Isolation and screening of brittlestar-associated bacteria for antibacterial activity.

Many microbes associated with marine organisms have antimicrobial activity. We report the isolation of bacteria associated with Amphipholis gracillima that have broad-spectrum antibacterial activity against a number of common bacterial strains. Fifty-eight isolates of bacilli obtained from A. gracillima arm homogenates, from excised wound tissue, or from swabs of arm stumps exhibited 20-100% inhibition of one or more of 16 test bacteria at 35% salinity. Forty-one of the isolates were capable of 20-100% inhibition of one or more of 19 subject bacteria at 10% salinity at 37 degrees C. Three isolates, BE37, BE52, and BE53, exhibited the greatest range of antibacterial activity at both 10% and 35% salinity. Our results suggest that some of the bacteria associated with A. gracillima may provide the animal with chemical defenses against adverse bacterial infection. The water-soluble inhibitory chemicals produced by the bacteria could potentially function as antimicrobial compounds against human pathogenic bacteria.

Nutrient Translocation during Early Disc Regeneration in the Brittlestar Microphiopholis gracillima (Stimpson) (Echinodermata: Ophiuroidea).

Microphiopholis gracillima can autotomize and then regenerate the autotomized central disc, including integument, gut, and gonads. Experiments were carried out to determine the relative importance of internal nutrient reserve translocation and exogenous nutrient uptake during the regeneration process. Approximately 60% of the dry body weight of M. gracillima is organic material. Intact animals held for three weeks in natural seawater did not change significantly in weight, caloric content, or relative concentration of protein, carbohydrates, or lipids. Intact animals held for three weeks in artificial seawater devoid of nutrients lost weight and caloric content. The rate of loss was rapid initially, but slowed after about eight days. Animals regenerated in natural seawater lost weight initially, then regained the lost weight. Animals regenerated in artificial seawater lost weight constantly and at a higher rate than either the artificial seawater control or natural seawater regenerated animals. All weight losses were attributable to significant changes in the protein and carbohydrate fractions of the organic body component. The lipid fraction and ash components did not change significantly in any treatment. M. gracillima appears to be adapted to regenerate the lost disk rapidly, even under conditions of food deprivation.

PD 116,152, a novel phenazine antitumor antibiotic. Discovery, fermentation, culture characterization and biological activity.

A novel phenazine antitumor antibiotic is described, produced by Streptomyces lomondensis subsp. galanosa NRRL 15738. The antibiotic is selectively active versus the bacterium Streptococcus pneumoniae (MIC less than 0.46 microgram/ml); the antitumor activity versus murine P388 leukemia is T/C 149.

Potent antitumor antibiotic complex: PD 114,759, PD 115,028, PD 119,707, and PD 119,193.

Four novel antitumor antibiotics (PD 114,759, PD 115,028, PD 119,707 and PD 119,193) are produced as a complex by a new species of Actinomadura. The proposed name for the culture is Actinomadura verrucosospora subsp. veractimyces ATCC 39363. The antibiotics are extremely bioactive, with MIC values of less than 0.006 ng/ml against several bacteria and ID50 values of 0.003 approximately 0.107 ng/ml against L1210 leukemia cells in vitro. Antitumor activities vs. P388 leukemia in vivo were observed at doses of 0.313, 0.40, and 0.5 micrograms/kg (daily X 5) for PD 119,707, PD 115,028, and PD 114,759, respectively.

Novel antitumor antibiotics, CI-940 (PD 114,720) and PD 114,721. Taxonomy, fermentation and biological activity.

The novel, broad-spectrum antitumor antibiotics, CI-940 (PD 114,720) and PD 114,721 are components of bioactive compounds produced by a novel actinomycete (ATCC 39366). The organism is unique in that whole cell analysis revealed LL-diaminopimelic acid and major amounts of arabinose. These new antibiotics exhibit potent antitumor activity in vitro and in vivo versus an array of tumors and possess strong antibacterial and antifungal activity. The above antibiotics are produced in 7,570-liter fermentors at yields of 5 approximately 8 micrograms/ml.

Fermentation by a new daunomycin-producing organism, Streptomyces insignis ATCC 31913.

A new organism belonging to the grey series of streptomycetes is described which produces 55 to 75 micrograms of daunomycin per ml in a sparged fermentor. This organism is not taxonomically related to other known daunomycin producers. Its proposed name in Streptomyces insignis ATCC 31913.

Novel antitumor agents CI-920, PD 113,270 and PD 113,271. I. Taxonomy, fermentation and biological properties.

CI-920 (PD 110,161) and two analogues (PD 113,270 and PD 113,271) are novel antitumor compounds produced by a new actinomycete characterized as Streptomyces pulveraceus subsp. fostreus ATCC 31906. The antitumor compounds are predominantly produced during the stationary (idiophase) growth phase of the organism. CI-920 is active versus the murine P388 lymphocytic and L1210 lymphoid leukemia with T/C values of 246 and 207, respectively. This compound has no significant antimicrobial activity.