RESUMEN
To illustrate the species and characteristics of filamentous microorganisms in bulking sludge, culture method, microscopic examination and molecular biological analysis were conducted to isolate and identify the filamentous microorganisms existing in bulking sludge collected from municipal wastewater treatment plant. Filamentous microorganisms isolated by Gause's synthetic agar medium and starch agar fell into 18 genera, among which Streptomyces and Microbacterium belong to bacterial phylum Actinobacteria, all other isolates were classified into fungi. Penicillium, Cladosporium, Alternaria, Aspergillus and Trichosporon were the fungi with high occurrence frequency in culture medium. Trichosporon, Streptomyces, Penicillium and Alternaria could grow well at neutral pH or meta-acid condition. High concentration of NaCl could inhibit the growth of Trichosporon and Streptomyces, but had no obvious inhibitory effect on Penicillium and Alternaria. Except of Trichosporon, Streptomyces, Penicillium and Alternaria all could utilize saccharose, starch and cellulose. The increase of carbon source concentration could promote their growth. The results of high throughput sequencing of rDNA-ITS showed that a large number of unidentified fungi existed in bulking sludge.
