Aflatoxin B1 sensitive isolates of Lactobacillus casei and Lb. lactis

Iz sireva gauda, trapist, podravac i a la belpaese izdvajane su štapićaste bakterije mliječne kiseline. Identifikacijom 25 izolata utvrđeno je da 3 pripadaju vrsti Lactobacillus lactis, a 22 izolata vrsti Lactobacillus casei var. casei. Aflatoksin B1 djeluje inhibitorno na čvrstoj podlozi na sve ispitane sojeve, dok u lakmus mlijeku svi sojevi proizvode kiselinu i gruš, brže nego u kontrolnom mlijeku bez aflatoksina. Pored toga, svi sojevi Lb. casei i jedan soj Lb. lactis u lakmus mlijeku sa aflatoksinom izdvajaju sirutku i plin, a dva soja Lb. lactis ne izdvajaju. Prema tome, veliki broj izolata homofermentativnih bakterija mliječne kiseline u prisustvu aflatoksina B1 postaju heterofermentativni.The lactic acid bacteria were isolated from cheeses Gauda, Trapist, Podravce na a la Belpaese. There were determinated 25 isolates. Among them 22 belong to species of Lactobacillus casei var. and 3 to Lb. lactis. The aflatoxin B1 inhibition of growth all isolates of lactic acid bacteria on the agar medium. On the other hand, all strains formed more acid and faster milk curdling in the aflatoxin B1 presence, than in control milk. In the same time on the surface of the curd occured the milk serum and gas was detected, except in the case with two strains of Lb. lactis. The data suggests that isolated homofermentative lactic acid bacteria become heterofermentative due to the influence of aflatoxin