Heterotrophic bacterial profile in Penaeus monodon pond sediment, rearing water and water source in one rearing cycle

Angeli A. Valera and Buenaflor D. Jimenez
Phenotypic profile of heterotrophic bacteria in Penaeus monodon pond sediment sediment, rearing water and water source of BFAT-NFRDI ponds at Pacita, Lala, Lanao del Norte was determined within one rearing cycle. Sampling was done weekly in the four designated sites: Site A (water source), Site B and C (ponds with P. monodon) and Site D (pond without P. monodon). Composite samples of water and sediment were collected and cultured in nutrient agar medium by serial dilution and streak plate method. Isolates were then purified and subjected to biochemical tests. A total of 185 isolates were obtained. Gram-negative bacteria were higher in sediments (58-63%) than in the water samples (54-63%). Vibrionaceae had the most number of isolates in water samples (7-13 isolates). Micrococcaceae had the most number of representative isolates in the sediments of Sites B and C. It is also had the highest density in sediments of the unreared pond in several weeks. Decrease in both diversity and evenness in the rearing water were observed after introduction of feeds on the fourth week. In this period, Vibrionaceae and Bacillaceae dominated in the ponds (B and C). Diversity and evenness decreased on the fifth week in sediments of sites B, C and D. The abundance of bacterial groups in influenced by presence of other biotic components, prawn, rearing practices, and water quality withon the ponds. Ratio of Vibrionaceae against other bacterial groups was generally higher in the rearing water than the pond sediments. In the presence of Pseudomonadaceae, Vibrionaceae percentage abundance in sediments has a maximum of only 30%, suggesting the group’s relative importance in the pond system.

FIMFS 39th Annual Convention. 29-31 October 2007. Visayas State University, Visca, Baybay City, Leyte