Water Quality and Nutrient Dynamics of Biofloc with Different C/N Ratios in Inland Saline Water

A study evaluating water quality and nutrient dynamics in inland saline water was carried out using biofloc technology with different C/N ratios employed to raise Litopenaeus vannamei juveniles. The study was carried out for 60 days in FRP with no water exchange. Salinity, temperature, Dissolved oxygen, pH, nutrients, Biofloc Volume and Total Suspended Solids were monitored. All biofloc units indicated reduction in alkalinity at 40th day except the treatment with highest (25:1) C/N ratio, pH and alkalinity was not significant different among various treatments. Dissolved Oxygen was found to be significantly decreasing with increasing C/N ratios. The least Dissolved Oxygen was recorded at higher C/N ratios of 20:1 and 25:1 at the end of experiment. The Total Ammonical Nitrogen (TAN) and NO2–Nin C/N ratios 15:1 and 20:1 were found to have a significantly decreasing in trend after 20th and 18th day respectively. The NO3–N, PO43-–P, BVF and TSS in biofloc were shown an increasing trend in all the experiments. The present study elucidates the suitability of optimum C/N ratios in biofloc for maintaining the water quality to raise L. vannamei in inland ground saline water. The finding could help in reducing the environmental concern saline waste water discharge from the shrimp pond to the land.

New host record of five Flavobacterium species associated with tropical fresh water farmed fishes from North India

Abstract Yellow pigmented, filamentous, Gram-negative bacteria belonging to genus Flavobacterium are commonly associated with infections in stressed fish. In this study, inter-species diversity of Flavobacterium was studied in apparently healthy freshwater farmed fishes. For this, ninety one yellow pigmented bacteria were isolated from skin and gill samples (n = 38) of three farmed fish species i.e. Labeo rohita, Catla catla and Cyprinus carpio. Among them, only twelve bacterial isolates (13.18%) were identified as Flavobacterium spp. on the basis of morphological, biochemical tests, partial 16S rDNA gene sequencing and phylogenetic analysis. On the basis of 16S rDNA gene sequencing, all the 12 isolates were 97.6-100% similar to six different formally described species of genus Flavobacterium. The 16S rDNA based phylogenetic analysis grouped these strains into six different clades. Of the 12 isolates, six strains (Fl9S1-6) grouped with F. suncheonense, two strains (Fl6I2, Fl6I3) with F. indicum and the rest four strains (Fl1A1, Fl2G1, Fl3H1 and Fl10T1) clustered with F. aquaticum, F. granuli, F. hercynium and F. terrae, respectively. None of these species except, F. hercynium were previously reported from fish. All the isolated Flavobacterium species possessed the ability of adhesion and biofilm formation to colonize the external surface of healthy fish. The present study is the first record of tropical freshwater farmed fishes as hosts to five environmentally associated species of the Flavobacterium.

Seasonal variations in abundance of nitrifying bacteria in fish pond ecosystem.

Seasonal changes in abundance of nitrifiers (ammonia-oxidizing and nitrite-oxidizing bacteria) in surface and bottom water of freshwater ponds were examined with respect to temperature, DO, pH as well as concentration of ammonia and nitrite. The most probable number (MPN) of ammonia-oxidizers in different ponds varied from 1297±3.6 to 1673.23±0.36 ml-l in bottom and 720.5±8.1 to 955.3±10.8 ml-l in surface water during the rainy season while the MPN ranged from 1074±1.07 to 1372.17±4.6 ml-l in bottom and 515±10.1 to 678±11.8 ml-l in surface water in winter. However, the MPN were greatly reduced in summer and ranged from 435.05±15.7 to 547.54±2.12 ml-l in bottom and 218.7±7.3 to 368.4±9.32 ml-l in surface water. Similar seasonal trends were also observed in MPN of nitrite-oxidizers. Among all the physico-chemical parameters, abundance of nitrifiers was more positively correlated with ammonia and nitrite concentration in all the seasons. The abundance of nitrifiers in surface and bottom water was highest in rainy season followed by winter and modest in summer. The potential nitrification activities and oxidation rates were shown to be linear and activity of ammonia-oxidizing and nitriteoxidizing bacteria was highest during rainy season.

Development and characterization of two new cell lines from common carp, Cyprinus carpio (Linn)

Two new cell lines (CCF and CCH) were established from fin and heart tissues of common carp, Cyprinus carpio. The cells were optimally maintained in Leibovitz-15 medium supplemented with 10 percent fetal bovine serum (FBS) and 10 ng/ml of basic fibroblastic growth factor (bFGF). The effects of temperature, concentration of FBS and bFGF on the growth of CCF and CCH cells were examined. The temperature ranged from 24 to 32 °C for good growth of the cells. The growth rate of cells was higher in medium containing 10 percent FBS and the addition of bFGF to the medium significantly increased the growth rate. The CCF cells were found to be epithelial, while the CCH cells were fibroblastic in nature. The cytogenetic analysis of the cell lines revealed a diploid number of 100 chromosomes in C. carpio. The viability of CCF and CCH cell lines were 70 and 72 percent, respectively, after six months of storage in liquid nitrogen (-196 ° C). Molecular characterization of the cell lines using 16S rRNA and Cytochrome Oxidase Subunit I (COI) revealed the origin of the cell lines. These new cell lines will be useful for isolation of fish viruses and other in vitro biotechnological studies.

Affinity purification and partial characterization of IgM-like immunoglobulins of African catfish, Clarias gariepinus (Burchell, 1822).

IgM like macroglobulin from bovine serum albumin (BSA)-immunized African catfish C. gariepinus was purified by affinity chromatography and partially characterized. The molecular weight of this macroglobulin was 840 kDa, as estimated by gel filtration chromatography. Purified macroglobulin was analyzed using SDS-PAGE under reducing and non-reducing conditions. The molecular weight (MW) of heavy and light chain was 74.8 kDa and 27.2 kDa respectively, in presence of a reducing agent. In non-reducing SDS-PAGE, a single high MW band was observed representing tetrameric form.