scholarly journals Identification of mercury‐resistant Streptomyces isolated from Cyperus rotundus L. rhizosphere and molecular cloning of mercury (II) reductase gene

2021 ◽  
Vol 26 (4) ◽  
pp. 206
Author(s):  
Wahyu Aristyaning Putri ◽  
Hanum Mukti Rahayu ◽  
Anis Uswatun Khasanah ◽  
Langkah Sembiring ◽  
Masashi Kawaichi ◽  
...  
Keyword(s):  
Gold Mining ◽  
Full Length ◽  
Cyperus Rotundus ◽  
Cloning And Expression ◽  
Expression Vectors ◽  
Resistant Bacteria ◽  
Small Scale ◽  
Rrna Gene ◽  
Reductase Gene ◽  
Mera Gene

Streptomyces is one of mercury‐resistant bacteria which can convert Hg2+ into nontoxic Hg0 . This study aimed to identify mercury‐resistant Streptomyces present in the Cyperus rotundus rhizosphere from artisanal small‐scale gold mining (ASGM) area and clone merA gene to the cloning and expression vectors. Molecular identification was conducted using 16s rRNA gene with the maximum likelihood algorithms. Results revealed that the AS1 and AS2 strains were a group of Streptomyces ardesiacus and the BR28 strain was closed to Brevibacillus agri. The AS2 merA gene was cloned to pMD20 cloning vectors, pGEX‐5x‐1 and pET‐28c expression vectors. The transformation was successfully performed in BL21 and DH5α competent cells. The full length of the merA gene was confirmed to be 1,425 bp. This study is the first research on identifying mercury‐resistant Streptomyces and cloning the full‐length merA gene in Indonesia.

scholarly journals Indigenous mercury-resistant bacteria isolated from contaminated soils around artisanal gold processing centers in Sukabumi, Indonesia

2021 ◽  
Vol 909 (1) ◽  
pp. 012009
Author(s):  
F Y Amandita ◽  
Efadeswarni ◽  
Idris ◽  
T Sulistiyani ◽  
A Kanti ◽  
...  
Keyword(s):  
Contaminated Soils ◽  
Gold Mining ◽  
Agricultural Land ◽  
Normal Growth ◽  
Luria Bertani ◽  
Mercury Pollution ◽  
Resistant Bacteria ◽  
Small Scale ◽  
Lag Phase ◽  
Gold Processing

Abstract In Indonesia, the largest mercury pollution comes from artisanal and small-scale gold mining (ASGM), which may cause the distribution of mercury to agricultural land and can be absorbed by food crops. Sukabumi Regency in West Java, well-known as one hotspot of illegal artisanal gold mining and national rice producer, is potentially threatened by mercury pollution. Efforts to remediate mercury contaminated agricultural land can be done by using mercury-reducing bacteria. This research aims to select the most potential indigenous bacteria for mercury remediation. Soil and sludge samples were collected from 2 districts in Sukabumi, where gold processing using mercury is common. Bacteria were selectively isolated from cultured colonies grown in Luria Bertani broth supplemented with HgCl2 30 mg/L. We obtained 27 isolates that belong to 16 species, as identified by API® 20 E and 20 NE (BioMérieux, USA). The growth of each isolate was assessed by measuring the optical density of inoculated LB broth contained HgCl2 30 mg/L for 5 consecutive days. All isolates showed normal growth. The log phase reached its maximum value on the second or third day after inoculation and lag phase afterward. Twelve identified isolates were chosen for evaluation of their resistance to mercury by growing them in Mueller-Hinton agar supplemented with HgCl2 (30 mg/L, 50 mg/L, 100 mg/L, 150 mg/L, and 200 mg/L). Seven isolates were able to grow in media with HgCl2, but only Mer07 survived on HgCl2 150 mg/L.

MERCURY AND SMALL-SCALE GOLD MINING AT ANCIENT SARDIS, TURKEY

2016 ◽  
Author(s):  
William E. Brooks ◽  
◽  
Huseyin Ozturk ◽  
Zeynep Cansu Oru
Keyword(s):  
Gold Mining ◽  
Small Scale

scholarly journals The outbreak of illegal gold mining in the Brazilian Amazon boosts deforestation

2021 ◽  
Vol 21 (2) ◽  
Author(s):  
Juliana Siqueira-Gay ◽  
Luis E. Sánchez
Keyword(s):  
Gold Mining ◽  
Brazilian Amazon ◽  
Small Scale ◽  
Political Pressure ◽  
Deforestation Rate ◽  
Mining Areas ◽  
Mineral Supply ◽  
Regional Policies ◽  
Illegal Mining ◽  
Conservation Of Biodiversity

AbstractIncreased prices and political pressure are boosting illegal gold mining in the Brazilian Amazon, threatening forests, indigenous people, and conservation of biodiversity in protected areas. The rate of illegal mining deforestation increased more than 90% from 2017 to 2020, reaching 101.7 km2 annually in 2020 compared to 52.9 km2 annually in 2017. In that period, illegal mining deforestation rate grew more than the rate of clearing within mining leases. While formal mining is required to comply with environmental regulations, most small-scale or artisanal mining and especially illegal mining areas are abandoned after reserves are exhausted, without proper rehabilitation. Deforestation due to illegal mining is likely to increase in the next years, calling for coordination between local and regional policies as well as for strengthening and expanding international mechanisms to increase traceability of mineral supply chains with certification schemes to help to curb illegal mining.

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