We assessed the fungal and fungal-like sequence diversity present in marine sediments obtained in the vicinity of the South Shetland Islands (Southern Ocean) using DNA metabarcoding through ...high-throughput sequencing (HTS). A total of 193,436 DNA reads were detected in sediment obtained from three locations: Walker Bay (Livingston Island) at 52 m depth (48,112 reads), Whalers Bay (Deception Island) at 151 m (104,704) and English Strait at 404 m (40,620). The DNA sequence reads were assigned to 133 distinct fungal amplicon sequence variants (ASVs) representing the phyla Ascomycota, Basidiomycota, Mortierellomycota, Chytridiomycota, Glomeromycota, Monoblepharomycota, Mucoromycota and Rozellomycota and the fungal-like Straminopila. Thelebolus balaustiformis, Pseudogymnoascus sp., Fungi sp. 1, Ciliophora sp., Agaricomycetes sp. and Chaetoceros sp. were the dominant assigned taxa. Thirty-eight fungal ASVs could only be assigned to higher taxonomic levels, and may represent taxa not currently included in the available databases or represent new taxa and/or new records for Antarctica. The total fungal community displayed high indices of diversity, richness and moderate to low dominance. However, diversity and taxa distribution varied across the three sampling sites. In Walker Bay, unidentified fungi were dominant in the sequence assemblage. Whalers Bay sediment was dominated by Antarctic endemic and cold-adapted taxa. Sediment from English Strait was dominated by Ciliophora sp. and Chaetoceros sp. These fungal assemblages were dominated by saprotrophic, plant and animal pathogenic and symbiotic taxa. The detection of an apparently rich and diverse fungal community in these marine sediments reinforces the need for further studies to characterize their richness, functional ecology and potential biotechnological applications.
In association with lichens, bacteria can play key roles in solubilizing sources of inorganic phosphates that are available in the environment. In this study, the potential of bacteria isolated from ...15 Antarctic lichen samples for phosphate solubilization was investigated. From 124 bacteria tested, 66 (53%) were positive for phosphate solubilization in solid NBRIP medium, with a higher prevalence of
Pseudomonas
, followed by
Caballeronia
and
Chryseobacterium
. Most of the phosphate-solubilizing bacteria were isolated from
Usnea auratiacoatra
, followed by
Caloplaca regalis
and
Xanthoria candelaria
. Two isolates showed outstanding performance,
Pseudomonas
sp. 11.LB15 and
Pseudomonas
sp. 1.LB34, since they presented solubilization in the temperature range from 15.0 to 30.0 °C, and maximum quantification of soluble phosphate at 25.0 °C was 511.21 and 532.07 mg/L for
Pseudomonas
sp. 11.LB15 and
Pseudomonas
sp. 1.LB34, respectively. At 30.0 °C soluble phosphate yield was 639.43 and 518.95 mg/L with pH of 3.74 and 3.87 for
Pseudomonas
sp. 11.LB15 and
Pseudomonas
sp. 1.LB34, respectively. Fumaric and tartaric acids were released during the solubilization process. Finally, bacteria isolated from Antarctic lichens were shown to have the potential for phosphate solubilization, opening perspectives for future application in the agricultural sector and contributing to reduce the use of chemical fertilizers.
In the Antarctic environment, yeasts are versatile eukaryotes that have shown wide dispersion in different substrates, producing active enzymes in extreme conditions, but their relevance in ...biotechnological applications is largely unknown. The aim of this study was to evaluate the production of extracellular hydrolases by yeasts isolated from Antarctic lichens and molecularly identify these isolates. From a total of 144 isolates on the screening, 109 (76%) produced at least one of the hydrolases tested, with most activities for proteases 59 (41%), cellulases 58 (40%), esterases 57 (39%), lipases 29 (20%), amylases 23 (16%) and pectinases 20 (14%). Among these isolates, 76 were identified, most belonged to the phylum Basidiomycota (n=73) with the dominance of Vishniacozyma victoriae (n=27), Cystobasidium alpinum (n=3), Mrakia niccombsii (n=3), Cystobasidium laryngis (n=2), Bannozyma yamatoana (n=2), Holtermanniella nyarrowii (n=2), and Glaciozyma martinii (n=2). This study is the first one reporting extracellular enzyme production by yeasts isolated from thallus of the species of Antarctic lichens Lecania brialmontii, Polycauliona candelaria, Usnea capillacea, Cladonia metacorallifera, and Polycauliona regalis. With these data, it's possible to confirm lichens as a source of hydrolase-producing yeasts, reinforcing the potential of these microorganisms in bioprospecting studies of catalytic molecules from polar regions that may be useful in promising biotechnological applications.
