• Title/Summary/Keyword: Microbial survival

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Micropropagation from root segments to improve seedling quality in Chinese foxglove crops

  • Pham, Thanh Loan;Nguyen, Van Huy;Hoang, Thi Le Thu;Ha, Thi Tam Tien;Tran, Trung Kien;Vu, Xuan Duong;Cao, Phi Bang;Nguyen, Quang Trung
    • Journal of Plant Biotechnology
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    • v.47 no.3
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    • pp.235-241
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    • 2020
  • This is the first study to establish a complete protocol for micropropagation of Rehmannia glutinosa from root segments. The study involved investigating the effect of plant growth regulators on in vitro shoot regeneration and rooting and identifying substrates supporting survival and growth performance of ex vitro seedlings. A Murashige and Skoog (MS) medium containing 30 g/L sucrose for shoot induction and 0.2 mg/L indole-3-acetic acid (IAA), 1 mg/L 6-benzylaminopurine (BAP), and 1 g/L polyvinylpyrrolidone (PVP) for shoot multiplication resulted in the highest number of shoots per explant and shoot height. Applying a medium containing 0.5 mg/L IAA and 1 g/L PVP yielded optimal rooting of the shoots grown in vitro. Compost enriched with microbial inoculants and perlite enhanced seedling growth better than that with organic biofertilizer-free substrates (soil and sand). We recommend the continuous production of micropropagated R. glutinosa seedlings from root segments under the aforementioned conditions as a possible propagation technique for crops of this species.

Emerging and Established Global Life-Style Risk Factors for Cancer of the Upper Aero-Digestive Tract

  • Gupta, Bhawna;Johnson, Newell W.
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.15
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    • pp.5983-5991
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    • 2014
  • Introduction: Upper aero-digestive tract cancer is a multidimensional problem, international trends showing complex rises and falls in incidence and mortality across the globe, with variation across different cultural and socio-economic groups. This paper seeks some explanations and identifies some research and policy needs. Methodological Approach: The literature illustrates the multifactorial nature of carcinogenesis. At the cellular level, it is viewed as a multistep process involving multiple mutations and selection for cells with progressively increasing capacity for proliferation, survival, invasion, and metastasis. Established and emerging risk factors, in addition to changes in incidence and prevalence of cancers of the upper aero-digestive tract, were identified. Risk Factors: Exposure to tobacco and alcohol, as well as diets inadequate in fresh fruits and vegetables, remain the major risk factors, with persistent infection by particular so-called "high risk" genotypes of human papillomavirus increasingly recognised as also playing an important role in a subset of cases, particularly for the oropharynx. Chronic trauma to oral mucosa from poor restorations and prostheses, in addition to poor oral hygiene with a consequent heavy microbial load in the mouth, are also emerging as significant risk factors. Conclusions: Understanding and quantifying the impact of individual risk factors for these cancers is vital for health decision-making, planning and prevention. National policies and programmes should be designed and implemented to control exposure to environmental risks, by legislation if necessary, and to raise awareness so that people are provided with the information and support they need to adopt healthy lifestyles.

Dynamics Associated with Prolonged Ensiling and Aerobic Deterioration of Total Mixed Ration Silage Containing Whole Crop Corn

  • Wang, Huili;Ning, Tingting;Hao, Wei;Zheng, Mingli;Xu, Chuncheng
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.1
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    • pp.62-72
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    • 2016
  • This study investigated the dynamics associated with prolonged ensiling and aerobic deterioration of whole crop corn (WCC) silages and total mixed ration (TMR) silages containing WCC (C-TMR silages) to clarify the differences that account for the enhanced aerobic stability of TMR silages. Laboratory-scale barrel silos were randomly opened after 7, 14, 28, and 56 d of ensiling and were subjected to analyses of fermentation quality, microbial and temperature dynamics during aerobic exposure. WCC and C-TMR silages were both well preserved and microorganisms were inhibited with prolonged ensiling, including lactic acid bacteria. Yeast were inhibited to below the detection limit of 500 cfu/g fresh matter within 28 d of ensiling. Aerobic stability of both silages was enhanced with prolonged ensiling, whereas C-TMR silages were more aerobically stable than WCC silages for the same ensiling period. Besides the high moisture content, the weak aerobic stability of WCC silage is likely attributable to the higher lactic acid content and yeast count, which result from the high water-soluble carbohydrates content in WCC. After silo opening, yeast were the first to propagate and the increase in yeast levels is greater than that of other microorganisms in silages before deterioration. Besides, increased levels of aerobic bacteria were also detected before heating of WCC silages. The temperature dynamics also indicated that yeast are closely associated with the onset of the aerobic deterioration of C-TMR silage, whereas for WCC silages, besides yeast, aerobic bacteria also function in the aerobic deterioration. Therefore, the inclusion of WCC might contribute to the survival of yeast during ensiling but not influence the role of yeast in deterioration of C-TMR silages.

