scholarly journals Water Kefir grain as a source of potent dextran producing lactic acid bacteria

2015 ◽  
Vol 69 (6) ◽  
pp. 595-604 ◽  
Author(s):  
Sladjana Davidovic ◽  
Miona Miljkovic ◽  
Dusan Antonovic ◽  
Mirjana Rajilic-Stojanovic ◽  
Suzana Dimitrijevic-Brankovic

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.

2001 ◽  
Vol 64 (4) ◽  
pp. 559-563 ◽  
Author(s):  
ROXANA MEDINA ◽  
MARTA KATZ ◽  
SILVIA GONZALEZ ◽  
GUILLERMO OLIVER

Indigenous lactic acid bacteria in ewe's milk and artisanal cheese were studied in four samples of fresh raw milk and four 1-month-old cheeses from the provinces of northwest Argentina. Mean growth counts on M17, MRS, and MSE agar media did not show significant differences (P < 0.05) in raw milk and cheeses. Isolates of lactic acid bacteria from milk were identified as Enterococcus (48%), lactococci (14%), leuconostocs (8%), and lactobacilli (30%). All lactococci were identified as Lactococcus lactis (subsp. lactis and subsp. cremoris). Lactobacilli were identified as Lactobacillus plantarum (92%) and Lactobacillus acidophilus (8%). Enterococci (59%) and lactobacilli (41%) were isolated from cheeses. L. plantarum (93%), L. acidophilus (5%), and Lactobacillus casei (2%) were most frequently isolated. L. lactis subsp. lactis biovar diacetylactis strains were considered as fast acid producers. L. lactis subsp. cremoris strains were slow acid producers. L. plantarum and L. casei strains identified from the cheeses showed slow acid production. The majority of the lactobacilli and Lactococcus lactis strains utilized citrate and produced diacetyl and acetoin in milk. Enzyme activities (API-ZYM tests) of lactococci were low, but activities of L. plantarum strains were considerably higher. The predominance of L. plantarum in artisanal cheese is probably important in the ripening of these cheeses due to their physiological and biochemical characteristics.


2020 ◽  
Vol 367 (8) ◽  
Author(s):  
Pietro Barbaccia ◽  
Nicola Francesca ◽  
Rosalia Di Gerlando ◽  
Gabriele Busetta ◽  
Giancarlo Moschetti ◽  
...  

ABSTRACT The present work was developed to select lactic acid bacteria (LAB) to be used as starter cultures in functional cheese production. The indigenous milk LAB populations were isolated from fermented raw ewes’ milks (four bulks) added with 0.5 mg/mL of nine polyphenols commonly found in winery by-products. After 48 h of fermentation, all milks were characterized by an increase of LAB levels of about 3–4 Log cycles. All different colonies were purified and characterized for the main physiological and biochemical traits and then differentiated genetically at strain level and identified. Ten species belonging to the LAB genera Lactobacillus, Streptococcus, Enterococcus, Leuconostoc and Lactococcus were identified. Only Lactococcus lactis and Leuconostoc mesenteroides strains were evaluated for the technological traits including acidification and autolytic kinetics, diacetyl formation, exopolysaccharide production and generation of antimicrobial compounds. A total of four strains (Mise36, Mise94 Mise169 and Mise190) belonging to Lc. lactis displayed potential for production of cheeses containing grape polyphenols.


2002 ◽  
Vol 28 (1) ◽  
pp. 1-6 ◽  
Author(s):  
E Simova ◽  
D Beshkova ◽  
A Angelov ◽  
Ts Hristozova ◽  
G Frengova ◽  
...  

2021 ◽  
Vol 9 (5) ◽  
pp. 1044
Author(s):  
Jeong A Kim ◽  
Geun Su Kim ◽  
Se Mi Choi ◽  
Myeong Seon Kim ◽  
Do Young Kwon ◽  
...  

