Showing papers on "Growth medium published in 2021"

Effect of Selenium on the Growth and Lipid Accumulation of Yarrowia lipolytica Yeast.

Abstract: Nowadays, there is an increase attention on the effect of selenium (Se) on metabolic processes of microorganisms. Strains belonging to the genus of Yarrowia are of great biotechnological interest for various industries. In this study, we evaluated the effect of 10 mg/L of Se on the growth and lipid production of two Yarrowia lipolytica strains: the ACA DC 50109 and one more with increased oleagenicity, derived after ALE methodology (referred here as Y. lipolytica ALE_70). The presence of Se in the growth medium negatively affected both cell mass production and total lipid accumulation, for both Y. lipolytica strains. Fractionation of total lipids showed an inhibition on neutral lipid (NL) synthesis and consequently, an increase of polar lipids (glycolipids plus sphingolipids, and phospholipids) on the lipids of the Se-enriched ACA DC 50109 strain; however, the NL/polar ratio of the Se-enriched ALE_70 indicated that Se, apart from the inhibition of NL synthesis, provoked also the accumulation of polar lipids in this strain. In addition, the fatty acid (FA) composition was differently affected by Se. Se-enriched total lipids of the ALE_70 strain were enriched in linoleic acid (C18:2 n-6), which resulted in increase of the unsaturated index. On the other hand, Se-enriched lipids of the ACA DC 50109 strain were more saturated, as the percentage of palmitic (C16:0) and stearic (C18:0) acids increased in the total FAs. Moreover, it seems that Se influenced the activity or the expression of desaturases and elongase in both strains. Finally, the supplementation of growth medium with Se affected cell morphology, as well as the size and distribution of lipid droplets inside the yeast cells. According to our opinion, Se caused stress conditions and the consequence of that was the occurrence of metabolic disorders that affected cell mass, lipid content, and/or morphological structures. The results of the present study suggest that further research should be carried out to understand the background of the lipogenesis process in yeast cells cultured under stress conditions.

Excess Glucose Impedes the Proliferation of Skeletal Muscle Satellite Cells Under Adherent Culture Conditions

Abstract: Glucose is a major energy source consumed by proliferating mammalian cells. Therefore, in general, proliferating cells have the preference of high glucose contents in extracellular environment. Here, we showed that high glucose concentrations impede the proliferation of satellite cells, which are muscle-specific stem cells, under adherent culture conditions. We found that the proliferation activity of satellite cells was higher in glucose-free DMEM growth medium (low-glucose medium with a glucose concentration of 2 mM) than in standard glucose DMEM (high-glucose medium with a glucose concentration of 19 mM). Satellite cells cultured in the high-glucose medium showed a decreased population of reserve cells, identified by staining for Pax7 expression, suggesting that glucose concentration affects cell fate determination. In conclusion, glucose is a factor that decides the cell fate of skeletal muscle-specific stem cells. Due to this unique feature of satellite cells, hyperglycemia may negatively affect the regenerative capability of skeletal muscle myofibers and thus facilitate sarcopenia.

Utilization of bacteria in rotten Guava for production of bacterial cellulose from isolated and protein waste

Abstract: This work was done for optimizing the route to produce eco-friendly bacterial cellulose from bacteria in the rotten guava, and protein waste as cheap carbon/ nitrogen source in production medium. In this respect Komagataeibacter intermedius MO was isolated and identified. The protein-based waste (cheese whey) was evaluated as effective carbon/ nitrogen source in growth medium, in comparison with well-known medium (Seed medium). The role of cheese whey was studied individual and as substituting half of glucose or yeast of Seed medium. The X-ray diffraction, FT-IR spectra and TGA analysis were the techniques used in assessment together with production yield and strength properties. In comparison with seed medium the half substitution of yeast by cheese whey in seed medium exhibited enhancement of isolated Komagataeibacter intermedius MO in production of BC pellicles with high crystallinity, thermal stability and strength properties (tensile and elasticity). Moreover, despite its production yield was lower than that produced from seed medium, but it equivalent to BC production yield on using Hestrin- Schramm (HS) medium. This protein-waste suggested for modification of seed medium for economic production of BC for functional application.

TORC1 regulates the transcriptional response to glucose and developmental cycle via the Tap42-Sit4-Rrd1/2 pathway in Saccharomyces cerevisiae.

