Leuconostoc Paramesenteroides Research Articles

Isolation And Characteristics Of Lactic Acid Bacteria In Feces Of Jember Local Mongoose

Drinking a cup of coffee is not only a matter of taste but also a part of Indonesian’s daily life. Coffee shops which have proliferated so far proves this lifestyle. One of the best selling coffee bean products is mongoose coffee. It is a product of coffee beans which have been swallowed by mongoose and through its digestive tract. In the digestive tract, beans are being fermented by microbes (lactic acid bacteria or LAB). This fermentation process contributes to the unique taste and aroma of the coffee. The taste and aroma are very appealing to coffee lovers, resulting in the rise of demands in both local and international markets in every year. However, this leads to the escalation of mongoose hunting, threatening the population of mongoose (Paradoxurus hermaphroditus). Moreover, its limited digesting capacity also hinders the production of mongoose coffee. The present study offers an alternative to produce mongoose coffee by optimizing in-vitro fermentation which simulates the natural process of fermentation inside mongoose’s digestive organs. This in-vitro fermentation uses bacteria isolate (LAB) from mongoose’s feces collected from the local society of Jember. The study, therefore, aimed to: 1) isolate LAB from mongoose’s feces, and 2) identify the characteristics of collected LAB. Based on the result of data analysis, it was concluded that 5 LAB isolates from local mongoose’s feces were identified, namely: LAB-1 is Lactobacillus plantarum, LAB-2 is Lactobacillus brevis, LAB-3 is Leuconostoc paramesenteroides, LAB-4 is Leuconostoc mesenteroides, and LAB-5 is Streptococcus faecium

The effects of multispecies probiotic formulations on growth performance, hepatic metabolism, intestinal integrity and fecal microbiota in growing-finishing pigs

Probiotics have received attention as alternatives to antibiotics due to their relative biosafety. Despite the health-promoting effects of multispecies probiotic formulation (MPF) in weaning pigs were well-documented, the health-promoting potential of MPF in growing-finishing pigs remain limited. Therefore, we conducted a six-week experiment to investigate the beneficial effects of MPF supplementation (the formulations containing Lactobacillus plantarum CJLP243, L. fermentum LF21, L. salivarius E4101, Leuconostoc paramesenteroides KJP421, Bacillus subtilis CJMPB957 and B. licheniformis CJMPB283) on intestinal environments and hepatic lipid metabolism in growing-finishing pigs. The results showed that the growth performance of MPF group was improved compared to control group during the experimental period without affecting feed intake. The dietary MPF supplementation also significantly increased the jejunal mRNA expression levels of zonula occludens-1 (ZO-1) and decreased that of interleukin-12 (IL-12). Dietary MPF supplementation was found to not only reduce the hepatic triglyceride concentration but down-regulate hepatic mRNA expression levels of lipid metabolism-related markers, such as as sterol regulatory element-binding transcription factor 1c (SREBP-1c), CCAAT/enhancer binding protein α (CEBPα), acetyl coA carboxylase (ACC) and carnitine palmitoyl transferase 1β (CPT1β). Nonetheless, MPF supplementation also had the capability to modulate gut microbiota populations, including Clostridiaceae, Lachnospiraceae, and Turicibacter. Collectively, our results suggest that dietary MPF inclusion could be a promising approach to promote the growth performance and the overall health of growing-finishing pigs via modulation of gut microbiota.

Lactobacillus curvatus KFP419 and Leuconostoc mesenteroides subsp. mesenteroides KDK411 Isolated from Kimchi Ameliorate Hypercholesterolemia in Rats.

