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Sample records for starter lactic acid

  1. DRY COMPOSITION OF STARTER CULTURES FORM LACTIC ACID MICROORGANISMS

    At. Kraevska

    2014-03-01

    Full Text Available The purpose of this work is to investigate the possibility of producing of lyophilized lactic acid starter Lb. plantarum strain 226/1, designed for a starter culture in the production of pickles. The results of our studies demonstrate achievement of this goal by the specified process parameters.

  2. Effect of lactic acid bacteria starter culture fermentation of cassava ...

    The effects of lactic acid fermentation of cassava on the chemical and sensory characteristic of fufu flour were investigated. Two strains of Lactobacillus plantarum were used as starter cultures for the fermentation of cassava to fufu for 96 h. The resultant wet fufu samples were dried at 65oC in a cabinet dryer for 48 h and ...

  3. Physicochemical Characteristic of Fermented Goat Milk Added with Different Starters Lactic Acid Bacteria

    Anif Mukaromah Wati; Mei Jen Lin; Lilik Eka Radiati

    2018-01-01

    Development of traditional food including dadih to be commercial fermented milk was needed to achieve efficiency and effective of products. Dadih with natural starter needs to be changed with starters because starters can be produced commercially. This study aims to evaluate physicochemical characteristic of fermented goat milk that added with different starters Lactic Acid Bacteria (LAB) isolated from dadih. The materials used for this research were starters LAB that isolated from dadih. In ...

  4. Physicochemical Characteristic of Fermented Goat Milk Added with Different Starters Lactic Acid Bacteria

    Anif Mukaromah Wati

    2018-03-01

    Full Text Available Development of traditional food including dadih to be commercial fermented milk was needed to achieve efficiency and effective of products. Dadih with natural starter needs to be changed with starters because starters can be produced commercially. This study aims to evaluate physicochemical characteristic of fermented goat milk that added with different starters Lactic Acid Bacteria (LAB isolated from dadih. The materials used for this research were starters LAB that isolated from dadih. In this experiment, treatments were used different starters that namely starter 11, starter 21, starter 25, starter 29, and starter 41 then analized about water content, ash content, fat content, syneresis, and viscosity. The experiment was carried out with three replications. The data were analyzed by ANOVA using the basic design of Completely Randomized Design (CRD and continued by Duncan's Multiple Range Test (DMRT if there was a significantly different. The results showed that different starters had influence on water content, ash content, fat content, syneresis, and viscosity. It could be concluded that starters 11 and 41 were the best starter that can be applied in fermented goat milk product based on physical quality with lower syneresis and higher viscosity. But based on chemical quality, starter 11 was the best starter with lower water content and higher ash content.

  5. Antimicrobial Activity – The Most Important Property of Probiotic and Starter Lactic Acid Bacteria

    Blaženka Kos

    2010-01-01

    Full Text Available The antimicrobial activity of industrially important lactic acid bacteria as starter cultures and probiotic bacteria is the main subject of this review. This activity has been attributed to the production of metabolites such as organic acids (lactic and acetic acid, hydrogen peroxide, ethanol, diacetyl, acetaldehyde, acetoine, carbon dioxide, reuterin, reutericyclin and bacteriocins. The potential of using bacteriocins of lactic acid bacteria, primarily used as biopreservatives, represents a perspective, alternative antimicrobial strategy for continuously increasing problem with antibiotic resistance. Another strategy in resolving this problem is an application of probiotics for different gastrointestinal and urogenital infection therapies.

  6. Lactic Acid Bacterial Starter Culture with Antioxidant and γ-Aminobutyric Acid Biosynthetic Activities Isolated from Flatfish-Sikhae Fermentation.

    Won, Yeong Geol; Yu, Hyun-Hee; Chang, Young-Hyo; Hwang, Han-Joon

    2015-12-01

    The aim of this study is to select a lactic acid bacterial strain as a starter culture for flatfish-Sikhae fermentation and to evaluate its suitability for application in a food system. Four strains of lactic acid bacteria isolated from commercial flatfish-Sikhae were identified and selected as starter culture candidates through investigation of growth rates, salt tolerance, food safety, and functional properties such as antioxidative and antimicrobial activities. The fermentation properties of the starter candidates were also examined in food systems prepared with these strains (candidate batch) in comparison with a spontaneous fermentation process without starter culture (control batch) at 15°C. The results showed that the candidate YG331 batch had better fermentation properties such as viable cell count, pH, and acidity than the other experimental batches, including the control batch. The results are expressed according to selection criteria based on a preliminary sensory evaluation and physiochemical investigation. Also, only a small amount of histamine was detected with the candidate YG331 batch. The radical scavenging activity of the candidate batches was better compared with the control batch, and especially candidate YG331 batch showed the best radical scavenging activity. Also, we isolated another starter candidate (identified as Lactobacillus brevis PM03) with γ-aminobutyric acid (GABA)-producing activity from commercial flatfish-Sikhae products. The sensory scores of the candidate YG331 batch were better than those of the other experimental batches in terms of flavor, color, and overall acceptance. In this study, we established selection criteria for the lactic acid bacterial starter for the flatfish-Sikhae production and finally selected candidate YG331 as the most suitable starter.

  7. Interactions among lactic acid starter and probiotic bacteria used for fermented dairy products.

    Vinderola, C G; Mocchiutti, P; Reinheimer, J A

    2002-04-01

    Interactions among lactic acid starter and probiotic bacteria were investigated to establish adequate combinations of strains to manufacture probiotic dairy products. For this aim, a total of 48 strains of Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, Lactococcus lactis, Lactobacillus acidophilus, Lactobacillus casei, and Bifidobacterium spp. (eight of each) were used. The detection of bacterial interactions was carried out using the well-diffusion agar assay, and the interactions found were further characterized by growth kinetics. A variety of interactions was demonstrated. Lb. delbrueckii subsp. bulgaricus was found to be able to inhibit S. thermophilus strains. Among probiotic cultures, Lb. acidophilus was the sole species that was inhibited by the others (Lb. casei and Bifidobacterium). In general, probiotic bacteria proved to be more inhibitory towards lactic acid bacteria than vice versa since the latter did not exert any effect on the growth of the former, with some exceptions. The study of interactions by growth kinetics allowed the setting of four different kinds of behaviors between species of lactic acid starter and probiotic bacteria (stimulation, delay, complete inhibition of growth, and no effects among them). The possible interactions among the strains selected to manufacture a probiotic fermented dairy product should be taken into account when choosing the best combination/s to optimize their performance in the process and their survival in the products during cold storage.

  8. Role in Cheese Flavour Formation of Heterofermentative Lactic Acid Bacteria from Mesophilic Starter Cultures

    Pedersen, Thomas Bæk

    -starters including strains from our culture collection were used throughout the project. Initially selected strains were screened for enzyme activities involved in cheese flavour formation after growth in a cheese based medium (CBM) and in a nutrient rich growth medium (MRS). The Leuconostoc strains had low....... A cheese trial was performed with selected strains to investigate how the heterofermentative strains influenced the ripening in semi-hard cheese. The cheeses were made using a Lactococcus starter including citrate positive Lactoccus and with the addition of one strain of heterofermentative bacteria...... with plant isolates, the ability to ferment citrate and lacked several genes involved in the fermentation of complex carbohydrates. The presented research in this thesis has gained insight in to the role of heterofermentative lactic acid bacteria in cheese flavour formation. The traditional DL...

  9. The Organoleptic and Physic Characteristics and Lactic Acid Contents of Yoghurt with Commercial Starter Added Bifidobacteria bifidum

    Tatik Khusniati

    2012-10-01

    Full Text Available Bifidobacteria bifidum is probiotic bacteria which inhibit negative bacteria in human ulcer. Adding B. bifidum in commercial yoghurt starter, may increase yoghurt quality. To know yoghurt quality, organoleptic and physic characteristics and lactic acidcontents of yoghurt with commercial starter added B. bifidum was observed. B. bifidum concentrations added were 1:4, 2:4, 3:4 (v/v. Organoleptic characteristics were conducted by 18 panelists, physics were visually detected and lactic acid contents were by titration method. The results show that accepted yoghurt characteristics were yoghurt with commercial starter added B. bifidum 1:4 (v/v, and fat yoghurt were more acceptable than that skim. The higher B. bifidum concentrations used, the stronger flavours (after expiry date and colours (at and after expiry date of yoghurt, while yoghurt homogenity decreased (at and after expiry date. Fat yoghurt flavours were stronger than that of skim. The higher B. bifidum concentrations and storage times, the higher yoghurt lactic acid contents. Lactic acid contents of fat yoghurt with various starters, were higher than that skim at storage 0-15 days. The fat yoghurt lactic acid contents were 0.99%-1.44%, while that skim were 0.95-1.20%. Based on organoleptic and physic characteristics and lactic acid contents, fat yoghurt were more acceptable that that skim.

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

    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.

  11. Characteristic of cow milk dadih using starter of probiotic of lactic acid bacteria

    Sri Usmiati

    2011-06-01

    Full Text Available Dadih is an original dairy product from West Sumatera processed traditionally. It is a spontaneous fermentation of buffalo milk at room temperature for 48 hours in a bamboo tube, has no standard of processing and quality. Dadih is potentially to be develop into probiotic products (functional food that can be enjoyed by the public widely. Development of cow's milk dadih is necessary since buffalo milk is available only in certain area. Product and characteristic information of cow milk dadih using probiotic of lactic acid bacteria starter has not been known. The research objective was to determine the characteristics of cow milk dadih that used starter of probiotic lactic acid bacteria during storage at room temperature (27oC and cold temperature (4oC. The study was designed using a factorial randomized block design pattern 12x3 at room temperature and 12X4 at cold temperatures, with the number of repeatation of 3 times. Treatment consisted of: (i starter formula (A using a single bacterium or a combination of Lactobacillus acidophilus, Lactobacillus casei and Bifidobacterium longum, and (ii storage time (B. Observed parameters included pH value, titrable acidity, the total plate count, and in-vitro probiotic testing (bacterial resistance to bile salts and low pH of cow milk dadih. The results showed that L. acidophilus early exponential phase was at the hour 3rd, L. casei at the hour 4th and B. longum on the 3rd of which is used as the optimum time of mixing two or more bacteria in the manufacture of cow milk dadih. The volume of starter used was 3% with time fermentation of 48 hours at room temperature (27-30oC. Cow milk dadih that was stored for 7 days at room temperature (27-30oC and for 21 days at cold temperatures (4-10oC was able to maintain viability of bacteria to bile salts and low pH at 1010-1012 cfu/ml with percentage resistance varied. The cow milk dadih using a combination starter of B. longum with other probiotics on the

  12. Modelling the influence of metabolite diffusion on non-starter lactic acid bacteria growth in ripening Cheddar cheese

    Czárán, Tamás; Rattray, Fergal P.; Møller, Cleide O.de A.

    2018-01-01

    The influence of metabolite diffusion within the cheese matrix on growth of non-starter lactic acid bacteria (NSLAB) during Cheddar cheese ripening was mathematically modelled. The model was calibrated at a realistic range of diffusion of metabolites and the decay and growth parameters...

  13. BIOCHEMICAL CHARACTERISTICS OF LACTIC ACID PRODUCING BACTERIA AND PREPARATION OF CAMEL MILK CHEESE BY USING STARTER CULTURE

    T. Ahmed and R. Kanwal

    2004-04-01

    Full Text Available Lactic acid bacteria (LAB were isolated from camel milk by culturing the milk on specific media and pure culture was obtained by sub-culturing. Purification of culture was confirmed by Gram’s staining and identified by different biochemical tests. Camel milk contained lactic acid producing bacteria like Streptococci such as S. cremoris and S. lactis and Lactobacilli such as L. acidophilus. L. acidophilus grew more rapidly in camel milk than others as its growth was supported by camel milk. Ability of each strain was tested to convert lactose of milk into lactic acid. It was observed that 66% lactose was converted by S. lactis 20, whereas S. cremoris 22 and L. acidophilus 23 converted 56 and 74% lactose into lactic acid, respectively. Effect of freeze-drying was also recorded and the results showed that in all cases there was a slight decrease in the cell count before and after the freeze-drying. The decrease was approximately 0.47, 0.078 and 0.86% for S. lactis 20, S. cremoris 22 and L. acidophilus 23, respectively. Starter culture was prepared from strains isolated from camel milk. Camel and buffalo milk cheese was prepared by using starter culture. The strains isolated from camel milk were best for acid production and coagulated the milk in less time. It is concluded that cheese can be prepared successfully from camel milk and better results can be obtained by coagulating milk with starter culture.

  14. The Use of Lactic Acid Bacteria Starter Culture in the Production of Nunu, a Spontaneously Fermented Milk Product in Ghana

    Fortune Akabanda

    2014-01-01

    Full Text Available Nunu, a spontaneously fermented yoghurt-like product, is produced and consumed in parts of West Africa. A total of 373 predominant lactic acid bacteria (LAB previously isolated and identified from Nunu product were assessed in vitro for their technological properties (acidification, exopolysaccharides production, lipolysis, proteolysis and antimicrobial activities. Following the determination of technological properties, Lactobacillus fermentum 22-16, Lactobacillus plantarum 8-2, Lactobacillus helveticus 22-7, and Leuconostoc mesenteroides 14-11 were used as single and combined starter cultures for Nunu fermentation. Starter culture fermented Nunu samples were assessed for amino acids profile and rate of acidification and were subsequently evaluated for consumer acceptability. For acidification properties, 82%, 59%, 34%, and 20% of strains belonging to Lactobacillus helveticus, L. plantarum, L. fermentum, and Leu. mesenteriodes, respectively, demonstrated fast acidification properties. High proteolytic activity (>100 to 150 μg/mL was observed for 50% Leu. mesenteroides, 40% L. fermentum, 41% L. helveticus, 27% L. plantarum, and 10% Ent. faecium species. In starter culture fermented Nunu samples, all amino acids determined were detected in Nunu fermented with single starters of L. plantarum and L. helveticus and combined starter of L. fermntum and L. helveticus. Consumer sensory analysis showed varying degrees of acceptability for Nunu fermented with the different starter cultures.

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

    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.

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

    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.

  17. Production of freeze-dried lactic acid bacteria starter culture for cassava fermentation into gari

    Yao, AA

    2009-10-01

    Full Text Available Sixteen lactic acid bacteria, eight Lactobacillus plantarum, three L. pentosus, two Weissella paramesenteroides, two L. fermemtum and one Leuconostoc mesenteroides ssp. mesenteroides were previously isolated from cassava fermentation and selected...

  18. Influence of starter culture of lactic acid bacteria on the shelf life of ...

    A total of eight lactic acid bacteria were isolated from various fermented cereal gruels (ogi). They were identified as Lactobacillus plantarum, Lactobacillus casei, Leuconostoc mesenteroides, Lactobacillus brevis, Lactobacillus fermentum, Lactobacillus delbrueckii, Lactobacillus acidophilus and Pediococcus acidilactici.

  19. Method of quantifying the loss of acidification activity of lactic acid starters during freezing and frozen storage.

    Fonseca, F; Béal, C; Corrieu, G

    2000-02-01

    We have developed a method to quantify the resistance to freezing and frozen storage of lactic acid starters, based on measuring the time necessary to reach the maximum acidification rate in milk (tm) using the Cinac system. Depending on the operating conditions, tm increased during the freezing step and storage. The loss of acidification activity during freezing was quantified by the difference (delta tm) between the tm values of the concentrated cell suspension before and after freezing. During storage at -20 degrees C, linear relationships between tm and the storage time were established. Their slope, k, allowed the quantitation of the decrease in acidification activity during 9-14 weeks of frozen storage. The method was applied to determine the resistance to freezing and frozen storage of four strains of lactic acid bacteria and to quantify the cryoprotective effect of glycerol.

  20. Characterization of non-starter lactic acid bacteria in traditionally produced home-made Radan cheese during ripening

    Jokovic Natasa

    2011-01-01

    Full Text Available Two hundred thirteen non-starter lactic acid bacteria isolated from Radan cheese during ripening were identified with both a classical biochemical test and rep-PCR with (GTG5 primer. For most isolates, which belong to the Lactococcus lactis subsp. lactis, Leuconostoc mesenteroides, Lactobacillus plantarum, Lactobacillus paraplantarum and Enterococcus faecium, a phenotypic identification was in good agreement with rep-PCR identification. Lactococeus lactis subsp. lactis, Enterococcus faecium and subspecies from the Lenconostoc mesenteroides group were the dominant population of lactic acid bacteria in cheese until 10 days of ripening and only one Streptococcus thermophilus strain was isolated from the 5-day-old cheese sample. As ripening progressed, Lactobacillus plantarum became the predominant species together with the group of heterofermentative species of lactobacilli that could not be precisely identified with rep-PCR.

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

    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

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

    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.

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

    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

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

    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

    A total of 375 lactic acid bacteria were isolated from fermenting cassava in South Africa, Benin, Kenya and Germany, and were characterised by phenotypic and genotypic tests. These could be divided into five main groups comprising strains of facultatively heterofermentative rods, obligately heterofermentative rods, heterofermentative cocci, homofermentative cocci and obligately homofermentative rods, in decreasing order of predominance. Most of the facultatively heterofermentative rods were identified by phenotypic tests as presumptive Lactobacillus plantarum-group strains, which also comprised the most predominant bacteria (54.4% of strains) isolated in the study. The next predominant group of lactic acid bacteria (14.1% of total isolates) consisted of obligately heterofermentative rods belonging either to the genus Lactobacillus or Weissella, followed by the heterofermentative cocci (13.9% of isolates) belonging to the genera Weissella or Leuconostoc. Homofermentative cocci were also isolated (13.3% of isolates). Biochemical properties such as production of alpha-amylase, beta-glucosidase, tannase, antimicrobials (presumptive bacteriocin and H(2)O(2)-production), acidification and fermentation of the indigestible sugars raffinose and stachyose, were evaluated in vitro for selection of potential starter strains. A total of 32 strains with one or more desirable biochemical properties were pre-selected and identified using rep-PCR fingerprinting in combination with 16S rRNA sequencing of representative rep-PCR cluster isolates. Of these strains, 18 were identified as L. plantarum, four as Lactobacillus pentosus, two each as Leuconostoc fallax, Weissella paramesenteroides and Lactobacillus fermentum, one each as Leuconostoc mesenteroides subsp. mesenteroides and Weissella cibaria, while two remained unidentified but could be assigned to the L. plantarum-group. These strains were further investigated for clonal relationships, using RAPD-PCR with three primers, and of

  5. Optimasi Konsentrasi Fruktooligosakarida untuk Meningkatkan Pertumbuhan Bakteri Asam Laktat Starter Yoghurt (CONCENTRATION OPTIMIZATION OF FRUCTOOLIGOSACCHARIDES TO INCREASE GROWTH OF LACTIC ACID BACTERIA YOGHURT STARTER

    Raden Haryo Bimo Setiarto

    2017-09-01

    Full Text Available Fructooligosaccharides are prebiotic source that widely used in food products, such as: fermented milk and infant formula. Prebiotics are food components that cannot be digested in the digestive tract enzymatically. However, they can be fermented by probiotic bacteria in the colon. This study aimed to determine the optimum concentrations of fructooligosaccharides in order to increase the growth of lactic acid bacteria yogurt starter (Lactobacillus acidophillus, Lactobacillus bulgaricus, Streptococcus thermophillus. Optimation concentration of fructooligosaccharides on the growth of Lactobacillus acidophilus, Lactobacillus bulgaricus, Streptococcus thermophillus can be determined based on OD (optical density, TPC (Total Plate Count, total lactic acid content and pH value. Suplementation of fructooligosaccharides 1 % (w/v on the media MRSB increased significantly the growth of L. acidophilus, L.bulgaricus, S. thermophilus. Furthermore, L. acidophilus, L. bulgaricus and S. thermophilus experienced exponential growth phase during incubation period from 6 to 18 hours. Fermentation of L. acidophilus, L. bulgaricus, S. thermophilus in MRSB medium supplemented by fructooligosaccharides decreased the pH value of the formation of organic acids from 6.00 to 4.00. ABSTRAK Fruktooligosakarida adalah sumber prebiotik yang banyak digunakan dalam produk pangan olahan seperti susu fermentasi dan susu formula. Prebiotik adalah komponen bahan pangan fungsional yang tidak dapat dicerna di dalam saluran pencernaan secara enzimatik sehingga akan difermentasi oleh bakteri probiotik dalam usus besar. Penelitian ini bertujuan menentukan konsentrasi optimum fruktooligosakarida untuk meningkatkan pertumbuhan bakteri asam laktat starter yoghurt (Lactobacillus acidophillus, Lactobacillus bulgaricus, Streptococcus thermophillus. Konsentrasi optimum fruktooligosakarida pada pertumbuhan Lactobacillus acidophilus, Lactobacillus bulgaricus, Streptococcus thermophillus dapat

  6. The role of lactic acid bacteria (Lactobacillus sp yel133) from beef in inhibiting of microbial contaminants on various fillers of starter culture

    Yunilas; Mirwandhono, E.

    2018-02-01

    The role of Lactic Acid Bacteria (LAB) on the starter culture can be seen from the ability to grow and suppress the growth of microbial contaminants (fungi). The research aimed to investigate the role of LAB (Lactobacillus sp YEL133) in inhibiting microbial contaminants (fungi) on starter cultures of various fillers. The materials used in this research was Lactobacillus sp YEL133 from beef and various fillers (rice flour, corn starch and wheat flour). The research methods used completely randomized design (CRD) with 3 treatments and 4 replications. The treatments of this research was P1(rice flour), P2 (corn starch) and P3 (wheat flour) that inoculated with Lactobacillus sp YEL133. Parameters which is observed such as: growth of lactic acid bacteria, total microbes and total fungi as microbial contaminants. The results showed that the starter culture with a filler material of rice flour produce lactic acid bacteria and microbes were highly significant (P wheat flour, as well as able to suppress the growth of microbial contaminants (fungi). The conclusion of the research is the use Lactobacillus sp YEL133 can suppress the growth of fungi on the starter culture using rice flour.

  7. Factors affecting capsule size and production by lactic acid bacteria used as dairy starter cultures.

    Hassan, A N; Frank, J F; Shalabi, S I

    2001-02-28

    The effects of sugar substrates on capsule size and production by some capsule-forming nonropy and ropy dairy starter cultures were studied. Test sugars (glucose, lactose, galactose, or sucrose) were used as a sole carbohydrate source and the presence of a capsule and its size were determined by using confocal scanning laser microscopy. Nonropy strains produced maximum capsule size when grown in milk. Strains that did not produce capsules in milk did not produce them in any other growth medium. Specific sugars required for capsule production were strain-dependent. Increasing lactose content of Elliker broth from 0.5 to 5% or adding whey protein or casein digest produced larger capsules. Whey protein concentrate stimulated production of larger capsules than did casamino acids or casitone. Some Streptococcus thermophilus strains produced capsules when grown on galactose only. Nonropy strains of Lactobacillus delbrueckii subsp. bulgaricus produced capsules on lactose, but not on glucose. A ropy strain of Lactobacillus delbrueckii subsp. bulgaricus produced a constant capsule size regardless of the growth medium. The ability of some strains of Streptococcus thermophilus to use galactose in capsule production could reduce browning of mozzarella cheese during baking by removing a source of reducing sugar. Media that do not support capsule production may improve cell harvesting.

  8. 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.

    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.

  9. 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 ▿

    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

  10. Application of impedance microbiology for evaluating potential acidifying performances of starter lactic acid bacteria to employ in milk transformation

    Elena Bancalari

    2016-10-01

    Full Text Available Impedance microbiology is a method that enables tracing microbial growth by measuring the change in the electrical conductivity. Different systems, able to perform this measurement, are available in commerce and are commonly used for food control analysis by mean of measuring a point of the impedance curve, defined time of detection. With this work we wanted to find an objective way to interpret the metabolic significance of impedance curves and propose it as a valid approach to evaluate the potential acidifying performances of starter lactic acid bacteria to be employed in milk transformation. To do this it was firstly investigated the possibility to use the Gompertz equation to describe the data coming from the impedance curve obtained by mean of BacTrac 4300®. Lag time (λ, maximum specific M% rate (µmax, and maximum value of M% (Yend have been calculated and, given the similarity of the impedance fitted curve to the bacterial growth curve, their meaning has been interpreted. Potential acidifying performances of eighty strains belonging to Lactobacillus helveticus, Lactobacillus delbrueckii subsp. bulgaricus, Lactococcus lactis and Streptococcus thermophilus species have been evaluated by using the kinetics parameters, obtained from Excel add-in DMFit version 2.1. The novelty and importance of our findings, obtained by means of BacTrac 4300®, is that they can also be applied to data obtained from other devices. Moreover, the meaning of λ, μmax and Yend that we have extrapolated from Modified Gompertz equation and discussed for lactic acid bacteria in milk, can be exploited also to other food environment or other bacteria, assuming that they can give a curve and that curve is properly fitted with Gompertz equation.

  11. Application of Impedance Microbiology for Evaluating Potential Acidifying Performances of Starter Lactic Acid Bacteria to Employ in Milk Transformation.

    Bancalari, Elena; Bernini, Valentina; Bottari, Benedetta; Neviani, Erasmo; Gatti, Monica

    2016-01-01

    Impedance microbiology is a method that enables tracing microbial growth by measuring the change in the electrical conductivity. Different systems, able to perform this measurement, are available in commerce and are commonly used for food control analysis by mean of measuring a point of the impedance curve, defined "time of detection." With this work we wanted to find an objective way to interpret the metabolic significance of impedance curves and propose it as a valid approach to evaluate the potential acidifying performances of starter lactic acid bacteria to be employed in milk transformation. To do this it was firstly investigated the possibility to use the Gompertz equation to describe the data coming from the impedance curve obtained by mean of BacTrac 4300®. Lag time (λ), maximum specific M% rate (μmax), and maximum value of M% (Yend) have been calculated and, given the similarity of the impedance fitted curve to the bacterial growth curve, their meaning has been interpreted. Potential acidifying performances of eighty strains belonging to Lactobacillus helveticus, Lactobacillus delbrueckii subsp. bulgaricus, Lactococcus lactis , and Streptococcus thermophilus species have been evaluated by using the kinetics parameters, obtained from Excel add-in DMFit version 2.1. The novelty and importance of our findings, obtained by means of BacTrac 4300®, is that they can also be applied to data obtained from other devices. Moreover, the meaning of λ, μmax, and Yend that we have extrapolated from Modified Gompertz equation and discussed for lactic acid bacteria in milk, can be exploited also to other food environment or other bacteria, assuming that they can give a curve and that curve is properly fitted with Gompertz equation.

  12. 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.

    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.

  13. Isolation and characterization of halophilic lactic acid bacteria acting as a starter culture for sauce fermentation of the red alga Nori (Porphyra yezoensis).

    Uchida, M; Miyoshi, T; Yoshida, G; Niwa, K; Mori, M; Wakabayashi, H

    2014-06-01

    A screening test was conducted for environmental samples to isolate halophilic lactic acid bacteria (HLAB) that can act as a starter in a Nori (Porphyra yezoensis)-sauce culture. After 9 months of incubation of enrichment cultures added with 25 kinds of environmental samples, growth of HLAB-like microorganisms was observed in six cultures salted at a 15% w/w level, including culture samples originally from mesopelagic water taken from 321 m-depth and from mountain snow taken at 2450 m-height. Ten strains were isolated and characterized as Tetragenococcus halophilus based on sequence analysis of the 16S rRNA gene. The isolates were inoculated into a newly prepared Nori-sauce culture and were confirmed to be able to act as a starter culture while three reference strains of T. halophilus obtained from a culture collection could not grow in the same culture. Halophilic lactic acid bacteria strains that can make growth in a highly salted Nori-sauce culture were isolated from environmental samples for the first time. All the isolates were identified as T. halophilus. The isolated strains are expected to be utilized as a starter culture for manufacturing fermented seaweed-sauce, which will be the first fermented food products obtained from algae. © 2014 The Society for Applied Microbiology.

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

    Kostinek, M

    2007-03-01

    Full Text Available A total of 375 lactic acid bacteria were isolated from fermenting cassava in South Africa, Benin, Kenya and Germany, and were characterised by phenotypic and genotypic tests. These could be divided into five main groups comprising strains...

  15. Taxonomic structure of the yeasts and lactic acid bacteria microbiota of pineapple (Ananas comosus L. Merr.) and use of autochthonous starters for minimally processing.

    Di Cagno, Raffaella; Cardinali, Gainluigi; Minervini, Giovanna; Antonielli, Livio; Rizzello, Carlo Giuseppe; Ricciuti, Patrizia; Gobbetti, Marco

    2010-05-01

    Pichia guilliermondii was the only identified yeast in pineapple fruits. Lactobacillus plantarum and Lactobacillus rossiae were the main identified species of lactic acid bacteria. Typing of lactic acid bacteria differentiated isolates depending on the layers. L. plantarum 1OR12 and L. rossiae 2MR10 were selected within the lactic acid bacteria isolates based on the kinetics of growth and acidification. Five technological options, including minimal processing, were considered for pineapple: heating at 72 degrees C for 15 s (HP); spontaneous fermentation without (FP) or followed by heating (FHP), and fermentation by selected autochthonous L. plantarum 1OR12 and L. rossiae 2MR10 without (SP) or preceded by heating (HSP). After 30 days of storage at 4 degrees C, HSP and SP had a number of lactic acid bacteria 1000 to 1,000,000 times higher than the other processed pineapples. The number of yeasts was the lowest in HSP and SP. The Community Level Catabolic Profiles of processed pineapples indirectly confirmed the capacity of autochthonous starters to dominate during fermentation. HSP and SP also showed the highest antioxidant activity and firmness, the better preservation of the natural colours and were preferred for odour and overall acceptability. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  16. Isolation of cultivable thermophilic lactic acid bacteria from cheeses made with mesophilic starter and molecular comparison with dairy-related Lactobacillus helveticus strains

    Jensen, Marie Elisabeth Penderup; Ardö, Ylva Margareta; Vogensen, Finn Kvist

    2009-01-01

    -related Lact. helveticus strains indicated that one isolate was a Lact. helveticus. Partial sequencing of 16S rRNA confirmed this, and the remaining four strains were identified as Lactobacillus delbrueckii, Lactobacillus fermentum and Enterococcus faecium. The rep-PCR profile of the isolated Lact. helveticus......Aims: To isolate cultivable thermophilic lactic acid bacteria from cheeses made with mesophilic starter and compare them with dairy-related Lactobacillus helveticus strains using molecular typing methods. Methods and Results: The number of thermophilic bacteria in seven commercial cheeses...

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

    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.

  18. Pro-technological and functional characterization of lactic acid bacteria to be used as starters for hemp (Cannabis sativa L.) sourdough fermentation and wheat bread fortification.

    Nionelli, Luana; Montemurro, Marco; Pontonio, Erica; Verni, Michela; Gobbetti, Marco; Rizzello, Carlo Giuseppe

    2018-08-20

    Lactic acid bacteria were isolated from hemp (Cannabis sativa L.) flour, spontaneously fermented dough, and type I sourdough. Isolates were identified and further selected based on pro-technological, nutritional and functional properties. Lactobacillus plantarum/s5, Pediococcus acidilactici/s5, and Leuconostoc mesenteroides/s1 were used as mixed starter to produce hemp sourdough. Significant decreases of the concentration of phytic acid, condensed tannins, and total saponins were observed during fermentation. The in vitro protein digestibility increased up to 90%. Experimental wheat breads were made adding 5% to 15% (w/w) hemp sourdough to the formula, characterized, and compared to baker's yeast wheat bread manufactured without hemp sourdough. The use of hemp sourdough improved the textural features of wheat bread, without adversely affect the sensory profile. Proportionally to the fortification with hemp sourdough, protein digestibility of the breads increased, while the predicted glycemic index significantly decreased (87 vs 100%). This work demonstrated that the fermentation with selected starters improved nutritional functionality of hemp flour, allowing its large-scale use in different food applications, meeting the consumers and producers request for novel fermented baked goods with a well-balanced nutritional profile. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Effect of dissolved oxygen on redox potential and milk acidification by lactic acid bacteria isolated from a DL-starter culture.

    Larsen, Nadja; Werner, Birgit Brøsted; Vogensen, Finn Kvist; Jespersen, Lene

    2015-03-01

    Milk acidification by DL-starter cultures [cultures containing Lactococcus lactis diacetylactis (D) and Leuconostoc (L) species] depends on the oxidation-reduction (redox) potential in milk; however, the mechanisms behind this effect are not completely clear. The objective of this study was to investigate the effect of dissolved oxygen on acidification kinetics and redox potential during milk fermentation by lactic acid bacteria (LAB). Fermentations were conducted by single strains isolated from mixed DL-starter culture, including Lactococcus lactis ssp. lactis, Lactococcus lactis ssp. cremoris, and Leuconostoc mesenteroides ssp. cremoris, by the DL-starter culture, and by the type strains. High and low levels of oxygen were produced by flushing milk with oxygen or nitrogen, respectively. The kinetics of milk acidification was characterized by the maximum rate and time of acidification (Vamax and Tamax), the maximum rate and time of reduction (Vrmax and Trmax), the minimum redox potential (Eh7 final), and time of reaching Eh7 final (Trfinal). Variations in kinetic parameters were observed at both the species and strain levels. Two of the Lc. lactis ssp. lactis strains were not able to lower redox potential to negative values. Kinetic parameters of the DL-starter culture were comparable with the best acidifying and reducing strains, indicating their additive effects. Acidification curves were mostly diauxic at all oxygen levels, displaying 2 maxima of acidification rate: before (aerobic maximum) and after (anaerobic maximum) oxygen depletion. The redox potential decreased concurrently with oxygen consumption and continued to decrease at slower rate until reaching the final values, indicating involvement of both oxygen and microbiological activity in the redox state of milk. Oxygen flushing had a negative effect on reduction and acidification capacity of tested LAB. Reduction was significantly delayed at high initial oxygen, exhibiting longer Trmax, Trfinal, or both

  20. PHAGE RESISTANT LACTIC ACID BACTERIAL MUTANTS

    2001-01-01

    Method of obtaining mutated lactic acid bacteria having a reduced susceptibility towards attack by bacteriophages, the method comprising mutating a gene involved in the pyrimidine metabolism, including pyrG encoding CTP synthetase. Such lactic acid bacteria are useful in starter cultures...

  1. Genetics of Lactic Acid Bacteria

    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).

  2. Study of physiological properties of some probiotics in multiple cultures with mesophilic lactic acid bacteria by Flora Danica Ch. Hansen commercial starter

    DANIELA PARASCHIV

    2011-12-01

    Full Text Available The aim of this study was to establish the growth ability and stability of probiotic strains Lactobacillus acidophilus (commercial code La-5®, Lactobacillus casei ssp. paracasei (commercial code L. casei 431® and Bifidobacterium bifidus (commercial code BB-12® in multiple cultures with mesophilic lactic bacteria, Lactococcus lactis ssp. cremoris, Lactococcus lactis ssp. lactis, Lactococcus lactis ssp. diacetylactis and Leuconostoc mesenteroides spp. cremoris, as Flora Danica Chr. Hansen commercial starters. Under the controlled fermentative conditions described below, a good starter combination, for the high rate of cells multiplication and for the good viability during storage, was identified in the mixture of L. casei 431®, BB-12® and Flora Danica, in ratio of 1:1:1 (9 log CFU/mL for each starter culture.

  3. Modelling the effect of lactic acid bacteria from starter- and aroma culture on growth of Listeria monocytogenes in cottage cheese

    Østergaard, Nina Bjerre; Eklöw, Annelie; Dalgaard, Paw

    2014-01-01

    bacteria fromadded starter culturewere on average predicted to grow16% faster than observed (Bf of 1.16 and Af of 1.32) and growth of the diacetyl producing aromaculturewas on average predicted 9% slower than observed (Bf of 0.91 and Af of 1.17). The acceptable simulation zone method showed the new models...

  4. Ten years of subproteome investigations in lactic acid bacteria: A key for food starter and probiotic typing

    Mangiapane, E.; Mazzoli, R.; Pessione, A.

    2015-01-01

    " strains that can be employed in food making and as nutraceutical supplements for human health. Unfortunately, these techniques are not used as extensively as it should be wise. The present report describes the most significant results obtained by our research group in 10 years of study on subproteomes...... elucidated by analysis of cytosolic, membrane-enriched, surface and extracellular proteomes. The present review opens a window on a yet largely underexplored field and highlights the huge potential of subproteome investigations for more rational choice of microbial strains as food starters, probiotics...

  5. Lactic acid test

    ... this page: //medlineplus.gov/ency/article/003507.htm Lactic acid test To use the sharing features on this page, please enable JavaScript. Lactic acid is mainly produced in muscle cells and red ...

  6. Identification of predominant lactic acid bacteria and yeasts of Turkish sourdoughs and selection of starter cultures for liquid sourdough production using different flours and dough yields

    Francesca, N.; Settanni, L.; Moschetti, G.

    2016-01-01

    Eight samples of mature sourdough were collected from five provinces of Turkey. Lactic acid bacteria and yeasts were isolated and identified and used in different combinations to produce liquid sourdoughs. Microbiological and physicochemical characteristics of the experimental sourdoughs made with different flour types and dough yields were studied. The main lactic acid bacteria species identified were Lactobacillus (L.) sanfranciscensis, Pediococcus pentosaceus, L. plantarum, L. namurencis, ...

  7. Modeling Lactic Fermentation of Gowé Using Lactobacillus Starter Culture.

    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.

  8. Compatible solutes in lactic acid bacteria subjected to water stress

    Kets, E.P.W.

    1997-01-01

    The goal of the research project described in this thesis was to investigate the protective effect of compatible solutes on tactic acid bacteria subjected to drying. Dried preparations of lactic acid bacteria are applied as starter cultures in feed and food industries. Dried starter

  9. Proteolytic enzymes of lactic acid bacteria

    Law, J; Haandrikman, A

    The proteolytic system of lactic acid bacteria is essential for their growth in milk and contributes significantly to flavour development in fermented milk products where these microorganisms are used as starter cultures. The proteolytic system is composed of proteinases which initially cleave the

  10. Flow cytometric assessment of viability of lactic acid bacteria

    Bunthof, C.J.; Bloemen, K.; Breeuwer, P.; Rombouts, F.M.; Abee, T.

    2001-01-01

    The viability of lactic acid bacteria is crucial for their applications as dairy starters and as probiotics. We investigated the usefulness of flow cytometry (FCM) for viability assessment of lactic acid bacteria. The esterase substrate carboxyfluorescein diacetate (cFDA) and the dye exclusion DNA

  11. Changes in the protein fraction of Merluccius bilinearis muscle under lactic acid bacterial fermentation using a Lactobacillus Acidophilus starter culture (ESP

    Luis J. Elizondo

    2016-03-01

    Full Text Available The effect of lactic acid bacterial fermentation on the protein fraction of Merluccius bilinearis muscle was evaluated. The non-protein fraction increased progressively with corresponding decreases in the percentage protein (dry weight indicating proteolytic activity during fermentation. Significant increases in the percentages of the amino acids cystine, isoleucine, phenylalanine and tyrosine were observed after two months of fermentation. Percentages of arginine decreased significantly after one week and again after two months of fermentation.

  12. Changes in the protein fraction of Merluccius bilinearis muscle under lactic acid bacterial fermentation using a Lactobacillus Acidophilus starter culture (ESP)

    Elizondo, Luis J.

    2016-01-01

    The effect of lactic acid bacterial fermentation on the protein fraction of Merluccius bilinearis muscle was evaluated. The non-protein fraction increased progressively with corresponding decreases in the percentage protein (dry weight) indicating proteolytic activity during fermentation. Significant increases in the percentages of the amino acids cystine, isoleucine, phenylalanine and tyrosine were observed after two months of fermentation. Percentages of arginine decreased significantly aft...

  13. Identification of Predominant Lactic Acid Bacteria and Yeasts of Turkish Sourdoughs and Selection of Starter Cultures for Liquid Sourdough Production Using Different Flours and Dough Yields

    Yağmur Gülten

    2016-06-01

    Full Text Available Eight samples of mature sourdough were collected from five provinces of Turkey. Lactic acid bacteria and yeasts were isolated and identified and used in different combinations to produce liquid sourdoughs. Microbiological and physicochemical characteristics of the experimental sourdoughs made with different flour types and dough yields were studied. The main lactic acid bacteria species identified were Lactobacillus (L. sanfranciscensis, Pediococcus pentosaceus, L. plantarum, L. namurencis, L. rossiae, Leuconostoc mesenteroides and L. zymae. L. spicheri, L. paralimentarius, L. mindensis, L. farciminis, L. acetotolerans, L. casei, Enterococcus faecium and Enterococcus durans were also found in sourdoughs at subdominant levels. Among yeasts, mainly Saccharomyces cerevisiae, but also Pichia guiliermondii and Torulaspora delbrueckii were the predominant species of yeasts identified in sourdoughs.

  14. Exploitation of vegetables and fruits through lactic acid fermentation.

    Di Cagno, Raffaella; Coda, Rossana; De Angelis, Maria; Gobbetti, Marco

    2013-02-01

    Lactic acid fermentation represents the easiest and the most suitable way for increasing the daily consumption of fresh-like vegetables and fruits. Literature data are accumulating, and this review aims at describing the main features of the lactic acid bacteria to be used for fermentation. Lactic acid bacteria are a small part of the autochthonous microbiota of vegetables and fruits. The diversity of the microbiota markedly depends on the intrinsic and extrinsic parameters of the plant matrix. Notwithstanding the reliable value of the spontaneous fermentation to stabilize and preserve raw vegetables and fruits, a number of factors are in favour of using selected starters. Two main options may be pursued for the controlled lactic acid fermentation of vegetables and fruits: the use of commercial/allochthonous and the use of autochthonous starters. Several evidences were described in favour of the use of selected autochthonous starters, which are tailored for the specific plant matrix. Pro-technological, sensory and nutritional criteria for selecting starters were reported as well as several functional properties, which were recently ascribed to autochthonous lactic acid bacteria. The main features of the protocols used for the manufacture of traditional, emerging and innovative fermented vegetables and fruits were reviewed. Tailored lactic acid bacteria starters completely exploit the potential of vegetables and fruits, which enhances the hygiene, sensory, nutritional and shelf life properties. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Modeling Lactic Fermentation of Gowé Using Lactobacillus Starter Culture

    Bettencourt de J. C. Munanga

    2016-12-01

    Full Text Available 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.

  16. Effect of dissolved oxygen on redox potential and milk acidification by lactic acid bacteria isolated from a DL-starter culture

    Larsen, Nadja; Werner, Birgit Brøsted; Vogensen, Finn Kvist

    2015-01-01

    potential to negative values. Kinetic parameters of the DL-starter culture were comparable with the best acidifying and reducing strains, indicating their additive effects. Acidification curves were mostly diauxic at all oxygen levels, displaying 2 maxima of acidification rate: before (aerobic maximum...... subspecies in DL-starter cultures. This knowledge is important for dairies to ensure optimized, fast, and controlled milk fermentations, leading to greater standardization of dairy products.......Milk acidification by DL-starter cultures [cultures containing Lactococcus lactis diacetylactis (D) and Leuconostoc (L) species] depends on the oxidation-reduction (redox) potential in milk; however, the mechanisms behind this effect are not completely clear. The objective of this study...

  17. Lactic acid and lactates

    Schreurs, V.V.A.M.

    2010-01-01

    This review aims to integrate the present state of knowledge on lactate metabolism in human and mammalian physiology as far as it could be subject to nutritional interventions. An integrated view on the nutritional, metabolic and physiological aspects of lactic acid and lactates might open a

  18. [Modeling of lactic acid fermentation of leguminous plant juices].

    Shurkhno, R A; Validov, Sh Z; Boronin, A M; Naumova, R P

    2006-01-01

    Lactic acid fermentation of leguminous plant juices was modeled to provide a comparative efficiency assessment of the previously selected strains of lactic acid bacteria as potential components of starter cultures. Juices of the legumes fodder galega, red clover, and alfalfa were subjected to lactic acid fermentation in 27 variants of experiment. Local strains (Lactobacillus sp. RS 2, Lactobacillus sp. RS 3, and Lactobacillus sp. RS 4) and the collection strain Lactobacillus plantarum BS 933 appeared the most efficient (with reference to the rate and degree of acidogenesis, ratio of lactic and acetic acids, and dynamics of microflora) in fermenting fodder galega juice; Lactobacillus sp. RS 1, Lactobacillus sp. RS 2, Lactobacillus sp. RS 3, Lactobacillus sp. RS 4, and L. plantarum BS 933 were the most efficient for red clover juice. Correction of alfalfa juice fermentation using the tested lactic acid bacterial strains appeared inefficient, which is explainable by its increased protein content and a low level of the acids produced during fermentation.

  19. Volatile Organic Compounds in Naturally Fermented Milk and Milk Fermented Using Yeasts, Lactic Acid Bacteria and Their Combinations As Starter Cultures

    Bennie C. Viljoen

    2007-01-01

    Full Text Available The volatile organic compounds present in 18 Zimbabwean naturally fermented milk (amasi samples and those produced by various yeasts, lactic acid bacteria (LAB and yeast/ LAB combinations were determined using headspace gas chromatography. The yeast strains used were: Candida kefyr 23, C. lipolytica 57, Saccharomyces cerevisiae 71, C. lusitaniae 68, C. tropicalis 78, C. lusitaniae 63, C. colliculosa 41, S. dairenensis 32, and Dekkera bruxellensis 43, and were coded Y1 to Y9, respectively. The LAB strains used were Lactococcus lactis subsp. lactis Lc39, L. lactis subsp. lactis Lc261, Lactobacillus paracasei Lb11, and L. lactis subsp. lactis biovar. diacetylactis C1, and were coded B1 to B4, respectively. Some of the volatile organic compounds found in amasi were acetaldehyde, ethanol, acetone, 2-methyl propanal, 2-methyl-1-propanol and 3-methyl-1-butanol. However, the levels of volatile organic compounds in the naturally fermented milk (NFM samples varied from one sample to another, with acetaldehyde ranging from 0.1–18.4 ppm, 3-methyl butanal from <0.1–0.47 ppm and ethanol from 39.3–656 ppm. The LAB/C. kefyr 23 (B/Y1 co-cultures produced significantly (p<0.05 higher levels of acetaldehyde and ethanol than the levels found in the NFM. The acetaldehyde levels in the B/Y1 samples ranged from 26.7–87.7 ppm, with L. lactis subsp. lactis biovar. diacetylactis C1 (B4 producing the highest level of acetaldehyde in combination with C. kefyr 23 (Y1. Using principal component analysis (PCA, most of the NFM samples were grouped together with single and co-cultures of Lc261, Lb11 and the non-lactose fermenting yeasts, mainly because of the low levels of ethanol and similar levels of 3-methyl butanal. Chromatograms of amasi showed prominent peak of methyl aldehydes and their alcohols including 3-methyl-butanal and 3-methyl-butanol, suggesting that these compounds are important attributes of Zimbabwean naturally fermented milk.

  20. Study of physiological properties of some probiotics in multiple cultures with mesophilic lactic acid bacteria by Flora Danica Ch. Hansen commercial starter

    DANIELA PARASCHIV; AIDA VASILE; MADALINA CONSTANTIN; ALEXANDRU CIOBANU; GABRIELA BAHRIM

    2011-01-01

    The aim of this study was to establish the growth ability and stability of probiotic strains Lactobacillus acidophilus (commercial code La-5®), Lactobacillus casei ssp. paracasei (commercial code L. casei 431®) and Bifidobacterium bifidus (commercial code BB-12®) in multiple cultures with mesophilic lactic bacteria, Lactococcus lactis ssp. cremoris, Lactococcus lactis ssp. lactis, Lactococcus lactis ssp. diacetylactis and Leuconostoc mesenteroides spp. cremoris, as Flora Danica Chr. Hansen co...

  1. Diversity and dynamic of lactic acid bacteria strains during aging of a long ripened hard cheese produced from raw milk and undefined natural starter.

    Pogačić, Tomislav; Mancini, Andrea; Santarelli, Marcela; Bottari, Benedetta; Lazzi, Camilla; Neviani, Erasmo; Gatti, Monica

    2013-12-01

    The aim of this study was to explore diversity and dynamic of indigenous LAB strains associated with a long ripened hard cheese produced from raw milk and undefined natural starter such as PDO Grana Padano cheese. Samples of milk, curd, natural whey culture and cheeses (2nd, 6th, 9th and 13th months of ripening) were collected from 6 cheese factories in northern Italy. DNA was extracted from each sample and from 194 LAB isolates. tRNA(Ala)-23S rDNA-RFLP was applied to identify isolates. Strain diversity was assessed by (GTG)5 rep-PCR and RAPD(P1)-PCR. Finally, culture-independent LH-PCR (V1-V2 16S-rDNA), was considered to explore structure and dynamic of the microbiota. Grana Padano LAB were represented mainly by Lactobacillus rhamnosus, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus delbrueckii, Lactobacillus helveticus and Pediococcus acidilactici, while the structure and dynamic of microbiota at different localities was specific. The strength of this work is to have focused the study on isolates coming from more than one cheese factories rather than a high number of isolates from one unique production. We provided a valuable insight into inter and intraspecies diversity of typical LAB strains during ripening of traditional PDO Grana Padano, contributing to the understanding of specific microbial ecosystem of this cheese. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Determination of lactic acid bacteria in Kaºar cheese and ...

    Lactic acid bacteria (LAB) arise in Kaşar cheese, an artisanal pasta filata cheese produced in Turkey from raw milk without starter addition or pasteurized milk with starter culture. In this study, 13 samples of Kaşar cheese that were produced from raw milk were used as reference materials. LAB were characterized by using ...

  3. Lactococcus bacteriophages isolated from whey and their effects on commercial lactic starters

    Maria Raquel de Godoy Oriani

    2004-08-01

    Full Text Available The incidence of phages of lactic acid bacteria in milk industry and their effects on acidification ability of commercial lactic acid starters were studied. Cheese whey samples (33 samples were collected from 17 factories. A total of 16 bacteriophages were isolated (12 specific for Lactococcus lactis, 3 for L. diacetylactis and one capable of lysing both species. The results showed that 10% reduction in acidification tests was not good indication of phage in the sample. The majority of samples showed reduction higher than 10%, although only 65% were phage positive. The isolated phages were quite stable and showed no reduction in infectivity even after 20 daily replications. A pool of bacteriophages was prepared from isolates and inoculated in 12 commercial lactic starters. After 8 hours of incubation, only 2 showed reduced acidification. Bacterial strains isolated from commercial starters were tested regarding the phage resistance. Considerable difference in phage sensitivity was observed among different starters (BD, D, O and L. diacetylactis. Five bacteriophages showed no infectivity on any isolates but one was infective for most of isolates.Para ampliar conhecimentos sobre a incidência de bacteriófagos de bactérias lácticas na indústria de leite do Estado de São Paulo e a sua influência sobre a capacidade acidificante de fermentos lácticos disponíveis em nosso mercado, o presente trabalho foi conduzido com o intuito de esclarecer a real situação dos laticínios no Estado. Foram coletadas 33 amostras de soro de queijo em 17 laticínios. Foram isolados 16 bacteriófagos, 12 específicos para Lactococcus lactis, 3 para L. diacetylactis e um capaz de lisar ambos os microrganismos. Os experimentos mostraram que, uma diminuição de 10% na acidez em presença de soro suspeito, ao contrário do estabelecido na literatura, não reflete a veracidade da presença de bacteriófagos na amostra, uma vez que a maioria apresentou redução acima

  4. Bioconversion Using Lactic Acid Bacteria: Ginsenosides, GABA, and Phenolic Compounds.

    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.

  5. [Teichoic acids from lactic acid bacteria].

    Livins'ka, O P; Harmasheva, I L; Kovalenko, N K

    2012-01-01

    The current view of the structural diversity of teichoic acids and their involvement in the biological activity of lactobacilli has been reviewed. The mechanisms of effects of probiotic lactic acid bacteria, in particular adhesive and immunostimulating functions have been described. The prospects of the use of structure data of teichoic acid in the assessment of intraspecific diversity of lactic acid bacteria have been also reflected.

  6. The impact of lactic acid bacteria on sourdough fermentation

    Savić Dragiša S.

    2005-01-01

    Full Text Available The baking of sourdough breads represents one of the oldest biotechnological processes. Despite traditionality, sourdough bread has great potential because of its benefits. Sourdough is a mixture of flour and water that is dominated by a complex microflora composed of yeasts and lactic acid bacteria that are crucial in the preparation of bread dough. Lactic acid bacteria cause acidification by producing lactic acid that increases the shelf life of bread by preventing the growth of undesirable microorganisms and affects the nutritional value of bread by increasing the availability of minerals. In addition to these advantages, the use of sourdough fermentation also improves dough machinability, breadcrumb structure and the characteristic flavour of bread. Lactic acid bacteria in sourdough fermentation are well known representing both homofermentative and heterofermentative bacteria. They may originate from selected natural contaminants in the flour or from a starter culture containing one or more known species of lactic acid bacteria. Sourdough can be cultivated in bakeries or obtained from commercial suppliers. However, many bakeries in Europe still use spontaneously fermented sourdoughs, which have been kept metabolically active for decades by the addition of flour and water at regular intervals. The impact of lactic acid bacteria on sourdough fermentation and their influence on dough and bread quality was discussed on the basis of research and literature data.

  7. Towards lactic acid bacteria-based biorefineries.

    Mazzoli, Roberto; Bosco, Francesca; Mizrahi, Itzhak; Bayer, Edward A; Pessione, Enrica

    2014-11-15

    Lactic acid bacteria (LAB) have long been used in industrial applications mainly as starters for food fermentation or as biocontrol agents or as probiotics. However, LAB possess several characteristics that render them among the most promising candidates for use in future biorefineries in converting plant-derived biomass-either from dedicated crops or from municipal/industrial solid wastes-into biofuels and high value-added products. Lactic acid, their main fermentation product, is an attractive building block extensively used by the chemical industry, owing to the potential for production of polylactides as biodegradable and biocompatible plastic alternative to polymers derived from petrochemicals. LA is but one of many high-value compounds which can be produced by LAB fermentation, which also include biofuels such as ethanol and butanol, biodegradable plastic polymers, exopolysaccharides, antimicrobial agents, health-promoting substances and nutraceuticals. Furthermore, several LAB strains have ascertained probiotic properties, and their biomass can be considered a high-value product. The present contribution aims to provide an extensive overview of the main industrial applications of LAB and future perspectives concerning their utilization in biorefineries. Strategies will be described in detail for developing LAB strains with broader substrate metabolic capacity for fermentation of cheaper biomass. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Electron transport chains of lactic acid bacteria

    Brooijmans, R.J.W.

    2008-01-01

    Lactic acid bacteria are generally considered facultative anaerobic obligate fermentative bacteria. They are unable to synthesize heme. Some lactic acid bacteria are unable to form menaquinone as well. Both these components are cofactors of respiratory (electron transport) chains of prokaryotic

  9. 21 CFR 184.1061 - Lactic acid.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Lactic acid. 184.1061 Section 184.1061 Food and... Substances Affirmed as GRAS § 184.1061 Lactic acid. (a) Lactic acid (C3H6O3, CAS Reg. Nos.: dl mixture, 598... hydrogen cyanide and subsequent hydrolysis to lactic acid. (b) The ingredient meets the specifications of...

  10. 21 CFR 582.1061 - Lactic acid.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Lactic acid. 582.1061 Section 582.1061 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1061 Lactic acid. (a) Product. Lactic acid. (b) Conditions of use. This substance is generally...

  11. Antimicrobial properties of lactic acid bacteria isolated from uruguayan artisan cheese

    Martín Fraga Cotelo

    2013-12-01

    Full Text Available Uruguayan artisan cheese is elaborated with raw milk and non-commercial starters. The associated native microbiota may include lactic acid bacteria and also potentially pathogenic bacteria. Lactic acid bacteria were isolated from artisan cheese, raw milk, and non-commercial starter cultures, and their potential bacteriocin production was assessed. A culture collection of 509 isolates was obtained, and five isolates were bacteriocin-producers and were identified as Enterococcus durans,Lactobacillus casei, and Lactococcus lactis. No evidence of potential virulence factors were found in E. durans strains. These are promising results in terms of using these native strains for cheese manufacture and to obtain safe products.

  12. Biodegradable poly(lactic acid)

    The fabrication of biodegradable poly(lactic acid) (PLA) microspheres containing total alkaloids of Caulis sinomenii was investigated. The formation, diameter, morphology and properties of the microspheres were characterized using Fourier transform infrared spectroscopy (FT–IR), laser particle size analyser and scanning ...

  13. Isolation and identification of indigenous lactic acid bacteria from North Sumatra river buffalo milk

    Heni Rizqiati; Cece Sumantr; Ronny Rachman Noor; E. Damayanthi; E. I. Rianti

    2015-01-01

    Buffalo milk is a source of various lactic acid bacteria (LAB) which is potential as culture starter as well as the probiotic. This study was conducted to isolate and identify LAB from indigenous North Sumatra river buffalo milk. Lactic acid bacteria was isolated and grown in medium De Man Rogosa Sharpe Agar (MRSA). The isolation was conducted to obtain pure isolate. The identification of LAB was studied in terms of morphology, physiology, biochemistry and survival on low pH. Morphology test...

  14. Process for the preparation of lactic acid and glyceric acid

    Jackson, James E [Haslett, MI; Miller, Dennis J [Okemos, MI; Marincean, Simona [Dewitt, MI

    2008-12-02

    Hexose and pentose monosaccharides are degraded to lactic acid and glyceric acid in an aqueous solution in the presence of an excess of a strongly anionic exchange resin, such as AMBERLITE IRN78 and AMBERLITE IRA400. The glyceric acid and lactic acid can be separated from the aqueous solution. Lactic acid and glyceric acid are staple articles of commerce.

  15. Stress Physiology of Lactic Acid Bacteria

    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

  16. 21 CFR 862.1450 - Lactic acid test system.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Lactic acid test system. 862.1450 Section 862.1450....1450 Lactic acid test system. (a) Identification. A lactic acid test system is a device intended to measure lactic acid in whole blood and plasma. Lactic acid measurements that evaluate the acid-base status...

  17. Antibiotic resistance of lactic acid bacteria

    Bulajić Snežana

    2008-01-01

    Full Text Available Knowledge on the antibiotic resistance of lactic acid bacteria is still limited, possibly because of the large numbers of genera and species encountered in this group, as well as variances in their resistance spectra. The EFSA considers antibiotic resistances, especially transferable resistances, an important decision criterion for determining a strain's QPS status. There are no approved standards for the phenotypic or genotypic evaluation of antibiotic resistances in food isolates. Also, the choice of media is problematic, as well as the specification of MIC breakpoint values as a result of the large species variation and the possible resulting variation in MIC values between species and genera. The current investigations in this field showed that we might end up with a range of different species- or genus-specific breakpoint values that may further increase the current complexity. Another problem associated with safety determinations of starter strains is that once a resistance phenotype and an associated resistance determinant have been identified, it becomes difficult to show that this determinant is not transferable, especially if the resistance gene is not located on a plasmid and no standard protocols for showing genetic transfer are available. Encountering those problems, the QPS system should allow leeway for the interpretations of results, especially when these relate to the methodology for resistance phenotype determinations, determinations of MIC breakpoints for certain genera, species, or strains, the nondeterminability of a genetic basis of a resistance phenotype and the transferability of resistance genes.

  18. Transconjugants of lactic acid bacteria

    2010-01-01

    The present invention relates to the field of dairy science. In particular, the present invention relates to methods for improving dairy starter culture quality as well as food products that can be obtained using such methods....

