In Vitro Analysis of the Antagonistic Biological and Chemical Interactions between the Endophyte Sordaria tomento-alba and the Phytopathogen Botrytis cinerea.

Plant pathogenic infections causing substantial global food losses are a persistent challenge. This study investigates a potential biocontrol strategy against the necrotrophic fungus Botrytis cinerea using the endophytic fungus Sordaria tomento-alba isolated from Gliricidia sepium in Colombia. Today, synthetic fungicides dominate B. cinerea control, raising environmental and health concerns. S. tomento-alba exhibits notable in vitro effects, inhibiting B. cinerea growth by approximately 60% during co-culture and 50% in double disc co-culture. Additionally, it suppresses botryanes production and produces the compound heptacyclosordariolone, which has proven effective in inhibiting B. cinerea mycelial growth and spore germination in vitro. This biocontrol agent could be a potential eco-friendly alternative to replace synthetic fungicides. Our study provides insights into the chemical and biological mechanisms underpinning the antagonistic activity of S. tomento-alba, emphasizing the need for further research to understand its biosynthesis pathways and optimize its biocontrol potential. It also contributes molecular evidence of fungal interactions with implications for advanced forums in molecular studies in biology and chemistry, particularly in addressing plant pathogenic infections and promoting sustainable agriculture.

Halotolerant Endophytic Bacteria Priestia flexa 7BS3110 with Hg2+ Tolerance Isolated from Avicennia germinans in a Caribbean Mangrove from Colombia.

The mangrove ecosystems of the Department of Atlántico (Colombian Caribbean) are seriously threatened by problems of hypersalinization and contamination, especially by heavy metals from the Magdalena River. The mangrove plants have developed various mechanisms to adapt to these stressful conditions, as well as the associated microbial populations that favor their growth. In the present work, the tolerance and detoxification capacity to heavy metals, especially to mercury, of a halotolerant endophytic bacterium isolated from the species Avicennia germinans located in the Balboa Swamp in the Department of Atlántico was characterized. Diverse microorganisms were isolated from superficially sterilized A. germinans leaves. Tolerance to NaCl was evaluated for each of the obtained isolates, and the most resistant was selected to assess its tolerance to Pb2+, Cu2+, Hg2+, Cr3+, Co2+, Ni2+, Zn2+, and Cd2+, many of which have been detected in high concentrations in the area of study. According to the ANI and AAI percentages, the most halotolerant strain was identified as Priestia flexa, named P. flexa 7BS3110, which was able to tolerate up to 12.5% (w/v) NaCl and presented a minimum inhibitory concentrations (MICs) of 0.25 mM for Hg, 10 mM for Pb, and 15 mM for Cr3+. The annotation of the P. flexa 7BS3110 genome revealed the presence of protein sequences associated with exopolysaccharide (EPS) production, thiol biosynthesis, specific proteins for chrome efflux, non-specific proteins for lead efflux, and processes associated with sulfur and iron homeostasis. Scanning electron microscopy (SEM) analysis showed morphological cellular changes and the transmission electron microscopy (TEM) showed an electrodense extracellular layer when exposed to 0.25 mM Hg2+. Due to the high tolerance of P. flexa 7BS3110 to Hg2+ and NaCl, its ability to grow when exposed to both stressors was tested, and it was able to thrive in the presence of 5% (w/v) NaCl and 0.25 mM of Hg2+. In addition, it was able to remove 98% of Hg2+ from the medium when exposed to a concentration of 14 mg/L of this metalloid. P. flexa 7BS3110 has the potential to bioremediate Hg2+ halophilic contaminated ecosystems.

In Vitro Studies of Endophytic Bacteria Isolated from Ginger (Zingiber officinale) as Potential Plant-Growth-Promoting and Biocontrol Agents against Botrytis cinerea and Colletotrichum acutatum.

Agriculture currently confronts a multitude of challenges arising from the excessive utilization of chemical pesticides and the proliferation of phytopathogenic fungi strains that exhibit resistance to commonly employed active compounds in the field. Botrytis cinerea and Colletotrichum acutatum are phytopathogenic fungi that inflict substantial economic losses within agriculture and food due to their high impacts on crops both pre- and post-harvest. Furthermore, the emergence of fungal strains that are resistant to commercial fungicides has exacerbated this problem. To explore more environmentally sustainable alternatives for the control of these pathogens, an investigation into the endophytic bacteria associated with ginger (Zingiber officinale Rosc.) was conducted. The primary focus of this study involved evaluating their inhibitory efficacy against the fungi and assessing their potential for promoting plant growth. The endophytic bacteria genera Lelliottia, Lysinibacillus, Kocuria, Agrococcus, Acinetobacter, Agrobacterium, Zymobacter, and Mycolicibacterium were identified. All isolates showed remarkable in vitro antagonistic ability against B. cinerea (>94%) and C. acutatum (>74%). Notably, the Lelliottia amnigena J29 strain exhibited a notable proficiency in producing extracellular enzymes and indole compounds (IAA), solubilizing phosphate and potassium, and forming biofilm. Furthermore, the Lysinibacillus capsici J26, Agrococcus citreus J28, and Mycolicibacterium sp. J5 strains displayed the capacity for atmospheric nitrogen fixation and siderophore production. These findings underscore the agricultural and biotechnological potential of endophytic bacteria derived from ginger plants and suggest the feasibility of developing alternative approaches to manage these two phytopathogenic fungi.

