• Journal of Mushroom
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• v.19 no.3
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• pp.126-133
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• 2021

In this study, we investigated the effect of solid culture medium on the production of cordycepin in Cordyceps militaris. The regression equation was expressed as follows: Y₁ = 755.3-58.6625X₁+4.79432E-14X₂-46.6625X₃-5.66269E-14X₁X₂-0.025X₁X₃+1.62475E-14X₂X₃-160.6625X₁²+0.0125X₂²-206.9625X₃², where, Y represents the value of cordycepin content (㎍/g), X₁ corresponds to the weight of M. alternatus in solid culture medium (g/bottle), X₂ to the water content of the solid culture medium (%), and X₃ to the culture period (day). The solid culture medium was optimized using the response surface methodology, and the optimal medium composition was as follows: the weight of M. alternatus in solid culture medium and water content were 16.2% and 100.7% (20.14 mL water/20 g solid culture medium), respectively, with a culture period of 39 days. Under these conditions, the cordycepin content of the fruiting bodies reached 150.0 ㎍/g (actual value). The supplementation of M. alternatus in solid culture for improved cordycepin content of C. militaris seems to be a promising alternative to wild and solid cultivation.

• Journal of The Korean Society of Clinical Toxicology
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• v.20 no.2
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• pp.75-81
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• 2022

Purpose: This study sought to compare the characteristics of patients with pathogen-positive and negative cultures, and to investigate factors predicting pathogen-positive culture results in patients of acute poisoning with suspected aspiration. Methods: Consecutive patients with acute poisoning admitted to an intensive care unit between January 2016 and December 2018 were retrospectively studied. Respiratory specimens were collected from the enrolled patients at the time of the suspected aspiration. We compared the characteristics of patients with pathogen-positive and negative culture results and analyzed the causative pathogens. Results: Among the 526 patients, 325 showed no clinical features that could be attributed to aspiration, and 201 patients had clinical features suggestive of aspiration. Of these, 113 patients had pathogen-positive culture, 61 were negative, and the specimens of 27 patients contained poor-quality sputum. In univariate analysis, patients with a positive culture showed a longer time to culture from ingestion (p=0.01), faster heart rate (p=0.01), and higher partial pressure of arterial oxygen to the fraction of inspired oxygen (PaO₂/FiO₂) (p=0.02) than patients with negative culture. Multivariate analysis demonstrated that PaO₂/FiO₂ (adjusted odd ratio, 1.005; 95% confidence interval [CI], 1.002-1.008; p=0.005) was a significant risk factor for pathogen-positive culture. The area under the receiver operating characteristic curve of PaO₂/FiO₂ was 0.591 (95% CI, 0.510-0.669, p=0.05). Gram-negative pathogens (GNPs) were predominant and at least one GNP was observed in 84 (73.3%) patients among those with pathogen positive culture. Conclusion: We failed to find any clinical factors associated with positive culture results. Antibiotics that cover GNPs could be considered when deciding the initial antibiotic regimen at the time of suspected aspiration.

• Journal of Marine Bioscience and Biotechnology
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• v.16 no.1
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• pp.36-44
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• 2024

This study attempted to improve the growth of the freshwater microalgae, Parachlorella kessleri, through the sequential optimization of culture conditions. This attempt aimed to enhance the microalgae's ability to fixate atmospheric CO₂. Culture temperature and light intensity appropriate for microalgal growth were scanned using a high-throughput photobioreactor system. The supplied air flow rate varied from 0.05 to 0.3 vvm, and its effect on the growth rate of P. kessleri was determined. Next, sodium phosphate buffer was added to the culture medium (BG11) to enhance CO₂ fixation by increasing the availability of CO₂(HCO₃^-) in the culture medium. The results indicated that optimal culture temperature and light intensity were 20℃-25℃ and 300 μE/m²/s, respectively. Growth rates of P. kessleri under various air flow rates highly depended on the increase of the culture's flow rate and pH which determines CO₂ availability. Adding sodium phosphate buffer to BG11 to maintain a constant neutral pH (7.0) improved microalgal growth compared to control conditions (BG11 without sodium phosphate). These results indicate that the CO₂ fixation rate in the air could be enhanced via the sequential optimization of microalgal culture conditions.

