EndophyticBacillusstrains isolated from alfalfa (Medicago sativaL.) seeds: enhancing the lifespan ofCaenorhabditis elegans

Abstract

Medicago sativa L. (alfalfa) is an important forage crop throughout the world. Despite the abiotic nutritional components of alfalfa having been extensively studied, there is only limited information on alfalfa endophytes. In this study, thirteen endophytic bacteria were isolated from alfalfa seeds. Bacillus (76·9%) was the most abundant genus, followed by Enterobacter (15·4%), Brevibacterium (7·7%), Geobacillus (7·7%) and Staphylococcus (7·7%). Four of the 13 endophytic bacteria, including Bacillus amyloliquefaciens EnB‐alf1, Bacillus subtilis EnB‐alf3, EnB‐alf5 and EnB‐alf13, were capable of significantly extending the lifespan of Caenorhabditis elegans. In addition, B. amyloliquefaciens EnB‐alf1 enhanced the resistance of C. elegans to thermal stress whereas B. subtilis EnB‐alf3 enhanced the resistance to oxidative stress. Further studies demonstrated that the enhanced lifespan of the worm was depended on the function of DAF‐2/DAF‐16 and was associated with the colonization of strain in the worms’ intestines when strain EnB‐alf1 or strain EnB‐alf3 was presented to the worms as food sources. Our results suggest that some endophytic Bacillus strains isolated from alfalfa are beneficial on C. elegans health. Significance and Impact of the Study Medicago sativa L. (alfalfa) is an important forage crop throughout the world. Despite the abiotic nutritional components of alfalfa having been extensively studied, there is only limited information available on alfalfa endophytes. Beneficial bacteria residing in the host intestine have been shown to affect host longevity. However, there is limited information available on the functions of alfalfa seed endophytes to nematodes. In this study, four endophytic Bacillus strains isolated from alfalfa seeds were found to significantly extend the lifespan of Caenorhabditis elegans and enhance resistance to thermal and oxidative stress. Our results suggest that some endophytic Bacillus strains isolated from alfalfa seeds can promote good health in C. elegans.

Detoxification of Aflatoxin B1 by a Potential Probiotic Bacillus amyloliquefaciens WF2020

“…Additionally, B. amyloliquefaciens WF2020 is not an antibiotic-resistant bacterium due to susceptibility to various antibiotics, including tetracycline, penicillin, cefalexin, ampicillin, streptomycin, kanamycin, gentamicin, ciprofloxacin, chloramphenicol, vancomycin, imipenem, rifampin, erythromycin, and norfloxacin. Moreover, B. amyloliquefaciens WF2020 significantly enhanced the lifespan of C. elegans by an average of 20.78%, which was slightly lower than that of B. amyloliquefaciens EnB-alf1 isolated from alfalfa ( Medicago sativa L.) seeds ( Zhang et al, 2019 ). On the other hand, B. amyloliquefaciens WF2020 converted AFB1 into metabolites with a loss of mutagenicity and non-toxicity to the lifespan of C. elegans .…”

Apple rootstocks with different phosphorus efficiency exhibit alterations in rhizosphere bacterial structure

“…For apple rootstocks, Rhizobium and Bacillus represented more than 1% of the abundance, and there was a significant positive correlation between the Bacillus and the root phosphorus concentration (Table ). Pseudomonas and Bacillus , which are known as phosphate‐solving bacteria, can reportedly resist various environmental stresses, through actions such inhibiting pathogens and inducing systemic resistance (Wu et al ; Zhang et al ), and they significantly promote nutrient uptake in host plants through fixing nitrogen, dissolving phosphorus and producing hormone substances to promote growth (Verhagen et al ; Karimi et al ). In this study, the Bacillus abundance was significantly higher in the PE rhizosphere, and it had highly positive Pearson correlations with the phosphorus concentration.…”

Endophytic Bacillus velezensis strain B‐36 is a potential biocontrol agent against lotus rot caused by Fusarium oxysporum

“…For instance, Bacillus sp. are considered bacteria with the widest potential application in plant pest control (Wu et al ), and some of them are endophytic bacteria with plant growth‐promoting activity (El‐Deeb et al ; Radhakrishnan et al ; Zhang et al ). The production of antifungal and antibacterial compounds has been reported as the main mechanism by which Bacillus sp.…”