The macroalgae consortium biomass in the Mexican Caribbean represents an emerging and promising biofuel feedstock. Its biological pretreatment and potential for energetic conversion to biomethane were investigated, since some macroalgae have hard cell walls that present an obstacle to efficient methane production when those substrates are used. It has been revealed by anaerobic digestion assays that pretreatment with a Bm-2 strain (Trametes hirsuta) isolated from decaying wood in Yucatan, Mexico was 104 L CH₄ kg·VS⁻¹; In fact, the fungal pretreatment produced a 20% increase in methane yield, with important amounts of alkali metals Ca, K, Mg, Na of 78 g/L, ash 35.5% and lignin 15.6%. It is unlikely that high concentrations of ash and alkali metals will produce an ideal feedstock for combustion or pyrolysis, but they can be recommended for a biological process.

Anthracnose, caused by Colletotrichum truncatum (syn. C. capsici), has become a common disease of tropical crops, severely affecting the quantity and quality of fruit and seed and, therefore, reducing their market value. For years, chemical control has been extensively used for managing this disease. However, the appearance of isolates that are resistant to the most commonly employed fungicides is increasingly widespread. Twenty C. truncatum isolates from pepper, papaya, and physic nut were tested in vitro against four fungicides to determine their sensitivity. All evaluated isolates were resistant to azoxystrobin and thiabendazole and susceptible to cyprodinil + fludioxonil and mancozeb. To determine the molecular mechanism conferring thiabendazole resistance, the TUB-2 gene was characterized, revealing a glutamic acid to alanine substitution at position 198 in 6 of the 20 isolates that were tested. This work confirms the emergence of benzimidazole-based fungicide resistance in C. truncatum populations and highlights the need for monitoring fungicide sensitivity as an essential activity for the development of effective control schemes.

Papaya meleira virus (PMeV) is the causal agent of papaya sticky disease, which is characterized by a spontaneous exudation of fluid and aqueous latex from the papaya fruit and leaves. The latex oxidizes after atmospheric exposure, resulting in a sticky feature on the fruit from which the name of the disease originates. PMeV is an isometric virus particle with a double-stranded RNA (dsRNA) genome of approximately 12 Kb. Unusual for a plant virus, PMeV particles are localized on and linked to the polymers present in the latex. The ability of the PMeV to inhabit such a hostile environment demonstrates an intriguing interaction of the virus with the papaya. A hypersensitivity response is triggered against PMeV infection, and there is a reduction in the proteolytic activity of papaya latex during sticky disease. In papaya leaf tissues, stress responsive proteins, mostly calreticulin and proteasome-related proteins, are up regulated and proteins related to metabolism are down-regulated. Additionally, PMeV modifies the transcription of several miRNAs involved in the modulation of genes related to the ubiquitin-proteasome system. Until now, no PMeV resistant papaya genotype has been identified and roguing is the only viral control strategy available. However, a single inoculation of papaya plants with PMeV dsRNA delayed the progress of viral infection.