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Determination of DnaK dose and its stability on shrimp pellets stored at
different temperatures
Lam Mun Jing
Supervisor: Assoc. Prof Dr Yeong Yik Sung
Bachelor of Science in Agrotechnology (Aquaculture)
School of Fisheries and Aquaculture Sciences
DnaK is the bacterial heat shock protein with 70 kDa. The efficacy of DnaK in improving
shrimp immune system has been proven in many studies. Escherichia coli strains P3
and YS2 with and without overexpressed DnaK were coated on pellets at a
concentration of 10 9 cells/ml and stored at different storage conditions namely room
temperature, 4ºc and -20ºc. SDS-PAGE and western blotting were performed to
determine the band intensity (dots per inch) of DnaK blots. Densitometry analysis has
revealed that DnaK concentration of shrimp pellets in room temperature decreased
from 3878 dpi to 509 dpi whereas pellets stored in 4ºc and -20ºc dropped to 303 dpi
and 206 dpi respectively as storage time increased. The best storage condition was in
room temperature. Bacteria inactivity and cell death perhaps were the main reasons
of drastic decline. The outcome indicates that temperature may regulate DnaK
expression in bacteria cells as well as on the attachment on pellets. This can be
reviewed as a fundamental understanding to the contribution of aquaculture industry.
489 | UMT UNDERGRADUATE RESEARCH DAY 2018