Abstract: This paper studied the effects of probiotics on the sediment of Penaeus annamei pond during 117 days of culture period. The results showed that probiotics application significantly decreased the concentrations of total nitrogen, total phosphorous, and sulfide in sediment, but no significant difference was observed in total plate count (TPC) of microbes between treated and control ponds. The final average presumptive vibrio count (PVC) of treated pond sediment (3.65×10³ cfu·g^-1) was significantly lower than that of the control (1.16×10⁵ cfu·g^-1), while the average number of BS (Bacillus), AB (ammonifying bacteria), PSOB (presumptive sulphur oxidizing bacteria) and SRB (sulphur reducing bacteria) in treated pond sediment was higher than that of the control. These data showed that probiotics could decrease the nutrients (nitrogen, phosphate and sulfur) accumulation and improve the composition of bacterial populations in pond sediment, and thus, supply a good sediment environment for the healthily culture of the shrimp.

Key words: Broadleaved Korean pine forest, Spectral solar radiation