Characterization and emended description of Lactobacillus kunkeei as a fructophilic lactic acid bacterium

2012 ◽  
Vol 62 (Pt_3) ◽  
pp. 500-504 ◽  
Author(s):  
Akihito Endo ◽  
Tomohiro Irisawa ◽  
Yuka Futagawa-Endo ◽  
Katsumi Takano ◽  
Maret du Toit ◽  
...  

Lactobacillus kunkeei is an inhabitant of fructose-rich niches and is a potential member of the fructophilic lactic acid bacteria. In the present study, the phylogenetic and biochemical characteristics of the type strain and eight isolates of L. kunkeei, originating from wine, flowers and honey, were studied. The nine isolates, including the type strain, formed a well-defined phylogenetic subcluster based on the analysis of 16S rRNA gene sequences. The subcluster was not closely related to other subclusters in the Lactobacillus phylogenetic group. Biochemically, the eight new isolates showed typical fructophilic characteristics. The eight isolates grew poorly on glucose, but grew well on fructose. Good growth on glucose was only recorded in the presence of electron acceptors. The type strain of L. kunkeei differed from the other isolates only on the basis of poor growth on fructose. Although they belong to a group of obligately heterofermentative lactic acid bacteria, all nine isolates, including the type strain, produced almost equimolar amounts of lactic acid and acetic acid and very little ethanol from glucose. Eight of the isolates can thus be regarded as typical ‘obligately’ fructophilic lactic acid bacteria. Although the type strain of L. kunkeei was phenotypically slightly different from the other isolates, it possessed several important fructophilic characteristics. On the basis of the evidence gathered in this study, the type strain of L. kunkeei is recognized as a member of the ‘obligately’ fructophilic lactic acid bacteria.

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 ◽  
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.


1956 ◽  
Vol 23 (1) ◽  
pp. 120-125 ◽  
Author(s):  
J. Czulak ◽  
Jill Naylor

A lysogenic culture, prepared in the laboratory from a strain of Streptococcus lactis, was used as a cheese starter in commercial factories. It was attacked in turn by two other unrelated phage races. The lysogenic condition, which involved slight morphological and physiological changes, persisted in the subsequent forms resistant to one or both the new phage races. Acquired resistance to any one of the three phages did not protect the culture from the other two phages.In nature such interactions between phage races and lactic acid bacteria must be constantly taking place, giving rise to similarly related strains.Two of the three phage races produced spreading haloes around their plaques due to a lysin released during phage action. The lysin may also interfere with the survival of secondary growth after attack by these phage races. Production of this type of lysin is thus a property of the phage race and not of the bacterial strain.


2011 ◽  
Vol 61 (8) ◽  
pp. 1954-1961 ◽  
Author(s):  
An Coorevits ◽  
Niall A. Logan ◽  
Anna E. Dinsdale ◽  
Gillian Halket ◽  
Patsy Scheldeman ◽  
...  

A polyphasic taxonomic study was performed on 22 thermotolerant, aerobic, endospore-forming bacteria from dairy environments. Seventeen isolates were retrieved from raw milk, one from a filter cloth and four from grass, straw or milking equipment. These latter four isolates (R-6546, R-7499, R-7764 and R-7440) were identified as Bacillus thermoamylovorans based on DNA–DNA hybridizations (values above 70 % with Bacillus thermoamylovorans LMG 18084T) but showed discrepancies in characteristics with the original species description, so an emended description of this species is given. According to 16S rRNA gene sequence analysis and DNA–DNA hybridization experiments, the remaining 18 isolates (R-6488T, R-28193, R-6491, R-6492, R-7336, R-33367, R-6486, R-6770, R-31288, R-28160, R-26358, R-7632, R-26955, R-26950, R-33520, R-6484, R-26954 and R-7165) represented one single species, most closely related to Bacillus thermoamylovorans (93.9 % 16S rRNA gene sequence similarity), for which the name Bacillus thermolactis is proposed. Cells were Gram-stain-positive, facultatively anaerobic, endospore-forming rods that grew optimally at 40–50 °C. The cell wall peptidoglycan type of strain R-6488T, the proposed type strain, was A1γ based on meso-diaminopimelic acid. Major fatty acids of the strains were C16 : 0 (28.0 %), iso-C16 : 0 (12.1 %) and iso-C15 : 0 (12.0 %). MK-7 was the predominant menaquinone, and major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and some unidentified phospholipids. DNA G+C content was 35.0 mol%. Phenotypic properties allowed discrimination from other thermotolerant species of the genus Bacillus and supported the description of the novel species Bacillus thermolactis, with strain R-6488T ( = LMG 25569T  = DSM 23332T) as the proposed type strain.


