YOMEDIA
Bài giảng Quản lý chất lượng môi trường trong nuôi trồng thủy sản: Phần 2
Chia sẻ: Lavie Lavie
| Ngày:
| Loại File: PPT
| Số trang:152
144
lượt xem
21
download
Download
Vui lòng tải xuống để xem tài liệu đầy đủ
Bài giảng Quản lý chất lượng môi trường trong nuôi trồng thủy sản: Phần 2 gồm có 3 chương trình bày về khái niệm về vi sinh vật trong nguồn nước; ảnh hưởng của chất lượng nước ao đến môi trường xung quanh và chất lượng sản phẩm; tiến trình quan trắc chất lượng môi trường nước phục vụ nuôi trồng thủy sản.
AMBIENT/
Chủ đề:
Nội dung Text: Bài giảng Quản lý chất lượng môi trường trong nuôi trồng thủy sản: Phần 2
- QUẢN LÝ CHẤT LƯỢNG MÔI TRƯỜNG
TRONG NUÔI TRỒNG THỦY SẢN
- Chương 3:
Khái niệm về vi sinh vật trong nguồn nước
- Microbial Interactions with Macroorganisms
Aquatic environment is relatively
rich in microorganisms
Up to 105 to 106 cells / mL
Cilliates, other protists, and viruses
Macroorganisms in aquatic
environment
Constantly exposed to
microorganisms
- Historical perspectives
Changes during storage
Effects on spoilage
Relationship between
environmental and fish
microflora
Basis for monitoring changes in fish
farms
Disease causing bacteria
Human
Fish & Shellfish
Increasingly, more focus on normal
microflora and their interactions
with the host organisms
- Microbiology of bivalve mollusks
Microorganisms as food
Natural microflora
Filter feeders and the ecosystem
Hansen and Olafsen, 1999; Maeda, 2002
- Microorganisms as food
Filter feeders Deposit feeders
(Suspension feeders) Feed on microorganisms that
Feed on microorganisms that coats the surface of sediments
they filter out of the and soil particles
environment
Clams, oysters, barnacles, Worms, fiddler crab
sponge
Larval forms of animals may require smaller microorganisms
such as bacteria, while an adult may prefer larger
microorganisms such as flagellated protists and algae
- Oyster anatomy
Labial palps Draw water in over its gills
through the beating of cilia
Suspended food (plankton) and
Visceral mass particles are trapped in the
mucus of the gills
Sort by labial palps and transport
Lower intestines
to the mouth, eaten, digested,
and feces expelled
Pseudofeces = particles which are
not sorted as food and are
rejected through the mouth
Affect by temperature
Rectum and anus Greatest when water temperature
> 50°F (~10°C)
Oyster anatomy lab http://www.mdsg.umd.edu/oysters/anatlab/index.htm
- Oyster filtering mechanism lab http://www.mdsg.umd.edu/oysters/oysfilt.htm
- Natural microflora of mussels and oysters
A majority of isolates are gram-negative (68%) and aerobic
(76%) bacteria
Predominant flora: Vibrio, Pseudomonas, Shewanella,
Aeromonas, Acinetobacter, and Flavobacterium
Gram-positive bacteria: Staphylococcus, Bacillus,
Streptococcus
Predominant Vibrio species includes:
V. alginolyticus, V. splendidus, and V. (Listonella) anguillarum*
Not always reflect external environment
Suggests selective process to sequester and maintain certain species
Kueh and Chan, 1985 ;Hariharan et al., 1995
- Filter feeders and the ecosystems
An adult oyster can filter as much as 60 gallon per day
Oysters can filter out sediments and nutrients (nitrogen) and
deposit them on the bottom
“Top-down" grazer control on phytoplankton
Reduce turbidity, increasing the amount of light reaching the sediment
surface
Extending the depth to which ecologically important benthic plants
(seagrasses and benthic microalgae) can grow
Newell, 2004 ;Chesapeake Bay Foundation http://www.cbf.org/
- Filter feeders bivalves removing inorganic and organic particles from water column and
transferring undigested particulate material to the sediment in the form of their biodeposits
Newell, 2004
- Microbiology of Fish
Eggs, skin, gills microflora
Intestinal microflora
- Bacteria on mucosal surface (1)
Host-parasite relationship
Host = an organism which harbors parasite (microorganisms)
Parasite = an organism that lives on or in a second organism
Surfaces such as eggs, skin, gills, and intestinal tract
Mucus layer as an adhesion site and protective layer
Indigenous vs. transient (autochthonous vs. allochthonous)
Indigenous = able to grow and multiply on the surface of the host animal
Transient = not able to grow or multiply on the surface of the host animal;
does not persist for a long period of time
- Bacteria on mucosal surface (2)
Loose association Adhesion Invasion
- Eggs microflora
Fish embryos secret inorganic and low molecular weight organic
compound, which can diffuse out through the shells
Attract bacteria utilizing these compounds and colonize egg
surface
Normal healthy eggs flora: Cytophaga, Pseudomonas
Dead eggs: fluorescent Pseudomonas
Not the cause of dead, but rather attracting to nutrient leaching
Overgrown of bacteria can hamper eggs development
Leucothrix mucor on cod eggs Flavobacterium ovolyticus on halibut eggs
Cahill, 1990; Hansen and Olafsen, 1999
- Skin Microflora
Reflect that of surrounding water
May have from 102 to 104 bacteria/ cm2
Unit of measurement per area
Surface sampled by using a sterile swab
Muscle tissue should be sterile
Gram negative: Pseudomonas, Moraxella, Vibrio, Flavobacterium,
Acinetobacter, Aeromonas
Gram positive: Micrococcus, Bacillus
Cahill, 1990
- Gill Microflora
May contain 102 to 106 bacteria/ g
The number is quite low considering its high surface area and being
continual flushed by water
Extensive colonization of certain types of bacteria (Flavobacterium)
Gram negative: Pseudomonas, Flavobacterium, Vibrio,
Moraxella, Cytophaga
Gram positive: Micrococcus, Bacillus (in warmer water)
Cahill, 1990
- Intestinal microflora (1)
Established at the larval stage
Developed into a persistent flora at the juvenile stage
Population of microorganisms tends to increase along the length
of the GI tract
Largest number of bacteria in the intestines (up to 10 8 CFU/g)
Gram negative: Pseudomonas, Vibrio, Achromobacter,
Flavobacterium, Corynebacterium, Aeromonas
Gram positive: Bacillus, Micrococcus
Influenced by stages of life, diets, feeding, water temperature,
habitat
Large number when feeding, very few when not feeding
Organic content of the environment
Vibrio dominates in seawater, Aeromonas dominates in freshwater
Cahill, 1990; Hansen and Olafsen, 1999
- Intestinal microflora (2)
Microvilli of the epithelial cells of
common wolffish (A. lupus L.)
Bacteria
SEM of the enterocytes in the
midgut of Artic charr
Ringo et al., 2003
- Intestinal microflora (3)
Endocytosis of bacteria in the
hindgut of spotted wolffish fry
Bacteria
TEM of Atlantic salmon gut epithelium
Ringo et al., 2003
Thêm tài liệu vào bộ sưu tập có sẵn:
Báo xấu
LAVA
ERROR:connection to 10.20.1.100:9315 failed (errno=111, msg=Connection refused)
ERROR:connection to 10.20.1.100:9315 failed (errno=111, msg=Connection refused)
Đang xử lý...
Thêm vào BST
Báo xấu
