نقش باکتریوسین در رقابت‌پذیری باکتری‌های بیماریزای قارچ خوراکی

Among a various form of interactions, the host-pathogen interaction of plants has been well studied, while the edible mushroom-pathogen interactions are almost lacking in the literature. According to FAO reports, mushroom production surpassed 44.2 million tons worldwide in 2021. Edible mushrooms are among the most consumed fresh foods. Bacterial competition for nutrients, space, and oxygen resources is constant, and potentially toxic compounds produced by bacteria against hosts or competing species are crucial tools in this competition. To investigate the antagonism among pathogenic bacteria and assay their host range, pathogenic strains affecting edible mushrooms were studied: Pseudomonas tolaasii, [Pseudomonas reactans], Cedecea neteri, Pseudomonas sp., Pseudomonas agarici, Chryseobacterium sp., Mycetocola sp., Ewingella americana. The host range assay of all strains was conducted through comparative in vitro assays to identify pathogenicity on cabbage, carrot, cucumber, eggplant, potato, and pumpkin plants by using tissue. The results of the host range assay demonstrated that Pseudomonas tolaasii was particularly infected and caused discoloration in the tested tissues. In another set of experiments, antibiosis assays of strains were conducted to examine inhibitory metabolites and their effects on competing species. The results revealed the efficient role of bacterial blotch i.e., P. tolaasii is capable of producing bacteriocins or other antibacterial compounds. The mycopathogenic bacteria, i.e., Mycetocola sp., Chryseobacterium sp., and P. agarici, were encountered by P. tolaasii. Their population and colony growth were limited by zones of inhibition around P. tolaasii in the in vitro assay. Reports from the last few decades indicate that outbreaks of this pathogen in mushroom cultivation are more common than those caused by other mentioned pathogens. According to the results, the prevalence, aggressiveness, and predominance of P. tolaasii in mushroom cultivation might be driven by its antibiosis activity and ability to outcompete other mycopathogens on mushroom caps.