Western-style diets increase the risk for cardiovascular diseases. It is suggested that the risk could be prevented by lowering cholesterol concentrations in blood. In the present study, hypocholesterolemic effects of the probiotics isolated from kimchi (Lactobacillus curvatus KFP419, Leuconostoc paramesenteroides KJP421, and Leuconostoc mesenteroide subsp. mesenteroides KDK411) were investigated in hypercholesterolemia-induced rats. There was no difference in growth performance between the rats fed high cholesterol diet (HCD) and normal diet (ND). However, blood total cholesterol, low-density lipoprotein cholesterol, and hepatic cholesterol were elevated by the HCD compared to ND, and those concentrations were decreased by dietary supplementation of KFP419 and KDK411. It was concomitant with an increase in fecal excretion of neutral sterols (cholesterol, coprostanol, and coprostanone) in the rats fed HCD compared to ND and was even greater with KDK411 supplementation. These findings indicate that probiotics L. curvatus KFP419 and L. mesenteroide subsp. mesenteroides KDK411 isolated from kimchi ameliorate hypercholesterolemia in rats by assimilating and excreting cholesterol in feces.

Taxonomic Status of Lactic Acid Bacteria in Wine and Key Characteristics to Differentiate Species

Oenococcus oeni is the best malolactic bacterium adapted to low pH and the high SO2 and ethanol concentrations in wine. Leuconostoc mesenteroides and Leuconostoc paramesenteroides (now classified as Weissella paramesenteroides) have also been isolated from wine. Pediococcus damnosus is not often found in wine and is considered a contaminant of high pH wines. Pediococcus inopinatus, Pediococcus parvulus and Pediococcus pentosaceus have occasionally been isolated from wines. Lactobacillus brevis, Lactobacillus plantarum, Lactobacillus buchneri, Lactobacillus hilgardii (previously Lactobacillus vermiforme), Lactobacillus fructivorans (previously Lactobacillus trichoides and Lactobacillus heterohiochii) and Lactobacillus fermentum have been isolated from most wines. Lactobacillus hilgardii and L. fructivorans are resistant to high acid and alcohol and have been isolated from spoiled fortified wines. Lactobacillus vini, Lactobacillus lindneri, Lactobacillus nagelii and Lactobacillus kunkeei have been described more recently. The latter two species are known to cause sluggish or stuck alcoholic fermentations in wine. Although Lactobacillus collinoides and Lactobacillus mali (previously Lactobacillus yamanashiensis) decarboxylate L-malic acid, they are more often found in cider and fruit juices. Lactobacillus curvatus, Lactobacillus delbrueckii, Lactobacillus diolivorans, Lactobacillus jensenii and Lactobacillus paracasei are seldomly isolated from wines. Some strains of Lactobacillus casei may be closer related to Lactobacillus paracasei or a distant relative, Lactobacillus zeae. Oenococcus kitaharae, isolated from compost is genetically closely related to Oenococcus oeni, but does not decarboxylate malate, prefers higher growth pH and is phenotypically well distinguished from O. oeni. This review summarises the current taxonomic status of malolactic bacteria and lists key phenotypic characteristics that may be used to identify the species.

Genomics of Weissella cibaria with an examination of its metabolic traits.

Weissella is a genus of lactic acid bacteria (LAB) consisting of species formerly included in the Leuconostoc paramesenteroides group. Similar to other LAB, they are commonly found in fermented foods but have also been isolated from environmental and human samples. Currently there are 20 recognized species. Herein, three Weissella cibaria genomes were sequenced using Illumia Mi-Seq and Roche 454 technologies. Annotation was performed using the Prokka and JGI IMG pipelines. A thorough analysis of the genomics of the W. cibaria strains was performed, in addition to brief comparative analyses of the genus Weissella as a whole. Genomic sequence data from the newly sequenced W. cibaria strains and data available in GenBank for other Weissella strains was used (n = 10; four Weissella cibaria, one Weissella ceti, one Weissella confusa, one Weissella halotolerans, two Weissella koreensis and one Weissella paramesenteroides). The genomes had sizes varying from 1.3 to 2.4 Mb. DNA G+C contents ranged from 35 to 45 mol%. The core- and pan-proteome at genus and species levels were determined. The genus pan-proteome was found to comprise 4712 proteins. Analysis of the four W. cibaria genomes indicated that the core-proteome, consisting of 729 proteins, constitutes 69 % of the species pan-proteome. This large core-set may explain the divergent niches in which this species has been found. In W. cibaria, in addition to a number of phosphotransferase systems conferring the ability to assimilate plant-associated polysaccharides, an extensive proteolytic system was identified.

