Luis E Fuentes-Ramirez

• PhD
• Researcher at Meritorious Autonomous University of Puebla

Recibido: 01 junio 2022. Aceptado: 5 septiembre 2022 RESUMEN La adición de fertilizantes nitrogenados, pesticidas y herbicidas en los cultivos agrícolas, ha traído enormes consecuencias para el ambiente y la salud de los organismos terrestres. Las bacterias promotoras del crecimiento de plantas podrían ser una alternativa para evitar el uso de esos...

Rare-earth elements (REEs) are a group of metallic chemical elements that share some properties and that despite their name are not too rare in the Earth’s crust. Until recently, we did not know of any REEs that were necessary for any living organism. Now we know that there are some bacteria that use REEs to perform reactions that let them consume...

Rhizosphere soil samples of three Pinus chiapensis sites were analyzed for their physicochemical properties, soil bacteria isolated and screened in vitro for growthpromoting abilities. Nine isolates that showed promise were identified to five genera Dyella, Luteimonas, Enterobacter, Paraburkholderia and Bacillus based on the sequences of 16S rRNA g...

Azotobacter vineladii is a Gram-negative bacterium that produces alginate and poly-hydroxybutyrate (PHB), two polymers of biotechnological interest. This bacterium has the ability to form desiccation-resistant cysts. In the cyst the membrane phospholipids are replaced with a family of phenolic lipids called alkylresorcinols (ARs). The alginate, PHB...

Carta aclaratoria de primer autor y responsable de la patente MX340596B Primer autor: Yolanda Elizabeth Morales García Autor responsable: Jesús Muñoz-Rojas

A random transposition mutant library of B. gladioli UAPS07070 was analyzed for searching mutants with impaired microbial antagonism. Three derivates showed diminished antimicrobial activity against a sensitive strain. The mutated loci showed high similarity to the quorum sensing genes of the AHL-synthase and its regulator. Another mutant was affec...

A random transposition mutant library of B. gladioli UAPS07070 was analyzed for searching mutants with impaired microbial antagonism. Three derivates showed diminished antimicrobial activity against a sensitive strain. The mutated loci showed high similarity to the quorum sensing genes of the AHL-synthase and its regulator. Another mutant was affec...

Invitation to submit articles to the Research Topic on plant-bacteria /Archea interactions in arid and semi-arid lands. Frontiers in Microbiology https://www.frontiersin.org/research-topics/9612/plant-bacteria-and-plant-archaea-associations-in-arid-and-semi-arid-zones

The GacS/A system in Azotobacter vinelandii regulates alginate and alkylresorcinols production through RsmZ1, a small regulatory RNA (sRNA) that releases the translational repression of the algD and arpR mRNAs caused by the RsmA protein. In the Pseudomonadaceae family, the Rsm-sRNAs are grouped into three families: RsmX, RmsY and RsmZ. Besides RsmZ...

Rotatory image of July number of G3 Genes Genomics Genetics

One of the most commonly used tools to compare protein or DNA sequences against databases is BLAST. We introduce a web tool that allows the performance of BLAST-searches of protein/DNA sequences in whole-genome sequenced bacteria/archaea, and displays a large amount of BLAST-results simultaneously. The circular bacterial replicons are projected as...

Plant growth-promoting rhizobacteria (PGPR) increase plant growth and crop productivity. The inoculation of plants with a bacterial mixture (consortium) apparently provides greater benefits to plant growth than inoculation with a single bacterial strain. In the present work, a bacterial consortium was formulated containing four compatible and desic...

Bacterial growth in SYP or PY-Ca liquid media for bacteria grown individually or all together. (PDF)

Physicochemical characteristics of the soils used for support in the desiccation experiments. (PDF)

Siderophore production of the four strains chosen for the bacterial consortium. (PDF)

Sequence identity of 16S rRNA from Acinetobacter sp. strain EMM02. (DOCX)

Number of bacteria present in suspensions used for the inoculation of maize. (DOCX)

Colonization of the rhizosphere of maize plants by the bacterial strains. (DOCX)

Flow chart illustrating the identification of Acinetobacter sp. EMM02 by the amplification and sequencing of the gene encoding 16S rRNA. (PDF)

Restriction patterns of the amplified gene encoding the 16S rRNA of the bacterial strains isolated from plants. (PDF)

Adhesion of strains to maize seeds sown in vermiculite. (DOCX)

Strains used in this study. (DOCX)

Methanol-consuming culturable bacteria were isolated from the plant surface, rhizosphere, and inside the stem of Neobuxbaumia macrocephala. All 38 isolates were facultative methylotrophic microorganisms. Their classification included the Classes Actinobacteria, Sphingobacteriia, Alpha-, Beta-, and Gammaproteobacteria. The deduced amino acid sequenc...

