scholarly journals Influence of the mannoproteins of different strains of Starmerella bacillaris used in single and sequential fermentations on foamability, tartaric and protein stabilities of wines

OENO One ◽  
2020 ◽  
Vol 54 (2) ◽  
Author(s):  
Wilson Josè Fernandes Lemos Junior ◽  
Chiara Nadai ◽  
Luca Rolle ◽  
Eliana Da Silva Gulao ◽  
Maria Helena Miguez da Rocha Leãoe ◽  
...  
Keyword(s):  
Alcoholic Fermentation ◽  
Foaming Properties ◽  
Carbohydrate Composition ◽  
Single Strain ◽  
Different Strains ◽  
Protein Stabilisation

Aim: In this work, seven strains of Starmerella bacillaris were analysed for their ability to release polysaccharides during alcoholic fermentation (AF), both in single-strain and in sequential AF together with Saccharomyces cerevisiae.Methods and Results: A synthetic polysaccharide-free must was used to characterise the mannoproteins (MPs) released. The MPs were quantified, characterised in terms of carbohydrate composition, and tested to assess their ability to reduce protein and tartrate instabilities and their ability to affect the foaming properties of wine.Conclusions: All the tested strains in sequential AF increased the total MPs production. Moreover, the strains affected the MPs properties in different ways regarding tartaric and protein stabilities. The MPs released in sequential AF by some S. bacillaris strains showed a significant effect on protein stabilisation and tartaric stability. An effect on the foamability was found for MPs obtained in single-strain AFs of S. bacillaris.Significance and impact of the study: An improvement in wine stability can be achieved using the sequential AF.

Characterization by pyocine typing and serotyping of oral and sputum strains of Pseudomonas aeruginosa isolated from cystic fibrosis patients

1987 ◽  
Vol 33 (3) ◽  
pp. 221-225 ◽  
Author(s):  
Kunio Komiyama ◽  
Brian F. Habbick ◽  
Tom Martin ◽  
Satwant K. Tumber
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Oral Cavity ◽  
Buccal Mucosa ◽  
Single Strain ◽  
Ecological Sites ◽  
Dental Plaques ◽  
Different Strains

Oral and sputum isolates of Pseudomonas aeruginosa in patients with cystic fibrosis were investigated. Of the 17 patients studied, 12 patients (71%) yielded both mucoid and nonmucoid variants of Pseudomonas aeruginosa from sputum and (or) various oral ecological sites, such as buccal mucosa, tongue dorsum, dental plaques, and saliva. A total of 51 strains of mucoid and nonmucoid Pseudomonas aeruginosa were isolated from these patients and were phenotypically characterized by both pyocine typing and serotyping. Five patients (42%) were colonized or infected by a single strain of Pseudomonas aeruginosa, whereas 7 patients (58%) were cocolonized or coinfected by two or more phenotypically different strains of Pseudomonas aeruginosa. To understand the mechanisms involved in Pseudomonas aeruginosa colonization, it may be necessary to identify multiple isolates of Pseudomonas aeruginosa not only from the sputum but also from the various oral ecological sites and to further explore the role of the oral cavity in this colonization.

scholarly journals Mining the Microbiota of the Neonatal Gastrointestinal Tract for Conjugated Linoleic Acid-Producing Bifidobacteria

2004 ◽  
Vol 70 (8) ◽  
pp. 4635-4641 ◽  
Author(s):  
E. Rosberg-Cody ◽  
R. P. Ross ◽  
S. Hussey ◽  
C. A. Ryan ◽  
B. P. Murphy ◽  
...  
Keyword(s):  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Bifidobacterium Bifidum ◽  
Genomic Diversity ◽  
Gas Liquid Chromatography ◽  
Fecal Material ◽  
Single Strain ◽  
Different Strains

