acidophilus LA-5 (297±36ng/mL) and B. animalis subsp. lactis BB-12 (237±23ng/mL) were also able to produce folate after growth in mMRS containing acerola and orange by-products, respectively. The results of this study demonstrate that folate production is not only strain-dependent but also influenced by the addition of different substrates in the growth media. Copyright © 2016 Elsevier B.V. All rights reserved.

Modelling and predicting the simultaneous growth of Escherichia coli and lactic acid bacteria in milk.

PubMed

Ačai, P; Valík, L'; Medved'ová, A; Rosskopf, F

2016-09-01

Modelling and predicting the simultaneous competitive growth of Escherichia coli and starter culture of lactic acid bacteria (Fresco 1010, Chr. Hansen, Hørsholm, Denmark) was studied in milk at different temperatures and Fresco inoculum concentrations. The lactic acid bacteria (LAB) were able to induce an early stationary state in E. coli The developed model described and tested the growth inhibition of E. coli (with initial inoculum concentration 10(3) CFU/mL) when LAB have reached maximum density in different conditions of temperature (ranging from 12 ℃ to 30 ℃) and for various inoculum sizes of LAB (ranging from approximately 10(3) to 10(7) CFU/mL). The prediction ability of the microbial competition model (the Baranyi and Roberts model coupled with the Gimenez and Dalgaard model) was first performed only with parameters estimated from individual growth of E. coli and the LAB and then with the introduced competition coefficients evaluated from co-culture growth of E. coli and LAB in milk. Both the results and their statistical indices showed that the model with incorporated average values of competition coefficients improved the prediction of E. coli behaviour in co-culture with LAB. © The Author(s) 2015.

Symbiosis between microorganisms from kombucha and kefir: Potential significance to the enhancement of kombucha function.

PubMed

Yang, Zhiwei; Zhou, Feng; Ji, Baoping; Li, Bo; Luo, Yangchao; Yang, Li; Li, Tao

2010-01-01

Gluconacetobacter sp. A4 (G. sp. A4), which had strong ability to produce d-saccharic acid 1, 4 lactone (DSL), was the key functional bacteria isolated from the kombucha preserved. This paper investigated the interaction between G. sp. A4 and ten different strains of lactic acid bacteria (LAB) obtained from kefir. The result suggested that the LAB promoted DSL production of G. sp. A4 to different extents, ranging from 4.86% to 86.70%. Symbiosis between G. sp. A4 and LAB was studied. LAB's metabolites, xylitol, and acetic acid, were utilized by G. sp. A4, and it promoted the growth of G. sp. A4 and yield of DSL. Therefore, in developing starter cultures for kombucha fermentation process, a mixed flora of LAB and G. sp. A4 would be the optimal combination.

Biotechnological production of non-traditional beer

NASA Astrophysics Data System (ADS)

Parise, Adadi; Kovaleva, Elena G.; Glukhareva, Tatiana V.; Shatunova, Svetlana A.

2017-09-01

In the present study we brewed sorghum (pito) and low-alcoholic beer (LAB) utilizing Sacharomyces cerevisiae, Lactobacillus plantarum and Saccharomycodes ludwigii as starters, respectively, and characterized their quality parameters. Single infusion method of mashing was practiced. Physiochemical, sensory and antiradical properties of samples were determined. Pito was produced by pitching wort with S. cerevisae (single starter culture (SSC)) and S. cerevisae in combination with L. plantarum (mixed starter culture (MSC)). oBrix did not change over the next 24 hours for both cultures and began to decline, yet still it remain steady when the fermentation was over. After the end of fermentation, wort pitched with SSC showed lower oBrix (6.63±0.11), than the wort with MSC (6.73±0.20) and differ significantly (P < 0.05) with duration of the fermentation process. LAB also exhibited a decrease in oBrix from 12.2±0.12 to 8.04±0.01 at the end of the fermentation. Titratable acidity (TA) and pH remained constant after 24 hours of fermentation. TA began to increase from 0.73±0.02 to 1.04±0.02 and 0.73±0.02 to 1.07±0.02 for SSC and MSC, respectively. A decrease in pH from 4.33±0.20 to 3.86±0.15 and 4.33±0.20 to 4.2±0.1 was observed for SSC and MSC, respectively, during the rest of the fermentation period. A total of 22 volatile compounds including 11 esters, 3 alcohols and 8 acids, were identified in pito. Seven of these compounds were detected after the first fermentation (in green beer), whilst the rest (16 compounds) were distinguish after secondary fermentation. We also identified 8 volatiles in LAB, including 5 alcohols, 2 esters and 1 acid. Electron paramagnetic resonance spectroscopy of free radicals was used to determine the antiradical activity (AOA) of LAB in comparison with industrial alcoholic beverages (Baltica 7 from St Petersburg, Russia and Nectar beer from Bosnia-Herzegonia). LAB showed DPPH radical scavenging activity of 1.16 ×10-4 mol × equ (R2

Technological characterization and probiotic traits of yeasts isolated from Altamura sourdough to select promising microorganisms as functional starter cultures for cereal-based products.

PubMed

Perricone, Marianne; Bevilacqua, Antonio; Corbo, Maria Rosaria; Sinigaglia, Milena

2014-04-01

The main topic of this research was to select some suitable functional starter cultures for cereal-based food or beverages. This aim was achieved through a step-by step approach focused on the technological characterization, as well as on the evaluation of the probiotic traits of yeasts; the technological characterization relied on the assessment of enzymatic activities (catalase, urease, β-glucosidase), growth under various conditions (pH, temperature, addition of salt, lactic and acetic acids) and leavening ability. The results of this step were used as input data for a Principal Component Analysis; thus, the most technologically relevant 18 isolates underwent a second selection for their probiotic traits (survival at pH 2.5 and with bile salts added, antibiotic resistance, antimicrobial activity towards foodborne pathogens, hydrophobic properties and biofilm production) and were identified through genotyping. Two isolates (Saccharomyces cerevisiae strain 2 and S. cerevisiae strain 4) were selected and analyzed in the last step for the simulation of the gastric transit; these isolates showed a trend similar to S. cerevisiae var. boulardii ATCC MYA-796, a commercial probiotic yeast used as control. Copyright © 2013 Elsevier Ltd. All rights reserved.

Growth and morphology of thermophilic dairy starters in alginate beads.

PubMed

Lamboley, Laurence; St-Gelais, Daniel; Champagne, Claude P; Lamoureux, Maryse

2003-06-01

The aim of this research was to produce concentrated biomasses of thermophilic lactic starters using immobilized cell technology (ICT). Fermentations were carried out in milk using pH control with cells microentrapped in alginate beads. In the ICT fermentations, beads represented 17% of the weight. Some assays were carried out with free cells without pH control, in order to compare the ICT populations with those of classical starters. With Streptococcus thermophilus, overall populations in the fermentor were similar, but maximum bead population for (8.2 x 10(9) cfu/g beads) was 13 times higher than that obtained in a traditional starter (4.9 x 10(8) cfu/ml). For both Lactobacillus helveticus strains studied, immobilized-cell populations were about 3 x 10(9) cfu/g beads. Production of immobilized Lb. bulgaricus 210R strain was not possible, since no increases in viable counts occurred in beads. Therefore, production of concentrated cell suspension in alginate beads was more effective for S. thermophilus. Photomicrographs of cells in alginate beads demonstrated that, while the morphology of S. thermophilus remained unchanged during the ICT fermentation, immobilized cells of Lb. helveticus appeared wider. In addition, cells of Lb. bulgaricus were curved and elongated. These morphological changes would also impair the growth of immobilized lactobacilli.

Industrial application of selected lactic acid bacteria isolated from local semolinas for typical sourdough bread production.

PubMed

Corona, Onofrio; Alfonzo, Antonio; Ventimiglia, Giusi; Nasca, Anna; Francesca, Nicola; Martorana, Alessandra; Moschetti, Giancarlo; Settanni, Luca

2016-10-01

Four obligate heterofermentative lactic acid bacteria (LAB) strains (Weissella cibaria PON10030 and PON10032 and Leuconostoc citreum PON 10079 and PON10080) were tested as single strain starters, mono-species dual strain starters, and multiple strain starter for the preparation and propagation of sourdoughs for the production of a typical bread at industrial level. The kinetics of pH and TTA during the daily sourdough refreshments indicated a correct acidification process for all trials. The concentration of lactic and acetic acid increased consistently during fermentation. The resulting molar ratios between these two organic acids in the experimental trials were lower than those observed in the control trial. The microbiological investigation showed levels of approximately 10(9) CFU/mL in almost all sourdoughs and the comparison of the genetic polymorphisms of the dominating LAB with those of the pure cultures evidenced the persistence of the added strains over time. The resulting breads were evaluated for several quality parameters. The breads with the greatest height were obtained with the quadruple combination of leuconostocs and weissellas. The highest softness was registered for the breads obtained from fermentations performed by W. cibaria PON10032 alone and in combination. The different inocula influenced also the color, the void fraction, the cell density and the mean cell area of the breads. Different levels of acids, alcohols, aldehydes, esters, hydrocarbons, ketones, terpenes, furans and phenol were emitted by the breads. The sensory tests indicated the breads from the sourdoughs fermented with the seven LAB inocula as sweeter and less acidic than control breads and the breads from the trials with the highest complexity of LAB inoculums were those more appreciated by tasters. A multivariate approach found strong differences among the trials. In particular, control breads and the breads obtained with different starter LAB were quite distant and a more

Effect of wild strains used as starter cultures and adjunct cultures on the volatile compounds of the Pecorino Siciliano cheese.

PubMed

Randazzo, C L; Pitino, I; De Luca, S; Scifò, G O; Caggia, C

2008-03-20

The effect of six wild strains on the volatile profile of the PS cheese was investigated and compared to that generated from industrial starters generally used to produce PS cheese. All cheeses were subjected to microbiological, physicochemical, and volatile compounds analyses. The DGGE of the 16S rDNA analysis was also applied. The volatile compounds generated during ripening were studied through the SPME and the GC-MS methods. No difference was detected between the experimental and control cheeses throughout chemical and microbiological analyses, while the DGGE results showed the presence of Streptococcus thermophilus in all cheeses, and the dominance of Enterococcus durans, Lactobacillus rhamnosus, and Lactobacillus casei in most of the experimental cheeses. Moreover, the presence of Lactococcus lactis species as in the control and in the experimental P2 and P4 cheeses was also revealed. The SPME results showed more pronounced volatile compounds in the experimental cheese samples than in the control ones.

Performance and Metabolism of Calves Fed Starter Feed Containing Sugarcane Molasses or Glucose Syrup as a Replacement for Corn.

PubMed

Oltramari, C E; Nápoles, G G O; De Paula, M R; Silva, J T; Gallo, M P C; Pasetti, M H O; Bittar, C M M

2016-07-01

The aim of this study was to evaluate the effect of replacing corn grain for sugar cane molasses (MO) or glucose syrup (GS) in the starter concentrate on performance and metabolism of dairy calves. Thirty-six individually housed Holstein male calves were blocked according to weight and date of birth and assigned to one of the starter feed treatments, during an 8 week study: i) starter containing 65% corn with no MO or GS (0MO); ii) starter containing 60% corn and 5% MO (5MO); iii) starter containing 55% corn and 10% MO (10MO); and iv) starter containing 60% corn and 5% GS (5GS). Animals received 4 L of milk replacer daily (20 crude protein, 16 ether extract, 12.5% solids), divided in two meals (0700 and 1700 h). Starter and water were provided ad libitum. Starter intake and fecal score were monitored daily until animals were eight weeks old. Body weight and measurements (withers height, hip width and heart girth) were measured weekly before the morning feeding. From the second week of age, blood samples were collected weekly, 2 h after the morning feeding, for glucose, β-hydroxybutyrate and lactate determination. Ruminal fluid was collected at 4, 6, and 8 weeks of age using an oro-ruminal probe and a suction pump for determination of pH and short-chain fatty acids (SCFA). At the end of the eighth week, animals were harvested to evaluate development of the proximal digestive tract. The composition of the starter did not affect (p>0.05) concentrate intake, weight gain, fecal score, blood parameters, and rumen development. However, treatment 5MO showed higher (p<0.05) total concentration of SCFAs, acetate and propionate than 0MO, and these treatments did not differ from 10MO and 5GS (p>0.05). Thus, it can be concluded that the replacement of corn by 5% or 10% sugar cane molasses or 5% GS on starter concentrate did not impact performance, however it has some positive effects on rumen fermentation which may be beneficial for calves with a developing rumen.

Yeasts from autochthonal cheese starters: technological and functional properties.

PubMed

Binetti, A; Carrasco, M; Reinheimer, J; Suárez, V

2013-08-01

The aim of this work was to identify 20 yeasts isolated from autochthonal cheese starters and evaluate their technological and functional properties. The capacities of the yeasts to grow at different temperatures, pH, NaCl and lactic acid concentrations as well as the proteolytic and lipolytic activities were studied. Moreover, survival to simulated gastrointestinal digestion, hydrophobicity, antimicrobial activity against pathogens and auto- and co-aggregation abilities were evaluated. The sequentiation of a fragment from the 26S rDNA gene indicated that Kluyveromyces marxianus was the predominant species, followed by Saccharomyces cerevisiae, Clavispora lusitaniae, Kluyveromyces lactis and Galactomyces geotrichum. RAPD with primer M13 allowed a good differentiation among strains from the same species. All strains normally grew at pH 4.7-5.5 and temperatures between 15 and 35°C. Most of them tolerated 10% NaCl and 3% lactic acid. Some strains showed proteolytic (eight isolates) and/or lipolytic (four isolates) capacities. All strains evidenced high gastrointestinal resistance, moderate hydrophobicity, intermediate auto-aggregation and variable co-aggregation abilities. No strains inhibited the growth of the pathogens assayed. Some strains from dairy sources showed interesting functional and technological properties. This study has been the first contribution to the identification and characterization of yeasts isolated from autochthonal cheese starters in Argentina. Many strains could be proposed as potential candidates to be used as probiotics and/or as co-starters in cheese productions. © 2013 The Society for Applied Microbiology.

Autochthonous lactic acid bacteria with probiotic aptitudes as starter cultures for fish-based products.

PubMed

Speranza, Barbara; Racioppo, Angela; Beneduce, Luciano; Bevilacqua, Antonio; Sinigaglia, Milena; Corbo, Maria Rosaria

2017-08-01

This study focused on the selection of lactic starters with probiotic properties for the production of fermented fish-products by the use of a multivariate approach (Cluster Analysis and Principal Component Analysis). Seventy-five isolates were recovered from fish intestinal microbiota and characterized by evaluating phenotypical, technological and probiotic traits; the most promising isolates were molecularly identified and then used into fish fermented sausage production. Namely, data from technological characterization were modelled through Growth Index and used as input to run a preliminary selection. Thus, 15 promising strains were selected and subjected to probiotic characterization; considering the results from probiotic tests, 3 promising strains were finally chosen (11, 68 and 69), identified as members of the genus Lactobacillus and used for the validation at laboratory level through the assessment of their performances for the production of fermented fish sausages. The results were promising as the use of the selected strains reduced the fermentation time (2 days) ensuring a good microbiological quality of the final product. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dallas area rapid transit LRT starter line assessment study design. Final research report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shunk, G.A.; Turnbull, K.F.; Lindquist, N.F.

1995-03-01

Light rail transit (LRT) systems have recently been implemented in a number of urban areas throughout the United States and additional projects are in various stages of planning and development. Questions have been raised concerning the impact of these systems on ridership levels, transit operating costs, regional mobility, land use, economic development, energy, air quality, congestion levels, and other factors. The implementation of the Dallas Area Rapid Transit (DART) LRT starter line provides the opportunity to assess the impact of an LRT system in a Southwestern city in the United States. This research project was undertaken to assist with themore » development of a comprehensive study design for assessing the effects of the DART LRT starter line. To accomplish this objective, a review was conducted of before-and-after studies of recent LRT, heavy rail, and high-occupancy vehicle (HOV) projects. The goals and objectives of the DART system were also reviewed and existing transportation-related data collection activities in the Dallas area were examined. This information was used to develop a preliminary study design for assessing the effects of the DART LRT starter line. This report documents the review of recent before-and-after studies and presents the preliminary study design for assessing the effects of the DART LRT starter line.« less

Conducting On-orbit Gene Expression Analysis on ISS: WetLab-2

NASA Technical Reports Server (NTRS)

Parra, Macarena; Almeida, Eduardo; Boone, Travis; Jung, Jimmy; Lera, Matthew P.; Ricco, Antonio; Souza, Kenneth; Wu, Diana; Richey, C. Scott

2013-01-01

WetLab-2 will enable expanded genomic research on orbit by developing tools that support in situ sample collection, processing, and analysis on ISS. This capability will reduce the time-to-results for investigators and define new pathways for discovery on the ISS National Lab. The primary objective is to develop a research platform on ISS that will facilitate real-time quantitative gene expression analysis of biological samples collected on orbit. WetLab-2 will be capable of processing multiple sample types ranging from microbial cultures to animal tissues dissected on orbit. WetLab-2 will significantly expand the analytical capabilities onboard ISS and enhance science return from ISS.

Effects of withdrawal rate and starter block size on crystal orientation of a single crystal Ni-based superalloy

NASA Astrophysics Data System (ADS)

Rezaei, M.; Kermanpur, A.; Sadeghi, F.

2018-03-01

Fabrication of single crystal (SC) Ni-based gas turbine blades with a minimum crystal misorientation has always been a challenge in gas turbine industry, due to its significant influence on high temperature mechanical properties. This paper reports an experimental investigation and numerical simulation of the SC solidification process of a Ni-based superalloy to study effects of withdrawal rate and starter block size on crystal orientation. The results show that the crystal misorientation of the sample with 40 mm starter block height is decreased with increasing withdrawal rate up to about 9 mm/min, beyond which the amount of misorientation is increased. It was found that the withdrawal rate, height of the starter block and temperature gradient are completely inter-dependent and indeed achieving a SC specimen with a minimum misorientation needs careful optimization of these process parameters. The height of starter block was found to have higher impact on crystal orientation compared to the withdrawal rate. A suitable withdrawal rate regime along with a sufficient starter block height was proposed to produce SC parts with the lowest misorientation.

Characterization of Lactobacillus brevis L62 strain, highly tolerant to copper ions.

PubMed

Mrvčić, Jasna; Butorac, Ana; Solić, Ema; Stanzer, Damir; Bačun-Družina, Višnja; Cindrić, Mario; Stehlik-Tomas, Vesna

2013-01-01

Lactic acid bacteria (LAB) as starter culture in food industry must be suitable for large-scale industrial production and possess the ability to survive in unfavorable processes and storage conditions. Approaches taken to address these problems include the selection of stress-resistant strains. In food industry, LAB are often exposed to metal ions induced stress. The interactions between LAB and metal ions are very poorly investigated. Because of that, the influence of non-toxic, toxic and antioxidant metal ions (Zn, Cu, and Mn) on growth, acid production, metal ions binding capacity of wild and adapted species of Leuconostoc mesenteroides L3, Lactobacillus brevis L62 and Lactobacillus plantarum L73 were investigated. The proteomic approach was applied to clarify how the LAB cells, especially the adapted ones, protect themselves and tolerate high concentrations of toxic metal ions. Results have shown that Zn and Mn addition into MRS medium in the investigated concentrations did not have effect on the bacterial growth and acid production, while copper ions were highly toxic, especially in static conditions. Leuc. mesenteroides L3 was the most efficient in Zn binding processes among the chosen LAB species, while L. plantarum L73 accumulated the highest concentration of Mn. L. brevis L62 was the most copper resistant species. Adaptation had a positive effect on growth and acid production of all species in the presence of copper. However, the adapted species incorporated less metal ions than the wild species. The exception was adapted L. brevis L62 that accumulated high concentration of copper ions in static conditions. The obtained results showed that L. brevis L62 is highly tolerant to copper ions, which allows its use as starter culture in fermentative processes in media with high concentration of copper ions.

Digestive development in neonatal dairy calves with either whole or ground oats in the calf starter.

PubMed

Suarez-Mena, F X; Heinrichs, A J; Jones, C M; Hill, T M; Quigley, J D

2015-05-01

A series of 3 trials was conducted to determine effects of whole or ground oats in starter grain on reticulorumen fermentation and digestive system development of preweaned calves. Male Holstein calves (43.1±2.3kg at birth; n=8, 9, and 7 for trials 1, 2, and 3, respectively) were housed in individual pens in a heated facility; bedding was covered with landscape fabric to prevent consumption of bedding by the calves. In trials 1 and 2 only, calves were fitted with rumen cannulas by wk 2 of life. In all trials, a fixed amount of starter (containing 25% oats either ground and in the pellet or whole) was offered daily; orts were fed through the cannula in trials 1 and 2. Calves were randomly assigned to an all-pelleted starter or pellets plus whole oats. Rumen contents (trials 1 and 2) were sampled weekly at -8, -4, 0, 2, 4, 8, and 12 h after grain feeding for determination of pH and volatile fatty acids. Calves were killed 3 wk (trial 1) or 4 wk (trials 2 and 3) after grain was offered; organs were harvested, emptied, rinsed, and weighed to gauge digestive organ development. Starter intake was not different between treatments. Weekly measurements of rumen digesta pH did not change and only subtle changes were observed in molar proportions of individual volatile fatty acids. Molar proportion of butyrate and pH linearly decreased with age, whereas acetate proportion increased. Reticulorumen weight and papillae length tended to be greater for calves fed pelleted starter, whereas abomasum weight was greater for calves fed pellets plus whole oats. Fecal particle size and starch content were greater for calves fed pellets plus whole oats. Under the conditions of this study, physical form of oats in starter grain did not affect rumen fermentation measurements; greater rumen weight and papillae length in calves fed pelleted starter may be the result of greater nutrient availability of ground oats. Under the conditions of this study with young calves on treatments for <4 wk

Evaluation of genetic polymorphism among Lactobacillus rhamnosus non-starter Parmigiano Reggiano cheese strains.

PubMed

Bove, Claudio Giorgio; De Dea Lindner, Juliano; Lazzi, Camilla; Gatti, Monica; Neviani, Erasmo

2011-01-05

Parmigiano Reggiano (PR) is an Italian cooked, long-ripened cheese made with unheated cow's milk and natural whey starter. The microflora is involved in the manufacturing of this cheese, arising from the natural whey starter, the raw milk and the environment. Molecular studies have shown that mesophilic non-starter lactic acid bacteria (NSLAB) are the dominant microflora present during the ripening of PR. In this study, a characterisation of Lactobacillus rhamnosus isolated from a single PR manufacturing and ripening process is reported, using a combination of genotypic fingerprinting techniques (RAPD-PCR and REP-PCR). The intraspecies heterogeneity evidenced for 66 strains is correlated to their abilities to adapt to specific environmental and technological conditions. The detection of biotypes that correlate with specific moments in cheese ripening or differential development throughout this process suggests that these strains may have specific roles closely linked to their peculiar technological properties. Copyright © 2010 Elsevier B.V. All rights reserved.

Influencing cocoa flavour using Pichia kluyveri and Kluyveromyces marxianus in a defined mixed starter culture for cocoa fermentation.

PubMed

Crafack, Michael; Mikkelsen, Morten B; Saerens, Sofie; Knudsen, Morten; Blennow, Andreas; Lowor, Samuel; Takrama, Jemmy; Swiegers, Jan H; Petersen, Gert B; Heimdal, Hanne; Nielsen, Dennis S

2013-10-01

The potential impact of aromatic and pectinolytic yeasts on cocoa flavour was investigated using two defined mixed starter cultures encompassing strains of Pichia kluyveri and Kluyveromyces marxianus for inoculating cocoa beans in small scale tray fermentations. Samples for microbial and metabolite analysis were collected at 12-24 hour intervals during 120 h of fermentation. Yeast isolates were grouped by (GTG)5-based rep-PCR fingerprinting and identified by sequencing of the D1/D2 region of the 26S rRNA gene and the actin gene. Pulsed Field Gel Electrophoresis (PFGE) was conducted on isolates belonging to the species P. kluyveri and K. marxianus to verify strain level identity with the inoculated strains. Furthermore, Denaturing Gradient Gel Electrophoresis (DGGE) was performed to follow yeast and bacterial dynamics over time including the presence of the bacterial inoculum consisting of Lactobacillus fermentum and Acetobacter pasteurianus. Yeast cell counts peaked after 12 h of fermentation with the predominant species being identified as Hanseniaspora opuntiae and Hanseniaspora thailandica. P. kluyveri and K. marxianus were found to compose 9.3% and 13.5% of the yeast population, respectively, after 12 h of fermentation whilst PFGE showed that ~88% of all P. kluyveri isolates and 100% of all K. marxianus isolates were identical to the inoculated strains. Despite never being the dominant yeast species at any stage of fermentation, the un-conched chocolates produced from the two inoculated fermentations were judged by sensory analysis to differ in flavour profile compared to the spontaneously fermented control. This could indicate that yeasts have a greater impact on the sensory qualities of cocoa than previously assumed. © 2013.

The kinetics of the arginine deiminase pathway in the meat starter culture Lactobacillus sakei CTC 494 are pH-dependent.

