Liquefaction of sugarcane bagasse for enzyme production.

The objective of this paper is to report liquefaction of pretreated and sterilized sugarcane bagasse for enhancing endoglucanase production through submerged fermentation by Aspergillus niger. After initial solid state fermentation of steam pretreated bagasse solids by A. niger, fed-batch addition of the substrate to cellulase in buffer over a 12h period, followed by 36h reaction, resulted in a liquid slurry with a viscosity of 0.30±0.07Pas at 30% (w/v) solids. Addition of A. niger for submerged fermentation of sterile liquefied bagasse at 23% w/v solids resulted in an enzyme titer of 2.5IUmL(-1) or about 15× higher productivity than solid-state fermentation of non-liquefied bagasse (final activity of 0.17IUmL(-1)). Bagasse not treated by initial solid-state fermentation but liquefied with enzyme gave 2IUmL(-1). These results show the utility of liquefied bagasse as a culture medium for enzyme production in submerged fermentations.

ß-Lapachone activity in synergy with conventional antimicrobials against methicillin resistant Staphylococcus aureus strains.

The aim of this study was to evaluate the antimicrobial activity of lapachol, α-lapachone, ß-lapachone and six antimicrobials (ampicillin, amoxicillin/clavulanic acid, cefoxitin, gentamicin, ciprofloxacin and meropenem) against twelve strains of Staphylococcus aureus from which resistance phenotypes were previously determined by the disk diffusion method. Five S. aureus strains (LFBM 01, LFBM 26, LFBM 28, LFBM 31 and LFBM 33) showed resistance to all antimicrobial agents tested and were selected for the study of the interaction between ß-lapachone and antimicrobial agents, busing checkerboard method. The criteria used to evaluate the synergistic activity were defined by the Fractional Inhibitory Concentration Index (FICI). Among the naphthoquinones, ß-lapachone was the most effective against S. aureus strains. FICI values ranged from 0.07 to 0.5, suggesting a synergistic interaction against multidrug resistant S. aureus (MRSA) strains. An additive effect was observed with the combination ß-lapachone/ciprofloxacin against the LFBM 33 strain. The combination of ß-lapachone with cefoxitin showed no added benefit against LFBM 31 and LFBM 33 strains. This study demonstrated that, in general, ß-lapachone combined with beta lactams antimicrobials, fluoroquinolones and carbapenems acts synergistically inhibiting MRSA strains.

Evaluation of a Hypocrea jecorina enzyme preparation for hydrolysis of Tifton 85 bermudagrass.

Tifton 85 bermudagrass, developed at the ARS-USDA in Tifton, GA, is grown on over ten million acres in the USA for hay and forage. Of the bermudagrass cultivars, Tifton 85 exhibits improved digestibility because the ratio of ether- to ester-linked phenolic acids has been lowered using traditional plant breeding techniques. A previously developed pressurized batch hot water (PBHW) method was used to treat Tifton 85 bermudagrass for enzymatic hydrolysis. Native grass (untreated) and PBHW-pretreated material were compared as substrates for fungal cultivation to produce enzymes. Cellulase activity, measured via the filter paper assay, was higher for fungi cultivated on PBHW-pretreated grass, whereas the other nine enzyme assays produced higher activities for the untreated grass. Ferulic acid and vanillin levels increased significantly for the enzyme preparations produced using PBHW-pretreated grass and the release of these phenolic compounds may have contributed to the observed reduction in enzyme activities. Culture supernatant from Tifton 85 bermudagrass-grown fungi were combined with two commercial enzyme preparations and the enzyme activity profiles are reported. The amount of reducing sugar liberated by the enzyme mixture from Hypocrea jecorina (after 192 h incubation with untreated bermudagrass) individually or in combination with feruloyl esterase was 72.1 and 84.8%, respectively, of the commercial cellulase preparation analyzed under the same conditions.

