Tapping into Tapajos: antibacterial potential of fungal strains isolated from decaying wood in the Brazilian Amazon.

The emergence of bacterial resistance to antimicrobials poses a significant health threat. To address this issue, exploring the fungal diversity in freshwater environments in the Amazon Forest has potential in the search for new antimicrobials. This study aimed to investigate the production of antibacterial metabolites by aquatic fungi from Amazon lakes, specifically Lake Juá and Lake Maicá (Brazil-PA). The fungal isolates were obtained from wood fragments submerged in these lakes, and the ethyl acetate extracts were evaluated for antibacterial activity against Staphylococcus aureus ATCC 25923, S. aureus (MRSA), ATCC 43300, Escherichia coli ATCC 25922, and E. coli (ESBL) NCTC 13353. Additionally, toxicity of the extracts (EtOAc with antimicrobial activity) against human fibroblasts MRC-5 was investigated. The study identified 40 fungal strains with antimicrobial screening, and the ethyl acetate extracts of Fluviatispora C34, Helicascus C18, Monodictys C15, and Fusarium solani LM6281 exhibited antibacterial activity. F. solani LM6281 showed the lowest minimum inhibitory concentration (MIC) of 50 µg/mL against S. aureus strains and MIC of 100 µg/mL against E. coli strains including ESBL. The cytotoxicity (IC50) of the extract (EtOAc) of F. solani LM6281 was 34.5 µg/mL. Preliminary studies of the TLC culture and RNM-H from the extract (EtOAc) of F. solani suggested the presence of substances from the class of terpenes, quinones, phenolics, and flavonoids. This study highlights the potential of submerged wood fungi in the Amazon region to produce antibacterial substances, thus identifying them as sources of novel bioactive compounds with potential use in the pharmaceutical industry and regional bioeconomy.

Qualidade do leite cru refrigerado sob inspeção federal na região Nordeste / Quality of bulk tank milk with federal inspection from the dairy industry in the Brazilian Northeast

Estudou-se a influência sazonal sobre a composição química, a contagem de células somáticas (CCS) e a contagem bacteriana total (CBT) de leite cru refrigerado em vários estados da região Nordeste. Os dados foram obtidos de 116.989 amostras de leite de tanques coletadas pelas indústrias com cadastro no serviço de inspeção federal. As amostras foram separadas em três períodos (I, II, III), de acordo com aplicação da Instrução Normativa-51 (IN-51). O teor de gordura, média de 3,7%, foi o componente do leite que apresentou maior variação. Proteína e lactose tiveram amplitude de 0,04% entre os períodos e apresentaram médias de 3,2 e 4,4%, respectivamente. Maiores valores de CCS foram observados entre os meses de maio e julho, 594,33 a 625,28 mil cel/mL, enquanto para CBT os maiores valores ocorreram nos meses de maio e junho, 1308,54 e 1333,83 UFC/mL. Observaram-se diferenças significativas nos componentes do leite entre os estados, principalmente no que se refere à qualidade higiênico-sanitária.

The aim was to study seasonal influence on the chemical composition, somatic cell count (SCC) and total bacteria count (TBC) in bulk tank milk in the Brazilian Northeast. The data analyzed was obtained from 116.989 samples of bulk tank milk collected from industries that have an account at the Federal Inspection Service (FIS). The samples were separated into three periods (I,II,III), according to application of IN-51. PROC GLM was used to study the comparison of means by Duncan's test. The fat varied more, with an average of 3.66%, protein and lactose had an amplitude of 0.04% between periods, and an average of 3.16 and 4.41%, respectively. Higher values of SCC were observed in the months from May to July (594.33 to 625.28 thousand cells/mL), while in TBC the largest values occurred in May and June (1308.54 and 1333.83 CFU/mL). Significant differences in milk components between states were observed, especially with regard to hygienic quality. The chemical composition, SCC and TBC were influenced between periods and months of the year.