PubMed

Rimaux, T; Vrancken, G; Pothakos, V; Maes, D; De Vuyst, L; Leroy, F

2011-05-01

Lactobacillus sakei is frequently present as the dominant lactic acid bacterium in spontaneously fermented meat products, demonstrating its competitiveness in and adaptation to the meat environment. Since meat is generally low in carbohydrate content, the ability to utilize other energy sources to generate ATP, such as arginine via the arginine deiminase (ADI) pathway, represents a competitive benefit. In this study, the kinetics of growth and arginine conversion capabilities of Lb. sakei CTC 494 were analyzed, and a model was set up to describe the influence of pH on growth and arginine conversion. A series of in vitro batch fermentations using reconstituted MRS medium at different constant pH values (pH 4.50-pH 7.75) was performed. Arginine conversion through the ADI pathway, which was activated from the stationary growth phase on, resulted in the production of both citrulline and ornithine for all pH conditions tested. However, the pattern and the ratio of the end-products of the ADI pathway were influenced by pH. For certain pH values (between pH 5.0 and 6.5), a further conversion of citrulline into ornithine was found when all arginine was depleted. Characterization of responses of the ADI pathway in Lb. sakei CTC 494 to environmental conditions will allow a better understanding and control of this important starter culture in meat fermentations. Copyright © 2010 Elsevier Ltd. All rights reserved.

Proteolytic enzyme activities in Cheddar cheese juice made using lactococcal starters of differing autolytic properties.

PubMed

Sheehan, A; Cuinn, G O'; Fitzgerald, R J; Wilkinson, M G

2006-04-01

To determine proteolytic enzyme activities released in Cheddar cheese juice manufactured using lactococcal starter strains of differing autolytic properties. The activities of residual chymosin, cell envelope proteinase and a range of intracellular proteolytic enzymes were determined during the first 70 days of ripening when starter lactococci predominate the microbial flora. In general, in cell free extracts (CFE) of the strains, the majority of proteolytic activities was highest for Lactococcus lactis HP, intermediate for L. lactis AM2 and lowest for L. lactis 303. However, in cheese juice, as ripening progressed, released proteolytic activities were highest for the highly autolytic strain L. lactis AM2, intermediate for L. lactis 303 and lowest for L. lactis HP. These results indicate that strain related differences in autolysis influence proteolytic enzyme activities released into Cheddar cheese during ripening. No correlation was found between proteolytic potential of the starter strains measured in CFE prior to cheese manufacture and levels of activities released in cheese juice. The findings further support the importance of autolysis of lactococcal starters in determining the levels of proteolytic activities present in cheese during initial stages of ripening.

An improved process of isomaltooligosaccharide production in kimchi involving the addition of a Leuconostoc starter and sugars.

PubMed

Cho, Seung Kee; Eom, Hyun-Ju; Moon, Jin Seok; Lim, Sae-Bom; Kim, Yong Kook; Lee, Ki Won; Han, Nam Soo

2014-01-17

Isomaltooligosaccharides (IMOs) are α-(1→6)-linked oligodextrans that show a prebiotic effect on Bifidobacterium spp. This study sought to improve IMO synthesis during lactate fermentation in kimchi by inoculating the kimchi fermentation mix with a starter and sugars; the psychrotrophic Leuconostoc citreum KACC 91035 strain with high dextransucrase activity was used as a starter and sucrose (58 mM) and maltose (56 mM) were added as the donor and acceptor for the glucose-transferring reaction of the dextransucrase, respectively. With the addition of both the starter and the sugars and incubation at 10°C, IMOs were produced in kimchi after 3d. Without the starter, the IMO production rate and maximal concentration in kimchi were 15.05 mM/d and 75.27 mM, respectively, whereas with the starter, the rate and concentration increased to 22.04 mM/d and 110.19 mM, respectively. In addition, the sucrose-maltose mix gave an appropriate level of sweetness by releasing fructose and prevented unfavorable polymer synthesis by IMO production. This result suggests that lactic acid bacteria expressing a highly active glycosyltransferase can be used for the synthesis of beneficial oligosaccharides in various fermented foods. © 2013.

High specification starter diets improve the performance of low birth weight pigs to 10 weeks of age.

PubMed

Douglas, S L; Wellock, I; Edwards, S A; Kyriazakis, I

2014-10-01

Piglets born with low birth weights (LBiW) are likely to be lighter at weaning. Starter regimes tailored for pigs of average BW therefore may not be optimal for LBiW nursery performance. The objective was to determine if LBiW pigs benefit from a high specification starter regime and the provision of extra feed (additional allowance of last phase diet of the starter regime) in comparison to a standard commercial regime. Additionally, the effect of starter regime on performance of normal birth weight (NBiW) pigs at weaning was determined and compared to that of LBiW pigs. Finally, the cost effectiveness of the treatments was determined. The experiment was therefore an incomplete 2 × 2 × 2 factorial design, as the provision of extra feed was given only to LBiW pigs (n = 6 replicates per treatment; 5 pigs per replicate). Treatments comprised birth weight (LBiW or NBiW), starter regime (high specification [HS] or standard starter [SS]), and extra feed 3 quantity (yes [YF] or no [NF], for LBiW pigs only; feed 3 corresponded to the last phase diet of the starter regime). At weaning (d 28), pigs were randomly assigned within each birth weight category to treatment groups. Nutritional treatments were fed ad libitum on a kilogram/head basis for approximately 3 wk followed by a common weaner diet fed ad libitum until d 70. Starter regime (P = 0.019), feed 3 amount (P = 0.010), and their interaction (P = 0.029) had an effect on ADG of LBiW pigs from d 28 to 49, with pigs on HS followed by YF (HY) performing best. An improvement in feed conversion ratio (FCR) was noted between d 28 and 49 for pigs fed the additional feed 3 (P = 0.030); between d 49 and 70, the only residual effect seen was of starter regime (P = 0.017) on ADG. In contrast, there was no significant effect of starter regime from d 28 to 70 on ADG, ADFI, or FCR of NBiW pigs. By d 49 and 70, LBiW pigs on regime HY weighed the same as NBiW pigs (d 70 BW; 30.0 vs. 30.6 kg; P = 0.413), with similar growth rates from

Fastener starter tool

NASA Technical Reports Server (NTRS)

Chandler, Faith T. (Inventor); Arnett, Michael C. (Inventor); Garton, Harry L. (Inventor); Valentino, William D. (Inventor)

2003-01-01

A fastener starter tool includes a number of spring retention fingers for retaining a small part, or combination of parts. The tool has an inner housing, which holds the spring retention fingers, a hand grip, and an outer housing configured to slide over the inner housing and the spring retention fingers toward and away from the hand grip, exposing and opening, or respectively, covering and closing, the spring retention fingers. By sliding the outer housing toward (away from) the hand grip, a part can be released from (retained by) the tool. The tool may include replaceable inserts, for retaining parts, such as screws, and configured to limit the torque applied to the part, to prevent cross threading. The inner housing has means to transfer torque from the hand grip to the insert. The tool may include replaceable bits, the inner housing having means for transferring torque to the replaceable bit.

Evaluation of oral microbiology lab curriculum reform.

PubMed

Nie, Min; Gao, Zhen Y; Wu, Xin Y; Jiang, Chen X; Du, Jia H

2015-12-07

According to the updated concept of oral microbiology, the School of Stomatology, Wuhan University, has carried out oral microbiology teaching reforms during the last 5 years. There was no lab curriculum before 2009 except for a theory course of oral microbiology. The school has implemented an innovative curriculum with oral medicine characteristics to strengthen understanding of knowledge, cultivate students' scientific interest and develop their potential, to cultivate the comprehensive ability of students. This study was designed to evaluate the oral microbiology lab curriculum by analyzing student performance and perceptions regarding the curriculum from 2009 to 2013. The lab curriculum adopted modalities for cooperative learning. Students collected dental plaque from each other and isolated the cariogenic bacteria with selective medium plates. Then they purified the enrichment culture medium and identified the cariogenic strains by Gram stain and biochemical tests. Both quantitative and qualitative data for 5 years were analysed in this study. Part One of the current study assessed student performance in the lab from 2009 to 2013. Part Two used qualitative means to assess students' perceptions by an open questionnaire. The 271 study students' grades on oral microbiology improved during the lab curriculum: "A" grades rose from 60.5 to 81.2 %, and "C" grades fell from 28.4 to 6.3 %. All students considered the lab curriculum to be interesting and helpful. Quantitative and qualitative data converge to suggest that the lab curriculum has strengthened students' grasp of important microbiology-related theory, cultivated their scientific interest, and developed their potential and comprehensive abilities. Our student performance and perception data support the continued use of the innovative teaching system. As an extension and complement of the theory course, the oral microbiology lab curriculum appears to improve the quality of oral medicine education and help to

3. PLENUM INTERIOR, SHOWING DRAFT REGULATOR ARRANGEMENT AND STARTER MOTOR. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. PLENUM INTERIOR, SHOWING DRAFT REGULATOR ARRANGEMENT AND STARTER MOTOR. - Hot Springs National Park, Bathhouse Row, Lamar Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

Love the Lab, Hate the Lab Report?

ERIC Educational Resources Information Center

Bjorn, Genevive

2018-01-01

In the author's large, urban high school, enrollment in a laboratory science is mandatory. While the student participation rate for lab activities is over 98%, the turn-in rate for traditional lab reports averages just 35% to 85%. Those students who don't produce a lab report miss a critical opportunity to improve their skills in scientific…

Starting System 2. Repair the Starter Rewind Spring. Student Manual. Small Engine Repair Series. First Edition.

ERIC Educational Resources Information Center

Hill, Pamela

This student manual on repairing the starter rewind spring on a small gas engine is the third of three in an instructional package on the starting system in the Small Engine Repair Series for handicapped students. The stated purpose for the booklet is to help students learn what tools and equipment to use in repairing the starter rewind spring and…

Aerobic Fitness of Starter and Non-Starter Soccer Players in the Champion’s League

PubMed Central

Paraskevas, Giorgos; Hadjicharalambous, Marios

2018-01-01

Abstract To identify individual response patterns in selected aerobic fitness variables of regular starters (ST; N = 7) and non-starters (Non-ST; N = 10), top level professional soccer players were tested for maximal oxygen uptake (VO2max), velocity at 4 mM of lactate (V4), velocity at maximal oxygen uptake (νVO2max) and oxygen pulse (O2-pulse) in July and December following consecutive periods of fixture congestion. V4 was the only variable that increased significantly in December compared to July (15.1 ± 0.5 vs. 14.6 ± 0.5, p = 0.001). There was an almost certain beneficial large mean team change for V4 (ES = 1.2 (0.67; 1.57), 100/0/0), while beneficial mean team changes were less likely for νVO2max and O2-pulse [ES = 0.31 (-0.08; 0.70), 68/30/2 and ES = 0.24 (0.01; 0.49), 64/36/0, respectively] and unclear for VO2max (ES = 0.02 (-0.31; 0.70), 18/69/13). With the exception of V4 where 10 out of 17 players (7 ST and 3 Non-ST) showed positive changes higher than the biological variability, all other variables were characterized by a substantial proportion of changes lower than the biological variability. The present study demonstrated that aerobic fitness variables that require maximal effort may be characterized by greater variability of the individual response pattern compared to that of submaximal aerobic fitness variables irrespective of the accumulated game time. Submaximal aerobic fitness variables appear to be more informative in the physiological evaluation of top level soccer players and this may be an advantage during exposure to periods of consecutive games. PMID:29599863

A new approach for selection of Oenococcus oeni strains in order to produce malolactic starters.

PubMed

Coucheney, Françoise; Desroche, Nicolas; Bou, Magali; Tourdot-Maréchal, Raphaëlle; Dulau, Laurent; Guzzo, Jean

2005-12-15

The lactic acid bacterium Oenococcus oeni, mainly responsible for malolactic fermentation (MLF), is used in new winery process as starter culture for direct inoculation. The difficulty to master MLF according to the wine led us to search a new approach to select effective O. oeni strains. Biochemical and molecular tests were performed in order to characterize three strains of O. oeni selected for malolactic starter elaboration. Malolactic and ATPase activities that appeared as a great interest in MLF were measured and the expression of a small heat shock protein Lo18 was evaluated by immunoblotting and real-time PCR. These results were correlated with the performances of strains in two red wines. Physiological and molecular characteristics of the three strains showed significant differences for the global malolactic activity on intact cell at pH 3.0 and at the level of induction of the small heat shock protein Lo18. These two parameters appeared of interest to evaluate in the ability of O. oeni strains to survive into wine after direct inoculation and to perform MLF. Indeed, a tested strain that presented the highest malolactic activity on intact cells at pH 3.0 and a high level of Lo18 induction showed a high growth rate and a high specific kinetic of malate consumption. The techniques used in this work carry out more quickly and more reliable than usual for the selection of effective strains intended for direct inoculation in wines.

Starter for inductively coupled plasma tube

DOEpatents

Hull, Donald E.; Bieniewski, Thomas M.

1988-01-01

A starter assembly is provided for use with an inductively coupled plasma (ICP) tube to reliably initate a plasma at internal pressures above about 30 microns. A conductive probe is inserted within the inductor coil about the tube and insulated from the tube shield assembly. A capacitive circuit is arranged for momentarily connecting a high voltage radio-frequency generator to the probe while simultaneously energizing the coil. When the plasma is initiated the probe is disconnected from the generator and electrically connected to the shield assembly for operation.

Starter for inductively coupled plasma tube

DOEpatents

Hull, D.E.; Bieniewski, T.M.

1988-08-23

A starter assembly is provided for use with an inductively coupled plasma (ICP) tube to reliably initiate a plasma at internal pressures above about 30 microns. A conductive probe is inserted within the inductor coil about the tube and insulated from the tube shield assembly. A capacitive circuit is arranged for momentarily connecting a high voltage radio-frequency generator to the probe while simultaneously energizing the coil. When the plasma is initiated the probe is disconnected from the generator and electrically connected to the shield assembly for operation. 1 fig.

Antioxidative pyranonigrins in rice mold starters and their suppressive effect on the expression of blood adhesion molecules.

PubMed

Miyake, Yoshiaki; Mochizuki, Mika; Ito, Chihiro; Itoigawa, Masataka; Osawa, Toshihiko

2008-06-01

Antioxidants having a 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity in rice mold starters, which are used for the preparation of various Japanese fermented foods, and their effectiveness against the expression of blood adhesion molecules were examined. An antioxidant was isolated from the rice mold starters used for shochu and identified as pyranonigrin-S (PG-S) by (1)H-NMR, (13)C-NMR, and FAB-MS analyses. It was a derivative of pyranonigrin-A (PG-A), which has been isolated as an antioxidant from the rice mold starters. Pyranonigrins PG-A and PG-S were found to exist in spores on rice mold starters which had been prepared by Aspergillus awamori, A. kawachii, and A. saitoi. PG-S exhibited a higher level of DPPH radical scavenging activity than PG-A. PG-A was found to have a significant suppressive effect on the expression of vascular cell adhesion molecule-1 (VCAM-1) in human umbilical vein endothelial cells (HUVECs) induced by tumor necrosis factor-alpha (TNF-alpha) (P<0.05).

Straw particle size in calf starters: Effects on digestive system development and rumen fermentation.

PubMed

Suarez-Mena, F X; Heinrichs, A J; Jones, C M; Hill, T M; Quigley, J D

2016-01-01

Two trials were conducted to determine effects of straw particle size in calf starter on rumen fermentation and development in calves. Holstein calves (n=17 in trial 1; n=25 in trial 2) were housed in individual pens; bedding (wood shavings) was covered with landscape fabric to completely avoid consumption of bedding. Milk replacer was fed at 12% of birth body weight per day and water offered free choice. Calves were randomly assigned to 4 treatments differing in geometric mean particle length (Xgm) of straw comprising 5% of starter dry matter. Straw was provided within the pellet at manufacture (PS; 0.82 mm Xgm) or mixed with the pellet at time of feeding at Xgm of 3.04 (SS), 7.10 (MS), or 12.7 (LS) mm. Calves (n=12; 3/treatment) in trial 1 were fitted with a rumen cannula by wk 2 of age. A fixed amount of starter that was adjusted with age and orts were fed through the cannula in cannulated calves. Calves were euthanized 6 wk after starter was offered (9 and 7 wk of age for trials 1 and 2, respectively). Rumen digesta pH linearly decreased with age, whereas volatile fatty acid concentration increased with age. Overall pH had a cubic trend with SS lower than that of PS and MS. Molar proportion of acetate decreased with age whereas propionate proportion increased. Overall molar proportions of volatile fatty acids were not affected by diet. Fecal Xgm was not different in spite of changes in diet particle size and rumen digesta of PS being greater than SS, MS, and LS at slaughter. Fecal pH and starch concentration were not affected by diet; however, pH decreased whereas starch content increased with age. Weight of stomach compartments, rumen papillae length and width, and rumen wall thickness did not differ between diets. Omasum weight as a percentage of body weight at harvest linearly decreased as straw particle size increased. Under the conditions of this study, modifying straw particle length in starter grain resulted in minimal rumen fermentation parameter

Evaluation of Petrifilm Lactic Acid Bacteria Plates for Counting Lactic Acid Bacteria in Food.

PubMed

Kanagawa, Satomi; Ohshima, Chihiro; Takahashi, Hajime; Burenqiqige; Kikuchi, Misato; Sato, Fumina; Nakamura, Ayaka; Mohamed, Shimaa M; Kuda, Takashi; Kimura, Bon

2018-06-01

Although lactic acid bacteria (LAB) are used widely as starter cultures in the production of fermented foods, they are also responsible for food decay and deterioration. The undesirable growth of LAB in food causes spoilage, discoloration, and slime formation. Because of these adverse effects, food companies test for the presence of LAB in production areas and processed foods and consistently monitor the behavior of these bacteria. The 3M Petrifilm LAB Count Plates have recently been launched as a time-saving and simple-to-use plate designed for detecting and quantifying LAB. This study compares the abilities of Petrifilm LAB Count Plates and the de Man Rogosa Sharpe (MRS) agar medium to determine the LAB count in a variety of foods and swab samples collected from a food production area. Bacterial strains isolated from Petrifilm LAB Count Plates were identified by 16S rDNA sequence analysis to confirm the specificity of these plates for LAB. The results showed no significant difference in bacterial counts measured by using Petrifilm LAB Count Plates and MRS medium. Furthermore, all colonies growing on Petrifilm LAB Count Plates were confirmed to be LAB, while yeast colonies also formed in MRS medium. Petrifilm LAB Count Plates eliminated the plate preparation and plate inoculation steps, and the cultures could be started as soon as a diluted food sample was available. Food companies are required to establish quality controls and perform tests to check the quality of food products; the use of Petrifilm LAB Count Plates can simplify this testing process for food companies.

30 CFR 75.819 - Motor-starter enclosures; barriers and interlocks.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Motor-starter enclosures; barriers and interlocks. 75.819 Section 75.819 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Underground High...

Physico-chemical characteristics and free fatty acid composition of dry fermented mutton sausages as affected by the use of various combinations of starter cultures and spices.

PubMed

Zhao, Lihua; Jin, Ye; Ma, Changwei; Song, Huanlu; Li, Hui; Wang, Zhenyu; Xiao, Shan

2011-08-01

The microbiological, physico-chemical and free fatty acid composition of dry fermented mutton sausages were determined during ripening and storage. Three sausage mixtures (starter culture [SC], SC and black pepper [SC+BP] and SC, BP and cumin [SC+BP+C]) were compared with a control (CO). In general, the lactic acid bacteria populations in the SC+BP increased significantly to 9 log CFU/g and were higher than the CO (8 log CFU/g) (P<0.05) from fermentation to ripening. The pH values of the SC, SC+BP and SC+BP+C were 4.81, 4.55 and 4.53 respectively, significantly lower (P<0.05) than the CO at the end of fermentation. The water activity (a(w)) in all sausages decreased significantly to 0.88 at Day 7. The total free fatty acid (TFFA) in the treatments increased significantly (P<0.05) during ripening and storage. The levels of MUFA+PUFA/SFA in SC+BP and SC+BP+C at Day 7 were 2.44 and 2.31 respectively, higher than the control (1.65) (P>0.05). Copyright © 2011 Elsevier Ltd. All rights reserved.

Epifluorescence and atomic force microscopy: Two innovative applications for studying phage-host interactions in Lactobacillus helveticus.

PubMed

Zago, Miriam; Scaltriti, Erika; Fornasari, Maria Emanuela; Rivetti, Claudio; Grolli, Stefano; Giraffa, Giorgio; Ramoni, Roberto; Carminati, Domenico

2012-01-01

Bacteriophages attacking lactic acid bacteria (LAB) still represent a crucial problem in industrial dairy fermentations. The consequences of a phage infection against LAB can lead to fermentation delay, alteration of the product quality and, in most severe cases, the product loss. Phage particles enumeration and phage-host interactions are normally evaluated by conventional plaque count assays, but, in many cases, these methods can be unsuccessful. Bacteriophages of Lactobacillus helveticus, a LAB species widely used as dairy starter or probiotic cultures, are often unable to form lysis plaques, thus impairing their enumeration by plate assay. In this study, we used epifluorescence microscopy to enumerate L. helveticus phage particles from phage-infected cultures and Atomic Force Microscopy (AFM) to visualize both phages and bacteria during the different stages of the lytic cycle. Preliminary, we tested the sensitivity of phage counting by epifluorescence microscopy. To this end, phage particles of ΦAQ113, a lytic phage of L. helveticus isolated from a whey starter culture, were stained by SYBR Green I and enumerated by epifluorescence microscopy. Values obtained by the microscopic method were 10 times higher than plate counts, with a lowest sensitivity limit of ≥6log phage/ml. The interaction of phage ΦAQ113 with its host cell L. helveticus Lh1405 was imaged by AFM after 0, 2 and 5h from phage-host adsorption. The lytic cycle was followed by epifluorescence microscopy counting and the concomitant cell wall changes were visualized by AFM imaging. Our results showed that these two methods can be combined for a reliable phage enumeration and for studying phage and host morphology during infection processes, thus giving a complete overview of phage-host interactions in L. helveticus strains involved in dairy productions. Copyright © 2011 Elsevier B.V. All rights reserved.

Low-Cost Jet Fuel Starter Design Study

DTIC Science & Technology

1974-12-02

2G 27 3^ 38 & 39 60 vi WflU I LIST OF TABLES (continued) TABLE NO, 7 D-l I>-2 TITLE PAGE NO, Sea Level Design Point Component...Improvements 60 Turbojet Performance Summary D-3 Turbofan Performance Summary D-5 vii 1 SECTION INTRODUCTION The purpose of this study was to define...temperature difference between the top and bot- tom of the starter, does not begin to have an effect until after 60 seconds from shutdown. The Jet fuel

Bacteria Culture Test: MedlinePlus Lab Test Information

MedlinePlus

... Information → Bacteria Culture Test URL of this page: https://medlineplus.gov/labtests/bacteriaculturetest.html Bacteria Culture Test ... 2017 Mar 4]; [about 3 screens]. Available from: https://labtestsonline.org/understanding/analytes/sputum-culture/tab/test/ ...

Bacterial DNA Detected in Japanese Rice Wines and the Fermentation Starters.

PubMed

Terasaki, Momoka; Fukuyama, Akari; Takahashi, Yurika; Yamada, Masato; Nishida, Hiromi

2017-12-01

As Japanese rice wine (sake) brewing is not done aseptically, bacterial contamination is conceivable during the process of sake production. There are two types of the fermentation starter, sokujo-moto and yamahai-moto (kimoto). We identified bacterial DNA found in various sakes, the sokujo-moto and the yamahai-moto making just after sake yeast addition. Each sake has a unique variety of bacterial DNA not observed in other sakes. Although most bacterial DNA sequences detected in the sokujo-moto were found in sakes of different sake breweries, most bacterial DNA sequences detected in the yamahai-moto at the early stage of the starter fermentation were not detected in any sakes. Our findings demonstrate that various bacteria grow and then die during the process of sake brewing, as indicated by the presence of trace levels of bacterial DNA.

Application of the Chinese steamed bun starter dough (CSB-SD) in breadmaking.

PubMed

Keeratipibul, Suwimon; Luangsakul, Naphatrapi; Otsuka, Shinya; Sakai, Shigeru; Hatano, Yasushi; Tanasupawat, Somboon

2010-01-01

The application of Chinese steamed bun starter dough (CSB-SD) in breadmaking was investigated. The activation of CSB-SD to activate the growth of lactic acid bacteria (LAB) and to increase the number of yeast, prior to making bread, was conducted by mixing CSB-SD with wheat flour and water and then incubating for 24 h. Wheat flour was then substituted by this activated CSB-SD (aCSB-SD) at 10%, 30%, and 50% (w/w) to make bread. Dough and bread properties were studied comparing to the control (without aCSB-SD). From the farinograph results, a high aCSB-SD substitution level resulted in a less stability in dough with a higher degree of softening. Extensigraph results suggested that after aging, all the substituted dough yielded a greater resistance to extension with lower extensibility values than the control. Substitutions with 30% and 50% (w/w) aCSB-SD significantly increased the total CO(2) gas generation. Scanning electron microscopy SEM images of the 30% and 50% (w/w) substituted dough showed a well-developed gluten matrix. The 50% (w/w) substituted breads obtained a greater risen volume, finer crumb grain, and retained more softness after 5-d storage than the control. In addition, both the 30% and 50% (w/w) substituted breads showed a slightly increased mold stability, as compared to the 0% and 10% (w/w) substituted breads. © 2010 Institute of Food Technologists®

Responses to highly active antiretroviral therapy and clinical events in patients with a low CD4 cell count: late presenters vs. late starters.