Components of human breast milk: from macronutrient to microbiome and microRNA

  • Kim, Su Yeong;Yi, Dae Yong
    • Clinical and Experimental Pediatrics
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    • v.63 no.8
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    • pp.301-309
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    • 2020
  • Human breast milk (HBM) is essential for the infant's growth and development right after birth and is an irreplaceable source of nutrition for early human survival. Various infant formulas have many similarities to HBM in many components, but there is no perfect substitute for HBM. Recently, various breast milk components and their roles have been studied according to the development of various analysis techniques. As is already well known, HBM contains about 87%-88% water, and 124-g/L solid components as macronutrients, including about 7% (60-70 g/L) carbohydrates, 1% (8-10 g/L) protein, and 3.8% (35-40 g/L) fat. The composition may vary depending on the environmental factors, including maternal diet. Colostrum is low in fat but high in protein and relatively rich in immuneprotective components. Although HBM contains enough vitamins to ensure normal growth of the infant, vitamins D and K may be insufficient, and the infant may require their supplementation. Growth factors in HBM also serve as various bioactive proteins and peptides on the intestinal tract, vasculature, nervous system, and endocrine system. In the past, HBM of a healthy mother was thought to be sterile. However, several subsequent studies have confirmed the presence of rich and diverse microbial communities in HBM. Some studies suggested that the genera Staphylococcus and Streptococcus may be universally predominant in HBM, but the origin of microbiota still remains controversial. Lastly, milk is the one of most abundant body fluid of microRNAs, which are known to play a role in various functions, such as immunoprotection and developmental programming, through delivering from HBM and absorption by intestinal epithelial cells. In conclusion, HBM is the most important source of nutrition for infants and includes microbiomes and miRNAs for growth, development, and immunity.

Fate of Genetically Engineered 2,4-D-Degrading Microorganisms in Natural Soils and Waters

  • Hong, Seok-Myeong;Lee, Yin-Won;Kim, Chi-Kyung;Ka, Jong-Ok
    • Journal of Microbiology
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    • v.34 no.4
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    • pp.320-326
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    • 1996
  • To analyze the effects of host versus plasmid on survival of 2, 4-degrading bacteria in environmental samples, strains Pseudomonas cepacia/pJP4, Alcaligenes JMP228/pJP4, P. cepacia/p712, and Alcaligenes JMP228/p712 were separately inoculated into samples of field soil, paddy soil, lake water, and river water, and then the changes of their populations were measured. The strains used contained a 2, 4-D degradative plasmid, either pJP4 conferring fast-growing property to the host or p712 conferring slow-growing property, and were resistant to antibiotics such that the inoculated strains could be enumerated against the indigenous microbial populations. In sterile environmental samples, these strains were stably maintained at the levels used for inoculation, except in sterile paddy soil where Alcaligenes JMP228 strains died drapidly. In natural soil samples for four strains declined steadily with time, but in naturla water samples their polulations fell rapidly at the early phase and then remained almost constant. When the environmentla samples were treated with 2, 4-D, P. cepacia/pJP4 and P. cepacia/p712 maintained significant numbers, while Alcaligenes JMP228/pJP4 and Alcaligenes JMP228/p712 declined significantly in most of the samples. The results indicated that the survivability of genetically modified microorganisms could vary depending on the environments and that their abundance in the environments under s2, 4-D selection was markedly influenced by the nature of the 2, 4-D degradative plasmid as well as type of the host strain.

