Search Results (4)

TasA gene, encoding a functional amyloid protein critical for biofilm formation and antimicrobial activity, was cloned from the endophytic strain Bacillus amyloliquefaciens BS-3, isolated from rubber tree roots. This study identified the shortest functional TasA variant (483 bp, 160 aa) reported to date, featuring unique amino acid substitutions in conserved domains. Bioinformatics analysis predicted a signal peptide (1–27 aa) and transmembrane domain (7–29 aa), which were truncated to optimize heterologous expression. Two prokaryotic vectors (pET28a and pCZN1) were constructed, with pCZN1-TasA expressed solubly in Escherichia coli Arctic Express at 15 °C, while pET28a-TasA formed inclusion bodies at 37 °C. Purified recombinant TasA exhibited potent antifungal activity, achieving 98.6% ± 1.09 inhibition against Colletotrichum acutatum, 64.77% ± 1.34 against Alternaria heveae. Notably, TasA completely suppressed spore germination in C. acutatum and Oidium heveae Steinmannat 60 μg/mL. Structural analysis via AlphaFold3 revealed that truncation enhanced protein stability. These findings highlight BS-3-derived TasA as a promising biocontrol agent, providing molecular insights for developing protein-based biopesticides against rubber tree pathogens. Full article

Increasing antibiotic resistance is one of the world’s greatest health problems, and biocide use in food disinfection, alongside other application fields, could increase antibiotic resistance. Effective and eco-friendly food decontamination treatment with minimal chemical intervention in food production is urgently needed. Synergistic antimicrobial interaction of photoactive compounds and blue-light-emitting diodes have recently been proven effective in agricultural and environmental applications. Curcumin-based non-thermal treatment has been reviewed in this work for the development of a safe and effective decontamination tool that could be adapted to the food industry. The antimicrobial mechanism of the synergistic interaction and the inhibitory efficacy against foodborne pathogens (bacteria in both vegetative form and spore, as well as in biofilms) are discussed. Further studies on curcumin and its derivative, as well as light illumination patterns, were compared for enhanced bactericidal efficacy. Moreover, studies relating to photodynamic inactivation treatment for food sanitation and food quality enhancement (cereal grains and other food products) were summarized, as well as the impact on food organoleptic and nutritional quality. Full article

Bacteria growing inside biofilms are more resistant to hostile environments, conventional antibiotics, and mechanical stresses than their planktonic counterparts. It is estimated that more than 80% of microbial infections in human patients are biofilm-based, and biofouling induced by the biofilms of some bacteria causes serious ecological and economic problems throughout the world. Therefore, exploring highly effective anti-biofilm compounds has become an urgent demand for the medical and marine industries. Marine microorganisms, a well-documented and prolific source of natural products, provide an array of structurally distinct secondary metabolites with diverse biological activities. However, up to date, only a handful of anti-biofilm natural products derived from marine microorganisms have been reported. Meanwhile, it is worth noting that some promising antifouling (AF) compounds from marine microbes, particularly those that inhibit settlement of fouling invertebrate larvae and algal spores, can be considered as potential anti-biofilm agents owing to the well-known knowledge of the correlations between biofilm formation and the biofouling process of fouling organisms. In this review, a total of 112 anti-biofilm, anti-larval, and anti-algal natural products from marine microbes and 26 of their synthetic analogues are highlighted from 2000 to 2021. These compounds are introduced based on their microbial origins, and then categorized into the following different structural groups: fatty acids, butenolides, terpenoids, steroids, phenols, phenyl ethers, polyketides, alkaloids, flavonoids, amines, nucleosides, and peptides. The preliminary structure-activity relationships (SAR) of some important compounds are also briefly discussed. Finally, current challenges and future research perspectives are proposed based on opinions from many previous reviews. Full article

One of the main strategies for maintaining the optimal hygiene level in dairy processing facilities is regular cleaning and disinfection, which is incorporated in the cleaning-in-place (CIP) regimes. However, a frail point of the CIP procedures is their variable efficiency in eliminating biofilm bacteria. In the present study, we evaluated the susceptibility of strong biofilm-forming dairy Bacillus isolates to industrial cleaning procedures using two differently designed model systems. According to our results, the dairy-associated Bacillus isolates demonstrate a higher resistance to CIP procedures, compared to the non-dairy strain of B. subtilis. Notably, the tested dairy isolates are highly persistent to different parameters of the CIP operations, including the turbulent flow of liquid (up to 1 log), as well as the cleaning and disinfecting effects of commercial detergents (up to 2.3 log). Moreover, our observations indicate an enhanced resistance of poly-γ-glutamic acid (PGA)-overproducing B. subtilis, which produces high amounts of proteinaceous extracellular matrix, to the CIP procedures (about 0.7 log, compared to the wild-type non-dairy strain of B. subtilis). We therefore suggest that the enhanced resistance to the CIP procedures by the dairy Bacillus isolates can be attributed to robust biofilm formation. In addition, this study underlines the importance of evaluating the efficiency of commercial cleaning agents in relation to strong biofilm-forming bacteria, which are relevant to industrial conditions. Consequently, we believe that the findings of this study can facilitate the assessment and refining of the industrial CIP procedures. Full article