scholarly journals A novel growth and isolation medium for exoelectrogenic bacteria

2022 ◽  
pp. 109995
Author(s):  
Zumaira Nazeer ◽  
Eustace Y. Fernando
Keyword(s):  
Isolation Medium ◽  
Exoelectrogenic Bacteria

scholarly journals A novel growth and isolation medium for exoelectrogenic bacteria

2021 ◽  
Author(s):  
Zumaira Nazeer ◽  
Eustace Fernando
Keyword(s):  
Growth Medium ◽  
Solid Medium ◽  
Shewanella Oneidensis ◽  
Extracellular Electron Transfer ◽  
The Novel ◽  
Isolation Medium ◽  
Biochemical Characterisation ◽  
Electrochemically Active ◽  
Colour Changes ◽  
Exoelectrogenic Bacteria

A microbiological isolation and growth medium that can effectively discriminate electrochemically active exoelectrogenic bacteria from other non-exoelectrogenic bacteria, is currently unavailable. In this study, we developed a novel chromogenic growth and isolation solid medium based on MnO2 that can selectively allow the growth of exoelectrogenic bacteria and change the medium colour in the process. Known exoelectrogenic bacteria such as Shewanella oneidensis MR1 and other such bacteria from functional microbial fuel cell (MFC) anodes were capable of growing and changing colour in the novel growth medium. On the contrary, non-exoelectrogenic bacteria such as Escherichia coli ATCC 25922 were incapable of growing and inducing a colour changes in the novel medium. Further biochemical characterisation of these isolated exoelectrogenic bacteria by Raman micro-spectroscopy demonstrated that these bacteria over express cytochrome proteins that are vital in extracellular electron transfer events. This medium is a convenient method to isolate exoelectrogenic bacteria from complex environmental samples.

Sampling bias created by ampicillin in isolation media forAeromonas

2007 ◽  
Vol 53 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Jennifer R Huddleston ◽  
John C Zak ◽  
Randall M Jeter
Keyword(s):  
Sampling Bias ◽  
Aeromonas Species ◽  
Aquatic Environments ◽  
Selective Agent ◽  
Opportunistic Pathogens ◽  
Chi Square ◽  
Isolation Medium ◽  
Ability To Act ◽  
Chi Square Analysis ◽  
The Impact

Members of the bacterial genus Aeromonas are widely isolated from aquatic environments and studied in part for their ability to act as opportunistic pathogens in a variety of animals. All aeromonads, with the exception of Aeromonas trota, are generally thought to be resistant to ampicillin, so the antibiotic is frequently added to isolation medium as a selective agent. In this study, 282 aeromonads from environmental sources were isolated on a medium without ampicillin and their resistance to ampicillin determined. Of the 104 of these isolates that were judged to be independent (nonredundant), 18 (17.3%) were susceptible to ampicillin. A chi-square analysis was performed to determine the impact of ampicillin use on enumerating Aeromonas species from environmental samples. Our results indicate that, when ampicillin is used as a selective agent, a significant portion of the aeromonad population in at least some environ ments can be omitted from isolation.Key words: Aeromonas, ampicillin, selective media.

A New Isolation Medium for Plant Organelles

1966 ◽  
Vol 17 (3) ◽  
pp. 460-472 ◽  
Author(s):  
S. I. HONDA ◽  
TASANI HONGLADAROM ◽  
G. G. LATIES
Keyword(s):  
Isolation Medium ◽  
Plant Organelles

scholarly journals HEAVY METAL-RESISTANT RHIZOBACTERIA FROM GOLD MINE IN PONGKOR INDONESIA AND COPPER MINE IN MARINDUQUE PHILIPPINES

Agric ◽  
2019 ◽  
Vol 31 (1) ◽  
pp. 75-88 ◽  
Author(s):  
Erny Yuniarti ◽  
Ida F Dalmacio ◽  
Erlinda S Paterno
Keyword(s):  
Resistance Mechanism ◽  
Morphological Characterization ◽  
Gold Mine ◽  
Isolation Medium ◽  
Mine Site ◽  
Copper Mine ◽  
Gram Staining ◽  
16S Rna ◽  
Agar Media

The purposes of the study was to isolate, to characterize, and to identify rhizobacteria from plant rhizosphere growing in gold and copper mine. The isolation of rhizobacteria used N-free semisolid agar media, TSA, and SLP plus heavy metals (HMs), namely Pb, Cd, and or Cu. Isolated rhizobacteria were subsequently characterized for resistance to higher level of Pb, Cd, Cu in SLP media. Cultural and morphological characterization of rhizobacteria were conducted for cell morphology, motility, Gram staining, and biofilm formation. The rhizobacteria identification used sequence analysis of the 16S RNA gene fragments. The results showed that the majority of rhizobacterial from Cu mine site (66.7% of 21 isolates) were resistant to Cu (72150 ppm) while the majority of rhizobacteria from gold mine site (77.8% of 18 isolates) were sensitive to 72 ppm Cu. Majority of Cu in the soil was insoluble as granules attaching to gravel so that rhizobacteria of Cu mine site have been exposed and adapted to available Cu. This fact, explaining that the rhizobacteria’s MIC value was lower than the total Cu level in the soil. Three HMs-resistant rhizobacter (PbSM 2.1, MGR 334, and CuNFbM 4.1) formed biofilms, which was as one of the resistance mechanism to HMs. This research informed that HM contaminated-soil is better source for obtaining HM resistant rhizobacteria than HM uncontaminated-soil. The use four isolation media produce rhizobacteria which was more diverse than rhizobacteria from each isolation medium. Further characterization needs to be done to obtain HM resistant-rhizobacteria which can be used as biofertilizers and phytoremediation agent.

The Concentrations of Dry Matter in Mitotic Apparatuses in Vivo and After Isolation From Sea-Urchin Zygotes

1972 ◽  
Vol 10 (2) ◽  
pp. 387-418
Author(s):  
A. FORER ◽  
R. D. GOLDMAN
Keyword(s):  
Sea Urchin ◽  
Dry Matter ◽  
Mass Medium ◽  
Dry Mass ◽  
Interference Microscopy ◽  
High Mass ◽  
Isolation Medium ◽  
High Ph ◽  
Cytoplasmic Material

We have measured the concentrations of dry matter in mitotic apparatuses (MA) in vivo and after isolation from the same cell type. The isolation medium was hexylene glycol plus buffer. The MA were from sea-urchin zygotes (Echinus esculentus Linn. and Psammechinus miliaris Gmelin), and measurements were made using interference microscopy. MA as isolated have much lower concentrations of dry matter than do MA in vivo. The dry mass concentrations of isolated MA vary with the pH of the isolation medium, ranging from about 20 % of the in vivo concentration (at pH 7.3) to about 60 % of the in vivo concentration (at pH 5.3). The isolated MA were further characterized. Evidence is presented which suggests that non-specific cytoplasmic material adsorbs to MA, and thus that at least some of the material in isolated MA is not derived from in vivo MA. Some MA components are apparently changed during the isolation procedure: MA lysed in low pH (high mass) medium and quickly transferred to high pH (low mass) medium have higher concentrations of dry matter than do MA lysed in high pH medium. The isolation media as generally used do not have enough buffering capacity: the pH changes after the isolation. These data suggest that the isolation procedures need be improved before studies of isolated MA can give data relevant to the chemistry of in vivo MA. We discuss the problem of obtaining functional isolated MA, and also the relevance of our data to previous work on MA from other species.

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