Endophytic Bacteria Bacillus subtilis, Isolated from Zea mays, as Potential Biocontrol Agent against Botrytis cinerea.

Plant diseases are one of the main factors responsible for food loss in the world, and 20-40% of such loss is caused by pathogenic infections. Botrytis cinerea is the most widely studied necrotrophic phytopathogenic fungus. It is responsible for incalculable economic losses due to the large number of host plants affected. Today, B. cinerea is controlled mainly by synthetic fungicides whose frequent application increases risk of resistance, thus making them unsustainable in terms of the environment and human health. In the search for new alternatives for the biocontrol of this pathogen, the use of endophytic microorganisms and their metabolites has gained momentum in recent years. In this work, we isolated endophytic bacteria from Zea mays cultivated in Colombia. Several strains of Bacillus subtilis, isolated and characterized in this work, exhibited growth inhibition against B. cinerea of more than 40% in in vitro cultures. These strains were characterized by studying several of their biochemical properties, such as production of lipopeptides, potassium solubilization, proteolytic and amylolytic capacity, production of siderophores, biofilm assays, and so on. We also analyzed: (i) its capacity to promote maize growth (Zea mays) in vivo, and (ii) its capacity to biocontrol B. cinerea during in vivo infection in plants (Phaseolus vulgaris).

Beach litter distribution in Admiralty Bay, King George Island, Antarctica.

In the Antarctic Peninsula, most important activities are touristic visits, from the second half of the 20th Century, and scientific investigation linked to 75 research stations. Beach litter content/abundance was investigated at 17 beaches in Admiralty Bay (King George Island, Antarctica) and the type of plastic material was determined by Raman spectroscopy. An average value of 0.16 items m-1 was observed. Wood items consisted of processed wood fragments representing 47.27% of the total. Foam represented 21%, hard plastic pieces 9.68% (consisting of polyvinyl chloride or high density polyethylene), metal 3.37%, rubber fragments 2.81%, foamed plastic pieces 2.66% (composed by polystyrene), the rest of categories representing less than 2% of the total. Wood debris and metal are essentially remnant objects of ancient whaling activities and research expeditions, polyurethane and expanded polystyrene materials have different origins and hard plastic, rubber, paper/cardboard and paint fragments seem mostly linked to present research activities.

Microbiological water quality and sources of contamination along the coast of the Department of Atlántico (Caribbean Sea of Colombia). Preliminary results.

Microbiological sea water quality is a public health problem that has serious repercussions in the tourism and economy of Colombia. This study determines the concentrations of Escherichia coli, Enterococcus faecalis and Clostridium perfringens at eleven beach water points and seven streams along the coast of the Department of Atlántico, Colombia. In seawater, total E. coli, E. faecalis and C. perfringens concentrations were found between 16 and 572 cfu/100 mL, 7-450 cfu/100 ml and 2-125 cfu/100 ml, respectively. The highest counts were observed mainly on urbanised beaches and in correspondence with streams whose waters had a high concentration of faecal origin microorganisms, which represent a serious health risk factor for bathers. Relevant efforts have to be addressed to improve the microbiological quality of these beaches by the establishment of efficient wastewater management programs aimed at enhancing the efficiency of the local treatment plant and the control of illegal sewage pouring onto the coast.