Author(s):  
Jinghui Yao ◽  
Jing Gao ◽  
Jianming Guo ◽  
Hengan Wang ◽  
En Zhang ◽  
...  

The consumption of cheese in China is increasing rapidly. Little is known about the microbiota, the presence of antibiotic-resistant bacteria, or the distribution of antibiotic resistance genes (ARGs) in commercially-produced cheeses sold in China. These are important criteria for evaluating quality and safety. Thus, this study assessed the metagenomics of fifteen types of cheese using 16S rRNA gene sequencing. Fourteen bacterial genera were detected. Lactococcus , Lactobacillus , and Streptococcus were dominant based on numbers of sequence reads. Multidrug-resistant lactic acid bacteria were isolated from most of the types of cheese. The isolates showed 100% and 91.7% resistance to streptomycin and sulfamethoxazole, respectively, and genes involved in acquired resistance to streptomycin ( strB) and sulfonamides ( sul2) were detected with high frequency. To analyze the distribution of ARGs in the cheeses in overall, 309 ARGs from eight categories of ARG and nine transposase genes were profiled. A total of 169 ARGs were detected in the 15 cheeses; their occurrence and abundance varied significantly between cheeses. Our study demonstrates that there is various diversity of the bacteria and ARGs in cheeses sold in China. The risks associated with multidrug resistance of dominant lactic acid bacteria are of great concern.


2020 ◽  
Vol 8 (10) ◽  
pp. 1578 ◽  
Author(s):  
Massimo Iorizzo ◽  
Gianfranco Pannella ◽  
Silvia Jane Lombardi ◽  
Sonia Ganassi ◽  
Bruno Testa ◽  
...  

Lactic acid bacteria could positively affect the health of honey bees, including nutritional supplementation, immune system development and pathogen colonization resistance. Based on these considerations the present study evaluated predominant Lactic Acid Bacteria (LAB) species from beebread as well as from the social stomach and midgut of Apis mellifera ligustica honey bee foragers. In detail, for each compartment, the diversity in species and biotypes was ascertained through multiple culture-dependent approaches, consisting of Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE), 16S rRNA gene sequencing and Randomly Amplified Polymorphic DNA-Polymerase Chain Reaction (RAPD-PCR). The study of a lactic acid bacteria community, performed with PCR-DGGE and sequence analysis targeting the V1–V3 region of the 16S rRNA gene (rDNA), highlighted the presence of a few species, including Apilactobacillus kunkeei, Lactiplantibacillus plantarum, Fructobacillus fructosus, Levilactobacillus brevis and Lactobacillus delbrueckii subsp. lactis. Depending on the different compartments, diverse levels of biodiversity in species were found. Particularly, a very low inter-species biodiversity was detected in the midgut that was prevalently dominated by the presence of Apilactobacillus kunkeei. On the other hand, the beebread was characterized by a reasonable biodiversity showing the presence of five species and the predominance of Apilactobacillus kunkeei, Lactiplantibacillus plantarum and Fructobacillus fructosus. The RAPD-PCR analysis performed on the three predominant species allowed the differentiation into several biotypes for each species. Moreover, a relationship between biotypes and compartments has been detected and each biotype was able to express a specific biochemical profile. The biotypes that populated the social stomach and midgut were able to metabolize sugars considered toxic for bees while those isolated from beebread could contribute to release useful compounds with functional properties. Based on this knowledge, new biotechnological approaches could be developed to improve the health of honey bees and the quality of bee products.


