Xanthomonas albilineans (Xa) and X. sacchari (Xs) are both sugarcane pathogens. Xa is the causal agent of leaf scald disease, but there is limited information about the pathogenicity of Xs. The aim of this work was to study virulence factors of native strains of Xa (Xa32, Xa33, and XaM6) and Xs (Xs14 and Xs15) previously isolated from sugarcane with leaf scald symptoms, to gain insight into the biology of each microorganism. We analysed epiphytic survival, sensitivity to oxidative stress, extracellular degradative enzymes, cell motilities, exopolysaccharide (EPS) characteristics, cell adhesion, biofilm development, and control of stomatal regulation of the five strains. We observed that each species presented similar phenotypes for every factor analysed. Xa strains appeared to be more sensitive to oxidative stress and presented lower epiphytic survival than Xs. All strains presented endoglucanase activity; however, we could only detect protease and amylase activities in Xs strains. Swimming and sliding were higher in Xs, but twitching was variable among species. We also observed that only Xs strains produced a xanthan‐like EPS, presented a strong cell adhesion, and structured biofilm. We detected some intraspecific variations showing that higher amounts of EPS produced by Xs14 correlated with its higher sliding motility and its homogenous and more adhesive biofilm. In addition, EPSs of Xs14 and Xs15 presented differences in strand height and acetyl percentage. Finally, we found that strains of both species were able to interfere with stomatal aperture mechanism. All these differences could influence the colonization strategies and/or disease progression in each species.

Omega-3 eicosapentaenoic fatty acid (C20:5; EPA), β-glucan and fucoxanthin have received widespread attention owing to their potential industrial applications; however, their availability is currently limited to unsustainable sources such as fish oils and macroalgae. Though some species of diatoms are also a natural source of these metabolites, progress needs to be made in reducing the cost barriers involved in their large-scale production. The aim of the present study was therefore to assess the potential of the marine diatom Halamphora coffeaeformis to simultaneously accumulate EPA, chrysolaminarin and fucoxanthin in a raceway pond sustained by fertilizer (Bayfolan®)-enriched seawater. The biomass production increased significantly along the experiment, the specific growth rate, biomass productivity and areal yield being 2.03 day −1 , 0.128 g.L − 1.d −1 and 25.73 g.m −2 .d −1 , respectively. Proteins dominated in the first culture phase, while lipids, carbohydrates and pigments increased toward the end of the stationary phase. The harvested biomass presented 310 mg.g −1 DW (dry weight) of total lipids containing high amounts of EPA (24% of total fatty acids), 114 mg.g −1 DW of chrysolaminarin and 38 mg.g −1 DW of fucoxanthin. These values compare favorably with those obtained from commercially used sources. The culture medium proposed represents a non-conventional, cost-effective resource allowing for sustained high biomass levels throughout 22 days, guaranteeing the accumulation of valuable metabolites. Furthermore, the robustness and auto-flocculation capacity of the species increase the chances of viable scalability. These findings indicate the potential of H.coffeaeformis as a high-value metabolite feedstock, focusing on sustainable bioprocesses.