Rainfall water quality at Atlixco, Puebla

Margarita Teutli Andrés Armando Sánchez Erendira Moreno Gutierrez (2021, [Artículo, Artículo])

This work reports the follow up of rainfall water quality at Atlixco, Puebla during the 2018 season. The main objective of this work was to evaluate how height and pollutants define the quality of water precipitated. Samples were collected at the roof of a house in Atlixco center, and others at the roof of a convent located at the San Miguel Hill, this represents a 44 m difference in height. Chemical composition was analyzed for 19 physicochemical parameters using gravimetric and spectrophotometric techniques. Obtained results were compared with drinking water standards finding that Pb and Cd contents are exceeded. Also, it was found a strong contribution of terrestrial sources since the marine rates are above unit, as well as excess concentrations whose values go from negative to positive. Finally, Pearson correlation was obtained finding that most of chemical parameters correlations are in disagreement for both sites, fact which confirms that ionic content is strongly influenced by anthropogenic sources.

rainfall ionic content marine rates excess concentrations Lluvia contenido iónico cociente marino concentración en exceso Estudios urbanos CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA

Influence of conservation agriculture-based production systems on bacterial diversity and soil quality in rice-wheat-greengram cropping system in eastern Indo-Gangetic Plains of India

Anup Das virender kumar Peter Craufurd Andrew Mcdonald Sonam Sherpa (2023, [Artículo])

Introduction: Conservation agriculture (CA) is gaining attention in the South Asia as an environmentally benign and sustainable food production system. The knowledge of the soil bacterial community composition along with other soil properties is essential for evaluating the CA-based management practices for achieving the soil environment sustainability and climate resilience in the rice-wheat-greengram system. The long-term effects of CA-based tillage-cum-crop establishment (TCE) methods on earthworm population, soil parameters as well as microbial diversity have not been well studied. Methods: Seven treatments (or scenarios) were laid down with the various tillage (wet, dry, or zero-tillage), establishment method (direct-or drill-seeding or transplantation) and residue management practices (mixed with the soil or kept on the soil surface). The soil samples were collected after 7 years of experimentation and analyzed for the soil quality and bacterial diversity to examine the effect of tillage-cum-crop establishment methods. Results and Discussion: Earthworm population (3.6 times), soil organic carbon (11.94%), macro (NPK) (14.50–23.57%) and micronutrients (Mn, and Cu) (13.25 and 29.57%) contents were appreciably higher under CA-based TCE methods than tillage-intensive farming practices. Significantly higher number of OTUs (1,192 ± 50) and Chao1 (1415.65 ± 14.34) values were observed in partial CA-based production system (p ≤ 0.05). Forty-two (42) bacterial phyla were identified across the scenarios, and Proteobacteria, Actinobacteria, and Firmicutes were the most dominant in all the scenarios. The CA-based scenarios harbor a high abundance of Proteobacteria (2–13%), whereas the conventional tillage-based scenarios were dominated by the bacterial phyla Acidobacteria and Chloroflexi and found statistically differed among the scenarios (p ≤ 0.05). Composition of the major phyla, i.e., Proteobacteria, Actinobacteria, and Firmicutes were associated differently with either CA or farmers-based tillage management practices. Overall, the present study indicates the importance of CA-based tillage-cum-crop establishment methods in shaping the bacterial diversity, earthworms population, soil organic carbon, and plant nutrient availability, which are crucial for sustainable agricultural production and resilience in agro-ecosystem.

