Complementation of the Lactococcus lactis Secretion Machinery with Bacillus subtilis SecDF Improves Secretion of Staphylococcal Nuclease

ABSTRACT Unlike Bacillus subtilis and Escherichia coli, the gram-positive lactic acid bacterium Lactococcus lactis does not possess the SecDF protein, a component of the secretion (Sec) machinery involved in late secretion stages and required for the high-capacity protein secretion in B. subtilis. In this study, we complemented the L. lactis Sec machinery with SecDF from B. subtilis and evaluated the effect on the secretion of two forms of staphylococcal nuclease, NucB and NucT, which are efficiently and poorly secreted, respectively. The B. subtilis SecDF-encoding gene was tested in L. lactis at different levels. Increased quantities of the precursor and mature forms were observed only at low levels of SecDF and at high NucT production levels. This SecDF secretion enhancement was observed at the optimal growth temperature (30°C) and was even greater at 15°C. Furthermore, the introduction of B. subtilis SecDF into L. lactis was shown to have a positive effect on a secreted form of Brucella abortus L7/L12 antigen.

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Isolation, sequence and expression in Escherichia coli, Bacillus subtilis and Lactococcus lactis of the DNase (streptodornase)-encoding gene from Streptococcus equisimilis H46A

Gene ◽

10.1016/0378-1119(91)90574-u ◽

1991 ◽

Vol 106 (1) ◽

pp. 115-119 ◽

Cited By ~ 12

Author(s):

Renata Wolinowska ◽

Piotr Cegtowski ◽

Jan Kok ◽

Gerard Venema

Keyword(s):

Escherichia Coli ◽

Bacillus Subtilis ◽

Lactococcus Lactis ◽

Expression In Escherichia Coli ◽

Encoding Gene

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Regulation of Bacillus subtilis aprE Expression by glnA through Inhibition of scoC and σD-Dependent degR Expression

Journal of Bacteriology ◽

10.1128/jb.00049-09 ◽

2009 ◽

Vol 191 (9) ◽

pp. 3050-3058 ◽

Cited By ~ 12

Author(s):

Sadanobu Abe ◽

Ayako Yasumura ◽

Teruo Tanaka

Keyword(s):

Bacillus Subtilis ◽

Glutamine Synthetase ◽

Alkaline Protease ◽

Negative Regulator ◽

Negative Regulators ◽

Global Regulation ◽

Positive Regulation ◽

Expression Levels ◽

Negative Effect ◽

Positive Effect

ABSTRACT Expression of the gene for the extracellular alkaline protease (aprE) of Bacillus subtilis is subject to regulation by many positive and negative regulators. We have found that aprE expression was increased by disruption of the glutamine synthetase gene glnA. The increase in aprE expression was attributed to a decreased in expression of scoC, which encodes a negative regulator of aprE expression. The glnA effect on scoC expression was abolished by further disruption of tnrA, indicating that aprE expression is under global regulation through TnrA. In the scoC background, however, aprE expression was decreased by glnA deletion, and it was shown that the decrease was due to a defect in positive regulation by DegU. Among the genes that affect aprE expression through DegU, the expression of degR, encoding a protein that stabilizes phosphorylated DegU, was inhibited by glnA deletion. It was further shown that the decrease in degR expression by glnA deletion was caused by inhibition of the expression of sigD, encoding the σD factor, which is required for degR expression. In accordance with these findings, the expression levels of aprE-lacZ in glnA scoC degR and scoC degR strains were identical. These results led us to conclude that glnA deletion brings about two effects on aprE expression, i.e., a positive effect through inhibition of scoC expression and a negative effect through inhibition of degR expression, with the former predominating over the latter.

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Wheat Bread with Grape Seeds Micropowder: Impact on Dough Rheology and Bread Properties

Applied Rheology ◽

10.1515/arh-2020-0112 ◽

2020 ◽

Vol 30 (1) ◽

pp. 138-150

Author(s):

Veronika Valková ◽

Hana Ďúranová ◽

Jana Štefániková ◽

Michal Miškeje ◽

Marián Tokár ◽

...

