Paracasei Subspecies Research Articles

Some lactobacillus, leuconostoc and acetobacter strains in traditional turkish yoghurt, cheese, kefir samples as a probiotic candidate

Lactic acid bacteria which are important for production of fermented milk products contain may strains called Lactobacillus, Streptococcus, Lactococcus and Leuconostoccus. As a result, lactic acid bacteria are called ‘milk-souring (fermenting)’ organisms. In addition to the fermentation abilities of Lactobacillus spp., it is important for aroma, texture and acid formation and comprises the most important group of lactic acid bacteria. Their critical importance comes from their metabolic capacity and probiotic features. In this research, yogurt, cheese and kefir samples were collected from cities in Turkey and used to isolate. Isolates were identified phenotypically and genotypically characterized. The probiotic features antibacterial activity against Staphylococcus aureus ATCC6538, Listeria monocytogenes DSM12464, Escherichia coli ATCC 25922, Enterococcus faecalis ATCC51299, and Salmonella Enteritidis ATCC 130762; bile and acid salt tolerance, susceptibility to chloramphenicol, erythromycin, penicillin G, gentamicin, vancomycin, streptomycin, kanamycin, and tetracycline of isolates were determined. Isolates, were identified as Lactobacillus paracasei subspecies (subsp.) paracasei, Lactobacillus delbrueckii subsp. bulgaricus, Acetobacter ghanensis, Acetobacter fabarum, Acetobacter subsp., Leuconostoc pseudomesenteroides, and Leuconostoc mesenteroides subsp. mesenteroides. Some isolates were tolerant of acid and bile salt, some strains were resistant to antibiotics, and some could inhibit pathogens. In this study, isolates were determined to have probiotic features. As a result of the study, it was determined that some isolates showed probiotic properties and had strong antibacterial activity. Isolates can be use as natural alternative in infections.

Characterization and Identification of Probiotic Features in Lacticaseibacillus Paracasei Using a Comparative Genomic Analysis Approach.

Lacticaseibacillus paracasei species are widely used for their health-promoting properties in food and agricultural applications. These bacteria have been isolated from various habitats such as the oral cavity, cereals, vegetables, meats, and dairy products conferring them the ability to consume different carbohydrates. Two subspecies are recognized, Lacticaseibacillus paracasei subsp. paracasei and Lacticaseibacillus paracasei subsp. tolerans according to their acid production from carbohydrates. Some strains are currently used as probiotics. In this study, we performed a comparative genomic analysis of 181 genomes of the Lacticaseibacillus paracasei species to reveal genomic differences at the subspecies level and to reveal adaptive and probiotic features, and special emphasis is given to inulin consumption. No clear distinction at the subspecies level for L. paracasei was shown using a phylogenetic tree with orthologous genes from the core-genome set. In general, a good correlation was observed between genomic distance and isolation origin, suggesting that L. paracasei strains are adapted to their natural habitat, giving rise to genetic differences at the genomic level. A low frequency of undesirable characteristics such as plasmids, prophages, antibiotic resistance genes, absence of virulence factors, and frequent bacteriocin production supports these species being good candidates for use as probiotics. Lastly, we found that the inulin gene cluster in L. paracasei strains seems to differ slightly in the presence or absence of some genes but maintains a core defined by at least three fructose-PTS proteins, one hypothetical protein, and extracellular β-fructosidase. Finally, we conclude that further work has to be done for L. paracasei subspecies classification. Improving outgroup selection criteria is a key factor for their correct subspecies assignation.

