Cultivable endophytic bacteria from heavy metal(loid)-tolerant plants

Abstract

To evaluate the interactions among endophytes, plants and heavy metal/arsenic contamination, root endophytic bacteria of Prosopis laevigata (Humb and Bonpl. ex Willd) and Sphaeralcea angustifolia grown in a heavy metal(loid)-contaminated zone in San Luis Potosi, Mexico, were isolated and characterized. Greater abundance and species richness were found in Prosopis than in Sphaeralcea and in the nutrient Pb-Zn-rich hill than in the poor nutrient and As-Cu-rich mine tailing. The 25 species identified among the 60 isolates formed three groups in the correspondence analysis, relating to Prosopis/hill (11 species), Prosopis/mine tailing (4 species) and Sphaeralcea/hill (4 species), with six species ungrouped. Most of the isolates showed high or extremely high resistance to arsenic, such as ≥100 mM for As(V) and ≥20 mM for As(III), in mineral medium. These results demonstrated that the abundance and community composition of root endophytic bacteria were strongly affected by the concentration and type of the heavy metals and metalloids (arsenic), as well as the plant species.

Effects of growth‐promoting rhizobacteria on maize growth and rhizosphere microbial community under conservation tillage in Northeast China

“…Considering that the present experimental field contained black soil and was located within a 'golden corn belt' that accounts for approximately 40% of the national maize production in China (NBSC, 2019), the present results are important for promotion of PGPR inoculation under conservation tillage in a cold region, although application of the inoculants selected in the present study may be limited to areas with a similar soil type and climate. In addition, many previous studies have revealed that the microbial communities associated with plants (Zhang et al ., 2011; Román‐Ponce et al ., 2016) are determined by both the plant species and soil (biotic and abiotic) features. Therefore, a preferable strategy for PGPR selection and application might be to focus on efficient screening of region‐ and plant‐specific PGPR, which may have a stable effect on improvement of crop production.…”

Characterization of Arsenic-Resistant Endophytic Bacteria From Alfalfa and Chickpea Plants

“…Previous reports indicated that bacteria resistant to arsenic mostly belong to phyla Proteobacteria, firmicutes, and Actinobacteria (Sheik et al, 2012). Several genera like Bacillus, Paenibacillus, Staphylococcus, Kocuria, Sphigomonas, Arthrobacter, Brevibacterium, Pseudomonas, Microbacterium, Enterobacter, Stenotrophomonas, and Rhizobium have been reported as arsenic-resistant endophytic bacteria (Zhu et al, 2014;Román-Ponce et al, 2016Tiwari et al, 2016).…”

Aislamiento e identificación de bacterias tolerantes y bioacumuladoras de metales pesados, obtenidas de los jales mineros El Fraile, México

“…En cajas de agar LB se adicionaron sales metálicas; Pb (NO 3 ) 2 , Zn (NO 3 ) 2 , Cd (NO 3 ) 2 , Cu (NO 3 ) 2 , NaAsO 2 , y NaH 2 AsO 4 , AgNO 3 , en concentraciones de ascendentes que van de 0.5 a 20 mM. La CMI se interpretó como la concentración más alta de sales en la cual no se observó crecimiento después de 7 días de exposición (Yu et al, 2014;Román-Ponce et al, 2016).…”

“…La minería ha generado sitios altamente contaminados con metales pesados y metaloides, ocasionando que dicha actividad sea un problema ambiental con deterioro del suelo, contaminación de aire y agua, e impacto negativo en la diversidad y riqueza de plantas, insectos y vertebrados. La diversidad y abundancia microbiana en el suelo, y en la rizosfera de las plantas que sobreviven en esos sitios, también se deteriora (Tchounwou et al, 2012;Román-Ponce et al, 2016). La persistencia de los metales en el ambiente, causa efectos adversos a los ecosistemas, y la restauración ambiental, aún es muy costosa (Mosa et al, 2016).…”