The implementation of bioreactor systems for the production of bacterial inoculants as biofertilizers has become very important in recent decades. However, it is essential to know the bacterial growth optimal conditions to optimize the production and efficiency of bioinoculants. The aim of this work was to identify the best nutriment and mixing conditions to improve the specific cell growth rates (µ) of two PGPB (plant growth-promoting bacteria) rhizobial strains at the bioreactor level. For this purpose, the strains Sinorhizobium mexicanum ITTG-R7^T and Sinorhizobium chiapanecum ITTG-S70^T were previously reactivated in a PY-Ca²⁺ (peptone casein, yeast extract, and calcium) culture medium. Afterward, a master cell bank (MCB) was made in order to maintain the viability and quality of the strains. The kinetic characterization of each bacterial strain was carried out in s shaken flask. Then, the effect of the carbon and nitrogen sources and mechanical agitation was evaluated through a factorial design and response surface methodology (RSM) for cell growth optimization, where µ was considered a response variable. The efficiency of biomass production was determined in a homemade bioreactor, taking into account the optimal conditions obtained during the experiment conducted at the shaken flask stage. In order to evaluate the biological quality of the product obtained in the bioreactor, the bacterial strains were inoculated in common bean (Phaseolus vulgaris var. Jamapa) plants under bioclimatic chamber conditions. The maximum cell growth rate in both PGPB strains was obtained using a Y-Ca²⁺ (yeast extract and calcium) medium and stirred at 200 and 300 rpm. Under these growth conditions, the Sinorhizobium strains exhibited a high nitrogen-fixing capacity, which had a significant (p < 0.05) impact on the growth of the test plants. The bioreactor system was found to be an efficient alternative for the large-scale production of PGPB rhizobial bacteria, which are intended for use as biofertilizers in agriculture.

Insects are often associated with diverse microorganisms that enhance their metabolism and nutrient assimilation. These microorganisms, residing in the insect’s gut, play a crucial role in breaking down complex molecules into simpler compounds essential for the host’s growth. This study investigates the diversity and functional potential of symbiotic bacteria in the gut of Arsenura armida (Lepidoptera: Saturniidae) larvae, an edible insect from southeastern Mexico, using culture-dependent and metagenomic approaches. Bacterial strains were isolated from different gut sections (foregut, midgut, and hindgut) and cultured on general-purpose media. Isolates were identified through 16S rRNA gene sequencing and genomic fingerprinting. Metagenomics revealed the bacterial community structure and diversity, along with their functional potential. A total of 96 bacterial strains were isolated, predominantly Gram-negative bacilli. Rapidly growing colonies exhibited enzymatic activity, cellulose degradation, and sugar production. Phylogenetic analysis identified eight genera, including Acinetobacter, Bacillus, Enterobacter, Pseudomonas, and others, with significant cellulose-degrading capabilities. Metagenomics confirmed Bacillota as the most abundant phylum. These complementary methods revealed abundant symbiotic bacteria with key metabolic roles in A. armida, offering promising biotechnological applications in enzymatic bioconversion and cellulose degradation.

Pleurotus ostreatus, commonly known as the oyster mushroom, is increasingly recognized as a key agrobiotechnological resource within sustainable development frameworks due to its ecological adaptability, rich nutritional profile, and broad socioeconomic contributions. This review integrates agroecological, socioeconomic, and biotechnological dimensions to examine its taxonomic identity, resilience to diverse environmental conditions, and efficiency in organic waste bioconversion. The species plays a critical role in circular bioeconomy strategies by advancing environmental sustainability, improving food and nutrition security, and supporting rural livelihoods through accessible, low-cost cultivation practices. Additionally, P. ostreatus demonstrates significant nutraceutical and pharmacological properties, making it a promising candidate for innovative biotechnological applications. Drawing on global and local case studies, this review highlights the species’ capacity to strengthen resilient agroecological systems and inclusive approaches to public health and livelihoods. Promoting its cultivation further enhances community well-being by generating equitable economic opportunities, empowering small-scale producers, and fostering social cohesion through sustainable food networks and shared resource systems. According to Mexico’s agroecological conditions, P. ostreatus represents a potential alternative to generate socioeconomic and nutritional benefits for the population at large.

Beneficial soil microorganisms, particularly plant probiotic bacteria (PPB), play a pivotal role in promoting plant growth, development, and overall health through root colonization. PPB-based biofertilizers offer a sustainable and eco-friendly alternative to conventional agricultural inputs. This study evaluates the plant probiotic potential of three native bacterial strains Rhizobium sp. ACO-34A, Sinorhizobium mexicanum ITTG R7^T, and Sinorhizobium chiapasense ITTG S70^T to enhance the growth, quality, and sugar content of Agave tequilana. A comprehensive genomic and functional analysis was conducted for each strain to assess their plant probiotic traits. Additionally, a greenhouse inoculation assay was performed on six-month-old agave seedlings at the “piña” stage to evaluate the effects of these strains on plant growth and sugar content. Comparative genomic analysis revealed that these rhizobial strains harbor genes associated with key plant probiotic traits, reinforcing their role in enhancing plant development. The results demonstrated significant effects (p < 0.05) on growth and sugar content in inoculated plants. ACO-34A increased plant height by 35.4%, fresh weight by 41.5%, and inulin content by 57.3%, while ITTG-R7^T showed improvements of 26.4%, 35.2%, and 38.2%, respectively, compared to the control, and ITTG S70^T also exhibited enhancements, although to a lesser extent, with increases of 23.5% in plant height, 28.9% in fresh weight, and 31.2% in inulin content. These findings highlight the biofertilizer potential of these native rhizobial strains, particularly Rhizobium sp. ACO-34A, positioning them as promising candidates for the sustainable cultivation of A. tequilana.

El maíz (Zea mays L.) es un cultivo de gran importancia agrícola y socioeconómica a nivel mundial. La búsqueda y aplicación de bacterias promotoras del crecimiento vegetal (PGPB) representa una estrategia sostenible para mejorar la productividad agrícola. El objetivo de este estudio fue identificar y caracterizar cepas bacterianas rizosféricas y endófitas con potencial PGPB asociadas al maíz en suelos de Chiapas, México, mediante el uso de técnicas moleculares y pruebas in vitro. Se evaluó la capacidad de cada cepa para la fijación de nitrógeno, solubilización de fosfatos y producción de sideróforos. La diversidad genética de las cepas se determinó mediante huellas genómicas ERIC-PCR, y su identidad fue confirmada por secuenciación del gen 16S rRNA. Se aislaron un total de 46 cepas, las cuales fueron agrupadas en 26 patrones genómicos. Los resultados obtenidos mostraron que los aislados pertenecen a los géneros Klebsiella, Acinetobacter y Pseudomonas, seguidos por Pseudacidovorax, Stenotrophomonas y Ochrobactrum. El género Klebsiella presentó una notable capacidad para la solubilización de fósforo, producción de sideróforos y fijación de nitrógeno. Las condiciones específicas del campo de estudio jugaron un papel crucial en la obtención de microorganismos de interés benéfico. Estos hallazgos resaltan el potencial de las bacterias rizosféricas y endófitas aisladas del maíz como una fuente prometedora para la identificación de microorganismos con posibles aplicaciones biotecnológicas y contribuir en mejorar la sostenibilidad y productividad de los cultivos.