Genetic Screens Identify Additional Genes Implicated in Envelope Remodeling during the Engulfment Stage of Bacillus subtilis Sporulation.

During bacterial endospore formation, the developing spore is internalized into the mother cell through a phagocytic-like process called engulfment, which involves synthesis and hydrolysis of peptidoglycan. Engulfment peptidoglycan hydrolysis requires the widely conserved and well-characterized DMP complex, composed of SpoIID, SpoIIM, and SpoIIP. In contrast, although peptidoglycan synthesis has been implicated in engulfment, the protein players involved are less well defined. The widely conserved SpoIIIAH-SpoIIQ interaction is also required for engulfment efficiency, functioning like a ratchet to promote membrane migration around the forespore. Here, we screened for additional factors required for engulfment using transposon sequencing in Bacillus subtilis mutants with mild engulfment defects. We discovered that YrvJ, a peptidoglycan hydrolase, and the MurA paralog MurAB, involved in peptidoglycan precursor synthesis, are required for efficient engulfment. Cytological analyses suggest that both factors are important for engulfment when the DMP complex is compromised and that MurAB is additionally required when the SpoIIIAH-SpoIIQ ratchet is abolished. Interestingly, despite the importance of MurAB for sporulation in B. subtilis, phylogenetic analyses of MurA paralogs indicate that there is no correlation between sporulation and the number of MurA paralogs and further reveal the existence of a third MurA paralog, MurAC, within the Firmicutes. Collectively, our studies identify two new factors that are required for efficient envelop remodeling during sporulation and highlight the importance of peptidoglycan precursor synthesis for efficient engulfment in B. subtilis and likely other endospore-forming bacteria. IMPORTANCE In bacteria, cell envelope remodeling is critical for cell growth and division. This is also the case during the development of bacteria into highly resistant endospores (spores), known as sporulation. During sporulation, the developing spore becomes internalized inside the mother cell through a phagocytic-like process called engulfment, which is essential to form the cell envelope of the spore. Engulfment involves both the synthesis and hydrolysis of peptidoglycan and the stabilization of migrating membranes around the developing spore. Importantly, although peptidoglycan synthesis has been implicated during engulfment, the specific genes that contribute to this molecular element of engulfment have remained unclear. Our study identifies two new factors that are required for efficient envelope remodeling during engulfment and emphasizes the importance of peptidoglycan precursor synthesis for efficient engulfment in the model organism Bacillus subtilis and likely other endospore-forming bacteria. Finally, our work highlights the power of synthetic screens to reveal additional genes that contribute to essential processes during sporulation

Small-scale marine fisheries in the municipal district of Florianópolis, Santa Catarina, Brazil

The objective of this paper is to describe the main characteristics of small-scale marine fisheries in the municipal district of Florianópolis (SC), the capital city of the state of Santa Catarina. We give information about the most captured species, the fishing fleet and fishing gear used. The dynamics of the activity is described, considering the kind of operation of the boats, alongside post-capture procedures. The analyses were accomplished in two types of fishing communities: the one composed of fishers that fish in bays (North and South) and those who fish in the open sea. Numeric differences were observed among these two fishing areas, indicating the existence of two different fleets operating in the area. Differences between the two fishing areas were detected, considering the species caught, the harvest time and the fishing gear used. The open sea fishers have boats with dimensions, engine power, number of crew and fuel consumption numerically higher than those working in bays, indicating the existence of two distinct fleets operating in the region.Este trabalho teve como objetivo caracterizar a pesca de pequena escala no município de Florianópolis (SC). São apresentadas informações sobre as principais espécies capturadas, sobre a frota e artes de pesca utilizadas, sobre a dinâmica da atividade, considerando a forma de operação das unidades produtivas, e sobre os procedimentos pós-captura adotados. As análises foram realizadas em dois tipos de comunidades pesqueiras: as compostas por pescadores que atuam em baías e aquelas cujos integrantes pescam em mar aberto. Foram detectadas diferenças entre as duas áreas de pesca considerando as espécies capturadas, as épocas de captura e as artes de pesca utilizadas. Os pescadores de mar aberto possuem embarcações com dimensões, potência dos motores, número de tripulantes e consumo de combustível numericamente superiores aos que atuam nas baías, indicando a existência de duas frotas distintas operando na região

Ação conjunta de citocinina, giberelina e auxina em pimentão enxertado e não enxertado sob cultivo protegido

O objetivo deste trabalho foi avaliar o efeito da utilização do bioestimulante Stimulate® em plantas de pimentão enxertadas e não enxertadas, em ambiente protegido, no aumento de produção. Utilizou-se o delineamento experimental de blocos casualizados, no esquema fatorial 2 x 6, referente a plantas enxertadas e pé-franco e seis doses do Stimulate® (0; 75; 100; 125; 150 e 175 mL p.c. 100 L H2O-1), com quatro repetições. Realizaram-se sete aplicações foliares, quinzenais, do bioestimulante a partir do início do florescimento das plantas e avaliou-se o número total de frutos comerciais produzidos, comprimento, calibre, espessura de parede, massa média e produtividade final, totalizando treze colheitas. As plantas enxertadas foram mais produtivas em relação às plantas pé-franco, produzindo frutos de características agronômicas superiores. No geral, 100 e 125-150 mL p.c. 100 L H2O-1 de Stimulate® promovem incremento na produção de pimentão enxertado e pé-franco, respectivamente.The objective of this study was to evaluate the effect of using the Stimulate® biostimulant in grafted and non grafted plants of sweet pepper in a protected environment, to increase production. The experimental design was randomized blocks in a factorial scheme 2 x 6, referring to the grafted and non grafted plants and six doses of Stimulate® (0; 75; 100; 125; 150 and 175 mL p.c. 100 L H2O-1), with four replications. Seven foliar applications of the biostimulant were carried out fortnightly, from the beginning of the plants flowering and the total number of marketable fruits, length, diameter, wall thickness, average weight and final yield were evaluated, totalling thirteen harvests. The grafted plants were more productive than the non-grafted ones, producing fruits with better agronomic characteristics. In general, 100 and 125-150 mL p.c. 100 L H2O-1 of Stimulate® promoted an increase in the production of grafted and non-grafted sweet pepper plants, respectively