The objective of this study was to evaluate the antibacterial action of filamentous bacteria isolated from the Byrsonima crassifolia leaf. An endophytic bacterium has been identified by classical and molecular techniques as Streptomyces ansochromogene . Screening for antibacterial action against pathogens with medical relevance ( Klebsiella pneumoniae ATCC 700603, Pseudomonas aeruginosa ATCC 15692, Staphylococcus aureus ATCC 6538, Corynebacterium diphtheriae ATCC 27012, Mycobacterium abscessus , Cryptococcus gattii ATCC 24065, and Cryptococcus neoformans ATCC 24067) demonstrated activity against the bacterium P. aeruginosa ATCC 0030 with inhibition diameter zones (IDZ) of 17.6 ± 0.25 mm in the preliminary screening in solid medium. After fermentation in liquid medium, an IDZ of 19.6 ± 0.46 mm and a minimum inhibitory concentration (MIC) of 0.5 mg/mL were detected. The antibiofilm action was observed with 100% inhibition of biofilm formation at a concentration of 0.250 mg/mL. When the infection curve was prepared, it was observed that the metabolite was effective in protecting the larvae of Tenebrio molitor . The metabolite does not show toxicity for eukaryotic cells. The leishmanicidal activity demonstrated that the metabolite presented a dose-dependent effect on the promastigotes forms of Leishmania amazonensis growth and the estimated IC 50 /72 h was 71.65 ± 7.4 μg/mL. Therefore, it can be concluded that the metabolite produced by the endophytic bacterium Streptomyces sp. is promising for future use as an alternative strategy against bacterial resistance.

Statins are drugs used for people with abnormal lipid levels (hyperlipidemia) and are among the best-selling medications in the United States. Thus, the aspects related to the production of these drugs are of extreme importance for the pharmaceutical industry. Herein, we provide a non-exhaustive review of fungal species used to produce statin and highlighted the major factors affecting the efficacy of this process. The current biotechnological approaches and the advances of a metabolic engineer to improve statins production are also emphasized. The biotechnological production of the main statins (lovastatin, pravastatin and simvastatin) uses different species of filamentous fungi, for example Aspergillus terreus. The statins production is influenced by different types of nutrients available in the medium such as the carbon and nitrogen sources, and several researches have focused their efforts to find the optimal cultivation conditions. Enzymes belonging to Lov class, play essential roles in statin production and have been targeted to genetic manipulations in order to improve the efficiency for Lovastatin and Simvastatin production. For instance, Escherichia coli strains expressing the LovD have been successfully used for lovastatin production. Other examples include the use of iRNA targeting LovF of A. terreus. Therefore, fungi are important allies in the fight against hyperlipidemias. Although many studies have been conducted, investigations on bioprocess optimization (using both native or genetic- modified strains) still necessary.

Actinomycetes are aerobic and gram-positive spore forming bacteria. They belong to the order actinomycetales and are characterized by substrates and aerial mycelium growth. They are the most abundant microorganisms in soil. They play important roles in the cycling of organic matter and inhibit the growth of several plant pathogens in the rhizosphere. Due to the presence of enzymes such as proteases and chitinase, actinomycetes have been studied as a natural controller of insects and phytopathogenic fungi that cause considerable losses in agriculture. Additionally, the facilities for the industrial manipulation of cultures, and the diversity of metabolites produced make actinomycetes preferred for the control of pests. Furthermore, actinomycetes constitute a "green" alternative for controlling insects and fungi, since they do not contaminate the environment, and are natural members of the soil. They also contribute to the sustainability of soil by formation and stabilization of compost piles, due to their degrading capabilities, and ability to form stable humus. Moreover, they can be associated with other soil microorganisms to degrade recalcitrant residues like celluloses to maintain biotic soil equilibrium.

Resumo: O manguezal é um ecossistema rico, porém muito limitante para o crescimento microbiano, por ser um ecossistema de transição o mesmo limita a diversidade microbiana, de fauna e flora. Nesse contexto, os microorganismos que estão presentes nesse habitat possuem habilidades de sobrevivência interessantes no contexto biotecnológico, sendo potenciais produtores de enzimas de interesse industrial. Após feita a coleta, foram realizadas análises físico-químicas do solo com o intuito de se conhecer as propriedades de granulometria, matéria orgânica, umidade e pH. Após o isolamento e identificação dos microorganismos do solo da área de manguezal, foi encontrada uma variedade de bactérias e fungos, totalizando dezesseis bactérias equivalentes a 68,75% dos microorganismos totais entre elas um actinomiceto e cinco fungos equivalentes a 31,25% das amostras. Estes microorganismos passaram por uma seleção de crescimento em meios de culturas diversificados e foram identificados através de sua macromorfologia e microscopia óptica por meio de coloração de gram.Palavras-chave: Bioprospecção, Isolamento, Microorganismos. Abstract:The mangrove is a rich ecossystem, but very limiting for the microbial growth, being a transition ecosystem the same limits the microbial diversity, of fauna and flora. In this context, the microorganisms that are present in this habitat have interesting survival skills in the biotechnological context, being potential producers of enzymes of industrial interest. After the collection, physicalchemical analyzes of the soil were carried out with the purpose of knowing the properties of granulometry, organic matter, humidity and pH. After isolating and identification soil microorganisms from the mangrove area, a variety of bacteria and fungi were found, totaling sixteen bacteria equivalente to 68,75% of the total microorganisms including a actinomycete and five fungi equivalente to 31,25% of the samples. These microorganisms underwent a selection growth in diverse culture media and were identified through their macromorphology and optical microscopy by gram staining. Physical and chemical analysis of the soil was carried out in order to know its properties.

This study aimed to evaluate the antibacterial, leishmanicidal, and cytotoxic potential of metabolites produced by bacteria isolated from rhizosphere soil samples. The bacterium was identified by molecular techniques as Streptomyces kronopolitis. A preliminary screening was carried for the antimicrobial activity of S. kronopolitis, demonstrating activity against Staphylococcus aureus ATCC 6538, Corynebacterium diphtheriae ATCC 27010, C. diphtheriae ATCC 27012, and Mycobacterium abscessus, with inhibition halos of sizes 25, 36, 29, and 33 mm, respectively. To obtain secondary metabolites, the bacteria was subjected to submerged fermentation, and the metabolites were extracted using the liquid-liquid method with ethyl acetate. There was a similar MIC for M. abscessus and the two strains of C. diphtherium, reaching a concentration of 0.125 mg/mL, while that of S. aureus was 0.048 mg/mL. Assays for leishmanicidal activity and cytotoxicity against HEp-2 cells and red blood cells were performed. The metabolite showed IC50 of 9.0 ± 0.9 µg/mL and CC50 of 226.2 µg/ ml. This metabolite does not have hemolytic activity and is more selective for parasites than for mammalian cells, with a selectivity index of 24.85. Thus, the studied metabolite may be a strong candidate for the development of less-toxic drugs to treat diseases caused by pathogens.