PubMed

Waters, L; Fisher, M; Anderson, J; Wood, C; Delpech, V; Hill, T; Walsh, J; Orkin, C; Bansi, L; Gompels, M; Phillips, A; Johnson, M; Gilson, R; Easterbrook, P; Leen, C; Porter, K; Gazzard, B; Sabin, C

2011-05-01

We investigated whether adverse responses to highly active antiretroviral therapy (HAART) associated with late HIV presentation are secondary to low CD4 cell count per se or other confounding factors. A longitudinal analysis of the UK Collaborative HIV Cohort (CHIC) Study of individuals starting HAART in 1998-2007 was carried out, comparing late presenters (presenting/starting HAART at a CD4 count <200 cells/μL) with late starters (presenting at a CD4 count>350 cells/μL; starting HAART at a CD4 count<200 cells/μL), using 'ideal starters' (presenting at a CD4 count>350 cells/μL; starting HAART at a CD4 count of 200-350 cells/μL) as a comparator. Virological, immunological and clinical (new AIDS event/death) outcomes at 48 and 96 weeks were analysed, with the analysis being limited to those remaining on HAART for>3 months. A total of 4978 of 9095 individuals starting first-line HAART with HIV RNA>500 HIV-1 RNA copies/mL were included in the analysis: 2741 late presenters, 947 late starters and 1290 ideal starters. Late presenters were more commonly female, heterosexual and Black African. Most started nonnucleoside reverse transcriptase inhibitors (NNRTIs); 48-week virological suppression was similar in late presenters and starters (and marginally lower than in ideal starters); by week 96 differences were reduced and nonsignificant. The median CD4 cell count increase in late presenters was significantly lower than that in late starters (weeks 48 and 96). During year 1, new clinical events were more frequent for late presenters [odds ratio (OR) 2.04; 95% confidence interval (CI) 1.19-3.51; P=0.01]; by year 2, event rates were similar in all groups. Amongst patients who initiate, and remain on, HAART, late presentation is associated with lower rates of virological suppression, blunted CD4 cell count increases and more clinical events compared with late starters in year 1, but similar clinical and immunological outcomes by year 2 to those of both late and ideal

Starting System 1. Check and Replace the Starter Rewind Rope. Student Manual. Small Engine Repair Series. First Edition.

ERIC Educational Resources Information Center

Hill, Pamela

This student manual on checking and replacing the starter rewind rope is the second of three in an instructional package on the starting system in the Small Engine Repair Series for handicapped students. The stated purpose for the booklet is to help students learn what tools and equipment to use in checking and replacing the starter rewind rope…

Polyphasic Microbial Analysis of Traditional Korean Jeung-Pyun Sourdough Fermented with Makgeolli.

PubMed

Lim, Sae Bom; Tingirikari, Jagan Mohan Rao; Kwon, Ye Won; Li, Ling; Kim, Grace E; Han, Nam Soo

2017-02-28

Jeung-pyun, a fermented rice cake, is prepared by fermenting rice sourdough using makgeolli, a traditional Korean rice wine, in the presence of yeast and lactic acid bacteria (LAB). The goal of this study was to conduct biochemical and microbial analyses of five different rice sourdoughs, each fermented with a different commercial makgeolli, using culture-dependent and culture-independent approaches. All sourdough samples fermented with different makgeolli for 6.5 h showed different profiles in pH, total titratable acidity, organic acid concentration, and microbial growth. LAB belonging to different genera were identified based on colony morphology on modified MRS and sourdough bacteria agar medium. PCR-denaturinggradient gel electrophoresis analyses of the five sourdoughs showed different bands corresponding to LAB and yeast. 16S/26S rRNA gene sequence analyses of the samples confirmed that the predominant LAB in the five fermented rice doughs was Lactobacillus plantarum , Lb. pentosus , and Lb. brevis . Various other Lactobacillus spp. and Saccharomyces cerevisiae were common in all five fermented samples. This study provides comprehensive and comparative information on the microflora involved in fermentation of rice sourdough and signifies the need to develop effective starters to enrich the quality of jeung-pyun.

Behavior of Escherichia coli O157:H7 and Listeria monocytogenes during fermentation and storage of camel yogurt.

PubMed

Al-Nabulsi, Anas A; Olaimat, Amin N; Osaili, Tareq M; Ayyash, Mutamed M; Abushelaibi, Aisha; Jaradat, Ziad W; Shaker, Reyad; Al-Taani, Mahmoud; Holley, Richard A

2016-03-01

In addition to its nutritional and therapeutic properties, camel milk has the ability to suppress the growth of a wide range of foodborne pathogens, but there is a lack of information regarding the behavior of these pathogens in products such as yogurt produced from camel milk. The objective of the current study was to investigate the behavior of Listeria monocytogenes and Escherichia coli O157:H7 during manufacture and storage of camel yogurt. Camel milk inoculated with L. monocytogenes and E. coli O157:H7 was fermented at 43° C for 5h using freeze-dried lactic acid bacteria (LAB) starter cultures (Streptococcus thermophilus and Lactobacillus bulgaricus) and stored at 4 or 10 °C for 14 d. Camel milk inoculated with L. monocytogenes and E. coli O157:H7 without starter culture was also prepared. During fermentation, the numbers of L. monocytogenes and E. coli O157:H7 increased 0.3 and 1.6 log cfu/mL, respectively, in the presence of LAB, and by 0.3 and 2.7 log cfu/mL in the absence of LAB. During storage at 4 or 10 °C, L. monocytogenes increased 0.8 to 1.2 log cfu/mL by 14 d in camel milk without LAB, but in the presence of LAB, the numbers of L. monocytogenes were reduced by 1.2 to 1.7 log cfu/mL by 14 d. Further, E. coli O157:H7 numbers in camel milk were reduced by 3.4 to 3.5 log cfu/mL in the absence of LAB, but E. coli O157:H7 was not detected (6.3 log cfu/mL reduction) by 7d in camel yogurt made with LAB and stored at either temperature. Although camel milk contains high concentrations of natural antimicrobials, L. monocytogenes was able to tolerate these compounds in camel yogurt stored at refrigerator temperatures. Therefore, appropriate care should be taken during production of yogurt from camel milk to minimize the potential for postprocess contamination by this and other foodborne pathogens. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Bioconversion Using Lactic Acid Bacteria: Ginsenosides, GABA, and Phenolic Compounds.

PubMed

Lee, Na-Kyoung; Paik, Hyun-Dong

2017-05-28

Lactic acid bacteria (LAB) are used as fermentation starters in vegetable and dairy products and influence the pH and flavors of foods. For many centuries, LAB have been used to manufacture fermented foods; therefore, they are generally regarded as safe. LAB produce various substances, such as lactic acid, β-glucosidase, and β-galactosidase, making them useful as fermentation starters. Existing functional substances have been assessed as fermentation substrates for better component bioavailability or other functions. Representative materials that were bioconverted using LAB have been reported and include minor ginsenosides, γ-aminobutyric acid, equol, aglycones, bioactive isoflavones, genistein, and daidzein, among others. Fermentation mainly involves polyphenol and polysaccharide substrates and is conducted using bacterial strains such as Streptococcus thermophilus, Lactobacillus plantarum, and Bifidobacterium sp. In this review, we summarize recent studies of bioconversion using LAB and discuss future directions for this field.

An experimental evaluation of the performance deficit of an aircraft engine starter turbine

NASA Technical Reports Server (NTRS)

Haas, J. E.; Roelke, R. J.; Hermann, P.

1980-01-01

An experimental investigation is presented to determine the aerodynamic performance deficit of a 13.5 - centimeter-tip-diameter aircraft engine starter turbine. The two-phased evaluation comprised both the stator and the stage performance, and the experimental design is described in detail. Data obtained from the investigation of three honeycomb shrouds clearly showed that the filled honeycomb reached a total efficiency of 0.868, 8.2 points higher than the open honeycomb shroud, at design equivalent conditions of speed and blade-jet speed ratio. It was concluded that the use of an open honeycomb shroud caused the large performance deficit for the starter turbine. Further research is suggested to ascertain stator inlet boundary layer measurements.

Development of Safe and Flavor-Rich Doenjang (Korean Fermented Soybean Paste) Using Autochthonous Mixed Starters at the Pilot Plant Scale.

PubMed

Lee, Eun Jin; Hyun, Jiye; Choi, Yong-Ho; Hurh, Byung-Serk; Choi, Sang-Ho; Lee, Inhyung

2018-06-01

Doenjang (Korean fermented soybean paste) with an improved flavor and safety was prepared by the simultaneous fermentation of autochthonous mixed starters at the pilot plan scale. First, whole soybean meju was fermented by coculturing safety-verified starters Aspergillus oryzae MJS14 and Bacillus amyloliquefaciens zip6 or Bacillus subtilis D119C. These fermented whole soybean meju were aged in a brine solution after the additional inoculation of Tetragenococcus halophilus 7BDE22 and Zygosaccharomyces rouxii SMY045 to yield doenjang. Four doenjang batches prepared using a combination of mold, bacilli, lactic acid bacteria, and yeast starters were free of safety issues and had the general properties of traditional doenjang, a rich flavor and taste. All doenjang batches received a high consumer acceptability score, especially the ABsT and ABsTZ batches. This study suggests that flavor-rich doenjang similar to traditional doenjang can be manufactured safely and reproducibly in industry by mimicking the simultaneous fermentation of autochthonous mixed starters as in traditional doenjang fermentation. The development of a pilot plant process for doenjang fermentation using safety-verified autochthonous mixed starter will facilitate the manufacture of flavor-rich doenjang similar to traditional doenjang safely and reproducibly in industry. © 2018 Institute of Food Technologists®.

Isolation of Penicillium nalgiovense strains impaired in penicillin production by disruption of the pcbAB gene and application as starters on cured meat products.

PubMed

Laich, Federico; Fierro, Francisco; Martin, Juan F

2003-06-01

The presence of some fungi on a variety of food products, like cheeses or cured meat products, is beneficial for the ripening of the product and for the development of specific flavour features. The utilization of these fungi as starters, which are inoculated normally as asexual spores on the food products at the beginning of the ripening process, is becoming a usual procedure in the food industry. The starter culture also prevents undesirable fungi or bacteria from growing on the product. Penicillium nalgiovense is the most frequently used starter for cured and fermented meat products, but the fact that this fungus can secrete penicillin to the meat product makes it important to get strains unable to synthesize this antibiotic. In this work we report that P. nalgiovense strains impaired in penicillin production can be obtained by disruption of the pcbAB gene (the first gene of the penicillin biosynthetic pathway). When applied as starter on cecina (a salted, smoke-cured beef meat product from the region of León, Spain), the pcbAB-disrupted strain showed no differences with respect to the parental penicillin-producing strain in its ability to colonize the meat pieces and to control their normal mycoflora. Both strains exerted a similar control on the presence of bacteria in cecina. A similar proportion of penicillin-sensitive and penicillin-resistant bacteria were isolated from pieces inoculated with the penicillin-producing or the non-producing P. nalgiovense strains. The decrease of the bacterial population on the surface of cecina seems to be due to the higher competition for nutrients as a consequence of the inoculation and development of the P. nalgiovense mycelium and not due to the production of penicillin by this fungus. Penicillin production was less affected than growth in a solid medium with high NaCl concentrations; this suggests that the high salt concentration present in cecina is not a limiting factor for penicillin production by P. nalgiovense.

Inside Linden Lab: Second Life [TM] for Educators

ERIC Educational Resources Information Center

Atkinson, Tom

2008-01-01

A new culture called Second Life [TM] has emerged that promises innovative strategies for everything from social interactions to business. Some educators believe it may hold new and unique opportunities for teaching and learning. Second Life [TM] (SL) is the creation of Linden Labs, a San Francisco-based corporation defined by its creators as "an…

Effects of starter nitrogen fertilizer on soybean root activity, leaf photosynthesis and grain yield

PubMed Central

Gai, Zhijia; Zhang, Jingtao; Li, Caifeng

2017-01-01

The objective of this study was to examine the impact of starter nitrogen fertilizer on soybean root activity, leaf photosynthesis, grain yield and their relationship. To achieve this objective, field experiments were conducted in 2013 and 2014, using a randomized complete block design, with three replications. Nitrogen was applied at planting at rates of 0, 25, 50, and 75 kg N ha-1. In both years, starter nitrogen fertilizer benefited root activity, leaf photosynthesis, and consequently its yield. Statistically significant correlation was found among root activity, leaf photosynthetic rate, and grain yield at the developmental stage. The application of N25, N50, and N75 increased grain yield by 1.28%, 2.47%, and 1.58% in 2013 and by 0.62%, 2.77%, and 2.06% in 2014 compared to the N0 treatment. Maximum grain yield of 3238.91 kg ha-1 in 2013 and 3086.87 kg ha-1 in 2014 were recorded for N50 treatment. Grain yield was greater for 2013 than 2014, possibly due to more favorable environmental conditions. This research indicated that applying nitrogen as starter is necessary to increase soybean yield in Sangjiang River Plain in China. PMID:28388620

Berkeley Lab Training

Science.gov Websites

Berkeley Lab Berkeley Lab A-Z Index Phone Book Jobs Search DOE Help Berkeley Lab Training Welcome Welcome to Berkeley Lab Training! Login to access your LBNL Training Profile. This provides quick access to all of the courses you need. Look below, to learn about different types of training available at

A Case Study of a High School Fab Lab

NASA Astrophysics Data System (ADS)

Lacy, Jennifer E.

This dissertation examines making and design-based STEM education in a formal makerspace. It focuses on how the design and implementation of a Fab Lab learning environment and curriculum affect how instructors and students see themselves engaging in science, and how the Fab Lab relates to the social sorting practices that already take place at North High School. While there is research examining design-based STEM education in informal and formal learning environments, we know little about how K-12 teachers define STEM in making activities when no university or museum partnership exists. This study sought to help fill this gap in the research literature. This case study of a formal makerspace followed instructors and students in one introductory Fab Lab course for one semester. Additional observations of an introductory woodworking course helped build the case and set it into the school context, and provided supplementary material to better understand the similarities and differences between the Fab Lab course and a more traditional design-based learning course. Using evidence from observational field notes, participant interviews, course materials, and student work, I found that the North Fab Lab relies on artifacts and rhetoric symbolic of science and STEM to set itself apart from other design-based courses at North High School. Secondly, the North Fab Lab instructors and students were unable to explain how what they were doing in the Fab Lab was science, and instead relied on vague and unsupported claims related to interdisciplinary STEM practices and dated descriptions of science. Lastly, the design and implementation of the Fab Lab learning environment and curriculum and its separation from North High School's low tech, design-based courses effectively reinforced social sorting practices and cultural assumptions about student work and intelligence.

A Lab with a View: American Postdocs Abroad

ERIC Educational Resources Information Center

Gladfelter, Amy

2002-01-01

As recently as the early 1970s, a postdoctoral research experience overseas was a valued part of training for a U.S. biologist aspiring to an academic position. Not only did the U.S. scientists benefit educationally from participating in different laboratory and cultural systems, but labs outside the United States were enriched by the ideas,…

Subsequent bone and metabolic responses of broilers to high-non-phytate phosphorus diets in the starter period.

PubMed

Baradaran, N; Shahir, M H; Asadi Kermani, Z

2017-08-01

1. An experiment was performed to elucidate the subsequent effects of high-non-phytate phosphorus (NPP) diets on growth performance, blood metabolites, bone characteristics and P retention of broilers fed on low-NPP grower diets. The 42-d study was designed as a 2 × 2 × 2 + 1 factorial, which included two starter NPP concentrations (4.5 and 5.5 g/kg; d 0-21), two grower NPP concentrations (1.5 and 2.3 g/kg; d 22-42), with or without phytase (1000 FTU/kg), with a reference diet containing an adequate NPP concentration over the course of the trial. 2. In the starter period, growth performance and P retention were not affected by experimental diets. The high-NPP diet increased plasma P concentration, increased tibia ash and tibia P contents and decreased plasma alkaline phosphatase (ALP) activity at d 21. 3. No significant interaction was observed between NPP concentrations in the starter and grower periods and phytase. The main effect data indicated that the increase in NPP concentration in the starter diets had no effects on growth performance in the grower period and overall. The high-NPP diet in the early stage of growth reduced plasma P concentration, plasma ALP activity and tibia ash content at d 42. The main effect data also showed that exogenous phytase increased body weight gain in the grower period and overall. 4. It can be concluded that feeding increased NPP diets have no effects on growth performance in the starter period. This feeding strategy results in negative effects on plasma P concentration and bone ash content at d 42. Also, exogenous phytase is effective in improving growth performance, bone characteristics and apparent P retention of growing broilers fed diets that are inadequate in phosphorus.

Biodiversity in Oscypek, a Traditional Polish Cheese, Determined by Culture-Dependent and -Independent Approaches

PubMed Central

Alegría, Ángel; Szczesny, Pawel; Mayo, Baltasar; Bardowski, Jacek

2012-01-01

Oscypek is a traditional Polish scalded-smoked cheese, with a protected-designation-of-origin (PDO) status, manufactured from raw sheep's milk without starter cultures in the Tatra Mountains region of Poland. This study was undertaken in order to gain insight into the microbiota that develops and evolves during the manufacture and ripening stages of Oscypek. To this end, we made use of both culturing and the culture-independent methods of PCR followed by denaturing gradient gel electrophoresis (PCR-DGGE) and pyrosequencing of 16S rRNA gene amplicons. The culture-dependent technique and PCR-DGGE fingerprinting detected the predominant microorganisms in traditional Oscypek, whereas the next-generation sequencing technique (454 pyrosequencing) revealed greater bacterial diversity. Besides members of the most abundant bacterial genera in dairy products, e.g., Lactococcus, Lactobacillus, Leuconostoc, Streptococcus, and Enterococcus, identified by all three methods, other, subdominant bacteria belonging to the families Bifidobacteriaceae and Moraxellaceae (mostly Enhydrobacter), as well as various minor bacteria, were identified by pyrosequencing. The presence of bifidobacterial sequences in a cheese system is reported for the first time. In addition to bacteria, a great diversity of yeast species was demonstrated in Oscypek by the PCR-DGGE method. Culturing methods enabled the determination of a number of viable microorganisms from different microbial groups and their isolation for potential future applications in specific cheese starter cultures. PMID:22247135

From physiology to systems metabolic engineering for the production of biochemicals by lactic acid bacteria.

PubMed

Gaspar, Paula; Carvalho, Ana L; Vinga, Susana; Santos, Helena; Neves, Ana Rute

2013-11-01

The lactic acid bacteria (LAB) are a functionally related group of low-GC Gram-positive bacteria known essentially for their roles in bioprocessing of foods and animal feeds. Due to extensive industrial use and enormous economical value, LAB have been intensively studied and a large body of comprehensive data on their metabolism and genetics was generated throughout the years. This knowledge has been instrumental in the implementation of successful applications in the food industry, such as the selection of robust starter cultures with desired phenotypic traits. The advent of genomics, functional genomics and high-throughput experimentation combined with powerful computational tools currently allows for a systems level understanding of these food industry workhorses. The technological developments in the last decade have provided the foundation for the use of LAB in applications beyond the classic food fermentations. Here we discuss recent metabolic engineering strategies to improve particular cellular traits of LAB and to design LAB cell factories for the bioproduction of added value chemicals. Copyright © 2013 Elsevier Inc. All rights reserved.

Persistence of wild Streptococcus thermophilus strains on wooden vat and during the manufacture of a traditional Caciocavallo type cheese.

PubMed

Settanni, L; Di Grigoli, A; Tornambé, G; Bellina, V; Francesca, N; Moschetti, G; Bonanno, A

2012-04-02

The present work was undertaken to evaluate the influence of the wooden dairy plant equipment on the microbiological characteristics of curd to be transformed into Caciocavallo Palermitano cheese. Traditional raw milk productions were performed concomitantly with standard cheese making trials carried out in stainless steel vat inoculated with a commercial starter. Milk from two different farms (A and B) was separately processed. The wooden vat was found to be a reservoir of lactic acid bacteria (LAB), while unwanted (spoilage and/or pathogenic) microorganisms were not hosted or were present at very low levels. All microbial groups were numerically different in bulk milks, showing higher levels for the farm B. LAB, especially thermophilic cocci, dominated the whole cheese making process of all productions. Undesired microorganisms decreased in number or disappeared during transformation, particularly after curd stretching. LAB were isolated from the wooden vat surface and from all dairy samples, subjected to phenotypic and genetic characterization and identification. Streptococcus thermophilus was the species found at the highest concentration in all samples analyzed and it also dominated the microbial community of the wooden vat. Fourteen other LAB species belonging to six genera (Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Streptococcus and Weissella) were also detected. All S. thermophilus isolates were genetically differentiated and a consortium of four strains persisted during the whole traditional production process. As confirmed by pH and the total acidity after the acidification step, indigenous S. thermophilus strains acted as a mixed starter culture. Copyright © 2012 Elsevier B.V. All rights reserved.

Fermentation pH influences the physiological-state dynamics of Lactobacillus bulgaricus CFL1 during pH-controlled culture.

PubMed

Rault, Aline; Bouix, Marielle; Béal, Catherine

2009-07-01

This study aims at better understanding the effects of fermentation pH and harvesting time on Lactobacillus bulgaricus CFL1 cellular state in order to improve knowledge of the dynamics of the physiological state and to better manage starter production. The Cinac system and multiparametric flow cytometry were used to characterize and compare the progress of the physiological events that occurred during pH 6 and pH 5 controlled cultures. Acidification activity, membrane damage, enzymatic activity, cellular depolarization, intracellular pH, and pH gradient were determined and compared during growing conditions. Strong differences in the time course of viability, membrane integrity, and acidification activity were displayed between pH 6 and pH 5 cultures. As a main result, the pH 5 control during fermentation allowed the cells to maintain a more robust physiological state, with high viability and stable acidification activity throughout growth, in opposition to a viability decrease and fluctuation of activity at pH 6. This result was mainly explained by differences in lactate concentration in the culture medium and in pH gradient value. The elevated content of the ionic lactate form at high pH values damaged membrane integrity that led to a viability decrease. In contrast, the high pH gradient observed throughout pH 5 cultures was associated with an increased energetic level that helped the cells maintain their physiological state. Such results may benefit industrial starter producers and fermented-product manufacturers by allowing them to better control the quality of their starters, before freezing or before using them for food fermentation.

Effects of raw milk and starter feed on intake and body composition of Holstein × Gyr male calves up to 64 days of age.

PubMed

Silva, A L; Marcondes, M I; Detmann, E; Machado, F S; Valadares Filho, S C; Trece, A S; Dijkstra, J

2015-04-01

The objective was to evaluate the effect of supplying different levels of raw milk, alone or in combination, with access to a starter feed, on the intake, digestibility, daily gain, N balance, and body composition of Holstein × Gyr crossbred suckling calves until 64 d of age. Thirty-nine male calves aged 4 d with an average initial live weight of 36 ± 1.0 kg were used. Five calves were defined as a reference group and slaughtered at 4 d of age to estimate the initial body composition of the animals. The other calves were distributed according to a completely randomized design in a 3 × 2 factorial arrangement consisting of 3 levels of milk (2, 4, or 8 L/d) and 2 levels of starter feed (presence or absence in diet). At 15 and 45 d of age, 4 animals from each treatment were subjected to digestibility trials with total collection of feces and urine and sampling of feeds. At 64 d of age, all animals were slaughtered and their body tissues were sampled for analyses. Total dry matter and nutrient intake increased linearly and starter intake decreased linearly in response to the supply of increasing amounts of milk. The digestibility coefficient of organic matter was not affected by the inclusion of starter feed and increased linearly as milk supply was elevated. Daily gain was greater at increased milk supply levels and also greater when starter was supplied, without any interaction between milk supply level and the presence or absence of starter. Fecal N excretion and N retention were higher in the animals fed starter feed. Fecal N excretion was not affected by milk levels, whereas N retention was affected. Body protein and ash contents decreased linearly according to increased milk allowance. In contrast, fat body content increased linearly according to milk supply. The presence of starter feed in the diet was responsible for the increased body fat content, but had no effect on protein or ash content. In conclusion, weight gain and N retention in calves up to 64 d of

The importance of calf sensory and physical preferences for starter concentrates during pre- and postweaning periods.