Answer to March 2015 Photo Quiz

Answer: Weissella confusa. The diagnosis of bacteremia due to Weissella confusa was confirmed by 16S rRNA gene sequencing. The organism, based on the production of alpha-hemolysis, the Gram stain, and the catalase-negative reaction, was preliminarily reported as “Lactobacillus-like, identification to follow.” Repeat blood cultures were subsequently negative after removal of the peripherally inserted central catheter (PICC) and therapy switch from vancomycin to daptomycin. We believe that her bacteremia was related to the indwelling PICC, total parenteral nutrition (TPN) dependency, and the history of altered gut flora with multiple abdominal surgeries. W. confusa is a nonmotile Gram-positive, alpha-hemolytic, catalase-negative coccobacillus that grows at 25, 35, and 42°C and is positive for esculin hydrolysis and arginine deamination (1). Originally identified as Lactobacillus confusus, the organism was reclassified into a novel genus in 1993 along with other lactobacilli and Leuconostoc paramesenteroides (2). Thus, this organism is frequently confused with Lactobacillus- or Leuconostoc-like organisms, which are inherently vancomycin resistant and often considered contaminants (3, 4). W. confusa has been isolated from sugar cane, carrot juice, milk, fermented cereals, and vegetables (5). Though an exceedingly rare human pathogen and usually nonfatal, W. confusa has been demonstrated to cause clinical disease such as abscess, bacteremia, prosthetic joint infection, and infective endocarditis (4, 6, 7, 8). Immunocompromised states, prior exposure to vancomycin, altered gut flora, recent gastrointestinal procedures, and TPN dependency are all suspected to be risk factors for the development of Lactobacillus species bacteremia (4). Due to the rarity of W. confusa, the Clinical and Laboratory Standards Institute (CLSI) has not established breakpoints for susceptibility testing. However, based on MICs, the preferred therapy includes penicillin, clindamycin, erythromycin, aminoglycosides, and imipenem (6). Daptomycin has also been shown to have activity, as was the case with our patient's isolate, which had a daptomycin MIC of 0.38 μg/ml by Etest (3). Though a rare entity, W. confusa should be considered for any patient presenting with bacteremia caused by a Gram-positive organism and underlying risk factors for infection with Lactobacillus species. Since vancomycin is the empirical first-line therapy for bacteremia caused by a Gram-positive organism, early consideration of this organism is important due to its inherent vancomycin resistance, which necessitates alternative therapy. (See page 759 in this issue [doi:10.1128/JCM.00941-13] for photo quiz case presentation.)

Isolation and Identification of Yeasts and Lactic Acid Bacteria from Local Traditional Fermented Camel Milk, Chal

The yeasts and lactic acid bacteria in samples of the Iranian traditional fermented camel milk, Chal were identified on the basis of physiological and morphological properties. Yeast species were identified including Pichia. anamala, Pichia. jadinii, Debaryomyces. hansenii, Pichia. guilliermondii, Kluyvermyces. marxianus, Candida. fermentati, Pichia. ciferrii, Torulospora. delbrueckii, Candida. versatilis, Kluyvermyces. lactis, Candida. kefir, Saccharomyces. pastorianus, Saccharomyces. serevisiae, Candida. friedrichii, Kluyvermyces. polysporus, Rhodotorula. musilaginosa, Candida. lipolytica and Candida. lusitaniae. All of them could assimilate the glucose and liquefacted the gelatin, but could not production starch, tolerated 1% acetic acid, growth in the presence of Nacl 16% (except Debaryomyces. hansenii), anassimilateed the nitrat (except Rhodotorula. musilaginosa). Within the yeasts species, Kluyvermyces. lactis (8.57%) and Kluyvermyces. marxianus (8.57%) were the predominant. Also 93 different lactic acid bacteria species were identified including 64 bacilli as lactobicallus and wieselia, 8 cocci, leuconostoc, 11 coccobacili, leuconostoc, lactococcus and wieselia, 2 streptococci, streptoccus and 8 tetrad cocci shapes, pediococci. All isolates fermented galactose, except Lactobacillus delbrueckii subsp. Bulgaricus, Lactobacillus kefir, Lactobacillus viridescens. All the isolates could growth at 37°C, only Leuconostoc mesenteroides subsp. Cremoris and Leuconostoc paramesenteroides could not growth at 30°C. This study revealed Chal contained a wide variety of yeasts and lactic acid bacteria.

