Pseudomonas fluorescens is considered among the main spoilage microorganisms due to its ability to produce proteases. Food deterioration caused by spoilage microorganisms has a major impact on food quality and the environment. The inactivation of Pseudomonas fluorescens growth and protease production was intensively investigated with the use of Salmide®, A Sodium Chlorite-Based Oxy­halogen Disinfectant. A unique M9 media was also developed to assure sufficient protease productions with different mutants of Pseudomonas fluorescens as a microbioreactor. Mutations were induced by classical whole-cell mutagenesis using N-methyl-N′- nitro-N-nitrosoguanidine (NTG). A dramatic decrease occurred in protease activity when different Salmide concentrations (5, 10, and 15 ppm) were added to the growth culture followed by a complete inhibition concentration (20, 25, 50, and 100 ppm) of Salmide. However, no significant inhibition occurred once it is secreted out of cells. Some mutants were resistant and remains highly stable with high protease production under stressful conditions of Sodium Chlorite-Based Oxy­halogen. The production of the protease showed a linear correlation with the increase in incubation time using a continuous culture bioreactor system and recorded maximum protease activity after 40 h. Our findings would offer alternative antimicrobial procedures for food and industrial sectors.

A FLATOXIN B1 (AFB1) is mutagenic, carcinogenic, and harmful to humans and animals.Different physical and chemical methods have been proposed to reduce mycotoxins but few have been approved for practical application. This study investigated the possible use of certain bacterial species were isolated from different agricultural soils as biological control agents against the growth of toxigenic Aspergillus flavus and Aspergillus parasiticus isolated from sorghum and peanuts as well as biodegradation of aflatoxin B1 (AFB1). Out of these 30 bacterial isolates, 6 isolates showed that have antagonistic effects against the aflatoxigenic fungi but with varying efficiencies. The six different isolates were screened for their ability to degrade AFB1. Out of 6 isolates, one isolate showed high reduction activity of AFB1. Maximum antifungal activities were observed in one isolate was identified as Staphylococcus lentus. S. lentus completely prevented the A. flavus and A. parasiticus growth and completely degraded AFB1 in Liquid Culture. LC-MS/MS analysis revealed that S. lentus resulted in a 96.54% degradation of AFB1, but no products has been detected. In practical application, it was found that S. lentus at concentration of 10 and 25mL kg -1 were completely prevented the growth of A. flavus and A. parasiticus in sorghum and peanuts, respectively, consequently no aflatoxin were produced. According to our information, this is the first study to prove that Staphylococcus lentus has the capability to inhibit the growth of Aspergillus flavus and Aspergillus parasiticus by 100% and degrading AFB1 by 96%.