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Kamdem MM, Otomo PV. Developmental performance of Eristalis tenax larvae (Diptera: Syrphidae): Influence of growth media and yeast addition during captive rearing. J Exp Zool A Ecol Integr Physiol 2023; 339:503-513. [PMID: 36958945 DOI: 10.1002/jez.2696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 03/04/2023] [Accepted: 03/10/2023] [Indexed: 03/25/2023]
Abstract
In holometabolous insects, life-history characteristics can vary in response to diet. The main aim of this contribution was to examine which diet best promotes larval development and survival of the aquatic saprophagous hoverfly Eristalis tenax L. (Diptera: Syrphidae). This study was motivated by a need to optimize techniques for rearing these insects in captivity. We studied how adding yeast to several rearing media based on animal droppings or decaying plant material affected development and survival in captive larvae, and whether these effects could be optimized depending on the amount of yeast and the rearing medium. In addition, premature exit of larvae was examined in two medium volumes to investigate differences in pupation. Larvae in yeast supplemented rabbit growth medium pupated and emerged faster than those in horse and antelope growth media. A high number of adult females emerged when compared to males, and both seemed to have a shorter developmental period in yeast supplemented growth media. Pupal survival was significantly greater in a mixture of droppings and plant organic matter, and a high medium volume of 140 ml (p < 0.05). Between 10% and 17% of larvae prematurely exited the aquatic medium in high (140) and low (70 ml) medium volumes, respectively. These results provide additional information that may be crucial for the successful mass rearing of E. tenax in captivity, and suggest that apart from the addition of yeast, growth medium quality and volume may be limiting factors for the production of large colonies of adults.
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Affiliation(s)
- Michel Mathurin Kamdem
- Department of Zoology and Entomology, University of the Free State, Phuthaditjhaba, South Africa
| | - Patricks Voua Otomo
- Department of Zoology and Entomology, University of the Free State, Phuthaditjhaba, South Africa
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2
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Gong H, Zeng Z, Tessier L, Guzman L, Yuan Z, Li S, Zheng W, Chen Y, Qi L. Survival on land: A dark-grown seedling searching for path. Front Plant Sci 2023; 14:1110521. [PMID: 36818829 PMCID: PMC9932276 DOI: 10.3389/fpls.2023.1110521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 01/24/2023] [Indexed: 06/18/2023]
Abstract
To initiate its development into a plant, a small dark-grown seedling (prior to its emergence from the ground) must penetrate through the growth media. The path that the seedling takes during this journey has yet to be explained. As such, we conducted non-destructive tests using CT scans to observe the growth of dark-grown seedlings in soil over time; we also developed a model to simulate the dynamics of an emerging seedling, and to examine effects of various growth medium conditions, including Lunar soil. It was previously postulated that, with gravitropism in a terrestrial growth medium, a dark-grown seedling would grow directly upright. However, our CT scan results showed that dark-grown soybean seedlings departed from the vertical path in soil, as far as a lateral distance of approximately 10 mm. The phenomenon of the non-straight path was also demonstrated by the model results. Through simulations, we found that an emerging seedling naturally weaves through the particles of growth medium, in search for the path of least resistance. As a result, the seedling ends up travelling a longer distance. Compared with a seedling that was artificially forced to take a straight path in a growth media, the seedling taking the natural path encountered significantly lower resistances (20% lower) from the growth medium, while travelled 12% longer distance during the emergence process. A seedling encountered a much higher impedance in Lunar soil. Our results suggest that taking the path of least resistance, in addition to shaping and orientating itself for mechanical advantage, are strategies evolved by plant species that have contributed to its vast success. An understanding of plant behavior and survival strategies on Earth lay the foundation for future research in agriculture in novel environments, including on celestial bodies.
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Affiliation(s)
- Hao Gong
- College of Engineering, South China Agricultural University, Guangzhou, Guangdong, China
- Department of Biosystems Engineering, University of Manitoba, Winnipeg, MB, Canada
| | - Zhiwei Zeng
- Department of Agricultural Engineering Technology, University of Wisconsin-River Falls, WI, River Falls, United States
| | - Léa Tessier
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Leno Guzman
- Department of Biosystems Engineering, University of Manitoba, Winnipeg, MB, Canada
| | - Zihao Yuan
- College of Engineering, South China Agricultural University, Guangzhou, Guangdong, China
| | - Shuai Li
- College of Engineering, South China Agricultural University, Guangzhou, Guangdong, China
| | - Wenhan Zheng
- College of Engineering, South China Agricultural University, Guangzhou, Guangdong, China
| | - Ying Chen
- Department of Biosystems Engineering, University of Manitoba, Winnipeg, MB, Canada
| | - Long Qi
- College of Engineering, South China Agricultural University, Guangzhou, Guangdong, China
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3
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Steinrücken P, Jackson S, Müller O, Puntervoll P, Kleinegris DMM. A closer look into the microbiome of microalgal cultures. Front Microbiol 2023; 14:1108018. [PMID: 36778846 PMCID: PMC9908576 DOI: 10.3389/fmicb.2023.1108018] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 01/10/2023] [Indexed: 01/27/2023] Open
Abstract
Although bacteria are commonly co-occurring in microalgal cultivation and production systems, little is known about their community structure and how it might be affected by specific microalgal groups or growth conditions. A better understanding about the underlying factors that determine the growth of specific bacterial populations is not only important for optimizing microalgal production processes, but also in the context of product quality when the algal biomass is to be used for future food or feed. We analyzed the bacterial community composition associated with nine microalgal strains in stock culture, maintained in two different growth media, to explore how specific taxonomic microalgal groups, microalgal origin, or the growth medium affect the bacterial community composition. Furthermore, we monitored the bacterial community composition for three Phaeodactylum strains during batch cultivation in bubble columns to examine if the bacterial composition alters during cultivation. Our results reveal that different microalgal genera, kept at the same cultivation conditions over many years, displayed separate and unique bacterial communities, and that different strains of the same genus had very similar bacterial community compositions, despite originating from different habitats. However, when maintained in a different growth medium, the bacterial composition changed for some. During batch cultivation, the bacterial community structure remained relatively stable for each Phaeodactylum strain. This indicates that microalgae seem to impact the development of the associated bacterial communities and that different microalgal genera could create distinct conditions that select for dominance of specific bacteria. However, other factors such as the composition of growth medium also affect the formation of the bacterial community structure.