Enhancement of the Tyrosinase Inhibitory Activity of Mori Cortex Radicis Extract by Biotransformation UsingLeuconostoc paramesenteroidesPR

Mori Cortex Radicis (MCR), the root bark of Morus alba L., consists of various phytochemicals and exhibits a strong inhibitory effect on tyrosinase. To enhance the tyrosinase inhibitory activity of MCR extract without further purification of bioactive compounds, whole MCR extract was biotransformed with crude enzyme extract from a selected lactic acid bacterium, Leuconostoc paramesenteroides PR (LP). Mulberroside A (MA), a major stilbene glucoside of MCR, contains two β-glucosyl residues at the C3 and C4' positions of oxyresveratrol (OXY). The crude enzyme of LP hydrolyzed the two glycosidic bonds of MA effectively, and 97.1% of MA was biotransformed into OXY within 2 h. Commercial almond β-glucosidase hydrolyzed only one site of the two glycosidic bonds of MA, and 68.7% of MA was biotransformed to OXY-glucoside. The tyrosinase inhibitory activity of the crude extract of MCR was increased approximately 6.5-fold by biotransformation using LP, and the IC(50) value of the transformed MCR was 3.7 µg/mL.

Production and properties of dextransucrase by free and immobilized cells of Leuconostoc paramesenteroides

Six bacterial strains were tested for the production of dextransucrase. The highest dextransucrase activities were produced by local strain Leuconostoc paramesenteroides after 24 h in static culture conditions. Dextransucrase was induced using sucrose (10 g%) as a carbon source and corn steep liquor (3.5 ml%) as a nitrogen source. Fe 2+ favoured enzyme production. Cells of L. paramesenteroides were immobilized using three supports, calcium alginate, agar and κ-carrageenan. Calcium alginate beads were able to produce dextransucrase for four runs with 100% activity. The optimum temperature for enzyme reaction ranged from 30 to 65πC at pH 5.4. In the absence of substrate, the enzyme retained 100% activity for 30 min at 40πC and 69% activity for 10 min at 60πC.

Whole cell biotransformation of major ginsenosides using Leuconostocs and Lactobacilli

Various strains of Lactobacillus and Leuconostoc species were evaluated to select the most promising strain to carry out transforming major ginsenosides into minor ginsenosides. Among the experimental lactic acid bacteria (LAB), Leuconostoc mesenteroides KFRI 690, Leuconostoc paramesenteroides KFRI 159, and Lactobacillus delbrueckii KCCM 35486 produced compound K from major ginsenosides precursors (Rb1, Rc, Rd, and F2). KFRI 690 showed the best transforming activity among them. Furthermore, these LABs could biotransform ginsenosides without disrupting the cell to release enzyme activity. The conversion ratio of Rb1 to compound K using KFRI 690 has been enhanced up to 97.8% by adding 2% sucrose into the culture medium. This is the first report on the production of compound K using whole cells of Leu. mesenteroides, Leu. paramesenteroides, and Lb. delbrueckii, which are food grade lactic acid bacteria.

