Optimization of growth characteristics for the potential probiotics to be used in fish aquaculturing

Download

index.pdf

Date

2013

Author

Aytekin, Nihal Destan

Metadata

Show full item record

Item Usage Stats

249
views

85
downloads

The aquaculturing of marine and fresh water fish is continually increasing in the world and in Turkey. Of the three fish species; sea bass (Dicentrarchus labrax), seabream (Sparus aurata) and trout (Oncorhynchus mykiss), the latter has the highest share in Turkey, with a current production rate of 170000 tons per annum. The use of antibiotics in true feed is being phased out in the world. Probiotics have emerged one way of making up for the lack of antibiotics in the feed. In order to increase the probiotics usage, optimization of the strains’ growth conditions, development of sustainable and economic manufacturing process are required. While there are commercial probiotics for the farm animals, there is none so far produced for the aquaculture, in Turkey. Enterococcus faecium is one of the widely used probiotic in farm animals sector. Due to the characteristics of E. faecium to tolerate acid and bile salts in the gastrointestinal tract, to produce inhibitory compounds and show antagonistic effects towards target fish pathogens, to stimulate immune system and better growth, the microorganism may be evaluated as a strong potential probiotic for aquaculturing. Aim of this study was to optimize the culture conditions in order to maximize the biomass concentration and the biomass yield of E. faecium. In the first part of this study, several growth media, temperature and pH values were tested. In the second part, the microorganism was grown using different fermentation modes in bioreactor. In the last part, a membrane filtration system was incorporated to the fermentor in order to recycle biomass. Results showed that temperature 37 °C and pH 6.5 yielded higher amount of biomass compared to others. The biomass concentration was 6.3 g/L at pH 6.5, 37 °C, 350 rpm when the fresh medium was added continuously and biomass was recycled back to the fermentor using the membrane filter.

Subject Keywords

Antibiotics in aquaculture., Fish culture., Probiotics.

URI

http://etd.lib.metu.edu.tr/upload/12615925/index.pdf
https://hdl.handle.net/11511/22592

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Stock assessment of the Black Sea anchovy Tutar, Özge; Gücü, Ali Cemal; Department of Marine Biology and Fisheries (2014) The Black Sea anchovy (Engraulis encrasicolus) is economically the most important fish species in Turkey since it provides 60% of the total fish catch. The Turkish fleet catches 90% of the anchovy stock in the Black Sea due to the anchovy winter migration to the Turkish coast. Over the last 50 years, the Black Sea basin has been subjected to pollution due to human sourced nutrient accumulation in the NW basin via the rivers Danube, Dniester and Dnieper and transportation. The ecosystem has been destroyed by...
A box model for the basic elements of the northeastern Mediterranean Sea trawl fisheries Gücü, Ali Cemal (1995-01-01) A box model has been constructed for the northeastern Mediterranean Sea, where there is no reliable information on the total removal of fish by fisheries. The model utilizes survey data of biomass and these initial values are improved by a series of population dynamics methods. Once absolute values for the system components (length-weight relational growth parameters, mortality estimates, selection ogives, stomach content analysis) are established, biomass transfer within the ecosystem compartments is estim...
A Study on possible variant forms of anchovy in the black sea Şahin, Ezgi; Gücü, Ali Cemal; Department of Marine Biology and Fisheries (2014) The anchovy in the Black Sea is a commercially important fish source for Turkey, which is represented by two different subspecies in the basin. Spawning and feeding occurs in northern coasts where food supplies are more abundant. When the water temperature starts to decrease, the anchovy migrate toward the warmer waters of the southern coasts. The schools formed during this migration make them a primary target for fishing fleets. Due to morphological similarities, it is not possible to report the catches by...
Current distribution of the small pelagic fish populations in the North Eastern Levantine Sea in relation to environmental conditions and predicting the impacts of temperature rise on their future distributions Sakınan, Serdar; Gücü, Ali Cemal; Department of Marine Biology and Fisheries (2014) Stocks of traditionally targeted fish species are in decline in the north eastern Levant Sea due to overfishing during recent decades, while catch statistics show a simultaneous increase in landings of commercially less valuable small pelagic species. Moreover, the number of species in the eastern Mediterranean is increasing due to Lessepsian migration and the response of native species to the continuous migration of lessepsian species is in question. Additionally, warming associated with climate change is ...
Spatio-temporal patterns and environmental controls of small pelagic fish body condition from contrasted Mediterranean areas Brosset, Pablo; et. al. (2017-02-01) Small pelagic fish are among the most ecologically and economically important marine fish species and are characterized by large fluctuations all over the world. In the Mediterranean Sea, low catches and biomass of anchovies and sardines have been described in some areas during the last decade, resulting in important fisheries crises. Therefore, we studied anchovy and sardine body condition variability, a key index of population health and its response to environmental and anthropogenic changes. Wide tempor...

Citation Formats

N. D. Aytekin, “Optimization of growth characteristics for the potential probiotics to be used in fish aquaculturing,” M.S. - Master of Science, Middle East Technical University, 2013.