scholarly journals The influence of compression level and inoculation on biochemical changes in lucerne silages

2011 ◽  
Vol 56 (1) ◽  
pp. 15-23 ◽  
Author(s):  
Nenad Djordjevic ◽  
Goran Grubic ◽  
Bojan Stojanovic ◽  
Aleksa Bozickovic
Keyword(s):  
Acetic Acid ◽  
Lactic Acid ◽  
Chemical Composition ◽  
Acid Production ◽  
Lactic Acid Production ◽  
Ammonia Nitrogen ◽  
Soluble Nitrogen ◽  
Acetic Acid Production ◽  
Protein Nitrogen ◽  
True Protein

The effect of different levels of compression (A1 = 420 gdm-1, A2 = 560 gdm-1) and inoculation (B1 = no inoculant, B2 = with inoculant) on changes in chemical composition, proteolysis and quality of lucerne silage was investigated in this paper. Based on the results of chemical analysis we found that in silages with more compressed material there was a reduction in the amount of ammonia nitrogen, soluble nitrogen and acetic acid, and increased content of protein nitrogen (?true?protein) and production of lactic acid (p<0.05). With the inoculation of the ensiling material the production of ammonia nitrogen and acetic acid was reduced but the content of lactic acid and acidity was increased (p<0.05). The interaction of both investigated factors (A?B) induced a decrease in the proteolysis degree, increase of lactic acid production and decrease in acetic acid production, and decrease in pH values (p<0.001) in investigated silages. The investigated factors had less influence on the chemical composition of lucerne material, and the significant variations were observed in fat and NFE contents. On the basis of this investigation the degree of compression is the most important parameter in ensiling technology. With the adequate compression and reduction of air in the starting material, the aerobic phase is reduced and the activity of proeolytic enzymes is decreased. In practice the special attention should be given to factors on which directly or indirectly the level of compression of ensiled material depends: wilting, cutting, object selection and/or selection of machines used for compression.

scholarly journals LARGE MICROBIOTA SURVEY REVEALS HOW THE MICROBIAL ECOLOGY OF COOKED HAM IS SHAPED BY DIFFERENT PROCESSING STEPS

2019 ◽  
Author(s):  
Marine Zagdoun ◽  
Gwendoline Coeuret ◽  
Méry N’Dione ◽  
Marie-Christine Champomier-Vergès ◽  
Stéphane Chaillou
Keyword(s):  
Acetic Acid ◽  
Lactic Acid ◽  
Acid Production ◽  
Lactic Acid Production ◽  
Amplicon Sequencing ◽  
Acetic Acid Production ◽  
Serratia Proteamaculans ◽  
Production Type ◽  
Cooked Ham ◽  
Metabolites Production

ABSTRACTThe production of cooked ham involves numerous steps shaping the microbial communities of the final product, with consequences on spoilage metabolites production. To identify the main factors driving the ecology of ham and its spoilage, we designed a study encompassing five variables related to ham production: type of storage during meat transportation, churning speed, drain-off time, slicing line and O2 packaging permeability. We obtained about 200 samples from the same facility and we characterized i) their microbiota based on gyrB amplicon sequencing ii) their production of spoilage-related metabolites based on E-Nose analysis and enzymatic assays. The slicing was the most critical step, shaping two general types of microbiota according to the slicing line: one dominated by Carnobacterium divergens and another one dominated by Leuconostoc carnosum and Serratia proteamaculans. Regarding metabolites production, L. carnosum was associated to D-lactic acid, ethanol and acetic acid production, whereas Serratia proteamaculans was associated to acetic acid production. This last species prevailed with highly O2-permeable packaging. Within a given slicing line, we observed campaign-based variations, with Lactobacillus sakei, Leuconostoc mesenteroides and Carnobacterium maltaromaticum prevalent in summer. L. sakei was associated with L-lactic acid production and C. maltaromaticum with formic and acetic acid productions.

