Plant-microbe and abiotic factors influencing Salmonella survival and growth on alfalfa sprouts and Swiss chard microgreens.

In this study, two Salmonella enterica serovars (Hartford and Cubana) applied, at multiple inoculation levels, were evaluated for survival and growth on alfalfa sprouts and Swiss chard microgreens using the most probable number (MPN) method. Various abiotic factors were also examined for their effects on Salmonella survival and growth on sprouts and microgreens. Community level physiological profiles (CLPP) of sprout/microgreen rhizospheres with different levels of S. enterica inoculation at different growth stage were characterized with Biolog EcoPlates. In the seed contamination group, the ability of S. enterica to grow on sprouting alfalfa seeds was affected by both seed storage time and inoculation level, but not serovar. However, the growth of S. enterica on Swiss chard microgreens was affected by serovar, and inoculation level. Seed storage time had little effect on the average level of Salmonella population in microgreens. In the irrigation water contamination group, the growth of Salmonella in both alfalfa sprouts and microgreens was largely affected by inoculation level. Surprisingly, growing medium was found to play an important role in Salmonella survival and growth in microgreens. CLPP analysis showed significant changes in the microbial community metabolic diversity during sprouting for alfalfa sprouts, but few temporal changes were seen in microgreens. The data suggest that the change in rhizosphere bacterial functional diversity was host-dependent but independe...
Source: Applied and Environmental Microbiology - Category: Microbiology Authors: Tags: Appl Environ Microbiol Source Type: research