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The Cytotoxic and Apoptotic Effect of Pseudomonas aeruginosa Exotoxin A on Human Leukemia K-562 Cells (인간 백혈병 세포에서 Psuedomonas aeruginosa exotoxin A에 대한 세포독성과 세포자멸사 효과)

  • Chang, Jeong-Hyun;Kwon, Heun-Young
    • Korean Journal of Clinical Laboratory Science
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    • v.39 no.2
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    • pp.68-75
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    • 2007
  • After reports on regression of cancer in humans and animals infected with microbial pathogens date back more than 100 years, much effort has been spent over the years in developing a wild type or attenuated bacterial and purified bacterial proteins for the treatment of cancer. Pseudomonas aeruginosa exotoxin A (ETA) is known to inhibit cell growth and trigger significant cell death in various cancer cells. Although ETA induces apoptosis of cancer cells, its exact mechanism of action is not known yet. Four different assays were performed in this study: morphological assessment of apoptotic cells, cell cytotoxity, annexin-V binding assay, and cell cycle analysis. The proliferation and survival of the K-562 cells treated with ETA were decreased in a dose dependent manner. In addition, the apoptotic body of K-562 cells was induced by ETA treatment in a dose dependent manner. The ETA-induced apoptosis was confirmed by annexin-V binding assay. Flow cytometric analysis was examined to ascertain whether ETA could arrest the cell cycle at the sub-G1 phase. Our results suggest that P. aeruginosa ETA inhibits cell growth and induces apoptosis in human leukemia K-562 cells.

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Optimization of Screw Pumping System (SPS) for Mass Production of Entrapped Bifidus

  • Ryu, Ji-Sung;Lee, Yoon-Jong;Choi, Soo-Im;Lee, Jae-Won;Heo, Tae-Ryeon
    • Food Science and Biotechnology
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    • v.14 no.5
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    • pp.566-571
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    • 2005
  • Process of screw-pumping system (SPS) was optimized for mass production of encapsulated bifidus. SPS entrapment device was composed of feeding component, with optimized nozzle size and length of 18G (0.91 cm) and 4 mm, respectively, screw pump, and 37-multi-nozzle. Screw component had five wing turns [radius (r)=26 to 15 mm] from top to bottom of axis at 78-degree angle from middle of the screw, and two wings were positioned at screw edge to push materials toward nozzle. For nozzle component, 37 nozzles were attached to 20-mm round plate. Air compressor was attached to SPS to increase productivity of encapsulated bifidus. This system could be operated with highly viscous (more than 300 cp) materials, and productivity was higher than $1128\;{\pm}\;30\;beads/min$. Viability of encapsulated bifidus was $5.45\;{\times}\;10^8\;cfu$/bead, which is superior to that of encapsulated bifidus produced by other methods ($2.51{\times}10^8\;cfu$/bead). Average diameter of produced beads was $2.048\;{\pm}\;0.003\;mm$. Survival rate of SPS-produced encapsulated bifidus was 90% for Simulator of the Human Intestinal Microbial Ecosystem test and 88% in fermented milk (for 14 days). These results show SPS is effective for use in development of economical system for mass production of viable encapsulated bifidus.

Effects of Washing and Storage Temperature on Quality and Safety of Washed Shell Eggs (세척 수 및 보관온도가 세척 식용란 품질과 안전에 미치는 영향)

  • Choi, Bum-Geun;Min, Ji-Hyeon;Yoon, Ki-Sun
    • Journal of the East Asian Society of Dietary Life
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    • v.27 no.1
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    • pp.78-87
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    • 2017
  • The objective of this study was to investigate the effects of various washing waters on the quality and safety characteristics of eggs during storage. Eggs were washed with tap water, 100 ppm of sodium hypochlorite, or 30 ppm of slightly acidic electrolyzed water and stored at $10^{\circ}C$ and $20^{\circ}C$. Effects of various washing waters on reduction of Salmonella Enteritidis and aerobic plate counts and survival of S. Enteritidis on egg shells were also analyzed at $10^{\circ}C$ and $20^{\circ}C$ for 25 days. As an index of quality, haugh unit, weight reduction, and pHs of egg white and egg yolk were measured. Reduction percentages of haugh unit and weight were higher at $20^{\circ}C$ than at $10^{\circ}C$. Egg qualities were less affected by tap water, slightly acidic electrolyzed water, and sodium hypochlorite, regardless of storage temperature. The greatest reductions in aerobic plate counts and S. Enteritidis were observed with slightly acidic electrolyzed water. The level of S. Enteritidis on egg shells gradually decreased during 20 days of storage at both $10^{\circ}C$ and $20^{\circ}C$, whereas S. Enteritidis survived longer at $20^{\circ}C$ than at $10^{\circ}C$. S. Enteritidis was not detected in eggs at $10^{\circ}C$, 2.13 log CFU/g of S. Enteritidis was detected in eggs washed with sodium hypochlorite after 20 days of storage at $20^{\circ}C$, indicating that S. Enteritidis penetrated into the egg shell during storage at $20^{\circ}C$. In conclusion, slightly acidic electrolyzed water increased microbial reduction and least affected quality of washed eggs. Thus, slightly acidic electrolyzed water can be recommended for washing of graded eggs, at retail markets.