ABSTRACT This study was designed to isolate different strains of the genus Bifidobacterium from the fecal material of neonates and to assess their ability to produce the cis-9, trans-11 conjugated linoleic acid (CLA) isomer from free linoleic acid. Fecal material was collected from 24 neonates aged between 3 days and 2 months in a neonatal unit (Erinville Hospital, Cork, Ireland). A total of 46 isolates from six neonates were confirmed to be Bifidobacterium species based on a combination of the fructose-6-phosphate phosphoketolase assay, RAPD [random(ly) amplified polymorphic DNA] PCR, pulsed-field gel electrophoresis (PFGE), and partial 16S ribosomal DNA sequencing. Interestingly, only 1 of the 11 neonates that had received antibiotic treatment produced bifidobacteria. PFGE after genomic digestion with the restriction enzyme XbaI demonstrated that the bifidobacteria population displayed considerable genomic diversity among the neonates, with each containing between one and five dominant strains, whereas 11 different macro restriction patterns were obtained. In only one case did a single strain appear in two neonates. All genetically distinct strains were then screened for CLA production after 72 h of incubation with 0.5 mg of free linoleic acid ml−1 by using gas-liquid chromatography. The most efficient producers belonged to the species Bifidobacterium breve, of which two different strains converted 29 and 27% of the free linoleic acid to the cis-9, trans-11 isomer per microgram of dry cells, respectively. In addition, a strain of Bifidobacterium bifidum showed a conversion rate of 18%/μg dry cells. The ability of some Bifidobacterium strains to produce CLA could be another human health-promoting property linked to members of the genus, given that this metabolite has demonstrated anticarcinogenic activity in vitro and in vivo.

scholarly journals Systematic Analysis of Efflux Pump-Mediated Antiseptic Resistance in Staphylococcus aureus Suggests a Need for Greater Antiseptic Stewardship

mSphere ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Patrick T. LaBreck ◽  
Audrey C. Bochi-Layec ◽  
Joshua Stanbro ◽  
Gina Dabbah-Krancher ◽  
Mark P. Simons ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Efflux Pump ◽  
Efflux Pumps ◽  
Transcriptional Analysis ◽  
Systematic Analysis ◽  
Daily Lives ◽  
Single Strain ◽  
Content Type ◽  
Subinhibitory Concentrations ◽  
Different Strains

ABSTRACT Staphylococcus aureus-associated infections can be difficult to treat due to multidrug resistance. Thus, infection prevention is critical. Cationic antiseptics, such as chlorhexidine (CHX) and benzalkonium chloride (BKC), are liberally used in health care and community settings to prevent infection. However, increased administration of antiseptics has selected for S. aureus strains that show reduced susceptibilities to cationic antiseptics. This increased resistance has been associated with carriage of specific efflux pumps (QacA, QacC, and NorA). Since prior published studies focused on different strains and on strains carrying only a single efflux gene, the relative importance of these various systems to antiseptic resistance is difficult to ascertain. To overcome this, we engineered a collection of isogenic S. aureus strains that harbored norA, qacA, and qacC, individually or in combination. MIC assays showed that qacA was associated with increased resistance to CHX, cetrimide (CT), and BKC, qacC was associated with resistance to CT and BKC, and norA was necessary for basal-level resistance to the majority of tested antiseptics. When all three pumps were present in a single strain, an additive effect was observed in the MIC for CT. Transcriptional analysis revealed that expression of qacA and norA was significantly induced following exposure to BKC. Alarmingly, in a strain carrying qacA and norA, preexposure to BKC increased CHX tolerance. Overall, our results reveal increased antiseptic resistance in strains carrying multiple efflux pumps and indicate that preexposure to BKC, which is found in numerous daily-use products, can increase CHX tolerance. IMPORTANCE S. aureus remains a significant cause of disease within hospitals and communities. To reduce the burden of S. aureus infections, antiseptics are ubiquitously used in our daily lives. Furthermore, many antiseptic compounds are dual purpose and are found in household products. The increased abundance of antiseptic compounds has selected for S. aureus strains that carry efflux pumps that increase resistance to antiseptic compounds; however, the effect of carrying multiple pumps within S. aureus is unclear. We demonstrated that an isogenic strain carrying multiple efflux pumps had an additive resistance phenotype to cetrimide. Moreover, in a strain carrying qacA and norA, increased chlorhexidine tolerance was observed after the strain was preexposed to subinhibitory concentrations of a different common-use antiseptic. Taken together, our findings demonstrate cooperation between antiseptic resistance efflux pumps and suggest that their protective phenotype may be exacerbated by priming with subinhibitory concentrations of household antiseptics.