• Fisheries and Aquatic Sciences
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• v.25 no.10
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• pp.525-536
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• 2022

Photosynthetic bacteria (PSB) attract considerable interest as useful microorganisms; nevertheless, a generalized culture technique has not been previously reported owing to difficulty in their cultivation. Therefore, a simple culture technique suitable for public use was investigated. Among the PSB tested, the strain Rhodobacter azotoformans EBN-7 was the most suitable for scale-up production because it showed the highest specific growth rate (0.20 h^-1) on basal medium. In scale-up cultivation (500 L), R. azotoformans EBN-7 showed 4.50 × 10¹⁰ colony-forming units mL^-1 (number of viable cells), dry cell weight of 26.8 g/L, and a specific growth rate of 0.15 h^-1. Cultivation using this final culture broth (as seed culture) in a 15 L simple reactor was successful, with maintenance of cell activity evident. For use as seed culture, the maximum allowable preservation period of R. azotoformans EBN-7 at 4℃ was 3 months. When R. azotoformans EBN-7 cultivated in a simple technique was applied to shrimp aquaculture water, NH₄⁺-N was reduced from 0.61 mg/L to 0.24 mg/L (by 60.7%) in 4 days in comparison with the control. Thus, this simple culture technique using R. azotoformans EBN-7 has the potential for a good removal efficiency of NH₄⁺-N, making seed culture easier and suitable for public use.

• Journal of Life Science
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• v.25 no.6
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• pp.673-679
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• 2015

The culture conditions needed to maximize the production of laccase from Pholiota highlandensis mycelia were investigated. Among the tested media for laccase production, Coriolus versicolor medium (CVM; 2% dextrose, 0.4% peptone, 0.6% yeast extract, 0.046% KH₂PO₄, 0.1% K₂HPO₄, 0.05% MgSO₄·7H₂O) showed the highest activity for the enzyme. Then, to optimize culture conditions for laccase activity, the influences of various carbon, nitrogen, phosphorus, and inorganic salt sources in CVM were investigated. The optimum culture medium was 2% fructose, 0.4% peptone with 0.6% yeast extract, 0.05% NaH₂PO₄, and 0.05% MgSO₄·7H₂O as carbon, nitrogen, phosphorus, and inorganic salt sources, respectively. Several aromatic compounds in the medium enhanced laccase activity to varying degrees. Guaiacol induced maximum laccase production, yielding 114.1 U/ml laccase activity after cultivation for 11 days at 25℃. The optimum pH and temperature for laccase production were 8.0 and 35℃, respectively. Native polyacrylamide-gel electrophoresis (PAGE) followed by laccase-activity staining with 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) as the substrate was performed to identify the presence of laccase under the optimum conditions studied. Zymogram analysis of the supernatant culture showed an enzymatic band with a molecular mass of about 90 kDa.

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.5
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• pp.1165-1174
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• 2014

The research was conducted on 238 marine sports participants by clarifying the relationship among self-efficacy, sociality, and organization culture, to eliminate the organizational(home, school, club, workplace, etc.) culture maladjustment phenomenon which is caused by personal stress, the lack of physical activity, and the lack of sociality due to the rapid change of modern society and enhance sociality, adjustment to society and the lack of creativity due to the rigid hierarchy and contribute to organization culture through marine sports among sports which we enjoy with nature. Firstly, according to general self-efficacy, and social characteristics of the organizational culture and the gender differences in higher than women in all sub-variables of the sub-factors of self-efficacy and self-regulation, sociability, organizational culture, sub-culture and develop cultural factors agreed man showed that in the sub-factors of organization culture showed that the development of high culture and hierarchical culture in the age of 20s. Secondly, in terms of the effect of self-efficacy of marine sports participants on sociality, it is found that self-regulation and level of difficulty positively influence on the culture of agreement, the culture of development and the culture of hierarchy. Lastly, in terms of the effect of self-efficacy of marine sports participants on organizational culture, it is shown that self-regulation has positive influence on the culture of agreement, the culture of development and the culture of hierarchy.

• YAKHAK HOEJI
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• v.24 no.3_4
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• pp.143-150
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• 1980

The effect of ginseng saponin on chick embryonic dorsal root ganglia organ culture and brain, spinal cord, muscle dissociation cultures was studied. The fiber outgrowth in explanted chick embryonic dorsal root ganglia was markedly induced by water and alcohol extracts of ginseng, total ginseng saponin, protopanaxadiol and protopanaxatriol glycosides as well as ginsenosides R/sub b1/, R/sub d/, R/sub 0/+R/sub a/+R/sub b1/, and R/sub b2/+R/sub c/+R/sub e/ mixtures. The life span of the cultured chick embryonic dorsal root ganglia and potentiation of nerve cell density were also observed with all of these ginseng saponins. The effect of ginseng saponin on chick embryonic dorsal root ganglia organ culture was more marked in the absence of the chick embryonic extract which was known to contain nerve growth factor-like material in the culture media. However, the ginseng saponin did not influence the cultured central nervous system such as brain and spinal cord cells and cultured skeletal muscle cells with respect to the morphological changes, maturation and life span of these cells.