Brown seaweed Sargassum polycystum as dietary supplement exhibits prebiotic potentials in Asian sea bass Lates calcarifer fingerlings

Seaweeds are known to contain nutrients that are essential for human nutrition, making them edible and potential resources to mine for bioactive substances. The present study was aimed to investigate the prebiotic potentials of the seaweed, Sargassum polycystum as supplement in diets for Asia sea bass fingerlings. Experimental dietary formulations were supplemented with four graded levels of powdered seaweed (0.0, 1.5, 3.0 and 4.5 %) and fed to sea bass fingerlings (mean initial weight 2.2 g) for 55 days. Fish were evaluated for feed efficiency, growth performance and mortality. The results showed that survival, feed consumption and efficiency, and growth performance were better in fish fed the 1.5 and 3.0 % seaweed supplemented feed compared to the control. Carcass protein and Fe contents, red blood cell (RBC) and white blood cell (WBC) counts were also better in the fish fed the sargassum supplemented diets, which were significantly (p < 0.05) higher in the 1.5 and 3.0 % treatments than in the control. Proliferation of pure colonies of descendant Gram positive, none-spore forming, cocci and rod-shaped, catalase and oxidase negative bacteria was observed in the intestines of fish reared with the sargassum supplemented feed. These bacteria were identified as Lactobacillus paracasei subspecies paracasei, which were earlier identified to exhibit probiotic characteristics. Taken together, these results demonstrated the prebiotic potentials of sargassum, S. polycystum for Asian sea bass fingerling when supplemented in their diets at concentrations of between 15 and 30 g/kg. The commercial cultivation of sargassum seaweed needs to be encouraged.

Biofilm formation of Candida Spp. isolated from the vagina and antibiofilm activities of lactic acid bacteria on the these Candida Isolates.

In this study, it was aimed to investigate the effects of bacterial cells and cell-free filtrates of Lactobacillus acidophilus 8MR7 and Lactobacillus paracasei subspecies paracasei 10MR8 on the biofilm formation of 3 Candida tropicalis, 3 C. glabrata and 12 C. albicans isolated from the vagina and identified their virulence factors. Haemolytic activities esterase activities, and phospholipase activities as virulence factors of Candida strains were determined. Biofilm formations of these isolates were determined by Congo Red agar and microtitration plate method. Antibiofilm activities of bacterial cells and cell-free filtrates of L. acidophilus 8MR7 and L. paracasei subspecies paracasei 10MR8 on Candida isolates were determined by the microtitration plate method. Bacterial cells of L. acidophilus 8MR7 and L. paracasei subspecies paracasei 10MR8 were not very effective in the inhibition of biofilm, whereas it has been observed that the cell-free filtrates of these bacteria inhibit the formation of biofilms of Candida strains. Although the main mechanism for inhibiting the formation of Candida spp. biofilm is the competition for adhesion, it is concluded that the substances contained in the cell-free filtrates of lactic acid bacteria are also important. These isolates promise hope as potential bacteria that can be used for anti-adhesion purposes in health-care materials.

Melting curve analysis of a groEL PCR fragment for the rapid genotyping of strains belonging to the Lactobacillus casei group of species

Lactobacillus casei group (Lcs) consists of three phylogenetically closely related species (L. casei, L. paracasei, and L. rhamnosus), which are widely used in the dairy and probiotic industrial sectors. Strategies to easily and rapidly characterize Lcs are therefore of interest. To this aim, we developed a method according to a technique known as high resolution melting analysis (HRMa), which was applied to a 150bp groEL gene fragment. The analysis was performed on 53 Lcs strains and 29 strains representatives of species that are commonly present in dairy and probiotic products and can be most probably co-isolated with Lcs strains. DNA amplification was obtained only from Lcs strains, demonstrating the specificity of the groEL primers designed in this study. The HRMa clustered Lcs strains in three groups that exactly corresponded to the species of the L. casei group. A following HRMa separated the 39 L. paracasei strains in two well distinct intraspecific groups, indicating the possible existence of at least two distinct genotypes inside the species. Nonetheless, the phenotypic characterization demonstrated that the genotypes do not correspond to the two L. paracasei subspecies, namely paracasei and tolerans. In conclusion, the melting curve analysis developed in this study is demonstrably a simple, labor-saving, and rapid strategy obtain the genotyping of a bacterial isolate and simultaneously potentially confirm its affiliation to the L. casei group of species. The application of this method to a larger collection of strains may validate the possibility to use the proposed HRMa protocol for the taxonomic discrimination of L. casei group of species. In general, this study suggests that HRMa can be a suitable technique for the genetic typization of Lactobacillus strains.

