Isolation and characterization of metal and antibiotic resistant psychrotrophic bacteria from refrigerated spoiled food

• Main Authors: Asadi, Somayeh, Shahir, Shafinaz, Ibrahim, Zaharah, Yahya, Adibah, Md. Salleh, Madihah, Ibrahim, Norahim, Jamaluddin, Haryati, Abdul Wahab, Mohd. Firdaus, Abd. Manan, Fazilah, Hussin, Huszalina, Chong, Chun Shiong, Wan Dagang, Wan Rosmiza Zana
• Format: Article
• Language: English
• Published: Penerbit UTM 2014
• Subjects: QH Natural history
• Online Access: http://eprints.utm.my/id/eprint/53275/1/SomayehAsadi2014_Isolationandcharacterization.pdf; http://eprints.utm.my/id/eprint/53275/; http://dx.doi.org/10.11113/jt.v69.2656

The aim of this study was to isolate and characterize psychrotrophic bacteria resistant to antibiotic and metals from cold samples of refrigerated spoiled food and ice. Two isolates named H and F were successfully isolated from samples incubated at 10°C and 4°C, respectively. Both isolates were able to grow at 4°C, 10°C, 20°C and 30°C and exhibited multidrug resistance to antibiotics (chloramphenicol, ampicillin, tetracycline and kanamycin). Bacteria H and F were then further tested for their resistance to metal ions such as Cd2+, Zn2+, Cr 6+ and As 3+ at concentrations ranging from 0-10 mM. The results of the test revealed that the minimum inhibitory concentration (MIC) for isolate H was determined at 2 mM for all the metal ions. By comparison, isolate F was highly resistant to Cr6+, Cd2+ and Zn2+ with MIC of 10 mM for these cations, while MIC for As3+ was 4 mM. The results of comparing 16S rRNA gens demonstrated that isolate F has 98% identity match with Bacillus sp. This strain could be used as a model microbial strain to understand the mechanisms of metal resistance and as a source of psychrotrophic enzymes with potential application for bioremediation of heavy metals in cold environments