Isolation and identification of Autochthonous Lactic Bacteria for use in Cultures Starters in the Processing of Coastal Cheese

Abstract

In this study, native lactic bacteria present in raw milk used for the elaboration of coastal cheese were isolated and identified. Aseptic milk samples were taken from three (3) companies, stored at temperatures between 0-4°C. Make dilutions were performed with peptone water and plaque (MRS agar), species were purified by morphology, reaction to oxidase case, catalase and gram staining. The Identification of the isolated species was done using the API 50 CH system (BioMerieux). The results of the first two (2) companies showed the species Lactobacillus paracasei ssp paracasei 3, with a percentage of identification above 99.5%. Third company showed growth of yeast colonies without the presence of lactic bacteria. There was no growth of other bacteria during the investigation, possibly due to the use of inhibitory substances by producers, such as hydrogen peroxide, during the transfer of milk to processing centers. It is concluded that one of the autochthonous bacteria of raw milk that affect the final characteristics of the coastal cheese is Lactobacillus paracasei ssp paracasei 3 since it showed a considerable growth rate, despite possible inhibition conditions. This species can be used in starter's cultures and inoculated in pasteurized milk, to obtain typical organoleptic characteristics of cheese made from raw milk.