  19. Lactic acid bacteria: microbiological and functional aspects

    Lahtinen, Sampo

    2012-01-01

    "Updated with the substantial progress made in lactic acid and bacteria research since the third edition, this fourth volume discusses improved insights in genetics and new molecular biological techniques...

  20. Lignin poly(lactic acid) copolymers

    Olsson, Johan Vilhelm; Chung, Yi-Lin; Li, Russell Jingxian; Waymouth, Robert; Sattely, Elizabeth; Billington, Sarah; Frank, Curtis W.

    2017-02-14

    Provided herein are graft co-polymers of lignin and poly(lactic acid) (lignin-g-PLA copolymer), thermoset and thermoplastic polymers including them, methods of preparing these polymers, and articles of manufacture including such polymers.

  1. ISOLATION AND IDENTIFICATION OF LACTIC ACID PRODUCING BACTERIA FROM CAMEL MILK

    Toqeer Ahmad, Rashida Kanwal, Izhar Hussain Athar1, Najam Ayub

    2002-03-01

    Full Text Available Lactic acid bacteria (LAB were isolated from camel milk by culturing the camel milk on specific media and pure culture was obtained by sub culturing. Purification of culture was confirmed by Gram's staining and identified by different bio-chemical tests. Camel milk contains lactic acid producing bacteria including Strpptococci such as S. cremoris and S. lactis and Lactobacilli such as L. acidophilus L. acidophilus grows more rapidly in camel milk than others as its growth is supported by camel milk. A variety of food can be preserved by lactic acid fermentation, so starter culture was prepared from strains which were isolated from camel milk. Camel and buffalo's milk cheese was prepared by using starter culture. The strains isolated from camel milk were best for acid production and can coagulate the milk in less lime. Camel milk cheese was prepared and compared with buffalo's milk cheese. It is concluded that cheese can be prepared successfully from camel milk and better results can be obtained by coagulating milk with starter culture.

  2. Effects of selected lactic acid bacteria on the characteristics of amaranth sourdough.

    Jekle, Mario; Houben, Andreas; Mitzscherling, Martin; Becker, Thomas

    2010-10-01

    As the processing of amaranth in baked goods is challenging, the use of sourdough fermentation is a promising possibility to exploit the advantages of this raw material. In this study the fermentation properties of Lactobacillus plantarum, Lactobacillus paralimentarius and Lactobacillus helveticus in amaranth-based sourdough were examined in order to validate them as starter cultures. pH, total titratable acidity (TTA) and lactic/acetic acid ratio of the sourdough and sensory properties of the resulting wheat bread were evaluated using fermentation temperatures of 30 and 35 °C. While fermentation pH, TTA and lactic acid concentration showed small variations with the use of L. plantarum and L. paralimentarius, L. helveticus reached the most intensive acidification after initial adaptation to the substrate. Acetic acid production was independent of lactic acid metabolism. Furthermore, the lactic/acetic acid ratio exceeded recommendation by 10-35 times (fermentation quotient 25-82). Sensory evaluation showed no significant differences between the two fermentation temperatures but differences among the three micro-organisms. The results provide relevant information on the fermentation properties required of a customised starter for amaranth flour. Copyright © 2010 Society of Chemical Industry.

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

    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.

  4. Current taxonomy of phages infecting lactic acid bacteria

    Jennifer eMahony

    2014-01-01

    Full Text Available Phages infecting lactic acid bacteria have been the focus of significant research attention over the past three decades. Through the isolation and characterization of hundreds of phage isolates, it has been possible to classify phages of the dairy starter and adjunct bacteria Lactococus lactis, Streptococcus thermophilus, Leuconostoc spp. and Lactobacillus spp. Among these, phages of L. lactis have been most thoroughly scrutinized and serve as an excellent model system to address issues that arise when attempting taxonomic classification of phages infecting other LAB species. Here, we present an overview of the current taxonomy of phages infecting LAB genera of industrial significance, the methods employed in these taxonomic efforts and how these may be employed for the taxonomy of phages of currently underrepresented and emerging phage species.

  5. Phytase-active lactic acid bacteria from sourdoughs

    Nuobariene, Lina; Cizeikiene, Dalia; Gradzeviciute, Egle

    2015-01-01

    Whole-grain foods play an important role in human diet as they are relatively rich in minerals, however, the absorption of those minerals in human gut can be very low due to high content of the mineral binding phytate. Therefore, the object of this study was to identify phytase-active lactic acid...... bacteria (LAB) which could be used as a starter to increase mineral bioavailability in whole-meal bread. Hence, LAB isolates were isolated from Lithuanian sourdoughs, tested for phytase activity, and phytase active isolates were identified. Studies of phytase activity of the isolates were carried out...... at conditions optimal for leavening of bread dough (pH 5.5 and 30°C). The phytase active isolates belonged to the species Lactobacillus panis, Lactobacillus reuteri, Lactobacillus fermentum, and Pediococcus pentosaceus. Phytase activities of the tested LAB isolates were both extra- and intra...

  6. Lactic acid fermentation of crude sorghum extract

    Samuel, W.A.; Lee, Y.Y.; Anthony, W.B.

    1980-04-01

    Crude extract from sweet sorghum supplemented with vetch juice was utilized as the carbohydrate source for fermentative production of lactic acid. Fermentation of media containing 7% (w/v) total sugar was completed in 60-80 hours by Lactobacillus plantarum, product yield averaging 85%. Maximum acid production rates were dependent on pH, initial substrate distribution, and concentration, the rates varying from 2 to 5 g/liter per hour. Under limited medium supplementation the lactic acid yield was lowered to 67%. The fermented ammoniated product contained over eight times as much equivalent crude protein (N x 6.25) as the original medium. Unstructured kinetic models were developed for cell growth, lactic acid formation, and substrate consumption in batch fermentation. With the provision of experimentally determined kinetic parameters, the proposed models accurately described the fermentation process. 15 references.

  7. A Consistent Methodology Based Parameter Estimation for a Lactic Acid Bacteria Fermentation Model

    Spann, Robert; Roca, Christophe; Kold, David

    2017-01-01

    Lactic acid bacteria are used in many industrial applications, e.g. as starter cultures in the dairy industry or as probiotics, and research on their cell production is highly required. A first principles kinetic model was developed to describe and understand the biological, physical, and chemical...... mechanisms in a lactic acid bacteria fermentation. We present here a consistent approach for a methodology based parameter estimation for a lactic acid fermentation. In the beginning, just an initial knowledge based guess of parameters was available and an initial parameter estimation of the complete set...... of parameters was performed in order to get a good model fit to the data. However, not all parameters are identifiable with the given data set and model structure. Sensitivity, identifiability, and uncertainty analysis were completed and a relevant identifiable subset of parameters was determined for a new...

  8. Amino acids transport in lactic streptococci

    Driessen, Arnold Jacob Mathieu

    1987-01-01

    Lactic streptococci are extremely fastidious bacteria. For growth an exogenous source of amino acids and other nutrients is essential. The amino acid requirement in milk is fulfilled by the milk-protein casein, which is degraded by sequential hydrolysis, involving proteases and peptidases. ... Zie:

  9. Influence of microflora on texture and contents of amino acids, organic acids, and volatiles in semi-hard cheese made with DL-starter and propionibacteria

    Rehn, Lina Ulrika Ingeborg; Vogensen, Finn Kvist; Persson, S.-E.

    2011-01-01

    The microflora of semi-hard cheese made with DL-starter and propionic acid bacteria (PAB) is quite complex, and we investigated the influence of its variation on texture and contents of organic acids, free amino acids, and volatile compounds. Variation in the microflora within the normal range...... of log 8 to log 9 cfu/g, which was about 1 log unit higher than the total number of starter bacteria and about 2 log units higher than the number of nonstarter lactic acid bacteria. Eye formation was observed during the warm room period and further ripening (at 8 to 10°C). The amounts of acetate......, propionate, total content of free amino acids, 2-propanol, and ethyl propionate in the ripened cheeses were related to the number of PAB. A decrease in the relative content of Asp and Lys and increase of Phe over the ripening time were different from what is observed in semi-hard cheese without PAB...

  10. Comparative genomics of the lactic acid bacteria

    Makarova, K.; Slesarev, A.; Wolf, Y.; Sorokin, A.; Mirkin, B.; Koonin, E.; Pavlov, A.; Pavlova, N.; Karamychev, V.; Polouchine, N.; Shakhova, V.; Grigoriev, I.; Lou, Y.; Rokhsar, D.; Lucas, S.; Huang, K.; Goodstein, D. M.; Hawkins, T.; Plengvidhya, V.; Welker, D.; Hughes, J.; Goh, Y.; Benson, A.; Baldwin, K.; Lee, J. -H.; Diaz-Muniz, I.; Dosti, B.; Smeianov, V; Wechter, W.; Barabote, R.; Lorca, G.; Altermann, E.; Barrangou, R.; Ganesan, B.; Xie, Y.; Rawsthorne, H.; Tamir, D.; Parker, C.; Breidt, F.; Broadbent, J.; Hutkins, R.; O' Sullivan, D.; Steele, J.; Unlu, G.; Saier, M.; Klaenhammer, T.; Richardson, P.; Kozyavkin, S.; Weimer, B.; Mills, D.

    2006-06-01

    Lactic acid-producing bacteria are associated with various plant and animal niches and play a key role in the production of fermented foods and beverages. We report nine genome sequences representing the phylogenetic and functional diversity of these bacteria. The small genomes of lactic acid bacteria encode a broad repertoire of transporters for efficient carbon and nitrogen acquisition from the nutritionally rich environments they inhabit and reflect a limited range of biosynthetic capabilities that indicate both prototrophic and auxotrophic strains. Phylogenetic analyses, comparison of gene content across the group, and reconstruction of ancestral gene sets indicate a combination of extensive gene loss and key gene acquisitions via horizontal gene transfer during the coevolution of lactic acid bacteria with their habitats.

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

    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.

  12. Biotechnological Production of Lactic Acid and Its Recent Applications

    Young-Jung Wee

    2006-01-01

    Full Text Available Lactic acid is widely used in the food, cosmetic, pharmaceutical, and chemical industries and has received increased attention for use as a monomer for the production of biodegradable poly(lactic acid. It can be produced by either biotechnological fermentation or chemical synthesis, but the former route has received considerable interest recently, due to environmental concerns and the limited nature of petrochemical feedstocks. There have been various attempts to produce lactic acid efficiently from inexpensive raw materials. We present a review of lactic acid-producing microorganisms, raw materials for lactic acid production, fermentation approaches for lactic acid production, and various applications of lactic acid, with a particular focus on recent investigations. In addition, the future potentials and economic impacts of lactic acid are discussed.

  13. Novel Method of Lactic Acid Production by Electrodialysis Fermentation

    Hongo, Motoyoshi; Nomura, Yoshiyuki; Iwahara, Masayoshi

    1986-01-01

    In lactic acid fermentation by Lactobacillus delbrueckii, the produced lactic acid affected the lactic acid productivity. Therefore, for the purpose of alleviating this inhibitory effect, an electrodialysis fermentation method which can continuously remove produced lactic acid from the fermentation broth was applied to this fermentation process. As a result, the continuation of fermentation activity was obtained, and the productivity was three times higher than in non-pH-controlled fermentati...

  14. Lactic acid fermentation from refectory waste: Factorial design analysis

    Yomi

    2012-04-12

    Apr 12, 2012 ... method. At the end of the fermentation process, lactic acid exists in the complex medium of fermentation broth that contains whey proteins, biomass, salts and other impurities. Lactic acid is then recovered from this complex medium. Since the high cost of lactic acid purification process limits the utilization of ...

  15. Characterization of lactic acid bacteria isolated from Algerian arid ...

    Diversity and density of lactic acid bacteria isolated from Algerian raw goats\\' milk in arid zones were studied by determination of morphological, cultural, physiological and biochemical characteristics. 206 lactic acid bacterial strains were isolated, with 115 of them belonging to lactic acid cocci and others to the genus, ...

  16. Reactive extraction of lactic acid using alamine

    Wasewar, Kailas L.; Heesink, Albertus B.M.; Versteeg, Geert; Pangarkar, Vishwas G.

    2002-01-01

    Lactic acid is an important commercial product and extracting it out of aqueous solution is a growing requirement in fermentation based industries and recovery from waste streams. The design of an amine extraction process requires (i) equilibrium and (ii) kinetic data for the acid–amine (solvent)

  17. Multidrug transporters in lactic acid bacteria

    Mazurkiewicz, P; Sakamoto, K; Poelarends, GJ; Konings, WN

    Gram-positive lactic acid bacteria possess several Multi-Drug Resistance systems (MDRs) that excrete out of the cell a wide variety of mainly cationic lipophilic cytotoxic compounds as well as many clinically relevant antibiotics. These MDRs are either proton/drug antiporters belonging to the major

  18. The proteolytic systems of lactic acid bacteria

    Kunji, Edmund R.S.; Mierau, Igor; Hagting, Anja; Poolman, Bert; Konings, Wil N.

    1996-01-01

    Proteolysis in dairy lactic acid bacteria has been studied in great detail by genetic, biochemical and ultrastructural methods. From these studies the picture emerges that the proteolytic systems of lactococci and lactobacilli are remarkably similar in their components and mode of action. The

  19. Exopolysaccharides produced by lactic acid bacteria

    Caggianiello, Graziano; Kleerebezem, Michiel; Spano, Giuseppe

    2016-01-01

    A wide range of lactic acid bacteria (LAB) is able to produce capsular or extracellular polysaccharides, with various chemical compositions and properties. Polysaccharides produced by LAB alter the rheological properties of the matrix in which they are dispersed, leading to typically viscous and

  20. Characterization and ageing study of poly(lactic acid) films plasticized with oligomeric lactic acid

    Burgos, Nuria; Martino, Verónica P.; Jiménez, Alfonso

    2013-01-01

    Poly(lactic acid) (PLA) was melt-blended with a bio-based oligomeric lactic acid (OLA) plasticizer at different concentrations between 15 wt% and 25 wt% in order to enhance PLA ductility and to get a fully biodegradable material with potential application in films manufacturing. OLA was an efficient plasticizer for PLA, as it caused a significant decrease on glass transition temperature (Tg) while improving considerably ductile properties. Only one Tg value was observed in all cases and no ap...

  1. A method for the determination of D(-)-lactic acid

    Hamer, C.J.A. van den; Elias, R.W.

    A method for the determination of D(—)-lactic acid is described. An acetone powder from Escherichia coli B in the presence of methylene blue oxidizes D(—)-lactic specifically. Oxygen consumption in a Warburg apparatus was used as a measure of the D(—)-lactic acid.

  2. Lactic acid production from xylose by Geobacillus stearothermophilus strain 15

    Kunasundari, B.; Naresh, S.; Chu, J. E.

    2017-09-01

    Lactic acid is an important compound with a wide range of industrial applications. The present study tested the efficiency of xylose, as a sole carbon source to be converted to lactic acid by Geobacillus stearothermophilus strain 15. To the best of our knowledge, limited information is available on the directed fermentation of xylose to lactic acid by this bacterium. The effects of different parameters such as temperature, pH, incubation time, agitation speed, concentrations of nitrogen and carbon sources on the lactic acid production were investigated statistically. It was found that the bacterium exhibited poor assimilation of xylose to lactic acid. Temperature, agitation rate and incubation time were determined to improve the lactic acid production slightly. The highest lactic acid yield obtained was 8.9% at 45°C, 300 RPM, 96 h, pH of 6.0 with carbon and nitrogen source concentrations were fixed at 5% w/v.

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

    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.

  4. Use of X-ray and gamma-induced mutants of lactic acid bacteria in the manufacture of dairy products

    Dilanian, Z; Makarian, K; Chuprina, D [Erevan Zootechnical and Veterinary Inst. (USSR). Chair of Dairying

    1976-04-01

    With the aid of X-ray and gamma irradiation were got mutants of lactic acid bacteria, which steadily retain acquired properties. Use of proteolytically active mutant strains in the production of armianski and sovetski cheeses shortened the time of their ripening and increased their quality. Gamma-mutant strain L. lactis 1621/I-M with high phenolstability was received and antibiotic activity with respect to some representatives of pathogenic microflora of the bowels. Use of this mutant in starters for sour milk products will raise their therapeutic effect against intestinal diseases. Deep morphological changes are taking place in lactic acid bacteria under the influence of ionizing radiation.

  5. Use of X-ray and gamma-induced mutants of lactic acid bacteria in the manufacture of dairy products

    Dilanian, Z.; Makarian, K.; Chuprina, D.

    1976-01-01

    With the aid of X-ray and gamma irradiation were got mutants of lactic acid bacteria, which steadily retain acquired properties. Use of proteolytically active mutant strains in the production of armianski and sovetski cheeses shortened the time of their ripening and increased their quality. Gamma-mutant strain L. lactis 1621/I-M with high phenolstability was received and antibiotic activity with respect to some representatives of pathogenic microflora of the bowels. Use of this mutant in starters for sour milk products will raise their therapeutic effect against intestinal diseases. Deep morphological changes are taking place in lactic acid bacteria under the influence of ionizing radiation. (orig.) [de

  6. Stochastic modelling of Listeria monocytogenes single cell growth in cottage cheese with mesophilic lactic acid bacteria from aroma producing cultures

    Østergaard, Nina Bjerre; Christiansen, Lasse Engbo; Dalgaard, Paw

    2015-01-01

    . 2014. Modelling the effect of lactic acid bacteria from starter- and aroma culture on growth of Listeria monocytogenes in cottage cheese. International Journal of Food Microbiology. 188, 15-25]. Growth of L. monocytogenes single cells, using lag time distributions corresponding to three different......A stochastic model was developed for simultaneous growth of low numbers of Listeria monocytogenes and populations of lactic acid bacteria from the aroma producing cultures applied in cottage cheese. During more than two years, different batches of cottage cheese with aroma culture were analysed...

  7. Characterisation of lactic acid bacteria in spontaneously fermented camel milk and selection of strains for fermentation of camel milk

    Fugl, Angelina June Brandt; Berhe, Tesfemariam; Kiran, Anil

    2017-01-01

    The microbial communities in spontaneously fermented camel milk from Ethiopia were characterised through metagenomic 16S rRNA sequencing and lactic acid bacteria were isolated with the goal of selecting strains suitable as starter cultures. The fermented camel milk microbiota was dominated either...... by Lactobacillales or by Enterobacteriaceae, depending on incubation temperature and the provider of the milk. Strains of species with a potential use as starter cultures i.e., Lactococcus lactis, Lactobacillus plantarum, and Pediococcus acidilactici, were isolated. Fast acidifiers of camel milk have been isolated...

  8. The expression of propionicin PLG-1 gene (plg-1) by lactic starters.

    Mohamed, Sameh E; Tahoun, Mahmoud K

    2015-05-01

    Propionicin PLG-1 is a bacteriocin produced by Propionibacterium thoenii P127. Such bacteriocin inhibits wide range of food-borne pathogens such as pathogenic Escherichia coli, Pseudomonas aeruginosa, Vibrio parahaemolyticus, Yersinia enterocolitica and a strain of Corynebacterium sp. In the present study, plg-1 gene expressing propionicin PLG-1 was isolated, sequenced for the first time and the resulting sequence was analysed using several web-based bioinformatics programs. The PCR product containing plg-1 gene was transferred to different lactic acid bacterial (LAB) strains using pLEB590 as a cloning vector to give the modified vector pLEBPLG-1. LAB transformants showed an antimicrobial activity against Esch. coli DH5α (most affected strain), Listeria monocytogenes 18116, and Salmonella enterica 25566 as model pathogenic strains. Such LAB transformants can be used in dairy industry to control the food-borne pathogens that are largely distributed worldwide and to feed schoolchildren in the poor countries where dangerous epidemic diseases and diarrhoea prevail.

  9. Effect of lactic acid bacteria starter culture fermentation of cassava ...

    SERVER

    2007-08-20

    Aug 20, 2007 ... of cassava on chemical and sensory characteristics of fufu flour ... cassava fufu flour has the highest protein content; this shows the influence of fermentation in .... 24, 48, 72, and 96 h, during the natural fermentation of cassava ...

  10. Poly(Lactic Acid) Based Flexible Films

    Fathilah binti Ali; Jamarosliza Jamaluddin; Arun Kumar Upadhyay

    2014-01-01

    Poly(lactic acid) (PLA) is a biodegradable polymer which has good mechanical properties, however, its brittleness limits its usage especially in packaging materials. Therefore, in this work, PLA based polyurethane films were prepared by synthesizing with different types of isocyanates; methylene diisocyanate (MDI) and hexamethylene diisocyanates (HDI). For this purpose, PLA based polyurethane must have good strength and flexibility. Therefore, polycaprolactone which has b...

  11. Ultrasonic Monitoring of the Progress of Lactic Acid Fermentation

    Masuzawa, Nobuyoshi; Kimura, Akihiro; Ohdaira, Etsuzo

    2003-05-01

    Promotion of lactic acid fermentation by ultrasonic irradiation has been attempted. It is possible to determine the progress of fermentation and production of a curd, i.e., yoghurt and or kefir, by measuring acidity using a pH meter. However, this method is inconvenient and indirect for the evaluation of the progress of lactic acid fermentation under anaerobic condition. In this study, an ultrasonic monitoring method for evaluating the progress of lactic acid fermentation was examined.

  12. Biopropionic acid production via molybdenumcatalyzed deoxygenation of lactic acid

    Korstanje, T.J.; Kleijn, H.; Jastrzebski, J.T.B.H.; Klein Gebbink, R.J.M.

    2013-01-01

    As the search for non-fossil based building blocks for the chemical industry increases, new methods for the deoxygenation of biomass-derived substrates are required. Here we present the deoxygenation of lactic acid to propionic acid, using a catalyst based on the non-noble and abundant metal

  13. LACTIC ACID BACTERIA FLORA OF KONYA KUFLU CHEESE: A TRADITIONAL CHEESE FROM KONYA PROVINCE IN TURKEY

    Ziba Guley

    2014-12-01

    Full Text Available The aim of this study was to characterize the lactic acid bacteria flora of mature Konya Kuflu cheese. Konya Kuflu cheese is a traditional blue cheese which is produced from raw milk without starter culture addition and mould growth occurs in uncontrolled conditions during its ripening. Lactic acid bacteria (LAB isolated from 9 mature Konya Kuflu cheese samples were investigated using a combination of conventional biochemical tests, API test kits, and molecular approaches. For some isolates, different results were obtained according to the identification technique. The overall LAB profile of Konya Kuflu cheese samples revealed that Lactobacillus brevis, Lactobacillus paracasei/Lactobacillus casei, Lactobacillus plantarum, Enterococcus faecium, and Enterococcus faecalis are the predominant species. In addition, 1 Pediococcus parvulus and 1 Enterococcus durans were also identified.

  14. Diversity and Stability of Lactic Acid Bacteria in Rye Sourdoughs of Four Bakeries with Different Propagation Parameters

    Viiard, Ene; Bessmeltseva, Marianna; Simm, Jaak; Talve, Tiina; Aasp?llu, Anu; Paalme, Toomas; Sarand, Inga

    2016-01-01

    We identified the lactic acid bacteria within rye sourdoughs and starters from four bakeries with different propagation parameters and tracked their dynamics for between 5-28 months after renewal. Evaluation of bacterial communities was performed using plating, denaturing gradient gel electrophoresis, and pyrosequencing of 16S rRNA gene amplicons. Lactobacillus amylovorus and Lactobacillus frumenti or Lactobacillus helveticus, Lactobacillus pontis and Lactobacillus panis prevailed in sourdoug...

  15. Technological and economic potential of poly(lactic acid) and lactic acid derivatives

    Datta, R.; Tsai, S.P.; Bonsignore, P.; Moon, S.H.; Frank, J.R.

    1993-10-01

    Lactic acid has been an intermediate-volume specialty chemical (world production {approximately}40,000 tons/yr) used in a wide range of food processing and industrial applications. lactic acid h,as the potential of becoming a very large volume, commodity-chemical intermediate produced from renewable carbohydrates for use as feedstocks for biodegradable polymers, oxygenated chemicals, plant growth regulators, environmentally friendly ``green`` solvents, and specially chemical intermediates. In the past, efficient and economical technologies for the recovery and purification of lactic acid from crude fermentation broths and the conversion of tactic acid to the chemical or polymer intermediates had been the key technology impediments and main process cost centers. The development and deployment of novel separations technologies, such as electrodialysis (ED) with bipolar membranes, extractive distillations integrated with fermentation, and chemical conversion, can enable low-cost production with continuous processes in large-scale operations. The use of bipolar ED can virtually eliminate the salt or gypsum waste produced in the current lactic acid processes. In this paper, the recent technical advances in tactic and polylactic acid processes are discussed. The economic potential and manufacturing cost estimates of several products and process options are presented. The technical accomplishments at Argonne National Laboratory (ANL) and the future directions of this program at ANL are discussed.

  16. Analyses of Dynamics in Dairy Products and Identification of Lactic Acid Bacteria Population by Molecular Methods

    Aytül Sofu

    2017-01-01

    Full Text Available Lactic acid bacteria (LAB with different ecological niches are widely seen in fermented meat, vegetables, dairy products and cereals as well as in fermented beverages. Lactic acid bacteria are the most important group of bacteria in dairy industry due to their probiotic characteristics and fermentation agents as starter culture. In the taxonomy of the lactic acid bacteria; by means of rep-PCR, which is the analysis of repetitive sequences that are based on 16S ribosomal RNA (rRNA gene sequence, it is possible to conduct structural microbial community analyses such as Restriction Fragment Length Polymorphism (RFLP analysis of DNA fragments of different sizes cut with enzymes, Random Amplified Polymorphic DNA (RAPD polymorphic DNA amplified randomly at low temperatures and Amplified Fragment-Length Polymorphism (AFLP-PCR of cut genomic DNA. Besides, in the recent years, non-culture-based molecular methods such as Pulse Field Gel Electrophoresis (PFGE, Denaturing Gradient Gel Electrophoresis (DGGE, Thermal Gradient Gel Electrophoresis (TGGE, and Fluorescence In-situ Hybridization (FISH have replaced classical methods once used for the identification of LAB. Identification of lactic acid bacteria culture independent regardless of the method will be one of the most important methods used in the future pyrosequencing as a Next Generation Sequencing (NGS techniques. This paper reviews molecular-method based studies conducted on the identification of LAB species in dairy products.

  17. TECHNOLOGICAL AND FUNCTIONAL PROPERTIES OF LACTIC ACID BACTERIA: THE IMPORTANCE OF THESE MICROORGANISMS FOR FOOD

    Amanda de Souza Motta

    2015-12-01

    Full Text Available Eacters of coccus or rods Gram-positive, catalase negative, non-sporulating, which produce lactic acid as the major end product during the fermentation of carbohydrates. When applied on food, provides beneficial effects to consumers through its functional and technological properties. With this the present review article, explore the potential application of lactic acid bacteria in food. The following genera are considered the principal lactic acid bacteria: Aerococcus, Carnobacterium, Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Oenococcus, Pediococcus, Streptococcus, Tetragenococcus, Vagococcus and Weissella. These cultures have been used as starter or adjunct cultures for the fermentation of foods and beverages due to their contributions to the sensorial characteristics of these products and by microbiological stability. Their probiotic properties have also been investigated. More recent studies by indigenous cultures have received increased attention in light of the search for isolated cultures of a given raw material and a certain region. These microorganisms are being investigated for its functional and technological potential that may be applied in product development with its own characteristics and designation of origin. Those properties will be discussed in the present review in order to highlight the performance of these bacteria and the high degree of control over the fermentation process and standardization of the final product. The use of autochthonous cultures will be considered due the increase of studies of new cultures of lactic acid bacteria isolated of milk and meat of distinct products.

  18. Prevention by lactic acid bacteria of the oxidation of human LDL.

    Terahara, M; Kurama, S; Takemoto, N

    2001-08-01

    Ether extracts of lactic acid bacteria were analyzed for prevention of the oxidation of erythrocyte membrane and human low-density lipoprotein in vivo. Streptococcus thermophilus 1131 and Lactobacillus delbrueckii subsp. bulgaricus 2038, yogurt starters, were chosen as test-strains, and ether extracts of these cultures were used as samples. Both strain 1131 and strain 2038 produced radical scavengers and inhibited oxidation of erythrocyte membranes and low-density lipoproteins. The antioxidative activity of strain 2038 was higher than that of strain 1131.

  19. Heme and menaquinone induced electron transport in lactic acid bacteria

    Brooijmans, Rob; Smit, Bart; Santos, Filipe; van Riel, Jan; de Vos, Willem M; Hugenholtz, Jeroen

    2009-01-01

    Abstract Background For some lactic acid bacteria higher biomass production as a result of aerobic respiration has been reported upon supplementation with heme and menaquinone. In this report, we have studied a large number of species among lactic acid bacteria for the existence of this trait. Results Heme- (and menaquinone) stimulated aerobic growth was observed for several species and genera of lactic acid bacteria. These include Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacill...

  20. Selection of lactic acid bacteria able to ferment inulin hydrolysates

    Octavian BASTON

    2012-12-01

    Full Text Available Eight homofermentative lactic acid bacteria isolates were tested for lactic acid production using chicory and Jerusalem artichoke hydrolysate as substrate. The pH, lactic acid yield and productivity were used to select the best homolactic bacteria for lactic acid production. The selected strains produced lactic acid at maximum yield after 24 hours of fermentation and the productivity was greater at 24 hours of fermentation. From all studied strains, Lb1 and Lb2 showed the best results regarding lactic acid yields andproductivity. After 48 hours of chicory and Jerusalem artichhoke hydrolysates fermentation, from all the studied strains, Lb2 produced the highest lactic acid yield (0.97%. Lb2 produced after 48 hours of fermentation the lowest pH value of 3.45±0.01. Lb2 showed greater lactic acid productivity compared to the other studied lactic acid bacteria, the highest values, 0.13 g·L-1·h-1fromJerusalem artichoke hydrolysate and 0.11g·L-1·h-1 from chicory hydrolysate, being produced after 24 hours of fermentation.

  1. Significant thermal energy reduction in lactic acid production process

    Mujtaba, Iqbal M.; Edreder, Elmahboub A.; Emtir, Mansour

    2012-01-01

    Lactic acid is widely used as a raw material for the production of biodegradable polymers and in food, chemical and pharmaceutical industries. The global market for lactic acid is expected to reach 259 thousand metric tons by the year 2012. For batch production of lactic acid, the traditional process includes the following steps: (i) esterification of impure lactic acid with methanol in a batch reactor to obtain methyl lactate (ester), (ii) separation of the ester in a batch distillation, (iii) hydrolysis of the ester with water in a batch reactor to produce lactic acid and (iv) separation of lactic acid (in high purity) in a batch distillation. Batch reactive distillation combines the benefit of both batch reactor and batch distillation and enhances conversion and productivity (Taylor and Krishna, 2000 ; Mujtaba and Macchietto, 1997 ). Therefore, the first and the last two steps of the lactic acid production process can be combined together in batch reactive distillation () processes. However, distillation (batch or continuous) is an energy intensive process and consumes large amount of thermal energy (via steam). This paper highlights how significant (over 50%) reduction in thermal energy consumption can be achieved for lactic acid production process by carefully controlling the reflux ratio but without compromising the product specification. In this paper, only the simultaneous hydrolysis of methyl lactate ester and the separation of lactic acid using batch reactive distillation is considered.

  2. The possibility of lactic acid fermentation in the triticale stillage

    MILICA MARKOVIĆ

    2011-06-01

    Full Text Available Triticale stillage is a by-product of bioethanol production. A research study was conducted in order to see if triticale stillage is adequate for lactic acid bacteria growth and lactic acid fermentation. Three Lactobacillus strains: Lactobacillus fermentum NRRL-B-75624, Lactobacillus fermentum PL-1, and Lactobacillus plantarum PL-4 were taken into consideration. Lactic acid fermentation was monitored by measuring pH value and titratable acidity. Lactobacillus fermentum PL-1 had the greatest decrease of pH values and increase of titratable acidity so it was chosen for future work. During the research, it was investigated how nutrient composition of triticale stillage and CaCO3 can influence lactic acid fermentation and CaCO3 role in cell protection. The nutrient composition of triticale stillage was satisfactory for lactic acid fermentation. The addition of CaCO3 helped in lactic acid fermentation. Although the titratable acidity in the samples with CaCO3 was lower than in the samples without CaCO3, the number of viable cells was higher for the samples with CaCO3, which showed that CaCO3 protected lactic acid cells from inhibition by lactic acid.

  3. Determination Amylolitic Characteristic of Predominant Lactic Acid Bacteria Isolated during Growol Fermentation, in a Different Starch Medium Composition

    Widya Dwi Rukmi Putri

    2018-04-01

    Full Text Available In order to achieve efficient lactic acid production from starch, fermentation of avarious composition starch medium by lactic acid bacteriawas examined in this study. Many strains of Lactobacillus plantarum isolated from growol fermentation, Lactobacillus plantarumsubsp. plantarum NBRC 15891 and Lactobacillus amylophyllus NBRC 15881 were used as starter cultures in starch basis medium, i.e, basal, basal-starch, enriched basal-starch with polypeptone and yeast extract. Lactobacillus plantarum UA3, AA2, AA11 showed the highest cells growth compare to both reference strains, but Lactobacillus amylophyllus NBRC 15881 showed a greater ability to degrade starch indicated by decreasing of pH and starch content of the fermented substrate. Enriched medium with peptone and yeast extract could generate the growth and starch degradation capabilities for all types of lactic acid bacteria were used.

  4. Beneficial effects of antioxidative lactic acid bacteria

    Hisako Nakagawa

    2017-01-01

    Full Text Available Oxidative stress is caused by exposure to reactive oxygen intermediates. The oxidative damage of cell components such as proteins, lipids, and nucleic acids one of the important factors associated with diabetes mellitus, cancers and cardiovascular diseases. This occurs as a result of imbalance between the generations of oxygen derived radicals and the organism’s antioxidant potential. The amount of oxidative damage increases as an organism ages and is postulated to be a major causal factor of senescence. To date, many studies have focused on food sources, nutrients, and components that exert antioxidant activity in worms, flies, mice, and humans. Probiotics, live microorganisms that when administered in adequate amounts provide many beneficial effects on the human health, have been attracting growing interest for their health-promoting effects, and have often been administered in fermented milk products. In particular, lactic acid bacteria (LAB are known to conferre physiologic benefits. Many studies have indicated the antioxidative activity of LAB. Here we review that the effects of lactic acid bacteria to respond to oxidative stress, is connected to oxidative-stress related disease and aging.

  5. [Regulating acid stress resistance of lactic acid bacteria--a review].

    Wu, Chongde; Huang, Jun; Zhou, Rongqing

    2014-07-04

    As cell factories, lactic acid bacteria are widely used in food, agriculture, pharmaceutical and other industries. Acid stress is one the important survival challenges encountered by lactic acid bacteria both in fermentation process and in the gastrointestinal tract. Recently, the development of systems biology and metabolic engineering brings unprecedented opportunity for further elucidating the acid tolerance mechanisms and improving the acid stress resistance of lactic acid bacteria. This review addresses physiological mechanisms of lactic acid bacteria during acid stress. Moreover, strategies to improve the acid stress resistance of lactic acid were proposed.

  6. Water and UV degradable lactic acid polymers

    Bonsignore, P.V.; Coleman, R.D.

    1996-10-08

    A water and UV light degradable copolymer is described made from monomers of lactic acid and a modifying monomer selected from the class consisting of ethylene glycol, propylene glycol, P-dioxanone, 1,5 dioxepan-2-one, 1,4-oxathialan-2-one, 1,4-dioxide and mixtures thereof. These copolymers are useful for waste disposal and agricultural purposes. Also disclosed is a water degradable blend of polylactic acid or modified polylactic acid and high molecular weight polyethylene oxide wherein the high molecular weight polyethylene oxide is present in the range of from about 2 by weight to about 50% by weight, suitable for films. A method of applying an active material selected from the class of seeds, seedlings, pesticides, herbicides, fertilizers and mixtures thereof to an agricultural site is also disclosed.

  7. Lactic acid Production with in situ Extraction in Membrane Bioreactor

    Hamidreza Ghafouri Taleghani

    2017-01-01

    Full Text Available Background and Objective: Lactic acid is widely used in the food, chemical and pharmaceutical industries. The major problems associated with lactic acid production are substrate and end-product inhibition, and by-product formation. Membrane technologyrepresents one of the most effective processes for lactic acid production. The aim of this work is to increase cell density and lactic acid productivity due to reduced inhibition effect of substrate and product in membrane bioreactor.Material and Methods: In this work, lactic acid was produced from lactose in membrane bioreactor. A laboratory scale membrane bioreactor was designed and fabricated. Five types of commercial membranes were tested at the same operating conditions (transmembrane pressure: 500 KPa and temperature: 25°C. The effects of initial lactose concentration and dilution rate on biomass growth, lactic acid production and substrate utilization were evaluated.Results and Conclusion: The high lactose retention of 79% v v-1 and low lactic acid retention of 22% v v-1 were obtained with NF1 membrane; therefore, this membrane was selected for membrane bioreactor. The maximal productivity of 17.1 g l-1 h-1 was obtainedwith the lactic acid concentration of 71.5 g l-1 at the dilution rate of 0.24 h−1. The maximum concentration of lactic acid was obtained at the dilution rate of 0.04 h−1. The inhibiting effect of lactic acid was not observed at high initial lactose concentration. The critical lactose concentration at which the cell growth severely hampered was 150 g l-1. This study proved that membrane bioreactor had great advantages such as elimination of substrate and product inhibition, high concentration of process substrate, high cell density,and high lactic acid productivity.Conflict of interest: There is no conflict of interest.

  8. Amino acid catabolism and generation of volatiles by lactic acid bacteria.

    Tavaria, F K; Dahl, S; Carballo, F J; Malcata, F X

    2002-10-01

    Twelve isolates of lactic acid bacteria, belonging to the Lactobacillus, Lactococcus, Leuconostoc, and Enterococcus genera, were previously isolated from 180-d-old Serra da Estrela cheese, a traditional Portuguese cheese manufactured from raw milk and coagulated with a plant rennet. These isolates were subsequently tested for their ability to catabolize free amino acids, when incubated independently with each amino acid in free form or with a mixture thereof. Attempts were made in both situations to correlate the rates of free amino acid uptake with the numbers of viable cells. When incubated individually, leucine, valine, glycine, aspartic acid, serine, threonine, lysine, glutamic acid, and alanine were degraded by all strains considered; arginine tended to build up, probably because of transamination of other amino acids. When incubated together, the degradation of free amino acids by each strain was dependent on pH (with an optimum pH around 6.0). The volatiles detected in ripened Serra da Estrela cheese originated mainly from leucine, phenylalanine, alanine, and valine, whereas in vitro they originated mainly from valine, phenylalanine, serine, leucine, alanine, and threonine. The wild strains tested offer a great potential for flavor generation, which might justify their inclusion in a tentative starter/nonstarter culture for that and similar cheeses.

  9. Catalytic acetoxylation of lactic acid to 2-acetoxypropionic acid, en route to acrylic acid

    Beerthuis, R.; Granollers, M.; Brown, D.R.; Salavagione, H.J.; Rothenberg, G.; Shiju, N.R.

    2015-01-01

    We present an alternative synthetic route to acrylic acid, starting from the platform chemical lactic acid and using heterogeneous catalysis. To improve selectivity, we designed an indirect dehydration reaction that proceeds via acetoxylation of lactic acid to 2-acetoxypropionic acid. This

  10. The effect of lactic acid bacteria on cocoa bean fermentation.

    Ho, Van Thi Thuy; Zhao, Jian; Fleet, Graham

    2015-07-16

    Cocoa beans (Theobroma cacao L.) are the raw material for chocolate production. Fermentation of cocoa pulp by microorganisms is crucial for developing chocolate flavor precursors. Yeasts conduct an alcoholic fermentation within the bean pulp that is essential for the production of good quality beans, giving typical chocolate characters. However, the roles of bacteria such as lactic acid bacteria and acetic acid bacteria in contributing to the quality of cocoa bean and chocolate are not fully understood. Using controlled laboratory fermentations, this study investigated the contribution of lactic acid bacteria to cocoa bean fermentation. Cocoa beans were fermented under conditions where the growth of lactic acid bacteria was restricted by the use of nisin and lysozyme. The resultant microbial ecology, chemistry and chocolate quality of beans from these fermentations were compared with those of indigenous (control) fermentations. The yeasts Hanseniaspora guilliermondii, Pichia kudriavzevii, Kluyveromyces marxianus and Saccharomyces cerevisiae, the lactic acid bacteria Lactobacillus plantarum, Lactobacillus pentosus and Lactobacillus fermentum and the acetic acid bacteria Acetobacter pasteurianus and Gluconobacter frateurii were the major species found in control fermentations. In fermentations with the presence of nisin and lysozyme, the same species of yeasts and acetic acid bacteria grew but the growth of lactic acid bacteria was prevented or restricted. These beans underwent characteristic alcoholic fermentation where the utilization of sugars and the production of ethanol, organic acids and volatile compounds in the bean pulp and nibs were similar for beans fermented in the presence of lactic acid bacteria. Lactic acid was produced during both fermentations but more so when lactic acid bacteria grew. Beans fermented in the presence or absence of lactic acid bacteria were fully fermented, had similar shell weights and gave acceptable chocolates with no differences

  11. Enzymatic synthesis of 11C-pyruvic acid and 11C-L-lactic acid

    Cohen, M.B.; Spolter, L.; Chang, C.C.; Cook, J.S.; Macdonald, N.S.

    1980-01-01

    L-Lactic acid is formed as the end product of glycolysis under anaerobic conditions in all cells, but this reaction is of special significance in the myocardium. L-Lactic acid is reversibly formed from and is in equilibrium with myocardial pyruvic acid, which is its sole metabolic pathway. 11 C-Pyruvic acid is synthesized from 11 C carbon dioxide using pyruvate-ferredoxin oxidoreductase and coenzymes. The 11 C-pyruvic acid is then converted to 11 -L-lactic acid by lactic acid dehydrogenase. The availability of 11 C-pyruvic acid and 11 C-L-lactic acid will permit the in vivo investigation of lactate metabolism. (author)

  12. Metabolism of Fructophilic Lactic Acid Bacteria Isolated from the Apis mellifera L. Bee Gut: Phenolic Acids as External Electron Acceptors

    Filannino, Pasquale; Addante, Rocco; Pontonio, Erica; Gobbetti, Marco

    2016-01-01

    ABSTRACT Fructophilic lactic acid bacteria (FLAB) are strongly associated with the gastrointestinal tracts (GITs) of Apis mellifera L. worker bees due to the consumption of fructose as a major carbohydrate. Seventy-seven presumptive lactic acid bacteria (LAB) were isolated from GITs of healthy A. mellifera L. adults, which were collected from 5 different geographical locations of the Apulia region of Italy. Almost all of the isolates showed fructophilic tendencies: these isolates were identified as Lactobacillus kunkeei (69%) or Fructobacillus fructosus (31%). A high-throughput phenotypic microarray targeting 190 carbon sources was used to determine that 83 compounds were differentially consumed. Phenotyping grouped the strains into two clusters, reflecting growth performance. The utilization of phenolic acids, such as p-coumaric, caffeic, syringic, or gallic acids, as electron acceptors was investigated in fructose-based medium. Almost all FLAB strains showed tolerance to high phenolic acid concentrations. p-Coumaric acid and caffeic acid were consumed by all FLAB strains through reductases or decarboxylases. Syringic and gallic acids were partially metabolized. The data collected suggest that FLAB require external electron acceptors to regenerate NADH. The use of phenolic acids as external electron acceptors by the 4 FLAB showing the highest phenolic acid reductase activity was investigated in glucose-based medium supplemented with p-coumaric acid. Metabolic responses observed through a phenotypic microarray suggested that FLAB may use p-coumaric acid as an external electron acceptor, enhancing glucose dissimilation but less efficiently than other external acceptors such as fructose or pyruvic acid. IMPORTANCE Fructophilic lactic acid bacteria (FLAB) remain to be fully explored. This study intends to link unique biochemical features of FLAB with their habitat. The quite unique FLAB phenome within the group lactic acid bacteria (LAB) may have practical relevance

  13. Lactic Acid Bacteria : embarking on 30 more years of research

    Kok, Jan; Johansen, Eric; Kleerebezem, Michiel; Teusink, Bas

    2014-01-01

    The 11th International Symposium on Lactic Acid Bacteria Lactic Acid Bacteria play important roles in the pro- duction of food and feed and are increasingly used as health-promoting probiotics. The incessant scientific interest in these microorganisms by academic research groups as well as by

  14. Heme and menaquinone induced electron transport in lactic acid bacteria

    Brooijmans, R.J.W.; Smit, B.; Santos, dos F.; Riel, van J.; Vos, de W.M.; Hugenholtz, J.

    2009-01-01

    ABSTRACT: BACKGROUND: For some lactic acid bacteria higher biomass production as a result of aerobic respiration has been reported upon supplementation with heme and menaquinone. In this report, we have studied a large number of species among lactic acid bacteria for the existence of this trait.

  15. 9th International Symposium on Lactic Acid Bacteria

    Kuipers, Oscar P.; Poolman, Berend; Hugenholtz, Jeroen

    What’s new in the field of lactic acid bacteria? The 9th International Symposium on Lactic Acid Bacteria (LAB9) will take place 31 August to 4 September 2008 in Egmond aan Zee, The Netherlands. Traditionally, the triannual LAB symposium focuses on the themes of genetics, physiology, and applications

  16. Characterization of lactic acid bacteria isolated from poultry farms in ...

    The Lactobacilli strains, both isolated from faeces, produced higher amounts of cells and lactic acid from soils as compared to the lactococci strain isolated from feathers. L (+)-lactic acid is the only optical isomer for use in pharmaceutical and food industries because is only adapted to assimilate this form. The optical isomers ...

  17. Capillary microreactors for lactic acid extraction: experimental and modelling study

    Susanti, Susanti; Winkelman, Jozef; Schuur, Boelo; Heeres, Hero; Yue, Jun

    2015-01-01

    Lactic acid is an important biobased chemical and, among others, is used for the production of poly-lactic acid. Down-stream processing using state of the art technology is energy intensive and leads to the formation of large amounts of salts. In this presentation, experimental and modeling studies

  18. Bacteriocins and lactic acid bacteria - a minireview | Savadogo ...

    Fermentation of various foods by lactic acid bacteria (LAB) is one of the oldest forms of biopreservation practised by mankind. Bacterial antagonism has been recognized for over a century but in recent years this phenomenon has received more scientific attention, particulary in the use of various strains of lactic acid bacteria.

  19. Screening and identification of lactic acid bacteria isolated from ...

    The lactic acid bacteria (LAB) isolated from sorghum (Sorghum bicolor. L.) silage were identified during different periods of evolution of sorghum silage in west Algeria. Morphological, physiological, biochemical and technological techniques were used to characterize lactic acid bacteria isolates. A total number of 27 ...

  20. Batch fermentative production of lactic acid from green- sugarcane juices

    Liliana Serna Cock

    2004-07-01

    Full Text Available Juice from the CC85-92 variety of green (unburned sugar cane was tested as a suitable substrate in lactic-acid production. Fermentations were carried out with a homo-fermentative strain isolated from crops of the same variety of cane. Both the centrifugation pre-treatment and concentrated-nitrogen effects on substrate conversion, lactic-acid concentration and yield were evaluated. After a fermentation time of 48 h at 32° C with 5% of yeast extract as nitrogen source, 40,78 g/L of lactic-acid concentration, 0.58 g/g of product yield and 33% of substrate conversion were obtained. Centrifugation did not affect lactic acid production. Key words: Lactic acid, green sugar cane, Lactococcus lactis subs. lactis.

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

    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.

  2. Lactic acid bacteria in Hamei and Marcha of North East India.

    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.

  3. Intensification of conversion of glucose to lactic acid : equilibria and kinetics for back extraction of lactic acid using trimethylamine

    Wasewar, Kailas L.; Heesink, A. Bert M.; Versteeg, Geert F.; Pangarkar, Vishwas G.

    2004-01-01

    Alamine 336 is an effective extractant for the recovery of lactic acid from aqueous solutions. An approach for regeneration and product recovery from such extracts is to back extract lactic acid with a water soluble, volatile tertiary amine such as trimethyl amine. Equilibrium data are presented

  4. Intensification of conversion of glucose to lactic acid: equilibria and kinetics for back extraction of lactic acid using trimethylamine

    Wasewar, Kailas L.; Heesink, Albertus B.M.; Versteeg, Geert; Pangarkar, Vishwas G.

    2004-01-01

    Alamine 336 is an effective extractant for the recovery of lactic acid from aqueous solutions. An approach for regeneration and product recovery from such extracts is to back extract lactic acid with a water soluble, volatile tertiary amine such as trimethyl amine. Equilibrium data are presented

  5. Mixed culture engineering for steering starter functionality

    Spuś, Maciej

    2016-01-01

    Undefined mixed complex starter cultures are broadly used in Gouda-type cheese production due to their robustness to phage predation, resilience for changes in environmental conditions and aroma compounds production ability during ripening. These microbial communities of lactic acid bacteria

  6. 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.

    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) (P0.05). Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Time related total lactic acid bacteria population diversity and ...

    user

    2011-02-07

    Feb 7, 2011 ... the diversity and dynamics of lactic acid bacteria (LAB) population in fresh ..... combining morphological, biochemical and molecular data are important for ..... acid bacteria from fermented maize (Kenkey) and their interactions.

  8. Evaluation of different lactic acid bacterial strains for probiotic characteristics

    B. Srinu,; T. Madhava Rao,; P. V. Mallikarjuna Reddy; K. Kondal Reddy

    2013-01-01

    Objective: The objective of the present study was to collect different Lactic acid bacterial strains from culture collection centers and screen their functional probiotic characteristics such as acid tolerance, bile tolerance, antibacterial activity and antibiotic sensitivity for their commercial use. Materials and Methods: Acid and bile tolerence of selected LAB(Lactic acid bacteria) was determined. The antibiotic resistance of Lactobacillus species was assessed using different antibiotic di...

  9. Microbial granulation for lactic acid production

    Kim, Dong-Hoon; Lee, Mo-Kwon; Hwang, Yuhoon

    2016-01-01

    This work investigated the formation of microbial granules to boost the productivity of lactic acid (LA). The flocculated form of LA-producing microbial consortium, dominated by Lactobacillus sp. (91.5% of total sequence), was initially obtained in a continuous stirred-tank reactor (CSTR), which...... increased, reaching 67 g L-fermenter−1h−1 at HRT 0.17 h. The size of LA-producing granules and hydrophobicity gradually increased with decrease in HRT, reaching 6.0 mm and 60%, respectively. These biogranules were also found to have high settling velocities and low porosities, ranging 2.69-4.73 cm s−1 and 0...

  10. Biotechnology of lactic acid bacteria: novel applications

    Mozzi, Fernanda; Raya, Raúl R; Vignolo, Graciela M

    2010-01-01

    ..., metabolism and biodiversity of LAB. Chapters contain state-of-the-art discussions of specific LAB applications such as their use as probiotics, live vaccines and starter cultures in old and new fermented products...

  11. DEVELOPMENT OF VEGETABLE PUREES AND DRINKS BY LACTIC ACID FERMENTATION

    At. Kraevska

    2014-03-01

    Full Text Available The object of this work was to investigate the possibility for development of vegetable purees and drinks by lactic acid fermentation. It was found that by the direct lactic acid fermentation of Lb.plantarum strain 226/1 the vitamin composition of vegetable purees is preserved and the biological value is increased. Drinks, prepared from fermented vegetable purees were remarkable with the pleasant lactic acid taste, the sucrose-acid composition was stable and balanced and they can be used both in the rational and in the dietary nutrition.

  12. Pengaruh Jenis Susu dan Persentase Starter yang Berbeda terhadap Kualitas Kefir

    Yusdar Zakaria

    2009-04-01

    Full Text Available Effect of different milk and starter percentage on kefir quality ABSTRACT. The objective of this study is to study the quality of kefir with different amount of starter added and different kind of milk. The quality of kefir was evaluated by measuring lactic acid level, syneresis, crude protein, crude fat and amount of active microorganism. The result showed that the different percentage of starter and kind of milk has a high significant on syneresis and Lactic Acid level (P < 0,01. The best interaction was resulted from the combination of 10% starter and UHT milk. The result also indicated that the different percentage of starter and kind of milk has no effect on crude protein, crude fat and the amount of active microorganism. The combination of 10% Starter and UHT milk, produces the best quality of kefir

  13. Genome sequences of two Leuconostoc pseudomesenteroides strains isolated from Danish dairy starter cultures

    Pedersen, Thomas Bæk; Kot, Witold Piotr; Hansen, L.H.

    2014-01-01

    The lactic acid bacterium Leuconostoc pseudomesenteroides can be found in mesophilic cheese starters, where it produces aromatic compounds from, e.g., citrate. Here, we present the draft genome sequences of two L. pseudomesenteroides strains isolated from traditional Danish cheese starters....

  14. L-Lactic Acid Production by Lactobacillus rhamnosus ATCC 10863

    Ana Lívia Chemeli Senedese

    2015-01-01

    Full Text Available Lactic acid has been shown to have the most promising application in biomaterials as poly(lactic acid. L. rhamnosus ATCC 10863 that produces L-lactic acid was used to perform the fermentation and molasses was used as substrate. A solution containing 27.6 g/L of sucrose (main composition of molasses and 3.0 g/L of yeast extract was prepared, considering the final volume of 3,571 mL (14.0% (v/v inoculum. Batch and fed batch fermentations were performed with temperature of 43.4°C and pH of 5.0. At the fed batch, three molasses feed were applied at 12, 24, and 36 hours. Samples were taken every two hours and the amounts of lactic acid, sucrose, glucose, and fructose were determined by HPLC. The sucrose was barely consumed at both processes; otherwise the glucose and fructose were almost entirely consumed. 16.5 g/L of lactic acid was produced at batch and 22.0 g/L at fed batch. Considering that lactic acid was produced due to the low concentration of the well consumed sugars, the final amount was considerable. The cell growth was checked and no substrate inhibition was observed. A sucrose molasses hydrolysis is suggested to better avail the molasses fermentation with this strain, surely increasing the L-lactic acid.

  15. Isolation and identification of indigenous lactic acid bacteria from North Sumatra river buffalo milk

    Heni Rizqiati

    2015-06-01

    Full Text Available Buffalo milk is a source of various lactic acid bacteria (LAB which is potential as culture starter as well as the probiotic. This study was conducted to isolate and identify LAB from indigenous North Sumatra river buffalo milk. Lactic acid bacteria was isolated and grown in medium De Man Rogosa Sharpe Agar (MRSA. The isolation was conducted to obtain pure isolate. The identification of LAB was studied in terms of morphology, physiology, biochemistry and survival on low pH. Morphology tests were conducted by Gram staining and cell forming; physiology tests were conducted for growing viability at pH 4.5 and temperature at 45oC; whereas biochemistry tests were conducted for CO2, dextran and NH3 productions. Determination of LAB species was conducted using Analytical Profile Index (API test CHL 50. Results of identification showed that 41 isolates were identified as LAB with Gram-positive, catalase-negative, rod and round shaped characteristics. Resistance test done to low pH (pH 2 for the lactic acid bacteria showed decrease of bacteria viability up to1.24±0.68 log cfu/ml. The resistant isolates at low pH were L12, L16, L17, L19, L20, M10, P8, S3, S19 and S20. Identification with API test CHL 50 for 10 isolates showed that four isolates were identified as Lactobacillus plantarum, L. brevis, L. pentosus and Lactococuslactis.

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

    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

  17. PENAMBAHAN BAKTERI ASAM LAKTAT TERENKAPSULASI UNTUK MENEKAN PERTUMBUHAN BAKTERI PATOGEN PADA PROSES PRODUKSI TAPIOKA [Addition of Encapsulated Lactic Acid Bacteria to Suppress the Growth of Pathogenic Bacteria during Tapioca Production

    Glisina Dwinoor Rembulan

    2015-07-01

    Full Text Available Lactic acid bacteria (LAB produce organic acids and active compounds which can inhibit the growth of pathogenic bacteria. Lactic acid bacteria potentially can be introduced to inhibit pathogenic bacteria in the tapioca production at the extraction stage, especially during the settling process since there is possibility of starch slurry to be contaminated by pathogenic bacteria from water. The objectives of this research were to design a solid starter of LAB through encapsulation by using modified starch includes sour cassava starch, lintnerized cassava starch and nanocrystalline starch, utilize the starter for suppressing the growth of pathogenic bacteria in the production process of tapioca and characterize the functional properties of tapioca. The encapsulation of lactic acid bacteria was conducted by freeze drying at a temperature of -50°C for 48 hours. The viability of LAB after freeze drying with sour cassava starch matrix was 92% of the liquid starter, with lintnerized cassava starch matrix was 93%, while that with nanocrystalline matrix was 96%. After application of the LAB culture during settling process for tapioca extraction and the tapioca was stored at room temperature for 6 months, it was shown that E. coli, Salmonella and Shigella were  detected in the native tapioca starch (without treatment while the starch added with lactic acid bacteria starter was not absent for the pathogenic bacteria. The addition of lactic acid bacteria in extraction process can suppress the growth of pathogenic bacteria in tapioca. The results showed that lintnerized cassava starch matrix is the best matrix because after 6 months it still contained lactic acid bacteria as compared to liquid starter and that encapsulated with other matrixes.

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

    Mahony, Jennifer; Ainsworth, Stuart; Stockdale, Stephen; Sinderen, Douwe van

    2012-01-01

    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, 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.

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

    Mahony, Jennifer, E-mail: j.mahony@ucc.ie [Department of Microbiology, University College Cork, Western Road, Cork (Ireland); Ainsworth, Stuart; Stockdale, Stephen [Department of Microbiology, University College Cork, Western Road, Cork (Ireland); Sinderen, Douwe van, E-mail: d.vansinderen@ucc.ie [Department of Microbiology, University College Cork, Western Road, Cork (Ireland); Alimentary Pharmabiotic Centre, Biosciences Institute, University College Cork, Western Road, Cork (Ireland)

    2012-12-20

    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, 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.

  20. Biodiversity and evolution of lactic acid bacteria in deferent periods ...

    f e c

    2013-04-03

    Apr 3, 2013 ... Key words: Lactic acid bacteria, identification, silage, sorghum, evolution, amylolytic, .... milk was checked which indicates the presence of LAB (Sengun et ..... pH, temperature and salinity cannot be used as reference.

  1. Production of lactic acid from Starchy-based food substrates

    SARAH

    2013-11-30

    Nov 30, 2013 ... are rather costly. This necessitated ... found application in many industries and various commercial ... and Sharpe (MRS) agar for total lactic acid bacteria ..... An Economic ... of Enzymes and Microbial Technology, 26: 87-. 107.

  2. Characterization And Identification Of Lactic Acid Bacteria From ...

    $hr3k

    2013-06-05

    , Pakistan. Accepted ... stands next to whole milk especially during summer. Dahi ... natural preservation. ... LAB is more varying and inconsistent as compared to ..... Interaction between probiotic lactic acid bacteria and canine.

  3. Mechanocatalytic Production of Lactic Acid from Glucose by Ball Milling

    Luyang Li

    2017-06-01

    Full Text Available A solvent-free process was developed for the direct production of lactic acid from glucose in a mechanocatalytic process in the presence of Ba(OH2, and a moderate lactic acid yield of 35.6% was obtained. Glucose conversion and lactic acid formation were favorable at higher catalyst/glucose mass ratios. However, at relatively lower catalyst/glucose mass ratios, they were greatly inhibited, and the promotion of fructose formation was observed. The mechanocatalytic process was applicable for various carbohydrates such as C5 sugars, C6 sugars, and disaccharides with 20–36% lactic acid yields achieved. This work provides a new pathway for the production of value-added chemicals from biomass resources.

