First Report of Rhizoctonia solani AG-4 HG-I Causing Root and Basal Stem Rot on Roselle (Hibiscus sabdariffa) in Mexico.

Roselle (Hibiscus sabdariffa L.) is a crop of economic importance, refreshing drinks are prepared from its calyces, it is also attributed to antioxidant, antibacterial, and antihypertensive properties (Da-Costa-Rocha et al. 2014). In November 2022, in municipality of Iguala (18.355592N, 99.548546W, 749 m above sea level), Guerrero, México, roselle plants of approximately 1.5 months of age with basal rot were detected under greenhouse conditions. The symptoms consisted of wilting, yellowing, and root and stem rot with constriction in the base of the stem. The symptoms were detected in approximately 15% of plants at the operation. From symptomatic tissue, cuts were made into approximately 0.5 cm pieces, sterilized with 2% NaClO, washed with sterile distilled water, transferred to PDA medium amended with 50 mg/liter of Chloramphenicol, and incubated in the dark for four days at 28 °C. Rhizoctonia-like colonies were consistently obtained, and nine isolates were selected and purified by the hyphal-tip method. After four days, isolates developed a mycelium was light-white that became brown with age. Right-angled hyphal branching was also observed, in addition to a slight constriction at the base of the branches. In some older cultures, numerous dark brown sclerotia were observed. They were multinucleate cell with three to eight nuclei and measured from 1 to 2 mm in diameter. Together these characteristics were consistent with the description of Rhizoctonia solani Kühn (Parmeter 1970). The anastomosis group (AG) was confirmed by amplifying the ITS region with the primers ITS1 and ITS4 (White et al. 1990) of the RIJAM3 and RIJAM5 strains. The sequences were deposited in GenBank (Nos. OR364496 and OR364497 for RIJAM3 and RIJAM5, respectively). BLAST analysis, both isolates indicated 99.7 identity to R. solani AG-4 HG-I (GenBank: KM013470) strain ICMP 20043 (Ireland et al. 2015). The phylogenetic analysis of AGs sequences allowed assignment of isolates RIJAM3 and RIJAM5 to the AG-4 HG-1 clade. A pathogenicity test was performed on 20 one-month-old roselle plants. Mycelium of RIJAM3 isolate was inserted into the base of the stem with a sterile toothpick. As a control, a sterile toothpick with no mycelium was inserted in ten healthy plants. Additionally, 50 eight-day-old seedlings were inoculated by placing a 5-mm diameter agar plug colonized with mycelium of RIJAM3 at the base of the stem 10 mm below the soil surface. As control treatments, uncolonized PDA plugs were deposited at the base of 25 seedlings. The inoculated plants were incubated in a greenhouse with an average temperature and relative humidity of 28°C and 85%, respectively. Following inoculation, symptoms similar to those observed in the original outbreak were observed in plants after six days and only after four days in seedlings. In both experiments, the control plants and seedlings remained asymptomatic. R. solani was re-isolated from plants and seedlings, complying with Koch's postulates. The pathogenicity testing was repeated twice, with concordant results. In Nigeria and Malaysia R. solani was reported to seedling death to cause seedling dieback in roselle (Adeniji 1970; Eslaminejad and Zakaria 2011). In México R. solani AG-4 has been previously reported in crops of potato, chili and tomato (Montero-Tavera et al. 2013; Ortega-Acosta et al. 2022; Virgen-Calleros et al. 2000). To the best of our knowledge, this is the first report of R. solani AG-4 HG-I as a causing of root and basal stem rot on roselle in Mexico. This research provides information essential for informing the management of this disease, and may help design measures to prevent the spread of the pathogen to other regions.

Bacillus licheniformis M2-7 Decreases Ochratoxin A Concentrations in Coffee Beans During Storage.

