Antimicrobial Action of Hydrolyzed Chitosan against Spoilage Yeasts and Lactic Acid Bacteria of Fermented Vegetables

2002 ◽  
Vol 65 (5) ◽  
pp. 828-833 ◽  
Author(s):  
TONY SAVARD ◽  
CAROLE BEAULIEU ◽  
ISABELLE BOUCHER ◽  
CLAUDE P. CHAMPAGNE

The antimicrobial properties of various chitosan-lactate polymers (ranging from 0.5 to 1.2 MDa in molecular weight) against two yeasts isolated from fermented vegetables and against three lactic acid bacteria from a mixed starter for sauerkraut on methylene blue agar (MBA) and in vegetable juice medium (VJM) were investigated. Chitosan-lactate reduced the growth of all microorganisms in solid (MBA) as well as in liquid (VJM) medium. In MBA, a concentration of 5 g/liter was needed to inhibit the growth of Saccharomyces bayanus, while 1 g/liter was sufficient to inhibit the growth of Saccharomyces unisporus. Lactic acid bacteria were also inhibited in this range of concentrations. The low-molecular-weightchitosan-lactateDP3 (0.5 kDa) was most efficient in solid medium (MBA), and inhibitory activities decreased with increasing hydrolysate lengths. In liquid medium (VJM), 0.5 g of chitosan-lactate per liter reduced the growth rates for both yeasts, but 10 g/liter was insufficient to prevent yeast growth. Intermediate-molecular-weight chitosan-lactate (5 kDa) was more efficient than chitosan of low molecular weight. Native chitosan (1.2 MDa) showed no inhibition in either medium. Microscopic examination of S. unisporus Y-42 after treatment with chitosan-lactate DP25 showed agglutination of a refractive substance on the entire cell wall, suggesting an interaction between chitosan and the cell wall. When chitosanase was added to the culture media containing chitosan-lactate, refractive substances could not be observed.

2017 ◽  
Vol 54 (1) ◽  
pp. 69
Author(s):  
J. METAXOPOULOS (Ι. ΜΕΤΑΞΟΠΟΥΛΟΣ) ◽  
M. MATARAGAS (M. ΜΑΤΑΡΑΓΚΑΣ) ◽  
E. H. DROSINOS (Ε.Χ. ΔΡΟΣΙΝΟΣ)

Lactic acid bacteria produce a variety of small molecular weight compounds, which have antimicrobial properties. Such substances are: organic acids, alcohols, carbon dioxide, diacetyl, hydrogen peroxide and bacteriocins. Many of these compounds have a wide inhibitory spectrum but the bacteriocins are able to inhibit species, namely, related with the bacteriocin-producing strain. In the last years bacteriocins have gained a lot of concern because some of them are able to inhibit the growth of pathogenic bacteria, like Listeria monocytogenes. The term "biopreservation" refers to the extension of storage life, as well as to the enhancement of the food safety, using the bacteriocin-producing lactic acid strains or their metabolic antibacterial products. In this review will be reported bacteriocins, which are produced by the lactic acid bacteria and will be discussed the potential application of the bacteriocinogenic strains or their bacteriocins on the foods, as protective cultures or as protective compounds, respectively.


2013 ◽  
Vol 42 (6) ◽  
pp. 991-995 ◽  
Author(s):  
So-Lim Park ◽  
Sunhyun Park ◽  
Jieun Jang ◽  
Hye-Jung Yang ◽  
Sung-Won Moon ◽  
...  

Author(s):  
M Gonzalez Yanez ◽  
R Mcginn ◽  
D H Anderson ◽  
A R Henderson ◽  
P Phillips

It Is claimed that the use of the correct enzyme system as an additive on grass silage will satisfactorily control the fermentation and reduce the cell-wall fibre content, thus preserving the nutrients In the silage and aiding their utilisation by the animal (Henderson and McDonald, 1977; Huhtanen et al, 1985; Raurama et al, 1987; Chamberlain and Robertson, 1989; Gordon, 1989;).The aim of the present experiment was to assess the effect of biological additives, enzymes or a combination of enzymes with an Inoculum of lactic acid bacteria, on the composition of silage and on its nutritive value when offered to store lambs as the sole constituent of their diet.On 1st June 1988, first cut perennial ryegrass (Lolium perenne L) at pre-ear emergence was ensiled direct cut untreated (U), treated with a commercial enzyme (E) or with a commercial inoculum of lactic acid bacteria with enzymes (I) in 6t capacity bunker silos. The grass was cut with a mower and lifted with a New Holland precision chop forage harvester. The additives were pumped onto the grass using a dribble bar sited over the pick-up drum.


Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4571
Author(s):  
Antonio Morata ◽  
Iris Loira ◽  
Carmen González ◽  
Carlos Escott

Off-flavors produced by undesirable microbial spoilage are a major concern in wineries, as they affect wine quality. This situation is worse in warm areas affected by global warming because of the resulting higher pHs in wines. Natural biotechnologies can aid in effectively controlling these processes, while reducing the use of chemical preservatives such as SO2. Bioacidification reduces the development of spoilage yeasts and bacteria, but also increases the amount of molecular SO2, which allows for lower total levels. The use of non-Saccharomyces yeasts, such as Lachancea thermotolerans, results in effective acidification through the production of lactic acid from sugars. Furthermore, high lactic acid contents (>4 g/L) inhibit lactic acid bacteria and have some effect on Brettanomyces. Additionally, the use of yeasts with hydroxycinnamate decarboxylase (HCDC) activity can be useful to promote the fermentative formation of stable vinylphenolic pyranoanthocyanins, reducing the amount of ethylphenol precursors. This biotechnology increases the amount of stable pigments and simultaneously prevents the formation of high contents of ethylphenols, even when the wine is contaminated by Brettanomyces.