Metagenomics Bacterial Diversity Rice-Wheat-Greengram CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CONSERVATION AGRICULTURE DNA SEQUENCES EARTHWORMS METAGENOMICS SOIL QUALITY AGROECOSYSTEMS

Bacterial communities in the rhizosphere at different growth stages of maize cultivated in soil under conventional and conservation agricultural practices

Yendi Navarro-Noya Bram Govaerts Nele Verhulst Luc Dendooven (2022, [Artículo])

Farmers in Mexico till soil intensively, remove crop residues for fodder and grow maize often in monoculture. Conservation agriculture (CA), including minimal tillage, crop residue retention and crop diversification, is proposed as a more sustainable alternative. In this study, we determined the effect of agricultural practices and the developing maize rhizosphere on soil bacterial communities. Bulk and maize (Zea mays L.) rhizosphere soil under conventional practices (CP) and CA were sampled during the vegetative, flowering and grain filling stage, and 16S rRNA metabarcoding was used to assess bacterial diversity and community structure. The functional diversity was inferred from the bacterial taxa using PICRUSt. Conservation agriculture positively affected taxonomic and functional diversity compared to CP. The agricultural practice was the most important factor in defining the structure of bacterial communities, even more so than rhizosphere and plant growth stage. The rhizosphere enriched fast growing copiotrophic bacteria, such as Rhizobiales, Sphingomonadales, Xanthomonadales, and Burkholderiales, while in the bulk soil of CP other copiotrophs were enriched, e.g., Halomonas and Bacillus. The bacterial community in the maize bulk soil resembled each other more than in the rhizosphere of CA and CP. The bacterial community structure, and taxonomic and functional diversity in the maize rhizosphere changed with maize development and the differences between the bulk soil and the rhizosphere were more accentuated when the plant aged. Although agricultural practices did not alter the effect of the rhizosphere on the soil bacterial communities in the flowering and grain filling stage, they did in the vegetative stage.

Community Assembly Functional Diversity Intensive Agricultural Practices Plant Microbiome CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA SUSTAINABLE AGRICULTURE TILLAGE SOIL BACTERIA MAIZE

Enhancing maize's nitrogen-fixing potential through ZmSBT3, a gene suppressing mucilage secretion

jiafa chen XUECAI ZHANG Jianyu Wu (2023, [Artículo])

Aerial Roots ZmSBT3 Diazotroph CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA MAIZE ADVENTITIOUS ROOTS MUCILAGES NITROGEN FIXATION GENOME-WIDE ASSOCIATION STUDIES GENE CLONING NITROGEN FIXING BACTERIA

Nitrogen fertilizer application alters the root endophyte bacterial microbiome in maize plants, but not in the stem or rhizosphere soil

Alejandra Miranda Carrazco Yendi Navarro-Noya Bram Govaerts Nele Verhulst Luc Dendooven (2022, [Artículo])

Plant-associated microorganisms that affect plant development, their composition, and their functionality are determined by the host, soil conditions, and agricultural practices. How agricultural practices affect the rhizosphere microbiome has been well studied, but less is known about how they might affect plant endophytes. In this study, the metagenomic DNA from the rhizosphere and endophyte communities of root and stem of maize plants was extracted and sequenced with the “diversity arrays technology sequencing,” while the bacterial community and functionality (organized by subsystems from general to specific functions) were investigated in crops cultivated with or without tillage and with or without N fertilizer application. Tillage had a small significant effect on the bacterial community in the rhizosphere, but N fertilizer had a highly significant effect on the roots, but not on the rhizosphere or stem. The relative abundance of many bacterial species was significantly different in the roots and stem of fertilized maize plants, but not in the unfertilized ones. The abundance of N cycle genes was affected by N fertilization application, most accentuated in the roots. How these changes in bacterial composition and N genes composition might affect plant development or crop yields has still to be unraveled.

Bacterial Community Structure DArT-Seq Bacterial Community Functionality Genes Involved in N Cycling CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA AGRICULTURAL PRACTICES MAIZE RHIZOSPHERE STEMS NITROGEN FERTILIZERS

Fitorremediación asistida a través de bacterias, para suelos contaminados con metales pesados y plaguicidas

TANIA GÓMEZ MORALES (2023, [Otro, Trabajo terminal, especialidad])

El suelo es un recurso no renovable que nos proporciona diferentes beneficios, incluidos los servicios ecosistémicos. Sin embargo, actividades antropogénicas como la minería y la agricultura lo han contaminado. Las prácticas mineras y agrícolas liberan contaminantes como plaguicidas y metales pesados al suelo como contaminantes individuales o mezclas, generando importantes efectos adversos para el ambiente y la salud humana. Debido a esta problemática, se han desarrollado diferentes estrategias de remediación para sitios con presencia de estos co-contaminantes. Una de ellas es la fitorremediación asistida por bacterias, una técnica basada en la asociación de plantas y bacterias, donde ambos organismos se benefician y mejoran la eficiencia de la remediación.