A Potent Probiotic Strain from Cheddar Cheese

A lactic acid bacteria Leuconostoc paramesenteroides was isolated and characterized from cheddar cheese and was adapted to grow at low pH (2.0) and high bile salt concentration (2%) by sequential sub-culturing so that it can survive the extreme environmental condition of gut. Cell hydrophobicity assay shows the maximum adherence of the culture to toluene (46.11%). Adhesion ability was confirmed by in vitro assay using rat intestinal epithelial layer. The culture has an antimicrobial activity against food borne pathogens and is vancomycin sensitive. The culture shows a β-galactosidase activity of 3.42μM/mg protein, which indicates the ability of the culture to hydrolyze lactose for easy absorption. All these properties determine the ability of the culture to be used as a probiotic.

Characterization of lactic acid bacteria from musts and wines of three consecutive vintages of Ribeira Sacra

This study was designed to isolate and characterize the lactic acid microbiota of the musts and wines of a young denomination of origin area, Ribeira Sacra in north-west Spain. Over three consecutive years (2007, 2008 and 2009), we examined musts and wines from four cellars in different zones of the region. Through biochemical and genetic tests, 459 isolates of lactic acid bacteria (LAB) were identified as the following species: Lactobacillus alvei (0·7%), Lactobacillus brevis (1·7%), Lactobacillus frumenti (0·9%), Lactobacillus kunkeei (12%), Lactobacillus plantarum (6·5%), Lactobacillus pentosus (0·9%), Lactococcus lactis ssp. lactis (3%), Leuconostoc citreum (0·7%), Leuconostoc fructosum (synon. Lactobacillus fructosum) (3·7%), Leuconostoc mesenteroides ssp. mesenteroides (2·8%), Leuconostoc pseudomesenteroides (0·2%), Oenococcus oeni (59%), Pediococcus parvulus (7%) and Weisella paramesenteroides (synon. Leuconostoc paramesenteroides) (0·9%). Of these species, O. oeni was the main one responsible for malolactic fermentation (MLF) in all cellars and years with the exception of Lact. plantarum, predominant in 2007, in one cellar, and Lact. brevis, Lact. frumenti and Ped. parvulus coexisting with O. oeni in one cellar in 2009. Different strains (84) of LAB species (14) were identified by biochemical techniques (API strips, the presence of plasmids, enzyme activities and MLF performance) and molecular techniques (PCR). All assays were carried out with every one of the 459 isolates. To select candidates for use as culture starters, we assessed malolactic, β-glucosidase and tannase activities, the presence of genes involved in biogenic amine production and plasmid content. A high diversity of LAB is present in the grape musts of Ribeira Sacra but few species are responsible for MLF; however, different strains of such species are involved in the process. As far as we are aware, this is the first report of Lact. frumenti thriving in wine. Information on LAB populations in must and wine is presented. A large collection of well-characterized strains of LAB are available as starter cultures to winemakers.

Cytotoxicity of Dioscin and Biotransformed Fenugreek

Trigonella foenum-graecum, commonly known as fenugreek, is widely used as a spice in India, Pakistan, and China for centuries. It has been suggested that biotransformation of the glycosides by various microorganisms increase the biological activity and bioavailability. This study aims to characterize the biotransformation of the fenugreek saponins by food microorganisms and to assess the cytotoxicity of the biotransformed fenugreek extract and dioscin which is a compound produced during biotransformation against various cell lines. The production of dioscin was confirmed by TLC and LC-MS analysis. The cytotoxicities against HT-29 colon cell line were increased after biotransformation by Aspergillus usamii, Bifidobacterium infantis, Bifidobacterium sp. Int57, and Leuconostoc paramesenteroides but decreased by Aspergillus niger. The IC50 values of dioscin against five different tumor cell line cells ranged 0.72-3.22 and 2.88-8.53 μM in 2% and 10%(v/v) FBS containing media, respectively. Real time cell analysis showed that HT-29 cells died immediately after treatment with dioscin above 7.5 μM. Dioscin at 5 μM increased sub G1 phase cells when assessed with flow cytometric analysis. Since caspase-3 activity was increased by dioscin, cytotoxicity of dioscin might be related to apoptosis. Taken together, the structure and the level of saponin components in fenugreek were differentially affected by various food microorganisms. The safety and the cytotoxicity of dioscin produced during biotransformation need to be further evaluated in vivo.

