Agricultural Research Management Information System

Home
Research Summary
Search
About Us
- ARMIS
- Brochure
Contact Us
Report
User Request
Data Input
Help
- Operation Manual
  - PDF
  - Video
- Program Area & Commodity
We have reached 37600 number of research entries at this moment.

- Logout

Research Detail

Home
Research
Detail

Isolation of Arsenic Oxidizing-reducing Bacteria and Reclamation of as (iii) in Vitro Condition

U A Naher
Soil Science Division, Bangladesh Rice Research Institute, Gazipur 1701, Bangladesh

F Rahman
Soil Science Division, Bangladesh Rice Research Institute, Gazipur 1701, Bangladesh

S M M Islam
Soil Science Division, Bangladesh Rice Research Institute, Gazipur 1701, Bangladesh

M I U Sarkar
Soil Science Division, Bangladesh Rice Research Institute, Gazipur 1701, Bangladesh

J C Biswas
Soil Science Division, Bangladesh Rice Research Institute, Gazipur 1701, Bangladesh

Abstract/ Executive Summary:

The study aimed to isolate arsenic (As) oxidizing-reducing bacteria from As contaminated soil and water and to determine their ability to remove As from broth culture. Soil and water samples were collected from As contaminated area of BRRI farm, Bhanga, Faridpur. Arsenic oxidizing and reducing bacteria were isolated from the As contaminated soil (13 mg kg-1) and water (410 µg/L) using spread plate count method in minimal salt (MS) medium after seven days of incubation. The oxidation activity of the bacteria as well as reclamation of As [III] was determined from NaAsO₂ supplemented broth using atomic absorption spectrophotometer (AAS). The As-oxidizing bacteria population was present only in one soil sample, while in all water samples both oxidizing and reducing bacteria were present. A total of 36 As oxidizing-reducing bacteria were isolated. As-oxidizing bacteria removed 71-99% of applied As [III] in broth culture. Two out of 10 As-oxidizing bacterial strains appeared more efficient than others to remove As [III] under broth culture conditions.

Keywords: Arsenic oxidizing-reducing bacteria; Isolation; Reclamation

Location: BRRI farm, Bhanga, Faridpur.

Start Date:

End Date:

Program Area: Risk Management in Agriculture

Commodity: Arsenic

Objectives:

The study aimed to isolate arsenic (As) oxidizing-reducing bacteria from As contaminated soil and water and to determine their ability to remove As from broth culture.

Methodology:

Arsenic contaminated soil and water samples were collected from Bhanga area of Faridpur district, Bangladesh. Soil samples were preserved in plastic containers and refrigerated until further analysis. Soil used was classified as inceptisol and initial chemical properties were: pH 7.3 (in 1:2.5 water), organic carbon 1.7%, total N 0.17%, available P 9 mg kg-1, exchangeable K 0.56 cmol kg-1, available S 29 mg kg -1, and available Zn 0.9 mg kg-1. The soil contained 13 mg As per kg. The isolation was done within seven days after sample collection. One gram of soil samples were taken into 95 ml sterile distilled water and a series of 10 fold dilutions were made up to 10. Verification of the transforming ability of the isolate was carried out by using of AgNO₃ method.MS media containing 5mM Na-lactate as carbon source and 5mM Na-arsenate as the electron acceptor were used to determine the ability of isolates to reduce As [V]. Bacteria were grown under anaerobic conditions and after seven days of incubation at 28°C, the agar plats were immersed with 0.1 M AgNO₃ solution. Reaction of AgNO₃ with As [V] or As [III] resulted a coloured precipitate (Simeonova et al., 2004). A brownish precipitate indicates the presence of Ag₃AsO₄ (silver arsenate) in the medium while, a yellow precipitate reveals the presence of AgAsO₃ (silver arsenite). The oxidation activity of the bacteria as well as reclamation of As [III] was determined from NaAsO₂ supplemented broth. Exactly, 7000 ppb of NaAsO₂ was added to 50 ml of minimal salt broth. After seven days of incubation As [III] was determined using atomic absorption spectrophotometer (AAS) with flow-injection hydride generation system (Model: A Analyst 100 Atomic Absorption Spectrometer, Perkin Elmer).

Source of Information: Bangladesh Rice J. 19(2): 99-101, 2015

Article Link (Online Journal):

Funding Source:

Budget:

Total Budget (Tk.) :

Achievement/Findings:

Arsenic oxidizing and reducing bacteria were isolated from the As contaminated soil (13 mg kg^-1) and water (410 µg/L) using spread plate count method in minimal salt (MS) medium after seven days of incubation. The oxidation activity of the bacteria as well as reclamation of As [III] was determined from NaAsO₂ supplemented broth using atomic absorption spectrophotometer (AAS). The As-oxidizing bacteria population was present only in one soil sample, while in all water samples both oxidizing and reducing bacteria were present. A total of 36 As oxidizing-reducing bacteria were isolated. As-oxidizing bacteria removed 71-99% of applied As [III] in broth culture. Two out of 10 As-oxidizing bacterial strains appeared more efficient than others to remove As [III] under broth culture conditions.

Knowledge Management: Journal