Abstract: Target of Rapamycin Complex 1 (TORC1) is a highly conserved eukaryotic protein complex that couples the presence of growth factors and nutrients in the environment with cellular proliferation. TORC1 is primarily implicated in linking amino acid levels with cellular growth in yeast and mammals. Although glucose deprivation has been shown to cause TORC1 inactivation in yeast, the precise role of TORC1 in glucose signaling and the underlying mechanisms remain unclear. We demonstrate that the presence of glucose in the growth medium is both necessary and sufficient for TORC1 activation. TORC1 activity increases upon addition of glucose to yeast cells growing in a non-fermentable carbon source. Conversely, shifting yeast cells from glucose to a non-fermentable carbon source reduces TORC1 activity. Analysis of transcriptomic data revealed that glucose and TORC1 co-regulate about 27% (1668/6004) of yeast genes. We demonstrate that TORC1 orchestrates the expression of glucose-responsive genes mainly via the Tap42-Sit4-Rrd1/2 pathway. To confirm TORC1’s function in glucose signaling, we tested its role in spore germination, a glucose-dependent developmental state transition in yeast. TORC1 regulates the glucose-responsive genes during spore germination and inhibition of TORC1 blocks spore germination. Our studies indicate that a regulatory loop that involves activation of TORC1 by glucose and regulation of glucose-responsive genes by TORC1, mediates nutritional control of growth and development in yeast.

Exogenous carbon source supplementation counteracts root and hypocotyl growth limitations under increased cotyledon shading, with glucose and sucrose differentially modulating growth curves.

Abstract: Plant growth is continuously modulated by endogenous and exogenous stimuli. By no means the only, but well described, signaling molecules produced in plants and distributed through the plant body to orchestrate efficient growth are photosynthates. Light is a potent exogenous stimulus that determines, first, the rate of photosynthesis, but also the rate of plant growth. Root meristem activity is reduced with direct illumination but enhanced with increased sugar levels. With reduced cotyledon illumination, the seedling increases hypocotyl elongation until adequate light exposure is again provided. If endogenous carbon sources are limited, this leads to a temporary inhibition of root growth. Experimental growth conditions include exogenous supplementation of sucrose or glucose in addition to culturing seedlings under light exposure in Petri dishes. We compared total root length and hypocotyl elongation of Arabidopsis thaliana wild type Col-0 in response to illumination status and carbon source in the growth medium. Overall, sucrose supplementation promoted hypocotyl and root length to a greater extent than glucose supplementation. Glucose promoted root length compared to non-supplemented seedlings especially when cotyledon illumination was greatly reduced.

Features of iron accumulation at high concentration in pulcherrimin-producing Metschnikowia yeast biomass.

Abstract: In previous studies it was found that the antimicrobial properties of pulcherrimin-producing Metschnikowia species are related to the formation of a red pigment—pulcherrimin and sequestration of free iron from their growth medium. For strains of Metschnikowia pulcherrima, M. sinensis, M. shaxiensis, and M. fructicola, at a high, ≈80 mg/kg, elemental Fe concentration in agar growth media we observed the essentially different (metal luster, non-glossy rust like, and colored) yeast biomass coatings. For the studied strains the optical and scanning electron microscopies showed the increased formation of chlamydospores that accumulate a red pigment—insoluble pulcherrimin rich in iron. The chlamydospore formation and decay depended on the iron concentration. In this study pulcherrimin in biomass of the selected Metschnikowia strains was detected by Mossbauer spectroscopy. At ≈80 mg/kg elemental Fe concentration the Mossbauer spectra of biomass of the studied strains were almost identical to these of purified pulcherrimin. Iron in pulcherrimin reached ≈1% of biomass by weight which is very high in comparison with elemental Fe percentage in growth medium and is not necessary for yeast growth. The pulcherrimin in biomass was also observed by Mossbauer spectroscopy at lower, ≈5 mg/kg, elemental Fe concentration. Through chemical binding of iron pulcherrimin sequestrates the soluble Fe in the growth media. However, at high Fe concentrations, the chemical and biochemical processes lead to the pulcherrimin accumulation in biomass chlamydospores. When soluble iron is sequestrated or removed from the growth media in this way, it becomes inaccessible for other microorganisms.

Diversity and characteristics of culturable endophytic bacteria from Passiflora edulis seeds.