scholarly journals OXIDASE REACTION OF VARIOUS GROUPS OF BACTERIA

1923 ◽  
Vol 38 (3) ◽  
pp. 291-307
Author(s):  
Lloyd D. Felton
Keyword(s):  
Guinea Pig ◽  
Horse Serum ◽  
Ion Concentration ◽  
Streptococcus Viridans ◽  
High Concentration ◽  
Single Strain ◽  
Fresh Serum ◽  
Different Strains ◽  
Oxidase Reaction ◽  
Slight Amount

1. A simple technique is described for studying the oxidase action of bacteria by means of the oxidation of p-aminoleucomalachite green. 2. It is shown that pneumococci under aerobic conditions produced an oxidase when grown on suitable medium. The sera of any of seven different animal species constitute such a medium, the degree of oxidation by the pneumococcus depending upon the animal from which the serum was taken—rat, guinea pig, rabbit, horse, man, cat, and chicken in order of diminishing suitability. 3. Conditions favoring the oxidation of p-aminoleucomalachite green by a single strain of pneumococci are: the presence of a slight amount of hemoglobin, dextrose, H ion concentration on the add side, and heating of fresh serum for 30 minutes at 56°C. Conditions preventing the oxidation are: sterilized meat infusion, 1 per cent peptone, plain broth, a high concentration of hemoglobin, and absence of oxygen. In a quantitative fashion, meat infusion, 1 per cent peptone, and plain broth interfere with the suitability of serum as a substratum of oxidase production by the pneumococcus. 4. Twenty-three microbic species were studied with reference to oxidative power. They were grown upon 10 per cent horse serum, with and without dextrose, upon 10 per cent guinea pig serum, and upon plain broth. Only three of the twenty-three gave evidence of oxidative power as tested by p-aminoleucomalachite green; namely, the pneumococcus, Streptococcus viridans, and Streptococcus hæmolyticus. Among the strains, of these three pneumococci gave the most intense reaction, after which Streptococcus viridans and Streptococcus hæmolyticus follow in the order named, but with a noticeable variation among the different strains of Streptococcus hæmolyticus. 5. Hemolytic streptococci of human and bovine origin were studied. The only variation in the type of reaction was manifested by the streptococci of milk and cheese origin. Strains from these sources showed definitely the least oxidase activity. Streptococci from mastitis and cow's udder were indistinguishable by the test from the hemolytic streptococci of human origin.

scholarly journals Designing microbial communities to maximize the thermodynamic driving force for the production of chemicals

2021 ◽  
Vol 17 (6) ◽  
pp. e1009093
Author(s):  
Pavlos Stephanos Bekiaris ◽  
Steffen Klamt
Keyword(s):  
Microbial Communities ◽  
Division Of Labor ◽  
Driving Force ◽  
Single Species ◽  
Microbial Consortia ◽  
Biotechnological Applications ◽  
Single Strain ◽  
Metabolic Burden ◽  
Thermodynamic Driving Force ◽  
Different Strains

Microbial communities have become a major research focus due to their importance for biogeochemical cycles, biomedicine and biotechnological applications. While some biotechnological applications, such as anaerobic digestion, make use of naturally arising microbial communities, the rational design of microbial consortia for bio-based production processes has recently gained much interest. One class of synthetic microbial consortia is based on specifically designed strains of one species. A common design principle for these consortia is based on division of labor, where the entire production pathway is divided between the different strains to reduce the metabolic burden caused by product synthesis. We first show that classical division of labor does not automatically reduce the metabolic burden when metabolic flux per biomass is analyzed. We then present ASTHERISC (Algorithmic Search of THERmodynamic advantages in Single-species Communities), a new computational approach for designing multi-strain communities of a single-species with the aim to divide a production pathway between different strains such that the thermodynamic driving force for product synthesis is maximized. ASTHERISC exploits the fact that compartmentalization of segments of a product pathway in different strains can circumvent thermodynamic bottlenecks arising when operation of one reaction requires a metabolite with high and operation of another reaction the same metabolite with low concentration. We implemented the ASTHERISC algorithm in a dedicated program package and applied it on E. coli core and genome-scale models with different settings, for example, regarding number of strains or demanded product yield. These calculations showed that, for each scenario, many target metabolites (products) exist where a multi-strain community can provide a thermodynamic advantage compared to a single strain solution. In some cases, a production with sufficiently high yield is thermodynamically only feasible with a community. In summary, the developed ASTHERISC approach provides a promising new principle for designing microbial communities for the bio-based production of chemicals.

