WorldWideScience

Sample records for producing lactic acid

  1. Exopolysaccharides produced by lactic acid bacteria

    NARCIS (Netherlands)

    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

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

    African Journals Online (AJOL)

    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 ...

  3. Purification of bacteriocins produced by lactic acid bacteria.

    Science.gov (United States)

    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.

  4. Bacteriocins produced by lactic acid bacteria: A review

    Directory of Open Access Journals (Sweden)

    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

  5. Lactic acid test

    Science.gov (United States)

    ... 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 exopolysaccharides-producing lactic acid bacteria ...

    African Journals Online (AJOL)

    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, ...

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

    Science.gov (United States)

    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

  8. Isolation and identification of antimicrobial-producing lactic acid ...

    African Journals Online (AJOL)

    , Proteus species, Staphylococcus aureus, Salmonella species, Pseudomonas flourescence, P. aeruginosa, Serratia species and Pediococcus acidilactici. Of the 42 antimicrobial producing isolates characterized, 16, 12, 6 and 8 were identified ...

  9. Selection of bacteriocin producer strains of lactic acid bacteria from a dairy environment.

    Science.gov (United States)

    Lasagno, M; Beoleito, V; Sesma, F; Raya, R; Font de Valdez, G; Eraso, A

    2002-01-01

    Two strains showing bacteriocin production were selected from a total of 206 lactic acid bacteria isolated from samples of milk, milk serum, whey and homemade cheeses in Southern Cordoba, Argentina. This property was detected by means of well diffusion assays. The strains were identified as Enterococcus hirae and Enterococcus durans. The protein nature of those substances was proved by showing their sensitivity to type IV and XXV proteases, papaine, trypsin, pepsin and K proteinase. The bacteriocins inhibited the growth of Listeria monocytogenes, Bacillus cereus, Clostridium perfringes and two strains of Staphylococcus aureus, an A-enterotoxin and a B-enterotoxin producers. All of these bacteria are common pathogens usually associated with food borne diseases (ETA). These lactic acid bacteria or their bacteriocins could be suitable candidates for food preservation and specially useful in the our regional dairy industry.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  12. Identification and quantification of antifungal compounds produced by lactic acid bacteria and propionibacteria.

    Science.gov (United States)

    Le Lay, Céline; Coton, Emmanuel; Le Blay, Gwenaëlle; Chobert, Jean-Marc; Haertlé, Thomas; Choiset, Yvan; Van Long, Nicolas Nguyen; Meslet-Cladière, Laurence; Mounier, Jérôme

    2016-12-19

    Fungal growth in bakery products represents the most frequent cause of spoilage and leads to economic losses for industrials and consumers. Bacteria, such as lactic acid bacteria and propionibacteria, are commonly known to play an active role in preservation of fermented food, producing a large range of antifungal metabolites. In a previous study (Le Lay et al., 2016), an extensive screening performed both in vitro and in situ allowed for the selection of bacteria exhibiting an antifungal activity. In the present study, active supernatants against Penicillium corylophilum and Aspergillus niger were analyzed to identify and quantify the antifungal compounds associated with the observed activity. Supernatant treatments (pH neutralization, heating and addition of proteinase K) suggested that organic acids played the most important role in the antifungal activity of each tested supernatant. Different methods (HPLC, mass spectrometry, colorimetric and enzymatic assays) were then applied to analyze the supernatants and it was shown that the main antifungal compounds corresponded to lactic, acetic and propionic acids, ethanol and hydrogen peroxide, as well as other compounds present at low levels such as phenyllactic, hydroxyphenyllactic, azelaic and caproic acids. Based on these results, various combinations of the identified compounds were used to evaluate their effect on conidial germination and fungal growth of P. corylophilum and Eurotium repens. Some combinations presented the same activity than the bacterial culture supernatant thus confirming the involvement of the identified molecules in the antifungal activity. The obtained results suggested that acetic acid was mainly responsible for the antifungal activity against P. corylophilum and played an important role in E. repens inhibition. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Screening and identification of lactic acid bacteria strains with high acid-producing from traditional fermented yak yogurt

    Directory of Open Access Journals (Sweden)

    Chen Xiaoyong

    2017-01-01

    Full Text Available A total of 57 strains of lactic acid bacteria (LAB were isolated and purified from traditional fermented Yak Yogurt in Hongyuan-Sichuan and Yangbajing-Tibet. The strains with high acid-produced were screened by soluble calcium circle and titratable acidity determination. The five strains, 7-1, 22-1, 28-1, 34-1 and 62-1, possessed the high acid-producing and the value of titratable acidity is 196.2, 191.1, 192.2, 194.8 and 200.2 T respectively. Based on 16S rDNA sequence analysis, 22-1 was identified as Lactococcus lactis subsp. lactis, 28-1 as Lactobacillus casei, 34-1 as Lactobacillus fermentium, 7-1 and 62-1 as Enterococcus durans. This study could provide the evidence for researching fermentation strains to improve yogurt quality.

  14. Feed Supplementation with Thermo-Tolerant, Lactic Acid-Producing Bacteria as Probiotics for Swine Husbandry

    International Nuclear Information System (INIS)

    Tongpim, Saowanit; Khammeng, Terdsak; Luanthisong, Pirat; Sakai, Kenji; Piadang, Nattayana

    2006-09-01

    This research work had an objective to employ the thermo tolerant, lactic acid-producing bacteria, Bacillus coagulans strain NF 1 7 as feed additive for swine raising. The bacterial isolate NF 1 7, kept in the culture collection of Khon Kaen University that could tolerate high temperature and produce lactic acid, was employed in this experiment. Cell suspension of isolate NF 1 7 was exposed to gamma irradiation at various doses (1-5 KGy). The isolated 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 L 5 I2 to 14(5), designated as K 1 4 was chosen for further experiments. Isolate K 1 4 together with the parent strain were characterized using morphological, physiological and biochemical tests. They were all identified as Bacillus coagulans. All isolates had optimal growth pH of 6.5 and grew best at 42.50 o C. The strain K 1 4 could tolerate the temperature as high as 59 o C and was then employed in the fermentation of food waste that collected from the university cafeteria. It was found that food waste could support growth of Bacillus K 1 4 and produce about 107 to 108 CFU/g food waste within 1-3 days. Nutritional value of the fermented food waste in the form of protein was also increased. When mixing this selected bacterium as feed additive in daily pig rations, it was found that Bacillus K 1 4 helped increase feed conversion ratio and reduced the mortality in weaned piglets. Experiments were also performed with the growing pigs. It showed that Bacillus Sp. K 1 4 significantly improved the feed conversion ratio

  15. Antibacterial activity and optimisation of bacteriocin producing lactic acid bacteria isolated from beef (red meat) samples

    International Nuclear Information System (INIS)

    Ali, N.M.; Mazhar, B.; Khadija, I.; Kalim, B.

    2016-01-01

    Bacteriocin producing bacteria are commonly found in meat products to enhance their shelf-life. In the present study, bacterial species were isolated from meat samples (beef) from different localities of Lahore, Pakistan. MRS agar medium was used to isolate lactic acid bacteria (LAB) through spread and streak methods (incubated for 72 h at 37 degree C). Identification of bacteriocinogenic LAB strains was done by using staining techniques, morphology based characteristics and biochemical tests. These strains were BSH 1b, BSH 3a, BIP 4a, BIP 3a, BIP 1b and BRR 3a. Antibacterial activity of LAB was performed against food borne pathogens viz., Escherichia coli and Staphylococcus aureus through paper disc diffusion method. Three bacterial strains showed maximum inhibition and characterised by ribotyping viz., BIP 4a was identified as Lactobacillus curvatures, BIP 3a was Staphylococcus warneri and BIP 1b was Lactobacillus graminis . Optimum pH 5-6.5 and 30-37 degree C temperature for isolated bacterial strains was recorded. Protein concentration measured was 0.07 mg/mL for BSH 1b, 0.065 mg/mL for BSH 3a, 0.057 mg/mL for BIP 4a, 0.062 mg/mL for BIP 1b, 0.065 mg/mL for BIP 3a and for BRR 3a 0.078 mg/mL, respectively. Bacteriocin of all isolates except BIP 3a was found to be sensitive towards pepsin and resistant towards Rnase. Bacteriocin production was stable at between pH 5.0 and 6.0 and resistant temperature was 40 degree C. It was concluded that lactic acid bacteria (LAB) from meat can be helpful as antibacterial agents against food-borne bacterial pathogens because of thermostable producing bacteriocin. (author)

  16. Environmental impacts of producing bioethanol and biobased lactic acid from standalone and integrated biorefineries using a consequential and an attributional life cycle assessment approach

    DEFF Research Database (Denmark)

    Parajuli, Ranjan; Knudsen, Marie Trydeman; Birkved, Morten

    2017-01-01

    : a standalone system producing bioethanol from winter wheat-straw (system A), a standalone system producing biobased lactic acid from alfalfa (system B), and an integrated biorefinery system (system C) combining the two standalone systems and producing both bioethanol and lactic acid. The synergy...

  17. Amylolytic Enzymes Acquired from L-Lactic Acid Producing Enterococcus faecium K-1 and Improvement of Direct Lactic Acid Production from Cassava Starch.

    Science.gov (United States)

    Unban, Kridsada; Kanpiengjai, Apinun; Takata, Goro; Uechi, Keiko; Lee, Wen-Chien; Khanongnuch, Chartchai

    2017-09-01

    An amylolytic lactic acid bacterium isolate K-1 was isolated from the wastewater of a cassava starch manufacturing factory and identified as Entercoccus faecium based on 16S rRNA gene sequence analysis. An extracellular α-amylase was purified to homogeneity and the molecular weight of the purified enzyme was approximately 112 kDa with optimal pH value and temperature measured of 7.0 and 40 °C, respectively. It was stable at a pH range of 6.0-7.0, but was markedly sensitive to high temperatures and low pH conditions, even at a pH value of 5. Ba 2+ , Al 3+ , and Co 2+ activated enzyme activity. This bacterium was capable of producing 99.2% high optically pure L-lactic acid of 4.3 and 8.2 g/L under uncontrolled and controlled pH at 6.5 conditions, respectively, in the MRS broth containing 10 g/L cassava starch as the sole carbon source when cultivated at 37 °C for 48 h. A control pH condition of 6.5 improved and stabilized the yield of L-lactic acid production directly from starch even at a high concentration of starch at up to 150 g/L. This paper is the first report describing the properties of purified α-amylase from E. faecium. Additionally, pullulanase and cyclodextrinase activities were also firstly recorded from E. faecium K-1.

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

    Science.gov (United States)

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

    DEFF Research Database (Denmark)

    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...

  20. Antimicrobial and immune modulatory effects of lactic acid and short chain fatty acids produced by vaginal microbiota associated with eubiosis and bacterial vaginosis

    Science.gov (United States)

    Aldunate, Muriel; Srbinovski, Daniela; Hearps, Anna C.; Latham, Catherine F.; Ramsland, Paul A.; Gugasyan, Raffi; Cone, Richard A.; Tachedjian, Gilda

    2015-01-01

    Lactic acid and short chain fatty acids (SCFAs) produced by vaginal microbiota have reported antimicrobial and immune modulatory activities indicating their potential as biomarkers of disease and/or disease susceptibility. In asymptomatic women of reproductive-age the vaginal microbiota is comprised of lactic acid-producing bacteria that are primarily responsible for the production of lactic acid present at ~110 mM and acidifying the vaginal milieu to pH ~3.5. In contrast, bacterial vaginosis (BV), a dysbiosis of the vaginal microbiota, is characterized by decreased lactic acid-producing microbiota and increased diverse anaerobic bacteria accompanied by an elevated pH>4.5. BV is also characterized by a dramatic loss of lactic acid and greater concentrations of mixed SCFAs including acetate, propionate, butyrate, and succinate. Notably women with lactic acid-producing microbiota have more favorable reproductive and sexual health outcomes compared to women with BV. Regarding the latter, BV is associated with increased susceptibility to sexually transmitted infections (STIs) including HIV. In vitro studies demonstrate that lactic acid produced by vaginal microbiota has microbicidal and virucidal activities that may protect against STIs and endogenous opportunistic bacteria as well as immune modulatory properties that require further characterization with regard to their effects on the vaginal mucosa. In contrast, BV-associated SCFAs have far less antimicrobial activity with the potential to contribute to a pro-inflammatory vaginal environment. Here we review the composition of lactic acid and SCFAs in respective states of eubiosis (non-BV) or dysbiosis (BV), their effects on susceptibility to bacterial/viral STIs and whether they have inherent microbicidal/virucidal and immune modulatory properties. We also explore their potential as biomarkers for the presence and/or increased susceptibility to STIs. PMID:26082720

  1. Antimicrobial and immune modulatory effects of lactic acid and short chain fatty acids produced by vaginal microbiota associated with eubiosis and bacterial vaginosis

    Directory of Open Access Journals (Sweden)

    Muriel eAldunate

    2015-06-01

    Full Text Available Lactic acid and short chain fatty acids (SCFAs produced by vaginal microbiota have reported antimicrobial and immune modulatory activities indicating their potential as biomarkers of disease and/or disease susceptibility. In asymptomatic women of reproductive-age the vaginal microbiota is comprised of lactic acid-producing bacteria that are primarily responsible for the production of lactic acid present at ~110 mM and acidifying the vaginal milieu to pH ~3.5. In contrast, bacterial vaginosis (BV, a dysbiosis of the vaginal microbiota, is characterized by decreased lactic acid-producing microbiota and increased diverse anaerobic bacteria accompanied by an elevated pH>4.5. BV is also characterized by a dramatic loss of lactic acid and greater concentrations of mixed SCFAs including acetate, propionate, butyrate and succinate. Notably women with lactic acid-producing microbiota have more favorable reproductive and sexual health outcomes compared to women with BV. Regarding the latter, BV is associated with increased susceptibility to sexually transmitted infections (STIs including HIV. In vitro studies demonstrate that lactic acid produced by vaginal microbiota has microbicidal and virucidal activities that may protect against STIs and endogenous opportunistic bacteria as well as immune modulatory properties that require further characterization with regard to their effects on the vaginal mucosa. In contrast, BV-associated SCFAs have far less antimicrobial activity with the potential to contribute to a pro-inflammatory vaginal environment. Here we review the composition of lactic acid and SCFAs in respective states of eubiosis (non-BV or dysbiosis (BV, their effects on susceptibility to bacterial/viral STIs and whether they have inherent microbicidal/virucidal and immune modulatory properties. We also explore their potential as biomarkers for the presence and/or increased susceptibility to STIs.

  2. Antimicrobial and immune modulatory effects of lactic acid and short chain fatty acids produced by vaginal microbiota associated with eubiosis and bacterial vaginosis.

    Science.gov (United States)

    Aldunate, Muriel; Srbinovski, Daniela; Hearps, Anna C; Latham, Catherine F; Ramsland, Paul A; Gugasyan, Raffi; Cone, Richard A; Tachedjian, Gilda

    2015-01-01

    Lactic acid and short chain fatty acids (SCFAs) produced by vaginal microbiota have reported antimicrobial and immune modulatory activities indicating their potential as biomarkers of disease and/or disease susceptibility. In asymptomatic women of reproductive-age the vaginal microbiota is comprised of lactic acid-producing bacteria that are primarily responsible for the production of lactic acid present at ~110 mM and acidifying the vaginal milieu to pH ~3.5. In contrast, bacterial vaginosis (BV), a dysbiosis of the vaginal microbiota, is characterized by decreased lactic acid-producing microbiota and increased diverse anaerobic bacteria accompanied by an elevated pH>4.5. BV is also characterized by a dramatic loss of lactic acid and greater concentrations of mixed SCFAs including acetate, propionate, butyrate, and succinate. Notably women with lactic acid-producing microbiota have more favorable reproductive and sexual health outcomes compared to women with BV. Regarding the latter, BV is associated with increased susceptibility to sexually transmitted infections (STIs) including HIV. In vitro studies demonstrate that lactic acid produced by vaginal microbiota has microbicidal and virucidal activities that may protect against STIs and endogenous opportunistic bacteria as well as immune modulatory properties that require further characterization with regard to their effects on the vaginal mucosa. In contrast, BV-associated SCFAs have far less antimicrobial activity with the potential to contribute to a pro-inflammatory vaginal environment. Here we review the composition of lactic acid and SCFAs in respective states of eubiosis (non-BV) or dysbiosis (BV), their effects on susceptibility to bacterial/viral STIs and whether they have inherent microbicidal/virucidal and immune modulatory properties. We also explore their potential as biomarkers for the presence and/or increased susceptibility to STIs.

  3. Water Kefir grain as a source of potent dextran producing lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Davidović Slađana Z.

    2015-01-01

    Full Text Available Water kefir is abeverage fermented by a microbial consortium captured in kefir grains. The kefir grains matrix is composed of polysaccharide, primarily dextran, whichis produced by members of the microbial consortium. In this study, we have isolated lactic acid bacteria (LAB from non-commercial water kefir grains (from Belgrade, Serbia and screened for dextran production. Among twelve Lisolates threeproduced slime colonies on modified MRS (mMRS agar containing sucrose instead of glucoseand were presumed to produce dextran. Three LABwere identified based on morphological, physiological and biochemical characteristics and 16S rRNA sequencing as Leuconostoc mesenteroides(strains T1 and T3 and Lactobacillus hilgardii (strain T5. The isolated strains were able to synthesize a substantial amount of dextran in mMRS broth containing 5% sucrose. Maximal yields (11.56, 18.00 and 18.46 g/l were obtained after 16h, 20h and 32h for T1, T3 and T5, respectively. Optimal temperature for dextran production was 23oC for two Leuconostoc mesenteroides strains and 30oC for Lactobacillus hilgardii strain. The produced dextrans were identified based on paper chromatography while the main structure characteristics of purified dextranwere observed by FT-IR spectroscopy. Our study shows that water kefir grains are a natural source of potent dextranproducing LAB. [Projekat Ministarstva nauke Republike Srbije, br. TR 31035

  4. Feed Supplementation with Thermo-Tolerant, Lactic Acid-Producing Bacteria as Probiotics for Swine Husbandry

    Energy Technology Data Exchange (ETDEWEB)

    Tongpim, Saowanit [Dept. of Microbiology, Fac. of Science, Khon Kaen Univ., Khon Kaen (Thailand); Khammeng, Terdsak [Dept. of Animal Science, Fac. of Agriculture, Khon kaen Univ., Khon kaen (Thailand); Luanthisong, Pirat [Rajamangala Univ., of Technology Isan, Karasin Campus, Karasin (Thailand); Sakai, Kenji [Dept. of Agricultural Chemistry, Fac. of Engineering, Oita Univ., Oita (Japan); Piadang, Nattayana [Office of Atoms for Peace, Bangkok (Thailand)

    2006-09-15

    This research work had an objective to employ the thermo tolerant, lactic acid-producing bacteria, Bacillus coagulans strain NF{sub 1}7 as feed additive for swine raising. The bacterial isolate NF{sub 1}7, kept in the culture collection of Khon Kaen University that could tolerate high temperature and produce lactic acid, was employed in this experiment. Cell suspension of isolate NF{sub 1}7 was exposed to gamma irradiation at various doses (1-5 KGy). The isolated survivors were screened on the basis of forming larger colonies and clear zones than the parent strain NF{sub 1}7 when grown on Glucose- Yeast extract-Peptone (GYP) containing CaCO{sub 3}. We obtained 55 effective isolates which the isolate L{sub 5}I2 to 14(5), designated as K{sub 1}4 was chosen for further experiments. Isolate K{sub 1}4 together with the parent strain were characterized using morphological, physiological and biochemical tests. They were all identified as Bacillus coagulans. All isolates had optimal growth pH of 6.5 and grew best at 42.50 {sup o}C. The strain K{sub 1}4 could tolerate the temperature as high as 59 {sup o}C and was then employed in the fermentation of food waste that collected from the university cafeteria. It was found that food waste could support growth of Bacillus K{sub 1}4 and produce about 107 to 108 CFU/g food waste within 1-3 days. Nutritional value of the fermented food waste in the form of protein was also increased. When mixing this selected bacterium as feed additive in daily pig rations, it was found that Bacillus K{sub 1}4 helped increase feed conversion ratio and reduced the mortality in weaned piglets. Experiments were also performed with the growing pigs. It showed that Bacillus Sp. K{sub 1}4 significantly improved the feed conversion ratio

  5. Screening and kinetics of glutaminase and glutamate decarboxylase producing lactic acid bacteria from fermented Thai foods

    Directory of Open Access Journals (Sweden)

    Sasimar Woraharn

    2014-12-01

    Full Text Available L-glutaminase and glutamic acid decarboxylase (GAD catalyzes the hydrolysis of L-glutamine and glutamate, respectively. L-glutaminase widely used in cancer therapy along with a combination of other enzymes and most importantly these enzymes were used in food industries, as a major catalyst of bioconversion. The current investigation was aimed to screen and select L-glutaminase, and GAD producing lactic acid bacteria (LAB. A total of 338 LAB were isolated from fermented meat, fermented fish, fermented soya bean, fermented vegetables and fruits. Among 338 isolates, 22 and 237 LAB has been found to be positive for L-glutaminase and GAD, respectively. We found that 30 days of incubation at 35 ºC and pH 6.0 was the optimum condition for glutaminase activity by G507/1. G254/2 was found to be the best for GAD activity with the optimum condition of pH 6.5, temperature 40 ºC and ten days of incubation. These LAB strains, G507/1 and G254/2, were identified as close relative of Lactobacillus brevis ATCC 14869 and Lactobacillus fermentum NBRC 3956, respectively by 16S rRNA sequencing. Further, improvements in up-stream of the fermentation process with these LAB strains are currently under development.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. Screening and characterization of lactic acid bacterial strains that produce fermented milk and reduce cholesterol levels.

    Science.gov (United States)

    Guan, Xuefang; Xu, Qingxian; Zheng, Yi; Qian, Lei; Lin, Bin

    To screen for and characterize lactic acid bacteria strains with the ability to produce fermented milk and reduce cholesterol levels. The strains were isolated from traditional fermented milk in China. In vitro and in vivo evaluation of cholesterol-reduction were used to identify and verify strains of interest. Characteristics were analyzed using spectrophotometry and plate counting assays. The isolate HLX37 consistently produced fermented milk with strong cholesterol-reducing properties was identified as Lactobacillus plantarum (accession number: KR105940) and was thus selected for further study. The cholesterol reduction by strain HLX37 was 45.84%. The isolates were acid-tolerant at pH 2.5 and bile-tolerant at 0.5% (w/v) in simulated gastric juice (pH 2.5) for 2h and in simulated intestinal fluid (pH 8.0) for 3h. The auto-aggregation rate increased to 87.74% after 24h, while the co-aggregation with Escherichia coli DH5 was 27.76%. Strain HLX37 was intrinsically resistant to antibiotics such as penicillin, tobramycin, kanamycin, streptomycin, vancomycin and amikacin. Compared with rats in the model hyperlipidemia group, the total cholesterol content in the serum and the liver as well as the atherogenic index of rats in the viable fermented milk group significantly decreased by 23.33%, 32.37% and 40.23%, respectively. Fewer fat vacuoles and other lesions in liver tissue were present in both the inactivated and viable fermented milk groups compared to the model group. These studies indicate that strain HLX37 of L. plantarum demonstrates probiotic potential, potential for use as a candidate for commercial use for promoting health. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  8. Screening and characterization of lactic acid bacterial strains that produce fermented milk and reduce cholesterol levels

    Directory of Open Access Journals (Sweden)

    Xuefang Guan

    Full Text Available ABSTRACT Objective To screen for and characterize lactic acid bacteria strains with the ability to produce fermented milk and reduce cholesterol levels. Methods The strains were isolated from traditional fermented milk in China. In vitro and in vivo evaluation of cholesterol-reduction were used to identify and verify strains of interest. Characteristics were analyzed using spectrophotometry and plate counting assays. Results The isolate HLX37 consistently produced fermented milk with strong cholesterol-reducing properties was identified as Lactobacillus plantarum (accession number: KR105940 and was thus selected for further study. The cholesterol reduction by strain HLX37 was 45.84%. The isolates were acid-tolerant at pH 2.5 and bile-tolerant at 0.5% (w/v in simulated gastric juice (pH 2.5 for 2 h and in simulated intestinal fluid (pH 8.0 for 3 h. The auto-aggregation rate increased to 87.74% after 24 h, while the co-aggregation with Escherichia coli DH5 was 27.76%. Strain HLX37 was intrinsically resistant to antibiotics such as penicillin, tobramycin, kanamycin, streptomycin, vancomycin and amikacin. Compared with rats in the model hyperlipidemia group, the total cholesterol content in the serum and the liver as well as the atherogenic index of rats in the viable fermented milk group significantly decreased by 23.33%, 32.37% and 40.23%, respectively. Fewer fat vacuoles and other lesions in liver tissue were present in both the inactivated and viable fermented milk groups compared to the model group. Conclusion These studies indicate that strain HLX37 of L. plantarum demonstrates probiotic potential, potential for use as a candidate for commercial use for promoting health.

  9. Screening for Glucosyltransferase gene (gtf from exopolysaccahride producing lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Donna M. Ariestanti

    2008-04-01

    Full Text Available Glucosyltransferase (GTF is an enzyme involved in exopolysaccharide (EPS polymer synthesis in microbes. One example of EPS that has been used in pharmaceutical and medical application is dextran. Dextran has been used in conjugated-drug delivery system as matrix. As a group of microbes producing EPS, lactic acid bacteria (LAB have been well reported carrying sucrase genes glucosyltransferase (gtf, as well as fructosyltransferases (ftf. In an attempt to search for novel gtf genes as the aim of this study, LAB collection isolated from local sources yielded from previous study were screened performing PCR using degenerate primers DegFor and DegRev. An approximately 660 base pairs (bp amplicons were obtained by using genomic DNAs of those LAB isolates as templates with conserved region of gtf genes catalytic domain as target. Two out of 20 LAB strains were yielded no amplicon as observed on agarose gel, while one strain exhibited non-specific amplicon DNA bands with sizes other than 660 bp. The two negative ones were isolated from soil obtained from dairy product waste field and from waste of soy sauce from previous study, while the latter was isolated from waste of soy sauce.

  10. Microfluidics for producing poly (lactic-co-glycolic acid)-based pharmaceutical nanoparticles.

    Science.gov (United States)

    Li, Xuanyu; Jiang, Xingyu

    2017-12-24

    Microfluidic chips allow the rapid production of a library of nanoparticles (NPs) with distinct properties by changing the precursors and the flow rates, significantly decreasing the time for screening optimal formulation as carriers for drug delivery compared to conventional methods. The batch-to-batch reproducibility which is essential for clinical translation is achieved by precisely controlling the precursors and the flow rate, regardless of operators. Poly (lactic-co-glycolic acid) (PLGA) is the most widely used Food and Drug Administration (FDA)-approved biodegradable polymers. Researchers often combine PLGA with lipids or amphiphilic molecules to assemble into a core/shell structure to exploit the potential of PLGA-based NPs as powerful carriers for cancer-related drug delivery. In this review, we discuss the advantages associated with microfluidic chips for producing PLGA-based functional nanocomplexes for drug delivery. These laboratory-based methods can readily scale up to provide sufficient amount of PLGA-based NPs in microfluidic chips for clinical studies and industrial-scale production. Copyright © 2017. Published by Elsevier B.V.

  11. Purification and characterization of two bacteriocins produced by lactic acid bacteria isolated from Mongolian airag.

    Science.gov (United States)

    Batdorj, B; Dalgalarrondo, M; Choiset, Y; Pedroche, J; Métro, F; Prévost, H; Chobert, J-M; Haertlé, T

    2006-10-01

    The aim of this study was to isolate and identify bacteriocin-producing lactic acid bacteria (LAB) issued from Mongolian airag (traditional fermented mare's milk), and to purify and characterize bacteriocins produced by these LAB. Identification of the bacteria (Enterococcus durans) was carried out on the basis of its morphological, biochemical characteristics and carbohydrate fermentation profile and by API50CH kit and 16S rDNA analyses. The pH-neutral cell-free supernatant of this bacterium inhibited the growth of several Lactobacillus spp. and food-borne pathogens including Escherichia coli, Staphylococcus aureus and Listeria innocua. The antimicrobial agent (enterocin A5-11) was heat stable and was not sensitive to acid and alkaline conditions (pH 2-10), but was sensitive to several proteolytic enzymes. Its inhibitory activity was completely eliminated after treatment with proteinase K and alpha-chymotrypsin. The activity was however not completely inactivated by other proteases including trypsin and pepsin. Three-step purification procedure with high recovery yields was developed to separate two bacteriocins. The applied procedure allowed the recovery of 16% and 64% of enterocins A5-11A and A5-11B, respectively, present in the culture supernatant with purity higher than 99%. SDS-PAGE analyses revealed that enterocin A5-11 has a molecular mass of 5000 Da and mass spectrometry analyses demonstrates molecular masses of 5206 and 5218 Da for fractions A and B, respectively. Amino acid analyses of both enterocins indicated significant quantitative difference in their contents in threonine, alanine, isoleucine and leucine. Their N-termini were blocked hampering straightforward Edman degradation. Bacteriocins A5-11A and B from Ent. durans belong to the class II of bacteriocins. Judging from molecular masses, amino acid composition and spectrum of activities, bacteriocins A5-11A and B from Ent. durans show high degree of similarity with enterocins L50A and L50B

  12. Analysis of microbial community variation during the mixed culture fermentation of agricultural peel wastes to produce lactic acid.