2007 ◽  
Vol 57 (8) ◽  
pp. 1788-1792 ◽  
Author(s):  
Jung-Hoon Yoon ◽  
So-Jung Kang ◽  
Mi-Hwa Lee ◽  
Tae-Kwang Oh

A Gram-negative, non-motile and rod-, oval- or coccoid-shaped bacterial strain, DSW-25T, which is phylogenetically closely related to the genera Staleya and Sulfitobacter, was isolated from seawater of the East Sea, Korea, and subjected to a polyphasic taxonomic study. Strain DSW-25T grew optimally at pH 7.0–8.0 and at 25 °C. It contained Q-10 as the predominant ubiquinone and C18 : 1 ω7c as the major fatty acid. Major polar lipids were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine and an unidentified phospholipid. The DNA G+C content was 56.9 mol%. Strain DSW-25T exhibited 16S rRNA gene sequence similarity values of 98.4 % to the type strain of Staleya guttiformis and of 96.6–97.6 % to Sulfitobacter species. There were no distinct phenotypic, particularly chemotaxonomic, properties to differentiate Staleya guttiformis and strain DSW-25T from the genus Sulfitobacter. DNA–DNA relatedness data and differential phenotypic properties, together with the phylogenetic distinctiveness, demonstrated that strain DSW-25T differs from recognized Sulfitobacter species and Staleya guttiformis. On the basis of phenotypic, chemotaxonomic, phylogenetic and genetic data, strain DSW-25T was classified in the genus Sulfitobacter as a member of a novel species, for which the name Sulfitobacter donghicola sp. nov. is proposed. The type strain is strain DSW-25T (=KCTC 12864T =JCM 14565T). It is also proposed that Staleya guttiformis be transferred to the genus Sulfitobacter as Sulfitobacter guttiformis comb. nov.


2011 ◽  
Vol 61 (4) ◽  
pp. 722-727 ◽  
Author(s):  
Se Hee Lee ◽  
Jae Kuk Shim ◽  
Jeong Myeong Kim ◽  
Hyung-Kyoon Choi ◽  
Che Ok Jeon

A Gram-staining-negative, strictly aerobic bacterium, designated strain SD10T, was isolated from a tidal flat of the Yellow Sea, South Korea. Cells were non-spore-forming rods that showed catalase- and oxidase-positive reactions. Growth of strain SD10T was observed at 15–40 °C (optimum, 25–30 °C), at pH 6.0–9.0 (optimum, pH 6.5–8.5) and in the presence of 1–10 % (w/v) NaCl. Strain SD10T contained ubiquinone-10 (Q-10) as a major isoprenoid quinone and C18 : 1ω7c (39.3 %), C16 : 0 (20.2 %), C17 : 0 (8.9 %) and C17 : 1ω6c (8.1 %) as major fatty acids. The cellular polar lipids were identified as phosphatidylglycerol, monoglycosyldiglyceride, glucuronopyranosyldiglyceride and two unidentified glycolipids. The G+C content of the genomic DNA was 55.2 mol%. Based on 16S rRNA gene sequence similarities, the strain was most closely related to Henriciella marina Iso4T and Maribaculum marinum P38T, with similarities of 97.8 and 97.0 %, respectively. The DNA–DNA relatedness between strain SD10T and H. marina Iso4T was 12.0±3.2 %. A phylogenetic analysis based on 16S rRNA gene sequences showed that M. marinum P38T and H. marina Iso4T formed a monophyletic cluster and that their 16S rRNA gene sequence similarity was 98.1 %. DNA–DNA hybridization between H. marina Iso4T and M. marinum LMG 24711T was 22.9±2.7 %, indicating that the two strains belong to separate species. On the basis of chemotaxonomic data and molecular properties, we propose that strain SD10T represents a novel species of the genus Henriciella, for which the name Henriciella litoralis sp. nov. is proposed. The type strain is SD10T ( = KACC 13700T  = DSM 22014T). In addition, we propose to transfer Maribaculum marinum Lai et al. 2009 to the genus Henriciella as Henriciella aquimarina nom. nov. (type strain P38T  = CCTCC AB 208227T  = LMG 24711T  = MCCC 1A01086T), and we present an emended description of the genus Henriciella.


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