This study analyzed the antifungal potential of 16 bacterial strains isolated from mangrove sediment. Bacterial selection was conducted in a solid medium. This was followed by the production and extraction of metabolites using ethyl acetate to evaluate chitinase production, antifungal activity, and toxicity toward Allium cepa and Tenebrio molitor. Bacterial strains B8, B11, and B13 produced the largest inhibition halos (>30 mm) toward Fusarium solani, Fusarium oxysporum, and Rhizoctonia solani fungi. Strains B1, B3, B6, B8, B11, B13, B14, and B16 produced chitinases. In assays using liquid media, B8 and B13 produced the largest inhibition halos. Exposing the fungal inocula to metabolic extracts of strains B6, B8, B11, B13, B14, B15, and B16 caused micromorphological alterations in the inocula, culminating in the inhibition of R. solani sporulation and spore germination. Toxicity tests using Allium cepa and Tenebrio molitor revealed that the metabolites showed low toxicity. Six of the bacterial strains were molecularly identified to species levels, and a further two to genus level. These included Serratia marcescens (B8), which exhibited activity in all tests. Mangroves provide a useful resource for the isolation of microorganisms for biocontrol. Among the isolates, Serratia marcescens and Bacillus spp. showed the greatest potential to produce metabolites for use as biocontrol agents in agriculture.

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.

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 genome sequencing as Streptomyces kronopolitis. A preliminary screening was carried out 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 were 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 12.5 µg/mL, while that of S. aureus was 0.048 µg/mL. Assays for leishmanicidal activity and cytotoxicity against HEp-2 cells and red blood cells were performed. The metabolite showed an IC₅₀ of 9.0 ± 0.9 µg/mL and CC₅₀ of 221.2 ± 7.0 µg/mL. This metabolite does not have hemolytic activity and is more selective for parasites than for mammalian cells, with a selectivity index of 24.6. Thus, the studied metabolite may be a strong candidate for the development of less toxic drugs to treat diseases caused by pathogens.

Introduction: Libraries are environments with high circulation and close contact among people, impacting human health and, therefore, must maintain good indoor air quality. This article aims to evaluate the environmental conditions of the air in air-conditioned libraries in São Luís (MA). Collections were made in 3 (three) large and easily accessible libraries, quantifying microorganisms (fungi and bacteria) and parameters such as temperature (T, °C), relative humidity (RH, %), carbon dioxide (CO2, ppm), and noise [dB(A)]. The data were analyzed and compared with specific legislation, according to the Resolution of the National Health Surveillance Agency (ANVISA). Sampling involved 10 (ten) equidistant points in the libraries, in four periods over 12 months. To quantify microorganisms, the deposition technique was used, where air particles settle on Petri dishes with selective medium for fungi and bacteria. The plates were exposed for 30 minutes and incubated at 27 ºC for 48 to 72 hours. All points were evaluated in triplicate, using Sabouraud Agar, Mueller Hinton Agar, and MacConkey Agar. After collection, colonies were quantified and purified in specific media using the streak plate method. The plates were incubated at 30 ºC for up to 48 hours for identification and association with ambient temperature and humidity. The results confirm the presence of microorganisms in these environments; however, in none of the analyzed points did the quantitative exceed the values allowed by current legislation. The research provides library managers with mitigating measures to preserve the collections and protect the health of occupants. Objective: The objective of this study is to investigate air quality, aiming to evaluate indoor air quality concerning microbiological parameters and comfort parameters (temperature, relative humidity, CO2, and noise level) in indoor environments. Theoretical Framework: This section presents the main concepts and theories that underpin the research. The theory of Sick Building Syndrome (SBS) described by the World Health Organization (WHO), which associates poor indoor air quality with various health problems, the model of monitoring physical-chemical and microbiological parameters in indoor environments, which includes the measurement of carbon dioxide (CO2), humidity, temperature, and noise, and the approach of correlating environmental conditions with the prevalence of microorganisms such as Aspergillus and Penicillium, providing a solid basis for understanding the context of the investigation. Method: The methodology adopted for this research comprises a descriptive observational study with a quantitative approach. The participants were libraries A, B, and C in the municipality of São Luís (MA). The instruments used included Petri dishes with different selective culture media for fungi and bacteria (Sabouraud Agar, Mueller Hinton Agar, and MacConkey Agar). The procedures involved exposing the plates to the indoor air of the libraries for 30 minutes, followed by incubation at 27 ºC for 48 to 72 hours. Data collection was carried out through sampling at ten equidistant points in the libraries in four distinct periods over 12 months. Results and Discussion: The results obtained revealed that the fungal count did not exceed the maximum value established by current legislation of 750 CFU/m³, and the main isolated genera were Candida spp., Aspergillus sp., and Penicillium sp. A significant correlation was observed between relative humidity and the presence of microorganisms. In the discussion section, these results are contextualized in light of the theoretical framework, highlighting the implications for health in library environments and the need for control measures. Possible discrepancies and limitations of the study are also considered in this section. Research Implications: The practical and theoretical implications of this research are discussed, providing insights into how the results can be applied or influence practices in the field of air quality control in libraries. These implications may include adopting preventive measures to keep microorganism levels within the limits allowed by legislation, implementing adequate ventilation systems, continuous monitoring of humidity and temperature, and guiding public policies aimed at occupational health and preservation of bibliographic collections. Originality/Value: This study contributes to the literature by investigating the microbiological quality of air in libraries, using a quantitative and innovative approach that integrates physical-chemical and microbiological parameters. The originality of the research lies in the combination of different collection and analysis methods in a specific and underexplored environment. The relevance and value of this research are evidenced by its implications for public health and the preservation of bibliographic collections, providing essential data for the implementation of environmental control policies and practices in libraries.