scholarly journals Improved antimicrobial spectrum of the N-acetylmuramoyl-L-alanine amidase from Latilactobacillus sakei upon LysM domain deletion

2021 ◽  
Author(s):  
Adriana López-Arvizu ◽  
Diana Rocha-Mendoza ◽  
Amelia Farrés ◽  
Edith Ponce-Alquicira ◽  
Israel García-Cano
Keyword(s):  
Leuconostoc Mesenteroides ◽  
Meat Product ◽  
Complete Sequence ◽  
Maximum Activity ◽  
Gene Encoding ◽  
Antimicrobial Spectrum ◽  
Lysm Domain ◽  
Ph Values ◽  
Inhibitory Spectrum ◽  
Molecular Masses

Abstract The gene encoding N-acetylmuramoyl-L-alanine amidase in Latilactobacillus sakei isolated from a fermented meat product was cloned in two forms: its complete sequence (AmiC) and without one of its anchoring LysM domains (AmiLysM4). Deletion of the LysM domain is believed to affect the target microorganism’s affinity to the cell wall, which influences antimicrobial activity. To compare activity and inhibitory spectra, AmiC and AmiLysM4 were expressed in Escherichia coli BL21. Using the zymography technique, two bands with lytic activity were observed, which were confirmed by LC-MS/MS analysis, with molecular masses of 71 kDa (AmiC) and 66 kDa (AmiLysM4). The recombinant proteins were active against Listeria innocua and Staphylococcus aureus strains; however, the inhibitory spectrum of AmiLysM4 was broader because AmiLysM4 could inhibit Leuconostoc mesenteroides and Weissella viridescens, which are microorganisms associated with food deterioration. Optimal temperature and pH values were determined for both proteins using L-alanine-p-nitroanilide hydrochloride as a substrate for N-acetylmuramoyl-L-alanine amidase activity. Both proteins showed similar maximum activity values for pH (8) and temperature (50°C). Furthermore, in silico predictions did not show differences for the catalytic region, but differences were found for the region called 3dom, which includes 3 of the 5 LysM domains. Therefore, the modification of the LysM domain offers new tools for the development of novel food biopreservatives.

The complete sequence of the gene encoding bovine α2-casein

Gene ◽  
1993 ◽  
Vol 123 (2) ◽  
pp. 187-193 ◽  
Author(s):  
M.A.M. Groenen ◽  
R.J.M. Dijkhof ◽  
A.J.M. Verstege ◽  
J.J. van der Poel
Keyword(s):  
Complete Sequence ◽  
Gene Encoding

Identification and functional characterization of levS, a gene encoding for a levansucrase from Leuconostoc mesenteroides NRRL B-512 F

Gene ◽  
2006 ◽  
Vol 376 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Sandra Morales-Arrieta ◽  
Maria Elena Rodríguez ◽  
Lorenzo Segovia ◽  
Agustín López-Munguía ◽  
Clarita Olvera-Carranza
Keyword(s):  
Leuconostoc Mesenteroides ◽  
Functional Characterization ◽  
Gene Encoding

GROWTH RATES AND FERMENTATION PATTERNS OF LACTIC ACID BACTERIA ASSOCIATED WITH THE SAUERKRAUT FERMENTATION1

1971 ◽  
Vol 34 (11) ◽  
pp. 521-525 ◽  
Author(s):  
J. R. Stamer ◽  
B. O. Stoyla ◽  
B. A. Dunckel
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Growth Rates ◽  
Leuconostoc Mesenteroides ◽  
Lactobacillus Brevis ◽  
Sensitive Species ◽  
Ph Values ◽  
Generation Times ◽  
Effects Of Ph ◽  
Early Phases