Keyword(s):

Wheat Flour ◽

Dough Rheology ◽

Wheat Bread ◽

Grape Seeds ◽

Rheological Analysis ◽

First Time ◽

Positive Effect ◽

Bread Properties ◽

Electronic Eye ◽

Different Levels

AbstractThe current study was designed to enhance the functionality of white bread by replacement of wheat flour with different levels (1%, 2%, 5%, and 8%) of grape seeds micropowder (GSMP) with nanosized particles (10 µm). Chemical composition of GSMP, volume and sensory attributes, evaluated with the panel of evaluators and an electronic nose (e-nose) and an electronic eye (e-eye) were investigated in the tested breads. It has been found out that GSMP contained appreciable amounts of flavonoids including catechin, epicatechin, gallic acid and minerals especially, Ca, K and Mg. The data from rheological analysis showed that the addition of GSMP (mainly at 5% and 8% levels) to the wheat flour had a positive effect on dough manifesting with rheology by increased dough stability. The volume of the experimental breads (above 1% concentration) was demonstrably declined (P < 0.0001) in comparison with the control bread. Sensory rating revealed that the bread fortified with 1% GSMP was judged by the consumer panelists as the most acceptable with the highest scores for all quality attributes which was also confirmed by the data of e-nose and e-eye. Our results suggest for the first time that 1% GSMP addition appears to be a promising functional ingredient to improve bread with required qualitative and sensory properties.

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Velody 2—Resilient High-Capacity MIDI Steganography for Organ and Harpsichord Music

Applied Sciences ◽

10.3390/app11010039 ◽

2020 ◽

Vol 11 (1) ◽

pp. 39

Author(s):

Eric Järpe ◽

Mattias Weckstén

Keyword(s):

Mean Absolute Error ◽

Signal To Noise Ratio ◽

High Capacity ◽

Absolute Error ◽

Music Technology ◽

Alternative Methods ◽

File Size ◽

User Friendly ◽

Different Levels ◽

Better Than

A new method for musical steganography for the MIDI format is presented. The MIDI standard is a user-friendly music technology protocol that is frequently deployed by composers of different levels of ambition. There is to the author’s knowledge no fully implemented and rigorously specified, publicly available method for MIDI steganography. The goal of this study, however, is to investigate how a novel MIDI steganography algorithm can be implemented by manipulation of the velocity attribute subject to restrictions of capacity and security. Many of today’s MIDI steganography methods—less rigorously described in the literature—fail to be resilient to steganalysis. Traces (such as artefacts in the MIDI code which would not occur by the mere generation of MIDI music: MIDI file size inflation, radical changes in mean absolute error or peak signal-to-noise ratio of certain kinds of MIDI events or even audible effects in the stego MIDI file) that could catch the eye of a scrutinizing steganalyst are side-effects of many current methods described in the literature. This steganalysis resilience is an imperative property of the steganography method. However, by restricting the carrier MIDI files to classical organ and harpsichord pieces, the problem of velocities following the mood of the music can be avoided. The proposed method, called Velody 2, is found to be on par with or better than the cutting edge alternative methods regarding capacity and inflation while still possessing a better resilience against steganalysis. An audibility test was conducted to check that there are no signs of audible traces in the stego MIDI files.

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Mobile Money, Financial Inclusion and Digital Payment: The Case of Vietnam

International Journal of Financial Research ◽

10.5430/ijfr.v11n1p417 ◽

2019 ◽

Vol 11 (1) ◽

pp. 417

Author(s):

Tran Hung Son ◽

Nguyen Thanh Liem ◽

Nguyen Vinh Khuong

Keyword(s):

Financial Inclusion ◽

Financial Intermediaries ◽

Positive Trend ◽

African Countries ◽

Financial Intermediary ◽

Middle Income ◽

Mobile Money ◽

Low Levels ◽

Digital Transactions ◽

Positive Effect

The study provides an overview of mobile money account usage, financial inclusion and digital payment transaction trends in Vietnam, and considers the factors influencing these trends. In general, the rates of using mobile money service and account ownership at financial intermediaries in Vietnam are still low, and other indicators of digital transactions suggest low levels compared to those of countries with low- and middle- income as well as to the world averages. The research also shows that owning an account at a financial intermediary facilitates the use of mobile money. This is a positive trend, at least compared to the situation in some African countries. Finally, having an account at a financial intermediary and using mobile money services generally have a positive effect on the participation in non-cash transactions.

