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.
Isolation of Cave Bacteria and Substrate Utilization at Different Temperatures
Bacteria isolated from the soils of three northern Spain caves were investigated for their growth at temperatures in the range 5-45°C, substrate utilization pattern, and cellular fatty acid components. All tested bacteria were able to grow comparatively well in a range of temperatures from 13° to 45°C. At 13°C the bacteria oxidized on average 87% of carbon sources provided while incubation at 28°C reduced to about 50% carbon source utilization. Changes in fatty acid profiles reflected an adaptative response to temperature. The results suggest the need of using low temperatures to detect maximum diversity of culturable bacteria (other than actinomycetes) and efficiency of carbon utilization by cave bacteria.
The risk of Listeria monocytogenes infection in beef cattle operations
Aim:  To determine the prevalence of Listeria monocytogenes and associated risk factors among beef operations (cow‐calf and feedlot) in central and southern California.