Hardening of cheese is one of major issues that degrade the quality of Home Meal Replacement (HMR) foods containing cheese such as Cheese-ddukbokki rice cake (CD, stir-fried rice cakes with shredded cheese). The quality of cheese, such as pH, proteolytic, and flavor properties, depends on various lactic acid bacteria (LAB) used in cheese fermentation. The hardening of cheese is also caused by LAB. In this study, various LAB strains were isolated from CD samples that showed rapid hardening. The correlation of LAB with the hardening of cheese was investigated. Seven of the CD samples with different manufacturing dates were collected and tested for hardening properties of cheese. Among them, strong-hardening of cheese was confirmed for two samples and weak-hardening was confirmed for one sample. All LAB in two strong-hardening samples and 40% of LAB in one weak-hardening sample were identified as Latilactobacillus curvatus. On the other hand, most LAB in normal cheese samples were identified as Leuconostoc mesenteroides and Lactobacillus casei. We prepared cheese samples in which L. curvatus (LC-CD) and L. mesenteroides (LM-CD) were most dominant, respectively. Each CD made of the prepared cheese was subjected to quality test for 50 days at 10 °C. Hardening of cheese with LC-CD dominant appeared at 30 days. However, hardening of cheese with LM-CD dominant did not appear until 50 days. The pH of the LC-CD was 5.18 ± 0.04 at 30 days, lower than that of LM-CD. The proteolytic activity of LC-CD sample was 2993.67 ± 246.17 units/g, higher than that of LM-CD sample (1421.67 ± 174.5 units/g). These results indicate that high acid production and high protease activity of L. curvatus might have caused hardening of cheese.


2021 ◽  
pp. 1-7
Author(s):  
Harutoshi Tsuda ◽  
Kana Kodama

Abstract This paper reveals the technological properties of lactic acid bacteria isolated from raw milk (colostrum and mature milk) of Wagyu cattle raised in Okayama Prefecture, Japan. Isolates were identified based on their physiological and biochemical characteristics as well as 16S rDNA sequence analysis. Streptococcus lutetiensis and Lactobacillus plantarum showed high acid and diacetyl-acetoin production in milk after 24 h of incubation at 40 and 30°C, respectively. These strains are thought to have potential for use as starter cultures and adjunct cultures for fermented dairy products.


2017 ◽  
Vol 55 (4) ◽  
pp. 296-303 ◽  
Author(s):  
Young-Joo Yi ◽  
Jeong-Muk Lim ◽  
Suna Gu ◽  
Wan-Kyu Lee ◽  
Eunyoung Oh ◽  
...  

1971 ◽  
Vol 34 (11) ◽  
pp. 521-525 ◽  
Author(s):  
J. R. Stamer ◽  
B. O. Stoyla ◽  
B. A. Dunckel

The effects of pH values and NaCl concentrations on the growth rates of five species of lactic acid bacteria commonly associated with the sauerkraut fermentation were determined in filter-sterilized cabbage juice. Growth rates of all cultures, with the exception of Pediococcus cerevisiae, were retarded by addition of salt, lower pH, or interaction of both pH and salt. Based upon lag and generation times, P. cerevisiae was the culture most tolerant to the pH and salt concentration employed, whereas Streptococcus faecalis was the most sensitive species. Of the heterofermentative cultures, Lactobacillus brevis was less subject to growth inhibition than Leuconostoc mesenteroides. Under conditions simulating those found during the initial phases of the sauerkraut fermentation (2.25% salt, pH 6.2), L. mesenteroides displayed the shortest lag and generation times of all cultures examined. This rapid growth rate coupled with a marked accelerated death rate may explain, in part, the reason this species is both the first to dominate and the first to die during the early phases of the sauerkraut fermentation. Although cabbage juice previously fermented by L. mesenteroides appears to inhibit growth of P. cerevisiae, it had no apparent inhibitory or stimulatory effects on the other cultures.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Manel Ziadi ◽  
Taroub Bouzaiene ◽  
Sana M’Hir ◽  
Kaouther Zaafouri ◽  
Ferid Mokhtar ◽  
...  

Exopolysaccharides (EPS) produced by three Lactic Acid Bacteria strains,Lactococcus lactisSLT10,Lactobacillus plantarumC7, andLeuconostoc mesenteroidesB3, were isolated using two methods: ethanol precipitation (EPS-ETOH) and ultrafiltration (EPS-UF) through a 10 KDa cut-off membrane. EPS recovery by ultrafiltration was higher than ethanol precipitation forLactococcus lactisSLT10 andLactobacillus plantarumC7. However, it was similar with both methods forLeuconostoc mesenteroidesB3. The monomer composition of the EPS fractions revealed differences in structures and molar ratios between the two studied methods. EPS isolated fromLactococcus lactisSLT10 are composed of glucose and mannose for EPS-ETOH against glucose, mannose, and rhamnose for EPS-UF. EPS extracted fromLactobacillus plantarumC7 andLeuconostoc mesenteroidesB3 showed similar composition (glucose and mannose) but different molar ratios. The molecular weights of the different EPS fractions ranged from 11.6±1.83 to 62.4±2.94 kDa. Molecular weights of EPS-ETOH fractions were higher than those of EPS-UF fractions. Fourier transform infrared (FTIR) analysis revealed a similarity in the distribution of the functional groups (O-H, C-H, C=O, -COO, and C-O-C) between the EPS isolated from the three strains.


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