Abstract: Defense compounds generally inhibit microbial colonization of plants. In this study, we examined the presence of endophytes in Passiflora edulis seeds that accumulate resveratrol and piceatannol at extremely high levels as defense compounds. Interestingly, although no microbial colonies appeared on an agar growth medium from the cut or homogenized seeds, colonies were generated from cut seedlings derived from the seeds. A total of 19 bacterial strains were isolated, of which 15 were classified as Gram-positive. As we hypothesized that extremely high levels of piceatannol in the seeds would inhibit the growth of endophytes cultured directly from the seeds, we examined the antimicrobial activity of this compound against the isolated bacteria. Piceatannol exerted bacteriostatic rather than bactericidal effects on most of the bacteria tested. These results suggest that the bacteria remain static in the seeds due to the presence of piceatannol and are transmitted to the seedlings during the germination process, enabling colonies to be established from the seedlings on the agar medium. We also investigated the biocatalytic activity of the isolated bacteria toward resveratrol and piceatannol. One bacterium, Brevibacterium sp. PE28-2, converted resveratrol and piceatannol to their respective derivatives. This strain is the first endophyte shown to exhibit such activity.

Genetically Engineered Oleaginous Yeast Lipomyces starkeyi for Sesquiterpene α-Zingiberene Production

Abstract: Oleaginous yeast, such as Lipomyces starkeyi, are logical organisms for production of higher energy density molecules like lipids and terpenes. We demonstrate that transgenic L. starkeyi strains expressing an α-zingiberene synthase gene from lemon basil or Hall's panicgrass can produce up to 17 mg/L α-zingiberene in yeast extract peptone dextrose (YPD) medium containing 4% glucose. The transgenic strain was further examined in 8% glucose media with C/N ratios of 20 or 100, and YPD. YPD medium resulted in 59 mg/L α-zingiberene accumulation. Overexpression of selected genes from the mevalonate pathway achieved 145% improvement in α-zingiberene synthesis. Optimization of the growth medium for α-zingiberene production led to 15% higher titer than YPD medium. The final transgenic strain produced 700 mg/L α-zingiberene in fed-batch bioreactor culture. This study opens a new synthetic route to produce α-zingiberene or other terpenoids in L. starkeyi and establishes this yeast as a platform for jet fuel biosynthesis.

A buffered media system for yeast batch culture growth

Abstract: Fungi are premier hosts for the high-yield secretion of proteins for biomedical and industrial applications. The stability and activity of these secreted proteins is often dependent on the culture pH. As yeast acidifies the commonly used synthetic complete drop-out (SD) media that contains ammonium sulfate, the pH of the media needs to be buffered in order to maintain a desired extracellular pH during biomass production. At the same time, many buffering agents affect growth at the concentrations needed to support a stable pH. Although the standard for biotechnological research and development is shaken batch cultures or microtiter plate cultures that cannot be easily automatically pH-adjusted during growth, there is no comparative study that evaluates the buffering capacity and growth effects of different media types across pH-values in order to develop a pH-stable batch culture system. We systematically test the buffering capacity and growth effects of a citrate-phosphate buffer (CPB) from acidic to neutral pH across different media types. These media types differ in their nitrogen source (ammonium sulfate, urea or both). We find that the widely used synthetic drop-out media that uses ammonium sulfate as nitrogen source can only be effectively buffered at buffer concentrations that also affect growth. At lower concentrations, yeast biomass production still acidifies the media. When replacing the ammonium sulfate with urea, the media alkalizes. We then develop a medium combining ammonium sulfate and urea which can be buffered at low CPB concentrations that do not affect growth. In addition, we show that a buffer based on Tris/HCl is not effective in maintaining any of our media types at neutral pH even at relatively high concentrations. Here we show that the buffering of yeast batch cultures is not straight-forward and addition of a buffering agent to set a desired starting pH does not guarantee pH-maintenance during growth. In response, we present a buffered media system based on an ammonium sulfate/urea medium that enables relatively stable pH-maintenance across a wide pH-range without affecting growth. This buffering system is useful for protein-secretion-screenings, antifungal activity assays, as well as for other pH-dependent basic biology or biotechnology projects.