  4. Antimicrobial activities of lactic acid bacteria isolated from akamu ...

    The partially purified inhibitory compounds were screened by agar spot assay method for antagonistic ... The partially purified compounds exhibited strong activity against ... Keywords: Bacteriocins, lactic acid bacteria (LAB), target organisms, ...

  5. original article antimicrobial susceptibility pattern of lactic acid

    User

    All the 57 tested lactic acid bacteria isolates were sensitive to Pencillin G (Pen, 10units), and ... resistance genes for Penicillin G and Erythromycin as indicated by the sensitivity of isolates. .... Antibiotic Susceptibility Test: The LAB isolates were ...

  6. Phenotypic and genotypic characterization of lactic acid bacteria ...

    ... of lactic acid bacteria isolated from Azerbaijani traditional dairy products. ... yogurts were produced from bovine's milk and the Ganja yogurt from buffalo's milk. ... It was determined using biochemical tests and molecular methods that four ...

  7. Antibacterial Activity of Lactic Acid Bacteria Isolated from Salad ...

    To determine the inhibitory capacity of lactic acid bacteria (LAB) due to the action of antagonistic substances, 8 members of the LAB group namely, Lactobacillus brevis, Lactobacillus casei, Lactobacillus cellebiosuis, Lactobacillus delbruesckii, Lactobacillus fermentum, Lactobacillus plantarum, Leuconostoc mesenteroides ...

  8. Characterization of lactic acid bacteria isolated from indigenous dahi ...

    Diversity and density of lactic acid bacteria from indigenous dahi were studied by the determination of morphological, cultural, physiological and biochemical characteristics. A total of 143 isolates were identified phenotypically and divided into three genera: Lactobacillus, Lactococcus and Streptococcus.

  9. Efficacy of Lactic Acid, Lactic Acid-Acetic Acid Blends, and Peracetic Acid To Reduce Salmonella on Chicken Parts under Simulated Commercial Processing Conditions.

    Ramirex-Hernandez, Alejandra; Brashears, Mindy M; Sanchez-Plata, Marcos X

    2018-01-01

    The poultry processing industry has been undergoing a series of changes as it modifies processing practices to comply with new performance standards for chicken parts and comminuted poultry products. The regulatory approach encourages the use of intervention strategies to prevent and control foodborne pathogens in poultry products and thus improve food safety and protect human health. The present studies were conducted to evaluate the efficacy of antimicrobial interventions for reducing Salmonella on inoculated chicken parts under simulated commercial processing conditions. Chicken pieces were inoculated by immersion in a five-strain Salmonella cocktail at 6 log CFU/mL and then treated with organic acids and oxidizing agents on a commercial rinsing conveyor belt. The efficacy of spraying with six different treatments (sterile water, lactic acid, acetic acid, buffered lactic acid, acetic acid in combination with lactic acid, and peracetic acid) at two concentrations was evaluated on skin-on and skin-off chicken thighs at three application temperatures. Skinless chicken breasts were used to evaluate the antimicrobial efficacy of lactic acid and peracetic acid. The color stability of treated and untreated chicken parts was assessed after the acid interventions. The lactic acid and buffered lactic acid treatments produced the greatest reductions in Salmonella counts. Significant differences between the control and water treatments were identified for 5.11% lactic acid and 5.85% buffered lactic acid in both skin-on and skin-off chicken thighs. No significant effect of treatment temperature for skin-on chicken thighs was found. Lactic acid and peracetic acid were effective agents for eluting Salmonella cells attached to chicken breasts.

  10. Antifungal Poly(lactic acid) Films Containing Thymol and Carvone

    Boonruang Kanchana; Chinsirikul Wannee; Hararak Bongkot; Kerddonfag Noppadon; Chonhenchob Vanee

    2016-01-01

    The goal of this study was to develop antifungal poly(lactic acid) films for food packaging applications. The antifungal compounds, thymol and R-(-)-carvone were incorporated into poly(lactic acid) (PLA)-based polymer at 10, 15 and 20% by weight. Film converting process consists of three steps including melt blending, sheet extrusion and biaxial stretching. The incorporation of antifungal compounds into the polymer matrix resulted in decreased Tg and Tm, increased gas permeabilility, reduced ...

  11. Materials and methods for efficient lactic acid production

    Zhou, Shengde; Ingram, Lonnie O& #x27; Neal; Shanmugam, Keelnatham T; Yomano, Lorraine; Grabar, Tammy B; Moore, Jonathan C

    2013-04-23

    The present invention provides derivatives of Escherichia coli constructed for the production of lactic acid. The transformed E. coli of the invention are prepared by deleting the genes that encode competing pathways followed by a growth-based selection for mutants with improved performance. These transformed E. coli are useful for providing an increased supply of lactic acid for use in food and industrial applications.

  12. Heat capacity of poly(lactic acid)

    Pyda, M.; Bopp, R.C.; Wunderlich, B.

    2004-01-01

    The heat capacity of poly(lactic acid) (PLA) is reported from T=(5 to 600) K as obtained by differential scanning calorimetry (d.s.c.) and adiabatic calorimetry. The heat capacity of solid PLA is linked to its group vibrational spectrum and the skeletal vibrations, the latter being described by a Tarasov equation with Θ 1 =574 K, Θ 2 =Θ 3 =52 K, and nine skeletal vibrations. The calculated and experimental heat capacities agree to ±3% between T=(5 and 300) K. The experimental heat capacity of liquid PLA can be expressed by C p (liquid)=(120.17+0.076T) J · K -1 · mol -1 and has been compared to the ATHAS Data Bank, using contributions of other polymers with the same constituent groups. The glass transition temperature of amorphous PLA occurs at T=332.5 K with a change in heat capacity of 43.8 J · K -1 · mol -1 . Depending on thermal history, semi-crystalline PLA has a melting endotherm between T=(418 and 432) K with variable heats of fusion. For 100% crystalline PLA, the heat of fusion is estimated to be (6.55 ± 0.02) kJ · mol -1 at T=480 K. With these results, the enthalpy, entropy, and Gibbs function of crystalline and amorphous PLA were obtained. For semi-crystalline samples, one can check changes of crystallinity with temperature and judge the presence of rigid-amorphous fractions

  13. Zinc Binding by Lactic Acid Bacteria

    Jasna Mrvčić

    2009-01-01

    Full Text Available Zinc is an essential trace element in all organisms. A common method for the prevention of zinc deficiency is pharmacological supplementation, especially in a highly available form of a metalloprotein complex. The potential of different microbes to bind essential and toxic heavy metals has recently been recognized. In this work, biosorption of zinc by lactic acid bacteria (LAB has been investigated. Specific LAB were assessed for their ability to bind zinc from a water solution. Significant amount of zinc ions was bound, and this binding was found to be LAB species-specific. Differences among the species in binding performance at a concentration range between 10–90 mg/L were evaluated with Langmuir model for biosorption. Binding of zinc was a fast process, strongly influenced by ionic strength, pH, biomass concentration, and temperature. The most effective metal-binding LAB species was Leuconostoc mesenteroides (27.10 mg of Zn2+ per gram of dry mass bound at pH=5 and 32 °C, during 24 h. FT-IR spectroscopy analysis and electron microscopy demonstrated that passive adsorption and active uptake of the zinc ions were involved.

  14. Examination of Lactic Acid Bacteria to Secretion of Bacteriocins

    Maira Urazova

    2014-01-01

    Full Text Available Introduction: Bacteriocins produced by lactic acid bacteria (LAB have the potential to cover a very broad field of applications, including the food industry and the medical sector. In the food industry, bacteriocinogenic LAB strains can be used as starter cultures, co-cultures, and bioprotective cultures, which would be used to improve food quality and safety. In the medical sector, bacteriocins of probiotic LAB might play a role in interactions, which take place in human gastrointestinal tract, and contribute to gut health. The aim of this study was the examine the effect of LAB antimicrobial activity. Methods: LAB were isolated from different commercial and home made products, such as kazy and sour cream. To screen for bacteriocin producing LAB, we used an agar diffusion bioassay, described in a previous study by Dr. Yang, with three modifications in cell-free supernatant (CFS. First we had a clear supernatant, second we adjusted the CFS to pH 6.0 to eliminate acids antimicrobial effects, and third the CFS pH 6.0 was treated with catalase to exclude the action of H2O2 and confirm action of bacteriocin-like substances. Pathogenic S.marcescens, E. coli, S.aureus cultures were used as indicators. Results: Screening of 95 strains of LAB through deferred antagonism to six indicator cultures showed that all of the selected strains had a high value of antibacterial activity. However, CFS of only 50 strains retained their antimicrobial activity, and 10 of them lost this activity in the second modification of CFS with pH 6.0 to test culture S.marcescens, which confirmed the acidic nature of antimicrobial activity of CFS. Lb.rhamnosus (P-1, Lb.fermentum (N-6, and Lc.lactis (7M lost antibacterial activity in the presence of the catalase. All modifications of CFS of three strains: Lb.pentosus (16al, Lb.pentosus (P-2, and Pediococcusacidilactici (8 retained inhibitory activity to E.coli and S. aureus. Supernatants of only Lactococcusgarvieae (10a and

  15. Metabolite Profiles of Lactic Acid Bacteria in Grass Silage▿

    Broberg, Anders; Jacobsson, Karin; Ström, Katrin; Schnürer, Johan

    2007-01-01

    The metabolite production of lactic acid bacteria (LAB) on silage was investigated. The aim was to compare the production of antifungal metabolites in silage with the production in liquid cultures previously studied in our laboratory. The following metabolites were found to be present at elevated concentrations in silos inoculated with LAB strains: 3-hydroxydecanoic acid, 2-hydroxy-4-methylpentanoic acid, benzoic acid, catechol, hydrocinnamic acid, salicylic acid, 3-phenyllactic acid, 4-hydro...

  16. Studying the Behavior of Lactic Acid Bacterias (BAL Culture Bioyogur to Different Doses of Magnetic Treatment

    Yarindra Mesa-Mariño

    2016-07-01

    Full Text Available Yogurt is beneficial in the prevention and restoration of intestinal diseases probiotic. It is obtained from fermentation of bacterial cultures as BIOyogur comprising Lactobacillus acidophilus and Streptococcus thermophilus. In the milk combined Santiago de Cuba, the low viability of these starter cultures for industrial production is 86 %, with a cell concentration of 5,89 log ufcmL-1, affecting fermentation and quality of soy yogurt. Knowing the stimulatingaction of electromagnetic fields (EMF 60 Hz on microorganisms of industrial interest, it is desired to decrease the fermentation time of the production process and improve product quality. Therefore treatment with electromagnetic field to starter cultures, which contributes to the improvement of fermentation time established industry standards and the final product quality, is proposed. For this, the effect of a 60 Hz EMC applying a multifactorial design with treatments 4, 6 and 8 mT at 5, 10 and 15 respectively min exposure was assessed; selecting factors as exposure time, the magnetic induction and prior inoculation. Obtaining as a variables response: growth lactic acid bacteria (LAB, pH and acidity. An increase of 10,38 log ufcmL-1 equal to a value of pH 3.80 and an acidity of 0,81 %, maintaining the quality parameters of the final product 6 mT and 5 min of the selected treatment.

  17. Longitudinal acoustic properties of poly(lactic acid) and poly(lactic-co-glycolic acid)

    Parker, N G; Povey, M J W; Mather, M L; Morgan, S P

    2010-01-01

    Acoustics offers rich possibilities for characterizing and monitoring the biopolymer structures being employed in the field of biomedical engineering. Here we explore the rudimentary acoustic properties of two common biodegradable polymers: poly(lactic acid) and poly(lactic-co-glycolic acid). A pulse-echo technique is developed to reveal the bulk speed of sound, acoustic impedance and acoustic attenuation of small samples of the polymer across a pertinent temperature range of 0-70 0 C. The glass transition appears markedly as both a discontinuity in the first derivative of the speed of sound and a sharp increase in the acoustic attenuation. We further extend our analysis to consider the role of ethanol, whose presence is observed to dramatically modify the acoustic properties and reduce the glass transition temperature of the polymers. Our results highlight the sensitivity of acoustic properties to a range of bulk properties, including visco-elasticity, molecular weight, co-polymer ratio, crystallinity and the presence of plasticizers.

  18. Engineering strategies aimed at control of acidification rate of lactic acid bacteria

    Martinussen, Jan; Solem, Christian; Holm, Anders Koefoed

    2013-01-01

    The ability of lactic acid bacteria to produce lactic acid from various sugars plays an important role in food fermentations. Lactic acid is derived from pyruvate, the end product of glycolysis and thus a fast lactic acid production rate requires a high glycolytic flux. In addition to lactic acid......, alternative end products - ethanol, acetic acid and formic acid - are formed by many species. The central role of glycolysis in lactic acid bacteria has provoked numerous studies aiming at identifying potential bottleneck(s) since knowledge about flux control could be important not only for optimizing food...

  19. Genetics of the proteolytic system of lactic acid bacteria

    Kok, Jan

    1990-01-01

    The proteolytic system of lactic acid bacteria is of eminent importance for the rapid growth of these organisms in protein-rich media. The combined action of proteinases and peptidases provides the cell with small peptides and essential amino acids. The amino acids and peptides thus liberated have

  20. Microbial granulation for lactic acid production.

    Kim, Dong-Hoon; Lee, Mo-Kwon; Hwang, Yuhoon; Im, Wan-Taek; Yun, Yeo-Myeong; Park, Chul; Kim, Mi-Sun

    2016-01-01

    This work investigated the formation of microbial granules to boost the productivity of lactic acid (LA). The flocculated form of LA-producing microbial consortium, dominated by Lactobacillus sp. (91.5% of total sequence), was initially obtained in a continuous stirred-tank reactor (CSTR), which was fed with 2% glucose and operated at a hydraulic retention time (HRT) of 12 h and pH 5.0 ± 0.1 under a thermophilic condition (50°C). The mixed liquor in the CSTR was then transferred to an up-flow anaerobic sludge blanket reactor (UASB). The fermentation performance and granulation process were monitored with a gradual decrease of HRT from 8.0 to 0.17 h, corresponding to an increase in the substrate loading from 60 to 2,880 g glucose L(-1) d(-1) . As the operation continued, the accumulation of biomass in the UASB was clearly observed, which changed from flocculent to granular form with decrease in HRT. Up to the HRT decrease to 0.5 h, the LA concentration was maintained at 19-20 g L(-1) with over 90% of substrate removal efficiency. However, further decrease of HRT resulted in a decrease of LA concentration with increase in residual glucose. Nevertheless, the volumetric LA productivity continuously increased, reaching 67 g L-fermenter (-1) h(-1) at HRT 0.17 h. The size of LA-producing granules and hydrophobicity gradually increased with decrease in HRT, reaching 6.0 mm and 60%, respectively. These biogranules were also found to have high settling velocities and low porosities, ranging 2.69-4.73 cm s(-1) and 0.39-0.92, respectively. © 2015 Wiley Periodicals, Inc.

  1. Isolation of a lactic acid bacterium and yeast consortium from a fermented material of Ulva spp. (Chlorophyta).

    Uchida, M; Murata, M

    2004-01-01

    Microbiota in a fermented culture of Ulva spp. was examined with the objective to characterize the type of fermentation and to obtain starter microbes for performing seaweed fermentation. Fermented Ulva spp. cultures which were obtained and transferred in a laboratory were examined for their microbiota. With phenotypic characterization and phylogenetic analysis based on rRNA gene nucleotide sequences, the predominant micro-organisms were identified as Lactobacillus brevis, Debaryomyces hanseni var. hansenii, and a Candida zeylanoides-related specimen, suggesting that the observed fermentation can be categorized to lactic acid and ethanol fermentation. Inoculating the individually cultured cell suspensions of the three kinds of micro-organisms with cellulase induced the fermentation in various kinds of seaweed. A microbial consortium composed of a lactic acid bacterium, L. brevis, and yeasts, D. hansenii and a C. zeylanoides-related specimen, were predominant in a fermented culture of Ulva spp. Lactic acid and ethanol fermentation could be induced in various kinds of seaweed by adding this microbial consortium along with cellulase. This is the first report of lactic acid and ethanol fermentation in seaweed, which is expected to provide a new material for food and dietary applications.

  2. Analysis of the lactic acid bacteria microflora in traditional Caucasus cow's milk cheeses

    Terzić-Vidojević Amarela

    2009-01-01

    Full Text Available A total of 157 lactic acid bacteria (LAB were isolated from three hand-made cheeses taken from different households in the region of the Caucasus Mountains. The cheeses were manufactured from cow's milk without the addition of a starter culture. The isolates of LAB were characterized by subjecting them to phenotypic and genotypic tests. The results of identification of LAB indicate that the examined cheeses contained 10 species, viz., Lactobacillus plantarum, Lactobacillus paraplantarum, Lactobacillus arizonensis, Lactobacillus farciminis, Lactobacillus brevis, Lactococcus lactis subsp. lactis, Leuconostoc mesenteroides subsp. mesenteroides, Leuconostoc pseudomesenteroides, Enterococcus faecium, and Enterococcus faecalis. The strains within the species L. plantarum, L. arizonensis, L. paraplantarum, L. farciminis, and L. pseudomesenteroides showed good proteolytic activity.

  3. Decomposition and detoxification of aflatoxin B1 by lactic acid.

    Aiko, Visenuo; Edamana, Prasad; Mehta, Alka

    2016-04-01

    A degradation study of aflatoxin B1 (AFB1) was carried out using a combination of physical and chemical methods. AFB1 was heated at 80 °C in the presence of acetic, citric and lactic acids for various time periods. The cytotoxicity of the degraded AFB1 and its products were determined by MTT assay. The results showed that among the three organic acids lactic acid was most efficient in degrading AFB1. Although complete degradation was not observed, up to 85% degradation of AFB1 was obtained when heated for 120 min. Degradation of AFB1 was confirmed by the reduced toxicity on HeLa cells using MTT assay. Treatment with lactic acid resulted in the conversion of AFB1 into two degradation products. These products were observed at lower retention factors of 0.63 and 0.38, which were identified as AFB2 and AFB2a, respectively. The cytotoxicity of AFB2a exhibited much reduced toxicity on HeLa cells compared to that of AFB1. The results have shown the efficiency of lactic acid in degrading AFB1. This study suggest that lactic acid may be considered for use in the food and feed industry since it is present naturally in food and is considered safe. © 2015 Society of Chemical Industry.

  4. Improving the antioxidant properties of quinoa flour through fermentation with selected autochthonous lactic acid bacteria.

    Rizzello, Carlo Giuseppe; Lorusso, Anna; Russo, Vito; Pinto, Daniela; Marzani, Barbara; Gobbetti, Marco

    2017-01-16

    Lactic acid bacteria strains, previously isolated from the same matrix, were used to ferment quinoa flour aiming at exploiting the antioxidant potential. As in vitro determined on DPPH and ABTS radicals, the scavenging activity of water/salt-soluble extracts (WSE) from fermented doughs was significantly (Pquinoa dough fermented with Lactobacillus plantarum T0A10. The corresponding WSE was subjected to Reverse Phase Fast Protein Liquid Chromatography, and 32 fractions were collected and subjected to in vitro assays. The most active fraction was resistant to further hydrolysis by digestive enzymes. Five peptides, having sizes from 5 to 9 amino acid residues, were identified by nano-Liquid Chromatography-Electrospray Ionisation-Mass Spectra/Mass Spectra. The sequences shared compositional features which are typical of antioxidant peptides. As shown by determining cell viability and radical scavenging activity (MTT and DCFH-DA assays, respectively), the purified fraction showed antioxidant activity on human keratinocytes NCTC 2544 artificially subjected to oxidative stress. This study demonstrated the capacity of autochthonous lactic acid bacteria to release peptides with antioxidant activity through proteolysis of native quinoa proteins. Fermentation of the quinoa flour with a selected starter might be considered suitable for novel applications as functional food ingredient, dietary supplement or pharmaceutical preparations. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Selection of potential probiotic lactic acid bacteria from fermented olives by in vitro tests.

    Argyri, Anthoula A; Zoumpopoulou, Georgia; Karatzas, Kimon-Andreas G; Tsakalidou, Effie; Nychas, George-John E; Panagou, Efstathios Z; Tassou, Chrysoula C

    2013-04-01

    The present study aims to evaluate the probiotic potential of lactic acid bacteria (LAB) isolated from naturally fermented olives and select candidates to be used as probiotic starters for the improvement of the traditional fermentation process and the production of newly added value functional foods. Seventy one (71) lactic acid bacterial strains (17 Leuconostoc mesenteroides, 1 Ln. pseudomesenteroides, 13 Lactobacillus plantarum, 37 Lb. pentosus, 1 Lb. paraplantarum, and 2 Lb. paracasei subsp. paracasei) isolated from table olives were screened for their probiotic potential. Lb. rhamnosus GG and Lb. casei Shirota were used as reference strains. The in vitro tests included survival in simulated gastrointestinal tract conditions, antimicrobial activity (against Listeria monocytogenes, Salmonella Enteritidis, Escherichia coli O157:H7), Caco-2 surface adhesion, resistance to 9 antibiotics and haemolytic activity. Three (3) Lb. pentosus, 4 Lb. plantarum and 2 Lb. paracasei subsp. paracasei strains demonstrated the highest final population (>8 log cfu/ml) after 3 h of exposure at low pH. The majority of the tested strains were resistant to bile salts even after 4 h of exposure, while 5 Lb. plantarum and 7 Lb. pentosus strains exhibited partial bile salt hydrolase activity. None of the strains inhibited the growth of the pathogens tested. Variable efficiency to adhere to Caco-2 cells was observed. This was the same regarding strains' susceptibility towards different antibiotics. None of the strains exhibited β-haemolytic activity. As a whole, 4 strains of Lb. pentosus, 3 strains of Lb. plantarum and 2 strains of Lb. paracasei subsp. paracasei were found to possess desirable in vitro probiotic properties similar to or even better than the reference probiotic strains Lb. casei Shirota and Lb. rhamnosus GG. These strains are good candidates for further investigation both with in vivo studies to elucidate their potential health benefits and in olive fermentation processes

  6. Lactic Acid Bacterial Vaginosis among Outpatients in Addis Ababa ...

    Background: Bacterial vaginosis (BV) is a polymicrobial syndrome in which a decrease in vaginal acidity and concentration of lactobacilli is accompanied by an increase of other pathogenic micro-organisms. The distribution of lactic acid bacteria in vaginal environment of Ethiopian women has not been documented.

  7. Selection of local extremophile lactic acid bacteria with high capacity ...

    This study is related to the isolation and identification of strains of local thermophilic lactic acid bacteria belonging to the species, Streptococcus thermophilus and Lactobacillus bulgaricus. These bacteria can exist under extreme conditions of the digestive tract (acidity and high concentration of bile salts) and have a high ...

  8. Optimization of lactic acid production with immobilized Rhizopus ...

    sule

    2012-04-26

    Apr 26, 2012 ... Lactic acid is the most widely utilized organic acid in the food, pharmaceutical, cosmetics and chemical industries. One of its most promising applications is for used biodegradable and ... polymer supports, by embedding with natural polymers like alginate gels and synthetic polymers (Tamada et al.,. 1992).

  9. Lactic acid fermentation of cassava dough into agbelima.

    Amoa-Awua, W K; Appoh, F E; Jakobsen, M

    1996-08-01

    The souring of cassava dough during fermentation into the fermented cassava meal, agbelima, was investigated. Four different types of traditional inocula were used to ferment the dough and increases in titrable acidity expressed as lactic acid from 0.31-0.38 to 0.78-0.91% (w/w) confirmed the fermentation to be a process of acidification. The microflora of all inocula and fermenting dough contained high counts of lactic acid bacteria, 10(8)-10(9) cfu/g in all inocula and 10(7)-10(8), 10(8)-10(9) and 10(9) cfu/g at 0, 24 and 48 h in all fermentations. Lactobacillus plantarum was the dominant species of lactic acid bacteria during all types of fermentation accounting for 51% of 171 representative isolates taken from various stages of fermentation. Other major lactic acid bacteria found were Lactobacillus brevis, 16%, Leuconostoc mesenteroides, 15% and some cocci including Streptococcus spp. whose numbers decreased with fermentation time. The lactic acid bacteria were responsible for the souring of agbelima through the production of lactic acid. All L. plantarum, L. brevis and L. mesenteroides isolates examined demonstrated linamarase as well as other enzymatic activities but did not possess tissue degrading enzymes like cellulase, pectin esterase and polygalacturonase. The aroma profile of agbelima did not vary with the type of inoculum used and in all samples the build-up of aroma compounds were dominated by a non-identified low molecular weight alcohol, 1-propanol, isoamyl alcohol, ethyl acetate, 3-methyl-1-butanol and acetoin. Substantial reductions occurred in the levels of cyanogenic compounds present in cassava during fermentation into agbelima and detoxification was enhanced by the use of inoculum.

  10. Development of Poly (Lactic Acid) Nanocomposite Films by Ionizing Radiation

    Dadbin, Susan; Naimian, Faranak; Akhavan, Azam; Hasanpoor, Sorour [Radiation Application Research School, Nuclear Science and Research Institute, North Kargar Ave., Tehran (Iran, Islamic Republic of)

    2009-07-01

    Poly (lactic acid) and poly (lactic acid) -montmorillonite (MMT) nanocomposite films have been prepared by solvent casting method. Films were irradiated with 60Co radiation facility at various doses in the range of 5 to30 kGy. The effect of gamma irradiation on mechanical properties of neat PLA and nanocomposites is evaluated by the data obtained from tensile testing measurements. The degree of crosslinking is measured by gel content method. Thermal behavior of nanocomposites is studied by differential scanning calorimetry (DSC) and thermal gravimetry analysis (TGA). The morphology of the nanocomposites is characterized by transmission electron microscopy (TEM) and X ray diffraction. Structural changes in poly (lactic acid) are studied by Fourier transform infrared (FTIR). (author)

  11. Development of Poly (Lactic Acid) Nanocomposite Films by Ionizing Radiation

    Dadbin, Susan; Naimian, Faranak; Akhavan, Azam; Hasanpoor, Sorour

    2009-01-01

    Poly (lactic acid) and poly (lactic acid) -montmorillonite (MMT) nanocomposite films have been prepared by solvent casting method. Films were irradiated with 60Co radiation facility at various doses in the range of 5 to30 kGy. The effect of gamma irradiation on mechanical properties of neat PLA and nanocomposites is evaluated by the data obtained from tensile testing measurements. The degree of crosslinking is measured by gel content method. Thermal behavior of nanocomposites is studied by differential scanning calorimetry (DSC) and thermal gravimetry analysis (TGA). The morphology of the nanocomposites is characterized by transmission electron microscopy (TEM) and X ray diffraction. Structural changes in poly (lactic acid) are studied by Fourier transform infrared (FTIR). (author)

  12. Nucleotide Metabolism and its Control in Lactic Acid Bacteria

    Kilstrup, Mogens; Hammer, Karin; Jensen, Peter Ruhdal

    2005-01-01

    Most metabolic reactions are connected through either their utilization of nucleotides or their utilization of nucleotides or their regulation by these metabolites. In this review the biosynthetic pathways for pyrimidine and purine metabolism in lactic acid bacteria are described including...... the interconversion pathways, the formation of deoxyribonucleotides and the salvage pathways for use of exogenous precursors. The data for the enzymatic and the genetic regulation of these pathways are reviewed, as well as the gene organizations in different lactic acid bacteria. Mutant phenotypes and methods...... for manipulation of nucleotide pools are also discussed. Our aim is to provide an overview of the physiology and genetics of nucleotide metabolism and its regulation that will facilitate the interpretation of data arising from genetics, metabolomics, proteomics, and transcriptomics in lactic acid bacteria....

  13. The influence of a cryoprotective medium containing glycerol on the lyophilization of lactic acid bacteria (NOTE

    JOSIP BARAS

    2001-07-01

    Full Text Available The aims of liophilization (freeze-drying of lactic acid bacteria are to preserve pure cultures or to prepare starters for the dairy industry. In both cases, the choice of the cryoprotectant is very important. In this work, samples of Bifidobacterium breve A71 and Bifidobacterium bifidum BbTD were freeze-dried in a new cryoprotective medium containing lactose, gelatine and glycerol (medium B. The reference medium contained saccharose, gelatine and skim milk (medium A. Before liophilization, the eutectic points of both media were determined, because the products must be cooled to a temperature below its freezing point. The success of the cryoprotectants was estimated in terms of the number of surviving organisms after lyophilization. Bifidobacterium breve A71 and Bifidobacterium bifidum BbTD freeze-dried in media A and B showed high survival rates. Bifidobacterium breve A71 showed a greater percentage survival in combination with medium B than with medium A. These results could be utilized in the manufacture of Bifidobacterium breve A71 as a starter in the diary industry because it is a human isolate which, except for acidification, has probiotic activity.

  14. Production of L-lactic Acid from Biomass Wastes Using Scallop Crude Enzymes and Novel Lactic Acid Bacterium

    Yanagisawa, Mitsunori; Nakamura, Kanami; Nakasaki, Kiyohiko

    In the present study, biomass waste raw materials including paper mill sludge, bamboo, sea lettuce, and shochu residue (from a distiller) and crude enzymes derived from inedible and discarded scallop parts were used to produce L-lactic acid for the raw material of biodegradable plastic poly-lactic acid. The activities of cellulase and amylase in the crude enzymes were 22 and 170units/L, respectively, and L-lactic acid was produced from every of the above mentioned biomass wastes, by the method of liquid-state simultaneous saccharification and fermentation (SSF) . The L-lactic acid concentrations produced from sea lettuce and shochu residue, which contain high concentration of starch were 3.6 and 9.3g/L, respectively, and corresponded to greater than 25% of the conversion of glucans contained in these biomass wastes. Furthermore, using the solid state SSF method, concentrations as high as 13g/L of L-lactic acid were obtained from sea lettuce and 26g/L were obtained from shochu residue.

  15. Lactic Acid and Biosurfactants Production from Residual Cellulose Films.

    Portilla Rivera, Oscar Manuel; Arzate Martínez, Guillermo; Jarquín Enríquez, Lorenzo; Vázquez Landaverde, Pedro Alberto; Domínguez González, José Manuel

    2015-11-01

    The increasing amounts of residual cellulose films generated as wastes all over the world represent a big scale problem for the meat industry regarding to environmental and economic issues. The use of residual cellulose films as a feedstock of glucose-containing solutions by acid hydrolysis and further fermentation into lactic acid and biosurfactants was evaluated as a method to diminish and revalorize these wastes. Under a treatment consisting in sulfuric acid 6% (v/v); reaction time 2 h; solid liquid ratio 9 g of film/100 mL of acid solution, and temperature 130 °C, 35 g/L of glucose and 49% of solubilized film was obtained. From five lactic acid strains, Lactobacillus plantarum was the most suitable for metabolizing the glucose generated. The process was scaled up under optimized conditions in a 2-L bioreactor, producing 3.4 g/L of biomass, 18 g/L of lactic acid, and 15 units of surface tension reduction of a buffer phosphate solution. Around 50% of the cellulose was degraded by the treatment applied, and the liqueurs generated were useful for an efficient production of lactic acid and biosurfactants using L. plantarum. Lactobacillus bacteria can efficiently utilize glucose from cellulose films hydrolysis without the need of clarification of the liqueurs.

  16. Lactose behaviour in the presence of lactic acid and calcium.

    Wijayasinghe, Rangani; Vasiljevic, Todor; Chandrapala, Jayani

    2016-08-01

    Physical properties of lactose appeared influenced by presence of lactic acid in the system. Some other components such as Ca may further attenuate lactose behaviour and impact its phase transition. A model-based study was thus implemented with varying concentrations of Ca (0·12, 0·072 or 0·035% w/w) and lactic acid (0·05, 0·2, 0·4 or 1% w/w) in establishing the effects of these two main acid whey constituents on lactose phase behaviour. Concentrated solutions (50% w/w) containing lactose, lactic acid and Ca were analysed for thermal behaviour and structural changes by Differential Scanning Colorimetry (DSC) and Fourier Transform Infrared Spectroscopy (FTIR), respectively. Presence of 1% (w/w) lactic acid and 0·12% (w/w) Ca in lactose solution significantly increased the evaporation enthalpy of water, delayed and increased the energy required for lactose crystallisation as compared to pure lactose. FTIR analysis indicated a strong hydration layer surrounding lactose molecules, restricting water mobility and/or inducing structural changes of lactose, hindering its crystallisation. The formation of calcium lactate, which restricts the diffusion of lactose molecules, is also partly responsible. It appears that Ca removal from acid whey may be a necessary step in improving the processability of acid whey.

  17. 40 CFR 180.1090 - Lactic acid; exemption from the requirement of a tolerance.

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Lactic acid; exemption from the... Exemptions From Tolerances § 180.1090 Lactic acid; exemption from the requirement of a tolerance. Lactic acid (2-hydroxypropanoic acid) is exempted from the requirement of a tolerance when used as a plant growth...

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

    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.

  19. Lactic acid bacteria and the human gastrointestinal tract

    Hove, H; Nørgaard, H; Mortensen, P B

    1999-01-01

    OBJECTIVE: This review summarises the effects of lactic acid bacteria on lactose malabsorption, bacterial/viral or antibiotic associated diarrhoea, and describes the impact of lactic acid bacteria on cancer and the fermentative products in the colon. RESULTS: Eight studies (including 78 patients......) demonstrated that lactase deficient subjects absorbed lactose in yogurt better than lactose in milk, while two studies (25 patients) did not support this. Two studies (22 patients) showed that unfermented acidophilus milk was absorbed better than milk, while six studies (68 patients) found no significant...

  20. Antifungal Poly(lactic acid Films Containing Thymol and Carvone

    Boonruang Kanchana

    2016-01-01

    Full Text Available The goal of this study was to develop antifungal poly(lactic acid films for food packaging applications. The antifungal compounds, thymol and R-(--carvone were incorporated into poly(lactic acid (PLA-based polymer at 10, 15 and 20% by weight. Film converting process consists of three steps including melt blending, sheet extrusion and biaxial stretching. The incorporation of antifungal compounds into the polymer matrix resulted in decreased Tg and Tm, increased gas permeabilility, reduced tensile strength and increased elongation at break of the antifungal PLA films.

  1. Neuropathic Pain Following Poly-L-Lactic Acid (Sculptra) Injection.

    Vrcek, Ivan; El-Sawy, Tarek; Chou, Eva; Allen, Theresa; Nakra, Tanuj

    Injectable fillers have become a prevalent means of facial rejuvenation and volume expansion. While typically well tolerated, serious complications have been reported. The authors present a case in which an otherwise healthy female with a history of multiple filler injections including poly-L-lactic acid, developed 3 weeks of neuropathic pain in the left temporal fossa following injection. To the best of the authors knowledge, neuropathic pain has not been reported as a complication following poly-L-lactic acid injection. The patient was treated with an injection of steroid and long-acting anesthetic with resolution of symptoms.

  2. ASIC3: A Lactic Acid Sensor for Cardiac Pain

    D.C. Immke

    2001-01-01

    Full Text Available Angina, the prototypic vasoocclusive pain, is a radiating chest pain that occurs when heart muscle gets insufficient blood because of coronary artery disease. Other examples of vasoocclusive pain include the acute pain of heart attack and the intermittent pains that accompany sickle cell anemia and peripheral artery disease. All these conditions cause ischemia � insufficient oxygen delivery for local metabolic demand — and this releases lactic acid as cells switch to anaerobic metabolism. Recent discoveries demonstrate that sensory neurons innervating the heart are richly endowed with an ion channel that is opened by, and perfectly tuned for, the lactic acid released by muscle ischemia[1,2].

  3. Probiotic lactic acid bacteria ? the fledgling cuckoos of the gut?

    Berstad, Arnold; Raa, Jan; Midtvedt, Tore; Valeur, J?rgen

    2016-01-01

    It is tempting to look at bacteria from our human egocentric point of view and label them as either ‘good’ or ‘bad’. However, a microbial society has its own system of government – ‘microcracy’ – and its own rules of play. Lactic acid bacteria are often referred to as representatives of the good ones, and there is little doubt that those belonging to the normal intestinal flora are beneficial for human health. But we should stop thinking of lactic acid bacteria as always being ‘friendly’ – th...

  4. Probiotic lactic acid bacteria - the fledgling cuckoos of the gut?

    Berstad, Arnold; Raa, Jan; Midtvedt, Tore; Valeur, Jørgen

    2016-01-01

    It is tempting to look at bacteria from our human egocentric point of view and label them as either 'good' or 'bad'. However, a microbial society has its own system of government - 'microcracy' - and its own rules of play. Lactic acid bacteria are often referred to as representatives of the good ones, and there is little doubt that those belonging to the normal intestinal flora are beneficial for human health. But we should stop thinking of lactic acid bacteria as always being 'friendly' - they may instead behave like fledgling cuckoos.

  5. Preparation of lactic acid bacteria fermented wheat-yoghurt mixtures.

    Magala, Michal; Kohajdová, Zlatica; Karovičová, Jolana

    2013-01-01

    Tarhana, a wheat-yoghurt fermented mixture, is considered as a good source of saccharides, proteins, some vitamins and minerals. Moreover, their preparation is inexpensive and lactic acid fermentation offers benefits like product preservation, enhancement of nutritive value and sensory properties improvement. The aim of this work was to evaluate changes of some chemical parameters during fermentation of tarhana, when the level of salt and amount of yoghurt used were varied. Some functional and sensory characteristics of the fi nal product were also determined. Chemical analysis included determination of pH, titrable acidity, content of reducing saccharides, lactic, acetic and citric acid. Measured functional properties of tarhana powder were foaming capacity, foam stability, water absorption capacity, oil absorption capacity and emulsifying activity. Tarhana soups samples were evaluated for their sensory characteristics (colour, odor, taste, consistency and overall acceptability). Fermentation of tarhana by lactic acid bacteria and yeasts led to decrease in pH, content of reducing saccharides and citric acid, while titrable acidity and concentration of lactic and acetic acid increased. Determination of functional properties of tarhana powder showed, that salt absence and increased amount of yoghurt in tarhana recipe reduced foaming capacity and oil absorption capacity, whereas foam stability and water absorption capacity were improved. Sensory evaluation of tarhana soups showed that variations in tarhana recipe adversly affected sensory parameters of fi nal products. Variations in tarhana recipe (salt absence, increased proportion of yoghurt) led to changes in some chemical parameters (pH, titrable acidity, reducing saccharides, content of lactic, acetic and citric acid). Functional properties were also affected with changed tarhana recipe. Sensory characteristics determination showed, that standard tarhana fermented for 144 h had the highest overall acceptability.

  6. Influence of sodium chloride, pH, and lactic acid bacteria on anaerobic lactic acid utilization during fermented cucumber spoilage.

    Johanningsmeier, Suzanne D; Franco, Wendy; Perez-Diaz, Ilenys; McFeeters, Roger F

    2012-07-01

    Cucumbers are preserved commercially by natural fermentations in 5% to 8% sodium chloride (NaCl) brines. Occasionally, fermented cucumbers spoil after the primary fermentation is complete. This spoilage has been characterized by decreases in lactic acid and a rise in brine pH caused by microbial instability. Objectives of this study were to determine the combined effects of NaCl and pH on fermented cucumber spoilage and to determine the ability of lactic acid bacteria (LAB) spoilage isolates to initiate lactic acid degradation in fermented cucumbers. Cucumbers fermented with 0%, 2%, 4%, and 6% NaCl were blended into slurries (FCS) and adjusted to pH 3.2, 3.8, 4.3, and 5.0 prior to centrifugation, sterile-filtration, and inoculation with spoilage organisms. Organic acids and pH were measured initially and after 3 wk, 2, 6, 12, and 18 mo anaerobic incubation at 25 °C. Anaerobic lactic acid degradation occurred in FCS at pH 3.8, 4.3, and 5.0 regardless of NaCl concentration. At pH 3.2, reduced NaCl concentrations resulted in increased susceptibility to spoilage, indicating that the pH limit for lactic acid utilization in reduced NaCl fermented cucumbers is 3.2 or lower. Over 18 mo incubation, only cucumbers fermented with 6% NaCl to pH 3.2 prevented anaerobic lactic acid degradation by spoilage bacteria. Among several LAB species isolated from fermented cucumber spoilage, Lactobacillus buchneri was unique in its ability to metabolize lactic acid in FCS with concurrent increases in acetic acid and 1,2-propanediol. Therefore, L. buchneri may be one of multiple organisms that contribute to development of fermented cucumber spoilage. Microbial spoilage of fermented cucumbers during bulk storage causes economic losses for producers. Current knowledge is insufficient to predict or control these losses. This study demonstrated that in the absence of oxygen, cucumbers fermented with 6% sodium chloride to pH 3.2 were not subject to spoilage. However, lactic acid was degraded

  7. 49-60 Characterization of Lactic Acid Bacteria from Camel Milk and the

    Reviwer

    bacteria in the food industry is the lactic acid bacteria. (LAB) which are used ... Weinberg et al., 2007) as well as for their preservative ... Food and Drug Administration FDA (2003). In the ... lactic acid bacteria species were characterized as fast.

  8. Comparative analysis of poly-glycolic acid-based hybrid polymer starter matrices for in vitro tissue engineering.

    Generali, Melanie; Kehl, Debora; Capulli, Andrew K; Parker, Kevin K; Hoerstrup, Simon P; Weber, Benedikt

    2017-10-01

    Biodegradable scaffold matrixes form the basis of any in vitro tissue engineering approach by acting as a temporary matrix for cell proliferation and extracellular matrix deposition until the scaffold is replaced by neo-tissue. In this context several synthetic polymers have been investigated, however a concise systematic comparative analyses is missing. Therefore, the present study systematically compares three frequently used polymers for the in vitro engineering of extracellular matrix based on poly-glycolic acid (PGA) under static as well as dynamic conditions. Ultra-structural analysis was used to examine the polymers structure. For tissue engineering (TE) three human fibroblast cell lines were seeded on either PGA-poly-4-hydroxybutyrate (P4HB), PGA-poly-lactic acid (PLA) or PGA-poly-caprolactone (PCL) patches. These patches were analyzed after 21days of culture qualitative by histology and quantitative by determining the amount of DNA, glycosaminoglycan and hydroxyproline. We found that PGA-P4HB and PGA-PLA scaffolds enhance tissue formation significantly higher than PGA-PCL scaffolds (p<0.05). Polymer remnants were visualized by polarization microscopy. In addition, biomechanical properties of the tissue engineered patches were determined in comparison to native tissue. This study may allow future studies to specifically select certain polymer starter matrices aiming at specific tissue properties of the bioengineered constructs in vitro. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Potential of lactic acid bacteria as suppressors of wine allergies

    Yıldırım Hatice Kalkan

    2017-01-01

    Full Text Available Allergens causes some symptoms as all asthma, allergic conjunctivitis, and allergic rhinitis. These symptoms are seen twice as many in women than in men. The major wine allergens reported in wines are endochitinase 4A and lipid-transfer protein (LTP. This review deal with possibilities of using lactic acid bacteria as suppressors of wine allergies. Phenolic compounds present in wines have not only antioxidant properties causing radical scavenging but also some special properties reported in many in vitro studies as regulating functions in inflammatory cells as mast cells. So what is the role of lactic acid bacteria in these cases? Lactic acid bacteria are used during malolactic fermentation step of wine production with purpose of malic acid reduction. During this bioconversion complex phenolic compounds could be hydrolysed by bacterial enzymes to their aglycone forms. Obtained aglycons could pass through the intestinal epithelium of human and allowed reduction of IgE antibody production by affecting Th1/ Th2 ratio. Considering different contents and quantities of phenols in different grape varieties and consequently in different wines more studies are required in order to determine which lactic acid bacteria and strains could be effective in suppressing wine allergens.

  10. Effects of lactic acid on astrocytes in primary culture.

    Norenberg, M D; Mozes, L W; Gregorios, J B; Norenberg, L O

    1987-03-01

    Excessive tissue lactic acidosis is considered to be detrimental to the central nervous system (CNS) and may adversely affect recovery from anoxia, ischemia, trauma and epilepsy. Since astrocytes are believed to play a role in pH regulation in the CNS, we studied the effect of this acid on primary astrocyte cultures. Cells exposed to lactic acid showed chromatin clumping, an increase of lipid and dense bodies, a loss of polyribosomal clusters, slightly increased cytoplasmic lucency, swollen mitochondria and tangled intermediate filaments. These alterations progressed with lower pH and longer exposure. Irreversible changes occurred one to two hours after exposure at pH 6; after 30 to 60 minutes (min) at pH 5.5 and after ten to 30 min at pH 5. Comparable results were obtained with the use of other weak acids indicating that the observed changes were due to increased hydrogen ion concentration rather than secondary to lactate per se. Additionally, various concentrations of lactic acid adjusted to identical pH produced similar morphologic alterations. Thus, while lactic acid caused marked and at times irreversible alterations in astrocytes, severe and prolonged acidosis was required to produce such injurious effects. This relative resistance of astrocytes to acidosis is in keeping with their potential role in pH regulation in brain.

  11. The production of lactic acid on liquid distillery stillage by Lactobacillus rhamnosus ATCC 7469

    Đukić-Vuković, Aleksandra; Mojović, Ljiljana; Pejin, Dušanka; Vukašinović-Sekulić, Maja; Rakin, Marica; Nikolić, Svetlana; Pejin, Jelena

    2011-01-01

    The production of lactic acid on a liquid distillery stillage remaining after the bioethanol production on a mixture of waste bread and waste water from the production of wheat gluten was studied in this work. The lactic acid fermentation was performed with a probiotic lactic acid bacteria Lactobacillus rhamnosus ATCC 7469. During the fermentation, parameters such as the concentration of lactic acid (according to Taylor method), the concentration of reducing sugars (spectrophotometric method ...

  12. Antagonism Between Osmophilic Lactic Acid Bacteria and Yeasts in Brine Fermentation of Soy Sauce

    Noda, Fumio; Hayashi, Kazuya; Mizunuma, Takeji

    1980-01-01

    Brine fermentation by osmophilic lactic acid bacteria and yeasts for long periods of time is essential to produce a good quality of shoyu (Japanese fermented soy sauce). It is well known that lactic acid fermentation by osmophilic lactic acid bacteria results in the depression of alcoholic fermentation by osmophilic yeasts, but the nature of the interaction between osmophilic lactic acid bacteria and yeasts in brine fermentation of shoyu has not been revealed. The inhibitory effect of osmophi...

  13. Lactic acid production from xylose by engineered Saccharomyces cerevisiae without PDC or ADH deletion

    Production of lactic acid from renewable sugars has received growing attention as lactic acid can be used for making renewable and bio-based plastics. However, most prior studies have focused on production of lactic acid from glucose despite cellulosic hydrolysates contain xylose as well as glucose....

  14. Lactic acid production from xylose by engineered Saccharomyces cerevisiae without PDC or ADH deletion.

    Turner, Timothy L; Zhang, Guo-Chang; Kim, Soo Rin; Subramaniam, Vijay; Steffen, David; Skory, Christopher D; Jang, Ji Yeon; Yu, Byung Jo; Jin, Yong-Su

    2015-10-01

    Production of lactic acid from renewable sugars has received growing attention as lactic acid can be used for making renewable and bio-based plastics. However, most prior studies have focused on production of lactic acid from glucose despite that cellulosic hydrolysates contain xylose as well as glucose. Microbial strains capable of fermenting both glucose and xylose into lactic acid are needed for sustainable and economic lactic acid production. In this study, we introduced a lactic acid-producing pathway into an engineered Saccharomyces cerevisiae capable of fermenting xylose. Specifically, ldhA from the fungi Rhizopus oryzae was overexpressed under the control of the PGK1 promoter through integration of the expression cassette in the chromosome. The resulting strain exhibited a high lactate dehydrogenase activity and produced lactic acid from glucose or xylose. Interestingly, we observed that the engineered strain exhibited substrate-dependent product formation. When the engineered yeast was cultured on glucose, the major fermentation product was ethanol while lactic acid was a minor product. In contrast, the engineered yeast produced lactic acid almost exclusively when cultured on xylose under oxygen-limited conditions. The yields of ethanol and lactic acid from glucose were 0.31 g ethanol/g glucose and 0.22 g lactic acid/g glucose, respectively. On xylose, the yields of ethanol and lactic acid were substrates.

  15. Lactic acid delays the inflammatory response of human monocytes

    Peter, Katrin, E-mail: katrin.peter@ukr.de [Department of Internal Medicine III, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg (Germany); Rehli, Michael, E-mail: michael.rehli@ukr.de [Department of Internal Medicine III, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg (Germany); RCI Regensburg Center for Interventional Immunology, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg (Germany); Singer, Katrin, E-mail: katrin.singer@ukr.de [Department of Internal Medicine III, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg (Germany); Renner-Sattler, Kathrin, E-mail: kathrin.renner-sattler@ukr.de [Department of Internal Medicine III, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg (Germany); Kreutz, Marina, E-mail: marina.kreutz@ukr.de [Department of Internal Medicine III, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg (Germany); RCI Regensburg Center for Interventional Immunology, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg (Germany)

    2015-02-13

    Lactic acid (LA) accumulates under inflammatory conditions, e.g. in wounds or tumors, and influences local immune cell functions. We previously noted inhibitory effects of LA on glycolysis and TNF secretion of human LPS-stimulated monocytes. Here, we globally analyze the influence of LA on gene expression during monocyte activation. To separate LA-specific from lactate- or pH-effects, monocytes were treated for one or four hours with LPS in the presence of physiological concentrations of LA, sodium lactate (NaL) or acidic pH. Analyses of global gene expression profiles revealed striking effects of LA during the early stimulation phase. Up-regulation of most LPS-induced genes was significantly delayed in the presence of LA, while this inhibitory effect was attenuated in acidified samples and not detected after incubation with NaL. LA targets included genes encoding for important monocyte effector proteins like cytokines (e.g. TNF and IL-23) or chemokines (e.g. CCL2 and CCL7). LA effects were validated for several targets by quantitative RT-PCR and/or ELISA. Further analysis of LPS-signaling pathways revealed that LA delayed the phosphorylation of protein kinase B (AKT) as well as the degradation of IκBα. Consistently, the LPS-induced nuclear accumulation of NFκB was also diminished in response to LA. These results indicate that the broad effect of LA on gene expression and function of human monocytes is at least partially caused by its interference with immediate signal transduction events after activation. This mechanism might contribute to monocyte suppression in the tumor environment. - Highlights: • Lactic acid broadly delays LPS-induced gene expression in human monocytes. • Expression of important monocyte effector molecules is affected by lactic acid. • Interference of lactic acid with TLR signaling causes the delayed gene expression. • The profound effect of lactic acid might contribute to immune suppression in tumors.

  16. Lactic acid delays the inflammatory response of human monocytes

    Peter, Katrin; Rehli, Michael; Singer, Katrin; Renner-Sattler, Kathrin; Kreutz, Marina

    2015-01-01

    Lactic acid (LA) accumulates under inflammatory conditions, e.g. in wounds or tumors, and influences local immune cell functions. We previously noted inhibitory effects of LA on glycolysis and TNF secretion of human LPS-stimulated monocytes. Here, we globally analyze the influence of LA on gene expression during monocyte activation. To separate LA-specific from lactate- or pH-effects, monocytes were treated for one or four hours with LPS in the presence of physiological concentrations of LA, sodium lactate (NaL) or acidic pH. Analyses of global gene expression profiles revealed striking effects of LA during the early stimulation phase. Up-regulation of most LPS-induced genes was significantly delayed in the presence of LA, while this inhibitory effect was attenuated in acidified samples and not detected after incubation with NaL. LA targets included genes encoding for important monocyte effector proteins like cytokines (e.g. TNF and IL-23) or chemokines (e.g. CCL2 and CCL7). LA effects were validated for several targets by quantitative RT-PCR and/or ELISA. Further analysis of LPS-signaling pathways revealed that LA delayed the phosphorylation of protein kinase B (AKT) as well as the degradation of IκBα. Consistently, the LPS-induced nuclear accumulation of NFκB was also diminished in response to LA. These results indicate that the broad effect of LA on gene expression and function of human monocytes is at least partially caused by its interference with immediate signal transduction events after activation. This mechanism might contribute to monocyte suppression in the tumor environment. - Highlights: • Lactic acid broadly delays LPS-induced gene expression in human monocytes. • Expression of important monocyte effector molecules is affected by lactic acid. • Interference of lactic acid with TLR signaling causes the delayed gene expression. • The profound effect of lactic acid might contribute to immune suppression in tumors

  17. Isolation and screening of lactic acid bacteria, Lactococcus lactis ...

    In aquaculture probiotic feeding could play a crucial role in developing microbial control strategies, since disease outbreaks are recognized as important constraints to aquaculture production and the fear of antibiotic resistance. In this study, lactic acid bacteria (LAB) strains from the intestinal tissue of African catfish Clarias ...

  18. Systems solutions by lactic acid bacteria: from paradigms to practice

    Vos, de W.M.

    2011-01-01

    Lactic acid bacteria are among the powerhouses of the food industry, colonize the surfaces of plants and animals, and contribute to our health and well-being. The genomic characterization of LAB has rocketed and presently over 100 complete or nearly complete genomes are available, many of which

  19. Thermal properties of poly (lactic acid)/milkweed composites

    Currently, most polymer composites utilize petroleum-based materials that are non-degradable and difficult to recycle or incur substantial cost for disposal. Green composites can be used in nondurable limited applications. In order to determine the degree of compatibility between Poly (lactic Acid...

  20. Lactic Acid Bacteria Differentially Activate Natural Killer Cells

    Fink, Lisbeth Nielsen; Christensen, Hanne Risager; Frøkiær, Hanne

    antigen presenting cells and T-cells. Bacteria translocating across the gastrointestinal mucosa are presumed to gain access to NK cell compartments, as consumption of certain strains of lactic acid bacteria has been shown to increase in vivo NK cytotoxic activity. On-going research in our lab aims...

  1. Identification of exopolysaccharides-producing lactic acid bacteria ...

    Spacer region between 16S and 23 S rRNA genes of thirteen lactic acid bacteria strains from Burkina Faso fermented milk samples were amplified by the polymerase chain reaction (PCR). Lactobacillus delbrueckii, Lactobacillus acidophilus, Lactobacillus fermentum, Streptococcus thermophilus, Pediococcus spp, ...

  2. Heme and menaquinone induced electron transport in lactic acid bacteria

    Santos Filipe

    2009-05-01

    Full Text Available Abstract Background For some lactic acid bacteria higher biomass production as a result of aerobic respiration has been reported upon supplementation with heme and menaquinone. In this report, we have studied a large number of species among lactic acid bacteria for the existence of this trait. Results Heme- (and menaquinone stimulated aerobic growth was observed for several species and genera of lactic acid bacteria. These include Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacilllus brevis, Lactobacillus paralimentarius, Streptococcus entericus and Lactococcus garviae. The increased biomass production without further acidification, which are respiration associated traits, are suitable for high-throughput screening as demonstrated by the screening of 8000 Lactococcus lactis insertion mutants. Respiration-negative insertion-mutants were found with noxA, bd-type cytochrome and menaquinol biosynthesis gene-disruptions. Phenotypic screening and in silico genome analysis suggest that respiration can be considered characteristic for certain species. Conclusion We propose that the cyd-genes were present in the common ancestor of lactic acid bacteria, and that multiple gene-loss events best explains the observed distribution of these genes among the species.

  3. Synthesis of copolymer from lactic acid-polyethylene terephthalate ...

    Bio-plastic has been a need of the hour for the past few decades and the usage of lactic acid (LA) in the production of bio plastic opens a new ... of the environment and also helping in the production of bio-degradable plastics in the run.

  4. Lactic acid bacteria in a changing legislative environment

    Feord, J.

    2002-01-01

    The benefits of using lactic acid bacteria in the food chain, both through direct consumption and production of ingredients, are increasingly recognised by the food industry and consumers alike. The regulatory environment surrounding these products is diverse, covering foods and food ingredients,

  5. Evaluation of the probiotic potential of lactic acid bacteria isolated ...

    The probiotic-related characteristics of 55 strains of lactic acid bacteria isolated from the faeces of 3 - 6 months old breast-fed infants were determined. The API 50 CH and SDS-PAGE techniques were employed to ascertain the identity of the isolated strains. The predominant species among the isolated strains were ...

  6. GAS PERMEATION PROPERTIES OF POLY(LACTIC ACID). (R826733)

    AbstractThe need for the development of polymeric materials based on renewable resources has led to the development of poly(lactic acid) (PLA) which is being produced from a feedstock of corn rather than petroleum. The present study examines the permeation of nitrogen...

  7. Integrated production of lactic acid and biomass on distillery stillage.

    Djukić-Vuković, Aleksandra P; Mojović, Ljiljana V; Vukašinović-Sekulić, Maja S; Nikolić, Svetlana B; Pejin, Jelena D

    2013-09-01

    The possibilities of parallel lactic acid and biomass production in batch and fed-batch fermentation on distillery stillage from bioethanol production were studied. The highest lactic acid yield and productivity of 92.3 % and 1.49 g L(-1) h(-1) were achieved in batch fermentation with initial sugar concentration of 55 g L(-1). A significant improvement of the process was achieved in fed-batch fermentation where the concentration of lactic acid was increased to 47.6 % and volumetric productivity for 21 % over the batch process. A high number of Lactobacillus rhamnosus ATCC 7469 viable cells of 10(9) CFU ml(-1) was attained at the end of fed-batch fermentation. The survival of 92.9 % of L. rhamnosus cells after 3 h of incubation at pH 2.5 validated that the fermentation media remained after lactic acid removal could be used as a biomass-enriched animal feed thus making an additional value to the process.

  8. Effects of supplementing lactic acid bacteria on fecal microbiota ...

    Results: The results indicated that Lactobacillus plantarum strain L.p X3-2B increased fecal lactic acid bacteria(LAB) and Bifidobacterium while resisting the growth of harmful bacteria. Viable counts of LAB and Bifidobacterium reached 8 log cfu/mL after feeding for 14 days. Fecal pH in the control group was high in ...

  9. original article antimicrobial susceptibility pattern of lactic acid

    User

    Abstract. Currently, the efficacies of antimicrobials have been threatened due to the development of resistance to antibiotics by some microorganisms. Lactic acid bacteria (LAB) from fermented products, may act as reservoir of antimicrobial resistance-genes that could be transferred to pathogens, either in the food matrix or ...

  10. Antibacterial Activity of Lactic Acid Bacteria Isolated from Healthy ...

    Abstract. Lactic acid bacteria (LAB), namely, Lactobacillus acidophilus 1, Lactobacillus acidophilus 2, Lactobacillus brevis 1, Lactobacillus rhamnosus 1, Lactococcus lactis subsp. lactis 1, Lactococcus lactis subsp. lactis 2, Lactococcus raffinolactis 1, Pediococcus acidilactici 1, Pediococcus pentosaceus 1, and Pediococcus ...

  11. Differentiation studies of predominant lactic acid bacteria isolated ...

    Twelve isolates known as weakly amylolytic lactic acid bacteria were isolated from different time during growol fermentation, a cassava based product from Indonesia. Differentiation tests of these strains were performed using molecular and phenotypic characterization. 16S subunit of the ribosomal RNA and phenylalanyl ...

  12. Biomechanical comparison of osteosynthesis with poly‑L‑lactic acid ...

    Background and Aims: The aim of this study was to compare the biomechanical stability of poly‑L‑lactic acid and titanium screws in the fixation of intracapsular condylar fractures, in 10 polyurethane hemimandibles. Materials and Methods: Artificial intracapsular fractures were created with a steel disk and electronic ...