Microbial contamination of coffee beans arises from various factors such as harvesting, handling, and storage practices, during which ochratoxin A (OTA)-producing fungi develop and proliferate. The presence of elevated concentrations of OTA poses a serious health risk to coffee consumers. Therefore, the implementation of a post-harvest treatment involving the use of bacteria known to antagonize OTA-producing fungi constitutes a safe alternative for reducing or eliminating the toxin's concentration in coffee beans. In this study, coffee beans (Coffea arabica L.) were inoculated with Bacillus licheniformis M2-7, after which we monitored fungal growth, in vitro antagonism, and OTA concentration. Our findings demonstrated that coffee beans inoculated with this bacterial strain exhibited a significant decrease in fungal populations belonging to the genera Aspergillus and Penicillium, which are known to produce OTA. Moreover, strain M2-7 decreased the growth rates of these fungi from 67.8% to 95.5% (P < 0.05). Similarly, inoculation with B. licheniformis strain M2-7 effectively reduced the OTA concentration from 24.35 ± 1.61 to 5.52 ± 1.69 µg/kg (P < 0.05) in stored coffee beans. These findings suggest that B. licheniformis M2-7 holds promise as a potential post-harvest treatment for coffee beans in storage, as it effectively inhibits the proliferation of OTA-producing fungi and lowers the toxin's concentration.

First report of Phyllosticta capitalensis causing brown spot disease on guava fruits (Psidium guajava) in Mexico.

The guava (Psidium guajava L.) is a plant native to the tropical region of America. In Mexico, the area established with guava cultivation is 20,525 ha (SIAP 2021). Guava is commonly consumed as fresh fruit, being rich in nutrients such as vitamins and minerals (Murthy et al. 2020). During October 2020, in the municipality of Cocula (18.207835N, 99.670322W, 595 m above sea level), Guerrero, Mexico, severely infected immature guava fruits were observed. The incidence of disease in 150 sampled fruits was 12%. Were collected fifteen symptomatic fruits. The symptoms were circular to irregular dark brown spots that varied in size (0.5 to 2.5 cm). From symptomatic fruits, tissues were cut approximately 3 x 3 mm and disinfested with 1% NaOCl, washed three times with sterile distilled water, and transferred to PDA medium amended with streptomycin and tetracycline, and incubated at 28°C. Developing colonies were retransferred to new culture PDA medium, and purified by hyphal tip technique. Two representative isolates (PHYGUA7 and PHYGUA3) were selected for morphological and molecular characterization. After 15 days in PDA at 28°C in an incubator, colonies were flat, irregular, granular and greenish gray, pycnidia were black, granular, and grouped. The conidia were hyaline and ellipsoid, unicellular and smooth-walled, 7-11×5-6.5 µm (n=50), these characteristics were consistent with those described for the fungus Phyllosticta capitalensis (Wikee et al. 2013). Molecular identification was performed by partially sequencing the internal transcribed spacer gene (ITS), the actin gene (ACT), and the translation elongation factor 1-alpha (EF-1α) gene, using primers ITS1 and ITS4, ACT-512F/ ACT-783R, and EF1-728F/EF1-986R, respectively (White et al. 1990; Carbone and Kohn 1999). The resulting sequences were deposited in GenBank (PHYGUA7: OP810947, PHYGUA3: OP810948 for ITS, PHYGUA7: OP819845, PHYGUA3: OP819846 for ACT, and PHYGUA7: OP819847, PHYGUA3: OP819848 for EF-1α). Phylogenetic analysis using maximum likelihood concatenated sequences ITS, ACT and EF-1α with MEGA X, indicated that PHYGUA7 and PHYGUA3 isolated grouped with P. capitalensis (CPC 18848 type strain). For pathogenicity test of P. capitalensis, 15 healthy immature fruits in a field experiment in the fruits on the trees, and 15 healthy mature guava fruits (detached fruits) were superficially disinfected with 70% ethanol, wounded with a sterile toothpick, and inoculated at two equidistant points by inserting PHYGUA7 isolate mycelium. As a control treatment, 10 healthy immature fruits and 10 healthy mature fruits were only injured with a sterile toothpick. After 3 days symptoms were observed in mature fruits and numerous dark pycnidia developed, and seven days later symptoms were observed in immature fruits in all the points inoculated with the PHYGUA7 isolate, similar to the symptoms observed in the field. The control fruits remained asymptomatic. The fungus P. capitalensis was re-isolated from inoculated fruits, thus confirming Koch's postulates. In Mexico P. capitalensis has been reported in Mangifera indica, Epidendrum sp., and Schomburgkia tibicinis (Farr and Rossman, 2022). In Egypt and China P. capitalensis causes black spot on guava fruits (Arafat 2016; Liao et al. 2020). To our knowledge, this is the first report of P. capitalensis as the cause of brown spot on immature guava fruit in Mexico. This research provides relevant information to the design of disease management strategies.