Growth Analysis of Single Cell Protein (PST) Bacteria Bacillus cereus using Different Media

Abstract: The Media is a material consisting of a mixture of nutrients used by microorganisms to grow and breed. Molasses and liquid waste know one of the alternative media which has the least inexpensive carbon source and is easily obtained from the waste food industry that is rich in nutrients and minerals, so it has the potential for bacterial growth of Bacillus cereus. The consetration of molasses used for growth medium is 1%; 1.5%; and 2% while liquid waste knows 8%, 10%, and 12%. Cell growth is measured by the method of Spectrophotometry, total plate count (TPC) and biomass while the incubation period of cell growth is measured every 0, 6, 12, 18, and 24 hours. The results showed from the molasses + skim milk and the tofu liquid waste + skim milk, the best medium of bacterial cell growth of B. cereus is a liquid waste know isolates K 12%. While the best growth concentrations molasses Medium bacterial B.cereus was N2% and K2%.

Escherichia coli amino acid auxotrophic expression host strains for investigating protein structure–function relationships

Abstract: A set of C43(DE3) and BL21(DE3) Escherichia coli host strains that are auxotrophic for various amino acids is briefly reviewed. These strains require the addition of a defined set of one or more amino acids in the growth medium, and have been specifically designed for overproduction of membrane or water-soluble proteins selectively labelled with stable isotopes, such as 2H, 13C and 15N. The strains described here are available for use and have been deposited into public strain banks. Although they cannot fully eliminate the possibility of isotope dilution and mixing, metabolic scrambling of the different amino acid types can be minimized through a careful consideration of the bacterial metabolic pathways. The use of a suitable auxotrophic expression host strain with an appropriately isotopically labelled growth medium ensures high levels of isotope labelling efficiency as well as selectivity for providing deeper insight into protein structure-function relationships.

Identification of Bacteria Associated with Post-Operative Wounds of Patients with the Use of Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry Approach.

Abstract: The bacterial infection of post-operative wounds is a common health problem. Therefore, it is important to investigate fast and accurate methods of identifying bacteria in clinical samples. The aim of the study was to analyse the use of the MALDI-TOF MS technique to identify microorganism wounds that are difficult to heal. The most common bacteria are Escherichia coli, Staphylococcus spp., and Enterococcus spp. We also demonstrate the effect of culture conditions, such as the used growth medium (solid: Brain Heart Infusion Agar, Mueller Hilton Agar, Glucose Bromocresol Purple Agar, and Vancomycin Resistance Enterococci Agar Base and liquid: Tryptic Soy Broth and BACTEC Lytic/10 Anaerobic/F), the incubation time (4, 6, and 24h), and the method of the preparation of bacterial protein extracts (the standard method based on the Bruker guideline, the Sepsityper method) to identify factors and the quality of the obtained mass spectra. By comparing the protein profiles of bacteria from patients not treated with antibiotics to those treated with antibiotics based on the presence/absence of specific signals and using the UniProt platform, it was possible to predict the probable mechanism of the action of the antibiotic used and the mechanism of drug resistance.

Fluorescence Detection of Increased Reactive Oxygen Species Levels in Saccharomyces cerevisiae at the Diauxic Shift.

Abstract: The budding yeast Saccharomyces cerevisiae is a facultative organism that is able to utilize both anaerobic and aerobic metabolism, depending on the composition of carbon source in the growth medium. When glucose is abundant, yeast catabolizes it to ethanol and other by-products by anaerobic fermentation through the glycolysis pathway. Following glucose exhaustion, cells switch to oxygenic respiration (a.k.a. "diauxic shift"), which allows catabolizing ethanol and the other carbon compounds via the TCA cycle and oxidative phosphorylation in the mitochondria. The diauxic shift is accompanied by elevated reactive oxygen species (ROS) levels and is characterized by activation of ROS defense mechanisms. Traditional measurement of the diauxic shift is done through measuring optical density of cultures grown in a batch at intermediate time points and generating a typical growth curve or by estimating the reduction of glucose and accumulation of ethanol in growth media over time. In this manuscript, we describe a method for determining changes in ROS levels upon yeast growth, using carboxy-H(2)-dichloro-dihydrofluorescein diacetate (carboxy-H(2)-DCFDA). H2-DCFDA is a widely used fluorescent dye for measuring intracellular ROS levels. H2-DCFDA enables a direct measurement of ROS in yeast cells at intermediate time points. The outcome of H2-DCFDA fluorescent readout measurements correlates with the growth curve information, hence providing a clear understanding of the diauxic shift.

