Test chemicals and media
The stock solution of arsenic and other heavy metals was prepared by
dissolving heavy metal salts (1,000 mg L−1) in Milli-Q
water and filter sterilized through 22-µm filter (Axiva). For arsenate
(V) Sodium arsenate dibasic heptahydrate
(Na2HAsO4·7H2O), and for
arsenite (III) Sodium (meta)arsenite (NaAsO2) salts were
used. Beside these, salts like Cadmium chloride (CdCl2),
cobaltous nitrate hexahydrate
(Co(NO3)2.6H2O), copper chloride
(CuCl2), potassium dichromate
(K2Cr2O7), lead nitrate
(Pb(NO3)2), nickel sulphate hexahydrate
(NiSO4.6H2O), and zinc sulphate
heptahydrate (ZnSO4.7H2O) were used to
prepared stock solution of respective heavy metal. Working test metal
solution (20 mg L−1) was prepared by diluting the
prepared concentrated stock solution. All the glasswares were acid
washed with 10% nitric acid before use to avoid binding of metals. All
the chemicals and culture media were of analytical grade and obtained
from Himedia, Merck, Sigma, and BioRad.