Synergistic antimicrobial effects of waste cotton cloth extracted cellulose with phytofabricated TiO2 for potential application in agriculture

A substantial economic loss in agriculture due to plant microbial diseases has driven attention towards developing nanomaterials as antimicrobial agents for crop protection. The currently available fungicides and pesticides are highly toxic and non-degradable, causing environmental pollution and even being harmful to consumers of agricultural products. However, this work attempts to develop a non-toxic and biocompatible nanomaterial as a good antimicrobial agent. In this regard, a waste product, i.e., waste or used cotton cloth, has been recycled and used as a source of cellulose (natural biopolymer) extraction and for isolation of nanocrystalline cellulose (NCell) as well. Another biocompatible nanomaterial, titanium oxide (TiO₂), was synthesized using Azadirachta indica leaf extract to utilize the advantage of phytochemicals in the green extract. Furthermore, the two eco-friendly nanocomposites of NCell were prepared as nanomedicines, one with commercially available chemical TiO₂ (CNC) and another with green TiO₂ (GNC). The nanocomposites (CNC and GNC), in comparison with their individual nanomaterials (NCell and TiO₂), were examined against phytopathogens: Xanthomonas campestris pv. campestris (Xcc), Bacillus subtilis (BS) and Pseudomonas fluorescens (Psfl); fungi: Fusarium graminearum and Phytophthora spp. The results illustrated the synergistic effects of NCell and TiO₂ as nanocomposites showing a stronger and longer ability to inhibit pathogen growth and, thus, proved GNC to be an excellent antimicrobial agent for crop protection in agriculture.