    Science.gov (United States)

    Liang, Shaobo; Gliniewicz, Karol; Gerritsen, Alida T; McDonald, Armando G

    2016-05-01

    Mixed cultures fermentation can be used to convert organic wastes into various chemicals and fuels. This study examined the fermentation performance of four batch reactors fed with different agricultural (orange, banana, and potato (mechanical and steam)) peel wastes using mixed cultures, and monitored the interval variation of reactor microbial communities with 16S rRNA genes using Illumina sequencing. All four reactors produced similar chemical profile with lactic acid (LA) as dominant compound. Acetic acid and ethanol were also observed with small fractions. The Illumina sequencing results revealed the diversity of microbial community decreased during fermentation and a community of largely lactic acid producing bacteria dominated by species of Lactobacillus developed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Complete genome sequence of probiotic Bacillus coagulans HM-08: A potential lactic acid producer.

    Science.gov (United States)

    Yao, Guoqiang; Gao, Pengfei; Zhang, Wenyi

    2016-06-20

    Bacillus coagulans HM-08 is a commercialized probiotic strain in China. Its genome contains a 3.62Mb circular chromosome with an average GC content of 46.3%. In silico analysis revealed the presence of one xyl operon as well as several other genes that are correlated to xylose utilization. The genetic information provided here may help to expand its future biotechnology potential in lactic acid production. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Genome sequence of the thermophilic strain Bacillus coagulans 2-6, an efficient producer of high-optical-purity L-lactic acid.

    Science.gov (United States)

    Su, Fei; Yu, Bo; Sun, Jibin; Ou, Hong-Yu; Zhao, Bo; Wang, Limin; Qin, Jiayang; Tang, Hongzhi; Tao, Fei; Jarek, Michael; Scharfe, Maren; Ma, Cuiqing; Ma, Yanhe; Xu, Ping

    2011-09-01

    Bacillus coagulans 2-6 is an efficient producer of lactic acid. The genome of B. coagulans 2-6 has the smallest genome among the members of the genus Bacillus known to date. The frameshift mutation at the start of the d-lactate dehydrogenase sequence might be responsible for the production of high-optical-purity l-lactic acid.

  15. Bacillus spp. produce antibacterial activities against lactic acid bacteria that contaminate fuel ethanol plants.

    Science.gov (United States)

    Manitchotpisit, Pennapa; Bischoff, Kenneth M; Price, Neil P J; Leathers, Timothy D

    2013-05-01

    Lactic acid bacteria (LAB) frequently contaminate commercial fuel ethanol fermentations, reducing yields and decreasing profitability of biofuel production. Microorganisms from environmental sources in different geographic regions of Thailand were tested for antibacterial activity against LAB. Four bacterial strains, designated as ALT3A, ALT3B, ALT17, and MR1, produced inhibitory effects on growth of LAB. Sequencing of rRNA identified these strains as species of Bacillus subtilis (ALT3A and ALT3B) and B. cereus (ALT17 and MR1). Cell mass from colonies and agar samples from inhibition zones were analyzed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry. The spectra of ALT3A and ALT3B showed a strong signal at m/z 1,060, similar in mass to the surfactin family of antimicrobial lipopeptides. ALT3A and ALT3B were analyzed by zymogram analysis using SDS-PAGE gels placed on agar plates inoculated with LAB. Cell lysates possessed an inhibitory protein of less than 10 kDa, consistent with the production of an antibacterial lipopeptide. Mass spectra of ALT17 and MR1 had notable signals at m/z 908 and 930 in the whole cell extracts and at m/z 687 in agar, but these masses do not correlate with those of previously reported antibacterial lipopeptides, and no antibacterial activity was detected by zymogram. The antibacterial activities produced by these strains may have application in the fuel ethanol industry as an alternative to antibiotics for prevention and control of bacterial contamination.

  16. Medical and Personal Care Applications of Bacteriocins Produced by Lactic Acid Bacteria

    Science.gov (United States)

    Dicks, L. M. T.; Heunis, T. D. J.; van Staden, D. A.; Brand, A.; Noll, K. Sutyak; Chikindas, M. L.

    The frequent use of antibiotics has led to a crisis in the antibiotic ­resistance of pathogens associated with humans and animals. Antibiotic resistance and the emergence of multiresistant bacterial pathogens have led to the investigation of alternative antimicrobial agents to treat and prevent infections in both humans and animals. Research on antimicrobial peptides, with a special interest on bacteriocins of lactic acid bacteria, is entering a new era with novel applications other than food preservation. Many scientists are now focusing on the application of these peptides in medicinal and personal care products. However, it is difficult to assess the success of such ventures due to the dearth of information that has been published and the lack of clinical trials.

  17. Lactic acid and lactates

    NARCIS (Netherlands)

    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. Technological properties of bacteriocin-producing lactic acid bacteria isolated from Pico cheese an artisanal cow's milk cheese.

    Science.gov (United States)

    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.

  19. Novel Method of Lactic Acid Production by Electrodialysis Fermentation

    OpenAIRE

    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...

  20. Biotechnological Production of Lactic Acid and Its Recent Applications

    Directory of Open Access Journals (Sweden)

    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.

  1. Use of superoxide dismutase and catalase producing lactic acid bacteria in TNBS induced Crohn's disease in mice.

    Science.gov (United States)

    LeBlanc, Jean Guy; del Carmen, Silvina; Miyoshi, Anderson; Azevedo, Vasco; Sesma, Fernando; Langella, Philippe; Bermúdez-Humarán, Luis G; Watterlot, Laurie; Perdigon, Gabriela; de Moreno de LeBlanc, Alejandra

    2011-02-10

    Reactive oxygen species are involved in various aspects of intestinal inflammation and tumor development. Decreasing their levels using antioxidant enzymes, such as catalase (CAT) or superoxide dismutase (SOD) could therefore be useful in the prevention of certain diseases. Lactic acid bacteria (LAB) are ideal candidates to deliver these enzymes in the gut. In this study, the anti-inflammatory effects of CAT or SOD producing LAB were evaluated using a trinitrobenzenesulfonic acid (TNBS) induced Crohn's disease murine model. Engineered Lactobacillus casei BL23 strains producing either CAT or SOD, or the native strain were given to mice before and after intrarectal administration of TNBS. Animal survival, live weight, intestinal morphology and histology, enzymatic activities, microbial translocation to the liver and cytokines released in the intestinal fluid were evaluated. The mice that received CAT or SOD-producing LAB showed a faster recovery of initial weight loss, increased enzymatic activities in the gut and lesser extent of intestinal inflammation compared to animals that received the wild-type strain or those that did not receive bacterial supplementation. Our findings suggest that genetically engineered LAB that produce antioxidant enzymes could be used to prevent or decrease the severity of certain intestinal pathologies. Copyright © 2010 Elsevier B.V. All rights reserved.

  2. Lactic Acid Bacteria Producing Inhibitor of Alpha Glucosidase Isolated from Ganyong (Canna Edulis) and Kimpul (Xanthosoma sagittifolium)

    Science.gov (United States)

    Nurhayati, Rifa; Miftakhussolikhah; Frediansyah, Andri; Lailatul Rachmah, Desy

    2017-12-01

    Type 2 diabetes is a disease that caused by the failure of insulin secretion by the beta cells of the pancreas and insulin resistance in peripheral levels. One therapy for diabetics is by inhibiting the activity of α-glucosidase. Lactic acid bacteria have the ability to inhibit of α-glucosidase activity. The aims of this research was to isolation and screening of lactic acid bacteria from ganyong tuber (Canna Edulis) and kimpul tuber (Xanthosoma sagittifolium), which has the ability to inhibit the activity of α-glucosidase. Eightteen isolates were identified as lactic acid bacteria and all of them could inhibit the activity of α-glukosidase. The GN 8 isolate was perform the highest inhibition acivity.

  3. Application of Baechu-Kimchi Powder and GABA-Producing Lactic Acid Bacteria for the Production of Functional Fermented Sausages

    Science.gov (United States)

    Choi, Ji Hun; Kang, Ki Moon

    2017-01-01

    This study was carried out to determine the physicochemical, microbiological, and quality characteristics of a new type of fermented sausage manufactured by incorporating Baechu-kimchi powder and gamma-aminobutyric acid (GABA)-producing lactic acid bacteria (LAB). The LAB count was at the maximum level by day nine of ripening in inoculated sausages, accompanied by a rapid decrease in the pH. The addition of kimchi powder decreased the lightness (L*) and increased the redness (a*) and, yellowness (b*) values, while also significantly increasing the hardness and chewiness of the sausage (p<0.05). Moreover, although the thiobarbituric acid reactive substances values increased in all samples during the study period, this increase was lower in the kimchi-treated samples, indicating a reduction in lipid oxidation. Overall, our results show that the addition of Baechu-kimchi powder to sausages reduced the off-flavor properties and improved the taste profile of the fermented sausage in sensory evaluations. The GABA content of all fermented sausages increased from 17.42-25.14 mg/kg on the third day of fermentation to 60.95-61.47 mg/kg on the thirtieth day. These results demonstrate that Baechu-kimchi powder and GABA-producing LAB could be functional materials in fermented sausage to improve quality characteristics. PMID:29725201

  4. Potential of bacteriocin-producing lactic acid bacteria for safety improvements of traditional Thai fermented meat and human health.

    Science.gov (United States)

    Swetwiwathana, Adisorn; Visessanguan, Wonnop

    2015-11-01

    Lactic acid bacteria (LAB) are very important in converting of agricultural products into safe, delicious and shelf stable foods for human consumption. The preservative activity of LAB in foods is mainly attributed to the production of anti-microbial metabolites such as organic acids and bacteriocins which enables them to grow and control the growth of pathogens and spoilage microorganisms. Besides ensuring safety, bacteriocin-producing LAB with their probiotic potentials could also be emerging as a means to develop functional meat products with desirable health benefits. Nevertheless, to be qualified as a candidate probiotic culture, other prerequisite probiotic properties of bacteriocin-producing LAB have to be assessed according to regulatory guidelines for probiotics. Nham is an indigenous fermented sausage of Thailand that has gained popularity and acceptance among Thais. Since Nham is made from raw meat and is usually consumed without cooking, risks due to undesirable microorganisms such as Salmonella spp., Staphylococcus aureus, and Listeria monocytogenes, are frequently observed. With an ultimate goal to produce safer and healthier product, our research attempts on the development of a variety of new Nham products are discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. 10-oxo-12(Z)-octadecenoic acid, a linoleic acid metabolite produced by gut lactic acid bacteria, potently activates PPARγ and stimulates adipogenesis.

    Science.gov (United States)

    Goto, Tsuyoshi; Kim, Young-Il; Furuzono, Tomoya; Takahashi, Nobuyuki; Yamakuni, Kanae; Yang, Ha-Eun; Li, Yongjia; Ohue, Ryuji; Nomura, Wataru; Sugawara, Tatsuya; Yu, Rina; Kitamura, Nahoko; Park, Si-Bum; Kishino, Shigenobu; Ogawa, Jun; Kawada, Teruo

    2015-04-17

    Our previous study has shown that gut lactic acid bacteria generate various kinds of fatty acids from polyunsaturated fatty acids such as linoleic acid (LA). In this study, we investigated the effects of LA and LA-derived fatty acids on the activation of peroxisome proliferator-activated receptors (PPARs) which regulate whole-body energy metabolism. None of the fatty acids activated PPARδ, whereas almost all activated PPARα in luciferase assays. Two fatty acids potently activated PPARγ, a master regulator of adipocyte differentiation, with 10-oxo-12(Z)-octadecenoic acid (KetoA) having the most potency. In 3T3-L1 cells, KetoA induced adipocyte differentiation via the activation of PPARγ, and increased adiponectin production and insulin-stimulated glucose uptake. These findings suggest that fatty acids, including KetoA, generated in gut by lactic acid bacteria may be involved in the regulation of host energy metabolism. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Inhibitory effect of bacteriocin-producing lactic acid bacteria against histamine-forming bacteria isolated from Myeolchi-jeot

    Directory of Open Access Journals (Sweden)

    Eun-Seo Lim

    2016-12-01

    Full Text Available Abstract The objectives of this study were to identify the histamine-forming bacteria and bacteriocin- producing lactic acid bacteria (LAB isolated from Myeolchi-jeot according to sequence analysis of the 16S rRNA gene, to evaluate the inhibitory effects of the bacteriocin on the growth and histamine accumulation of histamine-forming bacteria, and to assess the physico-chemical properties of the bacteriocin. Based on 16S rRNA gene sequences, histamine-forming bacteria were identified as Bacillus licheniformis MCH01, Serratia marcescens MCH02, Staphylococcus xylosus MCH03, Aeromonas hydrophila MCH04, and Morganella morganii MCH05. The five LAB strains identified as Pediococcus acidilactici MCL11, Leuconostoc mesenteroides MCL12, Enterococcus faecium MCL13, Lactobacillus sakei MCL14, and Lactobacillus acidophilus MCL15 were found to produce an antibacterial compound with inhibitory activity against the tested histamine-producing bacteria. The inhibitory activity of these bacteriocins obtained from the five LAB remained stable after incubation at pH 4.0–8.0 and heating for 10 min at 80 °C; however, the bacteriocin activity was destroyed after treatment with papain, pepsin, proteinase K, α-chymotrypsin, or trypsin. Meanwhile, these bacteriocins produced by the tested LAB strains also exhibited histamine-degradation ability. Therefore, these antimicrobial substances may play a role in inhibiting histamine formation in the fermented fish products and preventing seafood-related food-borne disease caused by bacterially generated histamine.

  7. Functionality of exopolysaccharides produced by lactic acid bacteria in an in vitro gastric system.

    Science.gov (United States)

    Mozzi, F; Gerbino, E; Font de Valdez, G; Torino, M I

    2009-07-01

    To evaluate whether slime-exopolysaccharides (EPS) or capsular-polysaccharide (CPS) production could protect the polymer-producing strains Streptococcus thermophilus CRL 1190 and Lactobacillus casei CRL 87 against the harsh conditions of an in vitro gastric system (GS). EPS stability on the GS was studied. An in vitro GS model containing human saliva and gastric juice was standardized. Polymer functionality on the cell viability and metabolic activity of the EPS-producing strains in the GS acidic conditions was evaluated. Two isogenic EPS/CPS deficient mutants were used for comparison. EPS or CPS conferred no significant protection on the cell viability of the studied strains after passage through the GS conditions. However, the phospho- and beta-galactosidase activities of the EPS(+) strains were higher than those of the EPS(-). Cytoplasmic alterations in the wild-type and mutant strains and partial degradation of both EPS were detected. The presence of EPS/CPS protected the metabolic activity of the assayed LAB strains, but had no effect on survival at low pH. The presence of EPS/CPS as well as polymer resistance to the harsh conditions of the human GS could impact positively in probiotic strains to exert their properties in the host.

  8. Quantitative and qualitative determination of CLA produced by bifidobacterium and lactic acid bacteria by combining spectrophotometric and Ag+-HPLC techniques

    OpenAIRE

    Rodríguez-Alcalá, Luis M.; Braga, Teresa; Malcata, F. Xavier; Gomes, Ana; Fontecha, Javier

    2011-01-01

    Bifidobacterium and lactic acid bacteria (LAB), especially from the genera Lactobacillus and Lactococcus, are commonly used in the production of fermented dairy products due to their potential probiotic characteristics. Moreover, some strains of these microorganisms also have the ability to produce conjugated linoleic acid (CLA) from linoleic acid (LA), which has attracted much attention as a novel type of beneficial functional fermented milk. In the present work 22 probiotic bact...

  9. 10-oxo-12(Z)-octadecenoic acid, a linoleic acid metabolite produced by gut lactic acid bacteria, potently activates PPARγ and stimulates adipogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Goto, Tsuyoshi, E-mail: tgoto@kais.kyoto-u.ac.jp [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011 (Japan); Research Unit for Physiological Chemistry, The Center for the Promotion of Interdisciplinary Education and Research, Kyoto University (Japan); Kim, Young-Il; Furuzono, Tomoya [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011 (Japan); Takahashi, Nobuyuki [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011 (Japan); Research Unit for Physiological Chemistry, The Center for the Promotion of Interdisciplinary Education and Research, Kyoto University (Japan); Yamakuni, Kanae; Yang, Ha-Eun; Li, Yongjia [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011 (Japan); Ohue, Ryuji [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011 (Japan); Research Unit for Physiological Chemistry, The Center for the Promotion of Interdisciplinary Education and Research, Kyoto University (Japan); Nomura, Wataru [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011 (Japan); Sugawara, Tatsuya [Laboratory of Marine Bioproducts Technology, Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502 (Japan); Yu, Rina [Department of Food Science and Nutrition, University of Ulsan, Ulsan 680-749 (Korea, Republic of); Kitamura, Nahoko [Laboratory of Fermentation Physiology and Applied Microbiology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502 (Japan); and others

    2015-04-17

    Our previous study has shown that gut lactic acid bacteria generate various kinds of fatty acids from polyunsaturated fatty acids such as linoleic acid (LA). In this study, we investigated the effects of LA and LA-derived fatty acids on the activation of peroxisome proliferator-activated receptors (PPARs) which regulate whole-body energy metabolism. None of the fatty acids activated PPARδ, whereas almost all activated PPARα in luciferase assays. Two fatty acids potently activated PPARγ, a master regulator of adipocyte differentiation, with 10-oxo-12(Z)-octadecenoic acid (KetoA) having the most potency. In 3T3-L1 cells, KetoA induced adipocyte differentiation via the activation of PPARγ, and increased adiponectin production and insulin-stimulated glucose uptake. These findings suggest that fatty acids, including KetoA, generated in gut by lactic acid bacteria may be involved in the regulation of host energy metabolism. - Highlights: • Most LA-derived fatty acids from gut lactic acid bacteria potently activated PPARα. • Among tested fatty acids, KetoA and KetoC significantly activated PPARγ. • KetoA induced adipocyte differentiation via the activation of PPARγ. • KetoA enhanced adiponectin production and glucose uptake during adipogenesis.

  10. 10-oxo-12(Z)-octadecenoic acid, a linoleic acid metabolite produced by gut lactic acid bacteria, potently activates PPARγ and stimulates adipogenesis

    International Nuclear Information System (INIS)

    Goto, Tsuyoshi; Kim, Young-Il; Furuzono, Tomoya; Takahashi, Nobuyuki; Yamakuni, Kanae; Yang, Ha-Eun; Li, Yongjia; Ohue, Ryuji; Nomura, Wataru; Sugawara, Tatsuya; Yu, Rina; Kitamura, Nahoko

    2015-01-01

    Our previous study has shown that gut lactic acid bacteria generate various kinds of fatty acids from polyunsaturated fatty acids such as linoleic acid (LA). In this study, we investigated the effects of LA and LA-derived fatty acids on the activation of peroxisome proliferator-activated receptors (PPARs) which regulate whole-body energy metabolism. None of the fatty acids activated PPARδ, whereas almost all activated PPARα in luciferase assays. Two fatty acids potently activated PPARγ, a master regulator of adipocyte differentiation, with 10-oxo-12(Z)-octadecenoic acid (KetoA) having the most potency. In 3T3-L1 cells, KetoA induced adipocyte differentiation via the activation of PPARγ, and increased adiponectin production and insulin-stimulated glucose uptake. These findings suggest that fatty acids, including KetoA, generated in gut by lactic acid bacteria may be involved in the regulation of host energy metabolism. - Highlights: • Most LA-derived fatty acids from gut lactic acid bacteria potently activated PPARα. • Among tested fatty acids, KetoA and KetoC significantly activated PPARγ. • KetoA induced adipocyte differentiation via the activation of PPARγ. • KetoA enhanced adiponectin production and glucose uptake during adipogenesis

  11. Promoter sequence of 3-phosphoglycerate kinase gene 1 of lactic acid-producing fungus rhizopus oryzae and a method of expressing a gene of interest in fungal species

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Johnway [Richland, WA; Skeen, Rodney S [Pendleton, OR

    2002-10-15

    The present invention provides the promoter clone discovery of phosphoglycerate kinase gene 1 of a lactic acid-producing filamentous fungal strain, Rhizopus oryzae. The isolated promoter can constitutively regulate gene expression under various carbohydrate conditions. In addition, the present invention also provides a design of an integration vector for the transformation of a foreign gene in Rhizopus oryzae.

  12. Promoter sequence of 3-phosphoglycerate kinase gene 2 of lactic acid-producing fungus rhizopus oryzae and a method of expressing a gene of interest in fungal species

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Johnway [Richland, WA; Skeen, Rodney S [Pendleton, OR

    2003-03-04

    The present invention provides the promoter clone discovery of phosphoglycerate kinase gene 2 of a lactic acid-producing filamentous fungal strain, Rhizopus oryzae. The isolated promoter can constitutively regulate gene expression under various carbohydrate conditions. In addition, the present invention also provides a design of an integration vector for the transformation of a foreign gene in Rhizopus oryzae.

  13. In vitro evaluation of bacteriocin-like inhibitory substances produced by lactic acid bacteria isolated during traditional Sicilian cheese making

    Directory of Open Access Journals (Sweden)

    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.

  14. Lactic acid-producing yeast cells having nonfunctional L- or D-lactate:ferricytochrome C oxidoreductase cells

    Science.gov (United States)

    Miller, Matthew [Boston, MA; Suominen, Pirkko [Maple Grove, MN; Aristidou, Aristos [Highland Ranch, CO; Hause, Benjamin Matthew [Currie, MN; Van Hoek, Pim [Camarillo, CA; Dundon, Catherine Asleson [Minneapolis, MN

    2012-03-20

    Yeast cells having an exogenous lactate dehydrogenase gene ae modified by reducing L- or D-lactate:ferricytochrome c oxidoreductase activity in the cell. This leads to reduced consumption of lactate by the cell and can increase overall lactate yields in a fermentation process. Cells having the reduced L- or D-lactate:ferricytochrome c oxidoreductase activity can be screened for by resistance to organic acids such as lactic or glycolic acid.

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

  17. The use of lactic acid-producing, malic acid-producing, or malic acid-degrading yeast strains for acidity adjustment in the wine industry.

    Science.gov (United States)

    Su, Jing; Wang, Tao; Wang, Yun; Li, Ying-Ying; Li, Hua

    2014-03-01

    In an era of economic globalization, the competition among wine businesses is likely to get tougher. Biotechnological innovation permeates the entire world and intensifies the severity of the competition of the wine industry. Moreover, modern consumers preferred individualized, tailored, and healthy and top quality wine products. Consequently, these two facts induce large gaps between wine production and wine consumption. Market-orientated yeast strains are presently being selected or developed for enhancing the core competitiveness of wine enterprises. Reasonable biological acidity is critical to warrant a high-quality wine. Many wild-type acidity adjustment yeast strains have been selected all over the world. Moreover, mutation breeding, metabolic engineering, genetic engineering, and protoplast fusion methods are used to construct new acidity adjustment yeast strains to meet the demands of the market. In this paper, strategies and concepts for strain selection or improvement methods were discussed, and many examples based upon selected studies involving acidity adjustment yeast strains were reviewed. Furthermore, the development of acidity adjustment yeast strains with minimized resource inputs, improved fermentation, and enological capabilities for an environmentally friendly production of healthy, top quality wine is presented.

  18. A rapid HPEAC method for determination of lactic acid produced by ...

    African Journals Online (AJOL)

    Poste

    water bath at 65°C from 3 to 4 min. The fat content (in percent) ... were compared to the EMBL, Gen Bank, DDJB and PDB databases, using BLAST ..... Structure of the exopolysaccharide produced by Lactococcus lactis subsp cremoris H414 ...

  19. Gas release-based prescreening combined with reversed-phase HPLC quantitation for efficient selection of high-γ-aminobutyric acid (GABA)-producing lactic acid bacteria.

    Science.gov (United States)

    Wu, Qinglong; Shah, Nagendra P

    2015-02-01

    High γ-aminobutyric acid (GABA)-producing lactobacilli are promising for the manufacture of GABA-rich foods and to synthesize GRAS (generally recognized as safe)-grade GABA. However, common chromatography-based screening is time-consuming and inefficient. In the present study, Korean kimchi was used as a model of lactic acid-based fermented foods, and a gas release-based prescreening of potential GABA producers was developed. The ability to produce GABA by potential GABA producers in de Man, Rogosa, and Sharpe medium supplemented with or without monosodium glutamate was further determined by HPLC. Based on the results, 9 isolates were regarded as high GABA producers, and were further genetically identified as Lactobacillus brevis based on the sequences of 16S rRNA gene. Gas release-based prescreening combined with reversed-phase HPLC confirmation was an efficient and cost-effective method to identify high-GABA-producing LAB, which could be good candidates for probiotics. The GABA that is naturally produced by these high-GABA-producing LAB could be used as a food additive. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  20. Preliminary characterization of wild lactic acid bacteria and their abilities to produce flavour compounds in ripened model cheese system.

    Science.gov (United States)

    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.

  1. Enhancement productivity of lactic acid bacteria (LAB) to produced ex polysaccharide

    International Nuclear Information System (INIS)

    EL-Fouly, M.; Meleigy, S.A; Hendawy, W.S.; Magdoub, M.I.N.; Aita, O.A.

    2010-01-01

    Isolation and characterization of exo cellular polysaccharide was studied in order to evaluate some parameters in the synthesis of exo polysaccharide (EPS) and improve their production through submerged fermentation processes. Isolation strains Lactobacillus delbrueckii ssp bulgaricus (IS1), Lactococcus lactis ssp cremoris (IS2) and Lactobacillus delbrueckii ssp bulgaricus (IS3) were studied in shake flasks using yeast extract, surfactants and different exposure doses of gamma irradiation. The optimum concentration of (EPS) formation (0.762 g/l) by Lactococcus lactis ssp cremoris (IS2) at and 3.0(g/l) yeast extract, 1.72 (g/l) at 0.5 (%) surfactant Triton X-100. Also, EPS (1.842 g/l) was produced when Lactococcus lactis ssp cremoris (IS2) exposed to 0.2 kGy dose level

  2. Isolation and Characterization of Lactic Acid Bacteria (LAB) Produced Exo cellular Polysaccharide

    International Nuclear Information System (INIS)

    Meleigy, S.A.; Hendawy, W.S.

    2009-01-01

    Isolation and characterization of exo cellular polysaccharide was studied in order to evaluate some parameters in the synthesis of exo polysaccharide (EPS) and improve their production through submerged fermentation processes. Isolation strains Lactobacillus delbrueckii ssp bulgaricus (IS 1 ), Lactococcus lactis ssp cremoris (IS 2 ) and Lactobacillus delbrueckii ssp bulgaricus (IS 3 ) were studied in shake flasks using yeast extract, surfactants and different exposure doses of gamma irradiation.The optimum concentration of (EPS) formation (0.762 g/l) by Lactococcus lactis ssp cremoris (IS 2 ), 3.0 (g/l) yeast extract, 1.72 (g/l) at 0.5 (%) surfactant Triton X-100. Also, EPS (1.842 g/l) was produced when Lactococcus lactis ssp cremoris (IS 2 ) exposed to 0.2 kGy dose level.

  3. [Teichoic acids from lactic acid bacteria].

    Science.gov (United States)

    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.

  4. Antioxidant activity of pea protein hydrolysates produced by batch fermentation with lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Stanisavljević Nemanja S.