• The Plant Pathology Journal
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• v.36 no.6
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• pp.558-569
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• 2020

Fusarium head blight (FHB) is a devastating fungal disease of wheat (Triticum aestivum L.). The lack of genetic resources with stable FHB resistance combined with a reliable and rapid screening method to evaluate FHB resistance is a major limitation to the development of FHB resistant wheat germplasm. The present study utilized an immature wheat spike culture method to screen wheat spike culture derived variants (SCDV) for FHB resistance. Mycotoxin concentrations determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS) correlated significantly (P < 0.01) with FHB severity and disease progression during in vitro spike culture. Selected SCDV lines assessed for FHB resistance in a Fusarium field disease nursery in Carman, Manitoba, Canada in 2016 showed significant (P < 0.01) correlation of disease severity to the in vitro spike culture screening method. Selected resistant SCDV lines were also crossed with an elite cv. CDC Hughes and the progeny of F₂ and BC₁F₂ were screened by high resolution melt curve (HRM) analyses for the wheat UDP-glucosyl transferase gene (TaUGT-3B) single nucleotide polymorphism to identify resistant (T-allele) and susceptible (G-allele) markers. The progeny from the crosses were also screened for FHB severity using the immature spike culture method and identified resistant progeny grouped according to the HRM genotyping data. The results demonstrate a reliable approach using the immature spike culture to screen for FHB resistance in progeny of crosses in early stage of breeding programs.

• Journal of Life Science
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• v.26 no.1
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• pp.68-74
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• 2016

Perchlorate (ClO₄⁻) is an emerging pollutant detected in surface water, soil, and groundwater. Previous studies provided experimental evidence of autotrophic ClO₄⁻ removal with elemental sulfur (S⁰) particles and activated sludge, which are inexpensive and easily available, respectively. In addition, ClO₄⁻ removal efficiency was shown to increase when an enrichment culture was used as an inoculum instead of activated sludge. PCR-DGGE was employed in the present study to investigate the microbial community in the enrichment culture that removed ClO₄⁻ autotrophically. Microorganisms in the enrichment culture showed 99.71% or more ClO₄⁻ removal efficiency after a 7-day incubation when the initial concentration was approximately 120 mg ClO₄⁻/l. Genomic DNA was isolated from the enriched culture and its inoculum (activated sludge), and used for PCR-DGGE analysis of 16S rRNA genes. Microbial compositions of the enrichment culture and the activated sludge were different, as determined by their different DGGE profiles. The difference in DGGE banding patterns suggests that environmental conditions of the enrichment culture caused a change in the microbial community composition of the inoculated activated sludge. Dominant DGGE bands in the enrichment culture sample were affiliated with the classes β-Proteobacteria, Bacteroidetes, and Spirochaetes. Further investigation is warranted to reveal the metabolic roles of the dominant populations in the ClO₄⁻ degradation process, along with their isolation.

• Journal of Microbiology and Biotechnology
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• v.30 no.8
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• pp.1244-1251
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• 2020

Phospholipase A₂ (PLA₂) from Streptomyces violaceoruber is a lipolytic enzyme used in a wide range of industrial applications including production of lysolecithins and enzymatic degumming of edible oils. We have therefore investigated expression and secretion of PLA₂ in two workhorse microbes, Pichia pastoris and Escherichia coli. The PLA₂ was produced to an activity of 0.517 ± 0.012 U/ml in the culture broth of the recombinant P. pastoris. On the other hand, recombinant E. coli BL21 star (DE3), overexpressing the authentic PLA₂ (P-PLA₂), showed activity of 17.0 ± 1.3 U/ml in the intracellular fraction and 21.7 ± 0.7 U/ml in the culture broth. The extracellular PLA2 activity obtained with the recombinant E. coli system was 3.2-fold higher than the corresponding value reached in a previous study, which employed recombinant E. coli BL21 (DE3) overexpressing codon-optimized PLA₂. Finally, we observed that the extracellular PLA₂ from the recombinant E. coli P-PLA₂ culture was able to hydrolyze 31.1 g/l of crude soybean lecithin, an industrial substrate, to a conversion yield of approximately 95%. The newly developed E. coli-based PLA₂ expression system led to extracellular production of PLA₂ to a productivity of 678 U/l·h, corresponding to 157-fold higher than that obtained with the P. pastoris-based system. This study will contribute to the extracellular production of a catalytically active PLA₂.