Quorum sensing control for microbial management of the aquaculture food chain rotifers

217 Pages·2008·1.26 MB·English

TABLE OF CONTENTS

List of Abbreviations iii
List of Tables vi
List of Figures viii
Chapter 1 Introduction 1
1.1 Importance of aquaculture 2
1.2 Situation of fish larviculture 4
1.2.1 Overview 4
1.2.2 Larviculture in Europe 5
1.2.3 Larviculture in Japan 7
1.2.4 Larviculture in Taiwan 7
1.2.5 Larviculture in Southeast Asia 8
1.2.6 Role of live food in marine larviculture 9
1.3 Turbot larviculture 14
1.3.1 Status of European production 14
1.3.2 Larviculture techniques 15
1.3.3 Critical aspects of turbot larviculture 16
1.4 Microbial management in larviculture 18
1.4.1 Fish-bacteria interactions in larviculture 18
1.4.2 Techniques for microbial control in larviculture 26
1.5 Disruption of quorum sensing – a new strategy for microbial control 36
1.5.1 Quorum sensing – a means of bacterial communication 36
1.5.2 Disruption of quorum sensing 39
1.5.3 Limitations to manipulation of quorum sensing 42
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1.6 Thesis outline 42
Chapter 2 What do we know about the functionality of probiotics in larviculture
food chain? 58
Chapter 3 Gnotobiotically grown rotifer Brachionus plicatilis as a tool for
evaluation of microbial functions and nutritional value of different
food types 85
Chapter 4 Interference with the quorum sensing systems in a Vibrio harveyi
strain alters the growth rate of gnotobiotically cultured rotifer
Brachionus plicatilis 113
Chapter 5 N-acyl homoserine lactone degrading microbial enrichment cultures
isolated from Penaeus vannamei shrimp gut and their probiotic
properties in Brachionus plicatilis cultures 136
Chapter 6 An N-acyl homoserine lactone-degrading microbial community
improves the survival of first-feeding turbot larvae (Scophthalmus
maximus L.) 166
Chapter 7 Discussion and conclusions 187
Summary / Samenvatting 203
Curriculum Vitae 212

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LIST OF ABBREVIATIONS

AFDW Ash-free dry weight
AFLP Amplified fragment length polymorphism
AHL Acyl homoserine lactone
AI-2 Autoinducer 2
ANOVA Analysis of variance
ARC Artemia Reference Center
BAB Benzyldimethyldodecyl-ammonium bromide
BLAST Basic local alignment search tool
CAI-1 Cholerae autoinducer 1
CCAP Culture Collection of Algae and Protozoa
cDNA Complementary deoxyribonucleic acid
CFU Colony forming unit
CIAD Centro de Investigación en Alimentación y Desarrollo
DGGE Denaturing gradient gel electrophoresis
DHA Docosahexaenoic acid
EC Enrichment culture
ELISA Enzyme-linked immunosorbent assay
EPA Eicosapentaenoic acid
EUROSCARF European Saccharomyces cerevisiae Archive for Functional Analysis
FAO Food and Agriculture Organization
FASW Filtered and autoclaved seawater
FISH Fluorescent in situ hybridization
GenBank Genetic sequence database of the National Institute of Health, USA
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GFP Green fluorescent protein
GI Gastrointestinal
GR Growth-retarding
HAI-1 Harveyi autoinducer 1
HHL Hexanoyl homoserine lactone
HUFA Highly unsaturated fatty acid
ICB Immunocolony blot
LB Luria-Bertani
LMG Laboratory of Microbiology of the Ghent University
LPS Lipopolysaccharide
MA Marine Agar
MB Marine Broth
MC Microbial community
MCR Microbial community regrown
MOA Mechanism of action
NCBI National Center for Biotechnology Information
NOEC Non-observable effect concentration
NSS Nine Salt Solution
OD Optical density
PCR Polymerase chain reaction
PG Peptidoglycan
QAC Quaternary ammonium compound
QS Quorum sensing
RAC Residual AHL concentration
RAPD Random amplification of polymorphic DNA
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RLLI Relative log luminescence intensity
RLU Relative light unit
rpm Rotation per minute
RR Rifampicin resistant
rRNA Ribosomal ribonucleic acid
RS Rifampicin sensitive
SD Standard deviation
TCBS Agar Thiosulfate Citrate Bile Salt Sucrose Agar
T-RFLP Terminal restriction fragment length polymorphism
TRO Total residual oxidants
TRP Technical Rubber Product
VH Vibrio harveyi
WT Wild-type
YEPD Yeast Extract Peptone Dextrose
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LIST OF TABLES

