Bacterial wilt caused by Ralstonia spp., soil-borne Gram-negative bacteria, is considered one of the most important plant diseases in tropical and subtropical regions of the world. A large number of bacteriophages capable of lysing or physiologically reprogramming cells of Ralstonia spp. have been reported in Asia. Despite the potential use of these organisms in the management of bacterial wilt, information on viruses that infect Ralstonia spp. is nonexistent in the Americas. We isolated a virus that infects Ralstonia spp. from a soil sample in the state of Minas Gerais, Brazil. Microscopy and genomic and phylogenetic analysis allowed us to classify the virus as a member of the family Podoviridae, genus Phikmvvirus. In spite of its relationship to Ralstonia virus RSB3, an Asian isolate, genomic and biological characteristics showed that the virus isolated in Brazil, tentatively named "Ralstonia virus phiAP1" (phiAP1), belongs to a new species. phiAP1 has EPS depolymerase activity and contains two putative virion-associated peptidoglycan hydrolases (VAPGHs), which reveals a robust mechanism of pathogenesis. Furthermore, phiAP1 specifically infects Ralstonia solanacearum, R. pseudosolanacearum and R. syzygii, causing cell lysis, but it was not able to infect thirteen other bacteria that were tested. Together, these characteristics highlight the biotechnological potential of this virus for the management of bacterial wilt.

Fermented foods production started thousands of years ago and comprised a wide variety of products from different cultures and countries. The discovery of fermented foods is considered an empirical process based on human observation and experimentation of food types susceptible to natural biochemical and microbiological effects. Given the historical miscegenation of Brazilian people, the country has rich cultural diversity and a complex mix of ethnicities, religions and culinary traditions, among others. Thus, the current review aims at presenting the main cultural, microbiological and technological aspects of different types of fermented foods and beverages produced and consumed in Brazil, such as traditional artisanal cheeses, fermented meat (socol and charqui), non-alcoholic or low-alcohol beverages (aluá, calugi, tarubá and yakupá), alcoholic beverages (cachaça, tiquira, caiçuma, cauim and caxiri) and fermented foods based on cassava (puba, farinha d'água, polvilho azedo and tucupi).

Prophages are abundant elements integrated into bacterial genomes and contribute to inter-strain genetic variability and, in some cases, modulate the environmental behavior of bacteria, such as pathogen virulence. Here, we described prophage occurrence and diversity in publicly available Erwinia genome assemblies, a genus containing plant pathogens. Prophage-like sequences were identified and taxonomically classified. Sequence diversity was analyzed through intergenomic similarities. Furthermore, we searched for anti-phage defense systems in Erwinia spp., such as DISARM, BREX, and CRISPR-Cas systems, and identified the putative targets of CRISPR spacers. We identified 939 prophage-like sequences in 221 Erwinia spp. genome assemblies. Only 243 prophage-like sequences were classified, all belonging to the Caudoviricetes class. The set of putative Erwinia prophages was mostly unique since only three sequences showed more than 70% intergenomic similarities to known Erwinia phages. Overall, the number and type of CRISPR-Cas systems were conserved within Erwinia species, with many spacers directed to the putative prophages identified. This study increased the knowledge of the diversity and distribution of Erwinia prophages, contributing to the characterization of genetic and ecological factors influencing Erwinia spp. environmental fitness.

Artisanal cheeses are prepared using traditional methods with territorial, regional and cultural linkages. In Brazil, there is a great diversity of artisanal cheeses (BAC), which have historical, socioeconomic and cultural importance. The diversity of the BAC between producing regions is due to the different compositions of raw milk, the steps involved in the process and the maturation time. The crucial step for cheese differentiation is the non-addition of starter cultures, i.e., spontaneous fermentation, which relies on the indigenous microbiota present in the raw material or from the environment. Therefore, each BAC-producing region has a characteristic endogenous microbiota, composed mainly of lactic acid bacteria (LAB). These bacteria are responsible for the technological, sensory and safety characteristics of the BAC. In this review, the biotechnological applications of the LAB isolated from different BAC were evidenced, including proteolytic, lipolytic, antimicrobial and probiotic activities. In addition, challenges and opportunities in this field are highlighted, because there are knowledge gaps related to artisanal cheese-producing regions, as well as the biotechnological potential. Thus, this review may provide new insights into the biotechnological applications of LAB and guide further research for the cheese-making process.

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