    2015-01-01

    Full Text Available Nine Lactobacillus strains known for surface proteinase activity were chosen from our collection and tested for their ability to grow in pea seed protein-based medium, and to hydrolyze purified pea proteins in order to produce peptides with antioxidant (AO activity. Two strains, Lactobacillus rhamnosus BGT10 and Lactobacillus zeae LMG17315, exhibited strong proteolytic activity against pea proteins. The AO activity of the pea hydrolysate fraction, MW <10 kDa, obtained by the fermentation of purified pea proteins with Lactobacillus rhamnosus BGT10, was tested by standard spectrophotometric assays (DPPH, ABTS, Fe3+-reducing capacity and the recently developed direct current (DC polarographic assay. The low molecular weight fraction of the obtained hydrolysate was separated using ion exchange chromatography, while the AO activity of eluted fractions was determined by means of a sensitive DC polarographic assay without previous concentration of samples. Results revealed that the fraction present in low abundance that contained basic peptides possessed the highest antioxidant activity. Based on the obtained results, it can be concluded that Lactobacillus rhamnosus BGT10 should be further investigated as a candidate strain for large-scale production of bioactive peptides from legume proteins. [Projekat Ministartsva nauke Republike Srbije, br. 173005 i br. 173026

  5. Genetics of Lactic Acid Bacteria

    Science.gov (United States)

    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).

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

    Directory of Open Access Journals (Sweden)

    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.

  7. Comparative genomics of the lactic acid bacteria

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. Electron transport chains of lactic acid bacteria

    NARCIS (Netherlands)

    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.

    Science.gov (United States)

    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.

    Science.gov (United States)

    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. Enhanced Inulin Saccharification by Self-Produced Inulinase from a Newly Isolated Penicillium sp. and its Application in D-Lactic Acid Production.

    Science.gov (United States)

    Zheng, Zhaojuan; Xu, Qianqian; Liu, Peng; Zhou, Fan; Ouyang, Jia

    2018-03-10

    In order to find an alternative for commercial inulinase, a strain XL01 identified as Penicillium sp. was screened for inulinase production. The broth after cultivated was centrifuged, filtered, and used as crude enzyme for the following saccharification. At pH 5.0 and 50 °C, the crude enzyme released 84.9 g/L fructose and 20.7 g/L glucose from 120 g/L inulin in 72 h. In addition, simultaneous saccharification and fermentation of chicory flour for D-lactic acid production was carried out using the self-produced crude inulinase and Lactobacillus bulgaricus CGMCC 1.6970. A high D-lactic acid titer and productivity of 122.0 g/L and 1.69 g/(L h) was achieved from 120 g/L chicory flour in 72 h. The simplicity for inulinase production and the high efficiency for D-lactic acid fermentation provide a perspective and profitable industrial biotechnology for utilization of the inulin-rich biomass.

  12. Selected lactic acid-producing bacterial isolates with the capacity to reduce Salmonella translocation and virulence gene expression in chickens.

    Directory of Open Access Journals (Sweden)

    Xiaojian Yang

    Full Text Available BACKGROUND: Probiotics have been used to control Salmonella colonization/infection in chickens. Yet the mechanisms of probiotic effects are not fully understood. This study has characterized our previously-selected lactic acid-producing bacterial (LAB isolates for controlling Salmonella infection in chickens, particularly the mechanism underlying the control. METHODOLOGY/PRINCIPAL FINDINGS: In vitro studies were conducted to characterize 14 LAB isolates for their tolerance to low pH (2.0 and high bile salt (0.3-1.5% and susceptibility to antibiotics. Three chicken infection trials were subsequently carried out to evaluate four of the isolates for reducing the burden of Salmonella enterica serovar Typhimurium in the broiler cecum. Chicks were gavaged with LAB cultures (10(6-7 CFU/chick or phosphate-buffered saline (PBS at 1 day of age followed by Salmonella challenge (10(4 CFU/chick next day. Samples of cecal digesta, spleen, and liver were examined for Salmonella counts on days 1, 3, or 4 post-challenge. Salmonella in the cecum from Trial 3 was also assessed for the expression of ten virulence genes located in its pathogenicity island-1 (SPI-1. These genes play a role in Salmonella intestinal invasion. Tested LAB isolates (individuals or mixed cultures were unable to lower Salmonella burden in the chicken cecum, but able to attenuate Salmonella infection in the spleen and liver. The LAB treatments also reduced almost all SPI-1 virulence gene expression (9 out of 10 in the chicken cecum, particularly at the low dose. In vitro treatment with the extracellular culture fluid from a LAB culture also down-regulated most SPI-1 virulence gene expression. CONCLUSIONS/SIGNIFICANCE: The possible correlation between attenuation of Salmonella infection in the chicken spleen and liver and reduction of Salmonella SPI-1 virulence gene expression in the chicken cecum by LAB isolates is a new observation. Suppression of Salmonella virulence gene expression in

  13. Effect of phosphate-based glass fibre surface properties on thermally produced poly(lactic acid) matrix composites.

    Science.gov (United States)

    Mohammadi, Maziar Shah; Ahmed, Ifty; Muja, Naser; Rudd, Christopher D; Bureau, Martin N; Nazhat, Showan N

    2011-12-01

    Incorporation of soluble bioactive glass fibres into biodegradable polymers is an interesting approach for bone repair and regeneration. However, the glass composition and its surface properties significantly affect the nature of the fibre-matrix interface and composite properties. Herein, the effect of Si and Fe on the surface properties of calcium containing phosphate based glasses (PGs) in the system (50P(2)O(5)-40CaO-(10-x)SiO(2)-xFe(2)O(3), where x = 0, 5 and 10 mol.%) were investigated. Contact angle measurements revealed a higher surface energy, and surface polarity as well as increased hydrophilicity for Si doped PG which may account for the presence of surface hydroxyl groups. Two PG formulations, 50P(2)O(5)-40CaO-10Fe(2)O(3) (Fe10) and 50P(2)O(5)-40CaO-5Fe(2)O(3)-5SiO(2) (Fe5Si5), were melt drawn into fibres and randomly incorporated into poly(lactic acid) (PLA) produced by melt processing. The ageing in deionised water (DW), mechanical property changes in phosphate buffered saline (PBS) and cytocompatibility properties of these composites were investigated. In contrast to Fe10 and as a consequence of the higher surface energy and polarity of Fe5Si5, its incorporation into PLA led to increased inorganic/organic interaction indicated by a reduction in the carbonyl group of the matrix. PLA chain scission was confirmed by a greater reduction in its molecular weight in PLA-Fe5Si5 composites. In DW, the dissolution rate of PLA-Fe5Si5 was significantly higher than that of PLA-Fe10. Dissolution of the glass fibres resulted in the formation of channels within the matrix. Initial flexural strength was significantly increased through PGF incorporation. After PBS ageing, the reduction in mechanical properties was greater for PLA-Fe5Si5 compared to PLA-Fe10. MC3T3-E1 preosteoblasts seeded onto PG discs, PLA and PLA-PGF composites were evaluated for up to 7 days indicating that the materials were generally cytocompatible. In addition, cell alignment along the PGF

  14. Biodegradable poly(lactic acid)

    Indian Academy of Sciences (India)

    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 ...

  15. Effects of the organic acids produced by a lactic acid bacterium in Apis mellifera colony development, Nosema ceranae control and fumagillin efficiency.

    Science.gov (United States)

    Maggi, Matías; Negri, Pedro; Plischuk, Santiago; Szawarski, Nicolás; De Piano, Fiorella; De Feudis, Leonardo; Eguaras, Martín; Audisio, Carina

    2013-12-27

    The European honey bee Apis mellifera is known to be affected by many parasites and pathogens that have great impact over the insect development. Among parasites affecting bee health, Nosema ceranae is one of the main biotic factors affecting colony populations. As honey bee populations decline, interest in pathogenic and mutualistic relationships between bees and microorganisms has increased. The main goal of the current study was to assess the effect of the oral administration of the metabolites produced by Lactobacillus johnsonii CRL1647 (mainly organic acids) supplemented in syrup, on: (I) N. ceranae sporulation dynamics before and after fumagillin application, and (II) performance of A. mellifera colonies. Different experiments were conducted to evaluate the effects of these bacterial metabolites on bees: in vitro administration revealed no toxic effects against bees. Colonies fed with the lactic acids incremented their beehive population and also the amount of fat bodies per bee. Finally, the organic acids reduced the intensity of the pathogen after the second application of treatment as well as enhanced the fumagillin efficiency. This study provides important information for the development of new control substances against nosemosis. Copyright © 2013 Elsevier B.V. All rights reserved.

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

    African Journals Online (AJOL)

    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. The Impact of the Antimicrobial Compounds Produced by Lactic Acid Bacteria on the Growth Performance of Mycobacterium avium subsp. paratuberculosis

    Directory of Open Access Journals (Sweden)

    Petr Kralik

    2018-04-01

    Full Text Available Cell-free supernatants (CFSs extracted from various lactic acid bacteria (LAB cultures were applied to Mycobacterium avium subsp. paratuberculosis (MAP cells to determine their effect on MAP viability. In addition, 5% lactic acid (LA; pH 3 and commercially synthetized nisin bacteriocin were also tested. This procedure was chosen in order to mimic the influence of LAB compounds during the production and storage of fermented milk products, which can be contaminated by MAP. Its presence in milk and milk products is of public concern due to the possible ingestion of MAP by consumers and the discussed role of MAP in Crohn’s disease. Propidium monoazide real-time PCR (PMA qPCR was used for viability determination. Although all CFS showed significant effects on MAP viability, two distinct groups of CFS – effective and less effective – could be distinguished. The effective CFSs were extracted from various lactobacilli cultures, their pH values were mostly lower than 4.5, and their application resulted in >2 log10 reductions in MAP viability. The group of less effective CFS were filtered from Lactococcus and enterococci cultures, their pH values were higher than 4.5, and their effect on MAP viability was <2 log10. LA elicited a reduction in MAP viability that was similar to that of the group of less effective CFS. Almost no effect was found when using commercially synthetized nisin at concentrations of 0.1–1000 μg/ml. A combination of the influence of the type of bacteriocin, the length of its action, bacteriocin production strain, and pH are all probably required for a successful reduction in MAP viability. However, certain bacteriocins and their respective LAB strains (Lactobacillus sp. appear to play a greater role in reducing the viability of MAP than pH.

  18. Significant thermal energy reduction in lactic acid production process

    International Nuclear Information System (INIS)

    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.

  19. Environmental impacts of producing bioethanol and biobased lactic acid from standalone and integrated biorefineries using a consequential and an attributional life cycle assessment approach.

    Science.gov (United States)

    Parajuli, Ranjan; Knudsen, Marie Trydeman; Birkved, Morten; Djomo, Sylvestre Njakou; Corona, Andrea; Dalgaard, Tommy

    2017-11-15

    This study evaluates the environmental impacts of biorefinery products using consequential (CLCA) and attributional (ALCA) life cycle assessment (LCA) approaches. Within ALCA, economic allocation method was used to distribute impacts among the main products and the coproducts, whereas within the CLCA system expansion was adopted to avoid allocation. The study seeks to answer the questions (i) what is the environmental impacts of process integration?, and (ii) do CLCA and ALCA lead to different conclusions when applied to biorefinery?. Three biorefinery systems were evaluated and compared: a standalone system producing bioethanol from winter wheat-straw (system A), a standalone system producing biobased lactic acid from alfalfa (system B), and an integrated biorefinery system (system C) combining the two standalone systems and producing both bioethanol and lactic acid. The synergy of the integration was the exchange of useful energy necessary for biomass processing in the two standalone systems. The systems were compared against a common reference flow: "1MJ EtOH +1kg LA ", which was set on the basis of products delivered by the system C. Function of the reference flow was to provide service of both fuel (bioethanol) at 99.9% concentration (wt. basis) and biochemical (biobased lactic acid) in food industries at 90% purity; both products delivered at biorefinery gate. The environmental impacts of interest were global warming potential (GWP 100 ), eutrophication potential (EP), non-renewable energy (NRE) use and the agricultural land occupation (ALO). Regardless of the LCA approach adopted, system C performed better in most of the impact categories than both standalone systems. The process wise contribution to the obtained environmental impacts also showed similar impact pattern in both approaches. The study also highlighted that the recirculation of intermediate materials, e.g. C 5 sugar to boost bioethanol yield and that the use of residual streams in the energy

  20. Enhancement in ex vivo phagocytic capacity of peritoneal leukocytes in mice by oral delivery of various lactic-acid-producing bacteria.

    Science.gov (United States)

    Lee, Yeonhee; Lee, Taik-Soo

    2005-01-01

    Lactic-acid-producing bacteria (LABs) are known to have immunomodulating activity. In the current study, various LABs were tested for their immunity-enhancing activity, especially the phagocytic activity of leukocytes. Viable but not heat-killed cells of Weissella kimchii strain PL9001, Lactobacillus fermentum strain PL9005, and L. plantarum strain PL9011 significantly increased the ex vivo phagocytic capacity of mouse peritoneal leukocytes to ingest fluorescein isothiocyanate (FITC)-labeled Escherichia coli in a strain-dependent manner. Results of this and previous studies suggest these LABs as candidates for new probiotics. This is the first report of the enhancement of peritoneal leukocyte activity of these species.

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

    DEFF Research Database (Denmark)

    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...

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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

  6. 21 CFR 862.1450 - Lactic acid test system.

    Science.gov (United States)

    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...

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

    NARCIS (Netherlands)

    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

  8. Identification and partial characterization of lactic acid bacteria isolated from traditional dairy products produced by herders in the western Tianshan Mountains of China.

    Science.gov (United States)

    Zuo, F L; Feng, X J; Chen, L L; Chen, S W

    2014-11-01

    Thirty strains of lactic acid bacteria (LAB) were isolated from herders' traditional dairy products collected from Xinjiang, China. The species Lactobacillus, Lactococcus, Enterococcus, Pediococcus and Leuconostoc were identified by 16S ribosomal RNA gene sequencing analysis and conventional observation. The strains' fermentation characteristics, including milk acidification, proteolysis, autolysis, antimicrobial activity and diacetyl production, were assayed and compared. Strains NL24 and NL31 showed the highest proteolytic activity-2·75 and 2·08 mmol Phe l(-1) milk, respectively. Strains C, NL41, SW2, Z3-11, NL42 and Z2-91 had high autolytic activity. In addition, most of the wild strains produced diacetyl, half of them to high levels. This study provides a clue to LAB biodiversity in traditional dairy foods produced by herders in the western Tianshan Mountains. High-performing strains should be further evaluated for practical application in value-added fermented dairy products. Our results reveal a certain variety of lactic acid bacteria (LAB) in traditional dairy products from Xinjiang. Some of the LAB strains, such as Lactobacillus rhamnosus NL24 and Lactobacillus paracasei SW2, possess excellent functional properties and have the potential for application in indigenous fermented dairy products. Performance of the newly isolated strains in cheese or yogurt manufacturing was further evaluated. Application of the high-performing strains to enrich the flavour of fermented dairy products is highly desirable and holds great commercial potential. © 2014 The Society for Applied Microbiology.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    African Journals Online (AJOL)

    ... 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 ...

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

    Directory of Open Access Journals (Sweden)

    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.

  12. Chopped basalt fibres: A new perspective in reinforcing poly(lactic acid to produce injection moulded engineering composites from renewable and natural resources

    Directory of Open Access Journals (Sweden)

    P. Tamas

    2013-02-01

    Full Text Available This paper focuses on the reinforcing of Poly(lactic acid with chopped basalt fibres by using silane treated and untreated basalt fibres. Composite materials with 5–10–15–20–30–40 wt% basalt fibre contents were prepared from silane sized basalt fibres using extrusion, and injection moulding, while composites with 5–10–15 wt% basalt fibre contents were also prepared by using untreated basalt fibres as control. The properties of the injection moulded composites were extensively examined by using quasi-static (tensile, three-point bending and dynamic mechanical tests (notched and unnotched Charpy impact tests, dynamic mechanical analysis (DMA, differential scanning calorimetry (DSC, heat deflection temperature (HDT analysis, dimensional stability test, as well as melt flow index (MFI analysis and scanning electron microscopic (SEM observations. It was found that silane treated chopped basalt fibres are much more effective in reinforcing Poly(lactic acid than natural fibres; although basalt fibres are not biodegradable but they are still considered as natural (can be found in nature in the form of volcanic rocks and biologically inert. It is demonstrated in this paper that by using basalt fibre reinforcement, a renewable and natural resource based composite can be produced by injection moulding with excellent mechanical properties suitable even for engineering applications. Finally it was shown that by using adequate drying of the materials, composites with higher mechanical properties can be achieved compared to literature data.

  13. Influence of baking enzymes on antimicrobial activity of five bacteriocin-like inhibitory substances produced by lactic acid bacteria isolated from Lithuanian sourdoughs.

    Science.gov (United States)

    Narbutaite, V; Fernandez, A; Horn, N; Juodeikiene, G; Narbad, A

    2008-12-01

    To evaluate the effect of four different baking enzymes on the inhibitory activity of five bacteriocin-like inhibitory substances (BLIS) produced by lactic acid bacteria (LAB) isolated from Lithuanian sourdoughs. The overlay assay and the Bioscreen methods revealed that the five BLIS exhibited an inhibitory effect against spore germination and vegetative outgrowth of Bacillus subtilis, the predominant species causing ropiness in bread. The possibility that the observed antibacterial activity of BLIS might be lost after treatment with enzymes used for baking purposes was also examined. The enzymes tested; hemicellulase, lipase, amyloglucosidase and amylase had little or no effect on the majority of the antimicrobial activities associated with the five BLIS studied. This study suggests a potential application in the sourdough baking industry for these antimicrobial producing LAB strains in the control of B. subtilis spore germination and vegetative outgrowth.

  14. The γ-aminobutyric acid-producing ability under low pH conditions of lactic acid bacteria isolated from traditional fermented foods of Ishikawa Prefecture, Japan, with a strong ability to produce ACE-inhibitory peptides.

    Science.gov (United States)

    Barla, Florin; Koyanagi, Takashi; Tokuda, Naoko; Matsui, Hiroshi; Katayama, Takane; Kumagai, Hidehiko; Michihata, Toshihide; Sasaki, Tetsuya; Tsuji, Atsushi; Enomoto, Toshiki

    2016-06-01

    Many traditional fermented products are onsumed in Ishikawa Prefecture, Japan, such as kaburazushi , narezushi , konkazuke , and ishiru. Various kinds of lactic acid bacteria (LAB) are associated with their fermentation, however, characterization of LAB has not yet been elucidated in detail. In this study, we evaluated 53 isolates of LAB from various traditional fermented foods by taxonomic classification at the species level by analyzing the 16S ribosomal RNA gene (rDNA) sequences and carbohydrate assimilation abilities. We screened isolates that exhibited high angiotensin-converting enzyme (ACE) inhibitory activities in skim milk or soy protein media and produced high γ-aminobutyric acid (GABA) concentrations in culture supernatants when grown in de Man Rogosa Sharpe broth in the presence of 1% (w/v) glutamic acid. The results revealed that 10 isolates, i.e., Lactobacillus buchneri (2 isolates), Lactobacillus brevis (6 isolates), and Weissella hellenica (2 isolates) had a high GABA-producing ability of >500 mg/100 ml after 72 h of incubation at 35 °C. The ACE inhibitory activity of the whey cultured with milk protein by using L. brevis (3 isolates), L. buchneri (2 isolates), and W. hellenica (2 isolates) was stronger than that of all whey cultured with soy protein media, and these IC 50 were GABA-producing activities at pH 3, suggesting that they could be powerful candidates for use in the fermentation of food materials having low pH.

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

    OpenAIRE

    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...

  16. Vinegar production from post-distillation slurry deriving from rice shochu production with the addition of caproic acid-producing bacteria consortium and lactic acid bacterium.

    Science.gov (United States)

    Yuan, Hua-Wei; Tan, Li; Chen, Hao; Sun, Zhao-Yong; Tang, Yue-Qin; Kida, Kenji

    2017-12-01

    To establish a zero emission process, the post-distillation slurry of a new type of rice shochu (NTRS) was used for the production of health promoting vinegar. Since the NTRS post-distillation slurry contained caproic acid and lactic acid, the effect of these two organic acids on acetic acid fermentation was first evaluated. Based on these results, Acetobacter aceti CICC 21684 was selected as a suitable strain for subsequent production of vinegar. At the laboratory scale, acetic acid fermentation of the NTRS post-distillation slurry in batch mode resulted in an acetic acid concentration of 41.9 g/L, with an initial ethanol concentration of 40 g/L, and the acetic acid concentration was improved to 44.5 g/L in fed-batch mode. Compared to the NTRS post-distillation slurry, the vinegar product had higher concentrations of free amino acids and inhibition of angiotensin I converting enzyme activity. By controlling the volumetric oxygen transfer coefficient to be similar to that of the laboratory scale production, 45 g/L of acetic acid was obtained at the pilot scale, using a 75-L fermentor with a working volume of 40 L, indicating that vinegar production can be successfully scaled up. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  17. PHAGE RESISTANT LACTIC ACID BACTERIAL MUTANTS

    DEFF Research Database (Denmark)

    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...

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

    Science.gov (United States)

    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.

  19. 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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  1. The γ-aminobutyric acid-producing ability under low pH conditions of lactic acid bacteria isolated from traditional fermented foods of Ishikawa Prefecture, Japan, with a strong ability to produce ACE-inhibitory peptides

    Directory of Open Access Journals (Sweden)

    Florin Barla

    2016-06-01

    Full Text Available Many traditional fermented products are onsumed in Ishikawa Prefecture, Japan, such as kaburazushi, narezushi, konkazuke, and ishiru. Various kinds of lactic acid bacteria (LAB are associated with their fermentation, however, characterization of LAB has not yet been elucidated in detail. In this study, we evaluated 53 isolates of LAB from various traditional fermented foods by taxonomic classification at the species level by analyzing the 16S ribosomal RNA gene (rDNA sequences and carbohydrate assimilation abilities. We screened isolates that exhibited high angiotensin-converting enzyme (ACE inhibitory activities in skim milk or soy protein media and produced high γ-aminobutyric acid (GABA concentrations in culture supernatants when grown in de Man Rogosa Sharpe broth in the presence of 1% (w/v glutamic acid. The results revealed that 10 isolates, i.e., Lactobacillus buchneri (2 isolates, Lactobacillus brevis (6 isolates, and Weissella hellenica (2 isolates had a high GABA-producing ability of >500 mg/100 ml after 72 h of incubation at 35 °C. The ACE inhibitory activity of the whey cultured with milk protein by using L. brevis (3 isolates, L. buchneri (2 isolates, and W. hellenica (2 isolates was stronger than that of all whey cultured with soy protein media, and these IC50 were < 1 mg protein/ml. Three of 10 isolates had high GABA-producing activities at pH 3, suggesting that they could be powerful candidates for use in the fermentation of food materials having low pH.

  2. The impact of lactic acid bacteria on sourdough fermentation

    Directory of Open Access Journals (Sweden)

    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.

  3. Lactic acid bacteria: microbiological and functional aspects

    National Research Council Canada - National Science Library

    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...

  4. Lignin poly(lactic acid) copolymers

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Antimicrobial susceptibility of lactic acid bacteria isolated from human and food-producing animal feces in Khon Kaen Province, Thailand.

    Science.gov (United States)

    Sornplang, Pairat; Sakulsawasdiphan, Kattinet; Piyadeatsoontorn, Sudthidol; Surasorn, Benyapha

    2016-12-01

    The aim of this study was to investigate the susceptibility of 93 Lactobacillus strains to seven antimicrobial agents, i.e., penicillin G, amoxicillin-clavulanic acid, vancomycin, tetracycline, streptomycin, ciprofloxacin, and sulfamethoxazole-trimethoprim, by disk diffusion test. The Lactobacillus strains were isolated from fecal samples taken from 90 healthy, food-producing animals (fattening pigs, free-grazing ducks, and beef cattle) and 30 healthy human subjects (1- to 6-year-olds) in Khon Kaen. The minimum inhibitory concentration (MIC) values of tetracycline and ciprofloxacin against all strains were determined using the E-test. All 93 Lactobacillus isolates were identified at the species level using 16S rRNA gene sequencing. The most common species of Lactobacillus isolated from fattening pigs, free-grazing ducks, beef cattle, and humans were L. reuteri (30 %), L. salivarius (46.7 %), L. acetotolerans (20 %), and L. gasseri (33.3 %), respectively. A total of 83 Lactobacillus strains were resistant to the examined antibiotics. Some strains were resistant to two to six types of antibiotics. More than 50 % of Lactobacillus species were intrinsically resistant to vancomycin, streptomycin, ciprofloxacin, and sulfamethoxazole-trimethoprim. The prevalence of acquired resistance to tetracycline was observed for Lactobacillus isolates from fattening pigs, humans, free-grazing ducks, and beef cattle at 92.3, 85.7, 77.8, and 68.4 %, respectively. These results demonstrate the impact of antibiotic use in human and veterinary medicine on antibiotic treatment efficacy and may support the spread of transferable antibiotic resistant genes to other bacteria via the food chain.

  6. Inactivation of exopolysaccharide and 3-hydroxypropionaldehyde-producing lactic acid bacteria in apple juice and apple cider by enterocin AS-48.

    Science.gov (United States)

    Martínez-Viedma, Pilar; Abriouel, Hikmate; Omar, Nabil Ben; Valdivia, Eva; López, Rosario Lucas; Gálvez, Antonio

    2008-03-01

    The bacteriocin enterocin AS-48 was tested against exopolysaccharide producing lactic acid bacteria (LAB) strains of Lactobacillus collinoides, Lactobacillus dioliovorans and Pediococcus parvulus as well as two 3-hydroxypropionaldehyde (3-HPA)-producing Lb. collinoides strains causing apple cider spoilage. In fresh-made apple juice, a bacteriocin concentration of 2.5 microg/ml reduced the LAB viable cell counts below detection levels during the course of incubation at 10 and 22 degrees C for most strains tested, except for Lb. collinoides 5 and Lb. dioliovorans 29. These two strains were significantly inhibited at 10 degrees C by 5 microg/ml AS-48 or completely inactivated at 22 degrees C. In a commercial Basque apple cider, the added bacteriocin (2.5 microg/ml for Lb. collinoides strains 9 and 10, and 5 microg/ml for the rest of strains) completely inactivated all LAB strains tested during storage at 10 as well as 22 degrees C. In the commercial Asturian apple cider tested the LAB strains showed a poor capacity for survival, but the added bacteriocin was equally effective in reducing the numbers of survivors. When a cocktail of the five LAB strains was tested in commercial Basque apple cider, viable cell counts were reduced below detection levels after 2 days for a bacteriocin concentration of 12.5 microg/ml regardless of storage temperature. Comparison of RAPD-PCR profiles revealed that strain Lb. dioliovorans 29 was always the predominant survivor detected in bacteriocin-treated samples.

  7. Modulation of allergic immune responses by mucosal application of recombinant lactic acid bacteria producing the major birch pollen allergen Bet v 1.

    Science.gov (United States)

    Daniel, C; Repa, A; Wild, C; Pollak, A; Pot, B; Breiteneder, H; Wiedermann, U; Mercenier, A

    2006-07-01

    Probiotic lactic acid bacteria (LAB) are able to modulate the host immune system and clinical trials have demonstrated that specific strains have the capacity to reduce allergic symptoms. Therefore, we aimed to evaluate the potential of recombinant LAB producing the major birch pollen allergen Bet v 1 for mucosal vaccination against birch pollen allergy. Recombinant Bet v 1-producing Lactobacillus plantarum and Lactococcus lactis strains were constructed. Their immunogenicity was compared with purified Bet v 1 by subcutaneous immunization of mice. Intranasal application of the live recombinant strains was performed to test their immunomodulatory potency in a mouse model of birch pollen allergy. Bet v 1 produced by the LAB was recognized by monoclonal anti-Bet v 1 and IgE antibodies from birch pollen-allergic patients. Systemic immunization with the recombinant strains induced significantly lower IgG1/IgG2a ratios compared with purified Bet v 1. Intranasal pretreatment led to reduced allergen-specific IgE vs enhanced IgG2a levels and reduced interleukin (IL)-5 production of splenocytes in vitro, indicating a shift towards non-allergic T-helper-1 (Th1) responses. Airway inflammation, i.e. eosinophils and IL-5 in lung lavages, was reduced using either Bet v 1-producing or control strains. Allergen-specific secretory IgA responses were enhanced in lungs and intestines after pretreatment with only the Bet v 1-producing strains. Mucosal vaccination with live recombinant LAB, leading to a shift towards non-allergic immune responses along with enhanced allergen-specific mucosal IgA levels offers a promising approach to prevent systemic and local allergic immune responses.

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

    DEFF Research Database (Denmark)

    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...

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

    Science.gov (United States)

    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.

  10. Towards lactic acid bacteria-based biorefineries.

    Science.gov (United States)

    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.

  11. Microbial granulation for lactic acid production

    DEFF Research Database (Denmark)

    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...

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  14. Lactic acid fermentation of crude sorghum extract

    Energy Technology Data Exchange (ETDEWEB)

    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.

