scholarly journals Characterization of Arsenite-Oxidizing Bacteria Isolated from Arsenic-Rich Sediments, Atacama Desert, Chile

2021 ◽  
Vol 9 (3) ◽  
pp. 483
Author(s):  
Constanza Herrera ◽  
Ruben Moraga ◽  
Brian Bustamante ◽  
Claudia Vilo ◽  
Paulina Aguayo ◽  
...  

Arsenic (As), a semimetal toxic for humans, is commonly associated with serious health problems. The most common form of massive and chronic exposure to As is through consumption of contaminated drinking water. This study aimed to isolate an As resistant bacterial strain to characterize its ability to oxidize As (III) when immobilized in an activated carbon batch bioreactor and to evaluate its potential to be used in biological treatments to remediate As contaminated waters. The diversity of bacterial communities from sediments of the As-rich Camarones River, Atacama Desert, Chile, was evaluated by Illumina sequencing. Dominant taxonomic groups (>1%) isolated were affiliated with Proteobacteria and Firmicutes. A high As-resistant bacterium was selected (Pseudomonas migulae VC-19 strain) and the presence of aio gene in it was investigated. Arsenite detoxification activity by this bacterial strain was determined by HPLC/HG/AAS. Particularly when immobilized on activated carbon, P. migulae VC-19 showed high rates of As(III) conversion (100% oxidized after 36 h of incubation). To the best of our knowledge, this is the first report of a P. migulae arsenite oxidizing strain that is promising for biotechnological application in the treatment of arsenic contaminated waters.

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 504
Author(s):  
Yane Ansanay ◽  
Praveen Kolar ◽  
Ratna Sharma-Shivappa ◽  
Jay Cheng ◽  
Consuelo Arellano

In the present research, activated carbon-supported sulfonic acid catalysts were synthesized and tested as pretreatment agents for the conversion of switchgrass into glucose. The catalysts were synthesized by reacting sulfuric acid, methanesulfonic acid, and p-toluenesulfonic acid with activated carbon. The characterization of catalysts suggested an increase in surface acidities, while surface area and pore volumes decreased because of sulfonation. Batch experiments were performed in 125 mL serum bottles to investigate the effects of temperature (30, 60, and 90 °C), reaction time (90 and 120 min) on the yields of glucose. Enzymatic hydrolysis of pretreated switchgrass using Ctec2 yielded up to 57.13% glucose. Durability tests indicated that sulfonic solid-impregnated carbon catalysts were able to maintain activity even after three cycles. From the results obtained, the solid acid catalysts appear to serve as effective pretreatment agents and can potentially reduce the use of conventional liquid acids and bases in biomass-into-biofuel production.


Adsorption ◽  
2011 ◽  
Vol 18 (1) ◽  
pp. 23-29 ◽  
Author(s):  
Qing He ◽  
Yingbo Xu ◽  
Chenghui Wang ◽  
Shike She ◽  
Shun Zhou ◽  
...  

2020 ◽  
Author(s):  
Antonius Agus Bambang Haryanto ◽  
Ari Handono Ramelan ◽  
MTh Sri Budiastuti ◽  
Pranoto

2021 ◽  
Vol 46 ◽  
pp. 101476
Author(s):  
Azeem Sarwar ◽  
Majid Ali ◽  
Asif Hussain Khoja ◽  
Azra Nawar ◽  
Adeel Waqas ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document