Soil is a non-renewable resource that provides us with different benefits, including ecosystem services. However, anthropogenic activities such as mining and agriculture have contaminated it. Minery and agriculture practices release contaminants such as pesticides and heavy metals into the soil as individual pollutants or mixtures, generating important adverse environmental and human health effects. Due to this problem, different remediation strategies have been developed for sites with the presence of these co-contaminants; one of them is bacterial-assisted phytoremediation, a technique based on the association of plants and bacteria, where both organisms benefit and improve remediation efficiency.

BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA suelo, fitorremediación, bacterias, plaguicidas, metales pesados, co-contaminados. soil, phytoremediation, bacteria, pesticides, heavy metals, co-contaminated

Isolation and characterization of endophytic bacteria associated with roots of jojoba (Simmondsia chinensis (Link) Schneid)

RICARDO VAZQUEZ JUAREZ TANIA ZENTENO SAVIN ENRIQUE MORALES BOJORQUEZ Elvia Pérez Rosales Lilia Alcaráz Meléndez María Esther Puente Eduardo Quiroz Guzmán (2017, [Artículo])

"In this communication, the diversity and beneficial characteristics of endophytic bacteria have been studied in Simmondsia chinensis that has industrial importance because of the quality of its seed oil. Endophytes were isolated (N = 101) from roots of the jojoba plants collected, of which eight were identified by partial sequencing of the 16S rDNA gene. The isolated bacteria were Bacillus sp., Methylobacterium aminovorans, Oceanobacillus kimchi, Rhodococcus pyridinivorans and Streptomyces sp. All isolates had at least one positive feature, characterizing them as potential plant growth promoting bacteria. In this study, R. pyridinivorans and O. kimchi are reported as plant growth promoters."

Endophytic bacteria, plant growth promoters, Simmondsia chinensis, seed oil BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA MICROBIOLOGÍA BACTERIOLOGÍA BACTERIOLOGÍA

In vitro Digestibility of Yarrowia lipolytica Yeast and Growth Performance in Whiteleg Shrimp Litopenaeus vannamei

ANA RUTH ALVAREZ SANCHEZ CLAUDIO HUMBERTO MEJIA RUIZ Héctor Gerardo Nolasco Soria Alberto Peña Rodríguez (2018, [Artículo])

"Marine yeasts used in aquaculture disease control can also be an important protein source for improving feeding and nutrition of crustaceans. Yarrowia lipolyticca has been studied for its capacity to secrete heterologous proteins and high content of unsaturated fatty acids, beta-glucan, and mannane polymers in the cell wall. We measured in vitro digestibility of Y. lipolyticca by whiteleg shrimp Litopenaeus vannamei digestive enzymes, and an in vivo assay of Y. lipolytica in feed onwhiteleg shrimp growth. We found that digestive gland enzymes of shrimp digest Y. lipolytica, based on reduced optical density of a yeast suspension. Digestion was –0.00236 ± 0.00010 OD U min–1 for intact cells and –0.00325 ± 0.00010 OD U min–1 for lysed cells. Release of reducing sugars in intact cells (5.3940 ± 0.1713 μmol h–1), and lysed cells (0.8396 ± 0.2251 μmol h–1) was measured. Digestive gland treatment significantly reduced cell viability (near 100%), relative to the control. Electron microscopy shows that the cell wall of Y. lipolytica exposed to the digestive gland enzymes was severely damaged. Shrimp diet containing Y. lipolytica resulted in significantly higher weight gain and specific growth rate of whiteleg shrimp."

