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Guohong Wang Sheng Yin Haoran An Shangwu Chen Yanling Hao 《Journal of industrial microbiology & biotechnology》2011,38(8):985-990
Lactic acid bacteria (LAB) encounter various types of stress during industrial processes and gastrointestinal transit. Catalase
(CAT) and bile salt hydrolase (BSH) can protect bacteria from oxidative stress or damage caused by bile salts by decomposing
hydrogen peroxide (H2O2) or deconjugating the bile salts, respectively. Lactobacillus
casei is a valuable probiotic strain and is often deficient in both CAT and BSH. In order to improve the resistance of L. casei to both oxidative and bile salts stress, the catalase gene katA from L. sakei and the bile salt hydrolase gene bsh1 from L. plantarum were coexpressed in L. casei HX01. The enzyme activities of CAT and BSH were 2.41 μmol H2O2/min/108 colony-forming units (CFU) and 2.11 μmol glycine/min/ml in the recombinant L. casei CB, respectively. After incubation with 8 mM H2O2, survival ratio of L. casei CB was 40-fold higher than that of L. casei CK. Treatment of L. casei CB with various concentrations of sodium glycodeoxycholate (GDCA) showed that ~105 CFU/ml cells survived after incubation with 0.5% GDCA, whereas almost all the L. casei CK cells were killed when treaded with 0.4% GDCA. These results indicate that the coexpression of CAT and BSH confers high-level
resistance to both oxidative and bile salts stress conditions in L. casei HX01. 相似文献
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Elina Mäkimattila Minna Kahala Vesa Joutsjoki 《World journal of microbiology & biotechnology》2011,27(2):371-379
Aims of the study were to characterize two Lactobacillus plantarum-related strains, Lact.
plantarum and Lactobacillus paraplantarum isolated from fermented vegetables and, for their potential use as starter strains, compare their growth in various food
matrices. Species-level identification of the strains belonging to the Lact. plantarum group was performed by multiplex-PCR with species-specific primers and generation of distinct genotypic profiles was carried
out by PFGE-based DNA-fingerprinting. Growth profiles were determined in various food and feed matrices. Compared to Lact. plantarum,
Lact. paraplantarum reached higher cell densities in all plant-based matrices and MRS broth. On the contrary to the good growth in plant-based
matrices and MRS, poor growth was observed in unprocessed milk. Supplemented lactose did not improve the growth of either
tested strain, while predigestion of milk proteins with Lactobacillus helveticus or addition of casitone proved to be an effective means to enhance growth. To find out the applicability of molecular methods,
the strains were transformed with replicative plasmids by electroporation. To our knowledge, this is a first report of the
electrotransformation of Lact. paraplantarum with a recombinant plasmid. 相似文献
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A gene coding for bile salt hydrolase (BSH) from Bifidobacterium adolescentis was cloned and expressed in Escherichia coli, and the nucleotide sequence was determined. The BSH of E. coli transformants was produced intracellularly in the absence of bile salts. A unique bsh promoter (Pbsh) sequence was identified by using a Neural Network Promoter Prediction (NNPP, version 2.2). In spite of their high-level sequence homology with other bsh genes in the Bifidobacterium species, their genetic organization surrounding the bsh gene and their promoter sequences are different depending on the species. 相似文献
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<Emphasis Type="Italic">Lactobacillus plantarum</Emphasis> and Its Probiotic and Food Potentialities
Hamza Ait Seddik Farida Bendali Frédérique Gancel Ismail Fliss Giuseppe Spano Djamel Drider 《Probiotics and antimicrobial proteins》2017,9(2):111-122
The number of studies claiming probiotic health effects of Lactobacillus plantarum is escalating. Lb. plantarum is a lactic acid bacterium found in diverse ecological niches, highlighting its particular capabilities of adaptation and genome plasticity. Another function that needs to be underlined is the capabilities of Lb. plantarum to produce diverse and potent bacteriocins, which are antimicrobial peptides with possible applications as food preservative or antibiotic complementary agents. Taken together, all these characteristics design Lb. plantarum as a genuine model for academic research and viable biological agent with promising applications. The present review aims at shedding light on the safety of Lb. plantarum and run through the main studies underpinning its beneficial claims. The mechanisms explaining probiotic-related features are discussed. 相似文献
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Erwann Hamon Peter Horvatovich Esther Izquierdo Françoise Bringel Eric Marchioni Dalal Aoudé-Werner Saïd Ennahar 《BMC microbiology》2011,11(1):63
Background
Lactic acid bacteria are commonly marketed as probiotics based on their putative or proven health-promoting effects. These effects are known to be strain specific but the underlying molecular mechanisms remain poorly understood. Therefore, unravelling the determinants behind probiotic features is of particular interest since it would help select strains that stand the best chance of success in clinical trials. Bile tolerance is one of the most crucial properties as it determines the ability of bacteria to survive in the small intestine, and consequently their capacity to play their functional role as probiotics. In this context, the objective of this study was to investigate the natural protein diversity within the Lactobacillus plantarum species with relation to bile tolerance, using comparative proteomics. 相似文献7.
