Determination of Ideal Culture Media for Optimal Mycelia Growth of Rice Blast Pathogen (MagnaportheOryzae)

Several strains of Penicillium are used for the production of mold-ripened cheeses, and some of them are able to produce mycotoxins. The aims of the research were the determination of roquefortine C and PR toxin in domestic and imported blue cheeses, the identification of the penicillia used as starter, and the investigation of their capacity for producing toxins in culture media. Roquefortine C was always found in the cheeses at levels ranging from 0.05 to 1.47 mg/kg, whereas the PR toxin was never found. The identification of the fungal strains present in the domestic cheeses included Penicillium glabrum, Penicillium roqueforti, and Penicillium cyclopium in the Gorgonzola “dolce” and Penicillium roqueforti in the Gorgonzola “naturale”; in one case, the presence of Penicillium crustosum was observed. The strains isolated from the foreign cheeses belonged to P. roqueforti. The strains were able to produce between 0.18 and 8.44 mg/liter of roquefortine in yeast extract sucrose medium and between 0.06 and 3.08 mg/liter and less than 0.05 mg/liter when inoculated in milk at 20°C for 14 days and 4°C for 24 days, respectively. Linear relations between production of roquefortine in culture media and cheeses did not emerge. PR toxin ranged from less than 0.05 to 60.30 mg/liter in yeast extract sucrose medium and was produced in milk at 20°C from only one strain. The low levels and the relatively low toxicity of roquefortine make the consumption of blue cheese safe for the consumer.

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Antioxidant or Apoptosis Inhibitor Supplementation in Culture Media Improves Post-Thaw Recovery of Murine Spermatogonial Stem Cells

Antioxidants ◽

10.3390/antiox10050754 ◽

2021 ◽

Vol 10 (5) ◽

pp. 754

Author(s):

Sang-Eun Jung ◽

Hui-Jo Oh ◽

Jin-Seop Ahn ◽

Yong-Hee Kim ◽

Bang-Jin Kim ◽

...

Keyword(s):

Stem Cells ◽

Functional Activity ◽

Culture Media ◽

Quantitative Polymerase Chain Reaction ◽

Spermatogonial Stem Cells ◽

Ros Generation ◽

Apoptosis Assay ◽

Polymerase Chain ◽

Apoptosis Inhibitor

We postulated that supplementation of antioxidant or apoptosis inhibitor in post-thaw culture media of spermatogonial stem cells (SSCs) alleviates reactive oxygen species (ROS) generation and apoptosis. Our aim was to develop an effective culture media for improving post-thaw recovery of SSCs. To determine the efficacy of supplementation with hypotaurine (HTU), α-tocopherol (α-TCP), and Z-DEVD-FMK (ZDF), we assessed the relative proliferation rate and SSC functional activity and performed a ROS generation assay, apoptosis assay, and western blotting for determination of the Bax/Bcl-xL ratio, as well as immunocytochemistry and real-time quantitative polymerase chain reaction (RT-qPCR) for SSC characterization. The relative proliferation rates with HTU 400 μM (133.7 ± 3.2%), α-TCP 400 μM (158.9 ± 3.6%), and ZDF 200 μM (133.1 ± 7.6%) supplementation were higher than that in the DMSO control (100 ± 3.6%). ROS generation was reduced with α-TCP 400 μM (0.8-fold) supplementation in comparison with the control (1.0-fold). Early apoptosis and Bax/Bcl-xL were lower with α-TCP 400 μM (2.4 ± 0.4% and 0.5-fold) and ZDF 200 μM (1.8 ± 0.4% and 0.3-fold) supplementation in comparison with the control (5.3 ± 1.4% and 1.0-fold) with normal characterization and functional activity. Supplementation of post-thaw culture media with α-TCP 400 μM and ZDF 200 μM improved post-thaw recovery of frozen SSCs via protection from ROS generation and apoptosis after cryo-thawing.

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Application of Flow Cytometry to Segregated Kinetic Modeling Based on the Physiological States of Microorganisms

Applied and Environmental Microbiology ◽

10.1128/aem.00171-07 ◽

2007 ◽

Vol 73 (12) ◽

pp. 3993-4000 ◽

Cited By ~ 36

Author(s):

Covadonga Quirï¿½s ◽

Mï¿½nica Herrero ◽

Luis A. Garcï¿½a ◽

Mario Dï¿½az

Keyword(s):

Flow Cytometry ◽

Culture Media ◽

Glucose Consumption ◽

Viable Cell ◽

Counting Method ◽

Batch Cultures ◽

Viable Cells ◽

The Status ◽

Standard Culture

ABSTRACT Flow cytometry (FC) has been introduced to characterize and to assess the physiological states of microorganisms in conjunction with the classical plate-counting method. To show the applicability of the technique, in particular for the development of kinetic models, pure culture fermentation experiments were followed over time, using both prokaryotic (Lactobacillus hilgardii) and eukaryotic (Saccharomyces cerevisiae) microorganisms growing in standard culture media (MRS and YPD). The differences observed between the active and viable cells determined by FC and CFU, respectively, allowed us to determine that a large number of cells were in a viable but nonculturable (VBNC) state, which resulted in a subpopulation much larger than the damaged-cell (double-stained) subpopulation. Finally, the determination of the evolution of viable, the VBNC, and the dead cells allowed us to develop a segregated kinetic model to describe the yeast and the bacteria population dynamics and glucose consumption in batch cultures. This model, more complete than that which is traditionally used, based only on viable cell measurements, describes better the behavior and the functionality of the cultures, giving a deeper knowledge in real time about the status and the course of the bioprocesses.

