Decentralized sanitation implementation in Vietnam: a peri-urban case study.

This research presents one of the first comprehensive case studies of a small-scale wastewater management project in Vietnam. The research demonstrates how the community integrated a small-scale wastewater management system based on household participation and community management. It is argued that local resources of peri-urban and small towns could be used more efficiently to contribute to wastewater management in Vietnam if appropriate technologies are used and if their management and technical capacities are reinforced.

Antagonistic properties of two recombinant strains of Streptomyces melanosporofaciens obtained by intraspecific protoplast fusion.

Intraspecific protoplast fusion was used to produce stable prototrophic recombinants of Streptomyces melanosporofaciens EF-76, a biocontrol agent of plant disease producing geldanamycin. Two recombinant strains (FP-54 and FP-60) that differed with regard to their antagonistic properties against Bacillus cereus ATCC 14579, Streptomyces scabies EF-35 and Phytophthora fragariae var. rubi 390 were characterized. FP-60 lost the ability to inhibit the in vitro growth of these microbial strains while FP-54 exhibited higher antagonistic activities against them. FP-60 was deficient in geldanamycin biosynthesis whereas FP-54 was shown to produce, in addition to geldanamycin, at least two other antimicrobial compounds that were absent in the culture supernatants of strain EF-76. Like the wild-type strain EF-76, strain FP-54 reduced common scab symptoms on potato tuber but no significant difference was observed between the disease index attributed to tubers treated with strain EF-76 or with strain FP-54. Strain FP-60 showed no protective effect against common scab. The disease index of tubers treated with this recombinant was worse than the index associated with potato tubers from control treatments.