Mexican food is made with various natural products. The objective of the present work was to make a reflection on the natural components used to prepare the typical Mexican food and to make known which of them contain compounds with antimicrobial capacity. It was noticed that many of the natural ingredients of the typical Mexican food have compound...

Azotobacter vinelandii is a soil bacterium that forms desiccation-resistant cysts, and the exopolysaccharide alginate is essential for this process. A. vinelandii also produces alginate under vegetative growth conditions, and this production has biotechnological significance. Poly-β-hydroxybutyrate (PHB) is another polymer synthetized by A. vinelan...

La presente invención contempla una formulación bacteriana que contiene 6 cepas bacterianas diferentes, con capacidad de promoción de crecimiento para plantas de interés agrícola y/o bioremediación. La formulación es designada como EMMIM-1 y promueve el crecimiento de plantas de maíz y otras de interés agrícola. Para la realización de esta formulac...

Pink disease is an asymptomatic pineapple disease in the field and is evidenced with a reddark coloration when the infected fruit is processed to obtain products such as juice, jam, and preservatives. Tatumella morbirosei and T. ptyseos (formerly Pantoea citrea) have been demonstrated as causal agents. Although T. morbirosei and T. ptyseos have bee...

It has been established that a decrease in the population of Gluconacetobacter diazotrophicus associated with sugarcane occurs after nitrogen fertilization. This fact could be due to a direct influence of NH4NO3 on bacterial cells or to changes in plant physiology after fertilizer addition, affecting bacterial establishment. In this work, we observ...

Pineapple is the second most important tropical fruit in international trade and Mexico ranks ninth in world production. Pink disease is asymptomatic in the field and is characterized by the production of dark discoloration (amber-reddish brown) and its initial effects are not recognized until the fruits are cored and canned. Hence pink disease is...

We evaluate the arbuscular mycorrhizal fungi (AMF) community as measured by spores in different coffee production systems (at the depth of 0–15 cm). In addition, we analyze the similarities between the AMF communities in coffee production systems and those that occur in a tropical montane cloud forest patch in order to evaluate the capacity of coff...

Diversity and abundance of arbuscular mycorrhizal fungi spores under different coffee production systems and in a tropical montane cloud forest patch in Veracruz,

A maize rhizosphere isolate was phenotypically and genotypically characterized and identified as Enterobacter spp. bacterium. Germinated seeds were inoculated, the plantlets were sown in vermiculite and in soil and grown under laboratory and field conditions, respectively. The adherence, colonization and plant growth promotion capability of Enterob...

Gluconacetobacter diazotrophicus is a nitrogen-fixing bacterium and endophyte of sugarcane, which expresses levansucrase, a fructosyltransferase exoenzyme with sucrose hydrolytic and levan biosynthetic activities. As a result of their physical properties, the levan can provide protection against stress caused by abiotic or biotic factors and partic...

Azotobacter vinelandii is a soil bacterium that produces the polysaccharide alginate. The two-component system GacS/GacA is required for alginate synthesis since a mutation in gacS or gacA significantly reduced the level of transcripts of algD, the gene encoding GDP-mannose dehydrogenase, a key enzyme of the alginate biosynthetic pathway. In many γ...

Pink disease is a major problem in the pineapple canning industry. Affected fruit acquire a brownish pigment after pasteurization and can contaminate non-affected fruit before they are released to the consumer. In the last few years, Pantoea citrea has been described as the causative agent of pink disease. In this study, over 300 bacterial isolates...

The degradation of two immobilized dyes by Klebsiella sp. UAP-b5 was studied. In batch experiments, the azo dyestuffs Basic Blue 41 and Reactive Black 5 were immobilized onto corn cobs by adsorption, and the adsorption process was characterized by a pseudo-second-order kinetic equation. Klebsiella sp. UAP-b5 was previously isolated from the corn wa...

