scholarly journals Identification and Partial Characterization of Extracellular Aspartic Protease Genes from Metschnikowia pulcherrima IWBT Y1123 and Candida apicola IWBT Y1384

2012 ◽  
Vol 78 (19) ◽  
pp. 6838-6849 ◽  
Author(s):  
Vernita J. Reid ◽  
Louwrens W. Theron ◽  
Maret du Toit ◽  
Benoit Divol

ABSTRACTThe extracellular acid proteases of non-Saccharomyceswine yeasts may fulfill a number of roles in winemaking, which include increasing the available nitrogen sources for the growth of fermentative microbes, affecting the aroma profile of the wine, and potentially reducing protein haze formation. These proteases, however, remain poorly characterized, especially at genetic level. In this study, two extracellular aspartic protease-encoding genes were identified and sequenced, from two yeast species of enological origin: one gene fromMetschnikowia pulcherrimaIWBT Y1123, namedMpAPr1, and the other gene fromCandida apicolaIWBT Y1384, namedCaAPr1.In silicoanalysis of these two genes revealed a number of features peculiar to aspartic protease genes, and both the MpAPr1 and CaAPr1 putative proteins showed homology to proteases of yeast genera. Heterologous expression ofMpAPr1inSaccharomyces cerevisiaeYHUM272 confirmed that it encodes an aspartic protease. MpAPr1 production, which was shown to be constitutive, and secretion were confirmed in the presence of bovine serum albumin (BSA), casein, and grape juice proteins. TheMpAPr1gene was found to be present in 12 otherM. pulcherrimastrains; however, plate assays revealed that the intensity of protease activity was strain dependent and unrelated to the gene sequence.

2015 ◽  
Vol 197 (17) ◽  
pp. 2831-2839 ◽  
Author(s):  
Katherine A. Miller ◽  
Robert S. Phillips ◽  
Paul B. Kilgore ◽  
Grady L. Smith ◽  
Timothy R. Hoover

ABSTRACTSalmonella entericserovar Typhimurium, a major cause of food-borne illness, is capable of using a variety of carbon and nitrogen sources. Fructoselysine and glucoselysine are Maillard reaction products formed by the reaction of glucose or fructose, respectively, with the ε-amine group of lysine. We report here thatS. Typhimurium utilizes fructoselysine and glucoselysine as carbon and nitrogen sources via a mannose family phosphotransferase (PTS) encoded bygfrABCD(glucoselysine/fructoselysine PTS components EIIA, EIIB, EIIC, and EIID; locus numbers STM14_5449 to STM14_5454 inS. Typhimurium 14028s). Genes coding for two predicted deglycases within thegfroperon,gfrEandgfrF, were required for growth with glucoselysine and fructoselysine, respectively. GfrF demonstrated fructoselysine-6-phosphate deglycase activity in a coupled enzyme assay. The biochemical and genetic analyses were consistent with a pathway in which fructoselysine and glucoselysine are phosphorylated at the C-6 position of the sugar by the GfrABCD PTS as they are transported across the membrane. The resulting fructoselysine-6-phosphate and glucoselysine-6-phosphate subsequently are cleaved by GfrF and GfrE to form lysine and glucose-6-phosphate or fructose-6-phosphate. Interestingly, althoughS. Typhimurium can use lysine derived from fructoselysine or glucoselysine as a sole nitrogen source, it cannot use exogenous lysine as a nitrogen source to support growth. Expression ofgfrABCDEFwas dependent on the alternative sigma factor RpoN (σ54) and an RpoN-dependent LevR-like activator, which we designated GfrR.IMPORTANCESalmonellaphysiology has been studied intensively, but there is much we do not know regarding the repertoire of nutrients these bacteria are able to use for growth. This study shows that a previously uncharacterized PTS and associated enzymes function together to transport and catabolize fructoselysine and glucoselysine. Knowledge of the range of nutrients thatSalmonellautilizes is important, as it could lead to the development of new strategies for reducing the load ofSalmonellain food animals, thereby mitigating its entry into the human food supply.


2021 ◽  
Vol 7 (6) ◽  
Author(s):  
Paolo Emidio Costantini ◽  
Andrea Firrincieli ◽  
Stefano Fedi ◽  
Carola Parolin ◽  
Carlo Viti ◽  
...  

The vaginal microbiota, normally characterized by lactobacilli presence, is crucial for vaginal health. Members belonging to L. crispatus and L. gasseri species exert crucial protective functions against pathogens, although a total comprehension of factors that influence their dominance in healthy women is still lacking. Here we investigated the complete genome sequence and comprehensive phenotypic profile of L. crispatus strain BC5 and L. gasseri strain BC12, two vaginal strains featured by anti-bacterial and anti-viral activities. Phenotype microarray (PM) results revealed an improved capacity of BC5 to utilize different carbon sources as compared to BC12, although some specific carbon sources that can be associated to the human diet were only metabolized by BC12, i.e. uridine, amygdalin, tagatose. Additionally, the two strains were mostly distinct in the capacity to utilize the nitrogen sources under analysis. On the other hand, BC12 showed tolerance/resistance towards twice the number of stressors (i.e. antibiotics, toxic metals etc.) with respect to BC5. The divergent phenotypes observed in PM were supported by the identification in either BC5 or BC12 of specific genetic determinants that were found to be part of the core genome of each species. The PM results in combination with comparative genome data provide insights into the possible environmental factors and genetic traits supporting the predominance of either L. crispatus BC5 or L. gasseri BC12 in the vaginal niche, giving also indications for metabolic predictions at the species level.