The effects of pH values and NaCl concentrations on the growth rates of five species of lactic acid bacteria commonly associated with the sauerkraut fermentation were determined in filter-sterilized cabbage juice. Growth rates of all cultures, with the exception of Pediococcus cerevisiae, were retarded by addition of salt, lower pH, or interaction of both pH and salt. Based upon lag and generation times, P. cerevisiae was the culture most tolerant to the pH and salt concentration employed, whereas Streptococcus faecalis was the most sensitive species. Of the heterofermentative cultures, Lactobacillus brevis was less subject to growth inhibition than Leuconostoc mesenteroides. Under conditions simulating those found during the initial phases of the sauerkraut fermentation (2.25% salt, pH 6.2), L. mesenteroides displayed the shortest lag and generation times of all cultures examined. This rapid growth rate coupled with a marked accelerated death rate may explain, in part, the reason this species is both the first to dominate and the first to die during the early phases of the sauerkraut fermentation. Although cabbage juice previously fermented by L. mesenteroides appears to inhibit growth of P. cerevisiae, it had no apparent inhibitory or stimulatory effects on the other cultures.

scholarly journals Anomalous placement of introns in a member of the intermediate filament multigene family: an evolutionary conundrum.

1986 ◽  
Vol 6 (5) ◽  
pp. 1529-1534 ◽  
Author(s):  
S A Lewis ◽  
N J Cowan
Keyword(s):  
Glial Fibrillary Acidic Protein ◽  
Intermediate Filament ◽  
Multigene Family ◽  
Protein Gene ◽  
Sequence Data ◽  
Complete Sequence ◽  
Acidic Protein ◽  
Type I ◽  
Neurofilament Protein ◽  
Gene Encoding

The origin of introns and their role (if any) in gene expression, in the evolution of the genome, and in the generation of new expressed sequences are issues that are understood poorly, if at all. Multigene families provide a favorable opportunity for examining the evolutionary history of introns because it is possible to identify changes in intron placement and content since the divergence of family members from a common ancestral sequence. Here we report the complete sequence of the gene encoding the 68-kilodalton (kDa) neurofilament protein; the gene is a member of the intermediate filament multigene family that diverged over 600 million years ago. Five other members of this family (desmin, vimentin, glial fibrillary acidic protein, and type I and type II keratins) are encoded by genes with six or more introns at homologous positions. To our surprise, the number and placement of introns in the 68-kDa neurofilament protein gene were completely anomalous, with only three introns, none of which corresponded in position to introns in any characterized intermediate filament gene. This finding was all the more unexpected because comparative amino acid sequence data suggest a closer relationship of the 68-kDa neurofilament protein to desmin, vimentin, and glial fibrillary acidic protein than between any of these three proteins and the keratins. It appears likely that an mRNA-mediated transposition event was involved in the evolution of the 68-kDa neurofilament protein gene and that subsequent events led to the acquisition of at least two of the three introns present in the contemporary sequence.

scholarly journals Characterization of the Different Dextransucrase Activities Excreted in Glucose, Fructose, or Sucrose Medium byLeuconostoc mesenteroides NRRL B-1299

1998 ◽  
Vol 64 (4) ◽  
pp. 1298-1302 ◽  
Author(s):  
Marguerite Dols ◽  
M. Remaud-Simeon ◽  
R. M. Willemot ◽  
M. Vignon ◽  
P. Monsan
Keyword(s):  
Gel Electrophoresis ◽  
Leuconostoc Mesenteroides ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Traditional Culture ◽  
Culture Conditions ◽  
Acceptor Reaction ◽  
Sucrose Medium ◽  
Molecular Masses

ABSTRACT When grown in glucose or fructose medium in the absence of sucrose,Leuconostoc mesenteroides NRRL B-1299 produces two distinct extracellular dextransucrases named glucose glucosyltransferase (GGT) and fructose glucosyltransferase (FGT). The production level of GGT and FGT is 10 to 20 times lower than that of the extracellular dextransucrase sucrose glucosyltransferase (SGT) produced on sucrose medium (traditional culture conditions). GGT and FGT were concentrated by ultrafiltration before sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. Their molecular masses were 183 and 186 kDa, respectively, differing from the 195 kDa of SGT. The structural analysis of the dextran produced from sucrose and of the oligosaccharides synthesized by acceptor reaction in the presence of maltose showed that GGT and FGT are two different enzymes not previously described for this strain. The polymer synthesized by GGT contains 30% α(1→2) linkages, while FGT catalyzes the synthesis of a linear dextran only composed of α(1→6) linkages.