PubMed

Terré, M; Devant, M; Bach, A

2016-09-01

We performed 3 studies to evaluate the effects of feed sensory and form preferences in young calves on performance and rumen fermentation dynamics. In experiment 1, starter feeds containing wheat and soybean meal; wheat and canola meal; and oats and soybean meal were evaluated in 63 calves (9±0.9 d old). In experiment 2, 37 crossbreed female calves were used from 4 to 45 d of age (weaning) in a cafeteria study consisting of 4 different presentations of the same starter feed: meal, pellet, pellet mixed with whole-cereal grains (WHG), and pellet mixed with steamed-rolled cereal grains (SRG). In experiment 3, 63 Holstein male calves (10±1.03 d old) were randomly distributed to 2 treatments that consisted of feeding a pellet concentrate mixed with whole corn and barely grains (WHG) or the same pellet concentrate mixed with steamed-rolled corn and barley grains (SRG). In experiment 1, animals in all 3 treatments had similar intake and performance, and we found no differences in rumen fermentation parameters. In experiment 2, during the first week of study, calves had a greater preference for WHG; after the first week, calves had a greater preference for SRG. In experiment 3, starter concentrate intake was greater in WHG than in SRG concentrates between wk 5 and weaning. However, we observed no differences in growth or gain-to-feed ratio. Calves offered WHG concentrates had greater rumen pH and tended to have lower total rumen volatile fatty acid concentrations than those offered SRG concentrates. We concluded that preweaned calves preferred concentrates based on pellets mixed with steamed-rolled grains. When calves could not choose their starter feed, pellets mixed with steamed-rolled grains reduced concentrate intake and rumen pH compared to pellets mixed with whole grains, but performance was not impaired. Formulating starter concentrates according to calves' sensory and physical preferences had little effect on performance. Copyright © 2016 American Dairy Science

(De)Constructing the Undergraduate Research Experience in an Environmental Geochemistry Lab (Invited)

NASA Astrophysics Data System (ADS)

Kim, C. S.

2013-12-01

Maintaining a productive research lab at the undergraduate level requires a savvy combination of internal organization, high (but realistic) expectations, and adaptation of one's research interests into semester- and summer-length projects. Several key strategies can help achieve the goal of building a lab culture that both enriches students' academic experiences and advances one's own scholarly research and visibility. Foremost among these is the need to maintain momentum and preserve institutional knowledge in an environment where undergraduate students' lifetime in an individual lab may only last a year or two. Examples from the Environmental Geochemistry Lab at Chapman University (www.chapman.edu/envgeo) developed over several years and with 40+ undergraduate students will be presented which can be transferable to other faculty research labs in the earth sciences. Approaches to writing successful external research grant proposals at a primarily undergraduate institution (PUI) and strategies for both personal and institutional time management/savings will also be discussed, with a focus on new models at Chapman offered to further incentivize faculty involvement in undergraduate research.

Multilayer based lab-on-a-chip-systems for substance testing

NASA Astrophysics Data System (ADS)

Sonntag, Frank; Grünzner, Stefan; Schmieder, Florian; Busek, Mathias; Klotzbach, Udo; Franke, Volker

2015-03-01

An integrated technology chain for laser-microstructuring and bonding of polymer foils for fast, flexible and low-cost manufacturing of multilayer lab-on-a-chip devices especially for complex cell and tissue culture applications, which provides pulsatile fluid flow within physiological ranges at low media-to-cells ratio, was developed and established. Initially the microfluidic system is constructively divided into individual layers which are formed by separate foils or plates. Based on the functional boundary conditions and the necessary properties of each layer the corresponding foils and plates are chosen. In the third step the foils and plates are laser microstructured and functionalized from both sides. In the fourth and last manufacturing step the multiple plates and foils are joined using thermal diffusion bonding. Membranes for pneumatically driven valves and micropumps where bonded via chemical surface modification. Based on the established lab-on-a-chip platform for perfused cell-based assays, a multilayer microfluidic system with two parallel connected cell culture chambers was successfully implemented.

Hyperconcentrated Sweet Whey, a New Culture Medium That Enhances Propionibacterium freudenreichii Stress Tolerance

PubMed Central

Huang, Song; Rabah, Houem; Jardin, Julien; Briard-Bion, Valérie; Parayre, Sandrine; Maillard, Marie-Bernadette; Le Loir, Yves; Schuck, Pierre; Jeantet, Romain

2016-01-01

ABSTRACT Propionibacterium freudenreichii is used as a cheese-ripening starter and as a probiotic. Its reported physiological effects at the gut level, including modulation of bifidobacteria, colon epithelial cell proliferation and apoptosis, and intestinal inflammation, rely on active metabolism in situ. Survival and activity are thus key factors determining its efficacy, creating stress adaptation and tolerance bottlenecks for probiotic applications. Growth media and growth conditions determine tolerance acquisition. We investigated the possibility of using sweet whey, a dairy by-product, to sustain P. freudenreichii growth. It was used at different concentrations (dry matter) as a culture medium. Using hyperconcentrated sweet whey led to enhanced multistress tolerance acquisition, overexpression of key stress proteins, and accumulation of intracellular storage molecules and compatible solutes, as well as enhanced survival upon spray drying. A simplified process from growth to spray drying of propionibacteria was developed using sweet whey as a 2-in-1 medium to both culture P. freudenreichii and protect it from heat and osmotic injury without harvesting and washing steps. As spray drying is far cheaper and more energy efficient than freeze-drying, this work opens new perspectives for the sustainable development of new starter and probiotic preparations with enhanced robustness. IMPORTANCE In this study, we demonstrate that sweet whey, a dairy industry by-product, not only allows the growth of probiotic dairy propionibacteria, but also triggers a multitolerance response through osmoadaptation and general stress response. We also show that propionibacteria accumulate compatible solutes under these culture conditions, which might account for the limited loss of viability after spray drying. This work opens new perspectives for more energy-efficient production of dairy starters and probiotics. PMID:27235433

Away with Good Bantus: De-Linking African Language Literature from Culture, "Tribe" and Propriety

ERIC Educational Resources Information Center

Mkhize, Nomalanga

2016-01-01

This paper argues that the "institutionalisation" model used by universities to spearhead the intellectualisation of African languages is a non-starter for taking African languages in new creative directions. The major constraint for African language literary culture is that written output has historically been heavily bent towards…

Fermented Apulian table olives: Effect of selected microbial starters on polyphenols composition, antioxidant activities and bioaccessibility.

PubMed

D'Antuono, Isabella; Bruno, Angelica; Linsalata, Vito; Minervini, Fiorenza; Garbetta, Antonella; Tufariello, Maria; Mita, Giovanni; Logrieco, Antonio F; Bleve, Gianluca; Cardinali, Angela

2018-05-15

The effects of fermentation by autochthonous microbial starters on phenolics composition of Apulian table olives, Bella di Cerignola (BDC), Termite di Bitetto (TDB) and Cellina di Nardò (CEL) were studied, highlighting also the cultivars influence. In BDC with starter, polyphenols amount doubled compared with commercial sample, while in TDB and CEL, phenolics remain almost unchanged. The main phenolics were hydroxytyrosol, tyrosol, verbascoside and luteolin, followed by hydroxytyrosol-acetate detected in BDC and cyanidine-3-glucoside and quercetin in CEL. Scavenger capacity in both DPPH and CAA assays, assessed the highest antioxidant effect for CEL with starters (21.7 mg Trolox eq/g FW; 8.5 μmol hydroxytyrosol eq/100 g FW). The polyphenols were highly in vitro bioaccessible (>60%), although modifications in their profile, probably for combined effect of environment and microorganisms, were noted. Finally, fermented table olives are excellent source of health promoting compounds, since hydroxytyrosol and tyrosol are almost 8 times more than in olive oil. Copyright © 2017 Elsevier Ltd. All rights reserved.

In vitro assessment of Pediococcus acidilactici Kp10 for its potential use in the food industry.

PubMed

Abbasiliasi, Sahar; Tan, Joo Shun; Bashokouh, Fatemeh; Ibrahim, Tengku Azmi Tengku; Mustafa, Shuhaimi; Vakhshiteh, Faezeh; Sivasamboo, Subhashini; Ariff, Arbakariya B

2017-05-23

Selection of a microbial strain for the incorporation into food products requires in vitro and in vivo evaluations. A bacteriocin-producing lactic acid bacterium (LAB), Pediococcus acidilactici Kp10, isolated from a traditional dried curd was assessed in vitro for its beneficial properties as a potential probiotic and starter culture. The inhibitory spectra of the bacterial strain against different gram-positive and gram-negative bacteria, its cell surface hydrophobicity and resistance to phenol, its haemolytic, amylolytic and proteolytic activities, ability to produce acid and coagulate milk together with its enzymatic characteristics and adhesion property were all evaluated in vitro. P. acidilactici Kp10 was moderately tolerant to phenol and adhere to mammalian epithelial cells (Vero cells and ileal mucosal epithelium). The bacterium also exhibited antimicrobial activity against several gram-positive and gram-negative food-spoilage and food-borne pathogens such as Listeria monocytgenes ATCC 15313, Salmonella enterica ATCC 13311, Shigella sonnei ATCC 9290, Klebsiella oxytoca ATCC 13182, Enterobacter cloaca ATCC 35030 and Streptococcus pyogenes ATCC 12378. The absence of haemolytic activity and proteinase (trypsin) and the presence of a strong peptidase (leucine-arylamidase) and esterase-lipase (C4 and C8) were observed in this LAB strain. P. acidilactici Kp10 also produced acid, coagulated milk and has demonstrated proteolytic and amylolactic activities. The properties exhibited by P. acidilactici Kp10 suggested its potential application as probiotic and starter culture in the food industry.

e-Learning - Physics Labs

NASA Astrophysics Data System (ADS)

Mohottala, Hashini

2014-03-01

The general student population enrolled in any college level class is highly diverse. An increasing number of ``nontraditional'' students return to college and most of these students follow distance learning degree programs while engaging in their other commitments, work and family. However, those students tend to avoid taking science courses with labs, mostly because of the incapability of remotely completing the lab components in such courses. In order to address this issue, we have come across a method where introductory level physics labs can be taught remotely. In this process a lab kit with the critical lab components that can be easily accessible are conveniently packed into a box and distributed among students at the beginning of the semester. Once the students are given the apparatus they perform the experiments at home and gather data All communications with reference to the lab was done through an interactive user-friendly webpage - Wikispaces (WikiS). Students who create pages on WikiS can submit their lab write-ups, embed videos of the experiments they perform, post pictures and direct questions to the lab instructor. The students who are enrolled in the same lab can interact with each other through WikiS to discuss labs and even get assistance.

Application of bacteriocins in vegetable food biopreservation.

PubMed

Settanni, Luca; Corsetti, Aldo

2008-01-31

Bacteriocins are generally recognized as "natural" compounds able to influence the safety and quality of foods. In the past years, a lot of works have been aimed to the detection, purification and characterisation of bacteriocins, as well as to their use in food preservation strategies. A list of review articles dealing with the application of bacteriocins to the protection of foods of animal origin is also available in literature, but it lacks for a summary on the utilization of bacteriocins in vegetable foods. These biopreservatives can be used in a number of ways in food systems and this paper mainly focuses on the state-of-the-art application of bacteriocins from lactic acid bacteria (LAB) to promote the microbial stability of both fermented and non-fermented vegetable food products using bacteriocinogenic strains as starter cultures, protective cultures or co-cultures and the employment of pure bacteriocins as food additives. In addition, applications of bacteriocins from non-LAB are also reviewed. The scopes of future directions of research are summarised.

Lab-on-a-Chip Pathogen Sensors for Food Safety

PubMed Central

Yoon, Jeong-Yeol; Kim, Bumsang

2012-01-01

There have been a number of cases of foodborne illness among humans that are caused by pathogens such as Escherichia coli O157:H7, Salmonella typhimurium, etc. The current practices to detect such pathogenic agents are cell culturing, immunoassays, or polymerase chain reactions (PCRs). These methods are essentially laboratory-based methods that are not at all real-time and thus unavailable for early-monitoring of such pathogens. They are also very difficult to implement in the field. Lab-on-a-chip biosensors, however, have a strong potential to be used in the field since they can be miniaturized and automated; they are also potentially fast and very sensitive. These lab-on-a-chip biosensors can detect pathogens in farms, packaging/processing facilities, delivery/distribution systems, and at the consumer level. There are still several issues to be resolved before applying these lab-on-a-chip sensors to field applications, including the pre-treatment of a sample, proper storage of reagents, full integration into a battery-powered system, and demonstration of very high sensitivity, which are addressed in this review article. Several different types of lab-on-a-chip biosensors, including immunoassay- and PCR-based, have been developed and tested for detecting foodborne pathogens. Their assay performance, including detection limit and assay time, are also summarized. Finally, the use of optical fibers or optical waveguide is discussed as a means to improve the portability and sensitivity of lab-on-a-chip pathogen sensors. PMID:23112625

Adding Value to Goat Meat: Biochemical and Technological Characterization of Autochthonous Lactic Acid Bacteria to Achieve High-Quality Fermented Sausages

PubMed Central

Nediani, Miriam T.; García, Luis; Saavedra, Lucila; Martínez, Sandra; López Alzogaray, Soledad; Fadda, Silvina

2017-01-01

Quality and safety are important challenges in traditional fermented sausage technology. Consequently, the development of a tailored starter culture based on indigenous microbiota constitutes an interesting alternative. In the present study, spontaneously fermented goat meat sausages were created and analyzed using a physicochemical and microbiological approach. Thereafter 170 lactic acid bacteria (LAB) strains were isolated and preliminary characterized by phenotypic assays. The hygienic and technological properties, and growth and fermentative potential of isolates using a goat-meat-based culture medium were evaluated. All strains proved to have bioprotective features due to their acidogenic metabolism. Almost all grew optimally in meat environments. LAB isolates presented proteolytic activity against meat proteins and enriched amino acid contents of the goat-meat-based model. The most efficient strains were four different Lactobacillus sakei isolates, as identified by genotyping and RAPD analysis. L. sakei strains are proposed as optimal candidates to improve the production of fermented goat meat sausages, creating a new added-value fermented product. PMID:28513575

Adding Value to Goat Meat: Biochemical and Technological Characterization of Autochthonous Lactic Acid Bacteria to Achieve High-Quality Fermented Sausages.

PubMed

Nediani, Miriam T; García, Luis; Saavedra, Lucila; Martínez, Sandra; López Alzogaray, Soledad; Fadda, Silvina

2017-05-17

Quality and safety are important challenges in traditional fermented sausage technology. Consequently, the development of a tailored starter culture based on indigenous microbiota constitutes an interesting alternative. In the present study, spontaneously fermented goat meat sausages were created and analyzed using a physicochemical and microbiological approach. Thereafter 170 lactic acid bacteria (LAB) strains were isolated and preliminary characterized by phenotypic assays. The hygienic and technological properties, and growth and fermentative potential of isolates using a goat-meat-based culture medium were evaluated. All strains proved to have bioprotective features due to their acidogenic metabolism. Almost all grew optimally in meat environments. LAB isolates presented proteolytic activity against meat proteins and enriched amino acid contents of the goat-meat-based model. The most efficient strains were four different Lactobacillus sakei isolates, as identified by genotyping and RAPD analysis. L. sakei strains are proposed as optimal candidates to improve the production of fermented goat meat sausages, creating a new added-value fermented product.

Binding and detoxification of chlorpyrifos by lactic acid bacteria on rice straw silage fermentation.

PubMed

Wang, Yan-Su; Wu, Tian-Hao; Yang, Yao; Zhu, Cen-Ling; Ding, Cheng-Long; Dai, Chuan-Chao

2016-01-01

This investigation examined the reduction of pesticide residues on straw inoculated with lactic acid bacteria (LAB) during ensiling. Lactobacillus casei WYS3 was isolated from rice straw that contained pesticide residues. Non-sterilized rice straw, which was inoculated with L. casei WYS3, showed increased removal of chlorpyrifos after ensiling, compared with rice straw that was not inoculated with L. casei WYS3 or sterilized rice straw. In pure culture, these strains can bind chlorpyrifos as indicated by high-performance liquid chromatography analysis. Viable L. casei WYS3 was shown to bind 33.3-42% of exogenously added chlorpyrifos. These results are similar to those of acid-treated cells but less than those of heat-treated cells, which were found to bind 32.0% and 77.2% of the added chlorpyrifos respectively. Furthermore, gas chromatography-mass spectrometry analysis determined that L. casei WYS3 detoxified chlorpyrifos via P-O-C cleavage. Real-time polymerized chain reaction analysis determined that organophosphorus hydrolase gene expression tripled after the addition of chlorpyrifos to LAB cultures, compared with the control group (without chlorpyrifos). This paper highlights the potential use of LAB starter cultures for the detoxification and removal of chlorpyrifos residues in the environment.

Impact of yeast starter formulations on the production of volatile compounds during wine fermentation.

PubMed

Romano, Patrizia; Pietrafesa, Rocchina; Romaniello, Rossana; Zambuto, Marianna; Calabretti, Antonella; Capece, Angela

2015-01-01

The most diffused starter formulation in winemaking is actually represented by active dry yeast (ADY). Spray-drying has been reported as an appropriate preservation method for yeast and other micro-organisms. Despite the numerous advantages of this method, the high air temperatures used can negatively affect cell viability and the fermentative performance of dried cells. In the present study, 11 wine S. cerevisiae strains (both indigenous and commercial) were submitted to spray-drying; different process conditions were tested in order to select the conditions allowing the highest strain survival. The strains exhibited high variability for tolerance to spray-drying treatment. Selected strains were tested in fermentation at laboratory scale in different formulations (free fresh cells, free dried cells, immobilized fresh cells and immobilized dried cells), in order to assess the influence of starter formulation on fermentative fitness of strains and aromatic quality of wine. The analysis of volatile fraction in the experimental wines produced by selected strains in different formulations allowed identification of > 50 aromatic compounds (alcohols, esters, ketones, aldehydes and terpenes). The results obtained showed that the starter formulation significantly influenced the content of volatile compounds. In particular, the wines obtained by strains in dried forms (as both free and immobilized cells) contained higher numbers of volatile compounds than wines obtained from fresh cells. Copyright © 2014 John Wiley & Sons, Ltd.

Physico-chemical characterization of natural fermentation process of Conservolea and Kalamàta table olives and developement of a protocol for the pre-selection of fermentation starters.

PubMed

Bleve, Gianluca; Tufariello, Maria; Durante, Miriana; Grieco, Francesco; Ramires, Francesca Anna; Mita, Giovanni; Tasioula-Margari, Maria; Logrieco, Antonio Francesco

2015-04-01

Table olives are one of the most important traditional fermented vegetables in Europe and their world consumption is constantly increasing. Conservolea and Kalamàta are the most important table olives Greek varieties. In the Greek system, the final product is obtained by spontaneous fermentations, without any chemical debittering treatment. This natural fermentation process is not predictable and strongly influenced by the physical-chemical conditions and by the presence of microorganisms contaminating the olives. Natural fermentations of Conservolea and Kalamàta cultivars black olives were studied in order to determine microbiological, biochemical and chemical evolution during the process. Following the process conditions generally used by producers, in both cultivars, yeasts were detected throughout the fermentation, whereas lactic acid bacteria (LAB) appeared in the last staged of the process. A new optimized specific protocol was developed to select autochthonous yeast and LAB isolates that can be good candidates as starters. These microorganisms were pre-selected for their ability to adapt to model brines, to have beta-glucosidase activity, not to produce biogenic amines. Chemical compounds deriving by microbiological activities and associated to the three different phases (30, 90 and 180 days) of the fermentation process were identified and were proposed as chemical descriptors to follow the fermentation progress. Copyright © 2014 Elsevier Ltd. All rights reserved.

Microbiological study of lactic acid bacteria in kefir grains by culture-dependent and culture-independent methods.

PubMed

Chen, Hsi-Chia; Wang, Sheng-Yao; Chen, Ming-Ju

2008-05-01

Lactic acid bacteria (LAB) in different original kefir grains were first assessed using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) by a culture-dependent way, and were further confirmed by DNA sequencing techniques. Results indicated that a combined method of cultivation with PCR-DGGE and subsequent DNA sequencing could successfully identify four LAB strains from three kefir grains from Taiwan (named Hsinchu, Mongolia and Ilan). Lactobacillus kefiri accounted, in the three kefir grains, for at least half of the isolated colonies while Lb. kefiranofaciens was the second most frequently isolated species. Leuconostoc mesenteroides was less frequently found but still in the three kefir grains conversely to Lactococcus lactis which based on culture-dependent isolation was only found in two of the kefir grains. It was interesting to find that all three kefir grains contain similar LAB species. Furthermore, the DGGE as a culture-independent method was also applied to detect the LAB strains. Results indicated that Lb. kefiranofaciens was found in all three kefir grains, whereas Lb. kefiri was only observed in Hsinchu kefir grain and Lc. lactis was found in both Mongolia and Ilan samples. Two additional strains, Pseudomonas spp. and E. coli, were also detected in kefir grains.

Identification and characterization of lactic acid bacteria and yeasts of PDO Tuscan bread sourdough by culture dependent and independent methods.

PubMed

Palla, Michela; Cristani, Caterina; Giovannetti, Manuela; Agnolucci, Monica

2017-06-05

Sourdough fermentation has been increasingly used worldwide, in accordance with the demand of consumers for tasty, natural and healthy food. The high diversity of lactic acid bacteria (LAB) and yeast species, detected in sourdoughs all over the world, may affect nutritional, organoleptic and technological traits of leavened baked goods. A wide regional variety of traditional sourdough breads, over 200 types, has been recorded in Italy, including special types selected as worthy of either Protected Geographical Indication (PGI) or Protected Designation of Origin (PDO), whose sourdough microbiota has been functionally and molecularly characterized. As, due to the very recent designation, the microbiota of Tuscan bread sourdough has not been investigated so far, the aim of the present work was to isolate and characterize the species composition of LAB and yeasts of PDO Tuscan bread sourdough by culture-independent and dependent methods. A total of 130 yeasts from WLN medium and 193 LAB from both mMRS and SDB media were isolated and maintained to constitute the germplasm bank of PDO Tuscan bread. Ninety six LAB from mMRS medium and 68 yeasts from WLN medium were randomly selected and molecularly identified by ARDRA (Amplified Ribosomal DNA Restriction Analysis) and PCR-RFLP analysis of the ITS region, respectively, and sequencing. The yeast identity was confirmed by 26S D1/D2 sequencing. All bacterial isolates showed 99% identity with Lactobacillus sanfranciscensis, 65 yeast isolates were identified as Candida milleri, and 3 as Saccharomyces cerevisiae. Molecular characterization of PDO Tuscan bread sourdough by PCR-DGGE confirmed such data. The distinctive tripartite species association, detected as the microbiota characterizing the sourdough used to produce PDO Tuscan bread, encompassed a large number of L. sanfranciscensis and C. milleri strains, along with a few of S. cerevisiae. The relative composition and specific physiological characteristics of such microbiota

Limited use of Centritech Lab II Centrifuge in perfusion culture of rCHO cells for the production of recombinant antibody.

PubMed

Kim, Byoung Jin; Oh, Duk Jae; Chang, Ho Nam

2008-01-01

Perfusion cultures of recombinant Chinese hamster ovary cells, producing recombinant antibody against the S surface antigen of Hepatitis B virus, were carried out in continuous and intermittent mode using a Centritech Lab II Centrifuge. In the continuous perfusion process, despite the absence of shear stress from the pump head, long-term operation was not possible because of continuously repeated exposure to oxygen limitation and low temperature, as well as shear stress from centrifugal force. In the intermittent perfusion processes, the frequency of cell-passage through the centrifuge was substantially reduced, compared with the continuous perfusion mode; however, the degree of reduction could not guarantee stable long-term operation. Although various operating parameters were applied in the intermittent perfusion cultures, high cell densities could not be maintained stably. In a single bioreactor culture system, a specific cell that is returned from the centrifuge to the bioreactor could be transferred from the bioreactor to the centrifuge again in the next cycle. These repetitive damages, caused by shear stress from the pump head and centrifugal force, as well as exposure to suboptimal conditions such as oxygen limitation and low temperature below 37 degrees C, were more serious at higher perfusion rates. Subsequently, damaged cells and dead cells were continuously accumulated in the bioreactor. Culture temperature shift from 37 to 33 degrees C increased antibody concentrations but showed inhibitory effects on cell growth. The negative effects of lowering culture temperature on cell growth overwhelmed the positive effects on antibody production. To protect cells from shear stress, Pluronic F-68 was 2-fold concentrated in the culture medium; nevertheless, a significantly higher concentration of Pluronic F-68 (2 g/L) may have inhibitory effects on cell growth.

Hyperconcentrated Sweet Whey, a New Culture Medium That Enhances Propionibacterium freudenreichii Stress Tolerance.