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Production of a bacteriocin active on lactate-fermenting clostridia byLactococcus lactissubsp.lactisimmobilized in coated alginate beads

Journal of Dairy Research ◽

10.1017/s002202990002793x ◽

1993 ◽

Vol 60 (4) ◽

pp. 581-591 ◽

Cited By ~ 21

Author(s):

Nicla Zezza ◽

Gabriella Pasini ◽

Angiolella Lombardi ◽

Annick Mercenier ◽

Paolo Spettoli ◽

...

Keyword(s):

Immobilized Cells ◽

Culture Media ◽

Surrounding Medium ◽

Free Cell ◽

Alginate Beads ◽

Cell System ◽

Indicator Strain ◽

Lactobacillus Delbrueckii ◽

Gel Beads

SummaryWe report the isolation and immobilization of a nisinogenic strain (NZ1) ofLactococcus lactissubsp.lactis, active on gas-forming lactate-fermenting clostridia responsible for late blowing of Asiago and Montasio cheeses. The bacteriocin (nisin) produced by strain NZ1 is pronase-sensitive and is released in culture media during the growth phase. Using the sensitive indicator strainLactobacillus delbrueckiisubsp.bulgaricusNCDO 1489, a rapid microtitre plate based assay was developed for quantitative determination of the bacteriocin produced by NZ1 cells, either free or immobilized in gel beads. Scanning electron microscopy of cells immobilized in calcium alginate coated beads and viable counts of the surrounding medium showed that no cell leakage occurred during a 24 h assay. The bacteriocin released from immobilized cells reached, after 5 and 24 h, concentrations comparable to that of the free cell system after 3–4 h incubation in culture media.

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Determination of the biodegradability of chitosan utilizing the most probable number technique

Acta Scientiarum Biological Sciences ◽

10.4025/actascibiolsci.v42i1.52965 ◽

2020 ◽

Vol 42 ◽

pp. e52965

Author(s):

Wender Cardoso Silva ◽

Ilva de Fátima Souza ◽

Vivian Machado Benassi ◽

Juan Pedro Bretas Roa ◽

Paulo Henrique Graziotti ◽

...

Keyword(s):

Soil Microorganisms ◽

Culture Medium ◽

Culture Media ◽

Soil Samples ◽

Most Probable Number ◽

Probable Number ◽

Strong Indicator ◽

Specific Culture ◽

Chitosan Biopolymer

The present work aimed to evaluate the degradability of the chitosan polymer by soil microorganisms. This evaluation was accomplished using the Most Probable Number (MPN) method by plating in drops so that soil microorganisms capable of degrading the polymeric material could be quantified. Soil samples diluted in three specific culture media for each type of microorganism were plated – bacteria, fungi and actinobacteria – and they were maintained at 28°C for seven days to determine the growth rate of fungi and actinobacteria, and for 48 hours for the development of bacteria. Significant differences in the MPN of actinobacteria relative to the other groups analyzed were observed. Thus, the method used was effective for determining the degradability of the chitosan biopolymer when observing the development of microorganisms subjected to the replacement of the carbon source by the addition of 2% w v-1 of the chitosan biopolymer to the culture medium. The formation of clear regions around the microbial colonies was a strong indicator of biodegradation.

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Determination of Dissolved CO2 Concentration in Culture Media: Evaluation of pH Value and Mathematical Data

Processes ◽

10.3390/pr8111373 ◽

2020 ◽

Vol 8 (11) ◽

pp. 1373

Author(s):

Amir Izzuddin Adnan ◽

Mei Yin Ong ◽

Saifuddin Nomanbhay ◽

Pau Loke Show

Keyword(s):

Carbon Dioxide ◽

Ph Value ◽

Culture Media ◽

Co2 Concentration ◽

Co2 Solubility ◽

Greenhouse Gasses ◽

Dipotassium Phosphate ◽

The Difference ◽

Carbon Dioxide Co2

Carbon dioxide is the most influential gas in greenhouse gasses and its amount in the atmosphere reached 412 µmol/mol in August 2020, which increased rapidly, by 48%, from preindustrial levels. A brand-new chemical industry, namely organic chemistry and catalysis science, must be developed with carbon dioxide (CO2) as the source of carbon. Nowadays, many techniques are available for controlling and removing carbon dioxide in different chemical processes. Since the utilization of CO2 as feedstock for a chemical commodity is of relevance today, this study will focus on how to increase CO2 solubility in culture media used for growing microbes. In this work, the CO2 solubility in a different medium was investigated. Sodium hydroxide (NaOH) and monoethanolamine (MEA) were added to the culture media (3.0 g/L dipotassium phosphate (K2HPO4), 0.2 g/L magnesium chloride (MgCl2), 0.2 g/L calcium chloride (CaCl2), and 1.0 g/L sodium chloride (NaCl)) for growing microbes in order to observe the difference in CO2 solubility. Factors of temperature and pressure were also studied. The determination of CO2 concentration in the solution was measured by gas analyzer. The result obtained from optimization revealed a maximum CO2 concentration of 19.029 mol/L in the culture media with MEA, at a pressure of 136.728 kPa, operating at 20.483 °C.

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