Marine yeast, cell digestibility, cell viability, turbidimetry, reduced sugars BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOQUÍMICA BIOQUÍMICA DE ALIMENTOS BIOQUÍMICA DE ALIMENTOS

Whole-genome comparison between reference sequences and oyster Vibrio vulnificus C-genotype strains

CARLOS ABRAHAM GUERRERO RUIZ (2019, [Artículo])

Whole-genome sequences of Vibrio vulnificus clinical genotype (C-genotype) from the CICESE Culture Collection, isolated from oysters, were compared with reference sequences of CMCP6 and YJ016 V. vulnificus C-genotype strains of clinical origin. The RAST web server estimated the whole genome to be ~4.8 Mb in CICESE strain 316 and ~4.7 Mb in CICESE strain 325. No plasmids were detected in the CICESE strains. Based on a phylogenetic tree that was constructed with the whole-genome results, we observed high similarity between the reference sequences and oyster C-genotype isolates and a sharp contrast with environmental genotype (E-genotype) reference sequences, indicating that the differences between the C- and E-genotypes do not necessarily correspond to their isolation origin. The CICESE strains share 3488 genes (63.2%) with the YJ016 strain and 3500 genes (63.9%) with the CMCP6 strain. A total of 237 pathogenicity associated genes were selected from reference clinical strains, where—92 genes were from CMCP6, 126 genes from YJ016, and 19 from MO6-24/ O; the presence or absence of these genes was recorded for the CICESE strains. Of the 92 genes that were selected for CMCP6, 67 were present in both CICESE strains, as were as 86 of the 126 YJ016 genes and 13 of the 19 MO6-24/O genes. The detection of elements that are related to virulence in CICESE strains—such as the RTX gene cluster, vvhA and vvpE, the type IV pili cluster, the XII genomic island, and the viuB genes, suggests that environmental isolates with the C-genotype, have significant potential for infection. © 2019 Guerrero et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Article, bacterial gene, bacterial strain, bacterial virulence, comparative study, controlled study, gene cluster, gene identification, genomic island, genotype, nonhuman, phylogenetic tree, sequence analysis, strain identification, Vibrio vulnificus BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA GENÉTICA GENÉTICA

Do marine reserves increase prey for California sea lions and Pacific harbor seals?

ALEJANDRO ARIAS DEL RAZO (2019, [Artículo])

Community marine reserves are geographical areas closed to fishing activities, implemented and enforced by the same fishermen that fish around them. Their main objective is to recover commercial stocks of fish and invertebrates. While marine reserves have proven successful in many parts of the world, their success near important marine predator colonies, such as the California sea lion (Zalophus californianus) and the Pacific harbor seal (Phoca vitulina richardii), is yet to be analyzed. In response to the concerns expressed by local fishermen about the impact of the presence of pinnipeds on their communities’ marine reserves, we conducted underwater surveys around four islands in the Pacific west of the Baja California Peninsula: two without reserves (Todos Santos and San Roque); one with a recently established reserve (San Jeronimo); and, a fourth with reserves established eight years ago (Natividad). All these islands are subject to similar rates of exploitation by fishing cooperatives with exclusive rights. We estimated fish biomass and biodiversity in the seas around the islands, applying filters for potential California sea lion and harbor seal prey using known species from the literature. Generalized linear mixed models revealed that the age of the reserve has a significant positive effect on fish biomass, while the site (inside or outside of the reserve) did not, with a similar result found for the biomass of the prey of the California sea lion. Fish biodiversity was also higher around Natividad Island, while invertebrate biodiversity was higher around San Roque. These findings indicate that marine reserves increase overall fish diversity and biomass, despite the presence of top predators, even increasing the numbers of their potential prey. Community marine reserves may help to improve the resilience of marine mammals to climate-driven phenomena and maintain a healthy marine ecosystem for the benefit of both pinnipeds and fishermen. © 2019 Arias-Del-Razo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Article, biodiversity, biomass, climate change, ecosystem resilience, environmental exploitation, fish stock, fishing, marine environment, marine invertebrate, nonhuman, Phoca vitulina, Pinnipedia, prey searching, Zalophus californianus, animal, biom BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA ANIMAL (ZOOLOGÍA) BIOLOGÍA ANIMAL (ZOOLOGÍA)