Bacterial isolates from maize plants showing a leaf spot disease were identified through molecular and phenotypic traits, showing that the isolates belong to Pantoea ananatis. Maize plants inoculated with those isolates showed a pathogenic reaction. This is the first report of a disease of Mexican maize caused by P. ananatis. Additional keywordsEn...

Many bacteria and fungi can enhance plant growth. The present review is limited to plant growth promoting rhizobacteria (PGPR). However, it includes endophytic bacteria that show plant growth enhancing activity as well. Also the best studied bacterial mechanisms of plant growth promotion are discussed, with a special emphasis on biological nitrogen...

In this study the antagonistic activity among 55 Gluconacetobacter diazotrophicus strains, belonging to 13 electrophoretic types (ETs), in culture media was analyzed. Antagonistic effects were seen only in strains belonging to two ETs named ET-1 and ET-3. Two out of 29 ET-1 strains, and 3 out of 7 ET-3 strains of G. diazotrophicus showed antagonist...

Diazotrophic bacteria were isolated, in two different years, from the rhizosphere and rhizoplane of coffee (Coffea arabica L.) plants cultivated in Mexico; they were designated as type DOR and type SAd isolates. They showed characteristics of the family Acetobacteraceae, having some features in common with Gluconacetobacter (formerly Acetobacter) d...

From the comparasion of 16S rRNA genes it was established that Brucella abortus constitutes a close relative of Rhizobium. The comparasion of more than a hundred isolates of different Brucella species and Rhizobium type strains showed that Brucella are closely related to R. tropici using 10 metabolic enzymes. The ribosomal sequences of R. tropici a...

The presence of endophytic Acetobacter diazotrophicus was tested for pineapple plants (Ananas comosus [L.] Merr.) grown in the field. Diazotrophic bacteria were isolated from the inner tissues of surface sterilized roots, stems, and leaves of pineapple plants. Phenotypic tests permitted the selection of presumptive nitrogen-fixing A. diazotrophicus...

Nitrogen fixation has been reported in almost 100 bacterial genera, but new diazotrophic bacteria over the last few years have been described. Because a majority of bacterial species are presently non-culturable and the search for diazotrophs in some environments has been relatively limited, it is recognized that there exist many more N2-fixing bac...

Early reports indicated that A. diazotrophicus occurs endophytically only in sugar cane and in a few other vegetatively propagated sucrose-rich plants (Döbereiner 1992). It was reported that this bacterium did not occur in sugar cane field soils nor in other soils (Döbereiner 1992; Li, MacRae, 1991). Contrasting with previous studies, we have demon...

Sugarcane, a vegetatively propagated plant, is been shown to be colonized endophytically by A. diazotrophicus. Attempts to isolate A. diazotrophicus have suggested that N-fertilization in sugarcane inhibits the population numbers of this bacterium colonizing the plant (Fuentes-Ramirez et al, 1993). Using microscopy techniques, this bacterium has be...

Acetobacter diazotrophicus was isolated from coffee plant tissues and from rhizosphere soils. Isolation frequencies ranged from 15 to 40% and were dependent on soil pH. Attempts to isolate this bacterial species from coffee fruit, from inside vesicular-arbuscular mycorrhizal fungi spores, or from mealybugs (Planococcus citri) associated with coffee...

Low-input, non-irrigated agriculture with low yields is predominant in Mexico, with maize and bean as the basic crops. Land for agriculture is very often taken away from forest areas and deforestation rates in Latin-America (due also to timbering, fires and urban use of forest land) are among the highest in the world. 5.3 million forest hectares we...

A total of 55 isolates of Acetobacter diazotrophicus recovered from diverse sucrose-rich host plants and from mealybugs associated with sugarcane plants were characterized by the electrophoretic mobilities of 12 metabolic enzymes. We identified seven different electrophoretic types (ETs), six of which are closely related within a genetic distance o...

Thirteen cane cultivars grown on fields in Mxico were sampled to assess the occurrence of Acetobacter diazotrophicus, a recently identified N2-fixing bacterium. Results showed that the isolation frequencies extended over a broad range (1.1 to 67%), likely to be related to the nitrogen fertilization level. The lowest isolation frequencies (1.1 to 2....