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Rare and unknown actinobacteria from unexplored environments have the potential to produce new bioactive molecules. This study aimed to use 16 s rRNA metabarcoding to determine the composition of the actinobacterial community, particularly focusing on rare and undescribed species, in a nature reserve within the Brazilian Cerrado called Sete Cidades National Park. Since this is an inaccessible area without due legal authorization, it is understudied, and, therefore, its diversity and biotechnological potential are not yet fully understood, and it may harbor species with groundbreaking genetic potential. In total, 543 operational taxonomic units (OTUs) across 14 phyla were detected, with Actinobacteria (41.2%), Proteobacteria (26.5%), and Acidobacteria (14.3%) being the most abundant. Within Actinobacteria, 107 OTUs were found, primarily from the families Mycobacteriaceae, Pseudonocardiaceae, and Streptomycetaceae. Mycobacterium and Streptomyces were the predominant genera across all samples. Seventeen rare OTUs with relative abundance < 0.1% were identified, with 82.3% found in only one sample yet 25.5% detected in all units. Notable rare and transient genera included Salinibacterium, Nocardia, Actinomycetospora_01, Saccharopolyspora, Sporichthya, and Nonomuraea. The high diversity and distribution of Actinobacteria OTUs indicate the area's potential for discovering new rare species. Intensified prospection on underexplored environments and characterization of their actinobacterial diversity could lead to the discovery of new species capable of generating innovative natural products.

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Specimens of Leptogium collected in ten localities from the State of Rio Grande do Sul were studied. Sixteen species were found of 28 records mentioned to the state, which represents around 57% of the Leptogium diversity known for Rio Grande do Sul. Leptogium exaratum is proposed as a new species. Leptogium atlanticum, L. milligranum and L. vesiculosum are reported for the first time to the state. The lectotype of L. javanicum is reported here and detailed descriptions are provided to the examined specimens. An identification key is showed with all the 28 mentioned species of Leptogium. It is the first published taxonomic key for Leptogium from Rio Grande do Sul, the State with the highest diversity of this genus in Brazil.

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Air pollution and the urban heat island effect are known to directly affect ecosystems in urban areas. Lichens, which are widely known as good ecological indicators of air quality and of climatic conditions, can be a valuable tool to monitor environmental changes in urban environments. The objective of this work was to select lichen functional traits and functional groups that can be used as ecological indicators of the effects of urbanization, with emphasis in the Southern subtropics, where this had never been done. For that, we assessed lichen functional composition in urban sites with different population density, which was considered as proxy for grouping sites in two levels of urbanization (low and medium/high). This a priori grouping was based on their significantly differences on air pollutants and land cover. Urbanization and air pollution showed to affect all lichen functional traits, with different responses depending on the functional group. Medium/high density urbanization was associated to an increase on the mean relative abundance of lichens with chlorococcoid green algae, foliose narrow lobes, soredia as the main reproduction strategy, pruinose thallus and containing secondary metabolites for chemical protection. Lower density urbanization showed a higher relative frequency of cyanolichens and lichens with Trentepohlia as the main algae, loosely attached crustose thallus and isidia as the main reproductive structure. The differences found on photobiont and growth form traits in response to the environmental variables used as proxies of microclimatic conditions (forest cover and number of trees around the sampling units), enabled us to detect the urban heat island effect (drier conditions in more urbanized sites).

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Based on the need to monitor air pollution and on the importance of doing it with biological organisms, the present work had as main objective to assess air quality in urban areas through lichen transplants. Besides, we also tested whether there were differences among the studied sites, aiming to point out the main pollution characteristics of the areas. The monitoring was carried out in seven cities, which varied from mainly rural to mainly industrial, in Rio Grande do Sul, southern Brazil. The foliose lichen Parmotrema tinctorum was used as the biomonitor species. Physiological tests and contents of sulphur and heavy metals were measured in the lichen thalli. Other pollutants assessed through air samplers were available for some cities, and modeled concentrations of fine particulate matter and nitrogen oxides for all sites. The effect of air pollution negatively reflected on the physiology parameters of the lichen and the concentration of all heavy metals increased after exposure, especially in the industrial sites. We generated a profile of air pollutants and pointed out that Charqueadas and Esteio had the worst air quality. Since they have high demographic densities, the results are of great public health concern and could be guidelines for future studies.