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Affiliation(s)
- Pia Steinrücken
- Department of Biological Sciences, University of Bergen, Bergen, Norway,NORCE Climate & Environment - NORCE Norwegian Research Centre AS, Bergen, Norway,*Correspondence: Pia Steinrücken, ✉
| | - Steve Jackson
- Department of Biological Sciences, University of Bergen, Bergen, Norway
| | - Oliver Müller
- Department of Biological Sciences, University of Bergen, Bergen, Norway
| | - Pål Puntervoll
- NORCE Climate & Environment - NORCE Norwegian Research Centre AS, Bergen, Norway
| | - Dorinde M. M. Kleinegris
- Department of Biological Sciences, University of Bergen, Bergen, Norway,NORCE Climate & Environment - NORCE Norwegian Research Centre AS, Bergen, Norway
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4
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Straub H, Zuber F, Eberl L, Maniura-Weber K, Ren Q. In Situ Investigation of Pseudomonas aeruginosa Biofilm Development: Interplay between Flow, Growth Medium, and Mechanical Properties of Substrate. ACS Appl Mater Interfaces 2023; 15:2781-2791. [PMID: 36601891 DOI: 10.1021/acsami.2c20693] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
To better understand the impact of biomaterial mechanical properties and growth medium on bacterial adhesion and biofilm formation under flow, we investigated the biofilm formation ability of Pseudomonas aeruginosa in different media on polydimethylsiloxane (PDMS) of different stiffness in real time using a microfluidic platform. P. aeruginosa colonization was recorded with optical microscopy and automated image analysis. The bacterial intracellular level of cyclic diguanylate (c-di-GMP), which regulates biofilm formation, was monitored using the transcription of the putative adhesin gene (cdrA) as a proxy. Contrary to the previous supposition, we revealed that PDMS material stiffness within the tested range has negligible impact on biofilm development and biofilm structures, whereas culture media not only influence the kinetics of biofilm development but also affect the biofilm morphology and structure dramatically. Interestingly, magnesium rather than previously reported calcium was identified here to play a decisive role in the formation of dense P. aeruginosa aggregates and high levels of c-di-GMP. These results demonstrate that although short-term adhesion assays bring valuable insight into bacterial and material interactions, long-term evaluations are essential to better predict overall biofilm outcome. The microfluidic system developed here presents a valuable application potential for studying biofilm development in situ. .
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Affiliation(s)
- Hervé Straub
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen CH-9014, Switzerland
- Department of Plant and Microbial Biology, University of Zürich, Zürich CH-8008, Switzerland
| | - Flavia Zuber
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen CH-9014, Switzerland
| | - Leo Eberl
- Department of Plant and Microbial Biology, University of Zürich, Zürich CH-8008, Switzerland
| | - Katharina Maniura-Weber
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen CH-9014, Switzerland
| | - Qun Ren
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen CH-9014, Switzerland
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5
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Jolman D, Batalla MI, Hungerford A, Norwood P, Tait N, Wallace LE. The challenges of growing orchids from seeds for conservation: An assessment of asymbiotic techniques. Appl Plant Sci 2022; 10:e11496. [PMID: 36258786 PMCID: PMC9575117 DOI: 10.1002/aps3.11496] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 08/12/2022] [Accepted: 08/18/2022] [Indexed: 06/16/2023]
Abstract
Lewis Knudson first successfully germinated orchid seeds asymbiotically on artificial medium in 1922. While many orchid species have since been grown asymbiotically, the tremendous variation in how species respond to artificial medium and growth conditions ex situ has also become apparent in the past century. In this study, we reviewed published journal articles on asymbiotic orchid seed germination to provide a summary of techniques used and to evaluate if these differ between terrestrial and epiphytic species, to identify areas where additional research is needed, and to evaluate whether asymbiotic germination could be used more often in ex situ conservation. We found articles reporting successful asymbiotic germination of 270 species and 20 cultivars across Orchidaceae. Researchers often used different techniques with epiphytic versus terrestrial species, but species-specific responses to growth media and conditions were common, indicating that individualized protocols will be necessary for most species. The widespread success in generating seedlings on artificial media suggests that asymbiotic techniques should be another tool for the conservation of rare orchid species. Further advances are needed in understanding how to introduce mycorrhizae to axenically grown orchids and to maximize the viability of seedlings reintroduced into natural habitats to fully utilize these methods for conservation.