An Influence of Pretreatment Conditions on Mutagen Binding of Lactobacillus paracasei subsp. tolerans JG22 against MNNG and 2-NF

Abstract The objectives of this study were to investigate theeffect of Lactobacillus paracasei subsp. tolerans JG22 isolatedfrom pepper leaf jangajji on the mutagenic activity of N-methyl,N'-nitro, N-nitrosoguanidine (MNNG) and 2-nitrofluene (2-NF)and to evaluate the effect of physico-chemical pretreatment on theantimutagenic activity of the strain. The viable cells of JG22 straindisplayed a significantly high (p <0.05) antimutagenic activityagainst both mutagens tested. The antimutagenic effect of JG22strain seems to be positively correlated with the amounts of thecells in the incubation time. This strain produced the antimutagenicactivity of the maximum levels after preincubation for 30 min.The binding of this strain against the mutagenic compounds mightbe mainly present in the cell wall fraction rather than the cytosolfraction. Pretreatment with proteolytic enzymes and simulatedgastric and intestinal juices and at different pH values had nosignificant effect on two mutagens removal by the viable cells.However, the binding activity of the mutagen by the strain seemsto be affected by heating, enzymes including α-amylase andlysozyme, divalent ions, and sodium metaperiodate. Thus,carbohydrates consisting of the cell walls may be importantelements responsible for the binding of MNNG and 2-NF by thisstrain. In conclusion, the binding of the mutagens to cells of JG 22strain may play a vital role in suppressing the process ofmutagenesis induced by mutagens.Keywords ames test · antimutagenic activity · Lactobacillus paracasei subspecies tolerans · mutagen bindingIntroductionA mutagen is an agent of substance that causes observablephenotypic changes of DNA such as nucleotide alteration andchromosomal aberration. There are three main types of mutagensclassifying by their sources: chemical (5-bromouracil, 2-aminopurine,etc.), biological (rubella and hepatitis B virus), and physical (highenergy radiation and UV light) mutagens (Kodym and Afza,2003). Among chemical mutagens, alkylating agent leads to cross-link DNA strands and chromosome breaks by two reactive alkylgroups. Deaminating agent converts amino groups to keto groupsand changes hydrogen-bonding potential through oxidativedeamination of amino groups in adenine, guanine, and cytosine.Intercalating agent such as acridine dyes increases rigidity andalters conformation of double helix and base analogs derivativesof the normal bases incorporated in DNA, altering base pairingproperties (Singer and Kusmierek, 1982). Many mutagens arisefrom cigarette smoke, automotive exhaust gas, X-ray irradiation,hazardous chemicals, cooking or food processing, (un)intentionaladditives, and environmental contaminants (Ferguson, 2002).Presence of mutagens is not only involved in the probability ofincidence for colorectal cancer but do also play a role in thepathogenesis of other chronic degenerative diseases, includingatherosclerosis and heart diseases (Gaubatz, 1997).According to previous report, the mutagenicity of direct andindirect mutagens was significantly decreased by probiotic strainsincluding Bifidibacterium ssp., Lactobacillus bulgaricus,Enterococcus faecium, and Streptococcus thermophilus thatshowed the greatest protective effect against DNA damage (Burnsand Rowland, 2004). Probiotics that provide numerous health-promoting effects mainly through improving intestinal microbialbalance of human and animal have been widely used intherapeutic applications (Gomes and Malcata, 1999). Severalreports clearly show that lactic acid bacteria (LAB) andbifidobacteria strains isolated from dairy products are able toreduce enzymatic activities relates to mutagen formation andinhibit the activity of mutagenic chemical compounds in in vivo as

Short communication: Influence of long-chain inulin and Lactobacillus paracasei subspecies paracasei on the sensory profile and acceptance of a traditional yogurt