  13. Time related total lactic acid bacteria population diversity and ...

    The total lactic acid bacterial community involved in the spontaneous fermentation of malted cowpea fortified cereal weaning food was investigated by phenotypically and cultivation independent method. A total of 74 out of the isolated 178 strains were Lactobacillus plantarum, 32 were Pediococcus acidilactici and over 60% ...

  14. Antifungal Capacity of Lactic Acid Bacteria Isolated From Salad ...

    This study explores the use of lactic acid bacteria from fresh salad vegetables to inhibit fungal growth. The antifungal assay was done using the agar well diffusion method as reported by Schillinger and Lucke (1989). The largest zone of inhibition (25mm) was recorded by the antagonistic activity of the isolate identified to ...

  15. Controlled overproduction of proteins by lactic acid bacteria

    Kuipers, Oscar P.; Ruyter, Pascalle G.G.A. de; Kleerebezem, Michiel; Vos, Willem M. de

    1997-01-01

    Lactic acid bacteria are widely used in industrial food fermentations, contributing to flavour, texture and preservation of the fermented products. Here we describe recent advances in the development of controlled gene expression systems, which allow the regulated overproduction of any desirable

  16. Heme and menaquinone induced electron transport in lactic acid bacteria.

    Brooijmans, Rob; Smit, Bart; Santos, Filipe; van Riel, Jan; de Vos, Willem M; Hugenholtz, Jeroen

    2009-05-29

    For some lactic acid bacteria higher biomass production as a result of aerobic respiration has been reported upon supplementation with heme and menaquinone. In this report, we have studied a large number of species among lactic acid bacteria for the existence of this trait. Heme- (and menaquinone) stimulated aerobic growth was observed for several species and genera of lactic acid bacteria. These include Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacilllus brevis, Lactobacillus paralimentarius, Streptococcus entericus and Lactococcus garviae. The increased biomass production without further acidification, which are respiration associated traits, are suitable for high-throughput screening as demonstrated by the screening of 8000 Lactococcus lactis insertion mutants. Respiration-negative insertion-mutants were found with noxA, bd-type cytochrome and menaquinol biosynthesis gene-disruptions. Phenotypic screening and in silico genome analysis suggest that respiration can be considered characteristic for certain species. We propose that the cyd-genes were present in the common ancestor of lactic acid bacteria, and that multiple gene-loss events best explains the observed distribution of these genes among the species.

  17. Statistical optimization of lactic acid production by Lactococcus lactis ...

    The individual and interactive effects of a total inoculums size (% v/v), fermentation temperature and skim milk dry matter added (% w/v) on the lactic acid production by Lactococcus lactis LCL strain were studied by quadratic response surface methodology. The central composite design (CCD) was employed to determine ...

  18. Antibacterial activity and probiotic properties of some lactic acid ...

    Several lactic acid bacteria strains were screened for the production of antibacterial substances active against some pathogenic bacteria. The inhibitory mechanism was investigated and was shown to be dependant of bacteriocin production. The objective was to isolate LAB with antibacterial activity from raib and to select ...

  19. Repressive efficacy of lactic acid bacteria against the human ...

    Different strains of lactic acid bacteria (LAB) namely Lactobacillus acidophilus NCIM 2287, Lactobacillus plantarum NCIM 2085, Lactobacillus helveticus NCIM 2126 and Lactococcus lactis NCIM 2114 were procured from the National Chemical Laboratory (NCL) Pune, India. These LAB cells were individually (107 cfu/ml) ...

  20. Antibacterial Activities of Lactic Acid Bacteria Isolated from Selected ...

    Members of lactic acid bacteria (LAB) are known probiotics and have been reported to have antimicrobial properties. Although various researchers have documented the isolation of these bacteria from fruits and vegetables, studies on LAB associated with lettuce, cucumber and cabbage are limited and non-existing in ...

  1. Inhibition of aflatoxin-producing aspergilli by lactic acid bacteria ...

    A total of six lactic acid bacteria (LAB) isolates were selected from five indigenously fermented cereal gruels and identified as Lactobacillus fermentum OYB, Lb. fermentum RS2, Lb. plantarum MW, Lb. plantarum YO, Lb. brevis WS3, and Lactococcus spp. RS3. Six aflatoxin-producing aspergilli were also selected from the ...

  2. Bacteriocin and cellulose production by lactic acid bacteria isolated ...

    Sixteen colonies of lactic acid bacteria (LAB) were selected and screened for their ability to produce bacteriocin by agar well diffusion method using the supernatant of centrifuged test cultures. Four isolates inhibited the growth of Listeria monocytogenes and Escherichia coli. Lactobacillus plantarum (6) and Lactobacillus ...

  3. Electrospinnability of poly lactic-co-glycolic acid (PLGA)

    Liu, Xiaoli; Baldursdottir, Stefania G.; Aho, Johanna

    2017-01-01

    PURPOSE: In this study, the electrospinnability of poly(lactic-co-glycolic acid) (PLGA) solutions was investigated, with a focus on understanding the influence of molecular weight of PLGA, solvent type and solvent composition on the physical properties of electrospun nanofibers. METHOD: Various s...

  4. Lactic acid and Lactates in Health and wellness

    Gertjan Schaafsma; Victor Schreurs

    2010-01-01

    This review aims to integrate the present state of knowledge on lactate metabolism in human and mammalian physiology as far as it could be subject to nutritional interventions. An integrated view on the nutritional, metabolic and physiological aspects of lactic acid and lactates might open a

  5. Kinetics and adsorption isotherm of lactic acid from fermentation broth onto activated charcoal

    Seankham Soraya

    2017-01-01

    Full Text Available Activated charcoal was applied for the recovery of lactic acid in undissociated form from fermentation broth. Lactic acid was obtained from the fermentation of Lactobacillus casei TISTR 1340 using acid hydrolyzed Jerusalem artichoke as a carbon source. The equilibrium adsorption isotherm and kinetics for the lactic acid separation were investigated. The experimental data for lactic acid adsorption from fermentation broth were best described by the Freundlich isotherm and the pseudo-second order kinetics with R2 values of 0.99. The initial adsorption rate was 41.32 mg/g⋅min at the initial lactic acid concentration of 40 g/L.

  6. Chirality Matters: Synthesis and Consumption of the d-Enantiomer of Lactic Acid by Synechocystis sp. Strain PCC6803

    Angermayr, S.A.; van der Woude, A.D.; Correddu, D.; Kern, R.; Hagemann, M.; Hellingwerf, K.J.

    2015-01-01

    Both enantiomers of lactic acid, l-lactic acid and d-lactic acid, can be produced in a sustainable way by a photosynthetic microbial cell factory and thus from CO2, sunlight, and water. Several properties of polylactic acid (a polyester of polymerized lactic acid) depend on the controlled blend of

  7. pH-, Lactic Acid-, and Non-Lactic Acid-Dependent Activities of Probiotic Lactobacilli against Salmonella enterica Serovar Typhimurium

    Fayol-Messaoudi, Domitille; Berger, Cédric N.; Coconnier-Polter, Marie-Hélène; Liévin-Le Moal, Vanessa; Servin, Alain L.

    2005-01-01

    The mechanism(s) underlying the antibacterial activity of probiotic Lactobacillus strains appears to be multifactorial and includes lowering of the pH and the production of lactic acid and of antibacterial compounds, including bacteriocins and nonbacteriocin, non-lactic acid molecules. Addition of Dulbecco's modified Eagle's minimum essential medium to the incubating medium delays the killing activity of lactic acid. We found that the probiotic strains Lactobacillus johnsonii La1, Lactobacill...

  8. Availability of lignocellulosic feedstocks for lactic acid production - Feedstock availability, lactic acid production potential and selection criteria

    Bakker, R.R.C.

    2013-01-01

    The overall objective of this study is to assess the worldwide availability and suitability of agricultural residues for lactic acid production, based on fermentation of carbohydrates. The study focuses on lignocellulosic biomass that is produced as a by-product of agricultural production. The

  9. Production of fermented probiotic beverages from milk permeate enriched with whey retentate and identification of present lactic acid bacteria

    Jagoda Šušković

    2009-03-01

    Full Text Available In this research the application of bacterial strains Lactobacillus acidophilus M92, Lactobacillus plantarum L4 and Enterococcus faecium L3 in the production of fermented probiotic beverages from milk permeate enriched with 10 % (v/v whey retentate, was investigated. In the previous researches of probiotic concept, probiotic properties of these three strains of lactic acid bacteria have been defined. At the end of controlled fermentation, probiotic strains have produced 7.4 g/L lactic acid, pH was decreased to 4.7, and number of live cells was around 108 CFU/mL. Number of viable count of probiotic bacteria, which were identified with RAPD (Random Amplified Polymorphic DNAmethod, was maintained at around 107 CFU/mL during 28 days of the preservation at 4 °C. Furthermore, a spontaneous fermentation of milk permeate enriched with 10 % (v/v of whey retentate was carried out and lactic acid bacteria present in these substrates were isolated. All of these bacterial strains have rapidly acidified the growth media and have shown antibacterial activity against chosen test-microorganisms, what are important properties of potential starter cultures for the fermentation of dairy products. The results of biochemical API analysis have identified isolated strains as Lactococcus lactis subsp. lactis and Lactobacillus helveticus.

  10. From local strains to specific starters: the process structuring a research program on the activation and management of a biotechnological resource

    Casalta, Erick; Bona, Pascale

    2009-01-01

    This study presents a research-action program carried out in Corsica with a group of cheese makers to develop specific starters. Based on the direct participation of the cheese makers, this study consisted in designing starters with lactic acid bacterial strains isolated from milks and cheeses of this group of cheese makers. This process modified an individually and empirically used resource, local strains, into a shared and collectively managed resource, specific starters. Patrimonial featur...

  11. Stress response assessment of Lactobacillus sakei strains selected as potential autochthonous starter cultures by flow cytometry and nucleic acid double-staining analyses.

    Bonomo, M G; Milella, L; Martelli, G; Salzano, G

    2013-09-01

    The aim of this study was to apply the flow cytometry to Lactobacillus sakei strains, selected as potential autochthonous starters, to investigate dynamics and physiological heterogeneity of microbial behaviour under different stress conditions. A simultaneous nucleic acid double-staining assay was applied to discriminate cell populations in different physiological states after exposure to heat (50 and 55°C) and acid (pH 2·5 and 3·0) stresses. Alive cells with intact membranes, damaged cells still alive but with injured membranes, so with even a recovery ability, and dead cells with a permanent membrane damage were differentiated with a significant increase in damaged cells after stronger stress treatments. The existence and characteristics of subpopulations displaying heterogeneity in particular conditions are highly relevant, because specific subpopulations may show improved survival, changes and dynamics under stress conditions. This assay has potential for physiological research on lactic acid bacteria and for application in the food industry. The assessment of intermediate physiological states in Lb. sakei strains with recovery possibility could be an important criterion for application of potential starter cultures. Application of flow cytometry and characterization of sorted subpopulations may contribute to further understanding of diversity and heterogeneity in physiology of bacterial populations. © 2013 The Society for Applied Microbiology.

  12. Lactic Acid Yield Using Different Bacterial Strains, Its Purification, and Polymerization through Ring-Opening Reactions

    F. G. Orozco

    2014-01-01

    Full Text Available Laboratory-scale anaerobic fermentation was performed to obtain lactic acid from lactose, using five lactic acid bacteria: Lactococcus lactis, Lactobacillus bulgaricus, L. delbrueckii, L. plantarum, and L. delbrueckii lactis. A yield of 0.99 g lactic acid/g lactose was obtained with L. delbrueckii, from which a final concentration of 80.95 g/L aqueous solution was obtained through microfiltration, nanofiltration, and inverse osmosis membranes. The lactic acid was polymerized by means of ring-opening reactions (ROP to obtain poly-DL-lactic acid (PDLLA, with a viscosity average molecular weight (Mv of 19,264 g/mol.

  13. Enhanced L-(+)-lactic acid production by an adapted strain of Rhizopus oryzae using corncob hydrolysate

    Bai, Dongmei; Li, S.Z.; Liu, Z.L.

    2008-01-01

    -added production of a variety of bioproducts. Lactic acid can be used as a precursor for poly-lactic acid production. Although current industrial lactic acid is produced by lactic acid bacteria using enriched medium, production by Rhizopus oryzae is preferred due to its exclusive formation of the......-isomer and a simple nutrition requirement by the fungus. Production of-L-(+)-lactic acid by R. oryzae using xylose has been reported; however, its yield and conversion rate are poor compared with that of using glucose. In this study, we report an adapted R. oryzae strain HZS6 that significantly improved efficiency...... of substrate utilization and enhanced production of L-(+)-lactic acid from corncob hydrolysate. It increased L-(+)-lactic acid final concentration, yield, and volumetric productivity more than twofold compared with its parental strain. The optimized growth and fermentation conditions for Strain HZS6 were...

  14. Lactic acid peeling in superficial acne scarring in Indian skin.

    Sachdeva, Silonie

    2010-09-01

    Chemical peeling with both alpha and beta hydroxy acids has been used to improve acne scarring with pigmentation. Lactic acid, a mild alpha hydroxy acid, has been used in the treatment of various dermatological indications but no study is reported in acne scarring with pigmentation. To evaluate the efficacy and safety of full strength pure lactic acid 92% (pH 2.0) chemical peel in superficial acne scarring in Indian skin. Seven patients, Fitzpatrick skin type IV-V, in age group 20-30 years with superficial acne scarring were enrolled in the study. Chemical peeling was done with lactic acid at an interval of 2 weeks to a maximum of four peels. Pre- and post-peel clinical photographs were taken at every session. Patients were followed every month for 3 months after the last peel to evaluate the effects. At the end of 3 months, there was definite improvement in the texture, pigmentation, and appearance of the treated skin, with lightening of scars. Significant improvement (greater than 75% clearance of lesions) occurred in one patient (14.28%), good improvement (51-75% clearance) in three patients (42.84%), moderate improvement (26-50% clearance) in two patients (28.57%), and mild improvement (1-25% clearance) in one patient (14.28%). © 2010 Wiley Periodicals, Inc.

  15. Exploring the Microbiota of Faba Bean: Functional Characterization of Lactic Acid Bacteria

    Michela Verni

    2017-12-01

    Full Text Available 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.

  16. Predominant lactic acid bacteria associated with the traditional malting of sorghum grains

    Sawadogo-Lingani, H.; Diawara, B.; Glover, R.K.

    2010-01-01

    dominated the microbiota from sorghum grains to malted sorghum. These isolates had technological properties comparable to those responsible for the acidification of sorghum beer (dolo, pito) wort produced from sorghum malt (previously studied), suggesting their potential for use as starter cultures....... Suitable isolates of L. fermentum are promising candidates to be used as starter cultures from the initial step of malting, that is, the steeping and are expected to inhibit the growth and survival of pathogens and spoilage microflora, and to control the lactic fermentation of dolo and pito wort or other...

  17. Accelerated fatigue of dentin with exposure to lactic acid.

    Do, D; Orrego, S; Majd, H; Ryou, H; Mutluay, M M; Xu, Hockin H K; Arola, D

    2013-11-01

    Composite restorations accumulate more biofilm than other dental materials. This increases the likelihood for the hard tissues supporting a restoration (i.e. dentin and enamel) to be exposed to acidic conditions beyond that resulting from dietary variations. In this investigation the fatigue strength and fatigue crack growth resistance of human coronal dentin were characterized within a lactic acid solution (with pH = 5) and compared to that of controls evaluated in neutral conditions (pH = 7). A comparison of the fatigue life distributions showed that the lactic acid exposure resulted in a significant reduction in the fatigue strength (p ≤ 0.001), and nearly 30% reduction in the apparent endurance limit (from 44 MPa to 32 MPa). The reduction in pH also caused a significant decrease (p ≤ 0.05) in the threshold stress intensity range required for the initiation of cyclic crack growth, and significant increase in the incremental rate of crack extension. Exposure of tooth structure to lactic acid may cause demineralization, but it also increases the likelihood of restored tooth failures via fatigue, and after short time periods. © 2013 Elsevier Ltd. All rights reserved.

  18. Kinetics of β-galactosidase Production by Lactobacillus bulgaricus During pH Controlled Batch Fermentation in Three Commercial Bulk Starter Media

    Saeed Abbasalizadeh

    2015-10-01

    Full Text Available The potential of bulk starter fermentation strategy for production of a cost-effective and GRAS source of β-galactosidase from a starter culture strain Lactobacillus bulgaricus was investigated. Three different media were selected and the strain, L. bulgaricus DSM 20081 was cultivated in these media under pH-controlled condition (pH = 5.6 at 43°C. The media were: bulk starter medium based on skim milk + whey, bulk starter medium based on whey, and skim milk. Growth and β-lactic acid production parameters were estimated from experimental data with the Garcia and Luedeking-Piret models, respectively. β-galactosidase production kinetics was also simulated using models based on biomass concentration and lactic acid production. Growth in the bulk starter medium based on skim milk + whey resulted in a higher rate of lactic acid production (7.35 ± 0.23  mg lactic acid ml-1 media h-1 and β-galactosidase activity (800.1± 0.7 nmol ONP ml-1 media compared to the other two media (P<0.01. Simulation of β- galactosidase production based on rate of lactic acid production resulted in very good agreement with experimental data for all three tested media. The results revealed the potential of bulk starter fermentation strategy and skim milk + whey based medium for in-house and relatively low cost production of food-grade β-galactosidase by dairy plants.

  19. DNA fingerprinting of lactic acid bacteria in sauerkraut fermentations.

    Plengvidhya, Vethachai; Breidt, Fredrick; Lu, Zhongjing; Fleming, Henry P

    2007-12-01

    Previous studies using traditional biochemical identification methods to study the ecology of commercial sauerkraut fermentations revealed that four species of lactic acid bacteria, Leuconostoc mesenteroides, Lactobacillus plantarum, Pediococcus pentosaceus, and Lactobacillus brevis, were the primary microorganisms in these fermentations. In this study, 686 isolates were collected from four commercial fermentations and analyzed by DNA fingerprinting. The results indicate that the species of lactic acid bacteria present in sauerkraut fermentations are more diverse than previously reported and include Leuconostoc citreum, Leuconostoc argentinum, Lactobacillus paraplantarum, Lactobacillus coryniformis, and Weissella sp. The newly identified species Leuconostoc fallax was also found. Unexpectedly, only two isolates of P. pentosaceus and 15 isolates of L. brevis were recovered during this study. A better understanding of the microbiota may aid in the development of low-salt fermentations, which may have altered microflora and altered sensory characteristics.

  20. Radiation induced crystallinity damage in poly(L-lactic acid)

    Kantoglu, O

    2002-01-01

    The radiation-induced crystallinity damage in poly(L-lactic acid) (PLLA) in the presence of air and in vacuum, is studied. From the heat of fusion enthalpy values of gamma irradiated samples, some changes on the thermal properties were determined. To identify these changes, first the glass transition temperature (T sub g) of L-lactic acid polymers irradiated to various doses in air and vacuum have been investigated and it is found that it is independent of irradiation atmosphere and dose. The fraction of damaged units of PLLA per unit of absorbed energy has been measured. For this purpose, SAXS and differential scanning calorimetry methods were used, and the radiation yield of number of damaged units (G(-u)) is found to be 0.74 and 0.58 for PLLA samples irradiated in vacuum and air, respectively.

  1. Potential Use of Gelidium amansii Acid Hydrolysate for Lactic Acid Production by Lactobacillus rhamnosus

    Sung-Soo Jang

    2013-01-01

    Full Text Available Galactose and glucose are the main monosaccharides produced from the saccharification of Gelidium amansii. They were hydrolysed with 3 % (by volume H2SO4 at 140 °C for 5 min and obtained at concentrations of 19.60 and 10.21 g/L, respectively. G. amansii hydrolysate (5 %, by mass per volume was used as a substrate for L(+-lactic acid production by Lactobacillus rhamnosus. The maximum lactic acid yield (YP/S was 42.03 % with optical purity of 84.54 %. Lactic acid produced from G. amansii hydrolysate can be applicable, among others, for the production of lactic acid esters, like ethyl or methyl lactate, and disinfectant in seaweed cultivation.

  2. Isolation and Characterization of Lactic Acid Bacteria from Inasua

    Ferymon Mahulette

    2017-04-01

    Full Text Available Inasua is a traditionally product of wet salt fish fermentation produced by Teon, Nila and Serua (TNS Communities in Central Maluku, Indonesia. The community made this fermented fish to anticipate the lean time when fisherman could not go to sea.  The  fish that used as inasua raw material is demersal fishes that live around coral reefs, such as Samandar fish (Siganatus guttatus, Gala-gala fish (Lutjanus sp. and Sikuda fish (Lethrinus ornatus. The objective of the research was to isolate and characterize of bacterial indigenous in  Inasua from three producers in Seram Island. The measurement of pH from inasua samples were 5.9, 5.0 and 5.8, respectively. The highest number of lactic acid bacteria was found from  Gala – gala inasua was 2,5x107 cfu/g sample. Isolation of all isolates bacteria from inasua showed that a total of 7 isolates of bacteria was obtained  from Samadar inasua, 9 isolates from  Gala-gala inasua, and 7 isolates from  Sikuda inasua.  From a total of 23 isolates, only 6 isolates had characteristic as lactic acid bacteria that were Gram  positive, negative catalase, and cocci shape. The microscopic characteristics  of the isolates are coccid in pairs or uniforms which combine to form tetrads. Carbohydrate utilization test  of selected isolate by using API 50 CHB kit indicated that 13 carbohydrates are fermented by these isolates  after incubation for 48 hours. The research  was concluded that the dominant bacteria in inasua sample  is  cocci-lactic acid bacteria. Keywords : fermented fish, inasua, lactic acid bacteria, MRSA medium

  3. Lactic Acid Bacteria in Health and Disease

    Prevention of antibiotic associated diarrhoea, reduction in lactose intolerance, production of conjugated linoliec acid ..... Factor (TGF)-β2 in the breast milk of probiotic treated mothers ..... in amacunda than in ghee because heat clarification of.

  4. RECOVERY OF LACTIC ACID FROM AMERICAN CRYSTAL SUGAR COMPANY WASTEWATER

    Daniel J. Stepan; Edwin S. Olson; Richard E. Shockey; Bradley G. Stevens; John R. Gallagher

    2001-04-30

    This project has shown that the recovery of several valuable lactic acid products is both technically feasible and economically viable. One of the original objectives of this project was to recover lactic acid. However, the presence of a variety of indigenous bacteria in the wastewater stream and technical issues related to recovery and purification have resulted in the production of lactic acid esters. These esters could by hydrolyzed to lactic acid, but only with unacceptable product losses that would be economically prohibitive. The developed process is projected to produce approximately 200,000 lb per day of lactate esters from wastewater at a single factory at costs that compete with conventional solvents. The lactate esters are good solvents for polymers and resins and could replace acetone, methyl ethyl ketone, MIBK, and other polar solvents used in the polymer industry. Because of their low volatility and viscosity-lowering properties, they will be especially useful for inks for jet printers, alkyl resins, and high-solid paints. Owing to their efficiency in dissolving salts and flux as well as oils and sealants, lactate esters can be used in cleaning circuit boards and machine and engine parts. Unlike conventional solvents, lactate esters exhibit low toxicity, are biodegradable, and are not hazardous air pollutants. Another application for lactate esters is in the production of plasticizers. Severe health problems have been attributed to widely used phthalate ester plasticizers. The U.S. Department of Agriculture showed that replacement of these with inexpensive lactate esters is feasible, owing to their superior polymer compatibility properties. A very large market is projected for polymers prepared from lactic acid. These are called polylactides and are a type of polyester. Thermoplastics of this type have a variety of uses, including moldings, fibers, films, and packaging of both manufactured goods and food products. Polylactides form tough, orientable

  5. Bioconversion of renewable resources into lactic acid: an industrial view.

    Yadav, A K; Chaudhari, A B; Kothari, R M

    2011-03-01

    Lactic acid, an anaerobic product of glycolysis, can be theoretically produced by synthetic route; however, it is commercially produced by homo-fermentative batch mode of operations. Factors affecting its production and strategies improving it are considered while devising an optimized protocol. Although a hetero-fermentative mode of production exists, it is rarely used for commercial production. Attempts to use Rhizopus sp. for lactic acid production through either hetero-fermentative or thermophilic conditions were not economical. Since almost 70% of the cost of its production is accounted by raw materials, R & D efforts are still focused to find economically attractive agri-products to serve as sources of carbon and complex nitrogen inputs to meet fastidious nutrient needs for microbial growth and lactic acid production. Therefore, need exists for using multi-pronged strategies for higher productivity. Its present production and consumption scenario is examined. Its optically active isomers and chemical structure permit its use for the production of several industrially important chemicals, health products (probiotics), food preservatives, and bio-plastics. In addition, its salts and esters appear to have a variety of applications.

  6. Dynamic modeling of lactic acid fermentation metabolism with Lactococcus lactis.

    Oh, Euhlim; Lu, Mingshou; Park, Changhun; Park, Changhun; Oh, Han Bin; Lee, Sang Yup; Lee, Jinwon

    2011-02-01

    A dynamic model of lactic acid fermentation using Lactococcus lactis was constructed, and a metabolic flux analysis (MFA) and metabolic control analysis (MCA) were performed to reveal an intensive metabolic understanding of lactic acid bacteria (LAB). The parameter estimation was conducted with COPASI software to construct a more accurate metabolic model. The experimental data used in the parameter estimation were obtained from an LC-MS/ MS analysis and time-course simulation study. The MFA results were a reasonable explanation of the experimental data. Through the parameter estimation, the metabolic system of lactic acid bacteria can be thoroughly understood through comparisons with the original parameters. The coefficients derived from the MCA indicated that the reaction rate of L-lactate dehydrogenase was activated by fructose 1,6-bisphosphate and pyruvate, and pyruvate appeared to be a stronger activator of L-lactate dehydrogenase than fructose 1,6-bisphosphate. Additionally, pyruvate acted as an inhibitor to pyruvate kinase and the phosphotransferase system. Glucose 6-phosphate and phosphoenolpyruvate showed activation effects on pyruvate kinase. Hexose transporter was the strongest effector on the flux through L-lactate dehydrogenase. The concentration control coefficient (CCC) showed similar results to the flux control coefficient (FCC).

  7. Technology and economic assessment of lactic acid production and uses

    Datta, R.; Tsai, S.P.

    1996-03-01

    Lactic acid has been an intermediate-volume specialty chemical (world production {approximately}50,000 tons/yr) used in a wide range of food-processing and industrial applications. Potentially, it can become a very large-volume, commodity-chemical intermediate produced from carbohydrates for feedstocks of biodegradable polymers, oxygenated chemicals, environmentally friendly ``green`` solvents, and other intermediates. In the past, efficient and economical technologies for the recovery and purification of lactic acid from fermentation broths and its conversion to the chemical or polymer intermediates had been the key technology impediments and main process cost centers. Development and deployment of novel separations technologies, such as electrodialysis with bipolar membranes, extractive and catalytic distillations, and chemical conversion, can enable low-cost production with continuous processes in large-scale operations. The emerging technologies can use environmentally sound lactic acid processes to produce environmentally useful products, with attractive process economics. These technology advances and recent product and process commercialization strategies are reviewed and assessed.

  8. Study of Lactic Acid Thermal Behavior Using Thermoanalytical Techniques

    Andrea Komesu

    2017-01-01

    Full Text Available Actually, there is a growing interest in the biotechnological production of lactic acid by fermentation aiming to substitute fossil fuel routes. The development of an efficient method for its separation and purification from fermentation broth is very important to assure the economic viability of production. Due to its high reactivity and tendency to decompose at high temperatures, the study of lactic acid thermal behavior is essential for its separation processes and potential application. In the present study, differential scanning calorimetry (DSC analyses showed endothermic peaks related to the process of evaporation. Data of thermogravimetry (TG/DTG were correlated to Arrhenius and Kissinger equations to provide the evaporation kinetic parameters and used to determine the vaporization enthalpy. Activation energies were 51.08 and 48.37 kJ·mol−1 and frequency values were 859.97 and 968.81 s−1 obtained by Arrhenius and Kissinger equations, respectively. Thermogravimetry, coupled with mass spectroscopy (TG-MS, provided useful information about decomposition products when lactic acid was heated at 573 K for approximately 30 min.

  9. Lactic acid bacteria as a cell factory for riboflavin production.

    Thakur, Kiran; Tomar, Sudhir Kumar; De, Sachinandan

    2016-07-01

    Consumers are increasingly becoming aware of their health and nutritional requirements, and in this context, vitamins produced in situ by microbes may suit their needs and expectations. B groups vitamins are essential components of cellular metabolism and among them riboflavin is one of the vital vitamins required by bacteria, plants, animals and humans. Here, we focus on the importance of microbial production of riboflavin over chemical synthesis. In addition, genetic abilities for riboflavin biosynthesis by lactic acid bacteria are discussed. Genetically modified strains by employing genetic engineering and chemical analogues have been developed to enhance riboflavin production. The present review attempts to collect the currently available information on riboflavin production by microbes in general, while placing greater emphasis on food grade lactic acid bacteria and human gut commensals. For designing riboflavin-enriched functional foods, proper selection and exploitation of riboflavin-producing lactic acid bacteria is essential. Moreover, eliminating the in situ vitamin fortification step will decrease the cost of food production. © 2015 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  10. Salt-inducible promoter derivable from a lactic acid bacterium, and its use in a lactic acid bacterium for production of a desired protein

    Sanders, Jan Willem; Kok, Jan; Venema, Gerard; Ledeboer, Adrianus Marinus

    1998-01-01

    The invention provides a salt-inducible promoter present in SEQ ID NO: 10 and derivable from a lactic acid bacterium in isolation from the coding sequence normally controlled by said promoter in a wild-type lactic acid bacterium, with modifications and important parts thereof. Also provided are a

  11. Characterization of lactic acid bacteria from musts and wines of three consecutive vintages of Ribeira Sacra.

    Mesas, J M; Rodríguez, M C; Alegre, M T

    2011-03-01

    This study was designed to isolate and characterize the lactic acid microbiota of the musts and wines of a young denomination of origin area, Ribeira Sacra in north-west Spain. Over three consecutive years (2007, 2008 and 2009), we examined musts and wines from four cellars in different zones of the region. Through biochemical and genetic tests, 459 isolates of lactic acid bacteria (LAB) were identified as the following species: Lactobacillus alvei (0·7%), Lactobacillus brevis (1·7%), Lactobacillus frumenti (0·9%), Lactobacillus kunkeei (12%), Lactobacillus plantarum (6·5%), Lactobacillus pentosus (0·9%), Lactococcus lactis ssp. lactis (3%), Leuconostoc citreum (0·7%), Leuconostoc fructosum (synon. Lactobacillus fructosum) (3·7%), Leuconostoc mesenteroides ssp. mesenteroides (2·8%), Leuconostoc pseudomesenteroides (0·2%), Oenococcus oeni (59%), Pediococcus parvulus (7%) and Weisella paramesenteroides (synon. Leuconostoc paramesenteroides) (0·9%). Of these species, O. oeni was the main one responsible for malolactic fermentation (MLF) in all cellars and years with the exception of Lact. plantarum, predominant in 2007, in one cellar, and Lact. brevis, Lact. frumenti and Ped. parvulus coexisting with O. oeni in one cellar in 2009. Different strains (84) of LAB species (14) were identified by biochemical techniques (API strips, the presence of plasmids, enzyme activities and MLF performance) and molecular techniques (PCR). All assays were carried out with every one of the 459 isolates. To select candidates for use as culture starters, we assessed malolactic, β-glucosidase and tannase activities, the presence of genes involved in biogenic amine production and plasmid content. A high diversity of LAB is present in the grape musts of Ribeira Sacra but few species are responsible for MLF; however, different strains of such species are involved in the process. As far as we are aware, this is the first report of Lact. frumenti thriving in wine. Information on LAB

  12. Antioxidant Activities of Lactic Acid Bacteria for Quality Improvement of Fermented Sausage.

    Zhang, Yulong; Hu, Ping; Lou, Lijiao; Zhan, Jianlong; Fan, Min; Li, Dan; Liao, Qianwei

    2017-12-01

    Lactobacillus curvatus (SR6) and Lactobacillus paracasei (SR10-1) were assessed for their antioxidant activities and inoculated into sausages to investigate their effects on quality during fermentation. The results showed that L. curvatus SR6 had better DPPH• scavenging activity (59.67% ± 6.68%) and reducing power (47.31% ± 4.62%) and L. paracasei SR10-1 had better OH• scavenging activity (285.67% ± 2.00%) and anti-lipid peroxidation capacity (63.89% ± 0.93%). The superoxide dismutase activity of the cell culture fluid was greater than 47.00 U/mL, and the catalase activity of the cell-free extracts was greater than 1.00 U/mL. In the sausage model, lactic acid bacteria rapidly became the dominant microflora and reduced the moisture content, water activity, nitrite, and pH. The bacteria significantly enhanced the antioxidant activity of the sausage extracts, which improved the sensory characteristics and safety of the sausages. These results illustrate that both strains have excellent antioxidant activities and can be used as antioxidant starters in fermented meat products. The study illustrated the antioxidant and antioxidase activities of Lactobacillus curvatus SR6 and Lactobacillus paracasei SR10-1 and demonstrated the changes in the quality characteristics and antioxidant activities of fermented sausages. The findings provide valuable information for the meat industry on the application of functional starters in fermented meat products. © 2017 Institute of Food Technologists®.

  13. The behavior and importance of lactic acid complexation in Talspeak extraction systems

    Grimes, Travis S.; Nilsson, Mikael; Nash, Kenneth L.

    2008-01-01

    Advanced partitioning of spent nuclear fuel in the UREX +la process relies on the TALSPEAK process for separation of fission-product lanthanides from trivalent actinides. The classic TALSPEAK utilizes an aqueous medium of both lactic acid and diethylenetriaminepentaacetic acid and the extraction reagent di(2-ethylhexyl)phosphoric acid in an aromatic diluent. In this study, the specific role of lactic acid and the complexes involved in the extraction of the trivalent actinides and lanthanides have been investigated using 14 C-labeled lactic acid. Our results show that lactic acid partitions between the phases in a complex fashion. (authors)

  14. Cultura lática mista com potencial de aplicação como cultura iniciadora em produtos cárneos Mixed lactic culture with potential application as starter culture in meat products

    Rosicler BALDUINO

    1999-12-01

    . They can be formed by pure or mixed culture that are able to produce antimicrobial substances as lactic acid and bacteriocins and to inhibit undesirable microorganisms in the food product. In this work there were evaluated various associations of lactic bacteria among Lactobacillus, Pediococcus and Enterococcus, in order to obtain lactic cultures with the biochemical ability for homolactic fermentation; high cellular viability; tolerance to the NaCl and NaNO2 salts; able to reduce nitrites and to inhibit pathogens such as S. aureus, Salmonella and E. coli. The cultures were developed in MRS medium, incubated at 37ºC for 48 hours. Lactic acid was determined by HPLC. Residual nitrite was measured by spectrophotometry. The homolactic fermentation with better lactic acid production (4.61% and higher cellular viability (3x10(15 CFU/mL were obtained by the culture constituted by L. curvatus, L. plantarum, P. acidilactici e E. faecium. The selected starter showed high cellular viability (1x10(14CFU/mL, even in high concentrations of NaCl and NaNO2. The fermented broth showed reduction (99% of initial nitrite. The selected mixed lactic acid culture inhibited S. aureus, Salmonella spp. and E. coli in BHI-agar. In fresh sausage it was observed reductions on counts of S. aureus and total coliforms were observed in fresh sausage, in relation to the controls. Salmonella spp. was not detected in the assayed samples. The results show the possibility of application of the selected mixed culture as starter culture in meat products.

  15. Evaluation of different lactic acid bacterial strains for probiotic characteristics

    B. Srinu,

    2013-08-01

    Full Text Available Objective: The objective of the present study was to collect different Lactic acid bacterial strains from culture collection centers and screen their functional probiotic characteristics such as acid tolerance, bile tolerance, antibacterial activity and antibiotic sensitivity for their commercial use. Materials and Methods: Acid and bile tolerence of selected LAB(Lactic acid bacteria was determined. The antibiotic resistance of Lactobacillus species was assessed using different antibiotic discs on de Mann Rogosa Sharpe broth (MRS agar plates seeded with the test probiotic organism. The antibacterial activity of LAB was assessed by using well diffusion method.Results: Among the six probiotic strains tested, all showed good survivability at high bile salt concentration (0.3 to 2.0 % oxgall and good growth at a low pH of 1.5 to 3.5. These probiotic species showed good survival abilities in acidic pH of 2.0 to 3.5 except Lactobacillus delbrueckii subspp. bulgaricus 281 which did not grown at pH of 2.0. Lactobacillus fermentum 141 was able to grow even at pH of 1.5 also. Among the six lactic acid species, Lactobacillus fermentum 141 (except Tetracycline, Lactobacillus delbrueckii subspp. Bulgaricus 281 except (Cefpodoxime and all other LAB were resistant to all the antibiotics tested (Ampicillin, Nalidixic acid , Ciprofloxacin ,Co-Trimoxazole, Gentamicin and Cefpodoxime. All these probiotic organisms were screened for their in vitro inhibition ability against pathogenic microorganisms namely, E.coli ATCC (American type culture collection centre, Pseudomonas aeruginosa, Salmonella paratyphi, Staphylococcus aureus. Lactobacillus delbrueckii subspp. bulgaricus 281, Lactobacillus casei 297 and Lactobacillus fermentum 141 inhibited the growth of all the pathogenic bacteria used in the study. Conclusion: The study indicated Lactobacillus fermentum 141 and Lactobacillus casei 297 as potential functional probiotics for future in vivo studies for

  16. Binding and detoxification of chlorpyrifos by lactic acid bacteria on rice straw silage fermentation.

    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.

  17. Catalytic Cracking of Lactide and Poly(Lactic Acid) to Acrylic Acid at Low Temperatures.

    Terrade, Frédéric G; van Krieken, Jan; Verkuijl, Bastiaan J V; Bouwman, Elisabeth

    2017-05-09

    Despite being a simple dehydration reaction, the industrially relevant conversion of lactic acid to acrylic acid is particularly challenging. For the first time, the catalytic cracking of lactide and poly(lactic acid) to acrylic acid under mild conditions is reported with up to 58 % yield. This transformation is catalyzed by strong acids in the presence of bromide or chloride salts and proceeds through simple S N 2 and elimination reactions. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  18. Quantitative analysis of the lactic acid and acetaldehyde produced by Streptococcus thermophilus and Lactobacillus bulgaricus strains isolated from traditional Turkish yogurts using HPLC.

    Gezginc, Y; Topcal, F; Comertpay, S; Akyol, I

    2015-03-01

    The present study was conducted to evaluate the lactic acid- and acetaldehyde-producing abilities of lactic acid bacterial species isolated from traditionally manufactured Turkish yogurts using HPLC. The lactic acid bacterial species purified from the yogurts were the 2 most widely used species in industrial yogurt production: Streptococcus thermophilus and Lactobacillus bulgaricus. These bacteria have the ability to ferment hexose sugars homofermentatively to generate lactic acid and some carbonyl compounds, such as acetaldehyde through pyruvate metabolism. The levels of the compounds produced during fermentation influence the texture and the flavor of the yogurt and are themselves influenced by the chemical composition of the milk, processing conditions, and the metabolic activity of the starter culture. In the study, morphological, biochemical, and molecular characteristics were employed to identify the bacteria obtained from homemade yogurts produced in different regions of Turkey. A collection of 91 Strep. thermophilus and 35 L. bulgaricus strains were investigated for their lactic acid- and acetaldehyde-formation capabilities in various media such as cow milk, LM17 agar, and aerobic-anaerobic SM17 agar or de Man, Rogosa, and Sharpe agar. The amounts of the metabolites generated by each strain in all conditions were quantified by HPLC. The levels were found to vary depending on the species, the strain, and the growth conditions used. Whereas lactic acid production ranged between 0 and 77.9 mg/kg for Strep. thermophilus strains, it ranged from 0 to 103.5 mg/kg for L. bulgaricus. Correspondingly, the ability to generate acetaldehyde ranged from 0 to 105.9 mg/kg in Strep. thermophilus and from 0 to 126.9 mg/kg in L. bulgaricus. Our study constitutes the first attempt to determine characteristics of the wild strains isolated from traditional Turkish yogurts, and the approach presented here, which reveals the differences in metabolite production abilities of the

  19. Volatile Compounds and Lactic Acid Bacteria in Spontaneous Fermented Sourdough

    Kam, W.Y.; Aida, W.M.W.; Sahilah, A.M.; Maskat, M.Y.

    2011-01-01

    The aim of this study is to identify the predominating lactic acid bacteria (LAB) in a spontaneous fermented wheat sourdough. At the same time, an investigation towards volatile compounds that were produced was also carried out. Lactobacillus plantarum has been identified as the dominant species of lactobacilli with characters of a facultative heterofermentative strain. The generated volatile compounds that were produced during spontaneous fermentation were isolated by solvent extraction method, analysed by gas chromatography (GC), and identified by mass spectrophotometer (MS). Butyric acid has been found to be the main volatile compound with relative abundance of 6.75 % and acetic acid at relative abundance of 3.60 %. Esters that were formed at relatively low amount were butyl formate (1.23 %) and cis 3 hexenyl propionate (0.05 %). Butanol was also found at low amount with relative abundance of 0.60 %. The carbohydrate metabolism of Lactobacillus plantarum may contributed to the production of acetic acid in this study via further catabolism activity on lactic acid that was produced. However, butyric acid was not the major product via fermentation by LAB but mostly carried out by the genus Clostridium via carbohydrate metabolism which needs further investigation. (author)

  20. Production of lactic acid from C6-polyols by alkaline hydrothermal reactions

    Zhou Huazhen; Jin Fangming; Wu Bing; Cao Jianglin; Duan Xiaokun; Kishita, Atsushi

    2010-01-01

    Production of lactic acid from C6-polyols (Mannitol) under alkaline hydrothermal conditions was investigated. Experiments were performed to examine the difference in the production of lactic acid between C6-polyols and C3-polyols (glycerine), as well as C6-aldoses (glucose). Results showed that the yield of lactic acid from C6-polyols was lower than that from both glycerine and glucose. It indicated that long chain polyols might follow a different reaction pathway from that of glycerine. Further investigation is needed to clarify the reaction mechanism and improve the relatively low lactic acid acid yield from C6-polyols.

  1. Modelling antagonic effect of lactic acid eacteria supernatants on some pathogenic bacteria

    Augustus Caeser Franke Portella

    2009-11-01

    Full Text Available This work presents a statistical model of survival analysis for three pathogenic bacterial strains (Escherichia coli, Listeria monocytogenes and Staphylococcus aureus, when treated with neutralized and non-neutralized filtered supernatants broth from cultures of Lactobacillus acidhophilus, Lactobacillus rhamnosus and Lactobacillus sake. Survival analysis is a method employed to determine the period of time from an initial stage up to the occurrence of a particular event of interest, as death or a particular culture growth failure. In order to evaluate the potential efficacy of the ahead mentioned lactic acid bacteria when used as bioprotective starters in foods, experimental data were statistically treated and expressed by simple representative curves. Following the methodology of Cox and Kaplan-Meier, it was possible to make the selection of the best bioprotective lactic starter, as a predictive tool for evaluation of shelf life and prevention of eventual risks in fresh sausages and other similar food products.Este trabalho apresenta um modelo estatístico de análise de sobrevivência para três bactérias patogénicas (Escherichia coli, Listeria monocytogenes e Staphylococcus aureus, quando tratados com sobrenadantes filtrados neutralizado e não neutralizado provenientes de culturas de Lactobacillus acidhophilus, Lactobacillus rhamnosus e Lactobacillus sake. A Análise de sobrevivência é um método utilizado para determinar o período de tempo a partir de uma fase inicial até a ocorrência de um determinado evento de interesse, como a morte ou a inibição de uma particular cultura, a fim de avaliar a eficácia potencial das referidas bactérias lácticas quando usadas como bioproteção em alimentos. Os dados experimentais foram tratados estatisticamente, seguindo a metodologia de Cox e Kaplan-Meier e foi possível fazer a seleção dos melhores fermentos láticos bioprotectivos, como uma ferramenta para avaliação preditiva, vida de

  2. Clinical Efficacy Comparison of Saccharomyces Boulardii and Lactic Acid as Probiotics in Acute Pediatric Diarrhea.

    Asmat, Shakila; Shaukat, Fouzia; Asmat, Raheela; Bakhat, Hafiz Faiq Siddique Gul; Asmat, Tauseef M

    2018-03-01

    To compare the efficacy of Saccharomyces boulardii and lactic acid producing probiotics in addition to usual treatment regimen to cure diarrhea among children (6 months to 5 years of age). Randomized controlled trial. Department of Pediatrics, Sheikh Zayed Hospital, Lahore, from February to July 2015. Children suffering from acute diarrhea were orally administered Saccharomyces boulardii and lactic acid producing probiotics for 5 days. The efficacy of administered probiotics was monitored. Patients were given Saccharomyces boulardii and lactic acid producing probiotics randomly to remove the bias. Two hundred patients randomly selected for trials; out of which, 100 were treated with Saccharomyces boulardii while the other 100 were supplemented with lactic acid concomitantly along with conventional diarrhea treatment. Results indicated that Saccharomyces boulardii treatment group has significantly higher efficacy rate (45%) compared to lactic acid producing probiotics (26%). This study concluded that Saccharomyces boulardii has a better efficacy compared to lactic acid and may be adopted as a probiotic of choice.

  3. Screening for Direct Production of Lactic Acid from Rice Starch Waste by Geobacillus stearothermophilus

    Kunasundari Balakrishnan

    2017-01-01

    Full Text Available Lactic acid recently became an important chemical where it is widely used in many industries such as food, cosmetic, chemical and pharmaceutical industry. The present study focuses on the screening for lactic acid production from rice starch waste using a thermophilic amylolytic bacterium, Geobacillus stearothermophilus. There is no information available on direct fermentation of lactic acid from rice starch waste using G. stearothermophilus. The effects of different parameters such as temperature, pH, incubation time, agitation speed, concentration of nitrogen and carbon sources on the lactic acid production were assessed. The highest concentration of lactic acid produced was 5.65 ± 0.07 g/L at operating conditions of 60°C, pH 5.5, 48 h, 200 rpm of agitation speed with 5% concentrations of both carbon and nitrogen source. The findings indicated that rice starch waste can be successfully converted to lactic acid by G. stearothermophilus.

  4. Lactic acid demineralization of shrimp shell and chitosan synthesis

    Alewo Opuada AMEH

    2015-05-01

    Full Text Available The use of lactic acid was compared to hydrochloric acid for shrimp shell demineralization in chitosan synthesis. Five different acid concentrations were considered for the study: 1.5M, 3.0M, 4.5M, 6.0M and 7.5M. After demineralization, the shrimp shell were deproteinized and subsequently deacetylated to produce chitosan using sodium hydroxide solution. The synthesized chitosan samples were characterized using solubility, FTIR, SEM, XRD and viscosity. The SEM, FTIR and XRD analysis indicated that chitosan was synthesized with a high degree of deacetylation (83.18±2.11 when lactic acid was used and 84.2±5.00 when HCl was used. The degree of deacetylation and the molecular weight of the chitosan samples were also estimated. ANOVA analysis (at 95% confidence interval indicated that acid type and concentration did not significantly affect the solubility, degree of deacetylation, viscosity and molecular weight of the chitosan within the range considered.

  5. Effects of rare sugar D-allulose on acid production and probiotic activities of dairy lactic acid bacteria.

    Kimoto-Nira, H; Moriya, N; Hayakawa, S; Kuramasu, K; Ohmori, H; Yamasaki, S; Ogawa, M

    2017-07-01

    It has recently been reported that the rare sugar d-allulose has beneficial effects, including the suppression of postprandial blood glucose elevation in humans, and can be substituted for sucrose as a low-calorie food ingredient. To examine the applications of d-allulose in the dairy industry, we investigated the effects of d-allulose on the acid production of 8 strains of yogurt starter (Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus) and 4 strains of lactococci, including potential probiotic candidates derived from dairy products. Acid production by 2 L. delbrueckii ssp. bulgaricus yogurt starter strains in milk was suppressed by d-allulose, but this phenomenon was also observed in some strains with another sugar (xylose), a sugar alcohol (sorbitol), or both. In contrast, among the dairy probiotic candidates, Lactococcus lactis H61, which has beneficial effects for human skin when drunk as part of fermented milk, was the only strain that showed suppression of acid production in the presence of d-allulose. Strain H61 did not metabolize d-allulose. We did not observe suppression of acid production by strain H61 with the addition of xylose or sorbitol, and xylose and sorbitol were not metabolized by strain H61. The acid production of strain H61 after culture in a constituted medium (tryptone-yeast extract-glucose broth) was also suppressed with the addition of d-allulose, but growth efficiency and sugar fermentation style were not altered. Probiotic activities-such as the angiotensin-converting enzyme inhibitory activity of H61-fermented milk and the superoxide dismutase activity of H61 cells grown in tryptone-yeast extract-glucose broth-were not affected by d-allulose. d-Allulose may suppress acid production in certain lactic acid bacteria without altering their probiotic activity. It may be useful for developing new probiotic dairy products from probiotic strains such as Lactococcus lactis H61. Copyright © 2017 American Dairy Science

  6. Lactic acid fermentation of dahlia tuber starch and waste using Lactobacillus bulgaricus: A comparative study

    Praputri, E.; Sundari, E.; Martynis, M.; Agenta, P.

    2018-03-01

    Lactic acid fermentation of dahlia tuber starch and waste was performed by means of Lactobacillus bulgaricus through enzymatic hydrolysis followed by fermentation process. The effect of pH condition on lactic acid production was investigated during the process. The selected bacteria produced lactic acid after 24 hours of fermentation and the productivity was increase after 24 hours of fermentation. After 120 hours of fermentation, it was found that dahlia tuber starch can produce up to 16.18% of lactic acid, whereas lactic acid produced from dahlia tuber waste was only 0.40% at pH of 4. The lactic acid production increase significantly for pH 3.5 and 4 until 96 hours of fermentation, then slowed down. On the other hand, for pH 4.5 the lactic acid production increase until 48 hours of fermentation and then slowed down. The identification of fermentation product indicated that the lactic acid produced in this study was 16.20%, acidic, yellow and cloudy with pH 3.4 – 4.2. The density of lactic acid produced ranged between 1.21 to 1.25 gr/ml.

  7. Fabrication of high-performance poly(l-lactic acid)/lignin-graft-poly(d-lactic acid) stereocomplex films.

    Liu, Rui; Dai, Lin; Hu, Li-Qiu; Zhou, Wen-Qin; Si, Chuan-Ling

    2017-11-01

    The need for green renewable alternatives such as lignin to traditional fillers has driven recent interest in polylactic acid blend materials. Herein, lignin-graft-polylactic acid copolymers (LG-g-PDLA, LG-g-PDLLA, and LG-g-PLLA) have been synthesized via ring-opening polymerization of d-, dl-, and l-lactic acid. Then poly(l-lactic acid)/lignin-graft-polylactic acid (PLLA/LG-g-PDLA, /LG-g-PDLLA, and /LG-g-PLLA) complex films have been prepared. The results showed that, compared with LG-g-PDLA and LG-g-PLLA, a small amount of LG-g-PDLA addition could improve the crystallization rate, reduce the glass transition temperature and cold crystallization temperature of PLLA due to the stereocomplex crystallites. The thermal stability, tensile strength and strain of the stereocomplex films were also enhanced. Moreover, the PLLA/LG-g-PDLA films have good ultraviolet resistance and excellent biocompatibility. This study provides a green approach to design advanced polylactic acid-based blends with renewable natural resources. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Biotechnological conversion of spent coffee grounds into lactic acid.

    Hudeckova, H; Neureiter, M; Obruca, S; Frühauf, S; Marova, I

    2018-04-01

    This work investigates the potential bioconversion of spent coffee grounds (SCG) into lactic acid (LA). SCG were hydrolysed by a combination of dilute acid treatment and subsequent application of cellulase. The SCG hydrolysate contained a considerable amount of reducing sugars (9·02 ± 0·03 g l -1 , glucose; 26·49 ± 0·10 g l -1 galactose and 2·81 ± 0·07 g l -1 arabinose) and it was used as a substrate for culturing several lactic acid bacteria (LAB) and LA-producing Bacillus coagulans. Among the screened micro-organisms, Lactobacillus rhamnosus CCM 1825 was identified as the most promising producer of LA on a SCG hydrolysate. Despite the inhibitory effect exerted by furfural and phenolic compounds in the medium, reasonably high LA concentrations (25·69 ± 1·45 g l -1 ) and yields (98%) were gained. Therefore, it could be demonstrated that SCG is a promising raw material for the production of LA and could serve as a feedstock for the sustainable large-scale production of LA. Spent coffee grounds (SCG) represent solid waste generated in millions of tonnes by coffee-processing industries. Their disposal represents a serious environmental problem; however, SCG could be valorized within a biorefinery concept yielding various valuable products. Herein, we suggest that SCG can be used as a complex carbon source for the lactic acid production. © 2018 The Society for Applied Microbiology.

  9. Phytase activity of lactic acid bacteria and their impact on the solubility of minerals from wholemeal wheat bread.

    Cizeikiene, Dalia; Juodeikiene, Grazina; Bartkiene, Elena; Damasius, Jonas; Paskevicius, Algimantas

    2015-01-01

    The objective of this study was to determinate phytase activity of bacteriocins producing lactic acid bacteria previously isolated from spontaneous rye sourdough. The results show that the highest extracellular phytase activity produces Pediococcus pentosaceus KTU05-8 and KTU05-9 strains with a volumetric phytase activity of 32 and 54 U/ml, respectively, under conditions similar to leavening of bread dough (pH 5.5 and 30 °C). In vitro studies in simulated gastrointestinal tract media pH provide that bioproducts prepared with P. pentosaceus strains used in wholemeal wheat bread preparation increase solubility of iron, zinc, manganese, calcium and phosphorus average 30%. Therefore, P. pentosaceus KTU05-9 and KTU05-8 strains could be recommended to use as a starter for sourdough preparation for increasing of mineral bioavailability from wholemeal wheat bread.

  10. Diversity and Stability of Lactic Acid Bacteria in Rye Sourdoughs of Four Bakeries with Different Propagation Parameters.

    Ene Viiard

    Full Text Available We identified the lactic acid bacteria within rye sourdoughs and starters from four bakeries with different propagation parameters and tracked their dynamics for between 5-28 months after renewal. Evaluation of bacterial communities was performed using plating, denaturing gradient gel electrophoresis, and pyrosequencing of 16S rRNA gene amplicons. Lactobacillus amylovorus and Lactobacillus frumenti or Lactobacillus helveticus, Lactobacillus pontis and Lactobacillus panis prevailed in sourdoughs propagated at higher temperature, while ambient temperature combined with a short fermentation cycle selected for Lactobacillus sanfranciscensis, Lactobacillus pontis, and Lactobacillus zymae or Lactobacillus helveticus, Lactobacillus pontis and Lactobacillus zymae. The ratio of species in bakeries employing room-temperature propagation displayed a seasonal dependence. Introduction of different and controlled propagation parameters at one bakery (higher fermentation temperature, reduced inoculum size, and extended fermentation time resulted in stabilization of the microbial community with an increased proportion of L. helveticus and L. pontis. Despite these new propagation parameters no new species were detected.

  11. l-(+)-Lactic acid production by Lactobacillus rhamnosus B103 from dairy industry waste.

    Bernardo, Marcela Piassi; Coelho, Luciana Fontes; Sass, Daiane Cristina; Contiero, Jonas

    2016-01-01

    Lactic acid, which can be obtained through fermentation, is an interesting compound because it can be utilized in different fields, such as in the food, pharmaceutical and chemical industries as a bio-based molecule for bio-refinery. In addition, lactic acid has recently gained more interest due to the possibility of manufacturing poly(lactic acid), a green polymer that can replace petroleum-derived plastics and be applied in medicine for the regeneration of tissues and in sutures, repairs and implants. One of the great advantages of fermentation is the possibility of using agribusiness wastes to obtain optically pure lactic acid. The conventional batch process of fermentation has some disadvantages such as inhibition by the substrate or the final product. To avoid these problems, this study was focused on improving the production of lactic acid through different feeding strategies using whey, a residue of agribusiness. The downstream process is a significant bottleneck because cost-effective methods of producing high-purity lactic acid are lacking. Thus, the investigation of different methods for the purification of lactic acid was one of the aims of this work. The pH-stat strategy showed the maximum production of lactic acid of 143.7g/L. Following purification of the lactic acid sample, recovery of reducing sugars and protein and color removal were 0.28%, 100% and 100%, respectively. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  12. An integrated bioconversion process for the production of L-lactic acid from starchy feedstocks

    Tsai, S.P.; Moon, S.H.

    1997-07-01

    The potential market for lactic acid as the feedstock for biodegradable polymers, oxygenated chemicals, and specialty chemicals is significant. L-lactic acid is often the desired enantiomer for such applications. However, stereospecific lactobacilli do not metabolize starch efficiently. In this work, Argonne researchers have developed a process to convert starchy feedstocks into L-lactic acid. The processing steps include starch recovery, continuous liquefaction, and simultaneous saccharification and fermentation. Over 100 g/L of lactic acid was produced in less than 48 h. The optical purity of the product was greater than 95%. This process has potential economical advantages over the conventional process.

  13. L-(+-Lactic acid production by Lactobacillus rhamnosus B103 from dairy industry waste

    Marcela Piassi Bernardo

    Full Text Available ABSTRACT Lactic acid, which can be obtained through fermentation, is an interesting compound because it can be utilized in different fields, such as in the food, pharmaceutical and chemical industries as a bio-based molecule for bio-refinery. In addition, lactic acid has recently gained more interest due to the possibility of manufacturing poly(lactic acid, a green polymer that can replace petroleum-derived plastics and be applied in medicine for the regeneration of tissues and in sutures, repairs and implants. One of the great advantages of fermentation is the possibility of using agribusiness wastes to obtain optically pure lactic acid. The conventional batch process of fermentation has some disadvantages such as inhibition by the substrate or the final product. To avoid these problems, this study was focused on improving the production of lactic acid through different feeding strategies using whey, a residue of agribusiness. The downstream process is a significant bottleneck because cost-effective methods of producing high-purity lactic acid are lacking. Thus, the investigation of different methods for the purification of lactic acid was one of the aims of this work. The pH-stat strategy showed the maximum production of lactic acid of 143.7 g/L. Following purification of the lactic acid sample, recovery of reducing sugars and protein and color removal were 0.28%, 100% and 100%, respectively.

  14. Lactic Acid Bacteria and Bifidobacteria with Potential to Design Natural Biofunctional Health-Promoting Dairy Foods.

    Linares, Daniel M; Gómez, Carolina; Renes, Erica; Fresno, José M; Tornadijo, María E; Ross, R P; Stanton, Catherine

    2017-01-01

    Consumer interest in healthy lifestyle and health-promoting natural products is a major driving force for the increasing global demand of biofunctional dairy foods. A number of commercial sources sell synthetic formulations of bioactive substances for use as dietary supplements. However, the bioactive-enrichment of health-oriented foods by naturally occurring microorganisms during dairy fermentation is in increased demand. While participating in milk fermentation, lactic acid bacteria can be exploited in situ as microbial sources for naturally enriching dairy products with a broad range of bioactive components that may cover different health aspects. Several of these bioactive metabolites are industrially and economically important, as they are claimed to exert diverse health-promoting activities on the consumer, such as anti-hypertensive, anti-inflammatory, and anti-diabetic, anti-oxidative, immune-modulatory, anti-cholesterolemic, or microbiome modulation. This review aims at discussing the potential of these health-supporting bacteria as starter or adjunct cultures for the elaboration of dairy foods with a broad spectrum of new functional properties and added value.