Atividade antiestafilocócica do Plantago major L

O Plantago major é uma planta herbácea conhecida como transagem que ocorre espontaneamente nas regiões de clima temperado ou subtropical, sendo facilmente cultivada no Brasil. Popularmente é utilizada no tratamento de inflamações de boca e garganta, infecções intestinais e como agente antibacteriano. O infuso das folhas é usado como gargarejo no combate às inflamações da boca, garganta, gengivas sangrentas e parotidites. O estudo microbiológico para a avaliação da atividade do extrato hidro-alcoólico foi realizado pelo método de difusão em meio sólido, frente a doze isolados clínicos de Staphylococcus aureus, obtidos de feridas abertas da pele, secreções vaginais e da orofaringe. O extrato foi padronizado obtendo-se uma solução de concentração igual à 193,0 mg/ml. Os microrganismos foram identificados através de provas bioquímicas específicas e suas culturas foram mantidas em meio sólido Mueller-Hinton. A ciprofloxacina foi utilizada como padrão antibacteriano na concentração de 10,0 mg/ml. Os microrganismos mostraram-se sensíveis ao extrato hidro-alcoólico, apresentando halos de inibição entre 10,0 e 13,0 mm e para o padrão ciprofloxacina entre 10,0 e 15,0 mm. Baseados nos estudos acima descritos o trabalho continuará com a determinação da Concentração Mínima Inibitória (CMI).

Synthesis and microbiological activity of some 4-butyl-2H-benzo[1,4]thiazin-3-one derivatives.

The synthesis and physicochemical properties of 4-butyl-2H-benzo[1,4]thiazin-3-one derivatives are described. These new compounds were synthesised by alkylation in 4-N position and acylation and/or alkylation of 6-NH2 by phase transfer catalysis. Acid hydrolysis of 6-alkylacylamino group yielded 6-alkylamino-4-butyl-2H-benzo[1,4]thiazin-3-ones. The antimicrobial in vitro activity was determined on five compounds.

Noncatalytic docking domains of cellulosomes of anaerobic fungi.

A method is presented for the specific isolation of genes encoding cellulosome components from anaerobic fungi. The catalytic components of the cellulosome of anaerobic fungi typically contain, besides the catalytic domain, mostly two copies of a 40-amino-acid cysteine-rich, noncatalytic docking domain (NCDD) interspaced by short linkers. Degenerate primers were designed to anneal to the highly conserved region within the NCDDs of the monocentric fungus Piromyces sp. strain E2 and the polycentric fungus Orpinomyces sp. strain PC-2. Through PCR using cDNA from Orpinomyces sp. and genomic DNA from Piromyces sp. as templates, respectively, 9 and 19 PCR products were isolated encoding novel NCDD linker sequences. Screening of an Orpinomyces sp. cDNA library with four of these PCR products resulted in the isolation of new genes encoding cellulosome components. An alignment of the partial NCDD sequence information obtained and an alignment of database-accessible NCDD sequences, focusing on the number and position of cysteine residues, indicated the presence of three structural subfamilies within fungal NCDDs. Furthermore, evidence is presented that the NCDDs in CelC from the polycentric fungus Orpinomyces sp. strain PC-2 specifically recognize four proteins in a cellulosome preparation, indicating the presence of multiple scaffoldins.

Synthesis, anti-inflammatory and antimicrobial activities of new 1,2,4-oxadiazoles peptidomimetics.

A new series of 1,2,4-oxadizoles 6a-g have been synthesised in good yields using the peptide synthesis strategy. The prepared compounds were tested for anti-inflammatory and antimicrobial activities. The anti-inflammatory activities were determined in the rat paw oedema induced by carrageenin. Compounds 6a, c, f and g (i.v.) significantly inhibited the rat paw oedema induced by carrageenin depending upon the dose employed. The compounds were also evaluated for their in vitro antimicrobial activity. Some compounds were found to have significant activity against Gram positive and Gram negative microorganisms.

[Substituted thiazolidinediones and thioxothiazolidinones: synthesis and structure]. / Thiazolidinediones et thioxothiazolidinones substituées: synthèse et étude structurale.