Relationship between H2S-producing strains of wine yeast and different fermentation conditions

1999 ◽  
Vol 45 (4) ◽  
pp. 343-346 ◽  
Author(s):  
C Tamayo ◽  
J Ubeda ◽  
A Briones
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Stainless Steel ◽  
Hydrogen Sulphide ◽  
Yeast Strain ◽  
Alcoholic Fermentation ◽  
Wine Yeast ◽  
Fermentation Conditions ◽  
Factors Affecting ◽  
Different Strains ◽  
The Relationship

Hydrogen sulphide formation is a problem in winemaking. One of the factors affecting formation of this unwanted metabolite is the yeast strain responsible for the process. In this experiment wines were made on a laboratory scale with different strains of H2S-producing Saccharomyces cerevisiae. The relationship between H2S production and various fermentation conditions was examined (SO2, methionine, (NH4)2SO4, (NH4)3PO4, steel, and steel-lees). The results show that in fermentations in the presence of stainless steel and lees, H2S formation is high but declines when (NH4)3PO4is added to the must.Key words: H2S formation, wine-yeast, steel-lees, wine-making, alcoholic fermentation.

scholarly journals Vaccination of C57BL/10 mice against cutaneous leishmaniasis using killed promastigotes of different strains and species of Leishmania

2002 ◽  
Vol 35 (2) ◽  
pp. 125-132 ◽  
Author(s):  
Wilson Mayrink ◽  
Gilmara Cristina dos Santos ◽  
Vicente de Paulo Coelho Peixoto de Toledo ◽  
Tânia Mara Pinto Dabés Guimarães ◽  
George Luis Lins Machado-Coelho ◽  
...  
Keyword(s):  
Cell Culture ◽  
Spleen Cell ◽  
Cutaneous Leishmaniasis ◽  
Protective Immunity ◽  
Leishmania Amazonensis ◽  
Ifn Gamma ◽  
Single Strain ◽  
Spleen Cell Culture ◽  
Monovalent Vaccine ◽  
Different Strains

Antigenic extracts from five Leishmania stocks were used to vaccinate C57BL/10 mice. The Leishvacin® and PH8 monovalent vaccine yielded the highest IFN-gamma levels in the supernatants of spleen cell culture from vaccinated animals. Each single strain immunized group showed evidence of protective immunity six months after the challenge with promastigotes of Leishmania (Leishmania) amazonensis. No differences were detected between the vaccinated groups. It can be concluded that vaccines composed of single Leishmania stocks can provide protection to C57BL/10 mice against L. (L.) amazonensis infection.

scholarly journals Exposure of Hepatitis C Virus (HCV) RNA-Positive Recipients to HCV RNA-Positive Blood Donors Results in Rapid Predominance of a Single Donor Strain and Exclusion and/or Suppression of the Recipient Strain

2001 ◽  
Vol 75 (5) ◽  
pp. 2059-2066 ◽  
Author(s):  
Tomasz Laskus ◽  
Lian-Fu Wang ◽  
Marek Radkowski ◽  
Hugo Vargas ◽  
Marek Nowicki ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Hcv Rna ◽  
Donor Strain ◽  
Serum Samples ◽  
Simultaneous Exposure ◽  
Single Strain ◽  
Single Donor ◽  
Different Strains

ABSTRACT We have analyzed three cases of hepatitis C virus (HCV)-infected recipients who received blood from HCV-infected donors. Two recipients were exposed to two different HCV RNA-positive donors, and one was exposed to a single donor. All parental genomes from the actual infecting units of blood and the recipients were defined, and their presence in the follow-up serum samples was determined using sensitive strain-specific assays. The strain from one of the donors was found to predominate in all recipients' serum samples collected throughout the follow-up period of 10 to 30 months. In two recipients exposed to two infected donors, the strain from the second donor was occasionally found at very low level. However, the original recipients' strains were not detected. Our observations show that HCV-infected individuals can be superinfected with different strains, and this event may lead to eradication or suppression of the original infecting strain. Furthermore, our findings demonstrate that simultaneous exposure to multiple HCV strains may result in concomitant infection by more than one strain, although a single strain could rapidly establish its dominance. The results of the present study suggest the existence of competition among infecting HCV strains which determines the ultimate outcome of multiple HCV exposure.