  15. Dominant lactic acid bacteria in artisanal Pirot cheeses of different ripening period

    Terzić-Vidojević Amarela

    2009-01-01

    Full Text Available In this study two raw cow's milk cheeses of a different ripening period were examined. The cheeses were taken from a country household in the region of mountain Stara Planina and manufactured without adding of starter culture. A total 106 lactic acid bacteria (LAB strains were isolated from both cheeses. They are tested by classical physiological tests as well as by API 50 CH tests. Proteolytic and antimicrobial activities were done too. Identification of LAB isolates was done by repetitive extragenic palindromic-polimerase chain reaction (rep-PCR with (GTG5 primer. The LAB isolates from cheese BGPT9 (four days old belonged to the eight species of LAB (Lactobacillus plantarum, Lactobacillus paracasei subsp. paracasei, Lactobacillus delbrueckii, Lactobacillus brevis, Enterococcus faecium, Enterococcus faecalis, Enterococcus durans and Leuconostoc garlicum, while in the BGPT10 cheese (eight months old only two species were present (Lactobacillus plantarum and Enterococcus faecium. Proteolytic activity showed 30 LAB from BGPT9 cheese, mainly enterococci. From BGPT10 cheese only one isolate (which belonged to the Lactobacillus plantarum species possessed partial ability to hydrolyze β-casein. Seven enterococci from BGPT9 cheese and four enterococci from BGPT10 cheese produced antimicrobial compounds.

  16. Genetic and Technological Characterisation of Vineyard- and Winery-Associated Lactic Acid Bacteria

    Aspasia A. Nisiotou

    2015-01-01

    Full Text Available Vineyard- and winery-associated lactic acid bacteria (LAB from two major PDO regions in Greece, Peza and Nemea, were surveyed. LAB were isolated from grapes, fermenting musts, and winery tanks performing spontaneous malolactic fermentations (MLF. Higher population density and species richness were detected in Nemea than in Peza vineyards and on grapes than in fermenting musts. Pediococcus pentosaceus and Lactobacillus graminis were the most abundant LAB on grapes, while Lactobacillus plantarum dominated in fermenting musts from both regions. No particular structure of Lactobacillus plantarum populations according to the region of origin was observed, and strain distribution seems random. LAB species diversity in winery tanks differed significantly from that in vineyard samples, consisting principally of Oenococcus oeni. Different strains were analysed as per their enological characteristics and the ability to produce biogenic amines (BAs. Winery-associated species showed higher resistance to low pH, ethanol, SO2, and CuSO4 than vineyard-associated isolates. The frequency of BA-producing strains was relatively low but not negligible, considering that certain winery-associated Lactobacillus hilgardii strains were able to produce BAs. Present results show the necessity of controlling the MLF by selected starters in order to avoid BA accumulation in wine.

  17. Using physical approaches for the attenuation of lactic acid bacteria in an organic rice beverage.

    Bevilacqua, Antonio; Casanova, Francesco Pio; Petruzzi, Leonardo; Sinigaglia, Milena; Corbo, Maria Rosaria

    2016-02-01

    A wild strain of Lactobacillus plantarum, isolated from an Italian sourdough, was inoculated in an organic rice drink; however, it caused a strong acidification. Thus, it was preliminary processed through homogenization (single or multiple passes) or sonication (US) and then inoculated in the beverage. The samples were stored at 4 °C and analyzed to assess pH, production of lactic acid, viable count and sensory scores. A US-2-step process (power, 80%) could control acidification; viability and sensory traits were never affected by sonication. This result was confirmed on two commercial probiotics (Lactobacillus casei LC01 and Bifidobacterium animalis subsp. lactis Bb12). In the 2nd step samples inoculated with attenuated strains were also stored under thermal abuse conditions (25 or 37 °C for 4 or 24 h, then at 4 °C) and the results showed that US could control acidification for a short thermal abuse. Finally, US-attenuated starter cultures were inoculated in the rice drink containing β-glucans as healthy compounds; the targets did not cause any significant change of prebiotic. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Current state of purification, isolation and analysis of bacteriocins produced by lactic acid bacteria.

    Kaškonienė, Vilma; Stankevičius, Mantas; Bimbiraitė-Survilienė, Kristina; Naujokaitytė, Gintarė; Šernienė, Loreta; Mulkytė, Kristina; Malakauskas, Mindaugas; Maruška, Audrius

    2017-02-01

    The scientific interest for the search of natural means of microbial inhibitors has not faded for several years. A search of natural antibiotics, so-called bacteriocins which are produced by lactic acid bacteria (LAB), gains a huge attention of the scientists in the last century, in order to reduce the usage of synthetic food additives. Pure bacteriocins with wide spectra of antibacterial activity are promising among the natural biopreservatives. The usage of bacteriocin(s) producing LAB as starter culture for the fermentation of some food products, in order to increase their shelf-life, when synthetic preservatives are not allowable, is also possible. There are a lot of studies focusing on the isolation of new bacteriocins from traditional fermented food, dairy products and other foods or sometimes even from unusual non-food matrices. Bacteriocins producing bacteria have been isolated from different sources with the different antibacterial activity against food-borne microorganisms. This review covers the classification of bacteriocins, diversity of sources of bacteriocin(s) producing LAB, antibacterial spectra of isolated bacteriocins and analytical methods for the bacteriocin purification and analysis within the last 15 years.

  19. Genetic and technological characterisation of vineyard- and winery-associated lactic acid bacteria.

    Nisiotou, Aspasia A; Dourou, Dimitra; Filippousi, Maria-Evangelia; Diamantea, Ellie; Fragkoulis, Petros; Tassou, Chryssoula; Banilas, Georgios

    2015-01-01

    Vineyard- and winery-associated lactic acid bacteria (LAB) from two major PDO regions in Greece, Peza and Nemea, were surveyed. LAB were isolated from grapes, fermenting musts, and winery tanks performing spontaneous malolactic fermentations (MLF). Higher population density and species richness were detected in Nemea than in Peza vineyards and on grapes than in fermenting musts. Pediococcus pentosaceus and Lactobacillus graminis were the most abundant LAB on grapes, while Lactobacillus plantarum dominated in fermenting musts from both regions. No particular structure of Lactobacillus plantarum populations according to the region of origin was observed, and strain distribution seems random. LAB species diversity in winery tanks differed significantly from that in vineyard samples, consisting principally of Oenococcus oeni. Different strains were analysed as per their enological characteristics and the ability to produce biogenic amines (BAs). Winery-associated species showed higher resistance to low pH, ethanol, SO2, and CuSO4 than vineyard-associated isolates. The frequency of BA-producing strains was relatively low but not negligible, considering that certain winery-associated Lactobacillus hilgardii strains were able to produce BAs. Present results show the necessity of controlling the MLF by selected starters in order to avoid BA accumulation in wine.

  20. Lactic Acid Bacteria and Bifidobacteria with Potential to Design Natural Biofunctional Health-Promoting Dairy Foods

    Daniel M. Linares

    2017-05-01

    Full Text Available Consumer interest in healthy lifestyle and health-promoting natural products is a major driving force for the increasing global demand of biofunctional dairy foods. A number of commercial sources sell synthetic formulations of bioactive substances for use as dietary supplements. However, the bioactive-enrichment of health-oriented foods by naturally occurring microorganisms during dairy fermentation is in increased demand. While participating in milk fermentation, lactic acid bacteria can be exploited in situ as microbial sources for naturally enriching dairy products with a broad range of bioactive components that may cover different health aspects. Several of these bioactive metabolites are industrially and economically important, as they are claimed to exert diverse health-promoting activities on the consumer, such as anti-hypertensive, anti-inflammatory, and anti-diabetic, anti-oxidative, immune-modulatory, anti-cholesterolemic, or microbiome modulation. This review aims at discussing the potential of these health-supporting bacteria as starter or adjunct cultures for the elaboration of dairy foods with a broad spectrum of new functional properties and added value.

  1. Production of Synbiotic Yogurt-Like Using Indigenous Lactic Acid Bacteria as Functional Food

    M. Astawan

    2012-04-01

    Full Text Available Yoghurt is a product of fermented milk using Lactobacillus bulgaricus and Streptococcus thermophilus as culture starter. Indigenous probiotic lactic acid bacteria, Lactobacillus plantarum 2C12 or Lactobacillus acidophilus 2B4, were applied in the making of functional synbiotic yoghurt-like with 5% of fructo-oligosaccharide (FOS as a prebiotic source. The aim of this study was to determine the best formula of functional synbiotic yoghurt-like among four formulas: F1 (L. bulgaricus + S. thermophilus, F2 (L. bulgaricus + S. thermophilus + L. plantarum 2C12, F3 (L. bulgaricus+ S. thermophilus + L. acidophilus 2B4, and F4 (L. bulgaricus + S. thermophilus + L. plantarum 2C12 + L. acidophilus 2B4 to be choosen and followed detection of it’s flavor to improve the product quality and consumer acceptance. The results showed that the F3 synbiotic yogurt made from mixed culture L. bulgaricus, S. thermophilus, and L. acidophilus 2B4 had the highest antibacterial effect against Enteropathogenic Escherichia coli (EPEC. Addition of 1.75% natural corn starch as a stabilizer produced optimum improvement in yoghurt consistency and minimize whey separation. Result of sensory evaluation indicated that the yoghurt with addition of 1% strawberry flavor and 0.1% vanilla flavor were ranked at first and second. Yoghurts were still good to be consumed after 15 d storage period at the refrigeration temperature (10 oC.

  2. Dadih Susu Sapi Hasil Fermentasi Berbagai Starter Bakteri Probiotik yang Disimpan pada Suhu Rendah: II. Karakteristik Fisik, Organoleptik dan Mikrobiologi

    E. Taufik

    2005-04-01

    Full Text Available This research was conducted to investigate physical, organoleptical and microbiological characteristics of dadih from cow milk fermented with different combinations of probiotic starter bacteria and stored at low temperature. The concentration of starter used to make dadih was 3% with equal comparison between starters. The combinations of probiotic starter bacteria were (L. plantarum (A1, L. plantarum + L. acidophilus (A2, L. plantarum + B. bifidum (A3 and L. plantarum + L. acidophilus + B. bifidum (A4 and stored at low temperatures (refrigerator for 0, 7 and 14 days. The observed variables were viscosity, total lactic acid bacteria, total Bifidobacterium bifidum and organoleptic properties (color, aroma, taste and firmness. The result showed that combinations of probiotic starter bacteria did not affect significantly (P>0.05 viscosity and total Bificobacterium bifidum of dadih at H-0 (before storage, but affect significantly (P<0.05 total lactic acid bacteria. The characteristics of dadih during 14 days of storage in low temperature showed that combinations of starter did not significantly affect viscosity but storage time affect significantly (P<0.05. Total Bificobacterium bifidum was not affected significantly by either starter combination or storage time.Total lactic acid bacteria was significantly affected (P<0.05 by storage time and very significantly affected (P<0.01 by starter combinations. A4 starter combination (L. plantarum + L. acidophilus + B. bifidum has the most preference modus value for firmness, color, flavor and aroma according to panelist test result. Among those four organoleptic parameters, only aroma was affected significantly by starter combination.

  3. Sensitive determination of D-lactic acid and L-lactic acid in urine by high-performance liquid chromatography-tandem mass spectrometry.

    Henry, H; Marmy Conus, N; Steenhout, P; Béguin, A; Boulat, O

    2012-04-01

    D-lactic acid in urine originates mainly from bacterial production in the intestinal tract. Increased D-lactate excretion as observed in patients affected by short bowel syndrome or necrotizing enterocolitis reflects D-lactic overproduction. Therefore, there is a need for a reliable and sensitive method able to detect D-lactic acid even at subclinical elevation levels. A new and highly sensitive method for the simultaneous determination of L- and D-lactic acid by a two-step procedure has been developed. This method is based on the concentration of lactic acid enantiomers from urine by supported liquid extraction followed by high-performance liquid chromatography-tandem mass spectrometry. The separation was achieved by the use of an Astec Chirobiotic™ R chiral column under isocratic conditions. The calibration curves were linear over the ranges of 2-400 and 0.5-100 µmol/L respectively for L- and D-lactic acid. The limit of detection of D-lactic acid was 0.125 µmol/L and its limit of quantification was 0.5 µmol/L. The overall accuracy and precision were well within 10% of the nominal values. The developed method is suitable for production of reference values in children and could be applied for accurate routine analysis. Copyright © 2011 John Wiley & Sons, Ltd.

  4. L-lactic acid production by Aspergillus brasiliensis overexpressing the heterologous ldha gene from Rhizopus oryzae.

    Liaud, Nadège; Rosso, Marie-Noëlle; Fabre, Nicolas; Crapart, Sylvaine; Herpoël-Gimbert, Isabelle; Sigoillot, Jean-Claude; Raouche, Sana; Levasseur, Anthony

    2015-05-03

    Lactic acid is the building block of poly-lactic acid (PLA), a biopolymer that could be set to replace petroleum-based plastics. To make lactic acid production cost-effective, the production process should be carried out at low pH, in low-nutrient media, and with a low-cost carbon source. Yeasts have been engineered to produce high levels of lactic acid at low pH from glucose but not from carbohydrate polymers (e.g. cellulose, hemicellulose, starch). Aspergilli are versatile microbial cell factories able to naturally produce large amounts of organic acids at low pH and to metabolize cheap abundant carbon sources such as plant biomass. However, they have never been used for lactic acid production. To investigate the feasibility of lactic acid production with Aspergillus, the NAD-dependent lactate dehydrogenase (LDH) responsible for lactic acid production by Rhizopus oryzae was produced in Aspergillus brasiliensis BRFM103. Among transformants, the best lactic acid producer, A. brasiliensis BRFM1877, integrated 6 ldhA gene copies, and intracellular LDH activity was 9.2 × 10(-2) U/mg. At a final pH of 1.6, lactic acid titer reached 13.1 g/L (conversion yield: 26%, w/w) at 138 h in glucose-ammonium medium. This extreme pH drop was subsequently prevented by switching nitrogen source from ammonium sulfate to Na-nitrate, leading to a final pH of 3 and a lactic acid titer of 17.7 g/L (conversion yield: 47%, w/w) at 90 h of culture. Final titer was further improved to 32.2 g/L of lactic acid (conversion yield: 44%, w/w) by adding 20 g/L glucose to the culture medium at 96 h. This strain was ultimately able to produce lactic acid from xylose, arabinose, starch and xylan. We obtained the first Aspergillus strains able to produce large amounts of lactic acid by inserting recombinant ldhA genes from R. oryzae into a wild-type A. brasiliensis strain. pH regulation failed to significantly increase lactic acid production, but switching nitrogen source and changing culture feed

  5. [Design of primers to DNA of lactic acid bacteria].

    Lashchevskiĭ, V V; Kovalenko, N K

    2003-01-01

    Primers LP1-LP2 to the gene 16S rRNA have been developed, which permit to differentiate lactic acid bacteria: Lactobacillus plantarum, L. delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus. The strain-specific and species-specific differentiations are possible under different annealing temperature. Additional fragments, which are synthesized outside the framework of gene 16S rRNA reading, provide for the strain-specific type of differentiation, and the fragment F864 read in the gene 16S rRNA permits identifying L. plantarum.

  6. [Genetic stability of probiotic lactic acid bacteria--a review].

    Zhang, Wenyi; Bai, Mei; Zhang, Heping

    2014-04-04

    Growing attention has been focused on probiotic lactic acid bacteria because of their important health-promoting effects. Nowadays, probiotic-based products have become fashionable nutraceuticals of choice. Before a newly developed probiotic-based product is to be introduced into the industry, it is important to ensure not only the desirable properties of the probiotic strain but also a good genetic stability. This article firstly introduces the research methods for investigating genetic stability, followed by summarizing the latest research progress in China and overseas.

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

    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.

  8. Codominance of Lactobacillus plantarum and obligate heterofermentative lactic acid bacteria during sourdough fermentation.

    Ventimiglia, Giusi; Alfonzo, Antonio; Galluzzo, Paola; Corona, Onofrio; Francesca, Nicola; Caracappa, Santo; Moschetti, Giancarlo; Settanni, Luca

    2015-10-01

    Fifteen sourdoughs produced in western Sicily (southern Italy) were analysed by classical methods for their chemico-physical characteristics and the levels of lactic acid bacteria (LAB). pH and total titratable acidity (TTA) were mostly in the range commonly reported for similar products produced in Italy, but the fermentation quotient (FQ) of the majority of samples was above 4.0, due to the low concentration of acetic acid estimated by high performance liquid chromatography (HPLC). Specific counts of LAB showed levels higher than 10(8) CFU g(-1) for many samples. The colonies representing various morphologies were isolated and, after the differentiation based on phenotypic characteristics, divided into 10 groups. The most numerous group was composed of facultative heterofermentative isolates, indicating a relevance of this bacterial group during fermentation. The genetic analysis by randomly amplified polymorphic DNA (RAPD)-PCR, 16S rRNA gene sequencing and species-specific PCRs identified 33 strains as Lactobacillus plantarum, Lactobacillus curvatus and Lactobacillus graminis. Due to the consistent presence of L. plantarum, it was concluded that this species codominates with obligate heterofermentative LAB in sourdough production in this geographical area. In order to evaluate the performances at the basis of their fitness, the 29 L. plantarum strains were investigated for several technological traits. Twelve cultures showed good acidifying abilities in vitro and L. plantarum PON100148 produced the highest concentrations of organic acids. Eleven strains were positive for extracellular protease activity. Bacteriocin-like inhibitory substances (BLIS) production and antifungal activity was scored positive for several strains, included L. plantarum PON100148 which was selected as starter for experimental sourdough production. The characteristics of the sourdoughs and the resulting breads indicated that the best productions were obtained in presence of L

  9. The Effect of Starter Culture Producing Exopolysaccharide on Physicochemical Properties of Yoghurt

    Anatoli Cartasev

    2017-12-01

    Full Text Available The purpose of this research was to investigate the impact of indigenous starter culture capable to synthesize exopolysaccharides (EPSs on physicochemical properties of yoghurt. Two starter cultures, EPS-producing and non-EPS-producing, were developed from the autochthonous lactic acid bacteria strains by pairwise combining Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus strains. In the present study the ropy strain of Streptococcus thermophilus CNMN LB-50 was incorporated in EPS-producing starter culture. The microstructure, viscosity, EPS amount, structural properties and syneresis of yoghurt samples were assessed. It has been established that the EPS-producing starter culture provided a reduction of structural degradation and increased degree of structural recovery after deformation. Besides, it was observed that the use of EPS synthesized starter culture in yoghurt production restrains the syneresis of the gel.

  10. Improvement of lactic acid production in Saccharomyces cerevisiae by a deletion of ssb1.

    Lee, Jinsuk J; Crook, Nathan; Sun, Jie; Alper, Hal S

    2016-01-01

    Polylactic acid (PLA) is an important renewable polymer, but current processes for producing its precursor, lactic acid, suffer from process inefficiencies related to the use of bacterial hosts. Therefore, improving the capacity of Saccharomyces cerevisiae to produce lactic acid is a promising approach to improve industrial production of lactic acid. As one such improvement required, the lactic acid tolerance of yeast must be significantly increased. To enable improved tolerance, we employed an RNAi-mediated genome-wide expression knockdown approach as a means to rapidly identify potential genetic targets. In this approach, several gene knockdown targets were identified which confer increased acid tolerance to S. cerevisiae BY4741, of which knockdown of the ribosome-associated chaperone SSB1 conferred the highest increase (52%). This target was then transferred into a lactic acid-overproducing strain of S. cerevisiae CEN.PK in the form of a knockout and the resulting strain demonstrated up to 33% increased cell growth, 58% increased glucose consumption, and 60% increased L-lactic acid production. As SSB1 contains a close functional homolog SSB2 in yeast, this result was counterintuitive and may point to as-yet-undefined functional differences between SSB1 and SSB2 related to lactic acid production. The final strain produced over 50 g/L of lactic acid in under 60 h of fermentation.

  11. Arginine- and Polyamine-Induced Lactic Acid Resistance in Neisseria gonorrhoeae.

    Zheng Gong

    Full Text Available Microbe-derived lactic acid protects women from pathogens in their genital tract. The purpose of this study was to determine lactic acid susceptibility of Neisseria gonorrhoeae, and identify potential acid resistance mechanisms present in this pathogen. Tested in vitro, lactic acid killed all 10 gonococcal strains analyzed in a low pH-dependent manner. Full inactivation occurred at pH 4.5. At low pH, lactic acid treatment resulted in the entry of the DNA-binding fluorochrome propidium iodide into the microbial cells, suggesting that hydrogen ions from lactic acid compromise the integrity of the bacterial cell wall/membrane. Most likely, hydrogen ions also inactivate intracellular proteins since arginine rendered significant protection against lactic acid presumably through action of the gonococcal arginine decarboxylase, an enzyme located in the bacterial cytoplasm. Surprisingly, arginine also lessened lactic acid-mediated cell wall/membrane disruption. This effect is probably mediated by agmatine, a triamine product of arginine decarboxylase, since agmatine demonstrated a stronger protective effect on GC than arginine at equal molar concentration. In addition to agmatine, diamines cadaverine and putrescine, which are generated by bacterial vaginosis-associated microbes, also induced significant resistance to lactic acid-mediated GC killing and cell wall/membrane disruption. These findings suggest that the arginine-rich semen protects gonococci through both neutralization-dependent and independent mechanisms, whereas polyamine-induced acid resistance contributes to the increased risk of gonorrhea in women with bacterial vaginosis.

  12. Enhanced D-lactic acid production from renewable resources using engineered Lactobacillus plantarum.

    Zhang, Yixing; Vadlani, Praveen V; Kumar, Amit; Hardwidge, Philip R; Govind, Revathi; Tanaka, Tsutomu; Kondo, Akihiko

    2016-01-01

    D-lactic acid is used as a monomer in the production of poly-D-lactic acid (PDLA), which is used to form heat-resistant stereocomplex poly-lactic acid. To produce cost-effective D-lactic acid by using all sugars derived from biomass efficiently, xylose-assimilating genes encoding xylose isomerase and xylulokinase were cloned into an L-lactate-deficient strain, Lactobacillus plantarum. The resulting recombinant strain, namely L. plantarum NCIMB 8826 ∆ldhL1-pLEM-xylAB, was able to produce D-lactic acid (at optical purity >99 %) from xylose at a yield of 0.53 g g(-1). Simultaneous utilization of glucose and xylose to produce D-lactic acid was also achieved by this strain, and 47.2 g L(-1) of D-lactic acid was produced from 37.5 g L(-1) glucose and 19.7 g L(-1) xylose. Corn stover and soybean meal extract (SBME) were evaluated as cost-effective medium components for D-lactic acid production. Optimization of medium composition using response surface methodology resulted in 30 % reduction in enzyme loading and 70 % reduction in peptone concentration. In addition, we successfully demonstrated D-lactic acid fermentation from corn stover and SBME in a fed-batch fermentation, which yielded 61.4 g L(-1) D-lactic acid with an overall yield of 0.77 g g(-1). All these approaches are geared to attaining high D-lactic acid production from biomass sugars to produce low-cost, highly thermostable biodegradable plastics.

  13. Phenolic Biotransformations during Conversion of Ferulic Acid to Vanillin by Lactic Acid Bacteria

    Baljinder Kaur

    2013-01-01

    Full Text Available Vanillin is widely used as food additive and as a masking agent in various pharmaceutical formulations. Ferulic acid is an important precursor of vanillin that is available in abundance in cell walls of cereals like wheat, corn, and rice. Phenolic biotransformations can occur during growth of lactic acid bacteria (LAB, and their production can be made feasible using specialized LAB strains that have been reported to produce ferulic acid esterases. The present study aimed at screening a panel of LAB isolates for their ability to release phenolics from agrowaste materials like rice bran and their biotransformation to industrially important compounds such as ferulic acid, 4-ethyl phenol, vanillic acid, vanillin, and vanillyl alcohol. Bacterial isolates were evaluated using ferulic acid esterase, ferulic acid decarboxylase, and vanillin dehydrogenase assays. This work highlights the importance of lactic acid bacteria in phenolic biotransformations for the development of food grade flavours and additives.

  14. Phenolic biotransformations during conversion of ferulic acid to vanillin by lactic acid bacteria.

    Kaur, Baljinder; Chakraborty, Debkumar; Kumar, Balvir

    2013-01-01

    Vanillin is widely used as food additive and as a masking agent in various pharmaceutical formulations. Ferulic acid is an important precursor of vanillin that is available in abundance in cell walls of cereals like wheat, corn, and rice. Phenolic biotransformations can occur during growth of lactic acid bacteria (LAB), and their production can be made feasible using specialized LAB strains that have been reported to produce ferulic acid esterases. The present study aimed at screening a panel of LAB isolates for their ability to release phenolics from agrowaste materials like rice bran and their biotransformation to industrially important compounds such as ferulic acid, 4-ethyl phenol, vanillic acid, vanillin, and vanillyl alcohol. Bacterial isolates were evaluated using ferulic acid esterase, ferulic acid decarboxylase, and vanillin dehydrogenase assays. This work highlights the importance of lactic acid bacteria in phenolic biotransformations for the development of food grade flavours and additives.

  15. Phenolic Biotransformations during Conversion of Ferulic Acid to Vanillin by Lactic Acid Bacteria

    Kaur, Baljinder; Kumar, Balvir

    2013-01-01

    Vanillin is widely used as food additive and as a masking agent in various pharmaceutical formulations. Ferulic acid is an important precursor of vanillin that is available in abundance in cell walls of cereals like wheat, corn, and rice. Phenolic biotransformations can occur during growth of lactic acid bacteria (LAB), and their production can be made feasible using specialized LAB strains that have been reported to produce ferulic acid esterases. The present study aimed at screening a panel of LAB isolates for their ability to release phenolics from agrowaste materials like rice bran and their biotransformation to industrially important compounds such as ferulic acid, 4-ethyl phenol, vanillic acid, vanillin, and vanillyl alcohol. Bacterial isolates were evaluated using ferulic acid esterase, ferulic acid decarboxylase, and vanillin dehydrogenase assays. This work highlights the importance of lactic acid bacteria in phenolic biotransformations for the development of food grade flavours and additives. PMID:24066293

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

    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.

  17. Cocrystallization as a tool to solve deliquescence issues: The case of L-lactic acid

    de Maere d'Aertrycke, J. B.; Robeyns, K.; Willocq, J.; Leyssens, T.

    2017-08-01

    L-Lactic acid is an organic acid used in various fields such as food, cosmetic or pharmaceutical industry. It furthermore is the building-block of poly-lactic acid, a biodegradable and bioavailable polymer. Still, handling L-lactic acid under its solid form remains less straightforward mainly due to its deliquescent behavior, a phase transition from the solid to the dissolved state resulting from air humidity absorption. If several techniques are already known to avoid or reduce deliquescence, the use of cocrystallization in this context is still poorly investigated. In this paper, we investigate whether cocrystallization can be used as a suitable solution for deliquescence in the case of L-lactic acid. Out of 32 possible coformers tested, four were found to form cocrystals with L-lactic acid and the crystal structures of 1:1 L-lactic acid:D-tryptophan and 1:1 L-lactic acid:3-nitrobenzamide were determined. The hygroscopic behavior of these latter two was studied and compared to the behavior of pure L-lactic acid. Significant improvement was observed: dynamic vapor sorption at 25 °C revealed that water absorbed at 90% relative humidity dropped from 1.3157 g/gsample to 0.0017 g/gsample or 0.0299 g/gsample, with cocrystals of D-tryptophan and 3-nitrobenzamide respectively. This illustrates the effectiveness of cocrystallization as a tool to treat deliquescent materials.

  18. Community dynamics of complex starter cultures for Gouda-type cheeses and its functional consequences

    Erkus, O.

    2014-01-01

    Lactic acid bacteria (LAB) are used as starter and adjunct cultures for the production of artisanal and industrial fermented milk products such as yoghurt and cheese. Artisanal fermentations is propagated with the transfer of an inoculum from old batch of fermented food to the new batch

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

    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...

  20. Probiotic lactic acid bacteria for applications in vegetarian food products

    Charernjiratrakul, W.

    2007-07-01

    Full Text Available Total of 225 isolates of lactic acid bacteria were isolated from 152 samples of various fermented foods. The strains were investigated for their probiotic properties based on stability in bile salt (0.30% and high acidity (pH 3, growth under both aerobic and anaerobic conditions, ability to grow without vitamin B12. According to the above criteria, 40 isolates were selected. Using an agar spot method, 16 isolates were able to inhibit Salmonella typhimurium, S. typhi, S. enteritidis, S. paratyphi and 4 strains of E. coli O157 : H7 as clear zone greater than 10 mm. Moreover, utilization of protein or fat or starch was also considered. Only 5 isolates were able to utilize protein and further selected for antibiotics sensitivity test. The selected isolates were susceptible to following antibiotics: ampicillin, chloramphenicol, erythromycin , kanamycin, tetracycline and vancomycin; however they were resistant to ceptazidime and norfloxacin. They all showed better growth in vegetarian medium (coconut juice medium than MRS medium both under static and shaking conditions. Five active isolates were identified as Lactobacillus plantarum LL13, LN18, LP11, LS35 and Pediococcus pentosaceus LT02 by API 50 CH system. All cultures grew well in carrot juice by reducing pH from 6.4 to below 4.0 after 24 h of fermentation at 35oC. The lactic cultures in fermented carrot juice lost their viability about 2 log cycles after 15 days of cold storage at 4oC.

  1. Facial volumetric correction with injectable poly-L-lactic acid.

    Vleggaar, Danny

    2005-11-01

    Polymers of lactic acid'have been widely used for many years in different types of medical devices, such as resorbable sutures, intrabone implants, and soft tissue implants. Injectable poly-L-lactic acid (PLLA; Sculptra), a synthetic, biodegradable polymer, has gained widespread popularity in Europe for the treatment of facial changes associated with aging. To provide background information on injectable PLLA and to describe clinical experience with its use in Europe for facial volume enhancement. Technique varies with site of injection. Generally, the product is implanted subcutaneously or intradermally in a series of treatments. No allergy testing is required. Based on experience in more than 2,500 patients, injectable PLLA has been used successfully for the correction of nasolabial folds, mid- and lower facial volume loss, jawline laxity, and other signs of facial aging. Correction lasts for 18 to 24 months in most patients. Injectable PLLA treatment provides an excellent and prolonged correction of a variety of facial wrinkles, depressions, and laxity with a minimally invasive procedure that does not require allergy testing or a recovery period.

  2. Bacteriocins from lactic acid bacteria as an alternative to antibiotics

    Aleksandra Ołdak

    2017-05-01

    Full Text Available Bacteriocins are ribosomally synthesized, proteinaceous substances that inhibit the growth of closely related species through numerous mechanisms. The classification system used in this review divided bacteriocins into four sub-groups based on their size. Currently, there is extensive research focused on bacteriocins and their usage as a food preservative.The increasing incidence of multidrug resistant bacterial pathogens is one of the most pressing medical problems in recent years. Recently, the potential clinical application of LAB (Lactic Acid Bacteria bacteriocin has been the subject of investigations by many scientists.Bacteriocins can be considered in a sense as antibiotic, although they differ from conventional antibiotics in numerous aspects. The gene-encoded nature of bacteriocins makes them easily amenable through bioengineering to either increase their activity or specify target microorganism. Owing to this feature of bacteriocins, antibiotic therapy would become less damaging to the natural gut microflora, which is a common drawback of conventional antibiotic use. Bacteriocins from lactic acid bacteria represent one of the most studied microbial defense systems and the idea of subjecting them to bioengineering to either increase antimicrobial activity or further specify their target microorganism is now a rapidly expanding field. This review aimed to present bacteriocins as a possible alternative to conventional antibiotics basic on latest scientific data.

  3. Probiotic properties of endemic strains of lactic acid bacteria

    Flora N. Tkhruni

    2013-01-01

    Full Text Available Strains of lactic acid bacteria (LAB isolated from various samples of matsun, yogurt and salted cheese from natural farms of Armenia were studied. They have high antimicrobial and probiotic activities, growth rate and differ by their resistance to enzymes. Supernatants of LAB retain bactericidal activity at рН 3.0-8.0 and inhibit growth of various microflora. The application of different methods of identification and LAB genotyping (API 50 CH, 16S rRNA sequencing, GS-PCR, RAPD PCR showed that isolated LAB evidenced a 99.9% similarity with L. rhamnosus, L. plantarum and L. pentosus species and coccoid forms of Streptococcus and Enterococcus species. It can be concluded, that some strains of lactic acid bacteria, isolated from dairy products from natural farms of Armenia, can be properly used for biopreservation of some foodstuffs. On the basis of experimental data, the LAB can be used as basis for obtaining the new products of functional nutrition.

  4. The use of lactic acid bacteria to reduce mercury bioaccessibility.

    Jadán-Piedra, C; Alcántara, C; Monedero, V; Zúñiga, M; Vélez, D; Devesa, V

    2017-08-01

    Mercury in food is present in either inorganic [Hg(II)] or methylmercury (CH 3 Hg) form. Intestinal absorption of mercury is influenced by interactions with other food components. The use of dietary components to reduce mercury bioavailability has been previously proposed. The aim of this work is to explore the use of lactic acid bacteria to reduce the amount of mercury solubilized after gastrointestinal digestion and available for absorption (bioaccessibility). Ten strains were tested by addition to aqueous solutions containing Hg(II) or CH 3 Hg, or to food samples, and submission of the mixtures to gastrointestinal digestion. All of the strains assayed reduce the soluble fraction from standards of mercury species under gastrointestinal digestion conditions (72-98%). However their effectiveness is lower in food, and reductions in bioaccessibility are only observed with mushrooms (⩽68%). It is hypothesized that bioaccessible mercury in seafood forms part of complexes that do not interact with lactic acid bacteria. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. SOLID AND LIQUID PINEAPPLE WASTE UTILIZATION FOR LACTIC ACID FERMENTATION USING Lactobacillus delbrueckii

    Abdullah Abdullah

    2012-01-01

    Full Text Available The liquid and solid  pineapple wastes contain mainly sucrose, glucose, fructose and other nutrients. It therefore can potentially be used as carbon source for fermentation to produce organic acid. Recently, lactic acid has been considered to be an important raw material for production of biodegradable lactate polymer. The experiments were  carried out in batch fermentation using  the  liquid and solid pineapple wastes to produce lactic acid. The anaerobic fermentation of lactic acid were performed at 40 oC, pH 6, 5% inocolum and  50 rpm. Initially  results show that the liquid pineapple waste by  using Lactobacillus delbrueckii can be used as carbon source  for lactic acid fermentation. The production of lactic acid  are found to be 79 % yield, while only  56% yield was produced by using solid waste. 

  6. Purification of bacteriocins produced by lactic acid bacteria.

    Saavedra, Lucila; Castellano, Patricia; Sesma, Fernando

    2004-01-01

    Bacteriocins are antibacterial substances of a proteinaceous nature that are produced by different bacterial species. Lactic acid bacteria (LAB) produce biologically active peptides or protein complexes that display a bactericidal mode of action almost exclusively toward Gram-positive bacteria and particularly toward closely related species. Generally they are active against food spoilage and foodborne pathogenic microorganisms including Bacillus cereus, Clostridium perfringens, Staphylococcus aureus, and Listeria monocytogenes. There is an increased tendency to use natural occurring metabolites to prevent the growth of undesirable flora in foodstuffs. These metabolites could replace the use of chemical additives such as sorbic acid, sulfur dioxide, nitrite, nitrate, and others. For instance, bacteriocins produced by LAB may be promising for use as bio-preservaties. Bacteriocins of lactic acid bacteria are typically cationic, hydrophobic peptides and differ widely in many characteristics including molecular weight, presence of particular groups of amino acids, pI, net positive charge, and post-translational modifications of certain amino acids. This heterogeneity within the LAB bacteriocins may explain the different procedures for isolation and purification developed so far. The methods most frequently used for isolation, concentration, and purification involve salt precipitation of bacteriocins from culture supernatants, followed by various combinations of gel filtration, ion-exchange chromatography, and reverse-phase high-performance liquid chromatography (RP-HPLC). In this chapter, a protocol is described that combines several methods used in our laboratory for the purification of two cationic bacteriocins, Lactocin 705AL and Enterocin CRL10, produced by Lactobacillus casei CRL705 and Enterococcus mundtii CRL10, respectively.

  7. Lactococcus lactis ssp. lactis as Potential Functional Starter Culture

    Jelena Cvrtila

    2014-01-01

    Full Text Available The aim of this study is to identify and characterise potential autochthonous functional starter cultures in homemade horsemeat sausage. The dominant microflora in the samples of horsemeat sausage were lactic acid bacteria (LAB, followed by micrococci. Among the LAB, Lactococcus lactis ssp. lactis and Lactobacillus plantarum were the dominant species, and since the first is not common in fermented sausages, we characterised it as a potential functional starter culture. Lactococcus lactis ssp. lactis produced a significant amount of lactic acid, displayed good growth capability at 12, 18 and 22 °C, growth in the presence of 5 % NaCl, good viability after lyophilisation and in simulated gastric and small intestinal juice, antimicrobial activity against test pathogens, and good adhesive properties in vitro.

  8. Metabolic engineering of lactic acid bacteria for the production of nutraceuticals

    Hugenholtz, J.; Sybesma, W.; Groot, M.N.; Wisselink, W.; Ladero, V.; Burgess, K.; Sinderen, van D.; Piard, J.C.; Eggink, G.; Smid, E.J.; Savoy, G.; Sesma, F.; Jansen, T.; Hols, P.; Kleerebezem, M.

    2002-01-01

    Lactic acid bacteria display a relatively simple and well-described metabolism where the sugar source is converted mainly to lactic acid. Here we will shortly describe metabolic engineering strategies on the level of sugar metabolism, that lead to either the efficient re-routing of the lactococcal

  9. Treating Simple Tibia Fractures with Poly-DL-Lactic Acid Screw as a ...

    ) absorbable screw as a ... fractures. Keywords: Simple tibia fracture, Fracture healing time Poly-DL-lactic acid, Poly-DL-Lactic Acid, ..... bilateral cortex of the bone due to the weak anti- ... Hu YL, Yuan WQ, Wang LF, Liu HF, Jin D. A prospective.

  10. Characterization of anti-listerial lactic acid bacteria isolated from Thai fermented fish products

    Østergaard, Anya; Embarek, Peter Karim Ben; Wedell-Neergaard, C.

    1998-01-01

    Thai fermented fish products were screened for lactic acid bacteria capable of inhibiting Listeria sp. (Listeria innocua). Of 4150 assumed lactic acid bacteria colonies from MRS agar plates that were screened by an agar-overlay method 58 (1.4%) were positive. Forty four of these strains were...

  11. Influence of rice straw-derived dissolved organic matter on lactic acid fermentation by Rhizopus oryzae.

    Chen, Xingxuan; Wang, Xiahui; Xue, Yiyun; Zhang, Tian-Ao; Li, Yuhao; Hu, Jiajun; Tsang, Yiu Fai; Zhang, Hongsheng; Gao, Min-Tian

    2018-01-31

    Rice straw can be used as carbon sources for lactic acid fermentation. However, only a small amount of lactic acid is produced even though Rhizopus oryzae can consume glucose in rice straw-derived hydrolysates. This study correlated the inhibitory effect of rice straw with rice straw-derived dissolved organic matter (DOM). Lactic acid fermentations with and without DOM were conducted to investigate the effect of DOM on lactic acid fermentation by R. oryzae. Fermentation using control medium with DOM showed a similar trend to fermentation with rice straw-derived hydrolysates, showing that DOM contained the major inhibitor of rice straw. DOM assay indicated that it mainly consisted of polyphenols and polysaccharides. The addition of polyphenols and polysaccharides derived from rice straw confirmed that lactic acid fermentation was promoted by polysaccharides and significantly inhibited by polyphenols. The removal of polyphenols also improved lactic acid production. However, the loss of polysaccharides during the removal of polyphenols resulted in low glucose consumption. This study is the first to investigate the effects of rice straw-derived DOM on lactic acid fermentation by R. oryzae. The results may provide a theoretical basis for identifying inhibitors and promoters associated with lactic acid fermentation and for establishing suitable pretreatment methods. Copyright © 2018 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  12. Effect of different media on production of lactic acid from whey by ...

    Whey containing 50 g.l -1 lactose was fermented to lactic acid in batch process by Lactobacillus bulgaricus. The impact of 5 different media with change in volume percent of whey and nutrient was investigated at 32 ± 0.5°C. Substrate consumption and lactic acid production were determined at 0, 12, 24, 36, 48, 60 and 72 h.

  13. SLUG FLOW CAPILLARY MICROREACTORS FOR LACTIC ACID EXTRACTION: EXPERIMENTAL STUDY AND MASS TRANSFER MODELLING

    Susanti, Susanti; Winkelman, Jozef; Schuur, Boelo; Heeres, Hero; Yue, Jun

    2015-01-01

    Lactic acid is an important commercial product and has been widely used for manufacturing biodegradable polymer. Current method of lactic acid isolation from fermentation broths is energy intensive and leads to the formation of large amounts of salts. Reactive liquid-liquid extraction has been

  14. Lactic acid fermentation of two sorghum varieties is not affected by ...

    The study was conducted to investigate sorghum grain variety differences in lactic acid fermentation based on their differences in phenolic contents. The study wa s conductedas a 2 x 5 x 4 factorial design with three factors: Factor 1: Sorghum variety (white and red sorghum); Factor 2: Control treatment without lactic acid ...

  15. Hydrolytic breakdown of lactoferricin by lactic acid bacteria.

    Paul, Moushumi; Somkuti, George A

    2010-02-01

    Lactoferricin is a 25-amino acid antimicrobial peptide fragment that is liberated by pepsin digestion of lactoferrin present in bovine milk. Along with its antibacterial properties, lactoferricin has also been reported to have immunostimulatory, antiviral, and anticarcinogenic effects. These attributes provide lactoferricin and other natural bioactive peptides with the potential to be functional food ingredients that can be used by the food industry in a variety of applications. At present, commercial uses of these types of compounds are limited by the scarcity of information on their ability to survive food processing environments. We have monitored the degradation of lactoferricin during its incubation with two types of lactic acid bacteria used in the yogurt-making industry, Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus, with the aim of assessing the stability of this milk protein-derived peptide under simulated yogurt-making conditions. Analysis of the hydrolysis products isolated from these experiments indicates degradation of this peptide near neutral pH by lactic acid bacteria-associated peptidases, the extent of which was influenced by the bacterial strain used. However, the data also showed that compared to other milk-derived bioactive peptides that undergo complete degradation under these conditions, the 25-amino acid lactoferricin is apparently more resistant, with approximately 50% of the starting material remaining after 4 h of incubation. These findings imply that lactoferricin, as a natural milk protein-derived peptide, has potential applications in the commercial production of yogurt-like fermented dairy products as a multi-functional food ingredient.

  16. Bacteriocins produced by lactic acid bacteria: A review

    Vesković-Moračanin Slavica M.

    2014-01-01

    Full Text Available Lactic acid bacteria (LAB have an essential role in the production of fermented products. With their metabolic activity, they influence the ripening processes - leading to desired sensory qualities while at the same time inhibiting the growth of undesired microorganisms. Because of their dominant role during fermentation and because of a long tradition of utilization, Lhave been designated as “safe microbiota”. Biological protection of LAB, as a naturally present and/or selected and intentionally added microflora, is realized through the production of non-specific (lactic acid, acetic acid and other volatile organic acids, hydrogen peroxide, diacetyl, etc and specific metabolites, bacteriocins. Bacteriocins are extracellularly released proteins or peptides which possess certain antibacterial activity towards certain types of microorganisms, usually related to the producing bacteria. Today, bacteriocins represent a very interesting potential for their application in the food industry. Their application can reduce the use of synthetic preservatives and/or the intensity of thermal treatment during food production consumer’s need for safe, fresh and minimally-processed food. With the intention of realizing this potential to the fullest, it is necessary to understand the nature of bacteriocins, their production mechanisms, regulations and actions, as well as the influence of external factors on the their antimicrobial activity. The composition of food, i.e. its characteristics (pH, temperature, ingredients and additives, types and quantities of epiphytic microbiota and the actual technological process used in production, can all influence the stability and activity of the added bacteriocins. The future research in this field should also aim to clarify this unknown aspect of the application of bacteriocins, to provide the necessary knowledge about the optimization of the external conditions and open up the possibility of discovering their new

  17. Betaine and beet molasses enhance L-lactic acid production by Bacillus coagulans.

    Ke Xu

    Full Text Available Lactic acid is an important chemical with various industrial applications, and it can be efficiently produced by fermentation, in which Bacillus coagulans strains present excellent performance. Betaine can promote lactic acid fermentation as an effective osmoprotectant. Here, positive effect of betaine on fermentation by B. coagulans is revealed. Betaine could enhance lactic acid production by protecting l-LDH activity and cell growth from osmotic inhibition, especially under high glucose concentrations and with poor organic nitrogen nutrients. The fermentation with 0.05 g/L betaine could produce 17.9% more lactic acid compared to the fermentation without betaine. Beet molasses, which is rich in sucrose and betaine, was utilized in a co-feeding fermentation and raised the productivity by 22%. The efficient lactic acid fermentation by B. coagulans is thus developed by using betaine and beet molasses.

  18. Betaine and beet molasses enhance L-lactic acid production by Bacillus coagulans.

    Xu, Ke; Xu, Ping

    2014-01-01

    Lactic acid is an important chemical with various industrial applications, and it can be efficiently produced by fermentation, in which Bacillus coagulans strains present excellent performance. Betaine can promote lactic acid fermentation as an effective osmoprotectant. Here, positive effect of betaine on fermentation by B. coagulans is revealed. Betaine could enhance lactic acid production by protecting l-LDH activity and cell growth from osmotic inhibition, especially under high glucose concentrations and with poor organic nitrogen nutrients. The fermentation with 0.05 g/L betaine could produce 17.9% more lactic acid compared to the fermentation without betaine. Beet molasses, which is rich in sucrose and betaine, was utilized in a co-feeding fermentation and raised the productivity by 22%. The efficient lactic acid fermentation by B. coagulans is thus developed by using betaine and beet molasses.

  19. Metabolic strategies of beer spoilage lactic acid bacteria in beer.

    Geissler, Andreas J; Behr, Jürgen; von Kamp, Kristina; Vogel, Rudi F

    2016-01-04

    Beer contains only limited amounts of readily fermentable carbohydrates and amino acids. Beer spoilage lactic acid bacteria (LAB) have to come up with metabolic strategies in order to deal with selective nutrient content, high energy demand of hop tolerance mechanisms and a low pH. The metabolism of 26 LAB strains of 6 species and varying spoilage potentialwas investigated in order to define and compare their metabolic capabilities using multivariate statistics and outline possible metabolic strategies. Metabolic capabilities of beer spoilage LAB regarding carbohydrate and amino acids did not correlate with spoilage potential, but with fermentation type (heterofermentative/homofermentative) and species. A shift to mixed acid fermentation by homofermentative (hof) Pediococcus claussenii and Lactobacillus backii was observed as a specific feature of their growth in beer. For heterofermentative (hef) LAB a mostly versatile carbohydrate metabolism could be demonstrated, supplementing the known relevance of organic acids for their growth in beer. For hef LAB a distinct amino acid metabolism, resulting in biogenic amine production, was observed, presumably contributing to energy supply and pH homeostasis.

  20. Fermentation of aqueous plant seed extracts by lactic acid bacteria

    Schafner, D.W.; Beuchat, R.L.

    1986-05-01

    The effects of lactic acid bacterial fermentation on chemical and physical changes in aqueous extracts of cowpea (Vigna unguiculata), peanut (Arachis hypogea), soybean (Glycine max), and sorghum (Sorghum vulgare) were studied. The bacteria investigated were Lactobacillus helveticus, L. delbrueckii, L. casei, L. bulgaricus, L. acidophilus, and Streptococcus thermophilus. Organisms were inoculated individually into all of the seed extracts; L. bulgaricus and S. thermophilus were also evaluated together as inocula for fermenting the legume extracts. During fermentation, bacterial population and changes in titratable acidity, pH, viscosity, and color were measured over a 72 h period at 37 degrees C. Maximum bacterial populations, titratable acidity, pH, and viscosity varied depending upon the type of extract and bacterial strain. The maximum population of each organism was influenced by fermentable carbohydrates, which, in turn, influenced acid production and change in pH. Change in viscosity was correlated with the amount of protein and titratable acidity of products. Color was affected by pasteurization treatment and fermentation as well as the source of extract. In the extracts inoculated simultaneously with L. bulgaricus and S. thermophilus, a synergistic effect resulted in increased bacterial populations, titratable acidity, and viscosity, and decreased pH in all the legume extracts when compared to the extracts fermented with either of these organisms individually. Fermented extracts offer potential as substitutes for cultured dairy products. 24 references.

  1. A perspective on Serum Lactic acid, Lactic Acidosis in a Critical Care Unit

    Agela A.Elbadri

    2013-06-01

    Full Text Available Breast cancer is one of the major surgical problems encountered in Libya. Lactic acidosis is a universal complication in breast cancer patients and can be considered a possible prognostic marker. Therefore, it will be beneficial to correctly understand and review the biochemistry underlying lactic acidosis and its possible significance as a prognostic marker in critical care patients, including breast cancer.

  2. The influence of brewers' yeast addition on lactic acid fermentation of brewers' spent grain hydrolysate by Lactobacillus rhamnosus

    Pejin, Jelena; Radosavljević, Miloš; Kocić-Tanackov, Sunčica; Đukić-Vuković, Aleksandra; Mladenović, Dragana; Mojović, Ljiljana

    2015-01-01

    In this study brewers' spent grain (BSG) hydrolysate was produced using optimal conditions. Hydrolysates were used for lactic acid fermentation by Lactobacillus rhamnosus ATCC 7469. The aim of this study was to evaluate possibilities of the BSG hydrolysate utilization as a substrate for lactic acid fermentation as well as the effect of dry brewers' yeast (1.0, 3.0, and 5.0 %) addition in hydrolysate on lactic acid fermentation parameters (L-(+)-lactic acid and reducing sugars concentration an...

  3. Leuconostoc Strains Unable to Split a Lactose Analogue Revealed by Characterisation of Mesophilic Dairy Starters

    Maarit Mäki

    2005-01-01

    Full Text Available Mesophilic starter cultures used in dairy industry have been traditionally characterised by metabolic and biochemical methods. As closely related species of lactic acid bacteria have often only minor differences in phenotypic traits, which may also be variable within certain species, clear identification is often complicated. Therefore, techniques of molecular biology have been applied for rapid detection and differentiation of lactic acid bacteria. In this work, some bacterial clones isolated from mesophilic starters, which were preliminary identified as lactococci by phenotypic methods, were found to be Leuconostoc strains by both PCR and PFGE. According to the results, genotypic differentiation methods used in combination with phenotypic tests provide a fast and convenient way to reliably identify lactic acid bacteria displaying atypical metabolic characteristics.

  4. M2-like macrophage polarization in high lactic acid-producing head and neck cancer.

    Ohashi, Toshimitsu; Aoki, Mitsuhiro; Tomita, Hiroyuki; Akazawa, Takashi; Sato, Katsuya; Kuze, Bunya; Mizuta, Keisuke; Hara, Akira; Nagaoka, Hitoshi; Inoue, Norimitsu; Ito, Yatsuji

    2017-06-01

    Reprogramming of glucose metabolism in tumor cells is referred to as the Warburg effect and results in increased lactic acid secretion into the tumor microenvironment. We have previously shown that lactic acid has important roles as a pro-inflammatory and immunosuppressive mediator and promotes tumor progression. In this study, we examined the relationship between the lactic acid concentration and expression of LDHA and GLUT1, which are related to the Warburg effect, in human head and neck squamous cell carcinoma (HNSCC). Tumors expressing lower levels of LDHA and GLUT1 had a higher concentration of lactic acid than those with higher LDHA and GLUT1 expression. Lactic acid also suppressed the expression of LDHA and GLUT1 in vitro. We previously reported that lactic acid enhances expression of an M2 macrophage marker, ARG1, in murine macrophages. Therefore, we investigated the relationship between the lactic acid concentration and polarization of M2 macrophages in HNSCC by measuring the expression of M2 macrophage markers, CSF1R and CD163, normalized using a pan-macrophage marker, CD68. Tumors with lower levels of CD68 showed a higher concentration of lactic acid, whereas those with higher levels of CSF1R showed a significantly higher concentration of lactic acid. A similar tendency was observed for CD163. These results suggest that tumor-secreted lactic acid is linked to the reduction of macrophages in tumors and promotes induction of M2-like macrophage polarization in human HNSCC. © 2017 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

  5. D-Lactic acid biosynthesis from biomass-derived sugars via Lactobacillus delbrueckii fermentation.

    Zhang, Yixing; Vadlani, Praveen V

    2013-12-01

    Poly-lactic acid (PLA) derived from renewable resources is considered to be a good substitute for petroleum-based plastics. The number of poly L-lactic acid applications is increased by the introduction of a stereocomplex PLA, which consists of both poly-L and D-lactic acid and has a higher melting temperature. To date, several studies have explored the production of L-lactic acid, but information on biosynthesis of D-lactic acid is limited. Pulp and corn stover are abundant, renewable lignocellulosic materials that can be hydrolyzed to sugars and used in biosynthesis of D-lactic acid. In our study, saccharification of pulp and corn stover was done by cellulase CTec2 and sugars generated from hydrolysis were converted to D-lactic acid by a homofermentative strain, L. delbrueckii, through a sequential hydrolysis and fermentation process (SHF) and a simultaneous saccharification and fermentation process (SSF). 36.3 g L(-1) of D-lactic acid with 99.8 % optical purity was obtained in the batch fermentation of pulp and attained highest yield and productivity of 0.83 g g(-1) and 1.01 g L(-1) h(-1), respectively. Luedeking-Piret model described the mixed growth-associated production of D-lactic acid with a maximum specific growth rate 0.2 h(-1) and product formation rate 0.026 h(-1), obtained for this strain. The efficient synthesis of D-lactic acid having high optical purity and melting point will lead to unique stereocomplex PLA with innovative applications in polymer industry.

  6. Amino acid catabolism and generation of volatiles by lactic acid bacteria

    Tavaria, F. K.; Dahl, S.; Carballo, F. J.; Malcata, F. X.

    2002-01-01

    Twelve isolates of lactic acid bacteria, belonging to the Lactobacillus, Lactococcus, Leuconostoc, and Enterococcus genera, were previously isolated from 180- d-old Serra da Estrela cheese, a traditional Portuguese cheese manufactured from raw milk and coagulated with a plant rennet. These isolates were subsequently tested for their ability to catabolize free amino acids, when incubated independently with each amino acid in free form or with a mixture thereof. Attempts...

  7. Efficient production of l-lactic acid by an engineered Thermoanaerobacterium aotearoense with broad substrate specificity

    2013-01-01

    Background Efficient conversion of lignocellulosic biomass to optically pure lactic acid is a key challenge for the economical production of biodegradable poly-lactic acid. A recently isolated strain, Thermoanaerobacterium aotearoense SCUT27, is promising as an efficient lactic acid production bacterium from biomass due to its broad substrate specificity. Additionally, its strictly anaerobic and thermophilic characteristics suppress contamination from other microoragnisms. Herein, we report the significant improvements of concentration and yield in lactic acid production from various lignocellulosic derived sugars, achieved by the carbon flux redirection through homologous recombination in T. aotearoense SCUT27. Results T. aotearoense SCUT27 was engineered to block the acetic acid formation pathway to improve the lactic acid production. The genetic manipulation resulted in 1.8 and 2.1 fold increase of the lactic acid yield using 10 g/L of glucose or 10 g/L of xylose as substrate, respectively. The maximum l-lactic acid yield of 0.93 g/g glucose with an optical purity of 99.3% was obtained by the engineered strain, designated as LA1002, from 50 g/L of substrate, which is very close to the theoretical value (1.0 g/g of glucose). In particular, LA1002 produced lactic acid at an unprecedented concentration up to 3.20 g/L using 10 g/L xylan as the single substrate without any pretreatment after 48 h fermentation. The non-sterilized fermentative production of l-lactic acid was also carried out, achieving values of 44.89 g/L and 0.89 g/g mixed sugar for lactic acid concentration and yield, respectively. Conclusions Blocking acetic acid formation pathway in T. aotearoense SCUT27 increased l-lactic acid production and yield dramatically. To our best knowledge, this is the best performance of fermentation on lactic acid production using xylan as the sole carbon source, considering the final concentration, yield and fermentation time. In addition, it should be

  8. Core Fluxome and Metafluxome of Lactic Acid Bacteria under Simulated Cocoa Pulp Fermentation Conditions

    Adler, Philipp; Bolten, Christoph Josef; Dohnt, Katrin; Hansen, Carl Erik

    2013-01-01

    In the present work, simulated cocoa fermentation was investigated at the level of metabolic pathway fluxes (fluxome) of lactic acid bacteria (LAB), which are typically found in the microbial consortium known to convert nutrients from the cocoa pulp into organic acids. A comprehensive 13C labeling approach allowed to quantify carbon fluxes during simulated cocoa fermentation by (i) parallel 13C studies with [13C6]glucose, [1,2-13C2]glucose, and [13C6]fructose, respectively, (ii) gas chromatography-mass spectrometry (GC/MS) analysis of secreted acetate and lactate, (iii) stoichiometric profiling, and (iv) isotopomer modeling for flux calculation. The study of several strains of L. fermentum and L. plantarum revealed major differences in their fluxes. The L. fermentum strains channeled only a small amount (4 to 6%) of fructose into central metabolism, i.e., the phosphoketolase pathway, whereas only L. fermentum NCC 575 used fructose to form mannitol. In contrast, L. plantarum strains exhibited a high glycolytic flux. All strains differed in acetate flux, which originated from fractions of citrate (25 to 80%) and corresponding amounts of glucose and fructose. Subsequent, metafluxome studies with consortia of different L. fermentum and L. plantarum strains indicated a dominant (96%) contribution of L. fermentum NCC 575 to the overall flux in the microbial community, a scenario that was not observed for the other strains. This highlights the idea that individual LAB strains vary in their metabolic contribution to the overall fermentation process and opens up new routes toward streamlined starter cultures. L. fermentum NCC 575 might be one candidate due to its superior performance in flux activity. PMID:23851099

  9. Cascade Production of Lactic Acid from Universal Types of Sugars Catalyzed by Lanthanum Triflate.

    Liu, Dajiang; Kim, Kwang Ho; Sun, Jian; Simmons, Blake A; Singh, Seema

    2018-02-09

    Lignocellulosic biomass conversion into value-added platform chemicals in the non-toxic, water-tolerant Lewis acid, and water solutions bears the hallmark of green chemistry. Lactic acid derived from biomass is an important chemical building block for biodegradable polymers such as polylactide. Herein, a universal method of converting lignocellulosic sugars into lactic acid using catalytic amount of water-stable Lewis acid La(OTf) 3 is demonstrated. The lignocellulosic sugars studied in this work include 1) pyrolytic sugars from pyrolysis oil, and 2) sugars derived from ionic liquid (IL)-pretreated biomass. Under moderate conditions (250 °C, 1 h), levoglucosan (major pyrolytic sugar), glucose, and xylose were converted into lactic acid with carbon-based molar yields of 75, 74, and 61 %, respectively. Furthermore, roughly 49 mol % (based on levoglucosan) and 74 wt % (relative to pretreated biomass) of lactic acid were obtained from the conversion of pyrolytic sugars and sugar-rich fraction after lignin removal from switchgrass, respectively. To our knowledge, this is the first reported conversion of pyrolytic sugar into lactic acid by chemocatalysis and also lignocellulosic sugars are converted into lactic acid without hydrolysis. This approach could potentially be extended to other lignocellulosic sugars after simple removal of lignin from biomass pretreatment, rendering moderate to high yields of lactic acid. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Anaerobic conversion of lactic acid to acetic acid and 1,2-propanediol by Lactobacillus buchneri

    Elferink, SJWHO; Krooneman, J; Gottschal, JC; Spoelstra, SF; Faber, F; Driehuis, F

    The degradation of lactic acid under anoxic conditions was studied in several strains of Lactobacillus buchneri and in close relatives such as Lactobacillus parabuchneri, Lactobacillus kefir, and Lactobacillus hilgardii. Of these lactobacilli, L. buchneri and L. parabuchneri were able to degrade

  11. Anaerobic conversion of lactic acid to acetic acid and 1,2-propanediol by Lactobacillus buchneri

    Elferink, S.; Krooneman, J.; Gottschal, J.C.; Spoelstra, S.F.; Faber, F.; Driehuis, F.