2013 ◽  
Vol 79 (19) ◽  
pp. 6050-6058 ◽  
Author(s):  
Christoph Knuf ◽  
Intawat Nookaew ◽  
Stephen H. Brown ◽  
Michael McCulloch ◽  
Alan Berry ◽  
...  

ABSTRACTMalic acid has great potential for replacing petrochemical building blocks in the future. For this application, high yields, rates, and titers are essential in order to sustain a viable biotechnological production process. Natural high-capacity malic acid producers like the malic acid producerAspergillus flavushave so far been disqualified because of special growth requirements or the production of mycotoxins. AsA. oryzaeis a very close relative or even an ecotype ofA. flavus, it is likely that its high malic acid production capabilities with a generally regarded as safe (GRAS) status may be combined with already existing large-scale fermentation experience. In order to verify the malic acid production potential, two wild-type strains, NRRL3485 and NRRL3488, were compared in shake flasks. As NRRL3488 showed a volumetric production rate twice as high as that of NRRL3485, this strain was selected for further investigation of the influence of two different nitrogen sources on malic acid secretion. The cultivation in lab-scale fermentors resulted in a higher final titer, 30.27 ± 1.05 g liter−1, using peptone than the one of 22.27 ± 0.46 g liter−1obtained when ammonium was used. Through transcriptome analysis, a binding site similar to the one of theSaccharomyces cerevisiaeyeast transcription factor Msn2/4 was identified in the upstream regions of glycolytic genes and the cytosolic malic acid production pathway from pyruvate via oxaloacetate to malate, which suggests that malic acid production is a stress response. Furthermore, the pyruvate carboxylase reaction was identified as a target for metabolic engineering, after it was confirmed to be transcriptionally regulated through the correlation of intracellular fluxes and transcriptional changes.


2019 ◽  
Vol 50 (5) ◽  
pp. 987-998 ◽  
Author(s):  
Juliane Barroso Leal ◽  
Juçara Barroso Leal ◽  
Joaline Barroso Portela Leal ◽  
Yan de Lima Borges ◽  
Maria Ivone Leal de Moura ◽  
...  

Purpose This paper aims to verify the effect of 12 weeks of grape juice (GJ) consumption associated with aerobic exercise on the variation of the hypertensive elderly pressure. Design/methodology/approach A total of 45 hypertensive elderly of both sexes were distributed into: control group (CG, n = 10), exercise group (EG, n = 10), juice group (JG, n = 12) and juice and exercise group (JEG, n = 13). Blood pressure and heart rate were checked weekly before exercise in JG and JEG, and before and after intervention in all groups, with JG and JEG supplemented with 200 mL of GJ. Three weekly sessions of moderate walking were applied. Findings There was a reduction in EG, JG and JEG for systolic pressure and diastolic only for JG and JEG. The GJ consumption to the practice of aerobic exercise provided reductions in the arterial pressure of hypertensive, in addition to stabilization of the diastolic pressure. Research limitations/implications Although the objective of the study was to compare the effect and value of intervention with controls, the study had no intervention in food consumption, which could have led to more significant results. There was a limitation in the control drink, leading the study not to be blind, which may have impaired the results. However, it is probably not a bias, as the groups were divided by residence area, and therefore, had no direct contact with the other groups. Another limitation was that the sample size was still small, which would lead to more reliable results. Finally, although the existing limitations cannot be disregarded, the results of this research are very promising, especially when the objective is the effect of GJ and aerobic exercise on blood pressure, with the possibility of implementing supplemental GJ and the inclusion or not of exercise to the hypertensive elderly. Originality/value The paper deals with the benefits of GJ consumption associated with aerobic physical exercise on the blood pressure of elderly hypertensive patients. Considering that GJ along with physical exercise was enough to reduce the blood pressure of hypertensive elderly, this may be a new model to be used to reduce and/or control blood pressure, and GJ and the exercise to be part of the daily life of the population.