The objectives of this study were to evaluate the influence of the addition of long-chain inulin as a fat replacer and prebiotic agent (20g/L) and (or) probiotic Lactobacillus paracasei ssp. paracasei on the sensory profile and acceptance of yogurts, and to assess the influence of descriptive attributes on the sensory acceptance of the products. The addition of inulin to low-fat yogurt improved its brightness and firmness, which was similar to the full-fat yogurt. However, the use of long-chain inulin increased the separation of serum and no influence on creaminess was observed. Regarding the product’s acceptability, the low-fat yogurt with added inulin presented similar acceptance compared with the full-fat yogurt. The addition of Lb. paracasei ssp. paracasei did not affect the sensory profile and acceptance of the low-fat yogurt. Using external preference mapping, it was possible to verify that the sensory acceptance was driven positively by the sweetness and creaminess and negatively driven by firmness (appearance and texture) and homogeneity (appearance). It was possible to formulate low-fat yogurts with added probiotics that presented similar sensory characteristics to those of full-fat yogurts, and this was due to the addition of the long-chain inulin as a fat replacer.

The investigation of probiotic potential of lactic acid bacteria isolated from traditional Mongolian dairy products

The aims of this study were to investigate the diversity of lactic acid bacteria (LAB) isolated from traditional Mongolian dairy products, and to estimate the probiotic potential of the isolated strains. We collected 66 samples of the traditional Mongolian dairy products tarag (n = 45), airag (n = 7), aaruul (n = 8), byasulag (n = 1) and eezgii (n = 5), from which 543 LAB strains were isolated and identified based on 16S ribosomal DNA sequence. The predominant species of those products were Lactobacillus (L.) delbrueckii ssp. bulgaricus, L. helveticus, L. fermentum, L. delbrueckii ssp. lactis and Lactococcus lactis ssp. lactis. However, we could not detect any LAB strains from eezgii. All LAB isolates were screened for tolerance to low pH and to bile acid, gas production from glucose, and adherence to Caco-2 cells. In vitro, we found 10 strains possess probiotic properties, and almost identified them as L. plantarum or L. paracasei subspecies, based on 16S ribosomal DNA and carbohydrate fermentation pattern. These strains were differentiated from each other individually by randomly amplified polymorphic DNA analysis. Additionally, it was notable that 6/10 strains were isolated from camel milk tarag from the Dornogovi province.

Evaluation of a diet free of animal protein in germfree swine

Two experiments were conducted in which germfree pigs or pigs monoassociated with Lactobacillus paracasei subspecies paracasei were fed either a traditional milk-based diet (Esbilac) or an experimental diet free of animal protein (DFAP). Throughout the 16-day study, animals' clinical condition, total weight gain, feed conversion, and bacterial contamination were monitored. At the conclusion of the study the animals were killed, necropsied and tissues sampled for L. paracasei isolation. General pig disposition remained consistent between treatment groups and trials, except for two animals that developed mild diarrhoea during trial 1. All pigs remained viable during the study irrespective the diet fed or probiotic inoculation. Germfree pigs fed the Esbilac diet gained on average a total of 1034 +/- 63.0 g, and had a feed conversion ratio of 0.17 +/- 0.01 g of gain per 1 ml of diet. Germfree pigs fed the experimental diet gained on average a total of 599 +/- 151 g, and had a feed conversion ratio of 0.10 +/- 0.02 g of gain per 1 ml of diet. Monoassociated pigs fed the Esbilac diet gained on average a total of 862 +/- 70.3 g, and had a feed conversion ratio 0.14 +/- 0.01 g of gain per 1 ml of diet. Monoassociated pigs fed the experimental diet gained on average a total of 563 +/- 96.8 g, and had a feed conversion ratio of 0.09 +/- 0.02 g of gain per 1 ml of diet. Lactobacillus paracasei established extensively in pigs fed either the Esbilac or experimental diets. Lactobacillus paracasei had no effect (P >0.05) on piglet growth and did not display any interactions based on the diet fed. Measured growth parameters were statistically different (P <0.05) based on the diet fed and variance seen between trials. In conclusion, a DFAP has been developed and has been shown to be capable of sustaining life in piglets up to 16 days of age.