The catE gene of Bacillus licheniformis M2-7 is essential for growth in benzopyrene, and its expression is regulated by the Csr system.

Benzopyrene is a high-molecular-weight polycyclic aromatic hydrocarbon that is highly recalcitrant and induces carcinogenic effects. CsrA is a conserved regulatory protein that controls the translation and stability of its target transcripts, having negative or positive effects depending on the target mRNAs. It is known that Bacillus licheniformis M2-7 has the ability to grow and survive in certain concentrations of hydrocarbons such as benzopyrene, prompted in part by CsrA, as is present in gasoline. However, there are a few studies that reveal the genes involved in that process. To identify the genes involved in the Bacillus licheniformis M2-7 degradation pathway, the plasmid pCAT-sp containing a mutation in the catE gene was constructed and used to transform B. licheniformis M2-7 and generate a CAT1 strain. We determined the capacity of the mutant B. licheniformis (CAT1) to grow in the presence of glucose or benzopyrene as a carbon source. We observed that the CAT1 strain presented increased growth in the presence of glucose but a statistically considerable decrease in the presence of benzopyrene compared with the wild-type parental strain. Additionally, we demonstrated that the Csr system positively regulates its expression since it was observed that the expression of the gene in the mutant strain LYA12 (M2-7 csrA:: Sp, SpR) was considerably lower than that in the wild-type strain. We were thus able to propose a putative regulation model for catE gene in B. licheniformis M2-7 strain by CsrA regulator in the presence of benzopyrene.

Percepción de riesgos en la salud de la comunidad indígena Mixteca El Calvario, al sur de México / Perception of health risks in the Mixteca El Calvario indigenous community in southern Mexico

La situación de salud y percepción de riesgos de las comunidades indígenas se mide por el grado sociodemográfico y estudio etnográfico. Nuestra población en estudio “El Calvario” es la única comunidad indígena Mixteca de Chilpancingo, Guerrero, conformada por 21 familias que se dedican a la agricultura, producción de maguey y mezcal, y elaboración de algunas artesanías de palma. El objetivo fue estudiar las condiciones de Calidad de Vida y percepción de riesgos en dos grupos vulnerables adultos y niños. En el caso de los adultos, se hizo por encuestas y en el caso de los niños se usó el dibujo. En los habitantes se perciben en riesgos de salud y de perder su identidad indígena, debido a que solo hablan su lengua materna los adultos, no saben leer y ni escribir. Así mismo, es inminente el riesgo de sufrir daños materiales debido a que las viviendas no son adecuadas. La migración de jóvenes, la perdida de cultura, el padecer enfermedades metabólicas debido a la dieta alta en refrescos. Así mismo, los niños expresaron las deficiencias educativas. Finalmente, la población en general se encuentra olvidada por los organismos de gobierno actuales, en riesgo sanitario, y de perdida de cultura ya que los jóvenes migrarán a otros lugares a buscar nuevas oportunidades. Es un fuerte llamado de atención a la sociedad ya que, de no actuar en consecuencia con dicha problemática, se perdería la única comunidad Mixteca en Chilpancingo, Guerrero.(AU)

The health situation and risk perception of indigenous communities is measured by sociodemographic grade and ethnographic study. Our study population "El Calvario" is the only Mixtec indigenous community in Chilpancingo, Guerrero, made up of 21 families that are dedicated to agriculture, production of maguey and mezcal, and making some palm handicrafts. The objective was to study the conditions of Quality of Life and risk perception in two vulnerable groups, adults and children. In the case of adults, it was done through surveys and in the case of children, drawing was used. The inhabitants are perceived as being at risk of health and of losing their indigenous identity, because only adults speak their mother tongue, they do not know how to read and write. Likewise, the risk of suffering material damage is imminent due to the inadequate housing. The migration of young people, the loss of culture, suffering from metabolic diseases due to a diet high in soft drinks. Likewise, the children expressed educational deficiencies. Finally, the general population is forgotten by current government agencies, at risk of health, and loss of culture as young people will migrate to other places to seek new opportunities. It is a strong call for attention to society since, if it does not act accordingly, the only Mixtec community in Chilpancingo, Guerrero, would be lost.(AU)