2017 ◽  
Vol 37 (14) ◽  
Author(s):  
Mirai Tanigawa ◽  
Tatsuya Maeda

ABSTRACT Evolutionarily conserved target of rapamycin (TOR) complex 1 (TORC1) responds to nutrients, especially amino acids, to promote cell growth. In the yeast Saccharomyces cerevisiae, various nitrogen sources activate TORC1 with different efficiencies, although the mechanism remains elusive. Leucine, and perhaps other amino acids, was reported to activate TORC1 via the heterodimeric small GTPases Gtr1-Gtr2, the orthologues of the mammalian Rag GTPases. More recently, an alternative Gtr-independent TORC1 activation mechanism that may respond to glutamine was reported, although its molecular mechanism is not clear. In studying the nutrient-responsive TORC1 activation mechanism, the lack of an in vitro assay hinders associating particular nutrient compounds with the TORC1 activation status, whereas no in vitro assay that shows nutrient responsiveness has been reported. In this study, we have developed a new in vitro TORC1 kinase assay that reproduces, for the first time, the nutrient-responsive TORC1 activation. This in vitro TORC1 assay recapitulates the previously predicted Gtr-independent glutamine-responsive TORC1 activation mechanism. Using this system, we found that this mechanism specifically responds to l-glutamine, resides on the vacuolar membranes, and involves a previously uncharacterized Vps34-Vps15 phosphatidylinositol (PI) 3-kinase complex and the PI-3-phosphate [PI(3)P]-binding FYVE domain-containing vacuolar protein Pib2. Thus, this system was proved to be useful for dissecting the glutamine-responsive TORC1 activation mechanism.


2009 ◽  
Vol 112 (1) ◽  
pp. 169-177 ◽  
Author(s):  
Luís Batista ◽  
Sara Monteiro ◽  
Virgílio B. Loureiro ◽  
Artur R. Teixeira ◽  
Ricardo B. Ferreira
Keyword(s):  

2018 ◽  
Vol 92 (21) ◽  
Author(s):  
Gabriel Robles Luna ◽  
Eduardo José Peña ◽  
María Belén Borniego ◽  
Manfred Heinlein ◽  
María Laura García

ABSTRACTPlant virus cell-to-cell movement is an essential step in viral infections. This process is facilitated by specific virus-encoded movement proteins (MPs), which manipulate the cell wall channels between neighboring cells known as plasmodesmata (PD). Citrus psorosis virus (CPsV) infection in sweet orange involves the formation of tubule-like structures within PD, suggesting that CPsV belongs to “tubule-forming” viruses that encode MPs able to assemble a hollow tubule extending between cells to allow virus movement. Consistent with this hypothesis, we show that the MP of CPsV (MPCPsV) indeed forms tubule-like structures at PD upon transient expression inNicotiana benthamianaleaves. Tubule formation by MPCPsVdepends on its cleavage capacity, mediated by a specific aspartic protease motif present in its primary sequence. A single amino acid mutation in this motif abolishes MPCPsVcleavage, alters the subcellular localization of the protein, and negatively affects its activity in facilitating virus movement. The amino-terminal 34-kDa cleavage product (34KCPsV), but not the 20-kDa fragment (20KCPsV), supports virus movement. Moreover, similar to tubule-forming MPs of other viruses, MPCPsV(and also the 34KCPsVcleavage product) can homooligomerize, interact with PD-located protein 1 (PDLP1), and assemble tubule-like structures at PD by a mechanism dependent on the secretory pathway. 20KCPsVretains the protease activity and is able to cleave a cleavage-deficient MPCPsVintrans. Altogether, these results demonstrate that CPsV movement depends on the autolytic cleavage of MPCPsVby an aspartic protease activity, which removes the 20KCPsVprotease and thereby releases the 34KCPsVprotein for PDLP1-dependent tubule formation at PD.IMPORTANCEInfection by citrus psorosis virus (CPsV) involves a self-cleaving aspartic protease activity within the viral movement protein (MP), which results in the production of two peptides, termed 34KCPsVand 20KCPsV, that carry the MP and viral protease activities, respectively. The underlying protease motif within the MP is also found in the MPs of other members of theAspiviridaefamily, suggesting that protease-mediated protein processing represents a conserved mechanism of protein expression in this virus family. The results also demonstrate that CPsV and potentially other ophioviruses move by a tubule-guided mechanism. Although several viruses from different genera were shown to use this mechanism for cell-to-cell movement, our results also demonstrate that this mechanism is controlled by posttranslational protein cleavage. Moreover, given that tubule formation and virus movement could be inhibited by a mutation in the protease motif, targeting the protease activity for inactivation could represent an important approach for ophiovirus control.


Chemosphere ◽  
2020 ◽  
Vol 241 ◽  
pp. 125083
Author(s):  
S.A. Pechkovskaya ◽  
N.A. Knyazev ◽  
O.V. Matantseva ◽  
A.K. Emelyanov ◽  
I.V. Telesh ◽  
...  

2019 ◽  
Vol 8 (17) ◽  
Author(s):  
Sarah Bouhired ◽  
Oliver Rupp ◽  
Jochen Blom ◽  
Till F. Schäberle ◽  
Andrea Schiefer ◽  
...  

Myxobacteria are a source of unique metabolites, including corallopyronin A (CorA), a promising antibiotic agent in preclinical development for the treatment of filariasis. To investigate the production of CorA on the genetic level, we present the complete 9.6-Mb genome sequence of the CorA producer Corallococcus coralloides B035.


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