As abordagens tradicionais de ensino tendem a ser menos estimulantes e de maior dificuldade de compreensão, principalmente ao tratar-se de assuntos mais distantes da realidade dos alunos e, de certa ...forma, abstratos, como alguns conceitos de Microbiologia. Tal realidade reforça a importância do estudo e aplicação de novas formas de ensino no ambiente escolar. Nesse sentido, o objetivo deste artigo é relatar a experiência de ações de extensão realizadas com o tema “Dia do Cientista”, nas quais os métodos utilizados foram baseados no protagonismo dos alunos, através da participação ativa em experimentos, discussões e visitações. Ao longo da execução das ações, observou-se o despertar do interesse em assuntos até então desconhecidos e distantes da realidade dos estudantes do Ensino Fundamental I (4.º e 5.º ano), que puderam reconhecer o que a Microbiologia representa no seu cotidiano, a partir da execução de atividades práticas, como: I) Detecção de microrganismos em diferentes espaços da escola, como salas de aula e dos professores, banheiros e pátio; II) “Carimbo de mãos”; III) Utilização de fermento biológico para o crescimento microbiano e IV) Visita à Universidade Federal de Alagoas - Campus Arapiraca, onde puderam conhecer laboratórios de ensino prático do tema. Dessa forma, percebeu-se que estratégias com abordagens ativas e práticas auxiliaram numa maior interação dos alunos com os temas propostos, além de aguçar a curiosidade, estimular o aprendizado e permitir maior crescimento pessoal por parte dos escolares, bem como de todos os participantes do projeto.
Palavras-chave: Extensão comunitária; Ensino; Aprendizagem
Socialization of microbiology concepts in elementary school through practical activities
Abstract: Traditional teaching approaches tend to be less stimulating and more difficult to understand, especially when dealing with subjects that are more distant from the reality of students and, in a way, abstract, such as some topics of microbiology. This reality reinforces the importance of studying and applying new forms of teaching in the school environment. In this sense, the objective of this article is to report the experience of extension actions carried out with the theme "Scientist's Day", in which the methods used were based on the protagonism of the students, through active participation in experiments, discussions, and visits. Throughout the actions, it was possible to notice an awakening of interest in subjects previously unknown and distant from the reality of the students at elementary school (4th and 5th), who were able to recognize what microbiology represents in their daily lives, from the execution of practical activities such as I) Detection of microorganisms in different locations of the school, such as classrooms and teachers’ room, bathrooms and courtyard; II) "Hand Stamp"; III) Use of biological yeast for microbial growth and IV) Visit to the Federal University of Alagoas - Campus Arapiraca (Arapiraca, Brazil), where they got to know the laboratories. Therefore, it was noticed that strategies with active and practical approaches made the interaction of students with the proposed themes easier, besides to whet curiosity, stimulate learning and allow greater personal growth by the schoolers, as well as all the participants of the project.
Keywords: Community extension; Teaching; Learning
We studied the culturable fungal community recovered from deep marine sediments in the maritime Antarctic, and assessed their capabilities to produce exoenzymes, emulsifiers and metabolites with ...phytotoxic activity. Sixty-eight
Ascomycota
fungal isolates were recovered and identified. The most abundant taxon recovered was the yeast
Meyerozyma guilliermondii
, followed by the filamentous fungi
Penicillium chrysogenum
,
P.
cf.
palitans
,
Pseudeurotium
cf.
bakeri
,
Thelebolus balaustiformis
,
Antarctomyces psychrotrophicus
and
Cladosporium
sp. Diversity indices displayed low values overall, with the highest values obtained at shallow depth, decreasing to the deepest location sampled. Only
M
.
guilliermondii
and
P
. cf.
palitans
were detected in the sediments at all depths sampled, and were the most abundant taxa at all sample sites. The most abundant enzymes detected were proteases, followed by invertases, cellulases, lipases, carrageenases, agarases, pectinases and esterases. Four isolates showed good biosurfactant activity, particularly the endemic species
A. psychrotrophicus
. Twenty-four isolates of
P.
cf.
palitans
displayed strong phytotoxic activities against the models
Lactuca sativa
and
Allium schoenoprasum
. The cultivable fungi recovered demonstrated good biosynthetic activity in the production of hydrolytic exoenzymes, biosurfactant molecules and metabolites with phytotoxic activity, reinforcing the importance of documenting the taxonomic, ecological and biotechnological properties of fungi present in deep oceanic sediments of the Southern Ocean.
Antarctica has a great diversity of microorganisms with biotechnological potential but is not very well Known about yeasts with phosphate solubilization activity. Thus, the aim of this study was to ...evaluate the ability of yeasts from Antarctica lichens to solubilize phosphate in vitro. In the screening, 147 yeasts were tested and 43 (29%) showed P solubilization in solid NBRIP medium at 15.0 °C, with a higher prevalence of positive genera
Vishniacozyma
, followed by
Cystobasidium
. Most of the positive yeasts were isolated from
Usnea auratiacoatra
, followed by
Polycauliona regalis
and
Lecania brialmontii
. Two strains with better activity after screening were selected for the solubilization in the liquid medium,
Vishniacozyma victoriae
2.L15 and A.L6 (unidentified).
Vishniacozyma victoriae
2.L15 exhibiting activities at 25.0 °C (29.91 mg/L of phosphate and pH 6.85) and at 30.0 °C (619.04 mg/L of phosphate and pH 3.73) and A.L6 strain at 25.0 °C (25.05 mg/L of phosphate and pH 6.69) and at 30.0 °C (31.25 mg/L of phosphate and pH 6.47). Of eight organic acids tested by HPLC, tartaric and acetic acids were detected during phosphate solubilization, with greater release in the period of 144 (2.13 mg/L) and 72 (13.72 mg/L) hours, respectively. Future studies to elucidate the presence of functional genes for P metabolism in lichens, as well as studies in the field of proteomics for the discovery of yeast proteins related to P solubilization are needed. Thus, the high prevalence of lichen-associated yeast communities probably contributed to the high frequency of phosphate-solubilizing isolates in this study.
Graphical abstract
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