    2001-01-01

    The degradation of lactic acid under anoxic conditions was studied in several strains of Lactobacillus buchneri and in close relatives such as Lactobacillus parabuchneri, Lactobacillus kefir, and Lactobacillus hilgardii. Of these lactobacilli, L. buchneri and L. parabuchneri were able to degrade

  12. Nanosized Minicells Generated by Lactic Acid Bacteria for Drug Delivery

    Huu Ngoc Nguyen

    2017-01-01

    Full Text Available Nanotechnology has the ability to target specific areas of the body, controlling the drug release and significantly increasing the bioavailability of active compounds. Organic and inorganic nanoparticles have been developed for drug delivery systems. Many delivery systems are through clinical stages for development and market. Minicell, a nanosized cell generated by bacteria, is a potential particle for drug delivery because of its size, safety, and biodegradability. Minicells produced by bacteria could drive therapeutic agents against cancer, microbial infection, and other diseases by targeting. In addition, minicells generated by lactic acid bacteria being probiotics are more interesting than others because of their benefits like safety, immunological improvement, and biodegradation. This review aims to highlight the stages of development of nanoparticle for drug delivery and discuss their advantages and limitations to clarify minicells as a new opportunity for the development of potential nanoparticle for drug delivery.

  13. NANOCOMPOSITES OF POLY(LACTIC ACID REINFORCED WITH CELLULOSE NANOFIBRILS

    Liping Zhang

    2010-06-01

    Full Text Available A chemo-mechanical method was used to prepare cellulose nanofibrils dispersed uniformly in an organic solvent. Poly(ethylene glycol (PEG 1000 was added to the matrix as a compatibilizer to improve the interfacial interaction between the hydrophobic poly(lactic acid (PLA and the hydrophilic cellulose nanofibrils. The composites obtained by solvent casting methods from N,N-Dimethylacetamide (DMAc were characterized by tensile testing machine, atomic force microscope (AFM, scanning electron microscope (SEM, and Fourier transform infrared spectroscopy (FT-IR. The tensile test results indicated that, by adding PEG to the PLA and the cellulose nanofibrils matrix, the tensile strength and the elongation rate increased by 56.7% and 60%, respectively, compared with the PLA/cellulose nanofibrils composites. The FT-IR analysis successfully showed that PEG improved the intermolecular interaction, which is based on the existence of inter-molecular hydrogen bonding among PLA, PEG, and cellulose nanofibrils.

  14. Temperature dependence of poly(lactic acid) mechanical properties

    Zhou, Chengbo; Guo, Huilong; Li, Jingqing

    2016-01-01

    The mechanical properties of polymers are not only determined by their structures, but also related to the temperature field in which they are located. The yield behaviors, Young's modulus and structures of injection-molded poly(lactic acid) (PLA) samples after annealing at different temperatures....... The crystallinity increases with increasing annealing temperature and a' form crystal is formed when the annealing temperature is higher than 100 oC. The stretched samples with low crystallinity show the first yield at draw temperatures below the glass transition temperature (Tg) and the second yield above Tg....... For the samples annealed between 80 and 120 oC, a peculiar double yield appears when stretched within 50–60 oC and only the first or the second yield can be found at the lower and higher draw temperatures. The yield strain and yield stress together with Young's modulus were obtained and discussed in terms...

  15. Genomics of lactic acid bacteria: Current status and potential applications.

    Wu, Chongde; Huang, Jun; Zhou, Rongqing

    2017-08-01

    Lactic acid bacteria (LAB) are widely used for the production of a variety of foods and feed raw materials where they contribute to flavor and texture of the fermented products. In addition, specific LAB strains are considered as probiotic due to their health-promoting effects in consumers. Recently, the genome sequencing of LAB is booming and the increased amount of published genomics data brings unprecedented opportunity for us to reveal the important traits of LAB. This review describes the recent progress on LAB genomics and special emphasis is placed on understanding the industry-related physiological features based on genomics analysis. Moreover, strategies to engineer metabolic capacity and stress tolerance of LAB with improved industrial performance are also discussed.

  16. A Glutamic Acid-Producing Lactic Acid Bacteria Isolated from Malaysian Fermented Foods

    Zareian, Mohsen; Ebrahimpour, Afshin; Bakar, Fatimah Abu; Mohamed, Abdul Karim Sabo; Forghani, Bita; Ab-Kadir, Mohd Safuan B.; Saari, Nazamid

    2012-01-01

    l-glutamaic acid is the principal excitatory neurotransmitter in the brain and an important intermediate in metabolism. In the present study, lactic acid bacteria (218) were isolated from six different fermented foods as potent sources of glutamic acid producers. The presumptive bacteria were tested for their ability to synthesize glutamic acid. Out of the 35 strains showing this capability, strain MNZ was determined as the highest glutamic-acid producer. Identification tests including 16S rRNA gene sequencing and sugar assimilation ability identified the strain MNZ as Lactobacillus plantarum. The characteristics of this microorganism related to its glutamic acid-producing ability, growth rate, glucose consumption and pH profile were studied. Results revealed that glutamic acid was formed inside the cell and excreted into the extracellular medium. Glutamic acid production was found to be growth-associated and glucose significantly enhanced glutamic acid production (1.032 mmol/L) compared to other carbon sources. A concentration of 0.7% ammonium nitrate as a nitrogen source effectively enhanced glutamic acid production. To the best of our knowledge this is the first report of glutamic acid production by lactic acid bacteria. The results of this study can be further applied for developing functional foods enriched in glutamic acid and subsequently γ-amino butyric acid (GABA) as a bioactive compound. PMID:22754309

  17. Opportunities, perspectives and limits in lactic acid production from waste and industrial by-products

    Mladenović Dragana D.

    2016-01-01

    Full Text Available In line with the goals of sustainable development and environmental protection today great attention is directed towards new technologies for waste and industrial by-products utilization. Waste products represent potentially good raw material for production other valuable products, such as bioethanol, biogas, biodiesel, organic acids, enzymes, microbial biomass, etc. Since the first industrial production to the present, lactic acid has found wide application in food, cosmetic, pharmaceutical and chemical industries. In recent years, the demand for lactic acid has been increasing considerably owing to its potential use as a monomer for the production of poly-lactic acid (PLA polymers which are biodegradable and biocompatible with wide applications. Waste and industrial by-products such are whey, molasses, stillage, waste starch and lignocellulosic materials are a good source of fermentable sugars and many other substances of great importance for the growth of microorganisms, such as proteins, minerals and vitamins. Utilization of waste products for production of lactic acid could help to reduce the total cost of lactic acid production and except the economic viability of the process offers a solution of their disposal. Fermentation process depends on chemical and physical nature of feedstocks and the lactic acid producer. This review describes the characteristics, abilities and limits of microorganisms involved in lactic acid production, as well as the characteristics and types of waste products for lactic acid production. The fermentation methods that have been recently reported to improve lactic acid production are summarized and compared. In order to improve processes and productivity, fed-batch fermentation, fermentation with immobilized cell systems and mixed cultures and opportunities of open (non-sterilized fermentation have been investigated.

  18. Use of Protein Hydrolysates in Industrial Starter Culture Fermentations

    Ummadi, Madhavi (Soni); Curic-Bawden, Mirjana

    Lactic acid bacteria (LAB) have been used as starter cultures for fermenting foods long before the importance of microorganisms were recognized. The most important group of LAB are the lactococci, lactobacilli, streptococci, and pediococci. Additionally, bifidobacteria have been included as a probiotic, providing added value to the product. Since the genera involved are so diverse, the nutritional requirements (energy, carbon and nitrogen sources) differ significantly between and within species. Designing an optimum fermentation medium for production of active and vigorous LAB starter cultures and probiotics requires selecting the right raw ingredients, especially protein hydrolysates that can provide adequate nutrients for growth and viability. This chapter attempts to describe the application of various commercial protein hydrolysates used for production of dairy and meat starter cultures, with special emphasis on meeting the nitrogen requirements of industrially important LAB species.

  19. Highly efficient production of D-lactic acid from chicory-derived inulin by Lactobacillus bulgaricus.

    Xu, Qianqian; Zang, Ying; Zhou, Jie; Liu, Peng; Li, Xin; Yong, Qiang; Ouyang, Jia

    2016-11-01

    Inulin is a readily available feedstock for cost-effective production of biochemicals. To date, several studies have explored the production of bioethanol, high-fructose syrup and fructooligosaccharide, but there are no studies regarding the production of D-lactic acid using inulin as a carbon source. In the present study, chicory-derived inulin was used for D-lactic acid biosynthesis by Lactobacillus bulgaricus CGMCC 1.6970. Compared with separate hydrolysis and fermentation processes, simultaneous saccharification and fermentation (SSF) has demonstrated the best performance of D-lactic acid production. Because it prevents fructose inhibition and promotes the complete hydrolysis of inulin, the highest D-lactic acid concentration (123.6 ± 0.9 g/L) with a yield of 97.9 % was obtained from 120 g/L inulin by SSF. Moreover, SSF by L. bulgaricus CGMCC 1.6970 offered another distinct advantage with respect to the higher optical purity of D-lactic acid (>99.9 %) and reduced number of residual sugars. The excellent performance of D-lactic acid production from inulin by SSF represents a high-yield method for D-lactic acid production from non-food grains.

  20. The effect of delignification process with alkaline peroxide on lactic acid production from furfural residues

    Yong Tang

    2012-11-01

    Full Text Available Furfural residues produced from the furfural industry were investigated as a substrate for lactic acid production by simultaneous saccharification and fermentation (SSF. Alkaline peroxide was used for delignification of furfural residues to improve the final lactic acid concentration. The residue was treated with 1.3% to 1.7% hydrogen peroxide at 80 °C for 1 h with a substrate concentration of 3.33%. SSF of furfural residues with different delignification degrees were carried out to evaluate the effect of delignification degree on lactic acid production. Using corn hydrolysates/ furfural residues as substrates, SSF with different media were carried out to investigate the effect of lignin on the interaction between enzymes and lactic acid bacteria. Lactic acid bacteria had a negative effect on cellulase, thus resulting in the reduction of enzyme activity. Lignin and nutrients slowed down the decreasing trend of enzyme activity. A higher delignification resulted in a slower fermentation rate and lower yield due to degradation products of lignin and the effect of lignin on the interaction between enzymes and lactic acid bacteria. For the purpose of lactic acid production, a moderate delignification (furfural residues with the lignin content of 14.8% was optimum.

  1. Monascus ruber as cell factory for lactic acid production at low pH.

    Weusthuis, Ruud A; Mars, Astrid E; Springer, Jan; Wolbert, Emil Jh; van der Wal, Hetty; de Vrije, Truus G; Levisson, Mark; Leprince, Audrey; Houweling-Tan, G Bwee; Pha Moers, Antoine; Hendriks, Sjon Na; Mendes, Odette; Griekspoor, Yvonne; Werten, Marc Wt; Schaap, Peter J; van der Oost, John; Eggink, Gerrit

    2017-07-01

    A Monascus ruber strain was isolated that was able to grow on mineral medium at high sugar concentrations and 175g/l lactic acid at pH 2.8. Its genome and transcriptomes were sequenced and annotated. Genes encoding lactate dehydrogenase (LDH) were introduced to accomplish lactic acid production and two genes encoding pyruvate decarboxylase (PDC) were knocked out to subdue ethanol formation. The strain preferred lactic acid to glucose as carbon source, which hampered glucose consumption and therefore also lactic acid production. Lactic acid consumption was stopped by knocking out 4 cytochrome-dependent LDH (CLDH) genes, and evolutionary engineering was used to increase the glucose consumption rate. Application of this strain in a fed-batch fermentation resulted in a maximum lactic acid titer of 190g/l at pH 3.8 and 129g/l at pH 2.8, respectively 1.7 and 2.2 times higher than reported in literature before. Yield and productivity were on par with the best strains described in literature for lactic acid production at low pH. Copyright © 2017 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  2. Stimulation of Lactic Acid Bacteria by a Micrococcus Isolate: Evidence for Multiple Effects

    Nath, K. R.; Wagner, B. J.

    1973-01-01

    Growth of, and rate of acid production by, six cultures of lactic acid bacteria were increased in the presence of Micrococcus isolate F4 or a preparation of its capsular material. Concentrations of hydrogen peroxide found in pure cultures of the lactic acid bacteria were not detectable, or were greatly reduced, in mixed culture with Micrococcus isolate F4. The capsular material was not as effective as whole cells in preventing accumulation of H2O2. Catalase stimulated growth of, and the rate of acid production by, the lactic acid bacteria, but not to the same extent as Micrococcus isolate F4 in some cultures. The existence of two mechanisms for micrococcal stimulation of the lactic acid bacteria is postulated. One mechanism involves removal of H2O2; the other has not been characterized. PMID:4199337

  3. Antimicrobial potential of triticale stillage after lactic acid fermentation with Lactobacillus fermentum PL-1

    Kujundžić Žužana; Dimić Gordana R.; Markov Siniša L.; Kocić-Tanackov Sunčica D.; Mojović Ljiljana V.; Pejin Jelena D.; Marković Milica N.

    2013-01-01

    This study is concerned with the testing of antimicrobial activity of triticale stillage obtained after lactic fermentation by Lactobacillus fermentum PL-1. The antimicrobial tests were performed using the disc-diffusion and agar well diffusion methods. It was found that fermented triticale stillage after lactic acid fermentation exhibited an inhibitory effect towards tested Gram positive and Gram negative bacteria: Escherichia coli, Salmonella enteritidis,...

  4. Antimicrobial Activity and Chemical Composition of “Kpètè-Kpètè”: A Starter of Benin Traditional Beer Tchoukoutou

    N'tcha, Christine; Sina, Haziz; Kayodé, Adéchola Pierre Polycarpe; Gbenou, Joachim D.

    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. PMID:28367445

  5. Antimicrobial Activity and Chemical Composition of "Kpètè-Kpètè": A Starter of Benin Traditional Beer Tchoukoutou.

    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.

  6. Lactic acid levels in pleural fluid from patients with bacterial pleuritis.

    Riley, T V

    1985-01-01

    Pleural fluid lactic acid estimations were carried out on 60 samples by gas-liquid chromatography. Lactic acid levels in 12 patients with bacterial pleural infection were statistically significantly higher (mean, 287 mg/dl; range, 135 to 482 mg/dl) than in 18 patients with malignancy (mean, 71 mg/dl; range, 24 to 157 mg/dl) and 30 other patients with pleural effusions (mean, 19 mg/dl; range, 10 to 57 mg/dl). The determination of pleural fluid lactic acid may help in differentiating between em...

  7. Breeding L(+)-lactic acid high productive mutant from xylose by nitrogen ions

    Yang Yingge; Li Wen; Liu Dan; Fan Yonghong; Wang Dongmei; Zheng Zhiming; Yu Zengliang

    2007-01-01

    In order to obtain higher L(+)-lactic acid yield strain fermentating from xylose, the original strain Rhizopus oryzae RLC41-6 was mutated by 10keV N + ion implantation. A mutant strain RQ4012 was obtained. After 72h shake-flask cultivation, the concentration of L(+)-lactic acid reached 74.37g/L, and the productivity was 1.03g/(L.h). Its lactic acid yield was 160% higher than that of the original one, and the mutant strain has high genetic stability. (authors)

  8. pH-, Lactic acid-, and non-lactic acid-dependent activities of probiotic Lactobacilli against Salmonella enterica Serovar Typhimurium.

    Fayol-Messaoudi, Domitille; Berger, Cédric N; Coconnier-Polter, Marie-Hélène; Liévin-Le Moal, Vanessa; Servin, Alain L

    2005-10-01

    The mechanism(s) underlying the antibacterial activity of probiotic Lactobacillus strains appears to be multifactorial and includes lowering of the pH and the production of lactic acid and of antibacterial compounds, including bacteriocins and nonbacteriocin, non-lactic acid molecules. Addition of Dulbecco's modified Eagle's minimum essential medium to the incubating medium delays the killing activity of lactic acid. We found that the probiotic strains Lactobacillus johnsonii La1, Lactobacillus rhamnosus GG, Lactobacillus casei Shirota YIT9029, L. casei DN-114 001, and L. rhamnosus GR1 induced a dramatic decrease in the viability of Salmonella enterica serovar Typhimurium SL1344 mainly attributable to non-lactic acid molecule(s) present in the cell-free culture supernatant (CFCS). These molecules were more active against serovar Typhimurium SL1344 in the exponential growth phase than in the stationary growth phase. We also showed that the production of the non-lactic acid substance(s) responsible for the killing activity was dependent on growth temperature and that both unstable and stable substances with killing activity were present in the CFCSs. We found that the complete inhibition of serovar Typhimurium SL1344 growth results from a pH-lowering effect.

  9. Towards the development of a common starter culture for fufu and usi (edible starch: Screening for potential starters

    Kubrat A. Oyinlola

    2016-04-01

    Full Text Available Fermented cassava products like fufu and usi are important staple foods in many African homes. Natural fermentation time is usually long resulting in slower acidification and inconsistent nutritional composition of products which could be overcome with the use of starter culture. However, most available starters are used for single food fermentation and are uneconomical. This necessitates the development of a starter culture for multiple related food products to reduce cost. Hence, this study aimed at screening for potential starters in the development of a common starter culture for fufu and usi.Fresh, peeled, chipped and grated cassava tubers were spontaneously fermented and lactic acid bacteria were isolated from the fermenting mash at 24 hour intervals. Ninety eight (98 isolates were randomly picked. Lactobacillus plantarum had highest occurrence (50.0% in both fermentations.All selected isolates did not hydrolyze starch, but produced linamarase and pectinase. Fermenting pH ranged between 6.50 and 3.58 during 72 hours fermentation. Lactic acid concentration ranged from 1.10 g/L to 1.78 g/L at 24 hours, 1.22 g/L to 2.45 g/L at 48 hours and 0.57 g/L to 2.55 g/l at 72 hours. The highest hydrogen peroxide concentration produced was 629 µg/L at 24 hours while the least was 136 µg/L at 72 hours. 1.08 g/L of diacetyl was the least concentration produced at 24 hours while the highest was 2.86 g/L at 48 hours.Five potential starters were identified as Lactobacillus pentosus F2A, L. plantarum subsp. argentolarensis F2B, L. plantarum F2C, L. plantarum U2A and L. paraplantarum U2C.

  10. Amino acids analysis during lactic acid fermentation by single strain ...

    L. salivarius alone showed relatively good assimilation of various amino acids that existed at only a little amounts in MRS media (Asn, Asp, Cit, Cys, Glu, His, Lys, Orn, Phe, Pro, Tyr, Arg, Ile, Leu, Met, Ser, Thr, Trp and Val), whereas Ala and Gly accumulated in L. salivarius cultures. P. acidilactici, in contrast, hydrolyzed the ...

  11. Acid hydrolysis of Curcuma longa residue for ethanol and lactic acid fermentation.

    Nguyen, Cuong Mai; Nguyen, Thanh Ngoc; Choi, Gyung Ja; Choi, Yong Ho; Jang, Kyoung Soo; Park, Youn-Je; Kim, Jin-Cheol

    2014-01-01

    This research examines the acid hydrolysis of Curcuma longa waste, to obtain the hydrolysate containing lactic acid and ethanol fermentative sugars. A central composite design for describing regression equations of variables was used. The selected optimum condition was 4.91% sulphuric acid, 122.68°C and 50 min using the desirability function under the following conditions: the maximum reducing sugar (RS) yield is within the limited range of the 5-hydroxymethylfurfural (HMF) and furfural concentrations. Under the condition, the obtained solution contained 144 g RS/L, 0.79 g furfural/L and 2.59 g HMF/L and was directly fermented without a detoxification step. The maximum product concentration, average productivity, RS conversion and product yield were 115.36 g/L, 2.88 g/L/h, 89.43% and 64% for L-lactic acid; 113.92 g/L, 2.59 g/L/h, 88.31% and 63.29% for D-lactic acid; and 55.03 g/L, 1.38 g/L/h, 42.66 and 30.57%, respectively, for ethanol using a 7-L jar fermenter. Copyright © 2013. Published by Elsevier Ltd.

  12. Key volatile aroma compounds of lactic acid fermented malt based beverages - impact of lactic acid bacteria strains.

    Nsogning Dongmo, Sorelle; Sacher, Bertram; Kollmannsberger, Hubert; Becker, Thomas

    2017-08-15

    This study aims to define the aroma composition and key aroma compounds of barley malt wort beverages produced from fermentation using six lactic acid bacteria (LAB) strains. Gas chromatography mass spectrometry-olfactometry and flame ionization detection was employed; key aroma compounds were determined by means of aroma extract dilution analysis. Fifty-six detected volatile compounds were similar among beverages. However, significant differences were observed in the concentration of individual compounds. Key aroma compounds (flavor dilution (FD) factors ≥16) were β-damascenone, furaneol, phenylacetic acid, 2-phenylethanol, 4-vinylguaiacol, sotolon, methional, vanillin, acetic acid, nor-furaneol, guaiacol and ethyl 2-methylbutanoate. Furthermore, acetaldehyde had the greatest odor activity value of up to 4266. Sensory analyses revealed large differences in the flavor profile. Beverage from L. plantarum Lp. 758 showed the highest FD factors in key aroma compounds and was correlated to fruity flavors. Therefore, we suggest that suitable LAB strain selection may improve the flavor of malt based beverages. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Biodegradation of flax fiber reinforced poly lactic acid

    2010-07-01

    Full Text Available Woven and nonwoven flax fiber reinforced poly lactic acid (PLA biocomposites were prepared with amphiphilic additives as accelerator for biodegradation. The prepared composites were buried in farmland soil for biodegradability studies. Loss in weight of the biodegraded composite samples was determined at different time intervals. The surface morphology of the biodegraded composites was studied with scanning electron microscope (SEM. Results indicated that in presence of mandelic acid, the composites showed accelerated biodegradation with 20–25% loss in weight after 50–60 days. On the other hand, in presence of dicumyl peroxide (as additive, biodegradation of the composites was relatively slow as confirmed by only 5–10% loss in weight even after 80–90 days. This was further confirmed by surface morphology of the biodegraded composites. We have attempted to show that depending on the end uses, we can add different amphiphilic additives for delayed or accelerated biodegradability. This work gives us the idea of biodegradation of materials from natural fiber reinforced PLA composites when discarded carelessly in the environment instead of proper waste disposal site.

  14. Microbiota dynamics related to environmental conditions during the fermentative production of Fen-Daqu, a Chinese industrial fermentation starter

    Zheng, X.; Yan, Z.; Nout, M.J.R.; Smid, E.J.; Zwietering, M.H.; Boekhout, T.; Han, J.S.; Han, B.

    2014-01-01

    Chinese Daqu is used as a starter for liquor and vinegar fermentations. It is produced by solid state fermentation of cereal–pulse mixtures. A succession of fungi, lactic acid bacteria and Bacillus spp. was observed during the production of Daqu. Mesophilic bacteria followed by fungi, dominated the

  15. Microbiota dynamics related to environmental conditions during the fermentative production of Fen-Daqu, a Chinese industrial fermentation starter

    Zheng, Xiao-Wei; Yan, Zheng; Nout, M J Robert; Smid, Eddy J; Zwietering, Marcel H; Boekhout, Teun; Han, Jian-Shu; Han, Bei-Zhong

    2014-01-01

    Chinese Daqu is used as a starter for liquor and vinegar fermentations. It is produced by solid state fermentation of cereal-pulse mixtures. A succession of fungi, lactic acid bacteria and Bacillus spp. was observed during the production of Daqu. Mesophilic bacteria followed by fungi, dominated the

  16. Technological properties of bacteriocin-producing lactic acid bacteria isolated from Pico cheese an artisanal cow's milk cheese.

    Ribeiro, S C; Coelho, M C; Todorov, S D; Franco, B D G M; Dapkevicius, M L E; Silva, C C G

    2014-03-01

    Evaluate technologically relevant properties from bacteriocin-producing strains to use as starter/adjunct cultures in cheese making. Eight isolates obtained from Pico cheese produced in Azores (Portugal) were found to produce bacteriocins against Listeria monocytogenes and three isolates against Clostridium perfringens. They were identified as Lactococcus lactis and Enterococcus faecalis and submitted to technological tests: growth at different conditions of temperature and salt, acid production, proteolysis, lipolysis, coexistence, enzymatic profile and autolytic capacity. Safety evaluation was performed by evaluating haemolytic, gelatinase and DNase activity, resistance to antibiotics and the presence of virulence genes. Some isolates presented good technological features such as high autolytic activity, acid and diacetyl production. Lactococcus lactis was negative for all virulence genes tested and inhibit the growth of all Lactic acid bacteria (LAB) isolates. Enterococci were positive for the presence of some virulence genes, but none of the isolates were classified as resistant to important antibiotics. The bacteriocin-producing Lc. lactis present good potential for application in food as adjunct culture in cheese production. The study also reveals good technological features for some Enterococcus isolates. Bacteriocin-producing strains presented important technological properties to be exploited as new adjunct culture for the dairy industry, influencing flavour development and improve safety. © 2013 The Society for Applied Microbiology.

  17. Effect of Digestible Protein and Sulfur Amino Acids in Starter Diet on Performance and Small Intestinal (Jejunum Morphology of Broilers

    Avisa Akhavan khaleghi

    2016-04-01

    Full Text Available Introduction Protein is an essential constituent of all tissues of animal body and has major effect on growth performance of the bird. A better understanding of the nutritional requirements of amino acids allows a more precise nutrition, offering the possibility for the formulator to optimize the requirement of at least minimum levels of crude protein by essential amino acids requirements, generating better result and lower costs for the producer. Methionine + Cystine (total sulfur amino acid = TSSA perform a number of functions in enzyme reactions and protein synthesis. Methionine is an essential amino acid for poultry and has an important role as a precursor of Cystine. Methionine is usually the first limiting amino acid in most of the practical diets for broiler chicken. The efficiency of utilization of dietary nutrients partly depends on the development of the gastro intestinal tract. Material and methods A 2×3 factorial arrangement in a CRD experiment was conducted to study the effect of digestible protein (DP and sulfur amino acids (DSAA during the starter period on performance and small intestinal (jejunum villous morphology. A total number of 300 day-old Ross 308 male broiler chicks were randomly distributed to 30 groups with 10 chicks each. Treatments consisted of two dietary levels of DP (19.5 and 21.5% and three dietary levels of DSAA (0.94, 1.02 and 1.1% that were fed for 10 days. For Each group and treatment, Feed Intake (FI, Weight Gain (WG and Feed Conversion Ratio (FCR were calculated and all the data were statistically analyzed by the SAS software. Results and Discussions The effects of different levels of protein and digestible sulfur amino acids on the mean feed intake, feed conversion ratio and daily weight gain are shown in the Table 3. Increase in the percentage of digestible sulfur amino acids, increased the levels of feed intake and feed conversion ratio in the starter period but, had no effect on the WG. Adding the DSAA

  18. Transcriptional Response to Lactic Acid Stress in the Hybrid Yeast Zygosaccharomyces parabailii.

    Ortiz-Merino, Raúl A; Kuanyshev, Nurzhan; Byrne, Kevin P; Varela, Javier A; Morrissey, John P; Porro, Danilo; Wolfe, Kenneth H; Branduardi, Paola

    2018-03-01

    Lactic acid has a wide range of applications starting from its undissociated form, and its production using cell factories requires stress-tolerant microbial hosts. The interspecies hybrid yeast Zygosaccharomyces parabailii has great potential to be exploited as a novel host for lactic acid production, due to high organic acid tolerance at low pH and a fermentative metabolism with a high growth rate. Here we used mRNA sequencing (RNA-seq) to analyze Z. parabailii 's transcriptional response to lactic acid added exogenously, and we explore the biological mechanisms involved in tolerance. Z. parabailii contains two homeologous copies of most genes. Under lactic acid stress, the two genes in each homeolog pair tend to diverge in expression to a significantly greater extent than under control conditions, indicating that stress tolerance is facilitated by interactions between the two gene sets in the hybrid. Lactic acid induces downregulation of genes related to cell wall and plasma membrane functions, possibly altering the rate of diffusion of lactic acid into cells. Genes related to iron transport and redox processes were upregulated, suggesting an important role for respiratory functions and oxidative stress defense. We found differences in the expression profiles of genes putatively regulated by Haa1 and Aft1/Aft2, previously described as lactic acid responsive in Saccharomyces cerevisiae Furthermore, formate dehydrogenase ( FDH ) genes form a lactic acid-responsive gene family that has been specifically amplified in Z. parabailii in comparison to other closely related species. Our study provides a useful starting point for the engineering of Z. parabailii as a host for lactic acid production. IMPORTANCE Hybrid yeasts are important in biotechnology because of their tolerance to harsh industrial conditions. The molecular mechanisms of tolerance can be studied by analyzing differential gene expression under conditions of interest and relating gene expression patterns

  19. Engineering CRISPR interference system in Klebsiella pneumoniae for attenuating lactic acid synthesis.

    Wang, Jingxuan; Zhao, Peng; Li, Ying; Xu, Lida; Tian, Pingfang

    2018-04-05

    Klebsiella pneumoniae is a promising industrial species for bioproduction of bulk chemicals such as 1,3-propanediol, 2,3-butanediol and 3-hydroxypropionic acid (3-HP). However, lactic acid is a troublesome by-product when optimizing for 3-HP production. Therefore, it is highly desirable to minimize lactic acid. Here, we show that lactic acid synthesis can be largely blocked by an engineered CRISPR interference (CRISPRi) system in K. pneumoniae. EGFP was recruited as a reporter of this CRISPRi system. Fluorescence assay of this CRISPRi system showed that enhanced green fluorescent protein (EGFP) expression level was repressed by 85-90%. To further test this CRISPRi system, guide RNAs were designed to individually or simultaneously target four lactate-producing enzyme genes. Results showed that all lactate-producing enzyme genes were significantly repressed. Notably, D-lactate dehydrogenase (ldhA) was shown to be the most influential enzyme for lactic acid formation in micro-aerobic conditions, as inhibiting ldhA alone led to lactic acid level similar to simultaneously repressing four genes. In shake flask cultivation, the strain coexpressing puuC (an aldehyde dehydrogenase catalyzing 3-hydroxypropionaldehyde to 3-HP) and dCas9-sgRNA inhibiting ldhA produced 1.37-fold 3-HP relative to the reference strain. Furthermore, in bioreactor cultivation, this CRISPRi strain inhibiting ldhA produced 36.7 g/L 3-HP, but only generated 1 g/L lactic acid. Clearly, this engineered CRISPRi system largely simplified downstream separation of 3-HP from its isomer lactic acid, an extreme challenge for 3-HP bioprocess. This study offers a deep understanding of lactic acid metabolism in diverse species, and we believe that this CRISPRi system will facilitate biomanufacturing and functional genome studies of K. pneumoniae or beyond.

  20. Effect of different media on production of lactic acid from whey by ...

    STORAGESEVER

    2009-01-05

    Jan 5, 2009 ... protein and 0.06% fat constituting an inexpensive and nutritionally rich raw material, high production rate and high yield for lactic acid fermentation. ... not a milk component, but a fermentation metabolite generated by certain ...

  1. A study on the effect of parameters on lactic acid production from whey

    Taleghani Hamidreza Ghafouri

    2016-03-01

    Full Text Available In batch fermentation of whey, selection of suitable species at desired conditions such as substrate, product concentrations, temperature and inoculum size were investigated. Four Lactobacillus species and one Lactococcus species were screened for lactic acid production. Among them L. bulgaricus ATCC 11842 were selected for further studies. The optimal growth of the selected organism for variable size of inocula was examined. The results indicated that inoculum size had insignificant effect on the cell and lactic acid concentration. The effect of temperature was also studied at 32, 37, 42 and 47°C. Results showed that the concentration of cell dry weight increased with increment of temperature from 32 to 42°C. The maximum cell and lactic acid concentration was obtained at 42°C. The effect of initial substrate concentration on lactic acid production was also examined. The optimum initial lactose concentration was found to be 90 g/l.

  2. Lactic Acid Bacteria from Kefir Increase Cytotoxicity of Natural Killer Cells to Tumor Cells.

    Yamane, Takuya; Sakamoto, Tatsuji; Nakagaki, Takenori; Nakano, Yoshihisa

    2018-03-27

    The Japanese fermented beverage, homemade kefir, contains six lactic acid bacteria: Lactococcus. lactis subsp. Lactis , Lactococcus . lactis subsp. Cremoris , Lactococcus. Lactis subsp. Lactis biovar diacetylactis , Lactobacillus plantarum , Leuconostoc meseuteroides subsp. Cremoris and Lactobacillus casei . In this study, we found that a mixture of the six lactic acid bacteria from kefir increased the cytotoxicity of human natural killer KHYG-1 cells to human chronic myelogenous leukemia K562 cells and colorectal tumor HCT116 cells. Furthermore, levels of mRNA expression and secretion of IFN-γ (interferon gamma) increased in KHYG-1 cells that had been treated with the six lactic acid bacteria mixture from kefir. The results suggest that the six lactic acid bacteria mixture from kefir has strong effects on natural immunity and tumor cell cytotoxicity.

  3. Lactic acid production from Cellobiose and xylose by engineered Saccharomyces cerevisiae

    Efficient and rapid production of value-added chemicals from lignocellulosic biomass is an important step towards a sustainable society. Lactic acid, used for synthesizing the bioplastic polylactide, has been produced by microbial fermentation using primarily glucose. Lignocellulosic hydrolysates co...

  4. Lactic Acid Bacteria from Kefir Increase Cytotoxicity of Natural Killer Cells to Tumor Cells

    Takuya Yamane

    2018-03-01

    Full Text Available The Japanese fermented beverage, homemade kefir, contains six lactic acid bacteria: Lactococcus. lactis subsp. Lactis, Lactococcus. lactis subsp. Cremoris, Lactococcus. Lactis subsp. Lactis biovar diacetylactis, Lactobacillus plantarum, Leuconostoc meseuteroides subsp. Cremoris and Lactobacillus casei. In this study, we found that a mixture of the six lactic acid bacteria from kefir increased the cytotoxicity of human natural killer KHYG-1 cells to human chronic myelogenous leukemia K562 cells and colorectal tumor HCT116 cells. Furthermore, levels of mRNA expression and secretion of IFN-γ (interferon gamma increased in KHYG-1 cells that had been treated with the six lactic acid bacteria mixture from kefir. The results suggest that the six lactic acid bacteria mixture from kefir has strong effects on natural immunity and tumor cell cytotoxicity.

  5. Mutually stimulating interactions between lactic acid bacteria and Saccharomyces cerevisiae in sourdough fermentation

    Sieuwerts, Sander; Bron, Peter A.; Smid, Eddy J.

    2018-01-01

    Interactions between microorganisms are key to their performance in food habitats. Improved understanding of these interactions supports rational improvement of food fermentations. This study aimed at identifying interactions between lactic acid bacteria and yeast during sourdough fermentation.

  6. Optimization of lactic acid production from glucose using geobacillus stearothermophilus strain 15

    Kunasundari, Balakrishnan; Naresh, Sandrasekaran; Safie, Mohammad Farhan Mohd

    2017-09-01

    This study investigated the conversion efficiency of glucose to lactic acid by Geobacillus stearothermophilus strain 15. Six parameters (temperature, pH, incubation time, agitation speed, carbon and nitrogen concentrations) were screened to identify the most significant factors in affecting lactic acid production using glucose. Three most significant factors (temperature, pH and incubation time) were further optimized in this experiment to determine the optimal production of lactic acid. Numerical optimization gave the point prediction of lactic acid concentration produced at 9.95 g/L with the desirability of 0.979 at 40°C, pH 8.5, 24 h, 100 rpm with 5% glucose and 3% yeast extract.

  7. Kinetics of free radical decay reactions in lactic acid homo and copolymers irradiated to sterilization dose

    Kantoglu, O.; Ozbey, T.; Gueven, O.

    1995-01-01

    The kinetics of free radical decay reactions of poly(L-Lactic acid), poly(DL-Lactic acid) and random copolymer of lactic and glycolic acid have been investigated for decays taking place in air and in vacuum. The change in ESR lines of γ-irradiated polymers have been followed over a long time period. The decay has been found to follow neither simple first-order nor second-order kinetics. Various kinetic approaches including composite first or second-order mechanisms and diffusion-controlled first or second-order equations were determined to be also unsatisfactory. The decay of radicals in bulk irradiated lactic acid homo and copolymers was found to be best described when the second-order non-classical equation with time dependent rate constant approach was used. (Author)

  8. OPTIMIZATION OF VEGETABLE WASTES FOR LACTIC ACID PRODUCTION: A LABORATORY SCALE APPROACH

    Sailaja Daharbha

    2015-04-01

    Full Text Available Vegetables wastes are organic materials which are not utilized as vegetables and are discarded at all stages of production, processing and marketing. These wastes form a major part of municipal solid wastes and are cause of foul smell and growth of microorganisms due to their high organic contents. The vegetable wastes can be utilized in many different ways to produces different products. We have shown that they can be utilized for production of lactic acid using anaerobic digestion. The 2nd day was the optimum day for recovery of lactic acid while 1:1 ratio of slurry and water was found to the best ratio for production of lactic acid from vegetable wastes. Effect of salts on lactic acid was also studied and it was found that the production decreased in all the concentrations of salts.

  9. Lactic acid alleviates stress: good for female genital tract homeostasis, bad for protection against malignancy.

    Witkin, Steven S

    2018-05-01

    Women are unique from all other mammals in that lactic acid is present at high levels in the vagina during their reproductive years. This dominance may have evolved in response to the unique human lifestyle and a need to optimally protect pregnant women and their fetuses from endogenous and exogenous insults. Lactic acid in the female genital tract inactivates potentially pathogenic bacteria and viruses, maximizes survival of vaginal epithelial cells, and inhibits inflammation that may be damaging to the developing fetus and maintenance of the pregnancy. In an analogous manner, lactic acid production facilitates survival of malignantly transformed cells, inhibits activation of immune cells, and prevents the release of pro-inflammatory mediators in response to tumor-specific antigens. Thus, the same stress-reducing properties of lactic acid that promote lower genital tract health facilitate malignant transformation and progression.

  10. Some features of transplutonium and rare earth elements extraction by HDEHP from lactic acid solutions

    Nikolaev, V.M.; Lebedev, V.M.; Lebedeva, L.S.

    1986-01-01

    The mechanisms of transplutonium (TPE) and rare earth elements (REE) extraction by HDEHP from lactic acid solutions are analysed in the literature. On the base of the known expressions and experimental data the model for TPE and REE extraction by HDEHP from lactic acid, accounting lactic acid and metal extraction as MeA 3 x3HA, MeLA 2 x2HA and MeLA 2 complexes, is suggested. The expression, permitting to estimate quantitatively the effect of TPE and REE complexing with lactic acid and the extraction of complex forms on the distribution coefficient of the extracted metal, is obtained. Comparison of calculational data with experimental ones show their good coincidence that confirms the rightness of the model accepted for extraction

  11. Optimisation of lactic acid fermentation for improved vinegar flavour during rosy vinegar brewing.

    Jiang, Yujian; Guo, Jianna; Li, Yudong; Lin, Sen; Wang, Li; Li, Jianrong

    2010-06-01

    Rosy vinegar is a well-known traditional Chinese product whose flavour is affected by its lactic acid content. In this study, Lactobacillus bacteria were employed to increase the content of lactic acid during the ethanol fermentation stage. The optimised fermentation parameters were determined as an inoculation amount of 3% (v/v), a temperature of 30 degrees C and an initial pH value of 4.0. Fermentation under these optimal conditions resulted in an alcohol degree of 6.2% (v/v), a total acidity of 49.5 g L(-1) and a lactic acid content of 4.14 g L(-1). The content of lactic acid (4.14 g L(-1)), which approached the level achieved by solid state fermentation, was 3.56-fold higher than that in vinegar fermented without lactic acid bacteria (1.16 g L(-1)). The results indicate that mixed fermentation with Lactobacillus plantarum and Saccharomyces cerevisiae strains greatly increases the lactic acid content and improves the flavour of rosy vinegar. Copyright (c) 2010 Society of Chemical Industry.

  12. Conversion of Aqueous Ammonia-Treated Corn Stover to Lactic Acid by Simultaneous Saccharification and Cofermentation

    Zhu, Yongming; Lee, Y. Y.; Elander, Richard T.

    Treatment of corn stover with aqueous ammonia removes most of the structural lignin, whereas retaining the majority of the carbohydrates in the solids. After treatment, both the cellulose and hemicellulose in corn stover become highly susceptible to enzymatic digestion. In this study, corn stover treated by aqueous ammonia was investigated as the substrate for lactic acid production by simultaneous saccharification and cofermentation (SSCF). A commercial cellulase (Spezyme-CP) and Lactobacillus pentosus American Type Culture Collection (ATCC) 8041 (Spanish Type Culture Collection [CECT]-4023) were used for hydrolysis and fermentation, respectively. In batch SSCF operation, the carbohydrates in the treated corn stover were converted to lactic acid with high yields, the maximum lactic acid yield reaching 92% of the stoichiometric maximum based on total fermentable carbohydrates (glucose, xylose, and arabinose). A small amount of acetic acid was also produced from pentoses through the phosphoketolase pathway. Among the major process variables for batch SSCF, enzyme loading and the amount of yeast extract were found to be the key factors affecting lactic acid production. Further tests on nutrients indicated that corn steep liquor could be substituted for yeast extract as a nitrogen source to achieve the same lactic acid yield. Fed-batch operation of the SSCF was beneficial in raising the concentration of lactic acid to a maximum value of 75.0 g/L.

  13. High genetic diversity among strains of the unindustrialized lactic acid bacterium Carnobacterium maltaromaticum in dairy products as revealed by multilocus sequence typing.

    Rahman, Abdur; Cailliez-Grimal, Catherine; Bontemps, Cyril; Payot, Sophie; Chaillou, Stéphane; Revol-Junelles, Anne-Marie; Borges, Frédéric

    2014-07-01

    Dairy products are colonized with three main classes of lactic acid bacteria (LAB): opportunistic bacteria, traditional starters, and industrial starters. Most of the population structure studies were previously performed with LAB species belonging to these three classes and give interesting knowledge about the population structure of LAB at the stage where they are already industrialized. However, these studies give little information about the population structure of LAB prior their use as an industrial starter. Carnobacterium maltaromaticum is a LAB colonizing diverse environments, including dairy products. Since this bacterium was discovered relatively recently, it is not yet commercialized as an industrial starter, which makes C. maltaromaticum an interesting model for the study of unindustrialized LAB population structure in dairy products. A multilocus sequence typing scheme based on an analysis of fragments of the genes dapE, ddlA, glpQ, ilvE, pyc, pyrE, and leuS was applied to a collection of 47 strains, including 28 strains isolated from dairy products. The scheme allowed detecting 36 sequence types with a discriminatory index of 0.98. The whole population was clustered in four deeply branched lineages, in which the dairy strains were spread. Moreover, the dairy strains could exhibit a high diversity within these lineages, leading to an overall dairy population with a diversity level as high as that of the nondairy population. These results are in agreement with the hypothesis according to which the industrialization of LAB leads to a diversity reduction in dairy products. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  14. Production of lactic acid from corn cobs through fermentation lactobacillus delbruekii

    Ali, Z.; Anjum, M.; Zahoor, T.

    2007-01-01

    Corn cobs were used as the source of reducing sugars for conversion into lactic acid through fermentation by a local strain of Lactobacillus delbruekii, under varying parameters of time, temperature, pH and glucose concentration, The production of lactic acid significantly increased with increase in Ph, fermentation time and glucose concentration (1-5%) and was significantly high (8.40 g/1) at pH 6, while significantly low (7.67 g/1) at pH 5. (author)

  15. Inhibitory Properties of Lactic Acid Bacteria against Moulds Associated with Spoilage of Bakery Products

    I. A. Adesina; A. O. Ojokoh; D. J. Arotupin

    2017-01-01

    Aim: To evaluate the potentiality of LAB strains isolated from different fermented products to inhibit moulds associated with spoilage of bakery products. Methodology: Lactic acid bacterial (LAB) strains obtained from fermented products (“burukutu”, “pito”, yoghurt, and “iru”) were screened for antifungal activity against moulds (Aspergillus flavus, Aspergillus fumigatus, Aspergillus repens and Penicillium sp.) isolated from spoilt bakery products. Inhibitory activities of the lactic acid...

  16. Cell immobilization for production of lactic acid biofilms do it naturally.

    Dagher, Suzanne F; Ragout, Alicia L; Siñeriz, Faustino; Bruno-Bárcena, José M

    2010-01-01

    Interest in natural cell immobilization or biofilms for lactic acid fermentation has developed considerably over the last few decades. Many studies report the benefits associated with biofilms as industrial methods for food production and for wastewater treatment, since the formation represents a protective means of microbial growth offering survival advantages to cells in toxic environments. The formation of biofilms is a natural process in which microbial cells adsorb to a support without chemicals or polymers that entrap the cells and is dependent on the reactor environment, microorganism, and characteristics of the support. These unique characteristics enable biofilms to cause chronic infections, disease, food spoilage, and devastating effects as in microbial corrosion. Their distinct resistance to toxicity, high biomass potential, and improved stability over cells in suspension make biofilms a good tool for improving the industrial economics of biological lactic acid production. Lactic acid bacteria and specific filamentous fungi are the main sources of biological lactic acid. Over the past two decades, studies have focused on improving the lactic acid volumetric productivity through reactor design development, new support materials, and improvements in microbial production strains. To illustrate the operational designs applied to the natural immobilization of lactic acid producing microorganisms, this chapter presents the results of a search for optimum parameters and how they are affected by the physical, chemical, and biological variables of the process. We will place particular emphasis upon the relationship between lactic acid productivity attained by various types of reactors, supports, media formulations, and lactic acid producing microorganisms. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  17. Continuous D-lactic acid production by a novel thermotolerant Lactobacillus delbrueckii subsp. lactis QU 41.

    Tashiro, Yukihiro; Kaneko, Wataru; Sun, Yanqi; Shibata, Keisuke; Inokuma, Kentaro; Zendo, Takeshi; Sonomoto, Kenji

    2011-03-01

    We isolated and characterized a D-lactic acid-producing lactic acid bacterium (D-LAB), identified as Lactobacillus delbrueckii subsp. lactis QU 41. When compared to Lactobacillus coryniformis subsp. torquens JCM 1166 (T) and L. delbrueckii subsp. lactis JCM 1248 (T), which are also known as D-LAB, the QU 41 strain exhibited a high thermotolerance and produced D-lactic acid at temperatures of 50 °C and higher. In order to optimize the culture conditions of the QU 41 strain, we examined the effects of pH control, temperature, neutralizing reagent, and initial glucose concentration on D-lactic acid production in batch cultures. It was found that the optimal production of 20.1 g/l D-lactic acid was acquired with high optical purity (>99.9% of D-lactic acid) in a pH 6.0-controlled batch culture, by adding ammonium hydroxide as a neutralizing reagent, at 43 °C in MRS medium containing 20 g/l glucose. As a result of product inhibition and low cell density, continuous cultures were investigated using a microfiltration membrane module to recycle flow-through cells in order to improve D-lactic acid productivity. At a dilution rate of 0.87 h(-1), the high cell density continuous culture exhibited the highest D-lactic acid productivity of 18.0 g/l/h with a high yield (ca. 1.0 g/g consumed glucose) and a low residual glucose (<0.1 g/l) in comparison with systems published to date.

  18. Lactic Acid Bacteria from Kefir Increase Cytotoxicity of Natural Killer Cells to Tumor Cells

    Takuya Yamane; Tatsuji Sakamoto; Takenori Nakagaki; Yoshihisa Nakano

    2018-01-01

    The Japanese fermented beverage, homemade kefir, contains six lactic acid bacteria: Lactococcus. lactis subsp. Lactis, Lactococcus. lactis subsp. Cremoris, Lactococcus. Lactis subsp. Lactis biovar diacetylactis, Lactobacillus plantarum, Leuconostoc meseuteroides subsp. Cremoris and Lactobacillus casei. In this study, we found that a mixture of the six lactic acid bacteria from kefir increased the cytotoxicity of human natural killer KHYG-1 cells to human chronic myelogenous leukemia K562 cell...

  19. Diversity and distribution of culturable lactic acid bacterial species in Indonesian Sayur Asin

    Mangunwardoyo, Wibowo; Abinawanto,; Salamah, Andi; Sukara, Endang; Sulistiani,; Dinoto, Achmad

    2016-01-01

    Background and Objectives: Lactic acid bacteria (LAB) play important roles in processing of Sayur Asin (spontaneously fermented mustard). Unfortunately, information about LAB in Indonesian Sayur Asin, prepared by traditional manufactures which is important as baseline data for maintenance of food quality and safety, is unclear. The aim of this study was to describe the diversity and distribution of culturable lactic acid bacteria in Sayur Asin of Indonesia.Materials and Methods: Four Sayur As...

  20. Antioxidant activity of probiotic lactic acid bacteria isolated from Mongolian airag

    E Uugantsetseg; B Batjargal

    2014-01-01

    This research aimed to determine the antioxidant activity of probiotic lactic acid bacteria isolated from airag. In this study, 42 lactic acid bacteria were isolated from Mongolian airag. All isolates were identified by using morphological, biochemical and physiological methods. The isolated bacteria were studied for antagonistic effects on Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus, 22 strains showed antibacterial activity. When we examined thei...

  1. Fabrication and characterization of novel multilayered structures by stereocomplexion of poly(D-lactic acid)/poly(L-lactic acid) and self-assembly of polyelectrolytes

    Elena Dellacasa; Li Zhao; Gesheng Yang; Laura Pastorino; Gleb B. Sukhorukov

    2016-01-01

    The enantiomers poly(D-lactic acid) (PDLA) and poly(L-lactic acid) (PLLA) were alternately adsorbed directly on calcium carbonate (CaCO3) templates and on poly(styrene sulfonate) (PSS) and poly(allylamine hydrochloride) (PAH) multilayer precursors in order to fabricate a novel layer-by-layer (LBL) assembly. A single layer of poly(L-lysine) (PLL) was used as a linker between the (PDLA/PLLA)n stereocomplex and the cores with and without the polymeric (PSS/PAH)n/PLL multilayer precursor (PEM). N...

  2. Non-sterilized fermentation of high optically pure D-lactic acid by a genetically modified thermophilic Bacillus coagulans strain.

    Zhang, Caili; Zhou, Cheng; Assavasirijinda, Nilnate; Yu, Bo; Wang, Limin; Ma, Yanhe

    2017-11-25

    Optically pure D-lactic acid (≥ 99%) is an important precursor of polylactic acid. However, there are relatively few studies on D-lactic acid fermentation compared with the extensive investigation of L-lactic acid production. Most lactic acid producers are mesophilic organisms. Optically pure D-lactic acid produced at high temperature not only could reduce the costs of sterilization but also could inhibit the growth of other bacteria, such as L-lactic acid producers. Thermophilic Bacillus coagulans is an excellent producer of L-lactic acid with capable of growing at 50 °C. In our previous study, the roles of two L-lactic acid dehydrogenases have been demonstrated in B. coagulans DSM1. In this study, the function of another annotated possible L-lactate dehydrogenase gene (ldhL3) was verified to be leucine dehydrogenase with an activity of 0.16 units (μmol/min) per mg protein. Furthermore, the activity of native D-lactate dehydrogenase was too low to support efficient D-lactic acid production, even under the control of strong promoter. Finally, an engineered B. coagulans D-DSM1 strain with the capacity for efficient production of D-lactic acid was constructed by deletion of two L-lactate dehydrogenases genes (ldhL1 and ldhL2) and insertion of the D-lactate dehydrogenase gene (LdldhD) from Lactobacillus delbrueckii subsp. bulgaricus DSM 20081 at the position of ldhL1. This genetically engineered strain produced only D-lactic acid under non-sterilized condition, and finally 145 g/L of D-lactic acid was produced with an optical purity of 99.9% and a high yield of 0.98 g/g. This is the highest optically pure D-lactic acid titer produced by a thermophilic strain.

  3. Development of a new lactic acid bacterial inoculant for fresh rice straw silage

    Jong Geun Kim

    2017-07-01

    Full Text Available Objective Effects of newly isolated Lactobacillus plantarum on the fermentation and chemical composition of fresh rice straw silage was evaluated in this study. Methods Lactic acid bacteria (LAB from good crop silage were screened by growing them in MRS broth and a minimal medium with low carbohydrate content. Selected LAB (LAB 1821 were Gram-positive, rods, catalase negative, and were identified to be Lactobacillus plantarum based on their biochemical characteristics and a 16S rRNA analysis. Fresh rice straw was ensiled with two isolated LAB (1821 and 1841, two commercial inoculants (HM/F and P1132 and no additive as a control. Results After 2 months of storage at ambient temperature, rice straw silages treated with additives were well-preserved, the pH values and butyric and acetic acid contents were lower, and the lactic acid content and lactic/acetic acid ratio were higher than those in the control (p0.05 effect on acid detergent fiber or neutral detergent fiber contents. Crude protein (CP content and in vitro DM digestibility (IVDMD increased after inoculation of LAB 1821 (p<0.05. Conclusion LAB 1821 increased the CP, IVDMD, lactic acid content and ratio of lactic acid to acetic acid in rice straw silage and decreased the pH, acetic acid, NH3-N, and butyric acid contents. Therefore, adding LAB 1821 improved the fermentation quality and feed value of rice straw silage.

  4. Characterization of the spoilage lactic acid bacteria in “sliced vacuum-packed cooked ham”

    Kalschne, Daneysa Lahis; Womer, Rute; Mattana, Ademir; Sarmento, Cleonice Mendes Pereira; Colla, Luciane Maria; Colla, Eliane

    2015-01-01

    The lactic acid bacteria are involved with food fermentation and in such cases with food spoilage. Considering the need to reduce the lactic acid bacteria growth in meat products, the aim of this work was to enumerated and investigated the lactic acid bacteria present on sliced vacuum-packed cooked ham stored at 4 °C and 8 °C for 45 days by phenotypic and molecular techniques. The quantification showed that the lactic acid bacteria were present from the first day with mean count of 1.98 log cfu/g for the four batches analyzed. The lactic acid bacteria grew rapidly on the samples, and plate counts around 7.59 log cfu/g and 8.25 log cfu/g were detected after 45 days of storage at 4 °C and 8 °C, respectively; storage temperatures studied showed significant influence on the microorganism in study growth. The predominant lactic acid bacteria associated with the spoilage samples at one day of storage includes Lactobacillus sp., the phenotypic overlap Leuconostoc / Weissella sp. and Enterococcus sp. At 45 days of storage at 4 and 8 °C the mainly specie was Lactobacillus curvatus , following by Lactobacillus sakei and Leuconostoc mesentereoides ; the Enterococcus sp. was not present in the samples. PMID:26221105

  5. Production of lactic acid from sucrose: strain selection, fermentation, and kinetic modeling.

    Lunelli, Betânia H; Andrade, Rafael R; Atala, Daniel I P; Wolf Maciel, Maria Regina; Maugeri Filho, Francisco; Maciel Filho, Rubens

    2010-05-01

    Lactic acid is an important product arising from the anaerobic fermentation of sugars. It is used in the pharmaceutical, cosmetic, chemical, and food industries as well as for biodegradable polymer and green solvent production. In this work, several bacterial strains were isolated from industrial ethanol fermentation, and the most efficient strain for lactic acid production was selected. The fermentation was conducted in a batch system under anaerobic conditions for 50 h at a temperature of 34 degrees C, a pH value of 5.0, and an initial sucrose concentration of 12 g/L using diluted sugarcane molasses. Throughout the process, pulses of molasses were added in order to avoid the cell growth inhibition due to high sugar concentration as well as increased lactic acid concentrations. At the end of the fermentation, about 90% of sucrose was consumed to produce lactic acid and cells. A kinetic model has been developed to simulate the batch lactic acid fermentation results. The data obtained from the fermentation were used for determining the kinetic parameters of the model. The developed model for lactic acid production, growth cell, and sugar consumption simulates the experimental data well.

  6. Laboratory evaluation of lactic acid on attraction of Culex spp. (Diptera: Culicidae).

    Allan, Sandra A; Bernier, Ulrich R; Kline, Daniel L

    2010-12-01

    The role of lactic acid was evaluated for attraction of Culex nigripalpus, Culex quinquefasciatus, Culex tarsalis, and Aedes aegypti in the laboratory using a dual-port olfactometer. When lactic acid was combined with chicken odor, attraction was increased for Cx. quinquefasciatus compared to chicken odor alone but not for Cx. nigripalpus, Cx. tarsalis, and Ae. aegypti. Lactic acid combined with hand odor did not change attraction of Cx. tarsalis and Ae. aegypti but decreased attraction of Cx. nigripalpus and Cx. quinquefasciatus. The addition of lactic acid to CO(2) increased attraction of Ae. aegypti and Cx. quinquefasciatus but reduced attraction of Cx. nigripalpus and Cx. tarsalis. Use of commercial lactic acid baits with CO(2) resulted in a similar trend except for Cx. nigripalpus which showed no difference. A blend of lactic acid, acetone, and dimethyl disulfide was attractive to Ae. aegypti (63.4%) but elicited low responses by all Culex spp. (1.3-26.8%). Addition of the blend to CO(2) increased attraction of Ae. aegypti and Cx. quinquefasciatus but reduced attraction of Cx. nigripalpus and Cx. tarsalis. The mixture of compounds plus CO(2) was as attractive as a hand for Cx. quinquefasciatus, Cx. tarsalis, and Ae. aegypti. © 2010 The Society for Vector Ecology.

  7. Enhancement of L(+)-Lactic Acid Production of Immobilized Rhizopus Oryzae Implanted by Ion Beams

    Fan Yonghong; Yang Yingge; Zheng Zhiming; Li Wen; Wang Peng; Yao Liming; Yu Zengliang

    2008-01-01

    Immobilized Rhizopus oryzae culturing may be a solution to the inhibited production of L(+)-lactic acid in submerged fermentation, which is caused by aggregated mycelia floc. In the present study, a R. oryzae mutant (RL6041) with a 90% conversion rate of glucose into L-lactic acid was obtained by N + implantation under the optimized conditions of a beam energy of 15 keV and a dose of 2.6 x 10 15 ions/cm 2 . Using polyurethane foam as the immobilization matrix, the optimal L-lactic acid production conditions were determined as 4 mm polyurethane foam, 150 r/min, 50 g/L ∼ 80 g/L of initial glucose, 38 deg. C and pH 6.0. 15-cycle repeated productions of L-lactic acid by immobilized RL6041 were performed under the optimized culturing conditions and over 80% of the glucose was converted into L-lactic acid in 30 hours on average. The results show that immobilized RL6041 is a promising candidate for continuous L-lactic acid production.

