Sustainable Protocols for Cellulose Nanocrystals Synthesis from Tomato Waste and Their Antimicrobial Properties against Pseudomonas syringae pv. tomato

Abstract

Nanotechnology is rapidly gaining ground in crop protection, with the growing quest for sustainable nanopesticides and nanocarriers for plant pathogen management. Among them, cellulose nanocrystals (CNC) are emerging as innovative agrofood-waste-derived antimicrobial materials. In this work, new chemical and enzymatic CNC extraction methods from tomato harvest residues were evaluated. The obtained nanomaterials were characterized and tested for their antimicrobial properties on Pseudomonas syringae pv. tomato (Pto), the causal agent of bacterial speck disease on tomato. Both protocols were efficient. The enzymatic extraction method was greener, producing purer CNC at slightly lower yield. The obtained CNC, although they weakly inhibited cell growth and did not promote reactive oxygen species (ROS) formation, provoked bacterial aggregation and the inhibition of biofilm production and swimming motility. Both protocols produced CNC with similar morpho-chemical features, as well as promising antimicrobial activity against plant bacterial pathogens, suggesting their potential role in sustainable crop protection strategies. The new protocols could be a valuable alternative to conventional methods.

Investigating Cellulose Nanocrystals’ Biocompatibility and Their Effects on Pseudomonas syringae pv. tomato Epiphytic Survival for Sustainable Crop Protection

“…Copper hydroxide at the field dose showed the highest reduction on the epiphytic populations, beginning from the first day after the treatment. This could be easily explained by considering the well-known ability of cupric ions to inhibit and kill bacterial cells, as previously shown in vitro [29]. Moreover, we evaluated the possibility of halving the field dose of copper hydroxide by applying it in combination with CNCs.…”

“…CNC, chemically synthetized from tomato waste in a previous work, were used [29]. All the chemical reagents used in this work were purchased from Sigma-Aldrich, Inc.…”

“…Many research studies have also been conducted on agrofood waste as a source for cellulose extraction and subsequent CNC synthesis [25][26][27][28]. In our previous work, we successfully demonstrated the possibility of isolating CNC (starting from tomato harvesting residues) via a chemical-and enzymaticmediated protocol, in order to make the whole process more sustainable [29]. At the same time, we were able to investigate CNCs' antimicrobial mechanisms on the model plant pathogen Pseudomonas syringae pv.…”

“…The aim of this work was indeed to study the effects of a CNC as a potential antibacterial compound against Pst in comparison with traditional copper-based treatments. We first described some of the most relevant in vitro modes of action of CNC on Pst cells, pointing out an inhibition on the swimming motility and a reduction of produced biofilm when bacteria where exposed to CNC at 1% w/v [29]. Starting from this evidence, we moved forward to investigate the potential application of CNC on tomato plants, looking at their biocompatibility and then at their effects on Pst epiphytic survival.…”

Evaluation of Ethno-Veterinary Grasses from Suburbs through Microscopic Technique: Insights into Antioxidant Defense System and Phenol

“…The data was compiled in terms of three replicates as means ± of standard error. One way analysis (ANOVA) was employed to check the differences among the means via the method used [56].…”