iBB
46.3K views | +8 today
Follow
iBB
Institute for Bioengineering and Biosciences
Curated by iBB
Your new post is loading...
Your new post is loading...
Scoop.it!

Key Parameters on the Antibacterial Activity of Silver Camphor Complexes

Key Parameters on the Antibacterial Activity of Silver Camphor Complexes | iBB | Scoop.it

A recent publication in the journal Antibiotics describes the synthesis and analytical and spectroscopical characterization of nine new complexes with camphor imine or camphor sulfonimine ligands were, aiming to identify the key parameters that drive the antibacterial activity of the complexes with metal cores and imine substituents with distinct electronic and steric characteristics. The antimicrobial activity of all complexes was evaluated by determining their minimum inhibitory concentrations (MIC) against the Gram-negative Escherichia coli ATCC25922, Pseudomonas aeruginosa 477, and Burkholderia contaminans IST408, and the Gram-positive Staphylococcus aureus Newman. All the complexes display higher activity towards Gram-negative strains than towards the Gram-positive strain. This work results from the collaborative research between the research groups of Fernanda Carvalho from CQE and Jorge H. Leitão from BSRG-IBB. The paper was selected as “Editor´s Choice”.

No comment yet.
Scoop.it!

Extreme Enhancement of Single-Molecule Fluorescence Induced by Gold Nanodimer Antennas

Extreme Enhancement of Single-Molecule Fluorescence Induced by Gold Nanodimer Antennas | iBB | Scoop.it

Porphyrins are typically weak emitters, which presents challenges to their optical detection by single-molecule fluorescence microscopy. A recent collaboration between BERG-iBB, Centro de Química Estrutural and Universidade Nova explores the enhancement effect of gold nanodimer antennas on the fluorescence of porphyrins in order to enable their single-molecule optical detection. Four meso-substituted free-base porphyrins were evaluated: two cationic, one neutral, and one anionic porphyrin. The gold nanodimer antennas are able to enhance the emission from these porphyrins by a factor of 10^5–10^6 increase in the maximum detected photon rates. This extreme enhancement is due to the combination of an antenna effect on the excitation rate that is estimated to be above 10^4-fold and an emission efficiency that corresponds to an increase of 2–10 times in the porphyrin’s fluorescence quantum yield. The work was published in the Journal of Physical Chemistry Letters, and is co-authored by David Botequim, Miguel Prazeres (BERG) and Pedro Paulo (CQE).

No comment yet.
Scoop.it!

Use of Silk Fibroin Functionalized with CuSO4 in Microwave-Assisted Knoevenagel Condensation

Use of Silk Fibroin Functionalized with CuSO4 in Microwave-Assisted Knoevenagel Condensation | iBB | Scoop.it

Conventional organic synthesis has greatly contributed to the production of a huge number of molecular precursors of essential materials in modern life. However, these methods are characterized by a strong negative impact when evaluated in terms of sustainability. In the last decade, microwave radiation techniques have been able to perform many of these organic chemistry reactions generally faster, with better yields, and according to the principles of Green Chemistry. In a paper recently published by Luis Fonseca from BERG-iBB and colleagues from university of S. Paulo, silk fibroin fibers functionalized with CuSO4 were tested as a renewable catalyst in combination with microwave radiation to assist Knoveneganel condensation reactions due to its great potential for forming carbon-carbon bonds from a wide range of compounds. Click on title to learn more.

No comment yet.
Scoop.it!

Moesziomyces antarcticus Production of MEL from Lignocellulose Hydrolysates (JCTB cover)

Moesziomyces antarcticus Production of MEL from Lignocellulose Hydrolysates (JCTB cover) | iBB | Scoop.it

Moesziomyces antarcticus is an efficient producer of mannosylerythritol lipids (MEL), a biosurfactant with a wide range of potential applications. The use of lignocellulosic biomass can contribute to sustainable MEL production. While lignocellulosic sugars (e.g. D-glucose and D-xylose) can be converted to MEL, the required pretreatment of lignocellulosic biomass releases by products that are potentially inhibitory for yeasts. A recent publication by Marisa Santos, Nuno Faria and Frederico Ferreira from BERG-iBB , in collaboration with César Fonseca from LNEG, describes a design of experiment (DoE) that was performed to evaluate the effect of furfural, acetate and formate on M. antarcticus and its capacity to produce MEL from lignocellulose hydrolysates. The study provides insight into the conditions required by M. antarcticus for MEL production from lignocellulosic hydrolysates and points towards further process and strain development requirements. The work was published in Journal of Chemical Technology and Biotechnology and made it to the cover of the journal.

 

Image details: JCTB cover,  copyright by Marisa V. Santos, 2018. Acknowledgements: FCT grant CRUISE (PTDC/AAG‐TEC/0696/2014)

No comment yet.
Scoop.it!

Purification of Plasmid DNA by Multimodal Chromatography

Purification of Plasmid DNA by Multimodal Chromatography | iBB | Scoop.it
Production of plasmid DNA is important in the context of gene therapy and DNA vaccination. In a paper just published in the journal Separation and Purification Technology, Ana Rita Santos, Cláudia Alves, Ana Azevedo and Miguel Prazeres from BERG-iBB, describe a process based on tandem precipiatation and multimodal chromatography that yields pure supercoiled plasmid DNA. The chromatography step, which uses a cationic multimodal ligand (Capto™ adhere) and an NaCl step gradient, provides baseline separation of isoforms and yields supercoiled-rich fractions (>90%) that are virtually free from RNA and have levels of gDNA and protein impurities within specifications. Click on title to learn more.
No comment yet.