PubMed

Huang, Song; Rabah, Houem; Jardin, Julien; Briard-Bion, Valérie; Parayre, Sandrine; Maillard, Marie-Bernadette; Le Loir, Yves; Chen, Xiao Dong; Schuck, Pierre; Jeantet, Romain; Jan, Gwénaël

2016-08-01

Propionibacterium freudenreichii is used as a cheese-ripening starter and as a probiotic. Its reported physiological effects at the gut level, including modulation of bifidobacteria, colon epithelial cell proliferation and apoptosis, and intestinal inflammation, rely on active metabolism in situ Survival and activity are thus key factors determining its efficacy, creating stress adaptation and tolerance bottlenecks for probiotic applications. Growth media and growth conditions determine tolerance acquisition. We investigated the possibility of using sweet whey, a dairy by-product, to sustain P. freudenreichii growth. It was used at different concentrations (dry matter) as a culture medium. Using hyperconcentrated sweet whey led to enhanced multistress tolerance acquisition, overexpression of key stress proteins, and accumulation of intracellular storage molecules and compatible solutes, as well as enhanced survival upon spray drying. A simplified process from growth to spray drying of propionibacteria was developed using sweet whey as a 2-in-1 medium to both culture P. freudenreichii and protect it from heat and osmotic injury without harvesting and washing steps. As spray drying is far cheaper and more energy efficient than freeze-drying, this work opens new perspectives for the sustainable development of new starter and probiotic preparations with enhanced robustness. In this study, we demonstrate that sweet whey, a dairy industry by-product, not only allows the growth of probiotic dairy propionibacteria, but also triggers a multitolerance response through osmoadaptation and general stress response. We also show that propionibacteria accumulate compatible solutes under these culture conditions, which might account for the limited loss of viability after spray drying. This work opens new perspectives for more energy-efficient production of dairy starters and probiotics. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Growth performance of calves fed microbially enhanced soy protein in pelleted starters.

PubMed

Senevirathne, N D; Anderson, J L; Gibbons, W R; Clapper, J A

2017-01-01

Our objective was to determine effects of feeding calves pelleted starters with microbially enhanced (fungi-treated) soy protein (MSP) in replacement of soybean meal (SBM) with different milk replacers (MR). Thirty-six Holstein calves (2 d old; 24 females, 12 males) in individual hutches were used in a 12-wk randomized complete block design study. Treatments were (1) MSP pellets with MR formulated for accelerated growth (28% crude protein, 18% fat; MSPA), (2) SBM pellets with MR formulated for accelerated growth (SBMA), and (3) MSP pellets with conventional MR (20% crude protein, 20% fat; MSPC). Pellets were similar except for 23% MSP or 23% SBM (dry matter basis). Pellets and water were fed ad libitum throughout the study. Feeding rates of MR on a dry matter basis were 0.37kg twice daily during wk 1, 0.45kg twice daily during wk 2 to 5, and 0.45kg once daily during wk 6. Intakes were recorded daily. Body weights, frame size measurements, and jugular blood samples were collected 2 d every 2 wk at 3 h after the morning feeding. Fecal grab samples were collected 5 times per d for 3 d during wk 12 and then composited by calf for analysis of apparent total-tract digestibility of nutrients using acid detergent insoluble ash as an internal marker. Total and starter pellet dry matter intake were greatest for calves fed SBMA and least for MSPC. Calves had similar average daily gain among treatments, but there was a treatment by week interaction and during the last few weeks of the study calves on MSPC had less body weight compared with MSPA or SBMA. Gain-to-feed ratio was similar among treatments; however, there was a treatment by week interaction. Serum glucose was similar among treatments. Plasma urea nitrogen was greatest for calves fed MSPA and least for MSPC. Plasma concentrations of IGF-1 were greatest for calves fed SBMA. Plasma concentrations of triglycerides were greatest for calves fed MSPC. Plasma concentrations of β-hydroxybutyrate had a treatment by time

Influence of winding construction on starter-generator thermal processes

NASA Astrophysics Data System (ADS)

Grachev, P. Yu; Bazarov, A. A.; Tabachinskiy, A. S.

2018-01-01

Dynamic processes in starter-generators features high winding are overcurrent. It can lead to insulation overheating and fault operation mode. For hybrid and electric vehicles, new high efficiency construction of induction machines windings is proposed. Stator thermal processes need be considered in the most difficult operation modes. The article describes construction features of new compact stator windings, electromagnetic and thermal models of processes in stator windings and explains the influence of innovative construction on thermal processes. Models are based on finite element method.

A Comparative Study on Real Lab and Simulation Lab in Communication Engineering from Students' Perspectives

ERIC Educational Resources Information Center

Balakrishnan, B.; Woods, P. C.

2013-01-01

Over the years, rapid development in computer technology has engendered simulation-based laboratory (lab) in addition to the traditional hands-on (physical) lab. Many higher education institutions adopt simulation lab, replacing some existing physical lab experiments. The creation of new systems for conducting engineering lab activities has raised…

Kinematic Labs with Mobile Devices

NASA Astrophysics Data System (ADS)

Kinser, Jason M.

2015-07-01

This book provides 13 labs spanning the common topics in the first semester of university-level physics. Each lab is designed to use only the student's smartphone, laptop and items easily found in big-box stores or a hobby shop. Each lab contains theory, set-up instructions and basic analysis techniques. All of these labs can be performed outside of the traditional university lab setting and initial costs averaging less than 8 per student, per lab.

MethLAB

PubMed Central

Kilaru, Varun; Barfield, Richard T; Schroeder, James W; Smith, Alicia K

2012-01-01

Recent evidence suggests that DNA methylation changes may underlie numerous complex traits and diseases. The advent of commercial, array-based methods to interrogate DNA methylation has led to a profusion of epigenetic studies in the literature. Array-based methods, such as the popular Illumina GoldenGate and Infinium platforms, estimate the proportion of DNA methylated at single-base resolution for thousands of CpG sites across the genome. These arrays generate enormous amounts of data, but few software resources exist for efficient and flexible analysis of these data. We developed a software package called MethLAB (http://genetics.emory.edu/conneely/MethLAB) using R, an open source statistical language that can be edited to suit the needs of the user. MethLAB features a graphical user interface (GUI) with a menu-driven format designed to efficiently read in and manipulate array-based methylation data in a user-friendly manner. MethLAB tests for association between methylation and relevant phenotypes by fitting a separate linear model for each CpG site. These models can incorporate both continuous and categorical phenotypes and covariates, as well as fixed or random batch or chip effects. MethLAB accounts for multiple testing by controlling the false discovery rate (FDR) at a user-specified level. Standard output includes a spreadsheet-ready text file and an array of publication-quality figures. Considering the growing interest in and availability of DNA methylation data, there is a great need for user-friendly open source analytical tools. With MethLAB, we present a timely resource that will allow users with no programming experience to implement flexible and powerful analyses of DNA methylation data. PMID:22430798

Use of a Remote Car Starter in Relation to Smog and Climate Change Perceptions: A Population Survey in Québec (Canada)

PubMed Central

Bélanger, Diane; Gosselin, Pierre; Valois, Pierre; Germain, Stéphane; Abdous, Belkacem

2009-01-01

Remote car starters encourage motorists to warm up their vehicles by idling the motor – thus increasing atmospheric pollutants, including several greenhouse gas (GHG) with impacts on public health. This study about climate change (CC) adaptation and mitigation actions examined perceptions on air pollution and climate change and individual characteristics associated with the use of a remote car starter. A telephone survey (n = 2,570; response rate: 70%) of adults living in Québec (Canada) measured the respondents’ beliefs and current behaviours regarding CC. Approximately 32.9% (daily car users) and 27.4% (occasional users) reported using a remote car starter during winter. The odds of the use of a remote car starter was higher in the less densely populated central (OR: 1.5) and peripheral regions (OR: 2.7) compared to the urban centers (ex. Montreal). The odds was also higher in population with a mother tongue other than English or French (OR: 2.6) and francophones than anglophones (OR: 2.1), women than men (OR: 1.5), daily drivers than occasional ones (OR: 1.2), and respondents who at least sometimes consulted temperature/humidity reports than those who consulted them less often (OR: 1.5). In multivariate analysis, the perception of living in a region susceptible to winter smog, being aware of smog warnings, or the belief in the human contribution to CC did not significantly influence the use of a remote car starter. The use of remote car starters encourages idling which produces increased atmospheric pollution and GHG production and it should be more efficiently and vigorously managed by various activities. A five-minute daily reduction in idling is equivalent to reducing the total car emissions by 1.8%. This would constitute a “no-regrets” approach to CC as it can simultaneously reduce GHG, air pollution and their health impacts. PMID:19440410

Use of a remote car starter in relation to smog and climate change perceptions: a population survey in Québec (Canada).

PubMed

Bélanger, Diane; Gosselin, Pierre; Valois, Pierre; Germain, Stéphane; Abdous, Belkacem

2009-02-01

Remote car starters encourage motorists to warm up their vehicles by idling the motor--thus increasing atmospheric pollutants, including several greenhouse gas (GHG) with impacts on public health. This study about climate change (CC) adaptation and mitigation actions examined perceptions on air pollution and climate change and individual characteristics associated with the use of a remote car starter. A telephone survey (n = 2,570; response rate: 70%) of adults living in Québec (Canada) measured the respondents' beliefs and current behaviours regarding CC. Approximately 32.9% (daily car users) and 27.4% (occasional users) reported using a remote car starter during winter. The odds of the use of a remote car starter was higher in the less densely populated central (OR: 1.5) and peripheral regions (OR: 2.7) compared to the urban centers (ex. Montreal). The odds was also higher in population with a mother tongue other than English or French (OR: 2.6) and francophones than anglophones (OR: 2.1), women than men (OR: 1.5), daily drivers than occasional ones (OR: 1.2), and respondents who at least sometimes consulted temperature/humidity reports than those who consulted them less often (OR: 1.5). In multivariate analysis, the perception of living in a region susceptible to winter smog, being aware of smog warnings, or the belief in the human contribution to CC did not significantly influence the use of a remote car starter. The use of remote car starters encourages idling which produces increased atmospheric pollution and GHG production and it should be more efficiently and vigorously managed by various activities. A five-minute daily reduction in idling is equivalent to reducing the total car emissions by 1.8%. This would constitute a "no-regrets" approach to CC as it can simultaneously reduce GHG, air pollution and their health impacts.

Teachers' Perspectives on Online Virtual Labs vs. Hands-On Labs in High School Science

NASA Astrophysics Data System (ADS)

Bohr, Teresa M.

This study of online science teachers' opinions addressed the use of virtual labs in online courses. A growing number of schools use virtual labs that must meet mandated laboratory standards to ensure they provide learning experiences comparable to hands-on labs, which are an integral part of science curricula. The purpose of this qualitative case study was to examine teachers' perceptions of the quality and effectiveness of high school virtual labs. The theoretical foundation was constructivism, as labs provide student-centered activities for problem solving, inquiry, and exploration of phenomena. The research questions focused on experienced teachers' perceptions of the quality of virtual vs. hands-on labs. Data were collected through survey questions derived from the lab objectives of The Next Generation Science Standards . Eighteen teachers rated the degree of importance of each objective and also rated how they felt virtual labs met these objectives; these ratings were reported using descriptive statistics. Responses to open-ended questions were few and served to illustrate the numerical results. Many teachers stated that virtual labs are valuable supplements but could not completely replace hands-on experiences. Studies on the quality and effectiveness of high school virtual labs are limited despite widespread use. Comprehensive studies will ensure that online students have equal access to quality labs. School districts need to define lab requirements, and colleges need to specify the lab experience they require. This study has potential to inspire positive social change by assisting science educators, including those in the local school district, in evaluating and selecting courseware designed to promote higher order thinking skills, real-world problem solving, and development of strong inquiry skills, thereby improving science instruction for all high school students.

Microbiological and chemical characteristics of tarubá, an indigenous beverage produced from solid cassava fermentation.

PubMed

Ramos, Cíntia L; de Sousa, Edinaira S O; Ribeiro, Jessimara; Almeida, Tayanny M M; Santos, Claudia Cristina A do A; Abegg, Maxwel A; Schwan, Rosane F

2015-08-01

The aim of this work was to identify and characterize the microbiota present during fermentation and in the final beverage, tarubá, by culture-dependent and -independent methods. In addition, target chemical compounds (carbohydrates, organic acids, and ethanol) were evaluated. Lactic acid bacteria (LAB) and mesophilic bacteria were the predominant microorganisms. Among them, Lactobacillus plantarum, Lactobacillus brevis, Leuconostoc mesenteroides, and Bacillus subtilis were frequently isolated and detected by DGGE analysis. Torulaspora delbrueckii was the dominant yeast species. Yeast isolates Pichia exigua, Candida rugosa, T. delbrueckii, Candida tropicalis, Pichia kudriavzevii, Wickerhamomyces anomalus, and Candida ethanolica and bacteria isolates Lb. plantarum, Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus licheniformis, Bacillus sp., and Chitinophaga terrae showed amylolytic activity. Only isolates of P. exigua and T. delbrueckii and all species of the genus Bacillus identified in this work exhibited proteolytic activity. All microbial isolates grew at 38 °C, and only the isolates belonging to Hanseniaspora uvarum species did not grow at 42 °C. These characteristics are important for further development of starter cultures; isolates of T. delbrueckii, P. exigua, and Bacillus species identified in this work displayed all of these properties and are potential strains for use as starter culture in cassava fermented food. Copyright © 2015 Elsevier Ltd. All rights reserved.

A comparative study on real lab and simulation lab in communication engineering from students' perspectives

NASA Astrophysics Data System (ADS)

Balakrishnan, B.; Woods, P. C.

2013-05-01

Over the years, rapid development in computer technology has engendered simulation-based laboratory (lab) in addition to the traditional hands-on (physical) lab. Many higher education institutions adopt simulation lab, replacing some existing physical lab experiments. The creation of new systems for conducting engineering lab activities has raised concerns among educators on the merits and shortcomings of both physical and simulation labs; at the same time, many arguments have been raised on the differences of both labs. Investigating the effectiveness of both labs is complicated, as there are multiple factors that should be considered. In view of this challenge, a study on students' perspectives on their experience related to key aspects on engineering laboratory exercise was conducted. In this study, the Visual Auditory Read and Kinetic model was utilised to measure the students' cognitive styles. The investigation was done through a survey among participants from Multimedia University, Malaysia. The findings revealed that there are significant differences for most of the aspects in physical and simulation labs.

A Constructivist Cloud Lab.

ERIC Educational Resources Information Center

Emery, Dave

1996-01-01

Describes a lab involving a cloud formation activity that uses the constructivist learning model to get students more involved in creating the lab. Enables students to develop a greater understanding of the concepts involved and more interest in the lab's outcomes. (JRH)

Virtual Reality Lab Assistant

NASA Technical Reports Server (NTRS)

Saha, Hrishikesh; Palmer, Timothy A.

1996-01-01

Virtual Reality Lab Assistant (VRLA) demonstration model is aligned for engineering and material science experiments to be performed by undergraduate and graduate students in the course as a pre-lab simulation experience. This will help students to get a preview of how to use the lab equipment and run experiments without using the lab hardware/software equipment. The quality of the time available for laboratory experiments can be significantly improved through the use of virtual reality technology.

Effects of different physical forms of wheat grain in corn-based starter on performance of young Holstein dairy calves.

PubMed

Pezhveh, N; Ghorbani, G R; Rezamand, P; Khorvash, M

2014-10-01

The objective of the present study was to examine the effects of partially replacing corn with 2 forms of wheat grain on daily intake of starter feed, average daily gain, feed efficiency, rumen pH, fecal score, weaning weight, skeletal growth, and blood metabolites of dairy calves. Thirty-two male and female Holstein dairy calves (n=8 calves per treatment) were used in a completely randomized block design. At d 3 of age, individually housed calves were randomly allocated to different treatments consisting of a starter diet with 60% ground corn (control), a starter diet with 60% whole corn, a starter diet with 30% ground corn plus 30% ground wheat (GCGW), and a starter with 30% ground corn plus 30% whole wheat (GCWW), with all other components in a meal form. All calves had free access to water and feed throughout the study period and received 4 L of milk replacer/d from d 3 to 50 and 2 L/d from d 50 to 52; weaning occurred at the end of d 52. Feed intake was recorded daily and body weight and skeletal growth measures were recorded on d 10 and every 10 d thereafter. Rumen pH was measured on d 30, 45, and 60. Blood sample were collected on d 30 and every 10 d thereafter through d 70. Data were analyzed using MIXED procedures of SAS (SAS Institute Inc., Cary, NC). Over the experimental period (d 1-70), the starter intake for the GCWW group was significantly different from the control group, but not different from the other groups. Calves fed whole wheat had a significantly greater average daily gain compared with other groups over the experimental period (d 1-70). Feed efficiency was only better in calves fed the GCWW diet than the GCGW group for postweaning and overall periods. No differences were observed for preweaning in body length, hip height, or withers height among the treatments; however, differences were significant in heart girth and body barrel. Postweaning, some of the body measurements were greater in calves fed the GCWW and GCGW starter diets. Blood

LabSkills

ERIC Educational Resources Information Center

O'Brien, Nick

2010-01-01

This article describes LabSkills, a revolutionary teaching tool to improve practical science in schools. LabSkills offers the chance to help improve the exposure that the average Key Stage 5 (age 16-19) student has to practical work. This is a huge area for development being highlighted by universities who are seeing a worryingly growing trend in…

Methionine catabolism and production of volatile sulphur compounds by OEnococcus oeni.

PubMed

Pripis-Nicolau, L; de Revel, G; Bertrand, A; Lonvaud-Funel, A

2004-01-01

During malolactic fermentation (MLF), the secondary metabolisms of lactic acid bacteria (LAB) contribute to the organoleptic modification of wine. To understand the contribution of MLF, we evaluated the capacity of various wine LAB to metabolize methionine. Using gas chromatography (GC) coupled either with mass spectrometry (MS) or a flame photometry detector in sulphur mode (FPD), we studied this metabolism in laboratory media and wine. In laboratory media, several LAB isolated from wine were able to metabolize methionine. They formed methanethiol, dimethyl disulphide, 3-(methylsulphanyl)propan-1-ol and 3-(methylsulphanyl)propionic acid. These are known to have powerful characteristic odours and play a role in the aromatic complexity of wine. In various red wines, after MLF only the 3-(methylsulphanyl)propionic acid concentration increased significantly, as verified with several commercial starter cultures. This compound, which is characterized by chocolate and roasted odours, could contribute to the aromatic complexity produced by MLF. This study shows that LAB isolated from wine, especially OEnococcus oeni strains, the major species in MLF, are able to metabolize methionine to form volatile sulphur compounds. This is the first study to demonstrate the capacity of wine LAB to metabolize methionine.

Taxonomic structure and monitoring of the dominant population of lactic acid bacteria during wheat flour sourdough type I propagation using Lactobacillus sanfranciscensis starters.

PubMed

Siragusa, Sonya; Di Cagno, Raffaella; Ercolini, Danilo; Minervini, Fabio; Gobbetti, Marco; De Angelis, Maria

2009-02-01

The structure and stability of the dominant lactic acid bacterium population were assessed during wheat flour sourdough type I propagation by using singly nine strains of Lactobacillus sanfranciscensis. Under back-slopping propagation with wheat flour type 0 F114, cell numbers of presumptive lactic acid bacteria varied slightly between and within starters. As determined by randomly amplified polymorphic DNA-PCR and restriction endonuclease analysis-pulsed-field gel electrophoresis analyses, only three (LS8, LS14, and LS44) starters dominated throughout 10 days of propagation. The others progressively decreased to less than 3 log CFU g(-1). Partial sequence analysis of the 16S rRNA and recA genes and PCR-denaturating gradient gel electrophoresis analysis using the rpoB gene allowed identification of Weissella confusa, Lactobacillus sanfranciscensis, Lactobacillus plantarum, Lactobacillus rossiae, Lactobacillus brevis, Lactococcus lactis subsp. lactis, Pediococcus pentosaceus, and Lactobacillus spp. as the dominant species of the raw wheat flour. At the end of propagation, one autochthonous strain of L. sanfranciscensis was found in all the sourdoughs. Except for L. brevis, strains of the above species were variously found in the mature sourdoughs. Persistent starters were found in association with other biotypes of L. sanfranciscensis and with W. confusa or L. plantarum. Sourdoughs were characterized for acidification, quotient of fermentation, free amino acids, and community-level catabolic profiles by USING Biolog 96-well Eco microplates. In particular, catabolic profiles of sourdoughs containing persistent starters behaved similarly and were clearly differentiated from the others. The three persistent starters were further used for the production of sourdoughs and propagated by using another wheat flour whose lactic acid bacterium population in part differed from the previous one. Also, in this case all three starter strains persisted during propagation.

Performance of starter in yogurt supplemented with soy protein isolate and biotransformation of isoflavones during storage period.

PubMed

Pham, T Thuy; Shah, Nagendra P

2009-01-01

In this study, soy protein isolate (SPI) (4%, v/w) was supplemented to the yogurt mix to increase the amount of biologically active isoflavone in yogurt (SY). The control yogurt was without any SPI supplementation (USY). The supplementation significantly (P < 0.05) increased the lactose metabolism by the yogurt starter including Lactobacillus delbrueckii ssp. bulgaricus ATCC 11842 (Lb 11842) and Streptococcus thermophilus ST 1342 (ST 1342) during the fermentation process by 4.7%. The starter produced more acetic acid and less lactic acid in SY than that in USY and altered the ratio of lactic and acetic acid during the entire storage period. The viability of both Lb 11842 and ST 1342 in SY was significantly (P < 0.05) lower than that in USY from 14 d of the storage period, however, their concentration still remained high (8.11 to 8.84 log CFU/g). The starter transformed 72.8% of total inactive isoflavone glycosides (IG) to active isoflavone aglycones (IA), increasing the IA content from 1.35 to 15.01 mg/100 g sample. During the storage period, IA concentration slowly rose from 15.02 to 15.51 mg/100 g sample.

CRISPR analysis of bacteriophage-insensitive mutants (BIMs) of industrial Streptococcus thermophilus--implications for starter design.

PubMed

Mills, S; Griffin, C; Coffey, A; Meijer, W C; Hafkamp, B; Ross, R P

2010-03-01

An efficient approach for generation of bacteriophage-insensitive mutants (BIMs) of Streptococcus thermophilus starters was described in our laboratory [Mills et al. (2007) J Microbiol Methods70, 159-164]. The aim of this study was to analyse the phage resistance mechanism responsible for BIM formation. Three clustered regularly interspaced short palindromic repeat (CRISPR) regions have been identified in Strep. thermophilus, and Strep. thermophilus can integrate novel spacers into these loci in response to phage attack. Characterization of three sets of BIMs indicated that two sets had altered CRISPR1 and/or CRISPR3 loci. A range of BIMs of yoghurt starter CSK938 were generated with the same phage in different phage challenge experiments, and each acquired unique spacer regions ranging between one and four new spacers in CRISPR1. In addition, the BIM that acquired only one new spacer in CRISPR1 also acquired an additional spacer in CRISPR3. A fourth BIM, generated with a different phage, had two spacers deleted from CRISPR1 but acquired two spacers in CRISPR3. Analysis of the Mozzarella starter CSK939 and its associated BIMs indicated that formation of second generation BIMs does not lead to increases in spacer number but to alterations in spacer regions. BIMs of an exopolysaccharide (EPS)-producing strain that lost the ability to produce EPS did not harbour an altered CRISPR, suggesting that phage sensitivity may be related to the EPS-producing phenotype. Acquisition/deletion of new spacers in CRISPR loci in response to phage attack generates distinctly individual variants. It also demonstrates that other modifications may be responsible for the phage resistance of Strep. thermophilus BIMs. Isolation of individual BIMs that have unique spacers towards the leader region of the CRISPR locus may be a very useful approach for rotation strategies with the same starter backbone. Upon phage infection, BIMs 'in reserve' can be slotted into the rotation scheme.

Improving the Achievement on Writing Narrative Text through Discussion Starter Story Technique

ERIC Educational Resources Information Center

Purba, Rodearta

2018-01-01

The objective of this study is to find out whether discussion starter story significantly improves the achievement on narrative text of the first grade students of Senior High School. This study was conducted by applying Classroom Action Research (CAR). The subject of this study is the first grade students of SMA Negeri 2 Pangururan in academic…

Story Starters on the Aztecs, Incas, and Mayas. A Creative Writing Program.

ERIC Educational Resources Information Center

Henrich, Steve; Henrich, Jean

Designed to supplement an established language arts and social studies program, this books deals with the Aztecs, Incas, and Mayas of Latin America. All of the "Story Starter" books are intended to give a variety of vocabulary and story ideas to help with the writing process. Each of the books is divided into four main sections: (1) an…

Exploring the Microbiota of Faba Bean: Functional Characterization of Lactic Acid Bacteria.