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V. C. Dilukshi Fernando Wesam Al Khateeb Mark F. Belmonte Dana F. Schroeder 《Plant molecular biology》2018,97(1-2):149-163
Key message
Arabidopsis det1 mutants exhibit salt and osmotic stress resistant germination. This phenotype requires HY5, ABF1, ABF3, and ABF4.Abstract
While DE-ETIOLATED 1 (DET1) is well known as a negative regulator of light development, here we describe how det1 mutants also exhibit altered responses to salt and osmotic stress, specifically salt and mannitol resistant germination. LONG HYPOCOTYL 5 (HY5) positively regulates both light and abscisic acid (ABA) signalling. We found that hy5 suppressed the det1 salt and mannitol resistant germination phenotype, thus, det1 stress resistant germination requires HY5. We then queried publically available microarray datasets to identify genes downstream of HY5 that were differentially expressed in det1 mutants. Our analysis revealed that ABA regulated genes, including ABA RESPONSIVE ELEMENT BINDING FACTOR 3 (ABF3), are downregulated in det1 seedlings. We found that ABF3 is induced by salt in wildtype seeds, while homologues ABF4 and ABF1 are repressed, and all three genes are underexpressed in det1 seeds. We then investigated the role of ABF3, ABF4, and ABF1 in det1 phenotypes. Double mutant analysis showed that abf3, abf4, and abf1 all suppress the det1 salt/osmotic stress resistant germination phenotype. In addition, abf1 suppressed det1 rapid water loss and open stomata phenotypes. Thus interactions between ABF genes contribute to det1 salt/osmotic stress response phenotypes.9.
Liu JR Duan CH Zhao X Tzen JT Cheng KJ Pai CK 《Applied microbiology and biotechnology》2008,81(2):225-233
A gene encoding a xylanase, named xynS20, was cloned from the ruminal fungus Neocallimastix patriciarum. The DNA sequence of xynS20 revealed that the gene was 1,008 bp in size and encoded amino acid sequences with a predicted molecular weight of 36 kDa.
