Effects of secondary crops on bacterial growth and nitrogen removal in shrimp farm effluent treatment systems

Secondary crops provide a means of assimilating some effluent nitrogen from eutrophic shrimp farm settlement ponds. However, a more important role may be their stimulation of beneficial bacterial nitrogen removal processes. In this study, bacterial biomass, growth and nitrogen removal capacity were quantified in shrimp farm effluent treatment systems containing vertical artificial substrates and either the banana shrimp Penaeus merguiensis (de Man) or the grey mullet, Mugil cephalus L. Banana shrimp were found to actively graze biofilm on the artificial substrates and significantly reduced bacterial biomass relative to a control (24.5 ± 5.6mgCm−2 and 39.2 ± 8.7mgCm−2, respectively). Bacterial volumetric growth rates, however, were significantly increased in the presence of the shrimp relative to the control 45.2±11.3mgCm−2 per day and 22.0±4.3mgCm−2 per day, respectively). Specific growth rate, or growth rate per cell, of bacteria was therefore appreciably stimulated by the banana shrimp. Nitrate assimilation was found to be significantly higher on grazed substrate biofilm relative to the control (223±54 mgNm−2 per day and 126±36 mg Nm−2 per day, respectively), suggesting that increased bacterial growth rate does relate to enhanced nitrogen uptake. Regulated banana shrimp feeding activity therefore can increase the rate of newbacterial biomass production and also the capacity for bacterial effluent nitrogen assimilation. Mullet had a negligible influence on the biofilm associated with the artificial substrate but reduced sediment bacterial biomass (224 ± 92 mgCm−2) relative to undisturbed sediment (650 ± 254 mgCm−2). Net, or volumetric bacterial growth in the sediment was similar in treatments with and without mullet, suggesting that the growth rate per cell of bacteria in grazed sediments was enhanced. Similar rates of dissolved nitrogen mineralisation werefound in sediments with and without mullet but nitrificationwas reduced. Presence of mullet increased water column suspended solids concentrations, water column bacterial growth and dissolved nutrient uptake. This study has shown that secondary crops, particularly banana shrimp, can play a stimulatory role in the bacterial processing of effluent nitrogen in eutrophic shrimp effluent treatment systems.

Develop added value uses of high anti-bacterial honey

Honey is valued for its medicinal properties. There interest from industry to develop a rapid method to detect the bioactivity of honey and also to develop value added products from high antibacterial honey.

Reiss family portrait; (l-r) Olga, Herbert, Flora Lotte, Walter, Moritz and Kurt; Saaz, Czechoslovakia Portraits Family

Olga Reiss nee Kohn died 1950s; Herbert Reiss, 1905-circa 1980; Flora Lotte "Lola" Reiss, 1910-1995; Walter Reiss, 1908-1937; Moritz Reiss, 1876-1965; Kurt Reiss, 1906-1996

Studio portrait of Flora Lotte "Lola" Reiss Portraits Women

Signed by photographer bottom right

Flora Lotte "Lola" Reiss in drivers seat of car Portraits Women

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Studio portrait of Flora Lotte "Lola" Reiss; Saaz, Czechoslovakia Portraits Women

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Flora Lotte "Lola" Reiss walking in the street; Toronto Portraits Women

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Flora Lotte "Lola" Reiss walking in the street with her father Moritz; Karlovy Vary (Carlsbad) Portraits Family

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Flora Lotte "Lola" Reiss walking in the street with her non-Jewish boyfriend Walter; Karlovy Vary (Carlsbad) Portraits Family

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Studio portrait of Flora Lotte "Lola" Reiss Portraits Women

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Flora Lotte "Lola" Reiss outdoors in a garden Portraits Women

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Flora Lotte "Lola" Reiss driving a car Portraits Women

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Flora Lotte "Lola" Reiss outdoors in a garden Portraits Women

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