Authors : S. S. Khandare and S. D. Patil
Page Nos : 98-103
Description :
Abstract
This study aims to screen the inhibitory activity of lactic acid bacteria (LAB) isolated from idli batter against common food borne pathogens (FBP) and spoilage organisms (SO) associated with fish. S. aureus, E. coli, S. typhi, B. cereus, P. vulgaris and P. aeruginosa were isolated from ten fish samples and identified. Three LAB namely LAB-A, LAB-B and LAB-C exhibited the highest inhibitory activity, against all FBP and SO by agar well diffusion method, were selected and characterized morphologically and biochemically. The inhibitory activity of LAB was compared with indicator strain L. acidophilus MTCC 10307. 16S ribosomal RNA sequencing of isolates were done to identify the isolates. LAB-A was identified as Pediococcus acidilactici strain CSI29MX, LAB-B as Pediococcus parvulus strain MF233 while LAB-C as Pediococcus pentosaceus strain QN1D. All the three isolates exhibited the highest inhibitory activity, against Gram positive organism S. aureus and B. cereus with a Zone of Inhibition (ZOI) ranging from 14.9 mm to 15.9 mm and least for P. vulgaris with ZOI 12.8 mm to 13.6 mm. L. acidophilus MTCC 10307 showed lower activity against FBP and SO with ZOI of 11 + 0.1 mm and 11 + 0.2 mm against P. aeruginosa and E. coli respectively. The studies indicate that the LAB isolated from idli batter have highest potential of bacteriocin production than the indicator organism L. acidophilus MTCC 10307. Overall, the isolated LAB showed the remarkable inhibitory effect against both Gram positive and Gram negative FBP and SO. However, the spectrum of inhibition was different for the isolates tested. These results suggest that this potent isolates could be used as a natural biopreservatives in different food products.