scholarly journals Spatiotemporal dynamics of synthetic microbial consortia in microfluidic devices

2019 ◽  
Author(s):  
Razan N. Alnahhas ◽  
James J. Winkle ◽  
Andrew J. Hirning ◽  
Bhargav Karamched ◽  
William Ott ◽  
...  
Keyword(s):  
Temporal Dynamics ◽  
Relative Proportion ◽  
Microfluidic Devices ◽  
Spatiotemporal Dynamics ◽  
Microbial Consortia ◽  
Intercellular Signaling ◽  
Single Strain ◽  
Trap Size ◽  
Different Strains ◽  
Synthetic Microbial Consortia

AbstractSynthetic microbial consortia consist of two or more engineered strains that grow together and share the same resources. When intercellular signaling pathways are included in the engineered strains, close proximity of the microbes can generate complex dynamic behaviors that are difficult to obtain using a single strain. However, when a consortium is not cultured in a well-mixed environment the constituent strains passively compete for space as they grow and divide, complicating cell-cell signaling. Here, we explore the temporal dynamics of the spatial distribution of consortia co-cultured in microfluidic devices. To do this, we grew two different strains ofEscherichia coliin microfluidic devices with cell-trapping regions (traps) of several different designs. We found that the size and shape of the traps are critical determinants of spatiotemporal dynamics. In small traps, cells can easily signal one another but the relative proportion of each strain within the trap can fluctuate wildly. In large traps, the relative ratio of strains is stabilized, but intercellular signaling can be hindered by distances between cells. This presents a trade-off between the trap size and the effectiveness of intercellular signaling, which can be mitigated by controlling the initial seeding of cells in the large trap. These results show how synthetic microbial consortia behave in microfluidic traps and provide a method to help remedy the spatial heterogeneity inherent to different trap geometries.

scholarly journals Unexpected Co-infection with Different Strains of SARS-CoV-2 in Patients with COVID-19

2020 ◽  
Author(s):  
Hayder O. Hashim ◽  
Mudher K. Mohammed ◽  
Mazin J. Mousa ◽  
Hadeer H. Abdulameer ◽  
Alaa T.S. Alhassnawi ◽  
...  
Keyword(s):  
Biological Diversity ◽  
Viral Infections ◽  
Transmission Rate ◽  
Phylogenetic Analyses ◽  
Coding Region ◽  
Spike Glycoprotein ◽  
Single Strain ◽  
Different Strains ◽  
Multiple Strains

There is a rising global concern for the ongoing outbreak of SARS-CoV-2 due to its high transmission rate and unavailability of treatment. Through the binding of its spike glycoprotein with angiotensin type 2 (ACE2), SARS-CoV-2 can efficiently get in the cells of patients and start its pandemic cycle. Herein, the biological diversity of SARS-CoV-2 infection was assessed in Babylon province of Iraq by investigating the possible genetic variations of the spike glycoprotein. A specific coding region of 795 bp within the viral spike (S) gene was amplified from 19 patients who suffered from obvious symptoms of SARS-CoV-2 infection. Sequencing results identified fifteen novel nucleic acid variations with a variety of distributions within the investigated samples. The electropherograms of all the identified variations showed obvious co-infections with at least two different viral strains per sample. Within these co-infections, the majority of samples exhibited three nonsense single nucleotide polymorphism (SNP)s, p.301Cdel, p.380Ydel, and p.436del, which yielded three truncated SARS-CoV-2 spike glycoproteins of 301, 380, and 436 amino acids length, respectively. The network and phylogenetic analyses indicated that for all viral infections were derived from multi-ancestral origins. Results inferred from the specific clade-based tree entailed that some viral strains were derived from European G-clade sequences. In conclusion, our data demonstrated the absence of any single strain infection among all investigated viral samples in the studied area, which may entail a higher risk of SARS-CoV-2 in this country. Through the identified high frequency of truncated spike proteins, we suggest that defective SARS-CoV-2 may depend on helper strains having intact spikes in its infection. Alternatively, another putative ACE2-independent route of viral infection way also suggested. To the best of our knowledge, this is the first report to describe the co-infection of multiple strains of SARS-CoV-2 in patients with COVID-19.

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