Antidepressant effect and changes of GABAA receptor gamma2 subunit mRNA after hippocampal administration of allopregnanolone in rats.

The present study aimed to verify the effect of bilateral intra-hippocampus administration of the neurosteroid allopregnanolone (3alpha-hydroxy-5alpha-pregnan-20-one; 3alpha, 5alpha-THP) in the forced swimming test (FST) and in the alpha4 and gamma2 GABA(A) receptor subunits gene expression. Results showed that bilateral intra-hippocampal allopregnanolone administration of 2.5 microg/rat ( P<0.05) reduced immobile behavior and increased climbing behavior in the FST. Overall, for all doses of allopregnanolone tested (1.25, 2.5, 5.0 microg/rat), an increase of gamma2 (P<0.05) GABA(A) subunit mRNA was observed. There was a higher increase in the gamma2 gene expression in the right hemisphere than in the left hemisphere (P<0.01) after allopregnanolone treatment. Intra-hippocampal allopregnanolone did not change the expression of the alpha4 subunits. In conclusion, intra-hippocampal administration of allopregnanolone produces an antidepressant-like effect in the FST at an intermediate dose, confirming the potential of neurosteroids as a new class of antidepressant drugs. Our findings suggest that the gamma2, but not the alpha4 GABA(A) subunit, needs further evaluation to be involved in the antidepressant effect of allopregnanolone in the hippocampus and that there is a hemispheric diversity in the biochemical effect of the drug.

A low-cost fermentation medium for thermophilic protease production by Streptomyces sp. 594 using feather meal and corn steep liquor.

Protease production by Streptomyces sp. 594 was obtained after submerged fermentation (SF) and solid-state fermentation (SSF) using feather meal (FM) and corn steep liquor (CSL) as sole sources of carbon and nitrogen. Enzyme productions were 13.4 U ml(-1) in SF and 21.5 U g(-1) in SSF; these values were approximately 86% and 39% higher, respectively, than those obtained previously when yeast extract was used in place of CSL. The proteases, which belong to the serine and metalloproteinase classes, were active at high temperatures (55 degrees C to 90 degrees C) and over a wide range of pH values (5.0 to 10.0). Thus, these thermophilic proteases have shown interesting properties for industrial purposes. As far as we are concerned, this is the first contribution toward the microbial production of thermophilic proteases by a streptomycete using a low-cost medium composed of industrial poultry (FM) and corn processing by-products (CSL).

New group-specific 16S rDNA primers for monitoring foaming mycolata during saline waste-water treatment.

Newly designed group-specific PCR primers for denaturing gradient gel electrophoresis (DGGE) were used to investigate foaming mycolata from a bioreactor treating an industrial saline waste-water. Genetic profiles on DGGE gels were different with NaCl at 1.65 and 8.24 g l(-1), demonstrating that mycolata community was affected by salinity. A semi-nested PCR strategy resulted in more bands in community genetic profiles than direct amplification. DNA sequencing of bands confirmed the efficacy of the novel primers with sequences recovered being most similar to foam producing mycolata. The new group-specific primers/DGGE approach is a new step toward a more complete understanding of functionally important groups of bacteria involved in biological treatment of waste-water.

Thermophilic protease production by Streptomyces sp. 594 in submerged and solid-state fermentations using feather meal.

AIMS: Protease production by Streptomyces sp. 594 in submerged (SF) and solid-state fermentation (SSF) using feather meal, an industrial poultry residue, and partial characterization of the crude enzyme. METHODS AND RESULTS: Streptomyces sp. 594 produced proteases in SF (7.2 +/- 0.2 U ml(-1)) and SSF (15.5 +/- 0.41 U g(-1)), with pH increase in both media. Considering protease activity, values obtained in the liquid extract after SSF (6.3 +/- 0.17 U ml(-1)) were lower than those from SF. The proteases, which belong to serine and metalloproteinase classes, were active over a wide range of pH (5.0-10.0) and high temperatures (55-80 degrees C). Strain 594 was also able to degrade feather in agar and liquid media. Keratinase activity (80 U l(-1)) also confirmed the keratin degrading capacity of this streptomycete. CONCLUSIONS: Proteases produced using residues from poultry industry have shown interesting properties for industrial purposes. SIGNIFICANCE AND IMPACT OF THE STUDY: As far as we are concerned, this is the first contribution towards the production of thermophilic protease by a streptomycete in SSF using a keratinous waste.

Proteases from actinomycetes interfere in solid media plate assays of hyaluronidase activity.

Four hundred and fifteen actinomycete strains were screened for hyaluronidase activity in two plate assays media. In the first one, using hyaluronic acid as substrate and bovine serum albumin (BSA) to help precipitation of the nondegraded substrate, only strain 594 and hyaluronidase control were positive. In the second assay, plates with hyaluronic acid, but not BSA, gave the same results. For plates containing only BSA, proteinase activity was detected in strain 594. When hyaluronic acid was treated with pronase, the only clear zones, in the second assay without BSA, were those around hyaluronidase controls. Protease activity, commonly found in actinomycetes, was detected only in strain 594, among the 415 studied, when tested in hyaluronidase assay using hyaluronate plus BSA. This may be due to the composition of the growth medium, since media with different composition gave different results for protease activity in each of the 15 strains analyzed. These data suggest that proteases can affect an accurate detection of hyaluronidase in media containing proteins, not only from hyaluronate preparations, but also from other medium ingredients. Thus, for a correct interpretation of the method, they must be excluded. Commercial Hyaluronidase used as controls must be also tested for the presence of protease contamination.

Yeast communities associated with sugarcane in Campos, Rio de Janeiro, Brazil.

Yeast communities associated with sugarcane leaves, stems and rhizosphere during different phases of plant development were studied near Campos, in Rio de Janeiro, Brazil. Atmospheric temperature, soil granulometry and pH, and sugar cane juice degree Brix and pH were determined. Yeast communities associated with sugarcane were obtained after cellular extraction by shaking, blending and shaking plus sonication, and cultured on Yeast Nitrogen Base Agar plus glucose (0.5%) and Yeast Extract-Malt Extract Agar. No significant differences in yeast counts were found among the cellular extraction treatments and culture media. 230 yeast cultures were identified according to standard methods, and distinct yeast communities were found for each substrate studied. The prevalent species isolated from sugarcane were Cryptococcus laurentii, Cryptococcus albidus, Rhodotorula mucilaginosa and Debaryomyces hansenii.