The amino acid sequence alignment showed that the highest sequence identity (28.4%) is with insect gut xylanase XYL6805. According
to the sequence-based classification, a putative conserved domain of glycosyl hydrolase family 11 was detected at the N-terminus
of XynS20 and a putative conserved domain of family 1 carbohydrate-binding module (CBM) was observed at the C-terminus of
XynS20. An Asn-rich linker sequence was found between the N-terminal catalytic domain and the C-terminal CBM of XynS20. To
examine the activity of the gene product, xynS20 gene was cloned as an oleosin-fused protein, expressed in Escherichia coli, affinity-purified by formation of artificial oil bodies, released from oleosin by intein-mediated peptide cleavage, and
finally harvested by concentration of the supernatant. The specific activity of purified XynS20 toward oat spelt xylan was
1,982.8 U mg−1. The recombinant XynS20 was stable in the mild acid pH range from 5.0 to 6.0, and the optimum pH was 6.0. The optimal reaction
temperature of XynS20 was 45°C; at temperatures below 30 and above 55°C, enzyme activity was less than 50% of that at the
optimal temperature. 相似文献
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l-arabinose isomerase (EC5.3.1.4. AI) mediates the isomerization of d-galactose into d-tagatose as well as the conversion of l-arabinose into l-ribulose. The AI from Lactobacillus plantarum SK-2 was purified to an apparent homogeneity giving a single band on SDS–PAGE with a molecular mass of 59.6 kDa. Optimum
activity was observed at 50°C and pH 7.0. The enzyme was stable at 50°C for 2 h and held between pH 4.5 and 8.5 for 1 h. AI
activity was stimulated by Mn2+, Fe3+, Fe2+, Ca2+ and inhibited by Cu2+, Ag+, Hg2+, Pb2+. d-galactose and l-arabinose as substrates were isomerized with high activity. l-arabitol was the strongest competitive inhibitor of AI. The apparent Michaelis–Menten constant (K
m), for galactose, was 119 mM. The first ten N-terminal amino acids of the enzyme were determined as MLSVPDYEFW, which is identical to L. plantarum (Q88S84). Using the purified AI, 390 mg tagatose could be converted from 1,000 mg galactose in 96 h, and this production
corresponds to a 39% equilibrium. 相似文献
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Production of gamma-aminobutyric acid (GABA) from crop biomass such as cassava in high concentration is desirable, but difficult to achieve. A safe biotechnological route was investigated to produce GABA from cassava powder by C. glutamicum G01 and L. plantarum GB01-21. Liquefied cassava powder was first transformed to glutamic acid by simultaneous saccharification and fermentation with C. glutamicum G01, followed by biotransformation of glutamic acid to GABA with resting cells of L. plantarum GB01-21 in the reaction medium. After optimizing the reaction conditions, the maximum concentration of GABA reached 80.5 g/L with a GABA productivity of 2.68 g/L/h. This is the highest yield ever reported of GABA production from cassava-derived glucose. The bioprocess provides the added advantage of employing nonpathogenic microorganisms, C. glutamicum and L. plantarum, in microbial production of GABA from cassava biomass, which can be used in the food and pharmaceutical industries. 相似文献
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In order to monitor Lactobacillus plantarum and Oenococcus oeni in red wine produced with Italian grape (variety “Primitivo di Puglia”), a polymerase chain reaction– denaturing gradient
gel electrophoresis (PCR-DGGE) approach using the rpoB as gene target was established. Wine was treated or not with potassium metabisulphite and supplemented with a commercial
bacterial starter of O. oeni to encourage malolactic fermentation. Samples were taken from the vinification tanks at 4, 10, 16, 22, and 28 days after
the start of alcoholic fermentation. Genomic DNA was directly isolated from wine and identification of lactic acid bacteria
was performed using primers rpoB1, rpoB1O, and rpoB2 able to amplify a region of 336 bp corresponding to the rpoB gene. Amplified fragments were separated in a 30–60% DGGE gradient, and the ability of the PCR-DGGE analysis to distinguish
L. plantarum and O. oeni was assessed. The results reported suggest that the PCR-DGGE method, based on the rpoB gene as molecular marker, is a reproducible and suitable tool and may be of great value for wine makers in order to monitor
spoilage microorganisms during wine fermentation. 相似文献
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Malolactic fermentation (MLF) plays an important role in the production of wine, especially red wines, resulting in microbial
stability, deacidification, as well as contributing to the aroma profile. MLF can be influenced by a number of factors. In