Isolation and Characterization of Lactobacillus fermentum YL-3 as a poultry probiotic. (가금류 생균제 개발을 위한 Lactobacillus fermentum YL-3의 분리 및 생리 특성)

  • Cho, Mun-Kyoung;Kim, Kyong;Kim, Chung-Ho;Lee, Tae-Keun;Kim, Kwang-Yup
    • Microbiology and Biotechnology Letters
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    • v.28 no.5
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    • pp.279-284
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    • 2000
  • This study was per-formed to screen lactic acid bacteria poultry for the probiotic use. Among the previously obtained acid tolerant, 139 strains, 111 strains were selected with MRS medium containing 0.3% oxgall. 34 strains of 111 was re-selected by Gram-staining and acid producing ability. These strains was identified by MIDI Sherlock Microbial Identification System. Among the identified 34 strains Lactobacillus fermenum YL-3 was selected for the final pro-biotic use because of the good growth and high survival rate at pH 2.0. 60%, 50% and 40% cells of Lactobacillus fermentum YL-3 survived at pH 3.0, 2.5 and 2.0, respectively. More than $10^{7}$ / CFU/ml survived when exposed with the number of $10^{8}$ CFU/ml at pH 2.0 after 12 hr. L.fermenum YL-3 maintained growth in MRS broth containing 0.3, 0.5, 1.0 and 2.0% oxgall for 24 hr. L.fermenum YL-3 showed an inhibitory effect against pathogenic strains of Sal. enteritidis and E. coli O157:H7. In mixed culture with L.fermenum YL-3 Sal. enteritidis lost ability com-pletely in 15 hrs and E. coil O157:H7 in 16 hrs.

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A Human Fungal Pathogen Cryptococcus neoformans Expresses Three Distinct Iron Permease Homologs

  • Han, Kyunghwan;Do, Eunsoo;Jung, Won Hee
    • Journal of Microbiology and Biotechnology
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    • v.22 no.12
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    • pp.1644-1652
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    • 2012
  • Iron plays a key role in host-pathogen interactions. Microbial pathogens require iron for survival and virulence, whereas mammalian hosts sequester and withhold iron as a means of nutritional immunity. We previously identified two paralogous genes, CFT1 and CFT2, which encode homologs of a fungal iron permease, Cft1 and Cft2, respectively, in the human fungal pathogen Cryptococcus neoformans. Cft1 was shown to play a role in the high-affinity reductive iron uptake system, and was required for transferrin utilization and full virulence in mammalian hosts. However, no role of Cft2 has been suggested yet. Here, we identified the third gene, CFT3, that produces an additional fungal iron permease homolog in C. neoformans, and we also generated the cft3 mutant for functional characterization. We aimed to reveal distinct functions of Cft1, Cft2 and Cft3 by analyzing phenotypes of the mutants lacking CFT1, CFT2 and CFT3, respectively. The endogenous promoter of CFT1, CFT2 and CFT3 was replaced with the inducible GAL7 promoter in the wild-type strain or in the cft1 mutant for gain-of-function analysis. Using these strains, we were able to find that CFT2 is required for growth in low-iron conditions in the absence of CFT1 and that overexpression of CFT2 compensates for deficiency of the cft1 mutant in iron uptake and various cellular stress conditions. However, unlike CFT2, no clear phenotypic characteristic of the cft3 mutant and the strain overexpressing CFT3 was observed. Overall, our data suggested a redundant role of Cft2 in the high-affinity iron uptake and stress responses in C. neoformans.