Synthesis and physico-chemical properties of 3-(4-bromobenzyl)-, 3-(4-chlorobenzyl)-5-arylidene-thiazolidine-2,4-diones and 3-(4-chlorobenzyl)-4-thioxo-5-arylidene-thiazolidin-2- ones are described. Twelve new products were synthesized by the aldolisation-crotonisation reaction from aromatic aldehydes and N-alkylated thiazolidinediones or thioxothiazolidinones. Seven compounds were preliminary tested for their bacteriostatic activity.

Synthesis and antimicrobial activity of substituted imidazolidinediones and thioxoimidazolidinones.

Synthesis and physico-chemical properties of new 3-benzyl-4-thioxo-5-arylideneimidazolidine-2-ones and 3-benzyl-5-arylideneimidazolidine-2,4-dione are described. These compounds were synthesized by condensation reaction from aromatic aldehydes and 3-substituted imidazolidine-2,4-diones or 4-thioxoimidazolidine-2-ones. The N-alkylation of 5-benzylideneimidazolidine-2,4-dione led simultaneously to mono- and dialkylated derivatives. The nucleophilic addition of 1-methyl-3-benzylimidazolidine-2,4-dione with 2-cyano-3-(3,4-dichlorophenyl) acrylate also yielded the 3-substituted 5-arylideneimidazolidine-2,4-dione derivative. Antimicrobial in vitro activity was determined on some compounds.

[Synthesis and structure of substituted arylazo-imidazolidines and arylidenethiazolidines]. / Synthèse et structure des arylazo-imidazolidines et arylidènethiazolidines substituées.

Synthesis and physico-chemical properties of four 3-benzyl or 3-(4-chlorobenzyl)-4-thioxo-5-arylazo-imidazolidin-2-ones, five 3-(4-nitrobenzyl)-5-arylidenethiazolidine-2,4-diones and three 3-(4-phenyl-phenacyl)-4-thioxo-5-arylidenethiazolidin-2-ones have been described. These new products were synthesized by an aldolisation-crotonisation reaction from aromatic aldehydes and 3-substituted thioxothiazolidin-2-ones or thiazolidine-2,4-diones. The arylazo-imidazolidine compounds were synthesized by copulation of diazonium ions with imidazolidines. Antimicrobial activity was determined for some compounds.

[Synthesis and antimicrobial activity of some substituted 3-arylidenaminothienopyrimididones]. / Synthèse et activitié antimicrobienne de quelques arylidènamino-3 thiénopyrimidones-4 substituées.

The synthesis of six 2-methyl-3-arylidenoaminocyclohexeno [b] thieno [2,3-d]-3,4-dihydropyrimidin-4-ones is described. The biological activity of these new compounds was screened against several Gram-positive and Gram-negative bacteria. The activity of our compounds is 5 to 320 fold less active than ciprofloxacin.

[Ciprofloxacin, clarithromycin, rifampin: in vitro bactericidal activity of double and triple drug combinations against strains of atypical mycobacteria]. / Ciprofloxacine, clarithromycine, rifampicine: activité bactéricide in vitro de doubles et triple associations sur des souches de mycobactéries atypiques.

Bactericidal activity of ciprofloxacin (CIP), clarithromycin (CLA), rifampin (RIF) alone and in combinations was studied against five atypical mycobacteria (4 isolates from patients with Acquired Immunodeficiency Syndrome and 1 collection strain) by time killing curves method. Drugs were used at their attainable serum levels: CIP (1 microgram/ml), CLA (2 micrograms/ml), RIF (16 micrograms/ml). The decrease in CFU in comparison to inoculum (10(6)-10(7) CFU/ml) was evaluated by viable counts after 1, 2, 3, 4 and 5 days of incubation at 35-37 degrees C. Drug combinations enhanced slightly the killing of drugs alone. CIP+CLA was the most effective against MAC strains whereas CIP+RIF appeared as the best combination against rapidly growing species except M. phlei which was the most resistant strain.

Amylolytic activity of Humicola sp.

The thermophilic and cellulolytic fungus Humicola sp. secretes amylase in the liquid culture medium. This activity is induced by starch, maltose and cellobiose. Glucose impairs accumulation of amylolytic activity in the culture medium. The enzyme hydrolyzes starch, maltose and pullulan to glucose as the end-product.