scholarly journals Microbial and metabolite profiles of spontaneous and adjunct-inoculated cacao (Theobroma cacao L.) fermentation

Food Research ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 331-339
Author(s):  
J.G.B. Peralta ◽  
F.B. Elegado ◽  
J.F. Simbahan ◽  
I.G. Pajares ◽  
E.I. Dizon
Keyword(s):  
Acetic Acid ◽  
Lactic Acid ◽  
Acid Production ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Lactic Acid Production ◽  
Acetic Acid Bacteria ◽  
Acetic Acid Production ◽  
Culture Independent ◽  
Gradient Gel Electrophoresis ◽  
Set Up

The succession of the dominant microbial population during cacao fermentation with or without adjunct inoculation of yeast and lactic acid bacteria (LAB) were monitored on a laboratory scale using culture-dependent and culture-independent methods. Yeasts and acetic acid bacteria (AAB) population throughout a five-day fermentation process showed no significant differences but the LAB population increased through adjunct inoculation. Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) identification method showed the dominance of only Lactobacillus plantarum, one of the species used as the adjunct inoculum, which resulted in higher lactic acid production. On the other hand, Acetobacter spp. and Gluconobacter spp. were markedly observed in the spontaneously fermented set-up resulting in increased acetic acid production, significantly different (p>0.05) at three to five days of fermentation. LAB and yeast inoculation resulted in a more desirable temperature and pH of the fermenting mash which may result in better product quality.

scholarly journals Impact of non-protein nitrogen substances on grape pomace silage quality

2015 ◽  
Vol 31 (3) ◽  
pp. 433-440
Author(s):  
B. Dinic ◽  
N. Djordjevic ◽  
J. Markovic ◽  
D. Sokolovic ◽  
M. Blagojevic ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Chemical Composition ◽  
Total Nitrogen ◽  
Nutritional Value ◽  
Fermentation Process ◽  
Ammonia Nitrogen ◽  
Grape Pomace ◽  
Soluble Nitrogen ◽  
Protein Nitrogen ◽  
Silage Quality

In this study grape pomace was ensilaged without and with the addition of NPN substances (Benural) at the dose of 0.5, 1.0 and 1.5% of the amount of husk and with the addition of inoculant based on homo and hetero fermentative lactic acid bacteria. The greatest effect on the nutritional value had application of Benural, especially in increasing the CP content from 126.9 to 178.3 g kg-1DM, an increase of over 40%. Application of Benural increased the ammonia and soluble nitrogen several times, but even with the maximum addition of Benural percentage of ammonia nitrogen in the total nitrogen reached only slightly above 5% NH3-N/? N (5.38%), while the percentage of soluble nitrogen in total nitrogen was 28.29%. The application of inoculants generally had no significant impact, both on the chemical composition and the fermentation process.

scholarly journals AVALIAÇÃO DA ATIVIDADE BACTERIOCINOGÊNICA DO Lactobacillus sakei NA FERMENTAÇÃO DA SARDINHA-VERDADEIRA ( Sardinella brasiliensis) UTILIZANDO GLICOSE COMO CARBOIDRATO FERMENTECÍVEL

2003 ◽  
Vol 21 (1) ◽  
Author(s):  
MILTON LUIZ PINHO ESPÍRITO SANTO ◽  
LUIZ HENRIQUE BEIRÃO ◽  
ERNANI SANT’ANNA ◽  
CESAR DAMIAN ◽  
BERNADETTE MELLO FRANCO
Keyword(s):  
Lactic Acid ◽  
Sodium Chloride ◽  
Lactic Acid Production ◽  
Starter Culture ◽  
Soluble Nitrogen ◽  
Lactobacillus Sakei ◽  
Protein Nitrogen ◽  
Ph Values ◽  
Bacteriocin Producer ◽  
Initial Ph