  15. Mesophilic Lactic Acid Bacteria Diversity Encountered in Brazilian Farms Producing Milk with Particular Interest in Lactococcus lactis Strains.

    Science.gov (United States)

    Luiz, L M P; Chuat, V; Madec, M N; Araújo, E A; de Carvalho, A F; Valence, F

    2016-10-01

    The milk produced in regions with different traditions in Brazil is used for artisanal product production, which is characterized by different sensorial characteristics. This study aimed to identify the bacterial ecosystem of farms located in a traditional dairy region in the state of Minas Gerais and to characterize Lactococcus lactis strains, the species of interest in this study, using a multilocus sequence typing (MLST) protocol and pulsed-field gel electrophoresis (PFGE) technique. Samples were collected from raw milk and dairy environment from six farms. A total of 50 isolates were analyzed using 16S rRNA sequencing and species-specific PCR. Five genera were identified: Lactobacillus, Leuconostoc, Lactococcus, Enterococcus, and Staphylococcus, from ten different species. MLST (with six housekeeping genes) and PFGE (with SmaI endonuclease) were used for the characterization of 20 isolates of Lactococcus lactis from a dairy collection in this study. Both methods revealed a high clonal diversity of strains with a higher discriminatory level for PFGE (15 pulsotypes), compared to MLST (12 ST). This study contributes to the preservation of the Brazilian dairy heritage and provides insights into a part of the LAB population found in raw milk and dairy environment.

  16. Amino acids transport in lactic streptococci

    NARCIS (Netherlands)

    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:

  17. Evaluation of yogurt and various beverages as carriers of lactic acid bacteria producing 2-branched (1,3)-β-D-glucan.

    Science.gov (United States)

    Elizaquível, P; Sánchez, G; Salvador, A; Fiszman, S; Dueñas, M T; López, P; Fernández de Palencia, P; Aznar, R

    2011-07-01

    Probiotic cultures are increasingly being incorporated into a wide variety of food products. Although lactobacilli and bifidobacteria are the most frequently used, other lactic acid bacteria (LAB) have been reported to be potential probiotics. Of these, the cider isolates Pediococccus parvulus (strains 2.6 and CUPV22) and Lactobacillus suebicus CUPV221 produce a 2-branched (1,3)-β-d-glucan exopolysaccharide that decreases serum cholesterol levels and affects the activation of human macrophages. For this reason, these 3 strains were incorporated into yogurt, orange juice, and 2 juice-milk beverages to evaluate the effect of the food matrix on the resistance of these strains to simulated gastrointestinal tract conditions. Our results showed that incorporation of the LAB did not significantly affect the physical and rheological properties of the food matrices tested. When incorporated in yogurt, LAB strains population decreased by 2 to 3 log orders of magnitude during the shelf life of the product (28 d). However, no significant decrease was observed in the juice and juice-milk beverages during the same storage period, except for Lb. suebicus, whose viability decreased by 3 log orders of magnitude. When strains were subjected to gastrointestinal tract conditions, a decrease in the survival was observed at the lower pH (1.8). However, incorporation of these LAB strains into orange juice increases their resistance to lower pH conditions, thus improving survival to gastrointestinal stress. Moreover, a protective effect was observed for P. parvulus CUPV22 and 2.6 to gastric stress in juice-milk beverages and to gastrointestinal stress in yogurt. Lactobacillus suebicus CUPV221 did not survive when incorporated into yogurt and juice-milk beverage. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

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

    OpenAIRE

    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...

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

    Science.gov (United States)

    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...

  20. DRY COMPOSITION OF STARTER CULTURES FORM LACTIC ACID MICROORGANISMS

    Directory of Open Access Journals (Sweden)

    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.

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

    African Journals Online (AJOL)

    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 ...

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    NARCIS (Netherlands)

    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

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    African Journals Online (AJOL)

    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 ...

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

    African Journals Online (AJOL)

    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, ...

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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. 

  13. Reactive extraction of lactic acid using alamine

    NARCIS (Netherlands)

    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)

  14. Multidrug transporters in lactic acid bacteria

    NARCIS (Netherlands)

    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

  15. The proteolytic systems of lactic acid bacteria

    NARCIS (Netherlands)

    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

  16. Proteolytic enzymes of lactic acid bacteria

    NARCIS (Netherlands)

    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

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

    OpenAIRE

    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...

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    NARCIS (Netherlands)

    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.

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

    Science.gov (United States)

    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.

  4. Non-sterilized fermentation of high optically pure D-lactic acid by a genetically modified thermophilic Bacillus coagulans strain.

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  7. Poly(Lactic Acid) Based Flexible Films

    OpenAIRE

    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...

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

    Science.gov (United States)

    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.

  9. Ultrasonic Monitoring of the Progress of Lactic Acid Fermentation

    Science.gov (United States)

    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.

  10. Microbial granulation for lactic acid production.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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. Biopropionic acid production via molybdenumcatalyzed deoxygenation of lactic acid

    NARCIS (Netherlands)

    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. Organic acids produced by lactic acid bacteria (Leuconostoc sp.) contribute to sensorial quality loss in modified-atmosphere-packed fresh-cut iceberg lettuce

    NARCIS (Netherlands)

    Paillart, M.J.M.; Vossen, J.M.B.M. van der; Lommen, E.; Levin, E.; Otma, E.C.; Snels, J.C.M.A.; Woltering, E.J.

    2016-01-01

    The shelf-life of fresh-cut lettuce packed in a modified atmosphere (MA) is determined by its "overall visual quality" (OVQ), being a measure of its general appearance based on colour and shape criteria. In addition to the OVQ, the development of off-flavour and acid off-smell reduces consumer

  14. Organic acids produced by lactic acid bacteria (Leuconostoc sp.) contribute to sensorial quality loss in modified-atmosphere-packed fresh-cut iceberg lettuce

    NARCIS (Netherlands)

    Paillart, M.J.M.; Vossen, van der J.M.B.M.; Lommen, E.; Levin, E.; Otma, E.C.; Snels, J.C.M.A.; Woltering, E.J.

    2016-01-01

    The shelf-life of fresh-cut lettuce packed in a modified atmosphere (MA) is determined by its "overall visual quality" (OVQ), being a measure of its general appearance based on colour and shape criteria. In addition to the OVQ, the development of off-flavour and acid off-smell reduces consumer

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

    OpenAIRE

    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...

  16. Lactic acid production from Cellobiose and xylose by engineered Saccharomyces cerevisiae

    Science.gov (United States)

    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...

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

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

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

    International Nuclear Information System (INIS)

    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)

  2. Isolation and Characterization of Lactic Acid Bacteria from Inasua

    Directory of Open Access Journals (Sweden)

    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. The possibility of lactic acid fermentation in the triticale stillage

    Directory of Open Access Journals (Sweden)

    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.

  4. Beneficial effects of antioxidative lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    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].

    Science.gov (United States)

    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

    Science.gov (United States)

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

    NARCIS (Netherlands)

    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

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

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

    International Nuclear Information System (INIS)

    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)

  13. Genome Sequence of Lactobacillus saerimneri 30a (Formerly Lactobacillus sp. Strain 30a), a Reference Lactic Acid Bacterium Strain Producing Biogenic Amines

    NARCIS (Netherlands)

    Romano, Andrea; Trip, Hein; Campbell-Sills, Hugo; Bouchez, Olivier; Sherman, David; Lolkema, Juke S.; Lucas, Patrick M.

    2013-01-01

    Lactobacillus sp. strain 30a (Lactobacillus saerimneri) produces the biogenic amines histamine, putrescine, and cadaverine by decarboxylating their amino acid precursors. We report its draft genome sequence (1,634,278 bases, 42.6% G+C content) and the principal findings from its annotation, which

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

    NARCIS (Netherlands)

    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

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

    NARCIS (Netherlands)

    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.

  16. 9th International Symposium on Lactic Acid Bacteria

    NARCIS (Netherlands)

    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

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

    NARCIS (Netherlands)

    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. Flow cytometric assessment of viability of lactic acid bacteria

    NARCIS (Netherlands)

    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

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

    African Journals Online (AJOL)

    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.

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

    African Journals Online (AJOL)

    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 ...

  1. Engineering CRISPR interference system in Klebsiella pneumoniae for attenuating lactic acid synthesis.

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  5. Safety and quality parameters of ready-to-cook minced pork meat products supplemented with Helianthus tuberosus L. tubers fermented by BLIS producing lactic acid bacteria.

    Science.gov (United States)

    Stimbirys, Arturas; Bartkiene, Elena; Siugzdaite, Jurate; Augeniene, Dovile; Vidmantiene, Daiva; Juodeikiene, Grazina; Maruska, Audrius; Stankevicius, Mantas; Cizeikiene, Dalia

    2015-07-01

    The aim of this study was to evaluate the influence of additives of Jerusalem artichoke (JA), fermented with P. acidilactici KTU05-7, P. pentosaceus KTU05-9, L. sakei KTU05-6, on the quality and safety parameters of ready - to cook - minced pork (RCMP). Fermented JA additives reduced pH of the meat products and decreased water holding capacity (WHC) from 2.01 till 2.93 %. Concentrations of biogenic amines in RCMP with additives of the lactic acid bacteria (LAB) - fermented JA were significantly lower comparing with control sample. The number of pathogenic bacteria in artificially contaminated meat samples was significantly reduced in case of LAB-fermented JA additives. The highest antimicrobial activity was obtained using P. acidilactici fermented JA additives. The amounts of microbial pathogens E. coli and Ent. faecalis, S. aureus and Streptococcus spp. were determined 3.41, 3.38, 3,96 and 4.74 log CFU/g correspondingly, whereas without LAB-fermented JA additives were 8.94, 7.75, 8.82 and 8.58 log CFU/g, correspondingly. A possibility to improve sensory properties (flavor) of RCMP using LAB fermented JA additives was investigated. The composition of volatile compounds of RCMP without additive and with LAB-fermented JA additives was analyzed using gas chromatography-mass spectrometry (GC-MS). The results of sensory evaluation of meat products supplemented with fermented JA additives revealed specific odor, which is pleasant and acceptable for consumers might be explainable that LAB-fermented JA additives have shown considerable differences mainly due to the accumulation of volatiles such as toluene, ethylbenzene, decane, undecane, 2 methyl undecane. N-morpholinomethyl-isopropyl-sulfide, 6-undecilamine and N,N-dimethyl-1-pentadecanamine were not determined in RCMP with LAB-fermented JA additives. The results obtained show, that P. acidilactici fermented JA 5 % additive is most suitable for the RCMP processing in order to prevent microbiological spoilage, increase

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

    NARCIS (Netherlands)

    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

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

    NARCIS (Netherlands)

    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

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

    African Journals Online (AJOL)

    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.

  9. Screening local Lactobacilli from Iran in terms of production of lactic acid and identification of superior strains

    Directory of Open Access Journals (Sweden)

    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.

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

    OpenAIRE

    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...

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

    Science.gov (United States)

    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.

  12. Lactic acid demineralization of shrimp shell and chitosan synthesis

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Optimization of lactic acid production from glucose using geobacillus stearothermophilus strain 15

    Science.gov (United States)

    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.

  15. OPTIMIZATION OF VEGETABLE WASTES FOR LACTIC ACID PRODUCTION: A LABORATORY SCALE APPROACH

    Directory of Open Access Journals (Sweden)

    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.

  16. Cell immobilization for production of lactic acid biofilms do it naturally.

    Science.gov (United States)

    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.

    Science.gov (United States)

    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. Conversion of Aqueous Ammonia-Treated Corn Stover to Lactic Acid by Simultaneous Saccharification and Cofermentation

    Science.gov (United States)

    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.

  19. Production of lactic acid from sucrose: strain selection, fermentation, and kinetic modeling.

    Science.gov (United States)

    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.

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

    African Journals Online (AJOL)

    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

    African Journals Online (AJOL)

    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 ...

    African Journals Online (AJOL)

    $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

    Directory of Open Access Journals (Sweden)

    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 ...

    African Journals Online (AJOL)

    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

    African Journals Online (AJOL)

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

    African Journals Online (AJOL)

    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 ...

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

    African Journals Online (AJOL)

    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.

  8. Lactic acid production by irradiated Bacillus NF17 and poly-L-lactate biopolymer formation

    International Nuclear Information System (INIS)

    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

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

    OpenAIRE

    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 ...

  10. Materials and methods for efficient lactic acid production

    Science.gov (United States)

    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.

  11. Validation of a hot water rinse and lactic acid spray in combination with scaling for treating hide-on carcasses to control biotype I strains of Escherichia coli used as surrogates for Shiga toxin-producing E. coli

    Science.gov (United States)

    Scalding of hide-on bob veal carcasses with or without standard scalding chemical agents typically used for hogs, followed by an 82.2degreeC hot water wash and lactic acid spray (applied at ambient temperature) prior to chilling, was evaluated to determine its effectiveness in reducing the levels of...

  12. Isolation of lactic acid bacteria from kantong, a condiment produced from the fermentation of kapok (Ceiba pentandra) seeds and cassava (Manihot esculentum) flour

    DEFF Research Database (Denmark)

    Kpikpi, Elmer Nayra; Glover, Richard L.K.; Dzogbefia, Victoria Pearl

    2010-01-01

    in the initial pH from 6.9 before fermentation to 4.9 after fermentation with change in color of the product from grayish to dark brown as well as the development of a more desirable flavor. Lactic acid bacteria (LAB) with counts between 106 and 109 cfu/g were isolated on MRS agar and subjected to Gram, catalase...

  13. Effect of Pyruvate Decarboxylase Knockout on Product Distribution Using Pichia pastoris (Komagataella phaffii) Engineered for Lactic Acid Production.

    Science.gov (United States)

    Melo, Nadiele T M; Mulder, Kelly C L; Nicola, André Moraes; Carvalho, Lucas S; Menino, Gisele S; Mulinari, Eduardo; Parachin, Nádia S

    2018-02-16

    Lactic acid is the monomer unit of the bioplastic poly-lactic acid (PLA). One candidate organism for lactic acid production is Pichia pastoris , a yeast widely used for heterologous protein production. Nevertheless, this yeast has a poor fermentative capability that can be modulated by controlling oxygen levels. In a previous study, lactate dehydrogenase (LDH) activity was introduced into P. pastoris, enabling this yeast to produce lactic acid. The present study aimed to increase the flow of pyruvate towards the production of lactic acid in P. pastoris . To this end, a strain designated GLp was constructed by inserting the bovine lactic acid dehydrogenase gene (LDHb) concomitantly with the interruption of the gene encoding pyruvate decarboxylase (PDC). Aerobic fermentation, followed by micro-aerophilic culture two-phase fermentations, showed that the GLp strain achieved a lactic acid yield of 0.65 g/g. The distribution of fermentation products demonstrated that the acetate titer was reduced by 20% in the GLp strain with a concomitant increase in arabitol production: arabitol increased from 0.025 g/g to 0.174 g/g when compared to the GS115 strain. Taken together, the results show a significant potential for P. pastoris in producing lactic acid. Moreover, for the first time, physiological data regarding co-product formation have indicated the redox balance limitations of this yeast.

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

    Science.gov (United States)

    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. Heat capacity of poly(lactic acid)

    International Nuclear Information System (INIS)

    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

  16. Antibiotic resistance of lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    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.

  17. Zinc Binding by Lactic Acid Bacteria

    Directory of Open Access Journals (Sweden)

    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.

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

    OpenAIRE

    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...

  19. Vaginal pH and microbicidal lactic acid when lactobacilli dominate the microbiota.

    Science.gov (United States)

    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.

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

    International Nuclear Information System (INIS)

    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.

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

    African Journals Online (AJOL)

    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 ...

  2. Effects of cultivation conditions on folate production by lactic acid bacteria

    NARCIS (Netherlands)

    Sybesma, W.; Starrenburg, M.; Tijsseling, L.; Hoefnagel, M.H.N.; Hugenholtz, J.

    2003-01-01

    A variety of lactic acid bacteria were screened for their ability to produce folate intracellularly and/or extracellularly. Lactococcus lactis, Streptococcus thermophilus, and Leuconostoc spp. all produced folate, while most Lactobacillus spp., with the exception of Lactobacillus plantarum, were not

  3. Genetics of the proteolytic system of lactic acid bacteria

    NARCIS (Netherlands)

    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

  4. Stress Physiology of Lactic Acid Bacteria

    Science.gov (United States)

    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

  5. Production of D- and L-Lactic Acid by Mono- and Mixed Cultures of Lactobacillus sp.

    Directory of Open Access Journals (Sweden)

    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.

  6. Lactic Acid Bacteria Exopolysaccharides in Foods and Beverages: Isolation, Properties, Characterization, and Health Benefits.

    Science.gov (United States)

    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.

  7. Comparative analysis of microbial community of novel lactic acid fermentation inoculated with different undefined mixed cultures.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  9. L: (+)-Lactic acid production from non-food carbohydrates by thermotolerant Bacillus coagulans.

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  11. Direct lactic acid fermentation of Jerusalem artichoke tuber extract using Lactobacillus paracasei without acidic or enzymatic inulin hydrolysis.

    Science.gov (United States)

    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.

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

    NARCIS (Netherlands)

    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

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

    African Journals Online (AJOL)

    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.

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

    African Journals Online (AJOL)

    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 ...

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

    African Journals Online (AJOL)

    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).

  16. Utilization of Encapsulated CaCO_3 in Liquid Core Capsules for Improving Lactic Acid Fermentation

    International Nuclear Information System (INIS)

    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. Characterization of lactic acid bacteria from local cow´s milk kefir

    Science.gov (United States)

    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.

  18. Production of L-lactic acid from metabolically engineered strain of Enterobacter aerogenes ATCC 29007.

    Science.gov (United States)

    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.

  19. Lactic acid fermentation of cassava dough into agbelima.

    Science.gov (United States)

    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.

  20. LPMOs in cellulase mixtures affect fermentation strategies for lactic acid production from lignocellulosic biomass.

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

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

    International Nuclear Information System (INIS)

    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)

  3. Nucleotide Metabolism and its Control in Lactic Acid Bacteria

    DEFF Research Database (Denmark)

    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....

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

    Directory of Open Access Journals (Sweden)

    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.

  5. Synergistic Extraction of Lactic Acid with Tri-n-Octylamine and Try-n-Butylphosphate

    Energy Technology Data Exchange (ETDEWEB)

    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)

  6. Synergistic Extraction of Lactic Acid with Tri-n-Octylamine and Try-n-Butylphosphate

    Energy Technology Data Exchange (ETDEWEB)

    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)

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

    Science.gov (United States)

    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.

  8. Acid and bile tolerance of spore-forming lactic acid bacteria.

    Science.gov (United States)

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

    Science.gov (United States)

    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...

  10. Characterization of airag collected in Ulaanbaatar, Mongolia with emphasis on isolated lactic acid bacteria.

    Science.gov (United States)

    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.

  11. Characterization of airag collected in Ulaanbaatar, Mongolia with emphasis on isolated lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    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.

  12. Engineering of thermotolerant Bacillus coagulans for production of D(-)-lactic acid

    Science.gov (United States)

    Wang, Qingzhao; Shanmugam, Keelnatham T; Ingram, Lonnie O

    2014-12-02

    Genetically modified microorganisms having the ability to produce D(-)-lactic acid at temperatures between 30.degree. C. and 55.degree. C. are provided. In various embodiments, the microorganisms may have the chromosomal lactate dehydrogenase (ldh) gene and/or the chromosomal acetolactate synthase (alsS) gene inactivated. Exemplary microorganisms for use in the disclosed methods are Bacillus spp., such as Bacillus coagulans.

  13. Isolation of Lactic Acid Bacteria with High Biological Activity from Local Fermented Dairy Products

    OpenAIRE

    B. Munkhtsetseg; M. Margad-Erdene; B. Batjargal

    2009-01-01

    The thirty-two strains of lactic acid bacteria were isolated from the Mongolian traditional fermented dairy products, among them 25 strains show antimicrobial activity against test microorganisms including Escherichia coli , Staphylococcus aureus , Enterococcus faecalis , Pseudom о nas aeruginosa . Protease sensitivity assay demonstrated that the antimicrobial substances produced by isolates А 23, Т 2 are bacterio...

  14. Lactic acid bacteria and the human gastrointestinal tract

    DEFF Research Database (Denmark)

    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...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  17. ASIC3: A Lactic Acid Sensor for Cardiac Pain

    Directory of Open Access Journals (Sweden)

    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].

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

    OpenAIRE

    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...

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

    Science.gov (United States)

    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.

  20. Lactic acid production on brewers' spent grain hydrolysate by lactobacillus Rhamnosus and Lactobacillus fermentum

    OpenAIRE

    Pejin, Jelena; Mojović, Ljiljana; Kocić-Tanackov, Sunčica; Radosavljević, Miloš; Đukić-Vuković, Aleksandra; Nikolić, Svetlana

    2014-01-01

    Brewers' spent grain (BSG) is the major by-product of the brewing industry, representing around 85% of the total by-products generated. Per 100 L of beer produced 20 kg of brewer's spent grain are obtained. BSG is a lignocellulosic material and due to its high content of protein and fibre, it can also serve as a raw material in biotechnology i.e. in lactic acid production. In this study brewer's spent grain hydrolysate was produced using optimal conditions. Hydrolysates were used for lactic a...

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  3. 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.

    Science.gov (United States)

    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.

  4. 49-60 Characterization of Lactic Acid Bacteria from Camel Milk and the

    African Journals Online (AJOL)

    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.

  5. Highly efficient production of optically pure l-lactic acid from corn stover hydrolysate by thermophilic Bacillus coagulans.

    Science.gov (United States)

    Ma, Kedong; Hu, Guoquan; Pan, Liwei; Wang, Zichao; Zhou, Yi; Wang, Yanwei; Ruan, Zhiyong; He, Mingxiong

    2016-11-01

    A thermophilic strain Bacillus coagulans (NBRC 12714) was employed to produce l-lactic acid from corn stover hydrolysate in membrane integrated continuous fermentation. The strain NBRC 12714 metabolized glucose and xylose by the Embden-Meyerhof-Parnas pathway (EMP) and the pentose phosphate pathway (PPP), producing l-lactic acid with optical purity >99.5%. The overall l-lactic acid titer of 92g/l with a yield of 0.91g/g and a productivity of 13.8g/l/h were achieved at a dilution rate of 0.15h(-1). The productivity obtained was 1.6-fold than that of conventional continuous fermentation without cell recycling, and also was the highest among the relevant studies ever reported. These results indicated that the process developed had great potential for economical industrial production of l-lactic acid from lignocellulosic biomass. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Lactobacilli inactivate Chlamydia trachomatis through lactic acid but not H2O2.

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    OpenAIRE

    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 ...

  9. Culture-independent analysis of lactic acid bacteria diversity associated with mezcal fermentation.

    Science.gov (United States)

    Narváez-Zapata, J A; Rojas-Herrera, R A; Rodríguez-Luna, I C; Larralde-Corona, C P

    2010-11-01

    Mezcal is an alcoholic beverage obtained from the distillation of fermented juices of cooked Agave spp. plant stalks (agave must), and each region in Mexico with denomination of origin uses defined Agave species to prepare mezcal with unique organoleptic characteristics. During fermentation to produce mezcal in the state of Tamaulipas, not only alcohol-producing yeasts are involved, but also a lactic acid bacterial community that has not been characterized yet. In order to address this lack of knowledge on this traditional Mexican beverage, we performed a DGGE-16S rRNA analysis of the lactic acid bacterial diversity and metabolite accumulation during the fermentation of a typical agave must that is rustically produced in San Carlos County (Tamaulipas, Mexico). The analysis of metabolite production indicated a short but important malolactic fermentation stage not previously described for mezcal. The denaturing gradient gel electrophoresis (DGGE) analysis of the 16S rRNA genes showed a distinctive lactic acid bacterial community composed mainly of Pediococcus parvulus, Lactobacillus brevis, Lactobacillus composti, Lactobacillus parabuchneri, and Lactobacillus plantarum. Some atypical genera such as Weissella and Bacillus were also found in the residual must. Our results suggest that the lactic acid bacteria could strongly be implicated in the organoleptic attributes of this traditional Mexican distilled beverage.

  10. Physico-chemical parameter for production of lactic acid or ethanol of (corynebacterium glutamicum) bacteria

    International Nuclear Information System (INIS)

    Castellanos, Angelica; Garcia, Lina Marcela; Astudillo, Myriam; Lopez Galan, Jorge Enrique; Florez Pardo, Luz Marina.

    2011-01-01

    The interest to obtain products for the bio-fuel industry from renewable resources has directed research to find resistant and costs-effective biotechnological systems. Corynebacterium glutamicum, is a microorganism used to produce amino acids, that grows in wide variety of substrates and its resistance during fermentation to pH, temperature, osmotic pressure variations and alcohol aggregate, renders this organism a suitable candidate to improve by genetic modifications lactic acid and ethanol synthesis. However, some aspects of its physiology remain unknown, such us increase lactic acid and ethanol production from C5 and C6 sugars. For this reason, the main aim in our work was to identify the most important variables with impact on culture and the best culture conditions to produce lactic acid or ethanol in batch culture. To achieve this objective, eight variables were tested in culture using a statistical model. The best culture conditions were obtained and tested in a bacth bioreactor system. Temperature, biotin and glucose concentration were the variables with most impact (p - 1 , 16 g/l of lactic acid was obtained after 15 h of culture with an efficiency of 32%. High glucose consumption was observed during bacterial growth, which leads to low concentration of substrate for the production process; this suggests a culture feeding at the end of exponential growth phase, which can increase the production yield.

  11. Production of lactic acid from hemicellulose extracts by Bacillus coagulans MXL-9.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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....

  13. Solid state fermentation with lactic acid bacteria to improve the nutritional quality of lupin and soya bean.

    Science.gov (United States)

    Bartkiene, Elena; Krungleviciute, Vita; Juodeikiene, Grazina; Vidmantiene, Daiva; Maknickiene, Zita

    2015-04-01

    The ability of bacteriocin-like inhibitory substance (BLIS)-producing lactic acid bacteria (LAB) to degrade biogenic amines as well as to produce L(+) and D(-)-lactic acid during solid state fermentation (SSF) of lupin and soya bean was investigated. In addition, the protein digestibility and formation of organic acids during SSF of legume were investigated. Protein digestibility of fermented lupin and soya bean was found higher on average by 18.3% and 15.9%, respectively, compared to untreated samples. Tested LAB produced mainly L-lactic acid in soya bean and lupin (D/L ratio 0.38-0.42 and 0.35-0.54, respectively), while spontaneous fermentation gave almost equal amounts of both lactic acid isomers (D/L ratio 0.82-0.98 and 0.92, respectively). Tested LAB strains were able to degrade phenylethylamine, spermine and spermidine, whereas they were able to produce putrescine, histamine and tyramine. SSF improved lupin and soya bean protein digestibility. BLIS-producing LAB in lupin and soya bean medium produced a mixture of D- and L-lactic acid with a major excess of the latter isomer. Most toxic histamine and tyramine in fermented lupin and soya bean were found at levels lower those causing adverse health effects. Selection of biogenic amines non-producing bacteria is essential in the food industry to avoid the risk of amine formation. © 2014 Society of Chemical Industry.

  14. Lactic acid delays the inflammatory response of human monocytes

    Energy Technology Data Exchange (ETDEWEB)

    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.

  15. Lactic acid delays the inflammatory response of human monocytes

    International Nuclear Information System (INIS)

    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

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

    African Journals Online (AJOL)

    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 ...

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

    NARCIS (Netherlands)

    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

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

    Science.gov (United States)

    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...

  19. Lactic Acid Bacteria Differentially Activate Natural Killer Cells

    DEFF Research Database (Denmark)

    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...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    African Journals Online (AJOL)

    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.

  2. Lactic acid bacteria in a changing legislative environment

    NARCIS (Netherlands)

    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,

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

    African Journals Online (AJOL)

    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 ...

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

    Science.gov (United States)

    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.

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

    African Journals Online (AJOL)

    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 ...

  6. original article antimicrobial susceptibility pattern of lactic acid

    African Journals Online (AJOL)

    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 ...

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

    African Journals Online (AJOL)

    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 ...

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

    African Journals Online (AJOL)

    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 ...

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

    African Journals Online (AJOL)

    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 ...

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

    African Journals Online (AJOL)

    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% ...

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

    African Journals Online (AJOL)

    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 ...

  12. Controlled overproduction of proteins by lactic acid bacteria

    NARCIS (Netherlands)

    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

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

    Science.gov (United States)

    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.

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

    African Journals Online (AJOL)

    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 ...

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

    African Journals Online (AJOL)

    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 ...