  8. CHARACTERIZATION OF LACTIC ACID BACTERIA ISOLATED FROM SUMBAWA MARE MILK

    Nengah Sujaya

    2008-06-01

    Full Text Available A study was carried out to isolate and characterize lactic acid bacteria (LAB from the Sumbawa mares milk The Isolation of LAB was conducted in Man Rogosa Sharpe (MRS agar. The isolates were characterized by standard methods, such as Gram staining, cell morphology study and fermentation activities. The ability of the isolates to inhibit some pathogenic bacteria was studied by dual culture assay. Isolates showing the widest spectrum of inhibiting pathogenic bacteria were further identified using API 50 CHL. The results showed that Sumbawa mare milk was dominated by lactobacilli and weisella/leuconostoc. As many as 26 out 36 isolates belong to homofermentative lactobacilli and another 10 isolates belong to both heterofermentative lactobacilli and weissella or leuconostoc. Twenty four isolates inhibited the growth of Escherichia coli 25922, Shigela flexneri, Salmonella typhimurium, and Staphylococcus aureus 29213. Two promising isolates with the widest spectrum of inhibiting pathogenic bacteria, Lactobacillus sp. SKG34 and Lactobacillus sp. SKG49, were identified respectively as Lactobacillus rhamnosus SKG34 and Lactobacillus ramnosus SKG49. These two isolates were specific strains of the sumbawa mare milk and are very potential to be developed as probiotic for human.

  9. Optimization of β-galactosidase production from lactic acid bacteria

    Carević Milica

    2015-01-01

    Full Text Available β-galactosidase, commonly known as lactase, represents commercially important enzyme that is prevalently used for lactose hydrolysis in milk and whey. To the date, it has been isolated from various sources. In this study different strains of lactic acid bacteria were assessed for their β-galactosidase productivity, and Lactobacillus acidophilus ATCC 4356 resulted with the highest production potential. Thereafter, optimal conditions for accomplishing high yields of β-galactosidase activity were determined. Maximal specific activity (1.01 IU mL-1 was accomplished after 2 days shake flask culture fermentation (150 rpm at 37ºC, with modified Man Rogosa Sharpe culture broth using lactose (2.5% as sole carbon source. Finally, in order to intensify release of intracellular β-galactosidase different mechanical and chemical methods were conducted. Nevertheless, vortexing with quartz sand (150 μm as abrasive was proven to be the most efficient method of cell disruption. The optimum temperature of obtained β-galactosidase was 45°C and the optimum range pH 6.5-7.5.

  10. Poly (lactic acid organoclay nano composites for paper coating applications

    Tatcha Sonjui

    2014-10-01

    Full Text Available Poly(lactic acid or PLA is a well-known biodegradable polymer derived from renewable resources such as corn strach, tapioca strach, and sugar cane. PLA is the most extensively utilized biodegradable polyester with potential to replace conventional petrochemical-based polymers. However, PLA has some drawbacks, such as brittleness and poor gas barrier properties. Nano composite polymers have experience and increasing interest due to their characteristics, especially in mechanical and thermal properties. The objectives of this research were to prepare PLA formulations using three different PLAs. The formulas giving high gloss coating film were selected to prepare nano composite film by incorporated with different amount of various types of organoclays. The physical properties of the PLA coating films were studied and it was found that the PLA 7000D with 0.1%w/w of Cloisite 30B provided decent viscosity for coating process. In addition, the nano composite coating films showed good physical properties such as high gloss, good adhesion, and good hardness. There is a possibility of using the obtained formulation as a paper coating film.

  11. Lactic acid bacteria in dried vegetables and spices.

    Säde, Elina; Lassila, Elisa; Björkroth, Johanna

    2016-02-01

    Spices and dried vegetable seasonings are potential sources of bacterial contamination for foods. However, little is known about lactic acid bacteria (LAB) in spices and dried vegetables, even though certain LAB may cause food spoilage. In this study, we enumerated LAB in 104 spices and dried vegetables products aimed for the food manufacturing industry. The products were obtained from a spice wholesaler operating in Finland, and were sampled during a one-year period. We picked isolates (n = 343) for species identification based on numerical analysis of their ribotyping patterns and comparing them with the corresponding patterns of LAB type strains. We found LAB at levels >2 log CFU/g in 68 (65%) of the samples, with the highest counts detected from dried onion products and garlic powder with counts ranging from 4.24 to 6.64 log CFU/g. The LAB identified were predominantly Weissella spp. (61%) and Pediococcus spp. (15%) with Weissella confusa, Weissella cibaria, Weissella paramesenteroides, Pediococcus acidilactici and Pediococcus pentosaceus being the species identified. Other species identified belonged to the genera of Enterococcus spp. (8%), Leuconostoc spp. (6%) and Lactobacillus spp. (2%). Among the LAB identified, Leuconostoc citreum, Leuconostoc mesenteroides and W. confusa have been associated with food spoilage. Our findings suggest that spices and dried vegetables are potential sources of LAB contamination in the food industry. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Degradation of Poly (lactic acid under Simulated Landfill Conditions

    Chomnutcha Boonmee

    2017-03-01

    Full Text Available In this study, the physical and chemical properties change of poly(lactic acid after burying in the mixture of soil and sludge under thermophilic (61 °C oxygen limited conditions were investigated using various analytical techniques. The environmental factors under these setting conditions and microbial activities accelerated the degradation process of PLA. Under tested conditions, PLA loss their weight about 90% at the burying time of 90 days. During the degradation process, PLA samples were continuously broken to small fragile fragments and showed the size less than 1 mm at the end of degradation test. Change of the surface morphology change was revealed by scanning electron microscopy (SEM. Many pores, cracks and irregular roughness were presented on the PLA surface. Thermal decomposition was decreased from 387.8 to 289.2 °C. The percentage of carbon content in molecular structure decreased from 49.46% to 45.42%. In addition, the Fourier transformed infrared spectroscopy (FTIR revealed the change of ester bonds. This study can be used for developing PLA waste management process.

  13. Adhesion Properties of Lactic Acid Bacteria on Intestinal Mucin

    Keita Nishiyama

    2016-09-01

    Full Text Available Lactic acid bacteria (LAB are Gram-positive bacteria that are natural inhabitants of the gastrointestinal (GI tracts of mammals, including humans. Since Mechnikov first proposed that yogurt could prevent intestinal putrefaction and aging, the beneficial effects of LAB have been widely demonstrated. The region between the duodenum and the terminal of the ileum is the primary region colonized by LAB, particularly the Lactobacillus species, and this region is covered by a mucus layer composed mainly of mucin-type glycoproteins. The mucus layer plays a role in protecting the intestinal epithelial cells against damage, but is also considered to be critical for the adhesion of Lactobacillus in the GI tract. Consequently, the adhesion exhibited by lactobacilli on mucin has attracted attention as one of the critical factors contributing to the persistent beneficial effects of Lactobacillus in a constantly changing intestinal environment. Thus, understanding the interactions between Lactobacillus and mucin is crucial for elucidating the survival strategies of LAB in the GI tract. This review highlights the properties of the interactions between Lactobacillus and mucin, while concomitantly considering the structure of the GI tract from a histochemical perspective.

  14. Separation of viable lactic acid bacteria from fermented milk

    Tomohiko Nishino

    2018-04-01

    Full Text Available Probiotics are live microorganisms that provide health benefits to humans. Some lactic acid bacteria (LAB are probiotic organisms used in the production of fermented foods, such as yogurt, cheese, and pickles. Given their widespread consumption, it is important to understand the physiological state of LAB in foods such as yogurt. However, this analysis is complicated, as it is difficult to separate the LAB from milk components such as solid curds, which prevent cell separation by dilution or centrifugation. In this study, we successfully separated viable LAB from yogurt by density gradient centrifugation. The recovery rate was >90 %, and separation was performed until the stationary phase. Recovered cells were observable by microscopy, meaning that morphological changes and cell viability could be directly detected at the single-cell level. The results indicate that viable LAB can be easily purified from fermented milk. We expect that this method will be a useful tool for the analysis of various aspects of probiotic cells, including their enzyme activity and protein expression. Keywords: Food analysis, Microbiology

  15. Modification of azo dyes by lactic acid bacteria.

    Pérez-Díaz, I M; McFeeters, R F

    2009-08-01

    The ability of Lactobacillus casei and Lactobacillus paracasei to modify the azo dye, tartrazine, was recently documented as the result of the investigation on red coloured spoilage in acidified cucumbers. Fourteen other lactic acid bacteria (LAB) were screened for their capability to modify the food colouring tartrazine and other azo dyes of relevance for the textile industry. Most LAB modified tartrazine under anaerobic conditions, but not under aerobic conditions in modified chemically defined media. Microbial growth was not affected by the presence of the azo dyes in the culture medium. The product of the tartrazine modification by LAB was identified as a molecule 111 daltons larger than its precursor by liquid chromatography-mass spectrometry. This product had a purple colour under aerobic conditions and was colourless under anaerobic conditions. It absorbed light at 361 and 553 nm. LAB are capable of anabolizing azo dyes only under anaerobic conditions. IMPACT AND SIGNIFICANCE OF THE STUDY: Although micro-organisms capable of reducing the azo bond on multiple dyes have been known for decades, this is the first report of anabolism of azo dyes by food related micro-organisms, such as LAB.

  16. Concurrent Lactic and Volatile Fatty Acid Analysis of Microbial Fermentation Samples by Gas Chromatography with Heat Pre-treatment.

    Darwin; WipaCharles; Cord-Ruwisch, Ralf

    2018-01-01

    Organic acid analysis of fermentation samples can be readily achieved by gas chromatography (GC), which detects volatile organic acids. However, lactic acid, a key fermentation acid is non-volatile and can hence not be quantified by regular GC analysis. However the addition of periodic acid to organic acid samples has been shown to enable lactic acid analysis by GC, as periodic acid oxidizes lactic acid to the volatile acetaldehyde. Direct GC injection of lactic acid standards and periodic acid generated inconsistent and irreproducible peaks, possibly due to incomplete lactic acid oxidation to acetaldehyde. The described method is developed to improve lactic acid analysis by GC by using a heat treated derivatization pre-treatment, such that it becomes independent of the retention time and temperature selection of the GC injector. Samples containing lactic acid were amended by periodic acid and heated in a sealed test tube at 100°C for at least 45 min before injecting it to the GC. Reproducible and consistent peaks of acetaldehyde were obtained. Simultaneous determination of lactic acid, acetone, ethanol, butanol, volatile fatty acids could also be accomplished by applying this GC method, enabling precise and convenient organic acid analysis of biological samples such as anaerobic digestion and fermentation processes. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. New potentially antihypertensive peptides liberated in milk during fermentation with selected lactic acid bacteria and kombucha cultures.

    Elkhtab, Ebrahim; El-Alfy, Mohamed; Shenana, Mohamed; Mohamed, Abdelaty; Yousef, Ahmed E

    2017-12-01

    Compounds with the ability to inhibit angiotensin-converting enzyme (ACE) are used medically to treat human hypertension. The presence of such compounds naturally in food is potentially useful for treating the disease state. The goal of this study was to screen lactic acid bacteria, including species commonly used as dairy starter cultures, for the ability to produce new potent ACE-inhibiting peptides during milk fermentation. Strains of Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus delbrueckii ssp. bulgaricus, Lactobacillus helveticus, Lactobacillus paracasei, Lactococcus lactis, Leuconostoc mesenteroides, and Pediococcus acidilactici were tested in this study. Additionally, a symbiotic consortium of yeast and bacteria, used commercially to produce kombucha tea, was tested. Commercially sterile milk was inoculated with lactic acid bacteria strains and kombucha culture and incubated at 37°C for up to 72 h, and the liberation of ACE-inhibiting compounds during fermentation was monitored. Fermented milk was centrifuged and the supernatant (crude extract) was subjected to ultrafiltration using 3- and 10-kDa cut-off filters. Crude and ultrafiltered extracts were tested for ACE-inhibitory activity. The 10-kDa filtrate resulting from L. casei ATCC 7469 and kombucha culture fermentations (72 h) showed the highest ACE-inhibitory activity. Two-step purification of these filtrates was done using HPLC equipped with a reverse-phase column. Analysis of HPLC-purified fractions by liquid chromatography-mass spectrometry/mass spectrometry identified several new peptides with potent ACE-inhibitory activities. Some of these peptides were synthesized, and their ACE-inhibitory activities were confirmed. Use of organisms producing these unique peptides in food fermentations could contribute positively to human health. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  18. Preliminary characterization of wild lactic acid bacteria and their abilities to produce flavour compounds in ripened model cheese system.

    Randazzo, C L; De Luca, S; Todaro, A; Restuccia, C; Lanza, C M; Spagna, G; Caggia, C

    2007-08-01

    The aim of this work was to preliminary characterize wild lactic acid bacteria (LAB), previously isolated during artisanal Pecorino Siciliano (PS) cheese-making for technological and flavour formation abilities in a model cheese system. Twelve LAB were studied for the ability to grow at 10 and 45 degrees C, to coagulate and acidify both reconstituted skim milk and ewe's milk. Moreover, the capacity of the strains to generate aroma compounds was evaluated in a model cheese system at 30- and 60-day ripening. Flavour compounds were screened by sensory analysis and throughout gas chromatography (GC)-mass spectrometry (MS). Most of the strains were able to grow both at 10 and 45 degrees C and exhibited high ability to acidify and coagulate ewes' milk. Sensory evaluation revealed that the wild strains produced more significant flavour attributes than commercial strains in the 60-day-old model cheese system. GC-MS data confirmed the results of sensory evaluations and showed the ability of wild lactobacilli to generate key volatile compounds. Particularly, three wild lactobacilli strains, belonging to Lactobacillus casei, Lb. rhamnosus and Lb. plantarum species, generated both in 60- and 30-day-old model cheeses system, the 3-methyl butan(al)(ol) compound, which is associated with fruity taste. The present work preliminarily demonstrated that the technological and flavour formation abilities of the wild strains are strain-specific and that wild lactobacilli, which produced key flavour compounds during ripening, could be used as tailor-made starters. This study reports the technological characterization and flavour formation ability of wild LAB strains isolated from artisanal Pecorino cheese and highlights that the catabolic activities were highly strain dependent. Hence, wild lactobacilli could be selected as tailor-made starter cultures for the PS cheese manufacture.

  19. THE SEARCH AND PROPERTIES OF LACTIC ACID BACTERIA PERSPECTIVE FOR BIOTECHNOLOGY

    Naumenko О. V.

    2014-10-01

    Full Text Available Search of biologically active Lactobacillus strains prospective for functional milk food production was the aim of the research. The study involved the lactic acid bacteria isolated from biological material of healthy humen and non- dairy lactic products. Using modern methodological approaches, the strains of lactic acid bacteria such as Lactobacillus casei 302, Lactobacillus acidophilus 35 and Streptococcus thermophilus 21 having high level of biological activity were selected. High biological potential of selected cultures of lactic acid bacteria, which could provide stability for the technological process of production and essential characteristics of bacterial preparations and fermented their products, was set. In vitro the experiments demonstrated that selected strains had valuable production properties, namely the ability to reduce level of cholesterol and lactose during development in milk, were resistant to virulent bacteriophages and aggressive compounds of the gastrointestinal tract, and high adhesive and antagonistic activities as well.

  20. Electrospun poly(lactic acid) based conducting nanofibrous networks

    Patra, S N; Bhattacharyya, D; Ray, S; Easteal, A J

    2009-01-01

    Multi-functionalised micro/nanostructures of conducting polymers in neat or blended forms have received much attention because of their unique properties and technological applications in electrical, magnetic and biomedical devices. Biopolymer-based conducting fibrous mats are of special interest for tissue engineering because they not only physically support tissue growth but also are electrically conductive, and thus are able to stimulate specific cell functions or trigger cell responses. They are effective for carrying current in biological environments and can thus be considered for delivering local electrical stimuli at the site of damaged tissue to promote wound healing. Electrospinning is an established way to process polymer solutions or melts into continuous fibres with diameter often in the nanometre range. This process primarily depends on a number of parameters, including the type of polymer, solution viscosity, polarity and surface tension of the solvent, electric field strength and the distance between the spinneret and the collector. The present research has included polyaniline (PANi) as the conducting polymer and poly(L-lactic acid) (PLLA) as the biopolymer. Dodecylbenzene sulphonic acid (DBSA) doped PANi and PLLA have been dissolved in a common solvent (mixtures of chloroform and dimethyl formamide (DMF)), and the solutions successfully electrospun. DMF enhanced the dielectric constant of the solvent, and tetra butyl ammonium bromide (TBAB) was used as an additive to increase the conductivity of the solution. DBSA-doped PANi/PLLA mat exhibits an almost bead-free network of nanofibres that have extraordinarily smooth surface and diameters in the range 75 to 100 nm.

  1. Vaginal pH and microbicidal lactic acid when lactobacilli dominate the microbiota.

    O'Hanlon, Deirdre E; Moench, Thomas R; Cone, Richard A

    2013-01-01

    Lactic acid at sufficiently acidic pH is a potent microbicide, and lactic acid produced by vaginal lactobacilli may help protect against reproductive tract infections. However, previous observations likely underestimated healthy vaginal acidity and total lactate concentration since they failed to exclude women without a lactobacillus-dominated vaginal microbiota, and also did not account for the high carbon dioxide, low oxygen environment of the vagina. Fifty-six women with low (0-3) Nugent scores (indicating a lactobacillus-dominated vaginal microbiota) and no symptoms of reproductive tract disease or infection, provided a total of 64 cervicovaginal fluid samples using a collection method that avoided the need for sample dilution and rigorously minimized aerobic exposure. The pH of samples was measured by microelectrode immediately after collection and under a physiological vaginal concentration of CO2. Commercial enzymatic assays of total lactate and total acetate concentrations were validated for use in CVF, and compared to the more usual HPLC method. The average pH of the CVF samples was 3.5 ± 0.3 (mean ± SD), range 2.8-4.2, and the average total lactate was 1.0% ± 0.2% w/v; this is a five-fold higher average hydrogen ion concentration (lower pH) and a fivefold higher total lactate concentration than in the prior literature. The microbicidal form of lactic acid (protonated lactic acid) was therefore eleven-fold more concentrated, and a markedly more potent microbicide, than indicated by prior research. This suggests that when lactobacilli dominate the vaginal microbiota, women have significantly more lactic acid-mediated protection against infections than currently believed. Our results invite further evaluations of the prophylactic and therapeutic actions of vaginal lactic acid, whether provided in situ by endogenous lactobacilli, by probiotic lactobacilli, or by products that reinforce vaginal lactic acid.

  2. Lactic acid bacteria: promising supplements for enhancing the biological activities of kombucha.

    Nguyen, Nguyen Khoi; Dong, Ngan Thi Ngoc; Nguyen, Huong Thuy; Le, Phu Hong

    2015-01-01

    Kombucha is sweetened black tea that is fermented by a symbiosis of bacteria and yeast embedded within a cellulose membrane. It is considered a health drink in many countries because it is a rich source of vitamins and may have other health benefits. It has previously been reported that adding lactic acid bacteria (Lactobacillus) strains to kombucha can enhance its biological functions, but in that study only lactic acid bacteria isolated from kefir grains were tested. There are many other natural sources of lactic acid bacteria. In this study, we examined the effects of lactic acid bacteria from various fermented Vietnamese food sources (pickled cabbage, kefir and kombucha) on kombucha's three main biological functions: glucuronic acid production, antibacterial activity and antioxidant ability. Glucuronic acid production was determined by high-performance liquid chromatography-mass spectrometry, antibacterial activity was assessed by the agar-well diffusion method and antioxidant ability was evaluated by determining the 2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity. Four strains of food-borne pathogenic bacteria were used in our antibacterial experiments: Listeria monocytogenes ATCC 19111, Escherichia coli ATCC 8739, Salmonella typhimurium ATCC 14028 and Bacillus cereus ATCC 11778. Our findings showed that lactic acid bacteria strains isolated from kefir are superior to those from other sources for improving glucuronic acid production and enhancing the antibacterial and antioxidant activities of kombucha. This study illustrates the potential of Lactobacillus casei and Lactobacillus plantarum isolated from kefir as biosupplements for enhancing the bioactivities of kombucha.

  3. Release of Polyphenols Is the Major Factor Influencing the Bioconversion of Rice Straw to Lactic Acid.

    Chen, Xingxuan; Xue, Yiyun; Hu, Jiajun; Tsang, Yiu Fai; Gao, Min-Tian

    2017-11-01

    In this study, we found that p-coumaric acid (p-CA), ferulic acid (FA), and condensed tannins were released from rice straw during saccharification. The presence of polyphenols prolonged the lag phase and lowered the productivity of lactic acid. p-CA was identified as a key inhibitor. Tannins had a lower inhibitory effect than p-CA; FA had little inhibitory effect. Acid, alkaline, and ball milling pretreatments elicited different levels of polyphenol release from rice straw. Due to the different levels of polyphenol release in the pretreatment step, the enzymatic hydrolysates contained different concentrations of polyphenols. Compared with fermentation with a synthetic medium, fermentation with the hydrolysates of ball-milled rice straw provided much lower productivity and yield of lactic acid due to the presence of polyphenols. Removal of these compounds played an important role in lactic acid fermentation. When rice straw was alkaline pretreated, the hydrolysates contained few phenolic compounds, resulting in high productivity and yield of lactic acid (1.8 g/L/h and 26.7 g/100 g straw), which were comparable to those in a synthetic medium. This indicates that there is a correlation between removal of phenolic compounds and efficiency in lactic acid fermentation.

  4. Lactic acid production by irradiated Bacillus NF17 and poly-L-lactate biopolymer formation

    Tongpim, Saowanit; Poonsawat, Choosak; Khansawai, Paveena; Piadaeng, Nattaya

    2006-09-01

    This study was conducted to manipulate the thermo tolerant, lactic acid-producing bacteria, Bacillus coagulans strain NF 1 7, in the production of L-lactic acid and a bio polymer: poly-L-lactate. The bacterial isolate NF 1 7 kept in the culture collection of Khon Kaen University and could tolerate high temperature and produce lactic acid, was employed in this research work. Cell suspension of isolate NF 1 7 was exposed to gamma irradiation at various doses (1-5 KGy). The irradiated survivors were screened on the basis of forming larger colonies and clear zones than the parent strain NF 1 7 when grown on Glucose-Yeast extract-Peptone (GYP) containing CaCO 3 . We obtained 55 effective isolates which the isolate L5I2-14(5), designated as K 1 4, was chosen together with the parent strain NF 1 7 for fermentation experiments. Each bacterial strain was inoculated into GYP broth and incubated statically at 50 o C with daily pH neutralization. After 5 days of incubation, the isolate K 1 4 and NF 1 7 produced 9.71 g/l and 7.42 g/l of L-lactic acid, respectively with a small amount of D-lactic acid. Lactic acid production from sugar cane molasses by batch fermentation of Bacillus Sp. K 1 4 was carried out in a 7 l jar fermentor containing 5 l of fermentation medium. It was found that 20% molasses with the agitation speed of 100 rpm gave the highest yield of lactic acid. Poly-L-lactic acid was chemically polymerized by bulk polymerization process at 140 o C under 40 mmHg conditions. We could obtain the off-white polymer in a small amount of powder form. Improvement the yield of poly-L-lactic acid would be achieved by using polyisoprene-g-polyvinyl monomer to separate lactic acid from the fermenting liquid prior to polymerization processes

  5. Impact of lactic acid bacteria on conjugated linoleic acid content and atherogenic index of butter

    L Roufegari-Nejad

    2012-11-01

    Full Text Available This is a study aimed to investigate the effect of lactic acid bacteria including Lactobacillus acidophilus and Sterptococcus thermophilus (as thermophilic culture, Lactococcus lactis subsp. lactis, cremoris and diacetylactis, Leuconostoc citrovorum (as mesophilic culture, Lactobacillus acidophilus, Lactobacillus casei, Bifidobacterium lactis and a mixed culture of L.acidophilus, L. casei and B. lactis on fatty acid profile, conjugated linoleic acid (CLA and atherogenic index (AI of butter. Fatty acid analysis with gas chromatography indicated that application of thermophilic and mixed culture decreased the ratio of saturated to unsaturated fatty acid; whereas, the butters made with L. acidophilus had the highest content of CLA. Moreover, AI in the samples prepared with thermophilic cultures was the least. Sensory evaluation of the treatments revealed no significant differences (p> 0/05 in appearance and color. However, the butters prepared with thermophilic and mesophilic cultures had more desirable taste in comparison with the samples made with L. acidophilus, L. casei and B. lactis. From the nutritional point of view, the adverse effect of butter could be diminished via the application of selected lactic acid bacteria.

  6. Molecular identification and technological characterization of lactic acid bacteria isolated from fermented kidney beans flours (Phaseolus vulgaris L. and P. coccineus) in northwestern Argentina.

    Sáez, Gabriel D; Hébert, Elvira M; Saavedra, Lucila; Zárate, Gabriela

    2017-12-01

    Legumes are an important protein source in developing countries and their flours represent an attractive alternative for the manufacture of gluten free products. In the present study, 4 kidney bean varieties (Alubia, Pallar, Black and Red beans) commonly cultivated in northwestern Argentina, were milled and spontaneously fermented in order to isolate and select autochthonous lactic acid bacteria (LAB) with relevant technological and functional properties for usage as starter cultures. Twelve doughs were fermented with daily back-slopping at 37°C for 6days and evolution of total mesophiles, lactic acid bacteria, and yeasts and molds populations were followed by plate counting. A combination of phenotypic and genotypic methods including (GTG) 5 -based PCR fingerprinting and 16S rRNA gene sequencing were used to differentiate and identify the isolated LAB to species level. LAB counts ranged from around 0.89±0.81 to 8.74±0.03logcfu/g with a pH decline from 6.4 to 3.9 throughout fermentation. Four genera and nine species of LAB: Enterococcus durans, E. faecium, E. mundtii, E. casseliflavus; Lactobacillus rhamnosus, Lactococcus garvieae, Weissella cibaria and W. paramesenteroides were found on kidney beans. Twenty five LAB strains were assessed for their abilities to grow on kidney bean extracts, acidifying capacities (pH and acidification rates), amylolytic, proteolytic, tannase and gallate decarboxylase activities as well as pathogens inhibition by antimicrobials. Based on these properties E. durans CRL 2178 and W. paramesenteroides CRL 2182 were inoculated singly and combined in Alubia kidney bean flour and fermented for 24h at 37°C. LAB strains were beneficial for removing trypsin inhibitors and tannins from sourdoughs and for improving amino acids and phenolics contents, increasing the antioxidant activities of kidney bean matrices. Selected strains have potential as starter cultures for obtaining fermented bean products with high nutritional and functional

  7. From honeycomb- to microsphere-patterned surfaces of poly(lactic acid) and a starch-poly(lactic acid) blend via the breath figure method.

    Duarte, Ana Rita C; Maniglio, Devid; Sousa, Nuno; Mano, João F; Reis, Rui L; Migliaresi, Claudio

    2017-01-26

    This study investigated the preparation of ordered patterned surfaces and/or microspheres from a natural-based polymer, using the breath figure and reverse breath figure methods. Poly(D,L-lactic acid) and starch poly(lactic acid) solutions were precipitated in different conditions - namely, polymer concentration, vapor atmosphere temperature and substrate - to evaluate the effect of these conditions on the morphology of the precipitates obtained. The possibility of fine-tuning the properties of the final patterns simply by changing the vapor atmosphere was also demonstrated here using a range of compositions of the vapor phase. Porous films or discrete particles are formed when the differences in surface tension determine the ability of polymer solution to surround water droplets or methanol to surround polymer droplets, respectively. In vitro cytotoxicity was assessed applying a simple standard protocol to evaluate the possibility to use these materials in biomedical applications. Moreover, fluorescent microscopy images showed a good interaction of cells with the material, which were able to adhere on the patterned surfaces after 24 hours in culture. The development of patterned surfaces using the breath figure method was tested in this work for the preparation of both poly(lactic acid) and a blend containing starch and poly(lactic acid). The potential of these films to be used in the biomedical area was confirmed by a preliminary cytotoxicity test and by morphological observation of cell adhesion.

  8. Acid and bile tolerance of spore-forming lactic acid bacteria.

    Hyronimus, B; Le Marrec, C; Sassi, A H; Deschamps, A

    2000-11-01

    Criteria for screening probiotics such as bile tolerance and resistance to acids were studied with 13 spore-forming lactic acid producing bacteria. Different strains of Sporolactobacillus, Bacillus laevolacticus, Bacillus racemilacticus and Bacillus coagulans grown in MRS broth were subjected to low pH conditions (2, 2.5 and 3) and increasing bile concentrations. Among these microorganisms, Bacillus laevolacticus DSM 6475 and all Sporolactobacillus strains tested except Sporolactobacillus racemicus IAM 12395, were resistant to pH 3. Only Bacillus racemilacticus and Bacillus coagulans strains were tolerant to bile concentrations over 0.3% (w/v).

  9. Characteristics of immobilized lactobacillus delbrueckii in a liquid-solid fluidized bed bioreactor for lactic acid production

    Wang, Henian; Seki, M.; Furusaki, S. [The Univ. of Tokyo (Japan). Faculty of Engineering

    1995-04-20

    A fluidized bed bioreactor was employed for lactic acid production using immobilized cells. First, the cell release rate was discussed. A liquid-solid fluidized bed reactor with immobilized cells was used to perform continuous lactic acid fermentation without any operational problems. The performance of the reactor was investigated under different conditions. Cell release rate and contribution of free cells to lactic acid production were studied quantitatively. The results showed that under low gel holdup and low dilution rate conditions, free cells played a significant role in lactic acid production. However, increasing solid holdup decreased the free cell concentration in the broth due to high lactic acid concentration and also decreased the contribution of the free cells to lactic acid production. The effects of growth nutrients on reactor performance were investigated. 16 refs., 12 figs.

  10. Poly(ethylene glycol) (PEG)-lactic acid nanocarrier-based degradable hydrogels for restoring the vaginal microenvironment

    Rajan, Sujata Sundara; Turovskiy, Yevgeniy; Singh, Yashveer; Chikindas, Michael L.; Sinko, Patrick J.

    2014-01-01

    Women with bacterial vaginosis (BV) display reduced vaginal acidity, which make them susceptible to associated infections such as HIV. In the current study, poly(ethylene glycol) (PEG) nanocarrier-based degradable hydrogels were developed for the controlled release of lactic acid in the vagina of BV-infected women. PEG-lactic acid (PEG-LA) nanocarriers were prepared by covalently attaching lactic acid to 8-arm PEG-SH via cleavable thioester bonds. PEG-LA nanocarriers with 4 copies of lactic acid per molecule provided controlled release of lactic acid with a maximum release of 23% and 47% bound lactic acid in phosphate buffered saline (PBS, pH 7.4) and acetate buffer (AB, pH 4.3), respectively. The PEG nanocarrier-based hydrogels were formed by cross-linking the PEG-LA nanocarriers with 4-arm PEG-NHS via degradable thioester bonds. The nanocarrier-based hydrogels formed within 20 min under ambient conditions and exhibited an elastic modulus that was 100-fold higher than the viscous modulus. The nanocarrier-based degradable hydrogels provided controlled release of lactic acid for several hours; however, a maximum release of only 10%–14% bound lactic acid was observed possibly due to steric hindrance of the polymer chains in the cross-linked hydrogel. In contrast, hydrogels with passively entrapped lactic acid showed burst release with complete release within 30 min. Lactic acid showed antimicrobial activity against the primary BV pathogen Gardnerella vaginalis with a minimum inhibitory concentration (MIC) of 3.6 mg/ml. In addition, the hydrogels with passively entrapped lactic acid showed retained antimicrobial activity with complete inhibition G. vaginalis growth within 48 h. The results of the current study collectively demonstrate the potential of PEG nanocarrier-based hydrogels for vaginal administration of lactic acid for preventing and treating BV. PMID:25223229

  11. Short communication: Change of naturally occurring benzoic acid during skim milk fermentation by commercial cheese starters.

    Han, Noori; Park, Sun-Young; Kim, Sun-Young; Yoo, Mi-Young; Paik, Hyun-Dong; Lim, Sang-Dong

    2016-11-01

    This study sought to investigate the change of naturally occurring benzoic acid (BA) during skim milk fermentation by 4 kinds of commercial cheese starters used in domestic cheese. The culture was incubated at 3-h intervals for 24h at 30, 35, and 40°C. The BA content during fermentation by Streptococcus thermophilus STB-01 was detected after 12h at all temperatures, sharply increasing at 30°C. In Lactobacillus paracasei LC431, BA was detected after 9h at all temperatures, sharply increasing until 18h and decreasing after 18h at 30 and 35°C. In the case of R707 (consisting of Lactococcus lactis ssp. lactis and Lactococcus lactis ssp. cremoris), BA increased from 6h to 15h and decreased after 15h at 40°C. The BA during STB-01 and CHN-11 (1:1; mixture of S. thermophilus, Lc. lactis ssp. lactis, Lc. lactis ssp. cremoris, Lc. lactis ssp. diacetylactis, Leuconostoc mesenteroides ssp. cremoris) fermentation was detected after 3h at 35 and 40°C, sharply increasing up to 12h and decreasing after 15h at 35°C, and after 6h, increasing up to 9h at 30°C. After 3h, it steadily decreased at 40°C. The highest amount of BA was found during the fermentation by R707 at 30°C; 15h with 12.46mg/kg. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  12. Systems biology of lactic acid bacteria: a critical review.

    Teusink, Bas; Bachmann, Herwig; Molenaar, Douwe

    2011-08-30

    Understanding the properties of a system as emerging from the interaction of well described parts is the most important goal of Systems Biology. Although in the practice of Lactic Acid Bacteria (LAB) physiology we most often think of the parts as the proteins and metabolites, a wider interpretation of what a part is can be useful. For example, different strains or species can be the parts of a community, or we could study only the chemical reactions as the parts of metabolism (and forgetting about the enzymes that catalyze them), as is done in flux balance analysis. As long as we have some understanding of the properties of these parts, we can investigate whether their interaction leads to novel or unanticipated behaviour of the system that they constitute. There has been a tendency in the Systems Biology community to think that the collection and integration of data should continue ad infinitum, or that we will otherwise not be able to understand the systems that we study in their details. However, it may sometimes be useful to take a step back and consider whether the knowledge that we already have may not explain the system behaviour that we find so intriguing. Reasoning about systems can be difficult, and may require the application of mathematical techniques. The reward is sometimes the realization of unexpected conclusions, or in the worst case, that we still do not know enough details of the parts, or of the interactions between them. We will discuss a number of cases, with a focus on LAB-related work, where a typical systems approach has brought new knowledge or perspective, often counterintuitive, and clashing with conclusions from simpler approaches. Also novel types of testable hypotheses may be generated by the systems approach, which we will illustrate. Finally we will give an outlook on the fields of research where the systems approach may point the way for the near future.

  13. Interactions between Cooccurring Lactic Acid Bacteria in Honey Bee Hives.

    Rokop, Z P; Horton, M A; Newton, I L G

    2015-10-01

    In contrast to the honey bee gut, which is colonized by a few characteristic bacterial clades, the hive of the honey bee is home to a diverse array of microbes, including many lactic acid bacteria (LAB). In this study, we used culture, combined with sequencing, to sample the LAB communities found across hive environments. Specifically, we sought to use network analysis to identify microbial hubs sharing nearly identical operational taxonomic units, evidence which may indicate cooccurrence of bacteria between environments. In the process, we identified interactions between noncore bacterial members (Fructobacillus and Lactobacillaceae) and honey bee-specific "core" members. Both Fructobacillus and Lactobacillaceae colonize brood cells, bee bread, and nectar and may serve the role of pioneering species, establishing an environment conducive to the inoculation by honey bee core bacteria. Coculture assays showed that these noncore bacterial members promote the growth of honey bee-specific bacterial species. Specifically, Fructobacillus by-products in spent medium supported the growth of the Firm-5 honey bee-specific clade in vitro. Metabolic characterization of Fructobacillus using carbohydrate utilization assays revealed that this strain is capable of utilizing the simple sugars fructose and glucose, as well as the complex plant carbohydrate lignin. We tested Fructobacillus for antibiotic sensitivity and found that this bacterium, which may be important for establishment of the microbiome, is sensitive to the commonly used antibiotic tetracycline. Our results point to the possible significance of "noncore" and environmental microbial community members in the modulation of honey bee microbiome dynamics and suggest that tetracycline use by beekeepers should be limited. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  14. [Cloning and gene expression in lactic acid bacteria].

    Bondarenko, V M; Beliavskaia, V A

    2000-01-01

    The possibility of using the genera Lactobacillus and Lactococcus as vector representatives is widely discussed at present. The prospects of the construction of recombinant bacteria are closely connected with the solution of a number of problems: the level of the transcription of cloned genes, the effectiveness of the translation of heterologous mRNA, the stability of protein with respect to bacterial intracellular proteases, the method by protein molecules leave the cell (by secretion or as the result of lysis). To prevent segregation instability, the construction of vector molecules on the basis of stable cryptic plasmids found in wild strains of lactic acid bacteria was proposed. High copying plasmids with low molecular weight were detected in L. plantarum and L. pentosus strains. Several plasmids with molecular weights of 1.7, 1.8 and 2.3 kb were isolated from bacterial cells to be used as the basis for the construction of vector molecules. Genes of chloramphenicol- and erythromycin-resistance from Staphylococcus aureus plasmids were used as marker genes ensuring cell transformation. The vector plasmids thus constructed exhibited high transformation activity in the electroporation of different strains, including L. casei, L. plantarum, L. acidophilus, L. fermentum and L. brevis which could be classified with the replicons of a wide circle of hosts. But the use of these plasmids was limited due to the risk of the uncontrolled dissemination of recombinant plasmids. L. acidophilus were also found to have strictly specific plasmids with good prospects of being used as the basis for the creation of vectors, incapable of dissemination. In addition to the search of strain-specific plasmids, incapable of uncontrolled gene transmission, the use of chromosome-integrated heterologous genes is recommended in cloning to ensure the maximum safety.

  15. Selection of Lactic Acid Bacteria as Probiotic Candidate for Chicken

    F. Hamida

    2015-08-01

    Full Text Available Lactic acid bacteria (LAB regarded as safe microorganisms; they can naturally live in gastrointestinal tract, so appropriately used as a probiotic for chicken. This study aimed to select six isolates of LAB (E1223, E3, E4, E5, E7, and E8 to obtain the isolates potentially as probiotic candidate for chicken. The six isolates were derived from spontaneous fermented corn obtained from Laboratory of Animal Biotechnology and Biomedical, PPSHB, Bogor Agricultural University, Indonesia. LAB isolates were tested their susceptibility to antibiotics (bambermycin, erythromycin, chloramphenicol, and tetracycline then were examined in vitro for their tolerance to gastrointestinal pH (2, 3, 4, and 7.2 and 0.5% bile salt condition, antimicrobial activity against Salmonella enteritidis and Enterococcus casseliflavus, and ability to adhere to chicken ileal cells. The results showed the isolates E5, E7, and E8 were sensitive to tetracycline and chloramphenicol, they could survive at pH 2, 3, 4, and 7.2, could survive at 0.5% bile salts, produced antimicrobial activity, and able to adhere to ileal cells (9.40±0.00 Log CFU/cm2 of E8 and were significantly (P<0.05 higher than those of control (5.30±0.14 Log CFU/cm2. In conclusion, this study showed that isolate E8 had better potential compared to isolates E5 and E7 in most in vitro assays as a probiotic candidate for chicken. E5, E7, and E8 were closely related with Pediococcus pentosaceus based on 16S rRNA gene.

  16. Isolation of Lactic Acid Bacteria That Produce Protease and Bacteriocin-Like Substance From Mud Crab (Scylla sp. Digestive Tract (Isolasi Bakteri Asam Laktat yang Menghasilkan Protease dan Senyawa Bacteriocin-Like dari Saluran Pencernaan Kepiting

    Heru Pramono

    2015-03-01

    Kata kunci: Bakteri Asam Laktat, Bakteriosin-like substance, Protease, Scylla  sp. Digestive tract is complex environment consist of large amount of bacteria’s species. Fish intestine bacteria consist of aerobic or facultative anaerob bacteria which can produce antibacterial and enzym. The objectives of this research were to isolated lactic acid bacteria that produce bacteriocin-like and protease from mud crab digestive tract. Isolation and characterization of isolates were conducted employing media MRS.  Neutralized cell free supernatant of isolates were tested using disc diffusion agar of against pathogenic and spoilage bacteria to indicate bacteriocin-like-producing lactic acid bacteria. Protease-producing isolate was tested using disc diffusion method in casein agar. Among a hundred isolates, 96 isolates were showed clear zone in MRS+CaCO3,, catalase negative, and Gram positive bacteria. Thirty four isolates produced protease and only four isolates (i.e. IKP29, IKP30, IKP52, and IKP94 showed strong inhibition against pathogenic and spoilage bacteria. There were three patterns of inhibition among three isolates against Bacillus subtilis, Staphylococcus aureus, Eschericia coli, and Salmonella sp. All three isolates showed potential uses for produce starter culture for fishery product fermentation purpose. This is the first report of isolation lactic acid bacteria that produced protease and bacteriocin-like from digestive tract of mud crab. Keywords: Lactic acid bacteria, Bacteriocin-like substance, Protease, Scylla  sp.

  17. L: (+)-Lactic acid production from non-food carbohydrates by thermotolerant Bacillus coagulans.

    Ou, Mark S; Ingram, Lonnie O; Shanmugam, K T

    2011-05-01

    Lactic acid is used as an additive in foods, pharmaceuticals, and cosmetics, and is also an industrial chemical. Optically pure lactic acid is increasingly used as a renewable bio-based product to replace petroleum-based plastics. However, current production of lactic acid depends on carbohydrate feedstocks that have alternate uses as foods. The use of non-food feedstocks by current commercial biocatalysts is limited by inefficient pathways for pentose utilization. B. coagulans strain 36D1 is a thermotolerant bacterium that can grow and efficiently ferment pentoses using the pentose-phosphate pathway and all other sugar constituents of lignocellulosic biomass at 50°C and pH 5.0, conditions that also favor simultaneous enzymatic saccharification and fermentation (SSF) of cellulose. Using this bacterial biocatalyst, high levels (150-180 g l(-1)) of lactic acid were produced from xylose and glucose with minimal by-products in mineral salts medium. In a fed-batch SSF of crystalline cellulose with fungal enzymes and B. coagulans, lactic acid titer was 80 g l(-1) and the yield was close to 80%. These results demonstrate that B. coagulans can effectively ferment non-food carbohydrates from lignocellulose to L: (+)-lactic acid at sufficient concentrations for commercial application. The high temperature fermentation of pentoses and hexoses to lactic acid by B. coagulans has these additional advantages: reduction in cellulase loading in SSF of cellulose with a decrease in enzyme cost in the process and a reduction in contamination of large-scale fermentations.

  18. Strategies for improving production performance of probiotic Pediococcus acidilactici viable cell by overcoming lactic acid inhibition.

    Othman, Majdiah; Ariff, Arbakariya B; Wasoh, Helmi; Kapri, Mohd Rizal; Halim, Murni

    2017-11-27

    Lactic acid bacteria are industrially important microorganisms recognized for fermentative ability mostly in their probiotic benefits as well as lactic acid production for various applications. Fermentation conditions such as concentration of initial glucose in the culture, concentration of lactic acid accumulated in the culture, types of pH control strategy, types of aeration mode and different agitation speed had influenced the cultivation performance of batch fermentation of Pediococcus acidilactici. The maximum viable cell concentration obtained in constant fed-batch fermentation at a feeding rate of 0.015 L/h was 6.1 times higher with 1.6 times reduction in lactic acid accumulation compared to batch fermentation. Anion exchange resin, IRA 67 was found to have the highest selectivity towards lactic acid compared to other components studied. Fed-batch fermentation of P. acidilactici coupled with lactic acid removal system using IRA 67 resin showed 55.5 and 9.1 times of improvement in maximum viable cell concentration compared to fermentation without resin for batch and fed-batch mode respectively. The improvement of the P. acidilactici growth in the constant fed-batch fermentation indicated the use of minimal and simple process control equipment is an effective approach for reducing by-product inhibition. Further improvement in the cultivation performance of P. acidilactici in fed-bath fermentation with in situ addition of anion-exchange resin significantly helped to enhance the growth of P. acidilactici by reducing the inhibitory effect of lactic acid and thus increasing probiotic production.

  19. Lactic acid fermentation of human urine to improve its fertilizing value and reduce odour emissions.

    Andreev, N; Ronteltap, M; Boincean, B; Wernli, M; Zubcov, E; Bagrin, N; Borodin, N; Lens, P N L

    2017-08-01

    During storage of urine, urea is biologically decomposed to ammonia, which can be lost through volatilization and in turn causes significant unpleasant smell. In response, lactic acid fermentation of urine is a cost-effective technique to decrease nitrogen volatilization and reduce odour emissions. Fresh urine (pH = 5.2-5.3 and NH 4 + -N = 1.2-1.3 g L -1 ) was lacto-fermented for 36 days in closed glass jars with a lactic acid bacterial inoculum from sauerkraut juice and compared to untreated, stored urine. In the lacto-fermented urine, the pH was reduced to 3.8-4.7 and the ammonium content by 22-30%, while the pH of the untreated urine rose to 6.1 and its ammonium content increased by 32% due to urea hydrolysis. The concentration of lactic acid bacteria in lacto-fermented urine was 7.3 CFU ml -1 , suggesting that urine is a suitable growth medium for lactic acid bacteria. The odour of the stored urine was subjectively perceived by four people to be twice as strong as that of lacto-fermented samples. Lacto-fermented urine induced increased radish germination compared to stored urine (74-86% versus 2-31%). Adding a lactic acid bacterial inoculum to one week old urine in the storage tanks in a urine-diverting dry toilet reduced the pH from 8.9 to 7.7 after one month, while the ammonium content increased by 35%, probably due to the high initial pH of the urine. Given that the hydrolyzed stale urine has a high buffering capacity, the lactic acid bacterial inoculum should be added to the urine storage tank of a UDDT before urine starts to accumulate there to increase the efficiency of the lactic acid fermentation. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    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.

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

    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 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.

  2. Phenotypic and genotypic characterization of lactic acid bacteria isolated from raw goat milk and effect of farming practices on the dominant species of lactic acid bacteria.

    Tormo, Hélène; Ali Haimoud Lekhal, Djamila; Roques, C

    2015-10-01

    Lactic acid bacteria, in particular Lactococcus lactis, play a decisive role in the cheese making process and more particularly in lactic cheeses which are primarily produced on goat dairy farms. The objective of this study was therefore to identify the main lactic acid bacteria found in raw goats' milk from three different regions in France and evaluate if certain farming practices have an effect on the distribution of species of lactic acid bacteria in the various milk samples. Identification at genus or species level was carried out using phenotypic tests and genotypic methods including repetitive element REP-PCR, species-specific PCR and 16S rRNA gene sequencing. The distribution of the main bacterial species in the milk samples varied depending on farms and their characteristics. Out of the 146 strains identified, L. lactis was the dominant species (60% of strains), followed by Enterococcus (38%) of which Enterococcus faecalis and Enterococcus faecium. Within the species L. lactis, L. lactis subsp lactis was detected more frequently than L. lactis subsp cremoris (74% vs. 26%). The predominance of L. lactis subsp cremoris was linked to geographical area studied. It appears that the animals' environment plays a role in the balance between the dominance of L. lactis and enterococci in raw goats' milk. The separation between the milking parlor and the goat shed (vs no separation) and only straw in the bedding (vs straw and hay) seems to promote L. lactis in the milk (vs enterococci). Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Simultaneous Saccharification and Fermentation of Sugar Beet Pulp with Mixed Bacterial Cultures for Lactic Acid and Propylene Glycol Production

    Joanna Berlowska

    2016-10-01

    Full Text Available Research into fermentative production of lactic acid from agricultural by-products has recently concentrated on the direct conversion of biomass, whereby pure sugars are replaced with inexpensive feedstock in the process of lactic acid production. In our studies, for the first time, the source of carbon used is sugar beet pulp, generated as a by-product of industrial sugar production. In this paper, we focus on the simultaneous saccharification of lignocellulosic biomass and fermentation of lactic acid, using mixed cultures with complementary assimilation profiles. Lactic acid is one of the primary platform chemicals, and can be used to synthesize a wide variety of useful products, including green propylene glycol. A series of controlled batch fermentations was conducted under various conditions, including pretreatment with enzymatic hydrolysis. Inoculation was performed in two sequential stages, to avoid carbon catabolite repression. Biologically-synthesized lactic acid was catalytically reduced to propylene glycol over 5% Ru/C. The highest lactic acid yield was obtained with mixed cultures. The yield of propylene glycol from the biological lactic acid was similar to that obtained with a water solution of pure lactic acid. Our results show that simultaneous saccharification and fermentation enables generation of lactic acid, suitable for further chemical transformations, from agricultural residues.

  4. New trends and challenges in lactic acid production on renewable biomass

    Đukić-Vuković Aleksandra J.

    2011-01-01

    Full Text Available Lactic acid is a relatively cheap chemical with a wide range of applications: as a preservative and acidifying agent in food and dairy industry, a monomer for biodegradable poly-lactide polymers (PLA in pharmaceutical industry, precursor and chemical feedstock for chemical, textile and leather industries. Traditional raw materials for fermentative production of lactic acid, refined sugars, are now being replaced with starch from corn, rice and other crops for industrial production, with a tendency for utilization of agro industrial wastes. Processes based on renewable waste sources have ecological (zero CO2 emission, eco-friendly by-products and economical (cheap raw materials, reduction of storage costs advantages. An intensive research interest has been recently devoted to develop and improve the lactic acid production on more complex industrial by-products, like thin stillage from bioethanol production, corncobs, paper waste, straw etc. Complex and variable chemical composition and purity of these raw materials and high nutritional requirements of Lare the main obstacles in these production processes. Media supplementation to improve the fermentation is an important factor, especially from an economic point of view. Today, a particular challenge is to increase the productivity of lactic acid production on complex renewable biomass. Several strategies are currently being explored for this purpose such as process integration, use of Lwith amylolytic activity, employment of mixed cultures of Land/or utilization of genetically engineered microorganisms. Modern techniques of genetic engineering enable construction of microorganisms with desired characteristics and implementation of single step processes without or with minimal pre-treatment. In addition, new bioreactor constructions (such as membrane bioreactors, utilization of immobilized systems are also being explored. Electrodialysis, bipolar membrane separation process, enhanced filtration

  5. D-lactic acid interferes with the effects of platelet activating factor on bovine neutrophils.

    Alarcón, P; Conejeros, I; Carretta, M D; Concha, C; Jara, E; Tadich, N; Hidalgo, M A; Burgos, R A

    2011-11-15

    D-lactic acidosis occurs in ruminants, such as cattle, with acute ruminal acidosis caused by ingestion of excessive amounts of highly fermentable carbohydrates. Affected animals show clinical signs similar to those of septic shock, as well as acute laminitis and liver abscesses. It has been proposed that the inflammatory response and susceptibility to infection could both be caused by the inhibition of phagocytic mechanisms. To determine the effects of d-lactic acid on bovine neutrophil functions, we pretreated cells with different concentrations of D-lactic acid and measured intracellular pH using 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein acetoxymethyl ester (BCECF-AM) and calcium flux using FLUO-3 AM-loaded neutrophils. Reactive oxygen species (ROS) production was measured using a luminol chemiluminescence assay, and MMP-9/gelatinase-B granule release was measured by zymography. CD11b and CD62L/l-selectin expression, changes in cell shape, superoxide anion production, phagocytosis of Escherichia coli-Texas red bioparticles, and apoptosis were all measured using flow cytometry. Our results demonstrated that D-lactic acid reduced ROS production, CD11b upregulation and MMP-9 release in bovine neutrophils treated with 100 nM platelet-activating factor (PAF). D-lactic acid induced MMP-9 release and, at higher concentrations, upregulated CD11b expression, decrease L-selectin expression, and induces late apoptosis. We concluded that D-lactic acid can interfere with neutrophil functions induced by PAF, leading to reduced innate immune responses during bacterial infections. Moreover, the increase of MMP-9 release and CD11b expression induced by 10mM D-lactic acid could promote an nonspecific neutrophil-dependent inflammatory reaction in cattle with acute ruminal acidosis. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Hypolipidemic effects of lactic acid bacteria fermented cereal in rats

    Banjoko Immaculata

    2012-12-01

    Full Text Available Abstract Background The objectives of the present study were to investigate the efficacy of the mixed culture of Lactobacillus acidophilus (DSM 20242, Bifidobacterium bifidum (DSM 20082 and Lactobacillus helveticus (CK60 in the fermentation of maize and the evaluation of the effect of the fermented meal on the lipid profile of rats. Methods Rats were randomly assigned to 3 groups and each group placed on a Diet A (high fat diet into which a maize meal fermented with a mixed culture of Lb acidophilus (DSM 20242, B bifidum (DSM 20082 and Lb helveticus (CK 60 was incorporated, B (unfermented high fat diet or C (commercial rat chow respectively after the first group of 7 rats randomly selected were sacrificed to obtain the baseline data. Thereafter 7 rats each from the experimental and control groups were sacrificed weekly for 4 weeks and the plasma, erythrocytes, lipoproteins and organs of the rats were assessed for cholesterol, triglyceride and phospholipids. Results Our results revealed that the mixed culture of Lb acidophilus (DSM 20242, B bifidum (DSM 20082 and Lb helveticus (CK 60 were able to grow and ferment maize meal into ‘ogi’ of acceptable flavour. In addition to plasma and hepatic hypercholesterolemia and hypertriglyceridemia, phospholipidosis in plasma, as well as cholesterogenesis, triglyceride constipation and phospholipidosis in extra-hepatic tissues characterized the consumption of unfermented hyperlipidemic diets. However, feeding the animals with the fermented maize diet reversed the dyslipidemia. Conclusion The findings of this study indicate that consumption of mixed culture lactic acid bacteria (Lb acidophilus (DSM 20242, Bifidobacterium bifidum (DSM 20082 and Lb helveticus (CK 60 fermented food results in the inhibition of fat absorption. It also inhibits the activity of HMG CoA reductase. This inhibition may be by feedback inhibition or repression of the transcription of the gene encoding the enzyme via activation of the

  7. In vitro evaluation of bacteriocin-like inhibitory substances produced by lactic acid bacteria isolated during traditional Sicilian cheese making

    Giusi Macaluso

    2016-02-01

    Full Text Available Bacteriocins are antimicrobial proteins produced by bacteria that inhibit the growth of other bacteria with a bactericidal or bacteriostatic mode of action. Many lactic acid bacteria (LAB produce a high diversity of different bacteriocins. Bacteriocinogenic LAB are generally recognised as safe (GRAS and useful to control the frequent development of pathogens and spoilage microorganisms. For this reason they are commonly used as starter cultures in food fermentations. In this study, the authors describe the results of a screening on 699 LAB isolated from wooden vat surfaces, raw milk and traditional Sicilian cheeses, for the production of bacteriocin-like inhibitory substances, by comparing two alternative methods. The antagonistic activity of LAB and its proteinaceous nature were evaluated using the spot-on-the-lawn and the well-diffusion assay (WDA and the sensitivity to proteolytic (proteinase K, protease B and trypsin, amylolytic (α-amylase and lipolytic (lipase enzymes. The indicator strains used were: Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, Salmonella enteritidis. A total of 223 strains (belonging to the species Enterococcus spp., Lactobacillus spp., Pediococcus spp., Streptococcus spp., Leuconostoc spp. and Lactococcus lactis were found to inhibit the growth of Listeria monocytogenes by using the spot-on-the-lawn method; only 37 of these were confirmed by using the WDA. The direct addition of bacteriocin-producing cultures into dairy products can be a more practical and economic option for the improvement of the safety and quality of the final product.

  8. Effects of acetic acid and lactic acid on physicochemical characteristics of native and cross-linked wheat starches.

    Majzoobi, Mahsa; Beparva, Paniz

    2014-03-15

    The effects of two common organic acids; lactic and acetic acids (150 mg/kg) on physicochemical properties of native and cross-linked wheat starches were investigated prior and after gelatinization. These acids caused formation of some cracks and spots on the granules. The intrinsic viscosity of both starches decreased in the presence of the acids particularly after gelatinization. Water solubility increased while water absorption reduced after addition of the acids. The acids caused reduction in gelatinization temperature and enthalpy of gelatinization of both starches. The starch gels became softer, less cohesive, elastic and gummy when acids were added. These changes may indicate the degradation of the starch molecules by the acids. Cross-linked wheat starch was more resistant to the acids. However, both starches became more susceptible to the acids after gelatinization. The effect of lactic acid on physicochemical properties of both starches before and after gelatinization was greater than acetic acid. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. The Effect of MSG (Monosodium Glutamate Addition on The Quality of Yoghurt Frozen Culture Starter Viewed Viability, pH Value and Acidity

    Aris Sri Widati

    2012-02-01

    Full Text Available The objective of this study was to investigate wether the effect of percentage monosodium glutamat addition on the quality of yoghurt frozen culture starter viewed viability, pH value and acidity.The experimental design used in this study was Randomised Complete Design and the treatment were four levels of monosodium glutamate concentration respectively 0% (without monosodium glutamat 10%, 15% and 20% from medium. Each treatment were three times replicated. The research result showed that the difference of monosodium glutamate concentration  did not gave a significant effect (P>0.05 on viability of yoghurt frozen culture starter and acidity of yoghurt made by frozen culture starter but it gave a significant effect (P<0.05 on pH value. It can be concluded that different monosodium glutamate concentration had a different quality on frozen culture starter yoghurt. The addition of monosodium glutamate up to 20% necessarily indicate increase on quality of yoghurt frozen culture starter. Keywords: culture starter yoghurt, freezing, cryoprotectant

  10. Identification of Lactic Acid Bacteria and Propionic Acid Bacteria using FTIR Spectroscopy and Artificial Neural Networks

    Beata Nalepa

    2012-01-01

    Full Text Available In the present study, lactic acid bacteria and propionic acid bacteria have been identified at the genus level with the use of artificial neural networks (ANNs and Fourier transform infrared spectroscopy (FTIR. Bacterial strains of the genera Lactobacillus, Lactococcus, Leuconostoc, Streptococcus and Propionibacterium were analyzed since they deliver health benefits and are routinely used in the food processing industry. The correctness of bacterial identification by ANNs and FTIR was evaluated at two stages. At first stage, ANNs were tested based on the spectra of 66 reference bacterial strains. At second stage, the evaluation involved 286 spectra of bacterial strains isolated from food products, deposited in our laboratory collection, and identified by genus-specific PCR. ANNs were developed based on the spectra and their first derivatives. The most satisfactory results were reported for the probabilistic neural network, which was built using a combination of W5W4W3 spectral ranges. This network correctly identified the genus of 95 % of the lactic acid bacteria and propionic acid bacteria strains analyzed.

  11. Determination of dissociation constants or propionic acid and lactic acid (2-hydroxypropionic acid) by potentiometry and conductometry

    Saeeduddin; Khanzada, A.W.K.