Molecular detection of Salmonella spp., Listeria spp. and Brucella spp. in fresh artisanal cheese marketed in the city of Barranquilla: A pilot study

Introduction: Each year approximately 3 million people die as the result of foodborne diseases. The fresh artisan (handmade) cheese produced and distributed in the Colombian Caribbean region is a native product from the departments of Córdoba, Sucre, Bolívar, Atlántico, Magdalena, Cesar, and La Guajira. Its mass consumption increases the risk of infection with Salmonella spp., Listeria spp., and Brucella spp., as it is made with a very rustic technology, with unpasteurized cow milk, without standardized and hygienic procedures and its storage is inadequate. Objective: To detect the presence of Salmonella spp., Listeria spp., and Brucella spp. in samples of fresh artisan cheese from the Colombian Caribbean region. Materials and methods: Twenty-seven samples of cheese from five departments of the Caribbean Region (Atlántico (n=6), Bolívar (n=2), Córdoba (n=1), Magdalena (n=16), and Sucre (n=2)) were analyzed by real-time polymerase chain reaction (qPCR). Seventeen of the samples corresponded to soft cheese, five to semi-hard cheese and five to hard cheese. Results: In 62.9% (17/27) of the samples we detected Salmonella spp., in 70.4% (19/27), Listeria spp., and in 22.2% (6/27), Brucella spp., mainly from the department of Magdalena. In 62.5% (10/16) of the samples we detected Salmonella spp. and Listeria spp. while in the department of Atlántico, 50% (3/6) of the samples corresponded to Brucella spp. Conclusion: The results confirmed the presence of these microorganisms in all the samples of soft cheese from the Colombian Caribbean region.

Detección molecular de Salmonella spp., Listeria spp. y Brucella spp. en queso artesanal fresco comercializado en Barranquilla: un estudio piloto / Molecular detection of Salmonella spp., Listeria spp. and Brucella spp. in fresh artisanal cheese marketed in the city of Barranquilla: A pilot study

Introducción. Cada año mueren, aproximadamente, tres millones de personas como consecuencia de las enfermedades transmitidas por alimentos. El queso artesanal fresco que se produce y distribuye en la región Caribe colombiana es un producto autóctono de los departamentos de Córdoba, Sucre, Bolívar, Atlántico, Magdalena, Cesar y La Guajira. Su consumo masivo aumenta el riesgo de infección con salmonelosis, listeriosis y brucelosis debido a que es elaborado con una tecnología muy rústica, con leche de vaca no pasteurizada, sin procedimientos estandarizados e higiénicos, y a que su almacenamiento no es adecuado. Objetivo. Detectar la presencia de Salmonella spp., Listeria spp. y Brucella spp. en muestras de queso artesanal costeño fresco procedente de los departamentos de la región Caribe colombiana. Materiales y métodos. Mediante reacción en cadena de la polimerasa en tiempo real (qPCR), se analizaron 27 muestras de queso proveniente de cinco departamentos de la región Caribe: Atlántico (n=6), Bolívar (n=2), Córdoba (n=1), Magdalena (n=16) y Sucre (n=2). Del total de las muestras, 17 eran de queso blando, cinco de queso semiduro y cinco de queso duro. Resultados. En el 62,9 % de las muestras se detectó Salmonella spp. (17/27), en el 70,4 %, Listeria spp. (19/27), y en el 22,2 %, Brucella spp. (6/27). Las muestras provenían principalmente del departamento del Magdalena y, en 62,5 % (10/16) de ellas, se encontró Salmonella spp. y Listeria spp., en tanto que en el 50 % (3/6) de las muestras del departamento del Atlántico se detectó Brucella spp. Conclusión. Los resultados evidenciaron la presencia de estos microorganismos en todas las muestras de queso costeño blando.

Introduction: Each year approximately 3 million people die as the result of foodborne diseases. The fresh artisan (handmade) cheese produced and distributed in the Colombian Caribbean region is a native product from the departments of Córdoba, Sucre, Bolívar, Atlántico, Magdalena, Cesar, and La Guajira. Its mass consumption increases the risk of infection with Salmonella spp., Listeria spp., and Brucella spp., as it is made with a very rustic technology, with unpasteurized cow milk, without standardized and hygienic procedures and its storage is inadequate. Objective: To detect the presence of Salmonella spp., Listeria spp., and Brucella spp. in samples of fresh artisan cheese from the Colombian Caribbean region. Materials and methods: Twenty-seven samples of cheese from five departments of the Caribbean Region (Atlántico (n=6), Bolívar (n=2), Córdoba (n=1), Magdalena (n=16), and Sucre (n=2)) were analyzed by real-time polymerase chain reaction (qPCR). Seventeen of the samples corresponded to soft cheese, five to semi-hard cheese and five to hard cheese. Results: In 62.9% (17/27) of the samples we detected Salmonella spp., in 70.4% (19/27), Listeria spp., and in 22.2% (6/27), Brucella spp., mainly from the department of Magdalena. In 62.5% (10/16) of the samples we detected Salmonella spp. and Listeria spp. while in the department of Atlántico, 50% (3/6) of the samples corresponded to Brucella spp. Conclusion: The results confirmed the presence of these microorganisms in all the samples of soft cheese from the Colombian Caribbean region.