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

    African Journals Online (AJOL)

    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) ...

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

    African Journals Online (AJOL)

    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 ...

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

    DEFF Research Database (Denmark)

    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...

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

    African Journals Online (AJOL)

    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 ...

  20. Lactic acid and Lactates in Health and wellness

    NARCIS (Netherlands)

    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

  1. Feasibility of converting lactic acid to ethanol in food waste fermentation by immobilized lactate oxidase

    International Nuclear Information System (INIS)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  4. [Composition diversity of lactic acid bacteria (LAB) community Al2 used for alfalfa silage].

    Science.gov (United States)

    Wang, Xiao-Fen; Gao, Li-Juan; Yang, Hong-Yan; Wang, Wei-Dong; Cui, Zong-Jun

    2006-10-01

    Alfalfa is the most important forage grass that is difficult to ensile for good quality. Using silage inoculants are the important way for preservation of alfalfa silage. Through continuous restricted subcultivation, a lactic acid bacteria (LAB) community Al2 was selected from well-fermented alfalfa silage. Plate isolation and Denaturing Gradient Gel Electrophoresis (DGGE), construction of 16S rDNA clone library were used to identify the composition diversity of Al2 community, with 7 strains detected, and they were all belonged to Lactobacillus. The composition ratios of the 7 strains were 55.21%, 19.79%, 14.58%, 3.13%, 3.13%, 3.13%, 1.03% according to 16S rDNA clone library. Al2-1i, Al2-2i, Al2-3i, corresponding to L. plantarum (99.9%), L. kimchii (99.4%), L. farciminis (100%) were detected by plate isolation. Among 3 isolates, Al2-1i had the highest ability of dropping pH and producing lactic acid, and the amount of lactic acid was reach to 18g/L at 24h cultivated in MRS media. The ability of dropping pH and producing lactic acid of Al2-3i was the lowest. From DGGE profiles, the dominant strains in Al2 community were L. plantarum and L. kimchii. L. plantarum was detected during the whole process, and L. kimchii was detected in the later phase.

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

    OpenAIRE

    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...

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

    Science.gov (United States)

    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.

  7. Lactic acid bacteria in the quality improvement and depreciation of wine.

    Science.gov (United States)

    Lonvaud-Funel, A

    1999-01-01

    The winemaking process includes two main steps: lactic acid bacteria are responsible for the malolactic fermentation which follows the alcoholic fermentation by yeasts. Both types of microorganisms are present on grapes and on cellar equipment. Yeasts are better adapted to growth in grape must than lactic acid bacteria, so the alcoholic fermentation starts quickly. In must, up to ten lactic acid bacteria species can be identified. They belong to the Lactobacillus, Pediococcus, Leuconostoc and Oenococcus genera. Throughout alcoholic fermentation, a natural selection occurs and finally the dominant species is O. oeni, due to interactions between yeasts and bacteria and between bacteria themselves. After bacterial growth, when the population is over 10(6) CFU/ml, malolactic transformation is the obvious change in wine composition. However, many other substrates can be metabolized. Some like remaining sugars and citric acid are always assimilated by lactic acid bacteria, thus providing them with energy and carbon. Other substrates such as some amino acids may be used following pathways restricted to strains carrying the adequate enzymes. Some strains can also produce exopolysaccharides. All these transformations greatly influence the sensory and hygienic quality of wine. Malic acid transformation is encouraged because it induces deacidification. Diacetyl produced from citric acid is also helpful to some extent. Sensory analyses show that many other reactions change the aromas and make malolactic fermentation beneficial, but they are as yet unknown. On the contrary, an excess of acetic acid, the synthesis of glucane, biogenic amines and precursors of ethylcarbamate are undesirable. Fortunately, lactic acid bacteria normally multiply in dry wines; moreover some of these activities are not widespread. Moreover, the most striking trait of wine lactic acid bacteria is their capacity to adapt to a hostile environment. The mechanisms for this are not yet completely elucidated

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

    Directory of Open Access Journals (Sweden)

    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.

  9. Conversion of acid hydrolysate of oil palm empty fruit bunch to L-lactic acid by newly isolated Bacillus coagulans JI12.

    Science.gov (United States)

    Ye, Lidan; Hudari, Mohammad Sufian Bin; Zhou, Xingding; Zhang, Dongxu; Li, Zhi; Wu, Jin Chuan

    2013-06-01

    Cost-effective conversion of lignocellulose hydrolysate to optically pure lactic acid is commercially attractive but very challenging. Bacillus coagulans JI12 was isolated from natural environment and used to produce L-lactic acid (optical purity > 99.5 %) from lignocellulose sugars and acid hydrolysate of oil palm empty fruit bunch (EFB) at 50 °C and pH 6.0 without sterilization of the medium. In fed-batch fermentation with 85 g/L initial xylose and 55 g/L xylose added after 7.5 h, 137.5 g/L lactic acid was produced with a yield of 98 % and a productivity of 4.4 g/L h. In batch fermentation of a sugar mixture containing 8.5 % xylose, 1 % glucose, and 1 % L-arabinose, the lactic acid yield and productivity reached 98 % and 4.8 g/L h, respectively. When EFB hydrolysate was used, 59.2 g/L of lactic acid was produced within 9.5 h at a yield of 97 % and a productivity of 6.2 g/L h, which are the highest among those ever reported from lignocellulose hydrolysates. These results indicate that B. coagulans JI12 is a promising strain for industrial production of L-lactic acid from lignocellulose hydrolysate.

  10. Selection of the Strain Lactobacillus acidophilus ATCC 43121 and Its Application to Brewers' Spent Grain Conversion into Lactic Acid

    Science.gov (United States)

    Liguori, Rossana; Soccol, Carlos Ricardo; Vandenberghe, Luciana Porto de Souza; Woiciechowski, Adenise Lorenci; Ionata, Elena; Marcolongo, Loredana; Faraco, Vincenza

    2015-01-01

    Six Lactobacillus strains were analyzed to select a bacterium for conversion of brewers' spent grain (BSG) into lactic acid. Among the investigated strains, L. acidophilus ATCC 43121 showed the highest yield of lactic acid production (16.1 g/L after 48 hours) when grown in a synthetic medium. It was then analyzed for its ability to grow on the hydrolysates obtained from BSG after acid-alkaline (AAT) or aqueous ammonia soaking (AAS) pretreatment. The lactic acid production by L. acidophilus ATCC 43121 through fermentation of the hydrolysate from AAS treated BSG was 96% higher than that from the AAT treated one, although similar yields of lactic acid per consumed glucose were achieved due to a higher (46%) glucose consumption by L. acidophilus ATCC 43121 in the AAS BSG hydrolysate. It is worth noting that adding yeast extract to the BSG hydrolysates increased both the yield of lactic acid per substrate consumed and the volumetric productivity. The best results were obtained by fermentation of AAS BSG hydrolysate supplemented by yeast extract, in which the strain produced 22.16 g/L of lactic acid (yield of 0.61 g/g), 27% higher than the value (17.49 g/L) obtained in the absence of a nitrogen source. PMID:26640784

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

    Science.gov (United States)

    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.

  12. Separation and purification of lactic acid. Thermal catalytic depolymerization of poly-lactic acid into lactide; Hakkoho nyusan no bunri seisei ni kansuru kenkyu. Pori nyusan no rakuchido eno sesshokuteki netsukai jugo

    Energy Technology Data Exchange (ETDEWEB)

    Morita, M.; Hirama, Y.; Liew, M. [Hokkaido National Industrial Research Institute, Sapporo (Japan)

    1996-05-10

    A new separation and purification method for lactic acid from fermentation broth is proposed by which poly-lactic acid produced from unpurified lactic acid is catalytically depolymerized into lactide fractions then further purified into lactide. In the present study, thermal depolymerization catalysts were investigated for commercial use. Iron catalysts, especially metallic iron, and ferrous oxide and lactate, were found to provide almost the same catalytic activity and lactide composition in depolymerization products and those in tin octoate and antimony oxide catalysts. Ferrous oxide was also applied to depolymerize poly-lactic acid derived form unpurified lactic acid to compare catalytic activity and lactide composition and was confirmed to show results similar to those of pure polymer. Based on these findings, it is concluded that iron catalysts can be used commercially. Furthermore, catalytic depolymerization of poly-lactic acids with different molecular weights were studied. Polymers with Mw 5,000-10,000 were found to be better for production of lactide, based on the behavior of depolymerization and lactide content in the product. 5 refs., 9 figs., 1 tab.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  15. Antibacterial Activity of Some Lactic Acid Bacteria Isolated from an Algerian Dairy Product

    International Nuclear Information System (INIS)

    Mezaini, A.; Bouras, A.D.; Mezaini, A.; Chihib, N.; Nedjar-Arroume, N.; Hornez, J.P.

    2010-01-01

    In the present study, the antibacterial effect of 20 lactic acid bacteria isolates from a traditional cheese was investigated. 6 isolates showed antibacterial effect against Gram positive bacteria. Streptococcus thermophilus T2 strain showed the wide inhibitory spectrum against the Gram positive bacteria. Growth and bacitracin production profiles showed that the maximal bacitracin production, by S. thermophilus T2 cells, was measured by the end of the late-log phase (90 AU ml -1 ) with a bacterio cine production rate of 9.3 (AU ml -1 ) h -1 . In addition, our findings showed that the bacitracin, produced by S. thermophilus T2, was stable over a wide ph range (4-8); this indicates that such bacitracin may be useful in acidic as well as non acidic food. This preliminarily work shows the potential application of autochthonous lactic acid bacteria to improve safety of traditional fermented food.

  16. Efficient production of L-lactic acid by newly isolated thermophilic Bacillus coagulans WCP10-4 with high glucose tolerance.

    Science.gov (United States)

    Zhou, Xingding; Ye, Lidan; Wu, Jin Chuan

    2013-05-01

    A thermophilic Bacillus coagulans WCP10-4 with tolerance to high concentration of glucose was isolated from soil and used to produce optically pure L-lactic acid from glucose and starch. In batch fermentation at pH 6.0, 240 g/L of glucose was completely consumed giving 210 g/L of L-lactic acid with a yield of 95 % and a productivity of 3.5 g/L/h. In simultaneous saccharification and fermentation at 50 °C without sterilizing the medium, 200 g/L of corn starch was completely consumed producing 202.0 g/L of L-lactic acid. To the best of our knowledge, this strain shows the highest osmotic tolerance to glucose among the strains ever reported for lactic acid production. This is the first report of simultaneous saccharification and fermentation of starch for lactic acid production under a non-sterilized condition.

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

    Science.gov (United States)

    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. Lactic acid production from biomass-derived sugars via co-fermentation of Lactobacillus brevis and Lactobacillus plantarum.

    Science.gov (United States)

    Zhang, Yixing; Vadlani, Praveen V

    2015-06-01

    Lignocellulosic biomass is an attractive alternative resource for producing chemicals and fuels. Xylose is the dominating sugar after hydrolysis of hemicellulose in the biomass, but most microorganisms either cannot ferment xylose or have a hierarchical sugar utilization pattern in which glucose is consumed first. To overcome this barrier, Lactobacillus brevis ATCC 367 was selected to produce lactic acid. This strain possesses a relaxed carbon catabolite repression mechanism that can use glucose and xylose simultaneously; however, lactic acid yield was only 0.52 g g(-1) from a mixture of glucose and xylose, and 5.1 g L(-1) of acetic acid and 8.3 g L(-1) of ethanol were also formed during production of lactic acid. The yield was significantly increased and ethanol production was significantly reduced if L. brevis was co-cultivated with Lactobacillus plantarum ATCC 21028. L. plantarum outcompeted L. brevis in glucose consumption, meaning that L. brevis was focused on converting xylose to lactic acid and the by-product, ethanol, was reduced due to less NADH generated in the fermentation system. Sequential co-fermentation of L. brevis and L. plantarum increased lactic acid yield to 0.80 g g(-1) from poplar hydrolyzate and increased yield to 0.78 g lactic acid per g of biomass from alkali-treated corn stover with minimum by-product formation. Efficient utilization of both cellulose and hemicellulose components of the biomass will improve overall lactic acid production and enable an economical process to produce biodegradable plastics. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  19. Highly efficient production of L-lactic acid from xylose by newly isolated Bacillus coagulans C106.

    Science.gov (United States)

    Ye, Lidan; Zhou, Xingding; Hudari, Mohammad Sufian Bin; Li, Zhi; Wu, Jin Chuan

    2013-03-01

    Cost-effective production of optically pure lactic acid from lignocellulose sugars is commercially attractive but challenging. Bacillus coagulans C106 was isolated from environment and used to produce l-lactic acid from xylose at 50°C and pH 6.0 in mineral salts medium containing 1-2% (w/v) of yeast extract without sterilizing the medium before fermentation. In batch fermentation with 85g/L of xylose, lactic acid titer and productivity reached 83.6g/L and 7.5g/Lh, respectively. When fed-batch (120+80+60g/L) fermentation was applied, they reached 215.7g/L and 4.0g/Lh, respectively. In both cases, the lactic acid yield and optical purity reached 95% and 99.6%, respectively. The lactic acid titer and productivity on xylose are the highest among those ever reported. Ca(OH)2 was found to be a better neutralizing agent than NaOH in terms of its giving higher lactic acid titer (1.2-fold) and productivity (1.8-fold) under the same conditions. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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.

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

    CERN Document Server

    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.

  2. Lactic Acid Production from Pretreated Hydrolysates of Corn Stover by a Newly Developed Bacillus coagulans Strain

    Science.gov (United States)

    Jiang, Ting; Qiao, Hui; Zheng, Zhaojuan; Chu, Qiulu; Li, Xin; Yong, Qiang; Ouyang, Jia

    2016-01-01

    An inhibitor-tolerance strain, Bacillus coagulans GKN316, was developed through atmospheric and room temperature plasma (ARTP) mutation and evolution experiment in condensed dilute-acid hydrolysate (CDH) of corn stover. The fermentabilities of other hydrolysates with B. coagulans GKN316 and the parental strain B. coagulans NL01 were assessed. When using condensed acid-catalyzed steam-exploded hydrolysate (CASEH), condensed acid-catalyzed liquid hot water hydrolysate (CALH) and condensed acid-catalyzed sulfite hydrolysate (CASH) as substrates, the concentration of lactic acid reached 45.39, 16.83, and 18.71 g/L by B. coagulans GKN316, respectively. But for B. coagulans NL01, only CASEH could be directly fermented to produce 15.47 g/L lactic acid. The individual inhibitory effect of furfural, 5-hydroxymethylfurfural (HMF), vanillin, syringaldehyde and p-hydroxybenzaldehyde (pHBal) on xylose utilization by B. coagulans GKN316 was also studied. The strain B. coagulans GKN316 could effectively convert these toxic inhibitors to the less toxic corresponding alcohols in situ. These results suggested that B. coagulans GKN316 was well suited to production of lactic acid from undetoxified lignocellulosic hydrolysates. PMID:26863012

  3. Lactic Acid Production from Pretreated Hydrolysates of Corn Stover by a Newly Developed Bacillus coagulans Strain.

    Science.gov (United States)

    Jiang, Ting; Qiao, Hui; Zheng, Zhaojuan; Chu, Qiulu; Li, Xin; Yong, Qiang; Ouyang, Jia

    2016-01-01

    An inhibitor-tolerance strain, Bacillus coagulans GKN316, was developed through atmospheric and room temperature plasma (ARTP) mutation and evolution experiment in condensed dilute-acid hydrolysate (CDH) of corn stover. The fermentabilities of other hydrolysates with B. coagulans GKN316 and the parental strain B. coagulans NL01 were assessed. When using condensed acid-catalyzed steam-exploded hydrolysate (CASEH), condensed acid-catalyzed liquid hot water hydrolysate (CALH) and condensed acid-catalyzed sulfite hydrolysate (CASH) as substrates, the concentration of lactic acid reached 45.39, 16.83, and 18.71 g/L by B. coagulans GKN316, respectively. But for B. coagulans NL01, only CASEH could be directly fermented to produce 15.47 g/L lactic acid. The individual inhibitory effect of furfural, 5-hydroxymethylfurfural (HMF), vanillin, syringaldehyde and p-hydroxybenzaldehyde (pHBal) on xylose utilization by B. coagulans GKN316 was also studied. The strain B. coagulans GKN316 could effectively convert these toxic inhibitors to the less toxic corresponding alcohols in situ. These results suggested that B. coagulans GKN316 was well suited to production of lactic acid from undetoxified lignocellulosic hydrolysates.

  4. Lactic Acid Production from Pretreated Hydrolysates of Corn Stover by a Newly Developed Bacillus coagulans Strain.

    Directory of Open Access Journals (Sweden)

    Ting Jiang

    Full Text Available An inhibitor-tolerance strain, Bacillus coagulans GKN316, was developed through atmospheric and room temperature plasma (ARTP mutation and evolution experiment in condensed dilute-acid hydrolysate (CDH of corn stover. The fermentabilities of other hydrolysates with B. coagulans GKN316 and the parental strain B. coagulans NL01 were assessed. When using condensed acid-catalyzed steam-exploded hydrolysate (CASEH, condensed acid-catalyzed liquid hot water hydrolysate (CALH and condensed acid-catalyzed sulfite hydrolysate (CASH as substrates, the concentration of lactic acid reached 45.39, 16.83, and 18.71 g/L by B. coagulans GKN316, respectively. But for B. coagulans NL01, only CASEH could be directly fermented to produce 15.47 g/L lactic acid. The individual inhibitory effect of furfural, 5-hydroxymethylfurfural (HMF, vanillin, syringaldehyde and p-hydroxybenzaldehyde (pHBal on xylose utilization by B. coagulans GKN316 was also studied. The strain B. coagulans GKN316 could effectively convert these toxic inhibitors to the less toxic corresponding alcohols in situ. These results suggested that B. coagulans GKN316 was well suited to production of lactic acid from undetoxified lignocellulosic hydrolysates.

  5. Lactic Acid Bacteria in Health and Disease

    African Journals Online (AJOL)

    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.

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

    Science.gov (United States)

    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. Study of Lactic Acid Thermal Behavior Using Thermoanalytical Techniques

    Directory of Open Access Journals (Sweden)

    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.

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

    NARCIS (Netherlands)

    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

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

    International Nuclear Information System (INIS)

    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)

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

    Directory of Open Access Journals (Sweden)

    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

  11. Antibacterial Activity of Some Lactic Acid Bacteria Isolated from an Algerian Dairy Product

    Directory of Open Access Journals (Sweden)

    Abdelkader Mezaini

    2009-01-01

    Full Text Available In the present study, the antibacterial effect of 20 lactic acid bacteria isolates from a traditional cheese was investigated. 6 isolates showed antibacterial effect against Gram positive bacteria. Streptococcus thermophilus T2 strain showed the wide inhibitory spectrum against the Gram positive bacteria. Growth and bacteriocin production profiles showed that the maximal bacteriocin production, by S. thermophilus T2 cells, was measured by the end of the late-log phase (90 AU ml−1 with a bacteriocine production rate of 9.3 (AU ml−1 h−1. In addition, our findings showed that the bacteriocin, produced by S. thermophilus T2, was stable over a wide pH range (4–8; this indicates that such bacteriocin may be useful in acidic as well as nonacidic food. This preliminarily work shows the potential application of autochthonous lactic acid bacteria to improve safety of traditional fermented food.

  12. Efficient non-sterilized fermentation of biomass-derived xylose to lactic acid by a thermotolerant Bacillus coagulans NL01.

    Science.gov (United States)

    Ouyang, Jia; Cai, Cong; Chen, Hai; Jiang, Ting; Zheng, Zhaojuan

    2012-12-01

    Xylose is the major pentose and the second most abundant sugar in lignocellulosic feedstock. Its efficient utilization is regarded as a technical barrier to the commercial production of bulk chemicals from lignocellulosic biomass. This work aimed at evaluating the lactic acid production from the biomass-derived xylose using non-sterilized fermentation by Bacillus coagulans NL01. A maximum lactic acid concentration of about 75 g/L was achieved from xylose of 100 g/L after 72 h batch fermentation. Acetic acid and levulinic acid were identified as important inhibitors in xylose fermentation, which markedly reduced lactic acid productivity at 15 and 1.0 g/L, respectively. But low concentrations of formic acid (coagulans NL01, the same preference for glucose, xylose, and arabinose was observed and18.2 g/L lactic acid was obtained after 48 h fermentation. These results proved that B. coagulans NL01 was potentially well-suited for producing lactic acid from underutilized xylose-rich prehydrolysates.

  13. Poly(lactic-co-glycolic) acid drug delivery systems through transdermal pathway: an overview

    OpenAIRE

    Naves, Lucas; Dhand, Chetna; Almeida, Luis; Rajamani, Lakshminarayanan; Ramakrishna, Seeram; Soares, Gra?a

    2017-01-01

    In past few decades, scientists have made tremendous advancement in the field of drug delivery systems (DDS), through transdermal pathway, as the skin represents a ready and large surface area for delivering drugs. Efforts are in progress to design efficient transdermal DDS that support sustained drug release at the targeted area for longer duration in the recommended therapeutic window without producing side-effects. Poly(lactic-co-glycolic acid) (PLGA) is one of the most promising Food and ...

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

    OpenAIRE

    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 ...

  15. Novel bacteriocins from lactic acid bacteria (LAB): various structures and applications

    OpenAIRE

    Perez, Rodney H; Zendo, Takeshi; Sonomoto, Kenji

    2014-01-01

    Bacteriocins are heat-stable ribosomally synthesized antimicrobial peptides produced by various bacteria, including food-grade lactic acid bacteria (LAB). These antimicrobial peptides have huge potential as both food preservatives, and as next-generation antibiotics targeting the multiple-drug resistant pathogens. The increasing number of reports of new bacteriocins with unique properties indicates that there is still a lot to learn about this family of peptide antibiotics. In this review, we...

  16. Plasticized Biodegradable Poly(lactic acid) Based Composites Containing Cellulose in Micro- and Nanosize

    OpenAIRE

    Halász, Katalin; Csóka, Levente

    2013-01-01

    The aim of this work was to study the characteristics of thermal processed poly(lactic acid) composites. Poly(ethylene glycol) (PEG400), microcrystalline cellulose (MCC), and ultrasound-treated microcrystalline cellulose (USMCC) were used in 1, 3, and 5 weight percents to modify the attributes of PLA matrix. The composite films were produced by twin screw extrusion followed by film extrusion. The manufactured PLA-based films were characterized by tensile testing, differential scanning calorim...

  17. Methods and materials for the production of L-lactic acid in yeast

    Science.gov (United States)

    Hause, Ben [Jordan, MN; Rajgarhia, Vineet [Minnetonka, MN; Suominen, Pirkko [Maple Grove, MN

    2009-05-19

    Recombinant yeast are provided having, in one aspect, multiple exogenous LDH genes integrated into the genome, while leaving native PDC genes intact. In a second aspect, recombinant yeast are provided having an exogenous LDH gene integrated into its genome at the locus of a native PDC gene, with deletion of the native PDC gene. The recombinant yeast are useful in fermentation process for producing lactic acid.

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

    Science.gov (United States)

    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.

  19. Co-production of functional exopolysaccharides and lactic acid by Lactobacillus kefiranofaciens originated from fermented milk, kefir.

    Science.gov (United States)

    Cheirsilp, Benjamas; Suksawang, Suwannee; Yeesang, Jarucha; Boonsawang, Piyarat

    2018-01-01

    Kefiran is a functional exopolysaccharide produced by Lactobacillus kefiranofaciens originated from kefir, traditional fermented milk in the Caucasian Mountains, Russia. Kefiran is attractive as thickeners, stabilizers, emulsifiers, gelling agents and also has antimicrobial and antitumor activity. However, the production costs of kefiran are still high mainly due to high cost of carbon and nitrogen sources. This study aimed to produce kefiran and its co-product, lactic acid, from low-cost industrial byproducts. Among the sources tested, whey lactose (at 2% sugar concentration) and spent yeast cells hydrolysate (at 6 g-nitrogen/L) gave the highest kefiran of 480 ± 21 mg/L along with lactic acid of 20.1 ± 0.2 g/L. The combination of these two sources and initial pH were optimized through Response Surface Methodology. With the optimized medium, L. kefiranofaciens produced more kefiran and lactic acid up to 635 ± 7 mg/L and 32.9 ± 0.7 g/L, respectively. When the pH was controlled to alleviate the inhibition from acidic pH, L. kefiranofaciens could consume all sugars and produced kefiran and lactic acid up to 1693 ± 29 mg/L and 87.49 ± 0.23 g/L, respectively. Moreover, the fed-batch fermentation with intermittent adding of whey lactose improved kefiran and lactic acid productions up to 2514 ± 93 mg/L and 135 ± 1.75 g/L, respectively. These results indicate the promising approach to economically produce kefiran and lactic acid from low-cost nutrient sources.

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

    International Nuclear Information System (INIS)

    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. Examination of Lactic Acid Bacteria to Secretion of Bacteriocins

    Directory of Open Access Journals (Sweden)

    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

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

    Science.gov (United States)

    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.

  3. Selection of Lactic Acid Bacteria as Probiotic Candidate for Chicken

    Directory of Open Access Journals (Sweden)

    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.

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

    International Nuclear Information System (INIS)

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

    2001-01-01

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

    Directory of Open Access Journals (Sweden)

    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.

  6. Lactic acid production from acidogenic fermentation of fruit and vegetable wastes.

    Science.gov (United States)

    Wu, Yuanyuan; Ma, Hailing; Zheng, Mingyue; Wang, Kaijun

    2015-09-01

    This work focused on the lactic acid production from acidogenic fermentation of fruit and vegetable wastes treatment. A long term completely stirred tank reactor (CSTR) lasting for 50 days was operated at organic loading rate (OLR) of 11 gVS/(L d) and sludge retention time (SRT) of 3 days with pH controlled at 4.0 (1-24 day) and 5.0 (25-50 day). The results indicated that high amount of approximately 10-20 g/L lactic acid was produced at pH of 4.0 and the fermentation type converted from coexistence of homofermentation and heterofermentation into heterofermentation. At pH of 5.0, the hydrolysis reaction was improved and the total concentration of fermentation products increased up to 29.5 g COD/L. The heterofermentation was maintained, however, bifidus pathway by Bifidobacterium played an important role. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Dominant lactic acid bacteria and their technological properties isolated from the Himalayan ethnic fermented milk products.

    Science.gov (United States)

    Dewan, Sailendra; Tamang, Jyoti Prakash

    2007-10-01

    Ethnic people of the Himalayan regions of India, Nepal, Bhutan and China consume a variety of indigenous fermented milk products made from cows milk as well as yaks milk. These lesser-known ethnic fermented foods are dahi, mohi, chhurpi, somar, philu and shyow. The population of lactic acid bacteria (LAB) ranged from 10(7) to 10(8) cfu/g in these Himalayan milk products. A total of 128 isolates of LAB were isolated from 58 samples of ethnic fermented milk products collected from different places of India, Nepal and Bhutan. Based on phenotypic characterization including API sugar test, the dominant lactic acid bacteria were identified as Lactobacillus bifermentans, Lactobacillus paracasei subsp. pseudoplantarum, Lactobacillus kefir, Lactobacillus hilgardii, Lactobacillus alimentarius, Lactobacillus paracasei subsp. paracasei, Lactobacillus plantarum, Lactococcus lactis subsp. lactis, Lactococcus lactis subsp. cremoris and Enterococcus faecium. LAB produced a wide spectrum of enzymes and showed high galactosidase, leucine-arylamidase and phosphatase activities. They showed antagonistic properties against selected Gram-negative bacteria. None of the strains produced bacteriocin and biogenic amines under the test conditions used. Most strains of LAB coagulated skim milk with a moderate drop in pH. Some strains of LAB showed a high degree of hydrophobicity, suggesting these strains may have useful adhesive potential. This paper is the first report on functional lactic acid bacterial composition in some lesser-known ethnic fermented milk products of the Himalayas.

