Unconventional raw plant matrices as source of pro-technological microbes for application in food fermentation.

The use of unconventional raw materials within food processing is becoming a widely used sustainable and innovative approach for developing food products with enhanced nutritional, organoleptic, technological, functional, and preservative characteristics to satisfy the increasing request for a healthy diet. These alternative matrices can also be a source of microbial strains with enzymatic features, which can be useful for enriching food ingredients in bioactive compounds. Biotechnological processes of fermentation have been used for centuries to produce food often using selected starters, such as lactic acid bacteria (LAB) and yeasts with enhanced nutritional, organoleptic, technological, functional, and preservative molecules. However, the selection of a good candidate as starter strain needs of molecular characterization, evaluation of safety and potential pro-technological activities. In this work different cereal by-products (flours of wheat bran and wheat germ, defatted or not), vegetable by-product (fresh substandard peas) and finally flours obtained from Okra (Abelmoschus esculentus L.), a plant native to Africa, were collected. In order to isolate the beneficial microorganisms, these by-product matrices were plated onto MRS agar. A total of 20% of the colonies from countable plates were randomly taken, purified and stored at -80°C. The bacterial isolates were characterized by repetitive extragenic palindromic - PCR (REP-PCR) and isolates representative of each REP-PCR profile (21) were identified by sequencing of the 16S rRNA gene. Among strains isolated, only those belonging to the Qualified Presumption of Safety (QPS) list were characterized for antibiotic resistance, biogenic amine production, EPS production and proteolytic activity. Bacterial strains were deposited in the CNR-ISPA Culture Collection (ITEM Culture Collection) in cooperation with MIRRI-ERIC (an Infrastructure Research Project of the National Recovery and Resilience Plan (NRPP).