Phosphatase activity with reference to bacteria and phosphorus in tropical freshwater aquaculture pond systems

Abstract

The bio-geochemical cycle of phosphorus is sig-ni®cantly in¯uenced by microbes in the aquatic environment. Organic phosphorus compounds are decomposed and mineralized by enzymatic complexes such as phosphatases produced by microbes. Enzymatic catalysis results in the production of orthophosphate, which can be used readily by primary producers. Even the smallest concentration of phosphate in water has an in¯uence over the production process in aquaculture systems. Extracellular alkaline phosphatase activity was observed in water and sediment media of aquaculture ponds with different management practices. Heterotrophic bacterial populations as well as phosphatase-producing bacterial populations were higher in sediments compared with water. In the freshwater ®sh ponds, Bacillus spp. were the dominant forms of bacteria producing phosphatase. The alkaline phosphatase activity of sediment was always higher than that of water. The partitioning of extracellular alkaline phosphatase in pond water by a 0.22-mm membrane ®lter revealed that a proportion was often free rather than cell associated and might have originated as free enzymes released by enriched sediments or by ®sh or microbes. In the case of water, although the dissolved alkaline phosphatase activity was lower than the total alkaline phosphatase activity, the former was nevertheless unimportant, as it constituted about 20% of the`total' activity. Free alkaline phosphatase activity shared a negative correlation with the orthophosphate concentration of water, whereas gross alkaline phosphatase activity was positively correlated with the total phosphorus and bacterial population of water.

Vertical Variation in Dissolved Alkaline Phosphatase Activity in a Shallow Eutrophic Lake Determined in Reverse Micelles

“…These facts support the hypothesis that deep waters, because of their young age, carry a larger amount of labile dissolved organic carbon, which reduces the need for a high recycling activity by bacterial community (Zaccone et al 2003). Although the activity of dissolved alkaline phosphatase (ADAP) was lower than the total APA, the former was nevertheless important (Barik et al 2001), and it mainly contributed more than 50% to the total APA in an oligotrophic lake (Hantke et al 1996). Interestingly, vertical heterogeneity was also observed in ADAP.…”

Fish Production, Water Quality and Bacteriological Parameters of Koi Carp Ponds Under Live-food and Manure Based Management Regimes

“…Lower counts of heterotrophic bacteria in control ponds not receiving any organic manuring have been reported earlier by many authors (Barat & Jana, 1990;Jana & De, 1990;Barik et al, 2001;Majumdar et al, 2002). As such, the control system appeared to be less productive, indicated from the significantly lower plankton abundance (P<0.05), compared to the manured treatments (Tab.…”

Characteristics of Selected Quality Parameters of the Swimming Pools Port in Szczecin

“…Akweny wodne są cennym elementem środowiska przyrodniczego i powinny być objęte właściwą ochroną [1][2][3][5][6][7][8][9]. Do najważniejszych ról jakie w środowisku przyrodniczym pełnią zbiorniki wodne należą: rola hydrologiczna, mikroklimatyczna, hydrosanitarna, przemysłowa [1,2,[7][8][9][10]12,14,[16][17][18][19].…”

“…Do najważniejszych ról jakie w środowisku przyrodniczym pełnią zbiorniki wodne należą: rola hydrologiczna, mikroklimatyczna, hydrosanitarna, przemysłowa [1,2,[7][8][9][10]12,14,[16][17][18][19]. Zgodnie z Ramową Dyrektywą Wodną, do 2015 r. wszystkie wody, w tym również w akwenach portowych, powinny mieć dobry stan ekologiczny [1,3,[6][7][8][9]12,15,16,19]. Baseny portowe należą do akwenów, których wody są szczególnie narażone na zanieczyszczenia w związku z przeładunkami jakie maja miejsce na ich terenie [11,13,20,21,[24][25][26].…”