Physiological and biochemical traits, antioxidant compounds and some physico-chemical factors of Spirulina platensis cultivation as influenced by Moringa oleifera leaves extract culture medium enriched with sodium bicarbonate and kanwa

Abstract: The prospects for using Moringa oleifera leaves extract (MLE) supplemented with different concentrations of kanwa or sodium bicarbonate (NaHCO3) as a low-cost alternative growth medium of Spirulina platensis were evaluated in a small-scale outdoor cultivation system. The present study was aimed to evaluate the potential of MLE growth medium enriched with different concentrations (4 or 8 g L-1) of kanwa and NaHCO3 on growth, chlorophyll content, biochemical characteristics, antioxidant compounds and some physico-chemical factors. Jourdan’s standard medium was taken as control. The results showed that the growth parameters such as cell population, biomass dry weight, cell productivity and specific growth rate were positively affected in MLE cultivation medium enriched with kanwa or NaHCO3 at different concentration levels. The addition of urea, kanwa or NaHCO3 in MLE cultivation medium at different concentration levels increased significantly (p< 0.05) the protein content, the peroxidase and polyphenol oxidase activity, the conductivity, pH, total dissolved solids and salinity from 20 to 25 days of cultivation whereas a decrease in carbohydrate and phenol content was recorded during all the period of the experimentation. The highest values of growth parameters were notably in MLE medium supplemented with urea and kanwa at 8 g L-1. The MLE medium enriched with urea and kanwa at 8 g L-1 was shown to be an appropriate growth medium that can be used as a low-cost alternative growth medium for commercial cultivation of S. platensis. Key words: Antioxidant compounds, biochemical traits, growth, Moringa oleifera leaves extract, physico-chemical factors, Spirulina platensis.

Efficiency of arsenic remediation from growth medium through Bacillus licheniformis modulated by phosphate (PO4)3- and nitrate (NO3)- enrichment.

Abstract: Bacillus licheniformis DAS-1 and DAS-2 were found as potent tool for removal/uptake of arsenic [As(V) and As(III)] and reduction [(As(V) to As(III)] of arsenic from the liquid growth medium in our previous studies. Present work gives light on modulation of arsenic remediation (in terms of uptake and reduction) by two selected essential soil nutrients, phosphate (PO4)3− and nitrate (NO3)−. PO43− has structural analogy with arsenate [AsO43−/As(V)] that compete with cell uptake of As(V). It was found that enrichment of 0.75 mM of PO43− had significantly moderated the As(V) toxicity in liquid broth culture by retarding As(V) uptake. Lowering level of PO43− can lead to increase in As(V) removal from medium and vice versa. NO3− has strong oxidant properties which controls As(III) oxidation into As(V) in medium that resulted less toxicity favouring growth of bacteria and also more uptake via phosphate transporters. Hence, accelerated As(III) uptake has shown on enrichment of 0.5 mM of NO3− in medium. All the results of work give evidence that appropriate enrichment of PO43− and NO3− into liquid growth medium, can significantly contribute in alteration of efficiency for arsenic removal/uptake and reduction by bacteria from the medium.

Determining Minimum Inhibitory Concentrations in Liquid Cultures or on Solid Medium

Abstract: Antimicrobial susceptibility testing is the mainstay of tuberculosis drug development programs. In this chapter, we describe methods for determination of the minimum inhibitory concentration of compounds against Mycobacterium tuberculosis growing in liquid media as a function of carbon source, detergent, and environmental stress imposed by acidic pH as well as reactive nitrogen intermediates. Methods for determining the effect of bovine serum albumin in the growth medium on antimicrobial susceptibility are also described. Finally, we provide a method for antimicrobial susceptibility testing on agar medium.

Corynebacterium diphtheriae Proteome Adaptation to Cell Culture Medium and Serum

Abstract: Host-pathogen interactions are often studied in vitro using primary or immortal cell lines. This set-up avoids ethical problems of animal testing and has the additional advantage of lower costs. However, the influence of cell culture media on bacterial growth and metabolism is not considered or investigated in most cases. To address this question growth and proteome adaptation of Corynebacterium diphtheriae strain ISS3319 were investigated in this study. Bacteria were cultured in standard growth medium, cell culture medium, and fetal calf serum. Mass spectrometric analyses and label-free protein quantification hint at an increased bacterial pathogenicity when grown in cell culture medium as well as an influence of the growth medium on the cell envelope.

Changes in Energy Status of Saccharomyces cerevisiae Cells during Dehydration and Rehydration.

