GABELLONE Nestor Adrian
A quick and effective estimation of algal density by turbidimetry developed with Chlorella vulgaris cultures.
FERRANDO N; BENITEZ, HERNÁN; GABELLONE, N. A.; CLAPS, MARÍA CRISTINA; ALTAMIRANO, PABLO R.
ASOC ESPAN LIMNOL-MISLATA
Lugar: Barcelona; Año: 2015 vol. 34 p. 397 - 406
The use of Chlorella vulgaris Beijerinck as zooplankton food source requires the need to optimize algal-culture conditions for prolonged growth maintenance. In this paper we developed a method that relates algal density and culture turbidity to estimate culture biomass. This method was improved by applying digital analysis for algal counting that promotes accuracy, low culture disturbance, easy repetition and rapid acquisition obtainment of results. Two 3-L cultures of C. vulgaris, maintained for two weeks with continuous lighting (eight light-emitting diodes at 50 µmol photons m-2. s?1, at 660 nm) and using aerators to prevent algal sedimentation, reached turbidities of 214 and 280 NTUs, respectively. Sample counting was performed by digital images obtained using an inverted microscope. Aliquot sedimentation was compared with or without previous homogenization through photographs taken in the central, middle, and peripheral sectors of the Utermöhl settling chambers. For each procedure, we counted between 17 and 404 individuals image?1, taking an average time of one minute image?1. At low turbidity (