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The use of lichens as ecological surrogates has been an important tool to evaluate the impact of air pollution in both ecosystem and human health but remains underused in the subtropics due to lack of knowledge. Aiming to support the application of lichen as ecological surrogates of the effects of air pollution in the subtropics, we hypothesized that urbanization was an important driver of changes on lichen diversity, composition, and vitality. For that, we quantified several lichen diversity metrics (richness, cover, and community composition) and photobiont vitality in relation to atmospheric pollution or its surrogates (modeled pollutant gases, pollutants in lichen thallus, and land cover). We confirmed that air pollution was a key driver for lichen diversity. Changes in lichen community composition and vitality were very significantly related to air pollution and integrated the effect of multiple stressors (particulate matter, NOx, and Cu), thus being powerful ecological indicators of air pollution in the subtropics.

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There is currently an intense debate in microbial societies on whether evolution in complex communities is driven by competition or cooperation. Since Darwin, competition for scarce food resources has been considered the main ecological interaction shaping population dynamics and community structure both in vivo and in vitro. However, facilitation may be widespread across several animal and plant species. This could also be true in microbial strains growing under environmental stress. Pure and mixed strains of Serratia marcescens and Candida rugosa were grown in mineral culture media containing phenol. Growth rates were estimated as the angular coefficients computed from linearized growth curves. Fitness index was estimated as the quotient between growth rates computed for lineages grown in isolation and in mixed cultures. The growth rates were significantly higher in associated cultures than in pure cultures and fitness index was greater than 1 for both microbial species showing that the interaction between Serratia marcescens and Candida rugosa yielded more efficient phenol utilization by both lineages. This result corroborates the hypothesis that facilitation between microbial strains can increase their fitness and performance in environmental bioremediation.

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Ethanol produced by the fermentation of sugarcane juice has emerged as an important renewable fuel. The yield of this fermentation is affected by undesirable microbial contaminants, but killer yeasts can be a promising strategy to reduce this problem. The present study aimed to isolate, characterize, and identify wild killer yeasts from sugarcane juice. Samples were inoculated in culture medium containing chloramphenicol, and 140 colonies with different characteristics were selected. These isolates were submitted to the killer phenotype assay, and the positive killers were characterized and identified according to the standard methods. Only two strains showed killer activity, identified as Pichia anomala CE025 and P. membranaefaciens CE088. At 25C, both strains exhibited killer activity at pH 4.0, 4.3, and 4.5, but this activity was not detected at pH 3.0, 3.5, 5.0, and 6.0. The killer phenotype of P. membranaefaciens CE088 was inhibited above 30C, while for P. anomala, CE025 inhibition occurred only at a higher temperature. Both strains were able to grow in 12% ethanol, and P. anomala CE025 was more tolerant than P. membranaefaciens CE 088. Further studies will be conducted to isolate, purify and identify the killer toxins produced by Pichia anomala and Pichia membranaefaciens species.(AU)