시판 김치 분리 젖산균에 의한 아질산염 소거

This study confirmed depletion efficiency of nitrite when incubate lactic acid bacteria was isolated from commercial Chinese cabbage pickles (Baechu kimchi), pickled ponytail radishes (Chongkak kimchi), radish cube kimchi (Kaktugi) and pickled Wakegi (Pa kimchi) at temperatures of 15 o C and 25 o C. At 15 o C, lactic acid bacteria isolated from commercial kimchi depleted nitrite actively except Leuconostoc mesenteroides subsp. mesenteroides and Leuconostoc paramesenteroides. In particular, Leuconostoc mesenteroides subsp. dextrinicum and Leuconostoc lactis depleted nitrite by very actively without period adaptation in nitrite. Lactobacillus sake, Lactobacillus plantarum, Lactobacillus casei subsp. pseudoplantarum, and Lactobacillus coryniformis subsp. torquens depleted nitrite very actively after 1 day. L. mesenteroides subsp. mesenteroides depleted nitrite relatively actively after 2 days pass. In contrast, L. paramesenteroides displayed very low nitrite depletion ratio compared to other species. At 25 o C, all lactic acid bacteria isolated from commercial kimchi did not need adapting period in nitrite, and depleted nitrite very actively except L. paramesenteroides. Also, all lactic acid bacteria except L. mesenteroides subsp. mesenteroides and L. paramesenteroides nitrite of more than 90% after 1 day, and L. mesenteroides subsp. mesenteroides depleted nitrite of more than 90% after 2 days. However, because L. paramesenteroides was not active even at 25 o

시판김치로부터 젖산균의 분리 및 동정

본 연구에서는 시판 김치로부터 분리된 젖산균을 동정하였다. 제조 후 4일 동안 실온에서 배양된 배추김치에서 12주, 2일 동안 실온에서 배양한 총각김치에서 6주, 5일 동안 실온에서 배양한 깍두기에서 15주, 그리고 4일 동안 배양한 파김치에서 23주의 젖산균이 분리되었다. 배추김치에서 분리된 12주의 젖산균 중 8주는 Lactobacillus plantarum로, 1주는 Leuconostoc lactis로, 2주는 Lactobacillus casei subsp. pseudoplantarum으로, 그리고 1주는 Lactobacillus sake로 동정되었다. 총각김치에서 분리된 6주의 젖산균 중 3주는 Leuconostoc paramesenteroides로, 2주는 Leuconostoc mesenteroides subsp. mesenteroides로, 그리고 1주는 Lactobacillus plantarum로 동정되었다. 깍두기에서 분리된 15주 중 2주는 Leuconostoc lactis로, 3주는 Leuconostoc mesenteroides subsp. dextricum로, 4주는 Lactobacillus casei subsp. pseudoplantarum로, 그리고 4주는 Lactobacillus coryniformis subsp. torquens로 동정되었다. 파김치에서 분리된 23주 중 22주는 L. plantarum으로 그리고 1주는 Lactobacillus sake로 동정되었다. 이상의 결과로부터, 배추김치에서는 L. plantarum이, 총각김치에서는 L. paramesenteroides이, 깍두기에서는 L. casei subsp. pseudoplantarum과 L. coryniformis subsp. torquens이, 그리고 파김치에서는 L. plantarum이 가장 많이 동정되었다. 특히 파김치에서는 선발된 23주 중 1주를 제외하고는 모두 L. plantarum으로 동정되었다.