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Investigation of Na+ and K+ Transport in Halophytes: Functional Analysis of the HmHKT2;1 Transporter from Hordeum maritimum and Expression under Saline Conditions

Plant and Cell Physiology ◽

10.1093/pcp/pcz136 ◽

2019 ◽

Vol 60 (11) ◽

pp. 2423-2435 ◽

Cited By ~ 6

Author(s):

Dorsaf Hmidi ◽

Dorsaf Messedi ◽

Claire Corratgï¿½-Faillie ◽

Thï¿½o Marhuenda ◽

Cï¿½cile Fizames ◽

...

Keyword(s):

Absorption Efficiency ◽

Extracellular Loop ◽

Transmembrane Segment ◽

Transport Pathway ◽

Reverse Transcription Pcr ◽

Encoding Gene ◽

K Transport ◽

Different Levels ◽

Adaptation To Salinity

Abstract Control of K+ and Na+ transport plays a central role in plant adaptation to salinity. In the halophyte Hordeum maritimum, we have characterized a transporter gene, named HmHKT2;1, whose homolog HvHKT2;1 in cultivated barley, Hordeum vulgare, was known to give rise to increased salt tolerance when overexpressed. The encoded protein is strictly identical in two H. maritimum ecotypes, from two biotopes (Tunisian sebkhas) affected by different levels of salinity. These two ecotypes were found to display distinctive responses to salt stress in terms of biomass production, Na+ contents, K+ contents and K+ absorption efficiency. Electrophysiological analysis of HmHKT2;1 in Xenopus oocytes revealed distinctive properties when compared with HvHKT2;1 and other transporters from the same group, especially a much higher affinity for both Na+ and K+, and an Na+–K+ symporter behavior in a very broad range of Na+ and K+ concentrations, due to reduced K+ blockage of the transport pathway. Domain swapping experiments identified the region including the fifth transmembrane segment and the adjacent extracellular loop as playing a major role in the determination of the affinity for Na+ and the level of K+ blockage in these HKT2;1 transporters. The analysis (quantitative reverse transcription-PCR; qRT-PCR) of HmHKT2;1 expression in the two ecotypes submitted to saline conditions revealed that the levels of HmHKT2;1 transcripts were maintained constant in the most salt-tolerant ecotype whereas they decreased in the less tolerant one. Both the unique functional properties of HmHKT2;1 and the regulation of the expression of the encoding gene could contribute to H. maritimum adaptation to salinity.

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Investigation of Protein Export in Bifidobacterium breve UCC2003

Applied and Environmental Microbiology ◽

10.1128/aem.69.12.6994-7001.2003 ◽

2003 ◽

Vol 69 (12) ◽

pp. 6994-7001 ◽

Cited By ~ 32

Author(s):

Laura E. MacConaill ◽

Gerald F. Fitzgerald ◽

Douwe van Sinderen

Keyword(s):

Fusion Proteins ◽

Genomic Library ◽

Shuttle Vector ◽

Staphylococcal Nuclease ◽

Cell Fractionation ◽

Reporter System ◽

Bifidobacterium Breve ◽

Positive Effects ◽

Encoding Gene ◽

Export Signal

ABSTRACT The molecular interactions between the bifidobacterial cell and its natural environment, namely, the gastrointestinal tract of its host, are particularly important in understanding the presumed positive effects of Bifidobacterium on the health status of the host. In this study an export-specific reporter system, designed for use in gram-positive organisms and based on the use of the staphylococcal nuclease (Nuc) as a reporter, was employed to identify exported proteins in Bifidobacterium breve UCC2003. A B. breve genomic library of translational fusions to the Nuc-encoding gene devoid of its own export signal was established in the shuttle vector pFUN (I. Poquet, S. D. Ehrlich, and A. Gruss, J. Bacteriol. 180:1904-1912, 1998) and screened for bifidobacterial export signals. Sequence analysis of the fusion proteins obtained that displayed a nuclease-producing phenotype in both Lactococcus lactis and B. breve predicted the presence of a classical signal peptide and/or single or multiple transmembrane domains, thus indicating that some of the export signals in B. breve are comparable to those used in L. lactis. Cell fractionation studies, zymograms, nuclease assays, and Western blotting were employed to confirm the function of the predicted signals and to determine the location and activity of the exported fusion proteins in B. breve and/or L. lactis.