PubMed

Verni, Michela; Wang, Changyin; Montemurro, Marco; De Angelis, Maria; Katina, Kati; Rizzello, Carlo G; Coda, Rossana

2017-01-01

This study investigated the metabolic traits of 27 lactic acid bacteria (LAB) strains belonging to different species, previously isolated from faba bean. The activities assayed, related to technological and nutritional improvement of fermented faba bean, included peptidases, β-glucosidase, phytase, as well as exopolysaccharides synthesis and antimicrobial properties. In addition, the bacteria performance as starter cultures during faba bean fermentation on proteolysis, antioxidant potential, and degradation of condensed tannins were assessed. Fermentative profiling showed that only 7 out of 27 strains were able to metabolize D-raffinose, particularly Leuc. mesenteroides I01 and I57. All strains of Pediococcus pentosaceus exerted high PepN activity and exhibited β-glucosidase activity higher than the median value of 0.015 U, while phytase activity was largely distributed among the different strains. All the weissellas, and in lower amount leuconostocs, showed ability to produce EPS from sucrose. None of the strains did not survive the simulated gastrointestinal tract with the exception of P. pentosaceus I56, I76, 147, I214, having a viability of 8-9 log CFU/ml at the end of the treatment. None of the strains showed antimicrobial activity toward Staphylococcus aureus , while eight strains of P. pentosaceus exhibited a strong inhibitory activity toward Escherichia coli and Listeria monocytogenes . Generally, the doughs fermented with pediococci exhibited high amount of total free amino acids, antioxidant activity, and condensed tannins degradation. These results allowed the identification of LAB biotypes as potential starter cultures for faba bean bioprocessing, aiming at the enhancement of faba bean use in novel food applications.

Exploring the Microbiota of Faba Bean: Functional Characterization of Lactic Acid Bacteria

PubMed Central

Verni, Michela; Wang, Changyin; Montemurro, Marco; De Angelis, Maria; Katina, Kati; Rizzello, Carlo G.; Coda, Rossana

2017-01-01

This study investigated the metabolic traits of 27 lactic acid bacteria (LAB) strains belonging to different species, previously isolated from faba bean. The activities assayed, related to technological and nutritional improvement of fermented faba bean, included peptidases, β-glucosidase, phytase, as well as exopolysaccharides synthesis and antimicrobial properties. In addition, the bacteria performance as starter cultures during faba bean fermentation on proteolysis, antioxidant potential, and degradation of condensed tannins were assessed. Fermentative profiling showed that only 7 out of 27 strains were able to metabolize D-raffinose, particularly Leuc. mesenteroides I01 and I57. All strains of Pediococcus pentosaceus exerted high PepN activity and exhibited β-glucosidase activity higher than the median value of 0.015 U, while phytase activity was largely distributed among the different strains. All the weissellas, and in lower amount leuconostocs, showed ability to produce EPS from sucrose. None of the strains did not survive the simulated gastrointestinal tract with the exception of P. pentosaceus I56, I76, 147, I214, having a viability of 8–9 log CFU/ml at the end of the treatment. None of the strains showed antimicrobial activity toward Staphylococcus aureus, while eight strains of P. pentosaceus exhibited a strong inhibitory activity toward Escherichia coli and Listeria monocytogenes. Generally, the doughs fermented with pediococci exhibited high amount of total free amino acids, antioxidant activity, and condensed tannins degradation. These results allowed the identification of LAB biotypes as potential starter cultures for faba bean bioprocessing, aiming at the enhancement of faba bean use in novel food applications. PMID:29312174

A review on traditional Turkish fermented non-alcoholic beverages: microbiota, fermentation process and quality characteristics.

PubMed

Altay, Filiz; Karbancıoglu-Güler, Funda; Daskaya-Dikmen, Ceren; Heperkan, Dilek

2013-10-01

Shalgam juice, hardaliye, boza, ayran (yoghurt drink) and kefir are the most known traditional Turkish fermented non-alcoholic beverages. The first three are obtained from vegetables, fruits and cereals, and the last two ones are made of milk. Shalgam juice, hardaliye and ayran are produced by lactic acid fermentation. Their microbiota is mainly composed of lactic acid bacteria (LAB). Lactobacillus plantarum, Lactobacillus brevis and Lactobacillus paracasei subsp. paracasei in shalgam fermentation and L. paracasei subsp. paracasei and Lactobacillus casei subsp. pseudoplantarum in hardaliye fermentation are predominant. Ayran is traditionally prepared by mixing yoghurt with water and salt. Yoghurt starter cultures are used in industrial ayran production. On the other hand, both alcohol and lactic acid fermentation occur in boza and kefir. Boza is prepared by using a mixture of maize, wheat and rice or their flours and water. Generally previously produced boza or sourdough/yoghurt are used as starter culture which is rich in Lactobacillus spp. and yeasts. Kefir is prepared by inoculation of raw milk with kefir grains which consists of different species of yeasts, LAB, acetic acid bacteria in a protein and polysaccharide matrix. The microbiota of boza and kefir is affected from raw materials, the origin and the production methods. In this review, physicochemical properties, manufacturing technologies, microbiota and shelf life and spoilage of traditional fermented beverages were summarized along with how fermentation conditions could affect rheological properties of end product which are important during processing and storage. Copyright © 2013. Published by Elsevier B.V.

Lactic acid bacteria in Hamei and Marcha of North East India.

PubMed

Tamang, J P; Dewan, S; Tamang, B; Rai, A; Schillinger, U; Holzapfel, W H

2007-06-01

Hamei and Marcha are mixed dough inocula used as starters for preparation of various indigenous alcoholic beverages in Manipur and Sikkim in India, respectively. These starters are traditionally prepared from rice with wild herbs and spices. Samples of Hamei and Marcha, collected from Manipur and Sikkim, respectively, were analysed for lactic acid bacterial composition. The population of lactic acid bacteria (LAB) was 6.9 and 7.1 Log cfu/g in Hamei and Marcha, respectively. On the basis of phenotypic and genotypic characters, LAB strains isolated from Hamei and Marcha were identified as Pediococcus pentosaceus, Lactobacillus plantarum and Lactobacillus brevis. Technological properties of LAB such as antimicrobial properties, effect on acidification, ability to produce biogenic amines and ethanol, degree of hydrophobicity and enzymatic activities were also performed. Pediococcus pentosaceus HS: B1, isolated from Hamei, was found to produce bacteriocin. None of the strains produced biogenic amines. LAB strains showed a strong acidifying ability and they also produced a wide spectrum of enzymes.

Combined moist airtight storage and feed fermentation of barley by the yeast Wickerhamomyces anomalus and a lactic acid bacteria consortium

PubMed Central

Borling Welin, Jenny; Lyberg, Karin; Passoth, Volkmar; Olstorpe, Matilda

2015-01-01

This study combined moist airtight storage of moist grain with pig feed fermentation. Starter cultures with the potential to facilitate both technologies were added to airtight stored moist crimped cereal grain, and the impact on storage microflora and the quality of feed fermentations generated from the grain was investigated. Four treatments were compared: three based on moist barley, either un-inoculated (M), inoculated with Wickerhamomyces anomalus (W), or inoculated with W. anomalus and LAB starter culture, containing Pediococcus acidilactici DSM 16243, Pediococcus pentosaceus DSM 12834 and Lactobacillus plantarum DSM 12837 (WLAB); and one treatment based on dried barley (D). After 6 weeks of storage, four feed fermentations FM, FW, FWLAB, and FD, were initiated from M, W, WLAB, and D, respectively, by mixing the grain with water to a dry matter content of 30%. Each treatment was fermented in batch initially for 7 days and then kept in a continuous mode by adding new feed daily with 50% back-slop. During the 6 week storage period, the average water activity decreased in M, W and WLAB from 0.96 to 0.85, and cereal pH decreased from approximately 6.0 at harvest to 4.5. Feed fermentation conferred a further pH decrease to 3.8–4.1. In M, W and WLAB, molds and Enterobacteriaceae were mostly below detection limit, whereas both organism groups were detected in D. In fermented feed, Enterobacteriaceae were below detection limit in almost all conditions. Molds were detected in FD, for most of the fermentation time in FM and at some sampling points in FW and FWLAB. Starter organisms, especially W. anomalus and L. plantarum comprised a considerable proportion of the yeast and LAB populations, respectively, in both stored grain and fermented feed. However, autochthonous Pichia kudriavzevii and Kazachstania exigua partially dominated the yeast populations in stored grain and fermented feed, respectively. PMID:25954295

Microbiota Dynamics Associated with Environmental Conditions and Potential Roles of Cellulolytic Communities in Traditional Chinese Cereal Starter Solid-State Fermentation

PubMed Central

Li, Pan; Liang, Hebin; Lin, Wei-Tie; Feng, Feng

2015-01-01

Traditional Chinese solid-state fermented cereal starters contain highly complex microbial communities and enzymes. Very little is known, however, about the microbial dynamics related to environmental conditions, and cellulolytic communities have never been proposed to exist during cereal starter fermentation. In this study, we performed Illumina MiSeq sequencing combined with PCR-denaturing gradient gel electrophoresis to investigate microbiota, coupled with clone library construction to trace cellulolytic communities in both fermentation stages. A succession of microbial assemblages was observed during the fermentation of starters. Lactobacillales and Saccharomycetales dominated the initial stages, with a continuous decline in relative abundance. However, thermotolerant and drought-resistant Bacillales, Eurotiales, and Mucorales were considerably accelerated during the heating stages, and these organisms dominated until the end of fermentation. Enterobacteriales were consistently ubiquitous throughout the process. For the cellulolytic communities, only the genera Sanguibacter, Beutenbergia, Agrobacterium, and Erwinia dominated the initial fermentation stages. In contrast, stages at high incubation temperature induced the appearance and dominance of Bacillus, Aspergillus, and Mucor. The enzymatic dynamics of amylase and glucoamylase also showed a similar trend, with the activities clearly increased in the first 7 days and subsequently decreased until the end of fermentation. Furthermore, β-glucosidase activity continuously and significantly increased during the fermentation process. Evidently, cellulolytic potential can adapt to environmental conditions by changes in the community structure during the fermentation of starters. PMID:26002897

Physiological Characteristics of Projected Starters and Non-Starters in the Field Positions from a Division I Women’s Soccer Team

PubMed Central

RISSO, FABRICE G.; JALILVAND, FARZAD; ORJALO, ASHLEY J.; MORENO, MATTHEW R.; DAVIS, DESHAUN L.; BIRMINGHAM-BABAUTA, SAMANTHA A.; STOKES, JOHN J.; STAGE, ALYSSA A.; LIU, TRICIA M.; GIULIANO, DOMINIC V.; LAZAR, ADRINA; LOCKIE, ROBERT G.

2017-01-01

NCAA soccer features different substitution rules compared to FIFA-sanctioned matches, with a greater availability of players who can enter the game. This could influence the physiological characteristics of the field position starters (ST) and non-starters (NST) within a collegiate women’s team, which has not been previously analyzed. Thus, 22 field players from the same Division I women’s soccer squad completed: vertical and standing broad jumps; 30-meter (m) sprint (0–5, 0–10, 0–30 m intervals); pro-agility and 60-yard shuttle; and the Yo-Yo Intermittent Recovery Test Level 1. Players were defined into ST (n=10) and NST (n=12) by the coaching staff. A one-way ANOVA derived any significant (p≤0.05) between-group differences, and effect sizes were used for a magnitude-based inference analysis. Z-scores were also calculated to document worthwhile differences above or below the squad mean for the groups. The results showed no significant between-group differences for any of the performance tests. ST did have a worthwhile difference above the squad mean in the 0–10 and 0–30 m sprint intervals, while NST had a worthwhile difference below the squad mean in the 0–30 m interval. Physiological characteristics between ST and NST from the analyzed Division I squad were similar, although ST were generally faster. The similarities between ST and NST may be a function of the team’s training, in that all players may complete the same workouts. Nonetheless, if all players exhibit similar physiological capacities, with appropriate substitutions by the coach a collegiate team should be able to maintain a high work-rate throughout a match. PMID:28674601

Application of Lactic Acid Bacteria (LAB) in freshness keeping of tilapia fillets as sashimi

NASA Astrophysics Data System (ADS)

Cao, Rong; Liu, Qi; Chen, Shengjun; Yang, Xianqing; Li, Laihao

2015-08-01

Aquatic products are extremely perishable food commodities. Developing methods to keep the freshness of fish represents a major task of the fishery processing industry. Application of Lactic Acid Bacteria (LAB) as food preservative is a novel approach. In the present study, the possibility of using lactic acid bacteria in freshness keeping of tilapia fillets as sashimi was examined. Fish fillets were dipped in Lactobacillus plantarum 1.19 (obtained from China General Microbiological Culture Collection Center) suspension as LAB-treated group. Changes in K-value, APC, sensory properties and microbial flora were analyzed. Results showed that LAB treatment slowed the increase of K-value and APC in the earlier storage, and caused a smooth decrease in sensory score. Gram-negative bacteria dominated during refrigerated storage, with Pseudomonas and Aeromonas being relatively abundant. Lactobacillus plantarum 1.19 had no obvious inhibitory effect against these Gram-negatives. However, Lactobacillus plantarum 1.19 changed the composition of Gram-positive bacteria. No Micrococcus were detected and the proportion of Staphylococcus decreased in the spoiled LAB-treated samples. The period that tilapia fillets could be used as sashimi material extended from 24 h to 48 h after LAB treatment. The potential of using LAB in sashimi processing was confirmed.

Sustainable dual-use labs: neurovascular interventional capabilities within the cath lab.

PubMed

Lang, Stacey

2012-01-01

The inclusion of neurovascular interventional capabilities within the cath lab setting can be key to optimal utilization of resources, increased staff efficiency, and streamlined operations. When considering an expansion, look beyond the patient population traditionally associated with cardiac cath labs and consider the integration of programs outside cardiac alone--to create a true dual-use lab space. With proper planning, quality dual purpose equipment, appropriately trained staff, capable physicians, and strong leadership, an organization willing to embrace the challenge can build a truly extraordinary service.

Assessment of Characteristics and Functional Properties of Lactobacillus Species Isolated from Kimchi for Dairy Use

PubMed Central

Baick, Seung-Chun

2015-01-01

The objective of this study was to identify lactic acid bacteria (LAB) isolated from kimchi and to evaluate its characteristics and functional properties for application in fermented dairy products as a probiotic or commercial starter culture. Eight stains isolated from kimchi were selected through an investigation of phenotypic characteristics. Two strains (DK211 and DK303) were identified as Lactobacillus plantarum, another two (DK207 and DK215) as Lactobacillus paracasei, and one (DK301) as Lactobacillus sakei. The remaining three strains were identified as species of Weissella. All selected Lactobacillus strains had acid and bile tolerance, even though there was wide variation in the ability of each strain. DK303 showed a remarkably higher proteolytic activity. There were no significant differences in β-galactosidase activity among the tested strains, except that DK301 showed no activity. Auto-aggregation varied between 82.1 and 90.0%, and hydrophobicity values ranged from 0.5 to 51.6%.The strongest auto-aggregation and hydrophobicity were observed in DK211. All selected strains showed better 1,1-diphenyl-2-picrylhydrzyl (DPPH) scavenging activity than commercial strains. DK211, DK215, DK301, and DK303 had effective inhibitory activity against all pathogens tested except E. coli. When selected strains were used for yogurt preparation as a single starter culture, the time required to reach target titratable acidity (0.9) was 11-12 h. The yogurt fermented with DK211 had favorable panelists ratings for most sensory attributes, which were comparable with yogurt fermented with a commercial strain. The results suggest that strains isolated from kimchi could be potential probiotic and starter cultures for use in yogurt manufacturing. PMID:26761848

Game Related Statistics Discriminating Between Starters and Nonstarters Players in Women’S National Basketball Association League (WNBA)

PubMed Central

Gòmez, Miguel-Ángel; Lorenzo, Alberto; Ortega, Enrique; Sampaio, Jaime; Ibàñez, Sergio-José

2009-01-01

The aim of the present study was to identify the game-related statistics that allow discriminating between starters and nonstarter players in women’s basketball when related to winning or losing games and best or worst teams. The sample comprised all 216 regular season games from the 2005 Women’s National Basketball Association League (WNBA). The game-related statistics included were 2- and 3- point field-goals (both successful and unsuccessful), free-throws (both successful and unsuccessful), defensive and offensive rebounds, assists, blocks, fouls, steals, turnovers and minutes played. Results from multivariate analysis showed that when best teams won, the discriminant game-related statistics were successful 2-point field-goals (SC = 0.47), successful free-throws (SC = 0.44), fouls (SC = -0.41), assists (SC = 0.37), and defensive rebounds (SC = 0.37). When the worst teams won, the discriminant game-related statistics were successful 2-point field- goals (SC = 0.37), successful free-throws (SC = 0.45), assists (SC = 0.58), and steals (SC = 0.35). The results showed that the successful 2-point field-goals, successful free-throws and the assists were the most powerful variables discriminating between starters and nonstarters. These specific characteristics helped to point out the importance of starters’ players shooting and passing ability during competitions. Key points The players’ game-related statistical profile varied according to team status, game outcome and team quality in women’s basketball. The results of this work help to point out the different player’s performance described in women’s basketball compared with men’s basketball. The results obtained enhance the importance of starters and nonstarters contribution to team’s performance in different game contexts. Results showed the power of successful 2-point field-goals, successful free-throws and assists discriminating between starters and nonstarters in all the analyses. PMID:24149538

Lab at Home: Hardware Kits for a Digital Design Lab

ERIC Educational Resources Information Center

Oliver, J. P.; Haim, F.

2009-01-01

An innovative laboratory methodology for an introductory digital design course is presented. Instead of having traditional lab experiences, where students have to come to school classrooms, a "lab at home" concept is proposed. Students perform real experiments in their own homes, using hardware kits specially developed for this purpose. They…

Engaging with science: High school students in summer lab internships

NASA Astrophysics Data System (ADS)

Bequette, Marjorie Bullitt

Years of research and rhetoric have suggested that students should be given the opportunity to work with practicing scientists as a way to develop more sophisticated ideas about the nature of science, yet little research about these experiences exists. This project uses a case study approach to examine the experience of eight high school students working part-time during one summer as research assistants in biomedical laboratories. The students completed small research studies under the supervision of scientist-mentors. This dissertation explores questions related to how these students learned to work in a lab, in what ways they grew to understand this scientific context, and how their own relationships with science changed. The goal of looking at these young adults' summer experiences in science labs is to make suggestions for three settings: programs like this one, where high school students work closely with scientists in lab settings; other programs where scientists and students work together; and science education more generally. Analysis of pre- and post-interviews with students, and extensive observations of their laboratory work, suggests that students develop new ideas about the culture of science and the day-to-day workings of the labs. These ideas hold potential power for the students, and other participants in both similar and different educational settings, as they prepare for lives as scientifically engaged adults.

LCOGT Imaging Lab

NASA Astrophysics Data System (ADS)

Tufts, Joseph R.; Lobdill, Rich; Haldeman, Benjamin J.; Haynes, Rachel; Hawkins, Eric; Burleson, Ben; Jahng, David

2008-07-01

The Las Cumbres Observatory Global Telescope Network (LCOGT) is an ambitious project to build and operate, within 5 years, a worldwide robotic network of 50 0.4, 1, and 2 m telescopes sharing identical instrumentation and optimized for precision photometry of time-varying sources. The telescopes, instrumentation, and software are all developed in house with two 2 m telescopes already installed. The LCOGT Imaging Lab is responsible for assembly and characterization of the network's cameras and instrumentation. In addition to a fully equipped CNC machine shop, two electronics labs, and a future optics lab, the Imaging Lab is designed from the ground up to be a superb environment for bare detectors, precision filters, and assembled instruments. At the heart of the lab is an ISO class 5 cleanroom with full ionization. Surrounding this, the class 7 main lab houses equipment for detector characterization including QE and CTE, and equipment for measuring transmission and reflection of optics. Although the first science cameras installed, two TEC cooled e2v 42-40 deep depletion based units and two CryoTiger cooled Fairchild Imaging CCD486-BI based units, are from outside manufacturers, their 18 position filter wheels and the remainder of the network's science cameras, controllers, and instrumentation will be built in house. Currently being designed, the first generation LCOGT cameras for the network's 1 m telescopes use existing CCD486-BI devices and an in-house controller. Additionally, the controller uses digital signal processing to optimize readout noise vs. speed, and all instrumentation uses embedded microprocessors for communication over ethernet.

SciStarter 2.0: A Digital Platform to Foster and Study Sustained Engagement in Citizen Science

NASA Astrophysics Data System (ADS)

Hoffman, C.

2016-12-01

SciStarter is a popular online hotspot for citizen science. As a Match.com meets Amazon for citizen science projects, we connect the millions of citizen scientists to thousands of projects and events, and to the resources they need to participate. These opportunities represent ways for the general public from kids to adults to get involved in scientific research. Recently, SciStarter developed a new digital infrastructure to support sustained engagement in citizen science, and research into the behaviors and motivations of participants. The new digital infrastructure of SciStarter includes contribution tracking tools to make it easier to participate in multiple projects, enhanced GIS information to promote locally relevant projects, an online personal dashboard to keep track of contributions, and the use of these tools (contribution tracking, GIS, dashboard) by project owners and researchers to better understand and respond to the needs and interests of citizen science participants. We will provide an overview of these tools and the research behind their development. We will then explore how these new tools advance citizen science towards a future with more pathways to participatory policymaking, expanded access to informal STEM experiences, and lowered barriers to citizen science. Finally, we will present the research questions that can and will be answered through the site by practitioners in the diverse science and citizen science fields.

Inexpensive DAQ based physics labs

NASA Astrophysics Data System (ADS)

Lewis, Benjamin; Clark, Shane

2015-11-01

Quality Data Acquisition (DAQ) based physics labs can be designed using microcontrollers and very low cost sensors with minimal lab equipment. A prototype device with several sensors and documentation for a number of DAQ-based labs is showcased. The device connects to a computer through Bluetooth and uses a simple interface to control the DAQ and display real time graphs, storing the data in .txt and .xls formats. A full device including a larger number of sensors combined with software interface and detailed documentation would provide a high quality physics lab education for minimal cost, for instance in high schools lacking lab equipment or students taking online classes. An entire semester’s lab course could be conducted using a single device with a manufacturing cost of under $20.

Four Longitudinal Studies of the Starter Approach, a Beginning Reading Strategy for Nonreaders.

ERIC Educational Resources Information Center

Foley, Christy L.

To highlight the versatility of the Starter Approach to reading, a one-on-one beginning reading strategy for use with a nonreader of any age, this document describes the approach in detail and then briefly describes four longitudinal studies that used it. The introduction notes that the procedure combines successful components of popular,…

MatLab Script and Functional Programming

NASA Technical Reports Server (NTRS)

Shaykhian, Gholam Ali

2007-01-01

MatLab Script and Functional Programming: MatLab is one of the most widely used very high level programming languages for scientific and engineering computations. It is very user-friendly and needs practically no formal programming knowledge. Presented here are MatLab programming aspects and not just the MatLab commands for scientists and engineers who do not have formal programming training and also have no significant time to spare for learning programming to solve their real world problems. Specifically provided are programs for visualization. The MatLab seminar covers the functional and script programming aspect of MatLab language. Specific expectations are: a) Recognize MatLab commands, script and function. b) Create, and run a MatLab function. c) Read, recognize, and describe MatLab syntax. d) Recognize decisions, loops and matrix operators. e) Evaluate scope among multiple files, and multiple functions within a file. f) Declare, define and use scalar variables, vectors and matrices.

Microbiota Dynamics Associated with Environmental Conditions and Potential Roles of Cellulolytic Communities in Traditional Chinese Cereal Starter Solid-State Fermentation.

PubMed

Li, Pan; Liang, Hebin; Lin, Wei-Tie; Feng, Feng; Luo, Lixin

2015-08-01

Traditional Chinese solid-state fermented cereal starters contain highly complex microbial communities and enzymes. Very little is known, however, about the microbial dynamics related to environmental conditions, and cellulolytic communities have never been proposed to exist during cereal starter fermentation. In this study, we performed Illumina MiSeq sequencing combined with PCR-denaturing gradient gel electrophoresis to investigate microbiota, coupled with clone library construction to trace cellulolytic communities in both fermentation stages. A succession of microbial assemblages was observed during the fermentation of starters. Lactobacillales and Saccharomycetales dominated the initial stages, with a continuous decline in relative abundance. However, thermotolerant and drought-resistant Bacillales, Eurotiales, and Mucorales were considerably accelerated during the heating stages, and these organisms dominated until the end of fermentation. Enterobacteriales were consistently ubiquitous throughout the process. For the cellulolytic communities, only the genera Sanguibacter, Beutenbergia, Agrobacterium, and Erwinia dominated the initial fermentation stages. In contrast, stages at high incubation temperature induced the appearance and dominance of Bacillus, Aspergillus, and Mucor. The enzymatic dynamics of amylase and glucoamylase also showed a similar trend, with the activities clearly increased in the first 7 days and subsequently decreased until the end of fermentation. Furthermore, β-glucosidase activity continuously and significantly increased during the fermentation process. Evidently, cellulolytic potential can adapt to environmental conditions by changes in the community structure during the fermentation of starters. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Culturable Gut Microbiota Diversity in Zebrafish

PubMed Central

Sørby, Jan Roger Torp; Aleström, Peter; Sørum, Henning

2012-01-01

Abstract The zebrafish (Danio rerio) is an increasingly used laboratory animal model in basic biology and biomedicine, novel drug development, and toxicology. The wide use has increased the demand for optimized husbandry protocols to ensure animal health care and welfare. The knowledge about the correlation between culturable zebrafish intestinal microbiota and health in relation to environmental factors and management procedures is very limited. A semi-quantitative level of growth of individual types of bacteria was determined and associated with sampling points. A total of 72 TAB line zebrafish from four laboratories (Labs A–D) in the Zebrafish Network Norway were used. Diagnostic was based on traditional bacterial culture methods and biochemical characterization using commercial kits, followed by 16S rDNA gene sequencing from pure subcultures. Also selected Gram-negative isolates were analyzed for antibiotic susceptibility to 8 different antibiotics. A total of 13 morphologically different bacterial species were the most prevalent: Aeromonas hydrophila, Aeromonas sobria, Vibrio parahaemolyticus, Photobacterium damselae, Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas luteola, Comamonas testosteroni, Ochrobactrum anthropi, Staphylococcus cohnii, Staphylococcus epidermidis, Staphylococcus capitis, and Staphylococcus warneri. Only Lab B had significantly higher levels of total bacterial growth (OR=2.03), whereas numbers from Lab C (OR=1.01) and Lab D (OR=1.12) were found to be similar to the baseline Lab A. Sexually immature individuals had a significantly higher level of harvested total bacterial growth than mature fish (OR=0.82), no statistically significant differences were found between male and female fish (OR=1.01), and the posterior intestinal segment demonstrated a higher degree of culturable bacteria than the anterior segment (OR=4.1). Multiple antibiotic (>3) resistance was observed in 17% of the strains. We propose that a rapid

Culturable gut microbiota diversity in zebrafish.

