Cultivo de Ankistrodesmus gracilis (Reisch) Korsikov (Chlorophyta) em laboratório utilizando meio CHU12 e de macrófita com NPK

Two different culture media, namely CHU12 and inorganic fertilizer NPK (20-5-20) associated with macrophyte (Eichhornia crassipes) extract, were used to evaluate the development of A. gracilis. Growth rate, development, nutritional value and medium water quality were analyzed. A. gracilis in macrophyte+NPK medium had mean cell density (333x10(5) cells/mL) higher than medium CHU12 (302x10(5) cells/mL). Protein rate (12.52% PS), dry weight (397x10(7) pg/cell) and ashes (4.08x10(7) pg/cell) in A. gracilis was higher (p<0.05) than medium macrophyte+NPK. on the other hand, lipids, carbohydrates and fibers had the same rate (p>0.05) in both media. When hydrological variables in the culture medium of A. gracilis are taken into account, dissolved oxygen and free CO2 alone failed to have any significant difference (p>0.05) between the media employed. A. gracilis in the macrophyte+NPK medium had the same nutritional rate as the commercial medium CHU12, with excellent results for alga growth. Macrophyte medium may be used for large scale alga culture in the feed of fish larvae.

Cultivo de Ankistrodesmus gracilis (Reisch) Korsikov (Chlorophyta) em laboratório utilizando meio CHU12 e de macrófita com NPK

Two different culture media, namely CHU12 and inorganic fertilizer NPK (20-5-20) associated with macrophyte (Eichhornia crassipes) extract, were used to evaluate the development of A. gracilis. Growth rate, development, nutritional value and medium water quality were analyzed. A. gracilis in macrophyte+NPK medium had mean cell density (333x10(5) cells/mL) higher than medium CHU12 (302x10(5) cells/mL). Protein rate (12.52% PS), dry weight (397x10(7) pg/cell) and ashes (4.08x10(7) pg/cell) in A. gracilis was higher (p<0.05) than medium macrophyte+NPK. on the other hand, lipids, carbohydrates and fibers had the same rate (p>0.05) in both media. When hydrological variables in the culture medium of A. gracilis are taken into account, dissolved oxygen and free CO2 alone failed to have any significant difference (p>0.05) between the media employed. A. gracilis in the macrophyte+NPK medium had the same nutritional rate as the commercial medium CHU12, with excellent results for alga growth. Macrophyte medium may be used for large scale alga culture in the feed of fish larvae.

Utilização de meios alternativos e diferentes tipos de recipientes no cultivo de Ankistrodesmus gracilis (Reinsch) Korshikov (Chlorophyceae) em laboratório

A laboratory culture of Ankistrodesmus gracilis algae was evaluated by studying the biology of the species and its chemical composition in a traditional medium (CHU 12) and in two alternative culture media, NPK (20-5-20) and macrophyte (Eichhornia crassipes) + NPK, in three different types of recipients (fiberglass, carboy and plastic bag). First peak in the growth curve of Ankistrodesmus gracilis occurred on the ninth day in macrophyte + NPK medium (74.16 x 10 5 cells mL -1) in a fiberglass recipient. However, highest density (p < 0.01) was reported in medium CHU 12 (122.87 x 10 5 cells mL -1) in a plastic bag on the twelfth day. Cell density was over 70 x 10 5 cells mL -1 starting on the twelfth day. Growth rate of A. gracilis was similar (p > 0.05) in culture media in the three recipients. Protein and fiber were similar (p > 0.05) in the treatments, but lipids were higher (p < 0.05) in NPK. Nitrate, ammonia, total phosphorus and orthophosphate contents were over 1 mg L -1 in NPK (p < 0.01). Results show that alternative media, such as NPK and macrophyte + NPK, are possible for large-scale culture of A. gracilis cultured in three types of recipients. Costs are low, occupying less space when cultured in plastic bags and in the laboratory.

Desempenho de Ankistrodesmus gracilis (Reischi) Korsikov (Chlorophyta) cultivada em três meios de cultura em laboratório

Pós-graduação em Aquicultura - FCAV