  8. Ethanol and lactic acid production using sap squeezed from old oil palm trunks felled for replanting.

    Science.gov (United States)

    Kosugi, Akihiko; Tanaka, Ryohei; Magara, Kengo; Murata, Yoshinori; Arai, Takamitsu; Sulaiman, Othman; Hashim, Rokiah; Hamid, Zubaidah Aimi Abdul; Yahya, Mohd Khairul Azri; Yusof, Mohd Nor Mohd; Ibrahim, Wan Asma; Mori, Yutaka

    2010-09-01

    Old oil palm trunks that had been felled for replanting were found to contain large quantities of high glucose content sap. Notably, the sap in the inner part of the trunk accounted for more than 80% of the whole trunk weight. The glucose concentration of the sap from the inner part was 85.2g/L and decreased towards the outer part. Other sugars found in relatively low concentrations were sucrose, fructose, galactose, xylose, and rhamnose. In addition, oil palm sap was found to be rich in various kinds of amino acids, organic acids, minerals and vitamins. Based on these findings, we fermented the sap to produce ethanol using the sake brewing yeast strain, Saccharomyces cerevisiae Kyokai no.7. Ethanol was produced from the sap without the addition of nutrients, at a comparable rate and yield to the reference fermentation on YPD medium with glucose as a carbon source. Likewise, we produced lactic acid, a promising material for bio-plastics, poly-lactate, from the sap using the homolactic acid bacterium Lactobacillus lactis ATCC19435. We confirmed that sugars contained in the sap were readily converted to lactic acid with almost the same efficiency as the reference fermentation on MSR medium with glucose as a substrate. These results indicate that oil palm trunks felled for replanting are a significant resource for the production of fuel ethanol and lactic acid in palm oil-producing countries such as Malaysia and Indonesia. Copyright 2010 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  9. Isolation and identification of lactic acid bacteria from traditional dairy products of Kleibar, Heris and Varzaghan

    Directory of Open Access Journals (Sweden)

    T Narimani

    2013-11-01

    Full Text Available Probiotics are dietary supplements of live microorganisms which when consumed in adequate amounts, can have a beneficial effect on the host. Among all bacteria, lactic acid bacteria are the most common type that has been introduced as probiotics. These bacteria are present in dairy products and produce lactic acid during the fermentation process. The aim of this study was to isolate and identify the probiotics from microbial flora of milk and traditional yogurt in Kaleibar, Heris and Varzaghan areas. In this study, lactic acid bacteria were isolated by culture and identified based on biochemical properties and resistant to stomach acid and bile salts were evaluated. Then, for more accurate identification of the isolates, the 16S rRNA genes of Lactobacilli were amplified with specific primers and the purified PCR product was sent for sequencing. According to our results, 17 strains of Lactobacilli and 6 strains of Enterococci were reported in Kaleibar, Heris and Varzaghan areas which could be a good candidate for further investigation as probiotic.

  10. Probiotic potential of noni juice fermented with lactic acid bacteria and bifidobacteria.

    Science.gov (United States)

    Wang, Chung-Yi; Ng, Chang-Chai; Su, Hsuan; Tzeng, Wen-Sheng; Shyu, Yuan-Tay

    2009-01-01

    The present study assesses the feasibility of noni as a raw substrate for the production of probiotic noni juice by lactic acid bacteria (Lactobacilluscasei and Lactobacillus plantarum) and bifidobacteria (Bifidobacteriumlongum). Changes in pH, acidity, sugar content, cell survival and antioxidant properties during fermentation were monitored. All tested strains grew well on noni juice, reaching nearly 10⁹ colony-forming units/ml after 48 h fermentation. L.casei produced less lactic acid than B.longum and L. plantarum. After 4 weeks of cold storage at 4°C, B.longum and L. plantarum survived under low-pH conditions in fermented noni juice. In contrast, L.casei exhibited no cell viability after 3 weeks. Moreover, noni juice fermented with B.longum had a high antioxidant capacity that did not differ significantly (P <0.05) from that of lactic acid bacteria. Finally, we found that B.longum and L. plantarum are optimal probiotics for fermentation with noni juice.

  11. Compositional characteristics of commercial yoghurt based on quantitative determination of viable lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Niketić Gordana B.

    2009-01-01

    Full Text Available Yoghurt quality is particularly difficult to standardize because of the many forms, varieties, manufacturing methods, ingredients and consumer preferences that exist. Since these factors will always play an important role, it is unlikely that a uniform yoghurt quality concept will ever emerge, such as has been developed for other dairy products. There are a number of common denominators, however that have bearing on yoghurt quality. Since a number of producers are recognized within the broad category entitled yoghurt. This situation makes yoghurt an interesting, challenging, but also a confusing area to work in. The present investigation was undertaken to isolate from commercial yoghurt the strains involved in its manufacture and determine the characteristics of Streptococcus thermophilus and Lactobacillus delbrueckii subsp.bulgaricus. This study is concerned with the lactic acid bacteria (L.delbrueckii subsp. bulgaricus and S. thermophilus growth in yoghurt from involving different procedures and with the determination of the number of lactic acid bacteria in dependence of the temperature and acidity in the period of storage. Predominant samples of yoghurt were with 11-107/ml lactic acid lactococci (44.28%.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  15. CHARACTERIZATION OF AUTOCHTHONUS LACTIC FLORA OF A CAMPANIAN CHILLI CHEESE PRODUCED FROM RAW SHEEP MILK

    Directory of Open Access Journals (Sweden)

    A. Mormile

    2012-08-01

    Full Text Available The natural lactic flora of the artisanal chilli “Tramonti” cheese, a typical product manufactured in the “Lattari mountains”, area of Salerno province (Italy, was investigated. Particular attention was paid to the growth dynamics assessment and to the molecular identification of the indigenous lactic acid bacteria involved in the ripening of this cheese made with raw sheep milk without starter cultures. One batch was monitored taking 4 sample on 0, 30, 50 and 105 ripening days. Lactobacillus and Lactococcus were enumerated and randomly isolated on MRS and LM17 agar (32ºC x 48h -mesophilic flora- and 42°C x 48h -thermophilic flora, respectively. N. 66 presumptive lactic acid bacteria isolates, gram positive and catalase negative, were genotipically identified by Ribotyping. Mesophilic Lactobacillus remained at levels of 107 cfu/g during whole maturation time and thermophilic Lactobacillus, from initial values of 105 cfu/g, reached concentratios of 106 cfu/g at the end of maturation. Mesophilic and thermophilic Lactococcus showed, on average, levels of 106 since the beginning of the ripening. Ribotyping allowed to detect 4 lactic acid bacteria species: Enterococcus faecium (65,15%, Lactococcus lactis spp. cremoris (24,24%, Enterococcus faecalis (6,06% and Enterococcus durans (4,54%, showing the diversity of indigenous lactic acid bacteria of chilli “Tramonti” cheese.

  16. Lactic acid induces aberrant amyloid precursor protein processing by promoting its interaction with endoplasmic reticulum chaperone proteins.

    Directory of Open Access Journals (Sweden)

    Yiwen Xiang

    Full Text Available BACKGROUND: Lactic acid, a natural by-product of glycolysis, is produced at excess levels in response to impaired mitochondrial function, high-energy demand, and low oxygen availability. The enzyme involved in the production of β-amyloid peptide (Aβ of Alzheimer's disease, BACE1, functions optimally at lower pH, which led us to investigate a potential role of lactic acid in the processing of amyloid precursor protein (APP. METHODOLOGY/PRINCIPAL FINDINGS: Lactic acid increased levels of Aβ40 and 42, as measured by ELISA, in culture medium of human neuroblastoma cells (SH-SY5Y, whereas it decreased APP metabolites, such as sAPPα. In cell lysates, APP levels were increased and APP was found to interact with ER-chaperones in a perinuclear region, as determined by co-immunoprecipitation and fluorescence microscopy studies. Lactic acid had only a very modest effect on cellular pH, did increase the levels of ER chaperones Grp78 and Grp94 and led to APP aggregate formation reminiscent of aggresomes. CONCLUSIONS/SIGNIFICANCE: These findings suggest that sustained elevations in lactic acid levels could be a risk factor in amyloidogenesis related to Alzheimer's disease through enhanced APP interaction with ER chaperone proteins and aberrant APP processing leading to increased generation of amyloid peptides and APP aggregates.

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

    Directory of Open Access Journals (Sweden)

    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.

  18. Preparation and Characterization of Films Extruded of Polyethylene/Chitosan Modified with Poly(lactic acid)

    Science.gov (United States)

    Quiroz-Castillo, Jesús Manuel; Rodríguez-Félix, Dora Evelia; Grijalva-Monteverde, Heriberto; Lizárraga-Laborín, Lauren Lucero; Castillo-Ortega, María Mónica; del Castillo-Castro, Teresa; Rodríguez-Félix, Francisco; Herrera-Franco, Pedro Jesús

    2014-01-01

    The use of mixtures of synthetic and natural polymers is a potential option to reduce the pollution by plastic waste. In this work, the method for the chemical modification of chitosan with poly(lactic acid) was developed; then, the preparation of films of blends of polyethylene and chitosan-poly(lactic acid) produced by an extrusion method using polyethylene-graft maleic anhydride as a compatibilizer. It was possible to obtain films with a maximum content of 20 wt% and 30 wt%, chitosan, with and without compatibilizer, respectively. Scanning electron microscope (SEM) analysis showed a homogeneous surface on all films. The addition of the compatibilizer had a significant effect on the mechanical properties of the films, such as an increase in Young’s modulus and a decrease in the elongation at break; additionally, the compatibilizer promotes thermal degradation in a single step and gives the film a slight increase in thermal resistance. These results are attributed to an improved interaction in the interface of polyethylene and chitosan-poly(lactic acid), promoted by the compatibilizer. PMID:28787928

  19. Production of D-lactic acid from sugarcane bagasse using steam-explosion

    Science.gov (United States)

    Sasaki, Chizuru; Okumura, Ryosuke; Asakawa, Ai; Asada, Chikako; Nakamura, Yoshitoshi

    2012-03-01

    This study investigated the production of D-lactic acid from unutilized sugarcane bagasse using steam explosion pretreatment. The optimal steam pressure for a steaming time of 5 min was determined. By enzymatic saccharification using Meicellase, the highest recovery of glucose from raw bagasse, 73.7%, was obtained at a steam pressure of 20 atm. For residue washed with water after steam explosion, the glucose recovery increased up to 94.9% at a steam pressure of 20 atm. These results showed that washing with water is effective in removing enzymatic reaction inhibitors. After steam pretreatment (steam pressure of 20 atm), D-lactic acid was produced by Lactobacillus delbrueckii NBRC 3534 from the enzymatic hydrolyzate of steam-exploded bagasse and washed residue. The conversion rate of D-lactic acid obtained from the initial glucose concentration was 66.6% for the hydrolyzate derived from steam-exploded bagasse and 90.0% for that derived from the washed residue after steam explosion. These results also demonstrated that the hydrolyzate of steam-exploded bagasse (without washing with water) contains fermentation inhibitors and washing with water can remove them.

  20. Preparation and Characterization of Films Extruded of Polyethylene/Chitosan Modified with Poly(lactic acid

    Directory of Open Access Journals (Sweden)

    Jesús Manuel Quiroz-Castillo

    2014-12-01

    Full Text Available The use of mixtures of synthetic and natural polymers is a potential option to reduce the pollution by plastic waste. In this work, the method for the chemical modification of chitosan with poly(lactic acid was developed; then, the preparation of films of blends of polyethylene and chitosan-poly(lactic acid produced by an extrusion method using polyethylene-graft maleic anhydride as a compatibilizer. It was possible to obtain films with a maximum content of 20 wt% and 30 wt%, chitosan, with and without compatibilizer, respectively. Scanning electron microscope (SEM analysis showed a homogeneous surface on all films. The addition of the compatibilizer had a significant effect on the mechanical properties of the films, such as an increase in Young’s modulus and a decrease in the elongation at break; additionally, the compatibilizer promotes thermal degradation in a single step and gives the film a slight increase in thermal resistance. These results are attributed to an improved interaction in the interface of polyethylene and chitosan-poly(lactic acid, promoted by the compatibilizer.

  1. Piezoelectric antibacterial fabric comprised of poly(l-lactic acid) yarn

    Science.gov (United States)

    Ando, Masamichi; Takeshima, Satoshi; Ishiura, Yutaka; Ando, Kanako; Onishi, Osamu

    2017-10-01

    A lactic acid monomer has an asymmetric carbon in the molecule, so there are optical isomer l- and d-type. The most widely used poly(lactic acid) (PLA) for commercial applications is poly(l-lactic acid) (PLLA). PLLA is the polymerization product of l-lactide. Certain treatments of PLLA can yield a film that exhibits shear piezoelectricity. Thus, piezoelectric PLLA fiber can be generated by micro slitting piezoelectric PLLA films or by a melt spinning method. We prepared left-handed helical multi fiber yarn (S-yarn) and right-handed helical yarn (Z-yarn) using piezoelectric PLLA fiber. PLLA exhibited shear mode piezoelectricity, causing the electric polarity of the yarn surface to be reversed on the S-yarn and Z-yarn when tension was applied. An SZ-yarn was produced by combining the S-yarn and Z-yarn, and fabric was prepared using the SZ-yarn. This study demonstrated that the fabric has a strong antibacterial effect, which is thought to be due to the strong electric field between the yarns. The field is generated by a piezoelectric effect when the fabric was extended and contracted.

  2. Lactic acid bacteria in dairy food: surface characterization and interactions with food matrix components.

    Science.gov (United States)

    Burgain, J; Scher, J; Francius, G; Borges, F; Corgneau, M; Revol-Junelles, A M; Cailliez-Grimal, C; Gaiani, C

    2014-11-01

    This review gives an overview of the importance of interactions occurring in dairy matrices between Lactic Acid Bacteria and milk components. Dairy products are important sources of biological active compounds of particular relevance to human health. These compounds include immunoglobulins, whey proteins and peptides, polar lipids, and lactic acid bacteria including probiotics. A better understanding of interactions between bioactive components and their delivery matrix may successfully improve their transport to their target site of action. Pioneering research on probiotic lactic acid bacteria has mainly focused on their host effects. However, very little is known about their interaction with dairy ingredients. Such knowledge could contribute to designing new and more efficient dairy food, and to better understand relationships between milk constituents. The purpose of this review is first to provide an overview of the current knowledge about the biomolecules produced on bacterial surface and the composition of the dairy matter. In order to understand how bacteria interact with dairy molecules, adhesion mechanisms are subsequently reviewed with a special focus on the environmental conditions affecting bacterial adhesion. Methods dedicated to investigate the bacterial surface and to decipher interactions between bacteria and abiotic dairy components are also detailed. Finally, relevant industrial implications of these interactions are presented and discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Production of D-lactic acid from sugarcane bagasse using steam-explosion

    International Nuclear Information System (INIS)

    Sasaki, Chizuru; Okumura, Ryosuke; Asakawa, Ai; Asada, Chikako; Nakamura, Yoshitoshi

    2012-01-01

    This study investigated the production of D-lactic acid from unutilized sugarcane bagasse using steam explosion pretreatment. The optimal steam pressure for a steaming time of 5 min was determined. By enzymatic saccharification using Meicellase, the highest recovery of glucose from raw bagasse, 73.7%, was obtained at a steam pressure of 20 atm. For residue washed with water after steam explosion, the glucose recovery increased up to 94.9% at a steam pressure of 20 atm. These results showed that washing with water is effective in removing enzymatic reaction inhibitors. After steam pretreatment (steam pressure of 20 atm), D-lactic acid was produced by Lactobacillus delbrueckii NBRC 3534 from the enzymatic hydrolyzate of steam-exploded bagasse and washed residue. The conversion rate of D-lactic acid obtained from the initial glucose concentration was 66.6% for the hydrolyzate derived from steam-exploded bagasse and 90.0% for that derived from the washed residue after steam explosion. These results also demonstrated that the hydrolyzate of steam-exploded bagasse (without washing with water) contains fermentation inhibitors and washing with water can remove them.

  4. High titer L-lactic acid production from corn stover with minimum wastewater generation and techno-economic evaluation based on Aspen plus modeling.

    Science.gov (United States)

    Liu, Gang; Sun, Jiaoe; Zhang, Jian; Tu, Yi; Bao, Jie

    2015-12-01

    Technological potentials of l-lactic acid production from corn stover feedstock were investigated by experimental and techno-economic studies. An optimal performance with 104.5 g/L in l-lactic acid titer and 71.5% in overall yield from cellulose in corn stover to l-lactic acid using an engineered Pediococcus acidilactici strain were obtained by overcoming several technical barriers. A rigorous Aspen plus model for l-lactic acid production starting from dry dilute acid pretreated and biodetoxified corn stover was developed. The techno-economic analysis shows that the minimum l-lactic acid selling price (MLSP) was $0.523 per kg, which was close to that of the commercial l-lactic acid produced from starch feedstock, and 24% less expensive than that of ethanol from corn stover, even though the xylose utilization was not considered. The study provided a prototype of industrial application and an evaluation model for high titer l-lactic acid production from lignocellulose feedstock. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  9. Probiotic properties of endemic strains of lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  11. Proteolytic Activity in Reduced-Fat Cheddar Cheese Made with Lactic Acid Bacteria and Camel Chymosin

    DEFF Research Database (Denmark)

    Børsting, Mette Winther

    be the need of an extended ripening period to reach a similar cheese structure as in cheeses produced with BC. The aim of this project was to compensate for the lower proteolytic activity in cheese produced with CC compared to BC. Selection of dairy lactic acid bacteria (LAB) for cheese production with high....... lactis subsp lactis, 10 thermophilic Lactobacillus strains and 15 frozen direct vat set strains of thermopholic Lactobacillus) to hydrolyse αS1-CN, candidates were selected for cheese-making experiments. None of the selected proteolytic strains contributed significantly to softening the cheese structure...

  12. Lactic acid bacteria: inhibition of angiotensin converting enzyme in vitro and in vivo

    DEFF Research Database (Denmark)

    Fuglsang, Anders; Rattray, Fergal; Nilsson, Dan

    2003-01-01

    A total of 26 strains of wild-type lactic acid bacteria, mainly belonging to Lactococcus lactis and Lactobacillus helveticus , were assayed in vitro for their ability to produce a milk fermentate with inhibitory activity towards angiotensin converting enzyme (ACE). It was clear that the test stra...

  13. Insect symbionts as valuable grist for the biotechnological mill: an alkaliphilic silkworm gut bacterium for efficient lactic acid production.

    Science.gov (United States)

    Liang, Xili; Sun, Chao; Chen, Bosheng; Du, Kaiqian; Yu, Ting; Luang-In, Vijitra; Lu, Xingmeng; Shao, Yongqi

    2018-04-07

    Insects constitute the most abundant and diverse animal class and act as hosts to an extraordinary variety of symbiotic microorganisms. These microbes living inside the insects play critical roles in host biology and are also valuable bioresources. Enterococcus mundtii EMB156, isolated from the larval gut (gut pH >10) of the model organism Bombyx mori (Lepidoptera: Bombycidae), efficiently produces lactic acid, an important metabolite for industrial production of bioplastic materials. E. mundtii EMB156 grows well under alkaline conditions and stably converts various carbon sources into lactic acid, offering advantages in downstream fermentative processes. High-yield lactic acid production can be achieved by the strain EMB156 from renewable biomass substrates under alkaline pretreatments. Single-molecule real-time (SMRT) sequencing technology revealed its 3.01 Mbp whole genome sequence. A total of 2956 protein-coding sequences, 65 tRNA genes, and 6 rRNA operons were predicted in the EMB156 chromosome. Remarkable genomic features responsible for lactic acid fermentation included key enzymes involved in the pentose phosphate (PP)/glycolytic pathway, and an alpha amylase and xylose isomerase were characterized in EMB156. This genomic information coincides with the phenotype of E. mundtii EMB156, reflecting its metabolic flexibility in efficient lactate fermentation, and established a foundation for future biotechnological application. Interestingly, enzyme activities of amylase were quite stable in high-pH broths, indicating a possible mechanism for strong EMB156 growth in an alkaline environment, thereby facilitating lactic acid production. Together, these findings implied that valuable lactic acid-producing bacteria can be discovered efficiently by screening under the extremely alkaline conditions, as exemplified by gut microbial symbionts of Lepidoptera insects.

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

    NARCIS (Netherlands)

    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

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

    African Journals Online (AJOL)

    ) 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.

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

    DEFF Research Database (Denmark)

    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...

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

    African Journals Online (AJOL)

    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.

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

    NARCIS (Netherlands)

    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

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

    African Journals Online (AJOL)

    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 ...

  20. Hydrolytic breakdown of lactoferricin by lactic acid bacteria.

    Science.gov (United States)

    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.

  1. Growth of indigenous lactic acid bacteria Lactobacillus plantarum-pentosus T14 and Lactobacillus plantarum-pentosus T35 in kerandang (Canavalia virosa milk and changes of raffinose

    Directory of Open Access Journals (Sweden)

    Rahayu, E. S.

    2013-01-01

    Full Text Available Aims: Kerandang (Canavalia virosa beans are good source of protein, yet predominantly kerandang foods are not widely accepted mainly because of their beany flavour the belief that they cause flatulence. The objectives of this research were to evaluate of viability of lactic acid bacteria from Indonesia indigenous fermented food in kerandang milk and its ability to metabolize indigestible oligossacharide raffinose.Methodology and results: Two strains of Indonesia indigenous lactic acid bacteria (LAB, namely Lactobacillus plantarum-pentosus T14 and Lactobacillus plantarum-pentosus T35 were used for fermentation of kerandang milk. The results showed that all strains of lactic acid bacteria possess the ability to grow and produce of lactic acid in kerandang milk, indicated that total acid (TA increase, pH decrease and their counts of LAB increase during fermentation period (0-24 h. The two strains of lactic acid bacteria were also able to metabolize raffinose into simple sugar (sucrose, glucose, fructose and galactose during fermentation at 37 °C, however the raffinose transformation by L. plantarum-pentosus T14 more ability than L. plantarum-pentosus T35. The metabolism of raffinose during fermentation by L. plantarum-pentosus T14 and L. plantarum-pentosus T35 were 98.23% and 48.98%, respectively.Conclusion, significance and impact of study: Kerandang milk fermented by lactic acid bacteria can decrease of saccharide raffinose cause of flatulence. Thus, lactic fermented of kerandang milk be safer for consumption.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. Influence of polysorbate 80 and cyclopropane fatty acid synthase activity on lactic acid production by Lactobacillus casei ATCC 334 at low pH.

    Science.gov (United States)

    Broadbent, J R; Oberg, T S; Hughes, J E; Ward, R E; Brighton, C; Welker, D L; Steele, J L

    2014-03-01

    Lactic acid is an important industrial chemical commonly produced through microbial fermentation. The efficiency of acid extraction is increased at or below the acid's pKa (pH 3.86), so there is interest in factors that allow for a reduced fermentation pH. We explored the role of cyclopropane synthase (Cfa) and polysorbate (Tween) 80 on acid production and membrane lipid composition in Lactobacillus casei ATCC 334 at low pH. Cells from wild-type and an ATCC 334 cfa knockout mutant were incubated in APT broth medium containing 3 % glucose plus 0.02 or 0.2 % Tween 80. The cultures were allowed to acidify the medium until it reached a target pH (4.5, 4.0, or 3.8), and then the pH was maintained by automatic addition of NH₄OH. Cells were collected at the midpoint of the fermentation for membrane lipid analysis, and media samples were analyzed for lactic and acetic acids when acid production had ceased. There were no significant differences in the quantity of lactic acid produced at different pH values by wild-type or mutant cells grown in APT, but the rate of acid production was reduced as pH declined. APT supplementation with 0.2 % Tween 80 significantly increased the amount of lactic acid produced by wild-type cells at pH 3.8, and the rate of acid production was modestly improved. This effect was not observed with the cfa mutant, which indicated Cfa activity and Tween 80 supplementation were each involved in the significant increase in lactic acid yield observed with wild-type L. casei at pH 3.8.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  7. 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

    OpenAIRE

    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, ...

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

    OpenAIRE

    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...

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

    Science.gov (United States)

    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. Exploitation of grape marc as functional substrate for lactic acid bacteria and bifidobacteria growth and enhanced antioxidant activity.

    Science.gov (United States)

    Campanella, Daniela; Rizzello, Carlo Giuseppe; Fasciano, Cristina; Gambacorta, Giuseppe; Pinto, Daniela; Marzani, Barbara; Scarano, Nicola; De Angelis, Maria; Gobbetti, Marco

    2017-08-01

    This study aimed at using grape marc for the growth of lactic acid bacteria and bifidobacteria with the perspective of producing a functional ingredient having antioxidant activity. Lactobacillus plantarum 12A and PU1, Lactobacillus paracasei 14A, and Bifidobacterium breve 15A showed the ability to grow on grape marc (GM) based media. The highest bacterial cell density (>9.0 CFU/g) was found in GM added of 1% of glucose (GMG). Compared to un-inoculated and incubated control fermented GMG showed a decrease of carbohydrates and citric acid together with an increase of lactic acid. The content of several free amino acids and phenol compounds differed between samples. Based on the survival under simulated gastro-intestinal conditions, GMG was a suitable carrier of lactic acid bacteria and bifidobacteria strains. Compared to the control, cell-free supernatant (CFS) of fermented GMG exhibited a marked antioxidant activity in vitro. The increased antioxidant activity was confirmed using Caco-2 cell line after inducing oxidative stress, and determining cell viability and radical scavenging activity through MTT and DCFH-DA assays, respectively. Supporting these founding, the SOD-2 gene expression of Caco-2 cells also showed a lowest pro-oxidant effect induced by the four CFS of GMG fermented by lactic acid bacteria and bifidobacteria. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    NARCIS (Netherlands)

    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

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

    NARCIS (Netherlands)

    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

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

    Directory of Open Access Journals (Sweden)

    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

    DEFF Research Database (Denmark)

    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.

    Science.gov (United States)

    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. Current taxonomy of phages infecting lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    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.

  17. Phytase-active lactic acid bacteria from sourdoughs

    DEFF Research Database (Denmark)

    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...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  20. Identification of lactic acid bacteria isolated from Tarhana, a traditional Turkish fermented food

    DEFF Research Database (Denmark)

    Sengun, Ilkin Yucel; Nielsen, Dennis Sandris; Karapinar, Mehmet

    2009-01-01

    Tarhana is a traditional fermented product produced from a mixture of spontaneously fermented yogurt and wheat flour in Turkey. The aims of the present study were to enumerate and identify for the first time by molecular biology-based methods predominant lactic acid bacteria (LAB) isolated during...... processing of Tarhana. Samples were collected from eight different regions of Turkey. In order to explore the relationship between raw material and the microbiology of Tarhana, yogurt and wheat flour were also analyzed. A total of 226 Gram-positive and catalase-negative isolates were obtained from MRS, M17...... and S. thermophilus was found to be the yogurt....

  1. Plasticized Biodegradable Poly(lactic acid Based Composites Containing Cellulose in Micro- and Nanosize

    Directory of Open Access Journals (Sweden)

    Katalin Halász

    2013-01-01

    Full Text Available The aim of this work was to study the characteristics of thermal processed poly(lactic acid composites. Poly(ethylene glycol (PEG400, microcrystalline cellulose (MCC, and ultrasound-treated microcrystalline cellulose (USMCC were used in 1, 3, and 5 weight percents to modify the attributes of PLA matrix. The composite films were produced by twin screw extrusion followed by film extrusion. The manufactured PLA-based films were characterized by tensile testing, differential scanning calorimetry (DSC, scanning electron microscopy (SEM, wide angle X-ray diffraction (WAXD, and degradation test.

  2. Biodiversity of lactic acid bacteria in Moroccan soft white cheese (Jben).

    Science.gov (United States)

    Ouadghiri, Mouna; Amar, Mohamed; Vancanneyt, Marc; Swings, Jean

    2005-10-15

    The bacterial diversity occurring in traditional Moroccan soft white cheese, produced in eight different regions in Morocco, was studied. A total of 164 lactic acid bacteria were isolated, purified and identified by whole-cell protein fingerprinting and rep-PCR genomic fingerprinting. The majority of the strains belonged to the genera Lactobacillus, Lactococcus, Leuconostoc and Enterococcus. Sixteen species were identified: Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacillus paracasei, Lactobacillus brevis, Lactobacillus buchneri, Lactococcus lactis, Lactococcus garvieae, Lactococcus raffinolactis, Leuconostoc pseudomesenteroides, Leuconostoc mesenteroides, Leuconostoc citreum, Eterococcus durans, Enterococcus faecalis, Enterococcus faecium, Enterococcus saccharominimus and Streptococcus sp.

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

    Science.gov (United States)

    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.

  4. Vanillin production from simple phenols by wine-associated lactic acid bacteria.

    Science.gov (United States)

    Bloem, A; Bertrand, A; Lonvaud-Funel, A; de Revel, G

    2007-01-01

    The ability of lactic acid bacteria (LAB) to metabolize certain phenolic precursors to vanillin was investigated. Gas chromatography-mass spectrometry (GC-MS) or HPLC was used to evaluate the biosynthesis of vanillin from simple phenolic precursors. LAB were not able to form vanillin from eugenol, isoeugenol or vanillic acid. However Oenococcus oeni or Lactobacillus sp. could convert ferulic acid to vanillin, but in low yield. Only Lactobacillus sp. or Pediococcus sp. strains were able to produce significant quantities of 4-vinylguaiacol from ferulic acid. Moreover, LAB reduced vanillin to the corresponding vanillyl alcohol. The transformation of phenolic compounds tested by LAB could not explain the concentrations of vanillin observed during LAB growth in contact with wood. Important details of the role of LAB in the conversion of phenolic compounds to vanillin have been elucidated. These findings contribute to the understanding of malolactic fermentation in the production of aroma compounds.