Indonesia

Lactic acid bacteria are used in the production and preservation of various fermented foods such sauerkraut (asinan sawi). Beside that, lactic acid bacteria have an important role in the inhibition of pathogenic bacteria and spoilage bacteria. Lactic acid bacteria produce several antimicrobial substance including organic acids, carbon dioxide, hydrogen peroxide, diacetyl and bacteriocins which are responsible for antagonistic activities. The aim of the research was to evaluate the antimicrobial activities of lactic acid bacteria isolated from asinan sawi on the growth of Staphylococcus aureus ATCC 25923 and Escherichia coli which have been isolated from faces of diarrhea illness patient. Eight isolates lactic acid bacteria that were isolated from sauerkraut (asinan sawi): Lactobacillus AS1, Lactobacillus AS2, Lactobacillus AS3, Lactobacillus AS4, Lactobacillus AS5, Lactobacillus AS6, Lactobacillus AS7, Leuconostoc paramesenteroides were screened for their ability to inhibit the growth of S. aureus ATCC 25923 and E. coli which have been isolated from faces of diarrhea illness patient. Antimicrobial activity of lactic acid bacteria were determined by well-agar diffusion method. All cultures lactic acid bacteria had an ability to inhibit the growth of pathogen bacteria that was used in this research. The highest antimicrobial activity showed by Lactobacillus AS6 indicated by the widest of inhibition zone was 5.16 mm of E. coli and 5.50 mm of S. aureus. This research noted that all supernatant neutral of lactic acid bacteria isolate were made sub inhibitory activity both to pathogenic bacteria.

Transformation of Ginsenosides Rb1 and Re from Panax ginseng by Food Microorganisms

Ginsenosides Rb1 and Re, respectively belonging to the major protopanaxadiol and protopanaxatriol ginsenosides, were transformed using cell-free extracts from food microorganisms. Rb1 was transformed into compound K via Rd and F2 by Bifidobacterium sp. Int57, Bif. sp. SJ32, Aspergillus niger and A. usamii. Lactobacillus delbrueckii, and Leuconostoc paramesenteroides transformed Rb1 into Rh2 via Rd and F2. Bifidobacterium sp. SH5 transformed Rb1 into F2 via Rd. Re was transformed into Rh1 via Rg2 by Bif. sp. Int57 and Bif. sp. SJ32. A. niger transformed Re into Rh1 via Rg1. A. usamii transformed Re into Rg2. Transformation of Rb1 proceeded at a higher rate and needed less amount of enzymes than that of Re. Taken together, these processes would allow a specific bioconversion process possible to obtain specific ginsenosides using an appropriate combination of ginsenoside substrates and specific microbial enzymes.

The use of starter cultures in the fermentation of boza, a traditional Turkish beverage

Batches of boza were produced from maize, rice and wheat flours using Leuconostoc paramesenteroides, L. mesenteroides subsp. mesenteroides, L. mesenteroides subsp. dextranicum, L. oenos, Lactobacillus coryniformis, L. confusus, L. sanfrancisco, L. fermentum, Saccharomyces cerevisiae and S. uvarum previously isolated from boza as starter cultures. These lactic acid bacteria (LAB) and yeasts were inoculated separately or mixed into boza wort and fermented at 30 °C. During the fermentation period, pH, acidity, LAB and yeast numbers were determined. At the end of the fermentation, sensory evaluations were carried out in order to choose the best culture combination. S. cerevisiae plus L. mesenteroides subsp. mesenteroides plus L. confusus was selected as the appropriate starter culture combination for boza production. The gross composition and rheological properties of the boza produced using this superior culture combination were determined. The paper highlights the potential for the improvement of a traditional Turkish beverage (boza) through the use of a starter culture.