this study, the influence of pH and ethanol on expression of the structural malolactic enzyme gene (mle) from Lactobacillus plantarum was investigated in a synthetic wine media, as well as in wine using quantitative PCR. Expression of mle was shown to be inducible by the presence of malic acid, with increased expression in the middle of MLF. Expression of mle was also shown to be increased at low pH values and decreased in the presence of ethanol. This indicates the role of MLF
in acid tolerance and the negative impact of ethanol on the completion of MLF. The results therefore provide further evidence
that L. plantarum should be applied as co-inoculation for MLF where alcohol will initially not have a negative impact on the malic acid degradation. 相似文献
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This study describes two phenotypes of Arabidopsis thaliana (ecotype Columbia) developed in vitro under salt stress (75 mM NaCl). The phenotypes 01 and 02 appeared visibly distinguishable by rosette morphology and competence
to produce flowers. Phenotype 01, sensible to salt stress, accumulated high quantities of Na+, showed a slight reduction in dry mass, and high protein and chlorophyll contents. Moreover, its anatomy exhibited some xeromorphic
traits. Phenotype 02, clearly salt tolerant, showed a morphology similar to control plants, displaying typical phyllotactic
rosette and flowering stalk production. Accumulation of Na+, protein and chlorophyll contents were close to control plants. Reversion experiments on NaCl free MS medium, showed a partially
recovered phenotype 01. A threshold salt stress concentration that permits the simultaneous development of two phenotypes,
was found. 相似文献
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Arno Wegkamp Astrid E Mars Magda Faijes Douwe Molenaar Ric CH de Vos Sebastian MJ Klaus Andrew D Hanson Willem M de Vos Eddy J Smid 《Microbial cell factories》2010,9(1):100
Background
Using a functional genomics approach we addressed the impact of folate overproduction on metabolite formation and gene expression in Lactobacillus plantarum WCFS1. We focused specifically on the mechanism that reduces growth rates in folate-overproducing cells. 相似文献17.
Svetoslav Dimitrov Todorov Luana M. Perin Bruno M. Carneiro Paula Rahal Wilhelm Holzapfel Luís Augusto Nero 《Probiotics and antimicrobial proteins》2017,9(3):334-344
Total DNA extracted from Lb. plantarum ST8Sh was screened for the presence of more than 50 genes related to production of biogenic amines (histidine decarboxylase, tyrosine decarboxylase, and ornithine decarboxylase), virulence factors (sex pheromones, gelatinase, cytolysin, hyaluronidase, aggregation substance, enterococcal surface protein, endocarditis antigen, adhesion of collagen, integration factors), and antibiotic resistance (vancomycin, tetracycline, erythromycin, gentamicin, chloramphenicol, bacitracin). Lb. plantarum ST8Sh showed a low presence of virulence genes. Only 13 genes were detected (related to sex pheromones, aggregation substance, adhesion of collagen, tetracycline, gentamicin, chloramphenicol, erythromycin, but not to vancomycin, and bacitracin) and may be considered as indication of safety for application in fermented food products. In addition, interaction between Lb. plantarum ST8Sh and drugs from different groups were determined in order to establish possible application of the strain in combination with commercial drugs. Cytotoxicity of the semi-purified bacteriocins produced by Lb. plantarum ST8Sh was depended on applied concentration—highly cytotoxic when applied at 25 μg/mL and no cytotoxicity at 5 μg/mL. 相似文献
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Lactic acid bacteria (LABs) are being used as a probiotic very often for various enteric problems. Many genetically modified
LABs are created by different workers for various novel applications. In this study we examine the expression of heterologous
oxalate decarboxylase (oxdc) in Lactobacillus plantarum NC8. Generally, this enzyme is not present in Lactobacillus spp. Oxdc gene from Bacillus subtilis was polymerase chain reaction-amplified and cloned in a shuttle vector pSIP400 series, downstream of the inducible promoter,
Porfx. In the presence of an inducing peptide, Sakacin-P, the expression of OxdC was observed in sodium dodecyl sulfate–polyacrylamide
gel electrophoresis. The cell-free extract and the purified protein from the recombinant LABs showed the presence of OxdC
activity. The above recombinant LABs, with desired modifications, can be used as a possible probiotic for the degradation
of intestinal dietary oxalate for preventing enteric hyperoxaluria. 相似文献
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