  5. Characteristics of lactic acid bacteria isolates and their effect on silage fermentation of fruit residues.

    Science.gov (United States)

    Yang, Jinsong; Tan, Haisheng; Cai, Yimin

    2016-07-01

    The natural lactic acid bacteria (LAB) population, chemical composition, and silage fermentation of fruit residues were studied. Eighty-two strains of LAB were isolated from fruit residues such as banana leaf and stem, pineapple peel, and papaya peel. All strains were gram-positive and catalase-negative bacteria, and they were divided into 7 groups (A-G) according to morphological and biochemical characters. Strains in groups A to F were rods, and group G was cocci. Group F produced gas from glucose; other groups did not. Groups A to C and F formed dl-lactic acid, whereas groups D, E, and G formed l-lactic acid. Based on the 16S rRNA gene sequence and DNA-DNA hybridization analysis, groups A to G strains were identified as Lactobacillus plantarum (54.9% of the total isolates), Lactobacillus paraplantarum (3.6%), Lactobacillus nagelii (8.5%), Lactobacillus perolens (4.9%), Lactobacillus casei (11.0%), Lactobacillus fermentum (9.8%), and Enterococcus gallinarum (7.3%), respectively. Lactobacillus plantarum and Lactobacillus casei are the most frequently isolated from fruit residues as a dominant species, and they could grow at a lower pH conditions and produce more lactic acid than other isolates. Pineapple and papaya peels contained higher crude protein (11.5-13.8%) and water-soluble carbohydrate (16.8-22.4%), but lower acid detergent fiber contents (21.2 to 26.4%) than banana stems and leaves (8.2% crude protein, 42.8% acid detergent fiber, and 5.1% water-soluble carbohydrate). Compared with banana stem and leaf silages, the pineapple and papaya peel silages were well preserved with a lower pH and higher lactate content. The study suggests that the fruit residues contain excellent LAB species and abundant feed nutrients, and that they can be preserved as silage to be potential food resources for livestock. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  8. Optimization of Preparation Techniques for Poly(Lactic Acid-Co-Glycolic Acid) Nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Birnbaum, Duane T.; Kosmala, Jacqueline D.; Brannon-Peppas, Lisa [Biogel Technology, Inc. (United States)], E-mail: lisabp@biogeltech.com

    2000-06-15

    Microparticles and nanoparticles of poly(lactic acid-co-glycolic acid) (PLAGA) are excellent candidates for the controlled release of many pharmaceutical compounds because of their biodegradable nature. The preparation of submicron PLAGA particles poses serious challenges that are not necessarily present when preparing microparticles. We have evaluated several combinations of organic solvents and surfactants used in the formulation of PLAGA nanoparticles. Critical factors such as the ability to separate the nanoparticles from the surfactant, the ability to re-suspend the nanoparticles after freeze-drying, formulation yield and nanoparticle size were studied. The smallest particles were obtained using the surfactant/solvent combination of sodium dodecyl sulfate and ethyl acetate (65 nm) and the largest particles were obtained using poly(vinyl alcohol) and dichloromethane (466 nm). However, the optimal nanoparticles were produced using either acetone or ethyl acetate as the organic solvent and poly(vinyl alcohol) or human serum albumin as the surfactant. This is because the most critical measure of performance of these nanoparticles proved to be their ability to re-suspend after freeze-drying.

  9. Optimization of Preparation Techniques for Poly(Lactic Acid-Co-Glycolic Acid) Nanoparticles

    International Nuclear Information System (INIS)

    Birnbaum, Duane T.; Kosmala, Jacqueline D.; Brannon-Peppas, Lisa

    2000-01-01

    Microparticles and nanoparticles of poly(lactic acid-co-glycolic acid) (PLAGA) are excellent candidates for the controlled release of many pharmaceutical compounds because of their biodegradable nature. The preparation of submicron PLAGA particles poses serious challenges that are not necessarily present when preparing microparticles. We have evaluated several combinations of organic solvents and surfactants used in the formulation of PLAGA nanoparticles. Critical factors such as the ability to separate the nanoparticles from the surfactant, the ability to re-suspend the nanoparticles after freeze-drying, formulation yield and nanoparticle size were studied. The smallest particles were obtained using the surfactant/solvent combination of sodium dodecyl sulfate and ethyl acetate (65 nm) and the largest particles were obtained using poly(vinyl alcohol) and dichloromethane (466 nm). However, the optimal nanoparticles were produced using either acetone or ethyl acetate as the organic solvent and poly(vinyl alcohol) or human serum albumin as the surfactant. This is because the most critical measure of performance of these nanoparticles proved to be their ability to re-suspend after freeze-drying

  10. Optimization of Preparation Techniques for Poly(Lactic Acid-Co-Glycolic Acid) Nanoparticles

    Science.gov (United States)

    Birnbaum, Duane T.; Kosmala, Jacqueline D.; Brannon-Peppas, Lisa

    2000-06-01

    Microparticles and nanoparticles of poly(lactic acid-co-glycolic acid) (PLAGA) are excellent candidates for the controlled release of many pharmaceutical compounds because of their biodegradable nature. The preparation of submicron PLAGA particles poses serious challenges that are not necessarily present when preparing microparticles. We have evaluated several combinations of organic solvents and surfactants used in the formulation of PLAGA nanoparticles. Critical factors such as the ability to separate the nanoparticles from the surfactant, the ability to re-suspend the nanoparticles after freeze-drying, formulation yield and nanoparticle size were studied. The smallest particles were obtained using the surfactant/solvent combination of sodium dodecyl sulfate and ethyl acetate (65 nm) and the largest particles were obtained using poly(vinyl alcohol) and dichloromethane (466 nm). However, the optimal nanoparticles were produced using either acetone or ethyl acetate as the organic solvent and poly(vinyl alcohol) or human serum albumin as the surfactant. This is because the most critical measure of performance of these nanoparticles proved to be their ability to re-suspend after freeze-drying.

  11. Gamma-aminobutyric acid fermentation with date residue by a lactic acid bacterium, Lactobacillus brevis.

    Science.gov (United States)

    Hasegawa, Momoko; Yamane, Daisuke; Funato, Kouichi; Yoshida, Atsushi; Sambongi, Yoshihiro

    2018-03-01

    Dates are commercially consumed as semi-dried fruit or processed into juice and puree for further food production. However, the date residue after juice and puree production is not used, although it appears to be nutrient enriched. Here, date residue was fermented by a lactic acid bacterium, Lactobacillus brevis, which has been generally recognized as safe. Through degradation of sodium glutamate added to the residue during the fermentation, γ-aminobutyric acid (GABA), which reduces neuronal excitability, was produced at the conversion rate of 80-90% from glutamate. In order to achieve this GABA production level, pretreatment of the date residue with carbohydrate-degrading enzymes, i.e., cellulase and pectinase, was necessary. All ingredients used for this GABA fermentation were known as being edible. These results provide us with a solution for the increasing commercial demand for GABA in food industry with the use of date residue that has been often discarded. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    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

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

    OpenAIRE

    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,...

  14. Antimicrobial effect of selected lactic acid bacteria against microorganisms with decarboxylase activity

    Directory of Open Access Journals (Sweden)

    Khatantuul Purevdorj

    2017-01-01

    Full Text Available The main purpose of this study was to evaluate the antimicrobial activity of twenty-one bacteriocinogenic lactic acid bacteria (12 strains of Lactococcus lactis subsp. lactis, 4 strains of Lactobacillus gasseri, 3 strains of Lb. helveticus and 2 strains of Lb. acidophilus, LAB against 28 Staphylococcus and 33 Enterococcus strains able to produce tyramine, putrescine, 2-phenylethylamine and cadaverine. The antimicrobial activity of cell-free supernatants (CFS from tested LAB was examined by an agar-well diffusion assay. Nine out of twenty-one strains (33% showed the inhibitory effect on tested enterococci and staphylococci, namely 9 strains of Lactococcus lactis subsp. lactis. The diameters of inhibition zones ranged between 7 mm and 14 mm. The biggest diameter of 14 mm inhibition was obtained with the CFS's from strains CCDM 670 and CCDM 731 on Enterococcus sp. E16 and E28. The cell-free supernatants from Lactococcus lactis subsp. lactis CCDM 71 and from Lactococcus lactis subsp. lactis CCDM 731 displayed the broadest antibacterial activity (52% inhibition of all tested strains. On the other hand, the cell-free supernatants from the screened Lactobacillus strains did not show any inhibitory effect on the tested Staphylococcus and Enterococcus strains. Nowadays, the great attention is given to the antibacterial substances produced by lactic acid bacteria. With the ability to produce a variety of metabolites displaying inhibitory effect, the LAB have great potential in biopreservation of food.

  15. Lipoquinones of some spore-forming rods, lactic-acid bacteria and actinomycetes.

    Science.gov (United States)

    Hess, A; Holländer, R; Mannheim, W

    1979-11-01

    The respiratory quinones of 73 strains of Gram-positive bacteria including spore-forming rods, lactic-acid bacteria and actinomyctes were examined. Menaquinones with seven isoprenoid units (MK-7) were the main quinone type found in representatives of the genus Bacillus and in Sporolactobacillus inulinus. However, a strain of B. thuringiensis produced MK-8 in addition to MK-7, and strains of B. lentus and B. pantothenticus appeared to produce MK-9 and MK-8, respectively, with no MK-7. In the clostridia and lactic-acid bacteria, no quinones were found, except in Pediococcus cerevisiae NCTC 8066 and Lactobacillus casei subsp. rhamnosus ATCC 7469, which contained menaquinones, and Streptococcus faecalis NCTC 775 and HIM 478-1, which contained demethylmenaquinones, in relatively low concentrations. Menaquinones were also found in the actinomycetes (except Actinomyces odontolyticus and Bifidobacterium bifidum which did not produce any quinones) and in Protaminobacter alboflavus ATCC 8458, the so-called Actinobacillus actinoides ATCC 15900 and Noguchia granulosis NCTC 10559.

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

    OpenAIRE

    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...

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

    International Nuclear Information System (INIS)

    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)

  18. Fatty acid-producing hosts

    Science.gov (United States)

    Pfleger, Brian F; Lennen, Rebecca M

    2013-12-31

    Described are hosts for overproducing a fatty acid product such as a fatty acid. The hosts include an exogenous nucleic acid encoding a thioesterase and, optionally, an exogenous nucleic acid encoding an acetyl-CoA carboxylase, wherein an acyl-CoA synthetase in the hosts are functionally delected. The hosts prefereably include the nucleic acid encoding the thioesterase at an intermediate copy number. The hosts are preferably recominantly stable and growth-competent at 37.degree. C. Methods of producing a fatty acid product comprising culturing such hosts at 37.degree. C. are also described.

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

    Science.gov (United States)

    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.

  20. Laboratory Studies of Aedes aegypti Attraction to Ketones, Sulfides, and Primary Chloroalkanes Tested Alone and in Combination with L-Lactic Acid.

    Science.gov (United States)

    Bernier, Ulrich R; Kline, Daniel L; Allan, Sandra A; Barnard, Donald R

    2015-03-01

    The attraction of female Aedes aegypti to single compounds and binary compositions containing L-lactic acid and an additional saturated compound from a set of ketones, sulfides, and chloroalkanes was studied using a triple-cage dual-port olfactometer. These chemical classes were studied because of their structural relation to acetone, dimethyl disulfide, and dichloromethane, which have all been reported to synergize attraction to L-lactic acid. Human odors, carbon dioxide, and the binary mixture of L-lactic acid and CO₂served as controls for comparison of attraction responses produced by the binary mixtures. All tested mixtures that contained chloroalkanes attracted mosquitoes at synergistic levels, as did L-lactic acid and CO₂. Synergism was less frequent in mixtures of L-lactic acid with sulfides and ketones; in the case of ketones, synergistic attraction was observed only for L-lactic acid combined with acetone or butanone. Suppression or inhibition of attraction response was observed for combinations that contained ketones of C7-C12 molecular chain length (optimum in the C8-C10 range). This inhibition effect is similar to that observed previously for specific ranges of carboxylic acids, aldehydes, and alcohols.

  1. Valorization of Agri-Food Waste via Fermentation: Production of l-lactic Acid as a Building Block for the Synthesis of Biopolymers

    Directory of Open Access Journals (Sweden)

    Giovanni Dedenaro

    2016-11-01

    Full Text Available Global interest towards lactic acid production has recently significantly increased because lactic acid can be used as raw material for the production of polylactic acid (PLA, a polymer used in biodegradable plastics for its special, environmentally-friendly properties. However, the high production costs have hindered the large-scale application of PLA due to the high price of lactic acid. Here we evaluated the potential of pear pomace and ricotta cheese whey (RCW as a low-cost source of nutrients for lactic acid fermentation of Lactobacillus casei and Lactobacillus farciminis in microaerophilic conditions and mild sterility. After an initial lab-scale screening of 19 lactic acid bacteria (LAB strains to select the highest producer of lactic acid, we reported the 1L-batch scale-up to test process efficiency and productivity of the most promising LAB strains. Batch fermentation of a 25:75 mixture of pear pomace and RCW, respectively, reached an overall yield factor of 90% and a volumetric productivity of 0.42 g/L·h.

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

    Science.gov (United States)

    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.

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

    African Journals Online (AJOL)

    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 ...

  4. Canonical Analysis Technique as an Approach to Determine Optimal Conditions for Lactic Acid Production by Lactobacillus helveticus ATCC 15009

    Directory of Open Access Journals (Sweden)

    Marcelo Teixeira Leite

    2012-01-01

    Full Text Available The response surface methodology and canonical analysis were employed to find the most suitable conditions for Lactobacillus helveticus to produce lactic acid from cheese whey in batch fermentation. The analyzed variables were temperature, pH, and the concentrations of lactose and yeast extract. The experiments were carried out according to a central composite design with three center points. An empiric equation that correlated the concentration of lactic acid with the independent variables was proposed. The optimal conditions determined by the canonical analysis of the fitted model were 40°C, pH 6.8, 82 g/L of lactose, and 23.36 g/L of yeast extract. At this point, the lactic acid concentration reached 59.38 g/L. A subsequent fermentation, carried out under optimal conditions, confirmed the product concentration predicted by the adjusted model. This concentration of lactic acid is the highest ever reported for Lactobacillus helveticus ATCC 15009 in batch process using cheese whey as substrate.

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

    Science.gov (United States)

    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.

  6. Biodegradation of flax fiber reinforced poly lactic acid

    Directory of Open Access Journals (Sweden)

    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.

  7. Transcriptional Response to Lactic Acid Stress in the Hybrid Yeast Zygosaccharomyces parabailii.

    Science.gov (United States)

    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

  8. The sensitivity and significance analysis of parameters in the model of pH regulation on lactic acid production by Lactobacillus bulgaricus.

    Science.gov (United States)

    Liu, Ke; Zeng, Xiangmiao; Qiao, Lei; Li, Xisheng; Yang, Yubo; Dai, Cuihong; Hou, Aiju; Xu, Dechang

    2014-01-01

    The excessive production of lactic acid by L. bulgaricus during yogurt storage is a phenomenon we are always tried to prevent. The methods used in industry either control the post-acidification inefficiently or kill the probiotics in yogurt. Genetic methods of changing the activity of one enzyme related to lactic acid metabolism make the bacteria short of energy to growth, although they are efficient ways in controlling lactic acid production. A model of pH-induced promoter regulation on the production of lactic acid by L. bulgaricus was built. The modelled lactic acid metabolism without pH-induced promoter regulation fitted well with wild type L. bulgaricus (R2LAC = 0.943, R2LA = 0.942). Both the local sensitivity analysis and Sobol sensitivity analysis indicated parameters Tmax, GR, KLR, S, V0, V1 and dLR were sensitive. In order to guide the future biology experiments, three adjustable parameters, KLR, V0 and V1, were chosen for further simulations. V0 had little effect on lactic acid production if the pH-induced promoter could be well induced when pH decreased to its threshold. KLR and V1 both exhibited great influence on the producing of lactic acid. The proposed method of introducing a pH-induced promoter to regulate a repressor gene could restrain the synthesis of lactic acid if an appropriate strength of promoter and/or an appropriate strength of ribosome binding sequence (RBS) in lacR gene has been designed.

  9. L-lactic acid production from starch by simultaneous saccharification and fermentation in a genetically engineered Aspergillus oryzae pure culture.

    Science.gov (United States)

    Wakai, Satoshi; Yoshie, Toshihide; Asai-Nakashima, Nanami; Yamada, Ryosuke; Ogino, Chiaki; Tsutsumi, Hiroko; Hata, Yoji; Kondo, Akihiko

    2014-12-01

    Lactic acid is a commodity chemical that can be produced biologically. Lactic acid-producing Aspergillus oryzae strains were constructed by genetic engineering. The A. oryzae LDH strain with the bovine L-lactate dehydrogenase gene produced 38 g/L of lactate from 100g/L of glucose. Disruption of the wild-type lactate dehydrogenase gene in A. oryzae LDH improved lactate production. The resulting strain A. oryzae LDHΔ871 produced 49 g/L of lactate from 100g/L of glucose. Because A. oryzae strains innately secrete amylases, A. oryzae LDHΔ871 produced approximately 30 g/L of lactate from various starches, dextrin, or maltose (all at 100 g/L). To our knowledge, this is the first report describing the simultaneous saccharification and fermentation of lactate from starch using a pure culture of transgenic A. oryzae. Our results indicate that A. oryzae could be a promising host for the bioproduction of useful compounds such as lactic acid. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

    African Journals Online (AJOL)

    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 ...

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

    CSIR Research Space (South Africa)

    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...

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

    African Journals Online (AJOL)

    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.

  13. A study on the effect of parameters on lactic acid production from whey

    Directory of Open Access Journals (Sweden)

    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.

  14. Lactic Acid Bacteria from Kefir Increase Cytotoxicity of Natural Killer Cells to Tumor Cells.

    Science.gov (United States)

    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.

  15. Lactic Acid Bacteria from Kefir Increase Cytotoxicity of Natural Killer Cells to Tumor Cells

    Directory of Open Access Journals (Sweden)

    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.

  16. Mutually stimulating interactions between lactic acid bacteria and Saccharomyces cerevisiae in sourdough fermentation

    NARCIS (Netherlands)

    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.

  17. Kinetics of free radical decay reactions in lactic acid homo and copolymers irradiated to sterilization dose

    International Nuclear Information System (INIS)

    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)

  18. Lactic acid alleviates stress: good for female genital tract homeostasis, bad for protection against malignancy.

    Science.gov (United States)

    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.

  19. Some features of transplutonium and rare earth elements extraction by HDEHP from lactic acid solutions

    International Nuclear Information System (INIS)

    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

  20. Optimisation of lactic acid fermentation for improved vinegar flavour during rosy vinegar brewing.

    Science.gov (United States)

    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.

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

    OpenAIRE

    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...

  2. Production of lactic acid from corn cobs through fermentation lactobacillus delbruekii

    International Nuclear Information System (INIS)

    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)

  3. Inhibitory Properties of Lactic Acid Bacteria against Moulds Associated with Spoilage of Bakery Products

    OpenAIRE

    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...

  4. Lactic Acid Bacteria from Kefir Increase Cytotoxicity of Natural Killer Cells to Tumor Cells

    OpenAIRE

    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...

  5. Diversity and distribution of culturable lactic acid bacterial species in Indonesian Sayur Asin

    OpenAIRE

    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...

  6. Antioxidant activity of probiotic lactic acid bacteria isolated from Mongolian airag

    OpenAIRE

    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...

  7. Fabrication and characterization of novel multilayered structures by stereocomplexion of poly(D-lactic acid)/poly(L-lactic acid) and self-assembly of polyelectrolytes

    OpenAIRE

    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...

  8. Carrot Juice Fermentations as Man-Made Microbial Ecosystems Dominated by Lactic Acid Bacteria.

    Science.gov (United States)

    Wuyts, Sander; Van Beeck, Wannes; Oerlemans, Eline F M; Wittouck, Stijn; Claes, Ingmar J J; De Boeck, Ilke; Weckx, Stefan; Lievens, Bart; De Vuyst, Luc; Lebeer, Sarah

    2018-06-15

    Spontaneous vegetable fermentations, with their rich flavors and postulated health benefits, are regaining popularity. However, their microbiology is still poorly understood, therefore raising concerns about food safety. In addition, such spontaneous fermentations form interesting cases of man-made microbial ecosystems. Here, samples from 38 carrot juice fermentations were collected through a citizen science initiative, in addition to three laboratory fermentations. Culturing showed that Enterobacteriaceae were outcompeted by lactic acid bacteria (LAB) between 3 and 13 days of fermentation. Metabolite-target analysis showed that lactic acid and mannitol were highly produced, as well as the biogenic amine cadaverine. High-throughput 16S rRNA gene sequencing revealed that mainly species of Leuconostoc and Lactobacillus (as identified by 8 and 20 amplicon sequence variants [ASVs], respectively) mediated the fermentations in subsequent order. The analyses at the DNA level still detected a high number of Enterobacteriaceae , but their relative abundance was low when RNA-based sequencing was performed to detect presumptive metabolically active bacterial cells. In addition, this method greatly reduced host read contamination. Phylogenetic placement indicated a high LAB diversity, with ASVs from nine different phylogenetic groups of the Lactobacillus genus complex. However, fermentation experiments with isolates showed that only strains belonging to the most prevalent phylogenetic groups preserved the fermentation dynamics. The carrot juice fermentation thus forms a robust man-made microbial ecosystem suitable for studies on LAB diversity and niche specificity. IMPORTANCE The usage of fermented food products by professional chefs is steadily growing worldwide. Meanwhile, this interest has also increased at the household level. However, many of these artisanal food products remain understudied. Here, an extensive microbial analysis was performed of spontaneous fermented

  9. Development of a new lactic acid bacterial inoculant for fresh rice straw silage

    Directory of Open Access Journals (Sweden)

    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.

  10. Major Role of NAD-Dependent Lactate Dehydrogenases in the Production of l-Lactic Acid with High Optical Purity by the Thermophile Bacillus coagulans.

    Science.gov (United States)

    Wang, Limin; Cai, Yumeng; Zhu, Lingfeng; Guo, Honglian; Yu, Bo

    2014-12-01

    Bacillus coagulans 2-6 is an excellent producer of optically pure l-lactic acid. However, little is known about the mechanism of synthesis of the highly optically pure l-lactic acid produced by this strain. Three enzymes responsible for lactic acid production-NAD-dependent l-lactate dehydrogenase (l-nLDH; encoded by ldhL), NAD-dependent d-lactate dehydrogenase (d-nLDH; encoded by ldhD), and glycolate oxidase (GOX)-were systematically investigated in order to study the relationship between these enzymes and the optical purity of lactic acid. Lactobacillus delbrueckii subsp. bulgaricus DSM 20081 (a d-lactic acid producer) and Lactobacillus plantarum subsp. plantarum DSM 20174 (a dl-lactic acid producer) were also examined in this study as comparative strains, in addition to B. coagulans. The specific activities of key enzymes for lactic acid production in the three strains were characterized in vivo and in vitro, and the levels of transcription of the ldhL, ldhD, and GOX genes during fermentation were also analyzed. The catalytic activities of l-nLDH and d-nLDH were different in l-, d-, and dl-lactic acid producers. Only l-nLDH activity was detected in B. coagulans 2-6 under native conditions, and the level of transcription of ldhL in B. coagulans 2-6 was much higher than that of ldhD or the GOX gene at all growth phases. However, for the two Lactobacillus strains used in this study, ldhD transcription levels were higher than those of ldhL. The high catalytic efficiency of l-nLDH toward pyruvate and the high transcription ratios of ldhL to ldhD and ldhL to the GOX gene provide the key explanations for the high optical purity of l-lactic acid produced by B. coagulans 2-6. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  11. Characterization of the spoilage lactic acid bacteria in “sliced vacuum-packed cooked ham”

    Science.gov (United States)

    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

  12. Laboratory evaluation of lactic acid on attraction of Culex spp. (Diptera: Culicidae).

    Science.gov (United States)

    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.

  13. Enhancement of L(+)-Lactic Acid Production of Immobilized Rhizopus Oryzae Implanted by Ion Beams

    International Nuclear Information System (INIS)

    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.

  14. CHARACTERIZATION OF LACTIC ACID BACTERIA ISOLATED FROM SUMBAWA MARE MILK

    Directory of Open Access Journals (Sweden)

    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.

  15. Optimization of β-galactosidase production from lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    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.

  16. Poly (lactic acid organoclay nano composites for paper coating applications

    Directory of Open Access Journals (Sweden)

    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.

  17. Lactic acid bacteria in dried vegetables and spices.

    Science.gov (United States)

    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.

  18. Degradation of Poly (lactic acid under Simulated Landfill Conditions

    Directory of Open Access Journals (Sweden)

    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.

  19. Adhesion Properties of Lactic Acid Bacteria on Intestinal Mucin

    Directory of Open Access Journals (Sweden)

    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.

  20. Separation of viable lactic acid bacteria from fermented milk

    Directory of Open Access Journals (Sweden)

    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

  1. Modification of azo dyes by lactic acid bacteria.

    Science.gov (United States)

    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.

  2. Concurrent Lactic and Volatile Fatty Acid Analysis of Microbial Fermentation Samples by Gas Chromatography with Heat Pre-treatment.

    Science.gov (United States)

    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.

  3. Efficient Production of Lactic Acid from Sweet Sorghum Juice by a Newly Isolated Lactobacillus salivarius CGMCC 7.75.

    Science.gov (United States)

    Liu, Quanlan; Wang, Shanglong; Zhi, Jian-Fei; Ming, Henglei; Teng, Dawei

    2013-09-01

    Sweet sorghum juice was a cheap and renewable resource, and also a potential carbon source for the fermentation production of lactic acid (LA) by a lactic acid bacterium. One newly isolated strain Lactobacillus salivarius CGMCC 7.75 showed the ability to produce the highest yield and optical purity of LA from sweet sorghum juice. Studies of feeding different concentrations of sweet sorghum juice and nitrogen source suggested the optimal concentrations of fermentation were 325 ml l(-1) and 20 g l(-1), respectively. This combination produced 142.49 g l(-1) LA with a productivity level of 0.90 g of LA per gram of sugars consumed. The results indicated the high LA concentration achieved using L. salivarius CGMCC 7.75 not only gives cheap industrial product, but also broaden the application of sweet sorghum.

  4. Topological characterization of nanocrystalline cellulose reinforced Poly (lactic acid) and Poly-(3-hydroxybutyrate-co-3-hydroxyvalerate) bionanocomposites

    Science.gov (United States)

    Bhat, A. H.; Dasan, Y. K.; Khan, Ihsan Ullah; Ahmad, Faiz; Ayoub, Muhammad

    2016-11-01

    This study was conducted to evaluate the morphological and barrier properties of nanocrystalline cellulose reinforced Poly (lactic acid) and Poly-(3-hydroxybutyrate-co-3-hydroxyvalerate) bionanocomposites. Nanocrystalline cellulose was isolated from waste oil palm empty fruit bunch fiber using Sulphuric acid hydrolysis. Chemical modifications of nanocrystalline cellulose was performed to allow good compatibilization between fiber and the polymer matrices and also to improve dispersion of fillers. Bionanocomposite materials were produced from these nanocrystalline cellulose reinforced Poly (lactic acid) and Poly-(3-hydroxybutyrate-co-3-hydroxyvalerate) using solvent casting and evaporation techniques. The properties of extracted nanocrystalline cellulose were examined using FT-IR spectroscopy, X-ray diffractometer, TEM and AFM. Besides that, the properties of bionanocomposites were examined through FESEM and oxygen permeability properties analysis. Better barrier and morphological properties were obtained for nanocrystalline cellulose reinforced bionanocomposites than for neat polymer blend.

  5. THE SEARCH AND PROPERTIES OF LACTIC ACID BACTERIA PERSPECTIVE FOR BIOTECHNOLOGY

    Directory of Open Access Journals (Sweden)

    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.

