Laboratory contaminating bacteria of acidophilic extremophiles: Polymerase chain reaction (PCR) characterization

Some bacteria can survive in conditions in which even extremophiles cannot survive. In this study, the conditions of contamination of mine-waste extremophiles with other bacteria was studied on the laboratory scale. At the first step, the acid-producing extremophile bacteria were isolated from mine tailings and characterized using a biochemical protocol. The extremophiles survived at the pH from ۰ to ۸.۵ and temperature from ‒ ۷۰ °C to ۹۰ °C. After the complete growth and isolation of active colonies of the acidophilic bacteria in solid medium, their pollution possibility were examined in the laboratory. The characterization of contaminating microorganisms was performed through polymerase chain reaction (PCR) and ۱۶s rRNA gene sequencing. The polluting bacteria were isolated from the acid-producing bacteria using a nutrient broth liquid medium in a sterilized condition for ۱ week, which reached an anaerobic condition after a while. The significant growth of acidophilic bacteria in an anaerobic condition required the ۹K medium containing Fe۲(SO۴)۳ and elemental sulphur. The results showed that the contaminating bacteria of extremophiles included Bacillus cereus (strain ۱), Bacillus sp. (TS۳) and Bacillus oryzaecorticis (WJB۱۳۸), enduring the anaerobic conditions in a nutrient broth medium.

کلیدواژه ها:

Acid-producing extremophile bacteria ، Isolation ، Extremophiles’ contaminating bacteria ، Laboratory environment ، PCR