Lactobacillus sakei é comprovadamente uma cepa produtora de bacteriocinas e, neste estudo, procurou-se observar seus efeitos na fermentação de filés de sardinha ( Sardinella brasiliensis) em diferentes concentrações de NaCl e glicose. Verificou-se sua habilidade para produzir ácidos orgânicos e conseqüente redução do pH durante 21 dias de fermentação. Ao término desse período, a concentração de microrganismos deterioradores atingiu 9,7 log UFC g-1 correspondente a 6% de NaCl e 4% de glicose. Poucas diferenças foram observadas na produção de ácido lático quando se adicionou 2 e 4% de glicose, já que a acidez total foi 1,32 e 1,34%, respectivamente, para os experimentos com 6% de NaCl. O pH 6 inicial dos filés modificou-se ao término de 21 dias para 3,8, 3,9 e 4 nos experimentos com 2, 4 e 6% de NaCl. Tal comportamento pode ser atribuído ao poder inibidor do NaCl sobre a microbiota deterioradora. No término da fermentação, a concentração de bactérias ácido lácticas foi 14,5 log10 UFC g-1. A relação entre o nitrogênio protéico e o nitrogênio solúvel total mostrou-se típica de pescado salgado/curado em perfeitas condições de consumo. EVALUATION OF BACTERIOCINOGENIC ACTIVITY OF Lactobacillus sakei IN THE FERMENTETION OF TRUE SARDINE (Sardinella brasiliensis) BY UTILIZING GLUCOSE AS FERMENTABLE CARBOHYDRATE Abstract Lactobacillus sakei 2a is a bacteriocin producer strain and, in this study, it’s effects as a starter culture in the curing process of sardine ( Sardinella brasiliensis) fillets were observed at different concentrations of sodium chloride and glucose. It’s ability to produce organic acids and pH reduction during 21 days of fermentation was verified. After this period, the deteriorative microbiota concentration reached 9.7 log10 CFU. g-1 corresponding to 6% sodium chloride and 4% glucose. Little differences were observed in lactic acid production when 2 and 4% glucose were added, since total acidity was 1.32 and 1.34% respectively for the experiments with 6% NaCl. Initial pH of fillets was 6 and after 21 days pH values were 3.8, 3.9 and 4 for the experiments with 2, 4 and 6% NaCl. This may have been due to the inhibitory properties of NaCl over the deteriorative microbiota. At the end of the fermentation process lactic acid bacteria concentrations were 14.5 log10 CFU.g-1. The ratio protein nitrogen and total soluble nitrogen was typical of a cured fish under perfect eating conditions.

207. Protein metabolism and acid production by the lactic acid bacteria in milk. Influence of yeast extract and chalk

1939 ◽  
Vol 10 (1) ◽  
pp. 20-34 ◽  
Author(s):  
M. Braz ◽  
L. A. Allen
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Proteolytic Activity ◽  
Yeast Extract ◽  
Protein Metabolism ◽  
Acid Production ◽  
Single Species ◽  
Soluble Nitrogen ◽  
Protein Breakdown ◽  
Protein Nitrogen

Though the lactic acid bacteria are recognized primarily as saccharolytic, several workers have recorded observations on their slow proteolytic activity. Von Freudenreich(1) was the first to record the fact that cultures of these organisms in milk, to which chalk had been added to neutralize the acidity, formed appreciable amounts of soluble nitrogen, and these findings were confirmed by Orla-Jensen (2), Barthel(3), and Barthel & Sandberg(4). Anderegg & Hammer (5), in a study of a large number of strains ofStr. Lactis, found an increase in soluble nitrogen in some cases and a decrease in others, while occasionally the same strain differed in different tests. In general, cultures which clotted rapidly were more inclined to proteolysis than those which were slower in forming acid.Str. citrovorusandStr. paracitrovorusdid not cause protein breakdown. Addition of 0·3% peptone to the milk tended to retard proteolysis or to increase negative values while addition of chalk resulted in more extensive proteolysis. Barthel & Sadler (6) found that starters consisting of mixed cultures of streptococci produced more extensive proteolysis than single species, indicating a symbiotic effect. Sherwood & Whitehead (7) tested the proteolytic powers of several strains ofStr. cremorisin chalk milk cultures and found some active and some comparatively inactive. Two strains appear to have formed surprisingly large amounts of non-protein nitrogen. In general they found that acid-producing power was linked with proteolytic power.