  6. Inhibition of Listeria monocytogenes in Fresh Cheese Using Chitosan-Grafted Lactic Acid Packaging

    Directory of Open Access Journals (Sweden)

    Laura N. Sandoval

    2016-04-01

    Full Text Available A chitosan from biologically obtained chitin was successfully grafted with d,l-lactic acid (LA in aqueous media using p-toluenesulfonic acid as catalyst to obtain a non-toxic, biodegradable packaging material that was characterized using scanning electron microscopy, water vapor permeability, and relative humidity (RH losses. Additionally, the grafting in chitosan with LA produced films with improved mechanical properties. This material successfully extended the shelf life of fresh cheese and inhibited the growth of Listeria monocytogenes during 14 days at 4 °C and 22% RH, whereby inoculated samples with chitosan-g-LA packaging presented full bacterial inhibition. The results were compared to control samples and commercial low-density polyethylene packaging.

  7. Electrospun poly(lactic acid) based conducting nanofibrous networks

    International Nuclear Information System (INIS)

    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.

  8. Influence of yeast and lactic acid bacterium on the constituent profile of soy sauce during fermentation.

    Science.gov (United States)

    Harada, Risa; Yuzuki, Masanobu; Ito, Kotaro; Shiga, Kazuki; Bamba, Takeshi; Fukusaki, Eiichiro

    2017-02-01

    Soy sauce is a Japanese traditional seasoning composed of various constituents that are produced by various microbes during a long-term fermentation process. Due to the complexity of the process, the investigation of the constituent profile during fermentation is difficult. Metabolomics, the comprehensive study of low molecular weight compounds in biological samples, is thought to be a promising strategy for deep understanding of the constituent contribution to food flavor characteristics. Therefore, metabolomics is suitable for the analysis of soy sauce fermentation. Unfortunately, only few and unrefined studies of soy sauce fermentation using metabolomics approach have been reported. Therefore, we investigated changes in low molecular weight hydrophilic and volatile compounds of soy sauce using gas chromatography/mass spectrometry (GC/MS)-based non-targeted metabolic profiling. The data were analyzed by statistical analysis to evaluate influences of yeast and lactic acid bacterium on the constituent profile. Consequently, our results suggested a novel finding that lactic acid bacterium affected the production of several constituents such as cyclotene, furfural, furfuryl alcohol and methional in the soy sauce fermentation process. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  9. Process of converting starch to glucose and glucose to lactic acid

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, TenLin; Sanville, C.Y.; Coleman, R.D.; Schertz, W.W.

    1990-01-01

    This document describes a method for converting starch into lactic acid of sufficient purity for use as a substrate for biodegradable plastics. The process is designed to work on industrial food waste streams such as potato wastes or cheese whey permeate. For potato waste, {alpha}-amylase and calcium chloride are added to the starch containing waste and incubated at a pH of 4--7, a temperature of 90--130{degree}C, and a pressure above 15 psi for not less than 15 minutes. At this point, glucoamylase is added and the mixture is incubated at a temperature of 50--70{degree}C and a pH below 6.5 for 4 hours. This results in the conversion of more than 90% of the starch into glucose, which is substantially free of microbial contamination. The hydrolysate is filtered, and introduced with additional nutrients to a fermentor containing a lactose producing microorganism to form a fermentation broth. This results in the fermentation of glucose to lactose, which is filtered and subjected to electrodialysis for purification. Conversion of glucose to lactic acid or lactate occurs with an efficiency of over 95%. 1 fig. (MHB)

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

    Science.gov (United States)

    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.

  11. Complete Genome Sequence of the Probiotic Lactic Acid Bacterium Lactobacillus Rhamnosus

    Directory of Open Access Journals (Sweden)

    Samat Kozhakhmetov

    2014-01-01

    Full Text Available Introduction: Lactobacilli are a bacteria commonly found in the gastrointestinal tract. Some species of this genus have probiotic properties. The most common of these is Lactobacillus rhamnosus, a microoganism, generally regarded as safe (GRAS. It is also a homofermentative L-(+-lactic acid producer. The genus Lactobacillus is characterized by an extraordinary degree of the phenotypic and genotypic diversity. However, the studies of the genus were conducted mostly with the unequally distributed, non-random choice of species for sequencing; thus, there is only one representative genome from the Lactobacillus rhamnosus clade available to date. The aim of this study was to characterize the genome sequencing of selected strains of Lactobacilli. Methods: 109 samples were isolated from national domestic dairy products in the laboratory of Center for life sciences. After screaning isolates for probiotic properties, a highly active Lactobacillus spp strain was chosen. Genomic DNA was extracted according to the manufacturing protocol (Wizard® Genomic DNA Purification Kit. The Lactobacillus rhamnosus strain was identified as the highly active Lactobacillus strain accoridng to its morphological, cultural, physiological, and biochemical properties, and a genotypic analysis. Results: The genome of Lactobacillus rhamnosus was sequenced using the Roche 454 GS FLX (454 GS FLX platforms. The initial draft assembly was prepared from 14 large contigs (20 all contigs by the Newbler gsAssembler 2.3 (454 Life Sciences, Branford, CT. Conclusion: A full genome-sequencing of selected strains of lactic acid bacteria was made during the study.

  12. Acidulocompost, a food waste compost with thermophilic lactic acid fermentation: its effects on potato production and weed growth

    OpenAIRE

    Naomi Asagi; Keisuke Minamide; Toru Uno; Masanori Saito; Toyoaki Ito

    2016-01-01

    Acidulocomposting recycles food wastes by means of thermophilic lactic acid fermentation. This process can decrease ammonia volatilization and odor emission during processing and produce compost with high nitrogen (N) content. To compare the yield of potatoes (Solanum tuberosum L. ‘Dansyakuimo’) and the suppression of weeds with acidulocompost (AC) and those with conventional composts and inorganic fertilizer (IF), we conducted field experiments in Miyagi Prefecture, northeastern Japan. Potat...

  13. Effect of Commercial SiO2 and SiO2 from rice husk ash loading on biodegradation of Poly (lactic acid) and crosslinked Poly (lactic acid)

    Science.gov (United States)

    Prapruddivongs, C.; Apichartsitporn, M.; Wongpreedee, T.

    2017-09-01

    In this work, biodegradation behavior of poly (lactic acid) (PLA) and crosslinked PLA filled with two types of SiO2, precipitated SiO2 (commercial SiO2) and SiO2 from rice husk ash, were studied. Rice husks were first treated with 2 molar hydrochloric acid (HCl) to produce high purity SiO2, before burnt in a furnace at 800°C for 6 hours. All components were melted bending by an internal mixer then hot pressed using compression molder to form tested specimens. FTIR spectra of SiO2 and PLA samples were investigated. The results showed the lack of silanol group (Si-OH) of rice husk ash after steric acid surface modification, while the addition of particles can affect the crosslinking of the PLA. For biodegradation test by evaluating total amount of carbon dioxide (CO2) evolved during 60 days incubation at a controlled temperature of 58±2°C, the results showed that the biodegradation of crosslinked PLA occurred slower than the neat PLA. However, SiO2 incorporation enhanced the degree of biodegradation In particular, introducing commercial SiO2 in PLA and crosslinked PLA tended to clearly increase the degree of biodegradation as a consequence of the more accelerated hydrolysis degradation.

  14. Mannitol production by lactic acid bacteria grown in supplemented carob syrup.

    Science.gov (United States)

    Carvalheiro, Florbela; Moniz, Patrícia; Duarte, Luís C; Esteves, M Paula; Gírio, Francisco M

    2011-01-01

    Detailed kinetic and physiological characterisation of eight mannitol-producing lactic acid bacteria, Leuconostoc citreum ATCC 49370, L. mesenteroides subsp. cremoris ATCC19254, L. mesenteroides subsp. dextranicum ATCC 19255, L. ficulneum NRRL B-23447, L. fructosum NRRL B-2041, L. lactis ATCC 19256, Lactobacillus intermedius NRRL 3692 and Lb. reuteri DSM 20016, was performed using a carob-based culture medium, to evaluate their different metabolic capabilities. Cultures were thoroughly followed for 30 h to evaluate consumption of sugars, as well as production of biomass and metabolites. All strains produced mannitol at high yields (>0.70 g mannitol/g fructose) and volumetric productivities (>1.31 g/l h), and consumed fructose and glucose simultaneously, but fructose assimilation rate was always higher. The results obtained enable the studied strains to be divided mainly into two groups: one for which glucose assimilation rates were below 0.78 g/l h (strains ATCC 49370, ATCC 19256 and ATCC 19254) and the other for which they ranged between 1.41 and 1.89 g/l h (strains NRRL B-3692, NRRL B-2041, NRRL B-23447 and DSM 20016). These groups also exhibited different mannitol production rates and yields, being higher for the strains with faster glucose assimilation. Besides mannitol, all strains also produced lactic acid and acetic acid. The best performance was obtained for L. fructosum NRRL B-2041, with maximum volumetric productivity of 2.36 g/l h and the highest yield, stoichiometric conversion of fructose to mannitol.

  15. Film Sensor Device Fabricated by a Piezoelectric Poly(L-lactic acid) Film

    Science.gov (United States)

    Ando, Masamichi; Kawamura, Hideki; Kageyama, Keisuke; Tajitsu, Yoshiro

    2012-09-01

    Synthetic piezoelectric polymer films produced from petroleum feedstock have long been used as thin-film sensors and actuators. However, the fossil fuel requirements for synthetic polymer production and carbon dioxide emission from its combustion have raised concern about the environmental impact of its continued use. Eco-friendly biomass polymers, such as poly(L-lactic acid) (PLLA), are made from plant-based (vegetable starch) plastics and, thus, have a much smaller carbon footprint. Additionally, PLLA does not exhibit pyroelectricity or unnecessary poling. This suggests the usefulness of PLLA films for the human-machine interface (HMI). As an example of a new HMI, we have produced a TV remote control using a PLLA film. The intuitive operation provided by this PLLA device suggests that it is useful for the elderly or handicapped.

  16. Functional properties of lactic acid bacteria isolated from ethnic fermented vegetables of the Himalayas.

    Science.gov (United States)

    Tamang, Jyoti Prakash; Tamang, Buddhiman; Schillinger, Ulrich; Guigas, Claudia; Holzapfel, Wilhelm H

    2009-09-30

    A total of 94 strains of Lactic acid bacteria (LAB), previously isolated from ethnic fermented vegetables and tender bamboo shoots of the Himalayas, were screened for functional properties such as acidification capacity, enzymatic activities, degradation of antinutritive factors and oligosaccharides, production of biogenic amines, hydrophobicity and adherence to mucus secreting HT29 MTX cells. Strong acidification and coagulation activities of LAB strains were recorded. Most of the LAB strains showed antimicrobial activities against the used indicator strains; however, only Lb. plantarum IB2 (BFE 948) isolated from inziangsang, a fermented leafy vegetable product, produced a bacteriocin against Staphylococcus aureus S1. LAB strains showed enzymatic activities and also degraded oligosaccharides. Almost all the strains of LAB were non-producers of biogenic amines except few strains. Some strains of Lb. plantarum showed more than 70% hydrophobicity. Adherence to the mucus secreting HT29 MTX cells was also shown by seven strains indicating their probiotic nature.

  17. Purification Techniques of Bacteriocins from Lactic Acid Bacteria and Other Gram-Positive Bacteria

    Science.gov (United States)

    Saavedra, Lucila; Sesma, Fernando

    The search for new antimicrobial peptides produced by lactic acid ­bacteria and other Gram-positive microorganisms has become an interesting field of research in the past decades. The fact that bacteriocins are active against numerous foodborne and human pathogens, are produced by generally regarded as safe (GRAS) microorganisms, and are readily degraded by proteolytic host systems makes them attractive candidates for biotechnological applications. However, before suggesting or choosing a new bacteriocin for future technology developments, it is necessary to elucidate its biochemical structure and its mode of action, which may be carried out once the bacteriocin is purified to homogeneity. This chapter focuses on describing the main strategies used for the purification of numerous bacteriocins.

  18. Biotechnological and in situ food production of polyols by lactic acid bacteria.

    Science.gov (United States)

    Ortiz, Maria Eugenia; Bleckwedel, Juliana; Raya, Raúl R; Mozzi, Fernanda

    2013-06-01

    Polyols such as mannitol, erythritol, sorbitol, and xylitol are naturally found in fruits and vegetables and are produced by certain bacteria, fungi, yeasts, and algae. These sugar alcohols are widely used in food and pharmaceutical industries and in medicine because of their interesting physicochemical properties. In the food industry, polyols are employed as natural sweeteners applicable in light and diabetic food products. In the last decade, biotechnological production of polyols by lactic acid bacteria (LAB) has been investigated as an alternative to their current industrial production. While heterofermentative LAB may naturally produce mannitol and erythritol under certain culture conditions, sorbitol and xylitol have been only synthesized through metabolic engineering processes. This review deals with the spontaneous formation of mannitol and erythritol in fermented foods and their biotechnological production by heterofermentative LAB and briefly presented the metabolic engineering processes applied for polyol formation.

  19. Sprayed microspheres of poly(lactic acid) obtained with calcium compounds

    International Nuclear Information System (INIS)

    Goncalves, Raquel P.; Picciani, Paulo H. de Souza; Dias, Marcos L.

    2011-01-01

    In this work PLLA and PDLA were synthesized using calcium methoxide (Ca(OMe) 2 ) as initiator. This compound shows good activity in the bulk polymerization of L-lactide (LLA) and D-lactide (DLA) producing polymers with average molecular weight up to 22,300 g/mol, but with microstructure containing a significant amount of estereoerros, as revealed by 13 C NMR. Block copolymers containing blocks of L-and D-lactic acid were also prepared, using the method of sequential addition of LLA and DLA in an attempt to obtain stereo complexes. Analyses of scanning electron microscopy (SEM) revealed that the polymers obtained with catalysts of calcium produced PLA microspheres with diameters of around 5 μm via electro spray technique. (author)

  20. Isolation of Lactic Acid Bacteria with High Biological Activity from Local Fermented Dairy Products

    Directory of Open Access Journals (Sweden)

    B. Munkhtsetseg

    2009-12-01

    Full Text Available The thirty-two strains of lactic acid bacteria were isolated from the Mongolian traditional fermented dairy products, among them 25 strains show antimicrobial activity against test microorganisms including Escherichia coli , Staphylococcus aureus , Enterococcus faecalis , Pseudom о nas aeruginosa . Protease sensitivity assay demonstrated that the antimicrobial substances produced by isolates А 23, Т 2 are bacteriocins as their antibacterial activities were eliminated completely after treatment with protease. Identi fi cation of bacteria is being carried out. Among the isolates 22 strains show protease enzyme producing activity. The selected strains isolated from mare’s fermented milk (airag or kumis and yoghurt (tarag show the speci fi c protease activity from 7.9 μ g/ml to 11.9 μ g/ml. The strain T2, isolated from yoghurt exhibited the highest proteolytic activity.

  1. Lactic acid bacteria: promising supplements for enhancing the biological activities of kombucha.

    Science.gov (United States)

    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.

  2. Release of Polyphenols Is the Major Factor Influencing the Bioconversion of Rice Straw to Lactic Acid.

    Science.gov (United States)

    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.

  3. Antibacterial Activity of Lactic Acid Bacteria Isolated from Gastrointestinal Tract of “Ayam Kampung” Chicken Against Food Pathogens

    Science.gov (United States)

    Nur Jannah, Siti; Rini Saraswati, Tyas; Handayani, Dwi; Pujiyanto, Sri

    2018-05-01

    Food borne disease results from ingestion of water and wide variety of food contaminated with pathogenic organisms. The main causes of food borne diseases are bacteria, such as Escherichia coli and Staphylococcus aureus. The objective of this study was to determine antimicrobial activity of lactic acid bacteria (LAB) isolated from local chicken gastrointestinal tract with an emphasis on their probiotic properties. The colonies of bacteria that producing clear zone on MRSA plus 0.5% CaCO3, Gram-positive and catalase-negative were isolated as lactic acid bacteria. Some of the strains (10 isolates) were tested for their ability to inhibit growth of Escherichia coli and Staphylococcus aureus, and for acid pH and bile salt tolerance. The results showed that the all selected isolates producing antimicrobial compounds inhibits the growth of Escherichia coli and Staphylococcus aureus, both in the supernatant and supernatant plus 2M NaOH, and still growing in medium condition with pH 2.0 and 0.1% bile salt. It revealing the potential use of the lactic acid bacteria from chicken gastrointestinal tract for probiotics in food.

  4. Impact of lactic acid bacteria on conjugated linoleic acid content and atherogenic index of butter

    Directory of Open Access Journals (Sweden)

    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.

  5. Metabolite profile of koji amazake and its lactic acid fermentation product by Lactobacillus sakei UONUMA.

    Science.gov (United States)

    Oguro, Yoshifumi; Nishiwaki, Toshikazu; Shinada, Ryota; Kobayashi, Kazuya; Kurahashi, Atsushi

    2017-08-01

    The koji amazake is a traditional sweet Japanese beverage. It has been consumed for over a thousand years in Japan; nonetheless, little is yet known of the ingredients in koji amazake. Therefore, this study aimed to analyze the metabolites of koji amazake using a metabolomics approach. Additionally, we reformed the flavor of koji amazake by lactic acid fermentation (LAF-amazake) using Lactobacillus sakei UONUMA, which was isolated from snow caverns. The purpose of this article is to identify the ingredients in these beverages. In LAF-amazake and koji amazake, sugars, amino acids, organic acids, and vitamin B complex were determined in the two beverages, and over 300 compounds were detected in total. Thirteen saccharides were identified including two unknown trisaccharides, and there were no differences in these between the two beverages. In LAF-amazake, lactic acid, vitamin B2 (riboflavin), B3 (nicotinic acid and nicotinamide), and B6 (pyridoxine) were significantly increased as compared to koji amazake, whereas malate and glutamine decreased. These results suggested that LAF, malolactic fermentation, and glutamine deamidation occurred simultaneously in LAF-amazake. L. sakei UONUMA strains produced these vitamins. Moreover, it was surprising that acetylcholine, a well-known neurotransmitter, was newly generated in LAF-amazake. Here, we have succeeded in reforming the flavor of koji amazake and obtained these metabolic data on the two beverages. The present study could provide useful basic information for promoting functional analyses of koji amazake and LAF-amazake for human health. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  6. From honeycomb- to microsphere-patterned surfaces of poly(lactic acid) and a starch-poly(lactic acid) blend via the breath figure method.

    Science.gov (United States)

    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.

  7. Production of L-lactic acid from Cassava peel wastes using single and mixed cultures of Rhizopus oligosporus and Lactobacillus plantarum

    Directory of Open Access Journals (Sweden)

    Nwokoro Ogbonnaya

    2014-01-01

    Full Text Available Production of L-lactic acid using cultures of Rhizopus oligosporus and Lactobacillus plantarum was investigated. Cassava peels were hydrolyzed by boiling for 1 h in either NaOH or HCl solutions followed by neutralization to a pH of 6.2. Reducing sugar produced from the hydrolysates increased with increasing concentrations of alkali or acid. Samples hydrolyzed with HCl produced a maximum reducing sugar concentration of 402 mg/g substrate while alkali hydrolyzed samples produced a maximum reducing sugar concentration of 213 mg/g substrate. Hydrolysates were amended with 0.5% ammonium sulphate solution and inoculated with either single or mixed cultures of Rhizopus oligosporus and Lactobacillus plantarum and incubated for 48 h for lactic acid production. The best lactic acid production of 50.2 g/100g substrate was observed in a mixed culture fermentation of acid hydrolyzed peels. Mixed culture fermentation of alkali hydrolyzed peels produced a maximum lactic acid concentration of 36.4 g/100g substrate. Un hydrolyzed cassava peels inoculated with a mixed culture of the microorganisms produced only 4.6 g/100g substrate. This work reports an efficient use of cassava peels for bio-product formation through microbial fermentation.

  8. Characteristics of immobilized lactobacillus delbrueckii in a liquid-solid fluidized bed bioreactor for lactic acid production

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. Poly(ethylene glycol) (PEG)-lactic acid nanocarrier-based degradable hydrogels for restoring the vaginal microenvironment

    Science.gov (United States)

    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

  10. Wine phenolic compounds influence the production of volatile phenols by wine-related lactic acid bacteria.

    Science.gov (United States)

    Silva, I; Campos, F M; Hogg, T; Couto, J A

    2011-08-01

    To evaluate the effect of wine phenolic compounds on the production of volatile phenols (4-vinylphenol [4VP] and 4-ethylphenol [4EP]) from the metabolism of p-coumaric acid by lactic acid bacteria (LAB). Lactobacillus plantarum, Lactobacillus collinoides and Pediococcus pentosaceus were grown in MRS medium supplemented with p-coumaric acid, in the presence of different phenolic compounds: nonflavonoids (hydroxycinnamic and benzoic acids) and flavonoids (flavonols and flavanols). The inducibility of the enzymes involved in the p-coumaric acid metabolism was studied in resting cells. The hydroxycinnamic acids tested stimulated the capacity of LAB to synthesize volatile phenols. Growth in the presence of hydroxycinnamic acids, especially caffeic acid, induced the production of 4VP by resting cells. The hydroxybenzoic acids did not significantly affect the behaviour of the studied strains. Some of the flavonoids showed an effect on the production of volatile phenols, although strongly dependent on the bacterial species. Relatively high concentrations (1 g l(-1) ) of tannins inhibited the synthesis of 4VP by Lact. plantarum. Hydroxycinnamic acids were the main compounds stimulating the production of volatile phenols by LAB. The results suggest that caffeic and ferulic acids induce the synthesis of the cinnamate decarboxylase involved in the metabolism of p-coumaric acid. On the other hand, tannins exert an inhibitory effect. This study highlights the capacity of LAB to produce volatile phenols and that this activity is markedly influenced by the phenolic composition of the medium. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

  11. Systems biology of lactic acid bacteria: a critical review.

    Science.gov (United States)

    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.

  12. Interactions between Cooccurring Lactic Acid Bacteria in Honey Bee Hives.

    Science.gov (United States)

    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.

  13. [Cloning and gene expression in lactic acid bacteria].

    Science.gov (United States)

    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.

  14. Strategies for improving production performance of probiotic Pediococcus acidilactici viable cell by overcoming lactic acid inhibition.

    Science.gov (United States)

    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.

  15. Lactic acid fermentation of human urine to improve its fertilizing value and reduce odour emissions.

    Science.gov (United States)

    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.

  16. Cost-effective simultaneous saccharification and fermentation of l-lactic acid from bagasse sulfite pulp by Bacillus coagulans CC17.

    Science.gov (United States)

    Zhou, Jie; Ouyang, Jia; Xu, Qianqian; Zheng, Zhaojuan

    2016-12-01

    The main barriers to cost-effective lactic acid production from lignocellulose are the high cost of enzymes and the ineffective utilization of the xylose within the hydrolysate. In the present study, the thermophilic Bacillus coagulans strain CC17 was used for the simultaneous saccharification and fermentation (SSF) of bagasse sulfite pulp (BSP) to produce l-lactic acid. Unexpectedly, SSF by CC17 required approximately 33.33% less fungal cellulase than did separate hydrolysis and fermentation (SHF). More interestingly, CC17 can co-ferment cellobiose and xylose without any exogenous β-glucosidase in SSF. Moreover, adding xylanase could increase the concentration of lactic acid produced via SSF. Up to 110g/L of l-lactic acid was obtained using fed-batch SSF, resulting in a lactic acid yield of 0.72g/g cellulose. These results suggest that SSF using CC17 has a remarkable advantage over SHF and that a potentially low-cost and highly-efficient fermentation process can be established using this protocol. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Lactic acid bacteria involved in cocoa beans fermentation from Ivory Coast: Species diversity and citrate lyase production.

    Science.gov (United States)

    Ouattara, Hadja D; Ouattara, Honoré G; Droux, Michel; Reverchon, Sylvie; Nasser, William; Niamke, Sébastien L

    2017-09-01

    Microbial fermentation is an indispensable process for high quality chocolate from cocoa bean raw material. lactic acid bacteria (LAB) are among the major microorganisms responsible for cocoa fermentation but their exact role remains to be elucidated. In this study, we analyzed the diversity of LAB in six cocoa producing regions of Ivory Coast. Ribosomal 16S gene sequence analysis showed that Lactobacillus plantarum and Leuconostoc mesenteroides are the dominant LAB species in these six regions. In addition, other species were identified as the minor microbial population, namely Lactobacillus curieae, Enterococcus faecium, Fructobacillus pseudoficulneus, Lactobacillus casei, Weissella paramesenteroides and Weissella cibaria. However, in each region, the LAB microbial population was composed of a restricted number of species (maximum 5 species), which varied between the different regions. LAB implication in the breakdown of citric acid was investigated as a fundamental property for a successful cocoa fermentation process. High citrate lyase producer strains were characterized by rapid citric acid consumption, as revealed by a 4-fold decrease in citric acid concentration in the growth medium within 12h, concomitant with an increase in acetic acid and lactic acid concentration. The production of citrate lyase was strongly dependent on environmental conditions, with optimum production at acidic pH (pHfermentation. This study reveals that one of the major roles of LAB in the cocoa fermentation process involves the breakdown of citric acid during the early stage of cocoa fermentation through the activity of citrate lyase. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Biodiversity and γ-aminobutyric acid production by lactic acid bacteria isolated from traditional alpine raw cow's milk cheeses.

    Science.gov (United States)

    Franciosi, Elena; Carafa, Ilaria; Nardin, Tiziana; Schiavon, Silvia; Poznanski, Elisa; Cavazza, Agostino; Larcher, Roberto; Tuohy, Kieran M

    2015-01-01

    "Nostrano-cheeses" are traditional alpine cheeses made from raw cow's milk in Trentino-Alto Adige, Italy. This study identified lactic acid bacteria (LAB) developing during maturation of "Nostrano-cheeses" and evaluated their potential to produce γ-aminobutyric acid (GABA), an immunologically active compound and neurotransmitter. Cheese samples were collected on six cheese-making days, in three dairy factories located in different areas of Trentino and at different stages of cheese ripening (24 h, 15 days, and 1, 2, 3, 6, and 8 months). A total of 1,059 LAB isolates were screened using Random Amplified Polymorphic DNA-PCR (RAPD-PCR) and differentiated into 583 clusters. LAB strains from dominant clusters (n = 97) were genetically identified to species level by partial 16S rRNA gene sequencing. LAB species most frequently isolated were Lactobacillus paracasei, Streptococcus thermophilus, and Leuconostoc mesenteroides. The 97 dominant clusters were also characterized for their ability in producing GABA by high-performance liquid chromatography (HPLC). About 71% of the dominant bacteria clusters evolving during cheeses ripening were able to produce GABA. Most GABA producers were Lactobacillus paracasei but other GABA producing species included Lactococcus lactis, Lactobacillus plantarum, Lactobacillus rhamnosus, Pediococcus pentosaceus, and Streptococcus thermophilus. No Enterococcus faecalis or Sc. macedonicus isolates produced GABA. The isolate producing the highest amount of GABA (80.0±2.7 mg/kg) was a Sc. thermophilus.

  19. Performance properties, lactic acid specific migration and swelling by simulant of biodegradable poly(lactic acid)/nanoclay multilayer films for food packaging.

    Science.gov (United States)

    Scarfato, Paola; Di Maio, Luciano; Milana, Maria Rosaria; Giamberardini, Silvia; Denaro, Massimo; Incarnato, Loredana

    2017-10-01

    The aim of the study was the development of a multifunctional, high-performance, fully biodegradable multilayer polylactic acid (PLA) film for food packaging applications. In particular, sealable multilayer PLA-clay nanocomposite systems with different layouts in terms of composition and relative thickness of the layers, all consisting of a PLA-clay nanocomposite layer between two pure PLA layers for direct food contact, were designed and produced by blown film co-extrusion. The films obtained were analysed for their morphology, functional properties and lactic acid (LA)-specific migration in 50% ethanol. The results showed that, with respect to the unfilled multilayer system, taken as a reference, the nanocomposite films had significant improvements, up to about 40%, in their barriers to oxygen and tensile strengths, and resulted in being more easily sealable over a wide heat-sealing temperature range (80-100°C) with higher seal strength. Moreover, all films had LA migrations always well below the former generic overall migration limit of 60 mg kg -1 food (10 mg dm - 2 ) of European Union Regulation No. 10/2011 (deleted by the amending Regulation No. 2016/1416), even if their morphology was strongly modified during the migration tests due to the strong swelling action of the used simulant (simulant D1 = 50% ethanol (aq.) (v/v)) towards PLA.

  20. Simultaneous Saccharification and Fermentation of Sugar Beet Pulp with Mixed Bacterial Cultures for Lactic Acid and Propylene Glycol Production

    Directory of Open Access Journals (Sweden)

    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.