PubMed

Cantas, Leon; Sørby, Jan Roger Torp; Aleström, Peter; Sørum, Henning

2012-03-01

The zebrafish (Danio rerio) is an increasingly used laboratory animal model in basic biology and biomedicine, novel drug development, and toxicology. The wide use has increased the demand for optimized husbandry protocols to ensure animal health care and welfare. The knowledge about the correlation between culturable zebrafish intestinal microbiota and health in relation to environmental factors and management procedures is very limited. A semi-quantitative level of growth of individual types of bacteria was determined and associated with sampling points. A total of 72 TAB line zebrafish from four laboratories (Labs A-D) in the Zebrafish Network Norway were used. Diagnostic was based on traditional bacterial culture methods and biochemical characterization using commercial kits, followed by 16S rDNA gene sequencing from pure subcultures. Also selected Gram-negative isolates were analyzed for antibiotic susceptibility to 8 different antibiotics. A total of 13 morphologically different bacterial species were the most prevalent: Aeromonas hydrophila, Aeromonas sobria, Vibrio parahaemolyticus, Photobacterium damselae, Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas luteola, Comamonas testosteroni, Ochrobactrum anthropi, Staphylococcus cohnii, Staphylococcus epidermidis, Staphylococcus capitis, and Staphylococcus warneri. Only Lab B had significantly higher levels of total bacterial growth (OR=2.03), whereas numbers from Lab C (OR=1.01) and Lab D (OR=1.12) were found to be similar to the baseline Lab A. Sexually immature individuals had a significantly higher level of harvested total bacterial growth than mature fish (OR=0.82), no statistically significant differences were found between male and female fish (OR=1.01), and the posterior intestinal segment demonstrated a higher degree of culturable bacteria than the anterior segment (OR=4.1). Multiple antibiotic (>3) resistance was observed in 17% of the strains. We propose that a rapid conventional

Experiences with lab-centric instruction

NASA Astrophysics Data System (ADS)

Titterton, Nathaniel; Lewis, Colleen M.; Clancy, Michael J.

2010-06-01

Lab-centric instruction emphasizes supervised, hands-on activities by substituting lab for lecture time. It combines a multitude of pedagogical techniques into the format of an extended, structured closed lab. We discuss the range of benefits for students, including increased staff interaction, frequent and varied self-assessments, integrated collaborative activities, and a systematic sequence of activities that gradually increases in difficulty. Instructors also benefit from a deeper window into student progress and understanding. We follow with discussion of our experiences in courses at U.C. Berkeley, and using data from some of these investigate the effects of lab-centric instruction on student learning, procrastination, and course pacing. We observe that the lab-centric format helped students on exams but hurt them on extended programming assignments, counter to our hypothesis. Additionally, we see no difference in self-ratings of procrastination and limited differences in ratings of course pace. We do find evidence that the students who choose to attend lab-centric courses are different in several important ways from students who choose to attend the same course in a non-lab-centric format.

Subsequent growth performance and digestive physiology of broilers fed on starter diets containing spray-dried porcine plasma as a substitute for meat meal.

PubMed

Beski, S S M; Swick, R A; Iji, P A

2015-01-01

A 4 × 2 factorial experiment was conducted to investigate the effect of inclusion of spray-dried porcine plasma (SDPP), in lieu of meat meal, in the starter diet on performance and digestive physiology of broiler chickens between hatch and 35 d of age. Four levels of SDPP (0, 5, 10 or 20 g/kg) were included in the starter diets in lieu of meat meal on either wheat- or maize-based diets. Over the first 10 d, and throughout the 35-d experimental period, birds gained more body weight with increasing concentrations of SDPP regardless to the type of grain used. Inclusion of SDPP in the starter diet markedly improved feed per gain in the starter phase and across the 35-d study. There was no significant effect of the type of grain and its interaction with SDPP on the body weight gain and feed per gain for the two assessed periods. At d 10, the relative weight of the gizzard+proventriculus, spleen and liver increased with increasing concentrations of SDPP. At 24 d of age, the grain and SDPP inclusion significantly interacted, depressing the weight of bursa and spleen in birds that received the highest concentration of SDPP in the maize-based diet. Birds fed on the maize-based diets had higher relative weight of pancreas than those on the wheat-based diets. Increasing concentrations of SDPP in the starter diet improved the activities of maltase, sucrase and alkaline phosphatase at 24 d of age. The interaction of grain and SDPP concentration was significant for sucrase activity in birds on the wheat-based diets. Chickens on maize-based diets had higher alkaline phosphatase and maltase activities than those on wheat-based diets. Chicks that were offered SDPP-containing starter diets had longer villi, deeper crypts and lower villi/crypt than the control at 24 d of age regardless of the grain type used. Furthermore, longer villi and larger villi/crypt were found in chicken groups fed on wheat-based diets than those on maize-based diets. Chickens on maize-based diets had higher

Analysis of bacterial and fungal communities in Marcha and Thiat, traditionally prepared amylolytic starters of India.

PubMed

Sha, Shankar Prasad; Jani, Kunal; Sharma, Avinash; Anupma, Anu; Pradhan, Pooja; Shouche, Yogesh; Tamang, Jyoti Prakash

2017-09-08

Marcha and thiat are traditionally prepared amylolytic starters use for production of various ethnic alcoholic beverages in Sikkim and Meghalaya states in India. In the present study we have tried to investigate the bacterial and fungal community composition of marcha and thiat by using high throughput sequencing. Characterization of bacterial community depicts phylum Proteobacteria is the most dominant in both marcha (91.4%) and thiat (53.8%), followed by Firmicutes, and Actinobacteria. Estimates of fungal community composition showed Ascomycota as the dominant phylum. Presence of Zygomycota in marcha distinguishes it from the thiat. The results of NGS analysis revealed dominance of yeasts in marcha whereas molds out numbers in case of thiat. This is the first report on microbial communities of traditionally prepared amylolytic starters of India using high throughput sequencing.

EarthLabs: A National Model for Earth Science Lab Courses

NASA Astrophysics Data System (ADS)

McDaris, J. R.; Dahlman, L.; Barstow, D.

2008-12-01

As a response to the need for more rigorous, inquiry-based high school Earth science courses, a coalition of scientists, educators, and five states have created EarthLabs, a set of pilot modules that can serve as a national model for lab-based science courses. The content of EarthLabs chapters focuses on Earth system science and environmental literacy and conforms to the National Science Education Standards as well as the states' curriculum frameworks. The effort is funded by NOAA's Environmental Literacy program. The pilot modules present activities on Corals, Drought, Fisheries, and Hurricanes. The Fisheries and Hurricanes units were reviewed and field-tested by educators in Texas and Arizona. The feedback from this evaluation led to revisions of these units and guided development of the Corals and Drought chapters. Each module consists of activities that use online data sets, satellite imagery, web-based readings, and hands-on laboratory experiments. The project comprises two separate websites, one for the instructor and one for students. The instructor's site contains the pedagogical underpinnings for each lab including teaching materials, assessment strategies, and the alignment of activities with state and national science standards. The student site provides access to all materials that students need to complete the activities or, in the case of the hands-on labs, where they access additional information to help extend their learning. There are also formative and summative questions embedded in the student webpages to help scaffold learning through the activities.

Improving the Quality of Lab Reports by Using Them as Lab Instructions

NASA Astrophysics Data System (ADS)

Haagen-Schuetzenhoefer, Claudia

2012-10-01

Lab exercises are quite popular in teaching science. Teachers have numerous goals in mind when teaching science laboratories. Nevertheless, empirical research draws a heterogeneous picture of the benefits of lab work. Research has shown that it does not necessarily contribute to the enhancement of practical abilities or content knowledge. Lab activities are frequently based on recipe-like, step-by-step instructions ("cookbook style"), which do not motivate students to engage cognitively. Consequently, students put the emphasis on "task completion" or "manipulating equipment."2

The AskA Starter Kit: How To Build and Maintain Digital Reference Services.

ERIC Educational Resources Information Center

Lankes, R. David; Kasowitz, Abby S.

This Starter Kit is designed to help organizations and individuals who wish to offer human-mediated information services via the Internet to users in the K-12 community. A six-step process is proposed for organizations to follow in creating an "AskA" service. This process addresses all aspects involved in building and maintaining an AskA…

Biodiversity, ecological determinants, and metabolic exploitation of sourdough microbiota.

PubMed

De Vuyst, L; Vrancken, G; Ravyts, F; Rimaux, T; Weckx, S

2009-10-01

Sourdough is a microbial ecosystem of lactic acid bacteria (LAB) and yeasts in a matrix of mainly cereal flour and water. Culture-dependent and culture-independent microbiological analysis together with metabolite target analyses of different sourdoughs enabled to understand this complex fermentation process. It is difficult to link the species diversity of the sourdough microbiota with the (geographical) type of sourdough and the flour used, although the type and quality of the latter is the main source of autochthonous LAB in spontaneous sourdough fermentations and plays a key role in establishing stable microbial consortia within a short time. Carbohydrate fermentation targeted towards maltose catabolism, the use of external alternative electron acceptors, amino acid transamination reactions, and/or the arginine deiminase pathway are metabolic activities that favour energy production, cofactor (re)cycling, and/or tolerance towards acid stress, and hence contribute to the competitiveness and dominance of certain species of LAB found in sourdoughs. Also, microbial interactions play an important role. The availability of genome sequences for several LAB species that are of importance in sourdough as well as technological advances in the fields of functional genomics, transcriptomics, and proteomics enable new approaches to study sourdough fermentations beyond the single species level and will allow an integral analysis of the metabolic activities and interactions taking place in sourdough. Finally, the implementation of selected starter cultures in sourdough technology is of pivotal importance for the industrial production of sourdoughs to be used as flavour carrier, texture-improving, or health-promoting dough ingredient.

Characterization of amygdalin-degrading Lactobacillus species.

PubMed

Menon, R; Munjal, N; Sturino, J M

2015-02-01

Cyanogenic glycosides are phytotoxic secondary metabolites produced by some crop plants. The aim of this study was to identify lactic acid bacteria (LAB) capable of catabolizing amygdalin, a model cyanogenic glycoside, for use in the biodetoxification of amygdalin-containing foods and feeds. Amygdalin-catabolizing lactobacilli were characterized using a combination of cultivation-dependent and molecular assays. Lactobacillus paraplantarum and Lactobacillus plantarum grew robustly on amygdalin (Amg(+)), while other LAB species typically failed to catabolize amygdalin (Amg(-)). Interestingly, high concentrations of amygdalin and two of its metabolic derivatives (mandelonitrile and benzaldehyde) inhibited the growth of Lact. plantarum RENO 0093. The differential regulation of genes tentatively involved in cyanohydrin metabolism illustrated that the metabolism of amygdalin- and glucose-grown cultures also differed significantly. Amygdalin fermentation was a relatively uncommon phenotype among the LAB and generally limited to strains from the Lact. plantarum group. Phenotype microarrays (PM) enabled strain-level discrimination between closely related strains within a species and suggested that phenotypic differences might affect niche specialization. Amygdalin-degrading lactobacilli with practical application in the biodetoxification of amygdalin were characterized. These strains show potential for use as starter cultures to improve the safety of foods and feeds. © 2014 The Society for Applied Microbiology.

Multilayer-based lab-on-a-chip systems for perfused cell-based assays

NASA Astrophysics Data System (ADS)

Klotzbach, Udo; Sonntag, Frank; Grünzner, Stefan; Busek, Mathias; Schmieder, Florian; Franke, Volker

2014-12-01

A novel integrated technology chain of laser-microstructured multilayer foils for fast, flexible, and low-cost manufacturing of lab-on-a-chip devices especially for complex cell and tissue culture applications, which provides pulsatile fluid flow within physiological ranges at low media-to-cells ratio, was developed and established. Initially the microfluidic system is constructively divided into individual layers, which are formed by separate foils or plates. Based on the functional boundary conditions and the necessary properties of each layer, their corresponding foils and plates are chosen. In the third step, the foils and plates are laser microstructured and functionalized from both sides. In the fourth and last manufacturing step, the multiple plates and foils are joined using different bonding techniques like adhesive bonding, welding, etc. This multilayer technology together with pneumatically driven micropumps and valves permits the manufacturing of fluidic structures and perfusion systems, which spread out above multiple planes. Based on the established lab-on-a-chip platform for perfused cell-based assays, a multilayer microfluidic system with two parallel connected cell culture chambers was successfully implemented.

Characterisation of microbial communities in Chinese liquor fermentation starters Daqu using nested PCR-DGGE.

PubMed

Zhang, Liqiang; Wu, Chongde; Ding, Xiaofei; Zheng, Jia; Zhou, Rongqing

2014-12-01

In this study, characterises of the microbial community structures of three typical Chinese liquor Daqu, as well as different kinds of light flavour Daqu were investigated using nested PCR-denaturing gradient gel electrophoresis (DGGE). The results showed that microbial diversity was considerably different, and the microfloral compositions were highly variable among various Daqu. Lactic acid bacteria, which accounted for 30.95 % of all identified bacteria, were dominant in all Daqu samples, whereas Bacillus species were also predominant in the Luzhou (14.8 %) and Langjiu Daqu (18.2 %). Citrobacter and Burkholderia were first identified in light flavour Daqu. Aspergillus was the dominant moulds, and the non-Saccharomyces yeast species, Saccharomycopsis fibuligera, Wallemia sebi, Wallemia muriae, and Pichia subpelliculosa, were the dominant yeasts. Rasamsonia, Galactomyces, Geotrichum and Wallemia were first identified using nested PCR-DGGE. Cluster analysis indicated that the microbial community structures of different Daqu samples exhibited some differences. These may be ascribed to the different peak production temperatures, raw material constituents and microhabitats around the liquor enterprises. The current study provides insights into the microbial community structures of three typical Daqu samples, and may facilitate the development of starter cultures for manufacturing Chinese liquor.

Investigation of hazards associated with plastic bonded starter mix manufacturing processes

NASA Technical Reports Server (NTRS)

1971-01-01

An investigation to determine the hazards potential evaluation of plastic bonded starter mix (PBSM) production processes and the application to the M18 and M7A3 grenades is reported. The investigation indicated: (1) the materials with the greatest hazards characteristics, (2) process operating stations most likely to initiate hazardous conditions, (3) the test program required to examine ignition characteristics and process hazards, and (4) the method of handling the accumulated information from testing and safety analyses.

Lab Report Blues

ERIC Educational Resources Information Center

Diaz, Andrew

2004-01-01

For middle school students, writing a formal lab report can be challenging. For middle level teachers, reading students lab reports can be overwhelming. After grading report after report with incomplete procedures, incorrect graphs, and missing conclusions, the author's frustration level was at an all-time high. Ready to try anything, he thought,…

Reforming Cookbook Labs

ERIC Educational Resources Information Center

Peters, Erin

2005-01-01

Deconstructing cookbook labs to require the students to be more thoughtful could break down perceived teacher barriers to inquiry learning. Simple steps that remove or disrupt the direct transfer of step-by-step procedures in cookbook labs make students think more critically about their process. Through trials in the author's middle school…

Inclusion of tallow and soybean oil to calf starters fed to dairy calves from birth to four months of age on calf performance and digestion.

PubMed

Hill, T M; Bateman, H G; Aldrich, J M; Quigley, J D; Schlotterbeck, R L

2015-07-01

Energy demands for calves can increase during periods of heat and cold stress. One way to potentially increase energy intake is to increase the energy density of the feed with fat. Trial 1a compared a control starter with no added fat or oil (CON) to starters with 2% tallow (TAL) and 2% soybean oil (SBO). Starters were 20% crude protein (CP) and 45 to 47% starch. Male Holstein calves that were initially 3 to 5d of age were fed a 27% CP, 17% fat milk replacer at 0.66kg of dry matter daily and fully weaned by 42d of a 56-d trial. Trial 1b estimated the digestion of the diets (employed chromic oxide as an indigestible digesta flow marker) using a subset of 5 weaned calves per treatment between d 52 and 56. Trial 2 used Holstein calves initially 59 to 61d of age fed starters CON and SBO blended with 5% chopped grass hay over a 56-d trial. Trial 3 used Holstein calves initially 59 to 61d of age fed starters CON and TAL blended with 5% chopped grass hay over a 56-d trial. Treatments were compared using repeated measures (where appropriate) in a completely randomized design. In trials 1a and 1b, preplanned contrasts compared CON versus TAL and CON versus SBO. Compared with CON, calves fed SBO had reduced starter intake, average daily gain, and digestion of dry matter, organic matter, and CP before 8wk of age. Compared with CON, calves fed SBO had reduced average daily gain and change in hip width from 2 to 4 mo of age. Compared with CON, calves fed TAL had reduced average daily gain and tended to have reduced change in hip width from 2 to 4 mo of age. Calculated metabolizable energy intake was not increased in any trial by added fat or oil. Tallow and soybean oil inclusion at 2% of the starter feed was not advantageous for calf growth before 4 mo of age. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Purification and characterization of an alpha-amylase of Pichia burtonii isolated from the traditional starter "murcha" in Nepal.

PubMed

Takeuchi, Akiko; Shimizu-Ibuka, Akiko; Nishiyama, Yoshitaka; Mura, Kiyoshi; Okada, Sanae; Tokue, Chiyoko; Arai, Soichi

2006-12-01

Among more than 20 yeast strains isolated from the traditional starter "murcha" in Nepal, we characterized a yeast that might be involved in saccharification. This strain, identified as Pichia burtonii, produced an extracellular amylolytic enzyme when cultured in the presence of starch in the medium. Since no amylase secreted by P. burtonii has yet been reported, we purified the enzyme and determined its N-terminal amino acid sequence. Together with the results of a hydrolyzing activity assay toward various substrates, it was found to be an alpha-amylase. The purified enzyme, named Pichia burtonii alpha-amylase (PBA), was a glycoprotein with an apparent molecular mass of 51 kDa. Enzyme activity was optimal at pH 5.0 at 40 degrees C. The enzyme retained 80% of its original activity after incubation under the optimal pH condition at 50 degrees C for 30 min. The activity was inhibited by metal ions such as Cd(2+), Cu(2+), Hg(2+), Al(3+), and Zn(2+).

Antimicrobial Activity and Chemical Composition of "Kpètè-Kpètè": A Starter of Benin Traditional Beer Tchoukoutou.

PubMed

N'tcha, Christine; Sina, Haziz; Kayodé, Adéchola Pierre Polycarpe; Gbenou, Joachim D; Baba-Moussa, Lamine

2017-01-01

The aim of this study was to investigate the antibacterial effect of the crude starter " kpètè-kpètè " and lactic acid bacteria used during the production of "tchoukoutou." To achieve this, a total of 11 lactic acid bacteria and 40 starter samples were collected from four communes. The samples were tested on 29 gram + and - strains by disk diffusion method. The minimum inhibitory and bactericidal concentrations of starter and lactic acid bacteria were determined by conventional methods. Organic acids, sugar, and volatile compounds were determined using the HPLC method. The "kpètè-kpètè" displays a high antibacterial activity against the tested strains. The most sensitive strain was S. epidermidis (12.5 mm) whereas the resistance strain was Proteus mirabilis (8 mm). All the tested ferment has not any inhibitory effect on Enterococcus faecalis . The lactic acid bacteria isolates of Parakou showed the highest (17.48 mm) antibacterial activity whereas the smallest diameter was obtained with the ferment collected from Boukoumbé (9.80 mm). The starters' chemical screening revealed the presence of tannins, anthocyanin flavonoids, triterpenes, steroids, reducing compounds, and mucilage O-glycosides. These compounds are probably the source of recorded inhibition effect. The lactic acid bacteria of the "kpètè-kpètè" could be used to develop a food ingredient with probiotic property.

Status of chemistry lab safety in Nepal.

PubMed

Kandel, Krishna Prasad; Neupane, Bhanu Bhakta; Giri, Basant

2017-01-01

Chemistry labs can become a dangerous environment for students as the lab exercises involve hazardous chemicals, glassware, and equipment. Approximately one hundred thousand students take chemistry laboratory classes annually in Nepal. We conducted a survey on chemical lab safety issues across Nepal. In this paper, we assess the safety policy and equipment, protocols and procedures followed, and waste disposal in chemistry teaching labs. Significant population of the respondents believed that there is no monitoring of the lab safety in their lab (p<0.001). Even though many labs do not allow food and beverages inside lab and have first aid kits, they lack some basic safety equipment. There is no institutional mechanism to dispose lab waste and chemical waste is disposed haphazardly. Majority of the respondents believed that the safety training should be a part of educational training (p = 0.001) and they would benefit from short course and/or workshop on lab safety (p<0.001).

Status of chemistry lab safety in Nepal

PubMed Central

Kandel, Krishna Prasad; Neupane, Bhanu Bhakta

2017-01-01

Chemistry labs can become a dangerous environment for students as the lab exercises involve hazardous chemicals, glassware, and equipment. Approximately one hundred thousand students take chemistry laboratory classes annually in Nepal. We conducted a survey on chemical lab safety issues across Nepal. In this paper, we assess the safety policy and equipment, protocols and procedures followed, and waste disposal in chemistry teaching labs. Significant population of the respondents believed that there is no monitoring of the lab safety in their lab (p<0.001). Even though many labs do not allow food and beverages inside lab and have first aid kits, they lack some basic safety equipment. There is no institutional mechanism to dispose lab waste and chemical waste is disposed haphazardly. Majority of the respondents believed that the safety training should be a part of educational training (p = 0.001) and they would benefit from short course and/or workshop on lab safety (p<0.001). PMID:28644869

Biodiversity and technological potential of lactic acid bacteria isolated from spontaneously fermented amaranth sourdough.

PubMed

Ruiz Rodríguez, L; Vera Pingitore, E; Rollan, G; Martos, G; Saavedra, L; Fontana, C; Hebert, E M; Vignolo, G

2016-08-01

Spontaneous fermented sourdoughs prepared from amaranth flour were investigated for the presence of autochthonous lactic acid bacteria (LAB) predominating microbiota. The doughs were fermented with daily backslopping on a laboratory scale at 30°C for 10 days. LAB counts ranged from 2·60 to 8·54 log CFU g(-1) with a pH declined from 6·2 to 3·8 throughout fermentation. The combined use of randomly amplified polymorphic DNA (RAPD)-PCR analysis and sequence analysis of 16S rRNA was applied for LAB intraspecies differentiation and taxonomic identification, respectively. Enterococcus, Pediococcus and Lactobacillus species were present in amaranth sourdoughs (AS). After the first refreshment step, Lactobacillus plantarum dominated AS until the end of fermentation. In coincidence, when DGGE analysis was performed, the occurrence of a progressive change in bacterial communities allowed the selection of Lact. plantarum as a dominant species. Moreover, technological, functional and safety characteristics of representative RAPD-biotypes were investigated. Lact. plantarum CRL1898 was selected as a potential candidate for gluten-free amaranth sourdough starter. Nowadays, there is an increasing interest in ancient noncereal gluten-free (GF) crops such as amaranth, due to their reported nutritional and health benefits. However, the use of these grains is still limited to traditional foods and bread making processes that are not yet well standardized. Results on the dynamics of autochthonous lactic acid bacteria (LAB) microbiota during laboratory spontaneous amaranth sourdoughs (AS) fermentation will contribute to overcome challenges for GF-fermented products development. In addition, knowledge about LAB diversity involving Enterococcus, Pediococcus and Lactobacillus species, with Lactobacillus plantarum predominating during AS fermentation, and their technological and functional properties provides the basis for the selection of autochthonous strains as starters cultures

SenseLab

PubMed Central

Crasto, Chiquito J.; Marenco, Luis N.; Liu, Nian; Morse, Thomas M.; Cheung, Kei-Hoi; Lai, Peter C.; Bahl, Gautam; Masiar, Peter; Lam, Hugo Y.K.; Lim, Ernest; Chen, Huajin; Nadkarni, Prakash; Migliore, Michele; Miller, Perry L.; Shepherd, Gordon M.