scholarly journals Towards a Starter Culture for Cocoa Fermentation by the Selection of Acetic Acid Bacteria

Fermentation ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 42
Author(s):  
Lucie Farrera ◽  
Alexandre Colas de la Noue ◽  
Caroline Strub ◽  
Benjamin Guibert ◽  
Christelle Kouame ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Lactic Acid ◽  
Acid Production ◽  
Acetic Acid Bacteria ◽  
Intraspecific Diversity ◽  
Cocoa Bean ◽  
Acetic Acid Production ◽  
Cocoa Bean Fermentation ◽  
The Impact ◽  
Selection Of

Acetic acid bacteria are involved in many food and beverage fermentation processes. They play an important role in cocoa bean fermentation through their acetic acid production. They initiate the development of some of the flavor precursors that are necessary for the organoleptic quality of cocoa, and for the beans’ color. The development of starter cultures with local strains would enable the preservation of the microbial biodiversity of each country in cocoa-producing areas, and would also control the fermentation. This approach could avoid the standardization of cocoa bean fermentation in the producing countries. One hundred and thirty acetic acid bacteria were isolated from three different cocoa-producing countries, and were identified based on their 16S rRNA gene sequence. The predominate strains were grown in a cocoa pulp simulation medium (CPSM-AAB) in order to compare their physiological traits regarding their specific growth rate, ethanol and lactic acid consumption, acetic acid production, and relative preferences of carbon sources. Finally, the intraspecific diversity of the strains was then assessed through the analysis of their genomic polymorphism by (GTG)5-PCR fingerprinting. Our results showed that Acetobacter pasteurianus was the most recovered species in all of the origins, with 86 isolates out of 130 cultures. A great similarity was observed between the strains according to their physiological characterization and genomic polymorphisms. However, the multi-parametric clustering results in the different groups highlighted some differences in their basic metabolism, such as their efficiency in converting carbon substrates to acetate, and their relative affinity to lactic acid and ethanol. The A. pasteurianus strains showed different behaviors regarding their ability to oxidize ethanol and lactic acid into acetic acid, and in their relative preference for each substrate. The impact of these behaviors on the cocoa quality should be investigated, and should be considered as a criterion for the selection of acetic acid bacteria starters.

scholarly journals Bacteriocinogenic effect of Lactobacillus sakei 2a on microbiological quality of fermented Sardinella brasiliensis

2003 ◽  
Vol 46 (4) ◽  
pp. 553-561 ◽  
Author(s):  
Milton L. P. Espírito Santo ◽  
Luiz H. Beirão ◽  
Ernani S. Sant'Anna ◽  
Eliana Bressa Dalcin ◽  
Bernadette G. M. Franco
Keyword(s):  
Lactic Acid ◽  
Fermentation Process ◽  
Lactic Acid Production ◽  
Starter Culture ◽  
Microbiological Quality ◽  
Soluble Nitrogen ◽  
Lactobacillus Sakei ◽  
Protein Nitrogen ◽  
Bacteriocin Producer ◽  
Initial Ph

