Population dynamics of Brachionus calyciflorus (Rotifera: Brachionidae) in waste water from food-processing industry in Mexico
Por:
Stevenson R.A.A., Sarma S.S.S., Nandini S.
Publicada:
1 ene 1998
Resumen:
Waste water from Mexico's largest food processing industrial sector (based on maize, nejayole water) was used for growing Brachionus calyciflorus isolated from Lake Chapultepec in the Federal District of Mexico (D.F.). Nejayote water was collected from Colonia Providencia, D.F. Experiments were conducted at 25°C in 25 ml capacity vials with 20 ml of medium into which we introduced B. calyciflorus at an initial density of 1 ind ml-1. The experimental design consisted a total of 33 test vessels (2 food combinations X 5 densities X 3 replicates = 30 plus 3 replicates as controls that contained only algae). Experiments were terminated after day 16. Waste water in original concentration did not support rotifers. However, when diluted to 5 concentrations (ranging from 2% to 32% and pH adjusted to 7.0), rotifer density increased with increasing concentration of waste water. Green algae (at constant density of 2 X 106 cells ml-1 of Chlorella) in combination with waste water resulted in a higher abundance of rotifers only at higher concentrations (above 8%) of waste water. The maximum peak density of rotifers (238 ± 50 ind ml-1) was obtained at 16% dilution of waste water and with addition of Chlorella. The rate of population increase per day (r) (mean ± SD) varied from 0.355 ± 0.059 to 0.457 ± 0.048 depending on food combination and concentration.
Filiaciones:
Nandini S.:
Carrera de Biología, UNAM Campus Iztacala, AP 314, Edo. de Mexico, Mexico
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