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Genetic Analysis of Factors Affecting Susceptibility of Bacillus subtilis to Daptomycin

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01329-08 ◽

2009 ◽

Vol 53 (4) ◽

pp. 1598-1609 ◽

Cited By ~ 105

Author(s):

Anna-Barbara Hachmann ◽

Esther R. Angert ◽

John D. Helmann

Keyword(s):

Bacillus Subtilis ◽

Cell Envelope ◽

Transcriptional Profiling ◽

Protein A ◽

Multidrug Resistant ◽

Dependent Manner ◽

Membrane Composition ◽

Factors Affecting ◽

Anionic Phospholipids ◽

Cyclic Lipopeptide

ABSTRACT Daptomycin is the first of a new class of cyclic lipopeptide antibiotics used against multidrug-resistant, gram-positive pathogens. The proposed mechanism of action involves disruption of the functional integrity of the bacterial membrane in a Ca2+-dependent manner. We have used transcriptional profiling to demonstrate that treatment of Bacillus subtilis with daptomycin strongly induces the lia operon including the autoregulatory LiaRS two-component system (homologous to Staphylococcus aureus VraSR). The lia operon protects against daptomycin, and deletion of liaH, encoding a phage-shock protein A (PspA)-like protein, leads to threefold increased susceptibility. Since daptomycin interacts with the membrane, we tested mutants with altered membrane composition for effects on susceptibility. Deletion mutations of mprF (lacking lysyl-phosphatidylglycerol) or des (lipid desaturase) increased daptomycin susceptibility, whereas overexpression of MprF decreased susceptibility. Conversely, depletion of the cell for the anionic lipid phosphatidylglycerol led to increased resistance. Fluorescently labeled daptomycin localized to the septa and in a helical pattern around the cell envelope and was delocalized upon the depletion of phosphatidylglycerol. Together, these results indicate that the daptomycin-Ca2+ complex interacts preferentially with regions enriched in anionic phospholipids and leads to membrane stresses that can be ameliorated by PspA family proteins.

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Functional Analysis of the Bacillus subtilis Zur Regulon

Journal of Bacteriology ◽

10.1128/jb.184.23.6508-6514.2002 ◽

2002 ◽

Vol 184 (23) ◽

pp. 6508-6514 ◽

Cited By ~ 93

Author(s):

Ahmed Gaballa ◽

Tao Wang ◽

Rick W. Ye ◽

John D. Helmann

Keyword(s):

Bacillus Subtilis ◽

Metal Ion ◽

Dna Microarrays ◽

Optimal Growth ◽

Zinc Uptake ◽

Uptake System ◽

Mobility Shift ◽

Transport Pathway ◽

Dnase I Footprinting ◽

Transporter Family

ABSTRACT The Bacillus subtilis zinc uptake repressor (Zur) regulates genes involved in zinc uptake. We have used DNA microarrays to identify genes that are derepressed in a zur mutant. In addition to members of the two previously identified Zur-regulated operons (yciC and ycdHI-yceA), we identified two other genes, yciA and yciB, as targets of Zur regulation. Electrophoretic mobility shift experiments demonstrated that all three operons are direct targets of Zur regulation. Zur binds to an ∼28-bp operator upstream of the yciA gene, as judged by DNase I footprinting, and similar operator sites are found preceding each of the previously described target operons, yciC and ycdHI-yceA. Analysis of a yciA-lacZ fusion indicates that this operon is induced under zinc starvation conditions and derepressed in the zur mutant. Phenotypic analyses suggest that the YciA, YciB, and YciC proteins may function as part of the same Zn(II) transport pathway. Mutation of yciA or yciC, singly or in combination, had little effect on growth of the wild-type strain but significantly impaired the growth of the ycdH mutant under conditions of zinc limitation. Since the YciA, YciB, and YciC proteins are not obviously related to any known transporter family, they may define a new class of metal ion uptake system. Mutant strains lacking all three identified zinc uptake systems (yciABC, ycdHI-yceA, and zosA) are dependent on micromolar levels of added zinc for optimal growth.

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