Lactobacillus sakei 2a is a bacteriocin producer strain and, in this work, it's effects as a starter culture in the fermentation process of sardine (Sardinella brasiliensis) fillets were observed at different concentrations of NaCl (2, 4 and 6%) and glucose (2 and 4%), to determine it's ability to produce organic acids and consequent pH reduction. Experiments were carried out independently, with only one parameter (NaCl or glucose) varying at a time. After 21 days of fermentation the deteriorative bacteria concentration reached 9.7 Log10 CFU. g-1 corresponding to 6% NaCl and 4% glucose. Little differences were observed in lactic acid production when 2 and 4% glucose were added, since total acidity was 1.32 and 1.34% respectively, the experiments with 6% NaCl presented the best results. Initial pH of sardine fillets was 6 and after 21 days pH values were 3.8, 3.9 and 4 for the experiments with 2, 4 and 6% NaCl. This may have been due to the inhibitory properties of NaCl over the deteriorative bacteria. After 21 days of the fermentation process lactic acid bacteria concentrations were 14.5 Log10 CFU.g-1. The ratio protein nitrogen and total soluble nitrogen was typical of a cured fish.

scholarly journals l-Lactic Acid Production Using Engineered Saccharomyces cerevisiae with Improved Organic Acid Tolerance

2021 ◽  
Vol 7 (11) ◽  
pp. 928
Author(s):  
Byeong-Kwan Jang ◽  
Yebin Ju ◽  
Deokyeol Jeong ◽  
Sung-Keun Jung ◽  
Chang-Kil Kim ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Acetic Acid ◽  
Lactic Acid ◽  
Acid Production ◽  
Lactic Acid Production ◽  
Acid Tolerance ◽  
Production Costs ◽  
High Concentration ◽  
Adaptive Laboratory Evolution ◽  
Engineered Saccharomyces Cerevisiae

Lactic acid is mainly used to produce bio-based, bio-degradable polylactic acid. For industrial production of lactic acid, engineered Saccharomyces cerevisiae can be used. To avoid cellular toxicity caused by lactic acid accumulation, pH-neutralizing agents are used, leading to increased production costs. In this study, lactic acid-producing S. cerevisiae BK01 was developed with improved lactic acid tolerance through adaptive laboratory evolution (ALE) on 8% lactic acid. The genetic basis of BK01 could not be determined, suggesting complex mechanisms associated with lactic acid tolerance. However, BK01 had distinctive metabolomic traits clearly separated from the parental strain, and lactic acid production was improved by 17% (from 102 g/L to 119 g/L). To the best of our knowledge, this is the highest lactic acid titer produced by engineered S. cerevisiae without the use of pH neutralizers. Moreover, cellulosic lactic acid production by BK01 was demonstrated using acetate-rich buckwheat husk hydrolysates. Particularly, BK01 revealed improved tolerance against acetic acid of the hydrolysates, a major fermentation inhibitor of lignocellulosic biomass. In short, ALE with a high concentration of lactic acid improved lactic acid production as well as acetic acid tolerance of BK01, suggesting a potential for economically viable cellulosic lactic acid production.

scholarly journals Lachancea thermotolerans, the Non-Saccharomyces Yeast that Reduces the Volatile Acidity of Wines

Fermentation ◽  
2018 ◽  
Vol 4 (3) ◽  
pp. 56 ◽  
Author(s):  
Alice Vilela
Keyword(s):  
Acetic Acid ◽  
Lactic Acid ◽  
Acid Production ◽  
Lactic Acid Production ◽  
High Concentration ◽  
Volatile Acidity ◽  
Saccharomyces Yeast ◽  
Lachancea Thermotolerans

To improve the quality of fermented drinks, or more specifically, wine, some strains of yeast have been isolated, tested and studied, such as Saccharomyces and non-Saccharomyces. Some non-conventional yeasts present good fermentative capacities and are able to ferment in quite undesirable conditions, such as the case of must, or wines that have a high concentration of acetic acid. One of those yeasts is Lachancea thermotolerants (L. thermotolerans), which has been studied for its use in wine due to its ability to decrease pH through L-lactic acid production, giving the wines a pleasant acidity. This review focuses on the recent discovery of an interesting feature of L. thermotolerans—namely, its ability to decrease wines’ volatile acidity.

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