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Affiliation(s)
- Devani Jolman
- Department of Biological SciencesOld Dominion UniversityNorfolkVirginia23529USA
| | - Martín I. Batalla
- Department of Biological SciencesOld Dominion UniversityNorfolkVirginia23529USA
| | - Alexis Hungerford
- Department of Biological SciencesOld Dominion UniversityNorfolkVirginia23529USA
| | - Pryce Norwood
- Department of Biological SciencesOld Dominion UniversityNorfolkVirginia23529USA
| | - Noah Tait
- Department of Biological SciencesOld Dominion UniversityNorfolkVirginia23529USA
| | - Lisa E. Wallace
- Department of Biological SciencesOld Dominion UniversityNorfolkVirginia23529USA
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6
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Gunadi A, Li F, Van Eck J. Accelerating gametophytic growth in the model hornwort Anthoceros agrestis. Appl Plant Sci 2022; 10:e11460. [PMID: 35495194 PMCID: PMC9039800 DOI: 10.1002/aps3.11460] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Accepted: 11/22/2021] [Indexed: 05/25/2023]
Abstract
PREMISE Hornworts belong to a unique lineage of bryophytes with critical traits for elucidating the evolution of land plants; however, the development of functional genetic tools for hornworts has been hampered by their relatively slow gametophytic growth. METHODS To identify the external factors that influence the development of hornwort gametophytes and potentially augment their growth, we evaluated the contributions of several culture medium components on the axenic gametophytic growth of Anthoceros agrestis, a model hornwort. A streamlined growth assay utilizing semiautomated image analysis was developed to rapidly quantify and compare tissue development spanning four weeks of culture on solidified medium. RESULTS The addition of sucrose, ammonium nitrate, activated charcoal, pH buffering, and growth regulators (2,4-dichlorophenoxyacetic acid, 6-benzylaminopurine, and thidiazuron) affected gametophyte tissue survival, growth patterns, and the rate of thalli growth. Subsequently, an optimized medium composition and growth regimen for accelerating A. agrestis gametophytic growth were formulated, which at four weeks of culture increased the tissue wet weight by 2.1- to 8.5-fold compared with other previously utilized hornwort growth media. DISCUSSION Our protocol for generating vigorous starting material and accelerated tissue regeneration is pertinent for advancing gene function characterization and genome editing in hornworts.
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Affiliation(s)
- Andika Gunadi
- Boyce Thompson Institute533 Tower RoadIthacaNew York14853USA
- Present address:
Simplot Plant SciencesJ.R. Simplot Company5369 W Irving StreetBoiseIdaho83706USA
| | - Fay‐Wei Li
- Boyce Thompson Institute533 Tower RoadIthacaNew York14853USA
- Plant Biology Section, School of Integrative Plant ScienceCornell UniversityIthacaNew York14853USA
| | - Joyce Van Eck
- Boyce Thompson Institute533 Tower RoadIthacaNew York14853USA
- Plant Breeding and Genetics Section, School of Integrative Plant ScienceCornell UniversityIthacaNew York14853USA
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7
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Katayama M, Onuma M, Fukuda T. KAv-1 is Better Suited to Chick Fibroblast Culture than DMEM or 199 Media. J Poult Sci 2021; 58:270-9. [PMID: 34899023 DOI: 10.2141/jpsa.0200085] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 02/01/2021] [Indexed: 12/27/2022] Open
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.
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8
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Zinn M, Egli T, Herwig C, Narang A. Editorial: Recent Advances in Continuous Cultivation. Front Bioeng Biotechnol 2021; 9:641249. [PMID: 33692991 PMCID: PMC7937790 DOI: 10.3389/fbioe.2021.641249] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Accepted: 01/19/2021] [Indexed: 11/18/2022] Open
Affiliation(s)
- Manfred Zinn
- Institute of Life Technology, School of Engineering, University of Applied Sciences Western Switzerland, Sion, Switzerland
| | - Thomas Egli
- Department of Environmental Systems Science, Swiss Federal Institute of Technology, Zurich, Switzerland.,Microbes-in-Water GmbH, Feldmeilen, Switzerland
| | - Christoph Herwig
- Christian Doppler Laboratory for Mechanistic and Physiological Methods for Improved Bioprocesses, Vienna, Austria.,Competence Center CHASE GmbH, Linz, Austria.,Research Area Biochemical Engineering, Institute of Chemical Engineering, Vienna, Austria
| | - Atul Narang
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi, India
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9
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Abstract
Reactive extracellular media focus on engineering reaction networks outside the cell to control intracellular chemical composition across time and space. However, current implementations lack the feedback loops and out-of-equilibrium molecular dynamics for encoding spatiotemporal control. Here, we demonstrate that enzyme-DNA molecular programs combining these qualities are functional in an extracellular medium where human cells can grow. With this approach, we construct an internalization program that delivers fluorescent DNA inside living cells and remains functional for at least 48 h. Its nonequilibrium dynamics allows us to control both the time and position of cell internalization. In particular, a spatially inhomogeneous version of this program generates a tunable reaction-diffusion two-band pattern of cell internalization. This demonstrates that a synthetic extracellular program can provide temporal and positional information to living cells, emulating archetypal mechanisms observed during embryo development. We foresee that nonequilibrium reactive extracellular media could be advantageously applied to in vitro biomolecular tracking, tissue engineering, or smart bandages.