Selection of starters for a traditional Turkish yayik butter made from yoghurt

Butter is produced from two different materials in Turkey, cream and yoghurt. The butter produced from fresh yoghurt or ‘tulum yoghurt’ (a strained yoghurt produced from cow, goat or sheep milk) is called ‘yayik butter’ and has been traditionally produced in Turkey for centuries. In this research, we attempted to isolate and identify the natural lactic acid bacteria (LAB) of yayik butter and to select the best LAB combination for butter production. Twenty samples of yayik butter were collected from Afyon, Antalya, Isparta and Konya regions in Turkey and determined to have a mean pH of 4·78±0·33, a mean titratable acidity (lactic acid) of 0·23±0·07% and a mean NaCl of 0·55±1·22%. The mean counts of LAB (log 10 cfu g −1) were 2·66±0·84 and 1·72±0·82 on MRS agar at 30 and 42°C, 2·44±0·93 and 1·78±0·24 on M17 agar at 30 and 42°C, and 1·64±1·196 on Sodium Azide Leuconostoc agar at 21°C, respectively. Eighty-five different LAB isolates were obtained from 20 yayik butters and identified as Streptococcus salivarius ssp. thermophilus (21·2%), Streptococcus sp. (4·7%), Lactobacillus delbrueckii ssp. bulgaricus (20%), Lactobacillus casei ssp. casei (15·3%), Lactobacillus paracasei ssp. paracasei (2·3%), Enterococcus faecium (18·8%). Leuconostoc pseudomesenteroides ( Leucono-stoc mesenteroides ssp. dextranicum) (7·1%), Leuconostoc gelidum ( Leuconostoc mesenteroides ssp. mesenteroides ) (4·7%) and Weissella paramesenteroides ( Leuconostoc paramesenteroides) (5·9%). Combinations of S. salivarius ssp. thermophilus S51, Lb. delbrueckii ssp. bulgaricus A42, Lb. casei ssp. casei K64, Lb. paracasei ssp. paracasei A27, and Leu. pseudomesenteroides E83 were used as starter bacteria for experimental butter production from cream. Six different groups of butters were produced using different combinations of these bacteria (B, C, D and E samples), commercial culture (F sample), and without culture (A sample). Sensory evaluations showed that the experimentally produced butter sample of group B was more acceptable than the other butters. In addition, the buttermilk of sample B had lowest fact content. LAB counts of experimental butters produced with combined cultures and commercial culture were similar (6·66±1·87–6·83±0·040 and 6·81±0·13 log 10 cfu g −1 on MRS agar, respectively).

ISOLATION AND CHARACTERIZATION OF BACTERIOCIN-PRODUCING MICROORGANISMS FROM AGOS-OS

Agos-os, a fermented meat and sweetpotato mixture, was produced and analyzed for its microbial characteristics. pH decreased during fermentation. Mold and anaerobic bacterial counts increased while yeasts and aerobic bacterial counts decreased during the third and seventh day of fermentation. Six isolates with the widest zones of inhibition on the indicator lawn were selected for bacteriocin production. These isolates had exactly the same morphological, physiological and biochemical characteristics. The ribosomal RNA sequence was 99.5% identical with Enterococcus faecalis VRE 1492. The identification was confirmed through DNA homology test by the EMBL Genbank, Canada. This bacterium produced the L-isomer lactic acid. The amount of bacteriocin produced by the bacterium was optimized by growing the bacterium at different growth media, initial pH and fermentation time. Maximum production of bacteriocin was achieved in MRS (De Man Rugosa and Sharpe) medium (with glucose) at pH 7.50. The crude bacteriocin inhibited the growth of gram-positive bacteria such as Lactobacillus sake 15521 and Listeria innocua. The gram-negative bacteria such as Escherichia coli DH 5-alpha (with plasmid, PUC), Salmonella typhii and Staphylococcus aureus were weakly inhibited. Other microorganisms such as Lactobacillus curvatus D31685, Lactobacillus confusius M23036, Lactococcus lactis MG1363, Leuconostoc paramesenteroides S67831, Pediococcus pentosaceus M58834, Saccharomyces cerevisiae SS553 (wild type) and Escherichia coli JM109 (no plasmid) were not inhibited.