2009-01-01

This article presents the latest developments in neuroscience information dissemination through the SenseLab suite of databases: NeuronDB, CellPropDB, ORDB, OdorDB, OdorMapDB, ModelDB and BrainPharm. These databases include information related to: (i) neuronal membrane properties and neuronal models, and (ii) genetics, genomics, proteomics and imaging studies of the olfactory system. We describe here: the new features for each database, the evolution of SenseLab’s unifying database architecture and instances of SenseLab database interoperation with other neuroscience online resources. PMID:17510162

Influence of different proteolytic strains of Streptococcus thermophilus in co-culture with Lactobacillus delbrueckii subsp. bulgaricus on the metabolite profile of set-yoghurt.

PubMed

Settachaimongkon, Sarn; Nout, M J Robert; Antunes Fernandes, Elsa C; Hettinga, Kasper A; Vervoort, Jacques M; van Hooijdonk, Toon C M; Zwietering, Marcel H; Smid, Eddy J; van Valenberg, Hein J F

2014-05-02

Proto-cooperation between Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus is one of the key factors that determine the fermentation process and final quality of yoghurt. In this study, the interaction between different proteolytic strains of S. thermophilus and L. delbrueckii subsp. bulgaricus was investigated in terms of microbial growth, acidification and changes in the biochemical composition of milk during set-yoghurt fermentation. A complementary metabolomics approach was applied for global characterization of volatile and non-volatile polar metabolite profiles of yoghurt associated with proteolytic activity of the individual strains in the starter cultures. The results demonstrated that only non-proteolytic S. thermophilus (Prt-) strain performed proto-cooperation with L. delbrueckii subsp. bulgaricus. The proto-cooperation resulted in significant higher populations of the two species, faster milk acidification, significant abundance of aroma volatiles and non-volatile metabolites desirable for a good organoleptic quality of yoghurt. Headspace SPME-GC/MS and (1)H NMR resulted in the identification of 35 volatiles and 43 non-volatile polar metabolites, respectively. Furthermore, multivariate statistical analysis allows discriminating set-yoghurts fermented by different types of starter cultures according to their metabolite profiles. Our finding underlines that selection of suitable strain combinations in yoghurt starters is important for achieving the best technological performance regarding the quality of product. Copyright © 2014 Elsevier B.V. All rights reserved.

Halbach array-based design and simulation of disc coreless permanen-magnet integrated starter generator

NASA Astrophysics Data System (ADS)

Li, Y. B.; Yang, Z. X.; Chen, W.; He, Q. Y.

2017-11-01

The functional performance, such as magnetic flux leakage, power density and efficiency, is related to the structural characteristics and design technique for the disc permanent magnet synchronous generators (PMSGs). Halbach array theory-based magnetic circuit structure is developed, and Maxwell3D simulation analysis approach of PMSG is proposed in this paper for integrated starter generator (ISG). The magnetization direction of adjacent permanent magnet is organized in difference of 45 degrees for focusing air gap side, and improving the performance of the generator. The magnetic field distribution and functional performance in load and/or unload conditions are simulated by Maxwell3D module. The proposed approach is verified by simulation analysis, the air gap flux density is 0.66T, and the phase voltage curve has the characteristics of a preferable sinusoidal wave and the voltage amplitude 335V can meet the design requirements while the disc coreless PMSG is operating at rated speed. And the developed magnetic circuit structure can be used for engineering design of the disc coreless PMSG to the integrated starter generator.

Anti-Obesity Effects of Starter Fermented Kimchi on 3T3-L1 Adipocytes

PubMed Central

Lee, Kyung-Hee; Song, Jia-Le; Park, Eui-Seong; Ju, Jaehyun; Kim, Hee-Young; Park, Kun-Young

2015-01-01

The anti-obesity effects of starter (Leuconostoc mesenteroides+Lactobacillus plantarum) fermented kimchi on 3T3-L1 adipocyte were studied using naturally fermented kimchi (NK), a functional kimchi (FK, NK supplemented with green tea), and FK supplemented with added starters (FKS). Oil red O staining and cellular levels of triglyceride (TG) and glycerol were used to evaluate the in vitro anti-obesity effects of these kimchis in 3T3-L1 cells. The expressions of adipogenesis/lipogenesis-related genes of peroxisome proliferator-active receptor (PPAR)-γ, CCAAT/enhance-binding protein (C/EBP)-α, and fatty acid synthase (FAS) were determined by RT-PCR. Kimchis, especially FKS, markedly decreased TG levels and increased levels of intracellular glycerol and lipid lipolysis. In addition, FKS also reduced the mRNA levels of PPAR-γ, C/EBP-α, and FAS, which are related to adipogenesis/lipogenesis in 3T3-L1 cells. These results suggest the anti-obesity effects of FKS were to due to enhanced lipolysis and reduced adipogenesis/lipogenesis in 3T3-L1 adipocytes. PMID:26770918

Does the pelleting process affect the nutritive value of a pre-starter diet for suckling piglets? Ex vivo studies on mineral absorption.

PubMed

Delgado-Andrade, Cristina; Rufián-Henares, José A; Nieto, Rosa; Aguilera, José F; Navarro, M Pilar; Seiquer, Isabel

2010-04-15

The effects of pelleting on the extent of the Maillard reaction (MR) and on calcium, magnesium and zinc solubility and absorption were analysed in a conventional pre-starter diet for suckling piglets. Development was tested measuring colour, absorbance (280/420 nm), fluorescence, residual free lysine, furosine, hydroxymethylfurfural (HMF) and furfural contents before and after pelleting. Fluorescence, absorbance and mineral solubility were also measured after in vitro digestion of diets. The effects on mineral absorption were tested using Caco-2 cells. MR indexes confirmed the development of the reaction during the pelleting of this particular diet compared with the meal diet. The CIE-Lab colour parameters showed a decrease in luminosity (L*) and progress of the colour to the red zone (a*) in the pelleted diet. A 36% decrease in free lysine content was observed. Significant correlations were observed between fluorescence intensity and furosine levels, HMF and furfural. The pelleting process did not modify calcium and magnesium solubility after in vitro digestion, but soluble zinc increased. The efficiency of calcium and zinc transport across Caco-2 cell monolayers was greater in the pelleted diet. Evidence of MR development is shown, resulting in various nutritional consequences. Optimisation of pelleting could result in a better formulation of diets for feedstuffs. (c) 2010 Society of Chemical Industry.

Distribution of Native Lactic Acid Bacteria in Wineries of Queretaro, Mexico and Their Resistance to Wine-Like Conditions

PubMed Central

Miranda-Castilleja, Dalia E.; Martínez-Peniche, Ramón Álvar; Aldrete-Tapia, J. A.; Soto-Muñoz, Lourdes; Iturriaga, Montserrat H.; Pacheco-Aguilar, J. R.; Arvizu-Medrano, Sofía M.

2016-01-01

Native lactic acid bacteria (LAB) are capable of growing during winemaking, thereby strongly affecting wine quality. The species of LAB present in musts, wines during malolactic fermentation (MLF), and barrels/filters were investigated in wineries from the emerging wine region of Queretaro, México using multiplex PCR and culture. The resistance to wine-like conditions (WLC): ethanol (10, 12, and 13%), SO2 (30 mg⋅l-1), and low pH (3.5) of native LAB strains was also studied. Five species were detected within 61 samples obtained: Oenococcus oeni, Lactobacillus plantarum, Pediococcus parvulus, Lactobacillus hilgardi, and Lactobacillus brevis. Four species (excepting L. brevis) were found in must; O. oeni and P. parvulus were ubiquitous in wine and L. plantarum and L. brevis were mainly present at the initial stage of MLF, while L. hilgardii was mostly detected at the advanced stage. Furthermore, some species detected in barrel/filter, prove them to be hazardous reservoirs. From 822 LAB isolates, only 119 resisted WLC with 10% ethanol; the number of strains able to grow in WLC with 13% ethanol decreased approximately by 50%, O. oeni being the most versatile species with 65% of resistant isolates, while Lactobacillus spp. and P. parvulus were the most strongly affected, especially those recovered from barrel/filter, with less than 10% of resistant isolates. This study evidences the presence of local strains able to be used as starter cultures, and also enabled the assessment of the risks derived from the presence of spoilage LAB strains resistant to WLC. PMID:27877164

Integrating Robotic Observatories into Astronomy Labs

NASA Astrophysics Data System (ADS)

Ruch, Gerald T.

2015-01-01

The University of St. Thomas (UST) and a consortium of five local schools is using the UST Robotic Observatory, housing a 17' telescope, to develop labs and image processing tools that allow easy integration of observational labs into existing introductory astronomy curriculum. Our lab design removes the burden of equipment ownership by sharing access to a common resource and removes the burden of data processing by automating processing tasks that are not relevant to the learning objectives.Each laboratory exercise takes place over two lab periods. During period one, students design and submit observation requests via the lab website. Between periods, the telescope automatically acquires the data and our image processing pipeline produces data ready for student analysis. During period two, the students retrieve their data from the website and perform the analysis. The first lab, 'Weighing Jupiter,' was successfully implemented at UST and several of our partner schools. We are currently developing a second lab to measure the age of and distance to a globular cluster.

Assessing the Challenges in the Application of Potential Probiotic Lactic Acid Bacteria in the Large-Scale Fermentation of Spanish-Style Table Olives.

PubMed

Rodríguez-Gómez, Francisco; Romero-Gil, Verónica; Arroyo-López, Francisco N; Roldán-Reyes, Juan C; Torres-Gallardo, Rosa; Bautista-Gallego, Joaquín; García-García, Pedro; Garrido-Fernández, Antonio

2017-01-01

This work studies the inoculation conditions for allowing the survival/predominance of a potential probiotic strain ( Lactobacillus pentosus TOMC-LAB2) when used as a starter culture in large-scale fermentations of green Spanish-style olives. The study was performed in two successive seasons (2011/2012 and 2012/2013), using about 150 tons of olives. Inoculation immediately after brining (to prevent wild initial microbiota growth) followed by re-inoculation 24 h later (to improve competitiveness) was essential for inoculum predominance. Processing early in the season (September) showed a favorable effect on fermentation and strain predominance on olives (particularly when using acidified brines containing 25 L HCl/vessel) but caused the disappearance of the target strain from both brines and olives during the storage phase. On the contrary, processing in October slightly reduced the target strain predominance on olives (70-90%) but allowed longer survival. The type of inoculum used (laboratory vs. industry pre-adapted) never had significant effects. Thus, this investigation discloses key issues for the survival and predominance of starter cultures in large-scale industrial fermentations of green Spanish-style olives. Results can be of interest for producing probiotic table olives and open new research challenges on the causes of inoculum vanishing during the storage phase.

Assessing the Challenges in the Application of Potential Probiotic Lactic Acid Bacteria in the Large-Scale Fermentation of Spanish-Style Table Olives

PubMed Central

Rodríguez-Gómez, Francisco; Romero-Gil, Verónica; Arroyo-López, Francisco N.; Roldán-Reyes, Juan C.; Torres-Gallardo, Rosa; Bautista-Gallego, Joaquín; García-García, Pedro; Garrido-Fernández, Antonio

2017-01-01

This work studies the inoculation conditions for allowing the survival/predominance of a potential probiotic strain (Lactobacillus pentosus TOMC-LAB2) when used as a starter culture in large-scale fermentations of green Spanish-style olives. The study was performed in two successive seasons (2011/2012 and 2012/2013), using about 150 tons of olives. Inoculation immediately after brining (to prevent wild initial microbiota growth) followed by re-inoculation 24 h later (to improve competitiveness) was essential for inoculum predominance. Processing early in the season (September) showed a favorable effect on fermentation and strain predominance on olives (particularly when using acidified brines containing 25 L HCl/vessel) but caused the disappearance of the target strain from both brines and olives during the storage phase. On the contrary, processing in October slightly reduced the target strain predominance on olives (70–90%) but allowed longer survival. The type of inoculum used (laboratory vs. industry pre-adapted) never had significant effects. Thus, this investigation discloses key issues for the survival and predominance of starter cultures in large-scale industrial fermentations of green Spanish-style olives. Results can be of interest for producing probiotic table olives and open new research challenges on the causes of inoculum vanishing during the storage phase. PMID:28567038

Changing Parent Attitudes and Improving Language and Intellectual Abilities of Culturally Disadvantaged Four-Year-Old Children Through Parent Involvement.

ERIC Educational Resources Information Center

McCarthy, Janet Lee Gorrell

The purposes of this study were to analyze parent involvement as it related to (1) the development of language abilities of culturally disadvantaged preschool children and (2) the intelligence test scores of these children and to analyze parent attitudes resulting from involvement. Nine hypotheses were tested. Forty-one 4-year-old Head Starters in…

Stress Physiology of Lactic Acid Bacteria

PubMed Central

Papadimitriou, Konstantinos; Alegría, Ángel; Bron, Peter A.; de Angelis, Maria; Gobbetti, Marco; Kleerebezem, Michiel; Lemos, José A.; Linares, Daniel M.; Ross, Paul; Stanton, Catherine; Turroni, Francesca; van Sinderen, Douwe; Varmanen, Pekka; Ventura, Marco; Zúñiga, Manuel; Tsakalidou, Effie

2016-01-01

SUMMARY Lactic acid bacteria (LAB) are important starter, commensal, or pathogenic microorganisms. The stress physiology of LAB has been studied in depth for over 2 decades, fueled mostly by the technological implications of LAB robustness in the food industry. Survival of probiotic LAB in the host and the potential relatedness of LAB virulence to their stress resilience have intensified interest in the field. Thus, a wealth of information concerning stress responses exists today for strains as diverse as starter (e.g., Lactococcus lactis), probiotic (e.g., several Lactobacillus spp.), and pathogenic (e.g., Enterococcus and Streptococcus spp.) LAB. Here we present the state of the art for LAB stress behavior. We describe the multitude of stresses that LAB are confronted with, and we present the experimental context used to study the stress responses of LAB, focusing on adaptation, habituation, and cross-protection as well as on self-induced multistress resistance in stationary phase, biofilms, and dormancy. We also consider stress responses at the population and single-cell levels. Subsequently, we concentrate on the stress defense mechanisms that have been reported to date, grouping them according to their direct participation in preserving cell energy, defending macromolecules, and protecting the cell envelope. Stress-induced responses of probiotic LAB and commensal/pathogenic LAB are highlighted separately due to the complexity of the peculiar multistress conditions to which these bacteria are subjected in their hosts. Induction of prophages under environmental stresses is then discussed. Finally, we present systems-based strategies to characterize the “stressome” of LAB and to engineer new food-related and probiotic LAB with improved stress tolerance. PMID:27466284

Stress Physiology of Lactic Acid Bacteria.

PubMed

Papadimitriou, Konstantinos; Alegría, Ángel; Bron, Peter A; de Angelis, Maria; Gobbetti, Marco; Kleerebezem, Michiel; Lemos, José A; Linares, Daniel M; Ross, Paul; Stanton, Catherine; Turroni, Francesca; van Sinderen, Douwe; Varmanen, Pekka; Ventura, Marco; Zúñiga, Manuel; Tsakalidou, Effie; Kok, Jan

2016-09-01

Lactic acid bacteria (LAB) are important starter, commensal, or pathogenic microorganisms. The stress physiology of LAB has been studied in depth for over 2 decades, fueled mostly by the technological implications of LAB robustness in the food industry. Survival of probiotic LAB in the host and the potential relatedness of LAB virulence to their stress resilience have intensified interest in the field. Thus, a wealth of information concerning stress responses exists today for strains as diverse as starter (e.g., Lactococcus lactis), probiotic (e.g., several Lactobacillus spp.), and pathogenic (e.g., Enterococcus and Streptococcus spp.) LAB. Here we present the state of the art for LAB stress behavior. We describe the multitude of stresses that LAB are confronted with, and we present the experimental context used to study the stress responses of LAB, focusing on adaptation, habituation, and cross-protection as well as on self-induced multistress resistance in stationary phase, biofilms, and dormancy. We also consider stress responses at the population and single-cell levels. Subsequently, we concentrate on the stress defense mechanisms that have been reported to date, grouping them according to their direct participation in preserving cell energy, defending macromolecules, and protecting the cell envelope. Stress-induced responses of probiotic LAB and commensal/pathogenic LAB are highlighted separately due to the complexity of the peculiar multistress conditions to which these bacteria are subjected in their hosts. Induction of prophages under environmental stresses is then discussed. Finally, we present systems-based strategies to characterize the "stressome" of LAB and to engineer new food-related and probiotic LAB with improved stress tolerance. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

An experimental evaluation of the performance deficit of an aircraft engine starter turbine

NASA Technical Reports Server (NTRS)

Hass, J. E.; Roelke, R. J.; Hermann, P.

1980-01-01

An experimental investigation was made to determine the reasons for the low aerodynamic performance of a 13.5 centimeter tip diameter aircraft engine starter turbine. The investigation consisted of an evaluation of both the stator and the stage. An approximate ten percent improvement in turbine efficiency was obtained when the honeycomb shroud over the rotor blade tips was filled to obtain a solid shroud surface.

Decreasing trends in number of depot medroxyprogesterone acetate starters in Norway - a cross-sectional study.

PubMed

Roksvaag, Ingvild; Skjeldestad, Finn E

2018-02-01

In this study, we examined changes in depot medroxyprogesterone acetate (DMPA) prescriptions over a time-period when new professions started prescribing, and when the method gained some negative media attention. The Norwegian Prescription Database provided data on hormonal contraception from 2006 through 2012. We estimated the annual number of DMPA users by calculating doses sold per day/1000 women and calculated, for each contraceptive method on annual basis, a proportion of defined daily doses of all hormonal contraceptives in five-year age groups at reproductive age. All analyses were done in SPSS, version 22, with Chi-square test, t-test, and survival analysis with p < 0.05 as significance level. There were minor differences in overall DMPA use during the study years. The take-out rate was equivalent to 11-12/1000 women aged 15-49 years. DMPA sales amounted to nearly 4% of all daily doses of hormonal contraceptives sold. General practitioners and physicians without a specialty were the major prescribers. The number of starters decreased by nearly 40% during the study years and was consistent across age groups. The average use duration among starters was 17.7 (95% CI 17.5-17.9) months (range 0-90). There were minor changes in the relative proportion of long-term users beyond 24 months during the study years. DMPA plays a minor role in the overall use of hormonal contraception in Norway, even among teenagers. The number of starters is decreasing, indicating a more restrictive attitude toward first use, especially among general practitioners. © 2017 Nordic Federation of Societies of Obstetrics and Gynecology.

Yogurt, living cultures, and gut health.

PubMed

Morelli, Lorenzo

2014-05-01

Bacteria used to ferment milk to obtain yogurt belong to thermophilic, bile-sensitive species of lactic acid bacteria, which are not ideally suited for survival into the human gut. However, assessing the viability of these bacteria through the digestive tract may be relevant to evaluate their potential to deliver some beneficial effects for the well-being of the consumer. The well-known reduction in the symptoms caused by lactose maldigestion is not the only benefit provided by yogurt starter cultures; some additional effects will be reviewed here, with special attention paid to data that may suggest a strain-dependent effect, features that are not present with lactose hydrolysis.

Contribution of natural milk culture to microbiota, safety and hygiene of raw milk cheese produced in alpine malga.

PubMed

Lucchini, Rosaria; Cardazzo, Barbara; Carraro, Lisa; Negrinotti, Michele; Balzan, Stefania; Novelli, Enrico; Fasolato, Luca; Fasoli, Franco; Farina, Giovanni

2018-03-31

Processing of alpine milk in malga farms is carried out under conditions that can favor contamination by coliforms, coagulase-positive staphylococci, or pathogens such as Listeria monocytogenes . With the aim to improve the hygienic characteristics and safety of cheese produced in four malga farms the use of lyophilized Natural Milk Culture prepared with selected strains was tested.. Two cheesemaking tests were carried out in the same day always starting from the same milk: in the first case following the malga recipe that uses either Natural Whey Culture or without the addition of a starter, in the second one using a Natural Milk Culture. Cheesemaking were carried out in four malga farms located in the west area of Trentino region within the same week. For hygienic and safety evaluation, aerobic colony count, coagulase-positive staphylococci, Escherichia coli , staphylococcal toxins, Listeria monocytogenes , and Salmonella spp, pH and a w were determined in raw milk from evening and morning milking, curd in vat, curd after extraction and two months-ripened cheese. Pathogens or toxins, high values of coagulase- positive staphylococci and E. coli were not found in cheese samples. However, in the curd coagulase-positive staphylococci reached values almost of 5 Log CFU/g in the two malga without starter cultures. The use of Natural Milk Culture reduced E. coli counts. In addition, DNA was extracted from cheese samples and from Natural Milk Culture and the composition of the microbial community determined by Next Generation Sequencing method. The determination of cheese microbial communities demonstrated that the use of Natural Milk Culture exerted different effects in the different malga , in any case preserving bacterial biodiversity.

Contribution of natural milk culture to microbiota, safety and hygiene of raw milk cheese produced in alpine malga

PubMed Central

Lucchini, Rosaria; Cardazzo, Barbara; Carraro, Lisa; Negrinotti, Michele; Balzan, Stefania; Novelli, Enrico; Fasolato, Luca; Fasoli, Franco; Farina, Giovanni

2018-01-01

Processing of alpine milk in malga farms is carried out under conditions that can favor contamination by coliforms, coagulase-positive staphylococci, or pathogens such as Listeria monocytogenes. With the aim to improve the hygienic characteristics and safety of cheese produced in four malga farms the use of lyophilized Natural Milk Culture prepared with selected strains was tested.. Two cheesemaking tests were carried out in the same day always starting from the same milk: in the first case following the malga recipe that uses either Natural Whey Culture or without the addition of a starter, in the second one using a Natural Milk Culture. Cheesemaking were carried out in four malga farms located in the west area of Trentino region within the same week. For hygienic and safety evaluation, aerobic colony count, coagulase-positive staphylococci, Escherichia coli, staphylococcal toxins, Listeria monocytogenes, and Salmonella spp, pH and awwere determined in raw milk from evening and morning milking, curd in vat, curd after extraction and two months-ripened cheese. Pathogens or toxins, high values of coagulase- positive staphylococci and E. coli were not found in cheese samples. However, in the curd coagulase-positive staphylococci reached values almost of 5 Log CFU/g in the two malga without starter cultures. The use of Natural Milk Culture reduced E. coli counts. In addition, DNA was extracted from cheese samples and from Natural Milk Culture and the composition of the microbial community determined by Next Generation Sequencing method. The determination of cheese microbial communities demonstrated that the use of Natural Milk Culture exerted different effects in the different malga, in any case preserving bacterial biodiversity. PMID:29732331

Exploitation of the diverse insertion sequence element content of dairy Lactobacillus helveticus starters as a rapid method to identify different strains.

PubMed

Kaleta, Pawel; Callanan, Michael J; O'Callaghan, John; Fitzgerald, Gerald F; Beresford, Thomas P; Ross, R Paul

2009-10-01

The species Lactobacillus helveticus is a commonly used thermophilic starter and/or adjunct culture for Swiss and Cheddar cheese manufacture. Its use is normally associated with flavour improvement which is known to be associated with culture traits such as rapid autolysis and high proteolytic activity. The genome of the commercial strain, DPC4571, was recently sequenced and found to have an abundance of IS sequences in terms of both abundance (213 intact) and diversity (21 types). Given this unique diversity for a lactic acid bacterium, we investigated whether PCR-based IS fingerprinting could be used as a discriminatory tool to distinguish between different strains of Lb. helveticus. A set of ten primers targeting five of the most numerous groups (ISL1201, ISLhe65, ISLhe2, ISLhe15 and ISL2) of IS elements was designed. Multiplex-PCR with all primers resulted in 1-12 discreet amplicons for each strain tested. The resultant fingerprints (in the 0.5 kb-3 kb range) were found to be strain specific and reproducible. This approach thus provides a valuable method to distinguish between Lb. helveticus strains while giving some indication of the relative abundance of IS sequences in each strain.

Improving the Quality of Lab Reports by Using Them as Lab Instructions

ERIC Educational Resources Information Center

Haagen-Schuetzenhoefer, Claudia

2012-01-01

Lab exercises are quite popular in teaching science. Teachers have numerous goals in mind when teaching science laboratories. Nevertheless, empirical research draws a heterogeneous picture of the benefits of lab work. Research has shown that it does not necessarily contribute to the enhancement of practical abilities or content knowledge. Lab…

Computational Labs Using VPython Complement Conventional Labs in Online and Regular Physics Classes

NASA Astrophysics Data System (ADS)

Bachlechner, Martina E.

2009-03-01

Fairmont State University has developed online physics classes for the high-school teaching certificate based on the text book Matter and Interaction by Chabay and Sherwood. This lead to using computational VPython labs also in the traditional class room setting to complement conventional labs. The computational modeling process has proven to provide an excellent basis for the subsequent conventional lab and allows for a concrete experience of the difference between behavior according to a model and realistic behavior. Observations in the regular class room setting feed back into the development of the online classes.