O etanol produzido a partir da fermentação do caldo de cana emergiu como um combustível renovável. O rendimento desta fermentação é afetado por micro-organismos indesejáveis e as leveduras killer se constituem uma alternativa promissora para combater essa contaminação. Nesta perspectiva, o presente trabalho teve como objetivo isolar, caracterizar e identificar leveduras killer de caldo de cana. As amostras foram inoculadas em meio de cultura contendo cloranfenicol e 140 colônias com diferentes características foram selecionadas. Esses isolados foram avaliados quanto à presença do fator killer e os isolados positivos caracterizados e identificados por métodos convencionais. Apenas dois isolados apresentaram atividade killer e foram identificados como Pichia anomala CE025 e P. membranaefaciens CE088. A 25C as duas linhagens exibiram atividade killer em pH 4.0, 4.3 e 4.5, mas esta atividade foi inibida a pH 3.0, 3.5, 5.0 e 6.0. Para P. membranaefaciens CE088 o fenótipo killer foi inibido acima de 30C, enquanto que a P. anomala CE025 exibiu essa característica acima deste valor. Ambas as linhagens foram capazes de crescer na presença de 12% de etanol, mas P. anomala CE025 foi mais tolerante do que P. membranaefaciens CE088. Estudos posteriores serão realizados para isolar, purificar e identificar as toxinas killer produzidas pelas espécies Pichia anomala e Pichia membranaefacien.(AU)

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Bactérias do ácido láctico (BAL) se constituem o principal grupo contaminante das fermentações alcoólicas. Esses micro-organismos consomem o açúcar que seria transformado em álcool, resultando na produção de metabólitos que alteram o desenvolvimento do processo. Também flocu- Iam as leveduras obstruindo equipamentos, reduzindo o rendimento e a qualidade do produto final. Os antibióticos estão entre as substâncias usadas para o controle dessa contaminação e, embora eficientes, promovem a seleção de linhagens resistentes o que limita o uso das mesmas. Nesse contexto, este trabalho teve por objetivo isolar, caracterizar e avaliar a susceptibilidade de linhagens de bactérias lácticas oriundas das principais etapas do processo fermentativo para produção de aguardente. Foram utilizados discos com penicilina-G (10 ug), antibiótico inibidor da síntese da parede celular, e discos com tetraciclina (30 ug) e cloranfenicol (30 ug), ambos inibidores da produção de proteínas. Referidos antibióticos são amplamente utilizados nas fermentações alcoólicas. Para avaliação da susceptibilidade foi usada à técnica de difusão em Ágar Muller-Hinton. Foram selecionadas 20 colônias do meio ágar MRS, que apresentaram características morfológicas e bioquímicas típicas de Lactobacillus (85%) enquanto (15%) foram cocos Gram positivos em pares e tétrades. O crescimento escasso e irregular dos isolados no meio Ágar Muller- -Hinton não permitiu uma conclusão decisiva sobre a susceptibilidade aos antibióticos testados. Tendo em vista o uso de antibióticos como agente de controle microbiano nas fermentações industriais, este resultado evidencia a necessidade da padronização de um método para monitorar a resistência de linhagens BAL provenientes desses processos. (AU)

Lactic acid bacteria (LAB) comprise the main contaminant group of alcoholic fermentations. These microorganisms consume the sugar that would be transformed to alcohol, resulting in the production of metabolites that alter the development processo Also flocculate yeast clogging equipment, reducing the yield and quality of the final product. Antibiotics are among the substances used to control this contamination, and although efficient, promote the selection of resistant strains which limits the use of the compounds. In this context, this study aimed to isolate, characterize and assess the susceptibility of lactic acid bacteria strains from the main stages of the alcoholic fermentation process for the production of aguardente. The disks were penicillin G (10 units], antibiotic inhibitor of cell wall synthesis, and discs with tetracycline (30 J.1g) and chloramphenicol (30 ug}, both inhibitors of protein production. These antibiotics are widely used in industrial fermentations. To evaluate the susceptibility was used to agar diffusion technique. Twenty colonies were selected from MRS medium and characterized as Lactobacillus (85%) and Gram positive cocci in pairs and tetrads (15%). The sparse and irregular growth of the isolates in Mueller-Hinton agar could not establish. the susceptibillty of isolates to antibiotics tested. In view of the use of antibiotics as a microbial control agent in industrial fermentations, this result shows the need for standardizing a method for monitoring the resistance of BAL strains. (AU)

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