Vol. 7, Issue 11 (2018)

Author(s):
Neha Mary, Chirom Aarti, Ameer Khusro and Paul Agastian

Abstract:
Raw milk has a high nutritional content and it supports a rich microbiota. The objective of this investigation was to isolate and identify the novel bacterial strain from raw milk of buffalo and to optimize distinct parameters for ensuring the maximum production of antibacterial substances. The antibacterial substance producing bacterium was identified as Acinetobacter baumannii strain LAN1 based upon morphological and molecular characterization. Process optimization was carried out using one factor at a time method. Bifidobacterium broth medium was observed to provide better bactericidal activity against the indicator pathogenic bacteria, including Staphylococcus epidermidis MTTC 3615, Staphylococcus aureus MTCC 96, Shigella flexneri MTCC 1457 and Yersinia enterocolitica MTCC 840. The maximum antibacterial substances production from strain LAN1 was recorded at pH 6.0 (141.2 ± 1.76 to 168.5 ± 2.62 AU/mL) and 30 ⁰C (145.5±2.41 to 192.3±3.25 AU/mL). Likewise, lactose and ammonium chloride favored the maximum production of antibacterial substances from strain LAN1 with arbitrary units of 200.3±1.76 to 225.2±2.62 and 210.4±2.14 to 252.1±2.35 AU/mL, respectively. The isolate exhibited proteolytic activity and susceptibility towards conventional antibiotics too. In conclusion, A. baumannii strain LAN1, isolated from buffalo raw milk revealed antagonistic activity against human pathogens and suggested its further exploitation in varied industries based on its non-virulence characteristics.