Abstract: Anhydrobiosis is the state of life when cells are exposed to waterless conditions and gradually cease their metabolism. In this study, we determined the sequence of events in Saccharomyces cerevisiae energy metabolism during processes of dehydration and rehydration. The intensities of respiration and acidification of the medium, the amounts of phenyldicarbaundecaborane (PCB−) bound to yeast membranes, and the capabilities of cells to accumulate K+ were assayed using an electrochemical monitoring system, and the intracellular content of ATP was measured using a bioluminescence assay. Mesophilic, semi-resistant to desiccation S. cerevisiae strain 14 and thermotolerant, very resistant to desiccation S. cerevisiae strain 77 cells were compared. After 22 h of drying, it was possible to restore the respiration activity of very resistant to desiccation strain 77 cells, especially when glucose was available. PCB− binding also indicated considerably higher metabolic activity of dehydrated S. cerevisiae strain 77 cells. Electrochemical K+ content and medium acidification assays indicated that permeabilization of the plasma membrane in cells of both strains started almost simultaneously, after 8–10 h of desiccation, but semi-resistant strain 14 cells maintained the K+ gradient for longer and more strongly acidified the medium. For both cells, the fast rehydration in water was less efficient compared to reactivation in the growth medium, indicating the need for nutrients for the recovery. Higher viability of strain 77 cells after rehydration could be due to the higher stability of their mitochondria.

KAv-1 is Better Suited to Chick Fibroblast Culture than DMEM or 199 Media

Abstract: Cultured cells are a useful resource for poultry scientists, since these cells allow scientists to evaluate biological responses to conditions such as infectious diseases in vitro while mimicking the whole-body response in birds. However avian cell culture requires an optimized basal medium, and there are currently relatively few options for this basal medium (medium 199 and KAv-1). This means that there is still room for the development of an optimal basal medium for avian cell culture. Here we compare KAv-1 medium, Dulbecco's modified Eagle medium (DMEM) and medium 199 during the culture of chick fibroblasts and determine that KAv-1 remains the optimal medium for these assays. Our results show that DNA damage is reduced in fibroblasts cultured in the KAv-1 medium, when compared to both DMEM and Medium 199 and that these cells also display improved growth dynamics in KAv-1 medium when compared to both DMEM and medium 199. To the best of our knowledge, this is the first study to describe a comparative analysis of culture media for avian cells, which would provide useful information for poultry scientists.

Pigeonpea (Cajanus cajan L.) and Cowpea (Vigna unguiculata L.) Water as Alternative Growth Medium for Escherichia coli and Staphylococcus aureus in Laboratory with Minimum Infrastructure

Abstract: The availability of non-synthetic media from natural ingredients is needed to answer the needs in laboratories where the price of nutrient media is quite expensive and there are limited supplies of material ware houses. Cowpea (Vigna unguiculata L.) and pigeonpea (Cajanus cajan L.) are the local foods of people of NTT (East Nusa Tenggara) which have a high enough nutritional content which has the potential to be developed into cheap, easy and simple non-synthetic media in making. The purpose of this study was to determine whether the agar media contained nutrient from cowpea and pigeonpea water can be used as a alternative for nutrient agar for the growth of Escherchia coli and Staphylococcus aureus bacteria. This research is a true experiment with posttest-only control design. The growth rate of S. aureus bacteria on pigeonpea medium, cowpea medium, nutrient agar medium, were 164 CFU/mL (SD=3,13), 161 CFU/mL (SD=3,02) and 164 CFU/mL (SD=3,21), respectively. The average growth of E. coli on cowpea medium, pigeonpea medium, and nutrient agar control medium were 163 CFU/mL (SD=2,79), 167 CFU/mL (SD-2,63) and 164 CFU/mL (SD=2,75) respectively. Test results ANOVA between pigeonpea medium, cowpea medium and nutrient medium in order to obtain p value = 0.145 (p> 0.05) for the growth of E. coli bacteria and p value = 0.393 (p> 0.05) for growth S. aureus. It was concluded that there was no difference between the number of bacterial colonies of E. coli and S. aureus on three medium. The pigeonpea medium and cowpea can be used to grow and alternative nutrient agar in order to grow bacteria E. coli and S. aureus.

