Limosilactobacillus fermentum (ATCC 23271) was originally isolated from the human intestine and has displayed antimicrobial activity, primarily against Candida species. Complete genome sequencing and comparative analyses were performed to elucidate the genetic basis underlying its probiotic potential. The ATCC 23271 genome was found to contain 2,193,335 bp, with 2123 protein-coding sequences. Phylogenetic analysis revealed that the ATCC 23271 strain shares 941 gene clusters with six other probiotic strains of L. fermentum. Putative genes known to confer probiotic properties have been identified in the genome, including genes related to adhesion, tolerance to acidic pH and bile salts, tolerance to oxidative stress, and metabolism and transport of sugars and other compounds. A search for bacteriocin genes revealed a sequence 48% similar to that of enterolysin A, a protein from Enterococcus faecalis. However, in vitro assays confirmed that the strain has inhibitory activity on the growth of Candida species and also interferes with their adhesion to HeLa cells. In silico analyses demonstrated a high probability of the protein with antimicrobial activity. Our data reveal the genome features of L. fermentum ATCC 23271, which may provide insight into its future use given the functional benefits, especially against Candida infections.

Surface-active compounds (SACs), biomolecules produced by bacteria, yeasts, and filamentous fungi, have interesting properties, such as the ability to interact with surfaces as well as hydrophobic or hydrophilic interfaces. Because of their advantages over other compounds, such as biodegradability, low toxicity, antimicrobial, and healing properties, SACs are attractive targets for research in various applications in medicine. As a result, a growing number of properties related to SAC production have been the subject of scientific research during the past decade, searching for potential future applications in biomedical, pharmaceutical, and therapeutic fields. This review aims to provide a comprehensive understanding of the potential of biosurfactants and emulsifiers as antimicrobials, modulators of virulence factors, anticancer agents, and wound healing agents in the field of biotechnology and biomedicine, to meet the increasing demand for safer medical and pharmacological therapies.

Surface-active compounds (SACs) of microbial origin are an active group of biomolecules with potential use in the formulation of emulsions. In this sense, the present study aimed to isolate and select yeasts from fruits that could produce SACs for essential oil emulsions. The Candida krusei M4CK was isolated from the Byrsonima crassifolia fruit to make SACs. This emulsification activity (E₂₄) was equal to or greater 50% in all carbon sources, such as olive oil, sunflower oil, kerosene, hexane, and hexadecane. E₂₄ followed exponential growth according to the growth phase. The stability of emulsions was maintained over a wide range of temperatures, pH, and salinity. The OMBE4CK (melaleuca essential oil emulsion) had better and more significant inhibitory potential for biofilm reduction formation. In addition, bioemulsifier BE4CK alone on Escherichia coli and Pseudomonas aeruginosa biofilm showed few effective results, while there was a significant eradication for Staphylococcus aureus biofilms. The biofilms formed by S. aureus were eradicated in all concentrations of OMBE4CK. At the same time, the preformed biofilm by E. coli and P. aeruginosa were removed entirely at concentrations of 25 mg/mL, 12.5 mg/mL, and 6.25 mg/mL. The results show that the bioemulsifier BE4CK may represent a new potential for antibiofilm application.

The objective of this study was to investigate the chemical composition of Syzygium aromaticum essential oil (SAEO), both as its toxicity and biological activities on Corynebacterium diphtheriae. The essential oil (EO) was obtained by hydrodistillation and verified by GC-MS. The main chemical components were eugenol (48.79%), caryophyllene (44.29%) and α-humulene (4.87%). In vitro tests with human red blood cells, blood compatibility. SAEO showed high toxicity for Artemia salina and the bioassay on Tenebrio molitor larvae revealed an average survival rate of 80.00%. The antioxidant activity of SAEO was moderate (40.60%) using the phosphomolybdenum method. SAEO inhibited the growth of all C. diphtheriae strains tested at minimum inhibitory concentrations of 62.5-1000 µg mL^-1 (strong to moderate). The minimum bactericidal concentration of SAEO was observed in two strains. Microorganisms cultivated in the presence of subinhibitory concentrations (subMIC) do not show morphological changes. The subMIC of SAEO inhibited in some strains, but in most cases, increased biofilm formation. In conclusion, the results of this study found that SAEO has an inhibitory effect against C. diphtheriae, representing an alternative antimicrobial therapy, although more in vivo biological studies, alone or in combination with occasional antimicrobials, should be carried out to better evaluate its effects.

Objective: The objective of this study is to analyze the action of Melaleuca essential oil emulsion on two isolates of Klebsiella pneumoniae as a new alternative. Theoretical Framework: K. pneumoniae resistance to antibiotics is an urgent public health problem. Melaleuca alternifolia oil appears as a promising therapeutic alternative, with potential to combat the bacteria. Method: The methodology adopted for this research includes evaluating the minimum inhibitory concentration of the isolates, evaluating the elimination time of microorganisms by Time kill curve, biofilm formation and biofilm eradication. Results and Discussion: The results obtained revealed that Melaleuca alternifolia oil together with a bioemulsifier appears as a promising therapeutic alternative, with the potential to combat the bacteria and save lives. More research is needed, but the future of medicine against bacterial resistance may lie in the power of nature. Implications of the Research: The research demonstrates the effectiveness of Melaleuca essential oil emulsion together with a bioemulsifier in combating multi-resistant Klebsiella pneumoniae. This discovery is crucial for public health as it offers a promising alternative to traditional antibiotics, which are becoming increasingly less effective due to bacterial resistance. Originality/Value: Research on Melaleuca essential oil emulsion together with a bioemulsifier to combat multi-resistant Klebsiella pneumoniae presents significant originality and value for public health.

Mangroves are areas of sediment transitions, favoring the cycling of materials associated with high concentration of microorganisms, presenting vulnerability to anthropogenic actions. The objective of this study was to evaluate the ability of microbiota in mangrove sediments of the Anil River, in the city of São Luís, Maranhão. To produce surface active compounds (SACs), samples were collected according to the EMBRAPA methodology by inoculating them in the Bushnell Haas medium, with carbon sources varying at 3% (v/v). From the production obtained, the supernatants of each culture were submitted to E24 analysis, drop spreading, thermal stability/pressure and pH variation. The SAC-producing species were identified using the MALDI-QTOF MS method. The producing species were identified as Serratia marcescens (2), Ochrobactrum spp. (3). E24 values ranged from 33% to 48% yield, with stability increase after autoclaving of 3% to 6% and of 17% for basic pH ranges, demonstrating the feasibility of using regional microorganisms present in mangroves to produce SACs from different carbon sources, as they have good rates of emulsification and stability to the diverse environmental factors.