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Affiliation(s)
- Marc Van Der Hofstadt
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine (IBPS), Laboratoire Jean Perrin (LJP), F-75005, Paris, France
| | - Jean-Christophe Galas
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine (IBPS), Laboratoire Jean Perrin (LJP), F-75005, Paris, France
| | - André Estevez-Torres
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine (IBPS), Laboratoire Jean Perrin (LJP), F-75005, Paris, France
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10
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Štumpf S, Hostnik G, Primožič M, Leitgeb M, Bren U. Generation Times of E. coli Prolong with Increasing Tannin Concentration while the Lag Phase Extends Exponentially. Plants (Basel) 2020; 9:plants9121680. [PMID: 33271746 PMCID: PMC7760653 DOI: 10.3390/plants9121680] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 11/27/2020] [Accepted: 11/29/2020] [Indexed: 05/10/2023]
Abstract
The current study examines the effect of tannins and tannin extracts on the lag phase duration, growth rate, and generation time of Escherichia coli. Effects of castalagin, vescalagin, gallic acid, Colistizer, tannic acid as well as chestnut, mimosa, and quebracho extracts were determined on E. coli's growth phases using the broth microdilution method and obtained by turbidimetric measurements. E. coli responds to the stress caused by the investigated antimicrobial agents with reduced growth rates, longer generation times, and extended lag phases. Prolongation of the lag phase was relatively small at low tannin concentrations, while it became more pronounced at concentrations above half the MIC. Moreover, for the first time, it was observed that lag time extensions follow a strict exponential relationship with increasing tannin concentrations. This feature is very likely a direct consequence of the tannin complexation of certain essential ions from the growth medium, making them unavailable to E. coli for its growth.
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Affiliation(s)
- Sara Štumpf
- Faculty of Chemistry and Chemical Engineering, University of Maribor, Maribor 2000, Slovenia; (S.Š.); (G.H.); (M.P.); (M.L.)
| | - Gregor Hostnik
- Faculty of Chemistry and Chemical Engineering, University of Maribor, Maribor 2000, Slovenia; (S.Š.); (G.H.); (M.P.); (M.L.)
| | - Mateja Primožič
- Faculty of Chemistry and Chemical Engineering, University of Maribor, Maribor 2000, Slovenia; (S.Š.); (G.H.); (M.P.); (M.L.)
| | - Maja Leitgeb
- Faculty of Chemistry and Chemical Engineering, University of Maribor, Maribor 2000, Slovenia; (S.Š.); (G.H.); (M.P.); (M.L.)
- Faculty of Medicine, University of Maribor, Maribor 2000, Slovenia
| | - Urban Bren
- Faculty of Chemistry and Chemical Engineering, University of Maribor, Maribor 2000, Slovenia; (S.Š.); (G.H.); (M.P.); (M.L.)
- Faculty of Mathematics, Natural Sciences and Information Technologies, University of Primorska, Koper 6000, Slovenia
- Correspondence: ; Tel.: +386-2-2294-421
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11
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Castillo-Alanis LA, González-Hernández AE, Quijano-Mateos A, Pedraza-Lara CS, Villavicencio-Queijeiro A, Bravo-Gómez ME. Standardization of a Culture Medium for Megaselia scalaris (Diptera: Phoridae) for Entomotoxicological Studies. J Med Entomol 2020; 57:1421-1431. [PMID: 32440684 DOI: 10.1093/jme/tjaa088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Indexed: 06/11/2023]
Abstract
One of the problems faced by entomotoxicological studies is the large variability of experimental set-ups and the absence of harmonized protocols to compare the data and results obtained by different research groups. Among the wide range of influencing factors on the development and growth of insects, food substrates are remarkably relevant. This article proposes a standardized growth medium to be employed in future entomotoxicological studies on the scuttle fly Megaselia scalaris (Loew, 1866), (Diptera: Phoridae). This species plays an important role in forensic cases related to the decomposition of human remains found indoors and/or in concealed environments, because of their small size and ability to enter these locations at an earlier time than many other insects. Because of these traits, it can be used for the estimation of the minimum postmortem interval (mPMI). We achieved the formulation of a medium that overcomes two traditional disadvantages of culture media used to raise necrophagous Diptera, the unknown media composition and different growth rates from those reared in tissue. The proposed medium is a known composition formulation, free of xenobiotics, in which M. scalaris shows growth rates and development times similar to those obtained when it is reared in tissue. This new diet might be used in future studies to test the effect of substances of forensic interest (prescription or illicit drugs, poisons, etc.) on the larval development time, helping to adjust the estimation of mPMI based on the presence of such substances. Additionally, the formulation revealed some interesting data about nutritional requirements of this species.
