Biotechnology for Sustainability: Achievements, Challenges and Perspectives

Biotech Sustainability (2017)
Sensing Technology for Shrimp Aquaculture Sustainability
Kandasamy et al.
Figure 3: Mode of action of AHL lactonase and AHL acylase.
and seaweeds (Kim et al., 2007; Skindersoe
et al., 2008; Daglia et al., 2010;
Musthafa et al., 2010).
The QS interference from novel
sources may also be an important as the
antibacterial effects. Anti-QS agents were
first characterized in the red marine alga
D. pulchura (Manefield et al., 1999).
This alga was investigated for its antifouling
properties and was found to contain
halogenated furanones which block
AHLs via competitive inhibition and destabilization
of LuxR (Manefield et al.,
2002). Delisea furanones have been
shown to reduce light emission in Vibrio
species (Givskov et al., 1996), inhibit
pigment production in C. violaceum
(Martinelli et al., 2004) and attenuate exoenzyme
production and swarming motility
in Serratia liquefaciens (Rasmussen et al.,
2000). The quorum sensing-disrupting
natural furanone, (5Z)-4-bromo-5-
(bromomethylene)-3-butyl-2(5H)-
furanone was found to block autoinducer
2 quorum-sensing in V. harveyi in a concentration-dependent
way (Defoirdt et al.,
2006). Persson et al., (2005) reported that
toluene extracts of garlic contained several
compounds with varying levels of QSI
against Gram-negative transcriptional regulators
Lux R or Lux R. Sergey et al.,
(2011) have evaluated 78 natural products
from chemical libraries containing compounds
from marine organisms (Sponges,
algae, fungi and cyanobacteria) and terrestrial
plants were screened for the inhibition
of bacterial QS using a reporter strain
C. violaceum CV017. Various fruits and
herbs were shown to possess anti-QS activity
in a C. violaceum biomonitor strain
and on the swarming motility of E. coli
and P. aeruginosa (Vattem et al., 2007).
The subsequent discovery of compounds
that inhibit cell-to-cell communication,
dubbed anti-quorum sensing (anti-
QS) agents could provide a novel method
of combating infection. It is possible that
several terrestrial plants also produce
quorum signal mimics capable of controlling
bacterial quorum sensing (Gao et al.,
2003). Even bacteria themselves produce
QSI substances (Nithya et al., 2010).
Spices such as garlic, ginger and turmeric
have been reported for their QSI potential
(Vattem et al., 2007). Similarly, the essential
oils of cinnamon (Niu et al., 2006) and
clove (Khan et al., 2009) are also known
to possess QSI potentials. Acyl-homo serine
lactone analogs and other quorum
sensing inhibitors (QSI) have been investigated
to determine their ability to prevent
expression of quorum sensing controlled
genes. The complex of signalling
molecules (AHLs) and receptor proteins
trigger the expression of specific genes
responsible for bioluminescence in V.
harveyi (LuxM/N). Hence the disintegration
of signals with receptor by plant derived
QSI prevents the bioluminescence
and other virulence factors in V. harveyi.
Several compounds have been identified
that have the ability to interfere with QSmediated
gene expression through com-
ISBN: 978-967-14475-3-6; eISBN: 978-967-14475-2-9 352