Arthrobacter sp. Inoculation Improves Cactus Pear Growth, Quality of Fruits, and Nutraceutical Properties of Cladodes

Abstract

A study was undertaken to determine the effects of a strain of Arthrobacter sp., a Plant Growth-Promoting Bacteria (PGPB), on plant phenology and qualitative composition of Opuntia ficus-indica (L.) Mill. fruits and cladodes. The strain was inoculated in soil, and its effects on cactus pear plants were detected and compared to nontreated plants. Compared to the latter, the treatment with bacteria promoted an earlier plant sprouting (2 months before the control) and fruitification, ameliorating fruit quality (i.e., improved fresh and dry weight: + 24% and + 26%, respectively, increased total solid content by 30% and polyphenols concentrations by 22%). The quality and quantity of monosaccharides of cladodes were also increased by Arthrobacter sp. with a positive effect on their nutraceutical value. In summer, the mean values of xylose, arabinose, and mannose were significantly higher in treated compared to not treated plants (+ 3.54; + 7.04; + 4.76 mg/kg d.w. respectively). A similar trend was observed in autumn, when the cladodes of inoculated plants had higher contents, i.e., 33% xylose, 65% arabinose, and 40% mannose, respect to the controls. In conclusion, Arthrobacter sp. plays a role in the improvement of nutritional and nutraceutical properties of cactus pear plants due to its capabilities to promote plant growth. Therefore, these results open new perspectives in PGPB application in the agro-farming system as alternative strategy to improve cactus pear growth, yield, and cladodes quality, being the latter the main by-product to be utilized for additional industrial uses.

Biosynthetic gene clusters with biotechnological applications in novel Antarctic isolates from Actinomycetota

“…The latter obtained from an Actinomycetota, Nocardiopsis sp., has potent antibiotic properties (Engelhardt et al 2010). Therefore, it is important to further investigate BGCs belonging to this family as several beneficial properties have been demonstrated, such as the ability to act as plant growth promoters in various plant species, as seen in members belonging to the genera Arthrobacter and Pseudarthrobacter (Chhetri et al 2022;Jiang et al 2022;Ham et al 2022;Platamone et al 2023). In addition, species of the genera Arthrobacter and Micrococcus have been used for the bioremediation of organic compounds and heavy metals (Behera and Das 2023).…”

Developing stable, simplified, functional consortia from Brachypodium rhizosphere for microbial application in sustainable agriculture

“…Consequently, keystone taxa can be considered ecologically important microbes responsible for shaping the microbial community structure and dynamics ( Agler et al, 2016 ). Notably, 8 keystone taxa from the hubs belong to genera known to exhibit PGP traits ( Kielak et al, 2016 ; Alijani et al, 2020 ; Jaiswal et al, 2021 ; Sah et al, 2021 ; Juma et al, 2022 ; Platamone et al, 2023 ). The robust link between keystone taxa and PGP traits underscores the significant impact of PGP bacteria on the dynamics of the rhizosphere microbiome ( Pii et al, 2015 ), stressing the need for careful selection in constructing microbial consortia.…”