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Affiliation(s)
- Luz Alejandra Castillo-Alanis
- Laboratorio de Toxicología y Química Forense, Ciencia Forense, Facultad de Medicina, Universidad Nacional Autónoma de México. ZC, Mexico City, Mexico
| | - Ana Edith González-Hernández
- Laboratorio de Toxicología y Química Forense, Ciencia Forense, Facultad de Medicina, Universidad Nacional Autónoma de México. ZC, Mexico City, Mexico
| | - Alejandra Quijano-Mateos
- Laboratorio de Toxicología y Química Forense, Ciencia Forense, Facultad de Medicina, Universidad Nacional Autónoma de México. ZC, Mexico City, Mexico
| | - Carlos Salvador Pedraza-Lara
- Laboratorio de Entomología, Ciencia Forense, Facultad de Medicina, Universidad Nacional Autónoma de México. ZC, Mexico City, Mexico
| | - Alexa Villavicencio-Queijeiro
- Laboratorio de Genética, Ciencia Forense, Facultad de Medicina, Universidad Nacional Autónoma de México. ZC, Mexico City, Mexico
| | - María Elena Bravo-Gómez
- Laboratorio de Toxicología y Química Forense, Ciencia Forense, Facultad de Medicina, Universidad Nacional Autónoma de México. ZC, Mexico City, Mexico
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12
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Verni M, Minisci A, Convertino S, Nionelli L, Rizzello CG. Wasted Bread as Substrate for the Cultivation of Starters for the Food Industry. Front Microbiol 2020; 11:293. [PMID: 32184770 PMCID: PMC7058793 DOI: 10.3389/fmicb.2020.00293] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 02/10/2020] [Indexed: 11/29/2022] Open
Abstract
The amount of bread wasted daily worldwide, throughout its entire lifecycle, from production to distribution, is estimated to be hundreds of tons, therefore representing both economic and environmental issues. This work aimed at the valorization of wasted bread, setting-up a protocol for obtaining a growth medium to be used for the cultivation of food industry microbial starters. The optimization of the protocol included the set-up of parameters for the hydrolysis of the bread nutrient compounds with proteolytic and amylolytic enzymes and the supplementation with nitrogen and/or carbon sources. The suitability of the optimized medium for the growth of lactic acid bacteria, yeasts and fungi from dairy, bakery, and wine industries was assessed. Lactic acid bacteria growth was strongly affected by the quantity and quality of nitrogen sources employed, while yeasts and fungi growth exceeded that obtained with the reference media commonly employed for their cultivation. Wasted bread medium (WBM) represents a realistic option for the valorization and re-use of bread waste, responding to the modern vision of circular economy.
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Affiliation(s)
- Michela Verni
- Department of Soil, Plant and Food Sciences, University of Bari Aldo Moro, Bari, Italy
| | | | | | | | - Carlo G Rizzello
- Department of Soil, Plant and Food Sciences, University of Bari Aldo Moro, Bari, Italy
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13
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Roberts TM, Kaltenbach HM, Rudolf F. Development and optimisation of a defined high cell density yeast medium. Yeast 2020; 37:336-347. [PMID: 32065695 DOI: 10.1002/yea.3464] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 01/31/2020] [Accepted: 02/03/2020] [Indexed: 01/05/2023] Open
Abstract
Saccharomyces cerevisiae cells grown in a small volume of chemically defined media neither reach the desired cell density nor grow at a fast enough rate to scale down the volume and increase the sample number of classical biochemical assays, as the detection limit of the readout often requires a high number of cells as an input. To ameliorate this problem, we developed and optimised a new high cell density (HCD) medium for S. cerevisiae. Starting from a widely used synthetic medium composition, we systematically varied the concentrations of all components without the addition of other compounds. We used response surface methodology to develop and optimise the five components of the medium: glucose, yeast nitrogen base, amino acids, monosodium glutamate, and inositol. We monitored growth, cell number, and cell size to ensure that the optimisation was towards a greater density of cells rather than just towards an increase in biomass (i.e., larger cells). Cells grown in the final medium, HCD, exhibit growth more similar to the complex medium yeast extract peptone dextrose (YPD) than to the synthetic defined (SD) medium. Whereas the final cell density of HCD prior to the diauxic shift is increased compared with YPD and SD about threefold and tenfold, respectively. We found normal cell-cycle behaviour throughout the growth phases by monitoring DNA content and protein expression using fluorescent reporters. We also ensured that HCD media could be used with a variety of strains and that they allow selection for all common yeast auxotrophic markers.
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Affiliation(s)
- Tania Michelle Roberts
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstr. 26, Basel, 4058, Switzerland
| | - Hans-Michael Kaltenbach
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstr. 26, Basel, 4058, Switzerland.,SIB Swiss Institute of Bioinformatics, ETH Zurich, Basel, Switzerland
| | - Fabian Rudolf
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstr. 26, Basel, 4058, Switzerland.,SIB Swiss Institute of Bioinformatics, ETH Zurich, Basel, Switzerland
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14
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Eze EC, El Zowalaty ME. Combined Effects Of Low Incubation Temperature, Minimal Growth Medium, And Low Hydrodynamics Optimize Acinetobacter baumannii Biofilm Formation. Infect Drug Resist 2019; 12:3523-3536. [PMID: 31814741 PMCID: PMC6863185 DOI: 10.2147/idr.s203919] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Accepted: 06/19/2019] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Biofilm formation is an important virulence factor expressed by Acinetobacter baumannii. It shields and protects microbial cells from host immune responses, antibiotics, and other anti-infectives. Its effects on Acinetobacter baumannii infection treatments notwithstanding, important environmental factors that influence its formation have not been fully investigated. METHODS Biofilm formation was assessed using the qualitative modified Congo red assay and quantitative microtiter plate methods. The combined effect of temperature, medium and shear force was determined by measuring adherence (OD570 nm) in microtiter plate after incubation at 26°C, 30°C, and 37°C when biofilm-grown cells were cultured in the presence of minimal nutrient medium (EAOB) and nutrient-rich medium (TSB) without or with agitation at 50 rpm. Antibiotics susceptibility of meropenem, imipenem, and ciprofloxacin were tested with Kirby-Bauer disc method. P<0.05 was considered statistically significant in all the tests. RESULTS A noticeable variation in adherence was observed among the isolates cultured with both media. Biofilm forming capacity of the isolates range from 0.09-0.33. The majority of the isolates had their relative biofilm-forming capacity significantly (p<0.05) higher than the positive control, Acinetobacter baumannii ATCC 19606. The biofilm biomass during growth in nutrient-rich medium (TSB) without shaking was significantly different (p<0.05; Tukey's test) among the three temperatures tested compared with when it was cultured in EAOB without shaking. A positive correlation was observed between biofilm formation and resistance to imipenem (r=0.2889; p=0.05). There was a statistically significant difference among the median of the three source groups (p<0.05) compared with the median between the source groups. CONCLUSION This observation extended further the view that A. baumannii biofilm formation is enhanced when nutrient-poor medium is used at room temperature (26°C) with or without agitation compared to growth at 37°C.