Table 1.1 Major bacterial groups isolated from the intestinal microbiota of marine
fish species 22
Table 1.2 The three elements in the strategy to achieve microbial control in the
rearing of marine fish larvae 27
Table 3.1 Concentrations and exposure times of two disinfectants used for rotifer
amictic eggs disinfection 91
Table 3.2 Outline of the experiments on the effect of microbial communities 93
Table 3.3 Effectiveness of BAB as a disinfectant for rotifer amictic eggs 95
Table 3.4 Effectiveness of glutaraldehyde as a disinfectant for rotifer amictic eggs 96
Table 3.5 Growth rate over 5 days of Brachionus plicatilis hatched from disinfected
amictic eggs and fed three types of food: effect of food type 97
Table 3.6 Interaction between food type and bacterial treatment on Brachionus
plicatilis growth rate over 5 days 101
Table 4.1 Vibrio harveyi strains used in this study 119
Table 4.2 Growth rate of Brachionus plicatilis over 72 h: effect of challenge with
Vibrio harveyi strains 121
Table 4.3 Growth rate of Brachionus plicatilis over 72 h: effect of challenge with
Vibrio harveyi strains 121
Table 4.4 Growth rate of Brachionus plicatilis over 72 h: effect of challenge with
Vibrio harveyi mutants 122
Table 4.5 Growth rate of Brachionus plicatilis over 72 h: effect of challenge with
the MM77 strain, with and without the addition of the washwater of the
MM30 or the BB152 strain 123
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Table 4.6 Growth rate of Brachionus plicatilis over 72 h: effect of the addition of
furanone 123
Table 4.7 Growth rate of Brachionus plicatilis over 72 h: effect of challenge with
the BB120 strain, follow by the addition of furanone 124
Table 4.8 Growth rate of Brachionus plicatilis over 72 h: effect of challenge with
Vibrio harveyi strains followed by the addition of 2.5 mg l-1 of furanone 125
Table 5.1 AHL molecules used in this study 140
Table 5.2 Vibrio harveyi strains used in this study 141
Table 5.3 HHL degradation capability of different isolates 148
Table 5.4 Growth rate of Brachionus plicatilis over 72 h: effect of challenge with
Vibrio harveyi wild-type strain and single mutants, in the absence and
presence of the enrichment culture EC5 153
Table 5.5 Growth rate of Brachionus plicatilis over 72 h: effect of challenge with
the MM77 strain, with and without the addition of the MM30 washwater,
in the absence and presence of the enrichment culture EC5 153
Table 6.1 Outline of the experiments conducted in this study 172
Table 6.2 Survival of turbot larvae on day 5 post-hatch, experiment 1 175
Table 6.3 Survival of turbot larvae on day 8 post-hatch, experiment 2 176
Table 6.4 Survival of turbot larvae on day 7 post-hatch, experiment 3 177
Table 7.1 Studies conducted on the isolation of AHL-degrading bacteria 195

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LIST OF FIGURES

Figure 1.1 World aquaculture production by major species groups in 2002 3
Figure 1.2 Microbial growth on the chorion of cod egg 18 days post-fertilization 19
Figure 1.3 Endocytosis of bacteria in enterocytes in the posterior part of the hindgut
in a 14-day-old herring larvae 24
Figure 1.4 The three important factors for the probability of viable larvae and
conditions that influence these factors 27
Figure 1.5 Model of the Vibrio harveyi quorum sensing systems 38
Figure 3.1 Growth rate over 5 days of Brachionus plicatilis hatched from
disinfected amictic eggs and fed three types of food: effect of the
addition of live MCs 98
Figure 3.2 Growth rate over 5 days of Brachionus plicatilis hatched from
disinfected amictic eggs and fed three types of food: effect of the
addition of autoclave-killed MCs 100
Figure 4.1 Vibrio counts in the Brachionus culture water at 0 h and 72 h 124
Figure 5.1 Cross-streak assay on LB agar plates supplemented with 0.1 mg l-1 HHL 147
Figure 5.2 HHL degradation curves of control cultures and enrichment cultures, as
indicated by the residual HHL concentration in the medium over 48 h 149
Figure 5.3 Induction of bioluminescence in the reporter strains by cell-free washwater
from the Vibrio harveyi strain BB120, in the absence and presence of the
enrichment cultures (Exp. 1) 150
Figure 5.4 Induction of bioluminescence in the reporter strains by cell-free washwater
from the Vibrio harveyi strain BB120, in the presence of 5 mg l-1 of
exogenous AHL mixture (Exp. 2) 151
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Figure 5.5 Relative log luminescence intensity of pure cultures / co-cultures of
Vibrio harveyi strains and ECs after 18 h incubation at 28°C 152
Figure 5.6 DGGE pattern of the enrichment cultures 154
Figure 6.1 PCR-DGGE profile of the enrichment cultures used in this study 169
Figure 6.2 Change in the number of EC5 bioencapsulated in the rotifers and total
rotifer-associated bacteria with time 174
Figure 6.3 Numbers of ECs and total culturable bacteria in the turbot culture water
on day 7 post-hatch, experiment 3 177
Figure 6.4 Numbers of ECs and total culturable bacteria in the turbot larval gut
on day 7 post-hatch, experiment 3 178
Figure 6.5 Numbers of EC3 and EC5 colonizing the turbot larval gut during the
post-experiment period 178
Figure 6.6 Residual AHL concentration in the rearing water, experiment 3 179
Figure 7.1 Frequency distribution of control samples by growth rate class 192

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CHAPTER 1

INTRODUCTION