Production of fatty acid esters using a yeast culture

Abstract: The subject invention provides improved methods for producing fatty acid esters using yeast not previously known to produce fatty acid esters. In particular, Meyerozyma spp. can be cultivated under specially-tailored conditions such that the yeast produces a variety of fatty acid esters. A yeast culture and fermentation compositions are also provided, comprising yeast cells, liquid growth medium, and a high concentration of growth by-products, such as fatty acid esters.

Serum-free mycoplasma growth medium

Abstract: The present invention provides a serum-free cell culture medium formulation that supports the in vitro cultivation of Mycoplasma species, especially of M. pneumoniae, and methods for cultivating Mycoplasma species in vitro, using these media. The media comprise a basal medium comprising at least one carbon source, vitamins, nucleotides, amino acids, and lipids including cholesterol, phospholipids and sphingolipids, and optionally palmitic acid and/or oleic acid. The invention further provides a use of phospholipids and sphingolipids to support growth of a Mycoplasma spp., preferably M. pneumoniae.

Method for producing mature myotube cells from skeletal muscle stem cells

Abstract: A method for producing mature myotube cells from skeletal muscle stem cells, said method being characterized by comprising: (1) a step of seeding skeletal muscle stem cells in a cell culture container and culturing the cells using a growth medium; (2) a step of exchanging the medium by a differentiation medium and continuing the culture until some of the cells show a spindle shape; and (3) a step of overlaying a gel, which contains an extracellular matrix component, on the cells and performing the culture using the differentiation medium.

Glucose Starvation, Magnesium Ion Starvation, and Bile Stress Assays.

Abstract: Salmonella enterica serovar Enteritidis (S. Enteritidis) is a leading causative pathogen for food-borne gastroenteritis. During its course of infection, it confronts myriads of physiological barriers inside the host, such as nutrient deprivation, low micronutrient availability, and toxicity from bile salts, to promote bacterial survival and infection inside the host. The ability of the pathogen to overcome these stressful conditions determines the degree of virulence in the host. Therefore, assessment of the survival of a pathogen during different stress conditions, like glucose starvation, magnesium starvation, and bile stress, are important parameters to assess the virulence of the pathogen. Here, we describe protocols for estimating the survival of the pathogen during the above-mentioned stress conditions. We culture S. Enteritidis in an appropriate growth medium to a required O.D.600 and treat it with glucose starvation (M9 minimal culture medium containing 0.03% glucose), magnesium starvation (M9 minimal culture medium containing 20 µM MgSO4), and bile stress (bacterial cells treated with 15% bile salts in Luria Bertani (LB) culture medium) conditions. The number of surviving bacteria is obtained after the treatment by calculating the colony-forming units (CFU) of the surviving pathogen obtained on LB agar plates at relevant time intervals. The experiments are performed in biological replicates, and statistical analysis is performed to validate the experimental findings. The methodology of these stress response assays is simple and can be adapted to study the pathogenesis and stress response in other relevant and culturable enteric pathogens.

Optimization of Culture Conditions for Mycelial Growth and Sporulation of Myrothecium roridum

Abstract: Culture and nutrition conditions of Myrothecium roridum Tode were optimized by conducting a series of interlined experiments on a growth medium, temperature, pH, and photoperiod. In contrast, relation of culture age with virulence was measured by fungal development on young leaves of bitter gourd. The physiological response was measured on colony radial growth and spore production. Among the six test growth media, i.e., nutrient agar (NA), potato dextrose agar (PDA), Czapek-Dox agar (CDA), glucose agar (GA), malt extract agar (MEA), and bitter gourd agar (BGA), the highest radial growth (77 mm) and the highest number of spores (239 × 10 6 spores/ml) were observed on PDA. Incubation temperature was evaluated between a range of 15-40 °C, and the highest colony growth (87 mm) was observed at 30 °C, whereas the highest spore production (315 × 10 6 spores/ml) was at 35 °C. Different pH levels, i.e., 5, 5.5, 6, 6.5, 7, and 7.5, were optimized, and the highest colony growth (87 mm) and spore production (504 × 10 6 spores/ml) was recorded at pH 5.0. Impact of photoperiod was studied, and the highest mycelial growth (88 mm) and maximum spore production (524 × 10 6 spores/ml) was observed at 16/8 h alternate light and dark period. It was concluded that the optimum conditions for mycelia growth and spore production was pH 5.0-6.0 and at 30 ± 2 °C in PDA with 16/8 h alternate light and dark photoperiod.