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Affiliation(s)
- Emmanuel C Eze
- Medical Microbiology and Infection Control, School of Laboratory Medicine and Medical Sciences, College of Health Science, University of KwaZulu-Natal, Durban, South Africa
| | - Mohamed E El Zowalaty
- Virology and Microbiology Research Group, School of Health Sciences, University of KwaZulu-Natal, Durban4000, South Africa
- Infectious Diseases and Anti-Infective Research Group, College of Pharmacy, University of Sharjah, Sharjah27272, UAE
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15
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Novitskaya IV, Zhoga LK, Tereshko DL. Modification of the Francis Medium for the Conversion of Histoplasma capsulatum to the Yeast-Like Growth Phase. Bull Exp Biol Med 2019; 167:62-64. [PMID: 31177444 DOI: 10.1007/s10517-019-04461-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Indexed: 10/26/2022]
Abstract
We propose a modification of Francis agar used for identification of the causative agent of histoplasmosis by in vitro conversion of the mycelial culture to the yeast-like growth phase. For improving of the growth characteristics of the medium, we used FT-agar with glucose-vitamin additives developed for culturing of the tularemia causative agent. The modified Francis medium is characterized by significantly higher growth properties and allowed 10-fold increasing the number of CFU of yeast-like cells of both American and African histoplasmosis causative agent.
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Affiliation(s)
- I V Novitskaya
- Volgograd Research Antiplague Institute, Federal Service for Surveillance on Consumer Rights Protection and Human Well-Being, Volgograd, Russia.
| | - L K Zhoga
- Volgograd Research Antiplague Institute, Federal Service for Surveillance on Consumer Rights Protection and Human Well-Being, Volgograd, Russia
| | - D L Tereshko
- Volgograd Research Antiplague Institute, Federal Service for Surveillance on Consumer Rights Protection and Human Well-Being, Volgograd, Russia
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16
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Abstract
In this article, we provide information about culture media, including minimal liquid media, rich liquid media, solid media, top agar, and stab agar. We also provide descriptions and useful information about tools used with growth media such as inoculating loops, sterile toothpicks, and spreaders. © 2018 by John Wiley & Sons, Inc.
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Affiliation(s)
| | - Roger Brent
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington
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17
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Govaert M, Smet C, Baka M, Janssens T, Impe JV. Influence of incubation conditions on the formation of model biofilms by Listeria monocytogenes and Salmonella Typhimurium on abiotic surfaces. J Appl Microbiol 2018; 125:1890-1900. [PMID: 30117654 DOI: 10.1111/jam.14071] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 07/10/2018] [Accepted: 08/14/2018] [Indexed: 01/12/2023]
Abstract
AIMS This research aims to develop strongly adherent and mature model biofilms (on a 20 cm² polystyrene surface) for two pathogenic species, i.e. Listeria monocytogenes and Salmonella Typhimurium. These model biofilms can be used as standards to study biofilms or to study/compare the influence of different inactivation technologies. METHODS AND RESULTS Three influencing factors on the formation of biofilms are investigated, i.e. growth medium, incubation temperature and incubation time, which are three easily controllable environmental factors. Optical density measurement and plate counts were used to evaluate the adherence and the maturity of the biofilms, respectively. Confocal laser scanning microscopy was used to verify most important findings obtained with previously mentioned assays. Results indicated that mature and strongly adherent L. monocytogenes biofilms are obtained following 13 h of incubation at 30°C with BHI as growth medium. For S. Typhimurium, an incubation period of 19 h at 25°C was required with 20-fold diluted TSB as growth medium. CONCLUSIONS Based on previously mentioned assays, a protocol for the formation of reproducible model biofilms was obtained. SIGNIFICANCE AND IMPACT OF THE STUDY The developed model biofilms can be applied as a standard to study biofilms (in different research fields) and their subsequent inactivation by different methods. In addition, the results of this study could be used to control biofilm formation (e.g. by setting a maximum allowed surface temperature).
