Bioluminescence Biosensor For
Pathogen Detection In Food
Why detection of micro
organisms in food is important?
“2.2 million people die annually due to food
and water borne illnesses, and 1.9 millions
among them are children” -WHO
Conventional methods used for this are
microbiological and biochemical analysis,
ELISA, PCR etc.
They are overly time consuming, not
amendable to on site detection and need a
Biosensors have been identified as attractive
alternatives to the existing conventional
pathogen detection methods.
What is a Biosensor?
A biosensor is an analytical device, used
for the detection of an analyte, that
combines a biological component with a
History of Bioluminescence
In 1667 Robert Boyle, English chemist
He observed few spot of bluish-green light on
a chicken carcasses which was purchased
the week prior.
Dubois confirmed oxygen dependency and
demonstrated the necessity of an enzyme
(luciferase) and a luciferase substrate for
Need luciferase enzyme.
Substrate is catalytic oxidated by the
enzyme to produce light in the
presence of molecular oxygen.
FMNH2 + RCHO + O2 FMN + RCOOH + H2O
Bioluminescence in a
Luciferase can be found in bacteria (
lux ) and eukaryotes ( luc ).
It’s encoded by lux A and B genes.
In addition light generation requires
lux C,D and E genes.
How to use a Bacteriophage?
Select a specific
Change the DNA
Introduce to the medium
phage with lux
Inject lux gene
A511::lux AB recombinant phage is used
to identify Listeria bacterium in Spikked
ricotta cheese, chocolate pudding etc.
A511::lux AB is used to check the quality
of minced meat and soft cheese.
P22::lux AB is used to identify
( ex:- in eggs )
Advantages of bacteriophage
Less time consuming
Minimal sample preparation.
Specificity of detection
can distinguish between live and
dead MO s.
Presence of specific phage inhibition.
Antiviral bacterial immunity system.