Bacillus thuringiensis var. israelensis production involving re-use of the supernatant.

The supernatant arising after biomass separation of Bacillus thuringiensis var. israelensis by flocculation/sedimentation was re-used after being supplemented with 25, 50 and 75% (w/v) of the original culture medium, based on corn steep liquor, glucose and mineral salts. Supplementation at 75% gave a spore concentration (1 x 10(10) c.f.u. ml(-1)) five times greater than that obtained with the other supplements.

Integrated control measures against Culex quinquefasciatus, the vector of filariasis in Recife.

Integrated control measures against Culex quinquefasciastus have been implemented in a pilot urban area in Recife, Brazil. About 3,000 breeding sites found within the operational area were responsible for very high mosquito densities recorded during the pretrial period. Physical control measures have been applied to cess pits before starting a series of 37 treatments of the other sites with Bacillus sphaericus strain 2362, over 27 months. In spite of the difficulties due to environmental conditions, very significant reductions in preimaginal population of C. quinquefasciatus were achieved and, as a consequence, low adult mosquito densities were maintained for a relatively long period of time. Entomological and environmental data gathered in this pilot project can contribute to design an integrated mosquito control program in Recife city.

Role of the exosporium in the stability of the Bacillus sphaericus binary toxin.

The persistence of toxicity of the Bacillus sphaericus 1593 binary toxin was compared when produced in B. sphaericus, inside the exosporium, or in a recombinant B. thuringiensis strain, outside the exosporium. The stability of the toxin crystal was affected by temperature and quality of the water, but not by the location of the production in the bacterial cell.

Bacitracin production by a new strain of Bacillus subtilis. Extraction, purification, and characterization.

A new strain of Bacillus subtilis C 126 was isolated from sugar cane fermentation and produced an antibiotic that inhibited the growth of Micrococcus flavus. The production of the antibiotic in culture medium followed to extraction with n-butanol, thin layer chromatography, and microbiological tests indicated that a polypeptide antibiotic was produced. The fraction obtained by Sephadex G-25 column and analyzed by HPLC indicated that bacitracin complex was produced.

Glicose isomerase from Zymomonas mobilis.

A atividade de glucose isomerase foi detectada em celulas de Zymomonas mobilis Kluyver & Van Niel, crescidas em meio liquido. A enzima foi parcialmente purificada, por precipitacao com sulfato de amonio o pH otimo da atividade isomerasica foi de 7,5-8,0 e a temperatura de incubacao 90 graus C

[Griseocarnin, an antifungal antibiotic isolated from Streptoverticillium criseocarneum (IA-7527)]. / Griseocarnin, um antibiótico antifúngico isolado do Streptoverticillium criseocarneum(ia-7527)

We have been studying the antagonistic activity of the Streptoverticillium griseocarneum, strain IA-7527. It produces a strong antifungal substance which we named griseocarnin. Its antimicrobial power to Neurospora crassa, Rhodotorula, rubra, Hansenula suaveolens and Candida albicans deserves to be exceled. The isolated substance was compared with other antifungal antibiotics presenting close similarity with the heptaens Ascosin and PA-150. The production, extraction and purification methods as well as physical, chemical and biological properties are included in this work.