Cuevaenes A and B, new polyene carboxylic acids from Streptomyces sp. HKI 0180.
In the course of a screening for newmetabolites from strains of actinomycetes we disclosed Streptomyces sp. HKI 0180 as the producer of cuevaenes A (1) and B (2). The strain was isolated from a soil sample from the cave of Altamira (Spain). In this paper we report the production, isolation, structure elucidation and biological properties of 1 and 2 (Fig. 1). An agar slant culture of the above strain was used to inoculate a 500 ml Erlenmeyer flask containing 100ml of a seed medium composed of (g/liter): dextrose 15, soya bean meal 15, NaCl 5, CaCO3 1, KH2PO4 0.4, distilled water, pH 6.9. The producing medium contained (g/liter): mannitol 20, soya bean meal 20, distilled water, pH6.5.
Total syntheses of the proposed structures of cuevaene A
Two proposed structures of cuevaene A were synthesized and the NMR spectra of both structures are proved to be inconsistent with those of the natural product. The structure of cuevaene A is still unclear and needs to be revised.
Air scrubbing techniques for ammonia and odor reduction at livestock operations : review of on-farm research in the Netherlands
Acid scrubbers and biotrickling filters have been developed for ammonia (NH3) removal at pig and poultry houses 
in The Netherlands over the last 20 years to prevent acidification and eutrophication of soils. Because of growing 
suburbanization, odor removal is increasingly considered important as well. In this review, we report the results of the on-farm 
research on full-scale operated scrubbers for treatment of exhaust air from animal houses with regard to NH3 and odor 
removal in The Netherlands. The NH3 removal of acid scrubbers ranged from 40% to 100% with an overall average of 96%. 
The NH3 removal of biotrickling filters ranged from -8% to +100% with an overall average of 70%. Minimum empty bed air 
residence times (EBRTs) were 0.4 to 1.1 s. For acid scrubbers, process control with pH measurement and automatic water 
discharge is sufficient to guarantee sufficient NH3 removal. For biotrickling filters, however, improvement of process control 
is necessary to guarantee sufficient NH3 removal. The odor removal of acid scrubbers ranged from 3% to 51% with an overall 
average of 27%. The odor removal of biotrickling filters ranged from -29% to +87% with an overall average of 51%. 
Minimum EBRTs were 0.5 to 2.3 s. Further research is necessary to explain this variation and to improve the odor removal 
efficiency of both acid scrubbers and biotrickling filters.