Overuse of the chemical compounds and toxic elements leads to problems and transmission of contaminants and pollutants to humans and other living organisms. One of the industries’ byproducts of the agriculture sector is production of various composts from the organic raw materials that the best type of which is so – called Vermicompost. In this study, effects of raw materials on qualitative and quantitative characteristics of Vermicompost are discussed. To do so, sheep manure, pomegranate peels, spent mushroom compost either singly or double, triple or fourfold chopped corn, sugar beet pulp and sawdust were used. This research project was conducted in a completely randomized design experiment with 23 treatments with 3 replications. Results revealed that various bed combinations exert different effects on Vermicompost quality such that, the Vermicomposting process led to a significant decrease in electrical conductivity (EC) and a significant increase in pH in most of the culture (seed) beds. Also, the levels of Nitrogen, Phosphorous and Potassium in most treatments increased following completion of the vermicomposting process. As a result, this process can be introduced as an organic fertilizer with complete nutrients for improving chemical characteristics of agricultural wastes to usable fertilizers.

Listeria monocytogenes, Vibrio parahaemolyticus and Morganella morganii are closely related to foodborne illnesses caused by the consumption of seafood and ready-to-eat (RTE) food. Traditional Chinese medicines (TCM) have been widely studied as complementary and alternative medicines, and many of them have been verified to have antimicrobial properties. The purpose of this research was to study antimicrobial effects of plant extracts as potential preservatives in seafood products and to identify the primary antimicrobial compounds in plant extracts. Four plants, Pomegranate peel (PP, Punica Granatum L.), Chinese gallnut (CG, Galla chinensis), forsythia fruit (FS, Forsythia suspensa) and Baikal skullcap root (BS, Scutellaria baicalensis) were ground and extracted with 70% methanol, respectively. The extracts were diluted at tested for antimicrobial activities on V. parahaemolyticus, L. monocytogenes and M. morganii both in agar diffusion assay using tryptic soy agar (TSA), and in microdilution assay using tryptic soy broth (TSB). Both CG and PP extracts, with concentrations no lower than 1 mg/ml, significantly inhibited both V. parahaemolyticus and L. monocytogenes (P<0.01) and reduced the bacterial population by up to 4 logs. No significant inhibition was observed with FS and BS extracts, except for BS at 5 mg/ml on V. parahaemolyticus. None of the extracts showed significant inhibition against M. morganii. The antibacterial activities of CG and PP 70% methanol extracts were tested in ground raw tuna and cooked tail-on shrimp. The extracts were mixed in tuna with final concentration at 1.7 mg/ml, and applied as soaking treatments (5 mg/ml) for shrimp. Both CG and PP extracts inhibited V. parahaemolyticus on both food matrices while only CG significantly inhibited L. monocytogenes. The 70% methanol crude extract of CG was analyzed by HPLC and LC-MS. Oligo-galloyl-O-glucose (nGG, n=1-10) are the major compounds in CG. The crude CG extract was fractionated using HPLC and the fractions were collected based on elution time and tested for their antimicrobial activities against V. parahaemolyticus and L. monocytogenes using agar diffusion methods. The fractions containing 3GG-8GG were the most active antimicrobials on both bacteria. / Ph. D.