scholarly journals Sequence of the Genome of the Temperate, Serotype-Converting,Pseudomonas aeruginosa Bacteriophage D3

2000 ◽  
Vol 182 (21) ◽  
pp. 6066-6074 ◽  
Author(s):  
Andrew M. Kropinski
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Sequence Similarity ◽  
Complete Sequence ◽  
Open Reading Frames ◽  
Gene Encoding ◽  
Virus Family ◽  
Double Stranded Dna ◽  
High Degree ◽  
Phage Proteins ◽  
Reading Frames

ABSTRACT Temperate bacteriophage D3, a member of the virus familySiphoviridae, is responsible for serotype conversion in its host, Pseudomonas aeruginosa. The complete sequence of the double-stranded DNA genome has been determined. The 56,426 bp contains 90 putative open reading frames (ORFs) and four genes specifying tRNAs. The latter are specific for methionine (AUG), glycine (GGA), asparagine (AAC), and threonine (ACA). The tRNAs may function in the translation of certain highly expressed proteins from this relatively AT-rich genome. D3 proteins which exhibited a high degree of sequence similarity to previously characterized phage proteins included the portal, major head, tail, and tail tape measure proteins, endolysin, integrase, helicase, and NinG. The layout of genes was reminiscent of lambdoid phages, with the exception of the placement of the endolysin gene, which parenthetically also lacked a cognate holin. The greatest sequence similarity was found in the morphogenesis genes to coliphages HK022 and HK97. Among the ORFs was discovered the gene encoding the fucosamine O-acetylase, which is in part responsible for the serotype conversion events.

CONTROL OF CLOSTRIDIUM BOTULINUM AND STAPHYLOCOCCUS AUREUS IN SEMI-PRESERVED MEAT PRODUCTS

1972 ◽  
Vol 35 (9) ◽  
pp. 514-523 ◽  
Author(s):  
Han's Riemann ◽  
W. H. Lee ◽  
C. Genigeorgis
Keyword(s):  
Staphylococcus Aureus ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Clostridium Botulinum ◽  
Meat Product ◽  
Meat Products ◽  
Rapid Decline ◽  
Ph Values ◽  
And Staphylococcus Aureus ◽  
Brine Concentration

Clostridium botulinum and Staphylococcus aureus are naturally occurring contaminants in semi-preserved meat products. They can be inhibited by (a) storage below 3 C, (b) 10% sodium chloride (brine concentration), (c) pH values below 4.5, or (d) proper combinations of these factors. However, most meat products do not have the pH values and brine concentrations required to completely inhibit C. botulinum and S. aureus and there is always a risk of temperature abuse. Improved safety can be achieved by adding 1% or more glucose to the product. The glucose will, in the event of temperature abuse, generally be fermented to lactic acid by the indigenous microflora in the product. As a result, the pH value drops to a level at which the brine concentration is sufficient to inhibit C. botulinum and S. aureus. A better approach to safety is to add, together with glucose, a radiation-killed preparation of lactic acid bacteria, e.g., Pediococcus cerevisiae. Such preparations cause a rapid decline in pH only when the product is exposed to a high temperature, and they are stable during storage of meat products. Addition of irradiated lactic acid bacteria to meat products has not yet been officially approved. Another way to improve the safety of semi-preserved meat is to add sufficient glucono-delta-lactone to reduce the initial pH of the product to a level at which the salt concentration is inhibitory. Use of larger amounts of glucono-delta-lactone may result in flavor and color problems even when the meat product is kept at refrigeration temperatures.

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