Estrategias de recuperación de Agave cupreata (Asparagaceae) silvestres en una comunidad mixteca al sur de México / Recovery strategies of wild Agave cupreata (Asparagaceae) in a Mixtec community in southern Mexico

Se han documentado un sin número de incendios forestales y no forestales en todo el planeta, y también se han descrito las causas, y se habla mucho sobre los efectos colaterales que ocasionan al ambiente, a las especies nativas y al cambio climático, pero muy pocos se centran en propuestas claves de recuperación de las comunidades afectadas, es por ello que aquí se describen una serie de estrategias que se trabajaron con la comunidad desde la recuperación de semillas de agaves hasta una propuesta de comercialización de su producto, contando con estrategias amigables con el ambiente y como la misma naturaleza a un año del incendio se sobreponen algunas especies, esto servirá como base para otros grupos de investigación en potencializar a los ciudadanos a mejorar su entorno y dejar el miedo e incursionar en la comercialización de su mezcal artesanal.(AU)

A number of forest and non-forest fires have been documented across the planet, and the causes have also been described, and much is said about the side effects they cause to the environment, native species and climate change, but very few They focus on key proposals for recovery of the affected communities, which is why here a series of strategies that were worked with the community are described, from the recovery of agave seeds to a proposal for the commercialization of their product, counting on friendly strategies with the environment and as nature itself one year after the fire some species overlap, this will serve as the basis for other research groups to empower citizens to improve their environment and leave fear and venture into the commercialization of their artizanal mezcal.(AU)

Bioimmobilization of toxic metals by precipitation of carbonates using Sporosarcina luteola: An in vitro study and application to sulfide-bearing tailings.

Metal release from mining wastes is a major environmental problem affecting ecosystems that requires effective, low-cost strategies for prevention and reclamation. The capacity of two strains (UB3 and UB5) of Sporosarcina luteola was investigated to induce the sequestration of metals by precipitation of carbonates in vitro and under microcosm conditions. These strains carry the ureC gene and have high urease activity. Also, they are highly resistant to metals and have the capacity for producing metallophores and arsenophores. SEM, EDX and XRD reveal that the two strains induced precipitation of calcite, vaterite and magnesian calcite as well as several (M2+)CO3 such as hydromagnesite (Mg2+), rhodochrosite (Mn2+), cerussite (Pb2+), otavite (Cd2+), strontianite (Sr2+), witherite (Ba2+) and hydrozincite (Zn2+) in vitro. Inoculation of the mixed culture of UB3+UB5 in tailings increased the pH and induced the precipitation of vaterite, calcite and smithsonite enhancing biocementation and reducing pore size and permeability slowing down the oxidation of residual sulfides. Results further demonstrated that the strains of S. luteola immobilize bioavailable toxic elements through the precipitation and coprecipitation of thermodynamically stable (M2+)CO3, Fe-Mn oxyhydroxides and organic chelates.

Biotransformation of benzo[a]pyrene by the thermophilic bacterium Bacillus licheniformis M2-7.

Benzo[a]pyrene (BaP) is recognized as a potentially carcinogenic and mutagenic hydrocarbon, and thus, its removal from the environment is a priority. The use of thermophilic bacteria capable of biodegrading or biotransforming this compound to less toxic forms has been explored in recent decades, since it provides advantages compared to mesophilic organisms. This study assessed the biotransformation of BaP by the thermophilic bacterium Bacillus licheniformis M2-7. Our analysis of the biotransformation process mediated by strain M2-7 on BaP shows that it begins during the first 3 h of culture. The gas chromatogram of the compound produced shows a peak with a retention time of 17.38 min, and the mass spectra shows an approximate molecular ion of m/z 167, which coincides with the molecular weight of the chemical formula C6H4(COOH)2, confirming a chemical structure corresponding to phthalic acid. Catechol 2,3-dioxygenase (C23O) enzyme activity was detected in minimal saline medium supplemented with BaP (0.33 U mg-1 of protein). This finding suggests that B. licheniformis M2-7 uses the meta pathway for biodegrading BaP using the enzyme C23O, thereby generating phthalic acid as an intermediate.