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Affiliation(s)
- M Govaert
- CPMF2 - Flemish Cluster Predictive Microbiology in Foods, Ghent, Belgium
- OPTEC - Optimization in Engineering Center-of-Excellence, KU Leuven, Belgium
- BioTeC - Chemical and Biochemical Process Technology and Control, Department of Chemical Engineering, KU Leuven, Ghent, Belgium
| | - C Smet
- CPMF2 - Flemish Cluster Predictive Microbiology in Foods, Ghent, Belgium
- OPTEC - Optimization in Engineering Center-of-Excellence, KU Leuven, Belgium
- BioTeC - Chemical and Biochemical Process Technology and Control, Department of Chemical Engineering, KU Leuven, Ghent, Belgium
| | - M Baka
- CPMF2 - Flemish Cluster Predictive Microbiology in Foods, Ghent, Belgium
- OPTEC - Optimization in Engineering Center-of-Excellence, KU Leuven, Belgium
- BioTeC - Chemical and Biochemical Process Technology and Control, Department of Chemical Engineering, KU Leuven, Ghent, Belgium
| | - T Janssens
- BioTeC - Chemical and Biochemical Process Technology and Control, Department of Chemical Engineering, KU Leuven, Ghent, Belgium
| | - J Van Impe
- CPMF2 - Flemish Cluster Predictive Microbiology in Foods, Ghent, Belgium
- OPTEC - Optimization in Engineering Center-of-Excellence, KU Leuven, Belgium
- BioTeC - Chemical and Biochemical Process Technology and Control, Department of Chemical Engineering, KU Leuven, Ghent, Belgium
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18
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Knöppel A, Knopp M, Albrecht LM, Lundin E, Lustig U, Näsvall J, Andersson DI. Genetic Adaptation to Growth Under Laboratory Conditions in Escherichia coli and Salmonella enterica. Front Microbiol 2018; 9:756. [PMID: 29755424 PMCID: PMC5933015 DOI: 10.3389/fmicb.2018.00756] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 04/04/2018] [Indexed: 11/16/2022] Open
Abstract
Experimental evolution under controlled laboratory conditions is becoming increasingly important to address various evolutionary questions, including, for example, the dynamics and mechanisms of genetic adaptation to different growth and stress conditions. In such experiments, mutations typically appear that increase the fitness under the conditions tested (medium adaptation), but that are not necessarily of interest for the specific research question. Here, we have identified mutations that appeared during serial passage of E. coli and S. enterica in four different and commonly used laboratory media and measured the relative competitive fitness and maximum growth rate of 111 genetically re-constituted strains, carrying different single and multiple mutations. Little overlap was found between the mutations that were selected in the two species and the different media, implying that adaptation occurs via different genetic pathways. Furthermore, we show that commonly occurring adaptive mutations can generate undesired genetic variation in a population and reduce the accuracy of competition experiments. However, by introducing media adaptation mutations with large effects into the parental strain that was used for the evolution experiment, the variation (standard deviation) was decreased 10-fold, and it was possible to measure fitness differences between two competitors as small as |s| < 0.001.
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Affiliation(s)
- Anna Knöppel
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Michael Knopp
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Lisa M Albrecht
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Erik Lundin
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Ulrika Lustig
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Joakim Näsvall
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Dan I Andersson
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
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Dhakal D, Chung NT, Rayamajhi V, Sohng JK. Actinomadura Species: Laboratory Maintenance and Ribosome Engineering. ACTA ACUST UNITED AC 2017; 44:10G.1.1-10G.1.12. [PMID: 28166386 DOI: 10.1002/cpmc.22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Actinomadura spp. are aerobic, Gram-positive, catalase-positive, non-acid fast, non-motile actinomycetes. Some species of Actinomadura are associated with opportunistic infections in humans. However, many bioactive compounds with pharmaceutical applications can be isolated from various Actinomadura spp. This unit includes general protocols for the laboratory maintenance of Actinomadura spp., including growth in liquid medium, growth on solid agar, long-term storage, and generation of a higher producing strain by ribosome engineering. Actinomadura hibisca P157-2 is used as a prototype for explaining the considerations for efficient laboratory maintenance of Actinomadura spp. © 2017 by John Wiley & Sons, Inc.
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Affiliation(s)
- Dipesh Dhakal
- Department of Life Science and Biochemical Engineering, Sun Moon University, Asan-si, Republic of Korea
| | - Nguyen Thanh Chung
- Department of Life Science and Biochemical Engineering, Sun Moon University, Asan-si, Republic of Korea
| | - Vijay Rayamajhi
- Department of Life Science and Biochemical Engineering, Sun Moon University, Asan-si, Republic of Korea
| | - Jae Kyung Sohng
- Department of Life Science and Biochemical Engineering, Sun Moon University, Asan-si, Republic of Korea.,Department of BT-Convergent Pharmaceutical Engineering, Sun Moon University, Asan-si, Republic of Korea
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20
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Nam HS, Yang HJ, Oh BJ, Anderson AJ, Kim YC. Biological Control Potential of Bacillus amyloliquefaciens KB3 Isolated from the Feces of Allomyrina dichotoma Larvae. Plant Pathol J 2016; 32:273-80. [PMID: 27298603 PMCID: PMC4892824 DOI: 10.5423/ppj.nt.12.2015.0274] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Revised: 02/16/2016] [Accepted: 02/20/2016] [Indexed: 05/23/2023]
Abstract
Most biocontrol agents for plant diseases have been isolated from sources such as soils and plants. As an alternative source, we examined the feces of tertiary larvae of the herbivorous rhino beetle, Allomyrina dichotoma for presence of biocontrol-active microbes. The initial screen was performed to detect antifungal activity against two common fungal plant pathogens. The strain with strongest antifungal activity was identified as Bacillus amyloliquefaciens KB3. The inhibitory activity of this strain correlated with lipopeptide productions, including iturin A and surfactin. Production of these surfactants in the KB3 isolate varied with the culture phase and growth medium used. In planta biocontrol activities of cell-free culture filtrates of KB3 were similar to those of the commercial biocontrol agent, B. subtilis QST-713. These results support the presence of microbes with the potential to inhibit fungal growth, such as plant pathogens, in diverse ecological niches.