    2004-01-01

    Dissociation constants of propionic acid and 2-hydroxypropionic acid (lactic acid) have been studied at different temperatures between 25 to 50 deg. C interval. Propionic acid is analyzed by conductometry while 2-hydroxypropionic acid is analyzed by potentiometry. Both investigated compounds are symmetrical carboxylic acids having same length of carbon chain but are markedly different in ionic behavior. We were interested to see how the hydroxyl group (-OH) induction in propionic acid affects on pKa values of 2-hydroxypropionic acid. We observed that as temperature increases pKa values increase. The increase is observed for both the investigated compounds. PKa values of 2-hydroxypropionic acid are lower as compared to propionic acid because of electron withdrawing (-OH). (author)

  12. Genotypic characterization and safety assessment of lactic acid bacteria from indigenous African fermented food products

    Adimpong David B

    2012-05-01

    Full Text Available Abstract Background Indigenous fermented food products play an essential role in the diet of millions of Africans. Lactic acid bacteria (LAB are among the predominant microbial species in African indigenous fermented food products and are used for different applications in the food and biotechnology industries. Numerous studies have described antimicrobial susceptibility profiles of LAB from different parts of the world. However, there is limited information on antimicrobial resistance profiles of LAB from Africa. The aim of this study was to characterize 33 LAB previously isolated from three different African indigenous fermented food products using (GTG5-based rep-PCR, sequencing of the 16S rRNA gene and species-specific PCR techniques for differentiation of closely related species and further evaluate their antibiotic resistance profiles by the broth microdilution method and their haemolytic activity on sheep blood agar plates as indicators of safety traits among these bacteria. Results Using molecular biology based methods and selected phenotypic tests such as catalase reaction, CO2 production from glucose, colonies and cells morphology, the isolates were identified as Lactobacillus delbrueckii, Lactobacillus fermentum, Lactobacillus ghanensis, Lactobacillus plantarum, Lactobacillus salivarius, Leuconostoc pseudomesenteroides, Pediococcus acidilactici, Pediococcus pentosaceus and Weissella confusa. The bacteria were susceptible to ampicillin, chloramphenicol, clindamycin and erythromycin but resistant to vancomycin, kanamycin and streptomycin. Variable sensitivity profiles to tetracycline and gentamicin was observed among the isolates with Lb. plantarum, Lb. salivarius, W. confusa (except strain SK9-5 and Lb. fermentum strains being susceptible to tetracycline whereas Pediococcus strains and Lb. ghanensis strains were resistant. For gentamicin, Leuc. pseudomesenteroides, Lb. ghanensis and Ped. acidilactici strains were resistant to 64

  13. Diversity of lactic acid bacteria associated with traditional fermented dairy products in Mongolia.

    Yu, J; Wang, W H; Menghe, B L G; Jiri, M T; Wang, H M; Liu, W J; Bao, Q H; Lu, Q; Zhang, J C; Wang, F; Xu, H Y; Sun, T S; Zhang, H P

    2011-07-01

    Spontaneous milk fermentation has a long history in Mongolia, and beneficial microorganisms have been handed down from one generation to the next for use in fermented dairy products. The objective of this study was to investigate the diversity of lactic acid bacteria (LAB) communities in fermented yak, mare, goat, and cow milk products by analyzing 189 samples collected from 13 different regions in Mongolia. The LAB counts in these samples varied from 3.41 to 9.03 log cfu/mL. Fermented yak and mare milks had almost identical mean numbers of LAB, which were significantly higher than those in fermented goat milk but slightly lower than those in fermented cow milk. In total, 668 isolates were obtained from these samples using de Man, Rogosa, and Sharpe agar and M17 agar. Each isolate was considered to be presumptive LAB based on gram-positive and catalase-negative properties, and was identified at the species level by 16S rRNA gene sequencing, multiplex PCR assay, and restriction fragment length polymorphism analysis. All isolates from Mongolian dairy products were accurately identified as Enterococcus faecalis (1 strain), Enterococcus durans (3 strains), Lactobacillus brevis (3 strains), Lactobacillus buchneri (2 strains), Lactobacillus casei (16 strains), Lactobacillus delbrueckii ssp. bulgaricus (142 strains), Lactobacillus diolivorans (17 strains), Lactobacillus fermentum (42 strains), Lactobacillus helveticus (183 strains), Lactobacillus kefiri (6 strains), Lactobacillus plantarum ssp. plantarum (7 strains), Lactococcus lactis ssp. lactis (7 strains), Leuconostoc lactis (22 strains), Leuconostoc mesenteroides (21 strains), Streptococcus thermophilus (195 strains), and Weissella cibaria (1 strain). The predominant LAB were Strep. thermophilus and Lb. helveticus, which were isolated from all sampling sites. The results demonstrate that traditional fermented dairy products from different regions of Mongolia have complex compositions of LAB species. Such diversity of

  14. [Identification of lactic acid bacteria in commercial yogurt and their antibiotic resistance].

    Qin, Yuxuan; Li, Jing; Wang, Qiuya; Gao, Kexin; Zhu, Baoli; Lv, Na

    2013-08-04

    To identify lactic acid bacteria (LAB) in commercial yogurts and investigate their antibiotic resistance. LABs were cultured from 5 yogurt brands and the isolates were identified at the species level by 16S rRNA sequence. Genotyping was performed by repetitive extragenic palindromic PCR (rep-PCR). The sensitivity to 7 antibiotics was tested for all LAB isolates by Kirby-Bauer paper diffusion (K-B method). Meanwhile, 9 antibiotic resistance genes (ARGs), including erythromycin resistance genes (ermA and ermB) and tetracycline resistance genes (tetM, tetK, tetS, tetQ, tetO, tetL and tetW), were detected by PCR amplification in the identified LAB isolates. The PCR products were confirmed by sequencing. Total 100 LABs were isolated, including 23 Lactobacillus delbrueckii ssp. bulgaricus, 26 Lactobacillus casei, 30 Streptococcus thermophilus, 5 Lactobacillus acidophilus, 6 Lactobacillus plantarum, and 10 Lactobacillus paracasei. The drug susceptibility test shows that all 100 isolates were resistant to gentamicin and streptomycin, 42 isolates were resistant to vancomycin, and on the contrary all were sensitive to cefalexin, erythromycin, tetracycline and oxytetracycline. Moreover, 5 ARGs were found in the 28 sequencing confirmed isolates, ermB gene was detected in 8 isolates, tet K in 4 isolates, tetL in 2 isolates, tetM in 4 isolates, tetO in 2 isolates. erm A, tet S, tet Q and tet W genes were not detected in the isolates. Antibiotic resistance genes were found in 53.57% (15/28) sequenced isolates, 2 -3 antibiotic resistance genes were detected in 4 isolates of L. delbrueckii ssp. bulgaricus. Some LABs were not labeled in commercial yogurt products. Antibiotic resistance genes tend to be found in the starter culture of L. delbrueckii ssp. Bulgaricus and S. thermophilus. All the LAB isolates were sensitive to erythromycin and tetracycline, even though some carried erythromycin and/or tetracycline resistance genes. We proved again that LAB could carry antibiotic

  15. Detoxification of Sap from Felled Oil Palm Trunks for the Efficient Production of Lactic Acid.

    Kunasundari, Balakrishnan; Arai, Takamitsu; Sudesh, Kumar; Hashim, Rokiah; Sulaiman, Othman; Stalin, Natra Joseph; Kosugi, Akihiko

    2017-09-01

    The availability of fermentable sugars in high concentrations in the sap of felled oil palm trunks and the thermophilic nature of the recently isolated Bacillus coagulans strain 191 were exploited for lactic acid production under non-sterile conditions. Screening indicated that strain 191 was active toward most sugars including sucrose, which is a major component of sap. Strain 191 catalyzed a moderate conversion of sap sugars to lactic acid (53%) with a productivity of 1.56 g/L/h. Pretreatment of oil palm sap (OPS) using alkaline precipitation improved the sugar fermentability, providing a lactic acid yield of 92% and productivity of 2.64 g/L/h. To better characterize potential inhibitors in the sap, phenolic, organic, and mineral compounds were analyzed using non-treated sap and saps treated with activated charcoal and alkaline precipitation. Phthalic acid, 3,4-dimethoxybenzoic acid, aconitic acid, syringic acid, and ferulic acid were reduced in the sap after treatment. High concentrations of Mg, P, K, and Ca were also precipitated by the alkaline treatment. These results suggest that elimination of excess phenolic and mineral compounds in OPS can improve the fermentation yield. OPS, a non-food resource that is readily available in bulk quantities from plantation sites, is a promising source for lactic acid production.

  16. Utilization of Encapsulated CaCO_3 in Liquid Core Capsules for Improving Lactic Acid Fermentation

    Boon-Beng, Lee; Nurul Ainina Zulkifli

    2016-01-01

    Lactic acid bacteria (LAB) have been used for food fermentation due to its fermentative ability to improve and enhance the quality of the end food products. However, the performance of LAB is affected as fermentation time elapsed because the microbial growth is inhibited by its end product, for example lactic acid. In this study, a new approach was introduced to reduce the product inhibition effect using CaCO_3 which is encapsulated in spherical liquid core capsules of diameter 3.5 mm and 3.6 mm produced through extrusion dripping method. The results showed that the pH and lactic acid concentration of LAB fermentation was well maintained by the capsules. The results of the fermentation conducted to control pH and lactic acid concentration using the capsules were better than those of the control set and comparable with that of the free CaCO_3 set. In addition, the viable cell concentration of L. casei shirota was high at the end of fermentation when the fermentation was conducted using the capsules. The results of this study suggested that the capsules have high potential to be applied for pH and lactic acid level control in LAB fermentation for various productions. (author)

  17. Batch fermentation of whey ultra filtrate by Lactobacillus helveticus for lactic acid production

    Roy, D; Goulet, J; Le Duy, Q

    1986-06-01

    Cheese whey ultrafiltrate (WU) was used as the carbon source for the production of lactic acid by batch fermentation with Lactobacillus helveticus strain milano. The fermentation was conducted in a 400 ml fermentor at an agitation rate of 200 revolutions per minute and under conditions of controlled temperature (42 degrees C) and pH. In the whey ultrafiltrate-corn steep liquor (WU-CSL) medium, the optimal pH for fermentation was 5.9. Inoculum propagated in skim milk (SM) medium or in lactose synthetic (LS) medium resulted in the best performance in fermentation (in terms of growth, lactic acid production, lactic acid yield and maximum productivity of lactic acid), as compared to that propagated in glucose synthetic (GS) medium. The yeast extract ultrafiltrate (YEU) used as the nitrogen/growth factor source in the WU medium at 1.5% (w/v) gave the highest maximum productivity of lactic acid of 2.70 g/l-h, as compared to the CSL and the tryptone ultrafiltrate (TU). 27 references.

  18. Simultaneous Saccharification and Fermentation of Lactic Acid from Empty Fruit Bunch at High Solids Loading

    Nursia Hassan

    2016-03-01

    Full Text Available The production of value-added chemicals from the bioconversion of lignocellulose biomass has been considered a promising venture. In this study, microwave, alkali-pretreated empty fruit bunch (EFB was used as the substrate, utilizing pelletized filamentous Rhizopus oryzae NRRL 395 and cellulolytic enzymes for lactic acid production in a fed-batch simultaneous saccharification and fermentation (SSF process. Insoluble solids generally do not affect the SSF process until a certain concentration is exceeded. To achieve a high lactic acid concentration in the broth, a high solids loading was required to allow a higher rate of glucose conversion. However, the results revealed a decrease in the final lactic acid yield when running SSF at a massive insoluble solids level. High osmotic pressure in the medium led to poor cellular performance and caused the Rhizopus oryzae pellets to break down, affecting the lactic acid production. To improve the process performance, a fed-batch operation mode was used. The fed-batch operation was shown to facilitate higher lactic acid yield, compared with the SSF batch mode. Enzyme feeding, as well as substrate feeding, was also investigated as a means of enabling a higher dry matter content, with a high glucose conversion in SSF of cellulose-rich EFB.

  19. Characterization of lactic acid bacteria from local cow´s milk kefir

    Ismail, YS; Yulvizar, C.; Mazhitov, B.

    2018-03-01

    One of products from milk fermentation is kefir. It is made by adding kefir grains which are composed of lactic acid bacteria and yeast into milk. The lactic acid bacteria are a group of bacteria that produce antimicrobial substances and able to inhibit the growth of pathogenic bacteria. In this research, the lactic acid bacteria were isolated from Aceh local cow`s milk kefir to determine the genus of the isolates. The methods used in the characterization of lactic acid bacteria are colony morphology, cell morphology, and biochemical tests which includes a catalase test; 5%, 6.5%, and 10% salt endurance tests; 37°C and 14°C temperature endurance tests, SIM test, TSIA test, MR-VP test, and O/F test. Of the four isolates found from the cow’s milk kefir, two isolates were confirmed as lactic acid bacteria (isolates SK-1 and SK-4). Both isolates are Gram positive bacteria, and have negative catalase activity. From the observations of colony morphology, cell morphology, and biochemical tests, it was found that the genus of SK-1 is Lactobacillus and the genus of SK-4 is Enterococcus.

  20. Production of D- and L-Lactic Acid by Mono- and Mixed Cultures of Lactobacillus sp.

    Antonija Trontel

    2011-01-01

    Full Text Available Batch cultivation of monoculture of Lactobacillus sp. and two–strain mixed culture of Lactobacillus sp. and Lactobacillus amylovorus DSM 20531T was carried out with the aim of producing L-(+- and D-(–/L-(+-lactic acid to be implemented in poly(lactic acid polymer production. Metabolic capacity of two Lactobacillus strains to ferment different carbon sources (glucose, sucrose or soluble starch during cultivation in MRS medium at 40 °C, in a laboratory-scale stirred tank bioreactor was defined. Lactobacillus sp. showed similar affinity towards mono- and disaccharide substrates, which were homofermentatively converted mostly to L-(+-lactic acid. L. amylovorus DSM 20531T has been characterized as a D/L-lactate producer and it is capable of conducting simultaneous saccharification and fermentation. Due to the interaction of Lactobacillus sp. with L. amylovorus DSM 20531T, starch was hydrolysed and fermented to the mixture of L-(+- and D-(–-lactic acid. Modified Luedeking-Piret kinetics used for the description of substrate utilization, growth of mono- and mixed cultures and production of lactic acid stereoisomers showed good agreement with experimental data.

  1. Production of L-lactic acid from metabolically engineered strain of Enterobacter aerogenes ATCC 29007.

    Thapa, Laxmi Prasad; Lee, Sang Jun; Park, Chulhwan; Kim, Seung Wook

    2017-07-01

    In this study, L-lactic acid production was investigated from metabolically engineered strain of E. aerogenes ATCC 29007. The engineered strain E. aerogenes SUMI01 (Δpta) was generated by the deletion of phosphate acetyltransferase (pta) gene from the chromosome of E. aerogenes ATCC 29007 and deletion was confirmed by colony PCR. Under the optimized fermentation conditions, at 37°C and pH 6 for 84h, the L-lactic acid produced by engineered strain E. aerogenes SUMI01 (Δpta) in flask fermentation using 100g/L mannitol as the carbon source was 40.05g/L as compared to that of the wild type counterpart 20.70g/L. At the end of the batch fermentation in bioreactor the production of L-lactic acid reached to 46.02g/L and yield was 0.41g/g by utilizing 112.32g/L mannitol. This is the first report regarding the production of L-lactic acid from Enterobacter species. We believe that this result may provide valuable guidelines for further engineering Enterobacter strain for the improvement of L-lactic acid production. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Isolation of lactic acid bacteria with potential protective culture characteristics from fruits

    Hashim, Nurul Huda; Sani, Norrakiah Abdullah

    2015-09-01

    Lactic acid bacteria are also known as beneficial microorganisms abundantly found in fermented food products. In this study, lactic acid bacteria were isolated from fresh cut fruits obtained from local markets. Throughout the isolation process from 11 samples of fruits, 225 presumptive lactic acid bacteria were isolated on MRS agar medium. After catalase and oxidase tests, 149 resulted to fit the characteristics of lactic acid bacteria. Further identification using Gram staining was conducted to identify the Gram positive bacteria. After this confirmation, the fermentation characteristics of these isolates were identified. It was found that 87 (58.4%) isolates were heterofermentative, while the rest of 62 (41.6%) are homofermentative lactic acid bacteria. Later, all these isolates were investigated for the ability to inhibit growth of Staphylococcus aureus using agar spot assay method. Seven (4.7%) isolates showed strong antagonistic capacity, while 127 (85.2%) and 8 (5.4%) isolates have medium and weak antagonistic capacity, respectively. The other 7 (4.7%) isolates indicated to have no antagonistic effect on S. aureus. Results support the potential of LAB isolated in this study which showed strong antagonistic activity against S. aureus may be manipulated to become protective cultures in food products. While the homofermentative or heterofermentative LAB can be utilized in fermentation of food and non-food products depending on the by-products required during the fermentation.

  3. The effect of different physical forms of starter feed on rumen fermentation indicators and weight gain in calves after weaning

    Leoš Pavlata

    2017-01-01

    Full Text Available The aim of the study was to determine the effect of different physical forms of starter feed on rumen fermentation indicators of calves after weaning and their weight gain. The experiment was performed with Czech Fleckvieh calves after weaning. The calves were fed ad libitum completely pelleted starter feed or texturized starter feed with chopped straw. The rumen fluid samples were collected after a month of feeding the starter feeds. The calves were weighed monthly. The pH, total acidity, total volatile fatty acids, acetate, propionate, butyrate, lactic acid, ammonia and the number of rumen ciliate protozoa were determined in the rumen fluid samples. The calves receiving the starter feed with straw showed significantly higher rumen pH (6.24 ± 0.51 vs. 5.58 ± 0.30, total volatile fatty acids (98.02 ± 20.46 vs. 61.40 ± 26.51 mmol/l, molar proportion of acetate (61.20 ± 4.87 vs. 50.53 ± 4.66%, and the acetate:propionate ratio (2.38 ± 0.53 vs. 1.34 ± 0.18 and lower molar proportion of propionate (26.55 ± 4.48 vs. 37.92 ± 3.58% compared with the calves receiving pelleted starter feed. Average daily gain of the calves did not differ significantly. The feeding of starter feed with chopped straw compared with the pelleted starter feed led to better development of the rumen fermentation evaluated by rumen pH, by total volatile fatty acids production, and by the proportion and ratio of acetic and propionic acids. The feeding of starter feed with chopped straw reduced the occurrence of subacute ruminal acidosis in the weaned calves.

  4. Phylogenomic reconstruction of lactic acid bacteria: an update

    Yu Li

    2011-01-01

    Full Text Available Abstract Background Lactic acid bacteria (LAB are important in the food industry for the production of fermented food products and in human health as commensals in the gut. However, the phylogenetic relationships among LAB species remain under intensive debate owing to disagreements among different data sets. Results We performed a phylogenetic analysis of LAB species based on 232 genes from 28 LAB genome sequences. Regardless of the tree-building methods used, combined analyses yielded an identical, well-resolved tree topology with strong supports for all nodes. The LAB species examined were divided into two groups. Group 1 included families Enterococcaceae and Streptococcaceae. Group 2 included families Lactobacillaceae and Leuconostocaceae. Within Group 2, the LAB species were divided into two clades. One clade comprised of the acidophilus complex of genus Lactobacillus and two other species, Lb. sakei and Lb. casei. In the acidophilus complex, Lb. delbrueckii separated first, while Lb. acidophilus/Lb. helveticus and Lb. gasseri/Lb. johnsonii were clustered into a sister group. The other clade within Group 2 consisted of the salivarius subgroup, including five species, Lb. salivarius, Lb. plantarum, Lb. brevis, Lb. reuteri, Lb. fermentum, and the genera Pediococcus, Oenococcus, and Leuconostoc. In this clade, Lb. salivarius was positioned most basally, followed by two clusters, one corresponding to Lb. plantarum/Lb. brevis pair and Pediococcus, and the other including Oenococcus/Leuconostoc pair and Lb. reuteri/Lb. fermentum pair. In addition, phylogenetic utility of the 232 genes was analyzed to identify those that may be more useful than others. The genes identified as useful were related to translation and ribosomal structure and biogenesis (TRSB, and a three-gene set comprising genes encoding ultra-violet resistance protein B (uvrB, DNA polymerase III (polC and penicillin binding protein 2B (pbpB. Conclusions Our phylogenomic analyses

  5. Optimization of a biomimetic poly-(lactic acid) ligament scaffold

    Uehlin, Andrew F.

    The anterior cruciate ligament (ACL) is the most commonly injured ligament of the knee, often requiring orthopedic reconstruction using autograft or allograph tissue, both with significant disadvantages. As a result, tissue engineering an ACL replacement graft has been heavily investigated. The present study attempts to replicate the morphology and mechanical properties of the ACL using a nanomatrix composite of highly-aligned poly(lactic acid) (PLA) fibers with various surface and biochemical modifications. Additionally, this study attempts to recreate the natural mineralization gradient found at the ACL enthesis onto the scaffold, capable of inducing a favorable cellular response in vitro. Unidirectional electrospinning was used to create nanofibers of PLA, followed by an induced degradation of the nanofibers via 0.25M NaOH hydrolysis. The effects of the unidirectional electrospinning as well as the effects of NaOH hydrolysis on fiber alignment, fiber diameter, surface morphology, crystallinity, in vitro swelling, immobilization of fibrin, and mechanical properties were investigated, resulting in a modified morphology correlating to the microstructure of native ligament tissue with similar mechanical properties. Furthering the development of the PLA nanomatrix composite, a bioinkjet printer was used to immobilize nanoparticulate hydroxyapatite (HANP) on the surface of the scaffold. A series of 300pL droplets of HANP bioink were printed over a gradient pattern mimetic of (and spatially corresponding to) the mineralization gradient found over the microanatomy at the ACL enthesis. Proliferation and differentiation response of human mesenchymal stem cells (hMSCs) in vitro was assessed on a variety of conditions and combinations of the PLA nanofiber scaffold surface modifications (inclusive and exclusive of HANP, fibrin, and various time dependent NaOH treatments). It was found that a combinatory effect of the HANP gradient with fibrin on 20 minute NaOH treated PLA

  6. Evaluation of ginsenoside bioconversion of lactic acid bacteria isolated from kimchi

    Boyeon Park

    2017-10-01

    Conclusion: Ginsenoside Rg5 concentration of five LABs have ranged from ∼2.6 μg/mL to 6.5 μg/mL and increased in accordance with the incubation periods. Our results indicate that the enzymatic activity along with acidic condition contribute to the production of minor ginsenoside from lactic acid bacteria.

  7. Microbial export of lactic and 3-hydroxypropanoic acid : implications for industrial fermentation processes

    van Maris, AJA; Konings, WN; Pronk, Jack T.; Dijken, J.P. van

    2004-01-01

    Lactic acid and 3-hydroxypropanoic acid are industrially relevant microbial products. This paper reviews the current knowledge on export of these compounds from microbial cells and presents a theoretical analysis of the bioenergetics of different export mechanisms. It is concluded that export can be

  8. Equilibria and kinetics for reactive extraction of lactic acid using Alamine 336 in decanol

    Wasewar, Kailas L.; Heesink, Albertus B.M.; Versteeg, Geert; Pangarkar, Vishwas G.

    2002-01-01

    Lactic acid is an important commercial product and extracting this from aqueous solution is a growing requirement in fermentation-based industries. The design of an amine extraction process requires (i) equilibrium and (ii) kinetic data for the acid-amine (solvent) system used. The equilibrium

  9. Characterization and Application of Autochthonous Starter Cultures for Fresh Cheese Production

    Andreja Leboš Pavunc

    2012-01-01

    Full Text Available The use of commercial starter cultures in fresh cheese production from pasteurized milk results in the loss of typical characteristics of artisan fresh cheese due to the replacement of complex native microbiota with a defined starter culture. Hence, the aim of this research is to isolate and characterize dominant lactic acid bacteria (LAB in artisan fresh cheese and to evaluate their capacity as autochthonous starter cultures for fresh cheese production. Fifteen most prevalent Gram-positive, catalase-negative and asporogenous bacterial strains were selected for a more detailed characterization. Eleven lactic acid bacterial strains were determined to be homofermentative cocci and four heterofermentative lactobacilli. Further phenotypic and genotypic analyses revealed that those were two different LAB strains with high acidifying and proteolytic activity, identified as Lactobacillus fermentum A8 and Enterococcus faecium A7. These two autochthonous strains, alone or in combination with commercial starter, were used to produce different types of fresh cheese, which were evaluated by a panel. Conventional culturing, isolation, identification and PCR-denaturing gradient gel electrophoresis (PCR-DGGE procedures, applied to the total fresh cheese DNA extracts, were employed to define and monitor the viability of the introduced LAB strains and their effect on the final product characteristics. Production of fresh cheese using a combination of commercial starter culture and selected autochthonous strains resulted in improved sensorial properties, which were more similar to the ones of spontaneously fermented fresh cheese than to those of cheese produced with only starter culture or selected strains. After 10 days of storage, that cheese retained the best sensorial properties in comparison with all other types of cheese. The presence of inoculated autochthonous and starter cultures and their identification was demonstrated by DGGE analysis. The obtained

  10. Preservation of acidified cucumbers with a natural preservative combination of fumaric acid and allyl isothiocyanate that target lactic acid bacteria and yeasts

    Without the addition of preservative compounds cucumbers acidified with 150 mM acetic acid with pH adjusted to 3.5 typically undergo fermentation by lactic acid bacteria. Fumaric acid (20 mM) inhibited growth of Lactobacillus plantarum and the lactic acid bacteria present on fresh cucumbers, but sp...

  11. LPMOs in cellulase mixtures affect fermentation strategies for lactic acid production from lignocellulosic biomass.

    Müller, Gerdt; Kalyani, Dayanand Chandrahas; Horn, Svein Jarle

    2017-03-01

    Enzymatic catalysis plays a key role in the conversion of lignocellulosic biomass to fuels and chemicals such as lactic acid. In the last decade, the efficiency of commercial cellulase cocktails has increased significantly, in part due to the inclusion of lytic polysaccharide monooxygenases (LPMOs). However, the LPMOs' need for molecular oxygen to break down cellulose demands reinvestigations of process conditions. In this study, we evaluate the efficiency of lactic acid production from steam-exploded birch using an LPMO-containing cellulase cocktail in combination with lactic acid bacteria, investigating both separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF). While the SSF set up generally has been considered to be more efficient because it avoids sugar accumulation which may inhibit the cellulases, the SHF set up in our study yielded 26-32% more lactic acid than the SSF. This was mainly due to competition for oxygen between LPMOs and the fermenting organisms in the SSF process, which resulted in reduced LPMO activity and thus less efficient saccharification of the lignocellulosic substrate. By means of aeration it was possible to activate the LPMOs in the SSF, but less lactic acid was produced due to a shift in metabolic pathways toward production of acetic acid. Overall, this study shows that lactic acid can be produced efficiently from lignocellulosic biomass, but that the use of LPMO-containing cellulase cocktails in fermentation processes demands re-thinking of traditional process set ups due to the requirement of oxygen in the saccharification step. Biotechnol. Bioeng. 2017;114: 552-559. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  12. Screening local Lactobacilli from Iran in terms of production of lactic acid and identification of superior strains

    Fatemeh Soleimanifard

    2015-12-01

    Full Text Available Introduction: Lactobacilli are a group of lactic acid bacteria that their final product of fermentation is lactic acid. The objective of this research is selection of local Lactobacilli producing L (+ lactic acid. Materials and methods: In this research the local strains were screened based on the ability to produce lactic acid. The screening was performed in two stages. The first stage was the titration method and the second stage was the enzymatic method. The superior strains obtained from titration method were selected to do enzymatic test. Finally, the superior strains in the second stage (enzymatic which had the ability to produce L(+ lactic acid were identified by biochemical tests. Then, molecular identification of strains was performed by using 16S rRNA sequencing. Results: In this study, the ability of 79 strains of local Lactobacilli in terms of production of lactic acid was studied. The highest and lowest rates of lactic acid production was 34.8 and 12.4 mg/g. Superior Lactobacilli in terms of production of lactic acid ability of producing had an optical isomer L(+, the highest levels of L(+ lactic acid were with 3.99 and the lowest amount equal to 1.03 mg/g. The biochemical and molecular identification of superior strains showed that strains are Lactobacillus paracasei. Then the sequences of 16S rRNA of superior strains were reported in NCBI with accession numbers KF735654، KF735655، KJ508201and KJ508202. Discussion and conclusion: The amounts of lactic acid production by local Lactobacilli were very different and producing some of these strains on available reports showed more products. The results of this research suggest the use of superior strains of Lactobacilli for production of pure L(+ lactic acid.

  13. Screening of Lactic Acid Bacteria Isolated from Iranian sourdoughs for Antifungal Activity: Enterococcus faecium showed the Most Potent Antifungal Activity in Bread

    Alam Taghi-Zadeh

    2017-09-01

    Full Text Available Background and Objective: The use of antifungal lactic acid bacteria as starter for bread making could be a good alternative to improve the stability of bread shelf life.Material and Methods: In this study, a total of 57 lactic acid bacteria were isolated from spontaneously fermented wheat sourdoughs collected in Chahar-Mahalo Bakhryari province of Iran. The isolates were screened for in vitro antifungal activity (towards Aspergilus niger or Penicillium roqueforti; and the selected isolates (six isolates were applied in flat bread making. The freshly baked breads were nebulized with a suspension of either molds, containing 104 spores ml-1, and the fungal growth on breads was monitored over a 7-day storage period.Results and Conclusion: Bread produced with either isolates AN3 and MB1 (both were identified as Enterococcus faecium restrained the growth of Aspergillus niger for up to 5 days. Even though none of the isolates were strong enough to inhibit the growth of Penicillium roquforti on bread, the surface area of breads contaminated by this fungus was significantly lower than the control samples. To our knowledge, it was the first report indicating the anti-mold activity of Enterococcus faecium strains isolated from sourdough. These isolates seem to be promising for further analysis and their application in bread industry for prolonging the shelf life.Conflict of interest: The authors declare that there is no conflict of interest.

  14. Complete Genome Sequence of a thermotolerant sporogenic lactic acid bacterium, Bacillus coagulans strain 36D1

    Rhee, Mun Su [University of Florida, Gainesville; Moritz, Brelan E. [University of Florida, Gainesville; Xie, Gary [Los Alamos National Laboratory (LANL); Glavina Del Rio, Tijana [U.S. Department of Energy, Joint Genome Institute; Dalin, Eileen [U.S. Department of Energy, Joint Genome Institute; Tice, Hope [U.S. Department of Energy, Joint Genome Institute; Bruce, David [Los Alamos National Laboratory (LANL); Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Chertkov, Olga [Los Alamos National Laboratory (LANL); Brettin, Thomas S [ORNL; Han, Cliff [Los Alamos National Laboratory (LANL); Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Patel, Milind [University of Florida, Gainesville; Ou, Mark [University of Florida, Gainesville; Harbrucker, Roberta [University of Florida, Gainesville; Ingram, Lonnie O. [University of Florida; Shanmugam, Keelnathan T. [University of Florida

    2011-01-01

    Bacillus coagulans is a ubiquitous soil bacterium that grows at 50-55 C and pH 5.0 and fer- ments various sugars that constitute plant biomass to L (+)-lactic acid. The ability of this spo- rogenic lactic acid bacterium to grow at 50-55 C and pH 5.0 makes this organism an attrac- tive microbial biocatalyst for production of optically pure lactic acid at industrial scale not only from glucose derived from cellulose but also from xylose, a major constituent of hemi- cellulose. This bacterium is also considered as a potential probiotic. Complete genome se- quence of a representative strain, B. coagulans strain 36D1, is presented and discussed.

  15. Complete Genome Sequence of a thermotolerant sporogenic lactic acid bacterium, Bacillus coagulans strain 36D1

    Xie, Gary [Los Alamos National Laboratory (LANL); Dalin, Eileen [U.S. Department of Energy, Joint Genome Institute; Tice, Hope [U.S. Department of Energy, Joint Genome Institute; Chertkov, Olga [Los Alamos National Laboratory (LANL); Land, Miriam L [ORNL

    2011-01-01

    Bacillus coagulans is a ubiquitous soil bacterium that grows at 50-55 C and pH 5.0 and fer-ments various sugars that constitute plant biomass to L (+)-lactic acid. The ability of this sporogenic lactic acid bacterium to grow at 50-55 C and pH 5.0 makes this organism an attractive microbial biocatalyst for production of optically pure lactic acid at industrial scale not only from glucose derived from cellulose but also from xylose, a major constituent of hemi-cellulose. This bacterium is also considered as a potential probiotic. Complete genome squence of a representative strain, B. coagulans strain 36D1, is presented and discussed.

  16. Lactic Acid Bacteria Exopolysaccharides in Foods and Beverages: Isolation, Properties, Characterization, and Health Benefits.

    Lynch, Kieran M; Zannini, Emanuele; Coffey, Aidan; Arendt, Elke K

    2018-03-25

    Exopolysaccharides produced by lactic acid bacteria are a diverse group of polysaccharides produced by many species. They vary widely in their molecular, compositional, and structural characteristics, including mechanisms of synthesis. The physiochemical properties of these polymers mean that they can be exploited for the sensorial and textural enhancement of a variety of food and beverage products. Traditionally, lactic acid bacteria exopolysaccharides have an important role in fermented dairy products and more recently are being applied for the improvement of bakery products. The health benefits that are continually being associated with these polysaccharides enable the development of dual function, added-value, and clean-label products. To fully exploit and understand the functionality of these exopolysaccharides, their isolation, purification, and thorough characterization are of great importance. This review considers each of the above factors and presents the current knowledge on the importance of lactic acid bacteria exopolysaccharides in the food and beverage industry.

  17. Lactic acid production on liquid distillery stillage by Lactobacillus rhamnosus immobilized onto zeolite.

    Djukić-Vuković, Aleksandra P; Mojović, Ljiljana V; Jokić, Bojan M; Nikolić, Svetlana B; Pejin, Jelena D

    2013-05-01

    In this study, lactic acid and biomass production on liquid distillery stillage from bioethanol production with Lactobacillus rhamnosus ATCC 7469 was studied. The cells were immobilized onto zeolite, a microporous aluminosilicate mineral and the lactic acid production with free and immobilized cells was compared. The immobilization allowed simple cell separation from the fermentation media and their reuse in repeated batch cycles. A number of viable cells of over 10(10) CFU g(-1) of zeolite was achieved at the end of fourth fermentation cycle. A maximal process productivity of 1.69 g L(-1), maximal lactic acid concentration of 42.19 g L(-1) and average yield coefficient of 0.96 g g(-1) were achieved in repeated batch fermentation on the liquid stillage without mineral or nitrogen supplementation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Characterization of Lactic Acid Bacteria (LAB) isolated from Indonesian shrimp paste (terasi)

    Amalia, U.; Sumardianto; Agustini, T. W.

    2018-02-01

    Shrimp paste was one of fermented products, popular as a taste enhancer in many dishes. The processing of shrimp paste was natural fermentation, depends on shrimp it self and the presence of salt. The salt inhibits the growth of undesirable microorganism and allows the salt-tolerant lactic acid bacteria (LAB) to ferment the protein source to lactic acids. The objectives of this study were to characterize LAB isolated from Indonesian shrimp paste or "Terasi" with different times of fermentation (30, 60 and 90 days). Vitech analysis showed that there were four strains of the microorganism referred to as lactic acid bacteria (named: LABS1, LABS2, LABS3 and LABS4) with 95% sequence similarity. On the basis of biochemical, four isolates represented Lactobacillus, which the name Lactobacillus plantarum is proposed. L.plantarum was play role in resulting secondary metabolites, which gave umami flavor in shrimp paste.

  19. Complete Genome Sequence of a thermotolerant sporogenic lactic acid bacterium, Bacillus coagulans strain 36D1

    Rhee, Mun Su; Moritz, Brélan E.; Xie, Gary; Glavina del Rio, T.; Dalin, E.; Tice, H.; Bruce, D.; Goodwin, L.; Chertkov, O.; Brettin, T.; Han, C.; Detter, C.; Pitluck, S.; Land, Miriam L.; Patel, Milind; Ou, Mark; Harbrucker, Roberta; Ingram, Lonnie O.; Shanmugam, K. T.

    2011-01-01

    Bacillus coagulans is a ubiquitous soil bacterium that grows at 50-55 °C and pH 5.0 and ferments various sugars that constitute plant biomass to L (+)-lactic acid. The ability of this sporogenic lactic acid bacterium to grow at 50-55 °C and pH 5.0 makes this organism an attractive microbial biocatalyst for production of optically pure lactic acid at industrial scale not only from glucose derived from cellulose but also from xylose, a major constituent of hemicellulose. This bacterium is also considered as a potential probiotic. Complete genome sequence of a representative strain, B. coagulans strain 36D1, is presented and discussed. PMID:22675583

  20. Influence of Heavy Metal Powders on Rheological Properties of Poly(Lactic Acid)

    Lebedev, S. M.; Gefle, O. S.; Amitov, E. T.; Berchuk, D. Yu.; Zhuravlev, D. V.

    2017-08-01

    Main properties of poly(lactic acid) (PLA) and composite materials on its basis filled with tungsten and lead powders are investigated. An anomalous decrease of the viscosity of melts of poly(lactic acid)/tungsten and poly(lactic acid)/lead composites is detected. The methods of differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and IR spectroscopy are used for investigation. It is shown that the temperature at which the composites filled with tungsten and lead begin to melt decreases by more than 8 and 3°C in comparison with neat PLA. Our investigations show impossibility of preparing radiation resistant polymer composites based on PLA filled with tungsten and lead powders.

  1. Fermentation of Prefermented and Extruded Rice Flour by Lactic Acid Bacteria from Sikhae

    Lee, C. H.; Min, K. C.; Souane, M.

    1992-01-01

    of prefermentation of rice flour in solid-state with Bacillus laevolacticus and Saccharomyces cerevisiae, extrusion cooking and addition of soymilk as the substrate of lactic acid fermentation were tested. Extrusion cooking and prefermentation of rice increased the soluble solid and sugar contents before malt......The acid- and flavor-forming properties of Lactobacillus plantarum and Leuconostoc mesenteroides isolated from Sikhae, a Korean traditional lactic acid fermented fish product, were examined and compared to those of Lactobacillus casei and Lactococcus lactis subsp. diacetylactis DRC3. The effects...... digestion. The amount of sugar consumption during lactic fermentation varied with the type of bacteria. Leuconostoc mesenteroides(sikhae) and Lactobacillus plantarum(sikhae) increased up to 6 times of original cell number by 24 hrs of fermentation in rice + soymilk substrate, but Lactococcus lactis...

  2. Comparative analysis of microbial community of novel lactic acid fermentation inoculated with different undefined mixed cultures.

    Liang, Shaobo; Gliniewicz, Karol; Mendes-Soares, Helena; Settles, Matthew L; Forney, Larry J; Coats, Erik R; McDonald, Armando G

    2015-03-01

    Three undefined mixed cultures (activated sludge) from different municipal wastewater treatment plants were used as seeds in a novel lactic acid fermentation process fed with potato peel waste (PPW). Anaerobic sequencing batch fermenters were run under identical conditions to produce predominantly lactic acid. Illumina sequencing was used to examine the 16S rRNA genes of bacteria in the three seeds and fermenters. Results showed that the structure of microbial communities of three seeds were different. All three fermentation products had unique community structures that were dominated (>96%) by species of the genus Lactobacillus, while members of this genus constituted undefined mixed cultures were robust and resilient, which provided engineering prospects for the microbial utilization of carbohydrate wastes to produce lactic acid. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Mass transfer behavior in lactic acid fermentation using immobilized lactobacillus delbrueckii

    Wang, H.; Seki, M.; Furusaki, S. [The University of Tokyo, Tokyo (Japan). Faculty of Engineering

    1995-08-20

    We performed simulation studies on mass transfer behavior for immobilized cells in lactic acid fermentation using the mathematical model developed previously. The simulations pointed to an unusual result; that lactate ion diffuses into the bead center from outside during the batch fermentation and the startup period of the continuous fermentation, whereas free lactic acid and protons diffuse in the opposite direction. This phenomenon is caused by the addition of base to keep pH constant in the broth. Also, using an appropriate buffer to control pH in the broth can reduce the inward diffusion of lactate ion and improve the productivity of lactic acid. A singular mass transfer phenomenon is expected to take place in other production processes using immobilized cells (or enzyme), where alkali solution is added to broth to keep pH constant. 9 refs., 6 figs.

  4. Production of lactic acid from hemicellulose extracts by Bacillus coagulans MXL-9.

    Walton, Sara L; Bischoff, Kenneth M; van Heiningen, Adriaan R P; van Walsum, G Peter

    2010-08-01

    Bacillus coagulans MXL-9 was found capable of growing on pre-pulping hemicellulose extracts, utilizing all of the principle monosugars found in woody biomass. This organism is a moderate thermophile isolated from compost for its pentose-utilizing capabilities. It was found to have high tolerance for inhibitors such as acetic acid and sodium, which are present in pre-pulping hemicellulose extracts. Fermentation of 20 g/l xylose in the presence of 30 g/l acetic acid required a longer lag phase but overall lactic acid yield was not diminished. Similarly, fermentation of xylose in the presence of 20 g/l sodium increased the lag time but did not affect overall product yield, though 30 g/l sodium proved completely inhibitory. Fermentation of hot water-extracted Siberian larch containing 45 g/l total monosaccharides, mainly galactose and arabinose, produced 33 g/l lactic acid in 60 h and completely consumed all sugars. Small amounts of co-products were formed, including acetic acid, formic acid, and ethanol. Hemicellulose extract formed during autohydrolysis of mixed hardwoods contained mainly xylose and was converted into lactic acid with a 94% yield. Green liquor-extracted hardwood hemicellulose containing 10 g/l acetic acid and 6 g/l sodium was also completely converted into lactic acid at a 72% yield. The Bacillus coagulans MXL-9 strain was found to be well suited to production of lactic acid from lignocellulosic biomass due to its compatibility with conditions favorable to industrial enzymes and its ability to withstand inhibitors while rapidly consuming all pentose and hexose sugars of interest at high product yields.

  5. Characterization of airag collected in Ulaanbaatar, Mongolia with emphasis on isolated lactic acid bacteria.

    Choi, Suk-Ho

    2016-01-01

    Airag, alcoholic sour-tasting beverage, has been traditionally prepared by Mongolian nomads who naturally ferment fresh mares' milk. Biochemical and microbiological compositions of airag samples collected in Ulaanbaatar, Mongolia and physiological characteristics of isolated lactic acid bacteria were investigated. Protein composition and biochemical composition were determined using sodium dodecyl sulfate-gel electrophoresis and high performance liquid chromatography, respectively. Lactic acid bacteria were identified based on nucleotide sequence of 16S rRNA gene. Carbohydrate fermentation, acid survival, bile resistance and acid production in skim milk culture were determined. Equine whey proteins were present in airag samples more than caseins. The airag samples contained 0.10-3.36 % lactose, 1.44-2.33 % ethyl alcohol, 1.08-1.62 % lactic acid and 0.12-0.22 % acetic acid. Lactobacillus (L.) helveticus were major lactic acid bacteria consisting of 9 isolates among total 18 isolates of lactic acid bacteria. L. helveticus survived strongly in PBS, pH 3.0 but did not grow in MRS broth containing 0.1 % oxgall. A couple of L. helveticus isolates lowered pH of skim milk culture to less than 4.0 and produced acid up to more than 1.0 %. Highly variable biochemical compositions of the airag samples indicated inconsistent quality due to natural fermentation. Airag with low lactose content should be favorable for nutrition, considering that mares' milk with high lactose content has strong laxative effect. The isolates of L. helveticus which produced acid actively in skim milk culture might have a major role in production of airag.

  6. Characterization of airag collected in Ulaanbaatar, Mongolia with emphasis on isolated lactic acid bacteria

    Suk-Ho Choi

    2016-03-01

    Full Text Available Abstract Background Airag, alcoholic sour-tasting beverage, has been traditionally prepared by Mongolian nomads who naturally ferment fresh mares’ milk. Biochemical and microbiological compositions of airag samples collected in Ulaanbaatar, Mongolia and physiological characteristics of isolated lactic acid bacteria were investigated. Methods Protein composition and biochemical composition were determined using sodium dodecyl sulfate-gel electrophoresis and high performance liquid chromatography, respectively. Lactic acid bacteria were identified based on nucleotide sequence of 16S rRNA gene. Carbohydrate fermentation, acid survival, bile resistance and acid production in skim milk culture were determined. Results Equine whey proteins were present in airag samples more than caseins. The airag samples contained 0.10–3.36 % lactose, 1.44–2.33 % ethyl alcohol, 1.08–1.62 % lactic acid and 0.12–0.22 % acetic acid. Lactobacillus (L. helveticus were major lactic acid bacteria consisting of 9 isolates among total 18 isolates of lactic acid bacteria. L. helveticus survived strongly in PBS, pH 3.0 but did not grow in MRS broth containing 0.1 % oxgall. A couple of L. helveticus isolates lowered pH of skim milk culture to less than 4.0 and produced acid up to more than 1.0 %. Conclusion Highly variable biochemical compositions of the airag samples indicated inconsistent quality due to natural fermentation. Airag with low lactose content should be favorable for nutrition, considering that mares’ milk with high lactose content has strong laxative effect. The isolates of L. helveticus which produced acid actively in skim milk culture might have a major role in production of airag.

  7. Correlation between working positions and lactic acid levels with musculoskeletal complaints among dentists

    Fiory Dioptis Putriwijaya

    2016-12-01

    Full Text Available Background: Musculoskeletal complaints have been common for dentists since their body is unknowingly often in inappropriate positions when caring for patients. For example, they bend towards patients, suddenly move, and then rotate from one side to another. The repetitive movements are done in long term. High activities and sufficient recovery time can cause a buildup of lactic acid in their blood leading to obstruction of the energy intake from the aerobic system in their muscle cells, resulting in fatigue. As a result, such conditions trigger decreased muscle performances. Purpose: This study aimed to determine the correlation between working positions and lactic acid levels with the risk of musculoskeletal disorders among dentists at Public Health Centers in Surabaya. Method: This research was an analytical observational research using cross sectional approach. Sampling technique used in this research was cluster random sampling with nineteen samples. To evaluate the working positions of those samples, a rapid entire body assessment (REBA method was used. Meanwhile, to observe the musculoskeletal disorders of those samples, a Nordic body map was used. Data obtained then were analyzed using Pearson correlation test with a significance level (p<0.05. Result: Results of data analysis using the Pearson correlation test showed that the significance value obtained was 0.036. It indicates that there was a correlation between the working positions and the lactic acid levels with the musculoskeletal disorders in those dentists. The results of the Pearson correlation test also revealed that there was a correlation between the working positions and the lactic acid levels among those dentists with a significance value of 0.025. Conclusion: It may be concluded that the wrong body positions during working can increase lactic acid level in the body of dentists. The increased level of lactic acid then can affect their muscles, leading to the high risk of

  8. Water-lactose behavior as a function of concentration and presence of lactic acid in lactose model systems.

    Wijayasinghe, Rangani; Vasiljevic, Todor; Chandrapala, Jayani

    2015-12-01

    The presence of high amounts of lactic acid in acid whey restricts its ability to be further processed because lactose appears to remain in its amorphous form. A systematic study is lacking in this regard especially during the concentration step. Hence, the main aim of the study was to establish the structure and behavior of water molecules surrounding lactose in the presence of 1% (wt/wt) lactic acid at a concentration up to 50% (wt/wt). Furthermore, the crystallization nature of freeze-dried lactose with or without lactic acid was established using differential scanning calorimetry and Fourier transform infrared spectroscopy. Two mechanisms were proposed to describe the behavior of water molecules around lactose molecules during the concentration of pure lactose and lactose solutions with lactic acid. Pure lactose solution exhibited a water evaporation enthalpy of ~679 J·g(-1), whereas lactose+ lactic acid solution resulted in ~965 J·g(-1) at a 50% (wt/wt) concentration. This indicates a greater energy requirement for water removal around lactose in the presence of lactic acid. Higher crystallization temperatures were observed with the presence of lactic acid, indicating a delay in crystallization. Furthermore, less crystalline lactose (~12%) was obtained in the presence of lactic acid, indicating high amorphous nature compared with pure lactose where ~50% crystallinity was obtained. The Fourier transform infrared spectra revealed that the strong hydration layer consisting lactic acid and H3O(+) ions surrounded lactose molecules via strong H bonds, which restricted water mobility, induced a change in structure of lactose, or both, creating unfavorable conditions for lactose crystallization. Thus, partial or complete removal of lactic acid from acid whey may be the first step toward improving the ability of acid whey to be processed. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  9. Direct lactic acid fermentation of Jerusalem artichoke tuber extract using Lactobacillus paracasei without acidic or enzymatic inulin hydrolysis.

    Choi, Hwa-Young; Ryu, Hee-Kyoung; Park, Kyung-Min; Lee, Eun Gyo; Lee, Hongweon; Kim, Seon-Won; Choi, Eui-Sung

    2012-06-01

    Lactic acid fermentation of Jerusalem artichoke tuber was performed with strains of Lactobacillus paracasei without acidic or enzymatic inulin hydrolysis prior to fermentation. Some strains of L. paracasei, notably KCTC13090 and KCTC13169, could ferment hot-water extract of Jerusalem artichoke tuber more efficiently compared with other Lactobacillus spp. such as L. casei type strain KCTC3109. The L. paracasei strains could utilize almost completely the fructo-oligosaccharides present in Jerusalem artichoke. Inulin-fermenting L. paracasei strains produced c.a. six times more lactic acid compared with L. casei KCTC3109. Direct lactic fermentation of Jerusalem artichoke tuber extract at 111.6g/L of sugar content with a supplement of 5 g/L of yeast extract by L. paracasei KCTC13169 in a 5L jar fermentor produced 92.5 ce:hsp sp="0.25"/>g/L of lactic acid with 16.8 g/L fructose equivalent remained unutilized in 72 h. The conversion efficiency of inulin-type sugars to lactic acid was 98% of the theoretical yield. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Isolation, enumeration, molecular identification and probiotic potential evaluation of lactic acid bacteria isolated from sheep milk

    Acurcio, L.B.; Souza, M.R.; Nunes, A.C.; Oliveira, D.L.S.; Sandes, S.H.C.; Alvim, L.B.

    2014-01-01

    Lactic acid bacteria species were molecularly identified in milk from Lacaune, Santa Inês and crossbred sheep breeds and their in vitro probiotic potential was evaluated. The species identified were Enterococcus faecium (56.25%), E. durans (31.25%) and E. casseliflavus (12.5%). No other lactic acid bacteria species, such as lactobacilli, was identified. Most of the isolated enterococci were resistant to gastric pH (2.0) and to 0.3% oxgall. All tested enterococci were resistant to ceftazidime,...

  11. Synergistic Extraction of Lactic Acid with Tri-n-Octylamine and Try-n-Butylphosphate

    Matsumoto, Michiaki.; Yuba, Seiji.; Kondo, Kazuo. (Doshisha University, Department of Chemical Engineering and Materials Science (Japan))

    1998-12-01

    Synergistic extraction system of lactic acid is examined to develop to in situ extractive fermentation process. The addition of try-n-butyl phosphate(TBP) to the extraction system of lactic acid(HA) with tri-n-actylamine(TOA) diluted by hexane causes a large synergism. Extraction reaction with the mixed extractant is interpreted quite well based on the formation of mixed complex, HA[center dot]TOA[center dot]2TBP. Though the addition of hexane solution containing TBP and TOA to the culture of Lactobacillus rhamnosus results in low lactate production, some lactate is produced. (author)

  12. Synergistic Extraction of Lactic Acid with Tri-n-Octylamine and Try-n-Butylphosphate

    Matsumoto, Michiaki.; Yuba, Seiji.; Kondo, Kazuo. [Doshisha University, Department of Chemical Engineering and Materials Science (Japan)

    1998-12-01

    Synergistic extraction system of lactic acid is examined to develop to in situ extractive fermentation process. The addition of try-n-butyl phosphate(TBP) to the extraction system of lactic acid(HA) with tri-n-actylamine(TOA) diluted by hexane causes a large synergism. Extraction reaction with the mixed extractant is interpreted quite well based on the formation of mixed complex, HA{center_dot}TOA{center_dot}2TBP. Though the addition of hexane solution containing TBP and TOA to the culture of Lactobacillus rhamnosus results in low lactate production, some lactate is produced. (author)

  13. Non Invasive Microwave Sensor for the Detection of Lactic Acid in Cerebrospinal Fluid (CSF)

    Goh, J H; Mason, A; Al-Shamma'a, A I; Field, M; Shackcloth, M; Browning, P

    2011-01-01

    This research involves the use of a low power microwave sensor for analysis of lactic acid in cerebrospinal fluid (CSF), an indicator of neurological impairment during aortic aneurysm surgery which could provide the basis for improved treatment regimes and better quality of care with more efficient use of resources. This paper presents initial work using standard lactate curves in water followed by lactate in s ynthetic CSF . A multi-modal spectral signature has been defined for lactate, forming the basis for subsequent development of microwave sensor platform that is able to detect concentrations of lactic acid in CSF of volumes less than 1ml.

  14. Probiotic lactic acid bacteria – the fledgling cuckoos of the gut?

    Arnold Berstad

    2016-05-01

    Full Text Available It is tempting to look at bacteria from our human egocentric point of view and label them as either ‘good’ or ‘bad’. However, a microbial society has its own system of government – ‘microcracy’ – and its own rules of play. Lactic acid bacteria are often referred to as representatives of the good ones, and there is little doubt that those belonging to the normal intestinal flora are beneficial for human health. But we should stop thinking of lactic acid bacteria as always being ‘friendly’ – they may instead behave like fledgling cuckoos.

  15. Plasmids from Food Lactic Acid Bacteria: Diversity, Similarity, and New Developments

    Yanhua Cui

    2015-06-01

    Full Text Available Plasmids are widely distributed in different sources of lactic acid bacteria (LAB as self-replicating extrachromosomal genetic materials, and have received considerable attention due to their close relationship with many important functions as well as some industrially relevant characteristics of the LAB species. They are interesting with regard to the development of food-grade cloning vectors. This review summarizes new developments in the area of lactic acid bacteria plasmids and aims to provide up to date information that can be used in related future research.

  16. Plasmids from Food Lactic Acid Bacteria: Diversity, Similarity, and New Developments

    Cui, Yanhua; Hu, Tong; Qu, Xiaojun; Zhang, Lanwei; Ding, Zhongqing; Dong, Aijun

    2015-01-01

    Plasmids are widely distributed in different sources of lactic acid bacteria (LAB) as self-replicating extrachromosomal genetic materials, and have received considerable attention due to their close relationship with many important functions as well as some industrially relevant characteristics of the LAB species. They are interesting with regard to the development of food-grade cloning vectors. This review summarizes new developments in the area of lactic acid bacteria plasmids and aims to provide up to date information that can be used in related future research. PMID:26068451

  17. Lactobacilli inactivate Chlamydia trachomatis through lactic acid but not H2O2.

    Zheng Gong

    Full Text Available Lactobacillus species dominate the microbiome in the lower genital tract of most reproductive-age women. Producing lactic acid and H2O2, lactobacilli are believed to play an important role in prevention of colonization by and growth of pathogens. However, to date, there have been no reported studies characterizing how lactobacilli interact with Chlamydia trachomatis, a leading sexually transmitted bacterium. In this report, we demonstrate inactivation of C. trachomatis infectivity by culture media conditioned by Lactobacillus crispatus, L. gasseri and L. jensenii, known to be dominating organisms in the human vaginal microbiome. Lactobacillus still cultures produced lactic acid, leading to time- and concentration-dependent killing of C. trachomatis. Neutralization of the acidic media completely reversed chlamydia killing. Addition of lactic acid into Lactobacillus-unconditioned growth medium recapitulated the chlamydiacidal activity of conditioned media. The H2O2 concentrations in the still cultures were found to be comparable to those reported for the cervicovaginal fluid, but insufficient to inactivate chlamydiae. Aeration of Lactobacillus cultures by shaking markedly induced H2O2 production, but strongly inhibited Lactobacillus growth and lactic acid production, and thus severely affected acidification, leading to significantly reduced chlamydiacidal efficiency. These observations indicate lactobacilli inactivate chlamydiae primarily through maintaining acidity in a relatively hypoxic environment in the vaginal lumen with limited H2O2, which is consistent with the notion that women with higher vaginal pH are more prone to sexually transmitted C. trachomatis infection. In addition to lactic acid, formic acid and acetic acid also exhibited potent chlamydiacidal activities. Taken together, our findings imply that lowering the vaginal pH through engineering of the vaginal microbiome and other means will make women less susceptible to C

  18. Feasibility of converting lactic acid to ethanol in food waste fermentation by immobilized lactate oxidase

    Ma, Hong-zhi; Xing, Yi; Yu, Miao; Wang, Qunhui

    2014-01-01

    Highlights: • Residue lactic acid in food waste could be converted to pyruvic acid. • Calcium alginate immobilized the lactate oxidase with high pH and thermal stability. • Immobilized enzyme could convert 70% lactic acid to pyruvic acid. • Ethanol yield could be increased by 20% with lactate oxidase added. - Abstract: Adoption of lactic acid bacteria (LAB) into ethanol fermentation from food waste can replace the sterilization process. However, LAB inoculation will convert part of the substrate into lactic acid (LA), not ethanol. This study adopted lactate oxidase to convert the produced LA to pyruvate, and then ethanol fermentation was carried out. The immobilization enzyme was utilized, and corresponding optimum conditions were determined. Results showed that calcium alginate could successfully immobilize the enzyme and improve pH and thermal stability. The optimum pH and temperature were 6.2 and 55 °C, respectively. The utilization of immobilized enzyme with catalytic time of 5 h could convert 70% LA to pyruvate, and the addition of enzyme increased the ethanol yield by 20% more than that of the control. The process could be applied in food waste storage and can help in reducing carbon source consumption

  19. Lactic acid bacteria population dynamics during spontaneous fermentation of radish (Raphanus sativus L.) roots in brine.

    Pardali, Eleni; Paramithiotis, Spiros; Papadelli, Marina; Mataragas, Marios; Drosinos, Eleftherios H

    2017-06-01

    The aim of the present study was to assess the microecosystem development and the dynamics of the lactic acid bacteria population during spontaneous fermentation of radish (Raphanus sativus L.) roots in brine at 20 and 30 °C. In both temperatures, lactic acid bacteria prevailed the fermentation; as a result, the pH value was reduced to ca. 3.6 and total titrable acidity increased to ca. 0.4% lactic acid. Enterococci population increased and formed a secondary microbiota while pseudomonads, Enterobacteriaceae and yeasts/molds populations were below enumeration limit already before the middle of fermentation. Pediococcus pentosaceus dominated during the first days, followed by Lactobacillus plantarum that prevailed the fermentation until the end. Lactobacillus brevis was also detected during the final days of fermentation. A succession at sub-species level was revealed by the combination of RAPD-PCR and rep-PCR analyses. Glucose and fructose were the main carbohydrates detected in brine and were metabolized into lactic acid, acetic acid and ethanol.

  20. Prolonged local anesthetic action through slow release from poly (lactic acid co castor oil).

    Sokolsky-Papkov, Marina; Golovanevski, Ludmila; Domb, Abraham J; Weiniger, Carolyn F

    2009-01-01

    To evaluate a new formulation of bupivacaine loaded in an injectable fatty acid based biodegradable polymer poly(lactic acid co castor oil) in prolonging motor and sensory block when injected locally. The polyesters were synthesized from DL: -lactic acid and castor oil with feed ratio of 4:6 and 3:7 w/w. Bupivacaine was dispersed in poly(fatty ester) liquid and tested for drug release in vitro. The polymer p(DLLA:CO) 3:7 loaded with 10% bupivacaine was injected through a 22G needle close to the sciatic nerve of ICR mice and the duration of sensory and motor nerve blockade was measured. The DL: -lactic acid co castor oil p(DLLA:CO) 3:7 released 65% of the incorporated bupivacaine during 1 week in vitro. Single injection of 10% bupivacaine loaded into this polymer caused motor block that lasted 24 h and sensory block that lasted 48 h. Previously we developed a ricinoleic acid based polymer with incorporated bupivacaine which prolonged anesthesia to 30 h. The new polymer poly(lactic acid co castor oil) 3:7 provides slow release of effective doses of the incorporated local anesthetic agent and prolongs anesthesia to 48 h.