2021 ◽  
Vol 9 (7) ◽  
pp. 1346
Author(s):  
Mariana Petkova ◽  
Petya Stefanova ◽  
Velitchka Gotcheva ◽  
Angel Angelov

Traditional sourdoughs in Bulgaria were almost extinct during the centralized food production system. However, a rapidly developing trend of sourdough revival in the country is setting the demand for increased production and use of commercial starter cultures. The selection of strains for such cultures is based on geographical specificity and beneficial technological properties. In this connection, the aim of this study was to isolate, identify and characterize lactic acid bacteria (LAB) and yeasts from typical Bulgarian sourdoughs for the selection of strains for commercial sourdough starter cultures. Twelve samples of typical Bulgarian sourdoughs were collected from different geographical locations. All samples were analyzed for pH, total titratable acidity and dry matter content. Enumeration of LAB and yeast was also carried out. Molecular identification by 16S rDNA sequence analysis was performed for 167 LAB isolates, and 106 yeast strains were identified by ITS1-5.8S-ITS2 rRNA gene partial sequence analysis. The LAB strains were characterized according to their amylolytic and proteolytic activity and acidification capacity, and 11 strains were selected for further testing of their antimicrobial properties. The strains with the most pronounced antibacterial and antifungal activity are listed as recommended candidates for the development of starter cultures for sourdoughs or other food products.


2007 ◽  
Vol 70 (6) ◽  
pp. 1518-1522 ◽  
Author(s):  
V. B. SUÁREZ ◽  
M. L. CAPRA ◽  
M. RIVERA ◽  
J. A. REINHEIMER

The capacity of three phosphates to interrupt the lytic cycle of four specific autochthonal bacteriophages of lactic acid bacteria used as starters was assayed. The phosphates used (polyphosphates A and B and sodium tripolyphosphate–high solubility [TAS]) were selected on the basis of their capacity to sequester divalent cations, which are involved in the lytic cycle of certain bacteriophages. The assays were performed in culture media (deMan Rogosa Sharpe and Elliker broths) and reconstituted (10%, wt/vol) commercial skim milk to which phosphates had been added at concentrations of 0.1, 0.3, and 0.5% (wt/vol). Phosphate TAS was the most inhibitory one, since it was able to inhibit the lytic cycle of all bacteriophages studied, in both broths and milk. In broth, polyphosphates A and B inhibited the lytic cycle of only two bacteriophages at the maximal concentration used (0.5%), whereas in milk, they were not capable of maintaining the same inhibitory effect.


Author(s):  
Roseline Eleojo Kwasi ◽  
Iyanuoluwa Gladys Aremu ◽  
Qudus Olamide Dosunmu ◽  
Funmilola A. Ayeni

Background: Ogi constitutes a rich source of lactic acid bacteria (LAB) with associated health benefits to humans through antimicrobial activities. However, the high viability of LAB in Ogi and its supernatant (Omidun) is essential. Aims: This study was carried out to assess the viability of LAB in various forms of modified and natural Ogi and the antimicrobial properties of Omidun against diarrhoeagenic E coli. Methods and Material: The viability of LAB was assessed in fermented Ogi slurry and Omidun for one month and also freeze-dried Ogi with and without added bacterial strains for two months. A further 10 days viability study of modified Omidun, refrigerated Omidun, and normal Ogi was performed. The antimicrobial effects of modified Omidun against five selected strains of diarrhoeagenic E. coli (DEC) were evaluated by the co-culture method. Results: Both drying methods significantly affected carotenoids and phenolic compounds. The Ogi slurry had viable LAB only for 10 days after which, there was a succession of fungi and yeast. Omidun showed 2 log10cfu/ml reduction of LAB count each week and the freeze-dried Ogi showed progressive reduction in viability. Refrigerated Omidun has little viable LAB, while higher viability was seen in modified Omidun (≥2 log cfu/ml) than normal Omidun. Modified Omidun intervention led to 2-4 log reduction in diarrhoeagenic E. coli strains and total inactivation of shigella-toxin producing E. coli H66D strain in co-culture. Conclusions: The consumption of Ogi should be within 10 days of milling using modified Omidun. There are practical potentials of consumption of Omidun in destroying E. coli strains implicated in diarrhea. Keywords: Ogi, Omidun, lactic acid bacteria, diarrhoeagenic Escherichia coli strains, Viability.


Author(s):  
Reyhan Irkin ◽  
Nihal Yilmaz Ozgur ◽  
Nihal Tas

Lactic acid fermented vegetables are important sources of vitamins and minerals. In recent years consumers demand for non-dairy based functional products has increased. Cabbage pickle has high enough concentrations of fiber and also it may show health effect with the containing high numbers of lactic acid bacteria. The aim of this study is to optimize mathematically cabbage-carrot pickle fermentation for the viability of Lactobacillus acidophilus, Lactobacillus casei cultures and the sensory scores in brine with 5% and 7% (w/v) salt concentrations. Viability optimization of lactic acid bacteria is done via the notion of “fuzzy soft set” method. Lb. casei, Lb. acidophilus, total lactic acid bacteria, Enterobacteriaceae sp., yeast-mould counts and pH values have been reported during the 30 days of storage. The results are compared with the control traditional fermented cabbage-carrot pickle. Organoleptic properties are evaluated. We conclude that the fermented pickle samples contain a significant number of beneficial lactic acid bacteria and high sensory marks at the end of the storage.


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