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Affiliation(s)
- Hyo-Song Nam
- Jeonnam Bioindustry Foundation, BioControl Research Center, Gokseong 57510,
Korea
| | - Hyun-Ju Yang
- Jeonnam Bioindustry Foundation, BioControl Research Center, Gokseong 57510,
Korea
| | - Byung Jun Oh
- Jeonnam Bioindustry Foundation, BioControl Research Center, Gokseong 57510,
Korea
| | - Anne J. Anderson
- Department of Biology, Utah State University, Logan, UT 843220-5305,
USA
| | - Young Cheol Kim
- Institute of Environmentally-Friendly Agriculture, Jeonnam National University, Gwangju 61186,
Korea
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21
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Ostacolo C, Ambrosino P, Russo R, Lo Monte M, Soldovieri MV, Laneri S, Sacchi A, Vistoli G, Taglialatela M, Calignano A. Isoxazole derivatives as potent transient receptor potential melastatin type 8 (TRPM8) agonists. Eur J Med Chem 2013; 69:659-69. [PMID: 24095758 DOI: 10.1016/j.ejmech.2013.08.056] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Revised: 08/20/2013] [Accepted: 08/25/2013] [Indexed: 11/22/2022]
Abstract
Modulation of the transient receptor potential melastatin type-8 (TRPM8), the receptor for menthol acting as the major sensor for peripheral innocuous cool temperatures, has several important applications in pharmaceutical, food and cosmetic industries. In the present study, we designed 12 isoxazole derivatives and tested their pharmacological properties both in F11 sensory neurons in vitro, and in an in vivo model of cold allodynia. In F11 sensory neurons, single-cell Ca(2+)-imaging experiments revealed that, when compared to menthol, some newly-synthesized compounds were up to 200-fold more potent, though none of them showed an increased efficacy. Some isoxazole derivatives potentiated allodynic responses elicited by acetone when administered to rats subjected to sciatic nerve ligation; when compared to menthol, these compounds were efficacious at earlier (0-2 min) but not later (7-9 or 14-16 min) time points. Docking experiments performed in a human TRPM8 receptor model revealed that newly-synthesized compounds might adopt two possible conformations, thereby allowing to distinguish "menthol-like" compounds (characterized by high efficacy/low potency), and "icillin-like" compounds (with high potency/low efficacy). Collectively, these data provide rationale structure-activity relationships for isoxazole derivatives acting as TRPM8 agonists, and suggest their potential usefulness for cold-evoked analgesia.
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22
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Nyenje ME, Green E, Ndip RN. Evaluation of the effect of different growth media and temperature on the suitability of biofilm formation by Enterobacter cloacae strains isolated from food samples in South Africa. Molecules 2013; 18:9582-93. [PMID: 23966079 PMCID: PMC6270404 DOI: 10.3390/molecules18089582] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 07/22/2013] [Accepted: 07/23/2013] [Indexed: 12/12/2022] Open
Abstract
This study evaluated the effects of growth medium, temperature, and incubation time on biofilm formation by Enterobacter cloacae strains. The ability to adhere to a surface was demonstrated using a microtiter plate adherence assay whereas the role of cell surface properties in biofilm formation was assessed using the coaggregation and autoaggregation assays. The architecture of the biofilms was examined under scanning electron microscope (SEM). All the strains adhered to the well of the microtiter plate when incubated for 48 h, irrespective of the growth medium and incubation temperature. It was also noted that 90% and 73% of strains prepared from nutrient broth and cultured in brain heart infusion (BHI) broth and tryptic soy broth (TSB), respectively, were able to form biofilms, in contrast to 73% and 60% strains from nutrient agar and cultured in BHI and TSB respectively grown under similar conditions. However, no statistically significant difference was observed when the two methods were compared. The coaggregation index ranged from 12% to 74%, with the best coaggregate activity observed when partnered with Streptococcus pyogenes (54%-74%). The study indicates the suitability of BHI and TSB medium for the cultivation of E. cloacae biofilms, however, temperature and incubation time significantly affect biofilm formation by these bacteria.
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Affiliation(s)
- Mirriam E. Nyenje
- Department of Biochemistry and Microbiology, Faculty of Science and Agriculture, University of Fort Hare, PMB X1314, Alice 5700, South Africa; E-Mails: (M.E.N.); (E.G.)
| | - Ezekiel Green
- Department of Biochemistry and Microbiology, Faculty of Science and Agriculture, University of Fort Hare, PMB X1314, Alice 5700, South Africa; E-Mails: (M.E.N.); (E.G.)
| | - Roland N. Ndip
- Department of Biochemistry and Microbiology, Faculty of Science and Agriculture, University of Fort Hare, PMB X1314, Alice 5700, South Africa; E-Mails: (M.E.N.); (E.G.)
- Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Box 63, Buea, Cameroon
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